EP2739556A1

EP2739556A1 - Control device for a hydraulic drive

Info

Publication number: EP2739556A1
Application number: EP11746468.5A
Authority: EP
Inventors: Roland Bisig; Esad IBRISIMBEGOVIC
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-08-04
Filing date: 2011-08-04
Publication date: 2014-06-11
Anticipated expiration: 2031-08-04
Also published as: US20140158469A1; US9457986B2; EP2739556B1; WO2013017141A1

Abstract

The invention relates to a control device (1) for a working fluid for operating a hydraulic drive (11) such as is used, in particular, for a lift. Said control device (1) comprises a flow path (6) for directing a volume flow of the working fluid in a first and a second direction, and a first and a second control valve (21, 22) for controlling the volume flow, a flow-measuring means (610) for measuring the volume flow, a pilot control means (3) with a first and a second pilot control valve (31, 32), and an electric actuating means (4) for interacting with a comparison means (52) for comparing the measured volume flow with a volume flow setpoint value which can be predefined by a setpoint value-setting means (51), and a regulator (53) for generating an actuating signal for activating the first and second pilot control valves (31, 32) via a coupling means (33) which can move to and fro between a first and a second position and has the purpose of controlling the volume flow of the working fluid through the first and second control valves (21, 22), wherein in the first position of the coupling means (33) each pilot control valve (31, 32) can be actuated, and in the second position of the coupling means (33) only the first pilot control valve (31) can be actuated, by the electric actuating means (4). Furthermore, the invention relates to a hydraulic drive system (16) for a lift having the control device (1) and a method for retrofitting such a drive system. The invention is distinguished from conventional control devices by both simplifications in the design and operation and corresponding cost advantages as well, in particular, by a relatively low degree of expenditure on maintenance accompanied at the same time by increased protection against failure. Said invention permits, in a hydraulic drive system, the automatic compensation of drive-side and output-side interference variables as well as load-induced fluctuations in the working fluid pressure in favour of a continuous output movement and load-independent starting without a delay, and consequently overall an improvement in the starting quality in a lift.

Description

Control device for a hydraulic drive

description

Field of the invention

The invention relates to a control device for a hydraulic drive or for a working fluid of a hydraulic drive, as used in particular in hydraulic drive systems for lifts, and allows the control of the working fluid in the direction and volume corresponding to a predetermined volume flow setpoint. Furthermore, the invention relates to a hydraulic drive system for an elevator and a method for retrofitting such a drive with the control device according to the invention.

Background of the invention

In hydraulic drives, the drive energy is known to the pressure and the flow rate of a circulating, controlled by a reservoir, which is usually designed as an oil pan, via a motor-driven pump pressure side to a hydraulic load and from this low-pressure side back into the reservoir, guided working fluids , To guide the working fluid in this circuit are between the said drive components each provided hydraulic power lines in fluid communication. The pump is typically a constant or variable displacement hydraulic pump, such as a screw pump or a radial piston pump driven by an electric motor. As a consumer, hydraulic motors are used to generate a translatory or rotary output motion; The former can as a hydraulic cylinder, the latter be designed as gear motors. The working fluids used are usually fluids based on mineral oils, so-called hydraulic oils, synthetic fluids or vegetable-based fluids, the latter being particularly distinguished by their environmental compatibility. These working fluids may contain additives which allow a specific influencing of individual properties, such as the temperature behavior, the aging resistance or the corrosion effect.

Hydraulic drives are characterized by their high power density, their high efficiency and their simple, stepless controllability of the output movement with high positioning accuracy and are used both in vehicles and in stationary systems. The hydraulic power lines provided for guiding the working fluid both between the pressure side of the hydraulic pump and the pressure side of the hydraulic motor and between its return side and the reservoir are designed in a flexible and / or rigid design, so that the volume flow of the working fluid also over larger Distances can be transferred without significant additional mechanical effort and there is the possibility of a separate arrangement of the drive and driven side of the hydraulic drive and the motor-driven pump and the hydraulic consumer. As a result, hydraulic drives can largely be adapted to almost any spatial conditions with little space consumption. This turns out particularly in the case of using such a drive in a hydrauli ^¬'s drive system for an elevator in so far advantageous as the drive assembly is not necessarily in the elevator shaft, together with the hydraulically metallic consumer or hydraulic jacks, but optionally also removed may be disposed of which , In this respect, the hydraulic drive can also be described as a hydrostatic transmission which, in a closed or open circuit, converts a hydraulic pump, a hydraulic motor and a reservoir with the working fluid and the flow connections provided between these components for guiding the working fluid. summarizes. As flow connections, or line connections for conducting the working fluid, within such a hydraulic system basically all known suitable flow connections are inferge ge, ie both rigid conduit elements, such as pipes or recesses in a housing of a single system component, as well as flexible line elements, like hoses.

A hydraulic drive system, in addition to the hydraulic drive, any other devices for trouble-free operation, such as filtering and / or discharge of the working fluid and safety devices, such as pressure relief valves, a control device for continuous or discontinuous control of the flow rate of the working of the hydraulic pump to the hydraulic motor and from this back into the reservoir. In this case, the control device is connected to the hydraulic power lines of the drive system by means of hydraulic control lines such that the working fluid can be controlled in the direction and volume to and from the hydraulic load or hydraulic motor without reversing the direction of pump flow by the control device, in such a way that the volume flow the working fluid to the hydraulic consumer towards a steady output movement in a first direction and away from the hydraulic consumer allows a corresponding output movement in a second direction. Like the hydraulic power lines and the hydraulic control lines are designed in a conventional manner in a flexible and / or rigid design and differ so far from the former essentially only by their lower cross-section.

In the case of approximately constant output loads, the compressibility of the working fluid in hydraulic drive systems is negligible. However, if loads that change greatly on the hydraulic load occur, as is the case with a hydraulic drive system for an elevator, for example, due to the elasticity of the volume of the drive fluid, pressure and movement Variations occur, whereby the desired continuity of the output movement, or the output speed and force, is no longer reliable given. As a result of severe operational heating of the working fluid, viscosity changes in the working fluid can also occur, which have a similarly disadvantageous effect on the operating behavior of the hydraulic drive system. In particular, the desired continuity of the output movement of the hydraulic load can also be affected by pump-related volume flow fluctuations of the working fluid.

A control device for controlling the speed of a hydraulic motor of the type mentioned, which has the features of the preamble of claim 1, describes CH-A5-629 877. Thereafter, the speed of the engine via the flow of oil in the engine inlet with a suitable flow meter can be detected and in a convertible electrical signal which can be fed to a comparator, which forms a control signal for a respectively arranged in the inflow and outflow of the engine control valve in response to a predetermined setpoint signal. For valve actuation in each case an electromagnetic transducer in the form of a solenoid valve is provided in electrical connection with the comparator. The components mentioned so far represent a control loop that is suitable to compensate for deviations from the setpoint effectively. The known control device thus enables a specification of defined motor speeds and an effective compensation of disturbing influences, such as pump pressure and load fluctuations.

Although it is possible with such a control device to overcome the aforementioned disadvantages of a hydraulic drive system. Nevertheless, this also has disadvantages. So it is particularly disadvantageous that for the actuation of the two control valves each have their own electrical actuator in the form of one each with a pilot valve coupled electromagnetic converter is required to the desired direction-dependent control of the flow rate of the working fluid in the pressure and never - the pressure-side connecting line of the hydraulic consumer, and thus to ensure the correcting of disturbing influences. However, the use of two electric actuators is reflected not only in the manufacturing and operating costs of such a control device, but also requires an increased risk of failure, which in turn reduces the reliability of the entire hydraulic drive system.

Summary of the invention

It is therefore an object of the invention to provide a control device for a hydraulic drive, which overcomes the disadvantages of the prior art, which is thus suitable in a hydraulic drive system at different adjustable drive speeds, the effect of strongly changing output loads, temperature-induced viscosity changes and / or density variations as well as pump-related volumetric flow fluctuations of the working fluid to the desired continuity of the output movement, or the output speed and force, of the hydraulic load effectively and moreover has a simpler construction and function in particular, which is less expensive to produce and operable and in a hydraulic drive system is suitable to improve its reliability by reducing the risk of failure. Furthermore, it is part of the object of the invention to provide a hydraulic drive system for an elevator with the control device according to the invention. Finally, it is part of the object of the invention to specify a method for retrofitting a hydraulic drive system for an elevator with such a control device.

This object is achieved in that in a control device for a working fluid for operating a hydraulic drive according to the preamble of claim 1, a flow path for conducting a volumetric flow of the working fluid in a first and in a second direction, a first and second tes control valve for controlling the volume flow in the flow path, a flow measuring means for detecting the volume flow in the flow path, a comparison means for comparing the detected volume flow with a predetermined volume flow setpoint and a pilot control means for actuating the first and second pilot valve are provided, wherein the flow path, the flow measuring means, the comparison means, the pilot control means and the first and second control valve form a control circuit for maintaining the flow rate of the working fluid in the flow path in dependence on the volumetric flow setpoint and the pilot control means comprises a first and second pilot valve for controlling the first and second control valves and the control device is characterized in that the pre-control means comprises an electrical actuating means for actuating the first and second pilot valves and a coupling means for coupling the first and second pre wherein the coupling means is formed with a coupling region for reciprocating between a first and a second position, wherein in the first position, the first and second pilot valves coupled through the coupling region and in common by the electrical adjusting means for allowing the volume flow of the working fluid are operable in the second-direction flow path in the second direction, while in the second position of the coupling portion of the coupling means, the first and second pilot valves are decoupled and only the first pilot valve is decoupled by the electrical adjusting means for allowing the volume flow of the working fluid in the flow path in the first direction by means of the first control valve is actuated. The inventive design of the control device with two pilot valves and a coupling means with a coupling region which couples in its first position, the two pilot valves to allow common operation by an electric actuator and in this way the flow path for the working fluid through the second control valve the second direction - preferably from a hydraulic consumer a reservoir in a hydraulic drive system - while in the second position of the coupling portion of the coupling means, the two valves are decoupled from each other and the electric actuator can actuate only the first pilot valve, so that the flow path for the working fluid through the first control valve in the first direction - Preferably, from the reservoir to the hydraulic load in the hydraulic drive system - is released, construction and function of the control device over the prior art are significantly simplified. The constructive simplification results directly from the fact that for the directional control and speed control of the volume flow of the working fluid only a single electrical actuating means, in addition to a simple and cost-effective coupling means, is required, which in turn is accompanied by a functional or control-technical simplification, and indeed insofar, only has to be switched back and forth between a coupling position and a decoupling position of the coupling region of the coupling means to actuate both pilot valves.

The constructional and functional simplification, however, also has an ^{unequivocally} advantageous effect on the costs for the control device and on its ^failure safety. The coupling means, which is provided according to the invention instead of a second electrical actuating means, can be made comparatively very inexpensive from only a few, simple and robust mechanical parts and thereby allows and by its function limitation to only two defined switching positions maintenance-free operation over the entire life of the control device. Consequently, the control device according to the invention can not only be produced and operated more cost-effectively, but also has a higher overall reliability. In a hydraulic drive system with the control device according to the invention, the advantages mentioned contribute in particular to a reduction of the operating and maintenance costs as well as to an increase of the system reliability. In that regard, it is advantageous even in use retrofitting existing hydraulic drive systems with the control device according to the invention, it is thereby possible to meet even more stringent safety requirements, as they apply just for elevator systems. The requirements for compliance with the differently adjustable output speeds or speed specifications for the output movement of the hydraulic load, with changes in the output load, temperature-induced changes in viscosity, density and / or the volume flow of the working fluid generated by the pump - in other words, the Requirements for the continuity of the output movement or the output speed and force of the hydraulic consumer - meets the control device according to the invention primarily by a continuous actual setpoint comparison of the volume flow of the working fluid in the pressure-side inlet or outlet of the hydraulic consumer in the principle of CH-A5- 629 877 known manner, however, to compensate for these disturbances only a single electrical actuating means and a simple coupling means, instead of the disclosed there two electrical actuating means are needed. In this respect, the invention represents an advantageous further development of this known control device. In particular, for applications with only minor requirements for the constancy and positioning accuracy of the output movement, the control device can in principle also without a control loop, ie without the flow measuring means for detecting the volume flow actual value and the formation the difference signal from the actual and setpoint of the volume flow of the working fluid as a control variable of the control loop, be provided. In such an otherwise unchanged control device, the electrical actuating means, and thus each or only the first pilot valve, is controlled directly proportional to the desired value. This control can be done, for example, according to a defined time pattern and additionally corrected with pressure and / or temperature information. The solution component of the object of the invention is also a hydraulic drive system for an elevator according to claim 17, comprising a reservoir with a working fluid, a motor-driven pump, a hydraulic consumer, a control device and conduit means in a manner between the reservoir, the control device and the Hydraulic consumers are provided that the working fluid from the reservoir via the pump and the control device to the hydraulic consumer and from this back via the control device to the reservoir is feasible, wherein the hydraulic drive system is characterized in that the control device according to the in claims 1 15 to 15, and in particular a single electric actuating means and a coupling means with a reciprocating coupling area for actuating the pilot valves for controlling the volume flow in the flow path to and from the hydraulic consumer.

A further solution component of the object of the invention is finally a method for retrofitting a hydraulic drive system for an elevator, which, according to the preamble of claim 17, a reservoir with a working fluid, a motor-driven pump, a hydraulic see consumers, a control device and conduit means, which is provided in a manner between the reservoir, the control device and the hydraulic consumer, that the working fluid from the reservoir via the pump and the control device to the hydraulic consumer and from this back via the control device to the reservoir is feasible, wherein the control device corresponding The preamble of claim 1, a flow path for directing a volume flow of the working fluid in a first and in a second direction, a first and second control valve for controlling the volume flow in the flow path, a flow ssmessmittel for detecting the volume flow in the flow path, a comparison means for comparing the detected volume flow with a predetermined volume flow setpoint and a pilot control means for actuating the first and second control valve, wherein the flow path, the flow measuring means, the comparison means, the pilot control means and the first and second control valve, a control circuit for maintaining the volume flow of the working fluid in the flow path in dependence form the volumetric flow setpoint and the pilot control means comprises a first and second pilot valve for controlling the first and second control valves and further comprising a first electrical actuating means for actuating the first and a second electrical actuating means for actuating the second pilot valve.

The retrofitting method according to the invention is characterized by a method step in which in the abovementioned hydraulic drive system for an elevator, a coupling means for coupling the first and second pilot valve is replaced, which replaces the second electrical actuating means for actuating the second pilot valve, wherein the coupling means a coupling region for reciprocating between a first and a second position is formed, wherein in the first position, each pilot valve coupled through the coupling region and actuated by the first electrical actuating means, so that the second control valve, the flow rate of the working fluid in the flow path in the second direction, so as preferred by a hydraulic drive to a reservoir, allows. On the other hand, if the coupling area of the coupling means assumes its second position, then the second pilot valve is decoupled from the first pilot valve, so that only the first pilot valve can be actuated by the first electrical actuating means to control, by means of the first control valve, the volume flow of the working fluid in the flow path in the first flow control valve Direction, so as preferred from the reservoir to the hydraulic drive, release. The advantages associated with both the hydraulic can achieve drive system for an elevator as well as with the retrofitting method according to the invention for such a drive system, resulting directly from the above-mentioned advantageous effects for the control device according to the invention. Advantageous embodiments of the invention will become apparent from the dependent claims and will be explained in more detail below.

The coupling means, the first and second pilot valve and the electrical actuating means are arranged as components of the pilot control means or the pilot control in the control device, wherein the coupling means comprises the movably mounted coupling region. In its constructive shape, the coupling means, which can also be referred to as a coupling body, essentially determined by the respective direction of action of the movements to be coupled and must insofar, in addition to a sufficient mechanical stability over the intended service life, essentially a defined temporary interaction on the of him covered coupling area with the two to be coupled pilot valves allow. This coupling region may be comprised of different coupling means of different materials and with different surface properties. In any case, the coupling region is arranged to be movable with respect to the two pilot valves, that an actuating movement of the first pilot valve from the closed position to the open position - or vice versa - is transferable through the coupling region to the second pilot valve, so that the latter in its adjusting movement between closing - And open position can be synchronized with a corresponding actuation of the first pilot valve. The electrical actuating means is designed for direct interaction with the first pilot valve.

In order to move the coupling region of the coupling means from its first position to its second position, in which the two pilot valves are no longer coupled and thus the electrical actuating means only the actuate the first pilot valve, an impulse is required, which is applied by a force generating means. As such, in principle, all adjusting means come into question, which are able to provide the mechanical energy required for the position change as kinetic energy, such as a spring or an electromagnetic transducer. In any event, regardless of the type of force generating means ultimately used, there is provided a force impulse guiding means for the defined alignment of the impulse of force generated by the impulse generating means with the coupling means. This force impulse guiding means has a first and a second end and is designed so that an impulse generated by the impulse generating means can be guided largely loss-free from the first via the second end to the coupling means. In this respect, a suitable such force-transmitting guide means, for example, a formed in the form of a tube hydraulic conduit means with its inlet and outlet, which supplies a fluid as Kraftstoßerzeugungsmittel and thus transported a pressure impulse as force impulse the coupling means such that the pressure increase in the fluid at the outlet of the tube, or at the second end of the Kraftstoßführungsmittels, allows a desired displacement of the coupling means portion of the coupling means. Generally, the power surge guiding means is always adapted to the force generating means such that a force surge generated by the force generating means permits reliable release of the coupling portion of the coupling means from each pilot valve and ensures a defined movement of the coupling portion of the coupling means from its first position to its second position. In addition to a direct impulse transmission in which the impulse generating means, guided by the force impulse guiding means, acts directly on the coupling means, indirect or indirect impulse transmission between the impulse generating means and the coupling region of the coupling means from the first to the second end of the force-imparting means may occasionally also be advantageous be. As impulse transmission means preferably used movably guided rigid body or plunger, but without excluding other transfer agents, such as fluids, in principle. The power surge guiding means is suitably adapted to the respective force transfer means, so that in this embodiment of the invention, a reliable release of the coupling region of the coupling means of each pilot valve and its defined movement from the first to the second position are possible. As tappet material, any material suitable for hydraulic applications, which has the necessary mechanical rigidity, can be used. Preferably, the plunger is made of metal, such as steel.

This variant is particularly advantageous if recourse is made to commercially available components in the realization of the setting function. In a structural unit, such transmission means usually comprise, in addition to a standardized connection for the force-generating means, a plunger whose reciprocating motion is usually longitudinally movable and whose ends are respectively designed for force input and output, a guide means having a first and a second end for sliding engagement with the plunger between the two ends in its reciprocal motion and return means for biasing the plunger in its rest position. The guide means is generally formed as a cup-shaped guide sleeve, in which the plunger is slidably mounted against a helical compression spring.

In view of the purpose of the control device according to the invention, namely the control of a working fluid for operating a hydraulic drive, it is particularly preferred to use the working fluid for the hydraulic drive as force generating means, which, by a suitable design of the holding forces of the coupling means and the holding means of the first Control valve, when switching on the pump first moves the coupling means from its first to its second position, before the holding force of the holding means the first control valve overcomes and its piston or shut-off from the closed position in which the valve inlet is closed by the piston, in the open position in which the valve inlet opening is opened moves. For this purpose, the abovementioned impulse transmission means is designed as a hydromechanical transmission means with a working fluid connection and a hydraulically indirectly acting plunger and is connected via a hydraulic control line to the flow path of the working fluid such that it is actuated when a defined working fluid pressure is reached in the flow path to reliably release the coupling portion of the coupling means from each pilot valve and to allow its defined movement from the first to the second position. In this case, the working fluid connection is provided at the first end of a force-conveying guiding means designed in the form of the cup-shaped guide sleeve. In other words, the force impulse required for the actuation of the coupling means is generated by the volumetric flow of the working fluid intended for operation of the hydraulic drive. Depending on the control concept selected in each case, this can be done, for example, by switching the motor-operated pump on and off or by opening and closing an additional shut-off device in the flow connection between the pump and the coupling means. However, it is preferable to provide a bypass valve controllable via a valve control connection or via a valve control opening in the control device according to the invention which, in its open position, returns the working fluid conveyed by the pump into the reservoir and in its closed position increases the pressure of the working fluid or Force impulse in the flow path allows, which in turn can move the coupling agent from its first to its second position. The hybrid-mechanical transmission means is set in such a way that the coupling region of the coupling means is displaceable from the first to the second position almost without delay by the plunger. It is particularly advantageous according to the invention on the direct connection of Pump and coupling means based control concept can be used in a drive system for a hydraulic elevator system, as this no additional control effort is required. The hydraulic motor, which is designed in this case as a single or multi-stage, directly or indirectly to a movable platform, in particular a cabin or a car for Personenbeförde- tion coupled lifter or hydraulic cylinder is in a hydraulic elevator only during the stroke of the pump driven, while the lowering by discharging the working fluid from the hydraulic motor, and thus solely by the existing weight forces occurs. In order to control the volume flow of the working fluid in the flow path to and from the hydraulic motor, it is therefore sufficient in the case of a hydraulic elevator if the control device or the coupling means encompassed by it comprises a suitable flow connection to the pump. Thus, the control device according to the invention is characterized not only by simple mechanical components with regard to the pilot control, but in particular also by a significantly reduced control effort compared with the prior art. Although it is preferred in the control device according to the invention to use the working fluid itself as an impulse generating means, control concepts are conceivable in which other, functionally equivalent, impulse generating means may be of particular advantage for impulse generation, such as electromagnetic actuators in conjunction with corresponding electrical actuation means ,

The coupling region of the coupling means according to the invention preferably as a convex surface, in particular in the form of the surface of a spherical coupling means or coupling body, provided to minimize friction losses in contact with the pilot valves and optionally a Kraftstoß- transfer agent or plunger in an actuating movement as far as possible. In this respect, a steel ball whose surface comprises the coupling region is preferably used as the coupling agent; Steel balls are commercially available in various, closely tolerated dimensions and surfaces. They are also resistant to heavy mechanical loads, are maintenance-free and, moreover, cost-effective and therefore also perfectly fulfill all the essential requirements for the coupling area. In some cases, however, it may be preferable to form the coupling region with another topography and / or from a different material or from a combination of different materials. For example, the coupling region may be provided in the form of a metallic coating, optionally of different metals, on a plastic base body as a coupling means. In order to allow a change in direction of an actuating movement to be transmitted through the coupling region, the coupling region can be provided, for example, as a side surface of a prismatic coupling body.

Finally, it may be desirable to support the return of the docking area from the second to the first position. For this purpose, a suitable restoring means, preferably a spring, arranged in the pilot control means, that the holding force of the return means, or clamping force of the spring counteracts the impulse of the impulse generating means, so that a secure return dividing the coupling portion of the coupling means in the first position a decrease in the force is ensured by the impulse generating means; the return means are so far ahead of the rest ^¬ position or starting position of the coupling region of the coupling agent. In combination with the abovementioned hydromechanical impulse transmission means and a suitable dimensioning of the two restoring means or springs, this results in the advantage of play-free interaction between plunger and coupling means.

With the control device according to the invention, it is thus possible in an equally advantageous and surprising manner, to ensure the functionality of the known control device by only a single electric actuator or actuator, while reducing the risk of failure. As an electrical actuating means for the actuation of the first and second pilot valve, an electromagnetic actuator is preferably provided. Alternatively, a stepper motor or a piezoelectric actuator may be preferred for this purpose, but without excluding other functionally equivalent actuating means in principle. In the sense of the invention, the feature of electrical adjusting means encompasses all electromechanical actuators which can convert electrical energy into the mechanical energy required to actuate a hydraulic valve.

The two in the control device according to the invention with the Vorsteuermit- to control the flow rate of the working fluid in the flow path in the first and second direction, and / or to the hydraulic consumer, cooperating control valves can be used in principle in any commercial and for the intended use in a Elevator control be designed suitable design; such valves generally have a one-piece or multi-part piston, which is mounted in a guide means, which is formed for example as a recess in a metallic valve block or as a separate sleeve or cup-shaped housing each with the required valve openings, movable between an open and closed position is. However, it is particularly advantageous to form the two control valves and their flow connection within the control device in the following preferred manner according to claims 7 to 15 in order to achieve a further improvement of the control device specified in the claims 1 to 6 over the known control device. In this way not only significant further cost savings are possible. Rather, this also associated with functional improvements that directly contribute to a further increased reliability of the control device and - in the case of a hydraulic drive system - to further reduce the operating and maintenance costs and to further increase the system reliability. These advantages arise directly from the following explanations of the other preferred embodiments of the invention.

In a known manner, the first and second control valves for controlling the volumetric flow of the working fluid in the flow path each include a valve inlet port, a valve outlet port and a valve control port in flow communication with the flow path, a shut-off piston between an open and closed position of the valve. and is movable, so that a stepless transition between the two positions is made possible, a guide means or a sleeve for displaceably guiding the shut-off and a holding means or clamping means, preferably a compression spring which the shut-off in the open position or alternatively in the closed position of Prevents control valve, or on this a holding force in the respective direction exerts, and holds him in this respect in the respective position. The valve structure according to the invention differs from the structure of known valves in that the guide means and the shut-off body each have a plurality of corresponding or geometrically matched areas for sliding interaction in the reciprocating movement of the shut-off. Preferably, the guide means comprises a total of three guide means of different structural design in sequential order and in each firm connection, namely a first NEN guide means with a first guide means region, a second guide means part with a second guide means region and a third guide means part with a third guide means region. Each of these guide means regions is in a corresponding manner with the shut-off body designed so that it is relative to the guide means between the open and closed positions of the control valve along its longitudinal extent, or along the valve longitudinal axis, reciprocally movable and in each case slidably at least with the cooperates first and second guide means area. In the closed position of the respective control valve, the shut-off body also acts sealingly together with the third guide means area. For this purpose, the guide means preferably comprises in its first and third guide means part in each case a bearing bush for axially displaceable mounting of the shut-off body; The first guide means area is so far formed by the shut-off wall facing the provided as a first guide middle part socket, the third guide means region of the corresponding wall of the third guide middle part provided socket and enclosing the shut-off in each case in its respective corresponding area. The second guide means part comprises a plurality of pins, preferably three cylindrical pins extending between the first and third guide means in parallel alignment with the longitudinal axis of the valve and spaced from each other, preferably equidistant, around the shut-off body so as to be slidably engaged with it Can cause reciprocation between the open and closed positions of the valve. Each pin is in each case firmly connected with its first end to the first guide middle part and with its second end to the third guide middle part in such a way that the second guide means region comprises a part of the lateral surface of at least one of the pins. If the pins are preferably cylindrical pins and, in the case of the shut-off body, preferably a rotating part, the second guide means region is thus by a suitable spacing of the pins from the shut-off body to the contact line between the at least one pin and to restrict the shut-off; If there is a line contact under the action of force, the resulting pressure surface is known to be rectangular. However, it is preferred that all pins can interact in a sliding manner with the shut-off body, so that the second guide-means area comprises the contact lines of all the pins with the shut-off body. The first and third guide middle part thus form together with the total of the pins comprehensive second guide means part a functional unit, thus the guide means. In the embodiment of the first and second control valve according to the invention, the valve control opening is in each case encompassed by the first guide part, while the valve outlet opening of the first control valve and the valve inlet opening of the second control valve are associated with the second guide means part and the valve inlet opening of the first control valve and the valve outlet opening of the second control valve are associated with the third guide means part. Due to the realization of the second guide means part with pins and thus without additional manufacturing cost associated significant reduction in the contact area between the guide and shut-off, occurring during valve actuation adhesive and sliding friction can be reduced significantly and targeted in a very cost effective manner. This reduction of the friction losses directly causes an improved switching reliability and an extension of the life of the inventively constructed control valve and results in a hydraulic drive system to a reduction in maintenance costs and a stabilization of the output movement. Alone by the preferred use of commercial pens, which are available in a large selection in almost all candidate materials for this use, surface finishes, dimensions and tolerances cost as semi-finished, and the consequent significant material savings in the production of the guide means over conventional guide bushes are In addition, the production costs of the inventive control valve significantly lower than those of a conventional valve. The use of such pins also has the advantageous effect that the required dimensional tolerances in the guide means substantially by an exact assignment of the first and third guide middle part can be maintained, thus easily by an exact positioning of the holes for receiving the pins in the respective area ensure. In particular, with regard to a simple and economical installation of the control valve according to the invention, the guide means for interacting with the shut-off and the holding means is designed in such a way that its inner diameter or its effective opening width, from the first via the second to the third guide means part steadily decreases, so the opening width of the guide means in the first guide middle part is greater than in Opening width of the guide means in the first guide middle part is greater than in the second guide middle part and in the second guide middle part is greater than in the third guide middle part. Alternatively, the opening width can also increase in a corresponding manner from the first via the second to the third guide middle part. The valve function is thus ensured, as well as the shut-off body is formed with corresponding corresponding Absperrkörperbereichen, that includes a first, second and third Absperrkörperbereich whose respective effective outer diameter is adapted to the corresponding opening width of the first, second and third guide means part. The valve assembly, or the insertion of the shut-off and holding means in the guide means, is thus possible in each case from the guide middle part with the largest opening width. The relative mobility of the shut-off body between the open and closed positions of the respective control valve with respect to the respective guide means is limited in this way by the third and first guide means part.

It is advantageous and particularly preferred to form the third guide middle part in its region adjoining the second guide middle part with a plurality of recesses. These recesses are oriented relative to the valve longitudinal axis and can taper in the closing direction of the respective control valve. For example, these recesses are U-shaped, V-shaped and / or Y-shaped. Additionally or alternatively, it is preferable to form the third guide middle part in its region adjacent to the second guide middle part with a chamfer, so that the third guide means region tapers in a funnel shape in the closing direction of the respective control valve. By means of these recesses and / or the chamfer within the third guide middle part in its region adjacent to the second guide middle part, a constant change of the effective area of the valve opening, or the valve inlet opening of the first control valve and the valve outlet opening of the second control valve, during the movement of the locking body within the third guide means part allows. For the inventive control device this has a largely constant flow conditions in the operation of the first and second control valve result. In a hydraulic drive system, the control device according to the invention with the two preferred control valves can thus provide a substantial contribution to the stabilization of the output movement. In addition, this preferred embodiment of the third guide means part of the first and second control valve causes a reduction of flow noise during operation of the control device, which thus also has the further advantage of lower noise. With regard to a simpler and more cost-effective production and maintenance of the control valve according to the invention, it is further preferred to provide the sealing region of the respective control valve in its closed position, more precisely the third guide means in its side facing away from the second guide middle part, as first separately prepared annular, preferably self-positioning, sealing insert and this in the course of valve assembly with the third guide means part, preferably by means of an O-ring to connect, so that the annular sealing insert and the third guide means part form a structural unit. The annular sealing insert is designed to cooperate with the corresponding third Absperrkörperbe- range of the shut-off to such that it touches the third Absperrkörperbereich only in the closed position of the control valve along a valve opening enclosing, preferably circular, contact line sealingly; Specifically, the third guide means region does not serve as the first and second guide means of the guide means to guide the shut-off body when moving back and forth between the closed and open positions of the control valve, but to a reliable closing by means of the annular sealing insert encompassed by it to ensure the control valve in cooperation with the third Absperrkörperbereich the shut-off. In a preferred embodiment of the control device according to the invention the shut-off of the second control valve is integrally formed with the first, second and third Absperrkörperbereich and arranged displaceably in the guide means with the respective first, second and third guide means. The holding means, which is preferably in the form of a spring, in particular a cylindrical compression spring, is arranged such that its holding or spring force acts on the third Absperrkörperbereich in the direction of the third guide means region of the third guide means part, so that the second control valve through the Holding means is biased in the closed position of its valve outlet. For a defined introduction of the spring force into the shut-off body, the first shut-off body region preferably has a blind bore, so that the spring is guided along the valve longitudinal axis. Alternatively, however, the holding means can also act directly on the front side on the first Absperrkörperbereich, in which case a defined assignment between the two components is preferably ensured by suitable projections on the Absperrmittelstirnseite. The valve is provided in this embodiment in the control device according to the invention for controlling the volume flow of the working fluid in the second direction in the flow path. In the hydraulic drive system according to the invention, this controls, as a second control valve, the volume flow of the working fluid in the outlet of the hydraulic consumer.

In a further preferred embodiment of the control device according to the invention, the shut-off body of the second control valve has a stem-shaped projection on its end assigned to the third guide middle part. This stem-shaped projection is designed so that it can act for an emerging from the second control valve volume flow of the working fluid in the manner of a baffle plate, so from the third valve opening - this represents the valve outlet in the second control valve - attenuating outlet flow of the working fluid. Due to the fixed connection of the stem pelförmigen projection with the shut-off the released during the damping kinetic energy of the working fluid acts as a restoring force on the shut-off, which is thus moved by the flow of the working fluid in its closed position; the restoring force generated in the damping acts in the same direction as the holding force of the holding means, through which the shut-off of the second control valve in its closed position is preserved. This embodiment of the control device according to the invention has the advantage of even more stable controllability of the volume flow of the working fluid. Although in the control device according to the invention, preferably only the second control valve is formed with the stempeiförmigen projection, it may be equally advantageous in individual cases to provide the shut-off of the first control valve in this form; In principle, the stem-shaped projection can be provided both on a one-piece and on a multi-part shut-off. According to a further preferred embodiment of the control device according to the invention the shut-off of the first control valve is in several parts, in particular in two parts, in the form of a first and second Absperrkörperteils. In this case, the first shut-off body part comprises the first and an additional fourth shut-off body region and the second shut-off body part comprises the second and third as well as an additional fifth shut-off body region. The fourth and the fifth Absperrkörperbereich are slidably mounted interlocking in a manner that the length of the shut-off body is variable. In other words, the first and second shut-off body part of the first control valve are mounted displaceable relative to one another, so that the total length of the shut-off body can be changed by telescoping the fourth into the fifth shut-off body area or vice versa. This allows the holding means, preferably in the form of a spring, in particular a cylindrical compression spring, cooperate with the shut-off in such a way that the holding force of the holding means or its spring force on the one hand to the second part of the shut-off on the third Absperrkörperbereich and on the other hand acts on the first part of the shut-off body via the first Absperrkörperbereich so that a reduction in the length of the shut-off by a movement of the first Absperrkörperteils or the second Absperrkörperteils on the other Absperrkörperteil or Absperrkörperteile each other and both Absperrkör- perteile relative to the guide means, at a constant length of the shut-off, against the holding force of the holding means are movable. If the first shut-off body part in the closed position of the control valve, in which the second shut-off body part with its third Absperrkörperbereich sealingly touches the third guide means portion of the third guide means part, applied with a force in the direction of the second Absperrkörperteils against the holding force of the holding means, thus resulting in a proportional force Reduction of the length of the shut-off body. The maximum adjustability and thus the minimum length of the shut-off is reached when both Absperrkörperteile abut each other; If the degree of overlapping of the fourth shut-off body region of the first shut-off body part and the fifth shut-off body region of the second shut-off body part in the rest position of the holding means is 50%, this results in the maximum adjustability being half the penetration depth of the fourth into the fifth shut-off body region or vice versa.

Such a bypass valve is provided in the control device according to the invention as a first control valve for controlling the volume flow of the working fluid in the flow path in the first direction. In the control device according to the invention, this first control valve enables the control of the volumetric flow of the working fluid in the inlet of the hydraulic consumer. It has the additional significant advantage that it allows an automatic operating point setting under changing operating conditions such as load and / or temperature fluctuations within a hydraulic drive system, whereby a corresponding adjustment of the circulation or pilot pressure of the working fluid in the hydraulic system is unnecessary. Another particularly advantageous embodiment of the control device according to the invention with the bypass valve has in particular in a hydraulic drive system for an elevator in addition to the advantages mentioned above also the advantage that switching or releasing the volume flow of the working fluid in the flow path in the first direction of a nem Reservoir via a motor-driven pump to a hydraulic drive and almost delay-free and substantially independent of the respective payload of the elevator, so with minimal and load-independent dead time can be done. Thus, the control device allows in the embodiment given below compared to the prior art, in addition to the load-independent smooth start of the pullout cab, also a load-independent starting without significant time delay, thus further improving the approach quality of the elevator. This further embodiment of the invention thus additionally solves the sub-task of minimizing the unwanted time delay during closing of the bypass valve, regardless of the load-induced working fluid pressure prevailing in the flow path.

This sub-object is achieved in that in the control device according to the invention the first control valve in the above-mentioned embodiment is connected to a two-part shut-off body with the flow path such that the flow connection between the valve inlet opening and the flow path for directing the volume flow of the working fluid in the first Direction, between the Ventilauslassöffnung and the flow path for directing the flow of the working fluid in the second direction and between the valve control port and the flow path for directing the volume flow of the working fluid in the first and in the second direction. Specifically, the flow communication between the valve control port of the first control valve and the flow path in parallel arrangement includes a throttle element for damping the flow rate of the working fluid from the valve control port, a check valve for conducting the working fluid to the valve control opening and a hydromechanical transmission means for mechanically moving the shut-off on the valve control port. The valve control opening of the first control valve is also connected via the throttle element to the pilot control means, so that an increase in pressure in the working fluid at the valve control port enabled by the pilot control means in the second position of its coupling means via movement of the check valve of the first control valve from its open - In its closed position causes a flow of the working fluid in the flow path in the first direction. By this configuration of the flow connections of the first control valve within the control device according to the invention, it is thus possible that the piston of the first control valve always moves from its open position to its closed position when the coupling means of the pilot control means assumes its second position; in the second position, the two pilot valves are decoupled by the coupling means, so that the first pilot valve by its associated electrical actuating means from its open position to its closed position is movable, while the second pilot valve remains in its closed position by the holding force of its associated mechanical actuating means , Consequently, in the second position of the coupling means of the pilot control means, the working fluid from the valve control port of the second control valve can not flow off via the pilot means, causing a relative increase in pressure at the valve control port of the first control valve, which at sufficient working fluid pressure in the flow path to direct the volume flow of the Working fluid in the first direction - preferably from a reservoir to a hydraulic consumer - finally allows a movement of the shut-off of the first control valve from its open to its closed position a flow of the working fluid in the flow path in the first direction. In the second position of the coupling means of the pilot control means, this movement of the shut-off body of the first control valve is the working fluid pressure acting on the valve inlet and the holding force of the holding means of the first control valve, which preferably comprises a compression spring, directed in opposite directions.

The throttle element dampens the volume flow of the working fluid in the flow connection from the flow path to the valve control port and vice versa, thus when closing and opening the first control valve; a throttle element is usually used to prevent sudden opening and closing of a valve and thus to stabilize or delay the switching movement of the valve and with this the volume flow of the switched working fluid. However, this damping or deceleration by the throttle element proves to be a disadvantage if a fast closing of the valve is desired; Usually, this switching delay is also referred to as dead time, which is defined in the first direction in the case of the control device according to the invention by the time between the actuation of the electrical actuating means and the opening of the check valve in the connected to the first control valve flow path for directing the volume flow of the working fluid. In addition, since the valve control port of the first control valve is connected via the throttle element to the pilot control means, more specifically the first pilot valve, which in turn cooperates with the flow path to direct the volumetric flow of the working fluid through the coupling means and the second pilot valve in the second direction, the dead time is additional depending on the working fluid pressure in this flow path and consequently on the respective output load of a lift controlled by the control device according to the invention. The throttle element provided with the two-part shut-off body or differential piston between the valve control opening via the throttle element and the flow path for guiding the volumetric flow of the working fluid in the first direction thus also prevents, in particular, unwanted transient pressure changes and / or oscillations in the working fluid within the hydraulic line system as a result Opening the first control valve. The minimization of the dead time when closing the first control valve is primarily made possible by the hydromechanical transmission means for mechanically actuating the shut-off on the valve control port. The hydro-mechanical transfer means is in flow communication with the flow path for directing the volumetric flow of the working fluid in the second direction and thus ensures a load-dependent mechanical pre-positioning of the check valve of the first control valve during operation of the control device; the hydromechanical transmission means is designed in the usual way with a hydraulically actuated plunger for converting a hydraulic pressure signal into a proportional mechanical displacement signal. Increasing the working fluid pressure in the flow path for directing the volumetric flow of the working fluid in the second direction relative to the working fluid pressure in the flow path for directing the volumetric flow of the working fluid in the first direction thus always results in an extension movement of the plunger. By a suitable structural assignment to the valve control opening of the first control valve, the plunger is directly mechanically coupled to the shut-off, more precisely to the first Absperrkörperteil, so that the extension movement of the plunger against the holding force of the holding means of the first control valve, the first Absperrkörperteil in the direction of second Absperrkörperteils and consequently shifts the entire shut-off in the direction of the valve inlet opening. From this load-dependent pre-positioning of the shut-off body results in a shift of the operating point of the first control valve according to the pressure conditions currently prevailing in each case in the hydraulic line system of the control device according to the invention. In other words: Due to the load-pressure-dependent pre-positioning of the shut-off body of the first control valve, its travel decreases until the sealing engagement with the third guide means in the area of the valve inlet opening. However, since the closing of the first control valve is effected by the working fluid itself, the working fluid in the second position of the coupling means being closed by the first pilot valve of the pilot control means closed by the electrical actuating means due to the flow in the flow. path for conducting the working fluid in the first direction prevailing pressure to the valve control port and further flows into the first guide means part of the first control valve to effect there the required displacement of the shut-off, also the required working fluid volume is reduced according to the load pressure-dependent pre-positioning of the shut-off , so that it already results in a load pressure-independent or load pressure compensated shortening of the dead time.

As stated above, the actuation of the shut-off of the first control valve by the working fluid via the hydromechanical transmission means at the valve control port of the first control valve with an increase of the working fluid pressure in the supply line to the transfer medium hydraulically indirectly, ie without working fluid entry into the first control valve. In order to exclude the risk of undesirable white space or underpressure formation in the connection region, more precisely in the first guide middle part of the first control valve, and at the same time to further shorten the dead time, in particular in the event of sudden pressure increases, the valve control opening is additionally provided with the flow path for conducting the volume flow of the working fluid connected in the first direction via the check valve. This check valve, which is preferably formed with a compression spring as adjusting means, opens at a defined switching threshold in the direction of supply of the working fluid to the valve control port and blocks the working fluid flow in the opposite direction. Via the check valve is a defined and as far as possible undelayed secondary flow of the working fluid in the first guide means portion of the sten he ^¬ terdruckbildung control valve, avoiding an undesirable or impossible Leerraum-; a white space or negative pressure within a valve is known to lead to unstable switching behavior with undefined switching positions and is therefore to be avoided. The control device according to the invention thus makes possible, in this embodiment, a load-dependent pre-positioning of the shut-off body of the first control valve in the form of a differential piston, in conjunction with a reduction in the value Flow resistance in the inflow to the valve control opening, and a minimization of the time delay when closing the first control valve, regardless of the prevailing in the flow path load-related working fluid pressure, thus a substantially load-independent and dead time-free switching of the bypass valve from the open to the closed position. In a hydraulic drive system for an elevator, the control device according to the invention in this embodiment also enables a substantially delay-free and payload-independent release of the volume flow of the working fluid for a lifting movement of the elevator car, thus a faster start and thus an improvement of the approach quality of the elevator.

The second control valve is preferably formed in the abovementioned embodiment of the control device according to the invention with a one-piece shut-off body and connected via its valve inlet, valve outlet and valve control respectively connected to the flow path. More specifically, this connection is between the valve inlet port and the flow path for conducting the working fluid in the first and second directions, between the valve outlet port and the flow path for conducting the working fluid in the second direction, and between the valve control port and the flow path for conducting the working fluid provided in the first and second direction. The latter flow connection comprises a throttle element for damping the volume flow of the working fluid. A further flow connection is additionally provided within the second control valve in the form of an annular gap between the valve inlet opening and a boundary surface of the one-piece shut-off body facing away from the valve control opening side end, so that via this flow connection and the valve inlet opening on the one hand and the valve control opening on the other hand, acting on the shut-off working fluid pressure two mutually opposite actuating forces for movement of the shut-off between the closed and open position of the second control valve can generate. Furthermore, the valve control opening with the pilot control means, more precisely with the Valve inlet opening of the second pilot valve covered by this connected. This preferably formed via the throttle element connection ensures that the piston of the second control valve is always moved from its closed position to its open position when the coupling means of the pilot control takes its first position; in the first position, the two pilot valves are coupled by the coupling means, so that the second pilot valve is moved by the electrical actuating means of the first pilot valve from its closed position to its open position. Consequently, in the first position of the coupling means of the pilot control means, the working fluid can flow away from the valve control port of the second control valve via the pilot control means, whereby a pressure decrease is connected to the valve control port of the second control valve. With a suitable dimensioning of the provided as an annular gap in the valve flow connection and the two facing away boundary surfaces of the shut-off of the second control valve, one of the valve control and the other of the valve inlet is assigned, is at a sufficient working fluid pressure in the flow path to the line the volume flow of the working fluid in the second direction - preferably from a hydraulic consumer to a reservoir - thus via the valve inlet opening a movement of the shut-off from the closed to the open position of the second control valve and thus a volume flow of the working fluid in the flow path in the second direction allows. In the first position of the coupling means of the pilot control means, this movement of the shut-off body is essentially directed counter to the holding force of the holding means of the second control valve, which preferably comprises a compression spring.

The flow connection of the valve control opening of the second control valve in this embodiment of the control device according to the invention thus configured in a manner configurable by the coupling means of the pilot control means, that in the first position of the coupling means between the valve control port and the flow path for guiding the volume flow the working fluid in the second direction and in the second position of the coupling means between the valve control port and the flow path for directing the volume flow of the working fluid in the first direction respectively via a direct and an indirect flow connection.

Brief description of the drawings

A preferred embodiment of the present invention will be described in more detail below with reference to the accompanying drawings. Show it :

Fig. 1 is a circuit diagram of a hydraulic drive system for an elevator with the control device according to the invention;

FIG. 2 shows the circuit diagram of the control device according to the invention in detail with a hydraulic drive; FIG.

3 shows a side view of a pilot control means in a constructive embodiment as a detail of a control device according to FIG. 2 in a partial section; Fig. 4 is a side view of an embodiment of the invention according to the first

Control valve as an element of a control device of FIG. 2;

Fig. 5 is a sectional view of the first control valve of FIG. 4;

6 shows a side view of an embodiment of the second control valve according to the invention as an element of a control device according to FIG. 2;

FIG. 7 is a sectional view of the second control valve of FIG. 6; FIG.

8 shows the circuit diagram of a further embodiment of the invention ßen control device in detail with a hydraulic drive to drive;

9 is a sectional view of a valve block in a constructive design as a detail of a control device according to FIG .. 8

Detailed description of the invention

The preferred embodiment of the invention shown in the drawings is the best mode. This best mode of the present invention will be described in detail below. In Fig. 1, the electro-hydraulic circuit diagram of a hydraulic drive system 16 is shown for an elevator in which the control of the lifting and lowering movement by the control device 1 according to the invention. Hydraulic elevator systems of this type are used in buildings with several floors, in particular in buildings with up to six floors, and have a movable elevator cage 12, which is suitable for transporting persons and / or goods. As further components, the hydraulic drive system 16 comprises a control device 1 with a valve block 2, which is connected via a flow path 6 in the form of a hydraulic power line usually provided as a pipe connection with a hydraulic cylinder 11 as a hydraulic drive. The hydraulic cylinder 11 is designed as a single-stage drive cylinder and coupled to the elevator car 12, so that a volume flow of a working fluid from the valve block 2 to the hydraulic cylinder 11 causes a lifting movement of the elevator car 12 via an extension of the drive cylinder. By means of a shut-off valve 613 in the hydraulic power line encompassed by the flow path 6, the single-stage drive cylinder can be locked in any extended position, whereby the elevator car 12 is safely stopped in a defined position, for example on the ground floor, in particular during system maintenance or when replacing individual system components can be. In addition, the flow mungspfad 6 between the valve block 2 and the stopcock 613 a flow measuring means 610 for determining the volume flow of the working fluid in both flow directions between a reservoir 10 and the hydraulic cylinder 11. From the valve block 2 of the control device 1, the flow path 6 in the form of the hydraulic power line continues to a pump with motor drive 9, which is designed as a screw pump with an electric motor as a drive, and from there to the reservoir 10 to provide the working fluid. For the return of the working fluid, the valve block 2 is connected directly to the reservoir 10 via a further hydraulic power line comprised by the flow path 6. The return of the working fluid from the hydraulic cylinder 11 via the flow measuring means 610 and the valve block 2 and / or directly from the valve block 2 into the reservoir 10 can be controlled in this way by an electromagnetic actuating means 4 encompassed by the control device 1. The working fluid used is a hydraulic oil based on mineral oil. According to the applicable safety regulations for elevator facilities, the control device 1 according to the invention is also connected to a hydraulic safety line 8, which connects the valve block 2 on the one hand via an emergency discharge valve 82 and the other via a ne hand pump 81 each with the reservoir 10.

For detecting the position of the elevator car 12 along its travel path between the floors, a position detection means 13 is provided in the usual way in the hydraulic drive system 16. This is connected by an electrical signal line see 54 with an elevator control unit 14 which controls on the one hand, the electric motor of the pump 9 by means of an electric power line 15 in response to a position signal generated by the position detection means 13. On the other hand, the elevator control unit 14 generates from the position signal a setpoint value for the elevator car speed, which is connected to the setpoint value by means of a further electrical signal line 54. input of a control device 5 with PID behavior (PID -proportional- integral-differential) is passed. The control device 5 comprises in series a setpoint setting means 51 for converting the setpoint signal generated by the elevator control unit 14, a comparison means 52 having a setpoint input, an actual value input and a difference value output for forming a difference signal as an output from the setpoint signal and the actual value signal and a controller 53 for generating a the controller characteristic corresponding control signal from the difference signal. The input variable supplied to the comparison means 52 of the control device 5 via its actual value input by means of a further electrical signal line 54 is formed by the flow measuring means 610 of the control device 1 from the respective velocity of the volume flow of a working fluid in the flow path 6 as an electrical actual value signal. Via a further electrical signal line 54, finally, the electrical control signal generated in the control device 5 is passed to the electromagnetic actuating means 4 of the control device 1, via a mechanical signal line 55 in the form of a travel the volume flow of the working fluid to and from the hydraulic cylinder 11 as hydraulic drive of the elevator car 12 by means of the encompassed by the control device 1 valve block 2 accordingly. The actual value signal generated in the control device 1 in accordance with the flow rate of the working fluid in the flow path 6 to and from the hydraulic cylinder 11 is thus proportional to the speed of the elevator car 12 in its lifting and lowering movement or up and down travel.

As usual, the movement of the elevator car 12 takes place at two different speeds, namely a higher one for the driving operation between the floors and a lower one for the crawl operation for the exact positioning of the elevator car 12 at the landing, wherein the switching between the two speeds by the control device according to the invention 1 takes place as a function of the position signals of the position detection means 13 during the lifting or lowering movement of the elevator car 12. When driving drove is generated by the elevator control unit 14 in a known manner, in addition to a first electrical signal for high-speed operation, a second electrical signal for creeping. The former is switched off when a floor position defined by the position detection means 13 is reached, while the second signal continues to be applied, which in turn causes the elevator cabin 12 to decelerate. The fine positioning on reaching the floor is then carried out using a limit switch or floor switch, which is located about 1 cm below or above the respective end position. In this way, it is ensured that the elevator car 12 is decelerated to a standstill on reaching the respective switch position both in the upward and in the downhill drive and stops exactly at the predetermined stop position.

In the hydraulic drive system 16, a speed signal is thus generated in a known manner in the elevator control unit 14 as a function of the position of the elevator car 12 detected by the position detection means 13. From this speed specification for the elevator car 12, a desired value signal for the elevator car speed, or for the proportional flow rate of the working fluid, is again formed in the desired value setting means 51 of the control device 5, which is compared with the actual value of the flow rate of the working fluid detected by the flow measuring means 610. If there is a deviation between the actual and desired value of the elevator car speed, the control device 5 delivers a corresponding electrical control signal which actuates the electromagnetic actuating means 4 and controls the volume flow of the working fluid in the flow path 6 by means of the valve block 2, thus the speed of the elevator car 12 In the respective direction of travel increased or reduced accordingly. The hydraulic drive system 16 thus forms a closed loop. In Fig. 2, the circuit diagram of the control device 1 according to the invention in Detail representation indicated with a hydraulic cylinder 11 and a motor-driven pump 9 and a reservoir 10 for the working fluid. In addition to providing the working fluid required for the operation of the control device 1 and the hydraulic drive or hydraulic cylinder 11, the reservoir 10 also serves to receive the working fluid returning from the control device 1 and / or such a consumer. As a working fluid in this case a hydraulic oil is provided based on mineral oil. The valve block 2 comprised by the control device 1 has a hydraulic power unit with a spring-loaded check valve 612, which enables the flow of working fluid in the first direction from the reservoir 10 via the flow measuring means 610 to the hydraulic cylinder 11 in the flow path 6 according to FIG the opposite direction prevented. The check valve 612 defines over the spring constant of its return spring, the threshold value of the working fluid pressure to be overcome by the flow rate of the working fluid to pass through the flow path from the reservoir 10 to the hydraulic cylinder 11. Furthermore, the valve block 2 has an electro-hydraulic control part, which essentially comprises a pilot control means 3.

The valve block 2 is connected in the manner shown in FIG. 1 by means of the flow path 6 in the form of a plurality of hydraulic power lines to the reservoir 10 and via the flow measuring means 610 to the hydraulic cylinder 11. More specifically, as shown in FIG. 2, the flow path 6 includes a first hydraulic power line 601 extending from the reservoir 10 to the inlet of the motor-driven pump 9, a second hydraulic power line 602 connecting the outlet of the motor-driven pump 9 to the inlet port of the check valve 612 a third hydraulic power line 603 extending from the outlet port of the check valve 612 to the hydraulic inlet of the flowmeter 610; a fourth hydraulic power line 604 communicating the hydraulic output of the flowmeter 610 with the inlet of a stopcock 613, and a fifth hydraulic power line 605, which finally establishes the flow communication of the outlet of the stopcock 613 with a working fluid port of the hydraulic cylinder 11. The functional integration of the control device 1 according to the invention in a hydraulic drive system 16 as shown in FIG. 1 via the conduit means 6, 8, 15, 54 and 55 in the manner indicated in Fig. 1, of which the conduit means 6 and 8, the hydraulic power unit and the conduit means 15, 54 and 55 are associated with the electro-hydraulic control part of the valve block 2; the mechanical signal line 55 is in this case designed as a travel of an electric actuating means 4. The hydraulic power unit of the control device 1 according to the invention further comprises a sixth hydraulic power line 606, the first end of which is connected to the second hydraulic power line 602 and the second end of which is connected to the inlet of a first control valve 21; in the embodiment of the first control valve 21 shown in FIG. 4, this connection with the valve inlet 220. The first control valve 21 is a continuously adjustable 2/2-way valve (valve with an open and closed position, or with two switch positions and two hydraulic connections 4 in the form of a cylindrical compression spring, as usual made of spring steel, for closing the valve in its rest position and controls via the working fluid return from the second hydraulic power line 602 via a between the outlet - the Ventilauslassöffnung 221 according to Fig. 4 - the first control valve 21 and the reservoir 10 provided seventh hydraulic power line 607 the working fluid inlet to the hydraulic drive or hydraulic cylinder 11. By this arrangement of the first control valve 21 and a suitable dimensioning of the holding force or spring force of him as shown in FIG 4 includes It is ensured that the first control valve 21 opens when the motor-driven pump 9 is running and at the same time the first pilot valve 31 of the pilot control means 3 is open, so it is in its rest position; the actuation of the first pilot valve 31 is effected by activation of the electrical actuating means 4, as indicated in detail in connection with FIG. 1. The first pilot valve 31 thus causes in its open position a pressure drop in the flow path 6 of a hydraulic Antriebssy- stems 16 of FIG. 1 and thereby prevents a flow in the first direction, ie to the hydraulic cylinder 11, and that until the holding force of in the flow path 6 arranged check valve 612 is overcome by the working fluid pressure. For the return of the working fluid from the hydraulic cylinder 11 into the reservoir 10, the hydraulic power unit of the control device 1 according to the invention on an eighth and ninth hydraulic power line 608, 609, the former with its first end to the third hydraulic power line 603 and with its second end with connected to the inlet of a second control valve 22, which is formed as a 2/2-way differential pressure valve - in the embodiment of the second control valve 22 of FIG. 6, this connection with the valve inlet 220 -, while the latter between the outlet - the Ventilauslassöffnung 221 of FIG. 6 - the second control valve 22 and the reservoir 10 is arranged. By this routing is ensured that the flow measuring means 610, which is provided in a known manner for bidirectional flow measurement, both the flow rate of the working fluid to and from the hydraulic cylinder 11 detected. The hydraulic safety line 8, by means of which an emergency lowering valve 82 and a hand pump 81 are connected as legally prescribed safety components according to FIG. 1 in parallel arrangement with the valve block 2, branches off from the eighth hydraulic power line 608.

In detail, the pilot control means 3 belonging to the electrohydraulic control part of the control device 1 according to the invention comprises, in addition to the first pilot valve 31, a second pilot valve 32, a coupling means 33 The two pilot valves 31, 32 are designed as continuously adjustable 2/2-way valves, wherein the first pilot valve 31 and the electrical actuating means 4 together form a solenoid valve and wherein each of the two pilot valves 31, 32 respectively a mechanical adjusting means in the form of a cylindrical Schraubenfe- or compression spring which holds the respective pilot valve closed in its rest position; Each actuating means acts in each case via the valve control opening on the shut-off body or piston of the respective pilot valve. To the second pilot valve 32 also in the case of an increased hydraulic pressure at its valve control port, in particular in decoupled pelt state such as in a working fluid flow from the motor-driven pump 9 to the hydraulic cylinder 11 and thus during the upward movement of the elevator car 12 in a hydraulic drive system 16 after Fig. 1 occurs to hold securely in its closed position, the adjusting means of the second pilot valve 32 in addition to the compression spring, a conventional hydromechanical transmission means 615 which is connected to the second hydraulic power line 602 and parallel to the compression spring via the valve control opening on the shut-off of Valve acts. This transfer means in the form of a hydraulically decoupled plunger allows a dynamic adjustment of the closing pressure to the respective pressure conditions in the flow path 6 of the working fluid from the reservoir 10 to the hydraulic cylinder 11 and is dimensioned such that the function of the second pilot valve 32 and insofar as the pilot control means 3 in each case reliable si ^¬ is chergestellt. The coupling means 33 is a metallic connecting piece movable back and forth between a first and a second position, which on its side facing the two pilot control valves 31, 32 to be coupled has a coupling region 34 with projections for releasably mechanically connecting the pistons of the two pilot valves 31, 32 in its first position. The piston or shut-off of the first and second Pilot control valves 31, 32 are formed for this purpose in a corresponding manner stem-shaped at their opposite ends, so that in the first position of the coupling region 34 of the coupling means 33 shown in FIG. 2, the two pilot valves 31, 32 releasably connected to each other and synchronously by the electrical Adjusting means 4 are actuated. Alternatively and equally preferably, the coupling means may be in the form of a steel ball, the surface of which forms the coupling region 34, as specified in detail in connection with FIG. 3.

2, the coupling of the two pilot control valves 31, 32 in the first position of the coupling means 33, which in this case is designed as a mechanical connecting means, takes place on the two valve pistons under the action of a defined holding force. The holding force results essentially from the spring force of a cylindrical compression spring and is dimensioned such that the coupling means 33 with its coupling region 34 reliably in its first position enables the synchronous operation of the two pilot valves 31, 32 by the electrical actuating means 4. The synchronous movement of the two valve pistons in the coupling case is ensured in particular by the holding force of the second pilot valve 32 associated adjusting means, which in addition to a compression spring additionally comprises a hydromechanical transmission means 615 in this embodiment; by the inventive design assignment of the two valve piston and the respective actuating means to each other, the holding force of the actuating means of the second pilot valve 32 acts in the direction of movement of the electrical actuating means 4 of the first pilot valve 31 and counteracting its actuating force for actuating the valve piston or shut-off from its open in his Closed position, so that the valve piston of the two pilot valves 31, 32 are mechanically biased against each other. The required restoring force is provided ^¬ by the respective actuating means of the first and second pilot valve 31, 32 ^¬ . The electric adjusting means 4 comprises an electromagnet for generating a setting force, which is dimensioned such that a reliable synchronous Operation of the two coupled pilot valves 31, 32 in any case is possible when the motor-driven pump 9 is turned off.

If the coupling means 33 with its coupling region 34 assumes its second position, the two pilot valves 31, 32 are decoupled, so that each pilot valve 31, 32 can only be actuated by its own actuating means. In other words: In the illustrated embodiment of the control device 1 according to the invention, the second pilot valve 32 is moved by the force of its actuating means in its closed position and held in this position, while the first pilot valve 31 by the electric adjusting means 4 and duell against the holding force of as a restoring means provided compression spring is actuated, as soon as the two pilot valves 31, 32 are decoupled, thus the coupling means 33 provided as mechanical connection means is moved due to an increase of the working fluid pressure in the second hydraulic power line 602 over a defined threshold to its second position.

Specifically, the deflection of the coupling means 33 from its first to its second position indirectly via a plunger by the working fluid against the spring force of the cylindrical compression spring, or the holding force of the coupling means 33, in response to the prevailing in the second hydraulic power line 602 working fluid pressure; The working fluid thus constitutes the force-generating means. The coupling means 33 and the second hydraulic power line 602 are connected by means of a first hydraulic control line 701, the hydro-mechanical transmission means 615 associated with the second pilot valve 32 cooperating with the first hydraulic control line 701 via a seventh hydraulic control line 707 , The coupling of the two pilot valves 31, 32 thus takes place whenever the force generated by the working fluid pressure in the first hydraulic control line 701 via the coupling means 33 falls below a threshold value defined by the holding force, which is regularly at Standstill or during a downward travel of the elevator car 12 in a hydraulic drive system 16 as shown in FIG. 1 is the case when the motor drive of the pump 9 is turned off.

The valve inlet opening of the first pilot valve 31 is connected via a third and second hydraulic control line 703, 702 to the second hydraulic power line 602, which in turn to the control port - the valve control port 219 of FIG. 4 - the first control valve 21 is continued. The second hydraulic control line 702 has, between the branch of the third hydraulic control line 703 and the control opening of the first control valve 21, a throttle element 611 for damping Lastwechebeander fluctuations in the working fluid pressure and is directly connected to the control port of the first control valve 21, so that its operation by the working fluid as a function of the working fluid pressure controllable by means of the first pilot valve 31 in the second hydraulic power line 602. The first control valve 21 is in its rest position by means of the cylindrical compression spring - holding means 209 of FIG. 4 - closed, wherein the spring force is dimensioned such that the working fluid pressure generated by the motor-driven pump 9 in the absence of payload and / or stationary hydraulic cylinder 11 is sufficient to open the first control valve 21 and to bypass the volume flow of the funded by the pump 9 working fluid between the reservoir 10 via the first, second, sixth and seventh hydraulic power line 601, 602, 606, 607 by the first control valve 21, without a volume flow of the working fluid to the hydraulic cylinder 11 takes place.

The inlet of the second pilot valve 32 is connected via a sixth hydraulic control line 706 to a fourth hydraulic control line 704 having its first end to the eighth hydraulic power line 608 and with its second end to the control port - the valve control port 219 of FIG second control valve 22 is coupled; about the effect load fluctuation-induced fluctuations of the working fluid pressure in the fourth hydraulic control line 704 to limit the control opening and in particular to ensure a defined switching behavior when opening the second control valve 22 is a throttle element 611 between the connection of the sixth hydraulic control line 706 and the control opening provided hen. The piston - shut-off body 200 shown in FIG. 6 - of the second control valve 22 is biased for the purpose of reliable closing in its rest position by a cylindrical compression spring - holding means 209 of FIG. 7 - whereby a threshold value for the valve actuation is defined, which at a corresponding Pressure difference of the working fluid in the eighth hydraulic power line 608 and the fourth hydraulic control line 704 is overcome; Thus, if the working fluid pressure at the control port of the second control valve 22 is lower than this threshold, the working fluid in the flow path 6 in a hydraulic drive system 16 of FIG. 1 in the second direction can be more specifically controlled from the hydraulic cylinder 11 to the reservoir 10 by those in FIG shown power line sections 605, 604, 603, 608 and 609 flow.

According to FIG. 7, the second control valve 22 also has a flow connection in the form of an annular gap between its valve inlet opening 220 and its first guide middle part 210, via which the working fluid pressure prevailing at the valve inlet opening 220 impacts the shut-off body 200 - more precisely the conically formed transition area between the first and second Absperrkörperbereich 203, 204 - can act, so that the resulting force is directed counter to the force acting on the shut-off valve 200 via the valve control opening 219 actuating force and causes an actuating movement of the shut-off 200 from its closed to its open position; the flow connection in the form of the annular gap is shown in FIGS. 2 and 8 as the fifth hydraulic control line 705 between the eighth hydraulic power line 608 and the second control valve 22. Finally, for the return of the working fluid from the pilot control means 3 in the Vor- An eighth hydraulic control line 708 between the outlet of the first pilot valve 31 and the reservoir 10 and a ninth hydraulic control line 709 is provided, the latter connecting the outlet of the second pilot valve 32 with the eighth hydraulic control line 708.

Fig. 3 shows the pilot control means 3 shown schematically in Fig. 2 in a constructive embodiment. The pilot control means 3 forms, together with the associated flow connections, the flow measuring means 610 and the electrical signal lines 54, the electrohydraulic control part of the valve block 2 of the control device 1 according to the invention according to FIG. 2. The pilot control means 3 shown comprises in a housing formed as a metal cuboid with bores the first and second pilot valve 31, 32 and the coupling means 33 with the coupling region 34 and the Kraftstoßübertra- means 35 in the form of a plunger, which is slidably mounted in a trained as a cup-shaped guide sleeve force pulse guide means 36 against a compression spring, and an electric actuating means 4 with an electromagnet as an actor. Due to this structural design, the pilot control means 3 is usually referred to as a pilot block. Further bores in the metal cuboid form sections of the flow connections, namely the first, third, sixth, seventh, eighth and ninth hydraulic control line 701, 703, 706, 707, 708, 709, which, according to FIG. 2, control the individual actuators of FIG Serve control device 1; the bores are made of the boundary surfaces of the metal block forth and there leak-proof sealed in a conventional manner by means of expander, where the continuation of a flow connection to the respective boundary surface of the metal block is not provided.

In the variant embodiment of the electrohydraulic control part of the control device 1 according to the invention according to FIG. 3, the electrical actuating means 4 and the two pilot control valves 31, 32 are mounted on a common first actuating element. arranged as shown in connection with FIG. 2. The electric adjusting means 4 is flanged to the corresponding corresponding to the first pilot valve 31 boundary surface of the metal cuboid. A second operating line, on which the coupling means 33 reciprocates with its coupling region 34 between its first and second position under the action of the force impulse transmission means 35 moved analogously by the working fluid as force impulse generating means, intersects the first actuating line perpendicularly between the first and second pilot valves 31, 32, more precisely between the opposing valve piston of the same.

As a coupling means 33, a commercially available steel ball is provided, whose surface comprises the coupling region 34, via which the two pilot valves 31, 32, more precisely their valve piston, cooperate in the first position of the coupling region 34 of the coupling means 33 and can be moved synchronously by the electrical adjusting means 4 , The holding force, which holds the coupling means 33 with the coupling portion 34 in its first position in the starting position, and the restoring force, which it returns to this, is provided substantially by the spring force of a cylindrical compression spring; In the embodiment of the pilot control means 3 according to FIG. 3, a metallic connecting piece between spring and steel ball ensures a defined transmission of force. In an alternative embodiment of the pilot control means 3, the holding and restoring force of the coupling means 33 designed as a steel ball is ensured solely by its weight, and therefore by a suitable dimensioning of the ball mass. This eliminates the additional use of a compression spring and a connector. The components which come into contact with the coupling of the two pilot valves 31, 32 are designed in the usual manner in the respective contact region in such a way that the coupling is possible while avoiding friction as much as possible. This is in the two variants in particular by the use of a steel ball with high surface quality, namely with low surface roughness, high dimensional stability and high mechanical resistance achieved. In both embodiments, the steel ball as coupling means 33 or are this, the connecting piece and the spring each guided in a corresponding bore in the pilot block, which is fluid-tightly closed by means of an adjusting screw and dimensioned so that the movement of the coupling region 34 of the coupling means 33 is ensured in its second position within the bore.

FIG. 4 shows a particularly advantageous embodiment of the first control valve 21 in a side view with a closed valve inlet opening 220. 2 controls the first control valve 21 in this embodiment, the volume flow of the working fluid in the flow path 6 from a reservoir 10 to a hydraulic drive or hydraulic cylinder 11 in bypass operation and may also be referred to as open-valve become. The first control valve 21 is formed in this embodiment as a 2/2-way valve with continuously adjustable differential piston. The shut-off body 200 comprises two substantially circular-cylindrical shut-off body parts 201, 202, each of which is arranged with its respective cylinder axis congruent with the valve longitudinal axis and on the one hand relative to a first, second and third Führungsmittteiles 210, 212, 214 and on the other hand relative to each adjacent Absperrkörperteil is slidably mounted along the valve longitudinal axis. The individual valve components and their functional interaction are explained below in particular with reference to FIG. 5, which shows the first control valve 21 according to FIG. 4 in a sectional view along the section line A-A indicated there.

The two circular-cylindrical shut-off body parts 201, 202 are designed essentially as hollow cylinders in their respective region corresponding to the valve outlet opening 221, wherein the outer and inner diameters are selected such that, in addition to a respectively sufficient mechanical stability, the hollow cylinder enclosed by the first shut-off body part 201 with a fourth shut-off body region 206 partially encloses the hollow cylinder enclosed by the second shut-off body part 202 with a fifth shut-off body region 207. In the hollow cylinder enclosed by the second shut-off body part 202, at least one pressure compensation bore 208 is provided, which connects the thus formed interior of the shut-off body 200 to the outlet area of the first control valve 21 or to the valve outlet opening 221, thus the relative displaceability of the two shut-off body parts 201, 202 to one another ensures in valve operation; since the length of the fourth shut-off body region 206 is shortened relative to the length of the fifth shut-off body region 207 and each pressure compensating bore 208 is arranged outside the possible overlap region in the fifth shut-off body region 207, pressure equalization between the interior and the valve outlet opening 221 of the first control valve 21 is always ensured. In the embodiment of the first control valve 21 of the control device 1 according to the invention shown in FIG. 4 and 5, the valve block 2 is formed with a suitable abutment or stop as Stellwegbegrenzung for the first Absperrkörperteil 201 of Asperr- body 200. In an alternative embodiment of the first control valve 21, a suitable stop for the first shut-off body part 201 is provided directly on the first guide-means part 210 designed as a guide bushing.

By a cylindrical compression spring as holding means 209, which at least partially surrounds both hollow cylinders, without coming into contact with the guide means parts 210, 212, 214, and which the two Absperr- body parts 201, 202 coupled together so that the fourth Absperrkörperbereich 206 of the hollow cylinder of the first Absperrkörperteils 201 overlaps over about half its length with the fifth Absperrkörperbereich 207 of the hollow cylinder of the second Absperrkörperteils 202 in the closed position of the valve and without pressurization of the valve control port 219, the relative displaceability of the two Absperrkörperteile 201, 202 on the one hand in relation on the guide means parts 210, 212, 214 and on the other hand in relation to each other ensured. In this rest position of the holding means 209 of the first control valve 21, moreover, it is ensured by a suitable longitudinal extension of the first guide means part 210 and / or the holding means 209 in each axial direction that the shut-off body 200 does not protrude from the valve control opening 219 with its first shut-off body part 201 ,

By this construction of the first control valve 21 and a design of the holding means 209 used therein, taking into account the minimum occurring at its valve inlet 220 working fluid pressure an automatic or automatic operating point adjustment of the valve is made possible, which is in detail that the shut-off body 200 is capable, on the one hand to pressure fluctuations at the valve control opening 219 or at the valve inlet 220 by a movement of the first or second Absperrkörperteils 201, 202 and on the other hand to a change in the pressure level at the valve control port 219 and / or at the valve inlet 220 by a change in its length or position relative to the valve inlet port 220 and / or the valve control port 219, and thus to the valve outlet port 221, respectively, to respond in a differentiated manner. In the preferred embodiment of the inventive control device 1 according to FIG. 2, this automatic working point ^{setting of} the first control valve 21 enables automatic compensation of load-related changes in the working fluid pressure in the flow path 6 of a motor-driven one Pump 9 to a hydraulic drive or hydraulic cylinder 11 occur and can act in detail on the sixth hydraulic power line 606 and the valve inlet port 220 and / or via the third hydraulic control line 703 and the valve control port 219 on the off ^¬ locking body 200 of the valve. Compared to known control devices, this results in the significant advantage that an optimal starting behavior of the elevator car 12 in a hydraulic drive system 16 according to FIG. 1 for each lift load up to the respectively permissible maximum load, or from the minimum to the maximum load pressure, equally ensured; conventional drive systems of the type mentioned are usually preset to operate with a medium load pressure, so that any deviation of the actual load pressure from the preset mean target load pressure leads to a reduction in the approach quality of the elevator, namely a jerky start at load pressures below and to a startup delay at Load pressures above the target load pressure.

For this automatic operating point setting, the holding force of the holding means 209, or the pressure spring of the first control valve 21, is preferably selected such that the working fluid pressure already generated at the start of the motor-driven pump 9 is already present in the flow path 6 according to FIG second hydraulic power line 602 of FIG. 2 - not only sufficient to move the coupling means 33 from its first to its second position as indicated above, but also to open the first control valve 21, so the second Absperrkörperteil 202, without simultaneously the first Absperrkörperteil 201, and thus to allow a backflow of the working fluid into the reservoir 10 in the bypass mode; by this determination of the holding forces of the coupling means 33 and the holding means 209 thus the minimum circulation or pilot pressure of the working fluid is defined in the hydraulic system. Complete penetration of the hollow cylinder of the second shut-off body part 202 into the hollow cylinder or the bore of the first shut-off body part 201-and thus a rigid coupling of the two shut-off body parts 201, 202 -is only at a load pressure of the working fluid at the valve inlet opening 220 and / or at the valve control opening 219, that is to say in the sixth hydraulic power line 606 and / or in the second hydraulic control line 702 of the control device 1, which is suitable for overcoming the holding force provided by the compression spring provided as holding means 209 with corresponding shortening of the spring length. The valve body is used in the embodiment illustrated in FIGS. 4 and 5. of a first guide bushing 210, whose free end defines the valve control opening 219, of a second guide bushing 214 whose free end defines the valve inlet port 220 and of three equidistantly extending guide pins 212 whose free interstices define the valve outlet port 221, educated. Each of the guide pins 212 is fixedly connected to the first and second guide bushes 210, 214. The two guide bushes 210, 214 of this embodiment of the first control valve 21 are turned steel parts with locating holes for the guide pins 212; Alternatively, the guide bushes 210, 214 of a valve formed in this way may equally be formed of die-cast metal or any other material commonly used for hydraulic valves. The guide pins 212 are made of commercially available semi-finished steel rod material only by appropriate cutting to length, the semi-finished next to a suitable diameter already have the required surface finish. The receiving holes are sized to secure a reliable, firm press fit between each guide bush 210, 214 and each guide pin 212. Although the fixed connection between guide bushes and guide pins is produced by compression in this valve embodiment, it may still be appropriate in certain cases, other common connection types such as bonding and / or screwing for establishing the firm connection between the three guide means parts 210, 212, 214 apply.

The formed as a guide bush third guide means portion 214 has in its adjacent to the second guide middle portion 212 area, or in which, also provided in the form of a guide bushing first guide means 210 facing end side, and the adjacent thereto third guide means portion 215 between the mounting holes for the guide pins of second guide means portion 212 Y-shaped recesses 216 each of approximately the depth of the mounting holes. The Y-shaped recesses 216, which are designed here as counterbores, are set in each case a triangular and a slit-shaped recess together and are oriented with the latter to the inlet of the valve 220 out. The recesses ensure a largely constant volume flow change when switching between the closed position and the open position of the first control valve 21 in the control device 1. To reinforce this advantageous effect, the second guide means 212 and the shut-off body 200 facing edge of the third guide means portion 214 is also provided with a chamfer , The guide bushes, which are encompassed by the first and third guide center parts 210, 214, are chamfered at their mutually facing ends, which enclose the valve control opening 219 and the valve inlet opening 220, in the edge region in order to be installed in the respective valve seat, which is formed as a bore in the valve block 2 is to facilitate; the valve block 2 is provided in the form of a metallic cuboid with recesses and bores for the respective flow connections. The first and second shut-off body part 201, 202 of the shut-off body 200 of the first control valve 21 are made as turned parts made of steel and formed at their ends facing away from each other substantially as a flat solid cylinder whose lateral surfaces in the region of their respective largest outside diameter, the first and second Absperrkörperbereich 203, Form 204 and cooperating with the first and second guide means region 211, 213 of the guide means, wherein the required surface quality is generated in each case by rolling. In the same way, the provided for mutual sliding cooperation hollow cylinder jacket surfaces of the two Absperrkörperteile 201, 202 are processed, which include the fourth and fifth Absperrkörperbereich 206, 207. The first shut-off body part 201 cooperates in this way via a first Absperrkörperbereich 203 with a corresponding first guide means portion 211 of the formed in the form of a guide bush first guide means part 210, while the second Absperrkörperteil 202 via a second Absperrkörperbereich 204 with a corresponding second guide means portion 213 of the second Guide means portion 212 in the form of the contact lines with the three guide pins cooperates. The front end of the second Absperrkörperteils 202 is formed by a third Absperrkörperbereich 205 whose diameter is between the opening diameter of the valve and the maximum diameter of the second Absperrkörperteils 202 and at its front boundary edge for sealing abutment against the third guide means region 215 in the closed position of the valve is chamfered. This third Absperrkörperbereich 205 corresponds so far with the third guide means region 215 without cooperating with this sliding. The third guide means region 215 is encompassed by the third guide means part 214, which is likewise designed in the form of a guide bushing. This guide bush has at its front end a recess in which a self-positioning annular sealing insert 217 is mounted flush by means of an O-ring 218; the sealing insert 217 is manufactured as a turned part made of steel, the O-ring 218 in a conventional manner from a suitable elastomer, such as synthetic rubber such as NBR (nitrile-butadiene rubber). The O-ring 218 is for this purpose of a groove within the jacket surface of the sealing insert

217 received, which has a relation to the O-ring cross-section slightly enlarged cross-section. The recess for receiving the sealing insert 217 is also formed with a relative to the outer diameter of a slightly larger inner diameter and serves the O-ring

218 as an abutment against which it rests under tension. The end face of the third guide means region 215 configured in this way can thus sealingly cooperate with the third shut-off body region 205 of the shut-off body 200 in the closed position of the first control valve 21 in the form of the sealing insert 217, whereby the annular edge of the sealing insert 217 closest to the shut-off body 200 passes through Embossing is generated, forms the contact line and whose inner diameter defines the opening diameter of the first control valve 21. By this type of attachment, the sealing insert 217, particularly in the event of damage, particularly simple ausge- be changed, which affects not only advantageously on the maintenance costs, but also on the valve life.

FIG. 6 shows a side view of a particularly advantageous embodiment of the second control valve 22 with the valve outlet opening 221 closed. This is shown in Fig. 7 in section along the section line B-B of FIG. 6. In this constructive embodiment, the second control valve 22 corresponds in its essential components to the preferred first control valve 21 according to FIGS. 4 and 5, with the difference that the shut-off body 200 is not made as a two-part differential piston, but in one piece. With the second control valve 22 shown in FIGS. 6 and 7, in the inventive control device 1 according to FIG. 1, the volume flow of the working fluid in the flow path 6 in the form of the hydraulic power line is controlled by a hydraulic drive or hydraulic cylinder 11 back into a reservoir 10 why the second control valve 22 may also be referred to as Ab valve. With respect to the first, second and third guide means part 210, 212, 214 with the respectively associated first, second and third guide means region 211, 213, 215 and with respect to the properties of the first, second and third Absperrkörperbereichs 203, 204, 205 of the Absperrkörpers 200 thus fully 4 and 5, the one-piece shut-off body 200 and the valve function resulting therefrom will be explained in detail below.

The shut-off body 200 of the second control valve 22 according to FIGS. 6 and 7 is made in one piece in the form of a circular cylinder with different diameters along the cylinder longitudinal axis as a turned part made of steel. For sliding cooperation with the respectively corresponding first and second guide means region 211, 213 of the first and second guide means part 210, 212 and for cooperation with the corresponding third guide means region 215 of the third guide means part 214 in the closing Position of the valve, the cylinder longitudinal axis is congruent with the valve ^¬ longitudinal axis. The shut-off body 200 has at its valve control opening 219 associated with the end of the first Absperrkörperbereich 203 the largest outer diameter. With the third shut-off body region 205, the shut-off body 200 is assigned to the valve outlet opening 221, so that the second shut-off body region 204 is located between the first and third shut-off body regions 203, 205. The outer diameter of the shut-off body 200 is reduced in the second shut-off body region 204 in relation to that in the first shut-off body region 203, while that in the third shut-off body region 205 is reduced compared to that in the second shut-off body region 204. In addition, in the third shut-off body region 205, the diameter of the shut-off body 200 corresponding to the first control valve 21 is greater than the opening diameter of the valve. Corresponding thereto, the inner diameter of the first guide means part 210 is greater than that of the second guide means part 212, whose inner diameter is in turn larger than that of the third guide means part 214; the inner diameter of the second guide middle part 212 is determined by the contact lines of the three guide pins with the shut-off body 200, which are arranged circularly and in a radial arrangement about the valve longitudinal axis. In the transition region between the first and second shut-off body region 203, 204 and between the second and third shut-off body region 204, 205, the shut-off body 200 is provided with a chamfer, wherein these chamfers are arranged along the longitudinal axis of the valve body such that no contact between the respective chamfer region and the first and third guide means part 210, 214 in the closed position of the valve. In order to further reduce the friction between the shut-off body 200 and the first and second guide middle part 210, 212, the shut-off body regions 203, 204, which in a movement of the shut-off body 200 slidingly cooperate with the corresponding guide means regions 211, 213, also in terms of their size Effective area adapted to each other. For this reason, in the embodiment of the second control valve 22 shown in FIGS. 6 and 7, the second shut-off body region 204 is partially designed with a smaller outer diameter. The third Absperrkörperbereich 205 is also chamfered at its the Ventilauslassöffnung 221 facing end, whereby the shut-off body 200 in its closed position, the self-positioning annular sealing insert 217 of the third guide means portion 214, which is corresponding to that of the first control valve 21, along a circular valve outlet opening 221 enclosing the contact line sealingly touched. At this bevel joins in a centric arrangement a stem-shaped piston part which is dimensioned so that it protrudes in each position of the shut-off 200 from the Ventilauslassöffnung 221 and its shape in a known manner with regard to optimum utilization of the flow forces occurring during valve operation and thus is set to an improvement of the switching behavior of the second control valve 22. The shut-off body 200 of the second control valve 22 shown in FIG. 6 and 7 is biased by a mechanical holding means 209 in the form of a cylindrical compression spring in the direction of the valve outlet 221, so that the second control valve 22 is closed in the pressureless state; serves as an abutment for the spring in the control device 1 according to the invention - as already mentioned in connection with the first control valve 21 - the valve block 2. To accommodate the compression spring, the shut-off body 200 of the second control valve 22 at its the valve control port 219 associated end with a central bore a first diameter which ends approximately in the chamfer region between the first and second shut-off body region 203, 204. An adjoining region with a second diameter, which is slightly reduced compared to the first, serves to center the compression spring. The bore continues with a third diameter reduced in relation to the second diameter and ends in the region of the fastened end of the third shut-off body region 205. The first, second and third bore diameters are in each case selected so that the shut-off body 200 extends approximately over its entire length same wall thickness, without to be endangered by its mechanical stability. The thus enabled more reliable positioning of the holding means 209 and the weight saving effect an improvement of the dynamic switching behavior of the second control valve 22. In Fig. 8, the circuit diagram of another embodiment of the control device 1 according to the invention with a motor-driven pump 9, a reservoir 10 and a hydraulic drive or Hydraulic cylinder 11 and a flow path 6 according to FIG. 1, which in detail the power line sections 601 to 609 for the conduction of a working fluid as shown comprises reproduced reproduced. This embodiment is an advantageous development of the control device according to FIG. 2. It differs from the latter in the type of flow connection between the control connection - valve control opening 219 according to FIG. 5 - the first control valve 21 and the flow path 6 with otherwise matching characteristics and allows a substantially load pressure independent and dead time-free closing of the first control valve 21. The statements made in connection with Fig. 2 are to be used in this respect supplementary to the following explanation of this further aspect of the invention. The flow connection between the control connection - valve control opening 219 according to FIG. 5 - of the first control valve 21 and the flow path 6 according to FIG. 1 is formed according to FIG. 2 in the form of the second hydraulic control line 702 with the throttle element 611, which is connected to the flow path 6 included second hydraulic power line 602 is connected; a branch between this connection and the throttle element 611 establishes the working fluid flow via the third hydraulic control line 703 to the inlet of the first pilot valve 31 of the pilot control means 3. The second hydraulic power line 602 is connected via the check valve 612 to the third hydraulic power line 603, so that in the second hydraulic power line 602 only a volume flow of the working fluid in the first direction and in the third hydraulic power line 603 both a Volumetric flow of the working fluid in the first and in the second direction is possible; Although preferred, the check valve 612 for restricting the flow direction of the working fluid in the second hydraulic power line 602 of the control device 1 according to the invention according to FIG. 2 is not absolutely necessary, since it can also be provided, for example, by a suitable pressurization of the working fluid itself by means of the motor-driven pump 9 be replaced. In the control device 1 according to FIG. 2, the control connection - valve control opening 219 according to FIG. 5 - of the first control valve 21 is thus connected only to the flow path 6 for conducting the working fluid from the reservoir 10 to the hydraulic cylinder 11.

In the further development of the control device 1 according to FIG. 8, however, the control connection has both a flow connection with the second hydraulic power line 602 and with the third hydraulic power line 603, so that consequently not only the working fluid pressure within the flow path 6 or in the Power lines 601, 602, 603, 604 and 605 for directing the volume flow of the working fluid in the first direction from the reservoir 10 to the hydraulic cylinder 11 to the control port - valve control port 219 of FIG. 5 - the first control valve 21 acts, but also in the Power lines 605, 604, 603, 608 and 609 for conducting the working fluid in the second direction of the hydraulic cylinder 11 back into the reservoir 10 prevailing working fluid pressure. By this hydraulic circuit configuration is thus the load pressure-dependent pre-positioning of the piston - shut-off 200 according to FIG. 5 - the first control valve 21, and its load pressure compensated operating point setting, ensured.

The flow connection of the control connection - valve control opening 219 according to FIG. 5 - of the first control valve 21 with the second hydraulic power line 602 takes place on the basis of a tenth hydraulic control line 710, which has a throttle element 611 and a filter 614 in a serial arrangement. The throttle element 611 is designed so that an undesirable sudden opening of the first control valve 21 is prevented with a corresponding increase in the working fluid pressure in the second hydraulic power line 602 by a defined damping of wegge from his control port directed volumetric flow of the working fluid. With the filter 614 potential impurities in the working fluid, such as solid particles, in particular kept away from the throttle element, thus preventing potential switching disturbances of the first control valve 21 by such impurities; Since the throttle effect of the filter 614 is negligible compared to that of the throttle element 611, the tenth hydraulic control line 710 essentially corresponds to the second hydraulic control line 702 of the embodiment of the control device 1 according to FIG. 2.

Of the tenth hydraulic control line 710, an eleventh hydraulic control line 711 branches off in the region between the filter 614 and the throttle element 611, which in turn is connected to the control connection - valve control opening 219 according to FIG. 5 - of the first control valve 21 via a spring-loaded check valve 612 in the forward direction , This check valve 612 thus controls the volume flow of the working fluid from the second hydraulic power line 602 through the tenth and eleventh hydraulic control lines 710, 711 to the control port of the first control valve 21 via the defined holding force of the return spring comprised by it, while a corresponding volume flow in prevents the opposite flow direction. The flow connection of the control connection with the third hydraulic power line 603 for load-pressure-dependent pre-positioning of the piston - shut-off body 200 according to FIG. 5 - of the first control valve 21 is in the form of a twelfth hydraulic control line 712, which at its end associated with the first control valve 21 is a hydromechanical - Has nice transmission means 615 conventional design with a spring-loaded, hydraulically actuated plunger. The hydromechanical transmission By means of a longitudinal or outward movement of its tappet, the means 615 converts the working fluid pressure generated by the hydraulic cylinder 11 at standstill or during its lowering movement as a function of the respective payload into a proportional path signal; the working fluid pressure prevailing in the fifth, fourth and third hydraulic power lines 605, 604, 603 and in the flow path 6 according to FIG. 1 for directing the volume flow of the working fluid in the second direction is via the twelfth hydraulic control line 712 at the hydraulic connection of the hydromechanical Transmission means 615 on. The plunger and the piston of the first control valve 21 - of the first shut-off body part 201 of the shut-off body 200 according to Fig. 5 - are axially aligned with the respective centric co-operation (see Fig. 9) and due to the holding force of the cylindrical compression spring - holding means 209 of FIG - The first control valve 21 coupled to each other without play. This ensures optimum force transmission between the hydromechanical transmission means 615 and the first control valve 21 and ensures that an increase in the working fluid pressure at the hydraulic connection of the hydromechanical transmission means 615 causes a proportional longitudinal displacement of the piston, or the first shut-off body part 201 in the direction of the second Absperrkörperteils 202 of the shut-off 200 in its formation as a two-piece differential piston according to FIG. 5, and thus a loaddruckabhängi- ge pre-positioning of the shut-off 200 allows. The travel of the plunger is in the formation of the first control valve 21 of FIG. 5 so far determined by acting on the hydraulic cylinder 11 payload and the spring constants of the holding means 209 and in particular the hydromechanical transmission means 615 and by the maximum travel of the shut-off body 200 and so dimensioned so that it does not exceed half the maximum travel of the shut-off body 200. This load-pressure-dependent pre-positioning can thus be carried out with simultaneous supply of working fluid into the first control valve 21 via the eleventh hydraulic control line 711 by means of a synchronization. chronisierung the adjusting movements of the hydromechanical transmission means 615 and the check valve 612 via a suitable adjustment of the spring constants of the two return springs, so that an undesirable Leerraum- or underpressure due to an actuating movement of the piston in the valve control port 219, more precisely within the first guide means part 210 of the first Control valve 21 of FIG. 5, can be excluded. The development of the control device 1 according to the invention according to FIG. 8 thus enables via the twelfth hydraulic control line 712 a load pressure-dependent dynamic adaptation of the travel of the piston or shut-off body 200 of the first control valve 21 according to FIG. 5 between the open and the closed position. In conjunction with the substantially undamped inflow of the working fluid to the control connection or valve control inlet 219 via the eleventh hydraulic control line 711, thus bypassing the tenth hydraulic control line 710 with the throttle element 611, this results in a largely load-independent shortening of the dead time when closing the This faster closing in turn causes a faster opening of the check valve 612 in the flow path 6 in a hydraulic drive system 16 shown in FIG. 1 and finally a faster extension of the piston of the hydraulic drive 11 designed as a hydraulic drive. In a hydraulic drive system for an elevator, the control device 1 according to the invention in this embodiment thus also enables, in particular, a faster start-up and thus an improvement in the starting quality of the elevator.

Finally, FIG. 9 is a sectional view of a structural design of the valve block 2 corresponding to the circuit diagram of the control device 1 shown in FIG. 8. The valve block 2 is formed with a housing produced as a cuboid in the metal casting method with openings formed therein and six rectangular boundary surfaces and comprises as functional ^¬ nelle unit in each releasable connection the pilot control means 3 in the form of a pilot block according to FIG. 3 and a transmission medium block with the hydromechanical transmission means 615 and the throttle element 611, the check valve 612 and the filter 614. Between the base and congruent with this congruent surface or top surface of the housing extends within the inventive control device 1 extending part of the second hydraulic power line 602 and the third hydraulic power line 603 with the check valve 612 arranged therebetween in the flow direction; The latter prevents a volume flow of the working fluid through the second hydraulic power line 602 in the second direction. For leak-proof connection of the further section of the second hydraulic power line 602 running between the control device 1 according to the invention and the motor-driven pump 9 according to FIG. 8, the base surface of the housing of the valve block 2 has threaded holes which allow a corresponding screw connection. Such threaded bores are also provided in the top surface of the housing of the valve block 2 in order to securely secure the flow meter 610 provided thereon according to FIG. 8, in fluid communication with the third hydraulic power line 603.

In the third hydraulic power line 603, the second control valve 22 in the embodiment according to FIG. 7 extends from the boundary surface adjoining the base surface towards the congruent boundary surface or side surface of the housing, the valve control opening 219 being associated with the side surface, thus the movement of the shut-off body 200 is orthogonal to the direction of the volume flow of the working fluid through the valve block 2 and against the holding force of the formed as a cylindrical compression spring holding means 209. In which the valve control opening 219 comprehensive side surface of the housing of the valve block 2 threaded holes are provided, in which the pilot control means 3 is screwed under leak-safe concern to the side surface of the housing in the area serving as a valve seat for the second control valve 22 bore. In conjunction with the adapted to the axial length of the guide means bore depth limited Piloting means 3 in this way the axial mobility of the shut-off body 200 of the second control valve 22 and thus ensures its defined position within the valve block 2 safely. In addition, the pilot control means 3 forms the abutment for the holding means 209 of the second control valve 22 and thus enables a reliable closing of the valve outlet opening 221 in the rest position of the shut-off body 200.

From the congruent side surface of the housing, the first control valve 21 in the embodiment according to FIG. 5, whose valve control opening 219 is associated with this side surface, extends in the direction of the second hydraulic power line 602 and in fluid communication therewith via the sixth hydraulic power line 606 The first and second Absperrkörperteils 201, 202 of the shut-off body 200 is carried out at the first control valve 21 so far orthogonal to the direction of the flow rate of the working fluid through the valve block 2 and against the holding force of the formed as a cylindrical pressure spring holding means 209. The first control valve 21 comprehensive Side surface of the housing of the valve block 2 is provided according to the congruent side surface with the second control valve 22 in the region around the valve seat with threaded holes on which the transmission medium block with hydromechanical transmission means 615, Drosselele ment 611, check valve 612 and filter 614 in the same manner as the pilot control means 3 leak-tightly screwed to the housing of the valve block 2. The transmission medium block is like the pilot control means 3 formed with a metallic housing in cuboid shape. This has in its the valve block 2 facing boundary surface on a blind bore in which the hydromechanical transmission means 615 is mounted with its plunger aligned with the valve block 2, and each a receiving bore for the throttle element 611, the check valve 612 and the filter 614. The screw provides In this case, a play-free, respectively central coupling between the end faces of the first Absperrkörperteils 201 and the plunger in conjunction with the opposing holding forces of the holding means 209 of the first control valve 21 and the holding means of the hydromechanical transmission means 615 sure. The openings formed in the housing of the valve block 2 in the casting method form the sections of the flow path 6 encompassed by the control device 1 according to FIG. 8 for directing the volume flow of the working fluid in the first and second direction, namely a section of the second, third, seventh and ninth hydraulic power lines 602, 603, 607, 609 and the sixth and eighth hydraulic power lines 606, 608.

The control lines within the housing of the valve block 2, as well as the valve seats of the first and second control valve 21, 22 and the check valve 612 between the second and third hydraulic power line 602, 603, designed as bores. 8, the housing of the valve block 2 also in each case in each case a portion of the first, fifth to tenth and twelfth hydraulic control line 701, 705, 706, 707, 708, 709, 710, 712 and the third and fourth hydraulic control line 703, 704 on. Each other portion of the first, fifth and sixth hydraulic control lines 701, 705, 706 in the pilot control means 3, the eleventh hydraulic control line 711 and a respective further portion of the tenth and twelfth hydraulic control lines 710, 712 in the transmission medium block on the same Formed manner and connected to the respective other line section leak-free by the specified respective screw connection; the flow connections provided in the form of bores are in each case carried out by the boundary surfaces of the respective cuboid metal housing and are leakproof there in the conventional manner by means of expanders, where their continuation at the respective boundary surface of the metal block is not provided. Thanks to its modular design, the valve control block 2 is thus not only space-saving and inexpensive to produce, but is also distinguished in particular by its ease of maintenance and correspondingly low maintenance costs. LIST OF REFERENCE NUMBERS

1 control device

2 valve block

21 first control valve

22 second control valve

200 shut-off body

201-202 first to second shut-off body part

203-207 first to fifth shut-off area

208 Pressure compensation hole

209 holding means

210 first guide middle part

211 first guide means area

212 second guide middle part

213 second guide means area

214 third guide middle part

215 third guide means area

216 recess

217 sealing insert

218 O-ring

219 Valve control opening

220 valve inlet opening

221 Valve outlet opening

3 pre-tax funds

31 first pilot valve

32 second pilot valve

33 coupling agent

34 coupling area

35 impulse transmission means

36 power steering means

4 electric actuator

5 control device 51 setpoint adjustment means

52 comparison means

53 controllers

54 electrical signal line

55 mechanical signal line

6 flow path

601-609 first to ninth hydraulic power line

610 flowmeter

611 throttle element

612 check valve

613 stopcock

614 filters

615 hydromechanical transmission means 7 hydraulic control line

701-712 first to twelfth hydraulic control line 8 hydraulic safety line

81 hand pump

82 emergency lowering valve

9 pump with motor drive

10 storage containers

11 hydraulic cylinders

12 elevator car

13 position detection means

14 elevator control unit

15 electrical power line

16 hydraulic drive system

Claims

claims

A control device (1) for a working fluid for operating a hydraulic drive (11) comprising a flow path (6) for conducting a volume flow of the working fluid in a first and in a second direction, a first and second control valve (21, 22 ) for controlling the volume flow in the flow path (6), a flow measuring means (610) for detecting the volume flow in the flow path (6), a comparison means (52) for comparing the detected volume flow with a predeterminable volume flow setpoint and a pilot control means (3) for actuating the first and second control valves (21, 22), wherein the flow path (6), the flow measuring means (610), the comparison means (52), the pilot control means (3) and the first and second control valves (21, 22) a control loop for the maintenance of the volume flow of the working fluid in the flow path (6) in dependence on the volumetric flow setpoint and the pilot control means (3) a first and second s pilot control valve (31, 32) for controlling the first and second control valves (21, 22), characterized in that the pilot control means (3) comprises an electrical actuating means (4) for actuating and a coupling means (33) for coupling respectively the first and second control valves second pilot valve (31, 32), wherein the coupling means (33) is formed with a coupling region (34) for reciprocating between a first and a second position, wherein in the first position the first and second pilot valves (31, 32 ) are coupled by the coupling region (34) and actuated by the electrical adjusting means (4), so that the second control valve (22) allows the volume flow of the working fluid in the flow path (6) in the second direction, and wherein in the second Position the first and second pilot valve (31, 32) are decoupled and only the first pilot valve (31) by the electrical actuating means (4) is actuated, so that the first control valve (21) allows the flow of the working fluid in the flow path (6) in the first direction.

2. A control device according to claim 1, characterized in that for reciprocating the coupling region (34) of the coupling means (33) between the first and the second position, a force generating means for generating a force impulse and a Kraftstoßführungsmittel (36) having a first and a second end for guiding the force impulse from the first via the second end to the coupling means (33), wherein the force generation means and the force impulse guiding means (36) are formed in such a way that the coupling region (34) of the coupling means (33) is moved from its first to its second position by a force generated by the force impulse generating means and by the Kraftstoßführungsmittel (36) on the coupling means (33), so that the coupling region (34) of the coupling means (33) of the first and second Pilot valve (31, 32) is decoupled.

A control device according to claim 2, characterized in that the force impulse guiding means (36) comprises a force impulse transmitting means (35), preferably a compression spring loaded plunger, for indirectly mechanically transmitting an impulse of force generated by the impulse generating means to the coupling means (33), the impulse transmission means (35 ) and the power joint guiding means (36) for sliding cooperation are formed in such a manner that the coupling portion (34) of the coupling means (33) is generated by the force generating means (35) from the first end via the second end of the power joint guiding means (35). 36) can be moved from the first to its second position on the coupling means (33) so that the coupling region (34) of the coupling means (33) is decoupled from the first and second pilot valves (31, 32).

4. Control device according to claim 2 or 3, characterized in that the force impulse guiding means (36) see at its first end a hydraulic connection area for the flow connection with the flow path (6). such that the force pulse for reciprocating the coupling portion (34) of the coupling means (33) between the first and second positions is producible by the volume flow of the working fluid in the flow path (6), the force generating means being in the form of the working fluid is.

5. Control device according to one of the preceding claims, characterized in that the coupling region (34) of the coupling means (33) from the surface of a spherical body, preferably a steel ball is included.

6. Control device according to one of the preceding claims, characterized in that the electrical adjusting means (4) comprises an electromagnetic or piezoelectric actuator or a stepping motor for the actuation of the first and second pilot valve (31, 32).

7. Control device according to one of the preceding claims, wherein the first and second control valve (21, 22) each have a valve inlet (220), a Ventilauslassöffnung (221) and a valve control port (219) for respective flow communication with the flow path (6), one between an open and closed position reciprocating shut-off body (200) for controlling the volume flow of the working fluid in the flow path (6), a guide means for guiding the shut-off body (200) between the open and the closed position and a holding means (209), preferably a spring, for exerting a holding force on the shut-off body (200) in the direction of the closed position, characterized in that the guide means and the shut-off body (200) each having a plurality of corresponding areas for sliding cooperation in the reciprocating movement of the shut-off (200 ), wherein the guide means in each case in aufeinande a subsequent arrangement of a first guide means (210) with a first guide means region (211), a second guide means part (212) a second guide means portion (213) and a third guide means portion (214) having a third guide means region (215) each in a fixed connection, wherein the first and third guide means part (210, 214) respectively for enclosing the respective corresponding part of the shut-off (200) is formed and the second guide middle part (212) each comprise a plurality of pins in parallel alignment with the direction of movement of the shut-off body (200) such that reciprocation of the shut-off body (200) relative to the guide means is in sliding cooperation with the first and second Guiding means region (211, 213) and sealing cooperation with the third guide means region (215), wherein the second guide means region (213) comprises a part of the surface of at least one of the pins, and wherein the respective first guide means part (210) the valve control opening (219) , the second leading party l (212) the valve outlet opening (221) of the first control valve (21) and the valve inlet opening (220) of the second control valve (22) and the third guide middle part (214) the valve inlet opening (220) of the first control ^¬ valve (21) and form the valve outlet opening (221) of the second control valve (22), and wherein the valve control opening (219) of the first and second control valves (21, 22) is in each case in flow connection with the pilot control means (3), so that the second control valve (22) in the first position of the coupling means (33) allows the volume flow of the working fluid in the flow path (6) in the second direction and the first control valve (21) in the second position of the coupling means (33) the volume flow of the working fluid in the flow path (6) in the first direction.

8. Control device according to claim 7, characterized in that the guide means of the first and second control valves (21, 22) with a from the first to the third guide means part (210, 212, 214) decreasing or increasing inner diameter and the respective shut-off body (200), respectively a corresponding first, second and third Absperrkörperbereich (203, 204, 205) each having a corresponding outer diameter ausgebil- det, so that the reciprocating movement of the shut-off body (200) of the first and second control valves (21, 22) relative to the respective guide means of the third or the first guide means part (214, 210) can be limited.

9. Control device according to claim 7 or 8, characterized in that the third guide means part (214) of the first and second control valve (21, 22) in each case in its adjacent to the second guide means part (212) region a plurality of recesses (216), preferably U-, V- and / or Y-shape, and / or a bevel, so that the movement of the respective shut-off body (200) within the third guide means part (214) a continuous change of the effective area of the valve inlet opening (220) the first control valve (21) and the Ventilauslassöffnung (221) of the second control valve (22).

10. Control device according to one of claims 7 to 9, characterized in that the third guide means part (214) of the first and second STEU ^¬ erventils (21, 22) in its respective third guide means region (215) ei ^¬ NEN self-positioning annular sealing insert (217) for sealingly cooperating with the respective shut-off body (200) in closing the valve inlet opening (220) of the first control valve (21) or the valve outlet opening (221) of the second control valve (22) in each releasable connection, the sealing insert (217) in a manner is formed so that it sealingly contacts the third shut-off body region (205) of the shut-off body (200) in the closed position of the respective control valve (21, 22) along a circular contact line.

11. Control device according to one of claims 7 to 10, characterized in that the shut-off body (200) of the second control valve (22) is integrally formed and by the holding force of the holding means (209) for co-operation with the guide means in its direction of movement to the third Guide member (214) is biased towards, so that the holding force of the holding means (209) counteracts a movement of the shut-off (200) from the closed to the open position.

12. Control device according to claim 11, characterized in that the second control valve (22) with its valve inlet opening (220) and valve control opening (219) in flow communication with the flow path (6) for directing the volume flow of the working fluid in the first and second directions and its valve outlet opening (221) is provided with the flow path (6) for directing the volume flow of the working fluid in the second direction, so that by the pilot control means (3) in the first position of its coupling means (33) enabled lowering of the pressure in the working fluid the valve control opening (219) via a movement of the shut-off (200) of the second control valve (22) from its closed to its open position causes a flow of the working fluid in the flow path (6) in the second direction.

13. Control device according to claim 11 or 12, characterized in that the shut-off body (200) of the second control valve (22) at its the third guide means (214) associated end has a stem-shaped projection, wherein the stem-shaped projection is formed in a manner in that the shut-off body (200) is movable in the direction of the holding force of the holding means (209) by a volumetric flow of the working fluid directed from the second to the third valve opening (220, 221) after it leaves the third valve opening (221).

14. Control device according to one of claims 7 to 10, characterized in that the shut-off body (200) of the first control valve (21) in several parts, preferably in two parts, with a first and second Absperrkörperteil (201, 202) is formed, wherein the first Absperrkörperteil ( 201) the first and a fourth shut-off body region (203, 206) and the second shut-off body Part (202) the second and third and a fifth Absperrkörperbereich (204, 205, 207), wherein the fourth and fifth Absperrkörperbereich (206, 207) are mounted displaceably interlocking in a manner that the length of the shut-off (200) is variable and wherein the holding means (209) between the first and second Absperrkörperbereich (203, 204) is arranged such that in its rest position, the fourth and fifth Absperrkörperbereich (206, 207) overlap and the length of the Absperrkörpers (200) by a displacement the two Absperrkörperteile (201, 202) against the holding force of the holding means (209) can be reduced.

15. Control device according to claim 14, characterized in that the holding means (209) of the first control valve (21) for cooperation with the first and second Absperrkörperteil (201, 202) of the shut-off (200) comprises a compression spring, wherein the compression spring in a manner is designed so that the length of the shut-off body (200) in the rest position of the pressure spring by an on the valve control opening (219) facing the front outer surface of the first Absperrkörperteils (201) in the direction of the valve inlet (220) and / or one of the valve inlet ( 220) facing the front-side outer surface of the second Absperrkörperteils (202) in the direction of the valve control opening (219) each against the holding force of the compression spring acting force is reduced.

16. Control device according to claim 14 or 15, characterized in that the first control valve (21) with its valve inlet opening (220) in flow communication with the flow path (6) for directing the volume flow of the working fluid in the first direction, with its Ventilauslassöffnung (221) is provided with the flow path (6) for directing the volume flow of the working fluid in the second direction and with its valve control opening (219) with the flow path (6) for directing the volume flow of the working fluid in the first and in the second direction, wherein the flow connection between see the valve control port (219) and the flow path (6) in parallel Arranging a throttle element (611) for damping the flow rate of the working fluid from the valve control port (219), a check valve (612) for directing the working fluid to the valve control port (219), and a hydro-mechanical transmission means (615) for mechanically moving the shut-off body (200 ) at the valve control port (219), and wherein the valve control port (219) is further connected to the pilot control means (3) via the throttle member (611) so as to be enabled by the pilot control means (3) in the second position of its coupling means (33) Increasing the pressure in the working fluid at the valve control opening (219) via a movement of the shut-off (200) of the first control valve (21) from its open to its closed position causes a flow of the working fluid in the flow path (6) in the first direction.

17. A hydraulic drive system (16) for an elevator, comprising a reservoir (10) with a working fluid, a motor-driven pump (9), a hydraulic drive (11), a control device (1) and a flow path (6), in a manner between the reservoir (10), the control device (1) and the hydraulic drive (11) is provided that the working fluid from the reservoir (10) via the pump (9) and the control device (1) for hydraulic drive ( 11) and from this back via the control device (1) to the reservoir (10) can be guided, characterized in that the control device (1) is designed according to one of the preceding claims.

18. A method for retrofitting a hydraulic drive system (16) for an elevator according to the preamble of claim 17, comprising a control device (1) according to the preamble of claim 1, wherein the pilot control means (3) comprises a first and second pilot valve (31, 32). for controlling the respective first and second control valve (21, 22) and an electrical adjusting means (4) for actuating the first pilot valve (31) and a further electrical adjusting means for actuating the second pilot valve (32) characterized in that in a method step, a coupling means (33) having a coupling region (34) for coupling the first and second pilot valve (31, 32) is installed, wherein the coupling means (33) with a coupling region (34) for Hin- and moving between a first and a second position is formed, so that in the first position, the first and second pilot valve (31, 32) coupled by the coupling region (34) and by the electrical adjusting means (4) for allowing the volume flow of the working fluid means of the second control valve (22) are operable in the second direction in the flow path (6) and in the second position the first and second pilot valves (31, 32) are decoupled so that the first pilot valve (31) is actuated by the electrical actuating means (4 ) is operable to allow the volume flow of the working fluid through the first control valve (21) in the first direction in the flow path (6).