DE2308810A1 - CONTROL DEVICE FOR AUTOMATICALLY CONNECTING A VARIETY OF HYDRAULIC PUMPS TO FEED A VARIETY OF HYDRAULIC DEVICES - Google Patents

Description

Control device; To automatically switch on a large number of hydraulic pumps to feed a large number of hydraulic equipment

The invention relates to a control device for automatically switching on a large number of hydraulic pumps for the purpose of supplying pressure medium to a large number of hydraulic devices. The invention relates generally to hydraulic systems
Control devices for automatically controlling the sequence of actuation of a plurality of hydraulic pumps for supplying a pressure medium to one or more hydraulic pumps
Devices from a variety of hydraulic devices or cylinders.

309836/0465

Certain lifting or conveying machines, such as mobile, hydraulic cranes, use a boom with telescopic boom sections which adapt to the the respective work situation can be pushed apart or contracted. Usually each boom section is movable by means of its own hydraulic cylinder or hydraulic actuator, each such Actuator is operated with the help of its own control valve and all actuators via a single motor-driven one Pump can be supplied with hydraulic fluid. The control valves and actuators can be operated individually or at the same time will. For this reason, the pump must always be able to deliver the maximum amount of pressure medium that simultaneous actuation of all hydraulic devices is required. In practice, however, it has been found that the maximum pump output is rarely required, and that a not inconsiderable amount of energy is wasted when the pressure and volume of the pressure medium is continued must be kept at the level that is only necessary in the event of relatively infrequent peaks in demand.

The invention is therefore based on the object of a control device for the automatic connection of a large number of hydraulic pumps for the purpose of supplying pressure medium to a large number of To create hydraulic facilities that allow the System only the required amount of fluid at the required pressure.

According to the invention, this object is achieved by a control valve which, depending on the conditions of the Pressure medium flow to the hydraulic devices can be actuated in such a way that when operating only one hydraulic Device feeds only one pressure medium pump into the system, while operating several hydraulic devices

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feed several pressure medium pumps into the system.

The control device according to the invention can be used with particular advantage in mobile, hydraulic cranes and others Lever or conveying devices are used that have a telescopic Have boom, which contains various boom sections. These boom sections are independent movable from one another, around expanded or collapsed To take positions. Each boom section is with the help of its own hydraulic device, such as a hydraulic cylinder, movable. Each hydraulic cylinder or actuator is manually operated with the aid of one to be operated control valve in the extended or collapsed position, the control valve a neutral, a boom stretching and a boom pushing position. The various control valves are arranged in a common distributor and are fed via a common pressure medium source. the Pressure medium source contains a large number of pressure medium pumps, which is optionally connected to the release valve of the control valve a pressure-dependent valve can be connected, which in turn is responsive to the fluid pressure in each of the fluid lines between the control valves and actuators. Normally, only one pump is continuously connected to feed the pressure medium. However, there are several If the actuator is moved in the direction that extends the boom, there is a brief pressure increase in the feed lines to the actuators, which means that the pressure-dependent valve is set to several pumps to connect to the system to supply pressure fluid to the actuators.

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A machine equipped according to the invention, such as a portable hydraulic crane, has a telescopic boom, the two of which are independent of each other having movable boom sections. Each boom section is in the extended and collapsed positions movable, including separate hydraulic actuators or hydraulic devices that can be operated independently of one another to serve. Each actuator is operated using a hand-operated hydraulic control valve with three different Working positions actuated or controlled. A large number of Ilydraulic pumps are used to power the actuators intended. Furthermore, a control system is provided which contains a pressure-dependent valve with the aid of which one or more pumps to feed the hydraulic cylinders can be switched on automatically in the desired sequence The number of pumps depends on the number of cylinders that are operating at a given time are. The valve controlling the connection or the sequence responds to a pressure increase, which occurs when the feed lines to both actuators are simultaneously in the direction extending the boom are in operation. If only one of the actuators is operated in the direction that extends the boom, only a pump connected to its supply. If several actuators are operated in the direction that extends the boom, several pumps are automatically connected to the feed system through the pressure-dependent control valve.

An embodiment of the invention is shown in the drawing and is described in more detail below. Show it:

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Fig. 1 is a schematic section through a telescopic boom and through the Hydraulic actuator provided for him, containing a control device according to the Invention and

Figure 2 is a diagrammatic representation of a control system according to the invention in connection with the telescopic boom according to FIG. 1.

In Fig. 1, the reference numeral 10 is a collapsible Boom refers to the way it is used in cranes, excavators or other lifting or conveying equipment. The boom 10 includes a first section 12 made of steel tube with epden open on all sides and has a fastening member at its inner end 14, with which the boom is pivotally connected to a machine or attached to a machine can be. The boom 10 further includes a second section 16 made of steel tube with ends open on both sides, which can move telescopically within the first section 12. The boom 10 further includes a third Section 18 of steel tube, which is open at its inner end and extends within the second section 16 telescopically can move. On the section 18 is a tool or working member 20, such as an excavator shovel or a pulley, arranged. Although in Fig. 1 the boom 10 and its sections in substantially collapsed Position shown, it goes without saying that the sections 16 and 18 with the help of first and second hydraulic rams or actuators 22 and 24, respectively independently of one another from the shown, pushed together position into a completely pushed apart position Position and any intermediate positions are movable.

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Like the pig. 1 and 2, the actuator contains 22 a cylinder 26 which is fixedly attached to the first boom section 12 by means of a bolt 28, and a movable piston rod 30, which by means of a bolt 32 is firmly attached to the second boom section 16. The actuator 24 includes a cylinder 34, which means a bolt 36 fixed to the second boom section 16 is connected, and a movable piston rod 38, which by means of a bolt 40 fixed to the third boom section 18 is attached.

As FIG. 2 shows, the actuators 22 and 24 are supplied with a pressure medium from a pressure medium source in order to actuate them. This pressure medium source contains two conventional pressure medium pumps 42 and 44, the delivery rate on conventional Way is adjustable and which is driven with the aid of a conventional electric motor 46 at a constant speed will. The pressure medium passes through a pressure-dependent valve 48 and through a distributor used for control 50, a first control valve 52 and a second Contains control valve 54-.

The pumps 42 and 44 are connected to the pressure means inlets pressure-dependent valve 48 connected by means of pressure medium lines 56 and 58, respectively. The valve 48 operates in two Positions, with the aid of an internal loading spring 60 in a first position shown in FIG is moved to the left. According to the illustration in FIG. 2, the valve 48 is dependent on a change in the pressure medium pressure at its inlet 62 displaceable to the right in a second position. Does that depend on the pressure effective valve 48 in its first position, as shown in FIG. 2, it connects the pressure medium lines 56 and 58 with the pressure medium lines 64 and 68. The pressure

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Medium line 64 is with a reservoir 67 and the pressure medium line 68 is connected to the pressure medium inlet 70 of the distributor 50. The distributor 50 ″ has a pressure medium outlet 72, which is connected to a reservoir 76 via a pressure medium return line 74-. In practice you can the reservoirs 67 and 76 are connected to one another. Located If the valve 48 is in its second position, it connects the pressure medium lines 56 and 58 to the pressure medium supply line 68. In this way the control valves 52 and 54- pressure medium from a common pressure medium supply line 68 and supplied from a common pressure medium supply, either both pumps 42 and 44 or • Contains only one of these pumps, depending on the position of the valve .

The two control valves 52 and 54 are constructed in the same way and illustrate conventional three-position valves. Valve 52 includes first and second fluid outlets 78 and 80 and a manually movable control lever 82. The valve 54 also includes first and second pressure medium outlets 84 and 86 and a manually movable control lever 88. Both control levers 82 and 88 have a neutral position and are accordingly Pig. 2 from a neutral position to a position stretching the boom and movable upward from a neutral position to a boom contracting position, with a corresponding one Movement upwards or downwards a corresponding actuation of the stamp or actuation 22 and 24 as well the associated boom sections 16 and 18 result Has. The extent of the respective control lever adjustment in the one or the other direction determines the size of the pressure medium flow from the control valves 52 and 54 to the actuators 22 and 24. In this way, the amount of control lever movement controls the speed of movement of the piston rods 30 or 38 and the boom sections connected to them

20 9836 / € 4 * p

16 and 18.

The outlets 78 and 80 of the valve 52 are by means of Pressure medium lines 90 and 92 with openings 94 "and 96, respectively of the actuator 24 connected. That caused by the downward or upward movement of the control lever 82 of the control valve 52 to the openings 94 or 96 of the actuator 24 exerted pressure leads to an outward or inward movement of the piston rod 38 of the Actuator 24 and thus to a corresponding movement of the boom section 18. The outlets 84 and 86 of the valve 54 are with the help of pressure medium lines 98 and 100 is connected to openings 102 and 104 of actuator 22, respectively Is made by moving the control lever 88 of the control valve 54 in a downward or upward direction, respectively If pressure is exerted on the openings 102 or 104 of the actuator 22, this leads to an outward or inward direction directional movement of the piston rod 30 of the actuator 22 and thus to a corresponding movement of the boom section 16.

The lines 106 and 108 transmitting the pressure of the pressure medium are arranged between the pressure medium lines 98 and 90 and the pressure opening 62 of the pressure-dependent valve 48. It should be emphasized that the valve 48 is used to control the successive work or actuation processes of the respective stamp or actuator and thus the respective boom sections. Adjustable throttle valves or devices 110 and 112 are provided in lines 106 and 108 to balance the flow of pressure medium therein. A pressure increase in one of the lines 106 or 108, which was triggered by the pressure build-up in the lines 98 or 90 as a result of the actuation of one of the control valves 54 or 52, is

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23Q8810

not sufficient to move the valve 48, which controls the actuation sequence, from its first position shown in FIG to move. However, as a result of the actuation of both control valves 54 and 52, there is a simultaneous pressure increase in two lines 106 and 108 instead, the control valve 48 is caused to move into its second position, in the both pumps 42 and 44 are connected to line 68.

In the following, the operation of a machine will be described which has a telescopic boom 10, as shown in Fig. 1 and a control system for the hydraulic rams or actuators 22 and 24 as shown in FIG. owns;

It is assumed that the operating state in which the boom 10 is essentially pushed together Position according to FIG. 1 and in which the actuators 22 and 24 are shown in FIGS Take position. It is also assumed that the electric motor 46 and the pumps 42 and 44 are put into operation are that the valve 48 controlling the sequence has assumed its position shown in FIG. 2 and that the control levers 82 and 88 of the control valves 52 and 54, respectively in their neutral position, as shown in Fig. 2, are.

In this presupposed operating state, the pump 42 conveys pressure medium into the reservoir 67 and conveys the pump 44 pressure medium via the line 68 to the distributor 50. However, since both control valves 52 and 54 are in their neutral Position are located, the pressure medium delivered by the pump 44 is discharged via the line 74 into the reservoir 76. None of the actuators 22 or 24 is used for the purpose of

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pressure in one direction or the other and the pressure medium lines 90 and 98 are not available negative pressure. As a result, there is no pressure in lines 106 and 108 so that there is no movement of the control valve 48 are triggered from the first to the second position can. The boom 10 thus remains in its position shown in FIG. 1.

In the following it is assumed that, for example, one of the boom sections 16 or 18 are stretched target. If the section 18 is to be stretched, the control valve 52 is opened by the downward movement of its control lever 82 actuated from the neutral position to the pressure medium line 90 and the opening 94 of the actuator 24 below To put pressure. This has a stretching movement of the piston rod 38 and the boom section 18 at one speed result, which is determined by the extent of the downward movement of the control lever 82. In cylinder 34 The remaining pressure medium of the actuator 24 is transferred via the opening 96 and the line 92 to the opening 80 of the control valve 52 discharged and from there into the Manifold 50 and via line 74 to reservoir 76. Since the line 90 is under pressure, the line 108 and the opening 62 of the operating sequence controlling are available Valve 48 also under pressure. However, this pressure is not sufficient to cause valve 48 to move to cause the first to move to the second position. For this reason the system is only supplied with pressure medium via the pump 44 fed. If the control lever 82 of the control valve 52 is returned to its neutral position, no action is taken More pressure on the opening 9 ^ of the actuator 24 and the movement the piston rod 38 and the boom section 18 come to a standstill.

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If the boom section 18 is to be pushed back, the control lever 82 of the control valve 52 is removed from it neutral position up to the pressure medium line 92 and the opening 96 of the actuator 24 below To put pressure. This results in a pushing back movement of the piston rod 38 and the boom section 18 caused at a speed which is determined by the amount of upward movement of the control lever 82. Any remaining pressure medium remaining in the cylinder 34 of the actuator 24 is released via the opening 94 and the line 90 discharged to the opening 78 of the control valve 52 and arrives from there into the distributor 50 and over the line 74 into reservoir 76 * Such a flow through the conduit 19, however, applies negligible pressure on line 90 which is incapable of actuating the valve 48 to move.

The extension and retraction of the boom section 16 is carried out in the same manner as described above for section 18. The only exception is that the control lever 88 of the control valve 5 ^ is now actuated in order to put the actuator 22 and the boom section 16 into operation. It goes without saying that the pressure build-up in the pressure medium line 98 leads to a pressure build-up in the line 106, which, however, alone is not able to trigger the movement of the valve 48 from the first to the second position. For this reason, pressure medium is only supplied to the system via the pump 44 in this operating state. The pressure buildup in line 100 to cause an out-feed movement of the actuator 24 and the cantilever portion 16 leads to a pressure fluid flow from the opening 102 of the cylinder 26 54. This ^v pressure medium exerts on the mouth 84 of the control valve through the conduit 98 but too small a pressure of than that he had to move the valve

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could be enough.

In the following it is now assumed that both control valves 52 and 54 are operated simultaneously by their Control levers 82 and 88 are guided downward, causing an extension movement of the piston rods 38 and 30 of the actuator 24 and 22 and the boom section 18 and 16 triggered will. In such a case, both lines 90 and 98 are initially under pump 44 at the same time Pressure set. However, the pump 44 is not able to deliver a sufficient amount of pressure medium at a pressure which is required to simultaneously guide both actuators 22 and 24 in the stretching direction when one Load, such as the dead weight of the boom sections and any loads attached to them is. It should be noted, however, that the initial pressure in the two lines 106 and 108 is sufficiently high is to pressurize the opening 62 of the valve 48 controlling the sequence and thus to cause the valve, to move from the first position shown in Fig. 2 to its second position in which there are both Pumps 42 and 44 connects to the feed line 68 to supply pressure medium to the system. That of both pumps 42 and 44 conveyed pressure medium is mixed in the distributor 50 and made available to the two actuators with a suitable pressure and in sufficient quantity. As soon as however both control levers 82 and 88 or one of these two control levers of the control valves 52 and 54 in the neutral position returned or guided into the position pushing the boom together, the pressure of the pressure medium drops at the opening 62 of the valve 48 is sufficient to close the valve 48 shows the return from the second position (in which both pumps 42 and 44 are connected to the system) in

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to allow the first position (in which the system is only fed by the pump 44).

If the device according to the invention is used, for example, in connection with a mobile, hydraulic hoist , a telescopic boom 10 with the sections 16 and 18 is provided on this hoist or crane, which can be pushed apart or contracted independently of one another, including hydraulic actuators 22 and 24 to serve. The actuators 22 and 24 are operated or controlled with the aid of the three-position operable valves 54 and 52, which are provided with control levers 88 and 82, respectively, which move from a neutral position to a position in which the boom is extended or the boom is pushed together let move. The control valves 52 and can be connected either to a pump 44 or to two pumps 14 and 42, which feed pressure medium into the system with the aid of a pressure-dependent valve 48 which is effective in two different positions. The control valve 52 is connected to the actuator 24 of the boom section 18 via the pressure medium lines 90 and 92. The control valve 54 is connected to the actuator 22 of the boom section 16 via the pressure medium lines 98 and 100. The pressure medium line 90 is connected to the pressure opening 62 of the valve 48 via a pressure medium pressure line 108. The pressure medium line 98 is also connected to the pressure opening 62 of the valve 48 via pressure medium pressure line 106. If only one of the valves 52 or 5 is actuated in order to operate the associated actuators 24 or 22 with the aim of bringing the boom section 16 or 18 into the extended position, either the pressure medium line 90 or the pressure medium line 98 is below Pressure. However, the pressure build-up in either of the lines 90 or 98 is not sufficient to cause the valve 48 to move from the first position in which the pump 44 controls the system

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feeds to induce. However, if both control valves 52 and 54 are operated simultaneously in the manner that one
Causes elongation of the boom, so both pressure medium lines 90 and 98 are under pressure at the same time, what
leads to the fact that there is sufficient pressure at the opening 62 of the valve 48 to switch the valve into a second
To transfer position in which both pumps 42 and 44 for feeding the system are connected to the system.
The build-up of pressure in one or both of actuators 22 and 24 to release the boom collapsing
Movement does not move valve 48 from the first to the second position.

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Claims (12)

Claims '1 ") Control device for automatically switching on a large number of hydraulic devices for the purpose of supplying pressure medium to a large number of hydraulic devices, characterized by a control valve (48) which can be actuated depending on the conditions of the pressure medium flow to the hydraulic devices (22, 24) in such a way that when only one hydraulic device is operated, only one pressure medium pump (44) feeds into the system, while when several hydraulic devices are operated, several pressure medium pumps (42 i 44) feed into the system. 2. Device according to claim 1, characterized in that for operating each actuator (22, 24) a control valve (54, 52) is provided is. 3. Device according to claim 1 or 2, characterized in that the plurality of pumps (42, 44) form a common pressure medium source for the control valves (54, 52). 4. Device according to at least one of claims 1 to 3, characterized in that each Actuator (22, 24) can be operated in two directions and that the control valve (48) is dependent on the conditions of the pressure medium flow, which are based on the actuation of the actuator in one of the two directions based, is operable. 309836/0465 5. Device according to one of claims 1 to 4, characterized in that the control valve (48) is pressure-dependent and can be actuated in such a way that more than one pump is connected to the system is, if more than one actuator to perform a movement in one direction below Pressure is set. 6. Machine set-up with one in a variety of movable boom sections subdivided telescopic boom, characterized in that that for moving each boom section (16, 18) an independently operated hydraulic Actuator (22, 24) is provided that each actuator (22, 24) is assigned a control valve (54, 52) that a plurality of pumps (42, 44) for feeding pressure medium into the actuators (22, 24) via the control valves (54-1 52) is provided, and that a control valve (48) is provided, which can be actuated in this way as a function of the conditions of the pressure medium flow is that when only one actuator is operated, only one pump (44) is connected to the system, while when operating more than one actuator, more than one pressure medium pump is connected to the system is. 7. Machine device according to claim 6, characterized in that each movable boom section (16, 18) is movable in extended and extended positions that each actuator (22, 24) stretching into the boom and contracting the boom Directions is movable and that the control valve (48) in. Depending on the conditions of the pressure medium flow can be actuated, which is based on the operation of the actuator (22, 24) in the boom stretching direction are based. 309836/0465 8. Machine device according to at least one of the claims 6 and 7 »characterized in that the control valve (48) is pressure-dependent and is operable such that more than one pressure medium pump is connected to the system, if more than an actuator is pressurized to effect movement in the direction extending the boom. 9. Machine set-up with a variety of self-employed actuatable hydraulic actuators, each actuator being movable in two directions, characterized by a plurality of control valves (52, 54), a control valve (54, 52) being assigned to each actuator (22, 24), a plurality of pumps (42, 44) for feeding pressure medium into an actuator (22, 24) each via a control valve (54, 52) and by a pressure-dependent control valve (48), which depending on the pressure of the pressure medium flow to the actuators (22, 24) can be actuated in such a way that only a pressure medium pump (44) is connected to the pressure medium feed system, if only one Actuator moves in one direction and that more than one pressure medium pump is connected to the feed system is when several actuators move in one direction, the pressure of the fluid flow from the Operate the actuator (22, 24) in one direction is dependent. 10. Machine device according to claim 9 »characterized in that the control valves (54, 52) are fed with pressure medium via the control valve (48) together via the pumps (42, 44). 309836/0465 11. Machine device according to claim 10, characterized in that between each of the Control valves (54- »52) and the associated actuators (22, 24) a pressure medium feed line (98, 90) for operating the respective actuator in one direction is provided and that between each of the feed lines (98, 90) and a pressure port (62) in the control valve (48) a pressure medium pressure line (106, 108) is provided in each case. 12. Machine device according to claim 11, characterized in that in each pressure line (106, 108) an adjustable throttle device (110, 112) is provided. 13 · Machine device according to claim 12, characterized in that a telescopic boom (10) is provided, which has a variety of movable Boom sections (16, 18) contains that / each of these boom sections (16, 18) with the aid of a the actuator (22, 24) can be moved into stretched and collapsed positions and that one direction of movement an actuator (22, 24) the movement of the boom section (16, 18) assigned to it into the Boom (10) has a stretching direction. 309836/0465