WO2015071446A1

WO2015071446A1 - Air control for a suction head

Info

Publication number: WO2015071446A1
Application number: PCT/EP2014/074698
Authority: WO
Inventors: Michael Rössler; Franz Vogel
Original assignee: manroland sheetfed GmbH
Priority date: 2013-11-16
Filing date: 2014-11-16
Publication date: 2015-05-21
Also published as: CN105705445A; DE102014116728A1; EP3068714A1; CN105705445B

Abstract

The purpose of the invention is to improve a device for air control in blow air consumers and suction air consumers of sheet-processing machines. To this end, a device for ventilating suction air consumers is connected in the area between an ejector and the suction air consumer. The device comprises solenoid valves for supplying the ejector with blow air.

Description

Air control for a suction head The invention relates to a device according to the preamble of claim 1.

In the context of sheet-processing machines, such as on sheet-fed rotary printing presses, it is known to supply sheet-shaped substrates, such as printing material sheet B, synchronously in synchronism with the sheet in a sheet-fed stream. In the process, the printing material sheets B are separated from a stack of sheets and fed to the machine with exact timing in the working cycle of the machine.

It is known to use a suction head for singulation on a sheet feeder. The suction head separates by means of suckers the uppermost printing material B of the sheet stack and promotes this to a transfer unit, which is often designed as a belt table so that it can be passed by means of this machine to the sheet processing. The suction cups are used as separating suction cups for separating lifting of the printing material sheets B and

Towing sucker for the raised conveying the printing material B formed.

The suckers are driven by corresponding drive mechanisms in a sequence corresponding to the clockwise movement, wherein the separating suckers execute an up-and-down movement oriented essentially vertically to the surface of the sheet stack and wherein the drag suckers have an aligned substantially parallel to the surface of the sheet stack. and to carry out the movement.

In a predetermined but adjustable relation to the respective suction movement, an adapted control of the suction air necessary for the detection of the printing material sheet is furthermore provided on the suckers. ,

The air supply can be done by means of mechanically driven valves. Furthermore, it is known that the air supply of the suction head via valves by means of Ejek- control door systems. Furthermore, the air supply via individually controlled valves for each consumer (sucker) can be made.

For this purpose, an air control and / or air control device is known from EP 1 020 388 B1. This is used on sheet feeders and is provided with an air pressure source which generates an overpressure on a nozzle and thus supplies an ejector to the beat of a sheet-processing machine. As a result, a negative pressure is generated by means of the blowing air at the ejector, which is led to a negative pressure consumer. A switchable shut-off valve serves to adjust the timing of the connection and connection of the vacuum consumers within a work cycle in response to production data in the cycle of the sheet-processing machine.

From EP 1 398 285 B1 a further air control and / or Luftregelungsein- device of the same kind is known in which a radial port of the ejector is connected to the outside air and the outlet of the ejector leads to a Blasluftverbraucher. Furthermore, it is provided there to arrange an adjustable throttle element between the air pressure source of the ejector and the ejector, which adjusts the flow rate flowing through in dependence on production data. The radial connection of the ejector is connected to the outside air and the outlet of the ejector leads to a Blasluftverbraucher.

Furthermore, EP 0 775 655 B1 discloses a suction and / or blown air control. This serves to supply the consumers of a feed device for sheets to a sheet-processing machine. A connection of the consumer is acted upon by the negative pressure of a vacuum source and the outlet of the consumer is directly connected to an outlet of an electrically controllable valve. A control device controls the valve in such a way that the consumer sucker is controlled depending on parameters of the rotation angle and the clock of the sheet-processing machine. The electrically controllable valve has for this purpose two switching positions, in their positions, the connection and disconnection of the suction air are made functionally. Finally, DE 10 2012 103 772 A1 discloses a device for supplying a vacuum consumer of a sheet-processing machine in a working cycle of the sheet-processing machine with negative pressure. In this case, a first valve arranged between an air pressure source and an ejector can be opened and closed by a control unit during each working cycle, wherein the inlet of the ejector is subjected to a positive pressure air flow and flows through the ejector to an outlet leading to the atmosphere. In this case, a negative pressure consumer is coupled between the inlet and the outlet of the ejector via a suction line. Since the sheet-processing machine is operable with different clock cycles per unit time are stored in a memory according to several different opening times and each associated closing times of the first valve depending on several different numbers of working clocks per unit time. The control unit opens the first valve accordingly depending on the respective power stroke per unit time at the associated opening time and closes it at the associated closing time.

Furthermore, DE 1 2007 001 617 T5 discloses methods and means by which a pressure different from ambient pressure is generated and fed to a sheet feeding printing press to effect or control the transport of sheets through the printing press. A pressure other than atmospheric pressure is formed and fed to a paper sheet in a sheet feeding printing machine. The working pressure is generated in a means arranged to supply the working pressure to the sheet to thereby effect or control the transport of the sheet in the printing press. A drive pressure is delivered to a high pressure ejector, thereby determining the working pressure delivered by the ejector. The driving pressure supplied to the ejector is adjusted in response to a comparison between the detected working pressure and a predetermined working pressure to achieve continuous adjustment of the working pressure to a respective sheet. From DE 10 201 1 1 18 168 A1 a method for operating a vacuum gripper, vacuum control device and a manipulator are known. The vacuum gripping device has a vacuum gripper, a processing device, a sensor device for providing a fluid and / or vacuum-related sensor signal and a fluid control valve which can be controlled by the processing device for a vacuum on the vacuum gripper. For processing the sensor signal and for activating the fluid control valve, a control signal is output from the processing device to the fluid control valve at a control time, determination of an action time at which a change of the sensor signal has occurred by a predeterminable amount of change, and calculation of a correction value based on a temporal time Difference between the activation time and the time of action and correction of activation time or activation duration of the fluid control valve. DE 10 2012 209 578 A1 discloses a method for supplying compressed air to a printing press, a compressed air supply for a printing press and the use of a low-pressure valve controlled by two proportional valves for supplying compressed air in a printing machine. In order to improve the compressed air supply of a printing press, these valves are placed in a first open position and opened or closed with a time delay to mitigate sudden pressure changes in the central supply line by switching operations on the valves. The compressed air is gradually discharged from the central supply line via the valves during blown air operation or, in the case of suction air operation, is gradually fed to the central supply line in such a way that the pressure changes are compensated by the control device of the compressed air generator.

The air supply is not secure enough in such systems due to line losses and extended pressure reduction with extremely fast switching times and short switching cycles and despite the most accurate adjustment controls. It is therefore an object of the invention to improve devices for air supply of the type described above so that a secure air supply can be made possible. The solution of the invention is designed according to the features of patent claim 1.

An apparatus for air control of air consumers is provided in the area of a sheet feeder of a sheet-processing machine. The sheet feeder has a suction head, wherein the suction head is provided with working members for separation or separation, for removal and for conveyance of printing material from the top of a stack of sheets in the sheet feeder. To produce air, one or more ejectors are provided, which are provided with a compressed air connection and which are connected to the working organs of the suction head via air lines.

According to the invention, a solenoid valve is associated with the compressed air connection of an ejector, which is designed for timed compressed air supply to the ejector via a blast air line. The ejector is connected to one or more work organizers. In the line connection between the ejector and the / the work organs, an air control device is provided, which is operated in time with the sheet-processing machine.

Advantageously, a device for ventilation of Saugluftverbrauchern in the area between an ejector and the / the work organs is connected. The / the work organs are connected via a suction air line with an air connection of the ejector for suction. The device is controllably arranged as a bypass with a blown air line from a first solenoid valve to the blown air supply of the ejector to a suction air line between the ejector and the / the work organs. Advantageously, the device is arranged independently of the first solenoid valve controllable as a blown air line from a second solenoid valve to the suction air line between the ejector and the / the work organs. Advantageously, the device is formed by the first solenoid valve, wherein the solenoid valve is designed controllable such that the Blasluftleitung for connection of the solenoid valve with the ejector selectively in communication with the compressed air connection or in a connection with the Blasluftleitung, which is used to connect the solenoid valve the suction air line between the ejector and the / the working organs used, is switchable.

Advantageously, the / the work organs are connected via at least one Blasluftleitung with an air connection of the ejector for blowing air. Advantageously, the / the work organs are designed as blowing devices, wherein, the ejector for the generation of suction air and for the production of air blast with low pressure and increased volume is used. The air emerging from the ejector is throttled in pressure and enriched in volume with the air supplied via the air connection.

The supply of blown air to the / the work organs is advantageously carried out via an air control device directly behind the outlet from the ejector.

Advantageously, when required by different qualities of blowing air, such as when separating and carrying in the sheet separation two air generating devices each provided with a compressed air connection, one solenoid valve, one blown air line, one ejector and one blown air line to the / the work organs, wherein the solenoid valves are controllably arranged so that from one of the air generating means first a Blasluftstrom higher pressure and lower volume can be discharged and that thereafter by the air generating means a Blasluftstrom lower pressure and higher volume can be dispensed, and that the different blast air streams are the same work organs fed successively.

Advantageously, the air generating devices are designed to supply the different air streams to the same work organ or specifically to different work organs.

Advantageously, at least one common control is assigned to the solenoid valve (s) in such a way that a temporally controlled supply of compressed air to the or each ejector synchronized with the working cycle of the sheet-processing machine can be carried out.

Advantageously, an air control device is arranged in a line connection between the ejector (s) and the working members, by means of which the air flows generated in the air generating devices can be controlled in the working cycle and in the time duration.

The air control device is advantageously designed as a control roller which has connections for suction air and / or blown air and has a valve roller which can be driven drivable in the machine cycle and has passages for suction air and / or blown air.

Advantageously, the suction head is provided with air generating means with solenoid valves and ejectors for generating suction air and blown air, wherein the air generating means are each connected to respective working organs of the suction head via air ducts.

A device is provided for ventilating the suction cups, which are subjected to negative pressure, because the suction air is not quickly dissipated quickly from the residual pressure upstream of the ejector. The device is designed as a bypass with a fast-acting solenoid valve on a suction line between the ejector and the sucker. In this case, a device according to EP 1 398 285 B1 can be used as the ejector for generating blast air with low pressure and increased volume. Exiting air from the ejector is throttled in pressure and enriched in volume with the air supplied via the suction point. This air can therefore be used for winds in the Vorlockerung and sheet separation. The control of this blowing air takes place optimally behind the ejector.

Since the suction air generation at short work cycles of the suckers, as in very fast-running sheet-fed presses, the compressed air supply via solenoid valves in the ejector too sluggish and thus, for. For the suction movement over a pulsed suction air with ejectors is too slow, also remedy must be created here. Therefore, it is provided here to provide a continuous operation of the compressed air supply to the ejector and then make a control of the suction air via a mechanical control or a control roller behind the ejector.

Furthermore, there is a need for two different qualities of blowing air when separating and carrying printing material sheet B for sheet separation. In current embodiments, the corresponding air supply is passed over a control roller, wherein a channel constriction can be used. When using solenoid valves, no air flow regulation in stages is possible. Therefore, in this case, two air generators are used, which are preferably provided with a respectively conventionally generated characteristic. Furthermore, both air generators can open into the same fan or Blasluftverbraucher.

Finally, it is proposed to apply in an advantageous supplement, a blast air supply with tempered local air, for example, for special substrate materials such as very thin papers at low pressure. Therefore, the invention is advantageously possible both for the control of the suction air supply of Saugluftverbrauchern and for the supply of Blasluftverbrauchern with blown air of different quality. In drawings, embodiments of the invention are shown. Show

FIG. 1 shows a first embodiment according to the invention,

FIG. 2 shows a simplified embodiment of the first embodiment according to FIG. 1 according to the invention,

FIG. 3 shows a second embodiment according to the invention,

Figure 4 shows a third embodiment of the invention and

Figure 5 shows a fourth embodiment of the invention.

In Figure 1, an arrangement for the suction air supply to a suction head 1 is shown symbolized. The suction head 1 is provided as part of a sheet-processing machine and can in this case be used, for example, in a sheet-fed printing press for the sheet separation of the printing material sheet B from a stack of sheets in a sheet feeder. For this purpose, the suction head 1 is operated with different types of workpieces 2, such as suckers for separating and transporting, in the working cycle of the sheet-processing machine, so that separated from a sheet stack stacks of printing material B from the suction head 1 can be transferred to the sheet processing machine for further processing , Working members 2, which are formed as suckers, have a housing in which a piston can move up and down to raise the sucker from a waiting position after taking a printing material B under the action of the negative pressure of the suction air in a working position.

The suction head 1 here are various working members 2 associated with movable, which may be designed differently than suction organs or as blowing organs trained. Preferably, the working members 2 are designed as separating or lifting suction or as tow or transport suction. The working members 2 are further arranged connected via different gear trainings with the suction head 1. The suction head 1 is further assigned, for the purpose of supplying air to the working members 2, with at least one suction-air generating system having at least one ejector 3, which is connected to one, several or all of the above-mentioned working members 2.

The ejector 3 is operated for suction air supply according to the principle of a suction jet pump with compressed air, wherein the compressed air is passed through a nozzle at the narrowest point of an air connection is arranged.

Whenever compressed air is used below, compressed air in the form of blown air is always meant.

Compressed air is first supplied to the ejector 3 at a first air connection 3.1 under control of a first solenoid valve 4 in the delivery mode by a first compressed air line 5. The solenoid valve 4 is connected to a well-known compressed air supply 7. This can be coupled to a compressed air network in the sheet-processing machine operating operation. It may also be provided a special compressed air supply with an independent compressed air generator for ejectors.

The ejector 3 is connected to a second air connection 3.2 via a suction air line 6 with the suction head 1 or one or more of its working members 2, which are then formed as suction organs. In known manner, a suction air line 6 is connected to the ejector 3 in the region of a constriction, which is traversed by the compressed air. Due to the accelerated flow of compressed air in the constriction 6 air is sucked from the suction air line and in this way via the suction air line 6 in the working member 2, which is arranged at the end of Saugluftleitung 6 as Saugluftverbraucher, generates a negative pressure and thus in the working member 2, a suction air flow , which acts on its outboard work surface. For discharging the compressed air used in generating the suction air at the / the work organs 2 or the / the consumers in the ejector 3, an air outlet 13 is disposed on a third air connection 3.3 to the ejector 3, which provided with a sound attenuation element and / or also with a Valve can be controlled. Thus, the compressed air at the air outlet 13 is pressure-reduced and enriched in volume around the air drawn in by the consumer (s) as a sound-insulated and possibly controlled blowing jet.

The first solenoid valve 4 is further connected via a second Blasluftleitung 8 with the suction air line 6 by this opens in the region between the ejector 3 and the suction head 1 at a line branch 9 in the suction air line 6. The second blast air line 8 leads the suction head 1 in this way a first controlled flow of blowing air in the region of the suction air line 6 to. It should be noted that when switching the solenoid valve 4 for supplying compressed air via the compressed air line 8 in the suction air line 6 at the same time the air access to the solenoid valve 4 to the compressed air line 5 between the solenoid valve 4 and ejector 3 is blocked.

Therefore, in this case, in the compressed air line 5, a residual amount of compressed air is included, which can be reduced only via the ejector 3 with simultaneous generation of suction air in the suction air line 6. This overrun of suction air is therefore degraded under the control of the solenoid valve 4 via the compressed air line 8. It is possible in the simplest way to prevent the trailing suction can still reach up to the / the work organs 2 or the / the consumers.

Furthermore, the suction head 1 can be additionally supplied via a second supplied with compressed air solenoid valve 10, a further controlled flow of blowing air. For this purpose, the second solenoid valve 10 is connected via a third blown air line 1 1 to the line branch 9 in the suction air line 6 in the region between the ejector 3 and the working element 2 or the consumer in the suction head 1. The two solenoid valves 4 and 10 are common by means of a valve control 12 and independently operable. In this case, the valve control is coupled to a control computer to which a rotation angle signal is fed to the sheet-processing machine. As a result, the compressed air supply to the ejector 1 via the control of the solenoid valves 4, 10 in response to the rotation angle signal and thus from the power stroke of the sheet processing machine done.

During operation, by means of the first solenoid valve 4, a specifically set blown air supply for / the suction air consumer 2 is made in the cycle of the machine processing the sheets. As a result, the suction head 1, in line with the sheet-processing machine, can, for example, separate the printing material sheet B from a stack of sheets in a sheet feeder and convey it to the sheet-processing machine. The ejector 3 is supplied with a compressed-air pulse controlled by the solenoid valve 4, so that at the correct time and for the correct period of time through the suction air line 6 to the working members 2 of the suction head 1 a respective required negative pressure is applied, by means of which a printing material sheet is detected B can be done via, for example, one or more suckers.

In a corresponding time offset to the supply of compressed air is interrupted by the solenoid valve 4, so that the negative pressure in the suction air 6 and on the / the Saugluftverbrauchern or working organs 2 collapses and the detected substrate sheet B from, for example, designed as a sucker working organ 2 for the other Processing can be released.

To ensure that the negative pressure on the working member 2 actually degraded in good time and the printing material B is thus actually released, the second blown air line 8 designed as a compressed air bypass is charged with a compressed air pulse at the first solenoid valve 4. In this way, at a time during which the air pressure in the first compressed air line 5 is still reduced to the ejector 3, in the thus still continuing negative pressure phase between the ejector 3 and the / the working organs 2 of the suction head 1, a pressure equalization geschaf- fen, Thus, the conveyed printing material B can be detected and released in a timely manner.

To improve the working parameters of such a suction head 1 even at very high operating speeds and associated very short work cycles, the supply of compressed air into the suction air line 6 is provided by the second solenoid valve 10 independently of the first solenoid valve 4. In this way, via the third blown air line 11, a specifically controlled compressed air flow for interrupting the negative pressure on the working device 2 or the consumer (s) can be used even earlier and more accurately.

The effects of the compressed air streams emitted by the first and second solenoid valves 4, 10 can be combined with each other and adjusted to one another in order to achieve a maximum delivery rate for the suction head 1.

The control of the suction air flow can be done in a suction head 1 in addition to an air control device 22 in the form of a known control roller. This is switched on in Saugluftweg the Saugluftleitung 6 between the / the work organs 2 and consumers. A control roller is a rotating valve member which is driven synchronously with the machine and releases or closes air passages via control openings in relation to the machine rotation angle. With the control roller a predetermined by the mechanically fixed valve design air supply is possible. By means of a control roller, combined air feeds for blowing air and suction air are also realized, so that all the consumption of a suction head 1 can be centrally controlled.

In the case of the assignment of a control roller, the suction and / or blown air generation is used by means of one or more ejectors 3 for the timely, localized and consumption of compressed air temperature of the consumption air.

The blown air lines 8, 1 1 for reducing the negative pressure at the / the Arbeitsorga- NEN 2 can be connected before or after the air control device 22 with the suction air line 6. FIG. 2 shows symbolically an arrangement for the suction air supply essentially corresponding to FIG. 1, wherein a printing material sheet B is to be detected by a working member 2, which is designed as a suction device. The suction head 1 is in turn assigned a suction air generating system with an ejector 3. The ejector 3 is connected via a first solenoid valve 4 with a compressed air supply 7. From the compressed air supply 7, the ejector 3 is supplied with compressed air, which is supplied via the solenoid valve 4 as a controlled blowing air flow via a first compressed air line 5. On the other hand, the ejector 3 is connected via a suction air line 6 to one or more working members 2, which may be designed as suckers. In the ejector 3, in turn, by means of the pending compressed air, the suction air line 6 connected to an air connection 3.2 is supplied with suction air by accelerated flow and a negative pressure is produced in the work organ 2 or consumers.

The first solenoid valve 4 is further connected via a second Blasluftleitung 8 with the suction air line 6 by this opens in the area between the ejector 3 and the / the work organs 2 of the suction head 1 at a manifold 9 in the suction air line 6. The second blown air line 8 can therefore supply the suction head 1 with a stream of blown air into the suction air area in this way.

During operation, a targeted compressed air supply to the ejector 3 is made in the cycle of the sheet-processing machine by means of the first solenoid valve 4. For this purpose, the magnetic valve 4 is designed such that a circuit can be carried out in which a blown air connection 4.1 to the compressed air supply 7 is connected to a blown air outlet 4.2 to the blown air line 5. The Blasluftausgang 4.2 is then coupled via the Blasluftleitung 5 with the ejector 3 and passes this to the controlled compressed air flow. As a result, the suction head 1 can be controlled via the ejector 3 in the cycle of the sheet-processing machine to separate the printing material sheet B from a stack of sheets in the sheet feeder and convey it to the sheet-processing machine. Here, the ejector 3 is supplied in each case a blown air, so that at the right time on the suction air line 6 on the suction head 1 in the / the work organs 2 a negative pressure applied by means of which detecting, separating (separating) and / or conveying each sheet of printing material B means one or more working elements 2 designed as a suction device can take place.

In a predetermined time offset to the supply of compressed air to the ejector 3 is interrupted by the first solenoid valve 4 at the end of a separation and / or delivery cycle. In order to release the printing material B for further promotion, the negative pressure at the / the work organs 2 in the suction head 1 must be interrupted. So that the negative pressure at the / the work organs 2 collapses in time and the recorded substrate sheet B can be released by the / the work organs 2 for further processing, to ensure that the negative pressure on the / the work organs 2 is actually released in good time and degraded as much as possible.

For this purpose, the second blown air line 8 designed as a blown air bypass is connected directly to the blown air line 5 at the first solenoid valve 4, which leads to the ejector 3. By switching the solenoid valve 4 still stored under pressure air is introduced into the Blasluftleitung 8 as Blasluftimpuls in this line section of the blast line 5 before the ejector. In this way, at the same time, during which the blown air pressure in the first Blasluftleitung 5 is still degraded to the ejector 3, created in the thus continuing vacuum phase between the ejector 3 and the working member 2 of the suction head 1, a pressure compensation. For this reason, the pressurized air in the blast air duct 5 in the ejector 3 can not continue to produce suction air at the suction air outlet 3.2. In addition, the remaining in the first Blasluftleitung 5 under pressure air volume is introduced through the second Blasluftleitung 8 via the branch line 9 in the suction air line 6 and there is rapidly reducing the upcoming vacuum. This means that the conveyed substrate sheets B can be recorded and released in real time. Also in this embodiment, the ejector 3 on the side of the Blasluftaustritts the air outlet 13 in the Blasluftleitung 6 downstream of an air control device 22 may be arranged by means of which the exiting suction air flow in the cycle of the sheet-processing machine is controllable.

The blown air line 8 for reducing the negative pressure at the / the work organs 2 can be connected to the suction air line 6 before or after the air control device 22.

FIG. 3 shows the use of blowing air present at an outlet of an ejector 30. The ejector 30 is supplied as described previously to Figure 1 with compressed air and generated by the air suction a negative pressure, which can be used optionally on working organs 2 and consumers for sucking and transporting printing material sheet B.

In this case, at an air outlet 13 of the ejector 30, in addition to the compressed air supplied via a solenoid valve 40, airflow sucked in by the ejector 30 at a suction air inlet 3.2 and possibly by the working member 2 or the consumer (s) is blown off. Thus, there is a combined blast air flow, which exits at the air outlet 13 of the ejector 30. This combined blast air flow at the air outlet 13 is characterized, on the one hand, by a pressure which has been reduced after the ejector passage and, on the other hand, by an enlarged volume around the intake air volume.

This combined blast air flow is tempered by the arrangement of the suction effect of the sucked in the region of the suction head 1 air content in relation to the local environment conditions. Therefore, the blast air flow exiting the air outlet 13 of the ejector 30 is best suited for use in sheet separation on a suction head 1. This effect is due to the fact that the blast air flow largely has the properties of the ambient air in the vicinity of the sheet stack in the sheet feeder of the sheet-processing machine and thus does not have too great differences in temperature and humidity relative to the printing material sheet B to be processed. In order to use this blown air stream, a specific embodiment is shown here. In this case, downstream of the ejector 30 on the side of the blown air outlet, the air outlet 13 is arranged in a blown air line 23, by means of which the outgoing blown air flow can be controlled again in time with the sheet-processing machine.

The air control device 22 may also be designed in the manner of a control roller. A control roller is designed as a mechanical with the cycle of the sheet-processing machine driven valve control.

The blast air control can also be carried out without an air control device 22 and is then controlled based on the machine cycle only by the control by means of the solenoid valve 40.

The controlled blowing air flow can be additionally regulated in its volume and pressure. The tempered, as well as in the power stroke and possibly according to its pressure and volume controlled Blasluftstrom is then separately or combined supplied to one or more work organs 24, which are arranged as Blasluftverbraucher the suction head 1 in the area of Bgentrennung at the top of the sheet stack in the sheet feeder ,

The blast air flow is directed to areas of the side edges S of the sheet stack and serves to fanned the top sheet B of the sheet pile. These can be separated easier and safer from each other. Furthermore, the blast air flow can also be conducted under a printing material sheet B already separated from the upper side of the sheet stack so that it is provided with a carrying air cushion opposite the upper side of the sheet stack and can thus be reliably transported away in the direction of the sheet-processing machine.

In this case, the blast air flow can also be supplied in differentiated physical quality (pressure, temperature, volume) and at different times in one or more different working cycles to the same working member 24 or blast air consumers for different effects in sheet separation and during sheet transport. By way of example, a short blown air blast at elevated pressure can be used as a so-called separation air to pre-loosen the uppermost sheet of printing material B resting on the stack of sheets on a working member 24 acting as a blowing device in a first cycle section. For this purpose, a further improvement of the air supply is shown in FIG.

Both operating modes on a working member 24 or blast air consumers or with two working members 24 or specific Blasluftverbrauchern be carried out with the tempered air from the place of processing, so that the sheet processing particularly gentle and beneficial for all materials to be processed the printing material B can be done.

FIG. 4 schematically shows a combined device according to FIGS. 2 and 3. Here, a suction head 1 is shown both with working organs 2 in the form of suction devices as well as working organs 24 in the form of blowing devices. Here, a working member 2, which is designed as a suction device, an ejector 3 in the manner described above for Sauglufterzeugung with the involvement of a solenoid valve 4 and an ejector 3 assigned. Furthermore, a plurality of working members 24, which are designed as blowing devices, an ejector 3 in the manner described above for blowing air generation with the involvement of a solenoid valve 4 and an ejector 3 assigned.

In a manner already described, a separate air supply via an ejector 3 may be assigned to each of the working members 2, 24 shown, differing from this illustration. Likewise, a common air supply via an ejector 3 can also be assigned to different working organs 2 for suction air processing.

In Figure 4, a common control 12 is provided for all air supply systems in conjunction with solenoid valves 4.

It should be noted here, however, that at least one separate solenoid valve 4 is required for independent control of the respective air production at least for the generation of suction air on the one hand and on the other hand for the production of air. Furthermore, the air control device 22 provided for the blown air generation in FIG. 4 can be designed as a control roller driven in the machine cycle, as already explained.

In a further embodiment, however, may also be provided as an air control device 22 for both the control of the supply of suction air to the / the work organs 2 and the supply of blowing air to the / the work organs 24 suitable common control roller. This then takes on the of the suction air ducts 6 and the supplied from the Blasluftleitungen 23 working air in separate channels and directs them controlled to the working organs 2, 24 at the right time and in the right time each

Furthermore, the control roller can be omitted and their function can be replaced solely by the control of the solenoid valves 4.

With regard to FIG. 4, as well as the relationship of the embodiments according to FIGS. 1 and 2 with respect to FIG. 3, it should be noted that an interruption of the blast air flow to the working members 24 is not provided. This applies because both the function of sheet loosening from the side edge of the sheet stack and the generation of air or Tragluftpolsters under a raised printing material B is not time-critical in such a way as the separation and promotion of printing material B. The separation and promotion On the other hand, the printing material sheet B must be exactly in the machine cycle.

FIG. 5 diagrammatically shows a device according to FIG. 3 for improved blast air control. Here, on the same working as a blowing device working member 24 in a second section of a cycle another blown air lower pressure and increased volume for transporting conveying the printing material B as so-called carrying air for generating a Tragluftpolsters under a lifted from the surface of the sheet stack printing material B provided become.

For this purpose, an air generating device for blowing air is provided according to Figure 3, in which by means of a solenoid valve 4 by a blast air duct 5, an ejector 3 is acted upon with compressed air. By connecting a blast air line 23 at the air outlet lass 13 of the ejector 3, the air stream discharged there is fed to one or more working members 24. These working members 24 are designed as so-called carrying air blowers, in order to blow air from the stack side edge S forth under a separated and at its trailing edge lifted by suckers Bedruckstoffbo- gene B.

In this case, the effect must be taken into account that a printing material sheet can have an extension of more than 0.75 square meters and therefore the carrying air first requires a certain amount of energy in order to reach the entire area under the printing material sheet B. Therefore, in a first phase, air flow of comparatively small volume but increased pressure is required to fulfill the function of reaching the whole arc surface.

If the printing material sheet B is then conveyed by other suckers in its plane in the direction of the sheet-processing machine, the carrying air cushion under the printing material B must remain intact for the best possible sheet conveying. For this it is advantageous to demand more air, but the printing material B must not flutter. Therefore, at this time, when the forward movement of the printing sheet B starts, an airflow of increased volume but lower pressure can be promoted. Therefore, it is provided that the blowing air generation, which is performed by the first ejector 3, to be designed so that a controller 12 is formed so that an air flow of short duration with increased pressure and low volume via the Blasluftleitung 23 delivered to the / the working members 24 becomes. For this purpose, the controller 12 is first connected to the solenoid valve 4 according to Figure 5, which is connected to the discharge of compressed air via the Blasluftleitung 5 with the ejector 3, wherein from the ejector 3, a first Blasluftstrom on the Blasluftleitung 23 to the / the work organs 24 generated is. Furthermore, in FIG. 5, the control is connected to a second solenoid valve 51 which is connected to a compressed air connection 7 and which is connected to a second ejector 30 via a blown air line 51 for the delivery of compressed air. that is. The second ejector 30 is connected with its air outlet 13 for delivering a corresponding second Blasluftstromes via a Blasluftleitung 52 with the / the same working organs 24, so that the second Blasluftstrom the same working organs 24 can be fed, which initially the first Blasluftstrom from the first ejector third had been supplied.

Adjusted by a control of the working cycle of the sheet processing machine controller 12, the second Blasluftstrom is discharged from the ejector 30 following the first Blasluftstrom in air generation and provided with a lower pressure and a larger volume than the first Blasluftstrom generated by the ejector 3 was. Furthermore, the second blown air stream can be dispensed over a longer period of time, so that the printing material B can be safely taken over by further conveying means. Also in this embodiment, the ejectors 3, 30 on the side of the

Blasluftaustritts the air outlet 13 in the Blasluftleitungen 23 downstream of an air control device 22 may be arranged by means of which the exiting suction air flow in the cycle of the sheet processing machine is controllable. This air control device 22 may be formed as a control roller.

In general, the following applies to all embodiments:

The solenoid valves 4, 10, 40, 50 are designed to time-release the pending on the compressed air supply 7 compressed air to the ejectors 3, 30 or lock. Solenoid valves are therefore well suited for this purpose in the region of the suction head 1, because they can be controlled in short and rapidly successive clock cycles and thus can follow the very short control times in machines which process very rapidly according to the state of the art. The solenoid valve 4 is further adapted to carry the compressed air in a second way or to block the compressed air from the ejector 3 and to establish a connection between further Blasluftleitungen. The design of solenoid valves and their switching options are well known, so that corresponding embodiments for known tasks are easy to find and used.

In all embodiments, one, several or each compressed air connection 7, a pressure control valve or at least one pressure gauge can be assigned. In this case, the arrangement can be provided so that a pressure control can be carried out individually or for several compressed air connections 7 together.

Furthermore, one, several or all Saugluftanschlüssen and / or Blasluftanschlüssen to ejectors 3, 10, 30 may be arranged a pressure control valve to make the suction air and / or blown air generated by the ejectors 3, 10, 30 adjustable in terms of their negative pressure or overpressure.

LIST OF REFERENCE NUMBERS

1 suction head

2 working organ

3 ejector

3.1 Air connection

3.2 Air connection

3.3 Air connection

4 solenoid valve

4.1 Blow air connection

4.2 Blown air outlet

5 blown air line

6 suction air line

7 compressed air connection

8 blown air line

9 branching

10 solenoid valve

1 1 blown air line

12 control

13 air outlet

22 air control

23 blown air line

24 working organ

30 ejector

40 solenoid valve

50 solenoid valve

51 blown air line

52 blown air line

printing material

Stack side edge

Claims

Patent claims

Device for air control on air consumers in the area of a sheet feeder of a sheet-processing machine, the sheet feeder having a suction head (1), the suction head (1) being equipped with working elements (2, 24) for separating or separating, removing and transporting loads. printing material sheet (B) is provided from the top of a stack of sheets in the sheet feeder and air generating devices with one or more ejectors (3, 10, 30) are provided, which are provided with one or more compressed air connections (7) and which are connected to the working elements (2 , 24) of the suction head (1) are connected via line connections (6, 23, 52),

characterized,

that the compressed air connection(s) (7) of an ejector (3, 30) is assigned a solenoid valve (4, 10, 40, 50), which is designed for the time-controlled supply of compressed air to the ejector (4) via a blown air line (5, 41, 51). is and that the ejector (3) is connected to one or more working elements (2, 24) via the line connections (6, 23, 52) and

that an air control device (22) is arranged in the line connections (9, 23, 52) between the ejector(s) (3, 30) and the working elements (2, 24), by means of which the air flows generated in the air generating devices are controlled in the working cycle and can be controlled over time.

Device according to claim 1,

characterized,

that a device for ventilation of suction air consumers is connected in the area between an ejector (3) and the working element(s) (2), the working element(s) (2) being connected via at least one suction air line (6) to an air connection (3.2) of the ejector ( 3) are connected for suction air, and that the device can be controlled as a bypass with a blown air line (8) from a first solenoid valve (4) for supplying blown air to the ejector (4) to the suction air line (6) between the ejector (3) and the working bodies (2) is arranged.

Device according to claim 1 or 2,

characterized,

that a device for ventilation of suction air consumers is connected in the area between an ejector (3) and the working element(s) (2) and that the device can be controlled independently of the first solenoid valve (4) as a blown air line (1 1) from a second solenoid valve (10 ) to the suction air line (6) is arranged between the ejector (3) and the working element(s) (2).

Device according to claim 1 or 2,

characterized,

that a device for ventilation of suction air consumers is connected in the area between an ejector (3) and the working element(s) (2) and that the device is formed by the first solenoid valve (4), the solenoid valve (4) being designed to be controllable in this way, that the blown air line (5) for connecting the solenoid valve (4) to the ejector (3) either in a connection with the compressed air connection (7) or in a connection with the blown air line (8), which is used to connect the solenoid valve (4) to the Suction air line (6) between the ejector (3) and the working element(s) (2) is switchable.

Device according to claim 1,

characterized,

that the working element(s) (24) are connected via at least one blown air line (23) to an air connection (3.3) of the ejector (3) for blown air.

Device according to claim 5,

characterized,

that the working element(s) (24) are designed as blowing devices and that the ejector (3, 30) is also used to generate suction air of blown air with low pressure and increased volume is used, the air emerging from the ejector (3, 30) being throttled in pressure and being enriched in volume with the air supplied via the air connection (3,2).

Device according to claim 5 or 6,

characterized,

that the supply of blown air to the working element(s) (24) takes place via an air control device (22) which is arranged directly behind the outlet from the or each ejector (3, 30).

Device according to one or more of claims 5 to 7,

characterized,

that if different qualities of blown air are required, such as when separating and carrying sheets during sheet separation, two air generating devices, each with one or a common compressed air connection (7), each with a solenoid valve (4, 50), each with a blown air line (5, 51), each an ejector (3, 30) and a blown air line (23, 52) to the working element(s) (24) are provided, the solenoid valves (4, 50) being arranged in a controllable manner in such a way that a blown air stream of higher pressure is first sent from one of the air generating devices and lower volume can be delivered and that a blown air stream of lower pressure and higher volume can then be given off by the air generating devices, and that the different blown air streams can be fed to the same working elements (24) one after the other.

Device according to one or more of claims 5 to 8,

characterized,

that the air generating devices are designed to supply different blown air streams to the same working organ(s) (24) or specifically to different working organs (24).

10. Device according to one or more of claims 1 to 9,

characterized,

that the solenoid valve(s) (4, 10, 40, 50) is assigned at least one controller (12) for the time-controlled supply of compressed air to the ejector(s) (3, 30) synchronized to the work cycle of the sheet processing machine.

1 1 . Device according to one or more of claims 1 to 10,

characterized,

that the air control device (22) is designed as a control roller, which has connections for the supply of suction air and / or blown air and a valve roller that can be driven in the machine cycle and rotates with passages for suction air and / or blown air as well as connections for the supply of suction air and / or blown air the working organ(s) (2, 24).

12. Device according to one or more of claims 1 to 11,

characterized,

that the suction head (1) has air generating devices with solenoid valves (4, 10, 40, 50) and ejectors (3, 30) for the joint or separate generation of suction air and blown air, the air generating devices each with corresponding suction air devices or as blown air devices trained working elements (2, 24) of the suction head (1) are connected via air lines (6, 23, 52).