DE10116698A1 - Regulating device for regulating pneumatically operated ejector which moves between working position and rest position through the underpressure chamber which is biased with the underpressure prevailing in the suction element - Google Patents

Abstract

The regulating device (3) has an excess pressure chamber (13) and intermediate chamber (16) connected to the atmosphere. The underpressure chamber (6) is biased with an under pressure which exists in the at least one suction element (17). Depending on the pressure level in the under pressure chamber the supply pressure line (3) in which the supply pressure prevails and which serves to supply the pneumatically operated ejector (4) is closed in the rest position and opened in the work position by means of a closing piston (2) and an adjusting member (10, 12) which is loaded with the underpressure prevailing in the under pressure chamber. Independent claim describes a system with an ejector comprising a turbo pump and the regulating device as above.

Description

The invention relates to a control device for controlling a pneumatic operated ejector, the at least one suction element with vacuum applied. This ejector is between a working position in which it is over a supply line is pressurized and a rest position, in which it is separated from the supply line, switchable.

Furthermore, the invention relates to a system that has an ejector, at least comprises a suction element and a control device of the type described.

In the context of the present invention, the term ejectors Devices are understood that are capable of negative pressure build up or generate. This also means vacuum pumps, negative pressure generating piston working machines and the like detected.

Only pneumatically operated ejectors should be considered here. H. Ejectors in operation by applying a pressure medium be taken. For example, this can be a turbopump a turbine mounted on a shaft serves as a drive and a pump drives.  

The ejectors in question generate a vacuum, with which then at least one suction element is applied. The one with negative pressure acted upon suction elements have a variety of uses and are used, for example, as lifting tools. numerous There are also possible uses when using vacuum acted upon suction elements as a transport and / or holding device. As The simple handling of these suction elements proves to be advantageous and their gentle and absolute compared to grippers and the like non-destructive fixation of the object to be fixed.

For the reasons mentioned is a main area of application of with negative pressure acted upon suction elements the glass processing industry, which due to the extremely fragile glass products an interest in gentle lifting, Has transport and holding tools.

The use of negative pressure is also widespread Suction elements in the automotive industry used in the manufacture of Motor vehicles and especially in the handling of painted Body parts from a quality point of view on careful handling with these parts.

A fundamental problem when dealing with vacuum is that Maintaining the negative pressure condition. Due to the fact that In principle, leaks are not completely avoided, but only with corresponding effort can be minimized, the vacuum will degrading more or less quickly over time without external intervention.

In the present case, in which a pneumatically operated ejector Vacuum generated and at least one suction element with this vacuum acted upon, this means that once generated by the ejector  Vacuum breaks down over time if this is not constantly through the ejector is renewed or regenerated.

The suction power of the at least one suction element depends crucially from the pressure level of the vacuum or the negative pressure, with Falling below a certain negative pressure to that of the suction element fixating object can no longer be held and it becomes a Failure or failure of the suction element comes.

This failure of the at least one suction element is said to be in practice can be avoided, since a failure of the suction element usually leads to a Destruction of the object fixed by the suction element leads. Of Furthermore, failure of the suction element is critical from a safety point of view judge, because of objects that are suddenly no longer fixed Damage, especially injury to people, is to be feared.

In this context, the period of time is the life of the suction element understood in which the suction element without constant renewal of the Vacuum, d. H. after a single generation of the negative pressure, a can apply predetermined force.

As a rule, the suction elements described on ejectors are at the beginning described type connected, whereby the generated once in them Vacuum can be renewed if necessary.

According to the prior art, however, these are the problems described above and the resulting consequences are not eliminated. So with electrical operated ejectors a power failure to make the ejector unavailable lead, so that then a failure of the Suction element occurs.  

For this reason, the scope of the invention is only intended to be pneumatic operated ejectors are considered that do not pose a risk, due to a power outage itself no longer available if necessary his.

Another reason for the limitation of the subject of the invention is due to the fact that compressed air is cheap, compressed air lines are easy and inexpensive to lay and the handling of compressed air below Security aspects seems favorable.

Another disadvantage with those used in the prior art Suction elements or in accordance with the prior art for generating the Vacuum ejector used is the regulation.

On the one hand, this regulation must monitor the negative pressure in the suction element and, on the other hand, regulate the ejector depending on this negative pressure, ie switch it on or off. The control system is basically given a lower vacuum threshold value p _{s, below} and an upper vacuum threshold value p _{s, above} , between which the vacuum in the suction element can vary without endangering the functionality of the suction element, the vacuum not greater than that upper vacuum threshold p _{s, above} and not less than the lower vacuum threshold p _s, may be _below . Depending on the negative pressure present in the suction element, the ejector should be switched off or on.

At this point it should be mentioned that in the context of the present invention with Negative pressure, especially with the upper and lower negative pressure Threshold value, not the absolute pressure in the suction element is designated, but the difference in amount between that in the suction element prevailing, absolute pressure and the ambient or Atmospheric pressure.  

According to the state of the art, these regulations work at least partially electrical, which is why the failure of the control and thus the Entire system can also not be prevented in the event of a power failure.

Against this background, it is the object of the present invention, a Control device for controlling a pneumatically operated ejector, the vacuumed at least one suction element to provide the works according to purely mechanical or pneumatic principles and also at Power failure the functionality of the at least one suction element guaranteed.

Furthermore, it is an object of the invention to provide a generic system Provide a type that remains functional even in the event of a power failure.

This object is achieved by a control device for controlling a pneumatically operated ejector, the p least one suction element with vacuum or negative pressure is applied _under pressurized and movable between a working position in which it via a supply line with pressure, and a rest position in which it from the supply pressure line is separated, switchable, with a vacuum chamber in which:

• - The vacuum chamber, with the vacuum p _under, which is present in the at least one suction element
• - and in dependence on the pressure level of the supply pressure line, in which the supply pressure p p _under the Unterdruckkammmer _ver prevails and which provides power to the pneumatically operated ejector, is acted upon by force by means of a closing piston and an actuator, the p with the pressure prevailing in the vacuum chamber vacuum _under , is closed in the rest position and open in the working position.

The control works according to mechanical and pneumatic principles and is independent of the availability of electrical energy.

This regulation is basically one closed control loop, which is used in many technical processes finds and whose task is to create a controlled variable on a given Keep setpoint, even if disturbances have a disturbing effect. It is Rules a procedure in which the controlled variable is continuously recorded and with the Setpoint or the reference variable is compared, depending on this Comparison via corresponding changes in the manipulated variable to the controlled variable Guide size is adjusted.

In the present case, the control of a negative pressure p applied _under suction element, the control variable, the negative pressure is p _less. This is continuously recorded in that the vacuum chamber is acted on by a suction line from the suction element.

There is no comparison of the controlled variable p _under with a predetermined reference variable in the conventional sense. According to the invention, the supply pressure p _ver functioning as a manipulated variable is not influenced as a function of a pressure difference determined as part of a comparison of the controlled variable with a reference variable, but rather directly as a function of the negative pressure p _under in the vacuum chamber or the suction element. As a result, this procedure is equivalent or equivalent to the conventional procedure of the closed control loops described at the beginning.

In dependence on the continuously detected negative pressure p _under (controlled variable) will influence on the supply pressure p _ver serving as a manipulated variable, taken, wherein the supply pressure p _ver, which provides power to the pneumatically operated ejector, its task accordingly influence on the suction member and thus in the underpressure chamber present underpressure p _takes.

The change in the supply pressure p _ver as a function of the negative pressure p _under takes place by means of a closing piston and an actuator.

Embodiments of the control device are advantageous, which are characterized in that the control device comprises an overpressure chamber and an intermediate chamber, which is connected to the atmosphere, and

• - The vacuum chamber has a flexible membrane and in the vacuum chamber itself on this membrane supporting spring element is arranged,
• - The pressure chamber, which is connected to the intermediate chamber at least when there is a lower negative pressure threshold p _{S, below} in the negative pressure chamber, and is at least separate from the intermediate chamber when an upper negative pressure threshold p _{S, above} in the negative pressure chamber is prevails, and in which a spring element is arranged, p means of a pressure line with pressure applied to it _via,
• - and in dependence on the pressure level of the supply pressure line P _via the Überdruckkammmer by means of a closing piston in the rest position is closed and is opened in the working position,
• - is subjected to a force _over in such a way that the actuator is on the one hand subjected to a force on the disposed in the vacuum chamber spring element and due to the pressure difference across the membrane of the vacuum chamber and on the other hand p about arranged in the overpressure chamber a spring element and as a result of the pressure prevailing in this chamber pressure, and
• - the closing piston on the one hand subjected to a force P on the voltage applied to a membrane of a sub-chamber of the pressure chamber pressure _above and on the other hand on the pressure prevailing in the supply pressure line pressure p _ver,
• - wherein, depending on the negative pressure p _below in the vacuum chamber, on reaching the upper vacuum threshold value p _{S, above} the actuator in the manner of the position change, that the pressure chamber is separated from the intermediate chamber, consequently into the overpressure chamber and the associated auxiliary chamber p pressure can build up _on acting through the membrane on the closing piston and on reaching a predetermined size includes the supply pressure line by means of the closing piston, and
• - When a lower negative pressure threshold p _{S is reached,} the actuator changes the position in such a way that the positive pressure chamber is connected to the intermediate chamber, consequently, atmospheric pressure is established in the positive pressure chamber and the associated secondary chamber, which acts on the closing piston via the membrane , which opens the supply pressure line.

In these embodiments, the controlled variable p is coupled _below and the manipulated variable p _ver by means of the closing piston and the actuator in such a way that the actuator is essentially acted upon by four forces.

On the one hand acts on the actuator of the pressure prevailing in the vacuum chamber _under negative pressure p, the abutting on the opposite side of the membrane ambient pressure and the spring force of which is arranged in the vacuum chamber spring element. On the other hand acts on the actuator of the pressure prevailing in the pressure chamber pressure p _across and the spring force of which is arranged in the pressure chamber spring element. The restoring forces in the membrane of the vacuum chamber, which is continuously elastically deformed, can generally be neglected when considering the actuating element under load. However, it is possible to use the restoring forces of the elastically deformed membrane by using a corresponding membrane in order to influence the balance of forces of the actuator.

Due to the fact that the actuator moves during the control process, the spring elements are deformed and the spring forces are changed and both the negative pressure p _below in the negative pressure chamber and the positive pressure p _above vary in the positive pressure chamber, these are the ones acting on the actuator Forces around time-varying variables and thus a dynamic balance of forces.

The actuator changes as a result of the forces acting on the actuator continuously between two end or stop positions, whereby in the upper stop position the pressure chamber from the intermediate chamber is separated so that an overpressure can build up in it.

The slowly building up overpressure p _over in the overpressure chamber also acts in a secondary chamber of the overpressure chamber, in which this overpressure p _over acts on a membrane, which in turn acts on a closing piston with force, so that the closing piston on one side of the overpressure p _over Overpressure chamber or the secondary chamber is exposed, while on the other side the supply pressure p _{ver of} the supply pressure line is present. Depending on the size of the areas where the pressures p _above and p _ver attack and depending on the magnitude of these pressures itself, moves the closing piston and closes the supply pressure conduit when the pressure p _into the secondary chamber a certain, predetermined pressure value is reached ,

As a result of the closed supply pressure line, the one for the drive is missing of the ejector required supply pressure, which causes the ejector in the Rest position is switched and therefore no negative pressure in the suction element can generate or regenerate. As a result of the ejector switched off and never The vacuum in the suction element and thus decrease in the vacuum chamber.

As a result of the decreasing negative pressure, the force introduced into the actuator from the side of the negative pressure chamber increases over time, so that the positive pressure chamber is reconnected to the intermediate chamber when the pressure drops below a certain negative pressure. Consequently, the pressure built up in the pressure chamber pressure may be p _on over the connected with the atmosphere intermediate chamber degrade the closing piston as a result of the sinking excess pressure p _into the secondary chamber and constantly connected supply pressure p _ver in the manner of moving, that the supply pressure line is released, and the ejector is switched to the working position. The re-operating ejector counteracts the reduction of the vacuum in the suction element and thus the reduction of the vacuum in the vacuum chamber.

Owing to the described operations of the negative pressure fluctuates p _less continuously between an upper vacuum threshold value p _{S, upper} and lower vacuum threshold value p _{S, below.}

Embodiments of the control device in which the Overpressure line by means of a connecting line with the Supply pressure line is connected.

It is favorable in this embodiment that the overpressure line, via which the overpressure chamber acts _on the overpressure p, is fed by the supply pressure line. This eliminates the need for additional pressure lines or the provision of several pressure medium reservoirs.

Control devices which are characterized in that a throttle point is arranged in the connecting line, wherein preferably a nozzle serves as a throttle.

Is intended advantages, these embodiments within the scope of control to the timing at which the pressure chamber is again connected to the intermediate chamber and the pressure built up in the pressure chamber pressure p _over through the intermediate chamber which is connected to the atmosphere which degrade.

The throttle ensures that the existing in the pressure chamber Pressure medium faster and easier via the intermediate chamber in the Can escape as a new pressure medium via the Supply line of the hyperbaric chamber is supplied because the Throttle point leads to a pressure loss and the unimpeded inflow of printing medium brakes or slows down.

Embodiments of the control device are advantageous in which the Actuator is modular. This allows individual components in different series are used and an adjustment of the Complete system by replacing individual parts. Furthermore, the modular design of the actuator also advantages with regard to assembly, preferably the actuator comprises a plunger and a socket. Stamp and socket can in turn be modular.

The stamp usually consists of a plate and a stamp leg, the stamp leg and the stamp plate each being an independent component could be. The stamp leg is in the socket, which in the  Hyperbaric chamber is arranged, stored and in some Embodiments connected to this via a press fit.

In this case, then the outer shape of the sleeve determines the surface to which the pressure prevailing in the pressure chamber pressure p _over attacks, and thus the geometrical dimensions determine the socket, the p from the positive pressure _on the stamp or the actuator forces exerted.

Embodiments of the control device are advantageous in which an adjusting screw is provided for prestressing the spring element arranged in the vacuum chamber. By means of this adjusting screw, the spring force acting on the actuator from the spring element is influenced, whereby an adjustment of the pressure window, which is spanned by the upper negative pressure threshold value p _{S, above} and the lower negative pressure value p _{S, below} , is possible ,

Embodiments of the control device in which one Seal is provided on the actuator, which the pressure chamber against Intermediate chamber seals when they are separated.

The second sub-object of the invention is solved by a system that one Ejector, comprising at least one suction element and a control device, at which the ejector comprises a turbopump and the control device one Control device according to one of claims 1 to 9.

This subtask is also solved by a system that includes an ejector, comprises at least one suction element and a control device in which the Ejector comprises a Venturi nozzle and the control device one Control device according to one of claims 1 to 9.

The invention is described below using an exemplary embodiment of the drawing figures 1 to 4 explained. Here shows:

Fig. 1 shows an embodiment of the overall system in side view, in section,

Fig. 2 shows the control device of the overall system illustrated in Fig. 1 in the working position,

Fig. 3 shows the control device of the overall system shown in Fig. 1 in the rest position and

Fig. 4 shows the time course of the vacuum p (t) in the vacuum chamber.

Fig. 1 shows the overall system which comprises a control device 1, an ejector 4, and a suction member 17th

The ejector 4 is designed as a Venturi nozzle and is supplied in the state shown in FIG. 1 via a supply pressure line 3 with a pressure medium which has the pressure p _ver . The pressure medium flows through the ejector or the Venturi nozzle 4 , a negative pressure being generated by the expansion of the pressure medium when leaving the Venturi nozzle 4 . This negative pressure ensures that the check valve 5 , which separates the ejector 4 and the suction element 17 from one another in the closed state, is opened when the pressure on the ejector side is so much smaller than the pressure p _below on the side of the suction element 17 that the Restoring force in the check valve 5 is overcome. When the non-return valve 5 is open, the ejector 4 generates a negative pressure p _below , the non-return valve closes when the negative pressure p prevailing in the suction element 17 reaches _below a certain value.

The suction member 17 is connected to the control device 1 in such a manner that a feed line 18 connects the suction member 17 with the negative pressure chamber 6, whereby the negative pressure chamber 6 with p prevailing in the suction member 17 is urged _under vacuum.

The vacuum chamber 6 has a flexible membrane 7 and a spring element 8 in the form of a coil spring. The coil spring 8 can be biased with the aid of an adjusting screw 9 .

This helical spring 8 is supported at one end on the adjusting screw 9 and at the other end via a plate 26 on the punch 10 . The stamp 10 in turn sits itself in the bushing 12 , which is arranged in the overpressure chamber 13 and on which a spring element 22 is supported. In the present exemplary embodiment, this spring element 22 is also a helical spring, which is supported with its second end on the inner walls of the overpressure chamber 13 .

The pressure chamber 13 has a secondary chamber 14 , through which a membrane 23 is accessible. A closing piston 2 is arranged on the other side of the membrane 23 and closes or releases the supply pressure line 3 as a function of the pressure conditions ( FIG. 3) or releases it ( FIG. 2).

The pressure chamber 13 is pressurized via a pressure line 24 . In the present exemplary embodiment, this overpressure line 24 is connected to the supply pressure line 3 by means of a connecting line 21 . The supply pressure line 3 thus serves both to supply the ejector 4 with pressure medium and to supply the pressure chamber 13 . According to a preferred embodiment, a nozzle 19 is arranged in the connecting line 21 and throttles the pressure medium supplied to the overpressure chamber 13 .

The control device 1 is explained in detail in the context of the description of FIGS. 2 and 3. In this context, details are also given about the temporally changing mechanical and pneumatic forces. The Figs. 2 and 3 show the control device 1 in the two for the control device 1 characteristic states.

Fig. 2 shows the control device 1 in the working position of the ejector 4 , in which the closing piston 2 releases the supply pressure line 3 .

The ejector generates an increasing vacuum p _under in the suction element and thus in the vacuum chamber 6 . In the illustrated in Fig. 2 state of the control device 1 of the negative pressure is p _less in the vacuum chamber 6 is still so low that the diaphragm is domed 7 to the outside. On the plate 10 'of the stamp acts on the one hand the spring force of the spring element 8 and on the other hand the compressive force which results from the product of the pressurized membrane surface and the pressure difference across the membrane 7 . The membrane 7 is on the one hand acted upon by the pressure prevailing in the vacuum chamber 6 and negative pressure p _with p other hand, under the influence of the supplied via the feed line 15 ambient pressure _environment.

These forces acting on the upper end of the stamp move the plate 10 'of the stamp downward, whereby this moves a bushing 12 downward via a leg 10 "against the spring force of a spring element 22. Because the plate 10 ' and the leg 10 " of the plunger to move the bushing 12 against the spring force of the spring element 22 , the pressure chamber 13 , in which the bushing 12 and the spring element 22 are arranged, is connected to the intermediate chamber 16 , which has a feed line 20 to the atmosphere.

As a result of the connection of the pressure chamber 13 and the intermediate chamber 16 and the resulting connection of the pressure chamber 13 to the atmosphere, there is approximately ambient pressure in the pressure chamber 13 , although the pressure chamber 13 is constantly connected via a pressure line 24 , which is connected to the supply pressure line 3 by means of a connecting line 21 , is pressurized.

In this state, there is also approximately ambient pressure in the secondary chamber 14 , which is part of the overpressure chamber 13 , so that the closing piston 2 on the side which is directed towards the overpressure chamber 13 , partly over the secondary chamber 14 or over this secondary chamber 14 limited membrane 23 is subjected to approximately ambient pressure and on the other hand, on the side which is directed to the supply line 3 , the supply pressure p is applied _ver . As a result, the closing piston 2 is held in its upper position, whereby the supply pressure line 3 is released.

After a certain period the negative pressure is p _less in the vacuum chamber 6 is sufficiently large so that the plate connected to the diaphragm 7 10 'of the punch due to the increased pressure differential across the membrane 7 against the acting upon it, the spring force of the spring element 8 under compression of the spring element 8 is raised. As a result, the leg 10 "of the modularly constructed stamp is no longer subjected to force from the side of the vacuum chamber 6 or the plate 10 '.

The membrane 7 is curved inwards, ie into the vacuum chamber 6 , as shown in FIG. 3. The spring element arranged in the overpressure chamber 13 can now move the bushing 12 , on which the spring element 22 is supported, due to the lack of counter forces or the lack of resistance generated by the vacuum chamber 6 while the spring element 22 is expanding. The bushing 12 is brought into abutment with a further bushing 25 , so that the pressure chamber 13 is separated from the intermediate chamber 16 and thus from the environment.

The pressure medium supplied via the overpressure line 24 can no longer escape into the environment via the intermediate chamber 16 and the feed line 20 . In contrast, the medium flowing into the overpressure chamber 13 now builds up a continuously increasing overpressure p _over . This overpressure p _over has the result that, on the one hand, the bushing 12 with the seal 11 arranged in it is pressed against the bushing 25 under ever greater force, thereby improving the sealing of the overpressure chamber with respect to the intermediate chamber 16 and thus with respect to the atmosphere.

On the other hand, the continuously increasing overpressure p _via in the overpressure chamber 13 and thus in the secondary chamber 14 ensures that when a certain pressure level is reached, the diaphragm 23 bulges outwards and the closing piston 2 against the supply pressure p _ver prevailing on the supply pressure line 3 side shifts the way that the supply pressure line 3 is closed, as shown in Fig. 3.

It is the rest position in which the ejector is no longer supplied with a pressure medium via the supply pressure line 3 . It is switched off, so to speak, so that the vacuum prevailing in the suction element or in the vacuum chamber 6 is not renewed or regenerated, so that the vacuum continuously breaks down over time as a result of leaks which can never be completely avoided.

As a result of the decreasing negative pressure and a consequently decreasing pressure difference across the membrane 7 of the negative pressure chamber 6 , the force relationships in the area of the negative pressure chamber 6 change in such a way that the spring element 8 expands and the stamp consisting of plate 10 'and leg 10 "downwards As a result, the bushing 12 , in which the leg 10 "of the plunger is mounted, is also pressed downward against the spring force of the spring element 22 of the overpressure chamber 13 . This leads to a compound of the pressure chamber 13 with the intermediate chamber 16 and thus can decompose with the atmosphere, whereby the built up in the pressure chamber 13 _via pressure p.

As a result of these operations, the closing piston 2 as shown in Fig. 2 is shown, under the action of the pressure prevailing in the supply pressure line 3 supply pressure p _ver in its upper position and outputs the supply pressure line 3 freely, while the membrane deflects inwardly. The ejector is again supplied with a pressure medium via the supply pressure line 3 now released by the closing piston 2 . The cycle starts again.

Fig. 4 shows the course of the vacuum p _under in the vacuum chamber over time. This fluctuates within a vacuum window, which _is limited by the two threshold values p _{S, above} and p _{S, below} .

The curve shows, for example, the points at which the closing piston opens (state 4) or closes (state 3) and at which the pressure chamber is separated from the intermediate chamber (state 1) or connected to it (state 2). Because of this, dynamic regulated total system, these points are not maximum at the points or minimum underpressure p _As, that is, do not lie at the locations at which the negative pressure p _below in the vacuum chamber its upper vacuum threshold value p _{S, above} or its lower vacuum threshold value p _S, reached _below .

The time on the function curve is marked with 1, at which the pressure chamber is separated from the intermediate chamber and an overpressure p _over slowly builds up in the pressure chamber. It takes a certain amount of time to build up a sufficiently high overpressure p _over in the overpressure chamber, which is required to move the closing piston. Consequently, the vacuum p _under in the vacuum chamber increases even when the pressure chamber is separated from the intermediate chamber. When a certain overpressure p is _reached in the overpressure chamber and the secondary chamber, the closing piston is displaced and the supply pressure line is closed by means of this closing piston. This time is marked with 3.

Point 3 is approximately at the point of the maximum negative pressure p _below = p _{S, above} . In practice, however, there is a certain time delay because even after the supply pressure line is closed, the ejector does not switch off immediately without a time delay and the overall system has a certain inertia due to the line carrying the pressure medium.

The situation is similar to that for the upper negative pressure threshold p _S, described _above , in the region of the lower negative pressure threshold value p _{S, below} . After the ejector is switched off, the negative pressure is continuously reduced due to leakages. When a certain underpressure is reached, the overpressure chamber is reconnected to the intermediate chamber, as a result of which the overpressure p _over built up in the overpressure chamber is reduced. Also, this degradation of the excess pressure p _into the hyperbaric chamber takes time, so that opening of the closing piston, thereby releasing the supply pressure line is staggered. The point 2, to which the overpressure chamber and intermediate chamber are connected to one another, is therefore somewhat before the lower vacuum threshold value p _{S is reached} . First, the pressure P builds _on from the pressure chamber, followed by a time offset of the closing piston (time 4) and the ejector the eroding vacuum can regenerate in the suction member.

LIST OF REFERENCE NUMBERS

1

control device

2

closing piston

3

Supply pressure line

4

ejector

5

check valve

6

Vacuum chamber

7

membrane

8th

spring element

9

adjustment

10

stamp

10

' Plate

10

"Leg

11

poetry

12

Rifle

13

Hyperbaric chamber

14

secondary chamber

15

supply

16

intermediate chamber

17

suction

18

supply

19

jet

20

supply

21

connecting line

22

spring element

23

membrane

24

Pressure relief line

25

Rifle

26

Plate

Claims (11)

1. Control device ( 1 ) for controlling a pneumatically operated ejector ( 4 ) which acts on at least one suction element ( 17 ) with a vacuum and between a working position in which it is pressurized via a supply line ( 3 ) and a rest position, in which it is separated from the supply pressure line ( 3 ), is switchable, with a vacuum chamber ( 6 ), in which
the vacuum chamber ( 6 ) with which the vacuum (p _under ) is present, which is present in the at least one suction element ( 17 )
and depending on the pressure level (p _under ) in the vacuum chamber ( 6 ) the supply pressure line ( 3 ) in which the supply pressure (p _ver ) prevails and which serves to supply the pneumatically operated ejector ( 4 ) by means of a closing piston ( 2 ) and an actuator ( 10 , 12 ) which is pressurized with the negative pressure (p _under ) prevailing in the negative pressure chamber ( 6 ), closed in the rest position and open in the working position. 2. Control device according to claim 1, characterized in that
the control device ( 3 ) comprises an overpressure chamber ( 13 ) and an intermediate chamber ( 16 ) which is connected to the atmosphere, and
the vacuum chamber ( 6 ) has a flexible membrane ( 7 ) and a spring element ( 8 ) which is supported on this membrane ( 7 ) is arranged in the vacuum chamber,
the pressure chamber ( 13 ) which is connected to the intermediate chamber ( 16 ) at least when a lower vacuum threshold value (p _{S, below} ) prevails in the vacuum chamber ( 6 ) and is at least then separated from the intermediate chamber ( 16 ), if an upper vacuum threshold value (p _{S, above} ) prevails in the vacuum chamber ( 6 ), and in which a spring element ( 22 ) is arranged, an excess pressure (p _over ) is applied to it by means of an overpressure line ( 24 ),
and depending on the pressure level (p _over ) in the overpressure chamber ( 13 ), the supply pressure line ( 3 ) is closed in the rest position by means of a closing piston ( 2 ) and opened in the working position,
in such a way that the actuator ( 10 , 12 ) is pressurized on the one hand via the spring element ( 8 ) arranged in the vacuum chamber ( 6 ) and due to the pressure difference across the membrane ( 7 ) of the vacuum chamber ( 6 ) and on the other hand via that in the pressure chamber ( 13 ) arranged spring element ( 22 ) and as a result of the pressure (p _over ) prevailing in this chamber ( 13 ), and
the closing piston ( 2 ) is pressurized on the one hand by the pressure (p _over ) applied to a diaphragm ( 23 ) of a secondary chamber ( 14 ) of the overpressure chamber ( 13 ) and on the other hand by the pressure (p _ver ) prevailing in the supply pressure line ( 3 ),
whereby depending on the vacuum (p _under ) in the vacuum chamber ( 6 ), when the upper vacuum threshold value (p _{S, above} ) is reached, the actuator ( 10 , 12 ) changes the position in such a way that the pressure chamber ( 13 ) of the Intermediate chamber ( 16 ) is separated, consequently a pressure (p _over ) can build up in the overpressure chamber ( 13 ) and the associated secondary chamber ( 14 ), which acts on the closing piston ( 2 ) via the membrane ( 23 ) and when a predetermined one is reached Size by means of the closing piston ( 2 ) closes the supply pressure line ( 3 ), and
when a lower vacuum threshold value (p _{S, below} ) the actuator ( 10 , 12 ) changes position such that the pressure chamber ( 13 ) is connected to the intermediate chamber ( 16 ), consequently located in the pressure chamber and the associated one Secondary chamber ( 14 ) sets atmospheric pressure, which acts on the closing piston ( 2 ) via the membrane ( 23 ), whereby the supply pressure line ( 3 ) is opened. 3. Control device according to claim 2, characterized in that in the control device ( 3 ) the pressure line ( 24 ) by means of a connecting line ( 21 ) with the supply pressure line ( 3 ) is connected. 4. Control device according to claim 3, characterized in that a throttle point ( 19 ) is arranged in the connecting line. 5. Control device ( 1 ) according to claim 4, characterized in that a nozzle ( 19 ) serves as a throttle point ( 19 ). 6. Control device ( 1 ) according to one of the preceding claims, characterized in that the actuator ( 10 , 12 ) is modular. 7. control device (1) according to claim 6, characterized in that the actuator (10, 12) a punch (10) and a socket (12). 8. Control device ( 1 ) according to one of claims 2 to 7, characterized in that an adjusting screw ( 9 ) for prestressing the spring element ( 8 ) arranged in the vacuum chamber ( 6 ) is provided. 9. Control device ( 1 ) according to one of claims 2 to 8, characterized in that a seal ( 11 ) is provided on the actuator ( 10 , 12 ) which seals the pressure chamber ( 13 ) against the intermediate chamber ( 16 ) when this ( 13 , 16 ) are separated from each other. 10. System, comprising an ejector (4), at least one suction element (17) and a control device (1), characterized in that the ejector (4) comprises a turbo pump (4) and the control device comprises a control device according to one of claims 1 to 9. 11. System, comprising an ejector (4), at least one suction element (17) and a control device (1), characterized in that the ejector (4) comprises a Venturi nozzle (4) and the control device comprises a control device according to one of Claims 1 to 9 is.