PNEUMATIC SYSTEM AND PROCESS

A pneumatic system, including a valve arrangement with a carrier section and several valve modules which are arranged in or on the carrier section, in which each valve module includes at least one valve unit and in which the carrier section comprises a plurality of working ports. Each working port can be selectively pressurised or exhausted via a respectively assigned valve unit. The pneumatic system further includes a hose arrangement and at least one pneumatic consumer with a compressed air receiving space which via the hose arrangement is pneumatically connected to at least two of the working ports, so that by way of this the valve units which are assigned to these working ports are pneumatically interconnected and the compressed air receiving space can be simultaneously pressurised and/or exhausted via at least these two interconnected valve units.

The invention relates to a pneumatic system, comprising a valve arrangement with a carrier section and several valve modules which are arranged in or on the carrier section, wherein each valve module comprises at least one valve unit and wherein the carrier section comprises a plurality of working ports, wherein each working port can be selectively pressurised or exhausted via a respective assigned valve unit, wherein the pneumatic system further comprises a hose arrangement and at least one pneumatic consumer with a compressed air receiving space. The pneumatic consumer is for example a pneumatic drive cylinder and the compressed air receiving space is for example a pressure chamber.

SUMMARY

An object of the invention lies in permitting the pressurising or exhausting of the compressed air receiving space with a greater throughput of compressed air, in an efficient manner.

The object is achieved by a pneumatic system as discussed herein. The pneumatic consumer is pneumatically connected to at least two of the working ports via a hose arrangement, so that by way of this the valve units which are assigned to these working ports are pneumatically interconnected and the compressed air receiving space can be simultaneously pressurised and/or exhausted via at least these two interconnected valve units.

What is meant by the term “pressurising” is the feeding of compressed air and by the term “exhausting” the discharging of compressed air.

The maximal compressed air throughput which is available at a working port for pressurising or exhausting in particular is limited by the design of the respectively assigned valve unit. In order to permit a greater pressurised air throughput at a working port, it is conventionally necessary to apply a larger valve module for this working port, said valve module comprising a valve unit which is designed for a greater compressed air throughput. Due to the approach according to the invention, of pneumatically connecting at least two working ports to the same compressed air receiving space, it is possible to pressurise or exhaust the compressed air receiving space with a greater compressed air throughput without having to apply another or larger valve module for this.

What is meant by the wording that the valve units are pneumatically interconnected valve units is that the valve units are pneumatically connected in parallel to one another. A compressed air flow which is provided by a compressed air source divides into several part-flows which flow parallel to one another through the interconnected valve units and parallel to one another through the assigned working ports. Expediently, the part-flows are then led together in the hose arrangement or in the compressed air receiving space. The interconnected valve units can also be denoted as linked valve units and the working ports which are assigned to these interconnected valve units can also be denoted as linked working ports.

On account of pneumatic interconnecting the valve units, the pressurising or exhausting of the compressed air receiving space can preferably be effected with a compressed air throughput which is larger than a maximal possible compressed air throughput of each individual one of the pneumatically interconnected valve units. According to the invention, a physical linking of several working ports of a valve arrangement (in particular of a valve terminal) can be effected for increasing the throughput.

Advantageous further developments are defined in the dependent claims.

The invention further relates to a method for operating the pneumatic system, comprising the step: simultaneous pressurising or exhausting of the compressed air receiving space via the interconnected valve units.

DETAILED DESCRIPTION

FIG.1shows a pneumatic system1which comprises a valve arrangement2and at least one pneumatic consumer6. By way of example, the pneumatic system1comprises four pneumatic consumers6which hereinafter are to be denoted as the first consumer6a, second consumer6b, third consumer6cand fourth consumer6d. The terms “first”, “second”, etc. are to serve for the termed differentiation of the consumers6and in particular not as a detail as to how many consumers6are present. Each of the consumers6can also be present without the other consumers6.

Preferably, the pneumatic system1comprises a control device7which in particular is designed as a super-ordinate control, for example as a PLC (programmable logic controller), a compressed air source8, a compressed air sink9and/or a user device10. The pneumatic system1further comprises at least one hose arrangement14.

The pneumatic system1is an exemplary application environment for the valve arrangement2. The valve arrangement2can also be provided on its own-thus in particular without the further components of the pneumatic system1.

The valve arrangement2comprises a carrier section3and several valve modules4which by way of example are arranged on the carrier section3. According to an alternative design, the valve modules can be arranged in the carrier section. The carrier section3by way of example is designed in a plate-like manner and in particular comprises an upwardly directed equipping side, on which the valve modules4are attached. The valve modules4are preferably designed in a plate-like manner and are expediently arranged next to one another in a rowing direction11. The rowing direction11expediently runs normally to the plate plane of the valve modules4. Each valve module4comprises at least one valve unit5. By way of example, each valve module4comprises two valve units5, in particular exactly two valve units5.

The carrier section3comprises a plurality of working ports12. By way of example, the working ports12are arranged on a connection side13of the carrier section3. The connection side13in particular is aligned orthogonally to the equipping side. The working ports12are expediently designed as openings, in particular as round openings, in the connection side13. By way of example, the working ports12form two working port rows which by way of example are arranged above one another. By way of example, precisely two working ports12are assigned to each valve module5. Expediently, precisely one valve element5is assigned to each working port12, so that expediently a1:1assignment exists between the working ports12and the valve units5.

Each working port12can be selectively pressurised or exhausted via the respectively assigned valve element5. What is meant by the wording that a valve unit5is assigned to a working port12is that compressed air can be fed to the working port12or discharged from the working port12(in particular exclusively) via this valve unit5. Compressed air can be fed from the compressed air source8to the respective working port12and/or compressed air can be led away from the respective working port12to the compressed air sink9, via the respectively assigned valve unit5.

By way of example, the valve arrangement2, in particular the carrier section3comprises a compressed air inlet21, to which the compressed air source8is pneumatically connected. Expediently, the valve arrangement2, in particular the carrier section3comprises a compressed air outlet22which is pneumatically connected to the compressed air sink9. The compressed air sink9for example can be the surroundings of the valve arrangement2.

FIG.2shows an exemplary embodiment of a valve device20. By way of example, each valve module4comprises a respective valve device20. The subsequent explanations which are directed to a valve device20expediently also apply to each valve device20of the valve arrangement2. The valve device20expediently comprises two valve units5which are to be denoted as the first valve unit5aand the second valve unit5b. By way of example, the valve device20is designed as a pneumatic full bridge and each valve unit5a,5brepresents a pneumatic half bridge. Each valve unit5comprises a respective valve unit outlet23with which the valve unit5is pneumatically connected to the respectively assigned working port12, for example via a respective pneumatic conduit which runs through the carrier section3. The first valve unit5comprises a first valve unit outlet23aand the second valve unit5comprises a second valve unit outlet23b.

Each valve unit5is in the position of selectively pressurising or exhausting the working port12which is assigned to it. By way of example, each valve unit5comprises two respective valves24which are also to be denoted as a first valve24a(or pressurising valve24a) and second valve24b(or exhausting valve24b). The valves24are designed for example as 2/2-way valves-Preferably, the valves24are designed as piezovalves. In particular, the valves24are designed as proportional valves. Concerning each valve24, expediently a throughput cross section can be freely set between a closed state and a maximally open state, in particular by way of a control signal28which is fed to the respective valve unit5. Each first valve24ais connected between the compressed air source8and the respective valve unit outlet23and expediently serves for setting a compressed air throughput from the compressed air source8to the respective working port12which is connected to the respective valve unit outlet23. Each second valve24bis connected between the compressed air sink9and the respective valve unit outlet23and expediently serves for setting a compressed air throughput from the respective working port12which is connected to the respective valve unit exit23, to the compressed air sink9.

The valve arrangement2preferably comprises a plurality of valve units5. Each valve unit5can expediently be selectively pressurised or exhausted (independently of the other valve units5).

Preferably, the pneumatic system1comprises a plurality of sensor units18. By way of example, a respective sensor unit18is assigned to each valve unit5. For example, each sensor unit18is designed as a pressure sensor and in particular serves for detecting the compressed air pressure which prevails at the respectively assigned working port12. The sensor units18are preferably arranged in the carrier section3. Moreover, the sensor units18can be arranged in the valve modules4.

The pneumatic system1comprises the at least one hose arrangement14. By way of example, the pneumatic system1comprises three hose arrangements14which hereinafter are to be denoted as the first hose arrangement14a, the second hose arrangement14band the third hose arrangement14c.

The at least one pneumatic consumer6comprises a compressed air receiving space15which is preferably designed as a pressure chamber. By way of example, each of the pneumatic consumers6a,6b,6c,6dcomprises (at least one) respective compressed air receiving space15which in particular is designed as a pressure chamber. By way of example, at least one pneumatic consumer6is designed as a pneumatic drive cylinder and expediently comprises a first compressed air receiving space15awhich is designed as a first pressure chamber and a second compressed air receiving space15bwhich is designed as a second pressure chamber. In the shown example, the third pneumatic consumer6cand the fourth pneumatic consumer6dare each designed as a pneumatic drive cylinder. Optionally, the first pneumatic consumer6aand/or the second pneumatic consumer6bcan be designed as a pneumatic drive cylinder.

At least one pneumatic consumer6is pneumatically connected to at least two of the working ports12via at least one hose arrangement14. Expediently, by way of this, the valve units5which are assigned to these working ports12are pneumatically interconnected and the compressed air receiving space15of the at least one pneumatic consumer6can be simultaneously pressurised and/or exhausted via at least these two interconnected valve units5. The interconnected valve units5can comprise valve units5of the same valve module4and/or valve units5of different valve modules4. In each case, it is those valve units5which are pneumatically connected to the same compressed air receiving space15which are to be denoted as interconnected valve units5. The valve units5which are pneumatically connected to the same compressed air receiving space15can also be denoted as a valve unit group. The pneumatically interconnected valve units5are expediently connected in parallel to one another.

In the shown example, the compressed air receiving space15of the first pneumatic consumer6ais connected via the first hose arrangement14to two working ports12which by way of example are assigned to both valve units5of the same valve module4-here of a first valve module4a. Furthermore, by way of example, the first compressed air receiving space15aof the third pneumatic consumer6cis pneumatically connected via the second hose arrangement14bto three working ports12which by way of example are assigned to valve units5of different valve modules4-here by way of example of a second valve module4b, of a third valve module4cand of a fourth valve module4d. Moreover, by way of example, the second compressed air receiving space15bof the third pneumatic consumer6cis pneumatically connected via the third hose arrangement14to three working ports12which by way of example are assigned to valve units5of different valve modules4-here by way of example of the second valve module4b, the third valve module4aand of the fourth valve module4d.

Expediently, each working part12is pneumatically connected maximally to a single respective compressed air receiving space15.

The first hose arrangement14aby way of example comprises two first hose sections38awhich are each connected to a respective working port12. The first hose arrangement14further comprises a second hose section38bwhich is connected to the two first hose sections38ain particular in a manner such that separately led part-flows are led together in the first hose sections38ainto a compressed air flow which flows in the second hose section38b. For example the first hose arrangement has a Y-shape.

The second hose arrangement14bby way of example comprises three first hose sections38awhich are each connected onto a respective working port12. The second hose arrangement14bfurther comprises a second hose section38bwhich is connected to the three first hose sections38a, in particular in a manner such that part-flows which are led separately in the first hose sections38aare led together into a compressed air flow which flows in the second hose section38b. The third hose arrangement14cis designed as the second hose arrangement14b.

By way of example, the second consumer6band the fourth consumer6dare connected to the valve arrangement2in a conventional manner-thus without connecting together several valve units5. By way of example, the compressed air receiving space15of the second consumer6bis pneumatically connected to (only) a single working port12via a single hose39. In a similar manner, the compressed air receiving spaces15a,15bof the fourth consumer6dare each pneumatically connected to in each case (only) a single working port12each via a respective single hose39.

Inasmuch as one refers to the valve units5, in particular interconnected valve units5in the subsequent explanations, what are particularly meant herewith are the valve units5which are pneumatically connected to the compressed air receiving space15of the first consumer6a. Furthermore, the subsequent explanations accordingly apply to the case in which more than two valve units5are interconnected, thus in which for example three valve units5are interconnected, as is the case with respect to the third consumer6c.

Preferably, the pneumatic system1comprises a control unit16which by way of example is part of the valve arrangement2. For example, the control unit16is arranged in a control section17of the valve arrangement2. The control section17is arranged for example on the carrier section36or part of the carrier section3. According to an alternative embodiment, the control unit16can also be provided separately from the valve arrangement2, for example as an external control. Furthermore, the control unit16can be implemented on the control device7. The control unit16is designed to generate control signals28for controlling the valve units5. In particular, the control unit16is designed to generate the control signals for controlling the valve units5such that by way of this the simultaneous pressurising or simultaneous exhausting is effected by way of the at least two (or three) interconnected valve units5.

Preferably, the control unit16comprises connection information which indicates that the at least two (or three) valve units5are interconnected. For example, it is stored in the connection information as to which valve units5are interconnected into a respective valve unit group. By way of example, the connection information indicates that the two valve units5a,5bof the first valve module4aare interconnected into a (first) valve unit group, that the second valve units5bof the second valve module4b, of the third valve module4cand of the fourth valve module4dare interconnected into a (second) valve unit group, and/or that the first valve units5aof the second valve module4b, of the third valve module4cand of the fourth valve module4dare interconnected into a (third) valve unit group.

Preferably, the control unit16is designed to take into account the connection information on generating the control signals28, in particular in a manner such that a pressurising or exhausting is effected by way of all valve units5which belong to the same valve unit group.

The control unit16is expediently designed to carry out at least one application and in the course of the application to generate the control signals28for the control of the interconnected valve units5. The application comprises for example a pressure closed-loop control function, a throttle function, a mass flow function and/or a servo positioning function.

For example, the control unit16implements a pressure closed-loop control application in order to closed-loop control the pressure in the respective compressed air receiving space to a pressure setpoint. By way of example, the control unit16implements the pressure closed-loop control application with respect to the first consumer6aand/or the second consumer6b. For example, the control unit16implements a cylinder application (in particular with servo positioning), in order to closed-loop control a respective piston of a respective drive cylinder to a position setpoint. By way of example, the control unit16implements the cylinder application with respect to the third consumer6cand/or the fourth consumer6d.

Preferably, the control unit16is designed, per application, to compute the control signals28for the interconnected valve units5which are assigned to the application, according to a computation regulation, wherein the computation regulation expediently comprises a rule for processing the sensor signals35of several sensor units18and/or a rule for distributing the compressed air throughput onto the interconnected valve units5.

FIG.3shows an exemplary design of a controller25. The controller25is in particular a closed-loop controller. For example, it is the control unit16which comprises the controller25, For example, the controller25is a program which is carried out by the control unit16. For example, the computation regulation which is mentioned above is realised by the controller25. The controller25is designed to generate one or more control signals28on the basis of a setpoint signal26and of an actual value signal27. The actual value signal27can also be denoted as a measurement value signal.

Each control signal28serves for controlling a respective valve unit5. Each control signal by way of example comprises a first valve control signal (for example a first control voltage) for controlling the respective first valve24aand a second valve control signal (for example a second control voltage) for controlling the respective second valve24b.

By way of example, the controller25comprises a pre-processing unit29which is designed to carry out a pre-processing of the setpoint signal26, in order to generate a pre-processed setpoint signal30. The pre-processing comprises for example a saturation, a gradient limitation and/or a filter.

By way of example, the controller25further comprises a controller unit31which in particular is designed as a pressure controller unit. The controller unit31is designed to generate a controller signal32on the basis of the pre-processed setpoint signal30and of the actual value signal27. For example, the controller unit31for generating the controller signal32carries out an error computation, a PI closed-loop control or a PID closed-loop control and/or an anti-windup.

By way of example, the controller25further comprises an actuation unit33which is designed to generate one or two (or three) control signals28for one or two (or three) control valve units5on the basis of the controller signal32. The actuation unit33in particular serves for controlling piezo-valves and can also be denoted as a piezo-actuation unit. The actuation unit33carries out for example a throughput correction and/or a piezo-compensation for generating the one or the two control signals28. Expediently, the actuation unit33comprises an output-splitter for generating two (or three) control signals28. Optionally, the actuating unit33permits a manual control.

By way of example, the controller25further comprises a measurement value pre-processing unit34which is designed to generate the actual value signal27on the basis of one or more sensor signals35. For example, the measurement value pre-processing unit34carries out a signal processing for generating the actual value signal27and/or comprises an observer.

As already mentioned above, the pneumatic system1preferably comprises a plurality of sensor units18. Each sensor unit18is expediently assigned to a respective valve unit5and/or serves for providing a respective sensor signal35. Preferably, the control unit16is designed, on the basis of one or more of the sensor signals35, to provide the actual value signal27and to generate the control signals28for the interconnected valve units5on the basis of the same actual value signal27, in particular on the basis of the same actual value of the actual value signal27. For example, the control unit16is designed to provide the actual value signal27by way of the control unit16selecting a sensor signal35from the sensor signals35and generating the actual value signal27, in particular the actual value, on the basis of the selected sensor signal35or by way of the control unit computing the actual value signal27, in particular the actual value, on the basis of the several sensor signals35. An example of the latter approach is shown inFIG.4.

FIG.4shows a block diagram of a control circuit of a closed-loop control which is expediently carried out by the pneumatic system1. The control circuit comprises a closed-loop control algorithm36which is designed, on the basis of the setpoint signal26and the actual value signal27, to generate several control signals28for the interconnected valve units5, for example a first control signal28afor one of the interconnected valve units5and a second control signal28bfor another of the interconnected valve units5. Expediently, the closed-loop control algorithm36generates a respective control signal28for each of the interconnected valve units5(of a valve unit group). The closed-loop control algorithm36is formed for example by the pre-processing unit29, the controller unit31and the actuation unit33. According to the respectively received control signal28, each of the interconnected valve units5outputs a respective pneumatic signal37to the consumer6, with which signal the compressed air receiving space15of the consumer6is pressurised or exhausted.

By way of example, the control circuit comprises a sensor signal processing unit40which in particular is designed to reconcile with one another the sensor signals35of several sensor units18which are assigned to interconnected valve units5of the same valve unit group, in particular to amalgamate these, for example by way of forming an average or by way of weighting according to the respective throughout, in order to generate the actual value signal27as a result. The sensor signal processing unit40is formed for example by the measurement value pre-processing unit34.

Alternatively, the sensor signal pre-processing unit40can be designed to select one of the sensor signals35of several sensor units18which are assigned to interconnected valve units5of the same valve unit group and as an actual value signal27to use the selected sensor signal35(and expediently not to use the non-selected sensor signals35, in particular not for the generation of the control signals28).

FIG.5shows an alternative approach, concerning which several control circuits are present—and specifically an individual control circuit for each valve unit5. An individual closed-loop control algorithm36is present for each valve unit5of a valve unit group and generates a respective control signal28only for this one valve unit5. Moreover, a respective actual value signal27is generated for each control algorithm36, by way of example by way of a respective sensor signal processing unit40, on the basis of a respective sensor signal35.

Different variants as to how the compressed air throughflow can be divided onto the interconnected valve units5are to be dealt with hereinafter.

The control unit16is preferably designed, in a first working region41, to control the interconnected valve units5with the control signals28in a manner such that the compressed air receiving space15is simultaneously pressurised or exhausted by way of both (or threc) interconnected valve units5, and in a second working region42to control the interconnected valve units5with the control signals28in a manner such that the compressed air receiving space15is effected by way of only one of the two (or three) interconnected valve units. The working regions41,42in particular are compressed air throughput regions, expediently related to the compressed air throughput of the compressed air flow which flows out of the compressed air receiving space15. The first working region41comprises larger throughputs than the second working region42. By way of example, the first working region41connects onto the second working region42in the direction of an increasing compressed air throughput. In particular, the two working regions41,42do not overlap.

FIG.6shows an example of the approach which is explained above. The throughput (of the compressed air flow which flows into or out of the compressed air receiving space15) is plotted on the horizontal axis. For example, the compressed air throughput which is plotted on the horizontal axis is that compressed air throughput which is demanded by the control unit16, in particular by an application which runs on the control unit16. The compressed air throughput which is plotted on the horizontal axis is also to be denoted as the demanded compressed air throughput. The respective control signal28a,28b(or the compressed air throughput which is provided by the respective valve unit5) is plotted on the vertical axis. The upper illustratory picture relates to one of the interconnected valve units and the lower illustratory picture to another of the interconnected valve units (of the same valve unit group). Starting from a throughput starting value (for example zero), the first control signal28a(or the compressed air throughput which is provided by the one valve element5) increases in the second working region42with an increasingly demanded compressed air throughput, by way of example monotonously, in particular strictly monotonously, preferably linearly. The second control signal28b(or the compressed air throughput which is provided by the other valve unit5) remains equal to zero in the second working region42. The second working region42ends and the first working region41begins, in a region in which the compressed air throughput of the one valve unit5(or the first control signal28a) reaches its maximum. The transition from the second working region42to the first working region41can lie precisely at the point in which the compressed air throughput of the one valve unit5(or the first control signal28a) reaches its maximum, or, alternatively, before this point. In the first working region41, the first control signal28a(or the compressed air throughput which is provided by the one valve unit5) remains constant with an increasingly demanded compressed air throughput, whereas the second control signal28b(or the compressed air throughput which is provided by the other valve unit5) starting from a throughput starting value (for example zero) rises with an increasingly demanded compressed air throughput, by way of example monotonously, in particular strictly monotonously, preferably linearly.

FIG.7shows an alternative approach, concerning which the demanded compressed air throughput is equally distributed onto the two control signals28a,28b, so that both control signals28a,28bhave the same course and rise in the same manner, by way of example linearly, given an increasing demanded compressed air throughput.

The control unit16is preferably designed to control the interconnected valve units5with the control signals28in a manner such that one of the interconnected valve units5exclusively provides a constant share of a compressed air throughput which occurs on pressurising and/or exhausting the compressed air receiving space15and another of the interconnected valve units5provides a changing share of the compressed air throughput. For example, the one valve unit5provides the constant share so that for this the first control signal28ais provided with a constant signal value, and the other valve unit5provides the changing share of the compressed air throughput, so that the second control signal28bis provided with a changing signal value for this.

Preferably, the control unit16is designed to carry out a detection procedure and in the course of the detection procedure to control the valve units5with the control signals28, in order by way of each valve unit5to carry out a respective pressurising and/or exhausting, and on the basis of sensor signals35of sensor units18assigned to the valve units5, said sensor signals being detected during each pressurising and/or exhausting, to determine which valve units5are pneumatically connected via the hose arrangement14to the same compressed air receiving space15and to register these valve units15as interconnected valve units5, in particular in the connection information. In this manner, the control unit16can carry out an automatic detection of the interconnected valve units5.

Alternatively or additionally to this, one can also manually input which valve units5are interconnected or which valve units5belong to the same valve unit group.

For example, the pneumatic system1comprises a user interface19via which a user can carry out a user input which specifies an assignment of a setpoint signal26to a valve unit5and or specifies which valve units5are interconnected. The user interface19by way of example is part of the user device. The user can expediently link the valve units5(or working ports12) with one another in the control unit16by way of him assigning the same setpoint signal26to several valve units, in particular by way of the user interface19. Alternatively to this, the user can directly specify which valve units5(or working ports12) are linked with one another, in particular by way of the user interface19, and to then optionally assign a setpoint signal to the linked valve units5(or working ports12).