Pneumatic valve device

Abstract

A pneumatic valve arrangement (10) is proposed comprising a valve terminal (12) and at least two process valves (16), the valve terminal comprising at least two solenoid valves (14), the process valves (16) each comprising a working piston (24) defining a pressure chamber (26), the solenoid valves (14) each being arranged to open or close a flow path from a pressure source (19) to the associated process valve (16), the pressure chamber (26) is configured to apply a working medium to the pressure chamber (26) of the associated process valve (16) to open and / or close the process valve (16). Each process valve (16) comprises a position measurement system (36) arranged to continuously detect an open position of the process valve (16). The valve terminal (12) comprises a control unit (30) which is communicatively connected to the position measuring system (36) of the at least two process valves (16) via a single digital communication interface (48) arranged on the valve terminal (12).

Description

Technical Field

[0001] The present invention relates to a pneumatic valve arrangement having a valve island. The valve island comprises at least two solenoid valves. Furthermore, the pneumatic valve arrangement comprises at least two process valves. The process valves are driven, in particular, by the solenoid valves, since switching fluid is conveyed from the solenoid valves to the process valves. Background Art

[0002] Up to 32 process valves can be actuated using a single valve island. In known pneumatic valve arrangements, each process valve has a sensor, such as an inductive proximity switch, mechanical contact, or capacitive proximity switch, that is suitable for detecting the upper and lower positions of the respective process valve, i.e., the fully open or fully closed position of the process valve. Each process valve is connected to the valve island, in particular to its control unit, via two electronic lines. When a process valve reaches the upper or lower switching position, a signal is transmitted via the electronic lines to the control unit.

[0003] Wires are also required for voltage supply and grounding.

[0004] Therefore, such a pneumatic valve device has a large number of pipelines, which results in a high installation workload and makes assembly and maintenance of the pneumatic valve device more difficult. Summary of the Invention

[0005] It is therefore an object of the present invention to provide a pneumatic valve arrangement comprising a valve terminal and a plurality of process valves, wherein the setup effort is reduced.

[0006] According to the present invention, this object is achieved by a pneumatic valve arrangement comprising a valve island and at least two process valves. The valve island includes at least two solenoid valves, each of the process valves including a working piston delimiting a pressure chamber, and each solenoid valve being configured to open or close a flow path from a pressure source to an associated process valve to apply a working medium to the pressure chamber of the associated process valve, thereby opening and / or closing the process valve. Each process valve includes a position measurement system configured to continuously detect the open position of the process valve. The valve island includes a control unit that is communicatively connected to the position measurement systems of the at least two process valves via a single digital communication interface disposed on the valve island.

[0007] The advantage of the pneumatic valve arrangement according to the invention is that, since the signal transmission from the valve terminal to the process valve takes place via a single communication interface, the setup effort and complexity of the pneumatic valve arrangement are significantly reduced compared to known solutions.

[0008] Furthermore, compared to known solutions, communication between the valve terminal and the process valve is possible in both directions, which enables expanded functionality. For example, various functions such as auto-tuning and further control functions can be implemented.

[0009] Since the position measuring system is configured to continuously detect the open position of the process valve, it is possible to detect the valve stroke and draw conclusions about seal wear.

[0010] The communication interface is, for example, a bus interface, IO-Link or a Single Pair Ethernet (SPE) interface.

[0011] Preferably, the process valve is a pneumatic valve, and the working medium is therefore compressed air.

[0012] The valve island preferably comprises a carrier plate on which the solenoid valves are arranged. This also contributes to a compact structure of the pneumatic valve device.

[0013] According to one embodiment, the position measuring system is configured to detect the position of the working piston. The position of the working piston reflects the degree of opening of the process valve, so that the open position of the process valve can be reliably determined based on the position of the working piston.

[0014] Each process valve can include a monitoring unit in which the data measured by the position measuring system is recorded. The control unit of the valve island is communicatively connected to the monitoring unit via a digital communication interface. This allows a simple communication connection between the control unit of the valve island and the position measuring system, for example via a suitable communication interface on the process valve connected to the monitoring unit.

[0015] For example, each process valve includes a pressure sensor that is connected to a monitoring unit. The data recorded by the position measurement system and the pressure sensor can thus be combined in the monitoring unit and transmitted to the control unit of the valve terminal. This facilitates a simple electronic design of the pneumatic valve arrangement.

[0016] The pressure sensor measures, in particular, the pressure in the pressure chamber.

[0017] Based on the value measured by the pressure sensor, further functions can be implemented in the pneumatic valve arrangement.

[0018] For example, the control unit is configured to determine the pressure required to fully open the process valve based on the valve position detected by the position measurement system and the pressure detected by the pressure sensor. This reduces compressed air consumption in the pneumatic valve arrangement. Specifically, once the pressure required to fully open the process valve is reached, the compressed air supply to the pressure chamber is stopped, even if the working piston has not yet fully moved to the open position. Furthermore, the speed of the working piston toward its end position can be reduced by appropriately controlling the compressed air supply, thereby enabling a soft-closing function.

[0019] Furthermore, the control unit can be configured to infer a leak based on the pressure measured in the pressure chamber, for example, if there is no corresponding increase in pressure when the working medium is supplied to the pressure chamber. Such a leak could occur in the valve drive of the process valve or in the pneumatic line between the valve terminal and the process valve. This leak detection increases process safety.

[0020] Furthermore, the control unit can calculate the consumption of the working medium based on the measured pressure.

[0021] Each process valve can include a light signal unit, and the monitoring unit can be configured to activate the light signal unit to visualize the valve status. For example, it is possible to see which process valve is connected to which solenoid valve on the process valve and valve island. Faults can also be visualized.

[0022] Starting from the communication interface of the valve terminal, a single main cable can be extended to the process valve, and slave cables can be branched from the main cable to the process valve. This makes the process valve easy to connect.

[0023] The secondary cable is electrically connected to the primary cable, for example, via a T-shaped plug. The T-shaped plug makes branching off the primary cable particularly easy. In addition, such a plug is available as a standard component at low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Other advantages and features of the present invention will become apparent from the following description and with reference to the accompanying drawings, in which:

[0025] Figure 1 shows a pneumatic valve device according to the present invention, and

[0026] Figure 2 A process valve is shown. DETAILED DESCRIPTION

[0027] Figure 1 A pneumatic valve arrangement 10 is shown, which comprises a valve terminal 12 with a plurality of solenoid valves 14 and a plurality of process valves 16 .

[0028] Typically, each solenoid valve 14 has one process valve 16 assigned to it. However, for the sake of clarity, Figure 1 Only four process valves 16 are shown.

[0029] The solenoid valve 14 is arranged on a carrier 18. The carrier 18 is typically a fluid plate having a plurality of fluid tubes formed therein, however, for simplicity these fluid tubes are not shown in the drawings.

[0030] A fluid line extends from the pressure source 19 via a corresponding solenoid valve 14 to the fluid connection 20 , so that working medium can be provided at the fluid connection 20 depending on the switching position of the solenoid valve 14 .

[0031] The process valve 16 is connected to the valve island 12 , more specifically to the fluid connection 20 , via a fluid line 22 , so that the process valve 16 can be actuated by the solenoid valve 14 .

[0032] Also like Figure 2 As shown, each process valve 16 includes a working piston 24 which delimits a pressure chamber 26 .

[0033] The working piston 24 is connected to a valve closing element 25 which, in the closed state of the process valve 16 , rests on a valve seat.

[0034] A spring 28, which pushes the piston into the normally closed position, is arranged on the side of the working piston 24 facing away from the pressure chamber 26. In an alternative embodiment, the spring 28 can be arranged such that the working piston 24 is pushed into the normally open position.

[0035] The solenoid valves 14 are each configured to open or close a flow path from a pressure source 19 to an associated process valve 16 to apply working medium to a pressure chamber 26 of the associated process valve 16 to open the process valve 16 or, in the case of a normally open process valve 16 , to close the process valve 16 .

[0036] Furthermore, the valve island 12 comprises a control unit 30 which is configured to drive the solenoid valve 14 in order to control the supply of working medium to the pressure chamber 26 .

[0037] Each process valve 16 includes a drive unit 32 and an electronic chamber 34 mounted on the drive unit 32. The drive unit 32 includes a working piston 24 and a spring 28, and various electronic components of the process valve 16 are accommodated in the electronic chamber 34, such as Figure 2 shown.

[0038] Each process valve 16 comprises a position measuring system 36 (see Figure 2 ), the position measurement system is configured to continuously detect the opening position of the process valve 16 in order to determine the valve position of the corresponding process valve 16 .

[0039] More specifically, the position measurement system 36 is configured to detect the position of the working piston 24 .

[0040] like Figure 2 As shown, this can be achieved by a tappet 38 which is fastened to the working piston 24 and projects into the electronics chamber 34 of the process valve 16 .

[0041] Position measuring system 36 comprises, for example, a sensor 40 , in particular a Hall sensor.

[0042] In an alternative exemplary embodiment, the sensor 40 can be accommodated in the drive unit 32 of the process valve 16 and directly detect the position of the working piston 24 .

[0043] Each process valve 16 further comprises a monitoring unit 42 , which is also accommodated in the electronics chamber 34 of the process valve 16 .

[0044] The data measured by position measurement system 36 are recorded in monitoring unit 42 .

[0045] Each process valve further comprises a pressure sensor 44 which is arranged to measure the pressure in the pressure chamber 26 .

[0046] A pressure sensor 44 is also connected in a signal manner to the monitoring unit 42 .

[0047] The measured values ​​of position measuring system 36 and the measured values ​​of pressure sensor 44 are therefore combined in monitoring system 42 .

[0048] Furthermore, a light signal unit 46 is arranged in the electronics chamber 34 , which is visible from outside the process valve 16 .

[0049] The monitoring unit 42 is arranged to drive a light signal unit 46 to visualize the valve status.

[0050] The signaling unit 46 preferably comprises an LED.

[0051] The control unit 30 is communicatively connected to the position measurement system 36 of the process valve 16 via a single digital communication interface 48 arranged on the valve island 12 (see Figure 1 ).

[0052] The valve island 12 can be connected to a central control device via a further communication interface 49 .

[0053] The process valve 16 has a suitable communication interface 50 .

[0054] Starting from the communication interface 48 of the valve terminal 12 , a single main cable 52 extends to the process valve 16 , from which a secondary cable 54 branches off to the process valve 16 .

[0055] The main cable 52 is connected via a standard plug to the communication interface 48 of the valve island 12. Similarly, the slave cable 54 is connected via a standard plug to the communication interface 50 of the process valve 16.

[0056] The slave cable 54 is electrically connected to the main cable 52 via a T-plug 56 .

[0057] The main cable 52 is, in particular, a communication cable, via which information can be exchanged bidirectionally between the process valve 16 and the valve island 12 .

[0058] The communication interface 50 of the process valve 16 is connected to the monitoring unit 42 . This means that all information exchanged between the process valve 16 and the control unit 30 is exchanged via the monitoring unit 42 .

[0059] Therefore, various functions can be realized in the pneumatic valve device 10 .

[0060] For example, the control unit 30 may be configured to determine the pressure required to fully open the process valve 16 based on the valve position detected by the position measurement system 36 and the pressure detected by the pressure sensor 44 .

[0061] Furthermore, the control unit 30 may be arranged to infer a leak based on the pressure measured in the pressure chamber 26 .

[0062] Furthermore, the control unit 30 can infer seal wear and drive or stuffing box wear based on the end positions detected by the position measurement system 36 .

[0063] Furthermore, the control unit 30 can transmit information to the monitoring unit 42 , which information can be visualized on the signaling unit 46 .

[0064] For example, it is conceivable that the monitoring unit 42 drives the signal unit 46 such that the signal unit 46 flashes when the control unit 30 detects a fault (eg a leak).

[0065] Furthermore, wear of the process valve 16 can be signaled via the signaling unit 46 .

[0066] Furthermore, the control unit 30 can determine the operating time of the working piston 24 , ie the time required for the working piston to move from an end position into the opposite end position, based on the values ​​detected by the position measuring system 36 .

Claims

1. A pneumatic valve arrangement (10), comprising a valve island (12) and at least two process valves (16), the valve island (12) comprising at least two solenoid valves (14), the process valves (16) each comprising a working piston (24) delimiting a pressure chamber (26), the solenoid valves (14) each being arranged to open or close a flow path from a pressure source (19) to the associated process valve (16) in order to apply a working medium to the pressure chamber (26) of the associated process valve (16), thereby opening and / or closing the process valve (16), Each process valve (16) comprises a position measurement system (36) which is arranged to continuously detect the open position of the process valve (16), and The valve island (12) comprises a control unit (30) which is communicatively connected to the position measurement systems (36) of at least two process valves (16) via a single digital communication interface (48) arranged on the valve island (12).

2. The pneumatic valve device (10) according to claim 1, characterized in that: The position measuring system (36) is configured to detect the position of the working piston (24).

3. The pneumatic valve device (10) according to claim 1, characterized in that: Each process valve comprises a monitoring unit (42) in which the data measured by the position measuring system (36) are recorded, and to which the control unit (30) of the valve island (12) is communicatively connected via the digital communication interface (48).

4. The pneumatic valve device (10) according to claim 3, characterized in that: Each process valve (16) comprises a pressure sensor (44) which is connected to the monitoring unit (42) in a signal-wise manner.

5. The pneumatic valve device (10) according to claim 4, characterized in that: The control unit (30) is configured to determine a pressure required to fully open the process valve (16) based on the valve position detected by the position measurement system (36) and the pressure detected by the pressure sensor (44).

6. The pneumatic valve device (10) according to claim 4, characterized in that: The control unit (30) is arranged to infer a leak based on the pressure measured in the pressure chamber (26).

7. The pneumatic valve device (10) according to claim 3, characterized in that: Each process valve (16) comprises a light signal unit (46), and the monitoring unit (42) is arranged to drive the light signal unit (46) to visualize the valve state.

8. The pneumatic valve device (10) according to claim 1, characterized in that: Starting from the communication interface (48) of the valve island (12), a single main cable (52) extends to the process valve (16), and a secondary cable (54) branches off from the main cable (52) to the process valve (16).

9. The pneumatic valve device (10) according to claim 8, characterized in that: The secondary cable (54) is electrically connected to the primary cable (52) by means of a T-plug (56).

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