CN110799784B

CN110799784B - Proportional valve for controlling a gaseous medium

Info

Publication number: CN110799784B
Application number: CN201880041944.XA
Authority: CN
Inventors: M·库尔茨
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2017-06-21
Filing date: 2018-04-25
Publication date: 2022-05-10
Anticipated expiration: 2038-04-25
Also published as: WO2018233911A1; DE102017210355A1; CN110799784A

Abstract

The invention relates to a proportional valve (1) for controlling a gaseous medium, in particular hydrogen, having a valve housing (2), wherein the valve housing (2) comprises a nozzle body (13). An inner chamber (90) is formed in the valve housing (2), wherein a closing element (16) is arranged in the inner chamber (90), wherein the closing element (16) releases or blocks at least one through-opening (17) at a valve seat (19) which is formed on the nozzle body (13). A solenoid armature device (25) which can be moved back and forth is arranged in the interior (90), wherein the solenoid armature device (25) is operatively connected to the closing element (16). Furthermore, a through-channel (12) is formed in the nozzle body (13), wherein the solenoid armature device (25) has a guide surface (11) in the nozzle body (13). Furthermore, the guide surface (11) together with the control edge (14) forms a slide valve (26) at a passage opening (27) of the through-passage (12), wherein, when the at least one through-opening (17) is closed, the solenoid armature device (25) closes the passage opening (27) of the through-passage (12) by means of the guide surface (11).

Description

Proportional valve for controlling a gaseous medium

Technical Field

The invention relates to a proportional valve for controlling a gaseous medium, in particular hydrogen, which is used, for example, in a vehicle having a fuel cell drive.

Background

DE 102012204565 a1 describes a proportional valve for controlling a gaseous medium, in particular hydrogen, wherein the proportional valve comprises a nozzle body, a closing element and an elastic sealing element. At least one through-opening is formed in the nozzle body, which can be released or closed at the valve seat by means of a closing element. The elastic sealing element here seals at the valve seat and has a recess with an inner wall region. In the closed state of the proportional valve, the inner wall region is pressurized with the pressure of the gaseous medium.

The proportional valves are distinguished in that, when they are used, only small pressure fluctuations occur in the anode path of the fuel cell and quiet operation can be ensured. In the normal operating region of a proportional valve, opening and closing processes often occur. Additional switching processes may also be required in order to optimize the scavenging process in the anode path of the fuel cell or to achieve an optimized operation of the ejector pump in the fuel cell assembly. Frequent opening and closing of the proportional valve can lead to wear at the valve seat, especially when the closing element is used together with a resilient sealing element. This in turn has an effect on the sealing of the entire proportional valve.

Disclosure of Invention

In contrast, the proportional valve according to the invention for controlling a gaseous medium, in particular hydrogen, has the following advantages: by separating the "sealing" and "metering" functions in the proportional valve, wear on the closure element is reduced despite frequent opening and closing or during part load operation of the proportional valve, thereby increasing the life of the entire proportional valve.

For this purpose, a proportional valve for controlling a gaseous medium, in particular hydrogen, has a valve housing. The valve housing includes a nozzle body. An inner chamber is formed in the valve housing, in which a closing element is arranged. Furthermore, the closing element releases or blocks at least one through-opening formed on a valve seat on the nozzle body. A solenoid armature device which can be moved back and forth is also arranged in the interior and is operatively connected to the closing element. A through-channel is formed in the nozzle body. Furthermore, in the nozzle body, the solenoid armature device has a guide surface. Furthermore, the guide surface forms a slide valve together with a control edge at the passage opening of the through-passage, wherein the solenoid armature device closes the passage opening of the through-passage by means of the guide surface when the at least one through-opening is closed.

By forming the slide valve at the through-passage, the metering function can be assumed by the slide valve, whereas the closing element is used only when fully closed and when open. The slide valve therefore also at least partially assumes the sealing function, since the flow of the gaseous medium is closed off by the slide valve at the passage opening of the through-passage. Wear at the closing element can therefore be significantly reduced, since the closing element is no longer required to be as strong, in particular in partial load operation of the proportional valve. It is particularly advantageous to arrange the jet pump on the proportional valve in the anode system of the fuel cell assembly. The mode of functioning and action of the ejector pump is limited at low flow rates. However, in order to achieve a flow rate which is effective for the ejector pump, a clock cycle is provided for the proportional valve in partial load operation. This results in an optimized function and an increased service life of the proportional valve and of the entire fuel cell assembly.

In a first advantageous embodiment of the invention, it is provided that the guide surface has a leakage, wherein the leakage is less than a minimum volume flow rate (mindestdurchflush rate) of the proportional valve, which minimum volume flow rate is predetermined by the system. Thus, the sealing on the guide surface is not absolute. However, the leakage is designed such that the resulting flow is less than the minimum flow necessary depending on the system. The minimum flow necessary depending on the system is obtained due to the flow that is active and necessary for the ejector pump. This ensures a sufficiently high seal at the guide surface and additionally contributes to an optimized functional manner of the slide valve.

In a further embodiment of the invention, it is advantageously provided that the through-channel and the channel opening of the through-channel are formed perpendicular to the longitudinal axis of the proportional valve, wherein the channel opening can be closed or partially released by means of a slide valve. Due to the vertical orientation of the through-passage, it can be completely closed by the slide valve. The closing and the partial release can cause an optimum metering of the gaseous medium in the proportional valve to be adapted to the respective operation.

In an advantageous development of the inventive concept, the solenoid armature device comprises a solenoid armature and a connecting element, wherein the guide surface is formed on the connecting element, which is preferably cylindrical. Advantageously, the connecting element comprises a pin-shaped section and a piston-shaped section, wherein the guide surface is formed on the piston-shaped section. In an advantageous embodiment, the diameter of the piston-shaped section is greater than the diameter of the pin-shaped section. This results in a space-saving and stable construction.

In a further embodiment of the invention, it is advantageously provided that at least one through-channel is formed in the piston-shaped section, wherein the piston-shaped section divides the interior space into a connection chamber and a magnet armature chamber. Advantageously, the connecting chamber is delimited by the piston-shaped section of the connecting element and the closing element. By means of the through-passage, a pressure equalization is established between the connection chamber and the magnet armature chamber, so that an optimized functional mode of the slide valve is ensured.

In an advantageous embodiment, it is provided that the inner chamber comprises a spring chamber in which a first spring is arranged, wherein the first spring exerts a force on the solenoid armature device in the direction of the through-opening. In this way, when the proportional valve is closed, it is ensured that the closing element closes the through-opening and the slide valve closes the through-passage, so that no gaseous medium can flow through the proportional valve.

In a further embodiment of the invention, it is advantageously provided that an annular element is arranged on the nozzle body, on which annular element the second spring is supported and exerts a force on the closing element in the direction of the solenoid armature device. The opening process of the proportional valve is facilitated by the use of said second spring.

In an advantageous embodiment, an elastic sealing element is arranged between the closing element and the valve seat, as a result of which the tightness at the closing element and thus at the valve seat is improved.

In a further advantageous embodiment, a magnet arrangement is arranged in the valve housing, wherein the magnet arrangement comprises an electromagnetic coil and a magnet core, by means of which the magnet armature device can be moved to and fro.

Preferably, the described proportional valve is adapted in a fuel cell assembly for controlling the delivery of hydrogen to the anode region of a fuel cell. The advantage is that the pressure fluctuations in the anode path are small and the operation is quiet.

Drawings

In the drawing, an exemplary embodiment of a proportional valve according to the invention is shown, which is used to control the gas supply, in particular the hydrogen supply, to a fuel cell. The attached drawings are as follows:

fig. 1 shows a first exemplary embodiment of a proportional valve according to the invention with a slide valve in longitudinal section.

Fig. 2a shows the embodiment of fig. 1 in a closed state.

Fig. 2b shows the embodiment of fig. 1 with the proportional valve open.

Fig. 2c shows the embodiment of fig. 1 in an open state.

Fig. 3 shows a further embodiment of the proportional valve according to the invention with a slide valve in longitudinal section.

The members having the same function are denoted by the same reference numerals.

Detailed Description

Fig. 1 shows a first exemplary embodiment of a proportional valve 1 according to the invention in longitudinal section. The proportional valve 1 has a valve housing 2, wherein the valve housing 2 comprises a retaining body 3 and a nozzle body 13, which are connected to one another in an airtight manner. A magnet arrangement 24 is arranged in the proportional valve 1, wherein the magnet arrangement 24 comprises an electromagnetic coil 23 and a magnet core 7. Furthermore, an interior chamber 90 is formed in the valve housing 2, in which the solenoid armature device 25 is arranged so as to be able to move back and forth. The solenoid armature device 25 comprises a solenoid armature 8 and a connecting element 10, wherein the connecting element 10 is received in a recess 29 of the solenoid armature 8 and is thus fixedly connected to the solenoid armature 8, for example by welding or by crimping. The magnet armature 8 is designed as a plug-in armature and is received in the magnet core 7. The connecting element 10 is received in the recess 6 of the core 7 and guided therein.

The connecting element 10 is cylindrical in shape and has a pin-shaped section 1000 and a piston-shaped section 100. Here, the diameter of the piston-shaped section 100 is greater than the diameter of the pin-shaped section 1000. The fixed connection of the connecting element 10 to the magnet armature 8 is formed on this pin-shaped section 1000.

The valve housing 2 and the magnet core 7 delimit a spring chamber 92 which forms part of the interior 90. In the spring chamber 92, a spring 4 is arranged, which is supported between the valve housing 2 and the disk-shaped end 5 of the connecting element 10 and exerts a force on the solenoid armature device 25 in the direction of the nozzle body 13. Additionally, the valve housing 2, the magnet core 7 and the connecting element 10 divide the interior 90 into a magnet armature chamber 91, in which the magnet armature 8 is arranged.

In the nozzle body 13, a through-channel 12 is formed perpendicular to the longitudinal axis 28 of the proportional valve 1, so that the inner chamber 90 can be filled with a gaseous medium, for example hydrogen. The piston-shaped section 100 has a guide surface 11 on which the piston-shaped section 100 is guided in the nozzle body 13 at the passage opening 27 of the through-passage 12. The guide surface 11 together with the control edge 14 at the passage opening 27 forms a slide valve 26. With the proportional valve closed, the piston-shaped section 100 closes the passage opening 27 by means of the guide surface 11 and thus blocks the inflow of gaseous medium into the interior 90 of the proportional valve 1. The guide surface 11 has a leakage, the resulting volume flow rate being less than the minimum volume flow rate required depending on the system. For example, the minimum volume flow rate is obtained on the basis of the flow speed which is effective and necessary for the ejector pump connected downstream in the anode system of the fuel cell assembly, whereby an optimized functional manner can be ensured.

In the interior 90, there is also arranged a closing element 16 with a disk-shaped elastic sealing element 18, which in the closed state of the proportional valve 1 rests against a valve seat 19 of the nozzle body 13 and thereby closes a through-opening 17 formed in the nozzle body 13, through which the gaseous medium can flow out of the proportional valve 1. In this case, the elastic sealing element 18 is fixedly connected to the closing element 16. Furthermore, the closing element 16 is operatively connected to a solenoid armature device 25. By means of the spring 4, the connecting element 10 rests with its pin-shaped section 1000 directly on the closing element 16.

The valve housing 2, the connecting element 10 and the closing element 16 divide the interior chamber 90 into a connecting chamber 15. The connection chamber 15 can be connected to the outflow region 21 via the through-opening 17. In the outflow region 21, a further spring 22 is arranged, which on the one hand bears against the annular element 20 formed on the nozzle body 13 and on the other hand bears against the closing element 16. The force of the further spring 22 is in the opposite direction to the force of the spring 4 in the spring chamber 92, wherein the combined force of the two springs 4, 22 together presses the closing element 16 against the valve seat 19, closes the through-opening 17 and fluidly seals the connection chamber 15 from the outflow region 21.

The connection chamber 15 is connected to the solenoid armature chamber 91 via two through channels 101 arranged parallel to the longitudinal axis 28, wherein the through channels 101 are formed in the piston-shaped section 100 for pressure compensation.

Functional mode of the first embodiment:

fig. 2a shows the proportional valve 1 of fig. 1 in the closed state. In the case of deenergization of the electromagnetic coil 23, the closing element 16 is pressed by the combined closing force of the springs 4, 22 against the valve seat 19 by means of the solenoid armature device 25, so that the through-opening 17 is blocked and no gaseous medium can flow out of the proportional valve 1.

Fig. 2b shows the exemplary embodiment of fig. 1 with an energized electromagnetic coil 23. When the electromagnetic coil 23 is energized, a magnetic force is generated on the magnet armature 8, which is in the opposite direction to the resultant closing force of the springs 4, 22. If this magnetic force exceeds the resulting closing force of the springs 4, 22, the solenoid armature device 25 moves in the direction of the spring 4. The closing element 16 immediately follows the magnet armature device 25 and is lifted from the valve seat 19 without relative movement due to the spring 22. The gas flow from the connection chamber 15 via the through-opening 17 into the outflow region 21 is released.

Fig. 2b shows the smallest possible flow through the through-opening 17 with the proportional valve 1 partially open, wherein the valve seat 19 has been released here, whereas the passage opening 27 of the through-passage 12 has not yet been released by the slide valve 26. In this case, the cover length l at the control edge 14 of the passage opening 27 is selected to be as small as possible in order to maintain the maximum stroke of the magnet armature device 25 and thus to keep the necessary magnetic force as small as possible.

The stroke of the closing element 16 can be set by the level of the current intensity on the solenoid 23. The higher the current on the solenoid 23, the greater the stroke of the closing element 16 and the greater the gas flow in the proportional valve 1, since the force of the springs 4, 22 is related to the stroke. From the determined stroke of the closing element 16, the passage opening 27 is also released by the slide valve 26 and the gas flow through the proportional valve 1 is released. If the current strength on the solenoid 23 is reduced, the stroke of the closing element 16 is also reduced, so that the gas flow through the spool 26 is throttled.

Fig. 2c shows the exemplary embodiment of fig. 1 in the case of a maximum opening stroke. The solenoid armature device 25 and the closing element 16 have reached their maximum stroke, so that a maximum flow through the proportional valve 1 is achieved. In addition to the through-opening 17, the through-channel 12 is now also maximally released by the slide valve 26.

If the current to the electromagnetic coil 23 is interrupted, the magnetic force acting on the magnet armature 8 is reduced, so that the force acting on the closing element 16 is reduced by means of the connecting element 10. The magnet armature device 25 and the closing element 16 are moved in the direction of the through-opening 17, wherein the closing element 16 is sealed at the valve seat 19 by means of the elastic sealing element 18. The gas flow in the proportional valve 1 is interrupted.

Fig. 3 shows a further exemplary embodiment of a proportional valve 1 according to the invention in longitudinal section. Components having the same function are denoted by the same reference numerals as in fig. 1. In this embodiment, the direction of flow of the gaseous medium through the proportional valve 1 is reversed. Furthermore, the closing element 16 is arranged such that, when the proportional valve 1 is opened, the closing element 16 opens in the direction away from the magnet arrangement 24. That is, the resultant force direction and the magnetic force direction of the springs 4, 22 are opposite compared to the first embodiment.

In addition to the closing element 16, the control valve 26 also opens in the same direction as the closing element 16 and is therefore directed oppositely compared to the first embodiment. This results in that, when the proportional valve 1 is open, gaseous medium from the connection chamber 15 enters the outflow region 21 and thus the through-channel 12 via the through-channel 101. In a further embodiment, the through-channel 101 is therefore also configured to be larger than in the first embodiment, in order not to throttle the maximum possible volume flow rate through the proportional valve 1.

Furthermore, the connecting element 10 is additionally received in a further guide 30 with a seal 31 on the valve housing 2 and guided therein.

The principle functional manner of this further embodiment is the same as that of the first embodiment.

The proportional valve 1 of the present invention may be used, for example, in a fuel cell assembly. By means of the proportional valve 1, hydrogen can be fed from the tank to the anode region of the fuel cell. Depending on the level of the current at the solenoid 23 of the proportional valve 1, by which the stroke of the closing element 16 and thus of the slide valve 26 is actuated, the flow cross section of the through-opening 17 is changed by the slide valve 26 in such a way that the gas flow to the fuel cell is continuously adjusted as required.

The proportional valve 1 for controlling a gaseous medium therefore has the following advantages: the supply of the first gaseous medium and the metering of hydrogen into the anode region of the fuel cell can be carried out substantially more precisely by electrically controlling the flow cross section of the through-openings 17 while simultaneously regulating the anode pressure. The operational safety and the durability of the connected fuel cell are thereby significantly improved, since the hydrogen is always transported in a superstoichiometric proportion. Furthermore, subsequent losses, for example damage to a downstream catalyst, can also be prevented.

Claims

1. Proportional valve (1) for controlling a gaseous medium, having a valve housing (2), wherein the valve housing (2) comprises a nozzle body (13), wherein an inner chamber (90) is formed in the valve housing (2), wherein a closing element (16) is arranged in the inner chamber (90), wherein the closing element (16) releases or blocks at least one through-opening (17) formed on a valve seat (19) on the nozzle body (13), wherein a reciprocally movable solenoid armature device (25) is arranged in the inner chamber (90), wherein the solenoid armature device (25) is in operative connection with the closing element (16), wherein a through-passage (12) is formed in the nozzle body (13), wherein the solenoid armature device (25) has a guide surface (11) in the nozzle body (13), characterized in that the guide surface (11) forms a slide valve (26) together with a control edge (14) at a passage opening (27) of the through-passage (12), wherein, when the at least one through-opening (17) is closed, the solenoid armature device (25) closes the passage opening (27) of the through-passage (12) by means of the guide surface (11), wherein the solenoid armature device (25) comprises a solenoid armature (8) and a connecting element (10), wherein the guide surface (11) is formed on the connecting element (10), wherein the connecting element (10) comprises a pin-shaped section (1000) and a piston-shaped section (100), wherein the guide surface (11) is formed on the piston-shaped section (100).

2. Proportional valve (1) for controlling a gaseous medium according to claim 1, characterized in that the guide surface (11) has a leakage, wherein the leakage is smaller than a minimum volume flow rate of the proportional valve (1), which is systematically predetermined.

3. Proportional valve (1) for controlling a gaseous medium according to claim 1 or 2, characterized in that the through-channel (12) and the channel opening (27) of the through-channel (12) are configured perpendicular to the longitudinal axis (28) of the proportional valve (1), wherein the channel opening (27) can be closed or partially released by means of the slide valve (26).

4. Proportional valve (1) for controlling a gaseous medium according to claim 1 or 2, characterized in that the diameter of the piston-shaped section (100) is larger than the diameter of the pin-shaped section (1000).

5. Proportional valve (1) for controlling a gaseous medium according to claim 1 or 2, characterized in that at least one through-channel (101) is configured in the piston-shaped section (100), wherein the piston-shaped section (100) divides the inner chamber (90) into a connecting chamber (15) and a solenoid armature chamber (91).

6. Proportional valve (1) for controlling a gaseous medium according to claim 5, characterized in that the connecting chamber (15) is delimited by a piston-shaped section (100) of the connecting element (10) and the closing element (16).

7. Proportional valve (1) for controlling a gaseous medium according to claim 1, 2 or 6, characterized in that the inner chamber (90) comprises a spring chamber (92), in which spring chamber (92) a first spring (4) is arranged, wherein the first spring (4) exerts a force on the solenoid armature device (25) in a direction towards the through opening (17).

8. Proportional valve (1) for controlling a gaseous medium according to claim 1, 2 or 6, characterized in that an annular element (20) is arranged on the nozzle body (13), a second spring (22) being supported on the annular element (20) and exerting a force on the closing element (16) in the direction of the solenoid armature device (25).

9. Proportional valve (1) for controlling a gaseous medium according to claim 1, 2 or 6, characterized in that an elastic sealing element (18) is arranged between the closing element (16) and the valve seat (19).

10. Proportional valve (1) for controlling a gaseous medium according to claim 1, 2 or 6, characterized in that a magnet arrangement (24) is arranged in the valve housing (2), wherein the magnet arrangement (24) comprises an electromagnetic coil (23) and a magnetic core (7) by means of which the electromagnetic armature device (25) is reciprocatable.

11. Proportional valve (1) for controlling a gaseous medium according to claim 1 or 2 or 6, characterized in that the gaseous medium is hydrogen.

12. A fuel cell assembly having a proportional valve (1) according to any of the preceding claims 1 to 11 for controlling the delivery of hydrogen to a fuel cell.