Metering valve

Abstract

Metering valve (1) for supplying gas to a fuel cell, with a base body (10) in which an electromagnet (12) is arranged; and a nozzle (14) which is connected to the base body (10), wherein a first armature (16) for actuating a first closing element (18) is arranged in the nozzle (14), wherein the first closing element (18) is configured to open and close a first sealing seat (20) of the metering valve (1), wherein a second armature (24) is arranged in the nozzle (14) and is guided into the nozzle (14) by the base body (10) through a bore (22) formed in the nozzle (14) for actuating a second closing element (26), wherein the second closing element (26) is configured to open and close a second sealing seat (28) of the metering valve (1), wherein the first armature (16) and the second armature (24) can be actuated by the electromagnet (12),wherein the nozzle (14) has an inlet opening (30) for supplying gas to the metering valve (1) and an outlet opening (32) for discharging gas to the fuel cell, characterized in that the first sealing seat (20) and the second sealing seat (28) can be approached in parallel by a gas flow entering through the inlet opening (30) and can be opened synchronously.

Description

[0001] The invention relates to a metering valve for supplying gas to a fuel cell. State of the art

[0002] Fuel cell systems conventionally comprise a fuel cell having a cathode compartment and an anode compartment separated from the cathode compartment by a membrane, further comprising an anode gas source, a gas supply connected to the anode gas source and the anode compartment, an exhaust air line connected to the anode compartment, a cathode gas source, a gas supply connected to the cathode gas source and the cathode compartment, and an exhaust air line connected to the cathode compartment.

[0003] A dosing valve is conventionally arranged in the gas supply of the anode chamber.

[0004] DE 10 2013 226 820 A1 discloses a control unit which detects an operating state of the fuel cell and controls the metering valve depending on the operating status, i.e. in particular varies a flow cross-section or a pressure.

[0005] From WO 2014 / 132089 A1, a valve unit for regulating the flow of working fluid between a working chamber of a fluid working machine and both a first working fluid line and a second working fluid line is known.

[0006] A key requirement for the further development of the metering valve is to increase the pressure upstream of the metering valve, meaning the required closing spring force must be increased accordingly. As the spring force increases, the load on the sealing seat increases, leading to increased wear on the already critical seal. Furthermore, it is necessary to optimize the valve's opening characteristics. Disclosure of the invention

[0007] The present invention provides a metering valve for supplying gas to a fuel cell, comprising a base body in which an electromagnet is arranged, and a nozzle connected to the base body. A first armature for actuating a first closure element is arranged in the nozzle. The first closure element is designed to open and close a first sealing seat of the metering valve. A second armature is arranged in the nozzle and is guided from the base body through a bore formed in the nozzle into the nozzle and is designed to actuate a second closure element. The second closure element is designed to open and close a second sealing seat of the metering valve. The first armature and the second armature are actuable by the electromagnet. The nozzle has an inlet opening for supplying gas to the metering valve and an outlet opening for discharging gas to the fuel cell.and wherein the first sealing seat and the second sealing seat can be flowed against in parallel and opened synchronously by a gas stream entering through the inlet opening.,

[0008] One idea of ​​the present invention is to provide an optimized opening characteristic compared to a conventional single-stage opening of the metering valve by providing a first sealing seat and a second sealing seat, which can be flowed against in parallel by the gas flow entering through the inlet opening and opened synchronously. The first sealing seat and the second sealing seat both receive parallel flow, meaning the spaces are constantly connected via gaps and the same pressure prevails. Due to the flow from below, the metering valve opens with pressure support.

[0009] Advantageous embodiments and further developments emerge from the subclaims and from the description with reference to the figures.

[0010] According to a preferred development, the inlet opening of the nozzle for supplying gas to the metering valve is formed in the region of the second sealing seat, wherein the second sealing seat has a first bore fluidically communicating with the first closure element of the first sealing seat, and wherein the second sealing seat has a second bore fluidically communicating with the second closure element of the second sealing seat. Thus, the first sealing seat and the second sealing seat of the metering valve can advantageously be flowed against in parallel.

[0011] According to a further preferred development, a first air gap is formed between the first armature and a first housing element of the metering valve, and a second air gap is formed between the second armature and a magnetic core of the metering valve, wherein the first air gap has a smaller dimension than the second air gap. Thus, the first armature advantageously has a high magnetic force, which can be generated with a low drive current.

[0012] According to a further preferred development, when a control current is applied to a magnetic coil of the electromagnet, the first armature is configured to open the first sealing seat, and the second armature is configured to open the second sealing seat. The first armature can be placed against the second armature and is configured to move the second armature when the first armature moves. Thus, by at least opening the first sealing seat, pressure relief can be generated, and the second sealing seat can be opened with less force.

[0013] According to a further preferred development, the outlet opening of the nozzle for discharging gas to the fuel cell is formed in the cavity of the nozzle, and the first armature is formed by a plate armature and the second armature by a plunger armature. Since the gas mass flow is regulated by the second valve seat, the outlet opening of the nozzle can advantageously be arranged in the region of the second sealing seat.

[0014] According to a further preferred development, the first armature is resettable by a first spring element and the second armature by a second spring element, wherein the first spring element has a lower spring force than the second spring element. Due to the high magnetic force at low drive current of the first armature, a stronger spring element is required to reset the armature compared to the second armature, which requires a larger drive current. This advantageously allows for a higher preload for good sealing and a low spring stiffness for good control.

[0015] According to a further preferred development, the first closure element is formed by the first anchor or integrally with the first anchor, wherein a contact surface of the first closure element on the first sealing seat has a sealing element, which is preferably made of an elastomer material. Thus, a good seal of the sealing seat can be advantageously achieved.

[0016] According to a further preferred development, a residual air gap disk is arranged between the first armature and the first housing element of the metering valve to prevent the first armature from magnetically adhering to the first housing element. This advantageously ensures that the first armature is always arranged at a distance from the first housing element.

[0017] According to a further preferred development, a sleeve, preferably made of a non-magnetic material, is arranged between the second armature and the first housing element of the metering valve. The sleeve is designed to magnetically separate the magnetic core from the first housing element of the housing. By providing the sleeve, a magnetic separation of the magnetic core from the first housing element can thus be advantageously achieved.

[0018] According to a further preferred development, the sleeve is designed to hold a second housing element of the metering valve arranged adjacent to the first housing element of the housing, and wherein the first armature has an opening through which a projection of the second housing element of the housing extends. Thus, the second housing element of the housing can be advantageously held by the sleeve. The described designs and further training courses can be combined as desired.

[0019] Further possible embodiments, further developments and implementations of the invention also include combinations of features of the invention described previously or below with regard to the exemplary embodiments that are not explicitly mentioned. Short description of the drawings

[0020] The accompanying drawings are intended to provide a further understanding of embodiments of the invention. They illustrate embodiments and, in conjunction with the description, serve to explain principles and concepts of the invention.

[0021] Other embodiments and many of the aforementioned advantages will become apparent upon review of the drawings. The elements illustrated in the drawings are not necessarily drawn to scale.

[0022] They show: Fig. 1 is a cross-sectional view of a portion of a metering valve for supplying gas to a fuel cell according to a preferred embodiment of the invention; and Fig. 2 a sectional view AA of the Fig. 1 according to the preferred embodiment of the invention.

[0023] In the figures of the drawings, the same reference symbols designate the same or functionally equivalent elements, parts or components, unless otherwise stated.

[0024] Fig. 1 shows a cross-sectional view of a portion of a metering valve for supplying gas to a fuel cell according to a preferred embodiment of the invention.

[0025] The metering valve 1 for supplying gas to a fuel cell has a base body 10. An electromagnet 12 is arranged in the base body 10. The metering valve 1 further has a nozzle 14. The nozzle 14 is connected to the base body 10. A first armature 16 for actuating a first closure element 18 is arranged in the nozzle 14. The first closure element 18 is designed to open and close a first sealing seat 20 of the metering valve 1.

[0026] Furthermore, a second armature 24 is arranged in the nozzle 14, which is guided from the base body 10 through a bore 22 formed in the nozzle 14 into the nozzle 14 and is used to actuate a second closure element 26. The second closure element 26 is designed to open and close a second sealing seat 28 of the metering valve 1.

[0027] The first armature 16 and the second armature 24 are actuated by the electromagnet 12. The nozzle 14 has an inlet opening 30 for supplying gas to the metering valve 1 and an outlet opening 32 for discharging gas to the fuel cell. The first sealing seat 20 and the second sealing seat 28 can be subjected to a gas flow entering through the inlet opening 30 in parallel and opened synchronously.

[0028] The inlet opening 30 of the nozzle 14 for supplying gas to the metering valve 1 is formed in the region of the second sealing seat 28. The second sealing seat 28 has a first bore 34 that fluidically communicates with the first closure element 18 of the first sealing seat 20. The second sealing seat 28 further has a second bore 37 that fluidically communicates with the second closure element 26 of the second sealing seat 28.

[0029] A first air gap 38 is formed between the first armature 16 and a first housing element 36 of the metering valve 1. Furthermore, a second air gap 42 is formed between the second armature 24 and a magnetic core 40 of the metering valve 1. The first air gap 38 has a smaller dimension than the second air gap 42.

[0030] When a control current is applied to a magnetic coil 44 of the electromagnet 12, the first armature 16 is designed to open the first sealing seat 20 and the second armature 24 is designed to open the second sealing seat 28, wherein the first armature 16 can be placed against the second armature 24 and is designed to move the second armature 24 when the first armature 16 moves.

[0031] Due to its larger dimensions and its closer arrangement relative to the magnetic coil 44 of the electromagnet 12, the first armature 16 responds faster than the second armature 24 when the control current is applied to the magnetic coil 44 of the electromagnet 12. The first armature 16 thus carries the second armature 24 along with it during its movement, in that the first armature 16 initially makes contact with the second armature 24 and then moves it along with it during its movement. This results in a synchronous opening of the first sealing seat 20 and the second sealing seat 28.

[0032] The outlet opening 32 of the nozzle 14 for discharging gas to the fuel cell is formed in the cavity 46 of the nozzle 14. The first armature 16 is formed by a plate armature. The second armature 24 is formed by a plunger armature.

[0033] The first armature 16 is resettable by a first spring element 48. The second armature 24 is resettable by a second spring element 50. The first spring element 48 has a lower spring force than the second spring element 50.

[0034] In the present embodiment, the first closure element 18 is formed by the armature 16. Alternatively, the first closure element 18 can be formed integrally with the first armature 16, for example. A contact surface 52 of the first closure element 18 has a sealing element 54 at the first sealing seat. The sealing element 54 is preferably formed from an elastomer material. Likewise, the second closure element 26 of the second sealing seat 28 has a sealing element formed from a corresponding elastomer material.

[0035] A residual air gap disc 56 is arranged between the first armature 16 and the first housing element 36 of the metering valve 1. The residual air gap disc 56 serves to prevent the first armature 16 from magnetically adhering to the first housing element 36. The residual air gap disc 56 is made of plastic, for example.

[0036] A sleeve 58 made of a non-magnetic material is arranged between the second armature 24 and the first housing element 36 of the metering valve 1. The sleeve 58 is designed to magnetically separate the magnetic core 40 from the first housing element 36.

[0037] The sleeve 58 is designed to hold a second housing element 60 of the metering valve 1, which is arranged adjacent to the first housing element 36. The first armature 16 has an opening 62 through which a projection 64 of the second housing element 60 extends.

[0038] Fig. 2 shows a sectional view AA of the Fig. 1 according to the preferred embodiment of the invention.

[0039] The first armature 16 has an opening 62. A projection 64 of the second housing element 60 extends through the opening 62. The first armature 16 can thus advantageously be guided along the projection 64 of the second housing element 60.

[0040] Although the present invention has been described above using preferred embodiments, it is not limited thereto, but can be modified in a variety of ways. In particular, the invention can be changed or modified in a variety of ways without deviating from the essence of the invention.

[0041] For example, the shape, dimensions and / or properties of the components of the dosing valve can be modified according to the respective structural or design requirements.

Claims

[1] Dosing valve (1) for supplying gas to a fuel cell, comprising a base body (10) in which an electromagnet (12) is arranged;and a nozzle (14) which is connected to the base body (10), wherein a first armature (16) for actuating a first closure element (18) is arranged in the nozzle (14), wherein the first closure element (18) is designed to open and close a first sealing seat (20) of the metering valve (1), wherein a second armature (24) is arranged in the nozzle (14) and is guided from the base body (10) through a bore (22) formed in the nozzle (14) into the nozzle (14) for actuating a second closure element (26), wherein the second closure element (26) is designed to open and close a second sealing seat (28) of the metering valve (1), wherein the first armature (16) and the second armature (24) are actuable by the electromagnet (12), wherein the nozzle (14) has an inlet opening (30) for supplying gas to the metering valve (1) and an outlet opening (32) for discharging gas to the fuel cell; characterized bythat the first sealing seat (20) and the second sealing seat (28) can be flowed against in parallel and opened synchronously by a gas stream entering through the inlet opening (30). [2] Dosing valve according to claim 1, characterized by in that the inlet opening (30) of the nozzle (14) for supplying gas to the metering valve (1) is formed in the region of the second sealing seat (28), wherein the second sealing seat (28) has a first bore (34) fluidically communicating with the first closure element (18) of the first sealing seat (20), and wherein the second sealing seat (28) has a second bore (37) fluidically communicating with the second closure element (26) of the second sealing seat (28). [3] Dosing valve according to claim 1 or 2, characterized bythat a first air gap (38) is formed between the first armature (16) and a first housing element (36) of the metering valve (1), and a second air gap (42) is formed between the second armature (24) and a magnetic core (40) of the metering valve (1), wherein the first air gap (38) has a smaller dimension than the second air gap (42). [4] Dosing valve according to one of the preceding claims, characterized by that when a control current is applied to a magnetic coil (44) of the electromagnet (12), the first armature (16) is designed to open the first sealing seat (20), and the second armature (24) is designed to open the second sealing seat (28), wherein the first armature (16) can be placed against the second armature (24) and is designed to move the second armature (24) along with the movement of the first armature (16). [5] Dosing valve according to one of the preceding claims, characterized bythat the outlet opening (32) of the nozzle (14) for discharging gas to the fuel cell is formed in a cavity (46) of the nozzle (14), and wherein the first armature (16) is formed by a plate armature and the second armature (24) is formed by a plunger armature. [6] Dosing valve according to one of the preceding claims, characterized by that the first armature (16) can be reset by a first spring element (48) and the second armature (24) by a second spring element (50), wherein the first spring element (48) has a lower spring force than the second spring element (50). [7] Dosing valve according to one of the preceding claims, characterized by that the first closure element (18) is formed by the first anchor (16) or integrally with the first anchor (16), wherein a contact surface (52) of the first closure element (18) on the first sealing seat (20) has a sealing element (54) which is preferably formed from an elastomer material. [8] Dosing valve according to one of the preceding claims, characterized by that a residual air gap disc (56) is arranged between the first armature (16) and the first housing element (36) of the metering valve (1) to prevent magnetic adhesion of the first armature (16) to the first housing element (36). [9] Dosing valve according to one of the preceding claims, characterized by that a sleeve (58) preferably made of a non-magnetic material is arranged between the second armature (24) and the first housing element (36) of the metering valve (1), wherein the sleeve (58) is designed to magnetically separate the magnetic core (40) from the first housing element (36). [10] Dosing valve according to claim 9, characterized bythat the sleeve (58) is designed to hold a second housing element (60) of the metering valve (1) arranged adjacent to the first housing element (36), and wherein the first armature (16) has an opening (62) through which a projection (64) of the second housing element (60) extends. [11] Fuel cell arrangement with a metering valve according to one of claims 1 to 10.

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