Separator leak inspection device

Abstract

To provide a technique for accurately detecting whether or not a pin hole exists in a separator.SOLUTION: A leak inspection device of a separator for fuel cell comprises: a pair of jigs which sandwiches the separator; a rubber-made seal member which is provided in one of the pair of jigs, and forms a sealed space between one of the pair of jigs and the separator by contacting the separator; a gas supply unit which supplies gas to the sealed space; and a pressure measuring unit which monitors the pressure in the sealed space. The seal member includes a seal part for manifold hole which is arranged along the periphery of a manifold hole and contacts over a plurality of grooves. The seal part for manifold hole has the rectangular cross-sectional shape in the unloaded condition and has the rubber hardness of 40-80 degrees.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present specification relates to a leak inspection device for a separator for a fuel cell. [Background technology]

[0002] A fuel cell is constructed by stacking a plurality of fuel cell units. Each fuel cell unit includes a pair of separators (i.e., an anode-side separator and a cathode-side separator), a membrane electrode assembly (MEA), an anode-side gas diffusion layer, and a cathode-side gas diffusion layer.

[0003] The separators are provided with manifold holes for supplying or discharging fluids such as anode gas, cathode gas, and cooling medium. When a plurality of fuel cells are stacked, the manifold holes are connected in series to form a connecting flow path. In each fuel cell, the various fluids described above are supplied from the connecting flow path or discharged to the connecting flow path. Each separator is provided with a gasket, for example, surrounding the manifold hole to prevent fluids from leaking from the connecting flow path.

[0004] Fuel cell separators are required to be free of pinholes. In this regard, Patent Document 1 describes an inspection device for fuel cell separators. This inspection device includes a light projecting unit that irradiates light toward one side of the separator, and a light receiving unit that detects the light that has passed through the pinholes in the separator on the other side of the separator. With this configuration, it is possible to inspect whether or not there are pinholes in the separator by light transmission. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-087385 A Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, the use of resin separators instead of conventional metal separators as separators for fuel cells has been considered. Resin separators may be thicker in order to ensure the same performance as metal separators. Therefore, when inspecting resin separators for pinholes by light transmission, the separators are so thick that even if pinholes exist in the separator, the light may not be able to transmit through the pinholes. As a result, the accuracy of pinhole detection may be reduced.

[0007] In view of the above circumstances, the present specification provides a technique for accurately detecting whether or not a pinhole is present in a separator. [Means for solving the problem]

[0008] The technology disclosed in this specification is embodied in a leak inspection device for a separator for a fuel cell. The separator includes a manifold hole for supplying or discharging gas, and a plurality of grooves extending radially from the manifold hole. The leak inspection device includes a pair of jigs for clamping the separator, a rubber seal member provided on one of the pair of jigs and abutting against the separator to form a sealed space between the one of the pair of jigs and the separator, a gas supplier for supplying gas to the sealed space, and a pressure gauge for monitoring the pressure of the sealed space. The seal member is disposed along the periphery of the manifold hole and includes a seal portion for the manifold hole abutting across the plurality of grooves. The seal portion for the manifold hole has a rectangular cross-sectional shape in an unloaded state, and its rubber hardness is 40 degrees to 80 degrees.

[0009] In the above leak inspection device, a seal member is provided on one of the pair of jigs. The seal member forms a sealed space between one of the pair of jigs and the separator by contacting the separator. In other words, the sealed space is defined by one of the pair of jigs, one surface of the separator, and the seal member. At this time, the seal portion for the manifold hole included in the seal member is arranged along the periphery of the manifold hole and needs to seal each of the multiple grooves extending radially from the manifold hole. In this regard, since the seal portion has a rectangular cross-sectional shape in an unloaded state, it can widely contact each of the multiple grooves and can reliably seal the multiple grooves. As a result, the leak inspection device can supply gas to the sealed space and monitor the pressure of the sealed space to determine whether or not gas leakage is occurring from the sealed space. That is, it can be determined that a defect such as the presence of a pinhole in the separator has occurred. Unlike an inspection by light transmission, such a leak inspection can accurately detect whether or not a pinhole exists regardless of the thickness of the separator. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a diagram for explaining a separator 100. [Diagram 2] 1 is a diagram showing a schematic configuration of a leak inspection device 10. Here, a separator 100 is placed on a stage of a lower jig 16. [Diagram 3] FIG. 3 is a diagram for explaining a seal member 20. [Figure 4] 4 is a cross-sectional view taken along line IV-IV in FIG. 3 . [Diagram 5] 1 is a diagram showing a schematic configuration of a leak inspection device 200 according to a second embodiment, in which a separator 100 is placed on a stage of a lower jig 16. [Figure 6] 1 is a diagram showing a schematic configuration of a leak inspection device 300 according to a third embodiment, in which a separator 100 is placed on a stage of a lower jig 16. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] In one embodiment of the present technology, the seal member may be made of ethylene propylene diene rubber. However, the seal member does not necessarily have to be made of ethylene propylene diene rubber. That is, any rubber material having a rubber hardness of 40 degrees to 80 degrees can be used as the seal member. EXAMPLES

[0012] (Example 1) A leak inspection device 10 of Example 1 will be described with reference to the drawings. The leak inspection device 10 of this example is a device for inspecting a separator 100 for a fuel cell. In particular, this leak inspection device 10 can detect the presence of defective parts such as pinholes in the separator 100. First, with reference to FIG. 1, the separator 100 to be inspected in this example will be described. Here, a case where the separator 100 is an anode side separator will be described. However, the separator 100 may also be a cathode side separator. As shown in FIG. 1, the separator 100 is a member having a plate shape. The separator 100 is made of a gas-impermeable conductive material, for example, a substrate containing titanium or a substrate containing carbon.

[0013] As shown in Fig. 1, the separator 100 has six manifold holes 102a-102f. The six manifold holes 102a-102f include three supply holes 102a-102c and three discharge holes 102d-102f. The three supply holes 102a-102c are holes for supplying fluid to the power generation region PG. The three discharge holes 102d-102f are holes for discharging the fluid that has passed through the power generation region PG. The three supply holes 102a-102c and the three discharge holes 102d-102f are each disposed at both ends of the separator 100 in the longitudinal direction. As one example, the first supply hole 102a is an anode gas supply hole, the first exhaust hole 102b is an anode gas exhaust hole, the second supply hole 102c is a cathode gas supply hole, the second exhaust hole 102d is a cathode gas exhaust hole, the third supply hole 102e is a cooling medium supply hole, and the third exhaust hole 102f is a cooling medium exhaust hole.

[0014] As shown in FIG. 1, the separator 100 further includes a flow path 104 and a plurality of grooves 106. The flow path 104 is provided in the center of the separator 100. In this embodiment, since the separator 100 is an anode-side separator, one surface of the separator 100 (hereinafter sometimes referred to as the "gas surface") is provided with a plurality of grooves 106 extending radially from the first supply hole 102a toward the flow path 104 through which the anode gas passes. In addition, the gas surface of the separator 100 is further provided with a plurality of grooves 106 extending radially from the first discharge hole 102b toward the flow path 104 through which the anode gas passes. As a result, the anode gas passes through the first supply hole 102a, the plurality of grooves 106, and the flow path 104 in this order, and is then supplied to the power generation region PG, and then passes through the flow path 104 and the plurality of grooves 106 in this order, and can be discharged to the first discharge hole 102b.

[0015] Although not particularly limited, the other surface (not shown) of separator 100 may be provided with a plurality of grooves 106 extending radially from third supply hole 102e toward flow path 104 through which the cooling medium passes, and a plurality of grooves 106 extending radially from third discharge hole 102f toward flow path 104 through which the cooling medium passes. This allows the cooling medium to pass through third supply hole 102e, the plurality of grooves 106, and flow path 104 in this order to cool the power generation region PG, and then pass through flow path 104 and the plurality of grooves 106 in this order to be discharged to third discharge hole 102f.

[0016] Next, the leak inspection device 10 will be described with reference to FIG. 2. As shown in FIG. 2, the leak inspection device 10 includes a main frame 12 and a pair of jigs 14, 16. The main frame 12 is a member for supporting components such as the pair of jigs 14, 16. The pair of jigs 14, 16 includes an upper jig 14 and a lower jig 16. The upper jig 14 and the lower jig 16 are arranged to face each other. A portion of the upper jig 14 facing the lower jig 16 and a portion of the lower jig 16 facing the upper jig 14 are both made of a metal plate having a predetermined thickness. As a result, the portion of the lower jig 16 facing the upper jig 14 can function as a stage for placing the separator 100 to be inspected.

[0017] As shown in FIG. 2, the leak inspection device 10 further includes a press mechanism 18. The press mechanism 18 is an actuator such as a hydraulic cylinder or an air cylinder. For example, the press mechanism 18 is provided on the upper jig 14 and can move the upper jig 14 in the up-down direction. With the separator 100 to be inspected placed on the stage of the lower jig 16, the upper jig 14 is moved downward using the press mechanism 18, whereby the separator 100 can be sandwiched between the upper jig 14 and the lower jig 16. At this time, the separator 100 is placed on the stage of the lower jig 16 so that the gas surface of the separator 100 faces downward.

[0018] As shown in FIG. 3, the leak inspection device 10 further includes a seal member 20. The seal member 20 is provided on the lower jig 16. The seal member 20 includes a plurality of seal portions 20a-20d for the manifold holes and a whole seal portion 20e. The plurality of seal portions 20a-20d for the manifold holes include a first seal portion 20a, a second seal portion 20b, a third seal portion 20c, and a fourth seal portion 20d. The first seal portion 20a is a seal portion corresponding to the first supply hole 102a, the second seal portion 20b is a seal portion corresponding to the first discharge hole 102b, the third seal portion 20c is a seal portion corresponding to the second supply hole 102c, and the fourth seal portion 20d is a seal portion corresponding to the second discharge hole 102d. When separator 100 is sandwiched between upper jig 14 and lower jig 16, each of the multiple seal portions 20a-20d for manifold holes is disposed along the periphery of the corresponding manifold hole 102a-102d. At this time, each of first seal portion 20a and second seal portion 20b can abut over multiple grooves 106 formed radially from the corresponding manifold hole (i.e., each of first supply hole 102a and first discharge hole 102b).

[0019] The full seal portion 20e is a seal portion that corresponds to the third supply hole 102e, the third discharge hole 102f, and the power generation region PG. When the separator 100 is sandwiched between the upper jig 14 and the lower jig 16, the full seal portion 20e can abut against the gas surface of the separator 100. As described above, the seal member 20 as a whole abuts against the separator 100, thereby forming an airtight space between the lower jig 16 and the separator 100.

[0020] As shown in FIG. 4, the seal member 20 has a rectangular cross-sectional shape in an unloaded state. As an example, a groove for arranging the seal member 20 is formed in the lower jig 16, and the seal member 20 is arranged so as to be accommodated in the groove. The thickness of the seal member 20 is, for example, 2 mm. The seal member 20 is made of a rubber material such as ethylene propylene diene rubber, and has a rubber hardness of 40 degrees to 80 degrees. Here, the rubber hardness means a hardness measured by a type A durometer conforming to JIS K 6253. The seal member 20 does not necessarily have to be made of ethylene propylene diene rubber. That is, any rubber material having a rubber hardness of 40 degrees to 80 degrees can be adopted as the seal member 20.

[0021] Although not particularly limited, the upper jig 14 may also be provided with a seal member 20, similar to the lower jig 16.

[0022] As shown in FIG. 2, the leak inspection device 10 further includes a gas supplier 22 and a pressure measuring device 24. The gas supplier 22 includes a gas supply source 22a and a valve 22b. The gas supply source 22a is connected to a gas supply path R provided in the lower jig 16 (and the main frame 12) and can supply gas to the sealed space described above. As an example, the gas supply source 22a includes a tank in which gas is stored and a compressor, and can supply gas pressurized to a predetermined pressure to the sealed space. The valve 22b is provided in the gas supply path R and can switch the supply state of gas from the gas supply source 22a to the sealed space. When the valve 22b is in an open state, gas is supplied from the gas supply source 22a to the sealed space, and when the valve 22b is in a closed state, the supply of gas from the gas supply source 22a to the sealed space is stopped. When the valve 22b is in a closed state, the sealing member 20 and the valve 22b seal the sealed space formed between the lower jig 16 and the separator 100. Although not particularly limited, the gas supplied from the gas supply source 22a is air, nitrogen, hydrogen, helium, or the like.

[0023] The pressure measuring instrument 24 is connected to the gas supply path R and is located between the sealed space and the gas supplier 22. Since the gas supply path R is in communication with the above-mentioned sealed space, the pressure measuring instrument 24 can monitor the pressure of the gas in the sealed space. For example, if the pressure difference between the pressure when the gas supply from the gas supplier 22 is stopped and the pressure after a predetermined time has elapsed thereafter is within an allowable range, it can be determined that no gas leak is occurring from the sealed space. As an example, the pressure measuring instrument 24 is a differential pressure leak tester.

[0024] As described above, the leak inspection device 10 supplies gas to the sealed space and monitors the pressure in the sealed space, thereby making it possible to determine whether or not gas is leaking from the sealed space. In other words, it is possible to determine whether or not a defect such as the presence of a pinhole has occurred in the separator 100. Unlike inspections using light transmission, this type of leak inspection can accurately detect whether or not a pinhole is present regardless of the thickness of the separator 100.

[0025] In the leak test device 10 of this embodiment, a sealed space is formed between the lower jig 16 and the separator 100 by the seal member 20. At this time, the first seal portion 20a arranged along the periphery of the first supply hole 102a needs to seal the multiple grooves 106 extending radially from the first supply hole 102a. Similarly, the second seal portion 20b arranged along the periphery of the first discharge hole 102b needs to seal the multiple grooves 106 extending radially from the first discharge hole 102b. In this regard, since the first seal portion 20a and the second seal portion 20b have a rectangular cross-sectional shape in the unloaded state, they can widely abut against each of the multiple grooves 106, and can reliably seal the multiple grooves 106.

[0026] (Example 2) Next, a leak inspection device 200 of Example 2 will be described. In this example, the arrangement of each component of Example 1 is changed, and the functions of each component are common. Therefore, the common components are given the same reference numerals, and the duplicated description will be omitted here. As shown in FIG. 5, in comparison with the leak inspection device 10 of Example 1, in the leak inspection device 200 of this example, a seal member 20 is provided on the upper jig 14, and the seal member 20 of the upper jig 14 abuts against the separator 100, so that a sealed space is formed between the upper jig 14 and the separator 100. In detail, in the leak inspection device 200, instead of the lower jig 16, the seal member 20, the gas supplier 22, and the pressure measuring device 24 are provided on the upper jig 14. In addition, in the leak inspection device 200, instead of the upper jig 14, a press mechanism 18 is provided on the lower jig 16. With this, in a state where the separator 100 to be inspected is placed on the stage of the lower jig 16, the lower jig 16 is moved upward using the press mechanism 18, whereby the separator 100 can be sandwiched between the upper jig 14 and the lower jig 16. In this manner, the seal member 20 as a whole comes into contact with the separator 100, thereby forming an airtight space between the upper jig 14 and the separator 100. Note that, in the leak inspection device 200 of the second embodiment, unlike the leak inspection device 10 of the first embodiment, the separator 100 is placed on the stage of the lower jig 16 so that the gas surface of the separator 100 is on the upper side.

[0027] Although not particularly limited, the leak test apparatus 10 may further include a tilt prevention guide (not shown). By providing the tilt prevention guide on the lower jig 16, it is possible to prevent the separator 100 arranged on the stage of the lower jig 16 from tilting when the lower jig 16 is moved up and down by the press mechanism 18. Also, as another embodiment, the leak test apparatus 200 of this embodiment may be provided with press mechanisms 18 on both the upper jig 14 and the lower jig 16.

[0028] With the above configuration, it is possible to determine whether or not gas is leaking from the sealed space by supplying gas to the sealed space and monitoring the pressure in the sealed space, i.e., whether or not a defect such as a pinhole exists in the separator 100.

[0029] (Example 3) Next, a leak inspection device 300 of Example 3 will be described. In this example, instead of the press mechanism 18 of Examples 1 and 2, an operator or the like clamps the separator 100 using the upper jig 14 and the lower jig 16. Therefore, in the leak inspection device 300, compared to Example 1, instead of the upper jig 14 being moved in the vertical direction by the press mechanism 18, the upper jig 14 is moved in the vertical direction by an operator or the like. In detail, the leak inspection device 300 further includes a handle 26, a guide pin 28, and a guide hole 30 instead of the press mechanism 18. Note that the other common components are given the same reference numerals, and the overlapping description will be omitted here. The handle 26 is provided on the upper jig 14. An operator or the like can easily move the upper jig 14 by holding the handle 26. As an example, the guide pin 28 is provided in the lower jig 16, and the guide hole 30 is provided in the upper jig 14. By inserting the guide pin 28 into the guide hole 30, an operator can move the upper jig 14 in the vertical direction without tilting the upper jig 14. Although not shown, the upper jig 14 can be fixed to the lower jig 16 using bolts, washers, nuts, etc., so that the separator 100 can be sandwiched between the upper jig 14 and the lower jig 16, as in the first and second embodiments.

[0030] With the above configuration, it is possible to determine whether or not gas is leaking from the sealed space by supplying gas to the sealed space and monitoring the pressure in the sealed space, i.e., whether or not a defect such as a pinhole exists in the separator 100.

[0031] Although several specific examples have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes to the specific examples exemplified above. The technical elements described in this specification or drawings exhibit technical usefulness alone or in combination. [Explanation of symbols]

[0032] 10, 200, 300: Leak inspection equipment 12: Mainframe 14: Upper jig 16: Lower jig 18: Press mechanism 20: Sealing material 20a-20d: Seal part 20e: Overall seal part 22: Gas supply 22a: Gas supply source 22b: Valve 24: Pressure measuring instrument 26: Handle 28: Guide pin 30: Guide hole 100: Separator 102a-102f: Manifold holes 104: Flow path 106: Groove PG: Power generation area R: Gas supply route

Claims

1. A leak inspection device for a separator for a fuel cell, the device comprising: a manifold hole for supplying or discharging a gas; and a plurality of grooves extending radially from the manifold hole, A pair of jigs that sandwich the separator; a rubber seal member provided on one of the pair of jigs and abutting against one surface of the separator in a thickness direction of the separator to form an enclosed space between the one of the pair of jigs and the one surface of the separator; A gas supplier for supplying gas to the sealed space; a pressure measuring device for monitoring the pressure in the sealed space; Equipped with the seal member is disposed on the one surface of the separator so as to surround a periphery of the manifold hole and includes a seal portion for the manifold hole that abuts across the plurality of grooves, The manifold hole seal portion has a rectangular cross-sectional shape in an unloaded state, and its rubber hardness is 40 degrees to 80 degrees. Leak testing equipment.

2. 2. The leak test device according to claim 1, wherein the seal member is made of ethylene propylene diene rubber.

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