JP2023097975A - Leak inspection device of separator - Google Patents

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 The technology disclosed in the present specification relates to a separator leak inspection device for a fuel cell.

A fuel cell is configured by stacking a plurality of fuel cells. Each fuel cell includes a pair of separators (that is, an anode-side separator and a cathode-side separator), a membrane electrode assembly (MEA: Membrane Electrode Assembly), an anode-side gas diffusion layer, and a cathode-side gas diffusion layer. Prepare.

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

Separators of fuel cells are required to be free of pinholes. In relation to this, Patent Literature 1 describes an inspection device for separators for fuel cells. This inspection device includes a light projecting section that emits light toward one surface of the separator, and a light receiving section that detects the light transmitted through the pinholes of the separator on the other surface side of the separator. According to such a configuration, it is possible to inspect whether or not there is a pinhole in the separator by light transmission.

JP 2019-087385 A

In recent years, as a separator for fuel cells, adoption of a resin separator instead of a conventional metal separator has been studied. A separator made of resin may have a larger thickness in order to ensure performance equivalent to that of a separator made of metal. Therefore, when inspecting the presence or absence of pinholes in a resin separator by light transmission, even if there are pinholes in the separator due to the thickness of the separator, light may not be able to pass through the pinholes. There is As a result, the pinhole detection accuracy may be degraded.

In view of the above circumstances, the present specification provides a technique for accurately detecting whether pinholes are present in the separator.

The technology disclosed in this specification is embodied in a fuel cell separator leak inspection device. The separator has a manifold hole for supplying or discharging gas, and a plurality of grooves radially extending from the manifold hole. The leak inspection device includes a pair of jigs that sandwich the separator, and one of the jigs that is provided in the pair of jigs. It comprises a rubber seal member forming a closed space, a gas supply device for supplying gas to the closed space, and a pressure measuring device for monitoring the pressure in the closed space. The sealing member includes a sealing portion for the manifold hole that is arranged along the periphery of the manifold hole and abuts across the plurality of grooves. The manifold hole sealing portion has a rectangular cross-sectional shape in an unloaded state and has a rubber hardness of 40 to 80 degrees.

In the leak inspection device described above, one of the pair of jigs is provided with a sealing member. The sealing member forms a closed space between one of the pair of jigs and the separator by contacting the separator. In other words, the closed space is defined by one of the pair of jigs, one surface of the separator, and the sealing member. At this time, the manifold hole sealing portion included in the sealing member is arranged along the periphery of the manifold hole, and needs to seal each of the plurality of grooves radially extending 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 plurality of grooves, and can reliably seal the plurality of grooves. Accordingly, the leak inspection device supplies gas to the sealed space and monitors the pressure in the sealed space, thereby determining whether or not gas is leaking from the sealed space. That is, it can be determined that there is a problem such as the presence of pinholes in the separator. Such a leak inspection can accurately detect the presence or absence of pinholes regardless of the thickness of the separator, unlike inspection using light transmission.

FIG. 4 is a diagram for explaining the separator 100; 1 is a diagram showing a schematic configuration of a leak inspection device 10; FIG. Here, the separator 100 is arranged on the stage of the lower jig 16 . FIG. 4 is a diagram for explaining a sealing member 20; Sectional drawing in the IV-IV line of FIG. FIG. 10 is a diagram showing a schematic configuration of a leak inspection device 200 according to a second embodiment; FIG. Here, the separator 100 is arranged on the stage of the lower jig 16 . The figure which shows the schematic structure of the leak test apparatus 300 of Example 3. FIG. Here, the separator 100 is arranged on the stage of the lower jig 16 .

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

(Embodiment 1) A leak inspection apparatus 10 of Embodiment 1 will be described with reference to the drawings. A leak inspection apparatus 10 of this embodiment is an apparatus for inspecting a separator 100 for a fuel cell. In particular, the leak inspection device 10 can detect the presence of a defective portion such as a pinhole in the separator 100 . First, with reference to FIG. 1, a separator 100 to be inspected in this embodiment will be described. Here, the case where the separator 100 is the anode-side separator will be described. However, the separator 100 may be a cathode-side separator. As shown in FIG. 1, the separator 100 is a plate-shaped member. The separator 100 is made of a gas-impermeable conductive material such as a titanium-containing base material or a carbon-containing base material.

As shown in FIG. 1, separator 100 includes six manifold holes 102a-102f. The six manifold holes 102a-102f include three supply holes 102a-102c and three exhaust 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 fluid that has passed through the power generation region PG. Each of the three supply holes 102a-102c and the three discharge holes 102d-102f are arranged at both ends of the separator 100 in the longitudinal direction. As an example, the first supply hole 102a is an anode gas supply hole, the first discharge hole 102b is an anode gas discharge hole, the second supply hole 102c is a cathode gas supply hole, and the second discharge hole 102d is These are cathode gas discharge holes, the third supply holes 102e are cooling medium supply holes, and the third discharge holes 102f are cooling medium discharge holes.

As shown in FIG. 1, separator 100 further comprises channel 104 and a plurality of grooves 106 . Channel 104 is provided in the central portion of 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 a "gas surface") has a channel through which the anode gas passes from the first supply holes 102a. A plurality of radially extending grooves 106 are provided toward 104 . In addition, the gas side of the separator 100 is further provided with a plurality of grooves 106 radially extending from the first discharge holes 102b toward the flow path 104 through which the anode gas passes. As a result, the anode gas sequentially passes through the first supply hole 102a, the plurality of grooves 106, and the flow path 104, is supplied to the power generation region PG, and then passes through the flow path 104 and the plurality of grooves 106 in this order. It can be discharged to the first discharge hole 102b.

Although not particularly limited, the other surface (not shown) of the separator 100 has a plurality of grooves 106 radially extending from the third supply holes 102e toward the flow path 104 through which the cooling medium passes, A plurality of grooves 106 extending radially toward a flow path 104 through which the cooling medium passes may be provided. As a result, the cooling medium sequentially passes through the third supply hole 102e, the plurality of grooves 106, and the flow path 104, cools the power generation region PG, and then passes through the flow path 104 and the plurality of grooves 106 in this order. 3 can be discharged to the discharge hole 102f.

Next, the leak inspection device 10 will be described with reference to FIG. As shown in FIG. 2, the leak test apparatus 10 includes a main frame 12 and a pair of jigs 14 and 16. As shown in FIG. The main frame 12 is a member for supporting components such as a pair of jigs 14 and 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 so as 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. Thereby, the portion of the lower jig 16 facing the upper jig 14 can function as a stage for arranging the separator 100 to be inspected.

As shown in FIG. 2 , the leak test 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 vertical direction. With the separator 100 to be inspected placed on the stage of the lower jig 16, the press mechanism 18 is used to move the upper jig 14 downward. The separator 100 can be sandwiched by the tool 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.

As shown in FIG. 3 , the leak test device 10 further includes a seal member 20 . The sealing member 20 is provided on the lower jig 16 . Seal member 20 includes a plurality of manifold hole seal portions 20a-20d and an overall seal portion 20e. The plurality of manifold hole seals 20a-20d includes a first seal 20a, a second seal 20b, a third seal 20c and a fourth seal 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, and the third seal portion 20c is a seal portion corresponding to the second supply hole 102c. They are corresponding seal portions, and the fourth seal portion 20d is a seal portion corresponding to the second discharge hole 102d. When the separator 100 is sandwiched between the upper jig 14 and the lower jig 16, each of the plurality of manifold hole seal portions 20a-20d is arranged along the periphery of the corresponding manifold hole 102a-102d. . At this time, each of the first seal portion 20a and the second seal portion 20b has a plurality of grooves radially formed from the corresponding manifold hole (that is, each of the first supply hole 102a and the first discharge hole 102b). 106 can be abutted.

The overall seal portion 20e is a seal portion corresponding 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 entire seal portion 20e can come into contact with the gas surface of the separator 100. As shown in FIG. As described above, the sealing member 20 as a whole contacts the separator 100 , thereby forming a sealed space between the lower jig 16 and the separator 100 .

As shown in FIG. 4, the seal member 20 has a rectangular cross-sectional shape in the unloaded state. As an example, the lower jig 16 is formed with a groove for arranging the seal member 20, and the seal member 20 is arranged so as to be accommodated in the groove. The thickness of the sealing member 20 is, for example, 2 mm. The sealing 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 hardness measured by a type A durometer altimeter conforming to JIS K 6253. Note that 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 used as the sealing member 20 .

Although not particularly limited, the upper jig 14 may also be provided with the sealing member 20 in the same manner as the lower jig 16 .

As shown in FIG. 2 , the leak test 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 gas supply state from the gas supply source 22a to the closed space. When the valve 22b is open, gas is supplied from the gas supply source 22a to the closed space, and when the valve 22b is closed, the supply of gas from the gas supply source 22a to the closed space is stopped. Further, when the valve 22b is closed, the sealed space formed between the lower jig 16 and the separator 100 is sealed by the sealing member 20 and the valve 22b. Although not particularly limited, the gas supplied from the gas supply source 22a is air, nitrogen, hydrogen, helium, or the like.

A pressure measuring device 24 is connected to the gas supply path R and positioned between the closed space and the gas supplier 22 . Since the gas supply path R communicates with the sealed space described above, the pressure measuring device 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 supply device 22 is stopped and the pressure after a predetermined time has passed is within an allowable range, gas leakage from the sealed space has occurred. It can be determined that no As an example, the pressure measuring device 24 is a differential pressure leak tester.

As described above, the leak test apparatus 10 can 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. In other words, it can be determined that there is a problem such as the presence of pinholes in the separator 100 . Unlike an inspection using light transmission, such a leak inspection can accurately detect whether or not a pinhole exists regardless of the thickness of the separator 100 .

In the leak test apparatus 10 of this embodiment, the seal member 20 forms a closed space between the lower jig 16 and the separator 100 . At this time, the first seal portion 20a arranged along the periphery of the first supply hole 102a needs to seal the plurality of grooves 106 radially extending from the first supply hole 102a. Similarly, the second sealing portion 20b arranged along the periphery of the first discharge hole 102b must seal the plurality of grooves 106 radially extending 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 an unloaded state, they can widely contact each of the plurality of grooves 106, and the plurality of grooves 106 can be reliably sealed.

(Embodiment 2) Next, a leak inspection apparatus 200 of Embodiment 2 will be described. The present embodiment is obtained by changing the arrangement of each component of the first embodiment, and the function of each component is common. Therefore, overlapping description is omitted here by attaching the same reference numerals to the common components. As shown in FIG. 5, in the leak test apparatus 200 of the present embodiment, the sealing member 20 is provided on the upper jig 14, and the sealing of the upper jig 14 is performed as compared with the leak test apparatus 10 of the first embodiment. A closed space is formed between the upper jig 14 and the separator 100 by the contact of the member 20 with the separator 100 . Specifically, in the leak test apparatus 200 , instead of the lower jig 16 , the upper jig 14 is provided with a sealing member 20 , a gas supplier 22 , and a pressure measuring device 24 . In addition, in leak test apparatus 200 , press mechanism 18 is provided in lower jig 16 instead of upper jig 14 . With the separator 100 to be inspected placed on the stage of the lower jig 16, the press mechanism 18 is used to move the lower jig 16 upward. The separator 100 can be sandwiched by the jig 16 . Thus, the sealing member 20 as a whole can form a closed space between the upper jig 14 and the separator 100 by contacting the separator 100 . In addition, in the leak test apparatus 200 of the second embodiment, unlike the leak test apparatus 10 of the first embodiment, the separator 100 is arranged on the stage of the lower jig 16 so that the gas surface of the separator 100 faces upward.

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, the separator 100 placed on the stage of the lower jig 16 is prevented from tilting when the lower jig 16 is moved vertically by the press mechanism 18. can do. Moreover, as another embodiment, the leak test apparatus 200 of this embodiment may be provided with the press mechanism 18 on both the upper jig 14 and the lower jig 16 .

With the above configuration as well, it is possible to determine whether gas is leaking from the sealed space by supplying gas to the sealed space and monitoring the pressure in the sealed space. In other words, it can be determined that there is a problem such as the presence of pinholes in the separator 100 .

(Embodiment 3) Next, a leak inspection apparatus 300 of Embodiment 3 will be described. In this embodiment, instead of the press mechanism 18 of the first and second embodiments, an operator or the like uses an upper jig 14 and a lower jig 16 to clamp the separator 100 . Therefore, in the leak test apparatus 300, unlike the first embodiment, the upper jig 14 is moved vertically by the operator or the like instead of being vertically moved by the press mechanism 18. is configured to Specifically, the leak test apparatus 300 further includes a handle 26 , a guide pin 28 and a guide hole 30 instead of the press mechanism 18 . By attaching the same reference numerals to other common constituent elements, overlapping descriptions will be omitted here. A handle 26 is provided on the upper jig 14 . A worker or the like can easily move the upper jig 14 by grasping the handle 26 . As an example, the guide pins 28 are provided in the lower jig 16 and the guide holes 30 are provided in the upper jig 14 . By inserting the guide pin 28 into the guide hole 30, the operator or the like can move the upper jig 14 vertically without tilting it. Although not shown, by fixing the upper jig 14 to the lower jig 16 using bolts, washers, nuts, etc., the upper jig 14 and the lower jig can be connected in the same manner as in the first and second embodiments. The separator 100 can be sandwiched between the members 16 .

With the above configuration as well, it is possible to determine whether gas is leaking from the sealed space by supplying gas to the sealed space and monitoring the pressure in the sealed space. In other words, it can be determined that there is a problem such as the presence of pinholes in the separator 100 .

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 of the specific examples illustrated above. The technical elements described in this specification or drawings exhibit technical usefulness either singly or in combination.

10, 200, 300: Leak inspection device 12: Main frame 14: Upper jig 16: Lower jig 18: Press mechanism 20: Seal members 20a to 20d: Seal portion 20e: Overall seal portion 22: Gas supplier 22a: Gas supply source 22b : Valve 24 : Pressure measuring device 26 : Handle 28 : Guide pin 30 : Guide hole 100 : Separator 102a-102f : Manifold hole 104 : Channel 106 : Groove PG : Power generation region R : Gas supply route

Claims (2)

A fuel cell separator leak inspection device comprising a manifold hole for supplying or discharging gas and a plurality of grooves radially extending from the manifold hole,
a pair of jigs that sandwich the separator;
a rubber sealing member that is provided on one of the pair of jigs and forms a sealed space between the one of the pair of jigs and the separator by coming into contact with the separator;
a gas supplier that supplies gas to the closed space;
a pressure measuring device for monitoring the pressure in the closed space;
with
The sealing member includes a sealing portion for the manifold hole disposed along the periphery of the manifold hole and abutting across the plurality of grooves,
The sealing portion for the manifold hole has a rectangular cross-sectional shape in an unloaded state and has a rubber hardness of 40 degrees to 80 degrees.
Leak inspection device. 2. The leak inspection device according to claim 1, wherein said seal member is made of ethylene propylene diene rubber.

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