Manufacturing method of sealing member for fuel cell and manufacturing device of sealing member for fuel cell

Abstract

To provide a method of manufacturing a seal member for a fuel cell and an apparatus of manufacturing the seal member for the fuel cell capable of improving releasability of the seal member.SOLUTION: A method of manufacturing a seal member comprises a molding step and a releasing step. In the molding step, the seal member is molded by injecting resin between a stationary mold 50 provided with a first ridge 56 and a first groove 57 and a movable mold 60 provided with a second ridge 66 and a second groove 67. In the molding step, a comb-like portion is molded by injecting the resin into a cavity C formed by the first ridge 56, the first groove 57, the second ridge 66, and the second groove 67. In the releasing step, the seal member is released from the movable mold 60 by pushing out the seal member with an ejector pin provided to be retractable from the movable mold 60 while the stationary mold 50 and the movable mold 60 are mold opened.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a method and an apparatus for manufacturing a seal member for a fuel cell. [Background technology]

[0002] Conventionally, a separator for a fuel cell has a supply manifold to which a reactant gas is supplied, a discharge manifold from which the reactant gas is discharged, and a gas flow path that faces the membrane electrode assembly and through which the reactant gas flows.

[0003] Patent Document 1 discloses a separator provided with a communication passage that connects a manifold and a gas flow passage. The communication passage is formed by a plurality of recesses arranged in parallel with each other. A resin sealing plate that covers the recesses is attached to the communication passage. This allows the reactant gas to flow between the manifold and the gas flow passage through the communication passage. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-26633 Summary of the Invention [Problem to be solved by the invention]

[0005] In the communicating passages described in Patent Document 1, it is conceivable to increase the cross-sectional area of ​​the recesses, i.e., to increase the depth of the recesses, in order to ensure the flow rate of the reactant gas. However, if the depth of the recesses is increased, there is a risk that the thickness of the separator will increase.

[0006] Therefore, in order to prevent an increase in separator thickness, the present inventors studied the structure of a resin seal member that is attached to the separator to form a communication passage together with the separator. This seal member has an annular frame that is attached to the manifold and a comb-tooth portion that cantilever-extends from the frame toward the gas flow passage and forms a communication passage together with the separator. However, when molding such a seal member by injection molding, the following problem may occur. Specifically, when the injection molding mold used for molding the seal member is opened after molding, the comb-tooth portion may get stuck in the mold, making it difficult to release the seal member. This problem becomes more pronounced as the width and thickness of the comb-tooth portion become smaller. Therefore, it is desirable to improve the mold releasability of seal members having comb-tooth portions. [Means for solving the problem]

[0007] A method for manufacturing a sealing member for a fuel cell that solves the above problems is a method for manufacturing a sealing member for a fuel cell that is attached to a separator for the fuel cell having a plurality of manifolds that supply or discharge fluids and a flow path through which the fluids flow, the sealing member having an annular frame portion attached to the manifolds and a comb-tooth portion extending cantilevered from the frame portion toward the flow path, the comb-tooth portion forming a communication path that communicates the manifolds with the flow path together with the separator, and a sealing member that contacts the bottom surface of the first grooves and has a fixed mold on which first ridges and first grooves are provided alternately. and a demolding step, which, after the molding step, releases the sealing member from the movable mold by pushing out the sealing member with an ejector pin that is provided so as to be retractable into the movable mold while the fixed mold and the movable mold are open, wherein the molding step molds the comb-tooth portion by injecting the resin into a cavity formed by the first protrusions, the first grooves, the second protrusions, and the second grooves.

[0008] According to this method, in the molding process, the comb-tooth portion is molded by injecting resin into a cavity formed by the first ridges, the first grooves, the second ridges, and the second grooves. Here, the cavity is formed by the tip surfaces of the first ridges contacting the second grooves and the second ridges contacting the bottom surfaces of the first grooves. This reduces the difference between the proportion of the cavity occupied by the fixed mold and the proportion of the cavity occupied by the movable mold. In other words, this reduces the difference between the contact area of ​​the comb-tooth portion with the fixed mold and the contact area of ​​the movable mold. This prevents the comb-tooth portion from getting stuck in the movable mold. Therefore, in the demolding process, the seal member is pushed out by an ejector pin, allowing for smooth demolding of the seal member. This improves the releasability of the seal member.

[0009] A manufacturing apparatus for a sealing member for a fuel cell that solves the above problem is a manufacturing apparatus for a sealing member for a fuel cell that is attached to a separator for the fuel cell having a plurality of manifolds that supply or discharge fluid and a flow path through which the fluid flows, the sealing member has an annular frame portion that is attached to the manifold and a comb-tooth portion that extends cantilevered from the frame portion toward the flow path, and the comb-tooth portion, together with the separator, forms a communication passage that connects the manifold and the flow path, and the manufacturing apparatus is equipped with a fixed mold in which first protrusions and first grooves are arranged alternately, and a movable mold in which second protrusions that contact the bottom surfaces of the first grooves and second grooves that contact the tip surfaces of the first protrusions are arranged alternately, and the movable mold is provided with an ejector pin that can be projected and retracted to push out the sealing member, and when the fixed mold and the movable mold are clamped together, a cavity that molds the comb-tooth portion is formed by the first protrusions, the first grooves, the second protrusions, and the second grooves.

[0010] According to this configuration, the comb-tooth portion is molded by injecting resin into a cavity formed by the first ridges, the first grooves, the second ridges, and the second grooves. Here, the cavity is formed by the tip surfaces of the first ridges contacting the second grooves and the second ridges contacting the bottom surfaces of the first grooves. This reduces the difference between the proportion of the cavity occupied by the fixed mold and the proportion of the cavity occupied by the movable mold. In other words, this reduces the difference between the contact area of ​​the comb-tooth portion with the fixed mold and the contact area of ​​the movable mold. This prevents the comb-tooth portion from getting stuck in the movable mold. Therefore, the seal member can be smoothly released from the mold by pushing it out with the ejector pin. This improves the releasability of the seal member.

[0011] A method for manufacturing a sealing member for a fuel cell that solves the above problems is a method for manufacturing a sealing member for a fuel cell that is attached to a separator for the fuel cell having a plurality of manifolds that supply or discharge fluids and a flow path through which the fluids flow, the sealing member having an annular frame portion that is attached to the manifolds and a comb-tooth portion that extends cantilevered from the frame portion toward the flow path, the comb-tooth portion forming a communication path that communicates the manifolds with the flow path together with the separator, the method comprising: a fixed mold; an outer molding portion that molds an outer periphery of the sealing member; a molding process in which the sealing member is molded by injecting the resin between a movable mold and a fixed mold that is configured separately from the fixed mold and has an inner molding portion that molds the portion of the sealing member that is more inward than the outer periphery; a pressing process in which, after the molding process, the fixed mold and the movable mold are opened, the outer molding portion is protruded toward the fixed mold to press the outer periphery toward the fixed mold; and a demolding process in which, after the pressing process, the sealing member is pushed out by an ejector pin that is provided so as to be able to appear and disappear from the inner molding portion, thereby releasing the sealing member from the movable mold.

[0012] According to this method, the outer peripheral portion of the seal member molded in the molding step is pressed toward the fixed mold by the outer molding part in the pressing step. As a result, a portion of the seal member, including the comb-tooth portion, is released from the inner molding part. Then, in the demolding step, the seal member is pushed out by an ejector pin, and the entire seal member is released from the movable mold. In this way, the comb-tooth portion is gradually released from the movable mold, allowing the seal member to be released smoothly. Therefore, the releasability of the seal member can be improved.

[0013] To solve the above problem, a manufacturing device for a sealing member for a fuel cell is provided which is attached to a separator for the fuel cell having a plurality of manifolds for supplying or discharging a fluid and a flow path through which the fluid flows, wherein the sealing member has an annular frame portion attached to the manifold and a comb-tooth portion extending cantilevered from the frame portion toward the flow path, and the comb-tooth portion forms a communication passage connecting the manifold and the flow path together with the separator, and the device is provided with a fixed mold, an outer molding portion which molds the outer periphery of the sealing member, and a movable mold which is configured separately from the outer molding portion and has an inner molding portion which molds the portion of the sealing member that is more inward than the outer periphery, and the outer molding portion is configured to be able to advance and retreat relative to the inner molding portion in the direction in which the movable mold advances and retreats relative to the fixed mold, and the inner molding portion is provided with an ejector pin which can be projected and retracted to push out the sealing member.

[0014] According to this configuration, after the fixed and movable molds are opened, the outer mold portion is moved toward the fixed mold relative to the inner mold portion, causing the outer mold portion to press the outer periphery of the seal member toward the fixed mold. This causes a portion of the seal member, including the comb-tooth portion, to be released from the inner mold portion. Then, the ejector pin presses the seal member toward the fixed mold, causing the entire seal member to be released from the movable mold. In this way, the comb-tooth portion can be released from the movable mold in stages. This improves the releasability of the seal member. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is an exploded perspective view showing a power generating cell in the first embodiment. [Figure 2] FIG. 2 is a plan view showing the sealing member in the first embodiment. [Figure 3] FIG. 3 is an exploded perspective view showing the manufacturing apparatus for the seal member according to the first embodiment. [Figure 4] FIG. 4 is a perspective view showing the fixed mold in the first embodiment. [Figure 5] FIG. 5 is a perspective view showing a movable mold in the first embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing a cavity for molding the comb-tooth portion in the first embodiment. [Figure 7] FIG. 7 is a cross-sectional view showing a molding step in the method for manufacturing the seal member according to the first embodiment. [Figure 8] FIG. 8 is a perspective view showing a demolding step in the method for manufacturing the seal member according to the first embodiment. [Figure 9] FIG. 9 is an exploded perspective view showing a manufacturing apparatus for a seal member according to the second embodiment. [Figure 10] FIG. 10 is a perspective view showing a fixed mold in the second embodiment. [Figure 11] FIG. 11 is a perspective view showing a movable mold in the second embodiment. [Figure 12] FIG. 12 is a perspective view showing a state in which the outer molding part of the movable mold in the second embodiment is protruding. [Figure 13] FIG. 13 is a cross-sectional view showing a cavity for molding comb-tooth portions in the second embodiment. [Figure 14] FIG. 14 is a cross-sectional view showing a pressing step in the method for manufacturing the seal member according to the second embodiment. [Figure 15] FIG. 15 is a perspective view showing a demolding step in the method for manufacturing the seal member according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] First Embodiment A first embodiment of a method and an apparatus for manufacturing a sealing member for a fuel cell will be described below with reference to FIGS.

[0017] First, the power generating cell 10 to which the sealing member 30 is applied will be described. (Power generating cell 10) 1 and 2, a polymer electrolyte fuel cell is configured by stacking a plurality of power generating cells 10. In a plan view, the power generating cells 10 have, for example, a rectangular shape having long and short sides.

[0018] Hereinafter, the long side direction and the short side direction of the power generating cell 10 will be simply referred to as the long side direction and the short side direction, respectively. The power generation cell 10 includes a sheet-shaped membrane electrode gas diffusion layer assembly 11, a frame-shaped frame 12 that holds the outer periphery of the membrane electrode gas diffusion layer assembly 11, and two separators 20 that sandwich the membrane electrode gas diffusion layer assembly 11 and the frame 12.

[0019] At both ends of the power generation cell 10 in the long side direction, multiple manifolds 21 are provided to supply or discharge fluid. Three manifolds 21 are provided at each end of the power generation cell 10. The three manifolds 21 are provided at intervals from each other in the short side direction. The manifolds 21 penetrate the frame 12 and the two separators 20. Examples of fluids include reactive gases such as air and hydrogen, and cooling water.

[0020] For example, air is supplied from manifold 21A and discharged from manifold 21B. Hydrogen is supplied from manifold 21C and discharged from manifold 21D. Cooling water is supplied from manifold 21E and discharged from manifold 21F.

[0021] The separator 20 has, for example, a rectangular plate shape. The separator 20 can be made of, for example, a metal material such as stainless steel, or a composite material containing conductive particles and a resin material.

[0022] The separator 20 is positioned between the three manifolds 21A, 21F, and 21D and the three manifolds 21C, 21E, and 21B, and has flow paths 22 through which a fluid flows. The flow path 22 has a main flow path 23 located in the center of the separator 20 and two connection flow paths 24 extending from both ends of the main flow path 23 toward the manifold 21 .

[0023] The main flow channel 23 is composed of a plurality of grooves extending in the long side direction of the separator 20 in the center of the separator 20. The main flow channel 23 faces the membrane electrode-gas diffusion layer assembly 11. The connection flow channel 24 extends from the main flow channel 23 toward the manifold 21 located on one side or the other of the short side direction.

[0024] A seal member 30 is attached to the manifold 21. The seal member 30 is sandwiched between the separator 20 and the frame 12, or between the separator 20 and the separator 20 of another power-generating cell 10, thereby preventing fluid from leaking out from between them.

[0025] The seal members 30 are attached to, for example, each of the manifolds 21A, 21B, 21C, and 21D through which the reaction gas flows. The seal members 30 may also be attached to each of the manifolds 21E and 21F through which the cooling water flows.

[0026] (Sealing member 30) The seal member 30 has a frame portion 31 attached to the manifold 21, and a comb-tooth portion 32 extending in a cantilevered manner from the frame portion 31 toward the flow path 22. The seal member 30 has a thin plate shape.

[0027] 2, the frame portion 31 has a through hole 31a that communicates with the manifold 21. The frame portion 31 has a connection portion 31b that constitutes a part of the through hole 31a and to which the base end of the comb-tooth portion 32 is connected.

[0028] The frame 31 is provided with protrusions 36 that protrude from both sides in the thickness direction. The protrusions 36, for example, surround the periphery of the through-hole 31a excluding the connection portions 31b. Note that a plurality of protrusions 36 may be provided at intervals in the circumferential direction of the through-hole 31a. The protrusions 36 have the function of preventing fluid from leaking out of the power generation cell 10 by coming into contact with the frame 12 or other separators 20.

[0029] As shown by the dashed lines in FIG. 2, a portion of the connecting portion 31b facing the separator 20 is provided with a plurality of communication grooves 33 extending from the through-hole 31a toward the comb-tooth portion 32 at intervals.

[0030] The comb-tooth portion 32 has a plurality of extending portions 34 extending in a cantilevered manner from the connecting portion 31b. The extending portions 34 are spaced apart from one another in the circumferential direction of the through-hole 31a. Slits 35 are formed between the extending portions 34. Each slit 35 is connected to a communicating groove 33.

[0031] When the seal member 30 is attached to the manifold 21, the space partitioned by the communicating groove 33, the slit 35, and the separator 20 functions as a space through which the fluid flows. That is, the communicating groove 33 and the slit 35, together with the separator 20, form a communicating passage 37 that communicates with the connecting passage 24. The communicating passage 37 distributes the fluid flowing from the manifold 21 toward the passage 22.

[0032] Although not shown in the drawings, the sealing member 30 has, for example, a plurality of protruding pieces that protrude from the frame portion 31 in one direction in the thickness direction and are inserted into the manifold 21. The protruding pieces are thermally caulked to the separator 20, thereby fixing the sealing member 30 to the separator 20.

[0033] (Manufacturing apparatus 40 for sealing member 30) As shown in FIG. 3, the manufacturing device for the seal member 30 (hereinafter referred to as manufacturing device 40) includes a fixed mold 50 and a movable mold 60 that is configured to be able to advance and retreat relative to the fixed mold 50.

[0034] As shown in FIG. 4, the fixed mold 50 has a fixed-side plate 51 and a cavity block 52 housed in the fixed-side plate 51. The fixed plate 51 has a sprue 51a into which the thermoplastic resin that is the material of the seal member 30 is injected (see FIG. 3).

[0035] The cavity block 52 has a first molding surface 53 that molds one surface in the thickness direction of the seal member 30. The first molding surface 53 has a first frame molding portion 54 that molds the connecting portion 38 and frame portion 31 of the seal member 30, which will be described later, and a first comb-tooth molding portion 55 that molds the comb-tooth portion 32.

[0036] The first frame molding portion 54 has a molding recess 54a for molding the protrusion 36, and a communication hole 54b that passes through the cavity block 52 and communicates with the sprue 51a. The first comb-tooth forming portion 55 has first ridges 56 and first grooves 57 arranged alternately in the circumferential direction of the first frame forming portion 54.

[0037] 6, the width of the first ridges 56 is smaller than the width of the first grooves 57. The first ridges 56 have first end faces 56a that contact second bottom faces 67a of second grooves 67, which will be described later. The first grooves 57 have first bottom faces 57a that contact second end faces 66a of second ridges 66, which will be described later. The first end faces 56a and the first bottom faces 57a are flat.

[0038] 4, the first comb-tooth-forming portion 55 has a first flat portion 55a having a flat shape. The first ridges 56 protrude from the first flat portion 55a. The first grooves 57 are formed between two adjacent first ridges 56 on the first flat portion 55a. In other words, a first bottom surface 57a of the first grooves 57 is part of the first flat portion 55a.

[0039] As shown in FIG. 5, the movable die 60 has a movable plate 61 and a core block 62 housed in the movable plate 61 . The core block 62 has a second molding surface 63 that molds the other surface in the thickness direction of the seal member 30. The second molding surface 63 has a second frame molding portion 64 that molds the frame portion 31, a second comb-tooth molding portion 65 that molds the comb-tooth portion 32, and a runner portion 70 that is continuous with the second frame molding portion 64 and molds the connecting portion 38.

[0040] The second frame molding portion 64 forms a cavity (not shown) for molding the frame portion 31 together with the first frame molding portion 54 . The second comb-tooth forming portion 65 has second ridges 66 and second grooves 67 arranged alternately in the circumferential direction of the second frame forming portion 64 .

[0041] 6, the width of the second ridges 66 is smaller than the width of the second grooves 67. The second ridges 66 have second end faces 66a that contact the first bottom faces 57a of the first grooves 57. The second grooves 67 have second bottom faces 67a that contact the first end faces 56a of the first ridges 56. The second end faces 66a and the second bottom faces 67a are flat.

[0042] 5, the second comb-tooth-forming portion 65 has a planar second flat portion 65a. The second grooves 67 are formed in the second flat portion 65a. The second ridges 66 are formed between two adjacent second grooves 67 in the second flat portion 65a. In other words, the second protrusions 66 have second end faces 66a that are part of the second flat portion 65a.

[0043] 6, when the fixed mold 50 and the movable mold 60 are clamped together, the first protruding end faces 56a of the first ridges 56 contact the second bottom faces 67a of the second grooves 67, and the second protruding end faces 66a of the second ridges 66 contact the first bottom faces 57a of the first grooves 57. This forms cavities C in which the comb teeth 32 are formed between the first comb teeth-forming portions 55 and the second comb teeth-forming portions 65. When the cavities C are formed, the first ridges 56 and the second ridges 66 are arranged alternately.

[0044] The pitch of the first ridges 56 is the same as the pitch of the second ridges 66. The cross-sectional shape of the first ridges 56 perpendicular to the length direction is substantially the same as the cross-sectional shape of the second ridges 66 perpendicular to the length direction.

[0045] As a result of the above, the proportion of the cavity C occupied by the first comb teeth molding portion 55 and the proportion of the second comb teeth molding portion 65 are approximately the same. In other words, the contact area of ​​the first comb teeth molding portion 55 with the comb teeth portion 32 is approximately the same as the contact area of ​​the second comb teeth molding portion 65 with the comb teeth portion 32.

[0046] 5, the runner portion 70 has a recess 71 that communicates with the communication hole 54b of the cavity block 52, and three runners 73 that branch off and extend from the recess 71. Resin for molding the seal member 30 flows through the runner portion 70.

[0047] The recess 71 is provided with a cold slug well 72 for storing cold slug, which is a part of the resin that has solidified. One of the three runners 73 is connected to a portion of the second comb tooth molding portion 65 that molds the connecting portion 31b. Two of the three runners 73 are connected to a portion of the second frame molding portion 64 excluding the portion that molds the connecting portion 31b.

[0048] The movable die 60 has a plurality of ejector pins 80A, 80B for releasing the seal member 30 from the movable die 60. The movable die 60 has, for example, four ejector pins 80A provided so as to be retractable in the second frame molding portion 64 and three ejector pins 80B provided so as to be retractable in the runner portion 70.

[0049] The four ejector pins 80A are provided at intervals from one another in the circumferential direction of the second frame molding portion 64. The ejector pins 80A are arranged in a portion of the second frame molding portion 64 excluding the portion that molds the connection portion 31b.

[0050] When the seal member 30 is molded, the surface of the second frame molding part 64 and the tip surface of each ejector pin 80A are flush with each other. That is, the tip surface of each ejector pin 80A forms a part of the cavity that molds the frame part 31.

[0051] The three ejector pins 80B are provided so as to be able to protrude and retract from the bottom surfaces of the three runners 73. The ejector pins 80B are disposed in positions on the runners 73 closer to the second frame molding portion 64 than the recessed portion 71. When molding the seal member 30, each ejector pin 80B retracts to the opposite side of the fixed mold 50 from the bottom surfaces of the runners 73.

[0052] (Method of manufacturing the seal member 30) The method for manufacturing the seal member 30 includes a molding step of molding the seal member 30 and a demolding step of releasing the seal member 30 from the movable mold 60.

[0053] (molding process) 7, in the molding process, first, the fixed mold 50 and the movable mold 60 are clamped together, and then heated thermoplastic resin R is injected between the fixed mold 50 and the movable mold 60 through the sprue 51a. Thereafter, the fixed mold 50 and the movable mold 60 are cooled, thereby solidifying the resin R filled between the fixed mold 50 and the movable mold 60.

[0054] In the molding process, the frame portion 31 is molded by filling a cavity formed between the first frame molding portion 54 and the second frame molding portion 64 with resin R through a runner portion 70 connected to the sprue 51a. Also, the comb-tooth portion 32 is molded by filling a cavity C (see FIG. 6) formed between the first comb-tooth molding portion 55 and the second comb-tooth molding portion 65 with resin R. Also, the linking portion 38 (see FIG. 8) that links the inner edges of the frame portion 31 is molded by filling a cavity formed between the first frame molding portion 54 and the runner portion 70 with resin R.

[0055] (Mold release process) 8, in the demolding step, first, the fixed mold 50 and the movable mold 60 are opened. Then, the ejector pins 80A, 80B are caused to protrude from the movable mold 60 toward the fixed mold 50, and the ejector pins 80A, 80B push the sealing member 30 out of the movable mold 60. This causes the sealing member 30 to be demolded from the movable mold 60.

[0056] In the demolding step, the frame portion 31 is pushed out from the second frame molding portion 64 by the ejector pins 80A, and the connecting portion is pushed out from the runner portion by the ejector pins 80B.

[0057] Although not shown in the drawings, after the demolding step, a cutting step is performed in which the connecting portion 38 of the seal member 30 is cut from the frame portion 31. The operation of this embodiment will be described.

[0058] In the molding process, the comb-tooth portion 32 is molded by injecting resin R into a cavity C formed by the first ridges 56, the first grooves 57, the second ridges 66, and the second grooves 67. The cavity C is formed by the first protrusions 56 contacting the second bottom surfaces 67a of the second grooves 67 and the second protrusions 66 contacting the first bottom surfaces 57a of the first grooves 57. This reduces the difference between the proportion of the cavity C occupied by the first comb-tooth-forming portions 55 and the proportion of the second comb-tooth-forming portions 65. This reduces the difference between the contact area of ​​the first comb-tooth-forming portions 55 and the contact area of ​​the second comb-tooth-forming portions 65 in the comb-tooth portion 32. This prevents the comb-tooth portion 32 from biting into the second comb-tooth-forming portions 65, and ultimately prevents the seal member 30 from biting into the movable mold 60.

[0059] The effects of this embodiment will be described. (1-1) The manufacturing method of the seal member 30 includes a molding step and a demolding step. In the molding step, the seal member 30 is molded by injecting resin R between a fixed mold 50 having first ridges 56 and first grooves 57 formed therein and a movable mold 60 having second ridges 66 and second grooves 67 formed therein. In the molding step, the comb-tooth portion 32 is molded by injecting resin R into a cavity C formed by the first ridges 56, the first grooves 57, the second ridges 66, and the second grooves 67. In the demolding step, with the fixed mold 50 and the movable mold 60 open, the seal member 30 is pushed out by ejector pins 80A and 80B that are provided so as to be retractable into the movable mold 60, thereby releasing the seal member 30 from the movable mold 60.

[0060] According to this method, the above-described effect is achieved, and therefore, by pushing out the seal member 30 with the ejector pins 80A, 80B in the mold releasing step, the seal member 30 can be smoothly released from the mold. Therefore, the mold releasability of the seal member 30 can be improved.

[0061] (1-2) The manufacturing apparatus 40 for the seal member 30 includes a fixed mold 50 provided with first ridges 56 and first grooves 57, and a movable mold 60 provided with second ridges 66 and second grooves 67. The movable mold 60 is provided with retractable ejector pins 80A, 80A that push out the seal member 30. When the fixed mold 50 and the movable mold 60 are clamped together, the first ridges 56, first grooves 57, second ridges 66, and second grooves 67 form a cavity C for molding the comb-tooth portion 32.

[0062] According to this configuration, the same effect as that described above is achieved, and therefore, by pushing out the seal member 30 with the ejector pins 80A, 80B, the seal member 30 can be smoothly released from the mold. Therefore, the releasability of the seal member 30 can be improved.

[0063] Second Embodiment Hereinafter, a second embodiment of a method and apparatus for manufacturing a sealing member for a fuel cell will be described with reference to FIGS. 9 to 15, focusing on differences from the first embodiment.

[0064] In the second embodiment, the same symbols are used for the same configurations as in the first embodiment, and for configurations corresponding to the first embodiment, the symbol "2**" is used, which is the symbol "**" in the first embodiment plus "200", thereby omitting redundant explanations.

[0065] As shown in FIG. 9, the manufacturing apparatus 240 includes a fixed mold 250 and a movable mold 260 that is configured to be able to advance and retreat relative to the fixed mold 250. As shown in FIG. 10, the fixed mold 250 has a fixed-side plate 251 and a cavity block 252 housed in the fixed-side plate 251.

[0066] The cavity block 252 has a first molding surface 253 that molds one surface in the thickness direction of the seal member 30. The first molding surface 253 has a first frame molding portion 254 that molds the connecting portion 38 and the frame portion 31 of the seal member 30, and a first comb-tooth molding portion 255 that molds the comb-tooth portion 32.

[0067] The first frame molding portion 254 has a molding recess 254 a for molding the protrusion 36 , and a communication hole 254 b that penetrates the cavity block 252 and communicates with the sprue 251 a of the fixed side plate 251 .

[0068] The first comb-tooth forming portion 255 has a first flat portion 255a that is flat. The first flat portion 255a comes into contact with a tip surface 266a of a protrusion 266, which will be described later. As shown in FIG. 11, the movable mold 260 has a movable plate 261 and a core block 262 housed in the movable plate 261.

[0069] The core block 262 has a second molding surface 263 that molds the other surface in the thickness direction of the seal member 30. The second molding surface 263 has a second frame molding portion 264 that molds the frame portion 31, a second comb-tooth molding portion 265 that molds the comb-tooth portion 32, and a runner portion 270 that is continuous with the second frame molding portion 264 and molds the connecting portion 38.

[0070] The second comb-tooth forming portion 265 has ridges 266 and grooves 267 arranged alternately in the circumferential direction of the second frame forming portion 264 . 13, the width of the ridge 266 is approximately the same as the width of the groove 267. The ridge 266 has a tip surface 266a that contacts the first flat portion 255a. The groove 267 has a bottom surface 267a that faces the first flat portion 255a. The tip surface 266a and the bottom surface 267a are flat.

[0071] 11, the second comb-tooth-forming portion 265 has a second flat portion 265a having a flat shape. The grooves 267 are formed in the second flat portion 265a. The protrusions 266 are formed between two adjacent grooves 267 in the second flat portion 265a. In other words, the tip surfaces 266a of the protrusions 266 are part of the second flat portion 265a.

[0072] 13, when the fixed die 250 and the movable die 260 are clamped together, the protruding end surface 266a of the ridge 266 comes into contact with the first flat portion 255a. As a result, a cavity C2 in which the comb teeth portion 32 is molded is formed between the first comb teeth forming portion 255 and the second comb teeth forming portion 265.

[0073] As shown in FIG. 11, the runner portion 270 has a recess 271 that communicates with the communication hole 254b of the cavity block 252, and three runners 273 that branch off and extend from the recess 271.

[0074] The core block 262 includes an outer molded portion 290 and an inner molded portion 291 that are separated from each other. The outer molding part 290 is adjacent to the movable-side plate 261 and has an annular shape. The outer molding part 290 molds the outer periphery of the seal member 30, including the tip ends of the comb-tooth part 32. The outer molding part 290 molds the range of the comb-tooth part 32 that is closer to the tip end than the central part in the length direction of the comb-tooth part 32. The outer molding part 290 is configured to be able to advance and retreat with respect to the inner molding part 291 in the advance and retreat direction of the movable mold 260 relative to the fixed mold 250.

[0075] The inner mold portion 291 is configured as a separate body from the outer mold portion 290. The inner mold portion 291 has a first portion 292 and a second portion 293 configured by being separated from each other. The first portion 292 is annular and is located on the inner circumferential side of the outer molding portion 290. The first portion 292 forms a portion of the seal member 30 that is on the inner circumferential side of the outer circumferential portion. More specifically, the first portion 292 forms a middle portion of the seal member 30 excluding the outer circumferential portion and the inner circumferential portion of the seal member 30.

[0076] The second portion 293 is located on the inner circumferential side of the first portion 292. The second portion 293 forms the inner circumferential portion of the seal member 30 and the connecting portion . The second frame molding portion 264 and the second comb tooth molding portion 265 are configured by an outer molding portion 290 and an inner molding portion 291. The runner portion 270 is configured by a second portion 293. The second frame molding portion 264 has the same configuration as the second frame molding portion 64 of the first embodiment. The runner portion 270 has the same configuration as the runner portion 70 of the first embodiment.

[0077] The movable die 260 has a plurality of ejector pins 280A, 280B for releasing the seal member 30 from the movable die 260. The movable die 260 has, for example, four ejector pins 280A provided so as to be able to appear and disappear in the second frame molding portion 264, and three ejector pins 280B provided so as to be able to appear and disappear in the runner portion 270. The four ejector pins 280A are provided so as to be able to appear and disappear in the first portion 292. The three ejector pins 280B are provided so as to be able to appear and disappear in the second portion 293.

[0078] As shown in FIG. 9, the movable mold 260 includes a first plate 300 adjacent to the movable-side plate 261 and a second plate 310 adjacent to the first plate 300. The first plate 300 is adjacent to the movable plate 261 in the advance / retract direction. The first plate 300 has a frame shape. The inner molded portion 291 penetrates the first plate 300.

[0079] The second plate 310 is located on the opposite side of the first plate 300 from the movable plate 261 in the advancing / retreating direction.

[0080] A plurality of springs 320 are provided between the first plate 300 and the second plate 310. The first plate 300 is constantly biased toward the fixed mold 250 by the springs 320. Therefore, when the fixed mold 250 and the movable mold 260 are opened, the biasing force of the springs 320 moves the first plate 300 together with the movable-side plate 261 toward the fixed mold 250. As a result, as shown in FIG. 12 , the outer mold portion 290 projects toward the fixed mold 250 relative to the inner mold portion 291.

[0081] (Method of manufacturing the seal member 30) The manufacturing method of the seal member 30 includes a molding step of molding the seal member 30, a pressing step of pressing the outer periphery of the seal member 30 toward the fixed die 250, and a demolding step of releasing the seal member 30 from the movable die 260. The molding step, pressing step, and demolding step are performed in this order.

[0082] (molding process) In the molding process, first, the fixed mold 250 and the movable mold 260 are clamped together, and then heated thermoplastic resin R is injected through the sprue 251a into the space between the fixed mold 250 and the movable mold 260. Thereafter, the fixed mold 250 and the movable mold 260 are cooled, thereby solidifying the resin R filled between the fixed mold 250 and the movable mold 260.

[0083] In the molding process, the frame portion 31 is molded by filling a cavity formed between the first frame molding portion 254 and the second frame molding portion 264 with resin R through a runner portion 270 connected to the sprue 251a. Also, the comb-tooth portion 32 is molded by filling a cavity C2 (see FIG. 13) formed between the first comb-tooth molding portion 255 and the second comb-tooth molding portion 265 with resin R. Also, the linking portion 38 (see FIG. 15) that links the inner edges of the frame portion 31 is molded by filling a cavity formed between the first frame molding portion 254 and the runner portion 270 with resin R.

[0084] (Pressing process) 14, in the pressing step, the fixed mold 250 and the movable mold 260 are opened, and the outer molded portion 290 moves toward the fixed mold 250 due to the negative force of the spring 320 (see FIG. 9). As a result, the outer molded portion 290 protrudes toward the fixed mold 250 relative to the inner molded portion 291. As a result, the outer periphery of the seal member 30 is pressed toward the fixed mold 250. In this way, the portion including the outer periphery of the seal member 30 is partially released from the outer molded portion 290 and the first portion 292.

[0085] (Mold release process) 15, in the demolding step, the ejector pins 280A and 280B are caused to protrude from the movable mold 260 toward the fixed mold 250, and the ejector pins 280A and 280B push the seal member 30 out of the movable mold 260. As a result, the seal member 30 is demolded from the movable mold 260.

[0086] In the demolding step, the frame portion 31 is pushed out from the second frame molding portion 264 by the ejector pins 280A, and the connecting portion 38 is pushed out from the runner portion 270 by the ejector pins 280B.

[0087] Although not shown in the drawings, after the demolding step, a cutting step is performed in which the connecting portion 38 of the seal member 30 is cut from the frame portion 31. The operation of this embodiment will be described.

[0088] In the pressing step, the outer periphery of the seal member 30 formed in the molding step is pressed toward the fixed mold 250 by the outer molding part 290. As a result, a part of the seal member 30 including the comb-tooth portion 32 is released from the first part 292 of the inner molding part 291. Thereafter, in the demolding step, the seal member 30 is pushed out by the ejector pins 280A and 280B, and the entire seal member 30 is released from the movable mold 260.

[0089] (2-1) The manufacturing method of the seal member 30 includes a molding step, a pressing step, and a demolding step. In the molding step, the seal member 30 is molded by injecting resin R between a fixed mold 250 and a movable mold 260 having an outer mold portion 290 and an inner mold portion 291. In the pressing step, with the fixed mold 250 and the movable mold 260 in a mold-open state, the outer mold portion 290 is protruded toward the fixed mold 250 to press the outer periphery of the seal member 30 toward the fixed mold 250. In the demolding step, the seal member 30 is released from the movable mold 260 by pushing out the seal member 30 using ejector pins 280A and 280B that are provided so as to be able to retract into and out of the inner mold portion 291.

[0090] According to this method, the above-mentioned effect is achieved, and the seal member 30 can be smoothly released by gradually releasing the comb-tooth portion 32 from the movable die 260. Therefore, the releasability of the seal member 30 can be improved.

[0091] (2-2) The manufacturing apparatus 240 includes a fixed mold 250 and a movable mold 260 having an outer molding portion 290 and an inner molding portion 291. The outer molding portion 290 is configured to be able to advance and retreat relative to the inner molding portion 291 in the advance and retreat direction of the movable mold 260 relative to the fixed mold 250. Ejector pins 280A and 280B that push out the seal member 30 are provided in the inner molding portion 291 so as to be able to protrude and retreat.

[0092] According to this configuration, after the fixed mold 250 and the movable mold 260 are opened, the outer molding portion 290 is moved toward the fixed mold 250 relative to the inner molding portion 291, whereby the outer peripheral portion of the seal member 30 is pressed toward the fixed mold 250 by the outer molding portion 290. As a result, a portion of the seal member 30, including the comb-tooth portion 32, is released from the inner molding portion 291. Thereafter, the ejector pins 280A and 280B press the seal member 30 toward the fixed mold 250, whereby the entire seal member 30 is released from the movable mold 260. In this way, the comb-tooth portion 32 can be released from the movable mold 260 in stages. Therefore, the releasability of the seal member 30 can be improved.

[0093] <Example of change> This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0094] In the second embodiment, the inner molded portion 291 may be formed by integrating the first portion 292 and the second portion 293 together. In the second embodiment, the outer molding portion 290 may be formed over a range including the central portion of the comb-tooth portion 32 in the length direction.

[0095] In the second embodiment, instead of the spring 320, the outer molding portion 290 may be protruded toward the fixed mold 250 by, for example, an electric actuator. In the first embodiment, when the cavity C is formed, the first ridges 56 and the second ridges 66 do not have to be arranged alternately. The cavity C may be formed, for example, by accommodating a plurality of second ridges 66 inside the first grooves 57. Alternatively, the cavity C may be formed by accommodating a plurality of first ridges 56 inside the second grooves 67.

[0096] In the first embodiment, the shapes of the first ridges 56, the first grooves 57, the second ridges 66, and the second grooves 67 may be changed as appropriate depending on the shape of the comb-tooth portions 32. In each embodiment, the number and arrangement of the ejector pins may be changed as appropriate. [Explanation of symbols]

[0097] C, C2...cavity R…Resin 20...Separator 21...Manifold 22...Flow path 30...Sealing member 31...Frame 32... Comb teeth 37…Communication path 40,240…Manufacturing equipment 50,250…Fixed type 56...First protrusion 56a...First end face 57…1st groove 57a...1st bottom surface 60,260…Movable type 66...Second ridge 66a...Second end face 67…Second groove 67a…Second bottom surface 80A, 80B, 280A, 280B...Ejector pin 290...Outer molding part 291…Inner molding part

Claims

1. A method for manufacturing a sealing member for a fuel cell, which is attached to a separator for the fuel cell having a plurality of manifolds for supplying or discharging a fluid and a flow path through which the fluid flows, comprising: the seal member has an annular frame portion attached to the manifold and a comb-tooth portion extending in a cantilevered manner from the frame portion toward the flow path, and the comb-tooth portion forms, together with the separator, a communication passage that connects the manifold and the flow path; a molding step of molding the sealing member by injecting resin between a fixed mold in which first protrusions and first grooves are alternately arranged and a movable mold in which second protrusions that contact bottom surfaces of the first grooves and second grooves that contact tip surfaces of the first protrusions are alternately arranged; a demolding step of, after the molding step, releasing the seal member from the movable die by pushing out the seal member with an ejector pin provided so as to be able to retract into the movable die while the fixed die and the movable die are in a mold-open state, In the molding step, the comb-tooth portion is molded by injecting the resin into a cavity formed by the first protrusions, the first grooves, the second protrusions, and the second grooves. A method for manufacturing a sealing member for a fuel cell.

2. 1. An apparatus for manufacturing a sealing member for a fuel cell, the sealing member being attached to a separator for the fuel cell having a plurality of manifolds for supplying or discharging a fluid and a flow path through which the fluid flows, the apparatus comprising: the seal member has an annular frame portion attached to the manifold and a comb-tooth portion extending in a cantilevered manner from the frame portion toward the flow path, and the comb-tooth portion forms, together with the separator, a communication passage that connects the manifold and the flow path; a fixed mold in which first protrusions and first grooves are alternately arranged; a movable mold in which second ridges contacting the bottom surfaces of the first grooves and second grooves contacting the tip surfaces of the first ridges are alternately arranged, The movable mold is provided with an ejector pin that can protrude and retract to push out the seal member, When the fixed mold and the movable mold are clamped together, a cavity for molding the comb-tooth portion is formed by the first protrusions, the first grooves, the second protrusions, and the second grooves. Manufacturing equipment for sealing materials for fuel cells.

3. A method for manufacturing a sealing member for a fuel cell, which is attached to a separator for the fuel cell having a plurality of manifolds for supplying or discharging a fluid and a flow path through which the fluid flows, comprising: the seal member has an annular frame portion attached to the manifold and a comb-tooth portion extending in a cantilevered manner from the frame portion toward the flow path, and the comb-tooth portion forms, together with the separator, a communication passage that connects the manifold and the flow path; a molding process of molding the seal member by injecting resin between a fixed mold and a movable mold having an outer molding portion that molds an outer periphery of the seal member and an inner molding portion that is configured separately from the outer molding portion and molds a portion of the seal member that is more inward than the outer periphery; a pressing step of pressing the outer circumferential portion toward the fixed mold by projecting the outer molding portion toward the fixed mold in a state in which the fixed mold and the movable mold are opened after the molding step; and a mold releasing step of releasing the seal member from the movable mold by pushing out the seal member using an ejector pin that is provided so as to be able to appear and disappear from the inner molding portion after the pressing step. A method for manufacturing a sealing member for a fuel cell.

4. 1. An apparatus for manufacturing a sealing member for a fuel cell, the sealing member being attached to a separator for the fuel cell having a plurality of manifolds for supplying or discharging a fluid and a flow path through which the fluid flows, the apparatus comprising: the seal member has an annular frame portion attached to the manifold and a comb-tooth portion extending in a cantilevered manner from the frame portion toward the flow path, and the comb-tooth portion forms, together with the separator, a communication passage that connects the manifold and the flow path; Fixed type and a movable mold having an outer molding portion that molds an outer peripheral portion of the seal member, and an inner molding portion that is configured separately from the outer molding portion and that molds a portion of the seal member that is located more inward than the outer peripheral portion, the outer molding portion is configured to be movable forward and backward relative to the inner molding portion in a direction in which the movable mold advances and retreats relative to the fixed mold, An ejector pin that pushes out the seal member is provided in the inner molded portion so as to be able to protrude and retract. Manufacturing equipment for sealing materials for fuel cells.

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