Insert molding die

Abstract

To provide an insert molding die that can suppress damage to an insert part.SOLUTION: There is provided an insert molding die for insert-molding a gasket 120 into an insert part 110 having a flat plate-shaped portion, which comprises: a lower die 20 having a placement part for placing the insert part 110; and an upper die 30 having a cavity 31 for molding the gasket 120. The upper die 30 is provided with a pressing plate 40 having a pressing surface that presses the flat plate-shaped portion of the insert part 110, and a biasing member 41 that biases the pressing plate 40 toward the insert part 110.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an insert molding die.

Background Art

[0002] In a solid polymer fuel cell, a structure in which MEAs and separators are alternately laminated is used. And in a fuel cell, a gasket is provided to prevent leakage of fuel gas, oxidant gas, coolant, etc. Conventionally, in order to improve the workability when assembling a fuel cell, a technique of integrally providing a gasket to an MEA by insert molding is known. Referring to FIG. 5, an insert molding die according to the prior art will be described. FIG. 5 is an explanatory diagram of molding by a die according to the prior art.

[0003] FIG. 5(a) is a cross-sectional view of an insert molding die according to the prior art 1. This die includes a lower die 520 having an arrangement portion for arranging an insert part 110 having an MEA, and an upper die 530 having a cavity for molding a gasket 120. In the die configured as such, after arranging the insert part 110 in the lower die 520, mold clamping is performed, and by filling the cavity of the upper die 530 with a molding material, the gasket 120 can be integrally provided to the insert part 110. Thereafter, by opening the die, a molded product integrally provided with the insert part 110 and the gasket 120 can be taken out.

[0004] However, if the releasability of the gasket 120 is poor, when the die is opened, a portion released from the upper die 530 and a non-released portion occur, and shear stress acts on the insert part 110 (see X in the figure). The MEA is composed of an electrolyte membrane and a gas diffusion layer, and has a property of being easily damaged. Therefore, when shear stress acts on the MEA, there is a concern that it may be damaged. Also, if the gasket 120 is molded in a state where the insert part 110 arranged in the lower die is bent, the arrangement accuracy of the gasket 120 with respect to the insert part 110 will decrease.

[0005] Figure 5(b) is a cross-sectional view of a conventional insert molding die according to prior art 2. This die comprises a lower mold 520 having a placement section for insert parts 110 having an MEA, and an upper mold 530A having a cavity for molding a gasket 120. In this die, an ejector pin 531 is provided on the upper mold 530A. This makes it possible to release the entire gasket 120 from the upper mold 530A almost simultaneously when opening the mold. However, if such a configuration is adopted, stress is concentrated on the part of the insert part 110 that is pressed by the ejector pin 531 (see Y in the figure), raising concerns about damage to the MEA.

[0006] Furthermore, the above concerns apply not only when a gasket is integrally provided by insert molding on an MEA (Metal Energy Acquisition) installed in a fuel cell, but also when a gasket is integrally provided by insert molding on a component that is easily damaged. In addition, the same concerns apply not only when molding a gasket, but also when molding a molded body made of resin material or the like by insert molding, if the insert component is a component that is easily damaged. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2003-71871 [Patent Document 2] Japanese Patent Publication No. 2004-268456 [Patent Document 3] Japanese Patent Publication No. 2016-7755 [Overview of the project] [Problems that the invention aims to solve]

[0008] The present invention provides an insert molding die that can suppress damage to insert components. [Means for solving the problem]

[0009] To solve the above problems, the present invention employs the following means.

[0010] In other words, the insert molding die of the present invention is an insert molding die for integrally forming a molded body on an insert part having a flat plate-shaped portion, comprising: a lower die having a placement portion for arranging the insert part; and an upper die having a cavity for forming the molded body. ,before A pressing plate having a pressing surface for pressing the flat plate portion, and a biasing member for biasing the pressing plate toward the insert part. Only the aforementioned upper mold The pressing plate is provided at a position away from the cavity and is not affected by the material filling the cavity.

[0011] According to the present invention, the planar portion of the insert component is pressed by the pressing surface of a pressing plate that is biased by a biasing member. This suppresses the deflection of the insert component during molding, and allows the entire molded body to be released from the upper mold almost simultaneously when the mold is opened.

[0012] The pressing plate is preferably configured to press the insert component from the middle of the mold clamping process between the lower and upper molds until the molds are fully clamped, and to continue pressing the insert component from the clamped state until the molds are partially opened.

[0013] This allows the insert part to be pressed against the lower mold without bending before the mold clamping is complete, and to remain pressed against the lower mold until the molded body is released.

[0014] The biasing force exerted by the biasing member should be greater than the release force that separates the molded body from the upper mold.

[0015] This allows the insert part to be pressed more securely against the lower mold until the molded body is released.

[0016] The insert component is provided in a fuel cell, and includes an electrolyte membrane, gas diffusion layers provided on both surfaces of the electrolyte membrane respectively, and a reinforcing body provided around the gas diffusion layers. It is preferable that the gas diffusion layer is pressed by the pressing plate, and the gasket as the molded body is integrally molded on the surface of the reinforcing body.

[0017] In addition, the above configurations can be adopted in combination as much as possible.

Advantages of the Invention

[0018] As described above, according to the present invention, damage to the insert component can be suppressed.

Brief Description of the Drawings

[0019] [Figure 1] FIG. 1 is an explanatory view of an insert molded product molded by a mold according to an embodiment of the present invention. [Figure 2] FIG. 2 is an explanatory view of a molding procedure by a mold according to an embodiment of the present invention. [Figure 3] FIG. 3 is an explanatory view of a molding procedure by a mold according to an embodiment of the present invention. [Figure 4] FIG. 4 is an explanatory view of a molding procedure by a mold according to an embodiment of the present invention. [Figure 5] FIG. 5 is an explanatory view of molding by a mold according to the prior art.

Modes for Carrying Out the Invention

[0020] Hereinafter, with reference to the drawings, modes for carrying out this invention will be exemplarily and specifically described based on examples. However, dimensions, materials, shapes, relative arrangements, etc. of the component parts described in this example are not intended to limit the scope of this invention only to those, unless specifically described otherwise.

[0021] (Example) Referring to Figures 1 to 4, an insert molding die according to an embodiment of the present invention will be described. In this embodiment, as an example, a case in which a fuel cell component is molded by insert molding is shown.

[0022] <Fuel cell> Figure 1(a) shows a simplified cross-sectional view of a fuel cell, and Figure 1(b) shows a plan view of an insert molded product 100 obtained by an insert molding die according to an embodiment of the present invention. The cross-sectional view of the insert molded product 100 in Figure 1(a) corresponds to the AA cross-sectional view in Figure 1(b).

[0023] Generally, fuel cells are configured as cell stacks consisting of multiple single cells. Figure 1(a) shows a cross-sectional view of a part of a single cell 10. The cell stack is configured such that MEAs (Membrane Electrode Assembly), which consist of an electrolyte membrane 111 and gas diffusion layers 112 provided on both sides of the electrolyte membrane 111, and separators 200 are stacked alternately. In the separators 200, a channel (not shown) is formed on the surface facing the gas diffusion layer 112 through which fuel gas, oxidizer gas, coolant, etc., flow.

[0024] In this embodiment, the insert component 110 in insert molding is composed of the above-mentioned MEA and a reinforcing body 113 integrally provided around the MEA. A single cell 10 is formed by this insert component 110 and a pair of separators 200 provided on both sides thereof. Figure 1(a) shows only one single cell 10.

[0025] The reinforcing body 113 is made of a resin film or the like that supports both sides of the electrolyte membrane 111. The electrolyte membrane 111 can be reinforced by this reinforcing body 113. Suitable materials for the resin film include resin materials such as PEN (polyethylene naphthalate) and PI (polyimide).

[0026] A gasket 120 is provided between the reinforcing body 113 and the separator 200 to prevent leakage of fuel gas, oxidizer gas, coolant, etc. This gasket 120 is integrally provided on the surface of the reinforcing body 113. Suitable materials for the gasket 120 include rubber materials such as EPDM (ethylene propylene rubber) and VMQ (vinyl methyl silicone rubber). In a cell stack, manifolds are provided on the separator and reinforcing body to supply fuel gas, oxidizer gas, coolant, etc. to each cell, but these are omitted in Figure 1(b), and the insert molded product 100 is shown in a simplified manner. The gasket 120 is provided so as to surround the region in the separator 200 where the flow path is formed and the periphery of the manifold.

[0027] <Mold and insert molding procedure> Referring to Figures 2 to 4, the insert molding die and insert molding procedure according to this embodiment will be described. In this embodiment, an insert is used on one side of the insert part 110. The gasket 120 is formed as a molded body by insert molding, and then the gasket 120 is formed on the opposite side of the insert part 110 by insert molding. Figures 2 and 3 show the mold and insert molding procedure in the former, and Figure 4 shows the mold and insert molding procedure in the latter. In all figures, the mold is shown in a simplified cross-sectional view.

[0028] Referring to Figures 2 and 3, the mold and insert molding procedure for forming a gasket 120 on one side of an insert part 110 by insert molding will be described. The insert molding mold comprises a lower mold 20 having a placement section for positioning the insert part 110, and an upper mold 30 having a cavity 31 for forming the gasket 120. A recess 21 for positioning the gas diffusion layer 112 of the insert part 110 is provided in the center of the lower mold 20. The reinforcing body 113 of the insert part 110 is configured to be placed on the surface surrounding this recess 21. The placement section of the insert part 110 is formed by this recess 21 and the surface surrounding the recess 21.

[0029] The upper mold 30 is provided with a pressing plate 40 having a pressing surface that presses against the flat portion (gas diffusion layer 112) of the insert component 110, and a biasing member 41 that biases the pressing plate 40 toward the insert component 110. In this embodiment, the pressing surface of the pressing plate 40 is configured to press against the entire surface of the gas diffusion layer 112. A coil spring or the like can be suitably used as the biasing member 41. One end of the biasing member 41 is fixed to a mounting hole 32 provided in the upper mold 30, and the other end is fixed to the pressing plate 40. The number of biasing members 41 can be appropriately set according to the dimensions of the insert component 110.

[0030] Figure 2(a) shows the mold in an open state with the insert component 110 positioned in a predetermined location on the lower mold 20. The pressing plate 40 is configured to press the insert component 110 from the middle of the mold clamping process between the lower mold 20 and the upper mold 30 until the mold is fully clamped. That is, as the upper mold 30 is brought closer to the lower mold 20 from the state shown in Figure 2(a), the planar pressing surface of the pressing plate 40 comes into contact with the gas diffusion layer 112 of the insert component 110. Subsequently, as the biasing force from the biasing member 41 increases (as the coil spring compresses), the upper mold 30 moves further closer to the lower mold 20, and the surface around the cavity 31 on the upper mold 30 comes into contact with the reinforcing body 113 of the insert component 110, completing the mold clamping process.

[0031] After mold clamping, gasket material is filled into the cavity 31, and the gasket 120 is integrally molded onto the insert part 110. Figure 2(b) shows the state in which the gasket 120 has been integrally molded onto one side of the insert part 110.

[0032] The pressing plate 40 is configured to press the insert component 110 from the mold clamped state until the mold is partially opened. Figure 3(a) shows the state during the opening of the mold after insert molding. As shown in the figure, the insert component 110 is pressed by the pressing plate 40 from the mold clamped state until the mold is partially opened, causing the gasket 120 to be released from the upper mold 30 almost simultaneously in its entirety. Furthermore, by configuring the biasing force of the biasing member 41 to be greater than the release force that separates the gasket 120 from the upper mold 30, it becomes possible to more reliably release the entire gasket 120 from the upper mold 30 almost simultaneously.

[0033] Subsequently, by further separating the upper mold 30 from the lower mold 20 and opening the mold, the pressing plate 40 separates from the insert part 110, allowing the insert part 110, with the gasket 120 integrally molded on one side, to be removed.

[0034] Referring to Figure 4, the mold and insert molding procedure for forming a gasket 120 on the opposite side of the insert part 110 by insert molding will be described. The mold for insert molding also includes a lower mold 20A having a placement area for the insert component 110, and an upper mold 30 having a cavity 31 for forming the gasket 120. A recess 21 for arranging the gas diffusion layer 112 of the insert component 110 is provided in the center of the lower mold 20A. The reinforcing body 113 of the insert component 110 is configured to be placed on the surface surrounding this recess 21. In the case of this lower mold 20A, a recess 22 for arranging the gasket 120 formed by the insert molding described above is also provided at a distance from the recess 21. As described above, in the case of the lower mold 20A, the placement area for the insert component 110 is formed by the recess 21, the surface surrounding the recess 21, and the recess 22. The upper mold 30 has been described with reference to Figures 2 and 3.

[0035] Figure 4(a) shows the insert part 110, with a gasket 120 integrally molded on one side, positioned in a predetermined location on the lower mold 20A with the mold open. As described above, the pressing plate 40 is configured to press the insert part 110 from the middle of the mold clamping process between the lower mold 20A and the upper mold 30 until the mold is fully clamped. The operation until the completion of mold clamping is as described above.

[0036] After mold clamping, gasket material is filled into the cavity 31, and the gasket 120 is integrally molded onto the side of the insert part 110 opposite to the side on which the gasket 120 has already been molded. Figure 4(b) shows the state in which the gasket 120 has been integrally molded onto both sides of the insert part 110, and the insert molded product 100 has been obtained. The operation from the state in which the mold is clamped until the mold is fully opened is as described above, so its explanation will be omitted.

[0037] <Advantages of the insert molding die according to this embodiment> In this embodiment of the insert molding die, the planar portion (gas diffusion layer 112) of the insert part 110 is pressed by the pressing surface of the pressing plate 40, which is biased by the biasing member 41. This prevents the insert part 110 from bending during molding. Therefore, the gasket 120 can be integrally provided on the insert part 110 with high precision at a desired position. Furthermore, when opening the mold, the entire gasket can be released from the upper mold 30 almost simultaneously. This prevents shear stress from acting on the insert part 110, thus preventing damage to the insert part 110.

[0038] Furthermore, in this embodiment, the pressing plate 40 is configured to press the insert component 110 from the middle of the mold clamping process between the lower mold 20 and the upper mold 30 until the mold is fully clamped, and to continue pressing the insert component 110 from the clamped state until the mold is partially opened. This allows the insert component 110 to be pressed against the lower mold 20 without bending before the mold clamping is complete, and to be pressed against the lower mold 20 until the gasket 120 is released.

[0039] Furthermore, if the biasing force provided by the biasing member 41 is greater than the release force required to release the gasket 120 from the upper mold 30, the insert component 110 can be pressed more reliably against the lower mold 20 until the gasket 120 is released.

[0040] In this embodiment, the case described is an insert molding die in which a gasket 120 is integrally provided by insert molding on an insert component 110 having an MEA provided in a fuel cell. However, the present invention is applicable to insert molding dies for integrally providing gaskets to various insert components. Furthermore, the present invention is not limited to cases where a gasket is formed by insert molding, but also applies to various insert components made of resin material, rubber material, etc., by insert molding. This invention is applicable to all insert molding dies used to form body parts. In particular, it can be suitably applied when the insert component is a material that is easily damaged. [Explanation of Symbols]

[0041] 10 single cells 20,20A lower mold 21,22 recess 30 Upper mold 31 Cavity 32 mounting holes 40 Pressing plate 41. Biasing member 100 Insert molded parts 110 Insert parts 111 Electrolyte membrane 112 Gas diffusion layer 113 Reinforcement 120 Gasket 200 Separators

Claims

1. An insert molding die for integrally forming a molded body with an insert part having a flat plate-shaped portion, A lower mold having a placement section for arranging the insert component, An upper mold having a cavity for forming the molded body, Equipped with, An insert molding die is characterized in that a pressing plate having a pressing surface for pressing the flat plate portion and a biasing member for biasing the pressing plate toward the insert part are provided only in the upper mold, and the pressing plate is provided at a position away from the cavity and unaffected by the material filling the cavity.

2. The insert molding die according to claim 1, characterized in that the pressing plate is configured to press the insert component from the middle of the clamping of the lower mold and the upper mold until the mold is fully clamped, and to press the insert component from the clamped state until the middle of the mold is opening.

3. The insert molding die according to claim 1 or 2, characterized in that the biasing force provided by the biasing member is greater than the release force that releases the molded body from the upper mold.

4. The aforementioned insert component is provided in a fuel cell and comprises an electrolyte membrane, gas diffusion layers provided on both sides of the electrolyte membrane, and a reinforcing body provided around the gas diffusion layer. The insert molding die according to claim 1, 2, or 3, characterized in that the gas diffusion layer is pressed by the pressing plate and the gasket, which is the molded body, is integrally formed on the surface of the reinforcing body.

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