Field of the Invention
The present invention relates to a method of manufacturing a plate with frame by using a metal mold, the plate being obtained by integrally molding a resin frame in an outer edge portion of a metal plate. The manufacturing method according to the present invention is used, for example, in a process of manufacturing a gasket (a plate integrated gasket) for a fuel cell, or is used in a process of manufacturing a general gasket (a plate integrated gasket).
Description of the Conventional Art
For example, in the case that a gasket made of a rubber-like elastic material is integrally molded in an outer edge portion of a metal separator for a fuel cell which serves as a metal plate, a rubber burr is generated in an outer peripheral portion of a molded product. As a result, a lot of man hour is required for a burr removing work. Therefore, in order to implement a countermeasure thereto, first of all there is carried out a procedure of integrally molding a resin frame 31 in an outer edge portion (a right end portion in the drawing) 22 of a metal separator 21, and next integrally molding a gasket 41 made of a rubber-like elastic material in an inner side of the resin frame 31 (an inner peripheral side, a left side in the drawing) while setting the resin frame 31 to a dam portion against the rubber burr generation, and as shown in
However, in the case of manufacturing according to the procedure, there is fear that the resin frame 31 falls away from the outer edge portion 22 of the metal separator 21 in a stage that the resin frame 31 is integrally molded in the outer edge portion 22 of the metal separator 21 (a stage that the gasket 31 made of the rubber-like elastic material is not molded yet) (a falling away direction is shown by an arrow X).
In order to prevent the fall-away, it is thought that a concavo-convex shape 23 having a lot of concavities and convexities formed side by side is provided in the outer edge portion 22 of the metal separator 21, and the resin frame 31 is integrally molded in the outer edge portion 22 of the metal separator 21 having the concavo-convex shape 23, as shown in
However, in the case of implementing the countermeasure, the following disadvantages can be thought.
More specifically, when the resin frame 31 is integrally molded in the outer edge portion 22 of the metal separator 21 having the concavo-convex shape 23, the metal separator 21 is set to a parting portion of a metal mold for molding the resin frame 31, and a resin molding material for molding the resin frame 31 is next injected into a metal mold cavity. Meanwhile, the metal separator 21 is an extremely thin plate owing to demand for a compact structure of a fuel cell in recent years, and tends to be deformed (plastically deformed) by an external force application due to thinness. Therefore, in the molded product obtained by integrally molding the resin frame 31 in the outer edge portion 22 of the metal separator 21 having the concavo-convex shape 23, the outer edge portion 22 of the metal separator 21 should be buried in the middle in a thickness direction of the resin frame 31 in a normal situation without deformation of the outer edge portion 22 of the metal separator 21 as shown in
The present invention is made by taking the above points into consideration, and an object of the present invention is to provide a method of manufacturing a plate with frame, the method being structured such that a resin frame is hard to fall away from an outer edge portion of a metal plate, and an amount of deformation can be held down even if any deformation is generated in the outer edge portion of the plate when the resin frame is integrally molded in the outer edge portion of the metal plate.
In order to solve the problem mentioned above, the following means are employed in the present invention.
More specifically, a method of manufacturing a plate with frame according to the present invention is a method of manufacturing a plate with frame by using a metal mold, the plate being obtained by integrally molding a resin frame in an outer edge portion of a metal plate, wherein the metal plate is provided with a concavo-convex shape for making the resin frame hard to fall away in the outer edge portion of the metal plate, the metal mold is provided with a cavity portion for molding the resin frame in a state in which the metal plate is set to the metal mold, and a gate portion for injecting a frame molding material into the cavity portion, the gate portion is constructed by a plurality of gate portions which are provided at positions facing to an outer edge thickness surface of the metal plate in a state of being set to the metal mold, and are arranged at positions conforming to arrangement of concave portions in the concavo-convex shape, and the plate with frame is manufactured by using the metal mold (claim 1). The plate is, for example, a metal separator for a fuel cell, and the frame is, for example, a resin frame which is integrally molded in the outer edge portion of the metal separator.
In the manufacturing method according to the present invention mentioned above, the metal plate is provided with the concavo-convex shape in the outer edge portion thereof. As a result, a contact area between the metal plate and the resin frame is greater when the resin frame is integrally molded in the outer edge portion of the metal plate, in comparison with the case that the concavo-convex shape is not provided. Therefore, the resin frame is hard to fall away from the outer edge portion of the metal plate.
The metal mold is provided with the cavity portion for molding the resin frame in the state in which the metal plate is set to the metal mold, and the gate portion for injecting the frame molding material into the cavity portion. Here, the gate portions are provided at the positions facing to the outer edge thickness surface of the metal plate, and are arranged at the positions conforming to the arrangement of the concave portions in the concavo-convex shape in the metal plate. As a result, the portion having the concave portions in the concavo-convex shape of the metal plate tend to be deformed under the influence of injecting pressure of a frame molding material when the frame molding material injecting pressure is applied from the gate portion to the outer edge portion of the metal plate. Here, since the portion having the concave portions in the metal plate is smaller in a protruding length protruding to a cavity inner portion in comparison with the portion having the convex portions (a length of a portion which is held in a cantilever manner in the metal mold is small), an amount of deformation can be made smaller even after the deformation under the influence of injecting pressure of a frame molding material. Therefore, it is possible to prevent the leading end of the outer edge portion from being exposed to the surface in relation to the resin frame due to the great deformation in the outer edge portion of the metal plate.
Further, a method of manufacturing a plate with frame according to the present invention is a method of manufacturing a plate with frame by using a metal mold, the plate being obtained by integrally molding a resin frame in an outer edge portion of a metal plate, wherein the metal plate is provided with a concavo-convex shape for making the resin frame hard to fall away in the outer edge portion of the metal plate, the metal mold is provided with a cavity portion for molding the resin frame in a state in which the metal plate is set to the metal mold, and a gate portion for injecting a frame molding material into the cavity portion, the gate portion is constructed by a plurality of gate portions which are provided at positions facing to an outer edge thickness surface of the metal plate in a state of being set to the metal mold, weld portions which the positioned between a plurality of gate portions and where flow of the frame molding materials meet together are set in the resin frame formed by the cavity portion, the metal mold is provided with a structure in which arrangement of the weld portions in the metal mold is conformed to arrangement of the concave portions in the concavo-convex shape in the metal plate in a state of being set to the metal mold, and the plate with frame is manufactured by using the metal mold (claim 2). The plate is, for example, the metal separator for the fuel cell, and the frame is, for example, the resin frame which is integrally molded in the outer edge portion of the metal separator.
In the manufacturing method according to the present invention mentioned above, the metal plate is provided with the concavo-convex shape in the outer edge portion thereof. As a result, a contact area between the metal plate and the resin frame is greater when the resin frame is integrally molded in the outer edge portion of the metal plate, in comparison with the case that the concavo-convex shape is not provided. Therefore, the resin frame is hard to fall away from the outer edge portion of the metal plate.
Further, the metal plate is larger in its peripheral length in comparison with its thickness. Accordingly, in connection with provision of a plurality of gate portions in peripheral direction in the metal mold, the weld portions where the flow of the frame molding materials meet together are set in the resin frame molded in the cavity portion so as to be positioned between a plurality of gate portions. However, a pressure (a combined flow pressure) caused by the materials meeting together is generated in the weld portions, and the combined flow pressure acts on the outer edge portion of the metal plate. In association with this, in the present invention, the weld portions are arranged at the positions which conform to the arrangement of the concave portions in the concavo-convex shape in the metal plate. As a result, the portion having the concave portions in the concavo-convex shape of the metal plate tend to be deformed under the influence of the combined flow pressure when the combined flow pressure is applied to the outer edge portion of the metal plate. Here, since the portion having the concave portions in the metal plate is smaller in a protruding length protruding to a cavity inner portion in comparison with the portion having the convex portions (a length of a portion which is held in a cantilever manner in the metal mold is small), an amount of deformation can be made smaller even after the deformation under the influence of injecting pressure of a frame molding material. Therefore, it is possible to prevent a matter that the outer edge portion of the metal plate is greatly deformed and the leading end of the outer edge portion is exposed to the surface in relation to the resin frame from being generated.
Further, it is thought that the influence of injecting pressure of a frame molding material acting on the metal plate is reduced by enlarging the width of the resin frame molded by the metal mold in the portion including the weld portion in comparison with the other portions so as to set a circumferentially partly frame width enlargement portion in the resin frame.
Therefore, according to the present invention, the resin frame is hard to fall away from the outer edge portion of the metal plate. Further, even if the deformation is generated in the plate outer edge portion when the resin frame is integrally molded in the outer edge portion of the metal plate, it is possible to hold down the amount of deformation.
The following embodiments are included in the present invention.
(1) The rubber burr is generated in the outer peripheral portion when rubber molding the separator integrated gasket obtained by vulcanizing the rubber in the metal separator, and a lot of man hour is required for the burr removing work. As a result, the generation of the rubber burr can be held down by molding the resin frame in the outer peripheral portion of the metal separator. On the other hand, there is a case that an insulation performance which is a function in a normal situation can not be secured due to the deformation of the metal separator itself when molding the outer peripheral resin frame.
(2) The outer peripheral resin frame is formed into a concavo-convex shape in a whole periphery of the metal separator outer peripheral portion for suppressing a falling out after the molding. However, since it is necessary to make the separator for the fuel cell thin, the thickness of the resin frame must be thinned. Therefore, it is necessary to arrange a plurality of cold gates over a whole periphery in the metal mold for securing a resin fluidity when molding the resin. Further, the deformation in the outer periphery of the metal separator is greatly affected by the resin flow since it is generated at the time of resin molding, and is frequently generated in the cold gate and the weld portion, and the deformation is under the influence of the flow at the time of resin molding.
(3) In the present invention, both or one of the cold gate and the weld portion is arranged in the concave portion in the outer periphery of the metal separator.
(4) It is assumed that the flow influence at the time of resin molding is greater than the other sections. The amount of deformation is smaller due to the influence of the dimensional shape in relation to the convex portion even in the case that the deformation is generated at the section, by arranging both or one of the cold gate and the weld portion, where deformation generation frequency is actually higher, in the concave portion in the outer periphery of the metal separator. As a result, it is possible to reduce the possibility that a fixed level or more deformation is generated as a whole.
Next, a description will be given to embodiments according to the present invention with reference to the accompanying drawings.
In a manufacturing method according to the embodiment, a plate 11 with frame shown in
The metal separator 21 corresponding to the metal plate is provided with a predetermined planar shape, and is provided with a concavo-convex shape 23 which is formed by alternately arranging a lot of concave portions 24 and convex portions 25 in an outer edge portion 22 in its planar direction as shown in
The plate 11 with frame is manufactured by a metal mold 51 which is schematically shown in
The gate portion 54 is provided at a position facing to an outer edge thickness surface 22b of the metal separator 21. Therefore, a injecting pressure of molding material tends to act on the outer edge portion 22 of the metal separator 21, in the molding material injected into the cavity portion 53 from the gate portion 54.
Further, since the metal separator 21 is greater in its peripheral length than its thickness, a plurality of gate portions 54 are provided along a peripheral direction of the outer edge portion 22 of the metal separator 21. Reference numeral 32 in
In the case that a plurality of gate portions 54 are provided along the peripheral direction of the outer edge portion 22 of the metal separator 21 as mentioned above, a weld portion 33 is set in the resin frame 31 which is molded by the cavity portion 53, the weld portion 33 being generated by the combined flow of the frame molding material while being positioned between a plurality of gate portions 54 which are adjacent to each other. A pressure (a combined flow pressure caused by the combined flow of the frame molding materials is generated in the weld portion 33. Therefore, the combined flow pressure tends to act on the outer edge portion 22 of the metal separator 21.
In the metal mold 51 shown in
Further, gates intermediate positions are respectively arranged at positions conforming to the arrangement of the concave portions 24 in the concavo-convex shape 23 in the outer edge portion 22 of the metal separator 21 in the state of being set to the metal mold 51, the gates intermediate position being to generate the weld portion 33 in the resin frame 31, in the metal mold 51 shown in
The metal mold 51 is structured as mentioned above. Further, the plate 11 with frame shown in
As mentioned above, the gate portion 54 is provided at the position facing to the outer edge thickness surface 22b of the metal separator 21 and is arranged at the position conforming to the arrangement of the concave portion 24 in the concavo-convex shape 23 in the outer edge portion 22 of the metal separator 21, in the metal mold 51. Therefore, the metal separator 21 directly faces to the gate portion 54 in the portion having the concave portion 24 in the concavo-convex shape 23, and is deformed under the influence of the injecting pressure of the frame molding material which is injected from the gate portion 54. Since a portion having the concave portion 24 in the metal separator 21 is smaller in a protruding length protruding to an inner portion of the cavity in comparison with a portion having the convex portion 25 (L1<L2 on the assumption that L1 is a protruding length of the portion having the concave portion 24, and L2 is a protruding length of the portion having the convex portion 25), the portion having the concave portion 24 has a smaller amount of deformation even if being deformed under the influence of injecting pressure of a frame molding material. More specifically, even if the portion is bent at the same angle as that in
Further, the gates intermediate position generating the weld portion 33 in the resin frame 31 is arranged at the position conforming to the arrangement of the concave portion 24 in the concavo-convex shape 23 in the outer edge portion 22 of the metal separator 21, in the metal mold 51. Therefore, the metal separator 21 is deformed in the portion having the concave portion 24 in the concavo-convex shape 23 under the influence of the combined flow pressure. Here, since the portion having the concave portion 24 in the metal separator 21 is smaller in the protruding length protruding into the inner portion of the cavity in comparison with the portion having the convex portion 25 (L1<L2 on the assumption that L1 is the protruding length of the portion having the concave portion 24, and L2 is the protruding length of the portion having the convex portion 25), the portion having the concave portion 24 has a less amount of deformation even if it deforms under the influence of the combined flow pressure. More specifically, the leading end of the outer edge portion does not reach the surface (the upper surface in the drawing) of the resin frame 31 even if the portion having the concave portion 24 is bent at the same angle as that of
Further, the deformation of the outer edge portion 22 of the metal separator 21 in the weld portion 33, it is thought that a countermeasure to deformation suppression is implemented by enlarging the width of the resin frame 31 in the weld portion 33.
More specifically, the metal mold 51 is provided with a circumferentially partial cavity width enlargement portion 53A by enlarging a width w2 of the cavity portion 53 toward an outer peripheral side in relation to a width w1 in the other portions, at the gates intermediate position where the weld portion 33 is generated in the resin frame 31, as shown in
Further, as shown in
Further, in the case that the frame width enlargement portion 31A is provided in the weld portion 33 of the resin frame 31 as mentioned above, it is possible to make a strength of the weld portion 33 where the strength is generally lowered in comparison with the other portions equal to the other portions, and it is possible to reduce a pressure difference between front and back sides of the weld portion 33. As a result, it is possible to suppress the deformation of the outer edge portion 22 of the metal separator 21 in the weld portion 33.
The planar shape of the frame width enlargement portion 31A is formed, for example, into a trapezoidal shape or an approximately trapezoidal shape which is inclined in both ends. The width w2′ of the resin frame 31 including the frame width enlargement portion 31A has a relationship between 1.2 and 2 times the width w1′ of the other portions, for example, a relationship of 1.5 times. A length of the frame width enlargement portion 31A is set to a length of one to two sets of combination of the concave portion 24 and the convex portion 25, for example, set to about 1.5 sets.
The entire disclosures of Japanese Patent Application No. 2015-142966 filed on Jul. 17, 2015 and Japanese Patent Application No. 2016-043271 filed on Mar. 7, 2016 are expressly incorporated by reference herein.
Number | Date | Country | Kind |
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2015-142966 | Jul 2015 | JP | national |
2016-043271 | Mar 2016 | JP | national |