JP2009066642A - Electromagnetic forming device for thin sheet, and metallic thin sheet for fluid apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic forming device for a thin sheet where a groove part and a bearing surface part can be simultaneously formed for only one time at high efficiency and with high precision, and to provide a metallic thin sheet for a fluid apparatus. <P>SOLUTION: In the electromagnetic forming device for a thin sheet comprising: a forming coil; a power source means for energizing the forming coil; and a forming die 2 provided with a forming part at least including a bearing surface, where the forming coil is energized from the power source means in a state where a thin sheet is interposed between the forming coil and the forming die 2, so as to generate electromagnetic force, and the thin sheet is pressed against the forming die 2 by the electromagnetic force, and this is formed, the bottom part of the bearing surface 2a in the forming die 2 is disposed with a plurality of chevron projections 11 whose height is equal to the depth of the bearing surface 2a at equal intervals. For example, a plurality of the chevron projections 11 are arranged so as to be a honeycomb shape. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electromagnetic forming apparatus for forming a thin plate into a desired shape using electromagnetic force, and a metal thin plate for a fluid device formed by the apparatus, and particularly to prevent the material from rebounding and to be dimensioned. The present invention relates to an electromagnetic forming apparatus for efficiently obtaining a thin plate product with high accuracy and a metal thin plate for fluid equipment formed by the apparatus.

  For example, thin (thickness of about 0.1 to 0.5 mm) metal sheet products such as metal separators used in polymer electrolyte fuel cells are pressed after pressing metal sheets such as stainless steel and titanium alloys. It can be obtained by applying a highly corrosion-resistant coating or the like to the molded product. In this, one or a plurality of grooves are formed, and a fluid such as a reaction gas or generated water flows in the grooves.

  The plate heat exchanger performs heat exchange by alternately flowing a primary fluid and a secondary fluid between a plurality of metal heat exchanger plates. This heat exchange plate is made of stainless steel. A thin metal plate (thickness 0.4 to 0.8 mm) such as titanium alloy or copper can be obtained by pressing or hydraulic bulging, etc. In this, a number of groove shapes are continuously formed in a wave shape. Has been.

  However, when the groove portion of the fuel cell metal separator is formed by press working, the metal thin plate is distorted inside due to drawing or stretching, and thus the metal separator for fuel cell is warped and wavy. If warpage or undulation occurs in the fuel cell metal separator, the current collector does not contact the electrode plate with sufficient surface pressure, or the surface pressure becomes non-uniform, resulting in increased contact resistance and reduced power generation voltage. I will invite you. Further, in the operation of assembling a fuel cell main body (cell stack) by stacking a plurality of electrode structures (cells) with the separator interposed therebetween, it is necessary to assemble while correcting warpage and undulation of the fuel cell metal separator. For this reason, there are problems that the work is complicated and the work efficiency is low, and the gas sealability is lowered.

  Similarly, the heat exchange plate of the plate heat exchanger is also required to have high flatness because the periphery of the groove shape of the plate is sealed, but there is a problem that fluid leakage occurs due to distortion during processing. .

  Therefore, an electromagnetic forming method has been proposed in which a large current is instantaneously applied to a forming coil to generate a shocking electromagnetic force, and a metal thin plate or the like is processed by this electromagnetic force. Less molding can be performed at high speed. This electromagnetic forming method is applied to, for example, caulking of pipes and shafts, overhang forming of a body portion, flange processing, etc., and has been used mainly for relatively thick (about 1-2 mm plate thickness) aluminum materials.

  In Patent Document 1, as a method of forming a dish having a three-dimensional pattern, a strong pulse magnetic force (PMF) is generated by using a mold having a shape corresponding to the three-dimensional pattern, a forming coil device, and an electric discharge circuit. A pulse electromagnetic forming apparatus and method for forming a flat metal plate into a desired shape by the pulse magnetic force have been proposed.

  By the way, in the metal sheet molded product such as the fuel cell metal separator and the heat exchange plate of the plate heat exchanger, a fluid such as a reaction gas or cooling water is flowed into a groove formed in the center of the sheet. In addition, a seat surface portion for distributing a fluid called a header is formed at the entrance and exit of the fluid flowing through the groove portion.

  When a metal sheet molded product having both a groove and a seating surface is obtained by electromagnetic forming, such as a fuel cell metal separator or a heat exchanger plate of a plate heat exchanger, the material collides with the mold bottom during molding at the seating surface. As a result of this rebound phenomenon, the center part of the seating surface portion of the product remains a depression, and a product having a desired shape cannot be obtained.

  Non-Patent Documents 1 and 2 report the results of experiments conducted on electromagnetic forming using a dish-shaped (plane seat shape) mold. In these documents, there is a description that a rebound phenomenon occurs when the energy (charging voltage) is increased in a dish-shaped mold, and as a solution to this problem, the molding shape is improved by performing molding a plurality of times. Has been reported.

Non-Patent Document 1 reports that when a groove-shaped mold is used, good molding results are obtained even when the energy is increased.
JP 2001-526963 A `` Plasticity and processing '' vol.19 no.206 (1978-3) P.220 `` Plasticity and processing '' vol.18 no.194 (1977-3) P.197

  However, the method of performing molding a plurality of times has the following problems. That is, although electromagnetic forming is high-speed forming, the capacitor must be charged with a forming charge before processing, and it takes time for the charging. In addition, there is a problem in that the production efficiency is poor because the multiple molding needs to repeat charging and discharging (energization) by the number of moldings.

  In addition, in multiple molding, the molding energy for each round differs depending on the depth and area of the seat surface to be molded. Therefore, if multiple different seat surfaces exist in the same product, the size of each molding energy is large. Setting molding conditions such as the number of sheaths is extremely difficult.

  In addition, as another molding method, only the seat surface part is formed by general press working and processed together with electromagnetic forming, or the seat surface part is formed independently as a separate part, and this seat surface part is formed afterwards. Although joining methods are conceivable, each method has a problem that it is difficult to achieve satisfactory results in terms of productivity, quality, management, and the like.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and the object of the present invention is for a thin plate electromagnetic forming apparatus and a fluid device capable of forming a groove and a seating surface at the same time efficiently and with high accuracy. It is to provide a metal sheet.

  In order to achieve the above object, the invention according to claim 1 comprises a molding coil, a power supply means for energizing the molding coil, and a molding die having a molding part including at least a seating surface, and the molding coil. In a state where a thin plate is interposed between the molding die and the power source, the power supply means energizes the molding coil to generate an electromagnetic force, and the electromagnetic plate is pressed against the molding die by the electromagnetic force to mold the molding coil. The thin plate electromagnetic forming apparatus is characterized in that a plurality of chevron projections having a height equal to the seat surface depth are arranged at equal intervals on the seat surface bottom of the molding die.

  According to a second aspect of the present invention, in the first aspect of the present invention, the plurality of chevron protrusions are arranged in a honeycomb shape.

  A third aspect of the invention is characterized in that, in the first or second aspect of the invention, a plurality of grooves are formed on the slope of the chevron protrusion or the peripheral edge of the seating surface.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the angled projections adjacent to each other at the bottom of the seating surface of the molding die or between the angled projections and the peripheral edge of the seating surface. A chevron or bead-like projection having a height lower than that of the chevron is disposed between them.

  The metal thin plate for a fluid device according to claim 5 is characterized in that it has a header structure in which a seating surface shape is formed by the electromagnetic forming device according to any one of claims 1 to 4 to form a laminated structure. To do.

  The invention according to claim 6 includes a molded coil, a power supply means for energizing the molded coil, and a molding die having a molding part including at least a groove shape, and the molding coil and the molding die In an electromagnetic forming apparatus for a thin plate, an electromagnetic force is generated by energizing a forming coil from the power source means with a thin plate interposed therebetween, and the thin plate is pressed against the molding die by the electromagnetic force to form the electromagnetic force. A chevron projection or a bead-shaped projection having a height lower than the groove shape depth is arranged on the groove shape bottom of the molding die.

  A seventh aspect of the invention is characterized in that, in the sixth aspect of the invention, a plurality of grooves are formed on a slope of the groove peripheral edge of the molding die.

  The metal thin plate for a fluid device according to claim 8 is the invention according to claim 6, and has a flow path having a groove shape formed by the electromagnetic forming apparatus according to claim 6 or 7 to form a laminated structure. It is characterized by.

  According to the first aspect of the present invention, since the plurality of chevron protrusions whose height is equal to the seating surface depth are arranged at equal intervals on the seating surface bottom portion of the molding die, The thin plate material can be constrained by the top, and the shape of the molding is the same as that of the groove forming, so that the occurrence of the material rebound phenomenon is suppressed. Therefore, the groove portion and the seating surface portion are simultaneously and efficiently formed on the thin plate at once. It can be molded accurately.

  According to the invention described in claim 2, since the plurality of chevron projections are arranged in a honeycomb shape, the spacing between the chevron projections is the most uniform, that is, dense, and the material in the seating surface can be restrained most efficiently. The groove portion and the seat surface portion can be formed with high accuracy in the thin plate while suppressing the occurrence of the rebound phenomenon.

  According to the third aspect of the present invention, even when the molding force becomes strong and the material collides with the angled protrusion or the inclined surface of the peripheral surface of the seating surface, the material sequentially collides with the plurality of grooves formed on the inclined surface and is plastic. Since deformation occurs and kinetic energy is absorbed step by step as the molding proceeds, the occurrence of the material rebound phenomenon is effectively suppressed, and the seat portion is molded with high accuracy on the thin plate.

  By the way, when the arrangement interval between the chevron projections is increased to some extent, the bottom portion of the seating surface of the molding die is widened, and the material rebound phenomenon occurs at the widened bottom portion of the seating surface. For example, a chevron or bead-like projection having a height lower than that of the chevron protrusion is disposed between adjacent chevron protrusions at the bottom of the seating surface of the molding die or between the chevron protrusion and the peripheral edge of the seating surface. Before the material between the chevron protrusions collides with the bottom chevron or bead-like protrusion, the material deforms plastically. Since kinetic energy is absorbed by this, the rebound of material is suppressed and the thin plate product of a desired shape can be obtained with high precision.

  According to the fifth aspect of the present invention, since the bounce at the time of molding can be suppressed at the seat surface portion, it is possible to obtain a metal thin plate for a fluid device having a header portion with high product accuracy.

  According to the sixth aspect of the present invention, since the chevron or bead-shaped protrusion whose height is lower than the groove-shaped depth is arranged at the groove-shaped bottom part of the molding die, the wide groove part is formed on the thin plate. However, before the material in the groove in the middle of molding collides with the bottom of the groove or the bead-shaped protrusion, the material deforms plastically. As a result, kinetic energy is absorbed, so that rebound of the material is suppressed and a groove having a desired shape can be formed on the thin plate with high accuracy.

  According to the seventh aspect of the present invention, even if the molding force becomes strong and the material collides with the inclined surface of the groove peripheral portion, the material sequentially collides with the plurality of grooves formed on the inclined surface, and the kinetic energy is formed. Since it is absorbed step by step, the occurrence of the material rebound phenomenon is effectively suppressed, and the groove shape can be formed on the thin plate with high accuracy.

  According to the eighth aspect of the invention, since the rebound at the time of molding can be suppressed by the groove-shaped portion, it is possible to obtain a metal thin plate for a fluid device having a flow path with high product accuracy.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 is a cross-sectional view of the electromagnetic forming apparatus according to the present invention (cross-sectional view taken along line AA in FIG. 2), FIG. 2 is a plan view of the electromagnetic forming apparatus with a fixing member removed, and FIG. It is a fragmentary perspective view of the metal separator for fuel cells shape | molded by the electromagnetic shaping | molding apparatus.

  An electromagnetic forming apparatus 1 according to the present invention is an apparatus for forming a thin plate using electromagnetic force. For example, a groove WA and a seating surface WB are simultaneously formed in a metal separator W for a fuel cell shown in FIG. It is a device to do.

  Thus, when the fuel cell metal separator W shown in FIG. 3 is molded, as shown in FIGS. 1 and 2, an aluminum thin plate 3 as a molding material is formed on the block-shaped molding die 2, A one-turn coil 4 composed of an E-shaped metal flat plate and a rectangular flat plate-like fixing member 5 having a suitable strength and rigidity that can withstand a reaction force that the one-turn coil 4 receives from the thin plate 3 and is relatively thick are sequentially stacked. At the same time, a heat-resistant sheet 6 made of polyimide and an insulating sheet 7 are interposed between the molding die 2 and the thin plate 3 and between the thin plate 3 and the one-turn coil 4, respectively. The molding die 2, the heat-resistant sheet 6, the thin plate 3, the insulating sheet 7, the one-turn coil 4 and the fixing member 5 are sequentially laminated so that the laminated structure is not destroyed by the electromagnetic force generated in the one-turn coil 4. It is fixed by a vertical restraining means (for example, a hydraulic cylinder mechanism).

  By the way, in the central portion of the fuel cell metal separator W shown in FIG. 3 formed by the electromagnetic forming apparatus 1, there are a plurality of groove portions WA and a seat called a header which is an inlet / outlet of a fluid flowing in the groove portion WA. Surface portion WB is formed. The fuel cell metal separator W shown in FIG. 3 is used for a solid polymer fuel cell, and a plurality of electrode structures (cells) are stacked with the fuel cell main body (cell) Cell stack) is assembled.

  Thus, as shown in FIG. 1, a molding part 2A is formed at the center of the upper surface of the molding die 2, and a flat peripheral part 2B is formed around it. In the molding portion 2A, a groove portion WA and a seat surface portion WB of the fuel cell metal separator W shown in FIG. 3 are formed, and a recess portion Wa and a hole Wb are formed in the seat surface portion WB.

  Further, as a material to be molded, the thin plate 3 is configured with an aluminum material (for example, A1050) having a high conductivity (low electric resistance) as an example for the sake of simplicity. For example, when the material to be molded is stainless steel or titanium alloy having low conductivity, a material having high conductivity such as aluminum or copper is interposed between the coil 4 and the thin plate 3 as a driver, and further, the coil 4, driver, What is necessary is just to put the insulating sheet 7 between the thin plates 3 and to laminate them.

  The one-turn coil 4 is made of, for example, a chrome copper plate having a thickness of 1.0 mm, and is formed in an E shape in plan view by the two slits 4a as described above. A narrow current concentration portion 4A is formed at the center of the one-turn coil 4, and a wide return portion 4B is formed on the left and right sides of the slit 4a. Here, the length a of the current concentrating portion 4A of the one-turn coil 4 is set longer than the length of the molding die 2 and the thin plate 3, and the width b is set wider than the width of the molding portion 2A of the molding die 2. Has been. That is, as shown in FIG. 1, the current concentration portion 4 </ b> A of the one-turn coil 4 has a size that covers a part of the molding portion 2 </ b> A of the mold 2 and the surrounding peripheral portion 2 </ b> B from above.

  The fixing member 5 is made of an electrically insulating material, for example, a stone material such as marble, a glass epoxy resin, or the like.

  Furthermore, as the heat-resistant sheet 6 and the insulating sheet 7, a 0.05 mm thick polyimide sheet having high heat resistance and electrical insulation is used. In the present embodiment, the same material is used for the heat-resistant sheet 6 and the insulating sheet 7, but another engineer plastic with high heat resistance can be used for the heat-resistant sheet 6.

  As shown in FIG. 2, a capacitor 8 serving as a power supply means is connected to the current concentrating portion 4A of the one-turn coil 4 and the return portions 4B on both sides thereof, and the current concentrating portion 4A of the capacitor 8 and the one-turn coil 4 is connected. Discharge gap switch 9 is connected in series between the two. Further, a DC high voltage power supply 10 is connected in parallel to the capacitor 8. In the present embodiment, a DC high voltage power supply 10 having a rated voltage of 3000 V to 6000 V is used, and a capacitor 8 having a capacity of 200 μF is used. Is charged.

  Next, a method of forming the fuel cell metal separator W shown in FIG. 3 by the electromagnetic forming apparatus 1 having the above configuration will be described.

  As shown in FIG. 1, a thin plate 3, an insulating sheet 7, a one-turn coil 4, and a fixing member 5 are sequentially stacked on a heat-resistant sheet 6 and a molding die 2 as a material to be molded. 4 is fixed so as not to collapse due to the electromagnetic force generated in 4, for example, when the molding die 2 is fixed in the vertical direction by a hydraulic cylinder mechanism or the like and the discharge gap switch 9 is closed, the pre-charged capacitor 8 is turned into a one-turn coil. 4 is discharged in a time of about several tens of microseconds. In the one-turn coil 4, a current flows through the current concentrating portion 4A in the direction of the arrow in FIG. 2, and this current flows through the left and right return portions 4B in the opposite directions.

  Here, since the current concentrating portion 4A of the one-turn coil 4 has a thin planar shape with a thickness of 1 mm, its cross-sectional area is small, and since the coil is one-turn, the inductance is also small. For this reason, a large current shocks through the current concentrating portion 4A, and a large magnetic field is instantaneously and uniformly generated in the current concentrating portion 4A. This magnetic field causes the direction of the arrow (downward) in FIG. Electromagnetic force is generated.

  Further, the current concentrating portion 4A of the one-turn coil 4 has a thin planar shape, and the magnetic field generated therein is uniformly distributed in the region of the current concentrating portion 4A of the one-turn coil 4. Accordingly, the uniform magnetic field generated in the one-turn coil 4 and the electromagnetic force generated by the eddy current generated in the thin plate 3 are also uniform over the region of the current concentration portion 4A of the one-turn coil 4.

  Thus, when a large electromagnetic force is generated as described above, the thin plate 3 is pressed against the molding die 2 by receiving this electromagnetic force, and the portion of the thin plate 3 corresponding to the peripheral portion 2B of the molding die 2 is restrained. Thus, plastic deformation does not occur, and a portion of the thin plate 3 corresponding to the molding part 2A of the molding die 2 is formed by projecting into the molding part 2A, and has a groove part WA and a seating surface part WB as shown in FIG. A metal separator W is obtained. At this time, since the heat-resistant sheet 6 and the insulating sheet 7 are interposed between the molding die 2 and the thin plate 3 and between the thin plate 3 and the one-turn coil 4, respectively, the thin plate 3 is welded to the molding die 2. The short circuit of the current from the one-turn coil 5 to the thin plate 3 is reliably prevented by the heat-resistant sheet 6 and the insulating sheet 7 respectively.

  Thus, the electromagnetic forming apparatus 1 according to the present invention is characterized by, for example, a molding die 2 for molding the seating surface portion WB of the fuel cell metal separator W shown in FIG. An embodiment of the structure of the second molded portion 2A will be described below.

<Embodiment 1>
4 is a perspective view of a seating surface portion of the molding die according to Embodiment 1 of the present invention, FIG. 5 is a cross-sectional view taken along line BB of FIG. 4, and this embodiment is a seating surface of the molding die 2. A plurality of truncated cone-shaped projections 11 having a height h equal to the depth d of the seating surface 2a (h = d) are arranged in a honeycomb shape at equal intervals on the bottom of 2a.

  Here, the interval P between the adjacent chevron projections 11 is set within about three times (P ≦ 3h) the height h of the chevron projections 11 (depth d of the seating surface 2a of the molding die 2). The slope angle α of the protrusion 11 is set to about 45 °. Further, the smaller the area of the top of the chevron 11 is, the smaller the proportion of the chevron 11 that occupies the entire seating surface 2a. This is desirable for the function of the product. Since there is a possibility that the thin plate 3 may be broken, the area of the top of the chevron 11 is set to a size that does not cause the thin plate 3 to break.

  Further, in the molding die 2, the shape of the peripheral portion of the inclined surface of the seating surface 2 a is desired to be a straight line, but it is preferable for the effect of the present invention to be equidistant from each angled projection 11. The shape of the peripheral portion is a shape in which circular curved surfaces are connected in accordance with the shape of the chevron 11.

  Thus, according to the present embodiment, the plurality of chevron projections 11 whose height h is equal to the depth d of the seating surface 2a are arranged at equal intervals on the bottom of the seating surface 2a of the molding die 2. The thin plate 3 can be constrained by the peripheral portion of the seating surface 2a and the top of each chevron 11 and the form of molding is the same as that of groove forming, so that the occurrence of the material rebound phenomenon is suppressed. The groove part WA and the seating surface part WB shown in FIG. 3 can be efficiently and highly accurately formed at one time.

  Further, in the present embodiment, since the plurality of chevron protrusions 11 are arranged in a honeycomb shape, the distance P between the chevron protrusions 11 is the most uniform, that is, dense, and the material in the seating surface 2a can be restrained most efficiently. As a result, the occurrence of the material rebound phenomenon is effectively suppressed, and the seat surface portion WB of the thin plate 3 can be formed with high accuracy.

  In the fuel cell metal separator W shown in FIG. 3 obtained by electromagnetic forming as described above, since the occurrence of the material rebound phenomenon is suppressed, the seat surface portion WB does not have a depression that has occurred in the past, and the seat The surface portion WB constitutes a flat surface having no depression, and a plurality of truncated conical recesses Wa corresponding to the shape of the chevron 11 of the molding die 2 are formed on the flat surface. In this case, a hole Wb is formed in a part of the seat surface portion WB along the shape of the recess Wa, and the seat surface portion WB is used as a header, but the hole Wb is partially formed in the seat surface portion WB. If the concave portion Wa is left as described above, the remaining concave portion Wa functions to rectify the fluid, and an effect that an equal flow rate can be distributed to the plurality of grooves WA is obtained.

  In the present embodiment, a truncated cone-shaped projection is used as the chevron projection 11, but an arbitrary shape can be employed as the chevron projection 11, for example, a hexagonal frustum-shaped projection shown in FIG. Can also be adopted.

<Embodiment 2>
Next, a second embodiment of the present invention will be described with reference to FIGS.

  FIG. 7 is a perspective view of a seating surface portion of a mold according to Embodiment 2 of the present invention, and FIG. 8 is a cross-sectional view taken along the line CC in FIG. Similarly, a plurality of truncated cone-shaped protrusions 11 whose height is equal to the depth of the seating surface 2a are arranged in a honeycomb shape at equal intervals on the bottom of the seating surface 2a of the molding die 2. A bead-shaped projection 12 having a height lower than that of the chevron projection 11 is disposed between the adjacent chevron projections 11 at the bottom of the seat surface 2a of the mold 2 and between the chevron projection 11 and the inclined peripheral portion of the seat surface 2a. ing.

  Thus, according to the present embodiment, the groove part WA and the seating surface part WB shown in FIG. 3 can be simultaneously and efficiently formed in the thin plate 3 at the same time in the same manner as in the first embodiment. However, when the arrangement interval between the chevron projections 11 is increased to some extent (P> 3h), the bottom portion of the seating surface 2a of the molding die 2 is also widened, and the material rebound phenomenon occurs at the widened bottom surface of the seating surface 2a. there is a possibility.

  However, in the present embodiment, the height of the projection 2 is higher than that of the chevron 11 between the adjacent chevron 11 on the bottom of the seating surface 2a of the molding die 2 and between the chevron 11 and the inclined peripheral edge of the seat 2a. Since the bead-shaped projections 12 having a low height are arranged, the material between the mountain-shaped projections 11 in the middle of molding collides with the bead-shaped projections 12 before the bottom of the seating surface 2a. The impacted material is plastically deformed due to the protrusion shape, so that the kinetic energy is absorbed, thereby suppressing the rebound of the material, so that a thin plate product such as a fuel cell metal separator W as shown in FIG. It can be obtained with high accuracy.

  In the present embodiment, it is higher than the chevron 11 between the chevron 11 adjacent to each other at the bottom of the seating surface 2a of the molding die 2 and between the chevron 11 and the inclined peripheral edge of the seat 2a. Although one bead-shaped protrusion 12 having a small height is arranged, a plurality of bead-shaped protrusions 12 may be provided. Further, instead of the bead-shaped projections 12, chevron projections lower in height than the chevron projections 11 may be continuously arranged.

<Embodiment 3>
Next, a third embodiment of the present invention will be described with reference to FIGS.

  9 is a perspective view of a seating surface portion of a mold according to Embodiment 3 of the present invention, and FIG. 10 is a cross-sectional view taken along the line DD of FIG.

  In the present embodiment, similar to the second embodiment, a plurality of truncated cone-shaped protrusions 11 whose height is equal to the depth of the seating surface 2a are equally spaced on the bottom of the seating surface 2a of the molding die 2. In the form of a honeycomb, and higher than the chevron 11 between the chevron 11 adjacent to each other at the bottom of the seating surface 2a of the molding die 2 and between the chevron 11 and the inclined peripheral edge of the seating surface 2a. Although the bead-shaped projection 12 having a small height is arranged, a plurality of grooves 13 are formed on the slope of the chevron 12 and the slope of the peripheral edge of the seating surface 2 a of the molding die 2.

  Thus, according to the present embodiment, the following effects can be further obtained in addition to the effects obtained by the second embodiment.

  That is, even if the molding force is increased and the material collides with the angled protrusion 11 and the slope of the peripheral surface of the seating surface 2a of the molding die 2, the material sequentially collides with the plurality of grooves 13 formed on the slope to cause plasticity. Since the deformation and the kinetic energy are absorbed step by step as the molding progresses, the occurrence of the material rebound phenomenon is effectively suppressed, and the seat surface portion WB as shown in FIG. 3 is molded with high accuracy.

  As described above, the heat exchange plate for the heat exchanger obtained by electromagnetically forming the seating surface 2a portion shown in FIG. 9 with the molding die 2 has a small groove formed on the surface, so that the surface area increases. The effect that the heat exchange efficiency is increased is obtained.

  In the present embodiment, a height higher than the angle protrusion 11 between the adjacent angle protrusions 11 at the bottom of the seating surface 2a of the molding die 11 and between the angle protrusion 11 and the inclined peripheral edge of the seating surface 2a. FIG. 11 shows an example in which two bead-shaped projections 12 and a continuous mountain-shaped projection 14 are provided side by side.

<Embodiment 4>
Next, a fourth embodiment of the present invention will be described with reference to FIG.

  FIG. 12 is a perspective view of the seating surface portion of the molding die according to the fourth embodiment of the present invention. In this embodiment, the bottom of the seating surface 2a of the molding die 2 is the same as in the second embodiment. A plurality of truncated cone-shaped projections 11 whose height is equal to the depth of the seating surface 2a are arranged in a honeycomb shape at equal intervals, and the slope of the chevron projection 11 and the molding die 2 are the same as in the third embodiment. A plurality of grooves 13 are formed on the slope of the peripheral edge of the seating surface 2a.

  Therefore, according to the present embodiment, the same effect as in the third embodiment can be obtained in addition to the effect obtained in the first embodiment. That is, even if the molding force becomes strong and the material collides with the slope of the chevron 11 and the peripheral surface of the seating surface 2a of the molding die 2, the material collides sequentially with the plurality of grooves 13 formed on the slope and the impact. Since energy is absorbed step by step with the progress of molding, the occurrence of the material rebound phenomenon is effectively suppressed, and the seat portion WB as shown in FIG. 3 is molded with high accuracy.

<Embodiment 5>
Next, a fifth embodiment of the present invention will be described with reference to FIGS.

  13 is a perspective view of a groove portion of a molding die according to Embodiment 5 of the present invention, FIG. 14 is a cross-sectional view taken along the line EE of FIG. 13, and in this embodiment, the groove portion WA is formed in the thin plate 3. Therefore, a feature is that a bead-shaped projection 12 lower than the depth of the groove 2b is disposed on the groove bottom 2c of the groove 2b of the molding die 2 and a plurality of grooves 13 are formed on the inclined surface of the peripheral edge of the groove 2b.

  By the way, when the groove 2b of the molding die 2 is wide (when the groove width is larger than three times the groove depth), a material rebound phenomenon may occur at the groove bottom 2c.

  However, in the present embodiment, since the bead-shaped projections 12 lower than the depth of the groove 2b are arranged on the groove bottom portion 2c of the molding die 2, the material in the groove 2b in the middle of the molding is a bead-shaped projection before the groove bottom portion 2c. 12 hits. The impacted material is plastically deformed by the bead-shaped protrusion 12 and the kinetic energy is absorbed, so that the material bounce is suppressed and the groove WA having a desired shape can be formed in the thin plate 3 with high accuracy.

  In the present embodiment, the bead-shaped protrusion 12 lower than the depth of the groove 2b is disposed on the groove bottom 2c of the molding die 2. However, instead of the bead-shaped protrusion 12, continuous chevron protrusions lower than the depth of the groove 2b are provided. It may be arranged.

  In addition, since the heat exchange plate of the plate type heat exchanger formed in the present embodiment has an increased surface area, the effect of improving the heat exchange efficiency as in the third embodiment can be obtained.

  The use of the thin plate formed by the electromagnetic forming apparatus according to the present invention is not limited to the metal separator for a fuel cell or the heat exchange plate for a plate heat exchanger, but has a seat surface shape or a groove shape. It is possible to spread a wide range of metal thin plates for fluid equipment used by laminating a plurality of thin metal plates and flowing a fluid between the thin plates.

It is sectional drawing (the AA sectional view taken on the line of FIG. 2) of the electromagnetic forming apparatus which concerns on this invention. It is a top view in the state where the fixing member of the electromagnetic forming device concerning the present invention was removed. It is a fragmentary perspective view of the metal separator for fuel cells shape | molded by the electromagnetic forming apparatus which concerns on this invention. It is a perspective view of the seat surface part of the shaping | molding die concerning Embodiment 1 of this invention. It is the BB sectional view taken on the line of FIG. It is a perspective view of the seat surface part of the shaping | molding die which concerns on the modification of Embodiment 1 of this invention. It is a perspective view of the seating surface part of the shaping | molding die concerning Embodiment 2 of this invention. It is CC sectional view taken on the line of FIG. It is a perspective view of the seat surface part of the shaping | molding die concerning Embodiment 3 of this invention. FIG. 10 is a sectional view taken along line D-D in FIG. 9. It is a perspective view of the seat surface part of the shaping | molding die which concerns on the modification of Embodiment 3 of this invention. It is a perspective view of the seat surface part of the shaping | molding die concerning Embodiment 4 of this invention. It is a perspective view of the groove part of the shaping | molding die which concerns on Embodiment 5 of this invention. It is the EE sectional view taken on the line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electromagnetic forming apparatus 2 Molding die 2A Molding part 2B Peripheral part of molding die 2a Seating surface of molding die 2b Groove of molding die 2c Groove bottom part of molding die 3 Thin plate 4 One-turn coil (molding coil )
4A One-turn coil current concentration part 4B One-turn coil return part 4a One-turn coil slit 5 Fixing member 6 Heat-resistant sheet 7 Insulation sheet 8 Capacitor 9 Discharge gap switch 10 DC high-voltage power supply (power supply means)
DESCRIPTION OF SYMBOLS 11 Angle projection 12 Bead-shaped projection 13 Groove 14 Angle projection W Metal separator for fuel cells WA Groove portion of metal separator for fuel cell WB Seat surface portion of metal separator for fuel cell Wa Concavity of seat surface portion Wb Hole of seat surface portion d Mold mold Bearing surface depth h Height of chevron protrusion P Spacing of chevron protrusion α Slope angle of chevron protrusion

Claims (8)

A state in which a molding coil, power supply means for energizing the molding coil, and a molding die having a molding part including at least a seating surface are provided, and a thin plate is interposed between the molding coil and the molding die In the electromagnetic forming apparatus for a thin plate, an electromagnetic force is generated by energizing the molding coil from the power source means, and the thin plate is pressed against the molding die by the electromagnetic force to form the electromagnetic force.
A thin plate electromagnetic forming apparatus, wherein a plurality of chevron projections having a height equal to a seating surface depth are arranged at equal intervals on a seating surface bottom portion of the molding die.   The thin plate electromagnetic forming apparatus according to claim 1, wherein the plurality of chevron protrusions are arranged in a honeycomb shape.   The thin plate electromagnetic forming apparatus according to claim 1, wherein a plurality of grooves are formed on the slope of the chevron protrusion or the peripheral edge of the seat surface.   A chevron projection or a bead-like projection having a height lower than that of the chevron projection is disposed between the chevron projections adjacent to each other at the bottom of the seating surface of the molding die or between the chevron projection and the periphery of the seating surface. The electromagnetic forming apparatus for a thin plate according to any one of claims 1 to 3.   A metal thin plate for a fluid device, comprising a header portion having a seat shape formed by the electromagnetic forming apparatus according to any one of claims 1 to 4 to form a laminated structure. A state in which a molding coil, power supply means for energizing the molding coil, and a molding die having a molding part including at least a groove shape are provided, and a thin plate is interposed between the molding coil and the molding die In the electromagnetic forming apparatus for a thin plate, an electromagnetic force is generated by energizing the molding coil from the power source means, and the thin plate is pressed against the molding die by the electromagnetic force to form the electromagnetic force.
An electromagnetic forming apparatus for a thin plate, wherein a chevron projection or a bead-shaped projection having a height lower than the groove shape depth is arranged at the groove shape bottom of the molding die.   The thin plate electromagnetic forming apparatus according to claim 6, wherein a plurality of grooves are formed on a slope of the peripheral edge of the groove of the molding die.   A metal thin plate for a fluid device having a flow path having a groove shape formed by the electromagnetic forming apparatus according to claim 6 or 7 to form a laminated structure.

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