JP3981695B2 - Fuel cell separator molding die, fuel cell separator manufacturing method, and fuel cell separator - Google Patents

Description

  The present invention generally relates to a method for manufacturing a fuel cell separator, and more specifically, a molding die for obtaining a fuel cell separator by compression molding using a material mainly composed of carbonaceous powder having poor fluidity, and manufacturing The present invention relates to a method and a fuel cell separator.

  Fuel cell power generation system is widely considered as a clean and highly efficient new technology to solve the increase in carbon dioxide emissions accompanying the recent increase in energy consumption and the depletion of fossil resources such as oil. Is promoted.

  In particular, a polymer electrolyte fuel cell (PEFC) system that uses an ion exchange membrane as an electrolyte can be easily operated and stopped because its operating temperature is relatively low, at 80 ° C or less. is there. In addition, because of its high energy efficiency, introduction into home cogeneration, automobiles, portable devices, etc. is expected.

  The basic cell used in polymer electrolyte fuel cells is a membrane / electrode assembly (MEA) consisting of an electrolyte membrane consisting of an ion exchange membrane sandwiched between an anode (fuel electrode) and a cathode (air electrode). The MEA is sandwiched between two separators from both sides.

  On the separator surface, there are formed flow channel grooves for supplying a fuel gas such as hydrogen to the anode (fuel electrode) of the MEA and an oxidizing gas such as oxygen and air to the cathode (air electrode). Moreover, the refrigerant | coolant flow path for flowing a refrigerant | coolant may be formed. Further, the separator functions as a shielding plate for separating the fuel gas and the oxidizing gas.

  Then, depending on the electrical output required for the fuel cell system, several tens to several hundreds of such basic cells are stacked in series to form a stack.

Typical characteristics required for separators having the above functions are that the electrical resistance value is 20 mΩ · cm or less, based on the US Department of Energy (DOE) target value, and gas For the permeability to be 2 × 10 ⁻⁶ cc / cm ² · sec · atm or less, to be thin and light, and to spread to the market, a significant reduction in manufacturing cost is indispensable.

  A separator with such properties and costs is initially mixed and molded with a carbonaceous material and a thermosetting resin binder, and after heat curing, it is treated for a long time at a high temperature of 1000 ° C or higher in a non-oxidizing atmosphere. Was calcined by firing.

  Since the molded product obtained by this method is plate-shaped, cutting of gas flow channel grooves, gas introduction holes, stack holes, and the like is required, resulting in a problem that the cost is very high.

In contrast, a method in which a resin-based binder is mixed with a graphite powder material with excellent electrical conductivity, and compression molding using a mold capable of forming a channel groove shape and hole shape in advance satisfies various properties required for the separator. In addition, since it does not require cutting, it has attracted attention as a manufacturing method that can realize low cost.
JP 2004-235137 A JP 2004-22207 A JP 2004-235069 A

  However, in order to obtain high conductivity, the graphite content needs to be 75 wt% or more, so that the fluidity of the material is significantly reduced. As a result, in the case of compression molding to form various shapes necessary for the separator, there are the following problems.

  The separator has a gas flow channel groove portion and a surrounding surrounding portion on the surface, but the density of the gas flow channel groove portion and the surrounding portion is not uniform. That is, the gas channel groove portion has a high material compression ratio, and the surrounding portion has a low material compression ratio. Therefore, since the density of the graphite in the surrounding portion is lower than that in the gas flow channel groove portion, the conductivity is lowered and the gas permeability is increased.

  FIG. 1 shows an example of a general separator, and FIG. 2 shows a cross-sectional view thereof. 1 and 2 show an embodiment of a fuel cell separator according to the present invention. Since the shape of the separator is a general shape, the shape shown in the drawing is generally used here. The separator will be described.

In order to improve the high conductivity required for the separator, it is important to make it as close as possible to a density of 100% graphite of 2.1 g / cm ³ . If the bulk density of the powder material, which is a blending ratio of graphite 80 wt% and phenol resin 20 wt%, is 0.65 g / cm ³ and the product target density is 1.95 g / cm ³ , the compression ratio at the time of compression molding is 3. . The powder material to be filled in the mold is 6 mm because the compression ratio is 3 if the product thickness is 2 mm.

At this time, when the surrounding area is set to a compression ratio 3 as shown in FIG. 18, the area for forming the gas flow path groove is a press according to the compression ratio 3 from the cross-sectional area 86.4 mm ² at the time of filling. When the stroke is compressed by 4 mm, the cross-sectional area is 22.2 mm ² , and the compression ratio of the gas channel groove when the cross-sectional area is used as a reference is 3.9, which is an excess compression ratio of 30% with respect to the surrounding area. . This phenomenon becomes more prominent as the cross-sectional area of the gas channel groove is larger and the product thickness is thinner.

  The difference in the compression ratio due to the product cross-sectional shape is fundamentally due to the fact that there is almost no material flow in the transverse direction to the compression direction due to the poor flowability of the powder material.

  On the other hand, there are the following problems also in mold release after product shape formation by compression molding.

  In order to increase the density of graphite, the pressing pressure is formed at about 30 MPa or more. Therefore, a high compressive stress remains in the molded product in the mold, and the mold expands because the stress is released after being released from the mold. This phenomenon is called springback, and causes defects such as the occurrence of warpage and deformation of the product, and cracks and chips due to an increase in the release resistance of the gas flow channel groove. This is particularly noticeable when the product shape is thin and the gas channel groove is deep.

  In this way, while maintaining the high electrical conductivity required for separators, it is becoming increasingly difficult to form due to thinner product shapes, narrow pitches in gas flow channel grooves, and increased groove depth. There is a present situation, and construction of manufacturing technology by further compression molding is desired.

  The present invention has been made to solve the above-mentioned problems, and adopts an appropriate mold and molding process in a separator manufacturing method by compression molding using a powder material having high graphite content and poor fluidity. As a result, the density balance between the gas flow channel groove area and the surrounding area on the separator surface is made uniform, and even when taking out the product from the mold, there is little deformation, warping or cracking, and the fuel cell has high quality and high productivity. An object is to provide a molding die for a separator, a method for producing a fuel cell separator, and a fuel cell separator.

Method for manufacturing a fuel cell separator according to claim 1 of the present invention, by compression molding of powdery material using a die, to produce a fuel cell separator having at least one surface in the flow path grooves and surrounding portion preparation A method, wherein one mold and the other mold located on the one side and divided into an inner mold corresponding to the flow channel groove and an outer mold corresponding to the surrounding part, After the compression molding by the above, the outer mold is protruded with respect to the inner mold so that the flow channel groove part is released prior to the surrounding part when the mold is opened for taking out the molded product. It is what.

According to a second aspect of the present invention, there is provided a fuel cell separator manufacturing method for manufacturing a fuel cell separator having a flow channel groove portion and a surrounding portion on at least one side by compression molding a powdery material using a mold. A method, wherein one mold and the other mold located on the one side and divided into an inner mold corresponding to the flow channel groove and an outer mold corresponding to the surrounding part, After the compression molding with the frame that forms the outer periphery of the cavity formed between the molds, the flow channel groove part is released prior to the surrounding part when the mold is opened for taking out the molded product. The outer mold is protruded with respect to the inner mold, the flow channel groove part is released, and the surrounding part is not released, and the frame body is moved to move the outer periphery of the molded product Characterized by being released from the frame A.

According to a third aspect of the present invention, there is provided a method for producing a fuel cell separator according to the first or second aspect , wherein the flow channel groove portion is formed before the surrounding portion when the mold is opened. When the outer mold is protruded from the inner mold so as to release, the compressed air is separated from the dividing surface of the inner mold and the outer mold so that the flow channel groove portion is easily released. Is ejected.

According to a fourth aspect of the present invention, there is provided a method of manufacturing a fuel cell separator, wherein a fuel cell separator having a channel groove portion and an surrounding portion on each of the front and back surfaces is produced by compression molding a powdery material using a mold. An upper mold and a lower mold divided into an upper inner mold and a lower inner mold corresponding to the flow channel groove, and an upper outer mold and a lower outer mold corresponding to the surrounding portion, which are manufacturing methods. After compression molding with a mold, when opening the mold for taking out a molded product, the upper inner mold and the lower inner mold are arranged so that the flow channel groove part is released prior to the surrounding parts on the front and back surfaces. On the other hand, the upper outer mold and the lower outer mold are protruded.

A fuel cell separator manufacturing method according to claim 5 of the present invention is the fuel cell separator manufacturing method according to claim 4 , wherein the upper mold and the lower mold, and a cavity formed between the two molds are provided. The upper outer mold and the lower outer mold protrude with respect to the upper inner mold and the lower inner mold when the mold is opened for taking out a molded product after compression molding with the frame that bears the outer periphery of the mold. And moving the frame body to release the outer periphery of the molded product from the frame body in a state where the flow channel grooves on the front and back surfaces are released and the surrounding parts on the front and back surfaces are not released. It is characterized by.

A fuel cell separator manufacturing method according to claim 6 of the present invention is the fuel cell separator manufacturing method according to claim 4 or 5 , wherein the upper inner mold and the lower inner mold are formed when the mold is opened. On the other hand, when the upper outer mold and the lower outer mold are protruded, the upper inner mold, the lower inner mold, and the upper outer mold are formed so that the flow path grooves on the front and back surfaces can be easily separated. Compressed air is ejected from a dividing surface between the mold and the lower outer mold.

  The present invention is also a manufacturing method for manufacturing a fuel cell separator having a flow channel groove portion and an enclosure portion on at least one side by compression molding a powdery material using a mold, In order to take out a molded product after compression molding by the other mold that is located on the one side and is divided into an inner mold corresponding to the flow channel groove and an outer mold corresponding to the surrounding part. When the mold is opened, the outer mold protrudes from the inner mold so that the flow path groove part is released prior to the surrounding part, so that a springback occurs when the separator is taken out. The flow path groove region can be released in advance, so that a separator having no shape defect can be manufactured.

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

  1A and 1B show a fuel cell separator according to an embodiment of the present invention. FIG. 1A is a front view and FIG. 1B is a rear view. FIG. 2 is a sectional view taken along line II-II in FIG. And (b) is an enlarged view of a portion A.

  This fuel cell separator 1 is a separator applied to a polymer electrolyte fuel cell system, and has a flow channel groove portion 2 and a surrounding portion 4 surrounding the flow channel groove portion 2 on both surfaces (at least one surface). ing.

  Although the dimensions of the separator 1 vary depending on the power generation capacity of the fuel cell system, the outer shape is 50 to 400 mm, for example, 150 mm in length × 100 mm in width, and the thickness is 0.5 to 5 mm, for example, 2.0 mm.

  In the flow channel groove portion 2 of the separator 1, a groove (flow channel groove) 3 serving as a flow path for fuel gas, oxidizing gas, or cooling water is formed. The depth of the flow channel 3 is generally about ½ or less of the plate thickness of the separator 1, for example, 0.5 mm. The groove width of the channel groove 3 is 0.5 to 5 mm, for example 1 mm. The pitch between the adjacent channel grooves 3 is, for example, 2 mm. The channel groove 3 is formed in a fine arrangement in a predetermined region surrounded by the surrounding portion 4 on the surface of the separator 1 to constitute the channel groove portion 2.

  Such a channel groove 3 is connected to a manifold 5 formed in the surrounding portion 4 of the separator 1, and fuel gas, oxidizing gas or cooling water is introduced into and discharged from the channel groove 3 through the manifold 5. It is like that. In FIG. 1, only two systems of the flow channel 3 and the manifold 5 are shown, and the third flow channel and the third manifold are not shown.

  Further, although a groove is also formed in the surrounding portion 4, this groove is a groove for enclosing an appropriate sealing material, and is not a groove serving as a fluid flow path, that is, a flow path groove 3. In this specification, such a groove is defined as the surrounding portion 4.

  The molding material used for the fuel cell separator 1 according to the present invention is a mixture of carbonaceous powder as a main component and a resin-based material as a binder.

  Since the separator 1 requires high conductivity, it is desirable that the carbonaceous material has a highly crystalline graphite structure, and artificial graphite, natural graphite, swollen graphite, and the like are suitable, and these are used at an appropriate ratio. May be mixed. The average particle diameter of the graphite powder is from φ5 to 100 μm, more preferably from φ10 to 60 μm, from the viewpoint of conductivity and material fluidity. The ash content in the graphite powder is preferably 0.5% or less because it inhibits the electrochemical reaction of the catalyst adjacent to the separator 1 and lowers the durability.

  On the other hand, the resin material used as the binder of the carbonaceous powder may be either thermoplastic or thermosetting. Preferably, a thermosetting resin that forms a three-dimensional molecular structure is used in terms of mechanical strength and durability. As the thermosetting resin, for example, phenol, epoxy, diallyl phthalate, unsaturated polyester, and the like can be used. From the viewpoint of productivity and durability, a phenol resin is preferable.

  The blending ratio of the above graphite powder and the resin binder is 75 to 95 wt% graphite, 25 to 5 wt% resin binder, more preferably graphite from the balance of high conductivity, high non-gas permeability and mechanical strength. A molding material having a blending ratio of 82 to 93 wt% and a resin binder of 18 to 7 wt% is used.

  Using the above mixed material, the fuel cell separator 1 according to the present invention can be molded by a molding die and a molding process (manufacturing method) described below.

  FIG. 3 is a longitudinal sectional view showing a first embodiment of a molding die used in the method of manufacturing the fuel cell separator 1 according to the present invention. For the sake of explanation, FIG. is there. Further, the manifold 5 formed in the surrounding portion 4 and the core that is a mold for forming the through hole for stacking the separator 1 are omitted.

  The molding die 10 includes a lower die (lower punch) 21 provided on the fixed side block 20, an upper die (upper punch) 41 provided on the moving side block 40, and upper and lower die 41, 21. It has a frame (die) 30 that is a mold that bears the outer periphery of the cavity 50 to be formed. A frame (die) 30 is also provided on the stationary block 20, and an upper die (upper punch) 41 is operated together with the moving block 40 by ram pressure.

  The lower mold (lower punch) 21 includes a lower inner mold (lower inner punch) 22 that is a mold for forming the shape of the flow path groove portion 2 region on the lower surface of the separator 1 and the shape of the surrounding portion 4 region on the lower surface of the separator 1. It is divided into a lower outer mold (lower outer punch) 25 which is a mold for forming the.

  The lower punch 21 has an operating member (actuator) 24 that moves the lower inner punch 22 forward and backward with respect to the lower outer punch 25 so that the lower inner punch 22 can protrude until it contacts the stopper block 23, and the lower outer punch 22 And an actuating member (actuator) 27 that moves forward and backward so that it can protrude until it abuts against the stopper block 26.

  The actuating force of the actuator 24 that causes the lower inner punch 22 to protrude relative to the lower outer punch 25 is set to such a level that the protrusion of the lower inner punch 22 is substantially eliminated at the end of the compression process due to the ram pressure. It is what is done.

  Further, when the lower punch 21 is opened, when the lower outer punch 25 protrudes from the lower inner punch 22, the lower inner punch 22 and the lower outer punch 21 are arranged so that the channel groove 2 on the lower surface of the separator 1 can be easily released. A lower punch air blow line 28 for jetting compressed air from a split surface with the punch 25 is provided.

  The upper mold (upper punch) 41 is an upper inner mold (upper inner punch) 42 which is a mold for forming the shape of the flow channel groove 2 region on the upper surface of the separator 1 and the shape of the surrounding portion 4 region on the upper surface of the separator 1. Is divided into an upper outer mold (upper outer punch) 45 which is a mold for forming the.

  Further, the upper punch 41 includes an operating member (actuator) 47 that moves the upper outer punch 45 forward and backward with respect to the upper inner punch 42 so that the upper outer punch 45 can protrude until it comes into contact with the stopper block 46.

  The stroke by which the actuator 47 projects the upper outer punch 45 with respect to the upper inner punch 42 and the stroke by which the actuator 27 projects the lower outer punch 25 with respect to the lower inner punch 22 It is set to be slightly larger than the same dimension as the depth of the flow channel groove 2.

  Further, when the upper punch 41 projects the upper outer punch 45 with respect to the upper inner punch 42 when the mold is opened, the upper inner punch 42 and the upper outer punch 42 are arranged so that the flow channel groove 2 on the upper surface of the separator 1 is easily released. An upper punch air blow line 48 for ejecting compressed air from a split surface with the punch 45 is provided.

  The frame body (die) 30 is provided with an operating member (actuator) 32 that moves forward and backward so that the upper surface of the frame body (die) is lower than the upper surface of the lower punch 21 until it comes into contact with the stopper block 31.

  The molding die 10 has a die 30, a lower inner punch 22, a lower outer punch 25, an upper inner punch 42, and an upper outer punch 45 by a function of a pressing device (not shown) and a die setting function for holding the die. Each mold is operably held in the compression molding direction. And as shown by the arrow P in FIG. 3, it is compression-molded by the uniaxial molding from a perpendicular direction with respect to the plane part which has the largest area of the separator 1. FIG.

  Note that the mold configuration shown in FIG. 3 is an example, and the shape of the separator 1 can correspond to any mold division position and any number of mold configurations.

  Since the molding die 10 according to the present invention has a structure in which the punch is divided into the flow channel groove 2 region and the surrounding portion 4 region of the separator 1 as described above, the following molding process is possible. It is.

  In compression molding using a powder material, the material filling amount in the cavity 50 is determined by using the ratio between the target density of the compression molded product and the bulk density of the material as the compression ratio. In particular, in the case of a material having poor fluidity, the variation in the partial compression ratio of the molded product becomes the variation in density as it is, and the quality is greatly deteriorated. The filling method in the powder material compression press molding method generally eliminates excessively charged material with reference to the upper surface of the die and suppresses variation in the filling amount.

  FIG. 4 is a longitudinal sectional view of a main part showing a state where the cavity 50 of the molding die 10 is filled with a powder material.

  FIG. 5 shows a longitudinal sectional view of the separator 1 which is a compression molded product. 4 and 5 are the same cross-sectional positions.

In a manufacturing process using a molding die 10 according to the present invention, when it is assumed that the 3 ratio, i.e. the compression ratio of the bulk density of the target density and powder material, the cross-sectional area S _out of the surrounding part 4 area of the separator 1, the product since thickness is Tmm, by providing a space having a sectional area of 3 × S _out by allowing the die 30 is 3 × Tmm rises from the lower punch 21 top surface, proper material is filled.

  At this time, since the upper surface of the lower outer punch 25 is flat, an ideal material can be filled.

On the other hand, the cross-sectional area S _in of the flow channel groove 2 region of the separator 1 corresponds to the formation of the cross-sectional area of the mold convex portion for forming the flow channel 3 when the die 30 is raised by 3 × T mm. The material becomes surplus, and the material filled in the flow channel groove 2 region exceeds 3 × S _in .

Therefore, in the manufacturing process using the molding die 10 according to the present invention, the lower inner punch 22 that forms the channel groove 3 is raised by a predetermined h dimension in order to prevent the excessive filling of the material. By reducing the space to be filled by the dimension h, it is possible to adjust the cross-sectional area to 3 × S _in .

Moreover, since the dimension h is arbitrarily adjustable with respect to the density of S _out portion is a surrounding part 4, it is possible to relatively control the density of S _in part a flow path groove 2. Both densities can be made uniform, and if necessary, the density of the channel grooves 2 can be increased or decreased with respect to the density of the surrounding parts 4.

  6 to 9 show the process of compression molding in the method of manufacturing a fuel cell separator using the molding die 10 according to the present invention, FIG. 6 shows a state before filling adjustment, and FIG. 7 shows the state just before compression after filling adjustment. 8 is a longitudinal sectional view showing a state in the middle of the compression process, and FIG. 9 is a state in which the compression is completed.

  In order to reduce the density variation of the separator 1 as a whole, during the compression process, the compression speed of the flow path groove portion 2 region with a small amount of material filling and the compression speed of the surrounding portion 4 region are equalized, that is, compression is completed from the start of compression. By ending the processes up to almost simultaneously, it is possible to eliminate quality variations in both areas 2 and 4.

  Specifically, the lower inner punch 22 is floated with a holding force smaller than the compression force on the upper punch 41 side by the driving force of the actuator 24 such as air pressure, hydraulic pressure, spring, electric motor, etc. It is preferable to descend according to the compression force, or at a slightly slower speed than the upper punch 41 side. As a result, the compression speed can be delayed even in a region where the filling amount is small, that is, a region where the compression stroke is short.

  FIG. 8 shows an intermediate state where the compression ratio is 2 and the powder material is compressed. Although the lower inner punch 22 is lowered, it has not reached the compression completion position and is in an intermediate state where the target density has not been reached.

  FIG. 9 shows the compression completion state. The lower inner punch 22 is in the lower limit position by a press compression force larger than the holding and raising force by the actuator 24, and the separator 1 is formed in a state flush with the lower outer punch 25 or at a predetermined position.

  10 to 13 show a process of taking out a product after molding in the method of manufacturing a fuel cell separator using the molding die 10 according to the present invention, FIG. 10 is a state immediately before taking out, and FIG. 11 is a drawing of a channel groove. FIG. 12 is a longitudinal sectional view showing the state, FIG. 12 is a state where the die is lowered, and FIG. 13 is a state where the mold opening is completed.

  FIG. 10 shows a state immediately before the separator is taken out. At this time, a force is applied to the lower outer punch 25 and the upper outer punch 45 in the direction in which the separator 1 is protruded by the driving force of actuators 27 and 47 such as pneumatic pressure, hydraulic pressure, a spring, and an electric motor.

The protruding force is required to be smaller than the force by which the upper ram (not shown) of the pressing device presses the separator 1. When the depth of the upper inner punch 42 passage grooves 3 formed in the d _1, the stroke of the upper outer punch 45 is set to at least the same dimensions as d _1. Similarly, to set the depth of flow grooves 3 formed under the inner punch 22 When d _2, or more strokes to as d ₂ same size of lower outer punch 25.

FIG. 11 shows a state in which the mold of the channel groove portion 2 having poor releasability is extracted from the separator 1. When the upper ram rises with the upper outer punch 45 and the lower outer punch 25 projecting toward the separator 1, the upper inner punch 42 uses the upper outer punch 45 as a supporting point, and similarly the lower inner punch 22 Using the lower outer punch 25 as a support point, a force for releasing from the separator 1 works. When the upper ram rises the sum (d ₁ + d ₂ ) of the step heights 3 on both the upper and lower surfaces of the separator 1, the flow channel grooves 3 on both the upper and lower surfaces of the separator 1 are released from the mold.

  At the start of this process, that is, immediately after the start of mold release, the flow path groove portion 2 of the separator 1 is released in a sealed state. Therefore, almost no introduction of outside air from the separator 1 and the mold surface and the mold dividing line can be expected. First, the pressure is reduced. Therefore, by releasing compressed air from the divided surfaces of the inner punches 22 and 42 and the outer punches 25 and 45, smooth release is possible.

  FIG. 12 shows a state where the die 30 forming the outer peripheral shape of the separator 1 is lowered. A large compressive stress is generated inside the separator 1 immediately after being formed by compression molding. When the separator 1 is taken out, the internal stress is released at the same time as the mold is released, a spring back is generated, and the separator 1 expands. The amount of springback varies depending on the material, molding temperature, compressive force, etc., but is about 0.2 to 0.8%, and an expansion amount of 1 mm or more is obtained with a separator having a length of 150 mm × width of 100 mm.

  As shown in FIG. 12, the internal stress is released in the plane direction (lateral direction in the figure) of the separator 1 by pulling out the die 30 while holding the separator 1 with the upper outer punch 45 and the lower outer punch 25. . If all the upper punches 41 are raised before the die 30 is extracted, the internal stress that cannot be released to the outer peripheral side loses the escape field, and the central portion of the separator 1 is deformed into a convex shape.

  FIG. 13 shows a state where the upper punch 41 is completely removed from the separator 1 and can be easily removed. As a method for reliably releasing the upper punch 41 and the separator 1, the air blow on the upper punch 41 side may be operated slightly longer than the lower punch 21 side.

  Hereinafter, a molding process of a fuel cell separator that is compression-molded by the manufacturing method according to the present invention using the molding die according to the present invention will be specifically described. However, the present invention is not limited to these examples.

(1) The shape of the separator 1 is 150 mm in length, 100 mm in width, 2 mm in thickness (or 2.5 mm), the gas channel groove 3 is 1 mm in width, 0.5 mm in depth, and the pitch is 2 mm. Placed in the center of

(2) The powder material used was a mixture of 0.15% ash, 80 wt% spherical natural graphite (or similar artificial graphite) having an average particle diameter of 30 μm, and the resin binder was a 20 wt% resol type phenol. The bulk density is 0.65 g / cm ³ .

(3) An upper ram descending type 150-ton hydraulic press was used as the compression molding apparatus. The upper inner punch 42 is directly connected to the upper platen of the press, and the other die 30, the upper outer punch 45, the lower outer punch 25, and the lower inner punch 22 are operated by a cylinder provided with a hydraulic pressure as a driving source provided in the die set. The operating stroke is determined by a stroke end block provided in the die set.

  The operation timing of each mold was controlled by detecting the position in the upper ram stroke with a linear gauge and switching the hydraulic valve by sequence control using the voltage signal as a trigger.

(4) as the target density 1.95 g / cm ³ which performance can be obtained as a separator 1, the reference compression ratio because it is bulk density 0.65 g / cm ³ of the powder material was 3. Therefore, the material filling amount of the surrounding part 4 region of the separator 1 was set to 6 mm from 2 mm × 3. Since the flow channel groove 2 region needs to be reduced by 1.8 mm so that the ratio of the cross-sectional area of the separator 1 to the space cross-sectional area of the cavity 50 is 1: 3, the mold for forming the flow channel groove 2 region The lower inner punch 22 was raised by 1.8 mm, that is, the filling amount was set to 4.2 mm from 6 mm-1.8 mm.

(5) The mold temperature was heated to 60 ° C. in order to improve fluidity, and compressed by 125 tons for 15 seconds by the hydraulic press device.

(6) After the compression molding is completed, the hydraulic valve is opened so that the upper outer punch 45 and the lower outer punch 25 operate in the direction in which the separator 1 is pushed out. At the same time, a release air blow is ejected from the divided portions of the outer punches 45 and 25 and the inner punches 42 and 22.

  If the upper ram of the press is raised by 1 mm while maintaining this state, the upper outer punch 45 and the lower outer punch 24, each having an operating stroke of 0.5 mm, are held with the separator 1 interposed therebetween. The lower inner punch 22 is extracted from the flow channel groove 2 of the separator 1.

  Immediately thereafter, the die 30 is lowered by hydraulic drive, and the outer periphery of the separator 1 is extracted. Thereafter, the removal of the separator 1 is completed by raising the upper ram.

(7) FIG. 14 is a graph showing the pressure transition of the material generated during the compression molding process by installing the pressure sensor in the cavity 30 in the upper inner punch 42 and the upper outer punch 45. The pressure states of the surrounding portion 4 region and the flow channel groove portion 2 region are substantially equal. The density in each region is also 1.97 g / cm ^{3 for the} surrounding portion and 1.95 g / cm ³ for the channel groove portion.

  FIG. 15 is an enlarged view of the corner of the flow channel groove 2 of the separator 1. It can be seen that the mold shape is transferred with high accuracy and that it is easy to take out the product.

(8) On the other hand, FIG. 16 shows a pressure transition when compression molding is performed according to the prior art. Although the pressure increase in the flow channel region is large, the pressure increase in the surrounding region is very large, approximately 1/2 to 1/3. Result, the density in each region surrounding part 1.79 g / cm ^3, a density reduction of and surrounding portion a passage groove 1.98 g / cm ³ becomes prominent.

  FIG. 17 is an enlarged view of the channel groove part corner of the separator. It can be seen that a large release resistance is generated when the separator is taken out, and the corner portion is missing.

  19 shows (a) a front view and (b) a rear view when each part of the fuel cell separator 1 shown in FIG. 1 is viewed in detail, and FIG. 20 is taken along the line XX-XX in FIG. FIG. 21 is a sectional view, FIG. 21 is an enlarged view of part A in FIG. 20, (b) an enlarged view of part B, and (c) an enlarged view of part C.

  When the fuel cell separator 1 is viewed in cross section, most of the fuel cell separator 1 is composed of a flow channel groove portion 2 and a surrounding portion 4 as shown in FIG. And the flow-path groove part 2 is equipped with the flow-path groove | channel 3 on both front and back, as shown in FIG.2 (b).

  However, as shown in FIG. 20 and FIG. 21, the channel groove 3 is formed only on one surface in the portion where each channel groove 3 is connected to the manifold 5, and the opposite surface is a region 6 without the channel groove 3. Exists. That is, when the fuel cell separator 1 is viewed in detail in cross section, a double-sided channel groove part 2 having a channel groove 3 on both sides, a single-sided channel groove part 6 having a channel groove 3 only on one side, and a channel groove part 2 , 6 and a surrounding portion 4 surrounding the periphery. The opposite surface of the single-sided channel groove portion 6 is constituted by the surrounding portion 4.

  Moreover, as shown in FIG. 21 (b), the single-sided flow channel part 6 is enlarged from the B part of FIG. 20, and the single-sided flow channel part 6 having the flow channel 3 only on the lower surface, and the C part of FIG. As shown in FIG. 21 (c), there is a single-sided channel groove portion 6 provided with a channel groove 3 only on the upper surface.

  Such a single-sided channel groove 6 is naturally assigned to the lower inner punch 22 and the upper inner punch 42 in the molding die 10 shown in FIG. In the case of the molding die 10 shown in FIG. 3, the lower punch 21 includes an actuating member (actuator) 24 that advances and retracts the lower inner punch 22 until it comes into contact with the stopper block 23 with respect to the lower outer punch 25. On the other hand, the upper punch 41 does not include such an operating member (actuator). Therefore, before the filling adjustment shown in FIG. 6, after the filling adjustment shown in FIG. 7 and immediately before compression, until the middle of the compression process shown in FIG. 8, and after completion of the compression shown in FIG. 9, the upper inner punch 42 and the upper outer punch 45 The positional relationship does not change.

Still, as shown in FIG. 4, the lower inner punch 22 is raised by a predetermined h dimension with respect to the lower outer punch 25, and the space filled with the material is reduced by the h dimension, so that the surrounding portion of the separator 1 play 4 and the cross-sectional area S _out of a region, the adjustment of the cross-sectional area S _in the flow path groove 2 region, as shown in FIG. 14 realizes the uniformity of the density by the pressure state becomes substantially equal .

  However, as described above, the fuel cell separator 1 includes the double-sided channel groove portion 2 and the surrounding portion 4, the single-sided channel groove portion 6 provided with the channel groove 3 only on the lower surface, and the channel groove only on the upper surface. 3 and a single-sided channel groove portion 6 having 3. Among these, the cross-sectional area of the single-sided channel groove portion 6 provided with the channel groove 3 only on the lower surface is adjusted in advance by the h dimension with the surrounding surrounding portion 4. On the other hand, the single-side flow channel groove portion 6 having the flow channel groove 3 only on the upper surface is not adjusted with such a cross-sectional area with the surrounding surrounding portion 4, and through the compression process. Never done.

By the way, as described above with reference to FIG. 18, when the region of the surrounding portion 4 is set to the compression ratio 3, the region of the channel groove portion (double-sided channel groove portion) 2 has a cross-sectional area of 86.4 mm ² at the time of filling. When the compression stroke is 3 mm, the cross-sectional area is 22.2 mm ² , and the compression ratio of the flow channel groove portion 2 is 3.9 when the cross-sectional area is used as a reference. 30% excess compression ratio. Similarly, the region of the single-sided channel groove 6 has a compression ratio that is 10% excessive relative to the region of the surrounding portion 4.

  That is, in the case of the molding die 10 shown in FIG. 3, on the lower surface side of the separator 1, the region of the single-sided channel groove portion 6 having a different compression ratio from the region of the surrounding portion 4 is also the region of the double-sided channel groove portion 2. In both cases, the cross-sectional area is adjusted in advance by the dimension h, whereas on the upper surface side of the separator 1, not only the area of the single-sided channel groove part 6 but also the area of the double-sided channel groove part 2 are cross-sectional areas. Is not adjusted.

  Therefore, in the initial stage of compression (at the start of compression), the required cross-sectional area is adjusted uniformly on both the lower surface side and the upper surface side of the separator 1 so that the density uniformity of the separator 1 can be improved. The mold will be described below.

  FIG. 22 is a longitudinal sectional view showing a second embodiment of a molding die used in the method of manufacturing the fuel cell separator 1 according to the present invention. For the sake of explanation, FIG. is there. Further, the manifold 5 formed in the surrounding portion 4 and the core that is a mold for forming the through hole for stacking the separator 1 are omitted.

  The molding die 110 includes a lower die (lower punch) 121 provided on the fixed side block 120, an upper die (upper punch) 141 provided on the moving side block 140, and both upper and lower dies 141, 121. And a frame (die) 130 that is a mold that bears the outer periphery of the cavity 150 to be formed. A frame (die) 130 is also provided in the stationary block 120, and the upper mold (upper punch) 141 is operated together with the moving block 140 by ram pressure.

  The lower mold (lower punch) 121 is a lower inner mold (lower punch) that is a mold that forms the shape of the lower surface flow channel groove portions 2 and 6 of the double-sided flow channel groove portion 2 and the single-side flow channel groove portion 6 of the separator 1. (Inner punch) 122 and a lower outer mold (lower outer punch) 125 which is a mold for forming the shape of the surrounding portion 4 region on the lower surface of the separator 1.

  In addition, the lower punch 121 includes an operating member (actuator) 124 that allows the lower inner punch 122 to advance and retract so that the lower inner punch 122 abuts against the stopper block 123 with respect to the lower outer punch 125, and the lower outer punch 122 with respect to the lower inner punch 122. An actuating member (actuator) 127 is provided to advance and retract 125 so as to protrude until it abuts against the stopper block 126.

  The operating force of the actuator 124 that causes the lower inner punch 122 to protrude with respect to the lower outer punch 125 is set to such a magnitude that the protrusion of the lower inner punch 122 is substantially eliminated at the end of the compression process due to the ram pressure. It is what is done.

  Further, the lower punch 121 is arranged so that when the mold is opened, the lower outer punch 125 protrudes from the lower inner punch 122 so that the channel grooves 2 and 6 on the lower surface of the separator 1 can be easily released. A lower punch air blow line 128 for ejecting compressed air from a split surface with the lower outer punch 125 is provided.

  The upper mold (upper punch) 141 is an upper inner mold (upper mold) that is a mold that forms the shape of the upper surface channel groove portions 2 and 6 of the double-sided channel groove portion 2 and the single-sided channel groove portion 6 of the separator 1. The inner punch 142 is divided into an upper outer mold (upper outer punch) 145 which is a mold for forming the shape of the surrounding portion 4 region on the upper surface of the separator 1.

  Further, the upper punch 141 has an operating member (actuator) 144 that allows the upper inner punch 142 to advance and retract so as to protrude until it comes into contact with the stopper block 143 with respect to the upper outer punch 145, and an upper outer punch 142 with respect to the upper inner punch 142. An actuating member (actuator) 147 is provided to advance and retract 145 until it abuts against the stopper block 146.

  The operating force of the actuator 144 that causes the upper inner punch 142 to protrude with respect to the upper outer punch 145 is set to such a magnitude that the protrusion of the upper inner punch 142 is substantially eliminated at the end of the compression stroke by the ram pressure. It is what is done.

  Further, the stroke of the upper outer punch 145 projecting from the upper inner punch 142 by the actuator 147 and the stroke of the lower outer punch 125 projecting from the lower inner punch 122 by the actuator 127 are the front and back surfaces of the separator 1. The channel groove portions 2 and 6 are set to be slightly larger than the same dimension as the depth.

  Further, the upper punch 141 is arranged so that the channel grooves 2 and 6 on the upper surface of the separator 1 are easily released when the upper outer punch 145 protrudes from the upper inner punch 142 when the mold is opened. An upper punch air blow line 148 for ejecting compressed air from a split surface with the upper outer punch 145 is provided.

  The frame (die) 130 is provided with an operating member (actuator) 132 that moves forward and backward so that the upper surface of the frame (die) is lower than the upper surface of the lower punch 121 until it contacts the stopper block 131.

  The molding die 110 has a die 130, a lower inner punch 122, a lower outer punch 125, an upper inner punch 142, and an upper outer punch 145 by a function of a pressing device (not shown) and a die setting function for holding the die. Each mold is operably held in the compression molding direction. And as shown by the arrow P in FIG. 22, it is compression-molded by the uniaxial molding from a perpendicular direction with respect to the plane part which has the largest area of the separator 1. FIG.

  Note that the mold configuration shown in FIG. 22 is an example, and depending on the depth, width, and pitch of the channel grooves 3 formed in the double-sided channel groove portion 2 and the single-sided channel groove portion 6 of the separator 1, the lower punch 121, It is also possible to omit part of the operation of the upper punch 141. Further, depending on the shape of the separator 1, it is possible to cope with any mold dividing position and any number of mold configurations.

  Since the molding die 110 according to the present invention has a structure in which the punch is divided into the double-sided channel groove portion 2 region and the single-sided channel groove portion 6 region and the surrounding portion 4 region of the separator 1 as described above. The following molding process is possible.

  In compression molding using a powder material, the material filling amount in the cavity 150 is determined using the ratio between the target density of the compression molded product and the bulk density of the material as the compression ratio. In particular, in the case of a material having poor fluidity, the variation in the partial compression ratio of the molded product becomes the variation in density as it is, and the quality is greatly deteriorated. The filling method in the powder material compression press molding method generally eliminates excessively charged material with reference to the upper surface of the die and suppresses variation in the filling amount.

  FIG. 23 is a longitudinal sectional view of the main part showing a state where the cavity 150 of the molding die 110 is filled with a powder material.

  FIG. 24 shows a longitudinal sectional view of the separator 1 which is a compression molded product. 23 and 24 are the same cross-sectional position.

In the manufacturing process using the molding die 110 according to the present invention, when the ratio between the target density and the bulk density of the powder material, that is, the compression ratio is assumed to be 3, the cross-sectional area S _out of the surrounding portion 4 region of the separator 1 is since thickness is Tmm, by providing a space having a sectional area of 3 × S _out by causing the die 130 is 3 × Tmm rise from the lower punch 121 top, proper material is filled.

  At this time, since the upper surface of the lower outer punch 125 is flat, an ideal material can be filled.

On the other hand, the cross-sectional area Sin of the double-sided channel groove portion 2 region and the single-sided channel groove portion 6 region of the separator 1 is that of the mold convex portion for forming the channel groove 3 when the die 130 is raised by 3 × T mm. material corresponding to the formation of cross-sectional area becomes surplus material filled on both sides flow passage groove part 2 area and one side flow passage groove part 6 area exceeds 3 × S _in.

  Therefore, in the manufacturing process using the molding die 110 according to the present invention, in order to prevent the excessive filling of the material, the space in which the flow channel 3 on the upper punch 141 side and the lower punch 121 side is formed is as follows. Therefore, the cross-sectional area can be adjusted to 3 × Sin.

  That is, the upper inner punch 142 forming the upper punch side passage groove 3 of the separator 1 is protruded (lowered) by a predetermined Hu dimension with respect to the upper outer punch 145 forming the upper punch side surrounding portion 4, The material filling amount corresponding to the upper punch side channel groove 3 is reduced.

  Similarly, the lower inner punch 122 that forms the lower punch side passage groove 3 of the separator 1 is protruded (raised) by a predetermined H1 dimension with respect to the lower outer punch 125 that forms the lower punch side surrounding portion 4. The material filling amount corresponding to the lower punch side passage groove 3 is reduced.

  Further, by adding the Hu dimension of the upper inner punch 142 that protrudes (lowers) forming the upper punch side flow channel groove 3 to the protrusion (upward) of the lower inner punch 122, the upper punch 141 side and lower The space in which the flow channel 3 on the punch 121 side is formed is reduced by the (Hu + Hl) dimension.

Moreover, since the (Hu + Hl) dimension is arbitrarily adjustable with respect to the density of _{S out} portion is a surrounding section 4, the density of _{S in} part a flow path groove 2,6 relatively controllable and is there. Both densities can be made uniform, and if necessary, the density of the channel grooves 2 and 6 can be increased or decreased relative to the density of the surrounding part 4.

  FIGS. 25 to 28 show the process of compression molding in the method of manufacturing a fuel cell separator using the molding die 110 according to the present invention, FIG. 25 is the state before filling adjustment, and FIG. 26 is the state just before compression after filling adjustment. FIG. 27 is a longitudinal sectional view showing the state, FIG. 27 is a state in the initial stage of compression, and FIG.

  In order to reduce the density variation of the separator 1 as a whole, during the compression process, the compression speed of the flow path groove portions 2 and 6 region with a small amount of material filling and the compression speed of the surrounding portion 4 region are equalized, that is, from the start of compression. By ending the process up to the completion of compression almost simultaneously, it is possible to eliminate quality variations in both the areas 2 and 6 and the area 4.

  Specifically, the lower inner punch 122 is floated with a holding force smaller than the compressive force of the upper ram by the driving force of the actuator 124 such as air pressure, hydraulic pressure, a spring, and an electric motor, and the compressive force on the upper punch 141 side. It is preferable to descend at a slightly slower speed than the upper punch 141 side.

  Similarly, the upper inner punch 142 is floated in the compression direction with a holding force smaller than the compression force of the upper ram by the driving force of the actuator 144 such as pneumatic, hydraulic, spring, electric motor, etc., and compressed on the upper punch 141 side. It is preferable to relatively raise at a state where it can be relatively raised according to the force, or at substantially the same speed as the lowering speed of the lower inner punch 122.

  As a result, the compression speed can be delayed even in a region where the filling amount is small, that is, a region where the compression stroke is short.

  FIG. 26 shows a state after filling adjustment and immediately before compression in which the filling amount for enabling a uniform compression ratio is ensured in the cavity 150 regardless of the cross-sectional shape of the separator 1. At this time, the lower inner punch 122 is in a position protruding (raised) by (Hu + Hl) dimensions with respect to the lower outer punch 125. On the other hand, the upper inner punch 142 is in a position protruding (lowered) by the Hu dimension with respect to the upper outer punch 145. The upper punch 141 is at a height at which the lower end of the upper inner punch 142 is in contact with the upper surface of the powder material filled in the cavity 150 immediately before compression.

  FIG. 27 shows the initial state of compression. Here, the transition from the state shown in FIG. 26 to the state shown in FIG. 27 will be described. That is, at the time of this transition, the lower surface of the upper outer punch 145 is lowered to a height in contact with the upper surface of the powder material filled in the cavity 150 by the compressive force on the upper punch 141 side (upper ram). At this time, while the driving force of the actuator 144 is maintained, the driving force of the actuator 124 is reduced, and the upper inner punch 142 follows the pressing force pressing the powder material filled in the cavity 150 downward, and lowers the driving force. The inner punch 122 is lowered.

  Accordingly, as shown in FIG. 27, the upper inner punch 142 is in a position protruding (lowering) by the Hu dimension from the upper surface of the powder material filled in the cavity 150, while the lower inner punch 122 is in the cavity 150. It is in a state where it protrudes (rises) by the amount of H1 from the bottom surface of the powder material filled in.

  That is, the state of the upper punch 141 on the upper surface side of the powder material filled in the cavity 150 (the protruding amount of the upper inner punch 142 with respect to the upper outer punch 145: Hu), and the lower surface on the lower surface side of the powder material filled in the cavity 150 The state of the punch 121 (the amount of protrusion of the lower inner punch 122 with respect to the lower outer punch 125: Hl) coincides with each other.

  And from this state, the compression process of the powder material by the compression force on the upper punch 141 side (upper ram) is substantially started. In this compression step, the surrounding portion 4 area is compression-molded by directly receiving the compressive force of the upper ram, while the lower inner punch 122 of the flow path groove portions 2 and 6 is lowered (retracted) while the upper inner punch 142 Is compressed while being relatively raised.

  FIG. 28 shows the compression completion state. The lower inner punch 122 is in the lower limit position, that is, in a state flush with the lower outer punch 125 (or a predetermined position) by the press compression force of the upper ram larger than the holding force by the actuator 124. Further, the upper inner punch 142 is in the ascending limit position, that is, flush with the upper outer punch 145 (or a predetermined position) by the press compression force of the upper ram larger than the holding force by the actuator 144. And the separator 1 is shape | molded.

  In the manufacturing process using the molding die 110 according to the present invention, the process of taking out the product after molding is the same as in the case of the first embodiment, and therefore illustration and description thereof are omitted. That is, in the process of taking out the product after molding, refer to FIG. 10 for the state immediately before taking out, refer to FIG. 11 for the state of extracting the channel groove, and refer to FIG. This state can be understood with reference to FIG. These FIGS. 10 to 13 can be understood more easily by referring to the reference numerals obtained by adding 100 to each reference numeral.

  When the fuel cell separator 1 is manufactured using the molding die 110 according to the second embodiment, the separator is compared with the case where the fuel cell separator 1 is manufactured using the molding die 10 according to the first embodiment. The uniformity of the density of 1 can be further improved.

  Hereinafter, the molding process of the fuel cell separator that is compression-molded by the manufacturing method according to the present invention using the molding die 110 of the second embodiment will be specifically described. However, the present invention is not limited to these examples.

(1) The shape of the separator 1 is 150 mm in length, 100 mm in width, 2 mm in thickness (or 2.5 mm), the gas channel groove 3 is 1 mm in width, 0.5 mm in depth, and the pitch is 2 mm. Placed in the center of

(2) The powder material used was a mixture of 0.15% ash, 80 wt% spherical natural graphite (or similar artificial graphite) having an average particle diameter of 30 μm, and the resin binder was a 20 wt% resol type phenol. The bulk density is 0.65 g / cm ³ .

(3) An upper ram descending type 400-ton hydraulic press was used as the compression molding apparatus. The die 130, the upper outer punch 145, the upper inner punch 142, the lower outer punch 125, and the lower inner punch 122 are operated by a cylinder that uses hydraulic pressure provided in the die set as a driving source, and the operation stroke is provided in the die set. Determined by the stroke end block.

  The operation timing of each mold was controlled by detecting the position in the upper ram stroke with a linear gauge and switching the hydraulic valve by sequence control using the voltage signal as a trigger.

(4) as the target density 1.95 g / cm ³ which performance can be obtained as a separator 1, the reference compression ratio because it is bulk density 0.65 g / cm ³ of the powder material was 3. Therefore, the material filling amount of the surrounding part 4 region of the separator 1 was set to 6 mm from 2 mm × 3.

  In the channel groove portions 2 and 6, the upper surface side channel groove portion 2 is 0.9 mm and the lower surface side channel groove portion 2 is also set so that the ratio of the sectional area of the separator 1 to the space sectional area of the cavity 150 is 1: 3. Since it is necessary to reduce 0.9 mm, the protruding amount (lowering amount) of the upper inner punch 142 with respect to the upper outer punch 145 is set to 0.9 mm, while the protruding amount (upward) of the lower inner punch 122 with respect to the lower outer punch 125 is set. Amount) was also set to 0.9 mm.

  Then, by adding the projecting amount of 0.9 mm of the upper inner punch 142 and projecting the lower inner punch 122 by a total of 1.8 mm, the material filling amount of the flow channel groove part 2 region is 4 mm to 4 mm. Set to 2 mm.

(5) The mold temperature was heated to 60 ° C. in order to improve fluidity, and compressed by 125 tons for 15 seconds by the hydraulic press device.

(6) After the compression molding is completed, the hydraulic valve is opened so that the upper outer punch 145 and the lower outer punch 125 operate in the direction in which the separator 1 is pushed out. At the same time, release air blow is ejected from the divided portions of the outer punches 145 and 125 and the inner punches 142 and 122.

  When the upper ram of the press is raised by 1 mm while maintaining this state, the upper outer punch 145 and the lower outer punch 124, each of which has an operating stroke of 0.5 mm, remain sandwiched between the upper inner punch 142 and the upper outer punch 145. The lower inner punch 122 is extracted from the flow channel groove 2 of the separator 1.

  Immediately thereafter, the die 130 is lowered by hydraulic drive, and the outer periphery of the separator 1 is extracted. Thereafter, the removal of the separator 1 is completed by raising the upper ram.

(7) In the case of this embodiment as well, the cavity pressure transition as shown in FIG. 14 is obtained as in the first embodiment, and the pressure state in the surrounding portion 4 region and the flow channel groove portions 2 and 6 regions becomes substantially equal. ing. The density in each region is also 1.97 g / cm ^{3 for the} surrounding portion and 1.95 g / cm ³ for the channel groove portion.

  Further, a product shape as shown in FIG. 15 is obtained, and the mold shape is transferred with high accuracy, and it can be seen that product removal is easy.

It is (a) front view and (b) back view which show one Embodiment of the fuel cell separator by this invention. It is (a) sectional drawing taken along the II-II line of FIG. 1, and (b) The enlarged view of the A section. It is a longitudinal cross-sectional view which shows 1st Embodiment of the shaping die of the fuel cell separator by this invention. It is a longitudinal cross-sectional view of the principal part which shows the state which filled the powder material in the cavity of the shaping die. The longitudinal cross-sectional view of the separator which is a compression molded product is shown. It is a longitudinal cross-sectional view which shows the state before the filling adjustment in the process of compression molding in the manufacturing method of the fuel cell separator by this invention. It is a longitudinal cross-sectional view which shows the state just before compression after the filling adjustment in the process of compression molding. It is a longitudinal cross-sectional view which shows the state in the middle of the compression process in the process of compression molding. It is a longitudinal cross-sectional view which shows the state of the completion of compression in the process of compression molding. It is a longitudinal cross-sectional view which shows the state just before taking out in the process of taking out the product after shaping | molding. It is a longitudinal cross-sectional view which shows the state which extracts the flow-path groove part in the process of the product taking-out after shaping | molding. It is a longitudinal cross-sectional view which shows the state which the die | dye in the process of taking out the product after shaping | molding fell. It is a longitudinal cross-sectional view which shows the state of the completion | finish of mold opening in the process of the product taking-out after shaping | molding. It is a graph which shows the quality of the fuel cell separator manufactured by this invention. FIG. 15 is a state diagram of the fuel cell separator of FIG. 14. It is a graph which shows the quality of the fuel cell separator manufactured by the prior art. FIG. 17 is a state diagram of the fuel cell separator of FIG. 16. It is the schematic diagram which showed the cross-sectional area at the time of filling in the conventional compression molding, and the cross-sectional area after compression. It is (a) front view and (b) rear view which show other embodiment of the fuel cell separator by this invention. It is sectional drawing taken along the XX-XX line of FIG. It is the enlarged view of the (a) A part of FIG. 20, (b) the enlarged view of the B part, and (c) the enlarged view of the C part. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the shaping die of the fuel cell separator by this invention. It is a longitudinal cross-sectional view of the principal part which shows the state which filled the powder material in the cavity of the shaping die. The longitudinal cross-sectional view of the separator which is a compression molded product is shown. It is a longitudinal cross-sectional view which shows the state before the filling adjustment in the process of compression molding in the manufacturing method of the fuel cell separator by this invention. It is a longitudinal cross-sectional view which shows the state just before compression after the filling adjustment in the process of compression molding. It is a longitudinal cross-sectional view which shows the state of the compression initial stage in the process of compression molding. It is a longitudinal cross-sectional view which shows the state of the completion of compression in the process of compression molding.

Explanation of symbols

1 Fuel cell separator 2 Channel groove (double-sided channel groove)
3 Channel groove 4 Enclosure 5 Manifold 6 Single-sided channel groove 10, 110 Molding die 20, 120 Fixed side block 21, 121 Lower punch (lower die)
22,122 Lower inner punch (lower inner mold)
23, 123 Stopper block 24, 124 Actuator (actuating member)
25,125 Lower outer punch (lower outer mold)
26, 126 Stopper block 27, 127 Actuator (actuating member)
28,128 Lower punch air blow line 30,130 Die (frame)
31, 131 Stopper block 32, 132 Actuator (actuating member)
40,140 Moving block 41,141 Upper punch (upper die)
42,142 Upper inner punch (Upper inner mold)
43,143 Stopper block 144 Actuator (actuating member)
45,145 Upper outer punch (Upper outer mold)
46,146 Stopper block 47,147 Actuator (actuating member)
48,148 Upper punch air blow line 50,150 Cavity

Claims (6)

A method of manufacturing a fuel cell separator having a flow channel groove portion and an surrounding portion on at least one side by compression molding a powdery material using a mold,
After compression molding by one mold and the other mold located on the one side and divided into an inner mold corresponding to the flow channel groove and an outer mold corresponding to the surrounding part, A fuel cell separator, wherein the outer mold protrudes from the inner mold so that the flow path groove part is released prior to the surrounding part when the mold is opened for taking out a molded product. Manufacturing method. A method of manufacturing a fuel cell separator having a flow channel groove portion and an surrounding portion on at least one side by compression molding a powdery material using a mold,
One mold, the other mold that is located on one side and is divided into an inner mold corresponding to the flow channel groove and an outer mold corresponding to the surrounding part, and the both molds The inner mold so that the flow channel groove part is released prior to the surrounding part at the time of mold opening for taking out a molded product after compression molding with a frame body that bears the outer periphery of the cavity formed therebetween Project the outer mold against
A method of manufacturing a fuel cell separator, wherein the outer periphery of a molded product is released from the frame body by moving the frame body in a state where the flow channel groove portion is released and the surrounding portion is not released. . When the mold is opened, when the outer mold is protruded from the inner mold so that the flow path groove part is released prior to the surrounding part, the flow path groove part is easily released from the mold. The method for producing a fuel cell separator according to claim 1 or 2 , wherein compressed air is ejected from a dividing surface of the inner mold and the outer mold. A method of manufacturing a fuel cell separator having a flow channel groove portion and a surrounding portion on both front and back surfaces by compression molding a powdery material using a mold,
After compression molding with an upper mold and a lower mold divided into an upper inner mold and a lower inner mold corresponding to the flow path groove part, and an upper outer mold and a lower outer mold corresponding to the surrounding part, When opening the mold for taking out a molded product, the upper outer mold and the lower inner mold are separated from the upper outer mold so that the flow channel groove part is released prior to the surrounding parts on the front and back surfaces. A method for producing a fuel cell separator, wherein a mold and the lower outer mold are projected. After compression molding with the upper mold and the lower mold, and a frame that bears the outer periphery of the cavity formed between the two molds, when the mold is opened for taking out a molded product, the upper inner mold and the mold For the lower inner mold, the upper outer mold and the lower outer mold are projected,
The outer periphery of the molded product is released from the frame body by moving the frame body in a state in which the flow channel grooves on the front and back surfaces are released and the surrounding portions on the front and back surfaces are not released. The method for producing a fuel cell separator according to claim 4 . When the mold is opened, when the upper outer mold and the lower outer mold protrude from the upper inner mold and the lower inner mold, the flow channel grooves on the front and back surfaces are easily released. to claim 4 or claim 5 fuel, wherein the ejecting the compressed air from the dividing plane between the upper inner die and the upper outer die and said lower outer mold and the lower inner mold A method for producing a battery separator.