JP5061470B2 - Inspection method and manufacturing method of fuel cell separator - Google Patents

Description

  The present invention relates to an inspection method and a manufacturing method for a fuel cell separator.

  A single cell of a fuel cell has a separator for separating a fuel gas from an oxidant gas or the like. A separator has a channel groove for circulating fuel gas, oxidant gas, etc., and is manufactured by press-molding a powdery molding material (for example, refer to patent documents 1).

Then, before the stack, density quality (gas impermeability) is managed by using a completed separator and performing a color check inspection using a penetrant.
JP 2003-17085 A

  However, the color check inspection is destructive, and a separator coated with a penetrant cannot be used as a product. For this reason, in the gas permeation inspection after stacking, if a defect in density quality is found, there is a problem that a manufacturing cost is lost due to disposal or a huge work cost is required for repair. .

  The present invention has been made in order to solve the problems associated with the prior art described above, and has an inspection method capable of 100% inspection of density quality when manufacturing a separator for a fuel cell, and good density quality. It aims at providing the manufacturing method of the separator for fuel cells which has.

In order to achieve the above object, the invention described in claim 1
When a fuel cell separator is produced from a powdery molding material containing graphite and a binder resin, based on temperature characteristics, the binder resin is inspected as a preformed body made of the molding material in an uncured state. Inspect the density quality of the object ,
The temperature characteristic comprises temporal change information of the temperature distribution of the surface of the inspection object when the temperature of the inspection object heated temporarily decreases.
In the inspection, when the local temperature difference obtained from the temporal change information exceeds a predetermined threshold, the density quality is determined to be poor .

In order to achieve the above object, the invention described in claim 8 provides:
A method for producing a separator for a fuel cell to which a powdery molding material containing graphite and a binder resin is applied,
A preforming step for forming a preform formed of the molding material in which the binder resin is in an uncured state;
Based on the temperature characteristics, it has a, and inspection process for inspecting the density quality of the inspection object consisting of the preform,
The temperature characteristic comprises temporal change information of the temperature distribution of the surface of the inspection object when the temperature of the inspection object heated temporarily decreases.
In the inspection step, when the local temperature difference obtained from the time-dependent change information exceeds a predetermined threshold, the density quality is determined to be poor. is there.

  According to the first aspect of the present invention, the density quality is inspected based on the temperature characteristics when the fuel cell separator is manufactured. Since the temperature characteristics can be inspected nondestructively, it is possible to apply a 100% inspection. That is, when manufacturing a fuel cell separator, an inspection method capable of 100% inspection of density quality can be provided.

According to invention of Claim 8 , it has an inspection process for inspecting density quality based on a temperature characteristic. The temperature characteristic can be examined non-destructively. Therefore, for example, when 100% inspection is applied, it is possible to reliably manufacture a fuel cell separator having good density quality. That is, the manufacturing method of the separator for fuel cells which has favorable density quality can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view for explaining the fuel cell according to Embodiment 1, and FIG. 2 is an exploded view for explaining the structure of the single cell of FIG.

  The fuel cell 10 has a stack unit 20 in which single cells 30 are stacked, and is used as a power source. Applications of the power source include, for example, stationary devices, consumer portable devices such as mobile phones, emergency devices, outdoor devices such as leisure and construction power sources, and mobile objects such as automobiles with limited mounting space. In particular, the mobile power supply is preferably applied because a high output voltage is required after a relatively long period of shutdown.

  The single cell 30 is a battery that can obtain electricity by reacting a fuel gas (for example, hydrogen) and an oxidant gas (for example, oxygen) by utilizing the reverse principle of water electrolysis, and is a stack. The end plates 40 disposed on both sides of the unit 20 have a fuel gas inlet 50 and an outlet 52 for circulating fuel gas, and an oxidant gas inlet 60 and an outlet 62 for circulating oxidant gas. .

  In addition, the end plate 40 includes a refrigerant inlet 70 for circulating a cooling medium (for example, water) in order to keep the temperature of the fuel cell 10 raised by heat generated during power generation within a predetermined operating temperature range. A discharge port 72 is provided.

  The single cell 30 includes a membrane electrode assembly (MEA) 32 and a separator 38. As will be described later, the separator 38 has a good density quality.

  The membrane electrode assembly 32 includes an electrolyte membrane 34, a cathode electrode (air electrode) 35 and an anode electrode (fuel electrode) 36 disposed with the electrolyte membrane interposed therebetween.

  The electrolyte membrane 34 is a proton conductive ion exchange membrane formed of a solid polymer material, for example, a fluorine resin, and exhibits good electrical conductivity in a wet state. The thickness of the electrolyte membrane is appropriately set in consideration of strength during film formation, durability during operation, and output characteristics during operation.

  The cathode electrode 35 is disposed on one surface of the electrolyte membrane 34 and has a cathode catalyst layer and a gas diffusion layer. The anode electrode 36 is disposed on the other surface of the electrolyte membrane, and has an anode catalyst layer and a gas diffusion layer.

  The separator 38 has a groove (not shown) and is disposed on the outer surface of the gas diffusion layer. The groove portion is used for circulating the fuel gas, the oxidant gas, or the cooling medium depending on the position where it is disposed, and the fuel gas inlet 50 and the outlet 52, the oxidant gas inlet 60 and the outlet 62, or It communicates with the refrigerant inlet 70 and the outlet 72.

  The separator 38 is a molded body containing a binder resin made of a thermosetting resin and graphite as a conductive powder, and the binder resin content is, for example, 10 to 30 wt%, and the graphite content. Is the remainder (90-30 wt%). The binder resin is contained in the molded body in a state of being thermoset.

  The graphite is, for example, natural graphite, artificial graphite, or expanded graphite.

  The thermosetting resin is, for example, a phenol resin, a melamine resin, or a polyamide resin. Phenol resins are preferred because they are excellent in economic efficiency, workability, moldability, physical properties (acid resistance, heat resistance, fluid impermeability) and the like.

  FIG. 3 is a process diagram for explaining a method of manufacturing the separator shown in FIG.

  The separator manufacturing method according to Embodiment 1 includes a preliminary forming step, an inspection step including a primary determination step, and a secondary determination step, and a main forming step.

  In the preforming step, a preformed body made of a molding material in which the binder resin is in an uncured state is formed. In the inspection process, the density quality is inspected based on the temperature characteristics when the temperature change is caused with the preform as an inspection object. In the main molding step, the pre-inspected body after the inspection is pressed and compressed at a temperature equal to or higher than the thermosetting temperature of the binder resin.

  Since the temperature characteristic can be inspected nondestructively, it is possible to apply a total inspection, for example. In this case, it is possible to reliably manufacture a separator having a good density quality. Therefore, in the gas permeation inspection after stacking of the completed separator, it is possible to suppress the discovery of defects in density quality, and it is possible to reduce loss of manufacturing costs due to disposal and enormous work costs for repairing. It is.

  Next, a method for manufacturing the separator according to Embodiment 1 will be described in detail.

  FIG. 4 is a schematic view for explaining a preforming apparatus used in the preforming step shown in FIG.

  The preforming apparatus 100 includes a filling jig 110 and a heating furnace 115, and is used for forming a preformed body by increasing the temperature of the molding material M and aggregating (temporarily curing) it.

  The filling jig 110 is portable, and the cavity of the filling jig 110 filled with the molding material M is set to reflect the compression ratio of the final molding shape in the main molding process. That is, the cavity of the filling jig 110 has a rectangular shape substantially corresponding to the outer periphery of the separator, and the bottom thereof has a convex portion 112 substantially corresponding to a groove portion disposed on one surface of the separator.

  The heating furnace 115 includes a pedestal 116 on which a filling jig 110 that holds the molding material M is disposed, and a heating device 117. The heating device 117 includes a cartridge heater disposed in the vicinity of the base 116, heats the filling jig 110 and the molding material M, and aggregates the molding material M at an appropriate temperature lower than the thermosetting temperature of the binder resin. Used for.

  FIG. 5 is a cross-sectional view for explaining filling of the molding material M according to the preforming step shown in FIG.

  In the pre-forming step, the outlet 105 of the piping system connected to the storage tank (not shown) for the molding material M is moved from the standby position and disposed above the filling jig 110. The outlet 105 repeats the movement while discharging the molding material M, and arranges the molding material M evenly over the entire cavity of the filling jig 110.

  When the supplied molding material M matches the amount required to form the separator, the ejection of the molding material M is stopped, and the outlet 105 returns to the standby position. The surface of the molding material M disposed on the filling jig 110 is scraped off.

  Thereafter, the filling jig 110 that holds the molding material M is disposed on the pedestal 116 of the heating furnace 115. The heating furnace 115 operates the heating device 117, heats the filling jig 110 and the molding material M, and agglomerates the molding material M at an appropriate temperature lower than the thermosetting temperature of the binder resin. Form. That is, a preformed body made of the molding material M in which the binder resin is in an uncured state is formed. And a preforming body is thrown into a primary determination process.

  It is possible to shorten the time required for agglomerating the molding material M and improve the time cycle by operating the heating device 117 in advance and raising the temperature of the heating furnace 115.

  FIG. 6 is a schematic diagram for explaining a primary inspection apparatus used in the primary determination step shown in FIG.

  The primary inspection apparatus 120 is used for inspecting the density quality based on the temperature characteristics by applying the thermography method using the preform P inputted from the preforming process as an inspection object. It has a device 124, a housing 126, a control device 130 and a display device 132.

  The heating device 122 includes, for example, a flash lamp that irradiates the preform P with a heat pulse (flash light) of several milliseconds, and is used to temporarily heat the preform P. Note that the heating device 122 is not limited to a mode in which a flash lamp is applied.

  The image device 124 is an infrared camera having a condenser lens and a temperature sensor connected to the control device 130, detects infrared rays emitted from the surface of the preform P, and controls the infrared radiation energy data. Used to transmit to device 130.

  The housing 126 has a base 128 on which the filling jig 110 that holds the preform P is disposed. A heating device 122 and an image device 124 are fixed to the upper portion of the housing 126.

  The control device 130 is a computer connected to the display device 132 and having an image processing program and a control program installed therein. The image processing program is used for acquiring the temperature characteristics of the preform P and inspecting the density quality based on the temperature characteristics. The control program is used to control the heating device 122 and the image device 124. Note that the control device 150 is not limited to a general-purpose computer in which an image processing program and a control program are installed, and can be configured as a dedicated processing device.

  The temperature characteristic of the inspection object is a temperature lowering characteristic of the preform P that is temporarily heated, and is a preliminary obtained by converting the amount of infrared radiation energy transmitted with time from the image device 124 into temperature. It consists of time-dependent change information of the temperature distribution on the surface of the molded body P. The temperature characteristics are not limited to the temperature lowering characteristics of the preform P.

  The display device 132 includes a display panel 134 made of a cathode ray tube or liquid crystal, and is used to display visualization data (infrared thermal image) of temperature change information with time. The visualization data is, for example, a color image in which a temperature is associated with a gradation and a color is assigned to each pixel of the display panel 134 according to the temperature.

  FIG. 7 is a graph for explaining the inspection of the density quality based on the temperature decrease characteristic, and shows a temperature change curve. The vertical axis is the surface temperature, and the horizontal axis is the elapsed time (seconds).

  The temperature distribution on the surface of the preform P when the temperature of the temporarily heated preform P decreases is related to the density distribution, and the local temperature difference obtained from the temperature distribution is the local density difference. It corresponds to. Therefore, by managing the local temperature difference, the density quality of the separator completed from the preform P can be maintained well.

  When the local temperature difference exceeds a predetermined threshold, it can be determined that the local density difference in the preform P is too large and the density quality of the separator completed from the preform P is poor. For example, the threshold is prepared by preparing a preform P having different local density differences and acquiring the local temperature difference, while checking the density quality of the separator completed from the preform P, and determining the local temperature. It can be set by obtaining the relationship between the difference and the quality of the density quality.

  The local temperature difference changes as the surface temperature decreases, and is related to the surface temperature. The local temperature difference is not constant, but changes according to the surface temperature and the time of measurement. Therefore, it is preferable to use the surface temperature at the time when the local temperature difference becomes large as the reference temperature for measuring the local temperature difference. That is, when the surface temperature reaches the reference temperature, the local temperature difference is measured, and when the local temperature difference is applied to the determination of the density quality, the quality of the density quality can be measured more accurately. it can.

  Next, the primary determination process will be described.

  In order to inspect the density quality, the preform P prepared in the preforming process is put into the housing 126 of the primary inspection device 120 while being held by the filling jig 110 and placed on the base 128. Is done.

  The heating device 122 irradiates the preform P with a heat pulse in accordance with an instruction from the control device 130 to temporarily heat the preform P.

  The image device 124 detects the infrared rays radiated from the surface of the preform P in a non-contact manner, and transmits the radiant energy data of the infrared rays to the control device 130 over time.

  In accordance with an instruction from the control device 130, the control device 130 converts the amount of infrared radiation energy transmitted from the image device 124 into a temperature, and acquires the temperature distribution on the surface of the preform P. The visualization data of the temporal change information of the temperature distribution is displayed on the display panel 134 as a color image as necessary.

  When the local temperature difference obtained from the temperature distribution at the time when the surface temperature reaches the reference temperature is equal to or less than a predetermined threshold value, it is determined that the local density difference in the preform P is good, and the preform P Is transferred to the secondary determination step. On the other hand, when the local temperature difference exceeds a predetermined threshold, it is determined that the filling of the molding material M is inappropriate, and the density quality of the separator completed from the preform P is determined to be poor. The transfer of the preform P to is stopped.

  In the density inspection of the separator after completion, the filled molding material M is thermally cured through the main molding process, and it is difficult to accurately feed back the defect information on the local density difference to the preliminary molding process. However, since the binder resin contained in the preform P according to Embodiment 1 is in an uncured state, the defect information on the local density difference in the preform P is accurate.

  Therefore, the preform P having a good local density difference can be easily obtained by immediately feeding back to the preforming process and adjusting the filling of the molding material M. In addition, when the preform P is destroyed and returned to the powdery molding material M for reuse, the basic unit can be improved.

  Next, the secondary determination step and the main forming step will be described.

  FIG. 8 is a schematic diagram for explaining a secondary inspection apparatus used in the secondary determination step shown in FIG. 3, and FIG. 9 is for explaining the main forming apparatus related to the main forming step shown in FIG. FIG.

  The secondary determination step is provided for inspecting a defect that occurs when the preform P is removed from the filling jig 110 and placed in the main mold, and is placed in the main mold. The density quality of the preform P is inspected.

  Therefore, the secondary inspection apparatus 140 is different from the primary inspection apparatus 120 in that it has a movable arm 146 instead of the fixed housing 126, and the inspection object is input from the primary determination step, and the filling treatment is performed. It is a preformed body removed from the tool 110. In addition, about the member which has the same function as in the primary inspection apparatus 120, the same code | symbol is used and in order to avoid duplication, the description is abbreviate | omitted.

  The movable arm 146 includes a front end frame 148 to which the heating device 142 and the image device 144 are fixed, and a main body 149 to which the front end frame 148 is connected and fixedly arranged. The main body 149 has a driving means made of, for example, a hydraulic cylinder device, and can drive the distal end frame 148. Reference numerals 150, 152, and 154 denote a control device, a display device, and a display panel.

  The main molding apparatus 160 includes an upper mold 162 and a lower mold 166 that constitute the main mold, heating apparatuses 172 and 176, a pressurizing mechanism 180, and a control apparatus 185. The preform P after the secondary inspection is bonded to a binder. It is used to form a separator by pressing and compressing at a temperature equal to or higher than the thermosetting temperature of the resin.

  The upper mold 162 is disposed so as to be able to approach and separate from the lower mold 166. The lower mold 166 is disposed in a fixed manner. The cavity of the upper mold 162 has a convex portion 163 corresponding to the shape of the other surface of the separator and corresponding to the groove portion arranged on the other surface. The cavity of the lower mold 166 has a convex portion 167 corresponding to the shape of one surface of the separator and corresponding to the groove portion disposed on the one surface.

  Therefore, the cavity of the upper mold 162 and the cavity of the lower mold 166 integrally correspond to the outer shape of the separator. In addition, when the other surface of the manufactured separator is flat, the cavity of the upper mold 162 is flat correspondingly.

  The heating devices 172 and 176 include cartridge heaters disposed inside the upper mold 162 and the lower mold 166, and are used to heat the upper mold 162 and the lower mold 166. The heated upper mold 162 and lower mold 166 raise the temperature of the preform P after the secondary inspection by heat supplied by heat transfer to reach an appropriate temperature not lower than the thermosetting temperature of the binder resin. .

  The heating device 172 of the upper mold 162 can be omitted if necessary. The heating devices 172 and 176 are not limited to forms using resistance heating, and heating fluid such as high-temperature oil, electromagnetic induction heating, ultrasonic heating, or the like can be applied as appropriate.

  The pressurizing mechanism 180 has, for example, a hydraulic cylinder device, drives the upper die 162 in cooperation with the lower die 166, and converts the preform P in the temperature rise state by the heating devices 172 and 176 into the upper die. 162 and lower mold 166 are used for compression molding.

  The control device 185 is used to control the heating devices 172 and 176 and the pressurizing mechanism 180.

  Next, the secondary determination step will be described in detail.

  The preform P introduced from the primary determination step is removed from the filling jig 110 and placed in the cavity of the lower mold 166 of the main molding apparatus 160.

  The main body 149 of the movable arm 146 drives the distal end frame 148 in accordance with an instruction from the control device 150. The leading end frame 148 advances to the space between the upper mold 162 and the lower mold 166 and is positioned above the preform P.

  The heating device 142 irradiates the preform P with a heat pulse in accordance with an instruction from the control device 150 to temporarily heat the preform P. The image device 144 detects infrared rays radiated from the surface of the preform P that is temporarily heated, and transmits the infrared radiation energy data to the control device 150 over time.

  The control device 150 converts the amount of infrared radiation energy transmitted from the image device 144 into a temperature, and acquires the temperature distribution on the surface of the preform P. The visualization data of the temporal change information of the temperature distribution is displayed on the display panel 154 as a color image as necessary.

  When the local temperature difference obtained from the temperature distribution at the time when the surface temperature reaches the reference temperature is equal to or less than a predetermined threshold value, it is determined that the local density difference in the preform P is good, and the movable arm 146 The main body 149 drives the distal end frame 148 in accordance with an instruction from the control device 150. When the front end frame 148 retracts from the space between the upper mold 162 and the lower mold 166 and retreats to a position where the movement toward the lower mold 166 of the upper mold 162 is not hindered, the main molding process starts.

  On the other hand, if the local temperature difference exceeds a predetermined threshold value, it is determined that a defect has occurred during removal from the filling jig 110 and / or placement in the main mold, and the main molding process starts. , Will be canceled. Even at this time, since the binder resin contained in the preform P is still in an uncured state, if the preform P is destroyed and returned to the powdery molding material M for reuse, the basic unit is improved. Can be achieved.

  Next, the main forming step will be described in detail. FIG. 10 is a schematic view for explaining the main forming step shown in FIG.

  When the secondary inspection of the preform P placed in the cavity of the lower mold 166 is completed and it is determined that the local density difference is good, the pressurizing mechanism 180 follows the instruction from the control device 185 and performs the upper inspection. The mold 162 is driven. The upper mold 162 descends toward the lower mold 166, and the upper mold 162 and the lower mold 166 are clamped. The preform P is pressed by the cavities of the upper mold 162 and the lower mold 166, and is compressed into the shape of a separator.

  On the other hand, the heating devices 172 and 176 heat the upper die 162 and the lower die 166 in accordance with instructions from the control device 185, and manage the temperatures of the upper die 162 and the lower die 166. The preform P is raised above the thermosetting temperature of the binder resin by the heat supplied by the heat transfer from the upper mold 162 and the lower mold 166, and the binder resin is thermoset.

  When the heat compression molding is completed, the pressurizing mechanism 180 opens the upper mold 162 and the lower mold 166 according to an instruction from the control device 185, and then the separator is taken out.

  When the separator is manufactured, the density quality is inspected twice based on the temperature characteristics, and the separator has a good density quality. Since the separator has a high temperature immediately after removal, the separator is cooled by a blower such as an axial fan, for example.

  As described above, the first embodiment provides an inspection method capable of 100% inspection of density quality when manufacturing a fuel cell separator, and a method of manufacturing a fuel cell separator having good density quality. It is possible to provide.

  One of the primary determination step and the secondary determination step can be omitted as appropriate.

  In order to shorten the time cycle in the main molding step, the temperatures of the heating devices 172 and 176 are adjusted, and the upper mold 162 and the lower mold 166 are preliminarily heated to an appropriate temperature lower than the thermosetting temperature of the binder resin. It is also possible.

  Further, when the heating device 117 for increasing the temperature of the molding material M and aggregating it in the preforming step is incorporated in the filling jig 110 (see FIG. 11), the preforming device 100 is simplified and the number of man-hours is reduced. It is also possible to plan.

  FIG. 12 is a cross-sectional view for explaining the method of manufacturing the separator according to the second embodiment, and shows the molding apparatus.

  The second embodiment is generally different from the first embodiment in that the configuration of the molding apparatus is changed and the secondary determination step is omitted. In addition, about the member which has the function similar to Embodiment 1, the same code | symbol is used and in order to avoid duplication, the description is abbreviate | omitted.

  The cavity of the lower mold 266 of the main molding apparatus 260 according to the second embodiment has a recess 268 in which the filling jig 210 is detachably disposed. When the filling jig 210 is disposed, one of the separators is provided. It is set to correspond to the shape of the surface.

  Therefore, the preform P formed in the preforming process and held by the filling jig 210 can be placed in the main molding apparatus 260 without being removed from the filling jig 210, and the main molding process can be started. is there. That is, unlike the first embodiment, a secondary determination step for inspecting a defect that occurs at the time of removal from the filling jig and / or placement on the main mold is not necessary.

  As described above, in the second embodiment, it is easy to omit the secondary determination process and simplify the process for manufacturing the separator. Reference numerals 262, 272, 276, 280, and 285 denote the upper mold, the heating device, the pressurizing mechanism, and the control device of the molding device 260, respectively.

  FIG. 13 is a schematic diagram for explaining the separator manufacturing method according to the third embodiment, and shows a main forming apparatus and an inspection apparatus.

  The third embodiment is generally different from the first embodiment in that the present molding apparatus also serves as a preforming apparatus. In addition, about the member which has the function similar to Embodiment 1, the same code | symbol is used and in order to avoid duplication, the description is abbreviate | omitted.

  The lower mold 366, the heating apparatus 376, and the cavity of the lower mold 366 of the main molding apparatus 360 according to the third embodiment include a heating furnace and a heating furnace base of the preforming apparatus, a heating furnace heating apparatus, and a filling jig. I'm also using it. In the third embodiment, the inspection process includes a single determination process, and only the inspection apparatus 340 that substantially matches the secondary inspection apparatus 140 according to the first embodiment is applied.

  Next, a method for manufacturing the separator according to Embodiment 3 will be described.

  In the preliminary molding process, the molding material M is discharged from the outlet 105 of the piping system connected to the storage tank (not shown) of the molding material M toward the cavity of the lower mold 366 in which the filling jig is integrated. Is done. When the supplied molding material M matches the amount required for constituting the separator, the ejection of the molding material M is stopped, and the surface of the molding material M arranged in the cavity is scraped off.

  Thereafter, the heating device 376 heats the lower mold 366 according to the instruction from the control device 385, and agglomerates the molding material M at an appropriate temperature lower than the thermosetting temperature of the binder resin, thereby forming a preform. To do.

  In the determination step (inspection step), the front end frame 348 of the movable arm 346 of the inspection device 340 advances to the space between the upper die 362 and the lower die 366 and is placed in the cavity of the lower die 366. Is positioned above.

  The preform is temporarily heated by a heat pulse emitted from a heating device 342 fixed to the tip frame 348. Infrared rays radiated from the surface of the preform are transmitted to the control device 350 via the image device 344 fixed to the tip frame 348, and the temperature distribution on the surface of the preform is calculated.

  When the local temperature difference obtained from the temperature distribution at the time when the surface temperature reaches the reference temperature is equal to or less than a predetermined threshold value, it is determined that the local density difference in the preform is good, and the leading end frame 348. However, when retreating from the space between the upper mold 362 and the lower mold 366 and retreating to a position where the movement toward the lower mold 366 of the upper mold 362 is not obstructed, the main molding process starts.

  On the other hand, when the local temperature difference exceeds a predetermined threshold, it is determined that the filling of the molding material M is inappropriate, and the density quality of the separator completed from the preform is determined to be poor, and the main molding process starts. Is canceled. At this time, since the binder resin contained in the preform is in an uncured state, the defect information on the local density difference in the preform is accurate.

  Therefore, the preform P having a good local density difference can be easily obtained by immediately feeding back to the preforming process and adjusting the filling of the molding material M. In addition, when the preform P is destroyed and returned to the powdery molding material M for reuse, the basic unit can be improved.

  In the main forming step, the upper die 362 is lowered toward the lower die 366, and the upper die 362 and the lower die 366 are clamped. The preform is pressed by the cavities of the upper mold 362 and the lower mold 366 and compressed into the shape of a separator.

  On the other hand, the heating devices 372 and 376 arranged in the upper mold 362 and the lower mold 366 heat the upper mold 362 and the lower mold 366, and the preforms are supplied by heat transfer from the upper mold 362 and the lower mold 366. The heat rises above the thermosetting temperature of the binder resin, and the binder resin is thermoset.

  When the heat compression molding is completed, the upper mold 362 and the lower mold 366 are opened, and then the separator is taken out. Since the separator has a high temperature immediately after removal, the separator is cooled by a blower such as an axial fan, for example.

  As described above, Embodiment 3 can greatly simplify the apparatus and process for manufacturing a separator. Reference numerals 349, 352, 354, and 380 indicate a main body portion of the movable arm 346 of the inspection device 340, a display device, a display panel, and a pressurizing mechanism of the main molding device 360.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims.

  For example, the binder resin is not limited to a thermosetting resin, and a thermoplastic resin such as polypropylene can also be applied. In this case, in the main molding step, it is necessary to raise the temperature of the preform to a suitable melting temperature above the softening point of the resin.

  In addition, the preform is formed by, for example, pressing and compressing at a suitable temperature lower than the thermosetting temperature of the binder resin with a preforming device similar to the present molding device, or without heating. It can also be formed only by pressure compression.

  Furthermore, it is impossible to reuse the molding material, but if necessary, an inspection process can be arranged after the main molding process, and the completed separator can be applied as an inspection object for inspecting the density quality. It is.

1 is a perspective view for explaining a fuel cell according to Embodiment 1. FIG. It is an exploded view for demonstrating the structure of the single cell of FIG. It is process drawing for demonstrating the manufacturing method of the separator shown by FIG. It is the schematic for demonstrating the preforming apparatus used in the preforming process shown by FIG. It is sectional drawing for demonstrating filling of the molding material which concerns on the preforming process shown by FIG. It is the schematic for demonstrating the primary inspection apparatus used in the primary determination process shown by FIG. It is a graph for demonstrating the inspection of the density quality based on a temperature fall characteristic, and has shown the temperature change curve. It is the schematic for demonstrating the secondary inspection apparatus used in the secondary determination process shown by FIG. It is the schematic for demonstrating the main shaping | molding apparatus which concerns on the main shaping | molding process shown by FIG. It is the schematic for demonstrating this shaping | molding process shown by FIG. 6 is a cross-sectional view for explaining a filling jig according to a modification of the first embodiment. FIG. It is sectional drawing for demonstrating the manufacturing method of the separator which concerns on Embodiment 2, and has shown this shaping | molding apparatus. It is the schematic for demonstrating the manufacturing method of the separator which concerns on Embodiment 3, and has shown this shaping | molding apparatus and the inspection apparatus.

Explanation of symbols

10. Fuel cell,
20. Stack part,
30. Single cell,
32 .. Membrane electrode assembly,
34..Electrolyte membrane,
35 .. Cathode electrode,
36 .. Anode electrode,
38. ・ Separator,
40. End plate,
50 ... Fuel gas inlet,
52 .. Fuel gas outlet,
60 .. Oxidant gas inlet,
62 .. Oxidant gas outlet,
70 .. Refrigerant inlet,
72 .. refrigerant outlet,
100 ... Pre-forming equipment,
105 .. Exit part,
110 .. Filling jig,
112 .. Convex part,
115 .. heating furnace,
116 .. Pedestal,
117 .. Heating device,
120 .. Primary inspection device,
122 .. heating device,
124 .. image device,
126 · Housing,
128 ... pedestal,
130 .. Control device,
132 .. Display device,
134 .. display panel,
140 .. Secondary inspection device,
142 .. heating device,
144 .. image device,
146 .. Movable arm,
148 .. Tip frame,
149 .. body part,
150 .. Control device,
152 .. display device,
154..Display panel,
160 .. Main forming device,
162 .. Upper mold,
163 .. Convex part,
166 ... Lower mold,
167 .. Convex part,
172, 176 ... Heating device,
180 ... Pressure mechanism
185 .. Control device,
210 .. Filling jig,
260 .. Main forming device,
262 ... Upper mold,
266 ... Lower mold,
268 .. recess,
272, 276 ... Heating device,
280 ... Pressure mechanism,
285 .. Control device,
305 ... Exit part,
340 ... Inspection equipment
342 .. Heating device,
344 ... Image device,
346 .. Movable arm,
348 .. Tip frame,
349 .. Body part,
350 .. Control device,
352 .. display device,
354 .. display panel,
360..Forming device,
362 ... Upper mold,
366 ... Lower mold,
372, 376 ... Heating device,
380 ... Pressure mechanism,
385 .. Control device,
M ・ ・ Molding materials,
P ・ ・ Preliminary molded body.

Claims (17)

When a fuel cell separator is produced from a powdery molding material containing graphite and a binder resin, based on temperature characteristics, the binder resin is inspected as a preformed body made of the molding material in an uncured state. Inspect the density quality of the object ,
The temperature characteristic comprises temporal change information of the temperature distribution of the surface of the inspection object when the temperature of the inspection object heated temporarily decreases.
In the inspection, when the local temperature difference obtained from the temporal change information exceeds a predetermined threshold value, the density quality is determined to be poor .   The inspection method according to claim 1, wherein the binder resin is a thermosetting resin. The inspection method according to claim 2 , wherein the preform is formed by increasing the temperature of the molding material disposed in a filling jig and aggregating the molding material. The inspection method according to claim 3 , wherein the preform is inspected for density quality while being held by the filling jig. After the preform is removed from the filling jig and placed in a main mold for compressing and compressing the preform at a temperature equal to or higher than the thermosetting temperature of the binder resin, the density is increased. The inspection method according to claim 3 , wherein the quality is inspected. The inspection method according to claim 1, wherein the temporary heating of the inspection object is caused by a heat pulse. The temperature characteristic, the inspection method according to any one of claims 1 to 6, characterized in that it is obtained by applying a thermography. A method for producing a separator for a fuel cell to which a powdery molding material containing graphite and a binder resin is applied,
A preforming step for forming a preform formed of the molding material in which the binder resin is in an uncured state;
Based on the temperature characteristics, it has a, and inspection process for inspecting the density quality of the inspection object consisting of the preform,
The temperature characteristic comprises temporal change information of the temperature distribution of the surface of the inspection object when the temperature of the inspection object heated temporarily decreases.
In the inspection step, when the local temperature difference obtained from the temporal change information exceeds a predetermined threshold value, it is determined that the density quality is poor . The method for manufacturing a fuel cell separator according to claim 8 , wherein the binder resin is a thermosetting resin. In the preliminary molding step, the preform, placing the molding material in the filling fixture, the temperature is raised to the molding material, by aggregating, that is formed to claim 9, wherein The manufacturing method of the separator for fuel cells of description. The filling jig has a heating means,
11. The fuel cell separator according to claim 10 , wherein, in the preforming step, a heat source for increasing the temperature of the molding material is heat transfer from the filling jig that is heated by the heating means. Method. The method for manufacturing a fuel cell separator according to claim 10 or 11 , wherein in the inspection step, the density quality of the preform is inspected while being held by the filling jig. . The preform has a main molding step for compressing and compressing the preform by a main mold at a temperature equal to or higher than the thermosetting temperature of the binder resin;
In the inspection step, the preform is removed from the filling jig, the while being disposed in the mold, in claim 10 or claim 11, characterized in that the density quality is inspected The manufacturing method of the separator for fuel cells of description. The preform has a main molding step for compressing and compressing the preform by a main mold at a temperature equal to or higher than the thermosetting temperature of the binder resin;
The main mold has a recess in which the filling jig is detachably disposed,
In the present molding process, the preform, while being held by the filling jig, to any one of claims 10 to 12, characterized in that disposed in the recess of the main forming mold The manufacturing method of the separator for fuel cells of description. The preform has a main molding step for compressing and compressing the preform by a main mold at a temperature equal to or higher than the thermosetting temperature of the binder resin;
The main mold has a cavity in which the filling jig is integrated,
In the preforming step, the preform is formed by placing the molding material in the cavity of the main mold, increasing the temperature of the molding material, and aggregating the molding material,
11. The method for manufacturing a fuel cell separator according to claim 10 , wherein in the inspection step, the density quality of the preform is inspected while being held in the cavity of the main mold. The method of manufacturing a fuel cell separator according to any one of claims 8 to 15, wherein the temporary heating of the inspection object is caused by a heat pulse. The method for producing a fuel cell separator according to any one of claims 8 to 16 , wherein, in the inspection step, the temperature characteristic is obtained by applying a thermography method.

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