Thin sheet conveying device

Abstract

To satisfactorily convey a separator as a thin plate having a surface with a plurality of recesses and a plurality of protrusions extending in a first direction and alternately provided in a second direction, using an inexpensive suction pad.SOLUTION: A thin plate conveyance device 50 has a contact part 63 that is approximately a rectangular frame in plan view and contacts a surface of the separator 3 arranged in an approximately horizontal direction, and is equipped with a suction pad 60 that generates an adhesive force by negative pressure inside the contact part 63 and a robot 55 that movably supports the suction pad 60 between a first position where the separator 3 is adsorbed and a second position where the adsorption is released. The contact part 63 has a pair of side walls extending in a first direction and the pair of side walls extending in a second direction and shorter than the first frame part. The width in the second direction of the pair of side walls extending in the first direction is wider than the width in the second direction of the recess.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a thin plate conveying device for conveying thin plates such as separators for fuel cells.

Background Art

[0002] In recent years, in order to enable more people to access affordable, reliable, sustainable, and advanced energy, technological development related to fuel cells that contribute to energy efficiency has been carried out. As a technology for conveying this type of separator for a fuel cell, conventionally, a device has been known in which an elastic member at the lower end of a suction pad having substantially the same outer peripheral shape as the separator is brought into close contact with the surface of the separator having flow path grooves to adsorb the separator (see, for example, Patent Document 1). In Patent Document 1, the surface of the elastic member is formed in a concavo-convex shape corresponding to the flow path grooves of the separator.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the device described in Patent Document 1 above, since it is necessary to form the surface of the elastic member in a concavo-convex shape corresponding to the flow path grooves of the separator, this is accompanied by an increase in cost.

Means for Solving the Problems

[0005] One aspect of the present invention is a thin sheet conveying device for conveying a thin sheet having a plurality of recesses and a plurality of protrusions on its surface that extend in a first direction and are alternately arranged in a second direction perpendicular to the first direction, comprising: a suction pad having a contact portion that is substantially rectangular in shape in plan view and contacts the surface of a thin sheet arranged substantially horizontally, and which generates an adhesive force due to negative pressure inside the contact portion; and a support portion that supports the suction pad so as to be movable between a first position for adsorbing the thin sheet and a second position for releasing the adsorption. The contact portion has a pair of first frame portions that extend in the first direction and a pair of second frame portions that are shorter than the first frame portions and extend in the second direction. If multiple recesses extend in the first direction without meandering in the second direction, The width of the first frame in the second direction is wider than the width of the recess in the second direction, or wider than the width of the convex portion in the second direction. Furthermore, if multiple recesses meander in a second direction while extending in the first direction, the width of the first frame in the second direction is wider than the meandering width of the recess in the second direction, or wider than the meandering width of the convex portion in the second direction. stomach. [Effects of the Invention]

[0006] According to the present invention, a thin plate with an uneven surface can be effectively adsorbed via an inexpensive suction pad. [Brief explanation of the drawing]

[0007] [Figure 1] A schematic perspective view showing the overall configuration of a fuel cell stack having a separator to which a thin sheet conveying device according to an embodiment of the present invention is applied. [Figure 2] A cross-sectional view along line II-II in Figure 1. [Figure 3] Figure 1 is a perspective view showing the schematic configuration of the electrode unit included in the fuel cell stack. [Figure 4] Rear view of the separator in Figure 1. [Figure 5] A schematic diagram showing the overall configuration of a thin sheet conveying device according to an embodiment of the present invention. [Figure 6A] A plan view showing the configuration of a suction pad as an example. [Figure 6B] A plan view showing the configuration of an adhesive pad as another example. [Figure 7] Figure 5 is a plan view showing the configuration of the contact portion of the suction pad. [Figure 8] Figure 7 shows an example for reference. [Figure 9] This figure shows a modified version of Figure 7. [Figure 10A] A cross-sectional view showing a modified example of the suction pad. [Figure 10B] A cross-sectional view showing other variations of the suction pad. [Modes for carrying out the invention]

[0008] Embodiments of the present invention will be described below with reference to Figures 1 to 10B. The thin sheet conveying device according to the embodiment of the present invention can be applied to various thin sheets having a plurality of recesses and protrusions alternately provided on their surface. Such thin sheets include separators for fuel cells. Below, an example of applying the thin sheet conveying device to a separator for a fuel cell will be described.

[0009] First, let's explain the configuration of the fuel cell stack, which is the main component of a fuel cell. Fuel cells can be installed in vehicles, for example, to generate electricity for vehicle propulsion. Fuel cells can also be installed in mobile vehicles other than vehicles, such as aircraft and ships, as well as robots and various industrial machines.

[0010] Figure 1 is a schematic perspective view showing the overall configuration of the fuel cell stack 100. For convenience, the three mutually orthogonal axial directions shown in the figure will be defined as the longitudinal direction, the left-right direction, and the vertical direction, and the configuration of each part will be described according to this definition. These directions are not necessarily the same as the longitudinal, left-right, and vertical directions of a vehicle. For example, the longitudinal direction in Figure 1 may be the longitudinal direction of the vehicle, the left-right direction, or the vertical direction. The longitudinal direction in Figure 1 is the stacking direction of the fuel cell stack 100, and when assembling the fuel cell stack 100, the stacking direction is aligned with the direction of gravity.

[0011] As shown in FIG. 1, the fuel cell stack 100 includes a cell stack 101 formed by stacking a plurality of power generation cells 1 in the front-rear direction, and end units 102 disposed at both front and rear ends of the cell stack 101, and has an overall substantially rectangular parallelepiped shape. The length of the cell stack 101 in the left-right direction is longer than the length in the up-down direction. In FIG. 1, for the sake of convenience, a single power generation cell 1 is shown.

[0012] The power generation cell 1 includes an electrode unit 2 (so-called UEA; Unitized Electrode Assembly) having a joined body including an electrolyte membrane and electrodes, and separators 3,3 disposed on both front and rear sides of the electrode unit 2. The electrode unit 2 is sometimes referred to as a membrane electrode structure. The electrode unit 2 and the separator 3 are alternately arranged in the front-rear direction. The separator 3 disposed on the front side of the electrode unit 2 is sometimes called the first separator, and the separator 3 disposed on the rear side is sometimes called the second separator. Although not shown, the periphery of the cell stack 101 is covered by a substantially rectangular parallelepiped case.

[0013] FIG. 2 is a cross-sectional view of a main part at the center in the left-right direction of the cell stack 101 (a cross-sectional view taken along line II-II in FIG. 1). As shown in FIG. 2, the separator 3 has a front plate 3F and a rear plate 3R which are a pair of thin metal plates with a corrugated cross-section. The front plate 3F extends in the up-down, left-right directions and has a front surface 3Fa facing forward and a rear surface 3Fb facing rearward. The rear plate 3R extends in the up-down, left-right directions and has a front surface 3Ra facing forward and a rear surface 3Rb facing rearward. The rear surface 3Fb of the front plate 3F and the front surface 3Ra of the rear plate 3R facing each other are joined together at their outer peripheries by welding or the like. Thereby, the front plate 3F and the rear plate 3R are integrally coupled to form the separator 3. A conductive material having excellent corrosion resistance is used for the separator 3, and for example, stainless steel, titanium, titanium alloy, etc. can be used.

[0014] Inside the separator 3 surrounded by the front plate 3F and the rear plate 3R, that is, between the rear surface 3Fb of the front plate 3F and the front surface 3Ra of the rear plate 3R, a cooling flow path PAw through which a cooling medium flows is formed. The power generation surface of the power generation cell 1 is cooled by the flow of the cooling medium. For example, water can be used as the cooling medium. The surfaces (front surface 3Fa and rear surface 3Rb) of the separator 3 facing the electrode unit 2 are configured to be uneven by press molding or the like so as to form a gas flow path between the separator 3 and the electrode unit 2. More specifically, the separator 3 has a pair of front and rear convex portions 31 protruding toward the electrode unit 2, and a pair of front and rear concave portions 32 configured in a concave shape and continuous with the pair of front and rear convex portions 31.

[0015] The pair of front and rear convex portions 31 abut against the front surface 2a and the rear surface 2b of the electrode unit 2. When the fuel cell stack 100 is assembled, a compressive load F is applied in the front-rear direction to the cell laminate 101, and this compressive load F is maintained after the assembly of the fuel cell stack 100 is completed. Therefore, a predetermined surface pressure due to the compressive load F acts on the electrode unit 2 in the front-rear direction via the convex portions 31.

[0016] Between the front surface 2a of the electrode unit 2 and the rear plate 3R of the separator 3 facing the front surface 2a, an anode flow path PAa through which fuel gas flows is formed by the concave portion 32. Between the rear surface 2b of the electrode unit 2 and the front plate 3F of the separator 3 facing the rear surface 2b, a cathode flow path PAc through which oxidant gas flows is formed by the concave portion 32. For example, hydrogen gas can be used as the fuel gas, and air can be used as the oxidant gas. These may also be referred to as reaction gases without distinguishing between the fuel gas and the oxidant gas.

[0017] Figure 3 is a perspective view showing the schematic configuration of electrode unit 2. As shown in Figure 3, electrode unit 2 has a substantially rectangular assembly 20 and a frame 21 that supports the assembly 20. The assembly 20 is a membrane electrode assembly (so-called MEA). As shown in the detailed view of part A in Figure 2, the assembly 20 has an electrolyte membrane 23, an anode electrode 24 provided on the front surface 231 of the electrolyte membrane 23, and a cathode electrode 25 provided on the rear surface 232 of the electrolyte membrane 23.

[0018] The electrolyte membrane 23 is, for example, a solid polymer electrolyte membrane, and a thin film of a water-containing perfluorosulfonic acid polymer can be used. Not limited to fluorine-based electrolyte membranes, hydrocarbon-based electrolyte membranes can also be used.

[0019] The anode electrode 24 is formed on the front surface 231 of the electrolyte membrane 23 and has an electrode catalyst layer 241 that serves as the reaction field for the electrode reaction, and a gas diffusion layer 242 provided in front of the electrode catalyst layer 241 that diffuses and supplies fuel gas. An intermediate layer (underlayer) may also be provided between the electrode catalyst layer 241 and the gas diffusion layer 242.

[0020] The cathode electrode 25 is formed on the rear surface 232 of the electrolyte membrane 23 and has an electrode catalyst layer 251 that serves as the reaction field for the electrode reaction, and a gas diffusion layer 252 provided on the rear surface of the electrode catalyst layer 251 that diffuses and supplies the oxidizing gas. An intermediate layer (underlayment) may also be provided between the electrode catalyst layer 251 and the gas diffusion layer 252.

[0021] At the anode electrode 24, fuel gas (hydrogen) supplied via the anode channel PAa is ionized by the action of a catalyst and moves to the cathode electrode side through the electrolyte membrane 23. The electrons generated at this time pass through an external circuit and are extracted as electrical energy. At the cathode electrode 25, oxidizing gas (oxygen) supplied via the cathode channel PAc reacts with hydrogen ions introduced from the anode electrode 24 and electrons that have moved from the anode electrode 24 to produce water. The generated water provides appropriate humidity to the electrolyte membrane 23, and excess water is discharged to the outside of the electrode unit 2 along the gas flow.

[0022] As shown in Figure 3, the frame 21 is a thin plate with a roughly rectangular shape and is made of an insulating resin or rubber. A roughly rectangular opening 21a is provided in the center of the frame 21. The joint 20 is provided so as to cover the entire opening 21a, and the peripheral edge of the joint 20 is supported by the frame 21.

[0023] To the left of the opening 21a of frame 21, three through holes 211 to 213 are opened vertically, penetrating the frame 21 in the front-to-back direction. To the right of the opening 21a, three through holes 214 to 216 are opened vertically, penetrating the frame 21 in the front-to-back direction. For convenience, the through holes 211 to 216 are shown as roughly rectangular, but their shape is not limited to this.

[0024] As shown in Figure 1, through-holes 301 to 306 are opened in the front and rear separators 3 of the electrode unit 2 at positions corresponding to the through-holes 211 to 216 of the frame 21, respectively, and penetrate the separators 3 in the front-rear direction. The through-holes 301 to 306 communicate with the through-holes 211 to 216 of the frame 21, respectively. The collection of these interconnected through-holes 211 to 216 and 301 to 306 forms flow channels PA1 to PA6 (indicated by arrows for convenience) that penetrate the cell stack 101 and extend in the front-rear direction. Flow channels PA1 to PA6 are sometimes called manifolds. Flow channels PA1 to PA6 are connected to a manifold outside the fuel cell stack 100.

[0025] The front and rear end units 102 of the cell laminate 101 have a plurality of plates 4 to 6 arranged in a stacked manner in the front-rear direction. More specifically, the end unit 102 has a terminal plate 4 arranged inward in the front-rear direction, an insulating plate 5 arranged outward in the front-rear direction of the terminal plate 4, and an end plate 6 arranged outward in the front-rear direction of the insulating plate 5.

[0026] The terminal plate 4 is a roughly rectangular plate-shaped member made of metal and has terminals for extracting the power generated by the electrochemical reaction in the cell laminate 101. The insulating plate 5 is a roughly rectangular plate-shaped member made of non-conductive resin or rubber and electrically insulates the terminal plate 4 from the end plate 6. The end plate 6 is a plate-shaped member made of metal or a high-strength resin.

[0027] In Figure 1, the end unit 102 and the cell stack 101 are shown on the toilet bowl as being the same size (same length in both the vertical and horizontal directions) when viewed from the front and rear. However, in reality, the end unit 102 is larger than the cell stack 101, and the edges of the end unit 102 (e.g., end plate 6) protrude more than the edges of the cell stack 101 in both the vertical and horizontal directions. The front and rear ends of the case (not shown) provided around the cell stack 101 are fixed to these protruding parts of the end unit 102 by bolts or the like.

[0028] The front end unit 102 is sometimes called the dry end unit, and the rear end unit 102 is sometimes called the wet end unit. The wet end unit 102 has multiple through holes 102a to 102f that penetrate the end unit 102 in the front-to-back direction at positions corresponding to through holes 211 to 216 and 301 to 306. The dry end unit 102 does not have such through holes 102a to 102f. For convenience, the through holes 102a to 102f are all shown as roughly rectangular, but the shape of the through holes 102a to 102f is not limited to this.

[0029] A fuel gas tank containing high-pressure fuel gas is connected to the through-hole 102a via an ejector, injector, etc., and fuel gas is supplied to the fuel cell stack 100 through the through-hole 102a along the solid-line flow path PA1. This fuel gas is guided through the through-holes 211 and 301 to the anode flow path PAa between the electrode unit 2 and the rear plate 3R of the separator 3. After passing through the anode flow path PAa, the fuel gas (fuel exhaust gas) is discharged through the through-hole 102f along the solid-line flow path PA6 via the through-holes 216 and 306.

[0030] A compressor for supplying oxidant gas is connected to the through-hole 102d, and the oxidant gas compressed by the compressor is supplied to the fuel cell stack 100 through the through-hole 102d along the dotted flow path PA4. This oxidant gas is guided through the through-holes 214 and 304 to the cathode flow path PAc between the electrode unit 2 and the front plate 3F of the separator 3. After passing through the cathode flow path PAc, the oxidant gas (oxidant exhaust gas) is discharged through the through-hole 102c along the dotted flow path PA3 via the through-holes 213 and 303.

[0031] A pump for supplying the cooling medium is connected to the through-hole 102e, and the cooling medium is supplied to the fuel cell stack 100 through the through-hole 102e along the dashed-dotted channel PA5. This cooling medium is then guided through the through-holes 215 and 305 to the cooling channel PAw between the front plate 3F and the rear plate 3R of the separator 3. After passing through the cooling channel PAw, the cooling medium is discharged through the through-holes 212 and 302 along the dashed-dotted channel PA2 from the through-hole 102b. The discharged cooling medium is cooled by heat exchange in the radiator and supplied back to the fuel cell stack 100 through the through-hole 102e.

[0032] The above is a general overview of the fuel cell stack 100. Hereinafter, not only the front plate 3F and the rear plate 3R joined together will be referred to as separator 3, but the front plate 3F and the rear plate 3R will also be referred to as separator 3. The thin plate conveying device according to this embodiment is used in the manufacturing process of the fuel cell stack 100. Specifically, the separators 3 stacked on a tray (for example, the front plate 3F and the rear plate 3R before they are joined together) are removed from the tray using the conveying device and conveyed to a location where a predetermined manufacturing process is carried out.

[0033] Figure 4 is a rear view (viewed from the rear) of the separator 3. Specifically, Figure 4 shows the rear surface 3Rb of the rear plate 3R, which faces the anode electrode 24 on the front surface 2a of the electrode unit 2. Point P in the figure is the midpoint of the separator 3 in both the left-right and up-down directions, and is called the center point. The left-right and up-down directions in Figure 4 correspond to the longitudinal and short-side directions of the separator 3, respectively.

[0034] In Figure 4, the region of the electrode unit 2 facing the junction 20, i.e., the region AR1 facing the power generation surface, is called the active region of the separator 3, and the region other than the active region is called the inactive region. Since the active region AR1 is located in the center of the separator 3 in the left-right direction, the active region AR1 is sometimes called the central region of the separator 3.

[0035] Within the inactive region, the left and right end regions where through holes 301 to 306 are provided are called the end region AR2 of separator 3. Within the inactive region, the left and right inner region of the end region AR2 is called the connection region AR3 of separator 3. The connection region AR3 is located between the active region AR1 and the left and right end regions AR2.

[0036] In the active region AR1 of the separator 3, although some parts are not shown in the illustration, multiple protrusions 31 are provided at equal intervals in the vertical direction and extending backward across almost the entire area. Each of the multiple protrusions 31 extends in the left-right direction, and recesses 32 are provided between adjacent protrusions 31, 31 in the vertical direction. An anode channel PAa (Figure 2) is formed between the multiple recesses 32 and the front surface 2a of the joint 20.

[0037] More specifically, as shown in the enlarged view of section A in Figure 4, the convex portion 31 and the concave portion 32 extend horizontally while meandering vertically. Therefore, the vertical length of the convex portion 31, i.e., the length from the lower end point P1 to the upper end point P2 of the convex portion 31 (referred to as the convex portion meander width) Wa, is longer than the vertical length of the convex portion 31 if it were not meandering (referred to as the convex portion width). Similarly, the vertical length of the concave portion 32, i.e., the length from the lower end point P3 to the upper end point P4 of the concave portion 32 (referred to as the flow path meander width) Wb, is longer than the vertical length of the concave portion 32 if it were not meandering (referred to as the flow path width).

[0038] The meandering width of the convex portion Wa and the meandering width of the flow path Wb are equal to each other (Wa = Wb). The meandering width of the convex portion Wa may be longer than the meandering width of the flow path Wb (Wa > Wb), and the meandering width of the flow path Wb may be longer than the meandering width of the convex portion Wa (Wb > Wa). As the concave portion 32 meanders in the left-right direction, the area of ​​the anode flow path PAa increases, and the flow velocity of the fuel gas flowing through the anode flow path PAa decreases. This promotes the reaction caused by the flow of fuel gas.

[0039] The rear surface 3Rb of the separator 3 (rear plate 3R) is provided with multiple bead portions for sealing, i.e., metal bead seals, that protrude rearward toward the frame 21. The multiple bead portions include an outer bead portion 331, an inner bead portion 332, and an end bead portion 333. The connection area AR3 of the separator 3 is provided with multiple substantially cylindrical embossed portions 341, 342 that protrude in the front-rear direction.

[0040] The protrusions 31 and recesses 32, as well as the metal bead seal, are formed by press-forming the rear plate 3R. Although not shown in the illustration, the protrusions 31 and recesses 32, as well as the metal bead seal, are similarly formed on the front plate 3F by press-forming the front plate 3F.

[0041] Figure 5 is a schematic diagram showing the overall configuration of the thin sheet conveying device 50 according to this embodiment. As shown in Figure 5, the thin sheet conveying device 50 includes an industrial robot 55 having articulated arms 51 and 52 and a hand 53 provided at the tip of the arm 52, and a suction pad 60 supported by the hand 53.

[0042] Arms 51 and 52 are rotatably connected via a pivot shaft 55a, and arm 52 and hand 53 are rotatably connected via a pivot shaft 55b. Note that the configuration of the robot 55 (number of arms, etc.) is not limited to that shown in the figure. Arms 51, 52 and hand 53 rotate by the drive of actuators 54, such as servo motors, provided on pivot shafts 55a and 55b, thereby changing the position and orientation of hand 53. The actuators 54 are controlled by an ECU 56. The ECU 56 is an electronic control unit comprising a computer having a CPU, ROM, RAM, and other peripheral circuits.

[0043] The suction pad 60 has a rod portion 61 that extends vertically below the hand 53, and a pad portion provided at the lower end of the rod portion 61. The upper end of the rod portion 61 is supported by the hand 53. A support member may be interposed between the hand 53 and the rod portion 61, so that the rod portion 61 is supported from the hand 53 via the support member. The support member may also be provided so that the suction pad 60 can move up and down relative to the hand 53 via a spring.

[0044] The pad portion 62 has an open lower end surface. The pad portion 62 has a cavity inside, and the sides of the pad portion 62 are tapered so that the area of ​​the cavity in the horizontal plane gradually increases from top to bottom. A roughly rectangular frame-shaped contact portion 63 is provided at the lower end of the pad portion 62. The contact portion 63 is made of an elastic material such as rubber. The lower end surface of the contact portion 63 is made of a flat surface, and this lower end surface contacts the upper surface of the separator 3.

[0045] The rod portion 61 of the suction pad 60 is cylindrical, and its internal passage is connected to a vacuum generator 65. By generating negative pressure (vacuum pressure) inside the pad portion 62 via the vacuum generator 65, the separator 3 can be attracted to the suction pad 60. The operation of the vacuum generator 65 is controlled by the ECU 56.

[0046] The hand 53 moves up and down above the tray 200, which has an open top. The tray 200 stores the separators 3 (front plate 3F, rear plate 3R) in a stacked state. The tray 200 is set to the first position. The hand 53 moves from the first position to the second position with the separators 3 held in place by the suction pad 60, based on a command from the ECU 56. This transports the separators 3 from the first position to the second position.

[0047] At the second position, a mounting table 201 is provided for performing predetermined processing on the separator 3. When the separator 3 moves above the mounting table 201, the operation of the vacuum generator 65 is deactivated by a command from the ECU 56, thereby placing the separator 3 on the mounting table 201. Subsequently, the hand 53 returns to the first position by a command from the ECU 56, and the transport of the separator 3 from the first position to the second position is repeated.

[0048] When the suction pad 60 adsorbs the separator 3, if the contact portion 63 contacts a flat surface on the separator 3 that is free of irregularities, the suction force of the suction pad 60 due to negative pressure can be increased, making it easier to adsorb the separator 3. However, as shown in Figure 4, the surface of the separator 3 is formed with irregularities in all of the active region AR1, end region AR2, and connecting region AR3, and there is no flat surface on which the suction pad 60 can contact.

[0049] If the separator 3 were configured to have a flat surface that the suction pad 60 can contact, the separator 3 would become larger, leading to increased costs. Also, if the active region AR1 were narrowed to provide a flat surface that the suction pad 60 can contact, it would lead to a decrease in the performance of the fuel cell. Therefore, in this embodiment, the separator 3 is adsorbed by bringing the contact portion 63 of the suction pad 60 into contact with the active region AR1 of the separator 3, which has regularly arranged convex portions 31 and concave portions 32.

[0050] The configuration of the suction pad 60 (especially the contact portion 63) will now be described. Figures 6A and 6B are plan views showing the configurations of the contact portions 63A and 63B included in a thin plate conveying device as reference examples, respectively. Figures 6A and 6B show the state in which the contact portion 63A is in contact with the active region AR1 of the surface of the separator 3 (for example, the rear surface 3Rb of the rear plate 3R). At this time, the surface of the separator 3 is facing upward, and the longitudinal direction of the separator 3 (left-right direction in Figure 4) is shown as the X1-X2 direction, and the short direction is shown as the Y1-Y2 direction. Figures 6A and 6B show the entire active region AR1 of the separator 3, and the illustration of areas other than the active region AR1 is omitted.

[0051] In the example shown in Figure 6A, the thin plate conveying device has four suction pads 60A. The suction pads 60A are roughly ring-shaped in plan view. The contact portions 63A of the four suction pads 60A are arranged at four locations around the center point P within the active region AR1 of the separator 3, and their lower end surfaces 63A1 are in contact with the surface of the separator 3. As shown in the enlarged view of section A in Figure 6A, the lower end surfaces 63A1 of the contact portions 63A1 face the convex portion 31 and concave portion 32 on the surface of the separator 3.

[0052] In this state, when the vacuum generator 65 is activated, air flows into the inner space SPa of the contact portion 63A through the gap between the lower end surface 63A1 of the suction pad 60A and the recess 32, as indicated by the arrow. In Figure 6A, since the contact portion 63A is substantially ring-shaped, the area of ​​the lower end surface 63A1 facing the convex portion 31 and the area of ​​the lower end surface 63A1 facing the recess 32 are approximately equal. As a result, the amount of air flowing into the inner space SPa of the contact portion 63A through the recess 32 increases, making it difficult to create a sufficient negative pressure in the inner space SPa of the contact portion 63A. Consequently, in order to obtain sufficient suction force on the separator 3, it becomes necessary to increase the capacity of the vacuum generator 65, which leads to increased costs.

[0053] In the example shown in Figure 6B, similar to Figure 6A, the thin plate conveying device has four suction pads 60B. The suction pads 60B have a roughly square frame shape in plan view. The contact portions 63B of the four suction pads 60B are arranged at four locations around the center point P within the active region AR1 of the separator 3, and their lower end surfaces 63B1 are in contact with the surface of the separator 3. As shown in the enlarged view of section B in Figure 6B, the lower end surfaces 63B1 of the contact portions 63B face the convex portion 31 and concave portion 32 on the surface of the separator 3.

[0054] In Figure 6B, of the four side walls 63B11, 63B12, 63B13, and 63B14 of the contact portion 63B, the lower end surface 63B1 of one side wall 63B11 extending in the X1-X2 direction abuts against the convex portion 31 of the separator 3, while the lower end surface 63B1 of the other side wall 63B13 faces the concave portion 32. Also, the lower end surfaces 63B1 of the pair of side walls 63B12 and 63B14 extending in the Y1-Y2 direction alternately face the convex portion 31 and the concave portion 32. As a result, more than half of the area of ​​the lower end surface 63B1 of the suction pad 60B faces the concave portion 32. Therefore, when the vacuum generator 65 is activated, a large amount of air flows into the inner space SPb of the contact portion 63B through the gap between the lower end surface 63B1 and the recess 32, as indicated by the arrow, making it difficult to create a sufficient negative pressure in the inner space SPb of the contact portion 63B. As a result, in order to obtain sufficient adsorption force on the separator 3, it becomes necessary to increase the capacity of the vacuum generator 65, which leads to increased costs.

[0055] Figure 7 is a plan view showing the configuration of the contact portion 63 of the suction pad 60 included in the thin sheet conveying device 50 according to this embodiment. As shown in Figure 7, the thin sheet conveying device 50 has a single suction pad 60. The contact portion 63 of the suction pad 60 has a substantially rectangular frame shape in plan view. The suction pad 60 is positioned such that the center of the contact portion 63 is located at the center point P of the separator 3.

[0056] The contact portion 63 has a pair of side walls 631, 633 extending in the X1-X2 direction and a pair of side walls 632, 634 extending in the Y1-Y2 direction. Side walls 631, 633 are longer than side walls 632, 634. For example, the length of side walls 631, 633 is more than twice the length of side walls 632, 634. The width W of the contact portion 63 is constant around its entire circumference. That is, the length (width W) of side walls 631, 633 in the Y1-Y2 direction and the length (width W) of side walls 632, 634 in the X1-X2 direction are equal to each other. As shown in the enlarged view of section A in Figure 7, the width W of the contact portion 63 is set to be wider than the meandering width Wb of the flow path.

[0057] When the robot 55 transports the separator 3 from the first position to the second position, the ECU 56 first outputs a control signal to the actuator 54 so that the center of the suction pad 60 coincides with the center point P of the separator 3 at the first position, and drives the robot 55. When the suction pad 60 moves to the first position, the lower end surfaces 630 of the side walls 631 and 632 come into contact with the upper surface of the convex portion 31 of the separator 3 along its entire length in the X1-X2 direction. More specifically, as shown in the enlarged view of section A in Figure 7, the lower end surfaces 630 of the side walls 631 and 633 come into contact with the upper surface of the pair of convex portions 31 that sandwich the recess 32.

[0058] This seals the lower end surface 630 of the side walls 631 and 633. Therefore, when the vacuum generator 65 is activated and the suction pad 60 starts to pick up the separator 3, it is possible to prevent air from flowing from the outer space SP2 to the inner space SP1 of the contact portion 63 through the gap between the lower end surface 630 and the recess 32. As a result, the robot 55 can transport the separator 3 from the first position to the second position while maintaining a high suction force by the suction pad 60. When the separator 3 is transported to the second position, the operation of the vacuum generator 65 is released by a command from the ECU 56. As a result, the separator 3 is placed on the mounting table 201 as shown in Figure 5.

[0059] Figure 8 is a reference example of Figure 7, showing a case where the width W of the contact portion 63 is narrower than the meandering width Wb of the flow path. In the example shown in Figure 8, a portion of the recess 32 is exposed in a plan view, not covered by the lower end surface 630 of the contact portion 63. As a result, the inner space SP1 and the outer space SP2 of the contact portion 63 are in communication through the recess 32. Consequently, as indicated by the arrows in Figure 8, air flows into the inner space SP0 of the contact portion 63 beyond the side wall 633.

[0060] On the other hand, in this embodiment, the width W of the side walls 631 and 633 is set to be wider than the meandering width Wb of the flow path. Therefore, the lower end surfaces 630 of the side walls 631 and 633 function as a sealing portion. There is a gap between the lower end surfaces 630 of the side walls 632 and 634 and the recess 32, but the side walls 631 and 633 are longer than the side walls 632 and 634. Therefore, the amount of air flowing from the outer space SP2 to the inner space SP1 of the contact portion 63 beyond the side walls 632 and 634 is small, and sufficient negative pressure can be generated in the inner space SP1 of the contact portion 63. As a result, the suction force of the suction pad 60 due to the negative pressure increases, and the separator 3 can be easily adsorbed.

[0061] The pad portion 62 of the suction pad 60 is made of resin or rubber. Therefore, as the number of uses of the thin plate conveying device 50 increases, the pad portion 62 (contact portion 63) that contacts the separator 3 wears down, and the pad portion 62 needs to be replaced. In this case, as shown in the example in Figures 6A and 6B, if there are four suction pads 60A and 60B, the replacement work of the pad portion takes a lot of time. In this embodiment, however, since a single suction pad 60 is used, the time required for replacement work can be shortened.

[0062] This embodiment can provide the following effects and advantages. (1) The thin sheet conveying device 50 is configured to convey a separator 3 having a plurality of recesses 32 and a plurality of protrusions 31 on its surface that extend in the X1-X2 direction and are alternately provided in the Y1-Y2 direction (Figures 4 and 5). The thin sheet conveying device 50 has a contact portion 63 that is roughly rectangular in shape in plan view and contacts the surface of the separator 3 which is arranged in a roughly horizontal direction, and includes a suction pad 60 that generates an suction force due to negative pressure in the inner space SP1 of the contact portion 63, and a robot 55 that supports the suction pad 60 so that it can move between a first position in which the separator 3 is attracted and a second position in which the attraction is released (Figures 5 and 7). The contact portion 63 has a pair of side walls 631 and 633 that extend in the X1-X2 direction, and a pair of side walls 632 and 634 that are shorter than the side walls 631 and 633 that extend in the Y1-Y22 direction (Figure 7). The width W of the side walls 631 and 633 in the Y1-Y2 direction is wider than the width Wb of the recess 32 in the Y1-Y2 direction (flow channel meander width) (Figure 7).

[0063] With this configuration, the gap between the recess 32 of the separator 3 and the side walls 631, 633 of the suction pad 60 is sealed along the entire length of the side walls 631, 633, and the lower ends of the side walls 631, 633 function as a sealing portion. In this case, the side walls 631, 632 extending in the X1-X2 direction are longer than the side walls 632, 634 extending in the Y1-Y2 direction, so more than half of the area of ​​the lower end surface 630 of the contact portion 63 functions as a sealing portion. This creates a negative pressure state in the inner space SP0 of the suction pad 60, generating a high suction force of the suction pad 60 on the separator 3. As a result, there is no need to configure the lower end surface of the contact portion 63 to be uneven, and the separator 3 can be effectively adsorbed using an inexpensive suction pad 60. Furthermore, there is no need to use a large-capacity vacuum generator 65, which can suppress the cost increase of the thin plate conveying device 50. In order to close the gap between the suction pad 60 and the recess 32, it is conceivable to construct the contact portion 63 of the suction pad 60 with a flexible material. However, with this configuration, if the separator 3 is warped or bent, it becomes difficult to accurately position the separator 3. In this embodiment, however, even if the separator 3 is warped or bent, the separator 3 can be accurately positioned.

[0064] (2) The robot 55 supports the suction pad 60 in the first position such that the lower end surfaces of the side walls 631 and 633 each abut against a pair of protrusions 31 that sandwich the recess 32 (Figure 7). As a result, the upper part of the recess 32 extending in the X1-X2 direction is covered by the lower end surfaces 630 of the side walls 631 and 633, so that the airflow into the inner space SP1 through the recess 32 can be reliably blocked.

[0065] (3) The multiple recesses 32 meander in the Y1-Y2 direction and extend in the X1-X2 direction (Figure 7). When the recesses 32 meander, the width Wb of the flow path widens, but in this embodiment, the suction pad 60 is configured such that the width W of the side walls 631, 632 of the contact portion 63 is wider than this meandering flow path width Wb (Figure 7). This ensures a reliable seal between the lower end surface 630 of the side walls 631, 633 and the separator 3.

[0066] (4) The thin sheet conveying device 50 is applied to the conveying of a separator 3 for a fuel cell, in which a flow channel groove (anode flow channel PAa, cathode flow channel PAc) through which the reaction gas flows is formed by a plurality of recesses 32 (Figure 4). In such a separator 3, the recesses 32 and protrusions 31 are regularly arranged in the central active region AR1, making it suitable for application of the thin sheet conveying device 50.

[0067] (5) The thin sheet conveying device 50 has a single suction pad 60 positioned in the center of the separator 3 (Figure 7). This means that when replacing the pad section 62, only a single pad section 62 needs to be replaced, so the replacement work can be done in a short time.

[0068] The above embodiment can be modified into various forms. Several modifications will be described below. In the above embodiment, the thin plate conveying device 50 has a single suction pad 60, but it may have a plurality of suction pads 60. Figure 9 shows one example. In Figure 9, there is a pair of suction pads 60 of the same shape. The pair of suction pads 60 are arranged symmetrically in the Y1-Y2 direction with respect to the center point P. The width W and length in the X1-X2 direction of the contact portion 63 in Figure 9 are the same as the width W and length in the X1-X2 direction of the contact portion 63 in Figure 7. On the other hand, the length in the Y1-Y2 direction of the single contact portion 63 in Figure 9 is half the length in the Y1-Y2 direction of the contact portion 63 in Figure 7.

[0069] As shown in the configuration of Figure 9, the gap between the recess 32 of the separator 3 and the side walls 631, 633 of the suction pad 60 is sealed along the entire length of the side walls 631, 633, and the lower ends of the side walls 631, 633 function as a sealing portion. This generates sufficient negative pressure in the inner space SP1 of the contact portion 63 of the recess 32, allowing the separator 3 to be easily adsorbed by the pair of suction pads 60. Furthermore, since the suction pads 60 are positioned further away from the center point P in the Y1-Y2 direction than in Figure 7, the separator 3 can be stably supported over a wide area.

[0070] To prevent airflow into the inner space SP1 through the gap between the side walls 632, 634 of the suction pad 60 and the recess 32, a sealing portion may be provided on the side walls 632, 634. Figures 10A and 10B are vertical cross-sectional views of the main part of the suction pad 60, showing an example of this. In Figure 10A, a foam member 71, such as shrinkable foamed urethane, is attached to the outer side surface of the side walls 632, 634 in the X1-X2 direction. The foam member 71 protrudes below the lower end surface of the side walls 632, 634. As a result, a part of the foam member 71 is pushed into the recess 32, and the gap between the lower end surface of the side walls 632, 634 and the recess 32 can be sealed.

[0071] In Figure 10B, a flexible resin film member 72 is attached to the outer side surface of the side walls 632 and 634 in the X1-X2 direction. The film member 72 protrudes below the lower end surface of the side walls 632 and 634. Cuts are provided at equal intervals in the Y1-Y2 direction and extending vertically at the lower end of the film member 72 (the portion that protrudes below the lower end surface of the side walls 632 and 634), so that the film member 72 is configured in a pleated shape. As a result, a part of the film member 72 is pushed into the recess 32, which closes the gap between the lower end surface of the side walls 632 and 634 and the recess 32.

[0072] In the above embodiment, the width W of the side walls 631, 633 of the suction pad 60 is set wider than the width (flow path meandering width) Wb of the recess 32, but it may also be set wider than the width (protrusion meandering width) Wa of the protrusion 31. This allows the lower end surfaces 630 of the side walls 631, 633 to contact the upper surface of the protrusion 31 of the separator 3 located at the first position over the entire length of the side walls 631, 633 in the X1-X2 direction. As a result, it is possible to prevent air from flowing into the inner space SP1 of the suction pad 60 through the gap between the side walls 631, 633 and the recess 32.

[0073] The meandering width Wb of the channel may be wider than the meandering width Wa of the convex section. In this case, by setting the width W of the side walls 631, 633 to be wider than the meandering width Wa of the convex section, the width W of the side walls 631, 633 may be shorter than the meandering width Wb of the channel, and the width W of the side walls 631, 633 can be minimized. The meandering width Wa of the convex section may be wider than the meandering width Wb of the channel. In this case, by setting the width W of the side walls 631, 633 to be wider than the meandering width Wb of the channel, the width W of the side walls 631, 633 may be shorter than the meandering width Wa of the convex section, and the width W of the side walls 631, 633 can be minimized.

[0074] In the above embodiment, a separator 3 of a fuel cell stack 100 having a plurality of alternating recesses 32 and protrusions 31 that extend in the X1-X2 direction (first direction) and are alternately arranged in the Y1-Y2 direction (second direction) was applied to the thin sheet conveying device 50. However, the thin sheet conveying device of the present invention can be similarly applied to other thin sheets having such recesses and protrusions. In the above embodiment, the plurality of recesses 32 on the surface of the separator 3 were configured to meander in the Y1-Y2 direction while extending in the X1-X2 direction, but the recesses do not need to meander.

[0075] In the above embodiment, the suction pad 60 is supported by a robot 55 having a multi-joint arm so that it can move from a first position to a second position, but the configuration of the support part is not limited to that described above. In the first position, the separator 3 is stored in the tray 200, and in the second position, the separator 3 is placed on the mounting table 201, but the first and second positions may be other positions. In the above embodiment, with respect to the width W of the side walls 631 to 634 of the contact portion 63, the width W of the pair of side walls 631, 633 (a pair of first frame portions) extending in the first direction and the width W of the pair of side walls 632, 634 extending in the second direction are set to the same value, but the width of the pair of first frame portions and the width of the pair of second frame portions may be set to different values.

[0076] The above description is merely an example, and the present invention is not limited by the embodiments and modifications described above, as long as the features of the present invention are not impaired. It is also possible to arbitrarily combine one or more of the above embodiments and modifications, and to combine modifications with each other.

[0077] 3 Separator, 31 Protrusion, 32 Recess, 50 Thin plate conveying device, 55 Robot, 100 Fuel cell stack, 60 Suction pad, 63 Contact part, 631-634 Side wall, Wa Protrusion meandering width, Wb Flow path meandering width

Claims

1. A thin sheet conveying device for conveying a thin sheet having a plurality of recesses and a plurality of protrusions on its surface that extend in a first direction and are alternately arranged in a second direction perpendicular to the first direction, A suction pad having a contact portion that is roughly rectangular in shape in plan view and contacts the surface of the thin plate arranged in a roughly horizontal direction, and generating an adsorption force due to negative pressure inside the contact portion, The system includes a support portion that movably supports the suction pad between a first position for adsorbing the thin plate and a second position for releasing the adsorption, The contact portion has a pair of first frame portions extending in the first direction and a pair of second frame portions that are shorter than the first frame portions and extend in the second direction. A thin plate conveying device characterized in that, when the plurality of recesses extend in the first direction without meandering in the second direction, the width of the first frame portion in the second direction is wider than the width of the recesses in the second direction, or wider than the width of the protrusions in the second direction, and when the plurality of recesses extend in the first direction while meandering in the second direction, the width of the first frame portion in the second direction is wider than the meandering width of the flow path of the recesses in the second direction, or wider than the meandering width of the protrusions in the second direction.

2. In the thin plate conveying device according to claim 1, The width of the first frame portion in the second direction is wider than the width of the recess in the second direction or the meandering width of the flow path. The thin plate conveying device is characterized in that the support portion supports the suction pad such that the first frame portion abuts against a pair of protrusions that sandwich the recess at the first position.

3. In the thin plate conveying device according to claim 1, The width of the first frame portion in the second direction is wider than the width of the protrusion portion in the second direction or the meandering width of the flow path. The thin plate conveying device is characterized in that the support portion supports the suction pad such that the first frame portion is positioned across a pair of recesses that sandwich the convex portion at the first position.

4. In the thin plate conveying device according to any one of claims 1 to 3, The thin plate conveying device is characterized in that the thin plate is a separator for a fuel cell in which a flow channel groove for reaction gas is formed by the plurality of recesses.

5. In the thin plate conveying device according to Claim 4, The thin plate conveying device is characterized in that the suction pad is a single suction pad positioned in the center of the separator.

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