Thin plate conveyance 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 transport device for transporting thin plates such as separators for fuel cells. [Background technology]

[0002] In recent years, technological developments related to fuel cells that contribute to energy efficiency have been underway to ensure that more people have access to affordable, reliable, sustainable, and advanced energy. A conventional technology for transporting separators for this type of fuel cell is a device that adsorbs the separator by bringing an elastic member at the lower end of a suction pad, which has a shape roughly the same as the outer periphery of the separator, into close contact with the surface of the separator, which has flow channel grooves (see, for example, Patent Document 1). In Patent Document 1, the surface of the elastic member is formed with an uneven shape corresponding to the flow channel grooves of the separator. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-173058 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the device described in Patent Document 1, the surface of the elastic member needs to be formed unevenly to correspond to the flow channel grooves of the separator, which increases costs. [Means for solving the problem]

[0005] One aspect of the present invention is a thin plate conveying device for conveying a thin plate having, on its surface, a plurality of recesses and a plurality of protrusions extending in a first direction and alternately arranged in a second direction perpendicular to the first direction. The device includes: a suction pad having a contact portion having a generally rectangular frame shape in plan view that contacts the surface of the thin plate arranged in a generally horizontal direction and that generates a suction force by negative pressure inside the contact portion; and a support portion that movably supports the suction pad between a first position where the thin plate is attracted to the contact portion and a second position where the suction force is released. The contact portion has a pair of first frame portions extending in the first direction and a pair of second frame portions extending in the second direction and shorter than the first frame portions. The width of the first frame portions 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. [Effects of the Invention]

[0006] According to the present invention, a thin plate having an uneven surface can be satisfactorily sucked by an inexpensive suction pad. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a perspective view showing a schematic overall configuration of a fuel cell stack having separators to which a thin plate transport device according to an embodiment of the present invention is applied; [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 2 is a perspective view showing a schematic configuration of an electrode unit included in the fuel cell stack of FIG. [Figure 4] FIG. 2 is a rear view of the separator of FIG. 1. [Figure 5] 1 is a diagram schematically illustrating the overall configuration of a thin plate conveying device according to an embodiment of the present invention. [Figure 6A] FIG. 10 is a plan view showing the configuration of a suction pad as a reference example. [Figure 6B] FIG. 10 is a plan view showing the configuration of a suction pad as another reference example. [Figure 7] 6 is a plan view showing the configuration of the contact portion of the suction pad of FIG. 5. [Figure 8] FIG. 8 is a diagram showing a reference example of FIG. 7. [Figure 9] FIG. 8 is a diagram showing a modification of FIG. 7. [Figure 10A] FIG. 10 is a cross-sectional view showing a modified example of the suction pad. [Figure 10B] FIG. 10 is a cross-sectional view showing another modified example of the suction pad. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of the present invention will be described with reference to Figs. 1 to 10B. A thin plate conveying device according to an embodiment of the present invention can be applied to various thin plates having a plurality of alternating concave and convex portions on the surface. Such thin plates include separators for fuel cells. Below, an example will be described in which the thin plate conveying device is applied to separators for fuel cells.

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

[0010] FIG. 1 is a perspective view showing a schematic view of the overall configuration of a fuel cell stack 100. For convenience, the three mutually orthogonal axial directions shown in the figure are defined as the front-rear direction, the left-right direction, and the up-down direction, and the configuration of each part will be described in accordance with these definitions. These directions are not necessarily the same as the front-rear direction, the left-right direction, and the up-down direction of a vehicle. For example, the front-rear direction in FIG. 1 may be the front-rear direction, the left-right direction, or the up-down direction of a vehicle. The front-rear direction in FIG. 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 has a cell stack 101 formed by stacking a plurality of power-generating cells 1 in the front-to-rear direction, and end units 102 arranged at both front and rear ends of the cell stack 101, and has a generally rectangular parallelepiped shape as a whole. The length of the cell stack 101 in the left-to-right direction is longer than the length in the up-to-down direction. For convenience, only a single power-generating cell 1 is shown in Fig. 1.

[0012] The power-generating cell 1 has an electrode unit 2 (so-called UEA: Unitized Electrode Assembly) having an assembly including an electrolyte membrane and electrodes, and separators 3, 3 arranged on both the front and rear sides of the electrode unit 2. The electrode unit 2 is sometimes called a membrane electrode structure. The electrode units 2 and the separators 3 are arranged alternately in the front-to-rear direction. The separator 3 arranged on the front side of the electrode unit 2 is sometimes called the first separator, and the separator 3 arranged on the rear side is sometimes called the second separator. Although not shown in the figure, the cell stack 101 is covered by a roughly rectangular parallelepiped case.

[0013] FIG. 2 is a cross-sectional view (a cross-sectional view taken along line II-II in FIG. 1) of a main portion of the cell stack 101 in the left-right direction. As shown in FIG. 2, the separator 3 has a front plate 3F and a rear plate 3R, which are a pair of front and rear metal thin plates with a corrugated cross section. The front plate 3F extends vertically and horizontally and has a front surface 3Fa facing forward and a rear surface 3Fb facing rearward. The rear plate 3R extends vertically and horizontally 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, which face each other, are joined at their outer peripheries by welding or the like. This integrally joins the front plate 3F and the rear plate 3R to form the separator 3. The separator 3 is made of a conductive material with excellent corrosion resistance, such as stainless steel, titanium, or a titanium alloy.

[0014] A cooling flow path PAw through which a coolant flows is formed 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. The flow of the coolant cools the power generation surface of the power generation cell 1. Water, for example, can be used as the coolant. The surface of the separator 3 facing the electrode unit 2 (the front surface 3Fa and the rear surface 3Rb) is formed unevenly by press molding or the like 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 protrusions 31 that protrude toward the electrode unit 2, and a pair of front and rear recesses 32 that are connected to the pair of front and rear protrusions 31 and are formed in a concave shape.

[0015] The pair of front and rear protrusions 31 abut against the front surface 2a and rear surface 2b of the electrode unit 2. A compressive load F is applied to the cell stack 101 in the front-to-rear direction during assembly of the fuel cell stack 100, and this compressive load F is maintained after assembly of the fuel cell stack 100 is complete. As a result, a predetermined surface pressure due to the compressive load F acts on the electrode unit 2 in the front-to-rear direction via the protrusions 31.

[0016] Between the front surface 2a of the electrode unit 2 and the rear plate 3R of the separator 3 facing this front surface 2a, an anode flow path PAa through which a fuel gas flows is formed by a recess 32. Between the rear surface 2b of the electrode unit 2 and the front plate 3F of the separator 3 facing this rear surface 2b, a cathode flow path PAc through which an oxidizer gas flows is formed by a recess 32. For example, hydrogen gas can be used as the fuel gas, and for example, air can be used as the oxidizer gas. Sometimes, the fuel gas and the oxidizer gas are referred to as reactant gases without distinction between them.

[0017] Fig. 3 is a perspective view showing a schematic configuration of the electrode unit 2. As shown in Fig. 3, the 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; Membrane Electrode Assembly). As shown in the detailed view of part A in Fig. 2, the assembly 20 has an electrolyte membrane 23, an anode electrode 24 provided on a front surface 231 of the electrolyte membrane 23, and a cathode electrode 25 provided on a 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 perfluorosulfonic acid polymer containing water can be used. The electrolyte membrane 23 is not limited to a fluorine-based electrolyte membrane, and a hydrocarbon-based electrolyte membrane can also be used.

[0019] The anode 24 is formed on the front surface 231 of the electrolyte membrane 23 and has an electrode catalyst layer 241 that serves as a reaction field for an electrode reaction, and a gas diffusion layer 242 that is provided in front of the electrode catalyst layer 241 and that diffuses and supplies a fuel gas. An intermediate layer (base layer) can 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 a reaction field for an electrode reaction, and a gas diffusion layer 252 that is provided on the rear surface of the electrode catalyst layer 251 and that diffuses and supplies an oxidant gas. An intermediate layer (base layer) may be provided between the electrode catalyst layer 251 and the gas diffusion layer 252.

[0021] At the anode electrode 24, the fuel gas (hydrogen) supplied via the anode flow path PAa is ionized by the action of the catalyst and moves through the electrolyte membrane 23 toward the cathode electrode. The electrons generated at this time pass through an external circuit and are extracted as electrical energy. At the cathode electrode 25, the oxidant gas (oxygen) supplied via the cathode flow path PAc reacts with the hydrogen ions introduced from the anode electrode 24 and the electrons transferred from the anode electrode 24, producing water. The produced water provides an 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] 3, the frame 21 is a thin plate having a substantially rectangular shape and is made of insulating resin, rubber, or the like. A substantially rectangular opening 21a is provided in the center of the frame 21. The joining body 20 is provided so as to cover the entire opening 21a, and the peripheral edge of the joining body 20 is supported by the frame 21.

[0023] Three through holes 211 to 213 are aligned vertically and penetrate the frame 21 in the front-to-rear direction on the left side of the opening 21a of the frame 21. Three through holes 214 to 216 are aligned vertically and penetrate the frame 21 in the front-to-rear direction on the right side of the opening 21a. For convenience, the through holes 211 to 216 are shown as being substantially rectangular, but the shape of the through holes 211 to 216 is not limited to this.

[0024] As shown in FIG. 1, the separators 3 on the front and rear of the electrode unit 2 are provided with through holes 301 to 306, respectively, which penetrate the separators 3 in the front-rear direction at positions corresponding to the through holes 211 to 216 of the frame 21. The through holes 301 to 306 are connected to the through holes 211 to 216 of the frame 21, respectively. A collection of these mutually communicating through holes 211 to 216 and 301 to 306 form flow paths PA1 to PA6 (indicated by arrows for convenience) which penetrate the cell stack 101 and extend in the front-rear direction. The flow paths PA1 to PA6 are sometimes called manifolds. The flow paths PA1 to PA6 are connected to a manifold external to the fuel cell stack 100.

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

[0026] The terminal plate 4 is a generally rectangular metal plate-like member and has a terminal portion for extracting the power generated by the electrochemical reaction in the cell stack 101. The insulating plate 5 is a generally rectangular non-conductive resin or rubber plate-like member that electrically insulates the terminal plate 4 from the end plate 6. The end plate 6 is a metal or high-strength resin plate-like member.

[0027] In Figure 1, the end unit 102 and the cell stack 101 are shown on the toilet as being the same size (same vertical length and same horizontal length) when viewed from the front and back. 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 in the vertical and horizontal directions beyond the edges of the cell stack 101. The front and rear ends of a case (not shown) provided around the cell stack 101 are fixed to the protruding portions of the end unit 102 with bolts or the like.

[0028] The front end unit 102 may be referred to as the dry-side end unit, and the rear end unit 102 as the wet-side end unit. The wet-side end unit 102 has a plurality of through holes 102a-102f that penetrate the end unit 102 in the front-to-rear direction, at positions corresponding to the through holes 211-216 and 301-306. Note that such through holes 102a-102f are not provided in the dry-side end unit 102. For convenience, the through holes 102a-102f are shown as being substantially rectangular, but the shape of the through holes 102a-102f is not limited to this.

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

[0030] An oxidant gas supply compressor is connected to through-hole 102d, and oxidant gas compressed by the compressor is supplied to fuel cell stack 100 via through-hole 102d along dotted flow path PA4. This oxidant gas is guided via through-holes 214 and 304 to a 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 from through-hole 102c via through-holes 213 and 303 and along dotted flow path PA3.

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

[0032] The above is a schematic configuration of the fuel cell stack 100. Hereinafter, not only the joined front plate 3F and rear plate 3R, but also the front plate 3F and rear plate 3R will be referred to as separators 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 rear plate 3R before being joined together) are removed from the tray using the conveying device and conveyed to a location where a predetermined manufacturing process will be carried out.

[0033] 4 is a rear view (view from behind) of the separator 3. That is, FIG. 4 is a view showing the rear surface 3Rb of the rear plate 3R that faces the anode electrode 24 on the front surface 2a of the electrode unit 2. Point P in the figure is the midpoint in the left-right direction and the midpoint in the up-down direction of the separator 3, and is called the center point. The left-right direction and the up-down direction in FIG. 4 correspond to the longitudinal direction and the lateral direction of the separator 3, respectively.

[0034] 4, the region of the electrode unit 2 facing the assembly 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. Because 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 center region of the separator 3.

[0035] Of the inactive area, the regions at the left and right ends where the through holes 301 to 306 are provided are called edge regions AR2 of the separator 3. Of the inactive area, the regions inside the edge regions AR2 in the left and right directions are called connection regions AR3 of the separator 3. The connection regions AR3 are located between the active area AR1 and the left and right edge regions AR2.

[0036] Although some of the illustration is omitted, a plurality of protrusions 31 are provided in the active region AR1 of the separator 3, protruding rearward at equal intervals in the vertical direction over substantially the entire area. Each of the plurality of protrusions 31 extends in the horizontal direction, and a recess 32 is provided between adjacent protrusions 31 in the vertical direction. An anode flow path PAa (FIG. 2) is formed between the plurality of recesses 32 and the front surface 2a of the assembly 20.

[0037] More specifically, as shown in the enlarged view of part A in Fig. 4, the convex portion 31 and the concave portion 32 extend in the left-right direction while meandering in the up-down direction. Therefore, the vertical length of the convex portion 31, i.e., the length from the bottom end point P1 to the top end point P2 of the convex portion 31 (referred to as the convex portion meandering width) Wa, is longer than the vertical length of the convex portion 31 in a non-meandering state (referred to as the convex portion width). Also, the vertical length of the concave portion 32, i.e., the length from the bottom end point P3 to the top end point P4 of the concave portion 32 (referred to as the flow path meandering width) Wb, is longer than the vertical length of the concave portion 32 in a non-meandering state (referred to as the flow path width).

[0038] The convex portion meandering width Wa and the channel meandering width Wb are equal (Wa = Wb). The convex portion meandering width Wa may be greater than the channel meandering width Wb (Wa > Wb), or the channel meandering width Wb may be greater than the convex portion meandering width Wa (Wb > Wa). By meandering the recesses 32 in the left-right direction, the area of the anode channel PAa increases and the flow rate of the fuel gas flowing through the anode channel PAa slows. 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 a plurality of bead portions for sealing, i.e., metal bead seals, protruding rearward toward the frame 21. The plurality of bead portions include an outer bead portion 331, an inner bead portion 332, and an end bead portion 333. The connection region AR3 of the separator 3 is provided with a plurality of approximately cylindrical embossed portions 341, 342 protruding in the front-rear direction.

[0040] The protrusions 31, recesses 32, metal bead seals, etc. are formed by pressing the rear plate 3R. Although not shown in the drawings, the protrusions 31, recesses 32, metal bead seals, etc. are also formed on the front plate 3F by pressing the front plate 3F in the same manner.

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

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

[0043] The suction pad 60 has a rod portion 61 extending in the vertical direction 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, and the rod portion 61 may be supported by the hand 53 via the support member. The support member may be provided so that the suction pad 60 is movable 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 an internal cavity, and the side surfaces 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 contact portion 63 having a substantially rectangular frame shape is provided at the lower end of the pad portion 62. The contact portion 63 is made of an elastic body such as rubber. The lower end surface of the contact portion 63 is flat, and this lower end surface contacts the upper surface of the separator 3.

[0045] The rod portion 61 of the suction pad 60 is configured in a cylindrical shape, and an internal passage is connected to a vacuum generator 65. By generating a negative pressure (vacuum pressure) inside the pad portion 62 via the vacuum generator 65, the separator 3 can be sucked onto 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, the top of which is open. Separators 3 (front plates 3F, rear plates 3R) are stored in a stacked state on the tray 200. The tray 200 is placed at a first position. In response to a command from the ECU 56, the hand 53 moves from the first position to the second position while adsorbing the separator 3 with the adsorption pads 60. As a result, the separator 3 is transported 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, and the separator 3 is then placed on the mounting table 201. Thereafter, 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 adheres to the separator 3, if the contact portion 63 abuts against a flat, smooth surface of the surface of the separator 3, the suction force of the suction pad 60 due to negative pressure can be increased, making it easier to adhere the separator 3. However, as shown in Figure 4, the surface of the separator 3 is uneven in all of the active region AR1, the edge region AR2, and the connection region AR3, and there are no flat surfaces on which the suction pad 60 can abut.

[0049] If the separator 3 were configured to have a flat surface against which the suction pad 60 could come into contact, the separator 3 would become larger, resulting in increased costs. Furthermore, narrowing the active area AR1 to provide a flat surface against which the suction pad 60 could come into contact would result in a decrease in fuel cell performance. Therefore, in this embodiment, the separator 3 is configured to be adsorbed by having the abutment portion 63 of the suction pad 60 come into contact with the active area AR1 of the separator 3, in which the protrusions 31 and recesses 32 are regularly arranged.

[0050] The configuration of the suction pad 60 (particularly the contact portion 63) will be described. Figures 6A and 6B are plan views showing the configuration of contact portions 63A and 63B included in a thin plate conveying device as a reference example, respectively. Figures 6A and 6B show a state in which the contact portion 63A is in contact with an active area AR1 on 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 faces upward, and the longitudinal direction of the separator 3 (the left-right direction in Figure 4) is shown as the X1-X2 direction, and the lateral direction is shown as the Y1-Y2 direction. Figures 6A and 6B show the entire active area AR1 of the separator 3, and areas other than the active area AR1 are omitted from the illustration.

[0051] In the example of Fig. 6A, the thin plate conveying device has four suction pads 60A. The suction pads 60A are generally ring-shaped in plan view. The contact portions 63A of the four suction pads 60A are arranged at four locations around a center point P within the active area 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 part A in Fig. 6A, the lower end surfaces 63A1 of the contact portions 63A face the convex portions 31 and the concave portions 32 on the surface of the separator 3.

[0052] In this state, when the vacuum generator 65 is operated, 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 FIG. 6A, because the contact portion 63A is generally ring-shaped, the area of the lower end surface 63A1 facing the protrusion 31 is substantially equal to the area of the lower end surface 63A1 facing the recess 32. This increases the amount of air flowing into the inner space SPa of the contact portion 63A through the recess 32, making it difficult to create a sufficient negative pressure in the inner space SPa of the contact portion 63A. As a result, in order to obtain sufficient suction force for the separator 3, it is necessary to increase the capacity of the vacuum generator 65, which increases costs.

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

[0054] 6B, of the four side walls 63B11, 63B12, 63B13, and 63B14 of the abutting portion 63B, a lower end surface 63B1 of one side wall 63B11 extending in the X1-X2 direction abuts against the protrusion 31 of the separator 3, and a lower end surface 63B1 of the other side wall 63B13 faces the recess 32. In addition, the lower end surfaces 63B1 of the pair of side walls 63B12 and 63B14 extending in the Y1-Y2 direction alternately face the protrusion 31 and the recess 32. Therefore, more than half of the area of the lower end surface 63B1 of the suction pad 60B faces the recess 32. Therefore, when the vacuum generator 65 is operated, a large amount of air flows into the inner space SPb of the contact portion 63B as shown by the arrows through the gap between the lower end surface 63B1 and the recess 32, 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 a sufficient suction force for the separator 3, it is necessary to increase the capacity of the vacuum generator 65, which increases costs.

[0055] 7 is a plan view showing the configuration of the contact portion 63 of the suction pad 60 included in the thin plate conveying device 50 according to this embodiment. As shown in FIG. 7, the thin plate 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 arranged so that the center of the contact portion 63 is located at the center point P of the separator 3.

[0056] The abutment 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. The side walls 631, 633 are longer than the side walls 632, 634. For example, the length of the side walls 631, 633 is at least twice the length of the side walls 632, 634. The width W of the abutment portion 63 is constant around the entire periphery. In other words, the length (width W) of the side walls 631, 633 in the Y1-Y2 direction and the length (width W) of the side walls 632, 634 in the X1-X2 direction are equal to each other. As shown in the enlarged view of portion A in FIG. 7 , the width W of the abutment portion 63 is set to be wider than the flow path meandering width Wb.

[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 to drive the robot 55 so that the center of the suction pad 60 coincides with the center point P of the separator 3 at the first position. When the suction pad 60 moves to the first position, the lower end surfaces 630 of the side walls 631 and 632 abut against the upper surfaces of the protrusions 31 of the separator 3 over the entire length in the X1-X2 direction. More specifically, as shown in the enlarged view of part A in FIG. 7 , the lower end surfaces 630 of the side walls 631 and 633 abut against the upper surfaces of the pair of protrusions 31 that sandwich the recess 32.

[0058] This seals the lower end surfaces 630 of the side walls 631, 633. Therefore, when the vacuum generator 65 is activated to start suction of the separator 3 by the suction pad 60, it is possible to prevent air from flowing from the outer space SP2 of the contact portion 63 into the inner space SP1 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 of the suction pad 60. Once the separator 3 has been transported to the second position, the operation of the vacuum generator 65 is deactivated by a command from the ECU 56. As a result, the separator 3 is placed on the placement table 201 as shown in FIG. 5.

[0059] 8 is a reference example of FIG. 7, in which the width W of the abutting portion 63 is narrower than the flow path meander width Wb. In the example shown in FIG. 8, a portion of the recess 32 is exposed and not covered by the lower end surface 630 of the abutting portion 63 in a plan view. Therefore, the inner space SP1 and the outer space SP2 of the abutting portion 63 communicate with each other via the recess 32. As a result, as shown by the arrow in FIG. 8, air flows over the side wall 633 into the inner space SP0 of the abutting portion 63.

[0060] On the other hand, in this embodiment, the width W of the side walls 631, 633 is set wider than the flow path meander width Wb. Therefore, the lower end surfaces 630 of the side walls 631, 633 function as a seal. Although there is a gap between the lower end surfaces 630 of the side walls 632, 634 and the recess 32, the side walls 631, 633 are longer than the side walls 632, 634. Therefore, the amount of air that flows over the side walls 632, 634 from the outer space SP2 of the contact portion 63 into the inner space SP1 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, making it possible to easily suction the separator 3.

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

[0062] According to this embodiment, the following effects can be achieved. (1) The thin plate conveying device 50 is configured to convey a separator 3 having, on its surface, a plurality of recesses 32 and a plurality of protrusions 31 extending in the X1-X2 direction and arranged alternately in the Y1-Y2 direction (FIGS. 4 and 5). The thin plate conveying device 50 includes a contact portion 63 having a generally rectangular frame shape in a plan view that contacts the surface of the separator 3 arranged in a generally horizontal direction, a suction pad 60 that generates a suction force by negative pressure in an inner space SP1 of the contact portion 63, and a robot 55 that movably supports the suction pad 60 between a first position where the separator 3 is attracted to the contact portion 63 and a second position where the suction force is released (FIGS. 5 and 7). 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 that are shorter than the side walls 631, 633 and extend in the Y1-Y22 direction (FIG. 7). The width W of the side walls 631, 633 in the Y1-Y2 direction is greater than the width Wb (flow path meandering width) of the recess 32 in the Y1-Y2 direction (FIG. 7).

[0063] According to this configuration, the gap between the recess 32 of the separator 3 and the sidewalls 631, 633 of the suction pad 60 is sealed over the entire length of the sidewalls 631, 633, and the lower ends of the sidewalls 631, 633 function as a sealing portion. In this case, the sidewalls 631, 632 extending in the X1-X2 direction are longer than the sidewalls 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 allows the inner space SP0 of the suction pad 60 to be under negative pressure, generating a high suction force of the suction pad 60 to adhere to the separator 3. As a result, it is not necessary to configure the lower end surface of the contact portion 63 with an uneven surface, and an inexpensive suction pad 60 can be used to effectively suction the separator 3. Furthermore, it is not necessary to use a large-capacity vacuum generator 65, which helps prevent an increase in the cost 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 form the contact portion 63 of the suction pad 60 using a flexible material, but with this configuration, it becomes difficult to accurately position the separator 3 when the separator 3 is wavy or warped. In this regard, in the present embodiment, the separator 3 can be accurately positioned even when the separator 3 is wavy or warped.

[0064] (2) At the first position, the robot 55 supports the suction pad 60 so that the lower end surfaces of the side walls 631, 633 each abut against a pair of protrusions 31 that sandwich the recess 32 ( FIG. 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, 633, so that the flow of air into the internal space SP1 via the recess 32 can be reliably blocked.

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

[0066] (4) The thin plate conveying device 50 is applied to the conveyance of a separator 3 for a fuel cell, which has flow channels (anode flow channel PAa, cathode flow channel PAc) through which reactant gases flow, formed by a plurality of recesses 32 (FIG. 4). In such a separator 3, the recesses 32 and protrusions 31 are regularly arranged in the central active area AR1, making it an ideal application for the thin plate conveying device 50.

[0067] (5) The thin plate conveying device 50 has a single suction pad 60 arranged in the center of the separator 3 (FIG. 7). This allows the replacement of the pad portion 62 to be completed in a short time, since only a single pad portion 62 needs to be replaced.

[0068] The above embodiment can be modified in various ways. Some 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 multiple suction pads 60. FIG. 9 is a diagram showing one example. In FIG. 9, a pair of suction pads 60 of the same shape are provided. 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 the length in the X1-X2 direction of the contact portion 63 in FIG. 9 are the same as the width W and the length in the X1-X2 direction of the contact portion 63 in FIG. 7. Meanwhile, the length in the Y1-Y2 direction of the single contact portion 63 in FIG. 9 is half the length in the Y1-Y2 direction of the contact portion 63 in FIG. 7.

[0069] 9 also seals the gap between the recess 32 of the separator 3 and the side walls 631, 633 of the suction pad 60 over the entire length of the side walls 631, 633, and the lower ends of the side walls 631, 633 function as sealing portions. This allows a sufficient negative pressure to be generated in the inner space SP1 of the contact portion 63 of the recess 32, making it easy for the pair of suction pads 60 to suction the separator 3. Furthermore, because the suction pad 60 is positioned further away from the center point P in the Y1-Y2 direction than in the configuration of FIG. 7, the separator 3 can be stably supported over a wider area.

[0070] To prevent air from flowing into the internal space SP1 through gaps between the side walls 632, 634 of the suction pad 60 and the recess 32, seals may be provided on the side walls 632, 634. FIGS. 10A and 10B are vertical cross-sectional views of essential parts of the suction pad 60, showing an example of such a configuration. In FIG. 10A , a foam member 71 such as a contractile urethane foam is attached to the outer side surface of the side walls 632, 634 in the X1-X2 direction. The foam member 71 protrudes downward from the lower end surfaces of the side walls 632, 634. This forces a portion of the foam member 71 into the recess 32, thereby sealing the gap between the lower end surfaces of the side walls 632, 634 and the recess 32.

[0071] 10B, a flexible resin film member 72 is attached to the outer side surface of the side walls 632, 634 in the X1-X2 direction. The film member 72 protrudes downward from the lower end surfaces of the side walls 632, 634. The lower end of the film member 72 (the portion protruding downward from the lower end surfaces of the side walls 632, 634) has slits formed in the vertical direction at equal intervals in the Y1-Y2 direction, and the film member 72 is configured in a pleated shape. As a result, a portion of the film member 72 is pressed into the recess 32, and the gap between the lower end surfaces of the side walls 632, 634 and the recess 32 can be blocked.

[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 Wb (flow path meandering width) of the recess 32, but it may be set wider than the width Wa (protrusion meandering width) of the protrusion 31. This allows the lower end surfaces 630 of the side walls 631, 633 to abut against the upper surfaces of the protrusions 31 of the separator 3 positioned at the first position over the entire X1-X2 direction of the side walls 631, 633. 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 flow path meander width Wb may be wider than the convex portion meander width Wa. In this case, by setting the width W of the side walls 631, 633 wider than the convex portion meander width Wa, the width W of the side walls 631, 633 may be shorter than the flow path meander width Wb, and the width W of the side walls 631, 633 can be minimized. The convex portion meander width Wa may be wider than the flow path meander width Wb. In this case, by setting the width W of the side walls 631, 633 wider than the flow path meander width Wb, the width W of the side walls 631, 633 may be shorter than the convex portion meander width Wa, and the width W of the side walls 631, 633 can be minimized.

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

[0075] In the above embodiment, the suction pad 60 is supported by the robot 55 having an articulated arm so that it can be moved from the first position to the second position, but the configuration of the support unit is not limited to that described above. At the first position, the separator 3 is stored in the tray 200, and at the second position, the separator 3 is placed on the mounting table 201. However, the first and second positions may be different positions. In the above embodiment, with regard to the widths W of the side walls 631 to 634 of the abutting portion 63, the width W of the pair of side walls 631, 633 (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. However, the widths of the pair of first frame portions and 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 to the above-described embodiment and modifications as long as the features of the present invention are not impaired. One or more of the above-described embodiment and modifications can be arbitrarily combined, and modifications can also be combined with each other.

[0077] 3 separator, 31 convex portion, 32 concave portion, 50 thin plate conveying device, 55 robot, 100 fuel cell stack, 60 suction pad, 63 abutment portion, 631 to 634 side wall, Wa convex portion meandering width, Wb flow channel meandering width

Claims

1. A thin plate conveying device that conveys a thin plate having a surface including a plurality of recesses and a plurality of protrusions extending in a first direction and alternately arranged in a second direction perpendicular to the first direction, a suction pad having a contact portion having a substantially rectangular frame shape in a plan view, which contacts the surface of the thin plate disposed in a substantially horizontal direction, and which generates a suction force by negative pressure inside the contact portion; a support portion that movably supports the suction pad between a first position where the suction pad suctions the thin plate and a second position where the suction pad releases the suction, the abutment portion has a pair of first frame portions extending in the first direction and a pair of second frame portions extending in the second direction and shorter than the first frame portions, A thin plate conveying device characterized in that the width of the first frame portion in the second direction is wider than the width of the recessed portion in the second direction, or wider than the width of the protruding portion in the second direction.

2. The thin plate conveying device according to claim 1, a width of the first frame portion in the second direction is greater than a width of the recess portion in the second direction; The thin plate conveying device is characterized in that the support portion supports the suction pad so that the first frame portion abuts against the pair of protrusions that sandwich the recess at the first position.

3. The thin plate conveying device according to claim 1, a width of the first frame portion in the second direction is greater than a width of the protrusion portion in the second direction; The thin plate conveying device is characterized in that the support portion supports the suction pad so that, at the first position, the first frame portion is positioned across a pair of recesses that sandwich the protrusion portion.

4. The thin plate conveying device according to claim 1, The thin plate conveying device is characterized in that the plurality of recesses extend in the first direction while meandering in the second direction.

5. The thin plate conveying device according to any one of claims 1 to 4, The thin plate transport device is characterized in that the thin plate is a separator for a fuel cell in which flow channels through which reactant gases flow are formed by the plurality of recesses.

6. The thin plate conveying device according to claim 5, The thin plate conveying device is characterized in that the suction pad is a single suction pad arranged in the center of the separator.

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