Abstract:
A system for inspecting quality of a membrane-electrode assembly (MEA) of a fuel cell includes a bonding device configured to bond the MEA and a gas diffusion layer (GDL) to manufacture a bonded unit thereof. A transfer device adsorbs one surface of the bonded unit to transfer the bonded unit. An inspection device is disposed on one side of the bonded unit transferred by the transfer device and inspects an outer appearance of the bonded unit. A reversing device places the bonded unit thereon by the transfer device and reverses the bonded unit vertically. A loading and lifting device loads the bonded unit thereon after being transferred by the transfer device and adjusts a loading height.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of priority to Korean Patent Application No. 10-2015-0062654 filed in the Korean Intellectual Property Office on May 4, 2015, the entire content of which is incorporated herein by reference. 
       TECHNICAL FIELD 
       [0002]    The present disclosure relates to a system for inspecting quality of a membrane-electrode assembly (MEA) of a fuel cell, which bonds the MEA and a gas diffusion layer of the fuel cell and inspects the bonded unit, and a quality inspection method thereof. 
       BACKGROUND 
       [0003]    As known, a fuel cell produces electricity through an electrochemical reaction between hydrogen and oxygen. The fuel cell may continuously produce electrical energy upon receiving a chemical reactant from outside without having a separate charging process. 
         [0004]    A fuel cell may include separators (or bipolar plates) which are disposed on both sides of a membrane-electrode assembly (MEA) therebetween. A plurality of fuel cells may be arranged to form a fuel cell stack. 
         [0005]    In the MEA, a core part of the fuel cell and an anode and a cathode as electrode catalyst layers are formed on both sides of an electrolytic membrane to transfer hydrogen ions. The MEA further includes a sub-gasket to protect the electrode catalyst layers and the electrolytic membrane and to secure assembly characteristics of the fuel cell. 
         [0006]    When manufacturing the foregoing MEA, an electrode membrane sheet unwinds the electrolytic membrane which is wound in the form of a roll and continuously transfers electrode catalyst layers to be spaced apart by approximately, 150 mm pitch on both surfaces of the electrolytic membrane. 
         [0007]    In a post-process, the electrode membrane sheet wound in the form of a roll is unwound and transferred, sub-gaskets in the form of a roll are unwound to be positioned on both surfaces of the electrode membrane sheet. The sub-gaskets and the electrode membrane sheet pass through between hot rollers such that the sub-gaskets are bonded to both surfaces of the electrode membrane sheet, thus manufacturing an MEA sheet in a roll-to-roll manner. 
         [0008]    In addition, the MEA and a gas diffusion layer (GDL) are bonded at a high temperature, in which bonded assemblies and separators are alternately stacked to manufacture a fuel cell. 
         [0009]    Research into a quality inspection system for inspecting quality of the assemblies and preventing a defective product from being applied to a fuel cell has been conducted. 
         [0010]    The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention, and therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. 
       SUMMARY 
       [0011]    The present disclosure has been made in an effort to provide a system for inspecting quality of a membrane-electrode assembly (MEA) of a fuel cell having advantages of enhancing quality of a fuel cell by easily checking quality of a bonded unit obtained by bonding the MEA and a gas diffusion layer (GDL), and using only the bonded unit. 
         [0012]    According to an exemplary embodiment of the present inventive concept, a system for inspecting quality of a membrane-electrode assembly (MEA) of a fuel cell, including: a bonding device configured to bond the MEA and a gas diffusion layer (GDL) to manufacture a bonded unit thereof. A transfer device adsorbs one surface of the bonded unit to transfer the bonded unit. An inspection device is disposed on one side of the bonded unit transferred by the transfer device and inspects an outer appearance of the bonded unit. A reversing device places the bonded unit thereon by the transfer device and reverses the bonded unit vertically. A loading and lifting device loads the bonded unit to thereon after being transferred by the transfer device and adjusts a loading height. 
         [0013]    The bonding device may bond the MEA and the GDL with a preset pressure and at a preset temperature and transfer the bonded MEA and GDL through a conveyer. 
         [0014]    The system may further include an aligning device correcting a position of the bonded unit on the conveyer. 
         [0015]    The transfer device may vacuum-adsorb an upper surface of the bonded unit and transfer the bonded unit through a three-dimensional route. 
         [0016]    The inspection device may inspect a displacement of the outer appearance of the bonded unit by using a laser and determine a bonding state of the bonded unit according to a displacement value. 
         [0017]    The reversing device may include clampers disposed on both sides thereof to clamp both end portions of the bonded unit and may vertically reverse the bonded unit in a state in which the clampers clamp both end portions of the bonded unit. 
         [0018]    The loading and lifting device may vary the loading height of the loaded bonded unit by rotating a screw. 
         [0019]    The transfer device may vacuum-adsorb an upper surface of the bonded unit, and the inspection device may be disposed below the bonded unit. 
         [0020]    When the bonded unit inspected by the inspection device meets conditions for the outer appearance, the bonded unit may be loaded in the loading and lifting device. When the bonded unit does not meet the conditions, the bonded unit may be taken out to the outside. 
         [0021]    The inspection device may include an inspection vision sensing or displaying the outer appearance of the bonded unit on a screen. 
         [0022]    According to another exemplary embodiment of the present inventive concept, a method for inspecting quality of a membrane-electrode assembly (MEA) of a fuel cell includes bonding the MEA and a gas diffusion layer (GDL) to each other. One surface of the bonded unit is vacuum adsorbed and the bonded unit is transferred. An outer appearance of another surface of the bonded unit is sensed while transferring the one vacuum-adsorbed surface of the bonded unit. The bonded unit is vertically reversed. The other surface of the vertically reversed bonded unit is vacuum-adsorbed and the bonded unit is transferred. An outer appearance of the one surface of the bonded unit is sensed while transferring the other vacuum-adsorbed surface of the bonded unit. When the bonded unit having one surface and the other surface thereof inspected meets conditions for the outer appearance, the bonded unit is loaded. 
         [0023]    The method may further include taking out the bonded unit when the bonded unit having the outer appearance of one surface or the other surface is inspected does not meet the conditions for the outer appearance. 
         [0024]    The method may further include correcting a position of the bonded unit in a width direction of a conveyer when the bonded unit is manufactured and transferred on the conveyer. 
         [0025]    The step of reversing the bonded unit may include clamping both end portions of the bonded unit by using clamps, and reversing upper and lower surfaces of the bonded unit by rotating the clamps. 
         [0026]    The step of sensing the outer appearance may include sensing a displacement of the outer appearance of the bonded unit by irradiating a laser, and determining a bonding state of the bonded unit according to a magnitude of the displacement. 
         [0027]    When the magnitude of the displacement is within a preset range, the bonded unit may be loaded in a loading and lifting device. When the magnitude of the displacement is not within the preset range, the bonded unit may be taken out. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0028]    The drawings are used to be referred to in describing exemplary embodiments of the present inventive concept, so a technical concept of the present disclosure should not be meant to restrict the invention to the accompanying drawings. 
           [0029]      FIG. 1  is a schematic view illustrating a configuration of a system for inspecting quality of a membrane-electrode assembly (MEA) of a fuel cell according to an exemplary embodiment of the present inventive concept. 
           [0030]      FIG. 2  is a flow chart illustrating a method for inspecting quality of an MEA of a fuel according to an exemplary embodiment of the present inventive concept. 
           [0031]      FIGS. 3A-3C  are schematic views illustrating a configuration of portions of a bonding device, a transfer device, and an inspection device of the system for inspecting quality of an MEA of a fuel cell according to an exemplary embodiment of the present inventive concept. 
           [0032]      FIGS. 4A-4C  are perspective views illustrating portions of a reversing device, the transfer device, and a loading and lifting device of the system for inspecting quality of an MEA of a fuel cell according to an exemplary embodiment of the present inventive concept. 
           [0033]      FIGS. 5A and 5B  are a perspective view and a graph illustrating an inspection method using a laser displacement sensor of the system inspecting quality of an MEA of a fuel cell according to an exemplary embodiment of the present inventive concept and a result thereof. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0034]    Hereinafter, the present disclosure will be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present disclosure. 
         [0035]    In order to clearly describe the present disclosure, a portion irrelevant to a description of the present disclosure will be omitted, and like reference numerals refer to like elements throughout. 
         [0036]    In the drawings, sizes and thickness of components are arbitrarily shown for the description purposes, so the present disclosure is not limited to the illustrations of the drawings and thicknesses are exaggerated to clearly express various parts and regions. 
         [0037]    In the following descriptions, terms such as “first” and “second,” etc., may be used only to distinguish one component from another as pertinent components are named the same, and order thereof is not limited. 
         [0038]    Throughout the specification, unless explicitly described to the contrary, the word “comprise” and variations such as “comprises” or “comprising” will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. 
         [0039]      FIG. 1  is a schematic view illustrating a configuration of a system for inspecting quality of a membrane-electrode assembly (MEA) of a fuel cell according to an exemplary embodiment of the present inventive concept. 
         [0040]    Referring to  FIG. 1 , a quality inspection system  100  includes a bonding device  105 , a transfer device  110 , an inspection device  115 , a reversing device  120 , and a loading and lifting device  125 . 
         [0041]    The bonding device  105  compresses a membrane-electrode assembly (MEA) and a gas diffusion layer (GDL) at a preset temperature and a preset pressure using two hot rollers, and here, the MEA and the GDL are stacked on a conveyer  300  and the stacked unit is compressed by the hot rollers to manufacture a bonded unit  310  (see  FIGS. 3A-3C ). A detailed structure of the bonding device  105  may be referred to a known art. 
         [0042]    The transfer device  110  vacuum-adsorbs an upper surface of the bonded unit  310  and unloads the bonded unit  310  from the bonding device  105  along a preset route in a three-dimensional space, and transfers the bonded unit  310  to the inspection device  115 , the vertically reversing device  120 , and the loading and lifting device  125 . 
         [0043]    The inspection device  115  may inspect an outer appearance of a lower surface of the bonded unit  310  and display a corresponding result or transmit the result to a controller (not shown) having a separate calculation unit. 
         [0044]    The inspection device  115  may include an inspection vision  340  or a laser displacement sensor  350 . The inspection vision  340  may store the outer appearance of the bonded unit  310  on a screen or display the same, and the laser displacement sensor  350  irradiates a laser to the bonded unit  310  to sense a displacement of an outer appearance of the bonded unit  310 . 
         [0045]    The vertically reversing device  120  reverses an upper surface and a lower surface of the bonded unit  310 . That is, the vertically reversing device  120  clamps both end portions of the bonded unit  310  and rotates the bonded unit  310  by  180  degrees with respect to a central axis in a length direction. 
         [0046]    The bonded unit  310  reversed by the vertically reversing device  120  is vacuum-adsorbed again by the transfer device  110  and inspected by the inspection device  115 , and the inspected bonded unit  310  is loaded on the loading and lifting device  125  or taken out. 
         [0047]      FIGS. 3A-3C  are schematic views illustrating a configuration of portions of a bonding device, a transfer device, and an inspection device of the system for inspecting quality of an MEA of a fuel cell according to an exemplary embodiment of the present inventive concept. 
         [0048]    Referring to  FIGS. 3A-3C , the bonding device  105  includes a conveyer  300  moving by a driving roller, and the bonded unit  310  is transferred on the conveyer  300  by a hot roller. An aligning device  320  adjusting a position of the bonded unit  310  is provided on both sides of the conveyer  300 , and an alignment error may be within 0.5 mm. 
         [0049]    The transfer device  110  may include a linear guide  360  and a vacuum adsorbing unit  332  disposed in a horizontal direction. The vacuum adsorbing unit  332  may move in a horizontal direction along the linear guide  360  or move up and down simultaneously. Further, the vacuum adsorbing unit  332  may vacuum-adsorb an upper surface of the bonded unit  310  by using vacuum pressure and transfers the bonded unit  310 . 
         [0050]    When the bonded unit  310  is transferred by the vacuum adsorbing unit  332  and the linear guide  360 , the inspection vision  340  and the laser displacement sensor  350  disposed below the vacuum adsorbing unit  332  sequentially sense an outer appearance of the lower surface of the bonded unit  310 . 
         [0051]      FIGS. 4A-4C  are perspective views illustrating portions of a reversing device, the transfer device, and a loading and lifting device of the system for inspecting quality of an MEA of a fuel cell according to an exemplary embodiment of the present inventive concept. 
         [0052]    Referring to  FIGS. 4A-4C , the reversing device  120  includes clampers  410  clamping both end portions of the bonded unit  310  and a rotating unit  440  rotating the clampers  410 . 
         [0053]    The transfer device  110  transfers the bonded unit  310  to the reversing device  120 , the clampers  410  clamp both end portions of the bonded unit  310 , and rotate the bonded unit  310  by  180  degrees by means of the rotating unit  440 . 
         [0054]    Thereafter, while the transfer device  110  transfers the bonded unit  310  which is  180  degree rotated again, the inspection vision  340  and the laser displacement sensor  350  inspect a lower surface of the bonded unit  310 . 
         [0055]    Finally, when the bonded unit  310 , which has been inspected by the inspection vision  340  and the laser displacement sensor  350 , is passed, the bonded unit  310  is loaded in the loading and lifting device  125 . When the bonded unit  310  fails to pass the inspection, the bonded unit  310  is taken out. Here, the loading and lifting device  125  may be lifted or lowered the loaded bonded units  310  through the screw  430  and the rotating unit  440 . 
         [0056]      FIGS. 5A and 5B  are a perspective view and a graph illustrating an inspection method using a laser displacement sensor of the system inspecting quality of an MEA of a fuel cell according to an exemplary embodiment of the present inventive concept and a result thereof. 
         [0057]    Referring to  FIG. 5A , the laser displacement sensor  350  irradiates a laser to a lower surface of the bonded unit  310  and senses a reflected laser, thereby sensing a displacement of an outer appearance of a sub-gasket and a displacement of an outer appearance of the GDL in the bonded unit  310 . 
         [0058]    Referring to  FIG. 5B , the horizontal axis represents an inspection width and the vertical axis represents a displacement of an outer appearance. 
         [0059]    The displacements include a displacement of the GDL and a displacement of the sub-gasket, and when the displacement of the GDL is outside of a preset range, the GDL may be determined to be in a non-bonded (separated) state. 
         [0060]    When the displacement of the sub-gasket is outside of a preset range, the sub-gasket may be determined to be in a non-bonded (separated) state, and a partially non-bonding state or a completely non-bonding state may be determined according to a size of a separated range. 
         [0061]    In the present disclosure, the bonding device  105 , the transfer device  110 , the inspection device  115 , the reversing device  120 , and the loading and lifting device  125  may be controlled by a control unit (not shown), and pass and failure of the bonding device  105  inspected by the inspection device  115  may also be determined by the controller. 
         [0062]    The controller may be implemented as one or more micro-processors operated according to a preset program, and the preset program may include a series of commands for performing the method according to an exemplary embodiment of the present inventive concept to be described below. 
         [0063]      FIG. 2  is a flow chart illustrating a method for inspecting quality of an MEA of a fuel cell according to an exemplary embodiment of the present inventive concept. 
         [0064]    Referring to  FIG. 2 , the MEA and the GDL are bonded in step S 210 . The transfer device  110  vacuum-adsorbs an upper surface of the bonded unit  310  to lift the bonded unit  310  and transfers the lifted bonded unit  310  along a preset route in step S 220 . 
         [0065]    The inspection device  115  inspects an outer appearance of one surface of the bonded unit  310  by using the inspection vision  340  and the laser displacement sensor  350  in step S 230 . 
         [0066]    The bonded unit  310  is loaded to the reversing device  120  and fixed by the clampers  410  in step S 240 . The bonded unit  310  rotates by  180  degrees in step S 250 . 
         [0067]    An outer appearance of the other surface of the bonded unit  310  is inspected by using the inspection device  115  in step S 260 . The inspected bonded unit  310  is transferred by the transfer device  110  in step S 270 , and when passed, the bonded unit  310  is loaded in the loading and lifting device  125  and when failed, the bonded unit  310  is taken out to the outside in step S 280 . 
         [0068]    While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.