Abstract:
A hot press device presses one or more objects to be pressed at a predetermined temperature, and includes: a roller around which a roll on which the objects to be pressed are disposed at predetermined intervals is wound; hot plates which are disposed to face one surface of the objects to be pressed while corresponding to the roll supplied from the roller; press units which are disposed to push the hot plates on the objects to be pressed; and a pitch changing unit which moves the hot plates in a direction in which the roll is moved or in a direction opposite to a direction in which the roll is moved, in accordance with a distance between the objects to be pressed.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims under 35 U.S.C. §119(a) the benefit of Korean Patent Application No. 10-2015-0098671 filed in the Korean Intellectual Property Office on Jul. 10, 2015, the entire contents of which are incorporated herein by reference. 
       BACKGROUND 
       [0002]    (a) Field of the Invention 
         [0003]    The present invention relates to a hot press device and a method of hot pressing a membrane-electrode assembly (MEA) including an electrolyte membrane, an electrode, and a sub-gasket. 
         [0004]    (b) Description of the Related Art 
         [0005]    It is known that a fuel cell generates electricity through an electrochemical reaction of hydrogen and oxygen. A fuel cell can consistently generate electricity by being supplied with chemical reactants from the outside without a separate charging process. 
         [0006]    A fuel cell may be constructed such that separators (separating plates or bipolar plates) are disposed at both sides of a membrane-electrode assembly (MEA) interposed between the separators. 
         [0007]    Here, the membrane-electrode assembly has an anode layer formed on one surface of the electrolyte membrane, and a cathode layer formed on the other surface of the electrolyte membrane, and the electrolyte membrane is disposed between the anode layer and the cathode layer. Further, the membrane-electrode assembly has a sub-gasket which opens the anode layer and the cathode layer and is bonded to both edge portions of the electrolyte membrane. 
         [0008]    An automated system, which automatically implements the entire process from a process of bonding the membrane-electrode assembly made in the form of a roll to a pinching process, has been disclosed. In particular, the membrane-electrode assembly may be loaded to a bonding press, and the bonding press bonds the electrolyte membrane and the electrode at a high temperature and under high pressure. 
         [0009]    Meanwhile, the membrane-electrode assembly in the form of a single long roll undergoes a hot press process. However, a distance between the membrane-electrode assemblies on the single roll varies, and as a result, precision of the hot press process may deteriorate. 
         [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 invention provides a hot press device and a hot press method, which are capable of precisely performing a hot press process in a state in which a distance between membrane-electrode assemblies arranged on a membrane-electrode assembly (MEA) roll varies, thereby improving productivity of a fuel cell. 
         [0012]    An exemplary embodiment of the present invention provides a hot press device which presses one or more objects to be pressed at a predetermined temperature, the hot press device including: a roller around which a roll on which the objects to be pressed are disposed at predetermined intervals is wound; hot plates which are disposed to face one surface of the objects to be pressed while corresponding to the roll supplied from the roller; press units which are disposed to push the hot plates on the objects to be pressed; and a pitch changing unit which moves the hot plates in a direction in which the roll is moved or in a direction opposite to a direction in which the roll is moved, in accordance with a distance between the objects to be pressed. 
         [0013]    The objects to be pressed may be membrane-electrode assemblies, and the roll may be an MEA roll. 
         [0014]    The hot plates may include first, second, and third hot plates that are disposed at predetermined intervals in a direction in which the membrane-electrode assemblies are arranged, and the pitch changing unit may move at least one of the first, second, and third hot plates forward or rearward. 
         [0015]    The pitch changing unit may move the first hot plate forward or rearward on the basis of the second hot plate. 
         [0016]    The pitch changing unit may move the third hot plate forward or rearward on the basis of the second hot plate. 
         [0017]    The second hot plate may be fixed, and the first and third hot plates may be disposed to be moved forward or rearward. 
         [0018]    The first, second, and third hot plates may be disposed at upper and lower sides so as to correspond to both surfaces of the membrane-electrode assemblies, respectively. 
         [0019]    The pitch changing unit may include: a servo motor; a screw which is disposed to be rotated by the servo motor; and a moving block which is fastened to the screw, and disposed to be moved in both directions depending on a rotation direction of the screw, and at least one of the first, second, and third hot plates may be disposed to be moved in both directions together with the moving block. 
         [0020]    The hot press device may further include: a pitch detecting unit which detects a pitch between the membrane-electrode assemblies disposed on the MEA roll; and a control unit which controls the pitch changing unit based on the pitch between the membrane-electrode assemblies which is detected by the pitch detecting unit. 
         [0021]    The hot press device may further include: an unwinder roller which rotates to supply the wound MEA roll to the hot press device; and a rewinder roller which rotates to wind the MEA roll to unload the MEA roll from the hot press device. 
         [0022]    A soft film may be fixedly disposed on one surface of at least one of the first, second, and third hot plates so as to face the membrane-electrode assembly, and the soft film may have a protruding portion formed to correspond to a shape of the membrane-electrode assembly. 
         [0023]    The press unit may include: a moving frame which is disposed to face one surface of the MEA roll; and a cylinder which pushes the moving frame on the membrane-electrode assembly, and the moving block may be slidably connected to the moving frame. 
         [0024]    Another exemplary embodiment of the present invention provides a hot press method including: adjusting positions of hot plates, which press objects to be pressed at a predetermined temperature, in accordance with an interval between the objects to be pressed; pressing the hot plates on both surfaces of the objects to be pressed using predetermined force; and separating the hot plates pressed on the objects to be pressed. 
         [0025]    The objects to be pressed may be arranged on a roll at predetermined intervals, and the roll may be loaded between the hot plates. 
         [0026]    The objects to be pressed may be membrane-electrode assemblies, and the roll may be an MEA roll. 
         [0027]    The hot plates may include first, second, and third hot plates disposed at predetermined intervals in a direction in which the membrane-electrode assemblies are arranged, and in the adjusting of the positions of the hot plates, at least one of the first, second, and third hot plates may be moved forward or rearward. 
         [0028]    In the adjusting of the positions of the hot plates, the second hot plate may be fixed, and the first and third hot plates may be moved forward or rearward. 
         [0029]    In the exemplary embodiment of the present invention, the positions of the hot plates are adjusted in accordance with the pitch between the membrane-electrode assemblies disposed on the MEA roll, thereby more precisely hot pressing the membrane-electrode assembly using the hot plates. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]    The drawings are intended to be used as references for describing the exemplary embodiments of the present invention, and the accompanying drawings should not be construed as limiting the technical spirit of the present invention. 
           [0031]      FIG. 1  is a configuration view of an apparatus for manufacturing fuel cell stack components associated with the present invention. 
           [0032]      FIG. 2  is a partial configuration view of the apparatus for manufacturing fuel cell stack components according to an exemplary embodiment of the present invention. 
           [0033]      FIG. 3  is a partial cross-sectional view of the apparatus for manufacturing the fuel cell stack components according to the exemplary embodiment of the present invention. 
           [0034]      FIG. 4  is a flowchart illustrating a hot press method according to the exemplary embodiment of the present invention. 
           [0035]      FIG. 5  is a partial cross-sectional view illustrating a structure of a pitch changing unit in the hot press method according to the exemplary embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0036]    The present invention will be described more fully hereinafter 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 invention. 
         [0037]    The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 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. In addition, the terms “unit”, “-er”, “-or”, and “module” described in the specification mean units for processing at least one function and operation, and can be implemented by hardware components or software components and combinations thereof. A part irrelevant to the description will be omitted to clearly describe the present invention, and the same or similar constituent elements will be designated by the same reference numerals throughout the specification. 
         [0038]    The size and thickness of each component illustrated in the drawings are arbitrarily shown for understanding and ease of description, but the present invention is not limited thereto. Thicknesses of several portions and regions are enlarged for clear expressions. 
         [0039]    Further, the control logic of the present invention may be embodied as non-transitory computer readable media on a computer readable medium containing executable program instructions executed by a processor, controller or the like. Examples of computer readable media include, but are not limited to, ROM, RAM, compact disc (CD)-ROMs, magnetic tapes, floppy disks, flash drives, smart cards and optical data storage devices. The computer readable medium can also be distributed in network coupled computer systems so that the computer readable media is stored and executed in a distributed fashion, e.g., by a telematics server or a Controller Area Network (CAN). 
         [0040]      FIG. 1  is a configuration view of an apparatus for manufacturing fuel cell stack components associated with the present invention. 
         [0041]    Referring to  FIG. 1 , the apparatus for manufacturing fuel cell stack components includes an unwinder roller  100 , an MEA roll  102 , membrane-electrode assemblies  105 , protective films  115 , protective film rollers  110 , first hot plates  120 , second hot plates  122 , press units  130 , cylinders  132 , pressing frames  140 , third hot plates  124 , and a rewinder roller  101 . 
         [0042]    The membrane-electrode assemblies  105  are disposed on the MEA roll  102 , intervals between the respective membrane-electrode assemblies  105  may be the same, or the respective membrane-electrode assemblies  105  may be non-uniformly disposed with a first pitch P 1  and a second pitch P 2 . 
         [0043]    The MEA roll  102  is wound around the unwinder roller  100 , and the MEA roll  102  wound around the unwinder roller  100  is unwound and then rewound around the rewinder roller  101 . 
         [0044]    The first, second, and third hot plates  120 ,  122 , and  124  are disposed at upper and lower sides of the MEA roll  102  so as to face each other, respectively, and the first, second, and third hot plates  120 ,  122 , and  124  are moved upward and downward by the pressing frames  140 , thereby hot pressing the membrane-electrode assemblies  105 . 
         [0045]    Further, the MEA roll  102 , which moves from the unwinder roller  100  to the rewinder roller  101 , passes through the first hot plates  120 , the second hot plates  122 , and the third hot plates  124 . 
         [0046]    The pressing frames  140  are moved upward and downward by the press units  130 , and the press units  130  include the cylinders  132  that move the pressing frames  140  upward and downward. The cylinders  132  may be driven by hydraulic pressure. 
         [0047]    The protective film  115  is supplied from the protective film roller  110  to a portion between the MEA roll  102  and the first, second, and third hot plates  120 ,  122 , and  124  that are disposed at the upper side of the MEA roll  102 , and the protective film  115  is supplied from the protective film roller  110  to a portion between the MEA roll  102  and the first, second, and third hot plates  120 ,  122 , and  124  that are disposed at the lower side of the MEA roll  102 . 
         [0048]      FIG. 2  is a partial configuration view of the apparatus for manufacturing fuel cell stack components according to an exemplary embodiment of the present invention. 
         [0049]    Referring to  FIG. 2 , the first hot plates  120 , the second hot plates  122 , and the third hot plates  124  are disposed at the upper and lower sides, respectively, the MEA roll  102  passes between the first, second, and third hot plates  120 ,  122 , and  124 , and the first, second, and third hot plates  120 ,  122 , and  124  are disposed on the pressing frames  140  in order to hot press the membrane-electrode assemblies  105 , respectively. 
         [0050]    In the exemplary embodiment of the present invention, the second hot plates  122 , which are disposed between the first and third hot plates  120  and  124 , are fixed to the pressing frames  140 , and the first and third hot plates  120  and  124  are disposed to be movable by a predetermined distance in a movement direction of the MEA roll  102 . 
         [0051]    First variable pitch servo motors  200  may adjust a distance from the second hot plates  122  by pulling or pushing the first hot plates  120 , and second variable pitch servo motors  205  may adjust a distance from the second hot plates  122  by pulling and pushing the third hot plates  124 . 
         [0052]    Therefore, even though the membrane-electrode assemblies  105  are arranged on the MEA roll  102  with non-uniform pitches, positions of the first and third hot plates  120  and  124  are changed on the basis of the second hot plates  122 , thereby more precisely performing a hot pressing process. 
         [0053]      FIG. 3  is a partial cross-sectional view of the apparatus for manufacturing the fuel cell stack components according to the exemplary embodiment of the present invention. 
         [0054]    Referring to  FIG. 3 , the apparatus for manufacturing the fuel cell stack components includes first hot plates  120 , soft films  300 , protruding portions  305 , and a membrane-electrode assembly  105 , and the membrane-electrode assembly  105  includes an electrolyte membrane  320 , electrodes  330 , and sub-gaskets  310 . 
         [0055]    The protective film  115  is attached onto one surface of each of the first hot plates  120  so as to face the membrane-electrode assembly  105 , and the protruding portions  305  are formed on the protective films  115  so as to correspond to the shape of the membrane-electrode assembly  105 . 
         [0056]    Therefore, the first hot plates  120  are hot pressed so that the protruding portions  305  are inserted into grooves of the membrane-electrode assembly  105 , thereby improving precision of the hot pressing process. 
         [0057]    In particular, in the exemplary embodiment of the present invention, even though the membrane-electrode assemblies  105  are arranged on the MEA roll  102  with non-uniform pitches, it is possible to more precisely perform the hot pressing process by changing the positions of the first and third hot plates  120  and  124  on the basis of the second hot plates  122 . 
         [0058]      FIG. 4  is a flowchart illustrating a hot press method according to the exemplary embodiment of the present invention. 
         [0059]    Referring to  FIG. 4 , in step S 400 , the membrane-electrode assemblies  105  are disposed between the first, second, and third hot plates  120 ,  122 , and  124 , respectively, by moving the MEA roll  102  from the unwinder roller  100  to the rewinder roller  101 , and in step S 410 , intervals (pitches) between the membrane-electrode assemblies  105  arranged on the MEA roll  102  are detected. 
         [0060]    Next, intervals between the first and third hot plates  120  and  124  are adjusted to correspond to the intervals between the membrane-electrode assemblies  105  which are detected in step S 420 , and in step S 430 , the hot pressing process is carried out by using the first, second, and third hot plates  120 ,  122 , and  124 . 
         [0061]    Next, in step S 440 , the first, second, and third hot plates  120 ,  122 , and  124  are separated from the membrane-electrode assemblies  105 , and in step S 450 , the MEA roll  102  is unloaded from the first, second, and third hot plates  120 ,  122 , and  124 . 
         [0062]      FIG. 5  is a partial cross-sectional view illustrating a structure of a pitch changing unit in the hot press method according to the exemplary embodiment of the present invention. 
         [0063]    Referring to  FIG. 5 , the pitch changing unit includes a moving block  507  which is slidably disposed on the pressing frame  140  by means of a slider  510 , and the first hot plate  120  which is fastened to the moving block  507  so as to be moved together with the moving block  507 . 
         [0064]    A screw  505  is disposed to penetrate the moving block  507 , and the moving block  507  is disposed on the pressing frame  140  so as to be reciprocally moved by rotation of the screw  505 . 
         [0065]    One end of the screw  505  is connected to the first variable pitch servo motor  200 , and the first variable pitch servo motor  200  is fixed to the pressing frame  140  by means of a fixed block  500 . 
         [0066]    A control unit  550  receives a pitch signal from a pitch detecting unit  555  that detects a pitch between the membrane-electrode assemblies  105 , and based on the pitch signal, the first variable pitch servo motor  200  is operated to adjust the position of the first hot plate  120 . 
         [0067]    In the exemplary embodiment of the present invention, the pitch detecting unit  555  may include sensors that detect positions of the membrane-electrode assemblies  105 , respectively. 
         [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.