Patent Publication Number: US-2016226436-A1

Title: Solar cell module

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of International Application No. PCT/JP2013/075657, filed on Sep. 24, 2013, entitled “SOLAR CELL MODULE”, which claims priority based on the Article 8 of Patent Cooperation Treaty from prior Japanese Patent Application No. 2012-215771, filed on Sep. 28, 2012, the entire contents of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The disclosure relates to a solar cell module. 
     BACKGROUND ART 
     As an environment-friendly energy source, solar cell modules have attracted increasing attention in recent years. 
     A solar cell module includes: a module body including solar cells; and a frame provided around the module body. In a usual practice, the frame is formed by connecting four frame pieces, which are provided on the sides of the module body. Japanese Patent Application Publication No. 2005-294455 (Patent Document 1) discloses frames that are connected together by screws. 
     SUMMARY 
     One problem in the art has been that if water stays inside the frame of a solar panel, the frame is likely to break due to expansion of water that freezes as the temperature of the atmosphere of the solar cell module falls. For this reason, the solar cell module needs to be designed to facilitate discharge of water inside the frame. 
     However, in reality, for the solar cell module equipped with the frame including the screwed frame pieces, study has been made on a solar cell module, which facilitates discharge of water from inside a frame. 
     A solar cell module according to an embodiment described herein that alleviates the problem includes a rectangular module body and a frame. The module body includes a first surface and a second surface on an opposite side from the first surface. The module body includes a solar cell. The frame is provided surrounding the module body. The frame includes a long-side frame piece, a short-side frame piece, and a fixation screw. The long-side frame piece is provided outside a long side part of the module body. The short-side frame piece is provided outside a short side part of the module body. The screw fixes the long-side frame piece and the short-side frame piece to each other. The long-side frame piece includes a cylindrical part in which a through hole is formed from one end portion to an opposite end portion thereof in an extending direction of the long-side frame piece. The cylindrical part includes a screw hole provided inside the through hole, and the screw is inserted into the screw hole. The short-side frame piece includes a plate-shaped part configured to cover art end portion of the cylindrical part in the extending direction of the long-side frame piece, and an opening is formed in the plate-shaped part. The screw penetrates the opening when inserted into the screw hole. A cutout is formed in the plate-shaped part. The cutout exposes a portion of the through hole on a first direction side outside the screw hole in a first direction pointing from the first surface to the second surface of the module body. This structure provided great benefit of alleviating the freezing problem. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic plan view of a solar cell module of an embodiment. 
         FIG. 2  is a diagram of module body  10  and frame  20  separated from the solar cell module of the embodiment. 
         FIG. 3  is a diagram of showing how a long-side frame piece and a short-side frame piece of the embodiment are connected together. 
         FIG. 4  is a schematic side view of the solar cell module viewed in an arrow IV direction of  FIG. 1 . 
         FIG. 5  is a schematic exploded perspective view of a frame of the embodiment. 
         FIG. 6  is a schematic cross-sectional view of the long-side frame piece taken along the VI-VI line of  FIG. 1 . 
         FIG. 7  is a schematic side view of the short-side frame piece of the embodiment. 
         FIG. 8  is a schematic cross-sectional view of the short-side frame piece taken along the VIII-VIII line of FIG.  7 . 
     
    
    
     DETAILED DESCRIPTION 
     Descriptions are hereinbelow provided for an example of a preferred embodiment. The following embodiment is shown just as an example and does not limit the claimed invention. 
     In the drawings to which the embodiment and the like refer, members playing virtually the same functions are denoted by the same reference numerals. The drawings to which the embodiment and the like refer are schematic representations. Dimensional ratios of objects depicted in the drawings may differ from those of the actual objects. The dimensional ratios of the objects may differ from one drawing to another as well. Concrete dimensional ratios of the objects need to be determined with the following descriptions taken into consideration. 
       FIG. 1  is a schematic plan view of a solar cell module of an embodiment.  FIG. 2  is a diagram of module body  10  and frame  20  separated from solar cell module  1  illustrated in  FIG. 1 . In  FIG. 2 , dotted lines on module body  10  represent a location in which to place frame  20 . 
     As illustrated in  FIGS. 1 and 2 , solar cell module  1  includes module body  10  and frame  20 . 
     Module body  10  is shaped like a rectangle, when viewed in a z-axis direction. Nodule body  10  includes first and second long side parts  10   a,    10   b,  and first and second short side parts  10   c,    10   d.  First and second long side parts  10   a,    10   b  are parallel to each other, and extend in an x-axis direction. First and second short side parts  10   c,    10   d  are parallel to each other, and extend in a v-axis direction. 
     Module body  10  includes solar cells  11 . To put it concretely, module body  10  includes solar cells  11  which are electrically connected with wiring members (not illustrated). First protection member  12  is disposed on the light reception surfaces of solar cells  11 . A second protection member is disposed on the back surfaces of solar cells  11 . A sealing member is provided between first protection member  12  and the second protection member. The sealing member seals solar cells 
     It should be noted that first protection member  12  may be made from a glass plate, a ceramic plate, a resin plate, or the like, for example. Second protection member may be made from a glass plate, a ceramic plate, a resin plate, a resin sheet, a resin sheet including a metal layer, or the like. The sealing member may be made of crosslinked resin such as ethylene vinyl acetate copolymers (EVA), or non-crosslinked resin such as polyolefin, for example. 
     Metal-made frame  20  surrounds the outer peripheries of module body  10 . The end portions of module body  10  are fitted into frame  20 . Frame  20  includes: a pair of long-side frame pieces  21  provided outside first and second long side parts  10   a,    10   b,  respectively; and a pair of short-side frame pieces  22  provided outside first and second short side parts  10   c,    10   d,  respectively. 
     Long-side frame pieces  21  are provided extending from one-side end portions to opposite-side end portions of long side parts  10   a,    10   b  in the x-axis direction, respectively. Short-side frame pieces  22  include support parts  221  and fixation parts  222 , respectively. Support parts  221  are provided extending from positions short of one-side end portions of short side parts  10   c,    10   d  by length A to positions short of opposite-side end portions of short side parts  10   c,    10   d  by length A in the x-axis direction, respectively. Fixation parts  222  extend from support parts  221  in the y-axis direction in a way that fixation parts  222  cover end portions of long-side frame pieces  21  in the x-axis direction, respectively. It should be noted that as illustrated in  FIG. 2 , length A is a total of: length B of long-side frame piece  21  in the y-axis direction by which long-side frame piece  21  is fitted into module body  10 ; and length C of cutout  22   g,  which is described later. 
       FIG. 3  is a diagram showing how long-side frame piece  21  and short-side frame piece  22  are connected together. As illustrated in  FIG. 3 , long-side frame piece  21  and fixation part  222  of neighboring short-side frame piece  22  are fixed to each other with first and second screws  23 ,  24  attached from short-side frame piece  22  to long-side frame piece  21 . 
     To begin with, descriptions are provided for the configuration of long-side frame piece  21 .  FIG. 4  is a schematic side view of the solar cell module viewed in an arrow IV direction of  FIG. 1 . Part of the end portion of long-side frame piece  21  in the x-axis direction is covered with fixation part  222  of short-side frame piece  22 . In  FIG. 4 , the part covered with fixation part  222  of long-side frame piece  21 , and module body  10 -side part of short-side frame piece  22  are indicated with broken lines for the purpose of explaining the structure.  FIG. 5  is a schematic exploded perspective view of the frame of an embodiment.  FIG. 6  is a schematic cross-sectional view of the long-side frame piece taken along the VI-VI line of  FIG. 1 . 
     As illustrated in  FIGS. 4 to 6 , long-side frame piece  21  includes cylindrical part  21   a,  extension part  21   h  and groove  21   m.  Cylindrical part  21   a,  extension part  21   h  and groove  21   m  are formed extending from the one-side to opposite-side end portions of long-side frame piece  21  in the x-axis direction. 
     Cylindrical part  21   a  includes inner sidewall part  21   b  outer sidewall part  21   c,  ceiling wall part  21   d  and bottom wall part  21   e.    
     Inner sidewall part  21   b  extends in the z-axis direction, and is located along a module body  10 -side portion of cylindrical part  21   a,  or along a y 1 -side portion of cylindrical part  21   a  in the y-axis direction. Outer sidewall part  21   c  extends in parallel with inner sidewall part  21   b,  and is located along an opposite portion of cylindrical part  21   a  from module body  10 , or along a y 2 -side portion of cylindrical part  21   a  in the y-axis direction. Ceiling wall part  21   d  extends in the y-axis direction, and connects a z 1 -side end portion of inner sidewall part  21   b  in the z-axis direction and a z 1 -side end portion of outer sidewall part  21   c  in the z-axis direction. Bottom wall part  21   e  extends in the y-axis direction, and connects a z 2 -side end portion of inner sidewall part  21   b  in the z-axis direction and a z 2 -side end portion of outer sidewall part  21   c  in the z-axis direction. 
     Through hole  21   a   1  is formed by inner sidewall part  21   b,  outer sidewall part  21   c,  ceiling wall part.  21   d  and bottom wall part  21   e.  Through hole  21   a   1  is formed extending from one-side to opposite-side end portions of long-side frame piece  21  in the x-axis direction. The cross section of through hole  21   a   1  on a plane defined by the y- and z-axes is shaped like a rectangle. 
     First screw hole  21   f  into which to insert first screw  23 , and second screw hole  21   g  into which to insert second screw  24  are provided inside cylindrical part  21   a.  First and second screw holes  21   f,    21   g  extend in the x-axis direction. First screw hole  21   f  is disposed at a position at which inner sidewall part  21   b  and ceiling wall part  21   d  intersect each other. Second screw hole  21   g  is disposed on inner sidewall part  21   b,  and on the z 2  side of first screw hole  21   f.  In other words, first and second screw holes  21   f,    21   g  are adjacently provided on the inner sidewall part  21   b.    
     It should be noted that: first and second screw holes  21   f,    21   g  are each shaped like a cylinder, which extends in the x-axis direction, and the side surface of which is partially opened. The opening directions of first and second screw holes  21   f,    21   g  are different from each other. In this respect, first screw hole  21   f  is opened in a direction between the y 2  and z 2  directions. Second screw hole  21   g  is opened in the y 2  direction. Since the side surface of each screw hole is opened like this it is possible to secure play for the alignment of the screw hole and the corresponding screw with each other. Furthermore, since the opening directions of the two screw holes are different from each other, the two screw holes are durable against contractions and stretches in different directions. 
     Extension part  21   h  is provided, projecting in the y 2  direction from a z 2 -side end portion of a y 2 -side wall surface of outer sidewall part  21   c.  The cross section of extension part  21   h  on a plane defined by the y- and z-axes is shaped like the letter L. Solar cell module  1  is fixed to a setting surface with the assistance of extension part  21   h.    
     Furthermore, outer sidewall part  21   c  is formed in a way that its z 2 -side portion  21   c   1  is thicker in wall thickness, or in y-direction thickness, than its z 1 -side portion  21   c   2 . This enhances the rigidity of frame  20 . 
     Groove  21   m  is formed by flange part  21   j,  ceiling wall part  21   d  of cylindrical part  21   a,  and connection part  21   k.  Flange part  21   j  extends in the y-axis direction, and is disposed away from ceiling wall part  21   d  of cylindrical part  21   a  by a distance in a z 1  direction. Connection part  21   k  connects a y 2 -side end portion of flange part  21   j  and a y 2 -side portion of ceiling wall part  21   d.  A z 2 -side portion of connection part  21   k  is connected to the z 1 -side end portion of outer sidewall part  21   c  of cylindrical part  21   a.  Groove  21   m  is formed by flange part  21   j,  ceiling wall part  21   d  and connection part  21   k,  as well as is shaped like the letter U, which is opened in the y 1  direction. First and second long side parts  10   a,    10   b  of module body  10  are fitted into grooves  21   m,  respectively. 
     Next, descriptions are provided for a configuration of short-side frame piece  22 .  FIG. 7  is a schematic side view of the short-side frame piece of an embodiment.  FIG. 8  is a schematic cross-sectional view of the short-side frame piece taken along the VIII-VIII line of  FIG. 7 . 
     As illustrated in  FIGS. 4, 5, 7 and 8 , short-side frame piece  22  is formed from plate-shaped part  22   a.  Fixation parts  222 , described above, are the two end portions of plate-shaped part  22   a.  in the y-axis direction. Openings  22   a   1 ,  22   a   2 , cutouts  22   b,  first and second ribs  22   c,    22   d,  groove  22   f,  and cutouts  22   g  are formed in plate-shaped part  22   a.    
     Openings  22   a   1 ,  22   a   2  are through holes formed in places short of the two end portions of plate-shaped part  22   a  in the y-axis direction by a predetermined distance. First and second screws  23 ,  24  are placed in openings  22   a   1 ,  22   a   2 . First screws  23  penetrate openings  22   a   1 , and are inserted into first screw holes  21   f.  Second screws  24  penetrate openings  22   a   2 , and are inserted into second screw holes  21   g.  Thereby, mutually adjacent long-side and short-side frame pieces  21 ,  22  are fixed to each other. 
     In long-side frame piece  21 , as described above, first and second screw holes  21   f,    21   g  are adjacently provided on the inner sidewall part  21   b  of cylindrical part  21   a.  For this reason, openings  22   a   1 ,  22   a   2  can be provided in places away from the two side end portions of plate-shaped part  22   a  in the y-axis direction. This inhibits a decrease in the rigidity of the portions of plate-shaped part  22   a,  which are provided with openings  22   a   1 ,  22   a   2 , compared with a case where openings  22   a   1 ,  22   a   2  are formed near the end portions of plate-shaped part  22   a  in the y-axis direction. 
     As illustrated in  FIGS. 4 and 5 , cutout  22   b  is formed where z 2 - and y 2 -side sides of plate-shaped part  22   a  intersect each other. The size of cutout  22   b  is adjusted such that, when short-side frame piece  22  is attached to long-side frame piece  21 , screw holes  21   f,    21   g  in through hole  21   a   1  are not exposed through cutout  22   b.  Because of cutout  22   b,  water that once enters through hole  21   a   1  is preferably discharged from through hole  21   a   1  via cutout  22   b.  Cutout  22   b  is provided in each corner portion of solar cell module  1 . This makes it easy to discharge water from through hole  21   a   1 . 
     As illustrated in  FIGS. 4, 7 and 8 , first and second ribs  22   c,    22   d  extend in parallel in the y-axis direction, and jut out in an x 1  direction from an x 1 -side wall surface of plate-shaped part  22   a.  In other words, first and second ribs  22   c,    22   d  jut out from a module body  10 -facing surface of plate-shaped part  22   a  toward module body  10 . First and second ribs  22   c,    22   d  are provided across plate-shaped part  22   a  in the y-axis direction, except for the end portions provided with openings  22   a   1 ,  22   a   2 . Second rib  22   d  is formed in a z 2 -side end portion of plate-shaped part  22   a.  First rib  22   c  is formed on the Z 1  side of second rib  22   d.  First and second ribs  22   c,    22   d  enhance the rigidity of plate-shaped part  22   a.    
     Groove  22   f  is formed by part of plate-shaped part  22   a,  first rib  22   c,  and flange part  22   e.  Flange part  22   e  extends along a z 1 -side end portion of plate-shaped part  22   a  in the y-axis direction. The length of flange part  22   e  in the y-axis direction is less than the length of first and second ribs  22   c,    22   d  in the y-axis direction. Flange part  22   e  juts out in the x 1  direction from the x 1 -side wall surface of plate-shaped part  22   a.  Groove  22   f  is formed by flange part  22   e,  plate-shaped part  22   a  and rib  22   c,  as well and is shaped like the letter U, which is opened in the x 1  direction. First and second short side parts  10   c,    10   d  of module body  10  are fitted into grooves  22   f,  respectively. Groove  22   f  corresponds to aforementioned support part  221  of short-side frame piece  22 . 
     In the z 1 -side end portion of plate-shaped part  22   a,  as illustrated in  FIGS. 4, 5 and 7 , cutouts  22   g  are formed between the two end portions of flange part  22   e  in the y-axis direction and the portions of plate-shaped part  22   a  which cover long-side frame pieces  21 , respectively. Cutouts  22   g  are formed in fixation parts  222  of short-side frame piece  22 , respectively. Cutouts  22   g  are each shaped like a recess. The base of the recess of each cutout  22   g  is flush with a light reception surface-side surface of module body  10 , or is situated at a level shifted from the light reception surface-side surface of module body  10  and even reaching the back surface of module body  10 . Thereby, water on module body  10  is preferably discharged via cutout  22   g.  Particularly since cutouts  22   g  are provided in all the corner portions of module body  10 , water on module body  10  is preferably discharged via cutouts  22   g.    
     In the case of solar cell module  1  in which frame pieces  21 ,  22  are produced by an extrusion formation method, cutouts  22   b,    22   g  and openings  22   a   1 ,  22   a   2 , which need to be processed by the extrusion formation method, are all included in short-side frame piece  22 . For this reason, long-side frame piece  21  can be formed by only a limited process, namely, end-surface cutting. This makes it easy to produce frame  20 , and makes it possible to produce frame  20  economically. 
     Furthermore, cylindrical part  21   a  is provided to long-side frame piece  21 . This enhances the rigidity of long-side frame piece  21 , which is relatively long and needs a higher rigidity. In contrast, no cylindrical part is provided to short-side frame piece  22 . This is because short-side frame piece  22  is relatively short and needs no higher rigidity. Accordingly, it is only inside long-side frame piece  21  including cylindrical part  21   a  that water is likely to stay, while water is unlikely to stay inside short-side frame piece  22 . Water which stays inside long-side frame pieces  21  is preferably discharged via cutouts  22   b  formed in the corners of frame  20 . 
     In addition, the extending direction of flange part  21   j  and the extending direction of extension part  21   h  are different from each other on a cross section (a y-z plane) perpendicular to the longitudinal direction of long-side frame piece  21 . This enhances the rigidity of long-side frame piece  21  more. 
     Furthermore, inside cylindrical part  21   a  (through hole  21   a   1 ), first screw hole  21   f  is disposed at the position at which inner sidewall part  21   b  and ceiling wall part  21   d  intersect each other. Second screw hole  21   g  is provided on inner sidewall part  21   b,  on the z 2  side of first screw hole  21   f,  and on the z 1  side of the z 2 -side end portion of the inner sidewall part  21   b.  This enhances the strength of long-side frame piece  21 . Moreover, because no screw hole is provided in a z 2 -side end portion of through hole  21   a   1 , it is easy to drain water. 
     In this way, embodiments above provide solar cell modules, which facilitate discharge of water from inside a frame. 
     The invention includes other embodiments in addition to the above-described embodiments without departing from the spirit of the invention. The embodiments are to be considered in all respects as illustrative, and not restrictive. The scope of the invention is indicated by the appended claims rather than by the foregoing description. Hence, all configurations including the meaning and range within equivalent arrangements of the claims are intended to be embraced in the invention.
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