Patent Publication Number: US-2022224240-A1

Title: Casing for electrical apparatus and power control apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of Japanese Patent Application No. 2018-203257 filed on Oct. 29, 2018, the entire contents of which are incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to a casing for an electrical apparatus and a power control apparatus. 
     BACKGROUND 
     An electric power control apparatus such as a power control apparatus (a power converter) in which an electrical apparatus that is connected to a solar cell and has a function of converting DC power from the solar cell into AC power is housed in a casing is becoming popular mainly for a domestic use. Because such a power control apparatus is often installed outdoors, the casing for housing the electrical apparatus needs to have a high waterproof property. 
     For example, PTL 1 set forth below discloses a casing that includes a casing body having an opening and a front cover for covering the opening of the casing body. The front cover has a structure in which a front cover front surface for covering the opening of the casing body and a front cover top surface for covering a top surface of the casing body are integrally formed such that an upper side of the casing has a double structure in which the front cover top surface and the top surface of the casing body overlap with each other, and thus improves the waterproof property. 
     CITATION LIST 
     Patent Literature 
     PTL 1: JP-A-2018-60828 
     SUMMARY 
     A casing for an electrical apparatus according to an embodiment of the present disclosure is a casing for an electrical apparatus that houses an electrical apparatus and includes: a casing body having an opening; a cover body that includes a flat plate-like cover portion having a rectangular shape and a curved cover portion continuous to one side of the flat plate-like cover portion, and is attached to the casing body to cover the opening; a sealing member that is arranged between the casing body and the flat plate-like cover portion and seals between the casing body and the flat plate-like cover portion; and a communication portion that is provided inside the curved cover portion in a manner extending along the one side of the flat plate-like cover portion and communicates with outside between the curved cover portion and the casing body. 
     Further, a power control apparatus according to an embodiment of the present disclosure includes any casing for an electrical apparatus according to the present disclosure and an electrical apparatuses housed in the casing for an electrical apparatus. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the accompanying drawings: 
         FIG. 1  is a perspective view of a power control apparatus according to an embodiment of the present disclosure; 
         FIG. 2  is an exploded perspective view of the power control apparatus illustrated in  FIG. 1 ; 
         FIG. 3  is a perspective view of a casing body illustrated in  FIG. 2 ; 
         FIG. 4  is a vertical cross-sectional view of portions of the power control apparatus illustrated in  FIG. 1  on a fourth wall side and a fifth wall side; 
         FIG. 5  is a perspective view of a cover body illustrated in  FIG. 2 ; 
         FIG. 6  is a perspective view of the power control apparatus illustrated in  FIG. 1  in a state in which the cover body and an electrical apparatus are removed; 
         FIG. 7  is a perspective view of a partition wall illustrated in  FIG. 6 ; 
         FIG. 8  is a cross-sectional view illustrating a communication portion provided inside a curved cover portion; 
         FIG. 9  is a plan view illustrating a communication structure of the communication portion for communicating with an outside on the fourth wall side of the casing body; and 
         FIG. 10  is a bottom view illustrating a communication structure of the communication portion for communicating with the outside on the fifth wall side of the casing body. 
     
    
    
     DETAILED DESCRIPTION 
     A conventional casing for a power control apparatus is required to have improved (aesthetic) design as well as a waterproof property described above. 
     An object of the present disclosure is to provide a casing for an electrical apparatus that has an improved design and ensures functionality, and a power control apparatus. 
     According to the embodiment of the present disclosure, a casing for an electrical apparatus that has an improved design and ensures functionality and a power control apparatus can be provided. 
     Hereinafter, an embodiment of the present disclosure will be illustrated in detail with reference to the drawings. 
     A power control apparatus  1  according to the present embodiment includes a casing  2  for an electrical apparatus and an electrical apparatus  3  housed in the casing  2  for an electrical apparatus, as illustrated in  FIG. 1 . 
     The electrical apparatus  3  schematically illustrated in  FIG. 1  is connected to, for example, a solar cell installed on a roof of a house and has a function of converting DC power generated by the solar cell into AC power and outputting the AC power to an electric system of the house. That is, the power control apparatus  1  is configured as a power control apparatus (a power converter) for a domestic use. 
     The power control apparatus  1  may have a configuration in which the casing  2  for an electrical apparatus houses, for example, a plurality of types of electrical apparatuses having different functions or configurations such as a fuel cell, a storage battery, a ventilation fan, or the like, in addition to the electrical apparatus  3  having the power conversion function as described above. As the storage battery mentioned above, for example, a lithium ion battery or a nickel hydrogen battery can be used. The casing  2  for an electrical apparatus can also house a member such as a heat insulating material or a cushioning material, in addition to the electrical apparatus  3 . Further, the electrical apparatus  3  housed in the casing  2  for an electrical apparatus is not limited to one having the power conversion function for the solar cell as described above and may be an electrical apparatus that has other functions or configurations such as, for example, a fuel cell, a transformer apparatus, or an apparatus having a function of supplying electric power to a commercial power system. 
     The power control apparatus  1  may be installed outdoors. In the present embodiment, the power control apparatus  1  is installed, for example, on an exterior wall of a house by using mounting brackets, a pedestal, or the like. 
     The power control apparatus  1  is not limited to be installed outdoors but may be installed in other places including indoors. 
     The casing  2  for an electrical apparatus includes a casing body  10 , a cover body  20 , a first partition wall  30 , a second partition wall  31 , a top cover  40 , and a bottom cover  50 , as illustrated in  FIG. 2 . 
     As illustrated in  FIG. 3 , the casing body  10  has a box shape including a first wall  11 , a second wall  12 , a third wall  13 , a fourth wall  14 , and a fifth wall  15 . In the present embodiment, the casing body  10  is a cast product made of aluminum alloy in which the first wall  11 , the second wall  12 , the third wall  13 , the fourth wall  14 , and the fifth wall  15  are integrally provided. The casing body  10  having the configuration and shape as described above can be easily manufactured at a high productively. 
     The casing body  10  is not limited to the cast product made of aluminum alloy described above and may be a cast product such as a cast iron product or other metal cast products. The casing body  10  is not limited to a cast metal product and may be a product made of another material such as, for example, an injection-molded product made of a synthetic resin material. Further, the casing body  10  may have a configuration in which the first wall  11 , the second wall  12 , the third wall  13 , the fourth wall  14 , and the fifth wall  15  are formed separately from one another and integrally connected to one another by means such as welding, bonding, fastening, or the like. 
     The first wall  11  includes a first side  11   a  and a second side  11   b  parallel to each other. The first wall  11  also includes a third side  11   c  and a fourth side  11   d  that are orthogonal to the first side  11   a  and the second side  11   b  and parallel to each other. As described above, the first wall  11  has a rectangular plate-like shape in appearance formed by the four sides  11   a  to  11   d.  In the present embodiment, the first wall  11  constitutes a rear surface of the casing body  10 . 
     The second wall  12  has an elongated rectangular plate-like shape and is continuous at a right angle to the first wall  11  on the first side  11   a.  The third wall  13  has an elongated rectangular plate-like shape in a manner similar to the second wall  12  and is continuous at a right angle to the first wall  11  on the second side  11   b  in a manner opposing the second wall  12 . In the present embodiment, the second wall  12  and the third wall  13  oppose each other in parallel and constitute respective side surfaces facing left and right sides of the casing body  10 . 
     The fourth wall  14  has an elongated plate-like shape and is continuous at a right angle to the third side  11   c  of the first wall  11  and, simultaneously, to upper sides of the second wall  12  and the third wall  13  located on the upper side in  FIG. 3 . The fourth wall  14  has a shape having a trapezoidal protruding portion that protrudes in a direction remote from the first wall  11  with respect to the second wall  12  and the third wall  13  and includes a surface of the protruding portion that is parallel to the first wall  11  and functions as an end surface  14   a  of the fourth wall  14  facing opposite from the first wall  11 . In the present embodiment, the fourth wall  14  constitutes a top surface of the casing body  10  that faces up. 
     The fifth wall  15  has an elongated plate-like shape having a trapezoidal protruding portion in a manner similar to the fourth wall  14  and is continuous at a right angle to the fourth side  11   d  of the first wall  11  in a manner opposing the fourth wall  14  and also to bottom sides of the second wall  12  and the third wall  13  located on a lower side in  FIG. 3 . A surface of the protruding portion of the fifth wall  15  parallel to the surface of the first wall  11  functions as an end surface  15   a  facing opposite from the first wall  11 . In the present embodiment, the fifth wall  15  constitutes a bottom surface of the casing body  10  that faces down. 
     As illustrated in  FIG. 4 , the casing body  10  includes a housing space  10   a  therein in which the electrical apparatus  3  is housed. A side of the casing body  10  opposing the first wall  11  forms an opening  10   b.  By removing the cover body  20  from the casing body  10  and communicating the opening  10   b  to the outside, the electrical apparatus  3  can be arranged in the housing space  10   a  through the opening  10   b.    
     As illustrated in  FIG. 5 , the cover body  20  has a U-shape in cross-section including a flat plate-like cover portion  21 , a first side surface cover portion  22  that covers the second wall  12 , a second side surface cover portion  23  that covers the third wall  13 , a first curved cover portion  24  continuous to the flat plate-like cover portion  21  and the first side surface cover portion  22 , and a second curved cover portion  25  continuous to the flat plate-like cover portion  21  and the second side surface cover portion  23 . 
     The cover body  20  is formed by, for example, performing sheet metal processing of a metal plate made of steel, aluminum alloy, or stainless steel. Thus, the cover body  20  having the above shape can be formed easily at low cost by a simple bending process. A plate thickness of the cover body  20  can be determined appropriately and may preferably be, for example, 0.3 mm to 3.5 mm. 
     The cover body  20  is not limited to one formed by performing sheet metal processing of a plate material and may have a structure in which the flat plate-like cover portion  21 , the first side surface cover portion  22 , the second side surface cover portion  23 , the first curved cover portion  24 , and the second curved cover portion  25  are formed separately and integrally connected to one another by means such as welding, adhesion, or fastening. Further, the cover body  20  is not limited to a metal product and may be a product made of another material such as an injection molded product made of a synthetic resin material. 
     The flat plate-like cover portion  21  has a first side  21   a  and a second side  21   b  that are parallel to the first side of the first wall  11  of the casing body  10 . The flat plate-like cover portion  21  also has a third side  21   c  and a fourth side  21   d  that are parallel to the third side  11   c  of the first wall  11 . Thus, the flat plate-like cover portion  21  has an exterior in a rectangular plate-like shape including the four sides  21   a  to  21   d.  In the present embodiment, the flat plate-like cover portion  21  constitutes a front cover portion that covers the opening  10   b  formed on the front surface of the casing body  10 . 
     The first curved cover portion  24  is integrally provided to the first side  21   a  of the flat plate-like cover portion  21 . The first curved cover portion  24  is curved at an angle of 90 degrees in an arc about a central axis parallel to the first side  21   a  from the first side  21   a  toward the first wall  11 . 
     The second curved cover portion  25  is integrally provided to the second side  21   b  of the flat plate-like cover portion  21 . The second curved cover portion  25  is curved at an angle of 90 degrees in an arc about a central axis parallel to the second side  21   b  from the second side  21   b  toward the first wall  11 . 
     The first side surface cover portion  22  has a rectangular plate-like shape parallel to the second wall  12  and is integrally provided to the first curved cover portion  24 . Similarly, the second side surface cover portion  23  has a rectangular plate-like shape parallel to the third wall  13  and is integrally provided to the second curved cover portion  25 . 
     Each of the first side surface cover portion  22  and the second side surface cover portion  23  is provided with two attaching holes  26  (note: one attaching hole  26  of the first side surface cover portion  22  is illustrated in the figure). On the other hand, each of the second wall  12  and the third wall  13  of the casing body  10  is provided with two screw holes  18  at locations on a side of the first wall  11  and close to the fourth wall  14  and the fifth wall  15 , as illustrated in  FIG. 3 . As illustrated in  FIG. 1 , the cover body  20  is attached to the casing body  10  by screws  4  inserted into the attaching holes  26  of the cover body  20  and the corresponding screw holes  18  of the casing body  10 . The cover body  20  attached to the casing body  10  covers the opening  10   b  of the casing body  10 . 
     As described above, because the cover body  20  has the first curved cover portion  24  and the second curved cover portion  25 , the cover body  20  has rounded corners and a good appearance. As a result, the casing  2  for an electrical apparatus that includes the cover body  20  having the above shape and the power control apparatus  1  can have a better (aesthetic) design than a casing in which the cover body  20  does not have the first curved cover portion  24  and the second curved cover portion  25 . 
     Respective radii of the first curved cover portion  24  and the second curved cover portion  25  that are curved in an arc may be, for example, 10 mm or more. This configuration can enable the shape with rounded corners formed by the first curved cover portion  24  and the second curved cover portion  25  to sufficiently impress a viewer. Thus, the cover body  20  and the power control apparatus  1  using the cover body  20  can have an improved (aesthetic) design. 
     Preferably, the respective radii of the first curved cover portion  24  and the second curved cover portion  25  that are curved in an arc are, for example, in a range of 20 to 80 mm. This configuration can enable the shape with the rounded corners formed by the first curved cover portion  24  and the second curved cover portion  25  to sufficiently impress a viewer. Thus, the cover body  20  and the power control apparatus  1  using the cover body  20  can have an improved (aesthetic) design. 
     In the present embodiment, because the cover body  20  has the U-shape in cross section including the flat plate-like cover portion  21 , the first side surface cover portion  22 , the second side surface cover portion  23 , the first curved cover portion  24 , and the second curved cover portion  25 , the cover body  20  has rounded corners across the flat plate-like cover portion  21  and thus an improved exterior. As a result, the cover body  20  having the above shape and the power control apparatus  1  using the cover body  20  can have a better (aesthetic) design than a cover body that does not have curved cover portions. 
     In the present embodiment, further, the first side surface cover portion  22  and the second side surface cover portion  23  cover the second wall  12  and the third wall  13  of the casing body  10 . This configuration can suppress the second wall  12  and the third wall  13  of the casing body  10  heated by heat generated by the electrical apparatus  3  from being directly touched by hands. 
     The fourth wall  14  of the casing body  10  is provided with a flashing portion  16 , as illustrated in  FIG. 3  and  FIG. 4 . The flashing portion  16  is formed as a wall that extends along the end surface  14   a  of the fourth wall  14  facing opposite from the first wall  11  and protrudes in a direction remote from the fifth wall  15  (upward in  FIG. 4 ) with respect to a surface  14   b  of the fourth wall  14  facing outside of the casing body  10 . The flashing portion  16  is integrally provided to the fourth wall  14  and a surface of the flashing portion  16  facing opposite from the first wall  11  constitutes the end surface  14   a  of the fourth wall  14 . 
     In a case in which the power control apparatus  1  is installed such that the surface  14   b  of the fourth wall  14  faces up and an extension direction of the first wall  11  is parallel to the vertical direction, the flashing portion  16  protrudes upward from the surface  14   b  serving as the top surface of the casing body  10  and thus can suppress water such as rainwater accumulated on the surface  14   b  from flowing toward the end surface  14   a.    
     As illustrated in  FIG. 4 , the surface  14   b  of the fourth wall  14  facing the outside of the casing body  10  is inclined in a manner gradually approaching the fifth wall  15  from a side of the flat plate-like cover portion  21  of the cover body  20  (a side of the end surface  14   a  of the fourth wall  14 ) toward the first wall  11 . As a result, in a case in which the power control apparatus  1  is installed such that the surface  14   b  of the fourth wall  14  faces up and the extension direction of the first wall  11  is parallel to the vertical direction, water such as rainwater accumulated on the surface  14   b  serving as the top surface of the casing body  10  can flow down the inclination in a direction remote from the end surface  14   a  of the fourth wall  14 . 
     An inclination angle α of the surface  14   b  can be set to an appropriate value. For example, the inclination angle α of the surface  14   b  can be set to an angle between 1 degree and 35 degrees with respect to a direction perpendicular to the extension direction of the first wall  11 . Such an angle enables effective flow of water such as rainwater in the direction remote from the end surface  14   a  of the fourth wall  14  without increasing a size of the casing body  10  due to the inclined surface  14   b.    
     The casing body  10  may also have a configuration in which a heat sink  17  is integrally provided to the surface  14   b  of the fourth wall  14  facing the outside of the casing body  10 . In the present embodiment, the heat sink  17  includes first heat sink portions  17   a  integrally provided to the flashing portion  16 . A partition wall portion  11   e  protruding from the surface  14   b  in a direction remote from the fifth wall  15  is integrally provided to the first wall  11 , and the heat sink  17  includes second heat sink portions  17   b  that are arranged being spaced apart from the first heat sink portion  17   a  and integrally provided to the partition wall portion  11   e.  Further, the heat sink  17  includes third heat sink portions  17   c  integrally provided to the partition wall portion  11   e  and an outer side surface of the first wall  11 . A plurality of the first heat sink portions  17   a,  the second heat sink portions  17   b,  and the third heat sink portions  17   c  are arranged side by side between the second wall  12  and the third wall  13 . Because the casing body  10  includes the heat sink  17  integrally provided thereto, the casing body  10  can effectively discharge heat generated by the electrical apparatus  3  housed in the housing space  10   a  to the outside. 
     As illustrated in  FIG. 3  and  FIG. 4 , the second wall  12  and the third wall  13  are integrally provided to respective partition wall portions  12   a  and  13   a  that protrude from the surface  14   b  in the direction remote from the fifth wall  15 . The partition wall portions  12   a  and  13   a  are provided with respective rectangular through holes  12   b  and  13   b  penetrating the partition wall portions  12   a  and  13   a  having respective one edge continuous to the surface  14   b.  The through holes  12   b  and  13   b  are continuous to the entire area of the surface  14   b  via a portion between the first heat sink portion  17   a  and the second heat sink portion  17   b  on the surface  14   b  of the fourth wall  14 . Thus, when water such as rainwater is accumulated on the surface  14   b  in a case in which the power control apparatus  1  is installed such that the fourth wall  14  of the casing body  10  faces up, the water can be discharged to outside of the second wall  12  or the third wall  13  through the through holes  12   b  and  13   b.    
     A plurality (two in the drawing) of vertical ribs  13   c  extending in a direction parallel to the first side  11   a  and the second side  11   b  and a plurality (five in the drawing) of horizontal ribs  13   d  orthogonal to the vertical ribs  13   c  may be provided on the outer surfaces of the second wall  12  and the third wall  13  facing the outside of the casing body  10 . Although the vertical ribs and horizontal ribs provided on the outer surface of the second wall  12  are not illustrated in  FIG. 3 , the vertical ribs and the horizontal ribs respectively similar to the vertical ribs  13   c  and the horizontal ribs  13   d  provided on the outer surface of the third wall  13  are provided on the outer surface of the second wall  12 . As a result, the second wall  12  and the third wall  13  can be made thinner and lighter while increasing the rigidity, and heat generated by the electrical apparatus  3  housed in the housing space  10   a  can be effectively dissipated through the second wall  12  and the third wall  13 . 
     A first sealing member  5  and a second sealing member  6  are provided between the casing body  10  and the flat plate-like cover portion  21  of the cover body  20 , as illustrated in  FIG. 4 . Both the first sealing member  5  and the second sealing member  6  have a waterproof function of sealing between the casing body  10  and the flat plate-like cover portion  21  to a degree to stop water such as rainwater from entering. 
     The end surface  14   a  of the fourth wall  14  is provided with a groove-shaped portion  14   c  that is recessed in a U-shape toward the first wall  11  and extends straight in parallel with the third side  11   c.  In the present embodiment, the groove-shaped portion  14   c  is provided to the flashing portion  16 . A bottom surface of the groove-shaped portion  14   c  facing opposite from the first wall  11  constitutes a part of the end surface  14   a  of the fourth wall  14 . 
     The first sealing member  5  is formed in the shape of a rod having a rectangular cross-section and a length similar to that of the first side  21   a  of the flat plate-like cover portion  21 . As illustrated in  FIG. 3 , the first sealing member  5  is arranged within the groove-shaped portion  14   c  in a manner extending parallel to the first side  21   a  of the flat plate-like cover portion  21 . In a state in which the cover body  20  is attached to the casing body  10  as illustrated in  FIG. 4 , the first sealing member  5  is tucked between the bottom surface of the groove-shaped portion  14   c  constituting a part of the end surface  14   a  of the fourth wall  14  of the casing body  10  and a portion of the flat plate-like cover portion  21  of the cover body  20  on a side of the first side  21   a.  As a result, the first sealing member  5  is elastically deformed at a predetermined ratio in a compression direction and seals between the end surface  14   a  of the fourth wall  14  and the flat plate-like cover portion  21 . 
     The end surface  15   a  of the fifth wall  15  is provided with a groove-shaped portion  15   b  that is recessed in a U-shape toward the first wall  11  and extends straight in parallel with the fourth side  11   d.  A bottom surface of the groove-shaped portion  15   b  facing opposite from the first wall  11  constitutes a part of the end surface  15   a  of the fifth wall  15 . 
     The second sealing member  6  is formed in the shape of a rod having a rectangular cross section and a length similar to that of the second side  21   b  of the flat plate-like cover portion  21 . As illustrated in  FIG. 3 , the second sealing member  6  is arranged within the groove-shaped portion  15   b  in a manner extending parallel to the second side  21   b  of the flat plate-like cover portion  21 . As illustrated in  FIG. 4 , in a state in which the cover body  20  is attached to the casing body  10 , the second sealing member  6  is tucked between the bottom surface of the groove-shaped portion  15   b  constituting a part of the end surface  15   a  of the fifth wall  15  of the casing body  10  and a portion of the flat plate-like cover portion  21  of the cover body  20  on a side of the first side  21   b.  As a result, the second sealing member  6  is elastically deformed at a predetermined ratio in a compression direction and seals between the end surface  15   a  of the fifth wall  15  and the flat plate-like cover portion  21 . 
     As described above, by providing the second sealing member  6  between the end surface  15   a  of the fifth wall  15  of the casing body  10  and the flat plate-like cover portion  21  of the cover body  20 , water such as rainwater can be suppressed from entering the housing space  10   a  inside the casing body  10  from between the end surface  15   a  of the fifth wall  15  of the casing body  10  and the flat plate-like cover portion  21  of the cover body  20 . 
     The first sealing member  5  and the second sealing member  6  described above may be formed from an elastic body made of synthetic rubber or elastomer. The first sealing member  5  and the second sealing member  6  may be formed from a rubber sponge which is a foam of ethylene propylene rubber. The first sealing member  5  and the second sealing member  6  may have a structure and material other than those described above. 
     Although in the present embodiment the first sealing member  5  and the second sealing member  6  are respectively arranged in the groove-shaped portions  14   c  and  15   b  that are respectively formed on the end surfaces  14   a  and  15   a,  the groove-shaped portions  14   c  and  15   b  do not need to be formed on the end surfaces  14   a  and  15   a,  and the first sealing member  5  and the second sealing member  6  may be respectively arranged between the end surface  14   a  and the flat plate-like cover portion  21  and between the end surface  15   a  and the flat plate-like cover portion  21 . Further, the respective cross-sectional shapes of the first sealing member  5  and the second sealing member  6  are not limited to the rectangle shapes and may be another shape such as a circular shape. 
     As illustrated in  FIG. 6 , the casing body  10  is provided with a first partition wall  30  and a second partition wall  31 . In the present embodiment, each of the first partition wall  30  and the second partition wall  31  is formed separately from the casing body  10  and the cover body  20  and fixedly attached the casing body  10  by screws  7 . 
     The first partition wall  30  is arranged on an end surface of the second wall  12  of the casing body  10  facing opposite from of the first wall  11 , in a manner continuous thereto. The first partition wall  30  is formed in a wall shape that is inclined with respect to the second wall  12  extending between the flat plate-like cover portion  21  of the cover body  20  and the first side surface cover portion  22 . 
     The second partition wall  31  is arranged on an end surface of the third wall  13  of the casing body  10  facing opposite from the first wall  11 , in a manner continuous thereto. The second partition wall  31  is formed in a wall shape that is inclined with respect to the third wall  13  extending between the flat plate-like cover portion  21  of the cover body  20  and the second side surface cover portion  23 . 
     Because the first partition wall  30  and the second partition wall  31  basically have the same shapes and attachment structures with respect to the casing body  10 , the second partition wall  31  will be described hereinafter. 
     As illustrated in  FIG. 7 , the second partition wall  31  includes a flat plate-like first surface portion  31   a  parallel to the third wall  13 , a flat plate-like second surface portion  31   b  parallel to the first wall  11 , and a third surface portion  31   c  that is formed in a flat plate-like shape inclined with respect to both the first surface portion  31   a  and the second surface portion  31   b  and integrally provided between the first surface portion  31   a  and the second surface portion  31   b.  Each of the second surface portion  31   b  and the third surface portion  31   c  is provided with two (four in total) through holes  31   d  through which the screws  7  are to be inserted. 
     Each of the first partition wall  30  and the second partition wall  31  is formed by performing sheet metal processing of a metal plate material made of steel, aluminum alloy, or stainless steel. Thus, the first partition wall  30  and the second partition wall  31  having the above shape can be formed easily at low cost. The first partition wall  30  and the second partition wall  31  are not limited to those formed by performing the sheet metal processing of the metal plate material and may be formed from other materials such as injection-molded product made of a synthetic resin material or by other methods. 
     The third surface portion  31   c  of the second partition wall  31  has a length corresponding to a distance between the fourth wall  14  and the fifth wall  15 , one longitudinal end that opposes an inclined surface between the end portion  14   a  of the trapezoidal protruding portion of the fourth wall  14  and the third wall  13  and the other longitudinal end that opposes an inclined surface between the end surface  15   a  of the trapezoidal protruding portion of the fifth wall  15  and the third wall  13 . Also, the second surface portion  31   b  has one end that opposes a part of the end surface  14   a  of the fourth wall  14  and the other end that opposes a part of the end surface  15   a  of the fifth wall  15 . Further, the first surface portion  31   a  opposes an end portion of the surface of the third wall  13  facing opposite from the second wall  12 . By attaching the first partition wall  30  and the second partition wall  31  having the above configurations to the casing body  10 , the opening  10   b  of the casing body  10  is defined by the end surface  14   a  of the fourth wall  14 , the end surface  15   a  of the fifth wall  15 , the first partition wall  30 , and the second partition wall  31 . Because second surface  30   b  of the first partition wall  30  and the second surface  31   b  of the second partition wall  31  are arranged in a manner to be respectively offset from the second wall  12  toward the third wall  13  and from the third wall  13  toward the second wall  12 , a width of the opening  10   b  defined by the end surface  14   a  of the fourth wall  14 , the end surface  15   a  of the fifth wall  15 , the first partition wall  30 , and the second partition wall  31  in a direction directing from the second wall  12  to the third wall  13  is narrower than a distance between the second wall  12  and the third wall  13 . 
     In the present embodiment, the first partition wall  30  and the second partition wall  31  are formed separately from the casing body  10  and the cover body  20  and attached to the casing body  10 . Thus, to arrange the electrical apparatus  3  in the housing space  10   a  within the casing body  10  via the opening  10   b,  by removing the first partition wall  30  and the second partition wall  31  from the casing body  10 , the opening  10   b  can be enlarged to a size corresponding to the distance between the second wall  12  and the third wall  13 . As a result, arrangement of the electrical apparatus  3  in the housing space  10   a  of the casing body  10  is facilitated. 
     As illustrated in  FIG. 3 , first auxiliary sealing members  32  extending over the end surface  14   a  and the inclined surface of the trapezoidal protruding portion are arranged on the fourth wall  14 . The first auxiliary sealing members  32  are tucked between the second surface portion  31   b  of the second partition wall  31  and the end surface  14   a  of the fourth wall  14  and also between the third surface portion  31   c  of the second partition wall  31  and the inclined surface of the protruding portion and thus has a waterproof function to a degree that stops water from entering between them. Also, second auxiliary sealing members  33  extending over the end surface  15   a  and the inclined surface of the trapezoidal protruding portion are arranged on the fifth wall  15 . The second auxiliary sealing members  33  are tucked between the second surface portion  31   b  of the second partition wall  31  and the end surface  15   a  of the fifth wall  15  and also between the third surface portion  31   c  of the second partition wall  31  and the inclined surface of the protruding portion and has a waterproof function to a degree that stops water from entering between them. Further, third auxiliary sealing members  34  are arranged on the end surface of the third wall  13  facing opposite from the first wall  11 . As illustrated in  FIG. 8 , the third auxiliary sealing members  34  are tucked between the third surface portion  31   c  of the second partition wall  31  and the end surface of the third wall  13  facing opposite from the first wall  11  and has a waterproof function to a degree that stops water from entering between them. As described above, the space between the second partition wall  31  and the casing body  10  is sealed by the first auxiliary sealing members  32 , the second auxiliary sealing members  33 , and the third auxiliary sealing members  34 . Thus, water such as rainwater is suppressed from entering the inside (the housing space  10   a ) of the casing body  10  from between the second partition wall  31  and the casing body  10 . 
     A partition wall sealing member  35  is arranged between the second surface portion  31   b  of the second partition wall  31  and the flat plate-like cover portion  21  of the cover body  20 , as illustrated in  FIG. 8 . The partition wall sealing member  35  is formed in a rod shape extending along the longitudinal direction of the second surface portion  31   b  of the second partition wall  31 , as illustrated in  FIG. 6 . The partition wall sealing members  35  has one end in the longitudinal direction that is connected to one end of the first sealing member  5  in a manner being abutted against the one end and also has the other end in the longitudinal direction that is connected to one end of the second sealing member  6  in a manner being abutted against the one end. The partition wall sealing member  35  is tucked between the second surface portion  31   b  and the flat plate-like cover portion  21  of the cover body  20  and has a waterproof function to a degree that stops water from entering between them. 
     As described above, the first sealing member  5 , the second sealing member  6 , and two partition wall sealing members  35  are arranged between the opening  10   b  of the casing body  10  and the flat plate-like cover portion  21  of the cover body  20  that covers the opening  10   b,  in a manner surrounding the opening  10   b.  Thus, water such as rainwater can be further suppressed from entering the casing body  10  from the opening. 
     As illustrated in  FIG. 8 , a communication portion  60  is arranged inside the first curved cover portion  24  of the cover body  20 . Similarly, a communication portion  60  is also arranged inside the second curved cover portion  25 . The communication portion  60  arranged inside the first curved cover portion  24  and the communication portion  60  arranged inside the second curved cover portion  25  have basically the same configuration, other than being symmetrical. Thus, the communication portion  60  arranged inside the second curved cover portion  25  will be described hereinafter. 
     The communication portion  60  is configured as a space extending in a direction along the second side  21   b  of the flat plate-like cover portion  21  inside the second curved cover portion  25 . As illustrated in  FIG. 9 , one end of the communication portion  60  on a side of the fourth wall  14  communicates with the outside of the casing  2  for an electrical apparatus in a gap  61  between an inner peripheral surface of the second curved cover portion  25  and the fourth wall  14  of the casing body  10 . As illustrated in  FIG. 10 , also, the other end of the communication portion  60  on a side of the fifth wall  15  communicates with the outside of the casing  2  for an electrical apparatus in a gap  62  between the inner peripheral surface of the second curved cover portion  25  and the fifth wall  15  of the casing body  10 . As described above, the communication portion  60  is formed to be a space that penetrates the casing  2  for an electrical apparatus from the side of the fourth wall  14  toward the side of the fifth wall  15  in a portion of the second curved cover portion  25 . 
     In the present embodiment, as illustrated in  FIG. 9 , a flange portion  14   d  having an arcuate outer peripheral surface is integrally provided between the end surface  14   a  of the fourth wall  14  and the third wall  13 , and the gap  61  is provided between an outer peripheral surface of the flange portion  14   d  and the inner peripheral surface of the second curved cover portion  25 . A radius of the arcuate outer peripheral surface of the flange portion  14   d  is smaller than a radius of the second curved cover portion  25 . As a result, the gap  61  has a shape in which a distance between the outer peripheral surface of the flange portion  14   d  and the inner peripheral surface of the second curved cover portion  25  gradually increases from a side of the end surface  14   a.    
     In the present embodiment, as illustrated in  FIG. 10 , a flange portion  15   c  having an arcuate outer peripheral surface is integrally provided between the end surface  15   a  of the fifth wall  15  and the third wall  13 , and the gap  62  is provided between the outer peripheral surface of the collar portion  15   c  and the inner peripheral surface of the second curved cover portion  25 . A radius of the arcuate outer peripheral surface of the flange portion  15   c  is smaller than a radius of the second curved cover portion  25 . As a result, the gap  62  has a shape in which a distance between the outer peripheral surface of the flange portion  15   c  and the inner peripheral surface of the second curved cover portion  25  gradually increases from a side of the end surface  15   a.    
     The communication portion  60  can function as a drainage channel extending in an up-down direction in a case in which the power control apparatus  1  is installed such that the surface  14   b  of the fourth wall  14  of the casing body  10  faces up. 
     As illustrated in  FIG. 1 , the power control apparatus  1  of the present embodiment having the above configuration is installed outdoors such that the surface  14   b  of the fourth wall  14  of the casing body  10  faces up. At this time, the power control apparatus  1  is installed such that the first wall  11  of the casing body  10  opposes the exterior wall of the house or the like. A wiring extending from the electrical apparatus  3  toward the electric power system inside the house and the solar cell is pulled out to the outside of the casing  2  for an electrical apparatus through holes formed on the fifth wall  15  and the bottom cover  50  of the casing body  10  that faces down. 
     In a case in which the power control apparatus  1  is installed outdoors such that the surface  14   b  of the fourth wall  14  faces up, there is a risk that water such as rainwater is accumulated on the surface  14   b.    
     However, in the power control apparatus  1  of the present embodiment, the casing  2  for an electrical apparatus includes the first sealing member  5  arranged between the end surface  14   a  of the fourth wall  14  of the casing body  10  and the flat plate-like cover portion  21  of the cover body  20  and thus can suppress water such as rainwater from entering between the end surface  14   a  of the fourth wall  14  of the casing body  10  and the flat plate-like cover portion  21  of the cover body  20 . Especially in a case in which the power control apparatus  1  is installed such that the surface  14   b  of the fourth wall  14  of the casing body  10  faces up, water such as rainwater may be accumulated on the surface  14   b.  However, water such as rainwater accumulated on the surface  14   b  can be suppressed from entering the inside (the housing space  10   a ) of the casing body  10  from between the end surface  14   a  of the fourth wall  14  of the casing body  10  and the flat plate-like cover portion  21  of the cover body  20 . 
     On the other hand, there may be a risk that, in spite of the first sealing member  5  provided between the end surface  14   a  and the flat plate-like cover portion  21 , water may remain accumulated between the end surface  14   a  and the flat plate-like cover portion  21 . 
     However, the casing  2  for an electrical apparatus of the present embodiment includes, on the inner sides of the first curved cover portion  24  and the second curved cover portion  25  that are continuous to the flat plate-like cover portion  21 , the communication portions  60  that extend in the direction along the side  21   a  and  21   b  of the flat plate-like cover portion  21  and communicate with the outside between the first curved cover portion  24  and the casing body  10  and between the second curved cover portion  25  and the casing body  10 . As a result, water accumulated between the end surface  14   a  and the flat plate-like cover portion  21  can be guided into the communication portion  60  from the gap  61  between the first curved cover portion  24 , the second curved cover portion  25 , and the flange portion  14   d  of the fourth wall  14  of the casing body  10  and can then flow downward along the communication portion  60  that functions as the drainage channel Further, water flowing downward along the communication portion  60  can be discharged outside from the gap  62  located between the first curved cover portion  24 , the second curved cover portion  25 , and the flange portion  15   c  of the fifth wall  15  of the casing body  10 . Thus, water accumulated between the end surface  14   a  and the flat plate-like cover portion  21  can be suppressed from entering the inside of the casing body  10  due to a capillary phenomenon or the like, and the waterproof property of the casing  2  for an electrical apparatus can be improved. 
     In the present embodiment, further, the flange portion  14   d  having the arcuate outer peripheral surface is provided on the fourth wall  14  such that the gaps  61  between the first curved cover portion  24  and the fourth wall  14  and between the second curved cover portion  25  and the fourth wall  14  have respective elongated slit shapes extending along the inner peripheral surfaces of the first curved cover portion  24  and the second curved cover portion  25 . As a result, water guided into the communication portion  60  from the gap  61  can flow along the inner peripheral surfaces of the first curved cover portion  24  and the second curved cover portion  25 , whereby the waterproof property of the casing  2  for an electrical apparatus can be further improved. 
     Here, in addition to the first sealing member  5  that seals the gap between the end surface  14   a  and the flat plate-like cover portion  21 , waterproof seals may be tucked between the first curved cover portion  24  and the flange portion  14   d  of the fourth wall  14  of the casing body  10  and between the second curved cover portion  25  and the flange portion  14   d  of the fourth wall  14  of the casing body  10  to seal between them. In this case, however, when the cover body  20  is fitted to the casing body  10 , each part of the waterproof seals is compressed in a direction directed from the flat plate-like cover portion  21  toward the end surface  14   a  while being not compressed in a direction perpendicular to the inner peripheral surfaces of the first curved cover portion  24  and the second curved cover portion  25 . As a result, there is a risk that compression ratios of the respective parts of the waterproof seals become uneven, causing wrinkles or the like in a portion under an insufficient compression and exhibiting insufficient waterproof property. 
     On the other hand, in the casing  2  for an electrical apparatus of the present embodiment, waterproof seals are not provided between the first curved cover portion  24  and the flange portion  14   d  of the fourth wall  14  of the casing body  10  and between the second curved cover portion  25  and the flange portion  14   d  of the fourth wall  14  of the casing body  10 , and water accumulated between the end surface  14   a  and the flat plate-like cover portion  21  is actively discharged to the outside through the communication portion  60 . Thus, the waterproof property of the casing  2  for an electrical apparatus can be improved. 
     The configuration described above can ensure the waterproof functions of the casing  2  for an electrical apparatus and the power control apparatus  1  and, by providing the first curved cover portion  24  and the second curved cover portion  25  to the cover body  20 , the (aesthetic) design of the casing  2  for an electrical apparatus and the power control apparatus  1  can be improved. 
     In the casing  2  for an electrical apparatus of the present embodiment, on the other hand, the first sealing member  5  is provided between the end surface  14   a  of the casing body  10  and the flat plate-like cover portion  21  of the cover body  20 , and the second sealing member  6  is provided between and the end surface  15   a  of the casing body  10  and the flat plate-like cover portion  21  of the cover body  20 . Further, the partition wall sealing members  35  are provided between the first partition wall  30  and the flat plate-like cover portion  21  and between the second partition wall  31  and the flat plate-like cover portion  21 . As a result, the first sealing member  5 , the second sealing member  6 , and the partition wall sealing members  35  can be entirely compressed in the direction perpendicular to the first wall  11 . Thus, the first sealing member  5 , the second sealing member  6 , and the partition wall sealing members  35  can be entirely compressed at a constant compressibility, and the opening  10   b  of the casing body  10  can be protected from water by the flat plate-like cover portion  21  of the cover body  20 . 
     In the casing  2  for an electrical apparatus of the present embodiment, further, the first auxiliary sealing members  32 , the second auxiliary sealing members  33 , and the third auxiliary sealing members  32  are provided between the first partition wall  30  and the casing body  10  and between the second partition wall  31  and the casing body  10 . All of the first auxiliary sealing members  32 , the second auxiliary sealing members  33 , and the third auxiliary sealing members  34  are tucked between the third surface portion  31   c  of the second partition wall and the surface of the casing body  10  parallel thereto and to be compressed. The same applies to the side of the first partition wall  30 . In other words, the first auxiliary sealing members  32 , the second auxiliary sealing members  33 , and the third auxiliary sealing members  34  are respectively compressed in one direction in which they are entirely inclined with respect to the direction perpendicular to the first wall  11 . Thus, the entire first auxiliary sealing members  32 , the second auxiliary sealing members  33 , and the third auxiliary sealing members  34  are compressed at a constant compression rate, whereby the gaps between the first partition wall  30  and the casing body  10  and between the second partition wall  31  and the casing body  10  can be further reliably sealed. Thus, water can be further reliably suppressed from entering from between the first partition wall  30  and the casing body  10  and between the second partition wall  31  and the casing body  10 . 
     In the present embodiment, because the first partition wall  30  and the second partition wall  31  are provided to the casing body  10 , the communication portion  60  can be separated from the inside (the housing space  10   a ) of the casing body  10  by the first partition wall  30  and the second partition wall  31 . As a result, water such as rainwater flowing in the communication portion  60  can be suppressed from entering the inside of the casing body  10 , whereby the waterproof properties of the casing  2  for an electrical apparatus and the power control apparatus  1  can be further improved. 
     In the present embodiment, the flashing portion  16  is provided on the fourth wall  14  of the casing body  10 , as described above. In a case in which the power control apparatus  1  is installed such that the surface  14   b  of the fourth wall  14  faces up and the extension direction of the first wall  11  is parallel to the vertical direction, the flashing portion  16  protrudes upward from the surface  14   b  serving as the top surface of the casing body  10 . Thus, water such as rainwater accumulated on the surface  14   b  is blocked by the flashing portion  16  and is suppressed from flowing toward the end surface  14   a.    
     In the present embodiment, as described above, because the flashing portion  16  that extends along the end surface  14   a  and protrudes in the direction remote from the fifth wall  15  is provided to the fourth wall  14 , in a case in which the power control apparatus  1  is installed such that the surface  14   b  of the fourth wall  14  faces up and the extension direction of the first wall  11  is parallel to the vertical direction, water such as rainwater accumulated on the surface  14   b  is suppressed from flowing toward the end surface  14   a.  As a result, water such as rainwater accumulated on the surface  14   b  is suppressed from reaching between the end surface  14   a  of the fourth wall  14  of the casing body  10  and the flat plate-like cover portion  21  of the cover body  20 , whereby the waterproof properties of the casing  2  for an electrical apparatus and the power control apparatus  1  can be further improved. 
     In the present embodiment, further, the surface  14   b  of the fourth wall  14  facing the outside of the casing body  10  is inclined in the manner to gradually approach the fifth wall  15  from the side of the flat plate-like cover portion  21  of the cover body  20  (the side of the end surface  14   a  of the fourth wall  14 ) toward the side of the first wall  11 , as described above. This configuration enables, in a case in which the power control apparatus  1  is installed such that the surface  14   b  of the fourth wall  14  faces up and the extension direction of the first wall  11  is parallel to the vertical direction, water such as rainwater accumulated on the surface  14   b  serving as the top surface of the casing body  10  to flow down the inclination in the direction remote from the end surface  14   a  of the fourth wall  14 , and also the water to be discharged to the outside through the holes  12   b  and  13   b  before being accumulated and reaching the end surface  14   a.  Water discharged through the through holes  12   b  and  13   b  flows downward through between the second wall  12  of the casing body  10  and the first side surface cover portion  22  of the cover body  20  between the third wall  13  of the casing body  10  and the second side surface cover portion  23  of the cover body  20  and then is discharged to the outside from the bottom end of the casing body  10  or the cover body  20 . As a result, water accumulated on the surface  14   b  can be further suppressed from reaching the end surface  14   a,  whereby the waterproof properties of the casing  2  for an electrical apparatus and the power control apparatus  1  can be further improved. 
     The top cover  40  is made of synthetic resin and attached to the casing body  10  to cover the end surface  14   a  of the fourth wall  14  facing the outside of the casing body  10  from above, as illustrated in  FIG. 1 . The top cover  40  is provided with a plurality of slit-shaped discharge holes  41  for discharging heat radiated through the heat sink  17  to the outside. Because the top cover  40  is attached to the casing body  10  as described above, the heat sink  17  or the surface  14   b  of the casing body  10  heated by heat from the electrical apparatus  3  can be suppressed from being directly touched by hand. 
     The bottom cover  50  is made of synthetic resin and attached to the casing body  10  to cover the bottom side of the fifth wall  15  as illustrated in  FIG. 6 . The bottom cover  50  can discharge water discharged from the gap  62  located on a bottom side of the communication portion  60  to the outside through the discharge holes formed at predetermined locations. Because the bottom cover  50  is attached to the casing body  10 , the fifth wall  15  of the casing body  10  heated by heat from the electrical apparatus  3  can be suppressed from being directly touched by hand. 
     The present disclosure is not limited to the above embodiments and can be modified in various manners without departing from the gist thereof. 
     For example, although in the above embodiments the cover body  20  includes the first curved cover portion  24  and the second curved cover portion  25 , the cover body  20  can include one curved cover portion alone. In this case, one partition wall alone corresponding to the one curved cover portion may be provided to the casing body  10 . 
     Although in the above embodiments the cover body  20  includes the first side surface cover portion  22  and the second side surface cover portion  23 , the first side surface cover portion  22  and the second side surface cover portion  23  can be omitted. 
     Although in the above embodiments the casing  2  for an electrical apparatus includes the first partition wall  30  and the second partition wall  31 , the casing  2  for an electrical apparatus may omit the first partition wall  30  and the second partition wall  31 . In this case, the communication portion  60  may be configured to function as a ventilation passage for a ventilation fan arranged in the housing space  10   a  of the casing body  10 . 
     Although in the above embodiments the first partition wall  30  and the second partition wall  31  are formed separately from the casing body  10  and the cover body  20  and attached to the casing body  10 , this is not restrictive. The first partition wall  30  and the second partition wall  31  may be integrally provided to the casing body  10 . The first partition wall  30  and the second partition wall  31  may be formed separately from the casing body  10  and the cover body  20  and attached to the cover body  20 . Further, the first partition wall  30  and the second partition wall  31  may be integrally provided to the cover body  20 . 
     Although in the above embodiments the casing body  10  includes the flashing portion  16 , the flashing portion  16  may be omitted. 
     Although in the above embodiments the surface  14   b  of the fourth wall  14  of the casing body  10  is inclined to gradually approach the fifth wall  15  from the side of the flat plate-like cover portion  21  toward the side of the first wall  11 , this is not restrictive. The surface  14   b  does not need to be inclined. 
     In the above embodiments the first sealing member  5  is provided between the end surface  14   a  of the fourth wall  14  of the casing body  10  and the flat plate-like cover portion  21  of the cover body  20 , and the second sealing member  6  is provided between the end surface  15   a  of the fifth wall  15  of the casing body  10  and the flat plate-like cover portion  21  of the cover body  20 . However, in a case in which the power control apparatus  1  is installed such that the fourth wall  14  of the casing body  10  faces up, the first sealing member  5  may can be provided between the end surface  14   a  of the fourth wall  14  of the casing body  10  and the flat-plate like cover portion  21  of the cover body  20 , without providing the second sealing member  6  between the end surface  15   a  of the  15  and the flat plate-like cover portion  21  of the cover body  20 . 
     Further, although in the above embodiments the power control apparatus  1  is installed such that the surface  14   b  of the fourth wall  14  faces up and the extension direction of the first wall  11  is parallel to the vertical direction, this is not restrictive. An installing orientation of the power control apparatus  1  can be changed in a various manners. 
     REFERENCE SIGNS LIST 
       1  power control apparatus 
       2  casing for electrical apparatus 
       3  electrical apparatus 
       4  screw 
       5  first sealing member 
       6  second sealing member 
       7  screw 
       10  casing body 
       10   a  housing space 
       10   b  opening 
       11  first wall 
       11   a  first side 
       11   b  second side 
       11   c  third side 
       11   d  fourth side 
       11   e  partition wall 
       12  second wall 
       12   a  partition wall 
       12   b  through hole 
       13  third wall 
       13   a  partition wall 
       13   b  trough hole 
       13   c  vertical rib 
       13   d  horizontal rib 
       14  fourth wall 
       14   a  end surface 
       14   b  surface 
       14   c  groove-shaped portion 
       14   d  flange portion 
       15  fifth wall 
       15   a  end surface 
       15   b  groove-shaped portion 
       15   c  flange portion 
       16  flashing portion 
       17  heat sink 
       17   a  first heat sink portion 
       17   b  second heat sink portion 
       17   c  third heat sink portion 
       18  screw hole 
       20  cover body 
       21  flat plate-like cover portion 
       21   a  first side 
       21   b  second side 
       21   c  third side 
       21   d  fourth side 
       22  first side surface cover portion 
       23  second side surface cover portion 
       24  first curved cover portion 
       25  second curved cover portion 
       26  attaching hole 
       30  first partition wall 
       30   b  second surface portion 
       31  second partition wall 
       31   a  first surface portion 
       31   b  second surface portion 
       31   c  third surface portion 
       31   d  through hole 
       32  first auxiliary sealing member 
       33  second auxiliary sealing member 
       34  third auxiliary sealing member 
       35  partition wall sealing member 
       40  top cover 
       50  bottom cover 
       60  communication portion 
       61  gap 
       62  gap 
     A inclination angle