Patent Publication Number: US-2022224094-A1

Title: Electrical connection box

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority of Japanese Patent Application No. JP 2021-002246 filed on Jan. 8, 2021, the contents of which are incorporated herein. 
     TECHNICAL FIELD 
     The present disclosure relates to an electrical connection box. 
     BACKGROUND 
     In an automobile, for example, in order to supply electric power from a battery to each of a plurality of in-vehicle devices, electric wires from the battery are connected to an electrical connection box (also referred to as a “junction box”), and electric wires are connected from the electrical connection box to the respective in-vehicle devices. The electrical connection box includes a case that houses a relay (relay box). JP 2016-25736A discloses such an electrical connection box. 
     SUMMARY 
     The electrical connection box has an upper case to which relays are attached and a lower case for covering bus bars connected to the relays from below.  FIG. 10  is a perspective view of relays  91  and bus bars  92  housed in the case of the electrical connection box. The bus bars  92  are connected to the terminals of the relays  91  by, for example, bolts  93 . In order to prevent electric shock, the electrical connection box requires a sealing structure that prevents a person from touching the connection portions between the relays  91  and the bus bars  92 . 
       FIG. 11  is a perspective view showing a conventional example of the sealing structure. Conventionally, a lower case  99  has sealing structure portions  98  that cover the connection portions (heads of the bolts  93 ) between the relays  91  and the bus bars  92 . The lower case  99  further has an engaging hook  97 , and due to the engaging hook  97  engaging with a portion of the upper case (not shown), the upper case and the lower case  99  form a single piece with each other. 
     In some cases, the lower case  99  is removed from the upper case when the operator handles the electrical connection box for maintenance or the like. Since the sealing structures  98  are part of the lower case  99 , if the lower case  99  comes off, there is a possibility that the connection portions between the bus bars  92  and the relays  91  will be unintentionally exposed. 
     In view of this, it is an object of the present disclosure to provide an electrical connection box capable of preventing the portion covering the connection portions between the relays and the bus bars from coming off. 
     An electrical connection box according to an aspect of the present disclosure is an electrical connection box including a relay, a bus bar connected to the relay, and a case including an attachment portion for the relay, the electrical connection box including a cover covering a connection portion between the relay and the bus bar, in which the cover includes a wall portion and an engaging portion that is provided at a part of the wall portion and prevents the cover from coming off by engaging with a part of the attachment portion, and the attachment portion includes a stopper portion for suppressing displacement of the part of the wall portion in a direction in which the engaging portion is disengaged. 
     According to the present disclosure, it is possible to prevent the portion covering the connection portions between the relays and the bus bars from coming off, and thus safety is high. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an electrical connection box according to the present embodiment. 
         FIG. 2  is a perspective view of a relay and bus bars. 
         FIG. 3  is a perspective view showing a state in which a relay located on the right side in  FIG. 1  is attached to an attachment portion. 
         FIG. 4  is a perspective view of the electrical connection box shown in  FIG. 1  with the covers removed. 
         FIG. 5  is a perspective view of the relay and the attachment portion shown in  FIG. 3 , with the cover removed. 
         FIG. 6  is a perspective view of a relay and bus bars. 
         FIG. 7  is a cross-sectional view of a cover and an attachment portion, and is a view of a state in which the cover is mounted. 
         FIG. 8  is a cross-sectional view of a cover and an attachment portion, and is a view of a state before mounting the cover. 
         FIG. 9  is a diagram illustrating second piece portions of the attachment portion. 
         FIG. 10  is a perspective view of relays and bus bars housed in a case of a conventional electrical connection box. 
         FIG. 11  is a perspective view showing a conventional example of a sealing structure. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Hereinafter, overviews of the embodiments of the present disclosure will be listed and described. 
     The electrical connection box of this embodiment is an electrical connection box including a relay, a bus bar connected to the relay, and a case including an attachment portion for the relay, the electrical connection box including a cover covering a connection portion between the relay and the bus bar, in which the cover includes a wall portion and an engaging portion that is provided at a part of the wall portion and prevents the cover from coming off by engaging with a part of the attachment portion, and the attachment portion includes a stopper portion for suppressing displacement of the part of the wall portion in a direction in which the engaging portion is disengaged. 
     According to the electrical connection box of the present embodiment, the engagement portion provided at the part of the wall portion of the cover prevents the cover covering the connection portion between the relay and the bus bar from coming off of the attachment portion of the case. The stopper portion of the attachment portion suppresses the displacement of the part of the wall portion in the direction in which the engaging portion is disengaged. For this reason, it is possible to prevent the cover from coming off, and thus safety is high. 
     Also, preferably, the stopper portion has a spring property for biasing the part of the wall portion in a direction opposite to the direction in which the engaging portion is disengaged. 
     In this case, if, in a state in which a relay with a bus bar is installed at the attachment portion of the case, the cover is attached to the connection portion between the relay and the bus bar, the stopper portion can elastically deform even when pushed by the wall portion of the cover, and thus attachment is easy. Then, once the cover is attached, the stopper portion can suppress the displacement of the part of the wall portion in the direction in which the engaging portion is disengaged, and can prevent the cover from coming off. 
     Also, preferably, the case includes a first case including the attachment portion, and a second case that covers at least a part of the attachment portion of the first case and is configured to form a single piece with the first case, and the cover includes, on the second case side, an opening through which the bus bar is passed between the relay and the cover. 
     In this case, the bus bar can be arranged pulled out from the opening of the cover. The bus bar pulled out from the opening is stored between the first case and the second case. The bus bar pulled out from the opening can be arranged bent toward the relay as-is, or arranged bent to the opposite side. That is, the degree of freedom in the arrangement (routing) of the bus bars is improved. 
     Also, preferably, the attachment portion includes a first piece portion and a second piece portion that sandwich the wall portion, the engaging portion is formed on the first piece portion side of the wall portion, an engaged portion with which the engaging portion engages is formed on the first piece portion, and the second piece portion includes the stopper portion. 
     In this case, the cover is attached such that the wall portion is sandwiched between the first piece portion and the second piece portion of the attachment portion. When the cover is attached in this way, the engaging portion engages with the engaged portion of the first piece portion, and the stopper portion of the second piece portion suppresses displacement of the part of the wall portion in the direction in which the engaging portion disengages. That is, if the cover is attached, the function of the engaging portion and the stopper portion for preventing the cover from coming off is established. 
     Also, preferably, the engaging portion is constituted by a hook that protrudes from the wall portion, and the engaged portion is constituted by a hole that passes through the first piece portion. 
     In this case, it is easy to visually confirm that the engaging portion (hook) is engaged with the engaged portion (hole), and thus the safety of the cover increases. 
     Hereinafter, the details of the embodiments of the present disclosure will be described with reference to the drawings. Note that at least some of the embodiments described below may also be combined as appropriate. 
     The electrical connection box  10  (see  FIG. 1 ) of the present embodiment is mounted in, for example, an automobile, and is used to supply electric power from an in-vehicle battery to each of a plurality of in-vehicle devices, although this is not shown in the drawings. That is, electric wires from the in-vehicle battery are connected to the electrical connection box  10 , and the electric wires are respectively connected to the in-vehicle devices from the electrical connection box  10 . 
     Overall Configuration of Electrical Connection Box  10   
       FIG. 1  is a perspective view of the electrical connection box  10  according to the present embodiment.  FIG. 2  is a perspective view of a relay  11  and bus bars  15 .  FIG. 2  also shows a cover  23 , which will be described later. The electrical connection box  10  includes a relay  11 , bus bars  15  connected to the relay  11 , and a case  16  to which the relay  11  with the bus bars  15  is attached. The electrical connection box  10  has a plurality of relays  11 . In  FIG. 1 , two relays  11  are provided in the case  16 , but the number of relays  11  is not limited. The relay  11  of the present embodiment is a high-voltage relay, and the electrical connection box  10  is a high-voltage electrical connection box. 
     Up, down, front, rear, left, and right are defined in relation to the electrical connection box  10  of the present disclosure. The case  16  has a box shape that is flat overall, although it includes recesses and protrusions. The flattened direction, that is, the direction in which the thickness is less, is defined as the vertical direction. The relay  11  is fitted and attached from one side of the case  16  (the upper side in  FIG. 1 ). The side on which the relay  11  is fitted is defined as “the upper side”. Also, the direction along a long side L 1  of the case  16  is defined as the left-right direction, and the direction along a short side L 2  of the case  16  is defined as the front-rear direction. Each drawing shows XYZ orthogonal coordinates. The Z direction is the direction from the bottom to the top (vertical direction), the Y direction is the front-rear direction (the direction from the front to the rear), and the X direction is the left-right direction (the direction from left to right). 
       FIG. 2  shows the relay  11  on the right side of the electrical connection box  10  shown in  FIG. 1 . The relay  11  is formed as a relay box having a box body  12 , and the relay main body is housed in the box body  12 . Terminals (fastening portions)  13  to which the bus bars  15  are connected are provided on the outer surface of the box body  12 . The terminals  13  are provided on one of the front, rear, left, and right side surfaces of the box body  12  of the relay  11 . In the case of the relay  11  shown in  FIG. 2 , the terminal  13  is provided on the front side surface of the box body  12 . The bus bars  15  are attached to the terminals  13  by bolts  17 . Two buses  15  are connected to one relay  11 . The portions where the bus bars  15  are connected to the terminals  13  by the bolts  17  are referred to as “connection portions  18 ”. 
     In  FIG. 1 , the case  16  has attachment portions  20  for attaching the relays  11 . Although not shown in the drawing, the case  16  has connection portions for cables for connecting to each of a plurality of in-vehicle devices.  FIG. 3  is a perspective view showing a state in which the relay  11  located on the right side in  FIG. 1  is attached to the attachment portion  20 , and a part of the case  16  is shown as a cross section. The case  16  is made of resin, and in the present embodiment, the case  16  has a first case  21  and a second case  22 . The first case  21  has the above-described attachment portions  20 . The attachment portion  20  is a portion having a recessed shape in which the relay  11  is fitted in and mounted from above the case  16  (first case  21 ). The attachment portion  20  is a portion that is molded at the same time when the first case  21  is molded (injection molded) with resin, and is a part of the first case  21 . The second case  22  is separate from the first case  21  and has a plate shape. 
     The attachment portion  20  is open on the upper side, but the first case  21  is open on the lower side overall. The second case  22  functions as a lid (bottom plate) that closes the opening on the lower side of the first case  21 . The first case  21  is also called the upper case, and the second case  22  is also called the lower case. A flat plate portion  45  included in the first case  21  covers the bus bars  15  extending from the relays  11  attached to the attachment portions  20 , from above. 
     The second case  22  covers at least a part of the attachment portions  20  of the first case  21  from below, and forms a single piece with the first case  21 . More specifically, the second case  22  covers the bus bars  15  extending from the relays  11  attached to the attachment portions  20 , from below, and forms a single piece with the first case  21 . The second case  22  is detachably attached to the first case  21 . 
     As described above, the case  16  has a first case  21  that has the attachment portions  20  and a second case  22 . 
     As shown in  FIGS. 1 and 3 , the electrical connection box  10  includes covers  23  that cover the connection portions  18  between the relays  11  and the bus bars  15 .  FIGS. 1 and 3  show a state in which the covers  23  are mounted on the case  16 , and  FIGS. 4 and 5  show a state before the covers  23  are mounted (a state in which the covers  23  are removed).  FIG. 2  shows a state before the connection portions  18  are covered by the cover  23 , and  FIG. 6  shows a state in which the connection portions  18  are covered by the cover  23 . The covers  23  are made of an insulating member, and are made of resin in this embodiment. The covers  23  are separate components from the case  16 , and are attached close to the respective relays  11  with the bus bars  15  mounted in the attachment portions  20  from above. 
     In  FIG. 4 , the attachment portion  20  and the cover  23  for the relay  11  on the right side and the attachment portion  20  and the cover  23  for the relay  11  on the left side have different attachment directions, but have the same configuration. The cover  23  on the right side will be described below. 
     The cover  23  includes a front wall portion  24  that covers a front side surface  12   a  of the relay  11  (box body  12 ) on which the connection portions  18  are located, two side wall portions  25  that are provided extending from the left and right sides of the front wall portion  24  toward the relay  11  (box body  12 ) side, and an upper wall portion  26  that covers the space formed between the front wall portion  24  and the two side wall portions  25  from above. The connection portions  18  are housed in the space in a state in which the cover  23  is attached to a specified position of the attachment portion  20  (hereinafter referred to as “mounted state”). Also, in the mounted state, openings  27  (see  FIG. 6 ) that open downward are formed between the cover  23  and the relay  11 . The openings  27  are open toward the second case  22  side, and the bus bars  15  are pulled out from the openings  27 . That is, the cover  23  includes, on the second case  22  side, openings  27  through which the bus bars  15  are passed between the relay  11  and the cover  23 . 
     Regarding the Attachment Structure of the Cover  23   
     As shown in  FIGS. 2 and 6 , the cover  23  has the front wall portion  24  for covering the connection portions  18  as described above. The cover  23  has engaging portions  28 , and each engaging portion  28  is provided on a part of the front wall portion  24 . As will be described later, engaged portions  29  (see  FIGS. 7 and 8 ) with which the engaging portions  28  engage are formed on a first piece portion  41  of the attachment portion  20 .  FIGS. 7 and 8  are cross-sectional views of the cover  23  and the attachment portion  20 .  FIG. 7  shows the state in which the cover  23  is mounted, and  FIG. 8  shows the state before the cover  23  is mounted. 
     The engaging portion  28  is constituted by a hook  28   a  protruding from the front wall portion  24 . The hook  28   a  has an upper locking surface  31  and an inclined surface  32  provided below the locking surface  31 . The locking surface  31  forms the upper surface of the hook  28   a  and is a surface extending along a virtual plane (X-Y plane) orthogonal to the vertical direction. The inclined surface  32  is a surface that is inclined with respect to a virtual plane (X-Z plane) in the vertical direction, and is a surface that approaches the front wall portion  24  side from the top to the bottom. 
       FIG. 3  shows a state in which the cover  23  is mounted, and  FIG. 5  shows a state before mounting. As shown in  FIGS. 3, 5, 7, and 8 , the attachment portion  20  of the first case  21  includes the first piece portion  41  and a second piece portion  42  that sandwich the front wall portion  24  of the cover  23  in the front-rear direction. The first piece portion  41  and the second piece portion  42  are portions that are molded at the same time when the first case  21  is molded, and are a part and another part of the attachment portion  20 . In one attachment portion  20  for one relay  11 , two left and right first piece portions  41  and two left and right second piece portions  42  are provided. 
     In  FIG. 5 , the first piece portions  41  are each a wall-shaped portion that is provided so as to extend upward from the flat plate portion  45  of the first case  21 . The flat plate portion  45  is a portion forming the upper surface of the first case  21 , and covers the bus bars  15  from above. The first piece portions  41  are continuous with respective side plate portions  46  that cover the relay  11  from the left and right sides. Each side plate portion  46  is also a wall-shaped portion, is provided extending upward from the flat plate portion  45 , and is included in the attachment portion  20 . 
     The engaged portion  29  with which the engaging portion  28  composed of the hook  28   a  engages is formed on the first piece portion  41 . In the present embodiment, the engaged portion  29  is composed of a hole  29   a  passing through the first piece portion  41 . As described above (see  FIG. 3 ), the hook  28   a  is formed on the first piece portion  41  side of the front wall portion  24  of the cover  23 . 
     With the cover  23  mounted (e.g., see  FIG. 3 ), that is, in a state in which the cover  23  is located between the relay  11  and the first piece portions  41  and is mounted at a defined position, the hooks  28   a  are respectively engaged with the holes  29   a  of the first piece portions  41 . As a result, the cover  23  cannot be displaced upward and is attached to the attachment portion  20 . More specifically, as shown in  FIG. 7 , in the mounted state, the locking surface  31  on the upper side of the hook  28   a  comes into contact with the upper surface of the hole  29   a , and the cover  23  cannot be displaced upward. Note that in the state where the cover  23  is mounted, a part of the cover  23  (e.g., the upper wall portion  26 ) comes into contact with a part of the attachment portion  20  (first piece portion  41 ) from above. Accordingly, the cover  23  is in the mounted state and cannot be displaced in the vertical direction. 
     In this manner, the engaging portions  28  (hooks  28   a ) of the cover  23  prevent the cover  23  from coming off by engaging with a part of the attachment portion  20  (the holes  29   a  of the first piece portions  41 ). 
     When a change is made from the state before the cover  23  is mounted shown in  FIG. 8  to the mounted state shown in  FIG. 7 , the hook  28   a  moves downward while being in contact with the first piece portion  41 . At this time, one or both of the front wall portion  24  and the first piece portion  41  of the cover  23  can be gradually elastically deformed by the inclined surface  32  of the hook  28   a , and the mounting of the cover  23  is not hindered. That is, the inclined surface  32  of the hook  28   a  functions as a guide used when the cover  23  is mounted. When the hook  28   a  reaches the hole  29   a , the elastic deformation is eliminated and the hook  28   a  engages with the hole  29   a.    
     Here, in the case of the configuration of the hook  28   a  of the cover  23  and the hole  29   a  of the first piece portion  41  as described above, there is a possibility that the hole  29   a  and the hook  28   a  will be disengaged when the hook  28   a  engaged with the hole  29   a  is forcibly pushed toward the relay  11  side together with the part of the front wall portion  24 . That is, the direction in which the hook  28   a  and the part of the front wall portion  24  on which the hook  28   a  is formed are pushed toward the relay  11  side is the direction in which the engaging portion  28  is disengaged. This direction is indicated by an arrow P in  FIG. 7 . 
     In view of this, the attachment portion  20  has a stopper portion  30  that suppresses displacement (deformation) of the part of the front wall portion  24  in the direction in which the engaging portion  28  is disengaged. Hereinafter, the stopper portion  30  will be described. 
       FIG. 9  is a diagram illustrating the second piece portions  42  included in the attachment portion  20 . Note that  FIG. 9  shows the relay  11  attached to the attachment portion  20 , but the bus bars  15  are omitted. The second piece portion  42  is a columnar portion that is provided extending upward from a part (lower portion)  47  of the first case  21  at a position toward the relay  11  side with respect to the first piece portion  41 . 
     The second piece portion  42  has the above-described stopper portion  30 . A specific configuration thereof will be described. The second piece portion  42  is a pair of column portions  48 ,  48  that are provided extending upward from a part  47  of the first case  21 , a connecting portion  49  connecting these column portions  48 ,  48 , on the upper side, and a beam portion  50  that is cantilevered from the connecting portion  49  and is provided extending to the above-described part  47  side, which is the lower side. This beam portion  50  functions as the stopper portion  30 . 
     With the cover  23  attached as shown in  FIG. 7 , a tip portion  50   a  of the beam portion  50  comes into contact with the rear surface of the part of the front wall portion  24 . As a result, the beam portion  50  suppresses the displacement (deformation) of the part of the front wall portion  24  in the direction in which the engagement portion  28  is disengaged (arrow P direction). Furthermore, in a state in which the tip portion  50   a  of the beam portion  50  is in contact with the front wall portion  24 , the beam portion  50  is in a state of being elastically deformed toward the relay  11  side. That is, the beam portion  50  that functions as the stopper portion  30  has a spring property for biasing the part of the front wall portion  24  in the direction opposite to the direction in which the engaging portion  28  is disengaged (the direction opposite to the arrow P). 
     Note that in the present embodiment, the stopper portion  30  is constituted by the cantilever-shaped beam portion  50 , but the stopper portion  30  may also have another configuration and need not have an active spring property. For example, the beam portion  50  need not be elastically deformed in a state where the tip portion  50   a  of the beam portion  50  is close to (or in contact with) the front wall portion  24 . For example, it is also possible to use a configuration in which, when the part of the front wall portion  24  is displaced to the relay  11  side by an external force, the part of the front wall portion  24  comes into contact with the beam portion  50 , and the contact causes the beam portion  50  to restrict the displacement of the part of the front wall portion  24 . That is, the stopper portion  30  may have a function of suppressing displacement (deformation) of the part of the front wall portion  24  in the direction in which the engaging portion  28  is disengaged (the direction of arrow P). With such a stopper portion  30 , it is possible to prevent the engagement between the hole  29   a  and the hook  28   a  from being disengaged unless the task is performed forcibly using a tool or the like. 
     Regarding Electrical Connection Box  10  of the Present Embodiment 
     As described above, the electrical connection box  10  of the present embodiment includes the relays  11 , the bus bars  15  connected to the terminals  13  of the relays  11 , the case  16  having the attachment portions  20  for the relays  11 , and the covers  23 . The cover  23  covers the connection portions  18  between the relay  11  and the bus bars  15 . The cover  23  has the front wall portion  24  for covering the connecting portions  18 , and the engaging portions  28  each provided at a part of the front wall portion  24 . The engaging portion  28  prevents the cover  23  from coming off by engaging with a part of the attachment portion  20 . Also, the attachment portion  20  has a stopper portion  30  that suppresses displacement of the part of the front wall portion  24  in the direction in which the engaging portion  28  is disengaged. 
     According to the electrical connection box  10  of the present embodiment, the engaging portions  28  that are each provided on the part of the front wall portion  24  of the cover  23  prevent the cover  23  that covers the connection portions  18  between the relay  11  and the bus bars  15  from coming off of the attachment portion  20  of the case  16 . The stopper portion  30  of the attachment portion  20  suppresses displacement of the part of the front wall portion  24  in the direction in which the engaging portion  28  is disengaged. For this reason, even if the first case  21  and the second case  22  are separated from each other, the cover  23  is kept in a state of being mounted on the attachment portion  20 . Also, according to the stopper portion  30 , the cover  23  can be prevented from coming off unless it is forcibly removed with a tool or the like, and a highly safe electrical connection box  10  can be obtained. 
     Also, in order to change from the state shown in  FIG. 8  to the mounted state shown in  FIG. 7 , the relay  11  with the bus bars  15  is installed in the attachment portion  20  of the case  16 , and when the cover  23  is attached to the connection portions  18  between the relay  11  and the bus bars  15  from above, the stopper portion  30  is pushed by the front wall portion  24  of the cover  23 . In view of this, in the present embodiment, the stopper portion  30  has a spring property for biasing the part of the front wall portion  24  in the direction opposite to the direction in which the engaging portion  28  is disengaged. According to this configuration, when the cover  23  is attached, the stopper portion  30  may be pushed by the front wall portion  24  of the cover  23 , but even in this case, the stopper portion  30  can be elastically deformed, and the cover  23  is easily attached. Then, once the cover  23  is attached, the stopper portion  30  can suppress displacement of the part of the front wall portion  24  in the direction in which the engaging portion  28  is disengaged, and can even more effectively prevent the cover  23  from coming off. 
     As shown in  FIGS. 7 and 8 , the attachment portion  20  has a first piece portion  41  and a second piece portion  42  that sandwich the front wall portion  24  in the front-rear direction. The engaging portion  28  is formed on the first piece portion  41  side of the front wall portion  24  of the cover  23 . The engaged portion  29  with which the engaging portion  28  engages is formed in the first piece portion  41 , and the second piece portion  42  has the stopper portion  30 . According to this configuration, the cover  23  is attached such that the front wall portion  24  thereof is sandwiched between the first piece portion  41  and the second piece portion  42 . When the cover  23  is attached in this way, the engaging portion  28  engages with the engaged portion  29  of the first piece portion  41 , and the stopper portion  30  of the second piece portion  42  suppresses displacement of the part of the front wall portion  24  in the direction in which the engaging portion  28  is disengaged. That is, if the cover  23  is attached, the function of the engaging portion  28  and the stopper portion  30  for preventing the cover  23  from coming off is established. 
     The engaging portion  28  is constituted by the hook  28   a  protruding from the front wall portion  24 , and the engaged portion  29  is constituted by the hole  29   a  passing through the first piece portion  41 . With this configuration, it is easy for an operator to visually confirm that the engaging portion  28  (hook  28   a ) is engaged with the engaged portion  29  (hole  29   a ), and the safety of the cover  23  is increased. 
     The case  16  has the first case  21  including the attachment portion  20  and the second case  22 , which is detachable from the first case  21 . The second case  22  covers at least a part of the attachment portion  20  of the first case  21  and forms a single piece with the first case  21 . Also, as shown in  FIG. 6 , the cover  23  includes, on the second case  22  side, an opening  27  through which the bus bars  15  are passed between the relay  11  and the cover  23 . 
     With this configuration, the bus bar  15  can be arranged pulled out from the opening  27  of the cover  23 . The bus bar  15  pulled out from the opening  27  is stored between the first case  21  and the second case  22 . The bus bar  15  shown on the right side of  FIG. 6  pulled out from the opening  27  can be arranged bent to the relay  11  side, which is the rear side, as-is, and the bus bar  15  shown on the left side of  FIG. 6  can be arranged bent to the opposite side, that is, the front side. That is, the degree of freedom in the arrangement (routing) of the bus bars  15  is improved. 
     In contrast to this, in the case of the conventional example shown in  FIG. 11 , the sealing structure portions  98  that cover the connection portions (heads of the bolts  93 ) between the relays  91  and the bus bars  92  form a single piece with the lower case  99 , and are each provided extending upward from a portion of the lower case  99 . For this reason, in the conventional example, as shown in  FIG. 10 , it is necessary to arrange all of the bus bars  92  bent to the relay  91  side, which is the rear side, such that the bus bars  92  do not interfere with the sealing structure portions  98 , and thus the degree of freedom in the arrangement (routing) of the bus bars  92  is low. 
     Other Configurations 
     The cover  23  need only be configured to cover at least the connection portions  18  between the relay  11  and the bus bars  15 , and may have a shape other than the mode shown in the drawings. The case  16  and the like may also have a shape other than the mode shown in the drawings. 
     The above-described embodiments are exemplary in all respects and not limiting. The scope of rights of the present invention is indicated not by the above-described embodiments, but by the scope of the claims, and encompasses all modifications within the range of equivalency to the configurations described in the scope of the claims.