Patent Publication Number: US-2023163583-A1

Title: Electrical junction box

Description:
TECHNICAL FIELD 
     The present disclosure relates to an electrical junction box. 
     The present application claims the benefit of priority based on Japanese Patent Application No. 2020-028502 filed Feb. 21, 2020, the entire content of which is hereby incorporated by reference. 
     BACKGROUND ART 
     Conventionally, vehicular electrical junction boxes for electrically connecting a battery and various electrical components have become widely spread. Many vehicles are provided with an electrical junction box that is disposed between a power supply and electrical components to supply power to them. In an electrical junction box, a housing houses components such as a substrate, busbars, and fuses. 
     Patent Document 1 discloses an electrical junction box that includes a busbar and a current sensor for detecting an electric current flowing through the busbar, and in which a chamber for housing the current sensor has a checking window through which a part of the current sensor is exposed, so that it is possible to check, through the checking window, whether or not the current sensor is housed. 
     CITATION LIST 
     Patent Document 
     Patent Document 1: JP 2009-100574A 
     SUMMARY OF INVENTION 
     An electrical junction box according to an embodiment of the present disclosure relates to an electrical junction box including a housing that houses a substrate on which a fuse is mounted, wherein the housing has a checking window for checking whether or not the fuse has been blown out. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a perspective view illustrating an outer appearance of an electrical junction box according to Embodiment 1. 
         FIG.  2    is a perspective view illustrating a state of the electrical junction box according to Embodiment 1 where an upper case part is removed. 
         FIG.  3    is a perspective view illustrating a substrate assembly according to Embodiment 1. 
         FIG.  4    is a plan view of the electrical junction box according to Embodiment 1. 
         FIG.  5    is a perspective view illustrating an outer appearance of an electrical junction box according to Embodiment 2. 
         FIG.  6    is a perspective view illustrating an outer appearance of an electrical junction box according to Embodiment 3. 
         FIG.  7    is a perspective view illustrating an outer appearance of an electrical junction box according to Embodiment 4. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Problems to be Solved by Present Disclosure 
     As fuses for protecting a circuit when an overcurrent flows, there are replaceable fuses and fixed fuses, which are used depending on the application. Replaceable fuses and fixed fuses are mounted on a corresponding substrate by different methods. 
     Replaceable fuses are fuses that are from the beginning expected to be replaced at some time, and are detachably connected to a substrate via holding members for temporarily holding the fuses. Also, fixed fuses are fuses that are originally not expected to be replaced, and are directly fixed to a substrate by, for example, soldering. 
     Also, in many electrical junction box, a housing that houses a substrate has a replacement opening for use in replacing replaceable fuses, and the replaceable fuses are exposed via the replacement opening. Accordingly, if an electrical trouble occurs, a user can easily check, through the replacement opening, whether or not any of the replaceable fuses has been blown out, and can replace the replaceable fuse without disassembling the housing. 
     On the other hand, if, in the event of an electrical trouble, it is found that no replaceable fuse has been blown out, it is also necessary to check whether or not any of the fixed fuses has been blown out. This results in a problem that it is not possible to check the fixed fuses without disassembling the housing. 
     However, the electrical junction box of Patent Document 1 does not mention any method for checking fixed fuses, and thus cannot solve this problem. 
     The present invention was made in view of the above-described circumstances, and it is an object thereof to provide an electrical junction box for which a user can check whether or not a fixed fuse housed in a housing has been blown out, more easily. 
     Advantageous Effects of Present Disclosure 
     According to the present disclosure, it is possible to check whether or not any fixed fuse housed in a housing has been blown out, more easily. 
     Description of Embodiments of Present Invention 
     First, embodiments of the present disclosure will be listed and described. Also, at least some of the embodiments described below may be combined with each other as appropriate. 
     (1) According to an embodiment of the present disclosure, an electrical junction box includes a housing that houses a substrate to which a fuse is soldered, wherein the housing includes a checking opening for checking whether or not the fuse has been blown out. 
     In this embodiment, since the housing includes the checking opening for checking whether or not the fuse soldered to the substrate has been blown out, it is possible to easily check whether or not any fuse has been blown out, without disassembling this housing. 
     (2) The electrical junction box according to an embodiment of the present disclosure further includes a lid member for covering the checking opening. 
     In this embodiment, since the lid member covers the checking opening, it is possible to prevent dust or the like from entering the housing via the checking opening. 
     (3) In the electrical junction box according to an embodiment of the present disclosure, the lid member can open and close. 
     In this embodiment, since the lid member can open and close, a user can open the lid member and performs a predetermined treatment on the fuse via the checking opening, for example. 
     (4) In the electrical junction box according to an embodiment of the present disclosure, the lid member includes a transparent part. 
     In this embodiment, since the lid member includes a transparent part, the user can check whether or not any fuse has been blown out from this transparent part, without opening the lid member. 
     (5) In the electrical junction box according to an embodiment of the present disclosure, the housing has a flat cuboid shape, the substrate is arranged facing two main surfaces of the housing, and the checking opening is formed in one of the main surfaces at a position that corresponds to the fuse. 
     In this embodiment, since the checking opening is formed in the main surface on the mounting surface side of the substrate at a position that corresponds to the fuse when viewed in the thickness direction of the substrate, it is possible to easily check whether or not the fuse has been blown out, and perform a corresponding treatment, for example. 
     (6) In the electrical junction box according to an embodiment of the present disclosure, the housing has a flat cuboid shape, the substrate is arranged facing two main surfaces of the housing, and the checking opening is formed in a side surface of the housing that is closest to the fuse. 
     In this embodiment, since the checking opening is formed in a side surface of the housing that is closest to the fuse, it is possible to easily check whether or not the fuse has been blown out, and perform the corresponding treatment, for example. 
     (7) In the electrical junction box according to an embodiment of the present disclosure, the housing has a flat cuboid shape, the substrate is arranged facing two main surfaces of the housing, and the checking opening is formed in a side surface of the housing that is closest to the fuse, while extending over the two main surfaces. 
     In this embodiment, since the checking opening is formed in a side surface of the housing that is closest to the fuse, while extending over the two main surfaces, it is possible to easily check whether or not the fuse has been blown out. Also, for example, when, in the event of a blowout of the fuse, a user inserts a soldering iron or the like into the checking opening and performs a treatment, it is possible to increase the convenience of the operation. 
     DETAILS OF EMBODIMENTS OF PRESENT INVENTION 
     The following will describe the electrical junction box according to embodiments of the present disclosure with reference to the drawings. Note that the present invention is not limited to the examples but is defined by the claims, and all modifications within the meaning and scope equivalent to the claims are intended to be included. 
     Embodiment 1 
       FIG.  1    is a perspective view illustrating an outer appearance of an electrical junction box  100  according to Embodiment 1. The electrical junction box  100  is a so-called vehicular junction box provided with fuses. 
     In the present embodiments, for convenience, “front”, “rear”, “left”, “right”, “up”, and “down” of the electrical junction box  100  are defined based on the front-rear direction, left-right direction, and up-down direction of the drawings. The following description will be given based on the front-rear direction, the left-right direction, and the up-down direction thus defined. 
     The electrical junction box  100  includes a case member  30  that houses a later-described substrate assembly  20 . The case member  30  has a flat cuboid shape, and includes an upper case part  31  and a lower case part  32 . The upper case part  31  is a housing whose lower face is open, and the lower case part  32  is a housing whose upper face is open. The upper case part  31  covers the lower case part  32  and forms one piece therewith, and the substrate assembly  20  is attached to the lower case part  32 . 
       FIG.  2    is a perspective view illustrating a state of the electrical junction box  100  according to Embodiment 1 where the upper case part  31  is removed.  FIG.  3    is a perspective view illustrating the substrate assembly  20  according to Embodiment 1. 
     The upper case part  31  includes a substantially rectangular ceiling plate  313  (main surface), and side plates  314  extending perpendicularly downward from side edges of the ceiling plate  313 . The upper case part  31  has a recess  34  in the region of the left-side edge thereof. 
     The lower case part  32  has a rectangular bottom plate  321  (main surface), and side plates  322  standing upright from side edges of the bottom plate  321 . The substrate assembly  20  is attached to the bottom plate  321 . The bottom plate  321  faces the ceiling plate  313 . 
     The substrate assembly  20  includes a substrate  21  that covers substantially the entire surface of the bottom plate  321  of the lower case part  32 , and circuit components mounted on the upper surface of the substrate  21 . That is to say, the substrate  21  faces the bottom plate  321  and the ceiling plate  313 . 
     Furthermore, the substrate  21  is provided with one connection port  60  in a front-side edge portion, and two connection ports  60  in a rear-side edge portion. The connection ports  60  are connected to the substrate  21  via connection terminals  61  that are bent in an L shape. Cutouts are formed in the side plates  314  of the upper case part  31  on the front and rear sides and in the side plates  322  of the lower case part  32  on the front and rear sides, and the connection ports  60  protrude to the outside of the case member  30  via the cutouts of the side plates  314  and the cutouts of the side plates  322 . 
     Also, two types of fuses, namely, a plurality of replaceable fuses  11  and a plurality of fixed fuses  10 , are mounted on the substrate  21 . The plurality of fixed fuses  10  are lined up in a row along the left-side edge of the substrate  21 , and the plurality of replaceable fuses  11  are lined up in a row on the side closer to a central portion of the substrate  21  than the fixed fuses  10  are. The fixed fuses  10  are mounted at an interval therebetween that is greater than the interval at which the replaceable fuses  11  are mounted. 
     The replaceable fuses  11  are from the beginning expected to be replaced at some time, and are held on the substrate  21  so as to be detachable. The fixed fuses  10  are not expected to be replaced, and are fixed to the substrate  21 . 
     The replaceable fuses  11  are connected, via holding terminals  19 , to a printed wiring board (not shown) or the like formed on the substrate  21 . Aplurality of holding terminals  19  are lined up in the front-rear direction. Each holding terminal  19  has a pair of U-shaped pinching parts, and the pair of pinching parts are disposed in parallel to each other in the left-right direction. 
     Each replaceable fuse  11  is attached spanning the space between the pair of pinching parts of the corresponding holding terminal  19 , and is detachably held. That is to say, the replaceable fuse  11  can be replaced by being inserted into and retracted from the holding terminal  19 . Therefore, the replaceable fuses  11  are easily replaceable. 
     In contrast, the fixed fuses  10  are fixed to the printed wiring of the substrate  21  by soldering. Therefore, the fixed fuses  10  are not easily replaceable. 
       FIG.  4    is a plan view of the electrical junction box  100  according to Embodiment  1 . 
     The recess  34  has a step part  315  formed on the ceiling plate  313  of the upper case part  31 , and a cutout  316  formed in the side plate  314 . A replacement window  311  is formed in the step part  315 . The replacement window  311  penetrates the ceiling plate  313  in the thickness direction, and is formed at a position matching the positions of the plurality of replaceable fuses  11  when viewed in the thickness direction (up-down direction) of the case member  30 . 
     As described above, since the plurality of replaceable fuses  11  are lined up in a row, the replacement window  311  has the shape of a rectangle whose longitudinal direction conforms to the direction in which the plurality of replaceable fuses  11  are lined up. Also, a pair of guide frames  317 , which are comb-shaped, are provided on the step part  315  along the long sides of the replacement window  311 . The pair of guide frames  317  are provided in a manner such that the open side of the guide frames  317  face each other. Each of the guide frames  317  has inside-oriented grooves at equal intervals, the number of grooves corresponding to the number of the plurality of replaceable fuses  11 . 
     All of the replaceable fuses  11  are exposed to the outside of the case member  30  via the replacement window  311 . Accordingly, when a replaceable fuse  11  is blown out, a user can replace this replaceable fuse  11  through the replacement window  311 . At this time, the insertion and removal of the replaceable fuse  11  are guided by the guide frames  317 . 
     Also, the step part  315  of the upper case part  31  includes a checking opening  33  for checking whether or not any fixed fuse  10  has been blown out. The checking opening  33  penetrates the ceiling plate  313  in the thickness direction, and is formed at a position matching the positions of the plurality of fixed fuses  10  when viewed in the thickness direction of the case member  30 . 
     As described above, since the plurality of fixed fuses  10  are lined up in a row, the checking opening  33  has the shape of a rectangle whose longitudinal direction conforms to the direction in which the plurality of fixed fuses  10  are lined up. That is to say, the checking opening  33  is rectangular, corresponding to the region of the substrate  21  in which the plurality of fixed fuses  10  are lined up, and has a length and a width that are sufficiently larger than those of the region in which the plurality of fixed fuses  10  are lined up. 
     All of the fixed fuses  10  are exposed to the outside of the case member  30  via the checking opening  33 . Accordingly, the user can check, through the checking opening  33 , whether or not any fixed fuse  10  has been blown out. 
     Also, as described above, the distance between the fixed fuses  10  is larger than the distance between the replaceable fuses  11 , and the short-side dimension (in the width direction) of the checking opening  33  is sufficiently larger than the long-side dimension of the fixed fuses  10 . Accordingly, if it is found that a fixed fuse  10  has been blown out, the user can insert, through the checking opening  33 , the distal end of a soldering iron to melt the solder, and remove and replace the blown-out fixed fuse  10 . Therefore, it is possible to save time and effort to disassemble the case member  30  for replacement of the fixed fuse  10  and the like, and perform such replacement promptly. 
     In the electrical junction box  100  according to Embodiment 1, the short-side dimension (width) of the checking opening  33  is not limited to the description above. It is sufficient that the short-side dimension of the checking opening  33  is sufficiently larger than the dimension (hereinafter, long-side dimension) of the fixed fuses  10  in a direction orthogonal to the direction in which the plurality of fixed fuses  10  are lined up, to the extent that it is possible to insert the distal end of a soldering iron via the checking opening  33  to melt the solder and remove the fixed fuse  10 . For example, the short-side dimension of the checking opening  33  is preferably at least 1.5 times as large as the long-side dimension of the fixed fuses  10 . 
     Note that, for example, the checking opening  33  may also be configured to have a transparent or translucent window. In this case, it is possible to prevent dust or the like from entering the case member  30  via the checking opening  33 . 
     Embodiment 2 
       FIG.  5    is a perspective view illustrating an outer appearance of an electrical junction box  100  according to Embodiment 2. 
     Similar to Embodiment 1, the electrical junction box  100  according to Embodiment 2 includes a case member  30 , and the case member  30  includes a substrate  21 , a plurality of replaceable fuses  11  held on the substrate  21  so as to be detachable, and a plurality of fixed fuses  10  fixed to the substrate  21 . 
     Also, the step part  315  of the upper case part  31  includes a replacement window  311  for replacing the replaceable fuses  11 , the replacement window  311  being formed at a position matching the positions of the plurality of replaceable fuses  11  when viewed in the thickness direction (up-down direction) of the case member  30 . 
     Furthermore, the step part  315  of the upper case part  31  includes a checking opening  33  for checking whether or not any fixed fuse  10  has been blown out. The checking opening  33  penetrates the ceiling plate  313  in the thickness direction, and is formed at a position matching the positions of the plurality of fixed fuses  10  when viewed in the thickness direction of the case member  30 . 
     The checking opening  33  is rectangular corresponding to the region of the substrate  21  in which the plurality of fixed fuses  10  are lined up, and is formed along the direction in which the plurality of fixed fuses  10  are lined up. The checking opening  33  has a length and a width that are sufficiently larger than those of the region in which the plurality of fixed fuses  10  are lined up. 
     The electrical junction box  100  according to Embodiment 2 further includes a lid member  40  that covers the checking opening  33  and can open and close. The lid member  40  is rectangular corresponding to the checking opening  33 , and has a dimension slightly larger than that of the checking opening  33 , for example. 
     The lid member  40  includes a window part (transparent part)  42  and a frame part  41 . The window part  42  is located in the center of the lid member  40 , is made of a resin, a glass, or the like, and is transparent or translucent. The frame part  41  is a rectangular frame and is made of a resin. The window part  42  is surrounded by the frame part  41 . 
     On the step part  315  of the upper case part  31 , a hinge  50  for rotating the lid member  40  is provided in the region of the shot-side of the checking opening  33 . 
     One of the short sides of the lid member  40  is coupled to the hinge  50 , and the lid member  40  rotates about the axis of the hinge  50  (see the dashed-two dotted line in  FIG.  5   ). By rotating in this way, the lid member  40  opens and closes the checking opening  33  (see the arrow in  FIG.  5   ). 
     In the electrical junction box  100  according to Embodiment 2 having the above-described configuration, the user can immediately check, through the window part  42  of the lid member  40 , whether or not any fixed fuse  10  has been blown out. 
     Also, since the checking opening  33  is covered by the lid member  40 , it is possible to prevent dust or the like from entering the case member  30  via the checking opening  33 . 
     Furthermore, since the lid member  40  can open and close, when it is found that any fixed fuse  10  has been blown out, the user can open the lid member  40 , insert the distal end of a soldering iron into the case member  30  from the checking opening  33  to melt the solder, and remove and replace the blown-out fixed fuse  10 . Therefore, it is possible to save time and effort to disassemble the case member  30  for replacement of the fixed fuse  10  and the like, and perform such replacement promptly 
     A case where the hinge  50  is provided in the region of a short-side of the checking opening  33  has been described as an example, but the present invention is not limited to this case. The hinge  50  may also be provided in the region of a long-side of the checking opening  33 . 
     A configuration is also possible in which the lid member  40  has the same dimension as that of the checking opening  33 , and the lid member  40  is fitted into the checking opening  33 . 
     Note that the electrical junction box  100  according to Embodiment 2 is not limited to the description above. For example, a configuration is also possible in which the lid member  40  does not have any frame part  41 , but is constituted only by the window part  42 . 
     The same reference numerals are given to the same components as those of Embodiment 1, and detailed descriptions thereof are omitted. 
     Embodiment 3 
       FIG.  6    is a perspective view illustrating an outer appearance of an electrical junction box  100  according to Embodiment 3. 
     Similar to Embodiment 1, the electrical junction box  100  according to Embodiment 3 includes a case member  30 , and the case member  30  includes a substrate  21 , a plurality of replaceable fuses  11  held on the substrate  21  so as to be detachable, and a plurality of fixed fuses  10  fixed to the substrate  21 . 
     Also, the step part  315  of the upper case part  31  includes the replacement window  311  for replacing the replaceable fuses  11 , the replacement window  311  being formed at a position matching the positions of the plurality of replaceable fuses  11  when viewed in the thickness direction (up-down direction) of the case member  30 . 
     Furthermore, in the electrical junction box  100  according to Embodiment 3, a checking opening  33 A for checking whether or not any fixed fuse  10  has been blown out is arranged in the side surface of the case member  30  that is closest to the plurality of fixed fuses  10 . 
     That is to say, in the electrical junction box  100  according to Embodiment 3, similar to Embodiment 1, the plurality of fixed fuses  10  are mounted while being lined up in a row along the left-side edge of the substrate  21  (see  FIG.  2   ), and the side surface of the case member  30  that is closest to the plurality of fixed fuses  10  is a side plate  314 A of the cutout  316 . Accordingly, in the electrical junction box  100  according to Embodiment  3 , the checking opening  33 A is formed in the side plate  314 A. 
     The checking opening  33 A penetrates the side plate  314 A in the thickness direction. The checking opening  33 A is rectangular corresponding to the region of the substrate  21  in which the plurality of fixed fuses  10  are lined up, and has a length that is sufficiently larger than that of the region in which the plurality of fixed fuses  10  are lined up. The long-side dimension (length) of the checking opening  33 A is sufficiently larger than that of the region in which the plurality of fixed fuses  10  are lined up. Also, the short-side dimension (width) of the checking opening  33 A is slightly smaller than the distance between the ceiling plate  313  (step part  315 ) and the bottom plate  321 . 
     Also, the electrical junction box  100  according to Embodiment 3 includes a lid member  40 A that covers the checking opening  33 A. The lid member  40 A is rectangular corresponding to the checking opening  33 A, and has dimensions equal to those the checking opening  33 A, for example. 
     The lid member  40 A includes a window part  42 A and a frame part  41 A. The window part  42 A is located in the center of the lid member  40 A, is made of a resin, a glass, or the like, and is transparent or translucent. The frame part  41 A is a rectangular frame and is made of a resin. The window part  42 A is surrounded by the frame part  41 A. 
     In the electrical junction box  100  according to Embodiment 3 having the above-described configuration, the user can immediately check, through the window part  42 A of the lid member  40 A, whether or not any fixed fuse  10  has been blown out. 
     Also, since the checking opening  33 A is covered by the lid member  40 A, it is possible to prevent dust or the like from entering the case member  30  via the checking opening  33 A. 
     Ordinarily, each fuse has its own information indicated on a surface (upper surface) thereof that can be seen from the mounting surface side of the substrate. Accordingly, when the user checks whether or not any fuse has been blown out from the mounting surface side of the substrate, such indication of information may get in the way of the user&#39;s checking. 
     To solve the problem, in the electrical junction box  100  according to Embodiment  3 , the checking opening  33 A is formed in the side plate  314 A of the case member  30  that is closest to the plurality of fixed fuses  10 . Therefore, the user can check whether or not any fuse  10  has been blown out, in a direction orthogonal to the thickness direction of the substrate  21 , that is, from the side surface of the fixed fuses  10 . Accordingly, even when the fixed fuses  10  have their own information indicated thereon, it is possible to reliably check whether or not any fixed fuse  10  has been blown out. 
     A case where the checking opening  33 A is formed in a portion of the side plate  314 A has been described as an example, but the electrical junction box  100  according to Embodiment 3 is not limited to this. For example, the checking opening  33 A may also be formed over the entire side plate  314 A. 
     Also, the electrical junction box  100  according to Embodiment 3 is not limited to the description above. For example, a configuration is also possible in which the lid member  40 A can open and close the checking opening  33 A. 
     The same reference numerals are given to the same components as those of Embodiment 1, and detailed descriptions thereof are omitted. 
     Embodiment 4 
       FIG.  7    is a perspective view illustrating an outer appearance of an electrical junction box  100  according to Embodiment 4.  FIG.  7    shows a state before a later-described lid member  40 B and a later-described checking opening  33 B are engaged with each other. 
     Similar to Embodiment 1, the electrical junction box  100  according to Embodiment 4 includes a case member  30 , and the case member  30  includes a substrate  21 , a plurality of replaceable fuses  11  held on the substrate  21  so as to be detachable, and a plurality of fixed fuses  10  fixed to the substrate  21 . 
     Also, the step part  315  of the upper case part  31  includes a replacement window  311  for replacing the replaceable fuses  11 , the replacement window  311  being formed at a position matching the positions of the plurality of replaceable fuses  11  when viewed in the thickness direction (up-down direction) of the case member  30 . 
     Furthermore, in the electrical junction box  100  according to Embodiment 4, the checking opening  33 B for checking whether or not any fixed fuse  10  has been blown out is formed on the left side of the case member  30  that is close to the fixed fuses  10 . 
     That is to say, in the electrical junction box  100  according to Embodiment 4, similar to Embodiment 1, the plurality of fixed fuses  10  are mounted while being lined up in a row along the left-side edge of the substrate  21  (see  FIG.  2   ). Accordingly, in the electrical junction box  100  of Embodiment  4 , the checking opening  33 B is formed in the left side plate  314 A of the case member  30 . The checking opening  33  is open in the side plate  314 A extending from the ceiling plate  313  to the bottom plate  321 . The following will describe the details thereof. 
     The checking opening  33 B is constituted by a rectangular opening portion  314 B formed in a portion of the side plate  314 A, a strip-shaped upper opening portion  312  that corresponds to the rectangular opening portion  314 B and is formed at the edge of the ceiling plate  313  (step part  315 ) on the side plate  314 A side, and a strip-shaped lower opening portion  323  that corresponds to the rectangular opening portion  314 B and is formed at an edge of the bottom plate  321  on the side plate  314 A side. The rectangular opening portion  314 B, the strip-shaped upper opening portion  312 , and the strip-shaped lower opening portion  323  are formed continuously. 
     The rectangular opening portion  314 B penetrates side plate  314 A in the thickness direction. The rectangular opening portion  314 B has the shape of a rectangle whose longitudinal direction conforms to the direction (front-rear direction) in which the plurality of fixed fuses  10  are lined up. The long-side dimension of the rectangular opening portion  314 B is sufficiently larger than the dimension, in the front-rear direction, of the region in which the plurality of fixed fuses  10  are lined up. Also, the short-side dimension of the rectangular opening portion  314 B is substantially equal to the distance from the ceiling plate  313  (step part  315 ) to the bottom plate  321 . 
     Also, the strip-shaped upper opening portion  312  is formed by cutting out the edge of the step part  315  on the side plate  314 A side in a strip shape, and has a longitudinal dimension equal to the longitudinal dimension of the rectangular opening portion  314 B in the longitudinal direction. Furthermore, the strip-shaped lower opening portion  323  is formed by cutting out the edge of the bottom plate  321  on the side plate  314 A side in a strip shape, and has a longitudinal dimension equal to the longitudinal dimension of the rectangular opening portion  314 B. 
     Furthermore, the electrical junction box  100  according to Embodiment 4 includes a lid member  40 B that covers the checking opening  33 B. The lid member  40 B has a shape corresponding to the checking opening  33 B. The lid member  40 B has a substantially C-shaped cross-section, and closes the checking opening  33 B by engaging with the checking opening  33 B (see arrows in  FIG.  7   ). That is to say, the lid member  40 B opens and closes the checking opening  33 B. 
     The lid member  40 B includes a window part  42 B and a frame part  41 B. The window part  42 B is rectangular, is made of a resin, a glass, or the like, and is transparent or translucent. 
     The frame part  41 B is made of a resin, and is constituted by a hollow portion  421  serving as a rectangular frame, an upper flange portion  422  extending from the upper long side of the hollow portion  421 , and a lower flange portion  423  extending from the lower long side of the hollow portion  421 . The window part  42 B is surrounded by the hollow portion  421 , and the upper flange portion  422  and the lower flange portion  423  protrude in the thickness direction of the hollow portion  421 . 
     That is to say, the hollow portion  421  has a shape corresponding to the rectangular opening portion  314 B, the upper flange portion  422  has a shape corresponding to the strip-shaped upper opening portion  312 , and the lower flange portion  423  has a shape corresponding to the strip-shaped lower opening portion  323 . 
     In the electrical junction box  100  according to Embodiment 4 having the above-described configuration, the user can immediately check, through the window part  42 B of the lid member  40 B, whether or not any fixed fuse  10  has been blown out. 
     Furthermore, the checking opening  33 B is formed in the side plate  314 A of the case member  30  that is closest to the plurality of fixed fuses  10 . Therefore, the user can check whether or not any fuse  10  has been blown out, in a direction orthogonal to the thickness direction of the substrate  21 , that is, from the side surface of the fixed fuses  10 . Accordingly, as described above, even when the fixed fuses  10  have their own information indicated on the upper surface thereof, it is possible to reliably check whether or not any fixed fuse  10  has been blown out. 
     Also, since the checking opening  33 B is covered with the lid member  40 B, it is possible to prevent dust or the like from entering the case member  30  via the checking opening  33 B. 
     Furthermore, since the lid member  40 B can open and close, if any fixed fuse  10  is blown out, the user can open the lid member  40 B, insert the distal end of a soldering iron into the case member  30  through the checking opening  33 B to melt the solder, and remove and replace the blown-out fixed fuse  10 . 
     Moreover, in the electrical junction box  100  according to Embodiment 4, the checking opening  33 B is not only formed in the side plate  314 A but also extends over the ceiling plate  313  and the bottom plate  321 , the operation of replacing a fixed fuse  10  is easy and the operability can be increased. 
     The same reference numerals are given to the same components as those of Embodiment 1, and detailed descriptions thereof are omitted. 
     The embodiments disclosed herein are examples in all respects, and should be construed as non-limiting. The scope of the present invention is defined by the claims, and all modifications within the meaning and scope equivalent to the claims are intended to be included. 
     List of Reference Numerals 
       10  Fixed fuse
 
 11  Replaceable fuse
 
 19  Holding terminal
 
 20  Substrate assembly
 
       21  Substrate 
       30  Case member
 
 31  Upper case part
 
 33 ,  33 A,  33 B Checking opening
 
       34  Recess 
       40 ,  40 A,  40 B Lid member
   41 ,  41 A,  41 B Frame part
   42 ,  42 A,  42 B Window part
   60  Connection port
 
 61  Connection terminal
 
 100  Electrical junction box
 
 311  Replacement window
 
 312  Strip-shaped upper opening portion
 
 313  Ceiling plate
 
 314  Side plate
 
 314 B Rectangular opening portion
 
 315  Step part
 
 317  Guide frame
 
 321  Bottom plate
 
 322  Side plate
 
 323  Strip-shaped lower opening portion