Abstract:
A junction box comprises small size standard boxes. The small size standard box includes a main casing that contains many longitudinal bus bars disposed in parallel with one another at a given interval in distance therein, and male and female coupling portions provided on the outer opposite side surfaces of the main casing. Plural small size standard boxes are juxtaposed together in accordance with different kinds of automobile vehicles by interconnecting the male and female coupling portions successively. A lower casing member is attached to the main casing. The size of the lower casing member depends on the number of the standard boxes to be coupled for a special purpose. The lower casing member is provided with an attachment portion for a vehicle body projecting from the member.

Description:
CLAIM FOR PRIORITY  
         [0001]    This application claims priority to Japanese Patent Application No. 2002-368890 filed Dec. 19, 2002, the entire disclosure of which is incorporated herein by reference in its entirety.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of Invention  
           [0003]    This invention relates to a junction box and more particularly to a junction box in which a plurality of small size standard boxes are coupled to one another to be used in different types of automobile vehicles.  
           [0004]    2. Description of Related Art  
           [0005]    Heretofore, in order to easily change a bus bar circuit in a junction box that is to be mounted on an automobile vehicle, Japanese Patent Public Disclosure 2001-145231 has proposed a junction box.  
           [0006]    A prior art connector will be described by referring to FIGS. 10 and 11. FIG. 10 is an exploded perspective view of a conventional junction box. FIGS. 11A to  11 E are plan views of junction boxes to meet special purposes for various kinds of automobile vehicles.  
           [0007]    With reference to FIG. 10, the junction box  1  includes an upper casing member  2  and a lower casing member  3 . Longitudinal bus bars  4  are accommodated in parallel with one another in an interior defined between the upper and lower casing members  2  and  3 . Each of the bus bars  4  includes a plate-like bus bar body  4   a,  tabs  4   b  that project from the bus bar body  4   a  toward the upper casing member  2 , and insulation displacement blades  4   c  which project from the bus bar body  4   a  toward the lower casing member  3 . An electrical cable  5  is pushed into the insulation displacement blades  4   c  of different bus bars  4 . It is possible to easily alter a bus bar circuit by electrically coupling the different bus bars  4  to one another.  
           [0008]    The above junction box can carry out a circuit alteration easily to a certain extent. However, since the electrical cable  5  electrically couples the longitudinal bus bars  4  in a single junction box  1 , the circuit alteration is limited within a scope and such structure cannot be applied to a great circuit alteration such as an alteration for a different type of an automobile vehicle. As shown in FIGS. 11A to  11 E, each junction box must be developed for the special purpose of a particular type of an automobile vehicle. Consequently, there are problems of increase in man-hours for development of each junction box and also the cost of a die for the bus bar.  
           [0009]    Accordingly, an object of the present invention is to provide a junction box that can reduce man-hours for the development of a junction box and also lower the cost of a die for a bus bar by sharing the junction box.  
         SUMMARY OF THE INVENTION  
         [0010]    In order to solve the above problems, the invention is directed to a junction box comprising a plurality of small size standard boxes. Each of the standard boxes may include a main casing that contains circuit parts, and male and female coupling portions can be provided on the outer opposite side surfaces of the main casing. The plural small size standard boxes are juxtaposed together in accordance with the different types of automobile vehicles by interconnecting the male and female coupling portions successively. A lower casing member may be attached to the main casing. The size of the lower casing member depends on the number of the standard boxes to be coupled for a particular purpose. The lower casing member can be provided with an attachment portion for a vehicle body that projects from the member.  
           [0011]    According to the above structure, it is possible to provide a small size standard box that can be commonly used in different types of automobile vehicles, to couple plural standard boxes to one another in accordance with a special requirement, to accommodate the coupled standard boxes together in a single lower casing member, and to produce a junction box in compliance with the different types of automobile vehicles. Since the lower casing member can be provided in accordance with the number of the coupled standard boxes and the main casing and bus bars that have complex structures can be shared respectively, it is possible to reduce man-hours for development of a junction box and also lower the cost of a die for the bus bar.  
           [0012]    Each of the small size standard boxes may contain many longitudinal bus bars disposed in parallel with one another at a given interval in distance therein. Each of the bus bars may also include a strap-like portion extending horizontally, a plurality of tabs projecting vertically from an upper edge of the strap-like portion at a given interval in distance, and a plurality of insulation displacement terminals projecting vertically from a lower edge of the strap-like portion at a given interval in distance. The tabs can be inserted into a connector containing section provided on an upper surface of each of the standard boxes. A jumper cable or a conductive pin may be connected to the insulation displacement terminals so that any longitudinal bus bar selected from the many juxtaposed longitudinal bus bars are electrically coupled to one another.  
           [0013]    The tabs project from the upper edge of the strap-like portion vertically at the given interval in distance. On the other hand, the insulation displacement terminals project from the lower edge of the strap-like portion vertically at the given interval in distance. The strap-like portion can be cut off or divided at desired positions in accordance with the circuit structure or, alternatively, any unnecessary insulation displacement terminals can be cut off.  
           [0014]    According to the above structure, the jumper cable or conductive pin can be pushed into the insulation displacement terminals provided on the bus bars so that any longitudinal bus bars selected from the juxtaposed longitudinal bus bars may be coupled to one another. Therefore, it is possible to easily change the bus bar circuits, enlarge applicability for the small size standard box, and apply the standard box to complex circuit construction.  
           [0015]    The jumper cable or the conductive pin may be connected to the insulation displacement terminals of the bus bars in the interconnected standard boxes to electrically couple the longitudinal bus bars between different standard boxes.  
           [0016]    According to the above structure, it is possible to easily change the bus bar circuits, enlarge applicability for the small size standard box, and apply the standard box to complex circuit constructions. It is also possible to eliminate a connector containing section for interconnecting the standard boxes and thus to downsize the standard box. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    The features of the invention are believed to be novel and the elements characteristic of the invention are set forth with particularity. The figures are for illustration purposes only and are not drawn to scale. The invention itself, however, both as to organization and method of operation, may best be understood by reference to the detailed description which follows taken in conjunction with the accompanying drawings in which:  
         [0018]    [0018]FIG. 1 is a plan view of a first embodiment of a junction box in accordance with the present invention;  
         [0019]    [0019]FIG. 2 is a plan view of a body casing;  
         [0020]    [0020]FIG. 3 is a perspective view of the body casing, illustrating a bottom side of the body casing;  
         [0021]    [0021]FIG. 4 is a perspective view of a longitudinal bus bar;  
         [0022]    [0022]FIG. 5 is an exploded perspective view of a standard box;  
         [0023]    [0023]FIG. 6 is a plan view of a lower casing member;  
         [0024]    [0024]FIG. 7 is a plan view of a second embodiment of a junction box in accordance with the present invention;  
         [0025]    [0025]FIG. 8 is a perspective view of a third embodiment of a junction box in accordance with the present invention;  
         [0026]    [0026]FIG. 9 is an exploded perspective view of a fourth embodiment of the invention;  
         [0027]    [0027]FIG. 10 is an exploded perspective view of a conventional junction box; and  
         [0028]    [0028]FIGS. 11A to  11 E are plan views of junction boxes to meet special purposes for different types of automobile vehicles. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0029]    In describing exemplary embodiments of the present invention, reference will be made herein to FIGS.  1  to  9  of the drawings in which like numerals refer to like features of the invention. Features of the invention are not necessarily shown to scale in the drawings.  
         [0030]    Referring now to the drawings, a first embodiment of a junction box  10  in accordance with the invention will be described below in FIGS.  1  to  6 . The junction box  10  includes two coupled small size standard boxes  11  and a lower casing member  12  containing the standard boxes  11 .  
         [0031]    [0031]FIGS. 2 and 3 show the standard box  11 . A main casing  13  of the standard box  11  is provided on a top surface thereof with five connector containing sections  14 . A bottom surface of main casing  13  has bus bar containing sections  15  that accommodate longitudinal bus bars  20  (FIG. 4). Also, terminal holes  16  extend between the bus bar containing sections  15  and the connector containing sections  14 . The main casing  13  may also be provided on one sidewall thereof with male coupling portions  17  and on the other sidewall may be provided with female coupling portions  18 . The portions  17  and  18  can be arranged opposite in direction to each other on the sidewalls so as to couple the adjacent standard boxes  11  to each other. Lock pawls  13   a  that can engage with lock holes  12   g  (FIG. 6) in the lower casing member  12  may be provided on longitudinal opposite ends of the main casing  13 . A lock pawl  13   b  may also be provided on the main casing  13  at a substantially central position of the sidewall on which the male coupling portions  17  are provided. A lock portion  13   c  may be provided on the opposite sidewall of the main casing  13 . The lock portion  13   c  may be arranged opposite in direction to the lock pawl  13   b.    
         [0032]    [0032]FIG. 4 shows a longitudinal bus bar  20 . The longitudinal bus bar  20  includes a strap-like portion  21  extending horizontally, tabs  22  projecting vertically from an upper edge of the strap-like portion  21  at a given interval in distance, insulation displacement terminals  23  projecting vertically from a lower edge of the strap-like portion  21  at a given interval in distance, and protrusions  24  projecting vertically from a lower edge of the strap-like portion  21  at a given interval in distance. The protrusions  24  are opposite in direction to the tabs  22 . The longitudinal bus bar  20  is formed into a given configuration by cutting off or dividing the strap-like portion  21 , or by cutting off unnecessary insulation displacement terminals  23 , if necessary.  
         [0033]    As shown in FIG. 5, the male coupling portions  17  of one main casing  13  can be inserted into the female coupling portions  18  of the other main casing  13 . Lock pawl  13   b  of the one main casing  13  can be engaged with the lock portion  13   c  (FIG. 2) of the other main casing  13 , so that two main casings  13  are coupled with each other. The longitudinal bus bar  20  can be formed into a given configuration and accommodated in the bus bar containing section  15  in the main casing  13 . The tabs  22  of the longitudinal bus bar  20  can be inserted through the terminal holes  16  into the connector containing section  14 . Furthermore, a jumper cable  30  having a single core wire can be pushed into the insulation displacement terminals  23  of the bus bar  20  to electrically couple the bus bars  20  to one another. In the present embodiment, a jumper cable  30 A electrically couples the longitudinal bus bars  20  contained in the same main casing  13  to one another while a jumper cable  30 B electrically couples the longitudinal bus bars  20  contained in the different main casings  13  to one another.  
         [0034]    [0034]FIG. 6 shows a lower casing member  12 . The lower casing member  12  can contain two small size standard boxes, such as boxes  11  shown in FIG. 1. The lower casing member  12  includes a bottom wall  12   a  and sidewalls  12   b.  The bottom wall  12   a  may be provided on an inner surface with bus bar receiving grooves  12   c  that extend in a direction along the longitudinal bus bars  20  and with straight ribs  12   d  that extend in a direction perpendicular to the bus bar receiving grooves  12   c.  The ribs  12   d  can be provided on the positions opposed to the protrusions  24  of the longitudinal bus bars  20  when a standard box containing the bus bars  20  is accommodated in the lower casing member  12 . A sidewall  12   b  may project outwardly at the positions corresponding to the male coupling portions  17  of the main casing  13  to provide containing portions  12   e  for the male coupling portion  17 . The sidewall  12   b  may also be provided with an attachment portion  12   f  for a vehicle body that has a bolthole  12   f - 1 . Further, the sidewall  12   b  can be provided on given positions thereof with the lock hole  12   g  and lock pawl  12   h.    
         [0035]    The lower casing member  12  houses two coupled standard boxes (FIG. 5). At this time, the insulation displacement terminals  23  projecting downwardly from the longitudinal bus bars  20  (FIG. 5) may be received in the bus bar containing grooves  12   c  in the lower casing member  12  while the ribs  12   d  contact with the protrusions  24  of the longitudinal bus bars  20  so that the longitudinal bus bars  20  are surely inserted into regular positions in the bus bar containing sections  15 . The male coupling portions  17  on the main casing  13  that are not coupled to the female coupling portions  18  may be accommodated in the containing portions  12   e  for the male coupling portions  17  of the lower casing member  12 . The lock pawls  13   a  and  13   b  of the main casing  13  can then be inserted into the lock holes  12   g  in the lower casing member  12  while the lock pawl  12   h  of the lower casing member  12  can be inserted into the lock portion  13   c  (FIG. 2) of the main casing  13 . Thus, the standard box  11  can be joined and locked on the lower casing member  12 .  
         [0036]    After the bolthole  12   f - 1  in the vehicle body attachment portion  12   f  of the lower casing  12  is aligned with a through-hole (not shown) in the vehicle body, the attachment portion  12   f  can be secured to the vehicle body by a bolt, thereby securing the junction box  10  to the vehicle body.  
         [0037]    According to the above structure, it is possible to provide the small size standard box  11  that can be used in different kinds of automobile vehicles, to couple a plurality of standard boxes  11  to one another in accordance with a special requirement, to accommodate the coupled standard boxes  11  together in a single lower casing member  12 , and to produce a junction box in compliance with the different kinds of automobile vehicles. Since the lower casing member  12  can be provided in accordance with the number of the coupled standard boxes  11  and the main casing  13  and bus bars  20  that have complex structures can be shared respectively, it is possible to reduce man-hours for development of the junction box and lower the cost of a die for a bus bar.  
         [0038]    The jumper cable  30  may also be pushed into the insulation displacement terminals  23  provided on the longitudinal bus bars  20  so that any longitudinal bus bars  20  selected from the juxtaposed longitudinal bus bars  20  can be coupled to one another. Therefore, it is possible to easily change the bus bar circuits, enlarge applicability for the small size standard box  11 , and apply the standard box  11  to complex circuit structures.  
         [0039]    [0039]FIG. 7 shows another embodiment of the invention in which a junction box  10 ′ includes three coupled standard boxes  11 .  
         [0040]    Thus, it is possible to form the junction box  10 ′ including three coupled standard boxes  11  merely by providing a lower casing member  12 ′ that can contain three standard boxes  11 . That is, it is possible in the invention to form a junction box that can comply with various circuit constructions merely by providing a lower casing member in accordance with the number of standard boxes  11  to be coupled. Since other aspects of this embodiment are the same as the first embodiment, further explanation is omitted.  
         [0041]    [0041]FIG. 8 shows an alternative exemplary embodiment of the invention. In this embodiment, instead of using jumper cable  30 , a conductive pin  40  is pushed into the insulation displacement terminals  23  of the longitudinal bus bars  20  to electrically couple the longitudinal bus bars  20  to one another.  
         [0042]    Since the above structure can cause the conductive pin  40  to be firmly connected to the insulation displacement terminals  23 , it is possible to make reliable electrical connection between the longitudinal bus bars  20 . Since other structures of this exemplary embodiment are the same as previous embodiments, further explanation is omitted.  
         [0043]    [0043]FIG. 9 shows yet another exemplary embodiment in which a jumper cable  30 B is bent and pushed into the insulation displacement terminals  23  of the longitudinal bus bars  20  contained in the different main casings  13  to electrically couple the bus bars  20  to one another. The above structure can enlarge applicability of junction box  10  and can apply the junction box  10  to a complex circuit construction.  
         [0044]    The conductive pin  40  in FIG. 8, as well as the jumper cable  30 , may be bent and pushed into the insulation displacement terminals  23  of the longitudinal bus bars. Also, the longitudinal bus bars  20  contained in the same main casing  13  may be electrically coupled by the bent jumper cable  30 A or conductive pin  40 .  
         [0045]    While the invention has been particularly described, in conjunction with specific exemplary embodiments, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. It is therefore contemplated that the appended claims will embrace any such alternatives, modifications, and variations as falling within the true scope and spirit of the present invention.