Patent Document

[0001]    This application claims priority from Japanese Patent Application No. 2006-254536 filed in the Japanese Patent Office on Sep. 20, 2006, the disclosure of which is incorporated herein by reference in its entirety. 
       BACKGROUND 
       [0002]    This invention relates to an electrical junction box. In embodiments, the invention more particularly relates to an electrical junction box that can reliably carry out a conductivity inspection for a terminal that projects from a bottom wall in a fuse, a relay, or a connector containing section of the box and can positively effect a conductivity sensing and a half-fitting sensing for the terminal, in the case where a fitting inspection between the terminal and a lance for holding the terminal is carried out by inserting a sensing pin assembly projecting from a conductivity inspection device into the containing section, without breaking the sensing pin assembly. 
         [0003]    In a process for manufacturing an electrical junction box, a conductivity inspection may be conducted to confirm whether or not an internal connection has failed. Failures can include, but are not limited to, failures such as a short circuit, an open circuit, miswiring, or the like. For example,  FIGS. 7 and 8  show an example of a related-art conductivity inspection process. A conductivity inspection device  1  includes a plurality of sensing pins  1   a  attached to a support plate  1   b  at a given pitch. The electrical junction box is subsequently set in the conductivity inspection device  1  where the sensing pins  1   a  are inserted into fuse containing sections  2  of the electrical junction box. When the sensing pins  1   a  contact mating terminals  3  that are inserted upward into and secured to the fuse containing sections  2 , the conductivity inspection begins (see JP 2005-326271A). 
         [0004]    Also, a terminal connected to an end of a wire harness may be inserted into the fuse containing section of the electrical junction box so that the wire harness terminal is coupled to a terminal of a fuse mounted in the fuse containing section. In this case, as shown in  FIG. 9 , an engaging projection  3   a - 1  on a side portion of a metal lance  3   a  of the inserted wire harness terminal  3  is engaged with an engaging recess  2   a - 1  of a resin lance  2   a  integrated with the fuse containing section  2 . Additionally, the resin lance  2   a  is fitted on the wire harness terminal  3  to secure the wire harness terminal  3  at a regular position in the fuse containing section  2 . 
         [0005]    Similarly, a wire harness terminal to be inserted into a relay or connector containing section is positioned by a resin lance. 
         [0006]    Accordingly, when a terminal is positioned and held in a fuse containing section or the like of the electrical junction box by a resin lance, a fitting inspection for detecting a failure in fitting (half-fitting) between the resin lance and the terminal can also be performed along with the conductivity inspection. The fitting inspection utilizes a conductivity inspection device  1  as shown, for example, in  FIG. 10 . The conductivity inspection device  1  includes a plurality of sensing pin assemblies  1   a  having a plurality of conductivity sensing pins  1   a - 1  and half-fitting pins  1   a - 2 . 
         [0007]    As shown in  FIG. 11 , if the resin lance  2   a  is inclined inward under a half-fitting condition between the terminal  3  and the resin lance  2   a , the half-fitting sensing pin  1   a - 2  inserted down into the fuse containing section  2  contacts with the inward inclined resin lance  2   a , thereby detecting the half-fitting. Also, since the half-fitting sensing pin  1   a - 2  cannot enter a gap between two resin lances  2   a , the conductivity sensing pin  1   a - 1  cannot reach a top surface  3   a - 2  of the metal lance  3   a , thereby disabling the conductivity sensing. 
         [0008]    On the other hand, as shown in  FIG. 12 , when the engaging projection  3   a - 1  on the metal lance  3   a  of the terminal  3  engages the engaging recess  2   a - 1  of the resin lance  2   a , and the terminal  3  and resin lance  2   a  are under a fitting condition, the half-fitting sensing pin  1   a - 2  inserted down into the fuse containing section  2  enters the gap between the two resin lances  2   a . This is due to the resin lance  2   a  standing straight and not being inclined inward. As a result, the conductivity sensing pin  1   a - 1  contacts with the top surface  3   a - 2  of the metal lance  3   a  of the terminal  3 , thereby enabling the conductivity sensing. 
         [0009]    In other words, if the conductivity sensing pin  1   a - 1  detects conductivity, one can determine that the terminal  3  and the resin lance  2   a  are under a fitting condition. 
         [0010]    On the other hand, when an electrical junction box is set in a conductivity inspection device in which a plurality of pairs of two pins (a conductivity sensing pin  1   a - 1  and a half-fitting sensing pin  1   a - 2 ) constituting a plurality of sensing pin assemblies  1   a  are projected, a working person manually inserts an electrical junction box  4  into a conductivity inspection device  1  in a direction shown by arrow A in  FIG. 13  while sliding an outer wall surface  4   a  of the electrical junction box  4  onto an inner wall surface  1   b  of the conductivity inspection device  1 . When the electrical junction box  4  is inserted perfectly so as to reach an inner part in the conductivity inspection device  1 , doors  1   c  provided on the opposite sides of the conductivity inspection device  1  are closed. 
         [0011]    However, as described above, since the electrical junction box  4  is set manually in the conductivity inspection device  1 , the electrical junction box can be improperly (i.e., obliquely) inserted into the device upon setting. In this case, the conductivity sensing pin  1   a - 1  or the half-fitting sensing pin  1   a - 2  projected from the conductivity inspection device  1  may be inserted at an angle into the fuse containing section  2  or the like, thereby being broken. In particular, the greater the number of conductivity sensing pins  1   a - 1  and half-fitting sensing pins  1   a - 2  projected from the conductivity inspection device  1 , the more conductivity sensing pins may be broken or deformed. Consequently, if the pins are deformed, it is impossible to conduct effective fitting and conductivity inspections. 
       SUMMARY 
       [0012]    In view of the above problems, an object of exemplary embodiments of the present invention is to provide an electrical junction box that can reliably conduct a conductivity sensing and a half-fitting sensing without breaking a conductivity sensing pin and/or a half-fitting sensing pin when the electrical junction box is set in a conductivity inspection device. The conductivity inspection device includes a sensing pin assembly from which the conductivity sensing pin and half-fitting sensing pin are projected. These conductivity and half-fitting sensing pins are inserted down into a fuse containing section or the like of the electrical junction box, and a terminal inserted and fixed in the containing section is subject to a conductivity inspection and a half-fitting inspection. 
         [0013]    In order to solve the above problems, exemplary embodiments of the present invention are directed to an electrical junction box adapted to be set at a regular position in a conductivity inspection device. A sensing pin assembly projecting from the conductivity inspection device includes a conductivity sensing pin and a half-fitting sensing pin. When the sensing pin assembly is inserted into a containing section for a fuse, a relay, a connector, or a terminal in the containing section is subject to a conductivity inspection and a half-fitting inspection. Exemplary embodiments of the electrical junction box include: at least two guide holes formed in a surface wall of a casing provided with the containing section and spaced away from each other by a given distance; and guide pins that extend beyond the sensing pin assembly in the conductivity inspection device and are inserted into the guide holes, before the sensing pin assembly is inserted into the containing section. 
         [0014]    As described above, at least two guide holes are formed in the surface wall of the casing provided with the containing section of the electrical junction box; the guide pins projected from the conductivity inspection device over the sensing pin assembly including the conductivity and half-fitting sensing pins are inserted into the guide holes; and the electrical junction box is positioned and set in the conductivity inspection device. That is, at least two guide holes are formed in the surface wall of the casing so that when the guide pins project from the guide holes all of the sensing pins are inserted into the containing section at the regular positions. Accordingly, merely by inserting the guide pins into and projecting them from the guide holes, all sensing pins are inserted into the containing section at the regular positions without being inserted at an angle. Thus, since the electrical junction box is positioned and set in the conductivity inspection device, it is possible to effectively prevent the sensing pins from being broken and to reliably carry out the half-fitting sensing and conductivity sensing. 
         [0015]    An amount of projecting the guide pin of the conductivity inspection device from the guide hole can be set to be about a length by which the guide pin has extended already over the guide hole when the sensing pin assembly including the conductivity sensing pin and half-fitting sensing pin is inserted in the containing section. 
         [0016]    Preferably, a diameter of the guide hole formed in the surface wall of the casing can have a clearance sufficient to automatically define an inserting position of the sensing pins without causing a play upon passing while the guide pins are allowed to move smoothly. 
         [0017]    Also, two guide holes can be formed in the surface wall of the casing and spaced away from each other at empty spaces that do not affect a wiring in the electrical junction box. When the guide pines are inserted into the guide holes, the electrical junction box can be set in the conductivity inspection device at the regular position. 
         [0018]    Preferably, the number of guide holes is two. 
         [0019]    Preferably, the containing section is provided on a peripheral wall with an arcuate recess for guiding the conductivity sensing pin adapted to contact with a distal end surface of the terminal. The conductivity sensing pin guided by the recess can reach the distal end surface of the terminal to enable the conductivity sensing in the case where the terminal is fixed at a regular position in the containing section. The conductivity sensing pin guided by the recess cannot reach the distal end surface of the terminal to disenable the conductivity sensing in the case where the terminal is not fixed at the regular position in the containing section. 
         [0020]    As described above, in the prior art, the conductivity state has been detected when the conductivity sensing pin  1   a - 1  contacts with the metal lance  3   a  of the terminal  3 . As shown in  FIG. 14 , even if the terminal  3  is not fitted in the resin lances  2   a  at the regular position and the metal lance  3   a  of the terminal  3  are caught on a lower part of the engaging recess  2   a - 1  on the resin lance  2   a , the half-fitting sensing pin  1   a - 2  enters a gap between two resin lances  2   a  when the terminal  3  is inclined at a slight angle. The conductivity sensing pin  1   a - 1  does not contact with the metal lance  3   a  by which a conductivity state should be checked primarily but contacts with the side surface  3   b  of the terminal  3  on account of a slight inclination of the terminal  3 . This results in conductivity being detected, and therefore a worker performing a fitting and conductivity inspections may mistakenly judge the assembly to be acceptable even though the terminal  3  and resin lances  2   a  are under the half-fitting condition. 
         [0021]    As described above, the containing section is provided on the peripheral wall with the arcuate recess for guiding the conductivity sensing pin, and the conductivity sensing pin guided by the recess can detect the conductivity state at the distal end surface of the terminal. Thus, when the metal lance of the terminal is positioned below the engaging recess of the resin lance (i.e., the terminal is under the half-fitting condition), the conductivity sensing pin cannot reach the distal end surface of the terminal and the conductivity sensing pin does not contact with the side surface of the terminal. Accordingly, the conductivity state cannot be detected. Thus, even in a half-fitting condition, it is possible to reduce the possibility that a worker will mistakenly judge the assembly to be acceptable. That is, according to the above construction, only in the case where the terminal is secured at the regular position in the electrical junction box, the conductivity sensing pin guided by the recess can reach the distal end surface of the terminal, thereby detecting the conductivity state. 
         [0022]    As described above, according to exemplary embodiments of the present invention, at least two guide holes are formed in the surface wall of the casing provided with the containing section of the electrical junction box; the guide pins projected from the conductivity inspection device over the sensing pin assembly including the conductivity and half-fitting sensing pins are inserted into the guide holes; all sensing pins are inserted into the containing section at the regular positions merely by inserting the guide pins into the guide holes and projecting the guide pins from the guide holes; and the electrical junction box is positioned and set in the conductivity inspection device without causing all sensing pins to be inserted obliquely. Thus, it is possible to effectively prevent the sensing pins from being broken and to reliably carry out the half-fitting sensing and conductivity sensing. 
         [0023]    Also, as described above, the containing section is provided on the peripheral wall with the arcuate recess for guiding the conductivity sensing pin and the conductivity sensing pin guided by the recess can detect the conductivity state at the distal end surface of the terminal. In results, in the case where the metal lance of the terminal is positioned below the engaging recess of the resin lance, that is, the terminal is under the half-fitting state, the conductivity sensing pin cannot reach the distal end surface of the terminal and the conductivity sensing pin does not contact with the side surface of the terminal. Accordingly, the conductivity state cannot be detected. Even in a half-fitting condition, it is possible to reduce the possibility that a worker will mistakenly judge the assembly to be acceptable. That is, according to the above construction, only in the case where the terminal is secured in the electrical junction box at the regular position, the conductivity sensing pin guided by the recess can reach the distal end surface of the terminal, thereby detecting the conductivity state. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    Exemplary embodiments of the invention will be described below with reference to the drawings, wherein like numerals represent like parts, and wherein: 
           [0025]      FIG. 1  is a schematic plan view of an embodiment of an electrical junction box in accordance with the present invention; 
           [0026]      FIG. 2  is an explanatory view, illustrating a fitting state between a terminal and a lance in a fuse containing section; 
           [0027]      FIG. 3  is a schematic explanatory view, illustrating a process for setting the electrical junction box into a conductivity inspection device; 
           [0028]      FIG. 4  is an enlarged view of a sensing pin assembly; 
           [0029]      FIG. 5  is an explanatory view, illustrating a state of inserting the sensing pin assembly into the fuse containing section; 
           [0030]      FIG. 6  is a plan view of the fuse containing section; 
           [0031]      FIG. 7  is an explanatory view of a conventional conductivity inspection device; 
           [0032]      FIG. 8  is an explanatory view of a conventional electrical junction box; 
           [0033]      FIG. 9  is an explanatory view, illustrating a fitting state between a terminal and a lance in a fuse containing section in the conventional electrical junction box; 
           [0034]      FIG. 10  is an explanatory view of a conventional conductivity inspection device; 
           [0035]      FIG. 11  is an explanatory view, illustrating a state of inserting a sensing pin assembly into the fuse containing section in the conventional electrical junction box; 
           [0036]      FIG. 12  is an explanatory view, illustrating another state of inserting the sensing pin assembly into the conventional fuse containing section; 
           [0037]      FIG. 13  is a schematic explanatory view, illustrating a process for setting the conventional electrical junction box into a conductivity inspection device; and 
           [0038]      FIG. 14  is an explanatory view, illustrating another state of inserting the sensing pin assembly into the conventional fuse containing section. 
       
    
    
     DETAILED DESCRIPTION 
       [0039]    An exemplary embodiment of an electrical junction box in accordance with the present invention will be described below by referring to the drawings. 
         [0040]      FIGS. 1 through 6  show an embodiment of an electrical junction box in accordance with the present invention. As shown in  FIG. 1 , an electrical junction box  10  includes a fuse containing section  12 , a relay containing section  13 , and a connector containing section  14  provided on a top wall  11   a  of a casing  11 . Fuses, relays, and connectors (not shown) are mounted in these containing sections  12 ,  13 , and  14 , respectively. A terminal  15  is connected to a distal end of a wire harness W accommodated in the casing  11  (see  FIG. 2 ). The terminal  15  is inserted into the fuse containing section  12  and is connected to a terminal of a fuse to be coupled. As shown in  FIG. 2 , the terminal  15  is fitted on a resin lance  12   a  integrated with the fuse containing section  12  by engaging an engaging projection  15   a - 1  on a metal lance  15   a  of the terminal  15  with an engaging recess  12   a - 1  of the resin lance  12   a.    
         [0041]    As described above, the fitting and conductivity inspections for the terminal  15  inserted into and secured to the fuse containing section  12  are carried out by setting the electrical junction box  10  in a conductivity inspection device  20 , as shown in  FIG. 3 . Sensing pin assemblies  21  project into the interior of the fuse containing section  12  to be subjected to the fitting and conductivity inspections. The number of the sensing pin assemblies  21  corresponds to the number of terminals  15  in the fuse containing section  12 . 
         [0042]    As shown in  FIG. 4 , each of the sensing pin assemblies  21  includes a conductivity sensing pin  21   a  and a half-fitting sensing pin  21   b . As shown in  FIG. 3 , the conductivity inspection device  20  is further provided with two guide pins  22  and  23  that extend beyond the sensing pin assemblies  21 . 
         [0043]    As shown in  FIG. 1 , the electrical junction box  10  is provided at separated empty spaces on the top wall  11   a  of the casing  11  with guide holes  16  and  17  adapted to receive the guide pins  22  and  23 . The guide holes  16  and  17  are formed in the top wall  11   a  so that the respective sensing pin assemblies  21  can be inserted into the fuse containing section  12  at regular positions when the guide pins  22  and  23  are inserted into the guide holes  16  and  17 , respectively. When the sensing pin assemblies  21  are inserted into the fuse containing section  12 , the guide pins  22  and  23  project from the guide holes  16  and  17 . In this embodiment, clearances between inner peripheral surfaces of the guide holes  16 ,  17  and outer peripheral surfaces of the guide pins  22 ,  23  are set to be 0.2 mm (millimeters), but the clearances can be set to be greater or less than 0.2 mm. 
         [0044]    As shown in  FIGS. 5 and 6 , each fuse containing section  12  is provided with an arcuate recess  18  at a distal end side on an inner surface of a peripheral wall. The recess  18  serves to guide the conductivity inspection pin  21   a  so as to contact with a distal end surface  15   b  of the terminal  15  so that the recess  18  eventually contacts with an outer peripheral surface of the conductivity sensing pin  21   a.    
         [0045]    In the case where terminals in the fuse containing section  12  at input and output sides are simultaneously inspected with respect to conductivity and fitting, two recesses  18  may be provided at symmetrical positions of the peripheral wall of the fuse containing section  12 . 
         [0046]    The conductivity inspection and fitting inspection for the terminals  15  fixed in the fuse containing section  12  will be described below. 
         [0047]    First, as shown in  FIG. 3 , the electrical junction box  10  is moved in a direction shown by an arrow A to set the box  10  in the conductivity inspection device  20 . Then, the guide pins  22  and  23  are inserted into the guide holes  16  and  17  to project from the guide holes  16  and  17 , respectively. Thus, the respective sensing pin assemblies  21  are inserted in the respective fuse containing sections  12  at the regular positions and the electrical junction box  10  is positioned in the conductivity inspection device  20 . 
         [0048]    Then, the conductivity sensing pin  21   a  is inserted into the fuse containing section  12  while contacting the recess  18 . 
         [0049]    Thus, the engaging projection  15   a - 1  on the metal lance  15   a  of the terminal  15  is engaged with the engaging recess  12   a - 1  of the resin lance  12   a ; the half-fitting sensing pin  21   b  enters a gap between the two resin lances  12   a  so long as the terminal  15  is fitted on the resin lances  12   a  at the regular positions; the conductivity sensing pin  21   a  reaches the distal end surface  15   b  of the terminal  15 ; and the conductivity sensing can be effected. 
         [0050]    As described above, at least two guide holes  16  and  17  are formed in the surface wall of the casing  11  provided with the fuse containing section  12  of the electrical junction box  10 ; the guide pins  22  and  23  of the conductivity inspection device  20  extend beyond the sensing pin assemblies  21  including the conductivity sensing pins  21   a  and the half-fitting sensing pins  21   b ; the guide pins  22  and  23  are inserted into the guide holes  16  and  17  to project from the holes  16  and  17 ; and the sensing pin assemblies  21  (sensing pins  21   a  and  21   b ) are inserted into the respective fuse containing sections  12  at the regular positions without being inserted obliquely. Consequently, it is possible to effectively prevent the sensing pin assemblies  21  (sensing pins  21   a  and  21   b ) from being broken and to reliably carry out the half-fitting sensing and conductivity sensing. 
         [0051]    As described above, the respective fuse containing sections  12  are provided on the peripheral wall with the arcuate recesses  18  for guiding the conductivity sensing pins  21   a ; the conductivity sensing pins  21   a  guided by the recesses  18  can sense the conductivity at the distal end surface  15   b  of the terminal  15 ; and the conductivity sensing pins  21   a  cannot reach the distal end surface  15   b  of the terminal  15  and the conductivity sensing pin  21   a  cannot contact with a side surface of the terminal  15  when the terminal is under the half-fitting position where the metal lance  15   a  of the terminal  15  is arranged below the engaging recess  12   a - 1  of the resin lance  12   a . Thus, conductivity cannot be detected. Accordingly, even in a half-fitting condition, it is possible to reduce the possibility that a worker will mistakenly judge the assembly to be acceptable. That is, according to the above construction, only in the case where the terminal  15  is fixed in the fuse containing section  12  at the regular position, the conductivity sensing pin  21   a  guided by the recess  18  can reach the distal end surface  15   b  of the terminal  15  to enable the conductivity sensing. 
         [0052]    The embodiments described above are intended to be illustrative and not limiting. Various modifications, substitutes and/or improvements are possible within the spirit and scope of the invention.

Technology Category: 3