Abstract:
An electrical connection box for a vehicle has bus bars providing terminals which stand up close to each other, and an insulation plate through which the terminals project. A case member covering the insulation plate provides housing spaces for the terminals. A partitioning wall of the casing separating the housing spaces contacts the upper end of an upstanding wall of the insulation plate. One of the partitioning walls and the upstanding walls has a recess and the other has a projection received in the recess. This prevents liquid passage from one housing space to the other, and minimizes risk of current leak between terminals.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of Invention  
           [0002]    The present invention relates to an electrical connection box suitable to be mounted on an industrial product such as a vehicle or a robot, and more particularly an electrical connection box accommodating bus bars having terminals for connection to another component such as a relay.  
           [0003]    2. Description of Related Art  
           [0004]    Electric and electronic parts for a vehicle are mounted in a vehicle body by accommodating them in an electrical connection box. JP-A-63-81616 shows an example of a known electrical connection box having an insulation plate carrying bus bars. Terminals are formed by bending the bus bars so that end portions extend upward, and engage relay terminals. A cover member overlies the insulation plate and has apertures through which connection can be made to the relay terminals. The insulation plate has upstanding walls between the terminals to provide some insulation between them, so that the terminals may be close to each other. However, if water or the like penetrates into the space containing the terminals, there is insufficient insulation, so that there is a risk that a current leak may occur between the terminals  56   a ,  56   b.    
         SUMMARY OF THE INVENTION  
         [0005]    Accordingly, it is an object of the present invention to provide an electrical connection box capable of preventing or minimizing risk of a current leak due to penetration of water or the like into the box.  
           [0006]    According to the invention there is provided an electrical connection box having  
           [0007]    a plurality of bus bars providing at least two terminals which stand up close to each other,  
           [0008]    an insulation plate overlying the bus bars and having respective apertures through which the terminals project and further having at least one upstanding wall adjacent the apertures and having an upper end,  
           [0009]    a case member covering the insulation plate and having walls providing respective housing spaces for the terminals including a partitioning wall separating an adjacent pair of housing spaces,  
           [0010]    wherein the partitioning wall has a lower end in contact with the upper end of the upstanding wall and one lower end of the partitioning wall and the upper end of the upstanding wall has a recess and the other thereof has a projection received in the recess.  
           [0011]    Preferably, the recess is an elongate groove of tapering cross-section and the projection is an elongate ridge of tapering cross-section. In this case, the groove is preferably at the upper end of the upstanding wall. The base of the groove may be inclined horizontally along the groove.  
           [0012]    Alternatively, the recess is on the lower end of the partitioning wall and the projection is on the upper end of the upstanding wall.  
           [0013]    In the invention, when the insulating plate and the case member are combined with each other, the upstanding wall of the plate contacts the lower end of the partitioning wall which separates the terminals from each other. The recess formed on the upper end surface of the upstanding wall or on the lower end surface of the partitioning wall receives the corresponding projection. Therefore, compared with a case where the upper end of the upstanding wall or the lower end of the partitioning wall is flat, the terminals are separated by an elongate path. Thus, even though water or the like penetrates into the terminal spaces and into a gap between the upstanding wall and the partitioning wall, it is possible to minimize the risk of a current leak occurring between the terminals.  
           [0014]    Preferably, the recess is a groove formed on the upper end of the upstanding wall. Thus, even though water or the like penetrates into the gap between the upstanding wall and the partitioning wall, the water collects in the groove. Further, the groove may have an inclination, so that the water flows to the outside. This further reduces the risk of a current leak.  
           [0015]    Alternatively, the projection is formed on the upper end of the upstanding wall. Therefore, even though water or the like penetrates into a gap between the partitioning wall and the upstanding wall, the projection prevents flow of the water through the gap. Thus, it is difficult for the water or the like to penetrate the gap between the partitioning wall and the upstanding wall. Thus, the risk of current leak is also minimized.  
           [0016]    The invention further provides an industrial product, such as a vehicle or a robot, having such an electrical connection box mounted on it. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    Embodiments of the invention will now be described by way of non-limitative example with reference to the drawings, in which:  
         [0018]    [0018]FIG. 1 is an exploded perspective view showing a part of an electrical connection box which is an embodiment of the present invention.  
         [0019]    [0019]FIG. 2 is an enlarged perspective view of a portion of the electrical connection box of FIG. 1.  
         [0020]    [0020]FIG. 3 is a sectional view on line A-A of FIG. 1.  
         [0021]    [0021]FIG. 4 is a sectional view showing a stack member and a case have been combined with each other.  
         [0022]    [0022]FIG. 5 is a sectional view showing a part of an electrical connection box which is another embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0023]    The electrical connection box of FIGS.  1  to  4 , which is intended for a vehicle such as an automobile, has a circuit member  12  containing bus bars in layers and a molded plastic case  14 , which is part of a casing of the box.  
         [0024]    As shown in FIGS. 3 and 4, the circuit member  12  is constructed of a plurality (three in the embodiment) of layers of bus bars  15   a - 15   c  and a plurality (four in the embodiment) of insulating plates  16   a - 16   d  stacked one on another. The layers of bus bars  15   a - 15   c  are separated from each other by the insulating plates  16   a - 16   d . The uppermost insulating plate  16   a  covers the upper surface of the uppermost bus bars  15   a.    
         [0025]    Terminals  17   a - 17   d  are formed by bending the bus bars  15   a - 15   c  so that they project upward through respective apertures  18   a ,  18   b  formed in the uppermost insulating plate  16   a . The terminals  17   a - 17   d  project from the insulating plate  16   a.    
         [0026]    Each of the terminals  17   a - 17   d  has a downward notch  19  formed at the centre of its upper end with two inward projections  20   a ,  20   b  at the mouth of the notch. When a plate or the like is inserted into the notch  19 , it is sandwiched between the inward projections  20   a ,  20   b  to establish a gripping connection. Adjacent terminals  17   a ,  17   b  and apertures  18   a ,  18   b  are formed at positions close to each other.  
         [0027]    As shown in FIGS.  1  to  4 , around each aperture  18   a ,  18   b  the plate  16   a  has walls  21 - 24  extending upwardly from the top surface of the plate  16  so as entirely to surround the respective terminals  17   a - 17   d.    
         [0028]    As shown in FIGS. 1 and 2, the walls  21 ,  22  are in connection with each other at their sides and an upstanding wall construction is constituted by through side walls  21   a ,  22   a . As shown in FIG. 3, the spacing C 1  between the peaks  25  of the side walls  21   a ,  22   a  is almost equal to the thickness C 2  of a partitioning wall  34   a  of the case  14  which will be described later. A groove  26  is formed downwardly between the peaks  25  of the side walls  21   a ,  22   a . The groove  26  is V-shaped and extends in the longitudinal direction of the peaks  25 , its base being inclined downwardly towards one end of the side walls  21   a ,  22   a  (see FIG. 2). In other words, the groove  26  is formed so that it becomes deeper towards the point P 2  shown in FIG. 2 from the point P 1  in FIG. 2. As shown in FIG. 3, inclined surfaces  27  are provided at the outer surface (left-hand side in FIG. 3) of the side wall portion  2   1   b  of the wall  21  and the outer surface (right-hand side in FIG. 3) of the side wall  22   b  of the wall  22 .  
         [0029]    As shown in FIG. 1, a zone  31  for installing an electric/electronic part is formed on the upper surface of the case  14 . Through-holes  31  a are formed at the zone  31  at positions corresponding to the respective terminals  17   a - 17   d . As shown in FIG. 3, on the rear surface of the case  14 , a terminal housing portion  32  is formed at the position corresponding to zone  31 . The housing portion  32  has a downward outer side wall  33  surrounding all the terminals  17   a - 17   d  and downward partitioning walls  34  separating the terminals  17   a - 17   d  from each other. Thereby a plurality of spaces  35  are formed by the housing portion  32  which are shown in FIG. 4, when the circuit member  12  and the case  14  are combined, accommodate the terminals  17   a - 17   d  separately.  
         [0030]    The partitioning wall  34   a  separating spaces  35   a ,  35   b , which accommodates adjacent terminals  17   a ,  17   b , tapers towards its lower end which is a pointed downward ridge  38  as seen in cross-section. When the circuit member  12  and the case  14  are combined, the wall  34   a  is inserted into the groove  26  between the side walls  21   a ,  21   b.    
         [0031]    An inclined surface  36  sloping outwardly toward its lower end is formed in the vicinity of the lower end of the inner surface of the outer side wall  33  of the housing portion  32 , in correspondence to the inclined surface  27  of the wall  21 . As shown in FIG. 4, when the circuit member  12  and the case  14  are combined these inclined surfaces  27 ,  36  contact. An inclined surface  37  sloping away from the aperture  18   b  towards the space  35   c  is formed in the vicinity of the lower end of the surface of a partitioning wall  34   b  facing the space  35   b . The partitioning wall  34   b  partitions the space  35   b  and the space  35   c  containing the terminal  17   c  from each other. The inclined surface  37  is formed in correspondence to the inclined surface  27  of the wall  22 . When the circuit member  12  and the case  14  are combined, the inclined surface  37  contacts the inclined surface  27 .  
         [0032]    In FIG. 4, to make the construction of the circuit member  12  and the case  14  clear, a slight gap is shown between the partitioning wall  34   a  and the side walls  21   a ,  21   b , and similarly, a slight gap is shown between the pairs of inclined surfaces  27 ,  36  and  27 ,  37  but in practice these faces are intended to contact.  
         [0033]    When the circuit member  12  and the case  14  are combined, an electric/electronic part  38  (a relay in the embodiment) is mounted on the installing zone  31 . Connection terminals  38   a  of the part  38  are inserted into the corresponding through-holes  31  a and fitted into terminals  17   a - 17   d  respectively to achieve electrical connection. In use, for example, the electrical connection box  11  is mounted in a vehicle compartment. The case  14  may be combined with a lower case (not shown) to enclose the circuit member  12 .  
         [0034]    This embodiment provides the following effects:  
         [0035]    (1) The walls  21 - 24  project up around the periphery of each terminal aperture of the uppermost insulating plate  16   a . When the circuit member  12  and the case  14  are combined, the pointed lower end of the partitioning wall  34   a  separating two terminals  17   a ,  17   b  is inserted into the groove  26  between the side walls  21   a ,  22   a . This elongates the path between the housing spaces  35   a ,  35   b , compared with the case where the abutting faces are flat, so that even if water or the like penetrates into the housing portion  32 , the possibility that a current leak will occur between the terminals  17   a ,  17   b  is reduced. The shape of the wall  34   a  and groove  26  minimizes penetration of water into the gap between the wall  34   a  and the side walls  21   a ,  22   a.    
         [0036]    In recent years, as more electric and electronic parts are mounted on a vehicle body, there is a tendency to adopt a battery voltage of 42V. Thus, prevention of the generation of current leakage is more critical.  
         [0037]    The groove  26  is formed downward from the peaks  25  of the side walls  21   a ,  22   a  so that if water or the like penetrates into this location it collects in the groove  26 . Further, because this groove has an inclination, water or the like collected in the groove  26  flows to outside along the inclined surface. This enhances protection against current leakage between the terminals  17   a ,  17   b.    
         [0038]    The inclined surface  36  sloping outward toward its lower end is formed in the vicinity of the lower end of the inner surface of the outer side wall  33  of the housing portion  32 . Thus water or the like flowing from above along the inner surface of the outer side wall  33  passes outside easily. This also helps to prevent current leaks.  
         [0039]    Similarly the inclined surface  37 , which slopes towards the accommodation space  35   c  toward its lower end, is formed in the vicinity of the surface of the partitioning wall  34   b  at the side of the housing  35   b , so that water or the like flowing from above along the surface of the partitioning wall  34   b  at the side of the housing space  35   b  passes easily to the accommodation space  35   c . That is, the water or the like tends not to collect in the housing space  35   b . This also assists in avoiding current leak between the terminals  17   a ,  17   b .  
         [0040]    This embodiment of the present invention may be altered, for example as follows:  
         [0041]    As shown in FIG. 5, instead of the groove  26  and downward projection, an upwardly tapering ridge  41  may be formed on the upper end surface  25  of the wall construction  21   a ,  22   a  and a corresponding groove  42  formed on the lower end of the partitioning wall  34   a . It is desirable to form the ridge  41  and groove  42  in such a way that they make surface contact. Thereby, even if water or the like penetrates into the gap between the partitioning wall  34   a  and the side walls  21   a ,  22   a , the ridge  41  helps to prevent the flow of the water. Thus it is difficult for the water to penetrate this gap, and thereby risk of current leak between the terminals  17   a ,  17   b  is minimised.  
         [0042]    In this embodiment, the groove  26  has an inclination. Instead the groove  26  may be formed so that it makes a surface contact all along its length with the lower end of the partitioning wall  34   a . This construction forms an elongated path between the spaces  35   a ,  35   b  and increases contact of the wall  34   a  and the side walls  21   a ,  22   a.    
         [0043]    It is possible to omit the formation of the inclined surface  36  formed on the outer side wall  33  or the inclined surface  37  formed on the partitioning wall  34   b.    
         [0044]    The electrical connection box  11  may be used for an industrial robot or the like, as well as a vehicle.  
         [0045]    While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention.