Patent Abstract:
An electrical connection box for a vehicle has a body and a power distribution element. A portion of the body upstanding from one face receives, in use, an electrical component such as a relay which at a fastening location is joined to the distribution element. A casing covers the component receiving portion. To reduce the risk of accidental contact with the fastening location, the box has a removable U-shaped cover covering the fastening location, the cover being enclosed within the casing. The cover has an aperture through which the electrical component projects, and the periphery of the aperture may contact the component receiving portion or the electrical component.

Full Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of Invention  
           [0002]    The present invention relates to an electrical connection box suitable to be installed on a vehicle, for example an automobile. More particularly, the invention relates to an electrical connection box accommodating an electrical component part, which is fastened to a power distribution element such as a bus bar or an electric wire of the connection box. The invention also relates to a vehicle having such an electrical connection box installed on it.  
           [0003]    2. Description of Related Art  
           [0004]    Electrical component parts in a vehicle are mounted on a vehicle body, accommodated in an electrical connection box. It is necessary to apply high current to some electrical component parts connected to a battery, an alternator, or the like. It is also necessary to fasten connection terminals of bus bars, electric wires and the like distribution elements to connection terminals of the electrical component parts by bolts or the like.  
           [0005]    [0005]FIG. 4 shows an example of a conventional electrical connection box  51  accommodating electrical component parts requiring to be fastened to distribution elements. The box  51  has a block body  52 , which may be a one-piece molding, an upper case  53  and a lower case  54 .  
           [0006]    A plurality of component receiving portions  55  are arranged on the upper face  52   a  of the block body  52 . At fastening locations  57  connection terminals  56   a  of a fusible link  56  of bolt-fastening type are fastened to bus bars  58  by bolts or the like. The fastening locations are on a body portion projecting up from the face  52   a  which has a socket  55   a  for receiving fusible links  56 . At the fastening locations  57  the insertion direction of a bolt or the like is shown by an arrow F in FIG. 4. Thus, the fastening portion  57  is open laterally with respect to the face  52   a  to enable the fastening to take place using a bolt or the like.  
           [0007]    The upper case  53  is installed on the block body  52  to cover the component part-installing surface  52   a . The lower case  54  is installed on the lower face of the block body  52 .  
           [0008]    However, in this known electrical connection box  51 , because the fastening location  57  extends toward the face  52   a , the bus bar  58  and the bolt fastened at the fastening location  57  are exposed to the exterior. Consequently, tools or other objects may contact the fastening location  57  during maintenance, which may cause shorting.  
         SUMMARY OF THE INVENTION  
         [0009]    Accordingly, it is an object of the present invention to provide an electrical connection box that can reduce risk of accidental contact of objects with a fastening location at which an electrical component part and a distribution element such as a bus bar are connected.  
           [0010]    According to the invention there is provided an electrical connection box including:  
           [0011]    a body having a face, the body carrying an electrically conductive power distribution element;  
           [0012]    a component receiving portion upstanding from the face of the body for receiving, in use, an electrical component and having a fastening location at which, in use, a connection terminal of the electrical component is fastened to the distribution element;  
           [0013]    a casing covering the face and the component receiving portion; and  
           [0014]    a removable cover covering the fastening location, the removable cover being enclosed within the casing.  
           [0015]    In the invention, the fastening location is covered by the cover. Thus, when the casing is removed from the body, the fastening location is not exposed. Accordingly, it is possible to reliably reduce the risk of tools or the like contacting the fastening location during maintenance.  
           [0016]    Preferably, the cover has an aperture through which the electrical component projects when installed. The periphery of the aperture may contact the installed electrical component or the component receiving portion.  
           [0017]    By this arrangement, the cover can be easily placed in position on the component receiving portion. Further, it is possible to reduce the risk of the installed cover slipping off from the component receiving portion.  
           [0018]    Thus the cover is guided by the contact of the periphery of the aperture with the component or the component receiving portion and can be placed in position easily and securely. The cover can be installed easily on the component receiving portion. Moreover, it is possible to reduce the risk of the installed cover being shaken or slipping off from the component receiving portion.  
           [0019]    Preferably the cover is located by a recess of the body. It may be locked releasably to the component receiving portion by snap-lock elements. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]    Embodiments of the invention will now be described by way of example with reference to the accompanying drawings, in which:  
         [0021]    [0021]FIG. 1 is an exploded perspective view of an embodiment of the electrical connection box of the present invention;  
         [0022]    [0022]FIGS. 2A and 2B are enlarged sectional views taken along the line A-A of FIG. 1, showing the cover of the fastening locations in two positions;  
         [0023]    [0023]FIG. 3 is a perspective view of the cover for the fastening locations of the box of FIG. 1; and  
         [0024]    [0024]FIG. 4 is an exploded perspective view of a known electrical connection box, described above. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0025]    As shown in FIG. 1, an electrical connection box  1  embodying the invention has a block body  2 , an upper case part  3  and a lower case part  4 , constituting a casing, and a cover  5  for the fastening locations. Each of these parts may be formed by molding of synthetic plastics material.  
         [0026]    Recesses  11  for receiving components, such as a fusible link, a relay, and/or the like, are formed on a surface  2   a  (in this case the upper face) of the block body  2 . Vertically standing bus bars  7  are accommodated in the block body  2 . A portion  12  of the body  2 , at which a connection terminal  6   a  of a fusible link  6  of bolt-fastening type is in use fastened to the bus bar  7  by a bolt or the like, projects upwards from the surface  2   a . The bus bar  7  is exposed where disposed on the surface  2   a.    
         [0027]    A recess  11   a  at which two fusible links  6  are received is formed above the portion  12 , surrounded by a wall  11   b . Each fusible link  6  has two connection terminal blades  6   a  each having a hole  6   b  for a bolt.  
         [0028]    As shown in FIGS. 2A and 2B, the upstanding portion  12  has recesses at which nuts  17  are received in a structure  13  which has a partitioning wall  14  and a pair of nut guides  15 . Nuts  17  are inserted into the structure  13 , which prevents rotation of each nut  17 . Slots  18  communicate with the recess  11   a  for insertion of the terminal blades  6   a  of the fusible link adjacent the nuts  17 .  
         [0029]    As shown by a two-dot chain line in FIGS. 2A and 2B, when the fusible links  6  are installed in the recess  11   a , the terminal blades  6   a  of each fusible link  6  are inserted into the respective slots  18 , between the nuts  17  and the bus bars  7 . Each terminal blade  6   a  thus contacts the adjacent nut  17  and the adjacent bus bar  7 . Bolts (not shown) are fastened into each respective nut  17  in the directions shown by arrows F in FIGS. 2A and 2B, and tightened to ensure tight connection of the terminal blades  6   a  and the bus bars  7 . Thus the portion  12  stands up from the surface  2   a  sufficiently to allow the terminal blades  6   a  and the bus bars  7  to be joined in this manner.  
         [0030]    With the block body  2  constructed as described above, the cover  5  is installed on the portion  12 . The cover  5  is approximately inverted U-shaped in a sectional view on a line B-B of FIG. 1. The cover  5  has a pair of opposed walls  5   a  and a top wall  5   b  connecting the walls  5   a  to each other. The cover  5  is installed on the portion  12  in the same direction (from above in FIG. 1) as that in which the fusible link  6  is installed in the recess  11   a.    
         [0031]    Two locking arms  21  are formed on each of the opposed walls  5   a , integrally (one-piece) with the respective wall  5   a . The outer surface of each arm  21  is formed flush with the outer surface of the wall  5   a . The arms  21  are spaced at predetermined intervals and are opposed to each other on the two sides of the cover  5 .  
         [0032]    As shown in FIGS. 2A and 2B, each arm  21  includes a locking nose  21   a  projecting toward the opposite wall  5   a  and a projection  21   b  projecting upward beyond the locking nose  21   a . As shown in FIG. 2B, as the cover  5  is installed on the upstanding portion  12 , the locking nose  21   a  slides in contact with an outer surface  12   a  of the portion  12  so that the arm  21  flexes outward. As shown in FIG. 2A, when the cover  5  has been fully installed on the portion  12 , the arm  21  returns to its original configuration, with the locking nose  21   a  engaged under a shoulder of the portion  12 . Further, the projection  21   b  contacts the outer surface  12   a  of the portion  12 . Thus, on each side of the portion  12 , the respective bus bar  7  and the bolt (not shown) are covered by the respective wall  5   a . The portion  12  is at least partly covered by the cover  5 .  
         [0033]    As shown in FIGS.  1  to  3 , the top wall  5   b  of the cover  5  has a rectangular aperture  22  through which the wall  11   b  is inserted. When the cover  5  is installed on the portion  12 , the edge surface around the aperture  22  contacts the outer surface of the wall  11   b.    
         [0034]    As shown in FIGS. 2A and 2B, guide surfaces  23  are formed adjacent the base of the portion  12  on the block body  2 , to form V-shaped notches. When the cover  5  is installed on the portion  12 , the lower ends of the walls  5   a  are accommodated in these notches, which are tapered to guide the lower ends of the walls  5   a , and correct any possible outward deformation of the lower portion of the cover  5 , as shown with arrows T in FIG. 2A. Further, the guide portion  23  reduces outward deformation of the wall  5   a  of the cover  5  when fully installed on the upstanding portion  12 .  
         [0035]    The upper case  3  is installed on the block body  2  in such a way that it covers the surface  2   a  (see FIG. 1). Thus the cover  5  is accommodated inside the upper case  3 . The lower case  4  is installed on the lower surface of the block body  2 .  
         [0036]    This embodiment provides the following effects:  
         [0037]    (1) The upstanding portion  12  at which the components  6  are mounted is covered by the cover  5 . Thus when the upper case  3  is removed from the block body  2 , the portion  12  is not exposed. Accordingly, it is possible to reliably reduce the risk of tools or the like contacting electrically live parts of the portion  12  during maintenance.  
         [0038]    (2) The cover  5  has an aperture  22  through which the wall  11   b  is inserted. Therefore, the cover  5  can be easily placed in the correct position on the portion  12 . This also helps to reduce the risk of the installed cover  5  slipping off the portion  12 .  
         [0039]    Further, the edges around the aperture  22  contact the outer surface of the wall  11   b  which has the effect of guiding the cover  5  so that it can be placed in its final position on the portion  12  easily and securely. Moreover, it is possible to reduce the risk of the installed cover  5  being shaken or slipping off the portion  12 .  
         [0040]    (3) The locking arms  21  of the cover  5  prevent the cover  5  from being removed from the fastening portion  12 .  
         [0041]    (4) The cover  5  is installed on the portion  12  in the same direction as the fusible link  6 . Therefore, even in the case where an electrical component part such as a relay is installed in the vicinity of the portion  12 , the cover  5  can be installed on the portion  12  without the cover  5  interfering with other electrical component parts.  
         [0042]    (5) When the cover  5  has been properly installed on the portion  12 , the outer surfaces of the locking arms  21  of the cover  5  are flush with the outer surfaces of the walls  5   a . If any of the locking arms  21  is not in correct engagement with the portion  12 , its outer surface projects from the outer surface of the wall  5   a . Thus it is easy to check whether the cover  5  has been completely installed on the portion  12 . That is, it is possible to reduce the risk of an incomplete installation of the cover  5  on the portion  12 .  
         [0043]    (6) The aperture  22  of the cover  5  is a rectangular hole, and the entire edge surface around the aperture  22  contacts the outer surface of the portion  11   a.  Therefore, it is very easy to place the cover  5  in correct position on the upstanding portion  12 . Further it is possible to reliably reduce the risk of the installed cover  5  being dislocated, e.g. by shaking.  
         [0044]    (7) The cover  5  is inverted U-shaped in section and sandwiches the portion  12  between its opposed walls  5   a . Thus the locking arms  21  and the portion  12  cannot be disengaged easily from each other, which reduces the risk the cover  5  being accidentally removed from the portion  12 .  
         [0045]    (8) The guide portions  23  are formed on the block body  2 . Thus, even if the cover  5  deforms outward, the guide portions  23  correct the deformation. Further the guide portions  23  reduce outward deformation of the walls  5   a  of the cover  5  installed on the upstanding portion  12 .  
         [0046]    The above-described embodiment of the present invention described above may be modified in many ways, e.g. as described below.  
         [0047]    In the above-described embodiment, bus bars are used as the distribution elements, but electric wires may be used instead as the distribution elements.  
         [0048]    The aperture  22  of the cover  5  does not necessarily have to contact the wall  11   b . That is, the aperture  22  does not necessarily have to be larger than the contour of the wall  11   b.    
         [0049]    In the above-described embodiments, the aperture  22  of the cover  5  contacts the outer surface of the portion  11   a , but instead the aperture  22  may be so formed that its periphery contacts the outer surface of the fusible link  6 . In a case where the portion  11   a  does not have the wall  11   b , i.e. the fusible link  6  is installed in an exposed state, it is easy to place the cover  5  in position.  
         [0050]    The aperture  22  of the cover  5  is rectangular in the above-described embodiment, but may be circular or the like, provided that it has the same configuration as the outside of the portion  11   a . Further, the wall of the aperture  22  may be cut away at a portion P shown with oblique lines in FIG. 1, so that the aperture  22  is open laterally.  
         [0051]    The number of the locking arms  21  of the cover  5  is not limited to four, but may be three or less or five or more. The configuration of the locking arm  21  is not limited to a particular one, but any configuration can be adopted, provided that it can lock to the portion  12 .  
         [0052]    The guide portions  23  may be omitted.  
         [0053]    The electrical component part installed in the manner shown is not limited to the fusible link, but it is possible to use other electrical component parts such as a relay having a connection terminal required to be fastened with a bolt.  
         [0054]    The cover  5  is installed on the portion  12  in the same direction as the direction in which the fusible link  6  is installed in the recess  11   a  in the embodiment, but the cover  5  may be installed on the portion  12  laterally. In this case, it is necessary to alter the configuration of the aperture.  
         [0055]    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.

Technology Classification (CPC): 8