Abstract:
An accommodation block for connection of electrical components is mounted in an electrical connection box, e.g. of a vehicle. In the vicinity of each lengthwise end of side walls of the block body, there is formed an insertion guide extending downward from an upper end connected with the upper edge of the side wall. The guides are received in engagement elements of the box. The lower ends of the insertion guides are located below the lower end of the block body to improve visual observation during insertion into the box. A clamp is arranged below the block body. A protection rib for protecting the clamp is extended down from the lower end of one side wall.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an accommodation block which accommodates electrical connectors for connection with electrical components such as wire harnesses, electrical and electronic circuits, electrical and electronic component parts and the like and which in use is mounted in an electrical connection box. The invention further relates to the electrical connection box, including the accommodation block mounted in it, and more particularly to an electrical connection box for a vehicle such as an automobile. 
     2. Description of the Related Art 
     Various electrical and electronic circuits, electrical and electronic component parts, and the like are installed inside a vehicle. An electrical connection box is used to accommodate these electrical and electronic component parts and as a connection branch point for wires such as wire harnesses. 
     Generally, in an electrical connection box, in order to facilitate assembly and safe storage, connectors of various electrical and electronic component parts and wire harnesses and the like are accommodated inside respective accommodation blocks, depending on kind or function. The accommodation blocks are themselves mounted in the electrical connection box at predetermined respective positions. 
     A conventional electrical connection box of this type will be described below with reference to FIGS. 10 and 11. This box is similar to that shown in Japanese Utility Model Unexamined Publication No. 63-194053. In this box and according to an embodiment of the present invention described later, the electrical connection box is described with a relay block as the accommodation block, but the same principle is applicable to other accommodation blocks. 
     As shown in FIGS. 10 and 11, a relay accommodation block  52  is accommodated inside a lower case  51  constituting an electrical connection box  50 . The block  52  comprises a block body  53  formed in the shape of an approximately rectangular hollow body. A relay  55  is installed on each of four relay housings  54  formed in an upper portion of the block body  53 . 
     In the vicinity of each lengthwise end of each side wall  56  of the block body  53 , an insertion guide  57  is formed extending downward from its upper end portion which is connected with the upper edge of the side wall  56 . Each insertion guide  57  has a shape approximately of an inverted “L” from a side view and rectangular from a front view. The lower end of each insertion guide  57  is level with the lower end of the block body  53 . A gap C 1  is formed between the back surface of each insertion guide  57  and the side wall  56 . A reinforcing rib  58  connecting the insertion guide  57  and the side wall  56  with each other is formed vertically in the gap C 1 . 
     On each of the side walls  56 , a pair of substantially V-shaped locking pieces  59  are formed adjacent insertion guides  57 . Each of the locking pieces  59  comprises a base portion  59   a  fixed to the side wall  56  and a flexible portion  59   b  deformable toward the base portion  59   a . A locking projection or nose  59   c  projecting toward the insertion guide  57  is formed in the vicinity of the upper end of the flexible portion  59   b.    
     The lower case  51  is box-shaped and its upper part is open, thus having side walls  60   a  and  60   b  opposed to each other. Two engaging portions  61  are formed on the inner surface of each of the side walls  60   a  and  60   b . Each engaging portion  61  is formed at a position corresponding to the position of each insertion guide  57  of the relay accommodation block  52 . Recess portions  62  into which the insertion guides  57  can be inserted downwardly are formed in the engaging portions  61 . A projecting nose  64  is formed on the upper end of a wall  63  of one engaging portion  61  and on the upper end of a wall  63  of the adjacent engaging portion  61 . Each nose  64  is formed at a position corresponding to the position of the locking nose  59   c  of each locking piece  59  of the relay block  52 . 
     An operator assembles the block  52  having the above-described construction inside the lower case  51 . The operator inserts the block  52  into the lower case  51  downwardly by holding the relay housing  54  of the relays  55  or the side wall  56  of the relay block  52 . At this time, the operator inserts each insertion guide  57  into the corresponding recess portion  62  of each engaging portion  61 . This can be done with visual observation by the operator, thus locating the block  52  in position. As the operator inserts each insertion guide  57  further into the corresponding recess portion  62 , the flexible portion  59   b  of each locking piece  59  is pressed by the nose  64  of each engaging portion  61  and thus deformed toward the base portion  59   a . Then, simultaneously with contact between the lower surface  57   a  of the fixed upper end portion of each insertion guide  57  and the upper surface of the corresponding engaging portion  61 , each of the deformed flexible portions  59   b  is released by the respective nose  64 . Consequently, the locking nose  59   c  formed at the upper end of the flexible portion  59   b  engages under the nose  64 . In this manner, the operator positions the relay block  52  in a locked position inside the lower case  51 , thus completing the assembly operation. 
     However, during construction of the conventional block  52  and lower case  51 , when the operator inserts each insertion guide  57  into the corresponding recess portion  62  of the engaging portion  61 , the position of the operator&#39;s hands, which hold the relay block  52  and the block body  53 , make it difficult for the operator to easily view all the insertion guides  57 . Therefore, the operator has the task of inserting each of the insertion guides  57  into the corresponding recess portion  62  which becomes complicated. Thus, installing the relay block  52  to the lower case  51  is troublesome, and there is a risk of mis-fitting. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing problems in the conventional structures, it is an object of the present invention to provide an accommodation block which can be easily installed on a box, and further to provide an electrical connection box accommodating this accommodation block. 
     According to the invention, there is provided an accommodation block for an electrical connection box, comprising a block body having opposite first and second side walls having lower edges; electrical connectors in the block body, for making electrical connection with electrical components; a plurality of insertion guide members which have upper ends fixedly connected to respective upper regions of the side walls of the block body and extend downwardly from the upper ends to lower ends thereof, which are located below the lower edges of said side walls. 
     The electrical connectors in the block body may be, for example, connectors of one or more wiring harnesses, or connectors which are fixed in the block. The electrical components which, in use, may be mounted in or on the block body may be electrical or electronic devices of any kind, relays being one example. 
     Preferably, the accommodation block of the invention has a clamp for holding at least one wire harness. The clamp is strip-shaped and has a first end connected hingedly with the first side wall of the block body and a second end remote from the first end. The block body has receiving means for receiving and holding the second end of said clamp, the receiving means being located adjacent to the second side wall of the block body. The block body further has a protection wall extending downwardly from the lower edge of the second side wall adjacent the receiving means so as to provide lateral protection of the clamp. 
     According to another aspect, the invention provides an electrical connection box comprising an accommodation block of the invention as described above, and a casing having opposite first and second side walls having on their respective opposed surfaces a plurality of engagement elements for respectively engaging the insertion guide members of the accommodation block. The accommodation box is mounted in casing with engagement of the insertion guides with the engagement elements. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The exemplary embodiments of the invention will be described in detail, with reference to the following figures in which: 
     FIG. 1 is an exploded perspective view showing an accommodation block and an electrical connection box accommodating the accommodation block according to a first embodiment of the present invention; 
     FIG. 2 is a front view showing the accommodation block and the electrical connection box of FIG. 1; 
     FIG. 3 is a plan view showing the accommodation block and the electrical connection box of FIG. 1; 
     FIG. 4 is a sectional view taken along line A—A of FIG. 2; 
     FIG. 5 is an enlarged view of a portion of the accommodation block and connection box according to the embodiment of FIG. 1; 
     FIG. 6 is an enlarged sectional view of a portion of the accommodation block of the embodiment of FIG. 1; 
     FIG. 7 is an enlarged view of a portion of an accommodation block according to a second embodiment of the invention; 
     FIG. 8 is an enlarged view of a portion of an accommodation block according to another embodiment of the invention; 
     FIG. 9 is a plan view of an accommodation block according to another embodiment of the invention; 
     FIG. 10 is an exploded perspective view showing a conventional accommodation block and a conventional electrical connection box accommodating the accommodation block; and 
     FIG. 11 is a front view showing the conventional accommodation block and electrical connection box of FIG.  10 . 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     A first embodiment of the present invention will be described with reference to FIGS. 1 to  6 . Parts corresponding to parts of the conventional electrical connection box shown in FIGS. 10 and 11 are denoted by the same reference numerals, and a detailed description of these parts is not repeated herein. 
     As shown in FIGS. 1 and 2, a relay accommodation block  12  is accommodated inside a lower case  11  constituting an electrical connection box  10 . The block  12  comprises a block body  13  formed in the shape of an approximately rectangular hollow body. A relay  55  is installed on each of four relay housings  54  formed in the block body  13 . 
     In the vicinity of each lengthwise end of each of opposite side walls  14   a ,  14   b  of the block body  13 , there is formed an insertion guide  15  extending downward from its upper end portion which is fixedly connected with the upper edge of the respective side wall  14   a ,  14   b . That is, two insertion guides  15  are formed on each of the side walls  14   a ,  14   b . As shown in FIG. 3, the insertion guides  15  formed on the respective side walls  14   a , 14   b  at one end of the body  13  are precisely opposite each other, and the same is true at the other end of the body  13 . Each insertion guide  15  has a shape of an approximately inverted “L” in side view and is rectangular in front view. The lower end of the insertion guide  15  is below the lower end of the block body  13 , by an amount which is at least  25 % of the overall height of the side wall  14   a ,  14   b  covered by the insertion guide  15 . A gap C 1  is formed between the back surface of each insertion guide  15  and the respective side wall  14   a ,  14   b . A reinforcing rib  16  connecting each of the insertion guides  15  and each of the side walls  14   a ,  14   b  with each other is formed vertically in the gap C 1 . In each guide  15 , the reinforcing rib  16  extends to the lower end of the guide  15 . The reinforcing rib  16  increases the strength of the insertion guide  15 , thus reducing risk of it being damaged or deformed. 
     As shown in FIG. 4, inside the block body  13  and in the vicinity of the side wall  14   b , there is formed a clamp receiving means in the form of a latching portion  17  having a latching nose  17   a  thereon. A corresponding clamp  19  is arranged below the block body  13 . The clamp  19  is strip-shaped and has a first end  19   a  connected with the lower edge of the side wall  14   a  of the block body  13  through a hinge  18  and a second free end  19   b  having a latching recess portion  19   c  in which latching nose  17   a  of the block body  13  fits. A protection plate or rib  20  extends from the lower end of the side wall  14   b  in the vicinity of the latching portion  17 . 
     The clamp  19  holds wire harnesses (not shown in the drawing) electrically connected with terminals (not shown in the drawing) of the relays  55  by sandwiching them. Thus, it is possible to restrict the run direction of the wire harnesses to a predetermined direction and prevent them from twining with each other or prevent them from being installed alongside other kinds of wires. Further, when the free end  19   b  of the clamp  19  is fitted in the latching portion  17  of the block body  13 , the clamp  19  is protected by the protection rib  20 . Accordingly, when an external force is applied to the clamp  19  during storage of the relay block  12 , the clamp is protected from being deformed or damaged. 
     As shown in FIGS. 1 and 2, the lower case  11  is box-shaped and its upper part is open, thus having side walls  21   a  and  21   b  opposed to each other. Two engaging portions  22  are formed on the inner surface of each of the side walls  21   a  and  21   b . Each engaging portion  22  is formed at a position corresponding to the position of one of the four insertion guides  15  of the relay block  12 . A recess portion  23  which guides the corresponding insertion guide  15  when inserted into it downwardly is provided in each engaging portion  22 . A projection nose  25  is formed on the upper end of a wall  24  of one engaging portion  22  and on the upper end of the opposed wall  24  of the adjacent engaging portion  22 . Each projection nose  25  is formed at a position corresponding to the position of a locking nose  59   c  formed at the upper end of each locking piece  59  of the block  12 . 
     The relay accommodation block  12  having the above-described construction of FIGS. 1 to  6  is accommodated in the lower case  11  in a manner similar to that of the conventional construction. It is to be noted that according to this embodiment of the invention, the lower end of each of the insertion guides  15  is located below the lower end of the block body  13  by a predetermined amount. Thus, after each insertion guide  15  is inserted into the corresponding recess portion  23  by the predetermined length, the block  12  is accommodated in the lower case  11 . 
     An operator inserts each insertion guide  15  into the corresponding recess portion  23  with visual observation, to locate the relay block  12  in position. At this time, the operator can easily see the insertion of the lower end of each of the insertion guides  15  into the recess portion  23  of the corresponding engaging portion  22 . 
     Then, the operator fully inserts each insertion guide  15  into the corresponding recess portion  23  to accommodate the relay block  12  inside the lower case  11 . As a result, the flexible portion  59   b  of each locking piece  59  is pressed by the projection nose  25  of the respective engaging portion  22  and deformed toward the base portion  59   a . Then, simultaneously with the contact between the lower surface  15   a  of the fixed upper end portion of each of the insertion guides  15  and the upper surface of each of the engaging portions  22 , each of the deformed flexible portions  59   b  is released by the corresponding projection nose  25 . Consequently, as shown in FIGS. 5 and 6, the locking nose  59   c  of each of the flexible portions  59   b  engages the corresponding projection portion  25 . Owing to the engagement between each locking nose  59   c  and the corresponding nose  25 , the relay block  12  is locked in position inside the lower case  11 . In this state, because the lower surface  15   a  of the fixed upper end portion of each insertion guide  15  contacts the upper surface of the engaging portion  22 , the block  12  is prevented from moving further into the lower case  11 . 
     Accordingly, the block  12  is prevented from vertical movement. Further, because each insertion guide  15  is inserted into the corresponding recess portion  23 , the relay block  12  is prevented from being loose horizontally. In FIG. 6, two-dot chain lines show the line of sight through the insertion guide and broken lines show the line of sight through each engaging portion  22 . 
     As described above in detail, the following effects can be obtained by this embodiment: 
     (1) The operator can view the insertion of each of the insertion guides  15  into the corresponding recess portion  23  at a glance when assembling the relay block  12  inside the lower case  11 . Thus, the operator can easily place the relay block  12  in position inside the lower case  11 . That is, the construction according to this embodiment improves reliability of installation of the relay block  12  on the lower case  11 . 
     Further, it is possible to accommodate the relay block  12  inside the lower case  11  vertically and horizontally without looseness. 
     (2) The clamp  19  is capable of holding wire harnesses (not shown in the drawing) electrically connected with terminals (not shown in the drawing) of each of the relays  55  by sandwiching them. Thus, it is possible to restrict the extension direction of the wire harnesses to a predetermined direction and prevent them from twining with each other or prevent them from being installed alongside other kinds of wire. Further, the clamp  19  is protected by the protection rib  20 . Accordingly, when an external force is applied to the clamp  19  during storage of the relay block  12 , the clamping mechanism  17  can be prevented from being deformed or damaged. 
     (3) Because the reinforcing rib  16  is formed on each of the insertion guides  15 , the insertion guides  15  can be suitably prevented from being damaged or deformed. 
     Modifications of this embodiment are possible. For example: 
     According to the present embodiment, the number of the insertion guides  15  and the corresponding engaging portions  22  is four, however, this number may be increased or decreased. 
     In the embodiment, the reinforcing ribs  16  formed between the insertion guides  15  and the block body  13  extend to the lower end of the insertion guides  15 . But as shown in FIG. 7, this reinforcing rib may be altered to form a reinforcing rib  31 , which extends only to the lower end of the block body  13 . 
     As shown in FIG. 8, the lower end of each insertion guide  15  may be tapered to facilitate the operation of inserting the insertion guide  15  into the corresponding recess portion  23 . 
     As shown in FIG. 3, the insertion guide  15  formed on the side wall  14   a  and that formed on the side wall  14   b  are opposed to each other. But as shown in FIG. 9, the insertion guide  15  formed on the side wall  14   a  and the insertion guide  15  formed on the side wall  14   b  may be shifted from each other in the length direction of the block body  13  to securely prevent the operator from inserting the block  12  in the lower case  11  with the front and back sides of the block  12  in the incorrect reversed position. 
     As shown in FIGS. 2 and 4, according to an embodiment of the invention, the lower end of the protection rib  20  is located below the lower ends of the insertion guides  15 , however, the lower ends of the insertion guides  15  may be positioned at the same level as that of the protection rib  20  or below that of the protection rib  20 . 
     While the invention has been described in conjunction with the preferred embodiments as described above, it is evident that many alternatives, modifications and variations are apparent to those skilled in the art. Accordingly, the preferred embodiments in the invention set forth above are intended to be illustrative and not limiting. Various changes may be made without departing from the spirit and scope of the invention.