Patent Publication Number: US-6341967-B1

Title: Connector block for injector

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a connector block which can be connected to an injector (a fuel injection valve) for use in an automobile. 
     2. Description of the Related Art 
     Now, FIG. 1 shows an example of the outer shape of a connector block  10  for an injector (which is hereinafter referred to as a connector block  10  simply). This connector block  10  is a device which is to be mounted into, for example, a V-type  6 -cylinder engine (not shown); and, the connector block  10  comprises a housing  21  formed of heat resistant reinforced hard resin so as to have an elongated shape and also, conventionally, a group of bus bars  1  which are shown in FIG.  15 . 
     By the way, referring to the structure of a V-type engine, a plurality of (for example, six) cylinders arranged along a crankshaft are inclined right and left every other cylinder to thereby provide a pair of cylinder groups and, as shown in FIG. 2, a plurality of injectors  51  (for example, by threes in each cylinder group) are projected obliquely upward from the two cylinder heads H, H of these right and left cylinder groups toward the centers of the two cylinder heads H, H. Here, in FIG. 2, of the two injector groups  50 A,  50 B respectively projected from the two cylinder heads H, H, there are shown two injectors  51 ,  51 , that is, one injector in each injector group. 
     Now, the connector block  10 , as shown in FIG. 2, includes, on the lower surface  21 D of the housing,  21 , a pair of injector connecting portion groups  25 A,  25 B to which the injector groups  50 A,  50 B can be respectively connected and, on the upper surface  21 U of the housing  21 , a wire connecting portion  22  to which an external wire  80 , shown in FIG.  1 . can be connected. And, the bus bar group  1  (see FIG. 15) extend over the individual injector connecting portions  25  of the respective injector connecting portion groups  25 A,  25 B as well as the wire connecting portion  22 . Also, in the bus bar group  1 , there are disposed a plurality of tabs  31  to be exposed in the respective injector connecting portions in such a manner that they are divided into a pair of tab groups  31 A,  31 B (see FIG. 15) respectively facing in obliquely downward directions which are different from each other. 
     By the way, as described above, since the bus bar group  1  includes the tab groups  31 A,  31 B which respectively face in the mutually different directions, to mold the housing  21 , it is necessary to use a metal mold including such a slide mold  3  as shown in FIG. 17, or a metal mold including such a core  5  as shown in FIG.  18 . 
     However, conventionally, for the following reason, there is no choice but to use a metal mold including a core  5  which is poor in operation efficiency. That is, in the conventional bus bar group  1 , a grounding bus bar  8  shown in FIG. 16 is structured such that a pair of main body portions  8 S,  8 S thereof including a plurality of tabs  31  in correspondence to the respective injector connecting portion groups  25 A,  25 B are connected together through a horizontal branch portion  8 H thereof; and, the grounding bus bar  8  and other power supply bus bars  9 , as shown in FIG. 15, are unified by a holder  63  formed of synthetic resin, thereby forming one bus bar group  1 . For this reason, as shown in FIG. 17, the two tab groups  31 A,  31 B differing in the facing direction are unified and thus cannot be inserted into a tab hold hole  4  formed in the slide mold  3 , which makes it impossible to set the bus bar group  1  into the metal mold including the slide mold  3 . By the way, even in case where the slide mold  3  is retreated once, the bus bar group  1  is set into the metal mold and, after then, the slide mold  3  is inserted again, because the leading end of the tab  31  is not positioned, the tab  31  cannot be inserted into the tab hold hole  4  of the slide mold  3 , either. 
     Therefore, conventionally, as shown in FIG. 18, there is no choice but to use the metal mold including the core  5 . Specifically, to mold the housing  21 , there must be carried out the following extremely troublesome operations: that is, firstly, the core  5  is mounted on the bus bar group  1  (see FIG.  18 ); and, after then, the bus bar group  1  together with the core  5  is set into a metal mold main body  6 , a product is taken out from the metal mold after the housing  21  is molded, and the core  5  is removed from the product. 
     SUMMARY OF THE INVENTION 
     The present invention aims at eliminating the drawbacks found in the above-mentioned conventional connector block for an injector. Accordingly, it is an object of the invention to provide a connector block for an injector which allows a bus bar group to be set in a metal mold including a slide mold and thus can be manufactured with high efficiency. 
     In attaining the above object, according to a first aspect of the invention, there is provided a connector block for an injector, comprising a housing molded by setting a bus bar group in a metal mold for resin molding, the housing including a wire connecting portion for connection with an external wire and a pair of injector connecting portion groups disposed in the lower surface of the housing for connection with a plurality of injectors from mutually different oblique downward directions, the bus bar group extending over the respective injector connecting portions and wire connecting portion, wherein the bus bar group is set in the metal mold while the bus bar group is divided into a pair of subordinate bus bar groups in correspondence to the pair of injector connecting portion groups, and the subordinate bus bar groups respectively include branched bus bars branched from the wire connecting portions and extending to the respective injector connecting portions, and also wherein the branched bus bars disposed in the two subordinate bus bar groups include a pair of short-circuit tabs to be conduction connected with each other by an external wire or by a short-circuit terminal. 
     Also, according to a second aspect of the invention, in a connector block for an injector as set forth in the first aspect of the invention, the housing further includes a recessed formed terminal storing recess, the pair of short-circuit tabs are erected from the bottom surface of the terminal storing recess, the short-circuit terminal for conduction connecting together the pair of short-circuit tabs is stored in the terminal storing recess, and only one of the pair of short-circuit tabs is connected to the external wire. 
     Further, according to a third aspect of the invention, in a connector block for an injector as set forth in the first or second aspect of the invention, the subordinate bus bar groups are respectively composed of a plurality of bus bars which are held together by a holder formed of synthetic resin. 
     According to the first aspect of the invention, by dividing the bus bar group into the pair of subordinate bus bar groups, the end portions of the bus bar group extending in mutually different directions in correspondence to the pair of injector connecting portion groups can be held separately in the metal mold. Thanks to this, the bus bar group can be set in the metal mold including a slide mold, which makes it possible to manufacture a connector block for an injector with high efficiency. Also, in the case of the branched bus bars of the respective subordinate bus bar groups, the pair of short-circuit tabs disposed in the branched bus bars can be conduction connected with each other by an external wire or by a short-circuit terminal, whereby the branched bus bars can be short-circuited. 
     According to the second aspect of the invention, since the number of tabs composed of the branched bus bars and conduction connectable together by the external wire is set equal to the number of tabs in the conventional connector, as a mating-side connector to be connected to the wire connecting portion, the conventional connector as it is can be used. 
     According to the third aspect of the invention, in the subordinate bus bar groups, a plurality of bus bars are held together by a holder. Therefore, when compared with a structure in which bus bars are not held by a holder, the structure according to the invention is improved in the handling efficiency. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a first embodiment of a connector block according to the invention as well as a conventional connector block. 
     FIG. 2 is a section view of the connector block shown in FIG.  1 . 
     FIG. 3A is a perspective view of a plurality of bus bars incorporated in the connector block, according to the first embodiment of the invention. 
     FIG. 3B is a perspective view of the plurality of bus bars when they are divided into two subordinate bus bar groups, according to the first embodiment of the invention. 
     FIG. 4 is a perspective view of a pair of subordinate bus bar groups, according to a first embodiment of the invention. 
     FIG. 5 is a perspective view of the pair of subordinate bus bar (groups, showing a state in which they are connected together, according to a first embodiment of the invention. 
     FIG. 6 is a side section view to show a state in which the two subordinate bus bar groups are set into a metal mold while they are separated from each other. 
     FIG. 7 is a side section view to show a state in which the metal mold is closed. 
     FIG. 8 is a side section view to show a state in which a slide mold is retreated. 
     FIG. 9 is a side section view to show a state in which a product is removed from a metal mold main body. 
     FIG. 10 is a perspective view of a plurality of bus bars according to a second embodiment of the invention. 
     FIG. 11 is a perspective view of a pair of subordinate bus bar groups. 
     FIG. 12 is a perspective view of the pair of subordinate bus bar groups, showing a state in which they are connected together. 
     FIG. 13 is a perspective view of a short-circuit terminal and a terminal storing recess. 
     FIG. 14 is a perspective view to show a state in which the short-circuit terminal is stored in the terminal storing) recess. 
     FIG. 15 is a perspective view of conventional bus bar group. 
     FIG. 16 is a perspective view of a plurality of conventional bus bars. 
     FIG. 17 is a side section view to show when setting the conventional bus bar group into a metal mold. 
     FIG. 18 is a side section view to show a state in which a core is mounted into the conventional bus bar group. 
    
    
     DETAILED DESCRIPTION OF THE PRESENT INVENTION 
     First Embodiment 
     Now, description will be given below of a first embodiment of a connector block for an injector according to the invention with reference to FIGS. 1 to  9 . A connector block  20  according to the present embodiment, as shown in FIG. 1, is substantially the same in the outer shape as the conventional connector block  10  and is to be coupled to the previously described injector  51  provided in the V-type engine. In the present embodiment, parts thereof, which are the same in structure as those employed in the conventional connector block, are given the same designations and thus will be described just supplementarily, whereas description will be given in detail of differences between the present embodiment and the conventional connector block. 
     Firstly, describing the structure of the injector  51  supplementarily with reference to FIG. 2, a plug portion  53  is projected laterally from the near-to-upper-end position in FIG. 2 of a cylindrical-shaped injector main body  52 , and a pair of terminal pieces  54  (in FIG. 2, only one terminal piece  54  is shown) are erected upwardly from the plug portion  53  in parallel to the injector main body  52 . And, when a voltage is applied between the two terminal pieces  54 , a solenoid valve disposed in the interior portion of the injector main body  52  can be opened; and, normally, the solenoid valve is closed. 
     Here, supplementary description will be given of the housing  21  of the connector block  20  shown in FIG.  2 . That is, as shown in FIG. 1, in the housing  21 , there is formed a fuel supply passage  21 C which extends in the longitudinal direction of the housing  21 ; and, fuel is supplied to the fuel supply passage  21 C. Also, the housing  21  further includes a wire connecting portion  22 ; the wire connecting portion  22  has a hood wall  23  which stands erect upwardly from the housing  21  and has an elliptical-shaped cross section; and, a plurality of tabs  24  stand erect from the deeper-side surface of the hood wall  23 . 
     And, the housing  21  further includes injector connecting portions  25  formed on the lower surface of the housing  21 . Each of the injector connecting portions  25  includes a pipe hole  26  and a plug receiving portion  27  in a paired manner. Specifically, the pipe hole  26  communicates with the fuel supply passage  21 C, while the injector main body  52  can be coupled to the pipe hole  26 ; and, to the plug receiving portion  27 , there can be coupled the plug portion  53  formed in the injector  51 . Each plug receiving portion  27  is composed of a first chamber  28  formed on the opening side thereof and a second chamber  29  formed on the deeper side thereof. Also, in the second chamber  29 , there are stored a pair of relay terminals  30  (in FIG. 2, only one relay terminal  30  is shown) side by side in an insulated manner. A pair of tabs  31  (in FIG. 2, only one tab  31  is shown) are projected from the deeper side of the second chamber  29 , while these tabs  31  are respectively inserted into the one-end portions of the associated relay terminals  30  and are thereby connected to the relay terminals  30 . And, a waterproof pillar  55  disposed in the plug portion  53  is fitted into the first chamber  28  in sealed manner, while the terminal pieces  54  projecting from the waterproof pillar  55  are respectively inserted into the other-end portions of the associated relay terminals  30  and are thereby connected to the relay terminals  30 . 
     The structure of the present connector block  10  described heretofore is similar to that of the conventional connector block  10 . 
     Now, FIG. 3A shows all bus bars of a bus bar group  65  embedded in the housing  21  in such a manner that they are compared with those of the conventional bus bar group  1  shown in FIG.  16 . 
     The present bus bar group  65  is composed of a plurality of power supply bus bars  9  identical with the conventional bus bars and grounding bus bars  60  different from the conventional bus bars. The power supply bus bars  9 , similarly to the conventional bus bars, are disposed in the same number as the injector connecting portions  25  and are insulated from each other: the one-end portions of the respective power supply bus bars  9  provide the above-mentioned tabs  24  that are collected together in the wire connecting portion  22  and are exposed there; and, the other-end portions of the respective power supply bus bars  9  form one of a pair of tabs  31 ,  31  disposed in each of the injector connecting portions  25 . 
     Referring to the grounding bus bars  60 , a total of two grounding bus bars are disposed: that is, one grounding bus bar  60  in one group  25 A of the pair of injector connecting portion groups, one grounding bus bar  60  in the other group  25 B. Each grounding bus bar  60  includes a plurality of branch portions which project obliquely downward from a plurality of positions of the main body portion  61  of the grounding bus bar  60 , while the main body portion  61  extends along the longitudinal direction of the housing  21 . These branch portions form the remaining one of the pair of tabs  31 ,  31 . Also, the two grounding bus bars  60  respectively include branch portions  61 S which project from the intermediate portions of their respective main body portions  61  and approach each other; the leading ends of the branch portions  61 S are bent upwardly at right angles; and, the leading ends of the right-angle bent portions form short-circuit tabs  24 S of the tabs  24  exposed in the wire connecting portion  22 , respectively. 
     The bus bar group  65 , as shown in FIG. 3B, can be divided into two subordinate bus bar groups  65 A and  65 B which correspond to the pair of injector connecting portion groups  25 A and  25 B. And, to manufacture these subordinate bus bar groups  65 A and  65 B, they may be set in a metal mold for primary molding and a plurality of synthetic resin holders  62 ,  63 ,  63 , - - - shown in FIG. 4 may be insert molded, thereby producing a structure in which a plurality of bus bars are collected together and held in an insulated manner. The details of this structure are as follows. That is, the two subordinate bus bar groups  65 A and  65 B are structured such that, as shown in FIG. 4, from the intermediate portions of the rail portions  66  thereof extending along the longitudinal direction of the housing  21 , there are projected horizontal holders  62  in such a manner as to approach each other. Also, from the plurality of positions of the respective rail portions  66 , there are projected the above-mentioned pair of tabs  31 ,  31 ; and, the above-mentioned plurality of tabs  24  extend upwardly from the respective horizontal holders  62 . Further, the short-circuit tabs  24 S,  24 S are situated on the leading end sides of the respective horizontal holders  62 ,  62  and adjoin each other. 
     Next, while explaining the steps of manufacturing the connector block  20  according to the present embodiment, description will be given below of the operation of the present embodiment. 
     Firstly, the plurality of bus bars shown in FIG. 3A are set in the primary molding metal mold and are then collected together into the holders  62 ,  63  in the above-mentioned manner to thereby provide the pair of subordinate bus bar groups  65 A and  65 B shown in FIG.  4 . 
     Next, the two subordinate bus bar groups  65 A and  65 B are separated from each other and, as shown in FIG. 6, they are respectively set in a metal mold  75  including a slide mold  3 . 
     Specifically, the subordinate bus bar group  65 B shown on the left in FIG. 6 is moved right and downward in FIG. 6 (see an arrow mark V shown in FIG. 6) to insert the tab  31  into a tab hold hole  4  formed in the slide mold  3 , while the subordinate bus bar group  65 A shown on the right in FIG. 6 is moved left and downward in FIG. 6 (see an arrow mark W shown in FIG. 6) to insert the tab  31  into a tab hold hole  4  formed in the other slide mold (not shown), whereby the two subordinate bus bar groups  65 A and  65 B are set in the metal mold  75 . And, as shown in FIG. 7, the metal mold  75  is closed and synthetic resin is filled into the interior portion of the metal mold  75 . As a result of this, the pair of subordinate bus bar groups  65 A and  65 B are covered with the housing  21 . 
     Next, as shown in FIG. 8, the slide mold  3  is retreated; as shown in FIG. 9, the connector block  20  is removed in the mold opening direction of the metal mold  75 ; and, further, a metal mold  75 A for molding the fuel supply passage  21 C of the connector block  20  is pulled out. And, finally, the relay terminal  30  (see FIG. 2) is inserted into the injector connecting portion  25 , which completes the connector block  20 . 
     When the completed connector block  20  is connected to an external wire  80 , shown in FIG. 1, the short-circuit tabs  24 S,  24 S extended from the pair of grounding bus bars  60  are short-circuited by the external wire  80 . 
     As described above, according to the present embodiment, since the bus bar group  65  can be set in the metal mold including the slide mold  3  while the bus bar group  65  is separated into the pair of subordinate bus bar groups  65 A,  65 B, when compared with the conventional connector block manufacturing method using a core, the connector block  20  can be manufactured with high efficiency. Also, because the subordinate bus bar groups  65 A,  65 B are structured such that a plurality of bus bars are held by the holders  62 ,  63 , when compared with a structure different from this, the subordinate bus bar groups  65 A,  65 B can be handled easily thereby be able to enhance the efficiency of the operation to set the bus bar group  65  into the metal mold. 
     Second Embodiment 
     Now, FIGS. 10 to  14  show a second embodiment of a connector block according to the invention. The present embodiment is different from the previously described first embodiment in the structure for short-circuiting a pair of grounding bus bars. In the present embodiment, parts thereof identical in structure with those of the first embodiment are given the same designations and the duplicate description thereof is omitted; and, description will be given below only of the portions thereof different in structure from the first embodiment. 
     A plurality of bus bars according to the present embodiment are shown in FIG.  10 . Specifically, one grounding bus bar  60 A, similarly to the first embodiment, includes a short-circuit tab  24 S projected upwardly, whereas the other grounding bus bar  60 B includes a subordinate short-circuit tab  24 T which is shorter than the short-circuit tab  24 S and is projected upwardly. 
     These short-circuit tabs  24 S,  24 T, as shown in FIG. 11, are projected upwardly from the leading ends of the horizontal holders  62 A,  62 B of the respective subordinate bus bar groups  65 A,  65 B, respectively. 
     Also, the subordinate short-circuit tab  24 T is shifted from the arranging direction of tab groups  24  respectively formed of power supply bus bars  9  of the horizontal holder  62 B and is also positioned nearer to the leading end side of the horizontal holder  62  than the tab groups  24 . Also, the portion of the horizontal holder  62 B where the subordinate short-circuit tab  24 T is disposed is formed as a projecting portion  62 C which projects toward a mating-side horizontal holder  62 A. And, in case where the subordinate bus bar groups  65 A,  65 B are set in a metal mold, as shown in FIG. 12, the projecting portion  62 C is superimposed on top of the longitudinal-direction front portion of the subordinate bus bar group  65 A. Due to this, the short-circuit tab  24 S can be situated in the center of the plurality of tab groups  24  formed of the power supply bus bars  9 , and the subordinate short-circuit tab  24 T can be positioned adjacently to and in front of the short-circuit tab  24 S. 
     Also, as shown in FIG. 13, in the wall surface of the housing  21  where the short-circuit tabs  24 S,  24 T of the wire connecting portion  22 , there are recessed formed a terminal storing recess  70  having a rectangular-shaped section; the short-circuit tab  24 S is erected from the longitudinal-direction near-to-one end position of the bottom surface  70 A of the terminal storing recess  70  and is projected externally of the terminal storing recess  70 ; and, the subordinate short-circuit tab  24 T is erected from the near-to-the-other-end position of the bottom surface  70 A and is stored into the terminal storing recess  70 . And, into the terminal storing recess  70 , there is stored a short-circuit terminal  71  shown in FIG. 13 and, as shown in FIG. 14, the two short-circuit tabs  24 S,  24 T are short-circuited. Specifically, the short-circuit terminal  71  has a structure in which a pair of so called FACEDOWN terminals are connected together. Referring in detail to the structure of the short-circuit terminal  71 , as shown in FIG. 13, a metal plate is bent into a gate shape to thereby form a pair of opposing pieces  72 ,  72 ; two blade pieces  73 ,  73  formed continuously with the two side edge portions of each of the opposing pieces  72 ,  72  are bent on the opposite side to the mating-side opposing piece  72 , and the leading ends of the blade pieces  73 ,  73  are butted against the flat surfaces of the respective opposing pieces  72 ; and, the short-circuit tabs  24 S,  24 T can be held by and between gaps formed between the butted portions. 
     The above structure according to the second embodiment can also provide similar operation and effects to the first embodiment. At the same time, according to the second embodiment, only one ( 24 S) of the short-circuit tabs  24 S,  24 T disposed in the wire connecting portion  22  is connected to the external wire and the other ( 24 T) need not be connected to the external wire and, therefore, the number of tab groups to be provided in the wire connecting portion  22  can be set equal to the number of tab groups employed in the conventional connector block, which makes it possible to use a conventional connector which is provided in the terminal of the external wire. 
     Other Embodiments 
     The present invention is not limited to the above-illustrated embodiments but, for example, other embodiments which will be discussed below also fall under the technical scope of the invention and further, besides the following embodiments, various changes and modifications are also possible without departing from the scope of the subject matter of the invention. 
     (1) In the above-mentioned embodiments, the subordinate bus bar groups  65 A,  65 B are respectively structured such that a plurality of bus bars are collected together by the holders  62 ,  63 . However, there can also be employed a structure in which these bus bars are not collected together by the holders. 
     (2) The holder may be structured in a different manner. That is, the holder may be firstly molded with the bus bars not inserted therein and, after molded, it may be mounted over the bus bars. 
     (3) In the above-mentioned embodiments, there are illustrated a structure in which the branched bus bars according to the invention are used for grounding. However, alternatively, the branched bus bars may be used for power supply.