Junction connector for wire harness

Abstract: A junction connector (10) can be connected with wire harnesses from different directions. The junction connector (10) comprises a shell containing junction circuits including at least two connector-fitting portions (18, 19, 20, 21) oriented along different directions. The junction circuits (10) comprise a plurality of bus bar layers (14, 16), each of the bus bar layers (14, 16) including a bus bar group (13, 15). Each of the bus bars (13, 15) is formed into the shape of a strip having two end tabs (13a, 13b, 15a, 15b) and aligned at a given interval from each other along the same direction. The bus bar layers (14, 16) are superposed so that the bus bars groups (13, 15) are arranged in a skewed direction to each other, thereby forming cross points (P1 to P6) between the bus bar groups (13, 15), and the bus bars (13, 15) are bonded through the cross points (P1 to P6), thereby forming junction circuits. Connectors bound to wire harnesses are then fitted into the connector-fitting portions (18, 19, 20, 21), so that the electrical cables W in the wire harnesses are splice-connected through the bus bars (13, 15).

Description: The present invention relates to a junction connector incorporated into wire harnesses used in automobiles. More particularly, the invention concerns a junction connector, in which electrical cables can be connected from different directions. The wiring of harnesses in an automobile also involves the installation of electrical connector housings, such as junction boxes, comprising internal circuits. When a splicing operation cannot be carried out in the internal circuits, the junction connector is connected to electrical cables, prior to the splicing operation. In such a case, junction connectors having a structure shown in Fig. 1 are commonly used. The above junction connector 1 includes a case 2 with a fitting recess 1a. The fitting recess contains a plurality of junction bus bars 3 provided with respective tabs 3a. Electrical cables w are branched out from a wire harness W/H. The edges of such electrical cables w are provided with terminals. These terminals are inserted into a connector 4 and locked therein. The connector 4 is then engaged with the fitting recess 1a in the junction connector 1 and locked, whereby the electrical cables w are joined. The connector 4 and the junction connector 1 are bound to the wire harness W/H by taping. In the above junction connector 1, the tabs 3a of the junction bus bars 3 are oriented in the same direction. Moreover, the junction connector 1 has only one fitting recess 1a through which the counterpart connector 4 is fitted. Because of this single orientation of the fitting recess 1a, the junction connector 1 can receive the counterpart connector 4 only from one direction. As shown in Fig.2, the wire harnesses W/H, e.g. W/H-1, -2, -3 and -4 may be wired in a T or cross configuration. However, the junction connector 1 can receive only one counterpart connector 4 from one direction. Therefore, when some electrical cables of these wire harnesses W/H need to be spliced, the electrical cables to be spliced are forcibly inserted into a wire harness W/H, as shown in Fig.1, so that the wire harnesses W/H are connected to the junction connector 1. In the above structure, the wire harnesses W/H, and the constituent electrical cables w connecting to the junction connector 1, are not configured in the most suitable way. Furthermore, setting-up positions of the junction connector get restricted, so that the junction connector cannot always be placed appropriately in the limited space of an automobile. Document US-5 507 668 A discloses a junction connector comprising a shell containing junction circuits with at least two connector-fitting portions arranged at the four sides of the shell. In view of the above, an object of the present invention is to provide a junction connector which can be connected from a plurality of directions, enables optimum arrangements, distributions or divisions of wire harnesses, and which can be arranged in an appropriate position inside the effective space of an automobile. To this end, there is provided a junction connector comprising a shell which contains junction circuits and at least two connector-fitting portions oriented in different directions. The junction circuits comprise at least a first bus bar layer and a second bus bar layer, which include first and second bus bars, respectively. Further, the first and second bus bars have two respective end tabs and are aligned at a given interval from each other in the same direction, respectively. The second bus bar layer is then superposed on the first bus bar layer such that the direction of the second bus bars are skewed relative to that of the first bus bars, thereby forming cross points between the first bus bars and the second bus bars. The first and second bus bars are then bonded through the cross points, thereby forming junction circuits. In this junction connector structure, the orientation of connector-fitting portions can be very easily arranged in different directions. Accordingly, when electrical cables are splice-connected through the junction connector, there is no need to group them in one wire harness. There is no need either to group several wire harnesses into one direction by force. Instead, they can be brought into the junction connector from a plurality of directions. The circuits can thus be designed as a function of the wired state of wire harnesses and/or the set-up space for the junction connector. As a result, wire harnesses can be arranged, divided or distributed in an optimum way. In the above junction connector, the shell defines peripheral rims. The second bus bar layer may then be superposed on the first bus bar layer such that the second bus bars are arranged perpendicular to the first bus bars. Further, the shell may include at least three connector-fitting portions which are provided on the peripheral rims and separated at an angle of 90 degrees from each other around the center axis of the shell. The connector-fitting portions may then contain the end tabs of the first and second bus bars. As a variant, at least one of the at least first and second bus bar layers may include at least one bus bar comprising upwardly- and/or downwardly-bent end tabs, and the shell may comprise corresponding upward- and/or downward connector-fitting portions. The connector-fitting portions may be arranged at an angle of 90 degrees from each other in the horizontal direction, measured around the center axis of the shell. Further, an upward and a downward connector-fitting portion may be added, bringing the total number of connector-fitting portions to six. Where necessary, the number of bus bar layers may be more than two. A bus bar layer may be added in a crossed direction over the adjacent bus bar layer, but it can also be laid out at a desired skewed angle, e.g. at 45 degrees. In this manner, multi-directional connector-fitting portions may be produced. Preferably, an insulating sheet is interposed between the at least a first bus bar layer and the second bus bar layer. The insulating sheet is provided with openings at the positions corresponding to the cross points. The first bus bars included in the first bus bar layer are then bent into the openings, so that they are brought into contact with the second bus bars included in the second bus bar layer, and joined therewith. As another variant, the junction connector further comprises a third bus bar layer with corresponding third bus bars and end tabs likewise arranged. The third bus bar layer is then superposed on the second bus bar layer such that the direction of the third bus bars is skewed relative to that of the second bus bars, thereby forming cross points between the second bus bars and the third bus bars. The second and third bus bars are then bonded through the cross points, thereby forming junction circuits. Preferably, a second insulating sheet is interposed between the second bus bar layer and the third bus bar layer. The second insulating sheets is then provided with openings at positions corresponding to the cross points. The second bus bars and the third bus bars are bent into the openings, so that the second bus bars are brought into contact with the third bus bars through the openings, and bonded therewith. The above and the other objects, features and advantages of the present invention will be made apparent from the following description of the preferred embodiments, given as non-limiting examples, with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of a wire harness, a connector and a junction connector known in the prior art; Fig.2 is a view schematically showing how wire harnesses are joined to a connector according to the prior art; Fig.3A is a top plan view of the junction connector according to a first embodiment of the invention; Fig.3B is a schematic view showing the fitting directions between wire harness ends and the junction connector of Fig.3A; Fig.4A is a side view of the junction connector of Fig.3A; Fig.4B is a cross-sectional view along line A-A of the junction connector of Fig.3A; Fig.5A is a top plan view showing the arrangement between an X-directional bus bar layer and a Y-directional bus bar layer; Fig.5B is a top plan view when an insulating sheet is interposed between the X-directional bus bar layer and the Y-directional bus bar layer of Fig.5A; Fig.6A is a top plan view of an insulating sheet; Fig.6B is a cross-sectional view along line B-B of the insulating sheet of Fig.6A; Fig.6C is a cross-sectional view along line C-C of the insulating sheet of Fig.6A; Fig.7 is a cross-sectional view showing how two bus bar layers are connected through the insulating sheet; Fig.8 is a top plan view showing how bus bar layers are superposed according to a variant of the first embodiment of the invention; Fig.9 is a schematic view showing a location where the junction connector of Fig. 8 is applied; Fig.10A is a cross-sectional view of the junction connector according to a second embodiment of the invention; Fig.10B is a cross-sectional view of a resistance-welded portion between the first and second bus bars of the junction connector of Fig.10A; Fig. 11A is a top plan view of the junction connector according to a third embodiment of the invention; Fig.11B is a cross-section of the elevational side view of the junction connector of Fig.11A; Fig.12 is a top plan view of a variant according to the third embodiment of the invention; and Fig.13 is a cross-sectional view of a rivetted portion between the first and second bus bars of the junction connector according to a fourth embodiment of the invention. Figs.3 to 7 show a junction connector 10 according to a first embodiment of the invention. The junction connector 10 comprises a bottom shell 11 and a top shell 12, and the whole structure has a substantially thin square shape. Inside the junction connector 10, first bus bars 13 in the form of a strip are arranged in parallel along the same direction (for example, the X direction), at a given spacing from each other, thereby forming a first bus bar layer 14. Second bus bars 15 having the same shape are likewise arranged, but in a direction (Y direction) perpendicular to the X direction, so as to form a second bus bar layer 16. These two layers 14 and 16 are superposed with an insulating sheet 17 interposed therebetween. The two faces of the insulating sheet 17 are provided with a set of grooves 17a respectively in a cross arrangement. The first bus bars 13 in the first bus bar layer 14 and the second bus bars 15 in the second bus bar layer 16 are then fitted into the crossing grooves 17a on the both sides of the insulating sheet 17. When selected first bus bars 13 and second bus bars 15 are to be connected together, the connections are made through cross positions P1 to P6. To this end, the interposing insulating sheet 17 comprises openings 17b. The bus bars 13 are then bent in a U shape, so as to be brought into contact with the bus bars 15. Both bus bars 13 and 15 are bonded in this state by resistance welding. When there is an unused portion in the circuitry, for example portion C in Fig.5A, the corresponding bus bar is removed from that portion. The both ends of the bus bars 13 and 15 are provided with a respective end tab 13a, 13b, 15a or 15b. When the bottom shell 11 and the top shell 12 are joined, they define four sides. There are then provided connector-fitting portions 18, 19, 20 and 21 projecting from these respective sides. The end tabs 13a, 13b, 15a and 15b protrude into the corresponding connector-fitting portions 18, 19, 20 and 21. This configuration enables the junction connector 10 to be connected with counter-part connectors from different directions. In this configuration, the junction connector 10 is connected with connectors 24 to 27 at 90° to each other, measured around the center axis of the shell. The splice circuits can thus be prepared as desired. Accordingly, to form splice circuits, it is no longer necessary to incorporate electrical cables into one wire harness. Instead, the electrical cables to be spliced can be divided into wire harnesses W/H-1, -2, -3 and -4 in a suitable way. Fig.8 shows a variant of the first embodiment. The first bus bar layer 14 and the second bus bar layer 16 are formed in a junction circuit, as in the first embodiment. However, only one end of the second bus bars 15, which form the second bus bar layer 16, includes an end tab 15a connecting to a counterpart connector, and the other end is left open. By contrast, the first bus bars 13, which form the first bus bar layer 14, comprise the two ends respectively provided with an end tab 13a and 13b, as in the first embodiment. In the variant, the connector-fitting portions of the junction connector 10 have three directions, and are disposed at a 90° angle to neighboring connector, around the center axis of the shell. The junction connector 10 including three connector-fitting portions may be installed in a rear lamp circuit as shown in Fig.9. The junction connector 10 can thus be mounted between floor harnesses W/H -1, -2 and -3, which extend in three directions. Desired splice circuits may thus be formed in an appropriate way. Figs.10A and 10B show a second embodiment in which a third bus bar layer 30 is aligned in the X direction and added to the first and second bus bar layers 14 and 16. The bus bar layers 14 and 30 arranged in the X direction thus flank the bus bar layer 16 arranged in the Y direction. Insulating sheets 17 and 31 are interposed between the bus bar layers, as in the first embodiment. In order to connect the three bus bar layers 14, 16 and 30, the insulating sheet interposed between the two adjacent bus bar layers is provided with openings, as in the first embodiment. One of the bus bar layers is bent into a U shape, and thus brought into contact with the other bus bar layer. Both layers are then bonded by resistance welding. When splice-connecting many circuits, it suffices to increase the number of bus bar layers arranged either in the X or Y direction. Further, when an added bus bar layer is skewed by 45 degrees, instead of 90 degrees, relative to an adjacent layer along a bus bar direction, more than four connector-fitting portions can be formed in the horizontal direction. Fig. 11shows a third embodiment of the present invention, in which one end of the first bus bars 13, which constitute the X-directional first bus bar layer 14, is bent upwards (in the top plan view of Fig. 11), to form upward end tabs 13a'. The other end of the first bus bars 13 extends horizontally, so as to form horizontal end tabs 13b. Furthermore, one end of the second bus bars 15, which constitute the Y-directional second bus bar layer 16, is bent downwards to form downward end tabs 15b'. The other end of the bus bars 15 extends horizontally, so as to form horizontal end tabs 15a. The bottom shell and the top shell include connector-fitting portions which are oriented along the directions of end tabs. For example, the bottom shell may comprise a downward connector-fitting portion from which the end tabs 15b project, whilst the top shell may comprise an upward connector-fitting portion corresponding to the end tabs 13a. Further, the other connector-fitting portions may be provided on the outer rims of the bottom and top shells at an angle of 90 degrees around the center axis of the shell, from which the end tabs 13b and 15a project. In this manner, there are provided two horizontally-directed connector-fitting portions, and two connector-fitting portions directed upwards and downwards, respectively separated at an angle of 90 degrees around the center axis of the shell. Counterpart connectors can thus be connected from four different directions. Accordingly, the wire harnesses can be divided in the functionally most suitable way. Fig.12 shows a variant of the third embodiment of the invention, in which one end of some of the first bus bars 13, which constitute the X-directional first bus bar layer 14, is bent upwards, so as to form upward end tabs 13a', whilst one end of the other first bus bars 13 forms horizontal end tabs 13a. Likewise, some of the second bus bars 15, which constitute the Y-directional second bus bar layer 16, may have one end provided with downward end tabs 15b', whilst one end of the other second bus bars 15 may be provided with horizontal end tabs 15b. Together with four horizontal connector-fitting portions formed at an interval of 90 degrees, there is further provided an upward and a downward connector-fitting portion, amounting to six connector-fitting portions with different directions. Fig.13 shows a fourth embodiment of the present invention, in which the X-directional first bus bars 13 and the Y-directional second bus bars 15 are joined by rivets 40, instead of resistance welding. In the junction connector according to the invention, connector-fitting portions, through which are fitted the counterpart connectors bound to wire harnesses, can be designed to be oriented in different directions as desired. The wire harnesses can thus be divided suitably, as a function of the wiring conditions, and their branching positions can be chosen depending on the effective space in an automobile. Furthermore, the internal circuits of the junction connector are made by combining bus bar strips. These bus bar strips can be produced very easily at a low cost.

Claims: A junction connector (10) comprising a shell containing junction circuits, said shell further contains at least two connector-fitting portions (18, 19,20,21) oriented along different directions, said shell has four sides from which project said connector-fitting portions (18, 19, 20 and 21), so that said end tabs (13a, 13b, 15a, 15b) protrude into the corresponding connector-fitting portions (18, 19, 20 and 21), characterised in that said junction circuits comprise at least a first bus bar layer (14) and a second bus bar layer (16), said first and second bus bar layers (14, 16) include first and second bus bars (13, 15), respectively, said first and second bus bars (13, 15) have two respective end tabs (13a, 13b, 15a, 15b) and are aligned at a given interval from each other in the same direction, respectively, said second bus bar layer (16) is superposed on said first bus bar layer (14) such that the direction of said second bus bars (15) is skewed relative to that of said first bus bars (13), thereby forming cross points (P1 to P6) between said first bus bars (13) and said second bus bars (15), and said first and second bus bars (13, 15) are bonded through said cross points (P1 to P6), thereby forming junction circuits. The junction connector according to claim 1, wherein said shell defines peripheral rims, said second bus bar layer (16) is superposed on said first bus bar layer (14) such that said second bus bars (15) are arranged perpendicular to said first bus bars (13), said shell includes at least three connector-fitting portions (18, 19, 20, 21) which are provided on said peripheral rims and separated at an angle of 90 degrees from each other around the center axis of said shell, and said connector-fitting portions (18, 19, 20, 21) contain said end tabs (13a, 13b, 15a, 15b) of said first and second bus bars (13, 15). The junction connector (10) according to claim 1 or 2, wherein at least one of said at least first and second bus bar layers (14, 16) includes at least one bus bar comprising upwardly- and/or downwardly-bent end tabs (13a', 15b'), and said shell comprises corresponding upward- and/or downward connector-fitting portions. The junction connector (10) according to any one of claims 1 to 3, wherein an insulating sheet ((17) is interposed between said at least a first bus bar layer (14) and a second bus bar layer (16), said insulating sheet (17) being provided with openings (17b) at positions corresponding to said cross points (P1 to P6), said first bus bars (13) included in said first bus bar layer (14) are bent into said openings (17b), so that they are brought into contact with said second bus bars (15) included in said second bus bar layer (16), and joined therewith. The junction connector (10) according to any one of claims 1 to 4, further comprising, in addition to said at least first and second bus bar layers, a third bus bar layer (30) with corresponding third bus bars and end tabs likewise arranged, wherein said third bus bar layer (30) is superposed on said second bus bar layer (16) such that the direction of said third bus bars is skewed relative to that of said second bus bars (15), thereby forming cross points between said second bus bars (15) and said third bus bars, said second and third bus bars being bonded through said cross points, thereby forming junction circuits. The junction connector (10) according to claim 5, wherein a second insulating sheet (31) is interposed between said second bus bar layer (16) and said third bus bar layer (30), said second insulating sheet (31) being provided with openings at positions corresponding to said cross points, and said second bus bars (15) and said third bus bars are bent into said openings, so that said second bus bars (15) are brought into contact with said third bus bars through said openings, and bonded therewith.

Inventors: OKA YOSHITO, OKA, YOSHITO, Oka, Yoshito, c/o Sumitomo Wiring Systems Ltd
Applicants: SUMITOMO WIRING SYSTEMS, SUMITOMO WIRING SYSTEMS, LTD.
Application year: 2000
Main classification: H01R9
IPC codes: H01R9, H05K1, H05K3, H01R31, H02G3