MOLDED WIRE HARNESS

Abstract: A molded wire harness comprises a trunk line formed by impregnating a bundle of a plurality of wires with a synthetic resin through molding so as to maintain a predetermined shape conforming to the wiring path thereof on the body of an auto­ mobile, a plurality of branch lines extended from the trunk line and entirely or partly impregnated with a synthetic resin through molding so as to maintain predetermined shapes conforming to the wiring paths thereof on the body, respectively, and connec­ tors connected to the free ends of the trunk line and the branch lines for connecting the trunk line and the branch lines to electric equipments, respectively. Positioning projections (17) for posi­ tioning the trunk line on the body and clamps (18) for fastening the trunk line to the body are formed integrally with the trunk line through molding. A flexible or stretchable size adjusting part or parts (19) each formed by enclosing loosely extended wires in a corrugated tube are formed at a part or parts of the trunk line and/­ or the branch lines to facilitate mounting the molded wire harness on the body.

Description: BACKGROUND OF THE INVENTION The present invention relates to a wire harness for use in the electric circuit of an automobile and, more specifically, to a molded wire harness formed so as to be arranged on the body of an automobile. Generally, a wire harness for use in the electric circuit of an automobile comprises a trunk portion formed by binding a plurality of wires with tapes, and branch portions of different lengths extending from the trunk portion. The trunk portion is arranged along a car body and is secured thereto with clips, while connectors connected to the respective free ends of the branch portions are connected to the electric equipment. Such a wire harness will be described more concretely with reference to Figure 7. A trunk portion 1 is formed by binding a plurality of wires with tapes. A plurality of branch portions 2 of different lengths are branched from the trunk portions 1. Connectors 3 connected to the respective free ends of the branch portions 2 are connected to electric equipment including motors and switches. An electric junction box 4 serving as a junction box and a fuse box is provided to protect the wire harness (preventing a fire attributable to a short-circuit) and to concentrate the electronic units. A grommet 5 is provided in a hole formed in the car body to protect the wire harness extending through the hole. Clips 6 for fixing the wire harness to the body are fixed to the wire harness with tapes. The trunk portion 1 has a slack portion 7 therein to facilitate the positional adjustment of the wire harness in arranging the same on the body. In Figure 7, indicated at 8 is the lean horse of an instrument panel 9 on which the wire harness is arranged. In fixing the wire harness W to the lean horse 8 and the panel 9, the wire harness W is passed through hole formed in the body, not shown, and the grommet 5 is fitted in the through hole, then the clips 6 are fixed sequentially to the body to fasten the wire harness W to the body, and then the connectors 3 are connected to the corresponding electric equipment, respectively. In arranging the wire harness W on the body in such a manner, the slack portion 7 of the wire harness W is necessary for the positional adjustment of the wire harness W on the lean horse 8 and the panel 9. As apparent from the foregoing description, the conventional wire harness has a plurality of branch portions extending in indefinite directions from the trunk portion and has an excessively high degree of freedom, and hence it is very difficult to automate the wire harness arranging process. On the other hand, the entanglement of the branch portions with each other in storing or transporting the wire harness makes the automation of the wire harness arranging process further difficult. Furthermore, the slack portion of the trunk portion for the positional adjustment of the wire harness in arranging the same on the body generates noises while the automobile is running. It is known from DE-A-3337596 to enclose the wires of a short trunk portion of a wiring harness in synthetic resin material, but no provision is disclosed for adjustment of the trunk portion to enable it to fit properly in the car body. Accordingly, it is an object of the present invention to provide a molded wire harness in which the foregoing drawbacks of the conventional wire harness are eliminated, which is capable of being arranged on the body of an automobile through an automated process, and having no slack portion of the trunk line which is liable to cause noises. According to the invention there is provided a molded wire harness comprising: a trunk portion comprising a plurality of wires, entirely or partly impregnated with a synthetic resin or the like through molding so as to maintain a predetermined shape conforming to the wiring path thereof on the body of an automobile; a plurality of branch portions extending from the trunk portion, and entirely or partly impregnated with a synthetic resin or the like through molding so as to maintain predetermined shapes conforming to the wiring paths thereof on the body, respectively; and connectors connected to the free ends of the trunk portion and the branch portions for connecting the trunk portion and the branch portions to electric equipments, respectively, characterised by at least one size adjusting portion in the trunk portion and/or the branch portions said size adjusting portion being flexible or stretchable. Since the wire harness according to the present invention has a trunk portion and branch portions which are formed by sheathing wires in a synthetic resin by molding in predetermined shapes, respectively, the wire harness is capable of maintaining the predetermined shape. Accordingly, it is possible to automate most part of the manual assembling work for mounting the wire harness on the body of an automobile. Furthermore, since the molded wire harness according to the present invention has at least one flexible or stretchable size adjusting portion, which may employ a corrugated tube or tubes instead of a slack part or parts provided in the conventional wire harness, the molded wire harness can be arranged on the body of an automobile substantially without any slack by properly bending, stretching or contracting the size adjusting part when necessary, so that the molded wire harness does not generate any noise. The above and other objects, features and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of assistance in explaining a process for forming a molded wire harness according to the present invention; Figure 2 is a perspective view of molded wire harnesses according to the present invention as arranged on the body of an automobile; Figure 3 is a partly cutaway fragmentary perspective view of a molded wire harness according to the present invention; Figures 4a, 4b and 4c are sectional views of assistance in explaining the function of a corrugated tube provided in a molded wire harness according to the present invention; Figures 5a and 5b are a longitudinal sectional view and a cross-sectional view, respectively, of a part indicated at A of the molded wire harness shown in Figure 3; Figure 6 is a perspective view of assistance in explaining another process for forming a molded wire harness according to the present invention; and Figure 7 is perspective view of assistance in explaining the constitution of a conventional wire harness shown in combination with the lean horse and instrument panel of an automobile. BRIEF DESCRIPTION OF THE DRAWINGS Referring to Figure 1, a wire harness W has a substantially L-shaped trunk line 10 and branch lines 11. The wire harness W is the same as the conventional wire harness in construction except that a plurality of the component wires thereof are bound loosely at several parts with band clips or tapes 12. Connectors 13 are connected to the respective free ends of the branch lines 11, respectively. A mold consists of a top half mold 14 and a bottom half mold 15 each having two molding grooves 16. Recesses, not shown, for molding positioning projections 17 and clamps 18, which will be described afterward, are formed in the molding grooves 16. A corrugated tube 19 is fitted on the corner of the wire harness W before placing the wire harness W in the mold for molding. Figure 2 illustrates a molded wire harness W' formed by placing the wire harness W in the mold and injecting a synthetic resin into the mold. The corrugated tube 19 is a flexible or stretchable tube made of elastic rubber, a synthetic rubber or a synthetic resin, such as soft vinyl chloride or polyethylene. The most portion of the trunk line 10 and a portion of each branch line 11 of the molded wire harness W' are sheathed in the synthetic resin so that the molded wire harness W' maintains a fixed shape and each branch line 11 is directed in a predetermined direction as illustrated in Figure 2. The positioning projections 17 for positioning the molded wire harness W' on the body of an automobile and the clamps 18 for fastening the molded wire harness W' to the body are formed integrally with the trunk line 10. As illustrated in Figure 3, a plurality of wires 20 are extended loosely in the corrugated tube 19 so that the corrugated tube 19 in a state as shown in Figure 4a can be contracted in a state as shown in Figure 4b or stretched in a state as shown in Figure 4c. Naturally, the corrugated tube 19 is bendable. As illustrated in Figures 5a and 5b, the trunk line 10 is fully impregnated with a synthetic resin 21 in a solid state, and hence gaps between the wires 20 are filled with the synthetic resin 21. When necessary, the connectors 13 can be waterproofed by injecting the synthetic resin 21 into the connectors 13. As mentioned above, since the molded wire harness W' maintains a fixed shape, the molded wire harness W' can be transported and attached to the body B as illustrated in Figure 2 by a conveying apparatus and an assembling robot, not shown, by automatically putting the positioning projections into corresponding positioning recesses and automatically fastening the clamps 18 to the body B. After the molded wire harness W' has thus been attached to the body B, the connectors 13 are connected manually to the electric equipments, respectively. Since the molded wire harness W' has a size adjusting part provided with the corrugated tube 19 and is flexible and stretchable, the automatic assembling of the molded wire harness W' and the body B is carried out comparatively easily. Furthermore, substantially, the molded wire harness does not have any slack therein, and hence the molded wire harness W' mounted on the body B does not generate any noise while the automobile is running. Figure 6 illustrates a molded wire harness W' formed by another process. Positioning projections 17' and clamps 18', which are formed through separate processes, are attached with wires or suitable means to a bundle of wires 20, and then an organic solvent is sprayed on the wires 20, the positioning projections 17' and the clamps 18' with a spray gun 22 to dissolve the surfaces of the same so that the wires 20, the positioning projections 17' and the clamps 18' are joined together adhesively. The organic solvent is tetrahydrofuran, methanol, ethanol, benzene or trichloroethylene. As apparent from what has been described hereinbefore, since the molded wire harness according to the present invention maintains a predetermined shape and has a flexible or stretchable size adjusting part or parts, part of the work for attaching the molded wire harness to the body of an automobile can be automated, and there is no possibility that the molded wire harness generates noises while the automobile is running. Furthermore, since the molded wire harness maintains the predetermined shape, the branch lines will not entangle with each other in storing or transporting the molded wire harness, which facilitates handling the molded wire harness. Still further, the molded wire harness including the connectors incorporated thereto can be waterproofed by perfectly impregnating the bundle of the component wires and the connectors in the molding process. Although the invention has been described in its preferred form with a certain degree of particularity, it is to be understood that many variations and changes are possible in the invention without departing from the scope as defined in the claims.

Claims: A molded wire harness comprising: a trunk portion (10) comprising a plurality of wires (20), entirely or partly impregnated with a synthetic resin or the like (21) through molding so as to maintain a predetermined shape conforming to the wiring path thereof on the body of an automobile; a plurality of branch portions (11) extending from the trunk portion, and entirely or partly impregnated with a synthetic resin or the like through molding so as to maintain predetermined shapes conforming to the wiring paths thereof on the body, respectively; and connectors (13) connected to the free ends of the trunk portion (10) and the branch portions (11) for connecting the trunk portion and the branch portions to electric equipments, respectively, characterised by at least one size adjusting portion (19) in the trunk portion and/or the branch portions said size adjusting portion being flexible or stretchable. A molded wire harness as claimed in Claim 1, wherein positioning projections for positioning the molded wire harness on the body, and clamps for fastening the molded wire harness to the body are formed integrally with the trunk line. A molded wire harness as recited in Claim 1, wherein said at least one size adjusting part is formed of loosely extended wires enclosed in a corrugated tube. A molded wire harness as recited in Claim 1, wherein said connectors are waterproofed by being impregnated with a synthetic resin or the like.

Inventors: KANEKO, KAZUHIKO, MATSUMOTO, ETSUJI, WATANABE, MITSUGU
Applicants: YAZAKI CORPORATION
Application year: 1987
Main classification: B60R16
IPC codes: B60R16, H01B7