JP2003157725A - Wire harness - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a wire harness that is superior in heat aging resistance by using a polyolefin insulating wire instead of PVC insulating wire and a polyolefin tape instead of PVC tape for the bundling tape, as a step of environmental problem measures. SOLUTION: This is a wire harness that is constructed of a bundle of wires of a plurality of non-halogen polyolefin insulating wires, and the wire harness is assembled by winding a tape having adhesive that uses polyolefin resin composition such as polyethylene as a base material so that the adhesive may not directly contact the insulating wire.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire harness used for automobiles and the like.

[0002]

2. Description of the Related Art In automobiles, a so-called wire harness is used for internal wiring. A wire harness is also called an assembled electric wire, and it bundles a plurality of electric wires and assembles them in advance in a form necessary for wiring. As shown in Fig. 1, necessary branching, connector attachment to terminals, etc. After being carried out, it is formed by winding a tape around the outer circumference of the wire bundle. A PVC insulated wire is widely used as an electric wire, and a PVC tape with an adhesive is widely used as a tape. In addition, such a form of the wire harness is also used for wiring an aircraft or an electric device such as a video.

[0003]

By the way, with respect to the PVC insulated wire that has been widely used as an insulated wire, it has recently become necessary to consider a substitute as a part of measures against environmental problems. Then, as an alternative to the PVC insulated wire, a so-called non-halogen polyolefin insulated wire in which a large amount of an inorganic filler is added to polyolefin has been studied. However, it has been found that when a PVC tape is wrapped around a non-halogen polyolefin insulated wire, the heat aging performance of the non-halogen polyolefin insulated wire may deteriorate. It was presumed that the cause was that the antioxidant in the polyolefin migrated to the PVC side when heated in a state where the PVC and the polyolefin were in direct contact with each other. Therefore, it was necessary to review the PVC tape used for wire harnesses. We considered using a polyolefin tape as a wire harness tape, but if the adhesive applied to the tape directly touches the insulated wire, the heat aging resistance of the insulated wire may deteriorate. I understand
It was presumed that the cause was probably that the antioxidant in the insulating polyolefin migrated to the adhesive side.

[0004]

SUMMARY OF THE INVENTION The present invention is a wire harness comprising a wire bundle of a plurality of non-halogen polyolefin insulated wires, wherein the tape wound around the outer circumference of the wire bundle is made of a polyolefin resin composition. An object of the present invention is to provide a wire harness characterized in that it is a tape with an adhesive using an object as a base material, the tape being wound so that the adhesive does not directly contact the insulated electric wire. The winding of the tape so that the adhesive does not come into direct contact with the insulated wire can be realized by winding the tape with the adhesive surface facing outward.

[0005]

FIG. 1 shows an example of an embodiment of the present invention, and the contents of the invention will be described based on the drawings. FIG. 1 is an external view of a wire harness, in which 1 is the entire wire harness, 2 is an electric wire for bundling a plurality of wires, 3 is a connector attached to an end of the electric wire, and 4 is a tape for bundling the wires. There is. As the material of the tape, a resin composition containing polyolefin as a main component, such as polyethylene, polypropylene, an ethylene vinyl acetate copolymer, or an ethylene ethyl acrylate copolymer, may be used alone or may be blended.

As the inorganic fillers added to the resin composition, there are calcium silicate, calcium carbonate, silica, graphite and the like, but magnesium hydroxide, aluminum hydroxide and the like which have the effect of improving the flame retardancy of the polyolefin resin. It is also possible to select the above metal hydroxide. When the wire harness is required to have flame retardancy, this selection is extremely useful because it can also impart flame retardancy. Other commonly used anti-aging agents, lubricants, flame retardants,
A rubber or plastic additive such as a cross-linking aid may be added to the resin composition for use.

The tape is formed into a film by ordinary T-die extrusion, inflation, calendering, etc.
Although it can be produced by slitting to a predetermined width, in the present invention, it is preferable that the tape is thin, preferably 0.1 mm or less in thickness and substantially stretched in the length direction.

As the pressure-sensitive adhesive, an EVA-based or rubber-based pressure-sensitive adhesive which is usually used for pressure-sensitive adhesive tapes can be used. Also, if you apply the adhesive only on a part of the width of the tape and wrap it with about half wrap, even if you wrap it with the adhesive side facing outward, you will be able to see the outside of the wire harness after wrapping the tape. It is preferable because the adhesive can be hardly exposed on the surface. Furthermore, in the case of such a tape, by devising the end portion of the tape, even if the adhesive surface is wound inward, the adhesive exists only between the layers of the wound tape, and the adhesive is directly attached. You can wrap the tape so that it does not touch the wires.

[0009]

Example Insulated electric wire 2 in which a copper wire having an outer diameter of 0.8 mm is coated with a halogen-free flame-retardant polyolefin having a thickness of 0.4 mm 2
A wire harness model was produced by winding a tape around the bundle of 0 pieces by half wrap as shown in FIG.

As the tape, a PVC tape with an adhesive and a high density polyethylene tape with an EVA adhesive were used. For PVC tape with adhesive, wrap the adhesive side toward the wire bundle side, and for EVA-based high-density polyethylene tape with adhesive, wrap the adhesive surface toward the wire bundle side. And the one in which the pressure-sensitive adhesive surface was directed outward so that the pressure-sensitive adhesive did not directly contact the electric wire.

With respect to the wire harness model produced as described above, the following heat aging resistance test was conducted. (Heat resistance aging test) The wire harness model is put in a constant temperature bath at 140 ° C and heated for 96 hours. Take out the insulated wire from the heated wire harness model, wind it around its own diameter, and check for cracks.

In the case of a PVC tape with an adhesive or a polyethylene tape with an adhesive, a wire harness model in which the adhesive surface is wound toward the wire bundle side is heated by an insulated wire taken out after heating. The insulated wire that was in direct contact with the adhesive inside had a crack when wound around its own diameter. However, in the case of a wire harness model in which the adhesive tape is oriented outward so that the adhesive does not directly touch the insulated wire, even if the insulated wire taken out after heating is wrapped around the self-diameter However, no insulated wire was cracked.

[0013]

As described above, if a tape with an adhesive, which is based on a resin composition mainly composed of polyolefin, is wrapped around the electric wire so that the adhesive does not directly touch the electric wire, a wire harness is finished. It was possible to obtain a wire harness having excellent heat aging resistance. In addition, if the material for both the insulating material of the electric wire and the tape is polyolefin, it is very preferable in view of environmental problems, and the wire harness of the present invention has extremely high industrial utility value.

[Brief description of drawings]

FIG. 1 is an external view showing an example of a wire harness of the present invention.

FIG. 2 is a sectional view of a portion A in FIG.

[Explanation of symbols]

1 whole wire harness 2 insulated wire 3 connectors 4 Tape with adhesive

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takamitsu Miyakoi             1-7-10 Kikuzumi, Minami-ku, Nagoya-shi, Aichi             Auto Network Technical Laboratory Co., Ltd. (72) Inventor Hiroyuki Hayashi             1-7-10 Kikuzumi, Minami-ku, Nagoya-shi, Aichi             Auto Network Technical Laboratory Co., Ltd. (72) Inventor Masatomo Honkawa             Sumitomo Den 1-14 Nishi-Suehiro-cho, Yokkaichi-shi, Mie Prefecture             Sozo Co., Ltd. F-term (reference) 4J004 AA05 AA09 AB01 CA04 CA07                       CE03 FA05 FA08                 4J040 CA001 DE021 JA09 JB09                       NA19                 5G309 AA11                 5G357 DA10 DB03 DC12 DD20

Claims (2)

[Claims] 1. A wire harness composed of a wire bundle of a plurality of non-halogen polyolefin insulated wires, wherein a tape to be wound around the outer circumference of the wire bundle is provided with an adhesive and is made of a resin composition containing polyolefin as a main component. A wire harness, which is a tape as a base material and is wound so that the adhesive does not directly contact the insulated electric wire. 2. The wire harness according to claim 1, wherein the adhesive of the adhesive-attached tape is applied only to a part of the tape in the width direction.