JPH0935537A - Wire harness having bending part and forming method for this wire harness - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a bending part regardless of a kind of electric wire of constituting wire harness, by using a heat shrinkable sheet. SOLUTION: A heat shrinkable sheet 12 is wound to the periphery of a bent electric wire group 13, also to fix both ends in a lengthwise direction of this heat shrinkable sheet 12 by winding a tape 15. A bending condition of the electric wire group 13 is held by the heat shrinkable sheet 12 contracted by heating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire harness having a bent portion and a method for forming the wire harness, and more particularly to a bent state maintained by a heat-shrinkable sheet wound around a wire group.

[0002]

2. Description of the Related Art A wire harness is bent and arranged in accordance with the shape of the wiring to a vehicle. Although various methods are adopted as a method for bending the wire harness,
Primarily, by inserting the wire harness into the protector molded with resin in accordance with the required bending shape,
In many cases, the wire harness is bent and held in a desired bent state. However, in the method using the protector, there is a problem that it is necessary to provide a dedicated protector corresponding to the bent shape, the number of parts is increased, management is required, and cost is increased.

On the other hand, as shown in FIG. 9, a method of providing the bent portion 3 on the wire harness 1 without using a protector is disclosed in JP-A-1-307109. In this conventional example, the electric wire 2 which is a single core wire constituting the wire harness 1 is bent at a required position, and the bent portion 3 is flattened so as to crush the core wire of the electric wire 2 to maintain the bent shape. .

[0004]

The method of flattening the electric wire 2 and maintaining the bent state can be applied only to a wire harness consisting of a single core wire, and to a wire harness consisting of a twisted wire which cannot be flattened. Unable to adapt.
Electric wires consisting of single-core wires are hard and difficult to bend, so they are used for the internal circuits of electric junction boxes, etc., but are rarely used as electric wires that compose wire harnesses for external circuits. ing. Therefore, the method of the conventional example of FIG. 9 cannot be adopted as a method of forming the bent portion of the wire harness made of a stranded wire.

The present invention has been made in view of the above problems, and it is an object of the present invention to form a bent portion by using a heat-shrinkable sheet regardless of the type of electric wires that form a wire harness.

[0006]

In order to achieve the above object, in the present invention, in claim 1, a heat shrinkable sheet is wrapped around the outer circumference of a bent wire group, and the length of the heat shrinkable sheet is Provided is a wire harness in which both ends in the direction are fixed by tape winding, and a bent state of an electric wire group is held by the heat-shrinkable sheet contracted by heating.

According to the wire harness having the bent portion according to the first aspect of the present invention, the heat shrinkable sheet is wound around the outer peripheral surface of the wire group forming the wire harness so as to cover the bent portion. The electric wire group is held in a bent state by heating and contracting a portion of the heat-shrinkable sheet that is located inside the bent portion of the heat-shrinkable sheet. In this way, since the bent state of the wire harness is held by the heat-shrinkable sheet wound around the electric wire group, the wire harness can be bent and held without using a protector.

In the present invention, the heat-shrinkable sheet is provided with slits or perforations in a direction orthogonal to the lengthwise direction at predetermined intervals in the lengthwise direction, and the slits or perforations are provided. There is provided a wire harness having a bent portion in which a branch electric wire can be pulled out from a portion cut along the line.

According to the above-mentioned structure, when the electric wire group is branched at the bent portion or in the vicinity of the bent portion, the branch electric wire is passed through the slit or the portion cut along the perforation, and the heat shrinkable sheet is attached. Wrap around. Therefore, the heat-shrinkable sheet can be used also when the bent portion is provided in the portion where the wire group is branched or in the vicinity thereof. Further, the slits or perforations are provided along the direction orthogonal to the length direction with a required interval in the length direction of the heat-shrinkable sheet, so that the electric wire group is provided at a plurality of bent portions and the vicinity of the bent portions. It is also possible to deal with a case where there is a branch and a change in the position of the bent portion with respect to the branch point.

Further, according to the present invention, in claim 3, a wire group is laid along a wire laying jig, a heat shrinkable sheet is wound around an outer peripheral surface of a required portion of the laid wire group, and the wire is wound. Fix both ends of the heat shrinkable sheet in the length direction with tape winding,
Then, the portion wound with the heat-shrinkable sheet is bent at a required angle with the center in the longitudinal direction as a fulcrum, and finally, from the inside of the bent portion, the shrinkage temperature of the heat-shrinkable sheet or more and the heat-resistant temperature of the wire or less The present invention provides a method for forming a wire harness having a bent portion in which a heat-shrinkable sheet is heated at a temperature of, and the shrunk heat-shrinkable sheet holds a wire group in a bent state.

The heating of the wound heat-shrinkable sheet is performed in a state where the electric wire group is held in the required bent shape by a jig erected on the wiring diagram board so as to have the required bent shape. It is preferable to carry out.

According to the method for forming a wire harness having the above-mentioned bent portion, the wire group laid along the wire laying jig is
After winding the heat shrinkable sheet and fixing it with tape, bend the wire group to the required angle and heat the heat shrinkable sheet from the inside of the bent portion to partially shrink it to form the bent portion of the wire harness. be able to.

[0013]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below with reference to the embodiments of the invention shown in the drawings. 1 and 2
In the wire harness 11 having the bent portion shown in, the heat shrinkable sheet 12 is wound around the outer peripheral surface of the wire group 13 in order to provide the bent portion 14 in the wire harness 11. The heat-shrinkable sheet 12 is wound so as to cover the bent portion 14, and the tape 15 is applied to both ends of the heat-shrinkable sheet 12 in the length direction X.
Is wound around and fixed to the wire group 13. The heat-shrinkable sheet 12 fixed in this way is provided with the bent portion 1 of the wire group 13.
The portion of the wire group 4 located on the inner side 14a contracts by heating, and the tension generated by the contraction holds the bent state of the wire group 13. Therefore, a protector for forming the bent portion 14 is not required, and the wire harness 1
The bent portion 14 can be formed regardless of whether the electric wire 18 forming the wire 1 is a single-core wire or a twisted wire.

The heat-shrinkable sheet 12 is made of polyethylene in this embodiment, and has a rectangular wave-shaped cross section as shown in FIGS. 3 (A) and 3 (B). Heat shrink sheet 1
In the heated part of FIG. 2, from the state of FIG. 3 (A) to FIG. 3 (B).
In this state, the grooves 12a on both sides are crushed and contracted in the length direction X. Therefore, the heat shrinkable sheet 12 is
The heat shrinkable sheet 12 is wound around the wire group 13 so that the length direction X of the heat shrinkable sheet 12 and the length direction of the wire group 13 coincide with each other.

Also, an electric wire 18 having less than 10 electric wire groups 13
2A, the heat shrinkable sheet 12 having a thickness of about 0.1 mm is wound 1.5 times, and the wire group 13 is composed of 10 or more wires 18. In the case of being constructed, as shown in FIG. 2B, the heat shrinkable sheet 12 having a thickness of about 0.2 mm is wound twice.

Next, the process of forming the bent portion 14 will be described with reference to FIG. First, as shown in FIG. 4 (A), the electric wire 18 is inserted into the wiring jig 17 which is erected linearly on the wiring diagram board 16 to perform the wiring work, and the wiring work is performed. The heat-shrinkable sheet 12 is wound around a required portion of the formed linear electric wire group 13, and then, as shown in FIG. 4 (B),
Both ends of the wound heat-shrinkable sheet 12 are fixed with tapes 15.

Next, as shown in FIG. 4 (C), the portion around which the heat-shrinkable sheet 12 is wound is taken out from the wiring jig 17, and the length of the heat-shrinkable sheet 12 is set as shown in FIG. 4 (D). It is bent at a required angle with the center P of the direction as a fulcrum, and the inside 14a of the bent portion 14 is heated by, for example, a (dryer) 2
Heat at 1. By heating, the portion of the heat-shrinkable sheet 12 located inside the bent portion 14a shrinks, and the wire group 13 is held in a bent state. The heating temperature is set such that the temperature of the heat shrinkable sheet 12 is equal to or higher than the shrinkage temperature and equal to or lower than the heat resistant temperature of the electric wire 18, for example, 80 degrees Celsius.

FIG. 5 shows another method of forming a bent portion, in which a heat-shrinkable sheet 12 is wound around a wire group, both ends in the length direction thereof are fixed with tapes 15, and then the wire drawing board 16 'is erected. Pass through the jig 20. These jigs are erected at positions that are the bending points of the wire harness in accordance with the bent shape of the wire harness, and by passing through these jigs, the portion around which the heat shrinkable sheet 12 is wound is bent. In an embodiment,
It is bent continuously at two points, P1 and P2. In this state, the bent portion 14A at the point P1 and the bent portion 1 at the point P2
Hot air is blown from the inner peripheral side of 4B by the heating means 21 to heat the heat shrinkable sheet 12. As a result, as in FIG.
Can hold a bent state.

6 and 7A and 7B show a first modification of the heat shrinkable sheet. Heat shrinkable sheet 22 of this modification
A slit 22a for pulling out the branch electric wire is provided at a predetermined interval in the length direction X along the direction Y orthogonal to the length direction X, that is, the winding direction of the heat shrinkable sheet 12. As shown in FIGS. 7A and 7B, the heat shrinkable sheet 22 is wound around the wire group 13 with the branch wire 13a passing through the slit 22a. When the heat-shrinkable sheet 22 is wound, both ends of the heat-shrinkable sheet 22 are fixed with the tape 15.
Next, the wire group 13 is bent to heat the heat shrinkable sheet 22.

The heat-shrinkable sheet 32 of the second modification shown in FIG. 8 is provided with perforations 32a instead of slits. When the heat shrinkable sheet 32 is wound around the branch point of the wire group 13, the required perforation 32 is necessary.
The heat shrinkable sheet 32 is cut along a, and the branch electric wire is pulled out from the slit-shaped cut portion.

[0021]

As is apparent from the above description, in the wire harness having the bent portion according to claim 1 of the present invention, the heat-shrinkable sheet wound around the wire group is heated from the inside of the bent portion to partially remove it. Since the bent state is maintained by contracting, it is not necessary to use a protector, and the bent portion can be formed in the wire harness at low cost.
In addition, the bent portion can be formed regardless of the type of electric wire forming the wire harness. Further, by changing the degree of contraction of the heat-shrinkable sheet according to the size of the bending angle of the wire group, it is possible to cope with the change in the bending angle.

In the wire harness having the bent portion according to the second aspect, since the branch electric wire can be drawn out from the portion cut along the slit or perforation, the heat shrinkable sheet is also wound around the portion where the electric wire group is branched. Therefore, the usable range of the heat shrinkable sheet can be expanded.

In the method for forming a wire harness having a bent portion according to claim 3, a heat shrinkable sheet is wound around the wire group,
Since the bent portion can be formed only by heating the heat shrinkable sheet from the inside of the bent portion to partially shrink the bent portion, the bent portion can be formed by a simple operation.

[Brief description of drawings]

FIG. 1 is a perspective view showing a wire harness having a bent portion according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line IV-IV in FIG. 1, where (A) is a diagram in the case where the electric wire group is composed of less than 10 electric wires, and (B) is composed of 10 or more electric wires. It is a figure when it has become.

FIG. 3A is an enlarged perspective view of a heat-shrinkable sheet in a non-contracted state, and FIG. 3B is an enlarged perspective view of a contracted state.

4 (A), (B), (C), and (D) are diagrams showing a process of forming a bent portion of a wire harness.

FIG. 5 is a perspective view showing a step of forming a bent portion of another wire harness.

FIG. 6 is a plan view showing a first modification of the heat shrinkable sheet.

7A and 7B are views showing a winding process of the heat shrinkable sheet of FIG.

FIG. 8 is a diagram showing a second modification of the heat shrinkable sheet.

FIG. 9 is a perspective view showing a conventional wire harness.

[Explanation of symbols]

 11 Wire harness having bent portions 12, 22, 32 Heat shrinkable sheet 22a Slit 32a Perforation 13 Electric wire group 14 Bent portion 15 Tape 16, 16 'Wiring diagram board 17 Wiring jig 18 Electric wire 20 Jig

Claims (3)

[Claims] 1. A heat-shrinkable sheet is wound around the outer circumference of a bent wire group, and both ends in the length direction of the heat-shrinkable sheet are fixed by tape winding, and the bent state of the wire group is heated by heating. A wire harness having a bent portion held by the contracted heat-shrinkable sheet. 2. The heat-shrinkable sheet is provided with slits or perforations in a direction orthogonal to the lengthwise direction with a required space in the lengthwise direction, and branches are formed from the cut portions along the slits or perforations. The wire harness having a bent portion according to claim 1, wherein the electric wire can be pulled out. 3. An electric wire group is laid along a wire laying jig, a heat shrinkable sheet is wrapped around the outer peripheral surface of a required portion of the laid wire group, and both ends of the wound heat shrinkable sheet in the longitudinal direction. Then, the portion wound with the heat shrinkable sheet is bent at a required angle with the center in the length direction as a fulcrum, and finally, from the inside of the bent portion, the shrinkage temperature of the heat shrinkable sheet or more And a method for forming a wire harness having a bent portion in which the heat-shrinkable sheet is heated at a temperature equal to or lower than the heat resistant temperature of the wire, and the shrinked heat-shrinkable sheet holds the wire group in a bent state.