JP2017011813A - Branch part protection structure for wiring harness - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely protect a branch part of a wiring harness with one protective sheet.SOLUTION: A super-oriented polyethylene sheet including a sticking surface coated with an adhesive material in one surface is used as a protective sheet. The protective sheet is easily flexible in a direction along a molecule orientation direction (MD direction), on the other hand, has hard flexibility in a direction (TD direction) orthogonal with the molecule orientation direction and has a shape holding force in a folded state in a three-dimensional shape. The protective sheet is formed by providing a rectangular main body part matching the molecule orientation direction to a length direction of a wire group of a wiring harness, and overlapped winding parts which protrude in a width direction at both sides of the main body part in the length direction. A central portion of the main body part in the width direction is wound at a trunk line continuation side opposite to a branch line branch side of a branch position of the wiring harness, and both side portions in the width direction are wound at the branch line branch side while interposing a branch line therebetween and adhered to the wire group of the wiring harness by the sticking surface at an inner surface side of the main body part. The overlapped winding parts at both the sides are wound around and adhered to an outer surface of the main body part in such a manner that a clearance between distal ends in the width direction of the main body part is closed.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a branch protection structure for a wire harness, and more particularly, to protect an electric wire group by attaching an exterior material to the electric wire group at a portion where the branch line branches from a trunk line of a wire harness routed in an automobile.

  In many cases, a wire harness that focuses this type of wire group binds and protects the wire group by winding an adhesive tape around the outer periphery of the wire group. In this case, the adhesive tape is obliquely wound from one side to the other side of the trunk line sandwiching the branch position, and there is a problem that the electric wire on which the adhesive tape cannot be wound is exposed to the outside and the electric wire group cannot be sufficiently protected. .

  In recent years, the number of cases in which a corrugated tube having flexibility is covered and protected by focusing on an electric wire group is increasing. When the corrugated tube is covered, there is a problem that at the branch point where the branch line branches off from the main line, the branch line protrudes from the main line and cannot be continuously covered with the corrugated tube.

  With respect to the above problem, the present applicant has provided a protection structure for a wire harness branching portion shown in FIGS. 7 (A) to 7 (E) in Japanese Patent Laid-Open No. 2013-255312. In the protective structure, slits 110s and 120s in the longitudinal direction are provided on the corrugated tubes 110 and 120 on both sides of the main line 100 sandwiching the branching position, respectively, from the leading end of the branch, and partially divided pieces 110a and 120a divided by the slits. Is pressed against the outer peripheral surface of the branch line 150, the remaining divided pieces 110b and 120b are overlapped on the outer peripheral surface of the main line 100, and the main line 100 and the branch line 150 at the branch position are covered with a corrugated tube for protection.

  Further, in the Japanese Patent Application Laid-Open No. 2006-254596, the present applicant cuts the resin tube in the axial direction to form a square in an unfolded shape, and folds the square protective material 200 in a triangular shape, as shown in FIG. Then, the trunk line 100 and the branch line 150 at the branch position are covered, and the adhesive tape 160 is wound around both ends and the branch line of the trunk line to protect the trunk line and the branch line at the branch position.

JP 2013-255312 A JP 2006-254596 A

  In Patent Document 1, a general-purpose corrugated tube is used, slits are provided in the corrugated tubes on both sides of the trunk line across the branch line, and split pieces are provided to cover the trunk line and branch line at the branch position of the wire harness. Although it is supposed to be possible, it is necessary to select the corrugated tube size according to the sizes of the branch line and the trunk line, and to set the size of the divided pieces appropriately, which requires time and effort. In addition, with the corrugated tubes on both sides attached, it is necessary to wrap and bond the adhesive tape around the corrugated tube, and to fix the tip of the split piece to the branch wire with tape, and the wiring harness installation work is also troublesome There is.

  Even when the resin tube of Patent Document 2 is cut and covered as a square protective material in a triangular shape at the branch position, it is necessary to wrap and attach each end to the wire group with an adhesive tape, which requires a lot of work. .

  The present invention intends to solve the above-described problem, and an object of the present invention is to easily and surely protect an electric wire group with an exterior material so that the electric wire is not exposed at a branch position where the branch line branches from the main line.

In order to solve the above problems, the present invention uses a polyethylene super-stretched sheet having a glue surface coated with an adhesive material as a protective sheet, and the protective sheet is easy in the direction along the molecular orientation direction (MD direction). In the direction perpendicular to the molecular orientation direction (TD direction) and has a shape retention force in a state of being bent into a three-dimensional shape,
The protective sheet is provided with a rectangular main body portion in which the molecular orientation direction is aligned with the length direction of the wire group of the wire harness, and a lap winding portion projecting in the width direction on both sides of the main body portion in the length direction. Shape
Wrapping the central part in the width direction of the main body part around the main line continuation side opposite to the branch line branch side of the branch position of the wire harness, and winding both sides in the width direction on the branch line branch side with the branch line interposed therebetween Adhering to the wire group of the wire harness with the glue surface on the inner surface side of the part, and
Provided is a wire harness branching protection structure in which the lap winding portions on both sides are wound around and adhered to the outer surface of the main body so as to close a gap between the widthwise ends of the main body.

  A registered trademark “Forte” manufactured by Sekisui Molding Co., Ltd. is suitably used as a protective sheet made of the polyethylene ultra-stretched sheet wound around the wire harness and used as an exterior material. The polyethylene ultra-stretched sheet made of the “forte” has a polyethylene molecule whose orientation is controlled in a uniaxial direction in the MD direction, and as described above, can be easily bent along the MD direction to change its shape. It has a unique function that can hold the shape. The ultra-stretched polyethylene sheet made of “Forte” has a thickness of 0.4 mm or more, a tensile modulus (GPa) of 12 or more, a tensile strength (MPa) of 54 or more, high strength and high rigidity, and a specific gravity. It has the advantage of being light weight at 1 or less.

The polyethylene ultra-stretched sheet made of “forte” can be easily bent in the MD direction along the outer periphery of the trunk line and can be held in the bent state. For example, a 90 degree bend has a return angle of 0 ° to 3 ° with almost no bend return, and has a shape-rich property capable of retaining the shape in a bent state. In addition, since the cut end is rounded and no edge is generated, safety during work is high.
In the present invention, when bending along the outer peripheral surface of the electric wire group, "Forte" having a shape retention force that hardly bends back is used as a protective sheet, and since one surface is a glue surface, it is only wound and strongly bonded. Thus, the winding state can be maintained. Therefore, it is possible to eliminate the work of winding the tape and maintaining the wound state, which has been conventionally required, and to greatly simplify the number of work.

The branch protection structure for a wire harness of the present invention is suitably used for a T-shaped branch in which a branch line branches from one side to the other side.
In addition, in the cross-branch in which the branch line branches from both sides of the trunk line, a hole is formed in the center of the main body of the protective sheet, and when the branch line branched from the trunk line to the other side is penetrated, the electric wire group is It can be protected without exposure.

  As described above, in the branch protection structure of the wire harness of the present invention, the protective sheet is made of a super-stretched polyethylene sheet that has a shape retaining force without returning in a bent state and one side is a glue surface coated with an adhesive. Therefore, the protective sheet can be adhered to the electric wire group only by covering the electric wire group without wrapping around the trunk line of the wire harness and leaving a gap along the base of the branch line. In this way, since it is only necessary to wrap one protective sheet, the protective work of the branch portion can be simplified. And since there is no edge like a corrugated tube, it has various advantages, such as not damaging an electric wire group.

The protection sheet used for 1st Embodiment of this invention is shown, (A) is a perspective view, (B) is the BB sectional drawing of (A). It is a perspective view which shows the relationship between the said protection sheet and the branch part of a wire harness. The process of winding the branch part of a wire harness around the said protection sheet is shown, (A) is a perspective view, (B) is a top view of (A). The state which protected the branch part of the wire harness with the said protection sheet is shown, (A) is a perspective view, (B) is a top view, (C) is CC sectional view taken on the line of (B). It is a top view which shows the modification of the protection sheet of 1st Embodiment. A 2nd embodiment is shown, (A) is a figure showing a cross of a wire harness, and (B) is a top view of a protection sheet. (A)-(E) are drawings which show a prior art example. It is drawing which shows another prior art example.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 to 4 show a first embodiment.
In the first embodiment, one wire group 1W of the trunk line 1 and one wire group 2W of the branch line 2 at the position where the branch line 2 branches in a T shape from the trunk line 1 of the wire harness W / H wired in the automobile. The protective sheet 10 is covered.

  The protective sheet 10 is obtained by cutting a polyethylene super-stretched sheet having an adhesive material applied to one side of the sheet to form a glue surface 10a into a shape shown in FIG. A registered trademark “Forte” manufactured by Sekisui Molding Co., Ltd. is suitably used as the polyethylene ultra-stretched sheet. The polyethylene super-stretched sheet made of the “forte” easily bends in the direction along the molecular orientation direction (MD direction), and has a poor flexibility in the direction orthogonal to the molecular orientation direction (TD direction), and It has shape retention in a state where it is folded into a three-dimensional shape. Further, it has a thickness of 0.4 mm or more, a tensile modulus (GPa) of 12 or more, a tensile strength (MPa) of 54 or more, high strength and high rigidity similar to those of a metal plate, and a specific gravity of 1 or less. Light weight. The protective sheet 10 of the present embodiment has a thickness of 0.4 mm. In addition, the return angle is 0 ° to 3 ° after 90 ° bending, and there is almost no bending return, and the shape can be maintained in the bent state, and the shape is rich. Moreover, since the cut end is rounded and no edge is generated, safety is high.

  Since the protective sheet 10 has one surface as a glue surface 10a and has a shape holding force in a state of being wound around the outer periphery of the electric wire group, the protective sheet 10 can be attached to the conventional sheet only by pressing the adhesive surface 10a around the outer peripheral surface of the electric wire group. Thus, it can be attached to the electric wire group without being wrapped with an adhesive tape.

  As shown in FIG. 1 (A), the protective sheet 10 has a rectangular main body portion 11 in which the molecular orientation direction (MD direction) is matched with the length direction of the wire group 1W of the main wire 1 of the wire harness, and the main body portion. 11 is provided with lap winding portions 12 and 13 projecting in the width direction Y on both sides of the length direction X of the eleventh. The overlapping winding part 12 protrudes to one side in the width direction Y of the main body part 11, and the other overlapping winding part 13 protrudes to the other side. The lengthwise interval L1 between the overlapping winding portions 12 and 13 on both sides corresponds to the diameter of the branch wire 2, and the edge 12e of the overlapping winding portion 12 abuts on one side of the branch wire 2 in the diameter direction. The end edge 13e of the lap winding portion 13 is in contact with the other side of the line 2.

  The dimension of the main body 11 of the protective sheet 10 in the width direction Y is a dimension obtained by subtracting the diameter dimension of the branch line 2 from the outer peripheral length of the trunk line 1, and the dimension in the length direction X is 3 of the diameter of the branch line 2. About 5 times. The center in the length direction X of the main body 11 of the protective sheet 10 is aligned with the position where the branch line 2 branches from the main line 1 and the center in the width direction Y is positioned on the main line continuous side opposite to the branch line protruding side. Then, when the main body part 11 is wound around the outer periphery of the main line 1 toward the branch line protruding side, both side edges of the main body part 11 are located at the root of the branch line 2 and both sides of the main line 1 sandwiching the branch line 2 Thus, the main body 11 is wound around with a gap corresponding to the diameter of the branch line 2.

  The method of covering and protecting the T-shaped branching portion where the branch line 2 branches from the main line 1 using the protective sheet 10 is as shown in FIG. 3 with the glue surface 10a as a winding surface of the main line 1 around the electric wire group 1W. The main body 11 is wound while being pressed against the outer peripheral surface of the electric wire group 1W. As described above, the winding is performed by aligning the center in the length direction X of the main body portion 11 with the position where the branch line 2 branches from the main line 1 and continuing the center in the width direction Y on the side opposite to the branch line protruding side. The main body part 11 is wound toward the branch line projecting side along the outer periphery of the trunk line 1. As a result, the side edges 11e and 11f of the main body 11 are positioned at the root of the branch line 2, and the main body is opened with gaps C1 and C2 corresponding to the diameter of the branch line 2 on both sides of the trunk line 1 sandwiching the branch line 2. The part 11 is wound and adheres to the wire group 1W with the glue surface 10a.

Next, the overlapping winding portion 12 on one side in the length direction is covered with the gap C1 and then wound around the outer peripheral surface on one side in the length direction of the main body portion 11 and wound around the main line 1 with the glue surface of the overlapping winding portion 12. It adheres to the outer peripheral surface of the main body 11.
Similarly, the overlapping winding portion 13 on the other side in the length direction is covered with the outer peripheral surface on the other side in the length direction of the main body portion 11 after covering the gap C <b> 2, and is applied to the trunk line 1 by the glue surface of the overlapping winding portion 13. It adheres to the outer peripheral surface of the wound main body 11.
Edges 12e and 13e in the length direction of the wound portions 12 and 13 are adhered to positions in contact with both side surfaces of the wire group 2W of the branch wire 2.

When the protective sheet 10 is wound, as shown in FIGS. 4A to 4C, the outer peripheral surface of the main line 1 is completely covered with the protective sheet 10 and branches from the main line 1 at the branch position of the wire harness. The roots of the branch wires 2 are covered with the protective sheet 10 without gaps, so that the exposure of the wire group at the branching portion can be reliably prevented, and the wire group can be protected and the appearance can be improved.
Moreover, it is only necessary to wrap one protective sheet 10 around the electric wire group, and since the protective sheet 10 can be self-held in the wound state, it is possible to eliminate the need for winding the adhesive tape, and to reduce the number of work and parts costs. .
Furthermore, since the protection sheet 10 has high rigidity and high strength, the protection performance of the electric wire group at the branch portion can be enhanced.

FIG. 5 shows a modification of the first embodiment.
In the modification, the overlapping winding portions 12 and 13 protruding from the main body portion 11 of the protective sheet 10 are provided so as to protrude from the same direction in the width direction Y. Even if the lap winding portions 12 and 13 protrude from the same width direction end of the main body portion 11, the lap winding portions 12 and 13 are wound so as to close the gap generated when the main body portion 11 is wound around the main line 1. be able to.

6A and 6B show a second embodiment.
In the second embodiment, the cross branch portion of the wire harness shown in FIG.
In the cross-branching portion, branch lines 2A and 2B are branched from both sides of the trunk line 1.
The protective sheet 10 is a polyethylene super-stretched sheet made of the same “forte” as in the first embodiment, and the shape is substantially the same as that in the first embodiment. , 13 project in the width direction.

  A hole 15 that penetrates the branch line 2B is provided in the center in the length direction and the width direction of the main body 11, and this point is different from the protection sheet 10 of the first embodiment.

After passing one branch line 2B through the hole 15 of the protective sheet 10, the main body part 11 is wound around the outer peripheral surface of the trunk line 1, and then the wrap-around parts 12 and 13 are wound around the branch part of the wire harness. Protect with.
Thereby, the cross-branching part can also be protected without exposing the electric wire with the single protective sheet 10.

DESCRIPTION OF SYMBOLS 1 Trunk line 2 Branch line 10 Protection sheet 10a Glue surface 11 Main-body part 12, 13 Overwrapping part

Claims (1)

A polyethylene ultra-stretched sheet with an adhesive material coated on one side is used as a protective sheet. The protective sheet is easily bent in the direction along the molecular orientation direction (MD direction), but orthogonal to the molecular orientation direction. Having a bending resistance in the direction (TD direction) and having a shape retention force in a state of being folded into a three-dimensional shape,
The protective sheet is provided with a rectangular main body portion in which the molecular orientation direction is aligned with the length direction of the wire group of the wire harness, and a lap winding portion projecting in the width direction on both sides of the main body portion in the length direction. Shape
Wrapping the central part in the width direction of the main body part around the main line continuation side opposite to the branch line branch side of the branch position of the wire harness, and winding both sides in the width direction on the branch line branch side with the branch line interposed therebetween Adhering to the wire group of the wire harness with the glue surface on the inner surface side of the part, and
A branch protection structure for a wire harness in which the lap winding portions on both sides are wound around and adhered to the outer surface of the main body so as to close a gap between the front ends in the width direction of the main body.

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