Exterior sheet, wire harness, and method for manufacturing a wire harness

Abstract

To provide:an exterior sheet that holds a wire more easily and is more suitable for bending; a wire harness; and a manufacturing method for the wire harness.SOLUTION: An outer sheet 10 includes: a flexible sheet member 11 developed in a planar shape; pieces of heat-shrinkable material 12 having higher heat-shrinkability than the sheet member 11, which are formed on one surface side of the sheet member 11; and pieces of adhesive 13, which are each provided on one surface side of the sheet member 11. The pieces of heat-shrinkable material 12 are provided on one surface side of the sheet member 11 at an area ratio of 5% or more and 50% or less of an area of the sheet member 11.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an exterior sheet, a wire harness, and a method for manufacturing a wire harness.

Background Art

[0002] Conventionally, a protective material for an electric wire formed into a cylindrical shape has been proposed by placing an electric wire on a sheet provided with heat-shrinkable yarn and heating it (see, for example, Patent Document 1). Further, a protective material that is heat-shrunk by placing an electric wire on an exterior sheet in which the heat shrinkage rate in the first axial direction is larger than the heat shrinkage rate in the second axial direction orthogonal to the first axial direction and heating it after forming it into a cylindrical shape has been proposed (see, for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, since the heat-shrinkable yarn is used in the protective material described in Patent Document 1, the area of the portion that shrinks thermally is small, the force for maintaining the cylindrical shape becomes weak, and there is a high possibility that the electric wire will protrude from the protective material (exterior member). Further, since the entire sheet is a heat-shrinkable material in the protective material described in Patent Document 2, it becomes hard as a whole during heat shrinkage, and it cannot be said that it is suitable when there is a bending requirement such as during vehicle wiring.

[0005] The present invention has been made to solve such conventional problems, and an object thereof is to provide an exterior sheet, a wire harness, and a method for manufacturing a wire harness that are more easily hold an electric wire and are more suitable for bending. [Means for solving the problem]

[0006] The exterior sheet according to the present invention comprises a flexible sheet member unfolded in a planar shape, and a heat-shrinkable material formed on one side of the sheet member, which has higher heat shrinkability than the sheet member. With the entire circumference of the heat-shrinkable material enclosed The heat-shrinkable material comprises an adhesive provided on one side of the sheet member, wherein the heat-shrinkable material is provided on one side of the sheet member in an area ratio of 5% to 50% of the area of ​​the sheet member.

[0007] The wire harness according to the present invention comprises an electric wire and the outer sheet, wherein the outer sheet is wrapped around the electric wire in a longitudinal manner and has an overlap portion of 5% to 50% when viewed in cross-section with one full turn considered as 100%, and serves as the outer material for the electric wire.

[0008] The method for manufacturing a wire harness according to the present invention comprises a flexible sheet member laid out in a planar shape, a heat-shrinkable material formed on one side of the sheet member in an area ratio of 5% to 50% of the sheet member's area, and having higher heat shrinkability than the sheet member, and With the entire circumference of the heat-shrinkable material enclosed The method comprises: a first step of arranging an exterior sheet having an adhesive provided on one side of the sheet member in a planar shape; a second step of arranging electric wires on the planar exterior sheet arranged in the first step; and a third step of heating the exterior sheet on which the electric wires are arranged in the second step to form a cylindrical shape. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide an outer sheet, a wire harness, and a method for manufacturing a wire harness that are easier to hold electric wires and more suitable for bending. [Brief explanation of the drawing]

[0010] [Figure 1] This is a perspective view showing a wire harness according to an embodiment of the present invention. [Figure 2] This is a cross-sectional view AA in Figure 1. [Figure 3] Figure 1 is a perspective view showing the exterior sheet, which is the exterior component before heating. [Figure 4] This is a perspective view showing a modified example of the exterior sheet according to this embodiment. [Figure 5] This is a first process diagram showing a method for manufacturing a wire harness according to this embodiment. [Figure 6] This is a second process diagram showing a method for manufacturing a wire harness according to this embodiment. [Modes for carrying out the invention]

[0011] The present invention will be described below in accordance with preferred embodiments. It should be noted that the present invention is not limited to the embodiments shown below, and can be modified as appropriate without departing from the spirit of the invention. Furthermore, in the embodiments shown below, some illustrations and descriptions of certain components are omitted. It goes without saying that, regarding the details of the omitted technologies, publicly known or well-known technologies are applied as appropriate, to the extent that they do not contradict the content described below.

[0012] Figure 1 is a perspective view showing a wire harness 1 according to an embodiment of the present invention, and Figure 2 is a cross-sectional view AA of Figure 1. As shown in Figures 1 and 2, the wire harness 1 is composed of electric wires W and an outer covering member P.

[0013] The electric wire W comprises a conductor made of, for example, copper, aluminum, or an alloy thereof, and an insulating covering that covers the conductor. In the example shown in Figure 1, the conductor of the electric wire W is a single wire, but it is not limited to this, and may be a stranded wire made by twisting together multiple strands. Also, in the example shown in Figure 1, there are three electric wires W, but it is not limited to this, and may be provided with two or fewer wires, or four or more wires.

[0014] The exterior member P is a protective member arranged around the electric wire W. This exterior member P is configured to have an abrasion-resistant sheet member 11 (see FIG. 3), and the sheet member 11 protects the electric wire W arranged inside. Here, in the present embodiment, the exterior member P is changed into a cylindrical shape by heat shrinkage due to heating and is wound around the electric wire W in a longitudinally attached state, protecting the electric wire W while maintaining the cylindrical shape without the need for an adhesive tape.

[0015] FIG. 3 is a perspective view showing an exterior sheet in a state before heating of the exterior member P shown in FIG. 1. As shown in FIG. 3, the exterior sheet 10 includes a sheet member 11, a heat-shrinkable material 12, and an adhesive 13. Note that in the state before heating, the sheet member 11 of the exterior sheet 10 is in a state of being unfolded flat.

[0016] The sheet member 11 is flexible and is composed of an abrasion-resistant sheet that can withstand a predetermined amount of wear. The sheet member 11 is composed of, for example, polyolefin resins such as polypropylene and polyethylene, polyethylene terephthalate, polyurethane, and polyvinyl chloride (PVC).

[0017] It is preferable that this sheet member 11 ensures a thickness of 0.2 mm or more and has an abrasion resistance of 150 mm or more in an abrasion resistance test. Here, it is preferable that the sheet member 11 has a more ensured thickness and has an abrasion resistance of 500 mm or more, and more preferably 1000 mm or more. Furthermore, it can be said that it is even more preferable that the abrasion resistance of the sheet member 11 is 1500 mm or more. Note that the thickness of the sheet member 11 is preferably 2.0 mm or less so that the wire harness 1 does not become too hard. In addition, it is preferable that the tensile elongation is 50% or more so as to be able to cope with bending of the wire harness 1.

[0018] Note that the abrasion resistance test here is performed by attaching a test piece (sheet member 11) of appropriate length to an aluminum pipe with a diameter of φ10 mm and setting it on an abrasion resistance tester specified in JASO D 608. With a load of 4.4 N applied to the test piece, the abrasion tape is moved at a speed of 1500 mm / min. The moving distance of the abrasion tape until it contacts the aluminum pipe is the value indicating the abrasion resistance.

[0019] The heat shrinkable material 12 has at least a higher heat shrinkability than the sheet member 11 and is provided on one side of the sheet member 11. Such a heat shrinkable material 12 is composed of PFA (perfluoroalkoxy fluororesin), FEP (ethylene tetrafluoride - propylene hexafluoride copolymer), or the like.

[0020] Also, the heat shrinkable material 12 has a long shape, and a plurality of them are arranged in parallel with respect to the sheet member 11. Therefore, when the heat shrinkable material 12 is heated, it greatly shrinks in the longitudinal direction and curls so that the longitudinal direction becomes the circumferential direction (see the arrow in FIG. 3).

[0021] The adhesive 13 is provided on one side of the sheet member 11 and is preferably composed of a hot melt adhesive. This adhesive 13 is provided in a laminated state on the heat shrinkable material 12 having a long shape as shown in FIG. 3.

[0022] Furthermore, the heat shrinkable material 12 according to the present embodiment is provided on one side of the sheet member at an area ratio of 5% or more and 50% or less of the area of the sheet member 11. For this reason, it prevents a situation where the heat shrinkable material 12 is too little, as when it is less than 5%, and it becomes difficult to maintain a cylindrical state after heating and the electric wire W cannot be held. Also, it prevents a situation where the heat shrinkable material 12 that has become hard due to heat shrinkage occupies a large area, as when it exceeds 50%, and the wire harness 1 becomes extremely difficult to bend.

[0023] In addition, as shown in Figure 2, the wire harness 1 according to this embodiment has an outer covering member P whose circumferential ends overlap, forming an overlapping portion R. More specifically, the overlapping portion R is set to be between 5% and 50% when viewed in cross-section, with one full turn being considered 100%. This reduces the possibility of the wire harness 1 opening up and exposing the wires W when bent, as would occur if the overlapping portion R were less than 5%. It also reduces the possibility of the wire harness 1 becoming difficult to bend due to a large overlapping portion R, as would occur if the overlapping portion R were greater than 50%.

[0024] Figure 4 is a perspective view showing a modified example of the exterior sheet 10 according to this embodiment. As shown in Figure 4, the adhesive 13 (hot melt adhesive) may be configured to surround the entire circumference of the heat shrink material 12. In this configuration, the adhesive 13 can also be used to join the sheet member 11 and the heat shrink material 12.

[0025] Next, the manufacturing method of the wire harness 1 according to this embodiment will be described. Figure 5 is a first process diagram showing the manufacturing method of the wire harness 1 according to this embodiment. As shown in Figure 5, first, a flat hot plate HP is prepared (see reference numeral A1). Next, the outer sheet 10 is placed on the hot plate HP (see reference numeral A2: first step). The outer sheet 10 is unfolded into a flat shape.

[0026] Next, the electric wires W are placed perpendicular to the longitudinal direction of the multiple heat-shrinkable materials 12 provided on the sheet member 11 (see symbol A2: second step).

[0027] Subsequently, the hot plate HP is heated (see symbol A3). This heats the heat-shrinkable material 12 of the outer sheet 10 placed on the hot plate HP (third step). Due to this heating, the outer sheet 10 deforms into a cylindrical shape to become the outer member P (see symbols A3, A4: third step).

[0028] As a result, a wire harness 1 with an exterior member P can be manufactured without the need to wrap an exterior sheet 10 or apply tape.

[0029] Figure 6 is a second process diagram showing a method for manufacturing the wire harness 1 according to this embodiment. The wire harness 1 may be manufactured as follows. First, as shown in Figure 6, the outer sheet 10 is arranged in a planar manner (see reference numeral B1: first step). Next, the electric wires W are placed on the sheet member 11 so as to be perpendicular to the longitudinal direction of the plurality of heat-shrinkable materials 12 provided on the sheet member 11 (see reference numeral B2: second step). At this time, a drying oven D is installed on the opposite side of the outer sheet 10 with the electric wires W in between.

[0030] Next, high-temperature air is blown from the drying oven D toward the outer sheet 10 (see symbol B3). This heats the heat-shrinkable material 12 of the outer sheet 10, causing the outer sheet 10 to deform into a cylindrical shape and become the outer member P (see symbols B3, B4: third step).

[0031] As a result, a wire harness 1 with an exterior member P can be manufactured without the need to wrap an exterior sheet 10 or apply tape.

[0032] Next, an embodiment of the exterior member P according to this embodiment will be described in detail.

[0033] First, a PVC sheet (vinyl sheet manufactured by Nitto Denko) was used as the sheet material in the embodiment. Electron beam crosslinked flexible polyolefin resin (SUMITUBE A manufactured by Sumitomo Electric Industries) was used as the heat-shrinkable material. A hot-melt adhesive (1540 manufactured by Yasuhara Chemical) was used as the adhesive. For the heat-shrinkable material and adhesive, the heat-shrinkable material coated with adhesive was first cut into strips to form long pieces. These strips were then arranged on the sheet material with the same arrangement direction and fixed to the sheet material with the other adhesive. The heat-shrinkable material was 3.0 mm thick or less, and the hot-melt adhesive was 3 μm thick or less.

[0034] When abrasion resistance tests were conducted on these exterior sheets under the conditions described above, the abrasion resistance was 150 mm or more but less than 500 mm when the sheet material thickness was 0.2 mm. When the sheet material thickness was 0.3 mm, the abrasion resistance was 500 mm or more but less than 1000 mm. Furthermore, when the sheet material thickness was 0.4 mm, the abrasion resistance was 1000 mm or more.

[0035] Thus, according to the exterior sheet 10 of this embodiment, since the heat-shrinkable material 12 is 5% or more of the area of ​​the sheet member 11, the amount of heat-shrinkable material 12 is not too small, and the holding force to hold the inner wire W after deformation into a cylindrical shape by the heat-shrinkable material 12 can be secured. Furthermore, since the heat-shrinkable material 12 is 50% or less of the area of ​​the sheet member 11, it is possible to prevent it from becoming too hard after heat shrinkage, making it difficult to apply at bending points. Therefore, it is possible to make it easier to hold the wire W and more suitable for bending.

[0036] In addition, since the heat-shrinkable material 12 can be used to form a cylindrical outer component P by heating, there is no need for the process of wrapping the outer sheet 10 or wrapping it with tape. Furthermore, by using the adhesive 13, there is no need to use double-sided tape, and it is possible to eliminate the need for release paper.

[0037] Furthermore, since the heat-shrinkable material 12 is in a long shape and multiple pieces are arranged in parallel with respect to the sheet member 11, the sheet member 11 can be rolled up in the longitudinal direction of the heat-shrinkable material 12 arranged in parallel by heating. This eliminates the need to use a heat-shrinkable material that shrinks in a uniaxial direction, for example, and contributes to expanding the range of applications for the heat-shrinkable material 12.

[0038] Furthermore, since the adhesive 13 is provided in a laminated state on the long, heat-shrinkable material 12, efficient bonding can be achieved by applying the adhesive 13 to the heat-shrinkable portion.

[0039] Furthermore, since the adhesive 13 is a hot-melt adhesive, it does not interfere with heating, which can prevent situations such as the adhesive 13 adhering to unintended locations.

[0040] Furthermore, according to the wire harness 1 of this embodiment, the outer sheet 10 is wrapped around the electric wire W in a longitudinal manner and has an overlapping portion R of 5% to 50% when viewed in cross-section with one full turn considered as 100%, and serves as the outer covering member P for the electric wire W. Therefore, the possibility of the overlapping portion R being less than 5% and opening up when bent, exposing the electric wire W, can be reduced. Also, because the overlapping portion R is 50% or less, the possibility of the wire harness 1 becoming too stiff and difficult to apply at bending points can be reduced.

[0041] Furthermore, according to the manufacturing method of the wire harness 1 of this embodiment, since the outer sheet 10 on which the electric wires W are arranged is heated to form a cylindrical shape, the process of winding the outer sheet 10 can be eliminated. Also, since the outer sheet 10 has adhesive 13, the process of fixing it after winding can also be eliminated. As a result, manual work related to this can be omitted, leading to automation when providing the outer member P. Moreover, since the heat shrink material 12 is formed with an area ratio of 5% to 50% of the area of ​​the sheet member 11, it is possible to ensure the holding force that holds the electric wires W inside after deformation into a cylindrical shape by the heat shrink material 12, and it is possible to prevent it from becoming too hard after heat shrinkage, making it difficult to apply at bending points.Therefore, a wire harness that is easier to hold the electric wires W and more suitable for bending can be manufactured in a state closer to automation.

[0042] Although the present invention has been described above based on embodiments, the present invention is not limited to the above embodiments, and modifications may be made without departing from the spirit of the invention, and if possible, publicly known or well-known technologies may be combined.

[0043] For example, in this embodiment, the heat-shrinkable material 12 is long and cylindrical in shape so that its longitudinal direction becomes the circumferential direction when heated. However, it is not limited to a long shape, and for example, the heat-shrinkable material 12 may be provided that shrinks in one axial direction. [Explanation of symbols]

[0044] 1: Wire harness 10: Exterior seats 11: Sheet material 12: Heat shrinkable material 13: Adhesive P: Exterior components R: Wrap section W: Electric wire

Claims

1. A flexible sheet member unfolded in a planar shape, A heat-shrinkable material formed on one side of the sheet member, which has higher heat shrinkability than the sheet member, The sheet member comprises an adhesive provided on one side of the sheet member, surrounding the entire circumference of the heat-shrinkable material, The heat-shrinkable material is provided on one side of the sheet member in an area ratio of 5% to 50% of the sheet member's area. An exterior seat characterized by the following features.

2. The heat-shrinkable material is in a long shape, and multiple pieces are arranged in parallel with the sheet member. The exterior sheet according to feature 1.

3. The adhesive is a hot melt adhesive. The exterior sheet according to either claim 1 or claim 2.

4. Power lines and, The electric wire comprises an outer sheet according to any one of claims 1 to 3 that covers the periphery of the electric wire, The outer sheet is wrapped around the electric wire in a longitudinal position and, when viewed in cross-section, has an overlap portion of 5% to 50% when one full turn is considered 100%, thus serving as the outer covering member for the electric wire. A wire harness characterized by the following features.

5. A first step involves arranging an exterior sheet in a planar manner, which has a flexible sheet member unfolded in a flat shape, a heat-shrinkable material formed on one side of the sheet member in an area ratio of 5% to 50% of the sheet member's area and having higher heat shrinkability than the sheet member, and an adhesive provided on one side of the sheet member, surrounding the entire circumference of the heat-shrinkable material. A second step involves arranging electric wires on the planar exterior sheet arranged in the first step, A third step involves heating the outer sheet on which the electric wires are arranged in the second step to form a cylindrical shape, A method for manufacturing a wire harness, characterized by comprising the following features.

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