Wire harness

Abstract

To provide a wire harness capable of imparting a protection function to an electric wire portion having a flat shape while securing high flexibility.SOLUTION: A wire harness 1 includes: an electric wire portion 2 including an insulated wire and having a flat shape, the cross-section of which has a dimension in a width direction larger than a dimension in a height direction; a pair of exterior materials 3 arranged in contact with each surface 2a on both sides in the height direction of the electric wire portion 2; and a fixed member 4 for fixing the pair of exterior materials 3 with each other in a state of sandwiching the electric wire portion 2 therebetween. The electric wire portion 2 includes one insulated wire configured as a flat wire or includes a plurality of the insulated wires assembled together. The exterior members 3 are formed of a material having a tensile elastic modulus higher than that of an insulated cover, and having bending flexibility higher than that of the electric wire portion in the height direction. The fixed member 4 fixes the pair of exterior materials 3 to each other at a plurality of fixing points provided at intervals along an axial direction of the electric wire portion 2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a wire harness. [Background technology]

[0002] A flat electric wire constructed using a flat conductor is known. The use of a flat electric wire can reduce the space occupied during installation compared to a general electric wire having a conductor with a substantially circular cross section. For example, as a flat electric wire that combines space saving and flexibility, Patent Documents 1 and 2 filed by the applicant disclose an insulated electric wire in which a wire conductor formed by twisting together a plurality of elemental wires and forming the twisted wire into a flat shape is used.

[0003] Furthermore, conventionally, an outer covering material has been used to protect an insulated wire from contact with or collision with external objects. One known type of outer covering material is a corrugated tube, which is made of a resin material molded into a tubular shape with a bellows structure. As shown in FIGS. 3A and 3B, flat wires may also be protected by inserting the flat wire 2 into a flat corrugated tube 8. Such an embodiment using a flat corrugated tube is disclosed in, for example, Patent Document 3. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2019 / 093309 [Patent Document 2] International Publication No. 2019 / 093310 [Patent Document 3] Japanese Patent Application Laid-Open No. 2012-249506 Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, using a corrugated tube 8 formed into a flat shape as shown in FIGS. 3A and 3B can provide a protective function for the flat electric wire 2. However, the flat corrugated tube 8 hinders the bending flexibility of the flat electric wire 2. In particular, when the flat electric wire 2 is inserted into the flat corrugated tube 8 and the assembly is bent in the width direction (edge ​​direction; x direction) of the flat electric wire, a large force is required for bending. As a result, when a wiring harness 9 in which the flat electric wire 2 is inserted into the corrugated tube 8 is to be assembled in a predetermined location, such as inside an automobile, it becomes difficult to easily bend the wire at locations along the route where bending is required. Even if the flat electric wire 2 is formed to have high flexibility, as disclosed in Patent Documents 1 and 2, for example, the flexibility cannot be fully utilized in routing.

[0006] Therefore, an object of the present invention is to provide a wire harness that can provide a protective function to a flattened electric wire portion while ensuring high flexibility. [Means for solving the problem]

[0007] The wire harness of the present disclosure includes one or more insulated electric wires each having a conductor and an insulating coating covering the outer periphery of the conductor, and includes an electric wire portion having a flattened cross section perpendicular to the axial direction in which the width dimension is greater than the height dimension, a pair of exterior materials arranged in contact with both sides of the electric wire portion in the height direction, and a fixing member that fixes the pair of exterior materials to each other with the electric wire portion sandwiched therebetween, wherein the electric wire portion includes one insulated electric wire configured as a flat wire or a group of multiple insulated electric wires, the exterior material is made of a material having a higher tensile modulus than the insulating coating and has higher bending flexibility in the height direction than the electric wire portion, and the fixing member fixes the pair of exterior materials to each other at multiple fixing points provided at intervals along the axial direction of the electric wire portion. [Effects of the Invention]

[0008] The wire harness according to the present disclosure is a wire harness that can provide a protective function to a flattened electric wire portion while ensuring high flexibility. [Brief explanation of the drawings]

[0009] [Figure 1] 1A and 1B are a perspective view and a side view, respectively, of a wire harness according to one embodiment of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view showing a wire harness according to an embodiment of the present disclosure. [Figure 3] 3A and 3B are a perspective view and a side view, respectively, showing a conventional wire harness using a flat corrugated tube. [Figure 4] FIG. 4 is a cross-sectional view showing a conventional wire harness using a flat corrugated tube. [Figure 5] FIG. 5 is a perspective view showing an integrated exterior material constituting a wire harness according to one modified embodiment. [Figure 6] FIG. 6 is a side view illustrating a method for evaluating the amount of hanging of the electric wire. [Figure 7] Figure 7 is a photograph comparing the amount of sagging of a wire harness (H1) using a bellows sheet and a wire harness (H2) using a corrugated tube. [Figure 8] Figures 8A and 8B are graphs comparing the amount of sagging of various samples, with Figure 8A showing bending in the height direction and Figure 8B showing bending in the width direction. DETAILED DESCRIPTION OF THE INVENTION

[0010] [Description of the embodiments of the present disclosure] First, embodiments of the present disclosure will be listed and described. A wire harness according to the present disclosure includes one or more insulated electric wires each having a conductor and an insulating coating covering the outer periphery of the conductor, and includes an electric wire portion having a flattened cross section perpendicular to the axial direction in which the width dimension is greater than the height dimension, a pair of exterior materials arranged in contact with both sides of the electric wire portion in the height direction, and a fixing member that fixes the pair of exterior materials to each other with the electric wire portion sandwiched therebetween, wherein the electric wire portion includes one insulated electric wire configured as a flat wire or a group of multiple insulated electric wires, the exterior material is made of a material having a higher tensile modulus than the insulating coating and has higher bending flexibility in the height direction than the electric wire portion, and the fixing member fixes the pair of exterior materials to each other at multiple fixing points provided at intervals along the axial direction of the electric wire portion.

[0011] The above-mentioned wire harness includes an exterior material in contact with both height-direction surfaces of the flat-shaped electric wire portion. Both height-direction surfaces, which occupy a large area of ​​the flat-shaped electric wire portion, are covered with an exterior material made of a material having a higher tensile modulus than the insulating coating constituting the electric wire portion, thereby effectively protecting the electric wire portion from contact with or collision with external objects. At the same time, the exterior material exhibits higher bending flexibility than the electric wire portion in a direction corresponding to the height direction of the electric wire portion, thereby providing the wire harness with high flexibility. Furthermore, since the fixing members that fix the pair of exterior materials to each other are spaced apart along the axial direction, the high flexibility of the exterior material is unlikely to be impaired even when fixed by the fixing members. As a result, the wire harness exhibits high overall flexibility while maintaining high protection performance. This allows the wire harness to be easily bent at locations that require bending when installed inside an automobile, etc., resulting in high workability during installation.

[0012] Here, the exterior material may also have higher bending flexibility in the width direction than the electric wire portion, which makes it easier to particularly increase the bending flexibility of the wire harness in the width direction.

[0013] Preferably, each of the pair of exterior materials is configured as a sheet material having a bellows structure with irregularities along the axial direction of the electric wire portion. By providing the exterior material with a bellows structure, the exterior material can exhibit high bending flexibility even when the exterior material is made of a material having a high tensile modulus and exhibiting high protective performance. As a result, excellent bending flexibility can be ensured in the wire harness.

[0014] Preferably, the amount of sagging when the wire harness is supported in the horizontal direction is 70% or more in both the width direction and the height direction of the amount of sagging when the electric wire portion is supported alone in the horizontal direction, so that the bending flexibility of the electric wire portion is not significantly impaired by the installation of the exterior material, and the wire harness as a whole has excellent bending flexibility in both the width direction and the height direction.

[0015] The fixing member may be made of a tape having higher flexibility than the exterior material, so that the pair of exterior materials can stably hold the electric wires sandwiched between them while maintaining high bending flexibility of the entire wire harness, thereby effectively protecting the electric wires.

[0016] In this case, the fixing member may be wound around the outer periphery of the assembly of the pair of exterior materials and the electric wire portion in a spiral shape with gaps between turns along the axial direction of the electric wire portion, which makes it possible to easily fix the pair of exterior materials to each other at multiple fixing points provided at intervals.

[0017] The fixing member may not contact the electric wire portion at a position along the axial direction of the electric wire portion other than the end portion of the exterior material, thereby making it less likely that the fixing member will hinder flexible bending of the electric wire portion.

[0018] Preferably, each of the pair of exterior materials has a dimension in the width direction larger than that of the electric wire portion. This allows the exterior materials to effectively protect both sides of the electric wire portion in the height direction. At the same time, the both sides of the electric wire portion in the width direction can also be protected to some extent from contact with external objects. Furthermore, by utilizing the portions of the exterior materials that protrude outward in the width direction from the electric wire portion, the exterior materials can be easily fixed to each other using fixing portions.

[0019] The insulated wire may be a flat wire having a flat conductor formed by twisting together a plurality of wires into a flat shape, whereby the conductor has high flexibility in the height direction and the width direction, thereby making the wire harness excellent in flexibility.

[0020] [Details of the embodiments of the present disclosure] An insulated electric wire and a wire harness according to an embodiment of the present disclosure will be described in detail below with reference to the drawings. In this specification, with respect to the shape of each part of a wire harness, concepts such as straight, parallel, and perpendicular that indicate the shape and arrangement of components include deviations from the geometric concepts within the range allowable for this type of wire harness, such as deviations of approximately ±15% in length and approximately ±15° in angle. In this specification, unless otherwise specified, the cross section of a wire harness, electric wire, or exterior material refers to a cross section cut perpendicular to the axial direction (longitudinal direction). Furthermore, various properties are values ​​evaluated at room temperature in the atmosphere.

[0021] <Outline of wire harness> 1A, 1B, and 2 show the structure of a wire harness 1 according to one embodiment of the present disclosure. Fig. 1A is a perspective view, Fig. 1B is a side view, and Fig. 2 is a cross-sectional view. The wire harness 1 according to this embodiment has a flat electric wire 2 as an electric wire portion, a pair of exterior materials 3, 3, and a tape 4 as a fixing member.

[0022] The electric wire portion included in the wire harness 1 includes one or more insulated electric wires each having a conductor 20 and an insulating coating 22 covering the outer periphery of the conductor 20, and the electric wire portion as a whole has a flat cross section perpendicular to the axial direction. In this embodiment, the electric wire portion is composed of a single insulated electric wire, and the insulated electric wire is configured as a flat electric wire 2 in which the insulating coating 22 is formed on the outer periphery of the conductor 20 having a flat cross section, and the entire cross section also has a flat cross section. Here, the flat shape refers to a shape in which the dimension in the width direction of the cross section is larger than the dimension in the height direction perpendicular to the width direction. In the following description and each drawing, the width direction of the cross section of the flat electric wire 2 is defined as the x direction, the height direction (vertical direction) is defined as the z direction, and the axial direction (longitudinal direction) perpendicular to the x direction and z direction is defined as the y direction.

[0023] Each of the pair of exterior covering materials 3, 3 is configured as a sheet-like (including plate-like) member. The pair of exterior covering materials 3, 3 are arranged in contact with both height-wise surfaces (upper and lower surfaces 2a, 2a) of the flat electric wire 2 of the electric wire portion. The exterior covering materials 3, 3 are in contact with the upper and lower surfaces 2a, 2a of the electric wire portion over the entire width direction. Preferably, as in the illustrated embodiment, the width dimension of the exterior covering materials 3, 3 is larger than that of the flat electric wire 2 of the electric wire portion, and the exterior covering materials 3, 3 extend outward in the width direction beyond the flat electric wire 2.

[0024] The constituent materials and structure of the exterior coverings 3,3 will be described in detail later, but they are made of a material that has a higher tensile modulus than the insulating coating 22 that constitutes the flat electric wire 2 of the electric wire portion, and have higher bending flexibility in the height direction and preferably also in the width direction than the electric wire portion (here, the flat electric wire 2). The exterior coverings 3,3 are not limited to specific materials or structures as long as they satisfy these material properties, but a suitable configuration for the exterior coverings 3,3 can be exemplified by a bellows sheet made of a resin material. The bellows sheet is configured as a sheet material with a bellows structure with bellows-like irregularities along the axial direction of the electric wire.

[0025] The fixing member, which is made of tape 4, fixes the pair of outer coverings 3, 3 to each other at a plurality of fixing points provided at intervals along the axial direction of the flat electric wire 2. The tape 4 serves to stably maintain the state in which the outer coverings 3, 3 sandwich the flat electric wire 2 from above and below. In the illustrated embodiment, a long, continuous tape 4 is spirally wound around the outer periphery of the assembly of the pair of outer coverings 3, 3 and the flat electric wire 2, with gaps left between turns (between pitches). The positions where the tape 4 is arranged on each turn are fixing points. Because the tape 4 is wound with gaps, in the areas where the tape 4 is not arranged, the side portions 2b, 2b (both sides in the width direction) of the flat electric wire 2 are not covered by either the outer coverings 3, 3 or the tape 4 and are directly exposed to the external environment. In the illustrated embodiment, the widthwise dimension of the outer packaging materials 3,3 is greater than the width of the flat electric wire 2, and the tape 4 is not in contact with the side surface portions 2b,2b of the flat electric wire 2. However, at the longitudinal end portions of the outer packaging materials 3,3, it is preferable to directly fix the outer packaging materials 3,3 and the flat electric wire 2 with the tape 4 so that the flat electric wire 2 does not shift in the axial direction relative to the outer packaging materials 3,3 (omitted in Figs. 1A and 1B; see Fig. 7), and at the fixed portions, the tape 4 may be in direct contact with the surface of the electric wire, including the side surface portions 2b,2b. Each component of the wire harness 1 will be described in detail below.

[0026] <Flat electric wire> The conductor 20 constituting the flat electric wire 2 as the electric wire portion may have a single-wire structure made of a continuous metal material such as a metal foil or a metal plate, or may be configured as a twisted wire in which multiple wires 21 are twisted together. However, from the viewpoint of increasing the flexibility of the flat electric wire 2 in both the height direction and the width direction, it is preferable to configure it as a twisted wire. The cross section of the conductor 20 may have any specific shape as long as it is flat. In this embodiment, the cross section of the conductor 20 is approximated to a rectangle. Examples of flat shapes other than a rectangle include an ellipse, an oval, an oval (a shape with semicircles on both ends of a rectangle), a parallelogram, and a trapezoid. When the conductor 20 is configured as a twisted wire, the conductor 20 can be formed, for example, by rolling a raw twisted wire in which multiple wires 21 are twisted together into a substantially circular cross section. The flat electric wire 2 is obtained by covering the entire circumference of the conductor 20 with a flat cross section and forming an insulating coating 22.

[0027] The flat electric wire 2 has a conductor 20 with a flat cross section, and therefore occupies a smaller dimension in the height direction than a conventional round electric wire having a conductor with a substantially circular cross section but the same conductor cross-sectional area, which contributes to space saving. In addition, since the conductor 20 has a flat shape and is smaller in the height direction, flat wire 2 exhibits high flexibility, especially in the height direction.

[0028] The material constituting the conductor 20 is not particularly limited, and various metal materials can be used. Typical metal materials constituting the conductor 20 include copper and copper alloys, and aluminum and aluminum alloys. In particular, aluminum and aluminum alloys have lower electrical conductivity than copper and copper alloys, so the cross-sectional area of ​​the conductor tends to be large in order to ensure the required electrical conductivity. Therefore, flattening the conductor 20 increases the effect of saving space and improving bending flexibility in the height direction. From this perspective, it is preferable to make the conductor 20 from aluminum or an aluminum alloy. From the same perspective, it is also preferable to make the conductor 20 from a material with a cross-sectional area of ​​10 mm or less. 2 Above, even 50mm 2 Over 100mm2 Although there is no particular upper limit to the conductor cross-sectional area, it is preferable to set it to, for example, 200 mm 2 It is best to keep it below this.

[0029] The material that constitutes the insulating coating 22 is not particularly limited as long as it is an insulating material, but it is preferable to use an organic polymer as the base material. In particular, polyvinyl chloride, polyolefins such as polyethylene, fluororesins, and silicone resins are suitable because of their high flexibility. Conductor area 10 mm 2 When the insulating coating 22 is made of these materials, the tensile modulus of elasticity is approximately 200 MPa or less. In addition to the organic polymer, the insulating coating 22 may contain various additives such as a flame retardant. The thickness of the insulating coating 22 is not particularly limited, but can be in the range of 1 mm or more and 2 mm or less.

[0030] <Exterior materials> As described above, the exterior covering materials 3, 3 are made of a material having a higher tensile modulus than the insulating coating 22 constituting the flat electric wire 2 of the electric wire portion, and have higher bending flexibility in the height direction than the flat electric wire 2 (the entire electric wire portion). Furthermore, it is preferable that the exterior covering materials 3, 3 also have higher flexibility in the width direction than the flat electric wire 2.

[0031] The constituent material of the outer covering 3, 3 has a higher tensile modulus than the constituent material of the insulating coating 22, so that the outer covering 3, 3 can fully function as a protective material that protects the flat electric wires 2 from serious damage caused by external physical stimuli. In other words, even if the wire harness 1 comes into contact with or collides with an external object, the outer covering 3, 3 absorbs the impact and protects the flat electric wires 2 from a serious impact. The specific tensile modulus of the constituent material of the outer covering 3, 3 is not particularly specified, but a range of 1000 MPa or more and 2000 MPa or less can be exemplified. A tensile modulus of 1500 MPa or more is particularly preferred. The tensile modulus of the resin material can be evaluated by a tensile test in accordance with JIS K 7161.

[0032] In order to enhance the protective performance of the exterior covering 3,3, the material of the exterior covering 3,3 has a higher tensile modulus than the material of the insulating coating 22. 22 It is preferable that the tensile modulus and hardness of the material have a higher hardness than the constituent materials of the material 1. In this specification, the tensile modulus and hardness of the material refer to the physical properties as the characteristics of the material type itself, and do not include the effect of the shape, even if the material has a shape other than a simple flat shape, such as the bellows structure of the exterior materials 3, 3.

[0033] The high tensile modulus of elasticity of the outer covering materials 3, 3 ensures protective performance. Meanwhile, the higher bending flexibility of each outer covering material 3, at least in the height direction, than that of the flat electric wires 2 ensures high bending flexibility for the entire wire harness 1 without significantly impairing the flexibility of the flat electric wires 2. In this specification, the bending flexibility of a member refers to the flexibility obtained when bending the member, including the effects of the shape of the member, such as the bellows structure of the outer covering materials 3, 3. The outer covering materials 3, 3 made of a bellows sheet exhibit high flexibility in the width direction and thickness direction (height direction). The outer covering materials 3, 3 are formed from a material with a bellows structure that meanders up and down along the longitudinal direction. Because the outer covering materials 3, 3 are capable of stretching to a certain extent, when the outer covering materials 3, 3 are bent in both the width direction and the thickness direction, the spacing between adjacent peaks widens on the outside of the bend and narrows on the inside of the bend, allowing them to flexibly follow the bend. The bending flexibility of the exterior covering material 3, 3 and the flat electric wire 2 can be compared by a three-point bending test or the like, but a simpler method is to compare the amount of sagging when held horizontally (see Figure 6). When comparing one sheet of exterior covering material 3 cut to the same length with one flat electric wire 2, it is desirable that the amount of sagging is greater for the exterior covering material 3 at least when the height direction is oriented in the direction of gravity. Also, when the width direction is oriented in the direction of gravity, the amount of sagging is greater for the exterior covering material 3 and the flat electric wire 2. Flat wire 2 About the same (roughly Sheathing material 3 and flat wire 2 It is recommended that the percentage is 90% or higher.

[0034] While the materials constituting the outer jacket 3,3 are not particularly limited, resin materials such as polypropylene, polyamide, and polyester are suitable because of their high tensile modulus and excellent protective performance. The tensile modulus of the outer jacket 3,3 made of these materials tends to fall within the aforementioned range of 1,000 MPa to 2,000 MPa. The outer jacket 3,3 may contain various additives, such as flame retardants, in addition to organic polymers. The thickness (plate thickness) of the sheet material constituting the outer jacket 3,3 is not particularly limited, but examples include a range of 0.2 mm to 1 mm. Furthermore, examples include a range of 1 mm to 3 mm for the height of the bellows structure (the height between the valleys and peaks along the height direction z), and a range of 2 mm to 5 mm for the pitch of the bellows structure (the distance between the peaks along the longitudinal direction y). Examples of suitable outer jackets 3,3 of this embodiment include sheets with longitudinally aligned irregularities made of the same material as the wall of a conventional corrugated tube, such as those shown in Figures 3A and 3B.

[0035] <Tape> The type of tape 4 used as the fixing member is not particularly limited as long as it is made of a long sheet material. However, from the viewpoint of stably maintaining the structure in which the exterior materials 3, 3 are fixed, it is preferable to use tape 4 having an adhesive layer (including a pressure-sensitive adhesive layer) on the surface that comes into contact with the exterior materials 3, 3.

[0036] Preferably, tape 4 has higher flexibility in each direction than sheath materials 3,3 so as not to impede the flexibility of sheath materials 3,3. Furthermore, the tensile modulus of the material of tape 4 is preferably lower than that of the material of sheath materials 3,3, and even lower than that of the material of insulating coating 22. A suitable example of the material of tape 4 is a material having an adhesive layer on one side of a base material made of polyvinyl chloride or the like. The tensile modulus of commercially available tapes made of these materials is generally 50 MPa or less.

[0037] <Protection and flexibility in wire harnesses> In the wire harness 1 according to this embodiment, the exterior covering materials 3, 3 are arranged on both surfaces 2a, 2a in the height direction of the flat electric wire 2. Therefore, the exterior covering materials 3, 3 provide protection to the flat electric wire 2, and the flat electric wire 2 is less susceptible to the effects of physical stimuli such as contact or collision applied from the outside. The exterior covering materials 3, 3 have a higher tensile modulus than the insulating coating 22 of the flat electric wire 2, thereby achieving high protective performance.

[0038] Of the surfaces of the flat electric wire 2 constituting the wire harness 1, the upper and lower faces 2a, 2a in the height direction constitute the largest area. By providing the exterior materials 3, 3 to cover these faces 2a, 2a, a high protective effect can be obtained for the flat electric wire 2. In particular, when the exterior materials 3, 3 have a width greater than that of the flat electric wire 2 and cover the upper and lower faces 2a, 2a in the height direction of the flat electric wire 2 over the entire width direction, the protective effect is high. Although the side surfaces 2b, 2b (faces on both sides in the width direction) of the flat electric wire 2 are not covered by the exterior material, the area of ​​the side surfaces 2b, 2b is reduced due to the flat shape of the flat electric wire 2, and therefore the reduction in the protective performance of the flat electric wire 2 as a whole caused by the side surfaces 2b, 2b not being covered by the exterior material is limited. Furthermore, when the outer casing material 3,3 has a width greater than that of the flat electric wire 2 and extends outward in the width direction than the flat electric wire 2, the extending portions of the outer casing material 3,3 also provide a certain degree of protection to the side portions 2b,2b of the flat electric wire 2 against contact with external objects.

[0039] In the wire harness 1 according to this embodiment, while the exterior covering materials 3, 3 provide high protection performance, the exterior covering materials 3, 3 are arranged only on the upper and lower sides in the height direction of the surface of the flat electric wire 2, and not on both sides in the width direction, so that the wire harness 1 as a whole exhibits high flexibility. As described above, each of the pair of exterior covering materials 3, 3 has higher flexibility than the flat electric wire 2 at least in the height direction, and the exterior covering materials 3, 3 are arranged to sandwich the flat electric wire 2 from above and below in the height direction, so that the wire harness 1 as a whole exhibits high flexibility when bent in the height direction (flat direction) and also when bent in the width direction (edge ​​direction).

[0040] Here, in the case of a wire harness 9 in which flat electric wires 2 are inserted into a flat corrugated tube 8, as shown in perspective and side views in Figures 3A and 3B and in a cross section in Figure 4, the constituent material of the corrugated tube 8 surrounds the entire circumference of the flat electric wires 2, and therefore high flexibility cannot be obtained in bending in the width direction (x direction) and height direction (z direction). 81 are integrally connected by side wall surfaces 82, 82 arranged along the up-down direction, and the corrugated tube 8 has a large moment of inertia. In particular, when bending the wire harness 9 in the width direction, the side wall surfaces 82, 82 of the corrugated tube 8 need to be compressed on the inside of the bend and deformed in-plane in a direction that expands on the outside of the bend, which requires a large force even though the wire harness 9 has a corrugated structure.

[0041] In contrast, in the wire harness 1 according to the embodiment of the present disclosure, the pair of upper and lower exterior materials 3, 3 are not integrally joined but are configured as separate bodies and are arranged to sandwich the flat electric wire 2, so that the moment of inertia of the two exterior materials 3, 3 combined is smaller than that of the corrugated tube 8. Therefore, the wire harness 1 can achieve high flexibility in both the width direction and the height direction.

[0042] In the wire harness 1 according to the present embodiment, the tape 4 as a fixing member fixes the upper and lower exterior materials 3, 3 to each other and plays a role in stably holding the flat electric wire 2 sandwiched between the exterior materials 3, 3, and the arrangement of this tape 4 also contributes to increasing the flexibility of the wire harness 1. If the tape 4 were wrapped tightly along the axial direction of the flat electric wire 2, the flat electric wire 2 would be held more stably, but the flexibility of the wire harness as a whole would be reduced, and the flexibility of the flat electric wire 2 and the exterior materials 3, 3 would not be easily expressed as the flexibility of the entire wire harness. In contrast, the tape 4 is wrapped with gaps and fixes the upper and lower exterior materials 3, 3 only at fixing points provided at intervals along the axial direction of the flat electric wire 2, so that the wire harness 1 as a whole maintains high flexibility.

[0043] The flexibility of the wire harness 1 can be controlled to some extent by the arrangement of the tape 4. The smaller the gap between the turns, the smaller the pitch at which the tape 4 is wound, and the tighter the tape 4 is wound, and the stronger the pressure contact between the upper and lower exterior materials 3, 3 and fixed to the flat electric wire 2, the more stably the flat electric wire 2 is sandwiched between the pair of exterior materials 3, 3, and the higher the protection performance for the flat electric wire 2 becomes, but the flexibility of the wire harness 1 decreases. On the other hand, the larger the gap between the turns, the larger the pitch at which the tape 4 is wound, and the looser the tape 4 is wound, and the less strongly the upper and lower exterior materials 3, 3 are pressed against the flat electric wire 2, the lower the protection performance of the exterior materials 3, 3 may become, but the greater the flexibility of the wire harness 1 as a whole can be. This is because the flat electric wire 2 is allowed to move relative to one another to some extent in the space between the pair of exterior materials 3, 3, allowing the flat electric wire 2 to bend flexibly.

[0044] For the wire harness 1, the size of the gap between turns of the tape 4 when wrapping and the degree of tightness of the wrapping can be selected taking into consideration the required protective performance and flexibility. As a suitable form that can achieve both sufficient protective performance and flexibility, the size of the gap between turns of the tape 4 can be set such that the ratio (b / a) of the area (b) of the region covered by the tape 4 to the total area (a) of the outer periphery of the wire harness 1 is 5% or more and 95% or less. In addition, as for the tightness of the wrapping of the tape 4, an example can be set such that the tape 4 is wrapped with a force such that the contact pressure from the tape 4 causes elastic deformation in the thickness direction of the jacket materials 3, 3 (the portions where the tape 4 is wrapped are compressed), while the insulating coating 22 is not deformed.

[0045] The flexibility of the entire wire harness 1 can be simply evaluated by the amount of sagging due to its own weight. As shown in Figure 6, one end of the test specimen S (wire harness) is held horizontally by a jig T or the like, and the distance d that the other end sags from the horizontal position due to its own weight is taken as the amount of sagging. The flexibility in the width direction and height direction can be evaluated by the amount of sagging when the width and height directions of the flat shape of the flat electric wire 2 are placed in the direction of gravity. The greater the amount of sagging, the higher the flexibility can be evaluated.

[0046] The flexibility of the wire harness 1 can be evaluated by comparing the sagging amount of the wire harness 1 with the sagging amount similarly evaluated for only the flat electric wires 2 cut to the same length. For example, it is preferable that the sagging amount of the wire harness 1 is 60% or more of the sagging amount of only the flat electric wires 2 in both the width direction and the height direction. It is even more preferable that it is 70% or more. In this case, it can be said that a sufficiently high flexibility is ensured for the wire harness 1 as a whole. The arrangement of the tapes 4 can be set so that this level of sagging amount can be ensured in the wire harness 1.

[0047] On the other hand, when winding the tape 4, narrowing the gaps between the turns to some extent and winding the tape 4 tightly can also have the effect of maintaining the wire harness 1 in a predetermined bent shape. For example, the flat electric wires 2 and the outer jacketing materials 3, 3 are bent into a predetermined bent shape required by the wiring route, etc., and then the tape 4 is wound around the outer periphery of the assembly of the flat electric wires 2 and the outer jacketing materials 3, 3, thereby maintaining the bent shape. If the wire harness 1 is routed to a predetermined location, such as inside an automobile, while maintaining the bent shape in this manner, there is no need to apply a large bend to the wire harness 1 again during routing, thereby improving workability. In this configuration, the upper and lower jacketing materials 3, 3 are configured as separate bodies and are fixed to each other by the tape 4, so the wire harness 1 exhibits higher flexibility than when a corrugated tube 8 is used.

[0048] The tape 4 may contact the surface of the flat electric wire 2 at the side portions 2b, 2b of the flat electric wire 2. However, from the viewpoint of ensuring the freedom of relative movement of the flat electric wire 2 in the space sandwiched between the pair of exterior materials 3, 3 and increasing the flexibility of the wire harness 1, it is preferable that the tape 4 does not contact the flat electric wire 2 except for the longitudinal end portions of the exterior materials 3, 3. When the width of the exterior materials 3, 3 is configured to be larger than the width of the flat electric wire 2, contact is unlikely to occur between the tape 4 wrapped around the outer periphery of the exterior materials 3, 3 and the flat electric wire 2.

[0049] <Other forms> In the embodiment described above, the electric wire portion is configured by one flat electric wire 2, the exterior materials 3, 3 are configured by a pair of bellows sheets, and the fixing member is configured by tape 4, but the members that configure the wire harness of the present disclosure are not limited to these. Major modified embodiments will be briefly described below.

[0050] As long as the electric wire portion has a flat cross-sectional shape as a whole, it may include only one insulated electric wire configured as the flat electric wire 2 as described above, or may include a collection of multiple insulated electric wires. When multiple insulated electric wires are included, the insulated electric wires may be flat electric wires or conventional round electric wires with a generally circular cross-section. In either case, it is sufficient that the multiple insulated electric wires are arranged in the width direction, and the overall cross-sectional shape of the collection of the multiple insulated electric wires is a flat shape that is elongated in the width direction. As long as the cross-section is a flat shape that is elongated in the width direction, the insulated electric wires may be arranged in multiple rows in the height direction as well as the width direction.

[0051] As explained above, the use of tape 4 is the most advantageous fixing member from the viewpoint of high flexibility, etc. However, the fixing member is not limited to tape, as long as it can fix a pair of exterior materials 3, 3 to each other at multiple fixing points provided at intervals along the axial direction of the electric wire portion. For example, the upper and lower exterior materials 3, 3 may be fixed to each other at an interval by bonding with an adhesive or by fusion bonding. Alternatively, the upper and lower exterior materials 3, 3 may be fixed to each other by placing fixing devices configured in the shape of pins or the like at an interval.

[0052] In yet another embodiment, the fixing member can be formed using the same material as the exterior material. In this case, the upper and lower exterior materials and the fixing member may be integrally formed. An example of such an embodiment in which the fixing member is integrally formed with the exterior material is illustrated in FIG. 5 . The integral exterior material 5 includes a pair of upper and lower exterior materials 51 and a fixing member 52 connecting the exterior materials 51. Like the upper and lower exterior materials 51, the fixing member 52 is also formed of a sheet material having a bellows structure. Similarly to the exterior materials 51, the fixing member 52 also has the concave and convex portions of the bellows structure arranged along the longitudinal direction (y direction). In this manner, the integral exterior material 5 in which the exterior materials 51 and the fixing member 52 are integrated can be easily formed using a flat corrugated tube 8 similar to that used in the wire harness 9 of FIGS. 3A and 3B . Specifically, a plurality of lightening portions W serving as window-like through-holes may be formed in the side wall surfaces 82 of the corrugated tube 8. The upper and lower surfaces 81, 81 of the corrugated tube 8 function as exterior materials 51, 51, and the side wall surfaces 82, 82 other than the portions where the lightening portions W are formed function as fixing members 52. [Example]

[0053] Examples are shown below. However, the present invention is not limited to these examples. Here, the flexibility in bending in the height direction and width direction was compared between a case where a bellows sheet was used as an exterior material and a case where a corrugated tube was used.

[0054] (Sample preparation) A flat wire was prepared as the electric wire part. A round wire made of stranded aluminum alloy wire was rolled into a flat shape using a roller to produce a flat conductor, and an insulating coating was formed on the outer periphery of the conductor by extrusion molding. The wire used had an outer diameter of 0.3 mm and a conductor cross-sectional area of ​​50 mm. 2 The insulating coating was made of polyvinyl chloride and was 1 mm thick. The tensile modulus of the insulating coating material was 20 MPa. The dimensions of the flat wire after the insulating coating was formed were 19 mm wide and 8 mm high.

[0055] Two types of exterior materials were prepared: a bellows sheet and a corrugated tube. Both exterior materials were made of polyamide material with a thickness of 1 mm, with unevenness arranged along the longitudinal direction. The height of the corrugated structure (bellows structure) (the height between the valleys and peaks along the height direction) was 3 mm, and the width of the corrugated structure (the distance between the peaks along the longitudinal direction) was 4 mm. The tensile modulus of the material constituting the exterior material was 1 x 10 3 The bellows sheet was formed as a long sheet with a width of 30 mm. The corrugated tube was formed into a tubular shape with a flat cross section, with outer dimensions of 40 mm in width and 18 mm in height.

[0056] Harness 1 and Harness 2 were fabricated as wire harnesses using these flat electric wires and outer covering materials. In Harness 1, a bellows sheet was used as the outer covering material. The outer covering materials were brought into contact with both sides of a single flat electric wire in the height direction, and tape was wrapped around the outer circumference of the assembly to secure the outer covering materials together, thereby fabricating a wire harness with the structure shown in Figures 1A, 1B, and 2. The tape used was a polyvinyl chloride sheet with an adhesive layer on one side, and was wrapped so that the gap between turns (the distance along the axial direction of the flat electric wire) was 30 mm.

[0057] On the other hand, for harness 2, a flat electric wire was inserted into a corrugated tube to produce a wire harness with the structure shown in Figures 3A, 3B, and 4. In both harnesses 1 and 2, the flat electric wire was 600 mm long in the axial direction, the length of the outer jacket was 500 mm, and the flat electric wire protruded 50 mm from both ends of the outer jacket in the axial direction. In addition, the outer jacket was fixed to the flat electric wire with tape at both ends of the outer jacket. In harness 1, the tape did not come into contact with the flat electric wire except at the fixed points at the ends.

[0058] (Test Method) The amount of sagging due to dead weight was evaluated for the above-mentioned harnesses 1 and 2, as well as for the flat wires, bellows sheets, and corrugated tubes that comprise these wire harnesses. For the evaluation, as shown in Figure 6, one end of each specimen S was held horizontally, and the distance d that the other end sagged from the horizontal position due to its own weight was measured as the amount of sagging, and the measurements were compared between specimens. The test was conducted in two ways: with the height direction (thickness direction; flat direction) facing the direction of gravity, and with the width direction (edge ​​direction) facing the direction of gravity. For harnesses 1 and 2, specimens with the dimensions described above for sample preparation were used, and for the bellows sheets and corrugated tubes, specimens cut to 500 mm were used separately. For the flat wires, specimens cut to 500 mm were used for comparison with the bellows sheets and corrugated tubes, and specimens cut to 600 mm were used for comparison with harnesses 1 and 2. For harnesses 1 and 2, as shown for harness 2 (H2) in Figure 7, exterior materials The amount of droop was measured in the area where the

[0059] (Test results) Figure 7 shows a photograph of the test being conducted to measure the amount of sagging, comparing Harness 1 and Harness 2. Here, the height direction of the flat wires is oriented in the direction of gravity, and bending flexibility in the height direction is compared. As can be seen in the photograph, Harness 1 (H1), which uses a bellows sheet, has a significantly greater amount of sagging than Harness 2 (H2), which uses a corrugated tube. In other words, it can be seen that Harness 1 has significantly greater flexibility.

[0060] 8A and 8B show the results of evaluating the amount of sagging for harnesses 1 and 2, flat electric wires of two lengths (abbreviated as electric wires in the figures), and two types of exterior materials. Fig. 8A shows the amount of sagging in the height direction, and Fig. 8B shows the amount of sagging in the width direction.

[0061] In each of Figures 8A and 8B, when comparing the amount of sagging of a 500 mm flat electric wire and a bellows sheet, the bellows sheet has a larger amount of sagging in the height direction. In the width direction, the amount of sagging of both is about the same. In other words, it can be confirmed that the bellows sheet has clearly higher bending flexibility than the flat electric wire, at least in the height direction. Considering that the flat electric wire has a larger mass than the bellows sheet, it can be said that the difference in bending flexibility excluding the influence of its own weight is greater than the difference in the amount of sagging. In the width direction, the amount of sagging of the bellows sheet and the flat electric wire is also difference Considering that the mass of the flat wire is greater than that of the bellows sheet, it can be said that the bellows sheet has higher flexibility.

[0062] Next, comparing the amount of sagging of harness 1 using a bellows sheet and harness 2 using a corrugated tube in each of Figures 8A and 8B, harness 1 has a greater amount of sagging than harness 2 in both the height and width directions. In other words, harness 1 exhibits higher bending flexibility in both the height and width directions. Harness 1 has a mass of 160g, while harness 2 has a mass of 175g, making harness 2 the larger mass. In other words, even excluding the effect of their own weights, harness 1 can be said to have higher bending flexibility in the height and width directions than harness 2.

[0063] When comparing the amount of sagging of Harness 1, a wiring harness made using a bellows sheet, with that of a single flat electric wire, the amount of sagging of Harness 1 is approximately 90% in the height direction and approximately 70% in the width direction of the amount of sagging of a flat electric wire (600 mm). Harness 1 has a greater mass than the flat electric wire due to the amount of the bellows sheet and tape, so the amount of sagging cannot be simply converted into the level of bending flexibility. However, if the amount of sagging of the wiring harness is roughly 70% or more of the amount of sagging of the flat electric wire, it can be said that the bending flexibility of the flat electric wire is maintained at a sufficiently high level, even when made into a wiring harness using a bellows sheet and tape.

[0064] From the above test results, it was confirmed that by using a bellows sheet, which has higher bending flexibility than a flat electric wire, as the outer casing material, and sandwiching the top and bottom surfaces of the flat electric wire in the height direction with this outer casing material and securing it with tape to form a wire harness, it is possible to obtain higher flexibility in bending in both the height direction and width direction compared to when a corrugated tube is used.

[0065] Although the embodiments of the present disclosure have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0066] 1 Wire harness 2 Flat wire (wire section) 2a Upper and lower surfaces 2b Side part 20 Conductors 21 Wire 22 Insulation coating 3. Exterior material (accordion sheet) 4 Tape (fixing material) 5 Integrated exterior material 51 Exterior materials 52 Fixing member 8 Corrugated Tube 81 Upper and lower surfaces 82 Side wall 9 Conventional wire harness H1 Harness 1 H2 Harness 2 S test specimen T jig W Hollowed-out section x width direction y-axis direction z Height direction

Claims

1. an electric wire portion including one or more insulated electric wires each having a conductor and an insulating coating covering the outer periphery of the conductor, the electric wire portion having a flat shape in a cross section perpendicular to the axial direction in which the dimension in the width direction is greater than the dimension in the height direction; a pair of exterior materials arranged in contact with both sides of the electric wire portion in the height direction; a fixing member that fixes the pair of exterior materials to each other with the electric wire portion sandwiched therebetween, The electric wire portion includes one insulated electric wire configured as a flat electric wire or a collection of a plurality of the insulated electric wires, the sheath material is made of a material having a higher tensile modulus than the insulating coating and has higher bending flexibility in the height direction than the electric wire portion, The fixing member fixes the pair of exterior materials to each other at a plurality of fixing points provided at intervals along the axial direction of the electric wire portion.

2. The wire harness according to claim 1 , wherein the exterior material has higher bending flexibility in the width direction than the electric wire portion.

3. 3. The wire harness according to claim 1, wherein each of the pair of exterior materials is configured as a sheet material having a bellows structure with projections and depressions along an axial direction of the electric wire portion.

4. The wire harness according to claim 1 , wherein the fixing member is made of a tape having higher flexibility than the exterior material.

5. 5. The wire harness according to claim 4, wherein the fixing member is wound around an outer periphery of the assembly of the pair of exterior materials and the electric wire portion in a spiral shape with gaps provided between turns along an axial direction of the electric wire portion.

6. 6. The wire harness according to claim 1, wherein the fixing member is not in contact with the electric wire portion at a position other than an end of the exterior material along an axial direction of the electric wire portion.

7. The wire harness according to claim 1 , wherein each of the pair of exterior materials has a dimension in the width direction larger than that of the electric wire portion.

8. 8. The wire harness according to claim 1, wherein the insulated wire is a flat wire having, as the conductor, a flat conductor formed by twisting together a plurality of element wires and shaping the twisted wire into a flat shape.

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