Wire harness

Abstract

To provide a wire harness in which wire groups including a plurality of communication wires each subjected to noise shield are fixed to a common base material while securing space saving properties with a simple structure.SOLUTION: A wire harness 1 includes: a wire group 2 including a plurality of communication wires 20; a conductor wire 31; an insulation coating 32 for coating the conductor wire 31; and a sheet-like shield material 5 including a ground wire 3 connectable to a ground potential, a base material 4 and a metal layer 51. The respective wires constituting the wire group 2 are fixed to the base material 4. The shield material 5 covers the surface of the wire group 2 and is fixed to the base material 4. The conductor wire 31 of the ground wire 3 is electrically connected to the metal layer 51 of the shield material 5.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] In order to assemble a plurality of electric wires while maintaining a space-saving effect in the height direction, a wire harness may be constructed by fixing electric wires to the surface of a sheet material made of a resin sheet or a nonwoven fabric. For example, Patent Document 1 discloses a wire harness in which electric wires are fixed to a sheet material by sewing or welding, and the wire harness is arranged along a plate-like member included in an interior member of a vehicle. Of various electric wires, it is also conceivable to fix communication electric wires to a sheet material and incorporate them into the wire harness. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-196174 A Summary of the Invention [Problem to be solved by the invention]

[0004] When a communication electric wire is included in a wire harness in which a plurality of electric wires are fixed to a sheet material as described in Patent Document 1, it is desirable to provide noise shielding for the communication electric wire. In particular, when the communication electric wire is configured as a parallel electric wire in which a pair of insulated electric wires are arranged side by side, unlike a twisted electric wire in which a pair of insulated electric wires are twisted together, the influence of common noise tends to be large, and noise shielding becomes important.

[0005] When a wire harness contains multiple communication electric wires, if noise shielding is applied to each individual communication electric wire, the labor and cost required for noise shielding will be large. Also, even if space saving of the wire harness is attempted by devising the layout of the electric wires, such as fixing them to a common sheet material, if noise shielding is applied to multiple communication electric wires, the shielding material will take up a large overall volume, and the effect of space saving may not be fully utilized.

[0006] Therefore, an object of the present invention is to provide a wire harness in which a group of electric wires including a plurality of communication electric wires is fixed to a common substrate, and which has a simple structure, ensures space saving, and provides noise shielding for each communication electric wire. [Means for solving the problem]

[0007] The wire harness of the present disclosure includes an electric wire group including a plurality of communication electric wires, a conductor wire, a ground wire including an insulating coating covering the conductor wire and connectable to a ground potential, a substrate, and a sheet-like shielding material including a metal layer, wherein each electric wire constituting the electric wire group is fixed to the substrate, the shielding material covers a surface of the electric wire group and is fixed to the substrate, and the conductor wire of the ground wire is electrically connected to the metal layer of the shielding material. Effect of the Invention

[0008] The wire harness according to the present disclosure is a wire harness in which a group of electric wires including a plurality of communication electric wires is fixed to a common substrate, and is a wire harness that has a simple structure, is space-saving, and provides noise shielding for each communication electric wire. [Brief description of the drawings]

[0009] [Figure 1] 1 is a plan view showing a wire harness according to an embodiment of the present disclosure, in which components are gradually removed from an end portion. [Diagram 2]FIG. 2 is a cross-sectional view showing a structure in the vicinity of an end portion of the wire harness. [Diagram 3] FIG. 3 is a plan view showing a schematic connection state of the wire harness. [Figure 4] FIG. 4 is a cross-sectional view showing the structure of a shielding material constituting the above-mentioned wire harness. [Diagram 5] 5A and 5B are diagrams showing a wire harness according to a modified embodiment in which the shielding material is divided into a plurality of pieces, Fig. 5A is a plan view showing the wire harness and its connected state, and Fig. 5B is a cross-sectional view showing the joint between the divided shielding materials. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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 an embodiment of the present disclosure has the following configuration.

[0011] [1] A wire harness according to the present disclosure includes an electric wire group including a plurality of communication electric wires, a conductor wire, a ground wire including an insulating coating covering the conductor wire and connectable to a ground potential, a substrate, and a sheet-like shielding material including a metal layer, wherein each electric wire constituting the electric wire group is fixed to the substrate, the shielding material covers a surface of the electric wire group and is fixed to the substrate, and the conductor wire of the ground wire is electrically connected to the metal layer of the shielding material.

[0012] In the above wire harness, a group of electric wires including a plurality of communication electric wires is fixed to a substrate and covered with a shielding material. This shielding material plays a role of noise shielding for each communication electric wire included in the group of electric wires. A current generated in the metal layer of the shielding material by noise shielding is passed to a ground potential by a ground wire. By covering the group of electric wires with a common shielding material and fixing the shielding material to the substrate, noise shielding for the plurality of communication electric wires included in the group of electric wires can be performed collectively, so that noise shielding can be performed for each communication electric wire with a simple structure. In addition, the increase in the dimensions of the wire harness in the height direction and width direction due to noise shielding is only the dimension required to cover the group of electric wires with a sheet-like shielding material, so that high space saving is ensured.

[0013] [2] In the above aspect [1], the communication electric wire may be configured as a parallel electric wire in which a pair of insulated electric wires are arranged with their axes aligned. Parallel electric wires can be used to configure this type of wire harness in which a group of electric wires is fixed to a substrate, because the electric wire height can be kept small compared to a twisted electric wire in which a pair of insulated electric wires are twisted together, the parallel electric wires can be easily fixed to a substrate, and the cost required for twisting can be omitted. On the other hand, parallel electric wires are more likely to generate common mode noise compared to twisted electric wires, but the common mode noise can be effectively reduced by covering them with a shielding material.

[0014] [3] In the above aspect [1] or [2], the shielding material may further have a resin film, and the metal layer may be provided on a surface of the resin film. By having the resin film in the shielding material, the mechanical strength and handling properties of the shielding material are improved.

[0015] [4] In the above aspect [3], the shielding material may further have an adhesive layer made of an adhesive on the surface of the resin film opposite to the metal layer, and the shielding material may cover the group of electric wires with the surface on which the adhesive layer is provided facing inward, and may be fixed to the base material and the group of electric wires by the adhesive layer. In this case, the adhesive layer can be used to easily fix the shielding material to the base material without the need to use a fixing member or apply a separate adhesive. In addition, the shielding material can be fixed in close contact with the group of electric wires, thereby enhancing the noise shielding effect for the group of electric wires.

[0016] [5] In any one of the above aspects [1] to [4], the ground wire may be provided only in a partial region along the axial direction of the electric wire group. As long as the ground wire is electrically connected to the metal layer of the shielding material at at least one point, it can play a role of flowing the current generated during noise shielding to the ground potential. Therefore, even if the wire harness has a long electric wire group or shielding material, it is sufficient to provide the ground wire only in a partial region along the axial direction of the electric wire group. By configuring the ground wire to be short, the space-saving and lightweight properties of the wire harness can be improved and material costs can be kept low.

[0017] [6] In the above aspect [5], the ground wire may be provided in a region including at least one end of the shielding material along the axial direction of the wire group, thereby making it possible to shorten the ground wire and to provide high convenience in attaching the ground wire to the shielding material and connecting it to a ground potential.

[0018] [7] In any one of the above aspects [1] to [6], the ground wire may be disposed outside the space in which the shielding material covers the group of electric wires. This simplifies the structure of the wire harness, and also saves space. It also makes it easier to attach the ground wire to the shielding material.

[0019] [8] In any one of the above aspects [1] to [7], the electrical connection between the conductor wire of the ground line and the metal layer of the shielding material may be formed by piercing a piercing terminal to which the ground wire is connected into the metal layer. This makes it possible to easily form an electrical connection having low contact resistance between the conductor wire of the ground line and the metal layer of the shielding material and to maintain it more stably.

[0020] [9] In any one of the above aspects [1] to [8], the thickness of the metal layer is preferably 10 μm or more, so that the shielding material exhibits high noise shielding performance.

[0021]

[10] In any one of the above aspects [1] to [9], the contact resistance at the electrical connection between the conductor wire of the ground line and the metal layer of the shielding material may be 60 Ω or less. This allows the current generated by noise shielding to easily flow to the ground potential via the electrical connection between the conductor of the ground line and the metal layer of the shielding material, thereby enabling effective noise shielding by the shielding material.

[0022]

[11] In any one of the above aspects [1] to

[10] , the shielding material may cover 60% or more of the surface area of ​​the electric wire group, excluding an area required for connecting the electric wires constituting the electric wire group to an external member. In this way, the shielding material can effectively provide noise shielding for the communication electric wires included in the electric wire group.

[0023]

[12] In any one of the above aspects [1] to

[11] , the shielding material is divided into a plurality of divided shielding materials to cover the surface of the electric wire group, and at least a part of the plurality of divided shielding materials is a ground connection shielding material whose metal layer is electrically connected to the conductor wire of the ground line, and the ratio of the area of ​​the ground connection shielding material to the total area of ​​the plurality of divided shielding materials is 35% or more. By dividing the shielding material into a plurality of divided shielding materials, even if the electric wire group and the base material have various shapes, the divided shielding materials can be combined to cover the surface of the electric wire group with the shielding material without excess or deficiency, making it easy to provide noise shielding. If the ratio of the ground connection shielding material to the total area of ​​the divided shielding materials is 35% or more, the current generated by noise shielding can be sufficiently passed to the ground potential via the ground line, and high noise shielding performance can be obtained.

[0024]

[13] In any one of the above aspects [1] to

[12] , the group of electric wires may include six or more communication electric wires (six sets). When the group of electric wires includes six or more communication electric wires (six sets), if noise shielding is applied to each communication electric wire individually, the space saving effect is reduced and the labor and cost required for noise shielding increases significantly. However, by collectively shielding all communication electric wires with a common sheet-like shielding material, these problems can be alleviated.

[0025] [Details of the embodiment of the present disclosure] Hereinafter, a wire harness according to an embodiment of the present disclosure will be described in detail with reference to the drawings. In this specification, terms such as "parallel" that indicate the shape or arrangement of members include not only a strict geometrical concept but also an error range that is generally acceptable for a wire harness, such as about ±15% in length or about ±15° in angle.

[0026] <Overall structure of wire harness> First, the overall structure of a wire harness according to an embodiment of the present disclosure will be described. Fig. 1 shows a plan view of a wire harness 1 according to an embodiment of the present disclosure, and Fig. 2 shows a cross section of the wire harness 1 cut perpendicularly to the axial direction near an end portion. In this specification, each direction, such as the up-down direction and the lateral direction (width direction), is defined as the direction shown in Fig. 2.

[0027] The wire harness 1 according to the present embodiment includes an electric wire group 2, a ground wire 3, a substrate 4, and a shielding material 5. In Fig. 1, the insulating coating of the electric wires constituting the electric wire group 2 and the shielding material 5 is shown being removed in stages at the end portion.

[0028] The wire group 2 constituting the wire harness 1 includes a plurality of communication wires 20. The type of the communication wires 20 is not particularly limited, but at least one of the plurality of communication wires 20 included in the wire group 2, and preferably all of them, may be configured as parallel wires. The parallel wires are communication wires in which a pair of insulated wires 21, each having an insulating coating 21b formed on the outer periphery of a conductor 21a, are arranged with their axes aligned. The number of communication wires 20 included in the wire group 2 is not particularly limited, but is preferably six (six pairs) or more. The wire group 2 may be configured only of a plurality of communication wires 20, or may include other types of wires in addition to the communication wires 20. In the illustrated embodiment, the wire group 2 is configured of two (two pairs) of communication wires 20, and each of the two communication wires 20 is configured as a parallel wire. It is preferable that each of the communication electric wires 20 constituting the electric wire group 2 does not have a noise shielding member such as a metal member surrounding the outer periphery of the signal wire.

[0029] The ground wire 3 is an electric wire that can be connected to an external ground potential. In the wire harness 1 according to the present embodiment, the ground wire 3 is configured as an insulated electric wire including a conductor wire 31 and an insulating coating 32. The detailed configuration of the ground wire 3 is not particularly limited, and a conventional insulated electric wire can be used as the ground wire 3. For example, an insulated electric wire may be used in which the conductor wire 31 is configured as a twisted wire in which a plurality of wires made of a metal such as copper or a copper alloy, or aluminum or an aluminum alloy, are twisted together, and the insulating coating 32 made of a resin composition including a chlorine-based resin such as polyvinyl chloride (PVC) or a polyolefin-based resin such as polypropylene (PP) is formed on the outer periphery of the conductor wire 31.

[0030] Each electric wire constituting the electric wire group 2 is fixed to the substrate 4. That is, each electric wire is arranged horizontally with its axial direction aligned in parallel, and each is fixed to the surface of the substrate 4. The substrate 4 serves to bundle the multiple electric wires constituting the electric wire group 2 into one, and also functions as a buffer member that suppresses damage to each electric wire constituting the electric wire group 2 caused by physical stimulation such as contact between the electric wire group 2 and the member on which the wire harness 1 is to be installed, such as a metal member that constitutes an automobile.

[0031] The base material 4 is not particularly limited in type as long as it has a surface on which the electric wires constituting the electric wire group 2, including the communication electric wire 20, can be aligned and fixed. However, from the viewpoint of ensuring the wiring of the wire harness 1, it is preferable that the base material 4 is made of a sheet body, that is, a planar member having flexibility. As the sheet body, a fabric such as a woven fabric, a nonwoven fabric, or a knitted fabric, a resin sheet, etc. can be used. The method of fixing the electric wire group 2 to the base material 4 is not particularly limited, and examples of the fixing include fusion, sewing, adhesion using an adhesive or a pressure-sensitive adhesive, and fixing using a fixing member such as a fastener. Among them, from the viewpoints of the reliability of fixing, space saving, and the small number of members required for fixing, it is preferable to fix each electric wire constituting the electric wire group 2 to the base material 4 by fusion. When a nonwoven fabric is used as the base material 4, it is easy to fix each electric wire firmly and easily by using fusion. In addition, a high cushioning effect can be obtained. The material of the base material 4 is not particularly limited, and various resin materials can be suitably used, such as polyethylene resins such as polyethylene terephthalate (PET), chlorine resins such as PVC, polyolefin resins such as PP, etc. The base material 4 may be made of a combination of a plurality of materials.

[0032] The shielding material 5 is configured as a sheet body including a metal layer 51. The configuration of the shielding material 5 will be described in detail later, but the shielding material 5 is arranged in the wire harness 1 so as to cover the surface of the electric wire group 2, that is, the surface (upper surface) of the assembly of all the electric wires that constitute the electric wire group 2. The shielding material 5 is fixed to the base material 4 on both sides in the width direction of the electric wire group 2. In the illustrated embodiment, the shielding material 5 has the metal layer 51, the resin film 52, and the adhesive layer 53 in this order, and the shielding material 5 is arranged with the surface of the adhesive layer 53 facing inward, that is, toward the side where the electric wire group 2 is arranged.

[0033] In the wire harness 1, the conductor wire 31 of the ground wire 3 is electrically connected to the metal layer 51 of the shielding material 5 covering the electric wire group 2 by the electrical connection portion 6. The position of the ground wire 3 relative to the electric wire group 2 and the shielding material 5, and the structure of the electrical connection portion 6 between the metal layer 51 of the shielding material 5 and the conductor wire 31 of the ground wire 3 are not particularly limited, but in the illustrated embodiment, the ground wire 3 is provided outside the shielding material 5, that is, outside the space in which the shielding material 5 covers the electric wire group 2. The ground wire 3 is provided overlapping a partial region of the end of the shielding material 5 along the axial direction of the electric wire group 2 (the left-right direction in FIG. 1), and extends to the outside of the wire harness 1. Note that FIG. 2 shows a cross section of the region in which the ground wire 3 is provided near the end of the entire length of the wire harness 1.

[0034] At the end of the ground line 3, the insulating coating 32 is removed to expose the conductor line 31, and the electrical connection 6 is formed at the exposed portion of the conductor line 31. At the electrical connection 6, the exposed conductor line 31 of the ground line 3 directly contacts the metal layer 51 of the shielding material 5, or indirectly contacts the metal layer 51 via a conductive member, so that an electrical connection is formed and maintained between the conductor line 31 and the metal layer 51. The electrical connection 6 may be formed and maintained by any configuration or mechanism between the conductor line 31 and the metal layer 51, and examples of the electrical connection include terminal connection, welding, soldering, and fixing with a conductive adhesive tape or an insulating adhesive tape. The embodiment in FIG. 1 assumes a configuration in which a connection terminal is used for the electrical connection 6, and in particular a configuration in which a piercing terminal is used. The piercing terminal has a claw-shaped piercing portion at its tip, and the piercing portion of the piercing terminal to which the ground line 3 is connected is pierced into the metal layer 51 of the shielding material 5 to electrically connect the ground line 3 and the metal layer 51.

[0035] 3 is a schematic plan view showing a connection state of the wire harness 1 according to the present embodiment. The ground wire 3 is connected to an external ground potential (GND) at an end portion opposite to the electrical connection portion 6, which extends outside the wire harness 1. In the wire harness 1, the ground wire 3 may be installed and connected to a ground potential at least at one end portion along the axial direction of the electric wire group 2. However, as shown in the figure, it is preferable to install the ground wire 3 at both ends and connect each ground wire 3 to a common ground potential. Although not shown in the figure, each electric wire constituting the electric wire group 2 is connected to a predetermined device or electric component, such as a communication device in the automobile, via an electrical connection member such as a connection terminal as appropriate.

[0036] In the wire harness 1 according to the present embodiment, a plurality of electric wires constituting the electric wire group 2 are arranged side by side and fixed to the base material 4, resulting in a wire harness 1 with excellent space saving in the height direction. The surface of the electric wire group 2 is covered with the shielding material 5 having the metal layer 51, so that the shielding material 5 plays a role of noise shielding for the plurality of communication electric wires 20 included in the electric wire group 2. That is, the shielding material 5 plays a role of shielding electromagnetic waves originating from the outside of the wire harness 1, suppressing the generation of noise in the communication electric wires 20, and shielding electromagnetic waves emitted from the communication electric wires 20 to the outside, suppressing the emitted electromagnetic waves from becoming a cause of noise outside. Since the conductor wire 31 of the ground line 3 is electrically connected to the metal layer 51 constituting the shielding material 5, if the ground line 3 is connected to an external ground potential (GND), a current generated by noise shielding flows to the ground potential via the ground line 3, thereby exhibiting high noise shielding performance.

[0037] In this embodiment, the common sheet-like shielding material 5 can be used to collectively shield the communication electric wires 20 included in the electric wire group 2, so that the increase in the dimensions of the wire harness 1 in the height direction and width direction due to noise shielding is suppressed to only the dimensions required for arranging the sheet of the shielding material 5. Therefore, the space-saving properties of the wire harness 1 can be kept high compared to the case where a noise shielding member is provided individually for each communication electric wire 20. In addition, the labor and cost required for noise shielding can be reduced. In particular, when the communication electric wires 20 are parallel electric wires, the space-saving properties of the wire harness 1 in the height direction are increased compared to the case where a pair of insulated electric wires 21 are twisted together, and the wire harness 1 can be easily fixed to the base material 4 by fusion or the like. The cost required for twisting the insulated electric wires 21 can also be saved. On the other hand, parallel electric wires are prone to common noise because they do not have a twisted structure like twisted electric wires, but the wire harness 1 has the shielding material 5, which reduces the effect of common noise in parallel electric wires, making it possible to suitably use the wire harness 1 for electrical communications inside automobiles, etc. The greater the number of electric wires included in the electric wire group 2, including the communication electric wires 20, the greater the effect of improving space saving and reducing labor and costs by using the sheet-like shielding material 5. For example, a particularly high effect can be obtained when the electric wire group 2 includes six (six pairs) or more, or even eight (eight pairs) or more, of the communication electric wires 20 such as parallel electric wires.

[0038] It is important to provide the ground wire 3 in the wire harness 1 and release the eddy current generated in the metal layer 51 of the shielding material 5 due to noise shielding to the ground potential via the ground wire 3 in order to maintain high noise shielding performance for a long period of time. The ground wire 3 fulfills its function as long as it can be electrically connected to the metal layer 51 of the shielding material 5 at least at one point. Therefore, even if the wire harness 1 has a long structure, it is sufficient to provide the ground wire 3 only in a part of the area along the axial direction of the electric wire group 2. If the length of the ground wire 3 overlapped on the shielding material 5 is kept short, it contributes to saving space and reducing the weight of the wire harness 1. In addition, the material cost required for manufacturing the wire harness 1 can be reduced. In particular, as shown in Figs. 1 and 3, by providing the ground wire 3 in an area including at least one end of the shielding material 5 along the axial direction of the electric wire group 2, high convenience is obtained in forming the electrical connection portion 6 and connecting to the ground potential. When providing the ground wires 3 at both end portions, as shown in the figure, it is preferable to separate the ground wires 3 on both sides from each other and provide a region in the middle along the axial direction of the electric wire group 2 where the ground wires 3 are not arranged. The ground wires 3 may be provided inside the space in which the electric wire group 2 is covered by the shielding material 5, but providing them on the outside as shown in the figure is preferable in terms of the simplicity and space-saving nature of the structure of the wire harness 1 and the convenience of forming the electrical connection portion 6, etc.

[0039] <Shielding material composition> Next, there will be described details of the shielding material 5 constituting the wire harness 1. As described above, the shielding material 5 covers the electric wire group 2 in the wire harness 1 and plays a role of noise shielding for the communication electric wires 20 included in the electric wire group 2.

[0040] As long as the shielding material 5 has the metal layer 51, the details of the configuration are not particularly limited. However, as shown in the cross-sectional view of Fig. 4, it is preferable that the shielding material 5 has a resin film 52 in addition to the metal layer 51, and the metal layer 51 is provided on the surface of the resin film 52. By providing the shielding material 5 with the resin film 52, the mechanical strength of the shielding material 5 is increased and the handleability of the shielding material 5 is improved, compared to a case in which the shielding material 5 is formed from an independent metal foil. The metal layer 51 may be formed by adhering it to one side of the resin film 52 by vapor deposition, plating, adhesion, or the like.

[0041] In addition, the shielding material 5 preferably has an adhesive layer 53 on a surface facing inward when covering the electric wire group 2. The adhesive layer 53 is configured as a layer of adhesive, that is, a pressure-sensitive adhesive. When the shielding material 5 has the resin film 52, as shown in FIG. 4, the adhesive layer 53 is provided on the surface of the resin film 52 opposite to the surface on which the metal layer 51 is provided, and the shielding material 5 may be incorporated into the wire harness 1 with the surface on which the adhesive layer 53 is provided facing inward and the surface on which the metal layer 51 is provided facing outward. When the shielding material 5 is configured of an independent metal layer 51 (metal foil) and does not have the resin film 52, the adhesive layer 53 may be provided directly on the surface of the metal layer 51. By using the adhesive layer 53, the shielding material 5 covering the electric wire group 2 can be easily fixed to the base material 4. In addition, by using the adhesive layer 53 to fix the shielding material 5 in close contact with the electric wire group 2, high noise shielding performance for the electric wire group 2 can be exhibited. The area on the surface of the shielding material 5 where the adhesive layer 53 is provided is not particularly limited, and the adhesive layer 53 may be provided over the entire surface of the shielding material 5, or the adhesive layer 53 may be provided only in a partial area of ​​the surface, for example, by arranging the adhesive in a predetermined pattern.

[0042] In the shielding material 5, the specific constituent materials of the metal layer 51, the resin film 52, and the adhesive layer 53 are not particularly limited. Examples of metals constituting the metal layer 51 include copper, copper alloys, aluminum, aluminum alloys, silver, silver alloys, and materials in which the surfaces of these metals are plated with tin, nickel, silver, gold, or the like. Among these, aluminum or aluminum alloys can be preferably used. As the constituent material of the resin film 52, various resin materials can be preferably used, such as polyethylene-based resins such as polyethylene terephthalate (PET), chlorine-based resins such as polyvinyl chloride (PVC), and polyolefin-based resins such as polypropylene (PP). As the adhesive constituting the adhesive layer 53, acrylic adhesives, silicone adhesives, urethane adhesives, and the like can be preferably used.

[0043] In the shielding material 5, the thickness of each layer of the metal layer 51, the resin film 52, and the adhesive layer 53 is not particularly limited. The thickness of the metal layer 51 is preferably 10 μm or more, and more preferably 15 μm or more. In this way, the shielding material 5 can easily obtain high noise shielding performance. On the other hand, the thickness of the metal layer 51 is preferably kept to 1 mm or less, and more preferably 100 μm or less. In this way, the rigidity of the shielding material 5 can be suppressed, and high flexibility that is convenient for covering the surface of the electric wire group 2 and bending the wire harness 1 can be ensured in the shielding material 5. The thickness of the resin film 52 can be preferably exemplified in the range of 10 μm or more, more preferably 15 μm or more, and 1 mm or less. The thickness of the adhesive layer 53 can be preferably exemplified in the range of 20 μm or more, more preferably 50 μm or more, and 1 mm or less.

[0044] As described above, the metal layer 51 of the shielding material 5 is electrically connected to the conductor wire 31 of the ground line 3 at the electrical connection portion 6, and the contact resistance between the metal layer 51 and the conductor wire 31 at the electrical connection portion 6 is preferably suppressed to 60Ω or less, further 10Ω or less, and further 2Ω or less. By suppressing the contact resistance at the electrical connection portion 6 low, the current generated in the metal layer 51 during noise shielding is easily passed through the conductor wire 31 to the ground potential, and high noise shielding properties are obtained. The lower the contact resistance, the more preferable it is, and no lower limit is particularly set. The contact resistance depends on the type of the electrical connection portion 6, the specific structure of the electrical connection portion 6, the connection strength, etc. When using the terminal connection using the piercing terminal or the like, welding, soldering, or fixing using a conductive adhesive tape as exemplified above, the contact resistance is easily suppressed to a low level. In particular, when using the piercing terminal, the ease of forming the electrical connection between the metal layer 51 and the conductor wire 31 and the stability of holding the formed electrical connection are also excellent. On the other hand, if fixing is performed using insulating adhesive tape, the contact resistance is likely to be high.

[0045] In the wire harness 1, the coverage of the shielding material 5 on the surface of the electric wire group 2 is preferably 60% or more, and more preferably 80% or more. Here, the coverage of the shielding material 5 is the ratio of the area of ​​the surface of the electric wire group 2 covered by the shielding material 5, and refers to the ratio of the area of ​​the area covered by the shielding material 5 to the area occupied by the electric wire group 2 when the wire harness 1 is viewed from above. However, the coverage is evaluated excluding the area necessary for connecting each electric wire constituting the electric wire group 2 to an external member, and may be evaluated by excluding an area of ​​80 mm from the terminal of each electric wire of the electric wire group 2, for example. If the coverage of the shielding material 5 is 60% or more, and more preferably 90% or more, the noise shielding effect of the metal layer 51 can be sufficiently exerted on the communication electric wires 20 included in the electric wire group 2. There is no upper limit to the coverage, and a form of 100% is most preferable.

[0046] <Transformation> 1 to 3 and described above, the entire shielding material 5 provided in the wire harness 1 is integral and continuous. However, the present invention is not limited to such an embodiment, and the shielding material 5 may be divided into a plurality of parts.

[0047] 5A is a schematic plan view of a wire harness 1' according to a modified embodiment of the present disclosure, in which a shielding material is divided into a plurality of divided shielding materials 5'. In the wire harness 1' according to this modified embodiment, a plurality of divided shielding materials 5' cover the surface of the group of electric wires 2, rather than a continuous shielding material. In the illustrated embodiment, three divided shielding materials 5' are provided. The configuration of each divided shielding material 5', including the layered configuration, is the same as the configuration of the shielding material 5 described in detail above, and only the area is different.

[0048] The arrangement pattern of the divided shielding materials 5' is not particularly limited, and examples include a form in which a plurality of divided shielding materials 5' are provided in the width direction of the electric wire group 2 in which a plurality of electric wires are arranged, and a form in which a plurality of divided shielding materials 5' are provided along the axial direction of the electric wire group 2 as shown in Fig. 5A. In particular, when the width of the area to be covered with the shielding material changes along the axial direction of the electric wire group 2, or when the area branches off at an intermediate location, by arranging a plurality of divided shielding materials 5' of different widths side by side along the axial direction of the electric wire group 2, each area can be covered with the divided shielding materials 5' without excess or deficiency.

[0049] When a plurality of divided shielding materials 5' are provided, it is preferable to overlap the ends of two divided shielding materials 5' without providing a gap between adjacent divided shielding materials 5' from the viewpoint of increasing the efficiency of noise shielding. However, when the divided shielding material 5' has a resin film 52 and an adhesive layer 53, in the area where the two divided shielding materials 5' overlap, as shown in Fig. 5B, the resin film 52 and the adhesive layer 53 are interposed between the metal layer 51 of one divided shielding material 5' and the metal layer 51 of the other divided shielding material 5'. Then, since the resin film 52 and the adhesive layer 53 are usually insulating, no conduction occurs between the metal layers 51 of the two adjacent divided shielding materials 5'. As shown in Figure 5A, even if a ground wire 3 is attached to the divided shielding materials 5'(a, c) at both ends of multiple divided shielding materials 5' arranged side by side and connected to ground potential via the ground wire 3, the divided shielding materials 5' other than the divided shielding materials 5' at both ends (ground-connected shielding materials), in the illustrated form, the central divided shielding material 5'(b), will remain unconnected to ground potential.

[0050] Even if some of the divided shielding materials 5' among the multiple divided shielding materials 5' are not connected to the ground potential, the wire harness 1' can obtain a certain degree of noise shielding performance, but by suppressing the ratio of the divided shielding materials 5' that are not connected to the ground potential to a low level, a higher noise shielding performance can be obtained. For example, by setting the divided shielding material 5' in which the metal layer 51 is electrically connected to the conductor wire 31 of the ground wire 3 as the ground-connected shielding material and setting the ratio of the area of ​​the ground-connected shielding material to the total area of ​​all the divided shielding materials 5' (ground connection area ratio) to 35% or more, or even 50% or more, a good noise shielding performance can be obtained. The higher the ground connection area ratio, the more preferable, and a form of 100% is most preferable. The ground connection area ratio can be changed depending on the division and arrangement pattern of the divided shielding material 5' and the structure of the portion where the divided shielding material 5' is adjacent, etc.

[0051] <Other forms> In the above-described embodiment, the ground line 3 is configured as an insulated wire, and the conductor wire 31 of the ground line 3 is electrically connected to the metal layer 51 of the shielding material 5 (or the divided shielding material 5'; the same applies below) at the electrical connection portion 6, thereby connecting the metal layer 51 to the ground potential via the ground line 3. However, the method of ensuring electrical contact between the ground line 3 and the metal layer 51 of the shielding material 5 is not limited to this form. For example, the ground line 3 may be configured as a drain line made of a bare conductor wire 31, and the drain line may be brought into contact with the metal layer 51 of the shielding material 5 directly or via a conductive material such as a conductive adhesive, thereby forming electrical contact between the drain line and the metal layer 51. In that case, it is preferable to arrange the drain line in parallel with the electric wire group 2, and to cover the surface of the assembly of the electric wire group 2 and the drain line with the shielding material 5 with the surface of the metal layer 51 facing inward. The adhesive layer 53 may be formed partially on the surface of the metal layer 51, or may be formed using a conductive adhesive.

[0052] In addition, although the above mainly describes a form in which the adhesive layer 53 is provided on the shielding material 5, the adhesive layer 53 may be omitted. In that case, however, it becomes necessary to fix the shielding material 5 to the base material 4 by applying an adhesive (including a pressure-sensitive adhesive) or using a fixing member such as a pin at the locations where the shielding material 5 contacts the base material 4 on both sides in the width direction of the electric wire group 2. In this case, it will require labor and cost to apply the adhesive or install the fixing member.

[0053] It is also possible to provide noise shielding by sandwiching the electric wire group 2, in which a plurality of electric wires are arranged horizontally, from both above and below with a sheet-like shielding material 5 having a metal layer 51 used in the wire harness 1 (1') according to the embodiment of the present disclosure, or by surrounding the outer periphery of the electric wire group 2 with a similar shielding material 5. However, in these configurations, two metal layers 51 are arranged vertically, and eddy currents of opposite phases may be generated between the two metal layers 51. The eddy currents of opposite phases hinder noise shielding by the metal layers 51. Therefore, these configurations are not preferable. For the same reason, a configuration in which the metal layers 51 are formed on both sides of the resin film 52 in one shielding material is also not preferable. As explained above, a configuration in which the shielding material 5 having the metal layer 51 formed only on one side of the resin film 52 is arranged only on the upper side of the electric wire group 2 is preferable. EXAMPLES

[0054] Examples are shown below. However, the present invention is not limited to these examples. Here, the relationship between the configuration of the wire harness and the noise shielding performance was examined.

[0055] <Test Method> As shown in each figure, a group of eight communication wires (eight pairs) each configured as parallel wires was fixed to a substrate, the surface of the group of wires was covered, a sheet-like shielding material was placed on it, and the wires were fixed to the substrate on both sides in the width direction. Furthermore, as shown in Fig. 3, ground wires were attached near both ends of the shielding material, and electrical connections were formed between the conductor wires of the ground wires and the metal layer of the shielding material. Here, the insulated wires constituting each parallel wire were made of conductors with a cross-sectional area of ​​0.5 mm 2 The ground wire used was a conductor with a cross-sectional area of ​​0.5 mm2 and a stranded aluminum alloy wire. 2An insulated wire with an outer diameter of 0.85 mm was used, with a PVC layer formed around the conductor wire as an insulating coating. A forming material made by bonding PVC and nonwoven fabric was used as the base material. Depending on the contact resistance to be set, the electrical connection between the conductor wire of the ground line and the metal layer of the shielding material was made by terminal connection using a piercing terminal, soldering, or fixing with conductive adhesive tape or insulating adhesive tape.

[0056] The shielding material used was a PET film as a resin film with an aluminum layer as a metal layer on one surface and an adhesive layer on the other surface, as shown in Figure 4. An acrylic adhesive was used as the adhesive that constitutes the adhesive layer. The shielding material was fixed to the substrate, with the adhesive layer facing inward, to cover the electric wires.

[0057] As shown in Table 1 below, the thickness of each layer in the shielding material, the contact resistance between the metal layer of the shielding material and the conductor wire of the ground line, the coverage rate of the shielding material in the wire harness, and the ground connection area rate of the divided shielding material were varied in multiple samples. The contact resistance was varied depending on whether the electrical connection between the conductor wire and the metal layer was made by terminal connection using a piercing terminal, soldering, fixing with conductive adhesive tape, or fixing with insulating adhesive tape. Furthermore, when conductive adhesive tape was used, the contact resistance was finely varied by the number of sheets of conductive adhesive tape attached. The coverage rate of the shielding material was adjusted by providing an area at the end of the wire harness that was not covered with the shielding material and changing the length of that area. The coverage rate in Table 1 is the value evaluated for the area excluding an area 80 mm long from both ends of the electric wire group. For the ground connection area rate to be 100%, one continuous sheet of shielding material was used. On the other hand, when the ground connection area ratio is set to less than 100%, multiple divided shielding materials are arranged in the axial direction of the wire group, and divided shielding materials other than those at both ends are not connected to the ground potential, as shown in Fig. 5A. Furthermore, the area of ​​the divided shielding materials that are not connected to the ground potential is adjusted to change the ground connection area ratio.

[0058] The noise shielding performance of the shielding material was evaluated for each wire harness prepared as described above. The evaluation was performed by measuring the radiated emission by the antenna irradiation method (ALSE method) conforming to the standard CISPR25 of the International Special Committee on Radio Interference (CISPR). Specifically, a wire harness was prepared as a sample with a section length of 1.2 m in which eight (8 pairs) communication electric wires were arranged as parallel electric wires. At both ends of the section, a section of 5.4 m in length was formed in which a pair of insulated electric wires constituting each communication electric wire were twisted together. The sample was placed in an anechoic chamber, and a rod antenna was placed 1.0 m to the side from the center of the section arranged as parallel electric wires. Then, an electric signal with a frequency of 0.53 to 1.8 MHz was input to each communication electric wire constituting the wire harness, and the amount of noise radiation at this time was measured by the rod antenna. Note that the section in which the insulated electric wires are twisted together does not contribute much to noise radiation.

[0059] The peak value of the measurement value for eight (eight pairs) communication wires was used as the noise radiation amount. In other words, the maximum value of the peak value in the frequency range of 0.53 to 1.8 MHz was recorded as the noise radiation amount. The smaller the noise radiation amount, the higher the noise shielding performance of the shielding material. When the noise radiation amount exceeds 56 dBμV / m, which is the limit value corresponding to Class 3 of the MW band (frequency 0.53 to 1.8 MHz) of CISPR25, the noise shielding performance was determined to be low (B). On the other hand, when the noise radiation amount is 56 dBμV / m or less, the noise shielding performance was determined to be high (A), and further, when the noise radiation amount is 48 dBμV / m or less, which is the limit value corresponding to Class 4 of CISPR25, the noise shielding performance was determined to be particularly high (A+).

[0060] <Test Results> Table 1 below shows the composition of the shielding material, as well as the noise radiation measured for each sample and the evaluation results of the noise shielding performance.

[0061] [Table 1]

[0062] According to Table 1, in sample 25, in which no shielding material is provided in the wire harness, the noise radiation exceeds 56 dBμV / m. In contrast, in samples 1 to 24, in which a shielding material having a metal layer is provided, the noise radiation is suppressed to 56 dBμV / m or less, and high noise shielding performance is obtained. From this, it is confirmed that by providing noise shielding by covering multiple communication electric wires, each of which is configured as a parallel electric wire, collectively with a sheet-like shielding material, it is possible to achieve sufficiently high noise shielding performance for each communication electric wire.

[0063] Among the samples 1 to 24, the set of samples 1 to 3 and the set of samples 7 and 12 are uniform in contact resistance, shielding material coverage, and ground connection area ratio, respectively, and are different from each other in the thickness of the metal layer. In each set, the noise radiation tends to decrease as the metal layer thickness increases. In addition, the metal layer thickness, shielding material coverage, and ground connection area ratio of samples 3 to 11 are uniform, and the contact resistance between the metal layer of the shielding material and the conductor wire of the ground line is different from each other. In these samples, the noise radiation tends to decrease as the contact resistance decreases. The metal layer thickness, contact resistance, and ground connection area ratio of samples 13 to 16 are uniform, and the shielding material coverage is different from each other. In these samples, the noise radiation tends to decrease as the shielding material coverage is increased. The metal layer thickness, contact resistance, and shielding material coverage of samples 4 and 17 to 24 are uniform, and the ground connection area ratio is different from each other. In these samples, the noise radiation tends to decrease as the ground connection area ratio increases.

[0064] In particular, in samples 1-10, 13-15, and 17-23, in which the thickness of the metal layer is 10 μm or more, the contact resistance is 60 Ω or less, the coverage rate of the shielding material is 60% or more, and the ground connection area rate is 35% or more, the noise radiation amount is suppressed to 48 dBμV / m or less, and a particularly high noise shielding performance evaluated as A+ is obtained. The adhesive layer and the resin film do not contribute to the noise shielding by the metal layer, and the thickness of the adhesive layer and the thickness of the resin film have almost no effect on the noise shielding performance. This is also shown by the fact that the correlation between the thickness of the metal layer, the contact resistance, the coverage rate of the shielding material, the ground connection area rate, and the noise radiation amount is established beyond the difference in the thickness of the adhesive layer and the thickness of the resin film.

[0065] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention. [Explanation of symbols]

[0066] 1,1' Wire Harness 2 wire groups 20 Communication wires 21 Insulated wire 21a Conductor 21b Insulation coating 3 Ground wire 31 Conductor wire 32 Insulation coating 4 Base material 5 Shielding material 5' split shielding 51 Metal layer 52 Resin film 53 Adhesive layer 6 Electrical Connections

Claims

1. A group of electric wires including a plurality of communication electric wires; a ground line including a conductor wire and an insulating coating covering the conductor wire, the ground line being connectable to a ground potential; A substrate; A sheet-like shielding material having a metal layer, Each electric wire constituting the electric wire group is fixed to the base material, the shielding material covers a surface of the group of electric wires and is fixed to the base material; The conductor wire of the ground wire is electrically connected to the metal layer of the shielding material.

2. The wire harness according to claim 1 , wherein the communication electric wire is configured as a pair of parallel electric wires insulated electric wires arranged with their axes aligned.

3. The wire harness according to claim 1 or 2, wherein the shielding material further comprises a resin film, and the metal layer is provided on a surface of the resin film.

4. the shielding material further has an adhesive layer made of an adhesive on a surface of the resin film opposite to the surface on which the metal layer is provided, The wire harness according to claim 3 , wherein the shielding material covers the group of electric wires with the surface on which the adhesive layer is provided facing inward, and is fixed to the base material and the group of electric wires by the adhesive layer.

5. 3. The wire harness according to claim 1, wherein the ground wire is provided only in a partial area along an axial direction of the group of electric wires.

6. The wire harness according to claim 5 , wherein the ground wire is provided in a region including at least one end of the shielding material along an axial direction of the group of electric wires.

7. 3. The wire harness according to claim 1, wherein the ground wire is disposed outside a space in which the shielding material covers the group of electric wires.

8. 3. The wire harness according to claim 1, wherein an electrical connection between the conductor wire of the ground wire and the metal layer of the shielding material is formed by piercing a piercing terminal to which the ground wire is connected, into the metal layer.

9. The wire harness according to claim 1 or 2, wherein the metal layer has a thickness of 10 μm or more.

10. 3. The wire harness according to claim 1, wherein a contact resistance at an electrical connection portion between the conductor wire of the ground wire and the metal layer of the shielding material is 60Ω or less.

11. 3. The wire harness according to claim 1, wherein the shielding material covers 60% or more of a surface area of ​​the electric wire group, excluding an area required for connecting the electric wires constituting the electric wire group to an external member.

12. the shielding material is divided into a plurality of divided shielding materials and covers a surface of the group of electric wires, At least a part of the plurality of divided shielding materials is a ground connection shielding material having a metal layer electrically connected to the conductor line of the ground line, 3. The wire harness according to claim 1, wherein an area of ​​the ground-connecting shielding material occupies 35% or more of a total area of ​​the plurality of divided shielding materials.

13. The wire harness according to claim 1 or 2, wherein the group of electric wires includes six or more of the communication electric wires.

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