Wire harness

Abstract

The present invention is characterized by comprising a main shielded electric wire (10) in which a main electric wire (11) is covered by a tubular main braided body (12), the main electric wire being drawn out from an opening of a terminal (12a) of the main braided body, a sub-shielded electric wire (20) that runs alongside the main shielded electric wire and in which a sub-electric wire (21) is covered by a tubular sub-braided body (22), the sub-electric wire having a branch line (21a) branching outside the sub-braided body at a branch point (20a) along the sub-braided body, an annular shield bracket (30) that is ground-connected to a vehicle body, has the main electric wire passed therethrough, and has an outer peripheral surface covered by the terminal, which is expanded, of the main braided body, and a fixing member (40) circumferentially surrounding the terminal of the main braided body and crimping the terminal of the main braided body to the outer peripheral surface of the shield bracket, wherein: the branch line of the sub-electric wire is passed through the shield bracket while running alongside the main electric wire; and a branch line (22a) of the sub-braided body that starts from the branch point is passed between the terminal of the main braided body and the fixing member and is crimped to the shield bracket together with the terminal of the main braided body by the fixing member.

Description

Wire harness

[0001] The present invention relates to a wire harness.

[0002] Vehicles such as automobiles are equipped with wire harnesses that have been provided with noise countermeasures. This wire harness includes, for example, shielded electric wires for each circuit, each of which is formed by encasing an electric wire in a tubular braid. The braids of each shielded electric wire are grounded to the vehicle body to provide a shielding effect. Conventional wire harnesses connect each braid to a single grounding member and ground each braid to the vehicle body via this grounding member, thereby avoiding an increase in the number of components that would accompany grounding each braid. Examples of this type of wire harness are disclosed in Patent Documents 1 and 2 listed below. In the wire harnesses of Patent Documents 1 and 2, the end of the braid for each shielded electric wire is separated from the electric wire and the end of each braid is connected to a single grounding member.

[0003] JP 2019-179735 A JP 2020-115413 A

[0004] However, in conventional wire harnesses, the ends of the braid are separated from the wires for all shielded wires, resulting in areas of all the wires that are not covered by the braid. Therefore, there is room for improvement in the shielding performance of conventional wire harnesses.

[0005] SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a wire harness that can improve shielding performance.

[0006] The present invention relates to a main shield electric wire in which a main electric wire is covered inside a tubular main braid and the main electric wire is drawn out from an opening at an end of the main braid; at least one secondary shield electric wire running parallel to the main shield electric wire, a secondary electric wire covered inside a tubular secondary braid and a branch wire of the secondary electric wire branched out from the secondary braid at a branch point midway through the secondary braid; an annular shield bracket grounded to a vehicle body, into which the main electric wire is inserted and the expanded end of the main braid is fitted on an outer circumferential surface; and a fixing member that surrounds the terminal of the main braided body in the circumferential direction and crimps the terminal of the main braided body to the outer peripheral surface of the shield bracket, wherein the branch wire of the secondary electric wire is inserted into the shield bracket while running parallel to the main electric wire, and the branch wire of the secondary braided body starting from the branch point is passed between the terminal of the main braided body and the fixing member or between the terminal of the main braided body and the shield bracket, and is crimped to the shield bracket by the fixing member together with the terminal of the main braided body.

[0007] In the wire harness according to the present invention, the main shield electric wire and the secondary shield electric wire run parallel to each other, and the terminal of the main braid of the main shield electric wire and the branch wire of the secondary braid of the secondary shield electric wire are crimped to a shield bracket with a ground connection function using a fixing member. Therefore, the wire harness according to the present invention can reduce the number of parts compared to a case in which the main shield electric wire and the secondary shield electric wire are individually grounded. Furthermore, since the ground connection points of this wire harness can be consolidated in one location by the shield bracket, weight can be reduced and space can be saved when mounted on a vehicle. These effects increase as the number of secondary shield electric wires increases. Furthermore, in the wire harness according to the present invention, the terminal of the main braid of the main shield electric wire is crimped to the shield bracket without exposing the main electric wire, thereby improving shielding performance. Furthermore, in the wire harness according to the present invention, the secondary wire of the secondary shielded wire and the secondary braided body are branched within the terminal of the main braided body, and the branched wire of the secondary braided body is crimped and connected to the terminal of the main braided body and the shield bracket without exposing the secondary wire of the secondary shielded wire to the outside, thereby enabling further improvement in shielding performance.

[0008] Fig. 1 is a perspective view illustrating a wire harness of an embodiment. Fig. 2 is a perspective view illustrating a wire harness of an embodiment. Fig. 3 is a perspective view illustrating a main shielded electric wire and a secondary shielded electric wire of the wire harness of an embodiment. Fig. 4 is a partial cross-sectional view illustrating the wire harness of an embodiment. Fig. 5 is a perspective view illustrating a wire harness of a modified example. Fig. 6 is a perspective view illustrating a main shielded electric wire and a secondary shielded electric wire of the wire harness of a modified example. Fig. 7 is a partial cross-sectional view illustrating the wire harness of a modified example.

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a wire harness according to the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to these embodiments.

[0010] [Embodiment] One embodiment of a wire harness according to the present invention will be described with reference to Figs.

[0011] 1 and 2, reference numeral 1 designates a wire harness according to this embodiment. The wire harness 1 includes a main shield electric wire 10 and at least one secondary shield electric wire 20 running parallel to the main shield electric wire 10 (FIGS. 1 to 4). For example, in the wire harness 1, the main shield electric wire 10 and the secondary shield electric wire 20 are provided for each circuit. In the wire harness 1 shown here, the secondary shield electric wire 20 is thinner than the main shield electric wire 10, and one secondary shield electric wire 20 runs parallel to the main shield electric wire 10.

[0012] The main shield electric wire 10 includes a main electric wire 11 and a tubular main braid 12 that covers the main electric wire 11 ( FIGS. 1 to 4 ). The main electric wire 11 is a single electric wire or a bundle of electric wires. The main braid 12 is a tubular member in which metal wires are braided in a mesh-like pattern. In the main shield electric wire 10, the main electric wire 11 is pulled out from an opening at an end 12 a of the main braid 12 ( FIGS. 1 to 4 ).

[0013] The secondary shielded wire 20 includes a secondary electric wire 21 and a tubular secondary braid 22 that covers the inside of the secondary electric wire 21 (FIGS. 1 to 4). The secondary electric wire 21 is a single electric wire or a bundle of electric wires, similar to the main electric wire 11. The secondary braid 22 is a tubular, mesh-like member made of metal wires, similar to the main braid 12.

[0014] In this secondary shielded electric wire 20, the secondary electric wire 21 and the secondary braid 22 branch off from a branch point 20a located midway through the secondary braid 22 ( FIGS. 1 and 2 ). The secondary electric wire 21 has a branch line 21a that branches off from the secondary braid 22 starting from the branch point 20a ( FIGS. 1 to 4 ). The secondary braid 22 also has a branch line 22a that branches off from the secondary electric wire 21 starting from the branch point 20a ( FIGS. 1 to 4 ). In other words, in this secondary shielded electric wire 20, the branch line 21a of the secondary electric wire 21 branches off from the secondary braid 22 at the branch point 20a.

[0015] In this wire harness 1, the terminal 12a of the main braid 12 is expanded, and the branch wires 21a of the secondary electric wires 21 are inserted into the expanded terminal 12a of the main braid 12 ( FIGS. 1 to 4 ). For example, a through hole is formed in the terminal 12a of the main braid 12 for inserting the branch wires 21a of the secondary electric wires 21. Also, for example, the mesh of the terminal 12a of the main braid 12 is expanded to insert the branch wires 21a of the secondary electric wires 21. The branch wires 21a of the secondary electric wires 21 run parallel to the main electric wires 11 in the expanded terminal 12a of the main braid 12 ( FIGS. 1 to 4 ).

[0016] The wire harness 1 further includes an annular shield bracket 30 through which the main electric wire 11 is inserted and on which the terminal 12a of the expanded main braid 12 is fitted (FIGS. 1, 2, and 4). The branch wire 21a of the secondary electric wire 21 is inserted through the shield bracket 30 while running parallel to the main electric wire 11 (FIGS. 1, 2, and 4). The branch wire 21a of the secondary electric wire 21 shown here is inserted through the shield bracket 30 while running parallel to the main electric wire 11 within the terminal 12a of the expanded main braid 12.

[0017] This shield bracket 30 is formed from a metal material to prevent noise from entering the main electric wires 11 and secondary electric wires 21 inserted inside. The main body of the shield bracket 30 shown here is formed in a rectangular ring shape.

[0018] This shield bracket 30 is connected to the ground of a vehicle such as an automobile. Therefore, a connection portion for connecting to the ground of the vehicle body is provided on this shield bracket 30. Note that the shield bracket 30 may also be connected to the ground of the vehicle body via another conductive member.

[0019] The wire harness 1 includes a fixing member 40 that circumferentially surrounds the terminal 12 a of the main braid 12 and crimps the terminal 12 a of the main braid 12 to the outer peripheral surface of the shield bracket 30 ( FIGS. 1 , 2 , and 4 ). The fixing member 40 is, for example, a member that crimps the terminal 12 a of the main braid 12 to the outer peripheral surface of the shield bracket 30 with the terminal 12 a of the main braid 12 therebetween, and is formed into an annular shape from a metal material. The fixing member 40 may also be formed from a material other than a metal material, such as a synthetic resin material, as long as it can stabilize the adhesion between the terminal 12 a of the main braid 12 and the outer peripheral surface of the shield bracket 30 (i.e., the resistance value of the crimped portion).

[0020] The branch wires 22a of the secondary braid 22 are passed between the terminal ends 12a of the main braid 12 and the fixing member 40 ( FIGS. 1 , 2 , and 4 ). As a result, the branch wires 22a of the secondary braid 22 are interposed between the outer peripheral surface of the terminal ends 12a of the main braid 12 and the inner peripheral surface of the fixing member 40. The branch wires 22a of the secondary braid 22, together with the terminal ends 12a of the main braid 12, are crimped to the shield bracket 30 by the fixing member 40 ( FIGS. 1 , 2 , and 4 ). The branch wires 22a of the secondary braid 22 are crimped to the outer peripheral surface of the terminal ends 12a of the main braid 12, and are crimped to the shield bracket 30 via the terminal ends 12a of the main braid 12. Therefore, in the secondary braid 22, the branch wires 22a are formed into a flat braid to improve adhesion to the outer peripheral surface of the terminal ends 12a of the main braid 12. The secondary shield wire 20 shown here has, for example, two secondary wires 21 running in parallel, and these two secondary wires 21 are covered with a secondary braid 22 having a flat braid shape.

[0021] In the secondary braid 22, an excess length of the branch wire 22a exists beyond the crimped portion with the end 12a of the main braid 12, and this excess length is folded back (FIGS. 1, 2 and 4).

[0022] The wire harness 1 shown here includes a tubular member 50 made of synthetic resin, through which the main electric wire 11 and the branch wire 21a of the secondary electric wire 21 are inserted (see FIGS. 1, 2, and 4). The tubular member 50 is interposed between the main electric wire 11, the branch wire 21a of the secondary electric wire 21, and the shield bracket 30. The shield bracket 30 is then assembled to the tubular member 50.

[0023] As described above, in the wire harness 1 of this embodiment, the main shield wire 10 and the secondary shield wire 20 run parallel to each other, and the terminal 12 a of the main braid 12 of the main shield wire 10 and the branch wire 22 a of the secondary braid 22 of the secondary shield wire 20 are crimped and connected to the shield bracket 30 with a ground connection function using the fixing member 40. Therefore, the wire harness 1 of this embodiment can reduce the number of parts compared to a case in which the main shield wire 10 and the secondary shield wire 20 are individually grounded. Furthermore, since the ground connection points of this wire harness 1 can be concentrated in one location using the shield bracket 30, it is possible to reduce the weight and save space when the wire harness 1 is mounted on a vehicle. These effects become greater as the number of secondary shield wires 20 increases.

[0024] Furthermore, in the wire harness 1 of this embodiment, the main shielded electric wire 10 does not expose the main electric wire 11 to the outside, and the terminal 12 a of the main braided body 12 is crimped and connected to the shield bracket 30, thereby improving the shielding performance.

[0025] Furthermore, in the wire harness 1 of this embodiment, the shield bracket 30 is grounded to the vehicle body, so that the ground connection point is close, which also improves the shielding performance.

[0026] [Modification] Reference numeral 2 in FIG. 5 denotes a wire harness according to this modification.

[0027] The wire harness 2 of this modified example includes the same main shield wire 10 and at least one secondary shield wire 20 as the wire harness 1 of the above-described embodiment (FIGS. 5 to 7). In the wire harness 2 shown here, the secondary shield wires 20 are thinner than the main shield wires 10, and one secondary shield wire 20 runs parallel to the main shield wire 10, also in this modified example.

[0028] However, the wire harness 2 of this modified example is the same as the wire harness 1 of the embodiment in that the terminal 12a of the main braid 12 is expanded, but the secondary shield wire 20 is inserted into the expanded terminal 12a of the main braid 12, and the secondary wire 21 and the secondary braid 22 are branched in the terminal 12a of the main braid 12 ( FIGS. 6 and 7 ). Thus, the secondary shield wire 20 starts from a branch point 20a inserted into the expanded terminal 12a of the main braid 12, and the branch wire 21a of the secondary wire 21 runs parallel to the main wire 11 ( FIGS. 6 and 7 ).

[0029] The wire harness 2 of this modified example also includes the shield bracket 30 and the fixing member 40 similar to those of the wire harness 1 of the above-described embodiment (FIGS. 5 and 7). Furthermore, the wire harness 2 of this modified example also includes the tubular member 50 similar to those of the wire harness 1 of the above-described embodiment (FIGS. 5 and 7).

[0030] In this modified example, the terminal 12a of the expanded main braid 12 is also placed over the outer peripheral surface of the shield bracket 30 ( FIGS. 5 and 7 ). Also in this modified example, the branch wire 21a of the secondary electric wire 21 is inserted through the shield bracket 30 while running parallel to the main electric wire 11 within the terminal 12a of the expanded main braid 12 ( FIGS. 5 and 7 ). Therefore, in the secondary shield electric wire 20 of this modified example, the branch point 20a is provided within the terminal 12a of the main braid 12 and outside the shield bracket 30.

[0031] The branch wire 22a of the secondary braid 22 in this modified example is passed between the terminal 12a of the main braid 12 and the shield bracket 30 ( FIGS. 5 and 7 ). As a result, the branch wire 22a of the secondary braid 22 is interposed between the inner circumferential surface of the terminal 12a of the main braid 12 and the outer circumferential surface of the shield bracket 30 ( FIGS. 5 and 7 ). In this modified example, the branch wire 22a of the secondary braid 22 is also crimped to the shield bracket 30 together with the terminal 12a of the main braid 12 by the fixing member 40 ( FIGS. 5 and 7 ). The branch wire 22a of the secondary braid 22 in this modified example is crimped to the inner circumferential surface of the terminal 12a of the main braid 12 and the outer circumferential surface of the shield bracket 30, respectively.

[0032] In the secondary braid 22, even in this modification, there is an excess length of the branch wire 22a beyond the crimped portion with the terminal 12a of the main braid 12, so this excess length is folded back (FIGS. 5 and 7).

[0033] As described above, in the wire harness 2 of this modified example, the main shield wire 10 and the secondary shield wire 20 run parallel to each other, as in the wire harness 1 of the embodiment, and the terminal 12 a of the main braid 12 of the main shield wire 10 and the branch wire 22 a of the secondary braid 22 of the secondary shield wire 20 are crimped and connected to the shield bracket 30 with a ground connection function by the fixing member 40. Therefore, as in the wire harness 1 of the embodiment, the wire harness 2 of this modified example can reduce the number of parts, and can also reduce weight and save space when mounted on a vehicle, compared to a case in which the main shield wire 10 and the secondary shield wire 20 are individually grounded. These effects become greater as the number of secondary shield wires 20 increases.

[0034] Furthermore, in the wire harness 2 of this modified example, as in the wire harness 1 of the embodiment, the main shield electric wire 10 connects the terminal 12a of the main braid 12 to the shield bracket 30 by crimping without exposing the main electric wire 11 to the outside. In this wire harness 2, the secondary shield electric wire 20 is inserted into the terminal 12a of the main braid 12, and at the end where the secondary electric wire 21 and the secondary braid 22 are branched in the terminal 12a of the main braid 12, the branch wire 22a of the secondary braid 22 is crimped and connected to the terminal 12a of the main braid 12 and the shield bracket 30. In other words, in the wire harness 2 of this modified example, the branch wire 22a of the secondary shield electric wire 20 is also crimped and connected to the terminal 12a of the main braid 12 and the shield bracket 30 without exposing the secondary electric wire 21 to the outside. Therefore, the wire harness 2 of this modified example can improve the shielding performance more than the wire harness 1 of the embodiment.

[0035] Furthermore, in the wire harness 2 of this modified example, the shield bracket 30 is grounded to the vehicle body in the same manner as in the wire harness 1 of the embodiment, so that the ground connection point is close, which also improves the shielding performance.

[0036] For example, in a vehicle, an exhaust pipe of an internal combustion engine and a fuel tank are installed under the floor, and when a wire harness is routed under the floor, there is a limit to the installation space. Furthermore, in a vehicle, legal regulations require improved shielding performance of the wire harness routed under the floor. The wire harness 1 of the embodiment and the wire harness 2 of the modified example can appropriately meet these requirements.

[0037] REFERENCE SIGNS LIST 1, 2 Wire harness 10 Main shielded electric wire 11 Main electric wire 12 Main braided body 12a Terminal of main braided body 20 Secondary shielded electric wire 20a Branch point 21 Secondary electric wire 21a Branch wire of secondary electric wire 22 Secondary braided body 22a Branch wire of secondary braided body 30 Shield bracket 40 Fixing member

Claims

1. A main shield electric wire in which a main electric wire is covered inside a tubular main braid and the main electric wire is pulled out from an opening at an end of the main braid; at least one secondary shield electric wire running parallel to the main shield electric wire, a secondary electric wire is covered inside a tubular secondary braid and a branch wire of the secondary electric wire is branched off to the outside of the secondary braid at a branch point midway through the secondary braid; an annular shield bracket that is grounded to a vehicle body, through which the main electric wire is inserted inward and through which the expanded end of the main braid is placed on its outer circumferential surface; and a fixing member that surrounds the end of the main braid in the circumferential direction and crimps the end of the main braid to the outer circumferential surface of the shield bracket, wherein the branch wire of the secondary electric wire is inserted into the shield bracket while running parallel to the main electric wire, a branch wire of the secondary braided body starting from the branch point is passed between an end of the main braided body and the fixing member or between an end of the main braided body and the shield bracket, and is crimped to the shield bracket together with the end of the main braided body by the fixing member.

2. A wire harness as described in claim 1, wherein the branch wire of the secondary wire is inserted into the expanded terminal of the main braided body and is inserted into the shield bracket while running parallel to the main wire inside the terminal of the main braided body, and the branch wire of the secondary braided body is interposed between the outer peripheral surface of the terminal of the main braided body and the inner peripheral surface of the fixing member.

3. A wire harness as described in claim 1, wherein the secondary shielded electric wire is inserted into the expanded terminal of the main braided body at the branch point, the branch wire of the secondary electric wire is inserted into the shield bracket while running parallel to the main electric wire within the terminal of the main braided body, and the branch wire of the secondary braid is interposed between the inner surface of the terminal of the main braided body and the outer surface of the shield bracket.

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