WO2013168632A1

WO2013168632A1 - Wire harness

Info

Publication number: WO2013168632A1
Application number: PCT/JP2013/062577
Authority: WO
Inventors: 康志井谷; 不二夫薗田; 青山　直樹; 裕一木本; 佳典杉本
Original assignee: 株式会社オートネットワーク技術研究所; 住友電装株式会社; 住友電気工業株式会社
Priority date: 2012-05-10
Filing date: 2013-04-30
Publication date: 2013-11-14
Also published as: JP2013235749A

Abstract

The purpose of the present invention is to effectively shield noise electromagnetic waves which occur at a power cable, and to prevent an excessive amount of induction current from passing through a shield member. A wire harness is provided with three power cables for conducting symmetrical three-phase AC electricity, three first shield members for individually surrounding the periphery of the three power cables, and a second shield member for collectively surrounding the periphery of the three first shield members while the second shield member is electrically insulated from the three first shield members. The second shield member has a grain that is coarser than the first shield members and has a part to be grounded on both ends.

Description

Wire harness

The present invention relates to a wire harness including a conductive shield member surrounding a power cable.

2. Description of the Related Art Conventionally, a wire harness installed in a vehicle typified by a car may include a conductive shield member that surrounds the periphery of a wire and shields noise electromagnetic waves. The wire passed through the hollow portion of the shield member is usually a non-shielded wire. An unshielded electric wire is an insulated wire which is not covered by shield members, such as a braided wire.

For example, as disclosed in Patent Document 1, a wire harness of a vehicle may be provided with a braided wire formed of a cylindrically woven metal wire as a shield member. The braided wire is a cylindrical shield member having flexibility which can be deformed according to the deformation of the electric wire.

In addition, as disclosed in Patent Document 2, a wire harness laid in a place exposed to the outside such as a lower surface (under floor) of a bottom plate in an automobile includes a metal pipe which is a cylindrical protective member surrounding the periphery of an electric wire. There is a case. The metal pipe is a member that protects the electric wire from foreign matter such as gravel that splashes from the road, and is also a shield member that shields noise electromagnetic waves.

In a wire harness including a shield member, both end portions of the electric wire are wired into the housing from the opening of a metal housing that accommodates a device to be connected. Also, in order to obtain the effect of electrostatic shielding, the shield member is usually electrically connected to the metal casing at both ends. The metal casing is electrically connected to a reference potential body such as a car body, so the shield member is grounded via the casing. In this case, the shield member and the reference potential body form a closed loop with another conductive member such as a housing.

When the electric wire which a shield member encloses is a power cable which transmits alternating current, an induction current flows into the closed loop formed by a shield member and a reference electric potential object. Also, the induced current flowing through the shield member increases as the current value and frequency of the alternating current flowing through the power cable increase.

In addition, in electric vehicles such as electric vehicles and hybrid vehicles, a three-phase motor is adopted, and a wire harness connected to the three-phase motor is provided with three power cables for conducting symmetrical three-phase alternating current. In this case, the phase shift of electricity due to electromagnetic induction generated for each alternating current electricity of each phase is the same. In the following description, when the term “three-phase alternating current” is used without particular explanation, it means “symmetrical three-phase alternating current”, that is, three-phase alternating current whose phase shift (120 degrees) is the same. Means

When three power cables conducting three-phase alternating current are collectively enclosed by one shield member grounded at both ends, electromagnetic waves generated by alternating current of each phase flowing in each of the three power cables Induction occurs at one shield member. Therefore, three phase electricity of different phases generated by electromagnetic induction are mixed in one shield member and mutually cancel each other.

On the other hand, when three power cables conducting three-phase alternating current are individually surrounded by three shield members, and both ends of the shield members are grounded, each phase flowing in each of the three power cables The electromagnetic induction by the alternating current occurs individually for each shield member.

In the following description, a shield member that is grounded at both ends and collectively surrounds three power cables that conduct three-phase alternating current is referred to as a collectively enclosed shield member. In addition, a shield member which is grounded at both ends and individually surrounds each of the three power cables conducting three-phase alternating current is referred to as a separate surrounding shield member.

Japanese Patent Application Publication No. 2006-344398 JP, 2011-193677, A

Recently, in electric vehicles such as electric vehicles and hybrid vehicles, higher power and higher frequency of alternating current electricity supplied from an inverter circuit to a three-phase motor have been advanced. Therefore, when the separate surrounding shield member is adopted, an excessive induced current is likely to flow to each shield member. In addition, even when the power cable and the shield member are long, excessive induced current is likely to flow to each shield member.

When an excessive induced current flows in the shield member, there arises a problem that heat generated in the shield member may damage surrounding members.

On the other hand, when the encircling shield type shielding member is adopted, the three-phase induction currents mutually cancel each other, so that the problem of an excess current flowing in the shielding member does not occur, but a heavy and large shielding member is required. Because it is inconvenient to handle heavy and large shield members, it is desirable that no such shield members be employed. In addition, if a collective surrounding shield member made of a thin and coarse conductive member is adopted to reduce the weight of the shield member, the shielding performance of high frequency noise is mainly deteriorated.

SUMMARY OF THE INVENTION The object of the present invention is to effectively shield noise electromagnetic waves generated in a power cable conducting symmetrical three-phase alternating current, and to allow excessive induced current to flow in the shield member without adopting a heavy and large shield member. It is to prevent.

A wire harness according to a first aspect of the present invention includes the components shown below.
(1) The first component is three power cables that conduct symmetrical three-phase alternating current electricity.
(2) The second component is three conductive first shield members arranged in parallel at intervals and individually surrounding the periphery of each of the three power cables.
(3) The third component is a conductive member that is coarser than the first shield member, and has grounded portions electrically connected to the reference potential body at both ends, It is a second shield member that collectively surrounds the three first shield members in a state of being electrically insulated from the first shield member.

A wire harness according to a second aspect of the present invention is an aspect of the wire harness according to the first aspect. In the wire harness according to the second aspect, the first shield member is made of a material having higher electric conductivity than the second shield member, and the second shield member is made of a magnetic material.

A wire harness according to a third aspect of the present invention is an aspect of the wire harness according to the first or second aspect. In the wire harness according to the third aspect, the first shield member is a metal pipe.

In the wire harness according to the first to third aspects, three power cables conducting symmetrical three-phase alternating current electricity are individually surrounded by three first shield members. These first shield members are members which are not electrically connected to the second shield member and the reference potential body, and are fine conductive members such as metal pipes. Therefore, the first shield member does not function as an electrostatic shield but shields high frequency electromagnetic waves. Also, although the first shield member generates a little heat because it consumes high frequency electromagnetic waves as an eddy current, it does not cause excessive heat generation due to electromagnetic induction because it is not grounded.

On the other hand, the second shield member grounded at both ends performs the functions of an electrostatic shield and a magnetic shield. Here, the second shield member, which is a coarse conductive member, can not shield electromagnetic waves of short wavelength, that is, high frequency. However, as described above, high frequency electromagnetic waves are shielded by the first shield member. Further, in the second shield member that collectively encloses the three power cables conducting the symmetrical three-phase alternating current, the three-phase electricitys of different phases generated by the electromagnetic induction are mixed and mutually cancel each other. Therefore, the flow of an excessive induced current to the second shield member is prevented.

Also, each first shield member is relatively thin and light, and the second shield member, which is a coarse conductive member, is also relatively light. Therefore, the inconvenience of having to handle a heavy and large shield member does not occur.

From the above, according to the wire harnesses according to the first to third aspects, noise electromagnetic waves generated in the power cable for conducting symmetrical three-phase alternating current are effectively shielded, and a heavy and large shield member is adopted. It is possible to prevent an excessive induced current from flowing in the shield member without doing so.

In the second aspect, since the first shield member having high electrical conductivity is likely to cause eddy current due to high frequency electromagnetic waves, high frequency noise can be shielded more effectively. Moreover, the performance of the magnetic shield by the second shield member is enhanced by adopting the second shield member made of a magnetic material.

Further, according to the third aspect, since the first shield member is a metal pipe with a high density of conductors, high frequency noise can be shielded more effectively.

It is a top view of wire harness 10 concerning an embodiment of the present invention. FIG. 8 is an exploded perspective view of a portion of the holding member in the wire harness 10; It is a sectional view of the 2nd shield member with which wire harness 10 is provided. It is a top view of the wire harness 10 laid by the vehicle. FIG. 7 is a rear view of an end of the wire harness 10 fixed to a housing. FIG. 2 is a schematic view of a basic structure of a wire harness 10;

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The following embodiment is an example embodying the present invention, and is not an example limiting the technical scope of the present invention.

<Schematic configuration>
First, a schematic configuration of a wire harness 10 according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the wire harness 10 includes at least three power cables 9, at least three first shield members 1 and one second shield member 2. Furthermore, the wire harness 10 also includes at least one clamping member 3.

<Power cable>
The power cable 9 is an insulated wire constituted of a core wire 91 made of a conductive material and an insulation coating 92 made of an insulating material covering the periphery of the core wire 91. For example, the terminal fitting 8 is connected to the core wire 91 at the end of the power cable 9. In the example shown in FIGS. 1 and 2, the wire harness 10 includes three power cables 9 arranged in parallel. However, it is also conceivable that the wire harness 10 includes two or more sets of three power cables 9.

It is also conceivable that the wire harness 10 further includes a cable holding member for holding the ends of the three power cables 9 in a fixed positional relationship. In this case, the cable holding member holds the ends of the three power cables 9 arranged in parallel in a fixed positional relationship, and electrically insulates the three power cables 9 from each other. For example, it is conceivable that the cable holding member is a nonconductive synthetic resin member. In this case, it is conceivable that the cable holding member is a member formed by insert molding using the plurality of power cables 9 as insert members.

<First shield member>
The first shield members 1 are conductive members arranged in parallel at intervals, and individually surrounding the power cables 9. Accordingly, the wire harness 10 includes the same number of first shield members 1 as the number of power cables 9. In the example shown in FIGS. 1 and 2, the wire harness 10 includes three first shield members 1 arranged in parallel. However, it is also conceivable that the wire harness 10 includes two or more sets of three first shield members 1 according to the number of power cables 9.

The first shield member 1 is a conductive member finer in diameter than the second shield member 2 described later, that is, a member having a high ratio of the volume of the conductor to the entire volume including the gap between the conductors. In other words, the first shield member 1 is a member in which the ratio of the volume of the gap between the conductors to the entire volume is smaller than that of the second shield member 2. In addition, that the ratio of the volume of the clearance gap between conductors is small also includes that the ratio of the volume of the clearance gap between conductors is zero.

For example, it is conceivable that the first shield member 1 is a metal pipe member surrounding the power cable 9. In this case, it is conceivable that the pipe member is made of, for example, a metal-based material such as copper, stainless steel, or aluminum. It is conceivable that a plated layer or a layer of paint is formed on the surface of the pipe member as required.

Moreover, it is also conceivable that the first shield member 1 is a braided wire formed of a cylindrically woven metal wire. In this case, it is conceivable that the braided wire is made of a wire mainly composed of a metal such as copper, stainless steel or aluminum. However, in the case where the first shield member 1 is a braided wire, the metal wire forming the braided wire is braided with as fine an eye as possible, that is, it is braided such that the gap is as small as possible. desirable.

In addition, the 1st shield member 1 is electrically insulated with respect to the 2nd shield member 2 so that it may mention later. Furthermore, in a state in which the wire harness 10 is laid in the vehicle, the first shield member 1 is not electrically connected to the reference potential body such as the body of the vehicle.

<Nipping member>
The holding member 3 holds the three first shield members 1 collectively and holds the three first shield members 1 in a state of being electrically insulated and arranged in parallel at intervals. The holding members 3 are attached to at least one intermediate portion between both ends in the longitudinal direction of the three first shield members 1.

The holding member 3 is a non-conductive member, and is, for example, a molded member of synthetic resin. In this case, the holding member 3 is made of a material such as polypropylene (PP), polyethylene (PE), polyvinyl chloride (PVC), polyethylene terephthalate (PET), or polyamide (PA).

As shown in FIG. 2, the holding member 3 is configured of a first holding member 3 a and a second holding member 3 b which are combined with the three first shield members 1 interposed therebetween. Further, three grooves 31 are formed in each of the first holding member 3a and the second holding member 3b.

The groove portion 31 is a groove-shaped portion in which each of the three first shield members 1 surrounding the periphery of each of the three power cables 9 is fitted. Each of the first shield members 1 is sandwiched between the groove 31 of the first holding member 3a and the groove 31 of the second holding member 3b facing each other. As a result, the three first shield members 1 through which the power cables 9 pass are held spaced apart and arranged in parallel and electrically isolated from each other.

Moreover, the 1st clamping member 3a and the 2nd clamping member 3b are connected by the coupler in the state which pinched | interposed the three 1st shield members 1 located in a line at intervals. Thereby, the 1st clamping member 3a and the 2nd clamping member 3b are hold | maintained in the combined state.

In the example shown in FIG. 2, the connector is a screw 51 and a nut 52. Therefore, in the first holding member 3a and the second holding member 3b shown in FIG. 2, screw holes 32 through which connection screws 51 are formed are formed.

In the example shown in FIGS. 1 and 2, the holding members 3 are attached to both ends of the three first shield members 1 arranged in parallel and at least one intermediate portion between the ends.

<Second shield member>
The second shield member 2 is a conductive member that collectively surrounds the three first shield members 1 in a state of being electrically insulated from the three first shield members 1. Further, the second shield member 2 is a conductive member that is coarser than the first shield member 1, that is, a member having a low ratio of the volume of the conductor to the entire volume including the gap between the conductors. In other words, the second shield member 2 is a member in which the ratio of the volume of the gap between the conductors to the entire volume is larger than that of the first shield member 1.

For example, it is conceivable that the second shield member 2 is a metal cloth which is a woven fabric of metal threads. In this case, the metal cloth is formed in a tubular shape by being wound around the three first shield members 1 individually surrounding each of the three power cables 9.

The metal cloth is, for example, a cloth having a mesh structure in which yarns of a metal containing copper as a main component cross in a longitudinal direction and a transverse direction. Moreover, the metal cloth may have a structure in which a flexible film made of a resin material is attached to a metal yarn cloth. A gap is formed between metal threads (conductors) in the metal cloth. The metal thread forming the metal cloth is, for example, mainly composed of a metal such as iron, copper, stainless steel or aluminum.

Moreover, it is also considered that the 2nd shield member 2 is a braided wire comprised with the wire of the metal braided cylindrically. In this case, it is conceivable that the braided wire is made of a wire mainly composed of a metal such as iron, copper, stainless steel or aluminum. When the second shield member 2 is a braided wire, it is conceivable that the metal wire forming the braided wire is braided with a relatively coarse mesh, that is, braided so as to increase the gap. . The second shield member 2 made of a braided wire or metal cloth has conductivity and flexibility.

In addition, it is also conceivable that the second shield member 2 is formed of a thin metal plate which is formed into a tubular shape, in which a plurality of holes or a plurality of slits are formed.

Further, as shown in FIG. 3, it is conceivable that the second shield member 2 is integrally formed with the insulating sheet 20 which electrically insulates the second shield member 2 from the first shield member 1. . In the example shown in FIG. 3, an insulating sheet 20 made of a conductive material is adhered to the inner side surface of the second shield member 2. The insulating sheet 20 is, for example, a sheet-like member made of a nonconductive synthetic resin mainly composed of polyethylene terephthalate (PET) or polycarbonate (PC). It is also conceivable that the insulating sheet 20 is not adhered to the second shield member 2.

Further, as shown in FIGS. 1 and 2, the second shield member 2 has grounded portions 21 electrically connected to the reference potential body 70 at both ends in the longitudinal direction. The reference potential body 70 is, for example, a body of a metal vehicle.

In the wire harness 10, the first shield member 1 is preferably made of a material having a higher electrical conductivity than the second shield member 2. For example, it is conceivable that the first shield member 1 is a metal whose main component is copper or the like having a high electrical conductivity. Furthermore, it is conceivable that the second shield member 2 is made of a magnetic material such as iron.

<Example of grounding structure of second shield member>
For example, as shown in FIG. 4, in the state where the wire harness 10 is laid in a vehicle, both ends of the power cable 9 enter the case 7 from the opening of the metal case 7 that accommodates the device of the connection partner. Wired.

Furthermore, the two grounded portions 21 in the second shield member 2 are electrically connected to the reference potential body 70 via, for example, the metal bracket member 4 and the metal housing 7.

In the example shown in FIGS. 4 and 5, the grounded portion 21 of the second shield member 2 is placed on the outside of the sandwiching members 3 provided at the end portions of the three first shield members 1.

The bracket member 4 also has a frame portion 41 and a flange portion 42. The frame portion 41 of the bracket member 4 is a portion which is further covered on the outside of the grounded portion 21 which is covered on the holding member 3. The frame portion 41 is fixed to the frame portion 41 of the bracket member 4 in a state of being in close contact with the grounded portion 21 of the second shield member 2 placed on the holding member 3 by being tightened by, for example, the caulking metal fitting 40 . The flange portion 42 of the bracket member 4 is a portion fixed to the edge of the opening for introducing the power cable 9 in the housing 7 by a screw or the like.

The grounded portion 21 of the second shield member 2 is sandwiched between the holding member 3 on the inner side and the frame portion 41 of the bracket member 4 on the outer side by the structure shown in FIGS. Connected. Further, the bracket member 4 is electrically connected to the housing 7 by fixing its flange portion 42 to the housing 7. Further, the housing 7 is electrically connected to a reference potential body 70 such as a vehicle body.

With the structure shown in FIGS. 4 and 5, the grounded portion 21 of the second shield member 2 is electrically connected to the reference potential body 70 via the bracket member 4 and the housing 7. Therefore, the second shield member 2 and the reference potential body 70 form an electrical closed loop with other conductive members such as the housing 7.

In the example shown in FIGS. 4 and 5, the grounded portion 21 of the second shield member 2 and the housing 7 are connected by the bracket member 4 and the caulking metal fitting 40. However, it is also considered that the grounded portion 21 and the housing 7 are connected by a structure different from the example shown in FIGS.

FIG. 6 is a schematic view of the basic structure of the wire harness 10. The three power cables 9 for conducting symmetrical three-phase alternating current are individually surrounded by three first shield members 1 arranged in parallel at intervals. The three first shield members 1 are not grounded. Also, one second shield member 2 is a conductive member that is coarser than the first shield member 1. The second shield members 2 collectively surround the three first shield members 1 in a state of being electrically insulated from the three first shield members 1. Further, the second shield member 2 has grounded portions 21 electrically connected to the reference potential body 70 at both ends thereof. Therefore, the second shield member 2 and the reference potential body 70 form an electrical closed loop together with the bracket member 4 and the housing 7.

<Effect>
In the wire harness 100, three power cables 9 for conducting symmetrical three-phase alternating current are individually surrounded by three first shield members 1. These first shield members 1 are members which are not electrically connected to the second shield member 2 and the reference potential body 70, and are fine conductive members such as metal pipes. Therefore, the first shield member 1 does not function as an electrostatic shield, but shields high frequency electromagnetic waves. Also, although the first shield member 1 generates a little heat because it consumes high frequency electromagnetic waves as an eddy current, it does not cause excessive heat generation due to electromagnetic induction because it is not grounded.

On the other hand, the second shield member 2 grounded at both ends performs the functions of an electrostatic shield and a magnetic shield. Here, the second shield member 2 which is a coarse conductive member can not shield an electromagnetic wave having a short wavelength, that is, an electromagnetic wave having a high frequency. However, as described above, high frequency electromagnetic waves are shielded by the first shield member 1. Further, in the second shield member 2 which collectively surrounds the three power cables 9 conducting the symmetrical three-phase alternating current, the three-phase electricitys of different phases generated by the electromagnetic induction are mixed and mutually cancel each other. . Therefore, the flow of an excessive induced current to the second shield member 2 is prevented.

Further, each of the first shield members 1 is relatively thin and light, and the second shield member 2 which is a coarse conductive member is also relatively light. Therefore, the inconvenience of having to handle a heavy and large shield member does not occur.

From the above, if the wire harness 10 is adopted, noise electromagnetic waves generated in the power cable 9 for conducting symmetrical three-phase alternating current are effectively shielded, and furthermore, a shield member without adopting a heavy and large shield member It is possible to prevent an excessive induced current from flowing in the

Further, in the wire harness 10, if the first shield member 1 is a member having a high electric conductivity such as copper, an eddy current is easily generated in the first shield member 1 due to the high frequency electromagnetic wave. Therefore, high frequency noise can be shielded more effectively by the first shield member 1. In addition, if the second shield member 2 made of a magnetic material is adopted, the performance of the magnetic shield by the second shield member 2 is enhanced.

Further, if the first shield member 1 is a metal pipe with a high density of conductors, high frequency noise can be shielded more effectively.

<Others>
In the wire harness 10, the holding member 3 is configured by a first holding member 3a and a second holding member 3b connected by a screw 51 and a nut 52. However, it is also conceivable that the first holding member 3a and the second holding member 3b have a structure that can be connected without using a connecting tool such as the screw 51. For example, it is also conceivable that the first holding member 3a and the second holding member 3b are connected by a welding or locking mechanism or the like.

In addition, it is also conceivable that the first holding member 3a and the second holding member 3b are integrally formed by having a structure in which they are connected at one end of each.

It is also conceivable that the three first shield members 1 are arranged side by side, that is, arranged in three dimensions rather than arranged in two dimensions. For example, it is also conceivable that the three first shield members 1 are arranged in parallel at the position at the apex of an equilateral triangle when viewed from their longitudinal direction.

DESCRIPTION OF SYMBOLS 1 first shield member 2 second shield member 3 sandwiching member 4 bracket member 7 housing 8 terminal fitting 9 power cable 10 wire harness 20 insulating sheet 21 grounded portion 31 groove portion 32 screw hole 40 caulking fitting 41 frame member 42 of bracket member Flange member 51 of bracket member Screw 52 Nut 70 Reference potential body 91 Core wire 92 Insulating sheath 100 Wire harness 3a First holding member 3b Second holding member

Claims

Three power cables that conduct symmetrical three-phase alternating current electricity,
Three conductive first shield members arranged in parallel spaced apart and individually surrounding the periphery of each of the three power cables;
The conductive member is coarser than the first shield member, and has grounded portions electrically connected to the reference potential body at both ends, and electrically connected to the three first shield members. And a second shield member that collectively surrounds the three first shield members in an insulated state.
A wire harness according to claim 1, wherein
The first shield member is made of a material having higher electrical conductivity than the second shield member,
A wire harness, wherein the second shield member is made of a magnetic material.
A wire harness according to claim 1 or 2, wherein
The wire harness, wherein the first shield member is a metal pipe.