WIRE HARNESS UNIT

A wire harness unit including: a plurality of conductive paths for conducting electricity between in-vehicle devices, wherein: the plurality of conductive paths include a first conductive path and a second conductive path parallel with the first conductive path, the first conductive path includes a first inner insulating layer formed in a hollow tube shape, and a first tubular conductor that covers an outer circumferential surface of the first inner insulating layer, and the second conductive path includes a second inner insulating layer formed in a hollow tube shape, and a second tubular conductor that covers an outer circumferential surface of the second inner insulating layer.

TECHNICAL FIELD

The present disclosure relates to a wire harness unit.

BACKGROUND ART

Conventionally, wire harnesses installed in vehicles such as hybrid cars and electric cars electrically connect a plurality of electrical devices to each other. Also, in electric cars, vehicles and ground facilities are connected to each other by a wire harness, and a power storage device installed in the vehicle is charged by the ground facility. As a result of a voltage supplied through the wire harness being high, the amount of heat generated by the wire harness is increased. For this reason, configurations for cooling wire harnesses have been proposed.

For example, Patent Document 1 discloses a wire harness provided with a coated wire, an inner tube that covers the coated wire, and an outer tube that covers the inner tube with a predetermined space therebetween, in which a circulation path for a coolant is formed between the inner tube and the outer tube. The circulation path is formed by inner and outer tubes that are separate from the coated wire, and the coated wire is disposed radially inward of the circulation path.

CITATION LIST

Patent Documents

SUMMARY OF INVENTION

Problem to be Solved

Incidentally, in the wire harness disclosed in Patent Document 1, the circulation path (a path along which the coolant flows) is disposed outside the coated wire, and thus the coolant is far from the central portion of the coated wire, which is the heat source. Accordingly, there is room for improvement in terms of cooling efficiency of the coated wire.

An object of the present disclosure is to provide a wire harness unit capable of improving cooling efficiency.

Solution to Problem

A wire harness unit that is an aspect of the present disclosure includes a plurality of conductive paths for conducting electricity between in-vehicle devices, and a cooling portion for cooling the plurality of conductive paths, the plurality of conductive paths include a first conductive path and a second conductive path parallel with the first conductive path, the first conductive path includes a first inner insulating layer formed in a hollow tube shape, and a first tubular conductor that covers an outer circumferential surface of the first inner insulating layer, the second conductive path includes a second inner insulating layer formed in a hollow tube shape, and a second tubular conductor that covers an outer circumferential surface of the second inner insulating layer, and the cooling portion includes a first cooling tube constituted by the first inner insulating layer through which a coolant is able to flow, a second cooling tube constituted by the second inner insulating layer through which a coolant is able to flow, and a turnback tube that links the first cooling tube and the second cooling tube.

Advantageous Effects of Invention

According to a wire harness unit that is an aspect of the present disclosure, cooling efficiency can be improved.

DESCRIPTION OF EMBODIMENTS

Description of Embodiments of Disclosure

First, aspects of the present disclosure will be listed and described.

[1] A wire harness unit according to the present includes a plurality of conductive paths for conducting electricity between in-vehicle devices, and a cooling portion for cooling the plurality of conductive paths, the plurality of conductive paths include a first conductive path and a second conductive path that is parallel with the first conductive path, the first conductive path includes a first inner insulating layer formed in a hollow tube shape, and a first tubular conductor that covers an outer circumferential surface of the first inner insulating layer, the second conductive path includes a second inner insulating layer formed in a hollow tube shape, and a second tubular conductor that covers an outer circumferential surface of the second inner insulating layer, and the cooling portion includes a first cooling tube constituted by the first inner insulating layer through which a coolant is able to flow, a second cooling tube constituted by the second inner insulating layer through which a coolant is able to flow, and a turnback tube that links the first cooling tube and the second cooling tube.

According to this configuration, a coolant can flow through the first cooling tube constituted by the first inner insulating layer that is covered by the first tubular conductor, and the second cooling tube constituted by the second inner insulating layer that is covered by the second tubular conductor. For this reason, the first tubular conductor and the second tubular conductor can be cooled from the inside, thereby making it possible to improve cooling efficiency. Moreover, since the cooling portion includes the turnback tube that links the first cooling tube constituted by the first inner insulating layer and the second cooling tube constituted by the second inner insulating layer, it is possible to reduce the number of inlets and outlets for the coolant and simplify the structure for connection to a pump, for example, compared with a case where the cooling tube does not include the turnback tube.

[2] It is preferable that the number of conductive paths included in the plurality of conductive paths is an even number.

According to this configuration, since the number of conductive paths included in the plurality of conductive paths is an even number, the inlet and the outlet for the coolant can be easily positioned close to each other. That is to say, a situation is avoided where the positions of the inlet and the outlet for the coolant are spaced far apart from each other when, for example, the number of conductive paths is three, which is an odd number, and the cooling portion further includes a third cooling tube constituted by a third inner insulating layer of a third conductive path, and a turnback tube that links the second cooling tube and the third cooling tube. Thus, it is possible to easily set the positions of the inlet and the outlet for the coolant close to each other, and to reduce a routing space and the like for connection to a pump, for example.

[3] It is preferable that the wire harness unit further includes an exterior member for covering the conductive paths, the exterior member includes a tubular exterior member and a grommet that is connected to an end portion of the tubular exterior member, and the turnback tube is disposed inside the grommet.

According to this configuration, since the turnback tube is disposed inside the grommet, it is possible to easily house the turnback tube, for example. Even in a case where, for example, the turnback tube is configured such that it cannot be sharply bent, and a large space is required, such a case can be easily addressed without increasing the entire size of the tubular exterior member. Moreover, for example, if the grommet is shaped such that the size thereof increases toward a member that is connected to the grommet, the turnback tube can be easily housed in a large space.

[4] It is preferable that the turnback tube is separate from the first cooling tube and the second cooling tube.

According to this configuration, since the turnback tube is separate from the first cooling tube and the second cooling tube, it is easy to manufacture the wire harness unit compared with a case where the turnback tube is integrated with the first cooling tube and the second cooling tube, for example.

[5] It is preferable that the turnback tube is integrated with the first cooling tube and the second cooling tube.

According to this configuration, since the turnback tube is integrated with the first cooling tube and the second cooling tube, the number of components is small compared with a case where the turnback tube is separate from the first cooling tube and the second cooling tube, for example.

[6] It is preferable that the first tubular conductor is a first braided member formed by braiding metal strands, and the second tubular conductor is a second braided member formed by braiding metal strands.

According to this configuration, the first tubular conductor is a first braided member formed by braiding metal strands, the second tubular conductor is a second braided member formed by braiding metal strands, both of the first tubular conductor and the second tubular conductor are flexible, and thus, dimensional tolerance of the conductive paths can be absorbed.

Further, this configuration is a counter measure against swinging generated while a vehicle is travelling.

[7] It is preferable that the wire harness unit further includes an electromagnetic shield member for covering the conductive paths, the electromagnetic shield member is a shielding braided member formed by braiding metal strands, the first inner insulating layer and the second inner insulating layer each include an exposed insulating portion that is exposed from the first tubular conductor or the second tubular conductor, and the exposed insulating portion extends through the shielding braided member.

According to this configuration, both the shielding properties for suppressing electromagnetic noise radiation from the conductive paths and an improvement in the ease of assembly of the cooling portion can be achieved.

[8] It is preferable that the first conductive path and the second conductive path each include a terminal and an outer insulating layer that covers an outer circumferential surface of the first tubular conductor or the second tubular conductor, the first tubular conductor and the second tubular conductor include an exposed conductor portion exposed from the outer insulating layer, the exposed conductor portion is electrically connected to the terminal, and the exposed conductor portion is covered by the electromagnetic shield member.

According to this configuration, both the shielding properties for suppressing electromagnetic noise radiation from the conductive paths and an improvement in the ease of assembly of the cooling portion can be achieved.

[9] It is preferable that the wire harness unit further includes a coating member for covering the exposed conductor portion.

According to this configuration, it is possible to prevent the exposed conductor portions of the first tubular conductor and the second tubular conductor from coming into contact with the electromagnetic shield member.

[10] It is preferable that the wire harness unit further includes an exterior member for covering the conductive paths, the exterior member includes a tubular exterior member and a grommet connected to an end portion of the tubular exterior member, and the first inner insulating layer and the second inner insulating layer extend through the grommet.

According to this configuration, since the first inner insulating layer that is the first cooling tube, and the second inner insulating layer that is the second cooling tube extend through the grommet and are led out to the outside, a decrease in the water blocking properties of the wire harness unit can be suppressed.

Description of Embodiments of Disclosure

Specific examples of a wire harness unit according to the present disclosure will be described below with reference to the drawings. Note that, in the drawings, parts of the configurations may be shown in an exaggerated or simplified manner for convenience of description. Moreover, dimensional ratios of various portions may be different from actual dimensional ratios.

“Parallel” and “orthogonal” in the present specification include not only being exactly parallel and orthogonal but also approximately parallel and orthogonal within a range in which the operation and effects of the present embodiment can be achieved. The present invention is not limited to the embodiments disclosed herein, but is defined by the claims, and intended to include all modifications within the meaning and the scope equivalent thereof.

Overview Configuration of Wire Harness Unit10

A wire harness unit10shown inFIG.1electrically connects two in-vehicle devices installed in a vehicle V. The vehicle V is, for example, a hybrid car, an electric car, or the like. The wire harness unit10includes conductive paths11for electrically connecting an in-vehicle device M1and an in-vehicle device M2, and an exterior member60for covering the conductive paths11. The conductive paths11are routed, for example, from the in-vehicle device M1to the in-vehicle device M2so that portions thereof in a lengthwise direction pass under the floor of the vehicle V. With regard to examples of the in-vehicle device M1and the in-vehicle device M2, the in-vehicle device M1is an inverter installed toward the front side of the vehicle V, and the in-vehicle device M2is a high-voltage battery installed on the rear side of the vehicle V relative to the in-vehicle device M1. The in-vehicle device M1serving as an inverter is connected to a motor (not shown) for driving the wheels serving as a motive power source for causing the vehicle to travel, for example. The inverter generates AC power from DC power from the high-voltage battery, and supplies the AC power to the motor. The in-vehicle device M2, which is a high-voltage battery, is a battery capable of supplying a voltage of at least 100 V, for example. In other words, the conductive paths11of the present embodiment constitute a high-voltage circuit that enables high-voltage exchange between the high-voltage battery and the inverter.

Detailed Configuration of Wire Harness Unit10

As shown inFIGS.2,3, and4, the wire harness unit10includes a plurality of conductive paths11, a turnback tube40, an electromagnetic shield member50, the exterior member60, and connectors71and72. As shown inFIGS.4and6, the plurality of conductive paths11include a first conductive path20and a second conductive path30that is parallel with the first conductive path20.

As shown inFIGS.3to6, the first conductive path20includes a first tubular conductor21, a first inner insulating layer22, an outer insulating layer23, and terminals25and26.

The first tubular conductor21is conductive and has a hollow structure. The first tubular conductor21is a first braided member formed by braiding metal strands, for example. A plating layer of tin or the like may be formed on the surfaces of the metal strands. The material for the first tubular conductor21is a metal material such as a copper-based material or an aluminum-based material. The first tubular conductor21is formed in a shape conforming to a routing path of the wire harness unit10shown inFIG.1. The first tubular conductor21is bent using a pipe bender (in other words, a pipe bending device).

FIG.4is a cross-sectional view of the wire harness unit10taken along a plane orthogonal to the lengthwise direction of the wire harness unit10. InFIG.4, the lengthwise direction of the first tubular conductor21is the front-back direction of the sheet plane ofFIG.4. The cross-sectional shape of the first tubular conductor21taken along a plane that is vertical to the lengthwise direction of the first tubular conductor21, that is, a direction in which the first tubular conductor21extends and that is the axial direction of the first tubular conductor21(i.e., a lateral cross-sectional shape) is annular, for example. Note that the cross sectional shape of the first tubular conductor21can be any shape. Also, with respect to the cross sectional shape of the first tubular conductor21, the shapes of the outer circumference and the inner circumference may be different from each other. Also, cross sectional shapes of the first tubular conductor21in the lengthwise direction may be different from each other.

The first inner insulating layer22has a hollow structure, and is flexible. Also, the first inner insulating layer22is insulative. The outer circumferential surface of the first inner insulating layer22is covered by the first tubular conductor21. The first inner insulating layer22is constituted by an insulating material such as a synthetic resin. Examples of the material for the first inner insulating layer22include a silicone resin, a synthetic resin whose main component is a polyolefin resin such as cross-linked polyethylene or cross-linked polypropylene, and the like. A single kind of material, or two or more kinds of materials can be used in combination as appropriate, for the first inner insulating layer22. The first inner insulating layer22can be formed by performing extrusion molding (extrusion coating) on the first tubular conductor21, for example.

The outer insulating layer23covers the entirety of the outer circumferential surface of the first tubular conductor21in the circumferential direction, for example. The outer insulating layer23is flexible. Also, the outer insulating layer23is insulative. The outer insulating layer23is constituted by an insulating material such as a synthetic resin. Examples of the material for the outer insulating layer23include a silicone resin, a synthetic resin whose main component is a polyolefin resin such as cross-linked polyethylene or cross-linked polypropylene, and the like. A single kind of material, or two or more kinds of materials can be used in combination as appropriate, for the outer insulating layer23. The outer insulating layer23can be formed by performing extrusion molding (extrusion coating) on the first tubular conductor21, for example.

As shown inFIG.3, the first inner insulating layer22includes exposed insulating portions22aand22bexposed from the first tubular conductor21, at the two ends in the lengthwise direction of the first inner insulating layer22.

As shown inFIG.3, the first tubular conductor21includes exposed conductor portions21aand21bthat are exposed from the outer insulating layer23, at the two ends in the lengthwise direction of the first tubular conductor21.

As shown inFIG.3, the exposed conductor portion21aextends to the connector71. The exposed conductor portion21bextends to the connector72.

FIG.5is an illustrative diagram showing connection between the first tubular conductor and the terminals. Note that, inFIG.5, the members of the first conductive path20shown on the left side ofFIGS.2and3are indicated by reference signs without parentheses, and the members shown on the right side ofFIGS.2and3are indicated by reference signs in parentheses.

The terminal25is held by the connector71shown inFIGS.1and2, and connected to the in-vehicle device M1. The terminal25is connected to a leading end of the exposed conductor portion21aof the first tubular conductor21. For example, the terminal25includes a pair of crimping pieces, with which the terminal25is crimped to the leading end of the exposed conductor portion21a. The terminal26is held by the connector72shown inFIGS.1and2, and connected to the in-vehicle device M2. The terminal26is connected to a leading end of the exposed conductor portion21bof the first tubular conductor21. For example, the terminal26includes a pair of crimping pieces, with which the terminal26is crimped to the leading end of the exposed conductor portion21b.

In addition, the second conductive path30includes a second tubular conductor31, a second inner insulating layer32, an outer insulating layer33, and terminals25and26. As shown inFIGS.4and6, the second conductive path30is parallel with the first conductive path20. The second conductive path30is configured in a similar manner to the first conductive path20, and, for example, the second tubular conductor31is a second braided member formed by braiding metal strands similarly to the first tubular conductor21, for example, and is a component having the same model number as the first tubular conductor21. Also, the second inner insulating layer32is configured in a similar manner to the first inner insulating layer22, and includes exposed insulating portions32aand32bthat are exposed from the second tubular conductor31, at the two ends in the lengthwise direction of the second inner insulating layer32. In this manner, similar names and reference numerals are given to the constituent components of the second conductive path30that are similar to the constituent components of the first conductive path20, and a detailed description thereof is omitted.

The first inner insulating layer22constitutes the first cooling tube through which a coolant73can flow. The second inner insulating layer32constitutes the second cooling tube through which the coolant73can flow. The turnback tube40links the first inner insulating layer22constituting the first cooling tube and the second inner insulating layer32constituting the second cooling tube. Specifically, as shown inFIG.6, the turnback tube40is formed to be folded so as to link an end portion of the exposed insulating portion22aof the first inner insulating layer22and an end portion of the exposed insulating portion32aof the second inner insulating layer32. The material for the turnback tube40is a flexible resin material such as PP (polypropylene), PVC (polyvinyl chloride), or cross-linked PE (polyethylene resin).

The first inner insulating layer22, the second inner insulating layer32, and the turnback tube40constitute a cooling portion, and the coolant73is supplied to the inside of the first inner insulating layer22, the second inner insulating layer32, and the turnback tube40. The coolant73may be a liquid such as water and an antifreeze solution, or a fluid such as a gas, or an air-liquid two-phase flow in which a gas and a liquid are mixed. The coolant73is supplied by a pump (not shown). The first inner insulating layer22, the second inner insulating layer32, and the turnback tube40form a part of a circulation path through which the coolant73is circulated. The circulation path includes the above-described pump and a heat dissipating portion, for example. The pump pressurizes and feeds the coolant73to the first inner insulating layer22, and pressurizes and feeds the coolant73to the second inner insulating layer32via the turnback tube40. The coolant73supplied to the first inner insulating layer22and the second inner insulating layer32performs heat exchange with the first tubular conductor21and the second tubular conductor31that cover outer circumferential surfaces22cand32cof the first inner insulating layer22and the second inner insulating layer32, respectively. The heat dissipating portion cools the coolant73by dissipating heat from the coolant73, of which the temperature has risen due to heat exchange, to the outside. The cooled coolant73is pressurized and fed again to the first inner insulating layer22by the pump. The first inner insulating layer22, the second inner insulating layer32, and the turnback tube40constitute a cooling portion for cooling the first tubular conductor21and the second tubular conductor31using the coolant73circulated in this manner.

As shown inFIGS.3and4, the electromagnetic shield member50covers two conductive paths11. The electromagnetic shield member50is a shielding braided member formed by braiding metal strands into a tubular shape. The electromagnetic shield member50has shielding properties. Also, the electromagnetic shield member50is flexible. As shown inFIG.3, one end of the electromagnetic shield member50is connected to the connector71, and the other end of the electromagnetic shield member50is connected to the connector72. Accordingly, the electromagnetic shield member50covers the entire length of the conductive paths11that transmit a high voltage. In this manner, the radiation of electromagnetic noise originating from the conductive paths11to the outside is suppressed.

The exterior member60covers the conductive paths11and the electromagnetic shield member50. The exterior member60includes a tubular exterior member61, and grommets62and63respectively connected to a first end portion61aand a second end portion61bof the tubular exterior member61.

The tubular exterior member61covers portions of the outer circumferences of the first tubular conductor21and the second tubular conductor31in the lengthwise direction, for example. The tubular exterior member61is formed in a tubular shape in which the two ends thereof in the lengthwise direction of the first tubular conductor21and the second tubular conductor31are open, for example. The tubular exterior member61surrounds the entirety of the outer circumferences of the first tubular conductor21and the second tubular conductor31in the circumferential direction, for example. The tubular exterior member61of the present embodiment is formed in a cylindrical shape. The tubular exterior member61has a bellows structure in which, for example, annular protruding portions and annular recessed portions are alternately arranged along the axis direction (lengthwise direction) thereof in which the central axial line of the tubular exterior member61extends. Examples of the material for the tubular exterior member61include a conductive resin material and a non-conductive resin material. Examples of the resin material include a synthetic resin such as polyolefin, polyamide, polyester, and ABS resin. The tubular exterior member61of the present embodiment is a corrugated tube made of a synthetic resin.

The grommet62is formed in a substantially tubular shape. The grommet62is made of rubber, for example. The grommet62spans between the connector71and the tubular exterior member61. The grommet62is fastened and fixed to the outer surface of the connector71by a fastening band64aso as to be in close contact therewith. Also, the grommet62is fastened and fixed to the outer side of the first end portion61aof the tubular exterior member61by a fastening band64bso as to be in close contact therewith. As shown inFIG.3, the turnback tube40is disposed inside the grommet62.

The grommet63is formed in a substantially tubular shape. The grommet63is made of rubber, for example. The grommet63spans between the connector72and the tubular exterior member61. The grommet63is fastened and fixed to the outer surface of the connector72by a fastening band65aso as to be in close contact therewith. Also, the grommet63is fastened and fixed to the outer side of the second end portion61bof the tubular exterior member61by a fastening band65bso as to be in close contact therewith. Through holes63aextending through the grommet63are formed in the grommet63. The through holes63abring the inside and the outside of the grommet63into communication.

In the present embodiment, two through holes63aare formed in the grommet63, and the exposed insulating portion22bof the first inner insulating layer22constituting the inlet is inserted into one through hole63a, and the exposed insulating portion32bof the second inner insulating layer32constituting the outlet is inserted into the other through hole63a. The through holes63aare formed so as to be in intimate contact with the outer circumferential surfaces of the exposed insulating portions22band32bthat are respectively inserted into the through holes63a. The exposed insulating portions22band32bof the first inner insulating layer22and the second inner insulating layer32extend through the electromagnetic shield member50, and are led from the through holes63aof the grommet63to the outside of the grommet63.

Operation

Next, operation of the wire harness unit10of the present embodiment will be described.

The wire harness unit10includes the conductive paths11for conducting electricity between the in-vehicle devices M1and M2, and a cooling portion for cooling the conductive paths11. The first conductive path includes the first tubular conductor21that is conductive and hollow, and the first inner insulating layer22that is covered by the first tubular conductor21. The second conductive path30includes the second tubular conductor31that is conductive and hollow, and the second inner insulating layer32that is covered by the second tubular conductor31. The first inner insulating layer22is a first cooling tube that constitutes a portion of the cooling portion, and through which a coolant can flow. The second inner insulating layer32is a second cooling tube that constitutes a portion of the cooling portion, and through which a coolant can flow. Also, the cooling portion includes the turnback tube40that links the first cooling tube and the second cooling tube.

The coolant73is supplied to the first inner insulating layer22. At this time, the coolant73flows through the first inner insulating layer22, the turnback tube40, and the second inner insulating layer32in the stated order. The first inner insulating layer22is covered by the first tubular conductor21. Thus, the first inner insulating layer22allows the coolant73to flow inside the first tubular conductor21. For this reason, the first tubular conductor21is cooled through heat exchange between the first tubular conductor21and the coolant73flowing on the inner side of the first inner insulating layer22. The second inner insulating layer32is covered by the second tubular conductor31. Thus, the second inner insulating layer32allows the coolant73to flow inside the second tubular conductor31. For this reason, the second tubular conductor31is cooled through heat exchange between the second tubular conductor31and the coolant73flowing on the inner side of the second inner insulating layer32. In this manner, the first tubular conductor21and the second tubular conductor31can be cooled from the inside.

Compared to a braided wire formed by twisting together a plurality of metal strands having the same cross sectional area and a single core wire having a solid structure, the first tubular conductor21and the second tubular conductor31have a larger outer circumference. In other words, the first tubular conductor21and the second tubular conductor31have a larger area on the outer circumferential side compared to a braided wire and a single core wire. Accordingly, since heat can be dissipated outward from a larger area, heat dissipation properties can be improved.

The first tubular conductor21of the first conductive path20is a first braided member formed by braiding metal strands, and includes the exposed conductor portions21aand21bthat are exposed from the outer insulating layer23. Leading ends of the exposed conductor portions21aand21bare respectively connected to the terminals25and26fixed to the connectors71and72. The exposed conductor portions21aand21bare more flexible than the outer insulating layer23. Accordingly, dimensional tolerance of the first conductive path20can be absorbed. Also, when the vehicle V vibrates, positional deviation between the parts due to the vibration can be absorbed. Accordingly, loads applied to the connectors71and72and the terminals25and26can be reduced. In addition, the second conductive path30has a configuration similar to the first conductive path20, and thus has similar operation and effects.

The electromagnetic shield member50covers the two conductive paths11. The electromagnetic shield member50is a shielding braided member formed by braiding metal strands into a tubular shape. For this reason, it is possible to suppress electromagnetic noise radiation from the conductive paths11to the outside. In addition, for this reason, the exposed insulating portions22band32bcan be led out from the electromagnetic shield member50, at an intermediate portion of the electromagnetic shield member50. Accordingly, the exposed insulating portions22band32bcan be easily led to the outside of the wire harness unit10, and constituent members for circulating the coolant73can be easily connected to the first inner insulating layer22and the second inner insulating layer32.

The wire harness unit10includes the exterior member60for covering the conductive paths11. The exterior member60includes a tubular exterior member61, and grommets62and63respectively connected to a first end portion61aand a second end portion61bof the tubular exterior member61. The exposed insulating portions22band32bof the first inner insulating layer22and the second inner insulating layer32extend through the grommet63. In this manner, since the exposed insulating portions22band32bof the first inner insulating layer22and the second inner insulating layer32extend through the grommet63so as to be led to the outside of the wire harness unit10, degradation of the water blocking properties of the wire harness unit10can be suppressed.

As described above, according to the present embodiment, the following effects are achieved.

(1) The coolant73can flow inside the first cooling tube constituted by the first inner insulating layer22that is covered by the first tubular conductor21, and the second cooling tube constituted by the second inner insulating layer32that is covered by the second tubular conductor31. For this reason, the first tubular conductor21and the second tubular conductor31can be cooled from the inside, making it possible to improve cooling efficiency. Moreover, the cooling portion includes the turnback tube40that links the first cooling tube constituted by the first inner insulating layer22and the second cooling tube constituted by the second inner insulating layer32, and thus, for example, compared with a case where the cooling portion does not include the turnback tube40, it is possible to reduce the number of inlets and outlets for the coolant73, and to simplify the connection structure for connection to a pump.

(2) The plurality of conductive paths11include the first conductive path20and the second conductive path30. The number of conductive paths included in the plurality of conductive paths11is an even number, and thus the inlet and the outlet for the coolant73, specifically, the exposed insulating portion22bof the first inner insulating layer22constituting the inlet and the exposed insulating portion32bof the second inner insulating layer32constituting the outlet can be naturally positioned on the same side, and the inlet and the outlet for the coolant can be easily positioned close to each other. That is to say, a situation is avoided where the positions of the inlet and the outlet for the coolant73are spaced far apart from each other when, for example, the number of conductive paths11is three, which is an odd number, and the cooling portion further includes a third cooling tube constituted by a third inner insulating layer of a third conductive path, and a turnback tube that links the second cooling tube and the third cooling tube. Thus, for example, it is possible to easily set the positions of the exposed insulating portion22bof the first inner insulating layer22constituting the inlet and the exposed insulating portion32bof the second inner insulating layer32constituting the outlet close to each other, and to reduce a routing space and the like for connection to a pump, for example.

(3) The turnback tube40is disposed inside the grommet62, and thus, for example, the turnback tube40can be easily housed. Even in a case where, for example, the turnback tube40is configured such that it cannot be sharply bent, and a large space is required, such a case can be easily addressed without increasing the entire size of the tubular exterior member61. Moreover, for example, if the grommet62is shaped such that the size thereof increases toward a member that is connected thereto, the turnback tube40can be easily housed in a large space.

(4) Since the turnback tube40is separate from the first cooling tube constituted by the first inner insulating layer22and the second cooling tube constituted by the second inner insulating layer32, it is easy to manufacture the wire harness unit, for example, compared with a case where the turnback tube40is integrated with the first cooling tube and the second cooling tube. That is to say, a situation can be avoided where a manufacturing process for members that include the first tubular conductor21, the second tubular conductor31, and the like is complicated when all of the first inner insulating layer22, the second inner insulating layer32, and the turnback tube40are configured to be integrated, making it easy to manufacture the wire harness unit.

(5) The first tubular conductor21is a first braided member formed by braiding metal strands, and the second tubular conductor31is a second braided member formed by braiding metal strands, and the first tubular conductor21and the second tubular conductor31are flexible, thus making it possible to absorb dimensional tolerance of the conductive paths11. Further, this configuration is a counter measure against swinging generated while a vehicle is travelling.

(6) The electromagnetic shield member50is a shielding braided member formed by braiding metal strands, and the exposed insulating portion22bof the first inner insulating layer22constituting the inlet and the exposed insulating portion32bof the second inner insulating layer32constituting the outlet extend through the shielding braided member, and thus both the shielding properties for suppressing radiation of electromagnetic noise originating from the conductive paths11to the outside and an improvement in the ease of assembly of the cooling portion can be achieved.

(7) Since the first inner insulating layer22that is the first cooling tube, and the second inner insulating layer32that is the second cooling tube extend through the grommet63so as to be led to the outside, degradation of the water blocking properties of the wire harness unit10can be suppressed.

Variations

The present embodiment can be modified and implemented as follows. The present embodiment and the variations below may be implemented in combination with each other as long as no technical contradictions arise.In the above embodiment, the number of conductive paths included in the plurality of conductive paths11is an even number, but there is no limitation thereto, and the number of conductive paths may be an odd number of three or more, or may be an even number of four or more. A configuration may be adopted in which, for example, the number of conductive paths11is three, and the cooling portion further includes a third cooling tube constituted by a third inner insulating layer of a third conductive path and a turnback tube that links the second cooling tube and the third cooling tube. Moreover, a configuration may also be adopted in which, for example, the number of conductive paths11is four, and the cooling portion further includes a third cooling tube, a turnback tube that links the second cooling tube and the third cooling tube, a fourth cooling tube constituted by a fourth inner insulating layer of a fourth conductive path, and a turnback tube that links the third cooling tube and the fourth cooling tube.In the above embodiment, the turnback tube40is configured to be disposed inside the grommet62, but there is no limitation thereto, and the turnback tube40may be configured to be disposed at another location such as inside the tubular exterior member61.In the above embodiment, the exposed insulating portions22band32bof the first inner insulating layer22are led out from the grommet63, that is, the first inner insulating layer22and the second inner insulating layer32are passed through grommet63, but the first inner insulating layer22and the second inner insulating layer32may be led out from the connector72. By doing so, the first tubular conductor21, the second tubular conductor31, and the connector72can be cooled.The electromagnetic shield member50of the above embodiment may be a piece of metal tape or the like. An insulation layer may be provided on the inner circumferential surface of the electromagnetic shield member50.As shown inFIGS.7and8, a configuration may be adopted in which coating members81aand81bthat cover the exposed conductor portions21aand21bof the first tubular conductor21and the second tubular conductor31are provided. The coating members81aand81bare insulative, and prevent the exposed conductor portions21aand21bfrom coming into contact with the electromagnetic shield member50. The coating members81aand81bare heat-shrinkable tubes, for example. In addition, a configuration may also be adopted in which coating members82aand82bthat cover the exposed conductor portions21aand21bextending to the connectors71and72are provided. The coating members82aand82bare heat-shrinkable tubes, for example. Preferably, the coating members82aand82brespectively cover as far as the terminals25and26shown inFIG.5.As shown inFIG.9, a configuration may be adopted in which a turnback tube80is integrated with the first cooling tube constituted by the first inner insulating layer22and the second cooling tube constituted by the second inner insulating layer32. In other words, the first inner insulating layer22, the second inner insulating layer32, and the turnback tube80may be an integrally formed component. By doing so, the number of components is reduced compared with a case where they are separate.As shown inFIGS.3,5, and6, the first tubular conductor21according to an embodiment can have first and second length portions corresponding to the exposed conductor portions21aat the two ends thereof, and a third length portion spanning the entire length of the first tubular conductor21excluding the two exposed conductor portions21a, the third length portion being sandwiched between the outer insulating layer23and the first inner insulating layer22. The first and second length portions corresponding_to the exposed conductor portions21ado not need to be sandwiched between the outer insulating layer23and the first inner insulating layer22, and may be led out from the outer insulating layer23and/or the first inner insulating layer22outward in a radial direction. If the first tubular conductor21is a tube made of braided wires, the exposed conductor portion21amay be a tubular, belt-like, or linear braided wire lead formed by reducing the diameter of, transforming, or processing a tube made of braided wires that forms the first tubular conductor21. The same applies to the second tubular conductor31.As shown inFIGS.3and6, the wire harness unit10according to a preferable example can include a first metal braided conductor that is the first tubular conductor21, a second metal braided conductor that is the second tubular conductor31, a first cooling tube that is the first inner insulating layer22, a second cooling tube that is the second inner insulating layer32, the U-shaped turnback tube40that connects an opening end of the first cooling tube and an opening end of the second cooling tube to each other so as to form a cooling circuit, and the electromagnetic shield member50. The first tubular insulator and the second tubular insulator each may have a first opening end, a second opening end, and a pipe length defined by the first opening end and the second opening end. The U-shaped turnback tube40may have a tube length that is shorter than the pipe length of each of the first tubular insulator and the second tubular insulator.The first cooling tube that is the first inner insulating layer22, excluding exposed insulating portions22aand22bat the two ends thereof, may be covered by the first tubular conductor21, and the second cooling tube that is the second inner insulating layer32, excluding exposed insulating portions32aand32bat the two ends thereof, may be covered by the second tubular conductor31. The exposed insulating portion22aof the first cooling tube that is the first inner insulating layer22and the exposed insulating portion32athe second cooling tube that is the second inner insulating layer32may be covered by the electromagnetic shield member50. The U-shaped turnback tube40may be covered by the electromagnetic shield member50, but does not need to be covered by any of the first tubular conductor21, the first inner insulating layer22, the second tubular conductor31, and the second inner insulating layer32.The two ends of the outer insulating layer23of the first conductive path20and the two ends of the outer insulating layer33of the second conductive path30may be disposed side by side. One tube end portion of the first cooling tube that is the first inner insulating layer22and one tube end portion of the second cooling tube that is the second inner insulating layer32may extend through the electromagnetic shield member50in a radial direction, at a predetermined length portion that is spaced far apart from first ends of the outer insulating layers23and33that are disposed side by side, and that is close to second ends of the outer insulating layers23and33that are disposed side by side.

LIST OF REFERENCE NUMERALS