JP2008123949A - Shield conductor, and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance heat radiating performance in a shield conductor using a pipe. <P>SOLUTION: Since a filler 33 is filled in a gap between a wire 10 in a pipe 20 (tubular protecting member) and the pipe, heat generated in the wire 10 is transmitted to the pipe 20 through the filler 33, and is discharged to the open air from the peripheral surface of the pipe 20. Since the filler 33 has thermal conductivity higher than that of the air, the pipe filled with the filler 33 is excellent in heat radiating performance in comparison with one filled with no filler. The filler 33 is not independently injected in the pipe 20, but it is impregnated in metal wool 31 comprising a large number of fine metal wire materials 32 entangled with each other and is made to stay in the inside of the metal wool 31, and thereby, there is no fear that the injected filler 33 leaks to the outside of the pipe 33. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a shield conductor and a method for manufacturing the shield conductor.

  Shield conductors using non-shielded wires have a structure in which multiple non-shielded wires are shielded collectively by surrounding them with a shield member consisting of a cylindrical braided wire knitted in a mesh shape. Is considered. As a method for protecting the shield member and the electric wire in this type of shield conductor, generally, a means for surrounding the shield member with a protector made of synthetic resin is used, but there is a problem that the number of parts increases when the protector is used.

Therefore, the applicant of the present application has proposed a structure in which a non-shielded electric wire is inserted into a metal pipe as described in Patent Document 1. According to this structure, since the pipe exhibits the function of shielding the electric wire and the function of protecting the electric wire, there is an advantage that the number of parts can be reduced as compared with the shield conductor using the shield member and the protector.
JP 2004-171952 A

In shield conductors using pipes, there is an air layer between the wires and the pipe, so the heat generated in the wires when energized is blocked by the air with low thermal conductivity and is not easily transmitted to the pipes. Since the pipe does not have an external ventilation path such as a gap between stitches in the braided wire, the heat generated in the electric wire tends to be trapped inside the pipe and the heat dissipation tends to be low.
Here, the amount of heat generated when a predetermined current flows through the conductor decreases as the cross-sectional area of the conductor increases, and the temperature rise value of the conductor due to heat generation is suppressed as the heat dissipation of the conductive path increases. Therefore, in an environment where an upper limit is set for the temperature rise value of the conductor, in the case of a shield conductor with low heat dissipation efficiency as described above, it is necessary to increase the cross-sectional area of the conductor to suppress the amount of heat generation.

However, increasing the cross-sectional area of the conductor means that the shield conductor is increased in diameter and weighted, and a countermeasure is desired.
The above-mentioned problem is similarly desired to be solved in the shield conductor in a form in which the shielded electric wire is inserted into the corrugated tube.
The present invention has been completed based on the above-described circumstances, and an object thereof is to improve heat dissipation in a shield conductor.

  As means for achieving the above object, the invention of claim 1 is characterized in that an electric wire, a cylindrical protective member surrounding the electric wire, and a gap between the electric wire and the cylindrical protective member are filled and entangled with each other. It is characterized in that it is provided with a heat transfer member in a form in which a base material composed of a large number of thin wires is impregnated with a filler having a higher thermal conductivity than air.

  The invention of claim 2 is characterized in that, in the invention of claim 1, the base material is metal wool in a form in which a plurality of fine metal wires are entangled.

  The invention of claim 3 is characterized in that, in the invention of claim 1 or 2, the heat transfer member surrounds the electric wire over the entire circumference.

  The invention according to claim 4 is characterized in that, in the invention according to any one of claims 1 to 3, the heat transfer member is configured to collectively enclose a plurality of the electric wires.

  The invention of claim 5 is characterized in that, in the invention according to any one of claims 1 to 4, the heat transfer member is spirally wound around the outer periphery of the electric wire.

  The invention of claim 6 is characterized in that, in any one of claims 1 to 5, the cylindrical protection member is a metal pipe.

  The invention of claim 7 is a method of manufacturing a shield conductor in a form in which a gap between an electric wire and a cylindrical protective member surrounding the electric wire is filled with a filler having a higher thermal conductivity than air, It is characterized in that a heat transfer member in the form of impregnating the filler with a base material composed of a large number of thin wires intertwined with each other is inserted into the cylindrical protective member.

  The invention according to claim 8 is the invention according to claim 7, wherein the heat transfer member is wound around the electric wire so that the outer diameter of the heat transfer member is larger than the inner diameter of the cylindrical protective member. It is characterized in that the heat member and the electric wire are inserted into the cylindrical protective member.

<Invention of Claims 1 and 7>
Since the filler is filled in the gap between the electric wire in the cylindrical protective member, the heat generated in the electric wire is transmitted to the filler, is transmitted from the filler to the cylindrical protective member, and the cylindrical protective member Released from the outer circumference into the atmosphere. Since the filler has a higher thermal conductivity than air, the filler is superior in performance to release heat generated in the electric wire as compared with the filler not filled with the filler.
In addition, when only the filler is injected into the cylindrical protective member, there is a possibility that a part of the injected filler leaks to the outside of the cylindrical protective member. Rather than injecting into the cylindrical protective member, the base material made up of a number of thin wires intertwined with each other was impregnated so that it stays inside the base material, so that the injected filler is moved to the outside of the cylindrical protective member. There is no risk of leakage.

<Invention of Claim 2>
Since the base material into which the filler is impregnated is metal wool, it has higher thermal conductivity than that in which fabric fibers are entangled, and thus has excellent heat dissipation efficiency.

<Invention of Claim 3>
Since the heat transfer member is configured to surround the electric wire over the entire circumference, the electric wire and the heat transfer member can be inserted together into the cylindrical protective member.

<Invention of Claim 4>
Since the heat transfer member is a form that collectively encloses the plurality of electric wires, the insertion process for the cylindrical protective member can be completed in one time.

<Invention of Claim 5>
Since the heat transfer member is spirally wound around the outer periphery of the electric wire, the manufacture is easier as compared with a case where the electric wire is inserted into a cylindrical heat transfer member.

<Invention of Claim 6>
Since the cylindrical protective member is a metal pipe, the cylindrical protective member can have a shielding function, and a non-shielded electric wire can be used as the electric wire. Since the non-shielded electric wire does not have a braided wire, it has an advantage that the terminal processing is simple.

<Invention of Claim 8>
When the electric wire and the heat transfer member are inserted together into the cylindrical protective member, the heat transfer member is deformed so as to be crushed between the outer periphery of the electric wire and the inner periphery of the cylindrical protective member. There is no risk of air accumulation in the gap with the inner periphery of the protective member.

<Embodiment 1>
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. The shield conductor of the present embodiment is arranged between devices (not shown) such as a battery, an inverter, and a motor that constitute a power source for traveling in, for example, an electric vehicle, and includes three non-shields. The type of electric wire 10 is inserted into a pipe 20 (cylindrical protective member which is a constituent requirement of the present invention) having both a collective shield function and an electric wire protection function, and the gap between the outer periphery of the electric wire 10 and the inner periphery of the pipe 20 is filled. The material 33 is filled.

  The electric wire 10 has a form in which the outer periphery of a conductor 11 made of metal (for example, aluminum alloy or copper alloy) is surrounded by an insulating coating 12 made of synthetic resin, and the conductor 11 includes a plurality of thin wires (not shown). Consists of twisted wires that are close together in a spiral. The cross-sectional shape of the electric wire 10 is such that both the conductor 11 and the insulating coating 12 are perfectly circular.

  The pipe 20 is made of metal (for example, an aluminum alloy or a copper alloy) and has a higher thermal conductivity than air. The cross-sectional shape of the pipe 20 is a perfect circle like the electric wire 10 and has a straight line shape. Three electric wires 10 are inserted into the pipe 20, and both ends of the electric wire 10 are led out of the pipe 20. The three electric wires 10 in the pipe 20 are bundled so as to maintain a positional relationship that forms a generally stacked shape (a form in which a substantially equilateral triangle is drawn when the centers of the electric wires 10 are connected).

  A heat transfer member 30 is filled in the pipe 20, that is, in the gap between the pipe 20 and the electric wire 10. The heat transfer member 30 is formed by impregnating a metal wool 31 (a base material which is a constituent element of the present invention) composed of a plurality of thin metal wires 32 intertwined with each other with a filler 33 having a higher thermal conductivity than air. is there. As the filler 33, a gel-like synthetic resin having high viscosity and fluidity such as grease or silicone is used.

  The manufacturing process of the heat transfer member 30 will be described. First, the filler 33 is applied to the front and back surfaces of the long metal wool 31 formed in a strip shape. A part of the applied filler 33 moves to the inside of the metal wool 31 through the gap between the metal wires 32. At this point, the metal wool 31 is relatively elastic. When this is passed between the pair of upper and lower rollers 40, the metal wool 31 is flattened and the elasticity is suppressed a little, and the filler 33 is deeply impregnated inside the metal wool 31. There is no air pocket inside. As described above, the metal wool 31 impregnated with the filler 33 that has passed through the roller 40 becomes the belt-like heat transfer member 30. The heat transfer member 30 completed after passing through the roller 40 is wound around the reel 42 together with the separator 41.

  On the other hand, the three electric wires 10 are waiting in a bundled manner, and the belt-like heat transfer member 30 fed out from the reel 42 while being separated from the separator 41 is spirally formed with respect to the bundle of electric wires 10. Wrap it around. Accordingly, the three electric wires 10 are held in a state of being bundled together in a stack, and the three electric wires 10 are collectively surrounded by the heat transfer member 30 over the entire circumference. That is, the heat transfer member 30 wound in a spiral shape has a substantially triangular cylindrical shape as a whole. Further, the maximum outer diameter of the cylinder by the heat transfer member 30 is slightly larger than the inner diameter of the pipe 20. Furthermore, since the heat transfer member 30 adheres to the outer periphery of the electric wire 10 due to the viscosity of the filler 33, the heat transfer member 30 is kept in a cylindrical shape surrounding the bundle of the electric wires 10.

  The heat transfer member 30 and the three electric wires 10 are inserted into the pipe 20 together. At this time, the cylindrical heat transfer member 30 is pushed into the pipe 20 while being partially crushed in the radial direction, and a portion near the crushed portion moves in the circumferential direction to fill the space between the electric wires 10. At this time, since the elastic restoring force is stored in the metal wool 31 that constitutes the heat transfer member 30, the heat transfer member 30 moves inside the pipe 20 from the outer peripheral surface of the electric wire 10 and the pipe. It closely adheres to the inner peripheral surface of 20. As a result, the space between the outer periphery of the bundle of electric wires 10 and the inner periphery of the pipe 20 is filled with the heat transfer member 30, and an air pocket is generated between the outer periphery of the bundle of electric wires 10 and the inner periphery of the pipe 20. Absent. When the heat transfer member 30 and the electric wire 10 are inserted into the pipe 20, the shield conductor is completed.

  In addition, the edge part of the flexible shield member 21 which consists of a cylindrical braided wire is adhering to the outer periphery of the both ends of the pipe 20 previously. The shield member 21 is inserted so as to be peeled off from the outer periphery of the pipe 20 after the electric wire 10 and the heat transfer member 30 are inserted, and collectively surrounds the portions of the three electric wires 10 protruding to the outside of the pipe 20. By doing so, the shield function is demonstrated.

  In the conventional shield conductor, since an air layer exists between the electric wire and the pipe, the heat generated in the electric wire when energized is blocked by the air layer having a low thermal conductivity and is difficult to be transmitted to the pipe, Since the pipe does not have an external ventilation path such as a gap between stitches in the braided wire, heat generated by the electric wire tends to be trapped inside the pipe, and heat dissipation tends to be low.

  However, the shield conductor of this embodiment is filled in the pipe 20 in a state where the metal wool 31 is impregnated with the filler 33 having a higher thermal conductivity than air, and the filler 33 is connected to the outer periphery of the electric wire 10. Since the pipe 20 is in contact with the inner periphery of the pipe 20, the heat generated in the electric wire 10 is (1) transmitted from the outer periphery of the insulating coating 12 of the electric wire 10 to the filler 33, transmitted through the filler 33, and filled with the filler 33. (2) is transmitted from the outer periphery of the insulation coating 12 of the electric wire 10 to the filler 33, and is transmitted to the inner periphery of the pipe 20 through the filler 33 and the metal fine wire alternately. In this way, the air is discharged from the outer periphery of the pipe 20 into the atmosphere. Therefore, compared with what has an air layer between the outer periphery of an electric wire, and the inner periphery of a pipe, in this embodiment, it is excellent in the performance which discharge | releases the heat | fever which generate | occur | produced in the electric wire 10. FIG.

  As an effect of improving the heat dissipation performance as described above, it can be expected that the shield conductor is reduced in weight. That is, when a predetermined current is passed through the electric wire 10 (conductor 11), the smaller the cross-sectional area of the conductor 11, the greater the amount of heat generated by the electric wire 10. However, as in this embodiment, the heat dissipation is excellent. For example, even if the heat generation amount of the electric wire 10 is large, the temperature rise of the electric wire 10 can be suppressed low. Therefore, in an environment where an upper limit is set for the temperature rise value of the electric wire 10 as in an electric vehicle, the electric wire can be obtained by changing the conventional shield electric conductor Wb to the shield electric conductor of this embodiment having excellent heat dissipation. The heat generation allowable amount at 10 is relatively large. And that the heat generation allowance in the electric wire 10 is relatively large means that the minimum cross-sectional area of the conductor 11 that can be used in an environment where an upper limit is set for the temperature rise value of the electric wire 10 can be reduced. By reducing the cross-sectional area of the conductor 11, the shield conductor can be reduced in weight and diameter.

  In addition, when only the filler 33 having fluidity is injected into the pipe 20 without using the metal wool 31, there is a possibility that a part of the injected filler 33 leaks, but in this embodiment, the filler 33 is not injected into the pipe 20 alone, but impregnated in a metal wool 31 (base material) made up of a large number of thin metal wires 32 entangled with each other so that the filler 33 stays inside the metal wool 31. Therefore, there is no possibility that the filled filler material 33 leaks to the outside of the pipe 20.

Further, since the metal wool 31 made of the metal wire 32 is used as the base material impregnated with the filler 33, the heat conduction performance is higher than that in which the fabric fiber is entangled, and the heat dissipation efficiency is excellent.
Moreover, since it is set as the form which the heat-transfer member 30 surrounds the electric wire 10 over a perimeter, the electric wire 10 and the heat-transfer member 30 can be inserted together in a cylindrical protection member.
In addition, since the heat transfer member 30 collectively surrounds the three (plural) electric wires 10, the insertion process for the pipe 20 can be completed only once.

In addition, since the heat transfer member 30 is spirally wound around the outer periphery of the electric wire 10, the manufacture is easier as compared with a case where the electric wire is inserted into a heat transfer member that is previously formed into a cylindrical shape.
Further, since the metal pipe 20 having a shielding function is used as the cylindrical protective member, it is realized that the non-shielded wire 10 is used. Since the non-shield type electric wire 10 does not have a braided wire, it has an advantage that the terminal processing is simple.
Moreover, since a part of the filler 33 impregnated in the metal wool 31 is interposed in the gap between the adjacent electric wires 10, direct friction between the insulating coatings 12 of the electric wires 10 is prevented.

<Other embodiments>
The present invention is not limited to the embodiment described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.
(1) In the above embodiment, three electric wires are inserted into one pipe (cylindrical protective member). However, according to the present invention, the number of electric wires inserted into one pipe is one, two, Any of four or more may be used.
(2) In the above embodiment, the air pool remains in the center of the stacked wire bundle in the pipe. However, according to the present invention, the resin is filled in the center of the wire bundle so that the air pool does not occur. It is good also as a form.
(3) In the above embodiment, the electric wires are arranged in a stack in the pipe. However, according to the present invention, the electric wires may be arranged in a line, and arranged in a row and a row. May be.
(4) Although the pipe has a circular cross section in the above embodiment, according to the present invention, the cross section of the pipe may be non-circular (an oval, an ellipse, a trapezoid, a generally polygon including a parallelogram, etc.). .
(5) In the above embodiment, the cylindrical protective member is a metal pipe having a shielding function in addition to the protective function. However, according to the present invention, the electric wire is braided on the outer periphery of the core surrounding the conductor. In the case of a shielded electric wire in a form in which the shield layer is covered and surrounded by a sheath, the cylindrical protective member is a member that does not have a shielding function, such as a corrugated tube made of synthetic resin. Also good.
(6) In the above embodiment, the heat transfer member is spirally wound around the electric wire. However, according to the present invention, the heat transfer member may be inserted into the heat transfer member formed in a cylindrical shape in advance.
(7) In the above embodiment, a plurality of (three) electric wires are collectively surrounded by the heat transfer member. However, according to the present invention, one electric wire is individually surrounded by the heat transfer member and bundled. It may be inserted through a pipe.
(8) In the above embodiment, the heat transfer member surrounds the entire circumference of the electric wire. However, according to the present invention, a part of the outer circumference of the electric wire is brought into close contact with the inner circumference of the pipe, and the other part. May be filled with a heat transfer member.
(9) In the above embodiment, the heat transfer member and the electric wire are inserted together into the cylindrical protective member. However, according to the present invention, the heat transfer member and the electric wire may be inserted in separate steps.

Partially cutaway side view of Embodiment 1 Schematic diagram showing the process of manufacturing heat transfer members Partial enlarged view showing the process of manufacturing a heat transfer member Side view showing how a heat transfer member is wrapped around an electric wire Cross-sectional view showing a state where a heat transfer member is wound around an electric wire Longitudinal sectional view showing heat transfer member and electric wire inserted into pipe

Explanation of symbols

Wa ... Shield conductor 10 ... Electric wire 20 ... Pipe (tubular protective member)
30 ... Heat transfer member 31 ... Metal wool (base material)
33 ... filler

Claims (8)

Electric wires,
A cylindrical protective member surrounding the wire;
A heat transfer member in a form in which a base material composed of a plurality of thin wire rods that are filled in a gap between the electric wire and the cylindrical protective member and intertwined with each other is impregnated with a filler having a higher thermal conductivity than air. The shield conductor characterized by the above-mentioned. The shield conductor according to claim 1, wherein the base material is metal wool having a plurality of fine metal wires entangled. The shield conductor according to claim 1, wherein the heat transfer member surrounds the electric wire over the entire circumference. The shield conductor according to any one of claims 1 to 3, wherein the heat transfer member collectively surrounds the plurality of electric wires. The shield conductor according to any one of claims 1 to 4, wherein the heat transfer member is spirally wound around an outer periphery of the electric wire. The shield conductor according to any one of claims 1 to 5, wherein the cylindrical protection member is a metal pipe. A method of manufacturing a shield conductor in a form in which a gap between an electric wire and a cylindrical protective member surrounding the electric wire is filled with a filler having a higher thermal conductivity than air,
A method of manufacturing a shield conductor, comprising: inserting a heat transfer member in the form of impregnating the filler into a base material composed of a large number of thin wires intertwined with each other into the cylindrical protective member. The heat transfer member is wound around the electric wire, and the heat transfer member and the electric wire are inserted into the cylindrical protection member in a state where the outer diameter of the heat transfer member is larger than the inner diameter of the cylindrical protection member. The method for producing a shield conductor according to claim 7.

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