阅读说明：本技术 电线导体、包覆电线、线束及电线导体的制造方法 (Electric wire conductor, covered electric wire, wire harness, and method for manufacturing electric wire conductor ) 是由 大井勇人 大塚保之 田口欣司 于 2018-03-14 设计创作，主要内容包括：本发明的课题在于提供一种省空间性、柔软性优异且负荷难以集中于特定的线材的电线导体、具备该电线导体的包覆电线及线束。主旨在于,由将多个线材绞合而成的绞合线构成,所述绞合线的与轴向交叉的截面具有扇形部,该扇形部具有一条边或者通过顶点而相互连接的两条边、以及将所述边的端部连接的向外凸出的曲线,所述扇形部的与轴向交叉的截面中的所述线材的从圆形开始的变形率在所述扇形部的面向外周的外周部比所述扇形部的中央部小。(The invention provides a wire conductor which is space-saving, excellent in flexibility and less prone to load concentration on a specific wire, and a covered wire and a wire harness provided with the wire conductor. The twisted wire is characterized by being formed of a twisted wire in which a plurality of wires are twisted, a cross section of the twisted wire intersecting with an axial direction has a sector portion having one side or two sides connected to each other through an apex, and an outwardly convex curve connecting end portions of the sides, and a deformation rate of the wires in the cross section of the sector portion intersecting with the axial direction from a circular shape is smaller in an outer peripheral portion facing an outer periphery of the sector portion than in a central portion of the sector portion.)

1. A conductor for electric wire characterized in that,

the wire conductor is formed of a twisted wire obtained by twisting a plurality of wires,

the cross section of the strand intersecting the axial direction has a sector having one side or two sides connected to each other by an apex and an outwardly convex curve connecting the ends of the sides,

a deformation rate of the wire rod from a circular shape in a cross section of the sector portion intersecting with an axial direction is smaller at an outer peripheral portion of the sector portion facing an outer periphery than at a central portion of the sector portion located inside the outer peripheral portion.

2. The electric wire conductor according to claim 1,

a deformation ratio of the wire rod from a circular shape in a cross section intersecting an axial direction of the sector portion is 75% or less of a deformation ratio of a central portion of the sector portion at an outer peripheral portion of the sector portion facing an outer periphery.

3. The electric wire conductor according to claim 1 or 2,

a deformation ratio of the wire rod from a circular shape in a cross section intersecting an axial direction of the sector portion is 15% or less at an outer peripheral portion of the sector portion facing an outer periphery.

4. The electric wire conductor according to any one of claims 1 to 3,

in a cross section of the segment intersecting the axial direction, a void ratio, which is a proportion of voids not occupied by the wire rod, is 15% or more.

5. The electric wire conductor according to any one of claims 1 to 4,

the segment has a continuous space capable of accommodating one or more wires in a cross section intersecting the axial direction.

6. The electric wire conductor according to any one of claims 1 to 5,

the number of wires constituting the litz wire is 50 or more.

7. The electric wire conductor according to any one of claims 1 to 6,

at least a portion of the wire is composed of aluminum or an aluminum alloy.

8. A covered electric wire, comprising:

the electric wire conductor of any one of claims 1 to 7; and

and an insulator covering an outer periphery of the wire conductor.

9. A wire harness comprising the covered electric wire according to claim 8.

10. A wire harness, characterized in that,

the wire harness comprising a plurality of the covered electric wires according to claim 8,

the plurality of coated wires are arranged so that the sides of the segment face each other with the insulator therebetween.

11. The wire harness according to claim 10,

a heat sink is interposed between the plurality of coated wires.

12. A method for manufacturing a conductor for electric wire,

the wire conductor according to any one of claims 1 to 8 is manufactured by performing a compression step of pressing a raw material strand, which is formed by twisting wire members, from a first direction and a second direction that intersect with and face each other in an axial direction of the raw material strand using a roller.

13. The manufacturing method of electric wire conductor according to claim 12,

at least one of the rollers has a groove portion in contact with the raw material strand in at least a part thereof in a circumferential direction,

the roller is in contact with the other roller at the end of the groove, and the end of the groove is provided with a cut for preventing the wire material constituting the raw material strand from being sandwiched between the rollers.

Technical Field

The present invention relates to an electric wire conductor, a coated electric wire, a wire harness, and a method for manufacturing an electric wire conductor, and more particularly, to an electric wire conductor in which a stranded wire obtained by twisting a plurality of wire members is deformed, a coated electric wire and a wire harness provided with such an electric wire conductor, and a method for manufacturing such an electric wire conductor.

Background

In recent years, higher performance of automobiles has been advanced, and the number of electric wires and parts to be installed in automobiles has increased. On the other hand, in an electric vehicle or the like, the diameter of a wire used for increasing the current becomes large.

In addition, although aluminum or an aluminum alloy is often used as the wire conductor from the viewpoint of weight reduction of the wire and the like, since aluminum or an aluminum alloy has a smaller conductivity than copper or a copper alloy, in the wire using aluminum or an aluminum alloy as the wire conductor, it is necessary to increase the conductor cross-sectional area in comparison with the case of using copper or a copper alloy in order to ensure a desired conductivity, and the outer diameters of the wire conductor and the coated wire provided with an insulator on the outer periphery of the wire conductor are increased.

As described above, the space in which the wires can be wired is reduced by increasing the number of wires or components, increasing the diameter of the wires, and the like, and it is required to efficiently wire the wires or the wire harness while securing the conductor cross-sectional area. The wires constituting the wire harness are generally configured in a circular cross-sectional shape, but if the wires in a circular cross-sectional shape are to be bundled or arranged, a large amount of wasted space is generated.

As a wire harness, a plurality of electric wires are sometimes bundled by a tube or the like for the purpose of electromagnetic shielding, prevention of interference with foreign matter, or the like. In this case, for the purpose of reducing the wasted space in the pipe, for example, patent document 1 describes a case where the cross section of the electric wire conductor composed of a single core conductor is formed in a semicircular shape.

Prior art documents

Patent document

Patent document 1: japanese patent laid-open publication No. 2016-054030

Disclosure of Invention

Problems to be solved by the invention

In order to efficiently wire the electric wire, it is preferable to flexibly bend the electric wire and wire along a limited space. However, in the case of an electric wire conductor composed of a single core conductor as in patent document 1, flexibility of each electric wire is poor and the degree of freedom of wiring is low. In particular, in the case of an electric wire having a large cross-sectional area of a conductor, there is a problem in terms of wiring properties.

Flexibility can be improved if the same wire conductor as in patent document 1 is formed using a stranded wire made of a plurality of wires. Conventionally, when such a wire conductor is manufactured, the following processing method is used: for example, a processing method such as drawing processing in which a force is applied to the wire conductor so as to stretch the wire conductor in the axial direction using a compression die or the like. However, such a processing method has problems that a load is likely to concentrate on the wire material on the outer periphery, a sharp protruding structure (burr) is likely to be formed on the outer periphery, and the like, and is difficult to be applied to a wire conductor having a large conductor cross-sectional area or a wire conductor having a large number of wire materials constituting a stranded wire.

In view of the above problems, an object of the present invention is to provide an electric wire conductor which is excellent in flexibility and in which load is less likely to concentrate on a specific wire material, and a coated electric wire and a wire harness including the electric wire conductor.

Means for solving the problems

The electric wire conductor according to the present invention is characterized in that the electric wire conductor is formed of a twisted wire in which a plurality of wires are twisted, a cross section of the twisted wire intersecting with an axial direction has a sector portion having one side or two sides connected to each other through an apex, and an outwardly convex curve connecting end portions of the sides, and a deformation rate of the wires in the cross section of the sector portion intersecting with the axial direction from a circular shape is smaller at an outer peripheral portion facing an outer periphery of the sector portion than at a central portion of the sector portion.

Preferably, a deformation ratio of the wire rod from a circular shape in a cross section intersecting the axial direction of the sector portion is 75% or less of a deformation ratio of a central portion of the sector portion in an outer peripheral portion of the sector portion facing an outer periphery.

Preferably, a deformation ratio of the wire rod from a circular shape in a cross section intersecting with an axial direction of the sector portion is 15% or less at an outer peripheral portion facing an outer periphery of the sector portion.

Preferably, in a cross section of the segment portion intersecting the axial direction, a void ratio, which is a proportion of voids not occupied by the wire rod, is 15% or more.

Preferably, the segment has a continuous space capable of accommodating one or more wires in a cross section intersecting with the axial direction.

Preferably, the number of wires constituting the litz wire is 50 or more.

Preferably, at least a part of the wire rod constituting the wire conductor is made of aluminum or an aluminum alloy.

The covered electric wire of the present invention includes: the above-mentioned electric wire conductor; and an insulator covering the outer periphery of the wire conductor.

The wire harness of the present invention includes the above-described covered electric wire.

Preferably, the wire harness includes a plurality of the coated wires, and the plurality of coated wires are arranged so as to face each other with the edges of the fan-shaped portion interposed between the insulators.

Preferably, a heat sink is interposed between the plurality of coated wires.

The method for manufacturing an electric wire conductor according to the present invention is characterized in that a raw material strand obtained by twisting wire materials is subjected to a compression step of pressing the raw material strand in a first direction and a second direction that intersect with and face each other in an axial direction of the raw material strand using a roller, thereby manufacturing the electric wire conductor.

Preferably, at least one of the rollers has a groove portion in contact with the raw material strand at least partially in a circumferential direction, the roller is in contact with the other roller at an end portion of the groove portion, and a notch for preventing the wire material constituting the raw material strand from being sandwiched between the rollers is provided at the end portion of the groove portion.

Effects of the invention

The electric wire conductor of the present invention is not a single core conductor but is formed of a twisted wire obtained by twisting a plurality of wire members, and therefore has high flexibility. In particular, when the stranded wire is a collective stranded wire formed by collectively stranding a plurality of wires, the wires are less likely to cross each other when the shape of the electric wire is deformed, so that an excessive load is prevented from being applied to the wires, and the stranded wire is excellent in flexibility.

In addition, the deformation rate of the wire rod from the circular shape at the outer peripheral portion of the segment portion of the electric wire conductor of the present invention is smaller than the deformation rate of the wire rod from the circular shape at the central portion. That is, when the shape of the electric wire is deformed, the load acting on the wire in the outer peripheral portion is smaller than the load acting on the wire in the central portion. This prevents the load from concentrating on the wire material of the outer peripheral portion to form a concave-convex structure (burr) such as a broken wire or a sharp protrusion on the outer peripheral portion, and sufficiently deforms and compresses the wire conductor.

In the electric wire conductor according to the present invention, the cross section of the electric wire conductor intersecting the axial direction has a fan shape having one side or two sides connected to each other via a vertex, and an outwardly convex curve connecting the ends of the sides, and therefore, when a plurality of coated electric wires formed of the electric wire conductor are bundled and used, the plurality of coated electric wires can be wired without a gap, and space saving is excellent. The central angle of the sector is not particularly limited. When the central angle is 180 degrees, the central angle is a semicircular shape with one side.

The deformation rate from the circular shape of the wire in the outer peripheral portion of the segment is preferably 75% or less of the deformation rate from the circular shape of the wire in the central portion. More preferably 70% or less, and still more preferably 50% or less. If the deformation rate of the wire material from the circular shape at the outer peripheral portion of the segment portion is 75% or less of the deformation rate of the wire material from the circular shape at the central portion, it is possible to obtain an effect of preventing the load from concentrating on the wire material at the outer peripheral portion to form a concave-convex structure such as a broken wire or a sharp protrusion at the outer peripheral portion, and sufficiently deforming and compressing the wire conductor.

The deformation rate of the wire in the outer peripheral portion of the segment from the circular shape is preferably 15% or less, and more preferably 10% or less. If the deformation rate of the wire material in the outer peripheral portion of the segment from the circular shape is 15% or less, an effect of preventing the load from concentrating on the wire material in the outer peripheral portion and forming a concave-convex structure such as a broken wire or a sharp protrusion in the outer peripheral portion can be obtained particularly highly.

When the ratio of voids not occupied by the wire rod, that is, the void ratio is 15% or more in the cross section of the segment, particularly high flexibility is easily maintained, and the degree of freedom of wiring is excellent.

When the segment has a continuous space capable of accommodating one or more wires in the cross section, the wire conductor can be flexibly bent by the movement of the wire into the space, and the effect of maintaining the flexibility of the wire conductor at a high level is particularly excellent.

When the number of the wires constituting the stranded wire is 50 or more, the stranded wire can be easily formed into a fan-shaped cross section by changing the relative arrangement of the wires without greatly deforming each wire. This makes it easy to achieve both space saving and flexibility in the wire conductor, and also prevents disconnection of the wire rod.

The coated electric wire of the present invention has the above-described electric wire conductor, and thus is excellent in space saving and has high flexibility. Further, by forming the conductor in a fan shape, unevenness on the surface of the conductor can be suppressed, the thickness of the insulator can be reduced, and space saving is excellent.

The wire harness of the present invention has the above-described covered electric wire, and thus is excellent in space saving and has high flexibility. When a plurality of coated electric wires are bundled, the side portions of the fan-shaped portions are arranged to face each other, so that the cross section of the combination of the plurality of coated electric wires is formed into a substantially circular shape in which curved portions connecting the side portions are connected, and the combination of the plurality of coated electric wires is easily stored in a pipe or the like, and is particularly excellent in space saving.

The wire harness according to the present invention is less likely to emit heat at the side portions of the opposing fan-shaped portions than at the curved portions or the like that are released outward, because of the proximity of the distances between the wires. However, by interposing the heat sink on the side portion, even if the plurality of covered wires are arranged in a bundle by a tube or the like, the influence of heat generation at the time of energization can be suppressed. In this case, if the covered wires are bundled by using a highly heat conductive tube such as aluminum, for example, heat can be efficiently radiated from both the fan-shaped side portion and the curved portion.

According to the method for manufacturing an electric wire conductor of the present invention, by applying a force from two directions intersecting the axial direction of the raw material strand, it is possible to suppress concentration of a load on the wire material of the outer peripheral portion as compared with, for example, conventional drawing processing, and to reduce the deformation rate of the wire material of the outer peripheral portion and deform the electric wire conductor. Thus, the wire conductor can be formed into a fan-shaped shape while preventing the formation of a broken wire or a burr caused when a large force is applied only to the wire material in the outer peripheral portion, and the space-saving property is excellent.

At least one of the rollers has a groove portion in contact with the raw material strand at least in a part thereof in a circumferential direction, and when a notch for preventing the wire material constituting the raw material strand from being sandwiched is provided at an end portion of the groove portion, a relief portion capable of accommodating the wire material can be formed in a gap formed by the groove portions of the opposing rollers. The escape portion can make it difficult for the wire rod constituting the raw material stranded wire to be sandwiched between the rollers, and prevent the wire rod from being broken or forming burrs due to the sandwiching of the wire rod.

Drawings

Fig. 1 is a perspective view showing an electric wire conductor according to a first embodiment of the present invention.

Fig. 2 is a sectional view of the above-described electric wire conductor.

Fig. 3 is a cross-sectional view of a conventional covered electric wire in which an electric wire conductor is not compressed.

Fig. 4(a) is a sectional view of the coated electric wire of the present invention disposed in a tube, and (b) is a sectional view of the conventional coated electric wire disposed in a tube. In this figure, the wire is omitted.

Fig. 5 is a cross-sectional view illustrating compression of the raw material strand.

Fig. 6(a) is a perspective view of the roller deforming the wire conductor, and (b) is an enlarged view of a portion where the roller contacts the wire conductor.

Fig. 7 is a photograph showing a cross section of a coated wire, where (a) shows a raw material strand before compression, (b) shows a sample 1 compressed at a low pressure, and (c) shows a sample 2 compressed at a high pressure.

Detailed Description

Next, embodiments of the present invention will be described in detail with reference to the drawings.

In the present specification, the shape of a circle, a sector, a side, a straight line, a circular arc, or the like is not limited to a geometric meaning, and may be a shape that can be recognized as a circle, a sector, a side, a straight line, a circular arc, or the like, including variations due to materials, manufacturing processes, or the like.

Fig. 1 is a perspective view showing an external appearance of an electric wire conductor 10 according to an embodiment of the present invention. Fig. 2 shows a cross section of the wire conductor 10 orthogonal to the axial direction (longitudinal direction). In these drawings, the number of wires 1 constituting the wire conductor 10 is reduced for the sake of easy understanding.

[ conductor of electric wire ]

The wire conductor 10 is formed as a stranded wire obtained by twisting a plurality of wires 1 with each other. Also, the electric wire conductor 10 has a sectional fan shape having 1 side or 2 sides connected to each other by a vertex and an outwardly convex curve connecting ends of the sides at least at a portion in the axial direction. When the number of sides is 1, the shape is a semicircular shape. In the present embodiment, the entire region of the wire conductor 10 is shown as having a sector-shaped cross section.

In the electric wire conductor 10 of the present embodiment, in the cross section orthogonal to the axial direction, in the outer peripheral portion facing the outer periphery of the electric wire conductor 10, the deformation rate of the wire rod 1 is reduced as compared with the central portion located inside the outer peripheral portion. Fig. 1 and 2 schematically show the distribution of the deformation ratio of such a wire 1.

Here, the deformation ratio of the wire 1 is an index indicating how far a certain wire 1 has a cross section deviating from a circular shape. Regarding the wire 1 actually included in the electric wire conductor 10, if the length of the longest straight line crossing the cross section is defined as the major diameter a and the diameter of a circle having the same area as the cross section area of the wire 1 is defined as the circle diameter R, the deformation ratio D of the wire 1 can be expressed as follows.

D＝(A-R)/R×100％ (1)

The circular diameter R may be calculated by measuring an actual cross-sectional area of the wire rod 1, and when the diameter of the wire rod 1 before being deformed is known or when an undeformed portion of the wire rod 1 coexists in the same wire conductor 10, the diameter of the wire rod 1 not subjected to the deformation may be adopted as the circular diameter R. Further, only the wire 1 disposed on the outermost periphery of the electric wire conductor 10 may be used as the wire 1 on the outer peripheral portion, and only the wire 1 disposed on the center of the conductor may be used as the wire 1 on the central portion, but from the viewpoint of reducing the influence of variations in deformation of the wire 1 and the like, it is preferable to estimate the deformation ratio as an average value for a plurality of wires 1 included in a region over a certain area.

If the deformation ratio of the wire 1 in the outer peripheral portion is smaller than that of the wire 1 in the central portion, it is possible to prevent the wire 1 in the outer peripheral portion from being concentrated with a load and forming a concave-convex structure (burr) such as a broken wire or a sharp protrusion in the outer peripheral portion, and to sufficiently deform and compress the wire conductor. In particular, when the electric wire conductor 10 of the present embodiment is manufactured by deforming a conventional general electric wire conductor having a substantially circular cross section by compression or the like, it is possible to suppress concentration of a load on the wire rod 1 in the outer peripheral portion due to a force applied to compress the wire conductor.

The deformation ratio of the wire in the outer peripheral portion is preferably 75% or less of the deformation ratio of the wire in the central portion. More preferably 70% or less, still more preferably 50% or less, and particularly preferably 20% or less. When the deformation ratio of the wire rod at the outer peripheral portion of the segment portion is 75% or less of the deformation ratio of the wire rod at the central portion, the following effects can be obtained: the wire conductor is prevented from being deformed and compressed sufficiently while a load is concentrated on the wire material of the outer peripheral portion to form a concave-convex structure such as a broken wire or a sharp protrusion on the outer peripheral portion.

The deformation rate of the wire in the outer peripheral portion of the segment from the circular shape is preferably 15% or less, more preferably 10% or less, and still more preferably 5% or less. When the deformation ratio of the wire material in the outer peripheral portion of the segment is 15% or less, an effect of preventing a load from concentrating on the wire material in the outer peripheral portion and forming a concave-convex structure such as a broken wire or a sharp protrusion in the outer peripheral portion can be obtained particularly highly.

The outer peripheral portion can be classified into 4 portions of a fan-shaped side portion, a curved portion, a corner portion connecting the side portion and the curved portion, and a vertex portion connecting the side portion and the side portion. The magnitudes of the deformation ratios at these 4 positions tend to be in the order of side portion > curved portion > corner portion > apex portion.

The central angle of the sector shape in the cross section of the wire conductor 10 is not particularly limited. When the center angle is 180 degrees, the edge is formed in a semicircular shape with 1 piece. The center angle may be appropriately determined according to the wiring method, and for example, when 3 wires having the same thickness are wired together, the center angle of all the wires may be set to about 120 degrees, and when a plurality of wires having different thicknesses are wired together, the center angle may be changed according to the thickness.

The electric wire conductor 10 of the present embodiment is formed of a stranded wire obtained by stranding a plurality of wire members 1. Therefore, the electric wire conductor 10 has high flexibility as compared with a single core conductor of the same conductor cross-sectional area.

The stranded wire includes a concentric strand in which a plurality of wires are stranded around a center wire in a layered and concentric manner, an aggregate strand in which a plurality of wires are collectively stranded, and a composite strand in which a plurality of stranded wires stranded in advance are further stranded with each other. The wire conductor 10 of the present embodiment can be manufactured by compressing and deforming a raw material stranded wire 10' having a substantially circular cross section, which will be described in detail later. The raw material strand 10' is preferably an integrally stranded or concentrically stranded strand, and more preferably an integrally stranded strand. When the strand material strand 10' is deformed, the wires 1 are difficult to cross each other, and the load is difficult to be concentrated on a part of the wires. Among these, in the collectively twisted strand, even if the number of the constituent wires 1 is increased, the twisted structure is not complicated, and productivity is excellent.

The wire 1 constituting the wire conductor 10 may be made of any conductive material such as a metal material. Typical materials constituting the wire rod 1 include copper and copper alloys, and aluminum alloys. These metal materials are easily formed into a desired shape by deformation when forming a stranded wire, and are suitable for forming the electric wire conductor 10 of the present embodiment in a point where the temporarily formed shape is easily and firmly maintained. From the viewpoint of weight reduction, cost, and the like of the wire conductor 10, the size in the sense of reducing the conductor diameter by compression, and the like, aluminum or an aluminum alloy is preferable. As the wire 1 constituting the wire conductor 10, a wire made of the same material may be used, or a plurality of wires 1 made of different materials may be mixed and used. In the case where the wire conductor 10 is composed of a plurality of kinds of wire rods 1 composed of different materials, the deformation ratios of the outer peripheral portion and the central portion are preferably compared with each other by the wire rods 1 composed of the same material or by an average value of the deformation ratios of the plurality of kinds of wire rods 1.

The number of the wires 1 constituting the wire conductor 10 may be arbitrarily selected according to desired conductivity or the like, and a preferable range of the number of the wires 1 is 50 or more. When the number of the wires 1 constituting the litz wire is large, flexibility is excellent. In particular, when the number of the wires 1 is 50 or more, even if the wires are not largely deformed, a large space can be left between the wires by changing the relative arrangement of the wires, and the twisted wire can be easily formed into a fan-shaped cross section, and in particular, an excessive load can be prevented from being applied to the wires 1 on the outer peripheral portion.

The conductor cross-sectional area of the wire conductor 10 may be arbitrarily selected according to a desired resistance value or the like, but a preferable range of the conductor cross-sectional area of the wire conductor 10 is, for example, 3mm²The above. More preferably 50mm²The above. When the cross-sectional area of the conductor is 3mm²In the above case, the effect of saving space by forming the wire conductor 10 in a sector shape in cross section is large. In the above case, a preferable diameter of the wire 1 constituting the wire conductor 10 is 0.3 to 1.0 mm.

In the electric wire conductor 10 of the present embodiment, the outer shape of the entire electric wire conductor 10 may be a sector-shaped cross section, and the cross-sectional shape of each wire 1 constituting the electric wire conductor 10 may be arbitrary. A general metal wire has a substantially circular cross section, and in the present embodiment, such a wire 1 can be applied. The wire 1 of at least a part of the wire conductor 10 may remain in a substantially circular shape without being deformed when formed into a fan shape. In the electric wire conductor 10 of the present embodiment, the wire rod 1 is likely to remain undeformed particularly in the outer peripheral portion.

In the wire conductor 10, if the ratio of the voids not occupied by the wires 1, that is, the void ratio is secured to 15% or more in advance in the cross section, the wires 1 can be arranged in various relative positions by utilizing the voids between the wires 1, and therefore, the cross section of the wire conductor 10 can be easily formed into a desired shape by utilizing the relative positions of the wires 1 without greatly deforming the shapes of the wires 1 themselves. The upper limit of the porosity is not particularly limited, but is preferably 30% or less from the viewpoint of ease of molding into a fan shape, ease of maintaining the fan shape after formation, and the like. The porosity is a ratio of an area occupied by the total area of the voids having various sizes and shapes in the cross section of the electric wire conductor 10, and when the total area of the voids is within a predetermined range in the cross section of the electric wire conductor 10, the flexibility of the electric wire conductor 10 can be improved, but in addition, it is effective for improving the flexibility of the electric wire conductor 10 when the voids having a certain size are present as a continuous region. Specifically, the cross section of the wire conductor 10 preferably has a continuous gap capable of accommodating 1 or more, and further 2 or more, of the wire rods 1. The reason is that the flexible bending of the electric wire is assisted by the movement of the wire 1 to such a large gap. Here, as the wire 1 that can be stored in the gap, the wire 1 surrounding the gap of interest or the wire 1 having a circular cross-section having the same cross-sectional area as that of any wire 1 constituting the wire conductor 10 may be used.

In general, when compression processing is not performed, in particular, in the stranded wire 10 'in which the number of the wire rods 1 constituting the stranded wire 10' is small, irregularities are generated on the outer periphery of the stranded wire as shown in fig. 3. When the strand is coated with the insulator 20, it is necessary to secure a sufficient thickness of the insulator 20 so that the properties such as abrasion resistance can be satisfied even in the thinnest portion of the insulator 20. By forming the wire conductor 10 into a fan-like shape by the compression step, the unevenness of the outer circumference of the stranded wire can be reduced, and the insulator 20 having a thickness satisfying each characteristic can be formed with a uniform thickness over the entire circumference, so that the insulator 20 having an average thickness over the entire circumference can be reduced, and the space saving property is excellent.

As described above, the electric wire conductor 10 of the present embodiment achieves both space saving and flexibility, and has a high degree of freedom in wiring. For example, in automobiles, the number of wires and parts to be installed has increased due to recent advanced functions. In addition, in electric vehicles and the like, a large current is increasing, and the wire diameter is also becoming large. This reduces the space in which the wires can be wired. The wire conductor 10 of the present invention is excellent in space saving and flexibility, and thus can effectively use a small space for wiring a wire. The effect is particularly increased when a plurality of wires are integrated or when a wire having a large conductor cross-sectional area is used.

[ formation of conductor of electric wire ]

The method of manufacturing the electric wire conductor 10 of the present embodiment is not particularly limited, but for example, as shown in fig. 5, the electric wire conductor may be formed by compressing a raw material strand 10' obtained by stranding a plurality of wire materials 1. At this time, forces F1, F2 are applied from a first direction and a second direction orthogonal to the axial direction of the raw material twisted wire 10' and opposed to each other. If necessary, the raw material strands 10' may be applied with forces F3, F4 from a third direction and a fourth direction intersecting the first direction and the second direction and opposing each other. By applying the force from at least two opposite directions, the raw material strand 10' can be deformed efficiently. Further, by applying the force in a plurality of different directions, it is possible to prevent the pressure from being unevenly applied to the wire material 1 on the outer peripheral portion of the raw material strand 10', and the deformed wire conductor 10 can be formed without forming a disconnection or a burr on the wire material 1 on the outer peripheral portion.

The application of the force to the raw material strand 10 'may be performed by arranging the rollers 60 to face each other and passing the raw material strand 10' between the rollers 60, as shown in fig. 6, for example. When the rollers 60 are used, the pair of opposing rollers 60 rotate in opposite directions to each other, and the raw material twisted wire 10 'can be fed out by the rotation of the rollers 60 to apply a force to the raw material twisted wire 10'. At this time, the raw material strand 10' can be applied with no force of stretching in the axial direction as in the case of compression using a die, and can be applied from the outside toward the inside in the radial direction. Further, since the rollers are largely opened on the front side in the conveying direction of the raw material strand 10', a large force is not applied, and the force applied toward the contact point of the 2 rollers 60 gradually increases. Thus, the applied force is distributed over the entire raw material strand 10', and the load can be prevented from concentrating on the outer peripheral portion. In addition, when the roller 60 is used, the long raw material strand 10' can be continuously processed while being fed out, and productivity is excellent.

The roller 60 has a groove portion 61 along its circumferential direction, and the groove portion 61 is in contact with the raw material strand 10' at least at a part thereof. The cross-sectional shape of the wire conductor 10 compressed by the roller 60 reflects the shape of the groove portion 61 in contact with the raw material strand 10'. For example, as shown in fig. 6 (b), the wire conductor 10 having a sector-shaped cross section can be obtained by providing an arc-shaped groove portion in one roller 60a of the pair of rollers and a V-shaped groove portion in the other roller 60 b.

The groove 61 is preferably provided with a notch 62 at an end thereof at a position where the rollers 60 face each other so as not to sandwich the wire rod 1 between the rollers. Specifically, as shown in fig. 6 (b), a structure in which the raw material strand 10' is inclined so as to be separated from the raw material strand in the axial direction of the roller 60 can be exemplified. When the raw material strand 10' is compressed, if a part of the constituent wire 1 is pinched between the rollers, a burr that is sharply deformed in a protruding manner is formed, or the pinched wire 1 may be broken, but if the notches 62 are provided at the ends of the groove portions 61, the gap formed by the groove portions 61 of the opposing rollers 60 forms relief portions 63 that receive the wire 1 so as to avoid pinching, and the wire 1 is difficult to be pinched. This prevents the occurrence of burrs or disconnection due to the sandwiching.

As described above, the wire conductor 10 having the deformation ratio of the outer peripheral portion smaller than that of the central portion can be manufactured by applying the forces F1 and F2 from the first direction and the second direction orthogonal to the axial direction of the raw material strand 10' and opposing each other using the rollers. Conventionally, when an electric wire conductor made of a stranded wire having a substantially circular cross section is deformed, a processing method such as drawing processing in which a force is applied so as to stretch the electric wire conductor in an axial direction using a compression die or the like is used, but in such a processing method, a load tends to concentrate on a wire material of an outer peripheral portion, and a deformation rate of the wire material of the outer peripheral portion tends to increase. Therefore, in particular, when a wire conductor having a large conductor cross-sectional area or a wire conductor having a large number of wires constituting a stranded wire is deformed, a large drawing force is required, and burrs or wire breakage is likely to occur, which makes the manufacturing difficult. The manufacturing method of the present embodiment is particularly suitable for a case where a large cross-sectional area and a large number of wires constituting a stranded wire have been difficult to manufacture in the past.

[ covered electric wire ]

The covered wire 30 according to the embodiment of the present invention includes the wire conductor 10 according to the embodiment of the present invention as described above, and the insulator 20 covering the outer periphery of the wire conductor 10.

The material of the insulator 20 is not particularly limited, and may be made of various polymer materials. The polymer material may contain a filler or an additive as appropriate. The material and thickness of the insulator 20 may be appropriately selected according to desired characteristics such as abrasion resistance and flexibility of the insulator 20. The thickness of the insulator 20 is preferably not too large from the viewpoint of space saving, flexibility, and the like. For example, a preferable embodiment is one in which the thickness of the insulator is 2.0mm or less on average.

The wire conductor 10 is formed in a sector shape in cross section, so that the unevenness of the outer peripheral portion can be reduced, the thickness of the insulator 20 can be reduced, and the wire conductor can be formed uniformly. This can reduce the thickness of the extra insulator 20, and is excellent in space saving.

The insulator 20 may be configured to integrally surround the entire circumference of the wire conductor 10. In this case, the polymer material to be the insulator 20 can be formed around the entire circumference of the wire conductor 10 by extrusion or the like, thereby providing the insulator 20.

If a roller device for deforming the wire conductor 10 and an extrusion device for extruding the insulator 20 are continuously provided, the steps until the wire conductor 10 compressed from the raw material strand 10' is formed and the coated wire 30 is manufactured can be continuously performed, and productivity is excellent. The steps of manufacturing the wire material 1 constituting the raw material strand 10 ', stranding the wire material 1, deforming the raw material strand 10' obtained by stranding, and pressing the insulator 20 are all continuously performed for each part of the long material, and by continuously performing these steps, high productivity can be achieved.

The coated electric wire 30 may be used alone in a state in which the outer periphery of the single electric wire conductor 10 is coated with the insulator 20, or may be used as a wire harness in which a plurality of coated electric wires 30 are integrally combined using a coating material or the like. The case of using the wire harness will be described below.

[ Wiring harness ]

The wire harness according to the embodiment of the present invention is configured by bundling a plurality of coated wires 30, and at least a part of the plurality of coated wires 30 is constituted by the coated wire 30 according to the embodiment of the present invention having the wire conductor 10 having a sectional fan shape. The wire harness may be configured by using only the coated wire having the wire conductor 10 with a fan-shaped cross section as described above, or may be configured by using other types of coated wires such as the coated wire 30 with a fan-shaped cross section and the coated wire having a generally circular wire conductor. In the case where a wire harness is configured by using a plurality of coated wires 30 each having a wire conductor 10 having a fan-shaped cross section according to the present invention, the material, shape, size, and the like of the wire conductors 10 and the insulators 20 configuring the plurality of coated wires 30 may be the same or different from each other.

Since a wire harness formed by bundling general coated wires has a large volume as a whole, if a wiring space is to be secured in an automobile, a remaining space (a space in which a passenger can stay) may be narrowed. However, as described above, the covered electric wire 30 composed of the electric wire conductor 10 is used, and the space required for wiring of the wire harness is suppressed to be small, whereby the living space can be secured to be wide.

For example, when a plurality of coated wires 30 are used together by using a tube or the like, if the cross section of each of the wire conductor 10 and the coated wire 30 has a fan shape having 1 side or 2 sides connected to each other by a vertex and an outwardly convex curve connecting the ends of the sides, the space saving property is excellent. In particular, in a wire harness arranged under the floor of an automobile, a plurality of coated wires 30 may be arranged inside a cylindrical tube shield 40, but in this case, if the coated wires 30 are circular, an extra space is generated inside the tube shield 40 as shown in fig. 4(b), and it is necessary to use a tube shield 40 having a large diameter, but if the coated wires 30 having a semicircular or fan-shaped cross section are arranged such that the sides of the fan-shaped cross section are adjacent to each other and the curved portions are continuously formed into a circle as shown in fig. 4(a), it is possible to arrange the coated wires 40 without a gap, and it is possible to reduce the diameter of the tube shield 40.

Further, if the heat dissipation sheet 50 is interposed between the covered wires 30, the heat dissipation is excellent. The distance between the wires of the wire harness of the present invention is close, and therefore, heat is less likely to be radiated at the side portions of the fan shape facing each other than at the curved portions or the like that are released to the outside. However, by interposing the heat sink 50 at the side portion, even if a plurality of covered wires are arranged in a bundle by a tube or the like, the influence of heat generation at the time of energization can be suppressed. In this case, for example, if the covered wires are bundled by using a highly heat conductive tube such as aluminum, heat can be radiated from both the side portion and the curved portion.

The wire harness of the present embodiment is excellent in wiring properties because of its space saving properties and excellent flexibility. This makes it easy to secure a sufficient wiring space, and therefore the conductor cross-sectional area can be increased, and the conductor can be suitably used as a power line of an electric vehicle or the like. In particular, when the power line is configured using the wire harness of the present embodiment, the wire conductor 10 is configured by a set of thin wires 1, and therefore the entire wire conductor 10 has high resistance to bending and vibration. Thus, fatigue failure due to engine vibration or the like is unlikely to occur.