CN114883034B

CN114883034B - Wire conductor, covered wire, and wire harness

Info

Publication number: CN114883034B
Application number: CN202210457231.XA
Authority: CN
Inventors: 大井勇人; 大塚保之; 田口欣司; 丹治亮
Original assignee: Sumitomo Wiring Systems Ltd; AutoNetworks Technologies Ltd; Sumitomo Electric Industries Ltd
Current assignee: Sumitomo Wiring Systems Ltd; AutoNetworks Technologies Ltd; Sumitomo Electric Industries Ltd
Priority date: 2016-11-08
Filing date: 2017-11-08
Publication date: 2024-03-15
Anticipated expiration: 2037-11-08
Also published as: JP2022159462A; CN112086223A; WO2018088419A1; CN114883034A; CN112086223B; CN112086224B; CN112086224A

Abstract

The invention provides a wire conductor which can achieve both flexibility and space saving, a covered wire provided with the wire conductor, and a wire harness. An electric wire conductor (10) is formed by stranded wires formed by twisting a plurality of wires (1) and has a flat section formed by a flat shape in a cross section intersecting the axis direction of the stranded wires. The void ratio, which is the proportion of voids not occupied by the wire rod in the cross section of the flat portion, is set to 17% or more. The wire conductor (10) and the insulator coating the outer periphery of the wire conductor (10) are also provided. A wire harness including such a covered wire is also provided.

Description

Wire conductor, covered wire, and wire harness

The present application is a divisional application of an invention patent application having a filing date of 2017, 11, 8, 202010789512.6 and a name of "wire conductor, covered wire, wire harness".

Technical Field

The present invention relates to a wire conductor, a covered wire, and a wire harness, and more particularly, to a wire conductor composed of twisted wires, a covered wire having an insulator on an outer periphery of the wire conductor, and a wire harness including the covered wire.

Background

Flat cables are known which are constructed using flat conductors. By using the flat cable, the space occupied in wiring can be reduced as compared with the case of using a normal electric wire having a conductor with a substantially circular cross section.

In a conventional flat cable, a flat rectangular conductor is often used as a conductor as described in patent document 1 and the like. The flat rectangular conductor is formed by forming a single wire of metal into a cross-sectional quadrangle.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open publication No. 2014-130739

Disclosure of Invention

Problems to be solved by the invention

The flat rectangular conductor has relatively high flexibility in a direction along a height (thickness) direction of a flat cross section, and is easily bent. However, since the flexibility is low and hard in the direction along the width direction of the flat cross section, it is difficult to bend. Thus, the flat cable having the flat rectangular conductor is difficult to bend in a specific direction, and workability in wiring is deteriorated.

The invention provides a wire conductor which can achieve both flexibility and space saving, and a covered wire or wire harness provided with such a wire conductor.

Means for solving the problems

In order to solve the above-described problems, the wire conductor according to the present invention is constituted by a stranded wire formed by twisting a plurality of wires, and has a flat portion having a flat cross section intersecting the axial direction of the stranded wire, wherein the ratio of voids not occupied by the wires, that is, the void ratio, is 17% or more in the cross section of the flat portion.

Here, the void ratio may be 40% or less.

The wire may have a smaller deformation ratio with respect to a circular shape in a cross section of the flat portion at a portion facing an outer periphery of the flat portion than at a central portion of the flat portion. Further, the deformation ratio of the wire rod with respect to the circular shape may be 50% or less at a portion facing the outer periphery of the flat portion at a central portion of the flat portion. Further, a deformation rate of the wire rod with respect to a circular shape in a cross section of the flat portion may be 10% or less at a portion facing an outer periphery of the flat portion.

The wire conductor may have a continuous space capable of accommodating two or more wires in a cross section of the flat portion.

The cross section of the flat portion may have opposite sides parallel to each other in the width direction of the flat shape. In this case, the deformation ratio of the wire rod with respect to the circular shape in the cross section of the flat portion may be smaller at the end portions of the opposite sides of the flat portion that are parallel to each other than at the central portion of the flat portion.

The length of the flat portion in the width direction of the flat shape may be 3 times or more the length of the flat portion in the height direction intersecting the width direction.

The flat portion may have a quadrangular cross section. The flat portion may have a rectangular cross section.

The electric wire conductor may have the flat portion and a low flat portion having a lower flatness than the flat portion continuously in the axial direction.

The number of wires constituting the twisted wire may be 50 or more.

The strands may be composed of copper or copper alloy and have a thickness of 100mm ² The above conductor cross-section, alternatively, is composed of aluminum or aluminum alloy and has 130mm ² The above conductor cross-sectional area.

In the wire conductor, the twisted wire may be rolled from a first direction and a second direction which are opposite to each other and a third direction and a fourth direction which intersect the first direction and the second direction and are opposite to each other at the flat portion.

The coated electric wire according to the present invention includes the electric wire conductor described above and an insulator coating an outer periphery of the electric wire conductor.

The wire harness according to the present invention includes the covered electric wire.

Here, the wire harness may include a plurality of the covered wires as described above, and the plurality of covered wires may be arranged along at least one of the width direction of the wire conductor and a height direction intersecting the width direction. In this case, the wire harness may have at least one of a heat sink interposed between the plurality of covered wires and a heat sink commonly contacting the plurality of covered wires. In addition, the plurality of covered wires may be arranged at least in the height direction. In this case, a clip made of a heat radiation material may be interposed between the plurality of covered wires arranged in the height direction, and a connecting member may be provided to connect the plurality of clip to each other and made of a heat radiation material.

The wire harness may be arranged along an outer periphery of the columnar member. Alternatively, the wire harness may be housed in a hollow portion of a hollow tubular member having an opening in a longitudinal direction.

Alternatively, the wire harness may be disposed under the floor of the automobile to constitute a power supply main line. Alternatively, the wire harness may constitute a ceiling or a floor of an automobile. In these cases, the wire harness may include a plurality of the above-described covered wires that are arranged at least in the width direction of the wire conductors, that are aligned in the height direction intersecting the width direction, and that are arranged between the interior component and the sound absorbing material of the automobile such that the width direction is along the surfaces of the interior component and the sound absorbing material.

The wire harness may include a first covered wire and a second covered wire, wherein the first covered wire is the covered wire in which the wire conductor is made of aluminum or an aluminum alloy, and the wire conductor of the second covered wire is made of copper or a copper alloy, and the wire conductor of the first covered wire has a lower flatness and a smaller conductor cross-sectional area than the wire conductor of the first covered wire. In this case, the conductor cross-sectional area of the second covered wire may be 0.13mm ² The following is given.

Effects of the invention

The electric wire conductor according to the above invention is not a single wire but is constituted by stranded wires, and thus has high flexibility. Further, by providing the flat portion having a flat cross section, the space required for wiring as an electric wire can be reduced as compared with a general electric wire conductor having a substantially circular cross section. Further, when the cross-sectional area of the conductor is increased, the width direction of the flat shape is widened, the dimension in the height direction can be suppressed to be small, and therefore the cross-sectional area can be increased while maintaining the space-saving property.

Further, the wire conductor according to the above invention has a void ratio of 17% or more, and thus, even if the cross section becomes flat, it is easy to maintain particularly high flexibility. As a result, the wire conductor having a particularly high degree of freedom in wiring is obtained.

Here, when the void ratio is 40% or less, the flat portion is easily formed into a sufficiently flat shape. In addition, the formed flat shape is easily maintained. Therefore, the space saving property of the wire conductor can be effectively improved.

When the deformation ratio of the wire rod in the cross section of the flat portion with respect to the circular shape is smaller at the portion facing the outer periphery of the flat portion than at the center portion of the flat portion, the wire rod located at the outer periphery of the stranded wire due to the stranded wire being formed flat in cross section is prevented from being intensively deformed, and a large load due to the deformation is received. In addition, the formation of a concave-convex structure such as a sharp protrusion on the outer peripheral portion of the wire conductor due to the deformation of the wire rod is prevented.

In the case where the deformation ratio of the wire rod with respect to the circular shape is 50% or less at the central portion of the flat portion at the portion facing the outer periphery of the flat portion, the above-described effect of preventing the deformation and the concentration of the load at the outer periphery of the stranded wire and also preventing the formation of the concave-convex structure on the surface of the wire conductor can be obtained particularly well.

Even when the deformation ratio of the wire rod with respect to the circular shape in the cross section of the flat portion is 10% or less at the portion facing the outer periphery of the flat portion, the above-described effect of preventing deformation and concentration of load at the outer periphery of the stranded wire and also preventing formation of the uneven structure on the surface of the wire conductor can be obtained particularly well.

When the wire conductor has a continuous space capable of accommodating two or more wires in a cross section of the flat portion, the wire conductor can be flexibly bent by movement of the wires into such a space, and therefore the effect of keeping the flexibility of the wire conductor high is particularly excellent.

In the case where the cross section of the flat portion has opposite sides parallel to each other in the width direction of the flat shape, a large space is easily secured outside the height (thickness) direction of the wire after wiring, and a high space saving can be achieved. In particular, when a plurality of wires are stacked and routed, a wasteful space is less likely to be generated.

In this case, in the case where the deformation ratio of the wire rod with respect to the circular shape in the cross section of the flat portion is smaller at the end portions of the opposite sides of the flat portion parallel to each other than at the center portion of the flat portion, deformation and load concentration at the end portions of the wire conductor can be prevented. Further, although the concave-convex structure such as the sharp protrusion tends to be formed easily at the end portions of the opposite sides parallel to each other in the outer peripheral portion of the wire conductor, the formation of the concave-convex structure such as the sharp protrusion at the end portion can be effectively prevented by suppressing the deformation rate of the wire rod at the end portion to be small.

In addition, when the length in the width direction of the flat shape of the flat portion is 3 times or more the length in the height direction intersecting the width direction, the wire conductor can be made to have both of ensured flexibility and high space saving in the height direction due to the height direction being smaller in size than the width direction.

In addition, when the flat portion has a quadrangular cross section, wasteful space generated between the wires when the plurality of wires are arranged in parallel and overlapped can be reduced, and the wires can be gathered at a high density.

Further, when the flat portion has a rectangular cross section, it is possible to reduce a wasteful space generated between the wires when the plurality of wires are arranged in parallel and overlapped, and the flat portion is particularly excellent in terms of space saving.

When the wire conductor has a flat portion and a low flat portion having a lower flatness than the flat portion continuously in the axial direction, the portions having different flatness can be provided in one wire conductor in the axial direction of the wire conductor without joining or the like, and the characteristics of the portions having different flatness can be utilized simultaneously. For example, by providing a flat portion at the center of the wire conductor and providing low flat portions having a substantially circular cross section at both ends thereof, space saving at the center and convenience in mounting members such as terminals at the ends can be achieved.

When the number of wires constituting the stranded wire is 50 or more, a large gap is left between the wires by changing the relative arrangement of the wires without largely deforming the wires, and the stranded wire is easily formed to have a flat cross section. Therefore, the electric wire conductor is easy to achieve both space saving and flexibility.

In twisted wires consisting of copper or copper alloy and having a thickness of 100mm ² The above conductor cross-section, alternatively, is composed of aluminum or aluminum alloy and has 130mm ² The conductor cross-sectional area can be particularly as followsThe effect of achieving both space saving and flexibility by adopting the cross-sectional flat shape is effectively utilized. At 100mm ² Above 130mm ² In the wire conductor having such a large cross-sectional area, when the cross-section is substantially circular, a large wiring space is required due to the size of the diameter thereof, and repulsive force against bending is large. However, in such a large-cross-sectional-area wire conductor, the space can be saved by forming the cross section into a flat shape, and high flexibility can be obtained particularly in bending in the height direction.

Further, when the twisted wire is rolled from the first direction and the second direction which face each other and the third direction and the fourth direction which intersect the first direction and the second direction and face each other at the flat portion, the wire conductor is easily configured to be close to a cross-sectional quadrangle, and the wire conductor is excellent in space saving.

The coated electric wire according to the present invention has the above-described electric wire conductor, and therefore, can achieve both flexibility achieved by the stranded wire structure of the electric wire conductor and space saving achieved by the flat shape. Therefore, on the premise that a plurality of covered wires are wired in parallel or overlapping, wiring can be performed while having a high degree of freedom and reducing space.

The wire harness according to the present invention is configured to include the covered electric wire having the flat electric wire conductor, and therefore is excellent in flexibility and space saving, and can be suitably used as a wiring material in a limited space such as an automobile.

Here, in the case where the wire harness includes a plurality of the above-described covered wires and the plurality of covered wires are arranged along at least one of the width direction of the wire conductor and the height direction intersecting the width direction, the space between the plurality of covered wires can be suppressed to be small to construct the wire harness, and thus, a particularly high space saving can be achieved.

In this case, according to the structure in which the wire harness has at least one of the heat radiating fin interposed between the plurality of covered wires and the heat radiating fin commonly contacting the plurality of covered wires, even if the plurality of covered wires are arranged close to each other at a high density by utilizing the space saving property achieved by the flat shape, the influence due to heat generation at the time of energization can be suppressed to a small extent.

In addition, when a plurality of covered wires are arranged at least in the height direction, various small spaces such as elongated gaps can be effectively and flexibly applied to the wiring of the covered wires by the arrangement of the covered wires in the height direction.

In this case, when the clip made of the heat radiation material is interposed between the plurality of covered wires arranged in the height direction, and the connector made of the heat radiation material is provided to connect the plurality of clip to each other, the plurality of covered wires are adjacent to each other so that flat wide surfaces face each other, and heat generated at the time of energization is easily dissipated to the outside of the array of covered wires, but the provision of the clip makes it easy to efficiently dissipate heat generated at the time of energization to the outside. In addition, by providing a connecting member for connecting the plurality of clip pieces, heat can be more effectively emitted.

When the wire harness is arranged along the outer periphery of the columnar member or when the wire harness is accommodated in a hollow portion of a hollow tubular member having an opening in the longitudinal direction, the columnar member and the tubular member constituting a body or the like of an automobile are used for supporting the wire harness, so that the wiring space of the wire harness can be effectively reduced.

In addition, when the wire harness is disposed under the floor of the automobile and constitutes the power supply main line, productivity can be improved and occurrence of fatigue failure due to engine vibration or the like can be suppressed as compared with a conventional power supply main line using a general copper plate.

Alternatively, when the wire harness constitutes a ceiling or a floor of the automobile, the space can be used in the automobile in particular without wasting the space to ensure the wiring path, and high heat dissipation can be achieved even when a large current flows. Further, depending on the arrangement of the covered wires, various shapes of ceiling surfaces and floor surfaces can be configured.

In these cases, according to the structure in which the wire harness includes the plurality of covered wires that are arranged at least in the width direction of the wire conductors, that are aligned in the height direction intersecting the width direction, and that are arranged between the interior component and the sound absorbing component of the automobile so that the width direction is along the surfaces of the interior component and the sound absorbing component, the distance between the interior component and the sound absorbing component can be kept small, and the space between the interior component and the sound absorbing component can be effectively used for wiring of the wire harness. In this case, the height of the plurality of covered wires is made uniform, so that the uneven structure of the covered wires is less likely to affect the surface shape of the interior material and the sound absorbing performance of the sound absorbing material.

Further, when the wire harness includes the first covered wire and the second covered wire, the first covered wire is the covered wire in which the wire conductor is made of aluminum or an aluminum alloy, and the wire conductor of the second covered wire is made of copper or a copper alloy, the wire conductor of the first covered wire has a lower flatness and a smaller conductor cross-sectional area than the wire conductor of the first covered wire, and the space saving of the first covered wire and the utilization of characteristics such as high conductivity of copper or a copper alloy in the second covered wire, which tend to have a large area due to a lower conductivity of aluminum or an aluminum alloy, can be achieved.

In this case, if the conductor cross-sectional area of the second covered wire is 0.13mm ² In the following, the harness as a whole is easy to ensure high space saving.

Drawings

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

Fig. 2 is a cross-sectional view of the wire conductor.

Fig. 3 is a cross-sectional view illustrating rolling of the raw material strand.

Fig. 4 is a view showing various cross-sectional shapes of the wire conductors, and (a) to (d) show different modes. The wires are omitted in (b) to (d).

Fig. 5 is a cross-sectional view showing an example of arrangement of covered wires in a wire harness according to an embodiment of the present invention. (a) The case where the covered wires are arranged in the width direction is shown, and (b) the case where the covered wires are arranged in the height direction is shown.

Fig. 6 is a cross-sectional view showing another mode of arranging coated wires in the width direction.

Fig. 7 is a diagram showing an example of a wiring structure of a wire harness, (a) shows a wiring structure using a cylindrical member, and (b) shows a wiring structure using a tubular member having a cross section shape.

Fig. 8 is a photograph taken of a cross section of a coated wire, (a) shows a raw material strand before rolling, (b) shows sample 1 having a low compression ratio, and (b) shows sample 2 having a high compression ratio.

Fig. 9 is a result of a simulation relating to the temperature rise of the covered electric wire.

Detailed Description

The wire conductor, the covered wire, and the wire harness according to one embodiment of the present invention will be described in detail below with reference to the drawings. The structure in which the outer periphery of the wire conductor according to the embodiment of the present invention is covered with the insulator corresponds to the covered wire according to the embodiment of the present invention. The structure in which a plurality of covered wires including the covered wire according to the embodiment of the present invention are gathered corresponds to the wire harness according to the embodiment of the present invention.

[ electric wire conductor ]

Fig. 1 is a perspective view showing an external appearance of a wire conductor 10 according to an embodiment of the present invention. Fig. 2 shows a cross section of the wire conductor 10 perpendicular to the axial direction (longitudinal direction).

(1) Cross-sectional shape of wire conductor

The wire conductor 10 is constituted as a stranded wire formed by stranding a plurality of wires 1. Further, the wire conductor 10 has a flat outer shape at least at a portion in the axial direction. That is, the wire conductor 10 has a flat portion formed in a flat shape in cross section perpendicular to the axial direction. In the present embodiment, the entire area in the axial direction of the wire conductor 10 is formed as such a flat portion.

Here, the cross section of the wire conductor 10 has a flat shape, and is a state in which the length, i.e., the width W, of the longest straight line among straight lines intersecting the cross section in parallel with the sides constituting the cross section and including the entire cross section in the range is larger than the length, i.e., the height H, of a straight line orthogonal to the straight line and including the entire cross section in the range. In the cross section of the wire conductor 10 according to the present embodiment shown in fig. 2 and the cross section of the wire conductor according to each embodiment shown in fig. 4, the width W is larger than the height H.

The cross section of the wire conductor 10 may be any specific shape as long as it has a flat shape, but in the present embodiment, the cross section of the wire conductor 10 has opposite sides 11, 12 parallel to each other in the direction of the width W of the flat shape (width direction x). That is, two straight lines 11 and 12 can be drawn in parallel with the width direction x by being circumscribed on the wire 1 outside the cross section of the wire conductor 10. In the present specification, the concept of the relationship between the wire and the surface, such as the shape of the wire conductor 10, the parallelism, the verticality, and the like, includes errors from the geometric concept, such as the deviation of the angle of approximately ±15°, the R shape formed by chamfering the corners, and the like. The concepts of sides, straight lines, planes, and the like also include curves and curved surfaces having an angle of approximately 15 ° with respect to a geometric straight line or plane.

In the present embodiment, the cross section of the wire conductor 10 is formed of a rectangle. In the figure, the number of wires 1 constituting the wire conductor 10 is reduced for easy understanding.

The wire conductor 10 according to the present embodiment has a flat cross section, and thus, when wiring in the form of a covered wire or the like, the space required for wiring can be reduced as compared with a wire conductor having a cross section with the same conductor cross section and a substantially circular cross section. That is, the space in which other wires and other members cannot be arranged around a certain wire can be reduced. In particular, the space occupied by the electric wire in the height direction y can be reduced, and space saving can be easily achieved. As a result, it is easy to dispose other wires and other members in the space outside the wires in the height direction up and down (±y direction). For example, when wiring the electric wire so as to be along the wiring surface, if the flat surface of the electric wire, that is, the surface parallel to the width direction x is made to be along the wiring surface, a space is easily secured above the electric wire (in the direction opposite to the wiring surface via the electric wire). In addition, even when the conductor cross-sectional area of the wire conductor 10 needs to be increased, the space saving property in the height direction y can be maintained by increasing the width W while maintaining the small height H.

In particular, when the wire conductor 10 has the opposite sides 11, 12 parallel to the width direction x in the cross section, a wide space can be ensured in the height direction of the wire after wiring (y direction), and the space saving is excellent. In particular, when a plurality of electric wires are gathered so as to overlap other electric wires above one electric wire, gaps generated between the plurality of electric wires in the height direction y can be reduced. The term "collecting the plurality of electric wires" includes both a case where the plurality of electric wires are integrated by an insulating material or the like and a case where the plurality of independent electric wires are arranged in close proximity.

In addition, when the wire conductor 10 has a rectangular cross section, a wide space can be ensured in the up-down direction (±y direction) and the side direction (±x direction) of the wire conductor 10, and the space saving can be further improved. In particular, when a plurality of wires are gathered so that other wires are overlapped on top of one wire and so that other wires are arranged laterally of one wire, gaps generated between the plurality of wires in the height direction y and the width direction x can be reduced.

As described above, the wire conductor 10 according to the present embodiment is constituted by the stranded wire formed by twisting the plurality of wires 1, and the stranded wire has a flat outer shape. Thus, the wire conductor 10 has high flexibility in all directions. A flat rectangular conductor as shown in patent document 1 shows some degree of flexibility in the height direction of the flat shape, but has low flexibility in the width direction and is hard in the width direction and difficult to bend. In contrast, the wire conductor 10 according to the present embodiment, which is made of twisted wire, has high flexibility in the width direction x as well as the height direction y, and is easily bent.

As described above, the wire conductor 10 according to the present embodiment combines flexibility in wiring and space saving. For example, in automobiles, the number of wires and components to be installed is increasing due to recent high-functionality. In addition, in electric vehicles and the like, a large current is being driven, and the wire diameter is also becoming large. Therefore, the space in which each wire can be wired is being reduced. However, if the wire conductor 10 according to the present embodiment is used, the wiring of the electric wire can be performed by effectively utilizing a small space by utilizing space saving property and flexibility. The effect is particularly great in the case of gathering a large number of wires and in the case of using wires having a large conductor cross-sectional area.

In the present embodiment described so far, the wire conductor 10 has a rectangular cross section. However, as described above, the wire conductor 10 may have any shape as long as the cross section thereof is flat. Fig. 4 (b) to (d) show other examples of the cross-sectional shape. In these drawings, the wire 1 is omitted, and only the outline of the cross section, that is, the circumscribed pattern similar to the cross section of the entire wire conductor is shown. Fig. 4 (b) shows a cross section of an ellipse (a shape having a semicircle at both ends of a rectangle). As a cross section of a quadrangle other than the rectangle described above, fig. 4 (c) shows a trapezoid cross section, and fig. 4 (d) shows a parallelogram cross section. The wire conductors 10 have a quadrangular cross section, and thus a large number of wire conductors 10 can be arranged with small gaps in the height direction y and the width direction x, and space saving is excellent when a large number of wires are gathered. As described above, this effect is particularly remarkable when the cross-sectional shape is rectangular.

(2) Voids in the profile of a wire conductor

The wire conductor 10 according to the present embodiment has a void ratio of 17% or more in the cross section of the flat portion. The void ratio in the cross section of the wire conductor 10 is defined as a ratio of the area occupied by the wire conductor 10 as a whole, that is, the area of the void not occupied by the wire 1 in the area surrounded by the outer contour of the wire conductor 10 as a whole, in the cross section of the wire conductor 10 intersecting perpendicularly to the axial direction.

As described above, the wire conductor 10 has high flexibility in both the height direction y and the width direction x due to the effect of the flat shape, and is easily bent. In the cross section of the wire conductor 10, sufficient gaps are ensured such as 17% or more, so that when the wire conductor 10 is bent in the height direction y and the width direction x, the wire conductor 10 is easily and smoothly bent due to the movement of the wire 1 using the gaps in the wire conductor 10, and the flexibility of the wire conductor 10 is easily improved. From the viewpoint of further improving flexibility, it is more preferable that the void ratio is 20% or more and 25% or more.

The upper limit of the void ratio is not particularly limited, but is preferably 40% or less from the viewpoint of easy shaping of the wire conductor 10 into a flat shape by rolling or the like and easy maintenance of the formed flat shape. When the content is 35% or less, it is more preferable.

In the cross section of the wire conductor 10, a small gap is formed in the region between the wires 1. The void ratio defined above is a ratio of the total area of these small voids to the area occupied by the cross section of the wire conductor 10, and the flexibility of the wire conductor 10 is improved by making the total area of these voids occupy a predetermined ratio or more in the cross section of the wire conductor 10, but the size of the area of each void formed in the region between the wires 1 contributes to the improvement of the flexibility of the wire conductor 10. That is, the presence of voids having a certain size as a continuous region is effective for improving the flexibility of the wire conductor 10, as compared with the case where the fine voids are dispersed throughout the cross section of the wire conductor 10. Specifically, it is preferable that the cross section of the wire conductor 10 has a continuous space capable of accommodating two or more wires 1, or even three or more wires. This is because the wire 1 is moved to such a large gap, thereby assisting in soft bending of the electric wire. As the wire 1 for determining whether or not the space can be accommodated therein, a wire 1 surrounding the space of interest or a wire having a circular cross section and having the same cross section as any wire 1 constituting the wire conductor 10 may be used. For example, in fig. 4 (a), two or more wires can be accommodated in the gap indicated by the reference numeral v.

The wire conductor 10 or the covered wire 20 having the insulator 21 provided on the outer periphery thereof is cut or polished to obtain a cross section, and the cross section is subjected to actual measurement such as photographing, whereby the area of the wire conductor 10 and the space can be evaluated. In this case, the wire conductor 10 and the covered wire 20 may be appropriately embedded in a transparent resin or the like, and then subjected to an operation such as cutting so that the shape and area of the space do not change due to the operation such as cutting. The areas of the wire conductor 10 and the voids may be evaluated on the entire cross section of the wire conductor 10, or the areas of the wire conductor 10 and the voids may be evaluated on the inner side of the wire conductor 10 excluding the outermost periphery, instead of the entire cross section, in the case where the number of wires 1 is sufficiently large, for example, 50 or more, in order to eliminate the influence of the uneven structure or the like on the outermost periphery of the wire conductor 10.

(3) Cross-sectional shape of each wire rod

In the electric wire conductor 10 according to the present embodiment, the cross-sectional shape of each wire 1 constituting the electric wire conductor 10 may be any shape as long as the cross-section is flat as the outer shape of the electric wire conductor 10 as a whole. A general metal wire rod has a substantially circular cross section, and such a wire rod 1 can be applied to the present embodiment. However, at least a part of the plurality of wires 1 may have a cross section of a flat shape or the like out of a circular shape. As described later, when the raw material strand 10' is rolled to be flat, at least a part of the wire 1 may be deformed into a flat shape by a material or the like constituting the wire 1.

In the electric wire conductor 10 according to the present embodiment, in a cross section perpendicular to the axial direction, the deformation rate of the wire 1 is smaller at the outer peripheral portion of the electric wire conductor 10 facing the outer periphery than at 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 rod 1.

Here, the deformation ratio of the wire rod 1 is an index indicating to what extent a certain wire rod 1 has a cross section departing from a circular shape. In a case where the length of the longest straight line intersecting the cross section of a certain wire 1 actually included in the wire conductor 10 is the major axis a, and the diameter of a circle having the same area as the cross section of the wire 1 is the circle diameter R, the deformation rate D of the wire 1 can be expressed as follows.

D＝(A-R)/R×100％(1)

The round diameter R may be calculated by measuring the cross-sectional area of the actual wire rod 1, or when the diameter of the wire rod 1 before receiving the deformation by rolling or the like is known, and when the undeformed portions (hereinafter, referred to as low-flat portions) of the wire rod 1 coexist in the same wire conductor 10, the diameter of the wire rod 1 that does not receive the deformation may be used as the round diameter R. Further, as the wire 1 in the outer peripheral portion, only the wire 1 disposed in the outermost periphery of the wire conductor 10 may be used, and as the wire 1 in the central portion, only the wire 1 disposed in the center of the conductor may be used, but from the viewpoint of reducing the influence of the variation in the deformation of the wire 1 or the like, it is preferable to estimate the deformation ratio as an average value of the plurality of wires 1 included in the region of a certain degree of area. For example, a region surrounded by a quadrangle having a side with a length of about 10 to 30% of the width W of the wire conductor 10 and a circle having a diameter of such a length may be set so as to include the outermost periphery or the center of the wire conductor 10, and these regions may be used as the outer periphery and the center, respectively.

The wire conductor 10 according to the present embodiment has a flat cross-sectional shape, but if the wire 1 positioned at the outer peripheral portion in the up-down direction (±y direction) of the wire conductor 10 in the cross-section is deformed to be flat, the flat cross-sectional shape can be formed more efficiently than if the wire 1 at the central portion is deformed. However, when the wire rod 1 on the outer peripheral portion is deformed intensively in this way, the load concentrates on the wire rod 1 on the outer peripheral portion, and the physical properties of the wire rod 1 are greatly different in the outer peripheral portion of the wire conductor 10 from those in the inner region thereof. In addition, the shape of the wire 1 in the outer peripheral portion of the wire conductor 10, particularly the wire 1 located at the outermost periphery of the wire conductor 10 defines the outline shape of the entire wire conductor 10, and if these wires 1 are greatly deformed, there is a possibility that an unnecessary uneven structure is caused to the surface shape of the wire conductor 10. Such a concave-convex structure may be a sharp protrusion (burr) which may be formed when the raw material strand 10' is processed into a flat shape. Burrs are particularly liable to form at the widthwise ends (±x direction) of the wire conductor 10.

Therefore, in the wire conductor 10, 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 avoid a case where the load due to the deformation is concentrated on the wire 1 in the outer peripheral portion as described above, and a case where an unnecessary uneven structure is formed on the outer periphery of the wire conductor 10. In the wire conductor 10 according to the present embodiment, as described above, a void ratio of 17% or more is ensured, and the wires 1 can take various relative arrangements by using the voids between the wires 1, so that the cross section of the wire conductor 10 can be formed into a desired flat shape by using the relative arrangement of the wires 1 without largely deforming the shape of each wire 1 itself.

From the viewpoint of effectively avoiding concentration of deformation and load of the wire 1 located at the outer peripheral portion of the wire conductor 10 and formation of an unnecessary uneven structure on the surface of the wire conductor 10, the ratio of the deformation rate of the wire 1 at the outer peripheral portion to the deformation rate of the wire 1 at the central portion (outer Zhou Bianxing ratio; outer peripheral portion deformation rate/central portion deformation rate×100%) is preferably 70% or less, more preferably 50% or less, 25% or less. The deformation ratio of the wire 1 in the outer peripheral portion is preferably 10% or less, more preferably 5% or less. The lower limit is not particularly set, and the smaller the deformation ratio of the wire 1 in the outer peripheral portion is, the more preferable.

The deformation ratio of the wire rod 1 in the central portion is not particularly limited, but is preferably 50% or less, more preferably 30% or less, from the viewpoint of avoiding the application of a load to the wire rod 1 due to excessive deformation. On the other hand, from the viewpoint of effectively forming the cross section of the wire conductor 10 into a flat shape while suppressing the deformation of the wire rod 1 at the outer peripheral portion to be small, the deformation rate of the central portion is preferably 10% or more, and more preferably 20% or more.

In the case where the cross section of the wire conductor 10 has the opposite sides 11 and 12 parallel to the width direction x, particularly in the case where the cross section is formed of a rectangle, it is preferable that the deformation rate of the wire 1 be suppressed to be particularly small at the width direction end portions of the cross section, that is, the both end portions of the opposite sides 11 and 12 parallel to each other. This is because, when the cross section of the wire conductor 10 is formed into these shapes, the deformation rate of the width-direction end portion tends to be increased for the purpose of forming the parallel opposite sides 11, 12 along the width direction x and the angle structure close to a right angle. In addition, at the end portion, sharp burrs are easily formed when processing for shaping the wire conductor 10 is performed by compression or the like of the raw material stranded wire 10'. From the viewpoint of avoiding these phenomena, in the cross section of the wire conductor 10, the deformation ratio of the wire 1 at the outer peripheral portion, particularly at the end portion, is preferably 70% or less, more preferably 50% or less, and even more preferably 25% or less, of the deformation ratio of the wire 1 at the central portion. The deformation ratio of the wire 1 at the end is preferably 10% or less, more preferably 5% or less. In addition, in the outer peripheral portion, when the deformation ratio of the wire 1 is compared between the end portion and the portion from which the end portion is removed, that is, the portion corresponding to the middle portion of the opposite sides 11, 12 in the width direction x, the deformation ratio of the end portion is preferably smaller than the deformation ratio of the side portion. That is, the deformation ratio of the wire 1 is preferably, from small to large, end portions, side portions, and a central portion in this order.

In the wire conductor 10, the larger the number of wires 1, the smaller the deformation ratio of the wires 1 in the outer peripheral portion is compared with the central portion, while maintaining a high void ratio of 17% or more, and the cross section is easily formed into a flat shape. For example, if the number of wires 1 is 50 or more, such a state is easily achieved by the diversity of the mutual arrangement of the wires 1. On the other hand, if the number of wires 1 is less than 50, even if the outer wires 1 are deformed to the same extent as or a larger deformation rate than the wires 1 in the central portion, a void ratio of 17% or more is preferably ensured from the viewpoint of sufficiently obtaining flexibility of the wire conductor 10.

(4) Material and conductor cross-sectional area of wire conductor

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 suitable for forming the wire conductor 10 according to the present embodiment in that the wire is easily formed into a flat shape by rolling and the flat shape is easily maintained. As the wires 1 constituting the wire conductor 10, wires made of the same material may be used in their entirety, or a plurality of wires 1 made of different materials may be used in combination.

The conductor cross-sectional area of the wire conductor 10 may be arbitrarily selected according to a desired conductivity or the like. However, the larger the conductor cross-sectional area is, the easier it is to form a flat shape by rolling or the like, and the more easily it is to firmly maintain the temporarily formed flat shape. From these viewpoints, when the wire 1 constituting the wire conductor 10 is made of copper or copper alloy, the wire can be exemplified as 16mm in terms of an appropriate conductor cross-sectional area ² In the above, when the material is made of aluminum or aluminum alloy, it can be exemplified by 40mm ² The above.

Furthermore, the cross-sectional area of the conductor is 100mm ² In such a large region, when the cross section of the wire conductor is substantially circular, a large space is required for wiring because the diameter of the circle of the cross section is large, and the repulsive force when bending is applied is large, so that it is difficult to secure sufficient flexibility for wiring. However, by forming the wire conductor 10 having a flat cross section, the height H can be reduced as compared with a wire conductor having the same cross section as the conductor and a substantially circular cross section. This reduces the space occupied by the wire conductor 10 in the height direction y, reduces the repulsive force when bending the wire conductor 10 in the direction along the height direction y, and easily ensures flexibility required for wiring. By forming the wire conductor 10 having a large conductor cross-sectional area into a cross-sectional flat shape, the effect of improving the heat dissipation of the wire conductor 10 can be obtained. From the viewpoint of effectively utilizing these effects of securing flexibility and the like, in the case where the wire conductor 10 is composed of copper or copper alloy, the conductor cross-sectional area is preferably 100mm ² The above. In the case where the wire conductor 10 is composed of aluminum or an aluminum alloy, it is further preferable that the conductor cross-sectional area is 130mm ² The above. The wire conductor 10 having a large conductor cross-sectional area can be expected to be used as a power supply wire or the like in a high-power electric vehicle, and the space-saving property and flexibility of the wire conductor 10 having a flat cross-sectional shape are useful in accordance with the necessity of wiring in a limited space in the vehicle. In particular, from the viewpoint of weight reduction of the vehicleThe wire conductor 10 having a large conductor cross-sectional area is effectively made of aluminum or an aluminum alloy, but since aluminum or an aluminum alloy has lower conductivity than copper or a copper alloy, it is required to be 130mm, for example, from the viewpoint of securing the required conductivity ² The above is particularly applicable to the wire conductor 10 having a large conductor cross-sectional area.

Further, as an appropriate outer diameter of each wire 1 constituting the wire conductor 10, 0.3 to 1.0mm can be exemplified. The number of wires 1 constituting the wire conductor 10 is determined by the conductor cross-sectional area of the wire conductor 10 and the outer diameter of the wire 1 used. However, as the number of wires 1 increases, the wires 1 can be arranged in various opposite directions, so that it is easy to ensure a large void ratio of 17% or more, and further, the deformation ratio of the wires 1 in the outer peripheral portion of the wire conductor 10 is suppressed to be small, and the wire conductor 10 is formed into a cross-sectional flat shape. From this viewpoint, the number of wires 1 is preferably 50 or more, more preferably 100 or more and 500 or more.

(5) Aspect ratio of wire conductor

In the cross section of the wire conductor 10, the aspect ratio (H: W) of the flat shape may be appropriately selected in consideration of desired space saving property or the like, but can be exemplified as 1: 2-1: about 8. If the amount is within this range, the twisted wire can be smoothly formed into a flat shape, and a high space saving property can be ensured. In addition, when the wire conductor 10 is used as a wiring in an automobile, a preferable embodiment is a method in which the height H is 3mm or less.

As will be described later, when the wire conductor 10 having a flat cross section is formed by rolling the raw material strand 10' composed of a normal strand having a substantially circular cross section, the voids between the wires 1 tend to be smaller with the rolling, and particularly, the void ratio tends to be smaller as the aspect ratio of the flat shape of the wire conductor 10 is larger (as the width W is larger than the height H). However, for example, at an aspect ratio (H: W) of 1: when the width W of the wire conductor 10 is 3 or more, that is, 3 times or more the height H, as described above, if the void ratio is ensured to be 17% or more, it is easy to achieve both high space saving and flexibility in the wire conductor 10.

Further, by forming the wire conductor 10 in a cross-sectional flat shape, the heat radiation performance of the wire conductor 10 can be improved by the effect of the surface area being increased as compared with the case where the cross section is substantially circular. As a result, even if the same current flows, the temperature rise of the wire conductor 10 can be reduced when the wire conductor 10 has a flat cross section as compared with when the wire conductor 10 has a circular cross section. In other words, when the upper limit value of the temperature rise is defined, the temperature rise can be suppressed within the range of the upper limit value and the same amount of current can be applied to the wire conductor 10 having a flat cross section, compared to the case where the wire conductor 10 has a substantially circular cross section. The larger the aspect ratio of the wire conductor 10 is, the higher the effect of improving the heat dissipation property is. For example, as shown in the following embodiment, if the aspect ratio is set to 1:3 or more, the temperature rise at the time of energization can be suppressed to the same extent even if the conductor cross-sectional area of the wire conductor 10 is set to about 90% of the cross-sectional area of the wire conductor having a substantially circular shape. Further, the aspect ratio is preferably set to 1:5 or more.

(6) Other modes

Up to this point, a structure in which the entire axial region of the wire conductor 10 is constituted by a flat portion having a flat cross section has been used. However, the flat portion may occupy only a partial area in the axial direction of the wire conductor 10. That is, a mode in which flat portions and low-flat portions having a lower flatness (a smaller value of W/H) than the flat portions are provided adjacent to each other in the axial direction of the wire conductor 10 can be exemplified. Between the flat portion and the low flat portion, all the wires 1 are continuous as one body, and the cross-sectional shape of the electric wire conductor 10 varies as a whole. As the low flat portion, a structure having a substantially circular cross section with a flatness of substantially 1 can be exemplified. By providing the flat portion and the low flat portion in one wire conductor 10 in succession, the wire conductor 10 having the characteristics of the respective portions in combination can be obtained without joining or the like.

In the low flat portion, the deformation ratio of the wire 1 is preferably lower than that of the flat portion, corresponding to a case where the degree of flattening of the wire conductor 10 by rolling or the like is low. In particular, in the low flat portion having a substantially circular cross section and a flatness of 1 in practice, the wire 1 is preferably also substantially circular in cross section.

The flat portions and the low flat portions may be arranged in any order along the axial direction of the wire conductor 10, but as a preferable embodiment, a mode in which the flat portions are provided at the central portion in the axial direction and low flat portions having a substantially circular cross section or the like are provided at both ends thereof may be exemplified. In this case, it is considered to use the flat portion for wiring to a small space and to mount other members such as terminals to the low flat portions at both ends. In this way, the space saving property and flexibility of the flat portion and the convenience of mounting other members by the circular shape of the low flat portion or the cross-sectional shape similar thereto can be utilized at the same time. In the flat portion, a plurality of portions having different flatness may be provided adjacent to each other.

[ method for producing wire conductor ]

As shown in fig. 3, the wire conductor 10 according to the present embodiment can be formed by rolling a raw material stranded wire 10' formed by twisting a plurality of wires 1 in a substantially circular cross section. At this time, the raw material strand 10 'is compressed by applying forces F1, F2 from first and second directions opposite to each other perpendicular to the axial direction of the raw material strand 10', whereby a flat wire conductor 10 having the direction of application of the forces F1, F2 as the height direction y can be obtained.

Further, in addition to the forces F1, F2 from the first direction and the second direction, forces F3, F4 are applied to the raw material stranded wire 10' from the third direction and the fourth direction intersecting the first direction and the second direction and opposing each other, so that the obtained wire conductor 10 is easily shaped into a cross-sectional quadrangle. In particular, by applying forces F3, F4 from directions perpendicular to the forces F1, F2, the obtained wire conductor 10 is easily shaped into a cross-sectional rectangle. In these cases, by making the forces F1, F2 larger than the forces F3, F4, the wire conductor 10 having high flatness (large value of W/H) can be obtained. Further, although the forces F1, F2 and the forces F3, F4 can be applied simultaneously, by applying the forces F1', F2' again from the same direction as that after the forces F1, F2 are initially applied and simultaneously applying the forces F3, F4, it is possible to obtain the electric wire conductor 10 which is highly flattened and is well shaped into a cross-sectional quadrangle (particularly, a rectangle). When the flatness is changed in the axial direction of the wire conductor 10, the applied force may be changed in the middle of rolling in the axial direction.

The force applied to the raw material strand 10 'may be applied, for example, by arranging rollers in opposition and passing the raw material strand 10' between the rollers. By rolling the raw material strand 10' so as to be pushed out in the rotational direction of the roller by using the roller, the outer shape of the whole raw material strand 10' is easily deformed into a flat shape without applying a large load to the raw material strand 10', compared with a case where the raw material strand 10' is compressed by drawing by using an extrusion die, or a case where the raw material strand 10' is compressed in a flattened manner by using a press machine, for example. Further, the load is not concentrated on the outer peripheral portion of the raw material strand 10 'in contact with the roller, and the load is easily applied to the entire raw material strand 10' with high uniformity. As a result, by rolling the raw material strand 10' using the rolls, it is easy to secure a gap between the wires 1 in the obtained wire conductor 10 having a flat cross section, as compared with the case of using an extrusion die or a press. In addition, the deformation rate of each wire 1, for example, the wire 1 located at the outer peripheral portion of the wire conductor 10 is easily suppressed to be small. The porosity and the deformation ratio of each wire rod 1 can be adjusted by the magnitudes of the forces (F1, F2, F3, F4, F1', F2 ') applied during rolling and the shape of the portion of the roller in contact with the raw material strand 10 '.

The use of the rolls suppresses the deformation ratio of the wire rod 1 to a small value and shapes the entire raw material stranded wire 10' into a flat shape, so that the change in physical properties due to the deformation of the wire rod 1 can be suppressed to a small value in the obtained wire conductor 10. Therefore, in the wire conductor 10 after rolling, heat treatment or the like for removing the influence of work deformation or work hardening is not particularly required in many cases.

[ covered wire ]

As described above, the covered wire 20 according to the embodiment of the present invention includes the wire conductor 10 according to the embodiment of the present invention and the insulator 21 (see fig. 5, etc.) covering the outer periphery of the wire conductor 10.

The outer shape of the whole covered wire 20 including the insulator 21 reflects the outer shape of the wire conductor 10, and by making the wire conductor 10 have a flat shape, the covered wire 20 also has a flat shape. In addition, by making the wire conductor 10 highly flexible in all directions, the covered wire 20 also has high flexibility in all directions.

The material of the insulator 21 is not particularly limited, and may be composed of various polymer materials. In addition, the polymer material can be appropriately provided with a filler and an additive. However, the material and thickness of the insulator 21 are preferably selected in such a way that the flexibility of the insulator 21 is higher than the flexibility of the wire conductor 10 so as not to impair the high flexibility of the wire conductor 10. The thickness of the insulator 21 is preferably selected so that the flat shape of the wire conductor 10 is sufficiently reflected in the shape of the whole covered wire 20 and the cross section of the whole covered wire 20 has a flat shape.

The insulator 21 can be formed integrally around the entire circumference of the wire conductor 10. In this case, the insulator 21 can be provided by molding a polymer material or the like serving as the insulator 21 over the entire circumference of the wire conductor 10 by pressing. Alternatively, the sheet-like insulator 21 may be provided so as to sandwich the wire conductor 10 up and down (y direction) from the height direction of the wire conductor 10. In this case, two sheets of polymer material formed into a sheet shape may be disposed on the upper and lower sides of the wire conductor 10, and the sheets may be joined by welding, adhesion, or the like as appropriate.

The covered wire 20 may be used in a state of a single wire in which the outer periphery of the single wire conductor 10 is covered with the insulator 21, or may be used in a mode of a wire harness in which a plurality of covered wires are gathered and then, if necessary, the plurality of covered wires are integrally gathered using a covering material or the like. The case of using the wire harness will be described below.

[ wire harness ]

The wire harness according to one embodiment of the present invention is formed by aggregating a plurality of covered wires, at least a part of which is constituted by the covered wire 20 according to the embodiment of the present invention having the flat wire conductor 10 described above. The wire harness may be constituted by using only the covered wire 20 having the flat wire conductor 10 described above, or may be constituted by using such a covered wire 20 and other kinds of covered wires such as a covered wire having a general wire conductor having a substantially circular cross section. In the case where a wire harness is configured using a plurality of covered wires 20 having flat wire conductors 10, the wire conductors 10 and insulators 21 configuring the plurality of covered wires 20 may be the same or different in material, shape, size, and the like. In the wire harness, a plurality of covered wires that are gathered may be integrated by using an insulating material or the like as necessary.

(1) Arrangement of covered wires in wire harness

When a wire harness is configured using a plurality of covered wires 20 having flat wire conductors 10, these plurality of covered wires 20 may be arranged in any positional relationship, but a manner in which the covered wires are arranged in the width direction x (transverse direction) of the flat wire conductors 10 as shown in fig. 5 (a), a manner in which the covered wires are overlapped in the height direction y as shown in fig. 5 (b), or a manner in which a structure in which the covered wires 20 are arranged in the width direction x is overlapped in a plurality of matrix shapes in the height direction y (see fig. 7 (b)) can be exemplified. That is, a mode in which a plurality of covered wires 20 are arranged in at least one of the width direction x and the height direction y can be exemplified. By arranging the plurality of covered wires 20 having the flat wire conductors 10 in order in this way, the space between the covered wires 20 constituting the wire harness can be reduced, and the wire harness excellent in space saving in particular can be obtained.

In particular, when the plurality of covered wires 20 are arranged in the width direction x of the flat wire conductor 10, the space saving property in the height direction y due to the flat shape of the wire conductor 10 can be effectively utilized to construct a wire harness for wiring. For example, when wiring a wire harness in a space with a limited height, when disposing another member in the up-down direction of the wire harness, or the like, space saving can be effectively utilized. In addition, heat dissipation of each covered electric wire 20 is easily ensured.

On the other hand, in the case where the plurality of covered wires 20 are arranged in the height direction y of the flat wire conductor 10, that is, in the case where the covered wires are stacked in the height direction y, even if the dimension (width W) in the width direction x is widened due to the flat shape of the wire conductor 10, the dimension in the width direction x in the whole wire harness can be suppressed to be small and the wire harness can be configured and used for wiring. As a result, wiring can be performed with flexibility by using a space or the like that is long and thin in the height direction.

In the wire harness, the heat radiation fins are provided so as to be in contact with the arranged coated electric wires 20, so that the heat radiation properties of the coated electric wires 20 can be easily ensured even when the coated electric wires 20 are closely arranged in a large amount by using a flat shape. Here, the heat sink is a sheet-like (including plate-like) member made of a heat dissipating material having higher heat dissipation than the covered wire 20, and a sheet body or plate material made of aluminum or an aluminum alloy can be exemplified. As the arrangement of the heat sink, a mode of being sandwiched between the plurality of covered wires 20 constituting the wire harness and a mode of being provided in common contact with the plurality of covered wires 20 can be exemplified.

As shown in fig. 5 a, when a plurality of covered wires 20 are arranged in the width direction x, it is preferable that the common heat sink 31 is arranged in contact with the surface (flat surface) of each covered wire 20 in the width direction x. By bringing the flat surface having a large area due to the flat shape of the wire conductor 10 into contact with the surface of one side of the heat sink 31, the heat radiation performance of the covered wire 20 can be effectively improved. Further, by disposing the common heat sink 31 with respect to the plurality of covered wires 20, the structure of the wire harness including the heat sink 31 can be simplified. In the illustrated embodiment, the coated wires 20 do not contact each other in the width direction x, but in the case of contact, it is preferable to sandwich a heat sink between adjacent coated wires 20.

As shown in fig. 5 (b), when a plurality of covered wires 20 are arranged in the height direction y, it is preferable that a heat sink is interposed between the covered wires 20 and provided as a clip 32. The clip 32 contacts the flat surface of each covered wire 20 along the width direction x. By providing the wire conductor 10 with a flat shape, the area of the flat surface is increased, and in an array in which a plurality of covered wires 20 are arranged so that the flat surfaces having a large area are close to or in contact with each other, it may be difficult to discharge heat generated at the time of energization to the outside, but by providing the clip piece 32 between the covered wires 20, heat dissipation can be promoted.

Further, the plurality of clamping pieces 32 provided between the coated electric wires 20 are preferably connected to each other by a connecting piece 33 made of a heat radiation material. By providing the coupling member 33, the heat dissipation of each covered electric wire 20 can be improved as compared with the case where only the clip piece 32 is provided. The connecting material 33 may be a member that is provided exclusively for the purpose of heat dissipation of the covered electric wire 20 via the clip 32, or a member that is provided for another purpose may be used as the connecting material 33. For example, by using a columnar member constituting the vehicle body of the automobile as the coupling member 33, the member can be used as both a structural material of the vehicle body, a coupling member 33 for assisting heat dissipation of the covered electric wire 20 via the clip piece 32, and a support material for mounting a wire harness constituted by a plurality of covered electric wires 20.

As shown in the following embodiment, in the case where the heat sink 31 made of aluminum or aluminum alloy is provided in contact with the flat surface of the covered wire 20 in the width direction x as in the case of fig. 5 (a), the cross-sectional area of the heat sink 31 in the cross section perpendicular to the axial direction of the covered wire 20 is preferably 1.5 times or more, more preferably 4 times or more, the conductor cross-sectional area of the wire conductor 10 constituting the covered wire 20, for each covered wire. In this way, the heat dissipation of the covered electric wire 20 can be effectively improved.

(2) Wiring to a motor vehicle

As described above, by using the wire harness including the covered electric wire 20 having the flat electric wire conductor 10 as, for example, a wiring material for an automobile, excellent space saving can be effectively utilized. By routing such a wire harness along, for example, the floor, frame, etc. of a vehicle, a limited space under the floor, around the frame, etc. can be effectively used for routing. At this time, the wire harness is arranged such that the width direction x of the wire conductor 10 is substantially parallel to the floor surface and the surface of the frame material, thereby achieving particularly excellent space saving.

Since a conventional wire harness is configured by bundling covered wires having a substantially circular cross section, the wire harness as a whole has a large volume, and thus if a wiring space is to be secured in an automobile, a living space (space where passengers can stay) may be narrowed. However, as described above, by using the wire harness including the covered electric wire 20 having the flat electric wire conductor 10, the space required for wiring the wire harness is suppressed to be small, and a wider living space can be ensured.

The wire harness according to the present embodiment can be used as a wiring material for any application in an automobile, but as an appropriate application, an application as a power supply main line disposed under a floor can be exemplified. Conventionally, a general automotive power supply main line is constituted by bonding insulating sheets to a structure in which copper plates are arranged, but it is difficult to continuously mold a large copper plate, and productivity is poor. Further, since the material is composed of a continuous body of metal, there is a possibility that fatigue damage of the material is caused by an influence of engine vibration or the like of an automobile. In contrast, if the wire harness according to the present embodiment is used to form the power supply main line, the formation of the wire 1, the twisting of the wire 1, and the formation of the raw material twisted wire 10' into a flat shape, which are obtained by twisting the wire 1, are all processes that can be continuously performed on each portion of the long material, and high productivity can be achieved. In addition, since the wire conductor 10 is composed of the collection of the finer wires 1, the wire conductor 10 has high resistance to bending and vibration as a whole. Therefore, fatigue failure due to engine vibration or the like is less likely to occur.

In addition to the wiring harness according to the present embodiment, the wiring harness according to the present embodiment may be wired along the underfloor of an automobile, for example, by forming the floor or ceiling itself from the wiring harness according to the present embodiment. In an automobile, it is necessary to route a wire harness so as not to interfere with components such as an engine, but such a route is limited. In particular, in automobiles requiring a large current such as hybrid vehicles and electric vehicles, it is necessary to route electric wires having a large cross-sectional area of conductors, and a path for routing a wire harness including such large cross-sectional area electric wire conductors is limited. However, by configuring the floor and ceiling with the wire harness according to the present embodiment, it is possible to ensure a wiring path by flexibly using a space without wasting, and to ensure a wide living space, and to satisfy both space saving and a demand associated with an increase in current. In the covered electric wire for large current, the insulator is easily deteriorated by heat generated by the electric wire conductor, but the heat radiation property is easily ensured by disposing the wire harness in the floor or ceiling. As a result, even if the coated electric wire 20 is configured using the inexpensive insulator 21 that is not so high in heat resistance, deterioration of the insulator 21 is not likely to be a problem. The covered wire 20 provided with the flat wire conductor 10 has a flat surface, and the covered wire 20 is arranged in various ways at the time of forming the wire harness, so that a floor or ceiling having an arbitrary surface shape can be formed by combining the flat surfaces. In the case where the floor or ceiling is formed using the wire harness according to the present embodiment, the wire harness can be prevented from being directly exposed to the ceiling surface or floor surface by appropriately providing the coating material on the outer side of the wire harness.

As shown in fig. 6, when the wire harness according to the present embodiment is arranged on the ceiling or floor of an automobile, it is preferable that the height H be uniform even if the conductor cross-sectional areas of the plurality of covered wires 20 constituting the wire harness are different. Thus, the upper and lower surfaces of the wire harness in the height direction can be formed as a plane, and a high space saving in the height direction can be obtained when wiring is performed along the surfaces of the ceiling and the floor. In addition, the uneven structure in the height direction of the wire harness is less likely to affect the design in the interior of the automobile and the functions of adjacent members. The height H of the covered electric wire 20 is uniform, and the difference in height H between the individual covered electric wires 20 is controlled to be within 10% of the average height.

As described above, as shown in fig. 6, it is preferable that the wire harness having the height H of the covered wire 20 uniform is arranged such that a flat surface along the width direction x is along the surfaces of the interior material 51 and the sound absorbing material 52 between the interior material 51 constituting the floor or ceiling of the automobile and the sound absorbing material 52 provided adjacently to the outside (the side opposite to the living space) of the interior material 51. In this way, the small space between the interior material 51 and the sound absorbing material 52 can be effectively and flexibly applied to the wiring of the wire harness. By making the height H of the covered electric wire 20 uniform, the wire harness can be arranged without unnecessarily widening the distance between the interior member 51 and the sound absorbing member 52. In addition, the uneven structure in the height direction of the wire harness is expressed as an uneven structure of the surface of the interior component 51, and it is possible to prevent the surface of the interior component 51 from being lowered in design. Further, the covered electric wire 20 having a large uneven height H can be prevented from pressing the surface of the sound absorbing material 52, which may affect the performance of the sound absorbing material 52, such as the uneven sound absorbing property. As a combination of the interior member 51 and the sound absorbing member 52, which can dispose the wire harness in the middle, a combination of the floor covering and the exhaust muffler can be exemplified.

The wire harness according to the present embodiment can be wired to an automobile using various members constituting the body of the automobile as a support material. For example, as shown in fig. 7 (a), a wire harness may be arranged along the outer periphery of the columnar member 41 constituting the vehicle body. At this time, the wire harness may be arranged such that the surface of each covered wire 20 constituting the wire harness along the width direction x is along the outer peripheral surface of the columnar member 41. Alternatively, as shown in fig. 7 (b), the wire harness may be disposed in the hollow portion 42b of the hollow tubular member 42 having the opening 42a in the longitudinal direction, which is a long member intersecting the longitudinal direction and having a cross section of substantially U-shape, substantially -shape, or the like. At this time, the plurality of covered wires 20 are arranged in a plurality of rows in the width direction x and/or the height direction y so that the harness matches the shape of the opening 42a and the hollow portion 42 b. As described above, the heat sink may be appropriately disposed between the arranged covered wires 20. As the columnar member 41 and the tubular member 42, for example, a member serving as a stiffener disposed in front of an instrument panel of an automobile can be exemplified.

(3) Combined with other wires

As described above, the wire harness according to the embodiment of the present invention can be configured by using the covered wire 20 having the flat wire conductor 10 according to the embodiment of the present invention and other types of covered wires in combination. The specific constituent materials, shapes, sizes, and the like of the covered electric wire 20 and other kinds of covered electric wires according to the embodiment of the present invention may be arbitrarily combined. Among these, the following modes can be exemplified: as the coated wire 20 (first coated wire) according to the embodiment of the present invention, a coated wire having a flat wire conductor 10 made of aluminum or aluminum alloy (aluminum-based material) is used, and as another type of coated wire (second coated wire), a coated wire having a wire conductor made of copper or copper alloy (copper-based material) and having a lower flatness than the wire conductor 10 of the first coated wire 20, such as a substantially circular cross section, is used. In this case, it is preferable that the conductor cross-sectional area of the second covered electric wire is smaller than the conductor cross-sectional area of the first covered electric wire 20.

In order to reduce the weight of the entire automobile, aluminum-based materials are used as the material of the wire conductor for the automobile instead of copper-based materials, but as described above, the conductivity as the material is lower in the case of using aluminum-based materials than in the case of using copper-based materials, and thus the conductor cross-sectional area of the wire conductor tends to increase. If the wire conductor made of such an aluminum-based material is used for a wire harness while being a conventional conductor having a circular cross section, the space required for wiring of the wire harness is increased by increasing the diameter of the wire conductor, but by forming the wire conductor 10 in a flat shape, a large conductor cross section area can be ensured and the space required for wiring can be reduced. On the other hand, even in the case of a wire conductor using a copper-based material, if the conductor is a small-diameter wire having a small cross-sectional area, the wire conductor does not greatly hinder the weight reduction of the automobile. In addition, an increase in space required for wiring of the wire harness is not easily caused. Therefore, by combining the first covered wire 20 having the flat wire conductor 10 made of the aluminum-based material with the second covered wire having the wire conductor made of the copper-based material having a substantially circular cross section smaller than the cross section of the conductor, it is possible to use the excellent characteristics of the copper-based material such as high conductivity as the characteristics of one portion of the wire harness while securing space saving. As the wire conductor constituting the second covered wire, a conductor having a cross-sectional area of 0.13mm can be exemplified ² Or copper alloy thin wires smaller than the same. Such a copper alloy thin wire can be suitably used as a signal line. By forming the second covered wire in such a way thatThe following effects can be effectively utilized for the thin covered electric wire: the effect of saving space is achieved by using a covered wire having a flat wire conductor 10 as the first covered wire 20.

Examples

The following illustrates embodiments of the invention. The present invention is not limited to these examples.

[ State of section of wire conductor ]

The state of the void and the deformed state of the wire were confirmed for the cross section of the wire conductor formed into a cross-section flat shape.

(test method)

Twisting 741 aluminum alloy wires with the outer diameter of 0.32mm to obtain a conductor with the sectional area of 60mm ² A raw material strand of substantially circular cross section.

The raw material strand was rolled using a roll to prepare a wire conductor having a substantially rectangular cross section. As shown in fig. 3, the roll-based rolling is performed by: after the forces F1, F2 are initially applied from the up-down direction, the forces F1', F2' are applied again from the same direction as this, and the forces F3, F4 are applied from both sides in the width direction. At this time, by varying the magnitude of the applied force, sample 1 having a small compression ratio (reduction ratio of the cross-sectional area) and sample 2 having a large rolling reduction ratio were produced. Thereafter, an insulator of 1.5mm in thickness, which was made of PVC, was coated on the outer periphery of each wire conductor.

Each of the samples 1 and 2 was embedded in an epoxy resin, and a cross section intersecting the axial direction was polished to prepare a cross section sample. Then, photographs were taken of the obtained cross-sectional samples.

Image analysis was performed on photographs of the photographed sections, and the void fraction was evaluated. At this time, the cross-sectional area (A0) of the whole wire conductor is estimated as the area of the region inside the contour line connecting the contours of the wires located at the outermost periphery of the wire conductor, and the area (A1) of the void is estimated as the area of the region not occupied by the wires in the region, and the void ratio (A1/a0×100%) is calculated.

Further, the deformation ratio of the wire rod was evaluated based on image analysis. At this time, the deformation ratio of the wire rod was estimated as described in the above formula (1). As the circle diameter R, 0.32mm as the outer diameter of the raw material strand before compression was used. The deformation ratio of the wire rod was estimated for the wire rod included in the outer peripheral portion (end portion) of the square region R1 shown in fig. 8 (b) and (c) and the center portion of the square region R2 shown in the same, and the average value of the deformation ratio in each region was calculated. Further, as a ratio of the deformation ratio of the outer peripheral portion to the deformation ratio of the central portion, an outer Zhou Bianxing ratio (outer peripheral portion deformation ratio/central portion deformation ratio×100%) was calculated.

(test results)

Fig. 8 shows a photograph taken of a cross section of a covered wire. (a) corresponds to a raw strand before compression, (b) corresponds to sample 1 of low compression ratio, and (c) corresponds to sample 2 of high compression ratio. The values of the void fraction and the deformation rate obtained by the image analysis are summarized in table 1 below for sample 1 and sample 2.

TABLE 1

When comparing the sectional photographs of sample 1 and sample 2 in fig. 8 (b) and (c), a relatively large gap remains between the wires in sample 1, whereas the wires in sample 2 are tightly filled. In sample 1, the cross section of each wire rod was not greatly deformed with respect to the substantially circular shape before rolling in fig. 8 (a), whereas in sample 2, a large number of wire rods were observed to be greatly deformed with respect to the circular shape. In particular, if attention is paid to the widthwise end portion of the wire conductor, in the sample 1, the end portion is smoothly shaped, whereas in the sample 2, as shown by a circle, a sharp burr is generated.

These trends observed in the photographs are more clearly shown in the image analysis results of table 1. First, regarding the void ratio of the wire conductor section, 30% in sample 1 and 16% in sample 2, and sample 1 was about 2 times that of sample 2. In addition, in sample 1, as shown by the arrow in fig. 8 (b), there are a large number of continuous voids capable of accommodating two or more wires, whereas in sample 2 of fig. 8 (c), such large continuous voids are hardly observed.

Next, regarding the deformation ratio of the wire rod, the deformation ratio of the central portion of the wire conductor was the same in sample 1 and sample 2. However, the deformation ratio of the outer peripheral portion greatly differs between sample 1 and the sample. In sample 1, the deformation ratio of the outer peripheral portion was smaller than that of the central portion, and was suppressed to 18% of the value of the central portion. In contrast, in sample 2, the deformation ratio of the outer peripheral portion was the same as that of the central portion.

From the above results, it was confirmed that: by suppressing the compression ratio at the time of rolling the raw material strand to be small, it is possible to obtain a wire conductor having a flat cross-sectional shape in a state where the wire rod has a large void ratio and the deformation ratio of the wire rod at the outer peripheral portion is smaller than that at the central portion.

[ flexibility of coated wire ]

The influence of the cross-sectional shape of the wire conductor on the flexibility of the covered wire was confirmed.

(test method)

Wire conductors having circular cross sections and flat cross sections made of aluminum alloy were produced in the same manner as in the test of "the state of cross section of wire conductor" described above. Further, an insulating coating was provided in the same manner as described above to prepare a coated wire. The conductor cross-sectional area of the wire conductor was set to 35mm ² And 130mm ² These two groups. And the aspect ratio of the cross-sectional flat shape is 35mm in the cross-sectional area of the conductor ² In the case of (2), set to 1:3, 130mm in conductor cross-section ² In the case of (2), set to 1:4.

the flexibility of each of the coated wires was evaluated based on measurement of repulsive force. The repulsive force was measured by a 3-point bending method. That is, both ends of the covered wire having a length of 100mm were held, and the repulsive force when bending was applied to the central portion was measured by the load cell.

(test results)

Table 2 below shows the measurement results of the repulsive force obtained for each coated wire.

TABLE 2

According to table 2, in an arbitrary conductor cross-sectional area, the repulsive force is reduced by changing the cross-sectional shape from a circular shape to a flat shape. I.e. the flexibility becomes high. At e.g. 130mm ² Even when the conductor cross-sectional area is large in this way, flexibility can be improved by flattening. In any cross-sectional area of the conductor, the repulsive force is reduced to 90% or less by flattening, but in the case where the cross-sectional area of the conductor is large, in order to achieve the same degree of improvement in flexibility, it is necessary to increase the aspect ratio (increase in width) of the flat shape.

[ Heat dissipation Property of coated wire ]

The relationship between the heat dissipation of the covered wire and the shape of the wire conductor and the presence or absence of the heat sink was confirmed by computer simulation.

(test method)

The degree of temperature rise when the covered wire is energized was estimated by computer simulation using a thermal conduction analysis based on a finite element method. Specifically, as a sample, a sample having a circular cross section and an aspect ratio of 1:3 has a flat shape and an aspect ratio of 1:5, the outer circumference of the three groups of copper wire conductors having a flat shape is formed with an insulating coating made of PVC having a thickness of 1.6 mm. The conductor cross-sectional area was 134.5mm for the case of circular cross-section ² In the case where the cross section is flat, three groups are changed based on the values. Then, for each sample, the temperature rise at the time of reaching a steady state by the current flowing through 400A was estimated by simulation. The temperature of the surrounding environment was set to 40 ℃.

In addition, for a fiber having an aspect ratio of 1:5, and also in the case of providing a heat sink on the covered wire of the flat wire conductor, the temperature rise is estimated in the same manner. As the heat sink, aluminum plates of two groups of 5mm in thickness, 30mm in width and 60mm in width were used. The center of the coated wire in the width direction x is aligned with the center of the heat sink in the width direction, and the flat surface of the coated wire along the width direction x is arranged so as to be closely adhered to the surface of one side of the heat sink.

(test results)

The temperature rise values obtained by simulation for each sample are shown in fig. 9 as a function of conductor cross-sectional area. In fig. 9, the approximation curves are also shown.

According to fig. 9, the temperature rise is suppressed to be lower in the case of the cross-sectional flat shape than in the case of the wire conductor having a circular cross-section. Namely, the heat dissipation property is improved. In particular, the larger the aspect ratio of the flat shape (the larger the width), the more the heat radiation property is improved. As a result, when the upper limit of the temperature rise is set to a predetermined temperature value, the electric wire conductor is formed into a cross-sectional flat shape, and the aspect ratio is further increased, so that the temperature rise can be suppressed within the upper limit even if the conductor cross-sectional area of the electric wire conductor is reduced. For example, when the upper limit of the temperature rise is 40 ℃, the lower limit of the conductor cross-sectional area is about 135mm when the cross-section is circular ² At an aspect ratio of 1:3 is about 125mm in the case of a flat shape ² At an aspect ratio of 1:5 is about 120mm in the case of a flat shape ² 。

Further, when the heat sink is provided to the covered wire having the wire conductor with a flat cross-section, the heat radiation performance is further improved. In particular, the larger the cross-sectional area of the fin, the more the heat dissipation property is improved. That is, when the upper limit of the temperature rise is set to a predetermined temperature value, the use of the heat sink having a large cross-sectional area can suppress the temperature rise within the upper limit even if the conductor cross-sectional area of the wire conductor is reduced. For example, when the upper limit of the temperature rise is 40 ℃, the lower limit of the conductor cross-sectional area is about 95mm when the width of the fin is 30mm ² . At this time, the cross-sectional area of the heat sink is about 1.6 times the cross-sectional area of the conductor. On the other hand, in the case where the width of the fin is 60mm, the lower limit value of the conductor cross-sectional area is 67mm ² . At this time, the cross-sectional area of the heat sink is about 4.5 times the cross-sectional area of the conductor.

The embodiments of the present invention have been described in detail above, but the present invention is not limited to the above embodiments in any way, and various modifications can be made without departing from the spirit of the present invention.

In the above description, the wire conductor has been described as having a porosity equal to or greater than a predetermined porosity, but a structure in which the wire conductor does not have a porosity may be considered, in which the wire conductor is formed of a twisted wire formed by twisting a plurality of wires and has a flat portion having a flat cross section intersecting the axis direction of the twisted wire. Further, in the case of adopting such a configuration, flexibility can be improved and space saving can be achieved by flattening the cross-sectional shape, as compared with the case where the cross-sectional shape is substantially circular. In this case, structures other than the above-described void ratio, such as a deformation ratio, which are structures related to the wire conductor, a cross-sectional shape of each wire, a material and a conductor cross-sectional area of the wire conductor, an aspect ratio of the wire conductor, and coexistence of the flat portion and the low flat portion, can be suitably applied. In addition, the structure related to the covered electric wire and the wire harness described above can also be applied appropriately.

Description of the reference numerals

1. Wire rod

10. Wire conductor

10' raw material strand

20. Coated electric wire

21. Insulation body

H height

W width

In the x width direction

y-height direction

31. Heat sink

32. Clamping sheet (Cooling fin)

33. Connecting piece

41. Columnar member

42. Tubular member

51. Interior component

52. And a sound absorbing member.

Claims

1. An electric wire conductor, characterized in that,

the wire conductor is constituted by a stranded wire formed by stranding a plurality of wires,

has a flat part having a cross section intersecting the axial direction of the twisted wire and formed of a flat shape,

the flat section has a continuous space capable of accommodating two or more wires in a cross section thereof,

the continuous gap capable of accommodating two or more wires is present in a region of the wire conductor excluding the outermost peripheral portion.

2. A wire conductor according to claim 1, wherein,

the deformation rate of the wire rod with respect to a circular shape in the cross section of the flat portion is 50% or less at a portion of the flat portion facing the outer periphery of the flat portion.

3. A wire conductor according to claim 1, wherein,

The wire rod in the cross section of the flat portion has a deformation ratio with respect to a circular shape of 10% or less at a portion facing the outer periphery of the flat portion.

4. A wire conductor according to claim 1, wherein,

the cross section of the flat portion has opposite sides parallel to each other in the width direction of the flat shape,

the deformation ratio of the wire rod with respect to a circular shape in the cross section of the flat portion is smaller at the end portions of the opposite sides of the flat portion that are parallel to each other than at the central portion of the flat portion.

5. A wire conductor according to claim 1, wherein,

the flat portion and the low flat portion having a lower flatness than the flat portion are continuously provided in the axial direction.

6. A wire conductor according to claim 1, wherein,

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

7. A covered electric wire, comprising:

the wire conductor of any one of claims 1 to 6; and

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

8. A wire harness is characterized in that,

comprising the coated wire of claim 7.

9. The wire harness as claimed in claim 8, wherein,

A plurality of covered wires according to claim 7, which are arranged along at least one of a width direction of the wire conductor and a height direction intersecting the width direction,

the wire harness has at least one of a heat sink interposed between the plurality of covered wires and a heat sink commonly contacting the plurality of covered wires.

10. The wire harness according to claim 8 or 9, wherein,

comprising a plurality of covered wires according to claim 7, which are arranged at least in the width direction of the wire conductor,

the plurality of covered wires arranged in the width direction include covered wires having different conductor cross-sectional areas, and have a uniform dimension in a height direction intersecting the width direction.

11. The wire harness according to claim 8 or 9, wherein,

a covered electric wire comprising a plurality of the covered electric wires according to claim 7, the plurality of covered electric wires being arranged at least in a height direction intersecting with a width direction of the electric wire conductor.

12. The wire harness as claimed in claim 11, wherein,

a clip made of a heat radiation material is interposed between the plurality of covered wires arranged in a height direction intersecting the width direction, and a connecting member for connecting the plurality of clip to each other and made of a heat radiation material is provided.

13. The wire harness according to claim 8 or 9, wherein,

the wire harness includes a first covered electric wire and a second covered electric wire,

the first coated electric wire is the coated electric wire according to claim 7, wherein the electric wire conductor is made of aluminum or an aluminum alloy,

the wire conductor of the second covered wire is made of copper or copper alloy, has lower flatness and a smaller conductor cross-sectional area than the wire conductor of the first covered wire.

14. The wire harness as claimed in claim 13, wherein,

the conductor cross-sectional area of the second covered wire is 0.13mm ² The following is given.