Electric wire

Abstract

To provide an electric wire capable of preventing cracking in an orange-colored body located inside a transparent resin.SOLUTION: An electric wire 1 comprises an orange-colored body 12 provided on a conductor 11 and a transparent resin 13 coated over the orange-colored body 12. The conductor 11 has an outer diameter L1 of 10 mm to 30 mm. The orange-colored body 12 has a thickness of 1 mm or less and an elongation of at least 44.5%, thereby preventing cracking during R20 bending in the radial direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an electric wire.

Background Art

[0002] In recent years, with the electrification of vehicles, the voltage and current of electric wires have been increasing for the purpose of shortening charging time and the like. For such high-voltage and high-current electric wires, it is necessary to display them in orange to ensure safety inside the vehicle. Therefore, conventionally, when an insulator is extrusion-coated on a conductor, an orange pigment is melt-mixed with a raw material such as PVC (Polyvinyl Chloride) or PE (Polyethylene) to color the insulator of the electric wires orange.

[0003] However, when an orange pigment is mixed with the insulator of the electric wire, there is a problem that the properties such as heat resistance of the insulator are deteriorated by the orange pigment. Further, when a UV-curable resin that cures according to the transmission wavelength of UV (Ultraviolet) is used for the insulator, there is a problem that UV hardly passes through due to coloring and curing does not occur.

[0004] Therefore, it is conceivable to wrap an orange tape around an electric wire whose insulator is not orange, or insert the electric wire into an orange string. However, in either case, there is a problem that the orange display is lost when the tape or string wears due to vibrations of the vehicle or the like.

[0005] Therefore, an electric wire including a conductor, a color coating film on the conductor, and a transparent insulating coating layer on the color coating film has been proposed (see, for example, Patent Document 1). By making the color coating film orange in this electric wire, the orange color can be displayed through the transparent insulating coating layer, and even if the electric wire is in a worn environment, the transparent insulating coating layer will wear and it is possible to make it difficult to lose the display.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] Here, the inventors of the present case are researching wires with high voltage and large current. As a result of their intensive research, it has been found that if the orange layer located inside the transparent resin (transparent insulating coating layer) is not properly configured, cracking of the orange layer will occur when the wire is bent. In particular, for wires with high voltage and large current, the conductor tends to be thick, and when bent, a large strain is likely to be applied to the orange layer, making it prone to cracking. And when the orange layer cracks, there is a possibility of overlooking the orange color, and the orange display may become inappropriate.

[0008] The present invention has been made to solve such conventional problems, and an object thereof is to provide a wire capable of preventing cracking of an orange-colored body located inside a transparent resin.

Means for Solving the Problems

[0009] The wire according to the present invention is a wire including an orange-colored body provided on a conductor and a transparent resin coated on the orange-colored body, wherein the conductor has a cross-sectional length in a predetermined direction in a cross-section orthogonal to the longitudinal direction of 10 mm or more and 30 mm or less, the orange-colored body has a thickness of 1 mm or less, has an elongation rate of at least 44.5%, and is prevented from cracking when bent at R20 in the predetermined direction.

Effects of the Invention

[0010] According to the present invention, it is possible to provide a wire capable of preventing cracking of an orange-colored body located inside a transparent resin.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0012] Hereinafter, the present invention will be described along preferred embodiments. Note that the present invention is not limited to the embodiments shown below, and can be appropriately changed without departing from the gist of the present invention. Further, in the embodiments shown below, there are some places where the illustration and description of some configurations are omitted, but it goes without saying that well-known or well-known techniques are appropriately applied within the range not conflicting with the content described below for the details of the omitted techniques.

[0013] FIG. 1 is a perspective view showing a first example of an electric wire according to an embodiment of the present invention. As shown in FIG. 1, the electric wire 1 according to the first example includes a conductor 11, an orange-colored body 12, and a transparent resin 13.

[0014] The conductor 11 is made of, for example, copper, aluminum, or an alloy thereof, and in this embodiment, it is a round conductor having a circular cross section. In this embodiment, it is assumed that the conductor 11 is a single wire capable of handling high voltage and large current, but it is not particularly limited thereto, and it may be composed of two or more members (for example, a plurality of stranded wires).

[0015] The orange-colored body 12 is provided on the conductor 11 and is a member whose at least the outer peripheral side is orange. This orange-colored body 12 is composed of, for example, a resin tape (such as a vinyl tape), a cloth tape, and a stranded cord. The resin tape and the cloth tape have an adhesive layer on one side, and are wound longitudinally or spirally on the conductor 11 with the adhesive layer facing the conductor 11 side. The stranded cord is formed by braiding a bundle of fine wires into a cylindrical shape, and is provided on the conductor 11 by inserting the conductor 11 into the cylinder. Note that all these types of orange-colored bodies 12 are capable of withstanding the temperature rise when a large current flows through the electric wire 1 and the temperature of the transparent resin 13 when the transparent resin 13 is extrusion-coated on the orange-colored body 12 as described later.

[0016] Here, in this embodiment, the orange color is assumed to be in the range of Munsell colors 10R6 / 16, 10R7 / 14, and 10R7 / 16. However, the orange color is not particularly limited to this, and may be, for example, a color in the range of Munsell colors 10R8 / 22, 10R8 / 24, 10R8 / 26, 10R7 / 18, 10R7 / 20, 10R7 / 22, 10R6 / 18, and 10R6 / 20.

[0017] The transparent resin 13 is an insulating resin coated on the orange-colored body 12. Specifically, examples of the transparent resin 13 as a thermoplastic resin include PC (Polycarbonate), PMMA (Polymethyl methacrylate), an acrylic resin, and polystyrene. Examples of the transparent resin 13 as a UV curable resin include urethane acrylate, epoxy acrylate, acrylic acrylate, and polyester acrylate. Note that the thickness of the transparent resin 13 is preferably 2 mm or less.

[0018] Figure 2 is a perspective view showing a second example of the electric wire according to the embodiment of the present invention. As shown in Figure 2, the electric wire 2 according to the second example also includes a conductor 21, an orange-colored body 22, and a transparent resin 23.

[0019] In the second example, the conductor 21 is a bus bar conductor with a rectangular cross-section. Other configurations are the same as those of the conductor 11 in the first example. The conductor 21 may be composed of two or more members such as two or more plates. Also, due to the fact that the conductor 21 is a bus bar conductor in the second example, the orange-colored body 22 is provided on the conductor 21 so as to have a square cross-section. Furthermore, since the orange-colored body 22 has a square cross-section, the transparent resin 23 is also coated on the orange-colored body 22 so as to have a square cross-section.

[0020] In such electric wires 1 and 2 according to this embodiment, since the transparent resins 13 and 23 are coated on the orange-colored bodies 12 and 22, the orange color can be recognized from the outside. Thereby, it is possible to make workers and the like recognize that the electric wires 1 and 2 are for high voltage and large current. Moreover, since the transparent resins 13 and 23 are provided on the orange-colored bodies 12 and 22, even if the electric wires 1 and 2 are in a wear environment, the transparent resins 13 and 23 will wear, making it difficult to lose the orange display.

[0021] Furthermore, in this embodiment, the conductors 11 and 21 have a cross-sectional length in a predetermined direction in a cross-section orthogonal to the longitudinal direction of the electric wires 1 and 2 of 10 mm or more and 30 mm or less. Specifically, since the electric wire 1 shown in FIG. 1 is a round electric wire, the predetermined direction is the radial direction. Therefore, it can be said that the outer diameter L1 of the conductor 11 is 10 mm or more and 30 mm or less. Also, since the electric wire 2 shown in FIG. 2 is a bus bar electric wire, the predetermined direction is the thickness direction or the width direction. Therefore, it can be said that the length L2 in the thickness direction or the length L3 in the width direction of the conductor 21 is 10 mm or more and 30 mm or less.

[0022] In addition, the orange-colored bodies 12 and 22 according to this embodiment have a thickness of 1 mm or less and have an elongation rate of at least 44.5%. Thereby, when the electric wires 1 and 2 are bent at R20 in a predetermined direction, cracking of the orange-colored bodies 12 and 22 is prevented due to the relationship between the strain applied to the orange-colored bodies 12 and 22 and the elongation rate.

[0023] Here, if the orange-colored bodies 12 and 22 are cracked, it may lead to the operator or the like overlooking the orange color. However, in the electric wires 1 and 2 according to the present embodiment, cracking of the orange-colored bodies 12 and 22 is prevented even when bent by R20 in a predetermined direction. For this reason, the possibility of overlooking the orange-colored bodies 12 and 22 due to cracking is suppressed.

[0024] Also, in the present embodiment, the orange-colored bodies 12 and 22 preferably have an elongation rate of 62% or more. Theoretically, when the elongation rate is 62% or more, cracking of the orange-colored bodies 12 and 22 can be prevented even when bent by R10 in a predetermined direction. That is, cracking can be prevented even when bending measures are taken in a narrower location.

[0025] Next, examples and comparative examples of the present invention will be described. FIGS. 3 and 4 are charts showing examples and comparative examples of the present invention. Note that FIGS. 3 and 4 show the results of a bending test performed without coating a transparent resin on the orange-colored body in order to confirm cracking of the orange-colored body.

[0026] First, in Examples 1 to 25 and Comparative Examples 1 and 2 shown in FIG. 3, the orange-colored body is a vinyl tape provided longitudinally on the conductor. The thickness of the vinyl tape is 0.09 mm in Examples 1 to 16 and Comparative Examples 1 and 2, and 0.07 mm in Examples 17 to 25. The elongation rate of the orange-colored body is 180% in Examples 1 to 9, 50% in Examples 10 to 16 and Comparative Examples 1 and 2, and 160% in Examples 17 to 25. Also, in a cross section orthogonal to the longitudinal direction of the conductor on which the orange-colored body is provided, the cross-sectional length in a predetermined direction is 10 mm in Examples 1 to 3, 10 to 12, and 17 to 19, 20 mm in Examples 4 to 6, 13, 14, 20 to 22, and Comparative Example 1. Further, the cross-sectional length in a predetermined direction is 30 mm in Examples 7 to 9, 15, 16, 23 to 25, and Comparative Example 2.

[0027] The conductor and the orange-colored body as described above have a cross-sectional length in the overall predetermined direction of 10.18 mm in Examples 1 to 3, 10 to 12, 20.18 mm in Examples 4 to 6, 13, 14 and Comparative Example 1, and 30.18 mm in Examples 7 to 9, 15, 16 and Comparative Example 2. Also, the cross-sectional length in the overall predetermined direction is 10.14 mm in Examples 17 to 19, 20.14 mm in Examples 20 to 22, and 30.14 mm in Examples 23 to 25.

[0028] Also, in Examples 26 to 41 and Comparative Examples 3 to 6 shown in FIG. 4, the orange-colored body is a resin string (twisted string) of PET (Polyethylene Terephthalate), and the resin string is provided outside the conductor by inserting the conductor inside. The thickness of the resin string is 0.50 mm in Examples 26 to 33 and Comparative Examples 3 and 4, and 1.00 mm in Examples 34 to 41 and Comparative Examples 5 and 6. The elongation rate of the orange-colored body is 48% in Examples 26 to 33 and Comparative Examples 3 and 4, and 44.5% in Examples 34 to 41 and Comparative Examples 5 and 6. Also, in the cross-section orthogonal to the longitudinal direction of the conductor to which the orange-colored body is provided, the cross-sectional length in the predetermined direction is 10 mm in Examples 27 to 29, 35 to 37, 20 mm in Examples 30, 31, 38, 39 and Comparative Example 3, 5, and 30 mm in Examples 26, 32 to 34, 40, 41 and Comparative Examples 4, 6.

[0029] The conductor and the orange-colored body as described above have a cross-sectional length in the overall predetermined direction of 11 mm in Examples 27 to 29, 21 mm in Examples 30, 31 and Comparative Example 3, and 31 mm in Examples 26, 32, 33 and Comparative Example 4. Also, the cross-sectional length in the overall predetermined direction is 12 mm in Examples 35 to 37, 22 mm in Examples 38, 39 and Comparative Example 5, and 32 mm in Examples 34, 40, 41 and Comparative Example 6.

[0030] Bending tests were conducted on Examples 1 to 41 and Comparative Examples 1 to 6. In the bending test, for each sample of Examples 1 to 41 and Comparative Examples 1 to 6 with a predetermined length having one end fixed and the other end being a free end, when it was bent 180 degrees in a predetermined direction along a mandrel, the presence or absence of cracks was confirmed by checking whether the conductor was exposed on the outer side of the bend. On the outer side of the 180-degree bend, those where the conductor could be confirmed were regarded as having cracks ("×" in FIGS. 3 and 4), and those where the conductor could not be confirmed were regarded as having no cracks ("〇" in FIGS. 3 and 4).

[0031] The mandrels used were those with R10 in Examples 3, 6, 9, 12, 19, 22, 25, 29, 37 and Comparative Examples 1 to 6, and those with R20 in Examples 2, 5, 8, 11, 14, 16, 18, 21, 24, 28, 31, 33, 36, 39, 41. Also, the mandrels in Examples 1, 4, 7, 10, 13, 15, 17, 20, 23, 26, 27, 30, 32, 34, 35, 38, 40 were those with R30.

[0032] For Examples 1 to 12, the calculated strain amounts were 14.51%, 20.29%, 33.73%, 25.17%, 33.53%, 50.22%, 33.47%, 43.00%, 60.14%, 14.51%, 20.29%, and 33.73% in order. Also, for Examples 13 to 23, the calculated strain amounts were 25.17%, 33.53%, 33.47%, 43.00%, 14.46%, 20.22%, 33.64%, 25.13%, 33.49%, 50.17%, and 33.44% in order.

[0033] For Examples 24 to 35, the calculated strain amounts were 42.97%, 60.11%, 34.07%, 15.49%, 21.57%, 35.48%, 25.93%, 34.43%, 34.07%, 43.66%, 34.78%, and 16.67% in sequence. For Examples 36 to 41, the calculated strain amounts were 23.08%, 37.50%, 26.83%, 35.48%, 34.78%, and 44.44% in sequence. For Comparative Examples 1 to 6, the calculated strain amounts were 50.22%, 60.14%, 51.22%, 60.78%, 52.38%, and 61.54% in sequence.

[0034] For Examples 1 to 41 as described above, the elongation rate exceeded the calculated strain amount, and no cracks were confirmed in the results of the bending test. On the other hand, for Comparative Examples 1 to 6, the elongation rate did not exceed the calculated strain amount, and cracks were confirmed in the results of the bending test.

[0035] From the above experimental results, when the cross-sectional length in a predetermined direction of the conductor is 10 mm or more and 30 mm or less, and the thickness of the orange-colored body is 1 mm or less, it was found that no cracks occur when bending in the predetermined direction of R20 if the elongation rate of the orange-colored body is 44.5% or more. Furthermore, from the experimental results, it was found that no cracks occur when bending in the predetermined direction of R10 both when the elongation rate of the orange-colored body is 160% and 180%. In particular, from a calculation perspective, it can be said that no cracks occur when bending in the predetermined direction of R10 if the elongation rate of the orange-colored body is 62% or more in the range where the cross-sectional length in a predetermined direction of the conductor is 10 mm or more and 30 mm or less.

[0036] In this way, according to the electric wires 1 and 2 according to this embodiment, the conductors 11 and 21 have a cross-sectional length in a predetermined direction in the cross-section of 10 mm or more and 30 mm or less, and the orange-colored bodies 12 and 22 have a thickness of 1 mm or less and have an elongation rate of at least 44.5%. For this reason, when the electric wires 1 and 2 are bent at R20 in a predetermined direction, cracking of the orange-colored bodies 12 and 22 is prevented. Therefore, it is possible to provide the electric wires 1 and 2 capable of preventing cracking of the orange-colored bodies 12 and 22 located inside the transparent resins 13 and 23.

[0037] In addition, when the orange-colored bodies 12 and 22 have an elongation rate of 62% or more, cracking is prevented even when R10 is bent in a predetermined direction. Therefore, even when more local bending occurs, it is possible to provide the electric wires 1 and 2 that can prevent cracking in the orange-colored bodies 12 and 22.

[0038] As described above, the present invention has been described based on the embodiments. However, the present invention is not limited to the above embodiments, and modifications may be made without departing from the spirit of the present invention, and known or well-known technologies may be combined if possible.

[0039] For example, in the present embodiment, the conductors 11 and 21 are not limited to one member and may be composed of two or more members. Further, for the orange-colored bodies 12 and 22, it is sufficient that they are colored with the Munsell color required for electric wires for high voltage and large current, and it is not limited to the above-exemplified Munsell color.

Explanation of Reference Numerals

[0040] 1, 2: Electric wire 11, 21: Conductor 12, 22: Orange-colored body 13, 23: Transparent resin L1: Outer diameter (cross-sectional length in a predetermined direction) L2: Length in the thickness direction (cross-sectional length in a predetermined direction) L3: Length in the width direction (cross-sectional length in a predetermined direction)

Claims

1. An electric wire comprising an orange-colored body provided on a conductor and a transparent resin coated on the orange-colored body, wherein the conductor has a cross-sectional length in a predetermined direction in a cross-section orthogonal to the longitudinal direction of 10 mm or more and 30 mm or less, the orange-colored body has a thickness of 1 mm or less, has an elongation rate of at least 44.5%, and is prevented from cracking when bent at R20 in the predetermined direction characterizing the electric wire.

2. The orange-colored body has an elongation rate of 62% or more and is prevented from cracking when bent at R10 in the predetermined direction characterizing the electric wire according to Claim 1.

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