Electric wire and method for routing electric wire

Abstract

An electric wire (1) comprises a conductor (11), an orange dye (12) provided over the conductor (11), and a transparent resin (13) coated onto the orange dye (12), wherein the conductor (11) has an outer diameter (L1) of 10-30 mm, and the orange dye (12) has a thickness of 1 mm or less and an elongation percentage of at least 44.5%, which prevents cracking during R20 bending in the radial direction.

Description

Electric wires and wiring methods

[0001] The present invention relates to an electric wire and a method for routing the electric wire.

[0002] In recent years, with the electrification of vehicles, electric wires have become increasingly high-voltage and high-current in order to shorten charging times, etc. Such high-voltage and high-current electric wires must be marked in orange to ensure safety inside the vehicle. Therefore, conventionally, when extruding insulation onto conductors, orange pigments are melt-mixed into raw materials such as PVC (Polyvinyl Chloride) and PE (Polyethylene) to color the insulation of electric wires orange.

[0003] However, mixing an orange pigment into the insulator of an electric wire causes problems such as a decrease in the heat resistance and other properties of the insulator due to the orange pigment. Also, when a UV (ultraviolet) curing resin that cures when UV light transmits is used for the insulator, there is a problem that the coloring makes it difficult for UV light to penetrate, preventing curing.

[0004] To address this issue, it is possible to wrap orange tape around wires that do not have orange insulation, or to insert the wires into orange braided cord. However, in either case, there is a problem that if the tape or braided cord wears away due to vehicle vibrations, the orange marking will disappear.

[0005] Therefore, an electric wire has been proposed that includes a conductor, a color coating film on the conductor, and a transparent insulating coating layer on the color coating film (see, for example, Patent Document 1). By making the color coating film in this electric wire orange, the orange color can be displayed through the transparent insulating coating layer, and even if the electric wire is placed in an abrasive environment, the transparent insulating coating layer will not wear away, making it difficult for the display to be lost.

[0006] Japanese Patent Application Publication No. 2002-216548

[0007] The present inventors have been studying high-voltage and high-current electric wires. As a result of their intensive research, they have discovered that in the electric wire described in Patent Document 1, if the orange layer located inside the transparent resin (transparent insulating coating layer) is not appropriately configured, the orange layer may crack when the electric wire is bent. In particular, high-voltage and high-current electric wires tend to have thicker conductors, which makes the orange layer more susceptible to large strain and cracking when bent. If the orange layer cracks, the orange color may be overlooked, potentially resulting in an inappropriate orange display.

[0008] The present invention has been made to solve these conventional problems, and its purpose is to provide an electric wire and an electric wire routing method that can prevent cracks in the orange-colored body located inside the transparent resin.

[0009] An electric wire according to one embodiment of the present invention comprises 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 perpendicular 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 and an elongation of at least 44.5%, and cracking is prevented when the wire is bent at an R20 angle in the predetermined direction.

[0010] According to the present invention, it is possible to provide an electric wire and an electric wire routing method that can prevent cracks in the orange-colored body located inside the transparent resin.

[0011] 1A and 1B are perspective views showing a first example of an electric wire according to an embodiment of the present invention, and a second example of an electric wire according to an embodiment of the present invention.

[0012] The present invention will be described below in accordance with preferred embodiments. Note that the present invention is not limited to the embodiments shown below and can be modified as appropriate without departing from the spirit of the present invention. In addition, in the embodiments shown below, some components are omitted from illustration and description, but it goes without saying that publicly known or well-known technologies are applied as appropriate to the details of the omitted technologies within the scope of the content described below.

[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 is a round conductor with a circular cross section. In this embodiment, the conductor 11 is assumed to be a single wire capable of handling high voltages and large currents, but is not limited to this and may be made of two or more members (for example, multiple twisted wires).

[0015] The orange-colored body 12 is provided on the conductor 11 and is a member having at least an outer periphery thereof colored orange. The orange-colored body 12 is formed, for example, from a resin tape (such as a vinyl tape), a cloth tape, or a braided cord. The resin tape and the cloth tape have an adhesive layer on one side and are longitudinally or spirally wound around the conductor 11 with the adhesive layer facing the conductor 11. The braided cord is formed by braiding a bundle of wires into a tubular shape and is provided on the conductor 11 by inserting the conductor 11 into the tubular shape. Note that all of these types of orange-colored bodies 12 are configured to withstand a temperature rise that occurs when a large current flows through the electric wire 1. Furthermore, the orange-colored body 12 is configured to withstand the temperature of the transparent resin 13 that is extrusion-coated onto the orange-colored body 12, as described below.

[0016] In this embodiment, orange is assumed to be a color with a Munsell value in the range of 10R6 / 16, 10R7 / 14, and 10R7 / 16. However, orange is not limited to this, and may be a color with a Munsell value in the range of 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 that coats the orange colored body 12. Specific examples of the transparent resin 13 include thermoplastic resins such as PC (Polycarbonate), PMMA (Polymethyl methacrylate), acrylic resin, and polystyrene. Examples of the transparent resin 13 include UV-curable resins such as urethane acrylate, epoxy acrylate, acrylic acrylate, and polyester acrylate. It is preferable that the transparent resin 13 have a thickness of 2 mm or less.

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

[0019] In the second example, the conductor 21 is a busbar conductor having a rectangular cross section. The 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. Furthermore, since the conductor 21 in the second example is a busbar conductor having a rectangular cross section, the orange-colored body 22 is provided on the conductor 21 so that its cross section is also rectangular. Furthermore, since the orange-colored body 22 has a rectangular cross section, the transparent resin 23 also coats the orange-colored body 22 so that its cross section is also rectangular.

[0020] In the electric wires 1, 2 according to the present embodiment, the orange color can be recognized from the outside because the orange-colored bodies 12, 22 are covered with the transparent resins 13, 23. This allows workers and others to recognize that the electric wires 1, 2 are for use with high voltages and large currents. Moreover, since the transparent resins 13, 23 are provided on the orange-colored bodies 12, 22, even if the electric wires 1, 2 are exposed to an abrasive environment, the transparent resins 13, 23 will wear away, making it difficult for the orange color to be lost.

[0021] Furthermore, in this embodiment, the conductors 11, 21 have a cross-sectional length in a predetermined direction in a cross section perpendicular to the longitudinal direction of the electric wires 1, 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. Furthermore, since the electric wire 2 shown in FIG. 2 is a busbar 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, 22 according to this embodiment have a thickness of 1 mm or less and an elongation percentage of at least 44.5%. As a result, when the electric wires 1, 2 are bent in a predetermined direction with a curvature radius R20, cracking of the orange-colored bodies 12, 22 is prevented due to the relationship between the strain applied to the orange-colored bodies 12, 22 and the elongation percentage. In other words, when the electric wires 1, 2 are routed while being bent in a predetermined direction with a curvature radius R20 or more, cracking of the orange-colored bodies 12, 22 is prevented.

[0023] If the orange-colored bodies 12, 22 are cracked, there is a possibility that the orange color may be overlooked by a worker or the like. However, the electric wires 1, 2 according to the present embodiment prevent cracking of the orange-colored bodies 12, 22 even when bent in a predetermined direction by R20. Therefore, the possibility of overlooking the orange-colored bodies 12, 22 due to cracking is reduced.

[0024] In the present embodiment, the orange-colored bodies 12, 22 preferably have an elongation rate of 62% or more. This is because, theoretically, if the elongation rate is 62% or more, cracking of the orange-colored bodies 12, 22 can be prevented even when the electric wires 1, 2 are bent at R10 in a predetermined direction. In other words, cracking can be prevented even when the electric wires are bent and routed in a narrower space.

[0025] Next, examples of the present invention and comparative examples will be described. Tables 1 and 2 below show examples of the present invention and comparative examples. Tables 1 and 2 also show the results of a bending test in which the orange-colored body was not coated with a transparent resin in order to check for cracks.

[0026]

[0027]

[0028] First, in Examples 1 to 25 and Comparative Examples 1 and 2 shown in Table 1, the orange-colored body is a vinyl tape attached longitudinally to 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 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. Furthermore, the cross-sectional length in a predetermined direction in a cross section perpendicular to the longitudinal direction of the conductor on which the orange-colored body is to be provided is 10 mm in Examples 1 to 3, 10 to 12, and 17 to 19, and 20 mm in Examples 4 to 6, 13, 14, 20 to 22, and Comparative Example 1. Furthermore, the cross-sectional length in the predetermined direction is 30 mm in Examples 7 to 9, 15, 16, 23 to 25, and Comparative Example 2.

[0029] The conductor and orange-colored body described above had a cross-sectional length in a predetermined direction of 10.18 mm in Examples 1 to 3 and 10 to 12, 20.18 mm in Examples 4 to 6, 13, and 14 and Comparative Example 1, and 30.18 mm in Examples 7 to 9, 15, and 16 and Comparative Example 2. The cross-sectional length in a predetermined direction of 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.

[0030] In addition, in Examples 26 to 41 and Comparative Examples 3 to 6 shown in Table 2, the orange-colored body is a PET (Polyethylene Terephthalate) resin cord (braided cord), and the conductor is inserted inside the resin cord, providing an outer surface for the conductor. The thickness of the resin cord 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 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. The cross-sectional length in a predetermined direction in a cross section perpendicular to the longitudinal direction of the conductor to which the orange-colored body is to be provided is 10 mm in Examples 27 to 29 and 35 to 37, and 20 mm in Examples 30, 31, 38, and 39 and Comparative Examples 3 and 5. The cross-sectional length in the predetermined direction is 30 mm in Examples 26, 32 to 34, 40, and 41, and Comparative Examples 4 and 6.

[0031] The conductor and orange-colored body described above had a cross-sectional length in a predetermined direction of 11 mm in Examples 27 to 29, 21 mm in Examples 30 and 31 and Comparative Example 3, and 31 mm in Examples 26, 32, and 33 and Comparative Example 4. The cross-sectional length in a predetermined direction of the whole was 12 mm in Examples 35 to 37, 22 mm in Examples 38 and 39 and Comparative Example 5, and 32 mm in Examples 34, 40, and 41 and Comparative Example 6.

[0032] A bending test was conducted on Examples 1 to 41 and Comparative Examples 1 to 6. In the bending test, a sample of each of Examples 1 to 41 and Comparative Examples 1 to 6 having a predetermined length, with one end fixed and the other end free, was placed around a mandrel and bent 180 degrees in a predetermined direction, and the presence or absence of cracks was confirmed by checking whether the conductor was exposed on the outside of the bend. When the conductor was confirmed to be exposed on the outside of the 180-degree bend, it was judged as having a crack ("X" in Tables 1 and 2), and when the conductor was not confirmed to be exposed, it was judged as having no crack ("O" in Tables 1 and 2).

[0033] The mandrels used were R10 in Examples 3, 6, 9, 12, 19, 22, 25, 29, and 37 and Comparative Examples 1 to 6, and R20 in Examples 2, 5, 8, 11, 14, 16, 18, 21, 24, 28, 31, 33, 36, 39, and 41. The mandrels used in Examples 1, 4, 7, 10, 13, 15, 17, 20, 23, 26, 27, 30, 32, 34, 35, 38, and 40 were R30.

[0034] The calculated strain amounts for Examples 1 to 12 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%, respectively. The calculated strain amounts for Examples 13 to 23 were 25.17%, 33.53%, 33.47%, 43.00%, 14.46%, 20.22%, 33.64%, 25.13%, 33.49%, 50.17%, and 33.44%, respectively.

[0035] The calculated strain amounts for Examples 24 to 35 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%, respectively. The calculated strain amounts for Examples 36 to 41 were 23.08%, 37.50%, 26.83%, 35.48%, 34.78%, and 44.44%, respectively. The calculated strain amounts for Comparative Examples 1 to 6 were 50.22%, 60.14%, 51.22%, 60.78%, 52.38%, and 61.54%, respectively.

[0036] In the above-described Examples 1 to 41, the elongation rate exceeded the calculated strain amount, and no cracks were confirmed in the bending test results. On the other hand, in the comparative examples 1 to 6, the elongation rate did not exceed the calculated strain amount, and cracks were confirmed in the bending test results.

[0037] The above experimental results showed that when the cross-sectional length of the conductor in the predetermined direction is 10 mm to 30 mm and the thickness of the orange-colored body is 1 mm or less, if the elongation of the orange-colored body is 44.5% or more, no cracks will occur when bent in the predetermined direction R20. Furthermore, the experimental results showed that when the elongation of the orange-colored body is both 160% and 180%, no cracks will occur when bent in the predetermined direction R10. In particular, from a calculation perspective, it can be said that when the cross-sectional length of the conductor in the predetermined direction is in the range of 10 mm to 30 mm and the elongation of the orange-colored body is 62% or more, no cracks will occur when bent in the predetermined direction R10.

[0038] Thus, in the electric wires 1 and 2 according to the present embodiment, the conductors 11 and 21 have a cross-sectional length in a predetermined direction 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 an elongation rate of at least 44.5%. Therefore, when the electric wires 1 and 2 are bent in a predetermined direction with an R of 20, cracking of the orange-colored bodies 12 and 22 is prevented. Therefore, it is possible to provide the electric wires 1 and 2 that can prevent cracking of the orange-colored bodies 12 and 22 located inside the transparent resins 13 and 23.

[0039] Furthermore, when the orange-colored bodies 12, 22 have an elongation percentage of 62% or more, cracks are prevented even when bent at an R of 10 in a predetermined direction. Therefore, it is possible to provide the electric wires 1, 2 in which cracks can be prevented in the orange-colored bodies 12, 22 even when the electric wires are bent more locally.

[0040] The present invention has been described above based on the embodiments, but the present invention is not limited to the above embodiments, and modifications may be made within the scope of the spirit of the present invention, and if possible, publicly known or well-known technologies may be combined.

[0041] For example, in this embodiment, the conductors 11 and 21 are not limited to being made of one material, but may be made of two or more materials. Also, the orange-colored bodies 12 and 22 are not limited to the Munsell colors exemplified above, as long as they are colored in the Munsell colors required for high-voltage and large-current electric wires.

[0042] Here, the features of the electric wire and the electric wire routing method according to the above-described embodiment of the present invention will be briefly summarized and listed below in [1] to [3].

[0043] [1] An electric wire (1, 2) comprising a conductor (11, 21), an orange-colored body (12, 22) provided on the conductor (11, 21), and a transparent resin (13, 23) coated on the orange-colored body (12, 22), wherein the conductor (11, 21) has a cross-sectional length (L1, L2, L3) in a predetermined direction in a cross section perpendicular to the longitudinal direction of the conductor (11, 21) of 10 mm or more and 30 mm or less, and the orange-colored body (12, 22) has a thickness of 1 mm or less and an elongation of at least 44.5%, and is prevented from cracking when bent at an R20 angle in the predetermined direction. [2] The electric wire according to [1] above, wherein the orange-colored body (12, 22) has an elongation of 62% or more and is prevented from cracking when bent at an R10 angle in the predetermined direction. [3] A method for routing an electric wire, comprising bending the electric wire according to the above [1] or [2] in the predetermined direction at an angle of R20 or more.

[0044] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

[0045] This application is based on a Japanese patent application (Patent Application No. 2024-003753) filed on January 15, 2024, the contents of which are incorporated herein by reference.

[0046] According to one aspect of the present invention, it is possible to provide an electric wire capable of preventing cracks in an orange-colored body located inside a transparent resin. The invention having this effect is useful for an electric wire and an electric wire routing method.

[0047] 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 thickness direction (cross-sectional length in a predetermined direction) L3: Length in width direction (cross-sectional length in a predetermined direction)

Claims

1. An electric wire comprising a conductor, an orange-colored body provided on the 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.

2. The electric wire according to claim 1, wherein 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.

3. A wiring method for an electric wire, wherein the electric wire according to claim 1 or 2 is bent at R20 or more in the predetermined direction and then wired.

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