Shield cable

Abstract

To provide a shield cable excellent in heat resistance, flexibility, and low-temperature bendability.SOLUTION: The shield cable includes a central conductor, an insulator arranged on the outer peripheral side of the central conductor, a shield arranged on the outer peripheral side of the insulator, and a sheath arranged on the outer peripheral side of the shield. The insulator contains a crosslinked mixture containing an ethylene-propylene rubber and an ethylene-methyl acrylate copolymer. The sheath contains the mixture, an ethylene-propylene-diene rubber, or a thermoplastic urethane.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a shielded cable.

Background Art

[0002] Patent Document 1 discloses a shielded cable. The shielded cable is, for example, a cable for an IWM (in-wheel motor). The shielded cable includes a center conductor, an insulator, a shield, and a sheath. The insulator is disposed on the outer peripheral side of the center conductor. The shield is disposed on the outer peripheral side of the insulator. The sheath is disposed on the outer peripheral side of the shield.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Heat resistance, flexibility, and low-temperature bendability are required for shielded cables. In one aspect of the present disclosure, it is preferable to provide a shielded cable excellent in heat resistance, flexibility, and low-temperature bendability.

Means for Solving the Problems

[0005] One aspect of the present disclosure is a shielded cable including a center conductor, an insulator disposed on the outer peripheral side of the center conductor, a shield disposed on the outer peripheral side of the insulator, and a sheath disposed on the outer peripheral side of the shield. The insulator includes ethylene propylene rubber and an ethylene methyl acrylate copolymer, and includes a crosslinked mixture. The sheath includes the mixture, ethylene propylene diene rubber, or thermoplastic urethane.

[0006] A shielded cable, which is one aspect of the present disclosure, is excellent in heat resistance, flexibility, and low-temperature bendability.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0008] Exemplary embodiments of the present disclosure will be described with reference to the drawings. <First Embodiment> 1. Configuration of the shielded cable 1 Based on FIGS. 1 and 2, the configuration of the shielded cable 1 will be described. As shown in FIG. 1, the shielded cable 1 is a linear member. The shielded cable 1 is, for example, a cable for IWM.

[0009] As shown in FIG. 2, the shielded cable 1 includes a center conductor 3. The center conductor 3 is at the center of the shielded cable 1 in a cross-section orthogonal to the longitudinal direction of the shielded cable 1 (hereinafter referred to as the orthogonal cross-section). The center conductor 3 is composed of a plurality of conductor strands. The conductor strands are made of, for example, copper, copper alloy, etc. The conductor strands may be tinned soft copper wires.

[0010] The plurality of conductor strands are, for example, twisted together. The twisting direction of the conductor strands is defined as follows. As shown in FIG. 1, a virtual point P is assumed on one conductor strand. The point P is moved along the longitudinal direction of the conductor strand.

[0011] At this time, point P moves in the X direction shown in FIG. 1 in the longitudinal direction of the shield cable 1. Observe point P from the viewing point A shown in FIG. 1. The viewing point A is a point in the X direction with respect to the shield cable 1. The moving direction of point P as viewed from the viewing point A is clockwise CW around the center conductor 3 or counterclockwise CCW around the center conductor 3, as shown in FIG. 2. The moving direction of point P as viewed from the viewing point A is defined as the twisting direction of the conductor strands.

[0012] The center conductor 3 includes, for example, a plurality of bundles formed by stranding a plurality of conductor strands. The plurality of bundles are further stranded together. Also, the center conductor 3 is not limited to being a product of stranding a plurality of bundles, and may be a product of twisting together one bundle composed of a plurality of conductor strands. In these cases, the twisting direction of the conductor strands is defined as follows. Assume a virtual point P on one bundle. Move point P along the longitudinal direction of the bundle.

[0013] At this time, point P moves in the X direction shown in FIG. 1 in the longitudinal direction of the shield cable 1. Observe point P from the viewing point A shown in FIG. 1. The viewing point A is a point in the X direction with respect to the shield cable 1. The moving direction of point P as viewed from the viewing point A is clockwise CW around the center conductor 3 or counterclockwise CCW around the center conductor 3, as shown in FIG. 2. The moving direction of point P as viewed from the viewing point A is defined as the twisting direction of the conductor strands.

[0014] As shown in FIG. 2, the shield cable 1 includes an insulator 5. In the orthogonal cross-section, the insulator 5 is disposed on the outer peripheral side of the center conductor 3. For example, the outer peripheral surface of the center conductor 3 and the inner peripheral surface of the insulator 5 are in contact. For example, the thickness of the insulator 5 is constant regardless of the position in the circumferential direction.

[0015] The insulator 5 includes ethylene propylene rubber and an ethylene methyl acrylate copolymer, and includes a cross-linked mixture (hereinafter referred to as a specific mixture). The insulator 5 does not include components other than the specific mixture, excluding inevitable impurities, for example. The insulator 5 may include components other than the specific mixture, for example, within a range that does not prevent the solution of the problems of the present disclosure.

[0016] The specific mixture can be produced, for example, by mixing an ethylene propylene rubber and an ethylene methyl acrylate copolymer to form a mixture and crosslinking the mixture. As shown in FIG. 2, the shielded cable 1 includes a shield 7. The shield 7 is disposed on the outer peripheral side of the insulator 5 in the orthogonal cross-section. For example, the thickness of the shield 7 is constant regardless of the position in the circumferential direction. The shield 7 is, for example, a braided shield. Examples of the braided shield include a copper foil wire braid, a solid copper wire braid, a copper alloy braid, etc. The shield 7 is, for example, thinner than the insulator 5.

[0017] As shown in FIG. 2, the shielded cable 1 includes a sheath 9. The sheath 9 is disposed on the outer peripheral side of the shield 7 in the orthogonal cross-section. In the present embodiment, the inner peripheral surface of the sheath 9 is in contact with the outer peripheral surface of the shield 7.

[0018] For example, the thickness of the sheath 9 is constant regardless of the position in the circumferential direction. The sheath 9 is, for example, thicker than the insulator 5. The sheath 9 is, for example, thinner than the insulator 5 and thicker than the shield 7. The sheath 9 includes, for example, the specific mixture. The sheath 9 contains, for example, no components other than the specific mixture, excluding inevitable impurities. The sheath 9 may contain, for example, components other than the specific mixture within a range that does not prevent the solution of the problems of the present disclosure. The specific mixture in the sheath 9 is, for example, the same as the specific mixture in the insulator 5.

[0019] The sheath 9 may include, for example, an ethylene propylene diene rubber. The sheath 9 contains, for example, no components other than the ethylene propylene diene rubber, excluding inevitable impurities. The sheath 9 may contain, for example, components other than the ethylene propylene diene rubber within a range that does not prevent the solution of the problems of the present disclosure.

[0020] Also, the sheath 9 may contain, for example, thermoplastic urethane. The sheath 9 contains no components other than thermoplastic urethane, excluding inevitable impurities. The sheath 9 may contain components other than thermoplastic urethane, for example, within a range that does not prevent the solution of the problems of the present disclosure. For example, a bracket is attached to the sheath 9 directly or via an intervening member such as rubber.

[0021] As shown in FIG. 2, the shielded cable 1 includes a first tape layer 11. The first tape layer 11 is disposed between the insulator 5 and the shield 7 in a cross-sectional view perpendicular to the axis. For example, the outer peripheral surface of the first tape layer 11 is in contact with the inner peripheral surface of the shield 7. For example, the inner peripheral surface of the first tape layer 11 is in contact with the outer peripheral surface of the insulator 5.

[0022] The first tape layer 11 is made of paper, non-woven fabric, or resin tape. Preferably, the first tape layer 11 contains no metal, excluding inevitable impurities. The first tape layer 11 is formed, for example, by spirally winding a strip-shaped tape. The tape is made of paper, non-woven fabric, or resin tape. The resin tape is preferably made of foamed resin. The foamed resin is preferably, for example, foamed polypropylene or foamed polyethylene. The winding direction in the first tape layer 11 is defined as follows.

[0023] Assume a virtual point P on the tape constituting the first tape layer 11. Move the point P along the longitudinal direction of the tape. At this time, the point P moves in the X direction shown in FIG. 1 in the longitudinal direction of the shielded cable 1. Observe the point P from the viewing point A shown in FIG. 1. The moving direction of the point P as viewed from the viewing point A is clockwise CW around the center conductor 3 or counterclockwise CCW around the center conductor 3, as shown in FIG. 2. The moving direction of the point P as viewed from the viewing point A is defined as the winding direction in the first tape layer 11.

[0024] The winding direction in the first tape layer 11 is preferably opposite to the twisting direction of the conductor strands in the center conductor 3. In the present embodiment, the twisting direction of the conductor strands in the center conductor 3 is the parent twisting direction in the center conductor 3. The first tape layer 11 is preferably thinner than the shield 7.

[0025] The winding pitch of the first tape layer 11 is preferably not less than 2 times and not more than 5 times the diameter of the insulator 5. The winding pitch of the first tape layer 11 is the distance that the tape advances in the longitudinal direction of the shield cable 1 when the tape constituting the first tape layer 11 makes one turn.

[0026] 1. Effects exhibited by the shield cable 1 (1A) The insulator 5 contains a specific mixture. Also, the sheath 9 contains a specific mixture, ethylene propylene diene rubber, or thermoplastic urethane. Therefore, the shield cable 1 is excellent in heat resistance, flexibility, and low-temperature bending durability. Low-temperature bending durability means the property of being difficult to be damaged even when bending is repeated in a low-temperature environment.

[0027] (1B) The shield cable 1 further includes a first tape layer 11. The first tape layer 11 is disposed between the insulator 5 and the shield 7. The first tape layer 11 is made of paper, non-woven fabric, or resin tape.

[0028] The first tape layer 11 suppresses damage to the shield 7 when the shield cable 1 is bent. The reason is presumably as follows. If the shield 7 is fixed to the insulator 5, when the shield cable 1 is bent, stress is applied from the insulator 5 to the shield 7, and the shield 7 may be damaged.

[0029] When the first tape layer 11 is present, it is difficult for the shield 7 to adhere to the insulator 5. Therefore, when the shield cable 1 is bent, the shield 7 can easily move in the longitudinal direction of the shield 7 with respect to the insulator 5. As a result, when the shield cable 1 is bent, it is difficult for stress to be applied from the insulator 5 to the shield 7, and the shield 7 is difficult to be damaged.

[0030] (1C) The twisting direction of the plurality of conductor strands in the central conductor 3 is opposite to the winding direction in the first tape layer 11. Therefore, the twist of the shield cable 1 caused by the twisting of the plurality of conductor strands in the central conductor 3 can cancel out the twist of the shield cable 1 caused by winding the first tape layer 11. As a result, the twist of the shield cable 1 can be suppressed. <Second Embodiment> 1. Differences from the First Embodiment Since the basic configuration of the second embodiment is the same as that of the first embodiment, the differences will be described below. The same reference numerals as those in the first embodiment denote the same components, and reference is made to the previous description.

[0031] In the first embodiment described above, the inner peripheral surface of the sheath 9 was in contact with the outer peripheral surface of the shield 7. In contrast, the second embodiment is different from the first embodiment in that, as shown in FIG. 3, it further includes a second tape layer 13.

[0032] The second tape layer 13 is disposed between the shield 7 and the sheath 9 in the orthogonal cross-section. For example, the inner peripheral surface of the second tape layer 13 is in contact with the outer peripheral surface of the shield 7. For example, the outer peripheral surface of the second tape layer 13 is in contact with the inner peripheral surface of the sheath 9.

[0033] The second tape layer 13 is made of paper, non-woven fabric, or resin tape. The second tape layer 13 preferably does not contain metal except for inevitable impurities. The second tape layer 13 is formed, for example, by spirally winding a strip-shaped tape. The tape is made of paper, non-woven fabric, or resin tape. The resin tape is preferably made of foamed resin. The foamed resin is, for example, foamed polypropylene or foamed polyethylene. The second tape layer 13 is, for example, thinner than the shield 7. The tape of the second tape layer 13 is preferably the same as the tape of the first tape layer 11. In this case, it becomes possible to share the tape of the second tape layer 13 and the tape of the first tape layer 11.

[0034] The winding direction in the second tape layer 13 is defined as follows. Assume a virtual point P on the tape constituting the second tape layer 13. Move the point P along the longitudinal direction of the tape. At this time, in the longitudinal direction of the shield cable 1, the point P moves in the X direction shown in FIG. 1. Observe the point P from the viewing point A shown in FIG. 1. The moving direction of the point P as viewed from the viewing point A is clockwise CW around the center conductor 3 or counterclockwise CCW around the center conductor 3, as shown in FIG. 2. The moving direction of the point P as viewed from the viewing point A is defined as the winding direction in the second tape layer 13.

[0035] The winding direction in the second tape layer 13 is preferably the same direction as the twisting direction of the conductor strands in the center conductor 3. The winding direction in the second tape layer 13 is preferably the opposite direction to the winding direction in the first tape layer 11.

[0036] The second tape layer 13 is preferably thinner than the shield 7. The winding pitch of the second tape layer 13 is preferably not less than 2 times and not more than 5 times the diameter of the insulator 5. The winding pitch of the second tape layer 13 is the distance that the tape advances in the longitudinal direction of the shield cable 1 when the tape constituting the second tape layer 13 makes one turn.

[0037] 2. Effects of the shield cable 1 According to the second embodiment described in detail above, the effects of the first embodiment described above are achieved, and furthermore, the following effects are achieved.

[0038] (2A) The shield cable 1 further includes a second tape layer 13. The second tape layer 13 is disposed between the sheath 9 and the shield 7. The second tape layer 13 is made of paper, non-woven fabric, or resin tape.

[0039] The second tape layer 13 further suppresses damage to the shield 7 when the shield cable 1 is bent. The reason is presumed as follows. If the shield 7 is fixed to the sheath 9, when the shield cable 1 is bent, stress is applied from the sheath 9 to the shield 7, and the shield 7 may be damaged.

[0040] When the second tape layer 13 exists, it is difficult for the shield 7 to adhere to the sheath 9. Therefore, when the shield cable 1 is bent, the shield 7 can easily move in the longitudinal direction of the shield 7 with respect to the sheath 9. As a result, when the shield cable 1 is bent, it is difficult for stress to be applied from the sheath 9 to the shield 7, and the shield 7 is difficult to be damaged.

[0041] (2B) The first tape layer 11 and the second tape layer 13 are each wound in a spiral shape. The winding direction in the first tape layer 11 and the winding direction in the second tape layer 13 are opposite directions. Therefore, the twist of the shield cable 1 caused by winding the first tape layer 11 and the twist of the shield cable 1 caused by winding the second tape layer 13 can be offset. As a result, the twist of the shield cable 1 can be suppressed. <Other embodiments> As described above, the embodiments of the present disclosure have been described, but the present disclosure is not limited to the above-described embodiments and can be implemented with various modifications.

[0042] (1) The shield cable 1 may not include either the first tape layer 11 or the second tape layer 13. The shield cable 1 may not include the first tape layer 11 and may include the second tape layer 13.

[0043] (2) The winding direction in the first tape layer 11 and the winding direction in the second tape layer 13 may be the same direction. The twisting direction of the plurality of conductor strands in the center conductor 3 may be the same direction as the winding direction in the first tape layer 11. The twisting direction of the plurality of conductor strands in the center conductor 3 may be the opposite direction to the winding direction in the second tape layer 13.

[0044] (3) The winding method of the tape in the first tape layer 11 and the second tape layer 13 does not have to be spiral, and for example, it may be stacked vertically. (4) The functions of one component in each of the above embodiments may be shared among a plurality of components, or the functions of a plurality of components may be exhibited by one component. Also, a part of the configuration of each of the above embodiments may be omitted. Further, at least a part of the configuration of each of the above embodiments may be added to, replaced with, etc. the configuration of other above embodiments.

[0045] (5) In addition to the shielded cable 1 described above, the present disclosure can also be realized in various forms such as a system having the shielded cable 1 as a component, a manufacturing method of the shielded cable 1, and the like.

Explanation of Reference Numerals

[0046] 1... Shielded cable, 3... Central conductor, 5... Insulator, 7... Shield, 9... Sheath, 11... First tape layer, 13... Second tape layer

Claims

1. A central conductor, an insulator disposed on the outer peripheral side of the central conductor, a shield disposed on the outer peripheral side of the insulator, a sheath disposed on the outer peripheral side of the shield, comprising: the insulator includes ethylene propylene rubber and an ethylene methyl acrylate copolymer, and includes a crosslinked mixture, the sheath includes the mixture, ethylene propylene diene rubber, or thermoplastic urethane, a shielded cable.

2. The shielded cable according to claim 1, further comprising a first tape layer disposed between the insulator and the shield and made of paper, non-woven fabric, or resin tape. a shielded cable.

3. The shielded cable according to claim 2, wherein the first tape layer is wound in a spiral shape, the central conductor is formed by twisting a plurality of conductor strands, and the twisting direction of the plurality of conductor strands is opposite to the winding direction in the first tape layer. a shielded cable.

4. The shielded cable according to claim 2 or 3, further comprising a second tape layer disposed between the shield and the sheath and made of paper, non-woven fabric, or resin tape. a shielded cable.

5. The shielded cable according to claim 4, wherein the first tape layer and the second tape layer are each wound in a spiral shape, and the winding direction in the first tape layer is opposite to the winding direction in the second tape layer. a shielded cable.

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