Composite cable

Abstract

Composite cable (1) comprising: a signal line part (2) comprising a first signal line (21) and a second signal line (22), each composed of a pair of twisted wires (200), the first signal line (21) and the second signal line (22) being twisted together; a pair of power supply lines (3); and a sheath (4) covering an outer periphery of a wire bundle (6) composed of the signal line part (2) whose outer periphery is covered with a shield conductor (5) and the pair of power supply lines (3), the signal line part (2) and the pair of power supply lines (3) being twisted together; wherein the shielding conductor (5) is formed from a braid composed of a plurality of bare conductor wires (50) interwoven with one another.

Description

TECHNICAL FIELD

[0001] The present invention relates to a composite cable. GENERAL STATE OF THE ART

[0002] For several years, electrically controlled electric brakes have attracted interest in automotive technology. For example, Japanese patent JP 5 594 446 B2 discloses a composite cable for use in an electric brake, which includes a signal line composed of a pair of wires connected to a sensor for measuring a wheel rotational speed, and two power supply lines connected to a brake caliper.

[0003] DE 11 2017 000 062 T5 discloses a multi-core cable having a shielding layer formed by winding a metal tape on power lines, a twisted pair of signal lines and a twisted pair of electrical lines.

[0004] JP H05 - 38 713 U discloses a multi-core cable having a plurality of pairs of twisted wires, each covered by a first shielding layer, and a second shielding layer formed as part of a sheath of the entire cable.

[0005] US 2011 / 0 278 043 A1 discloses a multi-core cable with several wire pairs, wherein a part of the wire pairs is each surrounded by a shielding layer, and wherein the entire cable is surrounded by a shielding layer. SUMMARY OF THE INVENTION

[0006] However, in the conventional composite cable, when one end of the cable is fixed to a vehicle body and the other end of the cable is attached to a section around a wheel where vertical vibrations occur, the cable is subjected to vibrations caused by multiple shocks, especially large horizontal shocks (vibrations in the longitudinal direction of a vehicle), when subjected to vertical vibrations in a bent state. Therefore, the conventional composite cable has a problem that the signal line is easily severed around a section for fixing the cable.

[0007] The present invention has been made against this background and is intended to provide a composite cable that enables improvement in the resistance of a signal line to disconnection.

[0008] One aspect of the present invention is a composite cable comprising: a signal line part comprising a first signal line and a second signal line each composed of a pair of wires twisted together, the first signal line and the second signal line being twisted together; a pair of power supply lines; a sheath covering an outer periphery of a wire bundle composed of the signal line part whose outer periphery is covered with a shield conductor and the pair of power supply lines, the signal line part and the pair of power supply lines being twisted together; wherein the shielding conductor is formed of a braid composed of a plurality of bare conductor wires (conducting element wires) interwoven with each other. Effects of the invention

[0009] The composite cable has the above-mentioned configuration. Specifically, at the signal line portion of the composite cable, the outer periphery is covered with a shielding conductor formed of a braid composed of a plurality of interwoven bare wires. Compared with the conventional composite cable without a shielding conductor, the rigidity of the cable in the composite cable is improved by the shielding conductor. As a result, the horizontal vibration of the composite cable is restricted when subjected to vertical vibration in a bending state. Furthermore, since the shielding conductor restricts the movement of the bare wires when the cable is subjected to horizontal vibration, it is difficult for gaps to form between the windings of the element wires, the composite cable also exhibits excellent torsional strength.

[0010] Accordingly, the composite cable 1 enables an increase in the resistance of the first signal line 21 to separation. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an illustration schematically showing a composite cable according to Embodiment 1 in a cross section perpendicular to the central axis of the cable. Fig. 2 is an illustration schematically showing an external view of a signal line covered with a shield conductor in the composite cable according to Embodiment 1. Fig. 3 is an illustration schematically showing an application example of the composite cable according to Embodiment 1. Fig. 4 is an illustration schematically showing a composite cable according to Embodiment 2 in a cross section perpendicular to the central axis of the cable. Fig. 5 is an illustration schematically showing a composite cable according to Embodiment 3 not according to the invention in a cross section perpendicular to the central axis of the cable. DETAILED DESCRIPTIONRepresentative EmbodimentsEmbodiment 1

[0011] A composite cable of embodiment 1 is described with reference to Fig. 1 to Fig. 3. As described in Fig. 1 and Fig. 2, a composite cable 1 of the present embodiment includes a signal line part 2, a pair of power supply lines 3, and a sheath 4. A detailed explanation will be given below. Note that the dashed circles in Fig. 1 show wires to be arranged in strands and the arrows represent twisting directions.

[0012] The signal line part 2 comprises a first signal line 21 and a second signal line 22. The first signal line 21 and the second signal line 22 each consist of a pair of wires 200 twisted together. In the present embodiment, the twisting directions of the first signal line 21 and the second signal line 22 are the same as in Fig. 1. Furthermore, the pair of wires 200 each includes a conductor 201 and an insulator 202 covering the outer periphery of the conductor 201. The conductor 201 is composed of a plurality of bare metal wires twisted together. The bare metal wires may be formed of copper or a copper alloy, or of aluminum or an aluminum alloy, and so on. The insulator 202 may be formed of, for example, cross-linked polyethylene (PE) or the like.

[0013] The signal line part 2 consists of the first signal line 21 and the second signal line 22, which are twisted together. In the present embodiment, the twisting direction of the signal line part 2 is the same as those of the first signal line 21 and the second signal line 22, as shown in Fig. 1 shown.

[0014] As in Fig. 2, the signal line part 2 is covered with a shielding conductor 5. The shielding conductor 5 is formed of a braid composed of a plurality of intertwined bare wires 50. In the present embodiment, the braid serving as the shielding conductor 5 is formed into a tubular shape and is provided on the outer periphery of the signal line part 2 by inserting the signal line part 2 into the tubular braid.

[0015] Specifically, a bare metal wire can be used as the bare lead wires 50. Note that the metal mentioned in the present specification includes any alloy. Examples of the bare lead wires 50 include, for example, a tinned soft copper wire, a copper alloy wire, an aluminum wire, and an aluminum alloy wire, among others. In addition, a metal foil wire or the like formed by laterally winding a metal foil around the outer periphery of a plastic fiber can be used as the bare lead wires 50. Examples of the plastic fiber include, for example, an aramid fiber or the like. Examples of the metal foil include a copper foil, a copper alloy foil, or the like.In the case where a metal foil wire is used as the bare lead wires 50, this is advantageous in terms of improvements in the strength and flexibility of the shield conductor 5 compared to the case where a bare metal wire is used as the bare lead wires 50. In the case where a bare metal wire is used as the bare lead wires 50, this is advantageous in terms of reducing electrical resistance, reducing costs, and so on compared to the case where a metal foil wire is used as the bare lead wires 50.

[0016] Specifically, compared to the above-mentioned tinned soft copper wire, copper alloy wire, and copper foil wire (composed of aramid fiber and copper foil), in terms of tensile strength, the copper alloy wire has approximately three to four times higher strength than that of the base tinned soft copper wire. The copper foil wire has approximately six to eight times higher strength than the tinned soft copper wire. Thus, among such bare conductor wires 50, the copper foil wire is suitable for increasing the strength of the shielding conductor 5. Furthermore, compared to the above-mentioned tinned soft copper wire, copper alloy wire, and copper foil wire (composed of aramid fiber and copper foil), in terms of flexibility to repeated bending, the copper alloy wire has good bending compliance and good flexibility. The copper foil wire has very good flexibility to a greater extent than the copper alloy wire.Thus, among such bare conductor wires 50, the copper foil wire is suitable for increasing the flexibility of the shielding conductor 5. However, from the viewpoints of reducing electrical resistance and reducing costs, the tinned soft copper wire is advantageous. It should be noted that if the shielding conductor 5 is made of the metal foil itself or of a plastic tape with metal deposited thereon, it will break when the composite cable 1 is subjected to vertical vibration in a bent state. The reason why the metal foil wire has excellent flexibility despite the use of the metal foil is that the tensile stress is absorbed by the plastic fiber, so the metal foil is difficult to break.

[0017] In the present embodiment, each of the pair of power supply lines 3 includes a conductor 301 and an insulator 302, each covering the outer periphery of the conductor 301. The conductor 301 is composed of a plurality of bare metal wires twisted together. The bare metal wires may be formed of, for example, copper or copper alloy, or aluminum or aluminum alloy, and so on. The insulator 302 may be formed of, for example, cross-linked polyethylene (PE), etc. In addition, the outer diameters of the pair of power supply lines 3 are designed to be smaller than that of the signal line part 2.

[0018] In the composite cable 1, at least the signal line part 2, whose outer periphery is covered with the shielding conductor 5, and the pair of power supply lines 3 are twisted together into a wire bundle 6. In the present embodiment, the pair of power supply lines 3 are in contact with each other. Furthermore, the pair of power supply lines 3 is in contact with the shielding conductor 5 of the signal line part 2.

[0019] The outer periphery of the wire bundle 6 is covered with the sheath 4. The sheath 4 may be formed, for example, from polyurethane resin (PU) or the like.

[0020] In order to easily achieve a circular cable cross-section, in the present embodiment, an intermediate layer 7 can be arranged between the outer periphery of the wire bundle 6 and the sheath 4. The intermediate layer 7 can be made, for example, of a cross-linked polyethylene (PE) or the like. It should be noted that in the present embodiment, a space 8 is provided between the wire bundle 6 and the intermediate layer 7.

[0021] In the composite cable 1 of the present embodiment, the outer periphery of the signal line part 2 is covered with the shield conductor 5 formed of the braid composed of the plurality of intertwined bare wires 50. Furthermore, compared with the conventional composite cable in which no shield conductor is provided, the composite cable 1 improves the rigidity of the cable by the shield conductor 5. As a result, it is possible to restrict horizontal vibrations of the composite cable 1 when subjected to vertical vibrations in a bending state. Furthermore, since the shield conductor 5 restricts the movement of the bare wires 50 when the cable is subjected to horizontal vibrations, it is difficult for gaps to form between the windings of the element wires, and the composite cable has excellent torsional strength.

[0022] Accordingly, the composite cable 1 enables an increase in the resistance of the first signal line 21 and the second signal line 22 to separation.

[0023] In the present embodiment, the composite cable 1 is in such a state, specifically as shown in Fig. 3, one end side of the cable is fixed to a portion 91 on the stable side, and the other end side of the cable is attached to a vertically swinging portion 92. According to such a configuration, the above-mentioned operational effects can be securely achieved, so that the first signal line 21 and the second signal line 22 can be securely restricted from disconnection around the cable fixing portion. Next, a description will be given of the case where the composite cable 1 is applied to an automotive electric brake. Note that, in the automotive electric brake, a motor provided on a brake caliper is directly or indirectly driven by a main electronic control unit in accordance with a driver's pedaling force, and the rotational force of the motor is converted into a mechanical pressing pressure.As a result, the brake pad is pressed against the brake disc (in the case of a disc brake), or the brake shoe is pressed against the brake drum (in the case of a drum brake), thereby braking the motor vehicle.

[0024] When the composite cable 1 is applied to an automotive electric brake, one end of the composite cable 1 is specifically fixable to a vehicle body or chassis, and the other end of the cable may be attached to a portion around a wheel where vertical vibrations occur. Note that the portion around a wheel specifically includes the lower portion of the suspension of an automotive vehicle or the like (referred to as the underbody (chassis) of an automotive vehicle). Further, the composite cable 1 may be fixed at one or more locations on one end of the cable. Likewise, the composite cable 1 may be fixed at one or more locations on the other end of the cable. For fixing the composite cable 1 as mentioned above, a fixing bracket 911 may be used, and for attaching the composite cable 1 as mentioned above, an attachment bracket 922 may be used.

[0025] In the present embodiment, the main electronic control unit (a main ECU) is mounted on a vehicle body or chassis. Further, one or more subordinate electronic control units (a sub ECU) are mounted on a wheel and / or a portion around a wheel. Furthermore, a wheel speed sensor for detecting the rotational speed of the wheel is mounted on a wheel and / or a portion around a wheel.In addition to the wheel speed sensor, various sensors for measurements are provided on a wheel and / or a portion around a wheel to detect information necessary for controlling a motor, such as a motor operation confirmation sensor for confirming the operation of the motor provided on the brake caliper of the automotive electric brake, a motor temperature sensor for measuring the temperature of the motor, a motor rotation angle sensor for measuring the rotation angle of the motor, a motor current sensor for measuring the current supplied to the motor, a contact pressure sensor for detecting the braking force, and the like.

[0026] In the present embodiment, the first signal line 21 may be configured to transmit an electrical signal related to the rotational speed of the wheel. The second signal line 22 may be configured to transmit at least one electrical signal related to the control of the motor. The pair of power supply lines 3 may be configured to supply electric power for driving the motor. According to this configuration, even when one end side of the composite cable 1 is fixed to the vehicle body or the chassis, the first signal line 21 and the second signal line 22 are difficult to disconnect around the cable fixing portion. Thus, the composite cable 1 is advantageous for improving the durability of an electric brake and increasing reliability.

[0027] In the above case, the first signal line 21 may be specifically connected to the main electronic control unit at one end of the cable and to the wheel speed sensor at the other end of the cable. The second signal line 22 may be specifically connected to the main electronic control unit at one end of the cable and to the subordinate electronic control unit at the other end of the cable. Various sensors for measurement may be connected to the subordinate electronic control unit to acquire information necessary for controlling the engine. It is noted that the various sensors may be connected to the subordinate electronic control unit through a pair of sensor signal lines provided in the sensors, respectively.Each of the pair of power supply lines 3 may be specifically connected to the main electronic control unit at one end of the cable and to the subordinate electronic control unit at the other end of the cable. In this case, a three-phase AC motor may be used as the motor, and the motor may be connected to the subordinate electronic control unit through a wheel-side motor power supply line. Otherwise, each of the pair of power supply lines 3 may be connected to the main electronic control unit at one end of the cable and directly to the motor at the other end of the cable. In this case, a DC motor may be used as the motor. It is noted that the main electronic control unit and the subordinate electronic control unit may be configured to be communicable via the second signal line 22 of the composite cable 1.

[0028] In the case of applying the composite cable 1 to an electric brake, although the electric brake can be applied to either a front wheel or a rear wheel, the electric brake is preferably applied to a front wheel. The front wheel of a motor vehicle rotates right and left due to steering. Therefore, the composite cable 1 applied to an electric brake for a front wheel is subjected not only to vertical vibrations in a bending state but also to torsional force. Since the shield conductor 5 is formed of the braid, even when torsional force is applied, gaps between the windings of the element wire are hardly expanded, so satisfactory torsional strength is achieved. For this reason, according to the configuration in which the composite cable 1 is applied to the electric brake for a front wheel, the above-mentioned operational effects can be easily achieved to the fullest extent. Embodiment 2

[0029] A composite cable according to embodiment 2 is described with reference to Fig. 4 described.

[0030] As in Fig. 4, according to the present embodiment, the composite cable 1 includes a ground wire 61. Specifically, the wire bundle 6 further includes the ground wire 61 twisted together with the signal line part 2 and the pair of power supply lines 3.

[0031] According to this configuration, the following advantages are provided. Specifically, in the case of applying the composite cable 1 to an electric brake, the shield conductor 5 of the composite cable 1 according to Embodiment 1 can be grounded to the vehicle body or chassis at one end of the cable. However, the other end of the cable is located on the wheel side, and thus grounding the shield conductor 5 is difficult. In contrast, in the case of the present embodiment in which the wire bundle 6 includes the ground wire 61, the shield conductor 5 and the ground wire 61 can be connected at the other end of the cable. As a result, the above-mentioned configuration has the advantage that the shielding performance achieved by the shield conductor 5 can be assuredly achieved even under conditions where grounding at the wheel side of the vehicle would be limited.

[0032] Note that the ground wire 61 may be specifically configured to include a conductor 601 and an insulator 602 covering the outer periphery of the conductor 601. The conductor 601 may be formed, for example, from copper or copper alloy, or from aluminum or aluminum alloy. The insulator 602 may be formed, for example, from cross-linked polyethylene (PE) or the like. Fig. Although FIG. 4 shows an example in which the ground wire 61 is arranged on the same side as the signal line part 2, the ground wire 61 may be arranged on the side opposite to the signal line part 2 with the pair of power supply lines 3 interposed therebetween. The other configurations and operational effects are the same as in Embodiment 1. Non-inventive embodiment 3

[0033] A composite cable according to non-inventive embodiment 3 is described with reference to Fig. 5 described.

[0034] As in Fig. 5, according to the present embodiment, the signal line part 2 of the composite cable 1 includes the first signal line 21 and does not include the second signal line 22. In other words, the present embodiment is an example in which the signal line part 2 is composed of the first signal line 21. Accordingly, the shield conductor 5 is formed of the braid covering the outer periphery of the first signal line 21 serving as the signal line part 2. According to this configuration, even when one end side of the composite cable 1 is fixed to the vehicle body or the chassis, the first signal line 21 is difficult to cut off around the cable fixing portion.

[0035] In the case of applying the composite cable 1 of the present embodiment to an automotive electric brake, the first signal line 21 of the composite cable 1 may be configured to transmit an electrical signal related to the rotational speed of a wheel, or may be configured to transmit at least one electrical signal related to the control of the motor. In the former case, the electric brake may be constituted by further using each other signal line separately for transmitting at least the electrical signal related to the control of the motor in addition to the composite cable 1. Likewise, in the latter case, the electric brake may be further constituted by further using each other signal line separately for transmitting the electrical signal related to the rotational speed of the motor in addition to the composite cable 1. List of reference symbols 1 composite cable 2 Signal line part 21 first signal line 22 second signal line 200 wire 3 Power supply line 4 coats 5 shielding conductors 50 Bare Conductor Wire 6 wire bundles

Claims

[1] Composite cable (1) comprising: a signal line part (2) comprising a first signal line (21) and a second signal line (22), each composed of a pair of twisted wires (200), the first signal line (21) and the second signal line (22) being twisted together; a pair of power supply lines (3); and a sheath (4) covering an outer periphery of a wire bundle (6) composed of the signal line part (2) whose outer periphery is covered with a shield conductor (5) and the pair of power supply lines (3), the signal line part (2) and the pair of power supply lines (3) being twisted together; wherein the shielding conductor (5) is formed from a braid composed of a plurality of bare conductor wires (50) interwoven with one another. [2] A composite cable (1) according to claim 1, wherein each bare conductor wire (50) is a bare metal wire or a metal foil wire formed by spirally winding a metal foil around an outer periphery of a plastic fiber. [3] The composite cable (1) according to any one of claims 1 to 2, wherein the wire bundle (6) further comprises a ground wire (61) twisted with the signal line part (2) and the pair of power supply lines (3). [4] Composite cable (1) according to claim 3, wherein the shielding conductor (5) and the grounding wire (61) are connected to each other at one of the ends of the cable. [5] The composite cable (1) according to any one of claims 1 to 4, wherein one end side of the cable is adapted to be stably fixed, and another end side of the cable is adapted to be attached to a portion where vertical vibrations are generated. [6] Composite cable (1) according to claim 1, wherein the cable is intended for use in an electric motor vehicle brake, one end of the cable is designed to be fixed to a vehicle body or chassis, and the other end of the cable is designed to be attached to a portion around a wheel where vertical vibrations occur, the first signal line (21) is designed to send an electrical signal relating to a rotational speed of a wheel, the second signal line (22) is designed to send at least one electrical signal relating to the control of a motor provided on a brake caliper of the electric brake, and the pair of power supply lines (3) is adapted to supply electrical power for driving the motor. [7] Composite cable (1) according to claim 6, wherein the electric brake is an electric front wheel brake.

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