Cable for electric brakes

Abstract

To provide a cable for an electric brake that is able to prevent a situation in which a current cannot be supplied to an electric brake device.SOLUTION: A cable 3 for an electric brake supplies a three-phase alternating current to an electric motor 201 of an electric brake device 2 that uses the electric motor 201 as a power source. The cable 3 for the electric brake includes: a first wire group 31 including a first U phase wire 311, a first V phase wire 312, and a first W phase wire 313; a second wire group 32 including a second U phase wire 321, a second V phase wire 322, and a second W phase wire 323; a tape member 33 wound around an outer periphery of a twisted body 30 obtained by twisting the first wire group 31 and the second wire group 32; and a sheath 34 covering an outer periphery of the tape member 34. Both the first wire group 31 and the second wire group 32 are redundantly connected to the electric motor 201.SELECTED DRAWING: Figure 3

Description

Technical Field

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[0001] The present invention relates to a cable for an electric brake of a vehicle.

Background Art

[0002] In recent years, instead of a hydraulic brake device, an electric brake device using an electric motor as a power source, as described in Patent Documents 1 and 2, for example, is increasingly being used. Such an electric brake device does not require negative pressure generated by an engine or negative pressure generated by an electric vacuum pump, and thus is particularly being considered for adoption in electric vehicles and so-called hybrid vehicles. In those described in Patent Documents 1 and 2, as the electric motor, a three-phase motor to which a three-phase alternating current generated by an inverter is supplied is used.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the electric brake device as described above, a three-phase alternating current is supplied by a cable stretched between the vehicle body side. If this cable is damaged due to, for example, a flying stone or bending fatigue due to long-term use, the braking force of the wheel braked by the electric brake device to which the cable is connected may become insufficient, and thus an improvement in reliability is required.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a cable for an electric brake capable of suppressing the occurrence of a situation where current cannot be supplied to an electric brake device. [Means for solving the problem]

[0006] The present invention aims to solve the above problems and provides an electric brake cable for supplying a three-phase alternating current to an electric motor in an electric brake device powered by an electric motor, comprising: a first wire group having a first U-phase wire, a first V-phase wire, and a first W-phase wire; a second wire group having a second U-phase wire, a second V-phase wire, and a second W-phase wire; a tape member wrapped around the outer circumference of a twisted body formed by twisting the first and second wire groups together; and a sheath covering the outer circumference of the tape member, wherein both the first and second wire groups are redundantly connected to the electric motor. [Effects of the Invention]

[0007] According to the electric brake cable of the present invention, it is possible to suppress the occurrence of situations in which current cannot be supplied to the electric brake device. [Brief explanation of the drawing]

[0008] [Figure 1] (a) is an external view showing a vehicle having an electric brake system according to a first embodiment of the present invention. (b) is a configuration diagram showing the area around one of the multiple wheels of the vehicle. [Figure 2] This is a schematic diagram showing an example configuration of an electric brake system, including the electric brake device, inverter circuit, and switching circuit. [Figure 3] (a) is a side view showing the configuration of the power cable. (b) is a cross-sectional view of the power cable in line AA of (a). [Figure 4] This is a cross-sectional view of a power cable according to the second embodiment. [Figure 5] This is a cross-sectional view of an electric brake cable according to a third embodiment. [Modes for carrying out the invention]

[0009] [First Embodiment] Figure 1(a) is an external view showing a vehicle 1 having an electric brake system 2 according to a first embodiment of the present invention. Figure 1(b) is a configuration diagram showing the peripheral area of ​​one of the multiple wheels 10 of the vehicle 1. The electric brake system 2 comprises an electric brake device 20, an inverter circuit 21, a power line switching circuit 22 and a signal line switching circuit 23, a control device 24 that controls the inverter circuit 21 and the power line switching circuit 22 and signal line switching circuit 23, a power line cable 3 that supplies three-phase AC current to the electric brake device 20, and a pair of signal line cables 41 and 42 that transmit signals between the electric brake device 20 and the control device 24. The power line cable 3 is one embodiment of the electric brake cable of the present invention.

[0010] The electric brake device 20 is supported via the suspension device 12 so as to be vertically movable relative to the vehicle body 11 together with the knuckle 13 and hub unit 14. The hub unit 14 has an outer ring 141 fixed to the knuckle 13 by a plurality of bolts 140, and a hub wheel 142 rotatably supported relative to the outer ring 141. The hub wheel 142 is provided with a wheel mounting flange 142a, and the wheel 10 and brake rotor 15 are attached to this wheel mounting flange 142a by a plurality of hub bolts 143. The electric brake device 20 generates frictional force by pressing the brake pad 200 against the brake rotor 15, thereby braking the wheel 10.

[0011] Vehicle 1 is equipped with a DC power supply 100 that outputs a DC voltage to an inverter circuit 21. The inverter circuit 21 switches the DC voltage output from the DC power supply 100 to generate a three-phase AC current. The generated three-phase AC current is supplied to the electric brake device 20 via a power line cable 3.

[0012] Figure 2 is a schematic diagram showing an example configuration of the electric brake device 20, inverter circuit 21, power line switching circuit 22, and signal line switching circuit 23 of the electric brake system 2. The electric brake device 20 has an electric motor 201 as a power source. The electric motor 201 is a three-phase AC motor having U-phase windings, V-phase windings, and W-phase windings in its stator. In this embodiment, the electric brake system 2 has one inverter circuit 21 and one electric motor 201 corresponding to one wheel 10. The electric brake device 20 also has a motion conversion mechanism 202 that converts the rotation of the electric motor 201 into linear motion of the brake pad 200. The motion conversion mechanism 202 is composed of, for example, a ball screw mechanism or a rack and pinion mechanism.

[0013] The electric brake device 20 also includes an angle sensor 203 for detecting the rotation angle of the rotor relative to the stator of the electric motor 201, a load sensor 204 for detecting the pressing reaction force of the brake rotor 15 acting on the brake pads 200, and a temperature sensor 205 for detecting the temperature of the electric motor 201. The control device 24 controls the electric motor 201 based on the detection signals from these sensors.

[0014] The inverter circuit 21 has six three-phase bridge-connected switching elements 211 and a freewheeling diode 212 connected in parallel to each switching element 211. Each switching element 211 switches between an on state and an off state by a PWM (Pulse Width Modulation) signal from the control device 24. The control device 24 generates a three-phase alternating current to be supplied to the electric motor 201 of the electric brake device 20 by PWM control based on the detection signal from the angle sensor 203.

[0015] The power line switching circuit 22 is, for example, composed of a triple relay circuit. The control device 24 controls the power line switching circuit 22 and switches whether the three-phase AC current generated by the inverter circuit 21 is supplied to the electric motor 201 by the first wire group 31 of the power line cable 3 (described later) or by the second wire group 32. In this embodiment, the switching is performed on the inverter side, but it is also possible to switch on the caliper side. Furthermore, it is also possible to have a dual system without switching.

[0016] The power line cable 3 and the first and second signal line cables 41 and 42 are routed with a portion of their longitudinal direction slack between the electric brake device 20 and the vehicle body 11 so as to accommodate the vertical movement of the wheels 10 relative to the vehicle body 11 and the twisting caused by steering. Detection signals from the angle sensor 203, load sensor 204, and temperature sensor 205 are transmitted to the control device 24 via either of the pair of signal line cables 41 or 42.

[0017] The signal line switching circuit 23 can switch which of the pair of signal line cables 41 and 42 transmits the detection signals from the angle sensor 203, load sensor 204, and temperature sensor 205 to the control device 24. The signal line switching circuit 23 is configured, for example, by a relay circuit. In this embodiment, the signal line cables 41 and 42 are made redundant in this way.

[0018] For example, if one of the signal cables 41 and 42, signal cable 41, is designated as the primary system, then the other signal cable 42 becomes the backup system. In this case, when an abnormality occurs in one of the signal cables 41, the control device 24 controls the signal line switching circuit 23, so that the detection signals from the angle sensor 203, load sensor 204, and temperature sensor 205 are transmitted to the control device 24 via the other signal cable 42. The control device 24 detects that an abnormality has occurred in one of the signal cables 41 if, for example, the detection signal from any of the angle sensor 203, load sensor 204, and temperature sensor 205 is no longer being sent normally through that signal cable 41.

[0019] FIG. 3(a) is a side view showing the configuration of the power line cable 3. FIG. 3(b) is a cross-sectional view of the power line cable 3 taken along line A-A in FIG. 3(a). The power line cable 3 includes a stranded body 30 formed by twisting a plurality of electric wires, a tape member 33 wound around the outer periphery of the stranded body 30, and a sheath 34 covering the outer periphery of the tape member 33. The stranded body 30 is formed by twisting a first electric wire group 31 and a second electric wire group 32, and an intervening member 300 made of a fibrous body such as staple fiber or Kevlar (registered trademark) is disposed at the center of the stranded body 30. The tape member 33 can be a strip made of, for example, non-woven fabric, paper, or resin. The sheath 34 is made of, for example, urethane resin.

[0020] Both the first electric wire group 31 and the second electric wire group 32 are redundantly connected to the electric motor 201. The first electric wire group 31 includes a first U-phase electric wire 311, a first V-phase electric wire 312, and a first W-phase electric wire 313. The second electric wire group 32 includes a second U-phase electric wire 321, a second V-phase electric wire 322, and a second W-phase electric wire 323. The first U-phase electric wire 311, the first V-phase electric wire 312, the first W-phase electric wire 313, the second U-phase electric wire 321, the second V-phase electric wire 322, and the second W-phase electric wire 323 are arranged side by side in the circumferential direction of the cable around the central axis C1 of the power line cable 3.

[0021] The first U-phase wire 311, the first V-phase wire 312, the first W-phase wire 313, the second U-phase wire 321, the second V-phase wire 322, and the second W-phase wire 323 each have a conductor 301 and an insulator 302 covering the conductor 301. The conductor 301 is, for example, a stranded wire made by twisting together a plurality of metal strands. Suitable metal strands include, for example, tin-plated copper wire, tin-plated copper alloy wire, silver-plated copper wire, or silver-plated copper alloy wire. The insulator 302 is made of an insulating resin material such as fluororesin. The conductor cross-sectional area and outer diameter of the first U-phase wire 311, the first V-phase wire 312, the first W-phase wire 313, the second U-phase wire 321, the second V-phase wire 322, and the second W-phase wire 323 are common. Furthermore, these wires can be distinguished during terminal processing by the different colors of their insulators 302.

[0022] In this embodiment, the first U-phase wire 311, the first V-phase wire 312, and the first W-phase wire 313 are adjacent to each other in the circumferential direction of the cable, and the second U-phase wire 321, the second V-phase wire 322, and the second W-phase wire 323 are adjacent to each other in the circumferential direction of the cable. More specifically, the first U-phase wire 311, the first V-phase wire 312, the first W-phase wire 313, the second U-phase wire 321, the second V-phase wire 322, and the second W-phase wire 323 are arranged in this order in the circumferential direction of the cable.

[0023] The switching circuit 22 can switch between supplying current to the electric motor 201 via the first wire group 31 or via the second wire group 32. In this embodiment, the first wire group 31 is designated as the primary system and the second wire group 32 as the backup system. When an abnormality occurs in the primary system, the first wire group 31, the circuit switches to the backup system, the second wire group 32, to supply three-phase alternating current to the electric motor 201. Alternatively, the first wire group 31 may be designated as the backup system and the second wire group 32 as the primary system.

[0024] The control device 24 determines that an abnormality such as a broken wire has occurred if, for example, the magnitude of the current flowing through any of the first U-phase wire 311, the first V-phase wire 312, and the first W-phase wire 313 is smaller than the current value expected according to the duty cycle of the PWM control, and controls the switching circuit 22 to switch to a state in which the backup system, the second wire group 32, supplies current to the electric motor 201. In addition, when the control device 24 controls the switching circuit 22 to switch to the backup system, it outputs a signal to notify the driver of the vehicle 1 of the occurrence of the abnormality.

[0025] (Effects of the first embodiment) According to the first embodiment described above, even if, for example, a break or partial break occurs in any of the first U-phase wire 311, first V-phase wire 312, and first W-phase wire 313 of the first wire group 31, current can still be supplied to the electric motor 201 by the second U-phase wire 321, second V-phase wire 322, and second W-phase wire 323 of the second wire group 32. This makes it possible to suppress situations in which the electric brake device 20 cannot be supplied with an appropriate current.

[0026] Furthermore, according to the first embodiment, the first U-phase wire 311, the first V-phase wire 312, and the first W-phase wire 313 of the first wire group 31, and the second U-phase wire 321, the second V-phase wire 322, and the second W-phase wire 323 of the second wire group 32 are all included in a single power cable 3. Therefore, compared to the case where each wire of the first wire group 31 and each wire of the second wire group 32 are each in separate cables, the wiring man-hours can be reduced.

[0027] Furthermore, according to the first embodiment, the first U-phase wire 311, the first V-phase wire 312, and the first W-phase wire 313 are adjacent to each other in the circumferential direction of the cable, and the second U-phase wire 321, the second V-phase wire 322, and the second W-phase wire 323 are adjacent to each other in the circumferential direction of the cable. Therefore, when terminating the power cable 3, it is easy to separate the first wire group 31 and the second wire group 32, making terminating easier.

[0028] Furthermore, according to the first embodiment, since the signal cables 41 and 42 are redundant, even if, for example, one of the signal cables 41 is being used as the primary system and a break or partial break occurs in the signal cable 41, the signal switching circuit 23 can be controlled to switch to the backup signal cable 42, thereby suppressing situations in which the electric brake device 20 cannot be properly controlled.

[0029] [Second Embodiment] Next, a second embodiment of the present invention will be described with reference to Figure 4. Figure 4 is a cross-sectional view of the power cable 3 according to the second embodiment. In this embodiment, similar to the first embodiment, the first U-phase wire 311, the first V-phase wire 312, the first W-phase wire 313, the second U-phase wire 321, the second V-phase wire 322, and the second W-phase wire 323 are arranged in the circumferential direction, but their order is different from that of the first embodiment.

[0030] In this embodiment, any of the first U-phase wires 311, first V-phase wires 312, and first W-phase wires 313 constituting the first wire group 31 and any of the second U-phase wires 321, second V-phase wires 322, and second W-phase wires 323 constituting the second wire group 32 are arranged alternately along the circumferential direction of the cable. More specifically, the first U-phase wire 311 is arranged between the second W-phase wire 323 and the second U-phase wire 321, the first V-phase wire 312 is arranged between the second U-phase wire 321 and the second V-phase wire 322, and the first W-phase wire 313 is arranged between the second V-phase wire 322 and the second W-phase wire 323.

[0031] The other configurations of the power cable 3 and the electric brake system 2 according to this embodiment are the same as in the first embodiment. A tape member 33 is wrapped around the outer circumference of a twisted body 30 formed by twisting together the first U-phase wire 311, the second U-phase wire 321, the first V-phase wire 312, the second V-phase wire 322, the first W-phase wire 313, and the second W-phase wire 323, and the outer circumference of the tape member 33 is covered with a sheath 34. In addition, one of the first wire group 31 and the second wire group 32 is used as the primary system, and the other is used as the backup system.

[0032] This embodiment, like the first embodiment, makes it possible to suppress the occurrence of situations where the electric brake device 20 cannot be supplied with an appropriate current. Furthermore, when the electric brake device 20 moves up and down with the wheels 10 relative to the vehicle body 11, it is possible to suppress the concentration of stress on one of the first wire group 31 and the second wire group 32. Moreover, since the backup wires (e.g., second U-phase wire 321, second V-phase wire 322, second W-phase wire 323) are interposed between the main wires (e.g., first U-phase wire 311, first V-phase wire 312, first W-phase wire 313), the distance between the wires through which current flows can be increased, suppressing temperature rise, enabling the flow of a larger current, or making it possible to reduce the conductor cross-sectional area and outer diameter of each wire.

[0033] [Third Embodiment] Next, a third embodiment of the present invention will be described with reference to Figure 5. Figure 5 is a cross-sectional view of the electric brake cable 5 according to the third embodiment. In the first embodiment, the power supply cable 3 that supplies current to the electric motor 201 and the signal cables 41 and 42 that transmit detection signals from each sensor were separate, but in the third embodiment, each wire of the power supply cable 3 and each wire of the signal cables 41 and 42 are combined into a single electric brake cable 5.

[0034] The electric brake cable 5 comprises a first three-phase AC cable 51, a second three-phase AC cable 52, multiple signal line cables 53-55, and one twisted pair cable 56, which are twisted together to form a twisted body 50. The first three-phase AC cable 51, the second three-phase AC cable 52, and the multiple signal line cables 53-55 are arranged in the circumferential direction of the cable with respect to the central axis C2 of the electric brake cable 5. The twisted pair cable 56 has a pair of signal lines 561 and is located in the valley between signal line cable 54 and signal line cable 55.

[0035] Furthermore, the electric brake cable 5 includes a tape member 57 wrapped around the outer circumference of the twisted body 50, a sheath 58 covering the outer circumference of the tape member 57, and an intervening 59 positioned around the twisted body 50. The materials of the tape member 57, the sheath 58, and the intervening 59 are the same as in the first embodiment.

[0036] The first three-phase AC cable 51 has a first wire group 510 consisting of a first U-phase wire 511, a first V-phase wire 512, and a first W-phase wire 513, and a first shield conductor 514, with the first U-phase wire 511, the first V-phase wire 512, and the first W-phase wire 513 being twisted together and covered by the first shield conductor 514. The second three-phase AC cable 52 has a second wire group 520 consisting of a second U-phase wire 521, a second V-phase wire 522, and a second W-phase wire 523, and a second shield conductor 524, with the second U-phase wire 521, the second V-phase wire 522, and the second W-phase wire 523 being twisted together and covered by the second shield conductor 524.

[0037] The first U-phase wire 511, the first V-phase wire 512, and the first W-phase wire 513, as well as the second U-phase wire 521, the second V-phase wire 522, and the second W-phase wire 523, all have a conductor 501 and an insulator 502 covering the conductor 501, similar to the first embodiment. The conductor 501 is, for example, a stranded wire made by twisting together a plurality of metal strands, and the insulator 502 is made of an insulating resin material such as fluororesin. The first shield conductor 514 and the second shield conductor 524 are, for example, braided shields made by braiding together a plurality of shield strands in a grid pattern.

[0038] Each signal cable 53 to 55 is constructed by twisting together multiple shielded twisted pair wires 6. In this embodiment, each signal cable 53 to 55 has three shielded twisted pair wires 6. Each shielded twisted pair wire 6 has a twisted pair of signal wires 61, 61 and a shield conductor 62 that covers the pair of signal wires 61, 61.

[0039] Each pair of signal lines 61, 61 has a signal line conductor 611 and an insulator 612 covering the signal line conductor 611. The signal line conductor 611 is, for example, a stranded wire made by twisting together a plurality of metal strands, and the insulator 612 is made of an insulating resin material such as fluororesin. The shield conductor 62 is, for example, a braided shield made by weaving together a plurality of shield strands in a grid pattern.

[0040] Hereinafter, signal cables 53 to 55 will be referred to as the first signal cable 53, the second signal cable 54, and the third signal cable 55, respectively. For example, the first signal cable 53 transmits the detection signal from the load sensor 204. The second signal cable 54 and the third signal cable 55 transmit the detection signal from the angle sensor 203. In addition, the twisted pair cable 56 transmits the detection signal from the temperature sensor 205.

[0041] The first signal cable 53 contains a total of six signal lines 61, of which half (3) are used as the primary system and the remaining three are used as the backup system. The second signal cable 54 and the third signal cable 55 contain a total of twelve signal lines 61, of which half (6) are used as the primary system and the remaining six are used as the backup system. In addition, in the twisted pair cable 56, one of the pair of signal lines 561 is used as the primary system and the other is used as the backup system. These signal lines are switched between the primary and backup systems by a signal line switching circuit, which is configured, for example, by a relay circuit, as in the first embodiment.

[0042] The first three-phase AC cable 51 and the second three-phase AC cable 52 are not adjacent in the circumferential direction of the cable. In Figure 5, the first three-phase AC cable 51 and the second three-phase AC cable 52 are shown side by side in the left-to-right direction of the drawing, with the first signal line cable 53 positioned on the upper side of the drawing between the first three-phase AC cable 51 and the second three-phase AC cable 52, and the second signal line cable 54 and the third signal line cable 55 positioned on the lower side of the drawing between the first three-phase AC cable 51 and the second three-phase AC cable 52. In other words, at least one of the first to third signal line cables 53 to 55 is interposed between the first three-phase AC cable 51 and the second three-phase AC cable 52.

[0043] The first wire group 510 of the first three-phase AC cable 51 and the second wire group 520 of the second three-phase AC cable 52 are both redundantly connected to the electric motor 201 of the electric brake device 20. Similar to the first embodiment, one is used as the primary system and the other as the backup system, and they are switched by a power line switching circuit, for example, which is composed of a relay circuit. For example, under normal circumstances, the first U-phase wire 511, the first V-phase wire 512, and the first W-phase wire 513 of the first wire group 510 supply three-phase AC current to the electric motor 201. When an abnormality occurs in the first wire group 510, the second U-phase wire 521, the second V-phase wire 522, and the second W-phase wire 523 of the second wire group 520 supply three-phase AC current to the electric motor 201. This makes it possible to suppress situations in which the electric brake device 20 cannot be supplied with the appropriate current, similar to the first embodiment.

[0044] Furthermore, in this embodiment, the first three-phase AC cable 51 is constructed by covering the first U-phase wire 511, the first V-phase wire 512, and the first W-phase wire 513 of the first wire group 510 together with the first shield conductor 514, and the second three-phase AC cable 52 is constructed by covering the second U-phase wire 521, the second V-phase wire 522, and the second W-phase wire 523 of the second wire group 520 together with the second shield conductor 524. As a result, the influence of radiated noise from the current supplied to the electric motor 201 on the first to third signal wire cables 53 to 55 outside the first shield conductor 514 and the second shield conductor 524 can be suppressed, and the first three-phase AC cable 51 and the second three-phase AC cable 52 can be easily separated when processing the terminals of the electric brake cable 5.

[0045] Furthermore, in this embodiment, since each pair of signal lines 61 of the first to third signal line cables 53 to 55 is covered by a shield conductor 63, crosstalk between multiple shielded twisted pair wires 6 is suppressed, and the effects of radiated noise from the current supplied to the electric motor 201 can be suppressed.

[0046] Furthermore, in this embodiment, a first three-phase AC cable 51 is arranged between the first signal cable 53 and the second signal cable 54 in the circumferential direction of the cable, and a second three-phase AC cable 52 is arranged between the first signal cable 53 and the third signal cable 55, thereby suppressing crosstalk between the first signal cable 53 and the second signal cable 54 and the third signal cable 55.

[0047] (Summary of the embodiments) Next, the technical concept understood from the first to third embodiments described above will be described using the reference numerals and other symbols from each embodiment. However, the reference numerals in the following description are not limited to the components in the claims that are specifically shown in the embodiments.

[0048] [1] An electric brake cable (3,5) that supplies three-phase alternating current to an electric motor (2) of an electric brake device (2) powered by an electric motor (201), comprising: a first group of wires (31,510) comprising a first U-phase wire (311,511), a first V-phase wire (312,512), and a first W-phase wire (313,513); and a second group of wires comprising a second U-phase wire (321,521), a second V-phase wire (322,522), and a second W-phase wire (323,523) An electric brake cable (3,5) comprising a group of wires (32,520), a tape member (33,57) wrapped around the outer circumference of a twisted body (30,50) formed by twisting the first group of wires (31,510) and the second group of wires (32,520), and a sheath (34,58) covering the outer circumference of the tape member (33,57), wherein both the first group of wires (31,510) and the second group of wires (32,520) are redundantly connected to the electric motor (201).

[0049] [2] The electric brake cable (3) according to [1] above, wherein the first U-phase wire (311), the first V-phase wire (312), the first W-phase wire (313), the second U-phase wire (321), the second V-phase wire (322), and the second W-phase wire (323) are arranged in the circumferential direction of the cable, the first U-phase wire (311), the first V-phase wire (312), and the first W-phase wire (313) are adjacent to each other in the circumferential direction of the cable, and the second U-phase wire (321), the second V-phase wire (322), and the second W-phase wire (323) are adjacent to each other in the circumferential direction of the cable.

[0050] [3] The electric brake cable (3) according to [1] above, wherein the first U-phase wire (311), the first V-phase wire (312), the first W-phase wire (313), the second U-phase wire (321), the second V-phase wire (322), and the second W-phase wire (323) are arranged in a line in the circumferential direction of the cable, and any of the first U-phase wire (311), the first V-phase wire (312), and the first W-phase wire (313) constituting the first wire group (31) and any of the second U-phase wire (321), the second V-phase wire (322), and the second W-phase wire (323) constituting the second wire group (32) are arranged alternately along the circumferential direction of the cable.

[0051] [4] The electric brake cable (5) according to [1] above, comprising: a first three-phase AC cable (51) in which the first U-phase wire (511), the first V-phase wire (512), and the first W-phase wire (513) are twisted together and covered with a first shield conductor (514); and a second three-phase AC cable (52) in which the second U-phase wire (521), the second V-phase wire (522), and the second W-phase wire (523) are twisted together and covered with a second shield conductor (524).

[0052] [5] The electric brake cable (5) described in [4] above, comprising the first three-phase AC cable (51), the second three-phase AC cable (52), and a plurality of signal lines (61), wherein the plurality of signal lines (61) are redundant.

[0053] [6] The electric brake cable (5) described in [5] above, wherein the plurality of signal lines (61) are twisted together to form a signal line cable (53-55), and the signal line cables (53-55), the first three-phase AC cable (51), and the second three-phase AC cable (52) are twisted together to form the twisted body (50).

[0054] [7] The electric brake cable (5) according to [6] above, wherein a plurality of signal line cables (53-55), the first three-phase AC cable (51), and the second three-phase AC cable (52) are arranged in the circumferential direction of the cable, and at least one of the signal line cables (53-55) is interposed between the first three-phase AC cable (51) and the second three-phase AC cable (52) in the circumferential direction of the cable.

[0055] Although embodiments of the present invention have been described above, the embodiments described above do not limit the invention as defined in the claims. Furthermore, it should be noted that not all combinations of features described in the embodiments are necessarily essential for solving the problem of the invention. [Explanation of symbols]

[0056] 2…Electric braking system 20…Electric braking device 201…Electric motor 22…Switching circuit 3... Power cable (cable for electric brakes) 30... Stranded bundle 31...1st wire group 311...1st U phase wire 312...First V-phase wire 313...First W-phase wire 32...2nd wire group 321...2nd U phase wire 322...2nd V phase wire 323...2nd W phase wire 33...Tape material 34...Sheath 5…Cable for electric brakes 50…Twisted joint 51...First three-phase AC cable 510...First group of wires 511...1st U phase wire 512...1st V phase wire 513...First W-phase wire 514...First shield conductor 52...Second three-phase AC cable 520...Second group of electric wires 521...2nd U phase wire 522...2nd V phase wire 523...Second W-phase wire 524...Second shield conductor 53-55... Signal cable 57... Tape material 58...Sheath 61...Signal wire

Claims

1. An electric brake cable that supplies a three-phase alternating current to the electric motor of an electric brake system that uses an electric motor as a power source, A first group of wires comprising a first U-phase wire, a first V-phase wire, and a first W-phase wire, A second group of wires comprising a second U-phase wire, a second V-phase wire, and a second W-phase wire, A tape member wrapped around the outer circumference of a twisted body formed by twisting together the first group of electric wires and the second group of electric wires, The tape member comprises a sheath that covers the outer circumference of the tape member, Both the first group of wires and the second group of wires are redundantly connected to the electric motor. Cable for electric brakes.

2. The first U-phase wire, the first V-phase wire, the first W-phase wire, the second U-phase wire, the second V-phase wire, and the second W-phase wire are arranged in a line in the circumferential direction of the cable. The first U-phase wire, the first V-phase wire, and the first W-phase wire are adjacent to each other in the circumferential direction of the cable. The second U-phase wire, the second V-phase wire, and the second W-phase wire are adjacent to each other in the circumferential direction of the cable. The electric brake cable according to claim 1.

3. The first U-phase wire, the first V-phase wire, the first W-phase wire, the second U-phase wire, the second V-phase wire, and the second W-phase wire are arranged in a line in the circumferential direction of the cable. The first U-phase wire, the first V-phase wire, and the first W-phase wire constituting the first wire group, and the second U-phase wire, the second V-phase wire, and the second W-phase wire constituting the second wire group, are arranged alternately along the circumferential direction of the cable. The electric brake cable according to claim 1.

4. A first three-phase AC cable in which the first U-phase wire, the first V-phase wire, and the first W-phase wire are twisted together and covered with a first shield conductor, The invention comprises a second three-phase AC cable in which the second U-phase wire, the second V-phase wire, and the second W-phase wire are twisted together and covered with a second shield conductor, The electric brake cable according to claim 1.

5. The twisted body comprises the first three-phase AC cable, the second three-phase AC cable, and a plurality of signal lines. The aforementioned multiple signal lines are made redundant. The electric brake cable according to claim 4.

6. The aforementioned multiple signal lines are twisted together to form a signal cable. The signal cable, the first three-phase AC cable, and the second three-phase AC cable are twisted together to form the twisted body. The electric brake cable according to claim 5.

7. Multiple signal line cables, the first three-phase AC cable, and the second three-phase AC cable are arranged in a line in the circumferential direction of the cable. In the circumferential direction of the cable, at least one signal line cable is interposed between the first three-phase AC cable and the second three-phase AC cable. The electric brake cable according to claim 6.

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