cable

Abstract

To provide a cable in which terminal processability is improved while maintaining durability to twisting.SOLUTION: A cable 1 comprises: a pair of first electric wires 2; a multicore wire 8 having a twisted-pair wire 4 formed by stranding a pair of second electric wires 3; and a tape member 6 which is spirally wound around a stranded body 5 formed by stranding the pair of first electric wires 2 and the multicore wire 8, where the first electric wires 2 contact with each other, and each of the first electric wires 2 and the multicore wire 8 contact with each other, a stranding direction of the stranded body 5 and a winding direction of the tape member 6 are the same direction. The cable also comprises: a linear first intervention 91 which is provided in a valley part between the first electric wires 2 adjacent in a cable circumferential direction; and a pair of linear second interventions 92 which are provided in a valley part between the multicore wire 8 and one and the other first electric wires 2 adjacent in a cable circumferential direction, where the tape member 6 contacts all of the first electric wires 2 and the multicore wire 8 and the first intervention 91 and second interventions 92 which constitute the stranded body 5.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a cable.

Background Art

[0002] In recent years, in vehicles such as automobiles, electric braking devices have been used. As electric braking devices, an electro-mechanical brake (EMB) and an electric parking brake (EPB) are known. In addition, in recent vehicles, sensors such as an ABS (Anti-lock Brake System) sensor that detects the rotational speed of a wheel during traveling, a pneumatic pressure sensor that detects the pneumatic pressure of a tire, and a temperature sensor are often mounted on the wheels.

[0003] Therefore, a cable in which signal lines for sensors mounted on the wheels and signal lines for controlling an electro-mechanical brake, and a power supply line for supplying power to an electric motor for an electro-mechanical brake or an electric parking brake are housed in a common sheath is used to connect the wheel side and the vehicle body side.

[0004] In Patent Document 1, a tape member is spirally wound around a twisted body obtained by twisting a pair of first electric wires for power transmission and a twisted pair of second electric wires for signal transmission, and a sheath is provided around it. In this Patent Document 1, by setting the twisting direction of the twisted pair, the twisting direction of the twisted body, and the winding direction of the tape member to the same direction, it is easy to untwist the electric wires to improve the terminal processing property, and the durability against twisting is improved.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, if the twisting direction of the stranded wires, the twisting direction of the twisted body, and the winding direction of the tape material are all the same, the tape material and sheath tend to get stuck in the gaps (valleys) between adjacent wires. Because these stuck parts are difficult to cut with tools, it becomes difficult to remove the sheath and tape material, which can sometimes worsen the processability of the terminals.

[0007] Therefore, the present invention aims to provide a cable that improves terminal processability while maintaining durability against twisting. [Means for solving the problem]

[0008] The present invention aims to solve the above problems and provides a cable comprising: a multi-core wire having a pair of first wires and a pair of twisted wires formed by twisting together a pair of second wires having a smaller outer diameter than the first wires; a tape member spirally wound around a twisted body formed by twisting together the pair of first wires and the multi-core wire; and an outer sheath covering the outer circumference of the tape member, wherein the pair of first wires are in contact with each other, and each of the first wires is in contact with the multi-core wire, the twisting direction of the twisted body and the winding direction of the tape member are in the same direction, and a linear first intervening provided in the valley portion between adjacent first wires in the circumferential direction of the cable, and a pair of linear second intervenings provided in the valley portion between adjacent multi-core wires in the circumferential direction of the cable and one and the other first wires, respectively, wherein the tape member is in contact with all of the first wires and second wires and the first and second intervenings that constitute the twisted body. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a cable that improves terminal processability while maintaining durability against twisting. [Brief explanation of the drawing]

[0010] [Figure 1] This is a block diagram showing the configuration of a vehicle using a cable according to one embodiment of the present invention. [Figure 2] This is a cross-sectional view showing a section perpendicular to the longitudinal direction of a cable according to one embodiment of the present invention. [Figure 3] This is a cross-sectional view showing a cross-section perpendicular to the longitudinal direction of a cable according to one modified example of the present invention. [Figure 4] This is a cross-sectional view showing a cross-section perpendicular to the longitudinal direction of a cable according to one modified example of the present invention. [Modes for carrying out the invention]

[0011] [Embodiment] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0012] Figure 1 is a block diagram showing the configuration of a vehicle 100 using the cable 1 according to this embodiment. As shown in Figure 1, the vehicle 100 is equipped with an electric parking brake (hereinafter referred to as EPB) 101 as an electric braking device.

[0013] The EPB101 comprises an electric motor 101a for the EPB and an EPB control unit 101b. The electric motor 101a for the EPB is mounted on the wheel 102 of the vehicle 100. The EPB control unit 101b is mounted on the ECU (electronic control unit) 103 of the vehicle 100. The EPB control unit 101b may also be mounted on a control unit other than the ECU 103, or on a dedicated hardware unit.

[0014] Although not shown in the diagram, the electric motor 101a for the EPB is equipped with a piston to which a brake pad is attached. By moving this piston through the rotational drive of the electric motor 101a for the EPB, the brake pad is pressed against the disc rotor of the wheel 102, thereby generating braking force. A pair of first wires 2 are connected to the electric motor 101a for the EPB as power lines to supply drive current to the electric motor 101a for the EPB.

[0015] The EPB control unit 101b is configured to output a drive current to the EPB electric motor 101a for a predetermined time (e.g., 1 second) when the parking brake activation switch 101c is operated from the off state to the on state while the vehicle 100 is stopped, thereby pressing the brake pads against the disc rotor of the wheel 102 and generating braking force on the wheel 102. The EPB control unit 101b is also configured to output a drive current to the EPB electric motor 101a when the parking brake activation switch 101c is operated from the on state to the off state, or when the accelerator pedal is pressed, thereby separating the brake pads from the disc rotor of the wheel 102 and releasing the braking force on the wheel 102. In other words, the operating state of the EPB 101 is configured to be maintained from the time the parking brake activation switch 101c is turned on until the parking brake activation switch 101c is turned off or the accelerator pedal is pressed. The parking brake activation switch 101c may be a lever type or a pedal type switch.

[0016] Furthermore, the vehicle 100 is equipped with an ABS system 104. The ABS system 104 comprises an ABS sensor 104a and an ABS control unit 104b.

[0017] The ABS sensor 104a detects the rotational speed of the wheel 102 while driving and is mounted on the wheel 102. The ABS control unit 104b controls the braking system based on the output of the ABS sensor 104a to control the braking force of the wheel 102, so that the wheel 102 does not lock up during sudden braking, and is mounted on the ECU 103. A pair of second wires 3 are connected to the ABS sensor 104a as signal lines.

[0018] The cable 1 according to the present embodiment is one in which the first electric wire 2 and the second electric wire 3 are collectively covered with an outer sheath 7 (see FIG. 2). The cable 1 extending from the wheel 102 side is connected to an electric wire group 107 in a relay box 106 provided in the vehicle body 105, and is connected to an ECU 103 and a battery (not shown) via the electric wire group 107.

[0019] In FIG. 1, only one wheel 102 is shown for simplification of the drawing, but the EPB electric motor 101a and the ABS sensor 104a may be mounted on each wheel 102 of the vehicle 100. For example, they may be mounted only on the front wheels or only on the rear wheels of the vehicle 100.

[0020] (Cable 1) FIG. 2 is a cross-sectional view showing a cross-section perpendicular to the longitudinal direction of the cable 1 according to the present embodiment. As shown in FIG. 2, the cable 1 includes a stranded wire 8 having a pair of first electric wires 2 and a pair of second electric wires 3 having an outer diameter smaller than that of the first electric wires 2 twisted together, and a tape member 6 spirally wound around a twisted body 5 formed by twisting the pair of first electric wires 2 and the stranded wire 4, and an outer sheath 7 provided so as to cover the periphery of the tape member 6.

[0021] In the present embodiment, the first electric wire 2 is composed of a power supply line (that is, an electric wire for power transmission) for supplying a drive current to the EPB electric motor 101a mounted on the wheel 102 of the vehicle 100. The second electric wire 3 is composed of a signal line (that is, an electric wire for signal transmission) for the ABS sensor 104a mounted on the wheel 102.

[0022] (First electric wire 2) The first electric wire 2 is configured by covering a first conductor 21 formed by twisting together fine wires of good conductivity such as copper with a first insulator 22 made of an insulating resin composition such as cross-linked polyethylene.

[0023] The strands used for the first conductor 21 may have a diameter of 0.05 mm or more and 0.30 mm or less. If strands with a diameter of less than 0.05 mm are used, sufficient mechanical strength may not be obtained, and the bending resistance may decrease. If strands with a diameter greater than 0.30 mm are used, the flexibility of the cable 1 may decrease.

[0024] The outer diameter of the first conductor 21 and the thickness of the first insulator 22 of the first wire 2 can be appropriately set according to the required drive current. In this embodiment, considering that the first wire 2 is a power supply line for supplying drive current to the electric motor 101a for the EPB, the outer diameter of the first conductor 21 is set to 1.5 mm or more and 3.0 mm or less, and the outer diameter of the first wire 2 is set to 2.0 mm or more and 4.0 mm or less.

[0025] (Multi-core wire 8) The second electric wire 3 is constructed by covering a second conductor 31, which is made by twisting together highly conductive strands such as copper, with a second insulator 32 made of an insulating resin composition such as cross-linked polyethylene. The strands used for the second conductor 31 can have a diameter of 0.05 mm or more and 0.30 mm or less, similar to the first conductor 21.

[0026] The twist pitch of the stranded wires 4 should be set to a degree that does not place unnecessary load on the second wire 3, taking into consideration the outer diameter of the second wire 3. Here, the twist pitch of the stranded wires 4 is set to approximately 30 mm, but the twist pitch of the stranded wires 4 is not limited to this. The twist pitch of the stranded wires 4 is the distance along the longitudinal direction of the stranded wires 4 at which any two second wires 3 are in the same position in the circumferential direction of the stranded wires 4.

[0027] The multi-core wire 8 is constructed by covering the twisted pair wires 4 with an internal sheath 81. The internal sheath 81 is made of, for example, urethane resin. In this embodiment, the outer diameter of the multi-core wire 8 is larger than the outer diameter of the first electric wire 2.

[0028] (twist union 5) The twisted body 5 is constructed by twisting together a pair of first electric wires 2 and a multi-core wire 8. In this embodiment, the pair of first electric wires 2 are in contact with each other, and each of the first electric wires 2 is in contact with the multi-core wire 8. At this time, at least a portion of the multi-core wire 8 is placed in the valley portion between the pair of first electric wires 2.

[0029] In this embodiment, in addition to a pair of first electric wires 2 and a multi-core wire 8, three linear intervening elements 9 are also twisted together to form a twisted body 5. Therefore, the twisting direction and twisting pitch of the intervening elements 9 are the same as the twisting direction and twisting pitch of the twisted body 5. Details of the intervening elements 9 will be described later.

[0030] Incidentally, the EPB101 basically supplies drive current to the EPB electric motor 101a when the vehicle 100 is stopped. In contrast, the ABS sensor 104a is used when the vehicle 100 is running, and the ABS sensor 104a is not used when drive current is supplied to the first wire 2. Therefore, in this embodiment, the shield conductor provided around the twisted pair wire 4 (multi-core wire 8) is omitted. By omitting the shield conductor, the outer diameter of the cable 1 can be made smaller compared to when a shield conductor is provided, and the number of parts can be reduced, thereby suppressing costs.

[0031] In this explanation, the first wire 2 is described as supplying drive current to the electric motor 101a for the EPB. However, the first wire 2 may also be used to supply drive current to the electric motor of an electromechanical brake (hereinafter referred to as EMB) provided on the wheel 102, for example. In this case, current will flow through the first wire 2 even while the vehicle 100 is in motion, so it is desirable to provide a shield conductor around the twisted wire 4 (multi-core wire 8) to suppress malfunctions of the ABS device 104 due to noise.

[0032] Furthermore, although this explanation describes the case where the second wire 3 is a signal wire for the ABS sensor 104a, the second wire 3 may also be a signal wire used for other sensors installed on the wheel 102, such as a temperature sensor or an air pressure sensor for detecting tire pressure, or it may be a damper wire used to control the vibration damping device of the vehicle 100, or it may even be a signal wire for EMB control (CAN cable, etc.). Even if the first wire 2 supplies drive current to the EPB electric motor 101a, if the second wire 3 is used while the vehicle 100 is stopped, it is desirable to provide a shield conductor around the twisted pair wire 4 (multi-core wire 8) to suppress malfunctions due to noise.

[0033] The overall outer diameter of the twisted body 5 is, for example, about 5 mm to 9 mm. The twist pitch of the twisted body 5 should be set considering the outer diameter of the twisted body 5, so as not to place unnecessary load on the first electric wire 2 and the paired strands 4. Here, the twist pitch of the twisted body 5 is set to approximately 60 mm, but the twist pitch of the twisted body 5 is not limited to this. The twist pitch of the twisted body 5 is the interval along the longitudinal direction of the twisted body 5 at which any first electric wire 2 or multi-core wire 8 is in the same position in the circumferential direction of the twisted body 5.

[0034] (Tape member 6) A tape member 6 is spirally wrapped around the twisted body 5. The tape member 6 is in contact with all of the first electric wires 2 and multi-core wires 8 and the intervening 9 (first intervening 91 and second intervening 92, described later) that make up the twisted body 5. The tape member 6 is interposed between the twisted body 5 and the outer sheath 7 and plays a role in reducing friction between the twisted body 5 and the outer sheath 7 when bent. In other words, by providing the tape member 6, it is possible to reduce friction between the first electric wires 2 and multi-core wires 8 and the outer sheath 7 without using lubricants such as talc powder as in the conventional method, thereby reducing the stress on the first electric wires 2 and multi-core wires 8 when bent and improving bending resistance.

[0035] As the tape member 6, it is desirable to use a material that is slippery (has a low coefficient of friction) with respect to the first insulator 22 and the internal sheath 81 of the first electric wire 2. More specifically, as the tape member 6, it is preferable to use a material in which the coefficient of friction (static friction coefficient) between the tape member 6 and the first insulator 22 and the internal sheath 81 is smaller than the coefficient of friction (static friction coefficient) between the external sheath 7 and the first insulator 22 and the internal sheath 81 when the tape member 6 is not provided.

[0036] In this embodiment, the tape member 6 is made of a nonwoven fabric formed by mixing a first fiber having a melting point higher than the extrusion molding temperature of the outer sheath 7 and a second fiber having a melting point lower than the extrusion molding temperature of the outer sheath 7. More specifically, the tape member 6 is made of a nonwoven fabric formed by mixing high-melting-point PET (polyethylene terephthalate) fibers as the first fiber and low-melting-point PET (polyethylene terephthalate) fibers as the second fiber in a predetermined ratio.

[0037] The melting point of low-melting-point PET fibers is lower than that of high-melting-point PET fibers. Furthermore, the melting point of low-melting-point PET fibers is lower than the extrusion molding temperature of the outer sheath 7. Conversely, the melting point of high-melting-point PET fibers is higher than the extrusion molding temperature of the outer sheath 7. The extrusion molding temperature of the outer sheath 7 refers to the temperature at which the outer sheath 7 is coated around the tape member 6 by extrusion molding. For example, when using PET with a melting point of approximately 250 degrees as the high-melting-point PET fiber and urethane resin with an extrusion molding temperature of approximately 230 degrees as the outer sheath 7, it is preferable to use PET fibers with a melting point of approximately 220 degrees as the low-melting-point PET fiber.

[0038] By including low-melting-point PET fibers in the material of the tape member 6, when the outer sheath 7 is coated onto the tape member 6 by extrusion molding, the low-melting-point PET fibers, which are a component of the tape member 6, soften or melt at the temperature during extrusion molding and adhere to the inner surface of the outer sheath 7. Therefore, the tape member 6 can be integrated with the outer sheath 7 without applying an adhesive to the tape member 6 separately. However, if the content of low-melting-point PET fibers is too high, the bond between the tape member 6 and the outer sheath 7 may become too strong, potentially reducing the flexibility of the cable 1. Therefore, the tape member 6 should be a mixture of low-melting-point PET fibers and high-melting-point PET fibers.

[0039] The content of low-melting-point PET fibers (total mass of low-melting-point PET fibers in the tape member 6 / mass of the tape member 6) should preferably be 10% by mass or more and 90% by mass or less. If the content of low-melting-point PET fibers is less than 10% by mass, the tape member 6 may not adhere well to the inner surface of the outer sheath 7, and if the content of low-melting-point PET fibers is greater than 90% by mass, the flexibility of the cable 1 may decrease. Furthermore, from the viewpoint of further suppressing these risks, it is more preferable that the content of low-melting-point PET fibers be 20% by mass or more and 80% by mass or less. In addition, in order to suppress fraying when removing the tape member 6, the length of the high-melting-point PET fibers and low-melting-point PET fibers should preferably be 5 mm or less.

[0040] Furthermore, the second low-melting-point fiber is not limited to low-melting-point PET fiber; any other fiber that softens or melts at the extrusion temperature of the outer sheath 7 and adheres to the inner surface of the outer sheath 7 is acceptable. In this embodiment, the tape member 6 only needs to contain two types of fibers with different melting points, and may be formed by mixing three or more types of fibers.

[0041] The tape member 6 is wound around the twisted body 5 in a spiral shape such that a portion of its width (the direction perpendicular to the longitudinal and thickness directions of the tape member 6) overlaps. The overlapping width of the tape member 6 is, for example, between 1 / 4 and 1 / 2 of the width of the tape member 6. The width of the tape member 6 should be such that it does not wrinkle when wound around the body, and it is preferable to use a narrower tape member 6 as the overall outer diameter of the twisted body 5 decreases. Specifically, if the outer diameter of the twisted body 5 is 5 mm to 9 mm, the width of the tape member 6 should be about 20 mm to 50 mm.

[0042] The winding pitch of the tape member 6, that is, the interval along the longitudinal direction where the tape member 6 is at the same position in the circumferential direction (for example, the interval between one end in the width direction), depends on the width and overlap width (winding angle of the tape member 6), and in this case, it is up to about 40 mm. Here, the winding pitch of the tape member 6 is set to about 30 mm, but the winding pitch of the tape member 6 is not limited to this. Note that if the width of the tape member 6 is increased and the winding pitch is increased, it will be closer to a state where the tape member 6 is attached vertically, and the flexibility of the cable 1 will be lost and it will become difficult to bend. For this reason, it is desirable to keep the winding pitch of the tape member 6 to 40 mm or less.

[0043] (External sheath 7) An outer sheath 7 is provided around the tape member 6. The outer sheath 7 is made of, for example, urethane resin. In this embodiment, the first electric wire 2 supplies drive current to the electric motor 101a for the EPB, and since the time during which the drive current flows through the first electric wire 2 is relatively short, the shield conductor provided around the tape member 6 is omitted. However, depending on the application of the first electric wire 2, a shield conductor may be provided between the tape member 6 and the outer sheath 7, or on the outer circumference of the outer sheath 7.

[0044] (Twisting direction of twisted body 5, winding direction of tape member 6) In the cable 1 according to this embodiment, the twisting direction of the paired wires 4, the twisting direction of the twisted body 5, and the winding direction of the tape member 6 are all in the same direction. The twisting direction here refers to the direction in which the first electric wire 2 and the multi-core wire 8 rotate from the other end to the first end when viewed from one end of the cable 1 (the side where the overlap of the tape member 6 is on top). The twisting direction of the paired wires 4 refers to the direction in which the two second electric wires 3 are twisted together, and the twisting direction of the twisted body 5 refers to the direction in which the first electric wire 2, the multi-core wire 8, and the intervening 9 are twisted together. The winding direction of the tape member 6 refers to the direction in which the tape member 6 rotates from the other end to the first end when viewed from one end of the cable 1 (the side where the overlap of the tape member 6 is on top). In Figure 2, the twisting direction of the paired strands 4 is indicated by the dashed arrow A, the twisting direction of the twisted body 5 is indicated by the dashed arrow B, and the winding direction of the tape member 6 is indicated by the dashed arrow C.

[0045] By making the twisting direction of the twisted body 5 and the winding direction of the tape member 6 the same, when twisting is applied to the cable 1, the twisted body 5 and the tape member 6 will open and close in sync, thereby improving durability against twisting.

[0046] In this regard, for example, if the twisting direction of the twisted body 5 and the winding direction of the tape member 6 are opposite, when twisting is applied to the cable 1 in a direction that causes the twisted body 5 to open (the diameter of the twisted body 5 to increase), the tape member 6 will close instead (the diameter of the tape member 6 will decrease) because the twisting direction of the twisted body 5 and the winding direction of the tape member 6 are opposite. At this time, the tape member 6 holds down the twisted body 5 as it tries to open, putting stress on the twisted body 5 and placing an excessive load on a portion of the pair of first electric wires 2 or multi-core wires 8. Therefore, in this embodiment, the twisting direction of the twisted body 5 and the winding direction of the tape member 6 are set to the same direction, so that when twisting is applied to the cable 1, the twisted body 5 and the tape member 6 open and close in sync. This makes it possible to improve the durability of the cable 1 against twisting.

[0047] Reducing the twist pitch of the twisted body 5 makes the cable 1 easier to bend and improves its flexibility, but it reduces the slack in the twist and decreases its resistance to twisting. Conversely, increasing the twist pitch of the twisted body 5 improves its resistance to twisting but reduces its flexibility. In this embodiment, when twisting is applied to the cable 1, the twisted body 5 and the tape member 6 open and close in sync to distribute the load, so even when the twist pitch of the twisted body 5 is reduced to improve flexibility, it is possible to ensure sufficient resistance to twisting.

[0048] Furthermore, if the twist pitch of the twisted body 5 and the winding pitch of the tape member 6 are the same, the tape member 6 and the outer sheath 7 will easily get caught between the electric wires (first electric wire 2 and multi-core wire 8). As will be described in detail later, in this embodiment, the inward intrusion of the tape member 6 and the outer sheath 7 is suppressed by providing an intervening 9, but in order to further suppress the inward intrusion of the tape member 6 and the outer sheath 7, it is desirable to make the twist pitch of the twisted body 5 different from the winding pitch of the tape member 6 (specifically, to make it 10% to 80% smaller than the twist pitch of the twisted body 5).

[0049] (Intervention 9) As described above, if the twisting direction of the twisted body 5 and the winding direction of the tape member 6 are the same, the durability against twisting can be improved. However, if the twisting direction of the twisted body 5 and the winding direction of the tape member 6 are the same, the pressure when the outer sheath 7 is covered on the outer circumference of the tape member 6 makes it easy for the tape member 6 and the outer sheath 7 to get stuck between the first electric wires 2 or between the first electric wires 2 and the multi-core wires 8. When the tape member 6 and the outer sheath 7 get stuck between the first electric wires 2 or between the first electric wires 2 and the multi-core wires 8, the stuck portion becomes difficult to cut with a tool, making it difficult to remove the tape member 6 and the outer sheath 7 and reducing the processability of the terminal. In addition, the cross-sectional shape of the twisted body 5 may become irregular, degrading its appearance, or the twisted body 5 may become less slippery inside the tape member 6, reducing its flexibility.

[0050] Therefore, in this embodiment, by providing one intervening member 9 in each of the valleys between adjacent electric wires (first electric wire 2 and multi-core wire 8) in the circumferential direction of the cable, the tape member 6 and the outer sheath 7 are prevented from entering the valleys between the electric wires (first electric wire 2 and multi-core wire 8). This suppresses a decrease in terminal workability and prevents deterioration of appearance and a decrease in flexibility.

[0051] More specifically, the intervening 9 includes a linear first intervening 91 provided in the valley between the first electric wires 2, and a pair of linear second intervenings 92 provided in the valley between adjacent multi-core wires 8 in the circumferential direction of the cable and the first electric wires 2 on one side and the other side. The first intervening 91 and the second intervening 92 have a circular cross-section perpendicular to the longitudinal direction, and are bundled and twisted together with the pair of first electric wires 2 and multi-core wires 8 to form a twisted body 5. The tape member 6 wrapped around the twisted body 5 is in contact with all of the first electric wires 2 and multi-core wires 8 and the first intervening 91 and the second intervening 92 that constitute the twisted body 5.

[0052] The outer diameters of the first intervening 91 and the second intervening 92 are determined according to the outer diameters of the first electric wire 2 and the multi-core wire 8. In this embodiment, the outer diameters of the pair of second intervening 92s are the same, while the outer diameter of the first intervening 91 is different from the outer diameter of the pair of second intervening 92s. If the outer diameter of the multi-core wire 8 is larger than the outer diameter of the first electric wire 2, the outer diameter of the first intervening 91 should be smaller than the outer diameter of the second intervening 92. Conversely, if the outer diameter of the multi-core wire 8 is smaller than the outer diameter of the first electric wire 2, the outer diameter of the first intervening 91 should be larger than the outer diameter of the second intervening 92 (see Figure 3). More preferably, when considering the circumscribed circles of a pair of first wires 2 and multi-core wires 8 in a cross-sectional view perpendicular to the longitudinal direction of the cable, the outer diameters of the first intervening 91 and the second intervening 92 should be determined so that they are in contact with these circumscribed circles and with the outer surfaces of two adjacent wires (first wires 2 and multi-core wires 8) that form the valley portion where the intervening 9 is placed. This makes the inner surface of the tape member 6 more circular in a cross-sectional view perpendicular to the longitudinal direction of the cable, making it easier to remove the tape member 6 and the outer sheath 7 with tools or the like.

[0053] It is desirable that the first intervening 91 and the second intervening 92 be made of a material that does not soften due to the heat generated when the outer sheath 7 is extruded. This is because if the first intervening 91 and the second intervening 92 soften due to the heat generated when the outer sheath 7 is extruded, they will stick to the surrounding tape member 6, the first electric wire 2, and the multi-core wire 8, reducing the processability of the terminals and hindering the movement of the twisted body 5 relative to the tape member 6 when the cable 1 is bent, making it difficult to bend. In this embodiment, when a tape member 6 containing a second fiber with a low melting point is used, sticking between the tape member 6 and the intervening 9 may occur in particular.

[0054] As the first intervening 91 and the second intervening 92, high-melting-point resin compositions such as fluororesins or crosslinked resin compositions can be used. Since high-melting-point resin compositions such as fluororesins are relatively expensive, it is more preferable to use crosslinked resin compositions. As the crosslinked resin composition, inexpensive crosslinked polyethylene can be used. Polyethylene before crosslinking has a low melting point and melts due to the heat generated when the outer sheath 7 is extruded, but crosslinking suppresses softening due to the heat generated when the outer sheath 7 is extruded. In this way, by using crosslinked resin compositions as the first intervening 91 and the second intervening 92, it becomes possible to use resin compositions with a melting point lower than the extrusion temperature of the outer sheath 7 before crosslinking, thereby reducing costs. Furthermore, by using crosslinked resin compositions as the first intervening 91 and the second intervening 92, even if a tape member 6 containing a second low-melting-point fiber is used, the occurrence of sticking between the tape member 6 and the intervening 9 can be suppressed.

[0055] Furthermore, by roughening the surfaces of the first intervening 91 and the second intervening 92, friction with surrounding members (tape member 6, first electric wire 2, and multi-core wire 8) can be suppressed, thereby improving flexibility. In this case, the arithmetic mean roughness Ra of the surfaces of the first intervening 91 and the second intervening 92 is preferably 1 μm or more and 30 μm or less, and more preferably 4 μm or more and 15 μm or less.

[0056] (modified version) In this embodiment, a multi-core wire 8 is used in which an internal sheath 81 is provided around the paired strands 4. However, the invention is not limited to this, and the internal sheath 81 may be omitted, as shown in cable 1a in Figure 3. In this case, the multi-core wire 8 will consist only of the paired strands 4.

[0057] When the internal sheath 81 is omitted and the stranded wires 4 are used as is, as in cable 1a, it is desirable that the twisting direction of the stranded wires 4, the twisting direction of the twisted body 5, and the winding direction of the tape member 6 be in the same direction.

[0058] By making the twisting direction of the paired wires 4 and the twisting direction of the twisted body 5 the same, when twisting the twisted body 5, the paired wires 4 and the first wires 2 are twisted together in a direction that follows the bending tendency imparted to the paired wires 4 by twisting the two second wires 3. As a result, when the cable 1 bends, the pair of first wires 2 and the paired wires 4 expand and contract in sync in the longitudinal direction of the cable 1, making the cable 1 more flexible and improving its flexibility.

[0059] Furthermore, in cable 1a, the twisted body 5 is formed by twisting the stranded wires 4 in a direction that follows their natural bending tendency. Therefore, when the outer sheath 7 and tape member 6 are removed simultaneously with a tool such as a stripping device, the first wire 2 and the stranded wires 4 tend to remain twisted due to the natural bending tendency of the stranded wires 4. When the length of the outer sheath 7 to be removed during terminal processing is increased, the stripping operation is performed in multiple steps. However, in cable 1, the first wire 2 and the stranded wires 4 remain twisted even after the stripping operation has been performed once, making it easy to perform multiple stripping operations.

[0060] In cable 1a, the twist direction of the paired wires 4 and the twist direction of the twisted body 5 are the same. Therefore, if the twist pitch of the paired wires 4 and the twist pitch of the twisted body 5 are the same, the positional relationship between the first wire 2 and the second wire 3 will always be the same in the longitudinal direction, which may cause the appearance of cable 1 to become distorted. For this reason, it is desirable to make the twist pitch of the paired wires 4 different from the twist pitch of the twisted body 5 (specifically, to make it 10% to 80% smaller than the twist pitch of the twisted body 5). If the twist pitch of the paired wires 4 is larger than the twist pitch of the twisted body 5, the twist pitch of the paired wires 4 may fluctuate when the twisted bodies 5 are twisted together. Therefore, it is desirable that the twist pitch of the paired wires 4 be at least smaller than the twist pitch of the twisted body 5.

[0061] Furthermore, as shown in Figure 4 for cable 1b, additional intervening 9 may be provided in the valleys between the intervening 9 and the wires adjacent to it in the circumferential direction (first wire 2 or multi-core wire 8). Cable 1b shows the case where a third intervening 93 is provided in each of the valleys between a pair of second intervening 92 and the multi-core wire 8. Although not shown, additional intervening 9 may be provided in the valleys between the second intervening 92 and the first wire 2, or between the first intervening 91 and the first wire 2.

[0062] Furthermore, although this embodiment describes a case where the intervening 9 is made of a resin composition, it is not limited to this, and at least one of the intervening 9 may be a wire break detection wire for detecting a break in the cable 1. The wire break detection wire is constructed by covering a stranded conductor with an insulator, and it is desirable that the insulator be made of a crosslinked resin composition (for example, crosslinked polyethylene) or a high-melting-point resin composition such as fluororesin, so that it does not stick to the surroundings due to the heat generated during the extrusion molding of the outer sheath 7. Note that the wire break detection wire is not used for signal transmission or power transmission, and is therefore not included in the first wire 2 or the second wire 3.

[0063] Furthermore, although this embodiment describes a case where a nonwoven fabric formed by mixing two types of fibers with different melting points is used as the tape member 6, the tape member 6 is not limited to this, and may be a nonwoven fabric formed from one type of fiber, or it may be made of paper, resin film, or the like.

[0064] (Operation and Effects of the Embodiment) As described above, in the cable 1 according to this embodiment, the twisting direction of the twisted body 5 and the winding direction of the tape member 6 are the same direction, and it comprises a linear first intervening 91 provided in the valley portion between adjacent first electric wires 2 in the circumferential direction of the cable, and a pair of linear second intervenings 92 provided in the valley portion between adjacent multi-core wires 8 and one and the other first electric wires 2 in the circumferential direction of the cable, and the tape member 6 is in contact with all the first electric wires 2 and multi-core wires 8 and the first intervenings 91 and second intervenings 92 that constitute the twisted body 5. With this configuration, it is possible to realize a cable 1 that improves terminal processability while maintaining durability against twisting.

[0065] (Summary of the embodiments) Next, the technical concept understood from the embodiments described above will be described using the reference numerals and other symbols from the embodiments. However, the reference numerals and other symbols in the following description are not limited to the components in the claims that are specifically shown in the embodiments.

[0066] [1] A multi-core wire (8) having a pair of first wires (2) and a pair of second wires (3) having a smaller outer diameter than the first wires (2) twisted together to form a pair of twisted wires (4), a tape member (6) spirally wrapped around a twisted body (5) formed by twisting the pair of first wires (2) and the multi-core wire (8), and an outer sheath (7) covering the outer circumference of the tape member (6), wherein the pair of first wires (2) are in contact with each other, and each of the first wires (2) and the multi-core wire (8) are in contact with each other, and the twisted body (5) A cable (1) wherein the twisting direction of the wires and the winding direction of the tape member (6) are the same direction, and the cable (1) comprises a linear first intervening (91) provided in the valley portion between adjacent first electric wires (2) in the circumferential direction of the cable, and a pair of linear second intervenings (92) provided in the valley portion between adjacent multi-core wires (8) in the circumferential direction of the cable and one and the other first electric wires (2), and the tape member (6) is in contact with all of the first electric wires (2), multi-core wires (8), first intervenings (91) and second intervenings (92) that constitute the twisted body (5).

[0067] [2] The cable (1) according to [1], wherein the first intervening (91) and the second intervening (92) are made of a crosslinked resin composition.

[0068] [3] The cable (1) according to [1], wherein at least one of the first intervening (91) and the second intervening (92) is a wire break detection wire.

[0069] [4] The cable (1) according to [1], wherein the arithmetic mean roughness Ra of the surfaces of the first intervening (91) and the second intervening (92) is 1 μm or more and 30 μm or less.

[0070] [5] The cable (1) according to [1], wherein the multi-core wire is composed only of the paired wires (4), and the twisting direction of the paired wires (4), the twisting direction of the twisted body (5), and the winding direction of the tape member (6) are all in the same direction.

[0071] [6] The cable (1) according to [1], wherein the tape member (6) is formed by mixing a first fiber having a melting point higher than the extrusion molding temperature of the outer sheath (7) and a second fiber having a melting point lower than the extrusion molding temperature of the outer sheath (7).

[0072] 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. In addition, the present invention can be implemented with appropriate modifications without departing from its spirit. [Explanation of Symbols]

[0073] 1… Cable 2…First power line 3…Second power line 4…Twisted wire 5...Twist union 6… Tape component 7... External sheath 8…Multi-core wire 81...Internal sheath 9…intervention 91…first intervention 92…Second intervention

Claims

1. A pair of first wires, A multi-core wire having a pair of twisted wires formed by twisting together a pair of second wires having a smaller outer diameter than the first wire, A tape member is spirally wrapped around the twisted body formed by twisting together the pair of first electric wires and the multi-core wires, The tape member comprises an outer sheath covering the outer circumference, The pair of first wires are in contact with each other, and each of the first wires is in contact with the multi-core wire. The twisting direction of the twisted body and the winding direction of the tape member are in the same direction. A linear first intervening is provided in the valley portion between adjacent first electric wires in the circumferential direction of the cable, The cable comprises a pair of linear second intervenes provided in the valleys between the multi-core wires adjacent to each other in the circumferential direction of the cable and the first wires, The tape member is in contact with all of the first electric wires, the multi-core wires, the first intervening, and the second intervening that constitute the twisted body. The first intervening and the second intervening are made of a crosslinked resin composition. The tape member is formed by mixing a first fiber having a melting point higher than the extrusion molding temperature of the outer sheath and a second fiber having a melting point lower than the extrusion molding temperature of the outer sheath. cable.

2. At least one of the first intervening and the second intervening is a wire break detection wire. The wire break detection wire is constructed by covering a stranded conductor with an insulator made of the crosslinked resin composition. The cable according to claim 1.

3. The arithmetic mean roughness Ra of the surfaces of the first intervening and the second intervening is 1 μm or more and 30 μm or less. The cable according to claim 1.

4. The multi-core wire is composed solely of the twisted-pair wires, The twisting direction of the paired wires, the twisting direction of the twisted body, and the winding direction of the tape member are all in the same direction. The cable according to claim 1.

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