Cable and damage detection device
By adopting a spiral winding structure with the opposite direction of the spiral direction of the pressed winding belt in the cable, and combining a linear conductor to detect the current state, the problems of cable bending tendency and damage detection are solved, and the wear resistance and efficient damage detection of the cable are achieved.
Patent Information
- Application Number
- CN202411828457.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-01-10
- Filing Date
- 2024-12-12
- Publication Date
- 2025-07-11
AI Technical Summary
Existing cables are prone to wear and trauma when bending, and it is difficult to effectively detect damage, especially when cables in automotive suspension devices are prone to contact with components, resulting in wear.
A spiral winding structure is adopted, and the conductive tape is opposite to the spiral direction of the pressing winding tape, and a linear conductor is provided in the cable length direction, so that damage is detected by detecting the current state of the conductive tape and the linear conductor.
It effectively suppresses the bending tendency of the cable, improves the sensitivity of damage detection, and can promptly detect signs of wear and disconnection of the cable, reducing misdetects and omissions.
Smart Images
Figure CN120299794A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a cable and a damage detection device for detecting damage to the cable. Background Art
[0002] Conventionally, there have been known a cable and a detection device that can electrically detect the occurrence of damage when damage occurs in a cable having a plurality of electric wires (for example, refer to Patent Document 1).
[0003] Patent Document 1 describes a cable that has an outer detection layer made of a conductive band having conductivity on the outer periphery of a tape layer formed of a tape body wound around the outer periphery of a wire group formed by bundling a plurality of electric wires, so as to be able to detect damage caused by trauma when a sudden impact is applied from the outside. The conductive band is wound in a spiral shape centered on the wire group along the axial direction of the wire group. The tape body forming the tape layer is made of an insulating material such as paper or resin. When the conductive band breaks, the characteristic impedance of the conductive band changes, and the change in the characteristic impedance is detected by a detection device.
[0004] In addition, in Patent Document 1, in applications where the influence is large in the case of wire breakage, such as in an automotive braking system, and the significance of pre-detecting wire breakage is great, this cable can be appropriately used.
[0005] Prior Art Documents
[0006] Patent Documents
[0007] Patent Document 1: Japanese Patent No. 7151754 Gazette Summary of the Invention
[0008] Problems to be Solved by the Invention
[0009] A part of the length direction of a cable for supplying power and controlling an electric parking brake device that locks the rotation of wheels when a vehicle is parked or an electric braking device that brakes the rotation of wheels during vehicle travel is installed in the air within a wheel housing. In this case, if the bending tendency of the cable is large, it is likely to easily cause abrasion and trauma due to contact between the cable and components of the suspension device. It should be noted that the bending tendency of the cable refers to the property that the cable naturally bends in a certain direction even when there is no external force acting on the cable in its single state. For example, as in the cable described in Patent Document 1, when a conductive band and an insulating tape body are wound around the outer periphery of a wire group, the cable may also have a bending tendency due to the conductive band and the tape body.
[0010] Therefore, an object of the present invention is to provide a cable having a conductive band for detecting damage to the cable and capable of suppressing the bending tendency, and a damage detection device for detecting damage to the cable.
[0011] Method for solving problems
[0012] An object of the present invention is to solve the above problems, and to provide a cable including a wire bundle formed by bundling a plurality of wires, a pressing winding tape spirally wound around the outer periphery of the wire bundle, a conductive tape spirally wound around the outer periphery of the pressing winding tape, and a sheath covering the pressing winding tape and the conductive tape; the conductive tape is spirally wound around the outer periphery of the pressing winding tape in such a manner that one end in the width direction does not overlap with the other end, and the spiral winding direction of the conductive tape is opposite to the spiral winding direction of the pressing winding tape.
[0013] In addition, an object of the present invention is to solve the above problems, and to provide a damage detection device that detects damage to a cable, the cable further including a linear conductor electrically connected to the conductive tape at one end in the cable length direction, wherein a current flows through the conductive tape and the linear conductor, and when the current is in a non-conductive state, a damage detection signal indicating that damage has occurred to the cable is output.
[0014] Advantages of the invention
[0015] According to the cable and the damage detection device of the present invention, although there is a conductive tape for detecting damage to the cable, the bending tendency of the cable can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 is a cross-sectional view of a cable according to a first embodiment of the present invention.
[0017] Figure 2 is an explanatory diagram showing the configuration of a wire bundle, a pressing winding tape, a conductive tape, and a linear conductor.
[0018] Figure 3 are perspective views separately showing the pressing winding tape and the conductive tape, respectively.
[0019] Figure 4 is a cross-sectional view of the pressing winding tape and the conductive tape in a spirally wound state.
[0020] Figure 5 In, (a) is a circuit diagram showing a configuration example of a damage detection device for detecting damage to a cable, and (b) is a cross-sectional view showing a configuration example of a linear conductor.
[0021] Figure 6 is a cross-sectional view of a cable of a comparative example.
[0022] Figure 7 In, (a) is a perspective view separately showing a conductive tape of a modification of the first embodiment, and (b) is a cross-sectional view of the modification of the conductive tape.
[0023] Figure 8 In the figure, (a) is a cross-sectional view of a cable showing a second embodiment of the present invention, and (b) is a cross-sectional view of a vulnerable wire of the cable of the second embodiment.
[0024] Figure 9 is a circuit diagram showing a configuration example of a damage detection device of the second embodiment.
[0025] Figure 10 is a cross-sectional view of a cable of the third embodiment.
[0026] Figure 11 is a configuration diagram showing a state of observing a wire harness, a pressing winding tape, a conductive tape, and a linear conductor of the third embodiment from the radial direction of the cable.
[0027] Description of Reference Numerals
[0028] 1, 1B, 1C... cables, 10... wire harness, 11, 12... damage detection devices, 2... first wire, 3... second wire, 4... third wire, 5... pressing winding tape, 6, 6A... conductive tapes, 7... linear conductor, 8... sheath. Detailed Embodiment
[0029] [First Embodiment]
[0030] Figure 1 is a cross-sectional view of a cable 1 of a first embodiment of the present invention. The cable 1 includes a wire harness 10 formed by stranding a plurality of wires 2 to 4, a pressing winding tape 5 spirally wound around the outer periphery of the wire harness 10, a conductive tape 6 of a spiral shape wound around the outer periphery of the pressing winding tape 5, a linear conductor 7 covered with the pressing winding tape 5 together with the wire harness 10, a sandwiching member 100, and a sheath 8 covering the pressing winding tape 5 and the conductive tape 6.
[0031] In the present embodiment, the first wire 2 and the second wire 3 among the plurality of wires 2 to 4 are power supply wires for supplying operating power to the target device. The third wire 4 is a multi-core wire in which a pair of signal wires 41 and 42 are covered with an inner sheath 43. Further, in the present embodiment, one end of each of the first to third wires 2 to 4 of the cable 1 is connected to a sub-frame member of the vehicle, and the other end of each of the first to third wires 2 to 4 is connected to a control device disposed on the vehicle body side as a super-frame member. The target device under the sub-frame supplied with power by the first wire 2 and the second wire 3 is, for example, an electric parking brake device that locks the wheels when the vehicle stops. A pair of signal wires 41 and 42 of the third wire 4 are connected to, for example, a wheel speed sensor that detects the rotational speed of the wheel, and transmits the output signal of the wheel speed sensor. As the suspension spring expands and contracts during vehicle travel, a part of the cable 1 in the length direction is repeatedly bent.
[0032] The first electric wire 2 is an insulated coated electric wire in which the conductor 21 is coated with an insulator 22. The second electric wire 3 is an insulated coated electric wire in which the conductor 31 is coated with an insulator 32. The conductors 21 and 31 are stranded wires formed by twisting a plurality of wires 210 and 310 made of a metal having good conductivity such as copper. A pair of signal wires 41 and 42 of the third electric wire 4 are insulated coated electric wires in which conductors 411 and 421 are coated with insulators 412 and 422, respectively. The conductors 411 and 421 are stranded wires formed by twisting a plurality of wires 410 and 420 made of a metal having good conductivity such as copper. The insulators 22 and 32 of the first and second electric wires 2 and 3 and the insulators 412 and 422 of the pair of signal wires 41 and 42 of the third electric wire 4 are made of, for example, fluororesin.
[0033] The outer diameter of the signal wires 41 and 42 of the third wire 4 is smaller than the outer diameter of the first wire 2 and the second wire 3, and the outer diameter of each of the signal wires 41 and 42 is less than half of the outer diameter of the first wire 2 and the second wire 3. It should be noted that in the present embodiment, the wire bundle 10 is configured to have one multi-core wire (the third wire 4), but the plurality of wires constituting the wire bundle may also include a plurality of multi-core wires. In addition, the plurality of wires constituting the wire bundle may not include a multi-core wire.
[0034] Figure 2 This is a structural diagram showing a state where the wire bundle 10, the pressing winding tape 5, the conductive tape 6, and the linear conductor 7 are viewed from the radial direction of the cable 1, omitting the illustration of the intervening object 100 and the sheath 8. Figure 2 In FIG. 1 , the conductive tape 6 is shown in gray, the outline of the inner sheath 43 of the third electric wire 4 is shown by an imaginary line (two-dot chain line) in a portion in the longitudinal direction of the electric wire bundle 10 , and the pair of signal wires 41 , 42 are shown by solid lines.
[0035] like Figure 2 As shown, the first to third electric wires 2 to 4 are twisted together, and a pair of signal wires 41 and 42 of the third electric wire 4 are further twisted inside the inner sheath 43 to form a twisted pair. Figure 1 In the middle, use arrow A 10 The arrow A4 indicates the twisting direction of the first to third electric wires 2 to 4, and the arrow A4 indicates the twisting direction of the pair of signal wires 41 and 42 in the third electric wire 4. Figure 1 and Figure 2 As shown, in the present embodiment, the twisting direction of the first to third electric wires 2 to 4 as viewed in the longitudinal direction of the cable 1 is the same as the twisting direction of the pair of signal wires 41 and 42 .
[0036] In addition, Figure 1 In the figure, use arrow A 21 , A 31 , A 41 , A 42Indicates the twisting directions of the multiple wire rods 210 in the conductor 21 of the first wire 2, the twisting directions of the multiple wire rods 310 in the conductor 31 of the second wire 3, and the twisting directions of the multiple wire rods 410, 420 of the pair of signal wires 41, 42 in the third wire 4. The twisting directions of these wire rods 210, 310, 410, 420 are the same as the twisting directions of the first to third wires 2 to 4 and the twisting directions of the pair of signal wires 41, 42. Thus, it is difficult to untwist the first to third wires 2 to 4.
[0037] The sandwiching member 100 is formed of a fibrous body such as aromatic polyamide fiber, Kevlar (registered trademark), etc., and is disposed by being sandwiched between the first to third wires 2 to 4 and the pressing winding tape 5. Through this sandwiching member 100, the shape of the pressing winding tape 5 in a cross-section perpendicular to the length direction of the cable 1 approaches a circle. That is, the sandwiching member 100 circularizes the shape of the pressing winding tape 5 in a cross-section perpendicular to the length direction of the wire harness 10. Thus, the cable 1 can be bent softly in all directions.
[0038] The outer diameter of the first wire 2 is the same as the outer diameter of the second wire 3. In addition, the outer diameter of the third wire 4 is of the same degree as the outer diameters of the first wire 2 and the second wire 3. Specifically, the outer diameter of the third wire 4 is 95% or more and 105% or less of the outer diameters of the first wire 2 and the second wire 3. This dimensional relationship helps to circularize the shape of the pressing winding tape 5 in a cross-section perpendicular to the length direction of the wire harness 10.
[0039] In Figure 1 In the example shown, near the center portion of the cable 1, a part of the outer peripheral surfaces 2a, 3a, 4a of the first to third wires 2 to 4 are in contact with each other, and a part of the outer peripheral surfaces 2a, 3a, 4a of the first to third wires 2 to 4 are in contact with one surface 5a of the pressing winding tape 5, but the outer peripheral surfaces 2a, 3a, 4a of the first to third wires 2 to 4 may not be in contact with each other, and the outer peripheral surfaces 2a, 3a, 4a of the first to third wires 2 to 4 may not be in contact with the pressing winding tape 5.
[0040] In Figure 2 , θ1 is used to represent the inclination angle of the pressing winding tape 5 with respect to the length direction of the cable 1, and θ2 is used to represent the inclination angle of the conductive tape 6 with respect to the length direction of the cable 1. In addition, in Figure 2Among them, P1 represents the spiral winding pitch of the pressing winding tape 5 in the length direction of the cable 1, P2 represents the spiral winding pitch of the conductive tape 6 in the length direction of the cable 1, and P0 represents the twisting pitch of the first to third wires 2 to 4. It should be noted that here, the spiral winding pitch refers to the length that the pressing winding tape 5 and the conductive tape 6 advance in the length direction of the wire harness 10 during one round around the outer periphery of the wire harness 10 when the pressing winding tape 5 and the conductive tape 6 are wound around the outer periphery of the wire harness 10. In addition, the twisting pitch refers to the length that the first to third wires 2 to 4 advance in the length direction of the wire harness 10 during one round around the center of the wire harness 10.
[0041] As Figure 2 shown, the inclination angle θ2 of the conductive tape 6 with respect to the length direction of the cable 1 is larger than the inclination angle θ1 of the pressing winding tape 5, and the spiral winding pitch P2 of the conductive tape 6 in the length direction of the cable 1 is narrower than the spiral winding pitch P1 of the pressing winding tape 5. In addition, the spiral winding pitch P2 of the conductive tape 6 and the spiral winding pitch P1 of the pressing winding tape 5 are narrower than the twisting pitch P0 of the first to third wires 2 to 4.
[0042] Figure 3 is a perspective view separately showing the pressing winding tape 5 and the conductive tape 6. Figure 4 is a cross-sectional view showing the pressing winding tape 5 wound in a spiral shape and the conductive tape 6 wound around its outer periphery.
[0043] The conductive tape 6 is a conductive strip. In the present embodiment, the conductive tape 6 is a strip-shaped metal foil made of a metal with good conductivity such as copper, silver, or aluminum. The conductive tape 6 is wound around the outer periphery of the pressing winding tape 5 in such a way that one surface 6a contacts the other surface 5b of the pressing winding tape 5. One surface 6a of the conductive tape 6 is given adhesiveness through an adhesive and adhered to the other surface 5b of the pressing winding tape 5. The other surface 6b of the conductive tape 6 contacts the sheath 8. It should be noted that as long as the position shift of the conductive tape 6 in the length direction of the cable 1 is sufficiently suppressed by the frictional force with the pressing winding tape 5 or the sheath 8 to prevent one end from contacting the other end in the width direction of different turns of the conductive tape 6, adhesiveness may not be given to one surface 6a of the conductive tape 6.
[0044] In Figure 3In this case, W1 represents the width of the pressing winding tape 5, and W2 represents the width of the conductive tape 6. The width W1 of the pressing winding tape 5 is wider than the width W2 of the conductive tape 6. The preferred range of the width W2 of the conductive tape 6 relative to the width W1 of the pressing winding tape 5 is, for example, 10% or more and 30% or less. In addition, in the present embodiment, the thickness of the conductive tape 6 is thinner than the thickness of the pressing winding tape 5. However, it is not limited thereto, and the conductive tape 6 may also be thicker than the pressing winding tape 5. The narrower the width and the thinner the thickness of the conductive tape 6, the higher the sensitivity when the cable 1 is damaged. On the other hand, for example, wear and distortion are likely to occur due to friction with the sheath 8 when the cable 1 is bent. Therefore, the width and thickness of the conductive tape 6 are preferably adjusted appropriately according to the use and usage environment of the cable 1.
[0045] The pressing winding tape 5 is, for example, a strip-shaped body made of a resin such as non-woven fabric, paper, or polyester, and is pressed and wound so as to press the first to third electric wires 2 to 4 toward the central portion of the cable 1. In addition, the pressing winding tape 5 is overlapped and wound around the outer periphery of the wire harness 10 in such a manner that the ends in the width direction thereof coincide with each other in the radial direction of the cable 1. More specifically, one surface 5a of the end on one side in the width direction of the pressing winding tape 5 and the other surface 5b of the end on the other side in the width direction of the pressing winding tape 5 overlap and contact in the thickness direction of the pressing winding tape 5. In the longitudinal direction of the cable 1 ( Figure 4 the left-right direction), the ratio of the overlapping length L2 of the pressing winding tape 5 in one turn to the length L1 of the pressing winding tape 5 is, for example, 10% or more and 40% or less.
[0046] The conductive tape 6 is thick-wound around the outer periphery of the pressing winding tape 5 in such a manner that one end and the other end in the width direction do not coincide with each other. A gap is formed between one end and the other end in the width direction of the conductive tape 6, and the other surface 5b of the pressing winding tape 5 is exposed in the gap. The sheath 8 contacts one surface 5a of the pressing winding tape 5 in the gap.
[0047] The sheath 8 is made of a urethane resin such as thermoplastic polyurethane, for example, and is extrusion-molded on the outer periphery of the pressing winding tape 5. The pressing winding tape 5 covers the entire circumference of the wire harness 10 in a cross-sectional view. Thus, when the sheath 8 is molded, the liquid thermoplastic resin forming the sheath 8 is prevented from entering between the first to third electric wires 2 to 4.
[0048] In Figure 1 this case, the spiral winding direction of the pressing winding tape 5 is indicated by an arrow A5, and the spiral winding direction of the conductive tape 6 is indicated by an arrow A6. As Figure 1As shown in the figure, when observing the wire harness 10, the pressing winding tape 5, and the conductive tape 6 from a cross-section perpendicular to the longitudinal direction of the cable 1 along the longitudinal direction of the cable 1, the twisting directions of the first to third wires 2 to 4 in the wire harness 10 are opposite to the spiral winding direction of the pressing winding tape 5. Additionally, the spiral winding direction of the conductive tape 6 is the same as the twisting directions of the first to third wires 2 to 4 in the wire harness 10 and opposite to the spiral winding direction of the pressing winding tape 5.
[0049] The cable 1 configured as described above may, for example, be externally damaged by being hit by flying stones or the like during vehicle travel, or the sheath 8 may be severely worn due to friction with the outside. In the present embodiment, when the cable 1 is damaged due to such external damage or wear, the occurrence of the damage is detected by a damage detection device described below.
[0050] Figure 5 (a) is a circuit diagram showing a configuration example of a damage detection device 11 for detecting damage to the cable 1. Figure 5 (b) is a cross-sectional view showing a configuration example of the linear conductor 7. The damage detection device 11 includes the conductive tape 6 and the linear conductor 7 as constituent elements, and is configured to have a damage detection circuit 110 for electrically detecting the occurrence of damage in the cable 1.
[0051] As Figure 5 (b) shows, the linear conductor 7 is an insulated coated wire having a conductor 71 and an insulator 72 covering the conductor 71. In Figure 5 (b) the example shown, the conductor 71 is a stranded wire formed by stranding a plurality of wire materials 710, but is not limited thereto, and the conductor 71 may also be a single wire. Additionally, the insulator 72 may be omitted, and the linear conductor 7 may be a non-coated wire (bare wire).
[0052] The linear conductor 7 is arranged inside the pressing winding tape 5 together with the first to third wires 2 to 4, and the conductor 71 of the linear conductor 7 is electrically connected to the conductive tape 6 at one end portion in the longitudinal direction of the cable 1. In the present embodiment, this end portion corresponds to the end portion on the lower side of the vehicle's spring. It should be noted that in Figure 5 (a) the example shown, the case where the conductive tape 6 and the linear conductor 7 are connected by a terminal resistor Rt is shown, but is not limited thereto, and the conductor 71 of the linear conductor 7 may also be directly connected to the conductive tape 6 to short-circuit them.
[0053] The bending durability of the linear conductor 7 is lower than that of the first to third wires 2 to 4, and when the cable 1 is repeatedly bent, it will break before any of the first to third wires 2 to 4 break. In addition, the conductor cross-sectional area of the conductor 71 of the linear conductor 7 is smaller than the conductor cross-sectional area of the conductor 21 of the first wire 2, the conductor cross-sectional area of the conductor 31 of the second wire 3, and the conductor cross-sectional areas of the conductor 411 and 421 of the signal lines 41 and 42 of the third wire 4, respectively.
[0054] In the present embodiment, as Figure 1 shown, the linear conductor 7 is disposed between the first wire 2 and the second wire 3 and the pressing winding tape 5. However, the arrangement position of the linear conductor 7 is not limited thereto. For example, the linear conductor 7 may be disposed at the center of the cable 1 surrounded by the first to third wires 2 to 4. The linear conductor 7 may be separated from the wire harness 10 as Figure 1 shown, or may be in contact with the wire harness 10.
[0055] The damage detection circuit 110 is provided on the side opposite to the side (upper side of the spring) electrically connected to the conductive tape 6 and the conductor 71 of the linear conductor 7 in the length direction of the cable 1. A current flows through the conductive tape 6 and the linear conductor 7, and when this current is in a non-conductive state, a damage detection signal indicating that the cable 1 has been damaged is output. When the damage detection signal is output, for example, the occurrence of damage to the cable 1 is reported to the driver by lighting a lamp on the instrument panel of the vehicle.
[0056] In Figure 5 the circuit structure example of the damage detection circuit 110 shown in (a), a shunt resistor Rs, a conductive tape 6, a terminal resistor Rt, and a linear conductor 7 are connected in series between the + side and the - side of the DC power supply V. In addition, the damage detection circuit 110 includes first and second reference resistors Ra and Rb and a comparator C connected in series between the + side and the - side of the DC power supply V, and is configured to input the reference voltage Vref obtained by resistively dividing the voltage of the DC power supply V by the first and second reference resistors Ra and Rb and the detection voltage Vd on the conductive tape 6 side of the shunt resistor Rs to the comparator C.
[0057] When no break occurs in the conductive tape 6 and the conductor 71 of the linear conductor 7 and a predetermined current flows through the series circuit composed of the shunt resistor Rs, the conductive tape 6, the terminal resistor Rt, and the linear conductor 7, a voltage drop corresponding to the magnitude of the current is generated in the shunt resistor Rs, and the detection voltage Vd is lower than the voltage of the DC power supply V. On the other hand, when any one of the conductive tape 6 and the conductor 71 of the linear conductor 7 breaks, no current flows through this series circuit, and the detection voltage Vd is equal to the voltage of the DC power supply V.
[0058] The reference voltage Vref is adjusted to a value between the detection voltage Vd when no disconnection occurs in the conductor 71 of the conductive tape 6 and the linear conductor 7 and the detection voltage Vd when a disconnection occurs in any one of the conductors 71 of the conductive tape 6 and the linear conductor 7. If a disconnection occurs in any one of the conductors 71 of the conductive tape 6 and the linear conductor 7, the output voltage Vout of the comparator C changes. The output voltage Vout of the comparator C is output as a damage detection signal indicating that the cable 1 has been damaged from the damage detection circuit 110.
[0059] [Comparative Example]
[0060] Figure 6 is a cross-sectional view of the cable 1A showing the comparative example. In Figure 6 for the components common to those of the cable 1 of the first embodiment, the same reference numerals as those labeled in Figure 1 etc. are labeled, and repeated descriptions are omitted.
[0061] In the cable 1A, the shape of the pressing winding tape 5 in a cross-section perpendicular to the length direction is a triangular shape with rounded corners. That is, at each corner of this triangular shape, the pressing winding tape 5 bends along the outer peripheral surfaces 2a, 3a, and 4a of the first wire 2, the second wire 3, and the third wire 4 with the curvature of the outer peripheral surfaces 2a, 3a, and 4a.
[0062] In this cable 1A, compared with the cable 1 according to the first embodiment, at each corner of the above triangular shape, the conductive tape 6 is subjected to stress generated by bending with a larger curvature, and the conductive tape 6 is likely to break due to this stress, and false detection of damage is likely to occur. In contrast, in the cable 1 according to the first embodiment, the shape of the pressing winding tape 5 in a cross-section perpendicular to the length direction of the wire bundle 10 is circularized, and the curvature of the pressing winding tape 5 is smaller than the curvature of the outer peripheral surfaces 2a, 3a, and 4a of the first to third wires 2 to 4. Therefore, the conductive tape 6 wound around the outer periphery of the pressing winding tape 5 is less likely to generate stress caused by bending, and the occurrence of false detection can be suppressed.
[0063] (Effect of the First Embodiment)
[0064] According to the first embodiment described above, since the spiral winding direction of the conductive tape 6 is opposite to the spiral winding direction of the pressing winding tape 5, the bending tendency of the cable 1 caused by the spiral winding of the pressing winding tape 5 and the bending tendency of the cable 1 caused by the spiral winding of the conductive tape 6 cancel each other out. Thus, the bending tendency of the cable 1 is suppressed as a whole.
[0065] In addition, according to the first embodiment, since the spiral winding direction of the pressing winding tape 5 is opposite to the twisting direction of the first to third electric wires 2 to 4, the bending tendency of the cable 1 caused by the twisting of the first to third electric wires 2 to 4 and the bending tendency of the cable 1 caused by the spiral winding of the pressing winding tape 5 cancel each other out, and the over-twisting of the first to third electric wires 2 to 4 due to the co-rotation with the pressing winding tape 5 when winding the pressing winding tape 5 is suppressed.
[0066] In addition, according to the first embodiment, since the spiral winding pitch of the conductive tape 6 is narrower than the spiral winding pitch of the pressing winding tape 5, compared with the case where the conductive tape 6 is spiral-wound with the spiral winding pitch P1 of the pressing winding tape 5 shown, for example, Figure 2 the number of turns of the conductive tape 6 per unit length in the longitudinal direction of the cable 1 increases, and even if the size of the damage is small when an injury occurs to the sheath 8, the occurrence of the damage can be detected.
[0067] In addition, in the first embodiment, the width of the pressing winding tape 5 is wider than the width of the conductive tape 6, and the inclination angle of the pressing winding tape 5 with respect to the longitudinal direction of the cable 1 is smaller than the inclination angle of the conductive tape 6. Therefore, compared with the case where the pressing winding tape 5 is spiral-wound with the inclination angle θ2 of the conductive tape 6 shown, for example, Figure 2 the number of turns of the pressing winding tape 5 per unit length of the cable 1 can be reduced, and the man-hours required for manufacturing the cable 1 can be reduced. That is, in the first embodiment, by making the spiral winding pitch of the conductive tape 6 narrower than the spiral winding pitch of the pressing winding tape 5 and making the width of the pressing winding tape 5 wider than the width of the conductive tape 6, the sensitivity to damage to the cable 1 is improved and the manufacturing cost is suppressed. It should be noted that when a strip-shaped body such as the pressing winding tape 5 is wound in an overlapping manner, there is a correlation between the width and the inclination angle of the strip-shaped body. If the width is widened, the inclination angle becomes smaller, and if the width is narrowed, the inclination angle becomes larger.
[0068] In addition, according to the first embodiment, the linear conductor 7 has lower bending durability than the first to third electric wires 2 to 4. When the linear conductor 7 is broken, the occurrence of this break is also detected by the damage detection circuit 110. Therefore, in addition to sudden external injuries caused by collisions such as flying stones and wear of the sheath 8, the occurrence of breaks in the first to third electric wires 2 to 4 due to metal fatigue caused by repeated bending can be detected by the break of the linear conductor 7.
[0069] [Modification Example of the First Embodiment]
[0070] Figure 7 (a) is a perspective view showing the conductive tape 6A of the modification example of the first embodiment alone. Figure 7 (b) is a cross-sectional view of the conductive tape 6A in a cross-section perpendicular to the longitudinal direction of the conductive tape 6A. It should be noted that inFigure 7 (a) and (b) exaggerate the thickness of the conductive band 6A for clarity of illustration.
[0071] The conductive band 6A has a base material 61 made of a strip-shaped insulator and a conductive layer 62 provided on one surface 61a side of the base material 61. The conductive layer 62 is strengthened by the base material 61 and is not easily broken even when repeatedly bent. In this example, the strip-shaped conductive layer 62 is joined to one surface 61a of the base material 61 via an adhesive layer 63. An adhesive layer 64 is provided on the other surface 61b of the base material 61. It should be noted that the conductive layer 62 can also be formed on one surface 61a of the base material 61 by vapor deposition.
[0072] Instead of the conductive band 6 of the first embodiment, the conductive band 6A is wound around the outer periphery of the pressing winding band 5 in a spiral shape in the same manner as the conductive band 6. When winding the conductive band 6A, it can be wound such that the conductive layer 62 is on the outer side (sheath 8 side) relative to the base material 61, or it can be wound such that the conductive layer 62 is on the inner side (pressing winding band 5 side) relative to the base material 61. If the conductive layer 62 is on the outer side relative to the base material 61, damage to the cable 1 can be detected with high sensitivity. In addition, if the conductive layer 62 is on the inner side relative to the base material 61, wear of the conductive layer 62 due to friction with the sheath 8 can be prevented. It should be noted that in order to prevent the positional deviation of the conductive band 6A, an adhesive layer can be provided on the surface of the conductive band 6A on the pressing winding band 5 side.
[0073] When using this conductive band 6A, in order to detect a break in the conductive layer 62 by the damage detection device 11 when the conductive layer 62 is broken, a shunt resistor Rs, the conductive layer 62 of the conductive band 6A, a terminal resistor Rt, and a linear conductor 7 are connected in series between the + side and the - side of the DC power supply V of the damage detection circuit 110.
[0074] When using the conductive band 6A of this modification, the same effect as the first embodiment can also be obtained. It should be noted that the conductive layer 62 can be provided only on one surface 61a side of the base material 61 as shown in Figure 7 (a) and (b), or conductive layers 62 can be provided on one surface 61a side and the other surface 61b side of the base material 61, respectively. In this case, at the end portion in the length direction of the conductive band 6A, the conductive layer 62 on one surface 61a side of the base material 61 is electrically connected to the conductive layer 62 on the other surface 61b side, and one of the two conductive layers 62 is set as the path of the current supplied from the damage detection circuit 110, and the other is set as the return path of the current, so that the linear conductor 7 can be omitted.
[0075] [Second Embodiment]
[0076] Figure 8(a) is a cross-sectional view of a cable 1B showing a second embodiment of the present invention. The cable 1B of the second embodiment is a cable in which a fragile wire 9 with lower bending durability and easier to break than the first to third wires 2 to 4 is added to the cable 1 of the first embodiment. The fragile wire 9 is arranged at the center of the cable 1B surrounded by the first to third wires 2 to 4 and extends along the length direction of the cable 1B.
[0077] Figure 8 (b) is a cross-sectional view of the fragile wire 9. The fragile wire 9 is an insulated coated wire having a conductor 91 and an insulator 92 covering the conductor 91. The conductor 91 is a stranded wire formed by stranding a plurality of wire materials 910, but is not limited thereto, and the conductor 91 may also be a single wire. In addition, the insulator 92 may be omitted and the fragile wire 9 may be a non-coated wire (bare wire).
[0078] The fragile wire 9 is used to detect the omen before any one of the first to third wires 2 to 4 breaks due to repeated bending of the cable 1B. That is, in this embodiment, the occurrence of sudden trauma such as flying stones and the occurrence of damage such as wear of the sheath 8 are detected by the breakage of the conductive band 6, and the omen of the breakage caused by the metal fatigue of the conductors 21, 31, 411, and 421 of the first to third wires 2 to 4 is detected by the breakage of the fragile wire 9. The conductor thickness of the conductive band 6 is formed thinner than the conductor diameter of the conductor 91 of the fragile wire 9. Thereby, the wear of the sheath 8 and the occurrence of trauma can be detected sensitively.
[0079] It should be noted that in the cable 1B, the conductive band 6A shown in Figure 7 (a) and (b) may be used instead of the conductive band 6. In this case, the thickness of the conductive layer 62 of the conductive band 6A is formed thinner than the conductor diameter of the conductor 91 of the fragile wire 9.
[0080] Figure 9 is a circuit diagram showing a configuration example of a damage detection device 12 of a third embodiment. The damage detection device 12 includes a conductive band 6, a fragile wire 9, and a linear conductor 7 of the cable 1B as components, and is configured to have a damage detection circuit 120. The damage detection circuit 120 has a first circuit portion 121 for detecting the breakage of the conductive band 6 and a second circuit portion 122 for detecting the breakage of the conductor 91 of the fragile wire 9.
[0081] The first circuit section 121 of the damage detection circuit 120 includes reference resistors Ra1 and Rb1, a shunt resistor Rs1, and a comparator C1. The reference resistors Ra1 and Rb1 divide the voltage of the DC power supply V to generate a reference voltage Vref1. The comparator C1 compares the voltage on the conductive strip 6 side of the shunt resistor Rs1, i.e., the detection voltage Vd1, with the reference voltage Vref1. When the conductive strip 6 is broken, the output voltage Vout1 of the comparator C1 changes. The conductive strip 6 and the linear conductor 7 are electrically connected at the end portion of the cable 1B in the length direction, which corresponds to the end on the opposite side of the damage detection circuit 120, through the first terminal resistor Rt1.
[0082] The second circuit section 122 of the damage detection circuit 120 includes reference resistors Ra2, Rb2, shunt resistor Rs2, and comparator C2. The reference resistors Ra2 and Rb2 divide the voltage of the DC power supply V to generate a reference voltage Vref2. The comparator C2 compares the voltage on the fragile line 9 side of the shunt resistor Rs2, that is, the detection voltage Vd2, with the reference voltage Vref2. When the conductor 91 of the fragile line 9 is disconnected, the output voltage Vout2 of the comparator C2 changes. The conductor 91 of the fragile line 9 and the linear conductor 7 are electrically connected at the end portion of the cable 1B in the longitudinal direction, which corresponds to the end portion on the opposite side of the damage detection circuit 120, through the second terminal resistor Rt2.
[0083] The output voltage Vout1 of the comparator C1 of the first circuit unit 121 is output from the damage detection circuit 120 as a damage detection signal indicating that the cable 1B is damaged. The output voltage Vout2 of the comparator C2 of the second circuit unit 122 is output from the damage detection circuit 120 as a sign detection signal indicating that the first to third electric wires 2 to 4 of the cable 1B are disconnected. If the damage detection signal or the sign detection signal is output, it is notified to the driver by, for example, lighting of a lamp on the dashboard of the vehicle.
[0084] According to the second embodiment, it is possible to reduce the occurrence of detection omissions and misdetections while suppressing an increase in man-hours during manufacturing, and it is possible to detect an omen of disconnection caused by metal fatigue of the conductors 21, 31, 411, and 421 of the first to third wires 2 to 4 through the weak line 9. It should be noted that in the first embodiment, the bending durability of the linear conductor 7 is lower than that of the first to third wires 2 to 4. However, in the second embodiment, since it is possible to detect an omen of disconnection of the first to third wires 2 to 4 through the weak line 9, the bending durability of the linear conductor 7 may not be lower than that of the first to third wires 2 to 4. In addition, the weak line 9 does not necessarily have to be arranged at the center of the cable 1B, and the weak line 9 may be arranged between the first to third wires 2 to 4 and the pressing winding tape 5. In this case, the weak line 9 is stranded together with the first to third wires 2 to 4 and the linear conductor 7.
[0085] [Third Embodiment]
[0086] Figure 10 It is a cross-sectional view of the cable 1C of the third embodiment. Figure 11 It is a configuration diagram showing a state of observing the wire bundle 10, the pressing winding tape 5, the conductive tape 6, and the linear conductor 7 from the radial direction of the cable 1C with the interposed object 100 and the sheath 8 omitted.
[0087] In the first embodiment, the case where the twisting direction of the first to third wires 2 to 4 in the wire bundle 10 is opposite to the spiral winding direction of the pressing winding tape 5 and the spiral winding direction of the pressing winding tape 5 is opposite to the spiral winding direction of the conductive tape 6 has been described. However, in the third embodiment, the twisting direction of the first to third wires 2 to 4 in the wire bundle 10 is the same as the spiral winding direction of the pressing winding tape 5, and the spiral winding direction of the pressing winding tape 5 is opposite to the spiral winding direction of the conductive tape 6. The configuration of the cable 1C other than this is the same as the configuration of the cable 1 of the first embodiment. That is, in the third embodiment, the inclination angle θ2 of the conductive tape 6 with respect to the length direction of the cable 1C is larger than the inclination angle θ1 of the pressing winding tape 5, and the spiral winding pitch P2 of the conductive tape 6 in the length direction of the cable 1C is narrower than the spiral winding pitch P1 of the pressing winding tape 5.
[0088] According to this third embodiment, similarly to the first embodiment, the bending tendency of the cable 1C caused by the spiral winding of the pressing winding tape 5 and the bending tendency of the cable 1C caused by the spiral winding of the conductive tape 6 cancel each other out, thereby suppressing the bending tendency of the cable 1C caused by the spiral winding of the pressing winding tape 5 and the conductive tape 6. It should be noted that in the case where the cable 1C is damaged, the occurrence of this damage is detected by the damage detection device 11 described in the first embodiment.
[0089] (Summary of Embodiments)
[0090] Next, regarding the technical ideas grasped from the above-described embodiments and modified examples, the reference numerals in the embodiments and modified examples are cited for description. However, the reference numerals in the following description do not limit the components in the claims to the components specifically shown in the embodiments.
[0091] [1] A cable (1, 1B, 1C) includes a wire bundle (10) formed by bundling a plurality of wires (2 to 4), a pressing winding tape (5) spirally wound around the outer periphery of the wire bundle (10), a conductive tape (6, 6A) spirally wound around the outer periphery of the pressing winding tape (5), and a sheath (8) covering the pressing winding tape (5) and the conductive tape (6, 6A). The conductive tape (6, 6A) is spirally wound around the outer periphery of the pressing winding tape (5) such that one end in the width direction does not overlap with the other end, and the spiral winding direction of the conductive tape (6) is opposite to the spiral winding direction of the pressing winding tape (5).
[0092] [2] The cable (1, 1B) according to the above [1], wherein the plurality of wires (2 to 4) are stranded, and the spiral winding direction of the pressing winding tape (5) is opposite to the twisting direction of the plurality of wires (2 to 4).
[0093] [3] The cable (1, 1B, 1C) according to the above [1], wherein the spiral winding pitch (P2) of the conductive tape (6, 6A) is narrower than the spiral winding pitch (P1) of the pressing winding tape (5).
[0094] [4] The cable (1, 1B, 1C) according to the above [1], wherein the width (W1) of the pressing winding tape (5) is wider than the width (W2) of the conductive tape (6, 6A).
[0095] [5] The cable (1, 1B, 1C) according to any one of the above [1] to [4] further includes a linear conductor (7) electrically connected to the conductive tape (6, 6A) at one end in the cable length direction, and the linear conductor (7) is disposed inside the pressing winding tape (5) together with the plurality of wires (2 to 4).
[0096] [6] A damage detection device (11, 12) for detecting damage to the cable (1, 1B, 1C) according to the above [5]. A current flows through the conductive tape (6, 6A) and the linear conductor (7), and when the current is in a non-conductive state, a damage detection signal indicating that the cable (1, 1B, 1C) has been damaged is output.
[0097] As described above, the embodiments and modifications of the present invention have been explained. However, the above-described embodiments and modifications do not limit the invention of the claims. In addition, it should be noted that not all combinations of the features described in the embodiments and modifications are necessarily required for the means to solve the problems of the invention. In addition, the present invention can be appropriately modified and implemented without departing from its gist. For example, it can be implemented as follows.
[0098] In the above-described embodiment, the case where the third wire 4 as a multi-core wire has a plurality of signal wires 41 and 42 as small-diameter wires has been described. However, a plurality of small-diameter wires constituting the multi-core wire can also be used as power supply wires for supplying operating power to the target device. As the target device, for example, an active suspension device with variable damping force, a tire pressure detection device for detecting tire pressure, etc. can be cited.
[0099] In addition, in the above-described embodiment, the case where the first and second wires 2 and 3 are used as power supply wires for supplying operating power to the electric parking brake device and the signal wires 41 and 42 of the third wire 4 are used for transmitting the output signals of the wheel speed sensors has been described. However, the uses of the first to third wires 2 to 4 are not limited to this. For example, the first wire 2 and the second wire 3 can also be used as power supply wires for supplying operating power to an electric braking device that brakes the rotation of the wheels during vehicle travel, and the signal wires 41 and 42 of the third wire 4 can be used for transmitting control signals for controlling the electric braking device.
[0100] In addition, in the above-described embodiment, the case where three wires (the first to third wires 2 to 4) are bundled to form the wire harness 10 has been described. However, it is not limited to this, and the number of wires can also be two or four or more.
[0101] In addition, in the above-described embodiment, the case where a DC current always flows through the conductive bands 6 and 6A to detect the disconnection of the conductive bands 6 and 6A has been described. However, it is not limited to this. For example, a current can also flow intermittently through the conductive bands 6 and 6A to detect the disconnection of the conductive bands 6 and 6A.
[0102] In addition, in the above-described embodiment, the case where the cable 1 is mounted on a vehicle has been described. However, it is not limited to this, and the cable 1 can also be used for industrial machines such as robots and machine tools.
Claims
1. A cable, comprising: A wire harness formed by bundling a plurality of wires, A pressing winding tape spirally wound around the outer periphery of the wire harness, A conductive tape made of a conductive material, spirally wound around the outer periphery of the pressing winding tape, and A sheath covering the pressing winding tape and the conductive tape; The conductive tape is spirally wound around the outer periphery of the pressing winding tape in such a manner that one end portion in the width direction does not coincide with the other end portion, The spiral winding direction of the conductive tape is opposite to the spiral winding direction of the pressing winding tape.
2. The cable according to claim 1, wherein, The plurality of wires are twisted, and the spiral winding direction of the pressing winding tape is opposite to the twisting direction of the plurality of wires.
3. The cable according to claim 1, wherein The spiral winding pitch of the conductive tape is narrower than the spiral winding pitch of the pressing winding tape.
4. The cable according to claim 1, wherein, The width of the pressing winding tape is wider than the width of the conductive tape.
5. The cable according to any one of claims 1 to 4, wherein, A linear conductor electrically connected to the conductive tape at one end portion in the cable length direction is further provided, The linear conductor is disposed inside the pressing winding tape together with the plurality of wires.
6. A damage detection device for detecting damage to the cable according to claim 5, Causing current to flow through the conductive tape and the linear conductor, and outputting a damage detection signal indicating that the cable has been damaged when the current is in a non-conductive state.