Cable with abnormality sign detection function

Abstract

To provide a cable with an abnormality sign detection function capable of inputting an electric signal without using an external ground electrical potential, and detecting a sign in which breaking of a wire occurs on an electric cable.SOLUTION: A cable with an abnormality sign detection function comprises: an object electric cable comprising an electric cable conductor and an electric cable coating for covering an outer periphery of the electric cable conductor; and a detection cable 3 comprising a detection cable conductor 31 and a detection cable coating 32 for covering an outer periphery of the detection cable conductor 31. The detection cable conductor 31 as a whole has a shorter flexure life than the electric cable conductor. The detection cable conductor 31 comprises as a strand: inside strands 3a; and outside strands 3b whose flexure service life is shorter than that of the inside strand 3a. Each inside strand 3a is formed as a bare wire where a conductive material is exposed. On an outer periphery of a group of the inside strands 3a, the outside strands 3b are arranged in an insulated state from the group of the inside strands 3a.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a cable with an abnormality sign detection function. [Background technology]

[0002] Electric wires are installed and laid in various electrical and electronic devices, transportation equipment, buildings, public facilities, etc., and over time, they may suffer damage such as breakage. For example, repeated bending and vibration of an electric wire can cause metal fatigue, leading to breakage of the conductor that makes up the wire. It is preferable to detect damage such as breakage at a precursory stage, such as when metal fatigue is progressing, before it actually occurs. If damage to electric wires can be detected at a precursory stage, measures such as replacing the wire can be implemented, preventing malfunctions caused by the damage, such as the failure of equipment to which the wire is connected.

[0003] As a cable intended to detect signs of damage to electric wires, for example, Patent Document 1 discloses a cable with a wire breakage detection function that includes a detection wire having a conductor made of multiple strands twisted together and a detectable wire having a conductor made of multiple strands twisted together, where the twist pitch of the conductor of the detection wire is longer than the twist pitch of the conductor of the detectable wire.By making the twist pitch of the conductor of the detection wire longer than the twist pitch of the conductor of the detectable wire, the flex life of the detection wire is made shorter than the flex life of the detectable wire, thereby enabling prediction of wire breakage.

[0004] Furthermore, Patent Document 2 discloses a wire break detection device including an electric cable consisting of a plurality of electric wires, an electric shield layer covering the plurality of electric wires, and a sheath covering the electric shield layer, a wire break detection wire consisting of a conductor wire provided in the electric shield layer and an insulating layer surrounding the conductor wire, a voltage source electrically connected to the conductor wires, a first detector electrically connected to the conductor wires, and a second detector electrically connected to the electric shield layer. The flex life of the wire break detection wire is set shorter than the flex life of the electric wires. The document describes that a voltage is applied to the conductor wires of the wire break detection wire by the voltage source, and a wire break in the electric shield layer is predicted based on the detection signals of the first detector and the second detector.

[0005] Patent Document 3 discloses a cable with a disconnection detection function that includes a wire core in which a conductor is covered with an insulator and a disconnection detection wire, in which the disconnection detection wire is made up of multiple wires in which the conductor wire is covered with an insulator, and the multiple wires are made up of two or more types of wires with different flex lifes. Since the detection wire is made up of a combination of wires with different flex lifes, it is said that it is possible to cause the detection wire to disconnect in stages. Furthermore, by individually insulating the wires in the detection wire, it is said that a change in resistance due to a wire disconnection becomes clear, enabling more accurate disconnection detection. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-182716 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-305478 [Patent Document 3] Japanese Patent Application Laid-Open No. 2007-299608 Summary of the Invention [Problem to be solved by the invention]

[0007] As described in Patent Documents 1 to 3, a detection wire that is more likely to break when bent than the target electric wire is provided alongside the target electric wire for which signs of wire breakage are to be detected, and signs of wire breakage in the target electric wire can be detected by monitoring the breakage of the detection wire. One method for monitoring the breakage of the detection wire is to input an electrical signal such as an AC current into the conductor wire that constitutes the detection wire and monitor changes in the response signal obtained by reflection or transmission. In this case, a ground potential must be set to serve as a reference for the electrical signal and to ensure a return path for the electrical signal.

[0008] The ground potential for this disconnection detection can be the ground potential of the entire device, such as an automobile, that is equipped with electrical wires. However, various devices mounted on the device are typically connected to the ground potential of the entire device, and noise from the other devices is likely to be superimposed on the electrical signal for disconnection detection, often making accurate detection of disconnection signs difficult. Alternatively, a dedicated ground line can be installed separately for the detection line for disconnection detection instead of using the ground potential of the entire device. While this method can minimize the impact of noise, it requires a large number of electrical wires routed inside the device, resulting in a more complex internal structure and increased mass. If disconnection signs could be detected using a detection line without using the ground potential of the entire device or an external ground potential, such as a dedicated ground line, it would be possible to simplify the equipment required for disconnection detection while minimizing the impact of noise.

[0009] In view of the above, an object of the present invention is to provide a cable with an abnormality sign detection function that can detect signs of an electrical wire break by inputting an electrical signal without using an external ground potential. [Means for solving the problem]

[0010] The cable with an abnormality detection function disclosed herein comprises a target electric wire having an electric wire conductor and an electric wire coating covering the outer periphery of the electric wire conductor, and a detection wire having a detection wire conductor and a detection wire coating covering the outer periphery of the detection wire conductor, wherein the detection wire conductor has a shorter flexural life overall than the electric wire conductor, and the detection wire conductor includes, as element wires, an inner element wire and an outer element wire having a shorter flexural life than the inner element wire, each of the inner element wires being configured as a bare wire with a conductive material exposed, and the outer element wire is arranged on the outer periphery of the group of inner element wires insulated from the group of inner element wires. [Effects of the Invention]

[0011] The cable with abnormality sign detection function according to the present disclosure can detect signs of an electrical wire breakage by inputting an electrical signal without using an external ground potential. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a cross-sectional view showing the configuration of a cable with an abnormality sign detection function according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view showing the configuration of a detection line included in the cable with anomaly sign detection function according to the first embodiment. [Figure 3] FIG. 3 is a cross-sectional view showing the configuration of a detection line included in a cable with anomaly sign detection function according to a second embodiment of the present disclosure. [Figure 4] FIG. 4 is a cross-sectional view showing the configuration of a detection line included in a cable with anomaly sign detection function according to a third embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0013] [Description of the embodiments of the present disclosure] First, an embodiment of the present disclosure will be described. A cable with an abnormality detection function according to an embodiment of the present disclosure comprises a target electric wire having an electric wire conductor and an electric wire coating covering the outer periphery of the electric wire conductor, and a detection wire having a detection wire conductor and a detection wire coating covering the outer periphery of the detection wire conductor, wherein the detection wire conductor has a shorter flexural life overall than the electric wire conductor, and the detection wire conductor includes, as element wires, an inner element wire and an outer element wire having a shorter flexural life than the inner element wire, each of the inner element wires being configured as a bare wire with a conductive material exposed, and the outer element wire is arranged on the outer periphery of the group of inner element wires insulated from the group of inner element wires.

[0014] The cable with anomaly detection capability includes a detection line having a detection line conductor with a shorter flex life than the conductor of the target electric wire. Therefore, when the cable with anomaly detection capability is repeatedly subjected to loads due to bending or vibration, the wires included in the detection line conductor will break in a shorter time than the conductor of the target electric wire. When a break occurs in the wire included in the detection line, the break can be detected by electrical measurements such as measuring the characteristic impedance, making it possible to detect the occurrence of a break in the target electric wire before a break actually occurs in the target electric wire.

[0015] During this electrical measurement, the group of inner wires of the two types of wires included in the detection wire conductor is used as a ground wire. Electrical signals are input to the outer wires based on the ground potential determined by the ground wire. Because the outer wires have a shorter flex life than the inner wires and are arranged around the inner wires, the outer wires tend to break before the inner wires when repeated loads due to bending or vibration are applied to the detection wire. Therefore, using the group of inner wires as a ground wire enables stable detection of breaks in the outer wires through electrical measurement and sensitive detection of signs of breakage in the target electric wire. Because the outer and inner wires form a common detection wire, detecting wire breaks through electrical measurement does not require connection to the ground potential of the entire equipment equipped with the anomaly detection function or the installation of a separate ground wire outside the anomaly detection function cable. This allows for stable electrical measurement while avoiding the effects of noise from the ground potential of the entire equipment and the increased space and mass required for installing a separate ground wire. Furthermore, since the inner strand is configured as a bare wire with the conductive material exposed, the inner strand provides a particularly stable ground potential.

[0016] In addition, in this cable with anomaly detection functionality, instead of using the group of inner wires of the detection conductor as a ground wire, if a different ground potential, such as the ground potential of the entire device or a separately provided ground wire, is used, the inner wires can also be used to detect signs of a disconnection in the target electric wire. The inner wires have a longer flex life than the outer wires, and because they are located inside the outer wires, they are less likely to break than the outer wires. However, if loads due to bending or vibration are repeatedly applied to the detection conductor, there is a possibility that the inner wires will break after the outer wire breaks. Therefore, by performing electrical measurements on the group of outer wires and inner wires using a different ground potential as a reference, and detecting a break in the outer wire and a subsequent break in the inner wire, it is possible to detect signs of a disconnection in the electric wire conductor of the target electric wire in stages.

[0017] Here, each of the outer wires may have an insulating layer around the outer periphery of a conductive material, thereby insulating them from one another. In this case, the insulating layer around each outer wire ensures insulation between the group of outer wires and the inner wires. At the same time, since the outer wires are insulated from one another, even if the outer wires break one by one or several at a time depending on the magnitude of the load applied to the cable with anomaly detection function, it is unlikely that the broken wires will come into contact with the unbroken wires, thereby reestablishing continuity at the break point. Therefore, changes in measured values ​​in electrical measurements, such as characteristic impedance, occur sensitively in response to the gradual breakage of the outer wires. By detecting such gradual breakage through electrical measurement, it is possible to distinguish and detect the degree of imminent signs of a breakage in the target electric wire.

[0018] Alternatively, the outer periphery of the group of inner wires may be surrounded by an insulating material, and the outer wire may be disposed on the outer periphery of the insulating material. In this case, insulation between the inner wires and the outer wires can be ensured with a simple configuration in which the outer periphery of the group of inner wires is simply covered with a continuous insulating material.

[0019] Alternatively, the outer wires may be divided into multiple groups, each of which may be surrounded by an insulating material. In this case, the insulating material surrounding each of the multiple groups of outer wires insulates the outer wires from each other and from the inner wires. Dividing the outer wires into multiple groups and insulating each group from each other makes it less likely that a break in one or some of the groups will cause electrical continuity to be reestablished at the break due to contact with wires in other groups. Therefore, changes in electrical measurements, such as characteristic impedance, are more sensitive to breaks in groups of outer wires. In other words, if all of the wires in a group break, the break is clearly detected as a change in the electrical characteristics of the outer wire. By detecting gradual breaks in the outer wires in groups, it is possible to accurately determine and detect the degree of impending disconnection of the target electric wire.

[0020] The outer wire may be composed of multiple types of wires having different flex lifespans, and the multiple types of wires may be insulated from one another. In this case, the outer wires of the multiple types of outer wires will break in order, starting with the wires with the shortest flex lifespan. In electrical measurements of the outer wires as a whole, a gradual change occurs, whereby changes due to breakage of the outer wires with the shortest flex lifespans occur first, followed by changes due to breakage of the outer wires with the longest flex lifespans. By detecting this gradual change, it becomes possible to determine in detail the degree of load applied to the cable with anomaly detection function and the degree of imminent sign of a break in the target electric wire.

[0021] Among the multiple types of wires constituting the outer wire, those with shorter flex lifespans are preferably arranged closer to the outer periphery of the detection conductor. The wires closer to the outer periphery of the detection conductor are subjected to a greater load due to bending, making them more susceptible to breakage. Therefore, by arranging the outer wires with shorter flex lifespans closer to the outer periphery, the difference in susceptibility to breakage due to differences in flex lifespans is amplified by the effect of arrangement, and the difference in the time to breakage for each wire type among the outer wires becomes greater. This makes it easier to clearly identify the degree of imminent sign of a breakage in the target electric wire.

[0022] The inner wire and the outer wire may have different flex lifespans due to differences in at least one of the constituent material and wire diameter, which makes it possible to easily differentiate the flex lifespans of the inner wire and the outer wire.

[0023] The cable with anomaly sign detection function may include a power line and a communication line as the target electric wires, in which case signs of disconnection in both the power line and the communication line can be detected using a common detection line.

[0024] [Details of the embodiments of the present disclosure] Hereinafter, a cable with an abnormality sign detection function according to an embodiment of the present disclosure will be described in detail with reference to the drawings. The cable with an abnormality sign detection function according to an embodiment of the present disclosure is a cable that can detect signs of damage occurring in target electric wires included in the cable.

[0025] <Cable with abnormality sign detection function according to the first embodiment> (1) Configuration of cable with anomaly detection function First, a cable with anomaly sign detection function according to a first embodiment of the present disclosure (hereinafter, sometimes simply referred to as a cable) will be described. Fig. 1 shows the configuration of a cable with anomaly sign detection function 1 according to the first embodiment of the present disclosure in a cross-sectional view cut perpendicular to the axial direction. The cable with anomaly sign detection function 1 includes a target electric wire 2 (2A to 2D), a detection wire 3, a tape layer 4, and a sheath 5. Fig. 2 shows a cross section of the detection wire 3.

[0026] The target electric wires 2 are electric wires that perform functions required in devices, such as power supply, voltage application, and communication, and are the electric wires in the cable 1 that should be detected for signs of damage. The number of target electric wires 2 is not particularly specified and can be one or more. Each target electric wire 2 has an electric wire conductor 21 (21A-21D) configured as a conductor wire and an electric wire coating 22 configured of an insulating material that coats the outer periphery of the electric wire conductor 21. In the illustrated embodiment, the cable 1 includes four target electric wires 2A-2D. Of these four, two are power wires 2A and 2B. The other two are communication wires 2C and 2D, which have a smaller conductor cross-sectional area than the power wires 2A and 2B and are twisted together to form a twisted pair. In the figure, the outer edge of the twisted pair is indicated by a dashed line. This type of composite cable including power wires 2A and 2B and communication wires 2C and 2D is used for electric brakes in automobiles, etc.

[0027] As will be described later, the detection wire 3 is an electric wire that detects the occurrence of a sign of a disconnection in the target electric wire 2 by breaking itself. The detection wire 3 includes a detection wire conductor 31 configured as a conductor wire and a detection wire coating 32 configured of an insulating material and coating the outer periphery of the detection wire conductor 31. The number of detection wires 3 included in the cable 1 is not particularly limited and may be one or more. The following mainly describes an embodiment using only one detection wire 3, but multiple detection wires 3 differing in material, wire diameter, number, etc., of the wires constituting the detection wire conductor 31 may also be provided. From the viewpoint of ensuring insulation of the detection wire conductor 31, the detection wire coating 32 is preferably provided as a separate member from the detection wire conductor 31 to coat the entire outer periphery of the detection wire conductor 31. However, as will be described later, if an insulating layer 3c or a divided insulating layer 3e is provided on the outer periphery of the outer wire 3b constituting the outer periphery of the detection wire conductor 31, these insulating layers 3c and 3e may also serve as the detection wire coating.

[0028] The flex life of the detection line conductor 31 is shorter than that of the wire conductor 21 of the target electric wire 2. In this specification, the flex life of a conductor or element wire refers to the period until breakage occurs when bent, and can be evaluated as the number of flexes until breakage occurs when repeatedly bent at a predetermined angle. The greater the number of flexes, the longer the flex life (higher flex resistance). As will be explained later, the detection line conductor 31 includes multiple types of element wires, but the flex life of the detection line conductor 31 as a whole, i.e., the flex life of all the element wires combined, is shorter than that of the wire conductor 21 of the target electric wire 2. Furthermore, when the cable 1 includes multiple target electric wires 2, the flex life of the detection line conductor 31 is shorter than that of each of the wire conductors 21 of those multiple target electric wires 2. When power lines 2A, 2B and communication lines 2C, 2D are included in a cable 1, the power lines 2A, 2B, which have a larger conductor cross-sectional area than the communication lines 2C, 2D, generally have a shorter flex life, and the detection line conductor 31 has an even shorter flex life than the power lines 2A, 2B.

[0029] The following examples of means for providing a difference in the flex life of the conductors 21, 31 between the target electric wire 2 and the detection wire 3 can be given. For example, if the conductor cross-sectional area is the same, the greater the number of strands constituting the stranded conductor, the longer the flex life. Furthermore, the thinner the strands constituting the conductor, the longer the flex life. Furthermore, if the conductive material constituting the conductor exhibits high flex resistance as a material property, for example, if it has a large Young's modulus, a high modulus of rigidity, and high bending strength, the flex life of the conductor will be longer. Furthermore, as described in Patent Document 1, the shorter the twist pitch of the strands in the conductor, the longer the flex life of the conductor. In the illustrated embodiment, the conductor cross-sectional area of ​​the detection wire conductor 31 is smaller than that of each target electric wire 2, and the strands constituting each detection wire 3 are thinner than the strands constituting each target electric wire 2.

[0030] In the cable 1, all of the target electric wires 2 and detection wires 3 are bundled together to form a group of electric wires G. In the group of electric wires G, the relative arrangement of each target electric wire 2 and detection wire 3 is not particularly limited, but it is preferable to place the detection wire 3 in the center and arrange multiple target electric wires 2 around the outer periphery of the detection wire 3. In this case, if multiple detection wires 3 are provided, it is advisable to arrange these multiple detection wires 3 together in the center. The detection wires 3 and target electric wires 2 may simply be bundled together as an electric wire bundle, but it is preferable to place the target electric wires 2 around the outer periphery of the detection wire 3 with the detection wire 3 at the center and twist them together. In this case, the central detection wire 3 will also be twisted.

[0031] A tape layer 4 is provided on the outer periphery of the electric wire group G. The tape layer 4 serves to separate each of the target electric wires 2 and the detection wire 3 constituting the electric wire group G from the sheath 5. The form and material of the tape layer 4 are not particularly limited, but a suitable example is a form in which a tape body made of an insulating material such as paper or resin is spirally wound around the outer periphery of the electric wire group G. The tape layer 4 is in close contact with the electric wire group G. In other words, it is in contact with the outer periphery of the electric wires 2A to 2D, 3 constituting the electric wire group G that face the outermost periphery of the electric wire group G (here, the target electric wires 2A, 2B, 2D).

[0032] The sheath 5 is an extrusion molded body of an insulating material whose main component is a polymer material, and surrounds the outer periphery of the tape layer 4 to form the outermost periphery of the entire cable 1. The sheath 5 is in close contact with the outer periphery of the tape layer 4. In other words, it is preferable that the sheath 5 is in contact with the tape layer 4 over the entire outer periphery of the tape layer 4, with no gaps formed between the sheath 5 and the tape layer 4, except for unavoidable gaps. The sheath 5 may be composed of one layer or multiple layers. In the illustrated embodiment, however, it is composed of two layers, an outer layer 51 and an inner layer 52, with the outer layer 51 being made of a material with better mechanical properties, such as abrasion resistance, than the inner layer 52. In the cable 1, the tape layer 4 may be omitted, and the sheath 5 may be formed as an extrusion molded body that is in direct contact with the outer periphery of the group of electric wires G. The sheath 5 is formed as an extrusion molded body and is adhered to the outer periphery of the group of electric wires G via an appropriate tape layer 4, so that the positional relationship between the target electric wire 2 and the detection wire 3 is less likely to shift relative to each other, and signs of a break in the target electric wire 2 can be accurately detected by the detection wire 3 with sensitivity that is not dependent on the position or time.

[0033] (2) Configuration of the detection line conductor Next, we will explain the detection line conductor 31 that constitutes the detection line 3 included in the cable with anomaly sign detection function 1. The detection line conductor 31 is configured as an assembly of multiple strands (single wires made of conductive wire material), but it is not all made of the same strands; it includes multiple inner strands 3a and multiple outer strands 3b. The outer strands 3b have a shorter flex life than the inner strands 3a.

[0034] In the cable 1 according to this embodiment, a plurality of inner wires 3a are gathered into one group at the center. A plurality of outer wires 3b are arranged around the outer periphery of this group of inner wires 3a. In the illustrated embodiment, the outer wire 3b is arranged around the outer periphery of the group of inner wires 3a. It is preferable that no other wires or members are interposed between the inner wire 3a and the outer wire 3b, except for the insulating layer 3c on the outer periphery of the outer wire 3b. In the detection line conductor 31, it is preferable that the entire assembly of the plurality of inner wires 3a and the plurality of outer wires 3b is twisted.

[0035] As described above, the outer wire 3b has a shorter flex life than the inner wire 3a. The outer wire 3b and the inner wire 3a may have different flex lifes due to differences in at least one of the constituent material and wire diameter. The difference in constituent material may be such that the inner wire 3a is made of a material that exhibits higher flex resistance in terms of material properties, such as a higher Young's modulus, a higher modulus of rigidity, and higher bending strength, than the outer wire 3b. The difference in wire diameter may be such that the inner wire 3a has a smaller wire diameter than the outer wire 3b. Preferably, the inner wire 3a and the outer wire 3b differ from each other at least in constituent material, with the inner wire 3a being made of a material that exhibits higher flex resistance. For example, suitable examples include a configuration in which copper (soft copper) is used for the outer wire 3b and a copper alloy is used for the inner wire 3a; a configuration in which aluminum is used for the outer wire 3b and an aluminum alloy is used for the inner wire 3a; and a configuration in which a copper alloy or aluminum alloy with relatively low bending resistance is used for the outer wire 3b and a different copper alloy or aluminum alloy with higher bending resistance is used for the inner wire 3a.

[0036] Each inner wire 3a is configured as a bare wire (including a plated metal wire; the same applies throughout this specification). That is, each inner wire 3a does not have an insulating layer on its outer periphery, and the conductive material that makes up the inner wire 3a is directly exposed. In the detection line conductor 31, a plurality of inner wires 3a, each configured as a bare wire, are gathered together to form a group, and electrical continuity is formed between the plurality of inner wires 3a.

[0037] As long as the outer wires 3b are insulated from the group of inner wires 3a, each may be either a bare wire or have an insulating layer on its outer periphery. However, in this embodiment, each outer wire 3b has its own insulating layer 3c. That is, the outer periphery of each outer wire 3b made of conductive material is individually coated with an insulating layer 3c. The specific type and thickness of the insulating layer 3c are not particularly limited, but it is preferably an enamel coating layer. The insulating layer 3c provided on the outer periphery of this outer wire 3b insulates the outer wire 3b from the group of inner wires 3a. At the same time, the insulating layer 3c also insulates each outer wire 3b from each other.

[0038] (3) Method of detecting disconnection When the cable 1 described above is mounted in equipment or the like and is subjected to repeated bending and vibration during use, metal fatigue may accumulate in the wire conductor 21 that constitutes the target electric wire 2, potentially leading to a break. If a break occurs in the target electric wire 2, the target electric wire 2 may no longer be able to perform its functions of power supply, communication, etc., and the equipment in which the cable 1 is mounted may no longer be able to continue to function normally. Furthermore, a break in the target electric wire 2 may cause malfunctions or other problems in the equipment.

[0039] However, the cable 1 according to this embodiment includes not only a target electric wire 2 that performs a predetermined function in an apparatus or the like, but also a detection wire 3 having a detection wire conductor 31 with a shorter flex life than the electric wire conductor 21 of the target electric wire 2. If the cable 1 is subjected to repeated bending and vibration, the detection wire conductor 31, which has a shorter flex life, will break before the electric wire conductor 21. Breaking of the detection wire conductor 31 indicates that the target electric wire 2 is also subjected to load due to bending and vibration, accumulating metal fatigue in the electric wire conductor 21. If the load continues to be applied, the electric wire conductor 21 of the target electric wire 2 may also break. Breaking of the detection wire conductor 31 can be detected by electrical measurements such as measuring characteristic impedance. Here, breakage of the detection wire conductor 31 refers to breakage of at least one of the wires (the outer wire 3b and the inner wire 3a) that make up the detection wire conductor 31.

[0040] In this way, by detecting breakage of the detection wire conductor 31, which has a short bending life, it is possible to detect signs of a breakage in the wire conductor 21 of the target electric wire 2 before a breakage actually occurs in the target electric wire 2. If measures such as replacing the target electric wire 2 with a new one are taken at the stage when a sign of a breakage in the target electric wire 2 is detected, it is possible to prevent problems caused by a breakage in the target electric wire 2. In this specification, a breakage in the wire conductor 21 of the target electric wire 2 may be simply referred to as a breakage of the target electric wire 2.

[0041] In the cable 1 according to this embodiment, one inspection method for detecting signs of disconnection in the target electric wire 2 using the detection wire 3 is to use the group of inner wires 3a as a ground potential, input an electrical signal to the outer wires 3b, and measure the characteristic impedance (or other electrical parameters obtained by electrical measurement; the same applies below). In this case, when measuring the characteristic impedance, a reference potential is set to the group of inner wires 3a, and an inspection signal containing an AC component is input to the group of outer wires 3b. Then, a response signal is detected by a reflection method or a transmission method, preferably a reflection method.

[0042] If a break occurs in the outer wire 3b midway through the detection line conductor 31, a discontinuous change occurs in the response signal because an electrical signal is reflected at the break. Therefore, if a change in the measured characteristic impedance exceeds a reference value, it can be determined that a break has occurred in the outer wire 3b and that a break is imminent in the wire conductor 21 of the target electric wire 2. When a break occurs in the outer wire 3b of the simple, straight detection line conductor 31, the characteristic impedance value typically increases. The reference value of the characteristic impedance can be determined in advance as a threshold value for the amount of change that should be considered to be due to a break in the outer wire 3b, based on actual measurement results when no break occurs in the outer wire 3b. Note that a change in the characteristic impedance can also occur due to damage to the outer wire 3b that does not result in a break. While this specification treats a change in characteristic impedance due to a break as a representative example, damage to the outer wire 3b other than a break can also be used to detect a break in the target electric wire 2 via a change in characteristic impedance.

[0043] Furthermore, by using the time domain or frequency domain method to measure the characteristic impedance, it is possible to apply a load along the axial direction of the cable 1 and identify the location of a break in the outer wire 3b of the detection line conductor 31. In the time domain method, a pulsed electrical signal is input to the group of outer wires 3b, and the time at which a change in characteristic impedance appears is converted into a position along the axial direction of the cable 1, thereby determining the location of the break in the outer wire 3b. In the frequency domain method, an electrical signal containing multiple frequency components is input to the group of outer wires 3b, and the response signal is Fourier transformed to convert the frequency information into position information on the cable 1. It is preferable to measure the characteristic impedance of the detection line 3 continuously or intermittently while the cable 1 is in use. This allows for early detection of a possible break in the wire conductor 21 of the target electric wire 2 and notification to users of the equipment in which the cable 1 is installed. Alternatively, the characteristic impedance of the detection line 3 can be measured at predetermined intervals, such as during periodic inspections of equipment in which the cable 1 is installed.

[0044] In the detection line conductor 31 of the cable 1 according to this embodiment, the outer wire 3b has a shorter flex life than the inner wire 3a. Therefore, when the detection line conductor 31 is repeatedly subjected to loads due to bending or vibration of the cable 1, the outer wire 3b breaks before the inner wire 3a. Furthermore, even if the elements are the same, the outermost wire of the conductor receives a larger load when the conductor is bent, making it more likely to break even after a small number of bends. This is because the outermost wire of the conductor is the wire that can be bent with the smallest radius of curvature on the inside of the bent shape. In the detection line conductor 31 of the cable 1 according to this embodiment, the outer wire 3b is arranged on the outer periphery of the group of inner wires 3a. This arrangement amplifies the difference in flex life between the inner wires 3a and 3b, which is due to the characteristics of the wires themselves, and further accentuates the tendency of the outer wire 3b to break after fewer bends than the inner wires 3a.

[0045] As described above, even when the cable 1 according to this embodiment is subjected to loads caused by bending or vibration, the inner wires 3a of the detection conductor 31 are less likely to break than the outer wires 3b. Even if some of the outer wires 3b break first when a load is repeatedly applied to the detection conductor 31, as long as the inner wires 3a do not break entirely, the inner wires 3a can be stably used as a ground wire and as a reference potential for measuring the characteristic impedance of the outer wires 3b. On the other hand, the outer wires 3b break in a relatively short period of time when subjected to repeated loads caused by bending or vibration. Therefore, the change in characteristic impedance associated with the breakage can sensitively indicate signs of a break in the target electric wire 2 constituting the cable 1. Because the group of inner wires 3a and the outer wires 3b are insulated from each other, the inner wires 3a functioning as a ground wire and the outer wires 3b functioning as a means for detecting signs of a breakage due to breakage can coexist concentrically within the single detection conductor 31.

[0046] By using the group of inner strands 3a included in the detection line conductor 31 as a ground line, there is no need to use an external ground potential, such as the ground potential of the entire device in which the cable 1 is installed, such as an automobile, or a dedicated ground line provided separately from the cable 1, as the reference potential and return path for the electrical signal used to detect signs of a disconnection. The ground potential of the entire device, such as an automobile, is often connected to various devices that make up the device, which is prone to generating noise from these devices, thereby reducing the accuracy of the characteristic impedance measurement in the detection line 3. Furthermore, providing a dedicated ground line separate from the cable 1 requires space for the installation, which can lead to a more complex internal configuration and increased mass of the device.

[0047] Furthermore, in the detection line conductor 31 of the cable 1 according to this embodiment, the inner wires 3a are configured as bare wires, and the inner wires 3a are grouped together at the center of the detection line conductor 31. In other words, the inner wires 3a behave electrically as a single conductor as a whole. Therefore, when measuring the characteristic impedance of the outer wires 3b, the inner wires 3a function as a stable ground potential, allowing for stable and continuous measurement of the characteristic impedance with little noise. As a result, signs of a wire break can be detected with high accuracy. If each of the inner wires 3a were covered with an insulating layer like the outer wires 3b, the ground potential would be unstable, which could hinder accurate characteristic impedance measurement.

[0048] On the other hand, because each outer wire 3b is covered with an insulating layer 3c, it is possible to detect signs of wire breakage in a stepwise manner. When the detection line conductor 31 is subjected to load due to repeated bending or vibration, it is rare for all outer wires 3b to break at once unless an extremely large load is applied. In most cases, the outer wires 3b break one by one, or several by several, and over a certain period of time, the number of broken outer wires 3b gradually increases. When measuring the characteristic impedance of multiple outer wires 3b as a whole, if a break occurs in an outer wire 3b, the continuity of conduction in that outer wire 3b will be interrupted at the break point, and the measured value of the characteristic impedance should change depending on the number of broken wires. However, if the outer wires 3b do not have an insulating layer 3c and are mutually conductive, even if one outer wire 3b breaks, the adjacent unbroken outer wires 3b will come into contact with the broken outer wire 3b and bridge the break, maintaining continuity in the broken outer wire 3b (chattering; reestablishment of continuity). This would result in no change in the characteristic impedance of the outer wire 3b. Or, even if a change does occur, the amount of change may be small or only gradual.

[0049] In contrast, in this embodiment, the outer wires 3b are insulated from each other by the insulating layer 3c. Therefore, even if one outer wire 3b breaks, the outer wire 3b is insulated from the surrounding outer wires 3b, so that the continuity of the outer wire 3b, interrupted at the break point, is stably maintained. As a result, the breakage of the outer wire 3b has a large and clear effect on the measured value of the characteristic impedance of the outer wire 3b. In other words, if the outer wires 3b break stepwise as the load applied to the cable 1 due to bending or the like accumulates, the characteristic impedance of the outer wire 3b will undergo a clear step-like change. That is, the value will change from a stable state to a sudden change (usually an increase), and then return to a stable state after the change. By detecting this step-like change in characteristic impedance, it is possible to detect that the outer wires 3b have broken in stages, and furthermore, it is possible to estimate the number of broken outer wires 3b from the number and magnitude of these step-like changes. The progression of step-like breaks in the outer wires 3b means that the cable 1 as a whole is being subjected to a cumulative load due to repeated bending, etc. In other words, it means that signs of a wire breakage in the target wire 2 caused by metal fatigue are progressing.

[0050] As described above, when a change of a reference value or more occurs in the characteristic impedance measured for the entire outer wire 3b, it can be determined that there is a sign of a disconnection in the target electric wire 2. In addition, by detecting gradual breakage of the outer wire 3b from a step-like change in characteristic impedance, it is possible to determine the urgency of the sign of a disconnection in the target electric wire 2 (how much additional load is required to actually cause a disconnection). This makes it possible to take measures such as issuing an alarm according to the urgency in the device in which the cable 1 is installed.

[0051] So far, we have described a configuration in which the inner wire 3a of the detection wire 3 is used as a ground wire to inspect the target electric wire 2 for signs of disconnection. However, in the cable 1 according to this embodiment, as another inspection method for detecting signs of disconnection in the target electric wire 2 using the detection wire 3, a configuration in which the inner wire 3a is also the target for measuring the characteristic impedance can be used. In this case, the ground potential is the ground potential of the entire device in which the cable 1 is installed, or a ground wire separately provided outside the cable 1, and the characteristic impedance of the entire detection wire conductor 31 including the outer wire 3b and the inner wire 3a is measured using the ground potential. As described above, the outer wire 3b, which has a short flex life, breaks first when the application of load due to bending, etc., has not accumulated much. After that, the inner wire 3a, which has a long flex life, breaks after the application of load has accumulated further. This gradual breakage of the outer wire 3b and the inner wire 3a also causes a gradual change in the characteristic impedance. By detecting this gradual change in characteristic impedance, it becomes possible to determine the imminent risk of a disconnection in the target electric wire 2 due to the application of a load over a wide range that cannot be covered by the gradual breakage of the outer wires 3b that are insulated from each other. This inspection method may be adopted when the noise in the ground potential of the entire device is mild or when the increase in required space due to the provision of a separate independent ground wire is not a problem.

[0052] (4) Transformation The above describes a configuration in which one type of outer wire 3b is used, the type having a shorter flex life than the inner wire 3a. However, it is also possible to use multiple outer wires 3b, each with a shorter flex life than the inner wire 3a but with different flex lifes. The outer wires 3b may have different flex lifes, as long as they differ in at least one of their constituent materials and wire diameters. By using multiple types of outer wires 3b with different flex lifes, the outer wires 3b with shorter flex lifes will break earlier. Therefore, the change in the characteristic impedance of the outer wires 3b as a whole, corresponding to the gradual breakage of the outer wires 3b, will occur more clearly and over a wider range of load application levels. In particular, by arranging the outer wires 3b in multiple layers around the group of inner wires 3a and arranging the outer wires 3b with shorter flex lifes closer to the outer periphery of the detection line conductor 31, the difference in flex life among the multiple types of outer wires 3b can be further amplified by the effect of the arrangement. Furthermore, when the cable 1 includes multiple target electric wires 2 with different flexural lives, such as power lines 2A, 2B and communication lines 2C, 2D, signs of disconnection of target electric wires 2 with short flexural lives, such as power lines 2A, 2B, can be detected by breakage of the outer wire 3b with the shortest flexural life among the multiple types of outer wires 3b, and signs of disconnection of target electric wires 2 with long flexural lives, such as communication lines 2C, 2D, can be detected by breakage of the outer wire 3b with the longest flexural life among the multiple types of outer wires 3b.

[0053] Furthermore, in the above description, only one detection wire 3 is provided in one cable with anomaly sign detection function 1, but multiple detection wires 3 may be provided. When multiple detection wires 3 are provided, the detection wire conductors 31 of those detection wires 3 may be made of wires 3a, 3b, particularly the outer wire 3b, with different flex lifespans, thereby making it possible to more clearly determine the imminent sign of a wire breakage in the target electric wire 2. The more breakage is detected in the detection wire conductor 31 that includes a wire with a long flex life, the more fatigue of the electric wire conductor 21 has progressed, and it can be determined that the sign of a wire breakage is imminent. Furthermore, when the cable 1 includes multiple target electric wires 2 with different flexural lives, such as power lines 2A, 2B and communication lines 2C, 2D, signs of a break in the target electric wires 2 with a short flexural life, such as the power lines 2A, 2B, can be detected by the breakage of a detection line conductor 31 that includes a wire with a short flexural life among the multiple detection line conductors 31, and signs of a break in the target electric wires 2 with a long flexural life, such as the communication lines 2C, 2D, can be detected by the breakage of a detection line conductor 31 that includes a wire with a long flexural life among the multiple detection line conductors 31.

[0054] In the cable 1 with anomaly sign detection function according to the first embodiment of the present disclosure and its modified example described above, the outer wires 3b constituting the detection conductor 31 are individually insulated by the insulating layer 3c. By insulating the outer wires 3b from each other in this way, it is possible to detect changes in characteristic impedance due to gradual breakage of the outer wires 3b and determine the urgency of a breakage sign in the target electric wire 2. However, if it is not necessary to detect breakage of each of the outer wires 3b in this way, it is not necessary to insulate the outer wires 3b individually. As long as each of the inner wires 3a, which are wires with a relatively long flex life, is configured as a bare wire with an exposed conductive material, and the outer wires 3b, which are wires with a relatively short flex life, are arranged around the group of inner wires 3a in a state insulated from the group of inner wires 3a, the inner wires 3a can be used as ground wires, and signs of a wire breakage in the target electric wire 2 can be detected using the change in characteristic impedance due to the breakage of the outer wire 3b as an indicator without using an external ground potential. Furthermore, if an external ground potential is used as appropriate, the urgency of the signs of a wire breakage in the target electric wire 2 can be determined in at least two stages by taking advantage of the fact that the change in characteristic impedance occurs in stages due to the breakage of the outer wire 3b and the breakage of the inner wire 3a.

[0055] Such configurations in which the outer wires 3b are not individually insulated will be described below as cables with anomaly sign detection function according to second and third embodiments of the present disclosure. Although the second and third embodiments below do not preclude the formation of an insulating layer 3c on the outer periphery of each outer wire 3b, from the viewpoint of structural simplicity, it is preferable not to provide such an insulating layer 3c. In the following description of the second and third embodiments, description of configurations common to the first embodiment described in detail above will be omitted.

[0056] <Cable with abnormality sign detection function according to the second embodiment> The cable with anomaly sign detection function according to the second embodiment of the present disclosure has a configuration similar to that of the cable 1 according to the first embodiment shown in Fig. 1. However, the configuration of the detection line conductor 31' constituting the detection line 3' differs from that of the detection line conductor 31 of the first embodiment. Fig. 3 shows a cross section of the detection line 3' included in the cable with anomaly sign detection function according to the second embodiment.

[0057] The detection wire conductor 31′ included in the detection wire 3′ of the second embodiment also has outer wires 3b with a relatively short flex life disposed around a group of inner wires 3a with a relatively long flex life. Here, both the inner wires 3a and the outer wires 3b are configured as bare wires with their conductive material exposed. In this embodiment, the outer periphery of the group of inner wires 3a gathered in the center of the detection wire conductor 31′ is surrounded by inner and outer insulating layers 3d made of an insulating material. The outer wires 3b are disposed around the outer periphery of the inner and outer insulating layers 3d, and the group of inner wires 3a and the outer wires 3b are insulated from each other by the inner and outer insulating layers 3d. The inner and outer insulating layers 3d may be formed in any form to cover the outer periphery of the group of inner wires 3a, and examples thereof include an extruded resin coating layer, an enamel coating layer, a layer wrapped around a sheet made of an insulating material such as paper or resin, or a layer covered with a tube made of such an insulating material.

[0058] When the detection conductor 31' is repeatedly subjected to bending and vibration due to bending of the entire cable, the outer wire 3b breaks earlier than the inner wire 3a due to its short bending life and its location on the outer periphery of the detection conductor 31'. By detecting the breakage of the outer wire 3b as a change in characteristic impedance, it is possible to detect the accumulation of fatigue in the electric wire conductor 21 of the target electric cable and the occurrence of signs of a wire breakage. When inspecting for signs of a wire breakage, the inner wire 3a may be used as a ground wire to measure the characteristic impedance of the outer wire 3b, or an external ground potential of the cable may be used to measure the characteristic impedance of the entire detection conductor 31', including the outer wire 3b and the inner wire 3a. In the former case, the use of an external ground potential can be eliminated. In the latter case, signs of a wire breakage can be detected in two stages by taking advantage of the fact that when loads due to repeated bending and vibration are applied, the outer wire 3b breaks first, followed by the inner wire 3a.

[0059] In this second embodiment, unlike the first embodiment, the outer wires 3b are not individually insulated. Therefore, even if the outer wires 3b break in stages, it is difficult to detect the staged breakage as a change in characteristic impedance. Therefore, it is difficult to use the staged breakage of the outer wires 3b to determine the imminent stage of a disconnection in the target electric wire. However, since there is no need to individually insulate the outer wires 3b and the configuration of the detection line conductor 31′ can be simplified, this embodiment is suitable for use in cases where it is not necessary to precisely determine the imminent stage of a disconnection. In this second embodiment, multiple types of wires having different flex lifes can be used as the outer wires 3b. In this case, multiple types of outer wires 3b can be arranged so that the outer wires 3b with shorter flex lifes are located closer to the outer periphery. Layers of insulating material similar to the inner and outer insulating layers 3d can be provided between the layers of the different types of outer wires 3b to maintain mutual insulation between the wire types.

[0060] <Cable with abnormality sign detection function according to the third embodiment> The cable with anomaly sign detection function according to the third embodiment of the present disclosure has the same overall configuration as the cable 1 according to the first embodiment shown in FIG. 1. However, the configuration of the detection line conductor 31" that constitutes the detection line 3" differs from the detection line conductors 31, 31' of the first and second embodiments. FIG. 4 shows a cross section of the detection line 3" included in the cable with anomaly sign detection function according to the third embodiment.

[0061] The detection wire conductor 31" included in the detection wire 3" of the third embodiment also has outer wires 3b with a relatively short flex life arranged around the outer periphery of a group of inner wires 3a with a relatively long flex life. Here, the inner wires 3a are configured as bare wires with the conductive material exposed. The outer wires 3b are also configured as bare wires with the conductive material exposed, but are divided into multiple groups g, and the outer periphery of each group g is surrounded by a divided insulating layer 3e made of an insulating material. The outer wires 3b constituting each group g surrounded by the divided insulating layer 3e are not insulated from each other, but between each group g, the outer wires 3b are insulated from each other by the divided insulating layer 3e. The outer wires 3b are arranged around the outer periphery of the group of inner wires 3a, with each group g being a unit that is surrounded and partitioned by the divided insulating layer 3e. The divided insulating layer 3e may be in any form that covers the outer periphery of each group g of the outer wire 3b, and examples include an extruded resin coating layer, an enamel coating layer, a layer wrapped around a sheet made of an insulating material such as paper or resin, or a layer covered with a tube made of such an insulating material.

[0062] When loads due to bending or vibration are repeatedly applied to the detection line conductor 31″ due to bending of the entire cable, etc., the outer wire 3b breaks earlier than the inner wire 3a due to its short bending life and its position on the outer periphery of the detection line conductor 31″. By detecting the breakage of the outer wire 3b as a change in characteristic impedance, it is possible to detect that fatigue has accumulated in the electric wire conductor of the target electric wire and that signs of a wire breakage are occurring. When inspecting for signs of a wire breakage, the inner wire 3a may be used as a ground wire and the characteristic impedance of the outer wire 3b may be measured, or an external ground potential of the cable may be used and the characteristic impedance of the entire detection line conductor 31″ including the outer wire 3b and the inner wire 3a may be measured. In the former case, the use of an external ground potential can be eliminated, and in the latter case, signs of a wire breakage can be detected in at least two stages by utilizing the fact that when loads due to repeated bending or vibration are applied, the outer wire 3b breaks first and then the inner wire 3a breaks.

[0063] In this third embodiment, unlike the first embodiment, the outer wires 3b are not individually insulated. Therefore, even if the outer wires 3b break in stages, it is difficult to detect the staged breakage as a change in the characteristic impedance for each outer wire. However, if the group g divided by the divided insulating layers 3e is used as a unit, breakage of the outer wires 3b can be detected in stages. In other words, if all of the outer wires 3b constituting a certain group g break, a clear change can occur in the characteristic impedance measured for the outer wires 3b as a whole, even if all of the outer wires 3b in other groups g have not yet broken. In this way, by detecting the change in characteristic impedance when it occurs in stages, it is possible to classify and detect the imminent sign of a wire breakage in the target electric wire into a number of stages corresponding to the number of groups g of the outer wires 3b (six stages when the illustrated detection wire 3″ is used).

[0064] In this third embodiment, it is not necessary to determine the imminent risk of a break in the target electric wire with a resolution sufficient to identify breaks in each individual outer wire 3b, but this embodiment can be suitably applied when a certain degree of accuracy is desired. In a situation where the cable is bent frequently in some directions rather than equally in all directions, a particularly large load is applied to the detection conductor 31" at a position corresponding to the inside of the bent shape. As a result, in a group g of outer wires 3b located at such a position, all of the outer wires 3b in the group are more likely to break than in other groups g. In such a case, by using the detection conductor 31" of the third embodiment, in which the outer wires 3b are insulated for each group g, it is possible to effectively perform step-by-step detection of signs of a break in the target electric wire due to bending or vibration.

[0065] Furthermore, outer wires 3b with different flexural lives may be used between groups. In this case, breakage of the outer wires 3b occurs preferentially in group g, which is made up of outer wires 3b with a short flexural life, and a change in characteristic impedance due to breakage of all outer wires 3b in the group is likely to occur. For example, when a common cable contains multiple target electric wires with different flex lifespans, such as the power lines 2A and 2B and the communication lines 2C and 2D shown in FIG. 1 , a configuration is conceivable in which the detection conductor 31″ includes a group g of outer wires 3b with a short flex lifespan that can suitably detect signs of wire breakage in target electric wires with a relatively short flex lifespan, such as the power lines 2A and 2B, and a group g of outer wires 3b with a long flex lifespan that can suitably detect signs of wire breakage in target electric wires with a long flex lifespan, such as the communication lines 2C and 2D. In this case, the gradual change in the characteristic impedance of the detection conductor 31″ corresponding to the breakage of the outer wires 3b of each group g makes it possible to distinguish and detect signs of wire breakage in each target electric wire with a different flex lifespan. In this case, it is even more preferable that the target electric wires to be detected for signs of wire breakage and the group g of outer wires 3b suitable for detecting signs of wire breakage in each target electric wire are arranged close to each other in the cable with anomaly sign detection function.

[0066] Although the embodiments of the present disclosure have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0067] 1 (with abnormality detection function) cable 2. Target wires 2A,2B power line 2C,2D communication line 21(21A~21D) Electrical Wire Conductor 22 Wire coating 3,3',3" detection line 31, 31', 31" Detection line conductor 32 Detection wire coating 3a Inner wire 3b Outer wire 3c Insulation layer 3D inner and outer insulation layers 3e Split insulation layer 4 tape layers 5 Sheath 51 Outer layer 52 Inner layer G wire group g group of outer strands

Claims

1. A target electric wire having an electric conductor and an electric wire coating that coats the outer periphery of the electric conductor; a detection wire having a detection wire conductor and a detection wire covering that covers an outer periphery of the detection wire conductor; The sensing wire conductor has a shorter bending life than the electric wire conductor as a whole, and The detection line conductor includes, as element wires, a plurality of inner element wires and a plurality of outer element wires each having a bending life shorter than that of the inner element wires, Each of the inner strands is configured as a bare wire with a conductive material exposed, and electrical continuity is formed between the plurality of inner strands, Each of the outer strands has an insulating layer around the outer periphery of a conductive material, and is insulated from each other; A cable with an abnormality sign detection function, in which the outer wire is arranged around the outer periphery of the group of inner wires, and the outer wire is insulated from the group of inner wires by the insulating layer.

2. A target electric wire having an electric conductor and an electric wire coating that coats the outer periphery of the electric conductor; a detection wire having a detection wire conductor and a detection wire covering that covers an outer periphery of the detection wire conductor; The sensing wire conductor has a shorter bending life than the electric wire conductor as a whole, and The detection line conductor includes, as element wires, a plurality of inner element wires and a plurality of outer element wires each having a bending life shorter than that of the inner element wires, Each of the inner strands is configured as a bare wire with a conductive material exposed, and electrical continuity is formed between the plurality of inner strands, Each of the outer strands is configured as a bare wire with an exposed conductive material, and is not insulated individually; The outer periphery of the group of inner strands is surrounded by an insulating material, the outer strand is disposed around the outer periphery of the insulating material, A cable with an abnormality sign detection function, in which the outer wire is insulated from the group of inner wires by the insulating material.

3. 3. The cable with anomaly sign detection function according to claim 1, wherein the outer wire is composed of a plurality of types of wires having different flexural lives, and the plurality of types of wires are insulated from each other.

4. 4. The cable with anomaly sign detection function according to claim 3, wherein among the plurality of types of wires constituting the outer wire, wires with shorter flex lifespans are arranged closer to the outer periphery of the detection line conductor.

5. 5. The cable with anomaly sign detection function according to claim 1, wherein the inner wire and the outer wire have different flex lifespans due to differences in at least one of the constituent material and wire diameter.

6. The cable with anomaly sign detection function according to claim 1 , wherein the target electric wires include a power line and a communication line.

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