Method and device for inspecting a multi-core cable

Abstract

To provide a method for inspecting a multicore cable, capable of suppressing the influence of cross talk and accurately specifying a correspondence between the ends of electric insulated wires.SOLUTION: A method for inspecting a multicore cable, capable of specifying a correspondence between the ends of electric insulated wires 3 exposed from both ends of a multicore cable 2 comprises: inputting an inspection signal into the end of an electric insulated wire 3 to be inspected in the ends of the electric insulated wires 3 exposed to one end of the multicore cable 2 by capacitive coupling; inputting first and second signals different from the inspection signal into the ends of two electric insulated wires 3 except the electric insulated wire 3 to be inspected by capacitive coupling, respectively; measuring the voltage of the output signal outputted by capacitive coupling from each end of the electric insulated wires 3 exposed to the other end of the multicore cable 2; and specifying an end on the other side of the electric insulated wire 3 to be inspected on the basis of the measured voltage. At this time, the amplitude of a signal obtained by summing the inspection signal and the first and second signals is smaller than that of the inspection signal.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a method and an apparatus for inspecting a multi-core cable, and more particularly to an inspection method and an inspection apparatus for identifying the corresponding relationship between both ends of each of a plurality of coaxial lines in a multi-core cable. [Background technology]

[0002] There is known a multi-core cable in which many insulated electric wires, each having a conductor covered with an insulator, are collectively covered with a jacket. For example, a multi-core cable used as a medical probe cable is known to have many insulated electric wires (such as coaxial wires) numbering from tens to hundreds.

[0003] In such a multi-core cable having many insulated electric wires, it is difficult to identify each of the insulated electric wires by the color of the insulation. In addition, when the insulated electric wires are twisted together inside the multi-core cable, the positional relationship of the insulated electric wires is not constant. Therefore, when connecting a multi-core cable having many insulated electric wires to a connector, a circuit board, or the like, an inspection is required to identify the corresponding relationship between the ends of the insulated electric wires exposed from both ends of the multi-core cable.

[0004] As an inspection method for identifying the correspondence between the ends of insulated wires in a multi-core cable, for example, Patent Document 1 (JP 2019-120608 A) describes a method in which electrodes are placed on an insulator and an AC inspection signal is input to the conductor non-contact by capacitive coupling. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-120608 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in a method of inputting an AC inspection signal to a conductor in a non-contact manner, when many insulated electric wires are arranged at high density in a multi-core cable, crosstalk between the insulated electric wires becomes large, and it may be difficult to accurately identify the correspondence between the ends of the insulated electric wires. In other words, there is a problem that the accuracy of the inspection method and the inspection device for a multi-core cable is low.

[0007] Other objects and novel features will become apparent from the description of this specification and the accompanying drawings. [Means for solving the problem]

[0008] A brief outline of a representative embodiment of the present invention will be described below.

[0009] In one embodiment, a method for inspecting a multi-core cable is a method for identifying a correspondence between the ends of insulated electric wires exposed at both ends of the multi-core cable, in which an inspection signal is input by capacitive coupling to an end of an insulated electric wire to be inspected among the ends of the insulated electric wires exposed at one end of the multi-core cable, and a plurality of signals having amplitudes and phases different from the inspection signal or one of them is input by capacitive coupling to ends of a plurality of insulated electric wires other than the insulated electric wire to be inspected, and the voltage of an output signal output by capacitive coupling from each end of the insulated electric wire exposed at the other end of the multi-core cable is measured, and the other end of the insulated electric wire to be inspected is identified based on the measured voltage. Here, the amplitude of the signal obtained by adding the inspection signal and the other signal is smaller than the amplitude of the inspection signal.

[0010] The multi-core cable inspection device according to one embodiment is an inspection device for identifying the correspondence between the ends of the insulated electric wires exposed at both ends of the multi-core cable, and includes an inspection signal input means for inputting an inspection signal by capacitive coupling to an end of an insulated electric wire to be inspected among the ends of the insulated electric wires exposed at one end of the multi-core cable, a signal input means for inputting, by capacitive coupling, a plurality of signals having amplitudes and phases different from the inspection signal or one of them to the ends of a plurality of insulated electric wires other than the insulated electric wire to be inspected among the ends of the insulated electric wires exposed at one end of the multi-core cable, and a calculation device for measuring an output voltage output by capacitive coupling from each end of the insulated electric wires exposed at the other end of the multi-core cable and identifying the other end of the insulated electric wire to be inspected based on the output voltage. Here, the amplitude of the signal obtained by adding the inspection signal and the other signal is smaller than the amplitude of the inspection signal. Effect of the Invention

[0011] According to the present invention, the reliability of an inspection device for a multi-core cable can be improved. [Brief description of the drawings]

[0012] [Figure 1] 1 is an equivalent circuit diagram showing a configuration of a multi-core cable inspection device according to a first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view showing a schematic diagram of a multi-core cable. [Diagram 3] FIG. 2 is a cross-sectional view of an insulated electric wire constituting a multi-core cable. [Figure 4] 1 is a schematic diagram showing a configuration of a multi-core cable inspection device according to a first embodiment. [Diagram 5] 13 is a table showing the results of an inspection of the correspondence between ends of insulated wires carried out using an inspection device for a multi-core cable according to the comparative example and the first embodiment. [Figure 6] 13 is a perspective view showing a part of a multi-core cable inspection device according to a modified example of the first embodiment. FIG. [Figure 7] 11 is a schematic diagram showing a configuration of a multi-core cable inspection device according to a second embodiment. FIG. [Figure 8] 1 is an equivalent circuit diagram showing a configuration of a multi-core cable inspection device according to a comparative example. [Figure 9] 1 is a schematic diagram showing a configuration of a multi-core cable inspection device according to a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In all the drawings for explaining the embodiment, the same reference numerals are used for the members having the same functions, and the repeated explanations are omitted. In addition, in the embodiment, the explanations of the same or similar parts are not repeated as a rule, except when particularly necessary. In addition, the amplitude in this application means the amplitude of the voltage. In addition, in this application, the first auxiliary signal, the second auxiliary signal, etc. may each be called the auxiliary signal.

[0014] (Embodiment 1) <Structure of the multi-core cable inspection device according to the present embodiment> Fig. 1 is an equivalent circuit diagram showing the configuration of a multi-core cable inspection device used in the multi-core cable inspection method according to the present embodiment. Fig. 2 is a cross-sectional view showing a cross section perpendicular to the longitudinal direction (cross section along the short side direction) of a multi-core cable. Fig. 3 is a cross-sectional view showing a cross section perpendicular to the longitudinal direction (cross section along the short side direction) of one insulated electric wire out of a plurality of insulated electric wires constituting the multi-core cable. Fig. 4 is a schematic diagram showing the configuration of a multi-core cable inspection device used in the multi-core cable inspection method according to the present embodiment.

[0015] The multi-core cable inspection device 1 shown in Fig. 1 and Fig. 4 is used for an inspection to determine the correspondence between the ends of the insulated electric wires 3 exposed from both ends of one multi-core cable 2 shown in Fig. 2. The multi-core cable 2 is a bundle of n insulated electric wires 3 (for example, about 10 to 300 insulated electric wires 3). Here, n is an integer of 3 or more. In such a multi-core cable 2 having a large number of insulated electric wires 3, it is difficult to identify each of all the insulated electric wires 3 by the color of the insulator constituting the surface of the insulated electric wires 3. In addition, when the insulated electric wires 3 are twisted together inside the multi-core cable 2, the positional relationship of the insulated electric wires 3 is not constant. Therefore, when the multi-core cable 2 having a large number of insulated electric wires 3 is connected to a connector, a circuit board, or the like, an inspection is required to determine the correspondence between the ends of the insulated electric wires 3 exposed from both ends of the multi-core cable 2.

[0016] After identifying the correspondence between the ends of the insulated electric wires 3 in the multi-core cable 2, each of the insulated electric wires 3 at both ends of the multi-core cable 2 is connected to a connector or circuit board (e.g., an internal board of the sensor part of an ultrasonic probe) not shown in the figure according to the identified correspondence, thereby obtaining a multi-core cable assembly.

[0017] 2, the multi-core cable 2 has a number of coaxial wires 30 bundled together, and has an integrated shield 21 made of braid and a jacket 22 sequentially provided to surround the outer periphery of the number of coaxial wires 30. The number of insulated wires 3 in the multi-core cable 2 is not particularly limited, but the present embodiment is applicable to a multi-core cable 2 having three or more insulated wires 3. In addition, it is preferable to apply the present embodiment to a multi-core cable 2 having a total of four or more insulated wires 3, including an insulated wire 3 to which an inspection signal is input, two or more insulated wires 3 to which an auxiliary signal is input, and an insulated wire 3 to which no signal is input and in which noise caused by crosstalk should be reduced.

[0018] A coaxial wire 30 shown in FIG. 3 can be used as each of the multiple insulated wires 3 shown in FIG. 2. The coaxial wire 30 has a central conductor 31, and an insulator 32, an outer conductor (shield) 33, and an outer cover (jacket) 34, which are provided in this order around the central conductor 31. The insulator 32 is made of, for example, a foam layer. Within one coaxial wire 30, for example, seven metal strands form one stranded conductor. However, the central conductor 31 within the insulated wire 3 may be a solid wire. The insulated wire 3 may be made of only the central conductor 31 and the insulator 32. The outer diameter of the coaxial wire 30 is, for example, 0.2 mm to 0.5 mm. The diameter of the central conductor 31 is, for example, 50 μm.

[0019] As shown in FIG. 1, the multi-core cable inspection device 1 includes voltage sources V1, V2, and V3 which are inspection signal input means, and a phase shifter 7 which is a reference signal generating circuit.

[0020] The inspection signal input means is for inputting (applying) an AC inspection signal VA, a first auxiliary signal (first signal) VB, or a second auxiliary signal (second signal) VC (see FIG. 4) by capacitive coupling to an end of an insulated electric wire 3 to be inspected among the ends of the insulated electric wires 3 exposed at one end of the multi-core cable 2. In this embodiment, the inspection signal input means has a voltage source V1 that generates the inspection signal, a voltage source V2 that generates the first auxiliary signal, and a voltage source V3 that generates the second auxiliary signal. The inspection signal input means also has a plurality of switches (not shown) that switch which insulated electric wire 3 the inspection signal, the first auxiliary signal, or the second auxiliary signal is to be input to, and an electrode substrate (not shown) having a plurality of electrodes 41 (see FIG. 4) electrically connected to the outputs of the plurality of switches. The electrode substrate is used for inputting the inspection signal, the first auxiliary signal, or the second auxiliary signal to the insulated electric wire 3 by capacitive coupling by bringing the electrodes 41 into contact with the outer peripheral surface of the insulated electric wire 3.

[0021] As shown in Fig. 1, the voltage source V1 is electrically connected to the insulated wire 3 via a resistor r, a node N, and a coupling capacitance Ca in this order. The node N corresponds to the electrode 41 shown in Fig. 4. Similarly, each of the voltage sources V2 and V3 is electrically connected to the insulated wire 3 via a resistor r, a node N, and a coupling capacitance Ca in this order. Note that the resistor r is not connected to the insulated wire 3 to which none of the voltage sources V1 to V3 is connected.

[0022] If the first auxiliary signal and the second auxiliary signal are not input and only the inspection signal is input to one insulated wire 3 to be inspected, a signal (noise) similar to the inspection signal is induced and flows in other insulated wires 3 around the insulated wire 3 due to crosstalk. As a result, it becomes difficult to identify the correspondence between the ends of the insulated wires 3 to be inspected. Therefore, in this embodiment, the first auxiliary signal is input to a first insulated wire 3 different from the insulated wire 3 to be inspected, and the second auxiliary signal is input to the insulated wire 3 to be inspected and a second insulated wire 3 different from the first insulated wire 3. This prevents the amplitude (voltage) of the signal generated by crosstalk from becoming as large as the inspection signal, and improves the reliability of the inspection to identify the correspondence between the ends of the insulated wires 3.

[0023] Here, the inspection signal, the first auxiliary signal, and the second auxiliary signal are input to the insulated electric wire 3 by capacitive coupling, and therefore, AC signals are used as these signals. The frequencies of the inspection signal, the first auxiliary signal, and the second auxiliary signal must be lower than the resonance frequency in the multi-core cable 2, and can be set appropriately depending on the structure of the multi-core cable 2, etc. More specifically, the frequency is, for example, 1 kHz or more and 10 MHz or less. In this embodiment, for example, the inspection signal, the first auxiliary signal, and the second auxiliary signal are used at 2.5 MHz. Here, the frequencies of the inspection signal, the first auxiliary signal, and the second auxiliary signal are the same as each other.

[0024] 1 and 4 show only four insulated electric wires 3, but in reality there are, for example, 10 to 300 insulated electric wires 3. However, either the inspection signal, the first auxiliary signal or the second auxiliary signal is input to only three of the insulated electric wires 3, and no signal is input to the other insulated electric wires 3. In addition, although the multiple insulated electric wires 3 shown in FIGS. 1 and 4 are spaced apart from each other, in reality they are bundled together by a jacket 22 or the like as shown in FIG. 2. In other words, in FIGS. 1 and 4, the jacket 22 and the like that cover only both ends of each of the multiple insulated electric wires 3 are not shown.

[0025] As shown in FIG. 4, a plurality of insulated electric wires 3 (coaxial wires 30 in this case) exposed at one end (input side) of a multi-core cable are aligned and fixed on an inspection table (not shown). An electrode 41 is abutted against the surface (side surface in the short direction) of each end of the plurality of insulated electric wires 3 aligned in this manner. For example, an electrode board (dielectric board) on which a plurality of electrodes 41 are formed in a line and a wiring pattern is formed is sandwiched between the inspection table and the electrode board, so that the electrodes 41 come into contact with the insulated electric wires 3. The electrode board is formed with electrodes 41 in a number equal to or greater than the number of the insulated electric wires 3, aligned at the same intervals as the insulated electric wires 3. The electrodes 41 are electrically connected to the outputs of the plurality of switches, and an inspection signal, a first auxiliary signal, or a second auxiliary signal is input to the electrode 41 selected by the switch.

[0026] That is, when an inspection signal is input to any electrode 41, the inspection signal is input to the insulated wire 3 corresponding to that electrode 41 by capacitive coupling. In this embodiment, since a coaxial wire 30 is used as the insulated wire 3, the inspection signal is input to the outer conductor 33 of the insulated wire 3. A first auxiliary signal is input to another insulated wire 3 by capacitive coupling. A second auxiliary signal is input to yet another insulated wire 3 by capacitive coupling. In this manner, the inspection signal, the first auxiliary signal, and the second auxiliary signal are input to different insulated wires 3. Also, inspection is not performed in a state where any one of the inspection signal, the first auxiliary signal, and the second auxiliary signal is not input, and all three signals are input during inspection.

[0027] Each of the first auxiliary signal VB (see FIG. 4) and the second auxiliary signal VC (see FIG. 4) is a signal whose phase is changed by 180 degrees (π) to the inspection signal VA (see FIG. 4) by an inverse phase inspection signal input means (not shown) to make it an inverse phase, and whose amplitude (voltage) is 1 / 2 that of the inspection signal VA. In other words, the phase difference between each of the first auxiliary signal VB and the second auxiliary signal VC and the inspection signal VA is π.

[0028] The first auxiliary signal VB and the second auxiliary signal VC may be generated by adjusting the phase and amplitude (voltage) of the inspection signal VA, but this is not limiting, and a separate voltage source may be provided for generating the first auxiliary signal VB and the second auxiliary signal VC. Most preferably, the amplitude of each of the first auxiliary signal VB and the second auxiliary signal VC is 1 / 2 that of the inspection signal VA. In other words, the result of adding the voltage of the inspection signal VA to the first auxiliary signal VB having the opposite phase to the inspection signal VA and the second auxiliary signal VC having the opposite phase to the inspection signal VA is zero.

[0029] Similar to the inspection table provided at one end (input side) of the multi-core cable 2, an inspection table (not shown) is provided at the other end (output side) of the multi-core cable 2, and a plurality of electrodes 61 (see FIG. 4) provided on an electrode board (not shown) are pressed against each insulated electric wire 3. This causes an output signal from the insulated electric wire 3 (a signal transmitted through the outer conductor 33 shown in FIG. 3) to be output to the electrode 61 by capacitive coupling. The inspection table and electrode board on the output side have the same configuration as the inspection table and electrode board on the input side, and therefore a description thereof will be omitted here.

[0030] A switch for switching which insulated wire 3 to output an output signal from is electrically connected to each of electrodes 61 capacitively coupled to the output ends of the insulated wires 3. In Fig. 1 and Fig. 4, switches SW1 to SW4 electrically connected to electrodes 61 at the output ends of the four insulated wires 3 are shown as the switches, but in reality, a switch electrically connected to the input ends of the insulated wires 3 (not shown) is also provided. A multiplier (mixer) 4 is electrically connected to the output terminals of each of the switches SW1 to SW4, which multiplies the output signal of the inspection signal VA by a reference signal having the same frequency and phase as the output signal to generate a detection signal. One end of a resistor r1 is electrically connected between the output terminals of each of the switches SW1 to SW4 and the multiplier 4, and the other end of the resistor r1 is electrically connected to a ground.

[0031] A low-pass filter 6 that removes high-frequency components in the detection signal output from the multiplier 4 is electrically connected to the multiplier 4. An input terminal of the phase shifter 7 is electrically connected to the electrode 41 to which the inspection signal VA is input, and an output terminal of the phase shifter 7 is electrically connected to the multiplier 4. When signals of the same phase and frequency are multiplied by each other by the multiplier 4, a DC component and a component with a frequency twice the original frequency are generated. The low-pass filter 6 removes the component with the twice the frequency and outputs only the DC component as the detection signal. The low-pass filter 6 is composed of a resistor r2 and a capacitor Cf electrically connected between the resistor r2 and ground.

[0032] Phase shifter 7 has the role of adjusting the phase of the inspection signal branched off from voltage source V1 to generate a reference signal, amplifying it, and outputting it to multiplier 4. The phase amount in phase shifter 7 is appropriately adjusted in consideration of capacitive coupling and phase shift during transmission through multicore cable 2, so that the inspection signal and the reference signal have the same phase in multiplier 4.

[0033] The signal output from the low-pass filter 6 is measured by a calculation device 8 (not shown). The calculation device 8 is electrically connected to the resistor r2 and the capacitor Cf. The calculation device 8 measures the voltages of the output signals output from the ends of the insulated wires 3 exposed at the other end of the multi-core cable 2, and identifies the other end of the insulated wire 3 to be inspected based on the measured voltages of the output signals.

[0034] The arithmetic unit 8 controls the above-mentioned multiple switches on the input side and the multiple switches SW1 to SW4 on the output side to determine the correspondence between the ends of the insulated wires 3. In other words, by controlling the switches, the arithmetic unit 8 inputs an inspection signal VA to an end of a specific insulated wire 3 to be inspected at one end of the multi-core cable 2, inputs a first auxiliary signal VB to an end of any insulated wire 3, and inputs a second auxiliary signal VC to an end of any other insulated wire 3. Then, the arithmetic unit 8 controls the switches SW1 to SW4 on the output side to sequentially measure the voltages of the output signals corresponding to all the insulated wires 3 at the other end of the multi-core cable 2.

[0035] The computing device 8 identifies the end of each insulated electric wire 3 exposed at the other end of the multi-core cable 2 that has the highest voltage of the output signal as the other end of the insulated electric wire 3 to be inspected, and stores the correspondence relationship. The correspondence relationship between the ends of the insulated electric wires 3 is represented, for example, by associating numbers sequentially assigned to the ends of the insulated electric wires 3 aligned and arranged at one end of the multi-core cable 2 with numbers sequentially assigned to the ends of the insulated electric wires 3 aligned and arranged at the other end of the multi-core cable 2. The computing device 8 sequentially changes the insulated electric wire 3 to be inspected, and identifies and stores the correspondence relationships between the ends of all of the insulated electric wires 3.

[0036] As described above, in this embodiment, the end of the insulated wire 3 having the highest voltage output is identified as the other end of the insulated wire 3 to be inspected. After the identification of the correspondence between all the ends is completed, the correspondence between the insulated wires 3 at the input ends and the insulated wires 3 at the output ends is obtained. At this time, the insulated wires 3 at the output ends corresponding to the insulated wires 3 at different input ends may be the same. This is called overlap. At this time, it is determined that there is an error in the identification of the correspondence. Such overlap occurs because the crosstalk between the inspection signal VA, the first auxiliary signal VB, and the second auxiliary signal VC in a certain insulated wire 3 becomes unbalanced due to the relative positions of the insulated wires 3 that input the inspection signal, the first auxiliary signal VB, and the second auxiliary signal VC, the outer conductor 33 (see FIG. 3), and the insulated wires 3 that acquire the inspection signal, which may cause a false detection.

[0037] That is, the values ​​of capacitances C1 to C6 (see FIG. 1) between the insulated electric wires 3 differ from one another depending on the relative positions of the insulated electric wires 3, and depending on the combination of insulated electric wires 3 to which the inspection signal VA, the first auxiliary signal VB, and the second auxiliary signal VC are input, the crosstalk of each signal becomes unbalanced in a certain insulated electric wire 3. As a result, a signal similar to the inspection signal VA is induced in an insulated electric wire 3 other than the insulated electric wire 3 to which the inspection signal VA is input, causing overlap.

[0038] The calculation device 8 determines whether there is an overlap in the insulated electric wires 3 on the other side corresponding to the ends of the multiple insulated electric wires 3 exposed at one end of the multi-core cable 2. When the calculation device 8 determines that there is an overlap, the calculation device 8 changes the insulated electric wire 3 to which the first auxiliary signal VB or the second auxiliary signal VC, or both, are input to another insulated electric wire 3. Thereafter, the calculation device 8 again determines the correspondence between the ends of the insulated electric wires only for the insulated electric wires 3 at the input end where there is an overlap. In other words, when such a re-determination is performed, the auxiliary signal is not input to the insulated electric wires 3 to which the auxiliary signal was input when it was determined that there is an overlap, but the auxiliary signal is input to insulated electric wires 3 other than the insulated electric wire 3. As a result, a state occurs in which the crosstalk of each signal in the insulated electric wires 3 in which the correspondence between the ends is determined again is not unbalanced, making it possible to determine the correspondence between the ends.

[0039] <Inspection method for multi-core cables> Here, the inspection method for a multi-core cable according to the present embodiment will be described with reference to Figures 1, 2 and 4. Here, the insulated wire 3 to which the inspection signal VA is input is referred to as the insulated wire (first insulated wire) 3a, the insulated wire 3 to which the first auxiliary signal VB is input is referred to as the insulated wire (second insulated wire) 3b, the insulated wire 3 to which the second auxiliary signal VC is input is referred to as the insulated wire (third insulated wire) 3c, and the insulated wire 3 to which none of the inspection signal VA, the first auxiliary signal VB, and the second auxiliary signal VC is input is referred to as the insulated wire (fourth insulated wire) 3d.

[0040] The coupling capacitance at the capacitive coupling portion between the end of each insulated wire 3 and each electrode 41, 61 is Ca. The coupling capacitance between the insulated wires 3a and 3b is C1, the coupling capacitance between the insulated wires 3a and 3c is C2, and the coupling capacitance between the insulated wires 3a and 3d is C3. The coupling capacitance between the insulated wires 3b and 3c is C4, the coupling capacitance between the insulated wires 3b and 3d is C5, and the coupling capacitance between the insulated wires 3c and 3d is C6. The voltages of the output signals of the insulated wires 3a, 3b, 3c, and 3d are v1, v2, v3, and v4, respectively.

[0041] In the method for inspecting a multi-core cable according to the present embodiment, first, a predetermined length of the jacket 22 and the collective shield 21 (see FIG. 2) are removed at each end of the multi-core cable 2 to expose both ends of the insulated wires 3. Then, at each end of the multi-core cable 2, the exposed insulated wires 3 are fixed to an inspection table, and electrodes 41, 61 are pressed against both ends of each insulated wire 3, respectively. Then, an inspection is performed to identify the correspondence between the ends of the insulated wires 3.

[0042] In this inspection, an inspection signal VA is input to an arbitrary insulated wire 3 (insulated wire 3a in this case). At the same time, a first auxiliary signal VB is input to an arbitrary insulated wire 3 other than the insulated wire 3a (insulated wire 3b in this case). At the same time, a second auxiliary signal VC is input to an arbitrary insulated wire 3 other than the insulated wires 3a and 3b (insulated wire 3c in this case).

[0043] The inspection signal VA, the first auxiliary signal VB, and the second auxiliary signal VC have the same frequency. The first auxiliary signal VB and the second auxiliary signal VC are in opposite phase to the inspection signal VA and have an amplitude (voltage) that is half that of the inspection signal. At a given time, the sum of the voltage of the inspection signal VA, the first auxiliary signal VB having the opposite phase to the inspection signal VA, and the second auxiliary signal VC having the opposite phase to the inspection signal VA is zero.

[0044] As described above, the method for inspecting a multi-core cable in this embodiment includes the steps of inputting an inspection signal VA by capacitive coupling to an end of a first insulated wire to be inspected among multiple insulated wires exposed at one end of the multi-core cable, inputting a first auxiliary signal VB of a different phase from the inspection signal VA by capacitive coupling to an end of a second insulated wire other than the first insulated wire among multiple insulated wires exposed at one end of the multi-core cable, and inputting a second auxiliary signal VC of a different phase from the inspection signal VA by capacitive coupling to an end of a third insulated wire other than the first insulated wire and the second insulated wire among multiple insulated wires exposed at one end of the multi-core cable.

[0045] Next, the switches SW1 to SW4 electrically connected to the output sides of the insulated electric wires 3 are controlled to turn on the switches SW1 to SW4 one by one in order. That is, for example, the switch SW1 is turned on and the other switches SW2 to SW4 are turned off. Next, the switches SW1, SW3 and SW4 are turned off and the switch SW2 is turned on. In this manner, the output signals of the insulated electric wires 3 are received one by one. The received output signal is multiplied by a reference signal by the multiplier 4. Here, the reference signal has the same phase as the phase of the inspection signal VA when it reaches the multiplier. Also, only the DC (direct current) component is selected from the output signal of the multiplier 4 using the low-pass filter 6 to obtain a calculated output signal. The values ​​of these calculated output signals are stored in the calculation device 8.

[0046] Next, the calculation device 8 identifies the end of each insulated electric wire 3 that outputs the largest signal (here, the signal obtained by multiplying the output signal by a reference signal) as the other end of the insulated electric wire 3 being inspected, and stores this correspondence.

[0047] Next, an inspection signal VA is input to an insulated wire 3 other than the insulated wire 3a. At this time, the phase shifter 7 is also electrically connected to the electrode 41 (node ​​N) that is abutted against the end of the insulated wire 3 other than the insulated wire 3a. In addition, a first auxiliary signal VB and a second auxiliary signal VC are input to two insulated wires 3 other than the insulated wire 3, respectively. Next, the switches SW1 to SW4 are controlled to measure the calculated output signals of the multiple insulated wires 3 one by one, thereby identifying the other end of the insulated wire 3 to be inspected.

[0048] In this manner, the inspection signal VA is input sequentially to each of the multiple insulated wires 3, and the output signals of the multiple insulated wires 3 are measured each time, thereby identifying the correspondence between both ends of all of the insulated wires 3 and storing the identified correspondence in the arithmetic device 8. This completes the inspection for identifying the correspondence between the ends of the insulated wires 3 exposed from both ends of the multi-core cable 2. The arithmetic device 8 outputs the identified stored correspondence to, for example, a monitor. Then, the process ends.

[0049] As described above, the inspection method for a multi-core cable of this embodiment includes the steps of measuring the voltage of an output signal output by capacitive coupling from each end of the insulated electric wires exposed at the other end of the multi-core cable, and identifying the other end of the first insulated electric wire based on the measured voltages.

[0050] However, there may be cases where duplication occurs during the above inspection process. After the determination of the correspondence between all ends is completed, the correspondence between the insulated electric wires 3 at the output end corresponding to the insulated electric wires 3 at each input end is obtained. At this time, the insulated electric wires 3 at the output end corresponding to the insulated electric wires 3 at different input ends may be the same. This is called duplication. At this time, it is determined that there is an error in the determination of the correspondence. The calculation device 8 determines whether there is duplication in the insulated electric wires 3 on the other side corresponding to the ends of the multiple insulated electric wires 3 exposed at one end of the multi-core cable 2. When the calculation device 8 determines that there is duplication, the calculation device 8 changes the insulated electric wire 3 to which the first auxiliary signal VB or the second auxiliary signal VC or both are input to another insulated electric wire 3. After that, the calculation device 8 again determines the correspondence between the ends of the insulated electric wires only for the insulated electric wires 3 at the input end where there is duplication. As a result, a state in which the crosstalk of each signal in the insulated electric wires 3 for which the correspondence between the ends is determined again occurs probabilistically and it becomes possible to specify it.

[0051] In the present embodiment, a case has been described in which an auxiliary signal is input to only two insulated electric wires 3, but the number of insulated electric wires 3 to which an auxiliary signal is input may be two or more. That is, an inspection signal is input to one insulated electric wire 3, and m auxiliary signals are input to m insulated electric wires 3. In this case, m is a natural number that is 2 or more and is a natural number that is n-1 or less. In other words, the value of m, which is a natural number, is expressed as n-1≧m≧2. Furthermore, the voltage amplitude of the auxiliary signal input to each insulated electric wire 3 is preferably 1 / m of the voltage amplitude of the inspection signal. For example, when m=3, first to third auxiliary signals having a voltage amplitude that is 1 / 3 of the voltage amplitude of the inspection signal are input to three insulated electric wires 3, respectively.

[0052] The inspection signal and each auxiliary signal have the same frequency, and the phase of each auxiliary signal is the opposite phase of the inspection signal (a phase shifted by π with respect to the inspection signal). Therefore, the amplitude (voltage) of a signal obtained by adding the inspection signal to any one of the 1st to mth auxiliary signals is smaller than the amplitude (voltage) of the inspection signal. Furthermore, the amplitude (voltage) of a signal obtained by adding the inspection signal to all of the 1st to mth auxiliary signals is smaller than the amplitude (voltage) of the inspection signal.

[0053] <Effects of this embodiment> As an inspection method for identifying the correspondence between the ends of insulated electric wires exposed from both ends of one multi-core cable, it is possible to perform the inspection by inputting an inspection signal to one insulated electric wire and not inputting a signal to the other insulated electric wires. However, in this inspection method, crosstalk between the insulated electric wires is large, and a signal (noise) having a voltage (amplitude) similar to that of the inspection signal is induced in an insulated electric wire other than the insulated electric wire to which the inspection signal is input. As a result, the signal-to-noise ratio, which is the ratio of the inspection signal to the induced signal (noise), becomes small, which causes a problem that it is difficult to identify the correspondence between the ends of the insulated electric wires to be inspected. For this reason, there is a risk of erroneous detection in the inspection of the correspondence between the ends of the insulated electric wires.

[0054] In contrast, as a comparative example, as shown in Figs. 8 and 9, it is conceivable to suppress the occurrence of crosstalk by inputting an inspection signal to insulated wire 3a of the multiple insulated wires 3 and inputting an opposite-phase inspection signal (auxiliary signal) to the remaining insulated wire 3b. The opposite-phase inspection signal in the comparative example is a signal in which the phase of the inspection signal is shifted by 180 degrees (π) to make it the opposite phase, and has the same amplitude (voltage) as the inspection signal. Fig. 8 is an equivalent circuit diagram showing the configuration of a multi-core cable inspection device used in the multi-core cable inspection method according to the comparative example. Fig. 9 is a schematic diagram showing the configuration of a multi-core cable inspection device used in the multi-core cable inspection method according to the comparative example.

[0055] The configuration of the inspection device shown in Figures 8 and 9 is similar to the configuration of the inspection device of this embodiment shown in Figures 1 and 4, except that the number of insulated electric wires 3 to which the auxiliary signal is input is smaller and the voltage (amplitude) of the auxiliary signal is larger.

[0056] Here, basically, the multiple coupling capacitances Ca shown in FIG. 1 are all almost the same value (for example, 2 pF). However, some coupling capacitances Ca may have a value different from the other coupling capacitances Ca (for example, 1.995 pF). That is, the multiple coupling capacitances Ca may vary. This may be caused, for example, by the gap between the electrode 41 for inputting the antiphase inspection signal (auxiliary signal) and the external conductor (shield) 33 (see FIG. 3) in the insulated electric wire 3 being larger than the gap between the other electrodes 41, 61 and the external conductor 33 in the insulated electric wire 3. That is, the gap between the electrodes 41, 61 and the external conductor 33 may change depending on the position of the external conductor 33 or the distance between the insulated electric wire 3 and the electrodes 41, 61. When the gap between the electrode 41 for inputting the antiphase inspection signal (auxiliary signal) and the external conductor 33 becomes large, the coupling capacitance Ca becomes small and the input impedance increases, so that the input level of the auxiliary signal decreases. As a result, in the comparative example, the effect of reducing crosstalk decreases, and a problem of deterioration (deterioration) of the S / N ratio may occur. Therefore, it is required to specify the correspondence between the ends of the insulated wires 3 more accurately than in the comparative example.

[0057] In contrast, in the method for inspecting a multi-core cable according to the present embodiment, an inspection signal VA is inputted by capacitive coupling to an end of a first insulated electric wire to be inspected among the ends of the insulated electric wires exposed at one end of the multi-core cable. At the same time, a first signal (first auxiliary signal VB) having a phase different from that of the inspection signal is inputted by capacitive coupling to an end of a second insulated electric wire other than the first insulated electric wire among the ends of the multiple insulated electric wires exposed at one end of the multi-core cable, and a second signal (second auxiliary signal VC) having a phase different from that of the inspection signal VA is inputted by capacitive coupling to an end of a third insulated electric wire other than the first insulated electric wire and the second insulated electric wire among the ends of the multiple insulated electric wires exposed at one end of the multi-core cable. Then, the calculation device 8 measures the DC component of the signal voltage obtained by multiplying the output signal outputted via capacitive coupling from each end of the insulated electric wires 3 exposed at the other end of the multi-core cable 2 by a reference signal, and identifies the other end of the insulated electric wire 3 to be inspected based on the measured voltage (here, a detection signal obtained by multiplying the output signal by the reference signal).

[0058] More specifically, an auxiliary signal that is in opposite phase to the inspection signal and has an amplitude of 1 / m of the inspection signal is input by capacitive coupling to each of m (n-1≧m≧2) ends of the insulated wires 3 other than the insulated wire 3 to be inspected, among the ends of the insulated wires 3 exposed at one end of the multi-core cable 2.

[0059] By inputting the inspection signal and two or more auxiliary signals, in the other insulated electric wires 3 to which those signals have not been input, those signals crosstalk with each other and cancel each other out. As a result, it is possible to suppress the effects of crosstalk and accurately identify the correspondence between the ends of the insulated electric wires 3. The present invention is particularly suitable for use with a multi-core cable 2 in which many insulated electric wires 3 are densely arranged and in which the coupling capacitance between the insulated electric wires 3 is large. In addition, in a multi-core cable 2 having an ensemble shield 21 (see FIG. 2), the coupling capacitance is larger than in a case without the ensemble shield 21, and therefore the use of the present invention is highly effective.

[0060] The table in Fig. 5 shows the results of inspection of the correspondence between the ends of the insulated wires 3, which was performed using inspection devices for multi-core cables in the comparative example and the present embodiment. In the table in Fig. 5, the second column from the left shows the inspection results for the comparative example, and the third column from the left shows the inspection results for the present embodiment (example). The leftmost item column in the table shows, from top to bottom, the insulated wire 3a, the insulated wire 3b, the insulated wire 3c, the insulated wire 3d, the voltage Vmax1, the voltage Vmax2, and the S / N ratio. An inspection signal VA is input to the insulated wire 3a, a first auxiliary signal VB is input to the insulated wire 3b, a second auxiliary signal VC is input to the insulated wire 3c, and no signal is input to the insulated wire 3d.

[0061] The two columns to the right of the insulated wire 3a in Fig. 5 show the voltages output from the insulated wire 3a when only switch SW1 shown in Fig. 1 (Example) and Fig. 9 (Comparative Example) is turned on. Similarly, the two columns to the right of the insulated wire 3b show the voltages output from the insulated wire 3b when only switch SW2 is turned on. Similarly, the two columns to the right of the insulated wire 3c show the voltages output from the insulated wire 3c when only switch SW3 is turned on. Similarly, the two columns to the right of the insulated wire 3d show the voltages output from the insulated wire 3d when only switch SW4 is turned on.

[0062] The column to the right of the voltage Vmax1 shown in the item indicates the maximum value of the voltage output from the insulated wires 3a to 3d. The column to the right of the voltage Vmax2 shown in the item indicates the second largest value of the voltages output from the insulated wires 3a to 3d. The larger the ratio of the voltage Vmax1 to the voltage Vmax2, the more the S / N ratio deteriorates, making it difficult to identify the correspondence between the insulated wires. The S / N ratio is calculated as Vmax1 / Vmax2.

[0063] As shown in Fig. 5, the magnitude of the voltage output from the insulated wire 3a to which the inspection signal VA is input is almost the same in both the comparative example and the example (present embodiment). However, the value of voltage Vmax2 in the comparative example is relatively large at 3.7 µV, whereas the value of voltage Vmax2 in the example is suppressed to 1.76 µV. Therefore, since the SN ratio is higher in the example (4.2) than in the comparative example (2.4), it can be seen that the present embodiment can identify the correspondence relationship of the insulated wire more reliably and with higher accuracy than the comparative example.

[0064] In this manner, in this embodiment, a plurality of auxiliary signals are input to different insulated wires, so that deterioration of the S / N ratio can be suppressed. That is, for example, when the coupling capacitance (electrostatic capacitance) between the electrode to which the first auxiliary signal VB is input and the insulated wire is lower than the coupling capacitance (electrostatic capacitance) between the other electrodes and the insulated wire, the input impedance increases and the input level of the auxiliary signal decreases. This reduces the crosstalk reduction effect and deteriorates the S / N ratio. However, in this embodiment, since two or more auxiliary signals are input, even if there is variation in the coupling capacitance, auxiliary signals are input from the other electrodes, so that deterioration of the S / N ratio is suppressed. Therefore, in this embodiment, the reliability of the multi-core cable inspection method and the multi-core cable inspection device can be improved.

[0065] It is also possible to increase the length of the electrodes 41, 61 and the contact area between the electrodes 41, 61 and the insulated wire 3, thereby increasing the coupling capacitance Ca between the electrodes 41, 61 and the insulated wire 3 and suppressing crosstalk between the insulated wires 3. However, in this case, the inspection table and the electrode substrate become larger. Also, the length of the insulated wire 3 exposed for inspection becomes longer, and the excess length of the insulated wire 3 removed when mounted on a substrate or the like becomes longer, resulting in a lot of waste. According to this embodiment, even when the electrodes 41, 61 are relatively short and the contact area between the electrodes 41, 61 and the insulated wire 3 is relatively small, it is possible to accurately determine the correspondence between the ends of the insulated wire 3.

[0066] Furthermore, in this embodiment, the auxiliary signal is in opposite phase to the inspection signal, so that the auxiliary signal can be easily generated, the circuit configuration can be simplified, and power consumption can be reduced.

[0067] <Modification> Although FIG. 4 illustrates the use of a flat electrode as the electrode pressed against the insulated wire 3, a cylindrical conductor tube surrounding the periphery of the insulated wire 3 in the radial direction may be used as the electrode.

[0068] The perspective view of Fig. 6 shows conductor tubes 42 and 62 which are part of the inspection device for a multi-core cable of this modified example, and an insulated electric wire 3 which constitutes the multi-core cable used for the inspection. The conductor tubes 42 and 62 shown in Fig. 6 can be used in place of the electrodes 41 and 61 shown in Fig. 4. The conductor tube 42 is a cylindrical electrode arranged so as to cover the periphery in the radial direction of the input end of the insulated electric wire 3 which constitutes the multi-core cable 2 (see Fig. 4). The conductor tube 62 is a cylindrical electrode arranged so as to cover the periphery in the radial direction of the output end of the insulated electric wire 3 which constitutes the multi-core cable 2. A signal is input to the insulated electric wire 3 by capacitive coupling via the conductor tube 42, and the signal is output via the coupling capacitance between the insulated electric wire 3 and the conductor tube 62.

[0069] In this embodiment, a cylindrical conductor tube is used as an electrode that is capacitively coupled to the insulated electric wire, and the end of the insulated electric wire is passed through the conductor tube. In other words, the inspection signal, the first auxiliary signal, and the second auxiliary signal are input to the multiple insulated electric wires by capacitive coupling through the cylindrical conductor tube that surrounds the radial periphery of each of the multiple insulated electric wires. Therefore, even if the position of the insulated electric wire is shifted within the conductor tube, the variation in the coupling capacitance between the conductor tube and the insulated electric wire is limited to a certain range. Therefore, it is possible to prevent the coupling capacitance between the conductor tube and the insulated electric wire from varying excessively, and therefore it is possible to perform a more stable inspection of a multi-core cable.

[0070] (Embodiment 2) In the first embodiment, the input of an auxiliary signal having an opposite phase to the inspection signal to a plurality of insulated wires has been described, but here, the input of auxiliary signals having phase differences shifted by 2π / (m+1) from the inspection signal to a plurality of insulated wires will be described with reference to Fig. 7. Fig. 7 is a schematic diagram showing the configuration of an inspection device for a multicore cable according to this embodiment.

[0071] The configuration of the multi-core cable inspection device 1 of the present embodiment is similar to that of the multi-core cable inspection device of the above-described embodiment 1. However, the phase and amplitude of each auxiliary signal are different from those of the above-described embodiment 1.

[0072] That is, as shown in FIG. 7, an inspection signal VA is input to insulated wire 3a, a first auxiliary signal VB is input to insulated wire 3b, a second auxiliary signal VC is input to insulated wire 3c, and no signal is input to insulated wire 3d.

[0073] The phase difference between the first auxiliary signal VB and the inspection signal VA is 1×2π / 3, and the phase difference between the second auxiliary signal VC and the inspection signal VA is 2×2π / 3. That is, when an auxiliary signal is input to each of m insulated electric wires 3, the phase difference between the auxiliary signal (k-th signal, k-th signal) input to the k-th insulated electric wire and the inspection signal VA is k×2π / (m+1). In this case, m is a natural number of 2 or more, and k is a natural number of 1 or more and m or less. Also, unlike the first embodiment, the magnitude of the voltage amplitude of each auxiliary signal is the same as the magnitude of the voltage amplitude of the inspection signal VA regardless of the value of m. Also, the inspection signal VA and each auxiliary signal have the same wavelength.

[0074] In other words, when the three signals of inspection signal VA, first auxiliary signal VB, and second auxiliary signal VC are input to multi-core cable 2, the phase difference between inspection signal VA and first auxiliary signal VB, the phase difference between first auxiliary signal VB and second auxiliary signal VC, and the phase difference between second auxiliary signal VC and inspection signal VA are all 2π / 3.

[0075] The amplitude of the signal obtained by adding together the amplitude (voltage) of the checking signal VA and all of the auxiliary signals from the 1st to mth auxiliary signals is smaller than the amplitude of the checking signal VA. Specifically, the amplitude (voltage, voltage amplitude) of the sum of the amplitude (voltage) of the checking signal VA at a given time point and the amplitude (voltage) of all of the auxiliary signals from the 1st to mth auxiliary signals is zero.

[0076] In the method for inspecting a multi-core cable according to the present embodiment, an inspection signal is inputted by capacitive coupling to an end of an insulated electric wire 3 to be inspected among the ends of the insulated electric wires 3 exposed at one end of the multi-core cable 2. At the same time, an auxiliary signal having a phase difference of 2π / (m+1) with respect to the inspection signal is inputted by capacitive coupling to each of the first to mth (n-1≧m≧2) ends of the insulated electric wires 3 other than the insulated electric wire 3 to be inspected among the ends of the insulated electric wires 3 exposed at one end of the multi-core cable 2. The phase difference between the auxiliary signal inputted to the kth insulated electric wire 3 among the m insulated electric wires 3 and the inspection signal is k×2π / (m+1). Then, the DC component of the signal voltage obtained by multiplying the output signal outputted by capacitive coupling from each end of the insulated electric wires 3 exposed at the other end of the multi-core cable 2 by the reference signal is measured, and the other end of the insulated electric wire 3 to be inspected is identified based on the measured voltage.

[0077] In other words, in this embodiment, m auxiliary signals including the first auxiliary signal and the second auxiliary signal excluding the inspection signal are input to each of the ends of m insulated wires 3 other than the insulated wire 3a among the ends of the multiple insulated wires 3 exposed at one end of the multi-core cable 2. At this time, the phase difference between the inspection signal and the auxiliary signal input by the inspection signal input means to the k-th insulated wire 3 among the m insulated wires 3 is k×2π / (m+1).

[0078] By inputting the inspection signal and two or more auxiliary signals, in other insulated electric wires 3 to which those signals are not input, those signals crosstalk and cancel each other out. As a result, it is possible to suppress the influence of crosstalk and accurately identify the correspondence between the ends of the insulated electric wires 3. Therefore, in this embodiment, deterioration of the S / N ratio is suppressed, and the reliability of the multi-core cable inspection method and the multi-core cable inspection device can be improved.

[0079] The invention made by the present inventors has been specifically described above based on an embodiment, but it goes without saying that the present invention is not limited to the above embodiment and can be modified in various ways without departing from the gist of the invention. [Explanation of symbols]

[0080] 1. Multi-core cable inspection equipment 2 Multi-core cable 3, 3a~3d Insulated wire 4. Multiplier 6 Low-pass filters 7 Phaser 8 Arithmetic unit 30 coaxial line 41, 61 electrode

Claims

1. A method for inspecting a multi-core cable, in which n insulated electric wires are bundled together, where n is a natural number of 3 or more and m is a natural number between 2 and n-1, inclusive, for identifying a correspondence relationship between ends of the insulated electric wires exposed from both ends of the multi-core cable, the method comprising: (a) inputting an inspection signal by capacitive coupling to an end of a first insulated electric wire to be inspected among the ends of the multiple insulated electric wires exposed at one end of the multi-core cable, and inputting first to mth signals having a phase different from that of the inspection signal by capacitive coupling to ends of m insulated electric wires other than the first insulated electric wire among the ends of the insulated electric wires exposed at one end of the multi-core cable, respectively; (b) measuring a voltage of an output signal output by capacitive coupling from each end of the insulated electric wire exposed at the other end of the multi-core cable, and identifying the other end of the first insulated electric wire based on the measured voltage; having the inspection signal and the first to m-th signals have the same frequency; the amplitude of a signal obtained by adding any one of the first to m-th signals and the inspection signal is smaller than the amplitude of the inspection signal, and the amplitude of a signal obtained by adding all of the first to m-th signals and the inspection signal is smaller than the amplitude of the inspection signal; A method for inspecting a multi-core cable, wherein each of the first to m-th signals has an opposite phase to the inspection signal.

2. 2. The method for inspecting a multi-core cable according to claim 1, The method for inspecting a multi-core cable, wherein the amplitude of each of the first to mth signals is 1 / m of the inspection signal.

3. A method for inspecting a multi-core cable, in which n insulated electric wires are bundled together, where n is a natural number of 3 or more and m is a natural number between 2 and n-1, inclusive, for identifying a correspondence relationship between ends of the insulated electric wires exposed from both ends of the multi-core cable, the method comprising: (a) inputting an inspection signal by capacitive coupling to an end of a first insulated electric wire to be inspected among the ends of the multiple insulated electric wires exposed at one end of the multi-core cable, and inputting first to mth signals having a phase different from that of the inspection signal by capacitive coupling to ends of m insulated electric wires other than the first insulated electric wire among the ends of the insulated electric wires exposed at one end of the multi-core cable, respectively; (b) measuring a voltage of an output signal output by capacitive coupling from each end of the insulated electric wire exposed at the other end of the multi-core cable, and identifying the other end of the first insulated electric wire based on the measured voltage; having the inspection signal and the first to m-th signals have the same frequency; the amplitude of each of the first to mth signals is the same as the amplitude of the inspection signal; the amplitude of a signal obtained by adding all of the first to mth signals and the inspection signal is smaller than the amplitude of the inspection signal; A method for inspecting a multi-core cable, wherein a phase difference between a k-th signal among the first to m-th signals and the inspection signal is k×2π / (m+1).

4. The method for inspecting a multi-core cable according to any one of claims 1 to 3, a first signal and a second signal are respectively input to a plurality of insulated electric wires by capacitive coupling through a cylindrical conductor tube that radially surrounds each of the plurality of insulated electric wires.

5. The method for inspecting a multi-core cable according to any one of claims 1 to 4, a voltage amplitude of a signal obtained by adding together the inspection signal and all of the first to mth signals is zero; How to inspect multi-core cables.

6. The method for inspecting a multi-core cable according to any one of claims 1 to 5, A method for inspecting a multi-core cable, comprising: identifying the other end of the first insulated wire based on a DC component of a voltage of a detection signal obtained by multiplying an output signal output from ends of a plurality of the insulated wires exposed at the other end of the multi-core cable by a reference signal that is in phase with the output signal of the inspection signal.

7. 7. The method for inspecting a multi-core cable according to claim 6, a first insulated wire having a first voltage component larger than the first voltage component of the first insulated wire;

8. The method for inspecting a multi-core cable according to any one of claims 1 to 7, determining whether there is an overlap between the insulated electric wires on the other side corresponding to the ends of the plurality of insulated electric wires exposed at one end of the multi-core cable; Among the multiple insulated electric wires having overlaps, the insulated electric wire to which some or all of the first to m-th signals are input is changed, and the correspondence relationship between the ends of the insulated electric wires is identified again. How to inspect multi-core cables.

9. A multi-core cable inspection device for identifying a correspondence relationship between ends of insulated electric wires exposed from both ends of a multi-core cable in which n insulated electric wires are bundled together, where n is a natural number of 3 or more and m is a natural number between 2 and n-1, comprising: an inspection signal input unit that inputs an inspection signal by capacitive coupling to an end of a first insulated wire that is to be inspected, among the ends of the insulated wires exposed at one end of the multi-core cable; an inspection signal input means for inputting, by capacitive coupling, first to m-th signals having a phase different from that of the inspection signal to ends of the m insulated electric wires other than the first insulated electric wire among ends of the insulated electric wires exposed at one end of the multi-core cable; a calculation device that measures an output voltage output by capacitive coupling from each end of the insulated electric wire exposed at the other end of the multi-core cable, and identifies the other end of the first insulated electric wire based on the output voltage; and having the inspection signal and the first to m-th signals have the same frequency; the amplitude of a signal obtained by adding any one of the first to m-th signals and the inspection signal is smaller than the amplitude of the inspection signal, and the amplitude of a signal obtained by adding all of the first to m-th signals and the inspection signal is smaller than the amplitude of the inspection signal; A multi-core cable inspection device, wherein each of the first to m-th signals has an opposite phase to the inspection signal.

10. 10. The multi-core cable inspection device according to claim 9, An inspection device for a multi-core cable, wherein the amplitude of each of the first to mth signals is 1 / m of the inspection signal.

11. A multi-core cable inspection device for identifying a correspondence relationship between ends of insulated electric wires exposed from both ends of a multi-core cable in which n insulated electric wires are bundled together, where n is a natural number of 3 or more and m is a natural number between 2 and n-1, comprising: an inspection signal input unit that inputs an inspection signal by capacitive coupling to an end of a first insulated wire that is to be inspected, among the ends of the insulated wires exposed at one end of the multi-core cable; an inspection signal input means for inputting, by capacitive coupling, first to m-th signals having a phase different from that of the inspection signal to ends of the m insulated electric wires other than the first insulated electric wire among ends of the insulated electric wires exposed at one end of the multi-core cable; a calculation device that measures an output voltage output by capacitive coupling from each end of the insulated electric wire exposed at the other end of the multi-core cable, and identifies the other end of the first insulated electric wire based on the output voltage; and having the inspection signal and the first to m-th signals have the same frequency; the amplitude of each of the first to mth signals is the same as the amplitude of the inspection signal; the amplitude of a signal obtained by adding all of the first to mth signals and the inspection signal is smaller than the amplitude of the inspection signal; A multi-core cable inspection device, wherein a phase difference between a k-th signal among the first to m-th signals and the inspection signal is k×2π / (m+1).

12. The multi-core cable inspection device according to any one of claims 9 to 11, The inspection signal input means inputs the inspection signal and the first to mth signals to the multiple insulated electric wires by capacitive coupling via a cylindrical conductor tube that radially surrounds each of the multiple insulated electric wires.

13. The multi-core cable inspection device according to any one of claims 9 to 12, a voltage amplitude of a signal obtained by adding together the inspection signal and all of the first to mth signals is zero; Multi-core cable inspection device.

14. The multi-core cable inspection device according to any one of claims 9 to 13, determining whether there is an overlap between the insulated electric wires on the other side corresponding to the ends of the plurality of insulated electric wires exposed at one end of the multi-core cable; Among the multiple insulated electric wires having overlaps, the insulated electric wire to which some or all of the first to m-th signals are input is changed, and the correspondence relationship between the ends of the insulated electric wires is identified again. Multi-core cable inspection device.

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