Disconnection detection device

Abstract

To provide a disconnection detection device capable of detecting an occurrence of disconnection in a single wire.SOLUTION: A device for detecting disconnection of a single wire among a plurality wires of insulation wires 101 having a conductor 102 composed of a plurality of single wire include: a branching unit 6 having a common conductive path 61 and a plurality of branching conduction paths 62 provided to branch from the common conductive path 61 as well as having one end unit of the conductor 102 of a corresponding insulation wire 101 electrically connected to each of the tip units of the branching conduction paths 62; a current ratio detection unit 7 capable of detecting the ratio of the current flowing in the plurality of branching conduction paths 62; and a disconnection detection processing unit 22 for detecting disconnection of a single wire in the plurality of insulation wires 101 based on the detection result in the current ratio detection unit 7.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a wire break detection device. [Background technology]

[0002] In cables wired to moving parts of equipment such as industrial robots, the wires that make up the conductor gradually break due to repeated bending, twisting, and other movements of the moving parts, and ultimately lead to a break in the conductor. Therefore, it is desirable to detect the break in the wires and replace the cable before the entire conductor breaks.

[0003] When a break occurs in one of the wires that make up the conductor, the resistance of the conductor increases, so in the past, breaks in the wires were detected by measuring the resistance of the conductor. For example, the resistance of the conductor was measured in an initial state where no breaks occurred, and a break in the wire was detected when the resistance increased from the resistance in the initial state.

[0004] Prior art document information related to the invention of this application includes Patent Document 1. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2007-139488 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the resistance of a conductor is small, on the order of milliohms or less, and if the number of broken wires that make up the conductor is small, the increase in the resistance of the conductor is extremely small. Furthermore, the resistivity of the conductor and the contact potential generated between the electrodes of a resistance measuring instrument and the conductor being measured vary with temperature, so the resistance of the conductor also varies with temperature, making it difficult to detect a slight increase in resistance. Therefore, breaks cannot be detected unless the number of broken wires that make up the conductor increases (unless the resistance increases by several tens of percent from the initial value), making it difficult to detect breaks early.

[0007] SUMMARY OF THE PRESENT EMBODIMENTS Accordingly, an object of the present invention is to provide a wire breakage detection device capable of detecting the occurrence of a break in a wire with high sensitivity. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, the present invention provides an apparatus for detecting a break in a wire in a plurality of insulated wires having a conductor composed of a plurality of wires, the apparatus comprising: a common conductive path and a plurality of branch conductive paths arranged to branch off from a tip of the common conductive path, and comprising: branch sections to which one ends of the conductors of the corresponding insulated wires are electrically connected, each of the tips of the branch conductive paths; a current ratio detection section capable of detecting a ratio of currents flowing through the plurality of branch conductive paths; and a break detection processing section that detects a break in the wires in the plurality of insulated wires based on a detection result of the current ratio detection section. Effect of the Invention

[0009] According to the present invention, it is possible to provide a wire breakage detection device capable of detecting the occurrence of a break in a wire with high sensitivity. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic configuration diagram of a wire break detection device according to an embodiment of the present invention; [Diagram 2] FIG. 1A is a perspective view of the connector, and FIG. 1B is a cross-sectional view showing a cross section perpendicular to the longitudinal direction of the cable. [Diagram 3] FIG. 2 is a plan view of a branching portion and a magnetic sensor. [Figure 4] 13(a) and 13(b) are diagrams illustrating detection of a wire breakage. [Diagram 5] FIG. 4 is a diagram illustrating an example of a sensor output of a magnetic sensor. [Figure 6] 1 is a flow diagram of a disconnection detection method according to an embodiment of the present invention. [Figure 7] 1A and 1B are diagrams showing a modified example of the present invention, in which (a) is a cross-sectional view showing a cross section perpendicular to the longitudinal direction of a cable, and (b) is a diagram showing the arrangement of a branching portion and a magnetic sensor. [Figure 8] 1A and 1B are diagrams showing a modified example of the present invention, in which (a) is a cross-sectional view showing a cross section perpendicular to the longitudinal direction of a cable, and (b) is a diagram showing the arrangement of a branching portion and a magnetic sensor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0012] Fig. 1 is a schematic diagram of a disconnection detection device 1 according to the present embodiment. Fig. 2(a) is a perspective view of a connector 13, and Fig. 2(b) is a cross-sectional view showing a cross section perpendicular to the longitudinal direction of a cable 10.

[0013] The disconnection detection device 1 is a device that detects disconnection of a wire made of a metal wire constituting a conductor 102 of the cable 10, which is provided with an action such as bending, twisting, or swinging based on the actual operation of the device 11 and is wired to an arbitrary device (managed device) 11 managed by an device user or device manufacturer. For example, the device 11 has a movable part 11b, and the cable 10 is wired so as to pass through the movable part 11b. By operating the movable part 11b of the device 11, the cable 10 is repeatedly bent, twisted, swing, or the like. FIG. 1 shows a case where the device 11 to which the cable 10 is wired is an industrial robot 11a. However, the device 11 may be a vehicle such as an automobile.

[0014] Hereinafter, the term "breakage of a wire" means that each of the wires constituting the conductor 102 of the cable 10 is broken. The term "breakage progression state of the conductor 102" means the breakage rate, or how many of the wires constituting the conductor 102 are broken due to repeated bending, twisting, swinging, and other movements of the cable 10, that is, the number of broken wires among the number of wires constituting the conductor 102. The breakage progression state of the conductor 102 can be expressed as the ratio (%) of the number of broken wires to the total number of wires constituting the conductor 102. For example, when the breakage rate of the conductor 102 is 100%, it indicates that all of the wires constituting the conductor 102 are broken. In other words, the breakage progression state of the conductor 102 can be said to be the breakage progression state of the cable 10.

[0015] Moreover, "disconnection of the conductor 102" means that the disconnection rate of the wires constituting the conductor 102 reaches a preset rate, and the conductor 102 is determined to have been disconnected. For example, the state in which the conductor 102 is determined to have been disconnected is set to a state in which the resistance increase rate (the increase rate of the resistance value of the conductor 102 relative to the initial resistance value of the conductor 102) of the conductor 102 constituting the cable 10 exceeds 20%, and the disconnection rate of the wires (=disconnection progress state of the conductor 102) at this time is, for example, 80% or more. The disconnection of the conductor 102 is an indicator for determining that the cable 10 has reached the end of its life, and serves as a guide for encouraging replacement of the cable 10. Therefore, the life of the cable 10 can be predicted by predicting the time when the conductor 102 will reach disconnection.

[0016] A robot control device 12 for controlling the industrial robot 11a is connected to the industrial robot 11a. The robot control device 12 is equipped with an operation control unit 12a for controlling the operation of the industrial robot 11a (operation of the movable part 11b). The robot control device 12 stores an operation program (not shown) in which the order of operation of the movable part 11b, the angle of operation, the speed, etc. are preset, and the operation control unit 12a operates the industrial robot 11a according to the operation program.

[0017] (Disconnection detection device 1) The wire breakage detection device 1 is a device that detects breakage of wires in a plurality of insulated electric wires 101 having a conductor 102 composed of a plurality of wires. The wire breakage detection device 1 includes a branching unit 6 and a current ratio detection unit 7 attached in a connector 13 provided on a base unit 11c of an industrial robot 11a, and a computing device 100. The connector 13 to which the branching unit 6 and the current ratio detection unit 7 are attached may be provided in a portion that is connected to an end of a cable 10 that is to be detected for wire breakage. Therefore, the connector 13 may be provided in a portion of the industrial robot 11a other than the base unit 11c (e.g., the movable unit 11b, etc.).

[0018] (Branch 6) The branch portion 6 has a common conductive path 61 and a plurality of branch conductive paths 62 (the same number as the insulated electric wires 101) branched from a tip of the common conductive path 61. One end of the conductor 102 of the corresponding insulated electric wire 101 is electrically connected to each tip of the branch conductive path 62. This allows a current supplied from the common conductive path 61 to be supplied to the plurality of insulated electric wires 101 via the plurality of branch conductive paths 62.

[0019] As shown in Figs. 2(a) and (b), in this embodiment, there are two insulated electric wires 101 to be detected for disconnection. However, the present invention is not limited to this, and there may be three or more insulated electric wires 101 to be detected for disconnection. The cable 10 has two insulated electric wires 101 each having an insulator 103 covering the periphery of a conductor 102, and a sheath 104 covering the two insulated electric wires 101 together. The two insulated electric wires 101 may have the same configuration, and preferably have the same length, the same conductor cross-sectional area, and the same resistance value. The other ends of the two insulated electric wires 101 are connected to the same connection destination. In other words, between the connection destination of the cable 10 and the common conductive path 61, a plurality of (here, two) insulated electric wires 101 and branch conductive paths 62 connected in series are connected in parallel. In other words, the cable 10 can be said to be two insulated electric wires 101 each divided into two in the sheath 104 and covered with an insulator 103.

[0020] In the present embodiment, the branching portion 6 is formed of a bus bar, which is a plate-shaped conductive path, and is formed in a plate shape as a whole. The common conductive path 61 is formed in a substantially rectangular plate shape, and a bolt hole 61a is formed at its base end portion for bolting and electrically connecting a tip end portion of a cable (not shown) from the robot control device 12. The branching portion 6 has two branch conductive paths 62 at the tip end portion (the end portion opposite to the base end portion) of the common conductive path 61, which correspond to the two insulated electric wires 101 to be subjected to disconnection detection. As shown in FIG. 2(a) and FIG. 3, the two branch conductive paths 62 are provided integrally with the common conductive path 61 so as to branch from the tip end portion of the common conductive path 61 in a substantially Y-shape in a plan view. Both branch conductive paths 62 are formed to extend along the long side direction of the common conductive path 61, and bolt holes 62a are formed at the ends of both branch conductive paths 62 for bolting terminals 105 provided at the ends of the insulated electric wires 101, and the ends of both branch conductive paths 62 are electrically connected to the ends of the conductors 102 of the insulated electric wires 101. The two branch conductive paths 62 are formed to have the same shape, and are configured to have the same cross-sectional area, cross-sectional shape, planar shape, and resistance value. As shown in FIG. 3, in a plan view, the branch portions 6 are formed to be linearly symmetrical with respect to a central axis O passing through the center of the common conductive path 61.

[0021] It is possible to appropriately change the specific shape of the branching portion 6. For example, the branching portion 6 does not have to be plate-shaped, and the cross-sectional shape may be a circle, an ellipse, a polygon, or the like.

[0022] (Current ratio detection unit 7) The current ratio detection unit 7 detects the ratio of the currents flowing through the branch conductive paths 62. In this embodiment, the current ratio detection unit 7 is composed of a magnetic sensor 71 arranged between the two branch conductive paths 62. The magnetic sensor 71 is composed of a magnetic detection element such as a Hall element or a GMR (Giant Magneto Resistive effect) element. As shown in FIG. 3, the magnetic sensor 71 is arranged so that its magnetic detection portion 71a is located at the middle position between the two branch conductive paths 62 (a position overlapping with the central axis O). In order to improve the accuracy of detecting a disconnection, it is preferable that the magnetic sensor 71 is arranged so that the magnetic detection portion 71a is located at the center in the thickness direction and width direction of the branch portion 6. In addition, since disturbances occur in the magnetic field near the common conductive path 61 and the tip end portion of the branch conductive path 62 (near the connection portion of the insulated electric wire 101), it is preferable to arrange the magnetic sensor 71 so as to avoid the vicinity of the common conductive path 61 and the tip end portion of the branch conductive path 62.

[0023] As shown in FIG. 4(a), when no wire breakage occurs in either of the two insulated electric wires 101, the currents flowing through both branch conductive paths 62 are equal, and at the magnetic detection portion 71a of the magnetic sensor 71 that is equidistant from both branch conductive paths 62, the magnetic fields generated by the currents flowing through both branch conductive paths 62 cancel each other out. Thus, the magnetic field intensity detected by the magnetic sensor 71 becomes zero. That is, when no wire breakage occurs in either of the two insulated electric wires 101, the ratio of the currents flowing through both branch conductive paths 62 hardly changes from the initial state, and the magnetic field intensity detected by the magnetic sensor 71 hardly changes from the initial state. Thus, it is possible to detect that no wire breakage occurs in either of the two insulated electric wires 101 based on the sensor output of the magnetic sensor 71.

[0024] On the other hand, as shown in FIG. 4(b), when a wire break occurs in one of the insulated electric wires 101, the resistance of the conductor 102 in the insulated electric wire 101 where the wire break occurs increases slightly, causing a difference in the currents flowing through both branch conductive paths 62. As a result, a difference occurs in the magnetic field generated in the magnetic detection unit 71a of the magnetic sensor 71 by the currents flowing through both branch conductive paths 62, and the magnetic field strength (absolute value of the magnetic field strength) detected by the magnetic sensor 71 increases. That is, when a wire break occurs in at least one of the two insulated electric wires 101, the ratio of the currents flowing through both branch conductive paths 62 changes from the initial state, and the magnetic field strength detected by the magnetic sensor 71 also changes from the initial state. Therefore, it is possible to detect that a wire break has occurred in one of the two insulated electric wires 101 based on the sensor output of the magnetic sensor 71.

[0025] Returning to FIG. 2(a), the magnetic sensor 71, which is the current ratio detection unit 7, is mounted on a circuit board 131. The circuit board 131 and the branching portion 6 are arranged so as to overlap in the thickness direction. The circuit board 131 and the branching portion 6 are fixed to each other by a resin fixing member 132 having a clamping portion 132a that clamps the common conductive path 61 in the width direction and a fixing portion 132b that is fixed to the back surface of the circuit board 131. The circuit board 131 is equipped with a circuit that performs signal processing of the magnetic sensor 71, and is provided with a connector portion 131a used for outputting the sensor output of the magnetic sensor 71, etc. The sensor output output from the connector portion 131a is input to the arithmetic device 100. Shield plates 133 are provided on the front and back surfaces of the circuit board 131 via spacers 131b, and the influence of external magnetic fields on the magnetic sensor 71 is suppressed. In FIG. 2(a), the upper shield plate 133 is shown by a dashed line.

[0026] In this embodiment, the magnetic sensor 71 is mounted on the circuit board 131, but the magnetic sensor 71 does not have to be mounted on the circuit board 131. For example, a structure may be used in which a lead frame is punched out at a predetermined position, the magnetic sensor 71 is disposed in the punched portion, and the lead frame and the magnetic sensor 71 are connected by wire bonding or the like.

[0027] In addition, in this embodiment, the magnetic sensor 71 is used as the current ratio detection unit 7, but the current ratio detection unit 7 is not limited to the magnetic sensor 71 and may be anything that can directly detect the ratio (proportion) of the currents flowing through both the branch conductive paths 62. For example, the current ratio detection unit 7 may be configured by an ammeter provided between both the branch conductive paths 62.

[0028] (Arithmetic unit 100) The arithmetic device 100 has a control unit 2 and a storage unit 3. A display unit 4 is connected to the disconnection detection device 1, and various information such as the result of disconnection detection can be displayed on the display unit 4. An input device 5 such as a keyboard is provided in the disconnection detection device 1, and various settings and the display contents of the display unit 4 can be operated by inputting from the input device 5. The display unit 4 may be configured as a touch panel display so that the display unit 4 also functions as the input device 5. Furthermore, the display unit 4 and the input device 5 do not need to be connected to the disconnection detection device 1 by wire, and may be connected wirelessly. In this case, the display unit 4 and the input device 5 may be, for example, a smartphone or a tablet. The arithmetic device 100 may be provided as a arithmetic unit in the robot control device 12.

[0029] The control unit 2 has a data acquisition processing unit 21, a disconnection detection processing unit 22, and a cable life prediction processing unit 23. The data acquisition processing unit 21, the disconnection detection processing unit 22, and the cable life prediction processing unit 23 are realized by appropriately combining a calculation element such as a CPU, memories such as a RAM and a ROM, software, an interface, a storage device, and the like.

[0030] (Data acquisition processing unit 21) The data acquisition processing unit 21 performs a data acquisition process to acquire the sensor output of the magnetic sensor 71 which is the current ratio detection unit 7. The data acquisition processing unit 21 stores the acquired sensor output of the magnetic sensor 71 as sensor output data 31 in the storage unit 3.

[0031] (Disconnection detection processing unit 22) The break detection processing unit 22 performs a break detection process to detect breaks in the wires of multiple (here, two) insulated electric wires 101 based on the detection result of the current ratio detection unit 7, i.e., the sensor output data 31, which is the sensor output data of the magnetic sensor 71 acquired by the data acquisition processing unit 21.

[0032] FIG. 5 is a diagram showing an example of the sensor output of the magnetic sensor 71 before and after a break occurs in the wire. As shown in FIG. 5, before a break occurs in the wire, the magnetic fields from both branch conductive paths 62 cancel each other out, so the magnetic field strength detected by the magnetic sensor 71 is zero, and the sensor output of the magnetic sensor 71 is a constant value (hereinafter referred to as the initial value). When a break occurs in the wire, the magnetic fields from both branch conductive paths 62 become unbalanced, so that the absolute value of the magnetic field strength detected by the magnetic sensor 71 increases, and the sensor output changes from the initial value. The break detection processing unit 22 detects that a break has occurred in the wire (i.e., that an initial break has occurred) based on the change in the sensor output from the initial value. The break detection processing unit 22 may issue an alarm when it detects a break in the wire. The break detection processing unit 22 stores the result of the break detection (determination result) in the storage unit 3 as break detection data 32.

[0033] The greater the number of wire breaks, i.e., the more the break progression progresses, the greater the deviation of the sensor output from the initial value. Therefore, the break detection processing unit 22 may be configured to detect the progress of the break in the conductor 102 based on the detection result of the current ratio detection unit 7 (more specifically, the change in the sensor output from the initial value). When detecting the progress of the break in the conductor 102, a threshold value for the sensor output is preset in stages, and when the value of the sensor output data 31 exceeds the set threshold value, it is possible to detect that the break in the conductor 102 is progressing.

[0034] (Cable life prediction processing unit 23) The cable life prediction processor 23 performs a cable life prediction process to predict the time until the conductor 102 breaks, i.e., the time until the cable 10 reaches the end of its life (hereinafter, referred to as the cable life), based on the detection result of the current ratio detector 7 (more specifically, the change in the sensor output from the initial value). The cable life prediction processor 23 may predict how much time will pass from the present until the cable reaches its end of its life, based on, for example, the period (or the number of operations) from the start of use of the cable 10 until the initial break or a predetermined breakage progression state. The prediction result of the cable life prediction process is stored in the storage unit 3 as life prediction data 33. The cable life prediction processor 23 is not essential and can be omitted.

[0035] (Disconnection detection method) FIG. 6 is a flow diagram of the disconnection detection method according to the present embodiment. The flow in FIG. 6 is started, for example, when the device 11 starts to operate. As shown in FIG. 6, first, in step S1, the data acquisition processing unit 21 starts acquiring data of the sensor output of the magnetic sensor 71. The acquired sensor output data is stored in the storage unit 3 as sensor output data 31. The sensor output data may be acquired continuously throughout the entire period during which the device 11 is operating, or may be acquired at predetermined intervals. The sensor output data may also be acquired during maintenance work or the like during the period during which the device 11 is not operating. By acquiring the sensor output data during the period during which the device 11 is operating, the progress of the disconnection of the conductor 102 according to the operating state of the device 11 can be detected.

[0036] Then, in step S2, a disconnection detection process is performed. In the disconnection detection process, the disconnection detection processing unit 22 detects whether a disconnection has occurred in the wire (whether a disconnection of the wire has started to occur) based on the sensor output acquired in step S1. For example, an initial value of the sensor output is stored in advance, and when the difference between the initial value and the sensor output becomes larger than a predetermined threshold, it is possible to detect that the wire has been disconnected. In addition, in step S2, it is also possible to detect whether the conductor 102 has reached a desired disconnection progression state by, for example, appropriately adjusting the threshold. The detection result is stored in the storage unit 3 as disconnection detection data 32. Although not shown, in the disconnection detection process, the result of the disconnection detection may be displayed on the display 4, or an alert may be issued when a disconnection of the wire is detected. In addition, the disconnection detection data 32 obtained in the disconnection detection process may be used to acquire other data for managing the state of the cable 10. For example, the robot controller 12 may be configured to start capturing images of the operating status of the cable 10 wired to the industrial robot 11a with a camera or the like when the disconnection detection data 32 exceeds a predetermined threshold, and to perform an imaging process in which the data captured during a predetermined period (imaging data) is stored in a storage unit of the robot controller 12 or a computing device. Using the imaging data stored in the storage unit, the operation of the industrial robot 11a can be stopped or the cable 10 can be replaced.

[0037] Thereafter, in step S3, it is determined whether the operation of the device 11 has been completed. If the determination in step S3 is NO, the process returns to step S2. If the determination in step S3 is YES, in step S4, data acquisition by the data acquisition processing unit 21 is terminated, and the process is then terminated. Although not shown in the figure, a cable life prediction process may be performed after step S4.

[0038] (Modification) Although not mentioned in this embodiment, even if no break occurs in the wire, it is considered that the sensor output of the magnetic sensor 71 will not be strictly zero due to various reasons such as manufacturing errors in the branching portion 6. In this case, it is preferable to detect the break in the wire based on the change in the sensor output compared to the normal state (the state before the break occurs in the wire).

[0039] In addition, in this embodiment, the branch conductive paths 62 and the insulated wires 101 have the same configuration so that the currents flowing through the branch conductive paths 62 are equal, but the present invention is not limited to this, and the branch conductive paths 62 and the insulated wires 101 may have different configurations. In this case, the output of the magnetic sensor 71 will not be zero even when there is no break in the wire, but as described above, it is possible to detect a break in the wire based on the change in the sensor output relative to the normal state (the state before the break in the wire occurs).

[0040] In the present embodiment, two insulated electric wires 101 are subject to disconnection detection, but three or more insulated electric wires 101 may be subject to disconnection detection. For example, as shown in FIG. 7(a), when a cable 10a having four insulated electric wires 101 is subject to disconnection detection, two branch portions 6 and a magnetic sensor 71 may be aligned in the thickness direction of the branch portion 6 (perpendicular to the arrangement direction of the branch conductive paths 62 and the longitudinal direction of the branch conductive paths 62) as shown in FIG. 7(b). This prevents, for example, a current flowing through the upper branch portion 6 from affecting the detection by the lower magnetic sensor 71. The distance between the branch portions 6 may be set to a level that provides sufficient insulation.

[0041] Similarly, when a cable 10b having four pairs of twisted wires 106, i.e., eight insulated wires 101, is to be subjected to disconnection detection as shown in Fig. 8(a), it is advisable to use four branching parts 6 and magnetic sensors 71 corresponding to the respective twisted wires 106 and align them in the thickness direction as shown in Fig. 8(b). Note that by using the twisted wires 106, it is possible to further reduce the influence of external noise.

[0042] Furthermore, although not mentioned in this embodiment, it is also possible to detect a breakage in consideration of the operating frequency of the movable part 11b of the device 11. When the movable part 11b operates in a state where a breakage has occurred in the strand, the distance of the broken part (the distance between the broken strands) expands and contracts in response to the operation, and the resistance value of the conductor 102 varies in response to the operation of the movable part 11b. Therefore, it is possible to detect a breakage of the strand and a progress state of the breakage of the conductor 102 based on the operating frequency component (or its higher frequency component) obtained by performing frequency analysis on the measured sensor output by measuring the time-series change in the sensor output (the ratio of the currents flowing through both branched conductive paths 62) while the movable part 11b is operated at a constant cycle.

[0043] (Functions and Effects of the Embodiments) As described above, the disconnection detection device 1 of this embodiment has a common conductive path 61 and a plurality of branch conductive paths 62 arranged to branch off from the tip of the common conductive path 61, and is equipped with a branch section 6 to which one end of the conductor 102 of a corresponding insulated wire 101 is electrically connected to each of the tips of the branch conductive paths 62, a current ratio detection section 7 capable of detecting the ratio of currents flowing through the plurality of branch conductive paths 62, and a disconnection detection processing section 22 that detects disconnection of wires in the plurality of insulated wires 101 based on the detection result of the current ratio detection section 7.

[0044] With this configuration, it is possible to detect with high sensitivity the breakage of the wires and the progress of the breakage of the conductor 102 based on the ratio of the currents flowing through the branch conductive paths 62. Furthermore, in this embodiment, it is possible to detect the breakage of the wires of the conductor 102 constituting the cable 10 wired to the device and the progress of the breakage, even without a reference such as a current value. As a result, it is possible to accurately predict the time to replace the cable 10.

[0045] (Summary of the embodiment) Next, the technical ideas grasped from the above-described embodiment will be described by using the reference numerals and the like in the embodiment. However, the reference numerals and the like in the following description do not limit the components in the claims to the members and the like specifically shown in the embodiment.

[0046] [1] A device for detecting a break in a wire in a plurality of insulated electric wires (101) having a conductor (102) composed of a plurality of strands, the device comprising: a common conductive path (61) and a plurality of branch conductive paths (62) arranged to branch off from a tip of the common conductive path (61), the device comprising: a branch section (6) to which one end of the conductor (102) of a corresponding insulated electric wire (101) is electrically connected to a tip of each of the branch conductive paths (62); a current ratio detection section (7) capable of detecting a ratio of currents flowing through the plurality of branch conductive paths (62); and a wire break detection processing section (22) that detects a break in the wire in the plurality of insulated electric wires (101) based on a detection result of the current ratio detection section (7). [2] The wire breakage detection device (1) described in [1], wherein the other ends of the multiple insulated electric wires (101) are connected to a same connection destination, and the insulated electric wires (101) and the branch conductive paths (62) that are connected in series are connected in parallel between the connection destination and the common conductive path (61).

[0047] [3] The disconnection detection device (1) described in [1], wherein the branch portion (6) has two of the branch conductive paths (62), and the current ratio detection unit (7) is composed of a magnetic sensor (71) arranged between the two branch conductive paths (62).

[0048] [4] The disconnection detection device (1) according to [3], wherein the branch portion (6) is constituted by a bus bar.

[0049] [5] The disconnection detection device (1) described in [4], wherein the two branch conductive paths (62) have the same shape, and the two insulated electric wires (101) connected to the two branch conductive paths (62) have the same configuration, and the magnetic sensor (71) is arranged so that its magnetic detection portion (71a) is positioned midway between the two branch conductive paths (62).

[0050] [6] A disconnection detection device (1) as described in [4], having a plurality of branch portions (6) and magnetic sensors (71) aligned in a direction perpendicular to the arrangement direction of the branch conductive path (62) and the longitudinal direction of the branch conductive path (62).

[0051] [7] The disconnection detection device (1) described in [1], wherein the disconnection detection processing unit (22) detects a progress state of the disconnection of the conductor (102) based on a detection result of the current ratio detection unit (7).

[0052] (Additional Note) Although the embodiment of the present invention has been described above, the invention according to the claims is not limited to the embodiment described above. It should be noted that not all of the combinations of features described in the embodiment are essential to the means for solving the problems of the invention. The present invention can be modified appropriately without departing from the spirit of the invention. [Explanation of symbols]

[0053] 1...Disconnection detection device 2...Control section 21...Data acquisition processing section 22...Disconnection detection processing unit 23…Cable life prediction processing unit 3...Storage section 31...Sensor output data 32...Disconnection detection data 33…Life expectancy data 6…Branch 61...Common conductive path 62...Branch conductive path 7…Current ratio detection section 71...Magnetic sensor 71a...magnetic detection unit 10…Cable 101...Insulated wire 102...Conductor 103...Insulator 104…Sheath 13…Connector 131...Circuit board

Claims

1. A device for detecting breaks in a plurality of wires in an insulated electric wire having a conductor made of a plurality of wires, comprising: a branch portion including a common conductive path and a plurality of branch conductive paths branched from a tip end of the common conductive path, and one end of the conductor of the insulated electric wire is electrically connected to each tip end of the branch conductive path; a current ratio detection unit capable of detecting a ratio of currents flowing through the plurality of branch conduction paths; and a break detection processing unit that detects breaks in the wires of the plurality of insulated wires based on a detection result of the current ratio detection unit. Disconnection detection device.

2. The other ends of the multiple insulated wires are connected to a same connection destination, a plurality of the insulated electric wires and the branch conductive paths connected in series are connected in parallel between the connection destination and the common conductive path; The disconnection detection device according to claim 1 .

3. The branch portion has two of the branch conductive paths, The current ratio detection unit is composed of a magnetic sensor disposed between the two branch conductive paths. The disconnection detection device according to claim 1 .

4. The branch portion is constituted by a bus bar. The disconnection detection device according to claim 3.

5. the two branch conductive paths have the same shape, and the two insulated electric wires connected to the two branch conductive paths have the same configuration; The magnetic sensor is disposed so that a magnetic detection portion thereof is located at a midpoint between the two branch conductive paths. The disconnection detection device according to claim 4.

6. a plurality of the branch portions and the magnetic sensors are aligned in a direction perpendicular to an arrangement direction of the branch conductive paths and a longitudinal direction of the branch conductive paths; The disconnection detection device according to claim 4.

7. The disconnection detection processing unit detects a disconnection progression state of the conductor based on a detection result of the current ratio detection unit. The disconnection detection device according to claim 1 .

Images