JP2020042896A - cable - Google Patents

Abstract

To provide a cable making it possible to improve detection accuracy of disconnection of a conductor disposed in the cable.SOLUTION: A cable 1 includes a semi-disconnection detection mechanism to detect semi-disconnection of a conductor 13. The semi-disconnection detection mechanism includes a thermal deformation member 11 that deforms due to a temperature change, and an indication part 16 to indicate detected semi-disconnection. Upon occurrence of the semi-disconnection of the conductor 13, the thermal deformation member 11 deforms and the indication part 16 is activated by deformation of the thermal deformation member 11.SELECTED DRAWING: Figure 4

Description

  The present invention relates to cables.

  A multi-core cable having a plurality of conductors inside the cable may be partially broken or broken due to bending or the like. Patent Literature 1 discloses a cable for a robot in which a conductor for driving and controlling a robot and another conductor having lower durability than the conductor are provided in a cable body. According to Patent Literature 1, it is possible to predict a disconnection time of a conductor for driving a robot by disconnecting a conductor having low durability first.

JP-A-63-026907

  In Patent Literature 1, a conductive wire having low durability is formed by mechanically twisting with respect to another conductive wire. However, in this method, since the load applied to each conductor is not uniform depending on the arrangement and usage of the cables, there is a problem that the conductor having low durability is not always disconnected first, and the accuracy of detecting the disconnection is low. .

  The present invention has been made in view of the above problems, and has as its object to provide a cable capable of improving the detection accuracy of disconnection of a conductor.

  A cable according to the present invention is a cable including a half-break detection mechanism for detecting a half-break of a conductor, wherein the half-break detection mechanism includes a heat-deformable member that deforms due to a temperature change and a notification that notifies the detected half-break. When the conductor is partially broken, the heat-deformable member is deformed, and the deformation of the heat-deformed member activates the notification unit.

  In the cable according to the present invention, when the conductor is partially broken, the resistance value of the partially broken portion increases, and heat is generated. When the heat-deformed member deforms due to the heat generation, the notification unit operates.

  ADVANTAGE OF THE INVENTION According to this invention, the cable which can improve the detection accuracy of a disconnection of a conductor can be provided.

FIG. 3 is a schematic front sectional view showing a normal state of the cable according to the first embodiment. FIG. 2 is a schematic sectional view taken along line II-II in FIG. 1. 4 is a flowchart showing a series of flows for detecting and notifying a half-break of the cable according to the first embodiment. FIG. 4 is a schematic front sectional view showing a state in which the cable according to the first embodiment is partially disconnected. FIG. 13 is a schematic front sectional view showing a normal state of the cable according to the second embodiment. 10 is a flowchart showing a series of flows for detecting and notifying a semi-disconnection of the cable according to the second embodiment. FIG. 13 is a schematic front sectional view showing a state in which the cable according to the second embodiment is partially disconnected. FIG. 21 is a schematic diagram showing an example of applying the cable according to the fifth embodiment to a robot.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.
Note that the right-handed xyz coordinates shown in FIGS. 1 to 2, 4 to 5, and 7 are for convenience in describing the positional relationship of the components. In the present invention, the axial direction of the cable is an x-axis, and a plane perpendicular to the x-axis is a yz plane.

  “Semi-disconnection” in this specification means that the resistance value of the conductor increases. The increase in the resistance value is caused by, for example, conductor stretching or minute cracks caused by bending of a cable or the like. When a half-break occurs, the resistance value of the half-break portion increases, thereby increasing the amount of heat generated.

<First Embodiment>
Hereinafter, the cable according to the first embodiment will be described with reference to FIGS.
FIG. 1 is a schematic front sectional view showing a normal state of the cable according to the first embodiment. The "normal state" of the cable is a state in which the conductor included in the cable has no breakage and is conducting. The cable 1 according to the present embodiment is a harness cable including a connector on the cable.

As shown in FIG. 1, the cable 1 including the half-break notification mechanism includes a heat-deformable member 11 and a conductor 13 and an insulator 14 in order from the center. Other configurations such as an outer wire 12 disposed therebetween and a coating (not shown) covering the conductor 13 may be provided. Both ends of the cable 1 are provided with connectors 15. When the cable is used, the conductor 13 forms a robot control / drive circuit (not shown) via the connector 15. One end of the connector 15 includes a notifying unit 16 for notifying the occurrence of a half-break. Among them, the thermal deformation member 11 and the notification unit 16 function as a half-break notification mechanism.
In the example of FIG. 1, the insulator 14 and the connector 15 are not connected, but the insulator 14 and the connector 15 may be integrated.

The thermally deformable member 11 is a member that can be deformed by heating due to heat generated by a semi-disconnected conductor. In the present embodiment, it is a conductive member. Examples of the thermally deformable member 11 include a bimetal in which two metals having different coefficients of thermal expansion are bonded to each other, and other metals. It is preferable that the heat-deformable member 11 has a wire shape (column shape) that can be arranged in parallel with the conductor 13 in a state before the heat deformation. It is preferable that the heat deformable member 11 contracts or expands in the axial direction by heating. In the first embodiment, the thermally deformable member 11 contracts in the axial direction.
As a material that contracts in the axial direction, for example, “Biometal (registered trademark)” (manufactured by Toki Corporation) can be used. Since Biometal (registered trademark) shrinks by heating at about 70 ° C., it can be deformed by heat generated by a semi-disconnected conductor. The raw material of Biometal (registered trademark) is a Ti-Ni-based shape memory alloy.

  As shown in FIG. 1, one end 11 a of the heat deformation member 11 is fixed to an insulator 14. On the other hand, the other end 11b of the heat deformable member 11 is in contact with the electrode 16a in a state where it can slide in the axial direction (positive x-axis direction) when contraction due to heating occurs.

  The outer wire 12 may be disposed between the heat deformable member 11 and the insulator 14 as needed. The outer wire 12 is arranged in order to secure the slidability when the heat deformable member 11 is deformed, and has a small friction with the heat deformable member 11. The outer wire 12 includes, for example, a wire in which a spirally wound metal wire is disposed on a contact surface with the heat deformable member 11. According to the metal wire, the friction with the heat deformable member 11 can be reduced, and the metal wire has flexibility that can cope with the bending of the cable 1.

  The conductor 13 is a conductive wire having conductivity, and is disposed in the cable 1 in the axial direction. At least one conductor 13 may be provided, and a plurality of conductors 13 may be provided as in the example of FIG. The conductors 13 are arranged so as to be electrically connectable to other members via connectors 15 arranged at both ends of the cable 1. The material of the conductor 13 may be any material known as a conductive wire, and is usually a metal, for example, a copper wire or a tin-plated wire. Further, each conductor 13 may be protected by an insulating protective film (not shown).

  The insulator 14 is a tubular outer coating (sheath) and protects the conductor 13 and the like. It is preferable that the material of the insulator 14 has durability and flexibility capable of coping with bending. The material is, for example, rubber, chloroprene rubber, polyvinyl chloride, polyethylene, or Teflon (registered trademark). Although a tubular sheath is used in the present embodiment, the present invention is not limited to this. As long as the conductor 13 can be protected, for example, an insulating tape or the like may be used.

  Here, the positional relationship among the heat deformable member 11, the outer wire 12, the conductor 13, and the insulator 14 will be described with reference to FIG.

  FIG. 2 is a schematic sectional view taken along the line II-II in FIG. As shown in FIG. 2, the heat deformable member 11 of the cable 1 is located at the center and is covered by the outer wire 12. The conductors 13 are arranged further outside the outer wire 12, and four conductors are arranged as an example in FIG. The number of the conductors 13 can be appropriately changed depending on the type of a desired cable. An insulator 14 is provided so as to cover the plurality of conductors 13. As shown in FIG. 2, the insulator 14 protects the heat deformable member 11, the outer wire 12, and the conductor 13.

Hereinafter, the connector 15 and the notification unit 16 will be described with reference to FIG. 1 again.
As shown in FIG. 1, the connector 15 is a component for connecting the cable 1 to various devices and the like. In this embodiment, the connector 15 is provided on both the positive side and the negative side of the cable 1 on the x-axis. Have been. In the present embodiment, the connector 15 on the negative side of the x-axis includes the notifying unit 16 for notifying the occurrence of the partial disconnection.

  The notification unit 16 notifies that the conductor 13 has been partially broken. The notification unit 16 includes an electrode 16a that is in contact with the heat deformable member 11 in a normal state, a circuit 16b including a power supply, and a notification unit 16c. FIG. 1 illustrates an LED (light emitting diode) as an example of the notification unit 16c, but the notification unit 16c is not limited to this. As the notification unit 16c, for example, a notification by a communication input terminal, wireless communication, sound, or the like may be used, or these may be used in combination including an LED. An example in which a communication input terminal is used as the notification unit 16c will be described later in a fifth embodiment.

  As shown in FIG. 1, when the cable 1 is in a normal state, that is, when the conductor 13 has not been partially broken, the circuit 16 b is in a state of being electrically connected via the heat deformation member 11. Therefore, when the conductor 13 of the cable 1 has not been partially broken, the LED of the notification unit 16c is lit.

Next, with reference to the flowchart of FIG. 3 and the cross-sectional view of FIG. 4, a description will be given of a series of flows for detecting and notifying a half-break of the cable 1 according to the present embodiment.
FIG. 3 is a flowchart showing a series of flows for detecting and notifying a half-break of the cable according to the first embodiment.
FIG. 4 is a schematic front sectional view showing a state in which the cable according to the first embodiment is partially disconnected.

As shown in FIGS. 3 and 4, when a half-break PD occurs in the conductor 13 of the cable 1 (Step S1), the resistance value of the conductor 13 increases (Step S2).
When the resistance value of the conductor 13 increases, heat is generated in the half-disconnected line PD (step S3). In FIG. 4, the manner in which heat generated from the half-disconnected line PD portion is transmitted is indicated by downward black arrows.

When the heat generated in the half-break PD portion is transmitted to the heat deforming member 11, one end 11a of the heat deforming member 11 is fixed to the insulator 14, so that the heat deforming member 11 is moved in the axial direction (the positive x-axis direction, the white direction). (Step S4).
Due to the contraction of the heat deformable member 11, the heat deformable member 11 is pulled out of the electrode 16a, and the circuit 16b is disconnected from the physical connection and the electric connection, and is disconnected (step S5). As a result, the LED of the notification means 16c is turned off (step S6). As described above, in the present embodiment, the occurrence of the semi-disconnected PD can be known by turning off the LED of the notifying unit 16c.

  Conventionally, it is said that when a conductor having low durability is disconnected first, the disconnection time of a conductor for driving a robot can be predicted. A conductor having low durability is formed by mechanically twisting with respect to other conductors. However, in this method, since the load applied to each conductor is not uniform depending on the arrangement and usage of the cables, there is a problem that the conductor having low durability is not always disconnected first, and the accuracy of detecting the disconnection is low. .

  In the present embodiment, a heat deformation member and a notification unit are provided as a half-break notification mechanism inside the cable. When the conductor of the cable is partially broken, the resistance value of the half-broken portion increases and heat is generated. When the heat-deformed member deforms due to the heat generation, the notification unit operates. Therefore, a sign of disconnection can be detected at the time when a partial disconnection occurs, so that the detection accuracy of disconnection can be improved. Further, in the present embodiment, in order to detect a half-break, there is no need to attach a large device as compared with the half-break notification mechanism of the present invention, such as a tester, a signal oscillator or a voltage measuring device, and the half-break notification mechanism is provided. It is easy to arrange so as to be woven into the cable.

<Embodiment 2>
Hereinafter, the cable according to the second embodiment will be described with reference to FIGS.
FIG. 5 is a schematic front sectional view showing a normal state of the cable according to the second embodiment. As shown in FIG. 5, the cable 2 including the half-break notification mechanism according to the present embodiment includes, in order from the center, a heat deformable member 21, an outer wire 12, a conductor 13, and an insulator 14. Both ends of the cable 2 are connectors. 25. One end of the connector 25 includes a notifying unit 26 for notifying the occurrence of a half-break. The heat deformable member 21 includes an insulating part 21c.

  In Embodiment 1 described above, the electrode 16a of the notifying section 16 and the thermally deformable member 11 were in contact with each other in the normal state, whereas in Embodiment 2, the electrode 26a of the notifying section 26 was thermally deformed. The insulating portion 21c of the member 21 is sandwiched, and a force toward the center of the cable 2 is applied to the electrode 26a by a spring or the like (not shown). In other words, the insulating portion 21c is inserted between the electrodes 26a, and when the insulating portion 21c is pulled out, the electrodes 26a are in a conductive state. The configuration other than the above is the same as that of the first embodiment.

  Specifically, as shown in FIG. 5, when the cable 2 is in a normal state, that is, when the conductor 13 is not partially broken, the electrode 26a holds the insulating portion 21c, and the circuit 26b is connected to the insulating portion 21c. It is in a state of being electrically disconnected by 21c. Therefore, when the cable 2 is not partially broken, the circuit 26b is electrically disconnected and the LED of the notifying unit 26c is turned off.

Next, with reference to a flowchart of FIG. 6 and a cross-sectional view of FIG. 7, a description will be given of a series of flows for detecting and notifying a partial disconnection of the cable 2 according to the present embodiment.
FIG. 6 is a flowchart showing a series of flows for detecting and notifying a half-break in the cable according to the second embodiment.
FIG. 7 is a schematic front sectional view showing a state in which the cable according to the second embodiment is partially disconnected.

As shown in FIGS. 6 and 7, when a half-break PD occurs in the conductor 13 of the cable 2 (Step S1), the resistance value of the conductor 13 increases (Step S2).
When the resistance value of the conductor 13 increases, heat is generated in the half-disconnected line PD (step S3). In FIG. 7, the manner in which heat is transmitted is indicated by downward black arrows.

When the heat generated in the half-disconnected line PD portion is transmitted to the thermal deformation member 21, the one end 11a of the thermal deformation member 21 is fixed, so that the thermal deformation member 21 moves in the axial direction (x-axis positive direction, outlined arrow). Shrinking sliding occurs (step S4).
Due to the contraction of the thermal deformation member 21, the insulating portion 21c is pulled out of the electrode 26a, the electrodes 26a are electrically connected to each other, and the circuit 26b is conducted (step S5). As a result, the notification means 26cLED is turned on (step S6). As described above, in the present embodiment, the occurrence of the half-disconnection PD can be known by turning on the LED of the notifying unit 26c.

  Hereinafter, Embodiments 3 and 4 will be described. In the first and second embodiments, a member that contracts in the axial direction by heating is used as the thermally deformable member. In the third and fourth embodiments, a member that expands in the axial direction by heating is used. A known bimetal can be used as the member extending in the axial direction.

<Embodiment 3>
The normal state of the present embodiment will be described in comparison with the first embodiment. In the present embodiment, a member that extends in the axial direction by heating is used as the thermally deformable member. In a normal state, the heat deformable member is arranged without being connected to the electrode as shown in the example of FIG. Other points are the same as the first embodiment.
In the present embodiment, the heat is generated by the semi-broken conductor, the heat-deformable member extends in the axial direction (x-axis negative direction), and the conductive member is inserted between the electrodes to be electrically connected. The part operates.

<Embodiment 4>
The normal state of the present embodiment will be described in comparison with the second embodiment. In the present embodiment, a member that extends in the axial direction by heating and has an insulator disposed at an end on the electrode side is used as the heat deformable portion. In a normal state, the heat deformable member is arranged in a state where it is not connected to the electrode as shown in the example of FIG. 7, and two electrodes which receive a force in the center direction by a spring or the like are electrically connected. It is arranged in the state where it was. Other points are the same as the second embodiment.
In the present embodiment, the heat generated by the determined conductor causes the heat-deformable member to extend in the axial direction (x-axis negative direction) and the insulator to be inserted between the electrodes to be electrically cut off. Operates.

<Embodiment 5>
Hereinafter, the fifth embodiment will be described with reference to FIG.
FIG. 8 is a schematic diagram showing an application example of the cable according to the fifth embodiment to a robot. As shown in FIG. 8, the robot 100 includes a cable a between the relay box 111 and the relay box 112. Further, the robot 100 includes a cable b between the relay box 112 and the robot control panel 113. The cable a and the cable b are different from the cables of the first to fourth embodiments in that the notification unit of the notification unit is changed from the LED to the communication input terminal.

  When a half-break occurs in the cable a between the relay box 111 and the relay box 112, a signal indicating that the half-break has occurred is input to a communication input terminal provided in the relay box 111. Similarly, when a half-break occurs in the cable b between the relay box 112 and the robot control panel 113, a signal indicating that the half-break has occurred is input to a communication input terminal provided in the relay box 112. . The user of the robot 100 can monitor and confirm the signals input to the respective communication input terminals of the relay box 111 and the relay box 112 on the robot control panel 113.

  In the case where the cable according to the first embodiment is used, the circuit is conducting in a normal state, so that the signal input from the communication input terminal is always returned. On the other hand, when a half-break occurs, the heat-deformable member is deformed and the circuit does not conduct, so that the signal input from the communication input terminal does not return, indicating that a half-break has occurred in the cable.

  In the case of using the cable according to the second embodiment, no signal is transmitted / received from the communication input terminal because the circuit is not conducting in a normal state. On the other hand, when a half-break occurs, the thermal deformation member is deformed and the circuit becomes conductive, so that a signal input from the communication input terminal is returned, indicating that a half-break has occurred in the cable.

  Further, in this embodiment, in addition to the communication input terminal, for example, an LED, a sound, or the like can be used in combination as communication means. As an example, a case where LEDs are used together will be described. When receiving a signal indicating that the robot control panel 113 has been partially broken, the robot user opens the relay box 111 or 112 and checks whether the internal LED is on or off. That is, when a half-break occurs, a double check can be performed with the signal and the LED, so that the presence or absence of the half-break can be more reliably confirmed. In addition, the material of the relay boxes 111 and 112 is preferably made of metal from the viewpoint of waterproofing and dustproofing. However, depending on the environment in which the robot operates, a part or the whole is made transparent with an acrylic plate or the like so that the LED can be seen from the outside. Such a configuration can also be adopted.

  In many cases, a robot uses a plurality of cables for controlling the robot. In such a case, conventionally, in order to monitor the disconnection, measurement of a change in a voltage value or measurement of a signal is performed while passing through a plurality of cables. It was difficult to specify by one measurement. On the other hand, in the present embodiment, a cable having a disconnection notification mechanism is provided for each relay box. Therefore, by using the cable having the disconnection notification mechanism according to the present embodiment, it is easy to specify which cable has the disconnection.

  It should be noted that the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist.

1, 2, a, b Cable 11, 21 Thermal deformation member 11a, 21a One end 11b Other end 12 Outer wire 13 Conductor 14 Insulator 15, 25 Connector 16, 26 Notification part 16a, 26a Electrode 16b, 26b Circuit 16c, 26c Notification Means 21c Insulating part 100 Robot 111, 112 Relay box 113 Robot control panel

Claims (1)

A cable having a half-break detection mechanism for detecting a half-break of a conductor,
The half-break detection mechanism,
A thermally deformable member that is deformed by temperature changes;
A notification unit for notifying the detected half-break,
When the semi-disconnection of the conductor occurs, the heat deformable member is deformed, and the notification unit is operated by the deformation of the heat deformable member.
cable.

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