JP2508629Y2 - Cable damage detector - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention is designed to detect wear and damage of a cable when a cable for power supply and a signal used for an industrial robot or the like is inserted into a cable holding tube. Related to the device.

[Prior Art] A cable connected to a movable part that rapidly swings like the movement of a swivel arm or a hand in an industrial robot is a robot base 11 as shown in the example of the robot in FIG. It is connected to the arm 12 rotatably attached to the
The flexible outer sheath of the cable is used in order to prevent the robot from following the movement of the moving part and not hindering the movement of the moving part. In order to reduce the size of the cable, a cable holding tube 14 which is formed in a coil spring shape and through which a cable is inserted is provided.

In general, a cable provided with a detection line in order to detect the damage to the outer jacket of the cable is disclosed in, for example, Japanese Patent Publication No. 63-49.
As shown in No. 326, etc., the detection wire is mixed with the insulation wire of the insulation cable to provide the detection wire, and the lead wire is provided in the cable to monitor the change in resistance value due to the cutting disconnection of the detection wire. There is.

Also, in Japanese Utility Model Laid-Open No. 63-150427, a layer in which a semiconductive layer and a metal material are combined is provided outside the cable sheath, and a megger is provided between the metal material (metal braid wire) and the braid shield inside the sheath. A moving cable for movement that enables measurement of sheath insulation resistance with a tester or the like and detection of external damage is shown.

[Problems to be solved by the invention] However, in all of these, resistance change is detected by the configuration of the cable itself, but the sheath of the cable sheath is made flexible and is inserted into the coil spring-shaped cable holding tube. Then, when the movement of the movable part is performed rapidly and frequently,
Each time the cable bends during rocking, the cable holding tube comes into contact with the outer surface of the sheath, and the friction may abrade the sheath, which may cause insulation breakdown of the insulated wire inside, and it is necessary to detect wear damage to the sheath. Especially, when used in a gas atmosphere, there is a risk of causing a serious accident.
Further, in order to prevent such an accident, when conventionally detecting the damage of the cable by cutting the detection line, there is a drawback that it takes time until the detection line is cut by friction, and the detection is delayed.

[Means for Solving the Problems] In view of this point, the present invention has a flexible sheath on the outer periphery of an inclusion in which a plurality of insulated wires are embedded, and is inserted and held in a cable holding tube made of a coil spring-like conductive wire. In the cable to be made, a conductive detection conductor that surrounds inclusions is provided inside the sheath of the cable over the entire length, and the detection conductor led out from the cable end and a detector connected between the cable holding tube and the sheath are provided. The electric circuit of the detector is closed by the contact between the cable holding tube and the detection conductor due to wear of the detector.

[Effect] Therefore, when the cable and the cable holding tube are in sliding contact with each other due to the deflection of the cable and the sheath of the cable is worn by friction, the holes formed in the sheath cause the conductive wire forming the cable holding tube to move inside the sheath. Contacting the sensing conductors closes the electrical circuit and the detector operates to detect sheath damage.

[Embodiment] FIG. 1 shows an embodiment of a cable, a cable holding tube and a detection circuit according to the present invention. The upper half of the cable is shown in a side sectional view and the lower half is shown in a cutaway view. Reference numeral 10 is a cable, 1 is an insulated wire for operating a robot stored in the cable 2, 2 is an insulating inclusion packed between a plurality of insulated wires, and 3 is a spiral winding surrounding the outer circumference of the inclusion. The rotating detection conductor is composed of a tape with an outer surface coated with a conductive material such as copper powder. A flexible sheath 4 covers the detection conductor 3 and is made of polyurethane rubber. 5 is a power source, 6
Is a detector, and 14 is a cable holding tube.

When the cable 10 swings following the movement of the arm 12 and the hand 13, the cable 10 slides against the cable holding tube 14 surrounding the cable and wears the sheath 4. If a hole A is formed in the sheath 4 as shown in FIG. 1 due to this abrasion, the cable holding tube 14 on the shake direction side comes into contact with the detection conductor 3 when the cable 10 shakes, and an electric circuit is formed from the power source 5 through the ground. It is closed and the detector 6 such as an indicator lamp is operated. Therefore, the sheath 4
The damage of the cable 10 is detected by the detector 6 at the time when a small hole is formed in the.

The detection conductor 3 is not limited to the tape-shaped one shown in the figure, but may be formed by winding a bare conductor, or a braided or foil-shaped conductor.

[Effects of the Invention] As described above, the present invention relates to a cable having a flexible sheath on the outer periphery of an inclusion in which a plurality of insulated electric wires are embedded and inserted and held in a cable holding tube made of a coil spring-shaped conductive wire. A conductive detection conductor that surrounds inclusions is provided over the entire length inside the sheath of the cable, and the detection conductor led out from the cable end and the detector connected between the cable holding tube are provided, so that the cable The movement operation can be held smoothly without impairing the flexibility, and cable damage is detected by closing the electric circuit via the cable holding tube. The contact between the cable and the cable holding tube is ensured, the detection accuracy is good, the damage to the sheath can be detected early, and the detection device can be simplified. It has the effect of being able to.

[Brief description of drawings]

FIG. 1 is a side sectional view and a detection circuit diagram of a cable and a cable holding tube in an embodiment of the present invention, and FIG. 2 is II of FIG.
FIG. 3 is a side view showing an example of an industrial robot, which is a sectional view taken along line II. 1 is an insulated wire, 2 is an inclusion, 3 is a detection conductor, 4 is a sheath, 5 is a power supply, 6 is a detector, 10 is a cable, 11 is a base,
12 is an arm, 13 is a hand, and 14 is a cable holding tube.

Claims (1)

(57) [Scope of utility model registration request] 1. A cable in which a flexible sheath is provided on the outer periphery of an inclusion in which a plurality of insulated electric wires are embedded, and which is inserted and held in a cable holding tube formed of a coil spring-shaped conductive wire, the interposition being inside the sheath of the cable. A cable damage detection device comprising a conductive detection conductor surrounding an object over the entire length, and a detector connected between the detection conductor led out from the cable end and the cable holding tube.