JPH04201193A - Cable handling device on industrial robot - Google Patents

Abstract

PURPOSE:To solve generation of torsion of a cable by so constituting that an excess length cable portion in the shape of the letter U is wound or rewound according to rotation of an arm joint and a cylindrical cable supporting drum. CONSTITUTION:A cable 20 for wiring passing a joint part 14 winds around a cable supporting drum 24 and hangs and further extends downward with an excess length portion in a robot arm 10. Thus, when the supporting drum 24 synchronized with rotation of the robot arm 10 is rotated, the cable 20 for wiring is wound around the supporting drum 24 or re-wound. Therefore, only the excess length portion is moved up or down in the robot arm 10, and the cable 20 for wiring does not affect the outside space at all by rotation of the robot arm 10.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a cable handling device for an industrial robot.
In particular, the present invention relates to a processing device for a cable passing through two arm joints.

[Prior art]

In an industrial robot, a plurality of movable elements, such as a robot torso, a robot arm, a wrist, and a hand, are sequentially connected to a robot base, which is an installation element, via rotation joints, and each movable element is The elements have a structure in which they perform operations such as turning, swinging, and linear motion by a drive source that operates according to commands from a robot control device. Therefore, each drive source requires electrical wiring, and cables are routed from the robot base side to the robot wrist. Modern industrial robots have an exposed cable structure in which the cables are taken inside the robot body, and the wiring cables are exposed on the outside surface of the robot body. Although there is a tendency to disappear from the viewpoint of avoiding interference with other objects and aesthetically pleasing appearance, there are some robot body structures that do not have a structure that penetrates the center of the joint at the joint, and parts of the joint are exposed to the outside. In some cases, a wiring structure was adopted.

For example, FIG. 3 shows a cable wiring structure at a connecting joint between an upper arm and a forearm in an articulated robot. That is, after the wiring cable 2 that has passed through the inside of the upper arm 1 is held down by a cable stopper (I!l not shown) at the upper end of the upper arm 1, the extra length portion 2a is exposed to the outside of the joint 4.
Next, it enters the inside of the forearm 5 through the cable window 6 opened at the lower end of the forearm 5, and after being held down again by the clasp 3 near the cable window 6, the inside of the forearm 5 is turned toward the wrist (not shown). It has a wired structure.

[Problems to be Solved by the Invention] However, as is clear from the above-mentioned conventional example, the table treatment at the joint portion is simply provided with an extra length portion 2a, and no special measures are taken. As a result,
If the swing stroke shown by the arrow U on the forearm 5 side is large, the extra length portion 2a will increase and the structure will protrude significantly to the outside, so sufficient space must be secured to avoid interference with peripheral equipment. Such problems were occurring.

Therefore, it is an object of the present invention to provide a cable handling device for an industrial robot that can simplify cable handling at a joint between two arms and eliminate cables protruding outside the joint.

[Means to solve the problem]

The present invention provides a rotatable cable support drum at the arm joint, gives the wiring cable wound around the support drum an extra length in the downward hanging area of the support drum, and places this extra length inside the robot arm. The above problem is solved by the configuration of the housed cable processing device.

That is, according to the present invention, in a processing device for a wiring cable that is routed inside an arm of an industrial robot, a cylindrical cylindrical member is rotatably provided coaxially with the joint axis at the arm joint through which the cable passes. a cable support drum, and when the cable that is orbited and held by the cable support drum is allowed to hang down in a U-shape with a predetermined allowance below the cable support drum, one end of the U-shaped cable; and a cable fastening device for locking the cable, and the U-shaped cable with an extra length is wound up or unwound according to the rotation of the arm joint and the cylindrical cable support drum. A cable handling device for an industrial robot is provided.

[Effect]

The wiring cable that passes through the joint goes around the cable support drum and hangs down, and has an extra length inside the robot arm.
Since it extends further downward, when the support drum rotates in synchronization with the rotation of the robot arm, the wiring cable gets wrapped around the support drum and rewound, so that the extra length is reduced. Since it only moves up and down within the robot arm, the wiring cable does not have any effect on the external space due to the rotation of the robot arm. Hereinafter, the present invention will be explained in more detail with reference to embodiments shown in the accompanying drawings.

〔Example〕

FIG. 1 is a partial front view seen from the front of the arm joint, showing the configuration of a cable handling device for an industrial robot equipped with a cable support drum according to the present invention, and FIG.
- It is an arrow view along line 2.

Referring to FIGS. 1 and 2, the upper end of the upper arm 0 and the rear end of the forearm 2 of an industrial articulated robot are pivotally connected at a joint 14. The upper arm 10 is indicated by arrow W in Figure 2.
As shown, the robot arm is a robot arm that can swing back and forth with respect to a robot body (not shown), while the forearm 12 is a robot arm that can swing in the upward and downward direction shown by arrow U with respect to the center of the joint 14. be. The swing of the forearm 12 is driven by a drive motor Mu provided at the joint 14 and a speed reducer Ru provided coaxially with the output shaft of the drive motor Mu. That is, the forearm 12 is connected to the output element of the speed reducer Ru.
The rear end is fixed, so the forearm 12 is directly driven to swing around the center of the joint R14 by the deceleration output. A wrist drive motor Mt and a speed reducer Rt are attached to the rear end of the forearm 12, and are configured to drive the robot movement of the wrist 16 via a transmission mechanism (not shown) provided inside the forearm 12.

Here, according to the present invention, the wiring cable 20 extended and wired from the bottom of the robot body into the inside of the robot upper arm 10 is fixed to the inner wall of the upper arm by a stopper 22 at one end near the top of the upper arm 10. Then, after being given an appropriate length of extra length 20a that hangs down below the upper arm 10, it rises again, exits from the opening 10a at the upper end of the upper arm 10, and is attached coaxially to the reducer Ru. The cable is wound around the cable support drum 24 and then routed toward the inside of the forearm 12 through a cable window 26 formed at the rear end of the forearm 12 . The cable support drum 24 is connected to the upper end of the upper arm 1° and the forearm 12.
It is sandwiched between the rear end of the In this way, since the cable support drum 24 is attached coaxially to the output element of the reducer Ru in a structure that rotates as a unit, when the forearm 12 moves up and down around the U axis,
The cable support drum 24 is also integrally rotated around the U axis. Therefore, when the wiring cable 20 wound around the outer periphery of the cable support drum 24 swings up and down in the clockwise direction in FIG. On the other hand, when the forearm 12 swings downward in the counterclockwise direction in FIG. Displaced in the direction of being pulled up.

As described above, according to the present invention, the wiring cable 20 is wound around the joint 914 around the cable support drum 24 and unwound, and the cable surplus length portion 20a is located below the joint 14. Since the cable 2o is stored inside the upper arm 10 located in the upper arm 10, the conventional problem of the cable 2o forming an outward protrusion from around the joint 14 is solved, and a space for handling the cable can be secured around the joint 140. There is no need. Note that the cable 20 is covered around the cable support drum 24 with a cable cover 28.

[Full-throttle effect]

As is clear from the above description, according to the present invention, in the joint portion between two arms of an industrial robot, cable processing is performed by arranging the cable support drum so that the cable slack length is lowered into the robot arm below the support drum. In the state
Moreover, the cables are wired so that they can be pulled up and down, and the cables only need to be bent in one direction.
No twisting occurs in the cable. Further, since there is no protrusion to the outer periphery of the joint, processing of wiring cables at the joint is simplified, and interference with external equipment can be completely eliminated. Therefore, the rotational range of the arm joint can be very wide, and the cable itself can be protected. Moreover, since the cable allowance length is not provided in a protruding state into the external space around the joint, the external space can be used effectively.

[Brief explanation of the drawing]

FIG. 1 is a partial front view seen from the front of the arm joint, showing the configuration of a cable handling device for an industrial robot equipped with a cable support drum according to the present invention, and FIG.
FIG. 3 is a partial view showing an example of a conventional cable handling device in a joint of an industrial robot. 10... upper arm, 12... forearm, 14... joint,
20...Wiring cable, 20a-...Extra length portion,
22... Clasp, 24... Cable support drum, Mu
... Drive motor, Ru... Reducer. Figure 2

Claims (1)

[Scope of Claims] 1. In a processing device for a wiring cable wired inside an arm of an industrial robot, the arm joint through which the cable passes has a cylindrical shape rotatably provided coaxially with the joint axis. a cable support drum, and when the cable that is orbited and held by the cable support drum is allowed to hang down in a U-shape with a predetermined allowance below the cable support drum, one end of the U-shaped cable; and a cable fastening device for locking the cable, and the U-shaped cable with an extra length is wound up or unwound according to the rotation of the arm joint and the cylindrical cable support drum. cable handling equipment for industrial robots. 2. The cable processing device for an industrial robot according to claim 1, wherein the cable support drum is attached to the outer periphery of a rotary drive mechanism that is provided at the joint and includes a drive motor and a speed reducer.