JPH05220689A - Cable guide device for industrial robot - Google Patents

Abstract

PURPOSE:To regulate and guide a cable laid between two relatively operating movable members of an industrial robot without causing looseness, excessive tension, or torsion. CONSTITUTION:When a cable 24 laid between two relatively operating movable member 20 of an industrial robot is guided, a rolling member 18 for regulating and guiding the cable 24 to give a longitudinal following movement to the cable 24 according to the operation when one movable member is relatively operated to the other movable member 20, and outer wheel members 12, 14 for guiding cable turning are provided. Thus, a cable guide device for guiding the cable so that a large cable looseness is never caused, and torsion or tension never act on the cable is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cable guide device for an industrial robot, and more particularly, it guides a cable stretched outside two robot movable members that move relative to each other so as to follow the movement of the movable members. , A cable guide device for an industrial robot capable of eliminating excess cable slack.

[0002]

2. Description of the Related Art An industrial robot is configured to attach various end effectors to a wrist provided at the tip of a robot arm to perform a desired robot work, and to the end effector via a cable. Supply of working gas, liquid, electric power, electric signal, etc. In such a case, the cable, which is placed around the outer circumference of the robot arm, is temporarily fixed at the tip of the robot arm, and an appropriate amount of cable slack is given from the fixed point to the wrist side, and then the end effector. Is configured to connect to. That is, as shown in FIG. 4, a cable 8 stretched between the robot arm 6 and the end effector 7 attached to the wrist 5.
Is fixed at a proper position in the tip end region of the robot arm 6 by a cable fixture 9, and the end effector 7 is given a slack 8a as shown in FIG. The parts were connected to each other.
That is, as shown in FIGS. 4B to 4D, when the end effector 7 moves relative to the arm 6, the cable 8 is prevented from being unduly pulled by the margin of the cable slack 8a. I was doing

[0003]

However, in the state shown in FIGS. 4B and 4C, the portion of the cable slack 8a comes into contact with the side surface of the robot arm 6 and rubs according to the movement of the wrist 5, or The slack 8a may come into contact with the robot joint 5a and cause similar rubbing, which may cause cable damage. In addition, the configuration that gives the slack 8a may cause the cable slack 8a to come into contact with peripheral devices provided around the robot body during the robot operation, which may damage the cable itself or the peripheral devices. There is a problem, and if it is attempted to avoid it, there is a problem that the operating range of the robot body is reduced, and a space margin is required to place peripheral devices sufficiently away from the robot body.

Therefore, an object of the present invention is to provide a cable stretched between two movable members of an industrial robot which are moved relative to each other, without exerting extra slack, and to exert a pulling or twisting action on the cable. It is intended to provide a cable guide device for an industrial robot that adjusts and guides so that there is no problem.

[0005]

SUMMARY OF THE INVENTION Therefore, according to the present invention, when guiding a cable stretched between two movable members of an industrial robot that move relatively to each other, one movable member moves to the other movable member. When performing relative motion with respect to a member, a cable guide that follows the motion so that the cable can be given a follow-up movement in the length direction thereof, and a large cable slack does not occur. It is what constitutes a means.

According to the present invention, there is provided a cable guide device for an industrial robot, which guides a flexible cable stretched between two movable members of an industrial robot which are moved relative to each other, in accordance with the operation of the movable member. Provided as an inner ring member loosely fitted to the movable member, an outer ring member rotatable relative to the inner ring member, and a member fixed to the outer ring member, and movably guiding a cable in its length direction. And a cable guide tool having a cable engaging member for restraining movement in a direction orthogonal to the length direction is provided, and a cable guide device for an industrial robot is provided, preferably, The cable engaging member is provided with a cable guiding device for an industrial robot, which is composed of a pair of rotatable roller members for holding a cable. Less than,
The present invention will be described in more detail based on the embodiments shown in the accompanying drawings.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a front view showing a detailed structure of a cable guide device for an industrial robot according to the present invention, FIG. 2 is a sectional view of the same, and FIG. 3 is a view for explaining the operation of the cable guide device mounted on the robot. FIG. 4 is an operation explanatory view of the conventional cable guide device provided in the industrial robot.

Referring to FIGS. 1 and 2, there is shown one embodiment of a cable guide device for an industrial robot according to the present invention. The cable guide device 10 of the present embodiment is a movable member of an industrial robot, for example, an inner ring member 12 inserted into a robot arm 20, and an outer ring provided on the outer periphery of the inner ring member 12 so as to be capable of relative rotation in the circumferential direction. The member 14 and the outer ring member 14 are attached to appropriate positions by screwing, welding or the like, and fixed cable holding frames 16 and 16 and the cable holding frame 16 are rotatably held, and the inner ring 12 and the outer ring are attached. A pair of rollers 18 and 18 that are separated in the radial direction are provided, and a cable holding space is formed between the pair of rollers 18 and 18. In the illustrated example, the inner ring member 12 and the outer ring member 14 are formed in a sliding engagement, and a rolling member such as a rolling ball or roller is interposed between the inner ring member 12 and the outer ring member 14 like an outer ring in a normal rotary bearing. You may insert and form both so that relative rotation is possible. In addition, the cable guide device 10
Each structural member may be made of a metal material or a plastic material having high strength.

As is apparent from FIGS. 3A to 3D, a plurality of the cable guide devices 10 shown in FIGS. 1 and 2 are prepared, and the inner ring 12 thereof is, for example, a robot of an industrial robot. The cable 24 inserted into an appropriate number of places on the arm 20 and arranged along the surface of the robot arm 29 passes between the rollers 18, 18 attached to each outer ring 14 via the cable holding frame 16. In this manner, the wrist 21 is extended from the base end side to the tip end side of the robot arm 20 and is pivotally attached and coupled to the tip end of the robot arm 20 via a joint 22.
The tip of the cable 24 is connected and piped to a predetermined position of the end effector 26 attached to the.

On the other hand, a sufficient length of the cable 24 is secured on the proximal end side of the robot arm 20, and the cable 24 is appropriately hung from the body structure of the robot body or an appropriate place outside the body, for example, the ceiling portion of the robot use site. The cable 24, which has been known as a cable protection member and is movably held in the vertical direction by such a structural frame, passes through the cable bear 28, and the cable 24 is a gas (eg, pressure air) that is a carrier medium of the cable. In the case of an electric cable or a supply source of a liquid, a liquid material (sealant) or the like, a pipe is connected so as to connect to a power supply device or a control device.

As described above, the cable 24 is stretched and piped between the two robot movable members, such as the robot arm 20 and the end effector 26, which perform relative movements via the joint 22 and the wrist 21. At this time, when the cable guide device 10 according to the present invention is provided, it is not necessary to previously provide the cable 24 with a slack as a margin length in a region where the robot arm 20 and the end effector 26 are pivotally connected. Next, as shown in FIGS. 3A to 3D,
The operation of the cable guide device 10 having the above configuration will be described.

FIG. 3A shows a state in which the end effector 26 is in a supine posture with respect to the robot arm 20,
The cable 24 around the robot arm 20 guided and held by the plurality of cable guide devices 10 passes above the joint 22 and is connected to the inside of the end effector 26 near the proximal end of the end effector 26. Further, the terminal side of the cable 24 has a U-shaped one side fixed to an appropriate position 30 outside the robot body, and the other side passes through a vertically movable U-shaped cable bear 28. Now, as shown by an arrow, when the wrist 21 swings from the state shown in (A) to the axis of the robot arm 20 and moves to the lowered position shown in (B), the cable connection point 26a in the end effector 26 is moved. Since it is rotating, the cable 24 rotates the outer ring 14 of the cable guide device 10 and moves between the pair of rollers 18. That is, the cable 24 also moves naturally under the guidance of the cable guiding device 10 in accordance with the operation of the end effector 26. At this time, on the terminal side of the cable 24, the cable carrier 24 moves slightly upward to feed the variation in the length of the cable 24 to replenish it.

Similarly, FIG.
Rotates in the direction indicated by the arrow relative to the robot arm 20, and at this time, a cable pulling force acts on the cable 24 from the wrist side to the robot arm side as the cable connecting point 26a turns, and therefore the cable Reference numeral 24 induces rotation of the outer ring 14 of the cable guide device 10, and smoothly passes and moves between the rollers 18. At this time, on the terminal side of the cable 24, the cable track 28 moves upward to move the cable 24.
The cable length that is moved by the pulling force that acts on the cable is sent to replenish it.

In the illustrated example, the third cable guide device from the tip side of the robot arm 20 is the other inner ring 12,
Outer ring 14, cable holding frames 16, 16, rollers 18, 1
8 is different from the guiding device 10 having the cable holding frames 16 and 16 and the pair of rollers 18 and 1 on the outer circumference of the robot arm 20.
8 is attached to the guide device which allows only the straight movement of the cable 24. That is, at a position far from the joint 22, the cable 24 does not have to follow the movement of the wrist 21 due to the rotation of the outer ring 14 with respect to the inner ring 12, so the cable holding frames 16, 16 and the rollers 18, 1,
It is a guide device consisting of only eight. However, it goes without saying that, of course, the cable guide device 10 according to the present invention may be attached.

In the operation process of the cable 24 that follows the operation of the robot movable member according to the above description, the cable 24
The case where the cable track 28 moves vertically upward on the distal end side of the guide device 10 has been described. Conversely, when the cable 24 is pushed back toward the distal end side by the relative movement of the end effector 26 with respect to the robot arm 20, With the rotation of, the cable moves through the space between the rollers 18 and 18 toward the cable bear 28 side. At this time, the cable carrier 28
The portion of the cable 24 held by is moved downward by its own weight so that cable slack does not occur in the tip region of the robot arm 20. As mentioned above, in short, according to the present invention,
When the cable 24 is stretched between the two relatively movable members 20 and 26 of the industrial robot, the cable guide device 10 causes one movable member 26 to move relative to the other movable member 20. And the rotation of the outer ring 14 and the roller 1 so that the cable 24 operates in a compliant manner following the operation.
8 is properly guided by rolling, and the cable 24 is automatically adjusted so that excessive pulling does not act and excessive slack does not occur.

In the above description of the embodiment, the industrial robot is stretched across the arm member and the end effector member.
The case of the embodiment in which the cable guide device 10 guides the cables to be wired has been described, but in the case where the robot has two arms pivotally connected via joints, one arm and the other arm are used. It goes without saying that the cable guide device 10 of the present invention can be applied to a cable stretched between the arm and the arm.

[0017]

According to the present invention, a cable is wired and piped between two movable members of an industrial robot that perform relative movement with respect to each other. Since it is guided so as to turn and move straight ahead, the problem that the cable rubs against the surface of the robot body when the robot operates and damage occurs and extra slack occurs and it interferes with peripheral equipment arranged around the robot body Thus, a high-performance cable guide device that does not have a problem of causing the above-mentioned problem can be obtained, and as a result, it is possible to eliminate the trouble of cable maintenance when the industrial robot is used.

Moreover, since the cable guide device according to the present invention can be formed from only four members, that is, the inner ring, the outer ring, the cable holding frame, and the cable guide roller, the effects of low cost and simple structure can be obtained. is there.

[Brief description of drawings]

FIG. 1 is a front view showing a detailed structure of a cable guide device for an industrial robot according to the present invention.

FIG. 2 is a cross-sectional view of the cable guide device.

FIG. 3A to FIG. 3D are operation explanatory views for explaining the operation of the cable guide device mounted on the robot.

FIG. 4 is an operation explanatory view of a conventional cable guide device provided in an industrial robot.

[Explanation of symbols]

 10 ... Cable guide device, 12 ... Inner ring, 14 ... Outer ring, 16 ... Cable holding frame, 18 ... Roller, 20 ... Robot arm, 22 ... Joint, 24 ... Cable, 26 ... End effector, 28 ... Cable bear.

Claims (2)

[Claims] 1. A cable guide device for an industrial robot, which guides a flexible cable stretched between two movable members of an industrial robot which are relatively movable, following the operation of the movable member, wherein the movable member is a movable member. An inner ring member loosely fitted to the inner ring member, an outer ring member rotatable relative to the inner ring member, and a member fixed to the outer ring member, which guides a cable movably in its length direction, and A cable guide device for an industrial robot, comprising: a cable guide having a cable engaging member for restraining movement in a direction orthogonal to the length direction. 2. The cable guide device for an industrial robot according to claim 1, wherein the cable engaging member of the cable guide comprises a pair of rotatable roller members that hold a cable.