JPS60118486A - Wrist device for industrial robot - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wrist device for an industrial robot, and particularly to a wrist device suitable for use in a welding robot or the like.

As is well known, most industrial robots are equipped with cables that supply power, 9 atm, materials, etc. to the processing tools attached to the tip of the robot's arm, and within the robot's operating range, these cables are attached. Many efforts have been made to prevent the cable from interfering with the robot's arm or wrist. In arc welding robots, the materials supplied include wire-like welding wire, and in order to ensure a stable supply of the wire, it is undesirable for the cable to bend at a small bending radius.

Figure wJ1 is a front view showing an example of a conventional arc welding robot. In this figure, 1 is a swivel base, 2 is a first arm, 3 is a second arm, and 4 is a wrist device. θ2, the second arm 3 has a degree of freedom of vertical swing θ3, the wrist device M4 has a degree of freedom of bending θ4, and a degree of freedom of twisting θ5. θ4 is about 110 degrees, and the degree of freedom for twisting θ5 is ≠o
It has a movement range of about 0 degrees. Also, 5 is a wrist strap f
It is covered by a bracket attached to the ilt 4, and a welding torch 6 is fixed to the tip of this bracket 5. In addition, this cable is composed of a power cable that supplies power to the 7Fi welding torch 6, a gas hose that supplies shielding gas, and a conduit cable that supplies welding wire.This cable 7 is attached to the ball 8. By parantha 9? T31: J is raised.

Further, 10 is a wire feeding device having a welding wire spool 11, to which the base end of the conduit cable within the cable 7 is connected.

By the way, in the above-mentioned welding robot, when the bracket 5 is rotated within the twisting degree of freedom θ5 and the welding torch 6 reaches the position indicated by the dotted line 6' in FIG. 7, the cable 7 is moved by the arm 3. is suppressed and the second
As shown in the figure, the kana is bent with a small bending radius.

In this case, the conduit cable within the cable 7 is also bent in the same way, and the stability of feeding the welding wire is extremely deteriorated. As a result, a problem arises in that the arc during welding becomes unstable, or in more extreme cases, arc breakage occurs.

This invention is based on the above-mentioned circumstances, and even when the processing tool (the welding torch 6 in the robot mentioned above) moves, the cable for supplying material to the processing tool can be broken by the robot's arm, wrist, etc. The present invention provides a wrist device for an industrial robot that does not bend, and includes an arm rotatably attached to an arm support part,
A wrist frame attached to the tip of the arm, a rotating shaft rotatably attached to the wrist frame and whose axis is orthogonal to the axis of the arm, and a rotating shaft attached to one end of the rotating shaft. The attachment 19 is provided with a holding member for holding the machining elbow.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 is a front view showing the configuration of an arc welding robot equipped with a wrist device according to an embodiment of the present invention, and parts corresponding to those in FIG. 1 are given the same reference numerals.

In this figure, reference numeral 12 denotes a core arm which is rotatably attached to the upper end of the seventh arm 2, and has a degree of freedom θ3 of vertical swing like the first arm 2 described above. In addition, 13 is a rotary arm that is rotatably attached to the first arm 2 in a common manner, and has a degree of freedom of 04' for screwing and twisting.
have. A wrist frame 14 is attached to the tip of this rotating arm 13.
A rotation shaft 15 is rotatably attached to the. In this case, the axis of the rotating shaft 15 is the axis of the rotating arm 13 @O
The wrist frame 1 is placed at right angles to the wrist frame 1.
It is attached so that it protrudes to the outside of 4. This rotation shaft 15 has a bending degree of freedom of 05'. Further, a bracket 16 for supporting the welding torch 6 is detachably attached to one end of the rotating shaft 15 by a port 17, as shown in FIGS.

In this case, the bracket 16 is attached at a position spaced apart from the axis SO of the rotary arm 13 by a distance a shown in FIG. Note that the rotating arm 13 and the rotating shaft 15
For rotary drive & paulownia to rotate, well-known technology (for example, DC motor for rotary drive, gear reduction mechanism, etc.)
The explanation is omitted here because it is configured using .

The operation of one embodiment of the present invention constructed as described above will be explained with reference to FIG. First, the positioning of the bath torch 6 is performed using the rotational degree of freedom θ1 of the swivel base 1 as in the conventional case.
The degree of freedom θ2 of forward and backward swing of the first arm 2 and the second arm 1
This is performed using the degree of freedom θ3 of vertical swinging. Next, the direction of the welding torch 6 relative to the workpiece is determined by the rotary arm 1.
3 rotates, the wrist frame 14 rotates, and the twisting degree of freedom given to the welding torch 6 by the breakage is 04.
' and a bending degree of freedom 05' given to the welding torch 6 by the rotation of the rotation shaft 15. In this case, ``as the position and direction of the welding torch 6 changes,
Although the cable 7 is slightly bent, its movement is restrained by the rotating arm 13 and the wrist V-arm 14, and there is no possibility of bending the cable with a small bending radius. For example, when the tip of the welding torch 6 is directed obliquely upward from the state shown in FIG. 3 as shown in FIG. 5, the cable 7 is only slightly curved on the side of the rotating arm 13.

As explained above, this invention relies on an arm rotatably attached to an arm support, a wrist frame attached to the tip of the arm, and a wrist frame that is rotatable. A rotating shaft that can be attached freely and whose axis is perpendicular to the axis of the arm, and a holding member that is attached to one end of the rotating shaft and holds a processing tool, are provided. When the tool moves, the cable that supplies material to the processing tool will not be bent with a small bending radius by the robot's arm or wrist, and therefore the supply of material will be unstable. This has the advantage of eliminating the possibility of this happening.

[Brief explanation of the drawing]

FIG. 7 is a front view showing an example of the configuration of a conventional arc welding robot, the folded view is a side view showing the configuration of a wrist device of the same welding robot, and FIG. 3 is a wrist device according to an embodiment of the present invention. Figures 1 (a) and (b) are side and front views showing the configuration of the wrist device, and Figure 5 is the same as shown in Figure 3. FIG. 3 is a front view showing the welding torch of the arc welding robot in a state where the welding torch is directed diagonally upward. 13... Rotating arm, 14... Wrist frame, 15... Rotating shaft, 16... Bracket. Applicant: Shinko Electric Co., Ltd. -7 Rikan- Ward 1 Aji

Claims (1)

[Claims] An arm rotatably attached to the arm support part, a wrist frame attached to the tip of this arm,
A rotating shaft is rotatably attached to the wrist frame and whose axis is orthogonal to the axis of the arm, and a holding member is attached to one end of the rotating shaft and holds a processing tool. A wrist device for an industrial robot.