JPH0527267Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a cable support device for a spot welding robot, and specifically relates to support of a flexible cable for supplying current, etc. to a welding gun. .

(Prior Art) In a spot welding robot, which is one type of industrial robot, a welding gun is moved to a welding location on a workpiece by swinging or rotating an arm member or a hand member. A flexible cable for supplying current, air, and cooling water is connected to this welding gun with a predetermined amount of slack so that it can follow the movement of the welding gun. However, due to slack, this flexible cable vibrates during movement of the welding gun and comes into contact with the welding gun itself, an arm member, a hand member, etc., which may cause damage to the cable.

The cable support device disclosed in Japanese Utility Model Application Publication No. 138483/1983 is intended to solve this problem. The support device described in the publication includes a movable horizontal arm (arm member), a wrist arm (hand member) attached to the distal end of the horizontal arm so as to be rotatable around the same axis as the horizontal arm, and In a spot welding robot equipped with a welding gun attached to a wrist arm, one end of a plate spring bent into an approximately L-shape is rotatably attached to the horizontal arm, and the other end of the plate spring is attached to a predetermined position from the welding gun. It is fixed to a flexible cable at a length apart. A rotating member for pivotally attaching the leaf spring to the horizontal arm includes a shaft member having one end fixed to the horizontal arm and extending in a direction substantially perpendicular to the axis of the horizontal arm;
It is composed of a support part fitted to each shaft member, and one end of the leaf spring is fixed to the support part. This is an attempt to maintain a certain distance between the flexible cable and the horizontal arm by using the rotation of the support and the deflection of the leaf spring when the wrist arm rotates with the welding gun. It is.

(Problem to be solved by the invention) The above-mentioned conventional cable support device does not include a means for regulating the posture of each flexible cable between the fixing position of the leaf spring to the flexible cable and the welding gun. Therefore, when the wrist arm rotates significantly around the axis of the horizontal arm together with the welding gun, the flexible cable comes into contact with the horizontal arm. For example, when the wrist arm rotates nearly 180 degrees, the portion of the leaf spring that extends in the axial direction of the horizontal arm bends significantly toward the horizontal arm, causing the flexible cable to contact the horizontal arm and cause the cable to Damage could occur.

In addition, this cable support device requires three components: a shaft member, a support section, and a leaf spring, and not only is the structure complicated, but it also causes wear and noise on the sliding surface between the shaft member and support section. There were also problems such as the occurrence of

SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a cable support device that can reliably prevent a flexible cable from coming into contact with an arm member and has a simple structure that does not have a sliding surface.

(Means for Solving the Problems) As shown in FIG. Arm member 6
A hand member (wrist arm) 4 rotatably attached to the hand member 4, a work tool (welding gun) 2 for performing welding attached to the hand member 4; A flexible cable 12, one end of which is connected to the working implement 2 so as to supply electric current or the like.
A spot welding robot equipped with a first elastic member (coil spring) 32 and a first holding member ( The bracket 34 not only supports one point of the flexible cable 12 on the arm member 6, but also supports the flexible cable 12 at a second point.
The other point of the flexible cable 12 is supported by the hand member 4 by an elastic member (coil spring) 22 and a second holding member (bracket) 24.

More specifically, the first elastic member 32 is an elastically bendable member whose one end is fixed to the arm member 6 and whose axis extends substantially perpendicular to the axis of the arm member 6. Moreover, the first elastic member 32 can be elastically bent in all directions around its own axis. The first holding member 34 is a member for fixing one point of the flexible cable 12 to the other end of the first elastic member 32. The second elastic member 22 is
It is an elastically bendable member whose one end is fixed to the hand member 4 and whose axis extends substantially perpendicular to the rotation axis of the hand member 4 . This second elastic member 22 is also elastically bendable in all directions around its axis. The second holding member 24 is arranged so that the flexible cable 12 is loosened between the origin position of the hand member 4 shown in FIGS. 1 and 2 and the point where the flexible cable 12 is fixed to the first elastic member 32. This is a member for fixing the other point of the flexible cable 12 to the other end of the second elastic member 22 so that the slack portion 13 of the flexible cable does not come into contact with the arm member 6.

As a result, when the hand member 4 with the working tool 2 is rotated to the working position, as shown in FIG.
The first and second elastic members 32 and 22 hold the flexible cable 12 in an arm state while the flexible cable 12 is stretched in a substantially straight line between the first holding member 34 and the second holding member 24. Each axis is bent in an arched manner so as to be held at a position apart from the member 6.

(Function) According to the above configuration of the present invention, when the hand member 4 rotates, for example, counterclockwise when viewed from the working tool 2, the base end of the second elastic member 22 also rotates in the same direction by the same angle. move. During this rotation,
The flexible cable 12, which had been slackened between the first holding member 34 and the second holding member 24, is stretched in a substantially straight line. When the rotation angle of the hand member 4 further increases, the first and second elastic members 32,
22, while the flexible cable 12 is stretched substantially linearly, the axes of the cables 22 are bent into an arcuate shape due to the interaction of the respective restoring forces. That is, the first and second elastic members 32, 22 both face leftward in FIG. In the downward direction, the second holding member 24 attached to the tip of the second elastic member 22 is elastically bent in the upward direction. As a result, even when the hand member 4 is rotated approximately 180 degrees, the flexible cable 12 is held at a position apart from the arm member 6 like the string of a bow.

(Embodiment) Hereinafter, a cable support device according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3.

FIG. 1 is a side view of a spot welding robot to which the present invention is applied. The illustrated spot welding robot 100 includes a welding gun 2 and a wrist arm 4 as a hand member.
It has a horizontal arm 6 and a vertical arm 8 as arm members, and a base (not shown). The vertical arm 8 stands up from the base so that it can rotate around a vertical axis and can swing back and forth around one end on the base side. The other end of the vertical arm 8 supports one end of a horizontal arm 6 that extends in the horizontal direction. The horizontal arm 6 is capable of vertically swinging around this support portion. The other end of the horizontal arm 6 has a proximal end 3 of the wrist arm 4.
are connected to the horizontal arm 6 via the joint part 5 so as to be movable about the axis thereof. A welding gun 2 as a working tool is rotatably provided on the wrist arm 4 at a mounting portion 14 having an axis parallel to the axis of the horizontal arm 6.

As described above, by arm operation of the spot welding robot 100 having the vertical arm 8, the horizontal arm 6, and the wrist arm 4, the welding gun 2 is moved from the origin position shown in FIG. 1 to the welding location of the workpiece. One end of a flexible cable 12 for supplying current, air, and cooling water is connected to the upper end 10 of the welding gun 2. The other end of the flexible cable 12 is connected to a control box (not shown).

Now, the cable support device for supporting the flexible cable 12 is composed of a wrist arm side support device 200 and a horizontal arm side support device 300.

The wrist arm support device 200 includes a coil spring 22 as an elastic member extending substantially perpendicular to the rotation axis of the wrist arm 4, and a bracket 24 as a cable holding member. The coil spring 22 is attached to the wrist arm 4 using an arm-side bracket 26. As shown in FIGS. 2 and 3, which represent the A-A cross section in FIG. It is attached to the periphery of the holder via a pad 28, and the open portion is fixed via a fixing plate 30 by tightening a nut. The fixing plate 30 has a mounting portion 14 for the welding gun 2.
One end of a coil spring 22, which is an elastic member that can be elastically bent and extends outward, is fixed in a direction perpendicular to the rotation axis of the wrist arm 4.
Further, a fixing plate 31 is fixed to the other end of the coil spring 22, and a flexible cable 12 is disposed between the fixing plate 31 and the cable-side bracket 24, and the flexible cable 12 is clamped by bolting. ing.

The horizontal arm side support device 300 also has the same components as the wrist arm side support device 200, and is erected at a position on the horizontal arm 6 near the vertical arm 8.
Moreover, at the origin position shown in FIGS. 1 and 2,
Both support devices 200 and 300 are lined up in the same direction. That is, the horizontal arm side support device 300 includes a coil spring 32 whose one end portion is fixed to the horizontal arm 6 via the arm side bracket 36 and extends in a direction perpendicular to the axis of the horizontal arm 6, and the coil spring 32 and other parts. It has a cable side bracket 34 at the end for fixing the flexible cable 12. However, the coil spring 32 of the horizontal arm side support device 300 has the same length as the coil spring 22 of the wrist arm side support device 200. Furthermore, as shown in FIG. Supported to avoid contact.

Next, the movement of each part when the wrist arm 4 is rotated approximately 180 degrees counterclockwise when viewed from the welding gun 2 side will be explained with reference to FIG.

When the wrist arm 4 begins to rotate around the axis of the horizontal arm 6 together with the welding gun 2 to the working position, the wrist arm side support device 200 provided on the wrist arm 4
Both begin to rotate. Then, the support point of the flexible cable 12 by the coil spring 22 of the wrist arm support device 200 is gradually pulled diagonally downward, and the flexible cable 12 is stretched in a straight line. When the rotation angle of the wrist arm 4 further increases, both coil springs 22 and 32 maintain the flexible cable 12 in a straight line and maintain their respective lengths substantially constant, while their respective restoring forces interact. The respective axes are bent in an arcuate manner. That is, when both coil springs 22 and 32 face toward the left in FIG. The brackets 24 attached to the tips of the coil springs 22 of the arm-side support device 200 are elastically bent in the upward direction. As a result, even when the wrist arm 4 is rotated approximately 180 degrees, the flexible cable 12 is maintained at a position away from the horizontal arm 6.

Note that the welding gun 2 is attached to the attachment part 1 of the wrist arm 4.
4, the flexible cable 12 is pulled downward and the wrist arm side support device
200 coil springs 22 are bent. However, this coil spring 22 extends to the outside of the attachment portion 14, and a restoring force acts to return the wrist arm 4 to its original vertical state, similar to the rotation of the wrist arm 4 described above. Therefore, the part of the flexible cable 12 between the part supported by the bracket 24 of the wrist arm side support device 200 and the part connected to the welding gun 2 is connected to either the welding gun 2, its attachment part 14, or the wrist arm 4. There is no contact with.

As described above, according to this embodiment, the flexible cable 12 does not come into contact with the horizontal arm 6, the attachment part 14 of the welding gun, etc. when the wrist arm 4 or the welding gun 2 rotates. Damage can be reliably prevented.

(Effects of the invention) As explained above, according to the invention, elastic members are made to stand up from both the arm member and the hand member, and a flexible cable is supported at the tip of each elastic member. Therefore, when the hand member is rotated with the work tool, each elastic member is bent in an arch shape while the flexible cable is stretched in a substantially straight line, so that the flexible cable is always in a position away from the arm member. Retained. This has the effect of reliably preventing damage to the flexible cable.

Furthermore, since the cable support position according to the present invention can be constructed with only a coil spring and a bracket, for example, the structure is not only simpler than that of the conventional cable, but also there is no sliding surface, so there is no wear or noise.

[Brief explanation of drawings]

Figure 1 is a side view showing one embodiment of the present invention;
The figure is a cross-sectional view taken along line A-A in Figure 1, showing the state before the wrist arm rotates, and Figure 3 is a cross-sectional view taken along line A-A in Figure 1, showing the state when the wrist arm has rotated approximately 180 degrees. It is. 2...Welding gun (work tool), 4...Wrist arm (hand member), 6...Horizontal arm (arm member),
12... Flexible cable, 22, 32... Coil spring (first and second elastic member), 24, 3
4...Bracket (first and second holding members).

Claims (1)

[Scope of Claim for Utility Model Registration] A movable arm member; a hand member attached to the distal end of the arm member so as to be rotatable around the same axis as the arm member between an origin position and a working position; In the spot welding robot, the spot welding robot includes a work tool for performing welding attached to the hand member, and a flexible cable having one end connected to the work tool so as to supply current or the like to the work tool. A device for supporting a flexible cable, wherein one end is fixed to the arm member, the axis extends in a direction substantially perpendicular to the axis of the arm member, and the cable is elastic in all directions around the axis. a bendable first elastic member; a first holding member for fixing one point of the flexible cable to the other end of the first elastic member; one end fixed to the hand member; a core extending substantially perpendicular to the rotational axis of the hand member;
and a second element that can be elastically bent in all directions around the axis.
The flexible cable has slack between the elastic member and the fixing point of the flexible cable to the first elastic member at the origin position of the hand member, and the slack portion of the flexible cable is connected to the arm. a second holding member for fixing another point of the flexible cable to the other end of the second elastic member so as not to contact the member; When pivoting to the position, the first and second elastic members hold the flexible cable in a state in which the flexible cable is stretched in a substantially straight line between the first holding member and the second holding member. A cable support device for a spot welding robot, characterized in that each axis is bent in an arcuate manner so as to hold the cable at a position apart from the arm member.