KR940003091B1 - Industrial robot cable - Google Patents

Abstract

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Description

Cable handling structure of industrial robot

1 to 4 show the cable handling structure of the industrial robot as an embodiment of the present invention.

1 is a side view showing a part of the industrial robot to which the structure of the present invention is applied.

2 is a front view of the industrial robot of the present embodiment.

3 is a side view of the industrial robot of the present embodiment.

4 is an enlarged cross-sectional view as seen in the IV-IV arrow direction in FIG.

5 and 6 show the cable processing structure of the conventional industrial robot,

Figure 5 is a front view showing a part of the industrial robot broken conventional application.

6 is a side view showing a part of the industrial robot broken.

* Explanation of symbols for main parts of the drawings

4: turning table 5: rocking belt

6: lower arm 6a: support shaft (swing center)

6b: Slit-shaped opening part 7: Upper arm

7a: upper arm base 7b: 1 degree of freedom

8: wrist frame 9: cable

10: with fixed chain 11: protective spring

12: bush 13: L-shaped iron

14: Saddle 15: Guide

15a: shaft 15b: sleeve

16: liner

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for processing a cable for power transmission to a motor, a limit switch, and the like for transmission and reception of a control signal or the like provided on the arm tip side of an industrial robot.

In general, in industrial robots having at least two arms and rocking tables that are relatively rocking, power and control signals are supplied to, or receive signals from, such as a motor or limit switch built into the arm tip side. In order to do this, the cables are routed, but research is needed to route them as far as possible without leaving the arms.

For example, as shown in Figs. 5 and 6, the cables are wired.

In Figs. 5 and 6, 1 is a swing table, 2 is a lower arm, 3 is an upper arm, and the upper arm 3 is received by the support shafts 2a and 2b with respect to the lower arm 2, and the upper side is While the arm 3 and the lower arm 2 are configured to be relatively swingable, the lower arm 2 is swingably placed on the swinging table 1.

In the industrial robot having such a configuration, a cable (9) for sending electric power, a control signal, etc. to the motor (3a) in the upper arm (3) protects the cable (9). 11 is housed in the upper arm 3 and the lower arm 2.

At this time, in order to minimize the amount of movement of the cable 9 according to the operation of the robot, the cable 9 (protective spring 11) is arranged to pass through the swinging center, and both ends thereof are shown in FIG. As described above, the fixing brackets 11a and 11b are horizontally fixed on the swinging table 1 in the upper arm 3.

In addition, in order to allow the cable 9 to pass through the pivot center between the upper arm 3 and the lower arm 2, the support shafts 2a and 2b of the pivot center between the upper arm and the lower arm 2 are As shown in Fig. 5, the two side portions of the upper arm 3 are separately provided, and each of the support shafts 2a and 2b has a support structure for one time.

However, in the cable processing structure of the conventional industrial robot, since the support shafts 2a and 2b are once supported in the joint portion between the upper arm 3 and the lower arm 2, the industrial structure requiring high rigidity is required. When applied to robots, there is a problem of insufficient rigidity.

Moreover, in the upper arm 3, since the upper end side of the cable 9 (protective spring 11) is fixed horizontally, the attachment space is necessary in the upper arm 3, and the motor 3a etc. It is difficult to arrange them concisely because the structure is moved to the front side or the rear side with respect to the swinging center.

An object of the present invention is to provide a cable handling structure of an industrial robot that can reduce the size of a cable without damaging the cable and without causing a rigid shortage in the joint portion. do.

In order to achieve the above object, the cable handling structure (claim 1) of the industrial robot of the present invention is to follow the swing direction of the upper arm to one end of the cable to the exposure position out of the swing center of the upper arm to the lower arm. The cable is arranged up to the rocking table so as to pass through the lower arm to form an S-shape, and the other end of the cable is inclined in a direction spaced from the vertical to the right to fix the rocking plate. It is characterized in that a bush is provided at the portion extending from the lower arm to the upper arm and extending to allow the cable to slide and move.

In addition, the cable handling structure (claim 2) of the industrial robot of the present invention is provided with a guide which abuts the cable within the lower arm and restricts the entry of the cable between the lower arm and the swing table. It is characterized by one.

Further, the cable processing structure (claim 3) of the industrial robot of the present invention is characterized in that a liner is provided at a portion in contact with the cable in the lower arm.

In the cable processing structure (claim 1) of the industrial robot of the present invention described above, since the cable is arranged so as not to pass through the swinging center of the upper arm with respect to the lower arm, the cable handling structure having both ends of the lower arm and the upper arm has a joint structure. can do.

In addition, the cable is fixed to the upper arm so as to follow the swing direction, so that the relative swing between the upper arm and the lower arm can be easily followed, and there is no need to provide a space for attaching the cable in the upper arm. .

Furthermore, when the cable enters and exits the lower arm due to the swinging of the upper arm and the lower arm, the cable enters and exits without wearing the lower arm held by the bush. At this time, since the other end side of the cable is inclined in the direction spaced from the vertical direction to the right side and fixed to the swinging table, the cable is formed in an S-shape, so that the cable can be retracted without interfering with the lower arm and the swinging table.

In addition, when the S-shaped portion of the cable is largely deformed to enter the space between the lower arm and the swinging band in response to the retraction of the cable, the entry of claim 2 is in contact with the cable and the entry is restricted. The cable can be prevented from being pinched between the lower arm and the swing table.

Moreover, even if the lower arm inner wall and the cable slide while contacting due to the deformation of the cable, the cable slides smoothly with respect to the liner by installing the liner of claim 3 in this part, and the wear of the lower arm inner wall is prevented. You can prevent it.

Hereinafter, referring to the drawings, a cable processing structure of an industrial robot according to one embodiment of the present invention will be described. FIG. 1 is a side view showing a part of an industrial robot to which the structure of the present invention is applied, and FIG. 2 is an industrial view of this embodiment. Front view of the robot, FIG. 3 is a side view of the industrial robot of the present embodiment, and FIG. 4 is an enlarged cross-sectional view as seen in the IV-IV arrow direction of FIG.

In Figs. 1 to 3, 4 is a swing table, 5 is a swing table freely supported on the swing table 4, 6 is a lower arm, which 7 is allowed to swing on the swing table 5, 7 is The upper arm 7 is pivotally supported by the support shaft 6a at the distal end of the lower arm 6, and the upper arm 7 is connected to the lower arm 6 by the upper arm base 7a. ) And one arm freedom portion 7b attached to the arm base portion 7a with rotational freedom in uniaxial rotation. 8 is a wrist flame which is fixed to one degree of freedom 7b of the upper arm 7 and has two degrees of freedom of bending and twisting.

In the industrial robot having such a configuration, a cable 9 for sending electric power, a control signal, or the like to a motor (not shown) in the upper arm base portion 7a is provided with a protective spring (a close contact spring) as in the related art. 11 is housed in the upper arm base 7a and the lower arm 6.

At this time, in this embodiment, as shown in Figs. 1 and 2, the upper end side of the protective spring 11 (cable 9) is the swing center of the upper arm base portion 7a with respect to the lower arm 6 ( By the clamping rod 10 so as to follow the swinging direction of the upper arm base portion 7a at an exposure position outside the distance d from the support shaft 6a position, that is, perpendicular to the upper arm base portion 7a. It is fixed. The fastener 10 is formed in the shape of a nut in order to twist and fix the protective spring 11.

The protective spring 11 for accommodating the cable 9 passes through the lower arm 6 from the upper arm foundation 7a side and from the slit-shaped opening 6b below the lower arm 6. It is exposed to the outside, forms an S shape, and is arranged up to the swinging table 5.

The lower end portion of the protective spring 11 (cable 9) guided to the swinging table 5 is inclined at an angle θ by a direction from the vertical direction to the rear (direction spaced from the vertical direction to the right side), and the L-shaped metal fitting (13) And it is fixed to the swinging table (5) by the saddle (14). The L-shaped bracket 13 is attached on the swinging table 5, and the L-shaped bracket 13 and the saddle 14 make the lower end of the protective spring 11 noise, so that the protective spring 11 is closed. It is fixed to the swinging table (5).

In addition, the bush that slides the protective spring 11 in a portion where the protective spring 11 (cable 9) is exposed from the lower arm 6 to the upper arm base portion 7a and extends to the side extends. (12) is provided. For example, the bush 12 is made of a material such as becelite or MC nylon in consideration of wear resistance.

At a predetermined position in the slit-shaped opening 6b of the lower arm 6, as shown in FIGS. 1 and 2, the lower arm 6 and the swing table 5 abut against the protective spring 11. A guide 15 is provided which can restrict the entry of the protective spring 11 between the and the helical spring to preserve the S-shape of the protective spring 11. As shown in FIG. 4, the guide 15 is composed of a shaft 15a fixed to the lower arm 6 and a fitted sleeve 15b loosely fitted on the outer circumference of the shaft 15a. It is. As the sleeve 15b, wear-resistant materials, such as MC nylon, are used, for example.

Furthermore, a plate-shaped liner 16 is provided in the part which contacts the protective spring 11 of the inner side of the lower arm 6, and is excellent in sliding motion and wear resistance. As this liner 16, wear-resistant materials, such as MC nylon, are used.

By the above-described configuration, the protective spring 11 and the cable 9 are arranged so as not to pass through the swing center of the upper arm base portion 7a with respect to the lower arm 6, that is, the position of the support shaft 6a. Therefore, the joint portion between the lower arm 6 and the upper arm foundation 7a is constituted by an integral shaft through which the support shaft 6a penetrates the lower arm 6 and the upper arm foundation 7a. The support shaft 6a is supported by a bearing at both ends of the joint portion of the lower shaft arm with a bearing. With the support structure at both ends, the upper arm 7 is moved upward and downward in the joint portion of the lower arm 6 and the upper arm base 7a (a, b directions in FIG. 1) about the axis of the support shaft 6a. The bending to the support shaft 6a resulting from the step S) is reinforced by the support shaft 6a of the integral structure, thereby obtaining a highly rigid joint portion.

In addition, since the upper end of the protective spring 11 (cable 9) is fixed to the upper shaft arm base portion 7a in the swing direction, the protective spring 11 (cable 9) has an upper side. It is easy to estimate the relative fluctuations between the arm 7 and the lower arm 6, and at the same time, it is not necessary to provide a space for attaching the cable 9 in the upper arm base portion 7a as in the prior art. It can be configured small.

However, at this time, since the attachment position of the upper end of the protective spring 11 (cable 9) is out of swing, the protective spring 11 according to the swing of the upper arm base portion 7a with respect to the lower arm 6 is provided. The amount of shank movement of (cable 9) becomes considerably large compared with the conventional thing.

In other words, the protective spring 11 (cable 9) moves in accordance with the swing of the upper arm base portion 7a as follows. When the upper arm 7 swings in the direction of arrow A shown in FIG. 1, the cable attachment position on the upper arm 7 approaches the lower arm 6, so that the protective spring 11 (cable (9) is extruded downward, while the upper spring (7) is reversely protected when the upper arm (7) swings in the direction indicated by arrow B shown in FIG. (Cable 9) is pulled out, and entry and exit from the lower arm 6 of the protective spring 11 (cable 9) becomes considerably severe.

With respect to the behavior of the protective spring 11 (cable 9), in this embodiment, the protective spring 11 is held by the bush 12 at the entrance from the lower arm 6, It is prevented from damaging the wear of the lower arm 6 (usually made of aluminum casting) generated by the protective spring 11. In addition, the movement amount of the protective spring 11 (cable 9) is absorbed by the part formed in S shape.

As a result, since the lower end side of the protective spring 11 (cable 9) is inclined in the direction spaced apart from the vertical direction to the right side and fixed to the swinging table 5, the upper arm 7 When the protective spring 11 (cable 9) is press-fitted into the lower arm 6 in response to the swing of the c), the protective spring 11 (cable 9), as shown by the dashed line in FIG. Similarly, while retreating backward from the slit-shaped opening 6b, absorbing the protection spring 11 (cable 9) that is press-fitted, and interfering with the lower arm 6 and the swinging table 5, none.

In addition, as described above, with the retraction operation of the protective spring 11 (cable 9), the S-shaped portion of the protective spring 11 (cable 9) is made larger from the slit-shaped opening 6b. In the case of deforming to the front side and attempting to enter between the lower arm 6 and the swinging table 5, the guide 15 abuts against the protective spring 11 so that its entry is restricted. Therefore, even if the arm 6, 7 is rocked in any position, the protection spring 11 (cable 9) can be prevented from being pinched between the lower arm 6 and the rocking table 5.

Further, the protective spring 11 (deformation of the cable 9, the predetermined portion of the inner wall of the lower arm 6 (in this embodiment, the inner circumferential surface of the front side wall portion) and the protective spring 11 are shown in FIG. As shown in the figure, since the slide moves while contacting, in this embodiment, since the liner 16 is provided in this part, the protective spring 11 slides smoothly with respect to the liner 16 so as to move the lower arm. Abrasion of the inner peripheral surface of (6) can be prevented.

As described above, according to the cable processing structure of the industrial robot of the present invention, since the cable does not pass through the swinging centers of the arms, the joints of the arms can be supported by both ends, and the rigidity of the joints can be improved. At the same time, since the cable is attached to the upper arm along the swinging direction, the space for attaching the cable is unnecessary on the upper arm, and the joint portion can be made compact.

Further, since the bush is configured to prevent the lower arm from being worn and to absorb the movement of the cable in the S-shaped portion, the disadvantages of deviating from the swing center of the cable attachment position to the upper arm are completely eliminated.

In addition, the guide restricts the entry between the lower arm and the swing table due to the retraction of the cable, and reliably prevents the cable from being pinched between the lower arm and the swing table. Since the cable slides smoothly with respect to the liner, it also has the effect of reliably preventing wear of the inner wall of the lower arm.

Claims (3)

In the cable handling structure of an industrial robot having a relatively swinging upper arm, a lower arm, and a rocking table on which the lower arm is swingably mounted, one end of the cable swings the upper arm relative to the lower arm. It is fixed to the swinging direction of the upper arm at the exposure position away from the center, and is arranged to the swinging table so that the cable passes through the lower arm to form an S shape, and the other end side of the cable is vertical. A bush for holding the cable to be slidable at a portion where the cable is inclined in the direction spaced from the right to the right side and fixed to the swinging band, and the cable is exposed and extended from the lower arm to the upper arm side. Cable handling structure of an industrial robot, characterized in that. 2. The cable handling structure of an industrial robot as set forth in claim 1, wherein a guide is provided within said lower arm to contact said cable to regulate the entry of said cable between said lower arm and the swinging bar. . The cable handling structure of an industrial robot according to claim 1, wherein a liner is provided at a portion in contact with the cable in the lower arm.