JP2009220219A - Cable retention device for robot arm - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent stress concentration on a robot arm. <P>SOLUTION: Upper ends of a pair of cylindrical members 6 disposed at a predetermined interval apart, the lower ends, and both of left/right end portions of the outer circumferential faces are connected to each other respectively by upper face plate 7, a lower face plate 8 and left/right side plates 9 respectively to form a hollow-structure robot arm 1. A round pipe 6 is attached to cable insertion holes 10 bored respectively at central portions of parts that are located in the inside surrounded with the circumferential walls of the respective cylindrical members, or the upper face plate 7, the lower face plate 8 and the left/right side plates 9, and a cable 3 is passed and laid inside the round pipe 6. The round pipe 6 is disposed at the width-directional-side central position in a neutral plane of the robot arm 1 to eliminate a possibility that the round pipe 6 may affect a bending and a twisting-directional stress applied to the robot arm 1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a robot arm cable holding device for holding an electric cable, an air hose, a hydraulic hose or the like wired in the longitudinal direction of an arm of an arm robot.

  In general, arm robots are often used as industrial robots. In this type of arm robot, an end effector attached to the tip side of the robot arm, an electric cable for power transmission or signal transmission such as a joint part of the robot arm itself, and the like can be wired in the longitudinal direction of the robot arm. May be required. In addition, depending on the drive type of the end effector or the joint of the robot arm, it may be necessary to wire an air (pneumatic) hose or a hydraulic hose in the longitudinal direction of the robot arm.

  Therefore, as one of the methods for wiring the cable such as the electric cable, the air hose, and the hydraulic hose in the longitudinal direction of the robot arm in the conventional arm robot, the cable is connected to the robot arm using the space outside the robot arm. Conventionally, it has been configured to pass through the outside.

  As another conventional method for wiring a cable to a robot arm, a configuration has been adopted in which the cable is arranged around the outer surface of the robot arm.

  Further, as shown in FIGS. 6A and 6B, a cable storage portion 2 along the longitudinal direction of the robot arm 1 is recessed in the upper portion of the robot arm 1, and the robot arm 1 is provided in the cable storage portion 2. It has also been proposed to store the cable 3 for passing through the cable and close the opening upper surface of the cable storage portion 2 with a protective cover 4 (see, for example, Patent Document 1).

JP-A-2-269593

  However, in the system in which a cable is passed through the outer space of the robot arm, a substantial amount of space is required around the robot arm. Furthermore, there is also a concern that the cable may be damaged or disconnected due to excessive force applied to the cable during the rotation of the robot arm or interference with the robot arm.

  Further, in the system in which the cable is arranged over the outer surface of the robot arm, there is a risk of rubbing or interference with the robot arm.

  Furthermore, in the method of storing a cable by providing a cable storage part on the upper part of the robot arm, the cross section of the robot arm is not smooth because the cable storage part is recessed on the upper surface of the robot arm that is a structure. Therefore, there is a problem that stress concentration occurs.

  In particular, in a type of arm robot in which a large load is applied, since a large stress in the bending or twisting direction acts on the robot arm, it is strongly desired to prevent the occurrence of stress concentration.

  Therefore, the present invention provides a robot arm cable that can hold an electric cable, a cable such as an air hose or a hydraulic hose in a robot arm of an arm robot, and can prevent the concentration of stress in the robot arm. A holding device is to be provided.

  In order to solve the above-mentioned problems, the present invention corresponds to claim 1 and extends in the longitudinal direction of the robot arm at the center in the width direction of the neutral surface of the robot arm inside the robot arm. A pipe-shaped cable guide member communicating with each joint portion provided at both ends of the robot arm is provided, and a cable to be laid between the joint portions of the robot arm is laid inside the cable guide member. The configuration is as follows.

  Further, in the above configuration, the cable guide member provided at the center position in the width direction of the neutral surface of the robot arm inside the robot arm is configured to have a grooved steel shape instead of the pipe shape. To do.

  Similarly, in the above configuration, a chamfered portion that smoothly expands the diameter is provided at both ends in the longitudinal direction of the inner peripheral surface of the cable guide member.

  In each of the above-described configurations, a resin bush for inserting the cable is provided at both ends in the longitudinal direction of the cable guide member.

The robot arm cable holding device of the present invention exhibits the following excellent effects.
(1) A pipe-shaped cable extending in the longitudinal direction of the robot arm at the center position in the width direction of the neutral surface of the robot arm inside the robot arm and communicating with each joint provided at both ends of the robot arm. Since a guide member is provided and a cable to be laid between the joint portions of the robot arm is laid inside the cable guide member, a large load acts on the robot arm, Even if a large stress in the bending or twisting direction acts on the robot arm, it is possible to prevent the cable guide member from affecting the rigidity of the robot arm in the bending or twisting direction. Therefore, the cable can be laid in the robot arm with a simple structure, and the outer shape of the cross section of the robot arm, which is a structure, can be made smooth, so there is a risk of stress concentration in the robot arm. Can be prevented. In addition, since the cable is laid inside the cable guide member provided inside the robot arm, it is possible to surely prevent the moving robot arm and the cable from interfering with each other. Furthermore, since it is possible to suppress the friction of the cable, it is possible to extend the life of the cable and to improve the cleanliness.
(2) The cable guide member provided at the center position in the width direction of the neutral surface of the robot arm inside the robot arm may be a groove steel shape instead of the pipe shape. The same effect as (1) can be obtained.
(3) Since the chamfered portion that smoothly expands the diameter is provided at both ends in the longitudinal direction on the inner peripheral surface of the cable guide member, the cable rubbing can be further reduced, so that the cable life The effect of further extending the length and further improving the cleanliness can be expected.
(4) The same effect as in the above (3) can be expected by providing a resin bush for inserting the cable at both longitudinal ends of the cable guide member.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  1 (a), (b) and FIG. 2 show an embodiment of a cable holding device for a robot arm according to the present invention. The robot arm 1 has a hollow structure and a central portion inside the robot arm 1. FIG. For example, a round pipe 5 serving as a cable guide member extending in the longitudinal direction of the robot arm 1 is provided in the center in the width direction of the neutral surface position, and the longitudinal direction of the robot arm 1 is provided inside the round pipe 5. An electric cable to be wired, a cable 3 such as an air hose or a hydraulic hose is inserted and laid. In FIGS. 1A and 1B and FIG. 2, for convenience of illustration, a single cable 3 is simply shown as a representative (the same applies to FIGS. 3A and 3B).

  More specifically, the robot arm 1 has two cylindrical members 6 extending in the vertical direction in the horizontal direction to form joints that can rotate in the horizontal direction at both ends of the robot arm 1. The upper and lower ends of each cylindrical member 6 are arranged at a required interval, and the left and right ends of the outer peripheral surface are respectively connected via an upper surface plate 7, a lower surface plate 8, and a pair of left and right side wall plates 9, respectively. Are connected to each other to form a hollow integrated structure.

Further, a cable insertion hole for allowing the cable 3 to be inserted into a central portion of an inner portion surrounded by the upper surface plate 7, the lower surface plate 8, and the left and right side plates 9 on the peripheral wall of each cylindrical member 6. 10, and the round pipe 6 is arranged between the cable insertion holes 10 provided in each cylindrical member 6, and both ends of the round pipe 6 are connected to the cable in each cylindrical member 6. It is configured to be joined to the peripheral edge of the insertion hole 10. As a result, the cable 3 is installed between the cylindrical members 6 located at both ends of the robot arm 1 through the inside of the round pipe 5. Even if a large load acts on the robot arm 1 when a large load acts on the robot arm 1, the round pipe 5 has a central portion in the width direction at the neutral surface position of the robot arm 1. Therefore, it is possible to prevent the round pipe 5 from influencing the rigidity of the robot arm 1 in the bending and twisting directions.

  Thus, according to the cable holding device for a robot arm of the present invention, the cable 3 can be laid in the robot arm 1 with a simple structure. In addition, since the outer shape of the cross section of the robot arm 1 which is a structure can be made into a smooth rectangular shape, the possibility of stress concentration can be prevented. Moreover, since the cable 3 is laid through the round pipe 5 provided in the robot arm 1, the possibility that the operating robot arm 1 and the cable 3 interfere with each other can be reliably prevented. Further, since the friction between the cable 3 and the robot arm 1 can be kept small, the life of the cable 3 can be extended and the cleanliness can be improved.

  Furthermore, an effect of improving the appearance of the robot arm 1 can be expected.

  Next, FIG. 3 (a) (b) shows a modification of the embodiment of FIGS. 1 (a) (b) and FIG. 2 as another embodiment of the present invention. 1 is the same configuration as shown in FIGS. 1A and 1B and FIG. 2, and between the cable insertion holes 10 provided in the pair of cylindrical members 6 constituting both ends of the robot arm 1, Instead of the configuration in which the round pipe 5 is attached, a rectangular pipe 11 as a cable guide member is attached between the cable insertion holes 10 provided in the pair of cylindrical members 6.

  3 (B) shows a cable insertion provided in a pair of cylindrical members 6 constituting both ends of the robot arm 1 in the same configuration as shown in FIGS. 1 (B) and 2 above. Instead of the round pipe 5, a groove steel 12 as a cable guide member is attached between the holes 10.

  Other configurations in FIGS. 3A and 3B are the same as those shown in FIGS. 1A and 1B, and the same components are denoted by the same reference numerals.

  According to any of the embodiments shown in FIGS. 3 (a) and 3 (b), the same effects as those of the above-described embodiment can be obtained.

  Next, FIG. 4 (a) (b) shows an application example of the embodiment of FIG. 1 (a) (b) and FIG. 2 as still another embodiment of the present invention. (B) and a configuration similar to that shown in FIG. 2, a peripheral portion of the cable insertion hole 10 provided in the pair of cylindrical members 6 constituting both ends of the robot arm 1, and both ends of the round pipe 5 A resin bush 13 for inserting the cable 3 is attached to the joint portion.

  As shown in FIG. 4A, when the diameter of the cable insertion hole 10 is smaller than the inner diameter of the round pipe 5, the resin bush 13 is attached inside the cable insertion hole 10, On the other hand, as shown in FIG. 4 (b), the diameter of the cable insertion hole 10 has a size corresponding to the outer diameter of the round pipe 5, and the end of the round pipe 5 is inserted into the cable insertion hole 10. If attached, the resin bush 13 may be attached to the inside of both ends of the round pipe 5.

  Other parts that are the same as those shown in FIGS. 1A and 1B and FIG.

  According to the present embodiment, the cables 3 laid inside the round pipe 5 are respectively drawn out from the both ends of the round pipe 5 to the inside of the pair of cylindrical members 6 constituting the both ends of the robot arm 1. The cable 3 can be prevented from touching the metal part such as the peripheral part of the cable insertion hole 10 drilled in the cylindrical member 6 or both end parts of the round pipe 5. Since wear in the portion can be suppressed, the life of the cable 3 can be further extended, and the cleanliness can be further improved.

  FIG. 5 shows another application example of the embodiment shown in FIGS. 1 (A) and (B) and FIG. 2 as still another embodiment of the present invention. The round pipe 5 attached between the cable insertion holes 10 provided in the pair of cylindrical members 6 constituting both ends of the robot arm 1 in the same configuration as shown in FIG. The chamfered portions 14 that are smoothly expanded in diameter by machining are provided at both end portions in the axial direction of the inner peripheral surface of the round pipe 5a.

  It is assumed that the round pipe 5a is attached with both end portions thereof inserted into the cable insertion holes 10 provided in the cylindrical members 6 respectively. Other parts that are the same as those shown in FIGS. 1A and 1B and FIG.

  Also in the present embodiment, the cables 3 laid inside the round pipe 5a are respectively drawn out from the both ends of the round pipe 5a to the inside of the pair of cylindrical members 6 constituting both ends of the robot arm 1. Since the wear of the cable 3 can be suppressed, the life of the cable 3 can be further extended and the cleanliness can be further improved.

  In addition, this invention is not limited only to the said embodiment, The resin bush 13 in embodiment of FIG. 5 (B) (B) is replaced with the embodiment in FIG. 3 (B) (B). Joints between both ends of the square pipe 11 and the cable insertion holes 10 of the pair of cylindrical members 6 constituting both ends of the robot arm 1, and both ends of the grooved steel 12 in the embodiment of FIG. You may apply to the junction part with the cable penetration hole 10 of a pair of cylindrical member 6 which comprises the both ends of the robot arm 1. FIG.

  The square pipe 11 in the embodiment of FIGS. 3 (a) and 3 (b) is a thick square pipe, and the axial peripheral end edges of the inner peripheral surface of the thick square pipe are the same as in the embodiment of FIG. You may make it provide the chamfering part which spreads out smoothly similarly to the chamfering part 14 smoothly diameter-expanded provided in the axial center both ends edge part of the thick round pipe 5. As shown in FIG.

  As long as the cable guide member can lay and hold the cable 3 on its inner side, the diameter and width may be appropriately changed according to the thickness and number of the cables 3 to be held. A pipe having a cross-sectional shape other than 5 or the square pipe 11 may be used. Further, the cable guide member is arranged on the neutral surface of the robot arm 1, and even when a large load is applied to the robot arm 1, no force is applied to the cable guide member. As long as the weight of the cable can be supported, the material of the cable guide member may be appropriately selected from metal, resin, and the like.

  Of course, various modifications can be made without departing from the scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS One Embodiment of the cable holding device for robot arms of this invention is shown, (A) is a general | schematic cutting side view, (B) is an AA direction arrow directional view of (A). It is a schematic perspective view which shows the whole structure of the robot arm provided with the cable holding apparatus of FIG. FIG. 2 shows a modification of the apparatus of FIG. 1 as another embodiment of the present invention. (A) shows a case where the cable guide member is a square pipe, and (B) shows that the cable guide member is a grooved steel. It is a figure corresponding to Drawing 1 (b) showing each case. FIG. 4 shows still another embodiment of the present invention, and (a) and (b) are schematic cut side views showing an application example of the apparatus of FIG. 1. It is a general | schematic cutaway side view which shows other form of implementation of this invention. The cable accommodation part for accommodating a cable in the robot arm proposed conventionally is shown, (A) is a schematic cut | disconnection side view, (B) is a BB direction arrow directional view of (A).

Explanation of symbols

1 Robot arm 3 Cable 5 Round pipe (cable guide member)
6 Cylindrical member (joint part)
10 square pipe (cable guide member)
11 Channel steel (cable guide member)
13 Resin bush 14 Chamfer

Claims (4)

  Pipe-shaped cable guide members that extend in the longitudinal direction of the robot arm and communicate with the joints provided at both ends of the robot arm at the central position in the width direction of the neutral surface of the robot arm inside the robot arm. A cable holding device for a robot arm, characterized in that a cable to be wired between the joint portions of the robot arm is laid inside the cable guide member.   The robot arm according to claim 1, wherein the cable guide member provided at the center in the width direction of the neutral surface of the robot arm on the inner side of the robot arm has a grooved steel shape instead of a pipe shape. Cable holding device.   The cable holding device for a robot arm according to claim 1 or 2, wherein chamfered portions that smoothly expand in diameter are provided at both ends in the longitudinal direction of the inner peripheral surface of the cable guide member.   4. The cable holding device for a robot arm according to claim 1, wherein resin bushes through which the cable is inserted are provided at both longitudinal ends of the cable guide member.

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