JP4761054B2 - Articulated robot - Google Patents

Description

  The present invention relates to an articulated robot for transporting a workpiece.

A conventional articulated robot is known which is a vertical articulated type and is provided with a link-type wrist mechanism fixed on the extension line of the arm 1 at the wrist (see, for example, Patent Document 1). As shown in FIGS. 7 and 8, the base 21, the base 22, the first arm 23, the second arm 24, and the third arm 25 are provided, and a B-axis drive motor 261 provided on the second arm 24 is used to A wrist portion 26 that can turn around a rotation axis (B axis) perpendicular to the longitudinal direction is provided, and the wrist portion 26 is rotated by a T-axis drive motor 271 provided on the second arm 24. A rotating unit 7 that can rotate around a moving axis (T-axis) is provided, and a workpiece gripping device 28 that grips the workpiece W is attached to the rotating unit 27. The first wrist link 263 extending on the extension line of the second arm 24 is rigidly fixed to the outer diameter of the rotating portion 27, and the output shaft 273 (output shaft of the speed reducer) of the rotating portion 27 provided on the wrist portion 6 is The second wrist link 264 is fixed to increase the rigidity of the connecting portion. The tip of the first wrist link 263 is provided with a third wrist link 265 that is pin-coupled so as to be rotatable. The tips of the second wrist link 264 and the third wrist link 265 are parallel to the first wrist link 263. A parallelogram link mechanism is formed by pin-connecting both ends of the fourth wrist link 266. The second wrist link 264 is rotated by the output shaft 273 of the rotating unit 27. At the tip of the third wrist link 265, a work gripping portion 281 that grips the work W is fixed to a flange that is rotated by the rotation of the third wrist link 265.
The workpiece W gripped by the workpiece gripping device 28 is moved in a state where the posture of the workpiece W is always maintained in a certain direction with respect to the moving direction.
Patent No. 2867703 (page 3-4, FIGS. 1 and 2)

A plurality of articulated robots are located, and work is often performed in a narrow space, and there are an increasing number of cases where obstacles exist in the route to be handled. For this reason, articulated robots are desired to have joints added to the workpiece gripping mechanism so that the path can be changed even when an obstacle is present. In the prior art work gripping mechanism, the work can be directed in a predetermined direction, but there is a problem that the obstacle cannot be avoided because it does not have a joint for changing the path to the obstacle.
Also, in order to create a work space that eliminates obstacles, the placement of robots and work positions are changed. However, it is necessary to expand the work space, which increases the factory cost associated with the increase in work space. The problem of becoming.
The present invention has been made in view of such problems, and provides an articulated robot that can change a route so as to grip a workpiece even when an obstacle is on the movement route of the robot, and can work in a narrow space. The purpose is to do.

In order to solve the above problems, the present invention is configured as follows.
Invention of claim 1, and a wrist portion for rotation about a first pivot axis perpendicular to the longitudinal direction of Aamu, attached to the hand neck, with respect to the first pivot axis A rotating part that rotates about a vertical second rotation axis; a second wrist link attached to the rotating part; a fourth wrist link to which the other end of the second wrist link is attached; A third wrist link to which the other end of the four wrist links is attached, a first wrist link to which the other end of the third wrist link is attached, and the other end of the first link are attached to the wrist portion in parallel. In an articulated robot comprising a link mechanism that forms a quadrilateral and a workpiece gripping device attached to the third wrist link, the workpiece gripping device is moved by the rotating portion provided in the wrist portion. the second hand around a second pivot axis Is pivoted by the link and the fourth wrist link third wrist link is rotated, the first wrist link, arranged in the wrist portion in a radial direction of the second rotation axis of the wrist portion a shall be turning by a provided driving mechanism to the bracket.
According to a second aspect of the present invention, the drive mechanism includes a motor disposed on the bracket and a transmission mechanism that converts a rotation angle of the motor between the motor and the wrist. .
According to a third aspect of the present invention, the second pivot shaft is coaxial with the pivot axis of the first wrist link .
According to a fourth aspect of the present invention, the motor shaft and the second rotation shaft arranged on the bracket are arranged on a turning axis.
According to a fifth aspect of the present invention, there is provided a wrist portion that rotates around a first rotation axis that is perpendicular to the longitudinal direction of the arm, and a second portion that is perpendicular to the first rotation axis. A rotating part that rotates around a rotation axis; a second wrist link attached to the rotating part; a fourth wrist link to which the other end of the second wrist link is attached; and other than the fourth wrist link A third wrist link to which an end is attached, a first wrist link to which the other end of the third wrist link is attached, and the other end of the first link are attached to the wrist to form a parallelogram. In an articulated robot including a link mechanism and a work gripping device attached to the third wrist link, the work gripping device is connected to the second wrist link and the first by a rotation mechanism provided in the first wrist link. 4 wrist links and the third Neck link is pivoted by rotating the first wrist link is shall be turning by the second driving mechanism disposed on the wrist unit around the rotation axis of the wrist portion.
According to a sixth aspect of the present invention, the drive mechanism is included in the wrist .
According to a seventh aspect of the present invention, the rotation axis of the drive mechanism and the second link is arranged in parallel to the turning axis .

According to the present invention, by rotating the workpiece gripping device about the rotation axis (T-axis), it is possible to hold the workpiece while avoiding obstacles on the operation path for gripping the workpiece. At the same time, the third wrist link is configured to rotate by transmitting the rotation of the rotating portion by the link mechanism, so that the work can be directed in a predetermined direction. In addition, since obstacles on the movement path can be avoided, it is possible to work with a robot placed in a confined space without changing the placement or work position of the robot even if there is an obstacle. is there.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a side view of the wrist mechanism of the present invention, and FIG. 2 is a plan view thereof. About parts other than a wrist mechanism, since it is the same as that of a prior art example, description is abbreviate | omitted. 1 is an arm, 2 is a wrist part, 3 is a rotating part, 4 is a bracket, 5 is a motor, 6 is a small gear, 7 is a large gear, 8 is a bearing, 9 is a first wrist link, 10 is a second wrist link, 11 is a third wrist link, 12 is a fourth wrist link, 13 is a work gripping device, 14 is a B axis 14, 15 is a T axis, and 16 is a pivot axis. The present invention is different from Patent Document 1 in that a motor for turning the first wrist link is disposed on a bracket attached to the tip fixing portion, and the rotation angle of the motor is changed to the turning angle of the first wrist link via a gear. It is a point that has been converted.
Next, the detailed structure of the present embodiment will be described. A wrist portion 2 that rotates around a rotation axis (B axis) 15 perpendicular to the longitudinal direction of the arm 1 is rotatably attached to the tip of the arm 1. The wrist portion 2 is provided with a rotating portion 3 that rotates around a rotation axis (T-axis) 15 perpendicular to the B-axis 14 so that the axis center coincides with the T-axis 15. One end of the wrist link 10 is attached to the T-axis 15 so that the axis center coincides. One end of a fourth wrist link 12 is rotatably attached to the other end of the second wrist link 10. The other end of the fourth wrist link 12 is attached to one end of a third wrist link 11 that is rotatably supported. One end of a first wrist link 9 that is rotatably supported is attached to the other end of the third wrist link 11, and a work gripping device 13 is provided to the other end of the third wrist link 11. The other end of the first wrist link 9 is rotatably supported by a bearing 8 attached to the wrist portion 2 so that the axis center coincides with the T-axis 15. A bracket 4 is fixed to the wrist 2 in the radial direction from the T-axis 15, and the motor 5 attached to the bracket 4 is arranged so that the motor 5 axis and the T-axis 15 are on the turning axis 16. The small gear 6 that meshes with the large gear 7 attached to the first wrist link 9 is fixed to the tip of the motor 5. Further, the rotation unit 18 includes a motor 5 disposed on the rotation unit 3, the second wrist link 10, the first wrist link 9, and the bracket 4 so that the T-axis 15 installed on the wrist unit 2 is the center. Composed.

Next, the operation will be described. When the rotating part 3 is rotated by a motor (not shown) included in the wrist part 2, the second wrist link 10 is rotated, and the second wrist link 10, the first wrist link 9, the third wrist link 11, and the fourth wrist link 12 are rotated. Thus, a parallelogram is formed, and the workpiece gripping device 13 is rotated.
Further, when the motor 5 rotates, the small gear 6 attached to the motor 5 rotates, and the rotation angle according to the rotation angle and gear ratio of the small gear 6 is transmitted to the large gear 7. The first wrist link 9 rotates at a predetermined rotation angle, and the workpiece gripping device 13 is positioned at a predetermined position. As shown in FIG. 3, in this embodiment (FIG. 3 (b)) compared to the conventional articulated robot (FIG. 3 (a)), the arrangement interval distance of the robot can be shortened from L + α to L, It is possible to shorten the transfer time and work with a robot placed in a narrow space. Further, since the conventional articulated robot does not have a workpiece gripping device, it interferes with an obstacle when gripping the workpiece, whereas in this embodiment, the workpiece gripping device has a joint so that the obstacle It is possible to grip a work while avoiding an object.
The motor arranged on the bracket has been described as an example in which the motor shaft and the T-axis are arranged on the turning axis. However, the small gear attached to the tip of the motor and the large gear attached to the first wrist link are described. The bracket may be disposed in the radial direction from the T-axis so as to mesh with the gear, and is not limited as long as it is disposed at a place where interference does not occur in the operation of the articulated robot. Moreover, although the example which attached the small gear to the front-end | tip of a motor, attached the large gear to the 1st wrist link, and comprised meshing was demonstrated, it is natural that a reduction ratio may be 1 or less.

Next, a second embodiment will be described. 4 is a side view of the wrist mechanism of the present invention, and FIG. 5 is a plan view thereof. The present invention is different from the first embodiment in that a wrist is provided with a motor and the workpiece gripping device is turned by the motor.
Next, the detailed structure of the present invention will be described. A wrist 2 that turns around a rotation axis (B axis) 14 perpendicular to the longitudinal direction of the arm 1 is rotatably attached to the tip of the arm 1. A motor (not shown) is arranged on the wrist 2, and a first wrist link 9 that rotates around a rotation axis (T-axis) 15 perpendicular to the B-axis 14 is attached to the wrist 2. A motor 17 is fixed to the first wrist link 9. One end of the second wrist link 10 is attached to the motor 17, and one end of the fourth wrist link 12 is rotatably attached to the other end of the second wrist link 10. One end of the third wrist link 11 is rotatably attached to the other end of the fourth wrist link 12, and one end of the first wrist link 9 is rotatably attached to the other end of the third wrist link 11. Both the support lengths of the first wrist link 9 and the fourth wrist link 12 are the same, and the support lengths of the second wrist link 10 and the third wrist link 11 are the same, so that they have a parallelogram shape. Yes. The third wrist link 11 is provided with a workpiece gripping device 13 and is disposed at a position on the turning axis 16 from the T-axis 15.

Next, the operation will be described. When a motor (not shown) included in the wrist portion 2 rotates, the first wrist link 9 rotates to rotate the workpiece gripping device 13. In addition, the second wrist link 10 is rotated by the rotation of the motor 17, and the second wrist link 10, the first wrist link 9, the third wrist link 11, and the fourth wrist link 12 that are rotatably supported are parallel to each other. The work gripping device 13 rotates on the turning axis 16 parallel to the T axis by the same amount as the motor 17 while forming the quadrilateral. As shown in FIG. 6, in this embodiment (FIG. 6 (b)) compared to the conventional articulated robot (FIG. 6 (a)), the arrangement interval distance of the robot can be reduced from L + α to L, It is possible to shorten the transfer time and work with a robot placed in a narrow space. Thus, Example 2 has the same effect as Example 1.
The rotation driving mechanism of the workpiece gripping device has been described with the motor and gear transmission included in the wrist. However, belt transmission or a combination of a gear and a shaft may be used as long as the workpiece gripping device can be turned.

The side view of the wrist mechanism of 1st Example of this invention. The top view of the wrist mechanism of 1st Example of this invention Comparison example of equipment layout with the prior art when using the first embodiment of the present invention Side view of wrist mechanism of second embodiment of the present invention. The top view of the wrist mechanism of 2nd Example of this invention Comparison example of equipment layout with the prior art when using the second embodiment of the present invention Side view of a conventional articulated robot Plan view of a conventional articulated robot

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Arm 2 Wrist part 3 Rotating part 4 Bracket 5 Motor 6 Small gear 7 Large gear 8 Bearing 9 1st wrist link 10 2nd wrist link 11 3rd wrist link 12 4th wrist link 13 Work gripping device 14 B axis 15 T axis 16 Rotating axis 17 Motor 18 Rotating part 21 Base 22 Base part 23 First arm 24 Second arm 25 Third arm 26 Wrist part 261 B-axis drive motor 263 First wrist link 264 Second wrist link 265 Third wrist link 266 First 4 wrist link 27 Rotating part 271 T-axis drive motor 273 Output shaft 28 Work gripping device 281 Work gripping part

Claims (7)

A wrist portion for rotation about a first pivot axis perpendicular to the longitudinal direction of the arm is attached to the hand neck, of the second pivot axis perpendicular to said first pivot axis A rotating part that rotates around, a second wrist link attached to the rotating part, a fourth wrist link to which the other end of the second wrist link is attached, and the other end of the fourth wrist link are attached A third wrist link, a first wrist link to which the other end of the third wrist link is attached, and a link mechanism in which the other end of the first link is attached to the wrist portion to form a parallelogram, In a multi-joint robot comprising a workpiece gripping device attached to the third wrist link,
The work gripping device is turned by rotating the second wrist link, the fourth wrist link, and the third wrist link around the second turning shaft by a turning portion provided in the wrist portion. It is,
It said first wrist link, articulated robot, characterized that you turning by the wrist portion of the second driving mechanism in the radial direction provided in the arranged bracket to the wrist portion of the rotating shaft. The articulated robot according to claim 1, wherein the drive mechanism includes a motor disposed on the bracket and a transmission mechanism that converts a rotation angle of the motor between the motor and the wrist. The articulated robot according to claim 1 or 2, wherein the second rotation axis is coaxial with a turning axis of the first wrist link. The articulated robot according to claim 1 or 2, wherein the motor shaft and the second rotation shaft arranged on the bracket are arranged on a turning axis. A wrist that rotates about a first rotation axis that is perpendicular to the longitudinal direction of the arm; and a rotation unit that rotates about a second rotation axis that is perpendicular to the first rotation axis. A second wrist link attached to the rotating part; a fourth wrist link to which the other end of the second wrist link is attached; and a third wrist link to which the other end of the fourth wrist link is attached; A first wrist link to which the other end of the third wrist link is attached; a link mechanism in which the other end of the first link is attached to the wrist to form a parallelogram; and an attachment to the third wrist link In an articulated robot consisting of a workpiece gripping device,
The work gripping device is turned by rotating the second wrist link, the fourth wrist link, and the third wrist link by a rotation mechanism provided in the first wrist link ,
Said first wrist link, an articulated robot which is characterized that you turning by the second driving mechanism disposed on the wrist unit around the rotation axis of the wrist portion. The articulated robot according to claim 5, wherein the drive mechanism is included in the wrist. The articulated robot according to claim 5 or 6, wherein a rotation axis of the drive mechanism and the second link is arranged in parallel to a turning axis.

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