JPS60114490A - Multi-joint arm - 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] Technical field The present invention relates to an articulated arm.

Prior Art Conventional multi-jointed arms have a drive source and a control system for each joint, so the weight-to-torque ratio decreases in proportion to the number of joints, and it is inevitable that the cost will increase. . There is also a multi-joint arm in which multiple drive sources are placed at the base of the fire and rotational force is transmitted to the shafts of each joint using wires, etc., but this also has the same problem.

OBJECTS OF THE INVENTION Accordingly, an object of the present invention is to provide a multi-joint arm that uses only one drive source, increases the weight-to-torque ratio, and reduces costs.

Structure of the Invention The present invention provides a clutch and a driven rotation for each joint, one driving rotating member for each joint, and a drive device for rotationally driving this driving rotating member. By tensioning a flexible tension member (chain, timing belt, wire, etc.) and controlling the selection of each clutch and the rotation angle and direction of the drive rotating member, the arm tip can be positioned at any position within a plane. It is something to do.

Example Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an external view of a multi-joint arm according to one embodiment of the present invention. The multi-joint arm of this embodiment includes a first arm 1.
2nd arm 2. 8th arm joint 11. Second joint12. 8th joint 18. 4th joint 14. 5th joint 15. 6th joint 1
6, a driving sprocket 7, a fixed arm 8 that pivotally supports the first joint 11 and the driving sprocket 7, a servo motor 9 with a pulse generator that drives the driving sprocket 7, and a speed reducer 10. and both ends are fixed to the tip of the sixth arm 6, and the guide sprockets in each arm 1 to 6 and the fixed arm 8, and each joint 1-
An internal control device 17 stretched across the driven sprockets 1 to 16 and the driving sprocket 7, and the fixed arm 8.
Fix the servo motor 9. Reducer 10. Control device 17
It consists of a support stand 19 on which is installed.

Next, each arm 1-6. The structure of each joint 11-]-6 will be explained in detail. 2 is a plan view of the first arm 1 seen from above in FIG. FIG. 3 is a diagram (two-dot chain line) showing a state in which the camera is rotated upward by an angle θ.

The fixed arm 8 includes support frames 8a and 8b which are parallel and whose lower left ends are welded to the support stand 19, an upper guide sprocket 8c, a lower guide sprocket 8d, and the support frame 8.
Shafts 8e and 8f are rotatably supported at both ends by a + 8b, and guide sprockets (8c and 8d) are fixed to the center, respectively, and a drive sprocket 7 is fixed and rotatably supported by support frames 8a and 8b to reduce speed. It consists of a shaft 8g coupled to the output shaft of the machine IO. The first arm 1 includes parallel support frames 1a and lb, upper guide sprockets lc and ld, and a lower guide sprocket 1.
e + 1 f, both ends are rotatably supported by support frames 1a and 1b, and guide sprockets lc and 1d are provided in the center.
, 1e, lf, respectively) 15'.

It consists of lh, li, and lj. The first joint 11 includes a driven sprocket) lla and a driven sprocket l.
la is fixed, and the support frame 1 a of the first arm 1 is fixed.]
, b, and rotationally supported on the support frame 8a of the fixed arm 8) 1 l b , between the support frame 1b of the first arm 1 and the support frame 8b of the fixed arm 8, the shirt)
It consists of an electromagnetic clutch llb and an electromagnetic clutch llc arranged concentrically. Like the first arm 1, the second arm 2 also has parallel support frames 2a and 2b and upper guide sprockets 2c and 2.
d, lower guide sprockets 2e and 2f, and shaft 2g.

It consists of 2h, 2i, and 2j. Like the first joint 41, the second joint 12 also includes a driven sprocket 12a, a shaft 12b, and an electromagnetic clutch 2c. Other 8th arm 8. 4th arm hand, 5th arm5. 6th arm 6, 8th joint 18. 4th joint 14. 5th joint 15. 6th
Joint 16 also has the same structure. However, since the sixth arm 6 is the tip arm, the number of upper guide sprockets and lower guide sprockets is one each. chain 1
8 has one end fixed to the tip of the sixth arm 6, and sequentially
Sixth arm 6, sixth joint 16. 5th arm 5° 5th joint 15. 4th arm 4. 4th joint 14. 8th arm 3. 3rd joint18. 2nd arm 2. Second joint12. 1st arm 1. It meshes with the upper guide sprocket and driven sprocket of the first joint 11, passes through the upper guide sprocket 8c of the fixed arm 8, reaches the driving sprocket 7, and after meshing with this, the lower part of the fixed arm 8 Guide sprocket) 8d, then sequentially 1 joint 11° 1st
Arm l, second joint 12. 2nd arm 2. 8th joint 18
．． 8th arm 3. 4th joint 14. 4th small arm. 5th joint]-5, 5th arm 5. 6th joint6. Sprocket for lower guide of 6th arm.

The other end is connected to the 6th arm 6 via the driven sprocket.
It is fixed and stretched at the tip of the.

Next, the operation of the multi-joint arm of this embodiment will be explained. In the initial state, each of the arms 1 to 6 and the fixed arm 8 are in a straight line, and from this state, as shown in FIG. radians). In the initial state, the electromagnetic clutches of the joints 11 to 16 are in a connected state, the first arm 1 to the sixth arm 6 have a rigid integral structure, and each of the arms 1 to 6 cannot move. In this state, only the electromagnetic clutch of the first joint 11 is disengaged. Thereby, the first arm l can rotate around the first joint 11. Now each joint 11
Let D be the pitch circle diameter of the driven sprockets 1 to 16, and d be the pitch circle diameter of the driving sprocket 7. When the first arm 1 is rotated by an angle θ, the contact point p of the chain 18 and the driven sprocket )lla of the first joint 11 is also rotated by the same angle θ, and is at the position p' (that is, the chain 18 The length of the lower part becomes longer by Dθ74, and the length of the upper part becomes shorter by Dθ/2. Therefore, the driving sprocket 7 is moved at an angle of θ'-Dθ/d ('
, ' dθ/2−Dθ/2) By rotating in the direction of the arrow in the figure, the first arm 1 to the sixth arm 6 as a whole rotate upward by an angle θ with respect to the fixed arm 8. Then, after this, the electromagnetic clutch of the first joint 1 is brought into the connected state again.

Above, a case has been described in which only the electromagnetic clutch LLC of the first joint 11 is disconnected, the first arm 1 to the sixth arm 6 are rotated together, and the tip position of the sixth arm 6 is changed. By appropriately combining the electromagnetic clutches to be disengaged and controlling the rotation angle and rotation direction of the drive sprocket 7, the position of the tip of the sixth arm 6, which is the tip arm, can be changed in various ways. In addition, each arm 1
~6 length (distance between centers of each joint 11-16), pitch circle diameter D1 of driven sprocket of each joint 11-16
By storing the pitch circle diameter d of the drive sprocket 7 in advance in a storage device and inputting the desired position of the tip arm 6, the rotation angle of each arm 1 to 6, and therefore the rotation angle of the drive sprocket 7, can be automatically adjusted. Calculate the first arm 6
The movement of the multi-jointed arm can be controlled such that the tip of the multi-joint arm is positioned at the desired position. Further, although the multi-joint arm of the present invention is capable of only two-dimensional movement, three-dimensional movement is also possible by rotating the support base 19 about an axis parallel to the plane of motion of the multi-joint arm. Other items (pulleys, timing belts, etc.) may be used in place of sprockets and chains as long as they do not slip or stretch.

Effects of the Invention Since the multi-jointed arm of the present invention has only one driving source regardless of the number of joints, the weight-to-torque ratio is increased and the cost is reduced compared to the conventional arm.

2 is a partial plan view seen from above in FIG. 1, and FIG. 8 is a sectional view taken along the line A and -A2 in FIG. 2.

1: 1st arm, 2: 2nd arm, 3: 8th arm, 4
=4th arm, 5: 5th arm, 6: 6th arm, 11
: 1st joint, 12: 2nd joint.

18: 8th joint, ■4 = 4th joint, 15: 5th joint, 1
6: 6th joint, 1a, 1b, 2a, 2b: Support frame, 7:
Driving sprocket), 11a, 12a: Driven sprocket, 8c, 8d, lc.

ld, le, lf, 2c, 2d, 2e, 2f: G8: Fixed arm, 9: Servo motor, 1o: Reducer, 17:
Control device, 18: Chain, 19: Support stand.

11-

Claims (1)

[Claims] The first arm is connected to the (i-1) arm by the first joint.
In a multi-joint arm that is connected to the th arm, the 0th arm is a fixed arm, and the 1st to nth arms are all movable arms that rotate within the same plane, a support frame, this support frame , a plurality of movable arms and one fixed arm having an upper guide rotation member and a lower guide rotation member supported transversely with respect to the longitudinal direction thereof, and a support frame 1 for the first arm. c is fixed, and the (i
-1) a shaft rotatably supported on a second support frame;
A driven rotating member is fixed concentrically to the center of the shaft, and the driven rotating member is arranged concentrically to the shaft and allows the first arm to rotate relative to the (i-1)th arm in the disconnected state. a joint having a clutch, a driving rotating member, a rotating member for an upper guide, a rotating member for a lower guide, a driven rotating member for each joint, which is fixed to the n-th arm whose both ends are tip arms; A flexible tensile member tensioned without slipping on the driving rotating member, a drive device that rotationally drives the driving rotating member, disconnection and connection of clutches at each joint, and rotation of the driving rotating member by the drive device. A multi-jointed arm comprising a control device that controls the angle and the direction of rotation.