JPS62193790A - Flexible robot arm - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a wrist portion, that is, a flexible robot arm of an industrial robot such as an electric welding robot or an electric painting robot.

(Prior Art) A conventional example of the flexible robot arm is explained with reference to FIG. 4. A rotary shaft (2) is provided protruding from the robot side arm (1), and a universal joint is attached to the rotary shaft (2). A link (5α) is pivoted on the joint (3) with a pivot (4) (4), and a link (5α) is provided protrudingly. universal join attached to the link (5h)
Attach the middle part of link (5C) to (3b),
The middle part of the link (5d) is pivotally attached to the universal joint (3C) that is pivoted on the rotating shaft (2) and the link (3C).
5b), between links (5α) and (5C), and between links (
Joints (6) are connected between 5b) and 5d so that they can be bent relative to each other with parallel axes.

It has a flexible link arm structure connected by (6h) and (6C), and a tool holder (7) is attached to the tip of the link (5d).
At the same time, a link (5 arm for bending operation (8α) (8h) is installed near the universal joint (3).
) with a drive ring (9).
By rotating the rotating shaft (2), each universal joint,
The tool holder (7) is rotated through each link, and the link (5a) is centered around the pivot (4) by the arm (9), which is driven by moving the arms (8α) and (8b) in the opposite direction of the arrow. As the links (5) are bent, each link is sequentially bent in the same direction via each universal joint and each joint, and the tool holder (7) is tilted.
The structure is such that the held tool can be tilted in any direction by the rotation and tilting operations of the tool holder. In the figure (
a) to (d) are Sunon of each link.

(Problems to be Solved by the Invention) The conventional flexible robot arm has a bending inclination angle of about 11 degrees of the links (5) with respect to the rotation axis (2), and a bending inclination angle of about 346 degrees between each link. Approximately 18
In order to tilt the tool over the hemisphere range of 00, five links are required in addition to the five links, and the bending operation mechanism of the link is located outside the link and is a reciprocating mechanism. There are problems such as the arm and drive mechanism being complicated and large.

(Means for Solving Problems) The present invention is intended to address the above-mentioned problems, and provides a flexible link consisting of a plurality of rigid links sequentially connected to a robot side arm with parallel axes. As an arm,
a bending drive device in which a ball screw shaft with a link universal joint installed along the link arm is connected to the robot side arm and each of the links by a bending interlocking mechanism; and a shaft with the link universal joint installed along the link arm. By incorporating into the link arm a rotary drive device that is connected to a rotary tool holder at the tip of the link arm by a rotation interlocking mechanism, it is possible to significantly simplify the bending drive device and the rotary drive device. In addition to being more compact, the bending performance of the arm, ie, the tilt pointing performance of the tool, is significantly improved to solve the above-mentioned problems.

(Function) When the ball screw shaft with a link universal joint installed along the link arm is rotated, each rigid link is largely bent in the same direction around the parallel axis through each bending interlocking mechanism, and the link arm When the shaft with a universal joint installed in the rotary tool holder is rotated, the rotary tool holder is rotated through the rotation interlocking mechanism, and the tools held in the rotary tool holder are tilted over a wide range. When the rotation of the ball screw shaft and shaft is stopped, the link arm and rotary tool holder are fixed.
The link arm has a simple structure that is sequentially connected to the robot side arm with parallel axes, and the simple structure of the bending drive device and shaft are attached to the link arm, making it compact as a whole. Arm drive operations are performed smoothly.

(Example) An example of the present invention is shown in FIGS. 1 to 3,
Reference numeral (11) shown in FIG. 1 is a robot-side arm that is connected to the robot body and whose drive is controlled, and a parallel shaft (12) is provided at the tip of the robot-side arm (11).

(12A), (12C) with multiple rigid links (1 ren),
(15/') and (15C) are connected in series to form a flexible link arm (15αl'6tC), which is installed along the inside of the link arms (15a, b, C) and inside the robot side arm (11). drive shaft (20α) and link arm (15
α, h, c) A universal joint (2
1α), (21h), and (21C) are provided, and the ball screw shaft (20) is provided.
20) Upper nut (22α) and robot side arm (11)
) are connected by the bending arm (23α), and the bending point A bending interlocking mechanism (2) in which connection points Z of the arms (23a) for
2α, 23α), and the ball screw shaft (a)
and rigid links (15α) and (15A) with the same bending interlocking mechanisms (22b, 23b), (22t', 23
c), and the link universal joints (21α) and (2
1b) and the ball screw shaft (20) with (2C) and the bending interlocking mechanism (22α).

23su, (22b, 23b), (22C, 23C)
A bending drive consisting of a bending drive is integrated into the link arm.

Further, the drive shaft (15α, b,
30α) and a link universal joint (shirt with (31?)) (30) arranged between the tip of the link arm, and
A rotation interlocking mechanism (35) consisting of gears (35) and (36) connects a rotating tool holder (37) which is rotatably attached to the tip of the link arm 0) and the tip of the link arm with a bearing (37α).
, 36), and the rotary drive is incorporated in the link arm.

the ball screw shaft (20) and the shirt)
(30) is a robot side arm (11) as shown in the figure;
The link arms (15α, b, c) are inserted into the holes provided in the rigid links (15α), (15b), and (15C).
It is located within.

In addition, a bellows (40) is arranged in series at the center of each link (15S, (15H), (15C)) and is also connected to the rotary tool holder (37), so that wiring, piping, etc. The storage space is (α□), (b□), (C□) in the figure.
) is the span of each link.

The embodiment of the present invention has the above-mentioned configuration, and its operation will be explained as follows: The ball is rotated through each link universal joint (21s(2)j) (21C) by the rotational drive of the drive shaft (20α). The screw shaft (20) is rotated, and each nut (22, (22b), (22C) is stopped from rotating)
is screwed by the ball screw shaft (20), so the second
Each bending arm (
23tz), (23h), and (23C) are similarly swung in the same direction to form a link arm (15α) together with the ball screw shaft (20).

b, c) are bent greatly as shown by diagonal lines, and the tip of the rigid link (15?), that is, the rotary tool holder (3)
7) is tilted up to ±90°. That is, three rigid links are used, each rigid link is bent ±30° relative to each other, and the rotary tool holder (37) is tilted within 180° as a whole. In addition, the shaft (3 is a link universal joint (31α)
, (31b), and (31C), it does not interfere with the bending operation.

In addition, each link universal joint (31α), (31A), (31C), shaft 7 is rotated by the drive shaft (30 rotations)
(30) and gears (35) and (36), the rotary tool holder (37) is freely rotated.

Furthermore, the entire link arms (15α, b, c) and the rotary tool holder (37) are rotated by the rotation of the robot side arm (11).

When the rotation of the ball screw shaft (20), shirt (30) is stopped, said incorporation into the link arm maintains the bent position of the link arm and prevents rotation of the rotary tool holder.

By bending the link arm, rotating the rotary tool holder, and rotating the entire robot arm, the tool held by the rotary tool holder can smoothly move in any direction over the entire 180° hemispherical direction. Tilt oriented.

(Effects of the Invention) The present invention has the above-mentioned configuration, and when the ball screw shaft with a link universal joint installed along the link arm is rotated, each rigid ring expands greatly around the parallel axis. When the shaft with the link universal joint that is bent and installed along the link arm is rotated, the rotary tool holder is rotated freely, and the bending performance is improved, and the tool's tilt pointing performance is significantly enhanced, and the link arm ,
The structure of the bending drive device and the rotary drive device is greatly simplified, and by incorporating both devices into the link arm, the size is significantly reduced, and the movement of the arm is smoothly performed. Furthermore, by installing both of the above-mentioned devices inside the link arm, it is possible to incorporate wiring and the like into the center of the link arm.

Although the present invention has been described above with reference to embodiments, it goes without saying that the present invention is not limited to such embodiments, and that various design modifications can be made without departing from the spirit of the present invention. .

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG. 1 showing the bent state of the ball screw shaft and link arm, and FIG. FIG. 4 is a perspective view of a conventional example. 11: Robot side arm, 12α, b, C: Parallel axis, 1
5αl'! 'l': rigid link, 20: ball screw shaft, 21αebt'T 31"l'!'#': link universal joint, 22α, b, c, 23α+bt'a bending interlocking mechanism, 30: shirt), 35.36 : Rotation interlocking mechanism (gear), 37: Rotating tool holder

Claims (1)

[Claims] A flexible link arm consisting of a plurality of rigid links sequentially connected to the robot side arm by parallel axes, and a ball screw shaft with a link universal joint installed along the link arm are connected to the robot side arm and each of the above. A bending drive device connected to the link by a bending interlocking mechanism, and a rotational drive device connecting a shaft with a link universal joint installed in the link arm to a rotary tool holder at the tip of the link arm by a rotation interlocking mechanism. A flexible robot arm characterized by: