JPS5924979A - Industrial robot - 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] The present invention relates to an industrial robot.

FIG. 1 shows a typical conventional multi-joint type industrial robot, which has five operating axes and is sold primarily for arc welding of small items. As shown in Fig. 1, the degrees of freedom (action axes) of this robot consist of a ψ axis that rotates the main body α, a θ axis that rotates the first arm b, and an α axis that rotates the 27th arm C. In addition to 3 axes.

It is composed of a total of 5 axes: the V axis for swinging the wrist d up and down, and the V axis for rotating the wrist df.

When performing welding work with this robot, for example, when welding along the welding line f of the workpiece, in order to perform the weaving operation, in addition to the two axes of the wrist (w and ψ axes), the weaving operation for the basic three axes (ψ, θ, α
During the weaving operation, the entire device vibrates according to the weaving amplitude.

Originally, the three basic axes were only used to move the welding torch in space, and the harmonics (approximately 5H2
It is extremely difficult to perform forward and backward movements due to the large inertial load.

In other words, the welding bot that can be configured with such weaving motion axes is not suitable for welding work that requires weaving motion.

The present invention has been made in consideration of the above, and is capable of reducing the oscillating inertia load during weaving welding.
In addition, the control function of each actuator for driving the revolving body and the arm can be simplified, and the power transmission system leading to the wrist shaft can be configured with a chain 7 or a belt-wound transmission device to transmit the power. It is an object of the present invention to provide an industrial robot whose system structure can be simplified and lightened, and the capacity of the actuator for driving the arm can be reduced.

Embodiments of the present invention will be described below with reference to FIG. 2 and subsequent figures.

In the figure, 1 is a main body, 2 is a rotating body that is rotatable about a first axis located perpendicular to the main body 1, and 3 is a rotating body that is horizontally located with respect to this rotating body 2. The first arm % 4 is movable about the 1st axis, and the second arm % 4 is rotatable about the 2nd axis, which is located horizontally, with respect to the tip of the first arm 3. The arm 5 is a first wrist provided at the tip of the second arm 4 so as to be rotatable about the V-axis. A second wrist 6 is provided to
The wrist 6 is provided with a third wrist 7 that rotates carefully around the V-axis.

The structure for driving each of the above rotating members is shown in FIGS. 3 and 4.

That is, the revolving body 2 is engaged with the main body 1 so as to be able to freely rotate about a first axis, and the output shaft of a swing actuator 8 provided on the main body 1 is connected to this revolving body 2. The base of a first arm 3 is connected to the revolving body 2 so as to be freely rotatable around the 2nd axis. The shafts are connected. Further, a base portion of a second arm 40 is pivotally supported at the tip of the first arm 3 so as to be rotatable about the axis No. sprocket 12. on the output shaft of the actuator 11.
13 and Cheno 14i. Since the second arm actuator 11 is fixed to the rotating body 2 as described above, even if the first arm 3 rotates, the second arm 4 remains in the same posture with respect to the rotating body 2, that is, with respect to the reference plane. hold.

A rotary shaft 15 is supported at the tip of the first arm 3 so as to be concentric with the No. 1 axis.
The sprocket +6, which is fixed concentrically with the 1st shaft, is connected to the 1st shaft through the sprocket 16. On the other hand, the rotating shaft 15 is inserted into the second arm 4, and a sprocket 19 is fixed to the tip thereof. On the other hand, the first
A sprocket 20 is fixed to the wrist 5, and both sprockets 19 and 20 are connected by a tie 21.

Therefore, no matter how the first arm 3 and the second arm 4 move, the cow N5 will not move with respect to the rotating body 2, that is,
Maintain the same attitude relative to the reference plane.

The second wrist 6 is rotatably supported on the first wrist 5 about the V-axis, and has a bevel gear mounted on a rotary cylinder 22 that is concentric with the V-axis, which is the rotation axis of the first wrist 5. It is connected through. This second wrist 60 rotation cylinder 22 is a sprocket) 23,
24. It is connected to the second wrist rotation actuator 26 provided at the other end of the second arm 4 via a chain 725.

The third wrist 7, which is rotatably supported on the second wrist 6 about the V-axis, is attached to a rotation shaft 27 for the third wrist that is concentric with the V-axis, which is the rotation wheel center of the first wrist 50. , are connected via a rotating shaft 28 supported on the second wrist 6 and a bevel gear. This third wrist rotation shaft 27 has sprockets 29.30. It is connected to the third wrist rotation actuator 32 provided at the other end of the second arm 4 via a chain 731.

Both rotary actuators 26, 32 are located on the opposite side of the wrist with respect to the pivot point of the second arm 4.

Note that each of the actuators described above uses a DC motor or a hydraulic motor, and each is equipped with a tacho generator, a position detector (encoder), and a speed reducer.

In the above configuration, by driving the swing actuator 8 and the eleventh second arm actuators 9 and 10, the swing body 2 is turned with respect to the main body 1, and the second arms 3 and 4 are also rotated. The first wrist 5 is spatially moved three-dimensionally. At this time, the {circle around (2)} axis, which is the rotational axis of the first wrist 5, is in a floating state, and the {circle over (4)} axis and the v-th axis maintain a constant angle with respect to the reference plane. Therefore, the first wrist 5 is the first wrist,
A constant posture is always maintained regardless of the movement of the second arms 3 and 4.

-1 By driving the second wrist rotation actuator 26, the second wrist 6 is rotated about the v-th axis, and the third
By driving the wrist rotation actuator 32, the third
Wrist 7 can rotate completely.

When performing weaving welding using the welding torch 33 fixed to the third wrist 7, the swing actuator 8. The rotating body 2 and the first and second arms 3 and 4 are rotated and swung by the first and second arm actuators 9 and 11 to move the first wrist 5 along the welding line P. At the same time, the third wrist rotation actuator 32 is driven to swing the third wrist 7 with the required amplitude. At this time, the weaving motion of the third wrist 7 is performed only by the third wrist rotation actuator 32,
The swing actuator 8 and the first and second arm actuators 9 and 10 are driven solely to move the first wrist 5 along the welding line P.

The industrial robot according to the present invention is as described in detail above, and includes a rotating body 2 that rotates with respect to the main body 1, a first arm 3 that rotates with respect to the rotating body 2, and a 17th arm that rotates with respect to the rotating body 2. 3, and a first wrist 5 of a wrist device is rotatably provided at the tip of the second arm 4. 5
The 0 rotation axis is connected to the rotating body 2, and the wrist device is provided with at least one other rotation wrist, and the rotation axis of the other rotation wrist is connected to the actuator for the rotation wrist, and The rotation axis of the first wrist 5 and the rotating body are connected to each other through a winding transmission device provided in the second arm 4, and the other rotating wrist and its actuator are connected via a winding transmission device provided in the second arm 4. Since the actuator is provided at the other end of the second arm 4 and on the opposite side of its rotational fulcrum, the first. When the second arm 3.4 is rotated, the posture of the wrist device can always be one step higher than the reference plane. Therefore, when weaving welding, the rotating body 2 and the first. The second arm 3.4 only needs to move the wrist device in space, and for fine swinging, only the rotating wrist at the end of the wrist device needs to be driven to swing, reducing the swinging inertia load during weaving welding. be able to. In addition, the rotating body 2 and the first and second
Since the actuator for driving the arm 3.4 can be controlled independently of the swing control of one wrist, its control function can be simplified.

Further, according to the present invention, the power transmission system leading to the rotating shaft of the wrist device is configured with a chain transmission or a belt transmission, thereby simplifying the structure and reducing the weight of the power transmission system. be able to. Furthermore, by providing the actuator that rotates the other rotating wrist of the wrist device at the other end of the second arm 4 and on the opposite side of the rotation fulcrum, the moment due to the weight of the second arm 4 can be completely reduced. The capacity of the actuator for rotating the second arm 4 can be reduced.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the configuration of a conventional industrial robot. FIG. 2 is an explanatory diagram of the configuration of the industrial robot according to the present invention, and FIGS. 3 and 4 are explanatory diagrams of the configuration of the power transmission mechanism. 1 is the main body, 2 is the rotating body, 3 is the first arm, 4 is the second arm, and 5 is the first wrist. Departing person: Komatsu Manufacturing Co., Ltd. T5? Masaaki Yonehara, Patent Attorney, Acting Attorney, Book, Tadashi No. 1

Claims (1)

[Claims] A rotating body 2 that rotates relative to the main body 1, a first arm 3 that rotates relative to the rotating body 2, and a second arm 4 that rotates relative to the first arm 3; In an industrial robot in which the first wrist 5 of the wrist device is rotatably provided at the tip of the 27th arm 4, the rotation axis of the first wrist 5 of the wrist device is connected to the revolving body 2, and the wrist device at least 1
A rotation shaft of the other rotation wrist is connected to an actuator for the rotation wrist, and the rotation shaft of the first wrist 50 is connected to the rotating body and the rotation shaft of the other rotation wrist is connected to an actuator for the rotation wrist. The neck and its actuator are connected via a wrap transmission device provided in the second arm 4, and the actuator for the rotating wrist is connected at the other end of the second arm 4 and at its rotation fulcrum. An industrial robot characterized by being installed on the opposite side of the