JPS6358074B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wrist mechanism for an industrial robot.

Conventionally, in industrial robots for automatic welding, for example, as shown in FIG. A device with two degrees of freedom that allows rotational movement is generally used.

However, when actually performing automatic welding,
With two degrees of freedom, it may not be possible to obtain the necessary welding posture.

In this case, it can be solved by adding a motor for one axis to create 3 degrees of freedom, but this also increases the cost, increases the load weight which increases the weight of the robot body, and reduces the size of the tip of the wrist. Problems such as increase will arise.

By the way, depending on the type of machining, a movement with two degrees of freedom is sufficient for most machining operations, and a movement with three degrees of freedom is only required temporarily, for example, when changing the position of a processing tool discontinuously. In this case, the costly 3
Using the wrist movement ability with degrees of freedom in industrial robots is not economically appropriate because the ratio of cost to required ability becomes high.

The present invention has been made in view of the above points, and includes a rotating mechanism that does not have a rotational drive source between the wrist of an industrial robot and a processing tool, and a rotation mechanism that does not have a rotational drive source, and a rotation mechanism that does not have a rotational drive source, and a rotation mechanism that does not have a rotational drive source, and a rotation mechanism that does not have a rotational drive source. By applying a discontinuous turning function that uses rotary motion as a drive source to turn the processing tool by an appropriate amount, it is possible to achieve three degrees of freedom even in the wrist mechanism of an industrial robot that only has two degrees of freedom. Its purpose is to provide something that will enable it to perform operations equivalent to a degree.

FIG. 2 is a partially cutaway side view showing the structure of an embodiment of the present invention.

Reference numeral 4 denotes a cylindrical fixed housing fixed to the actuating arm 1, and the wrist 3 passes through the cylindrical interior of the fixed housing 4. 4a is a drive auxiliary surface formed by tilting the tip of the fixed housing 4; 5 is a cylindrical bearing support portion fixed to the tip of the wrist 3 with its longitudinal direction perpendicular to the axis of the wrist 3; , 6 is a bearing that rotatably supports the pivot shaft 10 and allows the pivot shaft 10 to freely slide up and down in the longitudinal direction, and 7 is engaged with the engaging portion 12 of the pivot shaft for fixing the rotation of the pivot shaft 10. An engaging part is fixed to the upper part of the mating bearing support part 5, 8 is a friction body fixed in the circumferential direction of the drive transmission surface, such as a housing, and 9 is a pivot shaft in contact with a rubber ring 8 fixed to the pivot shaft 10. A drive flange that drives 10, 10 is an arrow C
11 is a collar fixed to the pivot shaft 10; 12 is an engaging portion fixed to the collar 11 and engaged with the engaging portion 7 of the bearing support portion 5; 13 is a collar fixed to the pivot shaft 10; A connecting rod 14 that slides in the axial direction is a return spring that presses the collar 11 downward and engages the engaging parts 12 and 7 when the attraction (lifting up of the upper part) of the rod 13 of the electromagnetic attraction device 16 is released. 15 is a support piece for supporting the electromagnetic attraction device 16 on the bearing support part 5; 16 is a solenoid, for example, which attracts the rod 13 when the excitation current is turned on and pulls up the engaging part 1;
2 and 7 are disengaged and engaged by turning off the excitation current; 17 is a torch holder for holding the torch 2 on the rotating shaft 10; and 18 is a core wire used for welding.

Therefore, the drive flange 9, the pivot shaft 10, the torch holder 17 and the collar 11 are integrally formed.

Bending of arrow A on actuation arm 1 and arrow B on wrist 3
In addition to the two degrees of freedom of rotation, the arrow C of the pivot axis 10
I will explain the third degree of freedom motion (torch indexing motion).

This torch indexing operation is taught in advance to the control section (not shown) of the industrial robot, and the electromagnetic attraction device 16 is excited by the instruction therein.

At this time, the engaging part 12 is disengaged from the engaging part 7, and at the same time, the driving flange 9 rises by a distance l from the dashed line to the solid line, and the inclined surface corresponding to the driving auxiliary surface 4a of the fixed housing 4 is raised. It is pressed against the rubber ring 8.

When the wrist 3 is rotated in the direction of arrow B in this state, the drive flange 9 is rotated in the direction of arrow C perpendicular to arrow B due to friction with the rubber ring 8 that is in pressure contact with it. The rotation angle is taught to the control unit as the movement of the wrist 3 in the direction of arrow B, but this can be set in advance.

When the rotation of the arrow C through the rotation of the arrow B of the wrist 3 rotates by a desired angle, the electromagnetic suction device 1 is activated according to the instruction of the teaching data.
The excitation current to the solenoid 6 is turned off, and the engagement part 7 of the bearing support part 5 and the engagement part 12 provided on the collar 11 of the pivot shaft 10 engage with each other due to the elasticity of the return spring 14. The rotation angle in the direction of arrow C of 10 is fixed.

As a result, the angle of the torch 2 with respect to the workpiece (not shown) changes, and in effect the wrist 3
It can perform functions equivalent to degrees of freedom.

A rubber ring 8 is attached to the drive auxiliary surface 4a of the rotation drive unit 4.
However, a rubber ring 8 may be attached to the inclined surface of the drive flange 9 which has an inclined surface corresponding to the drive auxiliary surface 4a, and a friction plate may be fixed instead of the rubber ring 8. It's okay.

Furthermore, the drive auxiliary surface 4a and the drive flange 9 may be constructed of bevel gears or face gears.

FIG. 3 is a partially cutaway side view showing the structure of another embodiment of the present invention.

In FIG. 3, the same reference numerals as in FIG. 2 represent the same or corresponding parts.

This other embodiment includes a drive flange 9 and a collar 11.
The drive flange 9 has an engaging portion on one surface. A drive flange 9 is arranged on the upper part of the pivot shaft 10 to serve as a backing plate for the return spring 14 of the collar 11.

The operation of this other embodiment is the same as that of the previously described embodiment (FIG. 2).

Accordingly, in the present invention, each of the engagement parts 7 and 12 of the bearing support part 5 and the pivot shaft 10 may be composed of a large number of radially formed splines.

Furthermore, in the present invention, each of the engaging parts 7 and 12 of the bearing support part 5 and the pivot shaft 10 can be formed of a friction plate.

Thus, according to the present invention, between the wrist and the processing tool,
By configuring a rotating mechanism that uses the rotational movement of the wrist as a driving source and does not have its own rotational driving source, which increases cost, increases load weight, and increases the size of the wrist end, it can be used as needed. It is possible to add an operation function equivalent to one degree of freedom, and it is possible to improve the performance of a simple and inexpensive industrial robot.

[Brief explanation of the drawing]

Fig. 1 is a side view of a conventional device, Fig. 2 is a side view showing a partially cutaway structure in one embodiment of the present invention, and Fig. 3 is a partially cutaway side view of another embodiment of the present invention. This is a side view. DESCRIPTION OF SYMBOLS 1... Actuation arm, 2... Torch, 3... Wrist, 4... Cylindrical fixed housing, 4a is a drive assisting surface formed by slanting its tip, 5... Bearing support part, 6... Bearing , 7... Bearing support side engaging part, 8... Rubber ring, 9... Drive flange 9
a is its outer circumferential surface, 10...swivel shaft, 11... collar, 12... pivot shaft side engaging portion, 13... rod,
14... Return spring, 15... Support piece, 16... Electromagnetic attraction device, 17... Torch holder, 18...
Core wire, A...bending direction, B...rotation direction, 6...
Turning direction, l... Drive flange movement distance.

Claims (1)

[Scope of Claims] 1. In a wrist mechanism for an industrial robot having bending and rotation functions, the wrist 3 is provided with a bearing support having an engaging portion at one end perpendicular to the axis of the wrist 3. A torch 2 is provided at one end of the bearing support 5 via a bearing 6.
and the other end thereof is connected to the rod 13 of the electromagnetic attraction device 16 supported by the bearing support part 5, and the other end part is connected to the engaging part of the bearing support part 5 on one side. A pivot shaft 10 is slidably and rotatably supported, and has a collar 11 having an engaging portion pressed and engaged by a return spring 14. A cylindrical fixed housing 4 having the same axis is fixed to the actuating arm 1, and the free end of the fixed housing 4 has a surface that mediates and transmits the displacement caused by the drive of the wrist 3 to the pivot shaft 10. In addition to providing a ring-shaped driving auxiliary surface 4a having an inclined shape,
The rotating shaft 10 has an outer circumferential surface inclined corresponding to the driving auxiliary surface 4a of the fixed housing 4, and is in a non-contact state when the respective engaging portions of the rotating shaft 10 and the bearing support portion 5 are engaged. A certain drive flange 9 is attached, and the pivot shaft 10 is moved against the return spring 14.
sliding in the axial direction to connect the bearing support portion 5 and the pivot shaft 1.
0, the outer circumferential surface of the drive flange 9 of the pivot shaft 10 is pressed into contact with the drive auxiliary surface 4a of the fixed housing 4, and the wrist 3 is rotated to release the pivot shaft 10. 1. A wrist mechanism for an industrial robot, which is characterized by rotating a robot by an appropriate amount. 2. The wrist mechanism for an industrial robot according to claim 1, wherein the electromagnetic attraction device 16 is constituted by a solenoid. 3. The wrist mechanism for an industrial robot according to claim 1 or 2, wherein a rubber ring or a friction plate is fixed to the drive auxiliary surface 4a of the fixed housing 4 or the outer peripheral surface 9a of the drive flange 9. 4. The wrist mechanism for an industrial robot according to claim 1 or 2, wherein the drive auxiliary surface 4a and the outer circumferential surface 9a of the drive flange 9 are comprised of bevel gears or face gears. 5. The drive flange 9 and the collar 11 are integrally formed, and one surface of the drive flange 9 is provided with an engaging portion. Industrial robot wrist mechanism. 6. The industry according to any one of claims 1 to 5, wherein each engagement portion of the bearing support portion 5 and the pivot shaft 10 is constituted by a large number of radially formed splines. Wrist mechanism for robots. 7. The wrist mechanism for an industrial robot according to any one of claims 1 to 6, wherein each of the engaging portions of the bearing support portion 5 and the pivot shaft 10 is constituted by a friction plate.