JPS62107994A - Wrist mechanism of 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 [Field of Industrial Application] The present invention relates to an improvement of a wrist mechanism having three degrees of freedom as a manipulator for a multipurpose industrial robot with six degrees of freedom.

(Prior Art) The first conventional example of this type is Utility Model Application No. 58-44671 [Patent Publication No. 59-151692]. □ The first conventional example is the wrist swing axis (hereinafter referred to as " The swing angle of the "B axis" is limited by the mutual interference between the gears installed inside and the angle of the split surface, which maintains the degree of freedom while the spherical cover that covers the wrist part splits into two. 11
0° is the limit.

In addition, since a spherical cover is required, the number of parts is large.

Furthermore, as a second precedent, patent application No. 59-27402F4
is proposed.

A side sectional view of the main part of this second prior example is shown in FIG.

An R-axis that rotates the entire wrist supported by the arm 10 of the industrial robot and rotatably centered around the arm axis, and an axis (38 input transmission shaft) supported by the R-axis and perpendicular to the R-axis. The tip of the wrist (17
A T-axis for rotating the wrist tip 17, which is supported by the B-axis and rotatably centered on the - T-axis perpendicular to the B-axis, is provided. , The T-axis and the B-axis are decelerations arranged so as to be superimposed on the same central axis 3a! This is a wrist mechanism for an industrial robot in which the R-axis is decelerated in advance by a (a deceleration mechanism consisting of a harmonic drive at 6 and 7), and the R-axis is decelerated in advance outside the wrist.

That is, the R-axis output shaft 1 is rotatably supported by a bearing 11 supported by an arm 10, and the output after deceleration is transmitted by a deceleration unit installed at the rear of the arm (not shown), and the output shaft 1 is rotatably supported by a bearing 11 supported by an arm 10. Rotate.

A B-axis drive reduction gear 116 rotatably supported by bearings 14a and 14b supported by a housing 9 fixed on the R-axis output shaft 1 has an input side that receives the signal from the B-axis input shaft 2 before deceleration. It is equipped with high-speed bevel gears 4a and 4b for the B-axis that change the direction of power, and the reduced output is taken out from the movable circular spline 6a to rotate the tip of the wrist horizontally about the B-axis. Note that 6b is a fixed circular spline fixed to the housing 9, 6C is a flex spline that meshes with each of the circular splines 6a and 5b, and 6d is a wave generator connected to the bevel gear 4.

The T-axis drive reduction gear 7 is rotatably supported on the upper inner periphery of the BIII drive reduction rock 6 via bearings 15a, 15b, and 15c, and the input side is connected to the T-axis input shaft 3 before deceleration. High-speed bevel gear 5 for T-axis that changes the direction of the power of
a, 5b are provided, and the decelerated output is taken out from the movable circular spline 7a, and further passes through the T-axis low-speed bevel gear that changes the direction of the power, and then to the bearings 16a, 16 at B@.
The processing tool grip part 17, that is, T@, rotatably supported by b is rotated. Note that 7b is a fixed circular spline attached to the movable spline 7a, and 7C is a fixed circular spline attached to the movable spline 7a.
are flex splines that mesh with the respective circular splines 7a and 7b, 7d is a wave generator, and T
It is attached to an input transmission shaft 3a connected to the axial input shaft 3 via a bevel gear.

[Problem that the invention seeks to solve]

Although this second prior example successfully covers the bottlenecks of the first conventional example, the distance between the rotation centers of the T-axis and R-axis, that is, the amount of offset, is large (for example, in one model, it is 180#).
, the external force load torque of the R-axis drive system increases.

Since the input gears 5b and 4b of the B-axis and T-axis have a double structure, there remain drawbacks such as difficulty in assembling and adjusting the gear V.

Here, the present invention overcomes the difficulties of the conventional examples and the preceding examples, reduces the offset between the T axis and the R axis, makes the industrial robot easier to use, advances in maintenance, and improves the reliability of the industrial robot wrist. Its purpose is to provide a mechanism.

(Means for Solving the Problems) In order to achieve the above object, the present invention arranges a main reduction gear at the tip of the wrist, and these main reduction gears are connected to the R axis that forms the center line of the arm. ,
■The @ and 8@ main reducers are distributed to the left and right, and the input shaft is the same as the R axis, which forms the center line of the arm, and the output shaft of the B-axis main reducer is connected to the center of the arm. Connected to the fixed side of the T @ main reducer with a torque arm that crosses the line, and the T export force shaft and its output gear are offset to the side opposite to the center line of the arm when viewed from the T shaft part reducer. This is the wrist mechanism of an industrial robot.

[For production]

In the present invention, the main reducers for the B-axis and the T-axis are arranged on the left and right sides of the center of the arm axis, and since mutual interference between the main reducers is eliminated, the rotation angle of the B-axis is expanded, and the rotation angle of the B-axis is expanded. The offset of the tool grip becomes smaller.

〔Example〕

FIG. 1 shows a cross-sectional side view of the main parts of an embodiment of the present invention.

FIG. 2 is a partially cutaway front view.

The same reference numerals represent the same or corresponding parts in all drawings.

In this embodiment, the arrangement of the main reduction gear and the arrangement of the input side gears are almost the same as those of the first conventional example, in which the wrist has a built-in reduction gear.

However, from the output shaft of the B-axis main reducer (harmonic drive) 6, the torque arm 30 rotatably supported by bearings 31 and 32 supported by the R@ member is output, and the TIM main reducer The means connected to the fixed side of (harmonic drive) 7, the output shaft of the T-axis (processing tool gripping part 17), and the gear 8 are
The main reduction gear of the shaft 8!17 is a means of moving it to the opposite side from the arm center line, which was changed for structural improvement.

In addition, 6e is a set screw, and 13a is a collar.

13b is a nut (external thread), 16G is a spring.

16d is a washer, 16e is a set screw, 17a is a B nut, and 17b is a set screw.

With this configuration, as is clear from FIG. 2, the rotation range of the torque arm 30 due to the B-axis output can be approximately 150 degrees left and right with the upper portion as the center.

FIG. 3 is a cross-sectional view of another embodiment of the invention.

This embodiment has a configuration substantially similar to that of the previous embodiment, but T
The modification is that a T-axis heavy reduction gear IR7 for transmitting power from the shaft input shaft 3 to the processing tool gripping part 17 is provided at the tip of the wrist. That is, the bevel gear 5b that meshes with the bevel gear at the upper end of the T-axis input shaft 3 is connected to a connecting tube 22 by a set screw 21, and this connecting tube 22 is provided on the same axis as B@ and extends toward the tip of the wrist. It is set up. A bevel gear V8 is similarly attached to the other end of the support tube 22 with a set screw 23, and this bevel gear 8
A bevel gear r24 that rotates the processing tool gripping portion 17 is engaged with the bevel gear r24. The shaft portion 24a of the bevel gear 24 is supported so as to be perpendicular to B@, and the T@ main reduction gear 7 is disposed around the shaft portion 24a of the bevel gear 24 and positioned at the tip of the wrist. By providing the main reduction gear R7 that drives the T-axis in this way around the bevel gear r24, the torque transmitted to the T-axis can be output directly from the main reduction gear 7, eliminating the need for gear tooth contact adjustment. , assembly is easy, and maintenance is also easy. Furthermore, the bevel gear 24 can be easily supported, and its strength and rigidity can be reduced, so that the tip of the wrist can be made light.

〔Effect of the invention〕

Thus, according to the present invention, compared to the first conventional example, since a spherical wrist cover is not required, the number of parts is reduced, and the load reaction force on the T-axis is returned to the B-axis by only one part of the deceleration. It doesn't come.

The swing angle of the B axis can be expanded from ±110° to ±150°.

Also, compared to the second prior example, the offset of the processing tool gripping part from the arm center line can be significantly reduced (for example, from 180m to 120#IIl
+60% reduction in size), maintenance J5 and easy assembly.

Furthermore, compared to the first conventional example and the second prior art example, it can be configured very compactly.

Therefore, the present invention greatly contributes to this field.

[Brief explanation of drawings]

Fig. 1 is a side sectional view of one embodiment of the present invention, Fig. 2 is a partially cutaway front view, Fig. 3 is a side sectional view of another embodiment of the invention, and Fig. 4 is a prior example. FIG. DESCRIPTION OF SYMBOLS 1...R axis output shaft, 2...B import force shaft, 3...T axis input shaft, 3a...input transmission shaft, 4a, 4b...high speed bevel gear for B axis, 5a,
5b...High-speed bevel gear for T@, 6...B-axis drive horse main reducer, 6a...Movable circular spline, 6b
... Fixed circular spline, 6C... Flex spline, 6d... Wave generator, 6e...
・Set screw, 7... Main reducer for T-axis drive, 7a...
Fixed circular spline, 7b...Fixed circular spline, C...Flex spline, 7d...Wave generator, 8...Low speed bevel gear for T@, 1
0... Arm, 11.12.13.14a, 14b,
15a, 15b, 15c, 16a, 16b, 31.32
- Bearing, 13a... Collar, 13b... Nut (external thread), 16c... Flat spring, 16d... Washer, 16e... Set screw, 17... Processing tool grip, 1
7a...B nut, 17b...set screw, 30...
・Torque arm. Applicant's Representative Sato - Male T-axis R-axis Figure 1 Figure 2

Claims (1)

[Claims] 1. An R-axis that rotates the entire wrist rotatably supported by the arm around an arm axis, and rotation around one axis that is supported by the R-axis and perpendicular to the R-axis. A B axis that tilts the freely supported wrist tip, and a T axis that rotates the processing tool grip of the wrist tip that is rotatably supported around the other axis that is supported by the R axis and perpendicular to the R axis. established,
Means for decelerating the T-axis and B-axis within the wrist using main reducers placed on the left and right sides of the center of the arm axis, means for decelerating the R-axis in advance at a portion other than the wrist, and an output of the B-axis. An industrial robot wrist mechanism, comprising: means for connecting the T-shaft fixing part and the T-axis fixing part using a torque transmitting member. 2. The wrist mechanism for an industrial robot according to claim 1, wherein the T-axis main reducer and the B-axis main reducer are arranged on the same central axis. 3. The wrist mechanism for an industrial robot according to claim 1, wherein the T-axis main reducer is arranged to be perpendicular to the B-axis main reducer and located at the tip of the wrist.