JPS6125787A - Pneumatically operated 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 a robot utilized as various industrial robots, and particularly to a pneumatically actuated robot equipped with a robot arm driven by a pneumatic motor.

(Prior art and its problems) A conventional pneumatically operated robot uses a vane-type pneumatic cylinder unit that is equipped with a vane-shaped swinging piston that swings within a certain angle range, and the robot arm is directly connected to the piston. However, the cylinder unit was configured to drive a robot arm. In such a conventional configuration, the Hoene-shaped piston of the cylinder unit and the robot arm swing together at the same angle.
Coupled with the compressibility of air pressure, it has been difficult to control the angle of the robot arm with high precision in the middle of the swing range. Furthermore, in order to hold the robot arm at a predetermined angle against the gravitational moment, it is necessary to use a braking means with a braking force capable of resisting the moment.

(Means for Solving the Problems) The present invention has been made to solve the conventional problems as described above, and its feature is that the swing axis of the robot arm is located in the robot arm. A second double planetary gear mechanism and a second planetary gear mechanism are installed in parallel in a concentric state, and the rotation of a pneumatic motor is attached to an arm support member that supports the robot arm in a concentric state with the arm swing axis. The pneumatically operated robot is configured to reduce speed by the first and second side planetary gear mechanisms and transmit the deceleration to the robot arm, wherein the second planetary gear mechanisms include an inner part fixed to the arm support member side. a toothed sun gear, an eccentric cam attached to a central drive shaft driven by the pneumatic motor, and a planetary gear rotatable around the eccentric cam and meshing with the internally toothed sun gear; The planetary gear mechanism includes an internal sun gear fixed to the robot arm side,
and a planetary gear meshing with the internal sun gear and rotating integrally with the planetary gear of the second planetary gear mechanism.

(Function) In the above-mentioned pneumatically operated robot, the rotation of the pneumatic motor is taken out in a decelerated state as a rotational motion accompanying the revolution of the planetary gear in the second planetary gear mechanism, and The rotational motion accompanying the revolution is extracted in a decelerated state as a fine rotational motion of the internal sun gear in the second planetary gear mechanism, and the fine rotational motion of the internal sun gear causes the robot arm to swing at a very slow speed. On the other hand, the first and second side planetary gear mechanisms are in a self-locking state against transmission from the pneumatic motor to the robot arm in a direction opposite to the direction of deceleration transmission (increasing transmission direction), and act on the robot arm. The gravitational moment caused by the robot arm is isolated from the pneumatic motor, and the robot arm is prevented from wandering due to the gravitational moment.

(Example) An example of the present invention will be described below based on the attached illustrative drawings.

In FIG. 1, reference numeral 1 denotes a rotary table rotatable around a vertical axis, which is rotatably supported on a base 2 and can be rotated in any direction forward or reverse by a rotation drive means within the base 2. . Reference numeral 3 denotes an intermediate movable member, which is movable back and forth in parallel to the rotary table 1 via a drive arm 4 and a posture holding arm 5, which together with the intermediate movable member 3 and the rotary table 1 constitute a parallel four-speed link. Supported. Reference numeral 6 denotes a movable end member, which is capable of vertically parallel movement to the intermediate movable member 3 via a drive arm 7 and a posture holding arm 8, which together with the movable end member 6 and the intermediate movable member 3 constitute a parallel four-speed link. Possibly supported. Reference numeral 9 denotes a pneumatic motor that swings the drive arm 4 back and forth with respect to the rotary table 1, and is attached to the rotary table 1. 10 is the intermediate movable member 3
It is a pneumatic motor that swings the drive arm 7 in the vertical direction relative to the movable intermediate member 3, and is attached to the intermediate movable member 3. Although not shown, a robot hand equipped with an appropriate driving actuator is attached to the movable tip member 6.

The pneumatically operated robot configured as described above has a rotary table 1
By appropriately combining the rotation of the drive arm 4 with respect to the rotary table 1, the longitudinal swing of the drive arm 4 with respect to the rotating table 1, and the vertical swing of the drive arm 7 with respect to the intermediate movable member 3, the tip movable member 6 is moved relative to the base 2. It can be moved to any position while keeping its posture constant.

Next, the means for driving the drive arm 7 with respect to the intermediate movable member 3 will be explained based on FIGS. 2 to 4. In the figure, 11 is a second double planetary gear mechanism, 12 is a second planetary gear mechanism, and these two inverted planetary gear mechanisms ++, 12 are installed in parallel at the base of the drive arm 7. Reference numeral 13 denotes a central drive shaft that passes through the base of the drive arm 7 in a state concentric with the swing axis of the drive arm 7. Both ends are supported by the intermediate movable member 3 via bearings 14, and one end is supported by the intermediate movable member 3. Output shaft 10a of pneumatic motor 10 attached to member 3
is directly connected to.

The second double planetary gear mechanism 11 includes an internal sun gear 15 fixed to the intermediate movable member 3 side concentrically with the central drive shaft 13, an eccentric cam 16 fixed at the center position of the central drive shaft 13, and It is comprised of a planetary gear 18 rotatably supported by the eccentric cam 16 via a bearing 17 and meshing with the internal sun gear 15. Said second planetary gear mechanism 1
2 includes an internal sun gear 19 fixed to the drive arm 7 concentrically with the central drive shaft 13; It consists of a planetary gear 21 meshing with a toothed sun gear 19.

Internal sun gear 15 in the second planetary gear mechanism 11
consists of a sprocket wheel 22 fixed to the intermediate movable member 3 side concentrically with the central drive shaft 13, and an endless chain 23 fitted and fixed around the entire circumference of the sprocket wheel 22. The chain 23a and 23b are integrally connected in parallel, and a portion of one chain 23a engages with the sprocket wheel 22. The planetary gear 18 of the second planetary gear mechanism 11 is composed of a sprocket wheel 24 having a slightly smaller diameter than the sprocket wheel 22, which engages with the chain 23b of the endless chain 23.

The internal sun gear 19 in the second planetary gear mechanism 12 includes a sprocket wheel 25 fixed to the drive arm 7 concentrically with the central drive shaft 13, and a sprocket wheel 25 fixed to the drive arm 7 in a concentric state with the central drive shaft 13
- Endless chain 26 fitted and fixed around the entire circumference of the wheel 25
The endless chain 26 is made up of two chains 26a and 26b connected together in parallel, with a portion of one chain 26a meshing with the sprocket wheel 25. Moreover, this second planetary gear mechanism 1
The second planetary gear 21 is composed of a sprocket wheel 27 having a slightly smaller diameter than the sprocket wheel 25 and meshing with the chain 26b of the endless chain 26.

Reference numeral 28 denotes a braking means, which includes a cone-shaped braked body 29 concentrically connected to the free end side of the central drive shaft 13, and a cone-shaped brake member 29 that is movable in a direction near and far relative to the cone-shaped braked body 29. A braking piston 30 having a braking surface 30a, a spring 31 that presses the piston 30 toward the cone-shaped braked body 29, and an air space that moves the piston 30 against the pressing force of the spring 31. Pressure chamber 32
It is equipped with a cylinder 32 that constitutes a. 33 is a guide shaft for stopping the rotation of the piston 300, and is fixed to the cylinder cover 32b.

According to the above configuration, normally, as shown in FIG.
is in a fixed state.

From this state, pneumatic pressure is supplied to the pneumatic chamber 32a of the braking means 28 to move the braking piston 30 backward against the pressing force of the spring 31, thereby separating the piston 30 from the cone-shaped braked body 29. After turning the central drive shaft 13 into a rotatable state, when pneumatic pressure is supplied to the pneumatic motor 10 and the central drive shaft 13 is rotated via its output shaft 10a, the eccentric cam 16 rotates and this As the eccentric cam 16 rotates, the sprocket wheel 2 corresponding to the planetary gear 18.21 in both the first and second inverted planetary gear mechanisms 11.12
4.27 integrally revolve around the axis of the central drive shaft 13.

On the other hand, the internal sun gear 1 in the second double planetary gear mechanism 11
Since the endless chain 23 corresponding to the internal teeth of No. 5 is fixed to the intermediate movable member 3 by the sprocket wheel 22, it is a planetary gear in which some of the teeth mesh with the chain 723b of the endless chain 26. The sprocket wheel 24 corresponding to No. 18 rotates around the axis of the central drive shaft 13 as the eccentric cam 16 rotates as described above, and simultaneously rotates around the axis of the eccentric cam 16.

The rotational motion of the sprocket wheel 24 is directly transmitted to the sprocket wheel 27 that is integrally connected to the sprocket wheel 24, and the sprocket wheel 27 also rotates along the axis of the central drive shaft 13 as the eccentric cam 16 rotates. The eccentric cam 16 is caused to rotate around the axis of the eccentric cam 16 at the same time as it revolves around the center. The rotational motion of the sprocket wheel 27 corresponding to the planetary gear 21 in the second planetary gear mechanism 12 is transmitted to the sprocket wheel 25 via the endless chain 26 corresponding to the internal teeth of the internal sun gear 19.

Here, if the number of teeth of the fixed sprocket wheel 22 (endless chain 23) is A1, the number of teeth of the sprocket wheel 24 is B, and the rotation speed of the central drive shaft 13 (eccentric cam 16) is No, then the rotation of the sprocket wheel 24 is The number N is N11 = (1-A/B) ・No. If A-36 and B-34 are used, then the number of rotations N of the sprocket wheel 24 and one rotation of the central drive shaft 13 in the positive direction are This results in approximately 0.0588 rotations in the opposite direction.

Furthermore, the number of teeth of the sprocket wheel 27 is C, the number of teeth of the sprocket wheel 25 (endless chain 26) is D,
If the same rotation speed is ND, the reduction ratio i of the sprocket wheel 25 with respect to the central drive shaft 13 is i = No/No = 1-A・C/B −D, and if C=32 and D=34. For example, the reduction ratio i = N
o/N o will be approximately 0.0035, and the central drive shaft 1
For every rotation in the positive direction of 3, the sprocket wheel 25 rotates approximately 0.0035 times in the same direction. Since this sprocket wheel 25 is fixed to the drive arm 7, when the sprocket wheel 25 rotates, the drive arm 7 swings in the vertical direction around the swing axis that is concentric with the central drive shaft 13. become. That is, the rotation of the central drive shaft 13 is caused by both the first and second inverted star gear mechanisms 11.
12, which has a very large reduction ratio, is transmitted to the drive arm 7 in a decelerated state, and the drive arm 7 is caused to swing up and down at a very slow speed.

Once the drive arm 7 is swung upward or downward by a predetermined angle, the supply of air pressure to the pneumatic motor 10 is cut off to stop the swing of the drive arm 7, but at the same time, the pneumatic chamber of the braking means 28 is By cutting off the supply of air pressure to the brake piston 32a, the braking piston 30 returns to its original position due to the pressing force of the spring 31, and its cone-shaped large concave braking surface 30a fits closely into the cone-shaped braked body 29, and the central drive shaft Fix 13,
The drive arm 7 is completely locked to the intermediate movable member 3.

Note that the deceleration means consisting of the first and second planetary gear mechanisms 1L12 is mechanically in a self-locking state with respect to the speed increasing transmission from the sprocket wheel 25 on the deceleration output side to the central drive shaft 13 on the input side. Even if the braking means 28 is not used together, the drive arm 7 will not naturally swing downward due to the gravitational moment acting on the drive arm 7.

In addition, as shown in FIG. 2, a balance weight 34 that is eccentric in the opposite direction to the eccentric direction of the eccentric cam 16 is attached to the eccentric cam 16 to reduce vibrations caused by eccentric rotation of the eccentric cam 16 and the like with respect to the central drive shaft 13. It is possible to solve problems such as

The deceleration drive means of the above embodiment can also be used as a means for driving the drive arm 4 with respect to the rotary table 1.

(Effects of the Invention) According to the pneumatically actuated robot of the present invention that can be implemented as described above, the rotation of the pneumatic motor is controlled by the speed reduction ratio of the second double planetary gear mechanism and the second planetary gear mechanism. It is transmitted to the robot arm via a large deceleration transmission means, and the robot arm is made to swing at a very low speed in response to the high speed rotation of the pneumatic motor, so it uses compressible air pressure to drive the robot arm. However, the swing angle of the robot arm can be controlled with high precision based on the rotation speed of the pneumatic motor. Further, even if a small pneumatic motor with a small drive torque is used, the drive torque acting on the robot arm can be greatly increased and the robot arm can be strongly swung, so it can also be used as a robot for heavy objects.

Further, both the first and second reverse star gear mechanisms are in a self-locking state in response to transmission from the pneumatic motor to the robot arm in the opposite direction (acceleration transmission direction) to the deceleration transmission direction, and the robot arm is in a gravitational Since the robot arm is prevented from wandering due to the moment, the robot arm can be reliably fixed and held at any position even if a braking means is not used.

Moreover, since the present invention has a substantially symmetrical deceleration transmission means installed in the base of the robot arm in a well-balanced manner, the entire robot can be constructed relatively compactly even though it is equipped with a deceleration transmission means with a large reduction ratio. obtain.

[Brief explanation of drawings]

FIG. 1 is an overall side view, FIG. 2 is an enlarged cross-sectional bottom view of essential parts, and FIGS. 3 and 4 are configuration explanatory diagrams of the first and second planetary gear mechanisms. 1... Turntable, 3... Intermediate movable member, 4.7...
Drive arm, 5.8... Arm for posture maintenance, 6...
Tip movable member, 9, 10... pneumatic motor, 11...
・Second planetary gear mechanism, 12... second planetary gear mechanism,
13... Central drive shaft, 15.19... Internal sun gear, 16... Eccentric cam, 18.21... Planetary gear, 2
2, 24.25.27... Sprocket wheel, 2
3.26... Endless check 7.28... Braking means. ”-t-=

Claims (2)

[Claims] (1) A first planetary gear mechanism and a second planetary gear mechanism are installed in parallel in a robot arm in a state concentric with the oscillation axis of the robot arm, and the arm oscillates on an arm support member that supports the robot arm. The pneumatically operated robot is configured to reduce the rotation of a pneumatic motor mounted concentrically with the shaft center and transmit the reduced speed to the robot arm by the first and second planetary gear mechanisms, the first planetary gear The mechanism is
an internal sun gear fixed to the arm support member side, an eccentric cam attached to a central drive shaft driven by the pneumatic motor, and an eccentric cam that is rotatable around the eccentric cam and meshes with the internal sun gear. Consists of planetary gears that
The second planetary gear mechanism includes an internal sun gear fixed to the robot arm, and a planetary gear that meshes with the internal sun gear and rotates together with the planetary gear of the first planetary gear mechanism. Pneumatically operated robot. (2) an internal sun gear of the first planetary gear mechanism, a sprocket wheel fixed to the arm support member;
It is composed of an endless chain having a part that fits around the entire circumference of the sprocket wheel and a part that projects laterally, and the internal sun gear of the second planetary gear mechanism is fixed to the robot arm side. sprocket wheel and
The sprocket wheel is composed of an endless chain having a part that fits around the entire circumference of the sprocket wheel and a part that projects laterally, and each planetary gear of both planetary gear mechanisms is connected to the side of the endless chain of the respective mechanism. The pneumatically actuated robot according to item (1) above, comprising a sprocket wheel that engages with the side overhang.