JPS6125795A - Brake gear for robot arm - 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 braking device used for fixing a swinging arm in an industrial robot at a predetermined position.

(Prior art and its problems) A conventional robot arm braking device, in particular, presses a brake plate against a braked surface using the biasing force of a spring, and applies the brake by fluid pressure supplied to a cylinder unit directly connected to the brake plate. In a braking device in which the brake is released by separating the disc from the surface to be braked, a large braking force cannot be obtained unless the spring is extremely strong, so in practice, A type of braking device that uses the biasing force of a spring for braking is inappropriate for robot arm braking in robots/toshis that are used in public. Also, even if a large braking force is obtained by using a powerful spring ring, in order to release the brake against the urging force of the spring, it is necessary to apply a force t1 to the urging force of the spring.
It is necessary to resupply the cylinder unit with a high enough fluid pressure to overcome the problem, which has the drawback of increasing the cost of the entire braking device including the fluid pressure supply system.

(Means for Solving the Problems) The present invention has been made to solve the above-mentioned conventional problems, and its feature is that the robot arm or the robot arm pivot member is A cylinder uni-nod equipped with a piston that moves in a direction substantially perpendicular to the swing axis of the arm, and a pair of left and right brake discs that move in and out in a direction parallel to the swing axis of the robot arm are provided. A toggle link mechanism is provided in which a pair of left and right brake discs and a piston in the cylinder unit are moved in conjunction with the forward and backward movements of the pistons to cause the re-brake discs to move forward to move away from each other and to move to move closer to each other. A spring is provided which urges the piston in the direction of advancing and moving the pair of left and right brake discs, and the robot arm pivot member or the robot arm is provided with a spring that is interlocked and connected through the brake discs and urges the piston in the direction of advancing and moving the pair of left and right brake discs. The point is that a pair of left and right braked surfaces are formed.

(Function) In the above braking device, the biasing force of the spring is greatly increased by the toggle link mechanism and acts on the pair of left and right brake discs in a pushing direction, and the re-brake discs are applied to the opposing pair of brake discs. The robot arm is fixed to the robot arm pivot member by pressing against the braking surface in opposite directions. Furthermore, by supplying fluid pressure to move the piston of the cylinder unit against the biasing force of the spring, the pair of left and right brake discs are simultaneously retracted against the biasing force of the spring via the toggle link mechanism. It is thicker and separates from the surface being braked to release the brake.

(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 supported by the rotary table 1 via a longitudinal swing arm 4 so as to be movable longitudinally and in parallel. The longitudinal swinging arm 4 is connected to a drive link 5 parallel to each other, which forms a parallel link with the rotary table 1 and the intermediate movable member 3.
and a posture maintaining link 6. Reference numeral 7 denotes a distal end movable member, which is supported by the intermediate movable member 3 via a vertically swinging arm 8 so as to be vertically movable in parallel. The vertically swinging arm 8 is composed of a mutually parallel driving link 9 and a posture holding link 10, which together with the intermediate movable member 3 and the distal end movable member 7 constitute a parallel recirculating link. Reference numeral 11 denotes a pneumatic motor that swings the back-and-forth swinging arm 4 in the front-rear direction with respect to the rotary table 1 via the drive link 5, and is attached to the rotary table 1.

Reference numeral 12 denotes a pneumatic motor that swings the vertically swinging arm 8 in the vertical direction relative to the intermediate movable member 3 via the drive link 9, and is attached to the intermediate movable member 3. A robot hand equipped with an appropriate drive actuator (not shown) is attached to the tip movable member 7. Arm 4 against
By appropriately combining the back and forth rocking of the arm 8 and the vertical rocking of the arm 8 relative to the intermediate movable member 3, the tip movable member 7 can be moved to an arbitrary position while keeping its posture constant relative to the base 2. I can do it.

Next, a braking device of the present invention will be described based on FIGS. 2 to 4, which is implemented as a braking device for braking the drive link 9 of the vertically swinging arm 8 with respect to the intermediate movable member 3.

Reference numeral 13 denotes a cylinder unit, in which a rear end portion 9a of the link protrudes rearward from the swing axis 14 of the drive link 9.
The piston 15 is installed internally in such a direction that the moving direction thereof is perpendicular to the swing axis 14. 16a, 16
b is a pair of left and right brake discs, and the link rear end portion 9a
A pair of left and right slide guides 1 that protrude further rearward from
7a.

17b, they are held concentrically and movable in a direction parallel to the swing axis 14. 18, the piston 15 in the cylinder unit 13 is inserted into the inner 19
The spring is interposed between the piston 15 and a bracket 20 attached to the rear end portion 9 of the link. A piston rod 21 has an inner end connected to the piston 15, and is held through a front guide 22 fixed to the bracket 20 so as to be movable in and out. Reference numeral 23 denotes a toggle link mechanism including a pair of links 24a and 24b, the inner ends of which are connected to a support shaft 25 common to the outer end of the piston rod 21.
The outer ends of both links 24a and 24b are
A support shaft 26a is provided at the center of the back surface of the brake discs 16a and 16b, respectively.
, 26b. 27a and 27b are braked surfaces, which are opposing inner surfaces of the left and right side walls 3a and 3b of the intermediate movable member 3, and the brake plate 16a.

The swing axis 14 of the drive link 9 is located at a position opposite to the drive link 16b.
It is formed in a concentric arc shape.

In the braking device configured as described above, the biasing force of the spring 18 that biases the piston 15 inward 19 is
A pair of left and right brake discs 16 are connected via a pair of links 24a and 24b of a piston rod 21 and a toggle link mechanism 23.
a, 16b in an advancing direction 28 that is spaced apart from each other. The pressing force acting on the brake discs 16a, 16b in the advancing direction 28 is much larger than the biasing force of the spring 18 due to the force-increasing action of the toggle link mechanism 23. As a result, the pair of left and right brake discs 16a
, 16b are in pressure contact with the braked surfaces 27a, 27b of the intermediate movable member 3, thereby fixing the drive link 9 to the intermediate movable member 3.

When operating the pneumatic motor 12 to vertically swing the vertically swinging arm 8 relative to the intermediate movable member 3, at the same time or just before supplying pneumatic pressure to the pneumatic motor 12, pneumatic pressure is supplied to the cylinder unit 13. is supplied to the cylinder chamber +33, and the piston 15 is moved outward 29 against the biasing force of the spring 18. As a result, the pair of left and right brake discs 16a, 16b are drawn toward each other in the retraction direction 30 via both links 24a, 24b of the toggle link mechanism 23, and are separated from the braked surfaces 27a, 27b of the intermediate movable member 3. , the brake on the drive link 9 is released.

Note that, contrary to the above embodiment, the braked surface 2 is provided on the drive link 9 side.
It is also possible to provide the cylinder unit 13, the toggle link mechanism 23, and the pair of left and right brake discs 16a and 16b on the intermediate movable member 3 side.

In addition, in the robot shown in FIG. 1, the braking device of the present invention may be interposed between the drive link 9 and the movable tip member 7, or the braking device of the present invention may be interposed between the posture maintaining link 10 and the intermediate movable member 3 or the movable tip member. It can also be interposed between 7 and 7. Of course, the braking device of the present invention can also be installed at an appropriate location on the longitudinal swing arm 4 in the same manner as described above.

(Effects of the Invention) According to the robot arm braking device of the present invention which can be implemented as described above, although the braking force is obtained by the urging force of the spring, the urging force of the spring is reduced by interposing the toggle link mechanism. can be sufficiently increased, so even if a relatively weak spring is used, a large braking force can be obtained.

In other words, the pressure of the fluid pressure supplied to the cylinder unit for releasing the brake is relatively low compared to the magnitude of the braking force, so the entire braking device including the fluid pressure supply system can be constructed at a low cost. obtain.

Moreover, the toggle link mechanism for increasing the biasing force of the spring also serves as a means for converting the direction of movement of the piston of the cylinder unit and the direction of movement of the left and right brake discs into a perpendicular relationship with each other. Compared to the case where a cylinder unit is interposed between the brake discs, the distance between the split discs can be reduced. Therefore, it is convenient to install it inside a narrow robot arm.

Furthermore, since the pair of left and right brake discs performs the braking action so as to tighten between the braked surfaces, no thrust force in the direction of the robot arm swing axis is applied between the robot arm and the robot arm pivoting member during the braking action. . Therefore, there is no need to incorporate a structure specifically dealing with thrust force into the robot arm pivot portion.

[Brief explanation of drawings]

FIG. 1 is a side view of the entire pneumatically actuated robot, FIG. 2 is a cross-sectional plan view of the main parts, FIG. 3 is a longitudinal cross-sectional side view of the main parts, and FIG. 4 is a longitudinal cross-sectional rear view of the main parts. DESCRIPTION OF SYMBOLS 1... Rotating table, 3... Intermediate movable member, 4... Front-rear swing arm, 5.9... Drive link, 6.10...
Posture holding link, 7... Tip movable member, 8... Vertical swing arm, 11.12... Pneumatic motor, 13.
...Cylinder unit, 14...Arm swing axis,
15...Piston, +6a, 16b-Brake plate, +7a
, +7b...Slide guide, 18...Spring, 21...Piston Roff F, 23...Toggle link III, 24a, 24b=-link, 25.26a
, 26b-support shaft, 27a, 27b...braked surface. Figure 3 Figure 4

Claims (1)

[Claims] The robot arm or the robot arm pivot member includes a cylinder unit equipped with a piston that moves in a direction substantially perpendicular to the swing axis of the robot arm, and a cylinder unit that moves in and out of the robot arm in a direction parallel to the swing axis of the robot arm. A pair of brake discs are provided, and the left and right pair of brake discs and the piston in the cylinder unit are connected to each other in conjunction with the movement of the piston in advance and retraction, in which the brake discs move away from each other and retract towards each other. A spring is provided that is interlocked and connected via a toggle link mechanism that causes the robot arm to move in and out, and that biases the piston in a direction that moves the pair of left and right brake discs in a direction that moves the brake discs forward. . A braking device for a robot arm, comprising a pair of left and right braked surfaces facing the pair of left and right brake discs, respectively.