JPS62255092A - Stop mechanism for rocking 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 the Invention The present invention relates to a swing arm stop mechanism for smoothly stopping the rotation of an arm having the structure of, for example, an article gripping mechanism of an industrial robot.

BACKGROUND ART Conventionally, there have been mainly three types of stopping mechanisms used, for example, in industrial robots, for smoothly stopping a swinging arm rotated by a motor.

(1) Stopping mechanism using a servo mechanism A hydraulic swing motor or an electric servo motor rotates the swing arm. When the swing arm rotates to a predetermined position, a position detector detects this, and a servo controller stops the motor. A mechanism that controls the rotation of the swing arm and smoothly stops the swing arm.

However, this mechanism had the problem of high cost.

(2) Stopping mechanism using inverter control As shown in FIGS. 4 and 5, a swinging arm 12 is driven by an insulator motor 11 having a brake via a deceleration mechanism IO.
During the rotation, when the swing arm 12 rotates close to a predetermined stop position, the striker 13 protruding from the swing arm 12 comes into contact with the deceleration start detector 14, causing the induction motor 11 to shift from constant speed rotation to deceleration rotation. This slows down the rotation of the swing arm 12. Thereafter, the striker 13 contacts the end detector 15 to cut off the driving power to the induction motor 11, and also contacts the fixed end stopper 16 to stop the rotation of the swing arm 12.

In the case of FIG. 6, a braking start detector 17 and an end detector 18 are provided in this order instead of the end stopper 16, and after the striker 13 comes into contact with the deceleration start detector 14 and decelerates, When the induction motor 11 comes into contact with the braking start detector 17, the induction motor 11 is braked and finally stops at the end detector 18.

However, these mechanisms have the disadvantage that the stop position varies due to changes in the load on the arm.

(3) Stopping mechanism using an air swing motor The swing arm is rotated by the air swing motor, and when the swing arm is rotated to a predetermined position, the rotation of the swing arm is stopped by a valve.

In the case of this mechanism, the compressibility of air is high and it is difficult to control the rotation speed.

Means for Solving the Problems In order to solve the above problems, the present invention provides a swing arm stopping mechanism that includes a stopper on the swing arm that is rotated by a motor, and a signal for cutting off the motor power when activated. and a shock absorber with which the stopper balances when the swing arm rotates, and a collided portion with which the stopper collides after colliding with the shock absorber. , and a striker sensed by the detector, the above problem was solved.

Function: When the swing arm rotates before a predetermined stop position, the swing arm collides with the shock absorber via the stopper,
The inertia is absorbed by the shock absorber. Further, at the same time, the motor power is cut off and the arm is rotated by inertia, and then the brake is applied to accurately stop the swinging arm at a predetermined position.

Example Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 3, on a frame 20, there is an induction motor 21 (hereinafter referred to as a motor) having a brake, and a swing arm 25 that rotates in conjunction with the motor 21 via a pair of sprockets 22 and a chain 24. is the provision.

An overload protection device 27 is provided on the shaft 26 of the swing arm 25 to release the rotational force of the motor 21 by a slip action when an overload is applied to the swing arm 25.

As shown in FIGS. 1 and 2, a stopper 28 is provided on the surface of the swinging arm 25 facing the frame 20 through a pair of mounting bolts 29 and an elongated hole 30 so that its position can be adjusted.

A swing arm 2 is attached to the end of the stopper 28 to prevent loosening.
The adjustment bolt 32 that abuts on the fixing pin 31 on the frame 20 is fitted, and the plane facing the frame 20 has a balancing surface (
(slope) 33 is protruding. Further, a detector 34 buried in the swing arm 25 is integrally provided with the stopper 28 so that its sensor portion 34a protrudes.

On the frame 20, when the swing arm 25 rotates,
A shock absorber 36 having a spindle 35 that abuts against the abutment surface 33 of the stopper 28 that rotates together with the shock absorber 36 and a striker 37 that is sensed by a detector 34 are provided. The shock absorber 36 is formed with a balanced portion (slope) 38 with which the abutment surface 33 abuts.

Next, to explain the operation, as the swinging arm 25 rotates in the direction of arrow A in FIG. When the striker 37 contacts and further rotates, the sensor 34a of the detector 34 detects the striker 37 at a position 348 in FIG.

The power of the motor 21 is cut off by this signal, and the swing arm 25 then rotates only by inertia force.

However, since the swing arm 25 is in contact with the shock absorber 36 via the stopper 28, its inertia force is gradually absorbed by the shock absorber 36, and eventually the abutting surface (slanted surface) 33 of the stopper 28 becomes shock absorber 36. The rotation of the swing arm 25 is stopped by gently colliding with the abutted portion (slope) 38 of the absorber 36. If the brake is applied at this point, the arm 25 will be held in that position.

The stop position of the swing arm 25 can be adjusted by loosening the mounting port 29, adjusting the adjustment bolt 32 that is in contact with the fixing pin 31, and shifting the position of the stopper 28 using the elongated hole 30 as a guide. .

Note that the timing at which the abutment surface 33 of the stopper 28 comes into contact with the spindle 35 of the shock absorber and the timing at which the detector 34 senses the striker 37 may occur either first or at the same time.

Further, in the above embodiment, the position 34a of one detector 34 is
(Fig. 1), the motor power cutoff signal is obtained, and the end detection signal is obtained at the position 3 and 4b, and the brake is applied after a certain period of time from the point 34a. The former detector 34 may issue a motor power cutoff signal, and the latter detector 39 may issue a brake activation signal and an end detection signal.

Effects of the Invention As described above, the present invention allows the swinging arm to be smoothly decelerated, braked, and stopped, thereby eliminating the impact generated when the swinging arm stops, thereby preventing an adverse effect on the entire device. Can be done.

Furthermore, since the detector is integrated with the stopper, the stop position can be easily changed by changing the position of the stopper while maintaining the above effects.

Furthermore, the mechanism is inexpensive and easy to control.

[Brief explanation of drawings]

Figures 1 to 3 are examples of the present invention, Figures 4 to 6 are conventional examples, Figure 1 is a sectional view taken along I--■ in Figure 2, and Figure 2 is the left side of Figure 1. Figure 3 is a sectional view taken along the line ■-■ of Figure 1, Figure 4 is a schematic diagram of the whole, and Figures 5 and 6 are only the left and right halves of the right side view of Figure 4. These are conventional examples that are different from each other. 21... Motor 25-... Swing arm 2
0... Frame 28... Stopper 33.
... Balance surface 34 ... Detector 36 ... Shock absorber 37 ... Striker 38 ... Collision target t-P
Agent: Patent attorney Yuyosuke - 2 others Figure 2 Figure 1 ■ Figure 5

Claims (2)

[Claims] (1) A stopper and a detector that outputs a signal to cut off the motor power when activated are provided on the swinging arm that is rotated by the motor, and the stopper is mounted on the frame when the swinging arm is rotated. Shock absorbers that collide,
A swing arm stopping mechanism, characterized in that the stopper includes an abutted portion that abuts against the shock absorber after the stopper abuts against the shock absorber, and a striker that is sensed by the detector. (2) The swing arm stopping mechanism according to claim 1, wherein the stopper is adjustable in position.