JPH0985675A - Robot with repulsive mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily stop an article conveying device by providing an elastic material on which a stopper meeting projection abuts so as to pressurize and which adsorbs the turning force in stopping of the horizontal arm drive lever, when an article holding device is moved in the adjacent to a stop position. SOLUTION: Stopper meeting projection 6-1 of a horizontal arm drive lever 6 abuts on a polyurethane rubber seat 12 so as to start to compress repulsive coil spring 11, and as a vacuum suction pad 8 gradually approaches to a terminal for sucking to a material 9 to be conveyed, the repulsive force is increased so as to help a brake of the horizontal arm drive lever 6. When the vacuum suction pad 8 abuts on the material 9 to be carried, the suction is quickly started and when it is inverted and raised, the repulsive coil spring 11 compressed by the vacuum suction pad 8 during its stopping rapidly repulses so as to help the raising largely.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a robot for article transportation, or a robot provided with a repulsion mechanism provided with an auxiliary acceleration mechanism effective for increasing the speed of a repetitive transportation tool or the like.

[0002]

2. Description of the Related Art Conventionally, in order to convey articles by a robot,
The article gripping device attached to the tip of the arm attached to the robot is brought close to the article at the transport start position and stopped to securely grip the article, and then the arm is moved to the transport complete position and stopped. A method is used in which the articles are conveyed in a cycle of releasing the articles and further returning them to the conveyance start position. For this reason, in the article transportation cycle, a force to move the arm is required when the arm holding the article is lifted, and the arm is stopped in order to bring the article-holding device close to the article and stop the article-holding position. It needs the power to make it.

That is, in general, in a robot for carrying articles, the article gripping device attached to the tip of the arm is decelerated when approaching the article, stopped near the article, and the operation of gripping the article is performed. It is necessary to accelerate and transfer the article gripping device in the lifting direction of the article, and a large torque is required in the negative and positive directions when the arm including the article gripping device is switched between stop and start. In particular, when the arm holding the article is lifted, the article may be added to the weight of the arm and the article holding device, and the weight may increase.
The acceleration (torque) required for lifting these is generally the largest in one cycle of the transfer cycle, and the limit of the ratio torque influences the time of one cycle, which is the limit for speeding up the article transfer by the robot. It was

[0004]

SUMMARY OF THE INVENTION The present invention provides a drive device having the same function by reducing the torque when the arm is lifted after gripping an article, which is the limit of the speeding up of the article transportation by the conventional robot. An object of the present invention is to provide a robot having a repulsion mechanism capable of speeding up the transportation of articles.

[0005]

Therefore, the robot provided with the repulsion mechanism of the present invention has the following means. (1) An article holding device is connected to one end of a horizontal arm provided at the other end to form a link mechanism, and a vertical arm for moving the article holding device and a horizontal arm drive link are connected to the tip. The horizontal arm drive lever is provided with a rotation shaft for rotating each base end of the horizontal arm drive lever, and the rotation force of the horizontal arm drive lever is transmitted to the base via an elastic material to provide a stopper for restricting the rotation. Provided. (2) A horizontal arm that connects the horizontal arm to the tip when the article gripping device provided at the other end of the horizontal arm is transferred to the vicinity of the stop position for gripping the article to be conveyed or releasing the gripped article The horizontal arm drive lever is provided with a stopper abutting protrusion for restricting the rotation of the horizontal arm drive lever by abutting against the elastic material at the tip of the horizontal arm drive lever. (3) When the article gripping device approaches the vicinity of the stop position, the stopper abutment protrusion provided at the tip of the horizontal arm drive lever causes compression or extension deformation, and this deformation causes the horizontal arm drive lever to rotate. The other end, which absorbs power and is connected to the horizontal arm drive lever via the horizontal arm drive link, stops the movement of the horizontal arm provided with the article holding device and moves the article holding device from the stop position. At this time, it deforms into a stopper contact protrusion and urges the restoring force held inside to assist the rotation of the horizontal arm drive lever,
The stopper is provided with an elastic material that accelerates the movement of the horizontal arm.

In the robot equipped with the repulsion mechanism of the present invention, by means of the above-mentioned means, when the article gripping device approaches an article to be conveyed, for example, a horizontal arm for transporting the article gripping device is moved by rotation so as to move horizontally. A stopper contact projection provided at the tip of the arm drive lever contacts the elastic material.

Due to the deformation of the elastic material due to this abutment, the inertial force of the horizontal arm or the like is absorbed to assist the stop torque of the arm drive motor for rotating the horizontal arm drive lever. A large braking force acts, and the horizontal arm that moves by this rotation easily stops.

Further, after the article gripping device grips the article,
When the horizontal arm is moved and lifted, the starting torque of the arm drive motor is assisted by the deformation energy accumulated in the deformed elastic material, so a large turning force acts on the horizontal arm drive lever. The article gripping device that moves dynamically can move at high speed.

As a result, the article gripping device is brought closer to the article to be conveyed, stopped at the position for grasping the article, grasped the article, moved to the article conveyance position, and released from grasping the article, a so-called conveyance cycle. It is possible to shorten the time per cycle and to speed up the transportation of articles by the robot even by using the drive device having the same function.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a robot having a repulsion mechanism of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of a robot equipped with the repulsion mechanism of the present invention.
It is a figure which shows the whole main part as a form. In addition, in this figure, it is assumed that the article 9 to be conveyed as an article is lifted upward from the initially set conveyance start position A, passes through the conveyance intermediate point C, and is conveyed to the conveyance completion position B.

A robot 20 equipped with a repulsion mechanism according to the present invention comprises a pedestal 1 which is a fixed part, a vertical arm 2 whose base end is pivotally attached to a rotary shaft 17 which is laterally mounted on the gantry 1, and the same rotary shaft 17, a horizontal arm drive lever 6 whose base end is pivotally attached, a horizontal arm drive link 7 whose base end is pivotally attached to the tip of the horizontal arm drive lever 6, and an article gripping device at the other end (tip) And a vertical arm 2 is pivotally attached to one end (base end) of the horizontal arm drive link 7, and the vertical arm 2 is provided between the pivot points.
Horizontal arm drive lever 6 and horizontal arm drive link 7
The main part is constituted by the horizontal arm 5 that is operated by a parallelogram linkage mechanism formed by.

For this reason, when the vertical arm 2 is rotated counterclockwise in the figure, the horizontal arm 5 is simultaneously rotated clockwise to transfer the vacuum suction pad 8 to the transported object 9 as an article. Can be moved directly above. The method of guiding the vacuum suction pad 8 to an accurate position is similar to that of the drive mechanism of a commonly used articulated robot.
An angle indexing encoder, a servo motor, a control program, and the like are used, and a description thereof will be omitted.

The vacuum suction pad 8 is connected to a flexible vacuum pipe, an electromagnetic valve, and a vacuum pump, which are not shown, and has an ability to suck the transported object 9 almost instantly. As described above, the vertical link 2 is connected to the horizontal arm 5 by a pin joint at the upper joint 19 forming the link mechanism, and the base end has a rotary shaft having the same center of rotation as the horizontal arm drive lever 6. A vertical arm drive lever 3 and a vertical arm drive link 4 which are pivotally attached to the base 17 and are driven by an electric motor (not shown) provided on the gantry 1 and a speed reducer, and the rotary shaft 17
It can be rotated around.

The end of the horizontal arm 5 which is the other end is rotatably connected to the L-shaped metal fitting 18 to which the vacuum suction pad 8 is attached by a pin, and as described above, the base end which is the one end. Are held rotatably around the upper joint 19 of the vertical link 2. Further, the end of the upper joint 19 is pin-joined to the end of the horizontal arm drive link 7 that drives the upper joint 19, as described above, and these are motors for rotating the vertical arm 2 (not shown). ,
A parallel link is formed by the electric motor different from the speed reducer and the horizontal arm drive lever 6 driven by the speed reducer.

The L-shaped metal fitting 18 for attaching the vacuum suction pad 8 to the horizontal arm 5 is pin-joined to the posture holding link 16 above the pivot point of the horizontal arm 5 to form two parallel sets. It is the same as the conventional one that the L-shaped metal fitting 18 is always kept in a constant posture by the link.

FIG. 1 shows the moment when the vacuum suction pad 8 is sucked onto the transported object 9. At this time, the stopper contact protrusion 6-1 provided at the tip of the horizontal arm drive lever 6 is a buffer urethane rubber. The rubber spring holder 13 with a guide bar (see FIG. 2) hits the seat 12, and the repulsion coil spring 11 as an elastic material is compressed by the shoulder portion.

Next, the rotation of the horizontal arm drive lever 6
Alternatively, a device for assisting the stop will be described in detail with reference to FIGS. On the side of the tip of the horizontal arm drive lever 6,
As shown in FIG. 3, a stopper contact protrusion 6-1 is provided so as to project. The stopper contact projections 6-1 are provided at positions corresponding to the stoppers of the stopper bracket 10 attached to the pedestal 1, that is, the cushioning urethane rubber seats 12 and the like.

The repulsion mechanism is mounted on the pedestal 1 coaxially with the horizontal arm drive lever 6 so that the angle can be varied.
4, a stopper bracket 10 for holding 4 and a cushioning urethane rubber seat 12, and a guide bar-equipped rubber seat holder 13, a guide bar-equipped rubber seat holder 13 and a slide bush 14 which are incorporated so as to be slidable in the slide bush 14 in the axial direction. As shown in FIG. 2, a repulsive coil spring 11 as an elastic body, which is installed between the elastic member and the elastic member, and acts as a stopper at the time of expanding the repulsive coil spring, is incorporated and configured. ing. Further, the stopper bracket 10 is configured so that the end point of compression can be arbitrarily adjusted by the concentric arcuate elongated holes 10-1 so as to meet the conditions such as the position of the transported object and the strength of the spring force.

Next, the relationship between the movement of the robot 20 and each part will be described. When the vacuum suction pad 8 is first approached, the movement of the horizontal arm 5 is large because the vacuum suction pad 8 moves substantially vertically downward, and the vertical arm 2 moves slowly. It will be a movement. Further, in the vicinity of the end of approaching the transported object 9 transported by the vacuum suction pad 8, it is necessary to exert a large breaking force on the horizontal arm 5 in order to stop it soon.

Therefore, in the case of the robot 20 of the present embodiment, the stopper abutting projection 6-1 of the horizontal arm drive lever 6 hits the urethane rubber seat 12 to start compressing the repulsive coil spring 11, and the vacuum suction pad 8 is covered. The repulsive force increases as the end point of adsorbing to the conveyed product 9 is approached, and the braking of the horizontal arm drive lever 6 is assisted. This assisting of the brake brings the transported object 9 to the transport completion position B by holding the transported object 9 because the vacuum suction pad 8 is empty and approaches the transported object 9 when picking up the transported object 9. The effect is great when approaching.

Now, when the vacuum suction pad 8 hits the object 9 to be conveyed, suction starts immediately and when it is reversed and lifted, a sufficient suction force must be exerted. For this reason, specifically, even after the vacuum suction pad 8 hits the transported object 9, the vacuum suction pad 8 may be slightly overstroked to increase the suction time or adjust the mounting angle to cause almost instantaneous suction. I can. At the start of lifting, sudden acceleration is required and in most cases the maximum torque is required during the entire stroke. However, at this time, the repulsion coil spring 11 compressed when the vacuum suction pad 8 is stopped repulses rapidly and gives a great help to lifting. When approaching the point B at which the object to be conveyed 9 is completed, it starts to work as a brake again, releases the object to be conveyed, and the horizontal arm 5 moves to the position A to start the conveyance.
As described above, the assistance is given when returning to the point again.

In this embodiment, an example in which the transported object 9 is transported to a position of almost the same height at the horizontal position has been described. However, when there is a difference in height, it serves as a stopper at the lower position. The color 15 may be matched. In addition, when the vertical angle of the vertical arm 2 is large, a similar repulsion mechanism may be provided for the vertical arm 2 to be effective.
In either case, due to the repulsive force of the repulsion coil spring 11,
This helps to assist the brake of the horizontal arm drive lever 6 that moves the vacuum suction pad 8 that conveys the transported object 9 and the rotational torque for acceleration. Further, various applications of this embodiment are possible.

Next, as an example of the present embodiment, the vertical arm 2 and the horizontal arm 5 both carry 2 kg of the transported object 9 for 70 minutes at the tip of a two-joint robot having a joint length of 0.75 m.
The case of transporting once will be described. With such a robot 20, the torque required to drive the horizontal arm 2 when lifting the transported object 9 is about 450 N · m.

As described above, the repulsion coil spring 11 having a free length of 240 mm, an outer diameter of 35 mm and an inner diameter of 20 mm is provided so as to work at the top dead center of the horizontal arm drive lever 6, that is, at the point of gripping and lifting the transported object 9. If a stopper is applied to the horizontal arm drive lever 6 from 36 mm before the turning point and the repulsion coil spring 11 is compressed by 36 mm, a repulsion force of about 880 N is generated. Since the stopper is located at a radius of 0.25 m, it assists the length by 220 N · m, and it was possible to reduce the instantaneous torque required by the drive engine. Conversely speaking, the weight of the goods to be conveyed can be increased or the speed can be further increased.

[0025]

As described above, according to the robot provided with the repulsion mechanism of the present invention, when the article gripping device approaches an article to be conveyed by the configuration shown in the claims,
When the vicinity of the stop position is reached, a stopper abutting protrusion provided on the tip of the horizontal arm drive lever that moves the horizontal arm that transfers the article gripping device by rotation makes contact with the elastic material and deforms the elastic material. Due to this deformation, the inertial force of the horizontal arm or the like is absorbed and a deceleration action is generated.

As a result, the stop torque of the arm drive motor for rotating the horizontal arm drive lever is assisted.
A large braking force acts on the horizontal arm drive lever, and the horizontal arm that operates by the rotation of the horizontal arm drive lever, that is, the article transporting device can be easily stopped. In addition, when the article gripping device grips the article and then moves from the stop position, such as when moving the horizontal arm to lift the article,
Since the rotation torque of the arm drive motor is assisted by the deformation energy of the elastic material that is deformed when stopped, a large turning force acts on the horizontal arm drive lever, and the article gripping device that moves with this turning force moves at high speed. Can be made.

As a result, it is possible to shorten the time per one transfer cycle, and it is possible to speed up the article transfer by the robot even by using the drive device having the same function.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part showing a first embodiment of a robot having a repulsion mechanism of the present invention,

2 is a BB view of FIG. 3 showing the repulsion mechanism of the embodiment shown in FIG.

3 is a view taken along the arrow AA of FIG. 2 showing a drive relationship with the repulsion mechanism shown in FIG.

[Explanation of symbols]

1 cradle 2 vertical arm 3 vertical arm drive lever 4 vertical arm drive link 5 horizontal arm 6 horizontal arm drive lever 6-1 stopper abutment 7 horizontal arm drive link 8 vacuum suction pad (transport start position) 8'as an article gripping device Vacuum suction pad (conveyance completion position) 9 Conveyed object as an article (conveyance start position) 9'Conveyed object (conveyance completion position) 10 Stopper bracket 10-1 Stop position adjusting slot 11 Repulsive coil spring as an elastic material 12 Buffer urethane rubber as stopper 13 Rubber seat holder with guide bar 14 Slide bush 15 Collar 16 Position holding link 17 Rotating shaft 18 L-shaped metal fitting 19 Upper joint 20 Robot A Transport start position of transport target B Transport target Transport complete position C Transport intermediate point of the transported object

Claims (1)

[Claims] 1. A vertical arm having a base end portion pivotally attached to a pedestal so as to be rotatable, a horizontal arm drive lever having a base end portion pivotally attached coaxially with the vertical arm and being rotatable, and the horizontal arm. A horizontal arm drive link whose base end is pivotally attached to the front end of the drive lever and which forms a link mechanism with the vertical arm,
An article connected to the other end of the horizontal arm, one end of which is a pivot arm pivotally connected to the tip ends of the vertical arm and horizontal arm drive links, respectively, and which is moved by the rotation of the vertical arm and horizontal arm drive levers. In a robot that grasps and conveys an article with a grasping device, a stopper installed on the gantry, a stopper abutting protrusion provided on a tip end portion of the horizontal arm drive lever, and a stopper attached to the stopper, When it is moved to the vicinity of the stop position, the stopper abutting projection comes into contact with and presses, absorbing the turning force when the horizontal arm drive lever is stopped,
A robot provided with a repulsion mechanism, characterized in that when the article gripping device is moved from a stop position, an elastic material that applies a turning force absorbed to the horizontal arm drive lever is provided.