JP2680128B2 - Work gripping device using a rotating body - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to improvement of wear resistance and positioning of a claw portion of a gripping device used for a robot hand or the like.

[Prior Art] As a conventional work gripping device used for a robot hand or the like, devices having various structures have been developed according to the purpose, but generally, a large gripping force, work positioning property, and Manufactured in consideration of wear resistance. A plurality of metallic claw-shaped members and metal scissors-shaped members are often used as the member for gripping the leak.

[Problems to be Solved by the Invention] However, according to these methods, since the tips of the claw portions that come into contact with the workpiece come into contact with each other at almost the same portion, the contact members wear quickly. In addition, the workability and the gripping force are reduced due to the deformation of the claws due to wear.

The present invention is based on the above findings, and it is an object to be solved to reduce the wear of the contact portion with the work and to improve the grip performance.

[Means for solving the problem]

The above-mentioned problems are solved by a work holding device using a rotating body having the following features.

That is, the work holding device using the rotating body according to the present invention includes a work stopper that supports the work from one side by the receiving surface and a plurality of claws that move from the periphery of the receiving surface toward the center when holding the work. And a rotating body that is attached to the tip of the claw part and that can move following the receiving surface or substantially parallel to the receiving surface and that supports the work from the opposite side of the receiving surface at the work gripping position, The rotating body rolls on the receiving surface or the work surface before reaching the work gripping position.

[Action]

According to the present invention, the work is first supported on one side by the receiving surface of the work stopper. Next, by moving the plurality of claws from the periphery toward the center, the work is regulated from the side opposite to the receiving surface by the rotating body mounted on the claws. That is, the rotating body only moves to the holding position following the receiving surface or substantially parallel to the receiving surface, and does not move in the direction perpendicular to the receiving surface. Therefore, the rotating body is not strongly pressed against the work, and compared with the method of directly sandwiching and grasping the work between the claw portion and the claw portion or between the rotating body and the rotating body, the claw portion can be grasped. The gripping force can be reduced.

Further, since the rotating body rolls on the receiving surface or the work surface before reaching the workpiece gripping position, the contact portion of the rotating body with respect to the workpiece changes each time the workpiece is gripped. Therefore, the wear of the rotating body becomes uniform and the work is less likely to be damaged.

Further, since the plurality of claw portions including the rotating body move from the periphery of the receiving surface toward the center, the work is always gripped by the rotating body at the center of the receiving surface.

Further, since the work is supported by the plurality of rotating bodies and the receiving surface, the shape of the work is loosened to some extent.

[Examples] Examples will be specifically described below with reference to the drawings. First
FIG. 1 is a plan view of a first embodiment of a work holding device using a rotating body according to the present invention, and FIG. 2 is a side view thereof. In the figure
20 is a chuck.

The chuck 20 reciprocates an internal piston by the pressure of air supplied from the outside, and transmits the movement to the movable portion 22. Details of the transmission will be described later.

There are three movable parts 22 of the chuck, the work stopper 10
Are located at equal angles to each other and move simultaneously in the direction of the center of the circle or in the direction of the outer circumference of the circle by the movement of the piston inside the chuck 20.

Reference numeral 6 in the drawing denotes a claw portion connected to the movable portion 22 of the chuck, and a cylindrical rotating body 8 is rotatably fixed to the tip by a fulcrum pin 12.

The work stopper 10 is the work 2 to be gripped.
By receiving the receiving surface 10u, it serves to support it from one side.

FIG. 3 is a side view showing the operation of holding the work 2 by the work holding device using the rotating body according to the first embodiment.

First, the work 2 is brought into contact with the receiving surface 10u of the work stopper 10 or held with a slight gap. Next, compressed air is sent to the port of the chuck 20 in the closing direction. The compressed air causes the pistons in the chuck to move, and the three movable parts 22 move in the direction of the center of the circle. A detailed description of the operation will be given later. Since the claw portions 6 to which the rotating bodies 8 are attached are fixed to the three movable portions 22, the work 2 is pushed by the three rotating bodies from the outer peripheral direction, and the work stopper is provided.
It is pressed against 10 and fixed. Here, the movable parts 22 of the chuck are positioned at equal angles to each other on the same circle, and since the three units simultaneously move toward the center, the work 2 is moved to the center and positioned.

To release the grip, compressed air is sent to the opening port of the chuck 20. This compressed air causes the piston in the chuck to move in the opposite direction to move the movable portion 22 in the outer circumferential direction of the circle. Therefore, the rotating body 8 is separated from the work 2.

The rotating body 8 has an advantage that it wears less because the portion contacting the work 2 changes every time. This is because the contact portion changes due to the rotation of the rotating body 8 particularly when the work 2 is moved around the center.

FIG. 4 is a detailed sectional view of the chuck 20 used in the first embodiment.

In the figure, 24 is a piston. The piston 24 reciprocates in the cylinder block 25 downwards in the drawing by compressed air input from the port 40 in the closing direction and upwards in the drawing by compressed air input from the port 42 in the opening direction. . At the tip of the piston 24 is a rack with uneven teeth on the side surface.
26 is fixed by a screw 28. The concave and convex teeth of the rack 26 are fitted with the gear 30 to move the piston 24 up and down.
Is converted into rotational motion. The gear 30 is rotatably fixed to the chuck body by a pin 32.

In the figure, reference numeral 22 denotes the movable portion of the above-mentioned chuck, which has concave and convex teeth on the bottom surface. The concavo-convex teeth are fitted with the gear 30 to convert the rotational movement of the gear 30 into horizontal movement. Therefore, when the piston 24 moves downward, the movable part 22 moves to the right in the drawing, that is, toward the center, and when the piston 24 moves upward, the movable part 22 moves to the left in the drawing, that is, toward the outside. Move to.

Reference numeral 36 in the figure is an O-ring and functions to prevent leakage of compressed air.

FIG. 5 shows a state where the work holding device using the rotating body according to the first embodiment holds the work 2 having a taper. In this case, the work 2 is reliably gripped even if the taper angle changes.

FIG. 6 shows a state where the work holding device using the rotating body according to the first embodiment holds a large work 2 having a taper. This can be done by changing the moving stroke of the movable portion 22 of the chuck 20.

In the cases according to these embodiments, the work 2 is pressed by the work stopper 10 with a large force by the pressure of the relatively small claw portion due to the so-called "wedge" action, and is firmly gripped. Therefore, even if the arm of the robot is swung at high speed, the positional deviation is prevented.

7 and 8 show a work holding device using a rotating body according to a second embodiment of the present invention. This is a spring 50
The work stopper 10 has a displaceable structure. With this structure, when gripping the workpieces 2 having different heights, it is possible to grip without changing the length of the claw portion 6.

FIG. 9 shows a third embodiment of the present invention. This uses a spherical body for the rotating body 8 at the tip of the claw portion 6. In this case, since the point of contact with the work 2 becomes a point, the degree of freedom in the shape of the work 2 becomes greater than in the case of the first embodiment.

In the case of the present embodiment, the chuck drive system is shown as an air drive system, but it goes without saying that a cam drive system and an oil drive system are also possible.

According to the present invention, since the gripping force of the claw portion can be reduced, a large force is not applied to the rotating body and wear of the contact portion is reduced. Further, since the contact portion of the rotating body with respect to the work changes, the rotating body is evenly worn and the work is less likely to be damaged. Further, since the work is always gripped by the rotating body at the center of the receiving surface, the positioning performance can be improved.

[Brief description of the drawings]

FIG. 1 is a plan view of a first embodiment of a work holding device using a rotating body according to the present invention, FIG. 2 is a side view of a first embodiment of a work holding device using a rotating body according to the present invention, and FIG. FIG. 4 is a side view showing a work gripping device using a rotating body according to the first embodiment gripping a work.
Detailed sectional view of the chuck used in the examples, fifth
FIG. 6 is a side view of a work gripping device using a rotating body according to the first embodiment gripping a work having a taper;
FIG. 7 is a side view in which a work holding device using a rotating body according to the first embodiment holds a large work having a taper, and FIG. 7 is a step-like work holding device using a rotating body according to the second embodiment. Side view of holding the workpiece of No. 8
FIG. 9 is a side view of a work holding device using a rotating body according to the second embodiment holding a work having a high step, and FIG. 9 is a side view of a third embodiment of the present invention. 2 …… Workpiece 6 …… Claw 8 …… Rotating body 10 …… Workpiece stopper 20 …… Chuck 22 …… Movable part of chuck

Claims (1)

(57) [Claims] 1. A work stopper that supports a work from one side by a receiving surface, a plurality of claw portions that move from the periphery of the receiving surface toward the center when gripping the work, and are attached to the tip of the claw portion. And a rotating body that can move along the receiving surface or substantially parallel to the receiving surface and that supports the work from the opposite side of the receiving surface at the work gripping position. A work holding device using a rotating body, which rolls on the receiving surface or the work surface before reaching a work holding position.