JPS6156074B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an article gripping device such as a robot used for processing, assembling, etc. of articles, and in particular, an object of the present invention is to improve the accuracy of the gripping position of the article. The conventional hand has a flow path 100 for communicating pressure fluid and two cylinders 10, as shown in the configuration described in Japanese Utility Model Publication No. 56-46949 (Fig. 1).
1, 102; two pistons 104, 105 that are slidably fitted into the cylinders 101, 102 and are pressed left and right, respectively, by the pressure fluid;
5, the claw 106 rotates around two parallel fulcrum shafts fixed to the main body 103;
There is a configuration having 107. and nail 10
Two pistons 104 and 105 with the same diameter on the left and right are operated at different distances from the fulcrum axis of 6 and 107, and the workpiece is held between the claw members that come into contact with the pistons, and the centering with the workpiece is fixed. An adjustment screw 108 attached to the member is brought into contact with the pawl member on one side. In this configuration, cylinders 101, 102
Because of the positional difference, the operating torque of one claw 106 is larger than that of the other claw 107, which has the advantage of determining the gripping position on the claw 106 side and improving the positioning accuracy of the workpiece. Therefore, if the dimensions of the workpiece differ, the gripping surfaces will not be parallel, resulting in an unstable gripping state, and in the case of an extremely small workpiece, it may become impossible to grip it.

On the other hand, for example, there is a structure described in Japanese Utility Model Publication No. 49-37907, which grips a workpiece by moving a pair of claws in parallel, but this method involves attaching the claws directly to the rods of two cylinders. As a result, it is difficult to maintain the parallelism of the claws due to deformation of the rod, and the structure requires two separate cylinders, making it difficult to use as an actual gripping device.

The present invention provides a novel gripping device that is an improvement on the conventional article gripping device, and one embodiment thereof will be described below with reference to the accompanying drawings.

In the figure, 1 is a hand body, which communicates with a channel 2 through which pressure fluid flows, and which communicates with this channel 2.
Cylinders 3 and 4 are formed so that their central axes are substantially the same and are wired to face each other. The inner diameter of the cylinder 3 is larger than that of the cylinder 4, and pistons 5 and 6 are slidably disposed within each cylinder 3 and 4. Reference numerals 7 and 8 denote claw holders formed in a substantially U-shape, and first members 7a and 7a are arranged substantially parallel to each other.
8a, second members 7b, 8b, and third members 7c, 8c that are substantially perpendicular to each of the first and second members and connected to one end of the same side of both members. Reference numerals 9 and 10 are guides whose both ends are held in the hand main body 1 so as to be positioned parallel to each other, and the first members 7a and 8a and the second members of the claw holders 7 and 8 are connected to each other.
The claw holders 7, 8 pass through the members 7b, 8b.
is held slidably along guides 9 and 10. The claw holders 7 and 8 are arranged between the first and second members 7a and 7b of the claw holder 7.
The first member 8a is located, and each third member 7c, 8c
are arranged to face each other with guides 9 and 10 in between. 11 and 12 are claws attached to the claw holders 8 and 7, and 13 is a spring that locks each end to the claw holders 7 and 8 and biases both claw holders 7 and 8 toward each other. . Reference numerals 7d and 8d denote protrusions formed integrally with the pawl holders 7 and 8, and the pistons 5 and 6 abut against these protrusions to operate the pawl holders 7 and 8.

A stopper 14 is provided on the hand body 1 to restrict the movement of the claw holder 7, and is configured to finely adjust the stopping position of the claw holder 7. 15
is a light-shielding plate provided on the protruding portion 8d of the claw holder 8, which is configured to shield the photocoupler 16 provided on the hand body 1 from light, thereby detecting a state in which the object is poorly gripped. Reference numeral 16 denotes suction holes provided in the claws 11 and 12 for suctioning small articles.

In the above configuration, when pressure fluid acts on the flow path 2 of the hand body 1 and the pistons 5 and 6 move in opposite directions, the claw holders 7 and 8 are moved in the same direction as each piston 5 and 6 by the pistons 5 and 6. move in the direction
The claws 11 and 12 fixed to the claw holders 7 and 8 come close to each other and can grip the article. On this occasion,
The piston 5 that operates the claw holder 7 is the piston 6
Since it has a larger pressure-receiving area, the operating force is larger than that of the piston 6, and since the stopper 14 of the claw holder 7 is provided on the claw holder 7 side, the position of the claw 11 is ensured when gripping an article. is determined, and the positions of the other claws 12 are determined based on this position. Therefore, since the gripping position of the article is determined centrally, the positional accuracy is improved. Furthermore, in the case of this embodiment, since the claws grip the article by parallel movement, stable gripping can be achieved without any change in the gripping state even if the size of the article changes. Furthermore, in this example,
In addition to the actuator consisting of pistons 5, 6 and cylinders 3, 4, in order to stabilize the movement of the claws 11, 12, the claw holders 7, 8 are guided by guides 9, 10 to adjust the posture of the claws during gripping. It is configured so that the grip does not change, and it is possible to give the claws a strong gripping force.

As described above, according to the present invention, it is possible to provide a device with improved gripping accuracy and gripping stability compared to conventional article gripping devices, and its industrial value is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional example, and FIG. 2 is a cutaway perspective view of essential parts of an article gripping device according to an embodiment of the present invention.
FIG. 3 is a sectional view of the device. DESCRIPTION OF SYMBOLS 1... Hand body, 2... Channel, 3, 4... Cylinder, 5, 6... Piston, 7, 8... Claw holding part, 7d, 8d... Piston contact part, 9, 10...
...Guide, 11, 12...Claw portion, 13...Spring, 14...Stopper.

Claims (1)

[Scope of Claims] 1. A pair of claws, a pair of claw holders that hold the claws and extend in a direction substantially perpendicular to the direction in which the claws protrude; A guide that penetrates in the same direction as the extension direction of the claw holder and slidably guides the claw holder, a hand body that holds both ends of this guide, and a hand body that holds both ends of the guide; two cylinders formed in the same direction as the axial direction; two pistons fitted in the cylinders and actuated in different directions by pressure fluid;
A flow path formed in the hand body and guiding the pressure fluid to the two cylinders, and a spring attached between the two claw holders and biasing the two claw holders in a direction toward each other. , each of the claw holders is formed with a piston contact portion corresponding to each piston sliding in the two cylinders, with which the piston comes into contact to move the claw holder; The sliding piston has different pressure receiving areas, and the claw holding part corresponding to the side having a larger pressure receiving area is prevented from moving in the same direction as the moving direction of the piston. An article gripping device characterized by being provided with a stopper. 2. The article gripping device according to claim 1, wherein the stopper is adjustable in position.