JPH04159092A - gripping device - Google Patents

Abstract

PURPOSE:To provide a high grasping force by coupling an output shaft directly to a grasping claw. CONSTITUTION:When the feed of fluid to a driving source is simultaneously switched to move forward or backward an output shaft, grasping claws 2a-2c coupled directly on an output shaft are caused to approach each other radially from a grasping center or part from each other. The grasping claws 2a-2c are coupled through link mechanisms 3a-3c, and synchronously unfolded and folded. Auxiliary claws 6 are operated in a manner similar to operation of the grasping claws 2a-2c and when the auxiliary claw is brought into contact with a substance 9 to be grasped, it is rotated around a rocking shaft and is positioned in parallel to a grasping axis. When the substance 9 to be grasped is absent, the auxiliary claw 6 is inclined based on the grasping axis. Thus, reliable detection can be executed in a way that the one end of the auxiliary claw 6 approaches and parts away from a detector 8, located in the one spot of the grasping claws 2a-2b, according to the presence of the substance 9 to be grasped.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a gripping device that is attached to an industrial robot or the like for transferring several types of cylindrical or cylindrical workpieces having different diameters.

[Conventional technology]

This type of conventional device is disclosed in Utility Model Publication No. 15101/1986.
As described in , a single drive source operates one of the plurality of gripping claws, and this operation is transmitted to the other plurality of gripping claws by a link mechanism, so that the gripping claws are opened and closed. It was like that. In addition, in order to confirm the object to be grasped, a detector was installed in the gripping claw to directly detect the object to be grasped, or a method was used in which a simple method was used to detect pressure changes inside the fluid cylinder of the drive source. .

[Problem to be solved by the invention]

The purpose of the above conventional technology is to grip a lightweight workpiece such as a printed circuit board, and in order to grip a heavy workpiece, the link mechanism for transmitting the force of the driving source requires mechanical rigidity. It has the disadvantage of becoming larger overall. In addition, regarding the detection of a grasped object, when directly detecting the grasped object with a detector, it may not be possible to detect the object due to the shape of the part where the grasped object and the grasping claw come into contact, and pressure changes inside the fluid cylinder may not be detected. The detection method has the disadvantage that a signal corresponding to an abnormal position, for example, when the gripping claws are mechanically restrained before the gripping of the workpiece is completed, is output.

An object of the present invention is to solve the above-mentioned drawbacks and to provide a gripping position that is compact and generates a strong gripping force.

[Means to solve the problem]

In order to achieve the above object, the same number of driving sources as the gripping claws are provided radially from the gripping center, and the output shafts of the driving sources are directly connected to each of the gripping claws to generate a gripping force directly to the gripping claws. I did it like that. Furthermore, each of the gripping claws was connected via a link mechanism in order to synchronize the opening and closing operations of the gripping claws.

Furthermore, in order to confirm the gripping state, an auxiliary claw that comes into contact with the object to be grasped is provided at the tip of the gripping claw, and a detector for detecting one end of the auxiliary claw is installed at one location of the grasping claw. Established.

[Effect]

When fluid supply to each drive source is simultaneously switched and the output shaft is advanced or retreated, the gripping claws directly connected to the output shaft approach or separate from each other radially from the gripping center. Each of the gripping claws is connected via a link mechanism and opens and closes synchronously.

The auxiliary claws operate in the same manner as the gripping claws described above, and when they come into contact with the object to be gripped, they rotate about the swing axis and become parallel to the gripping axis. Further, when there is no object to be gripped, the auxiliary claws are inclined with respect to the gripping axis. Therefore, one end of the auxiliary claw approaches or separates from the detector provided at one location of the gripping claw, depending on the presence or absence of the object to be gripped, allowing reliable detection.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1, 2, and 3.

1 is a disc-shaped base that is attached to the tip of the wrist of an industrial robot or the like. Air cylinders 5.5a to 5C are attached to the lower surface of the base 1 so that the pistons 7 operate radially from the center of the base 1 on a plane parallel to the lower surface of the base 1. The gripping claws 2, 2a to 2C are the piston 7
is fixed at one end. A disc-shaped rotary plate 4 that is rotatable about the center of the base 1 is attached to the upper surface of the base 1. On the bottom surface of the rotary plate 4, each link 3°3a~
One end of 3c is rotatably connected at every other corner,
The other end of each link 3.3a~3'c is each gripping claw 2, 2a~
0 gripping claw 2 rotatably connected to the center of the upper surface of 2c
, 2a to 2C are attached with auxiliary claws 6 that are swingable about an axis perpendicular to the operating direction of the gripping claws 2, 2a to 2C.

A detector 8 is provided on one of the gripping claws 2, 2a to 2C.

When the air supply to each air cylinder 5, 5a to 5C is simultaneously switched and the piston 7 is advanced or retreated, each gripping claw 2, 2a to 2
C move toward or away from each other radially from the center of the base 1. At this time, each gripping claw 2.2a to 2c is attached to each link 3.
．． 3a to 3c and are connected to each other via the rotary plate 4, so that they open and close in synchronization. Therefore, even if the inner diameter of the object to be gripped 9 changes, the amount of movement of each of the gripping claws 2, 2a to 2C is the same, and the object can be gripped at a constant center with high accuracy. As shown in FIG.
If there is no object 9, the grip is tilted, and as shown in FIG. 2, if there is an object 9, it comes into contact with the inner surface of the object and becomes parallel to the gripping axis. Therefore, one end of the auxiliary claw 6 approaches the grasping claw 2 when there is an object 9 to be grasped, and moves away from the grasping claw 2 when there is no object 9 to be grasped. Since the detector 8 is installed so as to output an electric signal only when the auxiliary claw 6 approaches, the presence or absence of the object 9 to be held can be confirmed. Note that FIGS. 4 and 5 show another embodiment in which the outer periphery of a cylindrical workpiece is gripped.

As explained above, in this embodiment, since the output of the air cylinder, which is the driving source, is directly generated in the gripping claws, there is no loss due to transmission, and a large gripping force can be obtained. Furthermore, the structure is simple and can be made small and lightweight.

〔Effect of the invention〕

According to the present invention, since the output of the drive source is directly transmitted to the gripping claws, it is possible to obtain a large gripping force, thereby making it possible to reduce the size and weight of the gripping device. Moreover, by providing the auxiliary claws, the gripping can be stabilized, thereby preventing false detection of the presence or absence of a workpiece, reducing malfunctions of the entire system, and improving the operating rate.

[Brief explanation of drawings]

Fig. 1 is a plan view of one embodiment of the present invention, Fig. 2 is a front view of Fig. 1, Fig. 3 is an explanatory diagram of the operation of the auxiliary claw portion of the same embodiment, Figs. It is an explanatory view of the operation of the auxiliary claw of the embodiment. 1...Base, 2,2a-2c...Gripping claw, 3,3
a~3C...link, 4...rotating plate, 5,5a~5
c...Air cylinder, 6...Auxiliary claw, 7...Piston, 8...Detector, 9...Gripped object No. 1 Fig. 2c 6c2b Fig. 3 Fig. 5

Claims (1)

[Scope of Claims] 1. A gripping device comprising a plurality of gripping claws, a link mechanism that connects the gripping claws so that they can be opened and closed synchronously, and a drive unit that opens and closes the gripping claws. The gripping device according to the invention, wherein an output shaft of each of the gripping claws is directly connected to the gripping claws so that the drive section operates radially from the gripping center of the gripping claws. 2. An auxiliary claw at the tip of the gripping claw that can swing about an axis perpendicular to the opening/closing direction of each of the gripping claws and comes into contact with the object to be grasped, and the auxiliary claw comes into contact with the object to be grasped. 2. The gripping device according to claim 1, further comprising a detector for confirming that one end of the auxiliary claw approaches or separates from the gripping claw.