JPH0239757Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a hand for a working robot, and more particularly to an operating mechanism for performing very fine work with the fingers of the hand.

Generally, when a robot hand grips a workpiece and works on it, it has a fixed finger and a movable finger, and the movable finger is moved toward or away from the fixed finger by an actuator of the drive source. There is. The operating system from the actuator to the movable finger is provided with a mechanism for reducing the stroke.

[Conventional technology]

Therefore, conventionally, a motor is used as the actuator of the movable finger of the hand, and a reduction gear with a large reduction ratio is used as the stroke reduction mechanism. This reduces the large displacement of the motor using a speed reducer to move the movable finger with a predetermined stroke, and has the advantage that the magnification can be easily set using the speed reduction ratio.

[Problem that the invention attempts to solve]

However, with the above configuration, it is difficult to miniaturize the motor and reducer, and the size of the hand itself increases, making it unsuitable for miniaturizing the entire hand to perform detailed work. Also,
Since the gear mechanism of the speed reducer has backlash, there are problems such as difficulty in accurate positioning.

[Means for solving problems]

In view of the above-mentioned problems of the conventional technology, the present invention aims to provide a hand that can miniaturize the entire hand including the operating system to perform detailed work, and also minimizes the backlash of the speed reduction mechanism. purpose.

This means uses a piezoelectric element that expands and contracts by minute displacement in response to an electric signal as an actuator, and connects the actuator to a movable finger via a multi-stage lever expansion mechanism using a plate spring or the like as a fulcrum, thereby expanding the movable finger. The device is characterized in that it is configured to swing with a predetermined stroke.

[Effect]

Based on the configuration of the hand described above, the expansion and contraction of minute displacements of the piezoelectric element actuator are expanded by lever operations in multiple stages to move the movable finger in a predetermined stroke, and the actuator and expansion mechanism are located near the movable finger of the hand body. It can be assembled in a narrow space and can be made compact, and by using a leaf spring or the like as the fulcrum of the multi-stage lever, it has very little play.

〔Example〕

Hereinafter, one embodiment of the present invention will be specifically described based on the drawings.

Referring to FIGS. 1a and 1b, an embodiment of a hand using a differential two-stage lever will be described mainly with reference to the schematic diagram of FIG. 1b. Code 1 is the hand body,
A fixed finger 2 is integrally fixed thereto, and the hand body 1 has an L-shaped bent shape as a whole, and has a step-like recess 3 cut out inside the horizontal part of the hand body 1. Two piezoelectric actuators 4 and 5 are installed in parallel inside this recess 3 with their ends fixed to the hand body 1, and these piezoelectric actuators 4 and 5 are moved in the axial direction by electric signals. Extends and contracts with minute displacement. Further, a movable finger 6 is arranged close to the fixed finger 2, and the movable finger 6 and the actuators 4, 5 are connected to a differential two-stage lever expansion mechanism 7.
Continuously configured through.

In the enlarging mechanism 7, a first lever 8 and a second lever 9 are installed vertically from inside the recess 3 of the hand body 1 above the movable finger 6. Here, the lever 8 is supported by the hand main body 1 in a scale-like manner by a leaf spring 10 in the middle, its upper end is connected to the actuator 4 by a leaf spring 11, and its lower end is connected to the upper end of the movable finger 6 by a leaf spring 12. be. Also, the lever 9 has a leaf spring 13 at the upper end.
It is supported by the hand main body 1 in a cantilevered manner, and the middle thereof is similarly connected to the actuator 5 by a leaf spring 14, and the lower end is connected to the middle of the movable finger 6 by a leaf spring 15.

Next, the operation of the hand configured in this way will be explained. First, when the piezoelectric element actuator 4 extends, the lever 8 expands and swings in the opposite direction using the leaf spring 10 as a fulcrum, so that the movable finger 6 swings using the leaf spring 15 as a fulcrum so that its tip approaches the fixed finger 2. do. Furthermore, when the other piezoelectric element actuator 5 extends, the lever 9 expands and swings toward the fixed finger 2 using the leaf spring 13 as a fulcrum, and the position of the leaf spring 15, which is the fulcrum, moves toward the fixed finger 2. in,
The movable finger 6 moves closer to the fixed finger 2. On the other hand, when the piezoelectric actuators 4 and 5 contract, the movable finger 6 retreats from the fixed finger 2 in the opposite manner to the above.

In this way, when the actuators 4 and 5 expand and contract by minute displacement, the movable finger 6 swings by expanding a predetermined stroke using one end as a fulcrum by the action of the differential type two-stage lever of the expanding mechanism 7. It becomes possible to grasp and work on small workpieces with the fingers 6 and fixed fingers 2. In this case, for example, the maximum expansion and contraction of the actuators 4 and 5 by about 10 to 20 μm can be magnified by 50 to 200 times, and a stroke of about 1 to 2 mm can be obtained.

Referring to FIGS. 2a and 2b, the principle of another embodiment of the present invention will be explained. 1 uses a differential type two-stage lever similar to the embodiment shown in FIG. It is being

b uses a two-stage lever, in which actuators 4 and 5 connect two movable fingers 6 via levers 8 and 9.
a, 6b, respectively, and two movable fingers 6
Work is performed by swinging both a and 6b. In this embodiment, the fulcrum is the hinge 16, but a leaf spring can also be used.
The actuator and lever may be arranged together on one side as in the illustrated embodiment.

[Effect of idea]

As is clear from the above description, according to the hand of the present invention, a piezoelectric element is used as an actuator,
It is an enlargement mechanism using multiple stages of levers, and these are assembled above the movable fingers inside the hand body, so the entire hand can be miniaturized and it is possible to perform extremely detailed work. By using an elastic body such as the leaf spring in the embodiment shown in FIG. 1 as the fulcrum of the lever, looseness can be reduced. The structure is simple, and the magnification can be set arbitrarily depending on the dimensions of each part.

[Brief explanation of drawings]

1A and 1B are a perspective view and a schematic diagram showing an embodiment of the hand according to the present invention, and FIGS. 2A and 2B are schematic diagrams showing another embodiment of the present invention. In the figure, 1 is the hand body, 4 and 5 are piezoelectric actuators, 6, 6a, and 6b are movable fingers, 7 is an enlargement mechanism, 8 and 9 are levers, 10 to 15 are leaf springs, and 16
indicate a hinge, respectively.

Claims (1)

[Scope of utility model registration request] A piezoelectric element that expands and contracts by minute displacement in response to an electric signal is used as an actuator, and the actuator is connected to a movable finger via an enlargement mechanism using multiple stages of levers, so that the movable finger is swung with an enlarged predetermined stroke. A hand characterized by being configured.