JPH0643040B2 - Joint device - Google Patents

Description

The present invention relates to a piezoelectric element or an electrostrictive element having an inertial body attached to its tip in a moving body placed on a friction surface. A piezoelectric element or an electrostrictive element is moved by applying an electric field to it, and the kinetic energy, the inertial action of the inertial body, and the reaction force acting on the movable body are used to finely drive (move) the minute body. The present invention relates to a joint device using a generator.

[Prior Art] There has been a demand for proposal of means for performing positioning in micro or nanometer order with high accuracy, such as a sample table of a semiconductor manufacturing apparatus and a micromanipulator for biotechnology.

Conventionally, in a biotechnology micromanipulator used for cell fusion technology (operation), cell injection, by remotely operating a fine sword or injection needle while observing the microscope,
Suction, cell cutting, etc. are performed, but these drives depend on a hydraulic system or the like.

[Problems of the prior art] However, even in the current highest-level system, the resolution remains on the order of 10 microns, and the working efficiency is 50% or less for the skilled person.

It is an object of the present invention to propose a joint device having a smaller size than that of a conventional one and having a resolution increased from the order of micrometer to nanometer.

[Means for Solving the Problems] The present invention proposes the following joint device as means for achieving the above object.

A minute driving force generator utilizing the impact force generated when a voltage is applied to a piezoelectric element or an electrostrictive element with respect to an arm supported at one point so that it can be tilted in the free direction by the friction surface of the support. A joint device in which the driving direction of the minute driving force generator is eccentric with respect to the central axis of the arm and two or more are mounted.

The cross-sectional shape of the arm is arbitrary, and it is possible to select any cross-sectional shape according to the purpose. For example, it may be circular or flat.

[Operation] When a voltage is suddenly applied to the piezoelectric element (or electrostrictive element) attached to the arm, the piezoelectric element is distorted, and the piezoelectric element suddenly (impulsively) moves (extends or compresses) An inertial force is imparted to the by an inertial body. Then, when this motion is forcibly stopped suddenly, a reaction force is generated in the arm, and this reaction force exceeds the frictional force on the support portion of the arm, so that the arm moves in the direction in which inertia acts, that is, the piezoelectric force. The element tilts in the direction of movement.

In a usual case, a plurality of minute driving force generators are attached to the arm, and the actuators are controlled so as to incline or turn in an arbitrary direction by the cooperation of these generators.

[Embodiment] FIG. 1 shows a basic embodiment of the present invention, 1 is an arm having a quadrangular cross section, 2 is a joint portion of the arm 1, and 2
As shown in FIG. 1 (a), it is composed of a spherical body 3 and a concave curved surface 5 of a support body 4 which receives the spherical body 3.

Reference numeral 6 denotes a minute driving force generator attached to the arm 1. The minute driving force generator 6 is composed of a piezoelectric element 7 and an inertial body 8 and is attached to the arm 1 horizontally and at the same time. Is eccentric with respect to the central axis of and is attached to each surface (see FIG. 3).

Reference numeral 9 denotes a spring that applies a frictional force to the spherical shape 3 in the joint 2, and 10 denotes a spring receiver. The elastic force of the spring 9 can be controlled by a screw 11 to control the frictional force. Is also free. Needless to say, electromagnetic force and electrostatic force can be used to control the frictional force.

The structure of the joint portion 2 is not particularly limited, and is shown in FIG.
The spherical surface 3 may be engaged with the conical surface 5'to form a friction surface. In addition, it goes without saying that any structure may be used as long as it generates friction in the 360 ° free direction. Next, the cross section of the arm 1 may be a regular triangle as shown in FIG. 4, and the minute driving force generator 6 may be attached to each surface.

FIG. 5 shows a conventional embodiment in which a joint device is added in two stages, and the arm 1 can be bent halfway with the base as shown.

The operation of the joint device will be described.

In FIG. 3, when the (+) motion is applied to the minute driving force generator 6-A and the same (-) motion is applied to 6-C, the driving force in the arrow Y direction acts on the arm 1. Then, the arm 1 tilts in that direction.

Next, when 6-B is given a (+) motion and 6-D is given a (-) same motion, a driving force in the X direction acts on the arm 1 and the arm 1 tilts in that direction. To do.

Next, when 6-A and 6-C are each given a (+) motion, a driving force in the direction of the arrow θ acts on the arm 1 to cause the arm 1 to move.
Turns.

The above is the basic operation, and the mounting position and direction of the driving force and the minute driving force generator, the voltage, the voltage applied to the electrostrictive element, the applied voltage pattern control, and the synthetic force control have been devised to improve the arm. 1 can be controlled in any direction and turning angle.

The movement amount of the arm 1 can be controlled in the order of micrometer to nanometer depending on the voltage pattern applied to the piezoelectric (electrostrictive) element and the panel slate (the number of times the voltage is applied).

[Effects of the Present Invention] As described above, the present invention supports the arm at one point so that it can be tilted and swung freely, and eccentrically attaches the minute driving force generator to the free end side of this arm to impart a frictional force to the arm. The joint motion and the swivel motion were made possible in the 360 ° direction around the supporting part (joint part).

Therefore, when this joint device is applied to an arm of a microrobot or the like, it becomes possible to perform minute joint movement with high accuracy.

As a result, it is possible to increase the efficiency in a micromanipulator or the like.

Also, when applied to the posture control of the sample stage of a microscope or changing the direction of the optical axis with a prism or mirror, by attaching these prisms and mirrors to the arm,
The prism and mirror can be controlled with high precision.

Next, since the arm can be driven simply by attaching a minute driving force generator using a piezoelectric element (or an electrostrictive element) to the arm, the overall shape can be reduced. As a result, it is particularly effective in the fields of electronic-related devices, biotechnology fields, optical devices, etc., in which further miniaturization is required.

[Brief description of drawings]

FIG. 1 is a perspective view of a joint device embodying the present invention, FIGS. 2 (a) and 2 (b) are explanatory views of a joint portion, and FIGS. 3 and 4 are examples of a mounting position of a minute driving force generator on an arm. FIG. 5 is an explanatory view showing a state in which joint devices are added. 1 ... Arm, 2 ... Joint part 3 ... Spherical body, 4 ... Support body 5 ... Concave curved surface, 6 ... Micro drive force generating body, 7 ... Piezoelectric element, 8 ... Inertial body, 9 ... Spring 10 ... Spring holder 11 ... Screw

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Atsushi Mimatsu 635 Nakamuhara, Tsuchiura City, Ibaraki Prefecture, Prima Ham Co., Ltd. (56) , U)

Claims (1)

[Claims] 1. An impact force generated when a voltage is applied to a piezoelectric element or an electrostrictive element with respect to an arm supported at one point so that the support surface can be tilted in a free direction by a friction surface of the support. A joint device in which a minute driving force generator is attached, and the driving direction of the minute driving force generator is eccentric with respect to the central axis of the arm, and two or more are attached.