JPH0767292B2 - Actuator using piezoelectric or magnetostrictive element - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a table used as a workbench in, for example, an apparatus for producing and processing articles, an apparatus for manufacturing semiconductor elements,
The present invention relates to an actuator using a piezoelectric or magnetostrictive element used for rotationally driving by a constant angle.

Problems to be Solved by the Related Art and Invention Conventionally, this type of actuator is designed to drive the moving element in rotation by the expansion of the piezoelectric or magnetostrictive element, so that the driving direction is limited to one direction. There was a drawback that the field was narrow.

Means for Solving the Problems As means for solving the above problems, an actuator using the piezoelectric or magnetostrictive element of the present invention has a pair of friction side surfaces spaced from each other and can be rotationally driven. A pair of clamp shoes connected to the movable element supported by the elastic member are urged by the elastic force of the elastic member to close the legs, and the piezoelectric element or the magnetostrictive element is sandwiched between them to resist the urging force by the extension deformation force. Then, the tip of each clamp shoe is pressed against each friction side surface to release the clamp, and at the symmetrical position of the rotation center of the mover, the connecting portion of each clamp shoe is used as a fulcrum. As a pair, a pair of clamp mechanisms that are swingably supported on the base, a drive rod that advances by expansion deformation of a piezoelectric element or a magnetostrictive element, and a drive rod that biases the drive rod backward. A preload elastic body that applies a preload by pressing it against the element, and both the extensional deformation force of the element and the restoring elastic force of the preloading elastic body stored during extensional deformation of the element are moved. The drive mechanism for connecting the drive rod to a position near the swinging fulcrum of each clamp mechanism and swingably driving each clamp mechanism, and the drive mechanism and each clamp mechanism in advance. The control device is configured to operate in the set order.

Advantageous Effects and Effects of the Invention Since the present invention has the above-described configuration, the moving element is clamped by either one of the clamping mechanisms, and the drive rod is advanced by the extension deformation force of the element or retracted by the restoring elastic force of the preload elastic body. Then, the other clamping mechanism is used to clamp the mover and retract or advance the drive rod one after another to significantly reduce the stop time of the mover and to intermittently rotate the mover at high speed. Is possible, and by reversing the clamp timing of both clamp mechanisms,
The mover can be rotationally driven in both forward and reverse directions.

FIGS. 1 and 2 show an embodiment of the present invention. A driving body 6e applied to this embodiment is a central hole of a front plate of a cylindrical body 10a screwed into a mounting hole 9 of a base 7. , The drive rod 14b is slidably fitted, and the piezoelectric element is provided between the rear end and the bottom surface of the mounting hole 9.
A tension bolt 66 (an elastic body for preload of the present invention) provided with an arm 65 projecting from both sides of the drive rod 14b and passing between an arm 11 and the base 7
By tightening, the drive rod 14b is biased backwards and the piezoelectric element 11 is preloaded.
The drive rod 14b can drive the mover 2 both when the tension rod 66 advances while elastically extending the tension bolt 66 by the extensional deformation force of the piezoelectric element 11 and when the restoring elastic force stored in the tension bolt 66 is used. This driving body 6e is provided with friction surfaces 3 on both sides of the outer peripheral edge, is fixed to the substrate 1a at one side of the moving element 2 which is rotatably supported by the substrate 1a by the shaft 5, and is moved. A pair of clamps 60a, 60b are arranged above and below the child 2, and these clamps 60a, 60b are formed by a pair of clamp shoes 21 projecting on the base body 20 so that they can be opened and closed. A clamping portion 22 that clamps the friction surface 3 of the moving element 2 is formed, and the root portion 23 of the clamp shoe 21 is thin and serves as an elastic fulcrum. Tighten the tension bolt 24 passed between As a result, both clamp shoes 21 are closed, and a magnetostrictive rod-shaped magnetostrictive alloy made of a giant magnetostrictive alloy that expands and deforms by applying a magnetic field from outside to magnetize between the clamp shoes 21. The element 26 is inserted through the center hole of the coil 27 and mounted, and both ends thereof are abutted against the inner surface of the clamp shoe 21, and both clamp shoes 21 are always closed by the pulling force of the tension bolt 24 to cause friction of the moving element 2. When the mover 2 is clamped by sandwiching the surface 3 and the magnetostrictive element 26 is preloaded and the coil 27 is excited to form a magnetic field, the magnetostrictive element 26
Are extended and deformed to release the clamps by opening both clamp shoes 21 against the pulling force of the tension bolts 24, and the elongated holes 48 formed through the base 20 are respectively provided in the substrate 1a.
Fitting on the support shaft 47 passed between them, the support shaft 47 is swingably supported while allowing movement in the longitudinal direction, and at both ends of the connecting plate 61 attached to the tip of the drive rod 14b of the drive body 6e, A connecting rod 62 having a spherical head 63 at its tip is attached, and each spherical head 63 is fitted into the spherical hole 52 of the connecting portion 51 projecting at a position near the swing center of each clamp 60a, 60b. When the movable rod 2 is clamped by the upper clamp 60a and the drive rod 14b is advanced with the extension deformation of the piezoelectric element 11,
The mover 2 is clamped by the upper clamp 60a and oscillated, and the mover 2 is pushed. When the drive rod 14b is retracted by the restoring elastic force of the tension bolt 66, the mover 2 is clamped by the lower clamp 60b. By repeatedly pulling the moving element 2 while swinging the lower clamp 60b, the moving element 2 is rotationally driven in the clockwise direction indicated by the solid arrow, and by repeating the operation opposite to the above, The mover 2 is rotationally driven in the counterclockwise direction shown by the broken arrow, and the drive rod 14 of the drive body 6e is driven.
Since the moving element 2 is driven both when advancing and when moving backward, it is suitable for intermittent driving at high speed because the moving element 2 has a very short stop time.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of one embodiment of the present invention with one substrate removed, and FIG. 2 is a sectional view taken along line CC of FIG. 2: Moving element, 3: Friction surface, 6e: Driving body, 11: Piezoelectric element, 14b: Driving rod, 21: Clamp shoe, 24: Tensile bolt, 26: Magnetostrictive element, 47: Support shaft, 48: Long hole, 51 : Connection part, 52: Spherical hole, 60
a, 60b: Clamp, 61: Connecting plate, 62: Connecting rod, 63: Spherical head, 66: Tensile bolt (elastic body for preload)

Claims (1)

[Claims] Claim: What is claimed is: 1. A pair of frictional side faces spaced apart from each other, which are rotatably supported, and a pair of clamp shoes, which are openably and closably connected, urge a closed leg by elastic force of an elastic member. In addition, by sandwiching the piezoelectric element or the magnetostrictive element between them to open the leg against the biasing force by its extensional deformation force, a clamp by pressing the tip of each clamp shoe against each friction side surface,
The clamp is released, and at a symmetrical position of the center of rotation of the mover, a pair of clamp mechanisms that are swingably supported on the base with the connecting portion of each of the clamp shoes as a fulcrum, a piezoelectric element or a magnetostrictive element. An extensional deformation force of the element, comprising a drive rod that advances due to extensional deformation of the element, and a preload elastic body that applies a preload by pushing the drive rod backward and pressing it against the element, Both of the restoring elastic forces of the preload elastic body stored when the element is stretched and deformed can be used as the driving force of the moving element, and the driving rod is located near the swing fulcrum of each clamp mechanism. A piezoelectric actuator comprising: a drive mechanism connected to a position to drive the respective clamp mechanisms in an oscillating manner; and a control device for operating the drive mechanisms and the respective clamp mechanisms in a preset order. It actuators using a magnetostrictive element.