JPH0487671A - Twisting oscillator - Google Patents

Abstract

PURPOSE:To obtain the twisting oscillator effective as a driving means of apparatus for precision working by providing block-shaped electrostrictive elements which generate circumferential oscillation and disk-shaped or planar electrostrictive elements which generate the vibrations in a thickness direction and providing electrodes on the respective end faces of these electrostrictive elements. CONSTITUTION:This twisting oscillator consists of the block-shaped electrostrictive elements 1, the disk-shaped electrostrictive elements 2, the electrodes 3, and block bodies 5, 6 fastened by means of a bolt 4 to constitute a Langevin type oscillator. The electrostrictive elements 1 generate the twisting oscillation in the circumferential direction and are combined with plural pieces of simple substance 1a of ceramics which consist of ferroelectric crystals and are subjected to a polarization treatment in a circumferential direction, by which these elements are formed to a toric shape. The electrostrictive elements 1 are constituted by laminating plural layers of the toric elements on both sides of the electrodes 3 in order to amplify torsional force. The electrostrictive elements 2 generate longitudinal oscillation perpendicular to the twisting oscillation direction of the electrostrictive elements 1 and are formed by using the ceramics which consist of ferroelectric crystals subjected to a polarization treatment in the thickness direction (Z direction) and are formed to the toric shape.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a torsional vibrator used for powering various types of equipment, such as machine tools.

[Conventional technology]

For example, various types of processing equipment for turning, cutting, grinding, etc. on workpieces have been developed and are widely used. Further, in such machining operations, high precision is sometimes required, and there is a strong desire to develop high precision machining equipment to meet this demand.

Under these circumstances, attempts have been made to perform high-precision machining using, for example, high-frequency vibrations, ultrasonic vibrations, and the like. That is, such processing equipment has been developed, for example, using an electrostrictive element, generating longitudinal vibration, that is, vibration in the thickness direction of the electrostrictive element, and using the vibration to perform a predetermined processing operation. . However, in this type of machining equipment, since the direction of vibration motion is linear, it is not suitable for machining operations in the circumferential direction, such as hole machining.

Therefore, processing equipment using a torsional vibrator as shown in FIG. 7 has been proposed. That is, this torsional vibrator consists of a block-shaped electrostrictive element 100 (see FIG. 8) having residual polarization in the same circumferential direction and arranged in the same direction, and a metal element sandwiching the electrostrictive element 100 from both sides with bolts 101. It is composed of a material 102 and an electrode 103 connected to an electrostrictive element 100, and by applying a predetermined alternating electric field between the electrodes 103, vibration is caused in the circumferential direction.

[Problem to be solved]

Incidentally, such a torsional vibrator is effective when used as a drive means for processing equipment, as it enables hole drilling with high accuracy, but it is not suitable for use as a drive means for, for example, tapping and machining. are insufficient, and there is a demand for the development of something effective for these precision machining operations.

SUMMARY OF THE INVENTION In view of the above-mentioned circumstances, it is an object of the present invention to provide a torsional vibrator that is effective as a driving means for precision machining equipment such as tap machining and spear machining.

[Means for Solving the Problem] That is, the torsional oscillator of the present invention generates vibration in the circumferential direction by arranging a plurality of block-shaped objects having residual polarization in the circumferential direction along the circumferential direction. A block-shaped electrostrictive element that has residual polarization in the thickness direction perpendicular to the circumferential direction in which this block-shaped electrostrictive element vibrates, and a disc-shaped or plate-shaped element that generates vibration in the thickness direction. An electrostrictive device comprising an electrostrictive element, an electrode provided on each end face of these electrostrictive elements, and a block body attached to sandwich a drive unit made up of these electrostrictive elements and electrodes from both end faces, It is formed so that a predetermined electric field is applied to it to cause helical torsional vibration.

[Effect]

The torsional vibrator of the present invention simultaneously performs torsional vibration in the circumferential direction by a block-shaped electrostrictive element and longitudinal vibration in the thickness direction, that is, perpendicular to the circumferential direction, by a disc-shaped or plate-shaped electrostrictive element. It is possible to generate a spiral vibration motion in which vibrations in these two directions are vectorially combined.

〔Example〕

An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a torsional oscillator according to the present invention.
This torsional vibrator consists of a block-shaped electrostrictive element 1, a disc-shaped electrostrictive element 2, an electrode 3, and a block body 5.6 fastened with bolts 4, and constitutes a Langievan type vibrator. are doing.

In addition, the reference numeral 7 in the figure indicates an insulator provided in the bulge to prevent short circuit to the bolt 4 and the block body 5.6.

The electrostrictive element 1 causes torsional vibration in the circumferential direction, and is made of a ceramic single body 1a made of ferroelectric crystal and polarized in the circumferential direction as shown in FIG. 2, as shown in FIG. It has a structure in which a plurality of them are combined to form an annular shape. In order to amplify the torsional force, the electrostrictive element 1 of this embodiment has a structure in which two layers of annular elements are laminated with an electrode 3 sandwiched therebetween, as shown in FIG. In addition,
This electrostrictive element is not particularly limited to this two-layer laminated one, and the number of laminated layers may be adjusted as appropriate depending on the magnitude of the torsional force to be generated.

The electrostrictive element 2 causes longitudinal vibration perpendicular to the torsional vibration direction of the electrostrictive element 1, and is made of a ferroelectric crystal polarized in the thickness direction (Z direction) as shown in FIG. Ceramics formed into an annular shape are used. In the electrostrictive element 2 of this embodiment, in order to amplify the longitudinal coupling, the electrode 3 is strained in the thickness direction (Z
It has a structure in which two layers are laminated in the same direction.

The electrode 3 is sandwiched between each electrostrictive element 1.2, and an alternating electric field (E) is generated between adjacent electrostrictive elements, that is, in the thickness direction of each electrostrictive element 1.2. is configured to give

The block body 5 is tightened together with the block body 6 by bolts 4 to sandwich the electrostrictive elements 1 and 2. In this embodiment, each electrostrictive element 1 and 2 is made of a metal material with good vibration characteristics. It is formed into a cylindrical shape with the same cross-sectional shape.

The block body 6 is formed in a substantially cylindrical shape from the same metal material as the block body 5, and has a female screw 6a screwed into the bolt 4 formed in the center thereof.

Therefore, according to this embodiment, by applying a predetermined alternating electric field to each electrode 3, each electrostrictive element 1.2 is caused to vibrate in the direction shown in FIG. 4, and as a result, the block body 6, it is possible to generate a spiral motion by vectorially combining the forces in these directions as shown in FIG.

〔effect〕

As explained above, according to the torsional vibrator according to the present invention, one electrostrictive element produces circumferential motion, and the other electrostrictive element produces vertical motion perpendicular to the circumferential direction. By operating the electrostrictive elements at the same time, it is possible to generate a helical motion that is a combination of both motions, which is an effective means of movement for precision machining equipment such as screw tapping and reaming. Can be provided.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a torsional vibrator according to the present invention, and FIG.
The figure is a perspective view showing ceramics constituting a block-shaped electrostrictive element according to the present invention, FIG. 3 is a perspective view showing a block-shaped electrostrictive element formed by combining the ceramics shown in FIG. 2, and FIG. FIG. 5 is a perspective view of a main part showing an electrostrictive element according to the invention; FIG. 5 is a perspective view showing a disk-shaped electrostrictive element according to the invention; FIG. 6 is an explanatory diagram showing the operation of the torsion pendulum according to the invention; FIG. 7 is a sectional view showing a conventional torsional pendulum, and FIG. 8 is a perspective view showing an electrostrictive element of the torsional vibrator shown in FIG. DESCRIPTION OF SYMBOLS 1... (block-shaped) electrostrictive element, 2... (disc-shaped) electrostrictive element, 3... electrode, 5.6... block body.

Claims (1)

[Claims] 1. A block-shaped electrostrictive element that generates vibration in the circumferential direction, which is formed by arranging a plurality of block-shaped elements having residual polarization in the circumferential direction; A disc-shaped or plate-shaped electrostrictive element that has residual polarization in the thickness direction perpendicular to the circumferential direction in which the electrostrictive element vibrates and generates vibration in the thickness direction, and each of these electrostrictive elements It is equipped with an electrode provided on an end face, and a block body attached so as to sandwich a drive unit made of these electrostrictive elements and electrodes from both end faces, and a predetermined electric field is applied between the electrodes to create a spiral twist. A torsion oscillator characterized by being formed to cause vibration.