JPS63120480A - Lamination type piezoelectric actuator - Google Patents

Abstract

PURPOSE:To make it possible for a single lamination type piezoelectric actuator to control a plurality of displacement ranges, by dividing a pair of external electrodes into a plurality of divisions in such a manner that the actuator can independently transfer with respect to each divided unit. CONSTITUTION:A plurality of internal electrode layers 2 are connected to a pair of external electrodes 5 for each layer so as to constitute each counter electrode. A pair of the external electrodes 4 is divided into a plurality of divisions in the manner in which an actuator can independently transfer for each split unit. For example, the actuator has a cross-sectional area of 5mmX5mm, and a length of 18mm. As for the structure, 144 layers of an internal electrode 2 are stuck with a spacing of 115mum, which are sintered as one body. The external electrode 4 is divided into three divisions of 5 layers 25 layers, and 100 layers of the internal electrode 2, and a power source 5 is connected to each external electrode 4. Thus, the division I (5 layers), the division II (25 layers) and the division III (100 layers) have the following displacement amount per volt respectively; 0.005mum, 0.025mum and 0.1mum.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an integrally sintered laminated piezoelectric actuator that converts electrical input energy into mechanical energy in the form of displacement or force by utilizing the piezoelectric longitudinal effect, and particularly relates to a monolithically sintered laminated piezoelectric actuator that utilizes the piezoelectric longitudinal effect to convert electrical input energy into mechanical energy in the form of displacement or force. The present invention relates to a laminated piezoelectric actuator having a structure having a plurality of displacement parts that can be independently displaced.

Piezoelectric actuators are being applied as actuators in a wide range of fields, including replacing electromagnetic actuators. While electromagnetic actuators are driven by current, piezoelectric actuators are driven by voltage, and piezoelectric actuators essentially consume less power. In addition, unlike electromagnetic actuators that consist of multiple parts such as coils and magnets, monolithically sintered laminated piezoelectric actuators are solid displacement elements, so they do not require assembly man-hours and are advantageous for mass production. It has advantages such as good impact resistance.

This laminated piezoelectric actuator generally uses a pair of external electrodes connected to an internal electrode as input terminals to generate a displacement amount or force according to an input voltage. In this case, if a single laminated piezoelectric actuator is used to control multiple displacements with different control ranges, a possible method would be to glue multiple laminated piezoelectric actuators in series and drive each actuator for control. However, each laminated piezoelectric actuator is required depending on the displacement control range, and it is generally difficult to adhere the actuators with high precision.

Furthermore, commonly used organic adhesives have the problem of deterioration of adhesive strength during long-term use or due to temperature changes in the environment in which they are used.

In view of this, the main purpose of the present invention is to propose an actuator of this type that can control multiple displacement ranges with a single laminated piezoelectric actuator, unlike a configuration in which multiple laminated piezoelectric actuators are bonded together. shall be.

The present invention provides a method in which a plurality of internal electrode layers are connected to an external electrode of the main body so that each layer constitutes a counter electrode, and the pair of external electrodes is capable of independently displacing the actuator in division units. As shown in the figure, it is characterized by being divided into multiple parts.

In this case, it is preferable to divide the external electrode into 1 pieces so that the number of connected internal electrodes is the same, since this reduces the piezoelectrically inactive portion.

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

FIG. 1 is a diagram showing an example of the present invention. The entire actuator has a cross section SmIIIXS mm and a length of 18vn, and has a structure in which 144 internal electrodes 2 are laminated at intervals of 115 μm and are integrally fired.

The external electrode 4 has 5 layers, 25 layers, and 100 layers of the internal electrode 2.
It is divided into three layers. 1 represents an insulating layer, and 3 represents a piezoelectric ceramic element. Note that the number of internal electrodes in FIG. 1 is omitted to simplify the drawing. A power source 5 is connected to each external electrode 4, respectively.

Table 1 shows the amount of displacement when voltages of 1 volt and 1()0 volts are applied to the laminated piezoelectric actuator constructed in this way.

From Table 1 @ Table 1, division 1 (5 layers) is 0°0 per volt.
05μ [11 displacement control possible, division 1 (25N) is 0.025μm 1 division III (100 layers) is 0.1μm
If the voltage is above μm and 100 volts, a displacement 100 times that amount can be obtained. Therefore, in the division (2), the displacement amount of several microns is measured in units of 0°1 μm, and then in the division (2), the displacement is measured at 0°.
Perform unit positioning of 0.25μ1m, then 0.025μ1m unit positioning.
Both coarse and fine movements, such as precise positioning in units of 0.005 μm, are possible.

As described above, according to the present invention, a plurality of internal electrode layers are connected to a pair of external electrodes so that each layer constitutes a counter electrode, and the external electrodes of the pair each divide the actuator into divided units. Since it is divided into multiple parts so that it can be displaced independently, it can be divided into multiple displacement ranges without causing problems such as peeling of the adhesive used when dividing the external electrode of the actuator into multiple parts. It becomes possible to provide an actuator that can control

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Insulating layer, 2... Internal electrode, 3... Piezoelectric ceramics, 4... External electrode, 5... Each power supply.

Claims (1)

[Claims] A plurality of internal electrode layers are connected to a pair of external electrodes so that each layer constitutes a counter electrode, and the pair of external electrodes is divided into a plurality of parts so that the actuator can be independently displaced in divided units. An integrally sintered laminated piezoelectric actuator characterized by: