JPH0737325Y2 - Piezoelectric actuator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a piezoelectric actuator, and more particularly to a piezoelectric actuator having a laminated piezoelectric element utilizing a piezoelectric longitudinal effect.

[Conventional technology]

Conventionally, a piezoelectric actuator has been used as a drive source for a displacement magnifying mechanism, etc., and its basic structure is to generate a strain by applying a voltage across the laminated piezoelectric element (piezoelectric vertical effect)
Is.

FIGS. 3 (a) to 3 (c) are a configuration diagram of a piezoelectric actuator and a plan view and a front view of a state in which two actuators are combined, for explaining an example of the conventional art.

As shown in FIG. 3 (a), a laminated piezoelectric (piezoelectric) actuator 20 utilizing the conventional piezoelectric vertical effect is a piezoelectric element 22.
A plurality of internal electrodes 27 are formed inside the
A voltage whose sign is inverted is applied to 27 every other layer via the external electrode members 23A and 23B. That is, since the electric field E as shown in the drawing is applied to each layer composed of the piezoelectric element 22 sandwiched between the pair of adjacent internal electrodes 27, each layer causes extensional displacement due to the piezoelectric longitudinal effect. Therefore,
The extension of each layer is added, and the piezoelectric actuator 20 becomes S
Generates directional displacement.

Next, as shown in FIG. 3 (b), the piezoelectric actuator
The structure of the application electrode terminal for 20 is such that two piezoelectric actuators 20 having a piezoelectric element 22 and external electrodes 23A and 23B for stabilizing the displacement amount are electrically conductive via a metal plate 24 to which the electrode terminal 25 is connected. It is formed by pressure-bonding with a flexible adhesive.

[Problems to be solved by the device]

In the conventional piezoelectric actuator described above, it is difficult to realize linearity (parallelism) in the mechanism when two piezoelectric actuators 20 and the metal plate 24 are connected as shown in FIG. 3 (c). And especially the piezoelectric actuator having such a structure
When 20 is incorporated into an external mechanism such as a displacement magnifying mechanism,
There is a drawback that the piezoelectric actuator itself is destroyed because of the shape in which flexural stress is easily generated.

An object of the present invention is to provide a highly reliable piezoelectric actuator that is not destroyed by such flexural stress.

[Means for Solving the Problems]

The piezoelectric actuator of the present invention is provided with an end surface portion and a side surface of the laminated piezoelectric element for electrical connection between the laminated piezoelectric element utilizing a piezoelectric longitudinal effect and internal electrodes led to both side surfaces of the laminated piezoelectric element. A pair of external electrode members formed in an L shape or an inverted L shape along a portion, and for driving the laminated piezoelectric element, which is attached to an end surface portion of one external electrode member of the pair of external electrode members. A metal plate provided with an electrode terminal for supplying an applied voltage, and an insulating material bonded to a surface opposite to the surface of the metal plate attached to an end surface portion of the one external electrode member. Composed.

〔Example〕

Next, an embodiment of the present invention will be described with reference to the drawings.

1 (a) and 1 (b) are respectively a plan view and a front view of a piezoelectric actuator showing an embodiment of the present invention.

As shown in FIGS. 1A and 1B, in the piezoelectric actuator 1 of this embodiment, the laminated piezoelectric element 2 that takes advantage of the piezoelectric longitudinal effect is similar to the piezoelectric element 22 shown in FIG. 3A of the conventional example. It has the configuration of. One end of the piezoelectric element 2 is connected to one end of a metal plate 4 to which an electrode terminal 5 is attached via an external electrode member 3B of the piezoelectric element 2, and the other end of the metal plate 4 is connected to an insulating member 6 Are connected. This insulating member 6
Is a member for insulating the metal plate 4 when the piezoelectric actuator 1 is attached to a metal member such as a displacement magnifying mechanism.
The external electrode 3A is coupled to the other end of the piezoelectric element 2, which is similar to the conventional piezoelectric element.

Here, by thinning the metal plate 4 and the insulating member 6 described above, the piezoelectric actuator 1 having a structure in which these are connected to the laminated piezoelectric element 2 can accurately realize mechanical linearity.

FIG. 2 is a front view of a displacement magnifying mechanism using the piezoelectric actuator shown in FIGS. 1 (a) and 1 (b).

As shown in FIG. 2, even when the actuator 1 of the present invention is incorporated into a base 7 made of a metal material of a displacement magnifying mechanism and used as a displacement generation source, the mechanical linearity of the piezoelectric element 2 is high, No bending stress (perpendicular to the plane of the paper) is generated, factors such as destruction of the piezoelectric actuator 2 can be eliminated, and the reliability of the piezoelectric actuator 2 and thus the displacement magnifying mechanism can be improved. That is, the levers 8A, 8 coupled to the base 7 forming the displacement magnifying mechanism
It is possible to accurately drive B, the hinges 9A and 9B connected to these levers 8A and 8B, and the tip lever 10 to which the wire 11 is attached.

[Effect of device]

As described above, since the piezoelectric actuator of the present invention can accurately form the linearity on the mechanism, it is possible to improve the reliability when used by connecting to an external mechanism such as a displacement magnifying mechanism. is there.

[Brief description of drawings]

1 (a) and 1 (b) are plan and front views of a piezoelectric actuator showing an embodiment of the present invention, and FIG. 2 uses the piezoelectric actuator shown in FIGS. 1 (a) and 1 (b). A front view of the displacement magnifying mechanism, and FIGS. 3A to 3C are a configuration diagram of a piezoelectric actuator and a plan view and a front view of a state in which two actuators are combined, respectively, for explaining an example of the related art. 1 ... Piezoelectric actuator, 2 ... Multilayer piezoelectric element, 3A, 3B ...
External electrode, 4 ... Metal plate, 5 ... Electrode terminal, 6 ... Insulating member,
7 ... Base, 8A, 8B ... Lever, 9A, 9B ... Hinge, 10 ... Tip lever, 11 ... Wire.

Claims (1)

[Scope of utility model registration request] 1. A laminated piezoelectric element utilizing a piezoelectric longitudinal effect and an end surface portion and a side surface portion of the laminated piezoelectric element for electrical connection with internal electrodes led to both side surface portions of the laminated piezoelectric element. A pair of external electrode members formed in an L-shape or an inverted L-shape, and a voltage applied to the end surface portion of one of the pair of external electrode members for driving the laminated piezoelectric element. A metal plate provided with an electrode terminal for supplying a voltage, and an insulating material bonded to a surface opposite to a surface of the metal plate attached to an end surface portion of the one external electrode member, Piezoelectric actuator.