JPS6380584A - Piezoelectric actuator - Google Patents

Abstract

PURPOSE:To obtain the large amplitude of a piezoelectric actuator in a high efficiency by providing actuating pieces at both ends of a piezoelectric element, and differentially enlarging the displacements of the pieces at both ends of the element by a differentially enlarging mechanism coupled with both the pieces to produce them to an output piece. CONSTITUTION:A piezoelectric actuator has a piezoelectric element 1, a base 2, two bendable actuating pieces 3, 4 supported at the base ends to the base 2 substantially perpendicularly cross with the longitudinal direction at both longitudinal ends of the element 1, and a differentially enlarging mechanism 6 for differentially enlarging the displacements of the ends 3a, 4a of the pieces 3, 4 to operate an output piece 5. Since the displacements are produced from both ends of the element 1 in this manner, energy loss due to the restriction of the ends of the conventional element 1 is eliminated to provide a high efficiency. Further, since the displacements of both the ends of the element 1 are differentially produced to actuate the piece 5, a large amplitude is obtained at the piece 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a piezoelectric actuator using a piezoelectric element.

[Background technology]

Conventionally, as this type of piezoelectric actuator, there is one shown in FIG. In this method, one end of a laminated piezoelectric element 31 is fixed to a base 32 with an adhesive 1 or the like, and the displacement of the other end is expanded using a lever principle, and then taken out from the tip 33a of the output piece 33.

However, in this configuration, since one side of the piezoelectric element 310 is fixed, the displacement energy of the piezoelectric element 31 is lost at this fixed part. Therefore, there were problems in that efficiency was poor and it was difficult to obtain a large amplitude.

[Purpose of the invention]

An object of the present invention is to provide a piezoelectric actuator that can obtain a large amplitude with high efficiency.

[Disclosure of the invention]

The piezoelectric actuator of the present invention includes a piezoelectric element, a base, and two bendable actuators provided at both longitudinal ends of the piezoelectric element substantially orthogonally to the longitudinal direction and whose base ends are supported by the base. The apparatus includes an actuating piece and a differential magnification mechanism that differentially magnifies displacements of the ends of the actuating pieces in mutually different directions to operate the output piece.

According to the configuration of the present invention, the actuating pieces are provided at both ends of the piezoelectric element, and the displacement of the actuating pieces at both ends of the piezoelectric element is operatively magnified by the differential magnification mechanism connected to both the actuating pieces, and the displacement is outputted to the output piece. As a result, there is no energy loss at the ends of the piezoelectric element, resulting in high efficiency, and since the piezoelectric element is expanded operationally, a large amplitude can be obtained.

Embodiment An embodiment of the present invention will be explained based on FIG. This piezoelectric actuator consists of a piezoelectric element 1, a base 2, and two flexible actuators that are provided at both ends of the piezoelectric element 1 in a longitudinal direction, substantially perpendicular to the longitudinal direction, and whose base ends are supported by the base 2. It is equipped with an actuating piece 3.4 and a differential magnification mechanism 6 that differentially magnifies displacements in mutually different directions of the tips 3a and 4a of both actuating pieces 3.4 to operate the output piece 5. .

The piezoelectric element 1 is of a laminated type, and the lamination direction is the longitudinal direction. The differential magnification mechanism 6 has a tip 4a of one actuating piece 4.
It consists of an output piece 5 that extends integrally from the output piece 5 via a bent portion 7, and a connecting piece 8 that connects the tip 3a of the other actuating piece 3 to the vicinity of the base end of the output piece 5.

The bending portion 7 has a bendable hinge structure. Connecting piece 8
The operating pieces 3 and 4, which are also connected at both ends with a hinge structure, are made of elastically flexible metal plates and are fixedly connected to the base 2. Note that the actuating piece 3.4 may be hinged to the base 2, and the actuating piece 3.4 itself may not bend.

When a voltage of a predetermined polarity is applied to the operating piezoelectric element 1, the piezoelectric element 1 is extended and displaced as shown by arrows A, B, and the actuating piece 3.4 is tilted by the piezoelectric element 1 with the base 2 as a fulcrum. , due to the lever principle, the tips 3a and 4a are arrow A2.8
It is enlarged and displaced as shown in 2. At this time, the bent portion 7 at the base end of the output piece 5 is displaced by the displacement of one of the actuation pieces 4, and the displacement of the other actuation piece 3 is transmitted to the output piece 5 via the connection piece 8. Therefore, the displacement of the arrows A2 and B2 is differentially transmitted to the output piece 5, and the output piece 5 is expanded and displaced in the direction of the arrow C using the bent portion 7 as a fulcrum.

In this way, since the displacement is taken out from both ends of the piezoelectric element 1, there is no energy loss due to end restraint of the piezoelectric element 1 as in the conventional case, and high efficiency is achieved.

Furthermore, since the operation magnifying mechanism 6 differentially extracts the displacement at both ends of the piezoelectric element 1 to operate the output piece 5, a large amplitude can be obtained in the output piece 5.

In the above embodiment, the piezoelectric element 1 is of a laminated type, but it may be a single type, and one bent part 7 is provided between the actuating piece 4 and the output piece 5. The differential magnifying mechanism 6 is not limited to this, but may be any type of mechanism as long as it operates the output piece 5 by operatively magnifying the displacements of the tips of the re-operating pieces 3.4 in mutually different directions. It may be a configuration.

〔Effect of the invention〕

In the piezoelectric actuator of the present invention, actuating pieces are provided at both ends of a piezoelectric element, and a differential magnification mechanism connected to both actuating pieces operatively magnifies the displacement of the actuating pieces at both ends of the piezoelectric element and outputs it to an output piece. This has the effect that there is no energy loss at the ends of the piezoelectric element, resulting in high efficiency, and that a large amplitude can be obtained since the piezoelectric element is expanded operationally.

[Brief explanation of the drawing]

FIG. 1 is a front view of an embodiment of the present invention, and FIG. 2 is a front view of a conventional example. DESCRIPTION OF SYMBOLS 1... Piezoelectric element, 2... Base, 3, 4... Operating piece, 5... Output piece, 6... Differential expansion mechanism, 8... Connecting piece Patent applicant Matsushita Electric Works Fusu Co., Ltd.; Diagram 2: Proceeding Officer Hosho) (Voluntary) 1.1? Ushi no Komisu R 1985 Patent Application No. 225224 2, Title of the invention Piezoelectric actuator 3, Person making the amendment Relationship to the case Applicant 4, Agent 5, Date of amendment order 1 Voluntary amendment

Claims (1)

[Claims] a piezoelectric element, a base, two bendable actuation pieces that are provided at both ends of the piezoelectric element in a longitudinal direction substantially orthogonal to the longitudinal direction and whose base ends are supported by the base; A piezoelectric actuator equipped with a differential magnification mechanism that operates an output piece by differentially magnifying displacements in mutually different directions at the tips of the pieces.