JP3052484B2 - Displacement enlargement mechanism of piezoelectric actuator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a displacement enlarging mechanism for a piezoelectric actuator which enlarges the displacement of an actuator comprising a laminated piezoelectric element by leverage.

[0002]

2. Description of the Related Art FIG. 5 has been proposed as the displacement enlarging mechanism. Here, (A) is a side view and (B) is a front view thereof. In the figure, 1 is a reverse gate case,
Numeral 2 denotes an actuator composed of a laminated piezoelectric element disposed inside thereof, 3 denotes a receiving plate mounted on the upper surface of the actuator 2, 4 denotes a lever, and 5 denotes a lever interposed between the lever 4 and the receiving plate 3. A pair of right and left cylindrical movable fulcrum pins, 6 is a pair of left and right flexible hinges that support the lever 4, and 7 is a displacement output piece that is mounted immediately above the flexible hinge 6 and perpendicular to the lever 4. Both ends of the flexible hinge 6 made of a leaf spring are made of a resin or an alloy having a lower melting point than the flexible hinge 6.
And the lever 4 is fixed by insert molding.

In such a configuration, when a voltage is applied to the actuator 2 from the lead wire 8, the actuator 2 undergoes an elongation displacement. This displacement is transmitted to the lever 4 via the movable fulcrum pin 5, and the lever 4 can be bent. It rotates counterclockwise in FIG. 4A with the flexible hinge 6 as a fulcrum. As a result, the displacement is caused by the arm length from the flexible hinge 6 to the movable fulcrum pin 5 and the output end 7 of the displacement output piece 7 from the bending portion of the flexible hinge 6.
It is enlarged by this principle by the ratio to the length of the arm up to a,
It is taken out from the output terminal 7a.

[0004]

In the above conventional structure, the movable fulcrum pin 5 is used to transmit the displacement of the actuator 2 to the lever 4, and the lever 4 and the flexible hinge 6 are formed separately. . Therefore, the number of parts is large and the assemblability is poor, resulting in an increase in cost. Therefore, an object of the present invention is to provide a displacement enlarging mechanism for a piezoelectric actuator which has a simplified configuration and is inexpensive.

[0005]

In order to achieve the above object, the present invention is to form a flexible hinge, a lever, and a cylindrical fulcrum as a flexible fulcrum plate integrally from a leaf spring material. That is, the present invention provides an actuator comprising a layer type piezoelectric element.
Lever that abuts the tuator via a cylindrical fulcrum
And a flexible hinge supporting this lever,
Enlarge and output the displacement of the actuator by leverage principle
In the displacement expansion mechanism of the piezoelectric actuator,
Three legs and a torso spanning between the upper ends of these legs
Inverted mountain-shaped flat flexible fulcrum plate made of leaf spring
And the left and right legs of the flexible fulcrum plate are
The reverse, in which the multilayer piezoelectric element is arranged inside
Fixed to the left and right legs of the gate-shaped case, and for curling
The tip of the central leg of the flexible fulcrum plate formed in a more semi-cylindrical shape
With the end as the fulcrum, it is mounted on the upper surface
Into contact with the groove of the receiving plate, and further,
The displacement of the actuator from this part
(Claim 1). In that case,
Place the torso of the flexible fulcrum plate near the base of the left and right legs.
Fold it into a U-shape,
If the flexible hinge is configured to be torsionally deformed, the thickness of the case side wall can be reduced and the size can be reduced (claim 2).

[0006]

[Action] flexible hinge, the lever and the cylindrical fulcrums are aggregated in one piece reduces the number of parts, the assembly also becomes easy
In both cases, the flexible fulcrum plate is punched and bent by pressing a leaf spring material.
Production is extremely simple and inexpensive
You can do it for a price.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Two embodiments of the present invention will be described below with reference to FIGS. Note that the same reference numerals are used for the portions corresponding to the conventional example. Embodiment 1 FIGS. 1 to 3 show a basic embodiment of the present invention.
1 is a perspective view, FIG. 2A is a side view, and FIG.
FIG. 3 is a sectional view taken along the line B, and FIG. 3 is a perspective view of the receiving plate. In the figure, 9 is three legs parallel to each other and these legs
A flexible fulcrum plate having an inverted mountain shape comprising a body portion extending between the upper ends of the flexible hinge portions 9a, the left and right legs of which are a flexible hinge portion 9a corresponding to the conventional flexible hinge 6, and the body portion of a lever corresponding to the lever 4. Part 9
b and a fulcrum 9c corresponding to the central fulcrum pin 5
As is integrally formed from a leaf spring material by press molding. The fulcrum 9c is formed in a semi-cylindrical shape by curling. The front end of the flexible hinge portion 9a is provided with grooves for retaining on both sides, and the side wall 1a of the case 1 made of a low melting point alloy.
Is fixed by insert molding.

When the displacement of the actuator 2 is applied to the fulcrum 9c, the flexible hinge 9a bends and the lever 9b rotates, and the fulcrum 9c is displaced. The length of the arm from the center of the arc to the flexible hinge portion 9a and the bending portion of the flexible hinge portion 9a to the lever portion 9b
Is enlarged by the ratio to the arm length up to the output end. Here, as shown in FIG. 1, a mounting hole 10 is formed at the output end of the lever portion 9b.
Are mounted in an inverted L-shape. Thus, a displacement further enlarged by the length of the arm of the output lever 11 is obtained from the output end 11a. Also, as shown in FIG.
At both ends of the arc groove 3a of the receiving plate 3 in contact with the fulcrum 9c, ribs 3b abutting on both ends of the fulcrum 9c are integrally formed to prevent displacement of the receiving plate 3.

Embodiment 2 FIG. 4 is a perspective view showing Embodiment 2 in which a flexible hinge portion is configured to be torsionally deformed. In this embodiment, the flexible fulcrum
The torso of the plate 9 is bent in a U-shape near the bases of the left and right legs to form a fixing portion 9d, and the fixing portion 9d of the flexible fulcrum plate 9 extends along the side wall of the case 1. It is fixed. The flexible hinge portion 9a is located on both sides of the center leg of the body portion 9b.
Is formed in minutes . The flexible hinge 9a is torsionally deformed with the rotation of the lever 9b. According to such a configuration, the thickness of the side wall 1a can be reduced, and the device can be downsized.

[0010]

Effects of the Invention According to the present invention, the flexible hinge, by which is integrally formed from a plate spring material of the lever and a cylindrical fulcrum as flexible fulcrum plate, fewer parts and with the assembly is simplified, variable Flexible fulcrum plate is pressed by leaf spring material
Very easy to manufacture because it can be formed by punching and bending
Production cost of a single anchor can be performed for the apparatus becomes cheaper.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

2A is a side view of the apparatus shown in FIG. 1, and FIG.
It is sectional drawing which follows the -B line.

FIG. 3 is a perspective view of a receiving plate in FIG. 1;

FIG. 4 is a perspective view showing Embodiment 2 of the present invention.

5A is a side view of a conventional example, and FIG. 5B is a front view thereof.

[Explanation of symbols]

 2 Actuator 9 Flexible fulcrum plate 9a Flexible hinge part 9b Lever part 9c Support point part

Continued on the front page (56) References JP-A 2-113350 (JP, U) JP-A-24-24869 (JP, U) JP-A 63-135520 (JP, U) (58) Fields surveyed (Int) .Cl. ⁷ , DB name) H01L 41/09

Claims (2)

(57) [Claims] 1. A lever, which is in contact with an actuator comprising a laminated piezoelectric element via a cylindrical fulcrum, and a flexible hinge for supporting the lever, the displacement of the actuator is enlarged by leverage. In the displacement enlarging mechanism of the piezoelectric actuator that outputs, three legs parallel to each other and a bridge between upper ends of these legs are provided.
An inverted mountain-shaped flat flexible fulcrum plate consisting of
And the left and right legs of this flexible fulcrum plate
The laminated piezoelectric element is disposed inside as the flexible hinge.
To the left and right legs of the inverted gate-shaped case
Inside the flexible fulcrum plate formed into a semi-cylindrical shape by
The tip of the central leg is used as the fulcrum, and the laminated piezoelectric element is
Abut the groove of the receiving plate mounted on the upper surface of the
As the lever, from this part the actuator
A displacement enlarging mechanism for a piezoelectric actuator, wherein a displacement of the piezoelectric actuator is taken out . 2. The body of the flexible fulcrum plate is attached to the left and right legs.
Fold it into a U-shape near the base, and the center leg of the body
2. The displacement enlarging mechanism for a piezoelectric actuator according to claim 1 , wherein both side portions of the piezoelectric actuator are configured to be torsionally deformed as the flexible hinge .