JP2794756B2 - Piezoelectric actuator for mirror drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an electrostriction used for optical fiber communication or optical applied measurement control or a mirror driving electrostriction or a piezoelectric actuator using a piezoelectric element as a driving source.

[Conventional technology]

2. Description of the Related Art Conventionally, an electromagnetic actuator has been widely used as a driving source for a mirror used for splitting / coupling an optical signal.

Such an electromagnetic actuator generates a magnetic field by passing a current through a coil, and drives the movable member using the magnetic force generated by the current.

For this reason, copper loss and iron loss occur, which not only requires large input energy, but also causes problems such as heat generation and magnetic interference.

For this reason, a mirror driving voltage actuator using an electrostrictive or piezoelectric element as a driving source, which has high electric / mechanical energy conversion efficiency, can be driven with low power, generates little heat, and has no magnetic interference, has been considered. FIG. 1 is a perspective view showing an example of a conventional mirror driving piezoelectric actuator.

The arm 18 has a thin plate-shaped first hinge 19 at the other end 18a, and further has thin plate-shaped second and third hinges 20 and 21 in the lateral direction (on both sides in the width direction) across the first hinge 19. ing.
The first hinge 19 is coupled to the end face of one end 22a in the direction of expansion or contraction (arrow D) of the electrostrictive or piezoelectric element 22. One end of the second and third hinges 20, 21 is connected to the other end of the fixed member 23. Are combined. The other end 22b of the electrostriction or the expansion and contraction direction of the piezoelectric element 22 is also connected to the fixing member 23.

FIG. 5 is a perspective view showing details of the arrangement of the first, second, and third hinges 19, 20, and 21 of the conventional example shown in FIG. Second
And the third hinges 20 and 21 are provided on the left and right sides (on both sides in the width direction) of the first hinge 19, and the position in the height (thickness) direction is different from the position of the first hinge 19. And are arranged at the same height with a step of a predetermined size.

When a voltage is applied to the electrostriction or the piezoelectric element 22 of the mirror driving piezoelectric actuator having such a configuration, an operation as shown in FIG. 6 is performed. That is, electrostrictive or piezoelectric element 22 extends in the arrow D ₁ direction, it displaces the first hinge 19 in the arrow D ₁ direction. On the other hand, one end of each of the second and third hinges 20 and 21 is fixed to the fixing member 23, and the other end is fixed to the arm 18. Further, since there is a step with the first hinge 19, the thin plate-shaped first 1, second and third hinges 19,20
And 21 undergo bending deformation in the direction of arrow E, thus causing the arm 18 to pivot in the direction of arrow E. As a result, the electrostriction or the amount of displacement of the piezoelectric element 22 is transmitted to the mirror 24 coupled to the side surface of the arm 18 in an enlarged manner.
The mirror 24 can move in the direction of arrow E to change the optical path of the optical fiber or optical applied measurement control.

[Problems to be solved by the invention]

The above-described conventional mirror driving piezoelectric actuator has a complicated structure having a step between the first hinge and the second and third hinges, and furthermore, the arm, the hinge and the fixing member have high rigidity. Since the material has an integral molding structure, there is a drawback that processing is not easy and is not suitable for automation.

Therefore, the processing means is limited. For example, the wire cut electric discharge machining means is optimal for small-quantity production, but has a disadvantage that the machining time is long and the cost is very high. In addition, there are other processing means such as a lost wax casting method and a powder metallurgy method, but the size and shape are greatly restricted.

[Means for solving the problem]

The mirror driving piezoelectric actuator according to the present invention includes an arm to which a mirror is fixed on one side surface, a U-shaped fixing member, and one end in the direction of expansion and contraction to be accommodated in the fixing member, on the U-shaped bottom of the fixing member. The attached electrostrictive or piezoelectric element, and a side plate of the arm to which the mirror is fixed and a thin plate having both ends fixed to the other end of the arm and the piezoelectric element in the direction of expansion and contraction so as to be parallel to the electrostrictive or piezoelectric element. -Shaped first hinge and a step having a predetermined dimension in a direction perpendicular to the side surface of the first hinge and on the same side as the side surface of the first hinge, and both sides in the width direction of the first hinge And a thin plate-shaped second and third hinges having one end fixed to the arm and the other end fixed to the fixing member so as to be positioned at the first position and the second position. , The third hinge and the first, No. 2,
An end of the arm to which the third hinge is fixed, and a displacement transmitting portion between the first hinge and the electrostrictive or piezoelectric element for transmitting the displacement of the electrostrictive or piezoelectric element, press-punches any thin metal plate. At that time, half of a part of arbitrary shape or half of the whole circumference is half-punched to form a caulked part at the required part of the end of the arm and the displacement transmitting part of the fixed member, and the sheets are stacked one by one and scissors It has a structure in which it is closely laminated by the frictional force of the cut surface of the half-bent projection of the crimping and crimping portion.

[Action]

The present invention utilizes a press stamping process, which is a process method excellent in dimensional accuracy, to fix a fixing member, a first, a second, and a third
And an end of an arm to which the first, second, and third hinges are fixed, and a displacement transmitting portion between the first hinge and the electrostrictive or piezoelectric element for transmitting the electrostrictive or piezoelectric element displacement. However, any thin metal plate is press-punched, and at that time, a part of an arbitrary shape is half-punched or the entire circumference is half-punched at key points of the end of the arm, the fixing member, and the displacement transmitting part, and the caulking part is formed. Is formed, and the sheets are stacked one by one, stuck together, and half of the caulked portion is punched out, and the structure is formed in close contact with the frictional force of the cut surface of the projection.

〔Example〕

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

FIG. 1 (a) is a perspective view showing a piezoelectric actuator for driving a mirror according to a first embodiment of the present invention, and FIG. 1 (b) is an enlarged cross-sectional view of a swaged section taken along the line AA of FIG. 1 (a). FIG. 2 is a perspective view showing an operation state of the embodiment of FIG. 1 (a).

The arm 1 has a thin plate-shaped first hinge 2 at its end 1a, and has thin plate-shaped second and third hinges 3, 4 laterally (on both sides in the width direction) across the first hinge 2. I have. The first hinge 2 is coupled to the end face of one end 5 a in the direction of expansion or contraction (arrow B) of the electrostrictive or piezoelectric element 5, and one end of the second and third hinges 3 and 4 is connected to the end face of the fixed member 6. Are combined. The other end 5 b of the electrostriction or the displacement direction of the piezoelectric element 5 is also connected to the fixing member 6. A mirror 7 is connected to one side surface of the arm 1. The position of the second and third hinges 3, 4 in the height (thickness) direction is shifted from the position of the first hinge 2 and has a step of a predetermined size. 3 and the third hinge 4 are arranged at the same height.

The end 1a of the arm 1, the hinges 2, 3, 4, the fixing member 6, and one end 5a of the electrostriction or expansion / contraction direction of the piezoelectric element 5 are thin metal plates 8 of high rigidity metal material (thickness of 0.15 to 0.5 mm). When press punching is performed, a part of an arbitrary shape is partially cut out or the whole circumference is half cut out at a required portion of the end of the arm 1, the fixing member 6, and the one end 5a in the direction of the electrostrictive or electrostrictive element 5. In this case, a square-shaped caulking portion 9 is formed in advance, one by one, stacked and sandwiched, and closely adhered and laminated by the frictional force of the cut surface 8a of the projection 9a of the caulking portion 9.

When a voltage is applied to the electrostriction of the piezoelectric actuator for driving a mirror having such a structure or the piezoelectric element 5, an operation as shown in FIG. 2 is performed. That electrostrictive or piezoelectric element 5 is extended in the arrow B ₁ direction, it displaces the first hinge 2 in the arrow B ₁ direction. On the other hand, the second and third hinges
One end of each of 3 and 4 is fixed to the fixing member 6 and the other end is fixed to the arm 1 and has a step between the first hinge 2 and the thin plate-shaped first, second and third hinges 2. , 3 and 4 undergo bending deformation in the direction of arrow C, and the arm 1 also pivots in the direction of arrow C. As a result, the mirror 7 coupled to the side surface of the arm 1 is transmitted with the electrostriction or the displacement of the piezoelectric element 5 expanded and moves in the direction of arrow C to change the optical path of the optical fiber or the optical applied measurement control. Can be.

FIG. 3 is a perspective view showing an example of a mirror driving piezoelectric actuator arranged in parallel with a plurality of units according to a second embodiment of the present invention.

In FIG. 3, a plurality of arms 10 each have a thin plate-shaped first hinge 11 at each end 10a and two thin plate-shaped second hinges 11 in the width direction (on both sides in the lateral direction) with the first hinge 11 interposed therebetween. It has third hinges 12,13. The first hinge 11 is coupled to one end 14a of the corresponding electrostrictive or piezoelectric element 14 in the direction of expansion and contraction, and the second and third hinges 12 and 13 are connected to the end surface of the fixed member 15. Is joined to. A mirror 16 is connected to one side surface of each arm 10.
The fixing member 15 is a single member, and is commonly used for all the mirror driving piezoelectric actuators. That is, it is a part of a member constituting a mirror driving piezoelectric actuator which is configured by arranging a plurality of mirror driving piezoelectric actuators in parallel.
Are provided corresponding to the hinges 12 and 13, and are configured to fix each of them. The positional relationship between the first hinge 11, the second hinge 12, and the third hinge 13 is the same as that of the embodiment of FIG.
12, 13 are provided on both sides of the first hinge 11 in the width direction with the first hinge 11 interposed therebetween, and have a step between the first hinge 11 in the thickness direction thereof and both are arranged at the same height. Have been.

Also in the second embodiment, the arm 10 and the hinges 11, 12, 13
The fixing member 15 and the electrostrictive or one end 14a of the piezoelectric element 14 in the direction of expansion and contraction are pressed in advance so as to form a caulking portion 17 on a thin metal plate 16 of a highly rigid metal material, and are stacked one by one and sandwiched, This is a laminated structure in which the protrusions of the caulking portion 17 are closely adhered and laminated by the frictional force of the cut surface.

The plurality of mirror driving piezoelectric actuators arranged in parallel in this way perform the same operation as the mirror driving piezoelectric actuator of the first embodiment, and therefore have the same effects.

〔The invention's effect〕

As described above, the present invention uses the press punching process, and is provided between the arm of the mirror driving piezoelectric actuator, the hinge, the fixing member, the electrostriction or the piezoelectric element, and the displacement of the piezoelectric element between the piezoelectric element and the first hinge. Is transmitted to the first hinge in a laminated structure, and caulking is used as the joining means, thereby facilitating the automation of production and producing the piezoelectric actuator with high dimensional accuracy.

[Brief description of the drawings]

FIG. 1 (a) is a perspective view showing a mirror driving piezoelectric actuator according to a first embodiment of the present invention, and FIG. 1 (b) is an enlarged cross section of a swaged portion taken along the line AA of FIG. 1 (a). FIG. 2 is a perspective view showing an operation state of the embodiment shown in FIG. 1, FIG. 3 is a perspective view showing a mirror driving piezoelectric actuator according to a second embodiment of the present invention, and FIG. FIG. 5 is an enlarged perspective view showing an arrangement of hinges in the conventional example shown in FIG. 4, and FIG. 6 is a perspective view showing an operation state of the conventional example shown in FIG. 1,10,18 ... arm, 2,11,19 ... first hinge, 3,12,2
0 ... second hinge, 4,13,21 ... third hinge, 5,14,2
2 ... electrostrictive or piezoelectric element, 6, 15, 23 ... fixing member, 7,
16,24 ... Mirror, 8,16 ... Thin metal plate, 9,17 ... Caulking part, 5a, 14a, 22a ... Displacement transmitting part.

Claims (1)

(57) [Claims] 1. An arm to which a mirror is fixed on one side surface, a U-shaped fixing member, and an electrostriction in which one end in the direction of expansion and contraction is attached to the U-shaped bottom of the fixing member so as to be accommodated in the fixing member. Alternatively, a piezoelectric element and a thin plate-shaped first side in which both ends of the arm are fixed to the side of the arm to which the mirror is fixed and the other end of the arm and the piezoelectric element in the direction of expansion and contraction so as to be parallel to the electrostrictive or piezoelectric element. A hinge and a step having a predetermined dimension in a direction perpendicular to a side surface of the first hinge;
Second and third hinges, one end of which is fixed to the arm and the other end of which is fixed to the fixing member so as to be located on the same side with respect to the side surface of the first hinge and on both sides in the width direction of the first hinge. A mirror driving piezoelectric actuator comprising: a fixing member; first, second, and third hinges; an end of an arm to which the first, second, and third hinges are fixed; The displacement transmitting portion between the hinge and the electrostrictive or piezoelectric element for transmitting the displacement of the electrostrictive or piezoelectric element is formed by press-punching an arbitrary thin metal plate. Part of the desired shape is half-punched or the whole circumference is half-punched to form a caulked part, and then the sheets are stacked one by one and clamped, and the frictional force of the cut surface of the half-punched protrusion of the caulked part A piezoelectric element for driving a mirror, characterized by having a structure of close contact lamination. Chueta.