JP4210487B2 - Displacement magnification mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a displacement enlarging mechanism.
[0002]
[Prior art]
Conventionally, there is a displacement magnifying mechanism as one of the devices used for fine movement control such as positioning of an optical stage. FIG. 6 shows a conventional displacement magnifying mechanism. The base 2 of the displacement magnifying mechanism 1 is provided with an actuator 3 in which a piezoelectric actuator element or the like is incorporated to generate a driving displacement. An attachment member 11 that receives the displacement of the actuator 3 is provided between the actuator 3 and the link body 5. Further, a pair of wedge members 13 for adjusting the distance between the attachment member 11 and the link body 5 and adjusting the preload to the actuator 3 are disposed between the attachment member 11 and the link body 5.
The driving displacement generated from the actuator 3 is transmitted to the link body 5 via the attachment member 11, further enlarged by the lever body 7 and transmitted to the output body 9, and the output end 9 a of the output body 9 is moved in the direction of the arrow. Move to.
In such a displacement enlarging mechanism 1, the link body 5, the lever body 7, and the output body 9 are centered on the actuator 3 in order to enlarge the displacement of the actuator 3 and transmit it to each output end 9 a with high accuracy. It is configured to have a symmetric relationship.
[0003]
[Problems to be solved by the invention]
However, in the conventional displacement enlarging mechanism 1, due to the processing accuracy of the parts constituting the displacement enlarging mechanism 1 such as the output body 9, the lever body 7, the link body 5, or the assembly accuracy when assembling these components, The straightness of the output end 9a of the output body 9 may deteriorate. In other words, a deviation occurs between the direction in which the output end 9a of the output body 9 should originally travel and the direction in which the output end 9a actually travels. For example, the traveling direction A of the output end 9a is perpendicular to the paper surface of the figure (defined here as the yawing direction), or is horizontal to the paper surface of the figure and perpendicular to the displacement direction of the actuator 3 (This is defined as the pitching direction here).
The straightness is better as the deviation is smaller. However, the straightness is determined at the stage where the displacement magnifying mechanism 1 is assembled, and there is no means for correcting the straightness at the time of assembly.
Accordingly, the present invention has been made in view of such a conventional problem, and provides a displacement magnifying mechanism that can easily correct the straightness of the output body and improve the accuracy of straightness. With the goal.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, a displacement enlarging mechanism according to the present invention is a displacement enlarging mechanism in which a driving displacement generated by an actuator having a piezoelectric actuator element is expanded by lever means and transmitted to an output body. Has a pair of symmetrical output ends, an actuator receiving portion that contacts the actuator at one end, and an attachment member that contacts the lever means at the other end, and the displacement enlarging mechanism outputs the attachment member and the actuator. Compensating means for translating, decentering and assembling with respect to the symmetrical axis of the end portion, the center axis of the actuator receiving portion of the attachment member and the central axis of the actuator are the diameter of the actuator with respect to the symmetrical axis line of the output end portion. It is configured to be eccentric in the direction.
The attachment member may include a sliding portion that can slide linearly with respect to the lever means.
The lever means comprises a link body extending symmetrically with respect to the symmetry axis, and a pair of left and right lever bodies connected to the link body and the output body, and elastic means for pressing each lever body to the output body side. May be provided.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings.
Embodiment 1 FIG.
FIG. 1 shows a plane of the displacement enlarging mechanism according to the first embodiment. The displacement enlarging mechanism 21 includes an actuator 23, a base body 25, a link body 27, a pair of left and right lever bodies 29, and an output body 31. The actuator 23 is a cylindrical member in which a piezoelectric actuator element is incorporated, and generates a driving displacement. Here, the link body 27 and the lever body 29 constitute a lever means.
A hemispherical projection 33 is formed on the actuator 23, and an attachment member 35 is inserted between the actuator 23 and the link body 27.
The attachment member 35 has a substantially rectangular parallelepiped shape, abuts on the input portion 27a of the link body 27, and has a conical concave portion 36 formed on the actuator 23 side, and has a projection 33 and a circumferential shape as an actuator receiving portion. Contact.
[0006]
The link body 27 has a symmetrical shape with respect to the symmetry axis C. A pair of lever bodies 29 adjacent to the link body 27 are arranged symmetrically with respect to the symmetry axis C. Each lever body 29 includes a fulcrum portion 37 at an end portion near the center of the base body 25 and an action point portion 39 at an end portion near the outer side of the base body 25. Each lever body 29 is connected to the base body 25 so as to be swingable about the fulcrum part 37, and is connected to the output body 31 at the action point part 39. Each lever body 29 includes a force point portion 41 between the fulcrum portion 37 and the action point portion 39, and the force point portion 41 is connected to the link body 27.
The output body 31 extends symmetrically with respect to the symmetry axis C, and is connected to the link body 27 via a pair of left and right bending spring portions 43.
An output end 31 a to which a movable object (not shown) that transmits displacement of the output body 31 by the actuator 23 is connected is provided in the output body 31 symmetrically with respect to the symmetry axis C.
[0007]
On the other hand, the base body 25 has a rectangular parallelepiped recess 45 at the end opposite to the output body 31, and a cylindrical through hole 47 extends from the bottom surface of the recess 45 toward the output body 31. The actuator 23 is inserted into the through hole 47. The through hole 47 is formed to have a gap with respect to the actuator 23 so that the actuator 23 can be moved minutely in the yawing direction or the pitching direction.
In addition, a rectangular parallelepiped push plate 49 corresponding to the shape of the recess 45 is fitted into the recess 45. The push plate 49 is detachably attached to the recess 45 by a pair of left and right screws 51, and by tightening the screws 51, the actuator 23 is pressed toward the attachment member 35, and a suitable preload is applied to the actuator 23.
[0008]
FIG. 2 shows the positional relationship between the attachment member 35, the actuator 23, the link body 27, and the output end 31 a of the output body 31.
As described above, the link body 27 and the output end 31a of the output body 31 are symmetrical with respect to the symmetry axis C.
On the other hand, the center axis 36c of the recess 36 of the attachment member 35 coincides with the center axis 23c of the actuator 23, and is arranged eccentrically with respect to the symmetry axis C in the yawing direction or the pitching direction.
[0009]
Next, the operation of the displacement magnifying mechanism 21 will be described with reference to FIG.
A predetermined displacement is generated from the actuator 23 by applying a predetermined voltage. Such displacement is transmitted to the link body 27 via the hemispherical projection 33 and the attachment member 35, and the link body 27 moves. By the movement of the link body 27, a force is applied to the pair of lever bodies 29 via the force point portion 41, and the left and right lever bodies 29 swing around the fulcrum portion 37. Due to the swinging of the lever body 29, the input displacement transmitted from the link body 27 to the lever body 29 via the force point portion 41 is enlarged by the lever principle and output to the output body 31 via the action point portion 39. It is transmitted as displacement. The expansion ratio of the input displacement and the output displacement at this time is determined by the ratio between the distance between the force point portion 41 and the fulcrum portion 37 in the lever body 29 and the distance between the action point portion 39 and the fulcrum portion 37. Thus, the displacement expanded by the pair of lever bodies 29 is transmitted to the output body 31, and the output body 31 moves accordingly, and the final displacement of the displacement enlarging mechanism 21 is the pair of output end portions of the output body 31. It is output from 31a.
[0010]
Next, the straightness correction of the output body 31 in the displacement enlarging mechanism 21 that performs such an operation will be described.
For example, the displacement magnifying mechanism 21 is assembled with the attachment member 35 and the actuator 23 aligned with the symmetry axis C, and the straightness of the output body 31 is measured.
As a result of measurement, when the straightness of the output body 31 is not good and the traveling direction B of the output end 31a of the output body 31 is shifted in the yawing direction or the pitching direction, the deviation in the yawing direction or the pitching direction is reduced. In this manner, the attachment member 35 and the actuator 23 are moved and assembled with respect to the symmetry axis C.
When straightness correction is not performed as in the prior art, the straightness of the output body 31 has a deviation of about ± 30 seconds as an angle in the yawing direction or the pitching direction. However, in this way, by using a correction means that moves the attachment member 35 and the actuator 23 in parallel with the axis of symmetry C to 10 to 100 μm in the yawing direction or the pitching direction and decenters and assembles them, the angle is about ± 3 seconds. In other words, the deviation can be corrected to about 1/10 to improve the straightness.
[0011]
Embodiment 2. FIG.
FIG. 3 shows a plan view of a displacement magnifying mechanism according to Embodiment 2 of the present invention. The configuration of the displacement enlarging mechanism 61 includes an attachment member 63 and a link body 64 instead of the attachment member 35 and the link body 27 in the apparatus of the first embodiment shown in FIG. Instead of the base body 25, a lever body 65 and a base body 62 are provided, and a spring mechanism 66 for pressing the lever body 65 is further added. Note that the same reference numerals as those in FIGS. 1 and 2 described in the first embodiment are the same or similar components, and thus detailed description thereof is omitted.
[0012]
The attachment member 63 and the actuator 23 are disposed so as to coincide with the symmetry axis C in the left-right direction.
As shown in detail in FIG. 4, the attachment member 63 is provided with a belt-like protrusion 67 having a rectangular cross section on one side of a rectangular parallelepiped. A conical recess 68 is formed on the opposite surface.
On the other hand, the input portion 69 of the link body 64 is formed with a longitudinal groove 70 that can be fitted in the belt-like projection 67 and can slide in the yawing direction. The height of the belt-like protrusion 67 is slightly smaller than the depth of the vertical groove 70, and the attachment member 63 abuts on the tip surface 71 of the input portion 69.
[0013]
Next, a spring mechanism 66 as elastic means for pressing the left and right lever bodies 65 will be described with reference to FIG.
Conical recesses 72 are respectively formed on the surfaces of the left and right lever bodies 65 facing the base 62. In addition, the base body 62 is provided with a through hole 74 in which an internal thread 73 is formed on the inner periphery.
A semicircular pressing member 75 contacts the recess 72, and one end of a coil spring 77 contacts the flat surface of the pressing member 75. The other end of the coil spring 77 abuts on a screw member 79 having a male screw 78 on the outer periphery. The screw member 79 is screwed into the through-hole 74, and a screw driver (not shown) is inserted into the groove 80, and the screw member 79 is screwed into the lever body 65, whereby the coil spring 77 is compressed and the lever body 65 is attached to the lever body 65 as desired. It is configured to give power.
[0014]
Next, the straightness correction of the output body 31 will be described.
For example, the attachment member 63 and the actuator 23 are assembled in the yawing direction so as to coincide with the symmetry axis C, and the screw member 79 is screwed until the urging force of the left and right spring mechanisms 66 pressing the lever bodies 65 becomes equal. .
The straightness of the output body 31 is measured with the displacement magnifying mechanism 21 assembled.
When the straightness of the output body 31 in the yawing direction is not good as a result of the measurement, the attachment member 63 and the actuator 23 are moved in the yawing direction by 10 to 100 μm so that the deviation in the yawing direction is reduced.
On the other hand, when the deviation in straightness in the pitching direction is large, the amount of force applied to the output body 31 from each lever body 29 is changed by changing the screwing amount of the left and right screw members 79 to change the urging force that presses the lever body 29. The balance is changed to reduce the deviation of the output body 31 in the pitching direction.
[0015]
The present invention described above is not limited to the above, and can be implemented with appropriate modifications. For example, the attachment member 63 according to the second embodiment has the belt-like protrusion 67. However, the attachment member 63 is not limited to this as long as the attachment member 63 can slide in the yawing direction with respect to the input portion 69 of the link body 64. Alternatively, a concave portion may be provided in the center of the attachment member, and a convex portion may be provided at the input portion of the link body.
[0016]
【The invention's effect】
As described above, according to the displacement magnifying mechanism of the present invention, the central axis of the actuator receiving portion of the attachment member and the central axis of the actuator are in the radial direction of the actuator with respect to the symmetry axis of the output end of the output body. Since it is configured to be eccentric, the straightness of the output body can be easily corrected, and a displacement enlarging mechanism with improved straightness accuracy can be provided.
[Brief description of the drawings]
FIG. 1 is a plan view of a displacement enlarging mechanism according to Embodiment 1 of the present invention.
2 is a front view schematically showing a positional relationship among output members of an attachment member, an actuator, a link body, and an output body in FIG. 1; FIG.
FIG. 3 is a plan view of a displacement enlarging mechanism according to Embodiment 2 of the present invention.
4 is a perspective view showing a sliding structure of the attachment member of FIG. 3. FIG.
5 is a plan sectional view showing a spring mechanism that presses the lever body of FIG. 3; FIG.
FIG. 6 is a plan view of a conventional displacement enlarging mechanism.
[Explanation of symbols]
21, 61 ... Displacement magnifying mechanism, 23 ... Actuator, 23c ... Center axis, 27, 64 ... Link body (lever means), 29, 65 ... Lever body (lever means), 31 ... Output body, 31a ... Output end, 35, 63 ... attachment member, 36 ... concave portion (actuator receiving portion), 36c ... central axis, C ... symmetry axis.

Claims (3)

In a displacement enlarging mechanism for enlarging the displacement for driving generated by an actuator having a piezoelectric actuator element by lever means and transmitting it to an output body,
The output body includes a pair of symmetrical output ends,
An actuator receiving portion that contacts the actuator at one end;
An attachment member that contacts the lever means at the other end;
The displacement magnifying mechanism includes a correction unit that translates the attachment member and the actuator with respect to the axis of symmetry of the output end, and decenters the assembly.
Displacement central axis of the central shaft and the actuator of the actuator receptacle of the attachment member, relative to said axis of symmetry of the output end, in the radial direction of the actuator, characterized in that the eccentrically configured to be able to Enlarging mechanism.   The displacement magnifying mechanism according to claim 1, wherein the attachment member includes a sliding portion that can slide linearly with respect to the lever means. The lever means includes a link body extending symmetrically with respect to the symmetry axis, and a pair of left and right lever bodies connected to the link body and the output body,
The displacement magnifying mechanism according to claim 2, further comprising elastic means for pressing each lever body toward the output body.

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