JPH01169184A - Piezoelectric actuator - Google Patents

Abstract

PURPOSE:To drive a driven member to be positioned accurately further in a good response by providing the first displacement magnifying mechanism adapted to one end of a piezoelectric element and the second displacement magnifying mechanism having a pair of links pivotally moving connected to an output member. CONSTITUTION:A yoke-shaped member 80, having a pair of input arms and a pair of output arms 100 and 102, fixedly surrounds the first displacement magnifying mechanisms 128 and 130 spreading a relative displacement amount along the axial line of another end 50b of a piezoelectric element 50 as the pivotal movement around elastic hinges 96 and 98 in the point end of the output arms 100, 102. While a pair of links 110 and 112 fixedly surround the second displacement magnifying mechanism 132 reciprocating an output member 120 along an axial line 34.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to actuators, and more particularly to piezoelectric actuators suitable for use, for example, as actuators for hydraulic servo valves.

Prior Art A force motor has been used as an actuator for a high-response hydraulic servo valve, and the spool of the valve is driven by the force motor in a direct-acting manner. Furthermore, in order to speed up the operation of servo valves and the like, a single-stage displacement magnifying type piezoelectric actuator has already been proposed, which incorporates, for example, a laminated piezoelectric element and a displacement magnifying mechanism that magnifies its minute displacement by lever action. In order to increase the output displacement of the actuator and further speed up the driving of the driven member, as described in, for example, Japanese Utility Model Application No. 61-44080 and Japanese Utility Model Application No. 61-103679,
A piezoelectric actuator incorporating a two-stage displacement amplification mechanism is already known.

Problems to be Solved by the Invention However, in the structure described in Japanese Utility Model Application Publication No. 61-44080, since the displacement expansion in the second stage is performed by fluid pressure using a nozzle and a flapper, it is difficult to use a lever. There is a problem that the response is worse than the one that uses action. Furthermore, in the embodiment shown in FIGS. 1 and 5 of this publication, two piezoelectric elements are used that act in opposite directions.

Therefore, in the case of such a structure, there is a problem that unless the control signals to the two piezoelectric elements are mutually controlled accurately and in a timely manner, the actuator will not operate properly and accurately. Furthermore, in the structure described in Japanese Utility Model Application Publication No. 61-103679, a lever mechanism in which the lever contacts the fulcrum is also used in the first stage displacement magnification mechanism, and the output displacement of the piezoelectric element is are very small, and because there is play between them when the lever begins to pivot around the fulcrum, it is not possible to perform the first stage of displacement expansion accurately, and therefore the driven member cannot be accurately adjusted. It is difficult to drive and position.

Further, in Japanese Utility Model Application Publication No. 61-50448, the first stage displacement amplifying mechanism is a lever mechanism using an elastic hinge as a fulcrum,
The second stage displacement magnification mechanism is a mechanism that utilizes the elastic deformation of a spring, and a printing hammer configured so that the printing pin is driven at high speed according to the control signal to the piezoelectric element. Are listed. However, in this printing hammer, unless the rigidity of the leaf spring is increased, its resonance point will be lowered, and if the rigidity of the leaf spring is increased, the lever arms of the first stage displacement magnification mechanism will be pushed apart from each other. I ended up
Therefore, accurate and smooth operation is no longer possible, and furthermore, since the displacement expansion in the second stage is performed by elastic deformation of the leaf spring, it is impossible to accurately position the driven member connected to it. Even if this structure is applied to an actuator, it is not possible to drive and position the driven member accurately and responsively.

In view of the above-mentioned problems with conventional piezoelectric actuators, the present invention is capable of accurately and responsively driving and positioning a driven member, is compact, has a paper storage, and is durable. The aim is to provide an excellent piezoelectric actuator for -2 Means for Solving the Problems According to the present invention, an output member configured to be connected to a driven member that reciprocates along an axis, and an output member configured to be connected to a driven member that reciprocates along an axis; a piezoelectric element arranged along the
a retainer that supports one end of the piezoelectric element; a pair of input arms and a pair of output arms that are pivotally supported by an elastic hinge supported by the retainer; a second displacement amplifying mechanism having a pair of links pivotally connected to the tip of the output arm at one end, pivotally connected to each other at the other end, and pivotally connected to the output member; This is accomplished by a piezoelectric actuator that includes.

According to the above-described configuration, the displacement of the piezoelectric element is accurately magnified by the lever action of the first displacement magnifying mechanism using the elastic hinge as a fulcrum, and the displacement thus magnified is further magnified by the second displacement magnifying mechanism. Therefore, the driven member can be driven and positioned more accurately than when a structure in which the lever directly contacts the fulcrum is adopted as the first displacement amplifying mechanism. Further, since the second piezoelectric element has a structure that mechanically expands the displacement, the responsiveness of the actuator can be improved compared to a case where the second stage displacement is expanded by fluid pressure. In addition, only one piezoelectric element is required, so the actuator can be configured at a lower position than when multiple piezoelectric elements are used, and energization to the piezoelectric element can be easily controlled. . In addition, the piezoelectric element is subjected to compressive stress only in the direction along the axis from the retainer and the input arm of the first displacement amplification mechanism, and is not subjected to bending stress or shear stress, improving the durability of the piezoelectric element. This can improve the durability of the actuator.

Also, each piezoelectric element has a pair of structures.
Since the second displacement magnification mechanism and the second displacement magnification mechanism are incorporated, excessive sliding resistance is not applied to the output member etc. compared to a structure in which these mechanisms do not form a pair, thereby ensuring smooth operation of the actuator. can be secured.

Furthermore, since the second displacement amplifying mechanism is adapted to amplify the displacement by a lever action or a toggle action, it can be driven much more accurately than when a leaf spring is used for the second displacement amplifying mechanism. The member can be driven and positioned.

According to one detailed feature of the invention, the output arm extends substantially along the piezoelectric element. Due to the structure of the first displacement magnification mechanism, the length of the output arm must be relatively long, but according to the above configuration, the output arm extends substantially along the piezoelectric element. , the actuator can be configured more compactly than in the case otherwise.

According to another detailed feature of the invention, the pair of input arms, the pair of output arms, and the pair of links are each disposed substantially symmetrically to each other with respect to the axis.

According to the bending configuration, it is possible to further reduce the possibility that bending stress or the like will be applied to the piezoelectric element, and the actuator can be operated smoothly.

According to yet another detailed feature of the invention, the pair of links are pivotally connected to the output arm and the output member. According to the rattling configuration, the resistance is smaller than when the links are connected five times by elastic hinges, and therefore the links can pivot easily and smoothly. The conversion efficiency of converting the displacement of the output arm into the displacement of the output member can be improved.

According to yet another detailed feature of the invention, the pair of links are connected to the output arm and the output member by a resilient hinge. According to the swinging configuration, play at the start of pivoting can be reduced compared to a case where the links are connected by a pivot, so that accurate operation of the actuator can be ensured.

According to yet another detailed feature of the invention, each of the pair of links is pivotally supported by a resilient hinge supported by a retainer. According to this configuration, the second displacement amplification mechanism performs the second stage displacement amplification by two actions.

According to yet another detailed feature of the invention, the output member is configured to be pivotally connected to the driven member. According to this configuration, the actuator can operate smoothly even when the output member is not arranged in exact alignment with the axis or when the forces applied to the output member by a pair of links are different from each other. can be ensured.

In this specification, "effective arm length" refers to the theoretical arm length when the arms of the first and second displacement amplifying mechanisms expand the displacement by lever action or toggle action. , and refers to, for example, the distance between the pivot centers of the ends of the arm or the centers of the elastic hinges. Furthermore, in this specification, the term "piezoelectric element" refers to an element that has the physical property of increasing or decreasing its volume in a predetermined direction by controlling the voltage or current of an input electrical signal.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will be explained in detail below by way of example embodiments with reference to the accompanying figures.

Embodiment FIGS. 1 and 2 are vertical sectional views and plan sectional views, respectively, showing one embodiment of the piezoelectric actuator according to the present invention applied to a hydraulic servo valve, and FIGS. 3 to 5 are Line ■-■ in Figure 1, line IV-IV in Figure 2, and line v, respectively.
6 is a perspective view showing the second displacement magnification mechanism of the embodiment shown in FIGS. 1 to 5.

In these figures, 10 generally indicates an actuator, and 12 indicates a spool valve controlled by the actuator. The spool valve 12 is the valve housing 1
4, and a sleeve 16 is fitted into the housing. The housing and sleeve cooperate with each other to provide hydraulic supply oil passage 18, control oil passages 20 and 22, and return oil passage 2.
4 and 26, and although not shown in detail in the figure, these oil passages are connected to boats 28.30a and 26, respectively.
30b and 32. The sleeve 16 has an axis 3
A spool 36 as a valve element is fitted so as to be able to reciprocate along 4, and the spool controls the flow direction and flow rate of the hydraulic oil by displacing along the axis.

Valve housing 14 is integrally connected at one end to one end of actuator housing 38 by bolt 40 . The valve housing also has passages 42 and 44 that connect the oil passages 24 and 26, respectively, to the interior of the housing 38. A housing 48 housing a sensor 46 therein is integrally connected to the other end of the valve housing 14, and the sensor 46 detects the position of the spool 36 and sends a signal indicating the position to a control (not shown). It is designed to output to the device.

A piezoelectric element 50 is disposed within the housing 38 substantially along the axis 34, ie, such that relative displacement between the ends occurs substantially along the axis. One end 50 of the piezoelectric element 50
a (the end on the side of the valve 12) is the support portion 52a of the retainer 52;
is in contact with and is supported by this. The retainer 52 has a flange portion 54, and the outer peripheral surface of the flange portion contacts the inner peripheral surface of the housing 38 so as to be reciprocating along the axis 34. The retainer also has a pair of arm portions 56 and 58 located symmetrically with respect to the axis 4134,
Each of these arm parts has a flange part 60 at its tip.
and 62 are integrally provided.

The cylindrical outer peripheral surface of these flanges is connected to the housing 38.
It is in contact with the inner circumferential surface of the cylinder so as to be able to reciprocate along the axis. The flat surface 66 of the plate-shaped portion 64 and the flat surface 68 of the flange portion 54 that protrude toward the valve by the support portion 52a are connected to the housing 3.
8, and the flange portions 60 and 6
The two flat surfaces 72 and 74 abut flat surfaces 76 and 78, respectively, of the housing 38, thereby preventing rotation of the retainer about its axis.

A disk-shaped flange portion 82 of a yoke-shaped member 80 is integrally connected to the flange portions 60 and 62 by bolts 84 . The yoke-shaped member 80 has a base portion 86 integrally formed with a flange portion 82 and a flat surface 88 of the base portion.
engages the flat surface 90 of the housing 38, thereby
Rotation about the axis is prevented. Further, a shaft 92 that protrudes along the axis in a direction opposite to the retainer is integrally formed on the flange portion 82, and the shaft has a male thread 94.

Resilient hinges 96 and 98 are integrally provided on the base portion 86 at positions symmetrical about the axis 34 and spaced apart from the arm portions 56 and 58 by substantially 90 degrees around the axis. These resilient hinges extend substantially along the piezoelectric element 50 in the illustrated embodiment to the output arms 100 and 1.
One end (base end) of 02 is integrally connected to the base part.

The base ends of the output arms 100 and 102 are integrally connected by elastic hinges 104 and 106, respectively, to a piezoelectric element support portion 108 that abuts and supports the other end 50b of the piezoelectric element. The support part 108 is spaced apart from the base part so that it will not interfere with the base part even if it is displaced by the piezoelectric element. Output arms 100 and 102 are also tapered when viewed in cross-section in FIG. 2 so that they do not interfere with housing 38 as they pivot within the angular range defined by resilient hinges 96 and 98, respectively. .

Thus, output arms 100 and 102 are substantially 90 angularly disposed about the axis from arm portions 56 and 58, respectively.
``offset, so that the illustrated embodiment has a significantly reduced dimension perpendicular to the axis than if the output arms and arm sections were coplanar and aligned. ing.

The angular deviation between the output arm and the arm portion may be other than 90'', but from the viewpoint of the balance of force, it is most preferable that this angle is substantially 90''. preferable.

The distal ends of the output arms 100 and 102 are bifurcated, and one ends of links 110 and 112 are pivotally connected to the respective distal ends by pivots 114 and 116. The other ends of these links are pivotally connected to each other by a pivot 118 and an output member 120 extending substantially along an axis.
is pivotally connected to one end of the. The output member is pivotally connected to one end of a connecting member 124 by a pivot 122, and the other end of the connecting member is connected to the spool 36 by a stud 126. In the illustrated embodiment, the centers of pivots 118 and 122 intersect axis 34. Also link 1
10 and 112 are inclined toward the side opposite to the piezoelectric element when viewed from one end to the other end, and the line segments connecting the centers of the pivots at both ends of these links form an angle α with respect to the axis 34, respectively.

The yoke-shaped member 80 is thus pivoted by resilient hinges 96 and 98 supported by the retainer 52 through the base portion 86 and the flange portion 82, and is supported by the pair of input arms (
The amount of relative displacement along the axis of the other end 50b of the piezoelectric element 50 is The output arm and 100
and first displacement magnification mechanisms 128 and 130 that expand as they pivot about resilient hinges 96 and 98 at the tips of and 102.
is defined. Let the effective arm length between the elastic hinges 96 and 98 and the elastic hinges 104 and 106 be Xl,
Assuming that the effective arm length of the output arms 100 and 102 is X2, this first displacement magnifying mechanism multiplies the amount of relative displacement of the other end 50b of the piezoelectric element 50 along the axis by X2/X.

The pair of links 110 and 112 are driven at one end by the tips of the output arms 100 and 102 in a direction toward or away from the axis 34, thereby acting as a type of toggle that reciprocates the output member 120 along the axis. A second displacement amplification mechanism 132 is defined by the mechanism, and this second displacement amplification mechanism is
The amount of displacement of the tip of the output member 120 in a direction substantially perpendicular to the axis 34 is expanded by tanα times as a movement along the axis of the output member 120.

A male thread 134 is provided on the outer peripheral surface of the other end of the housing 38, and a nut 136a supporting a cap member 136 is fixed to the other end by being screwed into the male thread 134. The cap member is press-fitted onto the nut so that it can be removed if necessary.

Cap member 136 and flange portion 8 of yoke-shaped member 80
A plate 138 is arranged between the two. This plate has sleeves 140 and 142 on the inner and outer edges, respectively, and the sleeve 142 is connected to the housing 3.
8 and a shoulder 146 provided on the nut 136a, thereby being fixed to the other end of the housing. Further, the sleeve 140 is screwed into a male thread 94 provided on the shaft 92.
It is fixed to the shaft by a nut 148 which is also screwed into the male thread 94.

Thus, the base portion 86 and the flange portion 82) of the yoke-shaped member 80) shaft 92) plate 138, nut 148
, the nut 136a connects the retainer 5 to the housing 38.
This constitutes a fixing means for fixing the retainer 52 to the housing 38 so that the relative position along the axis 34 of the retainer 52 can be adjusted.

Yoke-shaped member 80 is provided with a lead wire passageway 150 with leads 152 and 154 of piezoelectric element 50 extending between the piezoelectric element and arms 56 and 58 and within passageway 150; It passes through a seal 156 affixed to the tip of the shaft 92 and a grommet 158 fixed to the center of the cap member 136 and extends to the outside of the cap member. The piezoelectric element 50 is configured such that a predetermined preload can be applied between the retainer and the support portion 108 by tightening the flange portion of the yoke-shaped member against the flange portions 60 and 62 of the retainer using bolts 84. By controlling the voltage of the control current supplied via the lead wires 152 and 154, the distance between the two ends along the axis 34 is changed.

The housing 38 integrally has a wall 160 protruding inward from the inner peripheral surface at a position adjacent to the second displacement magnifying mechanism 1321, and a flow separator 162 is fixed to the wall by screws 164. .

Flow separator 162 includes windows 166, 168 that receive links 110 and 112 without interfering with them;
Window 1 that receives the connecting member 124 without interfering with it
70, which prevents the hydraulic oil that has flowed into the housing 38 from the passage 42 from directly flowing into the passage 44, thereby allowing the hydraulic oil to flow near the piezoelectric element and cooling it. It is designed to ensure that

In operation, a control device (not shown) applies a control voltage to the piezoelectric element 50 via leads 152 and 154, causing the piezoelectric element to move along the axis 3 in proportion to the applied voltage.
It expands and contracts along 4. The retainer 52 is a yoke-shaped member 80
The flange portion 82) of the shaft 92) is fixed so as not to be displaced relative to the housing 38 via the plate 138, so when the piezoelectric element 50 expands or contracts, the other end 5
0b is displaced relative to the housing along the axis 34, and the displacement is transmitted to the support portion 108.

The displacement along the axis of the support part 108 is caused by the first displacement magnifying mechanism 1
28 and 130, the tip of the output arms 100 and 102 becomes elastic hinge 9.
Pivot around 6 and 98.

Further, the displacement of the tips of the output arms 100 and 102 is multiplied by tanα by the second displacement amplifying mechanism 132 and transmitted to the output member 120 as a displacement along the axis 34, and further to the spool 36 via the connecting member 124 and the stud 126. The flow direction and flow rate of the hydraulic oil in the valve 12 are thereby controlled.

In this case, the position of the spool 36 may be detected by the sensor 46, and feedback control of the actuator may be performed by a control device (not shown) based on an output signal from the sensor.

The illustrated embodiment also facilitates adjustment of the neutral point of the output member 120 and thus the spool 36 of the valve 12. That is, first remove the cap member 136 and then remove the nut 1.
36a and loosen nut 148 slightly to allow plate 138 to rotate about shaft 92. The movement of the plate in the direction along the axis is restricted by the sleeve 42, and the sleeve 140 is screwed into the male thread 94, so when the plate is rotated, the shaft 92 moves along the axis relative to the plate. along the yoke-shaped member 80, retainer 52) second displacement magnification mechanism 1
32 etc. are integrally displaced along the axis relative to the housing 38, thereby adjusting the neutral position of the spool 36 of the valve 12.

In this case, the yoke-shaped member 80, the piezoelectric element 50 and the retainer 5
Since the neutral position can be adjusted without disassembling the yoke-shaped member 80 and the piezoelectric Since the element 50 and the retainer 52 remain integrally assembled, the neutral position can be adjusted without changing the preload of the piezoelectric element.

Additionally, if a piezoelectric element is used for a long period of time, its performance may deteriorate or be damaged due to its own heat generation, so it must be cooled to ensure proper operation over a long period of time. be. According to the illustrated embodiment, a working fluid is introduced into the housing 38 from the return oil line 24 via the passage 42, the working fluid being directed by the flow separator 162 to the area around the piezoelectric element 50, and from the area to the passageway 42. 44 to the return passage 26, which cools the piezoelectric element 50, ensuring proper operation of the actuator over a long period of time, and improving durability.

FIG. 7 is a partial plan cross-sectional view showing a main part of the modified example of the actuator shown in FIGS. 1 to 6. The 7th
In the figures, members that are substantially the same as those shown in FIGS. 1 through 6 are designated by the same reference numerals as those shown in those figures.

In this embodiment, the links 110 and 112 are provided so as to be inclined from one end toward the piezoelectric element 50 when viewed from the other end. Therefore output arms 100 and 102
If the dimensions of all other members except for can be made larger than in the illustrated embodiment, thereby increasing the displacement magnification factor of the first displacement magnification mechanisms 128 and 130. Conversely, the output arms 100 and 1
When setting the effective arm length of 02 to be the same as in the embodiments shown in FIGS. 1 to 6, the length between the retainer support portion 52a and the support portion 108 must be reduced. This allows the actuator to be made even more compact.

FIGS. 8 and 9 are a vertical sectional view and a plan sectional view, respectively, showing another embodiment of the actuator according to the present invention. In these figures, members corresponding to those shown in FIGS. 1 to 6 are given the same reference numerals as those shown in FIGS. 1 to 6.

In this embodiment, the retainer 52 includes a U-shaped main body 172 and a plate 176 integrally fixed to the main body by bolts 174.
The center portion of 6 defines a support portion 52a that abuts and supports one end of the piezoelectric element 50. The retainer 52 is fixed to one end of the valve housing 14 and one end of the housing 38 by clamping the outer periphery of the plate 176 between these housings by bolts 40. Furthermore, a shim 178 is interposed between one end of the piezoelectric element 50, an end of the main body 172 of the retainer, and the support part 52a, and a shim 178 is interposed between the other end of the piezoelectric element 50 and the support part 172 of the yoke-shaped member 80.
A shim 180 is interposed between the shim 8 and the shim 8. This embodiment therefore provides for adjusting the preload on the piezoelectric element and the relative axial position of the body 172 of the retainer 52 and the yoke-shaped member 80 with respect to the housing 38 by appropriately selecting the thickness of these shims. However, this makes it possible to adjust the neutral position of the output member, etc.

FIG. 10 is a partial plan cross-sectional view showing another embodiment of the second displacement amplifying mechanism of the actuator according to the present invention.

In FIG. 10, members corresponding to those shown in FIGS. 1 to 6 are given the same reference numerals as those shown in FIGS. 1 to 6.

In this embodiment, one ends of links 110 and 112 are integrally connected to the tips of output arms 100 and 102 by elastic hinges 182 and 184, respectively, and the other ends of these links are connected to elastic hinges 186 and 188. It is integrally connected to the plate 190 by. plate 19
0 is connected to the output member 120 by a screw 192. In this embodiment as well, the pair of links may be provided at an angle as in the case shown in FIG.

FIG. 11 is a partial plan sectional view showing a modified example of the second displacement amplifying mechanism of the actuator shown in FIGS. 8 and 9. FIG. In FIG. 11, members that are substantially the same as those shown in FIGS. 8 and 9 are given the same reference numerals as those shown in FIGS. 8 and 9. .

In this embodiment, bosses 198 and 20 are attached to the tips of output arms 100 and 102 by screws 194 and 196.
0 is fixed. One end of links 206 and 208 are integrally connected to these bosses by elastic hinges 202 and 204, respectively, and the other ends of these links are connected to plate 2 by elastic hinges 210 and 212, respectively.
14. Plate 210 is the tenth
It is connected to the output member 120 by screws 216 as in the embodiment shown in the figures. Also links 206 and 2
08 are integrally connected to a base member 222 by resilient hinges 218 and 220, respectively. Base member 22
2 is attached to the plate 176 with shims 224 and 226 for neutral position adjustment arranged on both sides of the plate 176.
It is fixed to the plate by being collinear by 74.

Therefore, in this embodiment, links 206 and 208 pivot about elastic hinges 218 and 220, respectively, and the effective arm length between elastic hinges 202 and 204 and elastic hinges 218 and 220 is defined as the Y-th point. , if the effective arm length between the elastic hinges 218 and 220 and the elastic hinges 210 and 212 is Y2, then the output arm 100
The displacement of the tip of 102 is multiplied by 72771 and transmitted to the output member 120 as a displacement in the axial direction.

FIG. 12 is a partial plane cross-sectional view of a modified example of the embodiment shown in FIGS. 1 to 6; FIG. FIG. In these figures, members corresponding to those shown in FIGS. 1 to 6 are given the same reference numerals as those shown in FIGS. 1 to 6.

In this embodiment, a pivot 118 that pivotally connects the other ends of links 110 and 112 to each other and pivotally connects them to output member 120 connects output member 120 to connecting member 124.
The piezoelectric element 50 is located on the opposite side of the pivot shaft 122 that is pivotally connected to the piezoelectric element 50 .

Therefore, according to this embodiment, output arms 100 and 10
The distance between the elastic hinges 96 and 98 of No. 2 and the end of the connecting member 124 on the side connected to the spool is shown in FIGS. 1 to 6 by imaginary lines in FIG. 12. The distance AIL' can be made smaller than the distance AIL' in the embodiment shown in FIG. Furthermore, if this modified example and the modified example shown in FIG. 7 are combined, the actuator can be configured even more compactly.

Although the present invention has been described above in detail with respect to some embodiments and modified examples, the present invention is not limited to these embodiments and modified examples. It will be apparent to those skilled in the art that various other embodiments are possible.

[Brief explanation of the drawing]

1 and 2 are vertical sectional views and plan sectional views, respectively, showing one embodiment of the piezoelectric actuator according to the present invention applied to a hydraulic servo valve, and FIGS. 3 to 5 are sectional views, respectively. Line ■-■ in Figure 1, line IV-IV in Figure 2, line v
6 is a perspective view showing the second displacement magnification mechanism of the embodiment shown in FIGS. 1 to 5, and FIG. FIGS. 8 and 9 are a vertical sectional view and a plan sectional view, respectively, showing another embodiment of the actuator according to the present invention; FIGS. , FIG. 10 is a partial plan cross-sectional view showing another embodiment of the second displacement amplifying mechanism of the actuator according to the present invention, and FIG. 11 is a modified example of the embodiment shown in FIGS. 8 and 9. FIG. 12 is a partial plan cross-sectional view of the ejection port showing another modified example of the actuator shown in FIG. 1;
The figure is a vertical cross-sectional view taken along the line xm-xm in FIG. 12. 10...actuator, 12...valve, 14...
Valve housing, 16...Sleeve, 24.26...
Return oil path, 36...Spool, 42.44...
passage, 46... sensor, 50... piezoelectric element, 52...
・Retainer. 80... Yoke shaped member, 86... Base portion, 92...
...Shaft, 96.98...Elastic hinge, ioo,
102... Output arm, 104.106... Elastic hinge. 108...Support part, 110.112...Link, 1
20... Output member, 124... Connection member, 128.
130... First displacement magnification mechanism, 132... Second displacement magnification mechanism, 136... Cap member, 136a.
...Natsuto, 138...Plate, 140.142.
... Sleeve, 148... Nut, 152.154.
··Lead. 156... Seal, 158... Grommet, 162
...Flow separator, 166.168.170...
·window. 172...Main body, 176...Plate, 178.1
80...Sim, 182.184.186.188...
・Elastic hinge, 198.200...Boss, 202.2
04...Elastic hinge, 206.208...Link,
210.212...Elastic hinge, 214...Plate, 218.220...Elastic hinge, 222...Base, 224.226...Sim patent applicant Toyota Motor Corporation representative
Patent attorney Masa Akashi
Grain barrel 3 Section 50...Piezoelectric element 60.62...Flange part Fig. 5 Fig. 7 Fig. 50 - Pressure @ element 100.102... Output member 110.1 +2 Ri, -2 12〇-Output B material Fig. 6 +1)j 10(,), +02・Output 1"-muN0.112・Link+20-・DenofufujiRsai162 7O-Severator Fig. 10+00 Fig. II Fig. 50...Piezoelectric element TOo, 102 ...Output member +IO, I+2... Link 206.208... Link No. 13 Figure 0z + 00. + 02... Output arm No., 112... Link 120... Output member 124... Connection member (method) Showa April 28, 1963

Claims (7)

[Claims] (1) An output member configured to be connected to a driven member that reciprocates along an axis, a piezoelectric element disposed substantially along the axis, and a retainer that supports one end of the piezoelectric element. and a pair of input arms and a pair of output arms pivotally supported by an elastic hinge supported by the retainer, the input arm having a first displacement amplifying mechanism abutting the other end of the piezoelectric element, and a first displacement amplifying mechanism at one end. a second displacement magnifying mechanism having a pair of links pivotally connected to one end of the output arm, the other end being pivotally connected to each other, and pivotally connected to the output member. (2) The piezoelectric actuator according to claim 1, wherein the output arm extends substantially along the piezoelectric element. (3) In the piezoelectric actuator according to claim 1 or 2, the pair of input arms, the pair of output arms, and the pair of links are each substantially relative to the axis. A piezoelectric actuator characterized by being arranged symmetrically. (4) In the piezoelectric actuator according to any one of claims 1 to 3, the pair of links are connected to the output arm and the output member by a pivot shaft. type actuator. (5) In the piezoelectric actuator according to any one of claims 1 to 3, the pair of links are connected to the output arm and the output member by an elastic hinge. Piezoelectric actuator. (6) The piezoelectric actuator according to claim 5, wherein each of the pair of links is pivotally supported by an elastic hinge supported by the retainer. (7) A piezoelectric actuator according to any one of claims 1 to 6, wherein the output member is pivotally connected to the driven member.