Piezoelectric actuator

Abstract

The utility model aims to provide a piezoelectric actuator. The piezoelectric actuator comprises an actuating piece, a supporting column and a piezoelectric ceramic piece. The piezoelectric ceramic piece is provided with voltage partitions in the circumferential direction with the center point as the axis, and when the piezoelectric ceramic piece is powered on and vibrates, the actuating piece deforms to enable voltage to act on the different voltage partitions. The utility model relates to the technical field of optical element driving, and the piezoelectric actuator is a combined whole, and compared with an electromagnetic actuator, the piezoelectric actuator realizes fewer two-axis moving parts, is simple to assemble, saves space, and has the advantages of high mechanical strength, effectively improved impact resistance, larger driving force and better anti-shake effect.

Description

TECHNICAL FIELD

[0001] The utility model relates to optical element drive technical field, concretely is a piezoelectric actuator. BACKGROUND

[0002] In recent years, optical imaging technology has a wide range of applications in camera modules and other aspects of electronic devices (information equipment) such as smart phones. The current optical imaging system generally uses electromagnetic actuators as driving elements, which has the disadvantages of being susceptible to magnetic field interference and slow response speed. With the development of technology, piezoelectric ceramic materials have been gradually explored. Piezoelectric ceramic ultrasonic motors are a type of energy conversion device that relies on the inverse piezoelectric effect of piezoelectric ceramics to form an ultrasonic frequency elliptical vibration at the stator drive, which drives the mover to move through friction contact. It is suitable for use as a driver in small-sized high-precision mobile optical devices such as mobile phones. However, existing actuators have complex structures, making assembly difficult and lacking in impact resistance, which makes it difficult to generate strong output force. SUMMARY

[0003] To overcome the shortcomings of the prior art, the utility model provides a piezoelectric actuator, which solves the problems of complex structure, difficult assembly and lack of use strength of the existing actuator.

[0004] To achieve the above-mentioned purpose, the utility model realizes the following technical scheme: a piezoelectric actuator, comprising:

[0005] An actuating sheet has a first fixed surface and a second fixed surface formed on opposite sides in the thickness direction; a circular hole is formed in the center of the actuating sheet and extends from the first fixed surface to the second fixed surface;

[0006] A support column is fixed to the first fixed surface;

[0007] A piezoelectric ceramic sheet is fixed to the second fixed surface;

[0008] The piezoelectric ceramic sheet has voltage partitions formed in the circumferential direction with the center point as the axis. When the piezoelectric ceramic sheet is energized and vibrates, the actuating sheet deforms, causing the voltage to act on different voltage partitions.

[0009] Preferably, the voltage partitions include a, b, c, and d partitions that are equally distributed clockwise on the piezoelectric ceramic sheet; or an e partition is formed at the center of the piezoelectric ceramic sheet, and a, b, c, and d partitions are equally distributed clockwise around the e partition.

[0010] Preferably, it further comprises a first support and a second support, which are respectively embedded in the top of the support column and the center of the actuating sheet; the first support and the second support are oppositely arranged along the axis of the support column.

[0011] Preferably, the support column has a hole for embedding the first support;

[0012] The piezoelectric ceramic sheet has a fixing groove in the center, and the second support is embedded in the circular hole of the actuating sheet through the fixing groove.

[0013] Preferably, the hole is a sunken groove formed on the side of the support column away from the actuating sheet.

[0014] Preferably, the hole is a hollow cavity penetrating the support column, and the diameter of the hollow cavity is equal to the diameter of the circular hole.

[0015] Preferably, the fixing groove is circular and has a diameter greater than the diameter of the circular hole.

[0016] Preferably, the first support is a ball or a spherical protrusion, and the second support is a ball.

[0017] Preferably, a pre-pressing member is further provided, which is a leaf spring, and has a certain pre-pressing force between the leaf spring and the second support, so as to simultaneously provide pre-pressing force for the first support and the second support.

[0018] Preferably, the outer diameter of the support column is greater than the diameter of the circular hole and equal to the diameter of the fixing groove. Beneficial effects

[0019] By using the piezoelectric actuator, the piezoelectric actuator is a combined whole, has fewer two-axis movement components, is simple to assemble, saves space, has high mechanical strength, effectively improves impact resistance, has greater driving force, and has better anti-shake effect. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is an exploded structural schematic view of the utility model;

[0021] Figure 2 It is a three-dimensional structural schematic view of the utility model;

[0022] Figure 3 It is a structural schematic view of the hole in the support column being a hollow cavity;

[0023] Figure 4 It is a structural schematic view of the hole in the support column being a sunken groove;

[0024] Figure 5 It is a top view of the utility model;

[0025] Figure 6 It is a bottom view of the utility model;

[0026] Figure 7The structure schematic view of the utility model is installed first support piece and second support piece and pre-presses on the structure schematic view of pre-pressing piece;

[0027] Figure 8 The utility model Figure 7 The bottom view of the utility model is installed second support piece;

[0028] Figure 9 The bottom view of the utility model is installed first support piece;

[0029] Figure 10 The top view of the utility model is installed first support piece;

[0030] Figure 11 The four partition schematic view of piezoelectric ceramic sheet of the utility model;

[0031] Figure 12 The five partition schematic view of piezoelectric ceramic sheet of the utility model;

[0032] Figure 13 The support column is to the X axis direction deviation state diagram of the utility model;

[0033] Figure 14 The support column is to the Y axis direction deviation state diagram of the utility model;

[0034] Figure 15 The support column is in the Z axis direction movement state diagram of the utility model.

[0035] Symbol explanation in drawing

[0036] 1, support column, 2, actuating sheet, 3, piezoelectric ceramic sheet, 4, round hole, 5, hollow cavity, 6, fixed groove, 7, sink groove, 8, first support piece, 9, second support piece, 10, pre-pressing piece. Specific implementation

[0037] The technical scheme in the embodiment of the utility model will be described clearly and completely in the embodiment of the utility model below, obviously, the described embodiment is only a part of the embodiment of the utility model, not all the embodiment. As long as the effect of the utility model can be played, various changes can be made to the implementation scheme.

[0038] The parts in the case are connected in sequence by the personnel in the field, and the specific connection and operation sequence should refer to the following working principle, and the detailed connection means is the technology known in the art, and the following mainly introduces the working principle and process.

[0039] Refer to Figures 1-15 A piezoelectric actuator of the embodiment is described.

[0040] The piezoelectric actuator comprises a support column 1, an actuating sheet 2 and a piezoelectric ceramic sheet 3, which are fixedly connected to form a piezoelectric vibrator, and the whole vibrator is a combined whole, with less components, simple assembly, thick mechanical structure, effectively improved impact resistance and greater output force.

[0041] In the embodiment, first and second fixing surfaces are formed on opposite sides of the actuating sheet 2 in the thickness direction. The support column 1 is fixed with the first fixing surface, and the piezoelectric ceramic sheet 3 is fixed with the second fixing surface. It can be understood that the support column 1, the actuating sheet 2 and the piezoelectric ceramic sheet 3 are sequentially and closely connected from top to bottom. In an implementable manner, the support column 1 and the actuating sheet 2 are integrally formed.

[0042] Further, a circular hole 4 is formed in the center of the actuating sheet 2 and extends in the direction from the first fixing surface to the second fixing surface; the outer diameter of the support column 1 is greater than the diameter of the circular hole 4, so as to ensure that the support column 1 can be connected with the actuating sheet 2 as a whole.

[0043] The piezoelectric ceramic sheet 3 is divided into voltage zones in the circumferential direction with the center point as the axis. The piezoelectric ceramic sheet 3 is electrified to vibrate, the support column 1 deviates from the static position, and the actuating sheet 2 deforms to make the voltage act on different voltage zones when the vibration is amplified.

[0044] Specifically, the voltage zones include a, b, c and d zones which are equally distributed clockwise on the piezoelectric ceramic sheet 3; or an e zone is formed at the center of the piezoelectric ceramic sheet 3, and a, b, c and d zones are equally distributed clockwise around the e zone.

[0045] In an embodiment, the actuating sheet 2 deforms to present three deformation modes, which are swinging around the X-axis direction, swinging around the Y-axis direction and stretching up and down along the Z-axis direction.

[0046] When the piezoelectric ceramic sheet 3 is divided into five zones a, b, c, d and e, the a and c zones are in the same phase, and the b and d zones are in the same phase when swinging around the X-axis direction. Among them, the a and c zones are 0°, and the b and d zones are 180°; at this time, the e zone is 90° or -90° when rising or pressing down, respectively. When swinging around the Y-axis direction, the a and b zones are in the same phase, and the c and d zones are in the same phase. Among them, the e and b zones are 0°, and the c and d zones are 180°; at this time, the a zone is 90° or -90° when rising or pressing down, respectively.

[0047] When the piezoelectric ceramic sheet 3 is divided into four regions a, b, c, d, when swinging around the X-axis direction and stretching up and down along the Z-axis direction at the same time, the a and c regions are the same phase, and the b and d regions are the same phase. Among them, the a and c regions are 0° or 90°, and the b and d regions are 90° or 0°; when swinging around the Y-axis direction and stretching up and down along the Z-axis direction at the same time, the a and b regions are the same phase, and the c and d regions are the same phase. Among them, the a and b regions are 0° or 90°, and the c and d regions are 90° or 0°.

[0048] The advantage of the four regions is that the control port is less, and the control circuit is simpler than the five regions. The advantage of the five regions is that the size ratio of the push-pull modal piezoelectric region and the swing piezoelectric region can be adjusted to achieve the desired elliptical trajectory.

[0049] The partition rule is explained: Up refers to the push-pull modal voltage, and Us refers to the swing modal voltage. In the state of the actuator sheet 2 deformation swinging around the X-axis direction and swinging around the X-axis direction and stretching up and down along the Z-axis direction, the push-pull modal voltage Up acts on the a, b, c, d regions, the swing modal voltage Us acts on the a, c regions, and -Us acts on the b, d regions (when reversed, the swing modal voltage -Us acts on the a, c regions, and Us acts on the b, d regions). Then Ua=Uc=Up+Us; Ub=Ud=Up-Us, after pushing, Ua / Uc and Ub / Ud are 90 degrees out of phase.

[0050] The piezoelectric actuator further comprises a first support 8 and a second support 9, and the first support 8 and the second support 9 are respectively embedded in the top of the support column 1 and the center of the actuator sheet 2; the first support 8 and the second support 9 are oppositely arranged along the axis of the support column 1.

[0051] In this embodiment, a hole is opened in the support column 1 for embedding the first support 8.

[0052] The hole opened in the support column 1 has two formation forms, one of which is a sink 7, formed on the side of the support column 1 away from the actuator sheet 2. The second is a hollow cavity 5 that penetrates the support column 1, and the diameter of the hollow cavity 5 is equal to the diameter of the circular hole 4.

[0053] A fixing groove 6 is opened in the center of the piezoelectric ceramic sheet 3, and the second support 9 is embedded in the circular hole 4 on the actuator sheet 2 after passing through the fixing groove 6.

[0054] Further, the fixing groove 6 is circular to ensure that the second support 9 can be fitted without dead angles. The diameter of the fixing groove 6 is greater than the diameter of the circular hole 4 to prevent the second support 9 from being embedded into the circular hole 4, and to enable the top arc portion of the second support 9 to be accommodated into the circular hole 4.

[0055] It should be noted that the outer diameter of the support column 1 is equal to the diameter of the fixing groove 6.

[0056] In the embodiment, the first support 8 is a ball or a spherical protrusion, and the second support 9 is a ball.

[0057] The piezoelectric actuator is further provided with a pre-pressing member 10, which is a leaf spring and has a certain pre-pressing force with the second support 9, so as to simultaneously provide the first support 8 and the second support 9 with pre-pressing force.

[0058] Although the embodiments of the present application have been shown and described, it should be understood by those ordinary skilled in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A piezoelectric actuator, characterized by, It comprises: an actuating sheet (2) having a first fixed surface and a second fixed surface formed on opposite sides in the thickness direction; a circular hole (4) formed in the center of the actuating sheet (2) and extending from the first fixed surface to the second fixed surface; a support column (1) fixed with the first fixed surface; a piezoelectric ceramic sheet (3) fixed with the second fixed surface; the piezoelectric ceramic sheet (3) has voltage division zones formed in the circumferential direction with the center point as the axis, and when the piezoelectric ceramic sheet (3) is electrified and vibrates, the actuating sheet (2) deforms to make the voltage act on different voltage division zones.

2. A piezoelectric actuator according to claim 1, characterised in that: The voltage division zones include a, b, c, and d zones distributed equidistantly clockwise on the piezoelectric ceramic sheet (3); or an e zone formed at the center of the piezoelectric ceramic sheet (3), and a, b, c, and d zones distributed equidistantly clockwise around the e zone.

3. A piezoelectric actuator according to claim 1, wherein: It also comprises a first support (8) and a second support (9) embedded in the top of the support column (1) and the center of the actuating sheet (2) respectively; the first support (8) and the second support (9) are oppositely arranged along the axis of the support column (1).

4. A piezoelectric actuator according to claim 3, wherein: The support column (1) has a hole for embedding the first support (8); the center of the piezoelectric ceramic sheet (3) has a fixed groove (6), and the second support (9) is embedded in the circular hole (4) on the actuating sheet (2) after passing through the fixed groove (6).

5. A piezoelectric actuator according to claim 4, wherein: The hole is a sunken groove (7) formed on the side of the support column (1) away from the actuating sheet (2).

6. A piezoelectric actuator according to claim 4, wherein: The hole is a hollow cavity (5) passing through the support column (1), and the diameter of the hollow cavity (5) is equal to the diameter of the circular hole (4).

7. A piezoelectric actuator according to claim 4, wherein: The fixed groove (6) is circular with a diameter greater than that of the circular hole (4).

8. A piezoelectric actuator according to claim 3, wherein: The first support (8) is a ball or a spherical protrusion, and the second support (9) is a ball.

9. A piezoelectric actuator according to claim 3, wherein: A pre-pressing member (10) is also provided, which is a leaf spring with a certain pre-pressing force between the leaf spring and the second support (9), which can provide pre-pressing force for the first support (8) and the second support (9) at the same time.

10. A piezoelectric actuator according to claim 1, wherein: The outer diameter of the support column (1) is greater than the diameter of the circular hole (4) and equal to the diameter of the fixed groove (6).

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