Piezoelectric actuator

Abstract

A piezoelectric actuator comprises a lever structure, a moving part, a first piezoelectric ceramic and a second piezoelectric ceramic, and on a projection plane in the vertical direction of the lever structure, the projection of the first piezoelectric ceramic and the projection of the second piezoelectric ceramic are located on the two sides of the projection of a fulcrum of the lever structure respectively. During working, the first piezoelectric ceramic applies a first acting force to enable the moving part to move by a first distance. And / or the second piezoelectric ceramic applies a second moment to the other end of the lever structure, one end of the lever structure generates a first moment, and the first moment enables the moving part to move by a second distance. The two piezoelectric ceramics are arranged at the two ends of the lever structure, and through the amplification principle of the lever structure (that is, small displacement is applied to one end of the lever, and larger displacement can be generated at the other end), the displacement is increased, and meanwhile, the two piezoelectric ceramics are matched for use, so that the overall precision of the piezoelectric actuator can be greatly improved.

Description

Technical Field

[0001] The utility model relates to the technical field of actuators, and particularly relates to a piezoelectric actuator. Background Art

[0002] The name of the piezoelectric actuator is derived from the combination of its driving power source and its function. "Piezoelectric" refers to its driving source, that is, using PZT piezoelectric ceramics as the driving source to generate motion; while "actuator" is its function, and its moving end can produce an actuating effect, that is, it is used to carry an object for micro-displacement adjustment. The piezoelectric actuator applies a pre-tightening force to the PZT piezoelectric ceramics and is encapsulated in a metal shell. At the same time, it is equipped with mechanical fixed installation interfaces and load installation interfaces.

[0003] Under normal circumstances, the piezoelectric actuator can drive the load for micro-displacement adjustment by itself. The threaded hole or rod at its moving end can be directly connected to the load. Of course, it can also drive the mechanical structure, and then the mechanical structure completes the motion adjustment.

[0004] The authorized announcement number CN217824771U discloses a piezoelectric ceramic actuator structure for reducing internal stress, and specifically discloses the following content: including a metal outer shell 1 and a piezoelectric ceramic main body 2. One end of the upper part of the metal outer shell 1 is fixedly connected with a locking nut 5. A moving part 6 is arranged at the center of the locking nut 5. One end of the moving part 6 close to the piezoelectric ceramic main body 2 is fixedly connected with a connecting seat 3. Two pre-tightening discs 4 are arranged above the inside of the metal outer shell 1. One end of the moving part 6 away from the connecting seat 3 passes through the two pre-tightening discs 4 and the locking nut 5 and is slidably connected with the locking nut 5. The positions of the two pre-tightening discs 4 are between the locking nut 5 and the connecting seat 3. The two pre-tightening discs 4 are symmetrically attached to each other to provide a pre-tightening force. One end of the metal outer shell 1 away from the locking nut 5 is fixedly connected with a base 10 for power connection. Conical concave grooves 7 are respectively opened at the centers of the end faces of the connecting seat 3 and the base 10 close to the piezoelectric ceramic main body 2. One end center of the piezoelectric ceramic main body 2 close to the connecting seat 3 is fixedly connected with an upper hemispherical shaft 8. One end center of the piezoelectric ceramic main body 2 close to the base 10 is fixedly connected with a lower hemispherical shaft 9. The upper hemispherical shaft 8 and the lower hemispherical shaft 9 are respectively movably connected with the corresponding conical concave grooves 7. By using the non-fixed contact method between the hemispherical surface of the hemispherical shaft and the conical concave groove 7, the piezoelectric ceramic main body 2 can be combined with the actuator fixing part, and the output center of the piezoelectric ceramic main body 2 can be fixed at the geometric center of the metal fastener and the moving part 6.

[0005] When the above-mentioned existing document is in motion, it can reduce the internal stress caused by the longitudinal shear force, thereby delaying the aging of the ceramic. However, there are the following problems: Since piezoelectric actuators are often used in precision instruments such as medical equipment, aerospace equipment, and electronic equipment, how to make the piezoelectric actuator have high precision is a key issue. The above-mentioned existing document has a certain degree of precision. However, due to the limitations of a single piezoelectric ceramic, it cannot achieve a large displacement of the moving part, and the precision cannot meet the requirements of the above-mentioned precision instruments. Therefore, it is necessary to invent a piezoelectric actuator with high precision. Summary of the Utility Model

[0006] Aiming at the problems existing in the above-mentioned prior art, the purpose of the present utility model is to provide a piezoelectric actuator, which can amplify the displacement of the moving part while greatly improving the precision to meet the requirements of various precision instruments.

[0007] In order to achieve the above purpose, the technical solution of the present utility model is:

[0008] A piezoelectric actuator includes a lever structure, a moving part, a first piezoelectric ceramic, and a second piezoelectric ceramic. In the projection plane perpendicular to the lever structure, the projections of the first piezoelectric ceramic and the second piezoelectric ceramic are respectively located on both sides of the projection of the fulcrum of the lever structure; during operation, the first piezoelectric ceramic applies a first acting force to move the moving part by a first distance; and / or the second piezoelectric ceramic applies a second moment to the other end of the lever structure, and a first moment is generated at one end of the lever structure, and the first moment makes the moving part move by a second distance.

[0009] Further, the lever structure includes a lever and the fulcrum, and the fulcrum is arranged between the two ends of the lever.

[0010] Further, the fulcrum is a convex structure arranged on the lever.

[0011] Further, a first through hole is arranged on the lever, the central axis of the first through hole is perpendicular to the projection plane perpendicular to the lever, the fulcrum is arranged in the first through hole and is in clearance fit with the first through hole.

[0012] Further, a second through hole is arranged on the fulcrum, the central axis of the second through hole is parallel to the projection plane perpendicular to the lever, the lever is arranged in the second through hole and is in clearance fit with the second through hole.

[0013] Further, a third through hole is arranged on the side surface of the lever, the central axis of the third through hole is parallel to the projection plane perpendicular to the lever, the fulcrum is arranged in the third through hole and is connected with the third through hole in a mating manner.

[0014] Further, the fulcrum is a first concave structure provided on the surface of the lever; further includes a first fixed convex portion, and one end of the first fixed convex portion abuts against the first concave structure.

[0015] Further, the fulcrum is a second concave structure provided on the side surface of the lever; further includes a second fixed convex portion, and one end of the second fixed convex portion is arranged in the second concave structure and is in clearance fit with the second concave structure.

[0016] Further, the first piezoelectric ceramic and the second piezoelectric ceramic are arranged on one surface of the lever at a predetermined distance.

[0017] Further, the fulcrum is arranged on the other surface of the lever.

[0018] Further, the fulcrum, the first piezoelectric ceramic and the second piezoelectric ceramic are arranged on one surface of the lever.

[0019] Further, when the second piezoelectric ceramic applies the second moment to the other end of the lever, the position where the lever contacts the second piezoelectric ceramic is a second concave portion; when the first piezoelectric ceramic applies the first moment to one end of the lever, the position where the lever contacts the first piezoelectric ceramic is a first concave portion.

[0020] Further, it further includes a housing, and the lever structure, the first piezoelectric ceramic and the second piezoelectric ceramic are arranged inside the housing.

[0021] Further, a first pressing block and a second pressing block are further arranged inside the housing. The first pressing block is located between the first piezoelectric ceramic and an inner wall of the housing, and the second pressing block is located between the second piezoelectric ceramic and an inner wall of the housing; the first pressing block is provided with a fourth through hole, and one end of the moving member is arranged in the fourth through hole and contacts the first piezoelectric ceramic, and the other end of the moving member extends out of the housing; the second pressing block is provided with a fifth concave portion, and the fifth concave portion contacts the second piezoelectric ceramic.

[0022] Further, a third pressing block is further arranged inside the housing, and the third pressing block is located between the first piezoelectric ceramic and the second piezoelectric ceramic.

[0023] The beneficial effects of the present utility model are as follows:

[0024] In this piezoelectric actuator, two piezoelectric ceramics are arranged at both ends of a lever structure. Through the amplification principle of the lever structure (that is, a small displacement is applied at one end of the lever, and a larger displacement can be generated at the other end), while achieving an increase in displacement, the displacement superposition method of the two piezoelectric ceramics can greatly improve the overall precision of the piezoelectric actuator. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic perspective view of an embodiment of the present utility model;

[0026] Figure 2 is Figure 1 exploded structural view of;

[0027] Figure 3 is Figure 1 a schematic plan view of the housing and the internal structure thereof in;

[0028] Figure 4 is Figure 1 a schematic structural view of the lever structure in;

[0029] Figure 5 is a schematic plan view of the housing and the internal structure thereof in another embodiment of the present utility model;

[0030] Figure 6 is Figure 5 a schematic sectional view of the lever and the fulcrum in;

[0031] Figure 7 is a schematic plan view of the housing and the internal structure thereof in the third embodiment of the present utility model;

[0032] Figure 8 is Figure 7 a schematic perspective view of the lever and the fulcrum in;

[0033] Figure 9 is a schematic plan view of the housing and the internal structure thereof in the fourth embodiment of the present utility model;

[0034] Figure 10 is a schematic plan view of the housing and the internal structure thereof in the fifth embodiment of the present utility model;

[0035] Figure 11 is Figure 10 a schematic plan view of the lever and the fulcrum in;

[0036] Figure 12 is a schematic plan view of the housing and the internal structure thereof in the sixth embodiment of the present utility model;

[0037] Figure 13 is Figure 12 exploded structural view of;

[0038] Figure 14 is Figure 12 A sectional view schematic diagram of the middle lever and the fulcrum.

[0039] Reference numerals

[0040] 100, piezoelectric actuator; 1, lever structure; 11, lever; 111, first recess; 112, second recess; 12, fulcrum; 121, convex structure; 122, second through hole; 123, first concave structure; 124, second concave structure; 13, first through hole; 14, third through hole; 2, moving member; 21, first cylinder; 22, second cylinder; 3, first piezoelectric ceramic; 31, first hemispherical structure; 32, second hemispherical structure; 4, second piezoelectric ceramic; 41, third hemispherical structure; 42, fourth hemispherical structure; 5, housing; 51, first pressing block; 511, fourth through hole; 52, second pressing block; 521, fifth recess; 53, third pressing block; 54, fourth pressing block; 541, sixth recess; 55, fifth through hole; 6, elastic member; 7, first fixed convex portion; 8, second fixed convex portion; 9, cover body. Detailed implementation manners

[0041] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "top surface", "bottom surface", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the indicated position or element must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present utility model.

[0042] In addition, if there are terms "first" and "second", they are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, the meaning of "several" is two or more, unless otherwise clearly and specifically defined.

[0043] In the present utility model, unless otherwise clearly specified and defined, if there are terms "assembled", "connected", "joined", they should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may also be a mechanical connection; it may be directly connected, or connected through an intermediate medium, and it may be internally connected and communicated between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0044] The following further elaborates on the utility model in conjunction with the accompanying drawings and specific embodiments. The following description is merely exemplary and does not limit the protection scope of the utility model.

[0045] Please refer to Figures 1 - 4 , a piezoelectric actuator 100, comprising a lever structure 1, a moving member 2, a first piezoelectric ceramic 3, and a second piezoelectric ceramic 4. In the projection plane perpendicular to the lever structure 1, the projections of the first piezoelectric ceramic 3 and the second piezoelectric ceramic 4 are respectively located on both sides of the projection of the fulcrum 12 of the lever structure 1. During operation, the first piezoelectric ceramic 3 applies a first acting force to cause the moving member 2 to move a first distance, and / or the second piezoelectric ceramic 4 applies a second moment to the other end of the lever structure 1, and a first moment is generated at one end of the lever structure 1, and the first moment causes the moving member 2 to move a second distance.

[0046] In this embodiment, the lever structure 1 includes a lever 11 and a fulcrum 12. The fulcrum 12 is disposed between the two ends of the lever 11. In this embodiment, the fulcrum 12 is disposed closer to the second piezoelectric ceramic 4. Specifically, the fulcrum 12 is a convex structure 121 disposed on the lever 11 (in detail, the fulcrum 12 is disposed on the other surface of the lever 11), and the convex structure 121 is integrally semi-cylindrical.

[0047] The first piezoelectric ceramic 3 and the second piezoelectric ceramic 4 are disposed on one surface of the lever 11 at a predetermined distance interval (specifically, the first piezoelectric ceramic 3 and the second piezoelectric ceramic 4 are disposed on the top surface of the lever 11, and the fulcrum 12 is disposed on the bottom surface of the lever 11). In this embodiment, the two ends of the first piezoelectric ceramic 3 are provided with a first hemispherical structure 31 and a second hemispherical structure 32, and the two ends of the second piezoelectric ceramic 4 are provided with a third hemispherical structure 41 and a fourth hemispherical structure 42.

[0048] Specifically, when a voltage is applied to the first piezoelectric ceramic 3 to deform it, and the first hemispherical structure 31 contacts one end of the lever 11 (that is, when the first piezoelectric ceramic 3 applies a first torque to the lever 11), the position where the lever 11 contacts the first hemispherical structure 31 of the first piezoelectric ceramic 3 is the first recessed portion 111, and the degree of concavity of the first recessed portion 111 matches the curvature of the first hemispherical structure 31. Similarly, when a voltage is applied to the second piezoelectric ceramic 4 to deform it, and the third hemispherical structure 41 contacts the other end of the lever 11 (that is, when the second piezoelectric ceramic 4 applies a second torque to the lever 11), the position where the lever 11 contacts the third hemispherical structure 41 of the second piezoelectric ceramic 4 is the second recessed portion 112, and the degree of concavity of the second recessed portion 112 matches the curvature of the third hemispherical structure 41. The two ends of the first piezoelectric ceramic 3 and the second piezoelectric ceramic 4 are respectively set to be semi-spherical. The advantages of this are: 1. When the end face of the hemispherical first piezoelectric ceramic 3 (including the end face of the second piezoelectric ceramic 4) contacts the concave first recessed portion 111 (including the second recessed portion 112), the contact surface is a point. When subjected to force, this contact form can automatically adjust the contact position so that the force is evenly distributed along the axis of the piezoelectric ceramic. 2. It can automatically compensate for slight position deviations caused by installation errors, manufacturing tolerances or external interference, reduce the generation of eccentric stress, and thus protect the piezoelectric ceramics from being damaged by non-axial forces. 3. The point contact characteristics of the hemisphere and the concave surface make the contact area very small, thereby reducing friction. Lower friction helps reduce wear, especially in dynamic environments, and can effectively improve the reliability and durability of the system. 4. Since the spherical surface can be adaptively contacted, precise alignment is not required during installation, which simplifies the assembly process.

[0049] In this embodiment, on the projection plane in the vertical direction of the lever 11, the projection of the fulcrum 12 is closer to the projection of the second piezoelectric ceramic 4 than the projection of the first piezoelectric ceramic 3. Specifically, the distance from the projection of the fulcrum 12 to the projection of the first piezoelectric ceramic 3 is set to L, and then the distance from the projection of the fulcrum 12 to the projection of the second piezoelectric ceramic 4 is at least 2.6L, which is just an example, and the present invention is not limited thereto.

[0050] In this embodiment, a housing 5 is further included, and the lever structure 1 (including the lever 11 and the fulcrum 12 ), the moving member 2 , the first piezoelectric ceramic 3 and the second piezoelectric ceramic 4 are all arranged inside the housing 5 .

[0051] A first pressing block 51 and a second pressing block 52 are further disposed inside the housing 5 , wherein the first pressing block 51 is located between the first piezoelectric ceramic 3 and an inner wall of the housing 5 , and the second pressing block 52 is located between the second piezoelectric ceramic 4 and an inner wall of the housing 5 .

[0052] On one side of the second pressing block 52 opposite to the second piezoelectric ceramic 4, a fifth recess 521 is provided. The fifth recess 521 is in contact with the fourth hemispherical structure 42 of the second piezoelectric ceramic 4, and the degree of depression of the fifth recess 521 matches the radian of the fourth hemispherical structure 42 of the second piezoelectric ceramic 4. The first pressing block 51 is provided with a fourth through hole 511. One end of the moving member 2 is disposed in the fourth through hole 511 and is in contact with the second hemispherical structure 32 of the first piezoelectric ceramic 3, and the other end of the moving member 2 extends out of the housing 5.

[0053] Specifically, in this embodiment, the moving member 2 is divided into upper and lower ends, and its upper and lower ends are composed of a first cylinder 21 and a second cylinder 22 with different diameters. The diameter ratio of the first cylinder 21 to the second cylinder 22 is at least 1:2. This is only an example, and the present invention is not limited thereto. A part of the first cylinder 21 and the entire second cylinder 22 are disposed in the fourth through hole 511, and the bottom surface of the second cylinder 22 is in contact with the second hemispherical structure 32 of the first piezoelectric ceramic 3. The remaining part of the first cylinder 21 extends out of the housing 5.

[0054] In this embodiment, the moving member 2 will move under the action of the first piezoelectric ceramic 3 and the second piezoelectric ceramic 4. However, no matter how far the moving member 2 moves, it will eventually be in a static state. In the static state of the moving member 2, the first piezoelectric ceramic 3, the lever 11, the fulcrum 12, and the second piezoelectric ceramic 4 are in a balanced state. At this time, the product of the power and the power arm is equal to the product of the resistance and the resistance arm (i.e., the second moment is equal to the first moment). In this embodiment, the power is the second force applied by the second piezoelectric ceramic 4 to the lever 11, the power arm is the distance from the second piezoelectric ceramic 4 to the fulcrum 12 (equivalent to L above), the resistance is the first force applied by the first piezoelectric ceramic 3 to the lever 11, and the resistance arm is the distance from the first piezoelectric ceramic 3 to the fulcrum 12 (equivalent to 2.6L above). That is to say, the fulcrum 12 is closer to the second piezoelectric ceramic 4. Therefore, in order to maintain the moment balance, the first force applied by the first piezoelectric ceramic 3 must be smaller than the second force applied by the second piezoelectric ceramic 4 to satisfy the moment balance of the lever 11 principle. According to the energy conservation in the lever 11 system, in an ideal state, the work done at the input end (the second piezoelectric ceramic 4) is equal to the work done at the output end (the first piezoelectric ceramic 3). Work is equal to the product of force and displacement, that is, the work W at the input end in =F in ×d in , the work W at the output end out =F out ×d out , and W in =W out . Where F in is the second force, d in is the displacement of the second piezoelectric ceramic 4, Fout is the first acting force, d out is the displacement of the first piezoelectric ceramic 3. From the above, F in >F out , then d in <d out , that is, the displacement of the second piezoelectric ceramic 4 located at the input end will be amplified by the lever 11 and transmitted to the first piezoelectric ceramic 3 at the output end, causing the moving member 2 to move a second distance. The first piezoelectric ceramic deforms directly under the voltage, causing the moving member 2 to move a first distance. Therefore, the overall moving distance of the moving member 2 is the superposition of the first distance and the second distance. Of course, the fulcrum 12 can also be set near the center of the lever 11 or at one end of the lever 11 close to the first piezoelectric ceramic 3, which is not limited here.

[0055] In this embodiment, a third pressing block 53 is further provided inside the housing 5. The two sides of the third pressing block 53 are respectively in contact with the first pressing block 51 and the second pressing block 52, and the third pressing block 53 is located between the first piezoelectric ceramic 3 and the second piezoelectric ceramic 4.

[0056] In this embodiment, a fourth pressing block 54 is further provided inside the housing 5. The bottom surface of the fourth pressing block 54 abuts against another inner wall of the housing 5 (this another inner wall is oppositely arranged with the above-mentioned one inner wall). A sixth recess 541 is provided on the top surface of the fourth pressing block 54. The sixth recess 541 is in contact with the convex structure 121, and the degree of depression of the sixth recess 541 matches the radian of the convex structure 121.

[0057] In this embodiment, a plurality of fifth through holes 55 are provided in the housing 5 for the following reasons: First, the piezoelectric actuator 100 will generate a certain amount of heat during operation. If the heat cannot be dissipated in time, it may affect the performance of the first piezoelectric ceramic 3 and the second piezoelectric ceramic 4, and even cause the failure of the actuator. Opening the fifth through holes 55 can promote air flow, thereby improving the heat dissipation efficiency. Second, opening the fifth through holes 55 can reduce the weight of the housing 5 of the piezoelectric actuator 100, thereby reducing the mass of the entire device. This is particularly important in fields such as precision instruments where strict requirements are imposed on weight. Third, when the piezoelectric actuator 100 is operating, stress may be generated inside, especially in the case of high-frequency vibration and large displacement. Opening the fifth through holes 55 can help release these stresses and prevent the housing 5 from cracking or being damaged due to stress concentration.

[0058] In this embodiment, the piezoelectric actuator 100 further includes a cover body 9. Covering the cover body 9 on the housing 5 can achieve the protection effect on the components provided inside the housing 5.

[0059] The working principle of the present invention will be introduced below for better understanding of the present invention:

[0060] One end of the second piezoelectric ceramic 4 disposed on the lever 11 is the input end, and the other end of the first piezoelectric ceramic 3 disposed on the lever 11 is the output end. Voltage is applied to the second piezoelectric ceramic 4 and the first piezoelectric ceramic 3. The second piezoelectric ceramic 4 elongates as a whole, generating a second distance. The second distance is amplified and transmitted to the output end through the lever 11. The first piezoelectric ceramic 3 is located at the output end, and the first distance generated by its own deformation directly affects the total distance at the output end. At this time, the total distance is the sum of the first distance and the second distance, so that the moving distance of the moving member 2 can be accurately controlled.

[0061] In the present utility model, the first piezoelectric ceramic 3 and the second piezoelectric ceramic 4 are disposed at both ends of the lever 11. The moving member 2 is disposed on the first piezoelectric ceramic 3, and the fulcrum 12 is close to the second piezoelectric ceramic 4. At this time, the second piezoelectric ceramic 4 serves as the output end, and the first piezoelectric ceramic 3 serves as the output end. Voltage is applied to the second piezoelectric ceramic 4 and the first piezoelectric ceramic 4 to cause them to deform and generate a second distance. The second distance is amplified and transmitted to the output end through the lever 11. Then, combined with the deformation of the first piezoelectric ceramic 3 itself to generate a first distance, the sum of the first distance and the second distance is the displacement distance of the moving member 2. In this way, the displacement amount of the moving member 2 can be accurately controlled.

[0062] Please refer to Figures 5 - 6 The present utility model further includes a second embodiment. The difference between the second embodiment and the first embodiment is that the structure of the fulcrum 12 is changed. Its specific structure is as follows:

[0063] In this embodiment, a first through hole 13 is provided on the surface of the lever 11. The central axis of the first through hole 13 is perpendicular to the projection plane in the vertical direction of the lever 11. The convex structure 121 of the fulcrum 12 is disposed in the first through hole 13. The lateral area of the convex structure 121 is slightly larger than the opening of the first through hole 13 to prevent the convex structure 121 from detaching from the first through hole 13. Specifically, the size of the opening of the first through hole 13 is larger than the size of the convex structure 121 (the specific size is not limited, as long as it can prevent the fulcrum 12 from detaching from the lever 11), and the overall size of the first through hole 13 is larger than the overall size of the fulcrum 12, so that the lever 11 can swing.

[0064] Please refer to Figure 6, specifically, when viewed from a vertical cross-section, in this embodiment, the first end of the convex structure 121 is set to be circular, the second end of the convex structure 121 is set to be strip-shaped, and the first through-hole 13 is also circular. The diameter of the entire first through-hole 13 is slightly larger than the diameter of the first end of the convex structure 121. The diameter of the opening of the first through-hole 13 is larger than the diameter of the second end of the convex structure 121, and the diameter of the opening of the first through-hole 13 is smaller than the diameter of the first end of the convex structure 121. Therefore, while the lever 11 can swing around the convex structure 121, the lever 11 will not break away from the convex structure 121.

[0065] Preferably, an elastic member 6 is further provided, and one end of the elastic member 6 abuts against the inner wall of the housing 5. Specifically, in this embodiment, the elastic member 6 and the fulcrum 12 are located in the same vertical plane. Of course, the elastic member 6 can be in the same vertical plane as the second piezoelectric ceramic 4, the elastic member 6 can also be in the same vertical plane as the first piezoelectric ceramic 3, or there are two elastic members 6, and the two elastic members 6 are respectively in the same vertical plane as the first piezoelectric ceramic 3 and the second piezoelectric ceramic 4. The function of setting the elastic member 6 is to further prevent the lever 11 from detaching from the fulcrum 12, and the number and position of the elastic member 6 are not limited here.

[0066] Other technical features and technical effects are the same as those in the first embodiment, and will not be elaborated here.

[0067] Please refer to Figures 7 - 8 , the present invention further includes a third embodiment. The difference between the third embodiment and the first embodiment is that the structure of the fulcrum 12 is changed. Its specific structure is as follows:

[0068] In this embodiment, the fulcrum 12 is arranged inside the housing 5, and a second through-hole 122 is arranged on the fulcrum 12. The central axis of the second through-hole 122 is parallel to the projection plane in the vertical direction of the lever 11. The lever 11 is arranged in the second through-hole 122 and is in clearance fit with the second through-hole 122. Specifically, the size of the second through-hole 122 is larger than the size of the lever 11 to facilitate sufficient space for the lever 11 to swing. The advantage of this design of inserting the lever 11 into the second through-hole 122 is that even if one surface of the lever 11 is deformed by the first piezoelectric ceramic 3 or the second piezoelectric ceramic 4, and a first downward force and a second downward force are respectively applied to the lever 11, the bottom surface of the lever 11 will always receive an upward reaction force applied by the bottom wall of the second through-hole 122. This reaction force can offset the first force and the second force, so that the lever 11 will not break away from the first piezoelectric ceramic 3 or the second piezoelectric ceramic 4.

[0069] By directly setting the second through hole 122 on the fulcrum 12 and setting the lever 11 in the second through hole 122, the mass of the entire piezoelectric actuator 100 can be reduced to improve the response time of each component, which is very important in precision equipment.

[0070] Other technical features and technical effects are consistent with those of Example 1 and will not be elaborated here.

[0071] Please refer to Figure 9 The present utility model also includes a fourth embodiment, and the difference between the fourth embodiment and the first embodiment is that the structure of the fulcrum 12 is changed. Its specific structure is:

[0072] The fulcrum 12 is a first concave structure 123 arranged on the surface of the lever 11. In the present embodiment, the first concave structure 123 is arranged on the bottom surface of the lever 11, while the first piezoelectric ceramic 3 and the second piezoelectric ceramic 4 are arranged on the top surface of the lever 11. The piezoelectric actuator 100 further includes a first fixed protrusion 7, which abuts against the first concave structure 123. In the present embodiment, the top of the first fixed protrusion 7 has a certain curvature, which is smaller than the concave curvature of the first concave structure 123. Of course, the curvature of the top of the first fixed protrusion 7 can also be equal to the concave curvature of the first concave structure 123 (the top of the first fixed protrusion 7 basically coincides with the concave position of the first concave structure 123). When the first piezoelectric ceramic 3 or the second piezoelectric ceramic 4 is deformed and applies the first force and the second force to the lever 11 respectively, the first fixed protrusion 7 can support the first concave structure 123, so that the first concave structure 123 can move the lever 11 under the action of the first fixed protrusion 7, thereby preventing the lever 11 from separating from the first piezoelectric ceramic 3 or the second piezoelectric ceramic 4.

[0073] Other technical features and technical effects are consistent with those of Example 1 and will not be elaborated here.

[0074] Please refer to Figures 10 - 11 The utility model also includes a fifth embodiment, which differs from the first embodiment in that the structure of the fulcrum 12 is changed. The specific structure is as follows:

[0075] In this embodiment, a third through hole 14 is provided on the side of the lever 11, the central axis of the third through hole 14 is parallel to the projection plane of the lever 11 in the vertical direction, the fulcrum 12 is provided in the third through hole 14, and one end of the fulcrum 12 is fixedly provided inside the housing 5 (equivalent to the fulcrum 12 nailing the lever 11 inside the housing 5). Specifically, the diameter of the top of the fulcrum 12 is larger than the diameter of the third through hole 14 (which can effectively prevent the fulcrum 12 from being separated from the lever 11), the diameter of the rod of the fulcrum 12 is slightly smaller than the diameter of the third through hole 14, and the length of the rod of the fulcrum 12 is larger than the depth of the third through hole 14. The rod of the fulcrum 12 is passed through the third through hole 14 and provided inside the housing 5, so that the lever 11 can rotate around the fulcrum 12. When the first piezoelectric ceramic 3 or the second piezoelectric ceramic 4 is deformed and applies the first force and the second force to the lever 11 respectively, since the lever 11 is fixed in position by the fulcrum 12, the lever 11 will not separate from the first piezoelectric ceramic 3 or the second piezoelectric ceramic 4 even if it is subjected to the first force and the second force in the same direction.

[0076] Other technical features and technical effects are consistent with those of Example 1 and will not be elaborated here.

[0077] Please refer to Figures 12 - 14 The utility model also includes a sixth embodiment, which differs from the fifth embodiment in that the structure of the fulcrum 12 is changed. Its specific structure is:

[0078] The fulcrum 12 is a second concave structure 124 disposed on the side of the lever 11. A second fixed protrusion 8 is disposed inside the housing 5. The second fixed protrusion 8 cooperates with the second concave structure 124 so that the lever 11 can rotate around the second concave structure 124. When the first piezoelectric ceramic 3 or the second piezoelectric ceramic 4 is deformed and applies a first force and a second force to the lever 11, respectively, the lever 11 is fixed in position by the second fixed protrusion 8. Therefore, even if the lever 11 is subjected to the first force and the second force in the same direction, it will not be separated from the first piezoelectric ceramic 3 or the second piezoelectric ceramic 4.

[0079] In this embodiment, the first fixed protrusion 8 is block-shaped, and the vertical cross-section of the second concave structure 124 is square. Preferably, the first fixed protrusion 8 can be set as a spherical shape as a whole, and correspondingly, the second concave structure 124 is also set as a round hole, which has the advantage of greatly reducing the friction force when the lever 11 swings, so as to improve the smoothness.

[0080] Other technical features and technical effects are consistent with those of Example 5 and will not be elaborated here.

[0081] The present utility model is not limited to the above embodiments. If various modifications or deformations to the present utility model do not depart from the spirit and scope of the present utility model, and provided that these modifications and deformations fall within the scope of the claims of the present utility model and equivalent technical scope, then the present utility model also intends to encompass these modifications and deformations.

Claims

1. A piezoelectric actuator, characterized in that: include: A lever structure, a moving part, a first piezoelectric ceramic and a second piezoelectric ceramic, wherein on a projection plane in a vertical direction of the lever structure, a projection of the first piezoelectric ceramic and a projection of the second piezoelectric ceramic are respectively located on both sides of a projection of a fulcrum of the lever structure; During operation, the first piezoelectric ceramic applies a first force to move the movable part a first distance; and / or the second piezoelectric ceramic applies a second torque to the other end of the lever structure, and one end of the lever structure generates a first torque, and the first torque causes the movable part to move a second distance.

2. The piezoelectric actuator according to claim 1, characterized in that: The lever structure includes a lever and the fulcrum, and the fulcrum is arranged between two ends of the lever.

3. The piezoelectric actuator according to claim 2, characterized in that: The fulcrum is a protruding structure arranged on the lever.

4. The piezoelectric actuator according to claim 3, characterized in that: The lever is provided with a first through hole, the center axis of which is perpendicular to a projection plane of the lever in a vertical direction, and the fulcrum is provided in the first through hole and is gap-matched with the first through hole.

5. The piezoelectric actuator according to claim 2, wherein: A second through hole is arranged on the fulcrum, the central axis of the second through hole is parallel to the projection plane of the lever in the vertical direction, and the lever is arranged in the second through hole and is gap-matched with the second through hole.

6. The piezoelectric actuator according to claim 2, characterized in that: A third through hole is arranged on the side of the lever, the central axis of the third through hole is parallel to the projection plane of the lever in the vertical direction, and the fulcrum is arranged in the third through hole and is gap-matched with the third through hole.

7. The piezoelectric actuator according to claim 2, characterized in that: The fulcrum is a first concave structure disposed on the surface of the lever; It also includes a first fixing protrusion, one end of which abuts against the first concave structure.

8. The piezoelectric actuator according to claim 2, characterized in that: The fulcrum is a second concave structure disposed on the side surface of the lever; It also includes a second fixing protrusion, one end of which is disposed in the second concave structure and is gap-matched with the second concave structure.

9. The piezoelectric actuator according to claim 2, wherein: The first piezoelectric ceramic and the second piezoelectric ceramic are disposed on a surface of the lever at a predetermined distance.

10. The piezoelectric actuator according to claim 9, characterized in that: The fulcrum, the first piezoelectric ceramic, and the second piezoelectric ceramic are arranged on a surface of the lever.

11. The piezoelectric actuator according to claim 9, characterized in that: The fulcrum is arranged on the other surface of the lever.

12. The piezoelectric actuator according to claim 2, characterized in that: When the second piezoelectric ceramic applies the second torque to the other end of the lever, the position where the lever contacts the second piezoelectric ceramic is the second recessed portion; When the first piezoelectric ceramic applies the first torque to one end of the lever, the position where the lever contacts the first piezoelectric ceramic is a first recessed portion.

13. The piezoelectric actuator according to claim 1, wherein: The invention also includes a housing, wherein the lever structure, the first piezoelectric ceramic and the second piezoelectric ceramic are arranged inside the housing.

14. The piezoelectric actuator according to claim 13, characterized in that: A first pressing block and a second pressing block are also disposed inside the shell, wherein the first pressing block is located between the first piezoelectric ceramic and an inner wall of the shell, and the second pressing block is located between the second piezoelectric ceramic and an inner wall of the shell; The first pressing block is provided with a fourth through hole, one end of the moving member is arranged in the fourth through hole and contacts the first piezoelectric ceramic, and the other end of the moving member extends out of the housing; The second pressing block is provided with a fifth recessed portion, and the fifth recessed portion is in contact with the second piezoelectric ceramic.

15. The piezoelectric actuator according to claim 14, characterized in that: A third pressing block is further disposed inside the housing, and the third pressing block is located between the first piezoelectric ceramic and the second piezoelectric ceramic.

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