piezoceramic actuator

Abstract

The application discloses a piezoelectric ceramic actuator. In the application, the piezoelectric ceramic actuator comprises a shell, the shell is internally provided with a placement cavity with an open end, and the shell comprises a point contact part arranged at the other end in the placement cavity; a piezoelectric ceramic assembly comprises a piezoelectric ceramic piece, an elastic piece and a first contact part; the elastic piece is arranged opposite to the inner bottom surface of the shell, and the elastic piece is at least partially connected with the shell; one end of the piezoelectric ceramic piece is fixed to one side of the elastic piece away from the inner bottom surface of the shell; the first contact part is fixed to one side of the elastic piece towards the inner bottom surface of the shell and is arranged opposite to the piezoelectric ceramic piece, the first contact part is partially in a dome shape, the first contact part is partially in a dome shape, and the first contact part in the dome shape abuts against the point contact part to form a point contact. Compared with the prior art, the tangential stress of the actuator during use can be avoided, the service life is prolonged, and the piezoelectric ceramic piece is not prone to damage under stress.

Description

Technical Field

[0001] This invention relates to the field of micro-drive application technology, and in particular to a piezoelectric ceramic actuator. Background Technology

[0002] As various instruments and equipment demand increasingly higher precision in displacement control, the demand for micro-nano precision actuators is also growing, such as high-precision optical inspection equipment, deformable mirrors, electron microscope scanning stages, film thickness detection equipment, and piezoelectric dispensing equipment.

[0003] Piezoelectric ceramic actuators are a new type of micro-displacement device developed in recent years. Chinese patent CN111365621A proposes a piezoelectric actuator with electrical contact, which utilizes the physical deformation characteristics of piezoelectric ceramics under electrical current. This deformation is accumulated through the stacking of multiple ceramic sheets. However, this type of piezoelectric ceramic actuator may be subjected to tangential forces during use. If the piezoelectric ceramic component is subjected to tangential or torque forces during movement, it is prone to breakage. Furthermore, the internal piezoelectric ceramic component is also susceptible to fracture and damage under stress. Therefore, this solution can only be used in specific environments, limiting its application conditions. Additionally, the mechanism is extremely fragile and cannot withstand certain torque forces. Summary of the Invention

[0004] The purpose of this invention is to provide a piezoelectric ceramic actuator that can avoid tangential stress during use, thereby enabling the piezoelectric ceramic actuator to withstand higher loads, extend its service life, and prevent damage to the piezoelectric ceramic component under stress.

[0005] To address the aforementioned technical problems, embodiments of the present invention provide a piezoelectric ceramic actuator, comprising:

[0006] The housing has a placement cavity with one end open; and the housing includes a point contact portion disposed at the other end of the placement cavity.

[0007] A piezoelectric ceramic assembly is disposed within the placement cavity, located on the side of the point contact portion facing the opening of the placement cavity. It includes a piezoelectric ceramic element, an elastic element, and a first contact component. The elastic element is disposed opposite to the inner bottom surface of the outer shell, and at least partially connected to the outer shell. One end of the piezoelectric ceramic element is fixed to the side of the elastic element facing away from the inner bottom surface of the outer shell. When energized, the piezoelectric ceramic element can extend and retract along the direction from the inner bottom surface of the outer shell to the end of the placement cavity with the opening. The first contact component is fixed to the side of the elastic element facing the inner bottom surface of the outer shell and is disposed opposite to the piezoelectric ceramic element. A portion of the first contact component is dome-shaped, and the dome-shaped portion of the first contact component abuts against the point contact portion to form a point contact.

[0008] In one embodiment, the first contact component is a first hemispherical component, including a hemispherical surface and a connecting surface, wherein the hemispherical surface abuts against the point contact portion, and the connecting surface is fixed to the side of the elastic component facing the inner bottom surface of the housing.

[0009] In one embodiment, the housing includes: a shell and a base;

[0010] The shell is a tubular structure with openings at both ends;

[0011] The base has an upward-opening receiving cavity. The open end of the base is connected to one end of the shell, and the base closes one end of the shell to form the placement cavity. The bottom surface of the receiving cavity forms the inner bottom surface of the shell. The elastic element is disposed in the receiving cavity. The point contact portion is disposed in the receiving cavity, and the first contact component is disposed between the elastic element and the point contact portion.

[0012] In one embodiment, the point contact portion is the bottom surface of the receiving cavity;

[0013] The receiving cavity has a first chamber and a second chamber arranged from top to bottom, and the first chamber and the second chamber are connected; the cross-section of the first chamber is larger than the cross-section of the second chamber, and a shoulder is formed on the top of the second chamber;

[0014] The elastic element is placed on the shoulder and is separated from the bottom surface of the receiving cavity; and the housing is inserted into the first chamber and abuts against the shoulder.

[0015] In one embodiment, the point contact portion is a first biasing element;

[0016] The first biasing member is disposed within the receiving cavity, and at least a portion of the first biasing member is spaced apart from the bottom surface of the receiving cavity.

[0017] In one embodiment, the receiving cavity has a first chamber and a second chamber arranged from top to bottom, and the first chamber and the second chamber are connected; the cross-section of the first chamber is larger than the cross-section of the second chamber, and a shoulder is formed at the top of the second chamber;

[0018] The first biasing member is placed on the shoulder and is separated from the bottom surface of the receiving cavity; a holding member is provided on the shoulder to hold the first biasing member, the elastic member is placed on the top of the holding member, and the housing is inserted into the first cavity and abuts against the holding member.

[0019] In one embodiment, the piezoelectric ceramic assembly further includes an output shaft, a first end of which is connected to the end of the piezoelectric ceramic component away from the elastic element, and the output shaft is movably disposed at the opening of the placement cavity.

[0020] In one embodiment, a mounting hole is provided at the second end of the output shaft.

[0021] In one embodiment, the system further includes a cover, which is disposed at the opening end of the housing, connected to the housing, and covers the opening end of the housing.

[0022] The cover has a through hole, the output shaft passes through the through hole, and the output shaft moves within the through hole.

[0023] In one embodiment, at least part of the end of the output shaft connected to the piezoelectric ceramic component extends toward the side wall of the housing to form a support portion, and the support portion is spaced apart from the cover; a second biasing member is provided between the support portion and the cover, one end of the second biasing member abutting the support portion and the other end of the second biasing member abutting the cover.

[0024] In one embodiment, the cover is detachably connected to the outer shell.

[0025] In one embodiment, the second end of the output shaft is provided with a second contact member, which is at least partially dome-shaped.

[0026] In one embodiment, the elastic member includes a mating portion and an elastic portion disposed around the mating portion, wherein the piezoelectric ceramic member and the first contact member press the mating portion, and the elastic portion is connected to the outer shell; wherein the thickness of the mating portion is not less than the thickness of the elastic portion.

[0027] The present invention differs from the prior art in the following ways: the upper surface of the elastic element abuts against the piezoelectric ceramic element, the first contact component abuts against the elastic element, the first contact component is partially dome-shaped, the first contact component makes point contact with the point contact portion, and the elastic element is at least partially connected to the outer shell. These differences bring the following advantages: the deformation force exerted by the outer shell on the elastic element can counteract the tangential force transmitted from the piezoelectric ceramic element to the elastic element, thereby eliminating interference from the tangential force on the piezoelectric ceramic element. Simultaneously, it can prevent the piezoelectric ceramic element from breaking under the action of the tangential force, allowing the piezoelectric ceramic actuator to withstand higher loads, thus extending the service life of the piezoelectric ceramic actuator and enabling its application in more environments. Attached Figure Description

[0028] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0029] Figure 1 This is a schematic diagram of the structure of the piezoelectric ceramic actuator according to the first embodiment of the present invention;

[0030] Figure 2 This is a schematic diagram of the structure of the base of the piezoelectric ceramic actuator according to the first embodiment of the present invention;

[0031] Figure 3 This is a schematic diagram of the structure of the first contact component according to the first embodiment of the present invention;

[0032] Figure 4 This is a schematic diagram of the structure of the piezoelectric ceramic actuator with a second contact component according to the first embodiment of the present invention;

[0033] Figure 5 This is a schematic diagram of the elastic element according to the first embodiment of the present invention;

[0034] Figure 6 This is a schematic diagram of the housing structure of the piezoelectric ceramic actuator according to the first embodiment of the present invention;

[0035] Figure 7 This is a schematic diagram of the structure of the piezoelectric ceramic actuator according to the second embodiment of the present invention;

[0036] The components are as follows: 1. Outer shell; 10. Placement cavity; 11. Cover; 12. Housing; 13. Base; 131. Inner bottom surface; 132. First biasing component; 120. Mounting port; 14. Receiving cavity; 141. First chamber; 142. Second chamber; 143. Shoulder; 15. Holding component; 3. Piezoelectric ceramic assembly; 31. Piezoelectric ceramic component; 32. First contact component; 321. Hemispherical surface; 322. Connecting surface; 33. Output shaft; 330. Mounting hole; 331. Support part; 34. Second biasing component; 35. Second contact component; 36. Elastic component; 361. Elastic part; 362. Connecting part; 7. External thread; 8. Nut. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the various embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been presented in the various embodiments of the present invention to enable the reader to better understand this application. However, the technical solutions claimed in this application can be implemented even without these technical details and various changes and modifications based on the following embodiments.

[0038] In the following description, certain specific details are set forth for the purpose of illustrating various disclosed embodiments in order to provide a thorough understanding of the various disclosed embodiments. However, those skilled in the art will recognize that embodiments may be practiced without one or more of these specific details. In other instances, well-known apparatuses, structures, and techniques associated with this application may not have been shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

[0039] Unless the context requires otherwise, throughout the specification and claims, the word “comprising” and its variations, such as “including” and “having”, shall be understood to have an open, inclusive meaning, that is, to be interpreted as “including, but not limited to”.

[0040] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings to provide a clearer understanding of the purpose, features, and advantages of the present invention. It should be understood that the embodiments shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative of the essential spirit of the technical solution of the present invention.

[0041] Throughout this specification, references to "an embodiment" or "an embodiment" indicate that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Therefore, the appearance of "in an embodiment" or "an embodiment" in various places throughout the specification does not necessarily refer to the same embodiment. Furthermore, a particular feature, structure, or characteristic may be combined in any manner in one or more embodiments.

[0042] The singular forms “a” and “the” used in this specification and the appended claims include plural references unless otherwise expressly stated herein. It should be noted that the term “or” is generally used to mean “and / or” unless otherwise expressly stated herein.

[0043] In the following description, in order to clearly demonstrate the structure and working method of the present invention, a number of directional terms will be used. However, terms such as "front", "back", "left", "right", "outside", "inside", "outward", "inward", "up", and "down" should be understood as convenient terms and not as limiting terms.

[0044] Example 1

[0045] The first embodiment of the present invention will now be described with reference to the accompanying drawings. Figure 1 As shown, the piezoelectric ceramic actuator includes: a housing 1 and a piezoelectric ceramic assembly 3. The housing 1 has a placement cavity 10 with one end open. Figure 1In this embodiment, the top of the placement cavity 10 is open, and the bottom of the placement cavity 10 is the inner bottom surface 131 of the outer shell 1. The outer shell 1 includes a point contact portion, which is located at the other end of the placement cavity 10, i.e., the bottom end of the placement cavity 10. In this embodiment, the point contact portion is the inner bottom surface 131. The piezoelectric ceramic assembly 3 is disposed in the placement cavity 10. The piezoelectric ceramic assembly 3 includes a piezoelectric ceramic element 31, an elastic element 36, and a first contact element 32. The elastic element 36 is disposed opposite to the inner bottom surface 131, and the elastic element 36 is at least partially connected to the outer shell 1. One end of the piezoelectric ceramic element 31 is fixed to the side of the elastic element 36 facing the opening of the placement cavity 10, i.e., the upper surface of the elastic element 36 shown in the figure. The piezoelectric ceramic element 31 can be moved and stretched in the direction from the bottom end to the top end of the placement cavity 10 when energized and when energized is de-energized, i.e., the piezoelectric ceramic element 31 deforms along its axial direction. Furthermore, an external wire can be connected to the piezoelectric ceramic element 31 through the outer shell 1. When energized, the piezoelectric ceramic component 31 undergoes physical deformation and extension, thereby outputting displacement along its axial direction. The first contact component 32 is fixed to the side of the elastic component 36 facing away from the opening end of the placement cavity 10, i.e., the lower surface of the elastic component 36 shown in the figure, and is disposed opposite to the piezoelectric ceramic component 31. The first contact component 32 is partially dome-shaped, and the outer surface of the dome abuts against the point contact portion to form a point contact, i.e., a point contact is formed between the first contact component 32 and the inner bottom surface 131.

[0046] The piezoelectric ceramic component 31, the elastic component 36, and the first contact component 32 coincide in the vertical centerline.

[0047] The cross-section of the contact surface between the first contact component 32 and the elastic component 36 is called the first cross-section, and the cross-section of the contact surface between the piezoelectric ceramic component 31 and the elastic component 36 is called the second cross-section. In this embodiment, the first cross-section and the second cross-section are equal. In other embodiments, the first cross-section and the second cross-section may not be equal, and this embodiment does not limit them.

[0048] In specific implementation, such as Figure 1 As shown, the piezoelectric ceramic component 31 can be a ceramic stack or a single ceramic component. The top of the placement cavity 10 has an opening. When the piezoelectric ceramic component 31 is energized and expands, the piezoelectric ceramic assembly 3 rises. The piezoelectric ceramic assembly 3 can partially extend out of the placement cavity 10 to push a platform or support device outside the piezoelectric ceramic actuator, thereby changing the height of the platform or support device and thus realizing longitudinal movement of the platform or support device.

[0049] The differences between this invention and the prior art are as follows: the upper surface of the elastic element 36 abuts against the piezoelectric ceramic element 31, the first contact element 32 abuts against the elastic element 36, the first contact element 32 is partially dome-shaped, the first contact element 32 makes point contact with the point contact portion (in this embodiment, the point contact portion is the inner bottom surface 131), and the elastic element 36 is at least partially connected to the outer shell 1. These differences bring the following advantages: by utilizing the deformation force of the outer shell on the elastic element, the tangential force that the piezoelectric ceramic element may experience can be offset, thereby eliminating the interference of the tangential force on the piezoelectric ceramic element. Simultaneously, it can prevent the piezoelectric ceramic element from breaking under the action of the tangential force, allowing the piezoelectric ceramic actuator to withstand higher loads, thus extending the service life of the piezoelectric ceramic actuator and enabling its application in more environments. For example, when the piezoelectric ceramic actuator encounters collisions or drops, it will be subjected to bending stress. The elastic element can reduce or avoid the impact of bending stress on the piezoelectric ceramic element, making the piezoelectric ceramic element less prone to damage.

[0050] like Figure 1 and Figure 2 As shown, the outer casing 1 includes a shell 12 and a base 13. The shell 12 is a tubular structure with openings at both ends. The base 13 has an upward-facing accommodating cavity 14. The open end of the base 13 is connected to one end of the shell 12, and the base 13 closes one end opening of the shell 12 to form the aforementioned placement cavity 10. The bottom surface of the accommodating cavity 14 forms the inner bottom surface 131 of the outer casing 1, i.e., the point contact portion is the bottom surface of the accommodating cavity 14. An elastic member 2 is disposed within the accommodating cavity 14, and a first contact member 32 is disposed between the elastic member 2 and the point contact portion.

[0051] Furthermore, the piezoelectric ceramic actuator also includes a cover 11, which is disposed at the open end of the housing 1, connected to the housing 1, and covers the open end of the housing 1. For example... Figure 1 As shown, in this embodiment, the top of the housing 12 has a mounting opening 120, and a cover 11 connected thereto is provided on the top of the housing 12. The cover 11 covers the mounting opening 120, i.e., the open end of the outer shell 1, and the base 13 is connected to the bottom of the housing 12. The cover 11 is detachably connected to the housing 12, so that the cover 11 can be removed for easy maintenance of the components inside the piezoelectric ceramic actuator, thus reducing costs. In specific implementations, the cover 11 and the housing 12 can be connected by a threaded connection or by a clamp connection, or other detachable connection methods.

[0052] In addition, such as Figure 1 and Figure 2 As shown, the structural shape of the connection between the base 13 and the housing 12 is matched. The base 13 and the housing 12 are detachably connected, so that the base 13 and the housing 12 can be separated, which facilitates maintenance and replacement of parts. This solves the problem of the actuator being unmaintainable in the prior art and can further reduce costs.

[0053] Specifically, in this embodiment, as Figure 1 and Figure 2 As shown, the receiving cavity 14 has a first chamber 141 and a second chamber 142 arranged from top to bottom, and the first chamber 141 and the second chamber 142 are connected. The cross-section of the first chamber 141 is larger than the cross-section of the second chamber 142, and a shoulder 143 is formed on the top of the second chamber 142. The elastic member 36 is placed on the shoulder 143 and is spaced apart from the bottom of the cavity. The housing 12 is inserted into the first chamber 141 and abuts against the shoulder 143, which supports the elastic member 36. The shoulder 143 limits the housing 12 and abuts against the bottom of the housing 12. The housing 12 and the shoulder 143 cooperate to clamp the elastic member 36, thereby fixing the elastic member 36.

[0054] like Figure 1 As shown, when the base 13 is detachably connected to the housing 12, and the housing 12 is threadedly connected to the side wall of the first chamber 141, that is, the base 13 is threadedly connected to the housing 12. A safe space is formed inside the housing 1, allowing the piezoelectric ceramic component 31 to be enclosed within the housing 1, protecting the piezoelectric ceramic component 31 from external influences and ensuring its service life. In addition, since the base 13 and the housing 12 are detachably connected, a completely sealed cavity is not formed inside the piezoelectric ceramic actuator. Therefore, the piezoelectric ceramic actuator can be used in a vacuum environment without being affected by the pressure difference generated by the vacuum environment, and of course, it can also be used in ordinary environments.

[0055] Understandable, such as Figure 1 and Figure 2 As shown, the housing 12 and the side wall of the first chamber 141 can also be fixed by snap-fit. Alternatively, when the housing 12 and the base 13 are not detachable, they can be directly glued together. Or, the housing 12 and the base 13 can be an integral structure. The fixing of the housing 12 and the base 13 is not limited to the form where the housing 12 is inserted into the base 13. The base 13 can also be inserted into the housing 12, with threads on the inner wall of the housing 12 and threads on the outer wall of the base 13. The housing 12 and the base 13 are fixed by screwing together. In this case, the elastic element 36 can be directly glued or snap-fitted into the base 13. There are various connection methods between the housing 12 and the base 13, which will not be listed here.

[0056] In addition, such as Figure 1As shown, an output shaft 33 is provided at the end of the piezoelectric ceramic component 31 facing away from the elastic component 36. A through hole is provided on the cover 11, through which the output shaft 33 passes, and the output shaft 33 can freely extend and retract within the through hole. The two ends of the output shaft 33 along the axial direction are defined as a first end and a second end. The first end of the output shaft 33 is connected to the end of the piezoelectric ceramic component 31 facing away from the first biasing component 2, and the output shaft 33 is movably disposed at the opening of the placement cavity 10. The second end of the output shaft 33 is the output end, and a mounting hole 330 is provided at the second end of the output shaft 33. A mounting component can be inserted through the mounting hole 330, thereby connecting the output shaft 33 to an external platform or supporting device, etc. The output shaft 33 can be glued to the piezoelectric ceramic component 31 or fixed to the piezoelectric ceramic component 31 by snap-fit ​​or locking components. Understandably, the height of the housing 1 can also be higher than the top of the cover 11. In this case, the output shaft 33 extends out of the cover 11, but the output shaft 33 is still inside the housing 1. An extension shaft can be connected to the output shaft 33 to support the platform.

[0057] Specifically, such as Figure 1 and Figure 2 As shown, at least part of the first end of the output shaft 33 extends toward the side wall of the housing 12, forming a support portion 331, which is spaced apart from the cover 11. To pre-tighten the piezoelectric ceramic component 31, a second biasing member 34 is provided between the support portion 331 and the cover 11. One end of the second biasing member 34 abuts against the support portion 331, and the other end abuts against the cover 11, ensuring that the piezoelectric ceramic component 31 can be fully disposed within the placement cavity 10 and provided with a pre-tightening force. The placement cavity 10 is a cylindrical chamber. The external shape of the support portion 331 matches the cross-sectional shape of the placement cavity 10 and abuts against the wall of the placement cavity 10. When the piezoelectric ceramic component 31 deforms, it pushes the output shaft 33 to move, thereby outputting displacement, and the support portion 331 slides along the wall of the placement cavity 10. It is understood that the placement cavity 10 can also be a chamber of other shapes, as long as it can provide sufficient space for the components inside the housing. Understandably, the top of the housing 1 is an open end, which may or may not be covered by a cover. When there is no cover, the output shaft 33 supports the open end that extends through the top of the housing 1. Furthermore, the size of the opening at the open end matches the size of the output shaft 33.

[0058] like Figure 1As shown, the second biasing component 34 can be a disc spring (hereinafter referred to as the disc spring). This disc spring is located between the support part 331 of the output shaft 33 and the cover 11. When the cover 11 is tightened downwards using threads, the distance between the cover 11 and the support part 331 is shortened, the disc spring is compressed, and at the same time, the disc spring outputs a certain amount of elastic force. The relationship curve formed by the elastic force of the disc spring and the deformation of the disc spring tends to stabilize after a certain deformation, that is, after a certain deformation, the output elastic force of the disc spring reaches a stable value and remains at a certain value. This ensures that the piezoelectric ceramic component 31 outputs displacement during the use of the mechanism, and the output elastic force of the disc spring remains constant when the disc spring is further compressed. The first contact component 32 makes point contact with the inner bottom surface 131, and the disc spring is set in a state where the externally output elastic force reaches a stable value. Thus, the output shaft 33 and the piezoelectric ceramic component 31 can move at the same frequency. When the piezoelectric ceramic component 31 returns to its original position, it can drive the output shaft 33 to return to its original position synchronously, resulting in higher precision of the piezoelectric ceramic actuator. Understandably, the second biasing element 34 can be a rubber elastic block or a combination of multiple disc springs. As long as the second biasing element 34 reaches a stable elastic force after a certain compression deformation, it will remain at a certain value.

[0059] Before energizing, the preload of the second biasing element 34 on the piezoelectric ceramic element 31 reaches a constant value. When the piezoelectric ceramic element 31 is energized, the piezoelectric ceramic element 31 expands and extends in the axial direction. The second biasing element 34 is pushed by the piezoelectric ceramic element 31 to deform. The pressure of the second biasing element 34 on the piezoelectric ceramic element 31 remains unchanged. The deformation of the piezoelectric ceramic element 31 is completely converted into the displacement output of the piezoelectric ceramic assembly 3.

[0060] In some embodiments, such as Figure 4 As shown, the second end of the output shaft 33 has a second contact component 35. The second contact component 35 is at least partially dome-shaped, and can be a spherical cap, in which case its outer surface is a spherical crown. Preferably, the second contact component 35 is a second hemispherical component, which is a tungsten carbide hemisphere or a ceramic hemisphere. It is understood that the second contact component 35 can have an upper part that is a spherical cap and a lower part that is a cylinder. The second contact component 35 can be glued to the output shaft 33, or fixed to the output shaft 33 by snap-fit ​​or locking. It is understood that the second contact component 35 can also be a semi-elliptical component or other irregular component. In principle, the second contact component 35 can form point contact with an external platform or supporting device. The design of the second contact component 35 better ensures that the force on the piezoelectric ceramic component 31 is only in the axial direction of the piezoelectric ceramic component 31, ensuring the normal use of the piezoelectric ceramic component 31 and preventing it from being affected by tangential forces. It should be noted that in Figure 4In this embodiment, the second end of the output shaft 33 is provided with a mounting hole 330, and the second contact member 35 is disposed above the mounting hole 330. At this time, the second contact member 35 and the output shaft 33 can be detachably connected. In practical applications, the connection method between the output shaft 33 and the external device can be selected according to different scenarios, that is, connected through the mounting hole 330 or connected through the second contact member 35. In some embodiments, the mounting hole 330 may not be provided on the output shaft 33, and the second contact member 35 is fixed to the second end of the output shaft 33.

[0061] In addition, such as Figure 3 As shown, the first contact component 32 is a first hemispherical component, including a hemispherical surface 321 and a connecting surface 322. The hemispherical surface 321 abuts against the inner bottom surface 131, and the connecting surface 322 is fixed to the side of the elastic component 36 facing the inner bottom surface 131.

[0062] Understandably, the first contact component 32 can also be a spherical cap, in which case the outer surface of the first contact component 32 is a spherical crown. The height of the spherical cap is greater than or less than the radius of the sphere it is in. Alternatively, the first contact component 32 can also have an upper part as a cylinder and a lower part as a spherical cap, with the cylinder connected to the elastic member 36.

[0063] Furthermore, such as Figure 5 As shown, the elastic member 36 includes a mating portion 362 and an elastic portion 361 disposed around the mating portion 362. The piezoelectric ceramic member 31 and the first contact member 32 press the mating portion 362, and the elastic portion 361 is connected to the outer shell 1. The elastic portion 361 can be disposed around the mating portion 362. The thickness of the mating portion 362 is not less than the thickness of the elastic portion 361. Figure 5 As shown, the thickness of the mating portion 362 is greater than the thickness of the elastic portion 361. In this case, the elastic portion 361 is a thin, elastic sheet, while the mating portion 362 can be made of either an inelastic or elastic material. Figure 1 and Figure 4 The thickness of the elastic element 36 and the mating portion 361 shown is equal to the thickness of the elastic portion 361. In this case, the elastic element 36 as a whole can be a sheet, i.e., a metal sheet or a plastic sheet. The cross-section of the mating portion 362 is called the third cross-section. In some embodiments, the first cross-section, the second cross-section, and the third cross-section are all equal, which makes positioning and assembly easier; in other embodiments, the first cross-section, the second cross-section, and the third cross-section may not be equal, and the present invention does not limit them.

[0064] To facilitate the installation and removal of the piezoelectric ceramic actuator from the equipment in which it is used, a connecting part is provided on the housing. This connecting part is located on the outer wall of the housing and is used to fix the housing to the equipment. For example... Figure 6As shown, the connecting part is provided with an external thread 7, which is formed on the outer wall surface of the housing 12. Figure 1 As shown, the piezoelectric ceramic actuator 100 also has a nut 8 sleeved on the housing. When the piezoelectric ceramic actuator is installed on the equipment, it is threaded into the equipment, and then the nut is tightened by reverse pressure to fix the piezoelectric ceramic actuator in the required position. The piezoelectric ceramic actuator can also be disassembled and installed on other equipment for repeated use, which also facilitates the maintenance of the piezoelectric ceramic actuator. At the same time, the extension of the piezoelectric ceramic actuator can also be adjusted by using the nut to fix it in the required extension position. Understandably, other components such as slots can also be provided at the connection part to achieve connection, as long as they can achieve the goal of detachably fixing the housing to the equipment where the piezoelectric ceramic actuator is used.

[0065] Example 2

[0066] The second embodiment of the present invention relates to a piezoelectric ceramic actuator. The second embodiment is largely the same as the first embodiment, with the main difference being that in the first embodiment, the point contact portion is the inner bottom surface 131. However, in the second embodiment of the present invention, as... Figure 7 As shown, the point contact portion is the first biasing member 132 disposed in the base 13.

[0067] like Figure 7 As shown, the first biasing member 132 is placed on the shoulder 143 and is spaced apart from the bottom surface of the receiving cavity 14, which provides sufficient deformation space for the first biasing member 132. A holding member 15 is provided on the shoulder 143 to hold the first biasing member 132. An elastic member 36 is placed on top of the holding member 15, and the housing 12 is inserted into the first cavity 141 and abuts against the holding member 15. The housing 12 and the holding member 15 cooperate to clamp the elastic member 36, thereby fixing the elastic member 36. The first biasing member 132 can be directly glued or snapped into the base 13. The first contact component 32 forms a point contact with the first biasing component 132. The first biasing component 132 pushes against the piezoelectric ceramic component 31 along the axial direction of the piezoelectric ceramic component 31, so that the direction of the force on the piezoelectric ceramic component 31 is always on the axial direction of the piezoelectric ceramic component 31. Therefore, even if the output end of the piezoelectric ceramic component 31 located outside the housing 12 is subjected to a radial force (tangential force), the piezoelectric ceramic component 31 located inside the housing 12 is only subjected to a force along its axial direction. This structure can prevent the piezoelectric ceramic component 31 from breaking and being damaged under the action of tangential force, thereby allowing the piezoelectric ceramic component 31 to withstand higher loads, extending the service life of the piezoelectric ceramic component 31, and enabling it to be used in more environments.

[0068] like Figure 7As shown, the second biasing element 34 can be a disc spring (hereinafter referred to as the disc spring). This disc spring is located between the support part 331 of the output shaft 33 and the cover 11. When the cover 11 is tightened downwards using threads, the distance between the cover 11 and the support part 331 is shortened, the disc spring is compressed, and at the same time, the disc spring outputs a certain amount of elastic force. The relationship curve formed by the elastic force of the disc spring and the deformation of the disc spring tends to stabilize after a certain deformation, that is, after a certain deformation, the output elastic force of the disc spring reaches a stable value and remains at a certain value. This ensures that the piezoelectric ceramic component 31 outputs displacement during the use of this mechanism, and the output elastic force of the disc spring remains constant when the disc spring is further compressed. The disc spring is set in a state where the externally output elastic force has reached a stable value. The first biasing element 132 can be a spring. Under the influence of a force within the range of the aforementioned continuous and stable elastic force of the disc spring, this spring exhibits a linear deformation curve, allowing the output shaft 33 to move at the same frequency as the piezoelectric ceramic component 31. The elastic force of the disc spring causes the output shaft 33 to return to its original position synchronously when the piezoelectric ceramic component 31 returns to its original position, resulting in higher precision for the piezoelectric ceramic actuator. Understandably, the second biasing element 34 can be a rubber elastic block or a combination of multiple disc springs. As long as the elastic force output by the second biasing element 34 stabilizes and remains at a certain value after a certain degree of compression deformation, it is acceptable.

[0069] Before energization, the preload force of the second biasing element 34 and the first biasing element 132 on the piezoelectric ceramic element 31 is the same, F1. This preload is equal to the elastic force value at the elastic deformation inflection point of the second biasing element (i.e., the elastic force output by the second biasing element 34 reaches a stable value and remains at a certain level). At this elastic deformation inflection point, even if the second biasing element 34 is further compressed and deformed, the force output remains essentially unchanged. The effective deformation curve of the first biasing element 132 is linear, requiring increased pressure to increase the deformation. Therefore, since the elastic force applied by the second biasing element 34 remains constant, the first biasing element 132 maintains a certain deformation. Thus, when the piezoelectric ceramic component 31 is energized, it expands and extends in the axial direction. The second biasing component 34 is pushed and deformed by the piezoelectric ceramic component 31, but the pressure of the second biasing component 34 on the piezoelectric ceramic component 31 remains unchanged. Therefore, the force exerted by the piezoelectric ceramic component 31 on the first biasing component 132 will not change, which prevents the first biasing component 132 from deforming. That is, the deformation of the piezoelectric ceramic component 31 is completely converted into the displacement output of the piezoelectric ceramic assembly 3.

[0070] In some embodiments, the first biasing element 132 may also be an elastic block or other elastic component, as long as the effective deformation curve of the first biasing element 132 is linear (the effective deformation curve being linear means that the deformation curve of the first biasing element 132 in the preset position state of the piezoelectric ceramic actuator of the present invention is linear). When the first biasing element 132 is an elastic block, the first biasing element 132 is directly embedded in the receiving cavity 14 of the base 13. The upper surface of the first biasing element 132 is an elastic surface with a certain strength. The sidewall or bottom surface of the first biasing element 132 is fixed to the base 13. The elastic surface can be elastically deformed, and when deformed, the elastic surface has one and only one contact point with the first contact component 32. It is understood that the structure of the first biasing element 132 can be various, as long as it can achieve the purpose of point contact between the first contact portion 32 and the first biasing element 132 during the contact process.

[0071] The preferred embodiments of the present invention have been described in detail above, but it should be understood that, if necessary, aspects of the embodiments can be modified to utilize aspects, features, and concepts from various patents, applications, and publications to provide other embodiments.

[0072] In light of the detailed description above, these and other changes can be made to the embodiments. Generally, the terminology used in the claims should not be considered limited to the specific embodiments disclosed in the specification and claims, but should be understood to include all possible embodiments together with the full scope of equivalents enjoyed by these claims.

[0073] Those skilled in the art will understand that the above embodiments are specific examples of implementing the present invention, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the present invention.

Claims

1. A piezoelectric ceramic actuator, characterized in that, include: The housing has a placement cavity with one end open; and the housing includes a point contact portion disposed at the other end of the placement cavity. A piezoelectric ceramic assembly is disposed within the placement cavity, located on the side of the point contact portion facing the opening of the placement cavity. It includes a piezoelectric ceramic element, an elastic element, and a first contact component. The elastic element is disposed opposite to the inner bottom surface of the outer shell, and at least partially connected to the outer shell. One end of the piezoelectric ceramic element is fixed to the side of the elastic element away from the inner bottom surface of the outer shell. When energized, the piezoelectric ceramic element can extend and retract along the direction from the inner bottom surface of the outer shell to the end of the placement cavity with the opening. The first contact component is fixed to the side of the elastic element facing the inner bottom surface of the outer shell and is disposed opposite to the piezoelectric ceramic element. A portion of the first contact component is dome-shaped, and the dome-shaped portion of the first contact component abuts against the point contact portion to form a point contact. The piezoelectric ceramic assembly further includes an output shaft, a first end of which is connected to the end of the piezoelectric ceramic component away from the elastic element, and the output shaft is movably disposed at the opening of the placement cavity; The elastic element includes a mating portion and an elastic portion disposed around the mating portion, wherein the piezoelectric ceramic element and the first contact component press the mating portion, and the elastic portion is connected to the outer shell; wherein the thickness of the mating portion is greater than the thickness of the elastic portion.

2. The piezoelectric ceramic actuator according to claim 1, characterized in that, The first contact component is a first hemispherical component, including a hemispherical surface and a connecting surface. The hemispherical surface abuts against the point contact portion, and the connecting surface is fixed to the side of the elastic component facing the inner bottom surface of the outer shell.

3. The piezoelectric ceramic actuator according to claim 1 or 2, characterized in that, The outer casing includes: a housing and a base; The shell is a tubular structure with openings at both ends; The base has an upward-opening receiving cavity. The open end of the base is connected to one end of the shell, and the base closes one end of the shell to form the placement cavity. The bottom surface of the receiving cavity forms the inner bottom surface of the shell. The elastic element is disposed in the receiving cavity. The point contact portion is disposed in the receiving cavity, and the first contact component is disposed between the elastic element and the point contact portion.

4. The piezoelectric ceramic actuator according to claim 3, characterized in that, The point contact portion is the bottom surface of the receiving cavity; The receiving cavity has a first chamber and a second chamber arranged from top to bottom, and the first chamber and the second chamber are connected; the cross-section of the first chamber is larger than the cross-section of the second chamber, and a shoulder is formed on the top of the second chamber; The elastic element is placed on the shoulder and is separated from the bottom surface of the receiving cavity; and the housing is inserted into the first chamber and abuts against the shoulder.

5. The piezoelectric ceramic actuator according to claim 3, characterized in that, The point contact portion is the first biasing element; The first biasing member is disposed within the receiving cavity, and at least a portion of the first biasing member is spaced apart from the bottom surface of the receiving cavity.

6. The piezoelectric ceramic actuator according to claim 5, characterized in that, The receiving cavity has a first chamber and a second chamber arranged from top to bottom, and the first chamber and the second chamber are connected; the cross-section of the first chamber is larger than the cross-section of the second chamber, and a shoulder is formed on the top of the second chamber; The first biasing member is placed on the shoulder and is separated from the bottom surface of the receiving cavity; a holding member is provided on the shoulder to hold the first biasing member, the elastic member is placed on the top of the holding member, and the housing is inserted into the first cavity and abuts against the holding member.

7. The piezoelectric ceramic actuator according to claim 1, characterized in that, The second end of the output shaft has a mounting hole.

8. The piezoelectric ceramic actuator according to claim 1 or 7, characterized in that, It also includes a cover, which is disposed at the opening end of the outer shell, connected to the outer shell, and covers the opening end of the outer shell; The cover has a through hole, the output shaft passes through the through hole, and the output shaft moves within the through hole.

9. The piezoelectric ceramic actuator according to claim 8, characterized in that, The first end of the output shaft extends at least partially toward the side wall of the housing to form a support portion, and the support portion is spaced apart from the cover. A second biasing member is provided between the support portion and the cover, one end of the second biasing member abutting the support portion and the other end of the second biasing member abutting the cover.

10. The piezoelectric ceramic actuator according to claim 9, characterized in that, The cover is detachably connected to the outer shell.

11. The piezoelectric ceramic actuator according to claim 1, characterized in that, The second end of the output shaft is provided with a second contact component, which is at least partially dome-shaped.

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