A piezoelectric ring stack

Abstract

The application discloses a piezoelectric ring-shaped stack, and relates to the technical field of piezoelectric stacks. The piezoelectric ring-shaped stack comprises at least one second piezoelectric sheet, the second piezoelectric sheet comprises a substrate, a third electrode and a fourth electrode, the third electrode and the fourth electrode are arranged on the upper and lower sides of the substrate respectively, a through hole is arranged in the middle of the substrate, the third electrode extends to the inner side wall of the through hole, thereby forming an inner connecting part, and the fourth electrode extends to the outer side wall of the substrate, thereby forming an outer connecting part; in a stacked state, the inner connecting part and the outer connecting part on the second piezoelectric sheet are connected with corresponding electrodes on an adjacent piezoelectric sheet, and parallel connection is realized. The application has the beneficial effect that the structural design optimizes insulation impedance, the external soldering lead and the complex conductive adhesive network required in the traditional structure are abandoned, the structure is simplified, the radial size occupation of the piezoelectric stack is reduced, the whole stack structure is more compact, and the application scene with higher requirements for equipment miniaturization or microminiaturization is met.

Description

Technical Field

[0001] This application relates to the field of piezoelectric stack technology, and in particular discloses a piezoelectric ring stack. Background Technology

[0002] Piezoelectric micropumps and piezoelectric atomizing plates are core components in the field of modern precision fluid control and transmission. They are widely used in medical atomization, electronic cigarettes, microfluidic chips, semiconductor cooling, wearable / portable devices, and humidifiers. Their core driving element is usually a piezoelectric stack. This type of element converts electrical energy into mechanical vibration through the inverse piezoelectric effect, thereby driving fluid flow or generating microdroplets. To meet the requirements of high reliability, long life and miniaturization of these devices, the piezoelectric stack must have the characteristics of compact structure, high energy density, low driving voltage and stable performance.

[0003] Currently, most common piezoelectric stacks employ a structure of multiple layers of piezoelectric ceramic sheets stacked in parallel. To achieve electrical connection after stacking, traditional processes often rely on soldering a large number of leads or setting up complex conductive adhesive networks on the outside of the piezoelectric elements. This external connection method has significant drawbacks: First, the additional wiring space makes it difficult to reduce the overall size of the stack, which is not conducive to the miniaturization or micro-miniaturization design of the equipment; second, the solder joints and leads are prone to fatigue fracture under long-term high-frequency vibration, which may also lead to short circuits, reducing the reliability of the equipment; in addition, the assembly process under traditional methods is quite complex, reducing production efficiency and increasing production costs, thus requiring improvement. Utility Model Content

[0004] The purpose of this application is to provide a piezoelectric toroidal stack.

[0005] To achieve the above objectives, the technical solution adopted in this application is as follows: a piezoelectric ring stack, comprising at least one second piezoelectric sheet, the second piezoelectric sheet comprising a substrate, a third electrode and a fourth electrode, the third electrode and the fourth electrode being respectively disposed on the upper and lower sides of the substrate, a through hole being provided in the middle of the substrate, the third electrode extending to the inner sidewall of the through hole to form an inner connection portion, and the fourth electrode extending to the outer sidewall of the substrate to form an outer connection portion; in the stacked state, the inner connection portion and the outer connection portion on the second piezoelectric sheet are connected to the corresponding electrodes on the adjacent piezoelectric sheet to achieve parallel connection.

[0006] As a preferred embodiment, the third electrode is annular, and its outer diameter is configured to be smaller than the outer diameter of the substrate, and the fourth electrode is annular, and its inner diameter is configured to be larger than the diameter of the through hole.

[0007] As a preferred embodiment, the piezoelectric annular stack is further provided with a first piezoelectric sheet, the first piezoelectric sheet including a substrate, a first electrode and a second electrode, the first electrode and the second electrode being respectively disposed on the upper and lower sides of the substrate, a through hole being provided in the middle of the substrate, the first electrode extending to the outer sidewall of the substrate to form an outer connection portion, the second electrode being annular with an outer diameter equal to the outer diameter of the third electrode; and / or the piezoelectric annular stack is further provided with a third piezoelectric sheet, the third piezoelectric sheet including a substrate, a fifth electrode and a sixth electrode, the fifth electrode and the sixth electrode being respectively disposed on the upper and lower sides of the substrate, a through hole being provided in the middle of the substrate, the sixth electrode extending to the inner sidewall of the through hole to form an inner connection portion, the fifth electrode being annular with an inner diameter equal to the inner diameter of the fourth electrode.

[0008] More preferably, the second electrode and the third electrode have the same area, and the fourth electrode and the fifth electrode have the same area.

[0009] More preferably, the area of ​​the first electrode is equal to that of the upper surface of the substrate, and the area of ​​the sixth electrode is equal to that of the lower surface of the substrate.

[0010] Further preferably, the piezoelectric ring stack includes a first piezoelectric sheet, a third piezoelectric sheet, and a second piezoelectric sheet. When stacked, the first piezoelectric sheet and the third piezoelectric sheet are respectively placed on both sides of the second piezoelectric sheet. The second electrode is connected to the third electrode. The first electrode and the fourth electrode are interconnected through corresponding external connection parts. The fourth electrode is connected to the fifth electrode. The sixth electrode and the third electrode are interconnected through corresponding internal connection parts to achieve parallel connection.

[0011] Further preferably, the piezoelectric ring stack includes a first piezoelectric sheet, a third piezoelectric sheet, and an odd number of second piezoelectric sheets, wherein the number of second piezoelectric sheets is greater than one. When stacked, the first piezoelectric sheet and the third piezoelectric sheet are respectively placed at both ends of the piezoelectric ring stack. The second electrode is connected to the third electrode on the adjacent second piezoelectric sheet. The first electrode is interconnected with the fourth electrode on the adjacent second piezoelectric sheet through a corresponding external connection part. The fifth electrode is connected to the fourth electrode on the adjacent second piezoelectric sheet. The sixth electrode is interconnected with the third electrode on the adjacent second piezoelectric sheet through a corresponding internal connection part. The polarization directions of adjacent second piezoelectric sheets are opposite, and they are interconnected through the corresponding internal connection parts and the corresponding external connection parts to achieve parallel connection.

[0012] Further preferably, the piezoelectric ring stack includes a first piezoelectric sheet and an even number of second piezoelectric sheets, with a minimum of two second piezoelectric sheets. When stacked, the first piezoelectric sheet is placed at one end of the piezoelectric ring stack, the second electrode is connected to the third electrode on the adjacent second piezoelectric sheet, and the first electrode is interconnected with the fourth electrode on the adjacent second piezoelectric sheet through corresponding external connecting parts. The polarization directions of adjacent second piezoelectric sheets are opposite, and they are interconnected through corresponding internal connecting parts and corresponding external connecting parts to achieve parallel connection.

[0013] Further preferably, the piezoelectric ring stack includes a third piezoelectric sheet and an even number of second piezoelectric sheets, with a minimum of two second piezoelectric sheets. When stacked, the third piezoelectric sheet is placed at one end of the piezoelectric ring stack. The fifth electrode is connected to the fourth electrode on the adjacent second piezoelectric sheet. The sixth electrode is interconnected with the third electrode on the adjacent second piezoelectric sheet through a corresponding internal connection portion. The polarization directions of adjacent second piezoelectric sheets are opposite, and they are interconnected with the corresponding external connection portion through the corresponding internal connection portion to achieve parallel connection.

[0014] As a preferred embodiment, the piezoelectric ring stack is formed by stacking an odd number of second piezoelectric sheets, with a minimum of three second piezoelectric sheets. Adjacent second piezoelectric sheets have opposite polarization directions and are interconnected with corresponding inner connecting parts and corresponding outer connecting parts to achieve parallel connection.

[0015] Compared with the prior art, the beneficial effects of this application are as follows: (1) This application extends the electrode to the inner sidewall of the through hole and the outer sidewall of the substrate to form an inner connection part and an outer connection part. Parallel connection is achieved by connecting the corresponding inner connection parts and the corresponding outer connection parts between adjacent components during stacking. This structural design eliminates the external welding leads and complex conductive adhesive network required by the traditional structure, simplifies the structure, reduces the radial dimension occupied by the piezoelectric stack, and makes the entire stack structure more compact, which meets the application scenarios with high requirements for device miniaturization or micro-miniaturization.

[0016] (2) This application achieves parallel connection by interconnecting the corresponding internal connection parts and the corresponding external connection parts between adjacent components. No external solder joints and flying wires are required, which effectively avoids the risk of fatigue fracture under long-term high-frequency vibration and also avoids the risk of short circuit. The internal connection parts and external connection parts in this application are part of the stacked structure, with high mechanical strength and stable connection. At the same time, the insulation impedance is optimized, which improves the reliability and service life of the piezoelectric stack in harsh working environment and meets the requirements for high reliability of equipment.

[0017] (3) The stacking structure of this application realizes the simultaneous completion of stacking and connection, eliminating the tedious and high-precision external welding or dispensing process, reducing the requirements for production equipment and operating skills. This integrated interconnection method makes the assembly process simpler and more efficient, which is conducive to realizing automated production, thereby improving production efficiency and reducing production costs. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a three-layer stacked three-dimensional structure of this utility model.

[0019] Figure 2 This is an exploded view of a three-layer stacked three-dimensional structure of this utility model. The left column of the figure is a top view and the right column is a bottom view.

[0020] Figure 3 This is a schematic diagram of a five-layer stacked three-dimensional structure of this utility model.

[0021] Figure 4 This is an exploded view of a five-layer stacked three-dimensional structure of this utility model. The left column of the figure is a top view and the right column is a bottom view.

[0022] Figure 5 This is a three-dimensional structural diagram of the first piezoelectric element of this utility model from both top and bottom view perspectives.

[0023] Figure 6 This is a three-dimensional structural diagram of the second piezoelectric element of this utility model from both top and bottom view perspectives.

[0024] Figure 7 This is a three-dimensional structural diagram of the third piezoelectric element of this utility model from both top and bottom view perspectives.

[0025] In the figure: 1. First piezoelectric element; 11. First electrode; 12. Second electrode; 2. Second piezoelectric element; 21. Third electrode; 22. Fourth electrode; 3. Third piezoelectric element; 31. Fifth electrode; 32. Sixth electrode; 4. Substrate; 41. Through hole. Detailed Implementation

[0026] The present application will be further described below with reference to specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0027] In the description of this application, it should be noted that the terms "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., which indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and should not be construed as limiting the specific protection scope of this application.

[0028] It should be noted that the terms "first," "second," etc., in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0029] The terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0030] In a preferred embodiment of this application, a piezoelectric ring stack includes at least one second piezoelectric sheet 2, such as... Figure 6 As shown, the second piezoelectric sheet 2 includes a substrate 4, a third electrode 21, and a fourth electrode 22. The third electrode 21 and the fourth electrode 22 are respectively disposed on the upper and lower sides of the substrate 4. A through hole 41 is provided in the middle of the substrate 4. The third electrode 21 extends to the inner sidewall of the through hole 41 to form an inner connection portion, and the fourth electrode 22 extends to the outer sidewall of the substrate 4 to form an outer connection portion. In the stacked state, the inner connection portion and the outer connection portion on the second piezoelectric sheet 2 are connected to the corresponding electrodes on the adjacent piezoelectric sheets to achieve parallel connection. The third electrode 21 is annular, and its outer diameter is configured to be smaller than the outer diameter of the substrate 4. The fourth electrode 22 is annular, and its inner diameter is configured to be larger than the diameter of the through hole 41.

[0031] This application extends electrodes to the inner wall of the through-hole 41 and the outer wall of the substrate 4 to form inner and outer connection portions. Parallel connections are achieved by interconnecting corresponding inner and outer connection portions between adjacent components during stacking. This structural design eliminates the need for external solder leads and complex conductive adhesive networks required by traditional structures, simplifying the structure and reducing the radial dimension occupied by the piezoelectric stack. This makes the entire stack structure more compact, meeting the application scenarios with high requirements for device miniaturization or micro-miniaturization. Because parallel connections are achieved by interconnecting corresponding inner and outer connection portions between adjacent components, no external solder joints are required. The use of connecting wires effectively avoids the risk of breakage due to fatigue under long-term high-frequency vibration, and also avoids the risk of short circuits. The inner and outer connecting parts in this application are part of the stacked structure, with high mechanical strength and stable connection. At the same time, the upper and lower sides of the substrate 4 are single electrodes, and the electrode connection of adjacent components is only achieved through the inner and outer connecting parts. Furthermore, the inner or outer diameter of the electrode on the mating surface is configured to deviate from the size of the substrate 4, thereby forming physical insulation, optimizing the insulation impedance, improving the reliability and service life of the piezoelectric stack in harsh working environments, and meeting the requirements for high reliability of the equipment.

[0032] like Figure 5 , Figure 7 As shown, based on the second piezoelectric sheet 2, a first piezoelectric sheet 1 can also be disposed on the piezoelectric annular stack. The first piezoelectric sheet 1 includes a substrate 4, a first electrode 11, and a second electrode 12. The first electrode 11 and the second electrode 12 are respectively disposed on the upper and lower sides of the substrate 4. A through hole 41 is provided in the middle of the substrate 4. The first electrode 11 extends to the outer side wall of the substrate 4, thereby forming an outer connection part. The second electrode 12 is annular, and its outer diameter is equal to the outer diameter of the third electrode 21. And / or the piezoelectric annular stack can also be provided with a third piezoelectric sheet 3. The third piezoelectric sheet 3 includes a substrate. 4. The fifth electrode 31 and the sixth electrode 32 are respectively disposed on the upper and lower sides of the substrate 4. A through hole 41 is provided in the middle of the substrate 4. The sixth electrode 32 extends to the inner wall of the through hole 41, thereby forming an inner connection part. The fifth electrode 31 is annular, and its inner diameter is equal to that of the fourth electrode 22. The second electrode 12 and the third electrode 21 have the same area. The fourth electrode 22 and the fifth electrode 31 have the same area. The first electrode 11 has the same area as the upper surface of the substrate 4. The sixth electrode 32 has the same area as the lower surface of the substrate 4.

[0033] The first piezoelectric sheet 1 and the third piezoelectric sheet 3 are characterized by having an electrode disposed on one side of the entire surface, and forming an electrode connection portion through the inner wall of the through hole 41 or the outer wall of the substrate 4 for connecting with the electrodes of adjacent components.

[0034] The specific structural configurations of the first piezoelectric sheet 1, the second piezoelectric sheet 2, and the third piezoelectric sheet 3 described above can realize various piezoelectric ring stack structures. Based on the piezoelectric ring stack of the above-mentioned piezoelectric sheets, the positive and negative poles are respectively connected to the outer wall of the substrate 4 through the inner side wall of the through hole 41. When connected to an external power source, wires can be led at the two end faces of the piezoelectric ring stack.

[0035] This application provides five specific piezoelectric toroidal stack structures: The first type of stacking is a three-layer stack, such as... Figures 1 to 2 As shown, the piezoelectric ring stack includes a first piezoelectric sheet 1, a third piezoelectric sheet 3, and a second piezoelectric sheet 2. When stacked, the first piezoelectric sheet 1 and the third piezoelectric sheet 3 are respectively placed on both sides of the second piezoelectric sheet 2. The second electrode 12 is connected to the third electrode 21. The first electrode 11 and the fourth electrode 22 are interconnected through corresponding external connecting parts. The fourth electrode 22 is connected to the fifth electrode 31. The sixth electrode 32 and the third electrode 21 are interconnected through corresponding internal connecting parts to achieve parallel connection.

[0036] The second type of stacking, such as Figures 3 to 4 As shown, based on the first stacking method, the number of second piezoelectric pieces 2 can be increased to increase the displacement output of the piezoelectric ring stack. Specifically, the piezoelectric ring stack includes a first piezoelectric piece 1, a third piezoelectric piece 3, and an odd number of second piezoelectric pieces 2. The number of second piezoelectric pieces 2 is three. When stacked, the first piezoelectric piece 1 and the third piezoelectric piece 3 are respectively placed at both ends of the piezoelectric ring stack. The second electrode 12 is connected to the third electrode 21 on the adjacent second piezoelectric piece 2. The first electrode 11 is interconnected with the fourth electrode 22 on the adjacent second piezoelectric piece 2 through corresponding external connection parts. The fifth electrode 31 is connected to the fourth electrode 22 on the adjacent second piezoelectric piece 2. The sixth electrode 32 is interconnected with the third electrode 21 on the adjacent second piezoelectric piece 2 through corresponding internal connection parts. The polarization directions of the adjacent second piezoelectric pieces 2 are opposite, and they are interconnected with the corresponding internal connection parts and the corresponding external connection parts to achieve parallel connection.

[0037] Based on this, the number of the second piezoelectric sheet 2 can be an odd number greater than three. The second piezoelectric sheet 2 are stacked in a positive-negative order to achieve a piezoelectric ring stack with a larger displacement output. The specific number of layers can be adjusted by those skilled in the art according to actual needs.

[0038] The third type of stack, the piezoelectric ring stack, includes a first piezoelectric sheet 1 and an even number of second piezoelectric sheets 2. The number of second piezoelectric sheets 2 is at least two. When stacking, the first piezoelectric sheet 1 is placed at one end of the piezoelectric ring stack. The second electrode 12 is connected to the third electrode 21 on the adjacent second piezoelectric sheet 2. The first electrode 11 is interconnected with the fourth electrode 22 on the adjacent second piezoelectric sheet 2 through corresponding external connection parts. The polarization directions of the adjacent second piezoelectric sheets 2 are opposite, and they are interconnected with the corresponding internal connection parts and the corresponding external connection parts to achieve parallel connection.

[0039] This stack does not require a third piezoelectric element 3. The second piezoelectric element 2, which is furthest from the first piezoelectric element 1, can be used as an end piece to achieve parallel connection.

[0040] The fourth type of stack, the piezoelectric ring stack, includes a third piezoelectric sheet 3 and an even number of second piezoelectric sheets 2. The number of second piezoelectric sheets 2 is at least two. When stacking, the third piezoelectric sheet 3 is placed at one end of the piezoelectric ring stack. The fifth electrode 31 is connected to the fourth electrode 22 on the adjacent second piezoelectric sheet 2. The sixth electrode 32 is interconnected with the third electrode 21 on the adjacent second piezoelectric sheet 2 through the corresponding internal connection part. The polarization directions of the adjacent second piezoelectric sheets 2 are opposite, and they are interconnected with the corresponding external connection parts through the corresponding internal connection parts to achieve parallel connection.

[0041] This stack does not require the first piezoelectric element 1. The second piezoelectric element 2, which is furthest from the third piezoelectric element 3, can be used as the end piece to achieve parallel connection.

[0042] The fifth type of stack, the piezoelectric ring stack, is formed by stacking an odd number of second piezoelectric pieces 2. The minimum number of second piezoelectric pieces 2 is three. The polarization directions of adjacent second piezoelectric pieces 2 are opposite, and they are interconnected with corresponding internal connecting parts and corresponding external connecting parts to achieve parallel connection.

[0043] This stack discards the first piezoelectric element 1 and the third piezoelectric element 3. The entire stack consists of only an odd number of second piezoelectric elements 2. The two second piezoelectric elements 2 located at both ends serve as two end pieces to achieve connection with external circuits.

[0044] In any of the above-mentioned stacked structures, all the piezoelectric elements are connected in a stable parallel manner through the inner and outer connecting parts. This connection structure has low resistance and fast response, which can ensure that the driving voltage is effectively applied to each piezoelectric element. Combined with the reasonable configuration of polarization direction, the entire stack can generate greater axial cumulative displacement and driving force, and has low operating voltage and high energy density.

[0045] It is also understood that the electrodes mentioned above can be coated with conductive paste. In actual production, each piezoelectric element is coated individually. Because the coating electrode thickness is small and the gap between adjacent piezoelectric elements is also small when stacked, electrical connection between adjacent piezoelectric elements after stacking can be achieved. However, in order to better ensure the conductivity, after stacking, the outer and inner walls of the entire stack are coated with conductive paste again to avoid open circuits due to errors. The specific coating method for the outer and inner walls can be complete coating or partial coating. The coating requirement is to ensure the electrical connection of the entire piezoelectric stack and avoid open circuits and short circuits. Those skilled in the art can adjust it according to actual needs.

[0046] The basic principles, main features, and advantages of this application have been described above. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely the principles of this application. Various changes and modifications can be made to this application without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection claimed by this application is defined by the appended claims and their equivalents.

Claims

1. A piezoelectric ring stack, characterized in that, The device includes at least one second piezoelectric element, which comprises a substrate, a third electrode, and a fourth electrode. The third electrode and the fourth electrode are respectively disposed on the upper and lower sides of the substrate. A through hole is provided in the middle of the substrate. The third electrode extends to the inner sidewall of the through hole to form an inner connection portion, and the fourth electrode extends to the outer sidewall of the substrate to form an outer connection portion. In a stacked state, the inner connection portion and the outer connection portion on the second piezoelectric element are connected to the corresponding electrodes on the adjacent piezoelectric elements to achieve parallel connection.

2. The piezoelectric ring stack as described in claim 1, characterized in that, The third electrode is annular, and its outer diameter is configured to be smaller than the outer diameter of the substrate. The fourth electrode is annular, and its inner diameter is configured to be larger than the diameter of the through hole.

3. The piezoelectric ring stack as described in claim 2, characterized in that, The piezoelectric annular stack is further provided with a first piezoelectric sheet, which includes a substrate, a first electrode, and a second electrode. The first electrode and the second electrode are respectively disposed on the upper and lower sides of the substrate. A through hole is provided in the middle of the substrate. The first electrode extends to the outer sidewall of the substrate to form an outer connection portion. The second electrode is annular, and its outer diameter is equal to the outer diameter of the third electrode. And / or the piezoelectric annular stack is further provided with a third piezoelectric sheet, which includes a substrate, a fifth electrode, and a sixth electrode. The fifth electrode and the sixth electrode are respectively disposed on the upper and lower sides of the substrate. A through hole is provided in the middle of the substrate. The sixth electrode extends to the inner sidewall of the through hole to form an inner connection portion. The fifth electrode is annular, and its inner diameter is equal to the inner diameter of the fourth electrode.

4. The piezoelectric ring stack as described in claim 3, characterized in that, The second electrode has the same area as the third electrode, and the fourth electrode has the same area as the fifth electrode.

5. A piezoelectric ring stack as described in claim 3, characterized in that, The area of ​​the first electrode is equal to that of the upper surface of the substrate, and the area of ​​the sixth electrode is equal to that of the lower surface of the substrate.

6. The piezoelectric ring stack as described in claim 3, characterized in that, The piezoelectric ring stack includes a first piezoelectric sheet, a third piezoelectric sheet, and a second piezoelectric sheet. When stacked, the first piezoelectric sheet and the third piezoelectric sheet are respectively placed on both sides of the second piezoelectric sheet. The second electrode is connected to the third electrode. The first electrode and the fourth electrode are interconnected through corresponding external connection parts. The fourth electrode is connected to the fifth electrode. The sixth electrode and the third electrode are interconnected through corresponding internal connection parts to achieve parallel connection.

7. A piezoelectric ring stack as described in claim 3, characterized in that, The piezoelectric ring stack includes a first piezoelectric sheet, a third piezoelectric sheet, and an odd number of second piezoelectric sheets, with the number of second piezoelectric sheets being greater than one. When stacked, the first piezoelectric sheet and the third piezoelectric sheet are respectively placed at both ends of the piezoelectric ring stack. The second electrode is connected to the third electrode on the adjacent second piezoelectric sheet. The first electrode is interconnected with the fourth electrode on the adjacent second piezoelectric sheet through a corresponding external connection part. The fifth electrode is connected to the fourth electrode on the adjacent second piezoelectric sheet. The sixth electrode is interconnected with the third electrode on the adjacent second piezoelectric sheet through a corresponding internal connection part. The polarization directions of adjacent second piezoelectric sheets are opposite, and they are interconnected through the corresponding internal connection parts and the corresponding external connection parts to achieve parallel connection.

8. A piezoelectric ring stack as described in claim 3, characterized in that, The piezoelectric ring stack includes a first piezoelectric sheet and an even number of second piezoelectric sheets, with a minimum of two second piezoelectric sheets. When stacked, the first piezoelectric sheet is placed at one end of the piezoelectric ring stack. The second electrode is connected to the third electrode on the adjacent second piezoelectric sheet. The first electrode is interconnected with the fourth electrode on the adjacent second piezoelectric sheet through corresponding external connecting parts. The polarization directions of adjacent second piezoelectric sheets are opposite, and they are interconnected through corresponding internal connecting parts and corresponding external connecting parts to achieve parallel connection.

9. A piezoelectric ring stack as described in claim 3, characterized in that, The piezoelectric ring stack includes a third piezoelectric element and an even number of second piezoelectric elements, with a minimum of two second piezoelectric elements. When stacked, the third piezoelectric element is placed at one end of the piezoelectric ring stack. The fifth electrode is connected to the fourth electrode on the adjacent second piezoelectric element. The sixth electrode is interconnected with the third electrode on the adjacent second piezoelectric element through a corresponding internal connection portion. The polarization directions of adjacent second piezoelectric elements are opposite, and they are interconnected with the corresponding external connection portion through the corresponding internal connection portion to achieve parallel connection.

10. A piezoelectric ring stack as described in claim 2, characterized in that, The piezoelectric ring stack is formed by stacking an odd number of second piezoelectric sheets, with a minimum of three second piezoelectric sheets. Adjacent second piezoelectric sheets have opposite polarization directions and are interconnected with corresponding inner connecting parts and corresponding outer connecting parts to achieve parallel connection.

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