A piezoelectric stack and a piezoelectric valve with the same
By using the parallel connection of carbon fiber substrates and ceramic sheets and the electrode misalignment design, the problem of uneven electric field in piezoelectric stacks in low-voltage systems is solved, achieving low-voltage drive and high reliability, and improving product lifespan.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NINGBO JIANLI ELECTRONICS
- Filing Date
- 2025-08-26
- Publication Date
- 2026-07-14
AI Technical Summary
Existing piezoelectric stacks have high driving voltages and uneven electric field distribution in low-voltage systems, which can easily cause local electric field concentration at the edges, leading to local electric field distortion and breakdown, thus affecting reliability and lifespan.
The design employs a stacked carbon fiber substrate and ceramic sheet, and reduces the driving voltage requirement and avoids electric field concentration by using overall parallel connection and staggered electrode arrangement, thereby improving electric field uniformity.
This achieves low-voltage drive and uniform electric field distribution, improving product reliability and lifespan while reducing drive power requirements.
Smart Images
Figure CN224503900U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of piezoelectric valve technology, and in particular discloses a piezoelectric stack and a piezoelectric valve plate having the piezoelectric stack. Background Technology
[0002] As the core driving element of piezoelectric valve plates, piezoelectric stacks are widely used in precision fluid control, micro-displacement adjustment, and active vibration control due to their advantages such as high displacement accuracy, fast response speed, and large output force. Traditional piezoelectric stacks are usually composed of multiple layers of piezoelectric ceramic sheets stacked or glued together by mechanical means, and generate cumulative displacement output through the inverse piezoelectric effect under the excitation of an external electric field.
[0003] However, existing piezoelectric stack structures still have some problems: Traditional piezoelectric stacks are stacked in series, which requires a high driving voltage, often hundreds or even thousands of volts, limiting their applicability in low-voltage systems. To adapt to low-voltage systems, piezoelectric stacks use parallel stacks, but the electrode connections between adjacent ceramic sheets in existing parallel piezoelectric stacks typically use a full-surface electrode parallel connection. Due to edge effects, this leads to uneven electric field distribution, easily causing local electric field concentration at the edges. Furthermore, manufacturing defects such as thickness differences are amplified under full-electrode conditions, making local electric field distortion more likely. In strong electric field regions, the ceramic material may prematurely polarize to saturation or even partially depolarize. Simultaneously, the strong electric field forces charges to seek shortcuts, leading to decreased insulation resistance, increased leakage current, and heat generation. During long-term operation, these high-electric-field regions are prone to dielectric breakdown. Once a point breaks down, a carbonization path is created, causing the entire device to short-circuit and fail, significantly impacting the long-term reliability and lifespan of the stack. Therefore, improvements are needed. Utility Model Content
[0004] The purpose of this application is to provide a piezoelectric stack.
[0005] Another object of this application is to provide a piezoelectric valve having the piezoelectric stack.
[0006] To achieve the above objectives, the technical solution adopted in this application is as follows: a piezoelectric stack, comprising: a carbon fiber substrate; and a ceramic sheet stack, wherein the ceramic sheet stack is bonded to the carbon fiber substrate, the ceramic sheet stack includes two end pieces and an intermediate layer group, one of the end pieces is fixed on the upper side of the intermediate layer group, and the other end piece is fixed between the intermediate layer group and the carbon fiber substrate, the intermediate layer group is fixed by a plurality of piezoelectric ceramic sheet units alternately stacked and fixed on opposite sides in sequence, after stacking, the electrodes of adjacent piezoelectric ceramic sheet units are staggered, and the two end pieces and the plurality of piezoelectric ceramic sheet units are all connected in parallel.
[0007] As a preferred embodiment, the piezoelectric ceramic sheet unit includes a ceramic substrate, a first conductive layer, and a second conductive layer. Both the first and second conductive layers are arranged in a three-dimensional layout and are centrally symmetrically disposed on the ceramic substrate. The first and second conductive layers are not connected. The first conductive layer extends from a first region on the upper surface of the ceramic substrate through a first side to a third region on the lower surface, forming a continuous conductor. The second conductive layer extends from a second region on the upper surface of the ceramic substrate through a second side to a fourth region on the lower surface, forming a continuous conductor.
[0008] Further preferably, the area of the first region is greater than the area of the second region, the area of the third region is less than the area of the fourth region, the area of the first region is equal to the area of the fourth region, and the area of the second region is equal to the area of the third region.
[0009] More preferably, during the stacking process, the first region on the piezoelectric ceramic sheet unit is bonded to the first region on the adjacent piezoelectric ceramic sheet unit, and the second region on the piezoelectric ceramic sheet unit is bonded to the second region on the adjacent piezoelectric ceramic sheet unit; or the third region on the piezoelectric ceramic sheet unit is bonded to the third region on the adjacent piezoelectric ceramic sheet unit, and the fourth region on the piezoelectric ceramic sheet unit is bonded to the fourth region on the adjacent piezoelectric ceramic sheet unit.
[0010] As a preferred embodiment, the end piece is provided with an end conductive layer, which extends from a fifth region on the inner surface of the end piece through a side surface, an outer surface, and another opposite side surface to a sixth region on the lower surface, forming a continuous conductor. The area of the fifth region is equal to the area of the first region, and the area of the sixth region is equal to the area of the second region.
[0011] More preferably, during the stacking process, the fifth region on the end piece is bonded to the first region on the piezoelectric ceramic sheet unit, and the sixth region on the end piece is bonded to the second region on the piezoelectric ceramic sheet unit; or the fifth region on the end piece is bonded to the fourth region on the piezoelectric ceramic sheet unit, and the sixth region on the end piece is bonded to the third region on the piezoelectric ceramic sheet unit.
[0012] As a preferred embodiment, the conductive materials of the first conductive layer, the second conductive layer, and the end conductive layer are carbon paste, silver paste, copper paste, or aluminum paste.
[0013] As a preferred embodiment, the thickness of the piezoelectric ceramic sheet unit is 0.025 mm to 0.08 mm.
[0014] As a preferred embodiment, the ceramic sheets are stacked in an odd number of layers, ranging from 5 to 25 layers.
[0015] A piezoelectric valve having any of the above-described piezoelectric stacks.
[0016] Compared with the prior art, the beneficial effects of this application are as follows:
[0017] This application achieves low-voltage driving while obtaining a more uniform internal electric field distribution through an overall parallel connection and staggered electrode design: all piezoelectric ceramic sheet units are electrically connected in parallel with the end plates, making the total working voltage of the stack equivalent to the working voltage of a single layer of ceramic, which greatly reduces the requirements for the driving power supply; at the same time, the electrodes of adjacent ceramic sheet units are staggered instead of covering the entire surface. This design effectively avoids the electric field concentration phenomenon caused by the edge effect in the traditional parallel structure with full surface electrodes, eliminates the risk of local electric field distortion and breakdown, and improves the reliability and service life of the product. Attached Figure Description
[0018] Figure 1 This is a three-dimensional structural diagram of the present invention.
[0019] Figure 2 This is an exploded three-dimensional view of the present invention.
[0020] Figure 3 This is an exploded three-dimensional view of the present invention.
[0021] Figure 4 This is a three-dimensional structural diagram of the upper side of the piezoelectric ceramic sheet unit of this utility model.
[0022] Figure 5 This is a three-dimensional structural diagram of the lower side of the piezoelectric ceramic sheet unit of this utility model.
[0023] Figure 6 This is a partially enlarged cross-sectional view of the three-dimensional structure of the piezoelectric ceramic sheet unit of this utility model.
[0024] Figure 7 This is a schematic diagram of various regions on the ceramic substrate of this utility model.
[0025] Figure 8 This is a schematic diagram of the various regions on the end piece of this utility model.
[0026] In the figure: 1. Carbon fiber substrate; 2. Ceramic sheet stack; 21. End piece; 211. Fifth region; 212. Sixth region; 23. Intermediate layer group; 231. Piezoelectric ceramic sheet unit; 2311. First conductive layer; 2312. Second conductive layer; 2313. Ceramic substrate; 23131. First region; 23132. Second region; 23133. Third region; 23134. Fourth region. Detailed Implementation
[0027] 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.
[0028] In the description of this application, it should be noted that the directional terms such as "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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. They should not be construed as limiting the specific protection scope of this application.
[0029] 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.
[0030] 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.
[0031] A preferred embodiment of this application, such as Figures 1 to 8 As shown, a piezoelectric stack includes: a carbon fiber substrate 1; a ceramic sheet stack 2, the ceramic sheet stack 2 being bonded to the carbon fiber substrate 1, the ceramic sheet stack 2 including two end pieces 21 and an intermediate layer group 23, one end piece 21 being fixed on the upper side of the intermediate layer group 23, and the other end piece 21 being fixed between the intermediate layer group 23 and the carbon fiber substrate 1, the intermediate layer group 23 being fixed by a plurality of piezoelectric ceramic sheet units 231 being stacked alternately on the front and back sides in sequence, after stacking, the electrodes of adjacent piezoelectric ceramic sheet units 231 are staggered, and the two end pieces 21 and the plurality of piezoelectric ceramic sheet units 231 are all connected in parallel.
[0032] This application achieves low-voltage driving while obtaining a more uniform internal electric field distribution through an overall parallel connection and electrode misalignment design: all piezoelectric ceramic sheet units 231 are electrically connected in parallel with the end piece 21, making the total working voltage of the stack equivalent to the working voltage of a single layer of ceramic, which greatly reduces the requirements for the driving power supply; at the same time, the electrodes of adjacent ceramic sheet units are arranged in a misaligned manner instead of covering the entire surface. This design effectively avoids the electric field concentration phenomenon caused by the edge effect in the traditional parallel structure using full-surface electrodes, eliminates the risk of local electric field distortion and breakdown, and improves the reliability and service life of the product.
[0033] Structurally, the intermediate layer group 23 of this application adopts alternating layers of piezoelectric ceramic sheet units 231 on both sides. By rationally designing the electrode structure on the piezoelectric ceramic sheet units 231, parallel connection can be achieved through the bonding of the front and back sides, while ensuring the staggered arrangement of the electrodes. Specifically, this embodiment provides the design of one electrode: as follows Figures 4 to 7 As shown, the piezoelectric ceramic sheet unit 231 includes a ceramic substrate 2313, a first conductive layer 2311, and a second conductive layer 2312. Both the first conductive layer 2311 and the second conductive layer 2312 are arranged in a three-dimensional layout and are centrally symmetrically disposed on the ceramic substrate 2313. The first conductive layer 2311 and the second conductive layer 2312 are not connected. The first conductive layer 2311 extends from a first region 23131 on the upper surface of the ceramic substrate 2313 through a first side surface to a third region 23133 on the lower surface, forming a continuous conductor. The second conductive layer 2312 extends from the second region 23132 on the upper surface of the ceramic substrate 2313 through the second side to the fourth region 23134 on the lower surface, forming a continuous conductor. The area of the first region 23131 is larger than the area of the second region 23132, the area of the third region 23133 is smaller than the area of the fourth region 23134, the area of the first region 23131 is equal to the area of the fourth region 23134, and the area of the second region 23132 is equal to the area of the third region 23133.
[0034] It is understandable that the first conductive layer 2311 and the second conductive layer 2312 are centrally symmetrical in space. This ensures that the two piezoelectric ceramic sheet units 231 are connected in parallel when the front and back are bonded together. At the same time, in order to ensure the staggered arrangement of the electrodes in space, the area of the first region 23131 is designed to be larger than the area of the second region 23132, and the area of the third region 23133 is larger than the area of the fourth region 23134. In this way, the electrodes are staggered in space. This design can achieve the beneficial effects of this application.
[0035] Based on the design of the first conductive layer 2311 and the second conductive layer 2312 described above, in order to ensure accuracy during stacking, the following requirements must be followed: during stacking, the first region 23131 on the piezoelectric ceramic sheet unit 231 is bonded to the first region 23131 on the adjacent piezoelectric ceramic sheet unit 231, and the second region 23132 on the piezoelectric ceramic sheet unit 231 is bonded to the second region 23132 on the adjacent piezoelectric ceramic sheet unit 231; or the third region 23133 on the piezoelectric ceramic sheet unit 231 is bonded to the third region 23133 on the adjacent piezoelectric ceramic sheet unit 231, and the fourth region 23134 on the piezoelectric ceramic sheet unit 231 is bonded to the fourth region 23134 on the adjacent piezoelectric ceramic sheet unit 231.
[0036] The bonding method described above ensures the correspondence of the electrode areas and avoids the risk of short circuits between electrodes due to operational errors.
[0037] In this embodiment, as Figure 8 As shown, an end conductive layer is provided on the end piece 21. The end conductive layer extends from the fifth region 211 on the inner surface of the end piece 21 through the side surface, the outer surface, and another opposite side surface to the sixth region 212 on the lower surface, forming a continuous conductor. The area of the fifth region 211 is equal to the area of the first region 23131, and the area of the sixth region 212 is equal to the area of the second region 23132.
[0038] To achieve the effect of parallel connection of the entire ceramic sheet stack 2, a fifth region 211 and a sixth region 212 are designed on the end piece 21. The area of the fifth region 211 is equal to the area of the first region 23131, and the area of the sixth region 212 is equal to the area of the second region 23132. This allows for corresponding connection when connected to the intermediate layer group 23, ensuring complete adaptation of the electrode areas. Specifically, during stacking, the fifth region 211 on the end piece 21 is bonded to the first region 23131 on the piezoelectric ceramic sheet unit 231, and the sixth region 212 on the end piece 21 is bonded to the second region 23132 on the piezoelectric ceramic sheet unit 231; or the fifth region 211 on the end piece 21 is bonded to the fourth region 23134 on the piezoelectric ceramic sheet unit 231, and the sixth region 212 on the end piece 21 is bonded to the third region 23133 on the piezoelectric ceramic sheet unit 231.
[0039] The conductive materials of the first conductive layer 2311, the second conductive layer 2312, and the end conductive layer can be one or a combination of carbon paste, silver paste, copper paste, or aluminum paste. Of course, those skilled in the art can also choose other conductive materials.
[0040] For example, in one embodiment, carbon paste is selected as the conductive material. The piezoelectric ceramic sheet unit 231 and the end piece 21 are coated with carbon paste according to the electrode design in this application. Then they are glued together to form a complete ceramic sheet stack 2, and then glued to the carbon fiber substrate 1 to form a piezoelectric stack.
[0041] In this embodiment, the thickness of the piezoelectric ceramic sheet unit 231 is 0.025mm to 0.08mm, and the ceramic sheet stack 2 is an odd number of stacks, with the number of stacks ranging from 5 to 25.
[0042] This application also provides a piezoelectric valve plate having any of the above-described piezoelectric stacks.
[0043] 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 stack, characterized in that, include: Carbon fiber substrate; The ceramic sheets are stacked and bonded to the carbon fiber substrate. The ceramic sheet stack includes two end pieces and an intermediate layer group. One end piece is fixed on the upper side of the intermediate layer group, and the other end piece is fixed between the intermediate layer group and the carbon fiber substrate. The intermediate layer group is fixed by a plurality of piezoelectric ceramic sheet units stacked alternately on both sides in sequence. After stacking, the electrodes of adjacent piezoelectric ceramic sheet units are staggered. The two end pieces and the plurality of piezoelectric ceramic sheet units are all connected in parallel.
2. The piezoelectric stack as described in claim 1, characterized in that, The piezoelectric ceramic sheet unit includes a ceramic substrate, a first conductive layer, and a second conductive layer. Both the first conductive layer and the second conductive layer are arranged in a three-dimensional layout and are centrally symmetrically disposed on the ceramic substrate. The first conductive layer and the second conductive layer are not connected. The first conductive layer extends from a first region on the upper surface of the ceramic substrate through a first side to a third region on the lower surface, forming a continuous conductor. The second conductive layer extends from a second region on the upper surface of the ceramic substrate through a second side to a fourth region on the lower surface, forming a continuous conductor.
3. The piezoelectric stack as described in claim 2, characterized in that, The area of the first region is greater than the area of the second region, the area of the third region is less than the area of the fourth region, the area of the first region is equal to the area of the fourth region, and the area of the second region is equal to the area of the third region.
4. A piezoelectric stack as described in claim 2, characterized in that, During stacking, the first region on the piezoelectric ceramic sheet unit is bonded to the first region on the adjacent piezoelectric ceramic sheet unit, and the second region on the piezoelectric ceramic sheet unit is bonded to the second region on the adjacent piezoelectric ceramic sheet unit; or the third region on the piezoelectric ceramic sheet unit is bonded to the third region on the adjacent piezoelectric ceramic sheet unit, and the fourth region on the piezoelectric ceramic sheet unit is bonded to the fourth region on the adjacent piezoelectric ceramic sheet unit.
5. A piezoelectric stack as described in claim 3, characterized in that, The end piece is provided with an end conductive layer, which extends from the fifth region on the inner surface of the end piece through the side surface, the outer surface, and another opposite side surface to the sixth region on the lower surface, forming a continuous conductor. The area of the fifth region is equal to the area of the first region, and the area of the sixth region is equal to the area of the second region.
6. A piezoelectric stack as described in claim 5, characterized in that, During stacking, the fifth region on the end piece is bonded to the first region on the piezoelectric ceramic sheet unit, and the sixth region on the end piece is bonded to the second region on the piezoelectric ceramic sheet unit; or the fifth region on the end piece is bonded to the fourth region on the piezoelectric ceramic sheet unit, and the sixth region on the end piece is bonded to the third region on the piezoelectric ceramic sheet unit.
7. A piezoelectric stack as described in claim 5, characterized in that, The conductive materials of the first conductive layer, the second conductive layer and the end conductive layer are carbon paste, silver paste, copper paste or aluminum paste.
8. A piezoelectric stack as described in claim 1, characterized in that, The thickness of the piezoelectric ceramic sheet unit is 0.025mm to 0.08mm.
9. A piezoelectric stack as described in claim 1, characterized in that, The ceramic sheets are stacked in an odd number of layers, ranging from 5 to 25 layers.
10. A piezoelectric valve plate, characterized in that, Includes the piezoelectric stack as described in any one of claims 1-9.