Small slotted cymbal transducer based on textured ceramic

Abstract

The invention relates to a small slotted cymbal transducer based on texture ceramics, and belongs to the technical field of underwater acoustic transducers. Comprising metal end caps and piezoelectric ceramics, the metal end caps are symmetrically arranged on the two sides of the piezoelectric ceramics, the piezoelectric ceramics are wafers, and the piezoelectric ceramics are made of textured ceramics. Miniaturization and light weight of the transducer are achieved, higher output displacement and sound pressure are achieved, wider working bandwidth is achieved, lower driving voltage is achieved, and the overall performance is remarkably improved.

Description

Technical Field

[0001] The invention relates to a textured ceramic transducer, belonging to the technical field of underwater acoustic transducers. Background Art

[0002] The transducer is a high-performance piezoelectric composite structure transducer, which is characterized by a unique composite design of arched metal end caps and piezoelectric ceramics. This structure significantly improves the displacement output and energy conversion efficiency through the mechanical amplification effect, can achieve large amplitude vibration at low voltage, and has wide-band response characteristics. For example: the publication number is CN205847129U, and the invention is named a piezoelectric road transducer structure with high energy conversion rate. Its technical solution discloses that the multi-directional stress conversion device is a multi-layer structure, and the metal end caps of the upper and lower layers and the rectangular piezoelectric ceramic plates of the middle layer are assembled into a sphere, which realizes the conversion of multi-directional deformation energy of the road surface into electrical energy and improves the energy conversion efficiency; however, the vibration mode of the rectangular piezoelectric ceramic plate is more complex. According to its length, width, height dimensions and excitation method, there may be multiple vibration modes, such as expansion and contraction along the length direction, expansion and contraction along the width direction, thickness vibration or bending vibration, etc. Its vibration is no longer axial. Therefore, when rectangular ceramics vibrate or are subjected to stress, stress concentration is likely to occur at their edges, especially at their corners, affecting their durability or stability under strong drive. In addition, their role in the "multi-directional stress conversion device" is more focused on collecting mechanical stress in the environment from different directions and converting it into electrical energy as efficiently as possible for road energy collection. Their shape is chosen to better match the specific stress application method or energy collection structure. If rectangular piezoelectric ceramics are used to make Cymbal transducers, potential problems such as complex vibration modes, low coupling efficiency with metal caps, uneven displacement amplification, and irregular acoustic characteristics will be encountered. Rectangular piezoelectric ceramic plates are designed for specific energy collection application scenarios. Their working principles and goals are different from those of Cymbal acoustic transducers, so they are not suitable for Cymbal-like sound radiation units. The publication number is CN112427284B, and the name of the invention is cymbal-type piezoelectric ceramic composite transducer and its transducer forming method. Its technical solution discloses that the clamping area includes a cavity area and a bonding area, and the diameter of the piezoelectric ceramic disc is smaller than the diameter of the cymbal-shaped metal end cap, and a first adhesive layer is provided in the bonding area and resistance wires are arranged at intervals; the piezoelectric ceramic disc is filled with a second adhesive layer in the circumferential direction. The present invention is used to complete the function of the transducer and avoid the cymbal-shaped metal end cap from easily detaching; however, since the diameter of its piezoelectric ceramic disc is smaller than the cymbal-shaped metal end cap, axial center deviation is likely to occur during the installation process, and its bonding area encapsulates the piezoelectric ceramic disc inside, which is not easy to observe and detect. In "Giving Sonar Systems a Fresh Look: New Underwater Acoustic Transducers and New Transducer Technologies", Mo Xiping proposed a cymbal-shaped transducer and an 8-element array, which are made of a PZT piezoelectric ceramic disc bonded together with a pair of metal caps. However, the piezoelectric performance and thermal stability of PZT are poor, and the metal end caps are easy to fall off, affecting long-term working stability and reliability.

[0003] Therefore, it is urgent to propose a small slotted cymbal transducer based on textured ceramics to solve the above technical problems. Summary of the Invention

[0004] To address the aforementioned issues, a small slotted cymbal transducer based on textured ceramics is provided. A brief overview of the invention is provided below to provide a basic understanding of certain aspects of the invention. It should be understood that this overview is not an exhaustive overview of the invention. It is not intended to identify key or important aspects of the invention, nor is it intended to limit the scope of the invention.

[0005] The technical solution of the present invention:

[0006] A small slotted cymbal transducer based on textured ceramics comprises metal end caps and piezoelectric ceramics. The metal end caps are symmetrically arranged on both sides of the piezoelectric ceramics. The piezoelectric ceramics are discs made of textured ceramics.

[0007] Preferably, the diameter of the piezoelectric ceramic is equal to the diameter of the metal end cap.

[0008] Preferably, the metal end cap is a cymbal-shaped metal end cap.

[0009] Preferably, the side surface of the metal end cap has a slit.

[0010] Preferably, the gap is in a corrugated or straight shape.

[0011] Preferably, the plurality of slits are arranged in a circular array.

[0012] Preferably, the diameter of the piezoelectric ceramic is 10 mm and the thickness is 1 mm.

[0013] Preferably, the wall thickness of the metal end cap is 0.3 mm, the top diameter of the cavity of the metal end cap is 2 mm, the bottom diameter of the cavity of the metal end cap is 9 mm, the cavity height of the metal end cap is 0.6 mm, and the diameter of the connecting end of the metal end cap is 10 mm.

[0014] Preferably, the number of the slits is twelve, the width of the slits is 0.2 mm, and the slits are opened from one end to the other end of the side surface.

[0015] Preferably, the piezoelectric ceramic is waterproofed using a waterproof membrane, and the coaxially arranged metal end cap and the piezoelectric ceramic are connected using epoxy resin.

[0016] The present invention has the following beneficial effects:

[0017] 1. This invention achieves miniaturization and lightweighting of the transducer: Because textured ceramics have higher energy density and conversion efficiency, the size and weight of piezoelectric elements can be significantly reduced while achieving the same performance as traditional PZT ceramic transducers. Conversely, higher performance can be achieved within the same size. Research has shown that composite rod transducers using textured ceramics can be approximately 59% smaller in volume and 50% lighter in weight than PZT transducers of the same size, while maintaining comparable acoustic performance. This is particularly beneficial for the design of miniaturized Cymbal transducers.

[0018] 2. The present invention has higher output displacement and sound pressure: The working principle of the Cymbal transducer is to convert the axial expansion and contraction of the piezoelectric ceramic into a volume change of the cavity or a bending vibration of the metal cap through the lever amplification effect of the cymbal-shaped metal cap; the higher d33 value of the textured ceramic means that under the same electric field excitation, the ceramic sheet itself can produce a larger axial displacement; this larger initial displacement is amplified by the slit Cymbal structure, which will cause the metal cap to produce a larger vibration displacement, thereby radiating higher sound pressure or having higher sensitivity when receiving.

[0019] 3. The present invention has a wider operating bandwidth: A higher electromechanical coupling coefficient generally means that the transducer can achieve a wider operating bandwidth; this is an important advantage for applications that need to cover a certain frequency range.

[0020] 4. The present invention has a lower driving voltage: Due to the improvement of piezoelectric performance, a lower driving voltage may be required to achieve the same output level, which helps to simplify the driving circuit design and reduce power consumption.

[0021] 5. The specific advantages of the present invention for the slotted Cymbal: the "slotted" design optimizes the displacement amplification ratio, resonant frequency or bandwidth of the Cymbal transducer; the textured ceramic provides an "engine" with better performance, and its larger intrinsic displacement and energy conversion efficiency can make full use of the advantages of the slotted structure, thereby achieving a significant improvement in overall performance.

[0022] 6. Improve reliability and durability: It can effectively solve the problem of cymbal-shaped metal end caps easily falling off. Textured ceramics use their better temperature stability and potentially lower mechanical losses to improve the long-term working stability and reliability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The schematic diagram of the structure of a small slotted cymbal transducer based on textured ceramics;

[0024] Figure 2 is a schematic diagram of the structure of the metal end cap;

[0025] Figure 3is a top view of the metal end cap;

[0026] Figure 4 is a perspective view of a metal end cap;

[0027] Figure 5 A cross-sectional view of a small slotted cymbal transducer based on textured ceramics;

[0028] Figure 6 Comparison of the emission voltage response level of the cymbal transducer of the present invention and that of ordinary piezoelectric ceramics;

[0029] Figure 7 The characteristic frequency comparison between the cymbal transducer of the present invention and that of ordinary piezoelectric ceramics is shown;

[0030] Figure 8 This is a comparison diagram of the emission response of the present invention.

[0031] In the figure, 1-metal end cap, 2-piezoelectric ceramic, 11-gap. DETAILED DESCRIPTION

[0032] To make the objectives, technical solutions, and advantages of the present invention more clearly apparent, the present invention is described below using specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely illustrative and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present invention.

[0033] Specific implementation method 1: Combination Figure 1-7The present embodiment is described. A small slotted cymbal transducer based on textured ceramics in the present embodiment includes a metal end cap 1 and a piezoelectric ceramic 2. The metal end cap 1 is symmetrically arranged on both sides of the piezoelectric ceramic 2. The piezoelectric ceramic 2 is a disc, and the material of the piezoelectric ceramic 2 is textured ceramic. Textured ceramics are a type of ceramic material with a specific crystal orientation. The grains are preferentially arranged along a specific direction, thereby exhibiting anisotropic physical and mechanical properties. The structure of this type of ceramic is more stable and the piezoelectric properties are better. Unlike the random orientation of traditional ceramics, its physical properties (such as mechanics, electricity, and thermal) show significant differences in different directions. It has higher bending strength and fracture toughness along the direction of grain arrangement, and its fatigue resistance is significantly enhanced. It performs well in the fields of piezoelectricity, thermoelectricity, ferroelectricity, etc. For example, the piezoelectric coefficient (d33) of textured piezoelectric ceramics can reach more than 1.5 times that of traditional ceramics, and the energy conversion efficiency is high. The slit Cymbal structure amplifies the initial displacement of the piezoelectric ceramic, which will cause the metal cap to produce a larger vibration displacement, thereby radiating a higher sound pressure or having a higher sensitivity when receiving. A higher electromechanical coupling coefficient usually means that the transducer can achieve a wider operating bandwidth, which is an important advantage for applications that need to cover a certain frequency range. Due to the improvement in piezoelectric performance, a lower driving voltage may be required to achieve the same output level, which helps to simplify the driving circuit design and reduce power consumption.

[0034] The diameter of the piezoelectric ceramic 2 is equal to the diameter of the connecting end of the metal end cap 1; direct flush contact enables more direct transmission of mechanical energy between the piezoelectric ceramic and the metal end cap, focusing on energy conversion efficiency, and potentially simpler assembly, focusing on precise alignment and bonding of the ceramic and the end cap. In the case of diameter matching, the bonding surface is primarily a planar interface between the ceramic and the end cap, and the integrity of this single bond is crucial. Although the geometry is simpler, it may concentrate stress on the bonding layer. However, the use of textured ceramics, which are renowned for their excellent mechanical and piezoelectric properties, can inherently provide better elasticity. The material of the piezoelectric ceramic 2 produces better temperature stability and potentially lower mechanical losses, helping to reduce additional stress caused by material performance degradation or overheating under high-power or long-term operating conditions, thereby potentially indirectly improving the long-term operating stability and reliability of the device, and ensuring the stability of the metal end cap and the textured ceramic.

[0035] Metal end cap 1 is a cymbal-shaped metal end cap. It not only provides stress protection but also allows for flexible optimization of the resonant frequency by adjusting the end cap parameters. This transducer combines high sensitivity with strong load capacity, demonstrating unique advantages in fields such as ultrasonic sensors, energy harvesting, underwater sonar, and medical ultrasound, and is particularly suitable for miniaturized, high-reliability applications.

[0036] The side of the metal end cap 1 has a slit-like gap 11. By opening the slit-like groove in the metal end cap to reduce the stiffness of the metal end cap, the characteristic frequency can be reduced when the metal end cap undergoes radial vibration. In this case, the cymbal transducer is smaller in size than an ordinary cymbal transducer, but the characteristic frequency remains at around 30 kHz and the emission voltage response level is higher, so the efficiency is greater than that of an ordinary cymbal transducer.

[0037] The gap 11 is a radially corrugated or linear through hole in a top view;

[0038] A plurality of slots 11 are arranged in a circular array. The slot arrangement enables a "slot" design, which optimizes the displacement amplification ratio, resonant frequency, or bandwidth of the Cymbal transducer. The textured ceramic provides an "engine" with improved performance. Its greater intrinsic displacement and energy conversion efficiency allow the advantages of the slotted structure to be more fully utilized. The combination of the two significantly improves overall performance. For example, the slotted structure is more dependent on the performance of the ceramic. High-performance textured ceramics can better match and drive this refined structural design.

[0039] The diameter of the piezoelectric ceramic 2 is 10 mm and the thickness is H1 = 1 mm. Since the characteristic frequency is related to the stiffness of the cymbal transducer, the stiffness of the metal end cap is reduced by lowering the characteristic frequency. By changing the local geometric shape of the metal end cap (such as gaps and thin-wall design), its stiffness is reduced, thereby reducing the overall stiffness of the system and lowering the resonant frequency.

[0040] The thin wall thickness of the metal end cap 1 is H2 = 0.3mm, the top diameter of the cavity of the metal end cap 1 is R2 = 2mm, the bottom diameter of the cavity of the metal end cap 1 is R3 = 9mm, the cavity height of the metal end cap 1 is H3 = 0.6mm, and the diameter of the connecting end of the metal end cap 1 is R1 = 10mm. When the annular piece at the connecting end of the metal end cap 1 and the piezoelectric ceramic 2 have the same diameter, the edge of the metal end cap 1 and the edge of the piezoelectric ceramic 2 can be aligned, which facilitates observation of the installation operation, and has high installation efficiency and precision, thereby ensuring uniform stress distribution, low vibration and noise, and avoiding the risk of functional failure.

[0041] There are twelve slots 11, each 0.2 mm wide, extending from one side surface to the other. A smaller cymbal transducer has a higher characteristic frequency. By improving the structure and combining textured ceramics with metal end caps, the performance of the cymbal transducer can be improved while reducing its size. Since reducing the size increases the resonant frequency, the metal end caps are also improved to reduce the characteristic frequency of the cymbal transducer while increasing the overall toughness of the transducer. This results in a smaller size, higher power, and higher efficiency than an ordinary cymbal transducer. Studies have shown that a composite rod transducer using textured ceramics can achieve a volume reduction of approximately 59% and a weight reduction of approximately 50% compared to a PZT transducer of the same size while maintaining comparable acoustic performance. This is particularly advantageous for miniaturized cymbal transducer design, enabling a cymbal transducer with a characteristic frequency of 30 kHz in a small size.

[0042] The piezoelectric ceramic 2 is waterproofed with a waterproof film, and the coaxially arranged metal end cap 1 and the piezoelectric ceramic 2 are bonded with epoxy resin, and the bonding position of the piezoelectric ceramic 2 and the metal end cap is not bonded with a waterproof film; under the premise of ensuring easy installation, the problem of the cymbal-shaped metal end cap being easy to fall off can be effectively solved, and the bonding process makes detection and observation convenient; although the textured ceramic itself does not directly solve the bonding problem, its better temperature stability and possibly lower mechanical loss help to reduce the additional stress caused by material performance degradation or overheating under high power or long-term working conditions, thereby indirectly improving the long-term working stability and reliability of the device; textured ceramics are applied to cymbal transducers to improve the performance of the cymbal transducer, and the characteristic frequency is reduced by structural design in the case of small size; the transducer has the advantages of small size, low frequency, and larger emission voltage response level;

[0043] like Figure 6 As shown in the figure, the slits in the metal end cap will reduce the emission voltage response level of the cymbal transducer. However, due to the excellent performance of the textured ceramic, the emission voltage response level of the improved cymbal transducer is slightly larger than that of the ordinary cymbal transducer.

[0044] like Figure 7 By comparing the characteristic frequencies of the cymbal transducer of the invention and that of ordinary piezoelectric ceramics, it can be concluded that after structural improvement, the characteristic frequency is reduced to a certain extent under the same size;

[0045] according to Figure 8 It can be seen that after the improvement, the resonant frequency is reduced, and the emission voltage response level is greatly improved;

[0046] The use of textured ceramics has greatly improved the emission voltage response level of the cymbal transducer and improved the performance of the cymbal transducer. At the same time, the structure of the metal end cap has been improved, which reduces the size and the characteristic frequency. The final characteristic frequency is about 36kHz, and the emission voltage response level is above 130dB. The improved cymbal transducer has high practical value and can be applied to ocean exploration, underwater communication and other aspects, greatly improving performance.

[0047] It should be noted that in the above embodiments, as long as the technical solutions are not contradictory, they can be permuted and combined. Those skilled in the art can exhaust all possibilities based on the mathematical knowledge of permutations and combinations. Therefore, the present invention will no longer describe the technical solutions after permutations and combinations one by one, but it should be understood that the technical solutions after permutations and combinations have been disclosed by the present invention.

[0048] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A small slotted cymbal transducer based on textured ceramics, comprising a metal end cap (1) and a piezoelectric ceramic (2), wherein the metal end cap (1) is symmetrically arranged on both sides of the piezoelectric ceramic (2), and characterized in that: The piezoelectric ceramic (2) is a disc, and the material of the piezoelectric ceramic (2) is textured ceramic.

2. A small slotted cymbal transducer based on textured ceramics according to claim 1, characterized in that: The diameter of the piezoelectric ceramic (2) is equal to the diameter of the metal end cap (1).

3. A small slotted cymbal transducer based on textured ceramics according to claim 1 or 2, characterized in that: The metal end cap (1) is a cymbal-shaped metal end cap.

4. The small slotted cymbal transducer based on textured ceramics according to claim 3, characterized in that: The side surface of the metal end cap (1) has a slit (11).

5. The small slotted cymbal transducer based on textured ceramics according to claim 4, characterized in that: The gap (11) is in a corrugated shape or a straight line shape.

6. The small slotted cymbal transducer based on textured ceramics according to claim 5, characterized in that: A plurality of slits (11) are arranged in a circular array.

7. The small slotted cymbal transducer based on textured ceramics according to claim 6, characterized in that: The diameter of the piezoelectric ceramic (2) is 10 mm and the thickness is 1 mm.

8. The small slotted cymbal transducer based on textured ceramics according to claim 7, characterized in that: The wall thickness of the metal end cap (1) is 0.3 mm, the top diameter of the cavity of the metal end cap (1) is 2 mm, the bottom diameter of the cavity of the metal end cap (1) is 9 mm, the cavity height of the metal end cap (1) is 0.6 mm, and the diameter of the connecting end of the metal end cap (1) is 10 mm.

9. The small slotted cymbal transducer based on textured ceramics according to claim 8, characterized in that: The number of the slits (11) is twelve, the width of the slits (11) is 0.2 mm, and the slits (11) are opened from one end to the other end of the side surface.

10. The small slotted cymbal transducer based on textured ceramics according to claim 8, characterized in that: The piezoelectric ceramic (2) is waterproofed using a waterproof membrane, and the coaxially arranged metal end cap (1) and the piezoelectric ceramic (2) are connected using epoxy resin.

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