Ultrasonic transducer capable of accurately regulating and controlling size of resonant cavity

Abstract

The utility model provides an ultrasonic transducer capable of accurately regulating and controlling the size of a resonant cavity, which relates to the technical field of transducers and comprises a shell, one side of the shell is movably connected with piezoelectric ceramics, one side of the piezoelectric ceramics is movably connected with an electrode plate, one side of the outer wall of the piezoelectric ceramics and one side of the outer wall of the electrode plate are provided with a regulating and controlling mechanism, and the regulating and controlling mechanism is connected with a power supply. The regulation and control mechanism comprises a sleeve movably connected to the outer walls of one sides of the piezoelectric ceramics and the electrode plates, a laser is fixedly connected to the outer wall of one side of the sleeve, an optical fiber sensor is fixedly connected to the outer wall of one side of the sleeve, and a plurality of refraction parts are annularly arrayed on one side of the inner wall of the sleeve. The utility model solves the problems that the existing transducer adopts mechanical adjustment and cannot be finely adjusted, the size of the device is larger, and the size of the resonant cavity cannot be adjusted since the piezoelectric ceramic is damaged due to local overheating during adjustment.

Description

Technical Field

[0001] This utility model relates to the field of transducer technology, and in particular to an ultrasonic transducer with precisely adjustable resonant cavity size. Background Technology

[0002] As a core component in fields such as medical imaging (e.g., 5MHz high-frequency B-mode ultrasound with axial resolution up to 0.3mm), industrial flaw detection (20MHz probes can detect Φ0.05mm microcracks), and sonar systems (detection distance up to 5000m), the stability of the resonant frequency of transducers directly determines the system's performance. According to the "2023 Global Ultrasonic Equipment Market Report," the global market size for piezoelectric ceramic-based ultrasonic transducers has reached US$4.76 billion, with wafer-level microsystems (EMS) transducers experiencing a compound annual growth rate exceeding 21%. However, the frequency shift (>±2.8kHz) caused by resonant cavity drift (±3μm) remains a major bottleneck limiting their application in high-precision scenarios. For example, CT 3D imaging systems require the frequency stability of the ultrasonic guidance probe to be <0.05% (IEC 60601-2-37 standard), but current technology cannot maintain this accuracy after 15 minutes of continuous operation (thermal deformation causes a frequency shift >0.12%).

[0003] Existing resonant cavity adjustment technology has three major drawbacks: First, traditional mechanical adjustment methods use a micro stepper motor to drive the set screw structure (repeatability ±1.5μm), which not only causes stress concentration inside the piezoelectric ceramic (leading to a 12-18% decrease in the electromechanical coupling coefficient), but also, under high-temperature conditions (>80℃), the difference in the thermal expansion coefficient of metal components (piezoelectric ceramic CTE 3.5×10⁻) further exacerbates the problem. 6 / ℃ vs Stainless Steel 17.3×10⁻ 6 / ℃), resulting in a 1.2μm-level dimensional deviation for every 10℃ increase in temperature; secondly, although existing laser fine-tuning technology uses a 1064nm pulsed laser (peak power density 1.5×10), 8 While point-to-point ablation was performed using W / cm², controlling the PZT-5H ceramic (Curie temperature 365℃) resulted in local temperature rises exceeding 250℃, with a temperature gradient of 1800℃ / mm at 0.5mm from the ablation point (JAP 112, 074903 data), inducing phase transformation tomography cracks (length >20μm). Thirdly, the closed-loop control scheme based on infrared thermal imaging (temperature measurement accuracy ±2℃) had a 200ms delay, making it impossible to match the 3.7×10⁻⁻⁶ piezoelectric ceramic in real time. 6The thermal expansion rate at ℃ (APL 119, 092902 data) results in a hysteresis of 0.08 μm in the resonant cavity size during dynamic tuning. More seriously, existing single-beam direct-fire schemes (spot diameter μm) cause a redistribution of surface charge density (charge displacement > 5 × 10¹³ e / cm²), leading to a decrease in the piezoelectric constant d. 33 The value decreased by 28% (APL Materials 8,041104 study). Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide an ultrasonic transducer with precisely adjustable resonant cavity size.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: an ultrasonic transducer with precisely adjustable resonant cavity size, comprising: a housing, a piezoelectric ceramic movably connected to one side of the housing, an electrode plate movably connected to one side of the piezoelectric ceramic, an adjustment mechanism provided on one side of the outer wall of the piezoelectric ceramic and the electrode plate, and an electrode body fixedly connected to one side of the outer wall of the adjustment mechanism;

[0006] The control mechanism includes a sleeve movably connected to the outer wall of one side of the piezoelectric ceramic and electrode sheet, a laser fixedly connected to the outer wall of one side of the sleeve, an optical fiber sensor fixedly connected to the outer wall of one side of the sleeve, and a plurality of refractive elements arranged in a ring array on one side of the inner wall of the sleeve.

[0007] In a preferred embodiment, a first threaded groove is formed on the outer wall of the housing near the piezoelectric ceramic. A mounting ring is movably connected to the outer wall of the housing away from the first threaded groove. An amplitude transformer is movably connected to the outer wall of the mounting ring away from the housing. A rear cover is movably connected to the outer wall of the piezoelectric ceramic away from the housing. The inner wall of the sleeve is fixedly connected to the outer wall of the rear cover. A second threaded groove is formed on the outer wall of the rear cover away from the piezoelectric ceramic. A threaded rod is threadedly connected to one side of the inner wall of the second threaded groove.

[0008] In a preferred embodiment, the threaded rod is connected to a first threaded groove on one side of the outer wall of the housing, and the housing and the rear cover are connected by the threaded rod.

[0009] In a preferred embodiment, multiple piezoelectric ceramics and electrode sheets are provided and located on one side of the housing and the rear cover.

[0010] In a preferred embodiment, the housing and the amplitude rod are movably connected by a mounting ring.

[0011] In a preferred embodiment, the electrode body is provided in two parts, and is respectively located on both sides of the sleeve.

[0012] In a preferred embodiment, the laser and fiber optic sensor on one side of the outer wall of the sleeve are respectively connected to the piezoelectric ceramic on one side of the inner wall of the sleeve, and the refractive element is located on one side of the inner wall of the sleeve and one side of the outer wall of the piezoelectric ceramic.

[0013] Compared with the prior art, the advantages and positive effects of this utility model are as follows:

[0014] 1. In use, this invention employs a laser to irradiate the piezoelectric ceramic, causing it to expand or deform slightly upon heating, thus adjusting the size of the resonant cavity. This non-contact heating method is more precise and stable than traditional mechanical adjustment methods, while avoiding losses caused by mechanical friction or contact. A fiber optic sensor monitors changes in the resonant cavity size, providing timely feedback on the laser irradiation effect to ensure the resonant cavity remains within the required size and frequency range. Feedback control allows for real-time adjustment of the laser output, ensuring system accuracy.

[0015] 2. In use, the multiple refractive elements on the inner wall of the sleeve refract the laser light, optimizing the irradiation area and achieving overall heating of the piezoelectric ceramic. This avoids the uneven temperature and thermal damage caused by localized laser irradiation. This uniform heating ensures more uniform micro-deformation of the piezoelectric ceramic, thereby effectively controlling the dimensional changes of the resonant cavity. By adjusting the laser light through the refractive elements, the piezoelectric ceramic can be heated comprehensively and uniformly, enhancing the controllability of thermal expansion and preventing material damage or performance degradation caused by localized overheating. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the external structure of an ultrasonic transducer with precisely adjustable resonant cavity size, provided by this utility model.

[0017] Figure 2 This is a schematic diagram of the disassembled structure of an ultrasonic transducer with precisely adjustable resonant cavity size, which is provided by this utility model.

[0018] Figure 3 This is a cross-sectional disassembly diagram of an ultrasonic transducer with precisely adjustable resonant cavity size, provided by this utility model.

[0019] Figure 4 A schematic diagram of the refractive element structure of an ultrasonic transducer with precisely adjustable resonant cavity size provided by this utility model.

[0020] Legend:

[0021] 1. Housing; 2. First threaded groove; 3. Piezoelectric ceramic; 4. Electrode plate; 5. Rear cover; 6. Second threaded groove; 7. Threaded rod; 8. Adjustment mechanism; 9. Electrode body; 10. Mounting ring; 11. Amplitude rod;

[0022] 81. Sleeve; 82. Laser; 83. Fiber optic sensor; 84. Refractive element. Detailed Implementation

[0023] To more clearly illustrate the overall concept of this utility model, a detailed description will be provided below with reference to the accompanying drawings and examples.

[0024] It should be noted that many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0025] Furthermore, it should be understood in the description of this utility model that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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. Therefore, they should not be construed as limitations on this utility model.

[0026] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral unit; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. However, specifying a direct connection indicates that the two main bodies at the connection point are not connected through a transitional structure, but are simply connected to form a whole through a connecting structure. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0027] In this utility model, unless otherwise expressly specified and limited, the first feature "on" or "below" the second feature may be in direct contact with the first and second features, or indirect contact through an intermediate medium. In the description of this specification, references to terms such as "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Example

[0028] like Figure 1-4 As shown, this utility model provides a technical solution: an ultrasonic transducer with precisely adjustable resonant cavity size, comprising: a housing 1, a piezoelectric ceramic 3 movably connected to one side of the housing 1, an electrode plate 4 movably connected to one side of the piezoelectric ceramic 3, an adjustment mechanism 8 provided on one side of the outer wall of the piezoelectric ceramic 3 and the electrode plate 4, and an electrode body 9 fixedly connected to one side of the outer wall of the adjustment mechanism 8.

[0029] The control mechanism 8 includes a sleeve 81 movably connected to the outer wall of one side of the piezoelectric ceramic 3 and the electrode plate 4. Two electrode bodies 9 are provided and are respectively provided on both sides of the sleeve 81. A laser 82 is fixedly connected to one side of the outer wall of the sleeve 81, and an optical fiber sensor 83 is fixedly connected to one side of the outer wall of the sleeve 81. Multiple refractive elements 84 are arranged in a ring array on one side of the inner wall of the sleeve 81. The laser 82 and the optical fiber sensor 83 provided on one side of the outer wall of the sleeve 81 are respectively connected to the piezoelectric ceramic 3 provided on one side of the inner wall of the sleeve 81, and the refractive elements 84 are provided on one side of the inner wall of the sleeve 81 and one side of the outer wall of the piezoelectric ceramic 3.

[0030] In this embodiment, a housing 1 is designed, with piezoelectric ceramics 3 and electrode plates 4 connected to one side of the housing 1. Multiple piezoelectric ceramics 3 and electrode plates 4 are provided and interconnected. A control mechanism 8 is provided on one side of the outer wall of the piezoelectric ceramics 3 and electrode plates 4. The control mechanism 8 includes a sleeve 81, with a laser 82 and an optical fiber sensor 83 fixedly connected to one side of the outer wall of the sleeve 81. The inner walls of the laser 82 and optical fiber sensor 83 are correspondingly connected to the outer walls of the piezoelectric ceramics 3 and electrode plates 4. Therefore, when the laser 82 is activated, it irradiates and heats the piezoelectric ceramics 3, causing slight thermal expansion or deformation, thereby affecting the size of the resonant cavity. The fiber optic sensor 83 can monitor changes in the size of the resonant cavity and then calculate whether the output of the laser 82 needs to be adjusted to further fine-tune the size of the resonant cavity, ensuring that the resonant cavity remains within the required size and frequency range. However, relying solely on a single laser 82 can only locally heat the piezoelectric ceramic 3, which may damage the piezoelectric ceramic 3 and make it impossible to control the size. Therefore, multiple refractive elements 84 are arranged in a ring array on one side of the inner wall of the sleeve 81. The refractive elements 84 adopt a trapezoidal shape, which can refract the laser beam irradiated by the sleeve 81, thereby heating the entire outer wall of the piezoelectric ceramic 3, thus completing the heating deformation and causing the size of the resonant cavity to change. This method features non-contact adjustment, fast response speed, and strong adaptability. By controlling the laser 82, high-precision adjustment can be achieved. Combined with the fiber optic sensor 83, which is very small in size and can be embedded in the resonant cavity, it has high sensitivity and high precision, which is conducive to achieving real-time adjustment. On both sides of the outer wall of the sleeve 81, there are electrode bodies 9. The electrode bodies 9 extend to one side of the inner wall of the sleeve 81 and are connected to the piezoelectric ceramic 3 and the electrode plate 4, thereby enabling the device to operate. Example

[0031] like Figure 1-3 As shown, a first threaded groove 2 is provided on the outer wall of the housing 1 near the piezoelectric ceramic 3. A mounting ring 10 is movably connected to the outer wall of the housing 1 away from the first threaded groove 2. An amplitude transformer 11 is movably connected to the outer wall of the mounting ring 10 away from the housing 1. The housing 1 and the amplitude transformer 11 are movably connected through the mounting ring 10. A rear cover 5 is movably connected to the outer wall of the piezoelectric ceramic 3 away from the housing 1. Multiple piezoelectric ceramics 3 and electrode plates 4 are provided and located on one side of the housing 1 and the rear cover 5. The inner wall of one side of the sleeve 81 is fixedly connected to the outer wall of one side of the rear cover 5. A second threaded groove 6 is provided on the outer wall of the rear cover 5 away from the piezoelectric ceramic 3. A threaded rod 7 is threadedly connected to one side of the inner wall of the second threaded groove 6. The threaded rod 7 is correspondingly connected to the first threaded groove 2 provided on one side of the outer wall of the housing 1. The housing 1 and the rear cover 5 are threadedly connected through the threaded rod 7.

[0032] In this embodiment, a first threaded groove 2 is provided on one side of the housing 1, and a rear cover 5 is connected to the other side of the piezoelectric ceramic 3 and the electrode plate 4. The rear cover 5 is provided with a second threaded groove 6, and a threaded rod 7 is threadedly connected to the inner wall of the second threaded groove 6. At this time, the rear cover 5 and the housing 1 can be threadedly connected by the threaded rod 7. The threaded rod 7 can pass through the piezoelectric ceramic 3 and the electrode plate 4 to connect with the housing 1. Thus, the piezoelectric ceramic 3 and the electrode plate 4 can be fixed by the housing 1, the rear cover 5 and the threaded rod 7. One end of the sleeve 81 can be fixedly connected to one side of the outer wall of the rear cover 5, and an amplitude transformer 11 is threadedly connected to the other side of the housing 1 by a mounting ring 10. This method can facilitate the disassembly and replacement of the device, thereby increasing the practicality of the device.

[0033] Working principle:

[0034] like Figure 1-4As shown, the working principle of this device is based on a method that combines laser heating with monitoring by a fiber optic sensor 83 to precisely adjust the deformation of the piezoelectric ceramic 3, thereby controlling the change in the size of the resonant cavity. The entire system achieves high-precision adjustment in a non-contact manner, is highly adaptable, and has the ability to respond quickly and adjust in real time. The core structure of the device consists of a housing 1, a piezoelectric ceramic 3, electrode plates 4, a control mechanism 8, and a laser 82. The piezoelectric ceramic 3 and electrode plates 4 are connected alternately to form an electrode array located on one side of the housing 1. On the outer wall of the piezoelectric ceramic 3 and electrode plates 4, the control mechanism 8 is responsible for precisely adjusting their shape and size. The control mechanism 8 includes a sleeve 81, on the outer wall of which the laser 82 and the fiber optic sensor 83 are fixed. The laser 82 can irradiate the piezoelectric ceramic 3 and cause slight thermal expansion or deformation of the piezoelectric ceramic 3 through heating. This change affects the size of the resonant cavity, thereby changing its operating frequency. At the same time, the fiber optic sensor 83 can monitor the size change of the resonant cavity in real time and feed the data back to the control system. When a dimensional deviation is detected, the system adjusts the output of the laser 82 to precisely regulate the temperature of the piezoelectric ceramic 3, ensuring that the size of the resonant cavity remains within the required range. To ensure uniform heating and avoid damage to the piezoelectric ceramic 3 due to localized overheating, multiple trapezoidal refractive elements 84 are provided on the inner wall of the sleeve 81. These refractive elements 84 can uniformly refract the laser beam onto the outer wall of the piezoelectric ceramic 3, thereby achieving heating of the entire surface area, making its deformation more uniform, and ensuring accurate control of the resonant cavity size. The structural design of the device also includes an electrode body 9, which is connected to the piezoelectric ceramic 3 and the electrode plate 4. The electrode body 9 forms an electrical connection with one side of the inner wall of the sleeve 81, ensuring the normal operation of the device. In addition, the rear cover 5 is connected to other parts of the device by threads, fixing the piezoelectric ceramic 3 and the electrode plate 4, ensuring the stability of the internal components of the device. A first threaded groove 2 is provided on one side of the housing 1, and a second threaded groove 6 is provided on the rear cover 5. The two are connected by a threaded rod 7, thereby fixing the internal structure. The threaded rod 7 can pass through the piezoelectric ceramic 3 and the electrode plate 4, further connecting to the housing 1, ensuring the stability of the entire device. Finally, to facilitate disassembly and replacement of the device, one end of the sleeve 81 can be fixed to the rear cover 5, while a mounting ring 10 is provided on the other side of the housing 1, which can be connected to the amplitude transformer 11 via threads. This design not only gives the device high-precision adjustment capability but also high convenience when maintenance or replacement is required. In summary, through the synergistic effect of laser heating and fiber optic sensor 83 monitoring, the device achieves high-precision and rapid adjustment of the piezoelectric ceramic 3, effectively controls the size change of the resonant cavity, and its structural design facilitates disassembly and maintenance, ensuring its efficient and stable long-term operation.

[0035] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the present invention (including the claims) is limited to these examples; within the framework of the present invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the present invention as described above, which are not provided in the details for the sake of brevity.

[0036] This utility model is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An ultrasonic transducer with precisely adjustable resonant cavity size, comprising a housing (1), characterized in that: A piezoelectric ceramic (3) is movably connected to one side of the housing (1), and an electrode plate (4) is movably connected to one side of the piezoelectric ceramic (3). An adjustment mechanism (8) is provided on one side of the outer wall of the piezoelectric ceramic (3) and the electrode plate (4), and an electrode body (9) is fixedly connected to one side of the outer wall of the adjustment mechanism (8). The control mechanism (8) includes a sleeve (81) movably connected to the outer wall of one side of the piezoelectric ceramic (3) and the electrode plate (4), a laser (82) is fixedly connected to one side of the outer wall of the sleeve (81), an optical fiber sensor (83) is fixedly connected to one side of the outer wall of the sleeve (81), and a plurality of refractive elements (84) are arranged in a ring on one side of the inner wall of the sleeve (81).

2. The ultrasonic transducer with precisely adjustable resonant cavity size according to claim 1, characterized in that: The outer wall of the housing (1) near the piezoelectric ceramic (3) has a first threaded groove (2). The outer wall of the housing (1) away from the first threaded groove (2) is movably connected to an mounting ring (10). The outer wall of the mounting ring (10) away from the housing (1) is movably connected to an amplitude rod (11). The outer wall of the piezoelectric ceramic (3) away from the housing (1) is movably connected to a rear cover (5). The inner wall of the sleeve (81) is fixedly connected to the outer wall of the rear cover (5). The outer wall of the rear cover (5) away from the piezoelectric ceramic (3) has a second threaded groove (6). The inner wall of the second threaded groove (6) is threadedly connected to a threaded rod (7).

3. The ultrasonic transducer with precisely adjustable resonant cavity size according to claim 2, characterized in that: The threaded rod (7) is connected to the first threaded groove (2) opened on one side of the outer wall of the housing (1), and the housing (1) and the rear cover (5) are connected by the threaded rod (7).

4. An ultrasonic transducer with precisely adjustable resonant cavity size according to claim 2, characterized in that: Multiple piezoelectric ceramics (3) and electrode sheets (4) are provided and are located on one side of the housing (1) and the rear cover (5).

5. An ultrasonic transducer with precisely adjustable resonant cavity size according to claim 2, characterized in that: The housing (1) and the amplitude rod (11) are movably connected by the mounting ring (10).

6. An ultrasonic transducer with precisely adjustable resonant cavity size according to claim 1, characterized in that: The electrode body (9) is provided in two parts, and is respectively located on both sides of the sleeve (81).

7. An ultrasonic transducer with precisely adjustable resonant cavity size according to claim 1, characterized in that: The laser (82) and fiber optic sensor (83) provided on one side of the outer wall of the sleeve (81) are respectively connected to the piezoelectric ceramic (3) provided on one side of the inner wall of the sleeve (81), and the refractive element (84) is provided on one side of the inner wall of the sleeve (81) and one side of the outer wall of the piezoelectric ceramic (3).

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