An adjustable bandwidth bending transducer structure

Abstract

This invention relates to an adjustable bandwidth bending transducer structure, comprising a metal shell with elliptical cover plates at both ends. The metal shell and cover plates are similar in shape, and an outer covering layer is provided on the outer side of both the metal shell and cover plates. A sealing ring is provided between the metal shell and cover plates. The cover plates at both ends are fixedly connected by fixed support rods and fastening nuts. The interior of the metal shell is filled with ceramic crystal stacks, and a watertight connector is provided on the top of the cover plates. In this bending transducer structure, the support rods are moved from the outer periphery of the shell to the inner periphery. The support rods are rearranged and installed according to the gap position inside the transducer shell. The sealing rings provide watertightness and vibration isolation between the shell and the cover plates. Moving the support rods inside also reduces the overall size of the transducer. The transducer is integrally filled, sealing and fully covering the upper and lower end faces, leaving only the watertight connector for connection to the external cable, achieving overall watertightness.

Description

Technical Field

[0001] This invention relates to the field of underwater acoustic transducer acoustic array technology, specifically to a bending transducer structure with adjustable bandwidth. Background Technology

[0002] Due to advancements in submarine quieting technology, traditional passive sonar detection has become difficult. Long-range submarine detection necessitates the use of active sonar as an auxiliary means, making the research of low-frequency, high-power transmitting transducers one of the most crucial technologies for long-range active sonar. Bending-tension transducers are typical low-frequency, high-power transmitters. Due to their amplitude amplification effect, they possess advantages such as small size and light weight at the same frequency. Therefore, utilizing bending-tension transducers for low-frequency transmission has become a research hotspot both domestically and internationally.

[0003] Furthermore, broadband transducers offer significant advantages in signal transmission, reducing waveform distortion, increasing signal transmission rates, enhancing communication reliability and security, and lowering bit error rates. For the entire transceiver system, the increased transducer operating bandwidth also improves the array gain.

[0004] Specifically, the sensitivity curve of a transducer operating in single-frequency resonance (see attached diagram) Figure 1 The frequency difference between two frequencies that are 3dB below the maximum response is the bandwidth of the transducer.

[0005] Δf=f2-f1

[0006] Typically, the bandwidth of a transducer is determined by the mechanical Q. M Value to represent

[0007]

[0008] Existing conventional bending and tensioning transducers (with) Figure 2 During assembly, the transducer housing is fixed to the watertight cover plate using support rods around the perimeter. Grooves are cut along the upper and lower edges of the housing, and sealing rings are used to ensure watertightness and vibration isolation between the housing and the cover plate. The admittance curve is shown in the appendix. Figure 3 Its mechanical quality factor Q M It's around 4, which means the bandwidth is relatively narrow. Summary of the Invention

[0009] To solve the above-mentioned technical problems, the present invention provides an adjustable bandwidth bending transducer structure, including a metal shell, with cover plates at both ends of the metal shell. The cover plates are elliptical in shape, and the metal shell and cover plates are similar in shape. An outer covering layer is provided on the outside of the metal shell and the cover plates. A sealing ring is provided between the metal shell and the cover plates. The cover plates at both ends are fixedly connected by a fixed support rod and a fastening nut. The interior of the metal shell is filled with a ceramic crystal stack, and a watertight connector is provided on the top of the cover plate.

[0010] In one embodiment of the present invention, a prestressed screw is provided inside the metal shell. The prestressed screw is located on the plane where the focal point of the metal shell is located, and the prestress can be easily adjusted on this plane.

[0011] In one embodiment of the present invention, platforms are left at both ends of the metal shell for installing prestressed screws, ensuring that after the prestressed screws are installed, the outer covering layer completely covers the shape of the cover plate.

[0012] In one embodiment of the present invention, the watertight connector penetrates through the cover plate and the outer covering layer, and the through structure is necessary to connect the interior.

[0013] In one embodiment of the present invention, the watertight connector is located on the straight line where the focal point of the cover plate is located.

[0014] Compared with the prior art, the above-mentioned technical solution of the present invention has the following advantages: The bending transducer structure of the present invention moves the support rod from the outer periphery of the shell to the inner periphery of the shell. The support rod is rearranged and installed according to the gap position inside the transducer shell. The shell and cover plate are watertight and vibration isolated by a sealing ring. Placing the support rod inside also reduces the overall size of the transducer. The transducer is integrally filled, sealing and fully encapsulating the upper and lower end faces, leaving only the watertight connector position on the outside for connection with the external cable, thus achieving overall watertightness. Attached Figure Description

[0015] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0016] Figure 1 This is the bandwidth diagram of the transducer;

[0017] Figure 2 This is a schematic diagram of a general-purpose bending and tension transducer structure;

[0018] Figure 3 It is the admittance curve and transmitted voltage response of a general-purpose bending transducer;

[0019] Figure 4 This is a schematic diagram showing the position of the strut of the transducer described in this invention;

[0020] Figure 5 This is a schematic diagram of the bending and tension transducer proposed in this invention;

[0021] Figure 6 This is an assembly diagram of the transducer described in this invention;

[0022] Figure 7 These are the admittance curve and transmission voltage response of the transducer described in this invention.

[0023] As shown in the figure: 1. Metal shell, 2. Cover plate, 3. Outer covering layer, 4. Sealing ring, 5. Fixing strut, 6. Fastening nut, 7. Ceramic crystal stack, 8. Watertight connector, 9. Prestressed screw. Detailed Implementation

[0024] like Figure 6 As shown, this embodiment provides an adjustable bandwidth bending transducer structure, including a metal shell 1, with cover plates 2 at both ends of the metal shell 1. The cover plates 2 are elliptical in shape, and the metal shell 1 and cover plates 2 have similar shapes. An outer covering layer 3 is provided on the outside of the metal shell 1 and cover plates 2. A sealing ring 4 is provided between the metal shell 1 and cover plates 2. The cover plates 2 at both ends are fixedly connected by a fixing strut 5 and a fastening nut 6. The interior of the metal shell 1 is filled with a ceramic crystal stack 7, and a watertight connector 8 is provided on the top of the cover plate 2.

[0025] As an improvement, a prestressed screw 9 is provided inside the metal shell 1. The prestressed screw 9 is located on the plane where the focal point of the metal shell 1 is located, which facilitates the adjustment of the prestress.

[0026] As an improvement, platforms are left at both ends of the metal shell 1 for installing the prestressed screws 9, ensuring that the outer covering layer is completely covered with the same shape as the cover plate after the prestressed screws are installed.

[0027] As an improvement, the watertight connector 8 penetrates the cover plate 2 and the outer covering layer 5, allowing the internal structure to be connected.

[0028] As an improvement, the watertight connector 8 is located on the straight line where the focal point of the cover plate is located.

[0029] The working principle of this invention is as follows: By adjusting the preload applied by the fastening nut... Figure 6 It can form two resonant peaks while keeping the center frequency constant. Figure 7 This allows for bandwidth adjustment.

[0030] Working principle: When a preload is applied to the fastening nut, the sealing ring between the housing and the cover plate begins to compress to a certain extent. The cover plate and housing then come into contact and form a whole, generating a slightly lower resonant frequency. This creates two close resonant peaks with the original frequency, thus extending the operating frequency band. During implementation, the transducer's admittance curve can be measured in real time using an impedance analyzer. The process stops once the required two resonant peaks are reached. The mechanical quality factor of the transducer can generally be improved to around 2.5.

[0031] The external shape of the bending transducer proposed in this invention is shown in the attached figure. Figure 5 Assembly drawing as follows Figure 6 It mainly includes: ceramic crystal stack, metal shell, upper and lower cover plates, sealing ring, fixing support rod, fastening nut, watertight connector, and outer encapsulation injection layer.

[0032] First, the ceramic sheets are glued together to form a crystal stack, an insulating bushing is added to the inner hole, and a prestressing screw is used to apply a suitable amount of prestress. The elliptical shell is then expanded along its length by external force, the ceramic crystal stack is placed in position, and the external force is removed to fix it.

[0033] According to the appendix Figure 6 As shown, the watertight connector is fixed to the top cover plate.

[0034] According to the appendix Figure 6 Tighten the support rod to the lower cover plate, and then install the sealing ring on the metal casing and position it with the lower cover plate.

[0035] According to the appendix Figure 6 Connect the watertight connector to the ceramic crystal stack, position the top cover plate to the metal shell, tighten the fastening nut, and measure the admittance curve of the transducer using an impedance analyzer. Stop when the required two resonance peaks are reached.

[0036] The outer coating layer is injected as a whole through a mold.

[0037] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A tunable bandwidth extensional transducer structure comprising a metal housing (1), characterized in that: The metal shell (1) is provided with cover plates (2) at both ends. The cover plates (2) are elliptical. The metal shell (1) and the cover plates (2) are similar in shape. The outer sides of the metal shell (1) and the cover plates (2) are provided with an outer covering layer (3). A sealing ring (4) is provided between the metal shell (1) and the cover plates (2). The cover plates (2) at both ends are fixedly connected by a fixed support rod (5) and a fastening nut (6). The metal shell (1) is filled with ceramic crystal stacks (7). A watertight connector (8) is provided on the top of the cover plates (2). By adjusting the preload applied by the fastening nut (6), the cover plate (2) and the metal shell (1) are brought into contact and form a whole, generating a slightly lower resonant frequency, which forms two close resonant peaks with the original frequency, thereby expanding the working frequency band of the bending transducer structure; finally, by adjusting the preload of the fastening nut (6), the mechanical quality factor QM value of the bending transducer structure is made to reach 2.

5.

2. The bending and tension transducer structure according to claim 1, characterized in that: The metal shell (1) is provided with a prestressed screw (9) inside, and the prestressed screw (9) is located on the plane where the focal point of the metal shell (1) is located.

3. The bending and tension transducer structure according to claim 1, characterized in that: The metal casing (1) has platforms at both ends for installing prestressed screws (9).

4. The bending and tension transducer structure according to claim 1, characterized in that: The watertight connector (8) penetrates the cover plate (2) and the outer covering layer (3).

5. The bending and tension transducer structure according to claim 1, characterized in that: The watertight connector (8) is located on the straight line where the focal point of the cover plate is located.

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