阅读说明：本技术 一种低频窄波束水声换能器 (Low-frequency narrow-beam underwater acoustic transducer ) 是由 张光斌 代志强 孟庆玉 于 2019-09-19 设计创作，主要内容包括：本发明属于水声换能器领域,具体涉及一种低频窄波束水声换能器,包括顶部设有开口的外壳,所述外壳开口处紧密连接有透声橡胶,所述透声橡胶下端面粘接有薄圆板,所述薄圆板的下端面固定连接有准周期结构换能器；所述准周期结构换能器连接有正极引线与负极引线一端,所述外壳的底部设有引出正极引线与负极引线的开孔,所述正极引线与负极引线的另一端套设有防水电缆；本装置通过选择不同的非压电材料可以获得不同谐振频率的换能器,通过调节薄圆板的直径,控制换能器谐振频率处的发射电压响应值与波束宽度,便于使用,造价低廉。(The invention belongs to the field of underwater acoustic transducers, and particularly relates to a low-frequency narrow-beam underwater acoustic transducer which comprises a shell with an opening at the top, wherein sound-transmitting rubber is tightly connected to the opening of the shell, a thin circular plate is bonded to the lower end surface of the sound-transmitting rubber, and a quasi-periodic structure transducer is fixedly connected to the lower end surface of the thin circular plate; the quasi-periodic structure transducer is connected with one end of a positive lead and one end of a negative lead, the bottom of the shell is provided with openings for leading out the positive lead and the negative lead, and the other ends of the positive lead and the negative lead are sleeved with waterproof cables; the device can obtain the transducers with different resonant frequencies by selecting different non-piezoelectric materials, and controls the response value of the transmitting voltage and the beam width at the resonant frequency of the transducer by adjusting the diameter of the thin circular plate, thereby being convenient to use and low in manufacturing cost.)

1. A low-frequency narrow-beam underwater acoustic transducer is characterized in that: the transducer comprises a shell (1) with an opening at the top, wherein sound-transmitting rubber (2) is tightly connected to the opening of the shell (1), a thin circular plate (4) is bonded to the lower end face of the sound-transmitting rubber (2), and a quasi-periodic structure transducer is fixedly connected to the lower end face of the thin circular plate (4); quasi-periodic structure transducer is connected with anodal lead wire (11) and negative pole lead wire (12) one end, the bottom of shell (1) is equipped with the trompil of drawing forth anodal lead wire (11) and negative pole lead wire (12), anodal lead wire (11) and the other pot head of negative pole lead wire (12) are equipped with waterproof cable.

2. The low-frequency narrow-beam underwater acoustic transducer of claim 1, characterized in that: the quasi-periodic structure transducer includes: the piezoelectric ceramic plate fixing device comprises an upper end post (5), a plurality of piezoelectric ceramic plates (6), a plurality of non-piezoelectric materials (7) and a lower end post (8), wherein a bolt hole is formed in the lower end face of the upper end post (5), the bolt hole is connected with a bolt (9), the bolt (9) is sequentially sleeved with the piezoelectric ceramic plates (6) and the non-piezoelectric materials (7) which are alternately arranged from top to bottom, the lower end of the bolt (9) is sleeved with the lower end post (8), and a fastening nut (10) matched with the bolt (9) is arranged below the lower end post (8); the piezoelectric ceramic pieces (6) and the non-piezoelectric materials (7) are of a quasi-periodic structure, the polarization directions of the adjacent piezoelectric ceramic pieces (6) are opposite, one surface of each piezoelectric ceramic piece (6) is connected with the positive lead (11), and the other surface of each piezoelectric ceramic piece is connected with the negative lead (12).

3. The low-frequency narrow-beam underwater acoustic transducer of claim 1, characterized in that: the shell (1) is filled with polyurethane foam (3) for positioning and suspending the quasi-periodic structure transducer.

4. The low-frequency narrow-beam underwater acoustic transducer of claim 1, characterized in that: the utility model discloses a waterproof cable, including shell (1), shell (13), sealed rubber lid (13) fixed connection is in shell (1) bottom, sealed rubber lid (13) are equipped with the via hole that supplies waterproof cable to stretch out.

5. The low-frequency narrow-beam underwater acoustic transducer of claim 1, characterized in that: the shell (1) is made of aluminum alloy.

6. The low-frequency narrow-beam underwater acoustic transducer of claim 1, characterized in that: the upper end column (5) is made of aluminum, and the lower end column (8) is made of steel.

7. The low-frequency narrow-beam underwater acoustic transducer of claim 1, characterized in that: the bolt (9) and the fastening nut (10) are made of steel.

8. The low-frequency narrow-beam underwater acoustic transducer of claim 1, characterized in that: the thin circular plate (4) is made of aluminum and has the thickness of 2 mm.

9. The low-frequency narrow-beam underwater acoustic transducer of claim 2, characterized in that: the piezoelectric ceramic piece (6) and the non-piezoelectric material (7) are both circular rings, the outer diameter of the piezoelectric ceramic piece is the same as the diameter of the upper end post (5) and the lower end post (8), and the piezoelectric ceramic piece (6) is made of PZT-4 piezoelectric ceramic.

Technical Field

The invention belongs to the field of underwater acoustic transducers, and relates to a low-frequency narrow-beam underwater acoustic transducer.

Background

With the continuous application of finite element analysis methods in transducer design, there are many new theories and new structures of underwater acoustic transducers, but piezoelectric transducers are still the focus of current underwater acoustic transducer research. Underwater acoustics mainly researches underwater sound emission, transmission, reception, processing and underwater information transmission technologies, can realize detection, positioning, identification, tracking, underwater communication and the like of underwater targets by using the transmission of sound waves in water, and has important significance for shipping, fish detection, development of submarine resources and the like. As quiet submarines are developed, underwater detection technology faces challenges, making transducers evolve toward low frequency, high power, broadband, and small size for portability. The low-frequency transducer is mainly designed into a bending vibration low-frequency transducer, a flextensional transducer, a cavity structure low-frequency transducer, an overflow type transducer and the like.

When underwater detection is carried out by using sound waves, the sound waves are generated by vibration of a transducer wafer, and the narrower the beam width of the sound waves, the more concentrated the sound field energy is, so that the narrow-beam transducer is designed to have better effects on improving the range and the precision of underwater detection and improving the imaging resolution. The beam width (directional opening angle) is an angle between directions corresponding to a reduction of the amplitude from the maximum value by 3dB, 6dB, etc., in the directional main lobe, and is referred to as-3 dB beam width, -6dB beam width, etc., respectively. The size of the beam width of the transducer is related to the size of the radiating surface of the transducer, and when the frequency is constant, the beam width of a radiating sound field generated by the transducer with a larger aperture is smaller; conversely, a smaller aperture corresponds to a larger beamwidth. By changing the vibration velocity distribution of the radiation surface of the transducer, the beam width of a radiation sound field of the transducer can be controlled, so that the smaller beam width is realized under the smaller aperture size.

Disclosure of Invention

In order to solve the above problems in the prior art, the present invention provides a low-frequency narrow-beam underwater acoustic transducer. The technical problem to be solved by the invention is realized by the following technical scheme:

a low-frequency narrow-beam underwater acoustic transducer comprises a shell with an opening at the top, wherein sound-transmitting rubber is tightly connected to the opening of the shell, a thin circular plate is bonded to the lower end face of the sound-transmitting rubber, and a quasi-periodic structure transducer is fixedly connected to the lower end face of the thin circular plate; the quasi-periodic structure transducer is connected with positive lead and negative lead one end, the bottom of shell is equipped with the trompil of drawing forth positive lead and negative lead, the other pot head of positive lead and negative lead is equipped with waterproof cable.

Further, the quasi-periodic structure transducer includes: the piezoelectric ceramic plate piezoelectric ceramic piezoelectric; the piezoelectric ceramic pieces and the non-piezoelectric materials are of a quasi-periodic structure, the polarization directions of the adjacent piezoelectric ceramic pieces are opposite, one surface of each piezoelectric ceramic piece is connected with the positive lead, and the other surface of each piezoelectric ceramic piece is connected with the negative lead.

Further, the interior of the housing is filled with polyurethane foam for positioning and suspending the quasi-periodic structure transducer.

Further, the below of shell bottom trompil is equipped with the sealing rubber lid, sealing rubber lid fixed connection is in the shell bottom, the sealing rubber lid is equipped with the via hole that supplies waterproof cable to stretch out.

Further, the shell is made of aluminum alloy.

Furthermore, the upper end column is made of aluminum, and the lower end column is made of steel.

Further, the bolt and the fastening nut are made of steel.

Furthermore, the thin circular plate is made of aluminum and has a thickness of 2 mm.

Furthermore, the piezoelectric ceramic piece and the non-piezoelectric material are both circular rings, the outer diameter of the piezoelectric ceramic piece is the same as the diameter of the upper end column and the diameter of the lower end column, and the piezoelectric ceramic piece is made of PZT-4 piezoelectric ceramic.

Compared with the prior art, the invention has the beneficial effects that:

the low-frequency narrow-beam underwater acoustic transducer provided by the invention longitudinally vibrates under the excitation of an external voltage signal and radiates acoustic energy outwards, and transducers with different resonant frequencies can be obtained by selecting different non-piezoelectric materials. The thin circular plate is added at the radiation end of the transducer, the longitudinal vibration of the transducer is transmitted to the thin circular plate to enable the thin circular plate to generate bending vibration, the transmission voltage response value and the beam width at the resonance frequency of the transducer are controlled by adjusting the diameter of the thin circular plate, the small-size underwater acoustic transducer with low frequency and narrow beams is realized, the whole structure and the manufacturing process are simple, and the cost is low.

Drawings

Fig. 1 is a schematic structural diagram of a low-frequency narrow-beam underwater acoustic transducer according to the present invention.

Fig. 2 is a diagram of the mode shape of a sandwich piezoelectric transducer.

Fig. 3 is a graph of the transmission voltage response of a sandwich piezoelectric transducer in water.

Fig. 4 is a directivity diagram of a sandwich piezoelectric transducer in water.

FIG. 5 is a diagram of the mode shape of a quasi-periodic structure transducer of the same dimensions when the non-piezoelectric material is aluminum.

FIG. 6 is a diagram of the mode shape of a co-dimensional quasi-periodic structure transducer when the non-piezoelectric material is steel.

FIG. 7 is a diagram of the mode shape of a quasi-periodic structure transducer of the same size when the non-piezoelectric material is polyimide.

FIG. 8 is a diagram of the mode shape of a quasi-periodic structure transducer of the same size when the non-piezoelectric material is nylon.

FIG. 9 is a graph of the response of the transmission voltage of a co-sized quasi-periodic structure transducer in water when the non-piezoelectric material is nylon.

Fig. 10 is a directivity diagram of a co-sized quasi-periodic structure transducer in water when the non-piezoelectric material is nylon.

Fig. 11 is a diagram of the mode of a low-frequency narrow-beam underwater acoustic transducer with a thin circular plate having a diameter of 57 mm.

Fig. 12 is a sound pressure diagram of a low-frequency narrow-beam underwater acoustic transducer in water when the diameter of a thin circular plate is 57 mm.

Fig. 13 is a graph of the sound pressure level of a low frequency narrow beam underwater acoustic transducer in water at a thin circular plate diameter of 57 mm.

Fig. 14 is a graph of the transmission voltage response of the low-frequency narrow-beam underwater acoustic transducer in water when the diameter of the thin circular plate is 57 mm.

Fig. 15 is a directivity diagram of a low-frequency narrow-beam underwater acoustic transducer in water when the diameter of the thin circular plate is 57 mm.

Fig. 16 is a graph of the transmission voltage response of the low-frequency narrow-beam underwater acoustic transducer in water when the diameter of the thin circular plate is 40 mm.

Fig. 17 is a directivity diagram of a low-frequency narrow-beam underwater acoustic transducer in water when the diameter of the thin circular plate is 40 mm.

Fig. 18 is a graph of the transmission voltage response of the low-frequency narrow-beam underwater acoustic transducer in water when the diameter of the thin circular plate is 50 mm.

Fig. 19 is a directivity diagram of a low-frequency narrow-beam underwater acoustic transducer in water when the diameter of a thin circular plate is 50 mm.

Fig. 20 is a graph of the transmission voltage response of the low-frequency narrow-beam underwater acoustic transducer in water when the diameter of the thin circular plate is 55 mm.

Fig. 21 is a directivity diagram of a low-frequency narrow-beam underwater acoustic transducer in water when the diameter of a thin circular plate is 55 mm.

Fig. 22 is a graph of the emission voltage response of the low-frequency narrow-beam underwater acoustic transducer in water when the diameter of the thin circular plate is 60 mm.

Fig. 23 is a directivity diagram of a low-frequency narrow-beam underwater acoustic transducer in water when the diameter of a thin circular plate is 60 mm.

In the figure: 1. a housing; 2. an acoustically transparent rubber; 3. a polyurethane foam; 4. a thin circular plate; 5. an upper end post; 6. piezoelectric ceramic plates; 7. a non-piezoelectric material; 8. a lower end post; 9. a bolt; 10. fastening a nut; 11. a positive electrode lead; 12. a negative electrode lead; 13. and sealing the rubber cover.

Detailed Description

The present invention will be described in further detail with reference to specific examples, but the embodiments of the present invention are not limited thereto.

As shown in fig. 1, a low-frequency narrow-beam underwater acoustic transducer comprises a housing 1 with an opening at the top, an acoustic transmission rubber 2 is tightly connected to the opening of the housing 1, a thin circular plate 4 is tightly bonded to the lower end surface of the acoustic transmission rubber 2, and a quasi-periodic structure transducer is fixedly connected to the lower end surface of the thin circular plate 4; the quasi-periodic structure transducer is connected with positive lead 11 and negative lead 12 one end, and the bottom of shell 1 is equipped with the trompil of drawing forth positive lead 11 and negative lead 12, and the other pot head of positive lead 11 and negative lead 12 is equipped with waterproof cable.

The quasi-periodic structure transducer includes: the piezoelectric ceramic plate type piezoelectric ceramic piezoelectric; the piezoelectric ceramic pieces 6 and the non-piezoelectric materials 7 are of a quasi-periodic structure, the polarization directions of the adjacent piezoelectric ceramic pieces 6 are opposite, one surface of each piezoelectric ceramic piece 6 is connected with an anode lead 11, and the other surface of each piezoelectric ceramic piece 6 is connected with a cathode lead 12; the bolt 9 is matched with the fastening nut 10 to fasten the piezoelectric ceramic piece 6 and the non-piezoelectric material piece 7 between the upper end column 5 and the lower end column 8.

The interior of the housing 1 is filled with polyurethane foam 3 for positioning and suspending the quasi-periodic structure transducer.

The below of the trompil of 1 bottom of shell is equipped with sealing rubber lid 13, and sealing rubber lid 13 fixed connection is in 1 bottom of shell, and sealing rubber lid 13 is equipped with the trompil that supplies waterproof cable to stretch out, forms seal structure between sealing rubber lid 13 and the shell 1, prevents the water infiltration.

The shell 1 is made of aluminum alloy, and the aluminum shell has good waterproof performance.

The upper end column 5 is made of aluminum and the lower end column 8 is made of steel.

The bolts 9 and the fastening nuts 10 are made of steel.

The thin circular plate 4 is made of aluminum, the thickness of the thin circular plate is 2mm, the aluminum material is light in weight, the acoustic impedance is small, the thin circular plate 4 and the upper end post 5 can be machined and molded into a whole, and the thin circular plate 4 with different diameters can be replaced and used conveniently.

The piezoelectric ceramic piece 6 and the non-piezoelectric material 7 are both circular rings, the outer diameter of the piezoelectric ceramic piece is the same as the diameter of the upper end column 5 and the lower end column 8, and the piezoelectric ceramic piece 6 is made of PZT-4 piezoelectric ceramic.

The principle of the invention for realizing the low-frequency narrow wave beam of the transducer is as follows: the quasi-periodic structure transducer does longitudinal vibration under the excitation of an external voltage signal and radiates acoustic energy outwards, and transducers with different resonant frequencies can be obtained by selecting different non-piezoelectric materials; the thin circular plate 4 is added at the radiation end of the quasi-periodic structure transducer, because the thickness of the thin circular plate 4 is far smaller than the diameter, the longitudinal vibration of the transducer is transmitted to the thin circular plate 4 to cause the thin circular plate 4 to generate bending vibration, and the transmission voltage response value and the beam width at the resonance frequency of the transducer are controlled by adjusting the diameter of the thin circular plate 4, so that the low-frequency narrow-beam small-size underwater acoustic transducer is realized.

Fig. 2, fig. 3, and fig. 4 are diagrams of the vibration mode, the transmission voltage response curve in water, and the directivity of the sandwich piezoelectric transducer, respectively.

Fig. 5, 6, 7 and 8 are respectively the mode shapes of the quasi-periodic structure transducer with the same size as the sandwich transducer and the non-piezoelectric material of aluminum, steel, polyimide or nylon. Comparing fig. 2 with fig. 5, 6, 7 and 8, it can be seen that by selecting different non-piezoelectric materials, transducers with different resonant frequencies can be obtained, and when the non-piezoelectric material is nylon, the resonant frequency of the quasi-periodic structure transducer is lower, which is 6700Hz lower than that of the sandwich transducer with the same size.

Fig. 9 and 10 are a response curve and a directivity diagram of a quasi-periodic transducer in water, which has the same size as the sandwich transducer and is made of nylon as a non-piezoelectric material. Comparing fig. 3 and 9, it can be seen that when the non-piezoelectric material is nylon, the response value of the transmission voltage at the resonant frequency of the quasi-periodic structure transducer is reduced by 18dB compared with the sandwich transducer. According to the definition of the beam width, as can be seen from fig. 4 and 10, the beam widths of-3 dB at the resonant frequency of the quasi-periodic structure transducer and the sandwich transducer, both of which are made of nylon, are 180 degrees.

Fig. 11, 12, and 13 are diagrams of the mode of the low-frequency narrow-beam underwater acoustic transducer, and a sound pressure diagram and a sound pressure level diagram in water, respectively, when the diameter of the thin circular plate 4 is 57 mm. The following non-piezoelectric materials of the low-frequency narrow-beam underwater acoustic transducer are all nylon. As can be seen from fig. 11, when the longitudinal vibration of the transducer is transmitted to the thin circular plate 4, the center portion of the thin circular plate 4 makes the longitudinal vibration and the edge portion makes the bending vibration.

Fig. 14, 16, 18, 20 and 22 are response curves of the emission voltage of the low-frequency narrow-beam underwater acoustic transducer in water when the diameter of the thin circular plate 4 is 57mm, 40mm, 50mm, 55mm and 60mm, respectively. Comparing the emission voltage response graphs, it can be seen that when the diameters of the thin circular plate 4 are different, the emission voltage response curves of the low-frequency narrow-beam underwater acoustic transducer are different, and when the diameter of the thin circular plate 4 is 57mm, the emission voltage response value at the resonant frequency of the low-frequency narrow-beam underwater acoustic transducer is the largest, which is increased by 9dB compared with the sandwich type transducer and increased by 27dB compared with the quasi-periodic structure transducer.

Fig. 15, 17, 19, 21, and 23 are directivity diagrams of the low-frequency narrow-beam underwater acoustic transducer in water when the diameter of the thin circular plate 4 is 57mm, 40mm, 50mm, 55mm, and 60mm, respectively. According to the definition of the beam width, as can be seen from the above directional diagram, when the diameter of the thin circular plate 4 is 57mm, the-3 dB beam width at the resonance frequency of the low-frequency narrow-beam underwater acoustic transducer is the smallest, and is about 52 degrees.

Therefore, it can be seen that when the non-piezoelectric material is nylon and the diameter of the thin circular plate 4 is 57mm, the transducer has a low resonant frequency, a maximum response value of the transmitting voltage and a narrowest beam width.

The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.