CN108769869A - A kind of deep water bending disk energy converter - Google Patents

Abstract

The invention provides a deep-water curved disk transducer, which belongs to the technical field of underwater acoustic emission transducers. The transducer includes an outer casing; a piezoelectric ceramic disc; a radiation head; an anti-acoustic baffle; an inner casing and other structural parts. The curved disk transducer of the present invention is a deep water curved disk transducer designed by utilizing the overflow structure to balance the internal and external pressure. When the transducer is working, the piezoelectric ceramic and the metal plate are used to bend and vibrate together. At the same time, due to the effect of the anti-acoustic baffle, the medium in the inner cavity vibrates in phase with the medium outside the metal plate, and radiates energy into the water. The characteristics of the underwater acoustic transducer are that it can work in deep water, has high low-frequency transmission voltage response, light weight, and is simple to manufacture, and can be used in fields such as hanging sonar and underwater acoustic countermeasures.

Description

A deep water curved disk transducer

technical field

The invention relates to an underwater acoustic transmitter, in particular to a deep-water curved disk transducer, which can be used in the fields of hoisting sonar, sonobuoys, underwater acoustic countermeasures and the like.

Background technique

Sonar systems play an important role in the exploration and development of deep-sea seabed mineral resources, marine biology research, and deep-sea security, and the design of deep-sea transducers as the eyes and ears of sonar is one of the key technologies.

The first thing to consider for equipment working in a deep sea environment is that the equipment can withstand high hydrostatic pressure and perform well. Therefore, in the design of underwater acoustic transducers working in deep sea environments, in addition to using materials with high compressive strength, the internal and external pressure balance compensation overflow structure is mainly used to solve the problem of pressure release, and at the same time, the resonance of the liquid cavity is also used to reduce the pressure. The frequency band of the transducer can be widened.

Low-frequency sound waves mainly refer to sound waves with a frequency below 3kHz, which have very important application values in marine research, resource development, military and other fields. Therefore, it is particularly important to develop low-frequency underwater acoustic transducers. There are many ways to achieve low-frequency radiation of underwater acoustic transducers, such as bending vibration transducers, flexural transducers, and Helmholtz resonators.

Low-frequency transducers using Helmholtz resonator structures are typical ultra-low-frequency transducers driven by a series of single piezoelectric disks and double piezoelectric disks developed by Ralph S. Woollet et al. in 1976. The fluid in the Helmholtz cavity is excited by the bending vibration of the piezoelectric bending disc to radiate ultra-low frequency sound waves outward. The maximum sound source level of the 40Hz single piezoelectric disk Helmholtz ultra-low frequency transducer is 196dB, the mass is 2800kg, and the maximum working depth is 460m. The maximum sound source level of the 65Hz single piezoelectric disk Helmholtz ultra-low frequency transducer is 203dB, and the mass is 1900kg.

The representative bending vibration transducer is the HX-554 bending vibration ultra-low frequency underwater acoustic transducer used in the Pacific Acoustic Temperature Measurement Program. The transducer mainly uses ten curved strips to form a cylindrical shape, and the ultra-low frequency emission of the transducer is realized through the bending vibration of the three stacks. The transducer has a diameter of 0.94m, weighs 2300kg in air and 700kg in water, has a resonance frequency of 75Hz, a maximum sound power of 420W, and a bandwidth of 37.5Hz.

The most common type of bending vibration transducer is the bending disc transducer, which can be divided into a double stack structure consisting of two piezoelectric ceramic discs bonded together and a metal disc in the middle. The upper and lower piezoelectric ceramic discs are bonded together with a three-stack structure. This transducer has the characteristics of low frequency, high power, small size, simple structure, and easy production. It is also easy to match with water and air. It can be used as a low-frequency sound source in various detection equipment such as buoy sonar and pendant sonar, and can also be arranged in an array in a certain form. However, due to the weak ability of its vibrator to resist one-sided pressure, it cannot be used in too deep waters.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of existing curved underwater acoustic transducers, solve the problem of weak single-sided pressure resistance of curved underwater acoustic transducers, and provide a small size, light weight, and can be used in deep water conditions. The working deep water curved disk transducer, on the basis of maintaining the low-frequency emission characteristics of the curved transducer with a small volume, improves the emission response, reliability and resistance to static water of the flooded curved disk transducer pressure capacity etc.

The object of the present invention is achieved in this way: comprising an outer casing, a circular metal plate arranged on the upper end of the outer casing, a piezoelectric ceramic wafer arranged on the end surface of the circular metal plate, and an inner casing arranged on the lower end of the circular metal plate . The anti-sound baffle provided at the lower end of the inner shell, the upper end surface of the outer shell is evenly provided with quasi-elliptical long holes, the circumference of the inner shell is evenly provided with square long holes, the inner surface of the outer shell and the anti-acoustic baffle The outer cavity is formed between the baffle and the inner shell, and the outer cavity communicates with the external environment liquid through the elliptical long hole, and the inner cavity and the outer cavity formed between the anti-sound baffle and the metal plate are realized through the square long hole. Liquid circulation.

The present invention also includes such structural features:

1. An annular rib is also provided in the middle of the annular baffle.

2. The radius of the circular metal plate is smaller than the inner diameter of the outer casing.

Compared with the prior art, the beneficial effect of the present invention is: the present invention is a curved disk type underwater acoustic emission transducer which adopts piezoelectric ceramic disc and circular metal plate to realize bending vibration. The underwater acoustic transducer can work in deep water, has the characteristics of low frequency, high transmission voltage response, simple structure, light weight, etc., and can be used in fields such as hanging sonar, sonobuoys, and underwater acoustic countermeasures.

In the present invention, one end face of the outer shell connected to the metal plate is distributed with oval-shaped long holes in the upper direction, and the square long holes are distributed axially symmetrically on the surface of the inner shell, so that the inner surface of the outer shell, the anti-sound baffle, and the outer surface of the inner shell The outer cavity is formed, the inner cavity formed between the anti-acoustic baffle and the metal plate, and the liquid communication between the two maintains the pressure balance between the inside of the transducer and the outside world, and improves the compressive strength of the transducer. The working depth of the transducer is increased; when the transducer is working, due to the effect of the anti-acoustic baffle, the medium excited by the radiation surface composed of the piezoelectric ceramic disc and the metal plate vibrates in the same phase as the medium in the inner cavity of the transducer. The acoustic radiation capability and radiated acoustic power of the transducer are increased, thereby increasing its working distance. Compared with the traditional curved disc transducer, in addition to the advantages of small size, high power, low frequency, etc., this transducer structure design also enhances the compressive capacity of the core components of the transducer, further improving its working depth And working distance, it can be applied to technical fields such as deep water acoustic detection, measurement, and marine resource exploration and development.

Description of drawings

Fig. 1 is the schematic diagram of deep water curved disc transducer of the present invention;

Fig. 2 is a schematic cross-sectional view of a deep water curved disk transducer of the present invention;

Fig. 3 is a schematic diagram of the inner shell structure of the deep water curved disk transducer;

Fig. 4 is a schematic diagram of the deep water curved disc transducer after potting;

Fig. 5 is a schematic cross-sectional view of the deep water curved disc transducer after potting;

Reference signs: 1-piezoelectric ceramic disc, 2-circular metal plate, 3-inner shell, 4-anti-acoustic baffle, 5-outer shell, 6-type oval long hole, 7-square long hole, 8-ring rib, 9-polyurethane.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

As shown in Fig. 1 to Fig. 2, the deep water curved disc transducer of the present invention mainly includes piezoelectric ceramic disc 1, circular metal plate 2, inner shell 3, anti-acoustic baffle 4 and other structures. The outer shell and the inner shell adopt a cylindrical shell; the circular metal plate is located at one end of the outer shell, and the radius of the metal plate is smaller than the inner diameter of the outer shell; the piezoelectric ceramic disc is located outside the metal plate; the inner shell and the metal The inside of the board is connected; the anti-acoustic baffle is connected with the inner casing.

As shown in Figure 1, the inner casing of the present invention adopts an annular metal structure, and square slotted holes are distributed axially symmetrically on the annular surface of the inner casing. It is connected with the circular metal plate, and the periphery of the circular metal plate is distributed with oval-shaped long holes in the circumferential direction.

As shown in Figures 2 to 3, an outer cavity is formed between the inner surface of the outer shell of the present invention, the anti-acoustic baffle, and the outer surface of the inner housing, and an inner cavity is formed between the anti-acoustic baffle and the metal plate, and the outer cavity passes through The quasi-elliptical elongated hole structure 6 is in liquid communication with the external environment, and the inner cavity and the outer cavity are in liquid communication through the square elongated hole 7 structure.

The circular metal plate is made of duralumin, the outer side of the metal plate is frosted, and the inner side of the metal plate has a ring groove. Or bonding.

The piezoelectric ceramic disc is bonded to the outside of the circular metal plate, and is processed by PZT-4 piezoelectric ceramics polarized in the thickness direction. The surface of the disc is plated with silver electrodes, so it has a good reverse piezoelectric effect.

The anti-sound baffle is a circular metal structure lined with air. The upper surface of the anti-sound baffle is connected to the inner cavity, the lower surface of the anti-sound baffle is connected to the outer cavity, and there is a ring rib in the cavity of the anti-sound baffle. In structure 8, the annular rib structure is concentric and coaxial with the anti-sound baffle, thereby increasing the rigidity of the anti-sound baffle.

As shown in Figures 4 to 5, a layer of circular polyurethane rubber is covered on the radiating surface formed by the piezoelectric ceramic disc and the circular metal plate, so that the piezoelectric ceramic is insulated from the external environment.

The basic steps of making the mosaic curved disc underwater acoustic transducer are as follows:

1. Connect the two wires to the upper surface of the piezoelectric ceramic disc 1 and the upper surface of the circular metal plate respectively by welding, and bond the piezoelectric ceramic disc 1 to the upper surface of the circular metal plate 2 with epoxy resin surface, to ensure that the two are concentric and coaxial.

2. The lower surface of the circular metal plate 2 is bonded to one end of the inner casing 3, and the upper surface of the anti-sound baffle 4 is bonded to the other end of the inner casing 3 to ensure that the circular metal plate 2, the inner casing 3 and the The anti-acoustic baffles 4 are concentric and coaxial.

3. Bond the annular surface of the circular metal plate 2 to the end of the outer casing 5 with the elliptical long hole 6 to ensure that the end surface of the outer casing 5 and the upper surface of the circular metal plate 2 are located in the same horizontal plane.

After the transducer of the present invention enters the water, since the internal and external cavities of the transducer are in liquid communication with the internal cavity, the pressure of the radiation surface formed by the piezoelectric ceramic disc and the outer side of the metal plate is balanced with the internal cavity. When the transducer works in water, an alternating electric field is applied to the piezoelectric ceramic disc 1 . Under the excitation of the alternating electric field, it produces plane expansion vibration. Because it is connected with the metal plate, the edge of the metal plate is simply supported, and then the piezoelectric ceramics and the metal plate are excited to bend and vibrate together, radiating energy to the water. At the same time, the lower surface of the metal plate is connected to the inner liquid chamber, and the medium in the inner liquid chamber is excited by it to vibrate. Due to the anti-phase effect of the anti-acoustic baffle, the vibration phase of the inner liquid chamber medium and the outer medium of the metal plate is the same, thereby enhancing the exchange rate. The sound radiation ability of the energy device improves its emission sound power.

Working principle of the present invention:

The curved disc transducer of the present invention is a deep water curved disc transducer designed on the principle of using an overflow structure to balance internal and external pressures. When the transducer enters the water, since the inner and outer chambers of the transducer are in liquid communication with the inner chamber, the pressure of the radiation surface formed by the piezoelectric ceramic disc and the outer side of the metal plate is balanced with the pressure of the inner chamber. When the transducer is working, an AC voltage load is applied to the piezoelectric ceramic disc, causing it to generate plane expansion vibration. Since it is connected to the metal plate, the edge of the metal plate is simply supported, and then the piezoelectric ceramic and the metal plate are jointly bent. Vibrates, radiating energy into the water. At the same time, the lower surface of the metal plate is connected to the inner liquid chamber, and the medium in the inner liquid chamber is excited by it to vibrate. Due to the anti-phase effect of the anti-acoustic baffle, the vibration phase of the inner liquid chamber medium and the outer medium of the metal plate is the same, thereby enhancing the exchange rate. The sound radiation ability of the energy device improves its emission sound power.

The invention includes an outer shell, a piezoelectric ceramic disc, a circular metal plate, an inner shell and an anti-acoustic baffle; the outer shell and the inner shell adopt a cylindrical shell; the feature is that the circular metal plate Located at one end of the outer shell, the radius of the metal plate is smaller than the inner diameter of the outer shell; the piezoelectric ceramic disc is located outside the metal plate; the inner shell is connected to the inner side of the metal plate; the anti-sound baffle is connected to the inner shell. The outer casing is connected with the metal plate and has oval-shaped long holes distributed in the circumferential direction on the end face. An outer cavity is formed between the inner surface of the outer shell, the anti-acoustic baffle, and the inner shell, and the outer cavity can communicate with the external environment through the long hole structure. The outer side of the metal plate is smooth, the inner side of the metal plate has an annular groove, and the thickness of the edge of the metal plate is greater than that of the center of the metal plate. The piezoelectric ceramic disc is located outside the metal plate, and the piezoelectric ceramic disc is concentric and coaxial with the metal plate. The radiation surface formed by the piezoelectric ceramics and the circular metal plate can radiate energy into the water. The inner shell is connected with the circular metal plate, and the surface of the inner shell between the metal plate and the anti-sound baffle is axially symmetrically distributed with square slotted holes. The anti-sound baffle is connected with the inner casing, and the inner cavity and the outer cavity formed between the anti-sound baffle and the metal plate can communicate with liquid through the rectangular long holes. The anti-sound baffle is a circular metal structure lined with air, the upper surface of the anti-sound baffle is connected with the inner cavity, and the lower surface of the anti-sound baffle is connected with the outer cavity. There is an annular rib structure in the cavity of the anti-sound baffle, and the annular rib structure is concentric and coaxial with the anti-sound baffle.

To sum up, the present invention discloses a curved disk-type underwater acoustic transducer that can be used to emit sound waves in deep water, and belongs to the technical field of underwater acoustic emission transducers. The transducer includes an outer casing; a piezoelectric ceramic disc; a radiation head; an anti-acoustic baffle; an inner casing and other structural parts. The curved disk transducer of the present invention is a deep water curved disk transducer designed by utilizing the principle of overflow structure to balance internal and external pressure. When the transducer is working, it uses piezoelectric ceramics and metal plates to bend and vibrate together. At the same time, due to the effect of the anti-acoustic baffle, the medium in the inner cavity vibrates in phase with the medium outside the metal plate, and radiates energy into the water. The underwater acoustic transducer is characterized by being able to work in deep water, high response to low-frequency transmission voltage, light in weight, and simple to manufacture, and can be used in fields such as hanging sonar and underwater acoustic countermeasures.

Claims (3)

1. a kind of deep water is bent disk energy converter, it is characterised in that：Including outer housing, circular metal in outer housing upper end is set Plate, be arranged circular metal plate upper surface piezoelectric ceramic wafer, be arranged including the inner housing of circular metal plate lower end, setting The Antisoundbaffle of shell lower end, the outer housing upper surface are evenly arranged with class ellipse slot hole, on the inner housing periphery It is even to be provided with rectangular slot hole, outer chamber is formed between the outer housing inner surface and Antisoundbaffle, Inner shells, outer chamber passes through class Oval slot hole and external environment liquid communication, the inner chamber body formed between Antisoundbaffle and metallic plate pass through rectangular length with outer chamber Realize liquid communication in hole.

2. a kind of deep water according to claim 1 is bent disk energy converter, it is characterised in that：Among the annular baffle also It is provided with circumferential rib.

3. a kind of deep water according to claim 1 or 2 is bent disk energy converter, it is characterised in that：The circular metal plate Radius be less than outer housing internal diameter.