Small-size single crystal spliced circular ring transducer based on surface shear mode

Abstract

The invention relates to a small-size single crystal spliced circular ring transducer based on a surface shear mode, which comprises an upper sealing end cover, a lower sealing end cover and a spliced circular ring, the spliced circular ring, the upper sealing end cover and the lower sealing end cover are all circular ring-shaped, the upper sealing end cover is connected to the upper side of the spliced circular ring, the lower sealing end cover is connected to the lower side of the spliced circular ring, and the upper sealing end cover is connected to the lower side of the spliced circular ring. The upper sealing end cover, the splicing ring and the lower sealing end cover are coaxially arranged; the spliced ring comprises a plurality of piezoelectric single crystal wafers and a ring-shaped composite substrate, and the plurality of piezoelectric single crystal wafers surround in the circumferential direction to form a ring-shaped piezoelectric plate group; the piezoelectric plate group is embedded in the composite substrate; the piezoelectric single crystal wafer is made of a single crystal piezoelectric single crystal material polarized in a [011] c direction, and the cutting direction is a d36 direction with the highest piezoelectric coefficient; and the d36 direction of each piezoelectric single crystal wafer is consistent with the circumferential direction of the piezoelectric plate group. The size of the spliced circular ring transducer is reduced, the resonant frequency of the transducer is reduced, the emission voltage response of the transducer is improved, and the working bandwidth is expanded.

Description

Technical Field

[0001] The invention belongs to the field of underwater acoustics, and in particular relates to a small-size single crystal mosaic ring transducer based on surface shear mode. Background Art

[0002] Sound waves are the only carrier that can transmit information and energy over long distances in water. The main functions of sonar equipment are to detect, identify, locate, track and communicate underwater targets. As the main component of sonar equipment, the importance of transducers is self-evident. With the rapid development of sonar technology, the demand for transmitting transducers is concentrated in the directions of low frequency, small size and broadband.

[0003] In order to obtain greater sound radiation capability, the transmitting transducer generally operates at the fundamental frequency of the structural vibration mode. The resonant frequency of the underwater acoustic transducer is directly related to its size. The larger the structural size, the lower the resonant frequency. In addition, the radiated sound power of the low-frequency transducer is proportional to the frequency and the square of the radiation area. If the radiated sound power of the transducer is kept constant, the vibration velocity of the radiating surface must be greatly increased while the frequency is reduced to obtain sufficient volume velocity. However, due to the limitations of the power of the driving module and the mechanical strength of the transducer itself, it is often difficult to achieve low-frequency, high-response transmission by greatly increasing the vibration velocity of the radiating surface.

[0004] The mosaic ring transducer is a traditional low-frequency transmitting transducer. It solves the problem that large-sized piezoelectric round tubes cannot be sintered by splicing ceramic strips. When using radial vibration to radiate sound waves, the resonant frequency of the transducer is reduced inversely proportional to the transducer diameter. Therefore, it is difficult for a small-sized mosaic ring transducer to transmit low-frequency sound waves. Summary of the invention

[0005] In view of this, the present invention provides a small-sized single crystal mosaic ring transducer based on surface shear mode, which utilizes relaxor ferroelectric single crystal material to replace traditional piezoelectric ceramic material as the driving material of the transducer, and gives full play to the advantages of relaxor ferroelectric single crystal material in surface shear mode, such as high piezoelectric coefficient, high compliance coefficient and large electromechanical coupling coefficient, to reduce the size of the mosaic ring transducer, lower the resonant frequency of the transducer, improve the transmitting voltage response of the transducer, and expand the working bandwidth.

[0006] The technical solution adopted by the present invention is:

[0007] A small-size single crystal mosaic ring transducer based on surface shear mode comprises an upper sealing end cap, a lower sealing end cap and a mosaic ring, wherein the mosaic ring, the upper sealing end cap and the lower sealing end cap are all in a circular ring shape, the upper sealing end cap is connected to the upper side of the mosaic ring, the lower sealing end cap is connected to the lower side of the mosaic ring, and the upper sealing end cap, the mosaic ring and the lower sealing end cap are coaxially arranged;

[0008] The inlaid ring includes a plurality of piezoelectric single crystals and a circular composite substrate, wherein the plurality of piezoelectric single crystals surround a circular piezoelectric sheet group in the circumferential direction;

[0009] The piezoelectric sheet group is embedded in the composite substrate;

[0010] The piezoelectric single crystal adopts

[011] c Directionally polarized single crystal piezoelectric single crystal material, the cutting direction is d with the highest piezoelectric coefficient 36 direction;

[0011] Each of the piezoelectric unimorphs has a 36 The direction is consistent with the circumferential direction of the piezoelectric sheet group.

[0012] Preferably, the piezoelectric single crystal material is PMN-PT or PZN-PT.

[0013] Preferably, the piezoelectric single crystal is in the shape of a regular hexagon, wherein the relative directions of two opposite sides are d 36 direction.

[0014] Preferably, the number of the piezoelectric sheet groups is two, and the two piezoelectric sheet groups are arranged one above the other and interlocked with each other in the circumferential direction.

[0015] Preferably, a preset interval is left between the two piezoelectric sheet groups.

[0016] Preferably, it further comprises a backing layer, which is annular and arranged radially inwardly of the inlaid ring and fits with the inlaid ring.

[0017] Preferably, a watertight vulcanized layer is provided on the outer side of the inlaid ring, and a watertight vulcanized layer is provided on the inner side of the backing layer.

[0018] Preferably, the upper sealing end cover and the lower sealing end cover are connected by a pull rod and locked by a locking nut.

[0019] Preferably, the upper sealing end cover is also connected to a watertight connector, and the leads of each piezoelectric single crystal are led out through the watertight connector.

[0020] Beneficial effects of the present invention:

[0021] Compared with the existing inlaid rings whose functional materials are piezoelectric ceramics, the present invention selects piezoelectric single crystal materials as the driving material of the transducer, especially single crystals polarized in the

[011] c direction, which have an ultra-high piezoelectric coefficient (d36 can reach about 2500-2800pC / N), which is 6-8 times that of traditional piezoelectric ceramic materials, and is beneficial to improving the transmitting voltage response of the transducer; at the same time, its high compliance coefficient can reduce the resonant frequency of the transducer, which is beneficial to the miniaturization design of the transducer; the high electromechanical coupling coefficient is beneficial to the large bandwidth design of the transducer. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0023] Figure 1 It is a cross-sectional view of a single crystal mosaic ring transducer;

[0024] Figure 2 It is a perspective view of a single crystal mosaic ring transducer;

[0025] Figure 3 It is a schematic diagram of the structure of the inlaid ring;

[0026] Figure 4 It is a schematic diagram of the maximum displacement direction of single crystal vibration in the surface shear mode;

[0027] Figure 5 This is a schematic diagram of a single crystal in surface shear mode without the upper and lower corners.

[0028] In the figure: 1. piezoelectric single crystal; 2. upper sealing end cover; 3. lower sealing end cover; 4. watertight connector; 5. composite substrate; 6. backing layer; 7. watertight vulcanized layer; 8. insulating gasket; 9. pull rod; 10. locking nut; 11. corner transition piece. DETAILED DESCRIPTION

[0029] The present invention is described below based on embodiments, but the present invention is not limited to these embodiments. In the following detailed description of the present invention, some specific details are described in detail. In order to avoid confusing the essence of the present invention, known methods, processes, procedures, and components are not described in detail.

[0030] In addition, persons of ordinary skill in the art will appreciate that the drawings provided herein are for illustration purposes and are not necessarily drawn to scale.

[0031] Unless the context clearly requires otherwise, throughout the specification and claims, the words "include", "comprising" and similar words should be interpreted in an inclusive sense rather than an exclusive or exhaustive sense; that is, in the sense of "including but not limited to".

[0032] In the description of the present invention, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0033] See also Figure 1-Figure 5 The present invention provides a small-size single crystal mosaic ring transducer based on surface shear mode, comprising an upper sealing end cover 2, a lower sealing end cover 3 and a mosaic ring, wherein the mosaic ring, the upper sealing end cover 2 and the lower sealing end cover 3 are all in a circular ring shape, the upper sealing end cover 2 is connected to the upper side of the mosaic ring, the lower sealing end cover 3 is connected to the lower side of the mosaic ring, and the upper sealing end cover 2, the mosaic ring and the lower sealing end cover 3 are coaxially arranged;

[0034] The mosaic ring includes a plurality of piezoelectric single crystals 1 and a circular composite substrate 5. The plurality of piezoelectric single crystals 1 are circumferentially arranged to form a ring-shaped piezoelectric sheet group. Two adjacent piezoelectric single crystals can be spaced apart by a corner transition piece 11.

[0035] The piezoelectric sheet group is embedded in the composite substrate 5;

[0036] The piezoelectric single crystal 1 adopts

[011] c Directionally polarized single crystal piezoelectric single crystal material, the cutting direction is d with the highest piezoelectric coefficient 36 direction;

[0037] Each of the piezoelectric single crystal pieces 1 has a 36 The direction is consistent with the circumferential direction of the piezoelectric sheet group.

[0038] The piezoelectric single crystal piece 1 of the present invention is made of a piezoelectric single crystal material, and is specifically formed by performing surface shearing on the piezoelectric single crystal material. c The piezoelectric single crystal 1 is formed by polarization in the direction of the surface shearing, and then the piezoelectric single crystal 1 is formed by cutting, and the d of the piezoelectric single crystal 1 is made 36 The direction is consistent with the circumferential direction.

[0039] like Figure 4 As shown, the diagonal direction of the piezoelectric element 1 is d 36 direction, the vibration is mainly in d 36 The angular position of the direction results in a smaller contact area during transmission.

[0040] like Figure 5 As shown, the up and down direction is d 36 direction, can improve in d 36The device can expand or contract in the radial direction, so when it is applied to a piezoelectric sheet group, the radial size of the piezoelectric sheet group can be enlarged or reduced, thereby achieving the purpose of transmitting sound waves.

[0041] Preferably, the piezoelectric single crystal material is PMN-PT or PZN-PT.

[0042] Preferably, the piezoelectric single crystal 1 is in the shape of a regular hexagon, wherein the relative directions of two opposite sides are d 36 direction.

[0043] Preferably, the number of the piezoelectric sheet groups is two, and the two piezoelectric sheet groups are arranged one above the other and interlocked with each other in the circumferential direction.

[0044] Preferably, a preset interval (1 mm) is left between the two piezoelectric sheet groups.

[0045] Preferably, it further comprises a backing layer 6, which is annular and arranged radially inward of the inlaid ring and fits with the inlaid ring.

[0046] Preferably, a watertight vulcanized layer 7 is provided on the outer side of the inlaid ring, and a watertight vulcanized layer 7 is provided on the inner side of the backing layer 6 .

[0047] Preferably, the upper sealing end cover 2 and the lower sealing end cover 3 are connected by a tie rod 9 and locked by a locking nut 10 .

[0048] Preferably, the upper sealing end cover 2 is also connected to a watertight connector 4 , and the leads of each piezoelectric single crystal 1 are led out through the watertight connector 4 .

[0049] The present invention mainly consists of a piezoelectric single crystal 1, an upper sealing end cover 2, a lower sealing end cover 3, a watertight connector 4, a composite substrate 5, a lightweight backing layer 6, a watertight vulcanized layer 7, an insulating gasket 8, a pull rod 9, a locking nut 10, a corner transition piece and the like.

[0050] The functional material selected for the transducer of the present invention is

[011] c The single crystal of the plane shear mode vibration with polarization in the direction is made of PMN-PT, PZN-PT or a ferroelectric single crystal doped with other elements. The vibration direction is selected in the diagonal direction, and part of the cutting is performed in the vibration direction to ensure the bonding area. The size of the piezoelectric single crystal 1 is generally not more than 25×25mm, and the cutting length should not be too large, 4-5mm is sufficient.

[0051] The present invention adopts a method of combining the cut portion of the piezoelectric single crystal 1 and the corner transition piece when assembling the circular ring, which plays a role in improving the bonding strength and position control.

[0052] The inlaid annular electrodes of the present invention are led out from the upper and lower surfaces of the piezoelectric single crystal 1 and are finally welded on a watertight connector.

[0053] When the size of the piezoelectric single crystal piece 1 is too small, the height of the piezoelectric single crystal ring can be increased by splicing layers together as shown in FIG2 . The method is not limited to two layers, and can be more.

[0054] Combined with the tooling, the stacking and fixing of the mosaic rings are completed, and the composite base 5 is poured, such as Figure 3 As shown, it plays a role in improving the strength and power capacity of the inlaid ring.

[0055] Combination Figure 1 As shown, a lightweight backing layer 6 is bonded inside the poured composite inlaid circular ring to support the inlaid circular ring and reduce internal vortex flow.

[0056] Combination Figure 1 As shown, an upper sealing end cap 2, a lower sealing end cap 3, an insulating gasket 8, a pull rod 9, and a locking nut 10 are added to the upper and lower parts of the inlaid ring to fix the inlaid ring, which is placed in a mold and encapsulated with a watertight vulcanized layer 7 to complete the production of the entire inlaid ring transducer.

[0057] It should be understood that the above-mentioned embodiments are merely illustrative and not restrictive. Without departing from the basic principles of the present invention, various obvious or equivalent modifications or substitutions that can be made by those skilled in the art to the above-mentioned details will all be included in the scope of the claims of the present invention.

Claims

1. A small-size single crystal mosaic ring transducer based on surface shear mode, characterized in that: It comprises an upper sealing end cover, a lower sealing end cover and an inlaid ring, wherein the inlaid ring, the upper sealing end cover and the lower sealing end cover are all in an annular shape, the upper sealing end cover is connected to the upper side of the inlaid ring, the lower sealing end cover is connected to the lower side of the inlaid ring, and the upper sealing end cover, the inlaid ring and the lower sealing end cover are coaxially arranged; The inlaid ring includes a plurality of piezoelectric single crystals and a circular composite substrate, wherein the plurality of piezoelectric single crystals surround a circular piezoelectric sheet group in the circumferential direction; The piezoelectric sheet group is embedded in the composite substrate; The piezoelectric single crystal is made of a single crystal piezoelectric single crystal material polarized in the [011]c direction, and the cutting direction is d with the highest piezoelectric coefficient. 36 direction; Each of the piezoelectric unimorphs has a 36 The direction is consistent with the circumferential direction of the piezoelectric sheet group.

2. The small-sized single crystal mosaic ring transducer based on the surface shear mode according to claim 1 is characterized in that: The piezoelectric single crystal material is PMN-PT or PZN-PT.

3. The small-sized single crystal mosaic ring transducer based on the surface shear mode according to claim 2 is characterized in that: The piezoelectric single crystal is in the shape of a regular hexagon, wherein the relative directions of two opposite sides are d 36 direction.

4. The small-sized single crystal mosaic ring transducer based on the surface shear mode according to claim 3 is characterized in that: The number of the piezoelectric sheet groups is two, and the two piezoelectric sheet groups are arranged one above the other and interlocked with each other in the circumferential direction.

5. The small-sized single crystal mosaic ring transducer based on the surface shear mode according to claim 4 is characterized in that: A preset interval is left between the two piezoelectric sheet groups.

6. The small-sized single crystal mosaic ring transducer based on surface shear mode according to claim 5, characterized in that: It also includes a backing layer, which is annular and arranged on the radial inner side of the inlaid ring and fits with the inlaid ring.

7. The small-sized single crystal mosaic ring transducer based on the surface shear mode according to claim 6 is characterized in that: The outer side of the inlaid ring is provided with a watertight vulcanized layer, and the inner side of the backing layer is provided with a watertight vulcanized layer.

8. The small-sized single crystal mosaic ring transducer based on the surface shear mode according to claim 7 is characterized in that: The upper sealing end cover and the lower sealing end cover are also connected by a pull rod and locked by a locking nut.

9. The small-sized single crystal mosaic ring transducer based on the surface shear mode according to claim 8, characterized in that: The upper sealing end cover is also connected with a watertight connector, and the lead wires of each piezoelectric single crystal are led out through the watertight connector.

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