Ultrasonic transducer

Abstract

Disclosed in the present application is an ultrasonic transducer, comprising an acoustic wedge and a housing that encapsulates the acoustic wedge, wherein the acoustic wedge comprises a first surface and a second surface arranged opposite each other, the second surface being encapsulated inside the housing; piezoelectric ceramics are arranged on the second surface, which is inclined relative to the first surface; and backing is provided in an accommodating space between the second surface and the housing. In the acoustic wedge, a first sound absorption layer is provided on a connecting surface at the end of the second surface away from the first surface.

Description

Ultrasonic transducer TECHNICAL FIELD

[0001] The present application relates to the technical field of transducers, and in particular to an ultrasonic transducer. BACKGROUND

[0002] An ultrasonic transducer is a device capable of energy conversion, which is usually made of piezoelectric ceramic, i.e., the ultrasonic transducer can convert energy between electrical signals and mechanical vibrations by using the piezoelectric effect of piezoelectric ceramic; for example, when the ultrasonic transducer is used as a transmitter, its energy conversion mode is electrical energy-mechanical vibration-sound wave, and when the ultrasonic transducer is used as a receiver, its energy conversion mode is sound wave-mechanical vibration-electrical energy. SUMMARY

[0003] The present application provides an ultrasonic transducer, which is characterized in that a first sound-absorbing layer is arranged on the connecting surface of the sound wedge reflection area, so that the first sound-absorbing layer can at least absorb the sound waves emitted by the piezoelectric ceramic in the positive direction and reflected by the first surface, thereby preventing the sound waves from repeatedly reflecting inside the sound wedge.

[0004] The present application provides an ultrasonic transducer, which comprises:

[0005] a sound wedge comprising a first surface and a second surface arranged oppositely, wherein the second surface is arranged at a predetermined angle relative to the first surface; a piezoelectric ceramic arranged on the second surface; an outer shell for packaging the sound wedge, so as to package the second surface inside the outer shell; and a backing arranged in a containing space between the outer shell and the second surface; wherein, at one end of the second surface far away from the first surface, the sound wedge comprises a connecting surface for connecting the first surface and the second surface, and the connecting surface is provided with a first sound-absorbing layer, and the first sound-absorbing layer is at least used for absorbing sound waves emitted by the piezoelectric ceramic and reflected by the first surface.

[0006] In an embodiment, preferably, the connecting surface comprises a side wall portion arranged perpendicularly to the first surface and a planar portion arranged parallel to the first surface; and the first sound-absorbing layer extends along the planar portion and the side wall portion, respectively, from the edge line where the planar portion and the side wall portion meet.

[0007] In an embodiment, preferably, the first sound-absorbing layer has an extension length on the planar portion and the side wall portion, respectively, which at least covers the positions respectively reached by a beam of sound waves emitted by the piezoelectric ceramic at both ends thereof at a half-beam angle and reflected by the first surface.

[0008] In an embodiment, preferably, the connecting surface is provided with a first groove for bearing the first sound-absorbing layer.

[0009] In an embodiment, preferably, the first sound-absorbing layer has a thickness consistent with a half wavelength of a sound wave propagating therein.

[0010] In an embodiment, preferably, the first sound-absorbing layer is formed by epoxy resin bonding and curing of a first porous sound-absorbing material.

[0011] In an embodiment, preferably, the first porous sound-absorbing material comprises porous sound-absorbing softwood.

[0012] In an embodiment, preferably, the piezoelectric ceramic is provided with a second sound-absorbing layer on a side facing away from the second surface.

[0013] In an embodiment, preferably, the second sound-absorbing layer has a thickness consistent with a half wavelength of a sound wave propagating therein.

[0014] In an embodiment, preferably, the second sound-absorbing layer is formed by epoxy resin bonding and curing of a second porous sound-absorbing material.

[0015] In an embodiment, preferably, the second porous sound-absorbing material comprises porous sound-absorbing softwood.

[0016] In an embodiment, preferably, the second surface of the acoustic wedge is provided with a second groove, and the piezoelectric ceramic is arranged in the second groove.

[0017] In an embodiment, preferably, the backing is formed by curing of a mixture of epoxy resin and tungsten powder.

[0018] In an embodiment, preferably, the mass ratio of the epoxy resin to the tungsten powder is between 1:1 and 1:1.5.

[0019] In an embodiment, preferably, the housing is provided with a filling hole for filling the mixture for forming the backing after curing.

[0020] The one or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0021] The embodiments of the present application provide an ultrasonic transducer, which comprises an acoustic wedge and a housing encapsulating the acoustic wedge, the acoustic wedge comprising oppositely arranged first and second surfaces, wherein the second surface is encapsulated inside the housing, the second surface, which is arranged obliquely relative to the first surface, is provided with a piezoelectric ceramic, and a space between the second surface and the housing is provided with a backing; then, the embodiments of the present application are provided with a first sound-absorbing layer on a connecting surface of the second surface of the acoustic wedge, which is away from the first surface.

[0022] It can be understood that the sound waves emitted by the piezoelectric ceramic are emitted from the inside of the acoustic wedge to the first surface from the second surface, wherein part of the sound waves are emitted out through the first surface, and part of the sound waves are reflected back to the inside of the acoustic wedge by the first surface and reflected to the connecting surface connecting the second surface and the first surface, and then the first sound absorption layer arranged on the connecting surface can absorb the part of the sound waves reflected to the connecting surface, preventing repeated reflection in the acoustic wedge. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the description of the embodiments of the present application will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0024] Fig. 1 is a structural schematic diagram of the acoustic wedge in the embodiments of the present application.

[0025] Fig. 2 is a sectional structural schematic diagram of the ultrasonic transducer in the embodiments of the present application.

[0026] Fig. 3 is a structural schematic diagram of the piezoelectric ceramic emitting sound waves at a half-wave beam angle in the embodiments of the present application.

[0027] Fig. 4 is a structural schematic diagram of the ultrasonic transducer in the embodiments of the present application.

[0028] In the drawings, reference signs: 10-acoustic wedge, 11-first surface, 12-second surface, 13-connecting surface, 14-first groove, 15-second groove, 131-side wall part, 132-flat part, 20-piezoelectric ceramic, 30-outer shell, 31-filling hole, 40-backing, 50-first sound absorption layer, 60-second sound absorption layer, 70-cable, M-half-wave beam angle, X-first direction. DETAILED DESCRIPTION

[0029] In order to better understand the above technical solutions, the example embodiments of the present application will be described in detail below with reference to the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, not all embodiments of the present application, and it should be understood that the present application is not limited to the example embodiments described herein.

[0030] The ultrasonic transducer of the related art generally comprises an acoustic wedge, a shell encapsulating the acoustic wedge, and a backing filled between the acoustic wedge and the shell, the acoustic wedge comprising a first surface and a second surface oppositely arranged, wherein the second surface is obliquely arranged at a predetermined angle with the first surface, and the second surface is used for bonding a piezoelectric ceramic, so that the second surface can provide an incident angle for the acoustic waves emitted by the piezoelectric ceramic, which is between a first critical angle and a second critical angle.

[0031] When the piezoelectric ceramic is vibrating, the forward acoustic waves emitted by the piezoelectric ceramic will be partially emitted through the first surface and partially reflected back to the inside of the acoustic wedge when passing through the inside of the acoustic wedge to the first surface. The acoustic waves reflected back to the inside of the acoustic wedge will repeatedly reflect in the inside of the acoustic wedge, thereby adversely affecting the emission excitation of the piezoelectric ceramic.

[0032] In view of the above, the present application provides an ultrasonic transducer, which is capable of effectively absorbing the acoustic waves reflected back to the inside of the acoustic wedge through the first surface, preventing the acoustic waves from repeatedly reflecting in the inside of the acoustic wedge, thereby effectively eliminating the adverse effects on the emission excitation caused by the repeated reflection of the acoustic waves in the inside of the acoustic wedge.

[0033] FIG. 1 is a structural schematic diagram of an acoustic wedge, and FIG. 2 is a sectional structural schematic diagram of an ultrasonic transducer. Referring to FIGS. 1 and 2, an ultrasonic transducer comprises an acoustic wedge 10, a piezoelectric ceramic 20, a shell 30, a backing 40, and a first sound-absorbing layer 50. The acoustic wedge 10 comprises a first surface 11 and a second surface 12 oppositely arranged, and the second surface 12 is obliquely arranged at a predetermined angle with the first surface 11. The piezoelectric ceramic 20 is arranged on the second surface 12. The shell 30 is used for encapsulating the acoustic wedge 10 with the piezoelectric ceramic 20 arranged thereon (the acoustic wedge and the piezoelectric ceramic constitute an acoustic sensing part), so as to encapsulate the second surface 12 inside the shell 30. The backing 40 is arranged in a containing space between the shell 30 and the second surface 12.

[0034] In the embodiment, the acoustic wedge is made of polyether ether ketone (PEEK). The PEEK material has high temperature resistance, high wear resistance, and high acoustic transmission performance.

[0035] In an embodiment, the acoustic wedge is made of polyether ether ketone (PEEK). The PEEK material has high temperature resistance, high wear resistance, and high acoustic transmission performance.

[0036] In one embodiment, the acoustic wedge, for example, is in the shape of an irregular block, the acoustic wedge comprises a first surface, for example, the first surface is arranged perpendicularly to the first direction; wherein it can be understood that when the ultrasonic transducer is used as a transmitter, the first surface is the emitting surface of the emitted acoustic waves, and when the ultrasonic transducer is used as a receiver, the first surface is the receiving surface of the received acoustic waves.

[0037] In one embodiment, the acoustic wedge, for example, is in the shape of an irregular block, the acoustic wedge comprises a first surface, for example, the first surface is arranged perpendicularly to the first direction; wherein it can be understood that when the ultrasonic transducer is used as a transmitter, the first surface is the emitting surface of the emitted acoustic waves, and when the ultrasonic transducer is used as a receiver, the first surface is the receiving surface of the received acoustic waves.

[0038] The second surface is arranged at a predetermined angle with respect to the first surface, that is, referring to FIG. 1, at one end of the ultrasonic transducer (the left end in FIG. 1), the second surface is closer to the first surface, and then at the other end of the ultrasonic transducer (the right end in FIG. 1), the second surface is farther away from the first surface.

[0039] The second surface is arranged at a predetermined angle with respect to the first surface, that is, referring to FIG. 1, at one end of the ultrasonic transducer (the left end in FIG. 1), the second surface is closer to the first surface, and then at the other end of the ultrasonic transducer (the right end in FIG. 1), the second surface is farther away from the first surface.

[0040] The second surface is arranged at a predetermined angle with respect to the first surface, that is, referring to FIG. 1, at one end of the ultrasonic transducer (the left end in FIG. 1), the second surface is closer to the first surface, and then at the other end of the ultrasonic transducer (the right end in FIG. 1), the second surface is farther away from the first surface.

[0041] The second surface is arranged at a predetermined angle with respect to the first surface, that is, referring to FIG. 1, at one end of the ultrasonic transducer (the left end in FIG. 1), the second surface is closer to the first surface, and then at the other end of the ultrasonic transducer (the right end in FIG. 1), the second surface is farther away from the first surface.

[0042] Because the repeated reflection of the sound waves inside the acoustic wedge has an adverse effect on the sound waves emitted by the piezoelectric ceramic through the first surface, that is, has an adverse effect on the emission excitation of the piezoelectric ceramic, therefore, the embodiment can eliminate the above adverse effect by arranging the first sound-absorbing layer on the connecting surface.

[0043] It can be understood that the connecting surface is connected between the second surface and the first surface at one end of the acoustic wedge, and then the first sound-absorbing layer can be arranged on the area of the connecting surface that can be irradiated by the sound waves reflected through the first surface. In an embodiment, the connecting surface can generally be a right angle type as shown in FIG. 1 or FIG. 2, of course, the connecting surface can also be other shapes according to actual needs, and the embodiment does not limit this.

[0044] The embodiment of the present application provides an ultrasonic transducer, which comprises an acoustic wedge and a shell encapsulating the acoustic wedge, the acoustic wedge comprises a first surface and a second surface arranged oppositely, wherein the second surface is encapsulated inside the shell, the second surface arranged obliquely relative to the first surface is provided with a piezoelectric ceramic, and a containing space between the second surface and the shell is provided with a backing; then, the embodiment of the present application is provided with a first sound-absorbing layer on a connecting surface of the second surface of the acoustic wedge away from the first surface.

[0045] It can be understood that the sound waves emitted by the piezoelectric ceramic are emitted from the second surface to the first surface, wherein part of the sound waves is emitted through the first surface, and part of the sound waves is reflected back to the inside of the acoustic wedge and reflected to the connecting surface connecting the second surface and the first surface, and then the embodiment of the present application can absorb the part of the sound waves reflected to the connecting surface by arranging the first sound-absorbing layer on the connecting surface, to prevent repeated reflection of the sound waves inside the acoustic wedge, thereby solving the technical problem that part of the sound waves emitted by the piezoelectric ceramic is repeatedly reflected inside the acoustic wedge in the related art ultrasonic transducer, thereby adversely affecting the emission excitation thereof.

[0046] In a possible implementation manner, the connecting surface 13 comprises a side wall part 131 arranged perpendicularly to the first surface 11 and a plane part 132 arranged parallel to the first surface 11; wherein the first sound-absorbing layer 50 extends along the plane part 132 and the side wall part 131 respectively from the edge line where the plane part 132 and the side wall part 131 meet.

[0047] That is, in combination with the above description, the acoustic wedge is, for example, an irregular block, wherein at the end of the second surface of the acoustic wedge away from the first surface, the connecting surface can comprise two parts, one part is a side wall part perpendicular to the first surface, and the other part is a plane part arranged opposite and parallel to the first surface, and the plane part is connected with the second surface.

[0048] That is, the first sound absorbing layer can extend from the edge line where the planar portion meets the side wall portion along the planar portion and the side wall portion, respectively.

[0049] In one embodiment, the first sound absorbing layer 50 extends on the planar portion 132 and the side wall portion 131 at least to cover the positions reached by the sound waves respectively reflected by the first surface 11 from the sound waves emitted by the piezoelectric ceramic 20 at both ends in the extension direction of the second surface.

[0050] Firstly, it can be understood that when the piezoelectric ceramic emits sound waves, the ultrasonic ray energy is the largest along the extension line of the central axis (i.e. the normal line) of the piezoelectric ceramic (perpendicular to the surface of the piezoelectric ceramic), and the sound wave energy gradually weakens in other directions outwardly; and the angle between the extension line of the central axis of the piezoelectric ceramic and the position where the energy intensity is reduced by half (-3dB) outwardly is called the half beam angle.

[0051] Therefore, in the present embodiment, the extension lengths of the first sound absorbing layer on the planar portion and the side wall portion can be set as follows:

[0052] Referring to FIG. 3, along the extension direction of the second surface, the sound waves emitted by the piezoelectric ceramic at both ends in the extension direction of the second surface at the half beam angle will reach the planar portion and the side wall portion respectively after being reflected by the first surface, and then the extension lengths of the first sound absorbing layer on the planar portion and the side wall portion should at least cover the positions reached by the sound waves respectively after being reflected by the first surface.

[0053] For example, the sound waves emitted by one end of the piezoelectric ceramic in the extension direction of the second surface at the half beam angle will reach A of the planar portion after being reflected by the first surface, and then the extension length of the first sound absorbing layer from the edge line where the planar portion meets the side wall portion and along the planar portion should at least cover A; similarly, the sound waves emitted by the other end of the piezoelectric ceramic in the extension direction of the second surface at the half beam angle will reach B of the side wall portion after being reflected by the first surface, and then the extension length of the first sound absorbing layer from the edge line where the planar portion meets the side wall portion and along the side wall portion should at least cover B.

[0054] That is, on the connecting surface, the area covered by the first sound absorbing layer should at least include the reflection area of the sound waves emitted by the piezoelectric ceramic at the half beam angle.

[0055] In some embodiments, the coverage range of the first sound absorbing layer in the direction perpendicular to the X direction and the cable 70 (i.e. along the direction perpendicular to the paper surface) is the dimension of the transducer in the direction.

[0056] In one possible implementation, the connecting surface 13 is provided with a first recess 14 for carrying the first sound absorbing layer 50.

[0057] In this embodiment, it can be understood that the first groove can be arranged on the connecting surface of the acoustic wedge, and then the first sound-absorbing layer is arranged in the first groove.

[0058] Referring to FIGS. 1 and 2, considering that the shell directly abuts against the side wall portion of the acoustic wedge, the first groove should be arranged at least on the side wall portion of the acoustic wedge, and the depth of the first groove should be consistent with the thickness of the first sound-absorbing layer.

[0059] Of course, the planar portion mentioned above can be arranged with or without the groove since it does not directly abut against the shell.

[0060] In an embodiment, the thickness of the first sound-absorbing layer 50 is consistent with the half wavelength of the sound wave propagating therein, and the first sound-absorbing layer 50 is formed by bonding and curing the porous sound-absorbing material by using the epoxy resin.

[0061] In this embodiment, the thickness of the first sound-absorbing layer can be consistent with the half wavelength of the sound wave propagating therein, so it can be understood that in this way, the first sound-absorbing layer can effectively absorb the reflected sound wave inside the acoustic wedge, which is equivalent to improving the transmittance of the side wall portion of the acoustic wedge to the sound wave and avoiding the formation of interference waves of the sound wave reflected through the first surface inside the acoustic wedge.

[0062] In this embodiment, the first sound-absorbing layer can be formed by bonding and curing the porous sound-absorbing material by using the epoxy resin, and the porous sound-absorbing material can increase the attenuation of the sound wave vibration and easily absorb the sound wave.

[0063] In an embodiment, the porous sound-absorbing material, for example, includes porous sound-absorbing softwood, that is, the porous sound-absorbing softwood or wood residue is bonded and cured by using the epoxy resin to form the first sound-absorbing layer 50.

[0064] It can be understood that the first sound-absorbing layer prepared from the porous sound-absorbing softwood can not only absorb the reflected sound wave but also has a certain elasticity and can serve as a buffer layer between the shell and the acoustic wedge.

[0065] In a possible embodiment, the side of the piezoelectric ceramic 20 opposite to the second surface 12 is provided with a second sound-absorbing layer 60; the thickness of the second sound-absorbing layer 60 is consistent with the half wavelength of the sound wave propagating therein, and the second sound-absorbing layer 60 is formed by bonding and curing the porous sound-absorbing material by using the epoxy resin; and the porous sound-absorbing material includes porous sound-absorbing softwood.

[0066] First of all, it needs to be explained that in the ultrasonic transducer, the backing has two purposes, one of which is to absorb the sound wave emitted backward by the piezoelectric ceramic to reduce the inherent noise, and the other of which is to match the piezoelectric ceramic and absorb the excess vibration energy of the piezoelectric ceramic, so that the vibration of the piezoelectric ceramic decays as soon as possible after no signal is input, thereby improving the frequency bandwidth of the signal receiving probe.

[0067] However, in the related art ultrasonic transducer, only one layer of backing is provided, and the ability to absorb the back sound wave is limited, and the unabsorbed back sound wave will propagate through the backing to the acoustic wedge, which will adversely affect the emission excitation of the acoustic wedge.

[0068] Based on the above, the second sound absorbing layer is provided between the piezoelectric ceramic and the backing, referring to FIG. 2, wherein the second sound absorbing layer can be the same as the first sound absorbing layer described above, and is formed by porous sound absorbing softwood bonded and cured by epoxy resin.

[0069] Through the provision of the second sound absorbing layer, the second sound absorbing layer can effectively absorb the back sound wave emitted by the piezoelectric ceramic and prevent it from propagating through the backing to the acoustic wedge; in addition, as described above, the second sound absorbing layer has a certain elasticity, so that after the piezoelectric ceramic has no signal input, the vibration of the piezoelectric ceramic can also be accelerated to decay, that is, the tail effect on the piezoelectric ceramic is also well inhibited, thereby greatly increasing the echo signal, for example, the echo signal can be increased from 4.25V to 9.7V through measurement.

[0070] In combination with FIG. 1, a second groove 15 can be provided on the second surface 12 of the acoustic wedge 10, and then the piezoelectric ceramic 20 is arranged in the second groove 15.

[0071] Regarding the above-mentioned backing 40, in one possible implementation, the backing 40 is formed by mixing epoxy resin and tungsten powder and then curing.

[0072] In the embodiment, the backing can be formed by mixing tungsten powder and epoxy resin and then curing, and the mixed tungsten powder and epoxy resin form a high acoustic impedance material, so that the back sound wave of the piezoelectric ceramic will be scattered multiple times after encountering the tungsten powder particles in the backing, thereby consuming the energy of the sound wave and accelerating the decay of the sound wave.

[0073] In one implementation, the mass ratio of the epoxy resin to the tungsten powder can be between 1:1 and 1:1.5.

[0074] In one possible implementation, the shell 30 can be milled from stainless steel, and in combination with FIG. 4, the shell 30 is provided with a filling hole 31 for filling the mixture for forming the backing 40 after curing, and the cable 70 connected to the piezoelectric ceramic extends out of the shell.

[0075] The above describes the basic principles of the present application in combination with specific embodiments, but it needs to be pointed out that the advantages, benefits, effects and the like mentioned in the present application are only examples and are not limiting, and these advantages, benefits, effects and the like cannot be considered as necessary for each embodiment of the present application. In addition, the above specific details disclosed are only for the purpose of example and understanding, and are not limiting, and the above details do not limit the present application to be necessarily implemented with the above specific details.

[0076] The block diagrams of the devices, apparatuses, equipment, systems involved in the present application are only illustrative examples and are not intended to require or imply the connection, arrangement, configuration as shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, equipment, systems can be connected, arranged, configured in any manner. Words such as "include", "contain", "have" and the like are open-ended words, meaning "including but not limited to", and can be used interchangeably. The words "or" and "and" used herein mean the word "and / or", and can be used interchangeably unless the context clearly indicates otherwise. The word "such as" used herein means the phrase "such as but not limited to", and can be used interchangeably.

[0077] It also needs to be pointed out that in the devices, equipment and methods of the present application, each component or each step can be decomposed and / or recombined. These decompositions and / or recombination should be considered as equivalent solutions of the present application.

[0078] The above description of the disclosed aspects is provided so that any person skilled in the art can make or use the present application. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but is intended to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0079] The above description has been given for the purpose of illustration and description. Furthermore, this description is not intended to limit the embodiments of the present application to the forms disclosed. Although a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations of the aspects and embodiments discussed above are also within the scope of the present application.

Claims

1. An ultrasonic transducer, comprising: a sound wedge (10) comprising a first surface (11) and a second surface (12) oppositely arranged, the second surface (12) being arranged at a predetermined angle with respect to the first surface (11); a piezoelectric ceramic (20) arranged on the second surface (12); a housing (30) for encapsulating the sound wedge (10) so as to encapsulate the second surface (12) inside the housing (30); a backing (40) arranged in a space between the housing (30) and the second surface (12); wherein, at an end of the second surface (12) far from the first surface (11), the sound wedge (10) comprises a connecting surface (13) for connecting the first surface (11) and the second surface (12), the connecting surface (13) being provided with a first sound absorbing layer (50), the first sound absorbing layer (50) being arranged at least for absorbing sound waves emitted from the piezoelectric ceramic (20) and reflected by the first surface (11).

2. The ultrasonic transducer of claim 1, wherein, the connecting surface (13) comprises a side wall portion (131) arranged perpendicularly to the first surface (11) and a planar portion (132) arranged parallel to the first surface (11); wherein, the first sound absorbing layer (50) extends from an edge line of the planar portion (132) and the side wall portion (131) respectively along the planar portion (132) and the side wall portion (131).

3. The ultrasonic transducer of claim 2, wherein, the extension length of the first sound absorbing layer (50) on the planar portion (132) and the side wall portion (131) covers at least positions respectively reached by a sound wave emitted by the piezoelectric ceramic (20) at half beam angle (M) and reflected by the first surface (11).

4. The ultrasound transducer of any one of claims 1 to 3, wherein, the connecting surface (13) is provided with a first groove (14) for carrying the first sound absorbing layer (50).

5. The ultrasound transducer of any one of claims 1 to 4, wherein, the thickness of the first sound absorbing layer (50) is consistent with the half wavelength of sound waves propagating therein.

6. The ultrasound transducer of any one of claims 1 to 5, wherein, the first sound absorbing layer (50) is formed by bonding and curing a first porous sound absorbing material with epoxy resin.

7. The ultrasonic transducer of claim 6, wherein, the first porous sound absorbing material comprises porous sound absorbing softwood.

8. The ultrasound transducer of any one of claims 1 to 7, wherein, the piezoelectric ceramic (20) is provided with a second sound absorbing layer (60) on a side opposite to the second surface (12).

9. The ultrasonic transducer of claim 8, wherein, the thickness of the second sound absorbing layer (60) is consistent with the half wavelength of sound waves propagating therein.

10. The ultrasonic transducer of claim 9, wherein, the second sound absorbing layer (60) is formed by bonding and curing a second porous sound absorbing material with epoxy resin.

11. The ultrasonic transducer of claim 10, wherein, the second porous sound absorbing material comprises porous sound absorbing softwood.

12. The ultrasound transducer of any one of claims 1 to 11, wherein, the second surface (12) of the sound wedge (10) is provided with a second groove (15), and the piezoelectric ceramic (20) is arranged in the second groove (15).

13. The ultrasound transducer of any one of claims 1 to 12, wherein, the backing (40) is formed by curing a mixture of epoxy resin and tungsten powder.

14. The ultrasonic transducer of claim 13, wherein, the mass ratio of the epoxy resin to the tungsten powder is between 1:1 and 1:1.

5.

15. The ultrasound transducer of any one of claims 1 to 14, wherein, the housing is provided with a filling hole for filling the mixture for forming the backing after curing.

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