Ultrasonic transducer

Abstract

The ultrasonic transducer comprises an acoustic wedge and a shell for packaging the acoustic wedge, the acoustic wedge comprises a first surface and a second surface which are oppositely arranged, the second surface is packaged in the shell, piezoelectric ceramics are distributed on the second surface which is obliquely arranged relative to the first surface, and the piezoelectric ceramics are arranged on the first surface and the second surface. A back lining is arranged in an accommodating space between the second surface and the shell; then, a first sound absorption layer is arranged on the connection surface of one end, far away from the first surface, of the second surface of the sound wedge; it can be understood that the first sound absorption layer can absorb sound waves reflected to the connecting surface, the sound waves are prevented from being repeatedly reflected in the sound wedge, and the technical problem that in an existing ultrasonic transducer, part of sound waves emitted by piezoelectric ceramics are repeatedly reflected in the sound wedge, so that adverse effects are caused to emission excitation of the ultrasonic transducer is solved.

Description

Technical Field

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

[0002] An ultrasonic transducer is a device capable of energy conversion, which is usually made of piezoelectric ceramics. That is, an ultrasonic transducer can use the piezoelectric effect of piezoelectric ceramics to convert energy between electrical signals and mechanical vibrations; 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.

[0003] In a related scheme, an ultrasonic transducer generally includes an acoustic wedge and a shell encapsulating the acoustic wedge, the acoustic wedge includes a second surface and a first surface set at an angle, piezoelectric ceramics are pasted on the second surface of the acoustic wedge, and then the space between the second surface of the acoustic wedge and the shell is filled with a backing.

[0004] However, it is found that in the ultrasonic transducer of the above structure, when the piezoelectric ceramic vibrates, the forward sound wave emitted by it will exist inside the sound wedge and reflect repeatedly after being reflected by the first surface of the sound wedge, thereby adversely affecting the emission excitation. Summary of the invention

[0005] In response to at least one aspect of the above technical problems, an embodiment of the present application provides an ultrasonic transducer, which arranges a first sound absorbing layer on the connecting surface of the sound wedge reflection zone, so that the first sound absorbing layer can at least absorb the sound waves forwardly emitted by the piezoelectric ceramic and reflected by the first surface, thereby preventing the sound waves from being repeatedly reflected inside the sound wedge, thereby solving the technical problem in the existing ultrasonic transducer that part of the sound waves emitted by the piezoelectric ceramic are repeatedly reflected inside the sound wedge, thereby adversely affecting its emission excitation.

[0006] The present application provides an ultrasonic transducer, the ultrasonic transducer comprising:

[0007] An acoustic wedge, comprising a first surface and a second surface arranged opposite to each other, wherein the second surface is inclined at a predetermined angle relative to the first surface;

[0008] Piezoelectric ceramics, arranged on the second surface;

[0009] A housing for encapsulating the acoustic wedge so that the second surface is encapsulated inside the housing;

[0010] A backing disposed in a receiving space between the housing and the second surface;

[0011] Wherein, at the end of the second surface which is farther from the first surface, the acoustic wedge includes 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 to absorb sound waves emitted from the piezoelectric ceramic and reflected by the first surface.

[0012] In one embodiment, preferably, the connecting surface includes a side wall portion disposed perpendicularly to the first surface, and a plane portion disposed parallel to the first surface;

[0013] The first sound absorbing layer extends from a ridge line where the plane portion and the side wall portion meet along the plane portion and the side wall portion respectively.

[0014] In one embodiment, preferably, the extension lengths of the first sound absorbing layer on the planar portion and the side wall portion at least cover the positions reached by a pair of sound waves emitted by the piezoelectric ceramic at a beam angle after being reflected by the first surface.

[0015] In one embodiment, preferably, the connection surface is provided with a first groove, and the first groove is used to support the first sound absorbing layer.

[0016] In one embodiment, preferably, the thickness of the first sound absorbing layer is consistent with the half wavelength of the sound wave when propagating therein, and the first sound absorbing layer is formed by bonding and curing porous sound absorbing materials with epoxy resin.

[0017] In one embodiment, preferably, the porous sound-absorbing material comprises porous sound-absorbing cork.

[0018] In one embodiment, preferably, a second sound absorbing layer is provided on a side of the piezoelectric ceramic facing away from the second surface.

[0019] In one embodiment, preferably, the thickness of the second sound absorbing layer is consistent with the half wavelength of the sound wave when propagating therein, and the second sound absorbing layer is formed by bonding and curing porous sound absorbing materials with epoxy resin.

[0020] In one embodiment, preferably, the porous sound-absorbing material comprises porous sound-absorbing cork.

[0021] In one embodiment, preferably, the backing is formed by mixing epoxy resin and tungsten powder and then curing.

[0022] In one embodiment, preferably, the mass ratio of the epoxy resin to the tungsten powder is between 1:1 and 1:1.5.

[0023] In one embodiment, preferably, the shell is provided with a filling hole, and the filling hole is used to fill the mixture of the backing before curing.

[0024] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0025] An embodiment of the present application provides an ultrasonic transducer, which includes an acoustic wedge and a shell that encapsulates the acoustic wedge, the acoustic wedge includes a first surface and a second surface that are oppositely arranged, wherein the second surface is encapsulated inside the shell, the second surface that is inclined relative to the first surface is provided with piezoelectric ceramics, and a backing is provided in the accommodating space between the second surface and the shell; then, the embodiment of the present application provides a first sound absorbing layer on the connecting surface of the second surface of the acoustic wedge at the end farther from the first surface.

[0026] It can be understood that the sound waves emitted by the piezoelectric ceramic will be emitted from the second surface from the inside of the sound wedge to the first surface, wherein part of the sound waves will be emitted through the first surface, and part of the sound waves will be reflected by the first surface back to the inside of the sound wedge and reflected to the connecting surface connecting the second surface and the first surface. Then, in this embodiment, a first sound absorbing layer is provided on the connecting surface, and the first sound absorbing layer can absorb the part of the sound waves reflected to the connecting surface to prevent it from being repeatedly reflected inside the sound wedge, thereby solving the technical problem in the existing ultrasonic transducer that part of the sound waves emitted by the piezoelectric ceramic are repeatedly reflected inside the sound wedge, thereby causing an adverse effect on its emission excitation. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0028] Figure 1 Schematic diagram of the structure of the acoustic wedge described in the embodiment of the present application.

[0029] Figure 2 Schematic diagram of the cross-sectional structure of the ultrasonic transducer described in the embodiment of the present application.

[0030] Figure 3 It is a schematic diagram of the structure of the piezoelectric ceramic emitting sound waves at a beam angle in an embodiment of the present application.

[0031] Figure 4 Schematic diagram of the structure of the ultrasonic transducer described in the embodiment of the present application.

[0032] Wherein, the reference numerals are:

[0033] 10-sound wedge, 11-first surface, 12-second surface, 13-connecting surface, 14-first groove, 15-second groove,

[0034] 131- side wall portion, 132- plane portion,

[0035] 20- piezoelectric ceramics,

[0036] 30-housing, 31-filling hole,

[0037] 40- backing,

[0038] 50- first sound absorbing layer,

[0039] 60- second sound absorbing layer,

[0040] 70-cable,

[0041] M - beam angle,

[0042] X - first direction. DETAILED DESCRIPTION

[0043] In order to better understand the above technical solution, the example embodiments of the present application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. It should be understood that the present application is not limited to the exemplary embodiments described here.

[0044] An existing ultrasonic transducer generally includes an acoustic wedge, a shell that encapsulates the acoustic wedge, and a backing filled between the acoustic wedge and the shell. The acoustic wedge includes a first surface and a second surface that are arranged opposite to each other, wherein the second surface is inclined at a predetermined angle to the first surface, and the second surface is used to bond piezoelectric ceramics, so that the second surface can provide an incident angle for the sound waves emitted by the piezoelectric ceramics, so that it is between the first critical angle and the second critical angle.

[0045] When the piezoelectric ceramic is vibrating, the forward sound waves it emits will pass through the first surface when emitted from the inside of the sound wedge, and part of them will be emitted through the first surface, and part of them will be reflected back to the inside of the sound wedge through the first surface. The sound waves reflected back to the inside of the sound wedge will be repeatedly reflected inside the sound wedge, thereby adversely affecting the emission excitation of the piezoelectric ceramic.

[0046] In view of the above situation, the present application provides an ultrasonic transducer, which, by setting a first sound-absorbing layer in the reflection area of ​​the sound wedge, can effectively absorb the sound waves reflected back to the inside of the sound wedge through the first surface, prevent them from being repeatedly reflected inside the sound wedge, and thus effectively eliminate the adverse effects on the emission excitation caused by the repeated reflection of part of the sound waves inside the sound wedge.

[0047] Figure 1 is a schematic diagram of the structure of the sound wedge. Figure 2 For a cross-sectional view of the ultrasonic transducer, please refer to Figure 1 , Figure 2An ultrasonic transducer includes 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 includes a first surface 11 and a second surface 12 arranged opposite to each other, and the second surface 12 is inclined at a predetermined angle relative to the first surface 11; the piezoelectric ceramic 20 is arranged on the second surface 12; the shell 30 is used to encapsulate the acoustic wedge 10 arranged with the piezoelectric ceramic 20 (the acoustic wedge and the piezoelectric ceramic constitute the acoustic sensing part) so as to encapsulate the second surface 12 inside the shell 30; the backing 40 is arranged in the accommodating space between the shell 30 and the second surface 12.

[0048] Among them, at the end of the second surface 12 which is farther away from the first surface 11, the acoustic wedge 10 includes a connecting surface 13 for connecting the first surface 11 and the second surface 12. The connecting surface 13 is provided with a first sound absorbing layer 50. The first sound absorbing layer 50 is at least used to absorb the sound waves emitted from the piezoelectric ceramic 20 and reflected by the first surface 11.

[0049] Specifically, the acoustic wedge is, for example, in an irregular block shape, and includes a first surface, which is, for example, arranged perpendicular to the first direction; wherein it can be understood that when the ultrasonic transducer is used as a transmitter, the first surface is the transmitting surface for transmitting sound waves, and when the ultrasonic transducer is used as a receiver, the first surface is the receiving surface for receiving sound waves.

[0050] The acoustic wedge further comprises a second surface arranged opposite to the first surface, and the second surface is inclined at a predetermined angle to the first surface. Figure 1 , at one end of the ultrasonic transducer ( Figure 1 The second surface is closer than the first surface, and then, at the other end of the ultrasonic transducer ( Figure 1 The second surface is farther away from the first surface than the right end in FIG.

[0051] The second surface is provided with piezoelectric ceramics, which are for example bonded to the second surface. Figure 1 At this time, the second surface is tilted relative to the first surface, which can provide an incident angle for the sound waves emitted by the piezoelectric ceramic to the first surface. It can be understood that the incident angle is related to the above-mentioned predetermined angle. For example, the incident angle provided can make the sound waves passing through the first surface be emitted along the first direction X (that is, perpendicular to the first surface). Of course, it can also be emitted at other angles relative to the first surface. In other words, the purpose of the second surface being tilted at a predetermined angle relative to the first surface is to make the sound waves passing through the first surface be emitted at a certain angle.

[0052] The shell encapsulates the acoustic wedge along the first direction X and encapsulates the second surface inside the shell. Then, the mixture before the backing is cured is filled into the shell. When the mixture is cured, the backing is formed. That is, the backing is arranged in the accommodating space between the shell and the second surface.

[0053] Among them, being able to understand, combining Figure 2 After the sound waves emitted by the piezoelectric ceramic are emitted from the inside of the sound wedge to the first surface through the second surface, part of the sound waves will pass through the first surface and be emitted at a certain angle relative to the first surface. At the same time, part of the sound waves will be reflected by the first surface and return to the inside of the sound wedge. It can be understood that this part of the reflected sound waves will propagate toward the end of the second surface that is farther away from the first surface, that is, Figure 1 or Figure 2 The sound propagates towards the right end of the wedge.

[0054] Among them, at the end of the second surface farther from the first surface, the acoustic wedge also includes a connecting surface connecting the second surface and the first surface. Then, in this embodiment, a first sound absorbing layer is provided on the connecting surface, so that the first sound absorbing layer can at least absorb the sound waves emitted by the piezoelectric ceramic and reflected by the first surface, thereby preventing the sound waves from being repeatedly reflected inside the acoustic wedge.

[0055] Because the repeated reflection of sound waves inside the acoustic wedge will have an adverse effect on the sound waves emitted by the piezoelectric ceramic through the first surface, that is, it will have an adverse effect on the emission excitation of the piezoelectric ceramic. Therefore, this embodiment can eliminate the above-mentioned adverse effect by arranging a first sound absorbing layer on the connecting surface.

[0056] It can be understood that the connecting surface connects the second surface and the first surface at one end of the acoustic wedge, and then the first sound absorbing layer can be specifically arranged on the connecting surface in an area that can be illuminated by the sound waves reflected by the first surface; specifically, the connecting surface can generally be as follows Figure 1 or Figure 2 The connection surface shown is a right-angle type. Of course, according to actual needs, the connection surface can also be other shapes, and this embodiment does not limit this.

[0057] An embodiment of the present application provides an ultrasonic transducer, which includes an acoustic wedge and a shell that encapsulates the acoustic wedge, the acoustic wedge includes a first surface and a second surface that are oppositely arranged, wherein the second surface is encapsulated inside the shell, the second surface that is inclined relative to the first surface is provided with piezoelectric ceramics, and a backing is provided in the accommodating space between the second surface and the shell; then, the embodiment of the present application provides a first sound absorbing layer on the connecting surface of the second surface of the acoustic wedge at the end farther from the first surface.

[0058] It can be understood that the sound waves emitted by the piezoelectric ceramic will be emitted from the second surface to the first surface, wherein part of the sound waves will be emitted through the first surface, and part of the sound waves will be reflected by the first surface back to the inside of the sound wedge and reflected to the connecting surface connecting the second surface and the first surface. Then, in this embodiment, a first sound absorbing layer is provided on the connecting surface, and the first sound absorbing layer can absorb the part of the sound waves reflected to the connecting surface to prevent it from being repeatedly reflected inside the sound wedge, thereby solving the technical problem in the existing ultrasonic transducer that part of the sound waves emitted by the piezoelectric ceramic are repeatedly reflected inside the sound wedge, thereby causing an adverse effect on its emission excitation.

[0059] In one possible implementation, the connecting surface 13 includes a side wall portion 131 disposed perpendicularly to the first surface 11, and a plane portion 132 disposed parallel to the first surface 11; wherein the first sound absorbing layer 50 extends along the plane portion 132 and the side wall portion 131 from the ridge line where the plane portion 132 and the side wall portion 131 meet, respectively.

[0060] That is, in combination with the above description, the sound wedge is, for example, in an irregular block shape, wherein at the end of the second surface of the sound wedge that is farther away from the first surface, the connecting surface may include two parts, one of which is a side wall part perpendicular to the first surface, and the other part is a plane part opposite to and parallel to the first surface, and the plane part is specifically connected to the second surface.

[0061] That is, the plane part and the side wall part are connected to form a right angle structure, and then the first sound absorbing layer can extend along the plane part and the side wall part respectively from the ridge line where the plane part and the side wall part are connected.

[0062] In a specific embodiment, the extension length of the first sound absorbing layer 50 on the plane portion 132 and the side wall portion 131 at least covers the positions reached by a pair of sound waves emitted by the piezoelectric ceramic 20 at a beam angle M after being reflected by the first surface 11 .

[0063] First of all, it can be understood that when the piezoelectric ceramic emits sound waves, the energy of the ultrasonic rays along the extension line of the central axis of the piezoelectric ceramic (perpendicular to the surface of the piezoelectric ceramic) is the largest, and the sound wave energy in other directions gradually weakens; and the beam angle is the angle from the extension line of the central axis of the piezoelectric ceramic as the axis to the point where the energy intensity is reduced by half (-3dB). This angle is called the beam angle.

[0064] Therefore, in this embodiment, the extension lengths of the first sound absorbing layer in the plane part and the side wall part can be set as follows:

[0065] See also Figure 3Along the extension direction of the second surface, a pair of sound waves emitted at the two ends of the piezoelectric ceramic at a beam angle will reach the above-mentioned plane part and the side wall part respectively after being reflected by the first surface. Then, the extension length of the first sound absorbing layer on the plane part and the side wall part should at least cover the positions reached by the above-mentioned pair of sound waves after being reflected by the first surface.

[0066] For example, the sound waves emitted at a beam angle by one end of the piezoelectric ceramic along the extension direction of the second surface will reach point A of the plane part after being reflected by the first surface. Therefore, the first sound absorbing layer should cover at least point A along the extension length of the plane part from the ridgeline where the plane part and the side wall part meet. Similarly, the sound waves emitted at a beam angle by the other end of the piezoelectric ceramic along the extension direction of the second surface will reach point B of the side wall part after being reflected by the first surface. Therefore, the first sound absorbing layer should cover at least point B along the extension length of the side wall part from the ridgeline where the plane part and the side wall part meet.

[0067] That is to say, on the connection surface, the area covered by the first sound absorbing layer should at least include a reflection area where the sound waves emitted by the piezoelectric ceramic at a beam angle can be reflected.

[0068] In a possible implementation manner, the connection surface 13 is provided with a first groove 14 , and the first groove 14 is used to support the first sound absorbing layer 50 .

[0069] In this embodiment, it can be understood that a first groove can be provided on the connecting surface of the acoustic wedge, and then the first sound absorbing layer is specifically provided in the first groove.

[0070] Specifically, return to Figure 1 and Figure 2 Considering that the shell directly abuts against the side wall portion of the sound wedge, the first groove should be set at least on the side wall portion of the sound wedge, and the depth of the first groove should be consistent with the thickness of the first sound absorbing layer.

[0071] Of course, since the above-mentioned plane portion does not directly abut against the housing, it may or may not be provided with the first groove.

[0072] In a specific embodiment, the thickness of the first sound absorbing layer 50 is consistent with the half wavelength of the sound wave when propagating therein, and the first sound absorbing layer 50 is made of porous sound absorbing materials bonded and cured by epoxy resin.

[0073] In this embodiment, the thickness of the first sound absorbing layer may be specifically consistent with the half wavelength of the sound wave when propagating therein. Thus, it can be understood that in this way, the first sound absorbing layer can effectively absorb the reflected sound waves inside the sound wedge, which is equivalent to improving the transmittance of the side wall of the sound wedge to the sound waves, and avoiding the sound waves reflected by the first surface from forming interference waves inside the sound wedge.

[0074] The first sound absorbing layer of the present embodiment may be specifically formed by curing a porous sound absorbing material after being bonded with epoxy resin. The porous sound absorbing material may increase the attenuation of sound wave vibration and easily absorb sound waves.

[0075] In a specific embodiment, the porous sound absorbing material includes, for example, porous sound absorbing cork. That is, the porous sound absorbing cork or wood residue can be bonded and cured using epoxy resin to form the first sound absorbing layer 50 .

[0076] It can be understood that the first sound absorbing layer made of porous sound absorbing cork can not only absorb the reflected sound waves, but also has a certain elasticity and can be used as a buffer layer between the shell and the sound wedge.

[0077] In one possible implementation, a second sound absorbing layer 60 is provided on the side of the piezoelectric ceramic 20 facing away from the second surface 12; wherein the thickness of the second sound absorbing layer 60 is consistent with the half wavelength of the sound wave when propagating therein, and the second sound absorbing layer 60 is formed by bonding and curing a porous sound absorbing material with epoxy resin; and the porous sound absorbing material includes porous sound absorbing cork.

[0078] First of all, it should be explained that in the ultrasonic transducer, the backing has two purposes. One is to absorb the sound waves emitted back by the piezoelectric ceramic and reduce inherent noise; the other is to match with the piezoelectric ceramic and absorb the excess vibration energy of the piezoelectric ceramic so that the vibration of the piezoelectric ceramic decays as quickly as possible after there is no signal input, thereby increasing the bandwidth of the signal receiving probe.

[0079] However, in the existing ultrasonic transducer, only one backing layer is provided, and the ability to absorb the back sound waves is limited. The unabsorbed back sound waves will propagate into the acoustic wedge through the backing layer, and will also have an adverse effect on the emission excitation of the acoustic wedge.

[0080] Based on the above situation, in this embodiment, a second sound absorbing layer is arranged between the piezoelectric ceramic and the backing. Figure 2 , wherein the second sound absorbing layer can be formed by bonding and curing porous sound absorbing cork with epoxy resin, just like the first sound absorbing layer mentioned above.

[0081] By setting the second sound absorbing layer, the second sound absorbing layer can effectively absorb the back sound waves emitted by the piezoelectric ceramics, preventing them from propagating into the sound wedge through the backing; in addition, as mentioned above, the second sound absorbing layer has a certain elasticity, so that after no signal is input to the piezoelectric ceramics, it can also accelerate the attenuation of the vibration of the piezoelectric ceramics, that is, it also has a good inhibitory effect on the tailing effect of the piezoelectric ceramics, thereby greatly increasing the reflected echo signal. For example, after measurement, the echo signal can be increased from 4.25V to 9.7V.

[0082] Among them, combined Figure 1, a second groove 15 may be specifically provided on the second surface 12 of the acoustic wedge 10 , and then the piezoelectric ceramic 20 may be specifically provided in the second groove 15 .

[0083] Regarding the backing 40 mentioned above, in one possible implementation manner, the backing 40 is formed by mixing epoxy resin and tungsten powder and then curing the mixture.

[0084] In this embodiment, the backing can be specifically formed by mixing tungsten powder and epoxy resin and then curing them. The tungsten powder and epoxy resin are mixed to form a high acoustic impedance material. In this way, the back sound waves of the piezoelectric ceramic will be scattered multiple times after encountering tungsten powder particles in the backing, thereby consuming the energy of the sound waves and accelerating the attenuation of the sound waves.

[0085] In one specific implementation, the mass ratio of the epoxy resin to the tungsten powder can be specifically between 1:1 and 1:1.5, and after testing, the effect is better.

[0086] In a possible implementation manner, the housing 30 can be specifically milled from stainless steel, Figure 4 The housing 30 is provided with a filling hole 31, and the filling hole 31 is used to fill the mixture of the backing 40 before curing, wherein the cable 70 connected to the piezoelectric ceramic extends from the housing.

[0087] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

[0088] The block diagrams of the devices, apparatuses, equipment, and systems involved in this application are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagram. As will be appreciated by those skilled in the art, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open words, referring to "including but not limited to", and can be used interchangeably with them. The words "or" and "and" used here refer to the words "and / or" and can be used interchangeably with them, unless the context clearly indicates otherwise. The words "such as" used here refer to the phrase "such as but not limited to", and can be used interchangeably with them.

[0089] It should also be noted that in the apparatus, device and method of the present application, each component or each step can be decomposed and / or recombined. Such decomposition and / or recombination should be regarded as equivalent solutions of the present application.

[0090] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may 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 rather to the widest scope consistent with the principles and novel features disclosed herein.

[0091] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize that some variations, modifications, changes, additions and sub-combinations thereof should be included within the scope of protection of the present invention.

Claims

1. An ultrasonic transducer, It is characterized in that The ultrasonic transducer comprises: An acoustic wedge, comprising a first surface and a second surface arranged opposite to each other, wherein the second surface is inclined at a predetermined angle relative to the first surface; Piezoelectric ceramics, arranged on the second surface; A housing for encapsulating the acoustic wedge so that the second surface is encapsulated inside the housing; a backing disposed in a receiving space between the housing and the second surface; Wherein, at the end of the second surface which is farther from the first surface, the acoustic wedge includes 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 to absorb sound waves emitted from the piezoelectric ceramic and reflected by the first surface.

2. The ultrasonic transducer according to claim 1, It is characterized in that The connecting surface includes a side wall portion disposed perpendicularly to the first surface, and a plane portion disposed parallel to the first surface; The first sound absorbing layer extends from a ridge line where the plane portion and the side wall portion meet along the plane portion and the side wall portion respectively.

3. The ultrasonic transducer according to claim 2, It is characterized in that The extension lengths of the first sound absorbing layer on the plane portion and the side wall portion at least cover the positions reached by a pair of sound waves emitted by the piezoelectric ceramic at a beam angle after being reflected by the first surface.

4. The ultrasonic transducer according to claim 1, It is characterized in that The connection surface is provided with a first groove, and the first groove is used to carry the first sound absorbing layer.

5. The ultrasonic transducer according to claim 1, It is characterized in that The thickness of the first sound absorbing layer is consistent with the half wavelength of the sound wave when it propagates therein, and the first sound absorbing layer is formed by bonding and curing porous sound absorbing materials with epoxy resin.

6. The ultrasonic transducer according to claim 5, It is characterized in that The porous sound-absorbing material comprises porous sound-absorbing cork.

7. The ultrasonic transducer according to claim 1, It is characterized in that A second sound absorbing layer is provided on a side of the piezoelectric ceramic facing away from the second surface.

8. The ultrasonic transducer according to claim 7, It is characterized in that The thickness of the second sound absorbing layer is consistent with the half wavelength of the sound wave when it propagates therein, and the second sound absorbing layer is formed by bonding and curing porous sound absorbing materials with epoxy resin.

9. The ultrasonic transducer according to claim 8, It is characterized in that The porous sound-absorbing material comprises porous sound-absorbing cork.

10. The ultrasonic transducer according to claim 1, It is characterized in that The backing is formed by mixing epoxy resin and tungsten powder and then curing.

11. The ultrasonic transducer according to claim 10, It is characterized in that The mass ratio of the epoxy resin to the tungsten powder is between 1:1 and 1:1.

5.

12. The ultrasonic transducer according to claim 1, It is characterized in that The shell is provided with a filling hole, and the filling hole is used to fill the mixture of the backing before curing.

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