Double-frequency high-power liquid treatment ultrasonic transducer

Abstract

The embodiment of the invention relates to a double-frequency high-power liquid treatment ultrasonic transducer. According to the double-frequency high-power liquid treatment ultrasonic transducer, one end of an amplitude-change pole is connected with a sandwich type transducer to form a longitudinal displacement output structure; a mounting hole is formed in the side face of the metal round pipe, the metal round pipe and the amplitude-change pole are connected through a connecting piece arranged at the conical end of the amplitude-change pole through the mounting hole, and concave bending and stretching shells are arranged at the two ends of the metal round pipe correspondingly. A half-wavelength mode and a full-wavelength mode of the longitudinal displacement output structure enable radial vibration and axial vibration of the metal circular tube to form a complex-frequency working mode of the ultrasonic transducer. According to the embodiment of the invention, radial vibration and longitudinal vibration of the metal circular tube are respectively excited through a half-wavelength mode and a full-wavelength mode of the longitudinal displacement output structure, so that a double-frequency working mode of the ultrasonic transducer is realized; the concave flextensional shell amplifies the radial vibration displacement of the metal circular tube in the same phase, so that the acoustic radiation area of the axial vibration of the metal circular tube is increased, and the acoustic radiation power of the ultrasonic transducer and the uniformity of the radiation sound field of the transducer are improved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of ultrasonic transducers, and in particular to a dual-frequency high-power liquid processing ultrasonic transducer. Background Art

[0002] High-power ultrasound (HPU) is a green emerging technology with broad application prospects and great potential, and plays an important role in industrial production. It can be used to clean precision parts, remove surface dirt and oxides, and improve product quality and production efficiency. Ultrasonic transducers are the core components of HPU technology, and related research on their transmission efficiency, power capacity, and ultrasonic intensity is a hot topic in the industry. Currently, the most widely used in the field of high-power ultrasound is the sandwich piezoelectric transducer, which can realize the conversion between mechanical energy and electrical energy through the piezoelectric effect, and has the advantages of good mechanical strength, large vibration displacement, and high electromechanical efficiency.

[0003] The most widely used vibration elements are mostly round rods, round tubes or rings, round or rectangular plates and their combinations with stable or variable cross-sections. For example, a metal rod with a variable cross-section can be used as a horn to amplify the vibration displacement of the transducer in high-power applications, and a round tube, ring or spherical structure metal can be used as an ultrasonic radiator to generate different modes of vibration and increase the radiation range of the transducer.

[0004] The traditional complex frequency driven longitudinal-bending composite mode ultrasonic transducer has the following main problems: 1. The different electromechanical parameters under the common frequency of multiple vibration modes make it difficult to match the power supply; 2. The stress and vibration velocity distribution under multiple vibration modes are different, the displacement node positions are different, and mechanical fixation is difficult; 3. There is mutual coupling between multiple vibration modes. Existing rod-shaped and tube-shaped liquid treatment ultrasonic transducers can achieve strong radiated sound power through mode conversion between longitudinal vibration or longitudinal-radial vibration and have been widely used. However, the working principle of such rod-shaped and tube-shaped transducers is to generate radial sound radiation by longitudinally exciting the rod or tube. Since the longitudinal wave velocity in the rod or tube is large, the longitudinal wave wavelength is long, and the radiated sound field has large non-uniformity along the length of the rod or tube, and there is a large standing wave characteristic, and there is a situation of insufficient power.

[0005] Therefore, it is necessary to improve one or more problems existing in the above-mentioned related technical solutions.

[0006] It should be noted that this section is intended to provide background or context for the technical solutions of the present invention stated in the claims. The description herein is not admitted to be prior art by inclusion in this section. Summary of the invention

[0007] An object of the embodiments of the present invention is to provide a dual-frequency high-power liquid treatment ultrasonic transducer, thereby overcoming one or more problems caused by limitations and defects of the related art at least to a certain extent.

[0008] According to an embodiment of the present disclosure, a dual-frequency high-power liquid treatment ultrasonic transducer is provided, comprising:

[0009] It includes a sandwich transducer, a horn and a metal round tube;

[0010] The horn is formed by a stepped horn consisting of a conical part and a cylindrical part connected to a piezoelectric ceramic crystal along the longitudinal direction, and one end of the horn is connected to the sandwich transducer to form a longitudinal displacement output structure;

[0011] A mounting hole is provided on the side of the metal round tube, and the mounting hole connects the metal round tube to the horn through a connecting piece arranged on the top surface of the conical part of the horn, and both ends of the metal round tube are provided with a concave flextensional shell, and the concave part of the concave flextensional shell is arranged in the metal round tube;

[0012] The half-wavelength mode of the longitudinal displacement output structure causes the metal tube to vibrate radially, and the full-wavelength mode of the longitudinal displacement output structure causes the metal tube to vibrate axially, thereby forming a dual-frequency working mode of the ultrasonic transducer.

[0013] In one embodiment of the present invention, the sandwich transducer comprises a piezoelectric ceramic crystal stack, a metal block and a metal base, and the piezoelectric ceramic crystal stack, the metal block and the metal base are fixedly connected by stress bolts.

[0014] In one embodiment of the present invention, the piezoelectric ceramic crystal stack is formed by stacking multiple pieces of PZT-4.

[0015] In one embodiment of the present invention, in the sandwich transducer, the radius of the metal base is 15.5 mm-30.5 mm, the height of the metal base is 2 mm-32 mm, the radius of the metal block is 15.5 mm-30.5 mm, and the height of the metal block is 3 mm-33 mm.

[0016] In one embodiment of the present invention, in the amplitude transformer, the radius of the cylindrical portion is 15.5mm-30.5mm, the height of the cylindrical portion is 15mm-30mm, the radius of the top surface circle of the cone portion is 5mm-13mm, and the height of the cone portion is 45mm-65mm.

[0017] In one embodiment of the present invention, the inner diameter of the metal round tube is 33 mm-45 mm, the outer diameter of the metal round tube is 55 mm-74 mm, and the length of the metal round tube is 90 mm-100 mm.

[0018] In one embodiment of the present invention, the concave tensional shell is composed of a basin-shaped shell and a truncated cone, one end of the bottom of the basin-shaped shell is connected to one end of the large end surface of the truncated cone to form an integrated concave tensional shell, and the bottom of the basin shell and the truncated cone form the bottom of the concave tensional shell.

[0019] In one embodiment of the present invention, the bottom radius of the basin-shaped shell is 15mm-30mm, the small end face radius of the frustum is 2mm-15mm, the depth of the basin-shaped shell is 4mm-10mm, the bottom thickness of the concave flexural shell is 3mm-8mm, the side thickness of the basin-shaped shell is 2mm-5mm, and the basin edge thickness of the basin-shaped shell is 2mm-6mm.

[0020] In one embodiment of the present invention, the frequency of the half-wavelength mode is 14.5 KHz-16 KHz.

[0021] In one embodiment of the present invention, the frequency of the full-wavelength mode is 28KHz-30KHz.

[0022] The technical solution provided by the embodiments of the present invention may have the following beneficial effects:

[0023] The present invention provides a dual-frequency high-power liquid treatment ultrasonic transducer. On the one hand, the radial vibration and longitudinal vibration of a metal circular tube are respectively excited by the half-wavelength and full-wavelength modes of a longitudinal displacement output structure, thereby realizing a dual-frequency working mode of the ultrasonic transducer. On the other hand, the concave flexural shells at both ends of the metal circular tube amplify the radial vibration displacement of the metal circular tube in phase, thereby increasing the sound radiation area of ​​the axial vibration of the metal circular tube and improving the sound radiation power of the ultrasonic transducer and the uniformity of the radiated sound field. On the other hand, compared with traditional longitudinal tube-type or rod-type ultrasonic transducers, the metal circular tube with a longitudinal-diameter coupling arrangement as a radiator effectively reduces one-dimensional size, thereby making the ultrasonic transducer structure more compact. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0025] Figure 1 A schematic diagram showing the structure of a dual-frequency high-power liquid treatment ultrasonic transducer in an exemplary embodiment of the present invention is shown;

[0026] Figure 2A schematic cross-sectional view of the structure of a dual-frequency high-power liquid treatment ultrasonic transducer in an exemplary embodiment of the present invention is shown;

[0027] Figure 3 A schematic diagram showing a cross-section of a metal circular tube with a concave flextensional shell in an exemplary embodiment of the present invention is shown;

[0028] Figure 4 A schematic cross-sectional view of a concave flextensional shell in an exemplary embodiment of the present invention is shown;

[0029] Figure 5 A schematic diagram showing the 1 / 2 cross-section modeling of the longitudinal displacement output structure and the 1 / 4 cross-section modeling of the metal circular tube with the concave flextensional shell in the simulation experiment disclosed in the present invention is shown;

[0030] Figure 6 The first-order and second-order frequency vibration mode diagrams of the longitudinal displacement output structure in the simulation experiment disclosed in the present invention are shown;

[0031] Figure 7 The radial vibration and axial vibration mode shape diagrams of a metal circular tube with a concave flextensional shell in a simulation experiment disclosed in the present invention are shown.

[0032] Figure numerals: 100, metal round tube; 101, concave flexural shell; 200, amplitude transformer; 201, stepped amplitude transformer; 300, sandwich transducer; 301, metal block; 302, metal base; 400, piezoelectric ceramic crystal stack. DETAILED DESCRIPTION

[0033] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that the present invention will be more comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0034] In addition, the accompanying drawings are only schematic illustrations of embodiments of the present invention and are not necessarily drawn to scale. The same reference numerals in the drawings represent the same or similar parts, and their repeated descriptions will be omitted. Some of the block diagrams shown in the accompanying drawings are functional entities and do not necessarily correspond to physically or logically independent entities.

[0035] This example embodiment provides a dual-frequency high-power liquid processing ultrasonic transducer, referring to Figure 1 As shown, the dual-frequency high-power liquid treatment ultrasonic transducer may include: a metal round tube 100 , a horn 200 and a sandwich transducer 300 .

[0036] The horn 200 is formed by a stepped horn 201 composed of a conical part and a cylindrical part connected to a piezoelectric ceramic crystal along the longitudinal direction, and one end of the horn 200 is connected to the sandwich transducer 300 to form a longitudinal displacement output structure;

[0037] The side of the metal round tube 100 is provided with a mounting hole, and the mounting hole connects the metal round tube 100 with the horn 200 through a connecting piece arranged on the top circular surface of the conical part of the horn 200. Both ends of the metal round tube 100 are provided with a concave flextensional housing 101, and the concave part of the concave flextensional housing 101 is arranged in the metal round tube 100;

[0038] The half-wavelength mode of the longitudinal displacement output structure causes the metal tube 100 to vibrate radially, and the full-wavelength mode of the longitudinal displacement output structure causes the metal tube 100 to vibrate axially, thereby forming a dual-frequency working mode of the ultrasonic transducer.

[0039] It should be understood that, compared with traditional longitudinal tube-type or rod-type ultrasonic transducers, the metal round tube 100 of the present application is connected to the amplitude transformer 200 as a radiator with a longitudinal diameter, which effectively reduces the one-dimensional size and makes the ultrasonic transducer structure more compact.

[0040] It should also be understood that the sandwich transducer 300 is a longitudinal sandwich piezoelectric ultrasonic transducer.

[0041] It is also necessary to understand that, in the longitudinal displacement output structure composed of the sandwich transducer 300 and the horn 200 and the metal circular tube 100 with the concave flextensional shell 101, the first-order axial frequency of the longitudinal displacement output structure is approximately equal to the radial frequency of the metal circular tube 100 with the concave flextensional shell 101, so that the radial vibration of the metal circular tube 100 with the concave flextensional shell 101 is excited by the first-order axial frequency of the longitudinal displacement output structure, and the second-order axial frequency of the longitudinal displacement output structure is approximately equal to the axial frequency of the metal circular tube 100 with the concave flextensional shell 101, and the axial vibration of the metal circular tube 100 with the concave flextensional shell 101 is excited by the second-order axial frequency of the longitudinal displacement output structure.

[0042] Through the dual-frequency high-power liquid processing ultrasonic transducer, on the one hand, the radial vibration and longitudinal vibration of the metal tube 100 are respectively excited by the half-wavelength and full-wavelength modes of the longitudinal displacement output structure, thereby realizing the dual-frequency working mode of the ultrasonic transducer; on the other hand, the concave flexural shells 101 at both ends of the metal tube 100 amplify the radial vibration displacement of the metal tube 100 in phase, thereby increasing the sound radiation area of ​​the axial vibration of the metal tube 100 and improving the sound radiation power of the ultrasonic transducer and the uniformity of the radiated sound field; on the other hand, compared with the traditional longitudinal tube-type or rod-type ultrasonic transducer, the metal tube 100 with a longitudinal diameter is connected to the amplitude transformer 200 as a radiator, which effectively reduces the one-dimensional size and makes the ultrasonic transducer structure more compact.

[0043] Next, we will refer to Figures 1 to 6 The various parts of the above-mentioned dual-frequency high-power liquid processing ultrasonic transducer in this example embodiment are described in more detail.

[0044] In one embodiment, the sandwich transducer 300 includes a piezoelectric ceramic crystal stack 400, a metal block 301 and a metal base 302, and the piezoelectric ceramic crystal stack 400, the metal block 301 and the metal base 302 are fixedly connected by stress bolts. The piezoelectric ceramic crystal stack 400 is formed by stacking multiple pieces of PZT-4. It should be understood that by cascading the piezoelectric ceramic crystal stack 400 and the stepped amplitude rod 201, a higher vibration displacement output and a larger power capacity are achieved compared to the traditional sandwich transducer. It should also be understood that the piezoelectric ceramic crystal stack 400 adopts PZT-4, which is stacked by 4 pieces of PZT-4. PZT-4 has good stability, high precision, high energy conversion efficiency, fast response speed, and the mechanical quality factor, piezoelectric coefficient, and electromechanical coupling constant are significantly better than lead-free piezoelectric ceramic crystal stacks.

[0045] In one embodiment, in the sandwich transducer 300, the radius of the metal base 302 is R1, 15.5mm≤R1≤30.5mm, the height of the metal base 302 is L1, 2mm≤L1≤32mm, the radius of the metal block 301 is R4, 15.5mm≤R4≤30.5mm, the height of the metal block 301 is L3, and 3mm≤L3≤33mm. It should be understood that the piezoelectric ceramic crystal stack 400 adopts PZT-4, which is stacked by multiple pieces of PZT-4, the inner diameter of each PZT-4 is R2=8mm, the outer diameter of each PZT-4 is R3=25mm, and the height of each PZT-4 is L2=5mm. The sandwich transducer 300 and the horn 200 are connected in series along the longitudinal mechanical end to form a longitudinal displacement output structure of the ultrasonic transducer. By changing the geometrical dimensions of the longitudinal displacement output structure and the relative positions of the two groups of piezoelectric ceramic crystal stacks 400, both the fundamental frequency half-wavelength mode and the first harmonic frequency full-wavelength mode of the longitudinal vibration have a larger effective electromechanical coupling coefficient.

[0046] In one embodiment, in the horn 200, the radius of the cylindrical part is R5, 15.5mm≤R5≤30.5mm, the height of the cylindrical part is L4, 15mm≤L4≤30mm, the radius of the top circle of the cone part is R6, 5mm≤R6≤13mm, and the height of the cone part is L5, 45mm≤L5≤65mm. It should be understood that the horn 200 is formed by connecting the stepped horn 201 composed of the conical part and the cylindrical part with the piezoelectric ceramic crystal in the longitudinal direction, and the power capacity and secondary amplification of the longitudinal vibration displacement output of the sandwich transducer 300 are increased by the horn 200. The conical part of the horn 200 reduces the connection area of ​​the amplified output end of the vibration displacement with the metal tube 100, which is more conducive to exciting the pure radial vibration and axial vibration of the metal tube 100. The introduction of the piezoelectric ceramic crystal stack 400 in the horn 200 is intended to further increase the power capacity and longitudinal displacement output of the ultrasonic transducer.

[0047] In one embodiment, Figure 3-Figure 4 As shown, the inner diameter of the metal tube 100 is R7, 33mm≤R7≤45mm, the outer diameter of the metal tube 100 is R8, 55mm≤R8≤74mm, and the length of the metal tube 100 is L6, 90mm≤L6≤100mm. It should be understood that by designing the geometric dimensions of the metal tube 100 so that its radial vibration frequency and axial vibration frequency are approximately equal to the fundamental frequency and the first harmonic frequency of the longitudinal displacement output system, respectively, the half-wavelength mode of the longitudinal displacement output system excites the radial vibration of the metal tube 100, corresponding to the low-frequency mode of the ultrasonic transducer. The full-wavelength mode of the longitudinal displacement output system excites the axial vibration of the metal tube 100, corresponding to the high-frequency mode of the ultrasonic transducer, thereby realizing the complex frequency working mode of the ultrasonic transducer. When the half-wavelength mode of the longitudinal displacement output structure excites the radial vibration of the metal tube 100, the ultrasonic transducer is in a low-frequency mode. At this time, the radial vibration of the metal tube 100 drives the concave flextensional shell 101 to generate flextensional vibration. The radial vibration displacement of the metal tube 100 is amplified by the concave flextensional shell 101 to generate a larger axial displacement (ΔS A >ΔS R ). When the metal tube 100 stretches and contracts radially, the concave flextensional shell 101 stretches and contracts in phase, and the radiated sound pressures of the metal tube 100 and the concave flextensional shell 101 in the sound field are superimposed in phase, thereby the metal tube 100 and the concave flextensional shell 101 radiate in phase with high power. When the full-wavelength mode of the longitudinal displacement output structure excites the axial vibration of the metal tube 100, the ultrasonic transducer is in a high-frequency mode, and the concave flextensional shell 101 serves as the sound radiation surface of the axial vibration of the metal tube 100, which increases the end face radiation area of ​​the axial vibration of the metal tube 100, improves the sound radiation efficiency of the ultrasonic transducer, and enables the ultrasonic transducer to achieve high-power radiation in both working modes.

[0048] In one embodiment, Figure 3 As shown, the concave flextensional shell 101 is composed of a basin-shaped shell and a truncated cone, one end of the basin bottom of the basin-shaped shell is connected to one end of the large end face of the truncated cone to form an integrated concave flextensional shell 101, and the bottom of the basin-shaped shell and the truncated cone form the bottom of the concave flextensional shell 101. The basin bottom radius of the basin-shaped shell is R9, 15mm≤R9≤30mm, the small end face radius of the truncated cone is R10, 2mm≤R10≤15mm, the depth of the basin-shaped shell is h1, 4mm≤h1≤10mm, the thickness of the bottom of the concave flextensional shell 101 is h2, 3mm≤h2≤8mm, the side thickness of the basin-shaped shell is h3, and 2mm≤h3≤5mm, and the basin edge thickness of the basin-shaped shell is h4, and 2mm≤h4≤6mm. It should be understood that the concave flextensional shell 101 is added to the outside of both ends of the metal round tube 100 radiator, and the various parts of the concave flextensional shell 101 will adopt different thicknesses to meet the functional requirements of different sections, especially the bottom area of ​​the concave flextensional shell 101, which also adopts unequal thickness of the frustum. The radial vibration of the metal round tube 100 is stimulated by the first-order longitudinal vibration of the longitudinal vibration system, driving the flextensional structure, and the axial vibration of the metal round tube 100 is stimulated by the second-order longitudinal vibration of the longitudinal vibration system, driving the flextensional structure, and meeting the high-power radiation at the same time.

[0049] It should also be understood that R and R′ are the radius of the upper end of the basin-shaped shell of the concave flextensional shell before and after the metal tube stretches, and the upper end of the basin-shaped shell is the end corresponding to the bottom of the basin-shaped shell, that is, ΔS R is the change in radius corresponding to the upper end of the basin-shaped shell of the concave flextensional shell before and after the metal tube stretches;

[0050] r is the size of the inner diameter of the concave flat bottom of the flex-tensional shell, that is, the radius of the bottom of the basin-shaped shell. It can be assumed that the metal circular tube remains unchanged before and after stretching;

[0051] L is the length of the inverted cone of the flexural shell, that is, the side length of the basin-shaped shell. It is also assumed that the metal tube remains unchanged before and after stretching;

[0052] h and h′ are respectively the depth of the concave surface of the concave flexural shell before and after the metal tube stretches, that is, the depth of the basin-shaped shell of the concave flexural shell before and after the metal tube stretches.

[0053] ΔS A is the change in the depth of the concave surface of the concave flexural shell before and after the metal tube stretches;

[0054] According to the model, we have: ΔS R=R′-R, ΔS A =h′-h

[0055] According to the state of the metal tube before it is stretched: (Rr)2+h2=L2

[0056] According to the state of the metal tube after stretching: (R'-r)2+h'2=L2

[0057] Then: (Rr)2+h2=(R′-r)2+h′2

[0058] ΔR=R′-R、ΔS A =h′-hSubstitute (Rr)2+h2=(R′-r)2+h′2

[0059] Arranged

[0060] Continue to organize

[0061] Ignore ΔR 2 Infinitely small quantities, we can get:

[0062]

[0063] To obtain ΔSA>ΔSR, it is necessary to control the depth h of the concave shell so that the values ​​of R and Rr are much larger than h, thereby being able to excite the radial vibration of the piezoelectric metal tube to produce a larger amplitude vibration of the flexural shell.

[0064] In one embodiment, the frequency of the half-wavelength mode is 14.5KHz-16KHz, and the frequency of the full-wavelength mode is 28KHz-30KHz. It should be understood that the half-wavelength and full-wavelength modes of the longitudinal displacement output structure formed by the sandwich transducer 300 and the horn 200 respectively excite the radial vibration and longitudinal vibration of the metal tube 100, realizing the dual-frequency working mode of the ultrasonic transducer. The concave flexural shell 101 amplifies the radial vibration displacement of the metal tube 100 in phase, increases the sound radiation area of ​​the axial vibration of the metal tube 100, and can effectively improve the sound radiation power of the ultrasonic transducer. The amplified output end of the conical horn 200 vibration displacement reduces the connection area with the metal tube 100, which is more conducive to exciting the pure radial vibration and axial vibration of the metal tube 100.

[0065] In order to further verify the effect of the dual-frequency high-power liquid treatment ultrasonic transducer proposed in the present disclosure, the following simulation experiments were conducted:

[0066] In the simulation experiment, in the longitudinal sandwich piezoelectric ultrasonic transducer, the radius R1 of the metal base 302 is 25.5 mm, the height L1 is 20 mm, the piezoelectric ceramic ring, i.e., the inner diameter R2 is 8 mm, the outer diameter R3 is 25 mm, the height L2 is 5 mm, and the radius R4 of the metal block 301 is 25.5 mm, and the height L3 is 15 mm.

[0067] In the horn 200, the radius of the cylindrical part is R5 = 25.5 mm, the height is L4 = 21 mm, the radius of the upper circular surface of the cone part is R6 = 9 mm, and the height is L5 = 54 mm.

[0068] In the metal round tube 100 , the inner diameter R7 of the round tube is 44 mm, the outer diameter R8 is 60 mm, and the height L6 is 96 mm.

[0069] In the concave flextensional shell 101, the bottom radius of the basin-shaped shell is R9=30mm, the small end face radius of the frustum is R10=15mm, the depth of the basin-shaped shell is h1=6mm, the bottom thickness of the concave flextensional shell 101 is h2=5mm, the side thickness of the basin-shaped shell is h3=2.33mm, and the basin edge thickness of the basin-shaped shell is h4=2mm.

[0070] The half-wavelength mode of the longitudinal displacement output structure is 15198 Hz, corresponding to the first-order frequency of the longitudinal displacement output structure, and the full-wavelength mode of the longitudinal displacement output structure is 28786 Hz, corresponding to the second-order frequency of the longitudinal displacement output structure.

[0071] In the longitudinal displacement output structure composed of the sandwich transducer 300 and the horn 200 and the longitudinal-diameter coupled vibration metal tube 100 with the concave flextensional shell 101, the first-order axial frequency of the longitudinal displacement output structure is approximately equal to the radial frequency of the metal tube 100 with the concave flextensional shell 101, and the second-order axial frequency of the longitudinal displacement output structure is approximately equal to the axial frequency of the metal tube 100 with the concave flextensional shell 101, so that the radial vibration of the metal tube 100 with the concave flextensional shell 101 is excited by the first-order axial frequency of the longitudinal displacement output structure, and the axial vibration of the metal tube 100 with the concave flextensional shell 101 is excited by the second-order axial frequency of the longitudinal displacement output structure.

[0072] like Figure 5 As shown, Figure 5 The left side shows the 1 / 2 cross-section modeling of the longitudinal displacement output structure. Figure 5 A quarter cross section of a metal circular tube 100 with a concave flextensional shell 101 is modeled on the right.

[0073] like Figure 6 As shown, Figure 6 The left side shows the first-order frequency of the longitudinal displacement output structure, which is 15198Hz. Figure 6 The second-order frequency of the longitudinal displacement output structure on the right is 28786Hz.

[0074] like Figure 7 As shown, Figure 7 The left side is the radial vibration mode diagram of the metal tube 100 with the concave flextensional shell 101. The radial frequency is 15446 Hz. When the half-wavelength mode of the longitudinal displacement output structure excites the radial vibration of the metal tube 100, the ultrasonic transducer is in the low-frequency mode. At this time, the radial vibration of the metal tube 100 generates flextensional vibration with the concave flextensional shell 101. The radial vibration displacement of the metal tube 100 is amplified by the concave flextensional shell 101 to produce a larger axial displacement, and the displacement ΔS A 0.107796e - 8 m, displacement ΔS R 0.520499e -10 m, satisfying ΔS A >ΔS R When the metal tube 100 radially expands and contracts, the flextensional amplification mechanism expands and contracts in phase, and the radiation sound pressures of the metal tube 100 and the concave flextensional shell 101 in the sound field are superimposed in phase, thereby achieving in-phase high-power radiation of the metal tube 100 and the concave flextensional shell 101.

[0075] Figure 7 The right side shows the axial vibration mode diagram of the metal tube 100 with the concave flextensional shell 101, and the axial frequency is 28898Hz. When the full wavelength mode of the longitudinal displacement output structure excites the axial vibration of the metal tube 100, the ultrasonic transducer is in the high-frequency mode. The concave flextensional shell 101 serves as the sound radiation surface of the axial vibration of the metal tube 100, which increases the end face radiation area of ​​the axial vibration of the metal tube 100, improves the sound radiation efficiency of the ultrasonic transducer, and enables the ultrasonic transducer to achieve high-power radiation in both working modes.

[0076] It should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like in the above description indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present invention.

[0077] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0078] In the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0079] In the embodiments of the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0080] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0081] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses or adaptations of the present invention, which follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present invention are indicated by the appended claims.

Claims

1. A dual-frequency high-power liquid treatment ultrasonic transducer, comprising a sandwich transducer, a horn and a metal round tube, characterized in that: The horn is formed by a stepped horn consisting of a conical part and a cylindrical part connected to a piezoelectric ceramic crystal along the longitudinal direction, and one end of the horn is connected to the sandwich transducer to form a longitudinal displacement output structure; A mounting hole is provided on the side of the metal round tube, and the mounting hole connects the metal round tube to the horn through a connecting piece arranged on the top surface of the conical part of the horn, and both ends of the metal round tube are provided with a concave flextensional shell, and the concave part of the concave flextensional shell is arranged in the metal round tube; The half-wavelength mode of the longitudinal displacement output structure causes the metal tube to vibrate radially, and the full-wavelength mode of the longitudinal displacement output structure causes the metal tube to vibrate axially, thereby forming a dual-frequency working mode of the ultrasonic transducer.

2. The dual-frequency high-power liquid treatment ultrasonic transducer according to claim 1, characterized in that: The sandwich transducer comprises a piezoelectric ceramic crystal stack, a metal block and a metal base, wherein the piezoelectric ceramic crystal stack, the metal block and the metal base are fixedly connected by stress bolts.

3. The dual-frequency high-power liquid treatment ultrasonic transducer according to claim 2, characterized in that: The piezoelectric ceramic crystal stack is formed by stacking multiple pieces of PZT-4.

4. The dual-frequency high-power liquid treatment ultrasonic transducer according to claim 2, characterized in that: In the sandwich transducer, the radius of the metal base is 15.5 mm-30.5 mm, the height of the metal base is 2 mm-32 mm, the radius of the metal block is 15.5 mm-30.5 mm, and the height of the metal block is 3 mm-33 mm.

5. The dual-frequency high-power liquid treatment ultrasonic transducer according to claim 1, characterized in that: In the amplitude transformer, the radius of the cylindrical part is 15.5mm-30.5mm, the height of the cylindrical part is 15mm-30mm, the radius of the top surface circle of the cone part is 5mm-13mm, and the height of the cone part is 45mm-65mm.

6. The dual-frequency high-power liquid treatment ultrasonic transducer according to claim 1, characterized in that: The inner diameter of the metal round tube is 33mm-45mm, the outer diameter of the metal round tube is 55mm-74mm, and the length of the metal round tube is 90mm-100mm.

7. The dual-frequency high-power liquid treatment ultrasonic transducer according to claim 1, characterized in that: The concave flextensional shell is composed of a basin-shaped shell and a truncated cone. One end of the bottom of the basin-shaped shell is connected to one end of the large end surface of the truncated cone to form an integrated concave flextensional shell. The bottom of the basin-shaped shell and the truncated cone form the bottom of the concave flextensional shell.

8. The dual-frequency high-power liquid treatment ultrasonic transducer according to claim 7, characterized in that: The bottom radius of the basin-shaped shell is 15mm-30mm, the small end face radius of the frustum is 2mm-15mm, the depth of the basin-shaped shell is 4mm-10mm, the bottom thickness of the concave bending shell is 3mm-8mm, the side thickness of the basin-shaped shell is 2mm-5mm, and the basin edge thickness of the basin-shaped shell is 2mm-6mm.

9. The dual-frequency high-power liquid treatment ultrasonic transducer according to claim 1, characterized in that: The frequency of the half-wavelength mode is 14.5 KHz-16 KHz.

10. The dual-frequency high-power liquid treatment ultrasonic transducer according to claim 1, characterized in that: The frequency of the full-wavelength mode is 28KHz-30KHz.

Images