CN112337774A - PMNT ultrasonic wave deicing transducer based on front and back end vibration velocity optimization - Google Patents
PMNT ultrasonic wave deicing transducer based on front and back end vibration velocity optimization Download PDFInfo
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Abstract
The invention discloses a PMNT ultrasonic deicing transducer based on front and rear end vibration velocity optimization, which comprises a front cover plate and a rear cover plate; the piezoelectric device also comprises two piezoelectric patches clamped between the front cover plate and the rear cover plate; electrode plates are padded between the front cover plate and the piezoelectric patches, between the two piezoelectric patches and between the rear cover plate and the piezoelectric patches; the rear cover plate, the piezoelectric sheet and the electrode plate are all provided with through concentric round holes, one surface of the front cover plate facing the electrode plate is provided with threaded holes corresponding to the concentric round holes, and the concentric round holes and the threaded holes are sequentially connected to form a connecting channel; the bolt enters the connecting channel from the direction of the rear cover plate and is in threaded connection with the threaded hole. The invention has the design advantages of stable output, large power capacity and the like, simultaneously, the overall structure of the transducer is optimally designed, so that the volume and the weight of the sandwich type piezoelectric transducer are greatly reduced, meanwhile, sound waves generated by the vibration of the piezoelectric plate directly enter the skin through the motor plate, and the loss of ultrasonic energy is greatly reduced.
Description
Technical Field
The invention relates to the technical field of ultrasonic deicing, in particular to a thickness vibration type PMNT sandwich piezoelectric transducer.
Background
With the development of aviation technology, airplanes become one of important travel and transportation modes, and flight safety is always a focus problem in the aviation field. Investigation finds that the icing of the airplane is one of the important reasons causing the accident and the accident of the airplane, the ice accumulation of the airplane generates great threat to the flight safety, the existing deicing method is unsatisfactory in the aspects of energy consumption, weight and the like, various places requiring improvement exist, and the aviation field urgently needs to find a breakthrough and more effective deicing method. The ultrasonic deicing is a novel deicing method, and the basic principle of the deicing is as follows: when ultrasonic waves propagate between the skin of an aircraft and the ice layer, a velocity difference is generated at the interface of the skin and the ice due to different properties of propagation media, and the velocity difference further generates an interface shear force. Ice can be removed from the skin when the interfacial shear forces generated exceed the ice-to-plate bond strength.
The ultrasonic waves may be generated by a piezoelectric transducer. The piezoelectric transducer is a device which exchanges electric energy with mechanical energy and sound energy by utilizing the piezoelectric and inverse piezoelectric effects of piezoelectric materials. None of the existing transducers are designed for de-icing purposes and are therefore unsatisfactory in terms of performance, volume, weight, etc.
Typically, piezoelectric material based transducers include flexural vibration mode transducers, sandwich thickness vibration type transducers, torsional vibration mode transducers, and the like.
Bending vibration transducers, most commonly plate bending, with a mode of vibration closer to the drum's simple boundary vibration, are based on the principle of gluing together two piezoelectric plates of opposite polarization, and when an alternating voltage is applied to the plates, the stretching deformation of the upper and lower plates will eventually be converted into bending vibration of the transducer. In engineering, a metal sheet and a piezoelectric ceramic sheet are usually combined to form a vibrating plate, and the vibrating plate is directly used as an acoustic radiating surface. The bending vibration transducer has the advantages of small volume, light weight and the like; however, since the bending vibrator of the transducer needs a certain vibration space, when vibration sound waves pass through air and then enter the plate from the air, the phenomena of reflection, re-reflection and the like occur, and a large energy loss exists in the process, so that the energy really transmitted into the plate is greatly reduced, and the effect is not obvious when the transducer is adhered to the plate surface for deicing.
The sandwich thickness vibration type piezoelectric transducer is more than one type, the design theory thereof tends to mature, and the principle is the simplest: as shown in fig. 1, the PZT sandwich transducer can generate sound by vibration after applying an alternating voltage to the upper and lower surfaces of a piezoelectric sheet polarized in the thickness direction via electrodes. In order to improve the sound radiation efficiency, the ultrasonic directivity, increase the frequency bandwidth and other purposes in the actual engineering, components such as a front radiation head, a transition layer, a back plate wave-absorbing material and the like are added to the piezoelectric patch. For airplane deicing, the thickness vibration type transducer can be conveniently installed and taken down, and energy emitted by the piezoelectric vibrator directly enters the plate through a solid and solid transmission mode, so that excessive ultrasonic energy loss is avoided. The commonly used sandwich thickness vibration type transducer has stable output and large power capacity.
Therefore, it is an urgent need to solve the problem of the art to provide a piezoelectric transducer that can maintain the advantages of the sandwich thickness vibration type piezoelectric transducer and further optimize the volume and weight of the transducer.
Disclosure of Invention
In view of this, the present invention provides a PMNT ultrasonic deicing transducer based on front and rear end vibration velocity optimization, and aims to solve the above technical problems.
In order to achieve the purpose, the invention adopts the following technical scheme:
a PMNT ultrasonic deicing transducer based on front and rear end vibration velocity optimization comprises a front cover plate and a rear cover plate; the piezoelectric device also comprises two piezoelectric patches clamped between the front cover plate and the rear cover plate; electrode plates are padded between the front cover plate and the piezoelectric patches, between the two piezoelectric patches and between the rear cover plate and the piezoelectric patches; the rear cover plate, the piezoelectric sheet and the electrode plate are all provided with through concentric round holes, one surface of the front cover plate, facing the electrode plate, is provided with threaded holes corresponding to the concentric round holes, and the concentric round holes and the threaded holes are sequentially connected to form a connecting channel; and the bolt enters the connecting channel from the direction of the rear cover plate and is in threaded connection with the threaded hole.
Through the technical scheme, the design of the sandwich type thickness vibration type energy converter aims at the requirement of airplane deicing, the overall structure of the energy converter is optimally designed while the design advantages of stable output, large power capacity and the like of the sandwich type thickness vibration type energy converter are inherited, the size and the weight of the sandwich type piezoelectric energy converter are greatly reduced, meanwhile, when an ultrasonic power supply is turned on, sound waves generated by vibration of the piezoelectric plate directly enter the interior of a skin through the motor plate, and the loss of ultrasonic energy is greatly reduced.
Preferably, in the PMNT ultrasonic deicing transducer optimized based on the front-end and rear-end vibration velocities, the piezoelectric sheet is a PMNT piezoelectric ceramic. The piezoelectric sheet often determines the power of the transducer, PMNT piezoelectric ceramics are selected as the material of the piezoelectric sheet for obtaining better deicing effect, the electromechanical coupling coefficient of the material is more than 0.7, and the piezoelectric sheet has great advantages on piezoelectric coefficient, electromechanical conversion efficiency and strain quantity.
Preferably, in the PMNT ultrasonic deicing transducer optimized based on the front-end and rear-end vibration speeds, the two piezoelectric sheets are equal in size, 5mm in thickness and 20mm in outer diameter. The volume and weight thereof can be reduced.
Preferably, in the above PMNT ultrasonic deicing transducer optimized based on front and rear end vibration velocities, the inner wall of the concentric circular hole on the rear cover plate is provided with threads matched with the bolt. The stability of connection structure is improved, and the pretightning force between front shroud and the back shroud can be adjusted.
Preferably, in the PMNT ultrasonic deicing transducer optimized based on the front-end and rear-end vibration velocities, the bolt is M6 standard, the diameter of the bolt is 6mm, and the material is 40 Cr. Can meet the use requirements of structural strength and size.
Preferably, in the above PMNT ultrasonic deicing transducer optimized based on front and rear end vibration velocities, the inner diameters of the concentric circular holes on the piezoelectric sheet and the electrode sheet are 8 mm. To avoid electrical conduction or friction from contact with the bolt.
Preferably, in the PMNT ultrasonic deicing transducer optimized based on the front-end and rear-end vibration velocities, the space between the rear cover plate and the electrode sheet, the space between the electrode sheet and the piezoelectric sheet, and the space between the electrode sheet and the front cover plate are bonded by epoxy resin glue. The stability of the connection structure is improved.
Preferably, in the PMNT ultrasonic deicing transducer optimized based on the front-end and rear-end vibration velocities, the electrode plate is 0.5mm thick and made of brass; the electrode plate between the two piezoelectric plates is a positive electrode, and the electrode plate between the rear cover plate and the piezoelectric plate and the electrode plate between the piezoelectric plate and the front cover plate are negative electrodes. The power-on requirement of connection can be met.
Preferably, in the PMNT ultrasonic deicing transducer optimized based on front and rear end vibration speeds, the material of the rear cover plate is 45 # steel, and the inner and outer diameters of the rear cover plate are equal to those of the piezoelectric sheets; the length of the back cover plate is 16.7 mm. The volume and weight thereof can be reduced.
Preferably, in the PMNT ultrasonic deicing transducer optimized based on front and rear end vibration velocities, the front cover plate is made of aluminum-magnesium alloy, and the front cover plate is horn-shaped; the outer diameter of one end, facing the electrode plate, of the front cover plate is 20mm and is the same as that of the piezoelectric plate, and the diameter of one end, far away from the electrode plate, of the front cover plate is 26.6 mm; the length of the front cover plate is 17.3 mm. The volume and weight thereof can be reduced.
Through the technical scheme, compared with the prior art, the invention discloses the PMNT ultrasonic deicing transducer based on front-end and rear-end vibration velocity optimization, and the PMNT ultrasonic deicing transducer has the following beneficial effects:
1. the design of the invention focuses on the requirement of airplane deicing, and the structural size of the sandwich type thickness vibration type energy converter is optimally designed while the design advantages of stable output, large power capacity and the like of the sandwich type thickness vibration type energy converter are inherited, so that the volume and the weight of the sandwich type piezoelectric energy converter are greatly reduced.
2. When the ultrasonic power supply is turned on, sound waves generated by vibration of the piezoelectric plate directly enter the skin through the front gasket, and the loss of ultrasonic energy is greatly reduced.
3. The designed piezoelectric transducer adopts PMNT materials, has excellent performance and larger transducer power.
4. The transducer is easy to process, assemble and install, and has a huge application prospect.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
FIG. 1 is a front view of a conventional PZT transducer;
FIG. 2 is a schematic diagram of a PMNT ultrasonic deicing transducer based on front-end and rear-end vibration velocity optimization according to the present invention;
FIG. 3 is a front view of a PMNT ultrasonic deicing transducer structure based on front and rear end vibration velocity optimization according to the present invention;
FIG. 4 is a diagram of a model of a PMNT ultrasonic deicing transducer deicing based on front-end and rear-end vibration velocity optimization according to the present invention;
FIG. 5 is a graph of stress amplitude at a point under excitation of a PMNT ultrasonic deicing transducer optimized based on front and rear end vibration velocities according to the present invention as a function of frequency;
FIG. 6 is a diagram of an XY shear stress distribution diagram of a plate ice interface under excitation of an optimal frequency of the PMNT ultrasonic deicing transducer based on front-end and rear-end vibration velocity optimization.
Wherein:
1-front cover plate;
2-rear cover plate;
3-a piezoelectric sheet;
4-electrode slice;
5-an adaptor channel;
6-bolt;
7-PZT sandwich transducer.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to fig. 2 and fig. 3, the embodiment of the invention discloses a PMNT ultrasonic deicing transducer based on front and rear end vibration velocity optimization, comprising a front cover plate 1 and a rear cover plate 2; the piezoelectric device also comprises two piezoelectric patches 3 which are clamped between the front cover plate 1 and the rear cover plate 2; electrode plates 4 are padded between the front cover plate 1 and the piezoelectric patches 3, between the two piezoelectric patches 3 and between the rear cover plate 2 and the piezoelectric patches 3; the rear cover plate 2, the piezoelectric sheet 3 and the electrode sheet 4 are all provided with through concentric round holes, one surface of the front cover plate 1 facing the electrode sheet 4 is provided with threaded holes corresponding to the concentric round holes, and the concentric round holes and the threaded holes are sequentially connected to form a connecting channel 5; the bolt 6 enters the connecting channel 5 from the direction of the rear cover plate 2 and is in threaded connection with the threaded hole.
In order to further optimize the technical scheme, the piezoelectric sheet 3 is PMNT piezoelectric ceramic.
In order to further optimize the technical scheme, the two piezoelectric sheets 3 are equal in size, 5mm in thickness and 20mm in outer diameter.
In order to further optimize the technical scheme, the inner wall of the concentric circular hole on the rear cover plate 2 is provided with threads matched with the bolt 6.
In order to further optimize the technical scheme, the bolt 6 is in an M6 specification, the diameter of the bolt 6 is 6mm, and the material is 40 Cr.
In order to further optimize the technical scheme, the inner diameters of the concentric circular holes on the piezoelectric sheet 3 and the electrode sheet 4 are 8 mm.
In order to further optimize the technical scheme, the rear cover plate 2 and the electrode plate 4, the electrode plate 4 and the piezoelectric plate 3, and the electrode plate 4 and the front cover plate 1 are bonded through epoxy resin glue.
In order to further optimize the technical scheme, the thickness of the electrode plate 4 is 0.5mm, and the material is brass; the electrode plate 4 between the two piezoelectric sheets 3 is a positive electrode, and the electrode plate 4 between the rear cover plate 2 and the piezoelectric sheet 3 and the electrode plate between the piezoelectric sheet 3 and the front cover plate 1 are negative electrodes.
In order to further optimize the technical scheme, the rear cover plate 2 is made of No. 45 steel, and the inner diameter and the outer diameter of the rear cover plate 2 are equal to those of the piezoelectric patches 3; the length of the back cover plate 2 is 16.7 mm.
In order to further optimize the technical scheme, the front cover plate 1 is made of aluminum-magnesium alloy, and the front cover plate 1 is horn-shaped; the outer diameter of the front cover plate 1 facing one end of the electrode plate 4 is 20mm, the outer diameter is the same as that of the piezoelectric plate 3, and the diameter of the front cover plate 1 far away from one end of the electrode plate 4 is 26.6 mm; the length of the front cover plate 1 is 17.3 mm.
The piezoelectric sheet 3 often determines the power of the transducer, and in order to obtain a better deicing effect, PMNT piezoelectric ceramics are selected as the material of the piezoelectric sheet 3, the electromechanical coupling coefficient of the material is more than 0.7, and the piezoelectric coefficient, the electromechanical conversion efficiency and the strain quantity are great in advantages; for the transducer with larger radial size, the diameter of the piezoelectric ceramic element is set to be 1/4 smaller than the wavelength of sound wave, so that the longitudinal resonance frequency of the transducer can be prevented from being coupled with radial vibration of other components, the efficiency of the transducer is ensured, and the transducer is arranged according to a formula
To obtain lambdae75 mm. Therefore, the outer diameter of the piezoelectric sheet 3 is set to 20 mm. The inner diameter of which prevents the bolt 6 from being contacted to generate electricity conduction or frictionThe value of the piezoelectric plate is slightly larger than the diameter of the bolt 6 and is 8mm, and the thickness of the piezoelectric plate 3 is 5 mm.
The electrode plate 4 is made of brass with a thickness of 0.5mm in the structure, and is finely polished to serve as an electrode. Wherein, the brass between two piezoelectric sheets 3 is used as a positive electrode, and the brass between one piezoelectric sheet 3 and the back cover plate 2 and between the other piezoelectric sheet 3 and the front cover plate 1 is used as a negative electrode. The positive electrode is insulated from places which can be touched in the using process, so that the use is safer. Meanwhile, in order to improve the efficiency of the ultrasonic wave in the transmission process in the transducer as much as possible, except for adopting a connection mode that the bolt 6 applies pretightening force, epoxy resin glue is used for bonding between the electrode plate 4 and the piezoelectric plate 3, between the electrode plate 4 and the rear cover plate 2, between the electrode plate 4 and the front cover plate 1, so that the good bonding effect meets the use requirement of mechanical property, and the ultrasonic wave transmission performance is also excellent.
The back cover plate 2 acts to apply a force to the piezoelectric sheet 3 through the connection of the bolts 6, so there are some limitations on the selection of materials: the material with higher density is selected; in order to obtain higher electromechanical conversion efficiency, the smaller the mechanical loss in the material is, the better the mechanical loss is; the rear cover plate 2 of the transducer is under the action of alternating load for a long time, so that the mechanical fatigue strength of the material is required to be higher, and the situation that the strength fatigue failure is not generated in the life cycle of the material can be ensured; in addition, the structure of the back cover plate 2 should keep the contact surface with the wafer flat during the vibration process with high intensity, otherwise, the damage of the piezoelectric ceramic plate is easily caused. After the above conditions and economic considerations are combined, 45 steel, which has high rigidity and is easy to machine, is selected as the material of the rear cover plate 2. The back cover plate 2 is cylindrical, and the center of the back cover plate 2 is provided with a hole for the prestressed bolt to pass through, and the hole diameter is 8mm according to calculation. A circle of bosses are designed on the contact surface of the rear cover plate 2 and the prestressed bolt, and the bosses can improve the contact quality. The diameter of the end face of the back cover plate is 20mm, the diameter is the same as the outer diameter of the piezoelectric ceramic piece, and according to the equation:
the length of the back cover plate 2 can be calculated to be 16.7 mm.
The bolt 6 is the important part of transducer, and it plays and connects each part of transducer, exerts the effect of pretightning force, and the existence of bolt 6 can improve the stability and the reliability of transducer, guarantees the effectual transmission of vibration of transducer between each part to bolt 6 exerts the pretightning force to the transducer and makes each part of transducer all be in the compressive stress state, the effectual cracked destruction of preventing part. The thickness of the prestressed bolt determines the power of the transducer, so that, to ensure the mechanical strength of the transducer during vibration, the diameter of the cross-section of the bolt 6 should be between 1/4 and 1/3 of the transverse dimension of the transducer. In the present design, the diameter of the piezoceramic wafer is 20mm, and the diameter of the bolt 6 is 6mm in consideration of the simplicity of manufacturing, so 40Cr and M6 are selected for the bolt 6 and the nut.
In order to improve the vibration velocity ratio of the transducer, the aluminum-magnesium alloy which is light and high in sound velocity is selected as the material of the front cover plate 1. The appearance of front shroud 1 is the loudspeaker type, can adjust the directive property of transducer, opens threaded hole at the terminal surface with the contact of piezoelectric patch 3, and prestressing force bolt accessible this hole is connected with front shroud 1. The aluminum-magnesium alloy has good strength and hardness, and good heat conductivity, and is beneficial to heat dissipation of the transducer. The diameter of the small end face of the front cover plate 1 is 20mm, and is the same as the outer diameter of the piezoelectric ceramic piece according to the formula:
the large end face is obtained through optimized design, namely the diameter of the radiation end face is 26.6mm, and the total length is 17.3 mm.
The electrode sheet 4 has a main function of applying an electric field, but it also needs to have a function of dissipating heat. In the design, the electrode plate 4 between the piezoelectric ceramic plates is used as a positive electrode, and the electrode plate 4 between the piezoelectric plates and the front and rear cover plates is used as a negative electrode, which mainly takes the safety problem of electricity consumption into consideration, and the positive electrode plate is isolated from the part which can be touched by people. In consideration of economy, the electrode plate 4 is made of brass, and is used as an electrode after being finely ground, the electrode is annular, the inner and outer diameters of the electrode are the same as those of the piezoelectric ceramic wafer, the outer diameter is 20mm, the inner diameter is 8mm, and the thickness is 0.5 mm.
The working principle of the invention is as follows: the transducer is applied with a voltage through the electrode sheet 4, and vibration is generated by the inverse piezoelectric effect of the piezoelectric sheet 3, thereby generating ultrasonic waves.
Finite element simulations were performed on the designed sandwich piezoelectric transducer to verify that the designed transducer can remove ice from the backside of the panel. The plate ice model of the transducer of the present invention is necessarily simplified, and the simplified transducer and plate ice model are shown in fig. 4.
(1) Parameters of the material
The parameters of the PMNT piezoceramic material are as follows:
compliance coefficient matrix:
matrix of piezoelectric constants:
dielectric constant matrix:
density of PMNT ceramic: ρ 7.6 × 103kg/m3。
The dimensions of the aluminium panels and the ice layers used to simulate the skin of the aircraft were 300mm x 210mm x 2mm, and the material parameters are as given in table 1:
TABLE 1 aluminum sheet Properties on Ice coating Material
(2) Boundary condition
The mounting distance of the transducer on the plate can be determined by the formula, wherein d is 150mm, and the bottom end of the bolt 6 is bound with the metal plate by bonding. A voltage of 100V is applied to the middle interface of the two piezoelectric sheets 3, and a voltage of 0V is applied to the two ends of the two piezoelectric sheets. This means that when a spectrum analysis is performed, an alternating voltage is generated on the piezoelectric plate. The metal plate is used for simulating a riveting form of the aircraft skin in a four-side fixed support mode, and the metal plate refers to a plate simulating the aircraft skin.
(3) Computational analysis
The resonance analysis is performed on the whole deicing structure. In order to find the optimal deicing frequency, several points are randomly selected at the plate ice interface, and the XY shear stress and frequency relationship is output, as shown in FIG. 5. It can be easily derived from the figure that the optimal frequency for de-icing is 55.2kHz under excitation of the transducer.
The shear stress distribution at the plate ice interface at the optimum frequency of 55.2kHz excitation is shown in FIG. 6. From this experimental data, the shear strength between ice accretion and aluminium sheets of different roughness is in most cases between 0.794MPa and 9.620 MPa. In order to make the subject of the study more general, the shear strength between the skin aluminum plate and the ice accretion is considered to be about 0.3 MPa. As can be seen from the figure, the absolute values of most areas of the shear stress between the plate-ice interfaces are larger than 2MPa, and the maximum stresses of several randomly selected points in the figure 6 are respectively 3.158MPa, 4.730MPa, 1.470MPa and 5.377MPa, so that the transducer can remove ice on a given plate surface.
(4) Comparative analysis of Performance
The designed PMNT ultrasonic deicing transducer based on front-end and back-end vibration velocity optimization is compared with a PZT sandwich transducer. The PZT sandwich transducer is commonly used for ultrasonic cleaning at present, has simple manufacture and low cost and has excellent deicing performance. However, the transducer is heavy in structure and relatively large in volume, and can add large mass to the airplane if applied to actual airplane deicing. This would make its use in the aeronautical field considerably limited. According to the PMNT ultrasonic deicing transducer based on front and rear end vibration velocity optimization, the performance analysis result shows that the transducer can generate enough shear stress between plate ice interfaces, so that the aim of deicing can be well achieved. It can be seen from the block diagram that the transducer of the present invention is much smaller in volume than a PZT sandwich transducer, with a significant reduction in maximum height and maximum radius, and a concomitant reduction in weight, which is important for lightweight aircraft designs. The weight and size parameters of the two transducers are listed in table 2.
TABLE 2 comparison of structural parameters for PMNT piezoelectric transducers and PZT sandwich transducers
From the above comparison table, on the premise of achieving the deicing purpose as well, the designed PMNT ultrasonic deicing transducer based on front-back end vibration velocity optimization only has 28.1% of the weight of the PZT sandwich transducer, and the maximum height is less than 84%. The weight and the volume are greatly reduced, but the power required for deicing can be ensured. For the whole aircraft, the whole machine deicing needs to adopt a large number of transducers, so that the high power density transducer is necessary. The weight reduction effect of more than 70% of each transducer is of great significance for promoting the application of the ultrasonic deicing technology.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. A PMNT ultrasonic deicing transducer based on front and rear end vibration velocity optimization comprises a front cover plate (1) and a rear cover plate (2); the piezoelectric ceramic is characterized by further comprising two piezoelectric sheets (3) clamped between the front cover plate (1) and the rear cover plate (2); electrode plates (4) are padded between the front cover plate (1) and the piezoelectric sheets (3), between the two piezoelectric sheets (3) and between the rear cover plate (2) and the piezoelectric sheets (3); the rear cover plate (2), the piezoelectric sheet (3) and the electrode sheet (4) are all provided with through concentric round holes, one surface of the front cover plate (1) facing the electrode sheet (4) is provided with threaded holes corresponding to the concentric round holes, and the concentric round holes and the threaded holes are sequentially connected to form a connecting channel (5); and a bolt (6) enters the connecting channel (5) from the direction of the rear cover plate (2) and is in threaded connection with the threaded hole.
2. The PMNT ultrasonic deicing transducer optimized based on the front-to-back end vibration velocity according to claim 1, characterized in that the piezoelectric patch (3) is PMNT piezoelectric ceramic.
3. The PMNT ultrasonic deicing transducer optimized based on the front-end and back-end vibration velocity according to claim 1 or 2, characterized in that the two piezoelectric sheets (3) are equal in size, 5mm in thickness and 20mm in outer diameter.
4. The PMNT ultrasonic deicing transducer optimized based on the front-to-back end vibration velocity according to claim 1, characterized in that the concentric circular hole inner wall on the back cover plate (2) has threads adapted to the bolts (6).
5. The PMNT ultrasonic deicing transducer optimized based on the front-end and back-end vibration velocity according to claim 4, characterized in that the bolt (6) is of M6 specification, the diameter of the bolt (6) is 6mm, and the material is 40 Cr.
6. The PMNT ultrasonic deicing transducer optimized based on the front-end and back-end vibration velocity according to claim 5, characterized in that the inner diameters of the concentric circular holes on the piezoelectric sheet (3) and the electrode sheet (4) are 8 mm.
7. The PMNT ultrasonic deicing transducer optimized based on the front-end and back-end vibration velocity according to claim 1, characterized in that the bonding between the back cover plate (2) and the electrode sheet (4), between the electrode sheet (4) and the piezoelectric sheet (3), and between the electrode sheet (4) and the front cover plate (1) is performed by epoxy resin glue.
8. The PMNT ultrasonic deicing transducer optimized based on the front-end and rear-end vibration velocities according to claim 1, characterized in that the electrode sheet (4) has a thickness of 0.5mm and is made of brass; the electrode plate (4) between the two piezoelectric sheets (3) is a positive electrode, and the electrode plate (4) between the rear cover plate (2) and the piezoelectric sheets (3) and the electrode plate between the piezoelectric sheets (3) and the front cover plate (1) are negative electrodes.
9. The PMNT ultrasonic deicing transducer optimized based on the front-end and rear-end vibration velocity according to claim 1, characterized in that the material of the back cover plate (2) is 45 steel, and the inner diameter and the outer diameter of the back cover plate (2) are equal to those of the piezoelectric sheets (3); the length of the rear cover plate (2) is 16.7 mm.
10. The PMNT ultrasonic deicing transducer optimized based on the front-end and rear-end vibration velocity according to claim 1, characterized in that the material of the front cover plate (1) is aluminum-magnesium alloy, and the shape of the front cover plate (1) is horn-shaped; the outer diameter of one end, facing the electrode plate (4), of the front cover plate (1) is 20mm and is the same as that of the piezoelectric plate (3), and the diameter of one end, far away from the electrode plate (4), of the front cover plate (1) is 26.6 mm; the length of the front cover plate (1) is 17.3 mm.
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