A method of making a sandwich piezoelectric transducer immersed in an ultrahigh pressure liquid

Abstract

In order to endow the sandwich piezoelectric transducer with the ability of working in superhigh pressure liquid, a preparation method of the sandwich piezoelectric transducer immersed in superhigh pressure liquid is disclosed. The front end cover, the piezoelectric ceramic sheet group, the rear end cover and the pre-tightening bolt constitute the sandwich piezoelectric transducer, and the rotation of the pre-tightening bolt makes the front end cover and the rear end cover clamp the piezoelectric ceramic sheet group. The adhesive glue bonds the interfaces of the front end cover, the piezoelectric ceramic sheet group and the rear end cover, the filling glue fills the cavity inside the sandwich piezoelectric transducer, and the coating glue realizes the electrical insulation between the sandwich piezoelectric transducer and the external liquid. The bubbles remaining in the adhesive glue and the filling glue are discharged by vacuumizing, and the coating glue is soft after vulcanization. The method improves the structural compactness of the sandwich piezoelectric transducer, guarantees that the sandwich piezoelectric transducer will not be structurally damaged in superhigh pressure liquid, and provides a technical basis for developing piezoelectric sensors and actuators facing superhigh pressure liquid.

Description

Technical Field

[0001] This invention relates to a method for preparing a sandwich-type piezoelectric transducer immersed in an ultra-high pressure liquid, belonging to the field of piezoelectric transducer technology. Background Technology

[0002] High hydrostatic pressure environments exist in fields such as deep-sea exploration, the search for extraterrestrial life, and food preservation and processing. The deepest point currently known in the ocean is the Mariana Trench, where the surrounding seawater pressure can reach 110 MPa. Overcoming this high hydrostatic pressure is the primary challenge in developing equipment for deep-sea exploration and habitation at depths of tens of thousands of meters. Within the solar system, there exists a "deep-sea" planet filled with liquid water—Europa, with a radius of approximately 1560 km and a surface gravitational acceleration of about 1.3 m / s². 2 If calculated based on its deepest point of 80 km in the ocean, its pressure is approximately 104 MPa, which is equivalent to the pressure at a depth of 10,000 meters in the Mariana Trench on Earth. Ultra-high hydrostatic pressure sterilization, as a typical non-thermal sterilization technology, has the advantages of good sterilization effect and good preservation of original flavor. It is often used in the processing of fruits, vegetables, meat products and other foods. The sterilization working pressure is generally between 100 and 600 MPa, and sometimes the sterilization working pressure can reach up to 1000 MPa.

[0003] Sandwich piezoelectric transducers, capable of converting between force and electricity, are core components of piezoelectric sensing and actuation technology. However, existing sandwich piezoelectric transducers struggle to withstand the extremely high pressures of liquids. This is because existing sandwich piezoelectric transducers contain internal cavities, making their structure susceptible to damage in ultra-high-pressure liquids. Eliminating the internal cavity in existing sandwich piezoelectric transducers is an effective way to solve this problem. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to address the deficiencies mentioned in the background art by providing a method for preparing a sandwich piezoelectric transducer immersed in an ultra-high pressure liquid.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A method for preparing a sandwich piezoelectric transducer immersed in an ultra-high pressure liquid, the sandwich piezoelectric transducer comprising a front end cover, a piezoelectric ceramic sheet assembly, a rear end cover, and a preload bolt; the piezoelectric ceramic sheet assembly consists of a plurality of piezoelectric ceramic sheets and a plurality of electrode sheets, adjacent piezoelectric ceramic sheets being separated by the electrode sheets; the front end cover and the rear end cover are respectively provided with threaded blind holes and stepped holes, and the piezoelectric ceramic sheet assembly has a through hole in the middle; the preload bolt passes sequentially through the stepped hole of the rear end cover and the through hole of the piezoelectric ceramic sheet assembly, and engages with the threaded blind hole of the front end cover;

[0007] The preparation method is characterized by comprising the following steps:

[0008] Step S1) Clean the front cover, rear cover, pre-tightening bolts, piezoelectric ceramic sheet and electrode sheet with the help of cleaning equipment;

[0009] Step S2), use adhesive to bond the interfaces of the front end cover, rear end cover, piezoelectric ceramic sheet and electrode sheet together;

[0010] Step S3), potting adhesive is poured in from the rear end cap until the threaded blind hole of the front end cap, the through hole of the piezoelectric ceramic sheet assembly and the stepped hole of the rear end cap are filled;

[0011] Step S4) Use a vacuum pump to remove any remaining air bubbles from the potting adhesive;

[0012] Step S5), slowly screw in the pre-tightening bolt;

[0013] Step S6), increase the temperature to cure the adhesive and the potting compound;

[0014] Step S7): Weld wires onto the electrode sheet, and coat the piezoelectric ceramic sheet assembly and the electrode sheet with insulating adhesive;

[0015] As a further optimization of the preparation method of the sandwich piezoelectric transducer immersed in ultra-high pressure liquid of the present invention, the cleaning solution in step S1) is anhydrous ethanol or acetone, and the cleaning equipment is an ultrasonic cleaner.

[0016] As a further optimization of the preparation method of the sandwich piezoelectric transducer immersed in ultra-high pressure liquid of the present invention, the adhesive in step S2) is epoxy resin.

[0017] As a further optimization of the preparation method of the sandwich piezoelectric transducer immersed in ultra-high pressure liquid of the present invention, the potting adhesive mentioned in step S2) has an elastic modulus greater than 1 GPa in the solid state.

[0018] As a further optimization of the preparation method of the sandwich piezoelectric transducer immersed in ultra-high pressure liquid of the present invention, the vacuuming equipment mentioned in step S4) is a vacuum defoaming tank.

[0019] As a further optimization of the preparation method of the sandwich piezoelectric transducer immersed in ultra-high pressure liquid of the present invention, the pre-tightening bolt in step S5) is a 12.9 grade galvanized high-strength bolt;

[0020] As a further optimization of the preparation method of the sandwich piezoelectric transducer immersed in ultra-high pressure liquid of the present invention, the temperature in step S6) is 60~100℃;

[0021] As a further optimization of the preparation method of the sandwich piezoelectric transducer immersed in ultra-high pressure liquid of the present invention, the insulating coating adhesive mentioned in step S7) is a vulcanized adhesive.

[0022] Compared with the prior art, the present invention, employing the above technical solution, has the following technical effects:

[0023] 1. The internal cavity of the sandwich piezoelectric transducer is filled with glue, which improves its structural density and gives the sandwich piezoelectric transducer the ability to work when immersed in ultra-high pressure liquid.

[0024] 2. Applying insulating adhesive achieves electrical isolation between the sandwich piezoelectric transducer and the liquid medium, preventing short circuits. Attached Figure Description

[0025] Figure 1 Cross-sectional view and internal cavity distribution of sandwich piezoelectric transducer

[0026] Figure 2 Preparation steps of sandwich piezoelectric transducers immersed in ultra-high pressure liquid

[0027] Figure 3 Cross-sectional view of a sandwich piezoelectric transducer that can be immersed in ultra-high pressure liquid.

[0028] 1: Front cover; 2: Piezoelectric ceramic sheet assembly; 3: Rear cover; 4: Bolt; 5-1: Anhydrous ethanol or acetone; 5-2: Ultrasonic cleaner; 5-3: Adhesive; 5-4: Potting compound; 5-5: Vacuum chamber; 5-6: Wrench; 5-7: Insulation box or drying oven; 5-8: Insulating adhesive; 5-9: Scraper; Detailed Implementation

[0029] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings:

[0030] This invention can be implemented in many different forms and should not be considered limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully express the scope of the invention to those skilled in the art. In the drawings, components are enlarged for clarity.

[0031] This invention discloses a method for preparing a sandwich-type piezoelectric transducer immersed in an ultra-high pressure liquid. The sandwich-type piezoelectric transducer includes a front end cover, a piezoelectric ceramic sheet assembly, a rear end cover, and a preload bolt. The piezoelectric ceramic sheet assembly consists of several piezoelectric ceramic sheets and several electrode sheets, with adjacent piezoelectric ceramic sheets separated by the electrode sheets. The front end cover and the rear end cover are respectively provided with threaded blind holes and stepped holes, and the piezoelectric ceramic sheet assembly has a through hole in the middle. The preload bolt passes sequentially through the stepped hole of the rear end cover and the through hole of the piezoelectric ceramic sheet assembly, and engages with the threaded blind hole of the front end cover. Figure 1As shown;

[0032] like Figure 2 As shown, the preparation method includes the following steps:

[0033] Step S1): Clean the front cover, rear cover, pre-tightening bolts, piezoelectric ceramic sheet and electrode sheet using cleaning equipment.

[0034] Step S2), use adhesive to bond the interfaces of the front cover, rear cover, piezoelectric ceramic sheet and electrode sheet together;

[0035] Step S3), potting adhesive is poured in from the rear end cap until it fills the threaded blind hole of the front end cap, the through hole of the piezoelectric ceramic sheet assembly and the stepped hole of the rear end cap.

[0036] Step S4) Use a vacuum pump to remove any remaining air bubbles from the potting adhesive;

[0037] Step S5), slowly screw in the pre-tightening bolt;

[0038] Step S6), increase the temperature to cure the adhesive and the potting compound;

[0039] Step S7): Solder wires onto the electrode sheet, and coat the piezoelectric ceramic sheet assembly and electrode sheet with insulating adhesive;

[0040] The sandwich piezoelectric transducer prepared by this method is as follows: Figure 3 As shown;

[0041] This invention also discloses a further optimized method for fabricating a sandwich piezoelectric transducer immersed in an ultra-high pressure liquid:

[0042] In step S1), the cleaning solution is anhydrous ethanol or acetone, and the cleaning equipment is an ultrasonic cleaner.

[0043] The adhesive used in step S2) is epoxy resin;

[0044] The potting adhesive described in step S2) has an elastic modulus greater than 1 GPa in the solid state;

[0045] The vacuuming device mentioned in step S4) is a vacuum defoaming tank;

[0046] The pre-tightening bolt mentioned in step S5) is a 12.9 grade galvanized high-strength bolt;

[0047] The temperature mentioned in step S6) is 60~100℃;

[0048] The insulating coating adhesive mentioned in step S7) is a vulcanized adhesive;

[0049] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein.

[0050] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a sandwich piezoelectric transducer immersed in an ultrahigh pressure liquid, the sandwich piezoelectric transducer comprising a front end cover, a piezoelectric ceramic sheet group, a rear end cover and a pre-tightening bolt; the piezoelectric ceramic sheet group is composed of a plurality of piezoelectric ceramic sheets and a plurality of electrode sheets, adjacent piezoelectric ceramic sheets are separated by electrode sheets; the front end cover and the rear end cover are respectively provided with a threaded blind hole and a stepped hole, and the piezoelectric ceramic sheet group is provided with a through hole; the pre-tightening bolt passes through the stepped hole of the rear end cover, the through hole of the piezoelectric ceramic sheet group and the threaded blind hole of the front end cover in sequence; the method comprises the following steps: S1) cleaning the front end cover, the rear end cover, the pre-tightening bolt, the piezoelectric ceramic sheets and the electrode sheets by means of a cleaning device; S2) bonding the interfaces of the front end cover, the rear end cover, the piezoelectric ceramic sheets and the electrode sheets with adhesive; S3) filling the adhesive from the rear end cover until the threaded blind hole of the front end cover, the through hole of the piezoelectric ceramic sheet group and the stepped hole of the rear end cover are filled; S4) extracting the air bubbles remaining in the adhesive by means of a vacuum extraction device; S5) slowly rotating the pre-tightening bolt; S6) increasing the temperature to solidify the adhesive and the adhesive; S7) welding wires on the electrode sheets, and coating the exposed surfaces of the piezoelectric ceramic sheet group and the electrode sheets with insulating adhesive, the insulating adhesive being adhesive for electrical isolation. characterized in that The cleaning solution in step S1) is anhydrous ethanol or acetone, and the cleaning device is an ultrasonic cleaning machine. The adhesive in step S2) is epoxy resin. The elastic modulus of the adhesive in a solid state in step S2) is greater than 1 GPa. The vacuum extraction device in step S4) is a vacuum defoaming barrel. The pre-tightening bolt in step S5) is a 12.9 grade galvanized high-strength bolt. The temperature in step S6) is 60-100℃. ​ ​ 2. A method of making a sandwich piezoelectric transducer immersed in an ultra-high pressure liquid according to claim 1, characterized in that, ​ 3. A method of making a sandwich piezoelectric transducer immersed in a superhigh pressure liquid according to claim 1, characterized in that, ​ 4. A method of making a sandwich piezoelectric transducer immersed in an ultra-high pressure liquid according to claim 1, characterized in that, ​ 5. The method of claim 1, wherein the method further comprises: ​ 6. A method of making a sandwich piezoelectric transducer immersed in an ultra-high pressure liquid according to claim 1, characterized in that, ​ 7. A method of making a sandwich piezoelectric transducer immersed in an ultra-high pressure liquid according to claim 1, characterized in that, ​

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