Preparation method of sandwich type piezoelectric transducer immersed in ultrahigh pressure liquid

Abstract

The invention discloses a preparation method of a sandwich type piezoelectric transducer immersed in an ultrahigh-pressure liquid in order to endow the sandwich type piezoelectric transducer with the capability of working in the ultrahigh-pressure liquid. The front end cover, the piezoelectric ceramic piece set, the rear end cover and the pre-tightening bolt form a sandwich type piezoelectric transducer, and the pre-tightening bolt is screwed in to enable the front end cover and the rear end cover to clamp the piezoelectric ceramic piece set. The bonding glue is used for bonding the interface of the front end cover, the piezoelectric ceramic piece group and the rear end cover, the pouring glue is used for filling a cavity in the sandwich type piezoelectric transducer, and the glue is coated to realize electrical insulation between the sandwich type piezoelectric transducer and external liquid. Bubbles remaining in the adhesive glue and the potting glue are discharged in a vacuumizing mode, and the texture is soft after the coated glue is vulcanized. By means of the method, the structural compactness of the sandwich type piezoelectric transducer is improved, it is guaranteed that the sandwich type piezoelectric transducer cannot be subjected to structural damage in ultrahigh-pressure liquid, and a technical basis is provided for developing piezoelectric sensors and actuators oriented to the ultrahigh-pressure liquid.

Description

Technical Field

[0001] The invention relates to a method for preparing a sandwich-type piezoelectric transducer immersed in ultra-high pressure liquid, and belongs to the technical field of piezoelectric transducers. Background Art

[0002] Deep-sea exploration, search for extraterrestrial life, and food preservation and processing all have high hydrostatic pressure working environments. The deepest point in the ocean that has been explored so far is the Mariana Trench, where the surrounding seawater pressure can reach 110 MPa. Overcoming high hydrostatic pressure is the primary challenge in developing 10,000-meter-class deep-sea exploration and resident equipment. In the solar system, there is a "deep-sea" planet filled with liquid water - Europa, with a radius of about 1,560 km and a surface gravity acceleration of about 1.3 m / s 2 If calculated based on the deepest depth of 80 km in the ocean, the pressure is about 104 MPa, which is equivalent to the deep sea pressure 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 fruit and vegetable products, 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] The sandwich piezoelectric transducer can realize the mutual conversion between force and electricity, and is the core component of piezoelectric sensing and driving technology. However, the existing sandwich piezoelectric transducer is difficult to cope with the ultra-high pressure of liquid. Because there is a cavity inside the existing sandwich piezoelectric transducer, its structure is easily damaged in ultra-high pressure liquid. Eliminating the internal cavity of the existing sandwich piezoelectric transducer is an effective way to solve the above problem. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for preparing a sandwich piezoelectric transducer immersed in ultra-high pressure liquid in view of the defects involved in the background technology.

[0005] The present invention adopts the following technical solutions to solve the above technical problems: A method for preparing a sandwich piezoelectric transducer immersed in ultra-high 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, and adjacent piezoelectric ceramic sheets are separated by the electrode sheets; the front end cover and the rear end cover are respectively provided with a threaded blind hole and a stepped hole, and a through hole is provided in the middle of the piezoelectric ceramic sheet group; the pre-tightening bolt passes through the stepped hole of the rear end cover and the through hole of the piezoelectric ceramic sheet group in sequence, and cooperates with the threaded blind hole of the front end cover; Characterized in that the preparation method comprises the following steps: Step S1), using a cleaning device, clean the front cover, rear cover, pre-tightening bolts, piezoelectric ceramic sheet and electrode sheet; Step S2), bonding the front end cover, the rear end cover, the piezoelectric ceramic sheet and the interface of the electrode sheet with bonding glue; Step S3), pouring potting glue from the rear end cover until filling 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; Step S4), using a vacuum device to extract the bubbles remaining in the potting glue; Step S5), slowly screwing in the pre-tightening bolt; Step S6), raising the temperature to solidify the bonding glue and the potting glue; Step S7), welding wires onto the electrode sheets, and coating the piezoelectric ceramic sheet group and the electrode sheets with insulating glue; As a further optimization scheme 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 cleaning machine; As a further optimization scheme of the method for preparing a sandwich piezoelectric transducer immersed in ultra-high pressure liquid of the present invention, the bonding glue in step S2) is epoxy resin; As a further optimization scheme of the method for preparing a sandwich piezoelectric transducer immersed in ultra-high pressure liquid of the present invention, the elastic modulus of the potting glue in the solid state described in step S2) is greater than 1 GPa; As a further optimization scheme of the preparation method of the sandwich piezoelectric transducer immersed in ultra-high pressure liquid of the present invention, the vacuum pumping equipment in step S4) is a vacuum defoaming barrel; As a further optimization scheme of the method for preparing a sandwich piezoelectric transducer immersed in ultra-high pressure liquid of the present invention, the pre-tightening bolts in step S5) are 12.9 grade galvanized high-strength bolts; As a further optimization scheme of the method for preparing a sandwich piezoelectric transducer immersed in ultra-high pressure liquid of the present invention, the temperature in step S6) is 60-100° C.; As a further optimization scheme of the method for preparing a sandwich piezoelectric transducer immersed in ultra-high pressure liquid of the present invention, the insulating coating glue in step S7) is vulcanized glue; Compared with the prior art, the present invention adopts the above technical solution and has the following technical effects: 1. The internal cavity of the sandwich piezoelectric transducer is filled with glue, which improves its structural density and enables the sandwich piezoelectric transducer to work in ultra-high pressure liquid; 2. Applying insulating glue realizes electrical isolation between the sandwich piezoelectric transducer and the liquid medium, avoiding the occurrence of circuit short circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 Cross-section of a sandwich piezoelectric transducer and its internal cavity distribution Figure 2 Preparation method and steps of sandwich piezoelectric transducer immersed in ultra-high pressure liquid Figure 3 Cross-section of a sandwich piezoelectric transducer that can be immersed in ultra-high pressure liquids 1: front cover; 2: piezoelectric ceramic sheet group; 3: rear cover; 4: bolts; 5-1: anhydrous ethanol or acetone; 5-2: ultrasonic cleaning machine; 5-3: bonding glue; 5-4: potting glue; 5-5: vacuum barrel; 5-6: wrench; 5-7: insulation box or drying box; 5-8: insulation glue; 5-9: scraper; DETAILED DESCRIPTION

[0007] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings: The present invention can be implemented in many different forms and should not be considered to be limited to the embodiments described herein. On the contrary, these embodiments are provided to make this disclosure thorough and complete, and will fully express the scope of the present invention to those skilled in the art. In the accompanying drawings, components are enlarged for clarity.

[0008] The present invention discloses a method for preparing a sandwich piezoelectric transducer immersed in ultra-high pressure liquid. The sandwich piezoelectric transducer comprises 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, and adjacent piezoelectric ceramic sheets are separated by the electrode sheets. The front end cover and the rear end cover are respectively provided with a threaded blind hole and a stepped hole, and a through hole is provided in the middle of the piezoelectric ceramic sheet group. The pre-tightening bolt passes through the stepped hole of the rear end cover and the through hole of the piezoelectric ceramic sheet group in sequence, and cooperates with the threaded blind hole of the front end cover, such as Figure 1 As shown; like Figure 2 As shown, the preparation method comprises the following steps: Step S1), using a cleaning device, clean the front cover, rear cover, pre-tightening bolts, piezoelectric ceramic sheets and electrode sheets; Step S2), bonding the front cover, the rear cover, the piezoelectric ceramic sheet and the interface of the electrode sheet with adhesive glue; Step S3), pouring potting glue from the rear end cover until filling 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; Step S4), using a vacuum device to extract the bubbles remaining in the potting glue; Step S5), slowly screw in the pre-tightening bolt; Step S6), raising the temperature to solidify the bonding glue and the potting glue; Step S7), welding wires onto the electrode sheets, and coating the piezoelectric ceramic sheet group and the electrode sheets with insulating glue; The sandwich piezoelectric transducer prepared by this method is as follows Figure 3 As shown; The present invention also discloses a further optimization scheme for the preparation method of a sandwich piezoelectric transducer immersed in ultra-high pressure liquid: In step S1), the cleaning solution is anhydrous ethanol or acetone, and the cleaning equipment is an ultrasonic cleaning machine; The bonding glue in step S2) is epoxy resin; The elastic modulus of the potting glue in step S2) in a solid state is greater than 1 GPa; The vacuuming equipment in step S4) is a vacuum defoaming barrel; The pre-tightening bolts in step S5) are 12.9 grade galvanized high-strength bolts; The temperature in step S6) is 60-100°C; The insulating coating glue in step S7) is vulcanized glue; It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0009] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method 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 in the scope of protection of the present invention.

Claims

1. A method for preparing a sandwich piezoelectric transducer immersed in ultra-high 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, and adjacent piezoelectric ceramic sheets are separated by the electrode sheets; the front end cover and the rear end cover are respectively provided with a threaded blind hole and a stepped hole, and a through hole is provided in the middle of the piezoelectric ceramic sheet group; the pre-tightening bolt passes through the stepped hole of the rear end cover and the through hole of the piezoelectric ceramic sheet group in sequence, and cooperates with the threaded blind hole of the front end cover; It is characterized in that The preparation method comprises the following steps: Step S1), using a cleaning device, clean the front cover, rear cover, pre-tightening bolts, piezoelectric ceramic sheet and electrode sheet; Step S2), bonding the front end cover, the rear end cover, the piezoelectric ceramic sheet and the interface of the electrode sheet with bonding glue; Step S3), pouring potting glue from the rear end cover until filling 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; Step S4), using a vacuum device to extract the bubbles remaining in the potting glue; Step S5), slowly screwing in the pre-tightening bolt; Step S6), raising the temperature to solidify the bonding glue and the potting glue; Step S7), welding wires onto the electrode sheets, and coating the piezoelectric ceramic sheet group and the electrode sheets with insulating glue.

2. The method for preparing a sandwich piezoelectric transducer immersed in ultra-high pressure liquid according to claim 1, characterized in that: In step S1), the cleaning solution is anhydrous ethanol or acetone, and the cleaning equipment is an ultrasonic cleaning machine.

3. The method for preparing a sandwich piezoelectric transducer immersed in ultra-high pressure liquid according to claim 1, characterized in that: The bonding glue in step S2) is epoxy resin.

4. The method for preparing a sandwich piezoelectric transducer immersed in ultra-high pressure liquid according to claim 1, characterized in that: The elastic modulus of the potting glue in step S2) in a solid state is greater than 1 GPa.

5. The method for preparing a sandwich piezoelectric transducer immersed in ultra-high pressure liquid according to claim 1, characterized in that: The vacuum equipment in step S4) is a vacuum defoaming barrel.

6. The method for preparing a sandwich piezoelectric transducer immersed in ultra-high pressure liquid according to claim 1, characterized in that: The pre-tightening bolts in step S5) are 12.9 grade galvanized high-strength bolts.

7. The method for preparing a sandwich piezoelectric transducer immersed in ultra-high pressure liquid according to claim 1, characterized in that: The temperature in step S6) is 60-100°C.

8. The method for preparing a sandwich piezoelectric transducer immersed in ultra-high pressure liquid according to claim 1, characterized in that: The insulating coating glue in step S7) is vulcanized glue.

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