CN218885035U

CN218885035U - Ultrasonic sensor

Info

Publication number: CN218885035U
Application number: CN202223382576.8U
Authority: CN
Inventors: 刘军波; 陈福庆
Original assignee: Weihai Boyang Electronic Technology Co ltd
Current assignee: Weihai Boyang Electronic Technology Co ltd
Priority date: 2022-12-16
Filing date: 2022-12-16
Publication date: 2023-04-18
Anticipated expiration: 2032-12-16

Abstract

The utility model relates to an ultrasonic sensor belongs to the ultrasonic sensor field. The ceramic electronic ceramic is characterized by comprising a shell, wherein the shell is made of electronic ceramic materials and is integrally formed. The casing is a cylindrical structure with the lower end closed and the upper end opened, a glaze firing layer is arranged on the outer surface of the casing, a positioning column is axially arranged on the inner wall of the casing, a matching layer, a piezoelectric ceramic piece, a back lining layer and a potting layer are sequentially arranged in a cavity of the casing from bottom to top, a signal cable penetrates through the potting layer and the back lining layer and is welded on the anode and the cathode of the piezoelectric ceramic piece, and an annular gap is formed between the inner wall of the casing and the outer edge of the piezoelectric ceramic piece. The utility model has the advantages that: the integrated forming design is adopted, no sealing element is arranged, the structure is compact, the structure is firm and durable, the production cost is reduced, the production efficiency is improved, and the integrated forming device is suitable for large-scale production.

Description

Ultrasonic sensor

Technical Field

The utility model relates to an ultrasonic sensor field says in detail to a high pressure resistant corrosion resistant ultrasonic sensor for measure the fluid flow in the closed conduit.

Background

As is well known, the ultrasonic sensors are core components of ultrasonic water meters, ultrasonic heat meters and ultrasonic flowmeters, mutual conversion between electric signals and ultrasonic signals is realized, a time difference working principle is adopted, the two ultrasonic sensors are respectively installed at the upstream and the downstream of a measured fluid and transmit and receive the ultrasonic signals in turn, and a signal processing unit calculates the flow of the fluid by measuring the difference value of forward flow propagation time and backward flow propagation time of the ultrasonic signals.

The ultrasonic sensor in the prior art generally comprises a shell, a protective membrane, a piezoelectric ceramic piece and a sealing piece, wherein the shell and the protective membrane are made of stainless steel or engineering plastics, the shell and the protective membrane are assembled together through the sealing piece to form a closed space, the closed space is isolated from a measured fluid and bears external pressure to protect the internal piezoelectric ceramic piece, the protective membrane also plays a role of a sound wedge to transmit ultrasonic signals, and the sealing piece generally adopts a special adhesive.

The ultrasonic sensor of this structure has the following problems: in order to better transmit ultrasonic signals and protect the membrane from reducing the thickness as much as possible, the thickness of a common stainless steel thin plate is only 0.06 millimeter, and the compression strength is low; the components of the measured fluid are complex, the measured fluid has certain corrosivity, the corrosion resistance of stainless steel materials to acid, alkali and salt is low, the sensor is easy to rust and corrode to cause leakage, and the sensor cannot work stably for a long time; the surface of the sensor is rough, so that scaling is easy to occur, and the intensity and quality of ultrasonic signals are reduced; the sealing element adopts a special adhesive, the application range is limited, and the sealing element is easy to age and lose effectiveness under the repeated change impact of temperature and pressure; the axial length of the sensor is short, a deep sunken area is formed between the front end of the sensor and the pipe wall, sediment and dirt are easy to deposit, and ultrasonic signal transmission is blocked, so that the sensor fails; the sensor is assembled by a plurality of parts such as a shell, a protective membrane, a sealing element and the like, so that the sensor is complex in structure, high in production cost and low in production efficiency.

Disclosure of Invention

In order to overcome the not enough of prior art, the utility model provides an ultrasonic sensor can use under high temperature high pressure environment for a long time, and the ability of acidproof, alkali, salt erosion is strong, and measurement accuracy is high.

The utility model provides a technical scheme that its technical problem adopted is: an ultrasonic sensor is provided with a casing, which is characterized in that: the casing is a cylindrical structure with the lower end closed and the upper end opened, a glaze firing layer is arranged on the outer surface of the casing, a positioning column is axially arranged on the inner wall of the casing, a matching layer, a piezoelectric ceramic piece, a back lining layer and a potting layer are sequentially arranged in a cavity of the casing from bottom to top, and a signal cable penetrates through the potting layer and the back lining layer and is welded on the positive electrode and the negative electrode of the piezoelectric ceramic piece.

The cavity of the shell is of a cylindrical structure.

The piezoelectric ceramic plate is positioned in the center of the shell.

The number of the positioning columns is at least three, and the positioning columns are uniformly distributed on the inner wall of the shell.

An annular gap is formed between the inner wall of the shell and the outer edge of the piezoelectric ceramic piece.

The shell is made of electronic ceramic materials and is integrally formed.

The utility model has the advantages that: the integrated forming design is adopted, no sealing element is arranged, the structure is compact, the structure is firm and durable, the production cost is reduced, the production efficiency is improved, and the integrated forming device is suitable for large-scale production.

Drawings

The present invention will be further explained with reference to the drawings and examples.

Fig. 1 is an external view of the present invention.

Fig. 2 is a longitudinal sectional view of the present invention.

Fig. 3 isbase:Sub>A top view of the present invention.

Fig. 4 is a schematic view of the installation of the pipeline of the present invention.

In the figure: 1. the piezoelectric ceramic chip comprises a glaze firing layer, a shell, a matching layer, a piezoelectric ceramic chip, a backing layer, a potting layer, a positioning column, a signal cable, an annular gap, a positive electrode and a negative electrode, wherein the glaze firing layer comprises 2, the shell comprises 3, the matching layer comprises 4, the piezoelectric ceramic chip comprises 5, the backing layer comprises 6, the potting layer comprises 7, the positioning column comprises 8, the signal cable comprises 9, the annular gap comprises 10, and the positive electrode and the negative electrode comprise 11.

Detailed Description

The utility model discloses a: the ceramic piezoelectric ceramic package comprises a shell 2, a glaze firing layer 1, a matching layer 3, a piezoelectric ceramic piece 4, a back lining layer 5, an encapsulating layer 6, a positioning column 7 and a signal cable 8. The shell 2 is used as the main structure of the sensor, plays a role in sealing and protecting the piezoelectric ceramic piece 4 inside, is isolated from the measured fluid, and bears external high temperature and high pressure. The appearance of the shell 2 is cylindrical with the lower end closed and the upper end open, the glaze firing layer 1 is arranged on the outer surface of the shell 2, four positioning columns 7 are uniformly arranged on the inner wall of the shell 2 along the axial direction, a cylindrical cavity is arranged inside the shell 2, the matching layer 3, the piezoelectric ceramic piece 4, the back lining layer 5 and the encapsulating layer 6 are sequentially arranged from bottom to top in the cylindrical cavity, and the signal cable 8 penetrates through the encapsulating layer 6 and the back lining layer 5 to be welded on the anode 10 and the cathode 11 of the piezoelectric ceramic piece 4.

Foretell ultrasonic sensor, casing 2 adopt electronic ceramic material to fire, integrated into one piece, and no sealing member need not machine tooling, and is with low costs, and waterproof leakproofness is good, has higher mechanical strength and chemical stability, can use under high temperature high pressure environment for a long time, avoids arousing the sensor damage because of the ageing inefficacy of sealing member. The bottom of the shell 2 also plays a role of a sound wedge to transmit ultrasonic signals, and the shell 2 is fired by electronic ceramic materials, so that the sound conduction rate is high, and the attenuation of the ultrasonic signals is small and is not distorted.

According to the ultrasonic sensor, the outer surface of the shell 2 is provided with the colorless vitreous glaze layer 1, so that the mechanical strength, the electrical insulation property, the thermal stability and the chemical stability of the product are improved, the product is densified, the surface is smooth and clean, the water absorption is low, the acid, alkali and salt corrosion resistance is enhanced, and scaling is not easy to occur.

Foretell ultrasonic sensor, reference column 7 evenly distributed are on 2 inner walls of casing, and reference column 7 is three at least, and 2 inner walls of preferred casing evenly set up four reference columns 7, improve the high pressure resistant ability of sensor, guarantee that piezoceramics piece 4 fixes a position at 2 centers of casing, reach best resonance effect, improve transmitted signal intensity and received signal sensitivity, are favorable to improving measurement accuracy.

According to the ultrasonic sensor, due to the isolation of the positioning column 7, the annular gap 9 is formed between the inner wall of the shell 2 and the outer edge of the piezoelectric ceramic piece 4, so that when the piezoelectric ceramic piece 4 is pasted, air and redundant viscose can be discharged, the thickness of the matching layer 3 is uniform, and the signal quality and the yield of the sensor are improved.

The axial length of the shell 2 of the ultrasonic sensor is large, after the ultrasonic sensor is installed on a pipeline, the front end of the sensor penetrates through the pipe wall to enter the pipeline, a depressed area is not formed, ultrasonic signal transmission is prevented from being blocked due to sediment and dirt deposition, and long-term stable and reliable operation of an instrument is guaranteed.

In the ultrasonic sensor, the matching layer 3 is arranged at the bottom of the inner cavity of the shell 2, and the piezoelectric ceramic piece 4 is fixed, so that acoustic matching between the sensor and fluid is realized; the diameter of the piezoelectric ceramic piece 4 is 14mm, the thickness is 2mm, the frequency is 1MHz, and single-side welding is adopted, so that wiring is convenient; a back lining layer 5 is arranged above the piezoelectric ceramic plate 4, so that the ultrasonic signal intensity in the fluid direction is improved; a potting layer 6 is arranged above the back lining layer 5, the residual space of the inner cavity of the shell 2 is filled with epoxy potting adhesive, and a signal cable 8 is fixed to play a role in sealing and protecting the internal components of the sensor; the signal cable 8 adopts a two-wire shielding cable, penetrates through the potting layer 6 and the backing layer 5, is welded on the anode 10 and the cathode 11 of the piezoelectric ceramic sheet 4, and is used for transmitting electric signals.

The shell of the utility model is integrally formed by firing electronic ceramic materials, has no sealing element, does not need machining, has low cost and good waterproof sealing performance, and can be used in high-temperature and high-pressure environment for a long time; the bottom of the shell is used as an acoustic wedge, the sound conduction rate is high, and the attenuation of ultrasonic signals is reduced; the glaze layer is fired, so that the densified surface of the product is smooth and clean, the corrosion resistance is high, and scaling is not easy to occur; the positioning column ensures that the piezoelectric ceramic piece is positioned in the center of the shell, the optimal resonance effect is achieved, and the signal strength and the sensitivity are improved; the positioning columns are isolated to form annular gaps, so that air and redundant adhesive can be discharged, the thickness of the matching layer is uniform, and the signal quality and the yield are improved; the integrated forming design is adopted, the structure is compact, the structure is firm and durable, the production cost is reduced, the production efficiency is improved, and the integrated forming die is suitable for large-scale production.

Claims

1. An ultrasonic sensor is provided with a casing, which is characterized in that: the casing is a cylindrical structure with the lower end closed and the upper end opened, a glaze firing layer is arranged on the outer surface of the casing, a positioning column is axially arranged on the inner wall of the casing, a matching layer, a piezoelectric ceramic piece, a back lining layer and a potting layer are sequentially arranged in a cavity of the casing from bottom to top, and a signal cable penetrates through the potting layer and the back lining layer and is welded on the positive electrode and the negative electrode of the piezoelectric ceramic piece.

2. The ultrasonic transducer of claim 1, wherein the cavity of the housing is cylindrical in configuration.

3. The ultrasonic transducer of claim 1, wherein the piezoceramic wafer is positioned in the center of the housing.

4. The ultrasonic transducer of claim 1, wherein the number of the positioning posts is at least three, and the positioning posts are uniformly distributed on the inner wall of the housing.

5. The ultrasonic transducer of claim 1, wherein an annular gap is formed between the inner wall of the housing and the outer edge of the piezoelectric ceramic plate.

6. The ultrasonic transducer of claim 1, wherein the housing is formed by firing an electronic ceramic material.