A nano-thin film pressure measurement sensor

Abstract

The present invention belongs to the field of sensor technology, and specifically relates to a nano film pressure measurement sensor. It includes an output seat, a connection cover, a core assembly, a core mounting seat and a pressure-drawing base arranged from top to bottom, the output seat is connected to the connection cover, the interior of the connection cover is a cavity structure, the cavity structure inside the connection cover is provided with a core assembly, the lower part of the connection cover is connected to the core mounting seat, and the core mounting seat and the pressure-drawing base are connected. The beneficial effect of the present invention is that it can be applied to the design and manufacture of high-precision transmitters, effectively avoiding the external stress and damage of the flange clamping pressure-taking structure on the sensor core, and improving the stability and reliability of the sensor core.

Description

Technical Field

[0001] The invention belongs to the technical field of sensors, and in particular relates to a nano film pressure measuring sensor. Background Art

[0002] Existing nuclear power plants require a large number of pressure sensors or transmitters to measure and control physical quantities such as system pressure, liquid level, and flow. At present, the use of transmitters for most nuclear power plants is still basically at the stage of traditional physical property transmitters. The capacitive transmitters currently used have problems such as large size and the need to fill with silicone oil; the pressure taking structure adopts a bolt clamping type, which makes installation inconvenient and the flange stress cannot be effectively eliminated. After long-term use, the transmitter has problems such as low sensitivity and slow response time, which cannot effectively meet the technical requirements of nuclear power for the long-term stability and reliability of the transmitter. Summary of the invention

[0003] The purpose of the present invention is to provide a nano-thin film pressure measurement sensor, which supports the sensor core by a pressure-taking tube and an exhaust pipe to form a suspended state in a protective shell, which can effectively reduce the contact pressure area between the core and the outside world, eliminate the stress influence of flanges and bolts, solve the disadvantage of high stress caused by the clamping of the pressure-taking flange on the sensor core of the capacitive transmitter, and improve the repeatability and accuracy of the sensor measurement.

[0004] The technical scheme of the present invention is as follows: a nano film pressure measurement sensor, comprising an output seat, a connecting cover, a core assembly, a core mounting seat and a pressure-drawing base arranged from top to bottom, the output seat is connected to the connecting cover, the interior of the connecting cover is a cavity structure, the cavity structure inside the connecting cover is provided with a core assembly, the lower part of the connecting cover is connected to the core mounting seat, and the core mounting seat and the pressure-drawing base are connected; the upper part of the core assembly is connected to two exhaust pipes, the other end of the exhaust pipe is fixed to the connecting cover, the lower part of the core assembly is connected to two pressure-taking pipes, the two pressure-taking pipes are used to introduce the medium to be measured, the core assembly is provided with a low-pressure chamber and a high-pressure chamber, one end of one of the two pressure-taking pipes is fixed to the low-pressure chamber, and one end of the other of the two pressure-taking pipes is connected to the high-pressure chamber The core assembly comprises a bridge arm core assembly, a glass sintered connecting ring, a low-pressure cavity welding assembly and a high-pressure side protection block, wherein the glass sintered connecting ring is respectively connected to the bridge arm core assembly and the low-pressure cavity welding assembly on both sides, the interior of the bridge arm core assembly is a cavity structure, the end face of the bridge arm core assembly is connected with a high-pressure side cover, a high-pressure side protection block and a glass sintered connecting ring are arranged on one side of the bridge arm core assembly close to the glass sintered connecting ring; the measuring diaphragm is connected to the end face of the high-pressure cavity diaphragm to form a bridge arm core assembly, and is sintered together with the glass sintered connecting ring; after the bridge arm core assembly is fixed by the lower end of the pressure taking pipe and the upper end of the exhaust pipe, the exhaust pipe and the pressure taking pipe are used as support to make the sensor core suspended inside the transmitter to form a suspended state.

[0005] A plurality of stress grooves are provided on one side where the bridge arm core assembly is connected to the glass sintered connecting ring to reduce the influence of the welding stress of the core on the measuring diaphragm.

[0006] The pressure-inducing base is provided with a pressure-taking hole, a medium flow channel and a sensor sewage discharge hole, and the pressure-taking hole and the sensor sewage discharge hole are respectively connected to the pressure-inducing base.

[0007] The pressure-taking hole, the sensor drain hole and the medium flow channel are located on the same axis and are interconnected. The medium flows between the flow channels and finally reaches the core assembly through the internal pipeline of the pressure-leading base and the pressure-taking pipe for pressure measurement.

[0008] A PCB board assembly is arranged in the connection cover.

[0009] The output seat is provided with a flange seat and a vent valve assembly.

[0010] The beneficial effects of the present invention are:

[0011] 1) The present invention can be applied to the design and manufacture of high-precision transmitters, effectively avoiding the external stress and damage effects of the flange clamping pressure taking structure on the sensor core, and improving the stability and reliability of the sensor core.

[0012] 2) The welding stress groove structure design method described in the present invention effectively weakens the influence of the welding stress caused by the core welding process on the measuring diaphragm, and improves the stability and repeatability of the measuring diaphragm.

[0013] 3) The bottom-up pressure taking and waste gas exhaust structure of the present invention can effectively remove impurities and gas residues in the sensor core, greatly improving the accuracy of the sensor measurement diaphragm.

[0014] 4) By applying the overpressure protection measures and the direct contact between the medium and the measuring diaphragm described in the present invention, the pressure of the measured medium can be directly sampled, the influence of silicone oil and isolation diaphragm in the capacitive transmitter is completely eliminated, the intermediate links of pressure transmission are reduced, and the measuring diaphragm is protected from deformation and failure due to excessive pressure difference on both sides, which effectively improves the sensitivity and measurement accuracy of the sensor core measurement.

[0015] 5) The redundant dual-channel exhaust and sewage discharge structure design ensures that the gas and impurities in the measuring medium and sensor core can be effectively discharged, reducing the impact on measurement accuracy and measurement stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of a nano film pressure measurement sensor provided by the present invention;

[0017] Figure 2A cross-sectional view of a nano-thin film pressure measurement sensor provided by the present invention;

[0018] Figure 3 Schematic diagram of suspension assembly of nano-film pressure measurement sensor;

[0019] Figure 4 This is the structural diagram of the pressure core assembly;

[0020] Figure 5 A schematic diagram of the pressure taking process of a nano-thin film pressure measurement sensor provided by the present invention;

[0021] Figure 6 This is a schematic diagram of the exhaust and sewage treatment of a nano-thin film pressure measurement sensor provided by the present invention.

[0022] In the figure: 201 pressure-leading base, 202 core mounting base, 203 core assembly, 204 connecting cover, 205 output seat, 301 pressure-taking tube, 302 exhaust pipe, 401 bridge arm core assembly, 402 glass sintered connecting ring, 403 low-pressure chamber welding assembly, 404 stress groove, 405 high-pressure side protection block, 406 high-pressure side cover, 501 low-pressure chamber, 502 high-pressure chamber, 503 PCB board assembly, 504 electrical connector, 505 vent valve, 601 pressure-taking hole, 602 medium flow channel, 603 exhaust plug, 604 sensor drain valve. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] The nano film pressure measurement sensor of the present invention is based on the existing semiconductor-like steel-based material, and adopts nano film deposition and precision photolithography technology to deposit the nano film functional material on the steel-based elastomer to generate a strain sensitive circuit, and make it into a pressure measurement sensitive core. Therefore, the nano film strain pressure sensor has the advantages of high precision, good stability, wide temperature range, no oil filling, and small size. Since the sensor is made of metal material, the influence of welding stress and welding temperature is fully considered. A unique stress groove is designed when designing the sensor core structure, and a low-temperature laser welding method is adopted to ensure that the welding stress is reduced to a minimum. At the same time, based on the floating ball principle, the sensor suspension structure is creatively designed. Through the pressure taking pipe and exhaust pipe support design, the sensor core is suspended to form a suspended state in the protective shell. This design reduces the pressure area between the core and the outside world, eliminates the stress influence of flanges and bolts, and improves the repeatability and accuracy of sensor measurement.

[0025] The nano-film pressure measurement sensor of the present invention adopts a suspended design structure and can be used for differential pressure, gauge pressure and absolute pressure transmitters. The suspended structure design, which is the core of the present invention, connects the pressure-taking structure and the core measurement through the only pressure-taking pipe through the ingenious innovation of the sensor core installation arrangement, effectively solving the external stress and damage of the flange clamping pressure-taking structure to the sensor core, and improving the stability and reliability of the sensor core.

[0026] like Figure 1-6 As shown, a nano film pressure measurement sensor provided by the present invention includes an output seat 205, a connection cover 204, a core assembly 203, a core mounting seat 202 and a pressure-inducing base 201 arranged from top to bottom. The output seat 205 and the connection cover 204 are connected by bolts, and the interior of the connection cover 204 is a cavity structure, such as Figure 5 As shown, the PCB assembly 503 is connected and fixed in the connection cover 204 by screws, as shown in FIG. Figure 2 As shown, an electrical connector 504 and a vent valve 505 are installed on the output seat 205, and the exhaust plug 603 is connected to the vent valve 505 through a thread. The cable inside the electrical connector 504 plays a role in data transmission and power supply of the entire sensor; the lower part of the connecting cover 204 and the core mounting seat 202 are connected by welding, and the cavity structure inside the connecting cover 204 wraps the core assembly 203, as shown in FIG. Figure 3 As shown, the upper part of the core assembly 203 is connected to two exhaust pipes 302 by welding, and the other end of the exhaust pipe 302 is fixed to the connecting cover 204 by welding. The lower part of the core assembly 203 is connected to two pressure-taking pipes 301 by welding. The two pressure-taking pipes 301 are used to introduce the medium to be measured. The core assembly 203 is provided with a low-pressure chamber 501 and a high-pressure chamber 502. One end of one of the two pressure-taking pipes 301 is fixed to the low-pressure chamber 501 by welding, and the other end is fixed to the pressure-leading base 201 by welding. One end of the other of the two pressure-taking pipes 301 is fixed to the high-pressure chamber 502 by welding, and the other end is also fixed to the pressure-leading base 201 by welding. The core mounting seat 202 and the pressure-leading base 201 are connected by bolts, as shown in FIG. Figure 6 As shown, the pressure-taking hole 601, the medium flow channel 602 and the sensor drain valve 604 are provided on the pressure-taking base 201. The pressure-taking hole 601 and the sensor drain valve 604 are respectively connected to the pressure-taking base 201 through threaded assembly. The pressure-taking hole 601, the sensor drain valve 604 and the medium flow channel 602 are located on the same axis and are interconnected. The medium flows between the flow channels and finally reaches the core assembly 203 through the internal pipeline of the pressure-taking base 201 and the pressure-taking pipe 301 for pressure measurement.

[0027] The pressure-taking pipe 301 and the exhaust pipe 302 are both made of 316L stainless steel. The two exhaust pipes 302 discharge the gas in the medium in the high and low pressure chambers of the core through the exhaust plug on the upper output seat, and the two pressure-taking pipes 301 introduce the medium to be measured from the pressure-taking port on the pressure-leading base. The pressure-taking pipe 301 is 41 mm long, 4.10 mm in outer diameter, and 2 mm in inner diameter; the exhaust pipe 302 is 22 mm long, 3.40 mm in outer diameter, and 1.00 mm in inner diameter.

[0028] like Figure 4 As shown, the core assembly 203 includes a bridge arm core assembly 401, a glass sintered connecting ring 402, a low-pressure chamber welding assembly 403 and a high-pressure side protection block 405, wherein the glass sintered connecting ring 402 is respectively connected to the bridge arm core assembly 401 and the low-pressure chamber welding assembly 403 on both sides by welding. In order to avoid the influence of the welding molten pool and stress on the pressure-taking chip in the radial direction, a plurality of stress grooves 404 are opened on the side where the bridge arm core assembly 401 is connected to the glass sintered connecting ring 402 to reduce the influence of the welding stress of the core on the measuring diaphragm. The interior of the bridge arm core assembly 401 is a cavity structure, and the end face of the bridge arm core assembly 401 is connected to the high-pressure side cover 406 by bolts. A high-pressure side protection block 405 is provided on the side of the bridge arm core assembly 401 close to the glass sintered connecting ring 402. The glass sintered connecting ring 402, the bridge arm core assembly 401 and the low-pressure cavity welding assembly 403 are welded by low-temperature laser welding to reduce the welding temperature to room temperature, reduce the welding stress to a minimum, and make the influence of the welding temperature on the measuring diaphragm under control, thereby effectively improving the stability and repeatability of the measuring diaphragm and the sensor core.

[0029] The bridge arm core assembly 401 includes a high-pressure cavity and a circular bridge arm measuring diaphragm, and the interior is a cavity structure. The circular bridge arm measuring diaphragm adopts nano-thin film deposition and precision photolithography technology to deposit nano-thin film functional materials on a semiconductor-like steel-based elastomer to generate a strain sensitive circuit, and is made into a pressure measurement sensitive circuit. The circular bridge arm measuring diaphragm is connected to the end face of the high-pressure cavity diaphragm by welding to form a bridge arm core assembly, and is sintered together with the glass sintering connecting ring 402 by glass sintering. A high-pressure side protection block is provided on one side of the bridge arm core assembly 401 close to the glass sintering connecting ring 402. The high-pressure cavity includes a pressure inlet hole, an exhaust hole, a high-pressure side protection block and a cover.

[0030] The bridge arm core assembly 401 is provided with a low-pressure chamber and a high-pressure chamber, and an exhaust pipe and a pressure-taking pipe are installed at the upper and lower parts of the high-pressure chamber and the low-pressure chamber, respectively. The upper ends of the two exhaust pipes welded at the upper part of the high and low-pressure chambers of the core assembly are respectively welded and fixed to the exhaust holes of the upper output seat, and the lower ends of the two pressure-taking pipes welded at the lower part of the high and low-pressure chambers of the core assembly are respectively welded and fixed to the bottom of the lower core mounting seat. After the entire bridge arm core assembly 401 is fixed by the lower end of the pressure-taking pipe and the upper end of the exhaust pipe, the exhaust pipe and the pressure-taking pipe are used as support to make the sensor core suspended inside the transmitter to form a suspended state.

[0031] like Figure 5 and Figure 6 As shown, when the sensor is working, the measuring medium enters the pressure holes 601 on the positive and negative pressure sides of the pressure-inducing assembly respectively, and enters the pressure-inducing pipe 301 and the drain valve 604 of the core body through the medium flow channel 602 on the pressure-inducing assembly, and performs the first drain and exhaust operation through the drain valve 604. After the drain and exhaust operation is completed, the measured medium enters the low-pressure chamber 501 and the high-pressure chamber 502 from bottom to top respectively from the two pressure-inducing pipes 301; the medium in the low-pressure chamber 501 acts on the measuring diaphragm through the holes of the high-pressure side protection block, and the medium in the high-pressure chamber 502 directly acts on the measuring diaphragm; then the gas in the low-pressure chamber and the high-pressure chamber is discharged upward through the vent valve 505 and the exhaust plug 603 connected to the two exhaust pipes 302. The two-way drain and exhaust design and the bottom-up pressure and exhaust method can effectively remove the residual bubbles in the pressure-inducing assembly and the sensor core, and improve the accuracy of the pressure-inducing chip.

[0032] The main improvement of the present invention is that two structural parts, the core mounting seat 202 and the connecting cover 204, are added. The core assembly 203 is suspended in the air and connected to the sensor housing only through two positive and negative pressure side pressure pipes 301 and two exhaust pipes 302. The core assembly 203 is changed from the original horizontal arrangement clamped by the pressure flange to a suspended vertical arrangement, and the assembly stress received by the measuring diaphragm of the sensor core is also changed from the original axial stress with a greater impact to the radial stress with a smaller impact.

[0033] like Figure 3As shown, the sensor of the present invention adopts a special assembly method in the manufacturing process. When assembling the sensor, the exhaust pipe 302 is connected to the core assembly 203 through threads and welded (welding 304), and the pressure-taking pipe 301 is connected to the core assembly 203 through threads to form a whole and welded (welding 305); then the other end of the pressure-taking pipe 301 of the component is inserted into the core mounting seat for fixation, and welded at the end (welding 307); then the connection cover 204 is inserted into the exhaust pipe 302 from top to bottom, and the connection cover 204 and the core mounting seat 202 are welded at the joint (welding 306), the purpose is to let the connection cover 204 and the core mounting seat 202 bear the structural pressure and welding stress of the entire sensor, and eliminate the clamping stress of the pressure-taking flange; finally, the end of the exhaust pipe 302 and the connection cover 204 are welded and fixed (welding 303).

[0034] When the sensor of the present invention is working, the measuring medium enters the positive and negative pressure sides of the pressure-drawing assembly respectively, and the first sewage and exhaust operation is performed through the sewage valve on the pressure-taking assembly. After the sewage and exhaust operation is completed, the measured medium enters the low-pressure chamber and the high-pressure chamber from the bottom to the top respectively from the two pressure-taking pipes; the medium in the low-pressure chamber acts on the measuring diaphragm through the holes of the high-pressure side protection block, and the medium in the high-pressure chamber directly acts on the measuring diaphragm; then the gas in the low-pressure chamber and the high-pressure chamber is discharged upward through the two exhaust pipes. The two-way sewage and exhaust design and the bottom-up pressure-taking and exhaust method can effectively remove the residual bubbles in the pressure-drawing assembly and the sensor core, and improve the accuracy of the pressure-taking chip.

[0035] The nano-film pressure measurement sensor provided by the present invention can be used for differential pressure, gauge pressure and absolute pressure transmitters. The core suspension structure design of the present invention connects the pressure-taking structure and the core measurement through the only pressure-taking pipe through the ingenious sensor core installation layout innovation, effectively solving the external stress and damage of the flange clamping pressure-taking structure to the sensor core, and improving the stability and reliability of the sensor core.

Claims

1. A nano film pressure measurement sensor, characterized in that: It includes an output seat, a connecting cover, a core assembly, a core mounting seat and a pressure-leading base arranged from top to bottom, the output seat is connected to the connecting cover, the interior of the connecting cover is a cavity structure, the cavity structure inside the connecting cover is provided with a core assembly, the lower part of the connecting cover is connected to the core mounting seat, and the core mounting seat is connected to the pressure-leading base; the upper part of the core assembly is connected to two exhaust pipes, the other end of the exhaust pipe is fixed to the connecting cover, the lower part of the core assembly is connected to two pressure-taking pipes, the two pressure-taking pipes are used to introduce the medium to be measured, the core assembly is provided with a low-pressure chamber and a high-pressure chamber, one end of one of the two pressure-taking pipes is fixed to the low-pressure chamber, and one end of the other of the two pressure-taking pipes is fixed to the high-pressure chamber, the core assembly includes a bridge arm core assembly, a glass sintered connecting ring, a low-pressure chamber welding assembly and a high-pressure side protection block, wherein the glass sintered The two sides of the connecting ring are respectively connected to the bridge arm core assembly and the low-pressure chamber welding assembly. The interior of the bridge arm core assembly is a cavity structure. The end face of the bridge arm core assembly is connected to a high-pressure side cover. A high-pressure side protection block and a glass sintered connecting ring are arranged on one side of the bridge arm core assembly close to the glass sintered connecting ring. The measuring diaphragm is a strain sensitive circuit generated by depositing nano-thin film functional materials on a steel-based elastomer. The measuring diaphragm is connected to the end face of the high-pressure chamber diaphragm to form a bridge arm core assembly, and is sintered together with the glass sintered connecting ring. The medium of the low-pressure chamber acts on the measuring diaphragm through the holes of the high-pressure side protection block, and the medium of the high-pressure chamber directly acts on the measuring diaphragm. After the bridge arm core assembly is fixed by the lower end of the pressure taking pipe and the upper end of the exhaust pipe, the exhaust pipe and the pressure taking pipe are used as support to make the sensor core suspended inside the transmitter.

2. A nano film pressure measurement sensor as claimed in claim 1, characterized in that: A plurality of stress grooves are provided on one side where the bridge arm core assembly is connected to the glass sintered connecting ring to reduce the influence of the welding stress of the core on the measuring diaphragm.

3. A nano film pressure measurement sensor as claimed in claim 1, characterized in that: The pressure-inducing base is provided with a pressure-taking hole, a medium flow channel and a sensor sewage discharge hole, and the pressure-taking hole and the sensor sewage discharge hole are respectively connected to the pressure-inducing base.

4. A nano film pressure measurement sensor as claimed in claim 3, characterized in that: The pressure-taking hole, the sensor drain hole and the medium flow channel are located on the same axis and are interconnected. The medium flows between the flow channels and finally reaches the core assembly through the internal pipeline of the pressure-leading base and the pressure-taking pipe for pressure measurement.

5. The nano film pressure measurement sensor according to claim 1, characterized in that: A PCB board assembly is arranged in the connection cover.

6. The nano film pressure measurement sensor according to claim 1, characterized in that: The output seat is provided with a flange seat and a vent valve assembly.

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