High-pressure gas pressure control and calibration device

Abstract

The invention provides a high-pressure gas pressure control and calibration device which comprises a bottom plate, and a gas source, a first pressure reducing valve, a second pressure reducing valve, an electromagnetic switch valve, a servo valve, a pneumatic control stop valve, a pressure containing cavity, a servo motor, a transmission mechanism and a standard pressure sensor which are mounted on the bottom plate, the air source is connected with the first pressure reducing valve and the second pressure reducing valve. The second pressure reducing valve is connected with the power end of the pneumatic control stop valve; the electromagnetic switch valve, the servo valve, the pneumatic control stop valve and the pressure containing cavity are sequentially connected through pipelines. The pressure containing cavity comprises a cavity body, an end cover and a piston, the cavity body is connected with the pneumatic control stop valve through a pipeline, and the cavity body is further used for being connected with a to-be-tested pressure sensor; the end cover is hermetically connected with the cavity; the piston is movably and hermetically connected to the inner wall of the cavity; the standard pressure sensor is connected with the cavity; and the transmission mechanism is respectively connected with the servo motor and the piston. According to the device, the pressure in the pressure containing cavity can be rapidly adjusted through the servo valve, the piston can be driven by the servo motor to move in the pressure containing cavity, then pressure changes in the pressure containing cavity caused by temperature, gas leakage and other reasons are compensated in a small range, the inflation and deflation frequency of the servo valve is reduced, and the service life of the device is prolonged. The control stability of the system is prevented from being affected by dew formation and freezing phenomena generated by long-time working of the servo valve, and meanwhile the accuracy, reliability and safety of the calibration device are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of pressure gauges, and in particular to a high-pressure gas pressure control and calibration device. Background Art

[0002] High-precision pressure sensors have been widely used in fields such as industrial automation, medical equipment, and environmental monitoring. Factors such as long-term use and improper operation can cause errors in pressure sensors. With the continuous improvement of the requirements for the measurement accuracy of pressure sensors, the calibration of the response curve of the sensor under high air pressure is a necessary step.

[0003] In the prior art, the invention patent with the patent publication number CN117470469A discloses a pressure measurement and control system and method based on gas. The main components of this device include a PLC controller, a flow regulating valve, and a solenoid valve. After the gas source fills the gas cylinder to a certain value, the first solenoid valve is closed, and the second solenoid valve is opened. The standard pressure sensor and the sensor to be measured are connected through the test circuit to calibrate and verify the pressure sensor on site. The invention patent with the patent publication number CN105606318A discloses a calibration method and device for an airtight leak detector, which adjusts and compensates the pressure through a flow control valve and uses a standard digital pressure gauge to calibrate the leak rate of a flow-type airtight detector. The utility model patent with the patent publication number CN204346638U discloses a pressure verification / calibration device, which takes a digital pressure gauge as the core device and is equipped with a highly reliable booster pump and a flow control valve to calibrate and verify the pressure sensor on site.

[0004] In the above patents, the high-pressure pressure control devices all use high-pressure gas sources. Phase change condensation and icing may occur with the changes in pressure and temperature. This phenomenon exists in large quantities in nature and the industrial field. When the flow control valve is used to adjust the gas flow for a long time, the compressed gas at the valve port expands rapidly, resulting in a decrease in pressure and temperature, and the condensation and icing phenomenon becomes more serious and intense, which has a great impact on the control performance, reliability, and safety of the calibration device. Summary of the Invention

[0005] In view of this, the present invention proposes a high-pressure gas pressure control and calibration device to solve the technical problem that when the flow control valve is used to adjust the gas flow for a long time, the compressed gas at the valve port expands rapidly, resulting in a decrease in pressure and temperature, and the condensation and icing phenomenon becomes more serious and intense, which has a great impact on the control performance, reliability, and safety of the calibration device as mentioned in the above background art.

[0006] The technical solution of the present invention is realized as follows:

[0007] The present invention provides a high-pressure gas pressure control and calibration device, which includes a bottom plate, a gas source, and a first pressure reducing valve, a second pressure reducing valve, an electromagnetic switch valve, a servo valve, a pneumatic control stop valve, a pressure chamber, a servo motor, a transmission mechanism, and a standard pressure sensor mounted on the bottom plate, wherein:

[0008] The gas source is respectively connected to the first pressure reducing valve and the second pressure reducing valve;

[0009] The second pressure reducing valve is connected to the power end of the pneumatic control stop valve and is used to reduce the gas source pressure to the stable operating pressure of the pneumatic control stop valve;

[0010] The electromagnetic switch valve, the servo valve, the pneumatic control stop valve, and the pressure chamber are sequentially connected through pipelines;

[0011] The pressure chamber includes a cavity, an end cover, and a piston. The cavity is connected to the pneumatic control stop valve through a pipeline, and the cavity is also used to connect to a pressure sensor to be measured; the end cover is hermetically connected to the cavity; the piston is movably and hermetically connected to the inner wall of the cavity and is used to form a sealed chamber with the inner wall of the cavity;

[0012] The standard pressure sensor is connected to the cavity;

[0013] The transmission mechanism is respectively connected to the servo motor and the piston and is used to drive the piston to perform a linear motion under the drive of the servo motor to realize the change of the volume of the sealed chamber.

[0014] On the basis of the above technical solutions, preferably, the device further includes a controller. The controller is respectively electrically connected to the electromagnetic switch valve, the servo valve, the pneumatic control stop valve, the servo motor, and the standard pressure sensor; the standard pressure sensor is used to detect the pressure in the sealed chamber and send the pressure data to the controller; the controller is used to compare the received pressure data with the pressure instruction, and control the spool of the servo valve to perform displacement according to the comparison result to realize the inflation and deflation of the sealed chamber, or control the servo motor to rotate to drive the piston to perform a linear motion to realize the change of the volume of the sealed chamber.

[0015] On the basis of the above technical solutions, preferably, in the first stage, the servo motor is kept stationary, and the controller is used to send a displacement instruction to the servo valve to realize the inflation and deflation of the sealed chamber; in the second stage, the controller controls to close the electromagnetic switch valve, the servo valve, and the pneumatic control stop valve, and sends a rotation instruction to the servo motor. The servo motor drives the piston to perform a linear motion along the inner wall of the cavity through the transmission mechanism to realize the change of the volume of the sealed chamber.

[0016] Based on the above technical solutions, preferably, a displacement sensor is installed inside the servo valve. The displacement sensor is used to collect and detect the displacement data of the spool in real time, and send the collected displacement data to the controller. The controller is used to send a displacement command to the servo valve according to the displacement data to achieve inflation and deflation of the sealed chamber.

[0017] Based on the above technical solutions, preferably, the transmission mechanism includes a coupling, a ball screw, a nut, and a transmission piece. The coupling is respectively connected to the servo motor and the ball screw. The ball screw is rotatably installed on the bottom plate. The nut is threadedly connected to the ball screw. The transmission piece is respectively connected to the nut and the piston.

[0018] Based on the above technical solutions, preferably, the change range of the volume of the sealed chamber is 70 - 80.6 mm 2 。

[0019] Based on the above technical solutions, preferably, the electromagnetic switch valve is used to control the gas from the first pressure reducing valve to enter the servo valve, serving as the switch of the device. The pneumatic shut-off valve is used to close when powered off to maintain the gas pressure in the pressure chamber after the servo valve stops controlling.

[0020] Based on the above technical solutions, preferably, the side wall of the cavity is provided with a first connection hole, a second connection hole, and a third connection hole. The first connection hole is used to connect the pneumatic shut-off valve to achieve inflation and deflation of the sealed chamber. The second connection hole is used to connect the standard pressure sensor to measure the pressure inside the sealed chamber. The third connection hole is used to connect the pressure sensor to be measured for pressure feedback.

[0021] Based on the above technical solutions, preferably, it further includes a control box. The control box includes a box body, an upper cover, and a control screen. The top of the box body is open. The upper cover is connected to the top opening of the box body. The bottom plate is installed on the bottom surface of the box body and is located inside the box body. The control screen is installed on the side of the box body and is electrically connected to the controller to send a pressure command signal and a start / stop signal of the device to the controller.

[0022] Based on the above technical solutions, preferably, the side of the box body is provided with a first mounting hole and a second mounting hole. The first mounting hole is used for the input pipeline of the gas source to pass through. The second mounting hole is used for the pressure output pipeline of the sealed chamber to pass through to connect to the pressure sensor to be measured.

[0023] The high-pressure gas pressure control and calibration device of the present invention has the following beneficial effects compared with the prior art:

[0024] (1) It is possible to quickly adjust the pressure in the pressure chamber by using a servo valve, and at the same time, the piston can be driven by a servo motor to move in the pressure chamber, thereby compensating for the pressure change in the pressure chamber caused by reasons such as temperature and gas leakage in a small range, reducing the charging and discharging frequency of the servo valve, preventing the phenomenon of condensation and icing during the long-term operation of the servo valve, which affects the control stability of the system, and improving the accuracy, reliability, and safety of the calibration device.

[0025] (2) The controller compares the received pressure data with the pressure command, and controls the displacement of the spool of the servo valve according to the comparison result to achieve the inflation and deflation of the sealed chamber, or controls the servo motor to rotate to drive the piston to move linearly to achieve the change of the volume of the sealed chamber, so as to quickly adjust the pressure in the pressure chamber by using the servo valve, or use the servo motor to continuously compensate for the pressure difference caused by temperature and gas leakage within a certain range for a long time.

[0026] (3) In the first stage, the servo motor is kept stationary and the volume of the sealed chamber remains unchanged. The controller is used to send a displacement command to the servo valve to achieve the inflation and deflation of the sealed chamber, and quickly adjust the pressure in the pressure chamber by using the servo valve. In the second stage, the controller controls the electromagnetic switch valve, the servo valve, and the pneumatic cut-off valve to be closed, and sends a rotation command to the servo motor. The servo motor drives the piston to move linearly along the inner wall of the chamber through a transmission mechanism, realizing the change of the volume of the sealed chamber, and further compensating for the pressure change in the pressure chamber caused by reasons such as temperature and gas leakage in a small range, reducing the charging and discharging frequency of the servo valve.

[0027] (4) A displacement sensor is installed inside the servo valve. The displacement sensor is used to collect and detect the displacement data of the spool in real time, and send the collected displacement data to the controller. The controller is used to send a displacement command to the servo valve according to the displacement data to achieve the inflation and deflation of the sealed chamber, realizing a high-precision servo control closed loop of the pressure of the servo valve, and ensuring the calibration accuracy and response speed during calibration measurement.

[0028] (5) The electromagnetic switch valve is used to control the gas from the first pressure reducing valve to enter the servo valve, and its function is the switch of the device. After being powered on, it can let air through, and is used to control the on-off of the air flow between the air source and the servo valve. The initial state of the pneumatic cut-off valve is to let air through, and it is used to cut off the power supply to close, so as to maintain the gas pressure in the pressure chamber after the servo valve stops controlling, which can avoid frequent start and stop of the system, increase the service life of the servo valve, and improve the control performance of the calibration system. Description of the Drawings

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0030] Figure 1 It is a schematic diagram of the principle of the high-pressure gas pressure control and calibration device in the embodiment of the present invention;

[0031] Figure 2 It is a three-dimensional view of the high-pressure gas pressure control and calibration device in the embodiment of the present invention;

[0032] Figure 3 It is a top view of the high-pressure gas pressure control and calibration device in the embodiment of the present invention;

[0033] Figure 4 It is a schematic diagram of the structure of the servo motor and the transmission mechanism in the embodiment of the present invention;

[0034] Figure 5 It is a schematic diagram of the structure of the pressure chamber in the embodiment of the present invention;

[0035] Figure 6 It is a schematic diagram of the structure of the control box in the embodiment of the present invention.

[0036] Explanation of reference numerals: 100 - gas source input pipeline, 101 - pressure output pipeline, 102 - first filter, 103 - second filter;

[0037] 200 - pressure chamber, 201 - end cover, 202 - cavity, 203 - piston;

[0038] 300 - servo motor, 301 - reducer, 302 - coupling, 303 - first bearing, 304 - ball screw, 305 - nut, 306 - drive plate, 307 - second bearing, 308 - motor driver;

[0039] 400 - first pressure reducing valve, 401 - second pressure reducing valve, 402 - electromagnetic switching valve, 403 - servo valve, 404 - pneumatic cut-off valve, 405 - displacement sensor amplifier, 406 - silencer;

[0040] 500 - bottom plate, 501 - mounting bracket;

[0041] 600 - standard pressure sensor, 601 - sensor mounting bracket;

[0042] 700 - power input and switch;

[0043] 800 - Upper cover, 801 - Box body, 802 - Control screen. Detailed implementation mode

[0044] The following will combine the implementation modes of the present invention to clearly and completely describe the technical solutions in the implementation modes of the present invention. Obviously, the described implementation modes are only a part of the implementation modes of the present invention, rather than all of the implementation modes. Based on the implementation modes in the present invention, all other implementation modes obtained by those of ordinary skill in the art without creative work belong to the protection scope of the present invention.

[0045] Refer to Figure 1-6 As shown, an embodiment of the present invention provides a high-pressure gas pressure control and calibration device, which includes a bottom plate 500, a gas source and a power input and switch 700, as well as a first pressure reducing valve 400, a second pressure reducing valve 401, an electromagnetic switch valve 402, a servo valve 403, a pneumatic control stop valve 404, a pressure chamber 200, a servo motor 300, a transmission mechanism and a standard pressure sensor 600 installed on the bottom plate 500, where:

[0046] The power input and switch 700 is arranged on the bottom plate 500 to realize the power supply of the entire device and the control of power on and off;

[0047] The gas source is respectively connected to the first pressure reducing valve 400 and the second pressure reducing valve 401; the compressed gas of the gas source enters the device through the gas source input pipeline 100. The gas source input pipeline 100 is connected to a first filter 102. After most of the impurities are filtered by the first filter 102, the gas is divided into two paths and enters the first pressure reducing valve 400 and the second pressure reducing valve 401 respectively to prevent impurities from damaging the subsequent pipelines and devices; one path passes through the first pressure reducing valve 400 to reduce the gas source pressure to the stable working pressure of the system, and one path passes through the second pressure reducing valve 401 to reduce the gas source pressure to the stable working pressure of the pneumatic control stop valve 404;

[0048] The second pressure reducing valve 401 is connected to the power end of the pneumatic control stop valve 404 to reduce the gas source pressure to the stable working pressure of the pneumatic control stop valve 404;

[0049] The electromagnetic switch valve 402, the servo valve 403, the pneumatic control stop valve 404 and the pressure chamber 200 are sequentially connected through pipelines; after the gas is depressurized by the first pressure reducing valve 400, it sequentially passes through the electromagnetic switch valve 402, the servo valve 403 and the pneumatic control stop valve 404 and enters the pressure chamber 200; adding a pneumatic control stop valve 404 between the servo valve 403 and the pressure chamber 200 for pressure holding can avoid frequent start and stop of the system, increase the service life of the servo valve 403, and improve the control performance of the calibration system; in order to reduce the noise during the gas discharge of the device, a silencer 406 is installed at the exhaust port of the servo valve 403;

[0050] The pressure chamber 200 includes a chamber body 202, an end cover 201, and a piston 203. The chamber body 202 is connected to the pneumatic shut-off valve 404 through a pipeline. The chamber body 202 is also used to connect to the pressure sensor to be measured. The chamber body 202 is connected to the pressure sensor to be measured through a pressure output pipeline 101. A second filter 103 is provided on the pressure output pipeline 101. After the gas passes through the second filter 103 to filter out impurities, it enters the pressure sensor to be measured, preventing the impurities from affecting the measurement accuracy of the pressure sensor to be measured. The end cover 201 is hermetically connected to the chamber body 202. The piston 203 is movably and hermetically connected to the inner wall of the chamber body 202 for forming a sealed chamber with the inner wall of the chamber body 202. One end of the piston 203 extends into the inner wall of the chamber body 202, and the other end is connected to a transmission mechanism. A sealing ring is sleeved on the piston 203 to prevent the gas in the sealed chamber from leaking. The end cover 201 and the chamber body 202 are connected by screws, and there is a sealing ring at the contact to reduce the gas leakage in the sealed chamber.

[0051] The standard pressure sensor 600 is connected to the chamber body 202 to measure the pressure value in the pressure chamber 200 in real time. The standard pressure sensor 600 is fixed on the mounting bracket 501 of the bottom plate 500 through a sensor mounting bracket 601.

[0052] The transmission mechanism is respectively connected to the servo motor 300 and the piston 203, and is used to drive the piston 203 to perform a linear motion under the drive of the servo motor 300, so as to realize the change of the volume of the sealed chamber.

[0053] The high-pressure gas pressure control and calibration device proposed in this embodiment can not only quickly adjust the pressure in the pressure chamber 200 by using the servo valve 403, but also drive the piston 203 to move in the pressure chamber 200 through the servo motor 300, thereby compensating for the pressure change in the pressure chamber 200 caused by reasons such as temperature and gas leakage in a small range, reducing the charging and discharging frequency of the servo valve 403, preventing the servo valve 403 from generating condensation and icing phenomena during long-term operation, which affects the control stability of the system, and at the same time improving the accuracy, reliability and safety of the calibration device. The initial state of the pneumatic shut-off valve 404 is ventilated, and its function is to close when powered off to maintain the gas pressure in the pressure chamber 200 after the servo valve stops controlling.

[0054] In some embodiments, the high-pressure gas pressure control and calibration device further includes a controller, and the controller in this embodiment refers to Figure 1The pressure controller, servo controller and motor controller therein, and the controllers are respectively electrically connected to the electromagnetic switching valve 402, the servo valve 403, the pneumatic shut-off valve 404, the servo motor 300 and the standard pressure sensor 600; the standard pressure sensor 600 is used to detect the pressure in the sealed chamber and send the pressure data to the controller; the controller is used to compare the received pressure data with the pressure command, and control the spool of the servo valve 403 to displace according to the comparison result to realize the inflation and deflation of the sealed chamber, or control the servo motor 300 to rotate to drive the piston 203 to move linearly to realize the change of the volume of the sealed chamber. By comparing the received pressure data with the pressure command by the controller, and controlling the spool of the servo valve 403 to displace according to the comparison result to realize the inflation and deflation of the sealed chamber, or controlling the servo motor 300 to rotate to drive the piston 203 to move linearly to realize the change of the volume of the sealed chamber, thereby realizing the rapid adjustment of the pressure in the pressure chamber 200 by using the servo valve 403, or using the servo motor 300 to continuously compensate the pressure difference caused by temperature and gas leakage for a long time within a certain range.

[0055] In some embodiments, in the first stage, the servo motor 300 is kept stationary, the volume of the pressure chamber 200 remains unchanged, and the controller is used to send a displacement command to the servo valve 403 to adjust the displacement of the spool of the servo valve 403 to realize the inflation and deflation of the sealed chamber; in the second stage, the controller controls to close the electromagnetic switching valve 402, the servo valve 403 and the pneumatic shut-off valve 404, and sends a rotation command to the servo motor 300, and the servo motor 300 drives the piston 203 to move linearly along the inner wall of the cavity 202 through the transmission mechanism to realize the change of the volume of the sealed chamber, thereby compensating the pressure change in the pressure chamber 200 caused by reasons such as temperature and gas leakage in a small range, reducing the inflation and deflation frequency of the servo valve 403, preventing the servo valve 403 from generating condensation and icing phenomena during long-term operation, affecting the control stability of the system, increasing the service life of the whole device, and improving the control accuracy and stability of the device. In actual design, the servo motor 300 is also equipped with a motor driver 308, the controller sends a rotation command to the motor driver 308, the motor driver 308 drives the servo motor 300 to rotate according to the rotation command, and reads the rotary encoder of the servo motor 300 to form a closed-loop servo control of the position of the servo motor 300.

[0056] In some embodiments, a displacement sensor is installed inside the servo valve 403. The displacement sensor is used to collect and detect the displacement data of the spool in real time, and send the collected displacement data to the controller. The spool displacement signal is converted into an analog current signal that can be collected by a displacement sensor amplifier 405 and then enters the controller. The controller is used to send a displacement command to the servo valve 403 according to the displacement data, so as to realize the inflation and deflation of the sealed chamber. By collecting and detecting the displacement data of the spool in real time through the displacement sensor, and the controller sending a displacement command to the servo valve 403 according to the displacement data, the inflation and deflation of the sealed chamber are realized, and a high-precision servo control closed loop of the pressure of the servo valve 403 is achieved, ensuring the calibration accuracy and response speed during calibration measurement.

[0057] In some embodiments, the transmission mechanism includes a coupling 302, a ball screw 304, a nut 305 and a transmission piece 306. The coupling 302 is respectively connected to the servo motor 300 and the ball screw 304. The ball screw 304 is rotatably installed on the bottom plate 500. Both ends of the ball screw 304 are installed on the bottom plate 500 through a first bearing 303 and a second bearing 307. The nut 305 is threadedly connected to the ball screw 304. The transmission piece 306 is respectively connected to the nut 305 and the piston 203. By driving the ball screw 304 to rotate through the servo motor 300, the transmission piece 306 is restricted to move only in a straight line. Thus, the nut 305 moves linearly along the ball screw 304, driving the piston 203 to move linearly, realizing the change of the volume of the sealed chamber. The servo motor 300 is also equipped with a reducer 301. The reducer 301 is connected to the servo motor 300 to reduce the speed and increase the torque. The reducer 301 is connected to the ball screw 304 through the coupling 302.

[0058] In some embodiments, the length of the cavity is 60 mm, and the volume of the sealed chamber is variable with a maximum variable range of 80.6 mm 2 and a minimum of 70 mm 2 .

[0059] In some embodiments, the electromagnetic switch valve 402 is used to control the gas from the first pressure reducing valve 400 to enter the servo valve 403, acting as the switch of the device; the pneumatic shut-off valve 404 is used to close when powered off to maintain the gas pressure in the pressure chamber 200 after the servo valve 403 stops controlling. By controlling the gas from the first pressure reducing valve 400 to enter the servo valve 403 through the electromagnetic switch valve 402, acting as the switch of the device, it can let through gas after being powered on, and is used to control the on-off of the gas flow between the gas source and the servo valve 403; the initial state of the pneumatic shut-off valve 404 is to let through gas, and it is used to close when powered off to maintain the gas pressure in the pressure chamber 200 after the servo valve 403 stops controlling, which can avoid frequent start-stop of the system, increase the service life of the servo valve 403, and improve the control performance of the calibration system.

[0060] In some embodiments, the side wall of the cavity 202 is provided with a first connection hole, a second connection hole and a third connection hole. The first connection hole is used to connect the pneumatic shut-off valve 404 to realize the inflation and deflation of the sealed chamber. The first connection hole is located on the side of the cavity 202. The pneumatic shut-off valve 404 is connected to the first connection hole and is used to adjust the pressure value in the pressure chamber 200; the second connection hole is used to connect the standard pressure sensor 600 to realize the pressure measurement inside the sealed chamber. The second connection hole is located on the top surface of the cavity 202. The standard pressure sensor 600 is threadedly connected to the second connection hole to measure the pressure value in the pressure chamber 200 in real time; the third connection hole is used to connect the pressure sensor to be measured for pressure feedback. The third connection hole is located on the side of the cavity 202. The pressure sensor to be measured is threadedly connected to the third connection hole and is used to output the test pressure to the pressure sensor to be measured.

[0061] In some embodiments, the high-pressure gas pressure control and calibration device further includes a control box. The control box includes a box body 801, an upper cover 800 and an operation screen 802. The top of the box body 801 is open. The upper cover 800 is connected to the top opening of the box body 801. The bottom plate 500 is installed on the bottom surface of the box body 801 and is located inside the box body 801. The operation screen 802 is installed on the side of the box body 801 and is electrically connected to the controller to send a pressure command signal and a start-stop signal of the device to the controller. After the devices inside the control box start running, the collected sensor signals and abnormal alarm information are sent back to the operation screen 802, which is convenient for the operator to observe and use the calibration device. By installing each component on the bottom plate 500 and placing the bottom and the components thereon as a whole inside the box body 801, the integration of the device is further improved, the volume of the device can be reduced, and the components in the device can be protected; the control command is sent by using the operation screen 802, and the collected sensor signals are displayed on the screen, which is convenient for use and monitoring.

[0062] In some embodiments, a first mounting hole and a second mounting hole are provided on the side surface of the box body 801. The first mounting hole is for the air source input pipeline 100 to pass through, and the second mounting hole is for the pressure output pipeline 101 of the sealed chamber to pass through and connect to the pressure sensor to be measured.

[0063] The working principle of the high-pressure gas pressure control and calibration device in this embodiment is as follows: In the first stage, the servo motor 300 is powered on and remains stationary, and the volume of the pressure chamber 200 remains unchanged. The controller sends a displacement command to the servo valve 403, adjusts the spool displacement of the servo valve 403, controls the charging and discharging of gas in the pressure chamber 200, and realizes the high-precision servo control closed-loop of the pressure of the servo valve 403 to ensure the calibration accuracy and response speed during calibration measurement. In the second stage, the electromagnetic switch valve 402, the servo valve 403 and the pneumatic cut-off valve 404 are closed, and the pressure chamber 200 becomes a closed chamber. A rotation command is sent to the servo motor 300 to drive the piston 203 to move in the pressure chamber 200, thereby compensating for the pressure change in the pressure chamber 200 caused by reasons such as temperature and gas leakage in a small range, reducing the charging and discharging frequency of the servo valve 403, preventing the phenomenon of condensation and icing during the long-term operation of the servo valve 403 from affecting the control stability of the system, increasing the service life of the entire device, and improving the control accuracy and stability of the device.

[0064] The above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high-pressure gas pressure control and calibration device, characterized in that, It includes a bottom plate and a gas source, as well as a first pressure reducing valve, a second pressure reducing valve, an electromagnetic switch valve, a servo valve, a pneumatic control stop valve, a pressure chamber, a servo motor, a transmission mechanism and a standard pressure sensor installed on the bottom plate, where: The gas source is respectively connected to the first pressure reducing valve and the second pressure reducing valve; The second pressure reducing valve is connected to the power end of the pneumatic control stop valve, and is used to reduce the gas source pressure to the stable working pressure of the pneumatic control stop valve; The electromagnetic switch valve, the servo valve, the pneumatic control stop valve and the pressure chamber are sequentially connected through pipelines; The pressure chamber includes a cavity, an end cover and a piston. The cavity is connected to the pneumatic control stop valve through a pipeline, and the cavity is also used to connect to a pressure sensor to be measured; the end cover is hermetically connected to the cavity; the piston is movably and hermetically connected to the inner wall of the cavity, and is used to form a sealed chamber with the inner wall of the cavity; The standard pressure sensor is connected to the cavity; The transmission mechanism is respectively connected to the servo motor and the piston, and is used to drive the piston to move linearly under the drive of the servo motor, so as to realize the change of the volume of the sealed chamber.

2. The high-pressure gas pressure control and calibration device according to claim 1, characterized in that, It also includes a controller, and the controller is respectively electrically connected to the electromagnetic switch valve, the servo valve, the pneumatic control stop valve, the servo motor and the standard pressure sensor; the standard pressure sensor is used to detect the pressure in the sealed chamber and send the pressure data to the controller; the controller is used to compare the received pressure data with the pressure command, and control the spool of the servo valve to displace according to the comparison result to realize the inflation and deflation of the sealed chamber, or control the servo motor to rotate to drive the piston to move linearly to realize the change of the volume of the sealed chamber.

3. The high-pressure gas pressure control and calibration device according to claim 2, wherein In the first stage, the servo motor is kept stationary, and the controller is used to send a displacement command to the servo valve to realize the inflation and deflation of the sealed chamber; in the second stage, the controller controls to close the electromagnetic switch valve, the servo valve and the pneumatic control stop valve, and sends a rotation command to the servo motor. The servo motor drives the piston to move linearly along the inner wall of the cavity through the transmission mechanism to realize the change of the volume of the sealed chamber.

4. The high-pressure gas pressure control and calibration device according to claim 3, characterized in that, A displacement sensor is installed inside the servo valve. The displacement sensor is used to collect and detect the displacement data of the spool in real time, and send the collected displacement data to the controller; the controller is used to send a displacement command to the servo valve according to the displacement data to realize the inflation and deflation of the sealed chamber.

5. The high-pressure gas pressure control and calibration device according to claim 1, characterized in that The transmission mechanism includes a coupling, a ball screw, a nut and a transmission piece. The coupling is respectively connected to the servo motor and the ball screw. The ball screw is rotatably installed on the bottom plate. The nut is threadedly connected to the ball screw. The transmission piece is respectively connected to the nut and the piston.

6. The high-pressure gas pressure control and calibration device according to claim 1, characterized in that The volume of the sealed chamber varies in the range of 70 to 80.6 mm 2 .

7. The high-pressure gas pressure control and calibration device according to claim 1, characterized in that The electromagnetic switch valve is used to control the gas from the first pressure reducing valve to enter the servo valve, and functions as the switch of the device; the pneumatic control stop valve is used to close when powered off to keep the gas pressure in the pressure chamber after the servo valve stops controlling.

8. The high-pressure gas pressure control and calibration device according to claim 1, characterized in that, The side wall of the cavity is provided with a first connection hole, a second connection hole and a third connection hole. The first connection hole is used to connect the pneumatic control stop valve to realize the inflation and deflation of the sealed chamber; the second connection hole is used to connect the standard pressure sensor to realize the pressure measurement inside the sealed chamber; the third connection hole is used to connect the pressure sensor to be measured for pressure feedback.

9. The high-pressure gas pressure control and calibration device according to any one of claims 2-8, characterized in that It further includes a control box, which includes a box body, an upper cover and an operation screen. The top of the box body is open, the upper cover is connected to the top opening of the box body, the bottom plate is installed on the bottom surface of the box body and is located inside the box body, and the operation screen is installed on the side of the box body and is electrically connected to the controller to send a pressure command signal and a start-stop signal of the device to the controller.

10. The high-pressure gas pressure control and calibration device according to claim 9, characterized in that, The side of the box body is provided with a first installation hole and a second installation hole. The first installation hole is for the input pipeline of the gas source to pass through, and the second installation hole is for the pressure output pipeline of the sealed chamber to pass through to connect the pressure sensor to be measured.

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