Pressure generating device for quasi-dynamic calibration of impact wave pressure plastic pressure measuring diaphragm

Abstract

The invention relates to a pressure generating device for quasi-dynamic calibration of a shock wave pressure plastic pressure measuring diaphragm. Comprising an oil cylinder body, a piston assembly, a standard pressure sensor, a body fastening bolt, an upper backing ring, a lower backing ring, a diaphragm fixing device and a pressure generating device. The oil cylinder body is integrally composed of an upper small-diameter column body, a lower large-diameter column body and a flange flanging at the bottom of the large-diameter column body. The upper part of the small-diameter cylinder is connected with a piston assembly, a plurality of openings for mounting standard pressure sensors are axially and symmetrically formed in the bottom of the small-diameter cylinder, and the internal diameter of the small-diameter cylinder for mounting the standard pressure sensors is greater than the internal diameter of other parts of the small-diameter cylinder; the calibrated plastic pressure measuring diaphragm is assembled in the large-diameter cylinder of the oil cylinder body through the body fastening bolt, the upper backing ring and the lower backing ring; before the piston assembly is assembled, the diaphragm fixing device is connected with the lower backing ring, and the calibrated plastic pressure measuring diaphragm is not pre-deformed. According to the invention, quasi-dynamic calibration of the shock wave plastic pressure measuring diaphragm is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of pressure calibration, and in particular relates to a pressure-generating device for quasi-dynamic calibration of a shock wave pressure plastic pressure-measuring diaphragm. Background Art

[0002] With the development of high-energy ammunition, the assessment of damage power under special working conditions such as tunnels, closed / semi-closed cabins, etc. has become increasingly important. The propagation law of shock waves under special working conditions is complex. Conventional shock wave pressure testing methods based on pressure sensors have problems such as poor anti-interference ability, weak survivability, and poor adaptability under special working conditions. The shock wave pressure testing technology based on the principle of plastic deformation provides a new type of testing method for shock wave pressure testing under special working conditions that is easy to install, has strong anti-interference ability, and is cost-effective. It has broad application prospects. However, the scientificity and accuracy of the measurement value of the shock wave pressure plastic pressure measuring diaphragm are crucial in the actual engineering application of the shock wave pressure field. In order to ensure that the measurement value of the pressure measuring diaphragm is meaningful, it must be calibrated to obtain the corresponding relationship between the diaphragm deformation deflection / deformation volume and the shock wave pressure, and establish a tabulation model for the plastic pressure measuring diaphragm.

[0003] At present, the calibration methods of shock wave pressure plastic pressure measuring diaphragms mainly include field test calibration, static calibration, dynamic calibration, etc. Field test calibration is to calibrate the pressure measuring diaphragm by conducting tests at the explosion site. This method can directly obtain the corresponding relationship between the shock wave pressure and the deformation deflection / deformation volume of the diaphragm. However, this method has the problems of long data acquisition cycle and high test cost, so it is not suitable for large-scale calibration of plastic pressure measuring diaphragms, and is only suitable for verifying the accuracy of pressure measurement of plastic pressure measuring diaphragms. The static calibration method is to calibrate the shock wave pressure plastic pressure measuring diaphragm using a static pressure generator with a known value. However, a large amount of research experience shows that plastic sensitive elements have serious memory effects, so the use of static calibration methods will inevitably lead to static and dynamic differences, resulting in inaccurate measurement results. The dynamic calibration method is to calibrate the pressure system using a pressure source similar to step excitation, but the frequency characteristics of the shock wave pressure signal and the step signal are far different, and the dynamic response range of the sensitive element itself is also narrow. This method is also not suitable for the calibration of plastic pressure measuring elements. The quasi-dynamic calibration technology based on the pendulum / drop weight device uses a semi-sine pulse similar to the shock wave pressure to dynamically calibrate the plastic pressure measuring diaphragm. The quasi-dynamic calibration is between static calibration and dynamic calibration. The calibration pressure and the shock wave pressure have similar dynamic characteristics, so the dynamic response obtained is relatively close. Summary of the invention

[0004] The purpose of the present invention is to provide a pressure-generating device for quasi-dynamic calibration of a shock wave pressure plastic pressure measuring diaphragm, through which a semi-sine pressure excitation of 0.5MPa to 10MPa can be applied to the plastic pressure measuring diaphragm, thereby realizing quasi-dynamic calibration of the shock wave plastic pressure measuring diaphragm.

[0005] The technical solution to achieve the purpose of the present invention is: a pressure-generating device for quasi-dynamic calibration of a shock wave pressure plastic pressure measuring diaphragm, comprising a cylinder body, a piston assembly, a standard pressure sensor, a body fastening bolt, an upper gasket, a lower gasket, a diaphragm fixing device and a pressure generating device;

[0006] The oil cylinder body is composed of a small-diameter cylinder at the top, a large-diameter cylinder at the bottom and a flange at the bottom of the large-diameter cylinder; the upper part of the small-diameter cylinder is connected to the piston assembly, and the bottom of the small-diameter cylinder is axially symmetrically provided with a plurality of openings for installing a standard pressure sensor, and the inner diameter of the small-diameter cylinder for installing the standard pressure sensor is larger than the inner diameter of other parts of the small-diameter cylinder;

[0007] The calibrated plastic pressure measuring diaphragm is assembled in the large diameter column of the oil cylinder body through the body fastening bolts, upper gasket and lower gasket;

[0008] Before assembling the piston assembly, the diaphragm fixing device and the lower gasket are connected so that the calibrated plastic pressure measuring diaphragm does not undergo pre-deformation.

[0009] Furthermore, the piston assembly includes a piston rod and a piston body. The piston body and the small-diameter cylindrical body of the cylinder body are threadedly connected. The piston rod is used to transmit the semi-sinusoidal pressure generated by the pressure generating device to the liquid medium in the cylinder body.

[0010] Furthermore, the pressure generating device is a drop-hammer type pressure generating device or a pendulum type pressure generating device;

[0011] The drop-hammer pressure generating device is used to generate a pressure above 5 MPa, and the pendulum pressure generating device is used to generate a pressure below 5 MPa.

[0012] Furthermore, an upper O-type sealing gasket is arranged between the upper gasket ring and the oil cylinder body, and a lower O-type sealing gasket is arranged between the lower gasket ring and the calibrated plastic pressure measuring diaphragm.

[0013] Furthermore, the diaphragm fixing device is connected to the lower gasket through a gasket fastening screw.

[0014] Furthermore, there are multiple groups of upper gaskets and lower gaskets with different sizes and specifications, so as to match shock wave plastic pressure measuring diaphragms with different ranges.

[0015] Furthermore, a plurality of vent holes are evenly distributed circumferentially at the bottom of the flange of the oil cylinder body, and the vent holes connect the plastic diaphragm deformation area at the bottom of the oil cylinder with the outside world to prevent the resistance generated by the compressed air during the deformation of the diaphragm.

[0016] Furthermore, the flange of the oil cylinder body has connection holes evenly distributed around the circumference.

[0017] Furthermore, the material of the oil cylinder body, the upper gasket, the lower gasket and the diaphragm fixing device is 35CrMoSiA.

[0018] A method for calibrating a plastic pressure measuring diaphragm using the above-mentioned pressure generating device comprises the following steps:

[0019] Step (1): The standard pressure sensors are symmetrically installed on both sides of the cylinder body;

[0020] Step (2): Invert the oil cylinder body, and sequentially place the upper O-ring, the upper gasket, the lower O-ring, the calibrated plastic pressure measuring diaphragm, and the lower gasket into the oil cylinder body, and connect them with the body fastening bolts;

[0021] Step (3): installing the diaphragm fixing device;

[0022] Step (4): Place the oil cylinder body upright and inject the pressure transmission medium;

[0023] Step (5): Install the piston assembly;

[0024] Step (6): removing the diaphragm fixing device;

[0025] Step (7): fixing the installed oil cylinder on the drop weight pressure generating device or the pendulum weight pressure generating device;

[0026] Step (8): Start the pressure generating device, so that the hammer head has a set height, and then release the hammer head to hit the piston rod, the piston rod moves downward, and the pressure is transmitted to the standard pressure sensor and the calibrated plastic pressure measuring diaphragm through the pressure transmission medium. After the impact is completed, the pressure generating device catches the hammer head;

[0027] Step (9): record the signal of the standard pressure sensor, disassemble in reverse order of step (2), take out the calibrated plastic pressure measuring diaphragm, and measure and calculate the deformation deflection and deformation volume of the diaphragm;

[0028] Step (10): Adjust the hammer material and hammer height, conduct multiple tests, and complete quasi-dynamic calibration.

[0029] Compared with the prior art, the present invention has the following significant advantages:

[0030] The present invention solves the problem of quasi-dynamic calibration of plastic pressure measurement technology. A drop weight / pendulum pressure generating device is used to generate a semi-sine pressure pulse to perform quasi-dynamic calibration on the plastic element. The obtained dynamic response is close to that under actual working conditions, and the dynamic error of the plastic pressure measurement diaphragm can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a cross-sectional view of the pressure-generating cylinder of the present invention.

[0032] Figure 2 It is an assembly diagram of the pressure-generating oil cylinder of the present invention.

[0033] Figure 3 The figure is the overall assembly diagram of the quasi-dynamic calibration device for plastic pressure measurement; (a) is a drop-hammer type quasi-dynamic calibration device, and (b) is a pendulum type quasi-dynamic calibration device.

[0034] Figure 4 are quasi-dynamic calibration curves; (a) is the drop-weight calibration curve, and (b) is the pendulum calibration curve.

[0035] Figure 5 This is a physical picture of the pressure-generating oil cylinder of the present invention.

[0036] Description of reference numerals:

[0037] 1-piston rod, 2-piston body, 3-cylinder body, 4-standard pressure sensor, 5-body fastening bolt, 6-upper gasket, 7-lower gasket, 8-diaphragm fixing device, 9-vent, 10-overflow valve hole, 11-upper O-type sealing gasket, 12-lower O-type sealing gasket, 13-calibrated plastic pressure measuring diaphragm, 14-gasket fastening screw, 15-overflow valve, 16-drop hammer pressure generating device, 17-pendulum pressure generating device. DETAILED DESCRIPTION

[0038] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0039] The present invention provides a quasi-dynamic calibration device for a plastic pressure measuring diaphragm. The device is based on the principle of comparative calibration and generates a semi-sine pressure pulse of 0.5MPa to 10MPa through a drop weight / pendulum pressure generating device, thereby realizing quasi-dynamic calibration of the plastic pressure measuring diaphragm.

[0040] The present invention provides a pressure-generating device for quasi-dynamic calibration of a shock wave pressure plastic pressure measuring diaphragm, which includes a drop hammer / pendulum pressure generating device, a standard pressure sensor, a pressure-generating oil cylinder, and a precision piston assembly. The pressure-generating device is based on the principle of hydraulic calibration, and a pressure-generating oil cylinder is designed. The drop hammer / pendulum pressure generating device freely falls and hits the precision piston assembly on the pressure-generating oil cylinder, thereby generating a semi-sine pressure pulse of 0.5MPa to 10MPa. A high-precision pressure sensor is used to monitor the pressure change in the cylinder in real time to ensure that the applied pressure value is accurate and reliable. By comparing the deformation deflection / deformation volume generated by the plastic diaphragm under different semi-sine pressures, the quasi-dynamic calibration of the plastic pressure measuring diaphragm can be achieved.

[0041] like Figure 1-5As shown, a quasi-dynamic calibration device for a plastic pressure measuring diaphragm includes: a piston rod 1, a piston body 2, a cylinder body 3, a standard pressure sensor 4, a body fastening bolt 5, an upper gasket 6, a lower gasket 7, a diaphragm fixing device 8, a vent hole 9, a relief valve hole 10, an upper O-ring sealing gasket 11, and a lower O-ring sealing gasket 12; a calibrated plastic pressure measuring diaphragm 13, a gasket fastening screw 14, a relief valve 15, a drop hammer type pressure generating device 16, and a pendulum type pressure generating device 17.

[0042] The drop-hammer pressure generating device 16 and the pendulum pressure generating device 17 are pressure generating devices. The drop-hammer pressure generating device 16 is used to generate a pressure above 5 MPa, and the pendulum pressure generating device 17 is used to generate a pressure below 5 MPa; the piston rod 1 and the piston body 2 are used to transmit semi-sine pressure; the standard pressure sensor 4 is used to detect the pressure change in the cylinder; the upper gasket 6, the lower gasket 7, the upper O-ring sealing gasket 11, and the lower O-ring sealing gasket 12 are used to install the calibrated plastic pressure measuring diaphragm 13; the diaphragm fixing device 8 is used to fix the calibrated plastic pressure measuring diaphragm to ensure that the diaphragm does not deform during the installation process; the vent hole 9 ensures that the deformation area of ​​the diaphragm is connected to the outside world to prevent the resistance generated by the compressed air of the diaphragm.

[0043] The drop hammer type pressure generating device is used to generate a pressure above 5MPa, and the pendulum type pressure generating device is used to generate a pressure in the range of 0.5 to 5MPa; the drop hammer / pendulum type pressure generating device has an automatic hammer connection function to prevent the hammer head from falling due to gravity and causing a secondary impact on the pressure-generating cylinder, ensuring that the plastic pressure measuring diaphragm will not undergo secondary deformation; the hammer head of the drop hammer / pendulum is located directly above the precision piston assembly to ensure the consistency of pressure transmission.

[0044] The pulse pressure amplitude P generated by the pressure generating device m , which can be calculated by formula (1).

[0045]

[0046] Furthermore, by adjusting the hammer head material and swing angle of the pendulum / drop hammer / The falling height H, the initial volume V0 of the pressure-generating cylinder, and the piston rod diameter r of the piston assembly can obtain half-sine pressure pulses with different amplitudes and pulse widths.

[0047] The test method of the above quasi-dynamic calibration device mainly includes the following steps:

[0048] Step 1. Standard pressure sensors 4 are symmetrically installed on both sides of the cylinder body 3. Symmetrical installation of sensors can effectively balance the pressure distribution inside the cylinder, ensuring that the pressure value measured by each sensor can more truly reflect the actual working state in the cylinder.

[0049] Step 2, turn the oil cylinder body 3 upside down, put the upper O-ring 11, the upper gasket 6, the lower O-ring 12, the calibrated plastic pressure measuring diaphragm 13, and the lower gasket 7 into the oil cylinder body in this order, and connect them with fastening bolts to ensure that the subsequent pressure transmission medium does not leak;

[0050] Step 3, installing the diaphragm fixing device 8 to ensure that the calibrated plastic pressure measuring diaphragm 13 does not deform when the piston assembly is installed;

[0051] Step 4: Put the oil cylinder body 3 upright and inject the pressure medium. Common pressure mediums include mineral oil, vegetable oil, etc. Castor oil is recommended.

[0052] Step 5: Install the piston body 2 and the piston rod 1;

[0053] Step 6, dismantle the diaphragm fixing device 8 to ensure that the calibrated plastic pressure measuring diaphragm 13 has sufficient deformation space;

[0054] Step 7: Install the installed oil cylinder (such as Figure 2 As shown) is fixed to the drop weight pressure generating device 16 and the pendulum weight pressure generating device 17, as shown Figure 3 As shown;

[0055] Step 8, start the drop hammer / pendulum pressure generating device 16, 17, make the hammer head at a certain height / angle, then release the hammer head to hit the piston rod, the piston rod 1 moves downward, and transmits the pressure to the standard pressure sensor 4 and the calibrated plastic pressure measuring diaphragm 13 through the pressure transmission medium. After the impact is completed, the drop hammer / pendulum pressure generating device will catch the hammer head to prevent the second impact from causing errors in the calibration result;

[0056] Step 9, record the signal of the standard pressure sensor 4, disassemble the oil cylinder in the reverse order of step 2, take out the calibrated plastic pressure measuring diaphragm 13, and measure and record the deformation deflection / deformation volume of the diaphragm through various displacement and depth sensing systems;

[0057] Step 10: Adjust the hammer material, counterweight, hammer height / angle, and conduct multiple tests to complete the quasi-dynamic calibration process.

Claims

1. A pressure-generating device for quasi-dynamic calibration of a shock wave pressure plastic pressure measuring diaphragm, characterized in that: It comprises an oil cylinder body (3), a piston assembly, a standard pressure sensor (4), a body fastening bolt (5), an upper gasket (6), a lower gasket (7), a diaphragm fixing device (8) and a pressure generating device; The oil cylinder body (3) is composed of an upper small-diameter cylinder, a lower large-diameter cylinder and a flange at the bottom of the large-diameter cylinder; the upper part of the small-diameter cylinder is connected to the piston assembly, and the bottom of the small-diameter cylinder is axially symmetrically provided with a plurality of openings for installing a standard pressure sensor (4), and the inner diameter of the small-diameter cylinder for installing the standard pressure sensor is larger than the inner diameter of other parts of the small-diameter cylinder; The calibrated plastic pressure measuring diaphragm (13) is assembled in the large diameter column of the oil cylinder body through the body fastening bolts (5), the upper gasket (6) and the lower gasket (7); Before assembling the piston assembly, the diaphragm fixing device (8) and the lower gasket (7) are connected, and the calibrated plastic pressure measuring diaphragm (13) does not undergo pre-deformation.

2. The pressure-generating device according to claim 1, characterized in that: The piston assembly comprises a piston rod (1) and a piston body (2); the piston body (2) and a small-diameter cylindrical body of the oil cylinder body are threadedly connected; the piston rod (1) is used to transmit the semi-sine pressure generated by the pressure generating device to the liquid medium in the oil cylinder body.

3. The pressure-generating device according to claim 2, characterized in that: The pressure generating device is a drop-hammer type pressure generating device (16) or a pendulum type pressure generating device (17); The drop-hammer type pressure generating device (16) is used to generate a pressure above 5 MPa, and the pendulum type pressure generating device (17) is used to generate a pressure below 5 MPa.

4. The pressure-generating device according to claim 3, characterized in that: An upper O-type sealing gasket (11) is arranged between the upper gasket ring (6) and the oil cylinder body (3), and a lower O-type sealing gasket (12) is arranged between the lower gasket ring (7) and the calibrated plastic pressure measuring diaphragm (13).

5. The pressure-generating device according to claim 4, characterized in that: The diaphragm fixing device (8) is connected to the lower gasket (7) via a gasket fastening screw (14).

6. The pressure-generating device according to claim 5, characterized in that: There are multiple groups of upper gaskets and lower gaskets with different sizes and specifications, so as to match shock wave plastic pressure measuring diaphragms of different ranges.

7. The pressure-generating device according to claim 1, characterized in that: A plurality of vent holes (9) are evenly distributed in the circumferential direction at the bottom of the flange of the oil cylinder body. The vent holes connect the plastic diaphragm deformation area at the bottom of the oil cylinder with the outside world to prevent the resistance force generated by the compressed air during the deformation of the diaphragm.

8. The pressure-generating device according to claim 7, characterized in that: The flange of the cylinder body is provided with connection holes evenly distributed around the circumference.

9. The pressure-generating device according to claim 1, characterized in that: The material of the oil cylinder body (3), the upper gasket (6), the lower gasket (7) and the diaphragm fixing device (8) is 35CrMoSiA.

10. A method for calibrating a plastic pressure measuring diaphragm using the pressure generating device according to any one of claims 1 to 9, characterized in that: The steps include: Step (1): The standard pressure sensor (4) is symmetrically installed on both sides of the cylinder body (3); Step (2): Invert the oil cylinder body (3), and sequentially place the upper O-ring (11), the upper gasket (6), the lower O-ring (12), the calibrated plastic pressure measuring diaphragm (13), and the lower gasket (7) into the oil cylinder body (3), and connect them with the body fastening bolts (5); Step (3): installing the diaphragm fixing device (8); Step (4): the oil cylinder body (3) is placed upright and the pressure transmission medium is injected; Step (5): Install the piston assembly; Step (6): removing the diaphragm fixing device (8); Step (7): fixing the installed oil cylinder on the drop weight pressure generating device (16) or the pendulum weight pressure generating device (17); Step (8): start the pressure generating device, make the hammer head at a set height, then release the hammer head to hit the piston rod, the piston rod (1) moves downward, and transmits the pressure to the standard pressure sensor (4) and the calibrated plastic pressure measuring diaphragm (13) through the pressure transmission medium. After the impact is completed, the pressure generating device catches the hammer head; Step (9): record the signal of the standard pressure sensor (4), disassemble in reverse order of step (2), take out the calibrated plastic pressure measuring diaphragm (13), and measure and calculate the deformation deflection and deformation volume of the diaphragm; Step (10): Adjust the hammer material and hammer height, conduct multiple tests, and complete quasi-dynamic calibration.

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