Light-gas gun piston capable of testing missile-borne acceleration and pressure

Abstract

The utility model relates to a light-gas gun piston, in particular to a light-gas gun piston capable of testing missile-borne acceleration and pressure, and solves the technical problems that an existing light-gas gun piston acceleration and pressure measuring device is large in error and cannot acquire real-time speed. According to the utility model, the pressure sensor and the acceleration sensor are integrated in the piston shell, and the displacement and the acceleration process of the piston motion in the pump pipe and the pressure change parameters at the front end and the rear end are obtained by using data measured by the circuit assembly memory in a missile-borne storage and test mode, so that the structure is simple, the operation is simple and convenient; the experiment difficulty and the experiment cost are reduced; according to the shock-resistant piston, the piston shell, the compression screw cap, the shock-absorbing buffer material and the inner cavity form a two-layer shock-resistant protective structure, so that internal components can be protected, and the piston is ensured to have enough shock-resistant strength.

Description

Technical Field

[0001] The utility model relates to a light gas gun piston, in particular to a light gas gun piston capable of testing the acceleration and pressure of a projectile. Background Technique

[0002] The two-stage light gas gun is an important means for ultra-high-speed launching. The two-stage light gas gun generally consists of a driving source, a pump tube, a piston, an isolation diaphragm, a projectile, a high-pressure cone section, a launch tube, a target chamber, etc. The driving source part can use gunpowder, high-pressure gas, etc. The driving gas is used to push the piston, and the pre-charged light gas in the pump tube is compressed by the piston, and then the diaphragm is broken to push the projectile to launch.

[0003] During the rapid movement of the piston in the pump tube, the pre-charged light gas such as hydrogen or helium in the pump tube is compressed. During the compression process, the gas pressure at the front end of the piston rises rapidly. After reaching a certain pressure, the isolation diaphragm between the high-pressure cone section and the launch tube ruptures, pushing the projectile to accelerate. Since the initial acceleration of the projectile is slow, the piston still has a forward movement speed, and the gas pressure at the front end of the piston also shows a continuous increasing trend until the piston stops moving.

[0004] In the research of light gas gun launching technology, the internal ballistic test technology has always been the top priority. The traditional light gas gun internal ballistic test technology mainly includes laser interferometry Doppler velocimetry, wall pressure test, etc. For the test of the pressure change of the isolation diaphragm at the front end of the piston, the method of installing a pressure sensor by drilling holes at fixed points is generally used, and only the wall pressure change at a certain point is obtained, which still has a certain gap with the actual pressure at the end of the piston in the pump tube, and the real-time speed of the piston cannot be accurately obtained.

[0005] Therefore, it is necessary to provide a light gas gun piston capable of testing the acceleration and pressure of a projectile, so as to obtain the displacement and acceleration history of the piston movement and the pressure change parameters at the front and rear ends. Content of the Utility Model

[0006] The purpose of the utility model is to solve the technical problem that the existing acceleration and pressure measurement devices of the light gas gun piston have large errors and cannot obtain the real-time speed, and to provide a light gas gun piston capable of testing the acceleration and pressure of a projectile.

[0007] To achieve the above purpose, the technical scheme adopted by the utility model is as follows:

[0008] A light gas gun piston capable of testing the acceleration and pressure of a projectile, which is characterized in that it includes a piston housing, a recorder arranged in the piston housing, and a compression nut and a rear cover plate respectively installed at both ends of the piston housing;

[0009] The recorder includes an acceleration sensor installed on the rear cover plate, a built-in power supply and a connector installed on the compression screw cap, an inner cavity body, a circuit assembly arranged inside the inner cavity body, two front cover plates respectively installed at both ends of the inner cavity body, and two pressure sensors respectively installed on the two front cover plates;

[0010] The built-in power supply is connected to the power supply ends of the circuit assembly, the acceleration sensor, and the two pressure sensors. The output ends of the acceleration sensor and the two pressure sensors are respectively connected to the input ends of the circuit assembly. The control ends of the acceleration sensor, the two pressure sensors, and the communication end of the circuit assembly are respectively connected to the connector. The connector serves as an external interface for connecting to external devices.

[0011] Further, shock-absorbing and buffering materials are filled between the piston housing and the recorder, and between the inner cavity body and the circuit assembly.

[0012] Further, the built-in power supply includes an impact-resistant battery and a secondary power supply connected to each other;

[0013] The secondary power supply includes a multi-point parallel capacitor energy storage matrix formed by N groups of energy storage capacitors and isolation diodes, where N is an integer and N≥5.

[0014] Further, the pressure sensor adopts a high-frequency ballistic pressure test sensor with a piezoelectric structure, and the high-frequency ballistic pressure test sensor is composed of a sensitive element and a diaphragm with an integral ceramic coating.

[0015] Further, the acceleration sensor adopts a piezoresistive structure.

[0016] Further, the circuit assembly includes an external interface circuit, a communication circuit, a power management circuit, a low-pass filter circuit, a sensor signal conditioning circuit, an ARM processor, and a FLASH memory;

[0017] The input end and the control output end of the power management circuit are respectively connected to the built-in power supply 9, and the output ends are respectively connected to the power supply ends of the communication circuit and the low-pass filter circuit. The control input ends are respectively connected to the feedback ends of the communication circuit and the low-pass filter circuit;

[0018] The low-pass filter circuit, the sensor signal conditioning circuit, and the ARM processor are connected in sequence. The input end of the low-pass filter circuit is connected to the output ends of the two acceleration sensors and the pressure sensors. The read-write ends of the ARM processor are respectively connected to the read-write ends of the external interface circuit and the FLASH memory;

[0019] The communication circuit is connected to the external interface circuit, and the communication end of the external interface circuit is connected to the connector.

[0020] Further, the ARM processor and the FLASH memory adopt SOP-8 package chips.

[0021] Further, the material of the piston housing is TC4; the material of the pressing screw cap is 35CrMnA or TiC4.

[0022] Further, the shock-absorbing and buffering material is a two-component microbubble material with a density less than 0.1 g / cm 3 ³.

[0023] Further, the connector adopts an RS485 communication circuit.

[0024] The beneficial effects of the present utility model compared with the prior art are as follows:

[0025] 1. A light gas gun piston capable of testing on-board acceleration and pressure provided by the present utility model integrates a pressure sensor and an acceleration sensor in the piston housing, and uses a circuit component to store the measured data. The displacement and acceleration history of the piston movement in the pump tube and the pressure change parameters at the front and rear ends are obtained through the on-board storage and testing method. The structure is simple and the operation is convenient, which can reduce the experimental difficulty and experimental cost;

[0026] 2. In a light gas gun piston capable of testing on-board acceleration and pressure provided by the present utility model, the pressure sensor is installed on the front cover plate, the acceleration sensor is installed on the rear cover plate, and the built-in power supply and the connector are pressed tightly by the pressing screw cap, and all can be easily disassembled and replaced;

[0027] 3. In a light gas gun piston capable of testing on-board acceleration and pressure provided by the present utility model, one end of the piston housing is in threaded cooperation with the pressing screw cap, and the recorder can be axially fixed tightly to ensure that under the action of a large axial overload, the axial displacement of the recorder is as small as possible to avoid the internal connection wires from being pulled off;

[0028] 4. In a light gas gun piston capable of testing on-board acceleration and pressure provided by the present utility model, the piston housing and the pressing screw cap, as well as the shock-absorbing and buffering material and the inner cavity form a two-layer anti-shock protection structure, which can protect the internal components and ensure that the piston has sufficient anti-shock strength;

[0029] 5. In a light gas gun piston capable of testing on-board acceleration and pressure provided by the present utility model, a shock-absorbing and buffering material is arranged between the piston housing and the recorder, which can prevent the recorder from generating obvious radial displacement when being subjected to a large impact;

[0030] 6. In the light gas gun piston capable of testing missile-borne acceleration and pressure provided by the present utility model, the built-in power supply includes a secondary power supply composed of a multi-point parallel capacitor energy storage matrix. The single pair of diodes and capacitors in the matrix can be independently charged and discharged. In case of impact failure of a certain device, only the discharge maintenance time of the energy storage matrix will be shortened, and it will not cause the output failure of the entire secondary power supply, with good safety performance.

[0031] 7. In the light gas gun piston capable of testing missile-borne acceleration and pressure provided by the present utility model, the ARM processor and the FLASH memory select SOP-8 package chips, which are more suitable for data processing and storage under high overload conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a schematic structural diagram of an embodiment of the present utility model;

[0033] Figure 2 is a circuit structure diagram of the circuit components in an embodiment of the present utility model;

[0034] The descriptions of the reference numerals in the drawings are as follows:

[0035] 1 - piston housing, 2 - compression screw cap, 3 - rear cover plate, 4 - inner cavity body, 5 - circuit components, 6 - acceleration sensor, 7 - pressure sensor, 8 - front cover plate, 9 - built-in power supply, 10 - connector. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] To make the objectives, advantages, and features of the present utility model clearer, the following further describes in detail a light gas gun piston capable of testing missile-borne acceleration and pressure proposed by the present utility model with reference to the accompanying drawings and specific embodiments.

[0037] A light gas gun piston capable of testing missile-borne acceleration and pressure, as Figure 1 shown, includes a piston housing 1, a recorder disposed in the piston housing 1, and a compression screw cap 2 and a rear cover plate 3 respectively installed at both ends of the piston housing 1. The compression screw cap 2 is in threaded fit with the piston housing 1, and shock-absorbing and buffering materials are filled between the recorder and the piston housing 1.

[0038] The recorder includes an acceleration sensor 6 installed on the rear cover plate 3, a connector 10 and a built-in power supply 9 installed on the compression screw cap 2, an inner cavity body 4, circuit components 5 disposed in the inner cavity body 4, two front cover plates 8 respectively installed at both ends of the inner cavity body 4, and two pressure sensors 7 respectively installed on the two front cover plates 8.

[0039] The built-in power supply 9 is connected to the power supply terminals of the circuit component 5, the acceleration sensor 6, and the two pressure sensors 7. The output terminals of the acceleration sensor 6 and the two pressure sensors 7 are respectively connected to the input terminals of the circuit component 5. The control terminal of the acceleration sensor 6, the control terminals of the two pressure sensors 7, and the communication terminal of the circuit component 5 are respectively connected to the connector 10. The connector 10 serves as an external interface for connecting to external devices.

[0040] The acceleration sensor 6 is used to measure the acceleration during the piston movement, and the pressure sensor 7 is used to measure the gas pressures borne by the front end and the rear end during the piston movement. The acceleration sensor 6 adopts a piezoresistive structure and is directly installed inside the piston housing 1 and rigidly fixed on the rear cover plate 3. The pressure sensor 7 adopts a high-frequency ballistic pressure test sensor with a piezoelectric structure. The high-frequency ballistic pressure test sensor consists of a sensitive element and a diaphragm with an integrated ceramic coating, and an integrated design scheme is adopted to improve the structural stability, greatly improving the measurement accuracy and reliability, and enabling the sensor to have a smaller transient thermal effect and a higher frequency response.

[0041] The recorder mainly operates powered by the built-in power supply 9. When the system is in standby mode, it needs to enter a low-power consumption mode, which can increase the operation time and extend the system working time. When on standby, the power supply of unnecessary circuit modules is cut off to achieve the purpose of reducing power consumption. The built-in power supply 9 includes an impact-resistant battery and a secondary power supply that are interconnected and are used to supply power to the entire system during the measurement process. The secondary power supply includes a multi-point parallel capacitor energy storage matrix formed by N groups of energy storage capacitors and isolation diodes, where N is an integer and N≥5. Under high-impact conditions, a stable and continuous power supply is the basis for the reliable operation of the circuit component. When selecting an impact-resistant battery for the built-in power supply 9 and designing the secondary power supply at the same time, it can effectively eliminate power jitter and power interruption phenomena. The secondary power supply is composed of multiple groups of large-capacity energy storage capacitors and isolation diodes, forming a multi-point parallel capacitor energy storage matrix. The single pair of diodes and energy storage capacitors in the matrix can be independently charged and discharged. If a certain device fails due to impact, it will only shorten the discharge maintenance time of the energy storage matrix, but will not cause the output failure of the entire secondary power supply. The total value C of the energy storage capacitors is calculated by the following formula:

[0042]

[0043] In the formula: U 0 is the total battery voltage (V); I 0 is the total current required by the system (mA); T is the piston movement time (ms); U 1 is the minimum voltage required for the system to operate normally (V).

[0044] Let U 0 = 10V, I 0 = 80mA, U1 = 7.4 V. Combining with the piston movement time, taking T = 3.2 ms, the calculated value of C is 99 μF. After adding a design margin and doubling the capacitance value, C = 220 μF is finally selected.

[0045] The connector 10 serves as an external interface. All operations on the recorder can be achieved through the connector 10. The main operations include: monitoring the power status of the built-in power supply 9; charging the built-in power supply 9 through a dedicated charger; erasing the data in the internal memory; reading the data in the internal memory; setting the working parameters (sampling rate, storage duration) of the recorder. To simplify the complexity of the circuit and increase the reliability of data transmission, the connector 10 adopts an RS485 communication circuit.

[0046] As Figure 2 shown, the circuit component 5 includes an external interface circuit, a communication circuit, a power management circuit, a low-pass filter circuit, a sensor signal conditioning circuit, an ARM processor, and a FLASH memory. The input terminal and the control output terminal of the power management circuit are respectively connected to the built-in power supply 9, and the output terminals are respectively connected to the power supply terminals of the communication circuit and the low-pass filter circuit. The control input terminals are respectively connected to the feedback terminals of the communication circuit and the low-pass filter circuit. The power management circuit adjusts the voltage output by the built-in power supply 9 according to the feedback signals of the communication circuit and the low-pass filter circuit. The low-pass filter circuit and the sensor signal conditioning circuit are sequentially connected to the ARM processor. The input terminal of the low-pass filter circuit is connected to the output terminals of two acceleration sensors 6 and a pressure sensor 7. The read / write terminals of the ARM processor are respectively connected to the read / write terminals of the external interface circuit and the FLASH memory. The control terminal of the communication circuit is connected to the control terminal of the external interface circuit, and the communication terminal of the external interface circuit is connected to the connector 10.

[0047] The circuit component 5 is controlled by an ARM processor to work. The ARM processor is the control core of the entire recorder, and its main functions include data acquisition, data storage, data reading, and timing control, etc. The ARM processor and the FLASH memory adopt SOP-8 packaged chips, which are more suitable for use under high-overload conditions.

[0048] To achieve the acquisition, storage, and playback of measurement signals, measures such as enhanced potting and designing a protective housing are adopted. For the mechanical structure, the key is to consider the stability and structural strength of the piston, which are solved by selecting structural materials and structural design; for the anti-high-overload ability of the electronic circuit, components with small volume and light weight that can resist high overload are used. Through comprehensive measures such as reducing the self-weight of the components, strengthening the structural strength, and having an effective buffer structure, the anti-impact ability of the piston is improved.

[0049] The piston adopts a two-layer anti-impact protection structure. The outer anti-impact protection structure includes a piston housing 1, a compression screw cap 2, and a rear cover plate 3. The inner anti-impact protection structure is mainly an inner cavity 4 and shock-absorbing and buffering materials. In other embodiments, to prevent the internal devices and structures of the piston from resonating under high-frequency vibration, the principle of reflection and attenuation of stress waves can also be used for mechanical filtering. Mechanical filter gaskets are provided between the components of the recorder. Mechanical filtering is divided into internal filtering and installation filtering of the device.

[0050] The material of the piston housing 1 is TC4, which has high structural strength and will not deform under large impact loads, thus protecting the internal components from the extrusion caused by structural deformation. The material of the compression screw cap 2 is 35CrMnA or TiC4, which can ensure sufficient stiffness and thread connection strength. The piston housing 1 plays a role of fixing and protecting the internal recorder through the tightening of the thread of the compression screw cap 2. One end of the piston housing 1 is in threaded fit with the compression screw cap 2, which can axially fasten the recorder to ensure that under large axial overload, the axial displacement of the recorder is as small as possible to avoid the internal connection wires from being pulled off. The shock-absorbing and buffering materials filled between the piston housing 1 and the recorder can prevent the recorder from having obvious radial displacement when being impacted greatly. To ensure that the piston has sufficient anti-impact strength and improve its anti-overload ability, shock-absorbing and buffering materials are also provided between the inner cavity 4 and the circuit component 5, and an integrated potting installation is adopted. The shock-absorbing and buffering materials are low-density two-component microbubble materials.

[0051] In this embodiment, the acceleration sensor 6, the pressure sensor 7, and the built-in power supply 9 all adopt a detachable design. When the accuracy of the sensor cannot meet the measurement requirements after repeated use, it can be easily replaced. Since the capacity of the built-in power supply 9 will decrease after repeated charging and discharging, it is also considered for easy replacement in the design. The acceleration sensor 6 is installed on the rear cover plate 3, the pressure sensor 7 is installed on the front cover plate 8, and the built-in power supply 9 and the connector 10 are pressed by the compression screw cap 2, and all can be easily disassembled and replaced.

[0052] Compared with the traditional piston test, the pressure sensor, the acceleration sensor and the piston body are integratedly designed, realizing the real-time capture of the interior ballistic parameters during the whole movement process of the piston. The test method is more effective, and the time history of the interior ballistic data obtained is more comprehensive; and a convenient detachable structural design is adopted, making it more convenient to replace the internal components of the piston.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present invention.

Claims

1. A light gas gun piston capable of testing projectile load acceleration and pressure, characterized in that: It comprises a piston housing (1), a recorder arranged in the piston housing (1), and a compression screw cover (2) and a rear cover plate (3) respectively mounted at two ends of the piston housing (1); The recorder comprises an acceleration sensor (6) mounted on a rear cover plate (3), a built-in power supply (9) and a connector (10) mounted on a compression screw cover (2), an inner cavity (4), a circuit component (5) arranged in the inner cavity (4), two front cover plates (8) respectively mounted at two ends of the inner cavity (4), and two pressure sensors (7) respectively mounted on the two front cover plates (8); The built-in power supply (9) is connected to the power supply ends of the circuit assembly (5), the acceleration sensor (6) and the two pressure sensors (7); the output ends of the acceleration sensor (6) and the two pressure sensors (7) are respectively connected to the input end of the circuit assembly (5); the control end of the acceleration sensor (6), the control ends of the two pressure sensors (7) and the communication end of the circuit assembly (5) are respectively connected to the connector (10); the connector (10) serves as an external interface for connecting to external devices.

2. A light gas gun piston capable of testing projectile load acceleration and pressure according to claim 1, characterized in that: Shock-absorbing and buffering materials are filled between the piston housing (1) and the recorder, and between the inner cavity (4) and the circuit component (5).

3. A light gas gun piston capable of testing projectile load acceleration and pressure according to claim 2, characterized in that: The built-in power source (9) comprises an impact-resistant battery and a secondary power source connected to each other; The secondary power supply includes a multi-point parallel capacitor energy storage matrix composed of N groups of energy storage capacitors and isolation diodes, wherein N is an integer and N≥5.

4. A light gas gun piston capable of testing projectile load acceleration and pressure according to claim 3, characterized in that: The pressure sensor (7) adopts a high-frequency ballistic pressure test sensor with a piezoelectric structure, and the high-frequency ballistic pressure test sensor is composed of a sensitive element and a diaphragm with an integrated ceramic coating.

5. A light gas gun piston capable of testing projectile load acceleration and pressure according to claim 4, characterized in that: The acceleration sensor (6) adopts a piezoresistive structure.

6. A light gas gun piston capable of testing projectile load acceleration and pressure according to any one of claims 2-5, characterized in that: The circuit assembly (5) includes an external interface circuit, a communication circuit, a power management circuit, a low-pass filter circuit, a sensor signal conditioning circuit, an ARM processor and a FLASH memory; The input end and the control output end of the power management circuit are respectively connected to the built-in power supply (9), the output end is respectively connected to the power supply end of the communication circuit and the low-pass filter circuit, and the control input end is respectively connected to the feedback end of the communication circuit and the low-pass filter circuit; The low-pass filter circuit and the sensor signal conditioning circuit are connected to the ARM processor in sequence, the input end of the low-pass filter circuit is connected to the output ends of the acceleration sensor (6) and the two pressure sensors (7), and the read-write end of the ARM processor is connected to the external interface circuit and the read-write end of the FLASH memory respectively; The communication circuit and the external interface circuit are connected to each other, and the communication end of the external interface circuit is connected to the connector (10).

7. A light gas gun piston capable of testing projectile load acceleration and pressure according to claim 6, characterized in that: The ARM processor and FLASH memory are packaged in SOP-8 chips.

8. The light gas gun piston capable of testing projectile load acceleration and pressure according to claim 7, characterized in that: The material of the piston housing (1) is TC4; The material of the compression screw cover (2) is 35CrMnA or TiC4.

9. A light gas gun piston capable of testing projectile load acceleration and pressure according to claim 8, characterized in that: The shock-absorbing and buffering material has a density less than 0.1 g / cm 3 Two-component microfoam material.

10. A light gas gun piston capable of testing projectile load acceleration and pressure according to claim 9, characterized in that: The connector (10) adopts an RS485 communication circuit.

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