CN102778171B - Three-level light-gas gun driven by compressed nitrogen - Google Patents

Abstract

A three-stage light gas gun driven by compressed nitrogen, including a primary air chamber, a primary pump pipe, a secondary air chamber, a secondary pump pipe, a tertiary air chamber, and a launch tube; a primary air chamber and a primary pump The tubes are connected with a quick-opening valve between them; the primary pump tube is connected with the secondary air chamber; the secondary air chamber is connected with the secondary pump tube and a secondary diaphragm is set between the two; the secondary pump tube It is connected with the tertiary air chamber; the tertiary air chamber is connected with the launch tube and a tertiary diaphragm is arranged between the two. The invention adopts a three-stage drive mode to improve energy utilization efficiency between stages, improve the harsh gas environment in the cannon body, and reduce the risk of ablation of the cannon body; the secondary and tertiary air chambers adopt a straight cylinder structure or a large cone structure to improve The energy utilization efficiency is improved; the front end of the launch tube is designed with a replaceable ablation ring, which reduces the risk of ablation of the gun body itself, and greatly reduces the experimental cost of ultra-high-speed launch.

Description

A three-stage light gas cannon powered by compressed nitrogen

technical field

The invention relates to a three-stage light gas gun, in particular to a three-stage light gas gun driven by compressed nitrogen.

Background technique

Light gas cannons can launch projectiles of various materials and shapes to meet the needs of various end-point benefit simulation tests. They are known as the most general high-speed and ultra-high-speed drive technology and are widely used in research on the effects of kinetic energy weapons, geospace physics research, spacecraft Defense research and other fields. Compared with the first-level light gas gun and the second-level light gas gun, the third-level light gas gun adopts a three-level driving method.

McGill University in Canada has developed a three-stage light gas gun driven by gunpowder. The inner diameter of the launch tube is 12.7mm, which can accelerate 1.5g and 1.1g polyester cylindrical projectiles to 9.6km/s and 10.5km/s respectively. The University of Dayton Research Institute, an American research institute, has also developed a three-stage light gas gun driven by gunpowder. The inner diameter of the launch tube is 5.6mm, which can accelerate a nylon cylindrical projectile weighing 0.1g to 8.65km/s. (A.J.Piekutowski, K.L.Poormon. Development of a three-stage, light-gas gun at the University of Dayton Research Institute[J], International Journal of Impact Engineering, 33:615~624, 2006.). There is no other three-stage light gas gun in China.

Foreign three-stage light gas guns all use gunpowder as the driving source. The deflagration of gunpowder will produce a large amount of toxic gas, which will pollute the environment and endanger the health of operators; the deflagration of gunpowder will also produce a large amount of particulate matter such as carbon black, which remains in the barrel, increasing the difficulty of cleaning the barrel and reducing the efficiency of experiments; A kind of pyrotechnic product has certain potential safety hazards, and the cost of corresponding storage, management and other measures is also relatively high.

Contents of the invention

The object of the present invention is to provide a light gas cannon with high efficiency, low pollution, stable launch speed up to over 8km/s and low cost application under the launch speed exceeding 8km/s.

Technical solution of the present invention is:

A three-stage light gas cannon driven by compressed nitrogen is characterized in that it includes a primary air chamber, a primary pump pipe, a secondary air chamber, a secondary pump pipe, a tertiary air chamber, and a launch tube; The primary air chamber is connected to the primary pump pipe with a quick-open valve between them; the primary pump pipe is connected to the secondary air chamber; the secondary air chamber is connected to the secondary pump pipe and between the two A secondary diaphragm is arranged between them; the secondary pump pipe is connected to the tertiary air chamber; the tertiary air chamber is connected to the launch tube and a tertiary diaphragm is arranged between the two; the inlet of the primary pump pipe section is provided with a first-stage piston; the inlet section of the secondary pump tube is provided with a secondary piston; the inlet section of the launch tube is provided with projectiles; the inner diameter of the first-stage pump tube is greater than that of the secondary pump tube, and the second-stage pump tube The inner diameter of the pump tube is larger than the inner diameter of the launch tube; the first-stage air chamber is filled with high-pressure nitrogen; the first-stage pump pipe and the second-stage air chamber, and the second-stage pump pipe and the third-stage air chamber are filled with hydrogen.

The above-mentioned secondary air chamber adopts a straight cylinder structure, and the above-mentioned tertiary air chamber adopts a cone cylinder structure with a large cone angle.

The above-mentioned three-stage air chamber is a cone structure with a cone angle of 60°.

The pressure of high-pressure nitrogen in the first-stage air chamber is not greater than 30 MPa; the pressure of hydrogen in the first-stage pump pipe and the second-stage air chamber, the second-stage pump pipe and the third-stage air chamber is 0.1 MPa to 0.6 MPa.

The front end of the launch tube is provided with an ablation ring, and the ablation ring includes a disk, and the disk is sequentially provided with a concave stop, a diaphragm groove, a tapered groove and a convex stop along the center line of the disk from one end to the other end. The diameter of the concave stop is larger than the diameter of the diaphragm groove, and the diameter of the tapered groove gradually decreases from one end of the diaphragm groove. The maximum diameter of the tapered groove is smaller than the diameter of the diaphragm groove. The center of the convex stop Open a hole, the diameter of the central hole of the convex stop is equal to the minimum diameter of the tapered groove, the concave stop is suitable for the third-stage air chamber, the third-stage diaphragm is arranged in the diaphragm groove, and the convex stop It is compatible with the launch tube and the diameter of the central hole of the convex stop is equal to the inner diameter of the launch tube.

The ratio of the inner diameter of the first-stage pump tube to the inner diameter of the second-stage pump tube is 1.5-2.5, and the ratio of the inner diameter of the second-stage pump tube to the inner diameter of the launch tube is 3-5.

The ratio of the length to the inner diameter of the first-stage pump tube is 200-250, the ratio of the length to the inner diameter of the second-stage pump tube is 180-240, and the ratio of the length to the inner diameter of the launch tube is 250-600.

The beneficial effects of the present invention are:

1. The present invention uses compressed nitrogen instead of gunpowder as the driving source, which significantly improves the safety and environmental quality of the air cannon experiment, and can improve the efficiency of the air cannon experiment, which is conducive to the popularization and application of the air cannon experiment technology.

2. The present invention adopts a three-stage driving method, which can improve the energy utilization efficiency of the air cannon, reduce the risk of barrel ablation, and make the air cannon's stable firing speed exceed 8km/s under the premise of extremely low damage to the cannon body.

3. The secondary and tertiary air chambers of the device of the present invention adopt a straight cylinder structure or a large-angle cone structure, which can improve energy utilization efficiency.

4. The front end of the launch tube of the device of the present invention adopts an ablation ring that can be replaced in vitro to avoid ablation of the cannon body during ultra-high-speed launch. The operation is simple and convenient, and the experimental cost of ultra-high-speed launch is greatly reduced.

Description of drawings

Fig. 1 is a structural schematic diagram of a three-stage light gas gun driven by nitrogen;

Fig. 2 is a schematic diagram of the structure of the secondary air chamber;

Fig. 3 is a schematic diagram of the structure of a three-stage air chamber;

Fig. 4 is a schematic diagram of the structure of the ablation ring;

Figure 5 is the experimental waveform measured by the laser velocity measuring device, which is used to calculate the velocity of the projectile.

The reference signs are: 1-first-level air chamber; 2-first-level pump pipe; 3-secondary air chamber; 4-secondary pump pipe; 5-third-level air chamber; Valve; 8-first-level piston; 9-second-level diaphragm; 10-second-level piston; 11-third-level diaphragm; 12-ablation ring; - Diaphragm groove, 1204 - tapered groove, 1205 - protruding stop, 1206 - central hole of protruding stop.

Detailed ways

The basic process of firing the three-stage light gas cannon: high-pressure nitrogen gas is stored in the primary air chamber 1, and the high-pressure gas in the primary air chamber 1 is released instantly through the quick-opening valve 7 when launching, and the high-pressure gas drives the primary piston 8 to move, and the primary piston 8 moves. 8 Compress the gas in the primary pump tube 2 to the secondary air chamber 3 to a high pressure state, the secondary diaphragm 9 ruptures under a certain pressure, the gas in the primary pump tube 2 drives the secondary piston 10 to move, and the secondary piston 10 compresses the secondary The gas in the pump tube 4 reaches the tertiary air chamber 5 to a high pressure state, the tertiary diaphragm 11 ruptures under a certain pressure, the gas in the secondary pump tube 4 drives the projectile 13 to accelerate in the launch tube 6, and the projectile 13 accelerates to the target speed.

The present invention involves two key difficult problems:

(1) The problem of insufficient driving energy. The upper limit bullet speed of foreign advanced secondary gas guns is 8~11km/s, all of which use gunpowder as the driving source, while foreign compressed gas driven secondary light gas guns seldom have experimental data exceeding 6km/s, the main reason is the high pressure The energy density of compressed gas is not as good as that of gunpowder, and its driving ability cannot be compared with that of gunpowder. The present invention uses compressed nitrogen as a driving source, and it is necessary to pursue extreme energy utilization efficiency under limited driving energy in order to achieve an ultra-high launch speed exceeding 8 km/s.

(2) The problem of barrel ablation and projectile fragmentation. At higher firing speeds, an extremely harsh (high temperature, high pressure) gas environment appears in the barrel, which causes the barrel to ablate and the projectile to break, resulting in the failure of the launch experiment. The barrel ablation also greatly increases the experimental cost of ultra-high-speed launch. It is the main reason why there are few launch experiment data exceeding 7km/s in China except the present invention. In order for the present invention to achieve a stable firing speed exceeding 8km/s, and the present invention can also be applied at a low cost at a firing speed exceeding 8km/s, it is necessary to improve the extremely harsh gas environment in the gun barrel, and reduce the risk of gun barrel ablation, reduce Experimental cost of ultrafast launches.

The invention adopts a three-stage drive mode to improve energy utilization efficiency between stages, improve the harsh gas environment in the cannon body, and reduce the risk of ablation of the cannon body; the secondary and tertiary air chambers adopt a straight cylinder structure or a large cone structure to improve The energy utilization efficiency is improved; the front end of the launch tube is designed with a replaceable ablation ring, which reduces the risk of ablation of the gun body itself, and greatly reduces the experimental cost of ultra-high-speed launch.

The ratio of the inner diameter of the first-stage pump tube to the inner diameter of the second-stage pump tube is 1.5-2.5, and the ratio of the inner diameter of the second-stage pump tube to the inner diameter of the launch tube is 3-5. The ratio of the length of the first-stage pump tube to the inner diameter is 200-250, the ratio of the length of the second-stage pump tube to the inner diameter is 180-240, and the ratio of the length of the launch tube to the inner diameter is 250-600.

The volume of the first-stage air chamber of the three-stage air gun of the present invention is 0.01m ³ , the inner diameter of the first-stage pump tube is 57mm, and the length is 12m, the inner diameter of the second-stage pump tube is 37mm, and the length is 7.4m, and the inner diameter of the launch tube is 10mm, and the length is 12m. 4m, using a quick-opening valve to control the instant deflation of the first-stage air chamber.

Table 1 shows part of the firing test data of the 57/37/10mm three-stage light gas gun. The series of experiments in the table use cylindrical projectiles with a diameter of 10mm and the material is polycarbonate.

Table 1 57/37/10mm three-stage light gas cannon firing test data

Among them: the launch speed of experiment 2 reaches 8.09km/s.

Claims (6)

1. with the gas-powered three grades of light-gas guns of compressed nitrogen, it is characterized in that: comprise one-level air chamber, one-level pump line, secondary air chamber, secondary pump line, three grades of air chambers, transmitting tubes; Described one-level air chamber is connected with one-level pump line and quick opening valve is provided therebetween; Described one-level pump line is connected with secondary air chamber; Described secondary air chamber is connected with secondary pump line and secondary diaphragm is provided therebetween; Described secondary pump line is connected with three grades of air chambers; Described three grades of air chambers are connected with transmitting tube and three grades of diaphragms are provided therebetween; Described primary pump tube inlet section is provided with first stage piston; Described two stage pump tube inlet section is provided with second piston; Described transmitting tube entrance is provided with bullet; The internal diameter of described one-level pump line is greater than the internal diameter of secondary pump line, and the internal diameter of described secondary pump line is greater than the internal diameter of transmitting tube; High pressure nitrogen is filled with in described one-level air chamber; Hydrogen is filled with in described one-level pump line and secondary air chamber, secondary pump line and three grades of air chambers, the ratio of described primary pump length of tube and internal diameter is 200 ~ 250, the ratio of described two stage pump length of tube and internal diameter is 180 ~ 240, and described transmitting tube length and the ratio of internal diameter are 250 ~ 600.

2. according to claim 1 with the gas-powered three grades of light-gas guns of compressed nitrogen, it is characterized in that: described secondary air chamber adopts straight barrel type structure, and described three grades of air chambers adopt the cone barrel structure of large cone angle.

3. according to claim 2 with the gas-powered three grades of light-gas guns of compressed nitrogen, it is characterized in that: described three grades of air chambers are the cone barrel structure of 60 ° of cone angles.

4. according to claim 1 or 2 or 3 with the gas-powered three grades of light-gas guns of compressed nitrogen, it is characterized in that: the high pressure nitrogen pressure in described one-level air chamber is not more than 30MPa; Hydrogen Vapor Pressure in described one-level pump line and secondary air chamber, secondary pump line and three grades of air chambers is 0.1MPa ~ 0.6MPa.

5. according to claim 4 with the gas-powered three grades of light-gas guns of compressed nitrogen, it is characterized in that: described transmitting tube front end is provided with ablation ring, described ablation ring comprises disk, described disk passes through along disc centre line and is disposed with recessed seam, diaphragm groove, cone tank and male half coupling, the diameter of described recessed seam is greater than diaphragm groove, described cone tank is reduced diameter from diaphragm groove one end, the maximum gauge of described cone tank is less than the diameter of diaphragm groove, described male half coupling center is provided with male half coupling centre bore, described male half coupling center-hole diameter equals cone tank minimum diameter, described recessed seam and three grades of air chambers suitable, described three grades of diaphragm arrangement are in diaphragm groove, described male half coupling and transmitting tube is suitable and male half coupling center-hole diameter equals transmitting tube internal diameter.

6. according to claim 4 with the gas-powered three grades of light-gas guns of compressed nitrogen, it is characterized in that: the internal diameter of described one-level pump line and the ratio of two stage pump bore are 1.5 ~ 2.5, and the internal diameter of described secondary pump line and the ratio of transmitting tube internal diameter are 3 ~ 5.