Insensitive ignition device for small-throat-diameter rocket engine

Abstract

The utility model discloses an insensitive ignition device for a small-throat-diameter rocket engine, which belongs to the field of initiating explosive insensitive ignition devices, and comprises a base, a basket net shell, a connecting sleeve, a main charge and an ignition assembly, the ignition assembly comprises an insensitive ignition tube, an anti-static mechanism and an electric connector, the base and the basket net shell are connected in a sealed mode through a connecting sleeve, the main charge is arranged in the basket net shell, one end of the insensitive ignition tube is arranged in the main charge, the other end of the insensitive ignition tube is connected with one end of a wire of the anti-static mechanism, and the other end of the wire extends out of the side face of the base and is connected with an electric connector. The basket net shell comprises a metal net cover, and net holes are sealed by coating a sealant solution on the metal net cover. According to the utility model, the propellant of the rocket engine can be quickly and reliably ignited, and the ignition device can be effectively prevented from generating larger combustion products or shell fragments of the ignition device during the working period of the rocket engine.

Description

Technical Field

[0001] The utility model relates to the field of insensitive ignition devices for pyrotechnics, in particular to an insensitive ignition device for a small-throat-diameter rocket engine. Background Art

[0002] For a rocket engine ignition device with a throat diameter less than φ10mm, it is required that no large combustion products or fragments of the ignition device housing are generated in a high-temperature and high-pressure working environment, otherwise it may cause the thrust curve to jump or even block the engine throat. This places high requirements on the ignition device, especially the housing of the ignition device.

[0003] Currently, in the industry, the housing of the ignition device generally uses ablative-resistant materials (such as high-silica glass fiber) or ablative materials (such as celluloid) to solve the problem. Among them, the housing made of ablative-resistant materials such as high-silica glass fiber has excellent high-temperature ablation resistance, but there is a risk of overall detachment after the steel ring at the connection part melts during engine operation; while the housing made of ablative materials such as celluloid has poor long-term storage performance and the material is prone to becoming brittle, resulting in unstable output performance of the ignition device. Summary of the Utility Model

[0004] The purpose of the utility model is to provide an insensitive ignition device for a small-throat-diameter rocket engine to solve the above problems.

[0005] To achieve the above purpose, the technical solution adopted by the utility model is as follows: An insensitive ignition device for a small-throat-diameter rocket engine includes a base, a wire mesh housing, a connecting sleeve, a main charge, and a firing assembly. Among them, the firing assembly includes an insensitive firing tube, an anti-static mechanism, and an electrical connector. The base and the wire mesh housing are hermetically connected through the connecting sleeve. The main charge is arranged inside the wire mesh housing. One end of the insensitive firing tube is arranged inside the main charge, and the other end is connected to one end of the wire of the anti-static mechanism. The other end of the wire extends out from the side of the base and is connected to the electrical connector. The wire mesh housing includes a metal mesh cover, and the mesh holes of the metal mesh cover are sealed by coating a sealing glue solution.

[0006] Among the above components, the base is used to protect the internal structure of the ignition device and fix the ignition device on the front head of the engine; the electrical connector is used to connect the firing assembly and the rocket power supply system to provide the starting detonation energy for the firing assembly; the firing assembly acts quickly after receiving the detonation energy, outputs a flame to ignite the main charge, and resists stray current, electrostatic discharge, etc. that may cause accidental firing of the ignition device when not receiving the detonation energy. Its integrated anti-static mechanism is designed in the base, and the wires of the electrical connector come out from the side of the base, ensuring that the anti-static mechanism will not fall off during the operation of the rocket engine to the greatest extent and avoiding adverse effects on the engine; the main charge burns quickly after receiving the flame output by the firing assembly to quickly ignite the propellant; the wire mesh shell can protect, support and seal the internal main charge, and resist the impact of the high-pressure gas generated by the main charge during the operation of the ignition device. While maintaining its own structural integrity, it allows the flame, hot solid particles and high-temperature and high-pressure gas generated by the main charge to pass through smoothly; after the ignition device completes its operation and the engine operates normally, it gradually melts by itself, forming tiny metal liquids that are ejected from the engine with the gas, ensuring that no large pieces of debris are generated.

[0007] As a preferred technical solution, two layers of sealant liquid are coated on the metal mesh cover, and a silk cloth (such as electric spun silk 11210) is arranged between the two layers of sealant liquid. Such a structure can make the above-mentioned effects of the wire mesh shell better.

[0008] As a preferred technical solution, the metal mesh cover is a hemispherical wire mesh with mesh holes of (3.5±0.2) mm×(0.8±0.1) mm. Too large mesh holes will cause some of the propellant to be flushed out of the charge cavity by high pressure before participating in combustion during ignition, resulting in loss of ignition energy; too small mesh holes will cause the high-temperature and high-pressure gas generated by the combustion of gunpowder during ignition to be unable to be discharged smoothly in time, resulting in too high instantaneous internal pressure in the charge cavity and causing the charge structure to fall off.

[0009] As a preferred technical solution, the anti-static mechanism further includes a printed circuit board, a gasket ring and an anti-static ring arranged in sequence; the printed circuit board has a discharge tip, the printed circuit board and the gasket ring are bonded to the anti-static ring through epoxy glue, and the gasket ring has a stepped structure to ensure that there is enough air gap between one side of the printed circuit board and the anti-static ring to form a safety channel for discharging static electricity.

[0010] As a preferred technical solution, the connecting sleeve is a steel sleeve.

[0011] Compared with the prior art, the advantages of the present utility model are as follows: on the premise of meeting safety and insensitivity requirements, the present utility model can not only quickly, reliably and stably output high-temperature flame to ignite the propellant of the rocket engine, but also effectively avoid the generation of large amounts of combustion products or fragments of the ignition device housing during the operation of the rocket engine. It is particularly suitable for small-throat solid rocket engines with a thrust fluctuation requirement of less than ±10%. Through experimental verification, the ignition peak pressure fluctuation of a certain type of solid rocket engine using this ignition device has decreased from 19% to 8%, and the internal pressure fluctuation in the working section has decreased from 13% to 6%. Description of the Drawings

[0012] Figure 1 It is the overall structure diagram of the present utility model.

[0013] In the figure: 1, insensitive ignition tube; 2, connecting sleeve; 3, compression screw; 4, printed circuit board; 5, gasket ring; 6, static discharge ring; 7, baffle; 8, base; 9, main charge; 10, wire mesh shell; 11, electrical connector. Detailed Embodiment

[0014] The present utility model will be further described below in conjunction with the drawings.

[0015] Embodiment:

[0016] Refer to Figure 1 , an insensitive ignition device for a small-throat rocket engine, comprising a base 8, a wire mesh shell 10, a connecting sleeve 2, a main charge 9 and a firing assembly. Among them, the firing assembly includes an insensitive ignition tube 1, an anti-static mechanism and an electrical connector 11. The base 8 and the wire mesh shell 10 are hermetically connected through the connecting sleeve 2. The main charge 9 is arranged inside the wire mesh shell 10. One end of the insensitive ignition tube 1 is arranged inside the main charge 9, and the other end is connected to one end of the wire of the anti-static mechanism. The other end of the wire extends out from the side of the base 8 and is connected to the electrical connector 11. The wire mesh shell 10 includes a metal mesh cover, and the mesh holes of the metal mesh cover are sealed by coating a sealing glue solution;

[0017] In this embodiment, the anti-static mechanism further includes a printed circuit board 4, a gasket ring 5 and a static discharge ring 6 arranged in sequence; the printed circuit board 4 has a discharge tip. The printed circuit board 4 and the gasket ring 5 are bonded to the static discharge ring 6 through epoxy glue. A baffle 7 is also arranged at the bottom of the static discharge ring 6. The baffle 7 is used to weld the metal wire shielding layer of the electrical connector 11 to ensure that the entire product forms an electromagnetic full shielding; the static discharge ring 6 and the baffle 7 are pressed tightly by a compression screw 3.

[0018] The manufacturing process of the basket net shell 10 of this embodiment can be: first brush a layer of sealant liquid on the metal mesh cover made of hemispherical steel wire mesh (the mesh size is 3.5±0.2mm×0.8±0.1mm) and solidify it, then cover it with a silk cloth (specification: electric spinning 11210), and then brush another layer of glue liquid, and use it after solidification; the sealant liquid is X98-11 acetal glue liquid produced by Sichuan Chongqing Three Gorges Paint Factory (the assembly process uses the original concentration);

[0019] The metal basket mesh with the above-mentioned special structure can resist the high-temperature ablation and high-pressure impact generated by the main charge when the ignition device is working, and the overall structure should remain intact and without damage after the ignition device is completed; during the operation of the engine, it will only gradually melt into metal droplets from the hemispherical head toward the steel ring, and will not produce large metal fragments to cause adverse effects on the engine.

[0020] The main charge of this embodiment is composed of three kinds of agents: magnesium / polytetrafluoroethylene ignition powder, boron / potassium nitrate ignition powder, and black powder, and the mass ratio of the three is 7:2:3.

[0021] The working principle and process are:

[0022] First, the basket shell 10 and the base 8 can support, protect and seal the internal structure, ignition components, main charge 9, etc.; the ignition components can resist and release interference and accidental ignition energy; when the initial detonation current is input into the ignition circuit, the insensitive ignition tube 1 receives the detonation electric energy and quickly acts to output flames, and the pyrotechnic agent in the main charge 9 acts quickly under the action of the flame, outputting high-temperature, high-pressure gas and flames and burning solid particles (the action time is determined by the proportion of the agents, and the output energy is determined by the total amount of the agents at the same proportion. This belongs to the general art The metal mesh cover is subjected to the high-temperature flame erosion generated by the main charge and the impact of high-pressure gas during the operation of the ignition device, and should remain intact and undamaged (the state of the metal mesh cover after the ignition device is operated is jointly determined by the amount of the main charge, the ratio of the charge, the thickness of the glue layer, and the specifications and material of the metal mesh cover). During the operation of the rocket engine, the ignition device is eroded and ablated by the high-temperature combustion gas, and the metal mesh cover of the basket net shell gradually melts from the hemispherical head toward the direction of the steel ring, forming a tiny metal liquid that is ejected from the engine along with the combustion gas.

[0023] This solution can ensure that the ignition device can reliably ignite the rocket engine propellant without generating large combustion products or ignition device casing fragments, thereby avoiding thrust fluctuations during the operation of a small-throat rocket engine.

[0024] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A desensitized ignition device for a small-throat rocket engine, characterized in that: It includes a base, a basket net shell, a connecting sleeve, a main charge and an ignition component, wherein the ignition component includes an insensitive ignition tube, an antistatic mechanism and an electrical connector, the base is closed and connected to the basket net shell by a connecting sleeve, the main charge is arranged in the basket net shell, one end of the insensitive ignition tube is arranged in the main charge, and the other end is connected to one end of the wire of the antistatic mechanism, the other end of the wire extends from the side of the base and is connected to the electrical connector, the basket net shell includes a metal mesh cover, and the mesh holes of the metal mesh cover are sealed by coating a sealing glue liquid.

2. The insensitive ignition device for a small-throat rocket engine according to claim 1, characterized in that: The metal mesh cover is coated with two layers of sealing glue liquid, and a silk cloth is arranged between the two layers of sealing glue liquid.

3. The insensitive ignition device for a small-throat rocket engine according to claim 1, characterized in that: The metal mesh cover is a hemispherical steel wire mesh with a mesh size of (3.5±0.2) mm×(0.8±0.1) mm.

4. The insensitive ignition device for a small-throat rocket engine according to claim 1, characterized in that: The anti-static mechanism also comprises a printed board, a gasket and a static discharge ring which are arranged in sequence; the printed board has a discharge tip, and the printed board is connected to the gasket.

5. The insensitive ignition device for a small-throat rocket engine according to claim 1, characterized in that: The connecting sleeve is a steel sleeve.

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