Low-pressure self-flameout restart miniature solid attitude and orbit control engine

Abstract

The invention provides a low-pressure self-flameout restart miniature solid attitude and orbit control engine. An attitude control side and an orbit control side are connected through a thread structure and do not communicate with each other; an opening of the attitude control gas cylinder is fixedly connected with an attitude control end cover; the attitude control spray pipes and the electromagnetic valves are linearly arranged to form attitude control electromagnetic valve-spray pipe assemblies, and the six attitude control electromagnetic valve-spray pipe assemblies are arranged in a shape like a Chinese character'zhong '; a heat insulation layer is arranged on the inner wall of the rail control combustion chamber, and charges are arranged in the rail control combustion chamber; the orbit control end cover is an ellipsoidal end cover, and the middle of the orbit control end cover sinks inwards; the rail control spraying pipes and the floating lifting valves form assemblies, the four assemblies are orthogonally arranged in a cross shape, and the corresponding rail control electromagnetic valve assemblies are arranged in the same plane and form included angles with the central axes of the rail control spraying pipes. The invention provides a solid attitude and orbit control engine structure scheme which is small in size and light in weight, and through a low-pressure self-flameout technology and an attitude control and orbit control system decoupling design, the problems that a miniature solid attitude and orbit control engine is difficult to start for multiple times and the working time is too short are solved.

Description

Technical Field

[0001] The present invention proposes a low-pressure self-extinguishing and restartable micro solid attitude and orbit control engine, which can achieve the requirements of light weight, small size, multiple starts and long-term operation of the attitude and orbit control engine through low-pressure self-extinguishing technology. It mainly provides power for the attitude and orbit control of multi-target kinetic interceptors and belongs to the field of engine technology. Background Art

[0002] The attitude and orbit control system is an important component of the kinetic interceptor. Kinetic interceptors are a type of kinetic weapon that completely disables the enemy's warhead through the high heat generated at the moment of collision with the target aircraft. They are the preferred way to intercept incoming missiles and strike satellites in orbit. The design of the attitude and orbit control engine directly determines the overall size and weight envelope of the kinetic interceptor system. The liquid attitude and orbit control system has the characteristics of high thrust, high specific impulse, and easy control. It is mainly used in land-based anti-missile weapons. The solid attitude and orbit control system has the characteristics of simple structure, easy storage, and fast startup. It is mainly used in air-based and sea-based anti-missile weapons and is the main development direction in the future.

[0003] Traditional kinetic interceptors can only intercept one target at a time, with a low interception success rate, and cannot effectively deal with enemy threat clouds (including decoy targets). Therefore, the multi-target interceptor plan, in which an interceptor missile carries dozens of interceptors, came into being. With the introduction of the concept of multi-target kinetic interceptors, new requirements have been put forward for the performance of solid attitude and orbit control systems, mainly including the core requirements of light weight, small size, multiple starts, and long-term operation.

[0004] The technical core of the multi-target interceptor program is the development of a miniature interceptor. The mass of a single kill interceptor is required to be 2-10kg, with a diameter of 150-200mm and a length of 250mm. Based on this, the mass of the miniaturized attitude and orbit control system is required to be 1-6kg. However, the current attitude and orbit control system in China is limited by the development of shell materials, valve technology, processing technology and other technologies, and it is difficult to meet the new requirements of such a light-weight and small-sized engine.

[0005] In addition, it is difficult to achieve controllable shutdown and restart of existing solid propellants, resulting in the problem that once ignited, solid rocket engines must burn out all the propellants before they can stop working. In the application of solid attitude and orbit control systems, in order to achieve repeated starting of solid engines, a multi-pulse charging scheme is often used, and only one pulse of propellant is burned out at one ignition. However, this scheme produces pulse thrust, which has high requirements for the control algorithm.

[0006] Due to the limitation of mass and size, the charge of solid attitude and orbit control engine is limited, and the low burning rate solid propellant is difficult to prepare. The working time of current solid attitude and orbit control system is usually less than 10 0 ~10 1 s level, which is difficult to meet the needs of long-term work. Summary of the invention

[0007] Based on the above technical background, the present invention discloses a design scheme of a restartable micro solid attitude and orbit control engine with low pressure self-extinguishing, provides a structural scheme of a solid attitude and orbit control engine with small size and light weight, and solves the problems of difficulty in multiple starts and too short working time of the micro solid attitude and orbit control engine through low pressure self-extinguishing technology and decoupling design of attitude control and orbit control system. This scheme adopts the "orbit control combustion chamber-attitude control gas cylinder" structure to decouple attitude control from orbit control. The six nozzles on the attitude control side adopt nitrogen cold gas propulsion, and the nitrogen is produced by the reaction of sodium azide composite formula; the four nozzles on the orbit control side adopt gas propulsion, and the gas is produced by the combustion of solid charge that can be depressurized and extinguished. The attitude control nozzle adopts a direct-acting solenoid valve to realize switch control; the orbit control nozzle adopts a spring-assisted floating lift valve for switch control to reduce the valve mass, and is used in conjunction with the solenoid valve. The present invention also provides a solenoid valve structural scheme adopted by the attitude control and orbit control nozzles respectively to reduce the mass and size of the solenoid valve. The whole set of structural schemes can be used for the attitude and orbit control power system of multi-target interceptors.

[0008] The specific technical solution is:

[0009] The low-pressure self-extinguishing and restartable micro solid attitude and orbit control engine includes an attitude control side and an orbit control side, which decouple the attitude control from the orbit control; the attitude control side and the orbit control side are connected by a threaded structure and are not connected to each other;

[0010] The attitude control side includes: a spherical attitude control gas cylinder, an attitude control end cover, and an attitude control solenoid valve-nozzle assembly;

[0011] The opening of the attitude control gas cylinder is fixedly connected to the attitude control end cover, and the attitude control end cover is in the shape of a pipeline; a pipe joint is reserved on the outside of the attitude control end cover to facilitate cold air testing on the attitude control side.

[0012] The attitude control nozzle and the solenoid valve are arranged in a straight line to form an attitude control solenoid valve-nozzle assembly. There are a total of six attitude control solenoid valve-nozzle assemblies, arranged in a "Z" shape, and the attitude control solenoid valve-nozzle assembly and the attitude control end cover are connected by threads.

[0013] The track control side includes: track control end cover, track control combustion chamber, insulation layer, track control nozzle, floating lift valve and track control solenoid valve assembly;

[0014] The inner wall of the track-controlled combustion chamber is provided with a heat-insulating layer, and a charge is provided in the track-controlled combustion chamber;

[0015] The track control side igniter is installed from the track control end cover side;

[0016] The rail control end cover is an ellipsoidal end cover and is concave in the middle, forming an installation space for the rail control nozzle, floating lift valve, and rail control solenoid valve assembly.

[0017] The rail control end cover and the rail control combustion chamber are connected by threads. There are four cylindrical structures arranged orthogonally in a "cross" shape on the rail control end cover. The cylindrical structure is provided with an inner shaft for axial positioning and wire sealing.

[0018] The track-controlled nozzle and the floating lift valve form an assembly, and the four assemblies are arranged orthogonally in a "cross" shape. The corresponding track-controlled solenoid valve assembly is arranged at an angle to the central axis of the track-controlled nozzle in the same plane.

[0019] The assembly structure formed by the rail control nozzle and the floating lift valve is as follows: the floating lift valve and the spring are installed in the ceramic sleeve, and the ceramic sleeve is installed in the cylindrical structure of the rail control end cover; the rail control nozzle with a shoulder is installed on the outside of the floating lift valve, and the nozzle end cover with an internal thread is threadedly connected to the cylindrical structure of the rail control end cover with an external thread. While the rail control nozzle is compressed, line sealing is achieved through the raised structure on the rail control nozzle shoulder.

[0020] The rail control solenoid valve assembly is connected to the rail control end cover by threads, and the gas passage on the rail control end cover adopts a zirconium oxide ceramic sleeve for thermal protection.

[0021] The main structures of the track control combustion chamber and attitude control cylinder are made of TC titanium alloy; the propellant is made of low-temperature composite propellant, and the insulation layer is made of EPDM rubber.

[0022] The attitude control end cover and the nozzle of the attitude control solenoid valve-nozzle assembly are made of MA21 grade magnesium-lithium alloy material.

[0023] The ceramic sleeve of the rail control nozzle and floating lift valve assembly is made of zirconium oxide ceramic material, and the rail control nozzle and floating lift valve are made of silicon carbide ceramic.

[0024] The present invention can meet the requirements of the attitude and orbit control power system for multi-target interceptors, and solve the technical problems of "light weight, small size, restartability, and long time" of solid attitude and orbit control engines. The advantages are:

[0025] (1) Repeated ignition can be achieved using ordinary solid charges with a low pressure index. Compared with the multi-pulse charge design, this scheme can provide continuous thrust; compared with negative pressure index propellants and high-pressure self-extinguishing propellants, the propellants of this scheme are easier to obtain and more technically feasible.

[0026] (2) Small size and light weight. The structural envelope size of the attitude and orbit control power system can be within 150mm in diameter × 200mm in length, and the total system mass is less than 1.5kg.

[0027] (3) Can be on call for a long time, working time can reach 10 2 s level.

[0028] (4) Energy decoupling of attitude control cylinders and orbit control combustion chambers. Usually, the energy required for attitude control missions is much lower than that for orbit change missions. Cold air propulsion is used on the attitude control side to keep the cylinders at room temperature, eliminating the need for thermal protection, reducing material strength requirements, and greatly reducing the mass of the engine casing.

[0029] (5) Decoupling of the track control nozzle and the attitude control nozzle. Usually, the track control nozzle is used much less frequently than the attitude control nozzle. After the propellant is turned off, the attitude control nozzle can still work normally, which improves the response speed of attitude control.

[0030] (6) The propellant only burns during the orbit change mission, and the thermal protection of the combustion chamber is easier than traditional solutions.

[0031] (7) The solenoid valve is lightweight and the weight of a single solenoid valve is less than 30g. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural schematic diagram of the present invention;

[0033] Figure 2 It is a schematic diagram of a partial cross-sectional structure of the present invention;

[0034] Figure 3 It is an overall cross-sectional view of the present invention;

[0035] Among them, 1-attitude control gas cylinder, 2-attitude control end cover, 3-attitude control solenoid valve-nozzle assembly, 4-track control combustion chamber, 5-insulation layer, 6-charge, 7-track control end cover, 8-track control solenoid valve assembly, 9-floating lift valve, 10-track control nozzle;

[0036] Figure 4 A half-section view of the layout of the attitude control nozzle and the direct-acting solenoid valve of the present invention;

[0037] Figure 5 It is a half-section view of the layout of the rail control nozzle and the secondary amplified gas valve of the present invention. DETAILED DESCRIPTION

[0038] The present invention aims to provide a design scheme for a solid attitude and orbit control engine with the characteristics of “light weight, small size, restartability and long duration”.

[0039] In order to meet the above requirements, the present invention adopts the "track control combustion chamber 4-attitude control cylinder 1" structure to decouple attitude control from track control;

[0040] The overall structure of the engine is as follows Figure 1 and Figure 2 As shown in the figure, the attitude control system is decoupled from the orbit control system, with six nozzles on the attitude control side and four nozzles on the orbit control side. Figure 3 shown.

[0041] The attitude control side includes: a spherical attitude control gas cylinder 1, an attitude control end cover 2, an attitude control solenoid valve-nozzle assembly 3, etc.;

[0042] The track control side includes: a track control end cover 7, a track control combustion chamber 4, an insulation layer 5, a track control nozzle 10, a floating lift valve 9 and a track control solenoid valve assembly 8, etc.

[0043] The attitude control and track control parts are connected by a threaded structure and are not connected to each other. The track control side igniter is installed from the track control end cover 7 side, and sufficient installation space has been reserved. The main structure of the track control combustion chamber 4 and the attitude control cylinder 1 is made of TC4 titanium alloy, and other metal parts with lower strength requirements are made of MA21 brand magnesium-lithium alloy. The solid propellant is a low-temperature composite, and the insulation layer 5 is made of EPDM rubber.

[0044] For the attitude control side design: In order to meet the strength requirements, the opening diameter of the attitude control cylinder 1 is as small as possible; in order to reduce redundant mass, the attitude control end cover 2 is designed almost in the shape of a pipeline. The attitude control cylinder 1 and the attitude control end cover 2 are connected by welding, and a pipe joint is reserved on the outside of the attitude control end cover 2 to facilitate the cold air test on the attitude control side.

[0045] Since the thrust of the attitude control side nozzle is very small, this scheme adopts a direct-acting solenoid valve to realize switch control, that is, the attitude control nozzle and the solenoid valve are arranged in a straight line to form an attitude control solenoid valve-nozzle assembly 3. There are a total of six attitude control solenoid valve-nozzle assemblies 3, arranged in a "Z" shape, and the attitude control solenoid valve-nozzle assembly 3 is threadedly connected to the attitude control end cover 2. The nozzle of the attitude control end cover 2 and the attitude control solenoid valve-nozzle assembly 3 is made of MA21 grade magnesium-lithium alloy material.

[0046] For the rail control side design: In order to reduce the weight as much as possible and achieve a compact axial layout, the rail control end cover 7 is designed to be recessed inward while ensuring strength on the basis of the ellipsoidal end cover, leaving space for the installation of the rail control nozzle 10, floating lift valve 9, and rail control solenoid valve assembly 8. Due to the special shape of the rail control end cover 7, 3D printing processing technology is required for preparation, and TC4 titanium alloy is used as the material. The rail control end cover 7 is connected to the rail control combustion chamber 4 by threads, and the inner shaft shoulder on the rail control end cover 7 is used for axial positioning and line sealing.

[0047] Since the thrust of the rail-controlled side nozzle is large, and the electromagnetic driving force of the lightweight solenoid valve is limited, this solution adopts a two-stage amplification form of the gas valve to achieve switch control, that is, the floating lift valve 9 is used in conjunction with the solenoid valve. The specific structure is: four rail-controlled nozzles 10-floating lift valve 9 components are arranged orthogonally in a "cross" shape, and the corresponding rail-controlled solenoid valve components 8 are arranged at a certain angle to the central axis of the rail-controlled nozzle 10 in the same plane.

[0048] The specific installation method of the rail control nozzle 10-floating lift valve 9 assembly is as follows: the floating lift valve 9 and the spring are placed in the ceramic sleeve, and then the ceramic sleeve is placed in the cylindrical structure of the rail control end cover 7, and then the rail control nozzle 10 with the shoulder is placed, and finally the nozzle end cover with internal threads is threadedly connected with the cylindrical structure of the rail control end cover 7 with external threads, and while the rail control nozzle 10 is pressed, the line seal is achieved through the convex structure on the shoulder of the rail control nozzle 10. The ceramic sleeve is made of zirconium oxide ceramic material, which plays a role in thermal protection, and the rail control nozzle 10 and the floating lift valve 9 are made of silicon carbide ceramic.

[0049] The rail control solenoid valve assembly 8 is connected to the rail control end cover 7 by threads, and the gas passage on the rail control end cover 7 is also thermally protected by a zirconium oxide ceramic sleeve.

[0050] Since traditional strength design is too conservative and it is difficult to meet the requirements of lightweight design for the engine, this scheme needs to introduce structural finite element simulation calculation in the design stage. The simulation results show that when the safety factor of this structural scheme is 1.5, the 3D printing wall thickness of the TC4 titanium alloy structure should be greater than 1.2mm, and the machined wall thickness should be greater than 0.7mm; the wall thickness of the structure using magnesium-lithium alloy should be greater than 1.2mm.

[0051] To meet quality requirements, the lightweight design of solenoid valves is also a key technology. Solenoid valves on the market usually have the following characteristics: strict sealing, long working time, copper wires, large working stroke, and corrosion resistance. However, the requirements of solid attitude and orbit control engines for solenoid valves are exactly the opposite: no strict sealing, extremely short working time, aluminum wires, small working stroke, and no corrosion resistance requirements. Therefore, it can significantly reduce weight and achieve overall index requirements.

[0052] Aluminum alloy can be used for the wire coil of the solenoid valve. The conductivity of aluminum alloy conductor is 61.2% of copper. The density of aluminum alloy is 2.7g / cm3 and the density of copper is 8.9g / cm3. Therefore, using aluminum alloy as the wire can reduce the weight of the coil. Considering that the coil does not need to work for a long time, aluminum alloy is selected as the material of the coil from the perspective of reducing weight. According to the national standard GB-T3955-2009 electrical round aluminum wire, the minimum diameter of the aluminum wire can reach 0.3mm.

[0053] According to the electromagnetic simulation results, the weight of the designed attitude control electromagnet core component is 22.5g, and the weight of the track control electromagnet core component is 18.1g. Finally, the parametric modeling results show that the mass of the designed track control solenoid valve is about 28g, and the mass of the designed attitude control solenoid valve is about 24g.

[0054] The attitude control adopts nitrogen cold air propulsion, and the nitrogen is produced by the reaction of sodium azide compound formula. The attitude control nozzle adopts direct-acting solenoid valve to realize switch control. The structural principle is as follows Figure 4 shown.

[0055] If attitude control is required, the working process is as follows: the direct-acting solenoid valve is energized, and the valve core moves away from the nozzle under the action of electromagnetic force, opening the nozzle and generating thrust; after the attitude control is completed, the solenoid valve is de-energized, and the valve core presses the nozzle under the action of spring force, closing the nozzle.

[0056] The track control adopts gas propulsion. The gas is generated by the combustion of solid charge 6. It can be extinguished and ignited multiple times. The track control nozzle 10 adopts a spring-assisted floating lift valve 9 for switch control and is used in conjunction with a solenoid valve. The structural principle is as follows Figure 5 shown.

[0057] If the track needs to be changed, the working process of the track control nozzle 10 is as follows:

[0058] (1) The igniter ignites to ignite the charge 6;

[0059] (2) The floating poppet valve 9 and the solenoid valve work together to open the nozzle, and the gas is discharged from the track control nozzle 10 to generate thrust;

[0060] (3) After completing the scheduled orbit change task, all orbit control nozzles 10 are opened, the orbit control combustion chamber 4 is depressurized, and the charge 6 is extinguished;

[0061] (4) Close all orbit control nozzles 10. If orbit change is required again, repeat steps (1) to (3). Use several solid igniters to meet the needs of several orbit changes.

[0062] Among them, the structural principle of the floating lift valve 9 and the solenoid valve is as follows Figure 5 As shown, the electromagnetic valve is used to control the movement of the enlarged floating lift valve 9, and then the floating lift valve 9 controls the nozzle switch, so that the rail control nozzle 10 can be opened and closed with a small electromagnetic force. The specific working process is as follows: (a) When the electromagnetic valve is powered off and closed, the gas is filled into the tail chamber of the valve core. At this time, the pressure of the tail chamber is the stagnation pressure, which is greater than the high-flow gas pressure of the valve head. The valve core is pushed due to the front and rear pressure difference and the spring assist, so that the nozzle is in a closed state; (b) When the electromagnetic valve is powered on and opened, the tail chamber of the valve core is connected to the external environment. At this time, the pressure of the tail chamber is the environmental pressure, which is less than the gas pressure of the valve head. The valve core is pushed due to the front and rear pressure difference, so that the nozzle is in an open state.

Claims

1. Low-pressure self-extinguishing and restartable micro solid attitude and orbit control engine, characterized in that: It includes an attitude control side and a track control side, which decouple the attitude control from the track control; the attitude control side and the track control side are connected by a threaded structure and are not connected to each other; The attitude control side comprises: a spherical attitude control gas cylinder (1), an attitude control end cover (2), and an attitude control solenoid valve-nozzle assembly (3); The opening of the attitude control gas bottle (1) is fixedly connected to the attitude control end cover (2), and the attitude control end cover (2) is in the shape of a pipeline; a pipe joint is reserved on the outside of the attitude control end cover (2) to facilitate cold air testing on the attitude control side; The attitude control nozzle and the electromagnetic valve are arranged in a straight line to form an attitude control electromagnetic valve-nozzle assembly (3); there are a total of six attitude control electromagnetic valve-nozzle assemblies (3), which are arranged in a "Z" shape, and the attitude control electromagnetic valve-nozzle assembly (3) and the attitude control end cover (2) are connected by threads; The track control side comprises: a track control end cover (7), a track control combustion chamber (4), a heat insulation layer (5), a track control nozzle (10), a floating lift valve (9) and a track control solenoid valve assembly (8); The inner wall of the track-controlled combustion chamber (4) is provided with a heat-insulating layer (5), and a charge (6) is provided in the track-controlled combustion chamber (4); The track control side igniter is installed from the track control end cover (7) side; The track control end cover (7) is an ellipsoidal end cover and is concave in the middle, forming an installation space for the track control nozzle (10), the floating lift valve (9), and the track control solenoid valve assembly (8); The track control end cover (7) and the track control combustion chamber (4) are connected by threads, and the track control end cover (7) has four cylindrical structures arranged orthogonally in a "cross" shape, and the cylindrical structure is provided with an inner shaft for axial positioning and line sealing; The track control nozzle (10) and the floating lift valve (9) form an assembly, and the four assemblies are arranged orthogonally in a "cross" shape. The corresponding track control solenoid valve assembly (8) is arranged in the same plane at an angle to the central axis of the track control nozzle (10), and the track control solenoid valve assembly (8) and the track control end cover (7) are connected by threads.

2. The low-pressure self-extinguishing restartable micro solid attitude and orbit control engine according to claim 1, characterized in that: The assembly structure formed by the rail control nozzle (10) and the floating lift valve (9) is as follows: the floating lift valve (9) and the spring are installed in a ceramic sleeve, and the ceramic sleeve is installed in the cylindrical structure of the rail control end cover (7); the rail control nozzle (10) with a shaft shoulder is installed on the outside of the floating lift valve (9), and the nozzle end cover with an internal thread is threadedly connected to the cylindrical structure of the rail control end cover (7) with an external thread. While the rail control nozzle (10) is pressed, a line seal is achieved through the protruding structure on the shaft shoulder of the rail control nozzle (10).

3. The low-pressure self-extinguishing restartable micro solid attitude and orbit control engine according to claim 1, characterized in that: The main structures of the track control combustion chamber (4) and the attitude control gas cylinder (1) are made of TC (4) titanium alloy; the charge (6) is made of low-temperature composite charge, and the insulation layer (5) is made of EPDM rubber; The attitude control end cover (2) and the nozzle of the attitude control solenoid valve-nozzle assembly (3) are made of MA21 grade magnesium-lithium alloy material; The ceramic sleeve of the track control nozzle (10) and the floating lift valve (9) assembly is made of zirconium oxide ceramic material, and the track control nozzle (10) and the floating lift valve (9) are made of silicon carbide ceramic.

4. The low-pressure self-extinguishing restartable micro solid attitude and orbit control engine according to claim 1, characterized in that: The gas passage on the rail control end cover (7) is thermally protected by a zirconium oxide ceramic sleeve.

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