Rocket type ignition device and forming method thereof

Abstract

The rocket type ignition device comprises a cover body assembly and a combustion chamber assembly, and the cover body assembly is arranged at a cavity opening of the combustion chamber assembly; the cover body assembly is composed of an outer cover shell, a heat insulation lining and an ignition powder containing structure. The combustion chamber assembly comprises a force bearing shell layer, an auxiliary heat insulation layer, a heat insulation protection layer and a reinforcing connection structure. The invention further provides a forming method of the rocket type ignition device. The forming method comprises the steps that firstly, the ablation-resistant ethylene propylene diene monomer material is prepared; step 2, pressing and sealing the end head, including the following processes of preheating, charging and pressing; step 3, preparing a force bearing shell layer, including preheating, forming and curing processes; step 4, compression molding: preheating, die filling and pressing processes are included; fifthly, the combustion chamber assembly is machined and bonded; step 6, dimension inspection; step 7, performing a hydrostatic test; and eighthly, hole milling is conducted. The problems of chip falling and burnthrough in the combustion chamber assembly are solved, and structural damage caused by fire spurting of a bonding interface is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of engine ignition devices, and particularly to a rocket-type ignition device and a forming method thereof. Background Art

[0002] Solid rocket motors are widely used in rockets, missiles, boosters, etc. The ignition device is a starting part of the solid rocket motor. Its function is to accurately and reliably ignite the main grain, so that the engine enters normal operation according to the predetermined requirements. It is extremely important and prone to failure. Among them, the ignition charge accommodating structural ignition device and the basket-type ignition device are the most commonly used. However, for larger engines, if the basket-type ignition device is used for ignition, excessive vibration and impact will be generated during ignition, and even deflagration may be caused, damaging the engine. Therefore, a rocket-type ignition device is adopted, which can safely and effectively ignite larger engines. Compared with other ignition devices, its ignition gas flow rate and combustion time can be strictly controlled, and the grain burns according to the predetermined law, without local high pressure and deflagration.

[0003] The rocket-type ignition device is actually a small solid rocket motor. It has a high working pressure, a large gas flow rate, and a short combustion time. The existing combustion chamber assembly shell of the rocket-type ignition device is made of glass fiber winding, and the tail is molded with a high-silica fiberglass bushing and then bonded to the shell. Since the shell is formed by fiber winding, the shell will leak laterally when the ignition working pressure is greater than 10 MPa, resulting in shell vibration and risks of local high pressure and deflagration. And there is only a high-silica fiberglass bushing at the tail inside the shell and it is bonded and formed, so there are risks of ablation such as block falling and burning through on the inner surface of the combustion chamber assembly shell during operation, and the tail bonding surface will generate flashover under high temperature and high pressure, resulting in its detachment. Therefore, a new rocket-type ignition device and a forming method thereof have become problems that need to be urgently solved by those skilled in the art. Summary of the Invention

[0004] The present invention provides a rocket-type ignition device, including: a cover body assembly and a combustion chamber assembly, and the cover body assembly is hermetically connected to the combustion chamber assembly; The cover body assembly is composed of an outer cover shell, a heat insulation lining layer and an ignition charge accommodating structure, and the ignition charge accommodating structure is embedded in one end of the outer cover shell through the heat insulation lining layer; The combustion chamber assembly is arranged as a multi-layer composite shell structure. The multi-layer composite shell structure includes a load-bearing shell layer. A strengthening connection structure is arranged on the outer surface of the load-bearing shell layer. An insulation protection layer is arranged on the inner wall of the load-bearing shell layer. An auxiliary heat insulation layer is also arranged on the outside of the load-bearing shell layer near one end of the outer cover shell; A closed end is installed at the end of the combustion chamber assembly. The closed end is arranged as a curved surface transition structure to reduce the air flow disturbance during the ignition process; The closed end is provided with at least three spray holes axially symmetrically distributed.

[0005] Optionally, the auxiliary heat insulation layer, the heat insulation protection layer and the heat insulation lining layer are all made of ablative-resistant ethylene propylene diene monomer (EPDM) rubber material.

[0006] Optionally, the load-bearing shell layer is formed by winding glass fiber, and the cross-sectional thickness of the load-bearing shell layer wound at the closed end thickens as the diameter of the closed end decreases.

[0007] A forming method of a rocket-type ignition device, including a process forming method of a combustion chamber assembly, and the specific steps are as follows: Step 1: Prepare ablative-resistant EPDM rubber material. Mix basic rubber, reinforcing components, flame retardant fillers, reinforcing fillers, processing aids, interfacial modifiers and vulcanizing agents in a predetermined proportion and refine them into ablative-resistant EPDM rubber material. Step 2: Prepare the heat insulation layer of the closed end, including the following preheating, loading and pressing processes, specifically as follows: A) Preheat the mold. Heat the forming mold of the closed end on a flat vulcanizing machine and then keep it warm. B) Load and close the mold. Wrap the ablative-resistant EPDM rubber material prepared in Step 1 on the surface of the female mold of the forming mold of the closed end, and then put it into a flat vulcanizing machine to close the mold to generate a closed mold material. C) Press and form. Press the closed mold material, and wait for the ablative-resistant EPDM rubber material to be demolded and wiped to form the heat insulation layer of the closed end. Step 3: Prepare the preform mold of the load-bearing shell layer, including preheating, forming and curing processes, specifically as follows: D) Preheat the mold. Heat the mold of the load-bearing shell layer on an oven and then keep it warm. E) Winding and forming. Chamfer the heat insulation layer of the closed end prepared in Step 2 and the lap joint of the closed end by 10 mm, brush adhesive at the chamfered part, bond the heat insulation layer and the closed end, then bond the bonded heat insulation layer and the closed end together again on the surface of the mold of the load-bearing shell layer, place a simulated closed end at the winding section of the mold of the load-bearing shell layer, then clamp the simulated closed end to a fiber winding machine for simulation, export the simulation program to the winding machine after confirming the simulation program for winding, and after winding is completed, cut and separate along the cross section, and remove the simulated closed end to form a simulated load-bearing shell layer. F) Curing and forming. Place the wound simulated load-bearing shell layer in an oven, raise the temperature from room temperature to 160°C - 180°C within 2 h - 3 h, keep it at 160°C - 180°C for 4 h - 6 h, and then naturally cool to room temperature and demold to form the preform mold of the load-bearing shell layer. Step 4: Prepare the load-bearing shell layer by molding, including preheating, mold loading, and pressing processes, which are specifically as follows: G) Preheat the mold. Place the preform mold of the load-bearing shell layer prepared in Step 3 on the press and heat it to 80°C for the first time, with a holding time of 1h - 2h; H) Load the material and close the mold. Wipe the release agent on the surfaces of the female mold and male mold of the preform mold of the load-bearing shell layer 2 - 3 times. Weigh an appropriate amount of high silica fiber / phenolic resin and fill it into the forming surface of the female mold. After filling, heat it for the second time and close the mold in the flat vulcanizing machine to form the secondary mold-closed material; I) Press molding. Place the secondary mold-closed material in the oven, heat it for the third time, and then naturally cool it to room temperature before demolding to form the load-bearing shell layer; Step 5: Machining and bonding of the combustion chamber assembly. Machine the outer surface dimensions of the load-bearing shell layer formed by mold closing in Step 4 according to the design drawings, and bond the strengthening connection structure and the heat insulation and protection layer to the shell respectively; Step 6: Inspection. Conduct dimensional inspection; Step 7: Testing. Conduct a hydrostatic test on the shell strength of the combustion chamber assembly that has passed the dimensional inspection in Step 6. The pressure range of the hydrostatic test is 12MPa - 14MPa; Step 8: Milling holes. After the test in Step 7 is qualified, mill the spray holes at the tail of the shell of the combustion chamber assembly.

[0008] Optionally, the ablative-resistant ethylene propylene diene monomer (EPDM) rubber material in Step 1 is composed of the following materials by mass percentage: reinforcing component 3% - 8%, flame retardant filler 13% - 20%, reinforcing filler 12% - 20%, processing aid 3.3% - 11%, interfacial modifier 3% - 8%, and vulcanizing agent 3% - 8%. The balance is basic rubber, and the sum of the mass percentages of each component is 100%; The basic rubber is ethylene propylene diene monomer (EPDM); The reinforcing component is fiber material; The flame retardant filler contains metal hydroxides; The reinforcing filler contains fumed silica; The processing aid contains one or a mixture of two of stearic acid and zinc hydroxide; The interfacial modifier contains silane coupling agent; The vulcanizing agent contains organic peroxides; Mix the above components in proportion, heat and calcine them, and then stir evenly to form the ablative-resistant ethylene propylene diene monomer (EPDM) rubber material.

[0009] Optionally, when preheating the mold of the closed end in Step 2 in the flat vulcanizing machine, heat it to 80°C, and the holding time is not less than 1h; When loading and closing the mold in the second step, the temperature in the flat vulcanizing machine is 160°C - 180°C, and the pressure holding time is 1h - 2h; The wiping material in the second step is ethyl acetate.

[0010] Optionally, when the fiber winding machine in the third step is operating, the winding tension is set to 30 - 50N, the yarn speed is 0.2m / s - 0.4m / s, the winding angle is 90°, the spiral winding angles are ±30° and ±60° alternately, and after setting, a simulation is carried out.

[0011] Optionally, in the fourth step, the temperature of the oven for the first heating rises to 80°C - 90°C in 1h, and the heat preservation time is 1h - 2h; The second heating is to rise to 110°C - 120°C in another 2h after the first heating, and the heat preservation time is 1h - 2h; The third heating is to rise in another 2h - 3h after the second heating, and the final temperature is controlled at 180°C - 200°C.

[0012] Optionally, in the fifth step, an epoxy adhesive is used for bonding, and after bonding, it is placed at room temperature for 24h - 48h to complete curing.

[0013] Optionally, in the sixth step, the dimensional inspection is to ultrasonically inspect the bonding interface and then perform a CT inspection on the quality of the interior of the composite material.

[0014] The beneficial effects of this application are as follows: 1. The present invention provides a multi-layer composite shell structure design and material innovation. By adopting a multi-layer composite structure of a load-bearing shell layer, a heat insulation and protection layer, and an auxiliary heat insulation layer, combined with the application of a burn-resistant ethylene propylene diene monomer (EPDM) rubber material, the structural strength and anti-burn performance of the ignition device are significantly improved. Among them, the load-bearing shell layer is formed by winding glass fibers, and at the closed end, through a gradient thickening design (the cross-sectional thickness thickens as the diameter decreases), the stress distribution is optimized, and the problem of easy cracking at the end of the traditional shell is solved. At the same time, the synergistic effect of multiple internal and external heat insulation materials (auxiliary heat insulation layer, heat insulation and protection layer, heat insulation lining layer) effectively blocks the thermal shock of high-temperature gas to the shell.

[0015] 2. The present invention provides a breakthrough in the integrated forming process of the closed end, and innovatively proposes a curved surface transition structure for the closed end and a molding process of ablative-resistant materials. By using ablative-resistant ethylene propylene diene monomer rubber with a specific ratio (including reinforcing fibers, metal hydroxide flame retardant fillers, and fumed silica reinforcing fillers), combined with a staged heating and pressing process (pressurizing and heat-preserving at 110°C - 120°C for 1 - 2 h), the dense forming of complex curved surface structures is achieved. Through chamfer bonding design and simulation winding program optimization, seamless connection between the closed end and the load-bearing shell layer is ensured, the interfacial bonding strength is improved, and the overall structural integrity is still maintained after the tail spray holes are milled, solving the technical bottleneck of easy leakage of traditional split ends.

[0016] 3. The present invention provides a collaborative optimization of fiber winding and curing processes. For the forming of the combustion chamber assembly, a glass fiber winding tension control (30 - 50 N), angle regulation (winding angle is 90°, and the spiral winding angles are ±30° and ±60° alternately), and curing process are developed. Through simulating the dynamic winding path planning of the closed end and combining the gradient curing in an oven (heating to 180°C - 200°C in 2 h and heat-preserving for 4 - 6 h), the porosity of the composite material is reduced and the interlaminar shear strength is increased. With the cooperation of a hydrostatic test (12 - 14 MPa) and ultrasonic / CT non-destructive testing technology, the pressure-bearing capacity of the shell is ensured, and the product reliability and batch consistency are significantly improved. Brief Description of the Drawings

[0017] Figure 1 It is a schematic structural diagram of the ignition shell of the rocket-type ignition device provided by the present invention; Figure 2 It is a forming method of the rocket-type ignition device provided by the present invention; In the figure: 1. Cover assembly; 2. Combustion chamber assembly; 3. Outer cover shell; 4. Heat insulation lining; 5. Ignition charge accommodation structure; 6. Load-bearing shell layer; 7. Auxiliary heat insulation layer; 8. Heat insulation and protection layer; 9. Strengthening connection structure; 10. Closed end. Detailed Embodiments

[0018] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0019] Embodiment 1: Please refer to Figure 1As shown in the figure, the rocket-type ignition device is prepared according to the following steps, including: a cover body assembly 1 and a combustion chamber assembly 2, and the cover body assembly 1 is hermetically connected to the combustion chamber assembly 2. Among them, the cover body assembly and the combustion chamber assembly can be connected by threads; The cover body assembly 1 consists of an outer casing 3, a heat insulation lining 4 and an ignition charge accommodating structure 5, and the ignition charge accommodating structure 5 is embedded in one end of the outer casing 3 through the heat insulation lining 4; The combustion chamber assembly 2 is arranged as a multi-layer composite shell structure. The multi-layer composite shell structure includes a load-bearing shell layer 6. A strengthening connection structure 9 is arranged on the outer surface of the load-bearing shell layer 6. An insulation and protection layer 8 is provided on the inner wall of the load-bearing shell layer 6. An auxiliary heat insulation layer 7 is also provided at one end of the outside of the load-bearing shell layer 6 close to the outer casing 3; The strengthening connection structure 9 is arranged on the outer surface of the load-bearing shell layer 6. The strengthening connection structure 9 is an annular kit and is installed on the middle part of the load-bearing shell layer 6 by interference fit; A closed end 10 is installed at the end of the combustion chamber assembly 2. The closed end 10 is arranged as a curved surface transition structure to reduce the airflow disturbance during ignition; The closed end 10 is provided with at least three axially symmetrically distributed spray holes, and the hole diameter is 4-12 mm.

[0020] The auxiliary heat insulation layer 7, the heat insulation and protection layer 8 and the heat insulation lining 4 are all made of ablative-resistant ethylene propylene diene monomer rubber material.

[0021] The load-bearing shell layer 6 is formed by winding glass fiber, and the load-bearing shell layer 6 winds two parts, namely a cylindrical shell and the closed end 10. The cross-sectional thickness of the load-bearing shell layer 6 wound at the closed end 10 thickens as the diameter of the closed end 10 decreases.

[0022] Among them, the outer diameter of the load-bearing shell layer 6 is 100 mm, the thickness of the cylinder section is 3 mm, the thickness of the closed end 10 is formed by natural accumulation during fiber winding and no mechanical processing is carried out, and the thickness of the cylinder section of the auxiliary heat insulation layer 7 is 2 mm.

[0023] The natural accumulation of the load-bearing shell layer 6 during fiber winding of the closed end 10 will cause the load-bearing shell layer 6 to form a thickness accumulation at the closed end 10. And when the cross-sectional diameter of the closed end 10 gradually decreases, the winding layer will gradually thicken, as Figure 1 shown, such winding optimizes the stress distribution and improves the load-bearing capacity of the load-bearing shell layer 6 for the end of the closed end 10.

[0024] Please refer to Figure 2As shown, the load-bearing shell layer 6 is formed by winding glass fiber, and the auxiliary heat-insulating layer 7 and the heat-insulating and protective layer 8 are made of ablative-resistant ethylene propylene diene monomer (EPDM) rubber material. The specific steps are as follows: Step 1: Prepare the ablative-resistant EPDM rubber material. The ablative-resistant EPDM rubber material is composed of, by weight percentage: stearic acid 3.4%, fiber 6%, zinc hydroxide 7%, coupling agent 3%, aluminum hydroxide 20%, dicumyl peroxide (DCP) 6%, white carbon black 17%, and the balance is EPDM rubber and inevitable impurities. All the materials are refined into ablative-resistant EPDM rubber material on an open mill according to the proportion. Step 2: Press the heat-insulating layer of the ablative-resistant EPDM rubber heat-insulating end 10, including the following preheating, loading, and pressing processes, specifically as follows: A) Preheat the mold. Heat the forming mold of the closed end 10 on a flat vulcanizing machine and then keep it warm. The flat vulcanizing machine is heated to 80 °C, and the holding time is 1.5 h. B) Load and close the mold. Wrap the ablative-resistant EPDM rubber material prepared in Step 1 on the surface of the female mold of the heat-insulating layer forming mold of the closed end 10, and then put it into the flat vulcanizing machine for closing the mold to form a closed mold material. C) Press and form. Press the closed mold material, and wait for the ablative-resistant EPDM rubber material to be demolded and wiped to form the heat-insulating layer of the closed end 10. The temperature of the flat vulcanizing machine in this step is 160 °C, and the pressure holding time is 1 h. Step 3: Prepare the preform mold of the load-bearing shell layer 6, including preheating, forming, and curing processes, specifically as follows: D) Preheat the mold. Heat the mold of the load-bearing shell layer 6 to 60 °C on an oven and then keep it warm for 3 h. E) Winding and forming. Chamfer the lap joint of the heat-insulating layer and the closed end 10 prepared in Step 2 by 10 mm, and brush the adhesive at the chamfered part. Bond the heat-insulating layer and the closed end 10, and then bond the bonded heat-insulating layer and the closed end 10 together on the surface of the mold of the load-bearing shell layer 6 again. Place the simulated closed end 10 at the winding section of the mold of the load-bearing shell layer 6, and then clamp the simulated closed end 10 onto a fiber winding machine for simulation. After confirming the simulation program, export the simulation program to the winding machine for winding. After the winding is completed, cut off the limit along the cross section of the simulated closed end 10 and remove the simulated closed end 10. Set the winding tension to 40 N, the yarn speed to 0.35 m / s, the winding angle to 90 °, and the spiral winding angles to alternate between ±30 ° and ±60 ° on the software and conduct simulation. After ensuring it is correct, export the winding program to the winding machine for winding. After the winding is completed, cut off the fiber along the end face of the simulated closed end 10 and remove the simulated closed end 10 to form the simulated load-bearing shell layer 6. After testing, the alternating winding angle design increases the circumferential strength by 35% and the axial strength by 22%.

[0025] F) Curing and forming: Place the wound simulated load-bearing shell layer 6 in an oven, raise the temperature from room temperature to 160°C within 2.5 h, maintain the temperature at 160°C for 4 h, and then naturally cool to room temperature and demold to form a preform mold of the load-bearing shell layer 6; Step 4: Prepare the load-bearing shell layer 6, including preheating, mold loading, and pressing processes, specifically as follows: G) Mold preheating: Place the preform mold of the load-bearing shell layer 6 prepared in Step 3 on a press and heat it for the first time to 80°C, with a holding time of 1.5 h; H) Loading and mold closing: Wipe the release agent on the surfaces of the female mold and male mold of the preform mold of the load-bearing shell layer 6 three times, weigh an appropriate amount of high-silica fiber / phenolic resin, fill it into the forming surface of the female mold of the preform mold of the load-bearing shell layer 6, and after loading, heat and close the mold for the second time in a flat vulcanizing machine to form a secondary mold-closed material, which is used to form the load-bearing shell layer 6. Among them, the second heating time is to raise the temperature to 110°C in 2 h and maintain the temperature for 1 h; I) Pressing and forming: Place the secondary mold-closed material in an oven for the third heating. The third heating is to raise the temperature to 190°C in 2 h based on the temperature after the second heating and insulation and maintain the temperature for 2 h, and then naturally cool to room temperature and demold to form the load-bearing shell layer 6; Step 5: Machining and bonding of the combustion chamber assembly 2: Machine the outer surface dimensions of the load-bearing shell layer 6 formed by mold closing in Step 4 according to the design drawing, bond the strengthening connection structure 9 and the heat insulation and protection layer 8 to the shell using epoxy adhesive respectively, and place it at room temperature for 30 h to cure and form; Step 6: Inspection: Conduct dimensional inspection, and use ultrasonic inspection to check the bonding interface and CT inspection to detect the internal quality of the composite material; Step 7: Test: Conduct a hydrostatic test on the shell strength of the combustion chamber assembly 2 that passes the dimensional inspection in Step 6, and the hydrostatic strength is 12 MPa; Step 8: Milling holes: After the test in Step 7 is qualified, mill the spray holes at the tail of the shell of the combustion chamber assembly 2, and the spray holes are 4 - 10 mm.

[0026] Example 2: Prepare a rocket ignition device according to the following steps. The outer diameter of the load-bearing shell layer 6 is 130 mm, the thickness of the cylinder section is 4 mm, the thickness of the closed end 10 is formed by natural accumulation during fiber winding and no machining is performed, and the thickness of the cylinder section of the auxiliary heat insulation layer 7 is 2.5 mm. The load-bearing shell layer 6 is formed by winding glass fiber, and the auxiliary heat insulation layer 7 uses an ablative-resistant ethylene propylene diene monomer ablative layer. The specific steps are as follows: Step 1: Prepare the ablative-resistant ethylene propylene diene monomer (EPDM) rubber material. The ablative-resistant EPDM rubber material is composed of the following components by weight percentage: stearic acid 3.6%, fiber 7%, zinc hydroxide 4%, coupling agent 5%, aluminum hydroxide 18%, dicumyl peroxide (DCP) 5%, white carbon black 20%, and the balance is EPDM rubber and inevitable impurities. All the materials are kneaded into the ablative-resistant EPDM rubber material on an open mill according to the proportion. Step 2: Prepare the thermal insulation layer of the closed end 10, including the following preheating, loading, and pressing processes, which are specifically as follows: A) Preheat the mold. Heat the forming mold of the closed end 10 on a flat vulcanizing machine and then keep it warm. The flat vulcanizing machine is heated to 80 °C, and the heat preservation time is 2 h. B) Load and close the mold. Wrap the ablative-resistant EPDM rubber material prepared in Step 1 on the surface of the female mold of the forming mold of the closed end 10, and then put it into the flat vulcanizing machine for closing the mold to form a closed-mold material. C) Press and form. Press the closed-mold material. After the ablative-resistant EPDM rubber material is demolded and wiped, a thermal insulation layer is formed. The temperature of the flat vulcanizing machine is 170 °C, and the pressure-holding time is 2 h. Step 3: Prepare the preform mold of the load-bearing shell layer 6, including the following preheating, forming, and curing processes, which are specifically as follows: D) Preheat the mold. Heat the mold of the load-bearing shell layer 6 on an oven to 60 °C and then keep it warm for 3.5 h. E) Winding and forming. Chamfer the lap joint of the thermal insulation layer and the closed end 10 prepared in Step 2 by 10 mm, and brush adhesive at the chamfered part. Bond the thermal insulation layer and the closed end 10, and then bond the bonded thermal insulation layer and the closed end 10 together again on the surface of the mold of the load-bearing shell layer 6. Place the simulated closed end 10 at the winding section of the mold of the load-bearing shell layer 6, and then clamp the simulated closed end 10 to a fiber winding machine for simulation. After confirming the simulation program, export the simulation program to the winding machine for winding. After winding, cut off the limit along the cross-section of the simulated closed end 10 and remove the simulated closed end 10; Set the winding tension to 40 N, the yarn speed to 0.35 m / s, the winding angle to 90 °, and the spiral winding angles to ±30 ° and ±60 ° alternately on the software and conduct simulation. After ensuring that there is no error, export the winding program to the winding machine for winding. After winding, cut off the fiber along the end face of the simulated closed end 10 and remove the simulated closed end 10 to form a simulated load-bearing shell layer 6.

[0027] F) Curing and forming. Place the wound simulated load-bearing shell layer 6 in an oven, raise the temperature from room temperature to 180 °C within 3 h, keep it at 180 °C for 5 h, and then naturally cool it to room temperature and demold it to form the preform mold of the load-bearing shell layer 6. Step 4: Prepare the load-bearing shell layer 6 by molding, including preheating, mold loading, and pressing processes, which are specifically as follows: G) Preheat the mold. Place the preform mold of the load-bearing shell layer 6 prepared in Step 3 on the press and heat it for the first time to 90°C, with a heat preservation time of 2 hours. H) Load the material and close the mold. Wipe the release agent on the surfaces of the female mold and male mold of the preform mold of the load-bearing shell layer 6 twice. Weigh an appropriate amount of high-silica fiber / phenolic resin and fill it into the forming surface of the female mold of the preform mold of the load-bearing shell layer 6. After loading, perform the second heating and close the mold in a flat vulcanizing machine to form a secondary mold-closed material. The time for the second heating is to increase the temperature to 120°C over 2 hours and keep it warm for 2 hours. The secondary mold-closed material is used to form the load-bearing shell layer 6. I) Press and form. Place the secondary mold-closed material in an oven for the third heating. The temperature of the third heating is increased to 200°C over 3 hours based on the temperature of the second heating and kept warm for 3 hours. Then, naturally cool it to room temperature and demold to form the load-bearing shell layer 6. Step 5: Machining and bonding of the combustion chamber assembly 2. Machine the outer surface dimensions of the load-bearing shell layer 6 formed by mold closing in Step 4 according to the design drawings. Bond the strengthening connection structure 9 and the heat insulation and protection layer 8 to the shell respectively using epoxy adhesive, and place it at room temperature for 35 hours to cure and form. Step 6: Inspection. Conduct dimensional inspection, and use ultrasonic inspection to check the bonding interface and CT detection to check the internal quality of the composite material. Step 7: Test. Conduct a hydrostatic test on the shell strength of the combustion chamber assembly 2 that has passed the dimensional inspection in Step 6, and the hydrostatic strength is 12 MPa. Step 8: Milling holes. After the test in Step 7 is qualified, mill the spray holes at the tail of the shell of the combustion chamber assembly. The spray holes are 4 - 10 mm.

[0028] The above are only several embodiments of the present application, and do not impose any form of limitation on the present application. Although the present application is disclosed above with preferred embodiments, it is not intended to limit the present application. Any person skilled in the art, without departing from the technical solution of the present application, makes some changes or modifications using the technical content disclosed above, which are all equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A rocket-type ignition device, characterized in that, Comprising: A cover assembly and a combustion chamber assembly, the cover assembly being hermetically connected to the combustion chamber assembly; The cover assembly is composed of an outer cover housing, a heat-insulating lining layer and an ignition charge accommodating structure, and the ignition charge accommodating structure is embedded at one end of the outer cover housing through the heat-insulating lining layer; The combustion chamber assembly is arranged as a multi-layer composite housing structure, the multi-layer composite housing structure includes a load-bearing housing layer, a strengthening connection structure is arranged on the outer surface of the load-bearing housing layer, a heat-insulating protection layer is provided on the inner wall of the load-bearing housing layer, and an auxiliary heat-insulating layer is further arranged on the outside of the load-bearing housing layer near one end of the outer cover housing; A closed end is installed at the end of the combustion chamber assembly, and the closed end is arranged as a curved surface transition structure to reduce the airflow disturbance during the ignition process; The closed end is provided with at least three axially symmetrically distributed spray holes.

2. The rocket ignition device according to claim 1, wherein, The auxiliary heat-insulating layer, the heat-insulating protection layer and the heat-insulating lining layer are all made of ablative-resistant ethylene propylene diene monomer rubber material.

3. A rocket-type ignition device according to claim 1, characterized in that, The load-bearing housing layer is formed by winding glass fiber, and the cross-sectional thickness of the load-bearing housing layer wound at the closed end is thickened as the diameter of the closed end decreases.

4. A forming method of a rocket-type ignition device according to any one of claims 1-3, characterized in that, A process forming method including a combustion chamber assembly, the specific steps are as follows: Step 1: Prepare ablative-resistant ethylene propylene diene monomer rubber material, and uniformly mix basic rubber, reinforcing components, flame retardant fillers, reinforcing fillers, processing aids, interfacial modifiers and vulcanizing agents in a predetermined ratio and refine them into ablative-resistant ethylene propylene diene monomer rubber material; Step 2: Prepare the heat-insulating layer of the closed end, which includes the following preheating, loading and pressing processes, specifically as follows: A) Preheat the mold, heat the forming mold of the closed end on a flat vulcanizing machine and then keep it warm; B) Load and close the mold, wrap the ablative-resistant ethylene propylene diene monomer rubber material prepared in the first step on the surface of the female mold of the forming mold of the closed end, then put it into a flat vulcanizing machine for closing the mold to generate a closed mold material; C) Press and form, press the closed mold material, and wait for the ablative-resistant ethylene propylene diene monomer rubber material to be demolded and wiped to form the heat-insulating layer of the closed end; Step 3: Prepare a preform mold for the load-bearing housing layer, which includes preheating, forming and curing processes, specifically as follows: D) Preheat the mold, heat the mold of the load-bearing housing layer on an oven and then keep it warm; E) Winding forming, chamfer the heat-insulating layer of the closed end prepared in the second step and the joint of the closed end by 10 mm, brush an adhesive at the chamfered part, bond the heat-insulating layer and the closed end, then bond the bonded heat-insulating layer and the closed end together again on the surface of the mold of the load-bearing housing layer, place a simulated closed end at the winding section of the mold of the load-bearing housing layer, then clamp the simulated closed end to a fiber winding machine for simulation, after confirming the simulation program, export the simulation program to the winding machine for winding, after the winding is completed, cut and separate along the cross section, and remove the simulated closed end to form a simulated load-bearing housing layer; F) Curing and forming: Place the wound simulated load-bearing shell layer in an oven, and raise the temperature from room temperature to 160°C - 180°C within 2h - 3h, then maintain the temperature at 160°C - 180°C for 4h - 6h, and then naturally cool to room temperature and demold to form a preform mold of the load-bearing shell layer; Step 4: Prepare the load-bearing shell layer, by compression molding, including preheating, mold loading and pressing processes, specifically as follows: G) Mold preheating: Place the preform mold of the load-bearing shell layer prepared in Step 3 on a press and heat it for the first time to 80°C, with a holding time of 1h - 2h; H) Loading and mold closing: Wipe the release agent on the female mold and male mold surfaces of the preform mold of the load-bearing shell layer 2 - 3 times, weigh an appropriate amount of high silica fiber / phenolic resin, fill it into the forming surface of the female mold of the preform mold of the load-bearing shell layer, and after loading, heat and close the mold for the second time in a flat vulcanizing machine to form a secondary mold-closed material, and the secondary mold-closed material is used to form the load-bearing shell layer; I) Pressing and forming: Place the secondary mold-closed material in an oven, heat it for the third time, and then naturally cool to room temperature and demold to form the load-bearing shell layer; Step 5, Machining and bonding of the combustion chamber assembly: Machine the outer surface dimensions of the load-bearing shell layer formed by mold closing in Step 4 according to the design drawings, and bond the strengthening connection structure and the heat insulation and protection layer to the shell respectively; Step 6, Inspection: Conduct dimensional inspection; Step 7, Test: Conduct a hydrostatic test on the shell strength of the combustion chamber assembly that has passed the dimensional inspection in Step 6, and the pressure range of the hydrostatic test is 12MPa - 14MPa; Step 8, Milling holes: After the test in Step 7 is qualified, mill the spray holes at the tail of the shell of the combustion chamber assembly.

5. A forming method of a rocket-type ignition device according to claim 4, characterized in that The ablative-resistant ethylene propylene diene monomer (EPDM) rubber material in Step 1 is composed of the following materials by mass percentage: reinforcing component 3% - 8%, flame retardant filler 13% - 20%, reinforcing filler 12% - 20%, processing aid 3.3% - 11%, interface modifier 3% - 8% and vulcanizing agent 3% - 8%, and the balance is basic rubber, and the sum of the mass percentages of each component is 100%; The basic rubber is ethylene propylene diene monomer (EPDM); The reinforcing component is a fiber material; The flame retardant filler includes metal hydroxides; The reinforcing filler includes fumed silica; The processing aid includes one or a mixture of two of stearic acid and zinc hydroxide; The interface modifier includes a silane coupling agent; The vulcanizing agent includes an organic peroxide; Mix the above components in proportion, heat and bake, and then stir evenly to form the ablative-resistant ethylene propylene diene monomer (EPDM) rubber material.

6. The forming method of a rocket-type ignition device according to claim 4, characterized in that, When preheating the mold of the forming mold of the closed end in Step 2 in a flat vulcanizing machine, heat it to 80°C, and the holding time is not less than 1h; When loading and closing the mold in Step 2, the temperature in the flat vulcanizing machine is 160°C - 180°C, and the pressure holding time is 1h - 2h; The wiping material in Step 2 is ethyl acetate.

7. A forming method of a rocket-type ignition device according to claim 4, characterized in that When the fiber winding machine in Step 3 is operating, set the winding tension to 30 - 50N, the yarn speed to 0.2m / s - 0.4m / s, the winding angle to 90°, and the spiral winding angles to alternate between ±30° and ±60°. After setting, conduct a simulation.

8. A forming method of a rocket ignition device according to claim 4, characterized in that In the fourth step, the temperature of the oven for the first heating rises to 80°C - 90°C in 1 hour, and the heat preservation time is 1 hour - 2 hours; The second heating is to rise to 110°C - 120°C in another 2 hours after the first heating, and the heat preservation time is 1 hour - 2 hours; The third heating is to rise in another 2 hours - 3 hours after the second heating, and the final temperature is controlled at 180°C - 200°C.

9. The forming method of a rocket-type ignition device according to claim 4, wherein In the fifth step, epoxy adhesive is used for bonding, and after the bonding is completed, it is placed at room temperature for 24 hours - 48 hours to complete curing.

10. The forming method of a rocket-type ignition device according to claim 4, characterized in that, The dimensional inspection in the sixth step is to inspect the bonding interface by ultrasonic wave and then detect the quality status inside the composite material by CT.

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