Preparation method of heat insulation layer structure of solid rocket engine

Abstract

The invention provides a preparation method of a solid rocket engine heat insulation layer structure. The preparation method comprises the following steps that S1, a first heat insulation layer bottom layer prefabricated part is prefabricated through a mold pressing method; the outer side of the first heat insulation layer bottom layer prefabricated part is connected with a metal connector; s2, a second heat insulation layer bottom layer prefabricated part is prefabricated through a mold pressing method; s3, the first heat insulation layer bottom layer prefabricated part, the anti-ablation layer and the second heat insulation layer bottom layer prefabricated part are bonded, and then in a mold, a heat insulation layer bottom layer is prepared through an autoclave vulcanization technology; s4, forming a heat insulation layer cover layer prefabricated part by adopting an integral one-step vulcanization process; and S5, putting the heat insulation layer bottom layer prefabricated part and the heat insulation layer cover layer prefabricated part into a mold, and molding through an autoclave vulcanization process to obtain the solid rocket engine heat insulation layer structure. According to the heat insulation layer structure manufactured through the method, the thickness requirement of each heat insulation layer can be met, the size is accurate, and the product quality is remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of solid rocket engine manufacturing, and in particular relates to a method for preparing a solid rocket engine insulation layer structure. Background Art

[0002] When a rocket engine is working, the combustion chamber needs to withstand the scouring of high-temperature and high-pressure airflow above 3000℃, so it is necessary to set an insulation layer on the inner wall of the combustion chamber to protect the combustion chamber shell. At present, in order to further improve the anti-scouring performance of the insulation layer, an anti-ablation layer is set near the connection position of the insulation layer with the nozzle.

[0003] The forming methods of the thermal insulation layer of a solid rocket engine mainly include compression molding and manual patch molding. Chinese patent CN112223781A discloses a molding process for a thermal insulation bottom layer formed by manual patch molding. The surface quality of the manual patch molding product is poor, and defects such as pits, bulges, and air inclusions are prone to occur. It is easy to be eroded by hot air flow, thereby affecting the thermal protection performance.

[0004] The compression molding process has been widely used in the field of thermal insulation layer preparation. At present, due to strategic needs, the performance of different weapons and equipment is getting higher and higher, and higher and higher requirements are put forward for the engine. The engine structure is becoming more and more complex. The compression molding process is limited by the size and complexity of the thermal insulation layer. The traditional compression molding process can no longer meet the current thermal insulation layer molding needs. In order to prevent the anti-ablation layer from burning through when the engine is ignited, the anti-ablation layer needs to be wrapped in the thermal insulation layer, and the thickness and position of the ablation layer in the thermal insulation layer also need to be precisely controlled, because if the ablation layer is close to the inside or outside of the engine, it may burn to the anti-ablation layer in advance during ignition, causing the thermal insulation layer structure to be burned through. The current thermal insulation layer preparation method cannot guarantee the accuracy of the depth of the anti-ablation layer in the thermal insulation layer after molding, and the reliability of bonding. Secondly, the compression molding process is limited by the matching degree between the size of the thermal insulation layer and the size of the mold cavity. If the overflow channel is set unreasonably, the quality of the opening of the molded part cannot be guaranteed.

[0005] Therefore, it is necessary to provide a method for preparing a solid rocket engine insulation layer structure with excellent thermal protection performance. Summary of the invention

[0006] The technical problem solved by the present invention is to provide a method for preparing a solid rocket engine insulation layer structure, in order to solve the problem of poor thermal protection performance of the existing solid rocket engine insulation layer.

[0007] In order to solve the above problems, the present invention provides a method for preparing a thermal insulation layer structure of a solid rocket engine: The solid rocket motor insulation layer structure comprises: A first heat-insulating bottom layer, wherein the outer wall of the first heat-insulating bottom layer is suitable for connecting with the engine casing; A second heat-insulating layer bottom layer, wherein the second heat-insulating layer bottom layer is disposed on the inner side of the first heat-insulating layer bottom layer and connected to the first heat-insulating layer bottom layer; an anti-ablation layer, the anti-ablation layer being disposed between the first heat-insulating layer bottom layer and the second heat-insulating layer bottom layer and being located at one end of the first heat-insulating layer bottom layer connected to the nozzle; A heat-insulating layer cover layer, the heat-insulating layer cover layer is arranged on the inner side of the second heat-insulating layer bottom layer and connected to the second heat-insulating layer bottom layer; A metal joint, the metal joint is arranged on the outer side of the bottom layer of the first heat insulation layer and is located at one end of the bottom layer of the first heat insulation layer connected to the nozzle; The preparation method comprises the following steps: S1: prefabricate the first thermal insulation layer bottom layer by molding using a raw rubber sheet according to the selected thickness of the first thermal insulation layer bottom layer to obtain a first thermal insulation layer bottom layer prefabricated part; connect the outer side of the first thermal insulation layer bottom layer prefabricated part to a metal joint; S2: prefabricating the second heat insulation layer bottom layer by molding using a raw rubber sheet according to the selected thickness of the second heat insulation layer bottom layer to obtain a second heat insulation layer bottom layer prefabricated part; S3: bonding the first thermal insulation layer bottom preform, the anti-ablation layer, and the second thermal insulation layer bottom preform, and then preparing the thermal insulation layer bottom by a hot-press vulcanization process in a mold; S4: according to the selected thickness of the heat insulation layer cover layer, using the raw rubber sheet, adopting an overall one-step vulcanization process to form the heat insulation layer cover layer preform; S5: placing the preforms of the bottom layer and the cover layer of the thermal insulation layer in the mold, and molding them through a hot-press vulcanization process to obtain the thermal insulation layer structure of the solid rocket engine.

[0008] Preferably, a joint protection layer is further provided on the outer side of the metal joint, and the joint protection layer is connected to the metal joint.

[0009] Preferably, the first insulation layer bottom layer, the second insulation layer bottom layer and the insulation layer cover layer are made of insulation materials; the insulation material includes a filler and a matrix, the filler is at least one of asbestos and silica, and the matrix is ​​at least one of nitrile rubber, styrene-butadiene rubber, EPDM rubber and silicone rubber.

[0010] Preferably, in step S1, when the first insulation layer bottom layer is prefabricated by molding, the vulcanization temperature is 85-95° C. and the insulation time is 110-130 min; In step S2, when the second thermal insulation layer bottom layer is prefabricated by molding, the vulcanization temperature is 85-95° C. and the heat preservation time is 110-130 minutes; Preferably, in step S3, when the bottom layer of the thermal insulation layer is prepared by an autoclave vulcanization process, the vulcanization temperature is 145-155° C. and the insulation time is 110-130 min.

[0011] Preferably, in step S4, when the insulation layer cover is prepared by an autoclave vulcanization process, the vulcanization temperature is 85-95° C. and the insulation time is 110-130 min; In step S5, when the thermal insulation layer structure is prepared by an autoclave vulcanization process, the vulcanization temperature is 145-155° C. and the insulation time is 110-130 min.

[0012] Preferably, step S3 also includes, before bonding the first thermal insulation layer bottom preform, the anti-ablation layer and the second thermal insulation layer bottom preform, grinding the upper surface of the first thermal insulation bottom preform and the lower surface of the second thermal insulation bottom preform, and cleaning the surface with ethyl acetate.

[0013] Preferably, step S5 further comprises, before the autoclave vulcanization process, pasting polytetrafluoroethylene tape from the metal piece connecting the bottom layer of the second insulation layer to the bonding edge position with the insulation layer cover layer to form an artificial debonding area.

[0014] Preferably, step S5 further comprises, before the autoclave vulcanization process, providing a raw rubber sheet in the bonding area between the bottom layer of the thermal insulation layer and the top layer of the thermal insulation layer.

[0015] Preferably, it also includes: using insulating raw rubber sheet to preform the joint protection layer preform by molding, the vulcanization temperature of the preformed joint protection layer is 85-95°C, and the heat preservation is 110-130min; sandblasting the bonding surface of the metal joint, polishing the joint protection layer preform, applying adhesive on the bonding surface of the metal joint and the bonding surface of the joint protection layer preform, and bonding the metal joint to the joint protection layer preform.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The method for preparing the thermal insulation layer structure of a solid rocket engine of the present invention comprises prefabricating a first thermal insulation layer bottom layer and a second thermal insulation layer bottom layer, and then coating the anti-ablation layer between the first thermal insulation layer bottom layer and the second thermal insulation layer bottom layer with an adhesive, thereby ensuring that the position of the anti-ablation layer is fixed, and at the same time, enhancing the bonding performance of the anti-ablation layer with other interfaces. The autoclave pressure vulcanization process can solve the problem that many vertical surfaces cannot be pressurized during the molding process, and ensure the bonding quality. During the pressurization process, a pressure perpendicular to the bonding surface can be applied to the bonding area, and at the same time, the thermal insulation layer at the connection metal parts between the thermal insulation layer bottom layer and the cover layer can be prevented from being damaged due to excessive pressure during the overall molding pressurization process. The autoclave molding process can save the cost of the mold positive mold, and the autoclave process can mold multiple thermal insulation layers at one time. At the same time, it can avoid the energy loss caused by the heat transfer of the mold, shorten the molding time, and improve production efficiency.

[0017] The preparation method of the solid rocket engine insulation layer structure of the present invention, through comparison of ordinary high-temperature tape, debonding cloth, release paper and polytetrafluoroethylene tape, finds that the strip polytetrafluoroethylene tape (film) has good ductility and good viscosity, strong operability during the pasting process, and will not have imbalance phenomena such as wrinkles and air entrapment, thereby avoiding the cover layer being pressed and wrinkled to damage the surface during the overall molding process. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic diagram of a thermal insulation layer of a solid rocket engine according to an embodiment of the present invention; Among them: 1-the bottom layer of the first insulation layer; 2-the bottom layer of the second insulation layer; 3-the insulation layer cover layer; 4-the anti-ablation layer; 5-the joint protection layer; 6-the bottom layer of the insulation layer; 7-the metal joint. DETAILED DESCRIPTION

[0019] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solution of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Example 1 like Figure 1 As shown, the thermal insulation layer structure of a solid rocket engine according to an embodiment of the present invention comprises: A first heat-insulating layer bottom layer 1, the outer wall of which is suitable for being connected to the engine housing; A second heat-insulating layer bottom layer 2, which is disposed on the inner side of the first heat-insulating layer bottom layer 1 and connected to the first heat-insulating layer bottom layer 1; The anti-ablation layer 4 is provided between the first heat-insulating layer bottom layer 1 and the second heat-insulating layer bottom layer 2, and is located at one end of the first heat-insulating layer bottom layer 1 connected to the nozzle; The heat-insulating layer cover layer 3 is arranged on the inner side of the second heat-insulating layer bottom layer 2 and connected to the second heat-insulating layer bottom layer 2; The metal joint 7 is arranged on the outer side of the first heat-insulating layer bottom layer 1 and is located at one end of the first heat-insulating layer bottom layer 1 connected to the nozzle.

[0021] The thermal insulation layer structure of the solid rocket engine of the embodiment of the present invention, wherein the thermal insulation layer cover layer is placed on the inner side, contacts with the propellant during operation, and is first ablated during the operation of the engine. The anti-ablation layer is placed inside the bottom layer near the nozzle. The metal joint protective layer is pasted on the outside of the metal part. The thermal insulation bottom layer is bonded to the shell material, and the thermal insulation bottom layer and the thermal insulation cover layer simultaneously play a thermal protection role to protect the combustion chamber shell. The metal joint is placed on the outside of the bottom layer, and is used to reinforce the head opening and install the ignition device and the nozzle assembly.

[0022] The solid rocket engine insulation layer structure of the embodiment of the present invention is prepared by a method combining a compression molding process with an autoclave molding process. The molded bottom layer and cover layer have stable process, good surface quality, and good internal quality. The thickness requirements of each insulation layer can be guaranteed, the size is accurate, and the product quality is significantly improved.

[0023] In some embodiments, a joint protection layer 5 is further provided on the outer side of the metal joint 7 , and the joint protection layer 5 is connected to the metal joint 7 .

[0024] In some embodiments, the first insulation layer bottom layer, the second insulation layer bottom layer, and the insulation layer cover layer are made of insulation materials; the insulation materials include fillers and a matrix, the filler is at least one of asbestos and silicon dioxide, and the matrix is ​​at least one of nitrile rubber, styrene-butadiene rubber, EPDM rubber, and silicone rubber. It can also be made of epoxy resin or phenolic resin added with carbon fiber or aramid fiber and other materials, with good heat insulation, ablation resistance, scouring resistance and other properties, ensuring that the engine can withstand ablation and scouring under high temperature and high pressure and still work reliably for a long time.

[0025] Example 2 The solid rocket engine thermal insulation layer structure of the present invention comprises: A first heat-insulating layer bottom layer 1, the outer wall of which is suitable for being connected to the engine housing; A second heat-insulating layer bottom layer 2, which is disposed on the inner side of the first heat-insulating layer bottom layer 1 and connected to the first heat-insulating layer bottom layer 1; The anti-ablation layer 4 is provided between the first heat-insulating layer bottom layer 1 and the second heat-insulating layer bottom layer 2, and is located at one end of the first heat-insulating layer bottom layer 1 connected to the nozzle; The heat-insulating layer cover layer 3 is arranged on the inner side of the second heat-insulating layer bottom layer 2 and connected to the second heat-insulating layer bottom layer 2; A metal joint 7, which is arranged on the outer side of the first heat-insulating layer bottom layer 1 and located at one end of the first heat-insulating layer bottom layer 1 connected to the nozzle; The joint protection layer 5 is arranged on the outer side of the metal joint 7 , and the joint protection layer 5 is connected to the metal joint 7 .

[0026] The bottom layer of the first insulation layer, the bottom layer of the second insulation layer and the cover layer of the insulation layer are made of insulation materials; the insulation materials include fillers and a matrix, the fillers are silicon dioxide and the matrix is ​​nitrile rubber.

[0027] The method for preparing the thermal insulation layer structure of a solid rocket engine of this embodiment comprises the following steps: 1. According to the thickness requirements of each part of the insulation layer, use an open mill to grind the incoming materials into sheets of different thicknesses. During the grinding process, the raw materials need to be thinned and triangularly packaged to improve the uniformity and density of the incoming materials. The calendering effect of EPDM rubber is reduced by the triangular package operation; 2. Design the cutting template according to the thickness and size requirements of different parts of the insulation layer, and cut raw sheets of different specifications according to the cutting template; 3. Use the insulating raw rubber sheet to preform the joint protection layer preform by molding. The vulcanization temperature of the preformed joint protection layer is 90°C, and the temperature is kept for 120 minutes, which is controlled within the vulcanization induction period. In order to enhance the bonding performance between the metal and the thermal insulation material, the bonding surface of the metal joint is sandblasted, and after the joint protection layer preform is polished, the bonding surface of the metal joint 7 and the bonding surface of the joint protection layer preform are coated with adhesive, the metal joint 7 is bonded to the joint protection layer preform, and the metal joint protection layer preform is fixed to the metal joint by a ring and a clamp to form a metal joint assembly; 4. On the metal joint, lay different specifications of insulation raw rubber sheets according to the material laying design until the required thickness and weight are reached; 5. According to the selected thickness of the first thermal insulation layer bottom layer 1, the first thermal insulation layer bottom layer 1 is preformed by using raw rubber sheet and molding method, the vulcanization temperature is 90°C, and the temperature is kept for 120 minutes to obtain a first thermal insulation layer bottom layer preform; the outer side of the first thermal insulation layer bottom layer preform is connected to the metal joint 7; 6. According to the selected thickness of the second heat insulation layer bottom layer 2, the second heat insulation layer bottom layer 2 is prefabricated by using raw rubber sheets and a molding method, with a vulcanization temperature of 90° C. and heat preservation for 120 minutes to obtain a second heat insulation layer bottom layer prefabricated part; 7. Grind the upper surface of the first thermal insulation bottom layer preform and the lower surface of the second thermal insulation bottom layer preform, clean the surface with ethyl acetate to enhance the reliability of the bonding interface, then apply adhesive and let it air-dry for 20 minutes; set adhesive on the surface of the anti-ablation layer 4, the contact between the upper surface of the first thermal insulation bottom layer preform and the anti-ablation layer, and the contact between the lower surface of the second thermal insulation bottom layer preform and the anti-ablation layer 4, and sequentially set the first thermal insulation bottom layer preform, the anti-ablation layer 4, and the second thermal insulation bottom layer preform in the mold, and prepare the thermal insulation bottom layer 6 by autoclave vulcanization process, the vulcanization temperature is 150°C, and the heat preservation is 120 minutes; 8. According to the selected thickness of the heat insulation layer cover layer 3, the heat insulation layer cover layer preform is formed by using raw rubber sheets and an overall one-step vulcanization process, the vulcanization temperature is 90°C, and the heat preservation time is 120 minutes; 9. A polytetrafluoroethylene tape is pasted at the bonding edge of the second insulation layer bottom layer 2 connecting the metal parts to the insulation layer cover layer 3 to form an artificial debonding area; a raw rubber sheet with a thickness of 0.4 mm is pasted at the bonding position of the insulation bottom layer and the insulation cover layer, and the insulation bottom layer and the insulation cover layer are concentrically aligned; the insulation layer bottom layer 6 and the insulation cover layer preforms are placed in the mold in sequence, and the solid rocket engine insulation layer structure is obtained by vulcanization molding in an autoclave at a vulcanization temperature of 150°C and insulation for 120 minutes. During the pressurization process, a pressure perpendicular to the bonding surface can be applied to the bonding area, and at the same time, the insulation layer at the second insulation layer bottom layer connecting the metal parts can be prevented from being damaged due to excessive pressure during the overall molding and pressurization process of the insulation bottom layer and the cover layer. Autoclave pressurization can save the cost of the mold positive mold, and the autoclave process can mold multiple insulation layers at one time, thereby improving production efficiency.

[0028] Example 3 The method for preparing the thermal insulation layer structure of a solid rocket engine of this embodiment comprises the following steps: 1. According to the thickness requirements of each part of the insulation layer, use an open mill to grind the incoming materials into sheets of different thicknesses. During the grinding process, the raw materials need to be thinned and triangularly packaged to improve the uniformity and density of the incoming materials. The calendering effect of EPDM rubber is reduced by the triangular package operation; 2. Design the cutting template according to the thickness and size requirements of different parts of the insulation layer, and cut raw sheets of different specifications according to the cutting template; 3. Use the insulating raw rubber sheet to preform the joint protection layer preform by molding. The vulcanization temperature of the preformed joint protection layer is 85°C, and the temperature is kept for 110 minutes, which is controlled within the vulcanization induction period. In order to enhance the bonding performance between the metal and the thermal insulation material, the bonding surface of the metal joint is sandblasted, and after the joint protection layer preform is polished, the adhesive is applied to the bonding surface of the metal joint 7 and the bonding surface of the joint protection layer preform, and the metal joint 7 is bonded to the joint protection layer preform. The metal joint protection layer preform is fixed to the metal joint by a ring and a clamp to form a metal joint assembly; 4. On the metal joint, lay different specifications of insulation raw rubber sheets according to the material laying design until the required thickness and weight are reached; 5. According to the selected thickness of the first thermal insulation layer bottom layer 1, the first thermal insulation layer bottom layer 1 is preformed by using raw rubber sheet and molding method, the vulcanization temperature is 85°C, and the temperature is kept for 110 minutes to obtain a first thermal insulation layer bottom layer preform; the outer side of the first thermal insulation layer bottom layer preform is connected to the metal joint 7; 6. According to the selected thickness of the second heat insulation layer bottom layer 2, the second heat insulation layer bottom layer 2 is prefabricated by using raw rubber sheets by a molding method, the vulcanization temperature is 85° C., and the temperature is kept for 110 minutes to obtain a second heat insulation layer bottom layer prefabricated part; 7. Grind the upper surface of the first thermal insulation bottom layer preform and the lower surface of the second thermal insulation bottom layer preform, clean the surface with ethyl acetate to enhance the reliability of the bonding interface, then apply adhesive and let it air-dry for 20 minutes; set adhesive on the surface of the anti-ablation layer 4, the contact between the upper surface of the first thermal insulation bottom layer preform and the anti-ablation layer, and the contact between the lower surface of the second thermal insulation bottom layer preform and the anti-ablation layer 4, and sequentially set the first thermal insulation bottom layer preform, the anti-ablation layer 4, and the second thermal insulation bottom layer preform in the mold, and prepare the thermal insulation bottom layer 6 by autoclave vulcanization process, the vulcanization temperature is 145°C, and the heat preservation is 110 minutes; 8. According to the selected thickness of the heat insulation layer cover layer 3, the heat insulation layer cover layer preform is formed by using raw rubber sheets and an overall one-step vulcanization process, the vulcanization temperature is 85°C, and the heat preservation time is 110 minutes; 9. Paste polytetrafluoroethylene tape from the second insulation layer bottom layer 2 connecting the metal parts to the bonding edge of the insulation layer cover layer 3 to form an artificial debonding area; paste a raw rubber sheet with a thickness of 0.3 mm at the bonding position of the insulation bottom layer and the insulation cover layer, and align the concentric circles of the insulation bottom layer and the insulation cover layer; put the insulation layer bottom layer 6 and the insulation layer cover layer prefabricated parts into the mold in turn, and vulcanize them in an autoclave at a vulcanization temperature of 145°C and keep them warm for 110 minutes to obtain the solid rocket engine insulation layer structure.

[0029] Example 4

[0030] The method for preparing the thermal insulation layer structure of a solid rocket engine of this embodiment comprises the following steps: 1. According to the thickness requirements of each part of the insulation layer, use an open mill to grind the incoming materials into sheets of different thicknesses. During the grinding process, the raw materials need to be thinned and triangularly packaged to improve the uniformity and density of the incoming materials. The calendering effect of EPDM rubber is reduced by the triangular package operation; 2. Design the cutting template according to the thickness and size requirements of different parts of the insulation layer, and cut raw sheets of different specifications according to the cutting template; 3. Use the insulating raw rubber sheet to preform the joint protection layer preform by molding. The vulcanization temperature of the preformed joint protection layer is 95°C, and the temperature is kept for 130 minutes, which is controlled within the vulcanization induction period. In order to enhance the bonding performance between the metal and the thermal insulation material, the bonding surface of the metal joint is sandblasted, and after the joint protection layer preform is polished, the bonding surface of the metal joint 7 and the bonding surface of the joint protection layer preform are coated with adhesive, the metal joint 7 is bonded to the joint protection layer preform, and the metal joint protection layer preform is fixed to the metal joint by a ring and a clamp to form a metal joint assembly; 4. On the metal joint, lay different specifications of insulation raw rubber sheets according to the material laying design until the required thickness and weight are reached; 5. According to the selected thickness of the first insulation layer bottom layer 1, the first insulation layer bottom layer 1 is preformed by molding using raw rubber sheets, the vulcanization temperature is 95°C, and the temperature is kept for 130 minutes to obtain a first insulation layer bottom layer preform; the outer side of the first insulation layer bottom layer preform is connected to the metal joint 7; 6. According to the selected thickness of the second heat insulation layer bottom layer 2, the second heat insulation layer bottom layer 2 is preformed by using raw rubber sheets and a molding method, with a vulcanization temperature of 95° C. and heat preservation for 130 minutes to obtain a second heat insulation layer bottom layer preform; 7. Grind the upper surface of the first thermal insulation bottom layer preform and the lower surface of the second thermal insulation bottom layer preform, clean the surface with ethyl acetate to enhance the reliability of the bonding interface, then apply adhesive and let it air-dry for 20 minutes; set adhesive on the surface of the anti-ablation layer 4, the contact between the upper surface of the first thermal insulation bottom layer preform and the anti-ablation layer, and the contact between the lower surface of the second thermal insulation bottom layer preform and the anti-ablation layer 4, and sequentially set the first thermal insulation bottom layer preform, the anti-ablation layer 4, and the second thermal insulation bottom layer preform in the mold, and prepare the thermal insulation bottom layer 6 by autoclave vulcanization process, the vulcanization temperature is 155°C, and the heat preservation is 130 minutes; 8. According to the selected thickness of the heat insulation layer cover layer 3, the heat insulation layer cover layer preform is formed by using raw rubber sheets and an overall one-step vulcanization process, the vulcanization temperature is 95°C, and the heat preservation time is 130 minutes; 9. Paste polytetrafluoroethylene tape from the second insulation layer bottom layer 2 connecting the metal parts to the bonding edge of the insulation layer cover layer 3 to form an artificial debonding area; paste a raw rubber sheet with a thickness of 0.3 mm at the bonding position of the insulation bottom layer and the insulation cover layer, and align the concentric circles of the insulation bottom layer and the insulation cover layer; put the insulation layer bottom layer 6 and the insulation layer cover layer prefabricated parts into the mold in turn, and vulcanize them in an autoclave at a vulcanization temperature of 155°C and keep them warm for 130 minutes to obtain the solid rocket engine insulation layer structure.

[0031] Comparative Example 1 The difference between this comparative example and Example 2 is that, instead of pasting polytetrafluoroethylene tape at the connection metal piece at the bottom layer of the second thermal insulation layer to the bonding edge of the artificial debonding layer, a high-temperature tape is provided as the artificial debonding layer.

[0032] Comparative Example 2 The difference between this comparative example and Example 2 is that the preparation of the bottom layer of the heat insulation layer is different. The bottom layer of the heat insulation layer is not prefabricated separately in the upper and lower layers, but is directly laid and formed in one step, that is, the bottom layer of the heat insulation layer is prepared by directly laying a raw rubber sheet in the mold to a set thickness, placing an anti-ablation layer, and then laying a raw rubber sheet on the anti-ablation layer to a selected thickness of the heat insulation layer, and preparing the bottom layer of the heat insulation layer through an autoclave vulcanization process. The remaining steps are the same as those in Example 2.

[0033] The ablation performance and strength performance of the thermal insulation layer structures obtained in Examples 2, 3, 4 and Comparative Examples 1 and 2 were measured, and the position of the ablation layer in the thermal insulation layer was measured to calculate the deviation between its position and the predetermined position. The test results are shown in Table 1 below.

[0034] It can be seen from the data in Table 1 below that, compared with Comparative Example 2, the thermal insulation layer prepared by each embodiment of the present invention has significantly better ablation performance and strength performance. More importantly, the position of the anti-ablation layer in the thermal insulation layer after molding is more accurate and the position deviation is smaller. Compared with Comparative Example 1 which uses high-temperature tape as an artificial debonding layer, the present invention uses polytetrafluoroethylene tape, and it is found that the strip polytetrafluoroethylene tape (film) has good ductility and good adhesion, and is easy to operate during the pasting process. There will be no imbalance phenomena such as wrinkles and air inclusions, which can prevent the cover layer from being pressed and wrinkled and damaging the surface during the overall molding process; Table 1

[0035] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A method for preparing a thermal insulation layer structure of a solid rocket engine, characterized in that: The solid rocket motor insulation layer structure comprises: A first heat-insulating bottom layer, wherein the outer wall of the first heat-insulating bottom layer is suitable for connecting with the engine casing; A second heat-insulating layer bottom layer, wherein the second heat-insulating layer bottom layer is disposed on the inner side of the first heat-insulating layer bottom layer and connected to the first heat-insulating layer bottom layer; an anti-ablation layer, the anti-ablation layer being disposed between the first heat-insulating layer bottom layer and the second heat-insulating layer bottom layer and being located at one end of the first heat-insulating layer bottom layer connected to the nozzle; A heat-insulating layer cover layer, the heat-insulating layer cover layer is arranged on the inner side of the second heat-insulating layer bottom layer and connected to the second heat-insulating layer bottom layer; A metal joint, the metal joint is arranged on the outer side of the bottom layer of the first heat insulation layer and is located at one end of the bottom layer of the first heat insulation layer connected to the nozzle; The preparation method comprises the following steps: S1: prefabricate the first thermal insulation layer bottom layer by molding using a raw rubber sheet according to the selected thickness of the first thermal insulation layer bottom layer to obtain a first thermal insulation layer bottom layer prefabricated part; connect the outer side of the first thermal insulation layer bottom layer prefabricated part to a metal joint; S2: prefabricating the second heat insulation layer bottom layer by molding using a raw rubber sheet according to the selected thickness of the second heat insulation layer bottom layer to obtain a second heat insulation layer bottom layer prefabricated part; S3: bonding the first thermal insulation layer bottom preform, the anti-ablation layer, and the second thermal insulation layer bottom preform, and then preparing the thermal insulation layer bottom by a hot-press vulcanization process in a mold; S4: according to the selected thickness of the heat insulation layer cover layer, using the raw rubber sheet, adopting an overall one-step vulcanization process to form the heat insulation layer cover layer preform; S5: placing the preforms of the bottom layer and the cover layer of the thermal insulation layer in the mold, and molding them through a hot-press vulcanization process to obtain the thermal insulation layer structure of the solid rocket engine.

2. The method for preparing the thermal insulation layer structure of a solid rocket engine according to claim 1, characterized in that: A joint protection layer is also provided on the outer side of the metal joint, and the joint protection layer is connected to the metal joint.

3. The method for preparing the thermal insulation layer structure of a solid rocket engine according to claim 1, characterized in that: The first insulation layer bottom layer, the second insulation layer bottom layer and the insulation layer cover layer are made of insulation materials; The thermal insulation material comprises a filler and a matrix, wherein the filler is at least one of asbestos and silicon dioxide, and the matrix is ​​at least one of nitrile rubber, styrene-butadiene rubber, EPDM rubber and silicone rubber.

4. The method for preparing the thermal insulation layer structure of a solid rocket engine according to claim 1, characterized in that: In step S1, when the first insulation layer bottom layer is prefabricated by molding, the vulcanization temperature is 85-95° C. and the heat preservation time is 110-130 minutes; In step S2, when the second thermal insulation layer bottom layer is prefabricated by molding, the vulcanization temperature is 85-95° C. and the insulation time is 110-130 minutes.

5. The method for preparing the thermal insulation layer structure of a solid rocket engine according to claim 1, characterized in that: In step S3, when the bottom layer of the thermal insulation layer is prepared by an autoclave vulcanization process, the vulcanization temperature is 145-155° C. and the insulation time is 110-130 min.

6. The method for preparing the thermal insulation layer structure of a solid rocket engine according to claim 1, characterized in that: In step S4, when the insulation layer cover is prepared by autoclave vulcanization process, the vulcanization temperature is 85-95° C. and the heat preservation time is 110-130 min; In step S5, when the thermal insulation layer structure is prepared by an autoclave vulcanization process, the vulcanization temperature is 145-155° C. and the insulation time is 110-130 min.

7. The method for preparing a thermal insulation layer structure of a solid rocket engine according to claim 1, characterized in that ； Step S3 also includes, before bonding the first thermal insulation layer bottom preform, the anti-ablation layer, and the second thermal insulation layer bottom preform, grinding the upper surface of the first thermal insulation layer bottom preform and the lower surface of the second thermal insulation layer bottom preform, and cleaning the surface with ethyl acetate.

8. The method for preparing the thermal insulation layer structure of a solid rocket engine according to claim 1, characterized in that: Step S5 also includes, before the autoclave vulcanization process, pasting polytetrafluoroethylene tape from the second insulation layer bottom layer connecting the metal piece to the bonding edge position with the insulation layer cover layer to form an artificial debonding area.

9. The method for preparing the thermal insulation layer structure of a solid rocket engine according to claim 1, characterized in that: Step S5 also includes, before the autoclave vulcanization process, providing a raw rubber sheet in the bonding area between the bottom layer of the thermal insulation layer and the top layer of the thermal insulation layer.

10. The method for preparing a thermal insulation layer structure of a solid rocket engine according to claim 1, characterized in that: It also includes: using insulating raw rubber sheets to preform joint protection layer prefabricated parts through molding, the vulcanization temperature of the preform joint protection layer prefabricated parts is 85-95°C, and the heat preservation is 110-130 minutes; sandblasting the bonding surface of the metal joint, grinding the joint protection layer prefabricated parts, applying adhesive on the bonding surface of the metal joint and the bonding surface of the joint protection layer prefabricated parts, and bonding the metal joint to the joint protection layer prefabricated parts.

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