Fiber winding engine shell artificial debonding layer autoclave forming tool and method

Abstract

The application provides a fiber winding engine shell artificial debonding layer autoclave forming tool and method, the tool comprises a forming die and a shaping die matched with the forming die, the forming die is semispherical, mounting holes are arranged on the top of the forming die near the center and the outer edge, and the shaping die is fixedly connected with the forming die through the mounting holes, so that the artificial debonding layer between the forming die and the shaping die is fastened on the forming die; the forming die comprises a flat section, a circular arc section and a straight section from top to bottom, the flat section is horizontally arranged and is in a planar ring shape or a conical shape, the straight section is in a cylindrical shape or a conical shape, the upper end of the circular arc section is integrated with the flat section, and the lower end of the circular arc section is integrated with the straight section. Compared with the traditional mold pressing forming method, the application has the advantages of simple tool design, small investment, simple and fast patch module operation, high product qualification rate and the like; meanwhile, single tank multi-mold batch production can be realized, and the production efficiency is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of rubber insulation material curing and molding technology, specifically to a tooling and method for molding a heat-sealed autoclave for an artificial debonding layer of a fiber-wound engine housing. Background Technology

[0002] The artificial debonding layer of the fiber-wound engine casing is located between the inner wall of the engine casing and the propellant grain, and is an important part of the insulation layer inside the fiber-wound engine casing. During the operation of the fiber-wound engine casing, the artificial debonding layer absorbs a large amount of heat through its own heat absorption, decomposition, ablation, and carbonization, preventing the high-temperature combustion gases and heat from damaging the casing, ensuring that the fiber-wound engine does not overheat and loses strength, and can operate normally.

[0003] Currently, manual release layers are mostly cured using the traditional molding method of press molding, which has the following drawbacks: the molding tooling design is complex, requiring the design of upper and lower molds, resulting in high tooling design and manufacturing costs; manual release layers are applied to the mold by hand, resulting in low molding efficiency; the product quality cannot be monitored by opening the tooling during the molding process, resulting in a low product qualification rate; press molding can only produce one mold at a time, resulting in low production efficiency. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a tooling and method for forming a heat-pressed can with an artificial debonding layer for fiber-wound engine housings. Compared with traditional compression molding methods, this method has advantages such as simple tooling design and low investment, simple and quick patch molding operation, and high product qualification rate. At the same time, it can produce multiple batches of a single can using multiple molds, which greatly improves production efficiency.

[0005] To solve the above-mentioned technical problems, in a first aspect, the present invention provides a hot autoclave forming tool for an artificial debonding layer of a fiber-wound engine housing, including a forming mold and a shaping mold that cooperates with the forming mold. The forming mold is hemispherical, and mounting holes are provided at the top near the center and the outer edge of the forming mold. The shaping mold is fixedly connected to the forming mold through the mounting holes, thereby fastening the artificial debonding layer located between the two onto the forming mold.

[0006] The molding die includes a flat section, an arc section, and a straight section from top to bottom. The flat section is in the shape of a plane ring or cone, the straight section is in the shape of a cylinder or cone, the upper end of the arc section is connected to the flat section, and the lower end of the arc section is connected to the straight section.

[0007] Furthermore, the shaping mold has multiple lobes arranged circumferentially around the forming mold.

[0008] In a second aspect, the present invention provides a method for forming an autoclave for an artificial debonding layer of a fiber-wound engine housing, comprising:

[0009] S1. Based on the design drawings of the artificial release layer, calculate the size of the ring-shaped film corresponding to the flat section and the size of the adhesive strip corresponding to the straight section and the arc section, cut out the corresponding ring-shaped film, and squeeze out the corresponding adhesive strip.

[0010] S2. Apply a ring-shaped film to the flat section. For the arc section and the straight section, use a circumferential layering method to wrap the film from small diameter to large diameter. The joints between the film strip and the ring-shaped film are then joined.

[0011] S3. Lay the shaping mold on the molding mold and fasten the shaping mold to the molding mold so that the shaping mold covers the artificial release layer;

[0012] S4. Pre-curing of the artificial release layer;

[0013] S5. Inspection and trimming of the artificial debonding layer;

[0014] S6. Artificial debonding layer hot autoclave molding.

[0015] Furthermore, in step S1, based on the shrinkage rate of the raw and cooked rubber compounds of the insulation material, an annular rubber sheet is precisely cut using an automatic rubber sheet cutting device, and a rubber extruder is used to extrude rubber strips of uniform size, so that both the cut annular rubber sheet and the extruded rubber strip have sufficient shrinkage allowance.

[0016] Further, step S2 includes: using the inner diameter of the flat section of the molding die as a reference to install the annular film, and starting from the outer diameter of the flat section, winding the rubber strip from top to bottom in a circumferential direction. During the winding process, the thickness of the winding rubber strip is measured in real time to ensure that the total winding thickness meets the design thickness requirements.

[0017] Further, step S4 includes: after the artificial release layer is fastened to the outer surface of the molding mold, the whole assembly is placed in an oven for pre-curing. The pre-curing parameters are 90℃~120℃ for 90min~120min, and after the pre-curing is completed, the whole assembly is removed from the oven.

[0018] Further, step S5 includes: removing the molding die, measuring the surface of the pre-cured artificial release layer using a template of the artificial release layer, measuring the gap between the template and the pre-cured artificial release layer with a feeler gauge to monitor the surface quality of the product; inserting a fine needle into the pre-cured artificial release layer to inspect the thickness of each part, and comparing the inspection results with the design drawings to monitor the dimensions of each part of the product.

[0019] Further, step S5 includes: grinding and trimming the high points of the artificial release layer to ensure the quality of the product surface; cleaning the ground area with ethyl acetate or anhydrous ethanol after grinding; and filling any areas where the artificial release layer is not thick enough with raw rubber sheets of the corresponding size to ensure the product dimensions.

[0020] Further, step S6 includes: sequentially laying a polytetrafluoroethylene film, a breathable felt, and a vacuum film bag on the surface of the artificial release layer; sealing the vacuum film bag to the outer edge of the molding die using high-temperature sealing tape; using a vacuum pump to remove air between the vacuum film bag and the molding die; using an autoclave to cure the artificial release layer; and after curing, sequentially removing the vacuum film bag, the breathable felt, and the polytetrafluoroethylene film from the surface of the artificial release layer.

[0021] Further, in step S6, the autoclave curing parameters are as follows: initial pressure of 0.4MPa to 0.8MPa, temperature rise to 100℃ to 120℃, and heat preservation for 30min to 60min; after heat preservation, continue to pressurize to 1.0MPa to 2.0MPa, maintain the pressure, continue to heat to 130℃ to 150℃, and heat preservation for 120min to 180min; after heat preservation, the autoclave is cooled to below 60℃ before being removed from the autoclave.

[0022] The beneficial effects of this invention are as follows:

[0023] 1. The tooling design of this invention is simple and low in cost. Compared with the traditional molding die which requires the design of two molds, this invention only requires a simple single mold (forming die) designed based on the inner surface of the manual release layer to meet production requirements.

[0024] 2. The present invention has high molding efficiency. The rounded corners and straight edges are uniformly molded using a wrapping adhesive strip, which overcomes the shortcomings of traditional manual patch molding, such as large errors, uneven patching, and low molding efficiency.

[0025] 3. The production process of this invention is monitorable, resulting in a high finished product qualification rate. The autoclave molding method for artificial release layers, after pre-curing and finishing, ensures both product thickness and surface quality. In contrast, the artificial release layer production process in traditional compression molding cannot be monitored or finished, leading to significant surface defects and a high scrap rate after demolding.

[0026] 4. This invention has high production efficiency. Traditional compression molding can only produce one mold at a time, while autoclave molding with manual debonding can achieve batch molding of multiple molds in one autoclave, resulting in high production efficiency. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the tooling of the present invention.

[0028] Figure reference numerals: 1. Molding mold; 2. Shaping mold; 3. Outer edge; 4. Flat section; 5. Arc section; 6. Straight section; 7. Bolt; 8. Annular film; 9. Rubber strip. Detailed Implementation

[0029] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0030] like Figure 1 As shown, this embodiment provides a hot press mold for forming an artificial debonding layer of a fiber-wound engine housing, including a forming mold 1 and a shaping mold 2 that cooperates with the forming mold 1;

[0031] The molding mold 1 is hemispherical in shape. A circular groove is formed at the top of the molding mold 1, and a mounting hole is formed at the bottom of the circular groove. An outer edge 3 is formed at the bottom of the molding mold 1, and multiple mounting holes are evenly distributed around the outer edge 3. The molding mold 1 includes a flat section 4, an arc section 5, and a straight section 6 from top to bottom. The flat section 4 is planar annular or conical. In this embodiment, the flat section 4 is planar annular, and the circular groove is located inside the flat section 4 and arranged coaxially with the flat section 4. The straight section 6 is cylindrical or conical. In this embodiment, the straight section 6 is cylindrical, and the outer edge 3 is fixedly connected to the lower end face of the straight section 6. The upper end of the arc section 5 is integrated with the outer diameter of the flat section 4, and the lower end of the arc section 5 is integrated with the upper end of the straight section 6.

[0032] The shaping mold 2 has multiple lobes arranged around the forming mold 1 in a circumferential direction. The upper and lower ends of the shaping mold 2 are fixedly connected to the forming mold 1 by bolts 7 passing through the mounting holes, thereby fastening the artificial release layer located between the two to the forming mold 1. Figure 1 The image only shows one segment of the shaping mold 2.

[0033] The forming method of the autoclave forming tooling for the artificial debonding layer of the engine casing using this fiber-wound engine housing is as follows:

[0034] S1. Pre-treatment of Insulation Material: Based on the design drawings of the artificial release layer, calculate the dimensions of the annular rubber sheet 8 corresponding to the flat section 4, and the dimensions of the rubber strip 9 corresponding to the straight section 6 and the arc section 5. According to the shrinkage rate of the raw and cooked rubber compounds of the insulation material, use a cutting system to precisely cut out the annular rubber sheet 8, and use a rubber extruder to extrude rubber strips 9 of uniform size, ensuring that both the cut annular rubber sheet 8 and the extruded rubber strip 9 have sufficient shrinkage allowance. The artificial release layer is composed of the annular rubber sheet 8 and the rubber strip 9.

[0035] S2. Laying and winding of the artificial release layer: The annular film 8 is installed based on the inner diameter of the flat section 4 of the molding mold 1. The adhesive strip 9 is wound from top to bottom in a circular direction starting from the outer diameter of the flat section 4. The thickness of the wrapped adhesive strip 9 is measured in real time during the winding process to ensure that the total winding thickness meets the design thickness requirements. Figure 1 The diagram only shows the rubber strip 9 wrapped around the lower part of the molding die 1.

[0036] S3. Fixing the artificial release layer: Place the shaping mold 2 on the molding mold 1 and connect the shaping mold 2 to the molding mold 1 with bolts 7, so that the shaping mold 2 presses on the artificial release layer;

[0037] S4. Pre-curing of the artificial release layer: After the artificial release layer is fastened to the outer surface of the molding mold 1, the whole thing is placed in the oven for pre-curing. The pre-curing parameters are 90℃~120℃ for 90min~120min. After the heat preservation is completed, the whole thing is removed from the oven.

[0038] S5. Inspection and finishing of the artificial debonding layer:

[0039] Remove the shaping mold 2, use the outer surface template of the artificial release layer to measure the outer surface of the pre-cured artificial release layer, and use a feeler gauge to measure the gap between the outer surface template and the pre-cured artificial release layer; use a fine needle to insert into the pre-cured artificial release layer to check the thickness of each part, and compare the inspection results with the design drawings.

[0040] Based on the measured gap values, the high points of the artificial release layer are polished and smoothed to create a rounded transition. After polishing, the polished areas are cleaned with ethyl acetate or anhydrous ethanol to remove excess material and ensure the product is free of impurities. Based on the measured dimensions of each part, for areas where the artificial release layer thickness is insufficient, raw rubber sheets of the corresponding size are cut and used to fill the gaps to ensure the product dimensions are met.

[0041] S6. Manual debonding layer autoclave molding:

[0042] On the surface of the artificial release layer, lay a polytetrafluoroethylene film, a breathable felt, and a vacuum film bag in sequence. Apply a ring of high-temperature sealing tape to the outer edge 3 of the molding mold 1. Simultaneously, apply high-temperature sealing tape around the entire circumference of the vacuum film bag, 4cm-10cm from the edge. Do not remove the white release film on the surface of the high-temperature sealing tape. After applying the high-temperature sealing tape, check its position to ensure there are no through-air bubbles to guarantee the airtightness of the vacuum film bag. Remove the white release film from the surfaces of the vacuum film bag and the high-temperature sealant on the molding mold 1. Adhere the two high-temperature sealants together, starting from the initial bonding position on the vacuum bag and pressing the two sealing tapes together from left to right until a complete seal is achieved, ensuring no gaps between the vacuum tape, sealant, and mold bonding area. After sealing, the entire assembly is moved into an autoclave. Before curing, a vacuum pump is used to evacuate the vacuum film bag through the reserved vacuum nozzle until there is no air in the bag. After evacuating to a vacuum degree of ≤-0.095Mpa, the vacuuming is stopped and the vacuum degree is maintained constant for 10min to 15min. The curing program is then started. After curing, the vacuum film bag, breathable felt, and polytetrafluoroethylene film on the surface of the artificial release layer are removed in sequence.

[0043] The autoclave curing parameters are as follows: initial pressure of 0.4MPa to 0.8MPa, temperature rise to 100℃ to 120℃, and hold for 30min to 60min; after holding, continue to pressurize to 1.0MPa to 2.0MPa, maintain the pressure, continue to heat to 130℃ to 150℃, and hold for 120min to 180min; after holding, remove from the autoclave when it cools down to below 60℃.

[0044] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method for forming an autoclave for an artificial debonding layer of a fiber-wound engine housing, characterized in that: The molding method is achieved by molding tooling, which includes a molding mold (1) and a shaping mold (2) that cooperates with the molding mold (1). The molding mold (1) is hemispherical. Mounting holes are opened at the top of the molding mold (1) near the center and at the outer edge (3). The shaping mold (2) is fixedly connected to the molding mold (1) through the mounting holes, thereby fastening the artificial release layer located between the two to the molding mold (1). The forming mold (1) includes a flat section (4), an arc section (5) and a straight section (6) from top to bottom. The flat section (4) is in the shape of a plane ring or cone. The straight section (6) is in the shape of a cylinder or cone. The upper end of the arc section (5) is connected to the flat section (4) as a whole. The lower end of the arc section (5) is connected to the straight section (6) as a whole. The shaping mold (2) has multiple petals arranged circumferentially around the forming mold (1); The molding method includes: S1. According to the design drawings of the artificial debonding layer, calculate the size of the ring film (8) corresponding to the flat section (4) and the size of the adhesive strip (9) corresponding to the straight section (6) and the arc section (5), cut out the corresponding ring film (8), and extrude the corresponding adhesive strip (9). S2. Apply an annular film (8) to the flat section (4). For the arc section (5) and the straight section (6), use a circumferential layer-by-layer wrapping method with adhesive strips (9) from small diameter to large diameter to install the mold. The adhesive strips (9) are joined with the annular film. Step S2 includes: using the inner diameter of the flat section (4) of the molding mold (1) as a reference to install the annular film (8), and starting from the outer diameter of the flat section (4), wrap the rubber strip (9) from top to bottom in a circular direction. During the wrapping process, the thickness of the wrapped rubber strip (9) is measured in real time to ensure that the total wrapping thickness meets the design thickness requirements. S3. Place the shaping mold (2) on the molding mold (1) and connect the shaping mold (2) to the molding mold (1) so that the shaping mold (2) presses on the artificial release layer; S4. Pre-curing of artificial release layer: After the artificial release layer is fastened to the outer surface of the molding mold (1), the whole thing is placed in the oven for pre-curing; S5. Inspection and trimming of the artificial debonding layer; Step S5 includes: removing the molding die (2), measuring the outer surface of the pre-cured artificial release layer using the outer surface template of the artificial release layer, measuring the gap between the outer surface template and the pre-cured artificial release layer using a feeler gauge, and using a fine needle to insert into the pre-cured artificial release layer to check the thickness of each part, and comparing the inspection results with the design drawings. S6. Artificial debonding layer hot autoclave molding; Step S6 includes: sequentially laying polytetrafluoroethylene film, breathable felt, and vacuum film bag on the surface of the artificial release layer; sealing the vacuum film bag with the outer edge (3) of the molding mold (1) using high-temperature sealant; using a vacuum pump to remove the air between the vacuum film bag and the molding mold (1); using a hot autoclave to cure the artificial release layer; and after curing, sequentially removing the vacuum film bag, breathable felt, and polytetrafluoroethylene film from the surface of the artificial release layer.

2. The method for forming a heat-sealed autoclave for the artificial debonding layer of a fiber-wound engine housing according to claim 1, characterized in that: In step S1, according to the shrinkage rate of the raw and cooked rubber of the insulation material, the ring-shaped rubber sheet (8) is precisely cut using the cutting system equipment, and the rubber strip (9) with uniform size is extruded using the rubber extruder, so that the cut ring-shaped rubber sheet (8) and the extruded rubber strip (9) have sufficient shrinkage allowance.

3. The method for forming a heat-sealed autoclave for the artificial debonding layer of a fiber-wound engine housing according to claim 1, characterized in that: Step S4 includes: pre-curing at 90℃~120℃ for 90min~120min, and then removing the whole unit from the oven after the pre-curing is completed.

4. The method for forming a heat-sealed autoclave for the artificial debonding layer of a fiber-wound engine housing according to claim 1, characterized in that: Step S5 includes: grinding and trimming the high points of the artificial release layer surface according to the measured gap value to make a smooth transition; cleaning the ground area with ethyl acetate or anhydrous ethanol after grinding to remove excess material and ensure that the product is free of impurities; and filling any areas where the artificial release layer is not thick enough by cutting raw rubber sheets of the corresponding size to ensure the product size.

5. The method for forming a heat-sealed autoclave for the artificial debonding layer of a fiber-wound engine housing according to claim 1, characterized in that: In step S6, the autoclave curing parameters are as follows: apply initial pressure of 0.4MPa to 0.8MPa, heat to 100℃ to 120℃, and hold for 30min to 60min; after holding, continue to pressurize to 1.0MPa to 2.0MPa, maintain the pressure, continue to heat to 130℃ to 150℃, and hold for 120min to 180min; after holding, remove from the autoclave when it cools down to below 60℃.

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