A U-shaped sandwich leading edge forming device and forming method

Abstract

The present invention discloses a U-shaped sandwich leading edge forming device and forming method, which are used for processing materials to be formed, including a forming mold and a pressurizing device. The pressurizing device includes multiple supporting members, multiple tightening members and a pressing block. A U-shaped groove is opened in the middle of the forming mold along the length direction. Multiple supporting members are supported across the platform area of ​​the forming mold. Multiple tightening members pass through through holes on the supporting members and can move up and down. The tail ends of the tightening members are detachably connected to the pressing blocks, and the pressing blocks press the bottom of the product placed in the U-shaped groove. The device can apply mechanical pressure to the laminating area at the bottom of the part in a targeted manner during the entire stage of forming the leading edge of the U-shaped sandwich, so as to avoid defects such as wrinkles and poor pressure transmission at the bottom of the part.

Description

Technical Field

[0001] The invention relates to the technical field of composite material molding, in particular to a molding device and method for a U-shaped sandwich leading edge. Background Art

[0002] The aviation industry is placing ever-higher demands on lightweight and high-performance aircraft structures. Advanced composite materials are the only way to achieve these goals. Aramid, with its low density, high specific strength and rigidity, impact resistance, and flame retardancy, is playing an increasingly important role in aviation structural materials.

[0003] Sandwich leading edge parts are a common structure in aircraft, and they mainly play the role of rectification and load-bearing. At present, carbon fiber prepreg is commonly used for the skin of sandwich leading edge parts, and the core material is mainly foam core or honeycomb core. However, in order to achieve the design requirements of weight reduction and bird strike prevention, aramid prepreg is selected as the skin material on the sandwich leading edge. The structure of the sandwich leading edge part is a "sandwich" structure with the core material bonded between the upper and lower skins. Due to the poor composite interface performance of aramid fiber prepreg itself and its easy porosity and gel extraction, the following difficulties arise in the part manufacturing process:

[0004] 1. The upper and lower skins on the leading edge of the U-shaped sandwich core tend to slide toward the bottom during pressurization and curing, causing wrinkles in the "R" area and poor pressure transmission at the bottom of the part.

[0005] 2. The composite interface performance of aramid prepreg is poor, and the autoclave curing process requires a higher curing pressure, but higher curing pressure will bring the risk of core cell collapse;

[0006] 3. The current process scheme mostly adopts the method of pre-forming aramid prepreg and then gluing it to the core material to prepare the sandwich leading edge parts. In order to improve the bonding strength between each layer of aramid prepreg, the number of layers of single-cured aramid prepreg needs to be reduced, but the number of curing times and manufacturing costs are increased, and the manufacturing cycle is extended. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a U-shaped sandwich leading edge forming device and forming method, so as to prevent defects such as wrinkles and poor pressure transmission at the bottom of the leading edge of the U-shaped sandwich.

[0008] The technical solution of the present invention to solve the above technical problems is as follows:

[0009] A U-shaped sandwich leading edge forming device includes a forming mold and a pressurizing device. The upper surface of the forming mold is a platform area, and a U-shaped groove is opened in the middle along the length direction. The profile of the U-shaped groove is consistent with the aerodynamic shape surface of the leading edge of the U-shaped sandwich to be formed. The pressurizing device includes multiple supporting members, multiple tightening members and a pressing block. The multiple supporting members span the U-shaped groove at the same interval and are supported on the platform area. The multiple tightening members pass through the through holes on the supporting members at the same interval and can move up and down. The tail ends thereof are detachably connected to the pressing block, and the pressing block presses the bottom of the product placed in the U-shaped groove.

[0010] Furthermore, the pressing block includes a steel core and a high-temperature resistant elastic material layer. The steel core is wrapped in the high-temperature resistant elastic material layer. The outer shape of the steel core is smaller than the inner surface of the front edge of the U-shaped sandwich to be formed. The crimping surface shape of the high-temperature resistant elastic material layer is adapted to the bottom of the U-shaped groove. The extrusion deformation area of ​​the high-temperature resistant elastic material layer is not larger than the area of ​​the pressurized area of ​​the material to be formed.

[0011] Furthermore, the plurality of support members are arranged at equal intervals, and the interval between two adjacent support members is 150 mm to 200 mm.

[0012] Furthermore, the support member is an arch structure, and an avoidance gap is left between the two inner side surfaces of the arch structure and the side surface of the platform area, and the avoidance gap is 5mm to 10mm.

[0013] Furthermore, a hole is opened on each support member at a center position corresponding to the bottom of the U-shaped groove.

[0014] Furthermore, when the bottom of the pressing block contacts the bottom of the U-shaped groove, a pressure adjustment distance is provided between the top of the tightening member and the upper surface of the supporting member, and the pressure adjustment distance is 10 mm to 20 mm.

[0015] The method for forming using the forming device comprises the following steps:

[0016] 1. Lay the first material to be formed layer by layer in the U-shaped groove opened on the forming mold;

[0017] 2. Lay out multiple layers of the first material to be formed and lay an isolation piece on the top layer. Press the pressing block in the pressurizing device onto the isolation piece. Cover the pressing block with a layer of vacuum piece. Seal the vacuum piece and the edge of the U-shaped groove with a seal. Evacuate the vacuum piece at room temperature to extract the air in the enclosed space enclosed by the vacuum piece and the U-shaped groove. Press the pressing block with the seal to form the lower skin with cold press. Remove the pressing block, isolation piece, seal and vacuum piece.

[0018] 3. Apply a layer of adhesive film to the inner surface of the lower skin obtained in step 2, adhere the bottoms of the two core materials to the adhesive film, and arrange them on both sides of the inner surface of the lower skin, and also apply a layer of adhesive film on the tops of the two core materials;

[0019] 4. The second material to be formed is adhered layer by layer along the inner surface contour of the lower skin and the core material contour obtained in step 2 to form a U-shaped sandwich leading edge to be solidified;

[0020] 5. Lay the isolation piece and the vacuum piece on the top of the front edge of the U-shaped sandwich core to be solidified obtained in step 4 in sequence, seal the vacuum piece and the edge of the U-shaped groove with a seal, and extract the air in the enclosed space enclosed by the vacuum piece and the U-shaped groove;

[0021] 6. Install the support member on the forming mold, connect the pressing member to the sliding part by sliding, and connect the driving end of the pressing member to the pressing block, and press the pressing block against the vacuum member in the pressurizing area;

[0022] 7. Place the overall assembly obtained in step 6 into an autoclave, and heat cure the U-shaped sandwich leading edge to be cured in step 7-4 to obtain a formed U-shaped sandwich leading edge.

[0023] Furthermore, the vacuum part includes a cold-pumped vacuum film, the sealing part includes a first sealing tape, the isolation part includes a porous isolation film, the cold-pumped vacuum film is laid on the material to be formed in the U-shaped groove, the pressing block and the tightening part are disassembled, the pressing block is pressed on the porous isolation film, the cold-pumped vacuum film is laid on the pressing block, and the first sealing tape seals the cold-pumped vacuum film and the edge of the U-shaped groove to form a cold-pumped vacuum pressurized area.

[0024] Furthermore, the vacuum component includes a cured vacuum membrane, the sealing component includes a second sealing tape, and the spacer includes a non-porous spacer membrane and a breathable fabric. The non-porous spacer membrane, breathable fabric, and cured vacuum membrane are sequentially laid on the material to be formed in the U-shaped groove. The second sealing tape seals the cured vacuum membrane with the edge of the U-shaped groove, forming a cured vacuum pressurization zone, and the pressing block presses on the cured vacuum membrane. The non-porous spacer membrane, breathable fabric, cured vacuum membrane, and second sealing tape are located within an autoclave along with the forming mold and pressurizing device. The high-temperature compressed gas within the autoclave is used to pressurize and heat the tightening component, pressing block, non-porous spacer membrane, breathable fabric, cured vacuum membrane, and the material to be formed in the U-shaped groove.

[0025] The beneficial effects of the above scheme are:

[0026] (1) A plurality of support members are arranged across the U-shaped groove at the same interval and supported on the platform area, a plurality of tightening members are arranged through the through holes on the support members at the same interval and can move up and down, and their tail ends are detachably connected to the pressing block, thereby improving the stability of the pressing block; by setting a U-shaped sandwich leading edge forming device, the degree of compaction of the prepreg at the bottom of the product during cold drawing and curing is improved, and the excessive thickness of the part caused by the resin accumulation at the bottom of the U-shaped part is improved; by locally mechanically pressurizing the part through the forming device, the problem of inconsistent curing pressure requirements between the laminating area at the bottom of the sandwich leading edge and the surrounding sandwich area is solved, and the curing pressure is controlled in different zones; by mechanically pressurizing the bottom of the part, the curing times of the U-shaped part can be reduced, the manufacturing efficiency can be improved, and the manufacturing cost can be reduced.

[0027] (2) The steel core provides support, and the high-temperature resistant elastic material layer can be tightly attached to the bottom of the U-shaped groove in its initial state. During the part laying process, the bottom surface changes, and the high-temperature resistant elastic material layer is deformed by pressure and can continue to be tightly attached to the bottom of the part, with good pressure effect and uniform pressure; the extrusion deformation area of ​​the high-temperature resistant elastic material layer is not larger than the area of ​​the area to be pressurized to prevent affecting the non-pressurized area.

[0028] (3) Multiple supports are arranged at equal intervals to improve the uniformity of the pressure applied by the pressure block to the front edge of the U-shaped sandwich core. An avoidance gap is formed between the two inner surfaces of the arch structure and the side of the platform area, which has a simple structure; the avoidance gap can leave space for the seal to seal the edge of the U-shaped groove, which is convenient for bag making. The hole processing is convenient; the hole corresponds to the center position of the bottom of the U-shaped groove to align the pressure block with the bottom of the U-shaped groove, preventing the pressure block from pressing on the side of the U-shaped groove and affecting the quality of the side of the material to be molded. When the material to be molded is thermally cured, the resin between the layers undergoes a cross-linking reaction, and the adjacent layers will become denser and thinner as a whole. If there is no pressure to adjust the spacing, the downward adjustment amount of the clamping device will be insufficient, so that the pressure block cannot fully contact the material to be molded. By setting the pressure adjustment spacing, the clamping device can continuously drive the pressure block to transmit pressure during the entire curing process to prevent poor pressure transmission.

[0029] (4) After laying a certain number of layers of the material to be formed, a cold pumping operation is required. During the process, the pressing block is disassembled separately and placed in a cold vacuum film for use, and an isolation piece is laid on the part to prevent the pressing block from contaminating the material to be formed. The vacuuming increases the pressure of the cold vacuum film on the pressing block, and the air between the materials to be formed is discharged, so that the two adjacent layers of the materials to be formed fit tightly together. The pressing block has rigidity. Compared with cold pumping without a pressing block, the degree of compaction of the material to be formed can be improved, and the pressurization effect is better, which prevents the relative sliding between the materials to be formed during the subsequent heat curing and pressurization, resulting in wrinkles and affecting the quality of the workpiece. During the autoclave curing process of the part, the high-temperature compressed gas in the autoclave is used to pressurize and heat the pressing piece, the pressing block, the non-porous isolation film, the breathable fabric, the curing vacuum film and the material to be formed in the U-shaped groove, and the pressing block outside the vacuum part is used to locally mechanically pressurize the part. There are process materials such as a non-porous isolation film, breathable fabric, and curing vacuum film between the pressing block and the part to avoid indentations on the inner surface of the part after curing. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the structure of the leading edge of the U-shaped sandwich in the forming device;

[0031] Figure 2 Schematic diagram of the structure of the lower cover and sandwich core in the forming device;

[0032] Figure 3 Schematic diagram of the structure of the forming mold, support member and top member in the forming device;

[0033] Figure 4 Schematic diagram of the structure of the support member, the pressing member and the pressing block in the forming device;

[0034] Figure 5 Schematic diagram of the structure during cold drawing and pressing in the forming method;

[0035] Figure 6 Schematic diagram of the structure during thermal curing in the molding method.

[0036] Explanation of numbers in the figure: 1-U-shaped sandwich leading edge, 101-lower skin, 102-core material, 103-upper skin, 2-forming mold, 201-U-shaped groove, 3-pressing device, 301-support member, 302-tightening member, 303-pressing block, 4-porous isolation membrane, 5-cold vacuum membrane, 6-first sealing tape, 7-non-porous isolation membrane, 8-breathable fabric, 9-cured vacuum membrane, 10-avoidance gap, 11-pressurization adjustment distance, 12-second sealing tape. DETAILED DESCRIPTION

[0037] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0038] The purpose of the present invention is to provide a U-shaped sandwich leading edge forming device to solve the problems existing in the prior art and prevent defects such as wrinkles and poor pressure transmission at the bottom of the U-shaped sandwich leading edge.

[0039] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] The present invention provides a U-shaped sandwich leading edge forming device, such as Figures 1 to 6 As shown, it includes a forming mold 2 and a pressurizing device 3. The upper surface of the forming mold 2 is a platform area, and a U-shaped groove 201 is opened in the middle along the length direction. The surface of the U-shaped groove 201 is consistent with the aerodynamic shape surface of the leading edge 1 of the U-shaped sandwich to be formed. The pressurizing device 3 includes multiple support members 301, multiple tightening members 302 and a pressing block 303. The multiple support members 301 span the U-shaped groove 201 at the same interval and are supported on the platform area. The multiple tightening members pass through the through holes on the support members at the same interval and can move up and down. The tail ends are detachably connected to the pressing block 303 to improve the stability of the pressing block 303; the pressing block presses the bottom of the product placed in the U-shaped groove 201.

[0041] Preferably, the tightening member 302 is a half-thread bolt, and a plurality of threaded holes are provided on the pressure block 303 corresponding to the plurality of half-thread bolts. The driving end of the half-thread bolt has a thread and is threadedly connected to the pressure block 303. The portion where the half-thread bolt slides relative to the sliding portion is a smooth rod; the distance between the bottom surface of the bolt head of the half-thread bolt and the top surface of the support member 301 is a pressurized adjustment spacing 11; the pressure tank applies pressure to the bolt head of the half-thread bolt so that the half-thread bolt presses the pressure block 303 tightly.

[0042] The pressing block 303 includes a steel core and a high-temperature resistant elastic material layer. The steel core is wrapped in the high-temperature resistant elastic material layer. The outer shape of the steel core is smaller than the inner surface of the front edge 1 of the U-shaped sandwich to be formed. The shape of the crimping surface of the high-temperature resistant elastic material layer is adapted to the bottom of the U-shaped groove 201. The extrusion deformation area of ​​the high-temperature resistant elastic material layer is not larger than the area of ​​the pressurized area of ​​the material to be formed.

[0043] Preferably, a plurality of threaded holes corresponding to the half-thread bolts are provided on the steel core and are threadedly connected to the half-thread bolts.

[0044] Multiple support members 301 are arranged at equal intervals to improve the uniformity of the pressure applied by the pressure block 303 to the front edge 1 of the U-shaped sandwich core. The best effect is achieved when the spacing between two adjacent support members 301 is 150mm to 200mm, preferably 150mm. Any number of support members can be selected according to the parts to be processed, and the application range is wide.

[0045] The support member 301 is an arched structure, and an avoidance gap 10 is left between the two inner surfaces of the arched structure and the side of the platform area. The structure is simple; the avoidance gap 10 can leave space for the seal to seal the edge of the U-shaped groove 201, which is convenient for sealing. The avoidance gap 10 is 5mm to 10mm for good effect, preferably 10mm.

[0046] A hole is opened on each support member 301 at the center position corresponding to the bottom of the U-shaped groove 201 to prevent the pressing block 303 from pressing onto the side of the U-shaped groove 201 and affecting the quality of the side of the material to be formed.

[0047] When the bottom of the pressing block 303 contacts the bottom of the U-shaped groove 201 , a pressure adjustment distance 11 is provided between the top of the pressing member 302 and the upper surface of the supporting member 301 . The pressure adjustment distance 11 is 10 mm to 20 mm.

[0048] The present invention also provides a method for forming the leading edge of a U-shaped sandwich core, such as Figures 1 to 6 As shown, the following steps are included:

[0049] S1, laying the first material to be formed layer by layer in the U-shaped groove 201 provided on the forming mold 2;

[0050] S2: Lay multiple layers of the material to be formed and lay a porous isolation film 4 on the top layer. Press the pressing block 303 onto the isolation piece. Cover the pressing block 303 with a layer of cold vacuum film 5. Seal the cold vacuum film 5 and the edge of the U-shaped groove 201. Vacuum the film at room temperature to remove the air in the enclosed space enclosed by the cold vacuum film 5 and the U-shaped groove 201. Press the pressing block 303 with the cold vacuum film 5 to cold press the lower skin 101. Remove the pressing block 303 and the isolation piece.

[0051] S3, affixing a layer of adhesive film to the inner surface of the lower skin 101 obtained in step S2, adhering the bottoms of the two core materials 102 to the adhesive film, and arranging them on both sides of the inner surface of the lower skin 101, and also affixing a layer of adhesive film on the tops of the two core materials 102;

[0052] S4, the second material to be formed is laminated layer by layer along the inner surface contour of the lower skin 101 and the contour of the core material 102 obtained in step S2 to form a U-shaped sandwich leading edge 1 to be solidified;

[0053] S5, laying an isolation piece on the top layer of the U-shaped sandwich leading edge 1 to be solidified obtained in step S4, sealing the isolation piece with the edge of the U-shaped groove 201, and extracting the air in the closed space enclosed by the isolation piece and the U-shaped groove 201;

[0054] S6, installing the support member on the forming mold 2, slidingly connecting the pressing member 302 to the sliding portion, and connecting the driving end of the pressing member to the pressing block 303 to press the pressing block 303 against the isolation member in the pressurizing area;

[0055] S7, placing the entire assembly obtained in step S6 into an autoclave, and thermally curing the U-shaped sandwich leading edge 1 to be cured in step S4 to obtain a formed U-shaped sandwich leading edge 1.

[0056] Specifically, the vacuum parts in S1 to S4 include a cold vacuum film 5, the sealing parts include a first sealing tape 6, and the isolation parts include a porous isolation film 4. The cold vacuum film 5 is laid on the material to be formed in the U-shaped groove 201, the pressing block 303 and the tightening part 302 are disassembled, the pressing block 303 is pressed on the porous isolation film 4, and the cold vacuum film 5 is laid on the pressing block 303. The first sealing tape 6 seals the cold vacuum film 5 and the edge of the U-shaped groove 201 to form a cold vacuum pressurization area, which can be pressurized using atmospheric pressure after vacuuming; the porous isolation film 4 can not affect the air flow during vacuuming, thereby improving the vacuuming degree, and the cold vacuum film 5 fits tightly to the pressing block 303 to make each layer of the material to be formed.

[0057] Specifically, the vacuum parts in S5 to S7 include a cured vacuum film 9, the sealing parts include a second sealing tape 12, and the isolation parts also include a non-porous isolation film 7 and a breathable fabric 8. The non-porous isolation film 7, the breathable fabric 8 and the cured vacuum film 9 are laid in sequence on the material to be formed in the U-shaped groove 201. The second sealing tape 12 seals the cured vacuum film 9 and the edge of the U-shaped groove 201 to form a cured vacuum pressurization area, and the pressing block 303 is pressed on the cured vacuum film 9.

[0058] The forming mold 2, the pressurizing device 3, the non-porous isolation membrane 7, the breathable fabric 8, the cured vacuum membrane 9, and the second sealing tape 12 can be located in an autoclave, and the high-temperature compressed gas in the autoclave is used to pressurize and heat the tightening member 302, the pressing block 303, the non-porous isolation membrane 7, the breathable fabric 8, the cured vacuum membrane 9, and the material to be formed in the U-shaped groove.

[0059] Preferably, the core material 102 is a honeycomb core; the material to be formed is aramid prepreg; every three layers of aramid prepreg are cold pressed once, which increases the number of layers in a single cold press, reduces the number of curing times and manufacturing costs, and shortens the manufacturing cycle.

[0060] Preferably, the curing pressure in the autoclave is 0.3 MPa, the curing time is 200 minutes, and the curing temperature is 180°C.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A U-shaped sandwich leading edge forming device, characterized in that It includes a forming mold and a pressurizing device. The upper surface of the forming mold is a platform area, and a U-shaped groove is opened in the middle along the length direction. The profile of the U-shaped groove is consistent with the aerodynamic shape surface of the leading edge of the U-shaped sandwich to be formed. The pressurizing device includes multiple supports, multiple tightening members and a pressure block. The multiple supports span the U-shaped groove at the same intervals and are supported on the platform area. The multiple tightening members pass through the through holes on the supports at the same intervals and can move up and down. The tail ends thereof are detachably connected to the pressure block, and the pressure block presses the bottom of the product placed in the U-shaped groove; the through hole is opened on each support member corresponding to the center position of the bottom of the U-shaped groove.

2. A U-shaped sandwich leading edge forming device according to claim 1, characterized in that The pressing block includes a steel core and a high-temperature resistant elastic material layer. The steel core is wrapped in the high-temperature resistant elastic material layer. The outer shape of the steel core is smaller than the inner surface of the front edge of the U-shaped sandwich to be formed. The shape of the pressing surface of the high-temperature resistant elastic material layer is adapted to the bottom of the U-shaped groove. The extrusion deformation area of ​​the high-temperature resistant elastic material layer is not larger than the area of ​​the pressurized area of ​​the material to be formed.

3. A U-shaped sandwich leading edge forming device according to claim 1, characterized in that The plurality of support members are arranged at equal intervals, and the interval between two adjacent support members is 150 mm to 200 mm.

4. A U-shaped sandwich leading edge forming device according to claim 1, characterized in that The support member is an arched structure, and an avoidance gap is left between the two inner side surfaces of the arched structure and the side surface of the platform area, and the avoidance gap is 5mm to 10mm.

5. A U-shaped sandwich leading edge forming device according to claim 1, characterized in that When the bottom of the pressing block contacts the bottom of the U-shaped groove, a pressure adjustment distance is provided between the top of the pressing member and the upper surface of the supporting member, and the pressure adjustment distance is 10mm to 20mm.

6. A method for forming a U-shaped sandwich leading edge using the U-shaped sandwich leading edge forming device according to claim 1, characterized in that The following steps are involved: 6-1 Lay the first material to be formed layer by layer in the U-shaped groove opened on the forming mold; 6-2 Lay out multiple layers of the first material to be formed and lay an isolation member on the top layer. Press the pressing block in the pressurizing device onto the isolation member. Cover the pressing block with a vacuum member. Seal the vacuum member and the edge of the U-shaped groove with a sealant. Evacuate the vacuum member at room temperature to remove the air in the enclosed space enclosed by the vacuum member and the U-shaped groove. Press the pressing block with the sealant to form the lower skin with cold press. Remove the pressing block, isolation member, sealant, and vacuum member. 6-3 Apply a layer of adhesive film to the inner surface of the lower skin obtained in step 6-2, adhere the bottoms of the two core materials to the adhesive film, and arrange them on both sides of the inner surface of the lower skin, and also apply a layer of adhesive film to the tops of the two core materials; 6-4 The second material to be formed is laminated layer by layer along the inner surface contour of the lower skin and the contour of the core material obtained in step 6-2 to form a U-shaped sandwich leading edge to be cured; 6-5. Laying an isolation piece and a vacuum piece on the top layer of the front edge of the U-shaped sandwich core to be solidified obtained in step 6-4 in sequence, and sealing the vacuum piece and the edge of the U-shaped groove with a sealing piece, and extracting the air in the enclosed space enclosed by the vacuum piece and the U-shaped groove; 6-6, installing the support member on the forming mold, slidingly connecting the pressing member to the sliding portion, and connecting the driving end of the pressing member to the pressing block, and pressing the pressing block against the vacuum member in the pressurizing area; 6-7, placing the overall assembly obtained in step 6-6 into an autoclave, and thermally curing the U-shaped sandwich leading edge to be cured in step 6-4 to obtain a formed U-shaped sandwich leading edge.

7. The molding method according to claim 6, characterized in that The vacuum part includes a cold vacuum film, the sealing part includes a first sealing tape, and the isolation part includes a porous isolation film. The cold vacuum film is laid on the material to be formed in the U-shaped groove. The pressing block and the tightening part are disassembled, the pressing block is pressed on the porous isolation film, and the cold vacuum film is laid on the pressing block. The first sealing tape seals the cold vacuum film and the edge of the U-shaped groove to form a cold vacuum pressurized area.

8. The molding method according to claim 6, characterized in that The vacuum component includes a cured vacuum film, the sealing component includes a second sealing tape, and the isolation component includes a non-porous isolation film and a breathable fabric. The non-porous isolation film, the breathable fabric and the cured vacuum film are sequentially laid on the material to be formed in the U-shaped groove. The second sealing tape seals the cured vacuum film and the edge of the U-shaped groove to form a cured vacuum pressurization area, and the pressing block is pressed on the cured vacuum film.

9. The molding method according to claim 8, characterized in that The non-porous isolation film, breathable fabric, cured vacuum film, second sealing tape, forming mold and pressurizing device are placed in the autoclave together. The high-temperature compressed gas in the autoclave is used to pressurize and heat the tightening member, pressing block, non-porous isolation film, breathable fabric, cured vacuum film and the material to be formed in the U-shaped groove.

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