Composite material topological structure high wall panel forming method

Abstract

The invention belongs to the field of aeronautical composite material structure components, and relates to a forming method of a composite material topological structure high wall panel. According to the method, the problem of unconventional wall positioning is solved, the relative relation of the positions of the J-shaped high wall after the composite topological structure wallboard is formed is ensured, the problem of follow-up assembly axis deviation is solved, the coplanarity of the upper edge strips of the J-shaped high wall is ensured, the internal quality and appearance control are ensured, the precise process and tool control of composite manufacturing is realized, and the production efficiency is improved. The method is the core of technical breakthrough in the field of domestic composite material processing, and is also suitable for forming other high wall panels with different section structures.

Description

Technical Field

[0001] The invention belongs to the field of aviation composite material structural components and relates to a method for forming a high-rise wall panel with a composite material topological structure. Background Art

[0002] The integration of composite material structures has become a development need to improve structural efficiency, reduce costs and meet specific functions. In order to realize the overall structure in engineering, the overall structural design that integrates various factors is the forerunner, the material suitable for the overall structure is the basis, and the overall structural manufacturing that interacts with the design is the key. The idea of ​​material / design / manufacturing integration runs through the whole process. The overall structure of composite materials can be used in civil products such as aviation, aerospace, ships, and power transmission. The overall structure of general wall panels mainly refers to the height of long stringers and reinforcements is not very large, and beams, ribs and other structures are required to form a box-segment structure. The overall structural forming method of general wall panels is mature and stable. According to the overall shape, it can be divided into flat wall panels, curved wall panels and cylindrical wall panels. According to the cross-sectional shape of long stringers and reinforcements, it can be divided into T-shaped, J-shaped, U-shaped, I-shaped and other forms. The overall structure of box-segment wall panels mainly refers to the long stringers and reinforcements being replaced by longitudinal walls, and the box-segment structure can be formed without beams, ribs and other structures. As composite materials develop towards integration, large-scale and complexity, the structure of composite reinforced wall panels is becoming more and more complex and larger in size. The pressure transmission during the molding process becomes more complicated, resulting in the displacement or deflection of ribs such as high walls during the molding process, making it difficult to ensure the accuracy of the axis and control the bonding quality.

[0003] The topology-size joint optimization method hierarchically explores the optimal internal layout, composite material size and laying method of composite reinforced wall panels, changing the traditional method of parallel ribs / high wall axis of traditional wall panels and adding vertical ribs / skeleton. The integration of composite topology high wall panels effectively reduces the number of component assembly and fasteners, achieves a good weight reduction effect, simplifies the assembly process, and makes the assembly jig simpler. The composite topology high wall panel structure consists of a skin and a high wall. The high wall section can be T-shaped, J-shaped, U-shaped, I-shaped, etc. Figure 1 The J-shaped high wall topological structure panel is divided into two groups. The axis surfaces of the two groups of high walls are not parallel and have a certain angle. The process control and combined coordinated positioning are the difficulties in the integrated manufacturing of parts. The accuracy of the upper edge surface of the J-shaped high wall and the angle between the wall itself and the skin affects the assembly with other parts. In order to improve production efficiency and ensure the position accuracy requirements, a tooling positioning method is designed to ensure the position accuracy of the topological structure wall, which can avoid the position deviation of the wall during the forming process. The wall position control is simple, which greatly improves the production efficiency and ensures the quality of the product. This method is suitable for the forming of composite material topological structure high wall panels with different high wall sections. Summary of the invention

[0004] The present invention is applicable to a molding method of a composite material topological structure high-rise wall panel, and proposes a molding method of a composite material high-rise wall panel with a simple molding process and easily controlled high wall axis and bonding quality. The technical problem to be solved is the precise positioning and quality control problem of the topological structure wall. The method also effectively solves the control and inspection of the wall height, so that the overall part molding accuracy is high, laying a good foundation for precise assembly. It is a key method for improving the integrated manufacturing level of aircraft composite material parts, and the use of this method also effectively improves production efficiency.

[0005] The technical solution of the present invention is as follows:

[0006] The process of the present invention is as follows Figure 2 As shown, there are two methods, one is a method of bonding the uncured skin and the cured wall for co-curing, and the other is a method of secondary bonding the cured skin and the cured wall. The difference between the two methods is whether the skin is cured separately. The invention is effective for both curing methods, and the molding method thereof includes the following steps:

[0007] The forming method of the composite material topological structure high wall panel comprises the following steps:

[0008] Step 1: High wall preparation: Cut the raw materials of the high wall, stack them, package them, and solidify them. After solidification, remove the vacuum bag, demould the high wall, and then process the shape. Reserve process ears and positioning holes in the length direction for assembly and positioning. They can be removed by machining after assembly.

[0009] The second step is skin preparation: skin raw material cutting, stacking and packaging. The skin is stacked manually or automatically. When the bonding co-curing molding method is used, the skin is compacted; when the secondary bonding molding method is used, the skin is packaged and cured, and the bonding surface is polished and cleaned after curing.

[0010] The third step is high wall pre-assembly: accurately position the positioning beam and multiple positioners, place the high walls one by one in their corresponding positions in sequence, use a feeler gauge to check the gap between the high wall and the skin, and stick a film on the high wall skin surface according to the checked size, use an isolation film for isolation, and encapsulate the assembly;

[0011] Step 4: High wall verification: Use the vacuum bag-autoclave method to verify the fit of the high wall and skin bonding area;

[0012] Step 5: Inspection and treatment: Inspect the upper surface of the high wall, inspect the surface where the high wall and the skin meet, paste the film for compensation according to the actual situation, and perform curing and packaging;

[0013] Step 6: Combined curing: According to the curing parameter settings of the selected materials, enter the autoclave for vacuuming, heating and pressurizing to complete the bonding and curing;

[0014] Step 7, cleaning and inspection: After curing is completed, remove the peelable protective layer, isolation film, breathable felt, vacuum bag, etc., and do not demold the entire part first;

[0015] Step 8, high wall inspection: Use matching inspection to inspect the high wall axis and the upper surface of the high wall;

[0016] Step 9, demoulding: remove the positioning device of the combined tooling and remove the workpiece from the wall panel forming tooling;

[0017] Step 10: Shape processing and inspection: Perform shape processing on the wall panels and check the internal quality and shape dimensions.

[0018] in, Figure 3 The schematic diagram of a forming tool according to the invention is shown. The topological structure high wall panel forming tool is a frame structure, all made of metal materials. The metal forming tool has good surface finish, excellent size control and long service life. The precision of the positioning beam and positioning assembly effectively ensures the accuracy of the absolute position and relative position of the high wall; the forming tool can realize three main functions: laying and curing of the skin, positioning combination and bonding of the high wall, and detection of the position and height of the high wall after curing.

[0019] A forming tool comprises a forming tool main structure, a main positioning beam, a positioning pin of the main positioning beam, a positioning base of the main positioning beam, a high wall auxiliary positioning base and a high wall positioner;

[0020] The main structure of the molding tool is a frame type, and the mold surface of the main structure of the molding tool is the outer shape surface of the high wall panel of the composite material topological structure. The mold surface should ensure the air tightness during the curing, heating and pressurization after encapsulation, including the skin laying area and the furnace parts placement area. The positioning pins of the main positioning beam, the positioning base of the main positioning beam and the high wall auxiliary positioning base are integrated with the main structure and are processed using the same processing reference as the mold surface. They are used for the main positioning beam and the high wall auxiliary positioning, wherein the main positioning beam has two positioning pins, one end of which is a circular positioning pin and the other end is an oblong positioning pin;

[0021] The main positioning beam is a frame-type bridge-shaped structure, spanning the main structure of the molding tooling. The main positioning beam is detachable and can be precisely positioned on the main structure of the molding tooling. It is used to position one side of the high wall. The main positioning beam of the tooling and the skin frame are positioned using positioning pins at both ends of the frame. To facilitate disassembly and installation, one end of the positioning pin of the main positioning beam in the main structure of the molding tooling is a circular positioning pin, and the other end is an oblong positioning pin, which is also conducive to expansion coordination and stress release at the curing temperature. The main positioning beam hoisting ring is used for the hoisting of the main positioning beam. Multiple J-shaped high-wall auxiliary positioning devices are installed on the main positioning beam. Each J-shaped high-wall auxiliary positioning device is positioned with 2 pins and connected to the main positioning beam with 2 bolts.

[0022] The high wall locators are all removable and accurately positioned. One end is positioned on the main positioning beam and is positioned using two notched pins and a metal insert. The other side is positioned on a J-shaped high wall auxiliary positioning device. An L-shaped J-shaped high wall auxiliary positioning device is used to first position it in the main structure of the forming tooling and uses notched pins and a metal insert. The J-shaped high wall web surface is fitted with the high wall locator to determine the relative position of the high wall to the skin.

[0023] The positioning method of the upper edge strip inspection card is the same as that of the high wall positioner. It can be used to inspect the upper edge strip after the J-shaped high wall is assembled, and can also be used to inspect the upper edge strip of the high wall before the high wall panel is demoulded after the high wall positioner is removed.

[0024] Main positioning beam Figure 4 After the positioning beam is positioned, the positioning seat and the wall positioning assembly are installed in sequence. The positioning seats are designed to be located at both ends of the wall. Figure 5 .

[0025] The solidified J-shaped high wall is placed according to the position of the positioning components on the positioning beam, and the outer web surface of the J-shaped high wall is closely attached to the positioning components to ensure that there is no gap. The positioning device is removed during packaging. Figure 6 .

[0026] Beneficial effects of the present invention:

[0027] The present invention solves the problem of positioning unconventional walls, ensures the relative position of the J-shaped high wall after the composite material topological structure wall panel is formed, is beneficial to the subsequent assembly axis offset problem, ensures the coplanarity of multiple J-shaped high wall upper edge strips, ensures internal quality and appearance control, and realizes precise process and tooling control of composite material manufacturing. It is the core of technological breakthroughs in the field of domestic composite material processing, and the method is also applicable to the forming of other high wall panels with different cross-sectional structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of a composite material topological structure high wall panel;

[0029] Figure 2 is a flow chart of the present invention;

[0030] Figure 3 It is a schematic diagram of the molding tooling;

[0031] Figure 4 This is a schematic diagram of the main positioning beam;

[0032] Figure 5 The schematic diagram of the positioning seats designed at both ends of the wall;

[0033] Figure 6 Schematic diagram of removing the positioning device for packaging.

[0034] In the figure: 1-skin; 2-J-shaped high wall; 3-main structure of the forming tooling; 4-main positioning beam; 5-locating pin of the main positioning beam; 6-locating base of the main positioning beam; 7-high wall auxiliary positioning base; 8-high wall locator; 9-furnace part position; 10-positioning beam body; 11-locating pin hole; 12, J-shaped high wall auxiliary positioning device; 13, lifting ring; 14-side positioning pin; 15-J-shaped high wall auxiliary positioning device; 16-J-shaped high wall locator; 17-J-shaped high wall locator lifting ring; 18-insert; 19-upper edge strip inspection card. DETAILED DESCRIPTION

[0035] The implementation and use of the preferred embodiments of the present invention are discussed in detail below in conjunction with the accompanying drawings. However, it should be understood that the specific embodiments discussed are merely illustrative of specific ways of implementing and using the present invention, and do not limit the scope of the present invention. When describing the structural positions of various components, such as up, down, left, right, top, bottom, etc., the expressions of directions are not absolute, but relative. When the various components are arranged as shown in the figure, these directional expressions are appropriate, and when the positions of the various components in the figure change, these directional expressions also change accordingly. Figures 1 to 6 As shown in the figure, the method for bonding and co-curing the composite material topological structure high wall panels according to the present invention is achieved by the following steps:

[0036] (1) High wall preparation: The raw materials of the J-shaped high wall are cut, the tooling is a frame structure, the web C layer is the mold surface, and the main part of the tooling molding is "h"-shaped. The process from the "h"-shaped tooling to the "J"-shaped high wall parts is stacked-assembled-packaged-cured on the molding tooling. After curing, the vacuum bag is removed, and the high wall is demolded and processed for appearance. Ears and positioning holes are reserved in the length direction for assembly positioning. The positioning holes are elliptical holes, which can be used for positioning in the length direction and also meet the requirements of the bonding between the high wall and the skin during curing. After the J-shaped high wall passes the internal quality inspection and appearance inspection, the bonding part with the skin will be polished and cleaned for use.

[0037] (2) Skin laying: The skin is laid on the topological structure wall panel forming mold. It can be laid by automatic tape laying, automatic wire laying or manual method.

[0038] (3) Skin packaging and compaction: After the skin is laid up, a peelable protective layer, isolation film, process cover (as needed), air guide material and vacuum bag can be placed on the surface of the skin for packaging and hot compaction in an autoclave. The hot compaction parameters can be set according to the corresponding prepreg parameters. The thickness of the skin after compaction is similar to the thickness after curing, and the skin surface is regular, reducing the risk of skin sinking at high walls after curing.

[0039] (4) Positioning and assembling of high wall on skin: Guided by the positioning pin, the positioning beam and skin frame tooling are placed and positioned by hoisting, the positioning seat is installed according to the pin, the wall positioning assembly is connected to the positioning seat, and the J-shaped high wall is placed on the corresponding positioner in sequence. The J-shaped high wall is pressed by hand to make it as close to the skin surface as possible. Under finger pressure, a feeler gauge is used to check the gap. When the gap is ≤0.15mm, it is the optimal zone. When the gap is ≥0.2mm, the corresponding interval is recorded, and adhesive film is placed on the bonding surface of the high wall. One layer is placed in the optimal zone, and the remaining areas are compensated with adhesive film according to the gap size.

[0040] (5) Packaging verification: Use an isolation film to isolate the high wall and skin at the bonding film position, package the vacuum bag, and put it into the autoclave for verification. The heating temperature into the tank is much lower than the curing temperature. The heating time is 30 minutes and the autoclave pressure is 0.3MPa-0.5MPa. After verification, remove the vacuum bag and other auxiliary materials, check the film position, and fill the insufficient area with film.

[0041] (6) Curing and packaging: Remove the isolation film on the bonding surface, and position the high wall according to the positioning method in step (4). Cut the non-porous isolation film and breathable felt into strips, and cover them in the middle skin position of the two high walls in the length direction. Thinner breathable materials can be placed in the high wall web and upper edge strip area. The strip-shaped non-porous isolation film overlaps each other to prevent resin overflow, and the strip-shaped breathable felt overlaps each other to ensure the connection of the air guide path, and prevent the non-porous isolation film and breathable felt from bridging when the whole piece is placed. Place air-conducting materials around the parts and connect them to the breathable felt, and finally use sealing strips to perform vacuum bag packaging.

[0042] (7) Curing: Check the vacuum bag for vacuum leakage before entering the tank. After meeting the requirements, enter the autoclave for curing. The curing parameters refer to the parameters of the skin prepreg and film materials. The curing pressure is optional.

[0043] 0.6MPa-0.8MPa.

[0044] (8) Cleaning and inspection: After curing is completed, remove the peelable protective layer, isolation film, breathable felt, vacuum bag, etc., and do not demold the entire part;

[0045] (9) High wall inspection: Use matching inspection to inspect the high wall axis and the surface profile of the high wall. Generally, the high wall axis is allowed to be ±1mm, and the high wall edge strip surface is allowed to be 0 to -0.5mm;

[0046] (10) Demolding: dismantle the positioning device of the combined tooling and remove the topological structure high wall panel from the wall panel forming tooling;

[0047] (11) Shape processing and inspection: The wall panels are processed by manual cutting or CNC processing methods, and the internal quality and shape dimensions are inspected.

[0048] The technical contents and technical features of the specific embodiments of the present invention have been disclosed above. However, it can be understood that under the creative ideas of the present invention, those skilled in the art can make various changes and improvements to the above-mentioned various features and combinations of features not explicitly shown here, but they all belong to the protection scope of the present invention. The description of the above embodiments is exemplary rather than restrictive, and the protection of the present invention is limited to the following aspects:

Claims

1. A method for forming a composite material topological structure high-rise wall panel, characterized in that: Here are the steps: Step 1: High wall preparation: Cut the raw materials of the high wall, stack them, package them, and solidify them. After solidification, remove the vacuum bag, demould the high wall, and then process the shape. Reserve process ears and positioning holes in the length direction for assembly and positioning. They can be removed by machining after assembly. The second step is skin preparation: skin raw material cutting, laying-up and packaging. The skin is laid-up manually or automatically. The third step is high wall pre-assembly: accurately position the positioning beam and multiple positioners, place the high walls one by one in their corresponding positions in sequence, use a feeler gauge to check the gap between the high wall and the skin, and stick a film on the high wall skin surface according to the checked size, use an isolation film for isolation, and encapsulate the assembly; Step 4: High wall verification: Use the vacuum bag-autoclave method to verify the fit of the high wall and skin bonding area; Step 5: Inspection and treatment: Inspect the upper surface of the high wall, inspect the surface where the high wall and the skin meet, paste the film for compensation according to the actual situation, and perform curing and packaging; Step 6: Combined curing: According to the curing parameter settings of the selected materials, enter the autoclave for vacuuming, heating and pressurizing to complete the bonding and curing; Step 7, cleaning and inspection: After curing is completed, remove the peelable protective layer, isolation film, breathable felt, vacuum bag, etc., and do not demold the entire part first; Step 8, high wall inspection: Use matching inspection to inspect the high wall axis and the upper surface of the high wall; Step 9, demoulding: remove the positioning device of the combined tooling and remove the workpiece from the wall panel forming tooling; Step 10: Shape processing and inspection: Perform shape processing on the wall panels and check the internal quality and shape dimensions.

2. The method for forming a composite material topological structure high-rise wall panel according to claim 1, characterized in that: In the second step, when the adhesive bonding co-curing molding method is adopted, the skin is compacted; when the secondary adhesive bonding molding method is adopted, the skin is packaged and cured, and the adhesive surface is polished and cleaned after curing.

3. The method for forming a composite material topological structure high-rise wall panel according to claim 1 or 2, characterized in that: In the eighth step, the high wall axis and the upper surface profile of the high wall are checked using a matching test, and the high wall axis is allowed to be ±1mm, and the high wall edge strip profile is allowed to be 0 to -0.5mm.

4. The method for forming a composite material topological structure high-rise wall panel according to claim 1 or 2, characterized in that: The molding tool comprises a molding tool main structure (3), a main positioning beam (4), a positioning pin (5) of the main positioning beam, a positioning base (6) of the main positioning beam, a high wall auxiliary positioning base (7), a high wall positioner (8), a J-shaped high wall auxiliary positioning device (12) and an upper edge strip inspection card (19); The main structure (3) of the molding tool is a frame type, and the mold surface of the main structure of the molding tool is the outer shape surface of the high wall panel of the composite material topological structure. The mold surface should ensure the air tightness during curing, heating and pressurization after encapsulation, including the skin laying area and the furnace parts placement (9) area. The positioning pin (5) of the main positioning beam, the positioning base (6) of the main positioning beam and the high wall auxiliary positioning base (7) are integrated with the main structure and are processed using the same processing reference as the mold surface. They are used for the main positioning beam and the high wall auxiliary positioning, wherein the main positioning beam has two positioning pins (5), one end of which is a circular positioning pin and the other end is an oblong positioning pin.

5. The method for forming a composite material topological structure high-rise wall panel according to claim 4, characterized in that: The main positioning beam (4) is a frame-type bridge-shaped structure, spanning the main structure (3) of the molding tool. The main positioning beam is detachable and can be accurately positioned on the main structure (3) of the molding tool, and is used for positioning on one side of a high wall. The main positioning beam (4) of the tool and the skin frame are positioned using positioning pins at both ends of the frame. To facilitate disassembly and installation, one end of the positioning pin (5) of the main positioning beam in the main structure (3) of the molding tool is a circular positioning pin, and the other end is an oblong positioning pin. The main positioning beam hoisting ring (13) is used for hoisting the main positioning beam.

6. The method for forming a composite material topological structure high-rise wall panel according to claim 4, characterized in that: One end of the high wall positioner (8) is positioned on the main positioning beam, and is positioned by two notched pins and a metal insert (18), and the other side is positioned on the J-shaped high wall auxiliary positioning device (15). The L-shaped J-shaped high wall auxiliary positioning device (15) is first positioned in the main structure (3) of the forming tooling, and is positioned by a notched pin and a metal insert (18); the J-shaped high wall web surface is fitted with the high wall positioner (8) to determine the relative position of the high wall in the skin.

7. The method for forming a composite material topological structure high-rise wall panel according to claim 4, characterized in that: The positioning method of the upper edge strip inspection card plate (19) is the same as that of the high wall positioner (8).

8. The method for forming a composite material topological structure high-rise wall panel according to claim 4, characterized in that: The J-shaped high wall auxiliary positioning device (12) is installed on the main positioning beam, and each J-shaped high wall auxiliary positioning device (12) is positioned by two pins and connected to the main positioning beam by two bolts.

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