A carbon fiber H-beam forming tool and process method

Abstract

The application provides a carbon fiber H-beam forming tool and process method, and belongs to the field of civil aviation part forming processing. The left cover plate mold and the right cover plate mold in the forming tool are clamped from both sides after clamping the H-beam web, and are positioned and clamped between the frame type lower mold and the frame type upper mold. The H-beam web is formed in the form of being perpendicular to the horizontal plane, so as to reduce the demolding difficulty of horizontal placement. The forming process method steps are as follows: firstly, the upper and lower C-type webs are laid by using a laying mold, and are attached to each other; the triangular area formed after the attachment is filled and compacted; the side edge strip is laid; the left and right cover plate molds are clamped after demolding the laying mold; the left and right cover plate molds are positioned and clamped in the upper and lower molds; and curing forming is carried out. While ensuring sufficient rigidity, strength, stability and accuracy, the application effectively reduces defects such as curing deformation, delamination and thickness out-of-tolerance, and greatly increases the manufacturing success rate.

Description

Technical Field

[0001] The invention belongs to the field of civil aviation parts forming and processing, and relates to a carbon fiber H-beam forming tool and a process method. Background Art

[0002] With the deepening of research in composite materials technology, their application in the aviation field has become increasingly widespread. Currently, mainstream international aircraft manufacturers such as Boeing and Airbus have adopted composite materials, which are highly fuel-efficient, as one of the primary materials for aircraft fuselage structures. H-beam structures are the most commonly used structural form in fuselage and wing structures, and are widely used in the world's most advanced civil aircraft models. H-beam structures consist of a central web and two side flanges, forming two C-shaped internal cavities. The web has one wide end and one narrow end, with one flange generally convex and the other concave. H-beam structures developed earlier abroad, with rich processing experience and advanced manufacturing technology. However, domestically, the development of H-beam structures is relatively slow, with unstable manufacturing quality, high efficiency and low costs, and the lack of technology seriously restricting productivity.

[0003] Traditional carbon fiber H-beam molding methods utilize horizontal, concave-convex molds for compression molding. After stacking the upper and lower molds, the upper mold is flipped over and secured with bolts and dowel pins. The upper and lower molds are made of metal molds, and demolding after curing can easily release residual stress, leading to part deformation. Deformation analysis and prediction methods consume significant time and materials. Demolding the lower mold from horizontal tooling is difficult, especially for closed-angle structures. Forced demolding can exacerbate stress fluctuations, resulting in significant deformation that is difficult to control. Summary of the Invention

[0004] The present invention aims to provide a carbon fiber H-beam forming tool and process to address the difficulty of demolding such parts and internal defects such as delamination and thickness tolerances during the molding process, thereby reducing tooling cost and weight. The present invention utilizes a newly designed tooling structure and forming process to effectively reduce demolding difficulties, minimize stress and deformation caused by material and structure, effectively control defects such as delamination and thickness tolerances, and significantly increase the manufacturing success rate.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A carbon fiber H-beam forming tool comprises: a frame-type lower mold 1, a wide-end positioning support block 2, a narrow-end positioning support block 3, a frame-type upper mold 4, a left cover mold 5, and a right cover mold 6.

[0007] The lower part of the frame-type lower mold 1 is a frame structure, and the upper part is an upper template fixedly connected to the frame structure. The lower frame structure is welded together by longitudinal and transverse partitions. The longitudinal and transverse partitions have large square openings and oblique rib openings. Long circular holes are opened at the contact parts of the longitudinal and transverse partitions with the upper template to increase the ventilation effect while reducing the overall weight. The upper template adopts a solid plate, and its profile is consistent with the convex profile of the H beam 7. The two ends of the upper surface of the upper template are fixedly connected with a wide end positioning support block 2 and a narrow end positioning support block 3, respectively. Among them, the wide end positioning support block 2 is provided with a transverse positioning hole for connecting and fixing with the ear piece on the wide end of the H beam 7. The narrow end positioning support block 3 is a triangular positioning block. The tip of the triangular positioning block The end face is used to position with the narrow end face of the H-beam 7, and the top of the two positioning support blocks are provided with vertical circular holes for quick positioning and assembly; the four corners of the upper template of the frame-type lower mold 1 are provided with positioning holes, which are used as the positioning reference for the forming tooling; a plurality of limit blocks are provided on the upper template for positioning and limiting the left cover plate mold 5 and the right cover plate mold 6 with the H-beam 7 clamped thereon, and the limit blocks are arranged on both sides of the length direction of the H-beam 7. The limit block close to the wide end of the H-beam 7 is set at the 20mm margin line of the part, and the limit block close to the narrow end of the H-beam 7 is set 1mm outwardly along the 20mm margin line of the part, and the limit block is higher than the sum of the thickness of the edge strip of the H-beam 7 and the thickness of the edge strip of the left cover plate mold 5 or the right cover plate mold 6.

[0008] The left cover plate mold 5 and the right cover plate mold 6 are both C-shaped structures, consisting of a support plate in the middle and edge strips on both sides. They are made of carbon fiber material consistent with the H-beam 7. The left and right cover plate molds are respectively clamped on both sides of the web surface of the H-beam 7. The lengths of the two are set according to the length of the H-beam 7. The profiles of the two cooperate with the upper and lower C-shaped inner cavities of the H-beam 7 to play a role in pressure equalization and support during the curing process; the height of the edge strips on both sides of the left and right cover plate molds is greater than the height of the edge strips of the H-beam 7 to ensure that the pressure surface is completely covered. After assembling the H-beam 7, the outer end faces of the edge strips on both sides of the left and right cover plate molds do not exceed the 20mm margin line of the part; the outer surfaces of the edge strips on both sides of the left and right cover plate molds are made with part shape edge lines.

[0009] The upper part of the frame-type upper mold 4 also adopts a frame structure, and the lower part is a lower template fixedly connected to the frame structure. The frame structure is composed of longitudinal and transverse partitions, which are welded as a whole. The transverse partitions are in contact with the inner surface of the lower template for support, increasing rigidity conduction and heat conduction. The lower template adopts a solid plate, and the profile is consistent with the concave profile of the H-beam 7. A plurality of limit blocks are provided on the lower surface of the lower template, and their positions correspond to the limit blocks on the frame-type lower mold 1, which jointly realize the limitation of the left and right cover plate molds and the H-beam 7. In order to prevent the parts from tilting during the solidification process, the limit blocks on the lower template are higher than the limit blocks on the frame-type lower mold 1; positioning blocks are provided at both ends of the bottom surface of the lower template, and positioning pins are set on the bottom surfaces of the positioning blocks. The positioning pins are inserted into the circular holes on the top of the positioning support blocks at both ends of the frame-type lower mold 1, which are used for rapid positioning and loading and unloading of the frame-type upper mold 4 and the frame-type lower mold 1, and the two are clearance-matched.

[0010] Furthermore, the upper template of the frame-type lower mold 1 and the lower template of the frame-type upper mold 4 are both made of invar steel to ensure that the expansion coefficient during the molding process is consistent with the H-beam 7 to reduce stress deformation.

[0011] Furthermore, the roughness requirement for the working surface of the forming tooling is Ra1.6.

[0012] A carbon fiber H-beam forming process method, the process method comprising the following steps:

[0013] Step 1: Use the upper and lower web layup dies to lay up the upper and lower C-shaped webs, respectively. During layup, the first layer of prepreg is laid and then compacted at room temperature. Each subsequent layer of prepreg is compacted at room temperature. After each layer, the part blank is trimmed using the upper and lower web layup dies, ultimately forming C-shaped webs a 8 and b 9. During layup, tabs and holes are reserved at the wide ends of the webs for flipping and positioning.

[0014] Step 2: Lift and flip the upper web paving mold, combine the upper and lower web paving molds, and hit the upper web paving mold with a rubber hammer to eliminate the combined gap. At this time, the C-shaped web a 8 and the C-shaped web b 9 are butt-jointed.

[0015] Step 3: Use a heated platform to roll the 0° fiber into two cylindrical prepreg rods 12 on the left and right. Fill the prepreg rods 12 into the triangular area formed by the butt joint of the C-shaped web a 8 and the C-shaped web b 9 and compact them. After heating and flattening with an iron, vacuum compaction is performed. The iron temperature is not higher than 93°C.

[0016] Step 4: Use the positioning lines and marking lines on both sides of the upper and lower web lay-up molds to co-position the side edge strips a10 and b11, and start laying from the wide end to obtain the part blank.

[0017] In step 5, the part blank is separated from the upper and lower web layup molds. The part blank is then assembled with the left and right cover molds. The blank is trimmed according to the contour lines of the left and right cover molds. The part blank and the left and right cover molds are then transferred to the frame-type lower mold 1. The transverse positioning holes on the wide-end positioning support block 2 are connected to the ear holes reserved at the wide end of the part blank. The part blank is positioned with the narrow end surface of the web aligned with the triangular tip of the narrow-end positioning support block 3. After the part blank is positioned, the frame-type upper mold 4 is positioned and capped. The left and right cover molds holding the part blank are restrained within the limit blocks on the frame-type upper mold 4. The web surface of the H-beam 7 is formed perpendicular to the horizontal plane to reduce the difficulty of demolding when placed horizontally.

[0018] Step 6: After the part blank is clamped, it is solidified and formed to obtain the final H-beam 7.

[0019] The beneficial effects of the present invention are:

[0020] The present invention is manufactured through molding combined tooling and process methods, which effectively reduces defects such as curing deformation, delamination and thickness deviation while ensuring sufficient rigidity, strength, stability and precision, thereby greatly increasing the manufacturing success rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is an isometric diagram of the entire forming tooling.

[0022] Figure 2 It is a cross-sectional view of the H-beam installed in the left and right cover plate mold clamps.

[0023] Figure 3 This is a cross-sectional diagram of the part blank being formed.

[0024] In the figure: 1 frame-type lower mold; 2 wide-end positioning support block; 3 narrow-end positioning support block; 4 frame-type upper mold; 5 left cover mold; 6 right cover mold; 7 H beam; 8 C-type web a; 9 C-type web b; 10 side edge strip a; 11 side edge strip b; 12 cylindrical prepreg rod. DETAILED DESCRIPTION

[0025] The following is a clear and complete description of the technical solution of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments improved or adjusted by ordinary technicians in this field fall within the scope of protection of the present invention.

[0026] like Figure 1-2 As shown, a carbon fiber H-beam forming tooling includes: a frame-type lower mold 1, a wide-end positioning support block 2, a narrow-end positioning support block 3, a frame-type upper mold 4, a left cover mold 5, and a right cover mold 6.

[0027] The lower part of the frame-type lower mold 1 is a frame structure, and the upper part is an upper template fixedly connected to the frame structure. The lower frame structure is welded together by longitudinal and transverse partitions. The wall thickness of the longitudinal and transverse partitions is 10mm, with large square openings and oblique rib openings. Long circular holes are opened at the contact parts of the longitudinal and transverse partitions and the upper template to increase the ventilation effect while reducing the overall weight. The upper template adopts a solid plate with a wall thickness of 10mm. Its profile is consistent with the convex profile of the H beam 7. A plurality of φ10mm bolt holes are formed at both ends of the upper surface of the upper template; the wide end positioning support block 2 and the narrow end positioning support block 3 are respectively fixed to the bolt holes at both ends of the upper surface of the upper template by hexagonal bolts, wherein the wide end positioning support block 2 is provided with a transverse positioning hole for connecting and fixing with the ear piece on the wide end of the H beam 7, and the narrow end positioning support block 3 is a triangular positioning block. The tip end face of the triangular positioning block is used to connect with the H The narrow end of beam 7 is positioned, and the tops of the two positioning support blocks are equipped with vertical circular holes for quick positioning and assembly. The four corners of the upper template of the frame-type lower mold 1 are equipped with positioning holes, which serve as positioning references for the forming tooling. The upper surface of the upper template of the frame-type lower mold 1 is designed with the part outline, a 20mm allowance line, and sunken transition zone marking lines, with a depth of 0.5mm and a width of 0.3mm. The upper template is equipped with six limit blocks to position and limit the left and right cover molds 5 and 6, which are clamped with H-beam 7. The limit blocks are arranged along the length of H-beam 7, three on each side. The limit block near the wide end of H-beam 7 is set at the 20mm allowance line of the part, and the limit block near the narrow end of H-beam 7 is offset 1mm outward from the 20mm allowance line of the part. The limit blocks are higher than the sum of the thickness of the flange of H-beam 7 and the flange thickness of the left or right cover mold 5 or 6. The positioning support blocks at both ends are fixed.

[0028] The left cover plate mold 5 and the right cover plate mold 6 are both C-shaped structures, consisting of a support plate in the middle and edge strips on both sides. They are made of carbon fiber material consistent with the H-beam 7. The left and right cover plate molds are respectively clamped on both sides of the web surface of the H-beam 7. The lengths of the two are set according to the length of the H-beam 7. The profiles of the two cooperate with the upper and lower C-shaped inner cavities of the H-beam 7 to play a role in pressure equalization and support during the curing process. The thickness of the left and right cover plates is 2.64mm, which ensures its functionality while reducing weight; the height of the edge strips on both sides of the left and right cover plate molds is greater than the height of the edge strips of the H-beam 7 to ensure that the pressure surface is completely covered. After assembling the H-beam 7, the outer end faces of the edge strips on both sides of the left and right cover plate molds do not exceed the 20mm margin line of the part; the outer surfaces of the edge strips on both sides of the left and right cover plate molds are made with part shape edge lines.

[0029] The upper part of the frame-type upper mold 4 also adopts a frame structure, and the lower part is a lower template fixedly connected to the frame structure. The frame structure is composed of longitudinal and transverse partitions, which are welded as one. The transverse partitions are in contact with the inner profile of the lower template to support and increase rigidity conduction and heat conduction. The lower template adopts a solid plate, and the profile is consistent with the concave profile of the H-beam 7. The lower surface of the lower template is provided with 6 limit blocks, and their positions correspond to the limit blocks on the frame-type lower mold 1, which jointly realize the limitation of the left and right cover plate molds and the H-beam 7. In order to prevent the parts from tilting during the solidification process, the limit blocks on the lower template are higher than the limit blocks on the frame-type lower mold 1; positioning blocks are provided at both ends of the bottom surface of the lower template, and positioning pins are set on the bottom surfaces of the positioning blocks. The positioning pins are inserted into the top circular holes of the positioning support blocks at both ends of the frame-type lower mold 1, which are used for rapid positioning and loading and unloading of the frame-type upper mold 4 and the frame-type lower mold 1. The two are clearance-matched, and the clearance is 0.5mm.

[0030] The present invention also provides a carbon fiber H-beam forming process method, which includes the following steps:

[0031] 1. Use the upper and lower web layup dies to lay up the upper and lower C-shaped webs, respectively. During layup, compact the first layer of prepreg at room temperature. Then, compact each three layers at room temperature. After each layer, trim the part blank using the upper and lower web layup dies, ultimately forming C-shaped webs a 8 and b 9. During layup, retain tabs and holes at the wide ends of the webs for flipping and positioning.

[0032] 2. Lift and turn over the upper web paving mold, combine the upper and lower web paving molds, and hit the upper web paving mold with a rubber hammer to eliminate the combination gap. At this time, the C-shaped web a 8 and the C-shaped web b 9 are butt-jointed.

[0033] 3. Use a heated platform to roll the 0° fiber into two cylindrical prepreg rods 12 on the left and right. Fill the prepreg rods 12 into the triangular area formed by the butt joint of the C-shaped web a 8 and the C-shaped web b 9 and compact them. After heating and flattening with an iron, vacuum compaction is performed. The iron temperature should not exceed 93°C.

[0034] 4. Use the positioning lines and marking lines on both sides of the upper and lower web layup molds to locate and lay up the side edge strips a 10 and b 11, and start laying from the wide end to obtain the part blank, as shown in the figure. Figure 3 shown.

[0035] 5. Separate the part blank from the upper and lower web layup molds, assemble the part blank with the left and right cover molds, trim the blank according to the part outline of the left and right cover molds, and transfer the part blank and the left and right cover molds to the frame-type lower mold 1. Connect the transverse positioning holes on the wide-end positioning support block 2 to the ear holes reserved for the wide end of the part blank. Position it with the limit blocks, and align the narrow end of the web of the part blank with the triangular tip of the narrow-end positioning support block 3. After the part blank is positioned, position and cover it with the frame-type upper mold 4, and confine the left and right cover molds with the part blank within the limit blocks on the frame-type upper mold 4. Forming is performed with the web surface of the H-beam 7 perpendicular to the horizontal plane to reduce the difficulty of demolding when placed horizontally.

[0036] 6. After the part blank is clamped, it is solidified and formed to obtain the final H-beam 7.

[0037] The above-described embodiments merely express the implementation methods of the present invention, but should not be understood as limiting the scope of the patent of the present invention. It should be pointed out that for those skilled in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A carbon fiber H-beam forming tool, characterized in that: The molding tool comprises: a frame-type lower mold (1), a wide-end positioning support block (2), a narrow-end positioning support block (3), a frame-type upper mold (4), a left cover mold (5), and a right cover mold (6); The lower part of the frame-type lower mold (1) is a frame structure, and the upper part is an upper template fixedly connected to the frame structure. The upper template adopts a solid plate, and its profile is consistent with the convex profile of the H beam (7). The two ends of the upper surface of the upper template are respectively fixedly connected with a wide end positioning support block (2) and a narrow end positioning support block (3), wherein the wide end positioning support block (2) is provided with a transverse positioning hole for connecting and fixing with the ear piece on the wide end of the H beam (7), and the narrow end positioning support block (3) is a triangular positioning block. The tip end face of the triangular positioning block is used for positioning with the narrow end face of the H beam (7), and the top ends of the two positioning support blocks are provided with vertical circular holes for rapid positioning and assembly; a plurality of limit blocks are provided on the upper template for positioning and limiting the left cover plate mold (5) and the right cover plate mold (6) clamped with the H beam (7), and the limit blocks are arranged on both sides of the length direction of the H beam (7), and the limit blocks are higher than the sum of the thickness of the edge strip of the H beam (7) and the thickness of the edge strip of the left cover plate mold (5) or the right cover plate mold (6); The left cover plate mold (5) and the right cover plate mold (6) are both C-shaped structures, consisting of a central support plate and edge strips on both sides. The left and right cover plate molds are respectively clamped on both sides of the web surface of the H beam (7). The lengths of the left and right cover plate molds are set according to the length of the H beam (7). The profiles of the left and right cover plate molds match the upper and lower C-shaped inner cavities of the H beam (7). The heights of the edge strips on both sides of the left and right cover plate molds are greater than the height of the edge strips of the H beam (7) to ensure that the pressure surface is completely covered. The outer surfaces of the edge strips on both sides of the left and right cover plate molds are formed with part outline edge lines. The upper part of the frame-type upper mold (4) also adopts a frame structure, and the lower part is a lower template fixedly connected to the frame structure. The lower template adopts a solid plate, and the profile is consistent with the concave profile of the H beam (7). A plurality of limit blocks are provided on the lower surface of the lower template, and their positions correspond to the limit blocks on the frame-type lower mold (1), and together realize the limitation of the left and right cover plate molds and the H beam (7). In order to prevent the parts from tilting during the solidification process, the limit blocks on the lower template are higher than the limit blocks on the frame-type lower mold (1); positioning blocks are provided at both ends of the bottom surface of the lower template, and positioning pins are set on the bottom surfaces of the positioning blocks. The positioning pins are inserted into the circular holes on the top of the positioning support blocks at both ends of the frame-type lower mold (1) for rapid positioning and loading and unloading of the frame-type upper mold (4) and the frame-type lower mold (1), and the two are clearance-matched.

2. A carbon fiber H-beam forming tool according to claim 1, characterized in that: The limit stop on the upper template of the frame-type lower mold (1) close to the wide end of the H beam (7) is set at the 20mm margin line of the part, and the limit stop close to the narrow end of the H beam (7) is set 1mm outwardly along the 20mm margin line of the part.

3. The carbon fiber H-beam forming tool according to claim 1, characterized in that: The left cover plate mold (5) and the right cover plate mold (6) are made of carbon fiber material consistent with the H beam (7).

4. The carbon fiber H-beam forming tool according to claim 1, characterized in that: After the left cover plate mold (5) and the right cover plate mold (6) are clamped and installed with the H beam (7), the outer end faces of the edge strips on both sides thereof do not exceed the 20mm margin line of the part.

5. The carbon fiber H-beam forming tool according to claim 1, characterized in that: The upper template of the frame-type lower mold (1) and the lower template of the frame-type upper mold (4) are both made of invar steel, ensuring that the expansion coefficient during the molding process is consistent with the H beam (7).

6. A carbon fiber H-beam forming process, implemented based on the forming tooling according to any one of claims 1 to 5, the process comprising the following steps: Step 1: Use an upper web laying mold and a lower web laying mold to lay up the upper and lower C-shaped webs of the parts respectively, forming C-shaped web a (8) and C-shaped web b (9). When laying, ear pieces and holes are reserved at the wide ends of the webs for flipping and positioning; Step 2: Lift and flip the upper web paving mold, combine the upper and lower web paving molds, and knock the upper web paving mold to eliminate the combined gap. At this time, the C-shaped web a (8) and the C-shaped web b (9) are butt-jointed; Step 3: Roll the 0° fiber into two cylindrical prepreg rods 12 on the left and right, fill them into the triangular area formed by the butt joint of the C-shaped web a (8) and the C-shaped web b (9), and compact them. After heating and ironing, vacuum compact them. The iron temperature is not higher than 93°C. Step 4, using the upper and lower web layup dies to co-position and lay up the side edge strips a (10) and b (11), and starting from the wide end to obtain a part blank; Step 5, separate the part blank from the upper and lower web stacking molds, assemble the part blank with the left and right cover plate molds into one piece, trim the blank according to the edge lines of the left and right cover plate mold parts, transfer the part blank and the left and right cover plate molds together to the frame-type lower mold (1), connect the ear hole reserved at the wide end of the part blank with the transverse positioning hole on the wide end positioning support block (2), and limit it by the limit block, and align the narrow end face of the web of the part blank with the triangular tip end face of the narrow end positioning support block (3); after the part blank is positioned, position and cover the frame-type upper mold (4), and limit the left and right cover plate molds clamped with the part blank within the limit block on the frame-type upper mold (4); Step 6: After the part blank is clamped, it is solidified and formed to obtain the final H-beam (7).

Images