Carbon fiber composite material U-shaped frame, U-shaped frame forming mold and forming method

Abstract

A carbon fiber composite U-shaped frame, a U-shaped frame forming mold and a forming method, which relate to the technical field of carbon fiber composite material forming. The present invention solves the problem that the existing U-shaped frame used to match aircraft is made of metal materials and cannot meet the high performance and lightweight requirements of aerospace in my country's aircraft upgrading and replacement projects. The U-shaped frame body of the present invention is a U-shaped structure, and the U-shaped frame body is made of carbon fiber composite materials. The U-shaped frame body includes a horizontal section, a transition section and two vertical sections. The horizontal section is horizontally arranged, and the two vertical sections are vertically symmetrically arranged on the left and right sides of the upper end surface of the horizontal section. The transition section is located above the horizontal section between the two vertical sections; the flange of the horizontal section is horizontally arranged, and the inner hole of the flange is installed with a third metal part, the first metal part is installed in the first circular through hole of the left vertical section, and the second metal part is installed in the second circular through hole of the right vertical section. The present invention is used for the forming of a carbon fiber composite U-shaped frame.

Description

Technical Field

[0001] The invention relates to the technical field of carbon fiber composite material molding, and in particular to a carbon fiber composite material U-shaped frame, a U-shaped frame molding die and a molding method. Background Art

[0002] Composite materials are the material basis of high-performance products and an important guarantee for the realization of advanced design concepts and technologies. Due to their lightweight and high-strength structural advantages, high-performance composite materials have been successfully used in many national key areas. Previously, there was no precedent in China for the use of composite materials to form the main body of an aircraft U-frame. The high-performance and lightweight requirements of aerospace are an important project for the upgrading of my country's aircraft. It has many innovative difficulties, a large technical span, and a high degree of complexity. It represents the highest level of aircraft manufacturing in my country. The existing U-frames used to match aircraft are made of metal materials and cannot meet the high-performance and lightweight requirements of aerospace in my country's aircraft upgrading projects. In addition, due to the complex shape of the U-frame, the design of the layup needs to take into account the need to ensure both fiber continuity during the laying process and a reasonable and easy-to-implement layup angle benchmark. This results in great difficulty in the molding process of the composite U-frame.

[0003] In summary, the existing U-shaped frames used to match aircraft are made of metal materials, which cannot meet the high performance and lightweight requirements of aerospace in my country's aircraft upgrading projects. Summary of the invention

[0004] The purpose of the present invention is to solve the problem that the existing U-shaped frame used for matching with aircraft is made of metal materials and cannot meet the high performance and lightweight requirements of aerospace in my country's aircraft upgrading and replacement projects, and further provide a carbon fiber composite material U-shaped frame, a U-shaped frame forming mold and a forming method.

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

[0006] A carbon fiber composite U-shaped frame, the carbon fiber composite U-shaped frame comprising a U-shaped frame body 1, a first metal piece 2, a second metal piece 3, a third metal piece 4, a fourth metal piece 5 and a fifth metal piece 6, the U-shaped frame body 1 is a U-shaped structure, the U-shaped frame body 1 is made of carbon fiber composite materials, the U-shaped frame body 1 comprises a horizontal section 11, a transition section 12 and two vertical sections 13, the horizontal section 11 is horizontally arranged, the two vertical sections 13 are vertically symmetrically arranged on the left and right sides of the upper end surface of the horizontal section 11, the transition section 12 is located above the horizontal section 11 between the two vertical sections 13; the horizontal section 11 comprises a flange 111 and a plurality of connecting pieces, the flange 111 is horizontally arranged, the third metal piece 4 is arranged through a plurality of connecting pieces It is mounted on the flange 111, and the inner hole of the flange 111 is coaxially arranged with the third metal member 4; each vertical section 13 includes a first inner straight panel 131 and a first outer arc panel 132, the first inner straight panel 131 is vertically arranged on the upper end surface of the flange 111, the first outer arc panel 132 is arranged on the outer side of the first inner straight panel 131, the two ends of the first outer arc panel 132 are respectively connected to the two ends of the first inner straight panel 131, and the two ends of the third outer arc panel 124 are respectively fixed to the ends of the first outer arc panel 132 on both sides; the first inner straight panel 131 in the vertical section 13 on the left is provided with a first circular through hole 1311 and a third circular through hole 1313 in sequence from top to bottom, and the first metal member 2 and the fifth metal member 6 are respectively coaxially arranged. The shaft is installed on the first circular through hole 1311 and the third circular through hole 1313; the first inner straight panel 131 in the vertical section 13 on the right side is provided with a second circular through hole 1312 and a fourth circular through hole 1314 from top to bottom, and the second metal member 3 and the fourth metal member 5 are coaxially installed on the second circular through hole 1312 and the fourth circular through hole 1314 respectively; the transition section 12 includes a second inner straight panel 121, a second outer arc panel 122, a third inner straight panel 123, a third outer arc panel 124 and a top panel 125; the second inner straight panel 121 and the second outer arc panel 122 are sequentially arranged on the front side of the upper end face of the flange 111 from the inside to the outside, and the two ends of the second inner straight panel 121 are respectively connected to the first inner straight panel 121 on both sides The straight panel 131 is vertically fixed, and the two ends of the second outer arc panel 122 are respectively fixed to the ends of the first outer arc panel 132 on both sides; the third inner straight panel 123 and the third outer arc panel 124 are sequentially arranged on the rear side of the upper end surface of the flange 111 from the inside to the outside, and the two ends of the third inner straight panel 123 are respectively vertically fixed to the first inner straight panels 131 on both sides, and the two ends of the third outer arc panel 124 are respectively fixed to the ends of the first outer arc panels 132 on both sides; the middle part of the upper end surface of the top plate 125 is an inner concave arc surface, and the left and right ends of the top plate 125 are respectively connected to the first inner straight panels 131 on both sides, the front end of the top plate 125 is connected to the upper end of the second outer arc panel 122, and the rear end of the top plate 125 is connected to the upper end of the third outer arc panel 124.

[0007] A forming mold for processing a carbon fiber composite material U-shaped frame, the carbon fiber composite material U-shaped frame forming mold comprising a central mold X-1, a first outer mold X-2, a second outer mold X-3, a base mold X-4, an external pressure frame X-5 and two petal molds X-6; a rectangular parallelepiped shaping block is provided on the upper part of the central mold X-1, and a concave arc surface matching the lower end face of the top plate 125 of the U-shaped frame body 1 is provided on the top of the rectangular parallelepiped shaping block; the width of the rectangular parallelepiped shaping block is equal to the distance between the inner end faces of the two first inner straight panels 131 of the U-shaped frame body 1; the length ... The inner diameter of the second inner straight panel 121 and the inner end surface of the third inner straight panel 123 of the U-shaped frame body 1 are equal to each other; the middle part of the central mold X-1 is a cylindrical shaping block, and the outer diameter of the cylindrical shaping block is equal to the inner diameter of the third circular through hole 1313 of the U-shaped frame body 1; the lower part of the central mold X-1 is a disc-shaped shaping block, and the upper end surface of the disc-shaped shaping block is provided with a plurality of shaping grooves matching the second reinforcing rib 112 of the U-shaped frame body 1 in the form of a circular array; the first outer mold X-2 is a circular tubular structure, and the inner diameter of the first outer mold X-2 is equal to the inner diameter of the second outer arc panel 121 of the U-shaped frame body 1 2. The outer diameters of the cylindrical shell-like structure formed by the third outer arc panel 124 and the two first outer arc panels 132 are equal; the second outer mold X-3 is a T-shaped structure, the upper part of the second outer mold X-3 is provided with a rectangular cover plate, the lower part of the second outer mold X-3 is provided with a rectangular parallelepiped shaping block, and the bottom of the rectangular parallelepiped shaping block is provided with an inner concave arc surface matching the upper end surface of the top plate 125 of the U-shaped frame body 1; the shape of the split mold X-6 is the same as the shape of a circular arc shell Y formed between the first inner straight panel 131 of the U-shaped frame body 1, the first outer arc panel 132 and the flange 111, and the two split molds X-6 are opposite to each other. It is arranged on both sides of the central mold X-1 and forms a U-shaped structure. The central mold X-1 and the two petal molds X-6 are placed in the circular holes of the first outer mold X-2. The second outer mold X-3 is inserted into the upper part of the central mold X-1 between the two petal molds X-6. The external pressure frame X-5 is a square tubular structure, and the external pressure frame X-5 is sleeved on the outside of the first outer mold X-2. The base mold X-4 is a rectangular plate structure, and the base mold X-4 is arranged under the external pressure frame X-5. After assembly, a rectangular structure is formed between the second outer mold X-3, the base mold X-4 and the external pressure frame X-5.

[0008] A method for forming a carbon fiber composite material U-shaped frame by using a carbon fiber composite material U-shaped frame forming mold, the method is achieved by the following steps:

[0009] Step 1: Raw materials re-inspection:

[0010] The performance indicators of carbon fiber raw materials are re-inspected according to the raw material re-inspection standards before entering the factory, and they can only be used after passing the inspection;

[0011] Step 2: Prepreg manufacturing:

[0012] The carbon fiber raw material is made into a prepreg with a width of 300 mm;

[0013] Step 3: Forming of the first reinforcing rib 133:

[0014] Lay prepreg between the mold halves in each split mold X-6, i.e., the first reinforcing rib 133 after molding;

[0015] Step 4: Arrange the reinforcement ribs:

[0016] Trimming excess prepreg on the first reinforcing rib 133;

[0017] Step 5: Skinning

[0018] After installing the split mold X-6 and the center mold X-1 together, assemble the two split molds X-6 and fill the fillet with prepreg to complete the skin placement;

[0019] Step 6: Pre-pressing:

[0020] After the skin is laid, the first outer mold X-2, the second outer mold X-3, the base mold X-4 and the external pressure frame X-5 are assembled, and then the U-frame body 1 is pressurized;

[0021] Step 7: Cold mold closing:

[0022] After the pre-pressing is completed, the first outer mold X-2, the second outer mold X-3, the base mold X-4 and the external pressure frame X-5 are disassembled, and the missing parts of the U-shaped frame body 1 are leveled. After leveling, the first outer mold X-2, the second outer mold X-3, the base mold X-4 and the external pressure frame X-5 are assembled;

[0023] Step 8: Heat mold closing:

[0024] The forming mold is placed in a curing furnace for heating, and after being heated to a certain temperature, the forming mold is taken out of the curing furnace, and the U-shaped frame body 1 is pressurized;

[0025] Step 9: Curing:

[0026] After heat-sealing the mold, the mold is placed in a curing oven for curing;

[0027] Step 10: Demolding:

[0028] After the U-shaped frame body 1 is solidified and the molding mold is cooled naturally, the molding mold is removed from the U-shaped frame body 1;

[0029] Step 11: U-shaped frame body 1 trimming:

[0030] The burrs of the U-shaped frame body 1 are trimmed off;

[0031] Step 12: Draw lines:

[0032] Mark the first circular through hole 1311 and the third circular through hole 1313 to be processed on the left side first inner straight plate 131 of the U-shaped frame body 1, and mark the second circular through hole 1312 and the fourth circular through hole 1314 to be processed on the right side first inner straight plate 131 of the U-shaped frame body 1 for later cutting;

[0033] Step 13: Inspection:

[0034] After marking the U-shaped frame body 1, the lines on the U-shaped frame body 1 are inspected;

[0035] Step 14: Cutting:

[0036] The U-shaped frame body 1 is cut according to the marked lines, and a first circular through hole 1311 and a third circular through hole 1313 are cut on the first inner straight plate 131 on the left side of the U-shaped frame body 1, and a second circular through hole 1312 and a fourth circular through hole 1314 are cut on the first inner straight plate 131 on the right side of the U-shaped frame body 1;

[0037] Step 15: Assembling the shell and metal parts:

[0038] Before assembly, metal parts are first re-inspected for size upon arrival at the factory;

[0039] Then, the first metal member 2, the second metal member 3, the fourth metal member 5 and the fifth metal member 6 are respectively assembled to the first circular through hole 1311, the second circular through hole 1312, the fourth circular through hole 1314 and the third circular through hole 1313 of the U-shaped frame body 1;

[0040] Step 16: Glue and screw the U-shaped frame body 1:

[0041] The U-shaped frame body 1 is connected to the metal parts by adhesive bonding and screw connection;

[0042] Step 17: General Inspection:

[0043] After the assembly is completed, the assembled U-shaped frame body 1 is inspected for overall dimensions after assembly;

[0044] Step 18: Review:

[0045] After the customer's review, the U-shaped frame body 1 can be shipped only after it is qualified;

[0046] Step 19: Delivery:

[0047] Put the U-shaped frame body 1, certificate of conformity, etc. into the packaging box.

[0048] Compared with the prior art, the present invention has the following effects:

[0049] 1. The carbon fiber composite U-shaped frame of the present invention is a composite bracket product, which is an external reinforcement and sandwich PMI foam structure. The metal parts have high precision requirements, and the flatness and coaxiality must be less than 0.1mm. It has the advantages of high structural efficiency and good reliability, fully meets the high performance and lightweight requirements of aerospace, and promotes the application of carbon fiber composite brackets in aerospace.

[0050] 2. The molding method of the carbon fiber composite material of the present invention can realize the molding integration of the carbon fiber composite material U-shaped frame through the molding mold of the carbon fiber composite material, ensuring the structural dimensional accuracy of the precision composite material. The molding process adopts the hot melt prepreg laying and metal mold pressing molding method. The laying process ensures the continuity of the fiber and the reasonable and easy implementation of the laying angle benchmark during molding. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0052] In the attached picture:

[0053] Figure 1 is an axonometric view of the carbon fiber composite material U-shaped frame of the present invention;

[0054] Figure 2 is a front view of the carbon fiber composite material U-shaped frame of the present invention;

[0055] Figure 3 yes Figure 1 Sectional view at AA;

[0056] Figure 4 is a top view of the carbon fiber composite material U-shaped frame of the present invention;

[0057] Figure 5 yes Figure 4 Cross-sectional view at BB;

[0058] Figure 6 yes Figure 2 In the C direction view;

[0059] Figure 7 It is a structural schematic diagram of a carbon fiber composite material U-shaped frame main structure forming mold of the present invention;

[0060] Figure 8 It is an exploded view of the carbon fiber composite material U-shaped frame main structure forming mold of the present invention;

[0061] Fig. 9 The present invention is a process flow chart of the carbon fiber composite material U-shaped frame. DETAILED DESCRIPTION

[0062] Specific implementation method 1: Combination Figures 1 to 6 The present embodiment is described. The present embodiment is a carbon fiber composite material U-shaped frame. The carbon fiber composite material U-shaped frame comprises a U-shaped frame body 1, a first metal member 2, a second metal member 3, a third metal member 4, a fourth metal member 5 and a fifth metal member 6.

[0063] The U-shaped frame body 1 is a U-shaped structure. The U-shaped frame body 1 is made of carbon fiber composite material. The U-shaped frame body 1 includes a horizontal section 11, a transition section 12 and two vertical sections 13.

[0064] The horizontal section 11 is arranged horizontally, and the two vertical sections 13 are arranged vertically and symmetrically on the left and right sides of the upper end surface of the horizontal section 11. The transition section 12 is located above the horizontal section 11 between the two vertical sections 13. The horizontal section 11 includes a flange 111 and a plurality of connecting pieces. The flange 111 is arranged horizontally, and the third metal member 4 is installed on the flange 111 through the plurality of connecting pieces, and the inner hole of the flange 111 is arranged coaxially with the third metal member 4.

[0065] Each vertical section 13 includes a first inner straight panel 131 and a first outer curved panel 132. The first inner straight panel 131 is vertically arranged on the upper end surface of the flange 111. The first outer curved panel 132 is arranged outside the first inner straight panel 131. The two ends of the first outer curved panel 132 are respectively connected to the two ends of the first inner straight panel 131. The two ends of the third outer curved panel 124 are respectively fixed to the ends of the first outer curved panel 132 on both sides.

[0066] The first inner straight plate 131 in the left vertical section 13 has a first circular through hole 1311 and a third circular through hole 1313 in sequence from top to bottom, and the first metal member 2 and the fifth metal member 6 are coaxially mounted on the first circular through hole 1311 and the third circular through hole 1313 respectively;

[0067] The first inner straight plate 131 in the vertical section 13 on the right side has a second circular through hole 1312 and a fourth circular through hole 1314 formed in sequence from top to bottom, and the second metal member 3 and the fourth metal member 5 are coaxially mounted on the second circular through hole 1312 and the fourth circular through hole 1314, respectively;

[0068] The transition section 12 includes a second inner straight panel 121, a second outer curved panel 122, a third inner straight panel 123, a third outer curved panel 124 and a top panel 125;

[0069] The second inner straight panel 121 and the second outer curved panel 122 are sequentially arranged on the front side of the upper end face of the flange 111 from the inside to the outside, and the two ends of the second inner straight panel 121 are respectively vertically fixed to the first inner straight panels 131 on both sides, and the two ends of the second outer curved panel 122 are respectively fixed to the ends of the first outer curved panels 132 on both sides;

[0070] The third inner straight panel 123 and the third outer curved panel 124 are sequentially arranged on the rear side of the upper end surface of the flange 111 from the inside to the outside, and the two ends of the third inner straight panel 123 are respectively fixedly connected to the first inner straight panels 131 on both sides, and the two ends of the third outer curved panel 124 are respectively fixedly connected to the ends of the first outer curved panels 132 on both sides;

[0071] The middle part of the upper end surface of the top plate 125 is an inwardly concave arc surface, the left and right ends of the top plate 125 are respectively connected to the first inner straight panels 131 on both sides, the front end of the top plate 125 is connected to the upper end of the second outer arc panel 122, and the rear end of the top plate 125 is connected to the upper end of the third outer arc panel 124.

[0072] Specific implementation method 2: Combination Figures 1 to 6 To explain this embodiment, each vertical section 13 of this embodiment further includes three first reinforcing ribs 133, and a circular arc shell Y is formed between the first inner straight panel 131, the first outer arc panel 132 and the flange 111. Three first reinforcing ribs 133 are horizontally arranged in the circular arc shell Y from top to bottom, and the two ends of the first reinforcing rib 133 are respectively fixed to the first inner straight panel 131 and the first outer arc panel 132;

[0073] The first circular through hole 1311 is arranged between the first layer of first reinforcing ribs 133 and the second layer of first reinforcing ribs 133 in the vertical section 13 on the left, and the second circular through hole 1312 is arranged between the first layer of first reinforcing ribs 133 and the second layer of first reinforcing ribs 133 in the vertical section 13 on the right, and the first circular through hole 1311 and the second circular through hole 1312 are arranged coaxially;

[0074] The third circular through hole 1313 is arranged between the third layer of first reinforcing ribs 133 and the flange 111 in the vertical section 13 on the left, and the fourth circular through hole 1314 is arranged between the third layer of first reinforcing ribs 133 and the flange 111 in the vertical section 13 on the right. The third circular through hole 1313 and the fourth circular through hole 1314 are coaxially arranged.

[0075] In this way, the U-shaped frame body 1 is an externally reinforced, sandwich PMI foam structure, and three first reinforcing ribs 133 are horizontally arranged in the arc-shaped shell Y, which has the advantages of high structural efficiency and good reliability, and can meet the high performance and lightweight requirements of aerospace. At the same time, the first reinforcing ribs 133 are staggered with the first circular through hole 1311, the second circular through hole 1312, the third circular through hole 1313 and the fourth circular through hole 1314 to avoid interference when installing the external stepped shaft. Other components and connection relationships are the same as those in the first specific embodiment.

[0076] Specific implementation method three: Combination Figure 3To illustrate this embodiment, the first circular through hole 1311, the second circular through hole 1312, the inner hole of the flange 111, the fourth circular through hole 1314 and the third circular through hole 1313 of this embodiment are all stepped holes;

[0077] The first metal component 2, the second metal component 3, the third metal component 4, the fourth metal component 5 and the fifth metal component 6 are all circular ring structures;

[0078] The first circular through hole 1311, the second circular through hole 1312, the inner hole of the flange 111, the fourth circular through hole 1314 and the third circular through hole 1313 are all stepped holes, and the outer circles thereof are respectively processed with steps matching with the first circular through hole 1311, the second circular through hole 1312, the inner hole of the flange 111, the fourth circular through hole 1314 and the third circular through hole 1313;

[0079] The flatness and coaxiality of the first metal part 2 , the second metal part 3 , the third metal part 4 , the fourth metal part 5 and the fifth metal part 6 are all less than 0.1 mm.

[0080] In this way, the first metal member 2, the second metal member 3, the third metal member 4, the fourth metal member 5 and the fifth metal member 6 are used to cooperate with the external stepped shaft to prevent the stepped shaft from moving in the inner circle of the metal member. Other components and connection relationships are the same as those of the first or second specific embodiments.

[0081] Specific implementation method four: Combination Figure 3 and Figure 5 To explain this embodiment, a cylindrical shell structure is formed between the second outer arc panel 122 , the third outer arc panel 124 and the two first outer arc panels 132 , and the outer diameter of the cylindrical shell structure is D, where D=1000 mm.

[0082] In this way, the cylindrical shell structure has better strength than the linear plate structure, which can make up for the problem of poor strength of the carbon fiber composite material bracket and effectively improve the reliability of the carbon fiber composite material bracket. Other components and connection relationships are the same as those of the first, second or third specific embodiments.

[0083] Specific implementation method five: Combination Figure 3 and Figure 5 To illustrate this embodiment, the horizontal section 11 of this embodiment further includes a plurality of second reinforcing ribs 112 , and a plurality of second reinforcing ribs 112 are disposed on the lower end surface of the flange 111 in a circular array.

[0084] In this way, a plurality of second reinforcing ribs 112 are evenly arranged at the bottom of the flange 111, which can ensure the strength of the flange 111, and has the advantages of high structural efficiency and good reliability while meeting the requirements of high performance and light weight in aerospace. Other components and connection relationships are the same as those in the first, second, third or fourth embodiments.

[0085] Specific implementation method six: Combination Figure 2 and Figure 3 To illustrate this embodiment, the height of the carbon fiber composite material U-shaped frame of this embodiment is H, H=1281.24mm; the thickness of the first reinforcing rib 133 is 8mm; the thickness of the flange 111 is 15.5mm; the thickness of the second reinforcing rib 112 is 10mm. Other components and connection relationships are the same as those of the specific embodiments one, two, three, four or five.

[0086] Specific implementation method seven: Combination Figure 7 and Figure 8 The present embodiment is described. The present embodiment is a forming mold for processing a carbon fiber composite material U-shaped frame. The carbon fiber composite material U-shaped frame forming mold comprises a central mold X-1, a first outer mold X-2, a second outer mold X-3, a base mold X-4, an external pressure frame X-5 and two petal molds X-6;

[0087] A rectangular parallelepiped shaping block is provided on the upper part of the central mold X-1, and a concave arc surface is provided on the top of the rectangular parallelepiped shaping block to match the lower end surface of the top plate 125 of the U-shaped frame body 1; the width of the rectangular parallelepiped shaping block is equal to the distance between the inner end surfaces of the two first inner straight panels 131 of the U-shaped frame body 1; the length of the rectangular parallelepiped shaping block is equal to the distance between the inner end surfaces of the second inner straight panel 121 and the third inner straight panel 123 of the U-shaped frame body 1;

[0088] The middle part of the central mold X-1 is a cylindrical shaping block, the outer diameter of which is equal to the inner diameter of the third circular through hole 1313 of the U-shaped frame body 1;

[0089] The lower part of the central mold X-1 is a disc-shaped shaping block, and the upper end surface of the disc-shaped shaping block is provided with a plurality of shaping grooves matching the second reinforcing ribs 112 of the U-shaped frame body 1 in a circular array;

[0090] The first outer mold X-2 is a circular tubular structure, and the inner diameter of the first outer mold X-2 is equal to the outer diameter of the cylindrical shell structure formed by the second outer arc panel 122, the third outer arc panel 124 and the two first outer arc panels 132 of the U-shaped frame body 1;

[0091] The second outer mold X-3 is a T-shaped structure, a rectangular cover plate is provided on the upper part of the second outer mold X-3, and a rectangular parallelepiped shaping block is provided on the lower part of the second outer mold X-3, and a concave arc surface matching the upper end surface of the top plate 125 of the U-shaped frame body 1 is provided at the bottom of the rectangular parallelepiped shaping block;

[0092] The shape of the split mold X-6 is the same as the shape of the arc-shaped shell Y formed between the first inner straight panel 131, the first outer arc panel 132 and the flange 111 of the U-shaped frame body 1.

[0093] The two split molds X-6 are symmetrically arranged on both sides of the central mold X-1 to form a U-shaped structure. The central mold X-1 and the two split molds X-6 are placed in the circular holes of the first outer mold X-2. The second outer mold X-3 is inserted into the upper part of the central mold X-1 between the two split molds X-6.

[0094] The external pressure frame X-5 is a square tubular structure, which is mounted on the outside of the first outer mold X-2. The base mold X-4 is a rectangular plate structure, which is arranged below the external pressure frame X-5. After assembly, a rectangular structure is formed between the second outer mold X-3, the base mold X-4 and the external pressure frame X-5.

[0095] The other components and connection relationships are the same as those of the specific implementation modes one, two, three, four, five or six.

[0096] Specific implementation method eight: Combination Figure 8 To illustrate the present embodiment, each split mold X-6 of the present embodiment includes a first mold flap, a second mold flap, a third mold flap and a fourth mold flap, and the first mold flap, the second mold flap, the third mold flap and the fourth mold flap are arranged in sequence from top to bottom, and the distance between the lower end surface of the first mold flap and the upper end surface of the second mold flap is equal to the thickness of the first layer of the first reinforcing rib 133 of the U-shaped frame body 1; the distance between the lower end surface of the second mold flap and the upper end surface of the third mold flap is equal to the thickness of the second layer of the first reinforcing rib 133 of the U-shaped frame body 1; the distance between the lower end surface of the third mold flap and the upper end surface of the fourth mold flap is equal to the thickness of the third layer of the first reinforcing rib 133 of the U-shaped frame body 1.

[0097] In this way, during the molding process of the first reinforcing rib 133, prepreg is laid between the mold halves in each split mold X-6 to achieve the molding of the first reinforcing rib 133. Other components and connection relationships are the same as those of the specific embodiments one, two, three, four, five, six or seven.

[0098] Specific implementation method nine: Combination Figures 1 to 9 This embodiment is described. This embodiment is a method for forming a carbon fiber composite material U-shaped frame using a carbon fiber composite material U-shaped frame forming mold. The method is achieved by the following steps:

[0099] Step 1: Raw materials re-inspection:

[0100] The performance indicators of carbon fiber raw materials are re-inspected according to the raw material re-inspection standards before entering the factory, and they can only be used after passing the inspection;

[0101] Step 2: Prepreg manufacturing:

[0102] The carbon fiber raw material is made into a prepreg with a width of 300 mm;

[0103] Step 3: Forming of the first reinforcing rib 133:

[0104] Lay prepreg between the mold halves in each split mold X-6, i.e., the first reinforcing rib 133 after molding;

[0105] Step 4: Arrange the reinforcement ribs:

[0106] Trimming excess prepreg on the first reinforcing rib 133;

[0107] Step 5: Skinning

[0108] After installing the split mold X-6 and the center mold X-1 together, assemble the two split molds X-6 and fill the fillet with prepreg to complete the skin placement;

[0109] Step 6: Pre-pressing:

[0110] After the skin is laid, the first outer mold X-2, the second outer mold X-3, the base mold X-4 and the external pressure frame X-5 are assembled, and then the U-frame body 1 is pressurized;

[0111] Step 7: Cold mold closing:

[0112] After the pre-pressing is completed, the first outer mold X-2, the second outer mold X-3, the base mold X-4 and the external pressure frame X-5 are disassembled, and the missing parts of the U-shaped frame body 1 are leveled. After leveling, the first outer mold X-2, the second outer mold X-3, the base mold X-4 and the external pressure frame X-5 are assembled;

[0113] Step 8: Heat mold closing:

[0114] The forming mold is placed in a curing furnace for heating, and after being heated to a certain temperature, the forming mold is taken out of the curing furnace, and the U-shaped frame body 1 is pressurized;

[0115] Step 9: Curing:

[0116] After heat-sealing the mold, the mold is placed in a curing oven for curing;

[0117] Step 10: Demolding:

[0118] After the U-shaped frame body 1 is solidified and the molding mold is cooled naturally, the molding mold is removed from the U-shaped frame body 1;

[0119] Step 11: U-shaped frame body 1 trimming:

[0120] The burrs of the U-shaped frame body 1 are trimmed off;

[0121] Step 12: Draw lines:

[0122] Mark the first circular through hole 1311 and the third circular through hole 1313 to be processed on the left side first inner straight plate 131 of the U-shaped frame body 1, and mark the second circular through hole 1312 and the fourth circular through hole 1314 to be processed on the right side first inner straight plate 131 of the U-shaped frame body 1 for later cutting;

[0123] Step 13: Inspection:

[0124] After marking the U-shaped frame body 1, the lines on the U-shaped frame body 1 are inspected;

[0125] Step 14: Cutting:

[0126] The U-shaped frame body 1 is cut according to the marked lines, and a first circular through hole 1311 and a third circular through hole 1313 are cut on the first inner straight plate 131 on the left side of the U-shaped frame body 1, and a second circular through hole 1312 and a fourth circular through hole 1314 are cut on the first inner straight plate 131 on the right side of the U-shaped frame body 1;

[0127] Step 15: Assembling the shell and metal parts:

[0128] Before assembly, metal parts are first re-inspected for size upon arrival at the factory;

[0129] Then, the first metal member 2, the second metal member 3, the fourth metal member 5 and the fifth metal member 6 are respectively assembled to the first circular through hole 1311, the second circular through hole 1312, the fourth circular through hole 1314 and the third circular through hole 1313 of the U-shaped frame body 1;

[0130] Step 16: Glue and screw the U-shaped frame body 1:

[0131] The U-shaped frame body 1 is connected to the metal parts by adhesive bonding and screw connection;

[0132] Step 17: General Inspection:

[0133] After the assembly is completed, the assembled U-shaped frame body 1 is inspected for overall dimensions after assembly;

[0134] Step 18: Review:

[0135] After the customer's review, the U-shaped frame body 1 can be shipped only after it is qualified;

[0136] Step 19: Delivery:

[0137] Put the U-shaped frame body 1, certificate of conformity, etc. into the packaging box.

[0138] The other components and connection relationships are the same as those of the first, second, third, fourth, fifth, sixth, seventh or eighth specific embodiments.

[0139] The skin layer of this embodiment has a thickness of 5 mm:

[0140] (0 / 90 / 45 / -45)8 / 0 / 90 /

[0141] The flange of this embodiment has a thickness of 15.5 mm:

[0142] (0 / 90 / 45 / -45)7 / (-45 / 45 / 90 / 0)7

[0143] The molding material of the U-shaped frame body 1 of the carbon fiber composite material U-shaped frame of this embodiment is M40 / 8485; the material parameters of M40 / 8485 are shown in Table 1, and the materials of the first metal part 2, the second metal part 3, the third metal part 4, the fourth metal part 5 and the fifth metal part 6 are titanium alloy materials or aluminum alloy materials, among which the titanium alloy material parameters are shown in Table 2, and the aluminum alloy material parameters are shown in Table 3.

[0144] Table 1 Composite material parameters

[0145]

[0146]

[0147] Table 2 Titanium alloy material parameters

[0148] Modulus 100GPa Poisson's ratio 0.3 density <![CDATA[4000Kg / m 3 ]]>

[0149] Table 3 Aluminum alloy material parameters

[0150] Modulus 70GPa Poisson's ratio 0.3 density <![CDATA[2700Kg / m 3 ]]>

[0151] Specific implementation method ten: Combination Figure 8 and Fig. 9 To illustrate this embodiment, before laying the skin described in step 5, it is necessary to perform petal assembly and fillet filling.

[0152] The specific steps of the petal assembly and fillet filling are as follows:

[0153] Each edge of the split mold X-6 has a certain value of rounded corners. After the split mold X-6 is assembled, there will be gaps in the two rounded corners. In order to ensure that there is no material shortage after the U-shaped frame body 1 is formed, it is necessary to fill the rounded corners after the split mold X-6 is assembled. The other components and connection relationships are the same as those of the first, second, third, fourth, fifth, sixth, seventh, eighth or ninth embodiment.

[0154] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A forming die for a carbon fiber composite U-shaped frame, characterized in that: The molding die of the carbon fiber composite material U-shaped frame comprises a central die (X-1), a first outer die (X-2), a second outer die (X-3), a base die (X-4), an external pressure frame (X-5) and two petal dies (X-6); A rectangular parallelepiped shaping block is provided on the upper part of the central mold (X-1); a concave arc surface is provided on the top of the rectangular parallelepiped shaping block to match the lower end surface of the top plate (125) of the U-shaped frame body (1); the width of the rectangular parallelepiped shaping block is equal to the distance between the inner end surfaces of the two first inner straight panels (131) of the U-shaped frame body (1); and the length of the rectangular parallelepiped shaping block is equal to the distance between the inner end surfaces of the second inner straight panel (121) and the third inner straight panel (123) of the U-shaped frame body (1); The middle part of the central mold (X-1) is a cylindrical shaping block, and the outer diameter of the cylindrical shaping block is equal to the inner diameter of the third circular through hole (1313) of the U-shaped frame body (1); The lower part of the central mold (X-1) is a disc-shaped shaping block, and the upper end surface of the disc-shaped shaping block is provided with a plurality of shaping grooves matching the second reinforcing ribs (112) of the U-shaped frame body (1) in a circular array; The first outer mold (X-2) is a circular tubular structure, and the inner diameter of the first outer mold (X-2) is equal to the outer diameter of a cylindrical shell structure formed by the second outer arc panel (122), the third outer arc panel (124) and the two first outer arc panels (132) of the U-shaped frame body (1); The second outer mold (X-3) is a T-shaped structure, a rectangular cover plate is provided on the upper part of the second outer mold (X-3), a rectangular parallelepiped shaping block is provided on the lower part of the second outer mold (X-3), and a concave arc surface matching the upper end surface of the top plate (125) of the U-shaped frame body (1) is provided on the bottom of the rectangular parallelepiped shaping block; The shape of the split mold (X-6) is the same as the shape of a circular arc shell (Y) formed between the first inner straight panel (131), the first outer arc panel (132) and the flange (111) of the U-shaped frame body (1). The two split molds (X-6) are symmetrically arranged on both sides of the central mold (X-1) to form a U-shaped structure. The central mold (X-1) and the two split molds (X-6) are placed in the circular holes of the first outer mold (X-2). The second outer mold (X-3) is inserted into the upper part of the central mold (X-1) between the two split molds (X-6). The external pressure frame (X-5) is a square tubular structure, and the external pressure frame (X-5) is sleeved outside the first outer mold (X-2). The base mold (X-4) is a rectangular plate structure, and the base mold (X-4) is arranged below the external pressure frame (X-5). After assembly, a rectangular parallelepiped structure is formed between the second outer mold (X-3), the base mold (X-4) and the external pressure frame (X-5); The carbon fiber composite material U-shaped frame comprises a U-shaped frame body (1), a first metal part (2), a second metal part (3), a third metal part (4), a fourth metal part (5) and a fifth metal part (6), The U-shaped frame body (1) is a U-shaped structure. The U-shaped frame body (1) is made of carbon fiber composite material. The U-shaped frame body (1) comprises a horizontal section (11), a transition section (12) and two vertical sections (13). The horizontal section (11) is arranged horizontally, the two vertical sections (13) are arranged vertically and symmetrically on the left and right sides of the upper end surface of the horizontal section (11), and the transition section (12) is located above the horizontal section (11) between the two vertical sections (13); the horizontal section (11) comprises a flange (111) and a plurality of connecting pieces, the flange (111) is arranged horizontally, the third metal piece (4) is mounted on the flange (111) through the plurality of connecting pieces, and the inner hole of the flange (111) is arranged coaxially with the third metal piece (4); Each vertical section (13) comprises a first inner straight panel (131) and a first outer curved panel (132), wherein the first inner straight panel (131) is vertically arranged on the upper end surface of the flange (111), and the first outer curved panel (132) is arranged outside the first inner straight panel (131), and two ends of the first outer curved panel (132) are respectively connected to two ends of the first inner straight panel (131); A first circular through hole (1311) and a third circular through hole (1313) are sequentially provided on the first inner straight panel (131) in the left vertical section (13) from top to bottom, and the first metal member (2) and the fifth metal member (6) are coaxially mounted on the first circular through hole (1311) and the third circular through hole (1313), respectively; A second circular through hole (1312) and a fourth circular through hole (1314) are sequentially provided on the first inner straight panel (131) in the vertical section (13) on the right side from top to bottom, and a second metal member (3) and a fourth metal member (5) are coaxially mounted on the second circular through hole (1312) and the fourth circular through hole (1314), respectively; The transition section (12) comprises a second inner straight panel (121), a second outer curved panel (122), a third inner straight panel (123), a third outer curved panel (124) and a top panel (125); The second inner straight panel (121) and the second outer curved panel (122) are sequentially arranged on the front side of the upper end surface of the flange (111) from the inside to the outside, the two ends of the second inner straight panel (121) are respectively vertically fixed to the first inner straight panels (131) on both sides, and the two ends of the second outer curved panel (122) are respectively fixed to the ends of the first outer curved panels (132) on both sides; The third inner straight panel (123) and the third outer curved panel (124) are sequentially arranged on the rear side of the upper end surface of the flange (111) from the inside to the outside, the two ends of the third inner straight panel (123) are respectively vertically fixed to the first inner straight panels (131) on both sides, and the two ends of the third outer curved panel (124) are respectively fixed to the ends of the first outer curved panels (132) on both sides; The middle part of the upper end surface of the top plate (125) is an inner concave arc surface, the left and right ends of the top plate (125) are respectively connected to the first inner straight panels (131) on both sides, the front end of the top plate (125) is connected to the upper end of the second outer arc panel (122), and the rear end of the top plate (125) is connected to the upper end of the third outer arc panel (124).

2. The forming die of a carbon fiber composite material U-shaped frame according to claim 1, characterized in that: Each vertical section (13) further comprises three first reinforcing ribs (133); a circular arc shell (Y) is formed between the first inner straight panel (131), the first outer arc panel (132) and the flange (111); three first reinforcing ribs (133) are horizontally arranged in sequence from top to bottom in the circular arc shell (Y); two ends of the first reinforcing ribs (133) are respectively fixedly connected to the first inner straight panel (131) and the first outer arc panel (132); The first circular through hole (1311) is arranged between the first layer of first reinforcing ribs (133) and the second layer of first reinforcing ribs (133) in the vertical section (13) on the left, and the second circular through hole (1312) is arranged between the first layer of first reinforcing ribs (133) and the second layer of first reinforcing ribs (133) in the vertical section (13) on the right, and the first circular through hole (1311) and the second circular through hole (1312) are arranged coaxially; The third circular through hole (1313) is arranged between the third layer of the first reinforcing rib (133) and the flange (111) in the vertical section (13) on the left, and the fourth circular through hole (1314) is arranged between the third layer of the first reinforcing rib (133) and the flange (111) in the vertical section (13) on the right, and the third circular through hole (1313) and the fourth circular through hole (1314) are coaxially arranged.

3. The forming die of a carbon fiber composite material U-shaped frame according to claim 2, characterized in that: The first circular through hole (1311), the second circular through hole (1312), the inner hole of the flange (111), the fourth circular through hole (1314) and the third circular through hole (1313) are all stepped holes; The first metal part (2), the second metal part (3), the third metal part (4), the fourth metal part (5) and the fifth metal part (6) are all circular ring structures; The first circular through hole (1311), the second circular through hole (1312), the inner hole of the flange (111), the fourth circular through hole (1314) and the third circular through hole (1313) are all stepped holes, and the outer circles thereof are respectively processed with steps matching the first circular through hole (1311), the second circular through hole (1312), the inner hole of the flange (111), the fourth circular through hole (1314) and the third circular through hole (1313); The flatness and coaxiality of the first metal part (2), the second metal part (3), the third metal part (4), the fourth metal part (5) and the fifth metal part (6) are all less than 0.1 mm.

4. The forming die of a carbon fiber composite material U-shaped frame according to claim 3, characterized in that: A cylindrical shell-like structure is formed between the second outer arc panel (122), the third outer arc panel (124) and the two first outer arc panels (132), and the outer diameter of the cylindrical shell-like structure is D, where D=1000 mm.

5. The forming die of a carbon fiber composite material U-shaped frame according to claim 4, characterized in that: The horizontal section (11) further comprises a plurality of second reinforcing ribs (112), and the lower end surface of the flange (111) is provided with the plurality of second reinforcing ribs (112) in a circular array.

6. The forming die of a carbon fiber composite material U-shaped frame according to claim 5, characterized in that: The height of the carbon fiber composite material U-shaped frame is H, H=1281.24 mm; the thickness of the first reinforcing rib (133) is 8 mm; the thickness of the flange (111) is 15.5 mm; and the thickness of the second reinforcing rib (112) is 10 mm.

7. The forming die of a carbon fiber composite material U-shaped frame according to claim 1, characterized in that: Each split mold (X-6) comprises a first mold flap, a second mold flap, a third mold flap and a fourth mold flap, and the first mold flap, the second mold flap, the third mold flap and the fourth mold flap are arranged in sequence from top to bottom, and the distance between the lower end surface of the first mold flap and the upper end surface of the second mold flap is equal to the thickness of the first layer of the first reinforcing rib (133) of the U-shaped frame body (1); the distance between the lower end surface of the second mold flap and the upper end surface of the third mold flap is equal to the thickness of the second layer of the first reinforcing rib (133) of the U-shaped frame body (1); the distance between the lower end surface of the third mold flap and the upper end surface of the fourth mold flap is equal to the thickness of the third layer of the first reinforcing rib (133) of the U-shaped frame body (1).

8. A method for forming a carbon fiber composite material U-shaped frame using the forming mold of the carbon fiber composite material U-shaped frame according to claim 1 or 7, characterized in that: The method is implemented by the following steps: Step 1: Raw materials re-inspection: The performance indicators of carbon fiber raw materials are re-inspected according to the raw material re-inspection standards before entering the factory, and they can only be used after passing the inspection; Step 2: Prepreg manufacturing: The carbon fiber raw material is made into a prepreg with a width of 300 mm; Step 3: Forming the first reinforcing rib (133): Laying prepreg between the mold halves in each split mold (X-6), i.e. the first reinforcing rib (133) after molding; Step 4: Arrange the reinforcement ribs: trimming excess prepreg on the first reinforcing rib (133); Step 5: Skinning After the split mold (X-6) and the center mold (X-1) are installed together, the fillet parts of the two split molds (X-6) are assembled and filled with prepreg to complete the laying of the skin; Step 6: Pre-pressing: After the skin is laid, the first outer mold (X-2), the second outer mold (X-3), the base mold (X-4) and the external pressure frame (X-5) are assembled, and then the U-shaped frame body (1) is pressurized; Step 7: Cold mold closing: After the pre-pressing is completed, the first outer mold (X-2), the second outer mold (X-3), the base mold (X-4) and the external pressure frame (X-5) are disassembled, and the places where there are missing materials on the U-shaped frame body (1) are leveled. After the leveling, the first outer mold (X-2), the second outer mold (X-3), the base mold (X-4) and the external pressure frame (X-5) are assembled; Step 8: Heat mold closing: The forming mold is placed in a curing furnace for heating, and after being heated to a certain temperature, the forming mold is taken out of the curing furnace, and the U-shaped frame body (1) is pressurized; Step 9: Curing: After heat-sealing the mold, the mold is placed in a curing oven for curing; Step 10: Demolding: After the U-shaped frame body (1) is solidified, the molding mold is removed from the U-shaped frame body (1) after the molding mold is naturally cooled; Step 11: U-shaped frame body (1) trimming: The burrs on the U-shaped frame body (1) are trimmed off; Step 12: Draw lines: Marking the first circular through hole (1311) and the third circular through hole (1313) to be processed on the first inner straight panel (131) on the left side of the U-shaped frame body (1), and marking the second circular through hole (1312) and the fourth circular through hole (1314) to be processed on the first inner straight panel (131) on the right side of the U-shaped frame body (1) for later cutting; Step 13: Inspection: After marking the U-shaped frame body (1), inspecting the lines on the U-shaped frame body (1); Step 14: Cutting: The U-shaped frame body (1) is cut according to the marked lines, a first circular through hole (1311) and a third circular through hole (1313) are cut on the first inner straight panel (131) on the left side of the U-shaped frame body (1), and a second circular through hole (1312) and a fourth circular through hole (1314) are cut on the first inner straight panel (131) on the right side of the U-shaped frame body (1); Step 15: Assembling the shell and metal parts: Before assembly, metal parts are first re-inspected for size upon arrival at the factory; Then, the first metal piece (2), the second metal piece (3), the fourth metal piece (5) and the fifth metal piece (6) are respectively assembled to the first circular through hole (1311), the second circular through hole (1312), the fourth circular through hole (1314) and the third circular through hole (1313) of the U-shaped frame body (1); Step 16: Glue and screw the U-shaped frame body (1): The U-shaped frame body (1) is connected to the metal part by adhesive bonding and screw connection; Step 17: General Inspection: After the assembly is completed, the assembled U-shaped frame body (1) is inspected for overall dimensions after assembly; Step 18: Review: After the customer's review, the U-shaped frame body (1) can be shipped only after it is qualified; Step 19: Factory delivery: Put the U-shaped frame body (1) and the certificate of conformity into the packaging box.

9. The method for forming a carbon fiber composite material U-shaped frame using a forming mold of a carbon fiber composite material U-shaped frame according to claim 8, characterized in that: Before laying the skin as described in step 5, it is necessary to assemble the petals and fillet the corners. The specific steps of the petal assembly and fillet filling are as follows: The edges on each split mold (X-6) have a certain amount of rounded corners. After the split molds (X-6) are assembled, gaps will appear in the two rounded corners. In order to ensure that there is no material shortage after the U-shaped frame body (1) is formed, it is necessary to fill the rounded corners after the split molds (X-6) are assembled.

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