Composite material perforated frame and forming die and manufacturing method thereof

Abstract

The invention provides a composite material perforated frame and a forming mold and a manufacturing method thereof, and belongs to the field of composite material forming. The problem that a structure with inconsistent thickness and an internal reinforcement structure are difficult to synchronously form is solved. The composite material trepanning frame comprises a composite material trepanning frame body and a forming die, the trepanning frame body is of an integrally-formed structure and comprises side plates, a top plate and a reinforcing plate, the top plate is octagonal, a first opening is formed in the center of the top plate, four second openings are evenly distributed in the top plate, and the side plates are arranged on the periphery of the top plate; the reinforcing plates are of a cross shape, the centers of the reinforcing plates are of a square structure, the reinforcing plates are arranged in the centers of the top plate in the vertical direction and the horizontal direction correspondingly and connected with the side plates, and the forming die is used for machining the composite material trepanning frame. The composite material perforated frame is mainly machined through a forming die by adopting an integral forming technology.

Description

Technical Field

[0001] The invention belongs to the technical field of composite material forming, and in particular relates to a composite material perforated frame, a forming die and a manufacturing method thereof. Background Art

[0002] With the rapid development of high-end manufacturing fields such as aerospace and new energy vehicles, lightweight and structural function integration have become the core demands of structural design. As a key sealing component of the storage and transportation system, the mechanical properties, environmental tolerance and service life of the frame structure of the tank cover directly affect the safety and reliability of the entire system.

[0003] The opening frames on traditional tank covers are mostly made of metal materials such as aluminum alloy and titanium alloy. Although they have good processability and fatigue resistance, they still have obvious limitations: first, the high density of metal materials leads to insufficient structural strength, and faces a weight reduction bottleneck under high load conditions; second, stress corrosion or plastic deformation is prone to occur in extreme environments such as acid and alkali corrosion, damp heat or low temperature; third, the local stress concentration problem of welding or bolted connections is prominent, and the long-term sealing maintenance cost is high.

[0004] Composite materials have gradually become an ideal choice to replace traditional metal materials due to their advantages such as high strength, high modulus and low density. However, existing composite frame structures still face the following challenges in the design and manufacturing process:

[0005] Difficulty in molding when thickness is inconsistent: In order to meet the force requirements of different areas, the frame thickness needs to be designed to be inconsistent. Traditional manufacturing methods are difficult to achieve integrated molding of structures with inconsistent thickness, and usually require segmented manufacturing and then connection, which increases manufacturing costs and assembly difficulty.

[0006] The internal reinforcement structure is complex: In order to improve the rigidity, the frame needs to be designed with reinforcement and reinforcement structures. However, in the prior art, these structures usually need to be prefabricated separately and then assembled with the main structure, which makes it difficult to achieve synchronous molding, resulting in uneven rigidity and strength of the overall structure.

[0007] Challenges of integrated molding: For products with complex structures and thickness variations, traditional molding methods are difficult to achieve efficient and high-quality integrated manufacturing, and molding is difficult. Summary of the invention

[0008] In view of this, the present invention aims to propose a composite material open hole frame and its forming mold and manufacturing method, so as to solve the problem that the composite material frame is difficult to be formed in an integrated manner when it has large openings and inconsistent thickness, and the internal reinforcement structure is complex.

[0009] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a composite material open hole frame, the open hole frame adopts carbon fiber composite material, is an integrated molding structure, and the outer contour is an octagonal structure, which includes side panels, a top panel and a reinforcing panel. The top panel is octagonal, and a first opening is arranged at the center position. Four second openings are evenly distributed on the top panel. Side panels are arranged around the top panel. The reinforcing panel is cross-shaped and has a square structure at the center. The reinforcing panels are respectively arranged at the center of the top panel in the vertical direction and the horizontal direction and are connected to the side panels.

[0010] Furthermore, the overall height H of the opening frame is 95 mm, the lowest height h is 55 mm, the first opening radius is 30 mm, and the second opening radius is 137.5 mm.

[0011] Furthermore, the thickness of the top plate is 5 mm, the thickness of the reinforcing plate is 4 mm, and the thickness of the side plate is 1.8 mm.

[0012] A forming die for a composite material perforated frame, comprising an inner flap module, an outer flap module, a gland, a positioning block and a base, wherein the gland is an octagonal structure with four through holes, the positioning block is a cube structure with a through hole in the center, a cylindrical protrusion on the top surface, and a square protrusion on the bottom surface, the positioning block and the inner flap module are both arranged on the base, the inner flap module is arranged outside the outer block, the outer flap module comprises a short trapezoidal module and a long trapezoidal module, and there are four short trapezoidal modules and four long trapezoidal modules, Short trapezoidal modules and long trapezoidal modules are alternately arranged around the inner petal module, which includes four polygonal modules. A cylindrical protrusion is arranged on the upper surface of each module, and a cylindrical through hole is arranged in the middle. The top surface of the cylindrical protrusion on the module is arranged with a threaded hole, and the side wall of the module is arranged with a stepped depression. A cross-shaped protrusion and four openings are arranged on the top surface of the base, and a notch matching the square protrusion on the bottom surface of the positioning block is arranged in the middle of the cross. A through hole is arranged in the middle of the cross-shaped protrusion, and the through hole corresponds to the through hole in the center of the positioning block.

[0013] Furthermore, threaded holes are arranged around the outer sides of the four through holes of the gland, and the positions of the threaded holes of the gland correspond to the positions of the threaded holes of the module.

[0014] Furthermore, threaded holes are arranged in a circle outside the four openings of the base, and the positions of the threaded holes correspond to those of the module.

[0015] Furthermore, the stepped recess of the module has a depth of 1.8 mm.

[0016] Furthermore, the inner diameter of the opening of the gland is 138 mm.

[0017] Furthermore, the base, the outer flap module, the inner flap module, the positioning block and the pressure cover are all made of No. 45 steel.

[0018] A method for manufacturing a composite material perforated frame comprises the following steps:

[0019] S1: Apply release agent to the surface of the inner petal module group and the positioning block, lay 2mm prepreg around the positioning block and install it in the center of the base;

[0020] S2: Apply 2mm prepreg on the upper surface, inner side and stepped concave parts of each module of the inner split module, use the prepreg to level the stepped concave parts of the outer side, and then install the inner split module on the base;

[0021] S3: Lay 1.2mm prepreg on the upper surface of the module and the positioning block, and then lay 1.8mm prepreg on the top and side surfaces of the inner petal module and the top surface of the positioning block;

[0022] S4: Install the outer flap module around the inner flap module, and then install the gland on top of the inner flap module;

[0023] S5: vacuum the entire mold bag for pre-compaction, and demould after curing.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The present invention realizes the synchronous molding of the frame body, openings, internal reinforcement and local reinforcement through an integrated molding process, solving the problem that it is difficult to realize the synchronous molding of large openings, inconsistent overall thickness of the structure and internal reinforcement in the traditional manufacturing method;

[0026] 2. The present invention reduces the overall cost by setting up corresponding forming dies. The forming dies are made of 45# steel. Compared with the traditional high-cost nickel-based alloy dies, the manufacturing cost is significantly reduced.

[0027] 3. The present invention realizes integrated molding of complex structures. By adopting the design of modular mold combination and precise assembly of positioning blocks, integrated demoulding of large openings, complex cross-sections and thickness difference structures is realized, avoiding structural disassembly damage. The modular mold combination supports rapid disassembly and assembly, shortening the production cycle of a single product. By adjusting the number of petal molds, it can adapt to different opening sizes, and the mold can be reused;

[0028] 4. The present invention improves the overall rigidity and strength of the product through an integrated molding process, and reduces the manufacturing cost and molding difficulty, and is suitable for aerospace, automobile, rail transportation and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0030] Figure 1 This is a schematic diagram of the axial structure of a composite material perforated frame according to the present invention;

[0031] Figure 2 This is a schematic diagram of the front structure of a composite material perforated frame according to the present invention;

[0032] Figure 3 This is a schematic diagram of the top structure of a composite material perforated frame according to the present invention;

[0033] Figure 4 This is a schematic diagram of the upper surface structure of a composite material perforated frame according to the present invention;

[0034] Figure 5 An exploded view of a forming die for a composite material perforated frame according to the present invention;

[0035] Figure 6 This is a schematic diagram of the axial structure of a long trapezoidal module of a forming die for a composite material perforated frame according to the present invention;

[0036] Figure 7 This is a schematic diagram of the front structure of a long trapezoidal module of a forming die for a composite material perforated frame according to the present invention;

[0037] Figure 8 It is a schematic diagram of the top structure of a long trapezoidal module of a forming die for a composite material perforated frame according to the present invention;

[0038] Fig. 9 This is a schematic diagram of the axial structure of a short trapezoidal module of a forming die for a composite material perforated frame according to the present invention;

[0039] Fig.10 This is a front structural schematic diagram of a short trapezoidal module of a forming die for a composite material perforated frame according to the present invention;

[0040] Fig.11 It is a schematic diagram of the top structure of a short trapezoidal module of a forming die for a composite material perforated frame according to the present invention;

[0041] Fig.12 This is a schematic diagram of the axial structure of a module of a forming mold for a composite material perforated frame according to the present invention;

[0042] Fig.13 This is a schematic diagram of the front structure of a module of a forming mold for a composite material perforated frame according to the present invention;

[0043] Fig.14 It is a schematic diagram of the top structure of a module of a forming mold for a composite material perforated frame according to the present invention;

[0044] Fig.15 It is a schematic diagram of the upward structure of a module of a forming mold of a composite material perforated frame according to the present invention;

[0045] Fig.16 This is a schematic diagram of the axial structure of a positioning block of a forming die for a composite material perforated frame according to the present invention;

[0046] Fig.17 It is a front structural schematic diagram of a positioning block of a forming die of a composite material perforated frame according to the present invention;

[0047] Fig.18 It is a schematic diagram of the top structure of a positioning block of a forming die for a composite material perforated frame according to the present invention;

[0048] Fig.19 It is a schematic diagram of the upward structure of a positioning block of a forming die of a composite material perforated frame according to the present invention;

[0049] Fig. 20 It is a schematic diagram of the axial structure of the base of a forming mold of a composite material perforated frame according to the present invention;

[0050] Fig.21 It is a front structural schematic diagram of a base of a forming mold of a composite material perforated frame according to the present invention;

[0051] Fig. 22 It is a schematic diagram of the top structure of the base of a forming mold of a composite material perforated frame according to the present invention;

[0052] Fig.23 It is a schematic diagram of the upward structure of the base of a forming mold of a composite material perforated frame according to the present invention;

[0053] Fig.24 It is a schematic diagram of the axial structure of a gland of a forming die of a composite material perforated frame according to the present invention;

[0054] Fig.25 It is a schematic diagram of the front structure of a gland of a forming die of a composite material perforated frame according to the present invention;

[0055] Fig.26 It is a schematic diagram of the top structure of a molding die cover of a composite material perforated frame according to the present invention;

[0056] Fig. 27The present invention is a schematic diagram of the upward structure of a pressure cover of a forming die for a composite material perforated frame according to the present invention.

[0057] In the figure:

[0058] 1. Side panel; 2. Top panel; 3. Reinforcement panel; 4. First opening; 5. Second opening; 6. Pressure cover; 7. Short trapezoidal module; 8. Long trapezoidal module; 9. Positioning block; 10. Module; 11. Base. DETAILED DESCRIPTION

[0059] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely explain the technical solutions in the embodiments of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict, and the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0060] Specific implementation method: see Figure 1-4 The present embodiment is described, a composite material open hole frame, the open hole frame is made of carbon fiber composite material, the carbon fiber composite material can significantly reduce the weight of the structure by adopting the carbon fiber composite material, and at the same time provide excellent mechanical properties, the open hole frame is an integrally formed structure, and the outer contour is an octagonal structure, the octagonal structure has good mechanical properties and stability, can effectively disperse stress, and reduce local stress concentration, it includes a side panel 1, a top panel 2 and a reinforcing panel 3, the top panel 2 is an octagon, a first opening 4 is arranged at the center, four second openings 5 ​​are evenly distributed on the top panel 2, side panels 1 are arranged around the top panel 2, the reinforcing panel 3 is cross-shaped and has a square structure at the center, the reinforcing panel 3 is respectively arranged at the center of the top panel 2 in the vertical direction and the horizontal direction and is connected to the side panel 1, the cross-shaped reinforcing panel 3 can effectively enhance the bending and torsional properties of the frame, and at the same time maintain the integrity of the structure, the second open hole frame of the composite material has a good surface condition, uniform thickness, and the external dimensions meet the design requirements.

[0061] The overall height H of the second opening frame is 95 mm, the lowest height h is 55 mm, the radius of the first opening 4 is 30 mm, and the radius of the second opening 5 is 137.5 mm.

[0062] The thickness of the top plate 2 is 5 mm, the thickness of the reinforcing plate 3 is 4 mm, and the thickness of the side plate 1 is 1.8 mm.

[0063] See also Figure 4-27The present embodiment is described as a forming mold for a composite material perforated frame, which includes an inner petal module, an outer petal module, a pressure cover 6, a positioning block 9 and a base 11. The pressure cover 6 is an octagonal structure with four through holes. The pressure cover 6 is used to cover the top of the forming mold to provide pressure distribution above during forming. The positioning block 9 is a cubic structure with a through hole in the center for corresponding to the through hole of the base 11 to achieve alignment inside the mold. A cylindrical protrusion is provided on the top surface of the positioning block 9 for aligning with the inner petal. The module cooperates, and a square protrusion is set on the bottom surface of the positioning block 9 to match the notch in the middle of the cross-shaped protrusion of the base 11. The positioning block 9 is used as a support point inside the molding mold. The positioning block 9 and the inner petal module are both arranged on the base 11, and the inner petal module is arranged outside the fixed outer block 9. The outer petal module includes a short trapezoidal module 7 and a long trapezoidal module 8. There are four short trapezoidal modules 7 and long trapezoidal modules 8. The short trapezoidal modules 7 and the long trapezoidal modules 8 are alternately arranged around the inner petal module. The cooperation of the inner flap module realizes the control of the external shape and size of the frame. The inner flap module includes four polygonal modules 10. A cylindrical protrusion is arranged on the upper surface of each module 10, and a cylindrical through hole is arranged in the middle. A threaded hole is arranged on the top surface of the cylindrical protrusion on the module 10. There are several threaded holes that vertically penetrate the module 10 and are evenly distributed along the circumferential direction. The threaded holes are used to cooperate with the threaded holes of the base 11. The side walls of the module 10 are provided with a stepped depression for forming a reinforcing plate structure in the side walls of the frame. A cross-shaped protrusion and four openings are arranged on the top surface of the base 11. A notch is arranged in the middle of the cross to match the square protrusion on the bottom surface of the positioning block 9, which is used to cooperate with the square protrusion on the bottom surface of the positioning block 9. A through hole is arranged in the middle of the cross-shaped protrusion, which corresponds to the through hole in the center of the positioning block 9. The flap design of the inner flap module and the outer flap module facilitates the assembly and demoulding of the mold, and can adapt to complex frame structures. Through the cooperation of the positioning block 9 and the base 11, the alignment accuracy inside the mold is ensured and the molding quality is improved.

[0064] The mold assembly relationship is as follows:

[0065] The positioning block 9 is installed in the center of the base 11, and the bottom protrusion of the positioning block 9 corresponds to the notch in the center of the cross-shaped protrusion of the base 11. The inner flap module is installed around the outside of the positioning block 9, and the inner flap module is fixed to the base 11 through threaded holes. The short trapezoidal modules 7 and the long trapezoidal modules 8 in the outer flap module are alternately installed around the outside of the inner flap module. The pressure cover 6 is installed on the top of the mold, fixed to the inner flap module through threaded holes, and covers the upper part of the entire mold. The above-mentioned molding mold is suitable for a variety of composite material molding processes, has high versatility and scalability, and the assembly and disassembly process of the mold is simple, easy to operate, can effectively shorten the production cycle, and significantly improve the production efficiency and product quality.

[0066] Threaded holes are arranged around the outer sides of the four through holes of the gland 6 . The threaded holes of the gland 6 correspond to the positions of the threaded holes of the module 10 . The gland 6 and the module 10 are connected via the threaded holes.

[0067] The four openings of the base 11 are provided with threaded holes in a circle outside thereof, and the threaded holes correspond to the positions of the threaded holes of the module 10 . The module 10 is connected to the base 11 through the threaded holes.

[0068] The stepped recess of the module 10 has a depth of 1.8 mm.

[0069] The inner diameter of the opening of the gland 6 is 138 mm.

[0070] The base 11, the outer flap mold, the inner flap mold, the positioning block 9 and the pressure cover 6 are all made of 45# steel.

[0071] See also Figure 1-27 The present embodiment describes a method for manufacturing a composite material perforated frame, comprising the following steps:

[0072] S1: Apply a release agent to the surface of the inner split mold and the positioning block 9 to prevent the prepreg from sticking to the mold and facilitate subsequent demoulding. Lay 2mm prepreg around the positioning block 9 to ensure that there are no bubbles and wrinkles. Then install the positioning block 9 in the center of the base 11 through the positioning device to ensure the accuracy of the position of the positioning block 9.

[0073] S2: 2mm prepreg is applied on the upper surface, inner side and stepped depression of each module 10 of the inner petal module, and the stepped depression of the outer side is leveled with the prepreg to ensure that the surface is flat and the thickness is uniform. Then, each module 10 of the inner petal module is sequentially installed on the base 11 and fixed to the base 11 through threaded holes. At this time, the thickness of the prepreg between every two modules 10 is 4mm, and the thickness of the prepreg at the stepped depression of the outer side is also 4mm.

[0074] S3: 1.2mm prepreg is laid on the upper surface of the module 10 and the positioning block 9, and then 1.8mm prepreg is laid on the top and side surfaces of the inner petal module and the top surface of the positioning block. At this time, the thickness of the prepreg on the top surface of the inner petal module is 5mm, and the thickness of the prepreg around the outer side of the inner petal module is 1.8mm;

[0075] S4: Install the outer flap module around the inner flap module to ensure that the components fit closely together, use a clamp or positioning pin to fix the outer flap module, and then install the gland 6 on top of the inner flap module to ensure that the gland 6 has good sealing performance with other molds;

[0076] S5: The whole mold is bagged and vacuumed for pre-compaction, and then sent to the autoclave for curing, that is, kept at 100°C for two hours, and then heated to 150°C and kept for another two hours. After the curing is completed, it is cooled in the autoclave. Usually, the mold temperature is reduced to no more than 30°C above room temperature. After curing, it is cooled and formed before demoulding. When demoulding, the pressure cover 6, the outer petal module, the base 11, the inner petal module and the positioning block 9 are demoulded in this order, and then the demoulded product is polished to be smooth, so as to obtain the second open hole frame of the composite material.

[0077] Since the frame has many openings, a large radius, and a large variation in overall thickness, the molding is complex and the production is difficult, the present invention designs a molding mold for a composite material frame, which can realize the one-piece molding of the composite material frame. The mold combination is simple, the operation difficulty is low, the single-piece production cycle is short, and it is easy to demold. The composite material frame processed by the above steps has a good surface condition, uniform thickness, and the external dimensions meet the design requirements.

[0078] The specific embodiments of the present invention disclosed above are only used to help explain the present invention. The specific embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. According to the content of this specification, many modifications and changes can be made. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well.

Claims

1. A composite material perforated frame, characterized in that: The perforated frame is made of carbon fiber composite material and is an integrally formed structure with an outer contour of an octagonal structure. It comprises a side panel (1), a top panel (2) and a reinforcing panel (3). The top panel (2) is octagonal and has a first opening (4) at the center. Four second openings (5) are evenly distributed on the top panel (2). The side panels (1) are arranged around the top panel (2). The reinforcing panel (3) is cross-shaped and has a square structure at the center. The reinforcing panel (3) is respectively arranged at the center of the top panel (2) in the vertical direction and the horizontal direction and is connected to the side panel (1).

2. A composite material perforated frame according to claim 1, characterized in that: The overall height H of the opening frame is 95 mm, the lowest height h is 55 mm, the radius of the first opening (4) is 30 mm, and the radius of the second opening (5) is 137.5 mm.

3. The composite material perforated frame according to claim 1, characterized in that: The thickness of the top plate (2) is 5 mm, the thickness of the reinforcing plate (3) is 4 mm, and the thickness of the side plate (1) is 1.8 mm.

4. A forming die for a composite material perforated frame as claimed in claim 1, characterized in that: It comprises an inner flap module, an outer flap module, a pressure cover (6), a positioning block (9) and a base (11). The pressure cover (6) is an octagonal structure with four through holes. The positioning block (9) is a cubic structure with a through hole at the center, a cylindrical protrusion on the top surface and a square protrusion on the bottom surface. The positioning block (9) and the inner flap module are both arranged on the base (11). The inner flap module is arranged outside the outer block (9). The outer flap module comprises a short trapezoidal module (7) and a long trapezoidal module (8). There are four short trapezoidal modules (7) and four long trapezoidal modules (8). 7) and long trapezoidal modules (8) are alternately arranged around the inner flap module, and the inner flap module includes four polygonal modules (10), each module (10) has a cylindrical protrusion on the upper surface, a cylindrical through hole in the middle, a threaded hole on the top surface of the cylindrical protrusion on the module (10), and a stepped depression on the side wall of the module (10). A cross-shaped protrusion and four openings are arranged on the top surface of the base (11), a notch matching the square protrusion on the bottom surface of the positioning block (9) is arranged in the middle of the cross, and a through hole is arranged in the middle of the cross-shaped protrusion, which corresponds to the through hole in the center of the positioning block (9).

5. A composite material perforated frame according to claim 4, characterized in that: Threaded holes are arranged around the outer sides of the four through holes of the gland (6), and the positions of the threaded holes of the gland (6) correspond to the positions of the threaded holes of the module (10).

6. A composite material perforated frame according to claim 5, characterized in that: Threaded holes are arranged in a circle outside the four openings of the base (11), and the positions of the threaded holes correspond to those of the module (10).

7. A composite material perforated frame according to claim 6, characterized in that: The stepped recess of the module (10) has a depth of 1.8 mm.

8. The composite material perforated frame according to claim 4, characterized in that: The inner diameter of the opening of the gland (6) is 138 mm.

9. The composite material perforated frame according to claim 4, characterized in that: The base (11), the outer flap mold, the inner flap mold, the positioning block (9) and the pressure cover (6) are all made of No. 45 steel.

10. A method for manufacturing a composite material perforated frame according to claim 1, characterized in that: The following steps are involved: S1: applying a release agent to the surface of the inner petal module group and the positioning block (9), laying a 2 mm thick prepreg around the positioning block (9) and installing it in the center of the base (11); S2: Apply 2 mm thick prepreg on the upper surface, inner side surface and stepped recess of each module (10) of the inner split module, use the prepreg to level the stepped recess on the outer side surface, and then install the inner split module on the base (11); S3: Laying 1.2 mm prepreg on the upper surface of the module (10) and the positioning block (9), and then laying 1.8 mm prepreg on the top and side surfaces of the inner petal module and the top surface of the positioning block; S4: Install the outer flap module around the inner flap module, and then install the gland (6) on top of the inner flap module; S5: vacuum the entire mold bag for pre-compaction, and demould after curing.

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