Composite material cross I-beam and forming die and manufacturing method thereof

Abstract

The invention provides a composite material cross-shaped I beam and a manufacturing method thereof, and belongs to the technical field of composite material forming. The problems that an existing mold is difficult to achieve cross-shaped I-beam forming, laying operation is complex, the appearance quality cannot meet the requirement easily, and quality defects are prone to occurring are solved. The cross-shaped I-shaped beam comprises a cross-shaped I-shaped beam body and a forming mold of the cross-shaped I-shaped beam body, the cross-shaped I-shaped beam body is made of carbon fiber composite materials, the cross-shaped I-shaped beam body is of an integrally-formed structure and comprises wing plates and a web plate, the wing plates are arranged on the top face and the bottom face of the web plate, the wing plates are perpendicular to the web plate, and the web plate is arranged on the web plate. The forming die comprises glands and a module set, the glands are arranged on the top face and the bottom face of the module set, cross-shaped grooves are formed in the top face and the bottom face of the module set, cross-shaped protrusions are arranged on the connecting faces of the glands and the module set, and the cross-shaped protrusions are matched with the cross-shaped grooves. The device is mainly used for machining the I-shaped beam.

Description

Technical Field

[0001] The invention belongs to the technical field of composite material molding, and in particular relates to a composite material cross-shaped I-beam and a manufacturing method thereof. Background Art

[0002] I-beams are beam-plate forms frequently used in aerospace composite structures. In the current field of composite I-beam manufacturing, traditional molds generally have many limitations. The core function of existing I-beam molds is basically limited to shaping the external geometric shape of the I-beam to meet the most basic assembly size requirements. However, from the perspective of mechanical properties, this type of mold only achieves the construction of the appearance, but ignores the adaptability of the internal structure to the mechanical bearing requirements. Due to the inability to accurately control the direction, sequence and proportion of the fiber layup, the internal fiber structure of the manufactured I-beam is chaotic or unreasonable. When subjected to actual force, the stress distribution is uneven, and stress concentration points are very likely to occur, which in turn causes strength shortcomings. For example, when subjected to large bending and shear loads, the I-beam may crack or even break prematurely, and the reliability and stability of the structure cannot be guaranteed.

[0003] At the same time, in the manufacturing process, the fixed structural design of traditional molds makes its laying method rigid and difficult to flexibly adjust according to different working conditions and shape requirements. When faced with the changing mechanical environment in fields such as aerospace and high-end mechanical equipment manufacturing, it is necessary to optimize the fiber laying according to the specific stress conditions, such as using specific angle laying in high-torque areas to enhance torsional performance, or changing the laying density in high-pressure areas to improve compressive strength. The existing molds cannot provide the corresponding operational convenience, which seriously restricts the application expansion of composite I-beams in high-performance demand scenarios. Summary of the invention

[0004] In view of this, the present invention aims to propose a composite material cross I-beam and a manufacturing method thereof, so as to solve the problems that the existing mold is difficult to realize the forming of the cross I-beam, the laying operation is complicated, the appearance quality is difficult to meet the requirements, and quality defects are prone to occur.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a composite material cross-shaped I-beam, the cross-shaped I-beam adopts carbon fiber composite material, the cross-shaped I-beam is an integrally formed structure, the outer contour of the cross-shaped I-beam is conical, it includes wing plates and web plates, the wing plates and web plates are both cross-shaped, the top and bottom surfaces of the web plates are both provided with wing plates, the wing plates and web plates are both cross-shaped, and the wing plates and web plates are perpendicular to each other.

[0006] Furthermore, the wing plate includes an upper wing plate and a lower wing plate, a web plate is arranged between the upper wing plate and the lower wing plate, the upper wing plate is arranged parallel to the lower wing plate, and the web plate is perpendicular to the upper wing plate and the lower wing plate respectively.

[0007] Furthermore, the thickness of the wing plate and the web plate are both 5 mm, the length of the upper wing plate is 99 mm, and the length of the lower wing plate is 108 mm.

[0008] A forming die for a composite material cross-shaped I-beam comprises a pressure cover and a module group, wherein the top and bottom surfaces of the module group are both provided with pressure covers, and the top and bottom surfaces of the module group are both provided with cross-shaped grooves, the inner side of the groove is a conical surface, a cross-shaped protrusion is provided on the surface of the pressure cover, and a conical surface is provided on the outer side of the cross-shaped protrusion, the cross-shaped protrusion is embedded in the cross-shaped groove, and the outer conical surface of the cross-shaped protrusion corresponds to the inner conical surface of the cross-shaped groove.

[0009] Furthermore, the module group is a cylinder, and the length of the cross-shaped groove on the top surface of the module group is smaller than the length of the cross-shaped groove on the bottom surface.

[0010] Furthermore, the module group includes four completely identical modules, the outer side of the module is cylindrical, the inner top surface and the bottom surface are both provided with grooves, the length of the inner top surface groove is smaller than the length of the inner ground groove, and the inner side of the groove is a conical surface.

[0011] Furthermore, the gland includes an upper gland and a lower gland, and a cross-shaped protrusion is provided on the bottom surface of the upper gland and the top surface of the lower gland.

[0012] Furthermore, the outer contours of the upper pressure cover and the lower pressure cover are circular.

[0013] Furthermore, the gland and several modules are all made of 45# steel.

[0014] A method for forming a composite material cross-shaped I-beam, using a forming die for the composite material cross-shaped I-beam, comprises the following steps:

[0015] S1: Apply release agent to the upper gland, lower gland and module surface;

[0016] S2: Lay prepreg in the grooves on the top and bottom surfaces of the module. The prepreg is a carbon fiber composite material. The prepreg is completely bonded to the groove surfaces on the top and bottom surfaces of the module. When the laying thickness reaches 1.5 mm, only lay the prepreg in the groove on the bottom surface of the module until the thickness of the prepreg in the groove on the bottom surface of the module reaches 5 mm.

[0017] S3: The modules for laying prepreg are assembled on the lower pressure cover;

[0018] S4: Lay prepreg in the gap between adjacent modules. When the laying height reaches the height of the groove on the top surface of the module, continue to lay prepreg in the groove on the top surface of the module to make the thickness of the prepreg in the groove on the top surface of the module reach 5mm.

[0019] S5: Install the upper gland on the assembled module;

[0020] S6: The forming mold is pre-compacted and then solidified, and then cooled and demoulded. The upper cover, the module and the lower cover are demoulded in sequence, and the blank is polished smooth after demoulding.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The cross-shaped I-beam of the present invention solves the problem that the flexibly designed ply cannot be realized while taking into account the mechanical properties of the I-beam and the cross-shaped shape;

[0023] 2. The cross-shaped I-beam of the present invention adopts an integrated molding technology to ensure the mechanical properties and shape accuracy of the I-beam;

[0024] 3. The forming die of the cross-shaped I-beam of the present invention not only improves the production efficiency and product quality of the cross-shaped I-beam, but also expands the performance and reliability of the cross-shaped I-beam in engineering applications, and has a wide range of application prospects;

[0025] 4. The cross-shaped I-beam forming mold of the present invention has a simple combination form, low operation difficulty and short single-piece production cycle;

[0026] 5. The cross-shaped I-beam and its forming mold described in the present invention solve the problems that the existing fixed structure molds are difficult to realize the forming of the cross-shaped I-beam and the operation is complicated during laying, the appearance quality is difficult to meet the requirements, and defects are prone to occur and cannot pass non-destructive testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] 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:

[0028] Figure 1 This is a schematic diagram of the axial structure of a composite material cross-shaped I-beam according to the present invention;

[0029] Figure 2 This is a schematic diagram of the top structure of a composite material cross-shaped I-beam according to the present invention;

[0030] Figure 3 This is a schematic diagram of the front structure of a composite material cross-shaped I-beam according to the present invention;

[0031] Figure 4 An exploded view of a forming die for a composite material cross-shaped I-beam according to the present invention;

[0032] Figure 5 It is a schematic diagram of the top structure of a forming die for a composite material cross-shaped I-beam according to the present invention;

[0033] Figure 6 It is a front structural schematic diagram of a forming die of a composite material cross-shaped I-beam according to the present invention;

[0034] Figure 7 It is a schematic cross-sectional structure diagram of a forming die for a composite material cross-shaped I-beam according to the present invention;

[0035] Figure 8 This is a schematic diagram of the axial structure of a module of a forming die for a composite material cross-shaped I-beam according to the present invention;

[0036] Fig. 9 This is a schematic diagram of the front structure of a module of a forming die for a composite material cross-shaped I-beam according to the present invention;

[0037] Fig.10 It is a schematic diagram of the top structure of a module of a forming die for a composite material cross-shaped I-beam according to the present invention;

[0038] Fig.11 This is a schematic diagram of the bottom structure of a module of a forming mold for a composite material cross-shaped I-beam according to the present invention;

[0039] Fig.12 It is a schematic diagram of the top structure of a module group of a forming die for a composite material cross-shaped I-beam according to the present invention;

[0040] Fig.13 It is a schematic cross-sectional structure diagram of a module group of a forming die for a composite material cross-shaped I-beam according to the present invention;

[0041] Fig.14 It is a front structural schematic diagram of a module group of a forming die for a composite material cross-shaped I-beam according to the present invention;

[0042] Fig.15 It is a front structural schematic diagram of an upper gland of a forming die for a composite material cross-shaped I-beam according to the present invention;

[0043] Fig.16 It is a schematic diagram of the bottom surface structure of an upper gland of a forming die for a composite material cross-shaped I-beam according to the present invention;

[0044] Fig.17 It is a front structural schematic diagram of a lower pressure cover of a forming die for a composite material cross-shaped I-beam according to the present invention;

[0045] Fig.18 The figure is a schematic diagram of the top structure of a lower pressure cover of a forming die for a composite material cross-shaped I-beam according to the present invention.

[0046] In the figure:

[0047] 1. Upper wing plate; 2. Web plate; 3. Lower wing plate; 4. Upper pressure cover; 5. Lower pressure cover; 6. First module; 7. Second module; 8. Third module; 9. Fourth module. DETAILED DESCRIPTION

[0048] 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.

[0049] See also Figure 1-3 The present embodiment describes a composite cross I-beam, wherein the cross I-beam is made of carbon fiber composite material, and the cross I-beam is an integrally formed structure. The cross I-beam formed by using carbon fiber composite material can withstand a large load, is light in weight and has a high product quality. The cross I-beam has a conical outer contour, and includes wing plates and a web 2. Both the wing plates and the web 2 are cross-shaped, and the top and bottom surfaces of the web 2 are provided with wing plates, and both the wing plates and the web are cross-shaped, and the wing plates are perpendicular to the web 2, thereby improving the strength and durability of the overall structure of the cross I-beam.

[0050] The wing plate includes an upper wing plate 1 and a lower wing plate 3, a web 2 is arranged between the upper wing plate 1 and the lower wing plate 3, the upper wing plate 1 is arranged parallel to the lower wing plate 3, the web 2 is respectively perpendicular to the upper wing plate 1 and the lower wing plate 3, the web 2 can resist bending moment, and the upper wing plate 1 and the lower wing plate 3 provide supporting force.

[0051] The thickness of the wing plate and the web plate 2 are both 5 mm, the length of the upper wing plate 1 is 99 mm, and the length of the lower wing plate 3 is 108 mm.

[0052] See also Figure 4-18 This embodiment describes a forming mold for a composite material cross-shaped I-beam, which includes a pressure cover and a module group. The top and bottom surfaces of the module group are both provided with pressure covers, and the pressure covers are used to apply pressure to ensure that the composite material is filled and cured into a predetermined shape. The top and bottom surfaces of the module group are both provided with cross-shaped grooves, and the inner side of the groove is a conical surface. The surface of the pressure cover is provided with a cross-shaped protrusion, and the outer side of the cross-shaped protrusion is provided with a conical surface. The cross-shaped protrusion fits with the cross-shaped groove, and the outer conical surface of the cross-shaped protrusion corresponds to the inner conical surface of the cross-shaped groove, thereby ensuring that the composite material is evenly distributed in the mold.

[0053] The module group is a cylinder, and the length of the cross-shaped groove on the top surface of the module group is smaller than the length of the cross-shaped groove on the bottom surface.

[0054] The module group includes four completely identical modules 6, the outer side of the module 6 is cylindrical, and grooves are arranged on the inner top surface and the inner bottom surface. The length of the inner top surface groove is smaller than the length of the inner ground groove, and the inner side of the groove is a conical surface. This modular mold design provides flexibility, and the shape and size of the mold can be adjusted according to different I-beam design requirements. By replacing or resetting the size of the module 6, it can quickly adapt to different production needs, thereby improving production efficiency and reducing costs.

[0055] The gland includes an upper gland 4 and a lower gland 5 , and a cross-shaped protrusion is disposed on the bottom surface of the upper gland 4 and the top surface of the lower gland 5 .

[0056] The outer contours of the upper pressure cover 4 and the lower pressure cover 5 are circular, and the circular shape allows the mold to be subjected to uniform force in all directions, which helps to reduce shape deviations caused by uneven pressure.

[0057] The gland and the module 6 are both made of 45# steel, which ensures that the mold can withstand the necessary pressure and heat during the molding process and avoids brittle cracking during use.

[0058] A method for manufacturing a composite material cross-shaped I-beam, using a forming die for the composite material cross-shaped I-beam, comprises the following steps:

[0059] S1: Apply a release agent to the surfaces of the upper pressure cover 4, the lower pressure cover 5 and the module 6 to reduce mold wear and ensure the quality of the workpiece;

[0060] S2: Lay prepreg in the grooves on the top and bottom surfaces of the module 6. The prepreg is a carbon fiber composite material. The prepreg is completely attached to the surface of the module 6 without bubbles and wrinkles. The prepreg is laid at an angle of 90° and ±45°, that is, the fiber direction of the prepreg is 90° or ±45° relative to the surface of the module 6. When the laying thickness reaches 1.5 mm, the prepreg is only laid in the groove on the bottom surface of the module 6. The prepreg is laid at 0°, that is, the fiber direction of the prepreg is parallel to the surface of the module 6, until the thickness of the prepreg in the groove on the bottom surface of the module 6 reaches 5 mm;

[0061] S3: Assemble the modules 6 with prepreg laid on the lower gland 5, that is, assemble four identical modules 6 with prepreg laid on the lower gland 5, and ensure that the cross-shaped protrusion on the top surface of the lower gland 5 is engaged with the cross-shaped groove of the module group, so as to form the lower wing plate 3 of the I-beam during the curing process;

[0062] S4: Lay prepreg in the gap between adjacent modules 6, and lay the prepreg in the 0° direction, that is, the prepreg fiber direction is parallel to the surface of the module 6. When the laying height reaches the height of the groove on the top surface of the module 6, continue to lay the prepreg in the groove on the top surface of the module 6, so that the thickness of the prepreg in the groove on the top surface of the module 6 reaches 5mm, and then trim it with a tool to ensure that the edge is smooth without burrs or irregular protrusions;

[0063] S5: Install the upper gland 4 on the assembled module 6, ensuring that the cross-shaped protrusion on the bottom surface of the upper gland 4 is engaged with the groove of the module 6, so as to form the upper wing plate 1 of the I-beam during the curing process;

[0064] S6: vacuumize the bag of the forming mold to achieve pre-compaction, and then solidify the forming mold after pre-compaction, that is, keep it at 100°C for two hours, then increase the temperature to 150°C and keep it for another two hours. After solidification, cool and demould. It needs to be cooled in an autoclave. Usually, the temperature of the forming mold drops to no more than 30°C from room temperature. After cooling and molding, demould it in sequence according to the upper pressure cover 4, the four modules 6 and the lower pressure cover 5. After demoulding, the blank is polished smooth to obtain a composite material cross-shaped I-beam.

[0065] The embodiments of the present invention disclosed above are only used to help illustrate the present invention. The embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods 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 cross-shaped I-beam, characterized in that: The cross-shaped I-beam is made of carbon fiber composite material, is an integrally formed structure, has a conical outer contour, comprises a wing plate and a web (2), both of which are cross-shaped, and the top and bottom surfaces of the web (2) are provided with wing plates, both of which are cross-shaped, and the wing plates and the web (2) are perpendicular to each other.

2. A cross-shaped I-beam according to claim 1, characterized in that: The wing plate comprises an upper wing plate (1) and a lower wing plate (3), a web plate (2) is arranged between the upper wing plate (1) and the lower wing plate (3), the upper wing plate (1) is arranged parallel to the lower wing plate (3), and the web plate (2) is perpendicular to the upper wing plate (1) and the lower wing plate (3), respectively.

3. A cross-shaped I-beam according to claim 2, characterized in that: The thickness of the wing plate and the web (2) are both 5 mm, the length of the upper wing plate (1) is 99 mm, and the length of the lower wing plate (3) is 108 mm.

4. A forming die for a composite material cross-shaped I-beam as claimed in claim 1, characterized in that: It includes a pressure cover and a module group. The top and bottom surfaces of the module group are both provided with pressure covers. The top and bottom surfaces of the module group are both provided with cross-shaped grooves. The inner side of the groove is a cone surface. A cross-shaped protrusion is provided on the surface of the pressure cover. A cone surface is provided on the outer side of the cross-shaped protrusion. The cross-shaped protrusion is embedded in the cross-shaped groove. The outer cone surface of the cross-shaped protrusion corresponds to the inner cone surface of the cross-shaped groove.

5. The forming die of a composite material cross-shaped I-beam according to claim 4, characterized in that: The module group is a cylinder, and the length of the cross-shaped groove on the top surface of the module group is smaller than the length of the cross-shaped groove on the bottom surface.

6. The forming die of a composite material cross-shaped I-beam according to claim 4, characterized in that: The module group comprises four identical modules (6), the outer side of the module (6) is cylindrical, the inner top surface and the bottom surface are both provided with grooves, the length of the inner top surface groove is smaller than the length of the inner ground groove, and the inner side of the groove is a conical surface.

7. The forming die of a composite material cross-shaped I-beam according to claim 4, characterized in that: The pressure cover comprises an upper pressure cover (4) and a lower pressure cover (5), and a cross-shaped protrusion is provided on the bottom surface of the upper pressure cover (4) and the top surface of the lower pressure cover (5).

8. The forming die of a composite material cross-shaped I-beam according to claim 7, characterized in that: The outer contours of the upper pressure cover (4) and the lower pressure cover (5) are circular.

9. The forming die of a composite material cross-shaped I-beam according to claim 4, characterized in that: The gland and the module (6) are both made of 45# steel.

10. A method for forming a composite material cross-shaped I-beam as claimed in claim 1, characterized in that: The following steps are involved: S1: Apply a release agent to the surfaces of the upper gland (4), the lower gland (5) and the module (6); S2: Laying prepreg in the grooves on the top and bottom surfaces of the module (6), the prepreg being a carbon fiber composite material, so that the prepreg is completely in contact with the surface of the grooves on the top and bottom surfaces of the module (6). When the laying thickness reaches 1.5 mm, the prepreg is only laid in the groove on the bottom surface of the module (6) until the thickness of the prepreg in the groove on the bottom surface of the module (6) reaches 5 mm; S3: The module (6) for laying the prepreg is assembled on the lower gland (5); S4: Laying prepreg in the gap between adjacent modules (6), and when the laying height reaches the height of the groove on the top surface of the module (6), continue to lay the prepreg in the groove on the top surface of the module (6), so that the thickness of the prepreg in the groove on the top surface of the module (6) reaches 5 mm; S5: Installing the upper gland (4) on the assembled module (6); S6: Pre-compacting the forming mold and then curing it, cooling and demoulding it after curing, demoulding it in the order of the upper pressure cover (4), the module (6) and the lower pressure cover (5), and polishing the blank to make it smooth after demoulding.

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