A kind of reinforced composite thin-walled part based on metal core plate and its forming process

Abstract

This invention relates to the field of thin-walled component molding technology, and discloses a molding process for thin-walled components based on a metal core plate reinforced composite material. The process includes the following steps: A resin-free process is performed on glass fiber dry cloth and steel according to a layup sequence using a one-step molding process. The fiber network has excellent conformability, allowing the fibers to be evenly distributed on the surface of the steel. A resin-based material is then used to impregnate the steel containing the fiber network. The fiber network has capillary action, guiding the flow of the resin-based material and ensuring uniform resin distribution between the fiber bundles, rather than disordered accumulation, thus avoiding resin aggregation or fiber depletion. The invention also includes a thin-walled component. This invention, through a one-step molding process, performs resin-free processing on the fiber network and steel, evenly distributing the fibers on the surface of the steel, improving the homogeneity of fiber distribution, and is suitable for various forms of thin-walled components.

Description

Technical Field

[0001] This invention relates to the field of thin-walled part forming technology, specifically to a thin-walled part of reinforced composite material based on a metal core plate and its forming process. Background Technology

[0002] Traditional thin-walled parts are made of metal, and the processes involved are mostly sheet metal-related methods such as stamping, bending, and welding. Traditional metal materials have advantages such as stable and reliable mechanical properties and mature forming and processing technologies. Their main disadvantages are: weight disadvantage, corrosion sensitivity, thin-wall effect (insufficient stiffness, limited forming limits, and high welding difficulty), and fatigue performance with high sensitivity and significant stress concentration at product shape notches.

[0003] A new composite thin-walled part is proposed, which solves the above-mentioned problems by coating the surface of a metal material with resin. The preparation process is as follows: 1. Spraying process: Short fibers and resin (usually polyester) are sprayed onto the mold surface simultaneously using a special spray gun, followed by manual rolling to degas, impregnate, and compact. 2. Resin transfer molding and its variations: A dried reinforcing material preform is placed in a closed mold. After the mold is closed, resin is injected into the mold cavity under pressure or vacuum to impregnate the fibers and cure. Variations include: vacuum-assisted resin infusion, high-pressure RTM, Light RTM, etc. 3. Fiber winding: Continuous fiber bundles impregnated with resin are wound around a rotating mandrel along a predetermined path. After achieving the desired thickness, the mandrel is cured and demolded.

[0004] While spraying can utilize various materials, it is prone to issues such as low and uneven fiber content, high resin content, and poor product performance (low strength and stiffness). Furthermore, it suffers from severe VOC problems, a harsh working environment, and significant health risks for workers. Resin transfer molding and its variations, as well as fiber winding, can improve fiber homogeneity. However, for the former, complex preform designs or poor permeability can still lead to resin adhesion difficulties, and the resin adhesion process places complex requirements on mold equipment. The latter has limited application scope when used with non-rotating bodies or complex curved surfaces.

[0005] It is evident that there is an urgent need for a molding process that features uniform fiber distribution, low resin content, and wide applicability to prepare thin-walled composite parts. Summary of the Invention

[0006] The purpose of this invention is to provide a reinforced composite thin-walled part based on a metal core board and its molding process, so as to solve the technical problems of uneven surface fiber distribution and poor resin adhesion in the prior art, which leads to high processing difficulty.

[0007] To solve the above-mentioned technical problems, the present invention specifically provides the following technical solution: This invention provides a molding process for thin-walled reinforced composite parts based on a metal core plate, comprising the following steps: S100. Short fibers are pre-processed into glass fiber dry cloth with a fiber network. Through a one-time molding process, the glass fiber dry cloth and steel are processed without resin according to the layup sequence. The fiber network has excellent conformability and the fibers can be evenly distributed on the surface of the steel. S200. A resin-based material is used to impregnate a steel containing a fiber network. The fiber network has a capillary effect, which can guide the flow of the resin-based material, so that the resin is evenly distributed between the fiber bundles instead of being disorderly piled up, thus avoiding resin aggregation or fiber depletion. S300, Curing: Based on the good permeability of the fiber network, the glass fiber dry cloth and the resin base material form a homogeneous integrated composite structure, which reduces stress concentration and microcrack generation inside the cured layer. S300, demolding, to obtain a thin-walled part with a "fiber resin-metal-fiber resin" sandwich structure.

[0008] In a preferred embodiment of the present invention, in step S100, the layup sequence is: dry glass fiber cloth, steel, dry glass fiber cloth.

[0009] As a preferred embodiment of the present invention, step S100 further includes the following step: S101. The corners of the bending area of ​​the steel are stamped to form multiple bends in the inner corner of the steel. S102. Punch holes at the corners of the bending area of ​​the steel to form several rows of holes in the bending area of ​​the steel, so as to reduce the springback rate of the steel.

[0010] As a preferred embodiment of the present invention, step S100 further includes the following step: S103. Before injection, glass fiber is passed through the punch to firmly fix the glass fiber dry cloth to the steel, preventing the glass fiber dry cloth from shifting or deviating during high-pressure injection, thereby ensuring the symmetry and consistency of fiber distribution in the product composite structure.

[0011] The present invention also provides a thin-walled part manufactured by a one-time molding process of a reinforced composite material based on a metal core plate, comprising: A steel core plate, wherein the steel core plate is a thin metal sheet or metal mesh with a predetermined shape; A fiber reinforcement layer, which is composed of dry glass fiber cloth, the dry glass fiber cloth having a network structure with gaps, and the fiber reinforcement layer uniformly covers and adheres to the surface of the steel core plate; A resin curing layer is formed by curing liquid resin. The resin uniformly impregnates and fills the gaps in the glass fiber dry cloth and forms a curing layer of uniform thickness on the surface of the steel core plate. The glass fiber dry cloth is uniformly adhered to the surface of the steel core board by conformal deformation, and the cured layer is uniformly distributed by the network structure of the glass fiber dry cloth, so that the fiber reinforcement layer and the resin cured layer form a homogeneous integrated composite structure on the surface of the steel core board.

[0012] As a preferred embodiment of the present invention, the fiber reinforcement layer comprises two layers of glass fiber dry cloth, which are respectively disposed on the upper and lower sides of the steel core plate, and the edges of the glass fiber dry cloth cover the corners of the steel core plate, so that the steel core plate is completely wrapped by the fiber reinforcement layer.

[0013] As a preferred embodiment of the present invention, the bending area of ​​the steel core plate is provided with several rows of punches to reduce springback stress.

[0014] In a preferred embodiment of the present invention, the glass fiber dry cloths located above and below the steel core plate are connected together through the punch holes, and the glass fiber dry cloths are sewn together with glass fiber thread.

[0015] As a preferred embodiment of the present invention, the resin curing layer is a curing layer formed by curing any one or more of polyurethane-based resin, epoxy resin or nylon resin.

[0016] In a preferred embodiment of the present invention, the surface of the steel core plate is provided with an electrophoretic layer or a zinc-nickel plating layer, wherein the thickness of the electrophoretic layer is... The thickness of the zinc-nickel plating layer .

[0017] Compared with the prior art, the present invention has the following advantages: This invention preprocesses short fibers into a fiber web and uses a one-time molding process to process the fiber web and steel without resin. Because the fiber web has excellent conformability, it can ensure that the fibers are evenly distributed on the surface of the steel. Before mold closing and glue injection, glass fiber is used to firmly fix the dry cloth to the steel, preventing the fiber cloth from shifting or deviating during high-pressure glue injection, thus ensuring the symmetry and consistency of fiber distribution in the product's fixing layer. This invention uses resin-based materials to impregnate steel containing fiber networks. The fiber network has good permeability and slurry coating ability. Its network structure has capillary action to guide the resin flow, so that the resin is evenly distributed between the fiber bundles instead of being disorderly piled up. This avoids the resin aggregation or fiber depletion phenomenon commonly seen in spraying processes, ensures uniform curing layer thickness, and reduces internal stress concentration and the generation of micro-cracks. The thin-walled component provided by this invention includes a steel core plate, a fiber reinforcement layer, and a resin curing layer. The glass fiber dry cloth is directly and uniformly adhered to the steel surface through "shape-following deformation" rather than being simply stacked. The resin material passes through the gaps in the fiber network to directly contact and bond to the steel surface. This "fiber-resin-metal-fiber-resin" sandwich structure forms a truly "integrated" structure through the dual effects of physical bonding of the fiber network and chemical bonding of the resin curing, solving the problems of easy delamination and weak interfacial bonding in traditional composite metal materials. Attached Figure Description

[0018] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0019] Figure 1 A schematic flow diagram of a one-time molding process for a thin-walled reinforced composite material part based on a metal core plate is provided for this invention. Figure 2 A structural schematic diagram of the steel plate is provided for this invention; Figure 3 A schematic diagram illustrating the adjustment of the steel plate angle is provided for this invention; Figure 4 This invention provides a schematic diagram of the structure of the steel plate after stamping; Figure 5 A cross-sectional structural diagram of a thin-walled component is provided for this invention.

[0020] The labels in the diagram represent the following: 1-Steel core board; 2-Fiber reinforcement layer; 3-Resin curing layer; 4-Punching. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] like Figure 1 As shown, the present invention provides a molding process for thin-walled reinforced composite materials based on a metal core plate, comprising the following steps: S100. Short fibers are pre-processed into glass fiber dry cloth. The glass fiber dry cloth has a network structure with gaps, through which liquid resin materials can pass. Through a one-step molding process, the fiberglass dry cloth and steel are processed without resin according to the layup sequence of fiberglass dry cloth + steel + fiberglass dry cloth. The fiber network has excellent conformability and the fibers can be evenly distributed on the surface of the steel to produce the primary part. The primary component is placed into the molding die and molded. During the molding process, the fiberglass cloth and steel conform to the shape to produce the preform. S200. The resin is injected into the molding die from bottom to top. The resin-based material is used to impregnate the steel containing the fiber network. The fiber network has a capillary effect, which can guide the flow of the resin-based material, so that the resin is evenly distributed between the fiber bundles instead of being disorderly piled up, thus avoiding resin aggregation or fiber depletion. After the S300 resin is filled and cured, the glass fiber dry cloth and the resin matrix form a homogeneous integrated composite structure based on the good permeability of the fiber network, which reduces stress concentration and micro-crack generation inside the cured layer. S300, demolding, to obtain a thin-walled part with a "fiber resin-metal-fiber resin" sandwich structure.

[0023] Steel forms a rigid reinforcing layer within the thin-walled component, providing basic mechanical support and impact resistance; at the same time, glass fiber reinforced composite material (resin + fiber) is used to wrap the outer layer, which distributes the load, improves surface stiffness and fatigue resistance, and significantly reduces weight compared to pure metal components.

[0024] In the one-step molding process, the glass fiber dry cloth is directly and uniformly adhered to the steel surface through "shape-following deformation" rather than simple stacking. This allows the subsequent resin to not only wet the fibers but also penetrate through the gaps in the fiber network to directly contact and bond to the steel surface, forming a dual connection effect of physical riveting (fiber network) and chemical bonding (resin curing). This solves the problems of easy delamination and weak interfacial bonding in traditional composite metal materials.

[0025] In the molding die, the resin can pass through the gaps in the network structure and come into contact with the steel. After the resin injection is completed, the resin can fill the gaps in the glass fiber dry cloth network structure, thereby forming a reinforcing layer with fiber structure and resin. The reinforcing layer is uniformly wrapped on the surface of the preform, which improves the performance of the thin-walled part.

[0026] The steel material is either steel plate or steel wire mesh.

[0027] Taking steel plate as an example, the formula for the deformation pressure of steel plate during the preforming process is as follows: P=650s 2 L / (1000V) Where s is the plate thickness (mm), L is the bending length (mm), and V is the V-groove width (mm).

[0028] For example, with a 1.0mm thick steel plate and a bending length of 1000mm, if V=6mm, the required pressure is approximately 32.5 tons.

[0029] Taking the wet molding process of polyurethane-based glass fiber reinforced materials as an example, for a product with a wall thickness of 2mm and a projected area of ​​1㎡, the required molding pressure is 150-250 tons. This tonnage is much higher than the pressure required for the deformation of thin steel sheet metal, so it is entirely feasible to perform plastic deformation operations on flat steel sheets in composite material molds.

[0030] Furthermore, during the preforming molding process, the fiberglass dry cloth can deform along with the steel plate and wrap around its perimeter. Compared to directly spraying short fiber materials or short fiber resin composites into the steel, the fiberglass dry cloth can be distributed more evenly on the steel surface, unaffected by material concentration, spraying speed, or spraying volume; only the uniformity of the fiber network thickness needs to be considered. Existing textile technologies can ensure that the fiber dry cloth made from short fibers has a relatively uniform thickness.

[0031] Because the glass fiber dry cloth has some "gaps" inside, these gaps are a unique structure in the fiber network structure preparation process, allowing liquid resin to pass through. At the same time, it also has a certain deformation capacity, that is, the glass fiber dry cloth has a certain deformation capacity. During the stamping process, the glass fiber dry cloth conforms to the shape of the steel plate. When the bending angle of the steel plate is large, the glass fiber dry cloth can deform and conform accordingly. If there are uneven areas on the steel plate, the glass fiber dry cloth can also be embedded in the uneven areas of the steel plate.

[0032] After the precast component is placed into the mold, the glass fiber dry cloth is wrapped around the surface of the steel plate precast component. The glass fiber dry cloth has many gaps, and the liquid resin passes through the "gaps" and adheres to the steel plate. The liquid resin can be evenly hung between the steel plate and the mold under the action of the glass fiber dry cloth.

[0033] During the injection process, as the adhesive continuously enters the mold, it passes through the glass fiber dry cloth and fills the gaps. The fiber network has a capillary effect, which guides the flow of the resin matrix. The resin matrix wets the steel containing the fiber network. The fiber network has good permeability and slurry coating ability, which allows the resin to be evenly distributed on the fiber network. The thickness of the glass fiber dry cloth and the fiber distribution are relatively uniform, so the thickness of the resin adhesive wrapped on the steel plate is also relatively uniform, forming a reinforcing layer after curing.

[0034] Because the fibers are evenly distributed on the surface of the steel plate and the resin is evenly distributed within the fibers, the thickness of this reinforcing layer is uniform, and the fiber and resin distribution is uniform, thus achieving uniform encapsulation of the metal material.

[0035] This invention can be produced using a wet molding process or a device used in a resin transfer molding process. It is worth noting that the molding die is provided with several glue outlets. During the glue injection process, the resin enters the molding die from the glue outlets located at the bottom of the molding die. Negative pressure devices can be provided at other glue outlets to ensure that the resin can fill the glass fiber dry cloth.

[0036] In this invention, the resin impregnation is not affected by the specific shape of the steel, but only by the glass fiber dry cloth itself. The resin has good fluidity in the glass fiber dry cloth network structure, can be evenly distributed on the surface of the steel, and the adhesion process is not easily affected by the shape of the steel itself. It is suitable for various shapes of metal materials and has strong applicability.

[0037] In a preferred embodiment, to facilitate the forming process of the steel plate, some pretreatment steps are also included, specifically including the following steps: S101. The corners of the bending area of ​​the steel are stamped to form multiple bends in the inner corner of the steel. S102. Punch holes at the corners of the bending area of ​​the steel to form several rows of holes in the bending area of ​​the steel, so as to reduce the springback rate of the steel.

[0038] To facilitate the fixation of the fiberglass cloth to the surface of the steel and ensure conformal molding during the forming process, the following steps are also included: S103. Before injection, glass fiber is passed through the punch holes to firmly fix the glass fiber dry cloth to the steel to prevent the glass fiber dry cloth from moving or shifting during high-pressure injection, thereby ensuring the symmetry and consistency of fiber distribution in the product composite structure.

[0039] Steel plates can also be made of other metal materials, such as aluminum plates.

[0040] The colloid is a resin-based colloid, including but not limited to polyurethane-based resin, epoxy resin, nylon resin, etc.

[0041] Its main molding process mainly includes the following steps (taking wet molding as a composite material molding process as an example): 1. The pretreatment steps for the steel plate are as follows: Pick Figure 2 The steel plate shown has the following material requirements: steel plate thickness ≤ 0.7mm; electrophoresis coating on the steel plate surface with a coating thickness ≥ 30μm (or optional zinc-nickel plating after sandblasting, with a coating thickness ≥ 8μm); the steel plate layer can be replaced by woven steel mesh with a wire diameter ≤ 0.35mm, preferably made of stainless steel, in which case no other special surface treatment is required; the steel plate layer can also be replaced by perforated plate, and the material can be aluminum or other softer metals with higher strength.

[0042] Machining requirements: Cut the steel plate according to the product design. In the finished box-shaped product, the steel plate design shape can be as shown in the figure. If there are other avoidance requirements, such as avoiding the module area, or needing to use machining cutting parts after forming, the avoidance needs to be cut before electrophoresis.

[0043] In composite material product design, large corner radii are typically used to avoid stress concentration. Furthermore, to prevent the steel plate reinforcement from failing due to interference during mold closing, multiple internal bends in the steel plate are created, reducing the steel plate's springback rate. Therefore, the steel plate shape should avoid the rounded corners of the product's side facade. Figure 3 As shown.

[0044] When designing and machining the steel plate reinforcement layer, the thickness of the steel plate should be considered. Excessively thick steel plates will cause springback issues after the mold closes. While controlling the steel plate thickness, multiple openings need to be designed in the direction of the required deformation, such as... Figure 4 As shown 2. Layering The layering principle is: fiberglass dry cloth + steel plate reinforcement layer + fiberglass dry cloth, ensuring that the edges and corners of the steel plate are not exposed when entering the mold, and avoiding wear on the mold surface when closing the mold.

[0045] 3. Mold closing and preforming At this point, the mold is closed to pre-form the flat steel plate and initially shape the glass fiber reinforced fiber. No resin is involved, and the mold temperature can be maintained at the temperature for subsequent curing without the need for temperature adjustment, thus ensuring molding efficiency.

[0046] At this point, the mold closing pressure can be selected as 20%-30% higher than the calculated value of the steel plate plastic forming pressure.

[0047] 4. Glue injection The adhesive material can be selected based on material properties and customer requirements, including but not limited to polyurethane-based resin, epoxy resin, nylon resin, etc. If the steel plate reinforcement material in the middle is a whole steel plate, note that resin should not be sprayed directly onto the surface, as the steel plate will prevent the surface resin from wetting the underlying reinforcing fibers.

[0048] A glue outlet needs to be designed on the mold, and the bottom glue layer needs to be injected from the glue outlet of the lower mold. If the steel plate reinforcement material in the middle is steel mesh or dense perforated plate, it can be selected whether or not a glue outlet needs to be designed on the lower mold according to the actual situation.

[0049] If the molding process is selected as resin transfer molding, then injection ports can be designed in both the upper and lower molds in the traditional way.

[0050] 5. Curing and molding The molding parameters should refer to the temperature recommended in the selected composite material, and the curing time should be increased by 30%-50%.

[0051] 6. Machining When designing products, the edge of the steel plate reinforcement layer should be at least 10mm away from the machining edge to avoid exposing the steel plate to the air during machining operations, which could lead to product failure risks such as rusting and delamination.

[0052] The machining method can be laser processing or CNC machining, etc.

[0053] 7. Inspection / packaging / shipping.

[0054] The steel plate design can be divided into different parts on the same product, and it is not necessary to mold a whole steel plate. If it is difficult to position when divided into different parts, fiberglass sewing yarn can be used for simple sewing and fixing during the layering stage.

[0055] Existing composite material + pre-stamped steel plate integrated molding process requires preliminary work on the steel plate, such as stamping, welding, and electrophoresis. Complex metal thin-walled parts often suffer from scratches, rust, paint peeling, impact bulges, and deformation during transportation and storage, leading to the scrapping of the entire part. In contrast, this process only requires simple machining and electrophoresis (or plating) processes for the pretreatment of the steel plate, which facilitates transportation and storage.

[0056] By designing the steel plate to avoid the edges of the machining process, the material cost can be increased by a small amount. Compared with thin-walled parts made of all composite materials, the production cost only increases the price of the steel plate itself. The press mold closing process for preforming the steel plate has virtually no additional processing cost.

[0057] This embodiment utilizes the network structure of glass fiber dry cloth to guide resin flow (capillary action / permeability), so that the resin is evenly distributed between the fiber bundles instead of being randomly piled up. This avoids the resin aggregation or fiber depletion phenomenon commonly seen in spraying processes, ensuring uniform curing layer thickness and reducing internal stress concentration and the generation of microcracks.

[0058] Composite metal reinforced thin-walled parts are suitable for products including (but not limited to): automotive body panels (doors, hoods, roofs), battery pack housings, wind turbine blade housings, seat frames, bicycle frames, sports equipment, automotive exterior parts (bumpers, mudguards, spoilers), electrical component housings, bathroom fixtures, seat backs, automotive front-end modules, seat frames, battery trays, etc.

[0059] like Figures 2 to 5 As shown, the present invention also includes a thin-walled component comprising a steel core plate 1, a fiber reinforcement layer 2, and a resin curing layer 3, having a sandwich structure of "fiber resin-metal-fiber resin".

[0060] The steel core plate 1 is a thin metal plate or metal mesh with a predetermined shape. The fiber reinforcement layer 2 is made of glass fiber dry cloth, which has a network structure with gaps. The fiber reinforcement layer 2 is uniformly covered and attached to the surface of the steel core plate. The resin curing layer 3 is formed by curing liquid resin. The resin is uniformly impregnated and filled in the gaps of the glass fiber dry cloth, and a curing layer of uniform thickness is formed on the surface of the steel core plate 1.

[0061] Among them, the glass fiber dry cloth is uniformly attached to the surface of the steel core board 1 by conforming to the shape deformation, and the cured layer is uniformly distributed by the network structure of the glass fiber dry cloth, so that the fiber reinforcement layer 2 and the resin cured layer 3 form a homogeneous integrated composite structure on the surface of the steel core board 1.

[0062] The fiber reinforcement layer 2 includes two layers of glass fiber dry cloth, which are respectively disposed on the upper and lower sides of the steel core plate 1, and the edges of the glass fiber dry cloth cover the corners of the steel core plate 1, so that the steel core plate 1 is completely wrapped by the fiber reinforcement layer.

[0063] The bending area of ​​the steel core plate 1 is provided with several rows of punch holes 4 to reduce springback stress.

[0064] The fiberglass dry cloths located above and below the steel core plate 1 are connected together through punch holes 4, and the fiberglass dry cloths are sewn together with fiberglass thread.

[0065] The beneficial effects of this process are as follows: 1. Using thin-walled metal as a rigid skeleton provides basic mechanical support and impact resistance; at the same time, glass fiber reinforced composite material (resin + fiber) is used to wrap the outer layer to share the load, improve surface stiffness and fatigue resistance, and significantly reduce weight compared to pure metal parts. 2. The glass fiber dry cloth is directly and evenly adhered to the steel surface through "shape-following deformation" rather than simple stacking. This allows the subsequent resin to not only wet the fibers but also penetrate through the gaps in the fiber network to directly contact and bond to the steel surface, forming a dual connection effect of physical riveting (fiber network) and chemical bonding (resin curing). This solves the problems of easy delamination and weak interfacial bonding in traditional composite metal materials. 3. The bending area of ​​the steel core plate is perforated, and the fiber cloth is sewn and fixed by passing through the perforations: The design of bends or perforations in the bending area of ​​the steel breaks the continuity of the metal, releases the internal stress during the bending process, and solves the problem of dimensional accuracy caused by the easy springback of thin-walled metal parts after stamping. This makes the shape of the preform more stable, which is convenient for subsequent molding and glue injection. At the same time, before mold closing and glue injection, the dry cloth is firmly fixed to the steel with a homogeneous material (glass fiber), which prevents the fiber cloth from moving or shifting during high-pressure glue injection, and ensures the symmetry and consistency of the fiber distribution in the final appearance of the product.

[0066] The one-step molding process for thin-walled reinforced composite parts based on metal core plates in this embodiment involves laminating metal reinforcement materials and composite fibers in a flat state, and then pre-forming the steel plate layer in a composite material molding mold in one step. The glass fiber dry cloth has a uniform thickness and uniform glue injection gaps on the surface of the steel part, which can drive the resin glue to be evenly attached to the surface of the steel plate. After curing, a reinforcement layer with uniform fiber and resin distribution is formed on the surface of the thin steel plate, ensuring the homogeneity of the composite material on the surface of the metal reinforcement material. It is suitable for various forms of metal materials, improves product performance, allows for closed production, and eliminates the need for additional sheet metal molding processes, thus speeding up the production cycle.

[0067] The above embodiments are merely exemplary embodiments of this application and are not intended to limit this application. The scope of protection of this application is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to this application within its substance and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of this application.

Claims

1. A molding process for thin-walled reinforced composite parts based on a metal core plate, characterized in that, Includes the following steps: S100. Short fibers are pre-processed into glass fiber dry cloth with a fiber network. Through a one-time molding process, the glass fiber dry cloth and steel are processed without resin according to the layup sequence. The fiber network has excellent conformability and the fibers can be evenly distributed on the surface of the steel. S200. A resin-based material is used to impregnate a steel containing a fiber network. The fiber network has a capillary effect, which can guide the flow of the resin-based material, so that the resin is evenly distributed between the fiber bundles instead of being disorderly piled up, thus avoiding resin aggregation or fiber depletion. S300, Curing: Based on the good permeability of the fiber network, the glass fiber dry cloth and the resin base material form a homogeneous integrated composite structure, which reduces stress concentration and microcrack generation inside the cured layer. S300, demolding, to obtain a thin-walled part with a "fiber resin-metal-fiber resin" sandwich structure.

2. The molding process for thin-walled reinforced composite parts based on a metal core plate according to claim 1, characterized in that, In step S100, the layup sequence is: dry glass fiber cloth, steel, dry glass fiber cloth.

3. The molding process for thin-walled reinforced composite parts based on a metal core plate according to claim 1, characterized in that, Step S100 further includes the following steps: S101. The corners of the bending area of ​​the steel are stamped to form multiple bends in the inner corner of the steel. S102. Punch holes at the corners of the bending area of ​​the steel to form several rows of holes in the bending area of ​​the steel, so as to reduce the springback rate of the steel.

4. The molding process for thin-walled reinforced composite parts based on a metal core plate according to claim 3, characterized in that, Step S100 further includes the following steps: S103. Before injection, glass fiber is passed through the punch to firmly fix the glass fiber dry cloth to the steel, preventing the glass fiber dry cloth from shifting or deviating during high-pressure injection, thereby ensuring the symmetry and consistency of fiber distribution in the product composite structure.

5. A thin-walled part prepared by the molding process according to any one of claims 1-4, characterized in that, include: Steel core plate (1), wherein the steel core plate (1) is a thin metal sheet or metal mesh with a predetermined shape; Fiber reinforcement layer (2), the fiber reinforcement layer (2) is composed of glass fiber dry cloth, the glass fiber dry cloth is a network structure with gaps, the fiber reinforcement layer (2) uniformly covers and adheres to the surface of the steel core plate; The resin curing layer (3) is formed by curing liquid resin. The resin is uniformly impregnated and filled in the gaps of the glass fiber dry cloth and forms a curing layer of uniform thickness on the surface of the steel core plate (1). The glass fiber dry cloth is uniformly attached to the surface of the steel core plate (1) by conformal deformation, and the cured layer is uniformly distributed by the network structure of the glass fiber dry cloth, so that the fiber reinforcement layer (2) and the resin cured layer (3) form a homogeneous integrated composite structure on the surface of the steel core plate (1).

6. A thin-walled component according to claim 5, characterized in that, The fiber reinforcement layer (2) includes two layers of glass fiber dry cloth, which are respectively disposed on the upper and lower sides of the steel core plate (1), and the edges of the glass fiber dry cloth cover the corners of the steel core plate (1), so that the steel core plate (1) is completely wrapped by the fiber reinforcement layer.

7. A thin-walled component according to claim 6, characterized in that, The steel core plate (1) has several rows of punches (4) in the bending area to reduce springback stress.

8. A thin-walled component according to claim 7, characterized in that, The glass fiber dry cloths located above and below the steel core plate (1) are connected together through the punch (4), and the glass fiber dry cloths are sewn together by glass fiber thread.

9. A thin-walled component according to claim 5, characterized in that, The resin curing layer (3) is a curing layer formed by curing any one or more of polyurethane-based resin, epoxy resin or nylon resin.

10. A thin-walled component according to claim 5, characterized in that, The surface of the steel core plate (1) is provided with an electrophoretic layer or a zinc-nickel plating layer, the thickness of which is... The thickness of the zinc-nickel plating layer .

Images