Composite material mold and composite material forming method

Abstract

The present invention discloses a composite material mold and a composite material forming method. The composite material mold includes: a mold body, the mold body includes a bending portion and two straight portions; the straight portion is a rigid component, and the bending portion is an elastic component; an angle adjustment structure, and the angle adjustment structure is used to adjust the angle between the two straight portions. A composite material forming method uses a composite material mold as described above; the composite material forming method includes: adjusting the composite material mold so that the angle between the two straight portions is greater than the angle of the desired component; processing fiber-reinforced materials; laying polytetrafluoroethylene cloth and the desired materials, and then vacuuming; adjusting the composite material mold so that the angle between the two straight portions is equal to the angle of the desired component; continuing with subsequent steps; curing; and demolding. This solution can improve the surface consistency and quality of the finished product, improve the controllability of the production process, improve production efficiency, save materials and costs, and improve the appearance quality of the final product.

Description

Technical Field

[0001] The present invention relates to the technical field of composite material manufacturing, in particular to a composite material mould and a composite material forming method. Background Art

[0002] The low-altitude economy, an emerging economic model, encompasses a wide range of applications, including low-altitude tourism, air traffic, agriculture, logistics, emergency rescue, and surveying. The widespread adoption and development of these applications relies heavily on advances in aircraft technology, particularly innovations in materials technology. Against this backdrop, fiber-reinforced materials, as high-performance composite materials, have become key materials in the manufacture of low-altitude aircraft due to their excellent mechanical properties and lightweight characteristics. Fiber-reinforced materials offer exceptional properties, such as high strength, high modulus, low density, and designability. Compared to traditional metal materials (such as aluminum alloys and steel), they have higher specific strength and specific stiffness. These properties give fiber-reinforced materials significant advantages in the manufacture of lightweight, high-performance low-altitude aircraft. For example, drones and helicopters manufactured using fiber-reinforced composites not only significantly reduce their weight, improving fuel efficiency and battery life, but also enhance their load-carrying capacity and flight stability, thus meeting the demands of various applications within the low-altitude economy. Furthermore, fiber-reinforced composites exhibit excellent corrosion and fatigue resistance, enabling them to maintain structural integrity and performance stability over extended periods of time under complex and demanding environmental conditions. This is particularly important for low-altitude aircraft that often perform missions in complex outdoor environments. For example, drones used in the agricultural field often need to operate in humid environments with high pesticide concentrations. The corrosion resistance of fiber-reinforced materials can extend their service life and reduce maintenance costs.

[0003] With the rapid development of the low-altitude economy, performance requirements for low-altitude aircraft are becoming increasingly stringent, particularly in terms of lightweighting, durability, and environmental adaptability. The superior performance of fiber-reinforced composites in these areas makes them an ideal choice for low-altitude aircraft manufacturing, thereby driving the further development and application of the low-altitude economy. To better leverage the advantages of fiber-reinforced composites in the low-altitude economy, in-depth research and innovation in fiber-reinforced composite application technologies are urgently needed to meet the growing market demand. Widely used processes for forming advanced composite structures include autoclave and vacuum-assisted resin infusion. Autoclave molding utilizes high-temperature, compressed gas within the autoclave to generate pressure, heating and pressurizing the composite blank to achieve curing. The basic principle of vacuum-assisted resin infusion is to use negative vacuum pressure to infuse resin into preformed reinforcements. During the preforming stage, the reinforcements are placed in a mold, which is sealed to exclude air and maintain a vacuum. Then, resin is injected into the reinforcements under a specified pressure and cured under the specified temperature and pressure conditions, resulting in a composite component with the desired shape and properties. The efficiency and precision of these technologies provide reliable solutions for the preparation of complex structural components.

[0004] L-shaped molds are used in the autoclave process and vacuum-assisted resin infusion molding process. Existing L-shaped molds have gaps between each layer when laying fiber layers. After the mold is closed, vacuum is applied to eliminate the gaps and compact the fiber layers. As a result, the original length of fibers are tightened and wrinkled at the R corners, affecting the surface quality and performance of the final product. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a composite material mold and a composite material molding method to solve one or more technical problems existing in the prior art and at least provide a beneficial option or create conditions.

[0006] The solution of the present invention to solve its technical problems is:

[0007] Composite material molds, including:

[0008] A mold body, the mold body having a material side and an operating side, the mold body including a bent portion and two straight portions, the bent portion being disposed between the two straight portions; the straight portion being a rigid component, and the bent portion being an elastic component;

[0009] An angle adjustment structure is provided on the operating side, and both ends of the angle adjustment structure are respectively connected to the two straight portions. The angle adjustment structure is used to adjust the angle between the two straight portions. When the angle between the two straight portions changes, the bending radius of the bending portion changes.

[0010] Through the above technical solution, when the composite material mold of this solution is laid, the angle between the two straight parts is greater than the angle of the required component. When vacuuming, the composite material will produce wrinkles. After vacuuming is completed, the user adjusts the angle between the two straight parts through the angle adjustment structure, so that the bending radius of the bending part changes. In the process of changing the bending radius of the bending part, the wrinkles will gradually disappear. After adjusting to the angle of the required component, the composite material can be cured.

[0011] The composite material mold can improve the surface consistency and quality of the finished product, improve the controllability of the production process, improve production efficiency, save materials and costs, and improve the appearance quality of the final product.

[0012] As a further improvement of the above technical solution, the angle adjustment structure includes an adjusting drive member and two driving threaded rods, and the two driving threaded rods are respectively connected to the two straight parts; one end of the driving threaded rod is threadedly connected to the adjusting drive member, and the other end is connected to the straight part through an elastic structure or a movably connected; when the adjusting drive member rotates, the two driving threaded rods are driven to approach or move away from each other, thereby driving one end of the two straight parts to approach or move away from each other.

[0013] Through the above technical solution, the angle adjustment structure of this solution has a simple structure and is easy to process.

[0014] As a further improvement of the above technical solution, the adjustment drive member is provided with a rotation auxiliary groove for the tool to pass through.

[0015] Through the above technical solution, the user can insert the tool into the rotation auxiliary groove, and then drive the tool to rotate around the axis of the driving threaded rod to drive the adjustment drive member to rotate. By setting the rotation auxiliary groove, the user can rotate the adjustment drive member more easily.

[0016] As a further improvement of the above technical solution, a plurality of reinforcing ribs are fixed to the straight portion.

[0017] Through the above technical solution, a reinforcing rib is fixed to the straight portion, which can increase the strength of the straight portion, thereby preventing the straight portion from being deformed during the angle adjustment process.

[0018] A composite material molding method, using any of the composite material molds described above; the composite material molding method comprises:

[0019] Step a, adjusting the composite material mold so that the included angle between the two straight portions is greater than the angle of the desired component;

[0020] Step b, treating the fiber reinforcement material according to the composite material curing and molding process;

[0021] Step c, laying polytetrafluoroethylene cloth on the composite material mold, laying the required materials on the polytetrafluoroethylene cloth, sealing the outermost layer with high-temperature tape and vacuum bag, and evacuating;

[0022] Step d: adjusting the angles of the two straight portions of the composite material mold by the angle adjustment structure so that the included angle between the two straight portions is equal to the angle of the desired component, and during the adjustment process, wrinkles are gradually eliminated;

[0023] Step e: After removing wrinkles, continue to perform subsequent steps according to the process of composite material curing and molding;

[0024] Step f, setting a temperature curve or a temperature and pressure curve in the system, and then performing curing and molding according to the process;

[0025] Step g: After curing is completed and the temperature has cooled, the sample is taken out and demoulded.

[0026] Through the above technical solution, when the composite material mold of this solution is laid, the angle between the two straight parts is greater than the angle of the required component. When vacuuming, the composite material will produce wrinkles. After vacuuming is completed, the user adjusts the angle between the two straight parts through the angle adjustment structure, so that the bending radius of the bending part changes. In the process of changing the bending radius of the bending part, the wrinkles will gradually disappear. After adjusting to the angle of the required component, the composite material can be cured.

[0027] The composite material mold can improve the surface consistency and quality of the finished product, improve the controllability of the production process, improve production efficiency, save materials and costs, and improve the appearance quality of the final product.

[0028] As a further improvement of the above technical solution, the composite material curing molding process is a vacuum assisted resin infusion molding process or an autoclave molding process.

[0029] As a further improvement of the above technical solution, the composite material curing molding process is a vacuum assisted resin infusion molding process;

[0030] The step b is: cutting the high-performance fiber cloth, placing the fiber cloth in an oven after cutting, and drying the fiber cloth in the oven at high temperature;

[0031] The step e is as follows: turn on the vacuum pump, connect one end of the air tube to the vacuum pump, place the other end in the resin, use the vacuum negative pressure to draw the resin into the device, wait until the resin in the device is evenly infiltrated, and when there are no bubbles in the resin drawn out of the transparent air tube connected to the vacuum pump end, close the glue inlet.

[0032] As a further improvement of the above technical solution, the materials required in step c include a guide net, a release cloth, and a porous isolation film.

[0033] As a further improvement of the above technical solution, the composite material curing molding process is a composite material autoclave molding process;

[0034] The step b is: cutting the prepreg, placing the prepreg into a sealed bag after cutting, and storing it in a freezer.

[0035] As a further improvement of the above technical solution, the materials required in step c include release cloth, prepreg, porous isolation film, and suction adhesive.

[0036] The beneficial effects of the present invention are: improving the surface consistency and quality of the finished product, improving the controllability of the production process, improving production efficiency, saving materials and costs, and improving the appearance quality of the final product.

[0037] The invention is used in the technical field of composite material manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly describes the drawings required for describing the embodiments. Obviously, the drawings described only illustrate some embodiments of the present invention, not all of them. Those skilled in the art can derive other design solutions and drawings based on these drawings without inventive effort.

[0039] Figure 1 It is a schematic diagram of the overall structure of the composite material mold of the present invention.

[0040] In the figure, 100 is the mold body; 110 is the straight portion; 120 is the bending portion; 200 is the angle adjustment structure; 210 is the driving threaded rod; 220 is the adjustment driving member. DETAILED DESCRIPTION

[0041] The following will clearly and completely describe the concept, specific structure and technical effects of the present invention in combination with the embodiments and drawings, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention. In addition, all the connection / connection relationships mentioned in the text do not refer to the direct connection of components, but refer to the fact that a better connection structure can be formed by adding or reducing connection accessories according to the specific implementation situation. The various technical features in the invention can be combined interactively without conflicting with each other.

[0042] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0043] In the description of the present invention, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0044] Reference Figure 1 , a composite material mold includes a mold body 100 and an angle adjustment structure 200.

[0045] Both sides of the mold body 100 are respectively set as a material side and an operation side.

[0046] The mold body 100 includes a straight portion 110 and a bent portion 120 . There are two straight portions 110 , which are respectively disposed on both sides of the bent portion 120 . The straight portion 110 and the bent portion 120 are fixedly connected.

[0047] Specifically, the bending portion 120 is a structure of an elastic steel sheet, and the straight portion 110 is a structure in which a plurality of reinforcing ribs are fixed to the steel sheet structure, so that the straight portion 110 is a rigid component and is not easily deformed, thereby ensuring that the portion corresponding to the composite material and the straight portion 110 remains straight.

[0048] In other embodiments, the thickness of the straight portion 110 may be increased to prevent the straight portion 110 from being easily deformed. Those skilled in the art may select different structures according to actual needs to prevent the straight portion 110 from being easily deformed.

[0049] The angle adjustment structure 200 includes a driving threaded rod 210 and an adjusting driving member 220. The number of the driving threaded rods 210 is set to two. The two driving threaded rods 210 are respectively arranged on both sides of the adjusting driving member 220. The driving threaded rod 210 is threadedly connected to the adjusting driving member 220, and the thread options of the two driving threaded rods 210 are opposite.

[0050] In this embodiment, the end of the driving threaded rod 210 is connected to the straight portion 110 through an elastic sheet structure. In other embodiments, the driving threaded rod 210 can also be set to be rotatably connected to the straight portion 110. Those skilled in the art can choose the connection method between the driving threaded rod 210 and the straight portion 110 according to actual needs.

[0051] Specifically, in this embodiment, the adjusting drive member 220 is provided with a rotation-assisting groove. The user can insert a tool into the rotation-assisting groove, and then drive the tool to rotate around the axis of the driving threaded rod 210 to drive the adjusting drive member 220 to rotate. By providing the rotation-assisting groove, the user can rotate the adjusting drive member 220 more easily.

[0052] When the driving threaded rods 210 are driven to rotate, the two driving threaded rods 210 move in opposite directions, so that the two driving threaded rods 210 move closer to each other or farther away from each other.

[0053] Example 1:

[0054] This embodiment adopts a composite material vacuum assisted resin infusion molding process.

[0055] This embodiment includes the following steps:

[0056] Step a: Adjust the composite material mold so that the included angle (hereinafter referred to as R angle) between the two straight portions 110 is 110°, and clean the surface of the mold body 100 with alcohol to make it smooth;

[0057] Step b, cutting the carbon fiber unidirectional fabric (i.e., the fiber reinforced material), and after the carbon fiber unidirectional fabric is cut, placing the carbon fiber unidirectional fabric in an oven and drying it at a high temperature of 100° C. to achieve an effect of eliminating water vapor or moisture inside the carbon fiber unidirectional fabric;

[0058] Step c, laying a layer of polytetrafluoroethylene cloth on the composite material mold, laying a layer of guide mesh and a porous isolation membrane on the polytetrafluoroethylene cloth, and then laying a release cloth, laying a carbon fiber unidirectional cloth on the release cloth, and laying the release cloth, the porous isolation membrane, and the guide mesh on the carbon fiber unidirectional cloth in sequence (i.e., laying the layers in the order of guide mesh - porous isolation membrane - release cloth - carbon fiber unidirectional cloth - release cloth - porous isolation membrane - guide mesh), placing air pipes at both ends of the composite material mold, adding a spiral tube to the resin inlet end, and finally sealing the outermost layer with high-temperature tape and a vacuum bag; clamping the air pipe on the resin inlet side, vacuuming the other side for five minutes, and then turning off the vacuum pump;

[0059] Step d: Then adjust the R angle of the composite material mold to 90° so that there are no wrinkles at the chamfers of the composite material. Let the device stand for half an hour and observe whether there is any air leakage to ensure that the resin can evenly penetrate the fiber layer and reduce the formation of bubbles and defects.

[0060] Step e: Turn on the vacuum pump, connect one end of the air tube to the vacuum pump, place the other end in the resin, set the air pressure of the vacuum pump to -0.1 MPa, and use negative pressure to draw the resin into the device. After the resin in the device is evenly infiltrated and no bubbles are seen in the transparent air tube connected to the vacuum pump end, close the air tube on the side where the resin enters, and continue vacuuming for five minutes to achieve the purpose of making the resin uniform;

[0061] Step f, setting a temperature curve in the system according to the curing process curve, heating from room temperature to 80°C at a rate of 2°C / min and then keeping the temperature for 1 hour, then continuing to heat from 80°C to 120°C at a rate of 2°C / min and keeping the temperature for 1 hour, and finally cooling to room temperature at a rate of 1°C / min for curing and molding, and observing the temperature changes in real time;

[0062] Step g: After curing is completed and the temperature has cooled, the sample is taken out and demoulded.

[0063] Example 2:

[0064] In this embodiment, a composite material autoclave molding process is adopted.

[0065] This embodiment includes the following steps:

[0066] Step a: Adjust the R angle of the composite material mold to 120° and wipe the surface with alcohol to ensure the appearance quality of the final product;

[0067] Step b, cutting the prepreg, placing the prepreg into a sealed bag after cutting, and storing it in a freezer;

[0068] Step c: Laying a layer of polytetrafluoroethylene cloth on the composite material mold, laying a layer of release cloth on the polytetrafluoroethylene cloth, laying prepreg on the release cloth, pre-compacting each layer with a pressure roller, and vacuuming every 4 to 6 layers: laying a layer of release cloth + a porous isolation film + release cloth + suction adhesive on the prepreg during vacuuming; after the layers are laid, seal the outermost layer with high-temperature tape and a vacuum bag, and vacuum for 10 minutes;

[0069] Step d: Adjust the R angle of the composite material mold to 90°, remove wrinkles, and place it in the autoclave. After checking that everything is correct, start curing and omit step e.

[0070] Step f, setting the temperature curve and pressure curve in the system, and then performing curing and molding according to the autoclave process;

[0071] Step g: After curing is completed, the pressure is released and the temperature is cooled, the tank door is opened and the sample is taken out of the mold.

[0072] Compared with the prior art, the present invention has the following advantages:

[0073] 1) Fiber layer consistency: By changing the angle of the two straight portions 110 of the composite material mold, the bending radius of the bent portion is changed, which can effectively reduce wrinkles in the fiber layer at the corners during vacuum extraction, thereby improving the surface consistency and quality of the finished product.

[0074] 2) Process stability: Adjusting the corner angle of the composite material mold can reduce the instability caused by the wrinkles of the fiber layer at the corner and improve the controllability of the production process.

[0075] 3) Reduce scrap rate: By reducing wrinkles, the scrap rate in the production process can be significantly reduced, production efficiency can be improved, and materials and costs can be saved.

[0076] 4) Optimized finished product appearance: Reducing wrinkles in the fiber layer at the corners of the composite material helps improve the appearance quality of the final product, making it more in line with high-demand appearance standards and suitable for a wider range of applications.

[0077] 5) Process applicability: By optimizing the mold design to make it more suitable for the composite material curing molding process, it helps to expand the applicability of the process and enable it to more flexibly adapt to different products and production needs.

[0078] These advantages make this design more operable and economical in the vacuum infusion assisted molding process, helping to improve product quality and production efficiency.

[0079] This solution aims to eliminate wrinkle defects at the R corners during the molding of fiber-reinforced composite materials for complex components. After actual use and testing, it can solve the technical bottlenecks of low production efficiency and low product quality, and lay a technical foundation for the development of large and complex structural components made of composite materials.

[0080] The above specifically describes the preferred embodiments of the present invention, but the invention is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A composite material forming method, characterized in that: The composite material mold used in the composite material molding method includes: a mold body, the mold body is provided with a material side and an operating side, the mold body includes a bending portion and two straight portions, the bending portion is provided between the two straight portions; the straight portion is a rigid component, and the bending portion is an elastic component; an angle adjustment structure is provided on the operating side, the two ends of the angle adjustment structure are respectively connected to the two straight portions, the angle adjustment structure is used to adjust the angle between the two straight portions, and when the angle between the two straight portions changes, the bending radius of the bending portion changes; The composite material molding method using the composite material mold comprises the following steps: Step a, adjusting the composite material mold so that the included angle between the two straight portions is greater than the angle of the desired component; Step b, treating the fiber reinforcement material according to the composite material curing and molding process; Step c, laying polytetrafluoroethylene cloth on the composite material mold, laying the required materials on the polytetrafluoroethylene cloth, sealing the outermost layer with high-temperature tape and vacuum bag, and evacuating; Step d: adjusting the angles of the two straight portions of the composite material mold by the angle adjustment structure so that the included angle between the two straight portions is equal to the angle of the desired component, and during the adjustment process, wrinkles are gradually eliminated; When vacuuming, the composite material will produce wrinkles. The user adjusts the angle between the two straight parts through the angle adjustment structure to change the bending radius of the bending part. In the process of changing the bending radius of the bending part, the wrinkles will gradually disappear. Step e: After removing wrinkles, continue to perform subsequent steps according to the process of composite material curing and molding; The composite material curing molding process is vacuum assisted resin infusion molding; The step b comprises: cutting a high-performance fiber cloth, placing the fiber cloth in an oven after cutting, and drying the fiber cloth in the oven at high temperature; the materials required in the step c include a guide mesh, a release cloth, and a porous isolation film; the step e comprises: turning on a vacuum pump, connecting one end of an air tube to the vacuum pump, placing the other end in resin, and using vacuum negative pressure to draw the resin into the device; after the resin in the device is evenly infiltrated and there are no bubbles in the resin drawn out of the transparent air tube connected to the vacuum pump, closing the glue inlet; Step f, setting a temperature curve or a temperature and pressure curve in the system, and then performing curing and molding according to the process; Step g: After curing is completed and the temperature has cooled, the sample is taken out and demoulded.

2. The composite material forming method according to claim 1, characterized in that: The angle adjustment structure includes an adjusting drive member and two driving threaded rods, and the two driving threaded rods are respectively connected to the two straight parts; one end of the driving threaded rod is threadedly connected to the adjusting drive member, and the other end is connected to the straight part through an elastic structure or a movably connected; when the adjusting drive member rotates, the two driving threaded rods are driven to move closer to or away from each other, thereby driving one end of the two straight parts to move closer to or away from each other.

3. The composite material forming method according to claim 2, characterized in that: The adjusting drive member is provided with a rotation auxiliary groove for a tool to pass through.

4. The composite material forming method according to claim 1, wherein: A plurality of reinforcing ribs are fixed to the straight portion.

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