Manufacturing method and equipment for a continuous fiber reinforced structural member

Abstract

This application relates to the technical field of structural component injection molding, and particularly to a manufacturing method and equipment for continuously fiber-reinforced structural components, aiming to solve the problem that it is difficult to simultaneously meet the requirements of lightweight and high strength in the preparation of structural components in the prior art. It includes: heating a thermoplastic composite sheet and placing it in a mold; designing an original material formula, preparing materials according to the formula, and mixing the materials into a uniform melt; controlling the conveying and injection molding of the melt material through a reversing valve; associating manufacturing data with the product. The equipment includes an extrusion and mixing mechanism responsible for the melting, plasticizing, and mixing of each material in the original material formula, an injection molding mechanism for realizing the injection of the melt material, a mold clamping unit of an injection molding machine for completing the forming and curing, a control system for coordinating the entire process, and an information traceability mechanism for ensuring the traceability of the product. This solution is applicable to the manufacturing of functional components with extremely high requirements for performance and safety in the aerospace and automotive industries.

Description

Technical Field

[0001] This application relates to the technical field of structural component injection molding, and particularly relates to a manufacturing method and equipment for continuously fiber-reinforced structural components. Background Art

[0002] Low-altitude economy covers multiple fields such as low-altitude manufacturing, low-altitude flight, low-altitude support, and comprehensive services. Among them, low-altitude manufacturing is particularly crucial, which includes the R & D and production of aircraft and their components. In this field, unprecedentedly strict requirements are put forward for the lightweight, stability, and traceability of components. Especially for new types of aircraft such as electric vertical takeoff and landing aircraft (eVTOL) and unmanned flying cars, the demand for the lightweight, strength, and reliability of components is increasing day by day.

[0003] The structural components of low-altitude aircraft undertake the important task of supporting and connecting other components. These structural components must have sufficient strength and stiffness, and at the same time meet the requirements of lightweight to improve the overall performance and endurance of the aircraft. Although traditional metal materials have high strength, due to their large weight, it is difficult to meet the lightweight requirements. Therefore, composite materials and high-performance plastics have gradually become the preferred materials for manufacturing the structural components of low-altitude aircraft.

[0004] The mixing and injection molding technology can mainly carry out formulation design and process high-performance and high-fill materials. It melts and mixes various materials through a twin-screw extrusion mixing system to form a uniform melt, and prepares the required components by introducing a thermoplastic composite sheet processing unit and process and combining with the injection molding process. This technology can ensure that the materials are locally strengthened while having consistent performance, which is crucial for manufacturing high-performance plastic components.

[0005] However, the existing mixing and injection molding technology may not fully take into account the dual requirements of lightweight and high strength when applied to the manufacturing of low-altitude aircraft structural components, and the product quality of aircraft structural components cannot be guaranteed during the production process, which limits its application in the manufacturing of high-performance aircraft components. In addition, the existing technology also has deficiencies in the control of the thermal history of material processing, the introduction and retention of continuous fibers, automated control, and product traceability. Summary of the Invention

[0006] Low-altitude aircraft, such as electric vertical takeoff and landing aircraft (eVTOL) and unmanned flying cars, pose extremely high requirements for the lightweight, high strength, heat resistance, corrosion resistance, and impact resistance of structural components. The first aspect of this application provides a manufacturing method for continuous fiber-reinforced structural components. The structural components prepared by this method can not only effectively balance the lightweight and high-strength requirements of structural components but also significantly improve the heat resistance, corrosion resistance, and impact resistance of the materials, thus ensuring that the structural components exhibit excellent performance in complex working environments. The method specifically includes the following steps:

[0007] Preheat the thermoplastic composite sheet.

[0008] Design the original material formula, and feed each component in the original material formula into an extruder in proportion for mixing to obtain a melt material.

[0009] Combine the preheated thermoplastic composite sheet with the melt material through injection molding to obtain a structural component.

[0010] The control system collects the manufacturing data of the structural component and associates the manufacturing data with the structural component.

[0011] Among them, the original material formula includes fibers. The fibers are fed into the extruder by a continuous fiber conveying device. The control system includes a preset proportion of the fibers in the original material formula. The control system interacts with the continuous fiber conveying device to adjust the real-time proportion of the fibers so that the real-time proportion of the fibers is consistent with the preset proportion.

[0012] Preferably, the inlet position of the fibers into the extruder is at the middle position of the extruder and after the middle position along the material flow direction in the extruder.

[0013] Preferably, the control system interacts with the continuous fiber conveying device to adjust the real-time proportion of the fibers so that the real-time proportion of the fibers is consistent with the preset proportion, including:

[0014] The continuous fiber conveying device detects the number of strands and the linear velocity of the fibers and transmits them to the control system.

[0015] The control system includes the Tex value of the fibers and the real-time feeding amount of each component in the original material formula. The control system calculates the mass of the fibers input into the extruder per unit time according to the following formula:

[0016] The actual mass of the fibers input into the extruder per unit time = the number of fiber strands × the linear velocity × the Tex value.

[0017] The control system calculates the real-time proportion of the fibers based on the actual fiber mass input into the extruder per unit time and the real-time delivery amounts of the components in the original material formula, and compares it with the preset proportion of the fibers;

[0018] In the case where there is a deviation in the comparison result, at least one of the following methods is adopted for adjustment to eliminate the deviation:

[0019] Adjust the number of fiber strands and adjust the rotational speed of the extruder screw at a minimum speed of 1 revolution per second.

[0020] Preferably, the preheated thermoplastic composite sheet is combined with the melt material through injection molding to obtain a structural member, including: a material storage stage and an injection and holding pressure stage.

[0021] The material storage stage includes: conveying the melt material in the extruder to the injection device, and also conveying the melt material in the melt buffer device to the injection device when there is melt material in the melt buffer device;

[0022] The injection and holding pressure stage includes: injecting the melt material in the injection device into the mold cavity where the thermoplastic composite sheet is located, so that the thermoplastic composite sheet is combined with the melt material to obtain a structural member; meanwhile, the extruder is communicated with the melt buffer device, and the melt material in the extruder enters the melt buffer device.

[0023] Preferably, during the material storage stage, the temperature in the injection device is 210°C to 400°C, the back pressure is 10 bar to 200 bar, and the maximum material storage position is 5 times the diameter of the injection piston;

[0024] Preferably, during the injection and holding pressure stage, the injection speed of the injection device is 20 mm / s to the upper limit of the injection speed of the injection device, preferably 20 mm / s to 150 mm / s, the holding pressure during the injection process is 50 bar to 800 bar, and the time is 0 s to 1000 s, preferably 2.5 s to 3.5 s;

[0025] Preferably, during the injection and holding pressure stage, the temperature of the melt buffer device is 210°C to 400°C;

[0026] Preferably, the material storage stage and the injection and holding pressure stage can be cycled to achieve continuous production of the structural member.

[0027] Preferably, design the original material formula, and send the components in the original material formula into the extruder in proportion for mixing to obtain the melt material, including:

[0028] Feed the resin matrix, mineral powder, and fiber into an extruder in a ratio of (50 - 60):(1 - 10):(30 - 60) for mixing to obtain a melt material;

[0029] Preferably, the ratio of the resin matrix, mineral powder, and fiber is 55:5:40;

[0030] Preferably, the resin matrix is made of polypropylene resin;

[0031] Preferably, the fiber is a continuous fiber, and the Tex value of the continuous fiber is set to be 2300 g / km to 2500 g / km;

[0032] Preferably, the extruder is specifically a twin-screw extruder, the internal temperature of the extruder is 210°C to 400°C, the production rate is 110 kg / h to 120 kg / h, and the screw speed is 180 rpm to 200 rpm.

[0033] Preferably, the preheating treatment of the thermoplastic composite sheet includes:

[0034] Heat the thermoplastic composite sheet and then place it in a mold, and the heating temperature is 210°C to 230°C;

[0035] Preferably, the thermoplastic composite sheet is made of a fiber-reinforced resin material, preferably one of a 30% to 60% continuous fiber-reinforced polypropylene resin material, carbon fiber-reinforced polypropylene, and nylon.

[0036] Preferably, collecting the manufacturing data of the structural member and associating it with the structural member includes:

[0037] Collect the manufacturing data of the structural member, encapsulate the received manufacturing data into an information code, and set the information code on the structural member;

[0038] Preferably, the manufacturing data includes at least one of the heating temperature of the thermoplastic composite sheet, material mixing parameters, forming parameters, and processor information.

[0039] The second aspect of the present application provides a manufacturing device for a continuous fiber-reinforced structural member to implement the above method. The device includes:

[0040] An extrusion and mixing mechanism, including an extruder, a loss-in-weight metering feeding device, and a continuous fiber conveying device. The loss-in-weight metering feeding device is connected to the extruder and is used to add raw materials and measure the added amount of raw materials; the continuous fiber conveying device is connected to the extruder and is used to convey fibers and real-time collect fiber conveying amount data and feedback it to the control system;

[0041] Preferably, the inlet position of the fiber into the extruder is at the middle position of the extruder and after the middle position along the material flow direction in the extruder;

[0042] An injection molding mechanism, including an injection device, a melt buffer device, a reversing valve, and a locking nozzle, the extruder, the injection device, the melt buffer device, and the locking nozzle are connected through the reversing valve;

[0043] An injection molding machine clamping unit, connected to the injection molding mechanism, for molding the structural member;

[0044] A control system, connected to the extrusion and mixing mechanism, the injection molding mechanism, and the injection molding machine clamping unit, for realizing the automatic control and coordination of the manufacturing process of the structural member and collecting the manufacturing data of the structural member; and

[0045] An information traceability mechanism, connected to the control system, for receiving the manufacturing data collected by the control system and associating the manufacturing data with the structural member.

[0046] Preferably, the continuous fiber conveying device includes a continuous fiber conveying rack, a continuous fiber conveying roller sensor, and a continuous fiber conveying pipe. The fiber inlet ends of the continuous fiber conveying roller sensor and the continuous fiber conveying pipe are both arranged on the continuous fiber conveying rack. A fiber roll is placed on the continuous fiber conveying rack. The fiber enters the continuous fiber conveying pipe through the continuous fiber conveying roller sensor, and the fiber output end of the continuous fiber conveying pipe is connected to the extruder;

[0047] Preferably, the injection molding machine clamping unit includes an equipment bed body, a mold, a manipulator, and a temperature control device. The mold, the manipulator, and the temperature control device are all arranged on the equipment bed body, and the mold is connected to the locking nozzle.

[0048] Preferably, the information traceability mechanism includes a data storage unit, an information encapsulation unit, and an information code generation device. The data storage unit is connected to the control system to receive and store the manufacturing data of the structural member to be associated; the information encapsulation unit is connected to the data storage unit for converting the manufacturing data of the structural member into an information code suitable for printing or display; the information code generation device is connected to the information encapsulation unit for generating a physical two-dimensional code label device.

[0049] One or more of the above solutions of the present application have at least the following beneficial effects:

[0050] First, the technical solution of this application uses a resin material reinforced with continuous fibers for injection molding, which not only takes into account the dual goals of mechanical properties and lightweight of low-altitude aircraft structural parts, but also improves the temperature resistance, corrosion resistance, especially the impact resistance of the material. This enables the product to exhibit excellent performance in complex working environments. Moreover, in this application, continuous fibers are conveyed into the twin-screw extruder through a continuous fiber conveying device. Through the interaction between the continuous fiber conveying roller sensor and the control system, the fiber conveying amount can be adjusted in a timely manner and controlled at the optimal ratio, further improving the quality of the final product. In addition, the integrated design of the continuously switched directional valve and the extruder-injection device enables continuous production, reduces the production cycle, and improves production efficiency. Strictly controlling the key parameters in the mixing, injection, and molding processes, such as temperature, pressure, time, etc., ensures that each step is in the best working state, thereby improving the molding accuracy and consistency. This method is particularly suitable for the manufacturing of aerospace or automotive industrial parts that require high mechanical strength, lightweight, and processing stability characteristics and consistency.

[0051] Second, this technical solution integrates an efficient extrusion and mixing mechanism, an accurate injection molding mechanism, a stable injection molding machine clamping unit, and an advanced information traceability system. Continuous glass fibers are added at the downstream opening of the twin-screw extruder, and through the design of the screw elements, the processing and dispersion of the fibers are completed under lower shear forces and fully melted and mixed with other material components, ensuring the effective retention length of the continuous fibers and improving the overall performance of the composite material. At the same time, by using thermoplastic organic sheets in combination, local effective strengthening of the product is achieved, meeting the strict requirements of structural parts for mechanical properties. This integrated design allows the entire manufacturing process to be completed in one step through injection molding, greatly improving the design freedom of the product and the ability to achieve complex shapes.

[0052] Third, the information traceability mechanism included in this technical solution enhances the transparency of the product and provides strong support for maintenance and quality assurance. The control system collects key data during the manufacturing process in real time, including the heating temperature of thermoplastic composite sheets, material mixing parameters, molding parameters, etc., and encapsulates this information into information codes (such as QR codes) and attaches them to each finished product. Scanning the information code can view the detailed production process records, ensuring the controllability and traceability of product quality. This approach avoids product quality problems and is also convenient for later tracking and management.

[0053] In addition, the device can flexibly configure the working parameters of each component according to specific production requirements to meet the processing needs of different material formulations and also meet diverse product manufacturing requirements, especially for low-altitude aircraft structural parts that require high strength and lightweight characteristics. Overall, this technical solution greatly improves production efficiency and product quality, reduces energy consumption and costs, and provides a new solution for the manufacturing of high-performance aircraft parts. Brief Description of the Drawings

[0054] The drawings are used to provide further understanding of the present application and form a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation to the present application. In the drawings:

[0055] Figure 1 is a schematic diagram of the steps of a method for manufacturing a continuous fiber reinforced structural member according to an embodiment of the present application;

[0056] Figure 2 is a schematic diagram of the structure of a manufacturing apparatus for a continuous fiber reinforced structural member according to an embodiment of the present application;

[0057] Figure 3 is a schematic diagram of the structure of the extrusion and mixing mechanism and the injection molding mechanism of a manufacturing apparatus for a continuous fiber reinforced structural member according to an embodiment of the present application;

[0058] Figure 4 is a schematic diagram of the structure at the connection between the extrusion and mixing mechanism and the injection molding mechanism of a manufacturing apparatus for a continuous fiber reinforced structural member according to an embodiment of the present application;

[0059] Figure 5 is a schematic diagram of the structure at the connection between the continuous fiber delivery pipe and the extruder of a manufacturing apparatus for a continuous fiber reinforced structural member according to an embodiment of the present application;

[0060] Figure 6 is a schematic diagram of the structure of the continuous fiber delivery device of a manufacturing apparatus for a continuous fiber reinforced structural member according to an embodiment of the present application;

[0061] Figure 7 is a schematic diagram of the structure of the continuous fiber delivery roller sensor of a manufacturing apparatus for a continuous fiber reinforced structural member according to an embodiment of the present application;

[0062] Figure 8 is a schematic diagram of the report situation of information tracing of a product by the information tracing mechanism of a manufacturing apparatus for a continuous fiber reinforced structural member according to an embodiment of the present application.

[0063] Reference Numerals:

[0064] 1. Extrusion and mixing mechanism; 11. Extruder; 12. Loss-in-weight metering feeder; 13. Continuous fiber delivery device; 131. Continuous fiber delivery rack; 132. Continuous fiber delivery roller sensor; 133. Continuous fiber delivery pipe;

[0065] 2. Injection molding mechanism; 21. Injection device; 22. Melt buffer device; 23. Directional valve; 24. Locking nozzle;

[0066] 3. Injection molding machine clamping unit; 31. Equipment bed; 32. Mold; 33. Manipulator; 34. Temperature control device;

[0067] 4. Information traceability mechanism; 41. Information code generation device. Detailed implementation manners

[0068] The embodiments of the present application will be described in detail below. The examples of the embodiments are shown in the drawings. Generally, the components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the present application claimed, but merely represents the selected embodiments of the present application.

[0069] All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without making creative efforts shall fall within the scope of protection of the present application.

[0070] In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present application. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0071] In the description of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "install", "connect", and "couple" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0072] With the booming development of the low-altitude economy, the research and production of new types of aircraft such as electric vertical takeoff and landing aircraft and unmanned flying cars have become crucial. The structural components of these aircraft not only need to have sufficient strength and stiffness to ensure flight safety but also need to meet the requirements of lightweight to improve the overall performance and endurance. Traditional metal materials are difficult to meet the lightweight requirements due to their large weight, while composite materials and high-performance plastics have gradually become the first choice for manufacturing the structural components of low-altitude aircraft. However, there are many deficiencies in the existing mixing and injection molding technologies when applied to the manufacturing of low-altitude aircraft structural components. On the one hand, it is difficult to fully balance the dual requirements of lightweight and high strength, resulting in unstable product quality. On the other hand, there are also obvious defects in the control of the thermal history of material processing, the introduction and retention of continuous fibers, automated control, and product traceability, which limit their application in the manufacturing of high-performance aircraft components. Therefore, it is particularly urgent to develop an injection molding method and equipment that can meet the high-performance requirements of low-altitude aircraft structural components.

[0073] Aiming at the deficiencies of the existing technology in the manufacturing of low-altitude aircraft structural components, this application provides a manufacturing method and equipment for continuously fiber-reinforced structural components, aiming to solve the problems such as the difficulty in balancing the requirements of lightweight and high strength, inaccurate production process control, and poor product traceability in the existing technology. By using a resin material reinforced with continuous fibers for injection molding, this application not only effectively improves the mechanical properties of the structural components but also achieves the lightweight goal and meets the high-performance requirements of low-altitude aircraft for structural components. At the same time, the equipment of this application integrates an efficient extrusion and mixing mechanism, an accurate injection mechanism, a stable injection molding machine clamping unit, and an advanced information traceability system, which can realize the automated control of the production process and the real-time collection of key data, ensuring the stability and traceability of product quality. In addition, by strictly controlling the key parameters such as temperature, pressure, and time in the mixing, injection, and molding processes, this application further improves the molding accuracy and product consistency, providing a reliable solution for the efficient and high-quality production of low-altitude aircraft structural components.

[0074] The following will combine Figure 1 and Figure 8 to clearly and completely describe the technical solutions of this application. Obviously, the described embodiments are part of the embodiments of this application, rather than all of the embodiments.

[0075] Figure 1 is a schematic diagram of the steps of the manufacturing method of the continuously fiber-reinforced structural component provided by the embodiment of this application.

[0076] Please refer to Figure 1 . The first aspect of this application provides a manufacturing method for continuously fiber-reinforced structural components, including the following steps:

[0077] S100. Preheat the thermoplastic composite sheet.

[0078] Before starting the injection molding process, it is first necessary to preheat the thermoplastic composite sheet to ensure that it meets the molding requirements and improves the molding effect and the performance of the final product. The specific operation is as follows:

[0079] After heating the thermoplastic composite sheet to a certain temperature, place it in the injection mold for the subsequent molding steps.

[0080] In some specific examples, the heating process can be carried out using an infrared heating station, a heating furnace or other temperature control devices.

[0081] In some specific examples, the temperature of the heated thermoplastic composite sheet is 180°C to 400°C, for example, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, 300°C, 350°C, 400°C, etc. Through the preheating treatment by heating, the thermoplastic composite sheet can better carry out the injection molding process with the melt material injected subsequently, thereby improving the bonding strength of the final product.

[0082] In some specific examples, the material of the thermoplastic composite sheet can be any resin reinforced with any fiber, such as a continuous fiber reinforced polypropylene resin material, carbon fiber reinforced polypropylene, nylon, etc., preferably a 30% to 60% continuous fiber reinforced polypropylene resin material, such as 30%, 40%, 45%, 50%, 60%, etc., preferably 45%. This material has excellent mechanical properties, improved temperature resistance and impact resistance, and is suitable for manufacturing components with high performance requirements such as low-altitude aircraft.

[0083] S200. Design the original material formula, and feed each component in the original material formula into an extruder according to the ratio for mixing and kneading to obtain a melt material.

[0084] In this step, the original materials of different components are transported to the extruder for mixing and melting to prepare a melt material, ensuring that the final structural part has the required performance during the molding process. This step specifically includes:

[0085] The original material formula of the design is to prepare the original materials according to a certain proportion of the resin matrix, mineral powder, and fiber. The specific proportion can be adjusted according to different products. Preferably, the proportion of the resin matrix, mineral powder, and fiber is (50 - 60):(1 - 10):(30 - 60). For example, the proportion of the resin matrix, mineral powder, and fiber is (50, 52, 54, 56, 58, 60):(1, 2, 4, 6, 8, 10):(30, 32, 35, 37, 39, 41, 43, 45, 50, 55, 60). Preferably, the original materials are prepared according to the proportion that the resin matrix accounts for 55% of the mass of the original materials, the mineral powder accounts for 5% of the mass of the original materials, and the continuous fiber accounts for 40% of the mass of the original materials. The resin matrix and the mineral powder are stored independently in separate hoppers. The addition of the mineral powder can improve the rigidity and wear resistance of the material; the addition of the continuous fiber can enhance the tensile strength, rigidity, fatigue resistance, impact resistance, etc. of the structural member.

[0086] The resin matrix and the mineral powder are accurately fed into the extruder through a loss-in-weight metering feeding device for mixing. At the same time, the continuous fiber is fed into the extruder through a continuous fiber conveying device to ensure that the continuous fiber is fully mixed with the resin matrix and the mineral powder. The input amount of the continuous fiber can be calculated in real time, and by means of fine-tuning the screw speed of the extruder or adjusting the number of fibers, etc., the proportion of the input amount of the continuous fiber in the material is within the set range.

[0087] The inlet position of the fiber entering the extruder is at the middle position of the extruder and after the middle position along the material flow direction in the extruder. There will be a strong shear force at the front section screw of the extruder, which is likely to cause the fiber to be over-sheared and damaged. Setting the fiber inlet at the middle position and after can avoid the fiber being affected by high-intensity shear force when entering the extruder, thus maintaining the integrity and length of the fiber, and further improving the mechanical properties of the composite material, such as tensile strength, rigidity, and fatigue resistance, etc.

[0088] In some specific examples, the continuous fiber can be continuous glass fiber, continuous carbon fiber, continuous aramid fiber, etc.

[0089] Finally, after the extruder processes the above original materials, a uniform melt material is obtained and enters the next forming process.

[0090] In this step, the final product is formed directly by using a specially designed formula, omitting the procurement of commercial plastic particles. This not only simplifies the production process, but also effectively reduces the manufacturing cost of the product. The introduction of continuous fibers significantly increases the effective retention length of the fibers in the resin matrix. Compared with the use of chopped fibers, continuous fibers can form a more complete network structure and skeleton support in the resin matrix, thereby greatly improving the ability of the reinforced material to absorb energy and significantly enhancing the overall strength of the material. This step can ensure that the final structural parts have better mechanical properties and higher reliability when subjected to external forces.

[0091] In some specific examples, the resin matrix is ​​usually made of polypropylene resin, which has good corrosion resistance, thermal stability and molding performance.

[0092] In some specific examples, the continuous fiber is selected from continuous fibers with a Tex value of 1200 g / km to 2500 g / km, such as 1200 g / km, 1500 g / km, 1800 g / km, 2000 g / km, 2100 g / km, 2200 g / km, 2300 g / km, 2400 g / km, 2500 g / km, etc., preferably 1200 g / km or 2400 g / km. "Tex value" is a unit used in the textile industry to indicate the thickness of yarn or fiber, defined as the weight of fiber in grams per 1000 meters in length. Using continuous fibers with higher Tex values ​​can help achieve better mechanical properties while reducing the risk of fiber breakage, thereby ensuring the quality and reliability of the finished product.

[0093] In some specific examples, the extruder can be a twin-screw extruder. The twin-screw extrusion mixing system is responsible for efficiently melt-mixing and dispersing the raw materials (such as resin matrix, mineral powder and continuous fiber) to ensure uniform distribution of each component. In this process, the melt is directly transported to the piston of the subsequent injection device. Compared with the traditional method of injection molding using commercial plastic particles, this method significantly reduces the thermal history of material processing. By reducing the number of heat treatments, the performance degradation of the material during the processing process is effectively reduced, and the original properties of the material are maintained.

[0094] In some specific examples, the temperature of the twin-screw extruder is set to 210°C to 400°C, for example, 210°C, 220°C, 250°C, 280°C, 300°C, 320°C, 340°C, 380°C, 400°C, etc., preferably 240°C, to ensure that the resin matrix, mineral powder and continuous fiber can be fully melted and evenly mixed during the extrusion process.

[0095] In some specific examples, the output of the twin-screw extruder is set to 110kg / h to 120kg / h, for example, 110kg / h, 111kg / h, 112kg / h, 113kg / h, 114kg / h, 115kg / h, 116kg / h, 117kg / h, 118kg / h, 119kg / h, 120kg / h, etc., preferably 114kg / h, and the screw speed is set to 180rpm to 200rpm, for example, 180rpm, 185rpm, 188rpm, 189rpm, 190rpm, 195rpm, 200rpm, etc., preferably 189rpm, to meet the needs of large-scale production and maintain a stable mixing effect.

[0096] S300, combining the preheated thermoplastic composite material sheet with the melt material through injection molding to obtain a structural part.

[0097] The melt material is transported to the injection mold where the preheated thermoplastic composite material sheet is located, and the molding operation is performed to produce the target structural part. The specific operations of this step include:

[0098] S310, adjusting the reversing valve to the first state and entering the material storage stage.

[0099] The material storage stage is to transport the molten material in the extruder to the injection device. In the case where the melt buffer device contains molten material, the molten material in the melt buffer device is also transported to the injection device.

[0100] The reversing valve in the first state enables the extruder and the melt buffer device to be connected to the injection device but not to the injection mold.

[0101] In some specific examples, the extruder specifically uses a twin-screw extruder, which can efficiently melt the molten material completely and evenly mix it, and therefore the screw used for plasticization in the injection device can be replaced by a piston. This design not only simplifies the structure of the injection unit equipment and reduces unnecessary parts, but also greatly increases its effective utilization rate compared to traditional screw injection units. It also significantly reduces the effect of the melt being sheared by the screw again, thereby avoiding the loss of material properties. More importantly, it effectively protects the retained length of the continuous fiber, prevents it from being shortened due to additional shear force, and ensures the mechanical strength of the composite material.

[0102] In some specific examples, the temperature in the injection device is set to 210°C to 400°C, for example, 210°C, 220°C, 250°C, 280°C, 300°C, 320°C, 340°C, 380°C, 400°C, etc., preferably 245°C. This temperature can ensure the fluidity of the molten material during the injection process.

[0103] In some specific examples, the back pressure of the injection device is set to be from 10 bar to 200 bar, for example, 10 bar, 20 bar, 30 bar, 40 bar, 50 bar, 100 bar, 150 bar, 200 bar, etc., preferably 45 bar. The back pressure is the backward pressure borne by the piston or screw in the injection device. The function of the back pressure is to ensure that the melt can be fully compacted, remove air bubbles, increase the melt density, and ensure uniform mixing of the materials.

[0104] In some specific examples, the material storage position of the injection device is set to be 5 times the diameter of the injection piston. The preferred material storage position is from 250 mm to 300 mm, for example, 250 mm, 260 mm, 270 mm, 280 mm, 290 mm, 300 mm, etc., more preferably 280 mm. This is the setting of the position of the piston or screw in the injection device, that is, during the material storage stage, the piston or screw in the injection device retreats to a distance of 250 mm to 300 mm from the injection end of the injection device.

[0105] In some specific examples, if injection pressure holding has been carried out before this stage, then this stage is carried out synchronously with the cooling stage in the mold.

[0106] S320. Adjust the reversing valve to the second state and enter the injection pressure holding stage.

[0107] During the injection pressure holding stage, the injection device is connected to the locking nozzle, so that the melt material is injected from the injection device into the injection mold and combined with the thermoplastic composite sheet by injection molding, and then pressure holding is carried out. At the same time, the injection device is disconnected from the extruder and the melt buffer device, while the extruder is connected to the melt buffer device, and the melt material in the extruder enters the melt buffer device, and the piston of the melt buffer moves upward to prepare for the injection stage.

[0108] In some specific examples, the injection device injects the melt material into the injection mold where the preheated thermoplastic composite sheet is located at a speed of 20 mm / s - 150 mm / s through the locking nozzle. For example, the injection speed can be 20 mm / s, 30 mm / s, 50 mm / s, 80 mm / s, 100 mm / s, 120 mm / s, 150 mm / s, etc., and the preferred injection speed is 65 mm / s. By operating in this way, it can be ensured that the melt material can quickly and evenly fill the entire mold cavity and tightly combine with the preheated thermoplastic composite sheet. The selection of the injection speed is crucial for ensuring that the melt can quickly and evenly fill the entire mold cavity. If the injection speed is too slow, it may cause the melt to cool too quickly and unable to completely fill the mold cavity; if it is too fast, it may generate too much shear heat or cause the gas in the mold cavity to be unable to be discharged in time, forming defects such as bubbles or shrinkage cavities.

[0109] In some specific examples, during the injection process of the melt material, a pressure holding program is carried out synchronously. The pressure for pressure holding can be adjusted according to the actual products to be produced, and can be above 50 - 1000 bar. The time for pressure holding can also be adjusted according to the actual products, and can be above 0 s - 1000 s. Preferably, the range is 50 bar to 800 bar, such as 50 bar, 100 bar, 150 bar, 200 bar, 300 bar, 400 bar, 500 bar, 600 bar, 700 bar, 800 bar, etc. More preferably, it is 280 bar to 320 bar. The injection time can be determined according to the product requirements, and can be 0 s - 1000 s, such as 1 s, 100 s, 500 s, 1000 s, etc. Preferably, it is 2.5 s to 3.5 s, such as 2.5 s, 2.6 s, 2.7 s, 2.8 s, 2.9 s, 3.0 s, 3.1 s, 3.2 s, 3.3 s, 3.4 s, 3.5 s, etc. When producing large products, the melt material can be injected at a pressure of 500 bar for 5 seconds. The main purpose of pressure holding is to ensure the density and flatness of the melt in the mold cavity, and prevent product defects caused by cooling shrinkage. Appropriate pressure holding can improve the quality and dimensional accuracy of the finished product, which is particularly important for large or complex-shaped parts.

[0110] In some specific examples, the melt buffer device maintains a temperature of 210°C to 400°C throughout the process. For example, 210°C, 220°C, 250°C, 280°C, 300°C, 320°C, 340°C, 380°C, 400°C, etc. Preferably, it is 240°C. The temperature of the melt buffer device is close to or the same as the temperature of the extruder, ensuring that the melt material does not solidify due to temperature drop during buffering. At the same time, it receives fresh melt material from the extruder and prepares for the next injection.

[0111] By controlling the directional control valve to alternate between the first state and the second state, and repeatedly carrying out material storage and injection pressure holding, the continuous and efficient preparation of structural parts is achieved. This dynamic switching mechanism ensures that a series of operations such as the transportation, injection, pressure holding, and cooling of the melt material can be accurately completed within each cycle period.

[0112] This continuous production mode not only improves production efficiency, but also reduces the equipment downtime, and lowers energy consumption and costs.

[0113] The above steps achieve the integrated operation of melting, mixing, and injection of the material formula, greatly shortening the heat history of material processing and maximizing the preservation of the original properties of the material. This not only improves production efficiency, but also ensures the stability and reliability of product quality.

[0114] S400. Collect the manufacturing data of the structural parts and associate it with the structural parts.

[0115] To ensure product quality and facilitate traceability, an information management system is adopted to monitor the production process, and relevant data is associated with the structural components. The specific operations are as follows:

[0116] The control system collects key data during the manufacturing process in real time, including the heating temperature of thermoplastic composite sheets, material mixing parameters, molding parameters, processor information, etc.; the collected data is transmitted to the information traceability agency, which encapsulates the data to generate an information code (such as a QR code).

[0117] The information code is attached or engraved on each structural component as the unique identifier of the product. Through the information code, the production batch, manufacturing process, and relevant parameters of the product can be traced, thus ensuring the controllability and traceability of product quality.

[0118] The manufacturing method of the continuous fiber-reinforced structural component provided in the above embodiments of the present application uses injection molding with a continuous fiber-reinforced resin material, which not only improves the mechanical properties of the structural components of low-altitude aircraft, but also increases the high-temperature resistance, corrosion resistance, and impact resistance of the material, and can exhibit excellent performance in complex working environments. By adopting an integrated design of a continuously switched directional valve and an extruder-injection device, this method can achieve continuous production, reduce the production cycle, and improve production efficiency. Through strict manufacturing process control and real-time data collection, this method can ensure that the products of each production batch meet the quality standards and have high traceability, avoiding product quality problems. Precisely control the key parameters in the mixing, injection, and molding processes, such as temperature, pressure, time, etc., to ensure that each step is in the best working state, thereby improving the molding accuracy and consistency.

[0119] When manufacturing the structural components of low-altitude aircraft, the manufacturing method of the continuous fiber-reinforced structural component provided in the above embodiments of the present application uses the combination of a twin-screw extrusion mixing system and an injection molding system, which not only improves the overall performance of the material, but also realizes the local effective strengthening of the product by using thermoplastic organic sheets in cooperation. This method can provide additional strength support at key positions to meet the strict requirements of the structural components for mechanical properties. In addition, this integrated design allows the entire manufacturing process to be completed in one step by injection molding, greatly improving the design freedom of the product and the ability to realize complex shapes. This is an effective means for manufacturing and molding plastic parts with extreme lightweight performance and high mechanical strength requirements. For example, when manufacturing the cabin ceiling shell of an electric vertical takeoff and landing aircraft (eVTOL), this method can ensure that the 45% continuous fiber-reinforced polypropylene resin material used maintains the best performance during the molding process, thus providing the required high strength and lightweight characteristics.

[0120] For applications that require high strength, high temperature resistance, and good toughness, such as in the aerospace or automotive industries, this method is particularly applicable. It can ensure the uniform distribution of continuous fibers and other additives throughout the product, thereby achieving excellent mechanical properties and reliability.

[0121] The following will, in conjunction with Figures 2 to 7 detail the manufacturing equipment for continuous fiber reinforced structural components provided by this application. It should be understood that this equipment is used to implement the steps in the above method embodiments, that is, the descriptions of the equipment embodiments and the method embodiments correspond to each other. Therefore, the parts not detailed in the two types of embodiments can be referred to each other.

[0122] Figure 2 is a schematic structural diagram of the manufacturing equipment for continuous fiber reinforced structural components provided by an embodiment of this application, Figure 3 is a schematic structural diagram of the extrusion and mixing mechanism and the injection molding mechanism of the manufacturing equipment for continuous fiber reinforced structural components provided by an embodiment of this application, Figure 4 is a schematic structural diagram of the connection part between the extrusion and mixing mechanism and the injection molding mechanism of the manufacturing equipment for continuous fiber reinforced structural components provided by an embodiment of this application; Figure 5 is a schematic structural diagram of the connection part between the continuous fiber conveying pipe and the extruder of the manufacturing equipment for continuous fiber reinforced structural components provided by an embodiment of this application; Figure 6 is a schematic structural diagram of the continuous fiber conveying device of the manufacturing equipment for continuous fiber reinforced structural components provided by an embodiment of this application; Figure 7 is a schematic structural diagram of the continuous fiber conveying roller sensor of the manufacturing equipment for continuous fiber reinforced structural components provided by an embodiment of this application.

[0123] Referring to Figures 2 to 7 , a second aspect of this application provides a manufacturing equipment for continuous fiber reinforced structural components. This equipment integrates functions of extrusion and mixing, injection molding, forming, and information traceability, aiming to achieve efficient and high-quality production of composite material structural components. Specifically, it includes: an extrusion and mixing mechanism 1, an injection molding mechanism 2, an injection molding machine clamping unit 3, a control system, and an information traceability mechanism 4.

[0124] The extrusion and mixing mechanism 1 includes an extruder 11, a loss-in-weight metering feeder 12, and a continuous fiber conveying device 13. The loss-in-weight metering feeder 12 is connected to the extruder 11 and is used to add raw materials and measure the addition amount of raw materials; the continuous fiber conveying device 13 is connected to the extruder 11 and is used to input continuous fibers and measure. The inlet position of the fiber into the extruder is at the middle position of the extruder and after the middle position along the material flow direction in the extruder. Preferably, the inlet position of the fiber into the extruder is between the 1 / 2 position and the 1 / 3 position of the length of the extruder along the material flow direction.

[0125] The extruder 11 is responsible for melting and mixing raw materials (such as polypropylene resin matrix and mineral powder) with continuous fibers to form a uniform melt material.

[0126] In some specific examples, the extruder 11 adopts a twin-screw extruder. Continuous glass fibers are added at the downstream opening of the twin-screw extruder, and through the design of screw elements, the processing and dispersion of the fibers are completed under lower shear force, and are completely melted and mixed with other material components, ensuring the effective retention length of the continuous fibers and improving the overall performance of the composite material.

[0127] The loss-in-weight metering feeding device 12 is arranged on the extruder 11 and is used to accurately add and measure the amount of raw materials. For example, in a specific embodiment, after the original material formula is designed, the loss-in-weight metering feeding device 12 can set the input amount of each component according to the proportion of each component in the original material formula, so as to feed each component in the original material formula into the extruder for mixing in proportion. Such a setting can ensure the accuracy of the formula ratio and avoid product defects caused by inaccurate raw material ratio or uneven dispersion.

[0128] The continuous fiber conveying device 13 is also connected to the extruder 11 and is responsible for inputting and measuring continuous fibers. This device can cooperate with the control system and the extruder to jointly realize the closed-loop control of the input amount of continuous fibers, that is, automatically adjust the input rate of continuous fibers according to the set parameters to ensure the uniform distribution of continuous fibers in the melt. For example, for 40% continuous fibers, its input speed can be monitored in real time by a sensor and kept stable through a closed-loop control system.

[0129] The injection molding mechanism 2 includes an injection device 21, a melt buffer device 22, a reversing valve 23, and a locking nozzle 24. The melt buffer device 22 and the injection device 21 are interconnected through the reversing valve 23.

[0130] The injection device 21 can receive the melt material from the extruder 11 and the melt buffer device 22 and inject it into the mold of the injection molding machine clamping unit 3 at a specific speed and pressure. The injection device 21 is equipped with a precise control unit, which can adjust the injection speed (such as 65 mm / s), the holding pressure (such as 300 bar, for 3 seconds), to ensure the quality and repeatability of the melt filling the mold cavity.

[0131] The melt buffer device 22 is located between the extruder 11 and the injection device 21 and is used to receive the melt material in the extruder 11 during the injection holding stage and convey the material inside it to the injection device 21 during the material storage stage, that is, it plays a role in balancing the continuous operation of the extruder and the intermittent injection operation rhythm of the injection device, reducing the fluctuations caused by non-synchronization, so that the extruder 11 and the injection device 21 can work together.

[0132] The reversing valve 23, as a key component connecting the extruder 11, the injection device 21, and the locking nozzle 24, can switch between the first state and the second state, realizing the storage and injection transmission of the melt material.

[0133] The first state is the material storage stage. By adjusting the reversing valve 23, the extruder 11 and the melt buffer device 22 are both connected to the injection device 21, while the injection device 21 cannot be connected to the mold of the injection molding machine clamping unit 3 through the locking nozzle 24.

[0134] The second state is the injection and holding pressure stage. By adjusting the reversing valve 23, the extruder 11 is connected to the melt buffer device 22 and cannot be connected to the injection device 21; and the injection device 21 is connected to the mold of the injection molding machine clamping unit 3 through the locking nozzle.

[0135] The locking nozzle 24 is installed at the front end of the injection device 21, directly contacting the mold 32, and is responsible for introducing the melt material into the mold cavity of the mold of the injection molding machine clamping unit 3 for injection molding of structural parts. The design of the locking nozzle 24 needs to consider factors such as sealing performance, high temperature resistance, and easy cleaning to ensure long-term stable operation.

[0136] The injection molding machine clamping unit 3 is connected to the injection molding mechanism 2 and is used for the molding of structural parts.

[0137] The control system (not shown in the figure) is electrically connected to the extrusion and mixing mechanism 1, the injection molding mechanism 2, and the injection molding machine clamping unit 3 respectively, realizing a high degree of automation of the entire manufacturing process. It not only monitors the working status of each component but also can automatically adjust some parameters according to the preset program to ensure that each step is executed under the optimal conditions.

[0138] The control system is responsible for collecting key manufacturing data, such as the heating temperature of the thermoplastic composite sheet, the material mixing parameters, the molding conditions, etc., and transmitting this information to the information traceability mechanism 4 for subsequent product quality tracking and management.

[0139] As Figure 8 shown, the information traceability mechanism 4 is connected to the control system, receives and processes the manufacturing data, and then packages it into an information code. Each finished product will be accompanied by a unique information code. After scanning, the detailed production process records can be viewed, including but not limited to the organic sheet heating information, injection molding parameters, processor information, etc. This approach not only enhances the transparency of the product but also provides strong support for maintenance and quality assurance.

[0140] In some embodiments, refer to Figure 3 and Figure 6, the continuous fiber conveying device 13 includes a continuous fiber conveying rack 131, a continuous fiber conveying roller sensor 132, and a continuous fiber conveying pipe 133. The fiber inlet ends of the continuous fiber conveying roller sensor 132 and the continuous fiber conveying pipe 133 are arranged on the continuous fiber conveying rack 131. A continuous fiber roll is placed on the continuous fiber conveying rack 131. The continuous fiber passes through the continuous fiber conveying roller sensor 132, enters the continuous fiber conveying pipe 133, and enters the middle or rear section of the twin-screw extruder through the fiber outlet end of the continuous fiber conveying pipe 133, thus avoiding the plasticizing section at the front stage of the twin-screw extruder and screw structures such as kneading blocks or mixing blocks, so as to prevent the continuous fiber from being overly crushed.

[0141] The continuous fiber conveying roller sensor 132 monitors in real time the number of continuous fibers passing through the conveying pipe, the linear velocity (km / h), and the tension, and provides accurate data feedback to the control system. In the control system, the percentage of the mass of continuous aramid fibers required per unit time in the overall material, that is, the preset ratio of continuous fibers, and the Tex value of continuous fibers (such as 2400 g / km) are preset in advance. Then, according to the formula: the mass of fibers input into the twin-screw extruder per unit time = the number of fiber bundle strands × the fiber input linear velocity × the Tex value, the control system can calculate the amount of continuous fibers input into the twin-screw extruder in real time per unit time. At the same time, the control system can monitor in real time the real-time conveying amounts of each component in the original material formula per unit time, and then divide the real-time input fiber mass by the total real-time material conveying amount to obtain the real-time ratio of continuous fiber conveying, and compare it with the preset ratio. If there is a deviation, the control system will control the mass of continuous fibers input into the twin-screw extruder per unit time by fine-tuning the screw rotation speed of the twin-screw extruder (the minimum change in screw rotation speed per second is 1 revolution) or increasing or decreasing the number of continuous fibers, so that it is kept as consistent as possible with the set percentage value.

[0142] In some specific examples, the control system also includes information such as the current equipment productivity (how many kilograms per hour).

[0143] The fiber outlet end of the continuous fiber conveying pipe 133 is connected to the rear section in the extruder 11 to form a closed continuous fiber transmission channel. This ensures that the continuous fiber is not affected by the external environment during the process from the conveyor to the extruder, avoiding interference from pollutants such as dust and moisture, and at the same time preventing the continuous fiber from knotting or tangling.

[0144] The three components in this embodiment together constitute a closed-loop control system (the closed-loop control function can be selectively activated or deactivated), ensuring the precise input of continuous fibers. By optimizing the design and arrangement of each component, the entire conveying system can operate efficiently with minimized shear force, maximizing the retention of the original length of continuous fibers, which is particularly important for enhancing the mechanical properties of composite materials. The precise metering of continuous fibers and the stable conveying process not only improve product quality but also reduce the scrap rate caused by uneven input of continuous fibers, enhancing overall production efficiency and consistency.

[0145] In some specific examples, the number of continuous fibers should be around 8 strands. If the required feed rate of continuous fibers is fixed, when the number of fibers (strands) is less or more, it is necessary to increase or decrease the linear velocity of the continuous fibers, that is, significantly increase or decrease the rotational speed of the screw machine. When the rotational speed of the screw machine is significantly changed, other problems will arise. Therefore, by controlling the number of continuous fiber strands to be around 8, the conveying volume of continuous fibers can be controlled more precisely, thereby preparing better-quality structural parts.

[0146] In some specific examples, the number of continuous fibers is 8 strands, the linear velocity of the continuous fibers measured by the continuous fiber conveying roller sensor 132 is 2.38 km / h, and the Tex value of the continuous fibers is 2400 g / km. At this time, the mass of fibers input into the twin-screw extruder per unit time = number of fibers × fiber input linear velocity × Tex value = 8 × 2.38 km / h × 2400 g / km = 45700 g / h = 45.7 kg / h. The control system will compare this value with the preset required value. At this time, the rotational speed of the screws of the twin-screw extruder is 195 / min. If there is a deviation in the comparison, the control center will further fine-tune the rotational speed of the screws of the twin-screw extruder to make it as close as possible to the set value.

[0147] In some embodiments, refer to Figure 2 , the injection molding machine clamping unit 3 includes an equipment bed 31, a mold 32, a manipulator 33, a temperature control device 34, a fixed template, a moving template, etc.

[0148] The equipment bed 31 serves as a support platform, carrying the mold 32, the manipulator 33, and the temperature control device 34, and providing a stable installation foundation.

[0149] The mold 32 is installed on the equipment bed 31 and is directly connected to the locking nozzle 24, carrying the preheated thermoplastic composite sheet and receiving the melt material from the injection molding mechanism. The mold is a key component that determines the final shape and size of the product. It is internally provided with precise chambers and channels that can precisely control the flow path of the melt, ensuring that every detail meets the design requirements.

[0150] The mold 32 is usually made of high-strength alloy steel and has good thermal conductivity and wear resistance. To improve production efficiency, the mold is also equipped with a quick-change interface for rapid switching between different batches. In addition, heating elements are integrated inside the mold.

[0151] The manipulator 33 can be set on the equipment bed 31 according to actual production needs, near the mold. The manipulator 33 is responsible for automated operations, including placing the cut sheet into the infrared heating station for preheating, hanging the preheated sheet into the mold 32, and taking out the finished product, etc. The design of the manipulator needs to consider flexibility, accuracy, and speed to ensure that each action can be precisely executed.

[0152] The temperature control device 34 can be set on the equipment bed 31 or on the fixed platen according to actual production needs, and is arranged around the mold 32. The temperature control device 34 can preheat the thermoplastic composite sheet as needed, promote good bonding between the melt and the thermoplastic composite sheet, and avoid product defects caused by temperature differences.

[0153] In some specific examples, the temperature control device 34 usually takes the form of an infrared heating station, an electric heating plate, or an induction heater, etc., and has the characteristics of rapid heating, uniform heating, and easy control.

[0154] In some embodiments, the information traceability mechanism 4 includes a data storage unit (not shown in the figure), an information encapsulation unit (not shown in the figure), and an information code generation device 41. The data storage unit is connected to the control system to receive and store the structural part manufacturing data that needs to be associated; the information encapsulation unit is connected to the data storage unit for converting the structural part manufacturing data into an information code suitable for printing or display; the information code generation device 41 is connected to the information encapsulation unit for generating a device for physical two-dimensional code labels as Figure 8 shown.

[0155] The working process of the injection molding equipment for manufacturing low-altitude aircraft structural parts provided in the second aspect of this application is as follows:

[0156] (1) Preheat the thermoplastic composite sheet:

[0157] Preheat the thermoplastic composite sheet through the temperature control device 34, and then put the thermoplastic composite sheet into the mold 32 through the manipulator 33 to prepare for the subsequent molding steps.

[0158] (2) Material mixing:

[0159] Feed the proportional resin matrix and mineral powder into the extruder 11 through the loss-in-weight metering feeding device 12; at the same time, feed the proportional continuous fibers into the extruder 11 through the continuous fiber conveying device 13.

[0160] The extruder 11 melts and kneads the above components at a certain temperature and rotation speed to obtain a uniform melt material.

[0161] (3)Storage and injection of the melt material:

[0162] Adjust the reversing valve 23 to the first state, and the melt material in the extruder 11 is transported to the injection device 21.

[0163] After the storage is completed, adjust the reversing valve 23 to the second state again, so that the injection device 21 injects the melt material into the mold 32 where the pre-heated thermoplastic composite sheet is located through the locking nozzle 24 at a certain injection speed, and holds the pressure to ensure that the melt material is tightly combined with the thermoplastic composite sheet and fills the entire mold cavity.

[0164] During this process, the melt buffer device 22 maintains the same temperature as the injection device 21 (the temperature is set to be the same), and receives fresh melt material from the extruder to prepare for the next storage stage.

[0165] After the injection is completed, adjust the reversing valve 23 to the first state again, transport the melt material in the extruder 11 and the melt buffer device 22 to the injection device 21, and then switch the reversing valve again, so as to continuously prepare the structural parts in a cycle.

[0166] (4)Forming of the structural part:

[0167] After the injection is completed, during the storage stage, the melt material cools and solidifies in the mold 32 to form the final structural part. After the mold is opened, it is taken away by the manipulator 33, and then a new pre-heated thermoplastic composite sheet is placed to wait for the next injection.

[0168] (5)Data collection and information traceability:

[0169] The control system collects key data of the entire manufacturing process, such as the heating temperature of the thermoplastic composite sheet, the material mixing parameters, the forming parameters, etc.

[0170] These data are transmitted to the information traceability mechanism 4, which encapsulates the data into an information code as shown in Figure 8 (for example, a two-dimensional code), and attaches the information code to each finished product to achieve product traceability.

[0171] A manufacturing device for a continuous fiber-reinforced structural member provided in the second aspect of the present application realizes the continuous and efficient preparation of the structural member by quickly alternating between the first state and the second state through a reversing valve, reduces the equipment downtime, and greatly improves the overall working efficiency. The manipulator and the intelligent control system cooperate together to achieve the full-process automation from the preheating treatment of the thermoplastic composite sheet to the taking out of the finished product, reduces the manual intervention, reduces the human errors, and improves the production stability.

[0172] The device can strictly control key process parameters such as injection speed, holding pressure parameters, and temperature of the melt buffer device, ensuring that each production step can be executed under the optimal conditions, thereby significantly improving the quality of the finished product. And a twin-screw extruder is used for material mixing, reducing the risk of the melt being sheared again, protecting the length of the continuous fiber, and improving the mechanical strength and durability of the composite material. The device collects and transmits manufacturing data through the control system, and the information traceability mechanism generates a two-dimensional code containing detailed manufacturing information, which is attached or engraved on each finished product. This approach not only enhances the transparency of the product but also provides strong support for maintenance and quality assurance, facilitating later tracking and management.

[0173] In addition, the device can flexibly configure the working parameters of each component according to specific production requirements, meeting the diverse product manufacturing needs, especially for low-altitude aircraft structural members that require high strength and lightweight characteristics.

[0174] It should be noted that the technical solutions in the various embodiments of the present application can be combined with each other, but the basis for combination is that those skilled in the art can implement it; when the combination of technical solutions conflicts with each other or cannot be implemented, it should be considered that such a combination of technical solutions does not exist, that is, it does not belong to the protection scope of the present application either.

[0175] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present application.

Claims

1. A method for manufacturing a continuous fiber reinforced structural member, characterized in that: The steps include: preheating the thermoplastic composite sheet; Designing a raw material formula, feeding each component in the raw material formula into an extruder according to a proportion for mixing to obtain a melt material; Combining the preheated thermoplastic composite material sheet with the melt material through injection molding to obtain a structural part; The control system collects manufacturing data of the structural component and associates the manufacturing data with the structural component; The extruder is specifically a twin-screw extruder, the original material formula includes fibers, the fibers are fed into the extruder by a continuous fiber conveying device, the control system includes a preset proportion of the fibers in the original material formula, and the control system interacts with the continuous fiber conveying device to adjust the real-time proportion of the fibers so that the real-time proportion of the fibers is consistent with the preset proportion; The control system interacts with the continuous fiber delivery device to adjust the real-time ratio of the fibers so that the real-time ratio of the fibers is consistent with the preset ratio, including: The continuous fiber delivery device detects the number of strands and the linear speed of the fiber and transmits them to the control system; The control system includes the Tex value of the fiber and the real-time delivery amount of each component in the original material formula. The control system calculates the fiber mass input into the extruder per unit time according to the following formula: The actual fiber mass input into the extruder per unit time = number of fiber strands × linear speed × Tex value; The control system calculates the real-time ratio of the fibers according to the actual fiber mass input into the extruder per unit time and the real-time delivery amount of each component in the original material formula, and compares it with the preset ratio of the fibers; If there is a deviation in the comparison result, at least one of the following methods shall be adopted to make adjustments to eliminate the deviation: The fiber strand count was adjusted and the extruder screw speed was adjusted to a minimum of 1 revolution per second.

2. The method for manufacturing a continuous fiber reinforced structural member according to claim 1, characterized in that: The fiber inlet position entering the extruder is at the middle position of the extruder and after the middle position along the material flow direction in the extruder.

3. The method for manufacturing a continuous fiber reinforced structural member according to claim 1, characterized in that: The preheated thermoplastic composite material sheet is combined with the melt material by injection molding to obtain a structural part, including: a material storage stage and an injection pressure holding stage, The material storage stage includes: conveying the molten material in the extruder to the injection device, and in the case where the melt buffer device contains the molten material, conveying the molten material in the melt buffer device to the injection device; The injection and pressure holding stage includes: injecting the molten material in the injection device into the mold cavity where the thermoplastic composite material sheet is located, so that the thermoplastic composite material sheet and the molten material are combined to obtain a structural part; at the same time, the extruder is connected to the melt buffer device, and the molten material in the extruder enters the melt buffer device.

4. The method for manufacturing a continuous fiber reinforced structural member according to claim 3, characterized in that: During the material storage stage, the temperature in the injection device is 210° C. to 400° C., the back pressure is 10 bar to 200 bar, and the maximum material storage position is 5 times the diameter of the injection piston.

5. The method for manufacturing a continuous fiber reinforced structural member according to claim 3, characterized in that: During the injection pressure holding stage, the injection speed of the injection device is from 20 mm / s to the upper limit of the injection speed of the injection device, and the pressure is held at 50 bar to 800 bar during the injection process for a time of 0 s to 1000 s.

6. The method for manufacturing a continuous fiber reinforced structural member according to claim 3, characterized in that: The injection speed of the injection device is 20 mm / s to 150 mm / s.

7. The method for manufacturing a continuous fiber reinforced structural member according to claim 3, characterized in that: The injection process takes 2.5s to 3.5s.

8. The method for manufacturing a continuous fiber reinforced structural member according to claim 3, characterized in that: During the injection and pressure holding stage, the temperature of the melt buffer device is 210°C to 400°C.

9. The method for manufacturing a continuous fiber reinforced structural member according to claim 3, characterized in that: The material storage stage and the injection pressure holding stage can be performed cyclically to achieve continuous production of structural parts.

10. The method for manufacturing a continuous fiber reinforced structural member according to claim 1, characterized in that: Designing an original material formula, feeding each component in the original material formula into an extruder in proportion for mixing to obtain a melt material comprising: The resin matrix, mineral powder and fiber are fed into an extruder in a ratio of (50-60): (1-10): (30-60) for mixing to obtain a molten material.

11. The method for manufacturing a continuous fiber reinforced structural member according to claim 10, characterized in that: The ratio of resin matrix, mineral powder and fiber is 55:5:

40.

12. The method for manufacturing a continuous fiber reinforced structural member according to claim 10, characterized in that: The resin matrix is ​​made of polypropylene resin.

13. The method for manufacturing a continuous fiber reinforced structural member according to claim 10, characterized in that: The fiber is a continuous fiber, and the Tex value of the continuous fiber is set to be 2300 g / km to 2500 g / km.

14. The method for manufacturing a continuous fiber reinforced structural member according to claim 10, characterized in that: The internal temperature of the extruder is 210° C. to 400° C., the output rate is 110 kg / h to 120 kg / h, and the screw speed is 180 rpm to 200 rpm.

15. The method for manufacturing a continuous fiber reinforced structural member according to claim 1, characterized in that: The preheating of the thermoplastic composite sheet includes: The thermoplastic composite sheet is heated and then placed into a mold, and the heating temperature is 210°C to 230°C.

16. The method for manufacturing a continuous fiber reinforced structural member according to claim 15, characterized in that: The thermoplastic composite material sheet adopts a fiber-reinforced resin material.

17. The method for manufacturing a continuous fiber reinforced structural member according to claim 16, characterized in that: The fiber-reinforced resin material used in the thermoplastic composite sheet is one of 30% to 60% continuous fiber-reinforced polypropylene resin material, carbon fiber-reinforced polypropylene, and nylon.

18. The method for manufacturing a continuous fiber reinforced structural member according to claim 1, characterized in that: Collecting the manufacturing data of the structural component and associating it with the structural component includes: The manufacturing data of the structural component is collected, the received manufacturing data is packaged into an information code, and the information code is set on the structural component.

19. The method for manufacturing a continuous fiber reinforced structural member according to claim 18, characterized in that: The manufacturing data includes at least one of the heating temperature of the thermoplastic composite sheet, material mixing parameters, molding parameters, and processor information.

20. A manufacturing device for implementing the method for manufacturing a continuous fiber reinforced structural member according to any one of claims 1 to 19, characterized in that: include: The extrusion mixing mechanism comprises an extruder, a weight-loss metering feeding device and a continuous fiber conveying device, wherein the weight-loss metering feeding device is connected to the extruder and used to add raw materials and measure the amount of raw materials added; the continuous fiber conveying device is connected to the extruder and used to convey fibers and collect fiber conveying amount data in real time and feed it back to the control system; An injection molding mechanism comprises an injection device, a melt buffer device, a reversing valve and a locking nozzle, wherein the extruder, the injection device, the melt buffer device and the locking nozzle are connected via the reversing valve; An injection molding machine clamping unit, connected to the injection molding mechanism, for molding the structural parts; A control system connected to the extrusion mixing mechanism, the injection molding mechanism and the injection molding machine clamping unit, for realizing automatic control and coordination of the structural component manufacturing process and collecting manufacturing data of the structural component; and The information tracing mechanism is connected to the control system and is used to receive the manufacturing data collected by the control system and associate the manufacturing data with the structural component.

21. The manufacturing equipment for continuous fiber reinforced structural parts according to claim 20, characterized in that: The fiber inlet position entering the extruder is at the middle position of the extruder and after the middle position along the material flow direction in the extruder.

22. The manufacturing equipment for continuous fiber reinforced structural parts according to claim 20, characterized in that: The continuous fiber conveying device includes a continuous fiber conveying frame, a continuous fiber conveying roller sensor and a continuous fiber conveying tube. The continuous fiber conveying roller sensor and the fiber entry end of the continuous fiber conveying tube are both arranged on the continuous fiber conveying frame. A fiber roll is placed on the continuous fiber conveying frame. The fiber enters the continuous fiber conveying tube through the continuous fiber conveying roller sensor. The fiber output end of the continuous fiber conveying tube is connected to the extruder.

23. The manufacturing equipment for continuous fiber reinforced structural parts according to claim 20, characterized in that: The injection molding machine clamping unit comprises an equipment bed, a mold, a manipulator and a temperature control device. The mold, the manipulator and the temperature control device are all arranged on the equipment bed, and the mold is connected to the locking nozzle.

24. The manufacturing equipment for continuous fiber reinforced structural parts according to claim 20, characterized in that: The information tracing mechanism includes a data storage unit, an information packaging unit and an information code generating device. The data storage unit is connected to the control system to receive and store the structural component manufacturing data that needs to be associated; the information packaging unit is connected to the data storage unit and is used to convert the structural component manufacturing data into an information code suitable for printing or display; the information code generating device is connected to the information packaging unit and is a device for generating a physical two-dimensional code label.

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