This invention belongs to the field of composite material processing technology and involves a manufacturing method for a slender carbon fiber composite square tube structure component.
Background Technology:
Carbon fiber composite materials have been widely used in aerospace products due to their advantages of lightweight, high strength, corrosion resistance, easy molding, and aesthetic quality. The structural trend of composite material components tends to be simplified and lightweight. However, under the existing technical conditions, there are significant challenges in composite material molding processes. One such structure is a slender composite tube component (refer to Figure 1). This composite material component is a slender carbon fiber square tube structure component with a uniform thickness around the product and a small internal cavity size. The dimensions are (50 × 60) mm with a length of approximately 1000 mm. The inner and outer surfaces of the slender carbon square tube structure component must be smooth, especially the inner surface, which has subsequent assembly connections. The dimensional requirements for assembly accuracy are high. Since the composite material carbon fiber structure mainly relies on fiber load transfer, the assembly area cannot be polished or modified. The inner surface dimensions in the assembly area require high precision, and the dimensions of the four corner areas (4 r) must meet the size requirements. Therefore, the inner surface of the slender carbon fiber composite square tube structure component must rely on mold forming to ensure that the internal surface dimensions meet the assembly requirements. However, due to the structural design of this component as a square tube structure and the complexity of the existing composite material manufacturing methods, the main complexity lies in the demolding process of the product. To meet the structural requirements, the existing molding methods mainly include the following ways:
1. The use of positive mold molding: The risk of this method is that during the demolding process, due to the small size of the inner cavity and the slender structure of the component, the product and the positive mold fit tightly after being heated and molded at high temperature and pressure. Existing molding methods cannot separate the product from the positive mold, resulting in quality issues related to demolding.
2. The use of negative mold molding: The risk of this method is that while the dimensions of the outer surface can be guaranteed, it cannot meet the requirements for the dimensions of the internal surface and the r-corner area as specified by the product. Therefore, the co-ordination accuracy required for subsequent assembly of the product cannot be guaranteed.
3. The use of elastic mold: Negative and positive molds are used, with the positive mold being replaced by an expandable core mold or an inflatable core mold, which is inflated by an external air source to expand and transmit pressure to the surface of the laminate. The molding risk of this method for the slender carbon fiber composite square tube structure component lies in the high requirements for the inflatable core mold, which needs a separate forming process, resulting in complex production processes and increased production costs.
In this technical background, for such a slender carbon fiber square tube structure component, which requires a simple and lightweight shape, smooth inner and outer surfaces, and internal surface dimensions that meet the requirements of assembly accuracy, breakthroughs must be made on the existing molding processes. This invention utilizes positive mold lamination, uses a uniform pressure plate for the outer surface forming mold, and ensures product demolding with the assistance of demolding auxiliary tooling on the premise of guaranteeing product quality. This technical approach achieves the manufacturing of slender carbon fiber square tube structure components, improves part quality, and ensures dimensional requirements for internal surface assembly accuracy.