For large-diameter corrugated pipes, the main forming methods include: hydraulic forming, roll forming and mechanical expansion.
Among them, the hydroforming method is a multi-wave synchronous overall forming of the corrugated pipe, which has the characteristics of high forming accuracy and uniform axial forming force;
The roll forming method is through rolling The corrugated pipe is formed by continuous rolling of a single wheel wave by wave. It has the characteristics of local forming process. It is difficult to control the wave pattern consistency and the wave pitch control accuracy is poor;
The mechanical expansion method uses a cone. The molding shaft rotates and feeds to squeeze the split molding die to cause it to expand outwards to achieve bellows forming. It is completed in a single wave by wave continuous expansion method, which has the characteristics of poor wave pitch control accuracy and poor wave size. , especially when the opening and closing positions of the split mold are in the process of external expansion, a straight line segment instead of an arc-shaped wave will be produced.