Manufacture of Special-Shaped Screws via Whirling

Special-shaped screws are widely used in industries. However, the approach to machining special-shaped screws with high working efficiency and high surface quality is still in pursuit. This paper studies the mathematical model of screws with variable leads, diameters and groove depths based on the general model and the formation mechanism of the common screw. After that, by the further study of the mathematical model of special-shaped screws and the cutting principle of whirling, the paper finds the way to calculate the tool path of screws with variable leads, diameters and groove depths which can be used to whirling machines. Ultimately, a actual work piece is successfully machined via whirling in experiment.