WINDING MANDREL MECHANISM AND WINDING MACHINE

A winding mandrel mechanism and a winding machine are provided. The winding mandrel mechanism includes a winding pin holder, two half winding pin assemblies, and a driving rod. Each half winding assembly includes an outer pin and an inner clip mounted to the winding pin holder and movable along a radial direction of the winding mandrel mechanism. The driving rod is advanced axially, and inner clips are driven by second cam structures to move radially until clamping material to be wound. The winding mandrel mechanism is rotated to wind the clamped material around outer periphery of the winding mandrel mechanism. To adjust a circumference of the winding mandrel mechanism, the driving rod is advanced continuously along the axial direction of the winding mandrel mechanism, and outer pins are driven to move radially away by first cam structures, thereby increasing the circumference of the outer pins.