Double-sided chamfering fine punching process and device

The invention relates to a double-sided chamfering fine punching process. The process comprises the following steps of S11, pre-punching, specifically, fine punching a pre-punched hole in a workpiece,wherein the hole diameter of the pre-punched hole is larger than the hole diameter of a fine-punched finished product hole; S12, chamfering, specifically, extruding workpiece materials at the edges of the two ends of the pre-punched hole to form chamfers, wherein the pre-punched hole in the extrusion process receives the workpiece material at the chamfers to form a transition hole, and the hole diameter of the transition hole after extrusion is smaller than the hole diameter of the fine-punched finished product hole; and S13, shaping, specifically, fine punching the transition hole to shape to form the fine-punched finished product hole of a predetermined size. The invention also relates to a double-sided chamfering fine punching device. The device comprises a pre-punching punch, extrusion punches and a shaping p