Springback control method for groove type inner punching die of aluminum alloy automobile covering part

The invention relates to a springback control method for a groove-shaped inner punching die of an aluminum alloy automobile covering part. The springback control method comprises the following steps: S1, filling by adopting a triple-action wedge; s2, constant-load pressing is conducted on the AB section and the BC section of the workpiece (1); s3, a rotary wedge is adopted for pressing the CD section of the workpiece (1), and in the pressing process, a waste outlet space in a waste sliding way base (15) is avoided; s4, carrying out suspension punching on the CD section of the workpiece (1) sleeved by the groove-shaped profiling block (6) through a pressure source at the upper part; and S5, after punching is completed, the BC section and the CD section of the workpiece (1) are subjected to pressure maintaining through a delay nitrogen spring device (10). According to the method, rebound warping of the fillet areas of the side faces and the bottom face of the groove profile is effectively guaranteed, and meanwh