Low-frequency torsion shock excitation device for extruding internal threads

The invention discloses a low-frequency torsion shock excitation device for extruding internal threads. The device comprises a thread forming tap (3C) and a main shaft (1A); and the thread forming tap (3C) is mounted in one end of the main shaft (1A). The device is characterized in that the other end of the main shaft (1A) is connected with a rocker arm rocker rod mechanism (2) capable of enabling the main shaft (1A) to generate low-frequency torsion shock excitation; the rocker arm rocker rod mechanism (2) is connected with a driving mechanism; a tension rod (1I) for preventing a conical clamping handle (3A) to fall is mounted in the main shaft (1A); the lower end of the tension rod (1I) is connected with the clamping handle (3A), and the upper end of the tension rod (1I) is mounted in a chuck cage (1K); a three-jaw chuck (1H) is mounted in the chuck cage (1K); one end of the three-jaw chuck (1H) is inserted in a positioning hole of the main shaft (1A); and a tension nut (1J) is screwed at the upper end of t