Free-fall impact fatigue testing machine

The invention discloses a free-fall impact fatigue testing machine which comprises a supporting mechanism and a punch hammer mechanism. The punch hammer mechanism is fixed to a ball screw of the supporting mechanism and comprises a round wheel assembly and a punch hammer assembly. According to the testing machine, the round wheel in the round wheel assembly is in periodic contact fit with the L-shaped plate during rotation to drive the punch hammer assembly to ascend and descend freely, and impact fatigue is achieved; by adjusting the mass of weights in the punch hammer assembly and setting the lifting height of the punch hammer mechanism, accurate impact energy quantitative characterization of the free falling body kinetic energy of the punch hammer is achieved. By adjusting the weight mass and the impact stroke, the setting of any impact energy value within the range of hundreds of J is realized, and the precision can reach 0.1 J; and through round wheel driving, the impact frequencyreaches 1 Hz or above. T