Plate shearing machine protection device

A protective device of a plate shearing machine comprises a protective device body. The protection device is arranged in front of the plate shearing machine to prevent dangerous situations and comprises a support, a frame, a vertical sliding rail, a sliding block, a hydraulic oil pump, a first oil pipe, a second oil pipe, an upper oil inlet, a lower oil inlet, a hydraulic oil cylinder, a protection door and a pedal. Frame fixed on support, symmetrical vertical sliding rails are arranged on the inner sides of the vertical edges of the frame. The protective door is slidably connected to the vertical sliding rail through a sliding block. A hydraulic cylinder is arranged at the top of the frame; the hydraulic cylinder is connected to the protective door through a piston rod; an upper oil inletand a lower oil inlet are formed in the hydraulic oil cylinder; the upper oil inlet is connected to a hydraulic oil pump through a first oil pipe, the lower oil inlet pipe is connected to the hydraulic oil pump through a sec