Opening and closing device and opening and closing method of large-size clamp locking structure

The invention relates to an opening and closing device of a large-size clamp locking structure, and relates to the technical field of pressure vessels, the opening and closing device comprises: a square frame arranged at the periphery of a large-size clamp; the upper hydraulic cylinder and the lower hydraulic cylinder are vertically arranged, and the two ends of the hydraulic cylinders are fixed to the cross beam and the arc-shaped section of the square frame correspondingly; the two ends of the hydraulic cylinders are fixed to the vertical beams and the arc-shaped sections of the square frame correspondingly. The bottom ends of the two portal hanging brackets are connected to the left arc-shaped section and the right arc-shaped section respectively; the two rolling table assemblies are arranged between the two portal hanging brackets and the cross beam correspondingly and used for assisting the portal hanging brackets in sliding along the cross beam and adjusting and driving the portal hanging brackets to mo