Supporting point opening and closing type air cylinder

The utility model relates to a fulcrum opening and closing type air cylinder which comprises a hollow cylinder body and an air claw, one end of the cylinder body is provided with a cylinder cover fixed by a check ring, a piston rod is arranged in the cylinder body, the outer side of the piston rod is sleeved with a guide sleeve, the guide sleeve is provided with an annular step stopping part, and a pressing piece is arranged outside the annular step stopping part. Each pneumatic claw comprises a driving part and a claw body part which are in a 7 shape, each driving part comprises a pressing wheel, a hinge shaft and a fork-shaped limiting part, the pneumatic claws are movably hinged to the movable grooves through the hinge shafts, the two pneumatic claws are oppositely arranged, the tail ends of the piston rods are provided with connecting ends, and the connecting ends are connected with the piston rods. The connecting end is provided with a transverse open groove, the fork-shaped limiting parts are arranged i