The invention discloses a pneumatic torque-adjustable cap screwing device capable of flexibly clamping, which comprises a cap screwing thread
bushing, an elastic clamp ring, a rotary cover base, a gland core, a
central spindle seal ring, a tightening nut, an
air cavity, air inlet passages, a hollow rotating shaft, a protecting bush, an axial seal ring, a lower bearing pedestal, a bearing, an air inlet
pipe, an upper bearing pedestal, an adapter sleeve, a connecting seat and a
pneumatic motor, wherein the cap screwing thread
bushing, the elastic clamp ring, the rotary cover base, the gland core, the
central spindle seal ring, the tightening nut, the
air cavity and the air inlet passages form a
bottle cap pneumatic chuck; the hollow rotating shaft, the protecting bush, the axial seal ring, the lower bearing pedestal, the bearing, the air inlet
pipe, the upper bearing pedestal, the adapter sleeve, the connecting seat and the
pneumatic motor form a pneumatic cap screwing drive part; the
bottle cap pneumatic chuck is utilized to flexibly clamp a
bottle cap, the clamping force can be adjusted, the
bottle cap cannot be damaged, and clamp marks cannot be preserved on the
bottle cap. The pneumatic cap screwing drive part can stably screw the
bottle cap in a fixed torque manner according to the predetermined requirements, and the torque of cap screwing can be adjusted and controlled. A pressure relief air passage communicated with the outside is arranged on the lower end surface of the gland core, so that a bottle cap can be conveyed to a certain position. The device has the advantages that the structure is simple, the pneumatic flexible clamp is realized, the pneumatic cap screwing is performed in a torque-adjustable manner, the cap screwing operation is stable and reliable, the cap screwing speed is high and steady, the running cost is low, and the maintenance is facilitated.