Automatic detecting and sorting machine with open-type structure for piston ring and detection method for automatic detecting and sorting machine

The invention discloses an automatic detecting and sorting machine with an open-type structure for a piston ring and a detection method for the automatic detecting and sorting machine. The automatic detecting and sorting machine with the open-type structure for the piston ring comprises a close clearance measuring device, a pressing device, a control box, a light tightness measuring device, a worktable, a ring gauge, a pressing plate, a close clearance measuring device holder, a light tightness measuring device holder and a control box holder, wherein the control box is fixed on the control box holder; the control box holder is rotationally connected with the worktable; the ring gauge is arranged on the worktable; the close clearance measuring device holder and the light tightness measuring device holder are fixed on two sides of the ring gauge in an over-turning manner; the close clearance measuring device and the light tightness measuring device are fixed on the close clearance measuring ...