To enable defective cans to be removed precisely even when an error occurs as to the speed at which the cans are conveyed, so as to simplify internal pressure inspection, by actuating a defective can removing device based on can detection signals for those cans which have been passed through can internal pressure detection and on the judgment on inadequate can internal pressure.
When a can conveyed by a belt conveyor 100 along a can conveying route R1 in X direction is sensed by a can sensor 420, a sensing signal is input to a controller to actuate an inspection program. Then, while the can that has reached a roller window 354b is being conveyed by a can feed roller 354, detection signals of a can body pressure detector 370 (390) and of a can lid pressure detector are input to the controller, which in turn calculates the expanding force of the can lid and the amount by which the lid is pressed into the body 2a of the can, on the basis of these signals, and compares the calculated values with reference values to determine whether or not the can internal pressure is adequate. If there is a can that is defective as to its internal pressure, a defective can removing device 500 is actuated based on a detection signal of a can detector 430 sensing the cans that have been passed through inspection and on judgement of defectives, so that the defective can is removed from the top of the conveyor 100.
YOKOYAMA MITSUO
ITO SABURO
USUI FUMIHIKO
