| 摘要 |
PURPOSE:To take preventive maintenance measures against an abnormal increase in internal air leakage, by detecting the internal air leakage from a sealing valve for holding the inside of a can body volume part at specific pressure for a specific time. CONSTITUTION:Compressed air of specific pressure from a compressed air source CA is introduced into the volume part of a can body C through blast valves SV1 and SV2 and the sealing valve SV3 to seal the compressed air in the volume part of the can body C with the sealing valve SV3; and the introduction of the compressed air is stopped with the blast valve SV1 and the compressed air in the system of the blast valve SV2 is discharged to the air. Then, internal air leaking out of the valve seat SV3 is led to the air through the blast valve SV2 and an internal leakage detector L detects the degree of the internal air leakage from the valve seat of the sealing valve SV3 in a specific time. Further, a pressure measuring instrument PSW detects the internal pressure value of the can body volume part decreasing for a specific time owing to the leakage of the sealed compressed air from a compaction defective part and the valve seat part of the sealing valve SV3 to the air to evaluate the compaction of the can body C from the degree of the internal leakage and the internal pressure value of the can volume part. |
