DEVICE FOR DETECTING PLATE THICKNESS FOR HOLLOW METALLIC BODY

摘要

PROBLEM TO BE SOLVED: To provide a plate thickness detecting device for a hollow metallic body 11 that can detect changing tendency of the plate thickness of the hollow metallic body 11, in a short time. SOLUTION: A magnetic field generator 12 is attached ring-like on the outer of the hollow metallic body 11 so that the magnetic field generator 12 is movable in the axial direction of the hollow metallic body 11; an AC power supply of a predetermined frequency is supplied from a power supply 13 to the magnetic field generator 12, corresponding to the type of the hollow metallic body 11; and then a magnetic field is generated from the magnetic field generator 12 to the axial direction of the hollow metallic body 11. An induced voltage detector 14 is attached ring-like on the outer of the hollow metallic body 11 in the vicinity of the magnetic field generator 12 so as to move in the axial direction of the hollow metallic body 11 linked with the magnetic field generator 12, and an induced current which changes corresponding to the plate thickness or the magnetic state is detected as an induced voltage by the magnetic field in the axial direction of the hollow metallic body 11 and then detects the plate thickness of the hollow metallic body. COPYRIGHT: (C)2005,JPO&NCIPI