Nondestructive Structure Test of Cam-Shaft Using both Eddy Current and X-Rays

The cam-shaft for the internal-combustion engine needs to be chilled at the foundry stage to rise the cam hardness, but unexpected chilled structures could occur on the sensor plate surface. If chilled structures exist on the sensor plate, a grinding tool may break when grinding sensor plate, or the specified shape may be unable to be produced due to resistance arising from the hyper-hardness of the chilled structures. For this reason, developing an inspection technique and a device for detecting unnecessary chilled structures before grinding the cam-shaft and for determining the rejection and removal of cam-shafts with chilled structures detected was necessary.