| 摘要 |
<p>PROBLEM TO BE SOLVED: To execute a hardening which can improve both characteristics of lubricity and wear resistance. SOLUTION: A tank and a cylinder block 14 are shifted with a work table from a first position separated from a hardening head 23 by a prescribed distance to a second position where the head 23 is positioned, and after positioning a cylinder bore just below the hardening head 23, when a non-magnetic conductive member 51 inserted into the bore is positioned at the normal position without interference, an induction hardening is executed in a liquid. At a position between the first position and the second position, the position of the bore is detected. In this case a master ring is shifted to just below a bore position measuring instrument through the work table, and successively, the bore position measuring instrument is lowered by a motor for elevating/lowering the bore position measuring instrument and this bore position measuring instrument is inserted into the master ring to confirm the position of the master ring. The bore of the cylinder block 14 is shifted through the work table so as to position it just below the bore position measuring instrument.</p> |
