| 摘要 |
<p>PROBLEM TO BE SOLVED: To restrain the warping after hardening with a simple operation. SOLUTION: When journal parts J1-J5 and pin parts P1-P4 in a crank shaft W are hardened to the outer surface of the whole body, the hardening is executed except the journal part J3 positioned at the central part in the shaft direction of the crank shaft W. After hardening, the warping of the crank shaft W is measured. When the hardening on the outer surface of the journal part J3 positioned at the central part in the shaft direction of the crank shaft W is executed, the electric power supplied to the heating coils 3J-3 is adjusted in the peripheral direction so as to remove the measured warping.</p> |
