| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To make a pin part P and the like of a crankshaft W capable of being round-hardened with low distortion. <P>SOLUTION: A semi-open saddle type heating coil 11 is placed at the pin part P of the crankshaft W and the like and an entire peripheral surface of the pin part P and the like is induction-heated by supplying electric power to the heating coil 11 while revolving the crankshaft W. Then, cooling liquid is injected to cool to a part heated by the heating coil 11 by a cooling jacket 12 and, in this process, the pin part P and the like are round-hardened. When the pin part P of the crankshaft W is induction-hardened, rotation number of the crank shaft is set from 45 to 60 (rpm), electric power to be supplied to the heating coil is set from 1.3 to 2.0 (kW/cm<SP>2</SP>) and heating time is set from 5.00 to 6.67 (sec). When a journal part J is induction-hardened, rotation number of the crank shaft is set from 60 to 90 (rpm), electric power to be supplied to the heating coil is set from 1.3 to 2.0 (kW/cm<SP>2</SP>) and heating time is set from 3.34 to 5.00 (sec). <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
