Crankshaft quenching method, quenching apparatus, and crankshaft manufacturing method

摘要

PPROBLEM TO BE SOLVED: To prevent generation of cracks during the hardening and season cracking which is delayed fracture. PSOLUTION: When cooling a pin 1 and/or a journal 2 after they are heated, only cylindrical portions 1c and 2c and fillet R portions 1a and 2a of the pin 1 and/or the journal 2 are cooled, but a thrust portion is not cooled. Shoulder parts 1e and 2e and/or top portions 1d and 2d of the pin 1 and/or the journal 2 are also cooled as necessary. By adequately realizing a cooling method and a cooling range, the tensile residual stress causing quenching crack or season cracking can be reduced, the productivity can be enhanced by omitting the tempering after the induction hardening, and the failure cost caused by cracks can be reduced. PCOPYRIGHT: (C)2005,JPO&NCIPI