| 摘要 |
PROBLEM TO BE SOLVED: To increase the output of an engine and to make it lightweight by highfrequency-heating and quenching fillet R sections at connection portions of a crankpin, journals and crank webs, tempering the whole at a low temperature, and applying roll machining to the fillet R sections. SOLUTION: A crankpin 12, bearing metal slide sections of journals 14 and fillet R sections 20, 22 are quenched to form hard layers 24. The bending of the whole crankshaft 10 is corrected by tempering and high-frequency-quenching, and the occurrence of a grinding crack at the time of final grinding can be effectively prevented. The fillet R sections 20, 22 are pressed by rollers 26 for roller machining with the crankshaft 10 rotated. The bending fatigue strength of the fillet R sections 20, 22 can be sharply improved than before, and the crankshaft 10 can effectively cope with a recent request for the high output of an engine and the lightweight engine.
|
