PURPOSE: To shorten stages, to produce a mass production effect, and to reduce the cost by quenching each journal of a cam shaft after machining and by remelting and hardening the surface of each cam after rough grinding so as to make a stage for subjecting the journal part to tufftriding and related stages unnecessary.
CONSTITUTION: Each journal of a cast cam shaft is machined, the surface of each cam is roughly ground, the journal is quenched, and the necessary surface of the cam is remelted and hardened. After cooling, the journal part and the cam surface are subjected to finish grinding. A conventional stage for subjecting the journal part to is made unnecessary, preannealing and preheating stages which are carried out to prevent bending during the tufftriding are eliminated, and a stage for finishing the journal part by lapping after the tufftriding is made unnecessary. Thus, stages are shortened, a mass production effect is produced, and the costs of equipment and production are reduced.
NAKAJIMA FUSAO
KAWAGUCHI MASATOSHI
MAKITA TSUYOSHI
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