CRANKSHAFT AND METHOD FOR MANUFACTURING SAME

摘要

In a crankshaft (200), one hole (213L) formed in a crankpin (213) has a bottom surface with a wider area and is formed to a shallower depth from the surface of the crankpin than the other hole (213M). In the formation of the holes (213L, 213M), a preform (200) for the crankshaft, which has a shape smaller than that of a cavity, is disposed in a mold, and punches are inserted simultaneously into the crankpin (213). Thus, the holes (213L, 213M) are formed simultaneously in both sides of each crankpin (213) of the preform (200).