Engine crankshaft made by forging

摘要

An engine crankshaft (1) made by forging, that has larger counter weights (8) without increasing a manufacturing cost. Engaging two dies with each other performs the forging. Each counter weight (8) has a plurality of inclinations (θ1,θ2) to facilitate removal of the dies from the crankshaft after the forging process is complete. The inclinations are reduced as they are apart from a die mating surface (P). The maximum thickness (T) of each counter weight (8) is not enlarged so that interference between the counter weights and neighboring parts is avoided. No machining is required after the forging process.