| 摘要 |
PROBLEM TO BE SOLVED: To provide a method and an apparatus for manufacturing a crankshaft ensuring a large offset quantity of a pin part with respect to a journal part by using a cold forging in a manufacturing process of the crankshaft. SOLUTION: The apparatus for manufacturing the crankshaft includes a movable type material restraining section 17 and a fixed type material restraining section 27 which are disposed in the lower side than a movable die side holding part 12 in a movable die 10 and the upper side than a fixed die side holding part 22 in a fixed die 20, respectively and which suppress deformation of a round bar-like material W to a counter-offset direction side when a middle portion Wm of the round bar-like material W is offset. A first floating die material restraining part 37a and a second floating die material restraining part 37ba are formed on the upper side than a holding part 32 in a floating die 30 and on the lower side than the holding part 32, respectively to suppress deformation of the round bar-like material W in the offset direction side when the middle portion Wm of the round bar-like material W is offset. COPYRIGHT: (C)2011,JPO&INPIT
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