METHOD AND DEVICE FOR MAKING CRANKS

摘要

A method and an apparatus for forging single crank throw elements comprising upsetting a rough piece in a ring-segment compression die to form a blank having opposite shoulder portions with a narrowing connection portion, the connection portion narrowing from both shoulder portions to a central narrowest section. The blank is placed in a die with the shoulder portions resting against inclined surfaces of the die such that clear spaces are formed between the shoulder portions and the inclined surfaces. A force is applied against the narrowing connection portion in a direction perpendicular thereto to deform the narrowing connection portion in a direction to fill the clear spaces while concurrently upsetting forces are applied to the shoulder portions in a direction perpendicular to the direction of the force applied to the connection portion. The upsetting forces are applied by laterally driving die holder elements towards one another by an inclined wedged element which is driven by a press. The die holder elements are supported by articulated links pivotably mounted on fixed structure.