PURPOSE: To reduce the shearing strain of a shaft material by constituting a pass so that the work partial charge is migrated continuously from one pair to the other pair in connection with an advance, with respect to two pairs of rollers.
CONSTITUTION: A pair of rollers are formed by placing two pairs of rollers 1, 1, 1 and 1 being axially symmetric in the pair so that roller shafts 3, 3, 3 and 3 are twisted and arranged alternately, and share a deformation area in the periphery of a pass line 2. With respect to its pair of rollers, a pass is constituted so that a work partial charge is migrated continuously from one pair to the other pair in connection with an advance. Driving of all the rollers is executed by a reinforcing ring 5 for containing them. A twist angle A of the pair of rollers whose work partial charge is large on the delivery of the pass is made larger in the same direction than a twist angle A of the other pair of rollers. The diameter of the roller is made larger as the work partial charge becomes larger. In such a way, noncoincidence of speeds of the shaft material and the roller can be softened.
JPS61119310A | 1986-06-06 |
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