초록 ▼

A work 12 is selectively loaded one of forming portions 20, 22, and so on, which are formed on a mandrel 18. Then, the work 12 is pressed between the selected forming portion and a forming roll 10 and rotated together with the forming roll 10 and the mandrel 18 in this state, thereby rolled and form

A work 12 is selectively loaded one of forming portions 20, 22, and so on, which are formed on a mandrel 18. Then, the work 12 is pressed between the selected forming portion and a forming roll 10 and rotated together with the forming roll 10 and the mandrel 18 in this state, thereby rolled and formed a groove on its inner surface. The mandrel 18 is provided movably in its axial direction, and the forming portions 20, 22, and so on, are subsequently selected for rolling the work 12 step by step. After finishing the rolling, the work 12 is unloaded from the mandrel 18, guided by a work guiding passage, and is supplied to the sizing device 120, wherein the work 12 is pushed into a die 121 and sized the outer diameter thereof.

대표청구항 ▼

An apparatus for rolling a ring-shaped work comprising: a forming roll contacted with the outer surface of a ring-shaped work; a mandrel provided movably in the axial direction thereof; a plurality of forming portions formed on the outer surface of said mandrel, wherein said forming portions are arr

An apparatus for rolling a ring-shaped work comprising: a forming roll contacted with the outer surface of a ring-shaped work; a mandrel provided movably in the axial direction thereof; a plurality of forming portions formed on the outer surface of said mandrel, wherein said forming portions are arranged at an arbitrary distance along the axial direction of said mandrel, wherein one of said forming portions is selected according to the moving distance of said mandrel in said axial direction, and said selected forming portion is contacted with the inner surface of said work for rolling the work with a cooperation of said forming roll; a mandrel driving device which drives said mandrel in said axial direction for selecting one of said forming portions, a mandrel backup roll; a work holding device inserted between said backup roll and said work which holds said work for making a gap between said work and said forming portions when said mandrel is axially moved for selecting one of said forming portions.