| 摘要 |
A method of forming a generally cylindrical part from a generally flat, rectangular metal blank in a punch press constitutes the steps of primarily forming the blank by bending two opposite longitudinal edge portions of the blank to predetermined configurations with respect to the remainder of the blank in a first die section. The primarily formed blank is transferred to a second die section wherein it is secondarily formed downwardly over a mandrel having an axis parallel to the two longitudinal edge portions. In the secondarily formed blank, the two longitudinal edge portions are thus turned inwardly toward each other. The secondarily formed blank has a generally oval or U-shaped transverse section. The secondarily formed blank is then transferred to a third die section wherein the part is formed by curling the blank so that the two longitudinal edges are adjacent one another. The apparatus of the present invention is adapted for use in a punch press which has a pair of spaced-apart die shoes and means for moving one of the die shoes toward and away from the other during each press stroke. The apparatus includes a first die section for primarily forming the blank, a second die section for secondarily forming the primarily formed blank, and a third die section for curl-forming the secondarily formed blank. A punch press feed is provided adjacent the first die section for transferring successive primarily formed blanks to the second die section. Each successive primarily formed blank transfers a preceding secondarily formed blank into the third die section to be finish formed.
|
