| 摘要 |
PURPOSE:To reduce working man-hour and to improve the accuracy in sectional shape and yield in the stage of winding a blank material around a bending die which is united to one body with a chuck, by working preliminarily the section of the blank material to a prescribed shape in the same stage. CONSTITUTION:A blank material 1 having a rectangular section is inserted into the space part of a recessed roll 7a, and the left end thereof is chucked 5. A base 6 fixed to a bending die 4 and the chuck 5 is rotated to bend the material 1 by rotating and pulling. The blank material 3 after passing the rolls and before bending is preliminarily worked to a trapezoidal section so that the material 8 has a rectangular shape in the bent part. |
