| 摘要 |
PURPOSE:To form inexpensively a titled boss having excellent dimensional accuracy and satisfactory strength, by pressing out an annular expanding part to one side of a steel plate and a bowl-shaped projecting part to the opposite side, and using a drawing process and a compression forming one after said forming. CONSTITUTION:A steel plate 11 is formed by using a conventional forming press, by pressing out a part of the plate 11 into an annular expanding part 21 to one side of it and pressing out the inside of the part 21 into a bowl-shaped projecting part 22 formed so as to project to the opposite side of the plate 11. The size of the expanding part 21 is made approximately equal to that of a desired large diametral boss 12 in height and width, and a hole 23 to be formed into an inner hole 17 is blanked in the projecting part 22 before or after said forming. Next the projecting part 22 is drawn into a cylindrical shape fitted to the inner hole 17 by a mandrel 31 to constitute a small diametral boss 13. Next the expanding part 21 is formed into a shape conformed to the boss 12 by pressing the end surface of the cylindrical boss 13 in the axial direction as shown by arrows, by using dies 32 and 33. |
