| 摘要 |
PURPOSE:To produce a titled plunger with good productivity by machining the inside circumferential surface of the open end of a blank material in precedence to the 1st pressing in which said material is drawn to a stepped shape, and forming simultaneously an undercut shape in the part adjacent to a seat surface in the 2nd pressing stage. CONSTITUTION:After oil holes 2, 3 are formed in the bottom and circumferential wall of a bottomed cylindrical blank material 1, the inside circumferential surface of the open end 4 of the material 1 is machined to an inverted circular cone shape having a thin-walled open end face side. The open end 4 side of the material is then drawn over the specified length and the material 1 is pressed to a stepped shape having a tapered shoulder 5. The open end is drawn to a semispherical seat face 6 for receiving a rocker arm and the part adjacent to the face 6 is pressed to an undercut shape.
|
