| 摘要 |
A cold-formed ball plunger blank (300) is provided for use in manufacturing a finished ball plunger (116) used in a hydraulic lash adjuster that includes a check valve assembly (126) having a check ball (130) and a retainer (126). The ball plunger blank includes a cup-shaped member that extends from a first end to a second end along a longitudinal axis. The cup-shaped member includes a ball portion (140) adjacent the first end of the member and a body portion (302) adjacent the second end of the member. The body portion has a cavity (310) disposed therein, a counterbore (148) extending from the second end of the body towards the first end of the member, and a shoulder (173) that separates the cavity from the counterbore and at least partially closes the cavity. The shoulder defines a ball seat surface configured to receive the check ball and a retainer receiving surface configured to receive the retainer, wherein the ball seat surface and the retainer receiving surface are to sized to the final dimensions of the finished ball plunger. A method of cold-forming a ball plunger blank including providing a slug having first and second ends, backward extruding the slug at its first end to form a cavity that is defined by a wall, forming a generally ball-shaped outer surface at the second end of the slug to final dimensions, and upsetting at least a portion of the wall to form a shoulder that at least partially closes the cavity and defines a ball seat surface to its final dimensions. |
