Formed outer arm for rocker arm assembly

Abstract

A method of cold forming an outer arm of a rocker arm assembly in a cold forming machine includes providing a slug having a first end and a second end, extruding the slug at the first end to establish two different widths of the slug, compressing the slug to form an upper angled surface and a lower angled surface at the second end, and compressing the slug to form an inner arm window defined by a pair of side walls and a pair of end walls.

What is claimed is: 
     
         1 . A method of cold forming an outer arm of a rocker arm assembly in a cold forming machine, the method comprising:
 providing a slug having a first end and a second end;   extruding the slug at the first end to establish two different widths of the slug;   compressing the slug to form an upper angled surface and a lower angled surface at the second end; and   compressing the slug to form an inner arm window defined by a pair of side walls and a pair of end walls.   
     
     
         2 . The method of  claim 1 , further comprising rotating the slug approximately 90° between extruding the slug and compressing the slug to form the upper and lower angled surfaces. 
     
     
         3 . The method of  claim 1 , wherein the step of extruding the slug at the first end includes providing a punch force substantially along a longitudinal axis of the slug. 
     
     
         4 . The method of  claim 3 , wherein the step of compressing the slug to form the upper and lower angled surfaces includes providing a punch force substantially orthogonal to the longitudinal axis. 
     
     
         5 . The method of  claim 1 , further comprising compressing the slug to form the second end with a pivot body including an interfacing seat configured to engage a hydraulic lash adjuster, wherein the first end is configured to engage an engine valve. 
     
     
         6 . The method of  claim 1 , further comprising punching the slug to remove a bottom wall of the slug to further form the inner arm window. 
     
     
         7 . The method of  claim 1 , further comprising forming at least one pair of axle holes in the pair of side walls. 
     
     
         8 . The method of  claim 1 , wherein the slug is heated and warm or hot formed prior to cold forming. 
     
     
         9 . The method of  claim 1 , wherein the providing a slug includes shearing wire to a desired length to form the slug. 
     
     
         10 . A method of cold forming an outer arm of a rocker arm assembly using a cold forming machine having six forming stations, the method comprising:
 shearing wire to a desired length to form a slug having first and second ends;   at the first forming station, extruding the slug and flattening the first end;   at the second forming station, compressing the slug to form the second end with an upper angled surface and a lowered angled surface;   at the third forming station, compressing the slug to form an inner arm window defined by a pair of side walls, a pair of end walls, and a bottom wall;   at the fourth forming station, compressing the slug to form the second end with a pivot body including an interfacing seat configured to interface with a hydraulic lash adjuster;   at the fifth forming station, punching the slug to remove the bottom wall; and   at the sixth forming station, forming the slug to final workpiece dimensions.   
     
     
         11 . The method of  claim 10 , wherein the forming the slug to final workpiece dimensions includes forming a first pair of axle holes in the pair of side walls. 
     
     
         12 . The method of  claim 11 , wherein the forming the slug to final workpiece dimensions further includes forming a second pair of axle holes in the of side walls. 
     
     
         13 . The method of  claim 10 , further comprising heating the slug prior to the first forming station. 
     
     
         14 . The method of  claim 13 , further comprising warm or hot forming the slug in the first, second, third, and fourth forming stations, and cold forming the slug in the remaining forming stations. 
     
     
         15 . The method of  claim 14 , further comprising a seventh forming station where the slug is cooled and coined after the fourth forming station and before the fifth forming station. 
     
     
         16 . The method of  claim 10 , further comprising rotating the slug approximately 90° between the first forming station and the second forming station. 
     
     
         17 . The method of  claim 10 , wherein the first forming station provides a punch force substantially along a longitudinal axis of the slug. 
     
     
         18 . The method of  claim 17 , wherein the second forming station provides a compressing force substantially orthogonal to the longitudinal axis. 
     
     
         19 . The method of  claim 17 , wherein the third forming station provides a compressing force substantially orthogonal to the longitudinal axis. 
     
     
         20 . The method of  claim 17 , wherein the second forming station, the third forming station, the fifth forming station, and the sixth forming station each provide a compressive force substantially orthogonal to the longitudinal axis.