Method of forming a cam-engaged rocker arm

Abstract

A method and system for forming a cam engaged rocker arm includes a stamping process where metal is forced into die cavities to build up material in a desired area of a blank to create an intermediate article. The blank is further formed by a shaving process where the built-up material and additional material is formed into a valve guide for the rocker arm.

1 . A method of manufacturing a cam-engaged rocker comprising: 
 obtaining a metal blank, the blank defined, at least in part, by two opposing surfaces and an outer peripheral surface, the blank having a generally uniform thickness as measured between the two opposing surfaces, wherein the two opposing surfaces each generally lie within a defined plane, the blank further having a valve end, a pivot end, and at least one ear adjacent one of the ends, wherein the ear defines a predetermined portion of the metal blank extending between the two opposing surfaces, and the outer peripheral surface defines, in part, an outline of the ear; and    stamping the metal blank using a stamping die having a cavity to produce an intermediate article, wherein the stamping die is positioned adjacent the metal blank such that the cavity is adjacent one of the two opposing surfaces at the valve end, and the cavity selectively permits a portion of the blank to increase in thickness as the blank is stamped, such that the ear is pressed inward into the end and a projection is formed by the flow of a portion of the metal into the cavity, wherein the volume of the projections is substantially equal to the volume of the ear, and an outline of the intermediate article is substantially equal to the outline of the metal blank without the ear.    
   
   
       2 . The method of  claim 1 , wherein stamping the metal blank includes exerting a force in a predetermined direction, and the plastic flow of the portion of the metal is generally perpendicular to the predetermined direction.  
   
   
       3 . The method of  claim 1 , further comprising pinch forming the projection to create at least one guide.  
   
   
       4 . The method of  claim 3 , wherein pinch forming includes exerting a force in a predetermined direction, and pinch forming results in an additional flow of a portion of the metal to form each guide with a predetermined height, the flow being plastic flow, and wherein the predetermined height is measured generally perpendicular to the predetermined direction.  
   
   
       5 . The method of  claim 3 , wherein pinch forming includes shaving material located between the two opposing surfaces, wherein the shaved material is directed to form at least a portion of the guide, and a shaved area is created.  
   
   
       6 . The method of  claim 5 , wherein a thickness of the rocker arm, as measured between the shaved area and an opposing surface, is greater than a minimum required thickness.  
   
   
       7 . The method of  claim 5 , wherein pinch forming further includes directing the projections to form at least a portion of the guide.  
   
   
       8 . The method of  claim 3 , wherein pinch forming further includes pinching a predetermined amount of material between a pair of cams and a center post.  
   
   
       9 . The method of  claim 1 , wherein there are a pair of guides, and there is a separate ear for each guide.  
   
   
       10 . A method of manufacturing a cam-engaged rocker comprising: 
 obtaining a metal blank, the blank defined, at least in part, by an outer peripheral surface and two opposing surfaces, the blank having a generally uniform thickness as measured between the two opposing surfaces, wherein the two opposing surfaces each generally lie within a defined plane, the blank-further having a valve end and a pivot end, wherein the metal blank contains a predetermined amount of a metal; and    stamping the metal blank by exerting a force on the metal blank through a stamping die having a cavity, wherein the stamping die is positioned adjacent the metal blank such that the cavity is adjacent one of the two opposing surfaces at the valve end, and the cavity is adapted to permit a portion of the blank to increase in thickness, such that a projection is formed by the flow of the metal into the cavity, and wherein the force is exerted through the outer peripheral surface.    
   
   
       11 . The method of  claim 10 , wherein stamping the metal blank includes exerting a force in a predetermined direction, and the flow of the metal is generally perpendicular to the predetermined direction.  
   
   
       12 . The method of  claim 10 , further comprising pinch forming the projection to create at least one guide.  
   
   
       13 . The method of  claim 12 , wherein pinch forming includes exerting a force in a predetermined direction, and pinch forming results in an additional material thickness, wherein the additional material thickness is measured generally perpendicular to the predetermined direction.  
   
   
       14 . The method of  claim 10 , wherein pinch forming includes shaving material between the two opposing surfaces, wherein the shaved material is directed to form at least a portion of the guide, and a shaved area is created.  
   
   
       15 . The method of  claim 14 , wherein a thickness of the rocker arm, as measured between the shaved area and an opposing surface, is greater than a minimum required thickness.  
   
   
       16 . The method of  claim 14 , wherein pinch forming further includes directing the projections to form at least a portion of the valve guide.  
   
   
       17 . The method of  claim 12 , wherein pinch forming further includes pinching a predetermined amount of material between a cam and a center post.  
   
   
       18 . A method of manufacturing a cam-engaged rocker comprising: 
 providing an article, the article defined, at least in part, by a body defined in part by a first surface and an opposing second surface, the first surface having a projection that extends from the body, the article further having a valve end and a pivot end, wherein the article contains a predetermined amount of a metal; and    shaving a portion of the metal between the first surface and the opposing second surface to form a guide, wherein the guide is formed from metal that includes at least a portion of the projection, and the guide is defined at least by an inboard surface and an outboard surface.    
   
   
       19 . The method of  claim 18 , further comprising: 
 stamping the article by exerting a force on the metal blank through a stamping die having a cavity, wherein the stamping die is positioned adjacent the article such that the cavity is adjacent the metallic surface at the valve end, and the cavity is adapted to permit a portion of the article to increase in thickness, such that the projection is formed by the plastic flow of metal into the cavity, and wherein the force is exerted through an outer curved surface    
   
   
       20 . An intermediate article of manufacture in the manufacture of a cam-engaged rocker arm having a guide, the article comprising: 
 a metallic body, wherein the body is defined by two opposing surfaces and an outer peripheral surface disposed therebetween, wherein the body has a thickness measured between the metallic surface and the opposing surface, and the metallic surface defines at least one projection that extends from the body; wherein the projection is selectively formed into the guide.