Patent ID: 6899071
Filing Date: 2005-05-31
Classification: F01L

Abstract:
1. A lash adjuster comprising a lifter body including an end plate having a top surface and a bottom surface formed with an axial blind threaded hole having female threads, said lifter body axially slidably mounted between a cam and a stem of a valve with said top surface in contact with the cam, an adjuster screw having male threads on its outer periphery which are in threaded engagement with the female threads of said threaded hole, and an elastic member mounted in said threaded hole so as to bias said adjuster screw axially, said female threads of said threaded hole and said male threads of said adjuster screw being serration-shaped and having pressure flanks which receive pressure applied to said adjuster screw in such a direction as to push said adjuster screw into said threaded hole, and clearance flanks arranged between the adjacent pressure flanks, said pressure flanks having a greater flank angle than said clearance flanks, one of the inner periphery of said threaded hole and the outer periphery of said adjuster screw being formed with a plurality of axial grooves that divide said female threads or said male threads into a plurality of separate sections in a circumferential direction, and the pressure flanks of said female threads or said male threads that are not circumferentially divided by said axial grooves are formed with rugged surfaces, wherein said rugged surfaces are satin-finished surfaces formed by shot peening.