Patent ID: 6729288
Filing Date: 2004-05-04
Classification: F01L,Y10T

Abstract:
A lash adjuster for use in a valve gear, comprising a lifter body having an end plate, mounted between a cam and a valve stem and supported so as to be slidable in the axial direction, an adjust screw in threaded engagement with a threaded hole formed in the bottom surface of the end plate of said lifter body, and an elastic member biasing said adjust screw toward the top end of said valve stem, wherein threads of female threads of said threaded hole and male threads formed on the outer periphery of said adjust screw are serrated so that the flank angle of pressure flanks of the male threads and the female threads, which receive axial push-in force applied to said adjust screw, is larger than the flank angle of clearance flanks of the male threads and the female threads, wherein the surface roughness Ra of the pressure flanks of at least one of said female threads and said male threads is set to 0.4 or over.