Patent ID: 6901896
Filing Date: 2005-06-07
Classification: F01L

Abstract:
1. An arm type valve gear wherein an engaging hole is formed in an arm pivoted by the rotation of a cam at its end on the pivoting side to push down a valve stem through a lash adjuster mounted in the engaging hole, wherein said lash adjuster comprises a nut member received in said engaging hole, an adjuster screw having male threads on the outer periphery thereof that are in threaded engagement with female threads formed on the inner periphery of said nut member, an elastic body for biasing said adjuster screw toward said valve stem, a ball joint having its upper portion joined to said nut member so as not to rotate relative to said nut member, while supporting the bottom end of said adjuster screw, and said ball joint having its bottom end face in surface contact with the top end face of said valve stem, and wherein the female threads of said nut member and the male threads of said adjuster screw are serration-shaped such that pressure flanks which bear axial push-in force applied from said valve stem to said adjuster screw have a greater flank angle than clearance flanks.