US Patent 7827946 Engine valve lifter mechanism of internal combustion engine

An upper surface of a head part of a valve lifter has a predetermined turn back portion at which, with a variable valve control device kept controlled to induce a maximum lift of an engine valve, a swing stroke of a rounded cam surface of a swing cam relative to the upper surface of the head part changes a traveling direction from a radially outward direction for opening the engine valve to a radially inward direction for closing the engine valve. An inlet end part of an oil hole formed in the head part is placed at a radially inside position of the upper surface other than a position where side edges of the rounded cam surface of the swing cam are in contact with the inlet end part of the oil hole when the rounded cam surface is placed in the vicinity of the turn back portion.