VALVE TIMING CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

PURPOSE:To stabilize both multi-stage moving position control for a cylindrical gear and valve timing control by enhancing opening accuracy for a drain passage section by a piston. CONSTITUTION:It is assumed that the valve timing of an intake air valve is so constituted as to be variably controlled by letting the multi-stage transformation of a relative rotating angle between a sprocket 1 and a cam shaft 2 be made as a cylindrical gear 12 is moved. The cylindrical gear 12 is moved by controlling the volume of a pressure chamber 13 to be increased/decreased with each drain passage section 21 through 24 selectively opened/closed by a relative movement between a control valve 20 and a piston 15. A seal valve body 32 made of rubber opening the outside open end of each drain passage section 21 through 24 is provided for an engaging groove formed in the inner circumferential surface of the piston 15.