Hydraulically adjusted IC engine valve tappet - has conical face piston spring loaded and pressurised by engine oil via non-return valve

摘要

The combustion engine valve (2) is operated via a tappet (3), containing hydraulically absorb valve clearance. These comprise a cylinder (5) containing a piston (6) which is spring-loaded (10) in a direction at right angles to the valve centre line to eliminate clearance via a conical surface (7) on the side of the piston. During valve operation, the piston bears on oil in a chamber (9) which connects (14-18) with the engine oil circuit via a non-return valve (12,13). When the valve is not ooerated, the spring (10) moves the piston into the oil-filled chamber (15) on its other side so that oil passes to the chamber (9) via the valve (12,13) and the valve clearance is eliminated.