EXPANDABLE HYDRAULIC TAPPET WITH A VARIABLE EXIT VALVE

摘要

The expandable hydraulic tappet with a variable exit valve is supplied for use in an ic-engine to selectively vary timing by altering the effective profile of a camshaft. The tappet expands to extend the drive train between the camshaft and a camshaft operated drive train by enlarging and filling an internal hydraulic chamber with a non-compressible hydraulic fluid via an inlet port and inlet valve. The fluid is retained in the tappet chamber until a predetermined pressure is attained when an exit valve opens to exit the pressurised fluid from the chamber at a predetermined rate. The exit valve includes a bore having a predetermined configuration to provide one or more exit flow rates and also dampen valve operation.