ENGINE WITH VARIABLE LIFT VALVE MECHANISM

Title:

ENGINE WITH VARIABLE LIFT VALVE MECHANISM

Document Type and Number:

WIPO Patent Application WO/2004/046512

Kind Code:

A1

Abstract:

An internal combustion engine is described having a valve mechanism which comprises a gas exchange poppet valve (14), a camshaft (10) rotatable in synchronism with the engine crankshaft and having a cam (12) for operating the valve (14), a valve actuator (20) acting on the poppet valve (14) to open and close the valve, and an intermediate rocker (30) having a follower (34) acted upon by the cam (12) and a contoured surface (36) that acts on the valve actuator (20) to open and close the valve (14) in synchronism with the rotation of the cam (12), the intermediate rocker (30) having a pivot axis that is movable in order to vary the valve lift. In the invention, the intermediate rocker (30) is mounted about a pivot shaft (32) that is moved to vary the valve lift in response to rotation of the pivot shaft (32) about its own axis, and the pivot shaft (32) is constrained to move along a path which is such that, while the cam follower (34) is on the base circle of the cam (12), the valve actuator (20) remains stationary and a substantially constant clearance is maintained between the contoured surface (36) of the intermediate rocker (30) and the valve actuator (20) during displacement of the pivot shaft along the path.

Inventors:

METHLEY IAN (GB)

Application Number:

PCT/GB2003/004864

Publication Date:

June 03, 2004

Filing Date:

November 12, 2003

Export Citation:

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Assignee:

MECHADYNE PLC (GB)
METHLEY IAN (GB)

International Classes:

F01L1/34; F01L13/00; (IPC1-7): F01L13/00; F01L1/34

Foreign References:

US4397270A	1983-08-09
DE19708484A1	1998-09-10

Other References: