Cylinder-head valve with variable timing for IC engine - has sprung coupling to camshaft with hydraulic system with control valves to shorten cylinder valve timing.

摘要

The cylinder head valve (1) is operated by a sprung piston (9) coupled to a cam follower (21) by a second spring. A hydraulic coupling (20) between the cam follower and piston is regulated by sprung pressure storage chamber, which can be lifted via secondary control valves (46, 48). The drive for the storage chamber is via a tapping (43) to the trapped hydraulic volume. The system enables the storage system to lift rapidly, reducing the trapped hydraulic volume and causing the cylinder head valve to close more rapidly, and before the end of the timing period. This provides a more responsive valve action for faster speeds. ADVANTAGE - Uses simple solenoid valves; no large hydraulic pressure required; improved engine performance at higher speeds.