Pneumatically operated valve for IC engine with electronic timing control - has pneumatic piston on valve stem in cylinder on top of combustion cylinder and with valve deflection monitor

摘要

The cylinder head has a pneumatic chamber above each combustion chamber, and separated from same by a wall through which the valve guides (14) locate the valve stems. Each valve stem is fitted with a piston (18) and the two pneumatic chambers are linked to solenoid valves (58, 57). The exact movement of the piston is controlled by a timing control circuit (66) which also monitors the deflection of the valve stem. The top of the valve stem has an iron shaft (44) moving inside a sampling coil (48) linked to the control circuit. This provides an accurate displacement measurement of the valve. The piston is attached to the valve stem using split collets and the valve is held closed by a valve spring. ADVANTAGE - No camshaft required; accurate timing control; simple to adjust valve timing.