A Non-Throttled Gasoline Engine Using a Variable Shutter Valve

The method reported here is to replace the traditional load control method through throttling by a non-throttled method. This method is known as dynamic shutter control. The control mechanism is sandwiched between engine inlet manifold and inlet valve. The movement, synchronized with engine piston motion, of the shutter valve allows a wide shutter opening at the beginning of suction period and shuts the opening when the required amount of air-fuel mixture has entered into the cylinder. By doing so, the engine load is controlled by admitting the right quantity of mixture into the cylinder without throttling.

The engine fitted with the dynamic shutter control mechanism was tested on an engine dynamometer. The results indicated that, at extreme low load condition, the mechanism could achieve a reduction of more than 40% in fuel consumption.