Gasoline engine torque regulator with partial speed correction

TLDR: In this article, a gasoline engine torque regulator is proposed to reduce the quantities of harmful oxides of nitrogen emitted via the exhaust of a four-stroke cycle gasoline engine and to increase the efficiency of the engine at part load, with an engine torque characteristic either approximately constant with engine speed or alternatively controllably decreasing with increasing engine speed.

Abstract: The gasoline engine torque regulator described herein provides means of reducing the quantities of harmful oxides of nitrogen emitted via the exhaust of a four stroke cycle gasoline engine and also of increasing the efficiency of the engine at part load, with an engine torque characteristic either approximately constant with engine speed or alternatively controllably decreasing with increasing engine speed These beneficial objects are achieved by adjustably delaying the closing of the engine intake valve as a means of controlling the engine torque, the opening of the intake valve remaining fixed This manner of intake valve opening and closing can be achieved by adding to the conventional intake valve operating mechanism a dashpot device with a check valve and a positive displacement flow regulator The check valve allows ready flow of the dashpot fluid between dashpot chambers when the intake valve is being opened but closes and forces fluid to flow oppositely, during intake valve closing, at least partially via the positive displacement flow regulator which proportions the flow and hence the rate of valve closure to the speed of the engine With intake valve closing thereby delayed, a portion of the air-fuel mixture, drawn into the engine cylinder during the intake stroke, is pushed back into the intake manifold during the compression stroke As a result less air-fuel mixture remains in the engine cylinder and the engine torque is reduced, the extent of such torque reduction increasing as the intake valve closing is longer delayed The engine compression ratio is reduced at reduced torque and, in consequence, gas temperatures during compression, combustion and expansion are reduced, producing a beneficial decrease in the quantities of oxides of nitrogen formed and subsequently emitted Part load efficiency of the engine is increased because pumping work is essentially eliminated