CONTROLLING THE AIR-FUEL RATIO IN AN INTERNAL COMBUSTION ENGINE

摘要

The carburetter (3) has an air inlet (5) and a fuel supply system (9) leading to a main fuel nozzle (10). Air is drawn through a branch (23) from the air inlet (5) and is delivered through a regulator (17) to the fuel supply system (9). The regulator contains a solenoid operated valve (21) which regulates the flow of air to the fuel system. This controls the flow of fuel and therefore the strength of the air fuel mixture delivered to the engine. The solenoid is energised from an electronic control circuit (41) which receives an input from an oxygen detector (35) in the engine exhaust. It controls the solenoid to maintain a mixture strength which produces no pollutants in the engine exhaust.