Control of fuel-injected IC engine, with exhaust catalyst, in secondary-air mode

摘要

The method involves an exhaust gas catalyser (1) and a control system (2) for the IC engine injection valves (10,11,12,13) which maintains optimum Lambda values in the exhaust gas duct, relative to the permitted emission levels. The injection times (Ti) of the injection valves are controlled according to the total quantity of air (M) with allowance for other parameters. The total air-quantity when operating in the secondary air mode can be the sum of the quantity of secondary air (Ms) and the aspirated air (Ma). An additional control parameter can be the motor speed, and the injection times for the individual cylinders can be calculated from the formula: Ti = 2M / (14.5 Lambda .k.i.n) (Lambda = required Lambda value; k = injection valve constant; i = number of cylinders and n = revs).