GB1461766A - Fuel control systems for ic engines - Google Patents

Abstract

1461766 Automatic control of fuel injection in I C engines LUCAS ELECTRICAL Ltd 9 Jan 1974 [16 Jan 1973] 2239/73 Heading G3N The quantity of fuel injected into an engine is controlled in accordance with the air mass flow into the induction manifold which has been measured during a previous time period using a system employing digital techniques. In the system shown, the injectors are divided into two groups and are controlled by signals from bi-stables 21, 22 respectively. The induction air mass flow is measured by known means 10 to obtain an analogue signal which controls the voltage controlled oscillator 12 to build up a count proportional to the air mass flow in counter 13 for each half engine cycle determined by contact breaker 14, 24. At each operation of the contact breaker the count in 13 is shifted to the memory counter 15, 16 respectively and counter 13 reset after a delay. After a delay imposed by delay 23 bi-stable 21 is set to gate clockpulses into counter 15 to reduce the count to zero when the bi-stable is reset. The set period of the bi-stable provides the injection period which is thus proportional to the mass flow divided by engine speed. The bi-stable 22 and counter 16 are similarly operative for the other groups of injectors under the control of contact 24. In a modification a bi-stable circuit, counter and circuit breaker contact are provided for the individual injectors of an engine, Fig. 3 (not shown).