GB1352674A - Deceleration control circuit for an internal combustion engine fuel control system - Google Patents

Abstract

1352674 Electronic fuel control system BENDIX CORP 14 Dec 1972 [13 Jan 1972] 57760/72 Heading G1N In an I.C. engine, electronic fuel injection system having electrical sensors, including an intake manifold pressure sensor 18 and an engine speed sensor 19, and a computer 17 responsive to signals from the sensors to provide injector control signals, a deceleration control circuit is responsive to an operator's demand for deceleration, this circuit including a time rate of change sensor 29 responsive to the signals from the pressure sensor 18 to provide a first signal when the manifold pressure decreases at a rate faster than a predetermined rate, and a control switch 26, 31 responsive to the first signal to control the computer in such a way as to curtail or terminate injection. As shown, the switch 26 is also responsive to signals from an engine speed comparator 25 and a pressure comparator 27. The comparator 25 compares a signal from the speed sensor 19 with a reference signal representing a predetermined engine speed to provide an output signal when the engine speed is above this predetermined value. The comparator 27 provides an output signal when the manifold pressure is above a predetermined pressure value. The switch 26 is responsive only to coincidence of signals from the comparators 25, 27 and the first signal from sensor 29 to set output switch 31 (a bistable multivibrator) which then generates an inhibitory signal. Another comparator 28 is provided to produce an output signal when the manifold pressure is above a second predetermined value, a reset switch 30 being provided and being responsive to coincidence of an output from comparator 28 and a second output from sensor 29 indicating a rate of charge slower than the predetermined rate, to reset the switch 31 and terminate the inhibitory signals. Details of the circuitry of Fig. 2 are described with reference to Figs. 3 and 4, (not shown). In an alternative embodiment, Fig. 5, (not shown), the speed comparator is omitted. Signals from other engine sensors may be added to the set and reset switches 26, 30. The inhibitory signal may be used to completely terminate injection by preventing the generation of injection control pulses by the computer, Fig. 6, (not shown), or may be used to prevent the generation of at least one injection pulse in each cycle, using a switch, Fig. 7, (not shown), or to shorten the injection pulses using a delay circuit, Fig. 8, (not shown). Signals from engine sensors may be applied to modify the delay period.