Pressure dependent deceleration cutoff for an internal combustion engine fuel delivery system

Claim 2

In an internal combustion engine fuel control system having an intake manifold pressure sensor means operative to generate pressure dependent signals indicative of engine operating conditions, a fuel control computer operative to generate a set of output signals indicative of the engine fuel requirements for each operational cycle of the engine, and at least one fuel injector responsive to the signals from said computer operative to control fuel delivery to the engine, the improvement comprising: means responsive to just the pressure dependent signals to indicate a demand for deceleration when the pressure dependent signals are indicative of a manifold pressure above a first predetermined pressure and the pressure is decreasing at a rate faster than a predetermined rate, and to generate an inhibitory signal, said inhibitory signal communicated to the fuel control computer controls the operation of said computer and regulates the fuel delivery to the engine during the deceleration period, said means further responsive to just the pressure dependent signals to indicate the end of said demand for deceleration when the pressure dependent signals are above a second predetermined pressure and the pressure is decreasing at a rate slower than said predetermined rate, and to terminate said inhibitory signal to said computer and restore normal fuel delivery to the engine.

Claim 3

The system as claimed in claim 1 wherein said means for generating said inhibitory signal includes: first signal generating means responsive to pressure dependent signals operative to generate a first signal indicative of a pressure in the intake manifold above said first predetermined pressure; SECOND signal generating means responsive to pressure dependent signals to generate a second signal indicative of a pressure in the intake manifold above said second predetermined pressure; a time rate of change detector responsive to the pressure dependent signals operative to produce a first rate of change signal indicative that the manifold pressure is decreasing at a rate faster than said predetermined rate and a second rate of change signal indicative that the manifold pressure is decreasing at a rate slower than said predetermined rate; and a control switch responsive to said first signal from said first signal generating means and the first rate of change signal from said time rate of change detector operative to generate said inhibitory signal, and further responsive to said second signal from said second signal generating means and said second rate of change signal from said time rate of change detector operative to terminate the generation of said inhibitory signal.

Claim 4

The system as claimed in claim 2 wherein said first signal generating means comprises: a first manifold pressure reference circuit operative to generate a first reference signal indicative of said first predeterminable manifold pressure; and a first comparator circuit responsive to said first reference signal and said pressure dependent signal from the manifold pressure sensor operative to produce said first signal when the manifold pressure is higher than said first predetermined pressure established by the first manifold reference circuit; and said second signal generating means comprises: a second manifold pressure reference circuit operative to generate a second reference signal indicative of said second predeterminable manifold pressure; and a second comparator circuit responsive to said second reference signal and said pressure dependent signals from the manifold pressure sensor operative to produce said second signal when the manifold pressure is higher than said second predeterminable pressure established by the second mainfold reference circuit.

Claim 5

The system as claimed in claim 3 wherein said control switch comprises: a set switch operative to produce a signal in response to the coincidence of signals from the first comparator circuit indicating a manifold pressure greater than said first predeterminable manifold pressure and the time rate of change detector indicating the dynamic pressure in the manifold is decreasing at a rate faster than said predeterminable rate; a reset switch operative to produce a signal in response to coincidence of signals from the second comparator circuit indicating a manifold pressure greater than said second predeterminable manifold pressure and the time rate of change detector indicating the dynamic pressure in the manifold is decreasing at a rate slower than said predeterminable rate; and an output switch, switchable from one state to the other in response to the signals from the set and reset switches, operative to control the output signal of the said fuel control computer.

Claim 6

The system as claimed in claim 4 wherein said time rate of change detector comprises: a capacitance; a first resistance in series with said capacitance; a second resistance in parallel with said capacitance and said first resistance, wherein said capacitance, said first resistance and said second resistance comprises a differentiator, said differentiator operative to produce a first differentiated signal when the pressure dependent signal to the differentiator is indicative of a pressure decreasing at a rate faster than said predeterminable rate and operative to produce said second differentiated signal when the pressure dependent signal to the differentiator is a signal indicative of the manifold pressure decreasing at a rate slower than said predeterminable rate; and a switch cooperating with said differentiator responsive to said first and second differentiated signals operative to produce said first raTe of change signal when the manifold pressure is decreasing at a rate faster than said predeterminable rate and operative to produce said second rate of change signal when the manifold pressure is decreasing at a rate slower than said predeterminable rate.

Claim 7

The system as claimed in claim 5 wherein said first manifold pressure reference circuit comprises: a transistor; a resistance in series with said transistor; and a voltage divider means connected to said transistor operative to control a current flow through said transistor, and said series resistance, said current operative to develop a reference voltage across said resistance, said reference voltage being an electrical signal indicative of a manifold pressure greater than the manifold pressure with the engine operating at curb idle speed; and said second manifold pressure reference signal circuit comprises: a transistor; a resistance in series with said transistor; and a voltage divider means connected to said transistor operative to control a current flow through said transistor and said series resistance, said current operative to develop a reference voltage across said resistance, said reference voltage being a signal indicative of a manifold pressure lower than the manifold pressure with the engine operating at curb idle speed.

Claim 8

The system as claimed in claim 6 wherein said signal generated by the first manifold pressure reference signal generating circuit is a signal indicative of a manifold pressure 50 torr greater than the manifold pressure with the engine operating at said curb idle speed; and said signal generated by the second manifold pressure reference signal generating circuit is a signal indicative of a manifold pressure 50 torr lower than the manifold pressure with the engine operating at said curb idle speed.

Claim 9

The system as claimed in claim 5 wherein said set and reset circuits are AND logic gates operative to produce output signals in response to simultaneous input signals from a plurality of preceding signal sources.

Claim 10

The system as claimed in claim 5 wherein said output switch is a bistable multivibrator, switchable from one state to the other, operative in response to a signal from said set switch to generate an inhibit signal; and said multivibrator operative to remain in said inhibit signal generating state until switched to the initial state by a signal from said reset switch, whereby the fuel delivery to the engine is terminated during the deceleration period and normal fuel delivery is restored after the engine operating conditions return to a normal operating range at the end of the deceleration period.

Claim 11

The system as claimed in claim 5 wherein said output switch comprises: a bistable multivibrator, switchable from one state to the other, operative to produce an inhibitory signal in response to a signal from said set switch and said multivibrator operative to remain in said signal producing state until switched to its initial state by a signal from said reset switch; and a pulse terminating switch responsive to the inhibit signal from said multivibrator and signals from the fuel control computer, operative to systematically terminate from each set of fuel injection signals generated by the fuel control computer, at least one fuel injection signal, whereby fuel delivery to the engine is reduced by the intermittent operation of the fuel injector valve in response to the intermittent signals received from the fuel control computer during the deceleration period, and to restore normal fuel delivery to the engine after engine operating conditions return to the normal state at the end of the deceleration period.

Claim 12

The system as claimed in claim 5 wherein said output switch comprises: a bistable multivibrator, switchable from one state to the other, operative to produce an inhibit signal in response to signals from said set switch and said multivibrator operative to remain in said sigNal producing state until switched to its initial state by a signal from said reset switch; and a pulse delay circuit, responsive to an inhibit signal from the multivibrator, signals from the fuel control computer, and signals from the engine sensors, operative to reduce the length of the fuel injection signals generated by the fuel control computer, whereby the fuel delivery to the engine is reduced during the deceleration period and normal fuel delivery to the engine is restored after the engine operating conditions return to a normal state of operation at the end of the deceleration period. 12 The system as claimed in claim 5 wherein said sensor means includes an engine speed sensor operative to produce a signal indicative of engine speed, said means for generating an inhibit signal includes: a speed reference circuit operative to generate an electrical signal indicative of a predeterminable engine speed; a speed comparator responsive to signals from said speed reference circuit and engine speed sensor, operative to generate a signal in response to the signals from the engine speed sensor indicative of an engine speed greater than said predeterminable speed established by the speed reference circuit; and said set switch further operative to produce a signal in response to the coincidence of signals from the first comparator circuit indicating the manifold pressure is greater than said first reference signal, the speed comparator indicating an engine speed greater than said predeterminable speed, and the time rate of change detector indicating the pressure in the manifold is decreasing at a rate faster than said predeterminable rate.

Claim 13

The system as claimed in claim 12 wherein said speed reference circuit comprises: a transistor, a resistance in series with said transistor, and a voltage divider means connected to said transistor operative to control a current flow through said transistor and said series resistance, said current operative to develop a reference voltage across said resistance, said voltage being a signal indicative of an engine speed greater than the curb idle speed of the engine.

Claim 14

The system as claimed in claim 12 wherein said speed comparator circuit comprises: a first transistor means having a pair of states responsive to signals from the engine speed sensor, operative to be in a first state during the occurrence of a pulse signal from the engine speed sensor and operative to be in a second state during the interpulse period; a capacitive means responsive to said first transistor means operative to discharge when said first transistor means is in the first state, and operative to recharge when said first transistor means is in the said second state; and a second switch means having a pair of states responsive to said capacitance means operative to switch between states when the potential across said capacitance means during the recharge interpulse period becomes greater than a preselected value, said preselected value being said potential generated by the engine speed reference circuit.

Claim 15

The system as claimed in claim 12 wherein said output switch is a bistable multivibrator switchable from one state to the other operative to generate an inhibit signal in response to signals from said set switch and said multivibrator operative to remain in said inhibit signal generating state until switched to the initial state by a signal from said reset switch, whereby the fuel delivery to the engine is terminated during the deceleration period and normal fuel delivery is restored after the engine operating parameters return to a normal operating range at the end of the deceleration period.

Claim 16

The system as claimed in claim 12 wherein said output switch comprises: A bistable multivibrator, switchable from one state to the other, operative in response to a signal from said set switch to produce an inhibit signal, and said multivibrator operative to remain in said signal producing state until switched to its initial state by a signal from said reset switch; and a pulse terminating switch responsive to the inhibitory signal from said multivibrator and signals from the fuel control computer operative to systematically terminate from each set of fuel injection signals generated by the fuel control computer at least one fuel injection signal, whereby fuel delivery to the engine is reduced by the intermittent operation of the fuel injection valves in response to the intermittent signals from the fuel control computer during the deceleration period and restore to the engine after operating parameters return to the normal operating state at the end of the deceleration period.

Claim 17

The system as claimed in claim 12 wherein said output switch comprises: a bistable multivibrator, switchable from one stage to the other, operative to produce an inhibitory signal in response to a signal from said set switch and said multivibrator operative to remain in said signal producing state until switched to its initial state by a signal from said reset switch; and a pulse delay circuit responsive to the inhibit signal from the multivibrator, signals from the fuel control computer, and signals from the engine sensors operative to reduce the length of the fuel injection signals generated by the fuel control computer, whereby fuel delivery to the engine is reduced during the deceleration period and normal fuel delivery to the engine is restored after the engine operating parameters return to the normal operating state at the end of the deceleration period.

Claim 18

A deceleration control operative to control the output signals from a fuel control computer for an internal combustion engine having sensor means including a manifold pressure sensor generating signals indicative of the engine''s operating conditions, comprising: first signal generating means responsive to pressure dependent signals operative to generate a first signal when the manifold pressure is higher than a first predeterminable pressure; second signal generating means responsive to pressure dependent signals operative to generate a second signal when the mainfold pressure is higher than a second predeterminable pressure; a time rate of change detector responsive to pressure dependent signals from the manifold pressure sensor operative to produce a first rate of change signal indicative of a manifold pressure decreasing at a rate faster than a predeterminable rate and further operative to produce a second rate of change signal indicative of the manifold pressure decreasing at a rate slower than said predeterminable rate; a control switch responsive to said first signal from said first signal generating means and said first rate of change signal generated by said time rate of change detector operative to generate an inhibitory signal which controls the operation of the engine fuel control computer and regulates the fuel delivery to the engine and further responsive to said second signal generated by said second signal generating means and said second rate of change signal generated by said time rate of change detector operative to terminate said inhibitory signal and restore fuel delivery to the engine.

Claim 19

A deceleration control operative to control the output signals from a fuel control computer for an internal combustion engine having sensor means including a manifold pressure sensor generating signals indicative of the engine''s operating conditions, comprising: first signal generating means responsive to pressure dependent signals operative to generate a first signal when the manifold pressure is higher than a first predeterminable pressure; second signal generating means responsive to pressure dependent signals operative to generate a second signal when the mainfold pressure is higher than a second predeterminable pressure; a time rate of change detector responsive to pressure dependent signals from the manifold pressure sensor operative to produce a first rate of change signal indicative of a manifold pressure decreasing at a rate faster than a predeterminable rate and further operative to produce a second rate of change signal indicative of the manifold pressure decreasing at a rate slower than said predeterminable rate; a control switch responsive to said first signal from said first signal generating means and said first rate of change signal generated by said time rate of change detector operative to generate an inhibitory signal which controls the operation of the engine fuel control computer and regulates the fuel delivery to the engine and further responsive to said second signal generated by said second signal generating means and said second rate of change signal generated by said time rate of change detector operative to terminate said inhibitory signal and restore fuel delivery to the engine.

Claim 20

The deceleration control as claimed in claim 18 wherein said time rate of change detector comprises: an input differentiator circuit and a switch responsive to the pressure dependent signals from the manifold pressure sensor indicative of a changing pressure operative to produce said first rate of change signal in response to an input signal indicative of a manifold pressure decreasing at a rate faster than said predeterminable rate and operative to produce said second rate of change signal indicative of pressure decreasing at a rate slower than said predeterminable rate.

Claim 21

The deceleration control as claimed in claim 19 wherein said first signal generating means comprises: a first manifold pressure reference circuit operative to generate on a first reference eLectrical signal indicative of a first predeterminable pressure; a first comparator circuit responsive to signals from said first manifold pressure reference circuit and the signal from the manifold pressure sensor operative to produce a signal when the signal from the manifold pressure sensor is indicative of a pressure greater than the signal generated by said first manifold pressure reference circuit; and wherein said second signal generating means comprises: a second manifold pressure reference circuit operative to generate a second reference electrical signal indicative of a second predeterminable pressure; and a second comparator circuit, responsive to signals from said second manifold pressure reference circuit and signals from the manifold pressure sensor operative to produce a signal when the signal from the pressure sensor is indicative of a pressure higher than the signal generated by said second manifold pressure reference circuit.

Claim 22

The deceleration control as claimed in claim 20 wherein said control switch comprises: a set switch operative to produce a signal in response to the coincidence of signals from said first comparator, indicating a manifold pressure greater than said first reference signal, and said first signal from the time rate of change detector, indicating the pressure in the manifold is decreasing at a rate faster than said predeterminable rate; a reset switch operative to produce a signal in response to the coincidence of signals from the second comparator, indicating a manifold pressure greater than said second reference signal, and the time rate of change detector, indicating the pressure in the manifold is decreasing at a rate slower than said predeterminable rate; and an output switch switchable from one state to the other in response to signals from said set and reset switches operative to generate said inhibit signal.

Claim 23

The deceleration control as claimed in claim 21 wherein said output switch comprises a bistable multivibrator, switchable from one state to the other, operative to generate said inhibit signal in response to a signal from said set switch; and said multivibrator operative to remain in said inhibit signal generating state until switched to its initial state by a signal from said reset switch,.

Claim 24

The deceleration control as claimed in claim 21 further comprising: a speed reference circuit operative to generate an electrical signal indicative of a predeterminable engine speed; a speed comparator, responsive to signals from said speed reference circuit and engine speed sensor operative to generate a signal in response to signals from the engine speed sensor indicative of an engine speed greater than said predeterminable speed established by said speed reference circuit; and said set switch, further operative to produce a signal in response to the coincidence of signals from said first comparator, indicating the manifold pressure is greater than said first reference signal, said speed comparator, indicating an engine speed greater than said predeterminable speed, and said time rate of change detector, indicating the pressure in the engine manifold is decreasing at a rate faster than said predeterminable rate.

Claim 25

The deceleration control as claimed in claim 23 wherein said output switch comprises: a bistable multivibrator, switchable from one state to the other, operative to generate said inhibit signal in response to said signal from said set switch and said multivibrator operative to remain in said inhibit signal generating state until switched to the initial state by a signal from said reset switch.

Claim 26

A deceleration control operative to control the output signals from a fuel control computer for an internal combustion engine having sensor means generating signals indicative of the engine''s operating condition, wherein said sensor means includes at least one sensor generating signal having a static component indicative of the magnitude of the sIgnal generated by said at least one sensor at any given time, and one dynamic component indicative of the rate of change of the signal generated by the at least one sensor as a function of time, comprising: means responsive to the static component of the signal from just one of said at least one sensor for generating condition signals indicative of at least one predetermined engine operating condition; means responsive to the dynamic component of the signal from the same just one of said at least one sensor for generating rate of change signals indicative of at least two different rates of change in the operating conditions of the engine, a first rate of change signal indicative of the presence of a deceleration condition, and a second rate of change signal indicative of the absence of said deceleration condition; and means responsive to said condition signals and said first rate of change signal for determining a demand for deceleration and for generating an inhibitory signal controlling the operation of the fuel control computer to curtail fuel delivery to the engine during the period of deceleration, and further responsive to said condition signal and said second rate of change signal for determining the end of said demand for deceleration and terminating said inhibitory signal.

Claim 27

A deceleration control operative to control the output signals from a fuel control computer for an internal combustion engine having sensor means generating signals indicative of the engine''s operating condition, wherein said sensor means includes at least one sensor generating signal having a static component indicative of the magnitude of the sIgnal generated by said at least one sensor at any given time, and one dynamic component indicative of the rate of change of the signal generated by the at least one sensor as a function of time, comprising: means responsive to the static component of the signal from just one of said at least one sensor for generating condition signals indicative of at least one predetermined engine operating condition; means responsive to the dynamic component of the signal from the same just one of said at least one sensor for generating rate of change signals indicative of at least two different rates of change in the operating conditions of the engine, a first rate of change signal indicative of the presence of a deceleration condition, and a second rate of change signal indicative of the absence of said deceleration condition; and means responsive to said condition signals and said first rate of change signal for determining a demand for deceleration and for generating an inhibitory signal controlling the operation of the fuel control computer to curtail fuel delivery to the engine during the period of deceleration, and further responsive to said condition signal and said second rate of change signal for determining the end of said demand for deceleration and terminating said inhibitory signal.

Claim 28

The deceleration control of claim 25 wherein said means for generating condition signals generates two condition signals indicative of two different engine operating conditions, a first condition signal determinative that the engine operating conditions are such that fuel delivery to the engine should be curtailed during deceleration and a second condition signal determinative that the engine''s operating conditions approximate the curb idle operating condition.