Fuel injection control system

Claim 2

In combination with an internal combustion engine fuel injection control system of the type having a control circuit to electrically control the open time of at least one fuel injection valve in response ro the rotation of an engine crank shaft, the improvement wherein said control circuit comprises: means for generating a first pulse train which produces at least one pulse for each revolution of the engine crank shaft, said first pulse train having pulses which begin at an initial point and then increase at a controllable rate; means for varying the magnitude of the initial point at which each of said pulses of said first pulse train begin; means for generating a second pulse train having pulse durations which begin when a pulse from said first pulse train is initiated and end when a pulse from said first pulse train reaches a value established by a sensed engine operating parameter; and means for applying the pulses of said second pulse train to the fuel injector valve to open the valve for the duration of a pulse of said second pulse train.

Claim 3

The combination as recited in claim 1 wherein the means for varying the magnitude of said initial point at which each of said pulses of said first pulse train begins comprises: a ramp generator which establishes a locus of points at which the pulses of said first pulse train are capable of beginning; and means for delaying the generation of said ramp for a predetermined time interval.

Claim 4

In combination with an internal combustion engine fuel injection control system of the type having a control circuit to electrically control the open time of at least one fuel injection valve in response to the rotation of an engine crank shaft, the improvement wherein said control circuit comprises: means for generating a first pulse train which produces a pulse for each revolution of the engine crank shaft, said first pulse train having pulses whose magnitudes vary in a predetermined manner; means for generating a second pulse train which produces a pulse for each revolution of the engine crank shaft out of phase by a known phase differential with the pulses of said first pulse train, said second pulse train having pulses whose magnitudes increase at a predetermined rate; means for combining the pulses of said first and second pulse trains so that the beginning of a pulse from said second pulse train terminates a pulse from said first pulse train and the end of a pulse from said second pulse train initiates a pulse from said first pulse train; means for generating a third pulse train having pulses which begin when a pulse from said second pulse train begins and end when a pulse from said second pulse train reaches a predeterminable value; means for applying said third pulse train to the fuel injection valve to open the valve for the duration of a pulse from said third pulse train.

Claim 5

In combination with an internal combustion engine fuel injection control system of the type having a control circuit to electrically control the open time of at least one fuel injection valve in response to the rotation of an engine crank shaft, the improvement wherein said control circuit comprises: means for generating a first pulse train which produces a pulse for each revolution of the engine crank shaft, said first pulse train having pulses whose magnitudes vary in a predetermined manner; means for generating a second pulse train which produces a pulse for each revolution of the engine crank shaft out of phase by a known phase differential with the pulses of said first pulse train, said second pulse train having pulses whose magnitudes increase at a predetermined rate; means for combining the pulses of said first and second pulse trains so that the beginning of a pulse from said second pulse train terminates a pulse from said first pulse train and the end of a pulse from said second pulse train initiates a pulse from said first pulse train; means for generating a third pulse train having pulses which begin when a pulse from said second pulse train begins and end when a pulse from said second pulse train reaches a predeterminable value; means for applying said third pulse train to the fuel injection valve to open the valve for the duration of a pulse from said third pulse train.

Claim 6

The combination as recited in claim 3 wherein said means for generating a third pulse train includes: means for generating a signal which is a function of an operating parameter of the engine to establish said predeterminable value which when reached by each of said pulse of said second pulse train, terminates a third pulse train pulses.

Claim 7

The combination as recited in claim 4 wherein the duration of a pulse of said first and second pulse train is equal to the time required for the said engine to complete one engine cycle.

Claim 8

In an internal combustion engine fuel control system of the type having triggering means operative to generate triggering signals indicative of the occurrence of engine triggering events, a computing means comprising: at least two current source means operative to generate first and second electrical currents having predeterminable magnitudes; network means, having at least one storage member, for receiving said currents and storing electrical signals in response thereto; first switching means for sequentially applying said currents to said at least one storage member in response to the triggering signals, said first current being applied to said at least one storage member for a period of time immediately following a first triggering signal and said second current being applied to said at least one storage member in response to a selected succeeding triggering signal; and threshold means coupled to said network means responsive to the electrical signal stored therein operative to generate a signal for the period of time following the selected succeeding triggering signal that the stored electrical signal maintains a selected relationship to a threshold value.

Claim 9

In an internal combustion engine fuel control system of the type having triggering means operative to generate triggering signals indicative of the occurrence of engine triggering events, a computing means comprising: at least two current source means operative to generate first and second electrical currents having predeterminable magnitudes; network means, having at least one storage member, for receiving said currents and storing electrical signals in response thereto; first switching means for sequentially applying said currents to said at least one storage member in response to the triggering signals, said first current being applied to said at least one storage member for a period of time immediately following a first triggering signal and said second current being applied to said at least one storage member in response to a selected succeeding triggering signal; and threshold means coupled to said network means responsive to the electrical signal stored therein operative to generate a signal for the period of time following the selected succeeding triggering signal that the stored electrical signal maintains a selected relationship to a threshold value.

Claim 10

The system as claimed in claim 6 wherein said network means comprise: at least two capacitive members and said first switching means are operative to alternating apply each of said first and second currents to said two capacitive members whereby the charge acCumulated on said capacitive members will be a function of the duration of application of each of said first and second currents.

Claim 11

The system as claimed in claim 7 wherein said second current can charge either of said at least two capacitors to a higher voltage.

Claim 12

The system as claimed in claim 7 wherein said at least two capacitors are substantially equal.

Claim 13

The system as claimed in claim 6 including further second switching means responsive to a first triggering event operative to controllably limit the maximum value of electrical signal stored by said storage member.

Claim 14

The system as claimed in claim 10 wherein said second switching means further include means responsive to the time elapsed from said first triggering signal operative to controllably vary the limit established by said second switching means.

Claim 15

The system as claimed by claim 10 wherein the limit value of stored electrical signal is removed upon the occurrence of the selected succeeding triggering event.

Claim 16

In combination with an internal combustion engine fuel injection control system of the type having a control circuit to electrically control the open time of an electromagnetically operated fuel injection valve in response to the rotation of said engine crank shaft, the improvement wherein said control circuit comprises: means for generating a first pulse train which produces a pulse for each revolution of said engine crank shaft, said first pulse train having pulses which begin at an initial point and then increase at a constant rate which rate is the same for each of said pulses; means for varying the magnitude of the initial point at which each of said pulses of said first pulse train begin; means for generating a second pulse train having pulse durations which begin when a pulse from said first pulse train is initiated and end when a pulse from said first pulse train reaches a predetermined value established by a sensed engine operating parameter; and means for applying the pulses of said second pulse train to said electromagnetically operated fuel injector valve to open said valve for the duration of each pulse of said second pulse train.

Claim 17

In combination with an internal combustion engine fuel injection control system of the type having a control circuit to electrically control the open time of an electromagnetically operated fuel injection valve in response to the rotation of said engine crank shaft, the improvement wherein said control circuit comprises: means for generating a first pulse train which produces a pulse for each revolution of said engine crank shaft, said first pulse train having pulses which begin at an initial point and then increase at a constant rate which rate is the same for each of said pulses; means for varying the magnitude of the initial point at which each of said pulses of said first pulse train begin; means for generating a second pulse train having pulse durations which begin when a pulse from said first pulse train is initiated and end when a pulse from said first pulse train reaches a predetermined value established by a sensed engine operating parameter; and means for applying the pulses of said second pulse train to said electromagnetically operated fuel injector valve to open said valve for the duration of each pulse of said second pulse train.

Claim 18

In combination with an internal combustion engine fuel injection control system of the type having a control circuit to electrically control the open time of an electromagnetically operated fuel injection valve in response to the rotation of said engine crank shaft, the improvement wherein said control circuit comprises: means for generating a first pulse train which produces a pulse for each revolution of said engine crank shaft, said first pulse train having pulses whose magnitudes vary in a predetermined manner; means for generating a second pulse train which produces a pulse for each revolution of said engine crank shaft 180* out of phase with the pulses of said first pulse train, said second pulse train having pulses whose magnitudes increase at a constant rate for all pulse durations; means for combining the pulses of said first and second pulse trains so that the beginning of a pulse from said second pulse train terminates a pulse from said first pulse train and the end of a pulse from said second pulse train initiates a pulse from said first pulse train; means for generating a third pulse train having pulses which begin when a pulse from said second pulse train begins and ends when a pulse from said second pulse train reaches a predetermined value; and means for applying said third pulse train to said electromagnetically operated fuel injection valve to open said injector valve for the duration of each pulse from said third pulse train.

Claim 19

In combination with an internal combustion engine fuel injection control system of the type having a control circuit to electrically control the open time of an electromagnetically operated fuel injection valve in response to the rotation of said engine crank shaft, the improvement wherein said control circuit comprises: means for generating a first pulse train which produces a pulse for each revolution of said engine crank shaft, said first pulse train having pulses whose magnitudes vary in a predetermined manner; means for generating a second pulse train which produces a pulse for each revolution of said engine crank shaft 180* out of phase with the pulses of said first pulse train, said second pulse train having pulses whose magnitudes increase at a constant rate for all pulse durations; means for combining the pulses of said first and second pulse trains so that the beginning of a pulse from said second pulse train terminates a pulse from said first pulse train and the end of a pulse from said second pulse train initiates a pulse from said first pulse train; means for generating a third pulse train having pulses which begin when a pulse from said second pulse train begins and ends when a pulse from said second pulse train reaches a predetermined value; and means for applying said third pulse train to said electromagnetically operated fuel injection valve to open said injector valve for the duration of each pulse from said third pulse train.

Claim 20

A fuel injection control system responsive to at least two variable operating characteristics of an internal combustion engine for controlling the provision of fuel to said engine comprising: means responsive to one of the variable operating characteristics for generating a threshold signal having a value determined by the vaLue of said one variable operating characteristic; means for generating a cyclic signal having a value that varies at a predetermined rate from an initial value to the threshold value at least once during each cycle of engine operation; and means responsive to the other variable operating characteristic for changing said initial value, a change in either the initial or threshold value thereby changing the time required for the cyclic signal to reach the threshold value by an amount that is independent of the magnitude of the other of said values; fuel delivery means responsive to said cyclic signal for providing fuel to the engine for a period in each engine cycle determined by the time required for said cyclic signal to vary from said initial value to said threshold value.

Claim 21

A fuel injection control system responsive to at least two variable operating characteristics of an internal combustion engine for controlling the provision of fuel to said engine comprising: means responsive to one of the variable operating characteristics for generating a threshold signal having a value determined by the vaLue of said one variable operating characteristic; means for generating a cyclic signal having a value that varies at a predetermined rate from an initial value to the threshold value at least once during each cycle of engine operation; and means responsive to the other variable operating characteristic for changing said initial value, a change in either the initial or threshold value thereby changing the time required for the cyclic signal to reach the threshold value by an amount that is independent of the magnitude of the other of said values; fuel delivery means responsive to said cyclic signal for providing fuel to the engine for a period in each engine cycle determined by the time required for said cyclic signal to vary from said initial value to said threshold value.

Claim 22

The control system of claim 15 in which: said threshold signal generating means comprise means responsive to engine air consumption; and said means for changing said initial value comprise means responsive to engine speed.

Claim 23

The control system of claim 15 in which said means for generating a cyclic signal comprises means for generating a signal that varies at a fixed rate, a change in either one of said initial or threshold values thereby changing the period of fuel injection by the same amount for all levels of the other of said initial or threshold values.

Claim 24

The control system of claim 15 in which said means for generating said cyclic signal comprise: means for receiving and storing electric signals; a first current source for charging said receiving and storing means to the threshold value; and means for discharging said receiving and storing means at least once for each engine cycle, the charging of said receiving and storing means to said threshold by said first current source comprising said cyclic signal.

Claim 25

The control system of claim 18 in which said means for changing said initial value comprise means responsive to engine speed, and include: a second current source for charging said receiving and storing means at a predetermined rate independent of engine speed and different from the charging rate provided by current from said first source; and switching means for connecting said second current source with said receiving and storing means for only a predetermined portion of each engine cycle and thereafter connecting said first source with said receiving and storing means, the time during which said second source charges said receiving and storing means and thus the value of the summed signal upon initiation of the charging of said receiving and storing means by said first source thereby being determined by engine speed.

Claim 26

The control system of claim 19 further including means for preventing the charging of said receiving and storing means during a predetermined portion of each engine cycle to cause variations in engine speed falling within a predetermined range to produce no change in said initial value.