Control device for fuel supply in internal combustion engines

Claim 2

A control circuit for controlling the supply of fuel in an internal combustion engine, including a solenoid valve for controlling the amount of fuel to be supplied to the internal combustion engine through the flow of current through the electromagnetic winding of said solenoid valve, one side of said winding being connected to a source of supply voltage over a predetermined period of time, said circuit comprising: an input terminal for supplying a control signal having a prescribed duration extending from a first portion for initiating the flow of current through said winding to a second portion for terminating the flow of current through said winding, the duration of said current flow through said winding controlling the length of time that said solenoid valve is energized, to thereby effect the supply of fuel to said engine over said predetermined period of time; switching means, coupled between said input terminal and said winding, for switching into said winding a current from said source of supply voltage in response to said control signal, the amplitude of said control signal over said prescribed duration being sufficient to energize said switching means; and means, coupled to said switching means, for substantially shortening any delay time existing between the flow and cut-off of current of a sufficient magnitude to energize said winding, so as to effect the supply of fuel to said engine, including circuit means for supplying a substantially large current to said winding in response to said first portion of said control signal, so as to energize said valve winding to open said valve, and for reducing the counter-electromotive force in said winding upon the occurrence of said second portion of said control signal and for maintaining the supply of current of a sufficient magnitude to keep said winding energized prior to said second portion of said control signal, wherein said switching means comprises a first transistor, a first electrode of which is resistively connected to said solenoid winding, a second electrode of which is connected to a reference potential and a third electrode of which is resistively connected to said input terminal and wherein said circuit means comprises a capacitor connected in parallel with the resistive connection of one of said electrodes of said first transistor.

Claim 3

A circuit according to claim 1, wherein said circuit means comprises a capacitor connected in parallel with the resistive connection of said first electrode of said first transistor with said solenoid winding.

Claim 4

A circuit according to claim 1, wherein said circuit means comprises a capacitor connected in parallel with a resistive connection of said third electrode of said first transistor with said input terminal.

Claim 5

A circuit according to claim 2, wherein said first electrode of said first transistor is the collector electrode thereof, said second electrode is the emitter electrode thereof, and said third electrode is the base electrode thereof.

Claim 6

A circuit according to claim 3, wherein said first electrode of said first transistor is the collector electrode thereof, said second electrode is the emitter electrode thereof, and said third electrode is the base electrode theReof.

Claim 7

A control circuit for controlling the supply of fuel in an internal combustion engine, including a solenoid valve for controlling the amount of fuel to be supplied to the internal combustion engine through the flow of current through the electromagnetic winding of said solenoid valve, one side of said winding being connected to a source of supply voltage over a predetermined period of time, said circuit comprising: an input terminal for supplying a control signal having a prescribed duration extending from a first portion for initiating the flow of current through said winding to a second portion for terminating the flow of current through said winding, the duration of said current flow through said winding controlling the length of time that said solenoid valve is energized, to thereby effect the supply of fuel to said engine over said predetermined period of time; switching means, coupled between said input terminal and said winding, for switching into said winding a current from said source of supply voltage in response to said control signal, the amplitude of said control signal over said prescribed duration being sufficient to energize said switching means; and means coupled to said switching means for substantially shortening any delay time existing between the flow and cut-off of current of a sufficient magnitude to energize said winding, so as to effect the supply of fuel to said engine, including circuit means for supplying a substantially large current to said winding in response to said first portion of said control signal, so as to energize said valve winding to open said valve, and for reducing the counter-electromotive force in said winding upon the occurrence of said second portion of said control signal and for maintaining the supply of current of a sufficient magnitude to keep said winding energized prior to said second portion of said control signal, wherein said switching means comprises a first transistor, a first electrode of which is resistively connected to said solenoid winding, a second electrode of which is connected to a reference potential and a third electrode of which is resistively connected to said input terminal, wherein said circuit means comprises a second transistor having first and second electrodes thereof connected across the resistive connection between said first electrode of said first transistor and said solenoid winding and a third electrode thereof capacitively coupled to said input terminal.

Claim 8

A control circuit for controlling the supply of fuel in an internal combustion engine, including a solenoid valve for controlling the amount of fuel to be supplied to the internal combustion engine through the flow of current through the electromagnetic winding of said solenoid valve, one side of said winding being connected to a source of supply voltage over a predetermined period of time, said circuit comprising: an input terminal for supplying a control signal having a prescribed duration extending from a first portion for initiating the flow of current through said winding to a second portion for terminating the flow of current through said winding, the duration of said current flow through said winding controlling the length of time that said solenoid valve is energized, to thereby effect the supply of fuel to said engine over said predetermined period of time; switching means, coupled between said input terminal and said winding, for switching into said winding a current from said source of supply voltage in response to said control signal, the amplitude of said control signal over said prescribed duration being sufficient to energize said switching means; and means coupled to said switching means for substantially shortening any delay time existing between the flow and cut-off of current of a sufficient magnitude to energize said winding, so as to effect the supply of fuel to said engine, including circuit means for supplying a substantially large current to said winding in response to said first portion of said control signal, so as to energize said valve winding to open said valve, and for reducing the counter-electromotive force in said winding upon the occurrence of said second portion of said control signal and for maintaining the supply of current of a sufficient magnitude to keep said winding energized prior to said second portion of said control signal, wherein said switching means comprises a first transistor, a first electrode of which is resistively connected to said solenoid winding, a second electrode of which is connected to a reference potential and a third electrode of which is resistively connected to said input terminal, wherein said circuit means comprises a second transistor having first and second electrodes thereof connected across the resistive connection between said first electrode of said first transistor and said solenoid winding and a third electrode thereof capacitively coupled to said input terminal.

Claim 9

A circuit according to claim 6, wherein said circuit means comprises a resistor-capacitor series connection between said third electrode of said second transistor and said input terminal, and a diode connected between a junction of said resistor and capacitor connected in series forming said series connection, and said reference potential.

Claim 10

A circuit according to claim 7, wherein said first, second and third electrodes of said second transistor are the collector, emitter and base electrodes thereof, respectively.