Fuel injection system for an internal combustion engine

Claim 2

A fuel injection system for an internal combustion engine as recited in claim 2 wherein said means operative responsive to operation of said first and second switch means for generating said first voltage is a first ramp voltage generator, means for initiating operation of said first ramp voltage generator responsive to operation of said first switch means, means for stopping operation of said first ramp voltage generator responsive to operation of said second switch means, said means for converting said resultant voltage to a first control signal includes a second ramp voltage generator, means for initiating operation of said second ramp voltage generator responsive to operation of said first switch means, and comparator means for comparing said resultant voltage amplitude with said second ramp voltage amplitude and providing a first control signal as an output when the amplitudes are equal.

Claim 3

A fuel injection system as recited in claim 1 wherein there is included means for disabling said first means during engine startup time, and means operative upon engine startup and responsive to the temperature of said engine for delaying the application of said second control signal to said means for operating said electroexpansive pump by an interval required to compensate for the effects of said engine temperature.

Claim 4

A fuel injection system as recited in claim 3 wherein there is inclined a third switch means operative responsive to said cam driven means following operation of said second switch means for resetting said first and second ramp voltage generators.

Claim 5

A fuel injection system as recited in claim 1 wherein said second means operated responsive to said engine for generating a second control signal timed for and representative of a main fuel injection for each cylinder includes a switch means for and associated with each cylinder, a cam means driven responsive to said motor for successively operating each switch means, and means operated responsive to operation of each said switch means for generating a second control signal for the associated cylinder.

Claim 6

A fuel injection system as recited in claim 6 wherein said first means operated responsive to said engine for generating a first control signal timed for and representative of a pilot fuel injection for each cylinder includes a first ramp voltage generator, means for initiating operation of said first ramp voltage generator responsive to operation of a first of said switch means, means for terminating operation of said main ramp voltage generator responsive to operation of a second of said switch means, a second ramp voltage generator for and associated with each cylinder, means for initiating operation of each said second ramp voltage generator responsive to the operation of a switch means associated with a preceding cylinder, means for resetting each second rAmp voltage generator responsive to the operation of a switch means associated with the same cylinder as said second ramp voltage generator, means for generating an engine constant voltage having an amplitude representative of a desired leadtime for pilot fuel injection over main fuel injection, means for subtracting said main ramp voltage generator output voltage from said motor constant voltage to provide a voltage difference signal, and comparator means for each cylinder for comparing the amplitude of said voltage difference signal with the output of each said second ramp voltage generator and generating a first control signal for the cylinder when said amplitudes are substantially equal.

Claim 7

A fuel injection system as recited in claim 7 including switch means operative responsive to engine startup for preventing application of the first control signal to each serial means for operating said electroexpansive pump for each cylinder during engine startup time.

Claim 8

A fuel injection system as recited in claim 7 wherein said means for generating an engine constant voltage includes means for generating a first voltage responsive to engine temperature, a second means for generating a second voltage responsive to fuel cetane number, means for generating a third voltage responsive to engine constants and means for combining said first, second and third voltages to produce said engine constant voltage.

Claim 9

A fuel injection system as recited in claim 6 wherein each said first means operated responsive to said engine for generating a first controlled signal timed for and representative of a pilot fuel injection for each cylinder, includes: OR gate means to the input of which each of said second control signals are applied, a first delay circuit, a second delay circuit having its input connected to the first delay circuit output and having a longer delay time than said first delay circuit, a sample and hold circuit, means for connecting the output of said OR gate means to the sample and hold circuit to enable it to sample and hold a voltage signal applied to its input in response to a pulse signal received from said OR gate, means for connecting said OR gate means output to said first time delay circuit input, a ramp generator, means for applying said first delay circuit output to said ramp generator to reset said ramp generator, means for applying said second delay circuit output to said ramp generator input to initiate operation of said ramp generator, means for applying the output of said ramp generator to said sample and hold circuit input, means for generating a motor constant voltage having an amplitude representative of a desired pilot fuel injection leadtime, means for subtracting said motor constant voltage from the voltage of said sample and hold circuit to provide a resultant voltage, means for comparing said resultant voltage with said ramp generator voltage and providing a first control signal when they are substantially equal, and means for directing said first control signal to a selected one of said means for operating an electroexpansive pump responsive to a first control signal for a cylinder.

Claim 10

A fuel injection system as recited in claim 10 wherein said means for directing said first control signal to a selected one of said means for operating an electroexpansive pump responsive to a first control signal for a cylinder includes: a two input AND gate for each of said cylinders each AND gate having its output connected to one of said means for operating an electroexpansive pump, means applying said first control signal to one input of all of said AND gates, and means operative responsive to each said switch means for applying an enabling signal to a selected one of said AND gates second inputs.

Claim 11

A fuel injection system as recited in claim 10 wherein there is provided switch means operative responsive to startup operation of said engine For preventing application of said pilot fuel injection signals to said electroexpansive fuel pumps.

Claim 12

A fuel injection system as recited in claim 2 wherein there is included a governing means operative responsive to operation of said second switch means for limiting the fuel injected into the cylinders of said engine to provide a speed and smoke emission governing device.

Claim 13

A fuel injection system as recited in claim 13 wherein said governing means includes tachometer means responsive to the operation of said second switch means for providing an output signal having an amplitude representative of the speed of said engine: means for establishing a speed voltage having an amplitude representative of a desired maximum speed, means for comparing the output of said tachometer means and said speed voltage to provide a resultant signal, and means responsive to said resultant signal to limit the amount of fuel injected into said engine cylinders to thereby limit said engine speed.

Claim 14

A fuel injection system as recited in claim 13 wherein there is included programmable filter means to which the output of said tachometer is applied for producing an output signal for establishing the maximum amount of fuel for a given engine speed which will not cause smoking, and means for applying said output signal to each said electroexpansive pump.

Claim 15

A fuel injection system as recited in claim 15 wherein there is included a manual means for independently controlling the quantity of fuel injected in each of two or more discrete injection periods per engine cycle, and manual means for independently controlling the duration of fuel injection for two or more discrete injection periods per engine cycle.

Claim 16

A fuel injection system as recited in claim 15 wherein there are included means for sensing engine temperature, and delay means for delaying the application by said means for applying each main fuel injection to cause said injection to occur close to top dead center for a relatively cold engine than for a relatively warm engine.

Claim 17

A fuel injection system as recited in claim 1 wherein there is included means for disabling said first means during engine startup time: means operative upon engine startup and responsive to the temperature of said engine for delaying the application of said second control signal to said means for operating said electroexpansive pump by an interval required to compensate for the effects of said engine temperature, and means operative upon engine startup and responsive to the temperature of said engine for applying a plurality of second control signals in sequence and during an engine cycle to assist the cold starting of the engine.

Claim 18

A fuel injection system for an internal combustion engine of the compression ignition type comprising: an electroexpansive fuel injection pump for each cylinder of said engine, a first ramp voltage generator, a second ramp voltage generator for each cylinder of said engine, a plurality of switch means, a different one of said plurality being assigned to a different one of said cylinders, engine driven cam means for sequentially and successively operating each of said switch means, means for initiating operation of said first ramp voltage generator responsive to operation of a last of said plurality of switch means, means for terminating operation of said first ramp voltage generator responsive to operation of a first of said plurality of switch means, means for resetting said first ramp voltage generator responsive to operation of a second of said plurality of switch means, means responsive to operation of a switch means for initiating operation of the second ramp generator assigned to the engine cylinder succeeding the one to which the switch means which has been operated is assigned, means responsive to the operation of the switch means assigned to the same cylinder as that assigned to the operated second ramp generator to reset the second ramp generator, means for generating an engine constant voltage having an amplitude representative of a desired leadtime for a pilot fuel injection before a main fuel injection into a cylinder, means for subtracting said first ramp voltage generator output voltage at the time its operation is terminated from said engine constant voltage to provide a resultant voltage, comparator means for each cylinder for comparing said resultant voltage with the output of the second ramp generator for each cylinder and providing a pilot injection pulse signal when they have substantially the same amplitude, means for operating the electroexpansive fuel pump of each cylinder responsive to the pilot injection pulse signal output of the comparator means for that cylinder, to provide a pilot fuel injection, means for generating a main injection pulse signal for each cylinder responsive to operation of the switch means for that cylinder, and means for operating the electroexpansive fuel pump of each cylinder responsive to the main injection pulse signal from the switch means associated with that cylinder to provide a main fuel injection.

Claim 19

A fuel injection system for an internal combustion engine of the compression ignition type comprising: an electroexpansive fuel injection pump for each cylinder of said engine, a plurality of switch means, a different one of which is assigned to a different one of said engine cylinders, each switch means having a first and second contact and swinger means for making connection with either said first or said second contact, engine driven cam means for sequentially operating the swinger means of a switch means to its first contact and the swinger means of the succeeding switch means to its second contact, a ramp voltage generator, means responsive to the operation of a swinger means to a first contact for generating a first pulse, sample and hold means responsive to said first pulse to sample and hold the output of said ramp voltage generator, first time delay means for resetting the ramp generator responsive to a first pulse after a first predetermined time delay, second time delay means for initiating operation of said ramp generator responsive to the output of said first time delay means after a second predetermined time delay, means for establishing an engine constant voltage having an amplitude representative of a desired leadtime for a pilot fuel injection before a main fuel injection into a cylinder, means for subtracting said engine constant voltage from the output of said sample and hold circuit and providing a resultant voltage, comparing means for comparing the output of said ramp voltage generator with said resultant voltage and providing a pilot lead pulse signal output when the amplitudes are substantially the same, means for generating a steering pulse responsive to a switch means swinger operated to a second contact, means responsive to a steering pulse and a pilot lead pulse signal for causing the electroexpansive pump for the cylinder associated with the switch means whose swinger is connected to the second contact to provide a pilot fuel injection, means responsive to a first pulse generated when the said switch means swinger is next operated to its first contact for causing the electroexpansive pump for the cylinder associated with the said switch means to provide a main fuel injection pulse.