US3513815A - Fuel injection systems for internal combustion engines - Google Patents

Fuel injection systems for internal combustion engines Download PDF

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Publication number
US3513815A
US3513815A US702032A US3513815DA US3513815A US 3513815 A US3513815 A US 3513815A US 702032 A US702032 A US 702032A US 3513815D A US3513815D A US 3513815DA US 3513815 A US3513815 A US 3513815A
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US
United States
Prior art keywords
voltage
injector
supply voltage
fuel
fuel injection
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US702032A
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English (en)
Inventor
Joseph Mair
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Associated Engineering Ltd
AE PLC
ZF International UK Ltd
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Associated Engineering Ltd
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Assigned to LUCAS INDUSTRIES PUBLIC LIMITED COMPANY, GREAT KING STREET, BIRMINGHAM, ENGLAND reassignment LUCAS INDUSTRIES PUBLIC LIMITED COMPANY, GREAT KING STREET, BIRMINGHAM, ENGLAND ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: AE PLC
Assigned to AE PLC reassignment AE PLC ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: ASSOCIATED ENGINEERING LIMITED
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/30—Controlling fuel injection
    • F02D41/3005—Details not otherwise provided for
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/20—Output circuits, e.g. for controlling currents in command coils
    • F02D2041/202—Output circuits, e.g. for controlling currents in command coils characterised by the control of the circuit
    • F02D2041/2031—Control of the current by means of delays or monostable multivibrators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/20—Output circuits, e.g. for controlling currents in command coils
    • F02D2041/2068—Output circuits, e.g. for controlling currents in command coils characterised by the circuit design or special circuit elements
    • F02D2041/2082—Output circuits, e.g. for controlling currents in command coils characterised by the circuit design or special circuit elements the circuit being adapted to distribute current between different actuators or recuperate energy from actuators

Definitions

  • This invention relates to a fuel injection system for internal combustion engines comprising at least one electromagnetically operated fuel injector and a control pulse generator producing pulses for energising said at'least one injector, so that the injector or a injector is opened for a period depending on the duration of each of the pulses to pass fuel to the engine, wherein means are provided for compensating for the effect of supply voltage variations on the time that an injector is open in response to a pulse from the control pulse generator, whereby the fuel delivery from the or each injector is substantially independent of variations in said supply voltage.
  • the present invention relates to fuel injection systems for internal combustion engines and more particularly to improvements in the fuel injection systems such as are described in US. Pats. Nos. 3,240,191 and 3,272,187.
  • Such systems comprise at least one electromagnetically operated fuel injection valve or injector and a control circuit producing pulses for energising said at least one injection valve so that the valve or a valve is open for a period depending on the duration of each of the pulses to pass fuel to the engine.
  • the control circuit is fed with at least one variable voltage which varies as a function of one or more parameters of engine operation and which controls the duration of the pulses produced by the control circuit which are fed to energise the injection valve or valves.
  • the control circuit comprises a monostable multivibrator for producing the electrical pulses and the duration of the pulses is varied by varying two control voltages applied to the timing capacitor circuit of the multivibrator.
  • the two control voltages may be derived from a computer circuit fed with a plurality of signals which respectively vary with variations in different parameters of engine operation.
  • the fuel injection valves are solenoid operated devices and variations in the voltage of the vehicle battery have been shown to cause a variation in the opening time of the valves, and hence produce a variation in fuel delivery through a valve for any chosen pulse duration or width. Therefore the quantity of fuel fed to the engine is no longer solely determined by variations in engine operating parameters, as is desired.
  • the solenoid current builds up to a greater level during the first millisecond as the battery supply voltage increases, with the result that the injector opens more rapidly at increased supply voltages and delivers more fuel for a given pulse duration or width.
  • This reduction in opening time for any given increase in supply voltage is however the same for all pulse durations or widths.
  • means are provided for compensating for the eifect of supply voltage variations on the time that an injector is open in response to a pulse from the control pulse generator, whereby the fuel delivery from the or each injector is substantially independent of variations in said supply voltage.
  • control pulse generator comprises a monostable multivibrator
  • means are provided for varying a bias applied to the monostable multivibrator with changes in battery supply voltage, in order to keep the fuel delivery more nearly constant, as determined by the control parameters, with variations in the battery supply voltage.
  • the bias applied to the monostable multivibrator is derived from a network connected across the voltage supply and according to a feature of the present invention, this network includes a non-linear element such as a saturated diode or a Zener diode.
  • the system basically comprises a control pulse generator 1, a computer 2, a pulse amplifier 3, a distributor 4 and fuel injectors 5, and operates generally in the manner described in Pat. No. 3,272,187.
  • the system is intended for a four cylinder internal combustion engine and a separate fuel injector is provided for each cylinder.
  • the injectors are preferably mounted in the inlet manifold of the engine.
  • the duration of the pulses fed to energise the injectors, via the amplifier 3 and distributor 4, is controlled by the control pulse generator 1, which is in turn controlled by two voltages V1 and V2 derived from the computer 2.
  • the control pulse generator is triggered by pulses at the firing frequency of the engine and the computer 2 is fed with information supplied by a number of transducers, each responsive to one or more conditions of engine operation. Since the injectors are supplied with fuel at constant pressure, a periodic activation of an injector for a time dependent upon engine operating conditions, as determined by voltages V1 and V2, will meter the fuel supplied to the engine through each injector.
  • the control pulse generator 1 is basically similar to that shown in FIG. 2 of the aforementioned copending application, and is in the form of a monostable multivibrator circuit comprising transistors TRl and TR2 and including the timing capacitor C1, which during the timing period is discharged through the constant current transistor TR4.
  • transistor TR2 In the steady state or rest condition of the circuit, transistor TR2 is held in the normally ON condition, its base current being supplied by the collector current of the NPN transistor TR4. At this time, transistor TRl is held OFF by a negative bias voltage Vb supplied from the voltage divider network P connected across the battery supply voltage Vs. In practice, this network may be located in the computer circuit. When a negative-going trigger pulse is applied to the base of transistor TRl, it is turned ON and transistor TR2 is turned OFF.
  • Transistor TR3 provides a low impedance charge path for capacitor C1 when transistor TR2 is turned ON.
  • the duration of the pulses produced by the multivibrator is determined by the voltage change across capacitor C1 and the discharge current through transistor TR4.
  • the control of the voltage change across capacitor C1 is effected by a control voltage V1 derived from the computer circuit and dependent, for example, upon inlet manifold pressure, engine speed and acceleration.
  • the discharge current through transistor TR4 is varied by control voltage V2 also derived from the computer circuit and varying, for example, in dependence with engine water temperature, air temperature, a starting enrichment signal and an idling enrichment signal.
  • the bias voltage Vb applied to the emitter of transistor TRI is derived from a purely resistive voltage divider connected across the battery supply voltage, and hence the fuel delivery through an injector is substantially dependent on variations in the voltage of the battery supply.
  • the voltage divider P connected across the battery supply voltage Vs includes a non-linear element, such as Zener diode Z1. Since the voltage across the Zener diode remains practically constant as its current increases, the voltage across the remaining resistive parts of the voltage divider increases in proportion faster than the supply voltage, including the bias voltage Vb which is developed across resistor Rb. In this way the bias voltage applied to the emitters of transistors TRl and TR2 is increased at a greater rate than the supply voltage. The voltage change across capacitor C1 which in part determines the pulse width is thus increased at a lesser rate than the supply voltage, so that the width of the pulse energising the fuel injection valves is reduced to compensate for the shorter opening time of the valves at the increased supply voltage.
  • a non-linear element such as Zener diode Z1. Since the voltage across the Zener diode remains practically constant as its current increases, the voltage across the remaining resistive parts of the voltage divider increases in proportion faster than the supply voltage, including the bias voltage Vb which is developed across resistor Rb.
  • Zener diodes can be obtained with a wide range of working voltages, a close approximation to the right amount of compensation can be obtained to suit the characteristic of any particular type of fuel injector.
  • one or more forward conducting Zener diodes or saturated normal diodes may be used connected in series in the voltage divider network.
  • the fuel delivery from the or each fuel injector is substantially independent of variations in the vehicle battery voltage and varies only in accordance with the control voltages applied to the control pulse generator, as determined by parameters of engine operation.
  • a fuel injection system for internal combustion engines comprising at least one electromagnetically operated fuel injector and a control pulse generator producing pulses for energising said at least one injector, so that the injector or a injector is opened for a period depending on the duration of each of the pulses to pass fuel to the engine, wherein means are provided for compensating for the effect of supply voltage variations on the time that an injector is open in response to a pulse from the control pulse generator, said compensating means comprising means for varying a bias voltage applied to the control pulse generator by a greater percentage in like polarity than a percentage variation of the total supply voltage, whereby the quantity of fuel injected by the or each injector is substantially independent or variations in said supply voltage.
  • control pulse generator comprises a monostable multivibrator and means are provided for varying a bias applied to the monostable multivibrator with changes in the supply voltage.
  • a system as claimed in claim 2, wherein the bias applied to the monostable multivibrator is derived from a network connected across the voltage supply.
  • the monostable multivibrator includes a timing capacitor and is so arranged that the voltage change across the timing capacitor, which in part determines the pulse width produced by the multivibrator, is increased at a lesser rate than an increase in the supply voltage, so that the width of the pulses energising the fuel injector or injectors is reduced to compensate for the shorter opening time of an injector which occurs at an increased supply voltage.
  • a fuel injection system for internal combustion engines comprising at least one electromagnetically operated fuel injector and a control pulse generator producing pulses for energising said at least one injector, so that the injector or a injector is opened for a period depending on the duration of each of the pulses to pass fuel to the engine
  • the improvement which comprises providing means for compensating for the effect of supply voltage variations on the time that an injector is open in response to a pulse from the control pulse generator, said compensating means comprising means for varying a bias voltage applied to the control pulse generator by a greater percentage in like polarity than a percentage variation of the total suply voltage, whereby the quantity of fuel delivered by the or each injector is substantially independent of variations in said supply voltage.
  • control pulse generator comprises a monostable multivibrator, means are provided for varying a bias applied to the monostable multivibrator with changes in the supply voltage and the bias applied to the monostable multivibrator is derived from a network connected across the voltage supply and including a non-linear element.
  • a computer circuit fed with a plurality of signals which respectively vary with variations in different parameters of engine operation and which provides at least one variable voltage fed to control the duration of the pulses produced by the control pulse generator.
  • the monostable multivibrator includes a timing capacitor and is so arranged that the voltage change across the timing capacitor, which in part determines the pulse width produced by the multivibrator, is increased at a lesser rate than an increase in the supply voltage, so that the Width of the pulses energising the fuel injector or injectors is reduced to compensate for the shorter opening time of an injector which occurs at an increased supply voltage.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
  • Fuel-Injection Apparatus (AREA)
US702032A 1967-02-07 1968-01-31 Fuel injection systems for internal combustion engines Expired - Lifetime US3513815A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB5878/67A GB1208570A (en) 1967-02-07 1967-02-07 Fuel injection systems for internal combustion engines

Publications (1)

Publication Number Publication Date
US3513815A true US3513815A (en) 1970-05-26

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Family Applications (1)

Application Number Title Priority Date Filing Date
US702032A Expired - Lifetime US3513815A (en) 1967-02-07 1968-01-31 Fuel injection systems for internal combustion engines

Country Status (6)

Country Link
US (1) US3513815A (enExample)
JP (1) JPS4940575B1 (enExample)
DE (1) DE1601358A1 (enExample)
FR (1) FR1555024A (enExample)
GB (1) GB1208570A (enExample)
SE (1) SE337506B (enExample)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3646915A (en) * 1970-06-16 1972-03-07 Bendix Corp Cold start auxiliary circuit for electronic fuel control system
US3797465A (en) * 1970-07-04 1974-03-19 Nippon Denso Co Fuel injection system for internal combustion engines
US4173030A (en) * 1978-05-17 1979-10-30 General Motors Corporation Fuel injector driver circuit
US4417201A (en) * 1971-04-01 1983-11-22 The Bendix Corporation Control means for controlling the energy provided to the injector valves of an electrically controlled fuel system

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1362808A (en) * 1970-12-31 1974-08-07 Nissan Motor Fuel injection system incorporating shift shock preventing device
JPS50114098A (enExample) * 1975-01-24 1975-09-06
GB1564496A (en) * 1975-09-05 1980-04-10 Lucas Industries Ltd Electronic fuel injection control for an internal combustion engine
JPS5866297U (ja) * 1981-10-27 1983-05-06 株式会社オンダ 磁石標的板
DE3445414A1 (de) * 1984-12-13 1986-06-19 Robert Bosch Gmbh, 7000 Stuttgart Elektronisch gesteuertes kraftstoffeinspritzsystem fuer eine brennkraftmaschine
JPS61255234A (ja) * 1985-05-08 1986-11-12 Honda Motor Co Ltd 内燃エンジンの始動時の燃料供給制御方法

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2910054A (en) * 1957-05-04 1959-10-27 Bosch Gmbh Robert Electronic fuel injection control system

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2910054A (en) * 1957-05-04 1959-10-27 Bosch Gmbh Robert Electronic fuel injection control system

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3646915A (en) * 1970-06-16 1972-03-07 Bendix Corp Cold start auxiliary circuit for electronic fuel control system
US3797465A (en) * 1970-07-04 1974-03-19 Nippon Denso Co Fuel injection system for internal combustion engines
US4417201A (en) * 1971-04-01 1983-11-22 The Bendix Corporation Control means for controlling the energy provided to the injector valves of an electrically controlled fuel system
US4173030A (en) * 1978-05-17 1979-10-30 General Motors Corporation Fuel injector driver circuit

Also Published As

Publication number Publication date
DE1601358A1 (de) 1970-11-19
FR1555024A (enExample) 1969-01-24
GB1208570A (en) 1970-10-14
JPS4940575B1 (enExample) 1974-11-02
SE337506B (enExample) 1971-08-09

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Owner name: LUCAS INDUSTRIES PUBLIC LIMITED COMPANY, GREAT KIN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:AE PLC;REEL/FRAME:004297/0061

Owner name: AE PLC

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:ASSOCIATED ENGINEERING LIMITED;REEL/FRAME:004297/0066