US3685526A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fuel control system for internal combustion engines
Assignee: Denso Corp
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Filing: 1970-05-14
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Granted: 1972-08-22
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Expires: 1990-05-14
Abstract
Abstract A fuel control system for internal combustion engines comprising a control voltage generation circuit for generating a control voltage representative of the operating conditions of an engine, a capacitor-resistor coupled type monostable timer circuit composed of two transistors and having the time constant fixed at a certain value, said control voltage being applied through the resistor to the collector of that one of said transistors which is in the cut-off state when said timer circuit is in its stable state, a current amplifier circuit adapted to amplify for current amplification the output timing pulse from said monostable timer circuit to operate an electromagnetic metering valve, and a trigger signal generating circuit for producing a trigger signal at the fuel metering time of the engine to trigger said monostable timer circuit.
Inventors
- 👤 Nobuhito Hobo
- 👤 Yoshimi Natsume
- 👤 Sumihiro Kaga
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:24
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/30; F02D41/32; F02D41/36; F02D41/365; F02B; F02B1/00; F02B1/02; F02B1/04
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
400 words
A fuel control system for controlling a fuel supply to an internal combustion engine through an electromagnetic valve comprising a control voltage generating circuit for producing a first control voltage representing operating conditions of the engine, a trigger signal generating circuit for producing a trigger signal at the fuel metering time of the engine, a monostable multivibrator type timer circuit having a normally stable state and an unstable state and having first and second input terminals respectively connected to said generating circuits for respectively receiving said first control voltage and said trigger signal, said timer circuit being triggered from said stable state to said unstable state by said trigger signal and further having a third input terminal for receiving a second control voltage and having only first and second transistors which are connected to said three terminals, each of said transistors having respective collector, emitter and base electrodes with the emitter electrodes being connected together, said collector electrodes of each transistor being cross coupled to the base electrode of the other transistor, means including a first resistor in the said cross coupling of the collector electrode of said second transistor with the base of the first transistor for causing the second transistor to be normally conductive while said timer circuit is in said stable state, a capacitor in the said cross coupling from said first transistor collector electrode to the second transistor base electrode and forming first and second junction points therewith respectively, a first path including said second transistor base and emitter electrodes and a second resistor connected only between said first input terminal and said first junction point for charging said capacitor by said first control voltage when said second transistor is conductive as aforesaid, there being between said second junction point and said third input terminal only a resistance having a resistance value which is independent of the value of said second control voltage and which forms with said capacitor and first transistor collector and emitter electrodes a second path for discharging said capacitor when said timer circuit is triggered to said unstable state to cause from said second transistor an output timing pulse having a time duration proportional to said first control voltage and inversely proportional to said second control voltage, and an amplifier connected to said timer circuit and adapted for connection to said electromagnetic valve for supplying thereto an amplification of said timing pulse.
Claim 2
Dependent Claim
400 words
A fuel control system for controlling a fuel supply to an internal combustion engine through an electromagnetic valve comprising a control voltage generating circuit for producing a first control voltage representing operating conditions of the engine, a trigger signal generating circuit for producing a trigger signal at the fuel metering time of the engine, a monostable multivibrator type timer circuit having a normally stable state and an unstable state and having first and second input terminals respectively connected to said generating circuits for respectively receiving said first control voltage and said trigger signal, said timer circuit being triggered from said stable state to said unstable state by said trigger signal and further having a third input terminal for receiving a second control voltage and having only first and second transistors which are connected to said three terminals, each of said transistors having respective collector, emitter and base electrodes with the emitter electrodes being connected together, said collector electrodes of each transistor being cross coupled to the base electrode of the other transistor, means including a first resistor in the said cross coupling of the collector electrode of said second transistor with the base of the first transistor for causing the second transistor to be normally conductive while said timer circuit is in said stable state, a capacitor in the said cross coupling from said first transistor collector electrode to the second transistor base electrode and forming first and second junction points therewith respectively, a first path including said second transistor base and emitter electrodes and a second resistor connected only between said first input terminal and said first junction point for charging said capacitor by said first control voltage when said second transistor is conductive as aforesaid, there being between said second junction point and said third input terminal only a resistance having a resistance value which is independent of the value of said second control voltage and which forms with said capacitor and first transistor collector and emitter electrodes a second path for discharging said capacitor when said timer circuit is triggered to said unstable state to cause from said second transistor an output timing pulse having a time duration proportional to said first control voltage and inversely proportional to said second control voltage, and an amplifier connected to said timer circuit and adapted for connection to said electromagnetic valve for supplying thereto an amplification of said timing pulse.
Claim 3
Dependent Claim
353 words
A fuel control system for controlling a fuel supply to an internal combustion engine through an electromagnetic valve comprising a control voltage generating circuit for producing a control voltage representing operating conditions of the engine, a trigger signal generating circuit for producing a trigger signal at the fuel metering time of the engine, a capacitor-resistor coupled type monostable timer circuit composed of two transistors and having a time constant fixed at a given value, said monostable timer circuit being connected to receive the control voltage generated by said control voltage generating circuit through the resistor at the collector of that one transistor of said two transistors which is in the cutoff state when said timer circuit is in the stable state, said monostable timer circuit being provided with a further control voltage application terminal at one end of the resistor opposite the junction point between the capacitor and the resistor constituting the time constant element, and said monostable timer circuit also being connected to said trigger signal generating circuit to receive said trigger signal to thereby be triggered to an unstable state and produce a timing pulse signal having a time duration dependent substantially upon the ratio of said control voltage to said further control voltage, a current amplifier circuit connected to said monostable timer circuit for current amplification of the timing pulse produced by said monostable timer circuit so as to actuate the electromagnetic valve, said system being for internal combustion engines having a crankshaft and accelerator, and wherein said control voltage generating circuit comprises a speed voltage generating circuit which includes an AC generator linked with the engine crankshaft, a diode for rectifying the output of said generator and a smoothing capacitor; a preset voltage generating circuit including a variable resistor linked with the accelerator for producing a voltage proportional to the accelerator position; and a transistor connected so that the output thereof is controlled by the difference between the output of said speed voltage generating circuit and the output of said preset voltage generating circuit, whereby a control voltage related to the accelerator position and the engine speed is produced.
Claim 4
Dependent Claim
353 words
A fuel control system for controlling a fuel supply to an internal combustion engine through an electromagnetic valve comprising a control voltage generating circuit for producing a control voltage representing operating conditions of the engine, a trigger signal generating circuit for producing a trigger signal at the fuel metering time of the engine, a capacitor-resistor coupled type monostable timer circuit composed of two transistors and having a time constant fixed at a given value, said monostable timer circuit being connected to receive the control voltage generated by said control voltage generating circuit through the resistor at the collector of that one transistor of said two transistors which is in the cutoff state when said timer circuit is in the stable state, said monostable timer circuit being provided with a further control voltage application terminal at one end of the resistor opposite the junction point between the capacitor and the resistor constituting the time constant element, and said monostable timer circuit also being connected to said trigger signal generating circuit to receive said trigger signal to thereby be triggered to an unstable state and produce a timing pulse signal having a time duration dependent substantially upon the ratio of said control voltage to said further control voltage, a current amplifier circuit connected to said monostable timer circuit for current amplification of the timing pulse produced by said monostable timer circuit so as to actuate the electromagnetic valve, said system being for internal combustion engines having a crankshaft and accelerator, and wherein said control voltage generating circuit comprises a speed voltage generating circuit which includes an AC generator linked with the engine crankshaft, a diode for rectifying the output of said generator and a smoothing capacitor; a preset voltage generating circuit including a variable resistor linked with the accelerator for producing a voltage proportional to the accelerator position; and a transistor connected so that the output thereof is controlled by the difference between the output of said speed voltage generating circuit and the output of said preset voltage generating circuit, whereby a control voltage related to the accelerator position and the engine speed is produced.
Claim 5
Dependent Claim
317 words
A fuel control system for controlling a fuel supply to an internal combustion engine through an electromagnetic valve comprising a control voltage generating circuit for producing a control voltage representing operating conditions of the engine, a trigger signal generating circuit for producing a trigger signal at the fuel metering time of the engine, a capacitor-resistor coupled type monostable timer circuit composed of two transistors and having a time constant fixed at a given value, said monostable timer circuit being connected to receive the control voltage generated by said control voltage generating circuit through the resistor at the collector of that one transistor of said two transistors which is in the cutoff state when said timer circuit is in the stable state, said monostable timer circuit being provided with a further control voltage application terminal at one end of the resistor opposite the junction point between the capacitor and the resistor constituting the time constant element, and said monostable timer circuit also being connected to said trigger signal generating circuit to receive said trigger signal to thereby be triggered to an unstable state and produce a timing pulse signal having a time duration dependent substantially upon the ratio of said control voltage to said further control voltage, a current amplifier circuit connected to said monostable timer circuit for current amplification of the timing pulse produced by said monostable timer circuit so as to actuate the electromagnetic valve, said system being for internal combustion crankshaft and accelerator engines and wherein said control voltage generating circuit comprises a centrifugal governor means linked with the engine crankshaft, a variable resistor having a slidable contact coupled with said governor so as to vary the resistance value thereof in relation to the engine speed, and a mechanism interlinking said governor means with the accelerator mechanism of the engine, whereby a control voltage related to the accelerator position and the engine speed is obtained.
Claim 6
Dependent Claim
317 words
A fuel control system for controlling a fuel supply to an internal combustion engine through an electromagnetic valve comprising a control voltage generating circuit for producing a control voltage representing operating conditions of the engine, a trigger signal generating circuit for producing a trigger signal at the fuel metering time of the engine, a capacitor-resistor coupled type monostable timer circuit composed of two transistors and having a time constant fixed at a given value, said monostable timer circuit being connected to receive the control voltage generated by said control voltage generating circuit through the resistor at the collector of that one transistor of said two transistors which is in the cutoff state when said timer circuit is in the stable state, said monostable timer circuit being provided with a further control voltage application terminal at one end of the resistor opposite the junction point between the capacitor and the resistor constituting the time constant element, and said monostable timer circuit also being connected to said trigger signal generating circuit to receive said trigger signal to thereby be triggered to an unstable state and produce a timing pulse signal having a time duration dependent substantially upon the ratio of said control voltage to said further control voltage, a current amplifier circuit connected to said monostable timer circuit for current amplification of the timing pulse produced by said monostable timer circuit so as to actuate the electromagnetic valve, said system being for internal combustion crankshaft and accelerator engines and wherein said control voltage generating circuit comprises a centrifugal governor means linked with the engine crankshaft, a variable resistor having a slidable contact coupled with said governor so as to vary the resistance value thereof in relation to the engine speed, and a mechanism interlinking said governor means with the accelerator mechanism of the engine, whereby a control voltage related to the accelerator position and the engine speed is obtained.
Claim 7
Dependent Claim
49 words
A fuel control system as defined in claim 1 wherein said third input terminal of said monostable timer circuit is connected to a constant DC voltage source to thereby produce a timing pulse having a duration dependent substantially upon said control voltage supplied by said control voltage generating circuit.
Claim 8
Dependent Claim
47 words
A fuel control system as defined in claim 1 wherein said monostable timer circuit and said current amplifier circuit are provided respectively in the same number as that of engine cylinders, and a single control voltage generating circuit and a single trigger signal generating circuit are provided.
Claim 9
Dependent Claim
163 words
A fuel control system for controlling a fuel supply to an internal combustion engine through an electromagnetic valve mounted to the engine comprising means for producing a first control voltage representing the operating condition of the engine, means for producing a trigger signal at the fuel metering time of the engine, means for supplying a second control voltage, a monostable timer circuit for producing a timing pulse and having an input transistor connected to receive said trigger signal and an interconnected output transistor and a time constant element including a capacitor and a resistor connected directly to said second control voltage, the capacitor of said element being charged by said first control voltage through a second resistor to said output transistor and discharged through said input transistor and the resistor of said element to said second control voltage supply means when said trigger signal renders said input transistor conductive, and means for applying said timing pulse so as to actuate said electromagnetic valve.
Claim 10
Dependent Claim
163 words
A fuel control system for controlling a fuel supply to an internal combustion engine through an electromagnetic valve mounted to the engine comprising means for producing a first control voltage representing the operating condition of the engine, means for producing a trigger signal at the fuel metering time of the engine, means for supplying a second control voltage, a monostable timer circuit for producing a timing pulse and having an input transistor connected to receive said trigger signal and an interconnected output transistor and a time constant element including a capacitor and a resistor connected directly to said second control voltage, the capacitor of said element being charged by said first control voltage through a second resistor to said output transistor and discharged through said input transistor and the resistor of said element to said second control voltage supply means when said trigger signal renders said input transistor conductive, and means for applying said timing pulse so as to actuate said electromagnetic valve.
Claim 11
Dependent Claim
13 words
A system as in claim 6, wherein said second control voltage is constant.
Claim 12
Dependent Claim
62 words
A system as in claim 6, wherein said means for producing said first control voltage comprises: means for generating a voltage corresponding to engine speed, means for producing a voltage proportional to the accelerator position of the engine, and means in said timer circuit for producing said timing pulse in response to the difference between said engine speed and accelerator position voltages.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-22 | 1976-02-21 | 1976-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-22 | 1980-02-21 | 1980-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-22 | 1984-02-21 | 1984-08-22 | $7700.00 | Window Closed / Lapsed |