US3800749A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for regulating the duration of a square-wave signal in an electronic injection control installation for diesel engines
Assignee: SOFREDI
•
Filing: 1971-07-26
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Granted: 1974-04-02
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Expires: 1991-07-26
Abstract
Abstract An electronic apparatus for controlling the injection period of internal combustion engines having electromagnetic fuel injectors in accordance with a predetermined relation between injection period and engine speed. A pulse generator synchronized with engine rotation generates pulses corresponding to each successive injection period. Each pulse triggers a function generator for developing a reference voltage which is a real time analog of a predetermined curve of fuel quantity per injection (or injection period) versus time between injections. Each pulse simultaneously triggers a circuit for generating a rectangular delay signal of a variable duration which is inversely proportional to a selected engine speed. A memory circuit initiates the development of a regulating voltage in response to the termination of the rectangular delay signal. The magnitude of the regulating voltage rises from zero until it corresponds to the instantaneous value of the simultaneously developing analog reference voltage and then follows the reference voltage until initiation of the succeeding pulse from the pulse generator. A fuel injection signal generator initiates a rectangular fuel injection signal in response to the succeeding pulse from the pulse generator, the duration of the injection signal being a direct function of the instantaneous value of the regulating voltage at the moment of initiation of the injection signal.
Inventors
- 👤 P Advenier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:56
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/30; F02D41/32; F02B; F02B2275/00; F02B2275/14; F02B3/00; F02B3/06; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
418 words
An electronic apparatus for controlling the injection periods of diesel engines having electromagnetic fuel injectors in accordance with a predetermined relation between injection period and engine speed under full load, the apparatus comprising: a pulse generator synchronized with engine rotation for providing a short triggering pulse corresponding to each successive injection period; a function generator connected to the pulse generator for developing an analog reference voltage in response to a first triggering pulse from the pulse generator, the value of the analog reference voltage varying as a function of time after the first triggering pulse so as to reproduce a predetermined curve of fuel quantity per injection versus time between injections under full load conditions at all engine operating speeds, the development of the analog reference voltage being terminated in response to a second triggering pulse next succeeding the first triggering pulse from the pulse generator; means for selecting a desired engine speed; a delay signal generator connected to the pulse generator and the speed selecting means for initiating a rectangular delay signal of variable duration in response to the first triggering pulse, the duration of the signal being controlled by the speed selection means as an inverse function of the selected speed; means connected to the pulse generator, the delay signal generator and the function generator for developing a regulating voltage waveform that is initiated in response to the termination of the rectangular delay signal, that rises from zero at a predetermined rate until it corresponds in value to the analog reference signal, and that follows the value of the analog reference signal until receipt of the second triggering pulse next succeeding the first pulse from the pulse generator; and a fuel injection signal generator connected to the pulse generator and to the means for developing the regulating voltage waveform for initiating in response to the second triggering pulse a rectangular fuel injection signal for actuating one of the fuel injectors, the duration of the fuel injection signal being determined by the value of the regulating voltage at the instant of the second triggering pulse, the second triggering pulse then serving as a first triggering pulse for initiating development of the analog reference voltage by the function generator for controlling the duration of the next succeeding fuel injection signal, whereby the amount of fuel injected during each fuel injection signal will increase to full load values if engine speed falls below the set speed and will decrease to zero if engine speed increases above the set speed.
Claim 2
Dependent Claim
418 words
An electronic apparatus for controlling the injection periods of diesel engines having electromagnetic fuel injectors in accordance with a predetermined relation between injection period and engine speed under full load, the apparatus comprising: a pulse generator synchronized with engine rotation for providing a short triggering pulse corresponding to each successive injection period; a function generator connected to the pulse generator for developing an analog reference voltage in response to a first triggering pulse from the pulse generator, the value of the analog reference voltage varying as a function of time after the first triggering pulse so as to reproduce a predetermined curve of fuel quantity per injection versus time between injections under full load conditions at all engine operating speeds, the development of the analog reference voltage being terminated in response to a second triggering pulse next succeeding the first triggering pulse from the pulse generator; means for selecting a desired engine speed; a delay signal generator connected to the pulse generator and the speed selecting means for initiating a rectangular delay signal of variable duration in response to the first triggering pulse, the duration of the signal being controlled by the speed selection means as an inverse function of the selected speed; means connected to the pulse generator, the delay signal generator and the function generator for developing a regulating voltage waveform that is initiated in response to the termination of the rectangular delay signal, that rises from zero at a predetermined rate until it corresponds in value to the analog reference signal, and that follows the value of the analog reference signal until receipt of the second triggering pulse next succeeding the first pulse from the pulse generator; and a fuel injection signal generator connected to the pulse generator and to the means for developing the regulating voltage waveform for initiating in response to the second triggering pulse a rectangular fuel injection signal for actuating one of the fuel injectors, the duration of the fuel injection signal being determined by the value of the regulating voltage at the instant of the second triggering pulse, the second triggering pulse then serving as a first triggering pulse for initiating development of the analog reference voltage by the function generator for controlling the duration of the next succeeding fuel injection signal, whereby the amount of fuel injected during each fuel injection signal will increase to full load values if engine speed falls below the set speed and will decrease to zero if engine speed increases above the set speed.
Claim 3
Dependent Claim
163 words
The injection control apparatus of claim 1 wherein the function generator comprises: an electrical energy storage element; a plurality of means connected to the storage element for successively augmenting or depleting the electrical energy stored in the storage element at predetermined rates corresponding to average slopes of segments of the predetermined curve of fuel quantity per injection; a plurality of delay circuits, each delay circuit being associated with one of the plurality of means for augmenting or depleting the electrical energy stored in the storage element and connected to the pulse generator for actuating its associated energy augmenting or depleting means at a different predetermined delay time after said first pulse, each delay time corresponding to the start of the related segment of said predetermined curve, whereby the voltage across the energy storage element increases and decreases as a function of time following said first pulse in conformance with the predetermined curve of fUel quantity per injection to develop said analog reference voltage.
Claim 4
Dependent Claim
61 words
The injection control apparatus of claim 2 wherein each of the plurality of means for augmenting or depleting the electrical energy stored in the storage element comprises a current generator for permitting a flow of current between the energy storage element and a positive or a negative voltage supply, respectively, in response to an actuating signal from its associated delay circuit.
Claim 5
Dependent Claim
62 words
The injection control apparatus of claim 3 wherein each of the plurality of delay circuits comprises a monostable multivibrator, each of the monostable multivibrators having an unstable state of different predetermined time period and being triggered into its unstable state by the first triggering pulse, for actuating its associated electrical energy augmenting or depleting means at the termination of its unstable state.
Claim 6
Dependent Claim
272 words
The injection control apparatus of claim 4 wherein the plurality of current generators and monostable multivibrators comprise: a first monostable multivibrator having a first unstable time period approximately equal to the time between successive triggering pulses at maximum engine speed; a first current generator actuated upon termination of the unstable period of the first monostable multivibrator for conducting current to the electrical energy storage element to augment the energy stored in the element at a first substantially constant rate; a second monostable multivibrator having a second unstable time period approximately equal to the time between successive triggering pulses at the engine speed corresponding to maximum fuel demand per injection; a second current generator actuated upon termination of the unstable period of the second monostable multivibrator for conducting current from the electrical energy storage element to deplete the energy stored in the element at a second substantially constant rate, greater than the first rate; a third monostable multivibrator having a third unstable time period approximately equal to the time between successive triggering pulses at minimum engine speed; and a third current generator actuated upon termination of the unstable period of the third monostable multivibrator for conducting current to the electrical energy storage element to augment the energy stored in the element at a third rate, greater than the difference between the first and second rates, whereby the voltage across the electrical energy storage element increases approximately linearly between the ends of the second and third time periods, then decreases approximately linearly between the ends of the second and third time periods, and finally increases again after the end of the third time period.
Claim 7
Dependent Claim
147 words
The injection control apparatus of claim 5 wherein the first and third current generators each comprise an electrical resistance element, connected at one terminal to a voltage source, and a transistor connected between the other terminal of the resistance element and the electrical energy storage means, the transistor being rendered conductive at the termination of the unstable time period of the associated monostable multivibrator for conducting current from the source through the resistance element to the electrical energy storage element, and the second current generator comprises an electrical resistance element, connected at one terminal to ground, and a transistor connected between the other terminal of the resistance element and the electrical energy storage element, the transistor being rendered conductive at the end of the unstable time period of the second monostable multivibrator for conducting current from the electrical energy storage unit through the resistance element to ground.
Claim 8
Dependent Claim
46 words
The injection control apparatus of claim 1 further comprising: a first switching element connected to the pulse generator and to the output of the function generator for returning the value of the analog reference voltage to zero in responsE to each pulse from the pulse generator.
Claim 9
Dependent Claim
123 words
The injection control apparatus of claim 7 wherein the means for developing the regulating voltage waveform comprises: an electrical energy storage element; A current generator for augmenting at a predetermined rate the electrical energy stored in the storage element in response to termination of the rectangular delay signal from the delay signal generator. a second switching element sensitive to the difference between the analog reference voltage and the voltage across the second energy storage element for diverting the current flowing from the current generator away from the energy storage element when said voltage difference becomes approximately equal to zero; and a third switching element responsive to actuation of the second switching element for applying the analog reference voltage to the energy storage element.
Claim 10
Dependent Claim
47 words
The injection control apparatus of claim 8 further comprising: a fourth switching element in parallel with the electrical energy storage element for reducing the voltage across the storage element to zero in response to the termination of each fuel injection pulse from the fuel injection signal generator.
Claim 11
Dependent Claim
53 words
The injection control apparatus of claim 5 further comprising: an engine starter switch and a normally open time-delay switch connected between the pulse generator and the third monostable multivibrator and actuated by the engine starter switch for preventing triggering pulses from actuating the third monostable multivibrator except when the engine is being started.
Claim 12
Dependent Claim
215 words
The injection control apparatus of claim 4 wherein each monostable multivibrator comprises: a voltage source; a variable resistance having one terminal connected to one terminal of the voltage source; a voltage divider connected across the voltage source and having a tap connection for supplying a predetermined voltage intermediate the voltages at the source terminals; a programmable unijunction transistor having an anode connected to the other terminal of the variable resistance, a cathode connected to the other terminal of the voltage source, and a control electrode connected to the top of the voltage divider; a capacitor connected in parallel with the anode-cathode circuit of the programmable unijunction transistor; and an input transistor having a base, a collector and an emitter, its collector-emitter circuit being connected in parallel with the capacitor and its base being connected to the pulse generator, the input transistor becoming conductive for the duration of each pulse from the pulse generator for discharging the capacitor and thereby rendering the unijunction transistor nonconductive, the capacitor subsequently charging through the variable resistance until its voltage reaches a value in relation to the intermediate voltage on the control electrode of the unijunction transistor sufficient to render the unijunction transistor conductive again, and the charging time for the capacitor being predetermined by adjustment of the variable resistance.
Claim 13
Dependent Claim
128 words
The injection control apparatus of claim 8 wherein the means for developing a regulating voltage waveform further comprises: a unidirectional current control device having one terminal connected to the current generator and the other terminal connected to one terminal of the electrical energy storage element for providing a low resistance path for charging current from the current generator to the energy storage element and a resistive element connected in parallel with the unidirectional current control device for providing a high resistance path for discharging current from the energy storage element, the second switching element being connected to the junction between the current generator and the one terminal of the unidirectional current device for diverting the current flow from the current generator without simultaneously discharging the energy storage element.
Claim 14
Dependent Claim
96 words
The injection control apParatus of claim 12 wherein: the second switching element comprises a programmable unijunction transistor having an anode connected to the junction between the current generator and the unidirectional current control device, a control electrode connected to the output of the function generator, and a cathode connected to the other terminal of the energy storage device, whereby the unijunction transistor becomes conductive for bypassing the charging current from the current generator around the energy storage device when the voltage on its anode rises to approximately the voltage at the output of the function generator.
Claim 15
Dependent Claim
167 words
The injection control apparatus of claim 13 wherein: the second switching element further comprises a load resistor connected between the cathode of the programmable unijunction transistor and the other terminal of the energy storage device for developing a control voltage when the unijunction transistor is conducting; the third switching element comprises a first transistor having its base connected to the load resistor for becoming conductive in response to the control voltage developed when the programmable unijunction transistor is conductive and a second transistor having its base connected to the collector of the first transistor for becoming nonconductive in response to conduction of the first transistor and its collector connected to the output of the function generator; and the apparatus further comprises an emitter-follower having its input connected to the collector of the second transistor and its output connected to the one terminal of the electrical energy storage device for applying the output of the function generator to the energy storage device when the second transistor is nonconductive.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-01 | 1977-10-01 | 1978-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-01 | 1981-10-01 | 1982-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-01 | 1985-10-01 | 1986-04-02 | $7700.00 | Window Closed / Lapsed |