US3885720A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and system for controlling combustion timing of an internal combustion engine
Assignee: Mobil Oil AS
•
Filing: 1973-01-10
•
Granted: 1975-05-27
•
Expires: 1993-01-10
Abstract
Abstract The specific disclosure provides for controlling ignition timing of an internal combustion engine by triggering a sawtooth wave generator to generate a sawtooth signal having a frequency equal to the firing frequency of the engine. A feedback network maintains the amplitude of the sawtooth wave signal at a constant level in response to the frequency of the sawtooth wave signal. A voltage detector adjustable to an ignition timing set point detects the set point voltage during the generation of each sawtooth and provides an ignition trigger signal for firing the engine upon each detection of the set point voltage. Another voltage detector may be provided which is adjustable to a fuel injection timing set point for detecting a fuel injection set point voltage during the generation of each sawtooth and for providing a fuel injection trigger signal upon each detection of the fuel injection set point voltage.
Inventors
- 👤 William R Brennan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:07
CPC Classifications
F; F02; F02P; F02P5/00; F02P5/04; F02P5/145; F02P5/155; F02P5/1553; F02P5/1556; F02B; F02B1/00; F02B1/02; F02B1/04; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/40
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
267 words
A system for controlling the timing of the combustion cycle in an internal combustion engine having a rotatable power shaft, said system comprising: means responsive to rotation of said power shaft for generating sequential input trigger signals having a frequency proportional to the speed of rotation of said power shaft; a waveform generator responsive to said input trigger signals for generating sequential sawtooth waveforms, each of said sawtooth waveforms having a duration corresponding to a predetermined number of degrees of power shaft rotation and having an amplitude changing as a function of time; feedback means responsive to said waveform generator for maintaining the maximum amplitude of said sawtooth waveforms at a substantially constant level for all engine speeds by varying the rate of change of the amplitude as a function of engine speed such that a given instantaneous magnitude of each sawtooth waveform corresponds to a predetermined angular position of the power shaft regardless of engine speed; means for generating a set point signal corresponding to a predetermined angle of rotation of said power shaft; means for detecting when the amplitude of each of said sawtooth waveforms reaches a level defined by said set point signal so as to correspond to a predetermined angle of rotation of said power shaft; means responsive to said detecting means for generating an engine trigger signal corresponding in time to a predetermined angle of rotation of said power shaft; and means for adjusting said set point signal so as to adjust the timing of said engine trigger signal to correspond with a different predetermined angle of rotation of said power shaft.
Claim 2
Independent Claim
267 words
A system for controlling the timing of the combustion cycle in an internal combustion engine having a rotatable power shaft, said system comprising: means responsive to rotation of said power shaft for generating sequential input trigger signals having a frequency proportional to the speed of rotation of said power shaft; a waveform generator responsive to said input trigger signals for generating sequential sawtooth waveforms, each of said sawtooth waveforms having a duration corresponding to a predetermined number of degrees of power shaft rotation and having an amplitude changing as a function of time; feedback means responsive to said waveform generator for maintaining the maximum amplitude of said sawtooth waveforms at a substantially constant level for all engine speeds by varying the rate of change of the amplitude as a function of engine speed such that a given instantaneous magnitude of each sawtooth waveform corresponds to a predetermined angular position of the power shaft regardless of engine speed; means for generating a set point signal corresponding to a predetermined angle of rotation of said power shaft; means for detecting when the amplitude of each of said sawtooth waveforms reaches a level defined by said set point signal so as to correspond to a predetermined angle of rotation of said power shaft; means responsive to said detecting means for generating an engine trigger signal corresponding in time to a predetermined angle of rotation of said power shaft; and means for adjusting said set point signal so as to adjust the timing of said engine trigger signal to correspond with a different predetermined angle of rotation of said power shaft.
Claim 3
Dependent Claim
22 words
The system of claim 1, wherein the instantaneous amplitude of each of said wave forms corresponds to a unique angle of rotation.
Claim 4
Dependent Claim
38 words
The system of claim 1, wherein said wave form generator comprises: a capacitor means; and a current source for charging said capacitor means during said predetermined number of degrees of power shaft rotation to generate said wave forms.
Claim 5
Dependent Claim
76 words
The system of claim 1, wherein said feedback means comprises: means for clipping said signals representing the charge on said capacitor means above a predetermined level; and means responsive to the clipped portions of said signals representing the charge on said capacitor means to control the rate of charge of said capacitor means such that said power shaft rotation signals have a unique instantaneous amplitude for a given instantaneous angle of rotation for all engine speeds.
Claim 6
Dependent Claim
17 words
The system of claim 1, wherein said means for adjusting said set point signal is manually adustable.
Claim 7
Dependent Claim
25 words
The system of claim 1, wherein said means for adjusting said set point signal is automatically adjustable in response to at least one engine parameter.
Claim 8
Dependent Claim
20 words
The system of claim 1, including means for initiating sparking in said engine in response to said engine trigger signal.
Claim 9
Dependent Claim
20 words
The system of claim 7, wherein said means for adjusting said set point signal is automatically responsive to combustion knock.
Claim 10
Dependent Claim
20 words
The system of claim 8, wherein said means for adjusting said set point signal is automatically responsive to engine speed.
Claim 11
Dependent Claim
17 words
The system of claim 7, wherein said means for adjusting said set point signal is manually adjustable.
Claim 12
Dependent Claim
32 words
The system of claim 10, further comprising switch means for adjusting The duration of said wave forms to permit the system to be used with engines having different numbers of combustion chambers.
Claim 13
Dependent Claim
27 words
The system of claim 10, further comprising means initiating fuel injection into at least one combustion chamber of said engine in response to said engine trigger signal.
Claim 14
Independent Claim
269 words
A system for controlling the timing of the combustion cycle of an internal combustion engine having a rotatable power shaft, said system comprising: means responsive to rotation of said power shaft for generating sequential input trigger signals having a frequency proportional to the speed of rotation of said power shaft; a waveform generator responsive to said input trigger signals for generating sequential sawtooth waveforms, each of said sawtooth waveforms having a duration corresponding to a predetermined number of degrees of power shaft rotation and having an amplitude changing as a function of time such that a given instantaneous magnitude of each sawtooth waveform corresponds to a predetermined angular position of the power shaft regardless of engine speed; means for maintaining the maximum amplitude of said sawtooth waveforms at a substantially constant level for all engine speeds by varying the instantaneous rate of change of the amplitude as a function of engine speed; means for generating a set point signal corresponding to a predetermined angle of rotation; means for detecting when the amplitude of each of said sawtooth waveforms reaches a level defined by said set point signal so as to correspond to a predetermined angle of rotation of said power shaft; means responsive to said detecting means for generating an engine trigger signal corresponding in magnitude to a predetermined angle of rotation of said power shaft; and means for adjusting said set point signal so as to adjust the timing of said engine trigger signals to correspond with a different predetermined angle of rotation without adjusting said duration of said sawtooth waveforms corresponding to said predetermined number of degrees.
Claim 15
Independent Claim
269 words
A system for controlling the timing of the combustion cycle of an internal combustion engine having a rotatable power shaft, said system comprising: means responsive to rotation of said power shaft for generating sequential input trigger signals having a frequency proportional to the speed of rotation of said power shaft; a waveform generator responsive to said input trigger signals for generating sequential sawtooth waveforms, each of said sawtooth waveforms having a duration corresponding to a predetermined number of degrees of power shaft rotation and having an amplitude changing as a function of time such that a given instantaneous magnitude of each sawtooth waveform corresponds to a predetermined angular position of the power shaft regardless of engine speed; means for maintaining the maximum amplitude of said sawtooth waveforms at a substantially constant level for all engine speeds by varying the instantaneous rate of change of the amplitude as a function of engine speed; means for generating a set point signal corresponding to a predetermined angle of rotation; means for detecting when the amplitude of each of said sawtooth waveforms reaches a level defined by said set point signal so as to correspond to a predetermined angle of rotation of said power shaft; means responsive to said detecting means for generating an engine trigger signal corresponding in magnitude to a predetermined angle of rotation of said power shaft; and means for adjusting said set point signal so as to adjust the timing of said engine trigger signals to correspond with a different predetermined angle of rotation without adjusting said duration of said sawtooth waveforms corresponding to said predetermined number of degrees.
Claim 16
Independent Claim
332 words
A system for controlling the timing of the combustion cycle of an internal combustion engine having a rotatable power shaft, said system comprising; means responsive to rotation of said power shaft for generating sequential input trigger signals having a frequency proportional to the speed of rotation of said power shaft; a sawtooth waveform generator comprising charge storage means and a semiconductor device acting as a current flow path for changing the charge on said charge storage means, said waveform generator being responsive to said input trigger signal for generating a series of sequential waveforms at the output of said charge storage means having a duration corresponding to a predetermined number of degrees of power shaft rotation and having an amplitude continuously changing as a function of time such that a given instantaneous magnitude of each sawtooth waveform corresponds to a predetermined angular position of the power shaft regardless of engine speed; sawtooth waveform control means for generating a control signal having a magnitude representing the speed of rotation of said power shaft and applying said control signal to said semiconductor device to control the current flow path for changing the charge of said charge storage means so as to maintain the maximum amplitude of the sawtooth waveforms at a substantially constant level for engine speeds by varying the instantaneous rate of change of charge as a function of engine speed; means for generating a set point signal corresponding to a predetermined angle of rotation; means for detecting when the amplitude of each of said sawtooth waveforms reaches a level defined by said set point signal so as to correspond to a predetermined angle of rotation of said power shaft; means responsive to said detecting means for generating an engine trigger signal corresponding in time to a predetermined angle of rotation of said power shaft; aNd means for adjusting said set point signal so as to adjust the timing of said engine trigger signal to correspond with a different predetermined angle of rotation.
Claim 17
Independent Claim
332 words
A system for controlling the timing of the combustion cycle of an internal combustion engine having a rotatable power shaft, said system comprising; means responsive to rotation of said power shaft for generating sequential input trigger signals having a frequency proportional to the speed of rotation of said power shaft; a sawtooth waveform generator comprising charge storage means and a semiconductor device acting as a current flow path for changing the charge on said charge storage means, said waveform generator being responsive to said input trigger signal for generating a series of sequential waveforms at the output of said charge storage means having a duration corresponding to a predetermined number of degrees of power shaft rotation and having an amplitude continuously changing as a function of time such that a given instantaneous magnitude of each sawtooth waveform corresponds to a predetermined angular position of the power shaft regardless of engine speed; sawtooth waveform control means for generating a control signal having a magnitude representing the speed of rotation of said power shaft and applying said control signal to said semiconductor device to control the current flow path for changing the charge of said charge storage means so as to maintain the maximum amplitude of the sawtooth waveforms at a substantially constant level for engine speeds by varying the instantaneous rate of change of charge as a function of engine speed; means for generating a set point signal corresponding to a predetermined angle of rotation; means for detecting when the amplitude of each of said sawtooth waveforms reaches a level defined by said set point signal so as to correspond to a predetermined angle of rotation of said power shaft; means responsive to said detecting means for generating an engine trigger signal corresponding in time to a predetermined angle of rotation of said power shaft; aNd means for adjusting said set point signal so as to adjust the timing of said engine trigger signal to correspond with a different predetermined angle of rotation.
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) | 1978-05-26 | 1978-11-25 | 1979-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-26 | 1982-11-25 | 1983-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-26 | 1986-11-25 | 1987-05-27 | $7700.00 | Window Closed / Lapsed |