Patent US4426975A successfully refreshed from Google Patents.
US4426975A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ignition timing control system for internal combustion engines
Assignee: Denso Corp
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Filing: 1981-11-18
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Granted: 1984-01-24
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Expires: 2001-11-18
Abstract
Abstract In response to the occurrence of knocking in an internal combustion engine, the basic ignition timing is corrected in a direction to retard it through the charging and discharging of an integrator circuit. The integrated current output of the integrator circuit is varied in accordance with a voltage corresponding to the speed of the engine so as to limit the maximum amount of ignition timing retard at low speeds or high speeds of the engine.
Inventors
- 👤 Shosuke Suzuki
- 👤 Teruyoshi Ito
- 👤 Yukio Sakakibara
- 👤 Takashi Yamada
- 👤 Fumiyoshi Kubo
- 👤 Kunimasa Yoshimura
- 👤 Mitsuyuki Ugajin
- 👤 Kiyokane Kaji
- 👤 Mitsuyuki Banno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:31
CPC Classifications
F; F02; F02P; F02P5/00; F02P5/04; F02P5/145; F02P5/15; F02P5/152; F02P5/1523; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/40
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
224 words
In an ignition timing control system, for internal combustion engines comprising knocking detecting means for detecting the occurrence of knocking in said engine, a knocking discrimination circuit responsive to an output signal of said knocking detecting means to determine the occurrence of knocking and generate a rectangular pulse in response to each knocking event, an ignition timing control circuit responsive to the occurrence of said knocking to adjust a basic ignition timing established in accordance with an operating condition of said engine, and ignition means responsive to an output signal of said ignition timing control circuit to effect ignition of said engine, the improvement wherein said ignition timing control circuit comprises: speed sensor means for detecting a speed of said engine, and generating an engine speed signal, a pair of constant current circuits operated by a signal from said speed sensor means, an integrator circuit whose charge and discharge are controlled by said pair of constant current circuits, means for outputting a voltage corresponding to the output signal of said knocking detecting means, said outputting means controlling the output current of one of said constant current circuits according to the knocking state, and means for limiting the output current of one of said constant current circuits by limiting the output voltage of said outputting means according to a signal from said speed sensor means.
Claim 2
Dependent Claim
224 words
In an ignition timing control system, for internal combustion engines comprising knocking detecting means for detecting the occurrence of knocking in said engine, a knocking discrimination circuit responsive to an output signal of said knocking detecting means to determine the occurrence of knocking and generate a rectangular pulse in response to each knocking event, an ignition timing control circuit responsive to the occurrence of said knocking to adjust a basic ignition timing established in accordance with an operating condition of said engine, and ignition means responsive to an output signal of said ignition timing control circuit to effect ignition of said engine, the improvement wherein said ignition timing control circuit comprises: speed sensor means for detecting a speed of said engine, and generating an engine speed signal, a pair of constant current circuits operated by a signal from said speed sensor means, an integrator circuit whose charge and discharge are controlled by said pair of constant current circuits, means for outputting a voltage corresponding to the output signal of said knocking detecting means, said outputting means controlling the output current of one of said constant current circuits according to the knocking state, and means for limiting the output current of one of said constant current circuits by limiting the output voltage of said outputting means according to a signal from said speed sensor means.
Claim 3
Dependent Claim
38 words
An ignition timing control system according to claim 1, wherein said integrator circuit saturates at a predetermined charge level, and so that a maximum amount of ignition timing retard is then established by said ignition timing control circuit.
Claim 4
Dependent Claim
46 words
An ignition timing control system according to claim 1, wherein said speed sensor means comprises angular position sensing means including an electromagnetic pickup attached to said engine, and a waveform reshaping circuit for reshaping an output of said angular position sensing means to a rectangular waveform.
Claim 5
Dependent Claim
52 words
An ignition timing control system according to claim 1, wherein said ignition timing control circuit further includes a function generator responsive to an output of said speed sensor means to generate an analog output having a characteristic such that said analog voltage decreases linearly with increase in the speed of said engine.
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) | 1987-01-23 | 1987-07-25 | 1988-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-23 | 1991-07-25 | 1992-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-23 | 1995-07-25 | 1996-01-24 | $7700.00 | Window Closed / Lapsed |