US4368635A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Knocking detector
Assignee: Nissan Motor Co Ltd
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Filing: 1980-12-02
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Granted: 1983-01-18
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Expires: 2000-12-02
Abstract
Abstract A knocking detector senses engine vibration and produces an electrical signal corresponding to such vibration. This signal is then rectified and smoothed to produce a background noise signal. When the magnitude of the background noise level signal is greater than a reference value, the amplitude of the rectified signal is limited so that the background noise level signal has a substantially constant level. This limited background noise level signal is then compared with the initial signal from the sensor, and if the initial signal from the sensor is greater in magnitude than the background noise signal, the engine is considered to be in knocking condition.
Inventors
- 👤 Kenichi Yoshida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:39
CPC Classifications
F; F02; F02P; F02P5/00; F02P5/04; F02P5/145; F02P5/15; F02P5/152; G; G01; G01L; G01L23/00; G01L23/22; G01L23/221; G01L23/225; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/40
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
147 words
A knocking detector for use with an internal combustion engine, comprising: (a) means for sensing engine vibration and producing a first input signal indicative thereof; (b) means for rectifying the first input signal and producing a second rectified input signal; (c) means for smoothing the second rectified input signal to produce a background noise level signal; (d) first comparing means for comparing the magnitude of the background noise level signal to a predetermined reference value; (e) means responsive to the first comparing means for limiting the amplitude of the second rectified input signal when the amplitude of the background noise level signal is greater than said predetermined reference value; and (f) second comparing means for comparing said first input signal to the background noise level signal and generating a knocking indication signal when said first input signal is greater in magnitude than the background noise level signal.
Claim 2
Dependent Claim
147 words
A knocking detector for use with an internal combustion engine, comprising: (a) means for sensing engine vibration and producing a first input signal indicative thereof; (b) means for rectifying the first input signal and producing a second rectified input signal; (c) means for smoothing the second rectified input signal to produce a background noise level signal; (d) first comparing means for comparing the magnitude of the background noise level signal to a predetermined reference value; (e) means responsive to the first comparing means for limiting the amplitude of the second rectified input signal when the amplitude of the background noise level signal is greater than said predetermined reference value; and (f) second comparing means for comparing said first input signal to the background noise level signal and generating a knocking indication signal when said first input signal is greater in magnitude than the background noise level signal.
Claim 3
Dependent Claim
65 words
The knocking detector according to claim 1, wherein said limiting means includes first amplifying means disposed between said rectifying means and said smoothing means, said amplifying means including a first operational amplifier, a feedback circuit comprising a resistor connecting the input and output of said amplifier, and means for controlling the resistance of said feedback circuit responsive to the output of said first comparing means.
Claim 4
Dependent Claim
72 words
The knocking detector according to claim 2, wherein said controlling means includes a transistor connecting the output and input of said amplifier, an analog switch for supplying therethrough said second rectified input signal to said transistor to render the same conductive or non-conductive, and wherein said analog switch is connected to the output of said first comparing means whereby said first comparing means is operative to close or open said analog switch.
Claim 5
Dependent Claim
92 words
The knocking detector according to claim 2, wherein said controlling means includes a transistor connecting the output and input of said amplifier, and wherein said first comparing means comprises a second operational amplifier for receiving the output of said smoothing means, a feedback circuit comprising a resistor and a diode connected in parallel and connecting the input and output of said second amplifier for outputting an output to turn on said transistor when the input to said second amplifying means is higher than a predetermined reference level to render said transistor conductive.
Claim 6
Dependent Claim
26 words
The knocking detector according to any of claims 1 to 4, further including third amplifying means disposed between said smoothing means and said second comparing means.
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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) | 1986-01-17 | 1986-07-19 | 1987-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-01-17 | 1990-07-19 | 1991-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-01-17 | 1994-07-19 | 1995-01-18 | $7700.00 | Window Closed / Lapsed |