Knock detecting apparatus for an internal combustion engine
AssigneeNippon Soken, Inc.
InventorsHiroaki Yamaguchi, Tadashi Hattori, Yoshinori Ootsuka
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Abstract
The vibrations produced by the knocking in an engine and having frequencies in different frequency bands are detected by a vibration detector having a plurality of resonance frequencies. One of the detection outputs of the vibration detector is selected by a switching circuit or a filter circuit in accordance with the operating conditions of the engine. The ignition timing of the engine is corrected in accordance with the selected detection output.
Claims6
A knock detecting apparatus for an internal combustion engine in which a combustible mixture is ignited by an ignition spark and ignition control means for controlling a timing of said ignition spark, said detecting apparatus comprising:
- first means responsive to knocks of said engine at around a predetermined first frequency and effective to produce a first knock output signal indicative of said engine knocks;
- second means responsive to knocks of said engine at around a predetermined second frequency and effective to produce a second knock output signal indicative of said engine knocks, said second frequency being lower than said first frequency;
- means responsive to an operating condition of said engine and effective to produce a condition output signal indicative of said operating condition;
- and
- means responsive to said condition output signal and effective to selectively apply one of said first and second output signals to said ignition control means to thereby control said timing of ignition spark, said first and second output signals being selected in response to said condition output signals being selected in response to said condition output signal indicating that said operating condition is higher and lower than a predetermined reference value, respectively.
Dependencies are inferred from the claim text.