Ignition timing control apparatus for engine

Claim 1

An apparatus for controlling the timing of ignition in an engine, comprising: means for detecting knocking in the engine; means for computing a cumulative correction value from the detected knocking; a running mode sensor for detecting the running mode of the engine; means for producing a reference control value of the basis of a reference ignition timing characteristic corresponding to the running mode of the engine; memory means for storing corrective control values corresponding to the individual running modes of the engine and, in response to the information from said running mode sensor representative of one running mode, outputting the corrective control value corresponding to said information; renewal control means operated after periods of steady running conditions extending over a plurality of ignition cycles for renewing the corrective control value in the memory means corresponding to the present running mode in accordance with the cumulative correction value so that said control value is changed in the direction of angular advance for ignition upon detection of no knocking and is changed in the direction of angular delay for ignition upon detection of knocking with a corresponding adjustment in the cumlative correction value; means for computing an ignition-timing corrective control quantity according to the corrective control value read out from said memory means and the cumulative correction value; timing converter means for determining the ignition timing on the basis of said ignition-timing corrective control quantity and said reference control valve; and abnormality detecting means capable of detecting occurrence of an abnormality in said knock detecting means and, upon detection of any abnormality, prohibiting said renewal control means for renewing the stored value.

Claim 2

An apparatus for controlling the timing of ignition in an engine, comprising: means for detecting knocking in the engine; means for computing a cumulative correction value from the detected knocking; a running mode sensor for detecting the running mode of the engine; means for producing a reference control value of the basis of a reference ignition timing characteristic corresponding to the running mode of the engine; memory means for storing corrective control values corresponding to the individual running modes of the engine and, in response to the information from said running mode sensor representative of one running mode, outputting the corrective control value corresponding to said information; renewal control means operated after periods of steady running conditions extending over a plurality of ignition cycles for renewing the corrective control value in the memory means corresponding to the present running mode in accordance with the cumulative correction value so that said control value is changed in the direction of angular advance for ignition upon detection of no knocking and is changed in the direction of angular delay for ignition upon detection of knocking with a corresponding adjustment in the cumlative correction value; means for computing an ignition-timing corrective control quantity according to the corrective control value read out from said memory means and the cumulative correction value; timing converter means for determining the ignition timing on the basis of said ignition-timing corrective control quantity and said reference control valve; and abnormality detecting means capable of detecting occurrence of an abnormality in said knock detecting means and, upon detection of any abnormality, prohibiting said renewal control means for renewing the stored value.

Claim 7

An apparatus for controlling the timing of ignition in an engine, comprising: means for detecting knocking in an engine; means for computing a cumulative correction value from the detected knocking; a running mode sensor for detecting the running mode of the engine; means for producing a reference control value on the basis of a reference ignition timing characteristic corresponding to the running mode of the engine; memory means for storing corrective control values corresponding to the individual running modes of the engine and, in response to the information from said running mode sensor representative of one running mode, outputting the corrective value corresponding to said information; renewal control means operated after periods of steady running conditions extending over a plurality of ignition cycles for changing, in the direction of angular delay for ignition, the corrective control value corresponding to the present running mode by the cumulative correction value, and for resetting the cumulative correction value; means for computing an ignition-timing corrective control quantity according to the corrective control value read out from said memory means and the cumulative correction value; timing converter means for determining the ignition timing on the basis of said ignition-timing corrective control quantity and said reference control value; and abnormality detecting means capable of detecting occurrence of an abnormality in said knock detecting means and, upon detection of any abnormality, prohibiting said renewal control means for renewing the stored value; said control-quantity computing means including means which, upon detection of any abnormality by said abnormality detecting means, adds a predetermined quantity of angular delay to the corrective control value read out from said memory means and thereby computes the ignition-timing corrective control quantity.

Claim 8

An apparatus for controlling the timing of ignition in an engine, comprising: means for detecting knocking in an engine; means for computing a cumulative correction value from the detected knocking; a running mode sensor for detecting the running mode of the engine; means for producing a reference control value on the basis of a reference ignition timing characteristic corresponding to the running mode of the engine; memory means for storing corrective control values corresponding to the individual running modes of the engine and, in response to the information from said running mode sensor representative of one running mode, outputting the corrective value corresponding to said information; renewal control means operated after periods of steady running conditions extending over a plurality of ignition cycles for changing, in the direction of angular delay for ignition, the corrective control value corresponding to the present running mode by the cumulative correction value, and for resetting the cumulative correction value; means for computing an ignition-timing corrective control quantity according to the corrective control value read out from said memory means and the cumulative correction value; timing converter means for determining the ignition timing on the basis of said ignition-timing corrective control quantity and said reference control value; and abnormality detecting means capable of detecting occurrence of an abnormality in said knock detecting means and, upon detection of any abnormality, prohibiting said renewal control means for renewing the stored value; said control-quantity computing means including means which, upon detection of any abnormality by said abnormality detecting means, adds a predetermined quantity of angular delay to the corrective control value read out from said memory means and thereby computes the ignition-timing corrective control quantity.