Knock suppression apparatus for an internal combustion engine

A knock suppression apparatus for an internal combustion engine comprising:

• knock sensing means for sensing knocking of an engine;
• light load sensing means for sensing when the engine is operating under a light load;
• basic ignition timing calculating means for calculating a basic ignition timing based on an operating condition of the engine;
• lag angle calculating means responsive to the knock sensing means for calculating a lag angle when knocking is sensed;
• lag angle correcting means responsive to the light load sensing means for decreasing the lag angle from an initial value calculated by the lag angle calculating means to a new value in a plurality of steps to provide a corrected lag angle when the light load sensing means senses that the engine is operating under a light load;
• and
• final ignition timing calculating means for calculating a final ignition timing for the engine based on the basic ignition timing and the corrected lag angle.

A knock suppression apparatus for an internal combustion engine comprising:

• knock sensing means for sensing knocking of an engine;
• load sensing means for sensing a transition of a load of the engine between a light load region and a heavy load region;
• basic ignition timing calculating means for calculating a basic ignition timing based on an operating condition of the engine;
• lag angle calculating means responsive to the knock sensing means for calculating a lag angle when knocking is sensed;
• weighting means responsive to the load sensing means for producing a weighting factor and multiplying the lag angle by the weighting factor to obtain a corrected lag angle and for changing the weighting factor from its value prior to the transition to a new value no earlier than 1 second after the transition;
• final ignition timing calculating means for calculating a final ignition timing for the engine based on the basic ignition timing and the corrected lag angle;
• and
• means for controlling the engine according to the final ignition timing.

A knocking suppression method for an internal combustion engine comprising:

• sensing knocking of an engine;
• sensing a transition of a load on the engine between first and second load regions;
• calculating a basic ignition timing based on an operating condition of the engine;
• calculating a lag angle for the engine when knocking is sensed;
• calculating a weighting factor and multiplying the lag angle by the weighting factor to obtain a corrected lag angle;
• changing the weighting factor upon sensing of a load transition from its value prior to the transition to a new value in a plurality of steps;
• calculating a final ignition timing for the engine based on the basic ignition timing and the corrected lag angle;
• and
• controlling the engine according to the final ignition timing.