Ignition timing control appartaus for an internal combustion engine

Abstract

An ignition timing control apparatus for an internal combustion engine includes a pressure detector for detecting an inner pressure of cylinder of the engine, a crank angle detector for detecting a crank angle of the engine, and a control device which receives the detection signals of the pressure detector and the crank angle detector so that an effective calorific value Q of fuel in one ignition cycle and an effective combustion rate K of fuel or a low level calorific value Hu of fuel are calculated on the basis of an inner pressure of cylinder P(.theta.) at a crank angle in compression and expansion strokes in the one ignition cycle, the crank angle .theta. and a cylinder capacity V(.theta.). Ignition timing is controlled based on at least one of the effective calorific value Q and the effective combustion rate K.

Dependencies are inferred from the claim text.