Method of and apparatus for controlling the ignition timing of an internal combustion engine

Claim 1

A method of controlling the ignition timing of an internal combustion engine having an intake manifold, said method comprising the steps of: detecting one of the flow rate of air sucked into the engine and the pneumatic pressure in the intake manifold, and producing a first electrical signal related thereto; detecting the rotational speed of the engine and producing a second electrical signal related thereto; calculating, in response to said first and second electrical signals, a spark advance angle which represents an optimum ignition timing at the operating condition corresponding to the detected flow rate of air or the detected pneumatic pressure and to the detected rotational speed; detecting the temperature of air sucked into the engine to produce a third electrical signal which indicates the detected intake air temperature; correcting, in response to said second and third electrical signals, said calculated spark advance angle, said correcting step including the steps of increasing said calculated spark advance angle by a variable value when the detected intake air temperature is lower than a predetermined temperature, and decreasing said calculated spark advance angle by a variable value when the detected intake air temperature is higher than the predetermined temperature, said variable value changing depending upon the difference between the detected intake air temperature and the predetermined temperature and upon the detected rotational speed indicated by the second electrical signal; and controlling the timing of the sparks applied to the engine depending upon said spark advance angle.

Claim 2

A method of controlling the ignition timing of an internal combustion engine having an intake manifold, said method comprising the steps of: detecting one of the flow rate of air sucked into the engine and the pneumatic pressure in the intake manifold, and producing a first electrical signal related thereto; detecting the rotational speed of the engine and producing a second electrical signal related thereto; calculating, in response to said first and second electrical signals, a spark advance angle which represents an optimum ignition timing at the operating condition corresponding to the detected flow rate of air or the detected pneumatic pressure and to the detected rotational speed; detecting the temperature of air sucked into the engine to produce a third electrical signal which indicates the detected intake air temperature; correcting, in response to said second and third electrical signals, said calculated spark advance angle, said correcting step including the steps of increasing said calculated spark advance angle by a variable value when the detected intake air temperature is lower than a predetermined temperature, and decreasing said calculated spark advance angle by a variable value when the detected intake air temperature is higher than the predetermined temperature, said variable value changing depending upon the difference between the detected intake air temperature and the predetermined temperature and upon the detected rotational speed indicated by the second electrical signal; and controlling the timing of the sparks applied to the engine depending upon said spark advance angle.

Claim 6

A method of controlling the ignition timing of an internal combustion engine, said method comprising the steps of: detecting the flow rate of air sucked into the engine and producing a first electrical signal which indicates the detected flow rate of air; detecting the rotational speed of the engine and producing a second electrical signal which indicates the detected rotational speed; detecting the temperature of air sucked into the engine and producing a third electrical signal which indicates the detected intake air temperature; correcting, in response to said third electrical signal, said detected flow rate of air and producing a fifth electrical signal which indicates the corrected flow rate of air; detecting the load condition of the engine and producing a fourth electrical signal which indicates the detected load condition; discriminating, in response to the fourth electrical signal, whether the detected load condition is lighter than a predetermined load condition or not, to perform said correcting step only when the detected load condition is lighter than the predetermined load condition; calculating, in response to said fifth and second electrical signals, a spark advance angle which represents an optimum ignition timing at the operating condition corresponding to the corrected flow rate of air and to the detected rotational speed; and controlling the timing of the sparks applied to the engine depending upon said spark advance angle.

Claim 7

A method of controlling the ignition timing of an internal combustion engine, said method comprising the steps of: detecting the flow rate of air sucked into the engine and producing a first electrical signal which indicates the detected flow rate of air; detecting the rotational speed of the engine and producing a second electrical signal which indicates the detected rotational speed; detecting the temperature of air sucked into the engine and producing a third electrical signal which indicates the detected intake air temperature; correcting, in response to said third electrical signal, said detected flow rate of air and producing a fifth electrical signal which indicates the corrected flow rate of air; detecting the load condition of the engine and producing a fourth electrical signal which indicates the detected load condition; discriminating, in response to the fourth electrical signal, whether the detected load condition is lighter than a predetermined load condition or not, to perform said correcting step only when the detected load condition is lighter than the predetermined load condition; calculating, in response to said fifth and second electrical signals, a spark advance angle which represents an optimum ignition timing at the operating condition corresponding to the corrected flow rate of air and to the detected rotational speed; and controlling the timing of the sparks applied to the engine depending upon said spark advance angle.

Claim 17

A method of controlling the ignition timing of an internal combustion engine having an intake manifold, said method comprising the steps of: detecting one of the flow rate of air sucked into the engine and the pneumatic pressure in the intake manifold, and producing a first electrical signal related thereto; detecting the rotational speed of the engine and producing a second electrical signal related thereto; calculating, in response to said first and second electrical signals, a spark advance angle which represents an optimum ignition timing at the operating condition corresponding to the detected flow rate of air or the detected pneumatic pressure and to the detected rotational speed; detecting the temperature of air sucked into the engine to produce a third electrical signal which indicates the detected intake air temperature; correcting, in response to said second and third electrical signals, said calculated spark advance angle, said correcting step including the steps of increasing said calculated spark advance angle by a variable value when the detected intake air temperature is higher than a predetermined temperature, and decreasing said calculated spark advance angle by a variable value when the detected intake air temperature is lower than the predetermined temperature, said variable value changing depending upon the difference between the detected intake air temperature and the predetermined temperature and upon the detected rotational speed indicated by the second electrical signal; and controlling the timing of the sparks applied to the engine depending upon said spark advance angle.

Claim 18

A method of controlling the ignition timing of an internal combustion engine having an intake manifold, said method comprising the steps of: detecting one of the flow rate of air sucked into the engine and the pneumatic pressure in the intake manifold, and producing a first electrical signal related thereto; detecting the rotational speed of the engine and producing a second electrical signal related thereto; calculating, in response to said first and second electrical signals, a spark advance angle which represents an optimum ignition timing at the operating condition corresponding to the detected flow rate of air or the detected pneumatic pressure and to the detected rotational speed; detecting the temperature of air sucked into the engine to produce a third electrical signal which indicates the detected intake air temperature; correcting, in response to said second and third electrical signals, said calculated spark advance angle, said correcting step including the steps of increasing said calculated spark advance angle by a variable value when the detected intake air temperature is higher than a predetermined temperature, and decreasing said calculated spark advance angle by a variable value when the detected intake air temperature is lower than the predetermined temperature, said variable value changing depending upon the difference between the detected intake air temperature and the predetermined temperature and upon the detected rotational speed indicated by the second electrical signal; and controlling the timing of the sparks applied to the engine depending upon said spark advance angle.