Ignition timing control apparatus for an internal combustion engine

An ignition timing control apparatus for an internal combustion engine comprising:

• a signal rotor rotating in synchronism with a crank shaft of the internal combustion engine;
• a pickup sensor disposed in a confronting relation to said signal rotor to generate an angle signal proportional to rotation of the internal combustion engine;
• ignition signal producing means for calculating an ignition timing on the basis of said angle signal and generating an ignition signal for igniting said internal combustion engine;
• noise duration estimating means for monitoring a parameter representative of a battery voltage and, when a variation amount of said parameter is larger than a predetermined value, estimating on the basis of said variation amount a noise duration during which said angle signal is possibly added noises;
• a mask time memory for storing a plurality of mask times selectable in accordance with an estimated noise duration;
• and
• mask control means for selecting an optimum mask time among said mask times stored in said mask time memory in accordance with the estimated noise duration, and prohibiting said angle signal from entering into said ignition signal producing means for a selected mask time in response to a detection of a predetermined amount variation of said parameter.

An ignition timing control apparatus for an internal combustion engine comprising:

• a signal rotor rotating in synchronism with a crank shaft of the internal combustion engine;
• a pickup sensor disposed in a confronting relation to said signal rotor to generate an angle signal proportional to rotation of the internal combustion engine;
• first ignition signal producing means, operated by a software program, for calculating an ignition timing on the basis of said angle signal and generating a first ignition signal for igniting said internal combustion engine;
• first time mask means for monitoring a parameter representative of a battery voltage, and prohibiting said angle signal from entering into said first ignition signal producing means for a first predetermined time in response to a detection of a predetermined amount fluctuation of said parameter;
• second ignition signal producing means, constituted by hardware components, for generating a second ignition signal for igniting said internal combustion engine;
• second time mask means for prohibiting said angle signal from entering into said second ignition signal producing means for a second predetermined time in response to a first change of said angle signal in an engine start-up condition, said second predetermined time being longer than said first predetermined time;
• and
• mask release means for, when either one of said first and second predetermined times has elapsed, releasing prohibition of entry of said angle signal into said ignition signal producing means corresponding to said either one of said first and second predetermined times.

An ignition timing control apparatus for an internal combustion engine comprising:

• a signal rotor rotating in synchronism with a crank shaft of the internal combustion engine;
• a pickup sensor disposed in a confronting relation to said signal rotor to generate an angle signal proportional to rotation of the internal combustion engine;
• first ignition signal producing means, operated by a software program, for calculating an ignition timing on the basis of said angle signal and generating a first ignition signal for igniting said internal combustion engine;
• noise duration estimating means for monitoring a parameter representative of a battery voltage and, when a variation amount of said parameter is larger than a predetermined value, estimating on the basis of said variation amount a noise duration during which said angle signal is possibly added noises;
• a mask time memory for storing a plurality of mask times selectable in accordance with an estimated noise duration;
• mask control means for selecting an optimum mask time among said mask times stored in said mask time memory in accordance with the estimated noise duration, and prohibiting said angle signal from entering into said first ignition signal producing means for a selected mask time in response to a detection of a predetermined amount variation of said parameter;
• second ignition signal producing means, constituted by hardware components, for generating a second ignition signal for igniting said internal combustion engine;
• time mask means for prohibiting said angle signal from entering into said second ignition signal producing means for a predetermined time in response to a first change of said angle signal in an engine start-up condition, said predetermined time being longer than said selected mask time;
• and
• mask release means for, when either one of said selected mask time and said predetermined time has elapsed, releasing prohibition of entry of said angle signal into said ignition signal producing means corresponding to said either one of said selected mask time and said predetermined time.