Patent ID: 6571769
Filing Date: 2003-06-03
Classification: F02N,F02P

Abstract:
A capacitor discharge type internal combustion engine ignition device comprising: an exciter coil provided inside a magneto-generator to be driven by an internal combustion engine; an ignition coil; an ignition capacitor provided in the primary side of said ignition coil and charged by a positive half-wave output voltage of said exciter coil at one polarity; a discharge thyristor to become an on-state when an ignition signal is given to allow a charge of said ignition capacitor to discharge through the primary coil of said ignition coil; a control power supply circuit for converting the output voltage of said exciter coil into a direct current voltage; a signal generating portion for generating a reference position detection signal at a reference position set at a position sufficiently advanced more than a rotational angle position of a crank shaft which corresponds to a top dead center of said internal combustion engine and generating an ignition position detection signal for extremely low speed state at the position adequate as the ignition position at the starting time and the extremely low speed state of said internal combustion engine; an ignition control portion for extremely low speed state for giving the ignition signal to said discharge thyristor when said ignition position detection signal for extremely low speed state is generated; and an ignition control portion for steady state for giving the ignition signal to said discharge thyristor at the ignition position decided based on rotational information on the internal combustion engine obtained from the output signal of said signal generating portion; wherein said ignition control portion for extremely low speed state and said ignition control portion for steady state are comprised in such a manner as to operate with the direct current power supply voltage obtained from said control power supply circuit,wherein said control power supply circuit comprises: a first power supply circuit for generating a constant direct current power supply voltage to allow said ignition control portion for steady state to operate when the output voltage of said exciter coil exceeds a set value and a second power supply circuit for generating the direct current power supply voltage to allow said ignition control portion for extremely low speed state to operate since when the output voltage of said exciter coil is put into a state of being below said set value, and wherein said ignition control portion for extremely low speed state is comprised in such a manner as to start generating said ignition signal when the voltage lower than the power supply voltage of said ignition control portion for steady state is given.