Denso Corporation

Kenta Kyouda

Satoru Nakayama

Makoto Toriyama

Kaori Doi

Naoto Hayashi

Kanechiyo Terada

Kenechiyo Terada

An ignition apparatus inputs energy during a predetermined energy input period after the interruption of a primary electric current by an ignition switch and a discharge of an ignition plug caused by a secondary electric current. Moreover, the ignition apparatus includes a blow-off detection unit that detects, during the energy input period IGW after the start of the discharge by the ignition plug, occurrence of blow-off of the discharge. When the secondary electric current Idrops below a blow-off detection electric current threshold value Ibo at a time instant tbo in a 'second region' where it is impossible to perform a re-discharge after blow-off, the blow-off detection unit determines that blow-off has occurred and the ignition apparatus stops the energy input from an energy input unit to an ignition coil. By preventing unnecessary energy input, it is possible to suppress unnecessary electric power consumption and wear of electrodes of the ignition plug.

Ignition apparatus

An ignition apparatus includes a blow-off determining unit. The blow-off determining unit determines, when a secondary electric current drops below a predetermined threshold value Ia during a determination period, that blow-off has occurred; the determination period is a predetermined time period &#x394;T from the start of a spark discharge by a main ignition circuit. Further, when it is determined that blow-off has occurred during a main ignition (full-transistor ignition), it is controlled to perform a continuing spark discharge after the main ignition in a next cycle. Moreover, a secondary electric current command value Iin performing the continuing spark discharge is set to an electric current value that is obtained by adding a predetermined electric current value &#x3b1; to the predetermined threshold value Ia used in the blow-off determination. Consequently, in the next cycle, it is possible to reliably prevent blow-off, thereby reliably preventing a misfire.

Ignition apparatus for internal combustion engine

Growing community of inventors

Kariya, Japan

Kenta Kyouda