METHOD FOR JUDGING COMBUSTION CONDITION IN INTERNAL COMBUSTION ENGINE

• Main Authors: ENKAI HIROSHI, SUGIZAKI SHINOBU, IZUMI MITSUHIRO, ASANO MORIHITO, TAKAHASHI KOICHI
• Format: Patent
• Language: English
• Published: 01.10.2009
• Subjects: BLASTING; COMBUSTION ENGINES; CONTROLLING COMBUSTION ENGINES; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; IGNITION, OTHER THAN COMPRESSION IGNITION, FORINTERNAL-COMBUSTION ENGINES; LIGHTING; MECHANICAL ENGINEERING; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES; WEAPONS

PROBLEM TO BE SOLVED: To prevent misjudgment of a combustion condition detection by including the time of after-burning not contributing torque, in a method for judging the combustion condition in an internal combustion engine detecting ion current in a combustion chamber and judging the combustion condition based on a period during which detected ion current is not less than threshold. SOLUTION: In this method for judging the combustion condition, main combustion time atdc during which ion current based on main combustion generated at first after ignition is not less than threshold, whole elapsed time atdcmax during which ion current based on the last one of after-burning generated after main combustion is not less than threshold, and combustion retention time atdcint adding the main combustion time and time integrating a period during which ion current based on whole after-burning generated after main combustion from measurement start are measured respectively (S1). If ratio of a product of whole elapsed time to combustion retention time is less than a prescribed value, whole elapsed time is selected as a criterion for determining the combustion condition. If ratio of the whole elapsed time to the combustion retention period exceeds the prescribed value, main combustion time is selected as the criterion for determining the combustion condition. COPYRIGHT: (C)2010,JPO&INPIT