FUEL INJECTION CONTROL METHOD FOR SPARK IGNITION-TYPE COMBUSTION ENGINE, AND FUEL INJECTION DEVICE

摘要

According to the present invention, in a spark ignition-type combustion engine (1) provided with a fuel injection device that performs multi-stage injection, the fuel temperature at a distal end section of a fuel injection valve (10) is estimated from a cooling water temperature and the like (S1), and whether flash boiling is occurring is determined from the fuel temperature and intake pressure (S2). When the fuel temperature is high, flash boiling occurs in which fuel in a nozzle hole rapidly boils and vaporizes. Since PN degrades as the number of injections per cycle increases, the number of injections is corrected to a smaller number when it is determined that flash boiling is occurring. Accordingly, PN degradation that accompanies flash boiling is suppressed.