| 摘要 |
PROBLEM TO BE SOLVED: To precisely learn an operation characteristic of a fuel injection valve in an execution area of main injection, in a device which performs multistage injection.SOLUTION: A fuel injection characteristic learning device comprises a pressure sensor which detects fuel pressure in a fuel supply system, and is used in an internal combustion engine which performs fuel injection from a fuel injection valve in one combustion cycle by multistage injection. A plurality of learning areas which are partitioned per fuel injection amount are set, and the operation characteristic is learnt at each area. In an area in which the fuel injection amounts in a plurality of learning areas are small, the operation characteristic is learnt on the basis of the fuel pressure which is detected by the pressure sensor at the top-stage execution of pilot injection (S13, S15). In an area in which the fuel injection amounts in a plurality of the learning areas are large, the operation characteristic is learnt on the basis of the fuel pressure which is detected by the pressure sensor at the execution of main injection (S18, S19). |
