Patent Document ID: 20120158268
Application ID: 13325531
Patent Flag: 0

Claim One:
1. A fuel-injection-characteristics learning apparatus which learns a fuel-injection-characteristic value of a fuel injection system, the fuel injection system includes: a fuel injector injecting the high-pressure fuel accumulated in the accumulator through a fuel injection port; a memory portion storing a fuel-injection characteristics which the fuel injector individually has; and a fuel injection command portion generating a fuel-injection command signal based on the fuel-injection characteristics, the fuel-injection characteristics learning apparatus comprising: a fuel pressure sensor provided in a fuel passage fluidly connecting the accumulator and the fuel injection port, the fuel pressure sensor detecting a fuel pressure in the fuel passage; a characteristic-value detecting portion analyzing a fuel injection condition based on a fuel pressure waveform which represents a variation in a detection value of the fuel pressure sensor, the fuel-injection characteristic detecting portion detecting the fuel-injection-characteristic value based on the analyzed fuel injection condition; a fuel temperature sensor detecting a fuel temperature; and a learning portion storing the fuel-characteristics in the memory portion in association with the fuel temperature detected by the fuel temperature sensor.