Apparatus for determining characteristic of fuel supplied to fuel injection system, calculates kinematic viscosity of fuel based on density of fuel

摘要

A fuel pressure sensor (20) detects fuel pressure in fuel passage, and electronic control unit (ECU) (30) receives pressure waveform representing variation in fuel pressure based on detected fuel pressure, when fuel injector (10) injects fuel. The ECU calculates velocity of pressure wave which forms pressure waveform based on pulsation of pressure waveform, and fuel passage length. The density of fuel is calculated based on velocity of pressure wave. A kinematic viscosity of fuel is determined according to density of fuel to determine fuel characteristic. An independent claim is included for fuel characteristic determination method.