| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a fuel supply device capable of detecting fuel density also immediately after start of an engine in a simpler method. <P>SOLUTION: During cranking of the engine, fuel pressure PF is sampled (S17), and by performing high-speed Fourier transform, frequency components of the sampled fuel pressure PF are calculated and pulsation natural frequency f0 of fuel inside a fuel supply system is calculated (S21). As fuel density ρF increases, the pulsation natural frequency f0 decreases. Therefore, based on the pulsation natural frequency f0, fuel density ρF is determined (S22). At that time, fuel temperature TF is detected (S20), and by correcting the fuel density ρF determined based on the pulsation natural frequency f0 by the fuel temperature TF, fuel density ρF at reference temperature TFREF is obtained. In accordance with the fuel density ρF, a mixture ratio RMIX of the fuel is calculated (S23). <P>COPYRIGHT: (C)2008,JPO&INPIT |
