| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve fuel economy by optimally controlling fuel pressure by taking into consideration a combustion loss and a driving loss in an engine. Ž<P>SOLUTION: When the intake temperature does not coincide with the reference temperature, a temperature difference Δt between the intake temperature and the reference temperature is calculated (S3), and a fuel pressure correction factor α is set by referring to a fuel pressure temperature correction base table from the temperature difference Δt (S4). When an operation area of the engine is an operation area of uniform combustion or a partial operation area of stratified combustion, target fuel pressure PTGT is corrected by the fuel pressure correction factor α, and is controlled so that delivery pressure of a high pressure fuel pump coincides with the target fuel pressure PTGT. Thus, control is performed so that fuel pressure becomes low when the intake temperature is higher than the reference temperature, and the fuel pressure becomes high when the intake temperature is lower than the reference temperature, and the fuel economy can be improved by reducing an engine loss. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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