| 摘要 |
PROBLEM TO BE SOLVED: To improve engine startability by sharply shortening residual fuel replacing time of a fuel system. SOLUTION: Two fuel pumps 7A and 7B are switched in series and in parallel. Valve opening pressure of a pressure regulating relief valve 21 is also switched in two stages of high pressure and low pressure. When starting an engine, the fuel pumps 7A and 7B are operated in parallel, the valve opening pressure of the relief valve 21 is set to low pressure, and residual fuel of a supply pipe 2 and a fuel gallery 3 is replaced in a short period of time with fuel of low pressure and a large flow rate. Next, the fuel pumps 7A and 7B are operated in series, the valve opening pressure of the relief valve 21 is set to high pressure, and the fuel of high pressure and a small flow rate is injected in a liquid phase from a fuel injection valve 4. |
