| 摘要 |
PURPOSE:To prevent the deterioration of the starting performance of an engine by installing a means for keeping the boost pressure in a control pressure chamber for a certain time even after the stop of the engine operation, into a signal conduit which connects the control pressure chamber of a pressure adjusting valve and a boost pressure taking-out hole. CONSTITUTION:An all-time closed type solenoid valve 22 is installed in the intermediate part of a signal conduit 18 for connecting the boost pressure taking-out port 17 opened in an intake manifold 1 and a control pressure chamber 15 inside a pressure adjusting valve 12. During the engine operation, the signal conduit 18 is set into the conduction state by the solenoid valve 22, and a valve body 20 is opening/closing-operated by the mutual action of the boost pressure (negative pressure) of the engine and the discharge pressure of a fuel pump 9, and the excessive fuel is allowed to circulate into a tank 11. When the engine stops operation, a solenoid valve 22 is closed, and the boost negative pressure is confined into a control pressure chamber 15 for a certain time, and the excessive fuel is allowed to circulate into the tank 11. During this time, the pressure adjusting valve 12 operates to control the discharge pressure of the pump 9 to a relatively low pressure, and therefore, even if the fuel pump 12 inertia-revolves, the leak of oil from injection valves 6 and 7 is prevented, and the deterioration of the warming starting performance can be avoided. |
