초록 ▼

In a high pressure fuel injection system, fuel is pumped up from a fuel tank by a low pressure pump and further pressurized by a high pressure pump. Pressurized fuel is accumulated in a common rail connected to injectors which inject fuel into an engine. A high pressure regulator is connected to the

In a high pressure fuel injection system, fuel is pumped up from a fuel tank by a low pressure pump and further pressurized by a high pressure pump. Pressurized fuel is accumulated in a common rail connected to injectors which inject fuel into an engine. A high pressure regulator is connected to the common rail to mechanically relieve excessive fuel pressure in the common rail or to electronically reduce the fuel pressure when required. An electronic control unit controls operation of the high pressure pump, the high pressure regulator and the injectors according to engine operating conditions which are fed to the unit from various sensors. The fuel pressure in the common rail is decreased by operation of the high pressure pump and the high pressure regulator either rapidly or gradually according to engine operating conditions. Vapor, including fuel and air, accumulated in the common rail under high ambient temperature is purged out quickly before the engine is stared by driving only the low pressure pump under command from the electronic control unit. The system is also provided with a "limp-home" function under which a car is driven back home even when some portions of the system fail or malfunction.

대표청구항 ▼

[ What is claimed is:] [1.] A high pressure fuel injection system for an internal combustion engine comprising:a low pressure fuel source;a high pressure fuel supply pump, connected to the fuel source, for pressurizing fuel from the fuel source;a common rail, connected to the high pressure fuel supp

[ What is claimed is:] [1.] A high pressure fuel injection system for an internal combustion engine comprising:a low pressure fuel source;a high pressure fuel supply pump, connected to the fuel source, for pressurizing fuel from the fuel source;a common rail, connected to the high pressure fuel supply pump, for accumulating therein pressurized fuel sent from the high pressure fuel supply pump;injectors, connected to the common rail, for injecting fuel into the internal combustion engine;a high pressure regulator including a mechanical pressure regulator and an electromagnetic pressure regulator, connected to the common rail, for relieving fuel pressure in the common rail and returning fuel to the low pressure fuel source; andan electronic control unit for controlling operation of the high pressure fuel supply pump, the injectors and the electromagnetic pressure regulator according to engine operating conditions; whereinfuel volume from said high pressure fuel supply pump is controlled by the electronic control unit to produce a predetermined fuel pressure in said common rail;fuel pressure in the common rail is decreased by controlling the electromagnetic regulator and the high pressure fuel supply pump upon such request from the electronic control unit, andwherein the fuel pressure in the common rail is rapidly decreased by opening a valve of the electromagnetic pressure regulator upon such request from the electronic control unit.