| 摘要 |
A novel dual-fuel system for an internal combustion engine is disclosed, that utilizes a single electrically triggerable metering device, in the form of a fuel injector, to supply two distinct fuels to an internal combustion engine, either alternatively or simultaneously. The injector is connected to two separate fuel circuits, each circuit comprising at least a fuel storage tank, a fuel pressure regulator and a fuel rail. In the preferred embodiment, the two fuel rails are coaxial. The two external fuel circuits are fluidically isolated from each other. An arrangement of external valves controls fuel access from the fuel storage tanks to the fuel rails. By selectively activating the external valves, one or both of the two fuels are fed to the injector through one or both of the two separate fuel rails. Inside the injector are two separate fuel paths, fluidically isolated from each other. Each internal fuel path communicates with one of the external fuel circuits. The injector contains at least one electromagnet and at least one fuel flow control valve for each separate fuel path. In the neutral, non-activated position, each valve is resiliently urged against a seat by a return spring. When electrical pulses are fed to the injector, the two valves are simultaneously driven to open off the seat and against the return springs, thereby permitting one or two fuels to pass therethrough and into the engine. The injector meters the quantity of fuel injected into the engine and metering can be achieved either by controlling the fuel flow valve discharge section, or by using a calibrated discharge orifice downstream of the fuel control valve. |
