Approach for controlling fuel flow with alternative fuels
First Claim
Patent Images
1. A method for a vehicle fuel delivery system comprising an internal combustion engine, the internal combustion engine having at least one cylinder having a piston, the internal combustion engine further having valved fuel injectors comprising:
- opening a first solenoid valve positioned downstream of a first fuel pump and upstream of a port of a fuel rail, closing a second solenoid valve positioned downstream of an ejector and upstream of a first tank, adjusting a state of a third three-way solenoid valve positioned upstream of the port of the fuel rail, downstream of the first fuel pump, and downstream of a second fuel pump to direct a first fuel from the first tank to the port of the fuel rail via a passage in a first direction during a first mode, the first pump operating and the second pump not operating during the first mode;
closing the first and second valves and adjusting the state of the third valve to direct a second fuel from a second tank to the port of the fuel rail via the passage in the first direction during a second mode, the second pump operating and the first pump not operating during the second mode; and
closing the first valve, opening the second valve, and adjusting the state of the third valve to direct whichever fuel is in the fuel rail from the port of the fuel rail via the passage in a second direction, opposite the first direction, to the first tank during a vehicle shut-off condition, the first pump operating and the second pump not operating during the vehicle shut-off condition.
1 Assignment
0 Petitions
Accused Products
Abstract
Fuel systems for supplying fuel to an engine are described. In one example, fuel is evacuated from a fuel rail upon vehicle shut-off by directing fuel from a fuel pump to provide a motive flow for an ejector to pump fuel from the fuel rail to a fuel tank.
-
Citations
20 Claims
-
1. A method for a vehicle fuel delivery system comprising an internal combustion engine, the internal combustion engine having at least one cylinder having a piston, the internal combustion engine further having valved fuel injectors comprising:
-
opening a first solenoid valve positioned downstream of a first fuel pump and upstream of a port of a fuel rail, closing a second solenoid valve positioned downstream of an ejector and upstream of a first tank, adjusting a state of a third three-way solenoid valve positioned upstream of the port of the fuel rail, downstream of the first fuel pump, and downstream of a second fuel pump to direct a first fuel from the first tank to the port of the fuel rail via a passage in a first direction during a first mode, the first pump operating and the second pump not operating during the first mode; closing the first and second valves and adjusting the state of the third valve to direct a second fuel from a second tank to the port of the fuel rail via the passage in the first direction during a second mode, the second pump operating and the first pump not operating during the second mode; and closing the first valve, opening the second valve, and adjusting the state of the third valve to direct whichever fuel is in the fuel rail from the port of the fuel rail via the passage in a second direction, opposite the first direction, to the first tank during a vehicle shut-off condition, the first pump operating and the second pump not operating during the vehicle shut-off condition. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A system for controlling fuel flow in a vehicle comprising an internal combustion engine, the internal combustion engine having at least one cylinder having a piston, the internal combustion engine further having valved fuel injectors comprising:
-
a fuel rail with a fuel port; a first fuel stage comprising; a first fuel tank for storing fuel of a first fuel type; a first fuel pump operable to pump fuel from the first fuel tank to the fuel rail via a fuel supply line, the first fuel pump coupled outside the first fuel tank; a first solenoid valve positioned downstream of the first fuel pump; a first fuel return line positioned upstream from the fuel rail and downstream from the first valve; an ejector positioned in the first fuel return line, a first inlet of the ejector coupled to the first fuel return line; a second solenoid valve positioned between an outlet of the ejector and the first fuel tank; and a motive flow line connected between a second inlet of the ejector and the outlet of the ejector, the second inlet of the ejector coupled between an outlet of the first fuel pump and the first valve, the first fuel pump further operable to pump fuel from the first fuel tank into the second inlet of the ejector to provide a motive flow for the ejector; a second fuel stage comprising; a second fuel tank for storing fuel of a second fuel type different from the first fuel type; and a second fuel pump operable to pump fuel from the second fuel tank to the fuel rail; and a third three-way solenoid valve positioned upstream of the fuel port of the fuel rail between the first fuel stage and the second fuel stage, the ejector positioned outside the first and second fuel tanks, the third valve controlling fuel flow into and out of the fuel port of the fuel rail; wherein fuel of whichever type is in the fuel rail is directed from the fuel rail to the first fuel tank via the fuel supply line during a vehicle shut-off condition. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20)
-
Specification