Fuel pressure control using hysteresis pump drive
First Claim
1. In an automotive vehicle engine having a crankshaft and a fuel injection system with a fuel rail having at least one electrically operated fuel injector for injecting fuel into the engine, a fuel tank for holding liquid fuel, fuel supply means for supplying liquid fuel from the tank to the fuel rail to create pressurized fuel in the fuel rail for the at least one fuel injector, a pressure transducer for sensing the pressure of the pressurized fuel in the fuel rail and generating a pressurized fuel control signal in response thereto, a system for maintaining fuel pressure control comprising:
- a pump that is mechanically coupled in driven relation to the engine crankshaft;
an electric control responsive to various electric signals including said pressurized fuel control signal for generating a pump control signal for controlling the operation of said pump as a function of said various electric signals for maintaining a desired fuel pressure in the fuel rail irrespective of variations in engine speed and torque as the engine operates; and
an electrically-controlled clutch for connecting said pump to the engine crankshaft, said clutch being controlled in accordance with said pump control signal for maintaining said desired fuel pressure in the fuel rail by the extent to which said pump control signal allows power to be transmitted from the engine crankshaft through said clutch to said pump.
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Accused Products
Abstract
Fuel pressure in a deadheaded fuel rail is regulated by an eddy current clutch that forms part of the mechanism that mechanically couples the engine crankshaft with a fuel pump which delivers pressurized fuel to the rail. An electric control that receives several inputs, including engine speed and fuel rail pressure, controls the degree of coupling that is provided by the clutch so that the pressure is regulated even though the engine speed and fuel demand change during normal engine operation.
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Citations
14 Claims
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1. In an automotive vehicle engine having a crankshaft and a fuel injection system with a fuel rail having at least one electrically operated fuel injector for injecting fuel into the engine, a fuel tank for holding liquid fuel, fuel supply means for supplying liquid fuel from the tank to the fuel rail to create pressurized fuel in the fuel rail for the at least one fuel injector, a pressure transducer for sensing the pressure of the pressurized fuel in the fuel rail and generating a pressurized fuel control signal in response thereto, a system for maintaining fuel pressure control comprising:
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a pump that is mechanically coupled in driven relation to the engine crankshaft; an electric control responsive to various electric signals including said pressurized fuel control signal for generating a pump control signal for controlling the operation of said pump as a function of said various electric signals for maintaining a desired fuel pressure in the fuel rail irrespective of variations in engine speed and torque as the engine operates; and an electrically-controlled clutch for connecting said pump to the engine crankshaft, said clutch being controlled in accordance with said pump control signal for maintaining said desired fuel pressure in the fuel rail by the extent to which said pump control signal allows power to be transmitted from the engine crankshaft through said clutch to said pump. - View Dependent Claims (3, 4, 5, 6, 7, 8)
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2. In an automotive vehicle engine having a crankshaft and a fuel injection system with a fuel rail having at least one electrically operated fuel injector for injecting fuel into the engine, a fuel tank for holding liquid fuel, fuel supply means for supplying liquid fuel from the tank to the fuel rail to create pressurized fuel in the fuel rail for the at least one fuel injector, a pressure transducer for sensing the pressure of the pressurized fuel in the fuel rail and generating a pressurized fuel control signal in response thereto, a system for maintaining fuel pressure control in a returnless fuel system comprising:
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a pump that is mechanically coupled in driven relation to the engine crankshaft; an electric control responsive to various electric signals including said pressurized fuel control signal for generating a pump control signal for controlling the operation of said pump as a function of said various electric signals for maintaining a desired fuel pressure in the fuel rail irrespective of variations in engine speed and torque as the engine operates without returning fuel from the fuel rail to the fuel tank; and an electrically-controlled clutch for connecting said pump to the engine crankshaft, said clutch being controlled in accordance with said pump control signal for maintaining said desired fuel pressure in the fuel rail by the extent to which said pump control signal allows power to be transmitted from the engine crankshaft through said clutch to said pump. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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Specification