초록 ▼

A fuel injection system operates under a substantially constant pump speed and creates multi-pressure levels by diverting the fuel flow. Fuel pressure can be switched from one steady pressure level to another level on-demand instantly. This superimposes and overlaps typical fuel injection events in

A fuel injection system operates under a substantially constant pump speed and creates multi-pressure levels by diverting the fuel flow. Fuel pressure can be switched from one steady pressure level to another level on-demand instantly. This superimposes and overlaps typical fuel injection events in the linear operating ranges under different pressure levels, significantly increasing the fuel injection dynamic range. Lower fuel injection when idle or during city driving reduces fuel consumption per mile traveled and reduces exhaust emission that causes smog in metropolitan areas. The system delivers additional power to the engine instantly at peak load on-demand, reduces idle speed with the engine running smoothly, does not change fuel tank temperature, and may enhance the life of the fuel pump.

대표청구항 ▼

The invention claimed is: 1. A multi-pressure fuel injection system for use with an engine, comprising; a fuel supply for the system; a fuel pump connected to the fuel supply and adapted to be operated at a predetermined speed; at least one fuel injector, a main fuel line, providing fluid connectio

The invention claimed is: 1. A multi-pressure fuel injection system for use with an engine, comprising; a fuel supply for the system; a fuel pump connected to the fuel supply and adapted to be operated at a predetermined speed; at least one fuel injector, a main fuel line, providing fluid connection from the outlet of the fuel pump to the at least one fuel injector; a fuel by-pass line with flow constraint having one end connected to some location on the main fuel line including the outlet of the fuel pump avoiding fuel rail and fuel injector, and the other end connected to some location in the fuel supply, including the inlet of the fuel pump, to provide fuel flow back to the fuel supply when the system is operating; and a fuel by-pass control in the fuel by-pass line, capable of opening and closing almost instantaneously, changing the pressure of the system between two designed pressure states, including a higher pressure state and a lower pressure state thereby essentially instantaneously changing the pressure of the fluid in the main fuel line between the two pressure states and the rate of fuel delivery at the at least one fuel injector. 2. A multi-pressure fuel injection system for use with an engine, comprising: a fuel supply for the system; a fuel pump connected to the fuel supply and adapted to be operated at a predetermined substantially constant speed; at least one fuel injector connecting to fuel rail, a main fuel line, providing fluid connection from the outlet of the fuel pump to the fuel rail and the at least one fuel injector; a fuel-return path having one end communicating with the main fuel line including the outlet of the fuel pump and avoiding fuel rail and fuel injectors, and the other end communicating with the fuel supply to the fuel pump inlet, and means for controlling additional flow through the fuel-return path to create a fuel recirculating loop to divert sufficient amounts of fuel during most of the operating conditions of the engine to substantially stabilize the pressures on the fuel pump to render the fuel system substantially self-regulating and to minimize the need of a hot fuel return; and a fuel by-pass line with flow constraint having one end connected to some location on the main fuel line including the outlet of the fuel pump and avoiding fuel rail and the at least one fuel injector, and the other end connected to some location in the fuel supply, including the inlet of the fuel pump, to provide fuel flow back to the fuel supply when the system is operating; and a fuel by-pass control in the fuel by-pass line, capable of opening and closing almost instantaneously, changing the pressure of the system between the two designated pressure states, including a higher pressure state PH and a lower pressure state PL thereby essentially instantaneously changing the pressure of the fluid in the main fuel line between the two pressure states and the rate of fuel delivery at the at least one fuel injector. 3. The system of claim 2, further comprising a fuel pump which maintains substantially constant speed irrespective of which of the pressure states the system is in and the by-pass control being effective so that the change of pressure is effective immediately. 4. The system of claim 2, further comprising a computer programmed to actuate the fuel injector to deliver pulses of fuel, the computer receiving signals indicating operating conditions of the engine in order to select between the pressure states and varying the pulse width to control the sizes of the injected fuel pulses over a dynamic range at the selected pressure state, the dynamic range being widened by switching between the pressure states, the computer delivering the pulses under the high pressure state under some operating conditions and under the lower pressure state under other operating conditions. 5. The system of claim 4, wherein the operating conditions are sensed from signals, including but not limited to engine temperature, speed, torque, fuel pressure and air pressure, pedal position sensing, operators intention, end adjustments are made as needed by a computer. 6. The system of claim 4, wherein the computer includes programming to signal the fuel bypass control to open and create the low pressure state in response to signals from engine management control that the engine is sufficiently warm and the amount of fuel per pulse being demanded is less than the maximum pulse amount available under the low pressure state. 7. The system of claim 4, wherein the fuel by-pass is adapted for the two pressure states to have overlapping fuel pressure operating ranges, the two ranges creating the widened dynamic range while the fuel pump runs at a substantially constant speed. 8. The system of claim 2, further comprising means for constraining the fuel flow, wherein said means comprises one of the following: an orifice plate with a hole of predetermined diameter, a needle-valve-like device, or a device compressing the fuel by-pass end the fuel-return line to create various fuel-return-flow and fuel-by-pass flow constraint. 9. A fuel injection system comprising: a fuel supply, at least one fuel injector, a fuel pump connected to the fuel supply and driven at a substantially constant speed; a fuel supply line from the outlet of the fuel pump to the at least one fuel injector. a fuel return path with flow constraint from the main fuel line, including the outlet of fuel pump and avoiding fuel rail, to fuel tank including the inlet of fuel pump; at least one fuel by-pass line, avoiding fuel rail and fuel injectors, with flow constraint connected between some location in the main fuel supply line, including the outlet of the fuel pump to some location in the fuel supply, including the inlet of the fuel pump, and a fuel by-pass control including programming to separately open and close each fuel bypass line essentially, instantaneously, the opening or closing of each by-pass control instantaneously changing the pressure of the system between a higher pressure state and a lower pressure state. 10. The system of claim 9, wherein the computer controls the opening or closing of each fuel-return line to create multiple pressure states at preset pressure levels. 11. The system of claim 9, wherein all fuel by-pass lines for fuel-return and fuel by-pass include a flow-constraint structure. 12. The system of claim 9, wherein the fuel by-pass control comprises an electromechanical valve and means for actuating the valve in response to fuel demand. 13. The system of claim 9, wherein a computer is provided to actuate fuel by-pass controls and includes programming to open and close the selected by-pass lines in response to varying fuel demands. 14. The system of claim 13, wherein there is a normally closed fuel by-pass line and the fuel by pass control includes programming to open the control in that normally closed fuel by-pass line during idling to create a lower pressure state, and the computer selects a corresponding minimum fuel pulse according to the lower pressure state to conserve fuel when gas pedal is released and during the idling. 15. The fuel injection system of claim 9 in which a computer is used for selectively opening or closing by-pass's controls in one or more selected bypass fuel lines in response to operating conditions of the engine to instantly create different selected fuel pressure states in the system for fuel demand. 16. The system of claim 9, wherein the fuel pump has another predetermined speed to further enhance fuel injection dynamic range. 17. A multi-pressure fuel injection system for use with an engine, comprising, a fuel supply for storing fuel for the system, a fuel pump adapted to be operated at predetermined speed, at least one fuel injector, a main fuel line providing fluid connection from the outlet of the fuel pump and to the at least one fuel injector, at least two fuel by-pass lines with flow constraint having one end connected to some location on the main fuel line avoiding the fuel rail and fuel injectors, and the other end connected to some location in the fuel supply, including the inlet or the fuel pump, a fuel by-pass control in each fuel by-pass line capable of opening and closing its line almost instantaneously, thereby essentially instantaneously changing the pressure of the fluid in the main fuel line between two pressure states and the rate of fuel delivery at the at least one fuel injector, a computer to open and close selectively each fuel by-pass control. 18. The system of claim 17, wherein the computer includes programming to open and close selected by-pass lines selectively to create at least three pressure levels. 19. The system of claim 17, comprising two fuel by-pass lines, one a normally closed fuel by-pass and the other normally open fuel-return line. 20. The system of claim 19, wherein the fuel-return line is normally open to allow fuel recirculation in the fuel system to stabilize pump operation and minimize the need of a hot fuel return. 21. The system of claim 20, wherein the computer includes programming to process signals corresponding to power demands of the user and to dose both fuel return lines to create additional, available maximum engine power. 22. The fuel injection system of claim 17 in which the computer receives control signals based on the amount of fuel being demanded in response to engine operating conditions, including operators input and the engine temperature, to generate signals to open or close the fuel by-pass control in each fuel by-pass line to allow selected pressure at the at least one fuel injector, and to adjust the fuel injection pulse width according to engine fuel demand. 23. The fuel injection system of claim 17 in which the computer also adjusts the injection pulse width of a plurality of fuel injectors used in a particular system. 24. A fuel injection system for delivering fuel from a fuel supply to fuel injectors of an engine, the system comprising: a fuel supply; a fuel pump driven at a substantially constant speed; at least one fuel injector; at least one fuel by-pass line avoiding fuel rail and fuel injectors, connecting the outlet of the fuel pump and the fuel supply; a fuel by-pass control in each fuel by-pass line for opening and closing substantially instantaneously in a selected by-pass line in response to operating conditions of the engine to create different fuel pressures in the system, a computer for determining the amount of fuel required per pulse for fuel injection, for determining whether the required amount of fuel is within the limit of one or more of the fuel pressures producible in the system, and for selecting the appropriate one of the fuel pressures in response to (a) operating condition of the engine, (b) the demand for engine power, or (c) manual control by the operator. 25. The system of claim 24, wherein the computer actuates the by-pass control in selected fuel by-pass lines during cold engine operations to create a first, higher pressure state, the computer receiving signals from engine management control that the engine is warm and the demanded fuel pulse is less than the maximum fuel pulse which the lower pressure slate can supply, opening the fuel by-pass path to create the lowest pressure state which is, higher than the minimum pressure needed to assure proper fuel spraying. 26. A method of improving city-driving fuel efficiency in a fuel injection engine comprising, pumping fuel from a fuel tank to a fuel rail and at least one fuel injector for the engine at a predetermined substantially constant speed, by-passing some fuel from main fuel line, including the outlet of the fuel pump, avoiding the fuel rail and fuel injector, back to the fuel tank by a normally closed connection with flow constraint, opening on-demand the normally closed connection to instantaneously vary the fluid pressure of the fuel from higher pressure state PH to the lower pressure state PL thereby instantaneously reducing fuel pressure and the amount of injected fuel at the at least one fuel injector every time the gas pedal is released for fuel saving in city driving. 27. The method of claim 26 in which the two pressure states include one PL near the lowest minimum pressure at which fuel can be effectively injected for fine fuel spraying and one PH near the nearest state to that desired to produce maximum power. 28. The method of claim 27 in which further control of fuel feed at each state can be accomplished by varying the pulse width of injection pulses at each injection nozzle to vary me amount of fuel injected at each pulse, wherein the minimum allowed pulse width at low pressure state is used when the gas pedal is released and for idling to save fuel in city driving, and the maximum pulse width at high pressure state is used to produce maximum power rated for me engine. 29. A method of providing exceptional high-performance and improving city driving fuel efficiency in a fuel injection engine comprising, pumping fuel from a fuel tank to at least one fuel injector for the engine at a substantially constant predetermined speed, by-passing some fuel from the fuel pump outlet back to the fuel tank by a normally closed connection with flow constraint avoiding the fuel injector, returning same fuel from the fuel pump outlet back to the fuel tank by another normally open connection with flow constraint avoiding the fuel rail and the fuel injector to form a fuel circulating loop stabilizing the fuel pump operation and minimizing the need of hot fuel return line, and opening and closing both or one of the connections with essentially no time lag to instantaneously vary the fluid pressure of the fuel among at least three pressure states and thereby instantaneously varying the amount of injected fuel pulses for a given pulse width at the at least one fuel injector for each pressure state. 30. The method of claim 29 in which the at least two lower pressure states among the three pressure states include one near the lowest minimum pressure required for fine fuel spraying and one near the nearest state to that desired to produce maximum power. 31. The method of claim 29 in which further control of fuel feed at each state can be accomplished by varying the injection pulse width at each injection nozzle the amount of fuel injected at each pulse, where the minimum allowed pulse width at low pressure state is used for city driving when gas pedal is released and for idling and the maximum pulse width at high pressure state is used to produce maximum power rated for the engine. 32. The method of claim 29 in which after repeated verifications of operator's urgent needs for maximum power the Vgas=(Vgas)max for N times to avoid faulty electronic signal and the engine is not overheating, activating signals to close both fuel-return and fuel by-pass lines creating the 3rd high pressure state, opening the throttle valve and other air accessories for maximum air in-take, and delivering maximum fuel injection for extraordinary power exceeding the maximum rating of the engine for a short duration. 33. A method of modifying existing vehicles with fuel injection engines to achieve better fuel efficiency in city-driving comprising, connecting at least one normally closed fuel by-pass line with flow constraint and a controller from the main fuel line avoiding fuel rail back to the fuel supply or the intake side of the fuel pump, and opening the normally closed fuel by-pass line with fuel constraint on demand when the engine is warm to reduce the fuel pressure, thus saving fuel every time when gas pedal is released and during idling to achieve fuel efficiency in city-driving. 34. The method of claim 33, creating and storing in a controller memory a separate set of fuel injected per pulse versus pulse width values for the new low pressure state as the look up chart so that engine management controller can deliver proper amount of fuel when engine is operating at the new low pressure state to reduce idling speed and every time when gas pedal is released, thus achieving fuel efficiency in city-driving. 35. A fuel injection system comprising: a fuel supply, at least one fuel injector, a fuel pump connected to the fuel supply and driven at a substantially constant speed, a main fuel line from the outlet of the fuel pump to the at least one fuel injector, at least two fuel bypass lines with flow constraint connected from some location in the main fuel line including the fuel pump outlet avoiding fuel rail and fuel injectors, to some location in the fuel supply, including the fuel pump inlet, and a fuel by-pass control in at least one fuel bypass line which can selectively open and close the by-pass line to instantaneously change system fuel pressure states. 36. A fuel injection system providing exceptional high performance and still achieving fuel saving in city driving comprising: a fuel supply, at least one fuel injector, a fuel pump having an outlet and an inlet connected to the fuel supply and driven at a substantially constant speed, a main fuel line from the outlet of the fuel pump to the at least one fuel injector, two fuel bypass lines with flow constraint connected from the main fuel line, including the fuel pump outlet but excluding fuel injector, to the fuel supply including the inlet of the fuel pump, or both, and a fuel by-pass control in each fuel bypass line which can be opened or closed essentially instantaneously, the control in one bypass line being normally open so that its line normally allows fuel recirculation in the system to stabilize the fuel pump operation and to minimize the need of hot fuel return line, and the fuel by-pass control in the other fuel bypass line being normally closed so that its line can be opened to reduce fuel pressure as needed for fuel saving in city driving. 37. The fuel injection system of claim 36 in which a computer is provided to determine when conditions are right for either of the two conditions: (a) of one normally closed controller being open for fuel saving in city driving, or (b) both controls being closed to provide for greater acceleration for limited periods when the engine temperature will permit it and other conditions are appropriate, at which time, upon operation demand, both fuel line controls are closed to greatly increase the pressure above the higher of the two pressure states. 38. A fuel injection system for delivering pressurized fuel from a fuel supply to fuel injectors of an engine which uses a fuel recirculation loop to minimize or eliminate the need of a hot fuel return line and a low pressure regulator comprising: a fuel supply, a fuel rail in fluid communication with at least one fuel injector, a fuel pump having an outlet and an inlet, the inlet being connected to the fuel supply and driven at a substantially constant speed, a main fuel supply line connected from the outlet of the fuel pump to the fuel rail in fluid communication with the at least one fuel injector, a fuel return path with flow constraint, connected from some location in the main fuel supply line, including the outlet of the fuel pump, avoiding fuel rail to some location in the fuel supply including the inlet of the fuel pump, allowing fuel recirculation to stabilize the pump operation, and creating stable fuel pressure. 39. The fuel injection system of claim 38 comprising at least one additional fuel by-pass line connected between some location in the main fuel supply line, including the outlet of the fuel pump avoiding fuel rail to some location in the fuel supply, including the inlet of the fuel pump, and a fuel by-pass control to open and close each additional fuel by-pass line, the opening or closing of each fuel by-pass control instantaneously changing the pressure of the system between a higher pressure state and a lower pressure state. 40. A fuel injection system for delivering fuel from a fuel supply to fuel injectors of an engine which uses a fuel recirculation loop to minimize the need of a hot fuel return line and a low pressure regulator, comprising: a fuel supply, a fuel rail in fluid communication with at least one fuel injector, a fuel pump having an outlet and an inlet, the inlet being connected to the fuel supply and driven at a substantially constant speed, a main fuel supply line connected from the outlet of the fuel pump to the fuel rail in fluid communication with at least one fuel injector, a fuel return path with flow constraint, provided by an orifice of predetermined diameter in the return path connected from some location in the main fuel supply line, including the outlet of the fuel pump avoiding fuel rail, to some location in the fuel supply including the inlet of the fuel pump, allowing fuel recirculation to stabilize the pump operation creating stable fuel pressure. 41. A fuel injection system for delivering fuel from a fuel supply to fuel injectors of an engine, which uses a fuel recirculation loop to minimize the need of a hot fuel return line and a low pressure regulator, comprising: a fuel supply, a fuel rail in fluid communication with at least one fuel injector, a fuel pump having an outlet and an inlet, the inlet being connected to the fuel supply and driven at a predetermined substantially constant speed, a main fuel supply line connected from the outlet of the fuel pump to the fuel rail in fluid communication with the at least one fuel injector, a fuel return path with flow constraint provided by a needle valve in the return path, connected from some location in the main fuel supply line, including the outlet of the fuel pump, avoiding the fuel rail, to some location in the fuel supply including the inlet of the fuel pump, avoiding fuel recirculation to stabilize the pump operation creating stable fuel pressure. 42. A fuel injection system for delivering pressurized fuel from a fuel supply to fuel injectors of an engine which uses a fuel recirculation loop to minimize the need of a hot fuel return line and a low pressure regulator, comprising: a fuel supply, a fuel rail in fluid communication with at least one fuel injector, a fuel pump having an outlet and an inlet, the inlet being connected to the fuel supply and driven at a substantially constant speed, a main fuel supply line connected from the outlet of the fuel pump to the fuel rail in fluid communication with at least one fuel injector, a fuel return path with flow constraint, provided by a device compressing the fuel by-pass or the fuel-return path, connected from some location in the main fuel supply line, including the outlet of the fuel pump avoiding fuel rail, to some location in the fuel supply including the inlet of the fuel pump, allowing fuel recirculation to stabilize the pump operation creating stable fuel pressure. 43. A method of obtaining highest pressure instantaneously to deliver maximum fuel injection pulses for start-up of cold direct injection engine and for short burst of power for acceleration, comprising: closing all fuel by-pass lines, and closing all fuel return lines including closing all excess fuel return lines from pressure regulators if there is any. 44. A kit providing fuel saving and auto exhaust reduction in city driving for vehicles with a fuel injection system for internal combustion engines currently in production or earlier models of vehicles already in use, comprising, a by-pass fuel line with flow constraint including a normally closed electromagnetic valve, for connecting from the main fuel line back to fuel tank to provide a fuel pump by-pass path without changing normal fuel delivering flow, hardware connection, such as a T, allowing connection of the by-pass fuel line into main fuel line, including the outlet of fuel pump, avoiding fuel rail and fuel injector, hardware connection permitting the other end of the fuel by-pass line to be connected into a fuel return line, or directly into the fuel tank in a manner to prevent leakage of fuel vapor to the air, and means for opening the normally closed electromagnetic valve in the by-pass line when engine is warm and the vehicle is in the city driving mode to instantaneously reduce the fuel pressure to a predetermined level to save fuel every time the gas pedal is released including during idling. 45. The kit of claim 44 which include a conveniently positionable manually actuated switch in the control circuit of the electromagnetic valve that allows the operator in observing the engine temperature gauge to instantaneously open the normally closed fuel valve in the fuel by-pass line to choose the lower pressure state PL for fuel saving in city driving. 46. The kit of claim 44 which includes programs to be installed in memory supplementing the existing E.C.U. and Engine Management Control for operating the electromagnetic valve in the fuel by-pass line, comprising: additional look-up chart of fuel pulse versus pulse width curves under the lower pressure state PL and under the higher pressure state PH, end operating software program including the selection of a proper pressure state from the lower pressure state PL for city driving, or the higher pressure state PH for highway driving.