Claims
- 1. Apparatus for controlling operation of an internal combustion engine which includes an intake manifold and which is selectively operable using gaseous fuel or liquid fuel, said apparatus comprising a gaseous fuel supply line extending between the engine and a source of gaseous fuel, a liquid fuel supply line extending between the engine and a source of liquid fuel, and means for controlling supply to the engine of the gaseous fuel and the liquid fuel, said control means including an operator controlled fuel selector switch comprising a first switch element connected to a source of electrical current and movable between a gaseous fuel position and a liquid fuel position, said control means being operable following prior engine operation with gaseous fuel and in response to movement of said fuel selector switch from said gaseous fuel position to said liquid fuel position for permitting liquid fuel flow through said liquid fuel supply line, for permitting continued gaseous fuel flow through said gaseous fuel supply line until initiation of liquid fuel combustion, and thereafter preventing further gaseous fuel flow through said gaseous fuel supply line until repositioning of said fuel selector switch to said gaseous fuel position, said control means also being operable following prior engine operation with liquid fuel and in response to movement of said fuel selector switch from said liquid fuel position to said gaseous fuel position for preventing further liquid fuel flow through said liquid fuel supply line, for preventing gaseous fuel flow through said gaseous fuel supply line until termination of liquid fuel combustion, and for thereafter permitting gaseous fuel flow through said gaseous fuel supply line until repositioning of said fuel selector switch to said liquid fuel position.
- 2. Apparatus in accordance with claim 1 wherein said control means also includes vacuum operated means responsive to engine vacuum conditions for controlling gaseous fuel flow through said gaseous fuel supply line.
- 3. Apparatus in accordance with claim 1 wherein said control means further includes a solenoid switch operable, when energized, to open said gaseous fuel supply line, and a vacuum-controlled switch electrically connected to said solenoid switch to effect energization thereof in response to a vacuum condition above a pre-determined level.
- 4. Apparatus in accordance with claim 1 wherein said control means further includes an electronic circuit coupled to said gaseous fuel supply line for opening and closing thereof, and a vacuum switch which is normally closed in the absence of a vacuum above a predetermined level, said vacuum switch being connected in series with said electronic circuit and said fuel selector switch.
- 5. Apparatus for controlling operation of an internal combustion engine which is selectively operable using gaseous fuel or liquid fuel, said apparatus comprising means for supplying a gaseous fuel to the engine, means for supplying a liquid fuel to the engine, and control means adapted to be connected to a source of vacuum which is responsive to engine operation and which varies relative to a predetermined level, said control means including a fuel selector switch comprising a first switch element connected to a source of current and movable between a gaseous fuel position and a liquid fuel position, an electrically operated, normally closed gaseous fuel control valve which is located in said gaseous fuel supply means, which is operable between open and closed positions, and which is opened in response to electrical energization thereof, and an electrically operated, normally closed liquid fuel control valve which is located in said liquid fuel supply means, which is operable between open and closed positions, and which is opened in response to electrical energization thereof, said control means being operable, when said selector switch is in said liquid fuel position, to energize said liquid fuel control valve, thereby opening said liquid fuel control valve, said control means also being operable, when said selector switch is in said liquid fuel position and in response to the presence of an amount of vacuum above said predetermined level to energize said gaseous fuel control valve, said control means also being operable, when said selector switch is in said liquid fuel position and in response to the presence of an amount of vacuum below said predetermined level, to deenergize said gaseous fuel control valve, and thereby close said gaseous fuel control valve, and thereafter to retain said gaseous fuel control valve deenergized regardless of vacuum variation, said control means also being operable, when said selector switch is in said gaseous fuel position, to deenergize said liquid fuel control valve, thereby closing said liquid fuel control valve, said control means also being operable, when said selector switch is in said gaseous fuel position and in response to an amount of vacuum above said predetermined level, to deenergize said gaseous fuel control valve, thereby closing said gaseous fuel control valve, and said control means also being operable, when said selector switch is in said gaseous fuel position and in response to an amount of vacuum below said predetermined level, to energize said gaseous fuel control valve and thereby open said gaseous fuel control valve, and thereafter to retain energization of said gaseous fuel control valve regardless of vacuum variation.
- 6. Apparatus in accordance with claim 5 wherein said apparatus further includes electrically operated spark advance means electrically connected to said control means and operable in response to energization thereof to advance the sparking time, and electrically operated intake air heating means electrically connected to said control means and operable in response to energization to prevent heating of the incoming air, and wherein said control means is inoperable, when said selector switch is in said liquid fuel position, to energize said spark advance means and said air intake means, and wherein said control means also being operable, when said selector switch is in said gaseous fuel position and in response to an amount of vacuum above said predetermined level, to deenergize said spark advance means and said inlet air heating means, and said control means also being operable, when said selector switch is in said gaseous fuel position and in response to an amount of vacuum below said predetermined level, to energize said spark advance means and said inlet air heating means, and thereafter to retain energization of said spark advance means and said intake air heating means regardless of vacuum variation.
- 7. Apparatus in accordance with claim 6 wherein said selector switch comprises a gaseous fuel terminal, a liquid fuel terminal, and a primary switch member connected to a source of direct current and movable between a first position energizing said gaseous fuel terminal and a second position energizing said liquid fuel terminal, wherein said control means further includes first switch means including a first terminal connected to said gaseous fuel control valve, to said spark advance means, and to said intake air heating means, a first switch member electrically connected to said gaseous fuel terminal and movable relative to a position energizing said first terminal, and thereby energizing said gaseous fuel control valve, said spark advance means, and said intake air heating means, said first switch member being biased away from said first terminal, and means for holding said first switch member in said position energizing said first terminal in response to energizing of said first terminal, wherein said control means further includes second switch means including a terminal connected to said gaseous fuel control valve, a holding terminal, a second switch member electrically connected to said liquid fuel terminal and movable between a first position engaging said terminal connected to said gaseous fuel control valve for energizing thereof, and a second position engaging said holding terminal, said second switch member being biases to said first position, and means connected to said holding terminal for holding said second switch member in said second position when said holding terminal is energized by said second switch member, wherein said control means further includes vacuum switch means connected to a source of direct current and to said first and second switch means and operable between an open position in response to the presence of an amount of vacuum above said predetermined level and a second position which is normally closed in the absence of the presence of an amount of vacuum above said predetermined level and which is operable to connect said first switch member to said holding terminal, and wherein said control means further includes a diode for preventing energization of said spark advance means and said intake air heating means when said primary switch member is in said liquid fuel position.
- 8. Apparatus in accordance with claim 7 wherein said engine includes a fuel inlet manifold and said vacuum switch communicates with said fuel inlet manifold and is subject to the pressure variation in said fuel inlet manifold.
- 9. Apparatus in accordance with claim 5 wherein said control means includes a solenoid switch operable, when energized, to open said gaseous fuel control valve, and a vacuum-controlled switch electrically connected to said solenoid switch to effect energization thereof in response to a vacuum condition above a pre-determined level.
- 10. Apparatus in accordance with claim 5 wherein said fuel selector switch further comprises a second switch member connected to a source of current and movable in unison with said first switch member between a gaseous fuel position and a liquid fuel position.
- 11. Apparatus in accordance with claim 10 wherein said control means further includes a secondary switch comprising a solenoid coil electrically connected to one of said first and second switch members when said fuel selector switch is in said gaseous fuel position, and a third switch operated by said solenoid coil, electrically connected to a source of direct current, and operable in response to energization of said solenoid to energize said gaseous fuel control valve.
- 12. Apparatus in accordance with claim 11 wherein said control means further includes a vacuum switch which is normally closed in the absence of a vacuum above a predetermined level and which is connected to said solenoid coil for energization thereof when said fuel selector switch is in the gaseous fuel position and when said vacuum switch is closed.
- 13. Apparatus in accordance with claim 12 wherein said control means includes means operable after initial energizing of said solenoid coil for maintaining said solenoid coil energized until movement of said fuel selector switch to said liquid fuel position and regardless of the vacuum condition at said vacuum switch.
- 14. Apparatus in accordance with claim 5 wherein said control means further includes a secondary switch comprising a solenoid coil and a second switch member operated by said solenoid coil and electrically connectable to said first switch member and operable to energize said gaseous fuel control valve.
- 15. Apparatus in accordance with claim 14 wherein said control means further includes a vacuum switch which is connected to a source of current, which is normally closed in the absence of a vacuum above a predetermined level, and which is connected to said solenoid cil for energization thereof when said vacuum switch is closed so as to energize said gaseous fuel control valve.
- 16. Apparatus in accordance with claim 15 wherein said control means includes means operable after initial energizing of said solenoid coil for maintaining said solenoid coil energized until movement of said fuel selector switch to said liquid fuel position and regardless of the vacuum condition at said vacuum switch.
- 17. A control in accordance with claim 5 wherein said control means further includes an electronic circuit coupled to said gaseous fuel control valve for opening and closing thereof, and a vacuum switch which is normally closed in the absence of a vacuum above a predetermined level, said vacuum switch being connected in series with said electronic circuit and said fuel selector switch.
- 18. Apparatus in accordance with claim 17 wherein said electronic circuit further includes means operable, in response to initial energizing thereof incident to positioning of said fuel selector switch in the gaseous fuel position and when said vacuum switch is closed, for thereafter maintaining said gaseous fuel control valve open until movement of said fuel selector switch to said liquid fuel position and regardless of the vacuum condition at said vacuum switch.
- 19. A control in accordance with claim 17 wherein said fuel selector switch includes a gaseous fuel terminal, a liquid fuel terminal and a switch member engaged with said gaseous fuel terminal when said fuel selector switch is in said gaseous fuel position and engaged with said liquid fuel terminal when said fuel selector switch is in said liquid fuel position.
- 20. Apparatus in accordance with claim 19 wherein said electronic circuit further includes first and second transistors in latching connecting, said first transistor including a base electrically connected to said gaseous fuel terminal of said fuel selector switch and said second transistor including a base electrically connected to said liquid fuel terminal of said fuel selector switch.
- 21. Apparatus for controlling operation of an internal combustion engine which is selectively operable using gaseous fuel or liquid fuel, said apparatus comprising means for supplying a gaseous fuel to the engine, means for supplying a liquid fuel to the engine, and control means including a vacuum operated switch adapted to be connected to a source of vacuum which is responsive to engine operation and which varies relative to a predetermined level, said switch being biased so that, in the absence of a vacuum condition above a pre-determined level, said switch is closed, said control means also including a fuel selector switch movable between a gaseous fuel position and a liquid fuel position, an electrically operated, normally closed gaseous fuel control valve which is located in said gaseous fuel supply means, which is operable between open and closed positions, and which is opened in response to electrical energization thereof, and an electrically operated, normally closed liquid fuel control valve which is located in said liquid fuel supply means, which is operable between open and closed positions, and which is opened in response to electrical energization thereof, said control means being operable, when said selector switch is in said liquid fuel position, to energize said liquid fuel control valve, thereby opening said liquid fuel control valve, said control means also being operable, when said selector switch is in said liquid fuel position and in response to the presence of an amount of vacuum above said predetermined level to energize said gaseous fuel control valve, said control means also being operable, when said selector switch is in said liquid fuel position and in response to the presence of an amount of vacuum below said predetermined level, to deenergize said gaseous fuel control valve, and thereby close said gaseous fuel control valve, and thereafter to retain said gaseous fuel control valve deenergized regardless of vacuum variation, said control means also being operable, when said selector switch is in said gaseous fuel position, to deenergize said liquid fuel control valve, thereby closing said liquid fuel control valve, said control means also being operable, when said selector switch is in said gaseous fuel position and in response to an amount of vacuum above said predetermined level, to deenergize said gaseous fuel control valve, thereby closing said gaseous fuel control valve, and said control means also being operable, when said selector switch is in said gaseous fuel position and in response to an amount of vacuum below said predetermined level, to energize said gaseous fuel control valve and thereby open said gaseous fuel control valve, and thereafter to retain energization of said gaseous fuel control valve regardless of vacuum variation.
- 22. A control in accordance with claim 21 wherein said engine includes an intake manifold, wherein said control means includes a conduit communicating between said engine intake manifold and said secondary switch, said conduit including a branch vent line communicable with the atmosphere, a valve member movable between a first position closing said branch vent line and a second position permitting communication of said branch vent line with the atmosphere, means biasing said valve member to said first position, and means for displacing said valve member against the action of said biasing means to said second position.
- 23. Apparatus in accordance with claim 22 wherein said fuel selector switch is connected to a source of current, and wherein said means for displacing said valve member to the second position comprises a solenoid electrically energized through said fuel selector switch.
- 24. Apparatus in accordance with claim 21 wherein said control means includes a solenoid switch operable, when energized, to open said gaseous fuel control valve and electrically connected to said vacuum switch to effect energization of said solenoid switch in response to a vacuum condition above a pre-determined level at said vacuum switch.
- 25. Apparatus in accordance with claim 21 wherein said control means further includes an electronic circuit which is coupled to said gaseous fuel control valve for opening and closing thereof, and which is electrically connected in series with said vacuum switch and said fuel selector switch.
- 26. Engine control apparatus including an internal combustion engine which includes an intake manifold which is selectively operable using gaseous fuel, means for supplying a gaseous fuel to said engine, means for supplying a liquid fuel to said engine, and control means including a vacuum operated switch adapted to be connected to a source of vacuum which is responsive to engine operation and which varies relative to a predetermined level, said switch being biased so that, in the absence of a vacuum condition alone the predetermined level, said switch is closed, a conduit communicating between said engine manifold and said vacuum switch, said control means also including a fuel selector switch movable between a gaseous fuel position and a liquid fuel position, an electrically operated, normally closed gaseous fuel control valve which is located in said gaseous fuel supply means, which is operable between open and closed positions, and which is opened in response to electrical energization thereof, and an electrically operated, normally closed liquid fuel control valve which is located in said liquid fuel supply means, which is operable between open and closed positions, and which is opened in response to electrical energization thereof, said control means being operable, when said selector switch is in said liquid fuel position, to energize said liquid fuel control valve, thereby opening said liquid fuel control valve, said control means also being operable, when said selector switch is in said liquid fuel position and in response to the presence of an amount of vacuum above said predetermined level, to energize said gaseous fuel control valve, said control means also being operable, when said selector switch is in said liquid fuel position and in response to the presence of an amount of vacuum below said predetermined level, to deenergize said gaseous fuel control valve, and thereby close said gaseous fuel control valve, and thereafter to retain said gaseous fuel control valve deenergized regardless of vacuum variation, said control means also being operable, when said selector switch is in said gaseous fuel position, to deenergize said liquid fuel control valve, thereby closing said liquid fuel control valve, said control means also being operable, when said selector switch is in said gaseous fuel position and in response to an amount of vacuum above said predetermined level, to deenergize said gaseous fuel control valve, thereby closing said gaseous fuel control valve, and said control means also being operable, when said selector switch is in said gaseous fuel position and in response to an amount of vacuum below said predetermined level, to energize said gaseous fuel valve and thereby open said gaseous fuel control valve, and thereafter to retain energization of said gaseous fuel control valve regardless of vacuum variation.
- 27. Apparatus in accordance with claim 26 wherein said apparatus further includes electrically operated spark advance means electrically connected to said control means and operable in response to energization thereof to advance the sparking time, and electrically operated intake air heating means electrically connected to said control means and operable in response to energization to prevent heating of the incoming air, and wherein said second switch comprises first and second switch members movable in unison between a normally engaged position and a second position, and wherein said first switch member is electrically connected to said gaseous fuel control valve for energization thereof when said switch members are in said second position, and wherein said second switch member is electrically connected to said spark advance means and to said intake air heating means for energization thereof when said switch members are in said normally engaged position.
- 28. Apparatus in accordance with claim 27 wherein said secondary switch includes a solenoid coil operable to move said first and second switch members to said second position in response to energization thereof.
- 29. Apparatus in accordance with claim 28 wherein said engine includes an intake manifold, and wherein said secondary switch is vacuum operated and is operable to move said first and second switch members to said second position in response to the presence at said secondary switch of a vacuum condition above a predetermined level, and further including a conduit communicating between said engine manifold and said vacuum switch.
- 30. Apparatus in accordance with claim 26 wherein said control means includes a solenoid switch operable, when energized, to open said gaseous fuel control valve and electrically connected to said vacuum switch to effect energization of said solenoid switch in response to a vacuum condition above a pre-determined level at said vacuum switch.
- 31. Apparatus in accordance with claim 26 wherein said control means further includes an electronic circuit which is coupled to said gaseous fuel control valve for opening and closing thereof, and which is electrically connected in series with said vacuum switch and said fuel selector switch.
- 32. Apparatus for controlling operation of an internal combustion engine which is selectively operable using gaseous fuel or liquid fuel, said apparatus comprising a gaseous fuel supply line extending between the engine and a source of gaseous fuel, a liquid fuel supply line extending between the engine and a source of liquid fuel, and means for controlling supply to the engine of the gaseous fuel and the liquid fuel, said control means including an operator controlled fuel selector switch movable between a gaseous fuel position and a liquid fuel position, and a vacuum operated switch which is biased so that, in the absence of a vacuum condition above a pre-determined level, said vacuum switch is closed, said control means being operable, following prior engine operation with gaseous fuel and in response to movement of said fuel selector switch from said gaseous fuel position to said liquid fuel position, for permitting liquid fuel flow through said liquid fuel supply line, for permitting continued gaseous fuel flow through said gaseous fuel supply line until initiation of liquid fuel combustion, and thereafter preventing further gaseous fuel flow through said gaseous fuel supply line until repositioning of said fuel selector switch to said gaseous fuel position, said control means also being operable following prior engine operation with liquid fuel and in response to movement of said fuel selector switch from said liquid fuel position to said gaseous fuel position for preventing further liquid fuel flow through said liquid fuel supply line, for preventing gaseous fuel flow through said gaseous fuel supply line until termination of liquid fuel combustion, and for thereafter permitting gaseous fuel flow through said gaseous fuel supply line until repositioning of said fuel selector switch to said liquid fuel position.
- 33. Apparatus in accordance with claim 32 wherein said control means further includes a solenoid switch which is operable, when energized, to open said gaseous fuel control valve and which is electrically connected to said vacuum switch to effect energization of said solenoid switch in response to a vacuum condition above a pre-determined level at said vacuum switch.
- 34. Apparatus in accordance with claim 32 wherein said control means further includes an electronic circuit which is coupled to said gaseous fuel supply line for opening and closing thereof and which is electrically connected in series with said vacuum switch and said fuel selector switch.
- 35. An engine control apparatus including an internal combustion engine which includes an intake manifold and which is selectively operable using gaseous fuel or liquid fuel, a gaseous fuel supply line extending between said engine and a source of gaseous fuel, a liqiud fuel supply line extending between said engine and a source of liquid fuel, and means for controlling supply to said engine of the gaseous fuel and the liquid fuel, said control means including an operator controlled fuel selector switch movable between a gaseous fuel position and a liquid fuel position, a vacuum operated switch which is biased so that, in the absence of a vacuum condition above a pre-determined level, said vacuum switch is closed, and a conduit communicating between said engine manifold and said vacuum switch, said control means being operable, following prior engine operation with gaseous fuel and in response to movement of said fuel selector switch from said gaseous fuel position to said liquid fuel position, for permitting liquid fuel flow through said liquid fuel supply line, for permitting continued gaseous fuel flow through said gaseous fuel supply line until initiation of liquid fuel combustion, and thereafter preventing further gaseous fuel flow through said gaseous fuel supply line until repositioning of said fuel selector switch to said gaseous fuel position, said control means also being operable, following prior engine operation with liquid fuel and in response to movement of said fuel selector switch from said liquid fuel position to said gaseous fuel position, for preventing further liquid fuel flow through said liquid fuel supply line, for preventing gaseous fuel flow through said gaseous fuel supply line until termination of liquid fuel combustion, and for thereafter permitting gaseous fuel flow through said gaseous fuel supply line until repositioning of said fuel selector switch to said liquid fuel position.
- 36. Apparatus in accordance with claim 35 wherein said control means further includes a solenoid switch which is operable, when energized, to open said gaseous fuel supply line and which is electrically connected to said vacuum switch to effect energization of said solenoid switch in response to a vacuum condition above a pre-determined level at said vacuum switch.
- 37. A control in accordance with claim 35 wherein said control means further includes an electronic circuit which is coupled to said gaseous fuel supply line for opening and closing thereof and which is electrically connected in series with said vacuum switch and said fuel selector switch.
RELATED INVENTION
This application is a continuation-in-part of my earlier application Ser. No. 314,225 filed Oct. 23, 1981, now U.S. Pat. No. 4,393,848.
US Referenced Citations (6)
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
314225 |
Oct 1981 |
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