Claims
- 1. Apparatus for improving the emissions of internal-combustion engines having an engine fan generating a first air stream and a carburetor wherein an air-fuel mixture is produced by drawing fuel from a fuel float chamber into a second air stream flowing through a venturi tube as a result of a vacuum provided at an intake manifold, comprising:
- (a) first pneumatic passage means for connecting the float chamber of the carburetor and the first air stream, so that a positive pressure differential is available for application to the float chamber;
- (b) second pneumatic passage means for connecting the float chamber and the intake manifold, so that a negative pressure differential is available for application to the float chamber;
- (c) first valve means for controlling the flow rate through said first pneumatic passage means;
- (d) second valve means for controlling the flow rate through said second pneumatic passage means;
- (e) sensor means for measuring the oxygen content of the exhaust gases of the engine and for generating a signal corresponding to said oxygen content; and
- (f) electronic control means for actuating said first valve means in response to the signal generated by said sensor means, such that a flow rate through said first valve means is progressively reduced as the oxygen content in the exhaust gases decreases and is progressively increased as the oxygen content in the exhaust gases increases; and for actuating said second valve means in response to the signal generated by said sensor means, such that a flow rate through said second valve means is progressively reduced as the oxygen content in the exhaust gases increases and is progressively increased as the oxygen content in the exhaust gases decreases.
- 2. The apparatus of claim 1, wherein said first and second pneumatic passage means are connected to form a single passage downstream of said first and second valve means.
- 3. The apparatus of claim 2, wherein said first pneumatic passage means consists of a pressure line having a first open end facing the first air stream and a second end connected to the float chamber, and wherein said second pneumatic passage means consists of a vacuum line having a first end connected to the intake manifold and a second end connected to said pressure line.
- 4. The apparatus of claim 1, wherein each of said first and second valve means consists of a solenoid valve that is opened by cyclical pulses transmitted at variable frequency by said electronic control means.
- 5. The apparatus of claim 1, further comprising at least one calibration orifice in each of said first and second pneumatic passage means.
- 6. The apparatus of claim 3, wherein said first valve means consists of a solenoid valve having a normally-open first input port connected to said pressure line and having a normally-closed second input port connected to atmosphere and wherein said second valve means consists of a solenoid valve having a normally-closed first input port connected to said vacuum line and having a normally-open second input port connected to atmosphere; wherein said first and second input ports are opened and closed, respectively, by cyclical pulses transmitted at variable frequency by said electronic control means.
- 7. The apparatus of claim 6, further comprising at least one calibration orifice in each of said second input ports connected to atmosphere.
- 8. The apparatus of claim 1, further comprising means responsive to acceleration and deceleration conditions in the engine for sending a corresponding signal to said electronic control means, such that said first valve means is open to said first air stream during acceleration conditions and said second valve means is open to said vacuum line during deceleration conditions.
- 9. Apparatus for improving the emissions of internal-combustion engines having an engine fan generating a first air stream and a carburetor wherein an air-fuel mixture is produced by drawing fuel from a fuel float chamber into a second air stream flowing through a venturi tube as a result of a vacuum provided at an intake manifold, comprising:
- (a) first pneumatic passage means for connecting the float chamber of the carburetor and the first air stream, so that a positive pressure differential is available for application to the float chamber;
- (b) second pneumatic passage means for connecting the float chamber to a point upstream of a throttle in the venturi tube, so that a negative pressure differential is available for application to the float chamber when said throttle is at least partially open;
- (c) first valve means for controlling the flow rate through said first pneumatic passage means;
- (d) second valve means for controlling the flow rate through said second pneumatic passage means;
- (e) sensor means for measuring the oxygen content of the exhaust gases of the engine and for generating a signal corresponding to said oxygen content; and
- (f) electronic control means for actuating said first valve means in response to the signal generated by said sensor means, such that a flow rate through said first valve means is progressively reduced as the oxygen content in the exhaust gases decreases and is progressively increased as the oxygen content in the exhaust gases increases; and for actuating said second valve means in response to the signal generated by said sensor means, such that a flow rate through said second valve means is progressively reduced as the oxygen content in the exhaust gases increases and is progressively increased as the oxygen content in the exhaust gases decreases.
- 10. Apparatus for improving the emissions of internal-combustion engines having a carburetor wherein an air-fuel mixture is produced by drawing fuel from a fuel float chamber into an air stream flowing through a venturi tube as a result of a vacuum provided at an intake manifold, comprising:
- (a) first pneumatic passage means for venting the float chamber of the carburetor to atmosphere, so that an atmospheric pressure is available for application to the float chamber;
- (b) second pneumatic passage means for connecting the float chamber to the intake manifold, so that a negative pressure differential is available for application to the float chamber;
- (c) first valve means for controlling the flow rate through said first pneumatic passage means;
- (d) second valve means for controlling the flow rate through said second pneumatic passage means;
- (e) sensor means for measuring the oxygen content of the exhaust gases of the engine and for generating a signal corresponding to said oxygen content; and
- (f) electronic control means for actuating said first valve means in response to the signal generated by said sensor means, such that a flow rate through said first valve means is progressively reduced as the oxygen content in the exhaust gases decreases and is progressively increased as the oxygen content in the exhaust gases increases; and for actuating said second valve means in response to the signal generated by said sensor means, such that a flow rate through said second valve means is progressively reduced as the oxygen content in the exhaust gases increases and is progressively increased as the oxygen content in the exhaust gases decreases.
- 11. A method of improving the emissions of internal-combustion engines having an engine fan generating a first air stream and a carburetor wherein an air-fuel mixture is produced by drawing fuel from a fuel float chamber into a second air stream flowing through a venturi tube as a result of a vacuum provided at an intake manifold, comprising the following steps:
- (a) connecting the float chamber of the carburetor and the first air stream through first pneumatic passage means, so that a positive pressure differential is available for application to the float chamber;
- (b) connecting the float chamber and the intake manifold through second pneumatic passage means, so that a negative pressure differential is available for application to the float chamber;
- (c) providing first valve means for controlling the flow rate through said first pneumatic passage means;
- (d) providing second valve means for controlling the flow rate through said second pneumatic passage means;
- (e) providing sensor means for measuring the oxygen content of the exhaust gases of the engine and for generating a signal corresponding to said oxygen content; and
- (f) providing electronic control means for actuating said first valve means in response to the signal generated by said sensor means, such that a flow rate through said first valve means is progressively reduced as the oxygen content in the exhaust gases decreases and is progressively increased as the oxygen content in the exhaust gases increases; and for actuating said second valve means in response to the signal generated by said sensor means, such that a flow rate through said second valve means is progressively reduced as the oxygen content in the exhaust gases increases and is progressively increased as the oxygen content in the exhaust gases decreases.
- 12. The method of claim 11, further comprising the step of connecting said first and second pneumatic passage means to form a single passage downstream of said valve means.
- 13. The method of claim 12, wherein said step (a) is accomplished by providing a pressure line having two ends, by placing the first open end facing the first air stream and by connecting the second end to the float chamber; and wherein said step (b) is accomplished by providing a vacuum line having two ends, and by connecting the first end to the intake manifold and the second end to the pressure line.
- 14. The method of claim 11, wherein said steps (c) and (d) are each accomplished by providing a solenoid valve that is opened by cyclical pulses transmitted at variable frequency by the electronic control means.
- 15. The method of claim 11, further comprising the step of installing at least one calibration orifice in each of said first and second pneumatic passage means.
- 16. The method of claim 13, wherein said step (c) is accomplished by providing a solenoid valve having a normally-open first input port connected to said pressure line and having a normally-closed second input port connected to atmosphere and said step (d) is accomplished by providing a solenoid valve having a normally-closed first input port connected to said vacuum line and having a normally-open second input port connected to atmosphere; wherein said first and second input ports are opened and closed, respectively, by cyclical pulses transmitted at variable frequency by said electronic control means.
- 17. The method of claim 16, further comprising the step of providing at least one calibration orifice in each of said second input ports connected to atmosphere.
- 18. The method of claim 11, further comprising the step of providing means responsive to acceleration and deceleration conditions in the engine for sending a corresponding signal to the electronic control means, such that the first valve means is opened to said first air stream during acceleration conditions and said second valve means is opened to said vacuum line during deceleration conditions.
- 19. A method for improving the emissions of internal-combustion engines having an engine fan generating a first air stream and a carburetor wherein an air-fuel mixture is produced by drawing fuel from a fuel float chamber into a second air stream flowing through a venturi tube as a result of a vacuum provided at an intake manifold, comprising the following steps:
- (a) connecting the float chamber of the carburetor and the first air stream through first pneumatic passage means, so that a positive pressure differential is available for application to the float chamber;
- (b) connecting the float chamber to a point upstream of a throttle in the venturi tube through second pneumatic passage means, so that a negative pressure differential is available for application to the float chamber when said throttle is at least partially open;
- (c) providing first valve means for controlling the flow rate through said first pneumatic passage means;
- (d) providing second valve means for controlling the flow rate through said second pneumatic passage means;
- (e) providing sensor means for measuring the oxygen content of the exhaust gases of the engine and for generating a signal corresponding to said oxygen content; and
- (f) providing electronic control means for actuating said first valve means in response to the signal generated by said sensor means, such that a flow rate through said first valve means is progressively reduced as the oxygen content in the exhaust gases decreases and is progressively increased as the oxygen content in the exhaust gases increases; and for actuating said second valve means in response to the signal generated by said sensor means, such that a flow rate through said second valve means is progressively reduced as the oxygen content in the exhaust gases increases and is progressively increased as the oxygen content in the exhaust gases decreases.
- 20. A method for improving the emissions of internal-combustion engines having a carburetor wherein an air-fuel mixture is produced by drawing fuel from a fuel float chamber into an air stream flowing through a venturi tube as a result of a vacuum provided at an intake manifold, comprising the following steps:
- (a) providing first pneumatic passage means for venting the float chamber of the carburetor to atmosphere, so that an atmospheric pressure is available for application to the float chamber;
- (b) connecting the float chamber to the intake manifold through second pneumatic passage means, so that a negative pressure differential is available for application to the float chamber;
- (c) providing first valve means for controlling the flow rate through said first pneumatic passage means;
- (d) providing second valve means for controlling the flow rate through said second pneumatic passage means;
- (e) providing sensor means for measuring the oxygen content of the exhaust gases of the engine and for generating a signal corresponding to said oxygen content; and
- (f) providing electronic control means for actuating said first valve means in response to the signal generated by said sensor means, such that a flow rate through said first valve means is progressively reduced as the oxygen content in the exhaust gases decreases and is progressively increased as the oxygen content in the exhaust gases increases; and for actuating said second valve means in response to the signal generated by said sensor means, such that a flow rate through said second valve means is progressively reduced as the oxygen content in the exhaust gases increases and is progressively increased as the oxygen content in the exhaust gases decreases.
RELATED APPLICATIONS
This application is a continuation-in-part of U.S. application Ser. No. 08/016,047, filed Feb. 10, 1993, currently copending.
US Referenced Citations (8)
Continuation in Parts (1)
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Number |
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16047 |
Feb 1993 |
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