Carburetor kit for improved air-fuel mixture
First Claim
1. A carburetor kit for improving the emissions of internal-combustion engines having an exhaust manifold generating a positive-pressure gas stream and 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 connecting the float chamber of the carburetor and the exhaust manifold, 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 exhaust gases of the engine and for generating a signal corresponding to said oxygen content; and
(f) first 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.
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Abstract
Flow passage lines are used to connect the float chamber of a conventional carburetor both to the engine'"'"'s intake and exhaust manifold. The gas flow produced by the exhaust manifold provides a continuous source of positive pressure to the float chamber, while the engine'"'"'s suction and the corresponding vacuum in the intake manifold provide a continuous source of negative pressure. The flow rates in the positive pressure line and in the negative pressure line are regulated by means of two control solenoid valves. The pressure in the float chamber reflects the net impact of the positive and negative pressures transmitted trough the lines. The solenoid valves are responsive to a control signal generated by an electronic circuit as a function of deviations in the oxygen content of the exhaust gases from a desired set point. The ambient pressure in the float chamber is either increased or decreased as the oxygen sensor indicates that either a lean or a rich fuel mixture is being combusted in the engine. A third solenoid valve in series in the negative pressure line and an accumulator chamber are also used to provide fine control to the vacuum from the intake manifold. Finally, a bypass air bleed may be used to increase the air/fuel ratio at idle.
30 Citations
24 Claims
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1. A carburetor kit for improving the emissions of internal-combustion engines having an exhaust manifold generating a positive-pressure gas stream and 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:
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(a) first pneumatic passage means for connecting the float chamber of the carburetor and the exhaust manifold, 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 exhaust gases of the engine and for generating a signal corresponding to said oxygen content; and (f) first 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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A carburetor kit 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:
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(a) 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; (b) first valve means for controlling the flow rate through said pneumatic passage means; (c) second valve means connected in series with said first valve means for regulating said negative pressure differential available for application to the float chamber; (d) sensor means for measuring the oxygen content of exhaust gases of the engine and for generating a signal corresponding to said oxygen content; and (e) electronic control means for actuating said first and second valve means in response to the signal generated by said sensor means, such that a flow rate through said first and 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. - View Dependent Claims (20, 21, 22, 23)
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24. A carburetor kit 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:
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(a) 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; (b) first valve means for controlling the flow rate through said pneumatic passage means; (c) a bypass line connected in parallel to said venturi tube and comprising second valve means in said bypass line for regulating a flow of said air stream through the bypass line; (d) sensor means for measuring the oxygen content of exhaust gases of the engine and for generating a signal corresponding to said oxygen content; and (e) 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 increases and is progressively increased as the oxygen content in the exhaust gases decreases; 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.
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Specification