US3750401A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Exhaust gas after-burning system for automotive internal combustion engine
Assignee: Nissan Motor Co Ltd
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Filing: 1971-12-07
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Granted: 1973-08-07
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Expires: 1991-12-07
Abstract
Abstract An exhaust gas after-burning system for reducing vehiclular air pollution, which system includes a reactor for re-oxidizing the unburned components of engine exhaust gases, such as hydrocarbons and carbon monoxides. A fuel supply unit is incorporated in the system for supplying secondary fuel in controlled quantities to the reactor. The system also includes an air supply unit for suppying air in controlled quantities to the reactor. The quantities of the secondary fuel and air supplied to the reactor increase with engine loads, the air-fuel ratio of the mixture being kept low, for example, of the order of 20:1 to 50:1. The combustible mixture of the secondary fuel and air is ignited within the reactor by an ignition plug, so that the exhaust''s unburned gases are burned completely. The fuel supply unit includes a check valve having a pressure chamber and adapted to be opened to allow the fuel flow from the pressure chamber to the reactor therethrough when the pressure within the pressure chamber exceeds a predetermined value. A fuel pump is provided for delivering the secondary fuel from a fuel tank to the pressure chamber. In response to engine loads, a solenoid valve operates to control the return flow of the secondary fuel from the pressure chamber to the fuel tank to thereby vary the fuel pressure within the chamber, so that the quantity of secondary fuel supplied to the reactor is controlled.
Inventors
- 👤 S Nambu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 03:54
CPC Classifications
F; F01; F01N; F01N3/00; F01N3/08; F01N3/10; F01N3/24; F01N3/26; F01N3/38
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
270 words
An exhaust gas after-burning system for an automotive internal combustion engine having a throttle valve, an intake manifold and engine cylinders, comprising: a reactor for oxidizing exhaust gases, said reactor having an inner casing and an outer casing between which an outer chamber is defined, said inner casing having a plurality of openings formed therein providing communication between said outer chamber and an inner chamber defined within said inner casing; a main exhaust pipe connecting the engine cylinders to said outer chamber; means for supplying air in controlled quantities to said inner chamber, the quantity of the air supplied to said inner chamber being dependent upon engine loads; means for supplying fuel in controlled quantities to said inner chamber, said fuel supplying means comprising a fuel reservoir for storing the fuel to be supplied to said inner chamber, a fuel pump having its suction port connected to said fuel reservoir, means defining a pressure chamber and having its inlet connected to the fuel pump discharge and having an outlet, means for allowing the fuel flow from said pressure chamber to said inner chamber of said reactor when the fuel pressure within said pressure chamber exceeds a predetermined value, and means connected to the outlet of said pressure chamber for controlling the return flow of the fuel from said pressure chamber to said fuel reservoir in accordance with engine loads; and means for igniting a combustible mixture of the fuel and air supplied to said inner chamber, whereby the exhaust gases discharged into said inner chamber are burned completely at high temperatures due to the combustion of the fuel and air.
Claim 2
Dependent Claim
270 words
An exhaust gas after-burning system for an automotive internal combustion engine having a throttle valve, an intake manifold and engine cylinders, comprising: a reactor for oxidizing exhaust gases, said reactor having an inner casing and an outer casing between which an outer chamber is defined, said inner casing having a plurality of openings formed therein providing communication between said outer chamber and an inner chamber defined within said inner casing; a main exhaust pipe connecting the engine cylinders to said outer chamber; means for supplying air in controlled quantities to said inner chamber, the quantity of the air supplied to said inner chamber being dependent upon engine loads; means for supplying fuel in controlled quantities to said inner chamber, said fuel supplying means comprising a fuel reservoir for storing the fuel to be supplied to said inner chamber, a fuel pump having its suction port connected to said fuel reservoir, means defining a pressure chamber and having its inlet connected to the fuel pump discharge and having an outlet, means for allowing the fuel flow from said pressure chamber to said inner chamber of said reactor when the fuel pressure within said pressure chamber exceeds a predetermined value, and means connected to the outlet of said pressure chamber for controlling the return flow of the fuel from said pressure chamber to said fuel reservoir in accordance with engine loads; and means for igniting a combustible mixture of the fuel and air supplied to said inner chamber, whereby the exhaust gases discharged into said inner chamber are burned completely at high temperatures due to the combustion of the fuel and air.
Claim 3
Dependent Claim
85 words
An exhaust gas after-burning system according to claim 1, wherein said air supplying means comprises an air pump having its discharge coupled to the outer chamber of said reactor, and an air flow control valve connected to the suction port of said air pump for controlling the amount of air supplied to said air pump, said air flow control valve being operatively associated with the engine throttle valve in such a manner as to allow more air to flow therethrough when throttle valve opening increases.
Claim 4
Dependent Claim
36 words
An exhaust gas after-burning system according to claim 1, further comprising a nozzle for injecting air into said main exhaust pipe so as to facilitate the reoxidation of the unburned gases emitted from the engine cylinders.
Claim 5
Dependent Claim
39 words
An exhaust gas after-burning system according to claim 1, wherein said fuel supplying means further includes a filter provided between said fuel reservoir and said fuel pump inlet to prevent dirt in the fuel from entering said fuel pump.
Claim 6
Dependent Claim
87 words
An exhaust gas after-burning system according to claim 1, wherein said means for allowing the fuel flow from said pressure chamber to sAid inner chamber comprises a normally closed check valve having an outlet and having a movable element biased by a control spring member in one direction, the fuel pressure within said pressure chamber acting to exert a force on said valve control element tending to move it in the opposite direction, whereby said check valve is opened when the fuel pressure exceeds a predetermined value.
Claim 7
Dependent Claim
39 words
An exhaust gas after-burning system according to claim 5, wherein the outlet of said check valve has a nozzle for injecting fuel into the inner chamber of said reactor in a sprayed form when said check valve remains opened.
Claim 8
Dependent Claim
62 words
An exhaust gas after-burning system according to claim 1, wherein said means for controlling the return flow of the fuel from said pressure chamber to said fuel reservoir comprises a solenoid valve provided between said pressure chamber defining means and said fuel reservoir, and a control device adapted to energize said solenoid valve to open the same in accordance with engine loads.
Claim 9
Dependent Claim
63 words
An exhaust gas after-burning system according to claim 7, wherein said control device comprises an oscillation circuit for generating pulses of an equal duration at a predetermined repetition frequency, a pulse width control circuit for varying the width of the pulses generated by said oscillation circuit in accordance with engine loads, and an amplifier for amplifying the pulses to energize said solenoid valve.
Claim 10
Dependent Claim
33 words
An exhaust gas after-burning system according to claim 8, wherein said pulse width control circuit is responsive to throttle valve opening to vary the width of the pulses generated by said oscillation circuit.
Claim 11
Dependent Claim
71 words
An exhaust gas after-burning system according to claim 1, wherein said fuel supplying means further comprises a by-pass conduit connecting said pressure chamber directly to said fuel reservoir, a normally closed solenoid valve provided in said by-pass conduit, said solenoid valve being adapted to be opened to allow the return flow of the fuel from said pressure chamber to said fuel reservoir through said by-pass conduit when the engine is off.
Claim 12
Dependent Claim
49 words
An exhaust gas after-burning system according to claim 1, wherein said igniting means comprises an ignition plug mounted in said reactor to fire the combustible mixture of the fuel and air, and an ignition device for supplying high-voltage surges of current having a predetermined frequency to said ignition plug.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-06 | 1977-02-05 | 1977-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-06 | 1981-02-05 | 1981-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-06 | 1985-02-05 | 1985-08-07 | $7700.00 | Window Closed / Lapsed |