US4007719A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for the detoxification of exhaust gases
Assignee: Robert Bosch GmbH
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Filing: 1975-12-30
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Granted: 1977-02-15
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Expires: 1995-12-30
Abstract
Abstract An apparatus for the detoxification of exhaust gases of an internal combustion engine having a fuel metering mechanism, such as a carburetor, which meters out fuel corresponding to the air quantity, is described. An air quantity measuring device is provided which controls the metering mechanism so as to achieve a slightly enriched fuel-air mixture. Thus, the air number (λ) is initially maintained at less than 1, the air number 1 designating a stoichiometric fuel-air mixture. Secondary air is admitted via a secondary air pump, an oxygen sensor being disposed on the exhaust side, until such time an optimum of fuel-air mixture is reached. The secondary air is admitted into the suction tube of the internal combustion engine downstream of the air measuring device.
Inventors
- 👤 Johannes Brettschneider
- 👤 Lorenz Bundesen
- 👤 Heinrich Knapp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:24
CPC Classifications
F; F02; F02D; F02D21/00; F02D21/06; F02D21/10; F02D35/00; F02D35/0015; F02D35/0023; F02D35/0038; F02D41/00; F02D41/02; F02D41/14; F02D41/1438; F02D41/1444; F02D41/1454; F02D41/1456
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
305 words
In an apparatus for the detoxification of exhaust gases of an internal combustion engine having (a) a suction tube for air intake to the engine, (b) an air quantity measuring device disposed in said suction tube, (c) fuel metering means for metering out fuel corresponding to the air quantity measured by said air quantity measuring device so as to achieve slightly enriched fuel-air mixture, (d) an exhaust system for the exhaust gases of the engine, and (e) an oxygen sensing means disposed in said exhaust system, the improvement comprising: (f) a secondary pump, (g) means including a secondary air line connected between said secondary air pump and an inlet to said suction tube downstream of said air quantity measuring device, and (h) means connected to and controlled by said oxygen sensing means and connected to said means including said secondary air line for controlling the admission of secondary air from the secondary air pump to the suction tube through said secondary air line, until such time as an optimum value of air number is reached, wherein said means for controlling the admission of secondary air includes: i. a magnetic valve means disposed within said secondary air line; and ii. a control device electrically disposed between said magnetic valve means and said oxygen sensing means for amplifying the output voltage of said oxygen sensing means and cyclically controlling said magnetic valve means proportionally to said amplified output voltage, wherein the opening point of said magnetic valve means is cyclically controlled by said control device at a frequency proportional to the engine rpm, in dependence on a signal fed to said control device by an engine rpm measuring means, and wherein the duration of opening of said magnetic valve means is controlled by said control device in dependence on the output voltage of said oxygen sensing means.
Claim 2
Dependent Claim
305 words
In an apparatus for the detoxification of exhaust gases of an internal combustion engine having (a) a suction tube for air intake to the engine, (b) an air quantity measuring device disposed in said suction tube, (c) fuel metering means for metering out fuel corresponding to the air quantity measured by said air quantity measuring device so as to achieve slightly enriched fuel-air mixture, (d) an exhaust system for the exhaust gases of the engine, and (e) an oxygen sensing means disposed in said exhaust system, the improvement comprising: (f) a secondary pump, (g) means including a secondary air line connected between said secondary air pump and an inlet to said suction tube downstream of said air quantity measuring device, and (h) means connected to and controlled by said oxygen sensing means and connected to said means including said secondary air line for controlling the admission of secondary air from the secondary air pump to the suction tube through said secondary air line, until such time as an optimum value of air number is reached, wherein said means for controlling the admission of secondary air includes: i. a magnetic valve means disposed within said secondary air line; and ii. a control device electrically disposed between said magnetic valve means and said oxygen sensing means for amplifying the output voltage of said oxygen sensing means and cyclically controlling said magnetic valve means proportionally to said amplified output voltage, wherein the opening point of said magnetic valve means is cyclically controlled by said control device at a frequency proportional to the engine rpm, in dependence on a signal fed to said control device by an engine rpm measuring means, and wherein the duration of opening of said magnetic valve means is controlled by said control device in dependence on the output voltage of said oxygen sensing means.
Claim 3
Dependent Claim
16 words
An apparatus according to claim 1, wherein the motor rpm measuring means is an ignition distributor.
Claim 4
Dependent Claim
240 words
In an apparatus for the detoxification of exhaust gases of an internal combustion engine having (a) a suction tube for air intake to the engine, (b) an air quantity measuring device disposed in said suction tube, (c) fuel metering means for metering out fuel corresponding to the air quantity measured by said air quantity measuring device so as to achieve a slightly enriched fuel-air mixture, (d) an exhaust system for the exhaust gases of the engine, and (e) an oxygen sensing means disposed in said exhaust system, the improvement comprising: (f) a secondary pump, (g) means including a secondary air line connected between said secondary air pump and an inlet to said suction tube downstream of said air quantity measuring device, (h) means connected to and controlled by said oxygen sensing means and connected to said means including said secondary air line for controlling the admission of secondary air from the secondary air pump to the suction tube through said secondary air line, until such time as an optimum value of air number is reached, and (i) a differential pressure control valve means disposed within said secondary air line so that the connections of the secondary air line to the differential pressure control valve means are unobstructed, said differential pressure control valve means serving to maintain pressure of secondary air higher than absolute pressure prevailing in said suction tube ahead of the secondary air inlet by a predetermined, changeable amount.
Claim 5
Dependent Claim
240 words
In an apparatus for the detoxification of exhaust gases of an internal combustion engine having (a) a suction tube for air intake to the engine, (b) an air quantity measuring device disposed in said suction tube, (c) fuel metering means for metering out fuel corresponding to the air quantity measured by said air quantity measuring device so as to achieve a slightly enriched fuel-air mixture, (d) an exhaust system for the exhaust gases of the engine, and (e) an oxygen sensing means disposed in said exhaust system, the improvement comprising: (f) a secondary pump, (g) means including a secondary air line connected between said secondary air pump and an inlet to said suction tube downstream of said air quantity measuring device, (h) means connected to and controlled by said oxygen sensing means and connected to said means including said secondary air line for controlling the admission of secondary air from the secondary air pump to the suction tube through said secondary air line, until such time as an optimum value of air number is reached, and (i) a differential pressure control valve means disposed within said secondary air line so that the connections of the secondary air line to the differential pressure control valve means are unobstructed, said differential pressure control valve means serving to maintain pressure of secondary air higher than absolute pressure prevailing in said suction tube ahead of the secondary air inlet by a predetermined, changeable amount.
Claim 6
Dependent Claim
32 words
An apparatus according to claim 3, wherein said differential pressure control valve means includes a control membrane whose one side experiences secondary air pressure and whose other side experiences suction tube pressure.
Claim 7
Dependent Claim
28 words
An apparatus according to claim 4, including a normally fixed valve seat formed by an end of a relief line, and wherein said membrane controls said valve seat.
Claim 8
Dependent Claim
76 words
An apparatus according to claim 4, including a first spring and at least one second spring, and wherein said differential pressure valve means causes a multiplicative increase of secondary air as a function of load and rpm of the internal combustion engine, said valve means including said at least one second spring whose pretension is changeable by means of said separate membrane actuated by suction tube pressure and thus changing the pretension of said first spring.
Claim 9
Dependent Claim
30 words
An apparatus according to claim 3, wherein said differential pressure control valve means includes at least two operating membranes of different effective surface areas which positively cooperate with spring means.
Claim 10
Dependent Claim
23 words
An apparatus according to claim 7, including a screw, and wherein pretension of said spring means is changeable by means of said screw.
Claim 11
Dependent Claim
16 words
An apparatus according to claim 8, wherein said screw is a screw surrounding a relief line.
Claim 12
Dependent Claim
14 words
An apparatus according to claim 11, wherein said fuel metering means comprises a carburetor.
Claim 13
Dependent Claim
177 words
In an apparatus for the detoxification of exhaust gases of an internal combustion engine having (a) a suction tube for air intake to the engine, (b) an air quantity measuring device disposed in said suction tube, (c) fuel metering means for metering out fuel corresponding to the air quantity measured by said air quantity measuring device so as to achieve a slightly enriched fuel-air mixture, (d) an exhaust system for the exhaust gases of the engine, and (e) an oxygen sensing means disposed in said exhaust system, the improvement comprising: (f) a secondary air pump, (g) means including a secondary air line connected between said secondary air pump and an inlet to said suction tube downstream of said air quantity measuring device, (h) means connected to and controlled by said oxygen sensing means and connected to said means including said secondary air line for controlling the admission of secondary air from the secondary air pump to the suction tube through said secondary air line, continuously until such time as an optimum value of air number is reached.
Claim 14
Dependent Claim
177 words
In an apparatus for the detoxification of exhaust gases of an internal combustion engine having (a) a suction tube for air intake to the engine, (b) an air quantity measuring device disposed in said suction tube, (c) fuel metering means for metering out fuel corresponding to the air quantity measured by said air quantity measuring device so as to achieve a slightly enriched fuel-air mixture, (d) an exhaust system for the exhaust gases of the engine, and (e) an oxygen sensing means disposed in said exhaust system, the improvement comprising: (f) a secondary air pump, (g) means including a secondary air line connected between said secondary air pump and an inlet to said suction tube downstream of said air quantity measuring device, (h) means connected to and controlled by said oxygen sensing means and connected to said means including said secondary air line for controlling the admission of secondary air from the secondary air pump to the suction tube through said secondary air line, continuously until such time as an optimum value of air number is reached.
Claim 15
Dependent Claim
86 words
An apparatus according to claim 11, wherein said means connected to said means including said secondary air line for controlling the admission of secondary air from the secondary air pump to the suction tube through said secondary air line includes magnetic valve means disposed within said secondary air line and a control device electrically disposed between said magnetic valve means and said oxygen sensing means for amplifying the output voltage of said oxygen sensing and controlling said magnetic valve means proportionally to said amplifier output voltage.
Claim 16
Dependent Claim
14 words
An apparatus according to claim 12, wherein said valve means operates in analog fashion.
Claim 17
Dependent Claim
12 words
An apparatus according to claim 12, wherein said valve means operates cyclically.
Claim 18
Dependent Claim
37 words
An apparatus according to claim 12, wherein said magnetic valve means is normally closed and can be controlled in the direction of opening (leaning out) so as to achieve the optimum value of air number (stoichiometric mixture).
Claim 19
Dependent Claim
38 words
An apparatus according to claim 12, wherein said magnetic valve means is normally open and is controllable in the direction of closing (an interruption of leaning out) for the purposes of achieving an optimum value of air number.
Claim 20
Dependent Claim
26 words
An apparatus according to claim 15, wherein the duration of opening of said magnetic valve means is affected by the rpm of the internal combustion engine.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-02-15 | 1980-08-16 | 1981-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-15 | 1984-08-16 | 1985-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-15 | 1988-08-16 | 1989-02-15 | $7700.00 | Window Closed / Lapsed |