US3827237A — Method and apparatus for removal of noxious compo…

Claim 1

Independent Claim 143 words

Method to remove noxious components from the exhaust gases of an internal combustion (IC) engine, having an oxidizing reactor to oxidize hydrocarbons (HC) and carbon monoxide (CO) and a reducing reactor to reduce nitrogen oxygen (NOx) compounds, serially connected in the exhaust system of the engine, said method comprising deriving (40) a sensed temperature signal representative of temperature in the exhaust system of the engine; admittIng air to the exhaust system of the engine; controlling the admission of air to the exhaust system of the engine under control of the temperature signal; deriving (41) a sensed oxygen signal representative of whether the gases in the exhaust system of the engine are reducing or oxidizing; and controlling the mass ratio of air to fuel (air number lambda ) of the air-fuel mixture being supplied to the engine intake under control of said oxygen signal.

Claim 2

Dependent Claim 143 words

Method to remove noxious components from the exhaust gases of an internal combustion (IC) engine, having an oxidizing reactor to oxidize hydrocarbons (HC) and carbon monoxide (CO) and a reducing reactor to reduce nitrogen oxygen (NOx) compounds, serially connected in the exhaust system of the engine, said method comprising deriving (40) a sensed temperature signal representative of temperature in the exhaust system of the engine; admittIng air to the exhaust system of the engine; controlling the admission of air to the exhaust system of the engine under control of the temperature signal; deriving (41) a sensed oxygen signal representative of whether the gases in the exhaust system of the engine are reducing or oxidizing; and controlling the mass ratio of air to fuel (air number lambda ) of the air-fuel mixture being supplied to the engine intake under control of said oxygen signal.

Claim 3

Dependent Claim 31 words

Method according to claim 1 wherein the step of admitting air to the exhaust system of the engine comprises the step of adding air into the exhaust system of the engine.

Claim 4

Dependent Claim 38 words

Method according to claim 1, wherein the step of admitting air to the exhaust system of the engine comprises the step of adding additional air to the intake of at least some of the cylinders of the engine.

Claim 5

Dependent Claim 140 words

Method according to claim 1, wherein the step of controlling the admission of air comprises adding additional air if the temperature signal is indicative of an exhaust system temperature below the operating temperature of at least one of the reactors; and the step of controlling the mass ratio of the combined air and fuel components of the air-fuel mixture being fed to the engine comprises the step of controlling at least one of said components until the sensed oXygen signal is indicative of an air number of about lambda 0.98, so that, when the exhaust system is below operating temperature, additional air will be admitted, causing additional fuel to be admitted and the additional air-fuel quantities available in the exhaust system will thermally react therein and thus rapidly increase the operating temperature of the exhaust system of the reactors therein.

Claim 6

Dependent Claim 197 words

System to remove noxious components from the exhaust of an internal combustion engine in which the engine is connected to an exhaust system having a series connection of a first reactor (23) to oxidize unburned hydrocarbons and carbon monoxide, and a second reactor to reduce NOx components, comprising a temperature sensing element (40) in thermally conductive relation to the exhaust system of the engine and delivering a sensed temperature signal representative of temperature in the exhaust system of the engine; means (32, 33, 34) admitting air in addition to the engine operating requirements to the exhaust system of the engine; means (42, 43; 35, 54, 55, 36, 61, 72, 87, 45a, 45b) controlling the admission of additional air as a function of said temperature signal; an oxygen sensing element (41) delivering a sensed oxygen signal representative of oxygen content in the exhaust system of the engine; means (12, 13, 19, 20, 59, 60, 73, 74, 75, 76) admitting air and fuel to the engine; and means (41, 44, 45, 18, 22, 53, 57, 72) controlling the air number ( lambda ) of the air-fuel mixture being applied to the engine as a function of said oxygen signal.

Claim 7

Dependent Claim 197 words

System to remove noxious components from the exhaust of an internal combustion engine in which the engine is connected to an exhaust system having a series connection of a first reactor (23) to oxidize unburned hydrocarbons and carbon monoxide, and a second reactor to reduce NOx components, comprising a temperature sensing element (40) in thermally conductive relation to the exhaust system of the engine and delivering a sensed temperature signal representative of temperature in the exhaust system of the engine; means (32, 33, 34) admitting air in addition to the engine operating requirements to the exhaust system of the engine; means (42, 43; 35, 54, 55, 36, 61, 72, 87, 45a, 45b) controlling the admission of additional air as a function of said temperature signal; an oxygen sensing element (41) delivering a sensed oxygen signal representative of oxygen content in the exhaust system of the engine; means (12, 13, 19, 20, 59, 60, 73, 74, 75, 76) admitting air and fuel to the engine; and means (41, 44, 45, 18, 22, 53, 57, 72) controlling the air number ( lambda ) of the air-fuel mixture being applied to the engine as a function of said oxygen signal.

Claim 8

Dependent Claim 32 words

System according to claim 5 wherein the means admitting air in addition to engine operating requirements comprises means (32, 33, 34, 37) adding additional air to the exhaust manifold of the engine.

Claim 9

Dependent Claim 46 words

System according to claim 6, further comprising a secondary air pump (32), duct means (34) interconnecting the pump (32) and the exhaust manifold (24-27; 23) of the engine and terminating close to the exhaust valve thereof; and check valve means (37) in the duct means (34).

Claim 10

Dependent Claim 19 words

System according to claim 6, further comprising a secondary air filter (33) in advance of the secondary air pump.

Claim 11

Dependent Claim 20 words

System according to claim 7 comprising means driving the pump (32) from the crank shaft (31) of the engine (11).

Claim 12

Dependent Claim 23 words

System according to claim 9, wherein the driving means between the crank shaft (31) and the pump (32) comprises an electromagnetic coupling (61).

Claim 13

Dependent Claim 24 words

System according to claim 7, wherein the means controlling the admission of additional air comprises means controlling operation of the secondary air pump (32).

Claim 14

Dependent Claim 27 words

System according to claim 7 including connection means interconnecting the inlet to the secondary air pump (32) with the inlet pipe (13) of the IC engine (11).

Claim 15

Dependent Claim 38 words

System according to claim 7, wherein the means controlling the admission of additional air includes a control amplifier (42) and a threshold switch (43), the output of the threshold switch controlling operation of said additional air pump (32).

Claim 16

Dependent Claim 78 words

System according to claim 6, wherein the means controlling the admission of additional air comprises a first control loop including said temperature sensing element (40), a control amplifier (42) and a threshold switch (43); air pressure means supplying air under pressure; and controlled valve means (35) connecting said air pressure means to said means admitting additional air to the exhaust manifold of the engine, said controlled valve means being connected to and controlled by said threshold switch (43).

Claim 17

Dependent Claim 27 words

System according to claim 14, further comprising variable means (36), and means connecting the variation control of said variable valve means (36) to said control amplifier (42).

Claim 18

Dependent Claim 66 words

System according to claim 6, comprising a secondary air pump (32) connected to the means admitting additional air to the exhaust system of the engine; an electric motor (55) driving said secondary air pump; and wherein the means controlling the admission of additional air as a function of said temperature sensed signal comprises a control amplifier (54) connected to and controlling operation of the motor (55).

Claim 19

Dependent Claim 15 words

System according to claim 16 wherein said control amplifier controls the speed of said motor.

Claim 20

Dependent Claim 33 words

System according to claim 5, wherein the means controlling the air number ( lambda ) comprises a control loop including a series circuit comprising an amplifier (45) and said oxygen sensing element (45).

Claim 21

Dependent Claim 71 words

System according to claim 18, wherein the means admitting air and fuel to the engine intake comprises a carburetor system including a fuel nozzle (19) and a throttle (18), and an air duct (21) terminating downstream of said throttle and taking in ambient air; and electromagnetically operable valve means (22) located to control air flow through said air duct (21), and being controlled by the output of said control amplifier (45).

Claim 22

Dependent Claim 65 words

System according to claim 18, wherein the means admitting air and fuel to the engine intake comprises a carburetor system including a fuel nozzle (19), a throttle (18) and fuel supply means (20) supplying fuel to the fuel nozzle (19); and electromagnetically controllable valve means (53) controlling fuel flow to said nozzle, said valve means being controlled by and connected to said control amplifier (45).

Claim 23

Dependent Claim 115 words

System according to claim 18, wherein the means admitting air and fuel to the engine intake comprises an air inlet manifold (13) and a throttle (18) and a fuel injection system including at least one injection nozzle (59), and a control switching circuit (57) connected to and energizing the injection nozzle (59) for predetermined periods of time depending on engine operation parameters, said control switching circuit having a control input (B) to influence said energization period; the output of said control amplifier being connected to said energization control input (B) to additionally control the time duration of opening of the fuel injection nozzle in dependence on sensed oxygen levels in the exhaust of the engine.

Claim 24

Dependent Claim 53 words

System according to claim 21, including an air mass measuring device (58) located in the inlet manifold upstream of the throttle (18) and having an electrical output; said electrical output being connected to said control switching circuit (57) to affect the pulse duration of the fuel injection pulse connected to the injection nozzle.

Claim 25

Dependent Claim 76 words

System according to claim 22, wherein said control switching circuit includes two switching stages, one switching stage providing a part-switching pulse and the second switching stage providing an extending pulse, the duration of which is a function of said part-switching pulse; said air flow measuring device being connected to said first switching stage to control the length of said part-switching pulse, said part-switching pulse and said extending pulse conjointly controlling the opening of said injection nozzle.

Claim 26

Dependent Claim 156 words

System according to claim 5, for use with multi-cylinder engines, wherein the cylinders of the engine are divided into two groups, of at least on cylinder each, wherein the means admitting additional air and the means controlling the admission of additional air comprises one of said cylinder groups and means responsive to said temperature signal to admit additional fuel to said cylinder group so that unburned CO and HC will be present in the exhaust from said first cylinder group, and the means controlling the air-fuel mixture comprises the other of said cylinder groups and means responsive to said oxygen signal to decrease the amount of fuel being admitted to said second cylinder group below the stoichiometric value so that excess oxygen will be present in the exhaust from said second cylinder group, the excess oxygen from said second cylinder group burning the unburned CO and HC from said first cylinder group in the first reactor.

Claim 27

Dependent Claim 92 words

System according to claim 24, includinG at least one fuel injection valve (73, 74) associated with each cylinder group, and a control switching circuit (72) alternately energizing said injection valves, said control switching circuit having a pair of outputs (E, F), each being connected to one of the fuel injection valves; and a control amplifier (45) interconnecting the oxygen sensing element (41) and said control switching circuit (72) to affect the switching duration, and hence the injection period of a selected one if said injection valves in accordance with sensed oxygen signal.

Claim 28

Dependent Claim 58 words

System according to claim 25, further comprising an air mass measuring device (58) interposed in the inlet manifold to the engine and having an electrical output, said electrical output being connected to said control switching circuit (72) to affect the pulse duration of all switching pulses derived from said control switching circuit and applied to said injection valves.

Claim 29

Dependent Claim 58 words

System according to claim 25, comprising a pulse source (69) controlling said control switching circuit to provide pulses in synchronism with engine rotation; a bistable circuit (77) alternately energizing the fuel injection valves associated with said two groups of cylinders; and logic circuit means (OR-gate 66, AND-gate 79, AND-gate 80) connecting the switching circuit (72) and the valves.

Claim 30

Dependent Claim 47 words

System according to claim 27, wherein said logic circuit includes AND-gates (79, 80) and the injection valves associated with the respective groups are connected to and controlled, respectively, by said AND-gates, said AND-gates being selectively energized in accordance with the changing of state of said bistable circuit.

Claim 31

Dependent Claim 81 words

System according to claim 25, wherein said means responsive to said oxygen signal further comprises a control amplifier (45) connected to and controlled by said oxygen sensing element (41); said control switching circuit (72) having a control input responsive to signals and controlling, in response to such signals, the pulse duration of the output pulse provided by said control switching circuit (72) to a respective fuel injection valve; and an adder resistor (92) interconnecting the control amplifier and said control input.

Claim 32

Dependent Claim 107 words

System according to claim 29, wherein the means controlling admission of additional air comprises a control amplifier (42) connected to and controlled by said temperature sensing element (40, two adder resistors (93, 94) and means connecting one of said adder resistors to the control input of said control switching circuit and inverter means connecting the other adder resistor to said control input of the control switching circuit; and alternately operable switching means (88, 89) alternately switching one or the other of said two adder resistors in circuit with said control switching input, in synchronism with alternate energization of the injection valves associated with the respective cylinder groups.

Claim 33

Dependent Claim 109 words

System according to claim 24, including two carburetor systems (18a, 19a; 18b, 19b) one, each, being associated with a respective cylinder group; pair of control amplifiers (45a, 45b), one each being associated with one of said carburetor systems and controlling the proportion of the air-fuel mixture being applied to the engine from each said carburetor systems as a function of one of said sensed signals; and wherein the means responsive to said temperature signal comprises a control amplifier (42) and an inverter amplifier (87), connected in series, and responsive to the other of said sensed signals, and differentially controlling the air-fuel ratio being mixed by said respective carburetor systems.

Claim 34

Dependent Claim 27 words

System according to claim 31, wherein the first of said sensed signals is the oxygen signal and the other of said sensed signals is the temperature signal.

Claim 35

Dependent Claim 123 words

System according to claim 31, including an amplifier (44) connected to the oxygen sensing element to provide an amplified oxygen sensed signal; a pair of adder resistors (100, 101) connected between the input of said control amplifiers; an amplifier connected to the output of said temperature sensing element (40), an adder resistor (102) interconnecting the output of said amplifier (42) and the input of one of said control amplifiers (45a) and an inverter amplifier (87) connected to the output of said amplifier (42), an adder resistor (103) connecting the output of said inverter amplifiers to the input of the other of said control amplifiers, the output of said oxygen sensing amplifier (44) being applied to the input of said adder resistors (100, 101).

Claim 36

Dependent Claim 23 words

System according to claim 5, wherein the first reactor (28) is a thermo reactor and the second reactor (29) is a catalytic reactor.

Claim 37

Dependent Claim 44 words

System according to claim 5, wherein the first reactor is a thermo reactor and comprises a portion of the exhaust manifold and exhaust stubs (23; 24, 25, 26, 27) of the engine, said exhaust manifold and exhaust stubs having a thermally insulating wall (71).

Claim 38

Dependent Claim 98 words

System according to claim 5, wherein the means controlling the admission of additional air and the means controlling the air number ( lambda ) comprises a control switching circuit, means (58) sensing the air quantity being introduced to the engine and providing an electrical control signal, said control signal being connected to said control switching means (57); air pump means (32) providing said additional air to the exhaust system of the engine, and air inlet means (62) connected to said pump downstream of said air flow sensing means (58) and ahead of the throttle (18) for the engine.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1977-08-05	1978-02-04	1978-08-06	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1981-08-05	1982-02-04	1982-08-06	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1985-08-05	1986-02-04	1986-08-06	$7700.00	Window Closed / Lapsed

Method and apparatus for removal of noxious components from the exhaust of internal combustion engines

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