Method and apparatus to reduce noxious components in the exhaust emissions of internal combustion engines

Claim 2

Method to reduce the noxious components in the exhaust emission of internal combustion engines having an air-fuel proportion adjustment means, and including an integrating controller carrying out the step of regulating the mass-ratio of air and fuel being applied to the internal combustion engine, utilizing the steps of sensing the composition of exhaust emission and derviving a sensing signal; integrating the sensing signal and derving a fuel-air ratio control signal; sensing an operating parameter, or condition of the engine; and wherein the improvement comprises the steps of changing the control range of the control of air-fuel proportion as a function of change of the sensed operating parameter beyond a predetermined limit.

Claim 3

Method according to claim 1 wherein the apparatus includes a fuel-air mass control means; wherEin the step of changing the control range of the air-fuel proportion comprises the step of changing the base setting of said control means.

Claim 4

Method according to claim 2 wherein said control means comprises a fuel injection apparatus; and said step of changing the control range comprises changing the base setting affecting the operating time of the injection system, during which fuel is injected.

Claim 5

Method according to claim 2 wherein the control means comprises a carburetor system supplying a predetermined amount of fuel for a predetermined amount of air flow to the induction duct of the internal combustion engine, wherein said step of changing the control range of the air-fuel proportion comprises changing the base setting of at least one of: air flow; fuel flow; of the carburetor system.

Claim 6

Method according to claim 1 wherein the step of sensing an operating parameter of the engine comprises sensing a threshold level corresponding to said limit of the integrated fuel-air ratio control signal; and the step of changing the control range of the proportion of air and fuel comprises the step of abruptly changing the operating range in a positive, or negative direction if an upper, or lower sensed threshold level is exceeded.

Claim 7

Apparatus to reduce the noxious components in the exhaust emission of internal combustion engines comprising means controlling the mass ratio of air and fuel being supplied to the internal combustion engine; means including an exhaust gas sensor (22)B sensing operating parameters of the engine, including the compositon of exhaust gases therefrom; and means (24) including an integrator (47,50) connected to and controlled by said exhaust gas sensor and providing an integrated output signal representative of deviation of the signal from the exhaust gas sensor from a predetermined value, said output signal being applied to said mass ratio control means to affect the proportion of air and fuel being applied to the internal combustion engine to re-establish exhaust gas emission from the engine resulting in a predetermined output signal; the improvement wherein the engine operating parameter or condition sensing means includes limit sensing means (105,205) connected to said means controlling the mass ratio of air-fuel supplied to the internal combustion engine to change the base setting thereof and thus change the control range in which said integrated output signal becomes effective when the integrated signal reaches a predetermined limit as sensed by said limited sensing means.

Claim 8

Apparatus to reduce the noxious components in the exhaust emission of internal combustion engines comprising means controlling the mass ratio of air and fuel being supplied to the internal combustion engine; means including an exhaust gas sensor (22)B sensing operating parameters of the engine, including the compositon of exhaust gases therefrom; and means (24) including an integrator (47,50) connected to and controlled by said exhaust gas sensor and providing an integrated output signal representative of deviation of the signal from the exhaust gas sensor from a predetermined value, said output signal being applied to said mass ratio control means to affect the proportion of air and fuel being applied to the internal combustion engine to re-establish exhaust gas emission from the engine resulting in a predetermined output signal; the improvement wherein the engine operating parameter or condition sensing means includes limit sensing means (105,205) connected to said means controlling the mass ratio of air-fuel supplied to the internal combustion engine to change the base setting thereof and thus change the control range in which said integrated output signal becomes effective when the integrated signal reaches a predetermined limit as sensed by said limited sensing means.

Claim 9

Apparatus according to claim 6 wherein said limit sensing means comprises a threshold switch (105,205), having upper and lower threshold sensing levels and providing an output signal to change the base setting of said mass ratio control means, in either direction, if the upper, or lower threshold is exceeded.

Claim 10

Apparatus according to claim 7 wherein the means controlling the mass ratio of air and fuel supplied to the engine comprises a fuel injection system; and said threshold switch changes a circuit parameter within the fuel injection system in the circuit thereof affecting the duration of injection time of fuel, in a direction to lengthen, or to shorten said injection time to extend the control range of said fuel injection system.

Claim 11

Apparatus according to claim 7 wherein said means controlling the mass ratio of air and fuel being supplied to the engine comprises a carburetor system; electrical-mechanical transducer means are provided, said transducer means having an output controlling the base setting of at least one of: air flow; fuel flow of the carburetor system, said threshold switch energizing said transducer, to increase, or decrease the base setting of a base quantity of air, or fuel, respectively, upon response of the threshold switch, indicative that the normal control range of the carburetor system should be changed.

Claim 12

Apparatus according to claim 6 wherein said means sensing an opErating parameter of the engine comprises means responsive to changes in the exhaust gas composition, from a predetermined value, over a time.