Air-fuel ratio controlling system

Claim 2

In an air-fuel ratio controlling apparatus for an internal combustion engine including: a combustion chamber for producing a power therein, an intake system operatively communicated with said combustion chamber for supplying thereto air-fuel mixture, an exhaust system operatively communicated with said combustion chamber for conveying exhaust gas from said combustion chamber to the atmosphere, said exhaust system including means for purifying said exhaust gas, additional air supplying pipe communicated with at least one of said systems for supplying additional air thereto, air-fuel ratio detecting means disposed in said exhaust system for detecting air-fuel ratio of the air-fuel mixture supplied with the additional air, control means operatively disposed in said additional air supplying pipe for variably controlling the amount of the additional air to be supplied, drive means operatively connected with said control means for driving the same, and a control circuit electrically connected with said air-fuel ratio detecting means and said drive means for actuating said drive means in response to the detected air-fuel ratio, said control circuit comprising: a timing pulse generator for generating timing pulses in a timed relationship with a running speed of said engine; and an actuating circuit for intermittently actuating said drive means upon receiving said timing pulses, said actuating circuit being actuated for a predetermined period of time at each of said timing pulses, whereby the amount of the additional air is intermittently controlled in accordance with the detected air-fuel ratio.

Claim 3

A control circuit according to claim 1 further comprising, means for changing a frequency of said timing pulses during a rapid change of the operational condition of said engine.

Claim 4

In an air-fuel ratio controlling apparatus for an internal combustion engine including: a combustion chamber for producing a power therein, an intake system operatively communicated with said combustion chamber for supplying thereto air-fuel mixture, an exhaust system operatively communicated with said combustion chamber for conveying exhaust gas from said combustion chamber to the atmosphere, said exhaust system including means for purifying said exhaust gas, additional air supplying pipe communicated with at least one of said systems for supplying additional air thereto, air-fuel ratio detecting means disposed in said exhaust system for detecting air-fuel ratio of the air-fuel mixture supplied with the additional air, control means operatively disposed in said additional air supplying pipe for variably controlling the amount of the additional air to be supplied, drive means operatively connected with said control means for driving the same, and a control circuit electrically connected with said air-fuel ratio detecting means and said drive means for actuating said drive means in response to the detected air-fuel ratio, said control circuit comprising: a timing pulse generator for generating timing pulses in a timed relationship with a running speed of said engine; an actuating circuit for intermittently actuating said drive means upon receiving said timing pulses, whereby the amount of the additional air is intermittently controlled in accordance with the detected air-fuel ratio, operation detecting means for detecting and producing a signal during periods of rapid change in the operational condition of said engine; and means for altering the rate of change in the amount the additional air per said timing pulse in response to said signal.

Claim 5

In an air-fuel ratio controlling apparatus for an internal combustion engine including: a combustion chamber for producing a power therein, an intake system operatively communicated with said combustion chamber for supplying thereto air-fuel mixture, an exhaust system operatively communicated with said combustion chamber for conveying exhaust gas from said combustion chamber to the atmosphere, said exhaust system including means for purifying said exhaust gas, additional air supplying pipe communicated with at least one of said systems for supplying additional air thereto, air-fuel ratio detecting means disposed in said exhaust system for detecting air-fuel ratio of the air-fuel mixture supplied with the additional air, control means operatively disposed in said additional air supplying pipe for variably controlling the amount of the additional air to be supplied, drive means operatively connected with said control means for driving the same, and a control circuit electrically connected with said air-fuel ratio detecting means and said drive means for actuating said drive means in response to the detected air-fuel ratio, said control circuit comprising: a timing pulse generator for generating timing pulses in a timed relationship with a running speed of said engine; an actuating circuit for intermittently actuating said drive means upon receiving said timing pulses, whereby the amount of the additional air is intermittently controlled in accordance with the detected air-fuel ratio, operation detecting means for detecting and producing a signal during periods of rapid change in the operational condition of said engine; and means for altering the rate of change in the amount the additional air per said timing pulse in response to said signal.

Claim 6

A control circuit according to claim 1, wherein said timing pulse generator also generates timing pulses when the output from said air-fuel ratio detecting means is changed.

Claim 7

A control circuit according to claim 1 further comprising, means for changing a rate of a moving degree of said control means disposed in said additional air supplying pipe in one direction per said timing pulse to a moving degree of said control means in the other direction.

Claim 8

Apparatus as in claim 1 wherein said purifying means comprises a catalytic converter.

Claim 9

Apparatus as in claim 3 wherein said purifying means comprises a catalytic converter.

Claim 10

In an air-fuel ratio controlling apparatus for an internal combustion engine including: a combustion chamber for producing a power therein, an intake system operatively communicated with said combustion chamber for supplying thereto air-fuel mixture, an exhaust system operatively communicated with said combustion chamber for conveying exhaust gas from said combustion chamber to the atmosphere, additional air supplying pipe communicated with said intake system for supplying additional air thereto, air-fuel ratio detecting means disposed in said exhaust system for detecting air-fuel ratio of the air-fuel mixture supplied with the additional air, control means operatively disposed in said additional air supplying pipe for variably controlling the amount of the additional air to be supplied, drive means operatively connected with said control means for driving the same, and a control circuit electrically connected with said air-fuel ratio detecting means and said drive means for actuating said drive means in response to the detected air-fuel ratio, said control circuit comprising: a timing pulse generator for generating timing pulses in a timed relationship with a running speed of said engine; and an actuating circuit for intermittently actuating said drive means upon receiving said timing pulses, said actuating circuit being actuated for a predetermined period of time at each of said timing pulses, whereby the amount of the additional air is intermittently controlled in accordance with the detected air-fuel ratio.

Claim 11

In an air-fuel ratio controlling apparatus for an internal combustion engine including: a combustion chamber for producing a power therein, an intake system operatively communicated with said combustion chamber for supplying thereto air-fuel mixture, an exhaust system operatively communicated with said combustion chamber for conveying exhaust gas from said combustion chamber to the atmosphere, additional air supplying pipe communicated with said intake system for supplying additional air thereto, air-fuel ratio detecting means disposed in said exhaust system for detecting air-fuel ratio of the air-fuel mixture supplied with the additional air, control means operatively disposed in said additional air supplying pipe for variably controlling the amount of the additional air to be supplied, drive means operatively connected with said control means for driving the same, and a control circuit electrically connected with said air-fuel ratio detecting means and said drive means for actuating said drive means in response to the detected air-fuel ratio, said control circuit comprising: a timing pulse generator for generating timing pulses in a timed relationship with a running speed of said engine; and an actuating circuit for intermittently actuating said drive means upon receiving said timing pulses, said actuating circuit being actuated for a predetermined period of time at each of said timing pulses, whereby the amount of the additional air is intermittently controlled in accordance with the detected air-fuel ratio.

Claim 12

A control circuit according to claim 8 further comprising, means for changing a frequency of said timing pulses during a rapid change of the operational condition of said engine.

Claim 13

A control circuit according to claim 8, wherein said timing pulse generator also generates timing pulses when the output from said air-fuel ratio detecting means is changed.

Claim 14

A control circuit according to claim 8 further comprising, means for changing a rate of a moving degree of said control means disposed in said additional air supplying pipe in one direction per said timing pulse to a moving degree of said control means in the other direction.

Claim 15

In an air-fuel ratio controlling apparatus for an internal combustion engine including: a combustion chamber for producing a power therein, an intake system operatively communicated with said combustion chamber for supplying thereto air-fuel mixture, an exhaust system operatively communicated with said combustion chamber for conveying exhaust gas from said combustion chamber to the atmosphere, additional air supplying pipe communicated with said intake system for supplying additional air thereto, air-fuel ratio detecting means disposed in said exhaust system for detecting air-fuel ratio of the air-fuel mixture supplied with the additional air, control means operatively disposed in said additional air supplying pipe for variably controlling the amount of the additional air to be supplied, drive means operatively connected with said control means for driving the same, and a control circuit electrically connected with said air-fuel ratio detecting means and said drive means for actuating said drive means in response to the detected air-fuel ratio, said control circuit comprising: a timing pulse generator for generating timing pulses in a timed relationship with a running speed of said engine; an actuating circuit for intermittently actuating said drive means upon receiving said timing pulses, whereby the amount of the additional air is intermittently controlled in accordance with the detected air-fuel ratio, operation detecting means for detecting and producing a signal during periods of rapid change in the operational condition of said engine; and means for altering the rate of change in the amount the additional air per said timing pulse in response to said signal.

Claim 16

In an air-fuel ratio controlling apparatus for an internal combustion engine including: a combustion chamber for producing a power therein, an intake system operatively communicated with said combustion chamber for supplying thereto air-fuel mixture, an exhaust system operatively communicated with said combustion chamber for conveying exhaust gas from said combustion chamber to the atmosphere, additional air supplying pipe communicated with said intake system for supplying additional air thereto, air-fuel ratio detecting means disposed in said exhaust system for detecting air-fuel ratio of the air-fuel mixture supplied with the additional air, control means operatively disposed in said additional air supplying pipe for variably controlling the amount of the additional air to be supplied, drive means operatively connected with said control means for driving the same, and a control circuit electrically connected with said air-fuel ratio detecting means and said drive means for actuating said drive means in response to the detected air-fuel ratio, said control circuit comprising: a timing pulse generator for generating timing pulses in a timed relationship with a running speed of said engine; an actuating circuit for intermittently actuating said drive means upon receiving said timing pulses, whereby the amount of the additional air is intermittently controlled in accordance with the detected air-fuel ratio, operation detecting means for detecting and producing a signal during periods of rapid change in the operational condition of said engine; and means for altering the rate of change in the amount the additional air per said timing pulse in response to said signal.

Claim 17

A control circuit according to claim 12 further comprising, means for changing a frequency of said timing pulses during a rapid change of the operational condition of said engine.

Claim 18

A control circuit according to claim 12, wherein said timing pulse generator also generates timing pulses when the output from said air-fuel ratio detecting means is changed.

Claim 19

A control circuit according to claim 12 further comprising, means for changing a rate of a moving degree of said control means disposed in said additional air supplying pipe in one direction per said timing pulse to a moving degree of said control means in the other direction.