Engine secondary air flow control valve

Claim 2

An air control valve for use with an internal combustion engine having an air induction system for supplying air to the engine and generating an engine induction vacuum signal, an exhaust system for exhaust gas flow from the engine, a catalytic converter in the exhaust system for promoting oxidation of exhaust gas constituents and an air supply system including an air pump and having a first branch for delivering air to the exhaust system at a point upstream and remote from the catalytic converter and a second branch for delivering air to the catalytic converter, the air control valve comprising, in combination: a valve body defining a valve chamber having an inlet connected to the air pump, a first outlet connected to the first branch, a second outlet connected to the second branch and a third outlet openable to the atmosphere by a pressure relief valve, the valve body further including a pair of axially opposed valve seats in the valve chamber surrounding the first and second outlets; a stem projecting coaxially through the valve seats and valve chamber; first and second valve members slidably disposed on the stem; a spring compressed between the first and second valve members to normally bias the first valve member against the first valve seat to close the first outlet and bias the second valve member against the second valve seat to close the second outlet; an expansible chamber motor comprising a movable wall defining first and second motor chambers in the valve body, the movable wall being responsive to the pressure difference thereacross to assume a central position when the pressure difference is zero and move in one or the other direction from the central position when air pressure in the first motor chamber exceeds that in the second motor chamber or the air pressure in the second motor chamber exceeds that in the first motor chamber, respectively, the movable wall further having the stem attached thereto for comovement, the stem having a first stop effective to engage the first valve member and open the first outlet with movement of the movable wall in the one direction from its central position and a second stop effective to engage the second valve member and open the second outlet with movement of the movable wall in the other direction from its central position; a restricted flow orifice in the valve body opening the first motor chamber to the atmosphere; a valved conduit in the valve body opening the first motor chamber to the valve chamber; a conduit in the stem opening the second motor chamber to the valve chamber; a valved opening in the valve body opening the second motor chamber to the atmosphere; a first actuator responsive to a first signal to close the valved conduit and responsive to a second signal to open the valved conduit; and a second actuator responsive to the engine induction vacuum signal to open the valved opening below a high vacuum signal level and Close the valved opening above the high level.

Claim 3

An air control valve for use with an internal combustion engine having an air induction system effective to generate an engine vacuum signal, an exhaust system for exhaust gas flow from the engine, a catalytic converter in the exhaust system for promoting oxidation of exhaust gas constituents and an air supply system including an air pump and having a first branch for delivering air to the exhaust system at a location upstream and remote from the catalytic converter and a second branch for delivering air to the catalytic converter, the air control valve comprising, in combination: a valve body defining a valve chamber having an inlet connected to the air pump, a first outlet connected to the first branch, a second outlet connected to the second branch, a third outlet to the atmosphere, a first normally closed valve in the first outlet, a second normally closed valve in the second outlet and a pressure relief valve in the third outlet; an expansible chamber motor defining a first motor chamber with a restricted orifice to the atmosphere and a second motor chamber with a valved opening to the atmosphere and including a wall separating the first and second motor chambers, the wall being movable by pressure differences thereacross and including means engageable with the first and second outlet valves to open the first outlet valve when air pressure in the first chamber exceeds that in the second and to open the second outlet valve when air pressure in the second chamber exceeds that in the first; a first conduit connecting the first motor chamber with the valve chamber and including a conduit valve; a second conduit connecting the second motor chamber and the valve chamber; a first actuator responsive to the engine vacuum signal to close the conduit valve below a low vacuum signal level and open the conduit valve above the low level; and a second actuator responsive to engine vacuum to open the second chamber opening valve below a high vacuum signal level and close the second chamber opening valve above the high level.

Claim 4

An air control valve for use with an internal combustion engine having an air induction system effective to generate an engine vacuum signal, an exhaust system for exhaust gas flow from the engine, a catalytic converter in the exhaust system for promoting oxidation of exhaust gas constituents and an air supply system including an air pump and having a first branch for delivering air to the exhaust system at a location upstream and remote from the catalytic converter and a second branch for delivering air to the catalytic converter, the air control valve comprising, in combination: a valve body defining a valve chamber having an inlet connected to the air pump, a first outlet connected to the first branch, a second outlet connected to the second branch, a third outlet to the atmosphere, a first normally closed valve in the first outlet, a second normally closed valve in the second outlet and a pressure relief valve in the third outlet; an expansible chamber motor defining a first motor chamber with a restricted orifice to the atmosphere and a second motor chamber with a valved opening to the atmosphere and including a wall separating the first and second motor chambers, the wall being movable by pressure differences thereacross and including means engageable with the first and second outlet valves to open the first outlet valve when air pressure in the first chamber exceeds that in the second and to open the second outlet valve when air pressure in the second chamber exceeds that in the first; a first conduit connecting the first motor chamber with the valve chamber and including a conduit valve; a second conduit connecting the second motor chamber and the valve chamber; a first actuator responsive to the engine vacuum signal to close the conduit valve below a low vacuum signal level and open the conduit valve above the low level; and a second actuator responsive to engine vacuum to open the second chamber opening valve below a high vacuum signal level and close the second chamber opening valve above the high level.

Claim 5

An air control valve for use with an internal combustion engine having an air induction system for supplying air to the engine and generating an engine induction vacuum signal, an exhaust system for exhaust gas flow from the engine, a catalytic converter in the exhaust system for promoting oxidation of exhaust gas constituents and an air supply system including an air pump and having a first branch for delivering air to the exhaust system at a point upstream and remote from the catalytic converter and a second branch for delivering air to the catalytic converter, the air control valve comprising, in combination: a valve body defining a valve chamber having an inlet connected to the air pump, a first outlet connected to the first branch, a second outlet connected to the second branch and a third outlet openable to the atmosphere by a pressure relief valve, the valve body further including a pair of axially opposed valve seats in the valve chamber surrounding the first and second outlets; a stem projecting coaxially through the valve seats and valve chamber; first and second valve members slidably disposed on the stem; a spring compressed between the first and second valve members to normally bias the first valve member against the first valve seat to close the first outlet and bias the second valve member against the second valve seat to close the second outlet; an expansible chamber motor comprising a movable wall defining first and second motor chambers in the valve body, the movable wall being responsive to the pressure difference thereacross to assume a central position when the pressure difference is zero and move in one or the other direction from the central position when air pressure in the first motor chamber exceeds that in the second motor chamber or the air pressure in the second motor chamber exceeds that in the first motor chamber, respectively, the movable wall further having the stem attaChed thereto for co-movement, the stem having a first stop effective to engage the first valve member and open the first outlet with movement of the movable wall in the one direction from its central position and a second stop effective to engage the second valve member and open the second outlet with movement of the movable wall in the other direction from its central position; a restricted flow orifice in the valve body opening the first motor chamber to the atmosphere; a valved conduit in the valve body opening the first motor chamber to the valve chamber; a conduit in the stem opening the second motor chamber to the valve chamber; a valved opening in the valve body opening the second motor chamber to the atmosphere; a first actuator responsive to the engine induction vacuum signal to close the valved conduit below a low vacuum signal level and open the valved conduit above the low level; and a second actuator responsive to the engine induction vacuum signal to open the valved opening below a high vacuum signal level and close the valved opening above the high level.

Claim 6

An air control valve for use with an internal combustion engine having an air induction system for supplying air to the engine and generating an engine induction vacuum signal, an exhaust system for exhaust gas flow from the engine, a catalytic converter in the exhaust system for promoting oxidation of exhaust gas constituents and an air supply system including an air pump and having a first branch for delivering air to the exhaust system at a point upstream and remote from the catalytic converter and a second branch for delivering air to the catalytic converter, the air control valve comprising, in combination: a valve body defining a valve chamber having an inlet connected to the air pump, a first outlet connected to the first branch, a second outlet connected to the second branch and a third outlet openable to the atmosphere by a pressure relief valve, the valve body further including a pair of axially opposed valve seats in the valve chamber surrounding the first and second outlets; a stem projecting coaxially through the valve seats and valve chamber; first and second valve members slidably disposed on the stem; a spring compressed between the first and second valve members to normally bias the first valve member against the first valve seat to close the first outlet and bias the second valve member against the second valve seat to close the second outlet; an expansible chamber motor comprising a movable wall defining first and second motor chambers in the valve body, the movable wall being responsive to the pressure difference thereacross to assume a central position when the pressure difference is zero and move in one or the other direction from the central position when air pressure in the first motor chamber exceeds that in the second motor chamber or the air pressure in the second motor chamber exceeds that in the first motor chamber, respectively, the movable wall further having the stem attaChed thereto for co-movement, the stem having a first stop effective to engage the first valve member and open the first outlet with movement of the movable wall in the one direction from its central position and a second stop effective to engage the second valve member and open the second outlet with movement of the movable wall in the other direction from its central position; a restricted flow orifice in the valve body opening the first motor chamber to the atmosphere; a valved conduit in the valve body opening the first motor chamber to the valve chamber; a conduit in the stem opening the second motor chamber to the valve chamber; a valved opening in the valve body opening the second motor chamber to the atmosphere; a first actuator responsive to the engine induction vacuum signal to close the valved conduit below a low vacuum signal level and open the valved conduit above the low level; and a second actuator responsive to the engine induction vacuum signal to open the valved opening below a high vacuum signal level and close the valved opening above the high level.