Recirculating exhaust gas load initiated control (relic)

Claim 2

An exhaust gas recirculating system in an internal combustion engine having intake and exhaust manifolds, a carburetor induction passage, a throttle valve controlling flow through the passage, the system comprising, a duct connecting the exhaust gases to the engine intake manifold, an exhaust gas recirculation (EGR) valve normally closing the duct to prevent recirculation and movable to an open position by a signal vacuum connected thereto, the induction passage containing an exhaust gas recirculating (EGR) port located relative to the throttle valve so as to be traversed by the throttle valve edge during opening throttle valve movements so as to be at essentially atmospheric pressure at closed throttle positions with decreases in pressure level in proportion to the progressive opening of the throttle valve upon exposure of the port to manifold vacuum until EGR port vacuum reaches the level of manifold vacuum, conduit means operatively connecting EGR port signal vacuum to the valve to move the same, a vacuum regulator in the conduit means for regulating the EGR signal vacuum level including a source of air at ambient or atmospheric pressure connected to the regulator for variably bleeding the EGR signal vacuum to a regulated level, and switch means for shutting off or permitting the flow of air to the regulator to terminate or permit the regulating function of the regulator.

Claim 3

An exhaust gas recirculating system in an internal combustion engine having intake and exhaust manifolds and a carburetor induction passage having a throttle valve controlling flow through the passage, the system comprising, a duct connecting the exhaust gases to the engine intake manifold, an exhaust gas recirculation (EGR) valve normally closing the duct to prevent recirculation and movable to an open position by a signal vacuum connected thereto, and modified manifold vacuum responsive means operable to provide a signal vacuum to the valve that varies from one pressure level at closed or nearly closed throttle positions to manifold vacuum levels near wide open throttle positions in response to movement of the throttle valve and changes in manifold vacuum to provide an EGR flow rate that varies essentially in proportion to the load during part load operation, the induction passage containing an EGR port located relative to the throttle valve so as to be traversed by the edge of the throttle valve upon opening movements of the throttle valve so as to be at essentially atmospheric pressure at closed throttle positions with decreases in pressure level in proportion to the progressive opening of the throttle valve until EGR port vacuum reaches the level of manifold vacuum, conduit means operatively connecting the EGR port signal vacuum to the valve to move the same, the vacuum responsive means including a vacuum regulator to which air at ambient or atmospheric pressure is connected by second conduit means for at times bleeding the EGR vacuum level, including an air bleed valve means in the second conduit means acted upon by manifold vacuum for movement above a predetermined manifold vacuum force level to supply air to the regulator to regulate at times the EGR signal vacuum level acting on the EGR valve.

Claim 4

An exhaust gas recirculating system in an internal combustion engine having intake and exhaust manifolds and a carburetor induction passage having a throttle valve controlling flow through the passage, the system comprising, a duct connecting the exhaust gases to the engine intake manifold, an exhaust gas recirculation (EGR) valve normally closing the duct to prevent recirculation and movable to an open position by a signal vacuum connected thereto, and modified manifold vacuum responsive means operable to provide a signal vacuum to the valve that varies from one pressure level at closed or nearly closed throttle positions to manifold vacuum levels near wide open throttle positions in response to movement of the throttle valve and changes in manifold vacuum to provide an EGR flow rate that varies essentially in proportion to the load during part load operation, the induction passage containing an EGR port located relative to the throttle valve so as to be traversed by the edge of the throttle valve upon opening movements of the throttle valve so as to be at essentially atmospheric pressure at closed throttle positions with decreases in pressure level in proportion to the progressive opening of the throttle valve until EGR port vacuum reaches the level of manifold vacuum, conduit means operatively connecting the EGR port signal vacuum to the valve to move the same, the vacuum responsive means including a vacuum regulator to which air at ambient or atmospheric pressure is connected by second conduit means for at times bleeding the EGR vacuum level, including an air bleed valve means in the second conduit means acted upon by manifold vacuum for movement above a predetermined manifold vacuum force level to supply air to the regulator to regulate at times the EGR signal vacuum level acting on the EGR valve.

Claim 5

A system as in claim 1, the switch means being moved by manifold vacuum above a predetermined level applied thereto to a position permitting flow of air to The regulator.

Claim 6

A system as in claim 1, the regulator including an atmospheric air passage, a flexible diaphragm type vacuum valve having spring means biasing the diaphragm against the air passage closing the same, means applying EGR vacuum to the diaphragm to move the vacuum valve to open the air passage and bleed down the EGR vacuum, the switch means including a second flexible diaphragm valve, other means supplying air to the air passage, second spring means biasing the second diaphragm valve to a position blocking the other means, the second diaphragm valve being responsive to manifold vacuum above the force of the second spring means to move the second diaphragm valve to open the other means and permit airflow to the air passage for control by EGR vacuum to regulate EGR signal vacuum.

Claim 7

A system as in claim 1, the regulator including an air passage having an inlet and outlet, a first valve that is spring movable to a first position against the air outlet blocking the same and blocking EGR signal vacuum flow from one side of the valve to the other, the first valve being responsive to EGR signal vacuum applied to the one side of the first valve to move the first valve to a second position unblocking the air outlet and permitting flow of air to the one side to decay the EGR signal vacuum, a second valve spring movable against the air inlet to block the same and movable by a predetermined level of manifold vacuum applied thereto to a second position opening the inlet to permit flow of air to the outlet, whereby EGR signal vacuum level to the EGR valve is regulated as a function of manifold vacuum above the predetermined level effecting the decay of EGR port vacuum to vary essentially proportional to load at part throttle operations.

Claim 8

A system as in claim 1, the vacuum regulator including a first flexible diaphragm exposed to a chamber pressure on one side and EGR port vacuum on the other side, a second flexible diaphragm exposed to manifold vacuum on one side and to a source of air on the other side, the diaphragms both being spring seated to block the flow of air to the chamber past the first and second diaphragms to bleed the EGR port vacuum, movement of the second diaphragm to an unseated position by manifold vacuum above a predetermined level and the first diaphragm by EGR port vacuum above a predetermined level regulating the EGR port vacuum by bleeddown by the air to vary the EGR flow in proportion to load during accelerations, the unseating of the first diaphragm by EGR port vacuum to the EGR valve.