Exhaust gas recirculation

Claim 3

Means for controlling recirculation of exhaust gases in an internal combustion engine having an induction passage for air flow to the engine, a throttle in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage extending from said exhaust passage to said induction passage downstream of said throttle, said control means comprising means defining an orifice in said recirculation passage, means defining a valve seat in said recirculation passage downstream of said orifice, a valve associated with said valve seat for controlling exhaust gas flow therethrough, and means for positioning said valve to maintain a zone of substantially constant pressure in said recirculation passage between said valve seat and said orifice, whereby exhaust gases may be recirculated from said exhaust passage through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust back pressure and thus is proportional to the rate of air flow through said induction passage.

Claim 4

Means for controlling recirculation of exhaust gases in an internal combustion engine having an induction passage for air flow to the engine, a throttle in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage extending from said exhaust passage to said induction passage downstream of said throttle, said control means comprising means defining an orifice in said recirculation passage, means defining a valve seat in said recirculation passage downstream of said orifice, a valve associated with said valve seat for controlling exhaust gas flow therethrough, and means for positioning said valve to maintain a zone of substantially constant pressure in said recirculation passage between said valve seat and said orifice, whereby exhaust gases may be recirculated from said exhaust passage through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust back pressure and thus is proportional to the rate of air flow through said induction passage.

Claim 5

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, and an exhaust passage for exhaust gas flow from the engine, said control valve assembly comprising means defining an exhaust gas recirculation passage having an inlet for receiving exhaust gases from said exhaust passage and an outlet for discharging exhaust gases to said induction passage downstream of said throttle and forming an orifice in said recirculation passage and forming a valve seat in said recirculation passage downstream of said orifice, a valve member associated with said valve seat for controlling exhaust gas flow therethrough, a pressure responsive member connected to said valve member and subjected to the pressure in the zone between said orifice and said valve seat, said pressure responsive member being responsive to an increase in pressure in said zone to displace said valve member from said valve seat, thereby permitting increased flow of exhaust gases through said valve seat, and being responsive to a decrease in pressure in said zone to displace said valve member toward said valve seat, thereby reducing flow of exhaust gases through said valve seat, whereby the pressure in said zone is maintained at a substantially constant value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 6

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, and an exhaust passage for exhaust gas flow from the engine, said control valve assembly comprising means defining an exhaust gas recirculation passage having an inlet for receiving exhaust gases from said exhaust passage and an outlet for discharging exhaust gases to said induction passage downstream of said throttle and forming an orifice in said recirculation passage and forming a valve seat in said recirculation passage downstream of said orifice, a valve member associated with said valve seat for controlling exhaust gas flow therethrough, a pressure responsive member connected to said valve member and subjected to the pressure in the zone between said orifice and said valve seat, said pressure responsive member being responsive to an increase in pressure in said zone to displace said valve member from said valve seat, thereby permitting increased flow of exhaust gases through said valve seat, and being responsive to a decrease in pressure in said zone to displace said valve member toward said valve seat, thereby reducing flow of exhaust gases through said valve seat, whereby the pressure in said zone is maintained at a substantially constant value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 7

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gAs recirculation passage having a first portion extending from said exhaust passage and a second portion extending to said induction passage downstream of said throttle, said control valve assembly comprising a valve body having an inlet for receiving exhaust gases from said first portion of said recirculation passage, an outlet for discharging exhaust gases to said second portion of said recirculation passage, valve seat means formed between said inlet and said outlet, and an orifice formed in said inlet, valve means associated with said valve seat means for controlling flow of exhaust gases therethrough, pressure responsive means connected to said valve means and responsive to the pressure in the zone between said orifice and said valve seat means to displace said valve means from said valve seat means upon an increase in pressure in said zone, thereby permitting increased flow of exhaust gases through said valve seat means, and to displace said valve means toward said valve seat means upon a decrease in pressure in said zone, thereby reducing flow of exhaust gases through said valve seat means, whereby the pressure in said zone is maintained at a substantially constant value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 8

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gAs recirculation passage having a first portion extending from said exhaust passage and a second portion extending to said induction passage downstream of said throttle, said control valve assembly comprising a valve body having an inlet for receiving exhaust gases from said first portion of said recirculation passage, an outlet for discharging exhaust gases to said second portion of said recirculation passage, valve seat means formed between said inlet and said outlet, and an orifice formed in said inlet, valve means associated with said valve seat means for controlling flow of exhaust gases therethrough, pressure responsive means connected to said valve means and responsive to the pressure in the zone between said orifice and said valve seat means to displace said valve means from said valve seat means upon an increase in pressure in said zone, thereby permitting increased flow of exhaust gases through said valve seat means, and to displace said valve means toward said valve seat means upon a decrease in pressure in said zone, thereby reducing flow of exhaust gases through said valve seat means, whereby the pressure in said zone is maintained at a substantially constant value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 9

Means for controlling recirculation of exhaust gases in an internal combustion engine having an induction passage for air flow to the engine, a throttle in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage extending from said exhaust passage to said induction passage downstream of said throttle, said control means comprising means defining a valve seat in said recirculation passage, a valve associated with said valve seat for controlling exhaust gas flow therethrough, pressure responsive means for positioning said valve, and means for subjecting said pressure responsive means to the differential between the pressure in said exhaust gas recirculation passage upstream of said valve seat and atmospheric pressure whereby upon an increase in such pressure differential said valve is displaced from said valve seat to permit increased recirculation of exhaust gases and whereby upon a decrease in such pressure differential said valve is displaced toward said valve seat to reduce recirculation of exhaust gases.

Claim 10

Means for controlling recirculation of exhaust gases in an internal combustion engine having an induction passage for air flow to the engine, a throttle in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage extending from said exhaust passage to said induction passage downstream of said throttle, said control means comprising means defining a valve seat in said recirculation passage, a valve associated with said valve seat for controlling exhaust gas flow therethrough, pressure responsive means for positioning said valve, and means for subjecting said pressure responsive means to the differential between the pressure in said exhaust gas recirculation passage upstream of said valve seat and atmospheric pressure whereby upon an increase in such pressure differential said valve is displaced from said valve seat to permit increased recirculation of exhaust gases and whereby upon a decrease in such pressure differential said valve is displaced toward said valve seat to reduce recirculation of exhaust gases.

Claim 11

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, and an exhaust passage for exhaust gas flow from the engine, said control valve assembly comprising means defining an exhaust gas recirculation passage having an inlet for receiving exhaust gases from said exhaust passage and an outlet for discharging exhaust gases to said induction passage downstream of said throttle and forming an orifice in said recirculation passage and forming a valve seat in said recirculation passage downstream of said orifice, a valve member associated with said valve seat for controlling exhaust gas flow therethrough, a pressure responsive member connected to said valve member and subjected on one side to the pressure in the zone between said orifice and said valve seat and subjected on the opposite side to atmospheric pressure, said pressure responsive member being responsive to an increase in pressure in said zone to displace said valve member from said valve seat, thereby permitting increase flow of exhaust gases through said valve seat, and being responsive to a decrease in pressure in said zone to displace said valve member toward said valve seat, thereby reducing flow of exhaust gases through said valVe seat, whereby the pressure in said zone is maintained at a substantially constant value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 12

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, and an exhaust passage for exhaust gas flow from the engine, said control valve assembly comprising means defining an exhaust gas recirculation passage having an inlet for receiving exhaust gases from said exhaust passage and an outlet for discharging exhaust gases to said induction passage downstream of said throttle and forming an orifice in said recirculation passage and forming a valve seat in said recirculation passage downstream of said orifice, a valve member associated with said valve seat for controlling exhaust gas flow therethrough, a pressure responsive member connected to said valve member and subjected on one side to the pressure in the zone between said orifice and said valve seat and subjected on the opposite side to atmospheric pressure, said pressure responsive member being responsive to an increase in pressure in said zone to displace said valve member from said valve seat, thereby permitting increase flow of exhaust gases through said valve seat, and being responsive to a decrease in pressure in said zone to displace said valve member toward said valve seat, thereby reducing flow of exhaust gases through said valVe seat, whereby the pressure in said zone is maintained at a substantially constant value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 13

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, and an exhaust passage for exhaust gas flow from the engine, said control valve assembly comprising means defining an exhaust gas recirculation passage having an inlet for receiving exhaust gases from said exhaust passage and an outlet for discharging exhaust gases to said induction passage downstream of said throttle and forming an orifice in said recirculation passage and forming a valve seat in said recirculation passage downstream of said orifice, a valve member associated with said valve seat for controlling exhaust gas flow therethrough, a pressure responsive member connected to said valve member and subjected on one side of the pressure in the zone between said orifice and said valve seat and subjected on the opposite side to atmospheric pressure, spring means biasing said valve member away from said valve seat, said pressure responsive member being responsive to an increase in pressure in said zone to displace said valve member from said valve seat under the bias of said spring means, thereby permitting increased flow of exhaust gases through said valve seat, and being responsive to a decrease in pressure in said zone to displace said valve member toward said valve seat against the bias of said spring means thereby reducing flow of exhaust gases through said valve seat, whereby the pressure in said zone is maintained at a substantially constant subatmospheric value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 14

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, and an exhaust passage for exhaust gas flow from the engine, said control valve assembly comprising means defining an exhaust gas recirculation passage having an inlet for receiving exhaust gases from said exhaust passage and an outlet for discharging exhaust gases to said induction passage downstream of said throttle and forming an orifice in said recirculation passage and forming a valve seat in said recirculation passage downstream of said orifice, a valve member associated with said valve seat for controlling exhaust gas flow therethrough, a pressure responsive member connected to said valve member and subjected on one side of the pressure in the zone between said orifice and said valve seat and subjected on the opposite side to atmospheric pressure, spring means biasing said valve member away from said valve seat, said pressure responsive member being responsive to an increase in pressure in said zone to displace said valve member from said valve seat under the bias of said spring means, thereby permitting increased flow of exhaust gases through said valve seat, and being responsive to a decrease in pressure in said zone to displace said valve member toward said valve seat against the bias of said spring means thereby reducing flow of exhaust gases through said valve seat, whereby the pressure in said zone is maintained at a substantially constant subatmospheric value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 15

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, and an exhaust passage for exhaust gas flow from the engine, said control valve assembly comprising means defining an exhaust gas recirculation passage having an inlet for receiving exhaust gases from said exhaust passage and an outlet for discharging exhaust gases to said induction passage downstream of said throttle and forming an orifice in said recirculation passage and forming a valve seat in said recirculation passage downstream of said orifice, a valve member associated with said valve seat for controlling exhaust gas flow therethrough, a pressure responsive member connected to said valve member and subjected on one side to the pressure in the zone between said orifice and said valve seat and subjected on the opposite side to atmospheric pressure, spring means biasing said valve member toward said valve seat, said pressure responsive member being responsive to an increase in pressure in said zone to displace said valve member from said valve seat against the bias of said spring means, thereby permitting increased flow of exhaust gases through said valve seat, and being responsive to a decrease in pressure in said zone to displce said valve member toward said valve seat under the bias of said spring means, thereby reducing flow of exhaust gases through said valve seat, whereby the pressure in said zone is maintained at a substantially constant superatmospheric value and exhaust gas may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 16

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, and an exhaust passage for exhaust gas flow from the engine, said control valve assembly comprising means defining an exhaust gas recirculation passage having an inlet for receiving exhaust gases from said exhaust passage and an outlet for discharging exhaust gases to said induction passage downstream of said throttle and forming an orifice in said recirculation passage and forming a valve seat in said recirculation passage downstream of said orifice, a valve member associated with said valve seat for controlling exhaust gas flow therethrough, a pressure responsive member connected to said valve member and subjected on one side to the pressure in the zone between said orifice and said valve seat and subjected on the opposite side to atmospheric pressure, spring means biasing said valve member toward said valve seat, said pressure responsive member being responsive to an increase in pressure in said zone to displace said valve member from said valve seat against the bias of said spring means, thereby permitting increased flow of exhaust gases through said valve seat, and being responsive to a decrease in pressure in said zone to displce said valve member toward said valve seat under the bias of said spring means, thereby reducing flow of exhaust gases through said valve seat, whereby the pressure in said zone is maintained at a substantially constant superatmospheric value and exhaust gas may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 17

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage having a first portion extending from said exhaust passage and a second position extending to said induction passage downstream of said throttle, said control valve assembly comprising a valve body having an inlet for receiving exhaust gases from said first portion of said recirculation passage, an outlet for discharging exhaust gases to said second portion of said recirculation passage, a pair of coaxially disposed openings having valve seats formed thereabout disposed between said inlet and said outlet, said openings each having an inlet side receiving exhaust gases from said valve body inlet and an outlet side discharging exhaust gases to said valve body outlet, said outlet sides being adjacently disposed and said inlet sides being remotely disposed one from the other, and an orifice formed in said inlet, and a pair of valve members each associated with one of said valve seats for controlling flow of exhaust gases therethrough in a manner substantially unaffected by the effect of the pressure acting on said valve members, pressure responsive means connected to said valve members and responsive to the pressure in the zone between said orifice and said valve seats to displace said valve members from said valve seats upon an increase in pressure in said zone, thereby permitting increased flow of exhaust gases through said valve seats, and to displace said valve members toward said valve seats upon a decrease in pressure in said zone, thereby reducing flow of exhaust gases through said valve seats, whereby the pressure in said zone is maintained at a substantially constant value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 18

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage having a first portion extending from said exhaust passage and a second position extending to said induction passage downstream of said throttle, said control valve assembly comprising a valve body having an inlet for receiving exhaust gases from said first portion of said recirculation passage, an outlet for discharging exhaust gases to said second portion of said recirculation passage, a pair of coaxially disposed openings having valve seats formed thereabout disposed between said inlet and said outlet, said openings each having an inlet side receiving exhaust gases from said valve body inlet and an outlet side discharging exhaust gases to said valve body outlet, said outlet sides being adjacently disposed and said inlet sides being remotely disposed one from the other, and an orifice formed in said inlet, and a pair of valve members each associated with one of said valve seats for controlling flow of exhaust gases therethrough in a manner substantially unaffected by the effect of the pressure acting on said valve members, pressure responsive means connected to said valve members and responsive to the pressure in the zone between said orifice and said valve seats to displace said valve members from said valve seats upon an increase in pressure in said zone, thereby permitting increased flow of exhaust gases through said valve seats, and to displace said valve members toward said valve seats upon a decrease in pressure in said zone, thereby reducing flow of exhaust gases through said valve seats, whereby the pressure in said zone is maintained at a substantially constant value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 19

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage having a first portion extending from said exhaust passage and a second portion extending to said induction passage downstream of said throttle, said control valve assembly comprising a valve body having an inlet for receiving exhaust gases from said first portion of said recirculation passage, an outlet for discharging exhaust gases to said second portion of said recirculation passage, a pair of coaxially disposed openings each having a valve seat formed thereabout disposed between said inlet and said outlet, one of said openings being larger than the other of said openings, and an orifice formed in said inlet, a pair of valve members associated with said valve seats for controlling flow of exhaust gases therethrough, one of said valve members being larger than the other of said valve members, said one valve member being associated with said valve seat formed about said one opening and said other valve member being associated with said valve seat formed about said other opening, and wherein said other valve member may pass through said one opening for ease of assembly, pressure responsive means connected to said valve members and responsive tO the pressure in the zone between said orifice and said valve seats to displace said valve members from said valve seats upon an increase in pressure in said zone, thereby permitting increased flow of exhaust gases through said valve seats, and to displace said valve members toward said valve seats upon a decrease in pressure in said zone, thereby reducing flow of exhaust gases through said valve seats, whereby the pressure in said zone is maintained at a substantially constant value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 20

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage having a first portion extending from said exhaust passage and a second portion extending to said induction passage downstream of said throttle, said control valve assembly comprising a valve body having an inlet for receiving exhaust gases from said first portion of said recirculation passage, an outlet for discharging exhaust gases to said second portion of said recirculation passage, a pair of coaxially disposed openings each having a valve seat formed thereabout disposed between said inlet and said outlet, one of said openings being larger than the other of said openings, and an orifice formed in said inlet, a pair of valve members associated with said valve seats for controlling flow of exhaust gases therethrough, one of said valve members being larger than the other of said valve members, said one valve member being associated with said valve seat formed about said one opening and said other valve member being associated with said valve seat formed about said other opening, and wherein said other valve member may pass through said one opening for ease of assembly, pressure responsive means connected to said valve members and responsive tO the pressure in the zone between said orifice and said valve seats to displace said valve members from said valve seats upon an increase in pressure in said zone, thereby permitting increased flow of exhaust gases through said valve seats, and to displace said valve members toward said valve seats upon a decrease in pressure in said zone, thereby reducing flow of exhaust gases through said valve seats, whereby the pressure in said zone is maintained at a substantially constant value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 21

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage having a first portion extending from said exhaust passage and a second portion extending to said induction passage downstream of said throttle, said control valve assembly comprising a valve body having an inlet for receiving exhaust gases from said first portion of said recirculation passage, an outlet for discharging exhaust gases to said second portion of said recirculation passage, valve seat means formed between said inlet and said outlet, and an orifice formed in said inlet, valve means associated with said valve seat means and cooperating with the inlet side of said valve seat means to control flow of exhaust gases therethrough, a pressure responsive member disposed parallel to and on the inlet side of said valve seat means and connected to said valve means and responsive to the pressure in the zone between said orifice and said valve seat means to displace said valve means from said valve seat means upon an increase in pressure in said zone, thereby permitting increased flow of exhaust gases through said valve seat means, and to displace said valve means toward said valve seat means upon a decrease in pressure in said zone, thereby reducing flow of exhaust gases through said valve seat means, whereby the pressure in said zone is maintained at a substantially constant value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 22

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage having a first portion extending from said exhaust passage and a second portion extending to said induction passage downstream of said throttle, said control valve assembly comprising a valve body having an inlet for receiving exhaust gases from said first portion of said recirculation passage, an outlet for discharging exhaust gases to said second portion of said recirculation passage, valve seat means formed between said inlet and said outlet, and an orifice formed in said inlet, valve means associated with said valve seat means and cooperating with the inlet side of said valve seat means to control flow of exhaust gases therethrough, a pressure responsive member disposed parallel to and on the inlet side of said valve seat means and connected to said valve means and responsive to the pressure in the zone between said orifice and said valve seat means to displace said valve means from said valve seat means upon an increase in pressure in said zone, thereby permitting increased flow of exhaust gases through said valve seat means, and to displace said valve means toward said valve seat means upon a decrease in pressure in said zone, thereby reducing flow of exhaust gases through said valve seat means, whereby the pressure in said zone is maintained at a substantially constant value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 23

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage having a first portion extending from said exhaust passage and a second portion extending to said induction passage downstream of said throttle, said control valve assembly comprising a valve body having an inlet for receiving exhaust gases from said first portion of said recirculation passage, an outlet for discharging exhaust gases to said second portion of said recirculation passage, valve seat means formed between said inlet and said outlet, and an orifice formed in said inlet, valve means associated with said valve seat means and cooperating with the inlet side of said valve seat means to control flow of exhaust gases therethrough, a pressure responsive member disposed parallel to and on the inlet side of said valve seat means and connected to said valve means are subjected on the side adjacent said valve seat means to the pressure in the zone between said orifice and said valve seat means to displace said valve meaNs from said valve seat means upon an increase in pressure in said zone, thereby permitting increased flow of exhaust gases through said valve seat means, and to displace said valve means toward said valve seat means upon a decrease in pressure in said zone, thereby reducing flow of exhaust gases through said valve seat means, whereby the pressure in said zone is maintained at a substantially constant valve and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 24

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage having a first portion extending from said exhaust passage and a second portion extending to said induction passage downstream of said throttle, said control valve assembly comprising a valve body having an inlet for receiving exhaust gases from said first portion of said recirculation passage, an outlet for discharging exhaust gases to said second portion of said recirculation passage, valve seat means formed between said inlet and said outlet, and an orifice formed in said inlet, valve means associated with said valve seat means and cooperating with the inlet side of said valve seat means to control flow of exhaust gases therethrough, a pressure responsive member disposed parallel to and on the inlet side of said valve seat means and connected to said valve means are subjected on the side adjacent said valve seat means to the pressure in the zone between said orifice and said valve seat means to displace said valve meaNs from said valve seat means upon an increase in pressure in said zone, thereby permitting increased flow of exhaust gases through said valve seat means, and to displace said valve means toward said valve seat means upon a decrease in pressure in said zone, thereby reducing flow of exhaust gases through said valve seat means, whereby the pressure in said zone is maintained at a substantially constant valve and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 25

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage having a first portion extending from said exhaust passage and a second portion extending to said induction passage downstream of said throttle, said control valve assembly comprising a valve body having an inlet for receiving exhaust gases from said first portion of said recirculation passage, an outlet for discharging exhaust gases to said second portion of said recirculation passage, valve seat means formed between said inlet and said outlet, and an orifice formed in said inlet, valve means associated with said valve seat means and cooperating with the outlet side of said valve seat means to control flow of exhaust gases therethrough, a pressure responsive member disposed parallel to and on the outlet side of said valve seat means and connected to said valve means and responsive to the pressure in the zone between said orifice and said valve seat means to displace said valve means from said valve seat means upon an increase in pressure in said zone, thereby permitting increased flow of exhaust gases through said valve seat means, and to displace said valve means toward said valve seat means upon a decrease in pressure in said zone, thereby reducing flow of exhaust gases through said valve seat means, whereby the pressure in said zone is maintained at a substantially constant value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 26

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage having a first portion extending from said exhaust passage and a second portion extending to said induction passage downstream of said throttle, said control valve assembly comprising a valve body having an inlet for receiving exhaust gases from said first portion of said recirculation passage, an outlet for discharging exhaust gases to said second portion of said recirculation passage, valve seat means formed between said inlet and said outlet, and an orifice formed in said inlet, valve means associated with said valve seat means and cooperating with the outlet side of said valve seat means to control flow of exhaust gases therethrough, a pressure responsive member disposed parallel to and on the outlet side of said valve seat means and connected to said valve means and responsive to the pressure in the zone between said orifice and said valve seat means to displace said valve means from said valve seat means upon an increase in pressure in said zone, thereby permitting increased flow of exhaust gases through said valve seat means, and to displace said valve means toward said valve seat means upon a decrease in pressure in said zone, thereby reducing flow of exhaust gases through said valve seat means, whereby the pressure in said zone is maintained at a substantially constant value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 27

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage having a first portion extending from said exhaust passage and a second portion extending to said induction passage downstream of said throttle, said control valve assembly comprising a valve body having an inlet for receiving exhaust gases from said first portion of said recirculation passage, an outlet for discharging exhaust gases to said second portion of said recirculation passage, valve seat means formed between said inlet and said outlet, and an orifice formed in said inlet, valve means associated with said valve seat means and cooperating with the inlet side of said valve seat means to control flow of exhaust gases therethrough, a pressure responsive member disposed parallel to and on the outlet side of said valve seat means and connected to said valve means and responsive to the pressure in the zone between said orifice and said valve seat means to displace said valve means from said valve seat means upon an increase in pressure in said zone, thereby permitting increased flow of exhaust Gases through said valve seat means, and to displace said valve means toward said valve seat means upon a decrease in pressure in said zone, thereby reducing flow of exhaust gases through said valve seat means, whereby the pressure in said zone is maintained at a substantially constant value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 28

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage having a first portion extending from said exhaust passage and a second portion extending to said induction passage downstream of said throttle, said control valve assembly comprising a valve body having an inlet for receiving exhaust gases from said first portion of said recirculation passage, an outlet for discharging exhaust gases to said second portion of said recirculation passage, valve seat means formed between said inlet and said outlet, and an orifice formed in said inlet, valve means associated with said valve seat means and cooperating with the inlet side of said valve seat means to control flow of exhaust gases therethrough, a pressure responsive member disposed parallel to and on the outlet side of said valve seat means and connected to said valve means and responsive to the pressure in the zone between said orifice and said valve seat means to displace said valve means from said valve seat means upon an increase in pressure in said zone, thereby permitting increased flow of exhaust Gases through said valve seat means, and to displace said valve means toward said valve seat means upon a decrease in pressure in said zone, thereby reducing flow of exhaust gases through said valve seat means, whereby the pressure in said zone is maintained at a substantially constant value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 29

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow there-through, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage having a first portion extending from said exhaust passage and a second portion extending to said induction passage downstream of said throttle, said control valve assembly comprising a valve body having an inlet for receiving exhaust gases from said first portion of said recirculation passage, an outlet for discharging exhaust gases to said second portion of said recirculation passage, valve seat means formed between said inlet and said outlet, and an orifice formed in said inlet, valve means associated with said valve seat means and cooperating with the inlet side of said valve seat means to control flow of exhaust gases therethrough, a pressure responsive member disposed parallel to and on the outlet side of said valve seat means and connected to said valve means and subjected on the side remote from said valve seat means to the pressure in the zone between said orifice and said valve seat means to displace said valve means from said valve seat means upon an increase in pressure in said zone, thereby permitting increased flow of exhaust gases through said valve seat means, and to displace said valve means toward said valve seat means upon a decrease in pressure in said zone, thereby reducing flow of exhaust gases through said valve seat means, whereby the pressure in said zone is maintained at a substantially constant value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 30

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow there-through, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage having a first portion extending from said exhaust passage and a second portion extending to said induction passage downstream of said throttle, said control valve assembly comprising a valve body having an inlet for receiving exhaust gases from said first portion of said recirculation passage, an outlet for discharging exhaust gases to said second portion of said recirculation passage, valve seat means formed between said inlet and said outlet, and an orifice formed in said inlet, valve means associated with said valve seat means and cooperating with the inlet side of said valve seat means to control flow of exhaust gases therethrough, a pressure responsive member disposed parallel to and on the outlet side of said valve seat means and connected to said valve means and subjected on the side remote from said valve seat means to the pressure in the zone between said orifice and said valve seat means to displace said valve means from said valve seat means upon an increase in pressure in said zone, thereby permitting increased flow of exhaust gases through said valve seat means, and to displace said valve means toward said valve seat means upon a decrease in pressure in said zone, thereby reducing flow of exhaust gases through said valve seat means, whereby the pressure in said zone is maintained at a substantially constant value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 31

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage having a first portion extending from said exhaust passage and a second portion extending to said induction passage downstream of said throttle, said control valve assembly comprising a valve body having an inlet for receiving exhaust gases from said first portion of said recirculation passage, an outlet for discharging exhaust gases to said second portion of said recirculation passage, valve seat means formed between said inlet and said outlet, and an orifice formed in said inlet, valve means associated with said valve seat means for controlling flow of exhaust gases therethrough, a pressure responsive member connected to said valve means and having an effective area approximately equal to the area of said valve means exposed to the pressure in said outlet and responsive to the pressure in said outlet to offset the force exerted on said valve means by the pressure in said outlet, a second pressure responsive member connected to said valve means and responsive to the pressure in the zone between said orifice and said valve seat means to displace said valve means from Said valve seat means upon an increase in pressure in said zone, thereby permitting increased flow of exhaust gases through said valve seat means, and to displace said valve means toward said valve seat means upon a decrease in pressure in said zone, thereby reducing flow of exhaust gases through said valve seat means, whereby the pressure in said zone is maintained at a substantially constant value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 32

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage having a first portion extending from said exhaust passage and a second portion extending to said induction passage downstream of said throttle, said control valve assembly comprising a valve body having an inlet for receiving exhaust gases from said first portion of said recirculation passage, an outlet for discharging exhaust gases to said second portion of said recirculation passage, valve seat means formed between said inlet and said outlet, and an orifice formed in said inlet, valve means associated with said valve seat means for controlling flow of exhaust gases therethrough, a pressure responsive member connected to said valve means and having an effective area approximately equal to the area of said valve means exposed to the pressure in said outlet and responsive to the pressure in said outlet to offset the force exerted on said valve means by the pressure in said outlet, a second pressure responsive member connected to said valve means and responsive to the pressure in the zone between said orifice and said valve seat means to displace said valve means from Said valve seat means upon an increase in pressure in said zone, thereby permitting increased flow of exhaust gases through said valve seat means, and to displace said valve means toward said valve seat means upon a decrease in pressure in said zone, thereby reducing flow of exhaust gases through said valve seat means, whereby the pressure in said zone is maintained at a substantially constant value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 33

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage having a first portion extending from said exhaust passage and a second portion extending to said induction passage downstream of said throttle, said control valve assembly comprising a valve body having an inlet for receiving exhaust gases from said first portion of said recirculation passage, an outlet for discharging exhaust gases to said second portion of said recirculation passage, valve seat means formed between siad inlet and said outlet, and an orifice formed in said inlet, valve means associated with said valve seat means and cooperating with the inlet side of said valve seat means to control flow of exhaust gases therethrough, a pair of parallel pressure responsive members disposed on the inlet side of said valve seat means and connected to said valve means, one of said pressure responsive members having an effective area approximately equal to the area of said valve means exposed to the pressure in said outlet, the sides of said pressure responsive members adjacent one another being subjected to atmospheric pressure, the opposite side of said one member being subjected to the pressure in said outlet to offset the force exerted on said valve means by the pressure in said outlet, the opposite side of the other pressure responsive member being subjected to the pressure in the zone between said orifice and said valve seat means to displace said valve means from said valve seat means upon an increase in pressure in said zone, thereby permitting increased flow of exhaust gases through said valve seat means, and to displace said valve means toward said valve seat means upon a decrease in pressure in said zone, thereby reducing flow of exhaust gases through said valve seat means, whereby the pressure in said zone is maintained at a substantially constant value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 34

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage having a first portion extending from said exhaust passage and a second portion extending to said induction passage downstream of said throttle, said control valve assembly comprising a valve body having an inlet for receiving exhaust gases from said first portion of said recirculation passage, an outlet for discharging exhaust gases to said second portion of said recirculation passage, valve seat means formed between siad inlet and said outlet, and an orifice formed in said inlet, valve means associated with said valve seat means and cooperating with the inlet side of said valve seat means to control flow of exhaust gases therethrough, a pair of parallel pressure responsive members disposed on the inlet side of said valve seat means and connected to said valve means, one of said pressure responsive members having an effective area approximately equal to the area of said valve means exposed to the pressure in said outlet, the sides of said pressure responsive members adjacent one another being subjected to atmospheric pressure, the opposite side of said one member being subjected to the pressure in said outlet to offset the force exerted on said valve means by the pressure in said outlet, the opposite side of the other pressure responsive member being subjected to the pressure in the zone between said orifice and said valve seat means to displace said valve means from said valve seat means upon an increase in pressure in said zone, thereby permitting increased flow of exhaust gases through said valve seat means, and to displace said valve means toward said valve seat means upon a decrease in pressure in said zone, thereby reducing flow of exhaust gases through said valve seat means, whereby the pressure in said zone is maintained at a substantially constant value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 35

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage having a first portion extending from said exhaust passage and a second portion extending to said induction passage downstream of said throttle, said control valve assembly comprising a valve body having an inlet for receiving exhaust gases from said first portion of said recirculation passage, an outlet for discharging exhaust gases to said second portion of said recirculation passage, valve seat means formed between said inlet and said outlet, and an orifice formed in said inlet, valve means associated with said valVe seat means and cooperating with the inlet side of said valve seat means to control flow of exhaust gases therethrough, a pair of parallel pressure responsive diaphragms disposed on the inlet side of said valve seat means, a hollow stem connecting said diaphragms to said valve means, one of said diaphragms having an effective area approximately equal to the area of said valve means exposed to the pressure in said outlet, the sides of said diaphragms adjacent one another being subjected to atmospheric pressure, the opposite side of said one diaphragm being subjected through said hollow stem to the pressure in said outlet to offset the force exerted on said valve means by the pressure in said outlet, the opposite side of the other diaphragm being subjected to the pressure in the zone between said orifice and said valve seat means to displace said valve means from said valve seat means upon an increase in pressure in said zone, thereby permitting increased flow of exhaust gases through said valve seat means, and to displace said valve means toward said valve seat means upon a decrease in pressure in said zone, thereby reducing flow of exhaust gases through said valve seat means, whereby the pressure in said zone is maintained at a substantially constant value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 36

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage having a first portion extending from said exhaust passage and a second portion extending to said induction passage downstream of said throttle, said control valve assembly comprising a valve body having an inlet for receiving exhaust gases from said first portion of said recirculation passage, an outlet for discharging exhaust gases to said second portion of said recirculation passage, valve seat means formed between said inlet and said outlet, and an orifice formed in said inlet, valve means associated with said valVe seat means and cooperating with the inlet side of said valve seat means to control flow of exhaust gases therethrough, a pair of parallel pressure responsive diaphragms disposed on the inlet side of said valve seat means, a hollow stem connecting said diaphragms to said valve means, one of said diaphragms having an effective area approximately equal to the area of said valve means exposed to the pressure in said outlet, the sides of said diaphragms adjacent one another being subjected to atmospheric pressure, the opposite side of said one diaphragm being subjected through said hollow stem to the pressure in said outlet to offset the force exerted on said valve means by the pressure in said outlet, the opposite side of the other diaphragm being subjected to the pressure in the zone between said orifice and said valve seat means to displace said valve means from said valve seat means upon an increase in pressure in said zone, thereby permitting increased flow of exhaust gases through said valve seat means, and to displace said valve means toward said valve seat means upon a decrease in pressure in said zone, thereby reducing flow of exhaust gases through said valve seat means, whereby the pressure in said zone is maintained at a substantially constant value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 37

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage having a first portion extending from said exhaust passage and a second portion extending to said induction passage downstream of said throttle, said control valve assembly comprising a valve body having an inlet for receiving exhaust gases from said first portion of said recirculation passage, an outlet for discharging exhaust gases to said second portion of said recirculation passage, valve seat means formed between said inlet and said outlet, and an orifice formed in said inlet, valve means associated with said valve seat means and cooperating with the inlet side of said valve seat means to control flow of exhaust gases therethrough, a pair of parallel pressure responsive members disposed on the outlet side of said valve seat means and connected to said valve means, one of said pressure responsive members having an effective area approximately equal to the area of said valve means exposed to the pressure in said outlet and having the side thereof adjacent said valve seat means subjected to the pressure in said outlet to offset the force exerted on said valve means by the pressure in said outlet, the side of said other pressure responsive member remote from said valve seat means being subjected to the pressure in the zone between said orifice and said valve seat means to displace said valve means from said valve seat means upon an increase in pressure in said zone, thereby permitting increased flow of exhaust gases through said valve seat means, and to displace said valve means toward said valve seat means upon a decrease in pressure in said zone, thereby reducing flow of exhaust gases through said valve seat means, whereby the pressure in said zone is maintained at a substantially constant value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 38

An exhaust gas recirculation control valve assembly for use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage having a first portion extending from said exhaust passage and a second portion extending to said induction passage downstream of said throttle, said control valve assembly comprising a valve body having an inlet for receiving exhaust gases from said first portion of said recirculation passage, an outlet for discharging exhaust gases to said second portion of said recirculation passage, valve seat means formed between said inlet and said outlet, and an orifice formed in said inlet, valve means associated with said valve seat means and cooperating with the inlet side of said valve seat means to control flow of exhaust gases therethrough, a pair of parallel pressure responsive members disposed on the outlet side of said valve seat means and connected to said valve means, one of said pressure responsive members having an effective area approximately equal to the area of said valve means exposed to the pressure in said outlet and having the side thereof adjacent said valve seat means subjected to the pressure in said outlet to offset the force exerted on said valve means by the pressure in said outlet, the side of said other pressure responsive member remote from said valve seat means being subjected to the pressure in the zone between said orifice and said valve seat means to displace said valve means from said valve seat means upon an increase in pressure in said zone, thereby permitting increased flow of exhaust gases through said valve seat means, and to displace said valve means toward said valve seat means upon a decrease in pressure in said zone, thereby reducing flow of exhaust gases through said valve seat means, whereby the pressure in said zone is maintained at a substantially constant value and exhaust gases may be recirculated through an orifice into a zone of substantially constant pressure to thereby provide recirculation of exhaust gases at a rate which varies in accordance with exhaust gas pressure in said exhaust passage and thus is proportional to the rate of air flow through said induction passage.

Claim 39

An exhaust gas recirculation control valve assembly For use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage having a first portion extending from said exhaust passage and a second portion extending to said induction passage downstream of said throttle, said control valve assembly comprising a valve body having an inlet for receiving exhaust gases from said first portion of said recirculation passage, an outlet for discharging exhaust gases to said second portion of said recirculation passage, valve seat means formed between said inlet and said outlet, and an orifice formed in said inlet, valve means associated with said valve seat means for controlling flow of exhaust gases therethrough, and control means for positioning said valve means to maintain a substantially constant pressure in the zone between said orifice and said valve seat means, said control means including spring means biasing said valve means toward engagement with said valve seat means, a pressure responsive member connected to said valve means, means defining a vacuum orifice through which said member is subjected to the pressure in said induction passage downstream of said throttle, means defining an air bleed orifice through which said member is subjected to atmospheric air, a bleed valve associated with said vacuum orifice for controlling admission of vacuum therethrough to vary the control pressure created by induction passage vacuum received through said vacuum orifice and atmospheric air received through said air bleed orifice, pressure responsive means connected to said bleed valve and subjected to the pressure in said zone whereby upon an increase in pressure in said zone said pressure responsive means displaces said bleed valve to increase admission of vacuum to said passage means through said vacuum orifice and thereby decreases said control pressure to thereby cause said pressure responsive member to overcome the bias of said spring means and displace said valve means from said valve seat means and increase recirculation of exhaust gases, and second spring means biasing said bleed valve to permit decreased admission of vacuum to said passage means through said vacuum orifice whereby upon a decrease in pressure in said zone said second spring means displaces said bleed valve to decrease admission of air to said passage means through said vacuum orifice and thereby increases said control pressure to thereby permit said first spring means to displace said valve means toward said valve seat means and decrease recirculation of exhaust gases.

Claim 40

An exhaust gas recirculation control valve assembly For use on an internal combustion engine having an induction passage for air flow to the engine, a throttle disposed in said induction passage for controlling air flow therethrough, an exhaust passage for exhaust gas flow from the engine, and an exhaust gas recirculation passage having a first portion extending from said exhaust passage and a second portion extending to said induction passage downstream of said throttle, said control valve assembly comprising a valve body having an inlet for receiving exhaust gases from said first portion of said recirculation passage, an outlet for discharging exhaust gases to said second portion of said recirculation passage, valve seat means formed between said inlet and said outlet, and an orifice formed in said inlet, valve means associated with said valve seat means for controlling flow of exhaust gases therethrough, and control means for positioning said valve means to maintain a substantially constant pressure in the zone between said orifice and said valve seat means, said control means including spring means biasing said valve means toward engagement with said valve seat means, a pressure responsive member connected to said valve means, means defining a vacuum orifice through which said member is subjected to the pressure in said induction passage downstream of said throttle, means defining an air bleed orifice through which said member is subjected to atmospheric air, a bleed valve associated with said vacuum orifice for controlling admission of vacuum therethrough to vary the control pressure created by induction passage vacuum received through said vacuum orifice and atmospheric air received through said air bleed orifice, pressure responsive means connected to said bleed valve and subjected to the pressure in said zone whereby upon an increase in pressure in said zone said pressure responsive means displaces said bleed valve to increase admission of vacuum to said passage means through said vacuum orifice and thereby decreases said control pressure to thereby cause said pressure responsive member to overcome the bias of said spring means and displace said valve means from said valve seat means and increase recirculation of exhaust gases, and second spring means biasing said bleed valve to permit decreased admission of vacuum to said passage means through said vacuum orifice whereby upon a decrease in pressure in said zone said second spring means displaces said bleed valve to decrease admission of air to said passage means through said vacuum orifice and thereby increases said control pressure to thereby permit said first spring means to displace said valve means toward said valve seat means and decrease recirculation of exhaust gases.