Pressure transducer and exhaust gas recirculation control valve using same

Claim 2

For use on 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, and an exhaust passaage for exhaust gas flow from the engine, a pressure transducer for converting the variable pressure in said exhaust passage to a variable vacuum signal comprising a reciprocable pressure responsive diaphragm, a first housing member secured on one side of said diaphragm to form an exhaust pressure chamber therebetween, a second housing member secured on the other side of said diaphragm to form an atmospheric pressure chamber therebetween, openings for subjecting said exhaust pressure chamber to the pressure in said exhaust passage and for subjecting said atmospheric pressure chamber to atmospheric pressure, a cover enclosing said other side of said diaphragm and said second housing member and defining a region outside said atmospheric pressure chamber adapted to be subjected to the vacuum in said induction passage downstream of said throttle, said second housing member having an orifice opening from said atmospheric pressure chamber to said region, said diaphragm having a valve member reciprocable therewith, said valve member having a base portion and a tip portion and being associated with said orifice for controlling air flow from said atmospheric pressure chamber into said region to thereby vary the pressure in said region in accordance with variations in the exhaust passage pressure, and which further comprises an orifice member surrounding said orifice, said orifice member having a resilient lip receiving said tip portion of said valve member and a seating rim receiving said base portion of said valve member after said tip portion has engaged said resilient lip whereby said valve member may seal against said orifice member to prevent air flow into said region without causing said tip portion to stick in said orifice.

Claim 3

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 saaid 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 valve seat formed between said inlet and said outlet, and an orifice formed in said inlet and defining a control pressure zone between said orifice and said valve seat, a valve pintle associated with said valve seat for controlling flow of exhaust gases therethrough, and control means for positioning said valve pintle to maintain a substantially constant pressure in said control pressure zone, said control means including spring means biasing said valve pintle toward engagement with said valve seat, a pressure responsive member connected to said valve pintle, means defining a vacuum orifice through which said member may be 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 bleed orifice for controlling admission of air therethrough to vary the controlled 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 decrease admission of air through said bleed orifice and thereby decreases said controlled 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 increased admission of air through said bleed orifice whereby upon a decrease in pressure in said zone said second spring means displaces said bleed valve to increase admission of air through said bleed orifice and thereby increases said controlled pressure to thereby permit said first spring means to displace said valve means toward said valve seat means and decrease recirculation of exhaust gases, said bleed valve having a base portion and a tip portion, and which further comprises an orifice member surrounding said air bleed orifice, said orifice member having a resilient lip receiving said tip portion of said bleed valve, and a seating rim receiving said base portion of said bleed valve after said tip portion has engaged said resilient lip.

Claim 4

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 saaid 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 valve seat formed between said inlet and said outlet, and an orifice formed in said inlet and defining a control pressure zone between said orifice and said valve seat, a valve pintle associated with said valve seat for controlling flow of exhaust gases therethrough, and control means for positioning said valve pintle to maintain a substantially constant pressure in said control pressure zone, said control means including spring means biasing said valve pintle toward engagement with said valve seat, a pressure responsive member connected to said valve pintle, means defining a vacuum orifice through which said member may be 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 bleed orifice for controlling admission of air therethrough to vary the controlled 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 decrease admission of air through said bleed orifice and thereby decreases said controlled 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 increased admission of air through said bleed orifice whereby upon a decrease in pressure in said zone said second spring means displaces said bleed valve to increase admission of air through said bleed orifice and thereby increases said controlled pressure to thereby permit said first spring means to displace said valve means toward said valve seat means and decrease recirculation of exhaust gases, said bleed valve having a base portion and a tip portion, and which further comprises an orifice member surrounding said air bleed orifice, said orifice member having a resilient lip receiving said tip portion of said bleed valve, and a seating rim receiving said base portion of said bleed valve after said tip portion has engaged said resilient lip.

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, 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 valve seat formed between said inlet and said outlet, and an orifice formed in said inlet and defining a control pressure zone between said orifice and said valve seat, a valve pintle associated with said valve seat for controlling flow of exhaust gases therethrough, and control means for positioning said valve pintle to maintain a substantially constant pressure in said control pressure zone, said control means including spring means biasing said valve pintle toward engagement with said valve seat, a hollow valve stem connected to said valve pintle and extending outwardly of said valve body, a pressure responsive assembly having a first diaphragm backing member secured to said valve stem, a diaphragm having a flexible inner portion defining a control pressure chamber with said backing member, said diaphragm further having a flexible annular outer portion extending radially outwardly from said backing member, and a second diaphragm backing member defining an atmospheric pressure chamber with said inner portion of said diaphragm, a cover member defining a vacuum chamber with said outer portion of said diaphragm and said second backing member, said cover member having means for connecting said vacuum chamber to said induction passage downstream of said throttle, said inner portion of said diaphragm and said backing members having openings for admitting air to said atmospheric pressure chamber, said second backing member having an air bleed orifice for admitting air from said atmospheric pressure chamber to said vacuum chamber, a bleed valve connected to said inner portion of said diaphragm and Associated with said air bleed orifice for controlling admission of air to said vacuum chamber, said hollow stem defining a passage connecting said exhaust pressure chamber to said zone, whereby upon an increase in pressure in said zone said inner portion of said diaphragm displaces said bleed valve to decrease admission of air to said vacuum chamber through said bleed orifice and thereby decreases the pressure in said vacuum chamber to thereby cause said pressure responsive member to overcome the bias of said spring means and displace said valve pintle from said valve seat and increase recirculation of exhaust gases, and second spring means biasing said bleed valve to permit increased admission of air to said vacuum chamber through said bleed orifice whereby upon a decrease in pressure in said zone said second spring means displaces said bleed valve to increase admission of air to said vacuum chamber through said bleed orifice and thereby increases the pressure in said vacuum chamber to thereby permit said first spring means to displace said valve pintle toward said valve seat and decrease recirculation of exhaust gases, said bleed valve having a base portion and a tip portion, and which further comprises an orifice member surrounding said air bleed orifice, said orifice member having a resilient lip receiving said tip portion of said bleed valve, and a seating rim receiving said base portion of said bleed valve after said tip portion has engaged said resilient lip.

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, 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 valve seat formed between said inlet and said outlet, and an orifice formed in said inlet and defining a control pressure zone between said orifice and said valve seat, a valve pintle associated with said valve seat for controlling flow of exhaust gases therethrough, and control means for positioning said valve pintle to maintain a substantially constant pressure in said control pressure zone, said control means including spring means biasing said valve pintle toward engagement with said valve seat, a hollow valve stem connected to said valve pintle and extending outwardly of said valve body, a pressure responsive assembly having a first diaphragm backing member secured to said valve stem, a diaphragm having a flexible inner portion defining a control pressure chamber with said backing member, said diaphragm further having a flexible annular outer portion extending radially outwardly from said backing member, and a second diaphragm backing member defining an atmospheric pressure chamber with said inner portion of said diaphragm, a cover member defining a vacuum chamber with said outer portion of said diaphragm and said second backing member, said cover member having means for connecting said vacuum chamber to said induction passage downstream of said throttle, said inner portion of said diaphragm and said backing members having openings for admitting air to said atmospheric pressure chamber, said second backing member having an air bleed orifice for admitting air from said atmospheric pressure chamber to said vacuum chamber, a bleed valve connected to said inner portion of said diaphragm and Associated with said air bleed orifice for controlling admission of air to said vacuum chamber, said hollow stem defining a passage connecting said exhaust pressure chamber to said zone, whereby upon an increase in pressure in said zone said inner portion of said diaphragm displaces said bleed valve to decrease admission of air to said vacuum chamber through said bleed orifice and thereby decreases the pressure in said vacuum chamber to thereby cause said pressure responsive member to overcome the bias of said spring means and displace said valve pintle from said valve seat and increase recirculation of exhaust gases, and second spring means biasing said bleed valve to permit increased admission of air to said vacuum chamber through said bleed orifice whereby upon a decrease in pressure in said zone said second spring means displaces said bleed valve to increase admission of air to said vacuum chamber through said bleed orifice and thereby increases the pressure in said vacuum chamber to thereby permit said first spring means to displace said valve pintle toward said valve seat and decrease recirculation of exhaust gases, said bleed valve having a base portion and a tip portion, and which further comprises an orifice member surrounding said air bleed orifice, said orifice member having a resilient lip receiving said tip portion of said bleed valve, and a seating rim receiving said base portion of said bleed valve after said tip portion has engaged said resilient lip.

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, a valve seat formed between said inlet and said outlet, and an orifice formed in said inlet and defining a control pressure zone between said orifice and said valve seat, a valve pintle associated with said valve seat for controlling flow of exhaust gases therethrough, and control means for positioning said valve pintle to maintain a substantially constant pressure in said control pressure zone, said control means including spring means biasing said valve pintle toward engagement with said valve seat, a hollow valve stem connected to said valve pintle and extending outwardly of said valve body, a pressure responsive assembly having a first diaphragm backing member secured to said valve stem, a diaphragm having a flexible inner portion defining a control pressure chamber with said backing member, said diaphragm further having a flexible annular outer portion extending radially outwardly from said backing member, and a second diaphragm backing member defining an atmospheric pressure chamber with said inner portion of said diaphragm, a cover member defining a vacuum chamber with said outer portion of said diaphragm and said second backing member, said cover member having means for connecting said vacuum chamber to said induction passage downstream of said throttle, said inner portion of said diaphragm and said backing members havine openings for admitting air to said atmospheric pressure chamber, said second backing member having an air bleed orifice for admitting air from said atmospheric pressure chamber to said vacuum chamber, a bleed valve connected to said inner portion of said diaphragm and associated with said air bleed orifice for controlling admission of air to said vacuum chamber, said hollow stem defining a passage connecting said exhaust pressure chamber to said zone, whereby upon an increase in Pressure in said zone said inner portion of said diaphragm displaces said bleed valve to decrease admission of air to said vacuum chamber through said bleed orifice and thereby decreases the pressure in said vacuum chamber to thereby cause said pressure responsive member to overcome the bias of said spring means and displace said valve pintle from said valve seat and increase recirculation of exhaust gases, and second spring means biasing said bleed valve to permit increased admission of air to said vacuum chamber through said bleed orifice whereby upon a decrease in pressure in said zone said second spring means displaces said bleed valve to increase admission of air to said vacuum chamber through said bleed orifice and thereby increases the pressure in said vacuum chamber to thereby permit said first spring means to displace said valve pintle toward said valve seat and decrease recirculation of exhaust gases, wherein said first diaphragm backing member has a downwardly concave annular channel to which said openings extend and at least one of said diaphragm backing members has a plurality of recesses opening from said channel, and which further comprises an upwardly concave annular paper filter element disposed in said channel for preventing entrance of dirt through said openings to said atmospheric pressure chamber, and clip means secured to said filter element and received in said recesses for retaining said filter element in said channel.

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, a valve seat formed between said inlet and said outlet, and an orifice formed in said inlet and defining a control pressure zone between said orifice and said valve seat, a valve pintle associated with said valve seat for controlling flow of exhaust gases therethrough, and control means for positioning said valve pintle to maintain a substantially constant pressure in said control pressure zone, said control means including spring means biasing said valve pintle toward engagement with said valve seat, a hollow valve stem connected to said valve pintle and extending outwardly of said valve body, a pressure responsive assembly having a first diaphragm backing member secured to said valve stem, a diaphragm having a flexible inner portion defining a control pressure chamber with said backing member, said diaphragm further having a flexible annular outer portion extending radially outwardly from said backing member, and a second diaphragm backing member defining an atmospheric pressure chamber with said inner portion of said diaphragm, a cover member defining a vacuum chamber with said outer portion of said diaphragm and said second backing member, said cover member having means for connecting said vacuum chamber to said induction passage downstream of said throttle, said inner portion of said diaphragm and said backing members havine openings for admitting air to said atmospheric pressure chamber, said second backing member having an air bleed orifice for admitting air from said atmospheric pressure chamber to said vacuum chamber, a bleed valve connected to said inner portion of said diaphragm and associated with said air bleed orifice for controlling admission of air to said vacuum chamber, said hollow stem defining a passage connecting said exhaust pressure chamber to said zone, whereby upon an increase in Pressure in said zone said inner portion of said diaphragm displaces said bleed valve to decrease admission of air to said vacuum chamber through said bleed orifice and thereby decreases the pressure in said vacuum chamber to thereby cause said pressure responsive member to overcome the bias of said spring means and displace said valve pintle from said valve seat and increase recirculation of exhaust gases, and second spring means biasing said bleed valve to permit increased admission of air to said vacuum chamber through said bleed orifice whereby upon a decrease in pressure in said zone said second spring means displaces said bleed valve to increase admission of air to said vacuum chamber through said bleed orifice and thereby increases the pressure in said vacuum chamber to thereby permit said first spring means to displace said valve pintle toward said valve seat and decrease recirculation of exhaust gases, wherein said first diaphragm backing member has a downwardly concave annular channel to which said openings extend and at least one of said diaphragm backing members has a plurality of recesses opening from said channel, and which further comprises an upwardly concave annular paper filter element disposed in said channel for preventing entrance of dirt through said openings to said atmospheric pressure chamber, and clip means secured to said filter element and received in said recesses for retaining said filter element in said channel.

Claim 9

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 valve seat formed between said inlet and said outlet, and an orifice formed in said inlet and defining a control pressure zone between said orifice and said valve seat, a valve pintle associated with said valve seat for controlling flow of exhaust gases therethrough, and control means for positioning said valve pintle to maintain a substantially constant pressure in said control pressure zone, said control means including spring means biasing said valve pintle toward engagement with said valve seat, a hollow valve stem connected to said valve pintle and extending outwardly of said valve body, a pressure responsive assembly having a first diaphragm backing member secured to said valve stem, a diaphragm having a flexible inner portion defining a control pressure chamber with said backing member, said diaphragm further having a flexible annular outer portion extending radially outwardly from said backing member, and a second diaphragm backing member defining an atmospheric pressure chamber with said inner portion of said diaphragm, a cover member defining a vacuum chamber with said outer portion of said diaphragm and said second backing member, said cover member having means for connecting said vacuum chamber to said induction passage downstream of said throttle, said inner portion of said diaphragm and said backing members having openings for admitting air to said atmospheric pressure chamber, said second backing member having an air bleed orifice for admitting air from said atmospheric pressure chamber to said vacuum chamber, a bleed valve connected to said inner portion of said diaphragm and associated with said air bleed orifice for controlling admission of air to said vacuum chamber, said hollow stem defining a passage connecting said exhaust pressure chamber to said zone, whereby upon an increase in pressure in said zone saiD inner portion of said diaphragm displaces said bleed valve to decrease admission of air to said vacuum chamber through said bleed orifice and thereby decreases the pressure in said vacuum chamber to thereby cause said pressure responsive member to overcome the bias of said spring means and displace said valve pintle from said valve seat and increase recirculation of exhaust gases, and second spring means biasing said bleed valve to permit increased admission of air to said vacuum chamber through said bleed orifice whereby upon a decrease in pressure in said zone said second spring means displaces said bleed valve to increase admission of air to said vacuum chamber through said bleed orifice and thereby increases the pressure in said vacuum chamber to thereby permit said first spring means to displace said valve pintle toward said valve seat and decrease recirculation of exhaust gases, said bleed valve having a planar base portion and a tapered tip portion, an orifice member surrounding said air bleed orifice, said orifice member having a resilient lip receiving said tip portion of said bleed valve, and a planar seating rim receiving said base portion of said bleed valve after said tip portion has engaged said resilient lip, wherein said first diaphragm backing member has a downwardly concave annular channel to which said openings extend and at least one of said diaphragm backing members has a plurality of recesses opening from said channel, an upwardly concave annular paper filter element disposed in said channel for preventing entrance of dirt through said openings to said atmospheric pressure chamber, clip means extending through said filter element and received in said recesses for securing said filter element in said channel, and rivet means extending between said second backing member and said channel portion of said first backing member and extending through said diaphragm to securely interconnect said diaphragm and said backing members.

Claim 10

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 valve seat formed between said inlet and said outlet, and an orifice formed in said inlet and defining a control pressure zone between said orifice and said valve seat, a valve pintle associated with said valve seat for controlling flow of exhaust gases therethrough, and control means for positioning said valve pintle to maintain a substantially constant pressure in said control pressure zone, said control means including spring means biasing said valve pintle toward engagement with said valve seat, a hollow valve stem connected to said valve pintle and extending outwardly of said valve body, a pressure responsive assembly having a first diaphragm backing member secured to said valve stem, a diaphragm having a flexible inner portion defining a control pressure chamber with said backing member, said diaphragm further having a flexible annular outer portion extending radially outwardly from said backing member, and a second diaphragm backing member defining an atmospheric pressure chamber with said inner portion of said diaphragm, a cover member defining a vacuum chamber with said outer portion of said diaphragm and said second backing member, said cover member having means for connecting said vacuum chamber to said induction passage downstream of said throttle, said inner portion of said diaphragm and said backing members having openings for admitting air to said atmospheric pressure chamber, said second backing member having an air bleed orifice for admitting air from said atmospheric pressure chamber to said vacuum chamber, a bleed valve connected to said inner portion of said diaphragm and associated with said air bleed orifice for controlling admission of air to said vacuum chamber, said hollow stem defining a passage connecting said exhaust pressure chamber to said zone, whereby upon an increase in pressure in said zone saiD inner portion of said diaphragm displaces said bleed valve to decrease admission of air to said vacuum chamber through said bleed orifice and thereby decreases the pressure in said vacuum chamber to thereby cause said pressure responsive member to overcome the bias of said spring means and displace said valve pintle from said valve seat and increase recirculation of exhaust gases, and second spring means biasing said bleed valve to permit increased admission of air to said vacuum chamber through said bleed orifice whereby upon a decrease in pressure in said zone said second spring means displaces said bleed valve to increase admission of air to said vacuum chamber through said bleed orifice and thereby increases the pressure in said vacuum chamber to thereby permit said first spring means to displace said valve pintle toward said valve seat and decrease recirculation of exhaust gases, said bleed valve having a planar base portion and a tapered tip portion, an orifice member surrounding said air bleed orifice, said orifice member having a resilient lip receiving said tip portion of said bleed valve, and a planar seating rim receiving said base portion of said bleed valve after said tip portion has engaged said resilient lip, wherein said first diaphragm backing member has a downwardly concave annular channel to which said openings extend and at least one of said diaphragm backing members has a plurality of recesses opening from said channel, an upwardly concave annular paper filter element disposed in said channel for preventing entrance of dirt through said openings to said atmospheric pressure chamber, clip means extending through said filter element and received in said recesses for securing said filter element in said channel, and rivet means extending between said second backing member and said channel portion of said first backing member and extending through said diaphragm to securely interconnect said diaphragm and said backing members.