US3928966A - Flow control valve for exhaust gas recirculation system - Google Patents

Flow control valve for exhaust gas recirculation system Download PDF

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Publication number
US3928966A
US3928966A US400674A US40067473A US3928966A US 3928966 A US3928966 A US 3928966A US 400674 A US400674 A US 400674A US 40067473 A US40067473 A US 40067473A US 3928966 A US3928966 A US 3928966A
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United States
Prior art keywords
pressure
valve
valve chamber
diaphragm
chamber
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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US400674A
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English (en)
Inventor
Kenji Goto
Ryozo Mitsui
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Toyota Motor Corp
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Toyota Motor Corp
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Publication date
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Publication of US3928966A publication Critical patent/US3928966A/en
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/52—Systems for actuating EGR valves
    • F02M26/59—Systems for actuating EGR valves using positive pressure actuators; Check valves therefor
    • F02M26/61—Systems for actuating EGR valves using positive pressure actuators; Check valves therefor in response to exhaust pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/52—Systems for actuating EGR valves
    • F02M26/55—Systems for actuating EGR valves using vacuum actuators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/52—Systems for actuating EGR valves
    • F02M26/55—Systems for actuating EGR valves using vacuum actuators
    • F02M26/58—Constructional details of the actuator; Mounting thereof
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/65—Constructional details of EGR valves
    • F02M26/74—Protection from damage, e.g. shielding means

Definitions

  • a flow control valve is provided for use in an exhaust gas recirculation system of an internal combustion engine, whereby a constant flow of the recirculating gas may be maintained.
  • the valve comprises a first and second valve chamber separated by a flow orifice with a valve body being provided to effect opening and closing of the flow orifice. Exhaust gas entering the first chamber passes through the orifice into the second chamber and to the engine intake system. Located upon one side of the valve body is a diaphragm responsive to exhaust gas pressure in the first chamber and connected to move the valve body in response thereto.
  • a pressure compensating piston located in the second valve chamber has the intake manifold pressure applied thereto and is configured to balance the effects of said intake manifold pressure upon the valve body.
  • Throttling means in the form of a throttling orifice define the entrance of the exhaust gases into said first valve chamber and spring means apply, to the side of said diaphragm opposite the side to which the exhaust gas pressure is applied, a force tending to counterbalance an opposing force slightly higher the the force of atmospheric pressure acting upon the diaphragm. Atmospheric pressure is also applied to the pressure compensating piston in a direction opposite to the direction in which intake manifold pressure is applied.
  • the present invention relates generally to a flow control valve for use in an exhaust gas recirculation system for an automobile internal combustion engine. More particularly, the invention relates to a system whereby control of the flow rate of the recirculating exhaust gas may be maintained at a relatively constant level and applied at a point in the engine intake system downstream from the carburetor throttle valve.
  • the present invention may be described as a flow control system for recirculating exhaust gases in an internal combustion engine including intake means for providing a combustible mixture to said engine and exhaust means for removing exhaust gases therefrom.
  • the system of the invention comprises means defining a first valve chamber and a second valve chamber, means defining a flow orifice located between said first and said second chambers, a valve body mounted for movement to open and close said flow orifice, means for delivering exhaust gases from the exhaust means of the engine to the first valve chamber, throttle means provided in said exhaust gas delivering means and located approximately midway therein to have said first valve chamber on the downstream side thereof, means communicating the second valve chamber with the engine intake means, a diaphragm connected with the valve body and mounted to have pressure in the first valve chamber applied to one side thereof to control opening and closing of the flow orifice in accordance with said first valve chamber pressure, and a pressure compensating piston connected to the valve body and located to have pressure in the second valve chamber applied thereto, the piston
  • spring means acting upon the diaphragm to bias the valve body in the direction of closing of the flow orifice are also provided.
  • the spring means are selected to apply a biasing force to the diaphragm on one side thereof which will overcome a force slightly higher than the force of atmospheric pressure applied to the opposite side of the diaphragm.
  • atmospheric pressure is applied to the pressure compensating piston ina direction opposite to the direction in which the pressure in the second valve chamber is applied thereto.
  • FIG. 1 is a schematic diagram showing an overall exhaust gas recirculating system, utilizing the valve of the present invention
  • FIG. 2 is a sectional view of the recirculating gas flow control valve in accordance with the present invention.
  • an internal combustion engine 1 having an intake system including an intake pipe 2 and an exhaust system including an exhaust pipe 3. A portion of the exhaust emitted from the exhaust pipe 3 is directed back into the intake pipe 2 through an exhaust recirculation pipe 4.
  • a flow control valve 5, structured in accordance with the present invention, is disposed within the exhaust recirculation pipe 4 halfway between the exhaust 3 and the intake 2. The exhaust from the exhaust pipe 3 enters the valve 5 through an exhaust inlet port 6 and is emitted therefrom for delivery to the intake 2 through an outlet port 7.
  • the structure of the valve 5 of the present invention is shown in more detail in FIG. 2.
  • the valve 5 is provided with a valve casing 8 divided into a first pressure chamber 9 and a second pressure chamber 10, said chambers having formed therebetween a flow passage 11 defined by a wall extending between the two chambers.
  • the first or upper chamber 9 communicates with the exhaust pipe 3 through the exhaust inlet port 6 and the second or lower chamber 10 communicates with the intake pipe 2 through the exhaust outlet 7.
  • Throttling means in the form of a throttling orifice 12 are provided at a suitable location between the exhaust pipe 3 and the upper chamber 9, with the orifice 12 in FIG. 2 being shown at the entrance to the chamber 9.
  • a valve body 13 is disposed within the chamber 9 to open and close the flow passage 11.
  • a diaphragm chamber 14 which is sectioned into an upper chamber 16 and a lower chamber 17 by a diaphragm 15 which is connected to the .valve body 13 through a valve rod 18.
  • the valve rod 18 extends through an opening 19 defined in the wall separating the chamber 17 from the chamber 9.
  • the opening 19 is formed of a size large enough not only to enable the valve rod 18 to freely move therein but also to place the chamber 9 in flow communication with the chamber 17 so that the pressure in the chamber 9 will be applied through the chamber 17 to the underside of the diaphragm 15.
  • a spring 20 located within the chamber 16 urges the diaphragm l downwardly in the direction of closing of the orifice 11 by the valve body 13.
  • the spring force of the spring 20 is selected so that when the pressure in the chamber 9, and consequently in the chamber 17, reaches a level slightly higher than atmospheric pressure, such as, for example, when such pressure becomes slightly higher than the exhaust gas pressure during idling, the spring load of the spring 20 will be equal to the upward force acting upon the diaphragm 15.
  • a pressure compensating piston 21 adapted to counteract the force of the intake manifold pressure acting on the underside of the valve body 13 is mounted at the lower end of the valve rod 18 with the piston 21 being slidably engaged within a cylinder portion 22 provided at the bottom of the valve casing 8.
  • the internal pressure in the chamber below the valve body 13 acts upon the upper side of the piston 21 and atmospheric pressure applied through an aperture 23 formed in the bottom of the valve casing 8 acts upon the underside of the piston 21.
  • the piston 21 is configured to have a pressure area which is selected such that the force produced due to the negative intake pressure upon the valve body 13 will be cancelled. Accordingly, the force produced by pressure upon the upperside of the piston 21 will be equal in magnitude but opposite in direction to the negative pressure acting upon the valve body 13. Accordingly, the action of the valve rod 18 and of the valve body 13 will be controlled only by the force of pressure acting upon the diaphragm and by the pressure of the spring 20.
  • a labyrinth packing 24 is provided between the pressure compensating piston 21 and the cylinder portion 22 in order that air entering between the skirt of the, piston 21 and the valve casing defining the cylinder portion 22 will be controlled to a small amount so that such air will not produce adverse influence upon the engine.
  • the pressure compensating piston 21 is arranged to be smoothly slidable relative to the cylinder portion 22 and also to be resistant to wear'and heat.
  • a protective filter 25 which is adapted to prevent small particles in the exhaust gas from clogging the opening 19 which communicates the chamber 9 above the valve body with the chamber 17 below the diaphragm, thereby to ensure that smooth movement of the valve rod 18 within the opening 19 will always occur.
  • the chamber 16 located above the diaphragm 15 is arranged in flow communication either with, for example, the discharge side of an air pump 27 or with an atmospheric release pipe 28, as shown in FIG. 1, through an aperture 26.
  • a solenoid valve 29 operates to switch communication between the chamber 16 and either the air pump 27 or the atmospheric release pipe 28.
  • the solenoid valve 29 is designed so that in the case of forcibly checking recirculation of the exhaust gases under certain operating conditions, such as, when the engine speed is above a certain set level or when the temperature is below a certain set level, high pressure on the discharge side of the air pump 27 will be applied to the chamber 16 to close the valve body 13.
  • the air pump 27 is provided for supplyingsecondary air which, as is well known to those skilled in the art, is used for exhaust purification and is usually communicated with the atmospheric release pipe 28 through aperture 26.
  • the chamber 9 will'always be controlled at a pressure approximating atmospheric pressure.
  • the negative pressure of the intake pipe 2 will act upon the underside of the valve body 13, but the force produced by such negative pressure is cancelled by the pressure compensation piston 21. Accordingly, only the pressure of the exhaust gas acting upon the diaphragm 15 and the pressure of the spring 20 will operate to control the valve rod 18, so that the amount of force lifting the valve body 13 and hence controlling the flow rate of exhaust gases into the intake pipe 2, will be determined in relation with the exhaust gas pressure acting upon the diaphragm 15 and the pressure of the spring 20.
  • exhaust flow is controlled in accordance with the pressure acting upon the diaphragm 15, Le, the pressure in the chamber 9, which remains balanced against the pressure of the spring 20, which has been set to approximate atmospheric pressure, regardless of the rise or fall of the engine exhaust gas pressure.
  • the spring constant of the spring 20 is selected to be sufficiently small to render inconsequential the variation of load caused by variation of lift with respect to the setting load within the scope of the valve body lift, it is possible to maintain pressure in the chamher 9 substantially constant.
  • a throttle 30 is provided in the aperture 26 in the chamber 16 above the diaphragm for preventing pulsating motion of the diaphragm 15.
  • the area of the space 19 communicating chamber 9 with the chamber 17 is selected to be within a range which will avoid impairment of the responsiveness of the valve body.
  • a bellows mechanism may be used in the section of the valve which is comprised of the pressure compensation piston 21 and the cylinder 22 to prevent entry of air.
  • a flow control system for circulating exhaust gases in an engine including intake means for providing a combustible mixture to said engine and exhaust means for removing exhaust gases therefrom, said system comprising, in combination, means defining a first valve chamber and a second valve chamber, means defining a flow orifice between said first and second chambers, a valve body mounted for movement to open and close said flow orifice, means for delivering exhaust gases from said exhaust means to said first valve chamber, throttling means provided in said exhaust gas delivering means located to have said first valve chamber on the downstream side thereof, means communicating said second valve chamber with said intake means, a diaphragm connected with said valve body and mounted to have pressure in said first valve chamber applied to one side thereof to control opening and closing of said flow orifice in accordance with said first valve chamber pressure, an air pump for delivering secondary air to said engine exhaust means, means for selectively applying the pressure of said secondary air to the side of said diaphragm opposite the side upon which said first valve chamber pressure is applied, and a pressure compensating
  • a system according to claim 2 wherein said spring means is located to act upon said diaphragm on a side thereof opposite the side upon which pressure in said first valve chamber is applied thereto.
  • said throttling means comprises a throttling orifice located at a point midway between said engine exhaust means and said engine intake means.
  • a system according to claim 1 including means for applying atmospheric pressure to said pressure compensating piston, said atmospheric pressure being applied thereto in a direction opposite to the direction in which said pressure in said second valve chamber is applied thereto.
  • said spring means is selected to create a biasing force which equivalently counteracts a force Slightly higher than the force of atmospheric pressure acting against the side of said diaphragm opposite said spring means.
  • a system according to claim 1 including an operating rod interconnecting said diaphragm and said valve body, means defining an operating orifice through which said operating rod extends, said operating orifice being sized to permit movement of said operating rod therein and passage therethrough of pressure from said first valve chamber applied to said diaphragm, and a protective filter located in said first valve chamber between said operating orifice. and said exhaust gas delivery means to prevent impurities in said exhaust gases from passing therethrough and clogging said operating orifice.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Exhaust-Gas Circulating Devices (AREA)
  • Safety Valves (AREA)
US400674A 1972-11-30 1973-09-25 Flow control valve for exhaust gas recirculation system Expired - Lifetime US3928966A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP47119436A JPS527496B2 (ja) 1972-11-30 1972-11-30

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Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4043305A (en) * 1974-10-25 1977-08-23 Regie Nationale Des Usines Renault Control device for regulating the compositions of the inlet and exhaust gases of an internal combustion engine
US4088101A (en) * 1975-12-27 1978-05-09 Toyota Jidosha Kogyo Kabushiki Kaisha Exhaust gas purifying apparatus
US4094284A (en) * 1975-10-21 1978-06-13 Eltra Corporation Emission control system
US4109462A (en) * 1975-12-25 1978-08-29 Nippon Soken, Inc. Device for purifying exhaust gas discharged from internal combustion engine
US4158351A (en) * 1976-12-14 1979-06-19 Toyota Jidosha Kogyo Kabushiki Kaisha Flow control valve for an exhaust gas recirculation apparatus of an exhaust gas pressure control type
US4164918A (en) * 1978-02-21 1979-08-21 General Motors Corporation Exhaust gas recirculation control
US4170973A (en) * 1977-07-11 1979-10-16 Toyota Jidosha Kogyo Kabushiki Kaisha Exhaust gas recirculation system of an internal combustion engine
US4180034A (en) * 1978-05-25 1979-12-25 General Motors Corporation Exhaust gas recirculation control
US4186703A (en) * 1978-09-06 1980-02-05 General Motors Corporation Exhaust gas recirculation control
US4196707A (en) * 1978-07-31 1980-04-08 General Motors Corporation Exhaust gas recirculation control
US20080148720A1 (en) * 2006-12-26 2008-06-26 Toyota Jidosha Kabushiki Kaisha Exhaust gas purification apparatus and method for internal combustion engines
US20130291968A1 (en) * 2012-05-07 2013-11-07 Derold G. Clark Valve with Proof of Closure

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0287741U (ja) * 1988-12-26 1990-07-11
JPH03105439U (ja) * 1990-02-09 1991-10-31
JPH05139448A (ja) * 1991-11-14 1993-06-08 Kaasuru Sangyo Kk 容器等の取付け物を磁性体壁面に取付ける方法

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3749071A (en) * 1972-04-19 1973-07-31 Gen Motors Corp Exhaust gas recirculation control valve
US3756210A (en) * 1972-04-10 1973-09-04 Gen Motors Corp Exhaust gas recirculation control valve
US3797803A (en) * 1971-05-15 1974-03-19 Toyota Motor Co Ltd Control valve assembly for a gas passageway
US3799131A (en) * 1972-04-19 1974-03-26 Gen Motors Corp Exhaust gas recirculation

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3797803A (en) * 1971-05-15 1974-03-19 Toyota Motor Co Ltd Control valve assembly for a gas passageway
US3756210A (en) * 1972-04-10 1973-09-04 Gen Motors Corp Exhaust gas recirculation control valve
US3749071A (en) * 1972-04-19 1973-07-31 Gen Motors Corp Exhaust gas recirculation control valve
US3799131A (en) * 1972-04-19 1974-03-26 Gen Motors Corp Exhaust gas recirculation

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4043305A (en) * 1974-10-25 1977-08-23 Regie Nationale Des Usines Renault Control device for regulating the compositions of the inlet and exhaust gases of an internal combustion engine
US4094284A (en) * 1975-10-21 1978-06-13 Eltra Corporation Emission control system
US4109462A (en) * 1975-12-25 1978-08-29 Nippon Soken, Inc. Device for purifying exhaust gas discharged from internal combustion engine
US4088101A (en) * 1975-12-27 1978-05-09 Toyota Jidosha Kogyo Kabushiki Kaisha Exhaust gas purifying apparatus
US4158351A (en) * 1976-12-14 1979-06-19 Toyota Jidosha Kogyo Kabushiki Kaisha Flow control valve for an exhaust gas recirculation apparatus of an exhaust gas pressure control type
US4170973A (en) * 1977-07-11 1979-10-16 Toyota Jidosha Kogyo Kabushiki Kaisha Exhaust gas recirculation system of an internal combustion engine
US4164918A (en) * 1978-02-21 1979-08-21 General Motors Corporation Exhaust gas recirculation control
US4180034A (en) * 1978-05-25 1979-12-25 General Motors Corporation Exhaust gas recirculation control
US4196707A (en) * 1978-07-31 1980-04-08 General Motors Corporation Exhaust gas recirculation control
US4186703A (en) * 1978-09-06 1980-02-05 General Motors Corporation Exhaust gas recirculation control
US20080148720A1 (en) * 2006-12-26 2008-06-26 Toyota Jidosha Kabushiki Kaisha Exhaust gas purification apparatus and method for internal combustion engines
US7918084B2 (en) * 2006-12-26 2011-04-05 Toyota Jidosha Kabushiki Kaisha Exhaust gas purification apparatus and method for internal combustion engines
US20130291968A1 (en) * 2012-05-07 2013-11-07 Derold G. Clark Valve with Proof of Closure
US9683676B2 (en) * 2012-05-07 2017-06-20 Derold G CLARK Valve with proof of closure

Also Published As

Publication number Publication date
JPS4977027A (ja) 1974-07-25
JPS527496B2 (ja) 1977-03-02

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