GB2251918A - Gas flow control valve - Google Patents

Gas flow control valve Download PDF

Info

Publication number
GB2251918A
GB2251918A GB9101248A GB9101248A GB2251918A GB 2251918 A GB2251918 A GB 2251918A GB 9101248 A GB9101248 A GB 9101248A GB 9101248 A GB9101248 A GB 9101248A GB 2251918 A GB2251918 A GB 2251918A
Authority
GB
United Kingdom
Prior art keywords
valve
inlet
outlet
flow control
gas flow
Prior art date
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.)
Withdrawn
Application number
GB9101248A
Other versions
GB9101248D0 (en
Inventor
Keith Ransom
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ford Motor Co
Original Assignee
Ford Motor Co
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Ford Motor Co filed Critical Ford Motor Co
Priority to GB9101248A priority Critical patent/GB2251918A/en
Publication of GB9101248D0 publication Critical patent/GB9101248D0/en
Publication of GB2251918A publication Critical patent/GB2251918A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
    • F01N3/22—Control of additional air supply only, e.g. using by-passes or variable air pump drives
    • F01N3/227—Control of additional air supply only, e.g. using by-passes or variable air pump drives using pneumatically operated valves, e.g. membrane valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
    • F01N3/22—Control of additional air supply only, e.g. using by-passes or variable air pump drives

Abstract

A gas flow control valve 10 for use in internal combustion engine exhaust systems has a valve housing 11 with inlet 14 and outlet 15 interconnected by a valve chamber 12, a seat 13 being defined by the valve chamber 12 intermediate of the inlet 14 and outlet 15. A valve closure member 16 is slidingly located coaxially of the valve chamber 12. A pressure differential actuator has a diaphragm 25 secured to the closure member 16. a fluid tight chamber 30 on one side of the diaphragm 25 is connected to the inlet 14 while a fluid tight chamber 31 on the other side of diaphragm 25 is connected to the outlet 15, so that the pressure differential across diaphragm 25 will cause the closure member 16 to close the valve seat 13 when pressure at the outlet 15 is in excess of pressure at the inlet 14. <IMAGE>

Description

GAS FLOW CONTROL VALVES The present invention relates to gas flow control valves and in particular to a valve for controlling flow of gas in one direction.
In internal combustion engine exhaust systems with catalytic convertors, in order to assist catalyst lightoff, air may be pumped to the exhaust manifold of the engine so that the air will react with the exhaust gases to preheat the catalyst. In such systems, air is pumped to the exhaust manifold for several minutes after starting the engine and must then be shut down quickly.
In order to avoid possible damage to the pump, for example melting of hoses or plastic components, it is essential to ensure that there is no backs low of hot exhaust gases from the exhaust system.
The present invention provides a gas flow control valve which will positively prevent such backf low.
According to one aspect of the present invention a gas flow control valve comprises a valve housing defining a valve seat, the housing having an inlet on one side of the valve seat and dn outlet on the other side of the valve seat, a valve member having a stem slidably mounted with respect to the housing coaxially of the valve seat and a valve head which at one extreme of movement of the valve member will engage and close the valve seat, the end of the valve stem remote from the valve head extending into a gas-tight chamber, a flexible diaphragm being mounted between a wall of the chamber and the stem of the valve member to divide the chamber into two gastight compartments, one compartment being connected to the valve housing on the inlet side of the valve seat and the other compartment being connected to the valve housing on the outlet side of the valve seat, so that when the pressure at the inlet is in excess of the pressure at the outlet, the pressure differential across the diaphragm will move the valve head away from the valve seat and when the pressure at the inlet is less than the pressure at the outlet, the pressure differential across the diaphragm will move the valve head into engagement with the valve seat.
The valve mechanism described above will thus permit flow of gas from inlet to outlet whilst positively preventing flow of gas from outlet to inlet.
An embodiment of the invention is now described, by way of example only, with reference to the accompanying drawing which illustrates diagrammatically, a gas flow control valve in accordance with the present invention.
The gas flow control valve 10 illustrated in the accompanying drawing comprises a valve housing 11 having an axial through bore 12 with a shoulder formation partway along its length defining a valve seat 13. An inlet 14 is provided to the bore 12 on one side of the valve seat 13, the end of the bore 12 on the other side of the seat 13 defining an outlet 15.
A valve member 16 is located coaxially of the bore 12, a valve stem 17 being slidably mounted through a plug 18 in the end of bore 12 remote from outlet 15. A valve head 19 is located at the end of valve stem 17 adjacent the seat 13, so that the valve member may be moved between a position (shown in full line) in which the valve head 19 engages and closes the valve seat 13 and a position (shown in broken line) in which the valve head 19 is spaced away from the valve seat 13.
A cylindrical gas-tight casing 20 is mounted by suitable means on housing 11 coaxially of the bore 12. The end of valve stem 17 remote from valve head 19 extends into the casing 20 and is sealed with respect thereto by means of a flexible bellows unit 21. The cylindrical casing 20 is formed from two parts 22 and 23 which are clamped together in suitable manner. A flexible annular diaphragm 25 is mounted within cylindrical casing 20, an outer peripheral bead portion 26 being clamped between parts 22 and 23 of casing 20, to provide a gas-tight seal therebetween and the inner periphery 27 of the diaphragm 25 is secured to a disk 28 which is mounted on the end of valve stem 17. The diaphragm 25 thereby divides the casing 20 into two gas-tight compartments 30 and 31.
Compartment 30 is connected to the inlet 14 by means of a bore 32 passing through housing 11 and casing 20, and compartment 31 is connected via an inlet 33, pressure tube 34 and bore 35 to the bore 12, on the side of the seat 13 adjacent to outlet 15.
The valve mechanism described above is suitable for use in a secondary air system for an internal combustion engine in which when the engine is started up, air is pumped to the engine's exhaust manifold in order to heat up an exhaust catalyst to its optimum operating temperature. The output of a positive displacement air pump is connected to the inlet 14 of valve 10 and the outlet 15 of the valve 10 is connected to the exhaust manifold. When the pump is switched on, the pressure P1 at the inlet 14 and in compartment 30 of casing 20 will be in excess of the pressure P2 at the outlet 15 and in compartment 31 of casing 20. The pressure differential across the diaphragm 25 will thus cause the valve member 16 to lift away from valve seat 13, thus permitting air to pass from the inlet 14 to the outlet 15 and into the exhaust manifold.If the engine should backfire while air is being supplied to the exhaust manifold and P2 becomes greater than P1, the pressure in compartment 31 will then be in excess of that in compartment 30 and the pressure differential across the diaphragm 25 will move the valve member 16 downwardly (as illustrated) so that valve head 19 will engage and close the valve seat 13, thereby preventing exhaust gases from being fed back to the pump. When the pump is switched off, pressure P1 falls below pressure P2 so that the pressure differential across diaphragm 25 will again close the valve preventing the passage of exhaust gases to the pump.
The valve described above thus acts as a shut-off valve preventing blow back of exhaust gases to the air pump, so that plastics materials may be used in the air pump and/or the hoses therefrom. Moreover, the sensitivity of the valve to backflow is such that the valve itself may include plastic moulded parts, as the establishment of back pressure upon closure of the valve will prevent the exhaust gases from reaching the valve.
Although the valve disclosed above is suitable for use in secondary air systems for internal combustion engines, it may be used in other applications where uni-directional gas flow is required and backs low must be avoided.

Claims (7)

1. A gas flow control valve comprising a valve housing defining a valve seat, the housing having an inlet on one side of the valve seat and an outlet on the other side of the valve seat, a valve member having a stem slidably mounted with respect to the housing coaxially of the valve seat and a valve head which at one extreme of movement of the valve member will engage and close the valve seat, the end of the valve stem remote from the valve head extending into a gas-tight chamber, a flexible diaphragm being mounted between a wall of the chamber and the stem of the valve member to divide the chamber into two gas-tight compartments, one compartment being connected to the valve housing on the inlet side of the valve seat and the other compartment being connected to the valve housing on the outlet side of the valve seat, so that when the pressure at the inlet is in excess of the pressure at the outlet, the pressure differential across the diaphragm will move the valve head away from the valve seat and when the pressure at the inlet is less than the pressure at the outlet, the pressure differential across the diaphragm will move the valve head into engagement with the valve seat.
2. A gas flow control valve according to Claim 1 in which the valve housing has a through bore with a shoulder portion defining a valve seat, the valve member being slidably located coaxially of the through bore, a cylindrical gas tight casing being mounted on the valve housing coaxially of the through bore, the diaphragm extending between the cylindrical wall of the casing and the valve stem.
3. A gas flow control valve according to Claim 2 in which an inlet is provided to the through bore in the valve housing, at a position intermediate of the valve seat and the end of the through bore adjacent the cylindrical casing, the end of through bore remote from the cylindrical casing forming an outlet.
4. A gas flow control valve according to Claim 2 or 3 in which the valve head engages the valve seat on the side thereof adjacent the cylindrical casing, the compartment defined by the diaphragm within the cylindrical casing adjacent to the valve housing being connected to the inlet while the compartment remote from the valve housing is connected to the outlet.
5. A gas flow control valve according to Claim 4 in which the inlet is connected to the compartment defined in the cylindrical casing by means of a bore through the valve housing.
6. A gas flow control valve according to Claim 4 or 5 in which the outlet is connected to the compartment defined in the cylindrical casing by means of an external connection.
7. A gas flow control valve substantially as described herein, with reference to, and as shown in the accompanying drawing.
GB9101248A 1991-01-19 1991-01-19 Gas flow control valve Withdrawn GB2251918A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB9101248A GB2251918A (en) 1991-01-19 1991-01-19 Gas flow control valve

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB9101248A GB2251918A (en) 1991-01-19 1991-01-19 Gas flow control valve

Publications (2)

Publication Number Publication Date
GB9101248D0 GB9101248D0 (en) 1991-02-27
GB2251918A true GB2251918A (en) 1992-07-22

Family

ID=10688749

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9101248A Withdrawn GB2251918A (en) 1991-01-19 1991-01-19 Gas flow control valve

Country Status (1)

Country Link
GB (1) GB2251918A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2276932A (en) * 1993-04-07 1994-10-12 Shell Int Research Surface dressing equipment and method
GB2290367A (en) * 1994-06-11 1995-12-20 Delta Fluid Products Ltd Fluid flow regulator
EP1046796A3 (en) * 1999-04-23 2000-11-22 Bayerische Motoren Werke Aktiengesellschaft Secondary air valve for supplying extra air to exhaust gas stream of an internal combustion engine
EP1099832A3 (en) * 1999-11-12 2003-07-02 Pierburg GmbH Control element

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB506396A (en) * 1937-11-25 1939-05-25 Coxeter & Son Ltd Improvements in and relating to fluid flowmeters
GB832356A (en) * 1956-09-04 1960-04-06 Gas Council Improvements in or relating to non-return valves
US3776268A (en) * 1972-06-02 1973-12-04 Emerson Electric Co Stepped opening fluid pressure operated gas valve
GB1486837A (en) * 1973-09-28 1977-09-28 Nissan Motor Internal combustion engine having a secondary air pressure control valve for controlling air flow to the exhaust system
US4120480A (en) * 1976-02-24 1978-10-17 Toyota Jidosha Kogyo Kabushiki Kaisha Valve device for an exhaust gas recirculation system of an internal combustion engine

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB506396A (en) * 1937-11-25 1939-05-25 Coxeter & Son Ltd Improvements in and relating to fluid flowmeters
GB832356A (en) * 1956-09-04 1960-04-06 Gas Council Improvements in or relating to non-return valves
US3776268A (en) * 1972-06-02 1973-12-04 Emerson Electric Co Stepped opening fluid pressure operated gas valve
GB1486837A (en) * 1973-09-28 1977-09-28 Nissan Motor Internal combustion engine having a secondary air pressure control valve for controlling air flow to the exhaust system
US4120480A (en) * 1976-02-24 1978-10-17 Toyota Jidosha Kogyo Kabushiki Kaisha Valve device for an exhaust gas recirculation system of an internal combustion engine

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2276932A (en) * 1993-04-07 1994-10-12 Shell Int Research Surface dressing equipment and method
GB2276932B (en) * 1993-04-07 1997-02-05 Shell Int Research Surface dressing equipment and method
GB2290367A (en) * 1994-06-11 1995-12-20 Delta Fluid Products Ltd Fluid flow regulator
EP1046796A3 (en) * 1999-04-23 2000-11-22 Bayerische Motoren Werke Aktiengesellschaft Secondary air valve for supplying extra air to exhaust gas stream of an internal combustion engine
EP1099832A3 (en) * 1999-11-12 2003-07-02 Pierburg GmbH Control element

Also Published As

Publication number Publication date
GB9101248D0 (en) 1991-02-27

Similar Documents

Publication Publication Date Title
US3626978A (en) Check valve
US6321533B1 (en) Exhaust passage switching unit and method for internal combustion engine
JP2747428B2 (en) Demand fuel pressure regulator
JPS6122163B2 (en)
SE9700982L (en) Procedure for controlling an internal combustion engine at start-up and engine for carrying out the procedure
US4088101A (en) Exhaust gas purifying apparatus
EP1447545B2 (en) Valve for an exhaust pipe
GB2251918A (en) Gas flow control valve
EP0496497B1 (en) Gas flow control valve
US20040041119A1 (en) Pressure-regulating valve
EP0496487B1 (en) Emission control system
KR20070030707A (en) Muffler
CN112020622B (en) Damping check valve with multi-pressure operation
US20090107131A1 (en) Exhaust pressure control valve
US20020005318A1 (en) Valve in an exhaust gas muffler device of a motor vehicle
US3999737A (en) Flow control valve for exhaust gas purifying system
US10787942B2 (en) Valve component for regulating or controlling a fluid pressure
US3942321A (en) Engine secondary air control valve
GB2151700A (en) IC engine turbocharger and exhaust gas by-pass valve arrangement
US4064894A (en) Vacuum reducer valve
US3675417A (en) Engine starting system with combination air relay and check valve
US4029074A (en) Fuel valves
US3820328A (en) Device for the post combustion of the unburnt substances in the exhaust gases of the internal combustion engine of a motor vehicle
JP4674561B2 (en) Valve device
JP2846268B2 (en) gas turbine

Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)