CA2157717C - Anti-permeation filter for vapor management valve - Google Patents
Anti-permeation filter for vapor management valve Download PDFInfo
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- CA2157717C CA2157717C CA002157717A CA2157717A CA2157717C CA 2157717 C CA2157717 C CA 2157717C CA 002157717 A CA002157717 A CA 002157717A CA 2157717 A CA2157717 A CA 2157717A CA 2157717 C CA2157717 C CA 2157717C
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- vacuum
- flow
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- chamber
- inlet
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Classifications
-
- 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
- F02M25/00—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
- F02M25/08—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture adding fuel vapours drawn from engine fuel reservoir
- F02M25/0836—Arrangement of valves controlling the admission of fuel vapour to an engine, e.g. valve being disposed between fuel tank or absorption canister and intake manifold
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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
- F02M25/00—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
- F02M25/08—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture adding fuel vapours drawn from engine fuel reservoir
- F02M2025/0845—Electromagnetic valves
Abstract
A flow regulator for automotive vehicles of the type having a computer-controlled emission control system. The flow regulator has an electric vacuum regulator (EVR) valve that regulates the vacuum signal provided to a vacuum regulator valve in accordance with the current signal supplied to the EVR valve by the engine controller unit. The vacuum regulator valve includes a control chamber and a valve chamber that are separated by a movable diaphragm valve assembly. The preload on a biasing spring acting on the diaphragm valve assembly can be adjusted during calibration of the flow regulator for setting a first calibration point. An adjustable flow restrictor provided in the inlet portion of the vacuum regulator valve can be varied during calibration for setting a second calibration point. In addition an anti-permeation filter is provided for inhibiting the venting of fuel vapors to atmosphere that have permeated through the diaphragm valve. In operation the flow regulator is operable to generate substantially linear output flow characteristic between the two calibration points as a function of the current signal in a manner that is independent of changes in manifold vacuum.
Description
89-OON-583(LE) ~ 2157717 Attorney Docket: 1203~0081 ANTI-PERMEATION FILTER FOR VAPOR MANAGEMENT VALVE
BACKGROUND OF THE INVENTION
The ~rese~l invention relates ~e~erally to elec~on ally-co"l,ùlled flow reg~ tors of the type used in aulumoli~/e vehicles equipped with computer-conl~olled er"ission control systems.
As is known virtually all modern automotive vehicles are equipped with emission control systems that are operable for limiting the eu lission of hydrocarbons into the atmosphere. Such emission control systems typically include an eva~.orali~re emission control system which traps fuel vapors from the fuel tank in a carbon filled can;sler and a purge system which draws the vapors from the canisler into the engine intake system. In this rllallller~ fuel vapors from the fuel tank are delivered into the engine for suhseq~ ~ent combustion.
Conve"lional eva,uoralive e",issiol, control systems are equipped with elec~o"-cally controlled purge valves for regulating the flow rate of fuel vapors introrl~ ~ce~ into the intake system in response to specific engine operating parameters.
Conventional purge valves col",urise pulse width modul~tion (PWM) solenoid valves which are res~.ol,sive to a duty cycle control signal from the engine computer.
However PWM purge valves provide uneven flow characteristics particularly at lowengine speeds and also do not provide consislent flow control independent of valicliolls in manifold vacuum.
In view of increasingly stringent emission regulations the demands on the evaporative e"l.ssioll control system have increased dramalically. In particular in order to satisfy current EPA emission requirements the flow capability of the Attorney Docket: 120~00081 evaporative e" ,;ssion system must be increased. To achieve this result within the EPA
city test cycle, it is thererore necessa~ ~ to provide purge flow at engine idle speeds.
Moreover, purge flow control must also be accurately regulated so as not to cause cce~ hle excursions in overall engine output emissions.
To provide such enhanced flow control, it is desirable to have the output flow cl,aracteri~lics of the purge valve be ,~.,o,uo,lional to the duty cycle of the electronic control signal applied to the valve, even at low engine speeds, and yet be independent of variations in the manifold vacuum. Accordingly, the output flow of the valve should be sub~ldl~lially constant at a given duty cycle control signal and be co"ltc"-'~le in response to regul~te~ changes in the duty cycle regardless of va, ialio"s in manifold vacuum. Moreover, it is also desirable that the output flow of the valve vary s~ sl~, Itially linearly from a preddle,I~lined "minimum" flow rate at a "start-to-open" duty cycle to a specified "~"axi"lum" flow rate at 100% duty cycle.
The above performance ~el "a"ds have prompted the recent dcvclo~.",ent of a purge flow regulator that combines an electric vacuum regulator (EVR) solenoid valve with a diaphragm-type vacuum regulator valve to provide thedesired continuous controlled flow characteri~lics independent of variations in manifold vacuum. In particular, the EVR solenoid valve is connected to the diaphragm vacuum regulator valve so as to regulate the vacuum signal supplied to the reference side of the dia~h~agm valve in accorda"ce with the control signal from the engine computer.
A closure member, associated with the opposite side of the diaphragm, co, llrols flow from the input port to the output port of the vacuum regulator valve in response to 215 7 717 Attorney Docket: 1203-00081 regulated movement of the diaphragm. Since the EVR valve is in communication with aLmos~here and a vacuum source, such as the intake manifold of the engine, the amount of vacuum (i.e., the vacuum signal) provided to the reference side of the dia, ~l "agm is proportional to the electric control signal supplied to the EVRvalve by 5 the on-board engine control computer. Thus, output flow through the vacuum reg~ ~Iqtor valve is controlled by the duty cycle of the control signal applied to the EVR
valve.
Examples of ele~onically controlled flow purge regulators of this type are Iisclosed in U.S. Pat. No. 4,534,378 to Cook and U.S. Pat. No. 5,050,568 to Fox.
10 However, for such conventional flow regulators to satisfy the above-described ~e,~"na,1ce specilicalions, the purge flow regul~tor must be precisely calibrated. It has been ,urol ~ose~ I to calibrate the purge flow regul -tor by adjusting the characteri~lics of the EVR solenoid valve. In particular, the preload on the armature bias spring of the EVR valve is adjusted for setting the minimum flow rate at the "start-15 to-open" duty cycle. Such changes in the magnitude of preload on the armature bias spring effectively ~ rlaces the pe,ru""ance curve without changing its slope. In ition, the reluctance of the solenoid flux path is adjusted for setting the n ,axi" ~um flow rate at the 100% duty cycle. However, changes in reluctance result in a cor~s~,onding change in the slope of the pel ror"~a"ce curve. As can be appreci~te~l, 20 this calibration alJproach is problematic in that each adjustment affects the other, such that the two calibration adjustments are depen-lel ll and cumulative in nature. As such, it typically requires several iterations to "zero-in" on both of the desired calibration Attorney Docket: 120~00081 points. Accordi. Igly while such conventional flow regulators are generally successful in automotive emission control systems for their intended purpose there is a continuing need to develop alle",alives which meet the above-noted performance specifications and can be manuf~ctl~red and calibrated in a more erricia"l and cost 5 effective "~anner.
In view of the above an improved vapor management valve was dcveloped which combines an EVR valve and a vacuum regulator valve for generating an output flow characieri~lic that is ~,rol ollional to the duty cycle of the electrical control signal and yet is independent of variations in manirold vacuum this vapor management valve being disclosed in commonly-owned U.S. Pat. No. 5277167 issued to DeLand et al. Upon continued dcv~lo,u,llent of this commercially-successful vapor manayen ,e, ll valve it was discovered that fuel vapor can per" ,eale through the flexible dia~l "agm mer~lbrane particularly when the system is inactive. Accordingly in an effort to provide further gains in emission control an anti-permeation filter has been developed with adsGr,uli~/e ,uro,ue, lies which prevents the fuel vapors from being vented to the atmos,vhere. During normal oper~lion of the vapor management valve the adsorbed vapors are extracted from the anti-permeation filter by the inlet air flow and are delivered to the engine for subse~uent combustion.
SUMMARY OF THE INVENTION
Accordingly it is the primary object of the present invention to provide a modified version of the vapor management valve disclosed in commonly owned U.S.
`~ 21S7717 - Attorney Docket: 1203 00081 Patent No. 5 277 167 which has means for coull olling the vapors which may otherwise pe" nedle the dia,cl ,ragm and be vented to the almosphere. Particularly the present invention provides a means of adsorbing fuel vapors which permeate the dia,c)h, agm and later during normal operalion releasi"y the adsorbed vapors into the flow of air ,uassi, Iy into the intake ~ 1 lani~dld.
Ad.litio. ,al objects and ad~a, Itdyes of the present invention will become a~.t.arent from a reading of the following detailed desc-i~Lion of the ~refer,~dembodiment taken in conjunction with the acco,,,,uanyin9 drawings and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a se~ional view of an ele_t,on-~qlly-controlled flow regulator shown Jiay- ~rr ma~ically ~ssoc; ~ . I with an ev~,uord~ e em;ssiol1s control system and equipped with an anti-per"lealion filter according to a first ~,reret,ed embodiment of the ,uresenl invention; and FIG. 2 is a view similar to Fig. 1 showing an aller,lalive location for the anti-per")ea~io" filter of the ~rese, ll invention.
DESCRIPTION OF THE l Ht~t~RED EMBODIMENT
In yeneral the present invention is directed to a modified construction for the vapor management valYe disclosed in com~only owned U.S. Patent No.
5 277 167to DeLand et al. However to provide a basic understanding of the structure of the vapor management _ 2157717 Attorney Docket: 1203 00081 valve as it relates to the present invention the following structural overview is provided.
Thus a preferred embodiment of an electronically-conlrolled flow regulator is disclosed which is ada~.~e.l for use in an evdporali~e emissio~ control system for purging fuel vapors collected in a charcoal canisler into the intake system of the vehicle s internal 5 combustion engine. However it will be readily appare"l that the improved flow regul?tor has utility in other vehicular flow controlling applications.
In the drawings wherein for purposes of illustration is shown a pre~r~ad embodiment of a vapor manageme,1l valve incor,uor~li"g the present invention ele~Lronically controlled flow regl~l~tor 10 is lisclosed as having an elec~,ol1ically-10 ~ctu~ted vacuum regulator ("EVR") valve 12 and a vacuum regulator valve 14. By wayof example flow regulator 10 is shown as a vapor management valve of the type ~csoci ~e~ with a conve"liol ,al evaporali~/e e" lissiG" control system for an auLo,noli~/e vehicle. More specifically fuel vapors vented from a fuel tank 16 are cc"Qcted in a cl ,arcoal ca";~lar 18 and are controllably purged by vapor management valve 10 into 1~ the intake system 20 (i.e. the intake manifold) of the vehicles i~Ler"al combustion engine in response to electrical COI Illol signals sl Irrlie~ to EVR valve 12 by a remote engine controller unit ("ECU") 22. While EVR valve 12 and vacuum regulator 14 are shown assel, Ibled as a unitary flow regula~or 10 it is to be understood that the valves could be se,uarate components that are i"Lerco""ected by suitable tube connections 20 in a known manner.
As seen in FIG. 1 EVR valve 12 is an encarslJl~te~i solenoid assembly 24 secured to an upper valve housing 26 of vacuum regulator valve 14 having a filter Attorney Docket: 1203 00081 cover 28 removably connected to a top portion thereof. Solenoid assembly 24 inclu~les a bobbin 30 ral.ricaled from a non-magnetic nylon-tape material having a plurality of coil windings 32 wound thereon. The ends of coil winding 32 are elect,ically connected to a pair of terminal blades 33. A magnetic pole piece 34 5 eAlen.ls through a hollow central core of bobbin 30 and in turn has a central bore 36 formed therein which serves as an air r~ss~eway which communicates with an air inlet 38. Al" ,os,uheric air identified by block 40 is admitted into air inlet 38 through a plurality of apertures 42 formed in filter cover 28 and is filtered by an anti-permeation filter assembly 44 located inside filter cover 28. The anti-permeation filter assembly 44 10 contains a layer of a SlliP~'Q adsorptive ~alerial 45 such as for example activated c:l,alcoal that is sandwashed between two layers 47 of a di~rerent porous filtering mal~:rial. The l~iscl ,arge of atmospheric air from the l,uLlum of central bore 36 in pole piece 34 is controlled by a flat disk-type magnetic armature 48 which is adapted to seat against a non-magnetic valve seat member 48 that is fixed to a lower end of pole piece 34. The valve seat member 48 has a central bore 50 formed therein having a diameter s~ sl~-,lially equal to the o~tsirle diameter of pole piece 34. The lower .ullio,, of valve seat member 48 has a radially enlaryed annular flange 52 which acco"~,oodates a shallow col"~le,rorce 54 formed in a bottom face 56 of valve seat member 48. The resulting annular-shaped bottom face 56 defines a valve seat and 20 is prere(ably ll,acllil led with a slight radial back taper to provide a circular "line" seal with flat disk armature 46.
` 2157717 Attorney Docket: 1203-00081 During asse" ,l,ly valve seat member 48 is installed on the lower end of pole piece 34 in a fixture that automatically sets the axial position of valve seat surface 56 relative to an end face 58 of pole piece 34. More specifically when pole piece 34 is inserted into bore 50 a slightly oversized knurled region 60 of pole piece 34 5 embeds in the inner wall of valve seat bore 50 to create a tight frictional engagement between the two components. This is ;~ JG~ since the axial distance between end face 58 of pole piece 34 and seat surface 56 of valve seat member 48 defines the ,urinlary or working air gap between pole piece 34 and armature 46 in the "closed"
valve ~.osilio, l when EVR valve 12 is fully assembled.
10Surrounding the top end of pole piece 34 is an annular-shaped magnetic flux c~l'ector ring 62 that is co""euted to a magnetic L-frame member 64. L-frame ",e"~Ler 64 ino~ es an annular-shaped lower seymenl 66 that surrounds armature 46. Thus when solenoid assembly 24 is e"eryi~ed by current flow through coil winding 32 the magnetic flux path is ~l~i"ed by pole piece 34 armature 46 L-frame 15member 64 and flux collector ring 62. The combined pole piece 34 in valve seat ",enlL,er 48 sub-asse"lbly is shown inserted into an enlaryed bore section 68 of bobbin 30 until the top end of pole piece 34 is suL,sta"lially flush with the top surface of flux collector ring 62. A ~ tionally bond valve seat member 48 within bore section 68 of bobbin 30 ridge-like bars 70 ror",ed on the outer wall surface of valve member 20 48 embed on or "bite" into the inner wall surface of bore 68 to resist withdrawal ther~,o",. In addition the tight seal formed between bobbin 30 and valve seat Attorney Docket: ~20~ Q0081 m~"~Ler 48 serves to inhibit leakage of atmospheric air from air inlet 38 around the o~ e of seat member 48.
Flux e~"e~tor ring 62 is installed on the top of bobbin 30 and L-frame .nember 64 is installed with lower segment 66 thereof place over the bottom of tlobt n 5 30. L-frame member 64 has a pair of depending tabs (not shown) which are adapted to mate with corles~.G"ding recesses formed on oprosite sides of flux collector ring 62 for mechanically joining the two components. With the magnetic segments joined to wound bobbin 30 the entire sub-assei,lbly is encaps~ ted in an injection mode which forms a housing 72 for solenoid asse"lL,ly 24. The injection molding process 10 completely e"closes and seals solenoid asse~,lL,ly 24 while simultaneously forming a plug-in rece~ cle 74 e n~losi,1y terminal blades a mounting flange 76 for filter cover 28 and a lower connecting flange 78 for mating with upper valve housing 26.
The lower connecting flange 78 of housing 72 for solenoid asse"lbly 24 is shown retained and sealed within e,xle" ~al cavity 80 formed in upper valve housing 15 26. Moreover the circular-shaped cavity defined by the inner diameter of lower coi.ne~iny flange 78 of solenoid housing 72 defines an EVR chamber 82 below armature 46 that selectively communicates with air inlet 38 via central bore 36. A non-magnetic cup sl ,a~.ed member 84 is ,1i51 ose- I within EVR chamber 82 for s~ o, li~1g armature 46 in an "open" valve position (FIG.1) ~isplnce~ from valve seat member 48.
20 The inside ~lia"~eter of EVR chamber 82 is slightly grealer than the diameter of armature 46 to permit axial movement yet confine lateral movement of armature 46 therein. To facilildle air flow around the periphery of armature 46 when it is displaced Attorney Docket: 1203~0081 from sealed engagement (i.e. the "closed" valve position) with valve seat member 48 armature 46 has a plurality of radially-sr~ce~l notches 86 formed along its peripheral edge and cup member 84 has a plurality of slots 88 formed therein for providing a communication pathway between pole piece central bore 36 and EVR chamber 82.
With continued reference to FIG.1 vacuum regulator valve 14 is shown as a vacuum-operable dia,.~l "agm valve having a control chamber 90 formed within upper housing 26 and above a movable dia,vl ,r~gm valve asse~llLly 92 and a valve chamber 94 formed within a lower housing 86 below diaphragm valve assembly 92.
In a~ tion a vacuum inlet shown as nippled col,l,e~;lor 98 is formed in upper housing 26 and has a r~ss~ge 100 which comml",icales with col)lrol chamber 90 through a flow-reslric~i~re orffice 102. Nippled connector 98 is adapted for connection via suitable tubing (not shown) to a vacuum signal source r~arnely manifold vacuum for the intake "~a"i~. d of the engine idenli~ied by block 104. Moreover controlchamber 90 communicates with EVR chamber 82 via an orifice 105 formed in the L.ullo, n of exler~ ,al cavity 80 such that the vacuum signal (negative pressure) delivered to control chamber 90 from EVR valve 12 is a co"lrolla.l portion of the vacuum input at connector 98 as determined by the eleullical control signal supplied by ECU 22 to windings 32 of solenoid asse" ~LIy 24. Aller"dli~ely it is conle" ,,ulaled that the vacuum inlet could be posiliol ,ecJ to communicate directly with EVR cl ,~mber 82.
Control cl,an-lL,er 90 is divided into two distinct portions namely an attenuation or "damping" chamber 106 and a referel,ce chamber 108 by a damping ring 110. In s~eneral damping chamber 106 is located intermediate to EVR chamber Attorney Docket: 1203~0081 82 and rerere"ce chan,ber 108 and is operable for attenuating fluctuations in the vacuum signal sl ~pr'i~ed to rerere"ce chamber 108 and diaphragm valve assembly 92 upon actuation of E~VR valve 12. More particularly damping ring 110 is an annular "emL,er which is retained between an outer wail portion 114 and an inner wall portion 116 of upper housing 26 for sey,eya~ y dalll,ui,ly chamber 106 from reference chamber 108. Damping chamber 106 is located above damping ring 110 while reference chamber 108 is loc~te~i below damping ring 110 and includes a central cavity 118 defined by circular inner wall portion 116 so as to act over the entire top surface of .Jia~l"agm valve asse",bly 92. One or more damping orifices 120 are formed in ~lal l l,uing ring 110 to attenuate fl~ ~ctu~tions in the vacuum signal supplied to vacuum regulator valve 14 upon ~ tion of EVR valve 12 which in turn inhibits ~",desirable oscillation (i.e. 'flutter") of dia~ l,ragm valve assembly 92. Mores~.ecifically since ECU 22 surr' es a sawtooth waveform ,urererably at about 100 Hz to drive solenoid asser,lbly 24 of E~VR valve 12 direct ar.l lic liol1 of the vacuum signal 1 ~ in EVR c;l ,amLer 82 to diapl1ray"~ valve asse~ ~ Ibly 92 in control chamber 90 may cause dia,.~l,rag,n valve asse"lL,ly 92 to osc~ te. Thus it is desirable to isolate diaphragm valve assembly 92 from the 100 Hz vacuum fll ~ctl l~tion by providing .lal l l~ing chamber 106 with a larger volume than EVR cl ,a" Iber 82 for effectively reducing the magnitude of any pressure fluctu~tions. In addition damping orifice 120 is sized to provide the amount of resl,i~i~/e flow necessa~y to bala~ce the vacuum pressure between .J~II~J-n9 chamber 106 and rererence chamber 108 such that a balanced vacuum is Attorney Docket: 1203~0081 established in control chamber 90 that matches the vacuum signal in EVR chamber 82.
To provide means for regulating the purge flow of fuel vapors from can;sler 18 in the engine s intake system 20 lower housing 96 of vacuum reg~ torvalve 14 inc~u~les a nippled inlet coi "~e~or 128 adapted for connecting inlet pA~s~geway 130 to canisler 18 via suitable tubing (not shown) and a nippled outlet connector 132 adapted for connecting outlet p~cs~-Jeway 134 to intake manHold 20of the engine. Vacuum-~ctu~te~ dia,, l ,ragm valve assembly 92 is comprised of a rigid piston 136 and a flexible diaphragm 138 that are retained between valve housings 26 and 96 for co, lltolle.l axial movement to regulate the purged flow from canister 18 and inlet p~-ss~geway 130 to outlet p~-ss~geway 134 in the engine s intake manifold 20.
In addition inlet l ~ss~-Je~/vay 130 comm~ tes with valve chamber 94 via inlet orifice 140. Valve cl ,ari Iber 94 is adapted to selectively communicate with outlet ~ ~cs~geway 134 via an exit tube 142 in res~onse to the axial movement of a ,uop~.el-type closure member 146 in a direction away from an annular valve seat 148 formed at one end of exit tube 142.
Poppet-type closure member 146 is integrally associaled with an underside portion of dia,.~l ,r~y", valve asse"lL,ly 92 while the upper side of diapl ,r~y", valve assembly 92 inc~ QS a first spring retainer 150 which is preferably inley, al with piston 136. A calibr~lio" screw 152 is threaded into a threaded aperture 154 formed in a central boss 156 of upper valve housing 26 and which supports a second spring retainer 158 thereon. A helical coil spring 160 is ce~ Ittdlly disposed within re~erence "~ 2157717 Attorney Docket: 1203~0081 chamber 108 of control chamber 90 and is retained between the aligned spring retainers 150 and 158 for exe~ y a biasing force on .lia~l ,ragm valve assembly 92 such that poppet-type closure member 146 is normally biased against valve seat 148 for inhibiting flow through vacuum regulator valve 14.
When the engine of a vehicle equipped with vapor management valve 10 is not in o~.erdlio" EVR valve 12 is not e~,eryi~ed (i.e. 0% duty cycle) such that armature 46 is urged by gravity and atmospheric air to the "open" valve positionr~-ced from seated e"gagement with valve seat member 48 for engagement with an upper planar surface of cup member 84. Moreover in the absence of manifold vacuum 104 being applied to conlrol chamber 90 via p~s~ge 100 and flow-te~ll icLi~/e orifice 102 the preload of coil spring 160 urges diaphragm valve assel,lt,ly 92 downward to cause closure menlLer 146 to seat a~c.i.lsl valve seat 148. In this con.litiGI I flow of fuel vapors from valve chamber 94 to outlet port 142 is inhibited.
However when the vehicle is in G~ eralion a vacuum pressure is intro~iuced into control chamber 90 through vacuum inlet p~cs~ge 100 and flow-restrictive orifice 102 ll,ereL,y tending to maintain armature 46 in the "open" valve position. Concurrently air flow from the aLmosphere 40 is drawn through the plurality of apertures 42 formed in filter cover 28 and through anti-permeation filter assembly 44 and particularly through the layer of a-lsor~ti~e material 45 and p~sses into air inlet 38. The air flow then enters EVR chamber 82 for generaLi,ly a control vacuum signal within control chamber 90 which is a controlled portion of the manifold vacuum 104 supplied at inlet ra~s~ge 100. As is known energi~tion of solenoid assembly 24 of EVR valve 12 in Attorney Docket: 1203 00081 response to the control signal sll~pliQd by engine control unit ("ECU") 22 is operable for exerting a magnetic attractive force between armature 46 and pole piece 34 in orrosition to the effect of the vacuum pressure from manifold vacuum 104 Thus, the amount of vacuum, and hence the "vacuum signal" provided to control chamber 90 of vacuum reg~ tor valve 14 is cGnlrc"ed by the degree to which armature 46 is attracted toward valve seat 48. In particular, the magnitude of the magnetic attractive force exerted on armature 46 is equal to the product of the vacuum pressure in EVR
ol ,a, ~ Iber 82 multiplied by the cross-sectional area of armature 46. In addition, the flow resl,i~tio" from air inlet 38 to EVR chamber 82 results in a pressure drop proportional to the magnetic force applied to armature 46. Therefore, as the magnetic attraction exerted on armature 46 i"creases, the level of vacuum pressure in EVR chamber 82also increases. Similarly, as the magnetic attraction force exerted on armature 46 decreases, the level of vacuum pressure in EVR chamber 82 also decreases. Thus, the ,uerce"lage duty c,vcle of the electrical col llrol signal sl,, ' E'i to EVR valve 12 from ECU 22 co,lt,ols the "vacuum signal" provided to the referei,ce side of vacuum reg~ or valve 14.
Vacuum regulator valve 14 is shown to include a defuser ring 162 which s~yl eydles valve chamber 94 into a lower ~. recl ,amL,er 164 communicating with inlet ~Ass~gervay 130 via inlet orifice 140, and an upper chamber 166 which is locatedabove defuser ring 162 and which commu":~etes with exit tube 142. In addition, defuser ring 162 has a series of equally-space radial orifices 168 for permitting communication between prechamber 164 and upper chamber 166.
Attorney Docket: 1203 00081 As vapors from canister 18 travel through the inlet p~s~eway 130 and enter valve chamber 94 via inlet orifice 140 the vapor concenlralion within valve cl,a",ber 94 is yraalerthan the conce~lraLio~ in co~lrol chamber 90. This di~arence in concenlr~liG" creales a condilio,) in which the vapors permeate diaphragm 5 , ne" ,bra,)e 138 and pass into control chamber 90. Once the vapors are within control cl ,a,nL,er 90 they are free to communicate with air inlet 38 since as previously stated armature 46 is not seated against valve seat member 48 and the vapors may travel through center bore 36 into air inlet 38 and thus allen~pl to ~niyrale through anti-permeation filter assembly 44. However the intermolecular attractive forces of 10 adsor,uli./e male,ial 45 located within anti-permeation filter assel"bly 44 cause the vapors to al.sGrb (or condense) on its surface. This adsGr~.lion prevents the vapor from being el "illad into atmosphere 40 via the plurality of apertures 42 formed in filter cover 28.
The adsorbed vapors are rele~serl from a.lsGr~ /e material 45 when the 15 engine of the vehicle equipped with vapor manayemenl valve 10 is put in an operating condition. As manifold vacuum 104 lowers the pressure in control chamber 90 the combination of decreased pressure and air flowing across adsorptive malerial 45 from ~d "os~l ,ere 40 the intermla'ec~ attractive forces are overcome and the fuel vapors are drawn into air inlet 38. From air inlet 38 the fuel vapors are drawn through center 20 bore 36 past the plurality of radially-sp~ce~l notches in armature 46 and into EVR
cl ,al, ll.er 82. Once in EVR chamber 82 the fuel vapors travel through orifices 105 and 120 into control chamber 90. From control chamber 90 the fuel vapors are drawn Attorney Docket: 1203 00081 through restrictive orifice 102 into pass~ge 100 provided in nipple connection 98.
Finally the fuel vapors in nipple connection 98 are drawn into the manifold via suitable tubing (not shown) for sl ~hselluent combustion.
In accordance with an all~r"ali~e pre~erred embodiment shown in FIG.
5 2 the layer of ad~or,)li./e " ,alerial is shown in the form of an annular filter ring 170 that has replnce~l damping ring 110 of FIG. 1. More particularly adso". li~/e filter ring 170 is retained between outer wall portion 114 and inner wall portion 116 of upper housing 26 for segregating damping chamber 106 from reference chamber 108. In operation annular adsorptive filter ring 170 attenuates fluctuations in the vacuum signal supplied 10 by vacuum regulator valve 14 upon actuation of EVR valve 12 to inhibit oscillation of dia~l ,ragm valve asse" Ibly 92. It will be a~preciated that vapor management valve 10 of the present invention could also be equipped with adsor,~ti~re filter ring 170 in combination with filter asse"ll,ly 44 if a particular application w~lldl)ls such use.
The foregoing ~isc~lscion ~isclQses and desc~ibes merely exemplary 15 embodiments of the present invention. One skilled in the art will readily recognize from such fliscl ~-ssion and from the acco",panying drawings and claims that various changes modificalions and varidlio"s can be made therein without departing from the spirit and scope of the invention as defined in the following claims.
BACKGROUND OF THE INVENTION
The ~rese~l invention relates ~e~erally to elec~on ally-co"l,ùlled flow reg~ tors of the type used in aulumoli~/e vehicles equipped with computer-conl~olled er"ission control systems.
As is known virtually all modern automotive vehicles are equipped with emission control systems that are operable for limiting the eu lission of hydrocarbons into the atmosphere. Such emission control systems typically include an eva~.orali~re emission control system which traps fuel vapors from the fuel tank in a carbon filled can;sler and a purge system which draws the vapors from the canisler into the engine intake system. In this rllallller~ fuel vapors from the fuel tank are delivered into the engine for suhseq~ ~ent combustion.
Conve"lional eva,uoralive e",issiol, control systems are equipped with elec~o"-cally controlled purge valves for regulating the flow rate of fuel vapors introrl~ ~ce~ into the intake system in response to specific engine operating parameters.
Conventional purge valves col",urise pulse width modul~tion (PWM) solenoid valves which are res~.ol,sive to a duty cycle control signal from the engine computer.
However PWM purge valves provide uneven flow characteristics particularly at lowengine speeds and also do not provide consislent flow control independent of valicliolls in manifold vacuum.
In view of increasingly stringent emission regulations the demands on the evaporative e"l.ssioll control system have increased dramalically. In particular in order to satisfy current EPA emission requirements the flow capability of the Attorney Docket: 120~00081 evaporative e" ,;ssion system must be increased. To achieve this result within the EPA
city test cycle, it is thererore necessa~ ~ to provide purge flow at engine idle speeds.
Moreover, purge flow control must also be accurately regulated so as not to cause cce~ hle excursions in overall engine output emissions.
To provide such enhanced flow control, it is desirable to have the output flow cl,aracteri~lics of the purge valve be ,~.,o,uo,lional to the duty cycle of the electronic control signal applied to the valve, even at low engine speeds, and yet be independent of variations in the manifold vacuum. Accordingly, the output flow of the valve should be sub~ldl~lially constant at a given duty cycle control signal and be co"ltc"-'~le in response to regul~te~ changes in the duty cycle regardless of va, ialio"s in manifold vacuum. Moreover, it is also desirable that the output flow of the valve vary s~ sl~, Itially linearly from a preddle,I~lined "minimum" flow rate at a "start-to-open" duty cycle to a specified "~"axi"lum" flow rate at 100% duty cycle.
The above performance ~el "a"ds have prompted the recent dcvclo~.",ent of a purge flow regulator that combines an electric vacuum regulator (EVR) solenoid valve with a diaphragm-type vacuum regulator valve to provide thedesired continuous controlled flow characteri~lics independent of variations in manifold vacuum. In particular, the EVR solenoid valve is connected to the diaphragm vacuum regulator valve so as to regulate the vacuum signal supplied to the reference side of the dia~h~agm valve in accorda"ce with the control signal from the engine computer.
A closure member, associated with the opposite side of the diaphragm, co, llrols flow from the input port to the output port of the vacuum regulator valve in response to 215 7 717 Attorney Docket: 1203-00081 regulated movement of the diaphragm. Since the EVR valve is in communication with aLmos~here and a vacuum source, such as the intake manifold of the engine, the amount of vacuum (i.e., the vacuum signal) provided to the reference side of the dia, ~l "agm is proportional to the electric control signal supplied to the EVRvalve by 5 the on-board engine control computer. Thus, output flow through the vacuum reg~ ~Iqtor valve is controlled by the duty cycle of the control signal applied to the EVR
valve.
Examples of ele~onically controlled flow purge regulators of this type are Iisclosed in U.S. Pat. No. 4,534,378 to Cook and U.S. Pat. No. 5,050,568 to Fox.
10 However, for such conventional flow regulators to satisfy the above-described ~e,~"na,1ce specilicalions, the purge flow regul~tor must be precisely calibrated. It has been ,urol ~ose~ I to calibrate the purge flow regul -tor by adjusting the characteri~lics of the EVR solenoid valve. In particular, the preload on the armature bias spring of the EVR valve is adjusted for setting the minimum flow rate at the "start-15 to-open" duty cycle. Such changes in the magnitude of preload on the armature bias spring effectively ~ rlaces the pe,ru""ance curve without changing its slope. In ition, the reluctance of the solenoid flux path is adjusted for setting the n ,axi" ~um flow rate at the 100% duty cycle. However, changes in reluctance result in a cor~s~,onding change in the slope of the pel ror"~a"ce curve. As can be appreci~te~l, 20 this calibration alJproach is problematic in that each adjustment affects the other, such that the two calibration adjustments are depen-lel ll and cumulative in nature. As such, it typically requires several iterations to "zero-in" on both of the desired calibration Attorney Docket: 120~00081 points. Accordi. Igly while such conventional flow regulators are generally successful in automotive emission control systems for their intended purpose there is a continuing need to develop alle",alives which meet the above-noted performance specifications and can be manuf~ctl~red and calibrated in a more erricia"l and cost 5 effective "~anner.
In view of the above an improved vapor management valve was dcveloped which combines an EVR valve and a vacuum regulator valve for generating an output flow characieri~lic that is ~,rol ollional to the duty cycle of the electrical control signal and yet is independent of variations in manirold vacuum this vapor management valve being disclosed in commonly-owned U.S. Pat. No. 5277167 issued to DeLand et al. Upon continued dcv~lo,u,llent of this commercially-successful vapor manayen ,e, ll valve it was discovered that fuel vapor can per" ,eale through the flexible dia~l "agm mer~lbrane particularly when the system is inactive. Accordingly in an effort to provide further gains in emission control an anti-permeation filter has been developed with adsGr,uli~/e ,uro,ue, lies which prevents the fuel vapors from being vented to the atmos,vhere. During normal oper~lion of the vapor management valve the adsorbed vapors are extracted from the anti-permeation filter by the inlet air flow and are delivered to the engine for subse~uent combustion.
SUMMARY OF THE INVENTION
Accordingly it is the primary object of the present invention to provide a modified version of the vapor management valve disclosed in commonly owned U.S.
`~ 21S7717 - Attorney Docket: 1203 00081 Patent No. 5 277 167 which has means for coull olling the vapors which may otherwise pe" nedle the dia,cl ,ragm and be vented to the almosphere. Particularly the present invention provides a means of adsorbing fuel vapors which permeate the dia,c)h, agm and later during normal operalion releasi"y the adsorbed vapors into the flow of air ,uassi, Iy into the intake ~ 1 lani~dld.
Ad.litio. ,al objects and ad~a, Itdyes of the present invention will become a~.t.arent from a reading of the following detailed desc-i~Lion of the ~refer,~dembodiment taken in conjunction with the acco,,,,uanyin9 drawings and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a se~ional view of an ele_t,on-~qlly-controlled flow regulator shown Jiay- ~rr ma~ically ~ssoc; ~ . I with an ev~,uord~ e em;ssiol1s control system and equipped with an anti-per"lealion filter according to a first ~,reret,ed embodiment of the ,uresenl invention; and FIG. 2 is a view similar to Fig. 1 showing an aller,lalive location for the anti-per")ea~io" filter of the ~rese, ll invention.
DESCRIPTION OF THE l Ht~t~RED EMBODIMENT
In yeneral the present invention is directed to a modified construction for the vapor management valYe disclosed in com~only owned U.S. Patent No.
5 277 167to DeLand et al. However to provide a basic understanding of the structure of the vapor management _ 2157717 Attorney Docket: 1203 00081 valve as it relates to the present invention the following structural overview is provided.
Thus a preferred embodiment of an electronically-conlrolled flow regulator is disclosed which is ada~.~e.l for use in an evdporali~e emissio~ control system for purging fuel vapors collected in a charcoal canisler into the intake system of the vehicle s internal 5 combustion engine. However it will be readily appare"l that the improved flow regul?tor has utility in other vehicular flow controlling applications.
In the drawings wherein for purposes of illustration is shown a pre~r~ad embodiment of a vapor manageme,1l valve incor,uor~li"g the present invention ele~Lronically controlled flow regl~l~tor 10 is lisclosed as having an elec~,ol1ically-10 ~ctu~ted vacuum regulator ("EVR") valve 12 and a vacuum regulator valve 14. By wayof example flow regulator 10 is shown as a vapor management valve of the type ~csoci ~e~ with a conve"liol ,al evaporali~/e e" lissiG" control system for an auLo,noli~/e vehicle. More specifically fuel vapors vented from a fuel tank 16 are cc"Qcted in a cl ,arcoal ca";~lar 18 and are controllably purged by vapor management valve 10 into 1~ the intake system 20 (i.e. the intake manifold) of the vehicles i~Ler"al combustion engine in response to electrical COI Illol signals sl Irrlie~ to EVR valve 12 by a remote engine controller unit ("ECU") 22. While EVR valve 12 and vacuum regulator 14 are shown assel, Ibled as a unitary flow regula~or 10 it is to be understood that the valves could be se,uarate components that are i"Lerco""ected by suitable tube connections 20 in a known manner.
As seen in FIG. 1 EVR valve 12 is an encarslJl~te~i solenoid assembly 24 secured to an upper valve housing 26 of vacuum regulator valve 14 having a filter Attorney Docket: 1203 00081 cover 28 removably connected to a top portion thereof. Solenoid assembly 24 inclu~les a bobbin 30 ral.ricaled from a non-magnetic nylon-tape material having a plurality of coil windings 32 wound thereon. The ends of coil winding 32 are elect,ically connected to a pair of terminal blades 33. A magnetic pole piece 34 5 eAlen.ls through a hollow central core of bobbin 30 and in turn has a central bore 36 formed therein which serves as an air r~ss~eway which communicates with an air inlet 38. Al" ,os,uheric air identified by block 40 is admitted into air inlet 38 through a plurality of apertures 42 formed in filter cover 28 and is filtered by an anti-permeation filter assembly 44 located inside filter cover 28. The anti-permeation filter assembly 44 10 contains a layer of a SlliP~'Q adsorptive ~alerial 45 such as for example activated c:l,alcoal that is sandwashed between two layers 47 of a di~rerent porous filtering mal~:rial. The l~iscl ,arge of atmospheric air from the l,uLlum of central bore 36 in pole piece 34 is controlled by a flat disk-type magnetic armature 48 which is adapted to seat against a non-magnetic valve seat member 48 that is fixed to a lower end of pole piece 34. The valve seat member 48 has a central bore 50 formed therein having a diameter s~ sl~-,lially equal to the o~tsirle diameter of pole piece 34. The lower .ullio,, of valve seat member 48 has a radially enlaryed annular flange 52 which acco"~,oodates a shallow col"~le,rorce 54 formed in a bottom face 56 of valve seat member 48. The resulting annular-shaped bottom face 56 defines a valve seat and 20 is prere(ably ll,acllil led with a slight radial back taper to provide a circular "line" seal with flat disk armature 46.
` 2157717 Attorney Docket: 1203-00081 During asse" ,l,ly valve seat member 48 is installed on the lower end of pole piece 34 in a fixture that automatically sets the axial position of valve seat surface 56 relative to an end face 58 of pole piece 34. More specifically when pole piece 34 is inserted into bore 50 a slightly oversized knurled region 60 of pole piece 34 5 embeds in the inner wall of valve seat bore 50 to create a tight frictional engagement between the two components. This is ;~ JG~ since the axial distance between end face 58 of pole piece 34 and seat surface 56 of valve seat member 48 defines the ,urinlary or working air gap between pole piece 34 and armature 46 in the "closed"
valve ~.osilio, l when EVR valve 12 is fully assembled.
10Surrounding the top end of pole piece 34 is an annular-shaped magnetic flux c~l'ector ring 62 that is co""euted to a magnetic L-frame member 64. L-frame ",e"~Ler 64 ino~ es an annular-shaped lower seymenl 66 that surrounds armature 46. Thus when solenoid assembly 24 is e"eryi~ed by current flow through coil winding 32 the magnetic flux path is ~l~i"ed by pole piece 34 armature 46 L-frame 15member 64 and flux collector ring 62. The combined pole piece 34 in valve seat ",enlL,er 48 sub-asse"lbly is shown inserted into an enlaryed bore section 68 of bobbin 30 until the top end of pole piece 34 is suL,sta"lially flush with the top surface of flux collector ring 62. A ~ tionally bond valve seat member 48 within bore section 68 of bobbin 30 ridge-like bars 70 ror",ed on the outer wall surface of valve member 20 48 embed on or "bite" into the inner wall surface of bore 68 to resist withdrawal ther~,o",. In addition the tight seal formed between bobbin 30 and valve seat Attorney Docket: ~20~ Q0081 m~"~Ler 48 serves to inhibit leakage of atmospheric air from air inlet 38 around the o~ e of seat member 48.
Flux e~"e~tor ring 62 is installed on the top of bobbin 30 and L-frame .nember 64 is installed with lower segment 66 thereof place over the bottom of tlobt n 5 30. L-frame member 64 has a pair of depending tabs (not shown) which are adapted to mate with corles~.G"ding recesses formed on oprosite sides of flux collector ring 62 for mechanically joining the two components. With the magnetic segments joined to wound bobbin 30 the entire sub-assei,lbly is encaps~ ted in an injection mode which forms a housing 72 for solenoid asse"lL,ly 24. The injection molding process 10 completely e"closes and seals solenoid asse~,lL,ly 24 while simultaneously forming a plug-in rece~ cle 74 e n~losi,1y terminal blades a mounting flange 76 for filter cover 28 and a lower connecting flange 78 for mating with upper valve housing 26.
The lower connecting flange 78 of housing 72 for solenoid asse"lbly 24 is shown retained and sealed within e,xle" ~al cavity 80 formed in upper valve housing 15 26. Moreover the circular-shaped cavity defined by the inner diameter of lower coi.ne~iny flange 78 of solenoid housing 72 defines an EVR chamber 82 below armature 46 that selectively communicates with air inlet 38 via central bore 36. A non-magnetic cup sl ,a~.ed member 84 is ,1i51 ose- I within EVR chamber 82 for s~ o, li~1g armature 46 in an "open" valve position (FIG.1) ~isplnce~ from valve seat member 48.
20 The inside ~lia"~eter of EVR chamber 82 is slightly grealer than the diameter of armature 46 to permit axial movement yet confine lateral movement of armature 46 therein. To facilildle air flow around the periphery of armature 46 when it is displaced Attorney Docket: 1203~0081 from sealed engagement (i.e. the "closed" valve position) with valve seat member 48 armature 46 has a plurality of radially-sr~ce~l notches 86 formed along its peripheral edge and cup member 84 has a plurality of slots 88 formed therein for providing a communication pathway between pole piece central bore 36 and EVR chamber 82.
With continued reference to FIG.1 vacuum regulator valve 14 is shown as a vacuum-operable dia,.~l "agm valve having a control chamber 90 formed within upper housing 26 and above a movable dia,vl ,r~gm valve asse~llLly 92 and a valve chamber 94 formed within a lower housing 86 below diaphragm valve assembly 92.
In a~ tion a vacuum inlet shown as nippled col,l,e~;lor 98 is formed in upper housing 26 and has a r~ss~ge 100 which comml",icales with col)lrol chamber 90 through a flow-reslric~i~re orffice 102. Nippled connector 98 is adapted for connection via suitable tubing (not shown) to a vacuum signal source r~arnely manifold vacuum for the intake "~a"i~. d of the engine idenli~ied by block 104. Moreover controlchamber 90 communicates with EVR chamber 82 via an orifice 105 formed in the L.ullo, n of exler~ ,al cavity 80 such that the vacuum signal (negative pressure) delivered to control chamber 90 from EVR valve 12 is a co"lrolla.l portion of the vacuum input at connector 98 as determined by the eleullical control signal supplied by ECU 22 to windings 32 of solenoid asse" ~LIy 24. Aller"dli~ely it is conle" ,,ulaled that the vacuum inlet could be posiliol ,ecJ to communicate directly with EVR cl ,~mber 82.
Control cl,an-lL,er 90 is divided into two distinct portions namely an attenuation or "damping" chamber 106 and a referel,ce chamber 108 by a damping ring 110. In s~eneral damping chamber 106 is located intermediate to EVR chamber Attorney Docket: 1203~0081 82 and rerere"ce chan,ber 108 and is operable for attenuating fluctuations in the vacuum signal sl ~pr'i~ed to rerere"ce chamber 108 and diaphragm valve assembly 92 upon actuation of E~VR valve 12. More particularly damping ring 110 is an annular "emL,er which is retained between an outer wail portion 114 and an inner wall portion 116 of upper housing 26 for sey,eya~ y dalll,ui,ly chamber 106 from reference chamber 108. Damping chamber 106 is located above damping ring 110 while reference chamber 108 is loc~te~i below damping ring 110 and includes a central cavity 118 defined by circular inner wall portion 116 so as to act over the entire top surface of .Jia~l"agm valve asse",bly 92. One or more damping orifices 120 are formed in ~lal l l,uing ring 110 to attenuate fl~ ~ctu~tions in the vacuum signal supplied to vacuum regulator valve 14 upon ~ tion of EVR valve 12 which in turn inhibits ~",desirable oscillation (i.e. 'flutter") of dia~ l,ragm valve assembly 92. Mores~.ecifically since ECU 22 surr' es a sawtooth waveform ,urererably at about 100 Hz to drive solenoid asser,lbly 24 of E~VR valve 12 direct ar.l lic liol1 of the vacuum signal 1 ~ in EVR c;l ,amLer 82 to diapl1ray"~ valve asse~ ~ Ibly 92 in control chamber 90 may cause dia,.~l,rag,n valve asse"lL,ly 92 to osc~ te. Thus it is desirable to isolate diaphragm valve assembly 92 from the 100 Hz vacuum fll ~ctl l~tion by providing .lal l l~ing chamber 106 with a larger volume than EVR cl ,a" Iber 82 for effectively reducing the magnitude of any pressure fluctu~tions. In addition damping orifice 120 is sized to provide the amount of resl,i~i~/e flow necessa~y to bala~ce the vacuum pressure between .J~II~J-n9 chamber 106 and rererence chamber 108 such that a balanced vacuum is Attorney Docket: 1203~0081 established in control chamber 90 that matches the vacuum signal in EVR chamber 82.
To provide means for regulating the purge flow of fuel vapors from can;sler 18 in the engine s intake system 20 lower housing 96 of vacuum reg~ torvalve 14 inc~u~les a nippled inlet coi "~e~or 128 adapted for connecting inlet pA~s~geway 130 to canisler 18 via suitable tubing (not shown) and a nippled outlet connector 132 adapted for connecting outlet p~cs~-Jeway 134 to intake manHold 20of the engine. Vacuum-~ctu~te~ dia,, l ,ragm valve assembly 92 is comprised of a rigid piston 136 and a flexible diaphragm 138 that are retained between valve housings 26 and 96 for co, lltolle.l axial movement to regulate the purged flow from canister 18 and inlet p~-ss~geway 130 to outlet p~-ss~geway 134 in the engine s intake manifold 20.
In addition inlet l ~ss~-Je~/vay 130 comm~ tes with valve chamber 94 via inlet orifice 140. Valve cl ,ari Iber 94 is adapted to selectively communicate with outlet ~ ~cs~geway 134 via an exit tube 142 in res~onse to the axial movement of a ,uop~.el-type closure member 146 in a direction away from an annular valve seat 148 formed at one end of exit tube 142.
Poppet-type closure member 146 is integrally associaled with an underside portion of dia,.~l ,r~y", valve asse"lL,ly 92 while the upper side of diapl ,r~y", valve assembly 92 inc~ QS a first spring retainer 150 which is preferably inley, al with piston 136. A calibr~lio" screw 152 is threaded into a threaded aperture 154 formed in a central boss 156 of upper valve housing 26 and which supports a second spring retainer 158 thereon. A helical coil spring 160 is ce~ Ittdlly disposed within re~erence "~ 2157717 Attorney Docket: 1203~0081 chamber 108 of control chamber 90 and is retained between the aligned spring retainers 150 and 158 for exe~ y a biasing force on .lia~l ,ragm valve assembly 92 such that poppet-type closure member 146 is normally biased against valve seat 148 for inhibiting flow through vacuum regulator valve 14.
When the engine of a vehicle equipped with vapor management valve 10 is not in o~.erdlio" EVR valve 12 is not e~,eryi~ed (i.e. 0% duty cycle) such that armature 46 is urged by gravity and atmospheric air to the "open" valve positionr~-ced from seated e"gagement with valve seat member 48 for engagement with an upper planar surface of cup member 84. Moreover in the absence of manifold vacuum 104 being applied to conlrol chamber 90 via p~s~ge 100 and flow-te~ll icLi~/e orifice 102 the preload of coil spring 160 urges diaphragm valve assel,lt,ly 92 downward to cause closure menlLer 146 to seat a~c.i.lsl valve seat 148. In this con.litiGI I flow of fuel vapors from valve chamber 94 to outlet port 142 is inhibited.
However when the vehicle is in G~ eralion a vacuum pressure is intro~iuced into control chamber 90 through vacuum inlet p~cs~ge 100 and flow-restrictive orifice 102 ll,ereL,y tending to maintain armature 46 in the "open" valve position. Concurrently air flow from the aLmosphere 40 is drawn through the plurality of apertures 42 formed in filter cover 28 and through anti-permeation filter assembly 44 and particularly through the layer of a-lsor~ti~e material 45 and p~sses into air inlet 38. The air flow then enters EVR chamber 82 for generaLi,ly a control vacuum signal within control chamber 90 which is a controlled portion of the manifold vacuum 104 supplied at inlet ra~s~ge 100. As is known energi~tion of solenoid assembly 24 of EVR valve 12 in Attorney Docket: 1203 00081 response to the control signal sll~pliQd by engine control unit ("ECU") 22 is operable for exerting a magnetic attractive force between armature 46 and pole piece 34 in orrosition to the effect of the vacuum pressure from manifold vacuum 104 Thus, the amount of vacuum, and hence the "vacuum signal" provided to control chamber 90 of vacuum reg~ tor valve 14 is cGnlrc"ed by the degree to which armature 46 is attracted toward valve seat 48. In particular, the magnitude of the magnetic attractive force exerted on armature 46 is equal to the product of the vacuum pressure in EVR
ol ,a, ~ Iber 82 multiplied by the cross-sectional area of armature 46. In addition, the flow resl,i~tio" from air inlet 38 to EVR chamber 82 results in a pressure drop proportional to the magnetic force applied to armature 46. Therefore, as the magnetic attraction exerted on armature 46 i"creases, the level of vacuum pressure in EVR chamber 82also increases. Similarly, as the magnetic attraction force exerted on armature 46 decreases, the level of vacuum pressure in EVR chamber 82 also decreases. Thus, the ,uerce"lage duty c,vcle of the electrical col llrol signal sl,, ' E'i to EVR valve 12 from ECU 22 co,lt,ols the "vacuum signal" provided to the referei,ce side of vacuum reg~ or valve 14.
Vacuum regulator valve 14 is shown to include a defuser ring 162 which s~yl eydles valve chamber 94 into a lower ~. recl ,amL,er 164 communicating with inlet ~Ass~gervay 130 via inlet orifice 140, and an upper chamber 166 which is locatedabove defuser ring 162 and which commu":~etes with exit tube 142. In addition, defuser ring 162 has a series of equally-space radial orifices 168 for permitting communication between prechamber 164 and upper chamber 166.
Attorney Docket: 1203 00081 As vapors from canister 18 travel through the inlet p~s~eway 130 and enter valve chamber 94 via inlet orifice 140 the vapor concenlralion within valve cl,a",ber 94 is yraalerthan the conce~lraLio~ in co~lrol chamber 90. This di~arence in concenlr~liG" creales a condilio,) in which the vapors permeate diaphragm 5 , ne" ,bra,)e 138 and pass into control chamber 90. Once the vapors are within control cl ,a,nL,er 90 they are free to communicate with air inlet 38 since as previously stated armature 46 is not seated against valve seat member 48 and the vapors may travel through center bore 36 into air inlet 38 and thus allen~pl to ~niyrale through anti-permeation filter assembly 44. However the intermolecular attractive forces of 10 adsor,uli./e male,ial 45 located within anti-permeation filter assel"bly 44 cause the vapors to al.sGrb (or condense) on its surface. This adsGr~.lion prevents the vapor from being el "illad into atmosphere 40 via the plurality of apertures 42 formed in filter cover 28.
The adsorbed vapors are rele~serl from a.lsGr~ /e material 45 when the 15 engine of the vehicle equipped with vapor manayemenl valve 10 is put in an operating condition. As manifold vacuum 104 lowers the pressure in control chamber 90 the combination of decreased pressure and air flowing across adsorptive malerial 45 from ~d "os~l ,ere 40 the intermla'ec~ attractive forces are overcome and the fuel vapors are drawn into air inlet 38. From air inlet 38 the fuel vapors are drawn through center 20 bore 36 past the plurality of radially-sp~ce~l notches in armature 46 and into EVR
cl ,al, ll.er 82. Once in EVR chamber 82 the fuel vapors travel through orifices 105 and 120 into control chamber 90. From control chamber 90 the fuel vapors are drawn Attorney Docket: 1203 00081 through restrictive orifice 102 into pass~ge 100 provided in nipple connection 98.
Finally the fuel vapors in nipple connection 98 are drawn into the manifold via suitable tubing (not shown) for sl ~hselluent combustion.
In accordance with an all~r"ali~e pre~erred embodiment shown in FIG.
5 2 the layer of ad~or,)li./e " ,alerial is shown in the form of an annular filter ring 170 that has replnce~l damping ring 110 of FIG. 1. More particularly adso". li~/e filter ring 170 is retained between outer wall portion 114 and inner wall portion 116 of upper housing 26 for segregating damping chamber 106 from reference chamber 108. In operation annular adsorptive filter ring 170 attenuates fluctuations in the vacuum signal supplied 10 by vacuum regulator valve 14 upon actuation of EVR valve 12 to inhibit oscillation of dia~l ,ragm valve asse" Ibly 92. It will be a~preciated that vapor management valve 10 of the present invention could also be equipped with adsor,~ti~re filter ring 170 in combination with filter asse"ll,ly 44 if a particular application w~lldl)ls such use.
The foregoing ~isc~lscion ~isclQses and desc~ibes merely exemplary 15 embodiments of the present invention. One skilled in the art will readily recognize from such fliscl ~-ssion and from the acco",panying drawings and claims that various changes modificalions and varidlio"s can be made therein without departing from the spirit and scope of the invention as defined in the following claims.
Claims (12)
1. A flow regulator for controlling the purging of fuel vapors collected in a canister of an evaporative emission control system into an intake system of an internal combustion engine, said flow regulator comprising:
a first valve having a vacuum inlet in communication with a vacuum source of the intake system and means for generating a vacuum signal that is a percentage of the vacuum received at said vacuum inlet in response to an electrical control signal;
a second valve having a first chamber in communication with said vacuum signal, a second chamber, a diaphragm valve retained for movement between said first and second chambers, inlet means connecting the canister for communication with said second chamber, outlet means communicating with the engine intake system, closure means for controlling flow between said inlet means and said outlet means in response to movement of said diaphragm valve, biasing means acting on said diaphragm valve for inhibiting flow between said inlet means and said outlet means, first calibration means for varying the biasing force exerted by said biasing means on said diaphragm valve for setting a first flow rate limit, and second calibration means for varying the flow in said inlet means to set a second flow rate limit, said flow regulator operable to generate substantially linear flow between said first and second flow rate limits as a function of the value of said control signal and independent of variations in the magnitude of the vacuum supplied to said vacuum inlet by said vacuum source; and a filter capable of capturing fuel vapors which have permeated-through said diaphragm valve and which is further capable of releasing the captured vapors during normal operation of said flow regulator and allowing the released vapors to be drawn into the intake system of the internal combustion engine for subsequent combustion.
a first valve having a vacuum inlet in communication with a vacuum source of the intake system and means for generating a vacuum signal that is a percentage of the vacuum received at said vacuum inlet in response to an electrical control signal;
a second valve having a first chamber in communication with said vacuum signal, a second chamber, a diaphragm valve retained for movement between said first and second chambers, inlet means connecting the canister for communication with said second chamber, outlet means communicating with the engine intake system, closure means for controlling flow between said inlet means and said outlet means in response to movement of said diaphragm valve, biasing means acting on said diaphragm valve for inhibiting flow between said inlet means and said outlet means, first calibration means for varying the biasing force exerted by said biasing means on said diaphragm valve for setting a first flow rate limit, and second calibration means for varying the flow in said inlet means to set a second flow rate limit, said flow regulator operable to generate substantially linear flow between said first and second flow rate limits as a function of the value of said control signal and independent of variations in the magnitude of the vacuum supplied to said vacuum inlet by said vacuum source; and a filter capable of capturing fuel vapors which have permeated-through said diaphragm valve and which is further capable of releasing the captured vapors during normal operation of said flow regulator and allowing the released vapors to be drawn into the intake system of the internal combustion engine for subsequent combustion.
2. The flow regulator of Claim 1 wherein said first valve is an electric vacuum regulator valve and said means for generating said vacuum signal includes an electromagnetic solenoid assembly having a passageway communicating with atmosphere an EVR chamber communicating with said vacuum inlet a magnetic flux path including a magnetic armature member and means for establishing the flow of electromagnetic flux through said flux path said magnetic armature being movable for controlling flow through said passageway in response to the magnitude of said electric control signal supplied to said means for establishing flow of electromagnetic flux and said filter is located between said passageway and atmosphere.
3. The flow regulator of Claim 2 wherein said filter includes a layer of adsorptive material for preventing fuel vapors in said passageway from being vented to amosphere.
4. The flow regulator of Claim 1 wherein said filter is an annular filter ring made of an adsorptive material said filter ring being retained between said first and second chambers for absorbing fuel vapors permeating through said diaphragm valve.
5. A flow regulator for controlling the purging of fuel vapors collected in a canister of an evaporative emission control system into an intake system of an internal combustion engine comprising.
a first valve having a vacuum inlet connected to a vacuum source a first chamber in communication with said vacuum inlet a second chamber a pressure-operable diaphragm valve retained for movement between said first and second chambers inlet means connecting the canister for communication with said second chamber outlet means communicating with the engine intake system such that movement of said diaphragm valve is operable for controlling flow between said inlet means and said outlet means biasing means acting on said diaphragm valve for biasing said diaphragm valve to inhibit flow between said inlet means and said outlet means first calibration means for varying the biasing force exerted by said biasing means on said diaphragm valve for setting a first flow rate value and second calibration means for varying the flow in said inlet means to set a second flow rate value;
a second valve in communication with said first chamber of said first valve and having electrically-controllable means for generating a vacuum signal as a percentage of the vacuum pressure received at said vacuum inlet in response to an electrical control signal said vacuum signal being controllably regulated for generating substantially linear flow between said first and second flow rate values as a function of the magnitude of said electrical control signal and independent of variations in said vacuum pressure supplied to said vacuum inlet by said vacuum source; and a filter capable of capturing fuel vapors which have permeated said diaphragm valve and which is further capable of releasing the captured vapors during normal operation of said flow regulator and allowing the released vapors to be drawn into the intake system of the internal combustion engine for subsequent combustion.
a first valve having a vacuum inlet connected to a vacuum source a first chamber in communication with said vacuum inlet a second chamber a pressure-operable diaphragm valve retained for movement between said first and second chambers inlet means connecting the canister for communication with said second chamber outlet means communicating with the engine intake system such that movement of said diaphragm valve is operable for controlling flow between said inlet means and said outlet means biasing means acting on said diaphragm valve for biasing said diaphragm valve to inhibit flow between said inlet means and said outlet means first calibration means for varying the biasing force exerted by said biasing means on said diaphragm valve for setting a first flow rate value and second calibration means for varying the flow in said inlet means to set a second flow rate value;
a second valve in communication with said first chamber of said first valve and having electrically-controllable means for generating a vacuum signal as a percentage of the vacuum pressure received at said vacuum inlet in response to an electrical control signal said vacuum signal being controllably regulated for generating substantially linear flow between said first and second flow rate values as a function of the magnitude of said electrical control signal and independent of variations in said vacuum pressure supplied to said vacuum inlet by said vacuum source; and a filter capable of capturing fuel vapors which have permeated said diaphragm valve and which is further capable of releasing the captured vapors during normal operation of said flow regulator and allowing the released vapors to be drawn into the intake system of the internal combustion engine for subsequent combustion.
6. The flow regulator of Claim 5 wherein said first valve is an electric vacuum regulator valve and said means for generating said vacuum signal includes an electromagnetic solenoid assembly having a passageway communicating with atmosphere, an EVR chamber communicating with said vacuum inlet a magnetic flux path including a magnetic armature member and means for establishing the flow of electromagnetic flux through said flux path said magnetic armature being movable for controlling flow through said passageway in response to the magnitude of said electric control signal supplied to said means for establishing flow of electromagnetic flux and said filter is located between said passageway and atmosphere.
7. The flow regulator of Claim 6 wherein said filter includes a layer of adsorptive material for preventing fuel vapors in said passageway from being vented to atmosphere.
8. The flow regulator of Claim 5 wherein said filter is an annular filter ring made of an adsoptive material said filter ring being retained between said first and second chambers for absorbing fuel vapors permeating through said diaphragm valve.
9. An evaporative emission control system for collecting fuel vapors vented from the vehicle's fuel tank and purging the fuel vapors into the intake system for combustion in the internal combustion engine, comprising:
a canister in communication with the fuel system for collecting the fuel vapors therein; and a vapor management valve for controlling the purging of fuel vapors from said canister into the intake system in response to an electrical control signal, said vapor management valve including a vacuum regulator having a vacuum inlet connected to engine manifold vacuum, a first chamber in communication with said vacuum inlet, a second chamber, a pressure-operable diaphragm valve retained for movement between said first and second chambers, inlet means connecting said canister for communication with said second chamber, outlet means communicating with the intake system such that movement of said diaphragm valve is operable for controlling flow between said inlet means and said outlet means, biasing means acting on said diaphragm valve for biasing said diaphragm valve to inhibit flow between said inlet means and said outlet means, first calibration means for varying the biasing force exerted by said biasing means on said diaphragm valve for setting a first flow rate value, and second calibration means for varying the flow in said inlet means to set a second flow rate value, said vapor management valve further including an electric vacuum regulator in communication with said first chamber of said first valve and having electrically-controllable means for generating a vacuum signal as a percentage of engine manifold vacuum received at said vacuum inlet in response to said electrical control signal, said vacuum signal being controllably regulated for generating substantially linear flow between said first and second flow rate values as a function of the magnitude of said electrical control signal and independent of variations in engine manifold vacuum, and a filter capable of capturing vapors which have permeated the diaphragm membrane and which is further capable of releasing the captured vapors during normal operation of the flow regulator and allowing the released vapors to be drawn into the intake system of the internal combustion engine for subsequent combustion.
a canister in communication with the fuel system for collecting the fuel vapors therein; and a vapor management valve for controlling the purging of fuel vapors from said canister into the intake system in response to an electrical control signal, said vapor management valve including a vacuum regulator having a vacuum inlet connected to engine manifold vacuum, a first chamber in communication with said vacuum inlet, a second chamber, a pressure-operable diaphragm valve retained for movement between said first and second chambers, inlet means connecting said canister for communication with said second chamber, outlet means communicating with the intake system such that movement of said diaphragm valve is operable for controlling flow between said inlet means and said outlet means, biasing means acting on said diaphragm valve for biasing said diaphragm valve to inhibit flow between said inlet means and said outlet means, first calibration means for varying the biasing force exerted by said biasing means on said diaphragm valve for setting a first flow rate value, and second calibration means for varying the flow in said inlet means to set a second flow rate value, said vapor management valve further including an electric vacuum regulator in communication with said first chamber of said first valve and having electrically-controllable means for generating a vacuum signal as a percentage of engine manifold vacuum received at said vacuum inlet in response to said electrical control signal, said vacuum signal being controllably regulated for generating substantially linear flow between said first and second flow rate values as a function of the magnitude of said electrical control signal and independent of variations in engine manifold vacuum, and a filter capable of capturing vapors which have permeated the diaphragm membrane and which is further capable of releasing the captured vapors during normal operation of the flow regulator and allowing the released vapors to be drawn into the intake system of the internal combustion engine for subsequent combustion.
10. The control system of Claim 9 wherein said electrically-controllable means includes an electromagnetic solenoid assembly having a passageway communicating with atmosphere an EVR chamber communicating with said first chamber a magnetic flux path including a magnetic armature member and means for establishing the flow of electromagnetic flux through said flux path said magnetic armature being movable for controlling flow through said passageway in response to the magnitude of said electric control signal supplied to said means for establishing flow of electromagnetic flux and said filter is located between said passageway and atmosphere.
11. The flow regulator of Claim 2 wherein said filter includes a layer of adsorptive material for preventing fuel vapors in said passageway from being vented to atmosphere.
12. The flow regulator of Claim 1 wherein said filter is an annular filter ring made of an adsorptive material said filter ring being retained between said first and second chambers for absorbing fuel vapors permeating through said diaphragm valve.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US08/303,234 US5429099A (en) | 1994-09-08 | 1994-09-08 | Anti-permeation filter for vapor management valve |
| US303,234 | 1994-09-08 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2157717A1 CA2157717A1 (en) | 1996-03-09 |
| CA2157717C true CA2157717C (en) | 2000-03-07 |
Family
ID=23171131
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002157717A Expired - Fee Related CA2157717C (en) | 1994-09-08 | 1995-09-07 | Anti-permeation filter for vapor management valve |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US5429099A (en) |
| EP (1) | EP0701056B1 (en) |
| CA (1) | CA2157717C (en) |
| DE (1) | DE69520395T2 (en) |
Families Citing this family (29)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19516545A1 (en) * | 1995-05-05 | 1996-11-07 | Bosch Gmbh Robert | Valve for the metered introduction of volatilized fuel |
| US5551406A (en) * | 1995-05-19 | 1996-09-03 | Siemens Electric Limited | Canister purge system having improved purge valve |
| DE69606994T2 (en) * | 1995-05-19 | 2001-03-15 | Siemens Canada Ltd | TANK BLEEDING VALVE WITH IMPROVED BLEEDING VALVE |
| US5630403A (en) * | 1996-06-13 | 1997-05-20 | Siemens Electric Limited | Force-balanced sonic flow emission control valve |
| US5749349A (en) * | 1996-10-24 | 1998-05-12 | Eaton Corporation | Fuel vapor control system |
| US6247456B1 (en) | 1996-11-07 | 2001-06-19 | Siemens Canada Ltd | Canister purge system having improved purge valve control |
| US5853018A (en) * | 1997-02-28 | 1998-12-29 | Eaton Corporation | Dampening resonance in a flow regulator |
| US5921261A (en) * | 1997-05-08 | 1999-07-13 | Eaton Corporation | Dampening resonance in a flow regulator |
| DE19723278C2 (en) * | 1997-06-04 | 2000-08-03 | Freudenberg Carl Fa | Device for the temporary storage and metered feeding of volatile fuel components |
| US5878725A (en) * | 1997-10-07 | 1999-03-09 | Borg-Warner Automotive, Inc. | Canister vent/purge valve |
| US5967183A (en) * | 1998-01-13 | 1999-10-19 | Eaton Corporation | Controlling vapor flow in a conduit |
| US6015133A (en) * | 1999-04-27 | 2000-01-18 | Eaton Corporation | Fuel vapor managment valve |
| DE60033057T2 (en) * | 1999-08-16 | 2007-05-31 | Delphi Technologies, Inc., Troy | INTEGRATED AIR FUEL MODULE WITH LOW FUEL GAS EMISSIONS |
| US6536261B1 (en) * | 1999-09-09 | 2003-03-25 | Siemens Automotive Inc. | Vacuum leak verification system and method |
| JP2001099016A (en) * | 1999-09-30 | 2001-04-10 | Denso Corp | Pressure control valve |
| US6347616B1 (en) * | 2000-05-10 | 2002-02-19 | Delphi Technologies, Inc. | Solenoid valve for a vehicle carbon canister |
| US6330878B1 (en) * | 2000-05-31 | 2001-12-18 | Siemens Canada Limited | Evaporative emission leak detection system including vacuum regulator with sensitive seal |
| DE10034033A1 (en) * | 2000-07-13 | 2002-01-24 | Nass Magnet Gmbh | magnetic valve |
| US6412335B1 (en) * | 2000-11-08 | 2002-07-02 | Eaton Corporation | Low current solenoid valve |
| US6432179B1 (en) | 2001-03-30 | 2002-08-13 | Honeywell International Inc. | Vapor-adsorbent filter for reducing evaporative fuel emissions, and method of using same |
| US6769416B2 (en) | 2001-05-11 | 2004-08-03 | Mitsubishi Denki Kabushiki Kaisha | Evaporated fuel processing module |
| WO2002092989A1 (en) * | 2001-05-11 | 2002-11-21 | Mitsubishi Denki Kabushiki Kaisha | Evaporative fuel processing module |
| US6474312B1 (en) | 2001-10-10 | 2002-11-05 | Honeywell International Inc. | Vapor-adsorbent underhood blanket, system and method of reducing evaporative fuel emissions from a vehicle |
| US7121267B2 (en) * | 2003-03-07 | 2006-10-17 | Siemens Vdo Automotive, Inc. | Poppet for an integrated pressure management apparatus and fuel system and method of minimizing resonance |
| US20040226439A1 (en) * | 2003-05-13 | 2004-11-18 | Visteon Global Technologies, Inc. | Integrated PZEV module |
| US7325577B2 (en) * | 2004-07-19 | 2008-02-05 | Stant Manufacturing Inc. | Tank venting system |
| US8839767B2 (en) * | 2010-07-29 | 2014-09-23 | Eaton Corporation | Relief valve and fuel vapor valve assembly |
| US9874137B2 (en) | 2015-06-17 | 2018-01-23 | Ford Global Technologies, Llc | System and method for canister purging |
| JP7099457B2 (en) * | 2017-05-22 | 2022-07-12 | 日立金属株式会社 | Proportional solenoid, its manufacturing method, and characteristic control method of proportional solenoid |
Family Cites Families (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1124594A (en) * | 1978-11-30 | 1982-06-01 | Brian W. Green | Engine with evaporation control system |
| US4534375A (en) * | 1982-02-17 | 1985-08-13 | Borg-Warner Corporation | Proportional solenoid valve |
| US4875499A (en) * | 1981-10-16 | 1989-10-24 | Borg-Warner Corporation | Proportional solenoid valve |
| US4534378A (en) | 1983-05-16 | 1985-08-13 | Adaptor, Inc. | Gate valve adaptor |
| US4567910A (en) * | 1984-11-26 | 1986-02-04 | Lectron Products, Inc. | Vacuum regulator |
| US4741317A (en) * | 1987-06-12 | 1988-05-03 | General Motors Corporation | Vapor recovery system with variable delay purge |
| US4951637A (en) * | 1989-06-29 | 1990-08-28 | Siemens-Bendix Automotive Electronics Limited | Purge flow regulator |
| US5050568A (en) * | 1990-03-08 | 1991-09-24 | Siemens Automotive Limited | Regulated flow canister purge system |
| US5065979A (en) * | 1990-01-10 | 1991-11-19 | Lectron Products, Inc. | Constant current vacuum regulator |
| US5115785A (en) * | 1990-05-01 | 1992-05-26 | Siemens Automotive Limited | Carbon canister purge system |
| US5083546A (en) * | 1991-02-19 | 1992-01-28 | Lectron Products, Inc. | Two-stage high flow purge valve |
| US5156178A (en) * | 1991-02-22 | 1992-10-20 | Stant Inc. | Vacuum-actuated vent assembly |
| US5183022A (en) * | 1991-07-16 | 1993-02-02 | Siemens Automotive Limited | Multi-slope canister purge solenoid valve |
| US5253629A (en) * | 1992-02-03 | 1993-10-19 | General Motors Corporation | Flow sensor for evaporative control system |
| US5277167A (en) * | 1993-02-04 | 1994-01-11 | Lectron Products, Inc. | Vapor management valve |
| US5358215A (en) * | 1993-06-25 | 1994-10-25 | Borg-Warner Automotive, Inc. | Encapsulated solenoid operated valve assembly |
-
1994
- 1994-09-08 US US08/303,234 patent/US5429099A/en not_active Expired - Lifetime
-
1995
- 1995-08-23 EP EP95113223A patent/EP0701056B1/en not_active Expired - Lifetime
- 1995-08-23 DE DE69520395T patent/DE69520395T2/en not_active Expired - Fee Related
- 1995-09-07 CA CA002157717A patent/CA2157717C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| US5429099A (en) | 1995-07-04 |
| DE69520395D1 (en) | 2001-04-26 |
| CA2157717A1 (en) | 1996-03-09 |
| EP0701056B1 (en) | 2001-03-21 |
| EP0701056A3 (en) | 1997-09-24 |
| DE69520395T2 (en) | 2001-08-30 |
| EP0701056A2 (en) | 1996-03-13 |
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Legal Events
| Date | Code | Title | Description |
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| EEER | Examination request | ||
| MKLA | Lapsed |