CA2111423A1

CA2111423A1 - Traction control system valve

Info

Publication number: CA2111423A1
Application number: CA002111423A
Authority: CA
Inventors: Gerard Fred Smith; Laverne Andrew Caron; James A. Beverly
Original assignee: Eaton Corp
Current assignee: Eaton Corp
Priority date: 1992-12-28
Filing date: 1993-12-14
Publication date: 1994-06-29
Also published as: EP0604864A2; ZA939628B; CN1093987A; AU662283B2; KR940014037A; JPH06227382A; US5342119A; BR9305361A; AU5266193A; MX9400027A; AR248243A1; EP0604864A3

Abstract

Abstract A valve (100), for use with a vehicle brake system (102) including an electronic control unit (ECU) (126), including a valve body, a regulator assembly (140) internal to the body, a solenoid valve (142) internal to the body and a single double-check valve (144) internal to the body. The electronic control unit controls the traction control valve (100) during two modes of vehicle operation. The regulator assembly (140) is in fluid communication with a pressurized air supply (104) and regulates the air supplied to the brake system during one mode of operation. The solenoid valve (142) receives pressure-regulated air from the regulator assembly (140) and is controlled by the electronic control unit during the two modes of operation. The single double-check valve (144) receives pressure-regulated air from the solenoid valve (142) and receives pressurized air from the supply (104), such that the double-check valve (144) allows the pressure-regulated air to flow from the solenoid valve (142) to the brake system during the one mode of operation, and allows the pressurized air to flow from the pressurized air supply to the brake system during the other mode of operation.

Description

EA~ 0109 PUS ~ 2 3 91-A&B-363 TRACI'ION CONTROL SYSTEM VALVE
~bD6~ , The present invention relates to a valve for u~a in vehicular braking y~te~ and, more particularly, to a valve for enhancing a vehicular braking system to include traction capabili~y ~ .

A~ is known, there exi8t8 anti-locking brake and drive traction regulation ~y~t-m8 for use on motor v hicle- equipped with air br~k- system~ With anti-locking brak~ system~, the goal i9 to prevent locking o~
th- braked wheel~, enhanc$ng the ability to maintain control o~ th- vehicle during braking situations To achlev- this goal, braking ~orc-s are reducQd when an impending lock-up i~ sensed and increased when the i~p-nding lock-up ceases to exist With drive traction regulation syst-ms, the go~ to prevent the drive wh~ ro~ ~lipping during acceleration o~ thQ vehicle To achieve this goal, braking ~orces can be applied to th- ~lipping wheols, therQby incr-asing torque to the non-slipping wheela A drive traction regulation sy~tem can employ other strategies as well, ~uch a~ reducing motor torque by controlling combu~tion, or by upshi~tlng i~ an auto~tic tran-mi~sion is involv-d Du- to similarities in th- hardwar- roqulr-d to impl-m-nt them, anti-lock and driv- tractlon regulatlon ~y~t-m- o~t~n co-exist on v hicle~

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EAT 0109 PUS -2- 91-AhB-363 Re~erring now to Figure 1, there is illustrated a block diagram of an existing combination anti-lock braking/drive traction regulation system shown generally by the reference numeral 20 The combination system 20 include~ an electronic control module 22, multiple whe~l speed sensor~ 24, ~ultiple anti-lock brake valves 36, multiple double-check valve~ 2~ and ~ultiple high flow traction control valve~ 26 During the traction control event, the vehicle i~ accelerAting and a~ such, there i~ torque applied to the rear wheels 30 When the electronic control module 22 ~ense- a slipping rear wheel b~sQd upon data from the wheel speed sensors 24, it energize~ the traction control valve 26 on the slipping wheel only This cau~-- th- pr-~ure ~rom reservoir~ 32 to be applied via lin- 34 to th- appropriate double-check valve 28, on through th- anti-lock valve 36 and to the brake chamber 38 Applying th- brake~ to th- slipping wheel cau8Q~
th- torqu- (which normally tak-~ the path o~ lea~t r--istance) to b~ tran~erred to the non-slipping wheel, thu- providing enhanced traction cap~bility Tho anti-lock valv- 36 will thon be u~ed to control tho pres-ure on the ~llpping wheel such that the optim~l traction condition can b- maintained A similar system which ploys multipl- valves and multiple double-check valve~
i~ d--crib-d in United State~ patent nu~ber 4,819,995, ieeu-d to W hmann et al R-~-rring now to Flgur- 2, th-r- is illu-trated a block diagram ~or another exi~ting co~blnation anti-lock/traction control sy-tem, ~hown g-n-rally by r-~orence num-ral 50 A~ shown, th~
combination sy-t-m 50 include- ~n ol-ctronic control , ~ , '. ': ' :, . .. .
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EAT o1os Pus -3- 91-A&a-363 unit s2, multiple wheel speed sen~ors 54, a single high flow traction control valv~ 56, multiple anti-lock brake valve~ 58 and multiple double-check valves 60 During the traction control event, the vehicle i9 accelerating and as ~uch, there is torque applied to the rear wh-els 62 When the eloctronic control module 52 ~en~es a slipping wheel based upon data from the wheel spe~d sensors 54, it energize~ the tract$on control valve 56 and energize~ the ABS valve 58 a~ociated with the non-slipping wheel Energizing the traction control valve 56 re~ult~ in air flow from the re~ervoir 64 to the double-check valves 60, thus causing the~ to seal off air to lines 66 Thi~ prevQnts the air rrO~ b inq exhausted out through th- relay valve 68 This air then continues on to th- ABS valves 58 The AB8 valv- S8 associated with the non-~lipping whe-l i~
n-rgiz-d and a- sUCh~ it do-- not allow air to ~low to th- a~-ociat-d br~ke chambQr 70 Th~ ABS valv- 58 a--ociat-d with th- slipping wh--l will allow aix to pr---urize tho a~sociated br~ke ch~ber 70 and a- ~uch, th torqu- will be transrerred to the non-slipping whe-l The anti-lock valve 58 will then be u~-d to control th- pro~sure on the ~lipping wheol such that the opti~al tr wtlon condition can bo maintained .~ ~
The d--ign Or both traction control syste 20 and 50 i~ such that they require the traction control valve~ to 8Upply air ~rom th- high pre~ure syste~
r---rvoir dir-ctly to the brak- chambors Th- ract that tho br~k- ch~b-rs are Or an appr-ciable volum- and that th- traction control sy~tem must r-act roason~bly quickly, require- the~e valve~ and th- a-sociated double ch-ck valv-- to bo o~ a d--ign lev-l that provldo- a .......

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EAT 0109 PUS -4- 91-A&B-363 high flow capability This mako~ these valve~ large and complex and as such, more costly The braking forces required for traction control are also only a fraction of those required for full braking There~ore, applying the full system pressure to the brake cha~bers, a~ i3 done in both sy~te~s 20 and S0, make~ tho control of these syste~s more dif~icult It is, therefore, d-sirable to provide a traction control system with 1Q~- components and that thess components b~ of a le~ complex and l¢s~ costly do~ign lev~l Al~o, it is de~irable to utilize a control pro~sure that i~ at a lower level than full system pre~sure ~a~e~

It i9i, thereforo, an ob~ect of the pre~ent invention to provide an improved valve, for UD- with an anti-lock brak-/traction control ~yste~, having l-~
hardware, b ing le~- complex and le~- co-tly It i~ further ob~ect of th- pre--nt inv-ntion to provid- an improved valve that utilizes a control pr---ur- that is les- than the sy~tom pre--ur-In carrying out th- abovo ob~ect~, and other ob~ct~ and ~-ature~ of thQ pro-ont invention, a valve i- provided ~or u-e with an anti-lock brake/traction 2S control sy~to~ is provided Th- valv- i~ located on tho control lin- o~ the relay valve, such th~t on- low flow valv- ~nd on- low ~low double-ch-ck valv- can b u~-d Th- valv- al-o lnclud-- a pr---ur- r-gulator, uch that a ~ore de~irable control pre~-ur- can b- attained Mo~t , . " ,, . ,, ; .
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EAT 0109 PUS -5- 91-A&B-363 preferably, a pressure regulator, an electrically controlled low flow 3-way valve and a single double-check valve are preferably combined into one valve body thu~ simplifying the system even further In further carrying out the above object and other object~ and featurea of the pre~ent invention, a valve is provided, for use with a vehicular air brake sy~tem including an electronic control unit, for controlling air flow from a pressurized air supply to the brake system during two mode of vehicle oporation The valve comprises a valve body and a regulator ass-mbly internal to the valve body in fluid communication with the pressurized air supply~ The r-gulator aJsombly pre~sure-rQgulate~ the air supplied lS to th- brak- ~y-tem during on- Or the two modes o~
oporatlon Tho valvo also includo- a solenoid valve internal to the valv- body ~or roceiving pre~sure-rogulatod air ~rom tho regulator a-sombly The golenoid valvQ i~ controlled by the electronic control unit during the two modos Or op-ratlon Th~ valv- al~o include~ a ~ingle double-check valve internal to the body and in rluld communication with the solenoid valve and th- pro--urized supply The double-chock v~lve allow- tho pre~ure-regulated air to ~low from the ~ol-noid valv- to the brake sy~tem during the one mode o~ op-ration, and allow~ tho pres~urized air to ~low ~rom tho pr-~urized air supply to the brake sy~tem during the other mode o~ operation T~- advantago- accruing to th- pre~ont inv-ntion ar- numoroug For ex~mple, tbe valv- o~ the pro~ont inv ntion is de~igned to be incorporat-d into a tandard ~ir br~ke ~y~tem th~t 1- con~igur~d wlth ~n .. . .
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1114~3 - EAT 0109 PUS -6- 91-A&B-363 existing anti-lock brake system and a relay valve on the rear brake~ The de~ign of the valve is such that it will be located on the control, or low flow, ~ide of the relay valve, a3 oppo~ed to existing traction valves that are located on the output or high flow side of the relay valve Valve complexity is reduced, reducing the a~sociated C08t.

When energizQd, the sol~noid valvR portlon of the pre~ent invention allows air at a regulatad pre~sure to flow to the control line of the relay valve The double-che~k valve portion of this invention seals off ~he portion o~ the relay valve control line that return~
to the treadle valve, thus preventing this air ~rom exhau~ting out to atmosphere through the treadle valve Th- r-lay valve, b ing a flow amplifier for the raar brak- chamb~r-, provid-- a high ~low sourco o~ air to th- rear brak- ch~mb-r~ at the r-gulated control pr-~ur- l-v-l d-t~rminod by this invention Upon energizing o~ the pre~ent invention, the el-ctronic control unit energizes the anti-lock brake valv on the non-slipping wheel Thi~ blocks the air to thi- whe-l and applies th- brake~ to the slipping wheel, thu~ r--ulting in a transfer o~ torque and i~proved traction on the non-slipping wheel When de-energized, 2S thi~ valvo xhau-t- th- pressure at tho control line of th- r-lay valve and, a~ ~uch, causes the relay valve to xhau-t pr--~ur- on the rear brakes During normal op-ration, th- double-check valv- of th- pr---nt inv-ntion ~huttle~ to ~eal the normal relay valve control air ~rom exhau~ting out to atmo~ph-r- through thi~ Lnv-ntion ,~ ;, . . . . . . .
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, , , ~: . " ,, ~' 2~ 114~3 EAT 0109 PUS -7- 91-A&B-363 The above objects and other object3, features, and advantage3 of th~ pre~ent invention will be readily appreciated by one of ordinary skill in the art from the following detailed description of the be~t mode for carrying out the invention when tak~n in connection with the accompanying drawings Brief Description of the Drawin~
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FIGURE 1 i~ a block diagram of an existing co~bination anti-lock brake/drive traction regulation sy~tem;

FIGURE 2 is a block d$agram illu~trating anoth-r existing combination anti-lock brake/drive traction r~gulation sy~tem;

FTGURE 3 iJ a block dlagr~ o~ an iuprov-d co~bination antl-lock br~k-/drive traction regulation ~y-t-~, includlng a block dlagram 100 o~ the valv- Or th- pr---nt invontion;

FIGURE 4 is a side view Or the valve shown by th- block dlagra~ in FIGURE 3 0~ tho pre~-nt inv ntion;

FIGURE 5 i~ a cross-~-ctlon o~ the valv shown in FSGUR~ 4 t~k-n along lln~ 5-5, illu~tratlng the int~rnal pr~sur- r-gulator; and FIGUaE 6 i~ a cro~ oction partly in l-vation o~ the valve shown in FIGURES 4 and 5, lllu-trating th- lnt-rnal ol-noid valve and th- ~ingle lnt~rn~l doubl--ch-ck valv-. . . ~ - .,~

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-` 21114?~3 EAT 0109 PUS -8- 91-A&B-363 Referring now to Figure 3 there i8 illustrated a block di~gram of a v~lve shown generally by reference numeral 100 for UBQ with a combination anti-lock brake~drive traction regulation 3yete~ shown generally by reference nu~eral 102 A3 illustratQd the system 102 includes a pressurized source of air or tank 104 a treadle valve 106 including a brake pedal 107 a br~ke air system relay valve 108 anti-lock braking sy~tem (ABS) valves 110 and 112 and air chamber~ 114 and 116 T~e wheel sensors 118 and 120 provide spqed data ~or the whe-l~ 122 and 124 to an electronic control unit (ECU) shown generally by reference numeral 126 Ba~ed on this data the electronic control unit 126 can detect 1~ an l~p-nding lock-up Or who-l~ 122 or 124 during vehicle braking or an actual ~lip of wh--ls 122 or 124 during v hicle acc~leration Depending on the condition d-tected ~i e wheel lock-up or wheel 81ip), the el-ctronic control unit 126 control~ op-ratlon o~ tho valve 100 and the ABS valve~ 110 and 112 a- do-cribQd in greater d-tail herein b low With continuing re~er-nce to Flgure 3 the tank 104 supplie~ air und-r pre~-ure to the supply ports o~ valve 100 the treadle valve 106 and the brake air sy-tem relay valve 108 ~he air supplied ~rom th~ tank 104 ha- a pre~-ure associated with a typic~l compros~or s-tting such a~ 90-120 psi Thu- air in that pr~s~ure range enter~ the valve 100 through supply lin- 126 via th- ~upply input port shown by r-~-renc- num-ral 128 Alr in thls pr-~-ure ran~- al-o ntor~ th- br~k~ air sy-t-m relay valv- 108 at th- supply input 130 via supply llne 132 Pressurized air i~ also supplied to :: '''' ' 211~ 423 EAT 0109 PUS -9- 91-A&B-363 the valve 100 at the treadle valve input 134 via treadle supply line 136 The pre~qure of the air supplied to the valve loO from the tre~dle v~lve 106 varies from zero p8i to about 100 p8i, depend~ng on the force S exerted by the vehicle operator on the brake pedal 107 As ~hown in Figure 3, the valve 100 preferably ha- a body and includes an internal regulator a~sembly shown generally by reference numeral 140, an internal 3-way solenoid valve shown generally by reference numeral 142 and an internal single double-check valve shown gen-rally by reSerence numeral 144 The regulator a-J-mbly, solenoid valve and double-check valve are de-cribed a~ internal since they are disposQd within the body o~ the valve The solonoid valve 142 i~
1~ co~o-rcially available ~rom Rostra Controls oS
~urlnburg, North Carolina, Unit-d State- of Auerica Th- int-rnal r-gulator a~sombly co~ponents 140, co~o-rcially available from Norgr~n Corporation of Llttleton, Colorado, Unit~d State~ of Ac rica, are in fluid co~ounicatlon with the supply llne 126 fro~ the tank 104 The regulator a-~embly 140 functions to r-gulat- th- tank or brake sy~te~ pres-ure down to a 1-~ 1 Or approximat-ly 40 p~i R ferring now to Figure~ 4, 5 and 6, the valve 100 i- shown in greater detail A- be-t shown in F~gure 5, th- internal regulator aJsembly 140 includes a spring 180, a spring retainer plate 182, a rubber diaphragm 184, a ca~ity 186, a guide bushing 188, plunger 190 and a ~pring 192 which surround- th- plunger 190 Wlth continuing r-f-r-nc- to Figur-- 4 and 5, with no air pr-~-ur- at ~upply lnput port 128, th-.. . . .

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EAT olos PUs -10- 91-A&8-363 spring 180 expands, biasing th~ sprin~ retainer plate 182 and rubber diaphrag~ 184 upward, such that the rod 196 comes into contact with plunger l9o When pressurized air is applied to the supply input port 128, air flows through orifice~ 194 (shown in phantom) and fills the cavity 186 A~ the pres~ure rise~ in cavity 186, the diaphragm 184 and thQ spring retain-r plate 182 ar- biased downward~ Thi~ continueg until ~ point where the travel of rod 196 is such that plunger 190 can be forced by ~pring 192 to seal on the guide bushing 188 This re~ults in the pressure in cavity 186 stabilizing at a steady value -~

The spring rate of spring 180 and the area o~
th~ rubber diaphrag~ 184 detsrmine the regulated pr-J~ur- In th- pre~erred embodiment, the spring 180 ha- a spring rat- value and tho diaphragm 184 i~ ~ized uch that th- r-gulatod preJ~ure d~livered to the ~olenoid val~- 142 through ~luid connection 148 i8 about 40 p-i R-ferring now to Figure 6, a cros~-~ection partly in el-vation o~ the valve 100 is ~hown, illu-trating th- int~rnal solenoid valve as~embly 142 and the single internal double-check valve 144 As ~hown in Figure~ 3 and 6, the valve 100 include~ a 2S conn-ctor rec-ptacle 200 Electrical wir~ ~xt-nd ~rom th- sol-noid valv 142 to the plurality o~ contactJ 202 Th- receptacle 200 receives a connector plug ~not shown), which i9 electrically connected by wire~ to the A b -t shown in Flgure 6, the solenoid valve 142 lnclude- a port a~ bly shown g-nerally by ; .. . .
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- 211142~
- EAT 0109 PUS ~ 91-A&B-363 reference numeral 204 In the preferred embodiment, the port assembly 204 includes a pair of 0-rings 206 and 208, and re~sins stationary within the valve 100 A
plunger as~embly (not specifically illu3trated) is positioned within the port a~efflbly 204 The plunger a~embly move~ relative to the port ~sembly 204, in a known fashion, upon energization/de~nergization of the ~olenoid v~lve 142 by the ECU 126 to control air flow to the single double-check valve 144 With continuing reference to Figure 6, pressure regulated air from the regulator assembly 140 is delivered to the low flow solenoid valve 142 through the ~luid connection 148 When the electronic control unit 126 activate~ this solenoid to th- energized state, a plung-r (not sp-ciric~lly illustrated) in the valve ~ov-~ upward, thu- op-ning up an inlet port and sealing an exhau-t port (not sp-ci~ic~lly illustr~tod) The pr---uriz-d air th-n rlow- through tho v~lvo and out the working port 210 Thi- air th-n tr~vels down ~luid conn-ction lS0 and on to the double check valve 144 Wh-n th- low rlow olenoid valve i- de-energized, the plung-r in th- v~lve returns to its original state via a pring return This seals O~r the inlet air and opens up the exhaust port, thu~ allowing the air that wa~
2~ uppli-d to the double check 144 through fluid conn-ction lS0 to exhau~t to atmo~phere Wlth combined reference to Figure~ 3 and 6, the valve 100 is pre~erably machined to includ- a ~ingle internal double-check valve 144 The ball 214 o~ the doubl--check valv- i- bias-d ~rom end to ~nd th~r-within ln ~ known ~ann-r A- b--t shown in Figure 6, the doubl--checX valve 144 pre~Qrably include~ a plurality 21~1~2~
EAT 0109 PUS -12- 91-A&B-363 of ports 216 dispo~ed radially around the central portion of the double-check valve Most preferably, the ports 216 are relatively small ~o as not to nick or otherwise damage the surface of the ball 214 as it moves within the double-check valve 144 The port~ 216 are in fluid cwDmunicat$on with an annulus 218, which in turn is in fluid communication with the control air line port 158 (beet shown in Figure 5) In Figure 6, the ball 214 i5 shown biased to one end due to air pressure entering the double-check valve 144 from thQ treadle valve input port 134 Thi~
pre~urized air then exits tho double-check valve 144 through the parts 216, the annulus 218 and the contro~
alr line port lS8, shown in Figure~ 4 and S The 0-ring lS 220 ~unction~ a- a s-al to insurQ against air leaks R turning once again to Figure 3, operation of the valve 100 will be di~cu~-d during nor~al braking and during traction control Pre-~ure regulated air frol the regulator a-~embly 140 i8 communicated to the ~ol-noid valve 142 via the ~upply air line 148 The el-ctronic control unit 126 energizs~ the ~olenoid valve 142 d-p-nding on whether a traction control situation xist~ A~ de~cribed in greator dotail below, the l-ctronic control unit 126 controls thQ solenoid valvo 142 to a d--n-rgiz-d state during normal braking and to an energized ~tate during traction control During normal braking, th- oporator applies ~orc- to the brake pedal 107, thw opening th- treadle valv- lOC and ~upplying pre~-uriz-d air ~rom th- tank 104 to th- lln- 136 and on to tho treadle input port 134 o~ the traction control valve 100 Thi~ pr~--urized alr . ,. .. , ,., , ~., . ~ , , , ~, " , . . , , : , .

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EAT 0109 PUS -13- 91-A~B-363 varies from 0 to approximately 100 psi depending upon the force applied by the operator on the brake pedal The air flow through the traction control valve lO0 displaces the ball in the double check valve 144 away fro~ the direction Or flow, thus s~aling ofr the internal lin~ 150 in th~ tr~ction v~lve ~his r-Jults in the air pr-~sure b~ing s~led fro~ le~kiing out to atmosphere through the low flow solenoid valve 142 The air, se~led from exhausting to atmo6phere, now travels out of the traction valve lO0 via the relay port 158 and on to the control chamber of the relay valve 108 In the pre~erred embodim-nt, the relay valve 108 includes an internal piston and spring assembly In its normal state, the spring biaBe~ the piston closed, lS thu~ s-aling on- port which allow~ the supply air from tank 104 ~rom b ing communicated to the brake ch~mbers and al~o op-ning up another port which exhausts any air currently in th- brake chamber- to atmospher- When air nt-rs th- control chamber via lin~ 160, this ~orc-- the pi~ton downward, thua opening tho supply port and clo~ing the exhaust port in the rolay valve This allow- air ~rom the tank 104 to be communicated to the br~ke cha~k r~i This air travel~ ~rom the tank 104 through line 132, and then through th- relay valve 108 2S It continu-- down line- 154 and 156, through the normally op-ned anti-lock valves 110 and 112 and on to the brak- cha~ber~ 114 and 116 80 a- to provide rorce to apply the brake- Thus, th- r-lay valve 108 acts a- a ~low a~plirier by taking a small rlow at a given pre-~ure at the control port and converting it to a much larg-r ~low at th- sam- pre--ur- at th- outl~t ports , " " , ~ ", ,~

2111~3 EA~ 0109 PUS -14- 91-A&B-363 When the operator relea6es his foot from the brake p~dal 107, it in turn causes the air in the control port 133 of the relay valve 108 to b~ exhausted through line 160 and line 136 out through the treadle valve 106 Tho ball 214 in tho double-chock 144 of the traction control valve lOo remains in the ~tate it was previously in until the pres~urs in this line i3 exh~ustQd Removing the control pr~--ure ~roa the rel~y valve cau~es the piston to return to itQ originAl state, closing the supply port and opening the exhau~t port for the brake chamber air During normal braking conditions, the ECU 126 monitor~ the wheels 122 and 124, utilizing t~e wheel sp--d sen~or~ 118 and 120 If a wheel lock-up, or wheel skid, iJ detocted tho braking pros~ure on th- wheels is too great In re-pon~-, the ECU 126 controls the appropriat- ABS valv- 110, 112 to r-duc- the air pr---ur- d-livered to the air chamber, ~o that the whQel can rotat- on the road surrace during braking A- previou~ly montioned, the valve 100 provid-~ th- sy~tem 102 with traction control capabilitie- Genorally, a traction control situation ari~-~ a- the v-hicle i9 accelerated rrom a re~ting po-ition When accelerating hard or when accelerating during le-s than optimal driving conditions, the wheel having th- lowe~t coerricient o~ friction surraco can br-ak rr-- and ~pin on tho road ~urface Thi~ ~pinning wheel b comoJ tho path o~ lea~t re~ietanco ~or the drivelin-, and all Or the drivelino torquo ~low~ out through that wheel, resulting in dograd-d v-hicle acc-l-ration and increa~ed tire w-ar By applying brake pr---ur- to the spinning wh--l, torqu- i9 tran-rerred to -~ 211~423 EAT 0109 PUS -15- 91-A&B-363 a wheel having a higher coefficient of frlction with the road surface With continuing reference to Figure 3, the ECU
126 monitors the wheel speed sensors 118 and 120 to detect the occurrence of a traction control situation Gonerally, tha ECU 126 enters a traction control mode when thQ wheel speed sen~ors 118 and 120 on tho drive axles indicate a whsel spinning at a ~peed greater than on a non-driven axle 10For exa~ple, asEumo the vehicle is acceleratinq and the ECU 126 has dotQcted that wheels 122 have 108t traction and are spinning To regain traction, the ECU 126 energizes tho ~olenoid valve 142~
A do~cribed in greater detail above, prss~ure regulat~d lSair ~1 e about 40 p8i) from the regulator ass-~bly 140 ~low- through the d-livery air lino 150 to the double-ch-ck valv 144 Slnce th~ v hicl- drivor i~ not d-pres-ing tho brak- pedal 107, thi- pr~s~ure r-gulated air bias-- th- ball 214 Or the doublo-check valve 144 away fro~ th- dolivsry air line lS0, allowing the air to xit tho doublo-check valvo and flow to th- relay valv~
108 through tho control line 160 Th- pro~ure regulatod air di~place~ the internal piston Or the relay valve 108, and air at an equivalent pro~sure (i e about 40 psi) exits the valve 108 and ~low- to the ABS valve 110 and 112 through the brake air line~ 154 and 156 At tho inJtant that the ECU 126 energize~ the traction control valve 100, it also enorgiz-- the antl-lock brak- valva 112 a-sociat~d with th- non-~lipping ~, , .. . . , , ,. , , .~
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- EAT 0109 PUS -16- 91-A&~-363 wheels 124 This blocks the flow of air to the non-slipping wheel brake chamber 116 and, as such, prevents brake torque Srom being applied to this wheel Air is, however, allowed to pass to the brake chamber 114 of the slipping wheel and thus, the brake~ of this wheel are applied By thi~ ~-thod, th~ torque, which nor~ally takQs the path of least re~istance (i e the slipping wheel), will be directed to the non--llpping ~ide and, as such, allow the vehicle to accelerate As the traction control event continues, the anti-lock brake valves 110 and 112 will be used to control the brake pressure~ in both wheels such that the optimal traction conditions are maintained At speeds above about ten miles per hour or lS when the ECU determines that wheel slip i9 no longer pr-J-nt, th- traction control valve will b~ de-n-rgiz-d ~hls will allow th- air in the control port 130 o~ the r-lay valvo 108 to b exhausted via lineo 160, traction control valve intQrnal line 150 and out through the Qxhaust port o~ the solenoid 142 ~he ball in the doubl~-chQck valve 144 o~ the traction control valve 100 will re~ain in pooition ~-aling o~ the tr-adlo input lin- until th~ pre~ur~ in the valves drop- to almo-t 0 poig Exhau-ting the control air of th- r-lay valv- in turn caus~o th- air in brake chambers to also be exhausted through the relay valv- thus r-turning the entire brake system to its normal state one Or ordinary skill in th- art will r-cognizQ many advantages aosociated with the uo- o~ the valve 100 For example, a combination anti-lock brake and tractlon control 9y-tem can b d-~lgn-d utillzing 1-~- hardwar- than xl~tlng ~y-t-m~ A ~ingle ~mall~r ' ,~ , , ; ', ' ': ' .: .
,. . . . . .
:' ' , , ~ ;, ', : . ' . ,, ' EAT 0109 PUS ~ 2 3 91-A&B-363 valve can be utilized, positioned on the control side of -the brake ~ystem relay valve. Additionally, a substantial cost saving~ i8 realized, since mschanical hardware in the form of a mechanical traction interlock S on the axle is no longer required.

It is understood, of course, that while the form of the invention herein shown and de~cribed constitutes the preferred embodimænt of the invention, it i~ not intended to illustrate all possible forms thereof. It will also be understood that the words used ar~ word~ of description rather than limitation, and that variou~ change~ may b~ made without departing from th~ ~pirit and scope of the invention as disclosed.

.. , . :, - . . . - - .,. , , ~ ~. .

Claims

1. A valve (100), for use with a vehicular air brake system (102) including an electronic control unit (126), for controlling air flow from a pressurized air supply (104) to the brake system during two modes of vehicle operation, the valve comprising:
a valve body;
a regulator assembly (140) internal to the valve body in fluid communication with the pressurized air supply (104), the regulator assembly for pressure-regulating the air supplied to the brake system during one of the two modes of operation;
a solenoid valve (142) internal to the body for receiving pressure-regulated air from the regulator assembly (140), the solenoid valve being controlled by the electronic control unit (126) during the two modes of operation; and a single double-check valve (144) internal to the body in fluid communication with the solenoid valve (142) and the pressurized supply (104), the double-check valve (144) allowing the pressure-regulated air to flow from the solenoid valve (142) to the brake system during the one mode of operation, and allowing the pressurized air to flow from the pressurized air supply (104) to the brake system during the other mode of operation.

2. The valve of claim 1 wherein the brake system includes a relay valve (108) having a control air line (160) in fluid communication with the double-check valve, the relay valve amplifying the flow and maintain-ing the pressure of the air provided to the brake system from the solenoid valve (142) during the one mode of operation.

3. The valve of claim 2 wherein the relay valve (108) amplifies the flow and maintains the pres-sure of the air provided to the brake system from the pressurized supply during the other mode of operation.

4. A valve (100) for controlling the trac-tion of at least one vehicle wheel (122,124) slipping on road surface, the traction control valve for use with a vehicular air brake system (102) including at least one brake valve (110,112) controlled by an electronic control unit (126), the traction control valve compris-ing:
a valve body;
a regulator assembly (140) internal to the body for pressure-regulating the air supplied to the brake system;
a single double-check valve (144) internal to the body, the double-check valve allowing the pressure-regulated air to flow from the regulator assembly (140) to the at least one brake valve (110,112), the electron-ic control unit (126) controlling the at least one brake valve to apply brake pressure to the at least one slipping wheel (122,124) until traction with the road surface is obtained.

5. The valve of claim 4 further comprising a solenoid valve (142) internal to the body, the sole-noid valve being controlled by the electronic control unit (126) to allow the pressure-regulated air to flow from the regulator assembly (140) to the double-check valve (144).

6. The traction control valve of claim 5 wherein the brake system includes a relay valve (108) having a control air line (160) in fluid communication with the double-check valve (144), the relay valve amplifying the flow and maintaining the pressure of the air provided to the at least one brake valve (110,112) from the double-check valve (144).

7. A traction control valve (100) for controlling the traction of at least one vehicle wheel (122,124) slipping on a road surface, the traction control valve for use with a vehicular air brake system (102) including at least one brake valve (110,112) controlled by an electronic control unit (126), the traction control valve comprising:
a valve body;
a regulator assembly (140) internal to the body, the regulator assembly for pressure-regulating the air supplied to the brake system;
a solenoid valve (142) internal to the body, the solenoid valve being controlled by the electronic control unit (126) to allow the pressure-regulated air to flow from the regulator assembly to the double-check valve; and a single double-check valve (144) internal to the body, the double-check valve allowing the pressure-regulated air to flow from the solenoid valve (142) to the brake system, the electronic control unit (126) controlling the at least one brake valve (110,112) to apply brake pressure to the at least one slipping wheel (122,124) until traction with the road surface is obtained.

8. The valve of claim 7 wherein the brake system includes a pressurized air supply (104) and wherein the electronic control unit (126) controls the traction control valve during two modes of vehicle operation, such that pressure-regulated air from the regulator assembly (140) flows to the at least one brake valve (110,112) during one mode of operation, and air from the pressurized air supply flows to the at least one brake valve during the other mode of operation.

9. A combination anti-lock air brake and traction control system (102) for use on a vehicle having at least one wheel (122,124) with a brake, the system being controlled by an electronic control unit (126) during two modes of vehicle operation, the system comprising:
a source of pressurized air (104);
an air brake system relay valve (108) in fluid communication with the source of pressurized air, the relay valve including a control air line (160);
at least one brake valve (110,112), positioned proximate the brake, for supplying air from the relay valve (108) to the brake, the at least one brake valve being controlled by the electronic control unit (126);
and a traction control valve (100) in fluid communication with the source of pressurized air (104) and the control air line (160) of the relay valve (108), the traction control valve including a valve body and a pressure regulator (140) internal to the body, a sole-noid valve (142) internal to the body and a double-check valve (144) internal to the body, the electronic control unit (126) controlling the traction control valve (100) to apply the brake to the wheel during the two modes of vehicle operation.

10. The braking system of claim 9 wherein the traction control valve provides pressure-regulated air to the control air line (160) of the brake air system relay valve for distribution to the at least one brake valve (110,112) during one mode of vehicle operation, and wherein the traction control valve provides air from the pressurized source to the control air line (160) brake air system relay valve for distribution to the at least one brake valve (110,112) during the other mode of vehicle operation.

11. The braking system of claim 10 wherein the one mode of operation is a traction control mode during which the at least one vehicle wheel (122,124) is slipping on a road surface, the electronic control unit (126) controlling the at least one brake valve (110,112) to apply brake pressure to the slipping wheel until traction with the road surface is obtained.

12. The braking system of claim 10 wherein the other mode of operation is an anti-lock braking mode during which the at least one vehicle wheel (122,124) is skidding on a road surface, the electronic control unit (126) controlling the at least one brake valve (110,112) to vary brake pressure to the at least one wheel (122,124) until the at least one wheel rotates on the road surface.

13. The braking system of claim 10 wherein the brake air system relay valve (108) amplifies the flow and maintains the pressure of the air provided to the brake valve from the double-check valve (144) during the one mode of operation.

14. The braking system of claim 10 wherein the brake air system relay valve (108) amplifies the flow and maintains the pressure of the air provided to the brake valve from the pressurized supply during the other mode of operation.

15. The braking system of claim 10 wherein the pressure-regulated air has a pressure of about 40 psi.