Great Wall GW491QE, Руководство по обслуживанию

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EF.1-21
cover
spring฀washer
(b)Principal:Being฀one฀mini-typed฀unit,฀the฀step฀motor฀is฀composed฀of฀one฀roll฀of฀steel฀stators฀and฀rotors฀(as฀shown฀in฀the฀fig ure
above):฀each฀steel฀stator฀has฀been฀wrapped฀with฀one฀coil;฀and฀the฀rotor฀is฀of฀one฀permanent฀magnet฀materially,฀at฀the฀center฀of฀which
is฀one฀nut.฀All฀coils฀on฀stator฀are฀always฀energized,฀and฀the฀change฀of฀current฀direction฀on฀any฀coil฀will฀have฀the฀rotor฀passing฀one
rotating฀angle.฀If฀the฀direction฀of฀current฀on฀each฀stator฀coil฀is฀changed฀as฀per฀some฀sequence,฀a฀rotating฀magnetic฀field฀will฀be฀produced
to฀drive฀the฀rotor฀made฀from฀permanent฀magnet฀to฀rotate฀in฀some฀direction;฀if฀the฀direction฀of฀current฀is฀changed฀in฀a฀reversed฀direction,
the฀rotating฀direction฀of฀rotor฀will฀be฀reversed฀as฀well.฀The฀nut฀at฀the฀center฀of฀rotor฀is฀able฀to฀have฀one฀piece฀of฀threaded฀rod฀moving
simultaneously,฀and฀could฀only฀move฀along฀the฀direction฀of฀axis฀as฀constrained฀by฀the฀design฀of฀screw฀rod,฀that฀why฀the฀so฀called฀name
traignt฀line฀axis’฀comes฀into฀being.฀On฀the฀end฀of฀the฀threaded฀rod฀is฀one฀choke฀plug,฀which฀is฀able฀to฀extend฀out฀or฀retract฀so฀as฀to
increase฀or฀decrease฀the฀cross-section฀area฀of฀bypass฀air฀inlet฀channel฀for฀idle-speed฀actuator฀until฀itblocked฀completely.฀The฀so-called
step฀length฀refers฀to฀a฀fixed฀rotating฀angle฀of฀rotor฀once฀the฀direction฀of฀current฀on฀coil฀is฀changed,฀and฀its฀value฀is฀equal฀to฀the฀number
of฀stator฀or฀coil฀divided฀by฀360 ,฀and฀the฀step฀length฀of฀rotor฀for฀the฀said฀step฀motor฀is฀15 .฀Therefore,฀the฀moving฀distance฀of฀screw
rod฀on฀eact฀step฀is฀fixed฀accordingly.฀The฀number฀of฀moving฀steps฀for฀step฀motor฀may฀be฀controlled฀by฀ECU฀through฀a฀control฀over
the฀change฀times฀of฀current฀on฀coil฀so฀as฀to฀adjust฀the฀cross-section฀area฀of฀bypass฀channel฀plus฀the฀flowed฀air฀capacity.฀The฀air฀flow
capacity฀VS.฀step฀length฀shows฀a฀linear฀correlation.฀And฀there฀one฀spring฀behind฀choke฀plug฀on฀the฀end฀of฀screw฀rod,฀as฀shown฀in฀the
figure฀above.฀The฀size฀of฀utilizable฀force฀along฀the฀extension฀direction฀of฀choke฀plug฀is฀equal฀to฀the฀force฀of฀step฀motor฀plus฀the฀spring
force;฀while฀the฀size฀of฀utilizable฀force฀along฀the฀retracted฀direction฀of฀choke฀plug฀is฀equal฀to฀the฀spring฀force฀reduced฀by฀the฀force฀of
step฀motor.
(c)Installation฀position:on฀the฀throttle฀valve฀unit.
(d)Symptom:฀too฀much฀high฀idle-speed,฀idle-speed฀flameout,฀etc.
(e)Cause฀of฀general฀failures:฀The฀accumulation฀of฀dusts฀and฀oil฀gas,฀etc฀causes฀partial฀blockage฀inside฀the฀bypass฀air฀duct,฀and฀leads
to฀an฀abnormality฀when฀adjusting฀the฀idle-speed฀of฀step฀motor.
(f)Precautions฀to฀maintenance:
1.฀Do฀not฀apply฀any฀force฀in฀axial฀direction฀to฀pull฀out฀the฀shaft฀or฀press฀it฀into฀place;
2.฀Prior฀to฀the฀installation฀of฀idle-speed฀adjustor฀(installed฀with฀step฀motor)฀into฀the฀throttle฀valve฀unit,฀its฀shaft฀shall฀ be฀at฀a฀place
able฀to฀be฀retracted฀completely;
3.฀Remember฀to฀clean฀and฀service฀the฀bypass฀air฀duct;
4.฀Following฀the฀removal฀of฀accumulator฀jar฀or฀ECU,฀an฀immediate฀self-learning฀shall฀be฀performed฀on฀step฀motor.
M7.9.7฀system฀self-learning฀method:
Open฀the฀ignition฀switch฀and฀start฀the฀engine฀five฀minutes฀later฀If฀any฀abnormality฀with฀engine฀idle฀speed฀is฀found,฀settle฀it฀by
peatingabove฀steps.
(g)Simple฀measurement฀method (after฀disconnection฀of฀joint)Have฀digital฀multimeter฀adjusted฀to฀the ohm position,
andconnect฀two฀pens฀with฀Pin฀AD฀and฀BC฀of฀adjustor฀respectively;฀The฀rated฀resistance฀when฀at
shall฀be฀
o฀ring
compressive฀spring
front฀bearing
dust฀cap
shaft฀pin
rotor฀assembly
stator฀assembly
cup฀shaped฀component
touch฀plate
bobbin
lead-wire฀of฀electromagnet
rotor฀sleeve
connector
pin
rear฀bearing
ball฀bearing
sleeve฀bearing
o฀ring
straight฀line฀axis
steel฀core฀of฀rotor
United฀Electronic฀engine฀management฀system-Analysis฀of฀function฀/principal฀/
failure฀for฀system฀parts฀&components
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