汽车实用英语.docx

汽车实用英语.docx

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汽车实用英语

P82

UnitEight

textEngineIgnitionSystem

Allgasolineenginesrequiresomeformofignitionsystem．Thepurposeofthissystemis

to。

supplytothesparkplugs，withintheenginecombustionchambers，high．voltagesurges．

Furthermore，theignitionsystemmustprovidethesesurgesorsparkstothecorrectcylinder0f

theengineatthepropertimeinitsoperatingcycleformostefficientcombustion．Theresultof

thesesparks，ofcourse，isignitionoftheair—fuelmixturewithineach0fthecombustion

chambers.

Modernignitionsystemsoperatefromabattery．Conventionalsystemsconsistofthebattery,

ignitioncoil，distributor,condenser,ignitionswitch，sparkplugs，resistorandnecessarylowand

hightensionwiring．

Thebatteryistheheatofthetotalelectricalsystem．Inregardtotheprimarycircuit,its

functionistosupplyvoltageandcurrentflowtotheprimarywindingsoftheignitioncoil．inorder

toproduceanelectromagnet．

Theprimarysideoftheignitioncoilconnectsinseriesbetweentheresistorandthebreaker

points·Thefunctionofthiscoilwhencurrentpassesthroughitistocreateaverystrong

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electromagneticfield.Inotherwords,thecoilbecomesanelectromagnetwithNandSpoles.The

magneticfieldfromthiscoil,inturn,inducesavoltageinthesecondarywindingsthatisnecessary

tocauseanarcatthesparkpluggap.

Thesecondaryignitioncircuitnotonlytransformsthe6or12voltsofthebatterytoavoltage

highenoughtocauseanarcatthesparkplugbutalsodeliversthishigh-voltagesurgetothespark

plugs.Theautomotivebatterysupplieseither6or12voltstotheprimarycoilwindings.Butthe

voltagenecessarytojumpacrossthesparkplugairgapandignitetheair-fuelmixturecanrange

from5000to25000voltsormore,dependingupontheengine'soperatingconditionatanygiven

time.

Theignitiondistributorhasseveralfunctions.Itopensandclosestheprimaryignitioncircuit.

Itdistributesthehightensioncurrenttotherespectivecylindersoftheengine.Italsohasa

mechanismthatcontrolsthepointatwhichthebreakerpointsopen,therebyadvancingorretarding

thesparkinaccordancewithenginerequirements.

Thedistributorcapandrotorreceivethehigh-voltagesurgefromthesecondarycoilwindings

throughahigh-tensionwire.Thissurgeentersthedistributorcapthroughitscenterterminal,known

asthecoiltowertosparkplugelectrodesformedintotherimofthecap.

Therotoritselfmountsontheupperdistributorshaftandrotateswithit.Asaresult,therotor

electrodemovesfromonecapsparkplugelectrodetoanother,followingthespecificfiringorderof

theengine.

Thepurposeoftheignitioncondenseristoreducearcingatthebreakerpoints,andprolong

theirlife.Mostautomotivecondensersareformedfromtwothinfoilstrips,separatedbyseveral

layersofinsulation.Theinsulatingmaterialisknownasadielectricandisusuallypaperorany

similarnonconductivematerial.

Thesparkplugprovidesthegapinthecombustionchamberacrosswhichthehigh-tension

electricalsparkjumpstoignitethecombustioncharge.

Thepurposeoftheignitionswitchistoconnectanddisconnecttheignitionsystemfromthe

battery,sotheenginecanbestartedandstoppedasdesired.

WiththeignitionswitchON,andignitiondistributorcontactsclosed;currentwillflowfrom

thebattery,throughtheprimarywindingoftheignitioncoil,tothedistributorcontact（breaker）

points,tothegroundconnectionandbacktothebattery.

Thecurrentflowingthroughtheprimarywindingoftheignitioncoilproducesamagnetic

fieldinthecoil,Whenthedistributorcontactpointsopen（break）,themagneticfieldcollapseand

themovementofthemagneticfieldinducescurrentinthesecondarywinding.Sincetherearemany

moreturnsofwireinthesecondarywindingthanthereareintheprimarywinding,thevoltageis

increasedupto20000V.

Thedistributorthendirectsthishighvoltagetothepropersparkplug,whereitjumpstothe

gap.Theheatofthesparkignitestheair-fuelmixtureinthecombustionchamber.Theburningfuel

expandsandforcesthepistondown.Downwardmotionofthepiston,inturn,rotatesthe

crankshaft.

Theignitioncoilisapulsetransfomerdesignedtostepupprimaryvoltage（receivedfrom

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electromagneticfield.Inotherwords,thecoilbecomesanelectromagnetwithNandSpoles.The

magneticfieldfromthiscoil,inturn,inducesavoltageinthesecondarywindingsthatisnecessary

tocauseanarcatthesparkpluggap.

Thesecondaryignitioncircuitnotonlytransformsthe6or12voltsofthebatterytoavoltage

highenoughtocauseanarcatthesparkplugbutalsodeliversthishigh-voltagesurgetothespark

plugs.Theautomotivebatterysupplieseither6or12voltstotheprimarycoilwindings.Butthe

voltagenecessarytojumpacrossthesparkplugairgapandignitetheair-fuelmixturecanrange

from5000to25000voltsormore,dependingupontheengine'soperatingconditionatanygiven

time.

Theignitiondistributorhasseveralfunctions.Itopensandclosestheprimaryignitioncircuit.

Itdistributesthehightensioncurrenttotherespectivecylindersoftheengine.Italsohasa

mechanismthatcontrolsthepointatwhichthebreakerpointsopen,therebyadvancingorretarding

thesparkinaccordancewithenginerequirements.

Thedistributorcapandrotorreceivethehigh-voltagesurgefromthesecondarycoilwindings

throughahigh-tensionwire.Thissurgeentersthedistributorcapthroughitscenterterminal,known

asthecoiltowertosparkplugelectrodesformedintotherimofthecap.

Therotoritselfmountsontheupperdistributorshaftandrotateswithit.Asaresult,therotor

electrodemovesfromonecapsparkplugelectrodetoanother,followingthespecificfiringorderof

theengine.

Thepurposeoftheignitioncondenseristoreducearcingatthebreakerpoints,andprolong

theirlife.Mostautomotivecondensersareformedfromtwothinfoilstrips,separatedbyseveral

layersofinsulation.Theinsulatingmaterialisknownasadielectricandisusuallypaperorany

similarnonconductivematerial.

Thesparkplugprovidesthegapinthecombustionchamberacrosswhichthehigh-tension

electricalsparkjumpstoignitethecombustioncharge.

Thepurposeoftheignitionswitchistoconnectanddisconnecttheignitionsystemfromthe

battery,sotheenginecanbestartedandstoppedasdesired.

WiththeignitionswitchON,andignitiondistributorcontactsclosed;currentwillflowfrom

thebattery,throughtheprimarywindingoftheignitioncoil,tothedistributorcontact（breaker）

points,tothegroundconnectionandbacktothebattery.

Thecurrentflowingthroughtheprimarywindingoftheignitioncoilproducesamagnetic

fieldinthecoil,Whenthedistributorcontactpointsopen（break）,themagneticfieldcollapseand

themovementofthemagneticfieldinducescurrentinthesecondarywinding.Sincetherearemany

moreturnsofwireinthesecondarywindingthanthereareintheprimarywinding,thevoltageis

increasedupto20000V.

Thedistributorthendirectsthishighvoltagetothepropersparkplug,whereitjumpstothe

gap.Theheatofthesparkignitestheair-fuelmixtureinthecombustionchamber.Theburningfuel

expandsandforcesthepistondown.Downwardmotionofthepiston,inturn,rotatesthe

crankshaft.

Theignitioncoilisapulsetransfomerdesignedtostepupprimaryvoltage（receivedfrom

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CheckYourUnderstanding

I.Givebriefanswertothefollowingquestions.

1.Whatisthefunctionofthecondenserinthedistributor?

2.Whatisthefunctionoftheseriesresistor?

3.Howdoesthehighvoltageinduceinthesecondarywindings?

4.Whatdoestheignitionsystemconsistof?

II.Choosethecorrectwordtomatchthesentence.

ignitioninducedistributorcondenser

collapseelectrodecoronainsulation

1.________thematerialusedforinsulating

2._________toproducevoltagebyelectromagneticinduction

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3．_____________processwhichinitiatesthecombustionofthecompressedair-fuelmixtureinthecombustionchamber

4．_________afaintglowenvelopingthehigh-fieldelectrodeinacoronadischarge，often

accompaniedbystreamersdirectedtowardthelow—fieldelectrode

5．_______assemblywhichdistributestheignitionvoltagegeneratedintheignitioncoiltothesparkplugsinthefiringorderoftheengine

6．________tofalldownorinwardsuddenly；cavein

7．__________capacitorforthecontactbreakerofaconventionaldistributor

8．________conductorwhichleadscurl~ntintoagas，nquidorvacuum,suchasthoseinasparkplugbetweenwhichthesparkpassestoignitethemixture

Ⅲ．Fillinthetablebelow．

English

Chinese

High-tensionwiring

初级绕组

secondarywindings

串联

sparkplug

磁场

pulsetransformer

断电器触点

firingorder

接地

IV．TranslatethefollowingsentencesintoEugnshorChinese．

1．Thedistributorcapandrotorreceivethehigh—voltagesurgefromthesecondarycoil

windingsthroughahigh—tensionwire．

2．Allgasolineenginesrequiresomeformofignitionsystem．

3．点火线圈由初级线圈、次级线圈和铁心组成。

4．点火开关的作用是控制蓄电池与点火系统之间电路的通断。

BuildUpYourVocabulary

I．Writedownthewordsthattheimportantabbreviationstandsfor．

1．Hal______________热空气进气

2．HCV____________温度调节阀

3．HEPAF______________高效微粒空气过滤器

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4．HFRT_______________高频共振技术

5．HFPR_______________燃油泵高速继电器

6．HIC________________高温怠速空气补偿阀

7．HLBL______________前照灯光束高度校止

8．HEI________________高能点火

ReadingMaterialElectronicIgnitionSystem

Thefunctionoftheignitionsystemistoignitethecompressedairandfuelmixture，atthe

correcttime，andinitiateitsc