Babban matattu cibiyar da kasa matattu cibiyar: definition da kuma aiki
A cikin injiniyoyi, wurin tsaka tsaki ya dace da matsayin piston da ke jujjuyawa a cikin silinda. Akwai makafi guda biyu: babban matattu cibiyar, ko TDC, da kuma ƙasa matattu cibiyar, ko PMB. A babban mataccen cibiyar, fistan ya fi girma a bugun jini, yayin da yake a kasan silinda a tsakiyar matattu. Wannan yayi daidai da zagayen konewa daban-daban.
🚗 Menene cibiyar matattu?
Ayyukan injin konewa na ciki, kamar na mota, yana dogara ne akan pistons... Kowane ɗayan waɗannan pistons suna zamewa akan silinda kuma ana amfani da shi don damfara mai da iskar gas don haifar da fashewar, makamashin da ke motsa injin.
Motoci na zamani suna sanye da injin bugun bugun jini 4 wanda ke aiki cikin zagayowar guda hudu:
- Theƙofar shiga cakuda iska / man fetur;
- La (karfi) wannan cakuda ta hanyar ɗaga piston;
- Thefashewa lokacin da piston yana cikin matsayi mafi girma;
- Theéchappement lokacin da fistan ya tashi.
Don ƙirƙirar waɗannan matakai guda huɗu, pistons suna aiki tare da wasu sassa, ciki har da crankshaft wanda yake koya musu, amma kuma bawul waxanda su ne sassan da ke toshe hanyar shiga silinda. THE'camshaft yana ba da damar buɗe waɗannan bawuloli da rufewa, ba da izinin shiga cikin kashi na farko da shayewa a cikin kashi na huɗu.
Muna magana ne madadin fistan lokacin da fistan ke zamewa a cikin silinda kamar famfo, kamar a cikin injunan konewa na ciki. Duk da haka, a cikin yanayin injin piston mai maimaitawa, akwai maki biyu waɗanda ake kira maƙasudin tsaka-tsaki: babban mataccen cibiyar a gefe ɗaya, ƙasa matacciyar cibiyar a ɗayan.
Wadannan matattun wuraren ba su da alaƙa da watsawa. Haka kawai ya faru cewa kalmar "tsaka-tsaki" an ɗauke ta ta hanyar kwatanci zuwa ma'anar tsaka-tsaki: don haka, wannan shine matsayin da aka yi amfani da shi don yin nuni ga wannan matsayi na lever gear, amma wannan magana kuma ana amfani da ita a cikin kudi.
Babban mataccen wurin abin hawan ku, wanda galibi ake kira TDC, shine lokacin da fistan ya kasance a matakin mafi girman bugun jini a cikin silinda. Sabili da haka, shi ne lokacin da ƙarar ɗakin konewa ya kasance mafi ƙanƙanta kuma matsawa ya fi girma, kafin konewar cakuda iska da man fetur.
Ya kamata ku sani cewa firikwensin ya kira PMH Sensor, ke da alhakin gano lokacin da fistan ke a saman matattu a cikin abin hawan ku. Yana amfani da hakora jirgin sama... TDC firikwensin sannan yana watsa wannan bayanin zuwa ga sashin sarrafa injinwanda ke amfani da shi don inganta allurar mai da kuma cimma konewar da ke sa injin ku aiki.
🔍 Menene gindin matattu?
Le Babban matattu cibiyar (TDC) yana nufin lokacin da piston na injin konewa na ciki yana cikin matsayi mafi girma a cikin silinda lokacin da matsawa ya kai iyakarsa. Kuma akasin haka, Point Mort Bas (PMB) yayi daidai da lokacin da piston ke cikin mafi ƙanƙanta matsayi na bugun jini.
A wannan lokacin, ƙarar ɗakin konewa ya fi girma: wannan shine ƙarshen abin sha, wanda shine tsotsa cikin iska da man fetur, wanda cakuda zai haifar da fashewa da konewa na injin. Matsi a dabi'ance kadan ne kamar yadda ake yin cakuduwar, ba matsawa har ya fashe ba.
📍 Yadda ake samun babban matacce cibiyar?
Babban matattu yana nuna matsayi mafi girma na piston a cikin silinda. Amma kuma yana da wani amfani: sanin matsayi na babban mataccen cibiyar yana ba da damar tsare ta rarrabawa, wanda ya zama dole don wasu ayyukan injiniya a cikin injin.
Motar ku yawanci tana da repères don wannan saitin, amma wani lokacin kana buƙatar nemo matacciyar cibiyar da za ta yi alama da kanka. A wannan yanayin, kunna injin da hannu ƴan juyawa. Dole ne ku ƙayyade matsayin da piston yake a saman silinda kafin ya fara saukowa: wannan shine babban mataccen cibiyar.
Yanzu kun san menene sharuddan cibiyar matattu (TDC) da cibiyar matattu ta ƙasa (PMB) ke tsayawa. Kamar yadda kuka riga kuka fahimta, waɗannan sune mafi girman matsayi na piston a cikin silinda. Hakanan ya kamata ku sani cewa ba pistons guda biyu zasu kasance cikin lokaci ɗaya yayin konewa ba.
