VVT shine gajartawar Ingilishi na Variable Valve Timeing. Matsayin cam na camshaft na injin gargajiya yana daidaitawa, yana aiki tare da lokaci na injin crankshaft, wato, kusurwar buɗewa da rufewa (lokaci) tsakanin bawul ɗin ci da shaye-shaye ba ya canzawa.

Sabili da haka, mafi kyawun Yana da wahala a cimma mafi kyawun aiki mai sauri a lokaci guda tare da ƙarancin saurin bawul ɗin lokaci na ", wato, ba shi yiwuwa a daidaita buƙatun kwanciyar hankali mara ƙarfi, fitarwa mai saurin gudu. da fitarwa mai sauri. Don warware buƙatun daban-daban na injin don lokacin bawul a cikin babban saurin gudu da ƙarancin saurin gudu, ana ɗaukar tsarin lokaci mai canzawa (VVT). An shigar da na'ura mai amfani da ruwa (VVT phaser) a gaban ƙarshen camshaft, kuma ana sarrafa matsa lamba ta hanyar lantarki. Hanyoyi don canza yanayin camshaft dangane da crankshaft don gaba ko jinkirta lokacin bawul. Ana nuna matakin VVT da taron camshaft a cikin hoton da ke ƙasa.

A halin yanzu, yawancin injunan mai suna sanye take da nau'ikan tsarin VVT iri-iri. Musamman ga injunan da ke da ma'auni mafi girma, an sanye su da injunan VVT guda biyu (cikewa da camshafts suna sanye da matakan VVT). A gaskiya ma, tsarin VVT yana saduwa da bukatun yanayi daban-daban na aiki kuma ya cimma daidaitattun ma'anar fasaha ta hanyar canza madaidaicin kusurwa. Gabaɗaya, yana da fa'idodi masu zuwa:

(1) Za'a iya daidaita lokaci na ci da shaye-shaye camshafts, wanda za'a iya ƙarawa ta hanyar tsari. Kusurwar haɗe-haɗe na bawul yana ƙara yawan iskar injin.

(2) Rage ragowar sharar iskar gas kuma inganta aikin caji.

(3) Haɓaka ƙarfin injin da juzu'i, da haɓaka tattalin arzikin mai yadda ya kamata.

(4) Babu shakka inganta kwanciyar hankali da sauri, ta haka samun kwanciyar hankali da rage hayaki.