Siyini isikhathi se-valve nokuthi sisebenza kanjani

Idizayini yenjini yokushaywa unhlangothi ezine, esebenza kumgomo wokukhishwa kwamandla ngesikhathi sokusha kwenhlanganisela kaphethiloli nophethiloli, ifaka indlela eyodwa ebalulekile, ngaphandle kwaleyo yunithi engakwazi ukusebenza. Le yindlela yokusabalalisa isikhathi noma igesi.

Ezinjini eziningi ezijwayelekile, ifakwe ekhanda lesilinda. Imininingwane eminingi mayelana nokwakheka kwemishini ichazwe ku- isihloko esihlukile... Manje sizogxila ekutheni siyini isikhathi se-valve, nokuthi umsebenzi wayo uzithinta kanjani izinkomba zamandla ezimoto nokusebenza kahle kwawo.

Siyini isikhathi se-valve yenjini

Kafushane ngomshini wesikhathi uqobo. I-crankshaft nge-drive drive (ezinjini eziningi zangaphakathi zomlilo zangaphakathi, kufakwa iketango esikhundleni sebhande elenziwe ngerabha) lixhunywe ku camshaft. Lapho umshayeli eqala injini, i-starter ishintsha iflwheel. Yomibili imiphini iqala ukuzungeza ngokuvumelanayo, kepha ngejubane elihlukile (ngokuyisisekelo, ekuguqulweni okukodwa kwe-camshaft, i-crankshaft yenza izinguquko ezimbili).

Kunamakhamu akhethekile amise okweconsi ku-camshaft. Njengoba isakhiwo sizungeza, i-cam iphusha isiqu se-valve esilayishwe entwasahlobo. I-valve iyavula, ivumela ingxube kaphethiloli womoya ukuthi ingene kwisilinda noma iqede inqwaba ye-exhaust.

Isigaba sokusabalalisa igesi yisona sikhathi lapho i-valve iqala ukuvula ukungena / ukuphuma ngaphambi komzuzu lapho ivala ngokuphelele. Unjiniyela ngamunye osebenza ekwakhiweni kweyunithi yamandla abale ukuthi ubude bokuvula i-valve kufanele bube yini, nokuthi uzohlala uvule isikhathi esingakanani.

Ithonya lesikhathi se-valve ekusebenzeni kwenjini

Ngokuya ngemodi esebenza ngayo injini, ukusatshalaliswa kwegesi kufanele kuqale noma kusenesikhathi noma kamuva. Lokhu kuthinta ukusebenza kahle kweyunithi, umnotho wayo kanye ne-torque ephezulu. Lokhu kungenxa yokuthi ukuvulwa / ukuvalwa okufika ngesikhathi kwamanani okudla nokhipha ukhiye kubalulekile ekusebenziseni amandla akhishwe ngesikhathi somlilo we-HVAC.

Uma i-valve yokungenisa iqala ukuvula ngomzuzu ohlukile lapho ipiston yenza ukushaywa kokudla, khona-ke ukugcwaliswa okungalingani kwe-cylinder cavity nengxenye entsha yomoya kuzokwenzeka futhi uphethiloli uzoxubana kakhulu, okuzoholela ekushiseni okungaphelelanga kwenhlanganisela.

Ngokuqondene ne-valve yokukhipha, akufanele futhi ivule ngaphambi kokuthi i-piston ifinyelele esikhungweni esisezingeni eliphansi, kepha hhayi ngemuva nje kokuthi iqale ukushaya phezulu. Esimweni sokuqala, ukucindezelwa kuzokwehla, futhi ngayo imoto izolahlekelwa amandla. Esikhathini sesibili, imikhiqizo yomlilo nevalvu evaliwe izodala ukumelana ne-piston, eqale ukukhuphuka. Lokhu umthwalo owengeziwe kumshini we-crank, ongalimaza ezinye izingxenye zawo.

Ukusebenza okwanele kweyunithi yamandla, isikhathi esihlukile se-valve siyadingeka. Ngemodi eyodwa, kubalulekile ukuthi ama-valve avulwe ekuqaleni futhi avale kamuva, nakwabanye, ngokufanayo. Ipharamitha yokugqagqana nayo ibaluleke kakhulu - noma ngabe womabili ama-valve azovulwa ngasikhathi sinye.

Ama-motors amaningi ajwayelekile anesikhathi esimisiwe. Injini enjalo, kuya ngohlobo lwe-camshaft, izosebenza kahle kakhulu kwimodi yezemidlalo noma ngokushayela okulinganisiwe ngama-revs aphansi.

Namuhla, izimoto eziningi eziphakathi nendawo kanye ne-premium ifakwe ama-motors, uhlelo lokusabalalisa igesi olungashintsha eminye imingcele yokuvulwa kwe-valve, ngenxa yokuthi kukhona ukugcwaliswa okuphezulu kwekhwalithi nokufaka amasilinda ngejubane le-crankshaft ehlukile.

Nakhu ukuthi isikhathi kufanele senziwe kanjani ngejubane elihlukile lenjini:

1. Idling idinga izinto ezibizwa ngokuthi izigaba ezincane. Lokhu kusho ukuthi ama-valve aqala ukuvula ngokuhamba kwesikhathi, futhi isikhathi sokuvala kwawo, kunalokho, sisekuqaleni. Akunasimo esivulekile ngasikhathi sinye kule modi (womabili ama-valve ngeke avulwe ngasikhathi sinye). Lapho ukujikeleza kwe-crankshaft kungabalulekanga kangako, ngesikhathi sokugqagqana kwesigaba, amagesi okukhipha angangena kokuphindaphindwayo kokungenayo, kanye nomthamo othile we-VTS ungene esikhungweni.
2. Imodi enamandla kakhulu - idinga izigaba ezibanzi. Le yimodi lapho, ngenxa yejubane elikhulu, ama-valve anendawo emfushane evulekile. Lokhu kuholela eqinisweni lokuthi ngesikhathi sokushayela kwezemidlalo, ukugcwaliswa nokungeniswa komoya kwamasilinda kwenziwa kabi. Ukulungisa lesi simo, isikhathi se-valve kufanele sishintshwe, okungukuthi, ama-valve kufanele avulwe ngaphambi kwesikhathi, futhi ubude bawo kulesi sikhundla kufanele bukhuphuke.

Lapho bethuthukisa ukwakhiwa kwezinjini ezine-valve valve timing eguquguqukayo, onjiniyela bacabangela ukuncika komzuzu wokuvula we-valve kusivinini secrankshaft. Lezi zinhlelo eziyinkimbinkimbi zivumela imoto ukuba isebenzisane ngezindlela eziningi ngangokunokwenzeka ngezitayela ezahlukene zokugibela. Ngenxa yalokhu kuthuthukiswa, iyunithi ikhombisa ububanzi obuningi bamathuba:

• Ekuvuseleleni okuphansi, imoto kufanele ibe yintambo;
• Lapho ama-revs enyuka, akufanele alahlekelwe amandla;
• Akunandaba noma iyiphi indlela esebenza ngayo injini yomlilo yangaphakathi, ukonga uphethiloli, kanye nayo nobungani bezokuthutha kwezemvelo, kufanele kube sezingeni eliphakeme kakhulu kunawo wonke weyunithi ethile.

Yonke le mingcele ingashintshwa ngokushintsha ukwakheka kwama-camshafts. Kodwa-ke, kulokhu, ukusebenza kahle kwezimoto kuzoba nomkhawulo wayo kwimodi eyodwa kuphela. Kuthiwani ngemoto engashintsha iphrofayli iyodwa kuye ngenani lezinguquko ze-crankshaft?

Isikhathi se-valve esiguqukayo

Umqondo ngokwawo wokushintsha isikhathi sokuvula i-valve ngesikhathi sokusebenza kweyunithi yamandla awumusha. Lo mbono wavela ngezikhathi ezithile ezingqondweni zonjiniyela ababesathuthukisa izinjini zomoya.

Ngakho-ke, enye yalezi zinguquko yabizwa ngegiya likaStevenson. Umshini washintsha isikhathi somusi ongena kwisilinda esisebenzayo. Umbuso wawubizwa nge- "cut cut". Lapho lo mshini uvuselelwa, ingcindezi yaqondiswa kabusha ngokuya ngokwakhiwa kwemoto. Ngalesi sizathu, ngaphezu kwentuthu, izitimela ezindala zesitimu nazo zazikhipha umusi lapho isitimela sikhona.

Umsebenzi wokushintsha isikhathi se-valve nawo wenziwa ngamayunithi ezindiza. Ngakho-ke, imodeli yokulinga yenjini ye-V-8 evela enkampanini iClerget-Blin enamandla angama-200 amahhashi ingashintsha le pharamitha ngenxa yokuthi ukuklanywa komshini kufaka phakathi i-camshaft eslayishayo.

Futhi ku-motor ye-Lycoming XR-7755, kwafakwa ama-camshafts, lapho kwakukhona khona amakhamera amabili ahlukene nge-valve ngayinye. Idivayisi yayine-mechanical drive, futhi yenziwa yasebenza ngumshayeli wendiza uqobo. Angakhetha enye yezindlela ezimbili ngokuya ngokuthi ubedinga ukuthatha indiza aye esibhakabhakeni, abaleke ekujaheni, noma avele andize kwezomnotho.

Ngokuqondene nemboni yezimoto, onjiniyela baqala ukucabanga ngokusetshenziswa kwalo mbono emuva kuma-20s wekhulu elidlule. Isizathu kube ukuvela kwezimoto ezihamba ngesivinini esiphezulu ezifakwe ezimotweni zezemidlalo. Ukwanda kwamandla kumayunithi anjalo kunomkhawulo othile, yize iyunithi ingahle ivuleke nangaphezulu. Ukuze imoto ibe namandla athe xaxa, ekuqaleni kwanyuswa ivolumu yenjini kuphela.

Owokuqala ukwethula isikhathi se-valve eguquguqukayo kwakungu-Lawrence Pomeroy, owayesebenza njengomklami omkhulu wenkampani yezimoto iVauxhall. Wadala imoto lapho kufakwa khona i-camshaft ekhethekile kumshini wokusabalalisa igesi. Ama-cams akhe amaningi ayeneziqoqo eziningi zamaphrofayili.

Uhlobo olungu-4.4-litre H-Type, kuya ngejubane le-crankshaft nomthwalo elihlangabezane nawo, lingahambisa i-camshaft eduze kwe-longitudinal axis. Ngenxa yalokhu, isikhathi nokuphakama kwama-valve kwaguqulwa. Njengoba le ngxenye ibinemikhawulo ekuhambeni, ukulawulwa kwesigaba nakho bekunamikhawulo.

UPorsche naye wayebandakanyekile emcabangweni ofanayo. Ngo-1959, kwanikezwa ilungelo lobunikazi "lamakhamera ahlukanisayo" we-camshaft. Lokhu kuthuthukiswa bekufanele kushintshe ukuphakama kwe-valve, futhi ngasikhathi sinye, isikhathi sokuvula. Ukuthuthukiswa kwahlala esigabeni sephrojekthi.

Umshini wokuqala wokulawula isikhathi we-valve osebenzayo wasungulwa yiFiat. Lokhu kusungulwa kwakhiwa nguGiovanni Torazza ngasekupheleni kweminyaka yama-60s. Umshini wasebenzisa ama-hydraulic pusher, aguqula iphuzu le-pivot ye-valve tappet. Idivayisi isebenze ngokuya ngejubane lenjini nengcindezi kokuphindwe kaningi kokungenayo.

Kodwa-ke, imoto yokuqala yokukhiqiza enezigaba eziguquguqukayo ze-GR yayivela kwa-Alfa Romeo. Imodeli yesicabucabu yango-1980 yathola indlela esebenza ngogesi eshintsha izigaba kuye ngezindlela zokusebenza kwenjini yomlilo yangaphakathi.

Izindlela zokushintsha ubude nobubanzi besikhathi se-valve

Namuhla kunezinhlobo eziningi zezinqubo ezishintsha umzuzu, isikhathi nokuphakama kokuvulwa kwe-valve:

1. Ngendlela elula kakhulu, lokhu kuyi-clutch ekhethekile efakwe ku-timing mechanism drive (phase shifter). Ukulawulwa kwenziwa ngenxa yomthelela wokubacindezela kumshini wokuphatha, futhi ukulawula kwenziwa nge-elekthronikhi. Lapho injini idling, i-camshaft isendaweni yayo yangempela. Ngokushesha nje lapho ama-revs enyuka, i-elekthronikhi iphendula kule parameter futhi isebenze ama-hydraulic, ajikelezisa i-camshaft kancane maqondana nendawo yokuqala. Ngenxa yalokhu, ama-valve avuleka ngaphambi kwesikhathi, okwenza kube lula ukugcwalisa amasilinda ngengxenye entsha ye-BTC.
2. Ukushintsha iphrofayili yekham. Lokhu kuyintuthuko ebisetshenziswa ngabashayeli isikhathi eside. Ukufaka i-camshaft ngamakhamera angajwayelekile kungenza iyunithi isebenze kahle nge-rpm ephakeme. Kodwa-ke, ukuthuthuka okunjalo kufanele kwenziwe ngumakhenikha onolwazi, okuholela ekuchithekeni okuningi. Ezinjini ezinesistimu ye-VVTL-i, ama-camshafts anamasethi amaningana ama-cams anamaphrofayili ahlukile. Lapho injini yomlilo yangaphakathi idling, izinto ezijwayelekile zenza umsebenzi wazo. Lapho nje i-crankshaft rpm idlula idlula uphawu oluyizinkulungwane eziyisithupha, i-camshaft igudluka kancane, ngenxa yokuthi elinye iqoqo lamakhamera liqala ukusebenza. Inqubo efanayo yenzeka lapho injini ijikeleza ifinyelela ku-6 ayizinkulungwane, futhi isethi yesithathu yamakhamera iqala ukusebenza, okwenza izigaba zibanzi kakhulu.
3. Shintsha ekuvulekeni kwe-valve ukuphakama. Lokhu kuthuthukiswa kukuvumela ukuthi ushintshe ngasikhathi sinye izindlela zokusebenza zesikhathi, kanye nokukhipha i-valve mpintsha. Ezinhlelweni ezinjalo, ukucindezela i-accelerator pedal kusebenze umshini womshini othinta amandla okuvula ama-valve wokudla. Lolu hlelo lunciphisa ukusetshenziswa kukaphethiloli cishe ngamaphesenti ayi-15 futhi lukhulisa amandla aleyunithi ngenani elifanayo. Kumamori wesimanjemanje, hhayi i-mechanical, kodwa i-analogue ye-electromagnetic isetshenziswa. Ubuhle benketho yesibili ukuthi i-elektroniki iyakwazi ukushintsha kahle futhi ngokushelela izindlela zokuvula i-valve. Ukuphakama kokuphakama kungasondela ezikhathini ezifanele futhi zokuvula kungabanzi kunezinguqulo zangaphambilini. Ukuthuthuka okunjalo ukonga uphethiloli kungahle kucishe amanye amasilinda (ungavuli amanye ama-valve). Lezi zinjini zisebenzisa uhlelo lapho imoto ima, kodwa injini yomlilo yangaphakathi ayidingi ukucishwa (ngokwesibonelo, erobhothini) noma lapho umshayeli ebambezela imoto ngenjini yomlilo yangaphakathi.

Kungani ushintsha isikhathi se-valve

Ukusetshenziswa kwezinqubo ezishintsha isikhathi se-valve kuvumela:

• Kusebenza kahle kakhulu ukusebenzisa insiza yeyunithi yamandla ngezindlela ezahlukahlukene zokusebenza kwayo;
• Khulisa amandla ngaphandle kwesidingo sokufaka i-camshaft yangokwezifiso;
• Yenza imoto ibe ukonga ngokwengeziwe;
• Nikeza ngokugcwalisa okuphumelelayo kanye nomoya omncane wamasilinda ngesivinini esikhulu;
• Khulisa ubungani bezokuthuthwa kwemvelo ngenxa yomlilo osebenza kahle wenhlanganisela kaphethiloli womoya.

Njengoba izindlela ezahlukahlukene zokusebenza zenjini yomlilo yangaphakathi zidinga imingcele yazo yesikhathi se-valve, kusetshenziswa izindlela zokushintsha i-FGR, umshini ungahambelana nemingcele efanelekayo yamandla, i-torque, ubungani bezemvelo nomnotho. Inkinga kuphela okungekho mkhiqizi ongayixazulula kuze kube manje izindleko eziphezulu zedivayisi. Uma kuqhathaniswa ne-motor ejwayelekile, i-analogue efakwe ngendlela efanayo izobiza cishe cishe kabili.

Abanye abashayeli basebenzisa amasistimu wokushintsha isikhathi we-valve ukukhulisa amandla emoto. Kodwa-ke, ngosizo lwebhande lesikhathi eliguquliwe, akunakwenzeka ukukhama okuphezulu kwiyunithi. Funda ngamanye amathuba lapha.

Ekuphetheni, sinikela ngosizo olubonakalayo oluncane ekusebenzeni kohlelo lokushintsha isikhathi se-valve:

Isistimu yesikhathi se-valve eguquguqukayo esebenzisa isibonelo se-CVVT

Imibuzo nezimpendulo:

Yini ebizwa ngesigaba sokusabalalisa igesi? Lesi yisikhathi lapho i-valve (i-inlet noma i-outlet) ivula/ivala. Leli gama livezwa ngamadigri okujikeleza kwe-crankshaft yenjini.

Чiyasithinta isikhathi se-valve? Isikhathi se-valve sithintwa imodi yokusebenza yenjini. Uma singekho isishintshi sesigaba ngesikhathi, umphumela omkhulu utholakala kuphela kuhlu oluthile lwezivinini zenjini.

Kungani udinga umdwebo wesikhathi se-valve? Leli shadi libonisa ukuthi amasilinda agcwaliswa kahle, ashiswe futhi ahlanzwe kanjani ebangeni elithile le-rpm. Ikuvumela ukuthi ukhethe kahle isikhathi se-valve.