Lapho injini isebenza, iphefumula umoya omusha futhi ikhipha amagesi akhipha umoya ashisayo izikhathi eziyizinkulungwane njalo ngomzuzu owodwa. I-symphony yemishini elawula lokhu kuphefumula yaziwa ngokuthi isitimela se-valve. Le ndatshana ikufanele ngempela ukuyifunda ngoba ukwazi kahle umakhenikha we-valvetrain kukunikeza inzuzo enkulu ekuxilongweni nasekulungiseni. Ngokuqonda indlela efanele lungisa i-valve izingxenye kanye nokubona umehluko obalulekile phakathi kweziphakamisi eziqinile nezigcwele uketshezi, ungavimbela ukuwohloka okumba eqolo futhi ugcine imishini yakho isebenza ngenzuzo enkulu.
Iyini ngempela i-tappet enjinini evuthayo yangaphakathi?
Uma udiliza ibhulokhi yenjini yakudala, uzothola uxhaxha lwezinkomishi zensimbi eziyisilinda. A i-tappet, nayo evame ukubizwa ngokuthi a umphakamisi noma a umlandeli we-cam, ungumuntu ophakathi obalulekile ekwakhiweni kwe-valvetrain. Ihlala ngokuvikelekile ngaphakathi kwebhore efakwe ngomshini etholakala kubhulokhi yenjini noma ikhanda lesilinda.
Umsebenzi oyinhloko we-tappet uwukwenza ngokuqhubekayo nangokushelela landela ikhamera njengoba ijikeleza. Njengoba umumo we-eccentric we-cam uzungeza, i-tappet igibela iphrofayili yayo. I-tappet ithatha lokho kunyakaza okujikelezayo okujikelezayo futhi ikuhumushe khona manjalo ibe ukunyakaza okuqondile, okuya phezulu naphansi. Ngaphandle kwale ngxenye ehlala isikhathi eside ngendlela emangalisayo esebenza njengesilondolozi, ukushwibeka okunamandla kwekhamera yokuphotha kungacekela phansi insimbi ethambile yezinye izingxenye.
Ngoba i phezulu kwe-tappet ibhekene nokuguga okukhulu, imvamisa iqinile noma yenziwa ngezinto ezingagugi kakhulu. Eqinisweni, lapho senza amathuluzi okusika akhethekile e-Drillstar, njenge I-Cemented Carbide Insert, sisebenzisa izimiso zensimbi ezifanayo ncamashi zokuqina okwedlulele ukuze siqinisekise ukuthi ithuluzi ledlula izinto ezilimazayo elizisikayo.
Ikhamera isenza kanjani isitimela esisele esisele?
Yonke inqubo yokuphefumula iqala phansi enjini ngokusindayo i-crankshaft. Njengoba i-crankshaft ijikeleza, isebenzisa ibhande lesikhathi eliwugqinsi noma iketango lensimbi ukushayela cam shaft. Eduze kwalo mphini kunamaqhubu amaningana amise okweqanda aziwa ngokuthi ama-lobes. Ngamunye cam lobe yakhelwe ngokwezibalo ukulawula ngqo ukuthi isilinda esithile siphefumula nini.
Njengoba i-shaft ijikeleza, iphuma ngaphandle lobe iphusha ngamandla ebusweni be-tappet. Emiklamo emidala ye-pushrod, i-tappet iphoqa insimbi ende induku yokuphusha phezulu. Lokhu kukhuphuka induku yokuphusha bese izungeza insimbi ingalo ye-rocker. Uhlangothi oluphambene lwe ingalo ye-rocker ishwibeka phansi bese icindezela kanzima phezulu kwesiqu se-valve.
La mandla abheke phansi kufanele abe namandla ngokwanele ukuze acindezele esindayo, esigoqiwe iziphethu ze-valve futhi baphushe ngokomzimba okwendabuko i-poppet isitayela i-valve vula. Uma isiqongo sekhamera sizungeza ukudlula i-tappet, amandla amakhulu agciniwe ku- iziphethu ze-valve ivala ngobudlova i-valve futhi, ivale ngokuphelele igumbi elivuthayo. Ukuze ngempumelelo shukumisa lokhu chungechunge ngokushelela ku-6,000 RPM kudinga imishini engenasici.
Kungani ukucaciswa kwe-valve okunembile kubaluleke kakhulu?
Ukushisa kushintsha yonke into kumakhenikha. Lapho injini ivutha futhi ifinyelela izinga lokushisa elilungile lokusebenza, ukushisa okukhulu kubangela ukuthi izingxenye zensimbi zande ngokomzimba. I isilinda, ama-valve, ne-block konke kuyakhula ngosayizi. Uma onjiniyela bakha i-valvetrain ngegebe eliyiziro lapho injini ibanda, lokhu kwanda okushisayo bekungabangela izingxenye ukuthi zibophe ziqine.
Uma ingekho indawo esele ukuze insimbi yande, izingxenye ezikhulayo zizobamba i-valve ivuleke kancane ngisho nalapho kufanele ivaleke ngokugcwele. Lokhu kulahlekelwa kwe-tight seal kubhubhisa injini ngokushesha ukucindezela. Okubi nakakhulu, amagesi avuthayo ashisa kakhulu azokhanyisa indlela yawo adlule igebe elincane, ashise imbobo ngokoqobo emaphethelweni onqenqema. i-valve yokukhipha.
Ukuvimbela le nhlekelele, oomakhenikha bashiya igebe elincane, elibaliwe ekuxhumaneni. Leli gebe elibalulekile libizwa ngokuthi ukususwa kwe-valve. Ukugcina okuphelele imvume kuyisisekelo esiphelele sezinga ukunakekelwa kwemoto. Uma i imvume iqine kakhulu, ushisa ama-valve. Ngokuphambene, uma i- imvume ixega kakhulu, izingxenye ziyangqimuzana. Lesi simo esixegayo sidala ukucasuka, okusheshayo umsindo wokushaya futhi kuholela ekugqokeni okubi, ngaphambi kwesikhathi ebusweni bekhamera.
Ziyini iziphakamisi ezinama-hydraulic, futhi zinciphisa kanjani ukulungiswa kwemoto?
Ukuze kuqedwe umsebenzi oyisicefe wokuhlala ulungisa izindawo ezivulekile ngesandla, kwasungulwa onjiniyela abahlakaniphile ama-hydraulic lifters. A i-hydraulic tappet isebenzisa ukunikezwa kukawoyela ocindezelwe yinjini ukuze ithathe ngokuzenzakalelayo futhi ngokuqhubekayo noma yikuphi ukuntenga ohlelweni.
Ngaphakathi komzimba ka i-hydraulic tappet, kukhona ipiston yangaphakathi encane kanye nevalvu yokuhlola indlela eyodwa. Lapho ikhamera izungeza futhi isusa ukucindezela kusiphakamisi, uwoyela wenjini ocindezelwe uyangena ngaphakathi. Lokhu umfutho we-hydraulic impompa i-piston yangaphakathi phezulu kuze kube yilapho yonke indawo evulekile isiphelile.
Ngoba ompompi we-hydraulic zivumelane ngokuguquguqukayo ekushintsheni kwezinga lokushisa nokuguga ngokomzimba, zigcina ziro ngokuphelele ukuqhuma kwe-valve ngezikhathi zonke. Ama-hydraulic lifters dala umshini othule kahle, osebenza kahle futhi ususe ngokuphelele isidingo sokulungisa mathupha. Kumshayeli ojwayelekile wansuku zonke, lokhu ukwethembeka "kufake futhi ukhohlwe" kuwukushintsha ngokuphelele umdlalo.
Ingabe ompompi abaqinile bezandla baqhathaniswa kanjani nokusethwa kwe-hydraulic?
Ngenkathi a i-hydraulic ukusetha akunasici emotweni yomgibeli, inobuthakathaka obuhlukile ezinhlelweni zomjaho wejubane eliphezulu. Ema-RPM adlulele, ukunyakaziswa kukawoyela ngokushesha kungabangela ukuba isiphakamisi esigcwele uketshezi “simpompe” futhi sibambe ama-valve evulekile, okuholela ekulahlekelweni kwamandla okuyinhlekelele. Ukuze ulwe nalokhu, abakhi bezinjini zomjaho bathembele kuphela kokuqinile ompompi.
Iziphakamisi eziqinile ziyilokho kanye ezizwakala sengathi—amasilinda ensimbi aqinile. Abakwazi ukuwa noma ukupompa ngaphansi kwengcindezi enkulu. Lokhu kuqina kuqinisekisa ukuthi i-valve ilandela iphrofayili yekhamera ncamashi, ngisho naku-9,000 RPM. Lokhu kuvimbela ngokuphelele isimo esiyingozi kakhulu esaziwa ngokuthi ukuntanta kwe-valve, lapho i-valve esindayo imane ingakwazi ukuvala ngokushesha ngokwanele ukuze ihambisane nekhamera yokuphotha.
Nokho, ukugijima ama-lifters aqinile kusho ukwamukela umthwalo osindayo wokulungisa. Badinga njalo, ngokucophelela imanuwali ukulungiswa kwe-tappet. Omakhenikha kufanele bavule njalo amakhava amavalvu futhi balinganise ngokomzimba igebe eliphakathi kwe ikhamera kanye ne-valve izingxenye zokuqinisekisa ukuthi ihlala ngaphakathi kokucaciswa kwefekthri.
Iyiphi indima edlalwa ama-pushrod nengalo ye-rocker kumadizayini amadala?
Uma uvula ihood emotweni yemisipha yakudala yaseMelika eyi-V8, ubheke injini ye-pushrod yendabuko ye-overhead valve (OHV). Kulesi sakhiwo, eyodwa i-camshaft ingcwatshwe ekujuleni phakathi nendawo emnyama yebhulokhi yenjini.
Ngenxa yokuthi i-camshaft ikude kakhulu namavalvu atholakala phezulu ekhanda lesilinda, injini incike ensimbi ende, engenalutho. ama-pushrods ukuvala ibanga elikhulu. Umphakamisi ugibela ikhamera ezansi ebhulokhini, ayishove induku yokuphusha phezulu, futhi induku ikhomba i-rocker phezulu phezulu.
Laba abadala ama-valvetrains zihlangene ngendlela emangalisayo futhi ziqinile ngokudumile. Bakhiqiza i-torque enkulu esezingeni eliphansi. Kodwa-ke, zonke lezo zingxenye zensimbi ezinzima, ezihambayo zenza inqwaba ye-valvetrain mass. Ukuhambisa insimbi esindayo ngokushesha kudinga amandla, futhi lobo bunzima obudlulele bukhawulela kakhulu ukuthi injini ye-pushrod ingaphenduka ngokushesha kangakanani ngaphambi kokuba izingxenye ezisindayo ziqale ukugoba nokubhampa zingalawuleki.
Ingabe imiklamo ye-overhead cam (OHC) ihluke kanjani kuzinjini ze-pushrod zendabuko?
Ukuxazulula inkinga yesisindo nokuvula isivinini esiphezulu senjini, imboni yezimoto ishintshele ku- ikhamera ephezulu umklamo. Ngokukhipha i-camshaft ebhulokhini bese beyibeka ngqo phezu kwekhanda lesilinda, onjiniyela baqeda isidingo sama-pushrod asindayo.
Ku-a ikhamera eyodwa ephezulu (sohc) isakhiwo, i-camshaft eyodwa ihlala ngqo ngaphezu kwama-valve, ngokuvamile isebenzisa encane i-rocker ukucupha zombili izinhlangothi zokuthatha nezokuqeda. Kukhamera engaphezulu ephindwe kabili ethuthuke kakhulu (dohc) ukusethwa, kunama-camshaft amabili ahlukene ebhange ngalinye lesilinda—eyodwa eye-valve yokudonsa kanye neyodwa eye-exhaust valves.
Inzuzo enkulu ye ohc futhi ngokuqondile sohc futhi dohc izakhiwo ziwukuncipha okukhulu kwezingxenye ezihambayo. Ibanga phakathi kwe- i-camshaft kanye ne-valve mfishane ngendlela emangalisayo. Ekulingiseni okuqondile izinjini zamakhamera, i-lobe icindezela iqonde phansi ngendlela yebhakede umlandeli we-cam ehlala ngqo phezu kwesiqu se-valve. Lokhu kukhanya okukhulu, sethaphu eqinile kuvumela izimoto zesimanje zemidlalo ukuthi zimemeze zidlule ku-8,000 RPM ngokuthembeka okungenasici.
Uma unesithuthuthu noma umshini osebenza kahle kakhulu onamakheshi aqinile, owenza a ukulungiswa kwe-tappet kuyikhono eliyisibopho. Umgomo uwukusetha kahle igebe ukuze uma injini ishisa, imvume ivaleke ngokwemvelo ifinyelele ku-zero ngaphandle kokubopha.
Okokuqala, kufanele uzungezise i-crankshaft eyinhloko ngesandla kuze kube yilapho eqondile ipiston usebenza ekufinyeleleni i-Top Dead Center (tdc) kuyo ukucindezela unhlangothi. Ngo tdc, ama-valve womabili avalwe ngokuphelele, futhi umphakamisi uphumule kusiyingi esiyisicaba, esiyisisekelo sekhamera. Lesi ukuphela kwendawo ephephile yokukala igebe.
Okulandelayo, uthatha ithuluzi lokulinganisa lensimbi elincanyana, elinembayo elibizwa ngokuthi a i-feeler gauge. Uyashelela i- ozizwayo iqonde phakathi kwesihloko se-valve kanye ne-rocker esebenzayo. Kufanele idlule ngokumelana nokudonsa kancane, okushelelayo. Uma a umuzwa wokuzizwa izizwa ixege kakhulu noma ibophana ngokuphelele, igebe alilungile.
Uma udinga lungisa i-tappet, ngokuvamile uthatha encane isikrufu, khulula inadi lokukhiya ku-rocker, bese uvula isikhungo esinentambo isilungisi screw kuze kube imvume ihambisana nemboni ngqo spec.
Akuwona wonke ama-lifters aqinile asebenzisa isikulufu esilula esinentambo. Izinjini eziningi zekhamera ezisebenza ngqo ezisebenza phezulu zisebenzisa iziphakamisi zamabhakede eziqinile. Kulokhu kusetha, ukuze lungisa i-valve imvume, kufanele ushintshe ngokomzimba ubukhulu bediski encane yensimbi ebizwa ngokuthi a shim.
I shim ihlala ngqo phezu kwebhakede noma ngaphansi kwayo, ihlezi phezu kwesiqu se-valve. Uma isilinganiso sakho sibonisa imvume iqine kakhulu, kufanele ususe ekhona shim futhi esikhundleni salo ufake elincanyana.
Ukushintshanisa lezi shim ngokuvamile kudinga a ithuluzi elikhethekile ukucindezela iziphethu ezisindayo phansi ukuze ukhiphe ngokucophelela ushizi ngozibuthe. Kuyinqubo eyisicefe, enezibalo eziphezulu. Kufanele ulinganise ngokucophelela i-shim endala, ubale umehluko odingekayo, bese ufaka entsha. Kodwa-ke, uma usumisiwe, idizayini ye-shim-under-bucket izinze ngendlela emangalisayo futhi ayivamisile ukuphuma ekulungiseni.
Kwenzekani ngesikhathi i-valve igqagqene phakathi kwe-inlet ne-exhaust strokes?
Isikhathi senjini siwumdanso oxake ngendlela emangalisayo, onesivinini esikhulu. Kukhona isikhathi esifushane kakhulu, esakhiwe kakhulu lapho i- ipiston isondela phezulu kwesilinda ekugcineni kwe qeda isifo sohlangothi, lapho kokubili indawo yokungena valve kanye i-valve yokukhipha empeleni avuliwe ngenkani ngesikhathi esifanayo.
Le ngxenye ethize yomzuzwana ibizwa ngokuthi ukunqwabelana kwe-valve. Kungani ufuna ukuvula ama-valve womabili ngesikhathi esisodwa? Inakho konke okuphathelene ne-fluid dynamics. Ukushisa okuphuma ngokushesha qeda amagesi adala i-vacuum enamandla ngemva kwawo. Lo mphumela wokucosha usiza ukumunca ngokoqobo ingxube yamafutha omoya abandayo, abandayo endaweni evulekile indawo yokungena imbobo, igcwalisa isilinda ngokuphumelelayo kakhulu.
I-spring-loaded yendabuko i-poppet i-valve ikuphatha kahle lokhu. Kodwa-ke, amanye ama-superbike ase-Italy angavamile athatha isinyathelo esengeziwe ngokusebenzisa ayinkimbinkimbi kakhulu ama-valve e-desmodromic. Isistimu ye-desmodromic isebenzisa ingalo ye-rocker yesibili, ezinikele ukuze idonse i-valve ngokoqobo, isuse ngokuphelele iziphethu futhi iqinisekise ngokuphelele ukuthi i-valve ivala lapho ikhamera isho khona, isuse ngokuphelele noma yiliphi ithuba lokuntanta.
Cabanga ngokucindezeleka okukhulu okwenzeka ngaphakathi kwekhanda lesilinda. Ivalvu yensimbi ende, ezacile kufanele isyibilikele phezulu naphansi izikhathi eziyizigidi ngaphandle kokuvuza neconsi elilodwa likawoyela noma ilahlekelwe ukugxila kwayo okuphelele. Ithusi noma ithusi i-valve guide ishelela phakathi kufanele yenziwe ngomshini ukuze ikwazi ukubekezelela izinto ezincane nezingenasici.
Izihlalo eziyisiyingi zensimbi lapho amavalvu evaleka khona ukuze avale isilinda kufanele ihambisane kahle ne-engeli yobuso be-valve. Uma ecishiwe ngisho nangengxenye yedigri, amagesi ashisayo azoshisa insimbi ngokushesha. Yilapho kanye ukukhiqizwa kwe-CNC okuthuthukisiwe namathuluzi okusika ama-premium okuba amaqhawe aphelele embonini yezimoto.
Kwa-Drillstar, sinjiniyela amathuluzi abukhali ngendlela emangalisayo, aqinile adingekayo ukuze kwakhiwe lezi zimangaliso zesimanje. Lapho umkhiqizi wenjini edinga ukubhoboza imbobo yokuqondisa i-valve engenasici, bathembela kwethuAma-Modular Indexable Reamers (Amathuluzi Okubhoring Okunemba Kakhulu & Amathuluzi Wokuvuselela) ukufeza isiphetho esifana nesibuko. Njengoba nje umakhenikha oyinhloko ethembela kushimu onembayo ukuze asethe okulungile ukususwa kwe-tappet, izimboni zezimoto zithembele kumathuluzi ethu aqinile e-carbide ukuze aqinisekise ukuthi i-camshaft spin ngokukhululekile futhi injini uphefumula kalula.
Isifinyezo: Okubalulekile Okuthathwayo Kwe-Mastering Valvetrain Mechanics
Ukuqonda oomakhenikha abanonya, abanesivinini esikhulu ngaphakathi kwemoto kukunikeza inhlonipho ejulile ngobunjiniyela besimanje kanye nokukhiqiza. Nawa amaphuzu abaluleke kakhulu okufanele uwakhumbule:
- I-Middleman: I i-tappet isebenza njengesivimbeli esibalulekile, esingagugi phakathi kwekhamera ephotha ngamandla kanye nayo yonke i-valvetrain.
- Ukwandiswa Kokushisa: Ngoba izinsimbi zanda kakhulu lapho kushisa, zigcina zifanelekile ukususwa kwe-valve kuyisidingo esiphelele sokuvimbela ama-valve ashile futhi alahleke ukucindezela.
- Ukugcinwa Kweziro: Ama-hydraulic lifters sebenzisa ngokugqamile uwoyela wenjini ecindezelwe ukuze ugcine ngokuzenzakalelayo uziro ukuqhuma, ususa isidingo soku imanuwalily lungisa i-valve.
- Ukuqina komjaho: Izinjini ezihamba phambili zidinga iziphakamisi eziqinile ukuze zigweme ngokuphelele ingozi ukuntanta kwe-valve ngama-RPM amakhulu.
- Ukunciphisa Isisindo: Ukusuka kumiklamo ye-pushrod esindayo kuye kweyesimanjemanje ikhamera ephezulu ukusetha kunciphisa kakhulu ukunyakaza kwesisindo, okuvumela injini ukuthi ivuleke ngokushesha okukhulu.
- Ukunemba Kuyikho Konke: Ukuthi uslayida ngokucophelela a i-feeler gauge phakathi kuka-a ikhamera kanye ne-valve noma sisebenzisa amathuluzi okusika e-CNC athuthukisiwe ukwenza a i-valve guide, ukunemba okuphelele kudinga impumelelo.
Ngokuthatha isikhathi sokuqonda kahle ukuthi kwenziwa kanjani vula i-valve kahle futhi nini lungisa i-tappet ngokufanelekile, uqinisekisa ukuthi imishini yakho esindayo iletha amandla amahhashi aphezulu, ukwethembeka okuphelele, nempilo ende, enenzuzo yesevisi.
