Ma brake pad ndi mbali zofunika kwambiri zotetezera mu ma brake system, zomwe zimagwira ntchito yofunika kwambiri pamtundu wa brake effect, ndipo ma brake pad amateteza anthu ndi magalimoto (ndege).
Choyamba, chiyambi cha ma brake pads
Mu 1897, HerbertFrood adapanga ma brake pads oyamba (pogwiritsa ntchito ulusi wa thonje monga kulimbikitsa ulusi) ndipo adawagwiritsa ntchito m'ngolo zokokedwa ndi akavalo ndi magalimoto oyambirira, pomwe kampani yotchuka ya Ferodo inakhazikitsidwa. Kenako mu 1909, kampaniyo inapanga mabuleki oyamba olimba a asibesitosi padziko lapansi; Mu 1968, ma brake pads oyamba padziko lonse lapansi adapangidwa, ndipo kuyambira pamenepo, zida zogundana zayamba kupanga kukhala zopanda asbestos. Kunyumba ndi kunja anayamba kuphunzira zosiyanasiyana ulusi m'malo asibesito monga zitsulo CHIKWANGWANI, galasi CHIKWANGWANI, CHIKWANGWANI aramid, mpweya CHIKWANGWANI ndi ntchito zina mu zipangizo kukangana.
Chachiwiri, gulu la ma brake pads
Pali njira ziwiri zazikulu zogawira zida za brake. Limodzi limagawidwa ndi kugwiritsa ntchito mabungwe. Monga zida zama brake zamagalimoto, zida zama brake sitima ndi zida zoboola ndege. Njira yamagulu ndi yosavuta komanso yosavuta kumvetsetsa. Imodzi imagawidwa molingana ndi mtundu wa zinthu. Njira yogawa iyi ndi yasayansi kwambiri. Zipangizo zamakono zamabuleki zimaphatikizanso magulu atatu otsatirawa: zida zopumira zopangira utomoni (zida za asibesitosi, zida zomabuleki za asibesitosi, zida zoboola pamapepala), zida zoboola zitsulo za ufa, zida zoboola kaboni/carbon composite ndi zida za ceramic zochokera ku ceramic.
Chachitatu, zida zama brake zamagalimoto
1, mtundu wa zida zama brake zamagalimoto molingana ndi zinthu zopangira ndizosiyana. Zitha kugawidwa mu pepala la asibesitosi, pepala la theka-zitsulo kapena pepala lochepa lachitsulo, NAO (asibesitosi wopanda kanthu) pepala, pepala la carbon ndi pepala la ceramic.
1.1.Chitsamba chaasibesitosi
Kuyambira pachiyambi, asibesitosi yakhala ikugwiritsidwa ntchito ngati zopangira zopangira ma brake pads, chifukwa fiber ya asbestosi imakhala ndi mphamvu zambiri komanso kukana kutentha kwambiri, kotero imatha kukwaniritsa zofunikira za ma brake pads ndi clutch discs ndi gaskets. Chingwechi chimakhala ndi mphamvu zolimba, zimatha kufanana ndi zitsulo zapamwamba kwambiri, ndipo zimatha kupirira kutentha kwa 316 ° C. Komanso, asibesitosi ndi wotsika mtengo. Amachokera ku amphibole ore, omwe amapezeka mochuluka m'mayiko ambiri. Zida zolimbana ndi asibesitosi makamaka zimagwiritsa ntchito ulusi wa asibesitosi, womwe ndi hydrated magnesium silicate (3MgO · 2SiO2 · 2H2O) monga chitsulo chothandizira. Chojambulira chosinthira kugundana chimawonjezeredwa. Chida chophatikizika cha organic matrix chimapezedwa ndikukanikiza zomatira mu nkhungu yosindikizira yotentha.
Zaka za m'ma 1970 zisanachitike. Mapepala amtundu wa asibesitosi amagwiritsidwa ntchito kwambiri padziko lapansi. Ndipo analamulidwa kwa nthawi yaitali. Komabe, chifukwa cha kuchepa kwa kutentha kwa asbestos. Kutentha kwa mkangano sikungatheke msanga. Zimapangitsa kuti kutentha kwa kutentha kwa malo ophwanyika kukhale kolimba. Wonjezerani kuvala zakuthupi. M'menemo. Madzi akristalo a ulusi wa asbestos amalowa pamwamba pa 400 ℃. Katundu wa kukangana amachepetsedwa kwambiri ndipo kuvala kumawonjezeka kwambiri ikafika 550 ℃ kapena kupitilira apo. Madzi a kristalo atayika kwambiri. Kuwongolako kumatayika kwathunthu. Chofunika kwambiri. Zimatsimikiziridwa mwachipatala. Asibesitosi ndi chinthu chomwe chimawononga kwambiri ziwalo zopuma za anthu. July 1989. Bungwe la US Environmental Protection Agency (EPA) linalengeza kuti lidzaletsa kuitanitsa, kupanga, ndi kukonza zinthu zonse za asibesitosi pofika 1997.
1.2, semi-zitsulo pepala
Ndi mtundu watsopano wa zinthu kukangana anayamba pa maziko a zinthu organic mikangano ndi chikhalidwe ufa zitsulo mikangano zakuthupi. Amagwiritsa ntchito ulusi wachitsulo m'malo mwa ulusi wa asibesitosi. Ndizinthu zosagwirizana ndi asibesitosi zomwe zidapangidwa ndi American Bendis Company koyambirira kwa 1970s.
"Semi-metal" hybrid brake pads (Semi-met) amapangidwa makamaka ndi ubweya wachitsulo wachitsulo monga kulimbikitsa ulusi komanso kusakaniza kofunikira. Ma asbestos ndi non-asbestos organic brake pads (NAO) amatha kusiyanitsa mosavuta ndi mawonekedwe (ulusi wabwino ndi tinthu ting'onoting'ono), komanso amakhala ndi maginito ena.
Zipangizo za semi-metallic friction zili ndi izi:
(l) Chokhazikika kwambiri pansi pa coefficient of friction. Sizimapanga kuwonongeka kwa kutentha. Kukhazikika kwabwino kwamafuta;
(2) Kukana kuvala bwino. Moyo wautumiki ndi nthawi 3-5 kuposa zida za asibesitosi;
(3) Kuchita bwino kwa mikangano pansi pa katundu wambiri ndi kukhazikika kwachitsulo;
(4) Good matenthedwe madutsidwe. Kutentha kwa kutentha kumakhala kochepa. Makamaka oyenera ang'onoang'ono chimbale ananyema mankhwala;
(5) Phokoso laling'ono la braking.
United States, Europe, Japan ndi mayiko ena adayamba kulimbikitsa kugwiritsa ntchito madera akuluakulu m'ma 1960. Kukana kuvala kwa pepala la theka-zitsulo ndipamwamba kuposa 25% kuposa pepala la asibesitosi. Pakadali pano, ili pamalo apamwamba pamsika wa brake pad ku China. Ndipo magalimoto ambiri aku America. Makamaka magalimoto ndi okwera ndi onyamula katundu. Semi-metal brake lining yapitilira 80%.
Komabe, mankhwalawa alinso ndi zofooka zotsatirazi:
(l) Chitsulo chachitsulo ndi chosavuta kuchita dzimbiri, chosavuta kumangirira kapena kuwononga awiriwo pambuyo pa dzimbiri, ndipo mphamvu ya mankhwalawa imachepetsedwa pambuyo pa dzimbiri, ndipo kuvala kumawonjezeka;
(2) High matenthedwe madutsidwe, amene n'zosavuta chifukwa ananyema dongosolo kutulutsa mpweya kukana pa kutentha, chifukwa mu wosanjikiza mikangano ndi zitsulo mbale detachment:
(3) Kuuma kwakukulu kumawononga zinthu zapawiri, zomwe zimabweretsa macheza komanso phokoso lotsika pafupipafupi;
(4) Kuchulukana kwambiri.
Ngakhale kuti "semi-metal" ilibe zofooka zazing'ono, koma chifukwa cha kukhazikika kwake, mtengo wotsika, ndizomwe zimakondedwa kwambiri pazitsulo zamagalimoto.
1.3. filimu ya NAO
Kumayambiriro kwa zaka za m'ma 1980, padziko lonse lapansi panali zomangira zosakanizidwa zosakanizidwa zopanda asbestosi, ndiko kuti, m'badwo wachitatu wa ma brake pads opanda asbestos amtundu wa NAO. Cholinga chake ndi kupanga zofooka za zitsulo zachitsulo zomwe zimalimbikitsidwa kuti ziwonongeke, zitsulo zomwe zimagwiritsidwa ntchito ndi zomera, aramong fiber, glass fiber, ceramic fiber, carbon fiber, mineral fiber ndi zina zotero. Chifukwa chakugwiritsa ntchito ulusi wambiri, ulusi mu lining ya brake umathandizirana pakuchita bwino, ndipo ndikosavuta kupanga fomula ya lining ya brake ndikuchita bwino kwambiri. Ubwino waukulu wa NAO pepala ndi kukhalabe wabwino braking zotsatira pa kutentha otsika kapena mkulu, kuchepetsa kuvala, kuchepetsa phokoso, ndi kukulitsa moyo utumiki wa ananyema chimbale, kuimira panopa chitukuko malangizo a zinthu kukangana. Zomwe zimagwiritsidwa ntchito ndi mitundu yonse yotchuka padziko lonse lapansi ya Benz / Philodo brake pads ndi m'badwo wachitatu NAO asbestos-free organic material, yomwe imatha kuswa momasuka kutentha kulikonse, kuteteza moyo wa dalaivala, ndikuwonjezera moyo wa brake. diski.
1.4, pepala la carbon carbon
Mpweya wa carbon composite friction material ndi mtundu wa zinthu zomwe zimakhala ndi carbon fiber reinforced carbon matrix. Makhalidwe ake amakangana ndiabwino kwambiri. Kachulukidwe kochepa (zitsulo zokha); Mulingo wapamwamba kwambiri. Lili ndi mphamvu yotentha kwambiri kuposa ufa wazitsulo ndi zitsulo; Kutentha kwakukulu; Palibe mapindikidwe, adhesion chodabwitsa. Kutentha kwa ntchito mpaka 200 ℃; Kuthamanga kwabwino komanso kuthamanga kwa magazi. Moyo wautali wautumiki. The friction coefficient imakhala yokhazikika komanso yocheperako panthawi ya braking. Mapepala a carbon-carbon composite anayamba kugwiritsidwa ntchito mu ndege zankhondo. Pambuyo pake idakhazikitsidwa ndi magalimoto othamanga a Formula 1, yomwe ndi njira yokhayo yogwiritsira ntchito zida za kaboni pama brake pads zamagalimoto.
Mpweya wa carbon composite friction material ndi chinthu chapadera chokhala ndi kukhazikika kwa kutentha, kukana kuvala, kuyendetsa magetsi, mphamvu zenizeni, kusungunuka kwapadera ndi zina zambiri. Komabe, zida zokangana za carbon-carbon composite zilinso ndi zofooka zotsatirazi: friction coefficient ndi yosakhazikika. Zimakhudzidwa kwambiri ndi chinyezi;
Kulephera kwa okosijeni (kuchuluka kwa okosijeni kumachitika pamwamba pa 50 ° C mumlengalenga). Zofunika kwambiri zachilengedwe (zouma, zoyera); Ndi okwera mtengo kwambiri. Kugwiritsa ntchito kumangokhala kumadera apadera. Ichi ndi chifukwa chachikulu chomwe kuchepetsa zinthu za carbon carbon kumakhala kovuta kulimbikitsa kwambiri.
1.5, zidutswa za ceramic
Monga mankhwala atsopano mu zipangizo kukangana. Ceramic brake pads ali ndi ubwino wopanda phokoso, palibe phulusa lakugwa, palibe dzimbiri la gudumu, moyo wautali wautumiki, kuteteza chilengedwe ndi zina zotero. Ma ceramic brake pads adapangidwa koyambirira ndi makampani aku Japan brake pad mu 1990s. Pang'ono ndi pang'ono ndidzakhala wokondedwa watsopano pamsika wa brake pad.
Zomwe zimayimilira zida zolimbana ndi ceramic ndi C/C-sic composites, ndiye kuti, zophatikiza za carbon fiber zolimbitsa silicon carbide matrix C/SiC. Ofufuza ochokera ku yunivesite ya Stuttgart ndi German Aerospace Research Institute aphunzira kagwiritsidwe ntchito ka C/C-sic composites pankhani ya mikangano, ndipo apanga C/C-SIC brake pads kuti agwiritse ntchito pamagalimoto a Porsche. Oak Ridge National Laboratory yokhala ndi ma composites a Honeywell Advnanced, HoneywellAireratf Lnading Systems, ndi makina a Honeywell CommercialVehicle Kampaniyo ikugwira ntchito limodzi kuti ipange ma brake pads otsika mtengo a C/SiC kuti alowe m'malo mwa chitsulo choponyedwa ndi ma brake pads omwe amagwiritsidwa ntchito m'magalimoto olemera kwambiri.
2, carbon ceramic composite brake pad ubwino:
1, poyerekeza ndi miyambo imvi kuponyedwa chitsulo ananyema ziyangoyango, kulemera kwa carbon ceramic brake pads kuchepetsedwa pafupifupi 60%, ndipo osayimitsidwa misa yafupika pafupifupi 23 kilogalamu;
2, kugunda kwa ma brake coefficient kumawonjezeka kwambiri, kuthamanga kwa brake reaction kumachulukitsidwa ndipo kutsika kwa brake kumachepa;
3, kukwera kwamphamvu kwa zida za ceramic zoyambira 0.1% mpaka 0.3%, zomwe ndi zamtengo wapatali kwambiri pazinthu zadothi;
4, ceramic disc pedal imamva bwino kwambiri, imatha kutulutsa mphamvu yothamanga kwambiri poyambira, kotero palibenso chifukwa chowonjezera ma brake assist system, ndipo ma braking onse ndi achangu komanso amfupi kuposa ma braking system. ;
5, pofuna kupewa kutentha kwakukulu, pali kutentha kwa ceramic pakati pa pisitoni ya brake ndi liner ya brake;
6, ceramic brake disc imakhala yolimba modabwitsa, ngati kugwiritsidwa ntchito kwanthawi zonse kumakhala m'malo mwaulere, ndipo chimbale chachitsulo chachitsulo chachitsulo chimagwiritsidwa ntchito kwa zaka zingapo kusintha.
Nthawi yotumiza: Sep-08-2023