Mitundu ya zida za extrusion ndi extrusion

Extrusion ndi njira yopondereza yomwe chipika chachitsulo chimafinyidwa kudzera pamphuno kapena kufa potsegula kuti athe kuchepetsa m'mimba mwake ndikuwonjezera kutalika kwa chipika chachitsulo.Chotsatiracho chidzakhala ndi gawo lomwe mukufuna.Extrusion imaphatikizapo kupanga zigawo za axisymmetric.Kufa kwa zozungulira pazigawo zopanda zozungulira zimagwiritsidwa ntchito potulutsa.Nthawi zambiri, extrusion imaphatikizapo kupanga mphamvu zazikulu.Kupsyinjika kwakukulu kwa hydrostatic mu extrusion kumathandizira pakupititsa patsogolo ductility ya zinthuzo.Zitsulo monga aluminiyamu, zomwe zimagwira ntchito mosavuta, zimatha kutulutsa kutentha kwachipinda.

Mitundu ya extrusion:

Direct extrusion:Direct extrusion, yomwe imatchedwanso kutsogolo extrusion, ndi njira yomwe billet imayenda motsatira njira yomwe nkhosa ndi nkhonya zimachitira.Kutsetsereka kwa billet kumatsutsana ndi khoma la chidebe chokhazikika. Mkangano pakati pa chidebe ndi billet ndiwokwera.Chifukwa chake, mphamvu zazikulu zimafunikira.Dummy block ya m'mimba mwake yotsika pang'ono kuposa m'mimba mwake ya billet imagwiritsidwa ntchito pofuna kupewa oxidation ya billet pakuwotcha.Magawo opanda kanthu ngati machubu amatha kutulutsidwa ndi njira yachindunji, pogwiritsa ntchito hollow billet ndi mandrel omwe amamangiriridwa ku chipika cha dummy.

Indirect extrusion:Indirect extrusion (backward extrusion) ndi njira yomwe nkhonya imasuntha mosiyana ndi billet.Pano palibe kuyenda kwachibale pakati pa chidebe ndi billet.Chifukwa chake, pali mikangano yocheperako, chifukwa chake mphamvu zochepera zimafunikira pakutulutsa kosalunjika.Powonjezera zidutswa zolimba, nkhonya yopanda kanthu imafunika.Mu dzenje extrusion, zinthu amakakamizika kudutsa annular danga pakati pa nkhonya olimba ndi chidebe.Kusiyanasiyana kwa kuthamanga kwa extrusion mu extrusion yosalunjika kukuwonetsedwa pamwambapa.Monga tawonera, kuthamanga kwa extrusion kwa indirect extrusion ndi yotsika kuposa kutulutsa mwachindunji.Zigawo zambiri zimapangidwa ndi kuphatikiza ma extrusions achindunji komanso osalunjika.Extrusion yosalunjika sangathe kugwiritsidwa ntchito extruding yaitali extrudes.

Hydrostatic extrusion:Mu hydrostatic extrusion chidebecho chimadzazidwa ndi madzimadzi.Kuthamanga kwa extrusion kumafalikira kudzera mumadzimadzi kupita ku billet.Kukangana kumathetsedwa munjira iyi chifukwa palibe kulumikizana pakati pa billet ndi khoma la chidebe.Zida za Brittle zimatha kutulutsidwa ndi njirayi.Zida zowonongeka kwambiri zimatha kutulutsidwa m'chipinda choponderezedwa.Kuchepetsa kwakukulu kumatheka ndi njira iyi.Kupanikizika komwe kumakhudzidwa ndi ntchitoyi kungakhale kokwera mpaka 1700 MPa.Kupanikizika kumachepa ndi mphamvu ya chidebe, nkhonya ndi zida zakufa.Mafuta a masamba monga mafuta a castor amagwiritsidwa ntchito.Kawirikawiri ndondomekoyi ikuchitika kutentha.Zoyipa zingapo za njirayi ndi: kutayikira kwamafuta oponderezedwa komanso kuthamanga kosalamulirika kwa extrusion pakutuluka, chifukwa chotulutsa mphamvu yosungidwa ndi mafuta.Izi zitha kuchititsa mantha mu makina.Vutoli limagonjetsedwa ndikupangitsa nkhonyayo kuti igwirizane ndi billet ndikuchepetsa kuchuluka kwa mafuta kudzera mu chilolezo chochepa pakati pa billet ndi chidebe.

Impact extrusion:Zigawo zopanda kanthu monga makapu, zotsukira mano zimapangidwa ndi kutulutsa mphamvu.Ndiko kusinthika kwa indirect extrusion.nkhonya imapangidwa kuti igunde slug pa liwiro lalikulu ndi mphamvu yamphamvu.Machubu a khoma laling'ono akhoza kupangidwa.Nthawi zambiri zitsulo monga mkuwa, aluminiyamu, lead zimatuluka.

Tube extrusion:Kugwiritsa ntchito billet hollow ndi mandrel kumapeto kwa nkhosa yamphongo, magawo opanda kanthu monga machubu amatha kutulutsidwa kuti azitha kupirira kwambiri.Mandrel amapitilira mpaka khomo la kufa.Chilolezo pakati pa mandrel ndi kufa khoma amasankha khoma makulidwe a chubu.Mandrel amapangidwa kuti aziyenda limodzi ndi nkhosa yamphongo kuti apange machubu okhazikika ndi extrusion.

Kuzizira ndi kutentha extrusion:

Cold extrusion imatha kutulutsa mbali zokhala ndi mapeto abwino, mphamvu zambiri chifukwa cha kuuma kwa zovuta, kuwongolera bwino, kupanga kwakukulu.Komabe, njirayi imafuna kupanikizika kwakukulu ndipo zida zimakhudzidwa ndi zovuta zambiri.Kupaka mafuta koyenera ndikofunikira popewa kugwidwa kwa chida ndi workpiece.Zovala zokutira za phosphate zimathiridwa ndi sopo.

Hot extrusion angagwiritsidwe ntchito kwa apamwamba extrusion ratios.Inhomogeneous mapindikidwe akhoza kuchitika chifukwa kufa khoma kuzizira kwa billet.Chitsulo chikhoza kukhala oxidized.Kusanjikiza kwa oxide kumatha kukulitsa kukangana komanso kuyenda kwazinthu.Galasi imagwiritsidwa ntchito ngati mafuta opangira kutentha.Molybdenum disulfide kapena graphite ndi mafuta olimba omwe amagwiritsidwa ntchito potulutsa kutentha.Zazitini extrusion ntchito woonda mipanda zitini zopangidwa ndi mkuwa kapena malata nthawi zambiri ntchito extruding kwambiri zotakasika zitsulo ndi ufa zitsulo.

Makina osindikizira a Extrusion:

Makina osindikizira a Hydraulic amtundu woyima kapena wopingasa amagwiritsidwa ntchito potulutsa.Makina osindikizira oyima ndi amphamvu kuyambira 3 mpaka 20 MN.Makina osindikizira opingasa amakhala ndi malo ochepa, koma ma billet amazizira mosiyanasiyana.Makina osindikizira opingasa mpaka 50 MN akugwiritsidwa ntchito.Ma tubular extrusion nthawi zambiri amapangidwa mu makina oyimirira, pomwe makina osindikizira opingasa amagwiritsidwa ntchito potulutsa bar.