Txoj hauj lwm pouring ntawm ib tug casting yog hais txog lub xeev thiab orientation ntawm lub casting nyob rau hauv lub pwm thaum lub sij hawm pouring. Nws cuam tshuam ncaj qha rau cov qauv ntawm cov cuab yeej (xws li cov qauv thiab cov thawv tseem ceeb) thiab cov txheej txheem rau kev ua haujlwm xws li kev teeb tsa tseem ceeb, pwm kaw, thiab ntxuav, thiab tseem tuaj yeem cuam tshuam rau kev ua haujlwm tom ntej. Txoj hauj lwm pouring tuaj yeem txawv ntawm qhov molding (kaw) txoj hauj lwm thiab qhov chaw txias ntawm qhov casting. Kab rov tav pouring, ntsug pouring, thiab inclined pouring tsis sawv cev rau txoj hauj lwm pouring nws tus kheej, tab sis tsuas yog qhia lub spatial orientation ntawm txoj kab parting thaum lub sij hawm pouring.
Txoj hauj lwm pouring feem ntau txiav txim siab tom qab xaiv txoj kev molding. Nws yuav tsum raug xam tias yog ua ke nrog cov casting qhov loj me, cov yam ntxwv ntawm cov qauv, cov khoom alloy, ntau lawm batch, thiab cov lag luam cov khoom siv. Cov txheej txheem npaj yuav tsum tau txheeb xyuas thiab muab piv rau xaiv qhov tsim nyog pouring txoj hauj lwm. Ib txoj hauj lwm pouring kom raug yuav tsum xyuas kom meej cov suab nrov castings thaum uas yooj yim molding, core ua, thiab ntxuav cov hauj lwm. Cov ntsiab cai dav dav rau kev txiav txim siab txoj hauj lwm pouring yog raws li nram no:
(1) Cov ntu tseem ceeb yuav tsum muab tso rau hauv qab.
Thaum lub sij hawm pouring, impurities xws li gases, slag, thiab xuab zeb particles zoo li ntab upwards. Yog li ntawd, lub sab sauv ntawm ib tug casting yog feem ntau mus rau defects xws li roj porosity, slag inclusions, thiab xuab zeb inclusions, lub ntsiab lus yuav ua tau ntawm casting defects yog ho siab dua nyob rau hauv lub Upper sab dua nyob rau hauv qis. Tsis tas li ntawd, thaum lub sij hawm solidification, qhov qis ntawm cov kev pab cuam casting los ntawm qhov zoo li qub siab ntawm cov hlau molten saum toj no thiab tau txais kev pub mis, ua rau cov qauv denser. Yog li ntawd, cov seem tseem ceeb ntawm lub casting yuav tsum muab tso rau hauv qab thaum twg los tau. For instance, the guide rail surface of a machine tool bed is a critical surface that must be free from defects like sand holes, gas porosity, slag inclusions, cracks, and shrinkage porosity, and requires a dense, uniform structure with guaranteed hardness. Txawm hais tias cov lus qhia kev tsheb ciav hlau yog qhov tuab thiab loj, rau lub txaj grey cam khwb cia hlau tshuab cuab yeej txaj, muab cov lus qhia kev tsheb ciav hlau ntog rau hauv qab yog qhov zoo tshaj plaws pouring txoj hauj lwm.
(2) Cov chaw machining tseem ceeb yuav tsum tig mus rau pem hauv ntej lossis muab tso rau ntawm sab.
Raws li sab sauv ntawm ib qho casting yog qhov ua rau tsis xws luag xws li roj porosity, slag inclusions, thiab xuab zeb inclusions, hauv qab saum npoo los yog ntsug sab saum npoo muaj qhov qis dua ntawm qhov tsis xws luag. Yog li ntawd, qhov chaw tseem ceeb ntawm lub casting yuav tsum tig mus rau hauv qab los yog muab tso rau ntawm sab. Thaum lub machining nto yuav tsum tau muab tso rau pem hauv ntej, qhov nyiaj pub rau machining yuav tsum tau nce kom tsim nyog kom tsis muaj qhov tsis xws luag nyob tom qab machining.
Rau cylindrical castings zoo li crane drums thiab yob, qhov tseem ceeb ntawm qhov chaw yog sab nrauv cylindrical nto, uas yuav tsum muaj cov qauv zoo sib xws thiab kev ywj pheej los ntawm qhov tsis xws luag tom qab machining. Qhov zoo tshaj plaws pouring txoj hauj lwm rau cov no yog kom muaj lub sab nrauv cylindrical nto nyob rau hauv ib tug ntsug orientation. For gears, the tooth surface is the primary working surface and should face downward to ensure a dense structure and prevent casting defects.
(3) Cov npoo loj loj yuav tsum tig mus rau hauv qab los yog inclined.
Thaum pouring ib tug casting nrog ib tug loj tiaj tus nto, lub molten hlau nce maj mam nyob rau hauv lub pwm kab noj hniav. Qhov kev cuam tshuam ntev ntawm cov cua sov tuaj yeem ua rau cov xuab zeb poob los ntawm cov pwm, ua rau muaj qhov tsis xws luag xws li cov xuab zeb inclusions, xuab zeb qhov, thiab roj porosity ntawm lub tiaj tus. Yog li ntawd, qhov loj tiaj tus ntawm castings yuav tsum ua tib zoo fim downward. Rau cov phaj loj -zoo li castings, inclined pouring tuaj yeem txais yuav. Qhov no yuav pab mloog zoo rau cov hlau molten thaum lub sij hawm txhaws, ua rau kom nce ceev ntawm cov hlau molten, thiab pab tiv thaiv tsis xws luag xws li xuab zeb scabs thiab inclusions. Thaum lub sij hawm inclined pouring, tus nqi H (qhov siab qhov sib txawv) feem ntau tswj nyob rau hauv qhov ntau ntawm 200-400mm, nyob ntawm seb lub hwj loj.
(4) Ua kom muaj peev xwm ua kom muaj pwm txaus rau lub casting.
Nyias-cov phab ntsa ntawm cov casting muaj kev tiv thaiv ntau dua rau kev ntws, txias sai dua, thiab muaj peev xwm sau tsis zoo. Cov ntu nyias no yuav tsum tau muab tso rau hauv qis qis ntawm cov pwm, ntawm sab, lossis hauv qab ntawm qhov nkag los tiv thaiv qhov tsis xws luag xws li misruns thiab txias kaw, xws li hauv lub cav kawg npog thiab crankcases.
(5) Txaus siab rau lub hom phiaj solidification sequence.
Lub pouring txoj hauj lwm yuav tsum conducive mus rau qhov xav tau solidification sequence. Rau cov castings ua los ntawm cov alloys nrog siab solidification shrinkage los yog nrog cov phab ntsa tsis sib xws uas ua rau shrinkage kab noj hniav thiab porosity, qhov kev xaiv ntawm pouring txoj hauj lwm yuav tsum tau ua ntej kom ua tiav cov kev taw qhia solidification. Cov ntu tuab ntawm cov casting yuav tsum zoo dua nyob rau saum toj lossis ntawm sab kom yooj yim rau kev tso cov risers rau kev pub mis. Piv txwv li, cov tuab tuab ntawm lub taub hau lub tog raj kheej tau muab tso rau saum toj kom tso cai rau kev tso qhov nce, ua kom muaj kev taw qhia kev ruaj khov los ntawm hauv qab mus rau sab saud.
(6) Txhim kho qhov chaw tseem ceeb, kev txhawb nqa ruaj khov, thiab yooj yim ntawm kev teeb tsa, pwm kaw, thiab tshuaj xyuas.
Txoj hauj lwm pouring yuav tsum pab txhawb qhov chaw thiab ruaj khov ntawm cov xuab zeb cores, kom ntseeg tau tias qhov cua zoo. Dai cores (cores txhawb nqa los ntawm kev tiv thaiv), dai cov tub ntxhais sib dhos, lossis cov cores cantilevered yuav tsum zam kom ntau li ntau tau. Cov cores dai tuaj yeem ua rau cov xuab zeb sib tsoo los yog ua tsis tau thaum pwm kaw thiab nchuav. Muab dai cov tub ntxhais sib dhos rau hauv qhov chaw ua haujlwm tsis yooj yim. Cantilevered cores tsis ruaj khov thiab muaj kev cuam tshuam vim muaj zog ntawm cov hlau molten thaum sau, ua rau cov duab tsis raug. Yog li ntawd, lawv yuav tsum zam. Tsis tas li ntawd, qhov kev xaiv ntawm txoj haujlwm pouring yuav tsum xav txog qhov yooj yim ntawm kev teeb tsa, pwm kaw, thiab tshuaj xyuas.
(7) Siv zog ua kom cov pwm kaw txoj hauj lwm, txoj hauj lwm pouring, thiab casting txias txoj hauj lwm zoo ib yam.
Inverting pwm tsis yog tsuas yog ua hauj lwm - hnyav tab sis kuj tuaj yeem yooj yim ua rau lub hauv paus hloov, xuab zeb poob, khiav - tawm, thiab lwm yam tsis xws luag. Yog li ntawd, thaum lub sij hawm tus txheej txheem tsim, lub pwm kaw txoj hauj lwm, pouring txoj hauj lwm, thiab casting txias txoj hauj lwm yuav tsum zoo ib yam kom tsis txhob inverting pwm tom qab kaw los yog pouring. Qee zaum, rau qhov yooj yim ntawm molding, ib txoj kev zoo li "pwm kab rov tav, ncuav vertically" yog saws. Piv txwv li, thaum tsim cov nodular hlau crankshafts, cov pwm yuav muab tso rau vertically tom qab pouring thiaj li hais tias tus riser nyob rau sab saum toj los pab noj. Los yog "pwm horizontally, ncuav inclinedly," xws li inclined pouring rau phaj castings. Thaum txoj hauj lwm pouring tsis sib haum nrog lub kaw txoj hauj lwm (los yog txias txoj hauj lwm), qhov no yuav tsum tau qhia kom meej nyob rau hauv lub casting txheej txheem daim duab.
Cov saum toj no yog cov ntsiab cai dav dav rau kev txiav txim siab txoj hauj lwm pouring. Feem ntau, tag nrho cov hauv paus ntsiab lus no tsis tuaj yeem txaus siab ib txhij lossis embodied nyob rau hauv ib qho casting. Qee lub sij hawm, cov ntsiab cai no tej zaum yuav tsis sib haum xeeb rau ib leeg hauv kev siv rau tib qho kev casting. Qhov no yuav tsum tau tus txheej txheem tsim kom yooj yim txiav txim siab lub pouring txoj hauj lwm raws li lub casting tus yam ntxwv yam ntxwv, zoo yuav tsum tau, thiab ntau lawm tej yam kev mob, nyob rau hauv thiaj li yuav pab txhawb kev ua hauj lwm ntau lawm, zam los yog txo qhov tsis xws luag casting, thiab xyuas kom meej casting zoo.
