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Anglicky v odbornch pedmtech"Support of teaching technical subjects in EnglishTutorial: Engineering technology

Topic: Casting to temporary forms

Prepared by: Ing. Elena Nov

Projekt Anglicky v odbornch pedmtech, CZ.1.07/1.3.09/04.0002je spolufinancovn Evropskm socilnm fondem a sttnm rozpotem esk republiky.

Casting to temporary formsWith permanent patternWith lost pattern Hand formingMachine forming Vakuum forming Monocoque forming Precision casting Investment casting

1. Manual forming. This method is used for large castings. For castings, needed only in small quantities. In this picture we see the casting form produced by manually shaping under the crane to frame 1000x1000 mm.Forming with permanent model

Procedure:Model is made in accordance to drawingHalf of model is laid on modeling deskSuitable frame is superimposed and model is sand-rammed After ramming excessive sand is raked away by a ruler Frame is turned by 180 deg. and second half of model is superimposed Gating system, exhaust and second frame is rammed Frame is put together and weighted Cooled raw casting is removed Exhaust system and gating is removed Forming with permanent model

Models colored. is chosen according to cast iron type:

Red is for grey iron.

Models on plates for hand forming

2.Machine formingOn FOROMAT (shaking with pressing) to frames of max. dimension 600x650 mm small to medium series production

Forming with permanent model

Procedure for machine forming is the same as with hand forming except ramming and raw casting separation is done by machines.

Machined forms and resulting casts are more accurate with smoother surface. Forming with permanent model

3.Vacuum formingHere is forms cohesiveness kept under pressure .After cooling down of casting the sub-atmospheric pressure is zeroed and casting is removed. Casting sand can be used again. Forming with permanent model

4. Shell formingIn this type a shell forms (only few milimetres thick) are used made from silicon sand and resin. Casting have surface of very high quality (Ra 6,3) and exact dimensions.

Forming with permanent model

malosriov a sriov vrobaRun formovnStrojn formovnVakuov formovnSkoepinov formovn

Formovn s trvalm modelemModely na deskch pro run formovnSlovnekCvienVyjmenuj zpsoby formovn s trvalm modelem:1.2.3.4.Najdi na internetu pklady pouit,kter vrobky se danm zpsobem odlvaj.1.Kter zpsoby formovn pouvme pro maloseriovou vrobu :2.Kter zpsoby formovn pouvme pro velkoseriovou vrobu:Modern strojrenstv pro kolu i praxi.Josef Dillinger a kol.Europa-Sobotles cz., Praha 2007Used literature