摘要:
The invention relates to a method for the uphill casting of cast pieces in sand dies with resinous, or, in particular, binder-containing cast cores and controlled solidification of metallic cast pieces, comprising at least one cavity. Said pieces are, in particular, prototypes of engine blocks, or cylinder heads, for example, for internal combustion engines, with a cavity for the throughflow of cooling water. In order to guarantee a low-turbulence flow of fluid metal melt on ventilating the cast mould, the cast mould (1), with at least one feed (24), is connected to a sprue cup (24) by means of a casting system (22) and the metal melt contained therein forced into the cast mould (1) through the casting system (22) by gravity. After filling the cavity (11") a vacuum is created in the metal melt, greater than the pressure of core gases generated in the core. Air cushions in the mould are, thus, prevented from impeding the filling of the mould and, by means of the above method, impervious, pore-free, mechanically sound cast pieces are produced.
摘要:
The invention relates to a method for producing heat-resistant casting moulds from mould materials, especially from moulding sand containing a binding agent, or for producing an inner contour of models or prototypes consisting of plastic, graphite, derived timber products or other millable materials. Large volumes and deep gravures are often obtained, especially during the machining of moulds for the rapid production of prototypes of cast materials. In order to increase the efficiency of the inventive method, in a first step, blocks of mould material are produced in such a way that a dimension thereof corresponds to a mould cavity depth which typically measures up to between 300 and 400 mm. The inner contour of the mould is then produced in such a way that it has an oversize having a contour which is close to the contour of the inner wall of the mould cavity, using a roughing tool (4) having an effective cutting diameter of between 12 and 35 mm. The mould cavity is then machined by milling the oversize material, following the contour, using a finishing cutter (3) having a diameter-length ratio of between 1:10 and 1:30.