Forming a box-bound sand mold half e.g. an upper box, comprises introducing a model of a first size into a molding box, filling loose, compacted molding sand as greensand into the molding box and then condensing, and removing the model

摘要

The method of forming a box-bound sand mold half, comprises introducing a model of a first size into a molding box, filling loose, compacted molding sand as greensand into the molding box and then condensing, removing the model, introducing a core piece (30, 30') in a first cavity resulting by the removal of the model, where the core piece has a second size that is smaller than the first size and a filling space outside of the core piece, and filling loose sand without binding agents into the filling space by a funnel (36) for the formation of an intermediate layer (40a, 40b). The method of forming a box-bound sand mold half, comprises introducing a model of a first size into a molding box, filling loose, compacted molding sand as greensand into the molding box and then condensing, removing the model, introducing a core piece (30, 30') in a first cavity resulting by the removal of the model, where the core piece has a second size that is smaller than the first size and a filling space outside of the core piece, filling loose sand without binding agents into the filling space by a funnel (36) for the formation of an intermediate layer (40a, 40b) between the core piece and an inside wall of the compacted molding sand, and forming first projections or recesses at a surface of the compacted molding sand for holding the core piece inserted into the cavity. The box-bound sand mold half has the compacted molding sand as greensand, and comprises a recess into which a portion of the core piece protrudes for receiving a metal casting. The core piece comprises complementary recesses or projections, which cooperate with the first projections or recesses. The funnel is formed in an other box half filled with the compacted molding sand. The other box half has a second cavity, which receives another portion of the core piece, and the funnel ends in the second cavity outside of the core piece. An insulating layer is placed around the core piece during filling the loose sand by the funnel. A filler material suitable for isolation is provided in the filling space. The filling space is formed as a thermal insulating layer between the core piece and the compacted molding sand, and is greater than 10% of the cavity. The filler is compacted in the filling space by vibrating or shaking. An independent claim is included for a box-bound sand mold.