Vacuum casting sand box

Abstract

The invention relates to a vacuum casting sand box. The vacuum casting sand box comprises a sand box bottom and a sand box wall, wherein a bottom air channel is uniformly arranged at the lower part of the sand box bottom and is communicated with a bottom air suction pipe arranged at the outer side of the sand box, the sand box wall comprises an inner wall and an outer wall, and side air channels are uniformly arranged between the inner wall and the outer wall, and are communicated with a side air suction pipe arranged at the outer side of the sand box, and air suction holes communicated with the bottom air channel and the side air channels are arranged on the inner walls of the sand box bottom and the sand box wall, and a sand prevention mesh is arranged on the air suction holes; and an air inlet steel pipe is inserted into a square sand layer in the sand box corresponding to a part of a vacuum lost foam. Air enters the steel pipe without the help of another device, and therefore the cost is greatly reduced, the adaptability is high, the solidification of casting hot spots is accelerated, the riser feeding amount is reduced, and the utilization rate of molten iron is improved; and the vacuum casting box has remarkable advantages and effect.

Description

technical field [0001] The invention relates to a dry sand casting sand box for vacuum lost foam casting. Background technique [0002] Many equipment components must use castings, and the practical range of castings is very wide. [0003] Generally, castings are formed by sand box casting. Ordinary sand boxes are open. After the molten metal is poured, it is self-cooling and formed. In this way, the internal density of the cast parts is not uniform enough, and defects such as pores and looseness are prone to occur, and the pressure resistance of the castings is poor. , the overall quality is not high enough. [0004] At present, vacuum lost foam casting technology is widely used. However, in the process of vacuum lost foam casting, the filling of dry sand is the key to vacuum lost foam casting. When dry sand is filled with vibration, if the vibration strength is not enough or the filling is not solid , when casting, it is easy to cause the collapse of the box, and the cas...

AI Technical Summary

Problems solved by technology

[0003] Generally, castings are formed by sand box casting. Ordinary sand boxes are open. After the molten metal is poured, it is self-cooling and formed. In this way, the internal density of the cast parts is not uniform enough, and defects such as pores and looseness are prone to occur, and the pressure resistance of the castings is poor. , the overall quality is not high enough

[0004] At present, vacuum lost foam casting technology is widely used. However, in the process of vacuum lost foam casting, the filling of dry sand is the key to vacuum lost foam casting. When dry sand is filled with vibration, if the vibration strength is not enough or the filling is not solid , when casting, it is easy to cause the box to collapse, and the cast parts will become waste products

In view of this situation, the sand box adopted in the vacuum lost foam casting molding method of large and complex castings disclosed by the Chinese patent No. 200910074893.3 basically solves the above-mentioned problems, but this sand box is a box of a cube or a cuboid , for some special-shaped castings, especially the special-shaped castings with lateral horizontal holes on the side of the casting, the dry sand in the side holes is difficult to fill, and the case of box collapse often occurs. Defective products, increased costs

[0005] In addition, at present, most of the casting sand boxes used by general foundry manufacturers in sand casting are welded components or castings. In the production of iron castings, especially ductile iron castings, the sand box is often insufficient in rigidity. Escape, so that the graphitization expansion of cast iron cannot be effectively utilized, resulting in defects such as shrinkage and porosity of castings, and in severe cases, castings will be scrapped

Due to the limitation of existing casting tooling and the limit of manufacturing cost, the above situation often occurs in the actual production process

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