Annular tool and moulding method for reducing sand usage amount by using the annular tool

Abstract

The invention provides an annular tool and a moulding method for reducing the sand usage amount. The annular tool comprises a plurality of single-layer annular tool parts that are exactly arranged up and down; each single-layer annular tool part comprises a plurality of separation boards and a plurality of connecting pieces; and the separation boards and the connecting pieces are sequentially arranged in a spaced manner. The moulding method comprises the steps of moulding a lower sand mould, turning over the lower sand mould, moulding a casting inner cavity sand mould, moulding an upper sand mould, parting, carrying out mould assembling, and the like; and in the step of moulding the casting inner cavity sand mould, a plurality of layers of the annular tools are placed in the center of an inner cavity of an annular casting hollow mould, the inner sides of the annular tools are filled with dry sand, and resin-bonded sand flows into space between the outer sides of the annular tools and the inner cavity of the annular casting hollow mould, thereby forming the casting inner cavity sand mould. During moulding, the annular tools divide the inner cavity into two parts into which the resin-bonded sand and the dry sand flow separately, in this way, the use amount of the resin-bonded sand is reduced substantially, the cost is lowered, and no moulding of a casting cavity is affected.

Description

technical field [0001] The invention relates to the technical field of sand casting, in particular to an annular tool and a molding method for reducing the amount of sand used by using the annular tool. Background technique [0002] In the field of traditional casting sand casting, resin sand + wooden molds are generally used to mold in the sand box. The shape of the sand box is a right-angled quadrilateral, and the size is determined according to the specifications of the casting. [0003] In order to control the cost and reduce the amount of sand used, some companies also isolate the corners of the quadrilateral sand box without filling it with molding sand. This also plays a certain role and is less difficult to implement. [0004] However, for hydropower ring castings 80, the main body contour of the ring castings is 4600mm×1100mm, and the three-dimensional contours are as follows figure 1 As shown, these castings have the characteristics of large outline and small wall...

AI Technical Summary

Problems solved by technology

[0004] However, for hydropower ring castings 80, the main body contour of the ring castings is 4600mm×1100mm, and the three-dimensional contours are as follows figure 1 As shown, these castings have the characteristics of large outline and small wall thickness. In order to adapt to the large outline of the casting, the traditional sand casting of this type of casting adopts the internal and external integral quicksand molding to obtain the semi-finished cavity of the casting before pouring, such as figure 2 As shown, compared with the weight of the space occupied by the casting mold 70, the use weight of the resin sand inside the casting plus the resin sand outside the casting is more than 13 times the weight of the casting, and the used sand of each casting belongs to a disposable semi-finished product, which cannot Recycled use, the cost of resin sand accounts for 20% of the entire casting production cost, resulting in a decrease in casting profits. At the same time, due to the excessive thickness of resin sand, it is difficult to discharge the gas after the internal resin is burned during pouring, and it is easy to cause appearance defects such as pores and slag inclusions in castings

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