A hybrid core molding process

Abstract

The invention discloses a mixed child-mother core assembly molding technology. A 3D printing molding technology and a sand mixing molding technology are combined, a part which is close to a product part having a plurality of structural features adopts 3D printing, and the other parts which have less structural features adopt the traditional sand mixing molding technology method, therefore an assembled sand mold which works through cooperative using of a mother core and a child core is formed. Based on the advantages of an original 3D printing molding technology, a traditional sand mixer production technology is introduced, the two molding technologies are combined with each other, further the cost of raw materials and the equipment investment cost are lowered, and meanwhile, child-mother separated core combination is conducted on a sand molding part which is brought out of a casting and the mold thickness which is brought out of a casting system and improves the strength so as to widen thinking for later multi-technology combination; the number of castings in a single sand box is increased, the sand box utilization ratio and the production efficiency are improved, the dependence on manual work is reduced at the same time, the cost of 3D printing raw materials and the depreciation of the equipment are reduced, and meanwhile, waste of molten iron is avoided, and the purposes of cost reduction and efficiency improvement are achieved.

Description

technical field [0001] The invention relates to the field of casting technology, in particular to a molding process of mixed mother-child assembly cores. Background technique [0002] Take the Tu-40 pump body, an important part of a railway locomotive, as an example. Its material is HT200, its outline size is 163mm×149mm×113mm, and its mass is 5.3Kg. It is a small gray iron product. Because it is a small product, the casting cavity is small, and the diameter of the inner cavity of the oil pipe needs to be cast is only 15mm, and the sand core requirements are relatively high. In the past, tung oil sand was often used as the inner cavity core and core bone was added, and resin sand was used as the outer shape. A variety of sand mixing processes are used; because the inner cavity core needs to be lowered separately, the traditional process often adopts the method of flat casting and flat pouring, and the number of castings in the sand box is small, and it can only be completed ...

AI Technical Summary

Problems solved by technology

However, using 3D printing modeling technology to directly print the whole block not only needs to print out the sand mold that brings out the casting, but also needs to print out an additional amount of sand to ensure the strength of the sand mold. Because the raw materials such as 3D printing sand, resin, and curing agent are more expensive than The price of raw materials for traditional sand mixer modeling is much higher, so it is difficult to reduce the production cost; at the same time, the sand core is printed in one block, because the diameter of the sand core in the inner cavity of the casting is small, and the 3D printing model cannot add core bone to enhance the strength of the sand core, so in In the sand core assembly and transfer process, it is inevitable to damage the inner cavity of individual castings in the sand core of the serial casting module, which cannot be replaced or repaired, and can only be poured continuously, resulting in waste of molten iron, which in turn increases the scrap rate and further increases the cost. , the advantages of 3D printing string pouring have also been weakened

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