Upper neck casting mold of integrated cast steel supporting roll

Abstract

The invention relates to improvement on an integrated casting mold of a cast steel supporting roller and is characterized in that: a roller neck metal mold has an integrated structure, an inside sand mold extends downwards to the upper part of a roller body casting mold, and a gravity pressure block is arranged above a roller neck mold. The structure overcomes the shortcomings of the conventionalhindrance technology, makes an upper neck casting blank in a pressure stress state and can guarantee that the casting sand mold can still be dispersed effectively during sintering, so that the axial shrinkage of a casting blank during the cooling shrinkage after the casting is ensured, the resistance to castings during condensation shrinkage is reduced and the risk of generating thermal cracks and pull cracks of the castings is eliminated; meanwhile, the integrated casting mold has low requirements on precision, is simply manufactured, has a few joints and reduces steel leakage risks. The roller neck casting mold completely solves the two major shortcomings of the integrated casting of the supporting roller.

Description

technical field [0001] The present invention is an improvement to the integral casting mold of the cast steel support roll, and particularly relates to an upper neck which can effectively reduce the blockage of the casting during solidification and shrinkage, prevent the mechanical suspension of the casting, and reduce the risk of steel breakout when the cast steel support roll is cast integrally. mold. Background technique [0002] When the casting workpiece is cooled and solidified, it will inevitably shrink. If the natural shrinkage is not guaranteed, it will cause cracks or fracture damage to the casting due to shrinkage. serious. Integral cast steel backup roll casting, the roll body and roll neck are formed by simultaneous casting (such as the casting method of Chinese patent CN1597180), and the casting mold is formed by vertically combining split metal molds. Due to the large amount of molten steel poured by the huge backup roller, the high temperature of the molte...

AI Technical Summary

Problems solved by technology

This method leaves space for shrinkage by pulling out the slider, which can theoretically meet the shrinkage requirements. However, due to the fact that the upper roll neck molding sand is sintered into blocks under high-temperature baking during casting, the actual strength is relatively high, and it is not easy to collapse; secondly, because the upper neck mold passes through The metal mold tongue ring is inserted into the casting mold of the roll body, and the slider section is inserted into the metal mold, and the metal mold itself is not easily deformed. Although the slider is withdrawn, the metal mold is pressed against the end face of the upper roll body, hindering the movement of the upper roll neck. shrinkage, and because the metal tongue ring makes the upper neck mold into a whole, the tongue ring is pressed against the end of the roller body to bear the force of the metal tongue ring, which increases the difficulty of destroying the sintered sand mold under the action of gravity, so it is actually difficult to ensure 100% It can shrink freely, and it will also be blocked by shrinkage; moreover, the mold sand A at the lower end of the tongue ring of the metal mold is easy to fall off during casting. Once the tongue ring falls off, it will directly contact the molten steel, causing cold shut or cracks in the casting

The above factors still cannot completely eliminate the casting defects that the shrinkage of the upper neck slab is hindered, and the casting causes cold shuts or cracks

In addition, the assembly of the combined roll neck metal mold is cumbersome and requires high dimensional accuracy. The number of assembled parts and joints also increase the probability of steel breakout

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