A dark riser casting sand core

Abstract

The invention belongs to the technical field of casting, and specifically relates to a casting sand core with a dark riser; it includes a sand core body and a dark riser body arranged in the sand core; the upper end of the dark riser body is provided with a stepped hole, and The diameter of the upper hole of the stepped hole is greater than the diameter of the lower hole; the upper end of the sand core body is provided with a chute through hole, and the diameter of the chute through hole is equal to the diameter of the upper hole of the stepped hole; Air guide column; the chute through hole on the sand core body can prevent the residual material deposited in the chute through hole from falling into the dark riser body through the through hole on the dark riser body again due to the action of gravity , which in turn affects the high-quality pouring effect of the riser body; the set chute through hole can reduce the falling speed of sand particles, and at the same time, part of the falling sand particles will fall into the bottom end surface of the upper end hole of the stepped hole, thereby reducing the sand particles falling into the dark In the riser body, thereby reducing defects such as sand inclusions and inclusions in the casting.

Description

technical field [0001] The invention belongs to the technical field of casting, in particular to a casting sand core with a hidden riser. Background technique [0002] In the casting process, after the molten metal is poured into the mold, due to cooling and solidification, it changes from liquid to solid, resulting in volume shrinkage. When volume shrinkage cannot be replenished by molten metal, shrinkage cavities and shrinkage porosity will occur in the parts with larger modulus in the casting after solidification. For those casting alloys with large volume shrinkage, this defect often occurs. Shrinkage cavity and shrinkage porosity will reduce the compactness of castings, reduce the effective cross-sectional area of ​​castings, and greatly reduce the mechanical properties. Therefore, it is necessary to control solidification and prevent defects. [0003] The use of risers is currently the most effective and popular process measure to control solidification and compensat...

AI Technical Summary

Problems solved by technology

[0004] And existing dark riser when pouring high-temperature molten metal, the high gas that the molten metal of high temperature produces can eject a large amount of flames in the through hole of dark riser, have very high temperature, the through hole periphery of sand core The molding sand is baked loose, causing the sand grains on the sand core body to fall off seriously, and the sand grains of the sand core will enter the hidden riser, resulting in defects such as sand inclusions and inclusions in the casting

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