Casting mold and casting method of high aluminum zinc alloy annular casting parts

Abstract

The invention discloses a casting mold of high aluminum zinc alloy annular casting parts. A metal outer mold of the casting mold is positioned on a metal bottom plate, a metal core mold is positioned in the center of the metal bottom plate, a casting mold cavity with an annularly opened upper opening is formed by a cavity among the upper side of the metal bottom plate, the inner edge of the metal outer mold and the outer edge of the metal core mold, a casting mold sand core is fixed on the upper side of the metal core mold, a metal cover plate is covered on the upper side of the metal outer mold, and knurling is arranged on the bottom surface of the casting mold cavity. The invention also discloses a casting method for the high aluminum zinc alloy annular casting parts. The method includes 1) injecting liquid-state high aluminum zinc alloys into the casting mold cavity until the high temperature liquid level rises to the upper side of the metal outer mold; 2) lifting the metal cover plate to the upper side of the metal outer mold, continuing casting, compensating cooled the upper lateral surfaces of casting parts until the casting parts are formed finally. The casting mold and casting method reduces dendrite segregation and pinholes among dendrites, improves mechanical property of the casting parts and greatly increases qualified rate of the casting parts.

Description

technical field [0001] The invention relates to a casting mold for non-ferrous metal castings, and also relates to a gravity casting method for manufacturing high-aluminum-zinc alloy annular castings by using the mold, belonging to the technical field of non-ferrous metal casting. Background technique [0002] Worm gear reducers are widely used in high-power mechanical transmission devices due to their advantages of large transmission power and transmission ratio, compact structure, small size, low noise, and self-locking. Most elevator traction machines in high-rise buildings use worm gear reducers. The material of the worm gear is generally made of wear-resistant cast copper alloy or cast zinc-based alloy. In order to reduce the manufacturing cost of the worm gear, the structural type of the worm gear mainly adopts non-ferrous metal rim and cast iron wheel core. combination. Cast high-aluminum-zinc alloys have high wear resistance and low friction coefficient, and are oft...

AI Technical Summary

Problems solved by technology

Conventional metal casting molds and casting methods have the following defects: Under normal solidification conditions, high-aluminum-zinc alloy castings are prone to shrinkage cavities on the bottom surface. The reason why the casting solidification sequence is reversed

In addition, due to the large temperature difference between the liquid-solidus line of the high-aluminum-zinc alloy, the dendrites grow well during the solidification process, and the final solidification between the dendrites cannot be fully fed, and micro-dendritic segregation and intergranular pinholes are easily produced. Shrinkage cavity

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