A method and system for making gypsum cores used in large-scale impeller casting

Abstract

The invention discloses a manufacturing method and apparatus for a gypsum core used for casting of a large impeller. The manufacturing method comprises the following steps: 1, inlaying cast mold low-melting-point alloy impeller blades in a gypsum core mold; 2, carrying out mixing to prepare gypsum slurry and adding the mixed gypsum slurry into a vacuum mixer; 3, carrying out vacuum-pumping and vibratory mixing on the gypsum slurry by using the vacuum mixer; 4, injecting the gypsum slurry having undergone bubble removal into the gypsum core under vacuum conditions and carrying out vibration and defoaming by using a vibration machine after completion of injection; 5, strickling the upper end of the gypsum core by using a tool after completion of injection; 6, placing the cured gypsum core on a special gypsum core drying bracket; 7, putting the bracket and the gypsum core into a drying machine; 8, taking the gypsum core and the bracket, separating the gypsum core from the bracket, collecting low-melting-point alloy for reuse, placing the gypsum core on a finishing rack, repairing flaws on the surface of the core and removing unwanted impurities; and 9, detecting the gypsum core before usage of the gypsum core.

Description

technical field [0001] The invention discloses a method for manufacturing a gypsum mold, and in particular relates to a method and a device for making a plaster mold for precision casting of a large aluminum alloy such as a large impeller. Background technique [0002] The integral impeller is the heart of a turbine engine, centrifugal compressor or centrifugal pump. Most impellers have thin walls, twisted blades, complex structures, high dimensional accuracy and surface roughness. In order to obtain impellers with low precision and low surface roughness, advanced plaster molds are required for casting; [0003] At present, the general method of making gypsum cores is as follows: [0004] Step 1 configures gypsum slurry; [0005] Step 2 stirs the gypsum slurry; [0006] Step 3 pouring the gypsum slurry material into the assembled mold; [0007] Step 4: Scrape the top of the gypsum and let it stand to solidify; [0008] Step 5 demoulding; [0009] Step 6 modification; ...

AI Technical Summary

Problems solved by technology

[0012] The internal structure of the impeller is complicated, and the gypsum core cannot be integrally formed by using the traditional method; air bubbles are prone to appear during the stirring process of the gypsum slurry, resulting in the presence of air bubbles inside and on the surface of the produced gypsum mold, which affects the surface quality of the core; The thickness is different, if placed improperly, the core may be partially stressed, deformed, and cracked during the drying process, which will affect the use; the gypsum core is directly placed on the platform, which will reduce the contact area between the bottom and the air and make it easy to dry Incomplete

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