Mold core preparation method of closed twisted blade

Abstract

The invention discloses a mold core preparation method of a closed twisted blade. The mold core preparation method comprises the following steps: a, firstly, modeling and designing a model of an impeller in a product drawing; B, after the step a is completed, increasing blank allowance and patching holes (hubs) for a product according to the technical requirements of machining, and performing shrinkage rate treatment according to the types of impeller alloys to obtain a blank A; and c, after the step b is completed, rotating and modeling the outer contour line of the blank in the blank A to produce a solid model. The invention aims to provide the combined impeller sand core for casting production of the impeller, the sand core has the characteristics that the blade molded surface structure completely meets the distortion and rotation characteristics of design requirements, the size precision is high, the surface is smooth, due to the combined sand core, exhaust is smooth through the combined surface in the pouring process, the defects of insufficient blade pouring and cold shut are avoided, waste products are reduced, and the cast impeller with excellent performance is obtained to reduce the resistance of a pump and improve the efficiency of the pump.

Description

technical field [0001] The invention relates to the technical field of casting technology, in particular to a method for preparing a core of a closed twisted blade. Background technique [0002] The impeller is an important working part of the pump and the heart of the pump. The closed impeller consists of a front cover, a rear cover and blades, the blades are sandwiched between the front and rear cover layers, and the complex blade structure is twisted and rotated. When casting the impeller, the blades need to be formed with sand cores, and the quality of the sand cores directly affects the working efficiency and life of the pump. [0003] The traditional core-making process is to first process the independent metal blade and the front and rear cover plate models. When making the core, the blade is fixed on the rear cover plate. When the blade is taken out from the sand mold, it is affected by the curved surface structure, and the curved surface structure is severely defor...

AI Technical Summary

Problems solved by technology

[0003] The traditional core-making process is to first process the independent metal blade and the front and rear cover plate models. When making the core, the blade is fixed on the rear cover plate. When the blade is taken out from the sand mold, it is affected by the curved surface structure, and the curved surface structure is severely deformed. The wall thickness is increased, the structure is approximately planar, and the shape of the blade is quite different from the design requirement, and the surface roughness value is large. Since the blade is thin and rotates, it is impossible to reduce the surface roughness value by brushing paint, which will cause water to increase during use. The resistance of the pump affects the efficiency and life of the static balance of the pump; at the same time, due to the difficulty of exhausting the integral sand core during the casting process, it is easy to cause insufficient pouring of the blades and cold shut, resulting in waste products

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