Mold core arbor for heterogeneous valve body

Abstract

A heterogeneous valve body core frame, having a hollow tube core frame; holes of different sizes are non-uniformly arranged in the wall of the core frame; the holes comprise: more than one big hole (1) formed in at least one local area in the wall of the core frame, and more than one small hole (2) formed in at least another local area on the wall of the core frame; the area of a big hole (1) is greater than that of a small hole (2); the sectional load-bearing capability in the local area where the big holes (1) are formed is smaller than that in another local area where the small holes (2) are formed. The heterogeneous valve body core frame ensures that the core has uniform stress on each section while satisfying strength and rigidity requirements so as to have uniform strain, and can effectively reduce the obstruction in a shooting process, thus reducing the machining allowance and subsequent machining difficulty, and achieving higher product qualification.

Description

technical field [0001] The invention relates to a core bone of a valve body, in particular to a core bone of an inhomogeneous valve body. Background technique [0002] Such as figure 1 As shown, in an existing implementation mode, most of the existing valve body core core bone adopts a hollow tubular structure, such as figure 2 As shown, another existing implementation, such as the Chinese utility model patent CN 201728336U discloses a large-scale excavator ultra-high-precision multi-way control main valve body sand mold, wherein a hollow core bone is embedded in the core, and the hollow The surface of the core bone is a honeycomb shape with evenly distributed small holes, which can improve air permeability. These core bones for valve body cores are all simple homogeneous core bones. The basic purpose is to enhance the strength of the core. For valve body cores with simple structures and general shapes, it can basically ensure that the core has good air permeability when ...

AI Technical Summary

Problems solved by technology

[0003] However, for valve bodies with complex shapes and high precision requirements, although this type of homogeneous core bone improves the strength of the core, the reinforcement is uniform, but the stress on the core is still uneven, resulting in The strain is of course also different, which eventually leads to uneven deformation of the casting, uncontrollable error, affects the quality of the casting, and causes an increase in the post-processing allowance or processing difficulties

Usually, this kind of core bone will also have a certain hindering effect on sand shooting, which will cause unrealized sand shooting due to insufficient sand shooting, affect the quality of sand molds, and eventually lead to defects in valve body castings

[0004] This kind of simple homogeneous core bone only considers factors such as core strength and air permeability from the perspective of experience, but does not specifically analyze the core structure, ignores factors such as uneven deformation after stress, and does not conduct a comprehensive analysis of the sand shooting situation.

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