A special coating sand for engine cylinder water jacket and preparation method thereof

Abstract

The invention discloses special precoated sand of an engine cylinder block water jacket and a preparation method of the special precoated sand. The special precoated sand of the engine cylinder block water jacket comprises roughing sand, a binding agent, a curing agent, a coupling agent, a lubricating agent and fire resistant particles, wherein the binding agent accounts for 1 to 4% of the roughing sand in weight, the curing agent accounts for 10 to 20% of the binding agent in weight, the coupling agent accounts for 0.1 to 0.5% of the binding agent in weight, the lubricating agent accounts for 1 to 5% of the binding agent in weight, and the fire resistant particles account for 0.1 to 2.0% of the roughing sand in weight. Compared with the prior art, the special precoated sand of the engine cylinder block water jacket has the advantages of strong capability of veining and sintering prevention, high intensity, good flowability and good heat resistance, the quality of the inner and outer surfaces of the engine cylinder block water jacket is effectively improved, and the special precoated sand is suitable for being used for producing the engine cylinder block water jacket.

Description

technical field [0001] The invention relates to a coated sand, in particular to a coated sand applied to a water jacket of an engine cylinder block, and also relates to a preparation method of the coated sand. Background technique [0002] Coated sand refers to the molding sand or core sand that is covered with a solid resin film on the surface of the sand grains before molding. There are two commonly used coating processes today: cold method and thermal method: the cold method dissolves the resin with ethanol, and adds urotropine during the sand mixing process, so that the two are coated on the surface of the sand, and the ethanol volatilizes to obtain a coating Sand: Preheat the sand to a certain temperature by thermal method, add resin to melt it, stir to coat the resin on the surface of the sand, add urotropine aqueous solution and lubricant, cool, crush and sieve to obtain coated sand. Because coated sand has the advantages of high strength, low gas generation, high di...

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Problems solved by technology

[0003] However, the coated sand prepared by the above two coating processes has some shortcomings in practical application: the coated sand is prone to veining and sintering in the process of casting the engine cylinder water jacket.

Although the coated sand can significantly reduce or eliminate defects such as veins, sticky sand, and pores, and effectively improve the quality of the inner and outer surfaces of castings, the coated sand contains too many components, and the application document does not indicate that each component Influence of the content of components or components on the properties of coated sand

This prior art also discloses the preparation method of the coated sand, which is too complicated and the conditions are harsh, which is not conducive to its reproducibility

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