Large propeller mesopore loam core and casting fastening tool thereof

Abstract

The invention discloses a large propeller mesopore loam core. A circular-truncated-cone-shaped riser section and a body section are adjacently arranged on the outer circumferential face of a central steel pipe in the vertical direction, the riser section is filled with first material sand, the body section comprises an inner layer and an outer layer, and the outer layer comprises at least two subsections A which are adjacently arranged in the vertical direction in sequence; each subsection A comprises a plurality of strip-shaped chilling blocks evenly distributed in the circumferential direction, a gap is formed between every two adjacent strip-shaped chilling blocks in the circumferential direction, the number and thickness of the strip-shaped chilling blocks on each subsection A are thesame, the gaps between the strip-shaped chilling blocks are equal, and the inner layer and the gaps are filled with second material sand; and meanwhile, the invention discloses a fastening tool for casting a large propeller through the mesopore loam core. By improving the structure and the materials of the mesopore loam core and improving the fastening tool for the mesopore loam core during propeller casting, the defects of shrinkage porosity, shrinkage cavities, air holes and the like in propeller casting are greatly reduced, the phenomena that copper enters the mesopore loam core and the mesopore loam core is affected by environmental humidity are obviously avoided, and the fastening tool has universality, convenience, firmness and safety.

Description

technical field [0001] The invention relates to the field of propeller casting, in particular to a medium-hole clay core for large-scale propeller casting and a casting fastening tool thereof. Background technique [0002] Casting center hole quality control is an important part of the propeller casting process. With the development of science and technology, propeller design tends to become larger and more complex, which will undoubtedly bring unprecedented difficulties and challenges to propeller center hole quality control. [0003] In the existing propeller casting process, the propeller mesopore mud cores are all made of sodium silicate sand. In order to increase the overall strength of the mud core and facilitate sand hanging and lifting, a steel pipe is placed vertically in the middle of the mud core, and the outer circumference of the steel pipe is welded with some round steel from top to bottom for reinforcement. By directly welding the upper end of the steel pipe ...

AI Technical Summary

Problems solved by technology

[0005] 1. If the quality of casting holes is not well controlled, casting defects such as shrinkage cavities and shrinkage porosity are prone to occur, and subsequent mechanical scribing adjustments are time-consuming and laborious. At the same time, in order to deal with defects, "welding repair-processing-welding repair ” and other rescue operations will greatly affect the processing efficiency, which may seriously lead to the scrapping of the propeller;

[0006] 2. Since the mud core is all water glass sand, there is no chilling effect, and the area close to the middle hole belongs to the casting hot pitch circle area, and the middle hole is prone to shrinkage cavity and shrinkage defects;

[0007] 3. When pouring, the mud core is prone to copper drilling, that is, copper water is easy to enter the inside of the mud core. Once the copper water enters the mud core, the defects of the middle hole may exceed the standard, the middle hole is out of round, and the middle hole is eccentric. , which can seriously lead to the scrapping of the propeller;

[0008] 4. Affected by the water glass sand material itself, the mud core is sensitive to changes in environmental humidity. In humid weather, the surface of the mud core is easy to pulverize and fall off, and the strength fails. In extreme cases, the mud core needs to be remade when it is scrapped;

[0009] 5. Affected by the water glass sand material itself, during the pouring process, the gas inside the mud core will invade the copper water when the middle hole is at a high temperature for a long time, which will easily cause pore defects;

[0010] 6. For large propellers, this kind of mud core is likely to cause poor feeding effect in the riser area, thus easily causing shrinkage cavity defects;

[0011] 7. The material properties of sodium silicate sand and steel pipe and round steel are different. Therefore, during the high temperature and cooling process of the mud core, the shrinkage characteristics of the two materials are different, resulting in a decrease in the strength of the mesopore mud core and an increase in the probability of copper drilling, which seriously affects the hole quality

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