Casting technology design method of high-grade vermicular graphite cast iron cylinder cover

Abstract

The invention discloses a casting technology design method of a high-grade vermicular graphite cast iron cylinder cover. A one-box two-piece vertical pouring technology is adopted, and the method comprises the following steps that S1, the situation that a pouring system is in a middle pouring type is determined, the pouring system is designed between two combined cores, and the completely wrapped sand core design is adopted; S2, the position of a flow gate is determined, wherein the position of the flow gate is arranged nearby a hot joint part of a casting bolt hole; and the pouring system is designed on the bottom surfaces of base plate cores, a half pouring system is formed on the bottom surface of each of the two base plate cores, and complete pouring system is formed on the bottom surfaces of the two base plate cores after core combination is accomplished; S3, an exhaust system forming mode is determined; S4, a chiller-free technology is adopted; S5, all the sand cores of the cylinder cover are assembled and combined, and are locked through a core locking threaded rod, then core setting and box assembling are carried out, and an assembly waits for pouring; and S6, casting pouring is conducted. The method has the advantages that the cost is low, the production efficiency is high, the casting shrinkage cavity and porosity rejection rate is controlled to be 2% or below, and the rejection rate is low.

Description

technical field [0001] The invention relates to the technical field of cylinder head casting, in particular to a casting process design method for a high-grade vermicular graphite cast iron cylinder head. Background technique [0002] The cylinder head is an important part with the most complex structure and high technical content in the engine. In the past, the mainstream materials for the cylinder head of medium and heavy engines were ordinary gray cast iron, chrome-molybdenum-copper alloy gray cast iron, and low-grade vermicular graphite cast iron. With continuous improvement, the wall thickness of castings is becoming lighter and the structure is becoming more compact, and the compression ratio and power are increasing day by day, which puts forward higher requirements for the material performance of the cylinder head. The performance of the gray cast iron / low-grade vermicular iron cylinder head can no longer meet the above requirements. . Compared with gray cast iron / l...

AI Technical Summary

Problems solved by technology

[0006] The disadvantages of the casting process design method in the existing technical solutions: First, a large number of cold iron processes are used in hot joints such as cylinder head bolt holes, conduit holes, and fuel injectors to improve shrinkage and shrinkage defects, which affects production efficiency and increases costs accordingly The second is that the design of the gating system is not in place, and the design standard has not been improved with the upgrading of the material. According to the usual gating system design, it does not have an effective feeding function, which directly leads to shrinkage cavity and shrinkage defects in the hot joint of the casting; Sand core and cavity exhaust system design is not perfect, the design standard has not been improved with the upgrading of materials, the sand core exhaust function is not paid attention to, and some sand cores do not have exhaust channels, resulting in inner cavity sand cores during the pouring process. The gas cannot be discharged in time and is involved in the molten iron, causing gas shrinkage defects at the hot joints; the fourth is the high rate of shrinkage voids and porosity

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