【摘要】 运用伯努力方程计算出负压消失模铸造在浇注时直浇道与浇口杯接口处会出现比砂箱内的负压还高的真空度,在这一高真空度的作用下很容易把直浇道与浇口杯之间接口处的干砂吸入直浇道中,给铸件造成白色缺陷。解决的办法是:由于这一真空度高于砂箱内的值,故可不考虑该处涂层的透气性,增加其涂层厚度及强度以阻挡型砂流动,或者把直浇道与浇口杯制成一体,这样问题就得以解决了。更多还原

【Abstract】 This text using equation of Bernoulli calculates out that cast will come out the higher vacuum degree in the interface of vertical path and pouring jaws cup than the negative pressure of sand box.In this function of high vacuum degree, the dry sand will be inhaled easily to the vertical path, which will engender the white disfigurement.The solving method of it is that the ventilative property of coat should be taken no account of whicn can increasing thickness and intension to block off the flow of mould sand or making vertical path and pouring jaws cup into a whole because of this vacuum degree is higher than sand box. So the problem will be solved.更多还原