真空泵和瓦斯泵都有一个形状比较复杂的汽缸.图1及图2是真空泵汽缸的断面图,从图中可知这种汽缸有两层复杂的串皮坭心.在技术条件方面,要求抗拉强度为21公斤/公厘~2以上,布氏硬度183~235,水压试验是13公斤/公分~2,气压试验是5公斤/公分~2,加工以后缸体不许有任何砂眼、缩孔、夹渣等缺陷,所以铸造相当困难.我厂经过多次试制失败,最后终於铸造成功,现将铸造工作中的一些经验介绍给大家,藉供参考. Vacuum pumps and gas pumps have a more complex shape of the cylinder.Figure 1 and Figure 2 is a vacuum pump cylinder cross-sectional view, we can see from the figure of this cylinder has two layers of complex crocodile 坭 heart in terms of technical requirements, tensile Strength of 21 kg / mm ~ 2 above, Brinell hardness 183 ~ 235, hydraulic test is 13 kg / cm ~ 2, pressure test is 5 kg / cm ~ 2, after processing the cylinder shall not have any trachoma, shrinkage , Slag and other defects, so the casting is quite difficult. I plant failed trial after many trial, and finally finally foundry success, casting work is now some of the experience introduced to you, for reference.