我厂生产的汽车刹车毂铸件,采用底注式浇注,合箱后,在砂型上方需设置两个出气冒口圈(见图1)。过去,我们使用的出气冒口圈,是用型砂在直径为80mm、高为100mm,厚度为2～3mm的铁圈内制成的漏斗型铁圈冒口。这样,在进行批量生产时,就需要大量的铁圈(每箱两个)。另外,为了便于回收冒口铁圈,需要在浇注后不久就敲下铁圈,而此时铸件尚未完全凝固,敲 I plant the production of automotive brake hub castings, using the bottom of the note pouring, after the box, the sand above the need to set up two outlet riser ring (see Figure 1). In the past, the outlet riser we used was a funnel-type ironhead made of sand with a diameter of 80mm, a height of 100mm and a thickness of 2 to 3mm. In this way, a large number of hoops (two per case) are required for mass production. In addition, in order to facilitate the recovery of the riser ring, you need to knock the iron ring shortly after pouring, while casting has not yet fully solidified, knocking