There exist amounts of surface blowhole

shrinkage porosities （holes） in produced aluminum alloy brake oil cylinder

resulting in seriously deteriorating the quality and production rate.Origination of defects occurrence in the brake oil cylinder was analyzed by the ProCast software.The gas hole in the castings is mainly attributed to lower pouring temperature and faster increasing velocity of filling surface.So for the brake oil cylinder with smaller cross section and flange structure

horizontal pouring can smoothly fill the cavity

effectively eliminating the defects resulting from the difficulty to exhaustion.Movable core can narrow the solidification time difference between the center and surface of the castings by greatly improving the heat emission conditions

obviously avoiding the occurrence of shrinkage porosities （holes）.