Because the cold core box is made by blowing resin sand, in the specific production, in order to make the edges and corners of the sand core clear enough, it is necessary to make the sand core have good compactness, and the gas discharge speed in the core box should be greater than the calculated speed. In order to achieve this effect, in the process of processing around the sub box and ejection hole, a gap and exhaust slot with a depth of 0.25mm need to be reserved to strengthen the exhaust effect. At the same time, during the manufacturing process, the surface of the core box should also be cleaned frequently to prevent the rough surface of the core or scarring.
In the process of core gas storage and cleaning, it is necessary to control the gas generation of raw materials and ensure that the core exhaust is smooth enough, especially the core head, which needs to increase the contact of sand core. Because the water jacket core can drill holes inside the core, it is easier to form a ventilation network inside it, so it can be applied to the cylinder core to achieve a good hollow effect and provide sufficient convenience for gas circulation. In the process of core cleaning, special attention should be paid to the cleaning of burr and flash, so as to effectively avoid the dent of automobile engine cylinder block casting and ensure its quality.
In addition, in the specific core manufacturing process, the coated sand also needs to be used correctly. The coated sand can be purchased directly or the medium sand with good fluidity can be selected to realize the omission of coating and resource saving; Moreover, the coated sand cannot be stored for a long time in application, so as to effectively prevent the core cracking or even damage caused by sand particle separation.