缸体缸盖铸件的基准点稳定性及缸筒变形问题——车用中小型发动机灰铸铁缸体缸盖铸件生产工艺(5)

On Problems with Base Point Stability of Cylinder Block and Head Castings and with Cylinder Holes Deformation——Casting Production Technology of Gray Iron Cylinder Block and Head for Medium-Small Vehicle Engine (V)

缸体、缸盖的基准点往往由于造型工艺过程、设备工装状况、浇注液流流量和速度、砂芯与砂型相对位置等诸多因素的波动而发生偏移,为此必须对模具的基准倾向进行修正,并且要定期对模具基准点进行监控与维护。铸件结构不合理、铸造工艺不合理、加工工艺和装配工艺不合理都可能使铸件存在残余应力而引起缸筒变形,必须在这几个方面采取相应措施才能解决。

The base point of cylinder blocks and heads may be offset sometimes from correct position due to the fluctuation of many factors such as the molding process, state of equipments and pattern toolings, pouring flow rate and velocity, and the relative position of the core and mould, and so on. In order to solve the problem, the tendency of the pattern base must be corrected, and the base point of the pattern must be monitored and maintained at regular intervals. All improper casting construction, improper casting method, improper machining process and assembling process may cause the casting to have residual stress which would cause the deformation of the cylinder holes. The problem can be solved only by adopting corresponding measures in above mentioned aspects.