Simulation of filling speed error in sand casting of machine tool bed

Sand casting is a casting method in which metal liquid fills the mold cavity under the action of gravity. Iron and steel and many alloy materials in life can be produced by sand casting. Sand casting has many advantages:

① It can produce various large and complex blank parts such as box, frame and bed;

② It can cast a few grams of objects or hundreds of tons of objects;

③ The materials used are from a wide range of sources and the cost is relatively low;

④ Sand casting has high precision and can reduce the allowance of finishing.

Therefore, sand casting has been widely used in the foundry industry. At present, the sand casting process is also constantly improving and perfecting. For example, the mold filling process of sand casting is simulated by casting simulation software. The casting model of machine tool bed is created. Combined with the process characteristics and theory, the gating system and casting process are designed. The casting filling process is simulated, and the process parameters of simulation curve are obtained. The parameters are optimized, which can be used to predict the surface defects of castings and improve the casting efficiency. The casting process of machine tool bed is optimized by simulation software. According to the calculation results of the software, the influence of process parameters on casting deformation is obtained. The simulation results show that the optimal filling temperature, filling speed and casting thickness of machine tool bed casting are obtained. After optimization, the shrinkage cavity of the casting can be avoided, which meets the needs of practical casting. However, few people used to study the sand casting control method of machine tool bed in the past. Sand casting is adopted for the machine bed. If the filling speed of liquid metal is not controlled properly, it will lead to uneven distribution of thermal stress in the process of casting filling, and finally affect the surface quality of casting. In this paper, the production process of sand casting process for machine tool bed is studied, the sand casting process flow chart is given, the calculation model of sand casting filling speed is constructed, the filling speed of sand casting is controlled by PLC, and the error of filling speed is simulated by MATLAB software. At the same time, the simulation results are compared with the traditional PI control mold filling speed error, which provides a reference for the research on the control of mold filling speed of machine tool bed sand casting.

The casting process of machine tool bed and the simulation results of mold filling speed error controlled by PLC were studied by sand casting. The technological process of sand casting of machine tool bed is analyzed, the filling speed equation of sand casting is established, the principle diagram of PLC control filling speed of measurement and control system is designed, the filling speed error is simulated by MATLAB software, and the simulation results are compared and analyzed with those of PI control filling speed error. The simulation results show that the filling speed error controlled by PLC is small and the phenomenon of stress concentration is avoided.

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