Study On Casting Process Of Ductile Iron Brake Caliper

Brake caliper is one of the most important parts of the automobile brake system.The rough casting is mainly obtained by casting.It bears a great impact in the braking process,should have high strength,high elongation and other characteristics.The material is generally ductile iron,the quality requirements are very harsh,is related to people’s lives and property security components.In the actual production process of casting,brake calipers is easy to produce hole casting defects,such as shrinkage,sand hole and slag hole.In this paper,the formation mechanism of the hole defects in the brake calipers is analyzed and studied,and the improvement measures are proposed to reduce the defects of the holes and improve the quality of the brake calipers.This paper first introduces the casting production conditions and casting process design of brake calipers.It analyzes and studies the process of smelting process,sand mixing process and casting process which affect the hole defects.Due to the modernized casting companies are standardized production line,smelting process and sand mixing process parameters are determined through long-term production verification.If the rush to adjust the parameters will affect the normal production of other products,and casting process design can be based on production experience,with CAE simulation analysis and other measures for the early design.According to the simulation results,we can quickly modify the process and verify.It is the most effective measures to solve casting defects.Therefore,this paper focuses on the improvement of hole defects through the improvement of casting process.The types of defects in brake calipers were analyzed by Metalloscope,X ray inspection,Scanning Electron Microscopy and Energy Dispersive Spectrometer.The formation mechanism of hole defects was analyzed,and the hole defects was reduced by improving the casting process.It involves the design of gating system,the design of riser system,the use of filter which are affecting hole type defects.For brake calipers with riser necking shrinkage defects,balanced flow should be considered in the design of the gating system to avoid temperature field disturbances and ensure that the runner is solidified in time to eliminate the effect of the gating system on the riser pressure,thereby reducing the generation of riser neck shrinkage defects.For the occurrence of sand hole defects in the brake calipers,on the one hand,increaseing the positioning of the core area and setting pressure ring in the sand core structure design;on the other hand,controlling the flow of molten iron to reduce the impact of the molten iron into the cavity in the design of the gating system,to prevent sand into the cavity,thereby reducing the occurrence of sand hole defects.For the occurrence of slag hole defects in the brake caliper,it adopts the gating system which is closed after opening,and the filter net is used to reduce the defect of slag hole.Finally,combined with the characteristics of Hangzhou Ya Teng FBO production line brake calipers production,after a long period of statistical analysis of dat a and a variety of experience,it forms a set of standardization design specifications which are applicable to the enterprise casting process.Thus it shorts the new product development cycle,reduces the rejection rate and improves production efficiency.