Automobile brake calipers are castings with compactness requirements. In practical application, defects such as shrinkage, shrinkage and porosity can not be found. Based on the actual situation, comprehensive analysis of various factors should be made to optimize theand cast automobile brake calipers with high efficiency. The tensile strength, yield strength and elongation should be controlled within the specified range to maximize the function of brake calipers Give full play to improve the safety, reliability and economy of automobile operation.
Take a car brake caliper as an example, the material is QT450-10, the tensile strength and yield strength are greater than 450MPa and 290mpa respectively, and the elongation is not less than 10% . In the original casting process, the brake calipers are symmetrically distributed, and the feeding risers are located at both ends of the casting and at the center of one side of the casting. The mass of a single blank casting is 3.12kg. The initial pouring temperature of the automobile brake caliper is 1420 ℃, and the pouring time is only 8 seconds. It belongs to the wet casting. The sand core is made of coated sand. The three-dimensional software UG can be used to intuitively present the structure diagram of the automobile brake caliper pouring system. Based on the setting of casting material, sand mold, initial pouring temperature, pouring time, etc., the simulation results are calculated and analyzed, which are applied in modern times On the basis of technology, the filling and solidification process in the casting of automobile brake calipers are analyzed comprehensively and systematically. In the analysis of solidification process, it will be found that when the casting solidifies to 180 seconds, there is an isolated liquid phase area at the bottom. As the cooling continues, the temperature continues to decrease, liquid shrinkage occurs in the molten iron, the riser can not timely and effectively supplement the bottom of the casting, which can not meet the solidification requirements. In practical application, the probability of shrinkage porosity and other defects is particularly high, with the stress concentration The mechanical properties of castings are greatly reduced due to the occurrence of “medium” phenomenon, which is not conducive to the stable operation of automobile brake system. In addition, both ends of the casting are prone to shrinkage and porosity. On the basis of comprehensive analysis, combined with the requirements, process flow and key points of automobile brake caliper casting, the external cooling iron should be directly placed in the bottom of the sand core to speed up the cooling speed and interact with the riser, so as to ensure the smooth realization of the sequential solidification of the casting, minimize the problem of shrinkage and porosity, and optimize Improve the casting technology, improve the performance and quality of the automobile brake caliper.
Casting is an important way to ensure the quality of automobile brake calipers. On the basis of analyzing the problems of brake calipers, we should explore new ideas and methods of casting. In the process of improving the casting process, we should ensure the quality of automobile brake calipers, be able to operate efficiently in a bad working environment, minimize the failure coefficient and application cost, and improve the application efficiency of brake calipers and automobiles Braking effect.