Abstract:

：To against the uneven cooling of traditional hot stamping tool with opposite deep-hole drilling cooling system, a new design method of hot stamping tool with conformal cooling channels is put forward, which is based on multi-field couplings in heat transfer theory and simulated by Star-ccm+. By taking the insert of a B-pillar tool on the self-developed rainbow electric car as the research object and comparing the cooling effects of traditional hole drilling and some newly proposed cooling designs, a new optimization strategy for B-pillar tool insert with longitudinal conformal cooling channel arrangement is applied and the temperature distribution of work surface before and after optimization has been analyzed. Hot stamping tool with conformal cooling channels is fabricated by means of combining 3D printing technique of precoated sand with traditional sand casting. This hot stamping tool with optimized longitudinal conformal design overcome the cooling limitations of parallel conformal designs, such as maximum temperature of work surface decreases by 47.4%, average temperature decreases by 40.9% and temperature uniformity improves by 1.8%. According to the design process of longitudinal conformal cooling channel, the parameters of channel shape and location such asR, H, rare set as optimization variables and the surface temperature field will serve as the optimization object. The optimization result shows that the maximum temperature of work surface decreases by 49.8%, and the average temperature decreases by 46.8%, and the temperature standard deviation decreases by 67.5%, while the temperature uniformity increases by 1.9%. It is found that this hot stamping tool with conformal cooling channels upgrades production efficiency and prolongs service life-span, furthermore, the uniformity of mechanical properties of hot stamping parts is improved.

Key words: 3D-printing, conformal cooling channels design, coupled simulation, sand casting, hot stamping tool