Technology Of Liquid State Forging For Air-Conditioner Swaying Tray Of Automobile And The Design Of The Die Set

Based on the technology of liquid die forging, the technology of air-conditioner swaying tray of automobile and the die set is investigated. According to the structure, the size and the operation of air-conditioner swaying tray, experimental equipment including preheated temperature and quantitative scoop is designed and experimental programme is made by controlling other parameters invariant and admitting a parameter variant. At the same time, important technological parameters of experiment are optimized, and operating instructions and requires are studied. The optimized parameters of the die set of swaying tray show that single clearance between female die and male die is 0.1mm, pattern draft of male die is controlled of 1~2°, punch-die and five pins are made of 3Cr2W8V alloy steel which can reach HRC 48~52 by controlling the heat-treating and the others are made of 45 steel. Preheating system of the die set of swaying tray is heated by adopting Cr20Ni80 resistance wire, as diameter d is 1.5mm, node-pitch D is 36mm, screw-pitch h is 4mm, spiral column L' is 0.91m, 220V single-phase contacting is adopted. Column is used in the quantitative scoop, as diameter of basal plane is 41mm and height is 51mm. Liquid state forging creates a way in advanced quality and high production. In common place, workpiece is showed that internal structure is tight, surface is luster and mechanical property is good. In practice production, a lot of defection is produced. Shrinkage property, shrinkage cavity and crack are the primary defection of swaying tray, which can appear in the keyway and near the bottom angle of the five round desk. It can decrease the shrinkage porosity and shrinkage cavity by heightening the pouring temperature and the preheated temperature, accelerating the velocity, extending the holding pressure time. Forming the shrinkage property and shrinkage cavity accompanies with precipitating the gas from the liquid of aluminium. It can decrease the production of air hole by controlling the stableness of the velocity when female die contacted the liquid of aluminium. By means of measuring room temperature mechanical properties and analyzing microstructure and fracture, it is shown that microstructure is very condense, Si grains are very fine and have no phenomena of coarsening. Mechanical properties are best by taking the optimal technical parameters of 740℃pouring temperature, 250℃preheated temperature of die set and 1850kN pressure (139.45Mpa). Taking the optimal technical parameters, the hardness of swaying tray can attain HV0.1≥100, the strength can attain σb≥310Mpa and the plasticity can reach 5%.