Numerical Simulation Of Integral Hot Runner Second Nozzle Limit Length Based On Finite Element

After decades of development, in plastic injection molding mold industry the hot runner technology has been playing an increasingly important role. Application of hot runner technology to improve production efficiency, saving raw materials, reduce costs, enhance the level of automation, etc., known as green manufacturing in plastics industry. But in recent years, it is widely used integral hot runner systems in actual production, often occur molten plastic leak or second hot nozzle break, which directly affect the production and cause economic losses.In this paper, the question of second hot nozzle break in integral hot runner systems has been start depth theoretical analysis and technological research. Fusion theory of heat transfer, mechanics of materials, etc. holistic integral hot runner systems of automotive trim slip (second hot nozzle outer diameter of 25mm, length 189.5mm) for the study, construction of second hot nozzle break model, set different center distance L and secondary heat nozzle length h proportional parameter, the main influencing factors of limit length coefficient on the second hot nozzle a [is (L/h)] were analyzed, make full use of the finite element AN SYS Workbench powerful analytical capabilities and multi-physics coupling function, numerical simulation under various setting conditions, determine second hot nozzle limit length of the coefficient a and optimization, finally, design-related experimental program for further verification. The main contents are as follows:(1) Through theoretical calculation, use elimination method, summarized second hot nozzle break reason, construction break model. Discuss second hot nozzle break or leakage in hot runner system, summarized factors leading to second hot nozzle break under actual load conditions and environment are:threaded connection, load temperature difference, impact the valve needle, injection pressure. On the basis of detailed calculations and analyze for each of the factors, construction second hot nozzle numerical simulation model.(2) Numerical simulation, solving to determine second hot nozzle limit length theoretical value of the coefficient a. Mainly use of finite element analysis platform, ANSYS Workbench, at different heating temperatures, hot nozzle deflection or center distance Land second hot nozzle length hratio parameter variables, respectively integral hot runner system simulation, distribution of its surrounding temperature field, stress field, strain field. In each simulation analysis, utilizing the principle of control variables, respectively one of the factors as variables discussions.(3) Formulate relevant experimental conditions to verify. Building similar test platform to the actual application, Change heating temperature of integral hot runner system, second heat nozzle diameter, reduce the length of the nozzle to three sets of experiments, numerical simulation data for the reliability of data collection. Experimental and simulated data were fitted binomial, from fitting match ratio reliability of data can be drawn. Verification results show:experimental data and simulation data are basically consistent trends are basically the same.(4) Establishment empirical of limit length coefficient a. Analysis relevant numerical simulation and experimental data, focus on the influence of thermal deformation break on center distance and the relative of the ratio between second hot nozzle length, establish second thermal limit length of nozzle coefficient a empirical formula, provide theoretical guidance for design of integral hot runner systems.This study is of positive significance to integral hot runner systems application in the plastic injection mold.