Research On Key Technique For Three-Roll Y-Type Mill

The most promising engineering material is magnesium alloy,and the rolling process has the better comprehensive performance in all of the plastic forming technologies of magnesium alloy.However,further research is needed on the optimization design of the magnesium alloy bar mill.Because of the abnormal vibration,low cooling efficiency and lubricating oil seepage observed in the actual rolling process of the three-roll Y-type mill,the paper focuses on analyzing the torsional vibration of the rolling mill's main drive system,working out the convective heat transfer coefficient of the cooling fluid&the roll surface and improving the oil-water separation system.The main tasks are as follows:1.Establish the dynamic model of the torsional vibration of the three-roll Y-type rolling mill's main drive system according to the relative basic theory in the mechanical dynamics,derive a torsional vibration dynamic equation,and calculate the equivalent inertia and equivalent stiffness of each component in the system.Then the natural frequency and the corresponding main vibration model of the three-roll Y-type mill is worked out by MATLAB.The data obtained can be used for designers to design the structure and prevent torsional vibration.The torsional vibration suppression of the rolling mill is analyzed on two aspects:the raising of the natural frequency and the weakening of the vibration source.2.Use FLORTRAN CFD to analyze the flow heat coupling of the cooling liquid and the surface of the roll;illustrate the finite element theory,the jet characteristics of the nozzle and the boundary conditions;complete the finite element analysis by setting different initial parameters of the temperature of the coolant,the distance between the nozzle and the roller surface,the injection rate of the coolant,the injection angle and the viscosity of the coolant;obtain the influence of different factors on the convective heat transfer coefficient of the cooling liquid and the roll surface and sort all of the factors by orthogonal test;improve the cooling efficiency according to the results.3.Improve the oil-water separation system of the rolling mill on three aspects:the workshop structure of the continuous rolling mills,the structure of the three-roll Y-type mill,the moisture content monitoring of the lubricating oil;guarantee that the coolant is effectively separated from the oil,and that the coolant and the lubricating oil could be reused by the respective circulation system.The entity model not only improves the production environment,but also prolongs the service life of the bearing and promotes the rolling quality.It has a vital significance on engineering that the research results applied to the rolling process of the magnesium alloy bar could effectively avoid abnormal vibration,the low cooling efficiency,the lubricating oil and coolant mixing and other issues.