Analysis And Optimization Of Structure And Shear Parameters Of 850t Cold Shear

The 850 t cold shear has been widely applied in section material processing fields such as metallurgy,construction,shipping and light industry.In general,the 850 mainly processes bar steel by means of top crops,end crops and dividing shear.Nonetheless,due to the large working load,the large design redundancy of 850 cold shears also exposes its defects such as large volume and heavy weight,which leads to high manufacturing cost and poor working stability.In addition,the shear also has many problems,such as complex working conditions,unreasonable setting of shearing parameters,frequent breakage of shearing edges,increased abrasive wear and so on,which further affects the shearing efficiency and quality.In order to effectively solve the foregoing problems,taking the 850 t cold shear as the research object,this paper combines the corresponding theoretical analysis and numerical simulation technology to optimize its structure and shearing parameters respectively to provide theoretical support for the subsequent design.To put it concretely,this paper mainly carry out the following systematic research from four aspects,including the mechanism simulation of cold shear,static and dynamic,and frame structure optimization as well as shearing parameter optimization:(1)This paper analyzed the motion form of the shearing mechanism of 850 t cold shear.Meanwhile,on the basis of Adams simulation software,this paper established the simulation model of the shearing system of 850 t cold shear,and obtained a series of motion parameters including cutting edge speed,acceleration and displacement,as well as the working load of crankshaft and connecting rod under the most dangerous working conditions,thus providing corresponding theoretical basis for the finite element analysis of the cold shear.(2)This paper established the finite element model of the key components and the complete machine of the 850 t cold shear,and carried out systematic static and dynamic analysis of the key components and the complete machine.On the one hand,through static analysis,this paper determined that the frame structure is an optimizable component.On the other hand,through modal analysis and harmonic responding analysis,this paper concluded the influence of each mode of vibration on the working performance of the cold shear,and the peak value of dynamic load response of key components and the complete machine.According to the analysis results,it indicated that the structure of 850 t cold shear would not cause the sympathetic vibration of the equipment,thus eliminating the problem of poor running stability caused by the machine structure.(3)In order to optimize the weight of the cold shear,this paper established the frame topology optimization model and size optimization model respectively,and conducted topology optimization and size optimization design on the frame of the cold shear.According to the optimization results,the frame mass after topology optimization was reduced by 1429 kg,which was 6.7% less than that before optimization,while the frame quality after size optimization was reduced by 2824 kg,which was 14.2% less than that before optimization.Moreover,the optimized frame met its requirements for static structure and dynamic performance.(4)In the interest of solving the problems of shear edge collapse and rapid wear that often occur when cold shears cut high-strength bar steels in batches,this paper selected five shear parameters including shear clearance,shear speed,overlap,inclination angle of shearing edge and width of shearing edge,and analyzed the influence of different shear parameters on shear force by orthogonal test design method.Furthermore,this paper adopted direct observation method,range analysis and variance analysis to analyze the data,with obtaining the significant degree and contribution rate of the influence of each shear parameter on the investigation index.At last,according to the analysis results,this paper determined the optimal combination of shear parameters.The results indicated that the maximum shearing force of the optimized upper shearing edge was 2872 KN,which was 195 KN lower than that before optimization,while the maximum shearing force of the optimized lower shearing edge was 2906 KN,which was 26 KN lower than that before optimization.Briefly,the maximum shear force borne by the optimized shearing edge was obviously reduced,thus reducing the wear of the shearing edge.And this proved that the optimization was beneficial to prolong the life of the shearing edge and improve the shearing efficiency.