Research On The Factors Affecting The Shear Blade Life Of 850 Tons Cold Shearing Machine

As one of the important auxiliary equipment in the rolling process of metallurgical industry,shearing machine has been widely used in bar production line and has an irreplaceable position.As one of the shearing machines,cold shearing machine has become the mainstream shearing equipment of small and medium-sized rolling for its shearing force will not be transmitted to the foundation,simple shearing structure,easy maintenance,low energy consumption and high efficiency.The shear blade of 850 tons cold shear in a small rolling mill often appears the phenomenon of blade collapse,blade breakage and blunt grinding too fast when shearing high-strength threaded steel bar,which reduces the life of the shear blade and seriously affects the production efficiency.Aiming at the problems in shearing of cold shear,this paper takes 850 tons cold shear as the research object,firstly calculates the force and energy parameters based on shearing theory;secondly,uses Solidworks software to build three-dimensional model of shearing screw bar of cold shear under actual shearing parameters,and uses ANSYS/LS-DYNA to analyze the shearing process of shear blade.The results show that the shear stress-strain and shear force of the upper and lower shear blade are the greatest,resulting in frequent blade breaking and blunt grinding.The shear parameters are the main factors affecting the life of the shear blade.Based on the weighted average method,the five most influential shear parameters are determined: the shear gap,the inclination angle of the shear blade,the width of the shear blade face,the shear speed and the overlap of the shear blade.The control variable method is used to analyze the maximum stress-strain and the maximum shear stress-strain of the shear blade affected by the five shear parameters By optimizing the shear parameters of the cold shear,the maximum stress-strain and the maximum shear force are reduced,and the service life of the shear blade is prolonged.Finally,the fatigue life of the shear blade after optimizing the shear parameters of the cold shear is analyzed.It is shown that the life of the upper shear blade is increased by 31.6%,and the life of the lower shear blade is increased by29.1%.The research results of this paper have been applied in the field,effectively prolonging the service life of the shear blade,greatly reducing the number of replacement of the shear blade,and improving the production efficiency.It has certain guiding significance for the actual production,and provides theoretical reference for the design and manufacture of cold shears.