Design And Analysis On Chip Breaking Device Of Active Mechanical Power

As a typical material of manufacturing and machining industry,304 stainless steel has such properties as high plasticity,high toughness,high strength,good corrosion resistance,and suitable price.However,these encounter such difficulties as significant increase of cutting temperature and severe wear of cutting tools in the machining process.At the same time,the continuous winding of cutting chips around the cutting tools or machine tool parts causes production safety hazards,disrupts the production rhythm and affects production efficiency,which greatly restricts the reliability and production efficiency of the automatic production line.After absorbing the ideas of other scholars on chip breaking,In view of the difficulty of chip breaking in the material turning represented by 304 stainless steel,a chip breaking device with active mechanical power is designed,then applied and obtained an authorized invention patent.The device is fixed on the square tool holder of lathe by wooden fixture.The internal chip cutter with two cutting edges is driven by DC motor to get rotary motion,and the external chip cutter with two cutting edges is combined to break the chips flowing through the chip cutter slot,so as to solve the problem of continuous winding of chips and improve the key parameters such as cutting heat,cutting force and surface quality in the cutting process.In this paper,the method of theory,simulation and experiment is used to analyze and verify the optimization effect of chip breaking device with active power in 304 stainless steel cutting process.Firstly,the theory,model and method of matching research are used to analyze and study chip breaking mechanism of the active mechanical power chip breaking device.In the process of auxiliary 304 stainless steel cutting,the chip is driven by the chip cutter,then to pull the chips away from the rake face,thus reducing the contact area of the tool-and-chip,then reducing the cutting heat and cutting force to a certain extent.Because of the forced shear action of the chip breaker,strain of the chip increases rapidly and instantaneously,then the chip is broken into small segments,It avoids the long chip scratching the machined surface,producing scratches and ploughs,so as to improve the cutting condition.Secondly,determine the chip breaking scheme adopted in the study,the preparation method on chip breaking device of active mechanical power is analyzed.Through the theoretical analysis of chip flow angle model,combined with the range of cutting parameters used and the geometric angle of the tool,the flow path of chip on the rake face of the turning tool which under various cutting parameters is obtained with the help of MATLAB software,so as to guide the spotting of chip cutter before simulation and experiment.Thirdly,the orthogonal experiment of four levels and three factors is designed,the order of influence weight of each parameter and the optimal combination of cutting parameters are determined by range analysis.Using the 3D turning module "CUTTING 3D" of Deform 3D,a professional 3D metal cutting simulation software,the difference of the chip shape,the maximum temperature of the rake face and the main cutting force between the dry cutting and the auxiliary cutting of the active mechanical power chip breaking device are compared.The simulation results show that the frequency of chip breaking is greatly increased by using the active mechanical power chip breaking device,the maximum temperature of the rake face is reduced by at least 10%,and the main cutting force is reduced by about 40-90 N.Finally,the difference of chip shape,temperature of the tool rake face,main cutting force and machined surface roughness under the two cutting conditions are compared by orthogonal experiment.In addition,the single variable method is used to study the influence of different cutting parameters on chip shape(length,radius of curvature,pitch),maximum temperature of the tool rake face,main cutting force and machined surface roughness.The experimental results show that the speed of chip breaker is primary factor affecting the frequency of chip breaking,With the help of active mechanical power chip breaker,the chip length can be significantly reduced,and the cutting heat,cutting force and machined surface roughness can be improved to varying degrees.