| 304 stainless steel,316 stainless steel and other materials are widely used in manufacturing and machining industries because of their high toughness,high strength and excellent corrosion resistance.However,in the process of processing such materials,the cutting temperature is high,the tool wear is serious,and the tool service life is low.Moreover,the chips generated in the cutting process of 304 stainless steel and 316 stainless steel are easy to pile on the rake face of the turning tool,or even wound on the workpiece or tool,which poses a certain threat to the safety of the operator and the machine tool,and has a very serious impact on the production efficiency.In order to better control the long chips generated in the cutting process,this study absorbed and borrowed the ideas and ideas of domestic and foreign researchers on cutting chip breaking,and designed an external chip breaker to solve the long chips generated in the cutting process of 304 stainless steel,316 stainless steel and other materials.As the carrier of the whole external chip breaker,the wooden base is fixed on the lathe square tool rest,and the speed regulating motor drives the cutter to rotate to interrupt the chips flowing through the rake face,so as to better solve a series of problems caused by the lengthy chips in the production process.The method of theoretical analysis,simulation and experimental verification is used to improve the chip breaking effect of 304 stainless steel,316 stainless steel and other materials under the auxiliary cutting condition of external chip breaker,and further optimize the cutting heat,workpiece surface roughness and other related parameters in the cutting process.Firstly,the theory,model and method of the experiment are analyzed,and the chip breaking mechanism of the external chip breaker is studied.The external chip breaker is used to cut 304 stainless steel.In the process of chip flow,the rotary motion of the cutter is interrupted,and the chip is pulled away from the rake face,so that the contact area between the cutter and the chip is reduced,and the cutting heat and cutting force are reduced to a certain extent.At the same time,due to the external force of the chip breaking cutter,the chip strain increases rapidly,and the chip is forced to break into broken chips with short length,The continuous and winding chips are avoided to scratch the machined surface,so the cutting condition is improved.Secondly,considering the operability and feasibility of the experimental device,the external chip breaker used in the research is determined,and the design idea of the external chip breaker is analyzed and discussed.Based on the analysis of the theoretical model of chip flow angle,combined with the cutting parameters range and the geometric angle of the tool,the position of the cutter in the rake face is further determined in the simulation and experiment.Thirdly,the 3D cutting module "3D cutting" in deform is used for simulation.The orthogonal experiment with four levels and three factors was designed to machine 304 stainless steel.The chip shape and the maximum temperature of rake face were compared under dry cutting and external chip breaker assisted cutting conditions.The order of influence weight of each parameter and the optimal combination of cutting parameters were determined by range analysis.The simulation results show that the frequency of chip breaking is greatly increased and the maximum temperature of rake face is reduced by at least 3.25% ～ 17.6%.Finally,the single variable method is used to discuss the influence of different cutting parameters on chip macro morphology,rake face temperature,machined surface roughness and tool wear.The experimental results show that the chip breaking frequency increases with the increase of chip breaker speed.In addition,the chip length is significantly reduced,and the cutting heat,machined surface roughness and tool wear are improved in varying degrees when the external chip breaker is used. |
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