Research On Cutting Force And Energy Consumption Modeling Of CNC Hobbing Process

CNC machine tools,such as CNC hobbing machine tools,are the main force in the industrial manufacturing field and play an important role in the manufacturing industry.China has a large number of CNC machine tools,with a wide distribution,huge energy consumption and low energy utilization.In order to achieve the strategic goals of green manufacturing,it is of great significance to study the energy consumption characteristics of CNC machine tools,reduce the energy consumption in the machining process,and improve their energy efficiency.However,most of the current energy consumption models of machine tools are aimed at milling,turning,grinding and other processing methods,and there is a lack of research on the energy consumption models of hobbing machine tools.Research on the optimization of hobbing machining parameters,tool wear and precision monitoring based on energy consumption models lacks theoretical basis.Therefore,in this paper,the following research is conducted on the modeling of cutting force and energy consumption of CNC hobbing machine tools:(1)Mathematical calculation model of cutting force in hobbing is established.In this paper,the hob is parametrically modeled based on the axial geometry of the hob cutting edge;then,based on the multi-body system kinematics theory and the principle of homogeneous coordinate transformation,the relative motion between the hob and the gear workpiece is analyzed,the trajectory parameter equations of the hob cutting edge are derived,and the three-dimensional geometric parameters of the undeformed chips are extracted according to the numerical calculation method.Finally,based on the chip geometry and the Kienzle-Victor mechanical model,the micro-element cutting force in hobbing machining is calculated,and the cutting force of the entire hob is obtained by superposing it on the cutting edge and the time domain to establish the cutting force calculation model.(2)The energy consumption model of hobbing machine tool based on cutting force simulation is established.The power of the whole machine is divided into standby power,auxiliary power,no-load power and cutting power.Among them,the standby and auxiliary power are regarded as fixed values,and the no-load power is regarded as the quadratic function of the hob speed and feed speed.Based on the numerical calculation theory of cutting force,a hobbing cutting power model is established.In order to verify the accuracy of the proposed model,multiple sets of rough hobbing and finishing hobbing experiments were carried out,and the proposed cutting power model was compared with the existing MRR empirical model.The results showed that the proposed model considering the hob The geometric parameters of the workpiece and various processing parameters can accurately reflect the influence of different processing parameters on the cutting power of the machine tool during the rough and fine hobbing stages.At the same time,the impact of hob speed,feed speed and cutting depth on the machine power is analyzed to provide an accurate energy consumption model for the optimization of hobbing parameters.(3)The optimization method of hobbing parameters is proposed.Combined with the main evaluation indexes in actual hobbing production,the hobbing machining efficiency function,energy consumption function,cost function and gear surface roughness function are established respectively;the optimization target is set according to the different machining stages,in the rough hobbing phase,the goal is to reduce the energy consumption of the machine tool and control the processing cost;in the fine hobbing phase,the goal is to ensure the surface quality of the gear,and optimize the parameters such as the hob rotaion speed and feed speed.By analyzing the parameters optimization surface,the optimal machining parameters at the corresponding stage are obtained,which provides a useful reference for the selection of machining parameters in the actual hobbing production.