The Process Parameters Optimization Model Of Gear High-Speed Dry Hobbing And Its Application System Development

Gear hobbing process is one of the most widely used forming process of gear teeth.The development of high-speed dry cutting technology provides a solution for realizing green,efficient and automated gear production.Since there is not any cutting oil for cooling or lubricating and different hobbing parameters produce different chip thickness,the thermal deformation errors of machine tool,the hob life and the quality of work-piece are sensitive to the process parameters.The applicable range of high-speed dry hobbing parameters and traditional hobbing parameters vary greatly,the properties of dry hobbing and application in the production line need to be comprehensive consideration when set the high-speed dry hobbing parameters.There is little research about the parameters optimization method of high-speed dry hobbing.In this context,with the support of projects as National High Technology Research and Development Program(863Program)of China(Grant No.2012AA040107)and National Natural Science Foundation of China(Grant No.51475058),the process parameters optimization model of gear high-speed dry hobbing and its application system development are studied in this paper,the specific research work are as follows:Firstly,a high-speed dry hobbing process parameter system and its basic calculation method are established based on the hobbing principle.And the calculation method of the cutting efficiency,cutting cost and gear errors are analyzed.Secondly,a hobbing parameters on-line optimization model with hobbing efficiency as objectives is established,in which the cutting speed and maximum tip chip thickness were considered as optimizing variables and cutting time,cutting cost and gear error are considered as constraints.The optimization model is solved by experiment iterative method,and the optimization efficiency is higher and higher with the accumulation of basic data.Then,the high-speed dry hob life extension technology is studied based on the highspeed dry hobbing parameters optimization model.The cutting length of single blade is used as evaluation indexes of the high-speed dry hob tool life and the corresponding calculation model is established.High-speed dry hob life experiments are carried out,and a multivariate linear regression model which solved by MATLAB is established to build the empirical formula.Based on these work,a way to optimize cutting parameters and a new hob shifting strategy are put forward to improve high speed dry hob tool life.Finally,in order to realize application of hobing process parameters optimization model in the automatic production line,a high-speed dry hobbing parameters optimization support system is developed based on SIEMENS 840 D CNC system,in which machine tool parameters,work-piece parameters,hob parameters can be defined,spindle speed,feed rate,depth of cut can be accurately calculated and the corresponding numerical control code generated automatically.The system has been applied in the production practice of a car gear automatic production line,and achieved good results.