Study On The Structure Optimization And Chip Deformation Of A New Type Of Self-locking Returnable Bit

At present,drilling is the most widely used method of machining holes.The twist drill,which is frequently usedin drilling,is still the main machining method in most domestic and foreign enterprises.However,the single and low efficiency of traditional twist drilling has restricted the rapid development of drilling.Self-locking interchangeable bit is a kind of bit which is made of ordinary alloy steel and has good abrasion resistance and cutting performance.what’s more,The tool head and the tool rod are connected by self-locking connection mode,and one tool rod can correspond to several different sizes of the tool head,which can save the production cost of the tool under the condition of ensuring its interchangeability and processing quality.The bit’s machining efficiency has been greatly improved by the innovation of its structure and cutting edge materials.However,this new type of drill also has many problems in high-speed drilling.For example,chip removal is not smooth,and the bit temperature is too high,leading to sudden changes in the axial force in the processing,bit breaking,etc.,For example,chip removal is not smooth,and the bit temperature is too high,leading to sudden changes in the axial force in the processing and bit breaking,etc.it is necessary to carry out relevant research on the cutting formation,deformation rules and cutting performance of the self-locking convertible head bit in the drilling process,and then carry out structural optimization to improve the machining performance of the bit.In order to optimize the bit structure,this paper first analyzes the tool head structure of the self-locking convertible bit,the force on the tool head during drilling,and the formation and classification of drilling cuttings.Onthis basis,the drilling model of self-locking returnable bit is established by exploring the chip separation criterion and the principle of cutting heat in the process of drilling.The optimization parameter table of bit structure was designed,and the orthogonal test scheme was designed for the machining of 316 stainless steel materials with poor cutting performance.Thefinite element simulation software AdvantEdge FEM was used to establish the finite element analysis model of self-locking convertible bit.The variation rules of axial force,temperature and mises stress of the drill bit,the formation of chip and the change of the length of the comb segment were analyzed.The influence degree and rule of different structural parameters on the above simulation results are obtained through range analysis method,and the optimal structural parameters of the drill are obtained through comprehensive analysis and research.The drill bits before and after optimization were simulated under different drilling conditions to compare the drilling performance before and after optimization.The single factor method is used to analyze the influence of drilling parameters on the length of the comb section,cutting force and temperature in the process of drilling.In order to verify the feasibility and correctness of using AdvantEdge FEM finite element simulation software to simulate the new type of drill bit,drilling experiments were carried out in the machining center under the same processing conditions as the simulation.By collecting the drilling force in the drilling process and measuring the length of the comb segment of the chip generated in the drilling process,the experiment and simulation results are compared and analyzed to prove the correctness of the simulation results.Therefore,it can be concluded that the finite element simulation software can be used to carry out better simulation research on the new type of self-locking returnable bit and achieve structural optimization.This method can reduce the cost of cutting tool and experiment in the process of research and development,and provide an effective method for the design of new products.