| High-speed steel tap is commonly used in the internal thread processing,As tapping is in a semi-closed or enclosed narrow space,the tap is often chipping or even broken under harsh working conditions.With the extensive use of new material in the field of aerospace and automotive in recent years,the problems such as low tap cutting efficiency and low life expectancy are increasing,which is caused by unreasonable cutting parameters and cutting environment leading to larger tapping torque,higher cutting temperature,etc.Therefore,studying the reliability of the tap life has a very important significant during the automated processing.With the continuous development of cutting simulation technology,the finite element method is used to simulate the tapping process,which can not only obtain more comprehensive cutting information,but also can reduce the test cost to obtain more accurate test results.In this paper,the tapping process was researched by the combination of taper cutting simulation and experiment to optimize the cutting parameters,and the cutting performance and tool durability information of the tapes were obtained by threading two kinds of hard materials.This paper is supported by national natural science foundation of China(51275333).Taking M8 tap to process 316 L austenitic stainless steel and H13 hot-work die steel.The parametric model of the common used tap was established by using the 3D modeling software.The tapping process was simulated by the software AdvantEdge.At the same time,the relationship between tap life and tapping torque was obtained by means of tap torque test and cutting test.The cutting parameters of the tapping process were further optimized by analyzing the different evaluation indexes in the process of tap processing.The main contents of this paper are as follows:(1)Parametric modeling of taps.Through the analysis of the structural characteristics of different taps,the mathematical models of the standard taps were established.The parametric models of common straight taps,spiral taps and screw taps were established in Pro/E software.(2)Physical model establishment.The 3D cutting model of tappingsimulation was established in AdvantEdge software.The definition of tool,workpiece and cutting parameters in the simulation process was completed.When the straight taps,spiral taps and screw taps were used to thread 316 L stainless steel,the maximum torque,the maximum axial force and the temperature distribution of the tool were analyzed and compared.Consequently,the optimum technological parameters were obtained.(3)Experimental study on tool wear and tapping torque.The tangential torque and life test of the two materials containing 316 L austenitic stainless steel and H13 hot work die steel were carried out by using straight taps,spiral taps and screw taps.The reliability of the cutting model was verified by the cutting torque measurement.The variation of wear amount of the tap under different cutting parameters was obtained,as well as the change of the torque value in the whole life cycle,which can provide data support for pre-judgment and on-line monitoring of tap wear.(4)Tap durability and wear curve drawing.Through the tapping experiment under different cutting parameters,the wear of the tap flank face was measured and compared by tool microscope.The variation rule of the flank wear was studied,and the wear curve was drawn and the empirical formula of the durability of the tap was solved.By optimizing the cutting parameters during threading the H13 hot work die steel hole,the life of the tap was improved and the productivity was increased. |
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