Papers by Author: Bin Jiang

Abstract: In order to mend cutting instability of ball-end milling cutter caused by the changes of cutting loads in high speed milling hardened steel, we perform the modal analysis and heat-force coupling field analysis of cutter, carry out the experiment of high speed milling hardened steel, investigate the character and effect factor of physical field distribution in high speed ball-end milling hardened steel, and propose the method about the match of diameter and overhang for depressing cutter vibration. Results indicate that the decrease in the ratio of overhang to diameter can transform the first modal shape of cutter from bending modal shape into torsion modal shape. The diameter of cutter is from 30mm to 20mm, the overhang of cutter is from 125mm to 90mm, heat-force coupling field distribution changes slightly, resonance of cutter does not occur, and efficiency in machining hardened steel can be improved effectively by higher cutting speed.

Abstract: For vibration-wear characteristics of cutter in high speed ball-end milling hardened steel, established vibration-wear model of high speed milling cutter according to the principle of friction work, researched the influence of basic frequency and multiplication frequency of cutter vibration on its wear, and analyzed the interaction between cutter vibration and wear. By means of changing cutter extended length, rotation speed and cutting depth, made the change of cutter vibration, analyzed the influence of cutter vibration on its fretting and impact wear, explored the evolution process of composite vibration wear of cutter. Results show that the interaction between fretting fatigue wear and the impact wear make for cutter vibration-wear, lead to the increase of cutting force and vibration amplitude, and further increase the interaction strength of vibration and wear.

Abstract: In order to research the influence property of pre-tightening force, centrifugal force and dynamic cutting force on cutter components, and reveal safety recession of the cutter components, this paper makes load analysis for high speed milling cutter, studies cutter deformation, joint surface crushing, ductile fracture and other damage characteristics, gets the safety recession order of cutter components by safety margin theory. By means of the grey correlation analysis for safety recession, acquires the safety recession model of cutter. The experiment results confirmed that screw component firstly occurs the safety recession, and the safety recession model has certain reliability.

Abstract: Adopted the cutting-contact model of high speed ball-end milling hardened steel surfaces, researched distribution characteristics of cutting-contact stress; by researching the influence of the distribution of this stress on cutter wear, clarified the influence theory of milling pattern and cutting parameters on initial wear of milling cutter. By using the method of climbing, conventional milling alternating and changing cutting parameters, verified the influence of milling pattern and cutting parameters on initial wear pattern. The result showed that, initial wear mechanism of high speed milling hardened steel is an interaction of multiple wear mechanisms under the effect of friction and alternating pressure stress, by using conventional milling can significantly reduce concave curvature radius of hardened steel, the contact stress of blade area and front, rear flank, inhibit crushing and wear rate of the milling cutter surfaces. Under this condition, by increasing rotation speed and reducing the feed per blade, will further increase the strength of this effect, and achieve the purpose of reducing the initial wear, inhibiting the wear rate and extending the cutters life.

Abstract: Based on the field research, we found that in the course of high-speed face milling aluminum, Cutters components prone to deformation as the role of load such as Centrifugal force, Cutting force and Preload. The deformation will directly affect the the dynamic performance of the cutter. So its necessary to reveal the dynamic response of the deformation cutter. We base on the Dynamic model and the modal analysis model, Obtained the deformation cutters dynamic simulation which the cutters deformation is come from the ANSYS. At last we got the method of identifying cutters deflection deformation by vibration signal. With the method we can effectively identifying milling distortion In the cutting process.

Abstract: This paper obtained the mechanical properties of 1Cr18Ni9Ti by the static tensile test, got the corresponding relationship between the 1Cr18Ni9Ti coefficient of linear expansion, thermal conductivity and temperature changes, and simulated the process of 1Cr18Ni9Ti cutting with the finite element simulation software, then analysised the reason why the deviation of the finite element simulation results and measured data increased with the cutting speed improved. These studies provide some important references for the finite element simulation and revealing the tool wear and breakage mechanism.

Abstract: The article is about the safety for high speed milling tools between macroscopic and mesoscale, making some analysis about the relationship between damage of cutting tools and its components and mesoscale movement, the damage of cutting tools and its components is known. With the boundary conditions of material force damage, using the material design software named MAPS to do molecular dynamics simulation, the simulation is about mesoscale state in different stress, Make sure the various mesoscale movement on stress response rate, the model of intrinsic/extrinsic about the safety for high speed milling tools on a mesoscale is established. Clear the value of intrinsic/extrinsic parameters and mesoscale movement on stress response rate. The regular pattern between damage of cutting tools and its components and mesoscale movement, which could help us to design tools, choose materials of tools and determine cutting parameters.

Abstract: Geometry constraint and physical constraint change because the structure is complex, tonnage is large, and assembly load is complex on heavy duty machine tool, assembly relation is changed for repeated assembly, then, the assembly accuracy reproducibility and assembly accuracy retentivity decline, which results in the decrease of assembly reliability. According to this problem, the interaction of geometry constraint and physical constraint is discussed in this paper, the influence factors of assembly accuracy reproducibility and assembly accuracy retentivity are respectively analyzed, the establishing, demolition and re-establishing of assembly relation effects assembly accuracy reproducibility, and evolution of assembly relation with time effects assembly accuracy retentivity, which are respectively revealed. Using margin method to evaluate assembly accuracy reliability, the criterion and evaluation method of assembly accuracy reliability is proposed, in order to provide reliable and quantitative criterion for assembly process design, and reasonably set safety margin of geometry constraint and physical constraint, form reliable assembly process, realize that the assembly accuracy is controlled and improved by assembly.

Abstract: Based on the experiment of high speed ball-end milling hardened steel, investigated the distribution characteristics of cutting force and cutting heat and wearing character of cutter, and set up analysis model of cutter physical field. Using failure criterion and safety margin of cutter, founded physical field evaluation model of high speed ball-end milling cutter. By means of physical field analysis and experiment, explored the influence of cutting parameters on cutting property during cutter wear. Results indicate that the method of safety margin and physical field evaluation model can evaluate cutting property of cutter effectively, the impact of feed per tooth on physical field and safety margin is noticeable, and high speed and small feed are helpful to improve safety margin and cutting performance of cutter.

Abstract: In order to solve the problem of machined surface damage and machining efficiency decline that caused by the decrease of effective cutting thickness in high speed ball-end milling hardened steel, using high speed cutting adiabatic shearing model, analyzed the adiabatic shearing deformation on hardened steel, and proposed the criterion of chip separating position. Analyzed the force in the transformation process from cutting to plowing, the influence of cutter deformation on cutting thickness was studied, and established the minimum cutting thickness model. Having done finite element analysis of cutter and experiment of high speed milling hardened steel, the validity of the minimum cutting thickness model was proved. The results show that cutting thickness changes from small to large, and then from large to small under the influence of cutting trajectory and tool edge radius. The deformation of cutter leads to the increase of the minimum cutting thickness, and further enhances chip thickness thinning effect. High feed can compensate cutting thickness thinning and the minimum cutting thickness model provides an effective way to restrain the damage of machined surface and cutter caused by cutter plowing.