Papers by Author: Xian Li Liu

Abstract: Precision Hard Cutting process is easy to generate periodic saw chip. So it is significant to research characteristics of chip formation. Based on DEFORM software platform and FEM, the behavior of adiabatic shear in cutting deformation zone is simulated, simulation results show that the formation of saw chip is due to plastic instability occurred in the shear plane resulting concentrated shear slip; chip cross-sectional microscopic analysis is used to analyzed chip morphology, microscopic observation results show that with the increase of cutting parameters, the degree of segmentation increases and the cutting speed is the most significant factor. The boundary is determined between the continuous chip and saw chip, with increase of workpiece hardness, critical cutting parameters of generating saw chip reduce. The results can provide a reasonable amount of reference data for choosing cutting parameters of high-speed hard cutting.

Abstract: The chatter between tool and workpiece has become a problem that urgently need to be solved in modern manufacturing system development.This paper analyzes the main factors in affecting the flutter when to turn ring groove of inner hole for large stainless steel thin-walled pieces. take normal direction of workpiece cutting surface as modeling direction, consider processing status of the large cylinder workpiece with large diameter, large height, small wall thickness and vertical large overhang. Based on vibration theory, establish a vibration dynamic mathematical model for large thin-walled parts in turning process, investigate the flutter in processing, provide a useful reference for solving the vibration problem of large cylinder parts in processing.

Abstract: To improve the processing efficiency and Surface qualityof impeller. Impeller processing difficulties as a major object of study were researched by this paper. Using UG7.5 impeller processing module, Based on the impeller feature division idea and to optimize the impeller machining path.Finally, Through it carried out the tool path generation and simulation and verify the feasibility of processing. To effectively enhance programming efficiency and processing quality.

Abstract: . Large automobile cover die with complex characteristics and high hardness after quenching is mainly applied hard milling. In processing, large tool vibration, short cutting-life and much time-consuming increase the die manufacturing cost. In this paper, the relationships of cutting speed with achining efficiency and thickness with tool life are considered in the optimization method. The optimization method based on VERICUT uses the relationships to improve machining efficiency and tool life, thus reduce the large automobile cover die processing costs. The simulation and the optimization laid the foundation for the follow-up physical simulation and experiment.

Abstract: As heavy cutting is widely used in the energy field of China, it has important significance to study the cutting mechanism. Based on this reason, this paper has overcome limitations of the traditional cutting method, established a reasonable boundary conditions by using finite element analysis software Third Wave, and used accurate material constitutive model to build finite element simulation model on heavy cutting process, The effect of the cutting parameters to the cutting process is studied by simulation results, and chip formation is analyzed. The results provide a theoretical basis for the optimization on heavy cutting conditions.

Abstract: In NC machining large moulds, second mold will install deviated orientation problem. Based on image technology, after the second for installation of workpiece, collected clip in the concrete pins on measuring and calculating the image processing, analysis, and finally got the localization generated during installation and adjustment, the deviation of the machine to eliminate biases. In image processing of PSCP thinning algorithm, based on the characteristics of image edge detection were analyzed, the extraction and processing, improve the machining accuracy and efficiency. This method can also be used in small parts processing detection, etc.

Abstract: High-speed precision hard cutting always causes vibratory motion, which has great influence on production efficiency, machining quality, machining environment, operating cost, machine tool life and cutting tool life. The dynamic model is established that is about flutter system of external circular finish turning recycled hardened steel; the limit of hard cutting system stability is analyzed, and the limit of hard cutting system stability can be predicted with numerical simulation in Matlab; with the larger corner radius change and the more the hardness of workpieces increases, the more the maximal stabile cutting width reduces. Hardened steel GCr15 is cut in different cutting condition with PCBN tools, the result obtained by the method coincides with the actual result. So, with selecting cutting parameters through the method, it is ensured that the cutting proceeds in the stable region throughout.

Abstract: Both the heavy cutting process and the importance of the chip control are discussed. Through analyzing the characteristics of the rough machining of the hydrogenated cylindrical shell, both the structure and the material of the turning tool for rough machining are designed. To test and verify the feasibility study on them, the contrast experiment between the new-type turning tool and the reference substance in cutting the 2.25Cr-1Mo-0.25V steel which is the material of hydrogenated cylindrical shell is made, then the service life and the chip-breaking performance of the tool are compared. Finally, the technical reference to design the new-type turning tools is summarized.

Abstract: Modeling and simulation of ball-end milling cutter has an important means in studying milling process characteristics. Most scholars ignore practicability analysis before modeling, according to this, modeling and simulation of optimization path is proposed based on cutting path optimization experiment in this paper, which simplifies modeling and simulation and makes model development and practical application have more pertinence and practicality.

Abstract: Because the tube festivals surface is not round, uneven, so the cutting tool is under impact unceasingly in cutting process. Cutting tool is extremely easy to have fatigue failure, therefore it is very necessary to use finite element numerical analysis software ANSYS to carry on numerical simulation analysis for heavy lathe tool intensity static. The force of cutting tool and distributed rule of definite cutting tool internal stress strain could be precisely got by using FEM, thus the analysis results could improve cutting tool stress condition and the structural design provides the theory basis