Papers by Author: Zhen Jia Li

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Authors: Er Liang Liu, Rong Di Han, Guang Yu Tan, Zhen Jia Li
Abstract: As machining technology develops toward the unmanned and automated system, the prediction of chip breaking is considered increasingly important, especially in continuous machining such as in cutting aluminum alloys. In this paper, chip breakers with different parameters are designed to produce chips that can be evacuated easily and reliably from the working zone. The formulation of chip up-curl radius is constructed through analyzing the chips subject to chip breaker. The predictive model of chip breaking is developed based on chip breaking conditions. Chip breaking strain is obtained by using backward-deducing method and cutting experiments. In order to verify the model, PCD tools with chip breakers are used to cut LY12, chip breaking areas are compared with those obtained from the predictive model. Results show the chip breaking predictive model is reasonable.
Authors: Zhen Jia Li, Guang Yu Tan, L.J. Wu, L.F. Lin, Gui Jie Liu, Yi Ming Rong
Authors: Zhen Jia Li, Yao Nan Cheng, Guang Yu Tan, S.Y. Ning, Z.G. Wang
Abstract: Based on the milling force testing system, we have experimented with the waved-edge milling insert and the great milling insert developed by Harbin University of Science and Technology, the American Metal milling insert, the ISCAR hackle milling insert and the flat milling insert, and then compare the insert milling capability of various grooves milling inserts. We have discussed the dynamic milling force under the incontinuous cutting condition, especially the characteristic of time and frequency. Based on the power spectrum analysis of the five types of milling inserts, we have found that the insert whose groove is formed from the curve or curly plane of the period function has an advantage on minishing the milling force and resisting to vibration. The right insert geometry parameters have great effect on improving the cutting capability. By the power spectrum analysis, we found that the complex 3-D grooves milling insert is superior to the flat milling insert on minishing milling force and vibration. The analysis result proves that using power spectrum analysis in groove optimization is viable.
Authors: Yao Nan Cheng, Zhen Jia Li, Yong Gang Zhao, Wei Jun Sun
Abstract: Based on the theoretic analysis and experiments on milling the carbon structural 45 steel with the flat rake milling insert and the waved-edge milling insert with complex 3D grooves which is developed by HarBin University of Science and Technology, we have studied on the impact disrepair mathematic model and groove optimization. On the basis of the milling force mathematic model and force density function of the waved-edge milling insert with complex 3D grooves the author built, we have the finite element analysis and blurry synthetical judgement of the 3D stress field, and forecast that the anti-impact disrepair capability of the waved-edge milling insert is choiceness. We find out the difference of the impact disrepair invalidation types between different grooves milling inserts by the experiments. Based on the plentiful and systemic impact disrepair experiments, as the emphasis in this paper, we build the impact disrepair life cumulating distribution function mathematic model by the mathematics statistic method and have contrast analysis of the impact disrepair average lives between the two types of milling inserts, and prove that the anti-impact disrepair capability of the waved-edge milling insert is choiceness. All these studies provide the theoretic and experimental basis for solving the cutter disrepair which is the key problem in the automatization production and groove optimization.
Authors: Yu Quan Chen, Zhen Jia Li, Q.B. Huang, Y. Ma, D.Y. Yang
Abstract: The chip-breaking groove of a blade is one of the main factors influencing chip control. In this paper, we report the use of a virtual reality technique to optimize the shape of the groove on a blade according to the status of chip formation and breakage. First, by using the software, World Tool Kid, the virtual cutting systems were developed to determine the linkages between the moving parts in the machine tool and display the virtual course of chip formation and breakage. And then, the virtual reality of optimizing the shape of the turning blade groove was carried out, that is, during calculation of loci in dimensional movement and solving mathematical model of the chip breakage, by inputting the groove’s parameters and cutting conditions of the blade, and simulating the track in dimensional movement of a chip and the restricting relations between the chip and each barrier, the intersecting coordinates in dimensional points of chips and the breaking manner could be solved. For improper chip-breaking manner, by modifying the model parameters, the blade groove was recalculated until the chips could be broken with ease. Based on the shapes of chips, the shape of the blades’ groove can be optimized to get optimal shape.
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