Jiangsu Key Laboratory of Advanced Numerical Control Technology

Nanjing, China

Jiangsu Key Laboratory of Advanced Numerical Control Technology

Nanjing, China
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Gao S.,Nanjing University of Aeronautics and Astronautics | Yang C.,Nanjing University of Aeronautics and Astronautics | Yang C.,Jiangsu Key Laboratory of Advanced Numerical Control Technology | Xu J.,Nanjing University of Aeronautics and Astronautics | And 3 more authors.
International Journal of Advanced Manufacturing Technology | Year: 2017

Internal traverse grinding (ITG) has shown its great potential in precision machining of valves in fuel supply systems. When grinding such valves, long grinding wheels with small diameter are necessary. However, the poor stiffness of grinding wheels causes large deflection of wheel quill during grinding, resulting in deviation between nominal radial feed and actual radial feed, finally reducing the grinding efficiency and consistency of ground parts. In this study, an analytical model on wheel quill deflection was built. Then, a series of ITG tests were conducted to calibrate and validate the model. The results demonstrated that the model showed good accuracy. Furthermore, based on this model, an effective feeding strategy with rapid feed and over feed was proposed to improve the grinding efficiency of ITG. © 2017 Springer-Verlag London


Bian R.,Nanjing Institute of Technology | Bian R.,Jiangsu Key Laboratory of Advanced Numerical Control Technology | He N.,Nanjing University of Aeronautics and Astronautics | Ding W.,Nanjing Institute of Technology | And 3 more authors.
International Journal of Advanced Manufacturing Technology | Year: 2017

This paper investigates the performance of self-developed polycrystalline diamond (PCD) micro end mills in ductile milling of fully sintered zirconia ceramic. Experiments are conducted on a precision milling machine center. The influence of cutting parameters, including axial depth of cut (ap), feed per tooth (fz), and the PCD particle size on the achievable surface quality is studied by experimental design. Further tests are also conducted to study the tool wear during a milling process. The tool wear characteristics are observed and tool wear mechanism is discussed. The results show that average surface roughness Ra below 70 nm can be achieved on the machined samples. The factor of feed per tooth affects Ra value the most. The maximum tool tip wear VC can be used to indicate the severity of tool wear. According to the results, the PCD micro end mill with bigger particle size possesses longer tool life. The mainly tool wear mechanism of the PCD micro end mill in ductile milling ceramics is the periodic peeling off of diamond particles during the interaction between the workpiece and end mill. Zirconia ceramics can deform in a plastic way and adhere to the cutting edge in the milling process. The adhesion and spalling of zirconia would induce the peeling off of PCD particles. © 2017 Springer-Verlag London


Wei B.,Hefei University of Technology | Yuhua X.,National University of Defense Technology | Mulan W.,Jiangsu Key Laboratory of Advanced Numerical Control Technology | Hao Z.,Jiangsu Key Laboratory of Advanced Numerical Control Technology
Proceedings - 2017 32nd Youth Academic Annual Conference of Chinese Association of Automation, YAC 2017 | Year: 2017

In this paper we propose a method named spacetime stereo phase-shift for fast 3D shape measurement. It combines the advantages of the spacetime stereo approach and phase-shift approach. We first generate two different binary random patterns. In each projection cycle, four patterns including three phase-shift patterns and one binary random pattern are projected. In the two adjacent projection cycles, the two random patterns are switched alternatively, which is the main feature distinguishing the proposed approach with other approaches. As a result, we can use five image pairs for reconstruction without increasing the number of the patterns. Detailedly, we use the two image pairs of the random patterns (one of them is from the previous projection cycle) to establish the dense and subpixel-level correspondences by combining the wrapped phase maps from the three-step phase-shift method in the spacetime stereo framework. With an extra random pattern, the discrimination of the matching window can be enhanced greatly so that a simple local stereo matching method using the normalized cross correlation (NCC) can be utilized to acquire reliable matching. Experimental results show that the proposed method can improve the reconstruction results evidently. © 2017 IEEE.


Gao S.,Nanjing University of Aeronautics and Astronautics | Yang C.,Nanjing University of Aeronautics and Astronautics | Yang C.,Jiangsu Key Laboratory of Advanced Numerical Control Technology | Xu J.,Nanjing University of Aeronautics and Astronautics | And 3 more authors.
International Journal of Advanced Manufacturing Technology | Year: 2017

Due to its ability to provide more inter-grit chip space and higher grit protrusion, monolayer-brazed CBN wheel has great potentials in internal traverse grinding (ITG) of small holes of high strength and toughness materials. Before engineering application, it is necessary to study the wear behavior and wear mechanism of the brazed CBN wheels. A series of internal traverse grinding tests was conducted with a small self-manufactured monolayer-brazed CBN wheel. The radial wear, grinding ratio, and ground surface roughness was measured to evaluate the wear behavior of the brazed CBN wheel. Besides, the topographic features of the wheel surface were also observed to explore the wear mechanism. It can be concluded that the wear behavior of the brazed CBN wheel in ITG can be divided into three stages according to the grinding ratio, namely rapid wear stage, transitional wear stage, and stable wear stage. Macro-fracture, attritious wear, and large wear flat were respectively the main wear characteristics during the three wear stages. From the point of grinding ratio and ground surface roughness, the stable wear stages were the most suitable for production, followed by the transitional wear stage. © 2017 Springer-Verlag London Ltd.


Zuo J.M.,Changzhou Institute of Technology | Wang M.L.,Jiangsu Key Laboratory of Advanced Numerical Control Technology | Chen J.,Nanjing Kangni Mechanical and Electrical Co. | Wang B.S.,Jiangsu Key Laboratory of Advanced Numerical Control Technology
Applied Mechanics and Materials | Year: 2014

Control system is the key factor for performance of digital forming machine. To meet different needs, an open NC system structure is proposed based on PMAC. Selection of servo motor is analyzed, and hardware of control system is established. Software composed of multiple modules is developed with VC++, and also communication between PC and PMAC is realized. Furthermore, a method to optimize manufacturing process and interpolation path is presented according to characteristics of lost foam machining. Simulation and experiment are carried out, and the results confirm that the control system is excellent. © (2014) Trans Tech Publications, Switzerland.


Wang B.S.,Nanjing Institute of Technology | Wang B.S.,Jiangsu University | Zuo J.M.,Jiangsu University | Wang M.L.,Jiangsu Key Laboratory of Advanced Numerical Control Technology | Hou J.M.,Jiangsu Key Laboratory of Advanced Numerical Control Technology
Materials and Manufacturing Processes | Year: 2012

This article presents a method to obtain the cutting force coefficients needed to predict the milling force using a mechanistic model of the milling process. A finite element model is developed and used to simulate the oblique cutting process of cutting edge discrete element for the Al6061-T6 milling. The model reflects the effects of high temperature, large strain, and strain rate to the workpiece material. Based on the simulation results, the relationship between cutting force coefficients and chip thickness is deduced, and inverse proportion models are presented. To validate the accuracy of the model, instantaneous milling force is predicted and shown to match the real measured force with satisfactory accuracy. Based on predicted milling force, the machining processing is optimized. © 2012 Copyright Taylor and Francis Group, LLC.


Wang B.,Nanjing Institute of Technology | Hao H.,Nanjing Institute of Technology | Zuo J.,Jiangsu Key Laboratory of Advanced Numerical Control Technology | Wang M.,Jiangsu Key Laboratory of Advanced Numerical Control Technology | And 2 more authors.
Metallurgical and Mining Industry | Year: 2015

Cutting force coefficients are the key factors for efficient and accurate prediction of milling force. This paper presents a new method to calibrate the cutting force coefficients using the surface errors related to milling of thin-walled workpiece including effect of cutter runout. The surface error is separated into nominal surface error and perturbation component due to runout. By analyzing forming of surface error, cutter deformation and deflection of thin-walled workpiece, the result that cutter runout has no effect on the average surface error is achieved. Relationship between nominal surface error and cutting force coefficients is constructed, and also an approach for extraction of nominal surface error from measured surface error is proposed. Then, the cutting force coefficients are estimated conveniently. Milling tests are carried out to verify the proposed method. A good agreement between predicted results and experimental results is achieved, which shows that the method is efficient.


Zhu W.B.,North Carolina State University | Zhu X.C.,Nanjing Institute of Technology | Zhu X.C.,Jiangsu Key Laboratory of Advanced Numerical Control Technology | Wang M.L.,Jiangsu Key Laboratory of Advanced Numerical Control Technology | Ding W.Z.,Jiangsu Key Laboratory of Advanced Numerical Control Technology
Applied Mechanics and Materials | Year: 2014

The ability of acquiring and processing information in manufacturing influences agile of manufacturing system. According to the idea that networked field information processing is realized based on intelligent nodes of field-bus technology, distributed intelligent field information processing flow is researched to synthesize multiple functions such as information gathering, information processing, warning system and field control. The method of information represented and collected was put forward. The multilayer data fusion model of distributed intelligent field information processing is built. Then the distributed LonWorks fieldbus monitoring model (DLFMM) based on LonWorks fieldbus technology is established. A monitoring system of a rail vehicle automatic door factory is shown as an example to illustrate design strategy of monitoring system based on DLFMM. This monitoring system shows that the model of distributed intelligent field information processing, DLFMM and the extraction and representation of information flow discussed in this paper are reasonable and applicable. © (2014) Trans Tech Publications, Switzerland.


Wang B.,Nanjing Institute of Technology | Hao H.,Nanjing Institute of Technology | Wang M.,Jiangsu Key Laboratory of Advanced Numerical Control Technology | Hou J.,Jiangsu Key Laboratory of Advanced Numerical Control Technology | Feng Y.,Jiangsu Key Laboratory of Advanced Numerical Control Technology
International Journal of Advanced Manufacturing Technology | Year: 2013

Cutting force coefficients are the key factors for efficient and accurate prediction of instantaneous milling force. To calibrate the coefficients, this paper presents an instantaneous milling force model including runout and cutter deformation. Also, forming of surface error is analyzed, and a surface error model considering runout is proposed. Using surface errors of two experiments completed with the same cutting conditions but different axial depth only, cutter deformation is obtained. Then, a new approach for the determination of instantaneous cutting force coefficients is provided. The method can eliminate influences of the other factors except cutter deformation and runout. A series of experiments are designed, and the results are used to identify the parameters. With the evaluated coefficients and runout parameters, the instantaneous milling force and surface error are predicted. A good agreement between predicted results and experimental results is achieved, which shows that the method is efficient, and effect of runout on surface error is not negligible. © 2013 Springer-Verlag London.


Dong H.,Nanjing University of Aeronautics and Astronautics | Yang C.,Nanjing University of Aeronautics and Astronautics | Yang C.,Jiangsu Key Laboratory of Advanced Numerical Control Technology | Gao S.,Nanjing University of Aeronautics and Astronautics | And 3 more authors.
Jingangshi yu Moliao Moju Gongcheng/Diamond and Abrasives Engineering | Year: 2016

For typical difficult-to-machine materials of nickel-base superalloy GH4169, honing experiments are carried out to study the hole surface roughness and cylindricity. Results show that the surface roughness decreases gradually and tends to be stable as honing continues when honing GH4169 using metal bonded CBN oilstone. The best surface roughness is Ra 0.7 μm when using the grit size 100 μm oilstone, Ra 0.3 μm using 34 μm oilstone and Ra 0.1 μm using 8 μm oilstone. Based on the results, two prediction models, namely the minimum bottom hole machining allowance prediction model and the maximum allowable deviation of cylindricity prediction model, are established and verified by relevant experiments. It turns out that the errors of the models are less than 10%. © 2016, Diamond & Abrasives Engineering Editorial Office. All right reserved.

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