Shen G.,Jilin University |
Li H.,Jilin University |
Li H.,Xuzhou Heavy Machinery Co. |
Zhang Y.,Jilin University |
And 3 more authors.
Chongqing Daxue Xuebao/Journal of Chongqing University | Year: 2013
The reliability level of tool magazine is an important indicator to show how advanced a horizontal machining center is. To more effectively promote the reliability level of tool magazine, a new method combining importance and structure optimization is introduced. Taking tool magazine of a horizontal machinging as object, the fault tree of a tool magazine is established based on 35 failure data obtained from a horizontal machining center. Important levels of elementary events are calculated by fault tree analysis, and the order of importance is determined based on importance values. An improved design of structural reliability for elementary events with great importance is made according to failure principles and tool changing process. The feasibility of the improved design is verified by the designer of the tool magazine.
Yan P.,Xi'an Jiaotong University |
Zhao L.-P.,Xi'an Jiaotong University |
Wang G.-Q.,Dalian Machine Tool Group Corporation |
Nie Q.-F.,Xi'an Jiaotong University
Jisuanji Jicheng Zhizao Xitong/Computer Integrated Manufacturing Systems, CIMS | Year: 2010
Aiming at product configuration problem oriented to customer requirements analysis, a mapping method of customer requirements by integrating Quality Function Deployment (QFD) and rule-based reasoning method was put forward. The mapping relationships between customer requirements parameters and module attribute parameters were established based on House of Quality (HOQ) of QFD, and rule-based reasoning was used to determine the target values of technical requirements and select the module instances. Then, the product modular configuration scheme set was obtained to meet customer requirements. Finally, the proposed method was verified by case analysis.
Bin Z.,Xi'an Jiaotong University |
Qingfeng M.,Xi'an Jiaotong University |
Nan W.,Xi'an Jiaotong University |
Zhi L.,Dalian Machine Tool Group Corporation
Journal of Physics: Conference Series | Year: 2011
The energy consumption of wireless sensor networks (WSNs) is always an important problem in the application of wireless sensor networks. This paper proposes a data compression algorithm to reduce amount of data and energy consumption during the data transmission process in the on-line WSNs-based bearing monitoring system. The proposed compression algorithm is based on lifting wavelets, Zerotree coding and Hoffman coding. Among of that, 5/3 lifting wavelets is used for dividing data into different frequency bands to extract signal characteristics. Zerotree coding is applied to calculate the dynamic thresholds to retain the attribute data. The attribute data are then encoded by Hoffman coding to further enhance the compression ratio. In order to validate the algorithm, simulation is carried out by using Matlab. The result of simulation shows that the proposed algorithm is very suitable for the compression of bearing monitoring data. The algorithm has been successfully used in online WSNs-based bearing monitoring system, in which TI DSP TMS320F2812 is used to realize the algorithm. © 2011 Published under licence by IOP Publishing Ltd.
Sun Y.,Dalian University of Technology |
Wang D.,Dalian University of Technology |
Dong H.,Dalian University of Technology |
Xue R.,Dalian Machine Tool Group Co. |
Yu S.,Ryerson University
Chinese Journal of Mechanical Engineering (English Edition) | Year: 2014
The current research of machine center accuracy in workspace mainly focuses on the poor geometric error subjected to thermal and gravity load while in operation, however, there are little researches focusing on the effect of machine center elastic deformations on workspace volume. Therefore, a method called pre-deformation for assembly performance is presented. This method is technically based on the characteristics of machine tool assembly and collaborative computer-aided engineering (CAE) analysis. The research goal is to enhance assembly performance, including straightness, positioning, and angular errors, to realize the precision of the machine tool design. A vertical machine center is taken as an example to illustrate the proposed method. The concept of travel error is defined to obtain the law of the guide surface. The machine center assembly performance is analyzed under cold condition and thermal balance condition to establish the function of pre-deformation. Then, the guide surface in normal direction is processed with the pre-deformation function, and the machine tool assembly performance is measured using a laser interferometer. The measuring results show that the straightness deviation of the Z component in the Y-direction is 158.9% of the allowable value primarily because of the gravity of the spindle head, and the straightness of the X and Y components is minimal. When the machine tool is processed in pre-deformation, the straightness of the Z axis moving component is reduced to 91.2%. This research proposes a pre-deformation machine center assembly method which has sufficient capacity to improving assembly accuracy of machine centers. © Chinese Mechanical Engineering Society and Springer-Verlag Berlin Heidelberg 2014.
Cong M.,Dalian University of Technology |
Liu D.,Dalian University of Technology |
Cui D.-M.,Dalian University of Technology |
Meng G.-X.,Dalian Machine Tool Group Corporation |
Dong X.-S.,Dalian Machine Tool Group Corporation
Dalian Ligong Daxue Xuebao/Journal of Dalian University of Technology | Year: 2011
A new approach to building the mathematical model of large-sized CNC lathe bed with static and dynamic fuzzy constraints was presented by combining the fuzzy theory with finite element method. Based on sensitive analysis of the bed structure, fuzzy logic inference was applied to constructing the fuzzy set of sensitivity to determine the optimal group of fuzzy design variables. An improved optimal vector level cut set method was induced to distinguish the effects of fuzzy constraints, so the optimal solution would not be lost. The analytical results show that using fuzzy finite element method, a more reasonable solution than one by using the conventional optimum method can be obtained. This method can reflect the fuzziness of engineering problem, and it also can do beneficial exploration for optimization design of complex large-sized structure.
Zhou Z.,Dalian Machine Tool Group Corporation |
Song J.,Dalian University of Technology |
Cong M.,Dalian University of Technology
Advanced Materials Research | Year: 2012
To meet the need of high precision and speed, the movable parts of a high speed machining center should be as light as possible with high stiffness, which can be realized effectively via structure topology optimization. In this paper, structure topology optimization of the spindle box of a type of machining center was carried out based on the software of OptiStruct of HyperWorks. In the course of design, a stiffness criterion was put forward to deal with the uncertainty of cutting load on a machining center. And based on the criterion, the load boundary condition of the spindle box model was defined. And a clear structure was finaly obtained in the postprocessor of OptiStruct.
Cong M.,Dalian University of Technology |
Wang H.C.,Dalian University of Technology |
Li S.S.,Dalian University of Technology |
Wang D.S.,Dalian Machine Tool Group Corporation
Applied Mechanics and Materials | Year: 2013
In this article, the Lathe Bed of DL20-MST CNC machine tool is taken as the research object. The response surface method and optimization design of goal-driven are introduced. Combining the two methods, the size optimization design method of the Lathe Bed of NC machine tool is put forward based on the ANSYS. The design dimensions which play an important role in the static and dynamic performance of Bed are found through sensitivity analysis. And then, the goal-driven optimization design of the Lathe Bed is carried out based on the response surface method, searching for the optimal dimensions of Lathe Bed, realizing the lightweight design of the Lathe Bed of NC machine tool. In addition, the improvement on the performance of Lathe Bed after optimization is analyzed. The ideas and methods used in this paper offer a good reference for the design and production of the key parts of other similar machine tools, and have a great engineering application value. © (2013) Trans Tech Publications, Switzerland.