Papers by Author: Jin Wei Fan

Abstract: Aiming at the limitation by the high cost of test and length cycle process of the CNC grinding machine reliability evaluation, this article adopted small sample technology which needs less data while getting higher evaluation accuracy, by using the theory of Bayes theorem and failure rate as of the random variables, the experiment data of tracking CNC grinding machine for a year is analyzed. Results indicate that results acquired by this mean are consistent with the actual; meanwhile, it shortens test cycle and reduces cost, which is a very effective way to analysis CNC grinding machine. Therefore, it’s very essential that the small sample technology research is applied in the CNC grinding machine evaluation.

Abstract: Reliability allocation influence factors of CNC grinding machine tools are mostly uncertain and the fuzzy method is one powerful tool for uncertain question. The reliability allocation influence factors were analyzed and the subsystems were divided of CNC grinding machine tools. Reliability allocation weight calculation method by fuzzy mathematics is proposed and the reliability is allocated to subsystem of CNC grinding machine tools by given condition. Fuzzy reliability allocation method considering various factors is practical, accurate and it can be used in concept design of CNC grinding machine tools.

Abstract: The paper introduces the major defects and its causes of solid rocket motor,the harm and effects of the combustion chamber defects for the stability of motor were clarified,the main methods and their advantages and disadvantages of defect detection currently used in solid rocket motor are also cited and analyzed, and it points out the developing trends about various of detection technology used in conjunction.

Abstract: Based on the collected data to carry on the analysis, found that the CNC system in the CNC grinding machine fault rate, a large part of the station, the reliability growth of CNC system is studied in the paper, CNC system parameter selecting principles of reliability growth are particularly discussed. CNC system reliability ideal growth curve is settled to CNC system reliability, Thus increasing CNC system to improve the reliability of CNC grinder machine reliability is of great significance.

Abstract: The geometric error is the important aspect of affecting the process accuracy of NC machine. In order to improve the machining accuracy, the article gives a new method to compute the cutter path by making use of the error model of MAKINO based on multi-body theory. By comparing the errors which is not divided with the errors that is divided, the study shows that dividing the errors into different regions is an effective method that can improve the accuracy of machine tools. Combing the new method and the error compensation based on multi-body theory, the error partition can be easily used in the compensation of machine tools by modifying the G code.

Abstract: According to the problems of hydraulic system of sway machine, such as commissioning and maintenance are inconvenient, impact of change direction is big, system speed is slow, production efficiency is low, etc. It used electro-hydraulic proportional control valve to improve design in hydraulic system of sway machine. Application of electro-hydraulic proportional control valve has realized automatic adjustment of the hydraulic motor speed; it is effective to solve variable speed movement of sway machine frame and no impact of changing direction smooth. Commissioning and maintenance of sway machine are more convenient, and it improves performance of sway machine.

Abstract: The focus of this paper is to find a new method analyzing the reasons of CNC machine tool precision recession. The modeling of the movement error of CNC machine tool is one of the most important problem for kinematics designing and accuracy analysis. In this dissertation, this study analyzes the six movement error parameters of guide and the model of the guide which including foundation deformation, material’s natural ageing and way rub has been established. A detailed example is given for the modeling precision recession of 3-axis CNC machine tool.

Abstract: According to the multi-body system theory and geometric topology analysis method, combining the geometric structure and working principle of thread NC grinder, made the kinematics analysis for each parts of NC grinder. And the mathematical model for geometric topology structure of grinding machine system was established; the precision machining equations of NC grinder was deduced. Furthermore, the paper used the coordinate transformation principle of homogeneous to deduce the precision processing equation of NC grinder, all of that was based on the moving relationship of the machine tool, the workpiece and the grinding wheel, and got a kind of method that it can use multiple line grinding wheel to grind small radius, small screw pitch and multiple thread. This method laid a theoretical foundation for NC grinder machine processing which used multi-line grinding wheel to grind threads, and improve the grinding efficiency and precision of multi-line grinding wheel; in addition, this method has obtained good effect in grinding thread production.

Abstract: Through analyzing the shape of screw of oil extraction progressing cavity pump, the spiral surface equation of screw was established; and from the relative motion between formed milling cutter and screw, the basic profile equation of formed milling cutter was established with the method of non-instantaneous envelope. According to the actual use of formed milling cutter, aim at the problem of wear for formed milling cutter, established profile equation of front cutting edge and constant back cutting edge, and finally to get a complete profile equation of formed milling cutter. The correctness of milling cutter profile is ensured by interference checking for profile equation of formed milling cutter. The profile equation of formed milling cutter provides a theoretical foundation for the design and manufacture, and it would have great significance to the actual production.

Abstract: A new method for extracting spectrum feature of gas flucturation of aerostatic guideway is proposed. The flatness error of workpiece surface includes much errors information, and the information contains high frequency signal and low frequency signal, for these errors information, a new identification method of turning errors of workpiece based on the wavelet transform and power spectral density analysis is proposed. According to the focal variation character of wavelet and the energy value of power spectral density analysis, the feature of gas flucturation of aerostatic guideway from the measured flatness error of workpiece is extracted and identified.