Papers by Author: Wei Guo Gao

Abstract: This study has developed a model in order to show the relationship between deflection of the low-rigidity processing system such like thin-walled component and the flexible milling force. The new model takes the deflection of cutter-workpiece system into account. The cutting force is analyzed simulatively by utilizing modified Newton–Raphson iterative algorithm. The simulative results show that the total normal deflection of workpiece–cutter system is the main factor affecting the change of cutting force.

Abstract: Hydrostatic guideway is widely used in heavy and ultra-precision machine tools due to their high bearing capacity, low coefficient of friction and high capacity of precision-remaining. So it is necessary to carry on theoretical research on its dynamic characteristics. Firstly, the oil-film damping coefficient of closed hydrostatic guideway throttled by capillary is derived. Secondly, a new dynamic mathematical model, considering the oil damping effect, the extrusion effect and the volume effect, of the closed hydrostatic guideway is proposed. Thirdly, the frequency characteristics and step characteristics of it are simulated in Matlab Simulink through the transfer function. Finally, the paper investigates the influence of damping coefficient, the oil pressure, volume effect and the initial oil-film thickness on the dynamic characteristics of closed hydrostatic guideway throttled by capillary.

Abstract: The motorized spindle is a primate part of the machine tool and its thermal characteristics have great influence on the accuracy of the machine tools. The thermal errors of the spindle of a certain type of precision horizontal machining center were measured with PLC acquisition system. By multivariate linear regression method, the axial thermal error model was built. Online real-time error compensation was implemented by applying the FANUC 18i CNC system external machine coordinate system shift function. A verification method was proposed which include three steps: model validation, compensation validation and experimental machining verification. The accuracy of the model was 84.1%, 64.9% and 49.4% respectively. The quantitative analysis results showed the precision was effectively improved and the compensation method was reliable.

Abstract: The text takes Z-Axis of precision machine tool as study object, and proceed the thermal character's experiment of Z-Axis feed system in different working condition (different Cooling strategy, different Feeding speed, load or not). The data of experiment shows the higher of the feed speed, the more heat is generated. Position accuracy can be increase by apply the right load and load is nearly none business with temperature rise. Cooling strategy is nearly none business with temperature rise and may cause the discretization of position accuracy.

Abstract: This document explains the details of electric spindle thermal characteristics experiments. The temperature distribution, shaft deformation and the stress of temperature sensitive points are tested. Thermal characteristics are gathered about the different cooling strategies and different spindle speeds in the experiments results analysis. Choosing reasonable cooling strategy can use to design spindle cooling system. Thermal stress test can obtain accurate data at temperature sensitive points. The stress analysis can be used to reflect spindle deformation.

Abstract: Based on the virtual instruments technology, a data acquisition and pretreatment system for monitoring the thermal signals of the spindle of machine tool is suggested, and the temperature rise and thermal distortion signals are collected synchronously. The software of the system introduces Producer/Consumer pattern to improve data sharing and buffered communication between data collecting and data storage processes, by this means, data missing and iteration are avoided, although these two processes run at different rates. At mean time, Matlab Script interface technique is utilized to realize the hybrid programming of Matlab and LabVIEW, which makes the acquisition system possess the ability of accomplishing complex algorithm.

Abstract: In the high speed precision machine tools, the thermal deformation of spindle had an important influence in machining accuracy. The data of thermal deformation of spindle was got through measuring test rod in the experiment. However, the system error existing of test rod in running and heat imported led to the difference between the measured values and the actual values. The paper has discussed the deformation of test rod caused by centrifugal force in high speed, Non-uniform thermal field in a stable state, and gravity and the variational elastic modulus. Through analyzing those factors, the main ones and neglectable ones could be confirmed, which laid the theoretical foundation in order to eliminate the interference factors in the measurement values.

Abstract: The automatic generation of flow path is the key and most difficult task in Hydraulic Manifold Blocks (HMB) design. This paper divides the HMB layout space into grids, and sets the HMB boundaries and existing flow paths to obstacles, and the paths generated using maze algorithm are regarded as the initial population of genetic algorithm. The optimal path with the shortest path and least turnings can be obtained using genetic algorithm. The ports of flow path can be connected after the generation of technical holes based on the blind holes. The design parameters of holes, such as starting point coordinates, orientations and depths, can be obtained through a series of algorithms, and then drive the secondary development system HMBDesigner based on SolidWorks to generate three-dimensional solid model. This paper also discusses the generation method of multi-port flow path and multiple flow paths.

Abstract: The connection design of flow path is the most important task in Hydraulic Manifold Blocks (HMB) design. But the traditional method of feature design can not dynamically change the topology configuration and parameters of flow path when the design changed. This paper use a hybrid model consisting of temporary body model and B-Rep model, and represent flow path pattern using adjacency graph, adjacency matrix, weight matrix and degree array. The design parameters can be optimized by non-dominated sorting genetic algorithm (NSGA2). The topology configuration of flow path can adaptively change according to the design change.

Abstract: An analysis feature-based CAD-CAE integrated approach was proposed to solve the problems of rapidly CAE modeling for static and dynamic analysis process of machine tool. Firstly, analysis features were defined in CAD system and analysis feature library was constructed for machine tool and its structural components. Secondly, analysis feature model was constructed by attaching analysis feature to CAD model interactively. Finally, ANSYS parametric design language (APDL) file was generated automatically by mapping analysis features to APDL codes, which realized the integration of CAD system and ANSYS system. Based on application programming interface (API) of SolidWorks, a parametric CAD-CAE tool oriented to static and dynamic analysis of machine tool was developed, which realized parametric modeling and automatic analysis of machine tool and improved design efficiency and quality of machine tool.