Papers by Author: Chang Chun Liu

Abstract: 89 Au geochemical anomalies are delineated by using 1/200000 regional geochemical exploration data. By researching regional geochemical characteristics and the relationship with the geological background, the author points out that: the main factors causing high background of Au geochemical anomalies are Gaixian and Dashiqiao formation of Liaohe group, intrusions of Mesozoic intermediate-acid intrusive rocks. The elements combination types of typical anomalies are determined by using factorial analysis,cluster analysis and other mathematical methods with the combination of elements association in typical anomalies:the composite anomaly of Baiyun gold deposits is Au-As-Sb, Maoling gold deposit is Au-As-Bi-Mo, Wulong gold deposits is Au-As-Bi-W, Xiaotongjiapuzi gold deposit is Au-As-Bi-Mo-Sb. By using multivariate statistical analysis method,62 ore-caused anomaly are preferred in 89 Au geochemical anomalies delineated. On this basis, the 62 anomalies are divided into 4 kinds of anomaly types reference to elements combination types of typical anomalies,the classification results of ore-caused anomalies are: 4 geochemical anomalies of Baiyun type,36 geochemical anomalies of Maoling type,11 geochemical anomalies of Wulong type, 11 geochemical anomalies of Xiaotongjapuzi type. According to the results, the prospecting direction is provided for the future of gold exploration.

Abstract: Modular design is an effective design concept and method that adapts to fierce market competition and versatile customer requirement. Solving the key questions in applying modular design method is the important research topic of modern CAD technology. This paper studies the evaluation question of module combination program, and puts forward the evaluation model for CNC machine tool product. Analytic hierarchy process is used as the evaluation algorithm of combination program. The actual evaluation is carried out to verify the model and algorithm.

Abstract: The main heat source of the spindle system of CNC machine tool has been analyzed. The friction heat of the motor as well as the bearing has been calculated. This paper established the finite element model of the spindle system of a precise CNC turning center, and used ANSYS to analyze the steady temperature field of the spindle system and the thermal deformation of the spindle. Finally, this paper proposed a solution to install a cooling sleeve in front of the spindle box, which can apparently reduce the thermal error of machine spindle.

Abstract: The paper mainly studies the thermal characteristic and methods of thermal compensation of the spindle system of a precision turning center. The three-dimensional model of spindle system is constructed and meshed by ANSYS Workbench. The boundary condition and heat source of the spindle system are computed by relevant theory and the results are applied to the finite element model. By comparing results of FEM and experiment, the boundary condition is adjusted if necessary to make the analysis results be similar to experimental results. Then the temperature field is used as a load to calculate the thermal deformation. Two ways of changing boundary condition of spindle system have been analyzed to find their influence on spindle thermal deformation, which are changing air flowing speed around headstock and setting up a cooling jacket at the front surface of the headstock respectively.