Advanced Materials Research Vols. 314-316

Abstract: Injection CAE technology has been used very widely, but value of CAE technology in engineering application has not been fully exerted. Therefore, this article proposed the quality control mode of CAE technology control injection parts molding, and use examples expound CAE technology could playing roles in plastic parts correction, mould structure optimization and process parameters adjustment, and also proved the value of injection parts molding quality control based on CAE technology.

Abstract: In this paper, the novel measurement system for estimating the six geometric error of rotary table has been proposed. This system configuration comprising four components namely laser diode, beam splitter, position sensitive detector (PSD) and deflecting mirror. The advantage of this approach is that all six geometric error of rotary table can be evaluated by just measuring four set of points from this system configuration. To estimate the geometric errors, a linear relationship is established mathematically between measurement points and geometric errors. The line equation and plane equation along with homogeneous transformation matrix are used to define the linear relationship. The mathematical model is simulated to verify the validity of the system; the result shows the proposed system is suitable to measure the geometric errors of rotary table.

Abstract: Recently, the application of fieldbus is becoming a trend in the development of CNC system towards decentralisation, network and multi-axis linkage. It is anticipated that fieldbus will be one of the leading technologies in the area of numerical control before long. Meanwhile, embedded system has been widely used in numerical control field to solve the reliability and real-time problems. In order to give full play to the advantages of embedded systems, the MECHATROLINK-II fieldbus is introduced to solve the transmission bottleneck of servo communications and multi-axis synchronous control problems. And it is proved that the application scheme combined fieldbus and embedded system is successful and valid by a large amount of performance testings.

Abstract: It’s always an important means of measuring and improving the performance of machine tools with spindle error test and error analysis. Based on the analysis of the dynamic and thermal performance of spindle, the study is focused on how to get thermal deformation and temperature field by experimental methods. First of all, spindle error analysis methods are researched. Furthermore, developed a spindle error test and analysis system, established a set of complete structure system for spindle error test and analysis. Finally, tests are performed to demonstrate the feasibility of the error test and analysis system of the spindle, which laid foundation for the further research on the experimental analysis of machine tools.

Abstract: A multiple probes scanning system comprised of two displacement sensors and one angle sensor is studied for ultra-precise profile measurement. The least squares method is applied to reconstruct the measured profile with uncertainty estimation. The parameters that influence the uncertainty associated with the measured profile are investigated. In order to obtain the optimized uncertainty, the determination of the relative parameters has been discussed in two cases. The first one is that how to select suitable sensors when intervals between two displacement sensors are known. The second one is that how to select suitable intervals between two displacement sensors when the specifications of the sensors are known. The processes of the selection in two cases are illustrated respectively according to the actual situations of the measurement.

Abstract: Considering the impact and the vibration that add to its driving system when high-speed MU running in the complex conditions, the rotor mechanical strength problems of a traction motor in MU power transmission system are studied, in this paper. The motor operating parameters when MU operating under different states, such as the starting process, the increasing voltage constant power process, and the constant voltage constant power process, are taken as the constraint boundary conditions in different situations. Considering the asymmetry of axial constraint, the distributions of both the Von Mises stress and the contact stress in rotor under different working states are analyzed, and the strength situation of rotor is evaluated. Then, the fatigue strength of rotor in a long duration rated operating is studied, and the fatigue weak position in rotor is found. The obtained results could provide a theoretical basis for the safety operation of traction motor in high-speed MU.

Abstract: Thin-walled parts are widely used in aerospace engineering. For their complexity under loading and the higher shape precision, it’s difficult for their manufacturing on high speed machine. In order to understand manufacture process, characteristic of aviation part in high speed machining is investigated. Error sources on parts are classified and the maximum error, dynamic errors are studied on its main influence factors, such as cutting force and vibration. Finally, useful method on cutting test part is proposed, which can observe and control dynamic accuracy of aviation part and ensure effective manufacture.

Abstract: The influence of radius ratio of cutting point and cutter on cutting force and stability during end milling process is presented in this paper. To derive motion equations, a 2 DOF mechanical model of end milling considering both regenerative and self-excited effects was established. Different ratio values during three milling conditions were analyzed. Cutting forces as well as stability under different radius ratios by changing curvature radius and cutter radius were elaborated respectively. The results show that when other parameters are set fixed, cutter with relative large radius has smaller cutting force and larger stable range. Cutters with same radius will overlap on cutting force when radius ratio is large enough even under different milling conditions. The proposed analysis on cutting force and stability can be used to determine the optimal parameters, such as cutter radius and spindle speed etc. to improve the accuracy and productivity.

Abstract: Wire electrical discharge machining (Wire EDM) cutting of flexures for a rotary flexural bearing fabrication is developed. The results of FEA calculation and theoretical analysis show that one of the main factors affecting flexures’ machining is the weak torsional stiffness of the bearing cage, thus excessive deflections due to machining stress, heat generation and spark-induced vibrations may occur. To minimize flexure deflection during the machining process, a specially designed fixture is utilized. Other technical measures, including residual stress relief before and after Wire EDM cutting, reasonable cutting sequence planning, multiple-cutting (i.e., rough cut followed by several trim cuts) etc., are also adopted for cutting. Dimensional accuracy of ±5µm was obtained over the 150µm thickness for the bearing flexures, a variation of less than 3µm was achieved for the flexures of opposing sides, and surface roughness of better than Ra 0.3μm was obtained for the flexures of the entire bearing cage. These results show the validity of measures aforementioned.

Abstract: In order to decrease the radial amout of cutting depth in high speed milling,optimized arc transition has been proposed in corner milling and the circular trochoid model has been used to remove the residual. Mathematical relationship based on radial depth of cutting constrain among tool radius, trochoid radius and tool step length in circular trochoid model have been analyzed .Based on the goal to limiting the radial cutting depth, appropriate parameters have been computed for higher machining quality. To verify the effectiveness of the proposed method, a compared test has been conducted. Experiment shows that optimized tool paths cause a slight increase in machining time but obtain weaker processing vibration and superior machining precision.