Materials Science Forum Vols. 800-801

Abstract: Gears are widely used in engineering machinery. Mechanical analysis of the gears matters more much than motion analysis when they are used in heavy machinery or equipment. Dynamic simulation of the meshed gears is based on the theory of contact and impact concerning with the definition of the impact parameters and the model in ADAMS, so the dynamic simulation process is often complicated. In this paper, an effective dynamic simulation method of meshed gears was proposed by analyzing the physical significance of the impact parameters and the calculation method of the impact, and the force curve of the meshed gears was simulated. This result can provide basis for the design and manufacture of the gear.

Abstract: Cutting tool temperature is the main factor that directly affects tool wear and tool life. In this paper we developed temperature model of tool insert during slot milling process, constructed by a combination of cutting time model and non-cutting model. A set of experiments are designed and carried out to obtain cutting induced temperatures at different cutting speeds during slot milling of AISI H13 steel. Experiments results indicate that tool insert temperature increases first and then decreases as the cutting speed grows, and a critical cutting speed for the tool insert temperature exists during slot milling of AISI H13 steel. Some possible reasons for the drop of tool insert temperature are proposed and discussed, and they are decreased heat flux into tool insert and increased heat convection coefficient.

Abstract: This paper presents a sensitivity analysis method of temperature measuring point of the machine tool spindle based on grey system theory. The initial finite element analysis (FEA) is conducted on the spindle model to determine the temperature distribution of the spindle model and ascertain the resultant structural deformation, and eight nodes of the spindle model are selected as temperature measuring points. By means of grey system theory, temperature measuring points of machine tool spindle model are analyzed and then the effects of the different temperature measuring point on the spindle axial deformation are conducted. Finally, the validity of this sensitivity analysis method is verified by conducting the theoretical analysis and developing the linear estimate equation. The analysis results show that this sensitivity analysis method can effectively determine the thermal sensitivity of temperature measuring points, ensure the accuracy of the thermal compensation model and eliminate the coupling problems.

Abstract: The objective of this work is to measure the residual stress normal to the cut plane which has a large size using contour method. Translations and rotations are applied to the second point cloud to assure the continuity of the contour. There is still the same work on the opposing cut plane, align and combine the two contour datasets, perform the interpolation and then integrate with a finite element modelling package to apply many thousands of different boundary conditions. The finite element result shows a good continuity indicating the success of transformation means applied on the point cloud. The result gets the stress distribution normal to the cut plane. Beam forming is simulated to study the residual stress distribution of the stretch-wrap bend forming, the residual stress from contour method and forming simulation present the same trend.

Abstract: Through the analysis of the spindle ram deformation compensation during the process of large-scale machining, design a bridge type circuit which can improve the accuracy of processing after the ram’s moving out and meet the requirements of the compensation. The bridge type circuit has higher sensitivity for force and torque change, which improves the accuracy of machine tool. The mechanism greatly reduces the spindle rotation accuracy error caused by the gravity deviation, effectively improves the machining accuracy of the workpiece and guarantees the product accuracy of machine tool.

Abstract: In oblique cutting, the assumption of point contact between the tool and theworkpiece often results in the consideration of only the forces in the three principaldirections. This paper disregards these assumptions and confirms the existence ofmoments around the three principal directions through measurements of themechanical factors during a face milling operation. The cutting forces and moments atthe three directions achieved by using Kistler 9275B dynamometer in this paper, andthe development of a calculation algorithm that allows the transport of the cuttingmoments from the center of the dynamometer at the tip of the tooth is developed.Based on the mechanical actions’ theory, the power consumed during the cuttingprocess is determined. A comparative study on the power consumed during thecutting process is undertaken.

Abstract: In order to meet the demands of the high precision and high speed, the interface design of TMS320C6713 and AD7679 is widely used in data acquisition system. In this paper, the interface design of TMS320C6713 and AD7679 is introduced, including the design of the interface circuit and the software design of the interface. The configuration of every register of McBSP is also expounded, including configuration method and specific function.

Abstract: Based on the coupling phenomena between the batch drilling process quality fluctuation and monitoring signal features changes, the acoustic emission signals of batch drilling are taken as research objects to solve the quality consistency control and detection problem of the high-precision batch drilling step. The average bi-spectrum amplitude of each signal is taken as an eigenvalue for the quantitative analysis of the deviation degree from Gaussian distribution under different conditions. The calculation and analysis results show that there are organic connections between the bi-spectrum feature of monitoring signals and drilling step quality, and the consistency quality testing of batch drilling step is realized by bi-spectrum features.

Abstract: Most large covering parts mold use panel board type joining together of hardened steel. The vibration and the milling force is more bigger when milling process the spell near joint. They affect spell near joint processing quality. Analyze of the dynamic milling force, vibration surface morphology change of the sensitivity of the joining together with the cross-correlation function for analyzing the sensitivity of the dynamic milling force of mold spell near joint surface morphology. Experimental study shows that the dynamic milling force and the surface morphology characteristic curve cross-correlation function absolute value can reach 0.952 when the tool path and splice joints into 90°.And the cross-correlation function absolute value of milling force and the surface morphology characteristic is larger than vibration signal one. When the tool path and the joint Angle is small, the milling force influence on the surface morphology is lesser, so process should try to choose the smaller Angle seam.

Abstract: The impeller has many characteristics, such as having thin wall, low rigidity, the quality of time-varying and it easy to produce deformation and vibration in process. In order to predict the flutter during processing, milling system dynamics model is established first, and then research three-dimensional flutter stability lobes of milling system by the fully discrete method. Finally analyzes the impeller machining allowance change on the influence of the flutter stability lobes and the milling parameters on the stability of the milling system dynamics.