Papers by Author: Gui Bing Pang

Abstract: According to the analysis of the bent tube's characteristics and the problems existing in the testing fixture design, the design method of testing fixture for bent tube based on UG are presented. The detail steps of the design and the use method for the testing fixture is described by a designing example. With this method, the designer can achieve new testing fixture just through partly modifying the parameters of the existing designing example owing to UG software possessing the feature of parameterized modeling. The design process of testing fixture design becomes easier, more reliable and efficient.

Abstract: Electrochemical finishing with pulsed current (ECFP) is introduced in this paper. The main process parameters, such as electric parameter and inter-electrode gap, etc., were investigated. The results show that the ECFP is an effective finishing method for improving the machining quality as the result of the machining mechanism. The related experimental results show that the obtained surface quality and dimensional accuracy are improved significantly as the result of the application of the pulsed current. Moreover, machining quality is increased with shorter pulses.

Abstract: In this paper the characteristics of pulse electrochemical deburring (PECD) is analyzed through a developed mathematical model and main influencing factors such as applied voltage, pulse duty factor, deburring time, initial burr height and initial interelectrode gap on burr height have been analyzed. The paper also highlights the scheme of the developed PECD system designed to operate within the parametric limits. The calculated results obtained from the mathematical model are found to be approximately consistent with the experimental results. The results show that initial burr height h₀=0.057mm is removed, and the fillet radius R=0.248mm is obtained. The present paper through various parametric studies will act as a guideline for the operation of a PECD system.

Abstract: Gears’ accuracy has important influences on its working performance and life. Electrochemical mechanical finishing (ECMF) was applied to finish cylindrical gears. The influence of the generative type of ECMF was studied theoretically and experimentally on the shape of gear teeth, and on the dimensional accuracy between teeth, and that in the tooth thickness direction. The results indicate that the generative type of ECMF can improve the accuracy between teeth, as well, the dimensional accuracy of gear tooth and that in the thickness direction may be also improved.

Abstract: In the press forming of some rectangular workpieces such as floor tiles and automobile panel, in order to make the hydraulic pressure distribute on the workpiece evenly and reduce the dimension of the cylinder, the rectangular cross-section piston has comparative advantages to the ordinary rounded cylinder. Finite Element Analysis (FEA) method is used to simulate the stress and deformation distribution of the rectangular cylinder. It is found that the largest deformation region is on the central of cylinder, the corner of the cylinder has the maximum stress. To decrease the deformation and stress, the convex cross-section shape and rounding corner is used, which effectively reduces the deformation and stress. By analyzing the influence of stress and strain under the conditions of different radius of the corner and different convexity of the cylinder wall, structure of the cylinder is optimized.

Abstract: In this paper, surface topography characteristics of electrochemical mechanical finishing (ECMF) for steel was investigated. The scanning electron microscopy (SEM) was used to observe the surface topography. And the microcosmic geometry parameters were measured by Talysurf SLI2000. Compared with original surface, the surface topography characteristics of the workpiece machined by ECMF have been analyzed with altitude density function (ADF) and auto correlation function (ACF). The results show that there exist periodicity component in surface profile before and after finishing. The auto correlation curves of ECMF surface have a smaller average period compared with grinding surface. The low-frequency component and the mean ripple peak distance of original surface profile are obviously decreased. Furthermore, the ripples and peak density are increased, and the surface roughness Ra is decreased from 0.231μm to 0.023μm. The results indicate that surface quality, material ratio of the profile and wear resistance machined by ECMF are improved obviously.

Abstract: The drilling burr is taken as the research object. A mathematical model of electrochemical deburring (ECD) is established and the effects of main influencing factors, such as inter-electrode gap, applied voltage and deburring time, on burr height have been analyzed. The results show that the deburring time increases with the increase of initial burr height, inter-electrode gap, with the decrease of volume of electrochemical equivalent of the workpiece material, conductivity of electrolyte and applied voltage. The deburring time for various burr heights can be predicted by the mathematical model. The calculated results obtained from the mathematical model are approximately consistent with the experimental results. The results show that initial burr height h0=0.722mm is removed, and the fillet radius R=0.211mm is obtained.

Abstract: Gears’ surface quality and modification characteristic have an important influence on its working performance. Pulse Electrochemical Finishing (PECF) could get excellent surface topography. In this project, PECF with a scanning cathode is used to finishing the cylinder gear. Tooth profile modification is realized by PECF with an uneven interelectrode gap distribution along the tooth profile and tooth lead modification is realized by PECF with a variable moving velocity of the cathode. The experimental results show that the tooth surface roughness could be decreased from Ra 3.9μm to Ra 0.35μm, which means that the PECF process possesses the finishing ability for the raw surface tooth, and the difference of material removal of PECF with an uneven interelectrode gap distribution could be 46μm and the material removal could be controlled by regulating the moving velocity of the cathode, which means tooth profile and lead modification could be realized by PECF.

Abstract: The service properties and lives of mechanical parts and components are closely related to their surface quality and precision, and many of the frictional surfaces are required to be finished thereby improving the surface quality and precision. In electrochemical mechanical finishing (ECMF) processes, the surfaces of metal parts are removed through the electrochemical anodic dissolution to obtain the desirable dimensions and surface finish. ECMF is characterized by the independence of the hardness of workpiece and little wear in tools. As a result, it has received more and more attention in the research area of polishing and finishing for mechanical parts. This article reviews the practical works in ECMF technologies from the aspects of surface quality and precision characteristics. Not only excellent surface quality but also high precision dimensions of parts can be obtained with ECMF. It has wide applications in machining precision mechanical parts and components.

Abstract: The surface quality of components has the important influence on the components’ operational performance, characteristic of the geometry topography and statistical Characteristic is the important aspect of the surface quality. This study takes the arithmetic mean deviation of the assessed profile (Ra) to reflect the altitude characteristic of the surface profile, takes the mean width of the profile elements (Sm) to reflect the width characteristic of the surface profile, takes the material ratio of the profile (tp) to reflect the shape characteristic of the surface profile and takes the altitude density function φ(z) and autocorrelation function R(l) to reflect the statistical characteristic. Four groups of experiments are carried out in which 1Cr18Ni9Ti is taken as the material object of the test piece and test pieces with different initial surface roughness are polished. By experiment, the changing rules of the value of Ra, Sm, tp, φ(z) and R(l) after different polishing time are obtained. By analyzing the changing rules of Ra, Sm, tp, φ(z) and R(l), the influence of the Electrochemical Polishing (ECP) process on the surface geometry and statistical characteristic is obtained.