Simulation Investigation of Tangential-Feed Centerless Grinding Process Performed on Surface Grinder

2009 ◽  
Vol 626-627 ◽  
pp. 23-28
Author(s):  
Wei Xing Xu ◽  
Yong Bo Wu ◽  
Takashi Sato ◽  
Wei Min Lin
Keyword(s):  
Elastic Deformation ◽  
Process Parameters ◽  
Simulation Method ◽  
Machining Accuracy ◽  
Grinding Process ◽  
Elasticity Parameter ◽  
Grinding Method ◽  
Centerless Grinding ◽  
Simulation Results ◽  
Grinding Technique

In our previous study, a new centerless grinding method using surface grinder was proposed. This paper describes a simulation method for investigating the workpiece rounding process in which a model taking the elastic deformation of the machine into consideration is created, and revealing how the process parameters affect the machining accuracy in the new grinding technique. In addition, a practice way to determine the machining-elasticity parameter showing the elastic deformation is developed. The simulation results are compared to show the effect of process parameters on the machining accuracy.

Research on the Optimization of Porosity in Resin Mineral Composite

2012 ◽  
Vol 217-219 ◽  
pp. 55-58 ◽  
Author(s):  
Tao Wang ◽  
Jian Hua Zhang ◽  
Shi Mei Hao ◽  
Xiu Hua Ren
Keyword(s):  
Mechanical Properties ◽  
Euclidean Geometry ◽  
Fractal Theory ◽  
Simulation Method ◽  
Critical Dimension ◽  
Machining Accuracy ◽  
Interference Theory ◽  
Optimal Method ◽  
Simulation Results ◽  
Variation Tendency

With good vibration alleviating properties, resin mineral composite (RMC) has been used to produce precision machine tool beds to satisfy the requirements of machining accuracy. Aggregate is one of the key components in RMC to bear loads, its gradation design determines the overall mechanical properties of the composite directly. In this article, an optimal method to determine critical dimension of screen holes is proposed based on Euclidean geometry and Particle interference theory, and the corresponding proportion of each component is adjusted on the basis of fractal theory. Variation tendency of porosity corresponding to different fractal dimension is obtained by using simulation method. On this basis, image processing technology is used to validate the aforementioned assumptions. Experimental results show that the optimal design has smaller porosity performance, which is consistent with the simulation results.

Experimental Study of Tangential-Feed Centerless Grinding Process Performed on Surface Grinder

2009 ◽  
Vol 626-627 ◽  
pp. 17-22 ◽  
Author(s):  
Wei Xing Xu ◽  
Yong Bo Wu ◽  
Takashi Sato ◽  
Z. Liang ◽  
Wei Min Lin
Keyword(s):  
Experimental Study ◽  
Feed Rate ◽  
Rotational Speed ◽  
Grinding Process ◽  
Grinding Method ◽  
Elliptic Vibration ◽  
Centerless Grinding ◽  
Grinding Operations ◽  
Stock Removal ◽  
Rotational Speed Control

In our previous study, a new centerless grinding method using surface grinder was proposed. In this method, a compact unit consisting mainly of an ultrasonic elliptic-vibration shoe, a blade, and their respective holders is installed on the worktable of a multipurpose surface grinder to conduct tangential-feed centerless grinding operations. For the complete establishment of this new method, firstly in this paper workpiece rotational speed control tests were carried out to make sure that the workpiece rotational speed is exactly controlled by the elliptic vibration of shoe to achieve high-precision centerless grinding. Then, the effects of the process parameters such as the worktable feed rate, the stock removal and the workpiece rotational speed on the workpiece roundness were clarified experimentally. The obtained results showed that (1) The workpiece rotational speed can be controlled exactly by the shoe ultrasonic vibration, (2) The roundness is improved with the increases in the voltage applied and the stock removal, but the decrease in the worktable feed rate; The best roundness obtained was 0.84m.

Study on Precision Grinding Technique for Large Size Optical Aspheric Lens

2013 ◽  
Vol 395-396 ◽  
pp. 1015-1019 ◽  
Author(s):  
Xiao Long Ke ◽  
Jian Chun Liu ◽  
Hai Bin Huang
Keyword(s):  
Diamond Wheel ◽  
Surface Measurement ◽  
Machining Accuracy ◽  
Precision Grinding ◽  
Aspheric Lens ◽  
Grinding Method ◽  
Large Size ◽  
Grinding Technique ◽  
Measurement And Evaluation ◽  
Grinding Machine

Large size optical aspheric lens is an important component in optical engineering. Aiming at the demand of precision processing for optical aspheric lens, this paper develops a precision grinding technique for large size optical aspheric lens. Based on precision surface grinding machine (MGK7160), grating-type parallel grinding method is put forward to realize grinding paths planning for optical aspheric lens. An on-machine measurement system is built to obtain surface measurement and evaluation after grinding. In order to ensure machining precision and efficiency, a diamond truer which self-developed is adopted to precision dress for arc diamond wheel. Finally, the experiment of precision grinding and error compensation validates machining accuracy for large size optical aspheric lens.

ELID Grinding Characteristics and Surface Analysis for Micro Fabrication of Advanced Ceramics

2007 ◽  
Vol 339 ◽  
pp. 483-489 ◽  
Author(s):  
Kazutoshi Katahira ◽  
Hitoshi Ohmori
Keyword(s):  
Surface Hardness ◽  
Ground Surface ◽  
Ceramic Materials ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Spherical Lens ◽  
Elid Grinding ◽  
Grinding Method ◽  
Centerless Grinding ◽  
Ground Surface Roughness

The present paper describes the highly efficient and precise ELID grinding method and presents a discussion on the ELID grinding process and the grinding characteristics of several kinds of ceramic materials. The following conclusions are obtained; (1) Good ground surface roughness and accuracy are achieved using the #4000 metal-bonded grinding wheel in through-feed centerless grinding for ZrO2 optical fiber ferrules. (2) Efficient and precise grinding of spherical lens molds with cup wheels using the ELID CG-grinding process was proposed and tested in the present study. (3) The ELID grinding method can be used to fabricate machined surfaces exhibiting desirable characteristics for hard AlN ceramics. The ELID ground AlN demonstrated a surface hardness and sliding characteristics that were superior to those of the polished series. These advantages may be attributable to the diffusion phenomenon of the oxygen element produced by the ELID grinding.

scholarly journals An Investigation into Accumulative Difference Mechanism in Time and Space for Material Removal in Micro-EDM Milling

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 711
Author(s):  
Qi Jing ◽  
Yongbin Zhang ◽  
Lingbao Kong ◽  
Min Xu ◽  
Fang Ji
Keyword(s):  
Cross Section ◽  
Process Parameters ◽  
Material Removal ◽  
Machining Accuracy ◽  
Tool Electrode ◽  
Micro Edm ◽  
Cylindrical Electrode ◽  
Time And Space ◽  
Simulation Results ◽  
The Cross

In micro-electrical discharge machining (micro-EDM) milling, the cross-section of the microgroove machine is frequently not an ideal rectangle. For instance, there are arc shapes on the bottom and corners, and the sidewall is not steep. The theoretical explanation for this phenomenon is still lacking. In addition to the tip discharge effect, the essential reason is that there is an accumulative difference in time and space during the shape change process of a tool electrode and the microstructure formation on a workpiece. The process parameters are critical influencing factors that determine this accumulative difference. Therefore, the accumulative difference mechanism in time and space is investigated in this paper, and then a theoretical model is developed to simulate the micro-EDM milling process with a straight-line single path. The simulation results for a cylindrical electrode at the two rotational speeds of 0 (nonrotating) and 300 rpm are compared, while the results for a cylindrical electrode and a square electrode at a rotation speed of 0 are also compared to verify that different process parameters generate accumulative differences in the time and space of material removal. Finally, micro-EDM milling experiments are carried out to verify the simulation model. The maximum mean relative deviation between the microgroove profiles of simulation results and those of experiments is 11.09%, and the profile shapes of simulations and experiments have a good consistency. A comparative experiment between a cylindrical electrode and a hollow electrode is also performed, which further verifies the mechanism revealed in the study. Furthermore, the cross-section profile of a microgroove can be effectively controlled by adjusting the process parameters when utilising these accumulative differences through fabricating a microgroove with a V-shaped cross-section by a square electrode and a microgroove with a semi-circular cross-section by a cylindrical electrode. This research provides theoretical guidance for solving the problems of the machining accuracy of detail features in micro-EDM milling, for instance, to machine a microgroove with an ideal rectangular cross-section.

Study of HVDC System and Subsynchronous Oscillation

2015 ◽  
Vol 1092-1093 ◽  
pp. 356-361
Author(s):  
Peng Fei Zhang ◽  
Lian Guang Liu
Keyword(s):  
Power Plant ◽  
Time Domain ◽  
Simulation Method ◽  
Time Domain Simulation ◽  
Stable Convergence ◽  
Turbine Generator ◽  
Plant Model ◽  
Subsynchronous Oscillation ◽  
Hvdc System ◽  
Simulation Results

With the application and development of Power Electronics, HVDC is applied more widely China. However, HVDC system has the possibilities to cause subsynchronous torsional vibration interaction with turbine generator shaft mechanical system. This paper simply introduces the mechanism, analytical methods and suppression measures of subsynchronous oscillation. Then it establishes a power plant model in islanding model using PSCAD, and analyzes the effects of the number and output of generators to SSO, and verifies the effect of SEDC and SSDC using time-domain simulation method. Simulation results show that the more number and output of generators is detrimental to the stable convergence of subsynchronous oscillation, and SEDC、SSDC can restrain unstable SSO, avoid divergence of SSO, ensure the generators and system operate safely and stably

Performing in-feed type centerless grinding process on a surface grinder

2011 ◽  
Author(s):  
W. Xu ◽  
Y. Wu ◽  
T. Sato ◽  
W. Lin ◽  
Francisco Chinesta ◽  
...  
Keyword(s):  
Grinding Process ◽  
Centerless Grinding

Numerical Analysis on the Extruded Volume and Length Ratios of Backward Tube to Forward Rod in Combined Extrusion Processes

2006 ◽  
Vol 519-521 ◽  
pp. 919-924 ◽  
Author(s):  
B.S. Ham ◽  
J.H. Ok ◽  
Jung Min Seo ◽  
Beong Bok Hwang ◽  
K.H. Min ◽  
...  
Keyword(s):  
Process Parameters ◽  
Material Flow ◽  
Volume Ratio ◽  
Forward Direction ◽  
Extrusion Process ◽  
Forming Load ◽  
Tube Extrusion ◽  
Corner Radius ◽  
Combined Operation ◽  
Simulation Results

This paper is concerned with forward rod extrusion combined simultaneously with backward tube extrusion process in both steady and transient states. The analysis has been conducted in numerical manner by employing a rigid-plastic finite element method. AA 2024 aluminum alloy was selected as a model material for analysis. Among many process parameters, major design factors chosen for analysis include frictional condition, thickness of tube in backward direction, punch corner radius, and die corner radius. The main goal of this study is to investigate the material flow characteristics in combined extrusion process, i.e. forward rod extrusion combined simultaneously with backward tube extrusion process. Simulation results have been summarized in term of relationships between process parameters and extruded length and volume ratios, and between process parameters and force requirements, respectively. The extruded length ratio is defined as the ratio of tube length extruded in backward direction to rod length extruded in forward direction, and the volume ratio as that of extruded volume in backward direction to that in forward direction, respectively. It has been revealed from the simulation results that material flow into both backward and forward directions are mostly influenced by the backward tube thickness, and other process parameters such as die corner radius etc. have little influence on the volume ratio particularly in steady state of combined extrusion process. The pressure distributions along the tool-workpiece interface have been also analyzed such that the pressure exerted on die is not so significant in this particular process such as combined operation process. Comparisons between multi-stage forming process in sequence operation and one stage combined operation have been also made in terms of forming load and pressure exerted on die. The simulation results shows that the combined extrusion process has the greatest advantage of lower forming load comparing to that in sequence operation.

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