• Journal of Computational Design and Engineering
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• 제2권4호
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• pp.248-252
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• 2015

Currently composite manufacturing process, such as linear friction welding plus NC machining, is the main method for the manufacturing and repairing of complex parts with integrated structure. Due to different datum position and inevitable distortion from different processes, it is important to ensure sufficient machining allowance for complex parts during the NC machining process. In this paper, a workpiece localization approach for machining allowance optimization of complex parts based on CMM inspection is developed. This technique concerns an alignment process to ensure sufficient stock allowance for the single parts as well as the whole integrated parts. The mathematical model of the constrained alignment is firstly established, and then the symmetric block solution strategy is proposed to solve the optimization model. Experiment result shows that the approach is appropriate and feasible to distribute the machining allowance for the single and whole parts for adaptive machining of complex parts.

• 한국공작기계학회논문집
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• 제15권6호
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• pp.38-43
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• 2006

A slot cut in end milling processes is one of the laborious works because the cutting force is likely to deflect the tools excessively, then to make large errors or to fracture the tool. This difficulty is owing to the poor stiffness of slender shaped end mills. Though, in most cases, additional finish cuts are followed after rough cuts, the accuracy of rough cuts is still important because it affects the final accuracy after finish cuts and productivity. The accuracy in slot cuts depends on the tool stiffness and the cutting conditions including depth of cut and feed. In order to meet the desired accuracy, diameter of end mill and cutting allowance have to be selected carefully. This study suggests several guidances for selecting the end mill diameter and the slot cut allowance to improve machining accuracy and productivity in slot end millings. Some experiments were done with the various cutting parameters of tool diameter, depth of cut and feed.

• 한국기계가공학회지
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• 제20권1호
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• pp.57-65
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• 2021

With the increased utilization of CAM programs, end-mill processing is most commonly used for machining and metal processing. In particular, hole or shaft machining has high assembly precision, which inevitably leads to high utilization of end mills. However, the analysis of quality characteristics according to the process conditions of end mills is not performed systematically at the site, causing poor quality and productivity. The most influential factor of quality is the runout of the end mill. In this paper, the number of turns of the end mill, number of tool blades, cutting direction, and artificial runout volume were determined to identify the correlation between the epicenter, cylindricality, and surface roughness. Two types of end mills, three levels of runout, three levels of rotational speed, and two cutting directions were considered and 36 rounds of hole processing were conducted. For the analysis of shape characteristics according to the set process variables, the experimental planning method was applied to the measured specimen and the processing characteristics were analyzed according to the runout of the end mill through correlation analysis.

• 한국정밀공학회지
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• 제22권8호
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• pp.100-107
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• 2005

The objective of the study is to improve the quality of wheel bearing hub by the rigid-plastic finite element analysis and the response surface methodology. The rigid-plastic finite element codes, AFDEX-2D and DEFORM-3D, were used to analyze the two-dimensional and three-dimensional forging processes, respectively. The response surface analysis is used to find the minimum underfill by the variation of design variables such as the height of billet after upsetting and punch angles of blocker dies. The metal flow of forged product shows good agreement with the results from 2D and 3D analysis. Also, the quality of the wheel bearing hub has been improved by the optimization of design variables and the machining time has been reduced by the machining allowance.