• 소성∙가공
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• 제16권1호
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• pp.15-19
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• 2007

This paper presents an integrated machining error compensation method based on captured images of tool deflection shapes in flat end-milling processes. This approach allows us to avoid modeling machining characteristics (cutting forces, tool deflections and machining errors etc.) and accumulating calculation errors induced by several simulations. For this, a high-speed camera captured images of real deformed tool shapes which were cutting under given machining conditions. Using image processes and a machining error model, it is possible to estimate tool deflection in cutting conditions modeled and to compensate for machining errors using an iterative algorithm correcting tool paths. This corrected tool path can effectively reduce machining errors in the flat end-milling process. Experiments are carried out to validate the approaches proposed in this paper. The proposed error compensation method can be effectively implemented in a real machining situation, producing much smaller errors.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 추계학술대회 논문집
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• pp.433-438
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• 2004

The rapid machining of prototypes plays an important role in product process. Rapid Prototyping(RP) is the widespread technology to produce prototype. But, it have many problems such as shrinkage, deformation and formation occurred by hardening of resin and stair shaping, On the contrary, high speed machining(HSM) technology has many advantages such as good quality, low cost and rapid machining time. Moreover, it is possible to use the material of original product. This paper presents manufacture of trial product by HSM and optimization of machining condition for high productivity in the view of manufacturing time and average error. For example, propeller is machined by the surface machining of thin surface parts. Experiments are designed of machining conditions by Latin Square method and machining condition is optimized and selected by ANOVA

• 한국CDE학회논문집
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• 제4권4호
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• pp.355-359
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• 1999

This paper presents a method for determining machining parameters in electrical discharge machining process (EDM) based on discharge area. The parameters are the peak value of currents, the pulse-on time, and the pulse-off time, on which the EDM performance depends chiefly. The optimal machining parameters are closely related on discharge area, which can be calculated from a tool electrode and a discharge height. In the paper the discharge area is obtained from NC code for machining the tool electrode instead of its geometric model. The method consists of following three steps. First a Z-Map model is constructed from the NC code. Secondly, the discharge area is obtained from the Z-Map model and a Z-height. Finally, the machining parameters are calculated from the discharge area. An introduced example shows that the machining parameters are calculated by the using a Z-map model obtained from the machining data for a tool electrode.

• 한국CDE학회논문집
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• 제16권4호
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• pp.260-267
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• 2011

Nowadays, automobile manufacturers are faced with increasing global competition which is required low cost as well as high quality. To reduce shipping and handling cost and delivery time, lots of automobile manufactures tried to build their new factory in the neighborhood of market. Simultaneously, many factories are under construction in developing countries to make efficient use of low-wage workers. However, because systems are installed in developing countries as the same type of domestic facilities, systems have lots of problems such as high installation cost and inefficient use of manpower. To find core problems and generate optimal solution of these problems, thinking process of TOC(Theory Of Constrains) is used. In case of transmission gear machining system, semi-auto system is proposed as the best solution to increase manpower efficiency and system utilization. Semi-auto system consists of automatic machining process and manual transporting process. The system layout is generated based on semi-auto process concept. And, 3D simulation method using QUEST is used to verify production volume of generated system.

• 한국기계가공학회지
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• 제7권3호
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• pp.96-102
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• 2008

In order to design establish automation or optimization of the machining process, predictions of the forces in machining are often needed. In this paper, a theoretical model in face milling is presented based on Oxley's predictive machining theory, where the cutting forces are predicted from input data of fundamental work material properties, tool geometry and cutting conditions without any preliminary cutting experiment. A simulation system for the cutting forces in face milling is developed using the model. Milling experimental tests are conducted to verify the model and the predictive results are compared and discussed with the experimental results.

• 한국CDE학회논문집
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• 제9권2호
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• pp.175-182
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• 2004

As a bridge between design and manufacturing, process planning is to generate a sequenced set of instructions to manufacture the specified part. Automatic interpretation of manufacturing information incorporated in the design documentation such as CAD file has been a knotty subject for manufacturing engineers since no current data exchange format for product data provides a perfect interface between heterogeneous systems. The recent neutral data exchange format STEp, standard for the exchange of product model data, includes not only geometry but also technical and managerial information. STEP AP(Application Protocol) 224 is specifically dedicated to the mechanical product definition for process planning using machining features. Given a design information in STEP AP 224 format, process planning can be made without human intervention. This paper describes a method to determine the sequence of machining features by using the machining features and the manufacturing information expressed in STEP AP224.

• 산업경영시스템학회지
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• 제19권40호
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• pp.143-155
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• 1996

Presented in this paper are a CAPP(Computer Automated Process Planning) scheme and a generating method of intelligent NC data for unmaned machining of mold die. Mold die surfaces usually have free-formed geometry of complex shapes. So it is easy to overcut the die surface and to overload the cutting tools. It takes tens of hours to prepare process plans and to generate NC data for each processes. Therefore a classification of unit machining operation(UMO) for mold die manufacture, a backward recursive capp algorithm and a generating method of intelligent NC data are presented in this paper in order to provide a unmaned machining architecture of mold die.

• 한국기계가공학회지
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• 제10권1호
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• pp.1-7
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• 2011

Micromachining is gaining popularity due to recent advancements in MEMS(Micro Electro Mechanical Systems). Using conventional micromachining, it is relatively difficult to produce moving components in the order of microns. Photolithography for silicon material has high accuracy machining, but it has low aspect ratio. X-ray lithography has ultra high accuracy machining, but it has expensive cost. Micro-EDM(electro discharge machining) has been gaining popularity as a new alternative method to fabricate micro-structures. In this study, Micro-EDM machine is developed available for fabricate micro-structures and two processes such as side cut EDM and milling EDM is proposed. Several sets of experiment results have been performed to study the characteristics of the machining process.

• 한국생산제조학회지
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• 제9권5호
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• pp.34-39
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• 2000

Application of ceramics has grown considerably due to significant improvement in their mechanical properties such as light weight, chemical stability and superior wear resistance. Despite these character, the use of ceramics has not increased because of poor machinability. The method of using of super-abrasives metal bond wheel was proposed. But it is difficult that super-abrasives metal bond wheel can be dressed. Recently, the technology of in-process electrolytic dressing is developed to solve this problem. If this method is applied, loading and glazing are disappeared apparently. The aim of this study is to determine the machining characteristics in terms of lapping wheel speed, machining time, pressurized weight to the workpiece and peak current using in-process electrolytic dressing applied to the CIB-diamond lapping wheel to achieve ultra-precision lapping machining technique.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.508-511
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• 2002

With increasing the needs for micro and precision parts, micro machining technology using micro tools has been studied to fabricate a small part with high density such as electronics, optics, communications, and medicine industry more than before. Though these micro tools have developed rapidly, it is difficult to apply them to micro fabrication technologies, because of the inherent manufacturing. In this study, micro tools(wc) to produce micro structures and parts were manufactured by cylindrical grinding machine employing ELID(Electrolytic In-process Dressing) technique and good dimensional accuracy was achieved. Furthermore we researched the characteristics of machining on the micro drilling using micro drills and manufactured micro tools. Finally it is confirmed that manufactured micro tools can be used for micro machining.