• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2007년도 정기학술발표대회 논문집
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• pp.929-933
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• 2007

콘크리트 도로 표면절삭 작업은 장비 조작자의 숙련도에 따라서 작업의 완성도 및 품질, 작업 생산성에 크게 영향을 준다. 콘크리트 표면절삭 작업을 자동화하기 위해서는 시스템 하드웨어 구축과 지원 소프트웨어의 개발 등이 필요하다. 표면 절삭 프로세스를 자동화 하기 위해서 가장 먼저 선행 되어야 할 부분은 진로계획의 수립이다. 장비의 진로계획을 통하여 기존 시스템이 가지고 있는 진로계획에 대한 취약점을 보완하며, 보다 효율적인 생산성을 가진 자동화 시스템을 구축 하도록 한다. 본 연구는 CAD를 기반으로 한 AUTO-Lisp를 이용하여 표면절삭 작업의 최적 경로계획을 결정하고 MMI 시스템 상에 적용하여 실시간으로 진행 경로 보정을 위한 진로 계획의 데이터 갱신을 통해서 보다 효율적인 생산성과 품질을 가진 표면절삭 작업을 하는데 목적이 있다. 그리고 도로 표면절삭 장비의 자율주행 진로계획 수립을 위한 AUTO-Lisp 파일 및 MMI 시스템과의 연계, 계획된 경로를 적용한 표면절삭 장비와 MMI 시스템을 직접 현장에서 테스트하여 실제 표면절삭 작업의 자동화 구현 및 절삭작업의 효율성을 높일 수 있는 방안을 제시하였고, 표면절삭 작업의 최적진로를 결정함으로써 경제성 있는 절삭작업을 수행 할 수 있다.

• 한국CDE학회논문집
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• 제4권3호
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• pp.247-258
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• 1999

With the contemporary CAD/CAM system, where the tool path is generated and verified purely based on the geometric operation, geometric accuracy of the machined surface cannot be guaranteed dut to the cutting mechanics, meaning that the cutting mechanics should be incorporated in some fashion. In this paper, we incorporate the instantaneous cutting force and the tool deflection phenomena in predicting the machined surface for the finish-cut and milling operation. For the given NC dat including cutting conditions, the developed algorithm computes cutting force and deflection amount along the tool trajectory, and outputs the 3D graphic model of the machined surface together with error analysis. The validity and accuracy of the presented method has been tested by the actual cutting experiments. Experimental results and accuracy enhancement method together with implementing architecture of the VMCS (Virtual Machining CAM System) are discussed in the paper.

• 한국정밀공학회지
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• 제21권8호
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• pp.43-49
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• 2004

The objective of this research is to investigate the effect of clearance angle on cutting performance in high speed end milling operation. The tool geometry parameters have complex relationship with cutting process parameter. In order to explain the effect of clearance angle, 2D turning operation in lathe and end milling operations are performed. Tools with different clearance angles are manufactured. Cutting forces, machining accuracy and tool life are examined according to the change of clearance angle. As clearance angle increases, cutting force decreases and machining accuracy improves. But it has been proved that there exists the optimal clearance angle according to the diameter of end mill for maximum tool life which is measured by frank wear.

• 한국CDE학회논문집
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• 제6권4호
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• pp.222-228
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• 2001

In the milling operation, the burr can be generated on the intersection of cutting tool and workpiece. Due to burr formation, we expect lower efficiency in the operation and the cost increase. In order to understand the burr formation mechanism in the milling operation on the arbitrary feature, we developed an algorithm to analyse and predict the exit burr formation mechanism. Firstly, the recognition of arbitrary shaped workpiece was done through the CAD data. This data includes point information on the vertices of the workpiece. Secondly, tile CAM data regarding tool geometry, tool path, cutting speed, and material data are retrieved to simulate the actual cutting process. Thirdly, we predict the exit burr formation on the edge of workpiece based on the geometric analysis. Lastly, an algorithm implemented in the Windows environment to visualize the burr formation simulation. With this information, we can predict which portion of workpiece would have the exit burr in advance so that we call manage to find a way to minimize the edit burr formation in the actual cutting.

• Industrial Engineering and Management Systems
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• 제14권2호
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• pp.175-182
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• 2015

The recent manufacturing industry in Japan has found it difficult to transfer skills from trained workers to inexperienced workers because the former ages and then retires. This is a particular problem for lathe process, as this operation requires explicit and tacit knowledge, and defining the skills clearly in a manual is difficult. This study aims to develop a training system for lathe operation by using a simulator; this includes formulas that help define the relationship between the speed of tool feed and cutting sound/shape of chips which were proposed in the preceding study. The developed training system is verified the effectiveness.

• 한국안전학회지
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• 제21권6호
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• pp.116-121
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• 2006

절삭가공에서 가공조건은 가공비용의 감소와 제품 품질의 향상에 영향을 주는 주요 요인 중의 하나이다. 일반적으로 공정설계자는 제품의 목표 품질을 만족하는 범위 내에서 비용을 줄일 수 있는 가공조건을 결정하기 위하여, 가공조건 핸드북 등에서 제공하는 표준 가공조건을 세부 공정별 요구 사항이 만족되도록 경험을 기반으로 수정한 후 작업자의 안전에 문제가 없는 지 검토한다. 본 논문에서는 공정설계자의 경험에 의해 수행되는 일련의 과정을 신경회로망 모델과 규칙에 의해 모델링한 작업설계시스템을 소개한다. 개발된 시스템은 각주형 부품의 밀링 작업에서 (1) 표준 가공조건을 세부 공정별 요구 사항이 만족되도록 신경회로망 모텔에 의해 수정하고, (2) 다음으로 작업자의 안전을 만족하도록 수정된 가공 조건을 필터링하는 모듈로 구성된다. 본 논문에서는 우선 개발된 밀링 작업설계시스템의 전반적인 기능을 간략히 소개한 후, 제안된 방법론에 의한 의사결정 과정을 자세히 기술한다. 마 지막으로 실제 적용 예를 통하여 개발된 시스템의 성능을 예시하도록 한다.

• 한국정밀공학회지
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• 제16권4호통권97호
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• pp.229-236
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• 1999

The surface, generated by end milling operation, is deteriorated by tool runout, vibration, tool wear and tool deflection, etc. Among them, the effect of tool deflection on surface accuracy is analyzed. Surface generation model for the prediction of the topography of machined srufaces has been developed based on cutting mechanism and cutting tool geometry. This model accounts for not only the ideal geometrical surface, but also the deflection of tool due to cutting force. For the more accurate prediction of cutting force, flexible end mill model is used to simulate cutting process. Computer simulation has shown the feasibility of the surface generation system. Using developed simulation system, the relations between the shape of end mill and cutting conditions are analyzed.

• 대한산업공학회지
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• 제27권1호
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• pp.69-88
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• 2001

In the zigzag milling operation, an important issue is to design a machining strategy which minimizes the cutting time. An important variable for minimization of cutting time is the tool path length. The tool path is divided into cutting path and non-cutting path. Cutting path can be subdivided into tool path segment and step-over, and non-cutting path can be regarded as the tool retraction. We propose a new method to determine the cutting direction which minimizes the length of tool path in a convex or concave polygonal shape including islands. For the minimization of tool path length, we consider two factors such as step-over and tool retraction. Step-over is defined as the tool path length which is parallel to the boundary edges for machining area and the tool retraction is a non-cutting path for machining any remaining regions. In the determination of cutting direction, we propose a mathematical model and an algorithm which minimizes tool retraction length in complex shapes. With the proposed methods, we can generate a tool path for the minimization of cutting time in a convex or concave polygonal shapes including islands.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
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• pp.14-18
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• 2001

Rise in cutting force causes tool damage and worsens product quality resulting in machining accuracy deterioration. Especially, fragile material cutting brings about breakage of material and worsens product surface quality. In this study, we trace the locus of cutting force and examine the machined surface corresponding to the cutting force loci. and build up a monitoring system for deciding normal operation or not of cutting process.

• 한국공작기계학회논문집
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• 제10권3호
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• pp.97-103
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• 2001

This paper has focused on the Optimization of the cutting parameters for urning operation based on the Taguchi method. Four cutting parameters. nemely, cutting speed, feed depth of cut and nose radius are optimized with consideration of the surface roughness. The design and analysis of experiments are conducted to study the performance characteristic. The effects of these parameters on the surface roughness have been investigated using signal-to-noise(S/N) ratio and analy-sis of variance(ANOVA). The experiments have been performed using coated tungsten carbide inserts without any cutting fluid. Experimental results illustrate the effectiveness of this approach.