• 한국시뮬레이션학회논문지
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• 제12권3호
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• pp.41-53
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• 2003

The major components of an engine are engine block (or cylinder block), cylinder head, crank shaft, connecting rod and cam shaft. Thus the engine shop usually consists of six sub-lines, five machining lines and one assembly line. Flow line is the typical concept of layout for machining these parts, especially for engine block. In order to design an engine block machining line, several factors should be considered such as yearly production target, working hours, machines, tools, material handling equipments and so on. If the designers of manufacturing line were unaware of some factors those would be influenced on the system performance, it would make greater problems in the phase of mass production. Therefore the initial design of engine block machining line should be verified carefully. Simulation is the most powerful tool for analyzing the initial layout. This paper introduces the major factors those should be considered for designing the machining line and their effects on the system performance. 3D simulation models are developed with QUEST. Using the simulation model developed the initial layout is analyzed, and we suggest some ideas for improvement.

• 한국CDE학회논문집
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• 제5권2호
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• pp.155-167
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• 2000

To be presented is two-dimensional chip-load analysis for cutting-load smoothing which is needed in unmanned machining and high speed machining of sculptured surfaces. Cutter-engagement angle and effective cutting depth are defined as chip-loads which are the geometrical measures corresponding to cutting-load while machining. The extreme values of chip-loads are geometrically derived in the line-line and line-arc-line blocks of the two-dimensional NC-codes. AFA(automatic feedrate adjustment) strategy for cutting-load smoothing is presented based on the chip-load trajectories.

• 한국CDE학회논문집
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• 제7권3호
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• pp.141-147
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• 2002

Profile machining using cutter diameter compensation is widely used in die and mould manufacturing. Especially automotive die makers try to use 3D-profile machining for trimming or flange dies. But the technological requirements and implementation issues haven't been defined. In this paper we summarized the requirements and issues of 3D-profile machining. Approximation of input profiles into sequences of line and helical arc is the first major issue. The second major issue is removing cutter inter- ference from the approximated curves holding z-values when the maximum cutter diameter is given. Keeping constant machining width, local machining, path linking problems and several detail technological requirements are also discussed.

• 한국기계가공학회지
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• 제20권8호
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• pp.86-92
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• 2021

As interest and demand for high value-added industries, including the global automobile and aerospace industries, have increased recently, demand for line centers with excellent performance that can respond to the production system for producing high value-added products is also rapidly increasing. A line center improves productivity based on the installed area using a multi-spindle compared to a conventional machining center. However, as the number of spindles increases, the weight increases and results in structural problems owing to the heat and vibration generated by each spindle. Therefore, it is necessary to improve machining precision through the structural improvement of the line center. This study presents research on the stabilization design of the line center through structural stability analysis through structural analysis to develop a compact multi-axis line center. An optimization model of the line center has been proposed to improve the processing precision and increase the rigidity by performing weight reduction based on the structural analysis results.

• 한국CDE학회논문집
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• 제7권4호
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• pp.254-261
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• 2002

Small marine propeller is generally machined by 5-axis machining. This paper suggests a method to create geometric model from point array data and 4-axis machining NC data for propeller. With conventional method, the setting posture should be changed, because propeller has front and back surface of wing. The change of setting posture has a bad influence on precision of propeller. So this paper pro-poses a method to machine propeller by single setup for 4-axis machining. The cutter moves to parallel direction of the XY plane. To determine the cutter orientation efficiently, the' tilting guiding line' is proposed. A proposed algorithm is written in C language and successfully applied to the 5-axis milling machine of industrial field.

• 한국시뮬레이션학회논문지
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• 제17권2호
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• pp.1-12
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• 2008

자동차 엔진을 구성하는 주요부품은 실린더블록, 실린더헤드, 크랭크샤프트, 커넥팅로드, 캠샤프트 등으로 구성되는데 이들의 영문명을 따서 5C라고 부른다. 따라서 일반적으로 엔진공장은 5C를 생산하는 라인과, 엔진 조립라인을 포함하는 6개의 라인으로 구성이 된다. 엔진공장은 소품종대량생산의 특성을 가지기 때문에 장비의 배치형태는 흐름라인의 형태를 따른다. 본 논문에서는 국내 자동차 회사 엔진공장의 크랭크샤프트라인 설계를 위한 시뮬레이션 사례를 소개한다. 크랭크샤프트 라인은 기계가공을 중심으로 하는 라인이다. 따라서 라인설계에 영향을 미치는 요인들에 대해 소개하고, 라인 효율에 미치는 영향을 $QUEST^{(R)}$라는 3차원 시뮬레이션 도구를 이용하여 분석하였다. 기술팀에서 제시한 초기배치안에 대해 시뮬레이션 모델을 구축한 후 실험을 통하여 시스템 효율을 개선시키기 위한 방법을 제시하였다.

• 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.

• 한국시뮬레이션학회논문지
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• 제9권1호
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• pp.1-9
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• 2000

When a new manufacturing line is constructed, its production capacity can be substantially affected in its design stage. Computer simulation often provides better design by evaluating feasible alternatives. In this paper we study an automobile engine manufacturing line which is under construction. Three alternatives are considered in the design; (1) to use machining tools of longer life; (2) to reassign the buffer space to each sequential processes while maintaining the same total buffer length; and (3) to reduce the machine repair time to 30 minutes using TPM and maintenance team. Simulation results using AutoMod indicates that employing the three alternatives will save about 1.5 million dollars per year.

• 대한산업공학회지
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• 제38권1호
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• pp.7-16
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• 2012

Manufacturing system design poses many challenges for new factory construction. Factories producing the same product may nevertheless have different layouts. The machining line of the engine shop in an automotive factory is a typical flow line, but the layout concept of the line varies among factories. In this paper, a simulation study on the design concept of the manufacturing system for automotive engines is discussed. For comparison, three types of real engine block lines in different factories are analyzed, and three structures of parallel lines are extracted. The effects of failure distribution on the performance measures of three types of parallel line structures are investigated, and some insights are offered regarding the layout concept.

• 대한기계학회논문집A
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• 제40권1호
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• pp.121-128
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• 2016

본 연구는 선박용 프로펠러 주물 생산을 위한 후란주형 설계 및 가공 시스템을 개발하였다. 대형 선박용 프로펠러는 시멘트 혹은 후란 소재로 상형 및 하형 주형을 제작하고, 주조를 통해 소재를 제작한다. 이후 주물소재에 대한 일련의 기계가공 및 사상을 거쳐 제품을 완성한다. 기존 후란주형은 수작업을 통한 조형을 통해 제작되므로 세부 공정이 많아질뿐더러, 상당한 소재여유가 존재함으로써 기계가공 및 사상 공수가 증가한다. 이에 따라 후란주형의 제작 정밀도를 향상하고, 생산과정의 표준화 및 생산성 향상을 위해 설계 소프트웨어 및 6축 로봇을 이용한 후란주형 제작 시스템을 개발하였다.