• Journal of the KSME
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• v.21 no.1
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• pp.6-9
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• 1981

최근의 공작기계에서는 수치제어등에 의한 자동화가 활발히 연구, 실용화되어 우리나라에서도 이미 상당한 양의 NC 공작기계가 가동되고 있다. (1979년까지 도입대수 669대) 이러한 공작기 계에서는 그 생산성과 아울러 정밀도가 요구되며 따라서 이전에는 문제시되지 않았던 열변형에 대한 문제가 정적 및 동적강성도 문제와 함께 공작정도를 향상시키기 위한 중요한 문제로 되고 있다. 최근에는 대형전자계산기가 발달함에 따라 유항요소법은 물론이고 그 제어방법에 대한 연구가 활발히 이루어지고 있다. 그 가운데 Okushima와 Kakino는 열변형을 정상상태에서의 열 변형 내부열원에 의한 열변형, 액체의 순환에 의한 열변형으로 나누어 여기에 유한요소법을 적 용한 연구결과를 발표하고 있다. 이외에도 외기온도의 변화에 의한 공작기계의 열변형에 관한 실험적인 연구도 상당히 이루어지고 있다.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.249-256
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• 2004

STEP-NC 는 기존의 G-code 를 대체할 새로운 CNC 인터페이스 언어로써 현재 밀링 공정에 대해서는 국제 표준 단계에 있으며 조만간 기존의 G-code 를 대체할 것으로 기대된다. 그러므로 국내에서도 CAD-CAM 업체, CNC maker, 공작기계 제작 업체, 사용자 등 생산 환경 전반에 걸쳐 이에 대한 대응이 시급하다. 본 논문에서는 국내에서의 STEP-NC 의 promotion 을 위해 1) STEP-NC data model 을 분석하고, 2) 파트 프로그램의 작성 방법을 자세히 설명하고, 3) STEP AP203 CAD 파일로부터 STEP-NC 파트 프로그램을 생성하는 과정을 Korea STEP-NC 시스템을 통해서 설명하였다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.33
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• pp.11-27
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• 1995

This study sets a goal of establishing work standard and standard time in a machine tool process consisted of high-priced NC machine tools. Firstly, the theories of work standard and standard time in the field of NC machine tools are studies. Secondly, the theories are actually applied to a manufacturing company; work standard sheets are developed and applied to a machining center haying low operation rate, and then the increase in productivity is compared. Finally, problems to be studied later in relation to work standard and standard time are presented.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.12
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• pp.2899-2908
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• 2000

Methodology of volumetric error identification is presented to improve the accuracy of NC machine tools by using a reference artifact and a touch trigger probe. Homogeneous transformation matrix and kinematic chain are used for modeling the geometric and thermal errors of a three-axis vertical machining center. The reference artifact is designed and fabricated to identify the model parameters by machine tool metrology. Parameters in the error model are able to be identified and updated by direct measurement of the reference artifact on the machine tool under the actual conditions which include the thermal interactions of error sources. The proposed method can speed up and simplify volumetric error identification processes.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.12
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• pp.99-105
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• 1996

Increasing demands on precision machining of free-form surfaces have necessitated the tool to move not only with position error as small as possible, but also with smoothly varying feedrates. In this paper, linear, circular and spline interpolators were developed in reference-pulse type using PC. M-SAM and M-DAM were designed by the comparison and analysis of previous interpolation methods. Spline interpolator was designed to follow the free-form curves. To apply to the real cutting process, constant feedrate compensation and acceleration-deceleration compensation were conceived. Finally, its performance was tested using retrofitted milling machine. As a result, new interpolation algorithm is favorable in precision machining of free-form curves.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.1
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• pp.46-53
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• 2007

NC (Numerical Control) code for the tool path needs to be generated efficiently for machining of free form pockets with arbitrary wall geometry on a three axis CNC machine. The unified rough and finish cut algorithm and the tool motion is graphically simulated in Part 1. In this paper, a grid based 3D navigation algorithm simulated in Part 1 for generating NC tool path data for both linear interpolation and a combination of linear and circular interpolation for three-axis CNC milling of general pockets with sculptured bottom surfaces is experimentally performed and verified.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.1
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• pp.82-88
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• 1998

It is very important to test linear cycle positioning accuracy of NC lathes as it affect all other machines machined by them in industries. For example, if the linear positioning accuracy of x or z-axis directions is bad, the size of works will be wrong and the change-ability will be bad in the assembly of machine parts. In this paper , measuring systems are organized to measure linear displacement of ATC(Automatic tool changer) of NC lathe using laser interferometer, magnescale and tick pulses coming out from computer in order to get data at constant time intervals from the sensors, And each set of data gotten from test is expressed to a plots by computer treatment and the results of linear positioning error motion is estimated to numerics by statistical treatments.

• IE interfaces
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• v.17 no.1
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• pp.13-21
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• 2004

In this study, the prototype of a system for checking risk-factor of NC machine is proposed. The proposed system can get the risk-related information by monitoring the status of real-time processes of NC machines. Using the information, the accidents can be prevented by the background process of an expert system tool. This paper consists of 2 parts: (1) the method for gathering data and definition of the risk-related factors of NC machines and (2) the procedure for finding the proper actions by using the forward chaining of a rule-base. Proposed system is implemented with C++ language under MS-windows.

• Journal of the KSME
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• v.20 no.2
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• pp.102-114
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• 1980

산업용로보트는 융통성을 가지는 것이 특징으로 전용 기계에서는 최소한의 융통성이 있을 뿐 다른 일을 수행하기 위해서는 설계를 바꾸든지 못쓰게 되는 것과는 달리 간단히 프로그램이나 티 칭(Teaching)에 의하여 다양한 일을 목적에 맞게 수행 할 수 있다. 손과 같이 다축 운동이 가 능하여 기계 가공의 목적만을 수행하는 수치 제어 기계(NC 공작 기계)와는 다르며 NC 기계와 같은 일도 물론 일부 수행 할 수 있다. 그러므로 산업용 로보트의 이용으로 자동화, 성력화에 따라서 생산성 향상과 또한 높은 신뢰도와 정도로써 품질의 균일화, 악조건하에서의 작업이나 반복되는 단순 작업으로부터 인간을 해방 시킬 수 있으며, 더 나아가 공장의 무인화의 접근이 가능하게 되어가고 있다. 본 글에서는 로보트의 간략한 역사, 개요, 현황, 비용과 경제성, 앞으 로의 동향등에 관하여 개괄하고자 한다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.6
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• pp.1542-1551
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• 1990

This paper shown how to measure the machining error in diameter of cylindrical workpiece and compensate the measured machining error in NC turning. Machining error is measured by the electric micrometer mounted on the tool post with the NC part program for probe location path analyzed. Correct NC part program for finish turning is automatically generated to compensate the measured machining error. These concepts have been effectively introduced to a newly developed software for error compensation. In turning experiments with the developed error compensation system, machining error was almost within the specified tolerance, which reveals the effectiveness of the developed system.