• 대한기계학회논문집
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• 제17권9호
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• pp.2286-2293
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• 1993

The study presents the development of a cost-effective CAD/CAM system for metal moulds by use of personal computer. In the personal CAD/CAM system named DKSYS, metal moulds are defined by the operations of basic elements such as prism, pyramid and sphere, plane, rotational body, and surface elements including curved surface. The internal expression of shape elements in the computer is based on the wire model, which is a set of cross-sectional curves of the shape elements. With the addition of OMS system to CAD/CAM system the optimum cutting condition can be selected automatically. After programming NC information with the form definition and the optimum cutting condition, the metallic mould can be formed by transferring cutting information to CNC machine through DNC system. Using a computer for the above process, it is possible to increase the productivity and reduce the cost.

• 비파괴검사학회지
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• 제11권1호
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• pp.31-37
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• 1991

Acoustic emission(AE) signals detected during metal cutting were applied as the experimental test to sensing tool wear and chipping on the NC vertical milling machine. The in-process detection of cutting tool wear including chipping, cracking and fracture has been investigated by means of AE in spite of vibration or noise through intermittent metal cutting, then the following results were obtained 1) When the tool wear is increased suddenly, or the amplitude of AE signals changes largely, it indicates chipping or breaking of the insert tip. 2) It was confirmed that AE signal is highly sensitive to the cutting speed and tool wear. 3) At the early period of cutting, the wear were large and RMS value increased highly by the influence of minute chipping and cracking, etc. Therefore, the above situations should be considered for the time when the tool would be changed.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.284-289
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• 2002

In this paper, we develop a six-axes machining center tool(MCT) and CAD/CAM system based RAD Tool Program. The MCT consists of two mechanical parts, i.e., a X-Y-Z Cartesian coordinate typed MCT and a parallel-typed tilting table. Kinematics and singularity are accomplished to design the parallel-typed tilting table, and RAD Tool Program Is developed for the six-axes MCT, which requires the commands of position as well as orientation for machining of complex shape. In RAD Tool, the CAD/CAM system has a tool path generator, NC code generator and a graphic simulator. This paper designs the parallel-typed tilting table to meet the desired specification and presents the results of CAD/CAM system based RAD Tool Program.

• 한국생산제조학회지
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• 제8권5호
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• pp.96-101
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• 1999

This study suggests an algorithm for tooth profile generation of free from curve involute gear, a special gear of which the pitch line is a free curve instead of a circular one. For the first, a methodology for calculation of the tooth curve is developed and formulated Then the formulated algorithm, is programmed for manufacturing and verified by computer graphics. Next the calculated results as changed in to NC codes to apply to wire electric discharge machine(WEDM). Finally, the machined gear is examined in engagement with a standard involute gear.

• 한국생산제조학회지
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• 제4권3호
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• pp.58-66
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• 1995

It is very important to test motion accuracy and performance of NC machine tools as they affect that of all other machines machined by them in industry. In this paper, in has become possible to detect errors of linear displacement of radial direction for circular motion test using newly assembled magnetic type of linear scales so called Magnescale ball bar system, and to calculate time interval getting error motion data and revolution angle of circular motion in machining center using tick pulses come out from computer. And a set of error data gotten from test is expressed to a plot by computer treatment and to numerics of error motion by statistical treatment and results of test are compared with those of Renishaw ball bar system.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1997년도 추계학술대회 논문집
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• pp.31-36
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• 1997

Thermal expansion of the ball screw in semi-closed loop type CNC Lathe directly affects the position precision along the travel axis. In this paper, the thermal displacement of the ball screw is estimated by using macro variables. The estimated displacements of the ball screw are managed by calculating the interval of pitch error rate in the NC. The thermal behaviour of the ball screw of the CNC Lathe, under the constant operating conditions, was measured to examine the effectiveness of this compensation method. The results showed that thermal displacement of the ball screw could be maintained its accuracy better than 6${\mu}{\textrm}{m}$ while applying this method.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.370-375
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• 2004

This paper presents an accurate cutting simulation and feedrate scheduling system for CNC machining. This system is composed of a cutting simulation part and a feedrate scheduling part. The cutting simulation part computes the geometric informations and calculates the cutting forces in CNC machining. The cutting force model using cutting-condition-independent coefficients was introduced for flat end milling and ball end milling. The feedrate scheduling part divides original blocks of NC code into smaller ones with optimized feedrates to adjust the peak value of cutting forces to reference forces. Some machining examples show that the developed system can control the cutting force at desired levels.

• 기계저널
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• 제20권1호
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• pp.31-39
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• 1980

Automation(자동화)은 1946년 Ford 자동차회사에서 출생한 이래 반도체공업의 기술정보를 배 경으로 한 Computer, NC, Digital 정보처리기술, 도형정보처리기술등의 개발로 급격히 발전하 였다. 1970년대에 접어들면서 공업계기의 발달로 계장 system의 Hardware가 성능이나 신뢰성이 실용화레벨에 올라서 Roqort, 인공화능, man-machine system까지도 나타나게 되었다. 생산 system의 자동화에 있어서도 생산공정의 소재관리, 기계가공, 조립, 검사, 포장등을 일관서있는 연속작업이 되도록하는 종래의 Machanical Automation이 있다. 이는 소품종 다량생산체제에서 고능율, 고도의 가공효율의 요구에 따라 제품의 품질관리 및 제조를 자동전용기에 의한 양산체 제라 하겠는데 이것이 선진국의 1950년대의 자동화의 형태라 할수 있다. 1960년대에 들어서 앞서 기술한 전기 전자 기술의 발달과 제품에 대한 사회의 요구와 그것에 부응하기 위하여서는 생산 Line의 자동화가 점차 지능화하는 경향을 보이고 있으며 이를 Mechatronical Automation이라 부르기도 하나 이 점이 종래의 자동화와 성격이 다르다고 하겠다. 여기서는 생산시스템의 자동 화에 대한 새로운 경향이 어떠한 것이며 또 앞으로의 전망등을 살펴보기로 한다.

• 동력기계공학회지
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• 제3권4호
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• pp.63-68
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• 1999

The determination of the optimal machining parameters in metal cutting, such as cutting speed, feed rate, and depth of cut, is an important aspect in an economic manufacturing process. The main objective in general is either to minimize the production cost or to maximize the production rate. Also there are constraints on all the machining operations which put restrictions on the choice of the machining parameters. In this paper as an objective function the production cost is considered with two constraints, surface finish and cutting power. Genetic Algorithm is applied to determine the optimum machining parameters, and the effectiveness of the applied algorithm is demonstrated by means of an example, turning operation.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1993년도 추계학술대회 논문집
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• pp.389-394
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• 1993

Die making process is classified into design,manufacturing,polishing,assembly, and performance test. Die polishing is not a machining process by cutting edge of tool, but it is finishing by relative cutting movement under the surface contact between grinding particles and workpiece, and this process comprised 30~40% of total manufacturing hours. However, die polishing process is still performed by the skilled workers. Now a days, it is very difficult to secure skilled workers due to the hardworking environment and this situation will be getting worse in the future which has great difficulty of dies and molds industries.This process has the common problem on the elimination of tedious manual polishing among the tool making industries. Therefore this study is aimed at the development of an automatic polishing attachment which could be attached onthe spindle of CNC machine tool and controlled by the NC program data created by CAD/CAM system. As a result, this study will contribute the realization of automatic fine polishing process and improvement of quality level of dies and molds.