• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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• pp.417-422
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• 2000

In the process of die manufacturing, according to increasing demand of die and molds, the efficient machining of dies and molds has been increased. However, while the cutting process has been automated by the progress of CNC(computer numerical control) and CAD/CAM, the polishing process still depends on the experienced knowledge of an expert. Also, even when workers are skilled in polishing dies. it takes much time to obtain the required roughness and smoothness on the surface of a die. Moreover, many workers gradually avoid doing polishing work because of the poor working conditions caused by dust and noise. Therefore, to improve productivity and to solve the potential shortage of skilled workers, a user-friendly automatic polishing system was developed in this research. The developed polishing system with five degrees of freedom is able to keep the polishing tool normal to the die surface during operation and is able to maintain a pressure constantly by the developed pneumatic system. Also, to evaluate polishing performance of the developend system and find the polishing conditions, the various polishing experiments were carried out.

• 한국정밀공학회지
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• 제19권1호
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• pp.99-106
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• 2002

For the development of a ultra-precision CNC polishing system including on-machine measurement system, we study a corrective polishing algorithm. We calculated unit removal profiles for various flat type polishing tools and polishing tool positions. Using these results we simulate the corrective polishing process based on dwell time control. We calculate dwell time distributions and residual error of the polishing simulation method and the FFT calculation method. We test corrective polishing algorithm with an optical glass. The target removal shape is a sine wave that has amplitude 0.3 micro meters. We find this polishing process has a machining resolution of nanometer order and is effective for sub-micrometer order machining. This result will be used for the software development of the CNC polishing system.

• 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.

• 한국정밀공학회지
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• 제17권4호
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• pp.69-80
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• 2000

Generally, die polishing is a lime consuming process, resulting in 30∼50％ of the whole die manufacturing time. However, die polishing has not been automated yet, since it needs a great deal of experience and skill. This paper describes a new development of automated system for die polishing and focuses on the successful achievements of the element techniques to realize from hand skill to automation, as followings: (1) The 5 axes polishing system by the aid of robot with 2 degrees of freedom, is developed for the application of curved surface die. (2) The CAM system realizes a 5 axes tool path control for polishing and measuring. (3) The conductive elastic tool is able to meet curved surfaces of die and gives a high efficient and quality polishing characteristics. (4) The surface roughness measurement device with noncontact laser is developed and has a high reliability without surface damage.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.3-8
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• 2002

An intelligent polishing robot automation system is developed. Automatic Tool Change System(A.T.C.), Tool Posture Angle Control, and Robot Program for Polishing Application are developed and integrated into a robotic system that consists of a robot, pneumatic finding tool, and finding abrasives (papers and special films). A.T.C. is specifically designed to exchange whole grinding tool set for complete unmanned operation. Tool Posture Angle Control is developed to give a certain skew angle rather than right angle to tools on the surface for best finishing results. A.T.C. and Tool Posture Angle Control is controlled by a PC and the robot controller. Also, there have been some considerations on enhancing the performance of the system. Some elastic material is inserted between the grinding pad and the holder for better grinding contact. The robot path data is generated automatically from the NC data of previous machining process.

• 한국광학회지
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• 제19권6호
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• pp.422-428
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• 2008

본 논문에서는 툴 영향 함수(Tool Influence Function)를 이용한 피치(pitch)툴의 정량적 물질 제거 제어 기법에 대하여 기술하였다. 피치 툴은 뛰어난 표면 거칠기를 생성시키는 반면 툴의 물질 변형이 상대적으로 크고 물질제거가 어렵기 때문에 일반적으로 숙련된 가공 기술자에 의한 정성적 연마 기법으로 간주되었다. 하지만 이러한 피치 툴을 이용한 수치모사 및 실험을 수행한 결과, 정량적 피치 툴 연마 기법이 가능하다는 것을 알 수 있었다. 실험과 수치모사에 의한 물질 제거 형상은 약 79%의 정확도로 일치하였다. 또한 직경 280 mm의 평면가공에 대한 수치모사 단계에서 5번의 모의 가공 후 p-v(peak to valley) $1{\mu}m$의 최초 형상오차를 168 nm까지 낮추는 결과를 얻을 수 있었다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
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• pp.327-331
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• 2001

In the process of optical parts machining, polishing has been applied. Traditional polishing process is suitable for spherical optical parts. But it is very difficult to apply traditional process for aspheric optical parts. Nowadays, as growing needs for aspherical optic parts, many researches have been conducted. In this study, we developed computer controlled polishing system which consists of three major parts of active pressure control for correcting polishing process, mechanical on-machine measurement for rough polishing, and optical on-machine measurement for finish polishing, respectively. In this paper, a systematic stretegy for correcting polishing process, pressure control scheme for polishing tool, and on-machine measurement methods for automated and precise polishing are suggested. The information about developed machine is also included.

• 한국정밀공학회지
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• 제25권2호
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• pp.28-34
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• 2008

Recently, with the development of high speed machining technology for difficult-cutting materials, to improve the cutting performance of cutting tool, fine surface finish of complex shape tools using magnetic polishing technology is in high demand. This study is, therefore, discussed and compared the cutting characteristics of polished tools by the adopted various magnetic polishing moving types a point of view the cutting forces and the tool life. Moreover, the practicality of magnetic polished tools in the wide range cutting conditions is investigated. From obtained results, It is confirmed that the CW(clockwise) revolution and oscillation type as the polishing moving type is proper and magnetic polished tool shows the excellence in high cutting speed range.

• 한국생산제조학회지
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• 제19권3호
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• pp.313-320
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• 2010

The magnetic abrasive polishing (MAP) process is used to achieve the nano-meter grade polishing results on flat or complicated surface. In previous study, polishing the stainless steel plate which is a non-magneto-material was tried. To polish non-magneto-materials using the MAP process was very difficult because the process was fundamentally possible by the help of a magnetic force. Therefore, it had lower efficiency than magneto-materials such as SM45C. In this study, optimization for tool geometry of the MAP was performed to improve the magnetic force between tool and workpiece. Moreover, a permanent magnet was installed below the non-magneto-material to improve the magnetic force. And then the design of experiments was carried out to evaluate the effect of the MAP parameters on the polishing results.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1998년도 제13차 학술회의논문집
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• pp.346-351
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• 1998

Cutting process has been automated due to progress of CNC and CAD/CAM, but polishing process has been only depended on experiential knowledge of expert. Polishing work for a curved surface die demands simple and repetitive operations but requires much time for its high precision. Therefore it is operated in the handiwork by skilled worker. However the workers intend to avoid gradually polishing work because of the poor environments such as dust and noise. In order to reduce the polishing time and solve the problem of shortage of skilled workers, it has been done some research for an automation of polishing. To automate the polishing process, a 2 axes polishing robot which is attached to a 3 axes machining center has been developed by our previous research. This automatic polishing robot is able to keep the polishing tool normal on the curved surface of die. Therefore its performance of polishing is improved because of always keeping the tool normal on the surface. In this paper, the smaller sized polishing robot is developed to improve polishing performance. And the controller for 2 axes polishing robot is developed. The controller is composed of TMS320C31 with high speed which is 40-ns instruction cycle time, RAM memory with 64K words, digital input with 64 bits, digital output with 32 bits, and D/A converter with 4 channels, which is 12 bits resolution. To evaluate polishing performance of this developed robot, polishing experiment for shadow mask was carried out.