• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2001년도 춘계학술대회 논문집
• /
• pp.1105-1108
• /
• 2001

In these days, according s the increase of technological development the part demension goes up for ultra-precision. It is grinding behavior that is important processing which directly influences by machining accuracy at product quality with the net shape manufacturing. In this study, by using CBN wheel an analysis carried out for workpiece's profiles and its characteristics by measuring grinding force and surface roughness. Workpiece materials were used STD11, SUS304 and STB2 varing condition of feedrate and depth of cut.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1997년도 추계학술대회 논문집
• /
• pp.870-874
• /
• 1997

Super-abrasives such as diamond and CBN have used to maintain accuracy and form deviation for superalloy etc. This study contains the dry cylindrical grinding of metals with resinoid-bond CBN wheel. For various conditions of grinding speed, workpiece speed, grinding depth and feed speed of table, the grinding resistance and the surface roughness are measured and discussed. The results are as follows.

• 한국기계가공학회지
• /
• 제7권4호
• /
• pp.142-148
• /
• 2008

This study aims to find the optimal cutting conditions, which are obtained by grinding condition, and the grinding characteristics and condition of constant velocity joint were investigated with respect to wheel velocity, depth of cut, feed speed. Grinding machine has been widely used in manufacturing optical reflects of metal. Such as steel are easy to be machined because of their proper material. As a result I obtained the data of grinding conditions makes good surface roughness and the optimal condition of grinding and get the mesh condition. The purpose of this study is to find the optimum grinding wheel characteristics for cutting constant velocity joint.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 1995년도 춘계학술대회 논문집
• /
• pp.70-80
• /
• 1995

광학용 정밀유리와 건축용 패널유리 전문가공을 위한 CNC Glass Scribing Machine 을 개발하였다. 이제까지는 고품질의 고가기계를 수입하여 사용하던가 간이 자동화된 자체 개발기계를 사용하여 여유있게 절단한후 연삭가공에서 정밀칫수를 맞추는 작업을 해왔었다. 그러나 금번 개발된 기계를 사용하여 작업한 결과 연삭공정을 생략할수 있음은 물론 가공칫 수 정밀도도 일급 수준을 얻을수 있었다. 그러나 아직 세계일류의 품질과 성능은 도달치 못 했다. 생산성 향상을 위한 이송속도 향상설계와 가공칫수 정밀도의 초일급 달성을 위한 초 정밀설계를 통해 품질과 성능에서 세계일류의 상품화 개발과정을 준비중에 있다. 본논문에 서는 본 기계의 개발과정 및 주요요소기술들과 개발 결과를 정리하였다.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1995년도 추계학술대회 논문집
• /
• pp.28-32
• /
• 1995

Bacause the chatter vibration is a main factor to damage on the quality and integrity, The cure is required peticurity in cykinderical plunge grinding. The chatter vibration relatied with wheel speed, workpiece and infeed rate. Therefore, we expressed more credible normal signal and chatter signal Pattern in accrdiance with wheel speed and acquired RMS signal of the accelerrometer. In thos study, after finding the chatter pattern, we applied two parameters, standard deviation and Kurtosis, to Neural Network.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1997년도 춘계학술대회 논문집
• /
• pp.977-981
• /
• 1997

Because the chatter vibration is a main factor to damage on the quality, The cure is require peticually in cylinderical plunge grinding. The chatter vibration is with wheel speed, workpiece speed and infreed rate. Therefore, in this study, we expressed more credible chatter frequency in accordiance with wheel speed by FFT after accereleration sensing.

• 대한기계학회논문집
• /
• 제12권5호
• /
• pp.1055-1062
• /
• 1988

본 연구에서는 역학모델을 이용해 공구마멸 특성을 절삭속뿐만 아니라 공구와 유리섬유의 접촉길이에 대해서도 논하고, 이 결과와 실험결과를 대비 검토하였다. 또 몇 가지 공구재종으로 절삭성능을 측정하였다.

• Tribology and Lubricants
• /
• 제34권2호
• /
• pp.49-54
• /
• 2018

Hydraulic reciprocating seal has been widely used to prevent fluid leakage in hydraulic systems. Also, hydraulic reciprocating seal plays a significant role to provide lubricant film at contacting interface to minimize tribological problems due to sliding with counter material. To predict lifetime of hydraulic reciprocating seal, quantitative understanding of wear characteristics with respect to operating conditions such as normal force and sliding speed is needed. In this work, effect of sliding speed on wear of polyurethane (PU) hydraulic reciprocating seal were experimentally investigated using a pin-on-disk tribo-tester. The wear characteristics of PU specimens were quantitatively determined by comparing the confocal microscope data before and after test. It was found that the wear rate of PU specimens decreased from $4.9{\times}10^{-11}mm^3$ to $1.1{\times}10^{-11}mm^3/Nm$ as sliding speed increased from 120 mm/s to 940 mm/s. Also, it was observed that the friction decreased slightly as the sliding speed increased. Improvement of lubrication state with increasing sliding speed was likely to be responsible for this enhanced friction and wear characteristics. This result also suggests that decrease in sliding distance between PU elastomer and counter materials at lower sliding speed is preferred. Furthermore, the quantitative assessment of wear characteristics of PU specimen may be useful in prediction of lifetime of PU hydraulic reciprocating seal if the allowed degree of wear for failure of the seal is provided.

• 한국공작기계학회논문집
• /
• 제15권5호
• /
• pp.44-50
• /
• 2006

Cam mechanisms are one of the most popular devices for generating irregular motion and are widely used in many automatic equipments, such as textile machinery, internal combustion engines and other automatic devices. In order to obtain the positive motion of follower by rotating cam, its shape should be correctly designed and manufactured. In present paper, a CAD/CAM system is developed for shape design of disk cams using relative velocity method and NC code generation using the biarc curve interpolation. And, a disk cam is successfully manufactured by the developed CAD/CAM system. Thus, it is shown that the developed CAD/CAM system can be used for high precision cam profile CNC grinding machine.

• 한국정밀공학회지
• /
• 제10권1호
• /
• pp.9-13
• /
• 1993

Micro-electronics를 핵으로 하는 기술혁신의 물결이 눈부시고, 우리 주변의 일상생활이 하루가 다르게 변해 가고 있다. Leading-edge technology, high technology, advanced technology 등으로 호칭되는 일군의 새로운 기술의 절대적 level이 현재 어디에 위치해 있는지 확인 조차 하기 어렵고 첨단기술 제품의 성능에 넋을 잃을 지경이 지만 고려청자나 이조백자에 대해서는 현재의 기술을 가지고도 그 재현이 곤란하다. 이와 같이 시차의 이중성 속에서 제품의 부가가치를 높이고 생산성을 올리기 위해서는 가공기술의 고도화를 가하지 않으면 안된다. 어떤 소재를 설계된 모양대로 변화시키는 일련의 과정을 가공이라 한다면 이에는 변형가공(주조, 소성가공), 부가가공(용접), 제거가공(절삭, 연삭)등을 생각할 수 있으며 이들 사이의 가공정도의 개략치는 다음과 같다. (그림.1 가공공정에 따른 가공정도) 공작물에 요구되는 가공정도는 시대의 변천과 더불어 level up되고 이를 위한 기술 개발이 부단히 이어오고 있다. 1960-70 년대의 생산가공 기술은 .mu. m 단위인 $10^{-5}$--$10^{-6}$m의 범위의 가공정도를 생산 line으로 실현하는 것이 중점 개발 목표였다. 그러나, 현재는 $10^{-5}$--$10^{-7}$m를 목표로 한 submicron 가공정도 실용기에 들어서고 있다.