• 산업경영시스템학회지
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• 제24권69호
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• pp.65-73
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• 2001

The objective of this study is to evaluate the vibration attenuation effects of the different type of gloves and drilling mode while operating a light-weighted powered hand drill. For the experimental design, five different kinds of glove(barehanded cotton partly coated anti-vibration, and open-finger vibration glove) two types of push force level(100N and 200N) and two types of drilling mode(impact and non-impulsive) were considered. Six healthy male subjects were employed to drive screws into a vertically mounted marble plate with a powered hand drill in a randomly ordered experimental conditions. The findings of this study are summarized as follows; (1) It was found that the best combination of overall BMS transmissibility was using impact drilling mode with anti-vibration glove among evaluated experimental conditions (2) The wearing open finger vibration glove in mid-frequency level and anti-vibration glove with impact drill in high-frequency were the best in the result from mean corrected transmissibility equation of ISO 10819.

• 대한기계학회논문집 C: 기술과 교육
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• 제1권1호
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• pp.39-47
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• 2013

탑 드라이브 장비는 드릴 비트에 회전력을 전달하여 굴착을 하게하는 장치이며, 1983년 Derrick Drilling Machine의 Kelly Rotary Table로 시작하여, 1984년에 DDM 650 DC가 등장함으로써 본격적으로 개발 되기 시작했다. 이러한 탑 드라이브 장비는 미국의 N사와 노르웨이 A사가 전 세계 시장의 90% 이상을 점유하고 있으며, 이로 인하여 탑 드라이브 장비의 세계시장 진입과 장비에 대한 정보가 제한적일 수 밖에 없다. 따라서 본 논문에서는 제한된 정보를 통하여 신뢰성을 가지는 제품을 개발하기 위한 절차 및 방법에 대하여 소개하고자 한다. 설계 오류 및 신뢰성이 검증된 제품 디자인을 위하여 3D Tool을 사용하였으며, 이를 활용하여 설계오류, 간섭체크, 기능체크, 구조강도 해석 등을 수행하여 제품의 신뢰성을 사전 검증 하였다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
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• pp.185-189
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• 2001

In order to prevent the production defects the optimum design of product, jig and fixture putting in the field is very significant manufacturing method. Drilling Jig is the device according to industrial demand for multi manufacturing products on the growing at alarming rate. In the field of design and making for machine tool working, welding, assembling with jig and fixture for mass production is a specific division. They require analysis of many kinds of important factors, theory and practice of machine tool operating process and jig & fixture structure, machining condition for tool making, tool materials, heat treatment of jig & fixture components, know-how and so on. In this study we designed and constructed a drilling jig of mass production and performed tryout under the Auto CAD, Auto Lisp database, that we made by database, and window environment. Especially this study is reveals with the analysis of part drawing, jig planning, jig design etc, and then the result of drill jig's making try out.

• 한국초지조사료학회지
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• 제22권3호
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• pp.221-226
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• 2002

이탈리안 라이그라스의 생육특성 및 종자 생산성을 조사하기 위하여 축산기술연구소 초지 사료과 시험포장에서 2000년부터 2001년까지 실시하였다. 시험구 배치는 휴폭(15, 30, 45cm) 및 이른 봄 질소시용량(50, 75, 100kg/㏊)을 조합한 분할 구배치 3반복으로 설계되었다. 생육특성 중에서 도복저항성은 휴폭이 45cm로 넓고 이른 봄 질소시용량이 50kg/㏊로 적을 때 높게 나타났고, 줄기의 수는 휴폭이 45cm 보다는 15 또는 30cm에서 많은 경향이었으며, 나머지 생육특성은 비슷하였다. 종자수량 구성요소에 있어서 단위면적당 이삭 수는 휴폭이 좁음에 따라서 많은 경향이었으나, 이삭의 길이와 1000립중은 휴폭이 넓음에 따라서 보다 길고 무거운 경향이었으며, 등숙율은 휴폭 30cm와 질소비료 50kg/㏊ 조합에서 가장 높았다. 또한 종자 수량은 휴폭 30cm와 이른 봄 질소시용량 50kg/㏊ 조합에서 가장 높은 수량을 나타내었다.

• 한국구조물진단유지관리공학회 논문집
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• 제27권1호
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• pp.64-70
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• 2023

본 연구에서는 1.04배 드릴비트 직경 및 1.02배 드릴비트 직경 시 앵커의 신뢰성시험을 수행하였다. 각 변수별 시험을 통해 앵커의 표준편차 및 변동계수를 검토하였고, 기준시험 결과와 비교 평가하였다. 1.04배 드릴비트 직경을 가진 M12 및 M16 앵커의 신뢰성시험결과, 극한 인장하중 허용기준 변동계수 값인 20% 이내의 값을 나타내어 시험기준을 만족하였다. 또한, 1.04배 드릴비트 직경을 가진 앵커의 성능은 기준시험 대비 M12 앵커는 약 74%, M16 앵커는 약 55% 정도로 나타나 앵커의 내력이 다소 부족한 성능을 나타냈지만, 설계강도 대비 약 253% 및 210%로 나타나 1.04배 드릴비트 직경에 설치된 앵커의 인발성능은 충분히 확보하고 있음을 알 수 있었다. 1.02배 드릴비트 직경을 가진 M12 및 M16 앵커의 신뢰성시험결과, 극한인장하중 허용기준 변동계수 값인 20% 이내의 값을 나타내어 시험기준을 만족하였다. 또한, 1.02배 드릴비트 직경을 가진 앵커의 성능은 기준시험 대비 M12 앵커는 약 48%, M16 앵커는 약 53% 정도로 나타나 다소 부족한 성능을 나타냈지만, 설계강도 대비 약 136% 및 168% 로 나타나 1.02배 드릴비트 직경에 설치된 앵커의 인발성능은 충분히 확보하고 있음을 알 수 있었다.

• The Journal of Advanced Prosthodontics
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• 제8권3호
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• pp.207-213
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• 2016

PURPOSE. A recently introduced direct drill-guiding implant surgery system features minimal tolerance of surgical instruments in the metal sleeve by using shank-modified drills and a sleeve-incorporated stereolithographic guide template. The purpose of this study was to evaluate the accuracy of this new guided surgery system in partially edentulous patients using geometric analyses. MATERIALS AND METHODS. For the study, 21 implants were placed in 11 consecutive patients using the direct drill-guiding implant surgery system. The stereolithographic surgical guide was fabricated using cone-beam computed tomography, digital scanning, computer-aided design and computer-assisted manufacturing, and additive manufacturing processes. After surgery, the positional and angular deviations between planned and placed implants were measured at the abutment level using implant-planning software. The Kruskal-Wallis test and Mann-Whitney U test were used to compare the deviations (${\alpha}=.05$). RESULTS. The mean horizontal deviations were 0.593 mm (SD 0.238) mesiodistally and 0.691 mm (SD 0.344) buccolingually. The mean vertical deviation was 0.925 mm (SD 0.376) occlusogingivally. The vertical deviation was significantly larger than the horizontal deviation (P=.018). The mean angular deviation was 2.024 degrees (SD 0.942) mesiodistally and 2.390 degrees (SD 1.142) buccolingually. CONCLUSION. The direct drill-guiding implant surgery system demonstrates high accuracy in placing implants. Use of the drill shank as the guiding component is an effective way for reducing tolerance.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.993-998
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• 2002

watches, air bearings and printed circuit hoards (PCB). However, it is not easy to determine optimum cutting conditions since the micro drilling process is very sensitive to various disturbances. Also, undesirable characteristics to optimize the micro drilling are small signal-to-noise ratios, drill wandering motions and high aspect ratios. Thus, in this study, experimental design methods are applied to determine optimum cutting conditions. Suing the methods, three cutting parameters, fred, step and curving speed are optimized to minimize thrust forces. Obtained conditions are verified through required experimental works. As the results, it is shown that the experimental methods can be applied to micro drilling processes to determine Optimum Cutting Conditions.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.513-518
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• 2001

As the machining depth increases, the drilling torque increases and fluctuates and the risk of drill failure also increases. Hence, drilling torque control is very important to prevent the drill from failure. In this study, a PID controller was designed to control the drilling torque in a machining center. The plant including the feed drive system, cutting process, and spindle system was modeled for controller design. The Ziegler-Nichols rule was used to determine the controller gain and control action times. The root locus plot was used to tune the controller gain for a certain cutting condition. Also, suggested was a simple method to obtain the tuned controller gain for an arbitrary cutting condition not using the Ziegler-Nichols rule and root locus plot. The cutting torque control, performance of the designed controller and the effect of gain tuning on the control performance were examined.

• 한국기계가공학회지
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• 제12권2호
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• pp.75-80
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• 2013

Cathode is an essential component used in plasma etching process which is to make micro pattern on the silicon wafer. The currently used cathodes produce particles at the high temperature plasma etching process. To overcome this problem, a 'Silicon Only Cathode' was developed. This 'Silicon Only Cathode' requires manufacturing process changes due to the change of shapes, material features, and machining characteristics of work materials. This research investigates the small hole drilling process. The conclusion is that PCD drills with twist angles of $20^{\circ}$ and $25^{\circ}$ were tested for small hole drilling and the experimental results indicate that the drill with $25^{\circ}$ twist angle drill causes less thrust force.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.385-386
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• 2013