볼엔드밀가공에 의한 구면형상의 가공특성

왕덕현,김원일,이윤경,Wang, Duck Hyun,Kim, Won Il,Lee, Yun Kyeong 한국기계가공학회 2002 한국기계가공학회지 Vol.1 No.1

Hemisphere shapes were machined for different tool paths and machining conditions with ball endmill cutters. It was also found out how feedrate affect the precision of the machining and also tried to study the most suitable feedrate in specific cutting condition. Tool deflection, cutting forces and shape accuracy were measured according to the inclination position of the sculptured surface. As the decreasing of inclination position angle, the tool deflection was increased due to the decreased cutting speed when the cutting edge is approaching toward the center. Tool deflection when upward cutting IS obtained less than that of downward cutting and down-milling in upward cutting showed the least tool deflection for the sculptured surface. For down-milling, the cutting resistance of the side wall direction is larger than that of feed direction. It was found that the tool deflection is getting better as tool path is going to far from the center for convex surface.

코팅공구에 의한 원형곡면 선삭가공시 절삭특성

왕덕현,김원일,엄필환,Wang, Duck Hyun,Kim, Won Il,Eom, Phil Hwan 한국기계가공학회 2003 한국기계가공학회지 Vol.2 No.1

The experimental study for turning circular free fanned surface with TiN coated insert tool was conducted for different cutting conditions such as cutting speed, feed rate and depth-of-cut. For the fluctuation of 1.0mm depth-of-cut, the characteristics for machined surface and tool wear were less influenced by the feed rate and cutting speed than those of higher depth of cut. The higher surface roughness and surface precision were obtained in lower cutting speed. For the fluctuation of 1.5mm depth-of-cut, the higher surface roughness was obtained for the case of the lower feed rate of 0.05-10mm/rev and the higher cutting speed of 80m/min. For the fluctuation of 2.0mm depth-of-cut, the surface roughness and surface precision were too worse to machine the specimen And the flank wear on the tool was increased rapidly rather than the crater wear.

전극선 성분 변화에 따른 냉간금형용강의 와이어방전가공 특성

왕덕현,정순성,Wang, Duck-Hyun,Jeong, Sun-Sung 한국기계가공학회 2003 한국기계가공학회지 Vol.2 No.2

In the experimental study, wire EDM was conducted for cold die steel by changing the Wire electrode, peak discharge current and number of finish cut. From the micro structure analysis of SEM photographs, the size of irregular welded and added component on the EDMed surface is decreasing and size of EDMed plane surface is increasing as the decreasing peak current and increasing number of finish cut. From the analysis of coating effect, Zn component is highly contained in Br and Zn Wire EDMed surface and copper component is highly contained in Br and Al wire EDMed surface. Hardness values are Increasing as the increasing peak current and decreasing the number of finish cut The value of hardness is decreasing as Cu, Al, Zn and Br wire electrode because of the residual austenite effect of solid solution copper on solidification, and finally EDMed surface has the highest hardness values for every wire electrode. Yield strength values becomes larger and bending strength values become smaller due to the increasing the hardness. These results are increased as increasing brittleness with hardness.

미세 볼엔드밀가공시 절삭력과 음향방출신호에 의한 공구 파손 검출 및 메커니즘

왕덕현,김원일,임정숙,Wang, Duck-Hyun,Kim, Won-Il,Lim, Jeong-Suk 한국기계가공학회 2004 한국기계가공학회지 Vol.3 No.3

A successful on-line monitoring system for conventional machining operations has the potential to reduce cost, guarantee consistency of product quality, improve productivity and provide a safer environment for the operator. In fine-shape machining, typical signs of tool problems such as vibration, noise, chip flow characteristics and visual signs are almost unnoticeable without the use of special equipment. These characteristics increase the importance of automatic monitoring in fine-shape machining, however, sensing and interpretation of signals ar more complex. In addition, the shafts of the mini-tools break before the typical extensive cutting edge of the tool gets damaged. In this study, the existence of a relationship between the characteristics of the cutting force and tool usage was investigated, and tool breakage detection algorithm by LabVIEW was developed and the following results are obtained. It was possible to use a relative error compare which mainly used in established experiment and investigated tool breakage detection algorithm in time domain which can detect AE and cutting force signals more effective and accurate.

적층구조 복합재료의 절삭면 형상에 관한 연구

왕덕현,Wang, Duck Hyun 한국정밀공학회 1995 한국정밀공학회지 Vol.12 No.12

Machined graphite/epoxy surfaces were studied by using SEM (Scanning Electron Microscopy), surface profilometry and its analysis to determine suitable surface describing parameters for machined unidirectional and multidirectional laminate composite. The surface roughness and profile are found to be highly depdndent on the fiber layup direction and the measurement direction. It was possible to machine 90 .deg. and -45 .deg. plies due to the adjacent plies, which were holding those plies. It was found that the microgeometrical variations in terms of roughness parameters $R_{a}$ without $D_{y}$(Maximum Damage Depth) region and $D_{y}$are better descriptors of the machined laminate composite surface than commonly used roughness parameters $R_{a}$and $R_{max}$ The characteristics of surface profiles in laminate composite are well represented in CPD (Cumulative Probability Distribution) plot and PPD (Percentage Probability Density) plot. Edge-trimmed multidirectional laminate surfaces are Gaussian and random for profiles measured along the tool movement direction, they are periodic and non-Gaussian in the direction perpendicular to the tool movement.t.ent.t.

쾌속조형기에 의한 기어식 주유장치의 개발

왕덕현(Duck Hyun Wang) 한국기계가공학회 2014 한국기계가공학회지 Vol.13 No.6

An automatic grease lubricator provides an adequate amount of fresh grease constantly to any type of rotating machine to minimize friction heat and reduce friction loss. This study seeks to develop an automatic grease lubricator by means of rapid prototyping with a gear-driven mechanism and a controlled operation time. The ultimate design is to lubricate an adequate amount of grease by a simple dip-switch clicking mechanism according to an advanced set cycle. The backlash of the gear was minimized to increase the power, and to increase the power of the mechanism, the binding frequency and the thickness of the coil were changed. To control the rotation cycles of the main shaft according to certain set numbers, different resistances and chips were used in the design of the circuit which controls the electrical signals via a pulse. A digital mock-up was analyzed and the rapid prototyping (RP) trial products were tested with a PCB circuit and grease. An evaluation of the outlet capacity of RP trial products was conducted, as the friction caused by the outlet on the wall surface was an important factor in the operation of the equipment. Finally, a finishing process was applied to decrease the roughness of a surface to a comparable level to test the performance of the product.

냉간금형용 합금강의 정밀입자가공에 의한 표면정밀도 향상

왕덕현(Duck-Hyun Wang),김원일(Won-Il Kim) 한국산업융합학회 2002 한국산업융합학회 논문집 Vol.5 No.4

Experimental study was conducted for lapping process after WEDMed specimen. In order to decide the lapping depth of the specimen, the number of the grain size was increased from 400,600 to 800 to obtain the better surface. Observation of scanning electron microscope, hardness test, su'rface roughness test and energy dispersive spectrum(EDS) analysis were used for this experimental study. From the comparison and analyses of the results of between the wire-cut electrical discharge machining and the lapping, the following results were obtained. The surface roughness after lapping was found to be improved as increasing the number of lapping process like 1st, 2nd, 3rd lapping and the number of grain size such as 400, 600, 800. The surface hardness after increasing the lapping depth of the specimen was slowly increased. It was found that after 3rd lapping process the hardness was reached the hardness of original base material. It was found that the small amount of coating components within 3% was remained after the 1st lapping process, compared to that approximately 16% after WEDM process

탄화규소/알루미늄 금속계 복합재료의 형상방전가공

왕덕현(Duck-Hyun Wang),이윤경(Yun-Kyung Lee),우정윤(Jeong-Yun Woo),허보영(Bo-Young Hur) 한국공작기계학회 1998 한국공작기계학회지 Vol.7 No.1

티타늄합금의 와이어 방전가공과 후처리 연삭가공 특성

왕덕현(Duck Hyun Wang),김원일(Won Il Kim),김종업(Jong Up Kim) 한국생산제조학회 2002 한국생산제조학회지 Vol.11 No.6

동전기적 가스발생방식의 자동윤활주유기 개발

왕덕현(Duck-Hyun Wang) 한국기계가공학회 2008 한국기계가공학회지 Vol.7 No.4

Automatic grease lubricator is an equipment that provides adequate amount of fresh grease constantly to the shaft and bearings of machines. It minimizes the friction heat and reduces the friction loss of machines to the least. This paper is developing an automatic grease lubricator using a mode of the gas generation type from galvanic electricity. The ultimate goal of this equipment is to lubricate an adequate amount of grease with galvanic corrosion. In an electrolyte, combining anode(Mo) with cathode(Zn) is pressing out hydrogen gas of an galvanic element with galvanic reaction. The characteristics of this method is continuous flowing small hydrogen gas and controling the usage of the amount of the generation of hydrogen gas. The exterior body of grease lubricator was analyzed by Digital Mock-up of CATIA V5 and finite element analysis. The maximum stress is distributed over the outlet part where the grease lubricator suddenly narrowly contracts. The outlet part is analyzed with different constructed angle due to the different loading and setting angles. Using the analyzed design, RP trial products were producted and tested.