• Title/Summary/Keyword: Drill diameter

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Development of Electrode Guide of Super-drill EDM and Electrical Discharge Machining of Small Hole for High Precision Semiconductor Die (초정밀 반도체 금형 제작을 위한 슈퍼드릴 방전가공기 전극가이드 개발과 미세홀 방전가공)

  • Park, Chan-Hae;Kim, Jong-Up;Wang, Duck-Hyun;Kim, Won-Il
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.4 no.3
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    • pp.32-38
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    • 2005
  • Electrical discharge machining is the method of using thermal energy by electrical discharge. Generally, if the material of workpiece has conductivity even though very hard materials and complicated shape which are difficult to cut such as quenching steel, cemented carbide, diamond and conductive ceramics, the EDM process is favorable one of possible machining processes. But, the process is necessarily required of finish cut and heat treatment because of slow cutting speed, no mirror surface, brittleness and crack due to the residual stress for manufactured goods. In this experimental thesis, the super EDM drilling was developed for high precision semiconductor die steel and for minimization of leadframe width. It was possible to development of EDM drilling machine for high precision semiconductor die with the electrode guide and its modelling and stress analysis. The development of electrode with the copper pipe type was conducted to drill the hole from the diameter of 0.1mm to 3.0mm with the error of from 0.02mm to 0.12mm. From the SEM and EDX analysis, the entrance of the EDM drill was found the resolidification of not only the component of tungsten but also the component of copper.

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Estimation of Lower Jaw Density using CT data

  • Jargalsaikhan, Ariunbold;Sengee, Nyamlkhagva;Telue, Berekjan;Ochirkhvv, Sambuu
    • Journal of Multimedia Information System
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    • v.6 no.2
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    • pp.67-74
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    • 2019
  • Bone density is one of the factors in the early failure of dental implants and doctors should make a preoperative assessment of jaw bone density using patient's CT data before dental implant surgery in order to find out whether the patient has osteoporosis and osteopenia. The main goal of this study was to propose a method that based on image processing techniques in order to provide accurate information about where to drill and place an abutment screw of implants in the jaw bone for doctors and reduce human activity for the estimation of the local cancellous bone density of mandible using CT data. The experiment was performed on a computed tomography data of the jaw bone of two different individuals. We assumed that the result of the estimation of jaw bone density depends on the angle of drilling and average HU (Hounsfield Unit) values were used to evaluate the quality of local cancellous bone density of mandible. As a result of this study, we have been developed a toolbox that can be used to estimate jaw bone density automatically and found a positive correlation between the angle of the drill and time complexity but a negative correlation between the diameter of the drill and time complexity.

Stabilization of the Drilling Process through Active Torque Control (능동적 토크제어를 통한 드릴공정의 안정화)

  • 김중배;이상조
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.9
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    • pp.2234-2241
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    • 1993
  • The torque variation in drilling process represents the problems of the efficient and stable machining. In order to cope with them, the active control method is adopted to drill the workpiece under the constant cutting torque though the cutting stiffness of the workpiece or the diameter of the drill bit changes. The cutting process is modeled in the geometric viewpoint related with the feed and the number of cutting lips. And the dynamic model is approximated to the first order system for the purpose of control. The adaptive PI control is used in computer simulations and experiments. The results of the study show the validity of the drilling method with torque control.

A Study on the Drilling Characteristics of a TiAlN Coated Twist Drill (TiAlN 코팅드릴의 구멍가공특성에 관한 연구)

  • Kim, Tae-Young;Shin, Hyung-Gon;Kim, Jong-Taek;Kim, Min-Ho;Lee, Han-Gyo
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.3 no.4
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    • pp.29-36
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    • 2004
  • An experimental study on drilling of stainless steel is conducted using TiAlN coated drills and HSS twist drills with several cutting conditions; feed rate, spindle rotational speed, and dry/wet cutting. The effects of number of hole on the thrust force are examined by cutting force measurement. The flank wear of the drills and the change of hole diameter are quantitatively observed using a vision system. It is found that the thrust force in drilling with TiAlN coated drills decrease under dry and wet machining, whereas the flank wear resistance is improved.

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Effect of Geometrical Similarity between Twist Drill on the Shape of Chip Produced (드릴의 기하학적 상사성이 칩형상에 미치는 영향)

  • 최만성
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1999.10a
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    • pp.513-518
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    • 1999
  • In this study, geometrical similarity conditions for drills of various diameters are discussed. The effect of geometrical similarity on the chip shape and forces of different sized conventional drills has been experimentally confirmed. Drilling tests are carried out for SM45C by using the conventional HSS drills. The torque and thrust forces are measured and compared with those chip forms. Chip shape in drilling are affected by three factors being flow angle, side and up curl of the chip. It is found that the feedrate and drill diameter are more affected than cutting speed on the chip form and cutting forces. The similarity conditions gives easily to estimate the chip shape, the thrust and the torque for drills of different diameters.

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A Study On the Machinability of Steels by Drilling (드릴가공에서 강재의 피삭성에 관한 연구)

  • 김남훈
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.5 no.4
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    • pp.98-107
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    • 1996
  • In order to predict analytically torque, thrust force, tool life and chip formation in drilling, cutting models for chisel edge with various tool-chip contact length were developed in this type. Also, the experimental tests are run with various pilot holes. The following conclusions were obtained from the analysis. \circled1 It's also found experimentally that thrust force(Fz) decreases as pilot hole diameter increases. \circled2 Surface roughness for material(G) is larger that for material(J). The difference over two materials in roughness value about 0.5$mu extrm{m}$. \circled3 Flank wear of the drill in cutting material of G less than any other kinds of materials(F, G, H, I, J). \circled4 In drilling a deep hole on a workpiece over SM45C either twist drill. The chip was conical helix type at the fist suspensely change the two segment type and than two a long pitch helix style.

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Effect of Geometrical Similarity between Twist Drill on the Shape of Chip Produced. (드릴구멍 상사성이 칩형상에 미치는 영향)

  • 최만성
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.9 no.6
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    • pp.118-126
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    • 2000
  • In this study, geometrical similarity conditions for drills of various diameters are discussed. The effect of geometrical similarity on the chip shape and forces of different sized conventional drills has been experimentally confirmed. Drilling tests are carried out for SM45C by using the conventional HSS drills. The torque and thrust forces are measured and compared with those chip forms. Chip shape in drilling are affected by three factors being flow angle, side and up curl of the chip. It is found that the feedrate and drill diameter are more affected than cutting speed on the chip form and cutting forces. The similarity conditions gives easily to estimate the chip shape, the thrust and the torque for drills of different diameters.

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A Study on the Characteristics of BTA Deep Drilling for Marine Part Carbon and Alloy Steels

  • Sim, Sung-Bo;Kim, Chi-Ok
    • International Journal of Ocean Engineering and Technology Speciallssue:Selected Papers
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    • v.3 no.1
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    • pp.40-48
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    • 2000
  • The term "deep holes" is used to describe the machining of holes with a relatively large length to diameter ratio. The main feature of BTA deep hole drilling is the stabilization of cutting force necessary for the self guidance of the drill head. An additional feature is the cutting tool edges that are unsymmetrically placed on the drill head. There is an increasing necessity to predict the hole geometry and other dynamic stability behavior of deep hole drilling guidance. In this study, the effects of BTA deep hole drilling conditions on the hole profile machined piece are analyzed using domain analysis technique. The profile of deep hole drilled work piece is related to cutting speed, feed rate, chip flow, tool wear, and so on. This study deals with the experimental results obtained during the BTA drilling on SM45C, SM55C carbon steels and SCM440 steels under various cutting conditions, and these results are compared with analytical evaluations.aluations.

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A Study on Cutting Conditions of the Be-Cu Material in Micro Deep Hole Drilling Operation (미세심공드릴 가공에 있어서 Be-Cu 재료의 절삭조건에 관한 연구)

  • 김희남;유숙철;이형원;이원영;이종화;이인수
    • Journal of the Korea Safety Management & Science
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    • v.2 no.2
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    • pp.117-126
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    • 2000
  • Recently micro deep hole drilling is required in the whole industry. However, micro deep hole drilling has still much difficulty because of the lack of drill rigidity and the interruption of chip. We treated a micro deep hole(diameter 0.35mm, depth 3mm) used in a connector jack pin. Therefore, a surface roughness is very important. In this paper, we studied on the variation of the surface roughness for cutting conditions during micro deep hole drilling of Be-Cu material. Most of all, we tried to drill on CNC for the realization of automatization.

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A Study on the Fabrication and Evaluation of Burnishing Drills for Aluminum Hole Making (알루미늄 홀 가공용 버니싱 드릴의 제작 및 평가에 관한 연구)

  • Ha, Jeong-Ho;Kim, Dong-Gyu;Sa, Min-Woo
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.21 no.7
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    • pp.53-63
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    • 2022
  • Recently, the use of aluminum components in the reduction of the vehicle weight to improve fuel efficiency and reduce carbon dioxide emissions has increased. In the aluminum machining cutting process, hole-making is an important process that accounts for 30% of the machining process. Although many studies have been conducted using the continuously advancing hole processing technology, studies on the machinability of the tool depending on the type of chuck on the workpiece are still lacking. In this study, the machining performance of cemented carbide burnishing drills was compared and analyzed according to chuck type. The burnishing drill was used to create a hole in the AL6061 workpiece, and the surface roughness and dimensional accuracy of the hole were examined according to the type of chuck while monitoring the spindle load.