• Title/Summary/Keyword: cutting torque

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Development of Micro-hole Drilling Machine and Assessment of cutting Performance (마이크로흘 드릴링 머신의 개발 및 절삭성능 평가)

  • 김민건;유병호
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.10 no.5
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    • pp.39-44
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    • 2001
  • In this paper, drill fred mechanism, cutting depth measuring device and sensing buzzer of drill contact were investigated in order to develop the micro-hole drilling machine. Also, measuring device of cutting resistance was developed in order to estimate cutting resistance from change of cutting condition. The results show that extremely-low fled rate(less then $17{\mu}m/S$${\mu}{\textrm}{m}$ /s) can be done and cutting depth can be measured by up to 1${\mu}{\textrm}{m}$ with developed drilling machine. Accordingly we could assemble a very cheap micro-hole drilling machine($\phi$ 0.05~0.5 mm). Also we got the some properties of cutting performance i.e. under the same condition, cutting torque decreases as increase of spindle speed and rapid fled of drill brings about the inferior cutting state under low spindle speed.

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Speed Sensorless Torque Monitoring On CNC Lathe Using Internet (인터넷을 이용한 CNC 선반의 속도 센서리스 토크감시)

  • 홍익준;권원태
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.10a
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    • pp.467-470
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    • 2002
  • Internet provides the useful method to monitor the current states of the machine tool no matter where a personnel is monitoring them. In this paper, a monitoring method of the torque of the machine tool's spindle induction motor using internet is suggested. The torque of vector controlled induction motor is estimated without speed measuring sensor. Only stator currents are measured to estimate the magnetizing current which is used to calculate flux linkage, rotor velocity and motor torque. Graphical programming is used to implement the suggested algorithm, to monitor the torque of an induction motor in real time and to make the estimated torque monitored on client computers. To solve the fluctuation problem of estimated torque caused from instantly varying rotating speed of an induction motor, the rotating speed is reconstructed based on the measured current signals. Mechanical part of the machine tool is also reconstructed using the data obtained from preliminary experiments. Torque of the spindle induction motor is well monitored on the client computers with 3% error range under various cutting conditions.

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A Study on the Stability of Torque for Compressing-Cutting Device of Nano Tube Manufacturing System Using DC Servo Motor (DC 서보모터를 이용한 나노튜브 제조용 압축-절단 장치의 토크 안전성에 관한 연구)

  • Choi, Kab-Yong;Oh, Tae-Il
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.12
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    • pp.5393-5397
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    • 2011
  • The compressing-cutting device is used for manufacturing nano tube. the purpose of this study is to design and manufacture the compressing-cutting device witch has safety and stable performance. The most important core technology, in nano tube manufacturing, is to seam the each end of tube with appropriate pressure and to cut it off into the two part safely not to leak injected medium. Since the compressing pressure and the cutoff speed make the quality of nano tube, they are very important. This study will show the processes of design and manufacturing of compressing-cutting device.

A Study on the Influence of Cutting Conditions on the Dynamic Component of Cutting Resistance(ll) (절삭저항의 동적성분에 미치는 절삭조건의 영향에 관한 연구(II))

  • Jeon, Eun-Chan
    • Journal of the Korean Society for Precision Engineering
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    • v.1 no.2
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    • pp.58-68
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    • 1984
  • In this study, the static and dynamic components of cutting resistance were measured with tool dynamometer (Swiss, pieso-electric type) when S45C, A1-alloy and brass were drilled under the some variable conditions. The results obtained are as follows; 1) The dynamic components of these cutting resistance are not related to the depth of drilled hole. 2) The static and dynamic components of cutting resistance are increased in accordance with the increase of feed and drill diameter. 3) The dynamic components of thrust force are increased in accordance with the increase of spindle speed. 4) The rate of the dynamic component to the static component is 0.3 .approx. 0.5 in torque, 0.1 .approx. 0.2 in thrust force. 5) The characteristic of the tool system is affected in dynamic component of cutting resistance, and the creasted frequency and amplitude of the chip are determined by the crilled materials. 6) The maximum amplitude of the dynamic component is increased proportionally in accordance with the feed rate and the spindle speed.

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Experimental and numerical FEM of woven GFRP composites during drilling

  • Abd-Elwahed, Mohamed S.;Khashaba, Usama A.;Ahmed, Khaled I.;Eltaher, Mohamed A.;Najjar, Ismael;Melaibari, Ammar;Abdraboh, Azza M.
    • Structural Engineering and Mechanics
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    • v.80 no.5
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    • pp.503-522
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    • 2021
  • This paper investigates experimentally and numerically the influence of drilling process on the mechanical and thermomechanical behaviors of woven glass fiber reinforced polymer (GFRP) composite plate. Through the experimental analysis, a CNC machine with cemented carbide drill (point angles 𝜙=118° and 6 mm diameter) was used to drill a woven GFRP laminated squared plate with a length of 36.6 mm and different thicknesses. A produced temperature during drilling "heat affected zone (HAZ)" was measured by two different procedures using thermal IR camera and thermocouples. A thrust force and cutting torque were measured by a Kistler 9272 dynamometer. The delamination factors were evaluated by the image processing technique. Finite element model (FEM) has been developed by using LS-Dyna to simulate the drilling processing and validate the thrust force and torque with those obtained by experimental technique. It is found that, the present finite element model has the capability to predict the force and torque efficiently at various drilling conditions. Numerical parametric analysis is presented to illustrate the influences of the speeding up, coefficient of friction, element type, and mass scaling effects on the calculated thrust force, torque and calculation's cost. It is found that, the cutting time can be adjusted by drilling parameters (feed, speed, and specimen thickness) to control the induced temperature and thus, the force, torque and delamination factor in drilling GFRP composites. The delamination of woven GFRP is accompanied with edge chipping, spalling, and uncut fibers.

A Study on Cutting Performance of the BTA Drilling (BTA드릴가공의 절삭성능에 관한 연구)

  • 장성규;김순경;전언찬
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.10
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    • pp.65-72
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    • 1998
  • The BTA drilling chip is better for deep hole drilling than other self-piloting with pad drilling chips because the large length to diameter ratio allows a unique cutting force dispersion and better supplies the high pressure fluid. Therefore the BTA is useful for many tasks, such as coolant hole drilling of large scale dies, as well as tube seat drilling, which is essential for the heat exchanger, and variable component drilling for automobiles. Deep hole drilling has several significant problems, such as hole deviation, hole over-size, circularity, straightness, and surface roughness. The reasons for these problems, which often result in quality short comings, are an alignment of the BTA drilling system and the unbalance of cutting force by work piece and tool shape. This paper analyzes the properties through an experiment which com¬pared single-edge BTA drills with multiple-edge BTA drills, as well as the shapes of the tools to cause an unbalance of cutting force, and its effect on the precision of the worked hole. Conclusions are as follows. 1) In SMSSC drilling, 60m/min of BTA with single and multi-edged tools proved the best cutting condition and the lowest wear character. 2) The roundness got a little worse as cutting speed was increased, but surface roughness was hot affected. 3) It was proved that the burnishing torque of both drills approached 26%. which is almost the same as the 24% insisted on by Griffiths, and the dispersion characteristic of the multi-edged BTA drill proved better than the single-edge BTA drill.

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In-Process Prediction of the Surface Error Using an Identification of Cutting Depths in End Milling (엔드밀 가공중 절입깊이의 실시간 추정을 이용한 가공오차 예측)

  • 최종근;양민양
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.2
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    • pp.114-123
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    • 1998
  • In the end milling process, the information of the surface errors plays an important role in adaptive control systems for precision machining. As the measuring accuracy of the surface errors directly matches the control's, it is an important factor for evaluating the performance of the system. In order to obtain the surface errors, the prediction using the cutting force, torque, motor power etc. is frequently practiced owing to the easiness in measurement. In the implementation of the prediction, the information on the cutting depths make it concrete and precise. Actually the axial depth of cut limits the range of the calculation. In general, it is not easy to know the cutting depths due to irregular shape of workpieces, inaccurate positioning of them on the table of machine tool, and machining error in the previous cutting. In addition to, even if cutting depths are informed, it is difficult to match the individual position of the cutter on the varying shape of the work material. This work suggests an algorithm estimating the cutting depths based on cutting force and makes it precise to predict the surface error. The proposed algorithm can be applied in more extensive cutting situations, such as presence of the tool wear, change of the work material hardness, etc.

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Heat Treatment of Stator Core in Permanent Magnet Type Motor for Reduction of Friction Torque and Analysis of Their Cause (영구자석형 모터의 프릭션 토크 저감을 위한 고정자 철심의 열처리 및 발생원 분석)

  • Ha, Kyung-Ho;Lim, Yang-Su;Kwon, Oh-Yeoul;Kim, Ji-Hyun;Kim, Jae-Kwan
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.10
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    • pp.1752-1758
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    • 2008
  • This paper deals with the reduction of friction torque in permanent magnet motors by using the heat treatment of stator core. The stator core is made of electrical steel sheared by the punching die. From the punching process, large mechanical stress acting on the edge of stator tooth induces significant plastic and elastic deformation and then cause the change of magnetization properties. Then, the mechanical and magnetic unbalance in the sheared region of stator tooth produced by material cutting has influence on the friction torque. This paper investigated the effect of the punching process on the magnetization process and the mechanical deformation, and then proposed the stress relief annealing method for the reduction of friction torque among one of motor characteristics.

A study on effects of the fiber orientation and point angle on drilling characteristics of carbon fiber epoxy composite materials (탄소섬유 에폭시 복합재료의 드릴링 특성에 있어 섬유 배열방향과 선단각의 영향에 관한 연구)

  • Kim, Hyeong C.;Lee, Woo Y.;Namgung, Suk.
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.4
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    • pp.119-125
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    • 1997
  • The drilling experiment of carbon fiber epoxy composite material with WC-drill has been done under the various cutting conditions in order to minimize the problems occurred in the material while being drilled. It has been confirmed by a frequency analysis of the cutting force signals that the variation of cutting force resulted from the periodic variation of the angle between the ortating drill and the stacking angle of the carbon fiber. By the drilling experiment with several drills having different point angles, the drilling char- acteristics, which show the relations between the change in the point angle and cutting force or external surface condition, were analyzed.

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