• Title/Summary/Keyword: Cutting Shape

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Cutting Condition Selection for Geometrical Accuracy Improvement in End Milling (엔드밀 가공에서 형상 정밀도 향상을 위한 절삭 조건 선정)

  • 류시형;최덕기;주종남
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1784-1788
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    • 2003
  • For the improvement of geometrical accuracy in end milling, cutting method and cutting condition selection are investigated in this paper. As machining processes are composed of several steps such as roughing, semi-finishing. and finishing, cutting forces and tool deflection are calculated considering surface shape generated by the previous cutting. The effects of tool teeth numbers, tool geometry, and cutting conditions on the form error are analyzed. Using the from error prediction method from tool deflection, cutting condition for geometrical accuracy improvement is discussed. The characteristics and the difference of generated surface shape in up and down milling are dealt with and over-cut free condition in up milling is presented. The form error reduction method by alternating up and down milling is also suggested. The effectiveness of the presented method is examined from a set of cutting tests under various cutting conditions. This research contributes to cutting process optimization for the geometrical accuracy improvement in die and mold manufacture.

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Feedrate Optimization in the Ball Endmilling Process Considering Shape Features (볼 엔드밀 가공시 형상특징을 고려한 이송속도의 최적화에 관한 연구)

  • Kim, Byeong-Hee
    • Journal of Industrial Technology
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    • v.16
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    • pp.257-265
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    • 1996
  • When machining of a free-form surface with a ball endmill it is very important to select proper cutting conditions considering the geometrical shape of a workpiece to make the production more effective and reduce the machining time. Even though the same cutting conditions and materials are used, the cutting system of different geometry part machining shows the different static/dynamic characteristics. In this study, through various cutting experiments, we can construct the data base of stable cutting conditions for the machining of a Zine Alloy. We can get some relational plots between the optimal feedrates and classified shape features and parameters. On the basis of these results, we can develop the feedrate optimization program OptiCode. The developed program make it possible to reduce the cutting time and increase the machining accuracies.

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Bearing Lobe Profile and Cutting Force Modeling (베어링의 로브형상과 절삭력 모델링)

  • 윤문철;조현덕;김성근
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1998.10a
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    • pp.343-349
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    • 1998
  • A modeling of machined geometry and cutting force was proposed for the case of round shape machining, and the effects of internally machined profile are analyzed and its realiability was verified by the experiments of roundness tester, especially in boring operation in lathe. Also, harmonic cutting force model was proposed with the parameter of specific cutting force, chip width and chip thickness, and in this study, we can see that bored workpiece profile was also mapped into cutting force signal with this model. In general, we can calculated the theoretical lobe profile with arbitrary multilobe. But in real experiments, the most frequently measured numbers are 3 and 5 lobe profile in experiments. With this results, we can predict that these results may be applied to round shape machining such as drilling, boring, ball screw and internal grinding operation with the same method.

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Determination of Flow Stress and Cutting Force Prediction of Ti-6Al-4V Material for 3D Printer using S-K Constitutive Equation (S-K 구성방정식을 이용한 프린터용 3D Ti-6Al-4V 재료의 유동응력 결정 및 절삭력 예측)

  • Park, Dae-Gyoun;Kim, Tae-Ho;Jeon, Eon-Chan
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.17 no.6
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    • pp.68-74
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    • 2018
  • Study on the Ti-6Al-4V have been carried out using cutting simulation, and researches for cutting force and chip shape prediction have been actively conducted under various conditions. However, a 3D printer application method using Ti-6Al-4V metal powder material as a high-power method has been studied for the purpose of prototyping, mold modification and product modification while lowering material removal rate. However, in the case of products / parts made of 3D printers using powder materials, problems may occur in the contact surface during tolerance management and assembly due to the degradation of the surface quality. As a result, even if a 3D printer is applied, post-processing through cutting is essential for surface quality improvement and tolerance management. In the cutting simulation, the cutting force and the chip shape were predicted based on the Johnson-Cook composition equation, but the shape of the shear type chip was not predictable. To solve this problem, we added a damaging term or strain softening term to the Johnson-Cook constitutive equation to predict chip shape. In this thesis, we applied the constant value of the S-K equations to the cutting simulation to predict the cutting force and compare with the experimental data to verify the validity of the cutting simulation and analyzed the machining characterization by considering conditions.

End shape and rotation effect on steel pipe pile installation effort and bearing resistance

  • Saleem, Muhammad A.;Malik, Adnan A.;Kuwano, Jiro
    • Geomechanics and Engineering
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    • v.23 no.6
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    • pp.523-533
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    • 2020
  • The current study focuses on the effect of the end shape of steel pipe piles on installation effort and bearing resistance using the pressing method of installation under dense ground conditions. The effect of pile rotation on the installation effort and bearing resistance is also investigated. The model steel piles with a flat end, cone end and cutting-edge end were used in this study. The test results indicated that cone end pile with the pressing method of installation required the least installation effort (load) and showed higher ultimate resistance than flat and cutting-edge end piles. However, pressing and rotation during cutting-edge end pile installation considerably reduces the installation effort (load and torque) if pile penetration in one rotation equal to the cutting-edge depth. Inclusion of rotation during pile installation reduces the ultimate bearing resistance. However, if penetration of the cutting-edge end pile equal to the cutting-edge depth in one rotation, the reduction in ultimate resistance can be minimized. In comparing the cone and cutting-edge end piles installed with pressing and rotation, the least installation effort is observed in the cutting-edge end pile installed with penetration rate equal to the cutting-edge depth per rotation.

Characteristics of Ball End Milling and Rotary Die-sinking Electrical Discharge Machining for the Cutting Inclination Location (가공경사면 위치에 따른 볼엔드밀가공과 회전식 형조방전가공 특성)

  • 왕덕현;김원일;박성은;박창수
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.11 no.5
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    • pp.73-80
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    • 2002
  • In this study, work materials of the ree form surface shape was machined by ball end mill cutter according to the change of cutting location and depth, and the acquired data of cutting force, tool deflection and shape accuracy were analyzed. Cutting force results were obtained with tool dynamometer and tool deflection values were measured by a couple of eddy-current sensors. Shape accuracy was obtained by roundness tester and surface profile measuring machine. As inclination angle was decreased, cutting force was increased. Cutting force showed large value at $105^{\circ}$ and $150^{\circ}$. Tool deflection was less at down milling than at up milling, decreased at 45$^{\circ}$ and 120$^{\circ}$, and shown large tool deflection at $150^{\circ}$. Roughness values were found to be bad in the inside of surface shape tool deflection. Surface accuracy was obtained better precision in down milling than in up milling.

Machinability evaluation according to variation of tool shape in high speed machining (고속가공용 엔드밀공구의 형상변화에 의한 성능평가)

  • 강명창;김정석;이득우;김광호;하동근
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2001.10a
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    • pp.393-398
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    • 2001
  • The technique of high speed machining is widely studied in machining fields, because the high efficiency and accuracy in machining can be obtained in high speed machining. Unfortunately the development of tool for high speed machining in not close behind that of machine tool. In this study, several types flat endmill is prepared for obtaining data according to tool shape. Especially, we concentrated in helix angle, number of cutting edge, rake angle and relief angle. Machinability is measured by cutting force, tool life, tool wear, chip shape and surface roughness according to cutting length. 3-axis cutting forces are acquired from the invented tool dynamometer for high speed machining. Particularly, we found out that the axial cutting force waveform has a good relation with tool wear features. By above results, it is suggested the endmill tool with $45^{\circ}$ helix angle, 6 cutting edge, $-15^{\circ}$ rake angle and $12^{\circ}$ relief angle be suitable for high speed machining

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A Study of Explosive Jet-cutting Technology by Linear Shape Charges (성형폭약에 의한 폭발절단기술에 관한 연구)

  • 이병일;박근순;공창식;김광태
    • Tunnel and Underground Space
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    • v.10 no.4
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    • pp.516-525
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    • 2000
  • Recently, the demand for pollution-free demolition work of old reinforced concrete and steel structure has rapidly increased as the redevelopment of urban area has been accelerated. This study deals with linear shape charges for explosive jet cutting on steel structure. We have tested material and shape of steel structure, characteristics of thickness and strength, shape of linear shape charges, type of shape charges, cumulative charges, type of liner, stand-off distance, detonation method. effect of sound and vibration by air blast in explosive jet cutting method. So, We developed linear shape charges in order to take advantage of optimum explosive jet cutting condition. Shape charges were made of PETN explosives. We obtained the experimental formula to decide the amount of explosive needed for thickness of steel structure plate. There are prospects for application of the explosion curving technology under the open space conditions for dismantling the steel structure and steel bridge, scrapped old boats, which are going out of service.

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Drill Shape and Cutting Conditions for Environmentally Conscious Drilling (환경친화적 건식 드릴링을 위한 드릴형상 및 절삭조건)

  • 고태조
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.9 no.2
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    • pp.36-44
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    • 2000
  • In this paper drill shape and cutting conditions for environmentally conscious dry drilling of A319 Al-alloy are studied by experimental method. The experiment is planned with Taguchi's method that is based on the orthogonal array of design factors. The result is summarized as follows (1) Drill geometry optimization can increase the number of holes in dry drilling and also large helix angle and large point angle are desirable in dry drilling. (2) It is found that cutting conditions that is cutting speed and feed rate are closely related to the drill geometry(3) For dry drilling of Al-alloys drill shape and cutting conditions are selected and tested by experimental method. But it is found that the perfect dry drilling is difficult because of the machining characteristics of Al-alloys and so new machining method such as minimal lubricant application is required.

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A study on the machinability of Carbon Fiber Reinforced Plastics on tool shape (공구형상에 따른 CFRP(Carbon Fiber Reinforced Plastics) 복합재료의 절삭 특성에 관한 연구)

  • Shin, Bong-Cheul;Kim, Kyu-Bok;Ha, Seok-Jae;Cho, Myeong-W
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.20 no.6
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    • pp.799-804
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    • 2011
  • CFRP(Carbon Fiber Reinforced Plastics) has been used many industries aerospace, automobile, medical device and building material industries, etc. Because it is lighter than other metals and has good properties, such as rigidity, strength and wear. CFRP may be cured integrity. However, it needs postprocessing similar to drilling or endmilling for shape cutting and combination of various material. In this paper, tool dynamometer and accelerometer used to signal analysis for machining properties under various cutting conditions and tool shape changes. In addition, microscope used to verify the machined CFRP surface. As the results, it was found that the cutting force and the vibration were decreased in the increasing of cutting edge (2-flute < 4-flute < composite tool), and the good machined surface can be obtained in this experiments.