• 제목/요약/키워드: Turning machining

검색결과 331건 처리시간 0.02초

다구찌 방법에 기초한 선삭에서 진원도에 영향을 미치는 인자에 관한 평가 (An Evaluation of Factors on the Influence Roundness in Turning Based on the Taguchi Method)

  • 강신길;이창호;장성민
    • 한국생산제조학회지
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    • 제20권4호
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    • pp.495-501
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    • 2011
  • The purpose of this study is to improve the roundness of CNC turning so that helps the operator to choose the right turning conditions to produce a product with the given parameters. This paper focuses on determining the optimal levels of machining factors for circular shaft with CNC turning. For this purpose, the optimization of factors is performed based on experimental design method. A design and analysis of experiments are conducted to study the effects of these factors on the roundness by using the SIN ratio, analysis of ANOVA, and F-test. Factors, namely, fixed pressure, wall thickness, depth of cut, and feed rate are optimized with consideration of the roundness. The boring tool used in this study is a tungsten carbide coated. The material of workpiece is Al6061 and the machining method is dry cutting.

선삭가공에서의 테이퍼 홈 절삭특성에 관한 연구 (A Study on Cutting Characteristic of Tapered Groove in Turning)

  • 최치혁;김동현;이춘만
    • 한국기계가공학회지
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    • 제10권6호
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    • pp.27-32
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    • 2011
  • In recently, it is demanded development of manufacturing techniques for machining of various mechanical parts. Therefore the development of turning is one of the important manufacturing techniques. In this study, an experimental shape in tapered groove turning was suggested, and the turning process was investigated by analyzing cutting speed, feed rate, tapered angle, depth of cut. The surface roughness and cutting force change in the workpiece was measured. From the results, the optimum machining conditions are obtained by design of experiments.

선반가공시 채터 모델링과 분석에 관한 연구 (A Study on the Modeling and Analysis of Chatter in Turning Operation)

  • 윤문철;조현덕;김성근;김영국;조희근
    • 한국공작기계학회논문집
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    • 제10권4호
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    • pp.76-83
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    • 2001
  • In this study, the static and dynamic characteristics of turning process was modelled and the analytic realization of regen-erative chatter mechanism was discussed. In this regard, we have discussed on the comparative assessment of recursive times series modeling algorithms that can represent the machining process and detect the abnormal machining behaviors in precision turning operation. In this study, simulation and experimental work were performed to show the malfunction behaviors. For this purpose, new Recursive Extended Instrument Variable Method(REIVM) was adopted for the on-line system identification and monitoring of a machining process. Also, we can apply REIVE algorithms in real process for the detection of chatter frequency and dynamic property and analyze the stability lobe of the system by changing a parameter of cutting dynamics in regenerative chatter mechanics, if it is stable or unstable, Also, The stability lobe of chatter was analysed.

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초정밀 선반을 사용한 알루미늄 7075와 실리콘의 초정밀가공 특성연구 (A Study on the Precision Machining Characteristics of Aluminium 7075 and Silicon using Ultra-precision Turning Machine)

  • 김우강;김건희;원종호
    • 한국기계가공학회지
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    • 제5권4호
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    • pp.27-32
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    • 2006
  • This study aims to find the optimal cutting conditions, when are nonferrous metals(aluminum and silicon) are machined with diamond tool of diamond turning machine. Diamond turning machine has been widely used in manufacturing optical reflectors of nonferrous metals. Such as aluminium and copper are easy to be machined because of their proper ductility. But optical crystals being discussed here are characterized by their high brittleness which makes it difficult to obtain high quality optical surfaces on them. The purpose of this study is to find the optimum machining conditions for ductile cutting of silicon and aluminium.

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원추형상을 이용한 비구면 형상가공에 관한 연구 (A Study on Machining of Aspherical Surface using a cone.)

  • 이상민;박철우;이종항
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2004년도 추계학술대회 논문집
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    • pp.1348-1352
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    • 2004
  • An aspherical lens in information technology has been increased in order to enhance the optical performances. There are two kinds of approaches to machine the aspherica surface is generally conducted by the diamond turning machine, precision grinding machine, and polishing machine. This technique, however, has a problem which needs an expensive and high precision machine in order to increase the surface roughness and the machining accuracy. In this paper, a machine, which is able to machine the aspherical surface, was developed to decrease the cost. Also, the machining of the aspherical surface using a cone was carried out experimentally in order to compare the experiment with the simulation. The results showed that the machining experiments of the aspherical surface by using the titled cone were in accordance with the simulation.

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통합절삭 시뮬레이션 시스템용 선삭표면조도 시뮬레이션 알고리즘의 설계 (Design of an Algorithm to Simulate Surface Roughness in a Turning for an Integrated Machining Simulation System)

  • 장동영
    • 한국시뮬레이션학회논문지
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    • 제8권1호
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    • pp.19-33
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    • 1999
  • The fundamental issues to evaluate machine tools performance through simulation pertain to the physical models of the machine tool itself and of process while the practical problems are related to the development of the modular software structure. It allows the composition of arbitrary machine/process models along with the development of programs to evaluate each state of machining process. Surface roughness is one of the fundamental factors to evaluate machining process and performance of machine tool, but it is not easy to evaluate surface roughness due to its tribological complexity. This paper presents an algorithm to calculate surface roughness considering cutting geometry, cutting parameters, and contact dynamics of cutting between tool and workpiece as well as tool wear in turning process. This proposed algorithm could be used in the designed virtual machining system. The system can be used to evaluate the surface integrity of a turned surface during the design and process planning phase for the design for manufacturability analysis of the concurrent engineering.

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ESC 공정으로 제작된 금형강의 가공특성연구 (Machining Characteristics of Tool Steels Manufactured by Electro Slag Casting Process)

  • 김정운;김봉준;이득우;문영훈
    • 대한기계학회논문집A
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    • 제26권6호
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    • pp.1120-1126
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    • 2002
  • Machining characteristics of tool steels manufactured by electro slag casting process has been investigated in this study. For the estimation of machinability, turning and drilling tests are carried out. The chip shapes at various velocities are investigated for the comparison of turning workabilities of tool steels because the chip shapes reflect characteristics of cutting resistance. In case of drilling test, feed motor currents measured by a hall sensor are used as a measure for the drilling resistance. The machining characteristics of the tool steels are strongly correlated with tensile properties, such as tensile strength, hardness, and ductility. In case of turning workability, it was found to be favoured by the higher tensile strength, while the opposite is true far the drilling workability. The electro-slag casted materials show better turning workability in the viewpoint of chip shapes and, the quenching-tempered electro-slag casted material has relatively better drilling machinability than that of the annealed one.

고투과율 광학유리(SF57HHT) 초정밀절삭의 실험적 연구 (An Experimental Study of Ultra-precision Turning of High Transmittance Optical Glass(SF57HHT))

  • 김민재;이준기;황연;김혜정;김정호
    • 한국생산제조학회지
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    • 제21권2호
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    • pp.191-195
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    • 2012
  • Heavy flint optical glass(SF57HHT) is new material that has extremely high transmittance. Due to brittleness and high hardness, optical glass is one of the most difficult to materials for ultra-precision turning. According to the hypothesis of ductile machining, all materials, regardless of their hardness and brittleness, will undergo transition from brittle to ductile machining region below critical undefromed chip thickness. In this study, cutting test was carried out to evaluate cutting performance of heavy flint glass using ultra-precision machine with single crystal diamond bite. The machined workpiece surface topography, tool wear and surface roughness were examined using AFM and SEM. The experimental results indicate that the machining mode become the brittle mode to ductile mode, when the maximum undeformed chip thinkness is large than critical value. Tool wear mainly occurs on the flank face and its wear mechanism is dominated by abrasion. This study demonstrates the feasibility of SF57HHT by diamond turning.

고경도강(AISI 4140, HrC60)의 하드터닝에서 가공속도 및 윤활조건 변경에 따른 CBN 공구의 마모 특성 (Wear Characteristics of CBN Tools on Hard Turning of AISI 4140)

  • 양기동;박경희;이명규;이동윤
    • 한국정밀공학회지
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    • 제31권9호
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    • pp.799-804
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    • 2014
  • Hard turning is a machining process for hardened materials with high surface quality so that grinding process can be eliminated. Therefore, the hard turning is capable of reducing machining time and improving productivity. In this study, hardened AISI4140 (high-carbon chromium steel) that has excellent yield strength, toughness and wear resistance was finish turned using CBN tools. Wear characteristics of CBN tool was analyzed in dry and MQL mixed with nano-particle (Nano-MQL). The dominant fracture mechanism of CBN tool is diffusion and dissolution wear on the rake surface resulting in thinner cutting edge. Abrasive wear by hard inclusion in AISI4140 was dominant on the flank surface. Nano-MQL reduced tool wear comparing with the dry machining but chip evacuation should be considered. A cryogenically treated tool showed promising result in tool wear.

MQL 선삭가공에서 절삭력과 표면거칠기 향상에 관한 연구 (A Study on the Improvement of Cutting Force and Surface Roughness in MQL Turning)

  • 황영국;정원지;정종윤;이춘만
    • 한국공작기계학회논문집
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    • 제15권4호
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    • pp.83-91
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    • 2006
  • At present, industry and researchers are looking for ways to reduce the use of lubricants because of ecological and economical reasons. Therefore, metal cutting is to move toward dry cutting or semi-dry cutting. One of the technologies is known as MQL(Minimum Quantity Lubrication) machining. This research presents an investigation into MQL machining with the objective of deriving the optimum cutting conditions for the turning process of SM4SC. To reach these goals several finish turning experiments were carried out, varying cutting speed, feed rate, oil quantity and so on, with MQL and flood coolant. The surface roughness and cutting force results of tests were measured and the effects of cutting conditions were analyzed by the method of Analysis of Variance(ANOVA). From the experimental results and ANOVA, this research proposed optimal cutting conditions to improve the machinability in MQL turning process.