• Title/Summary/Keyword: 절삭력모델

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The Effect of Back Rake Angle of Tool for Specific Cutting Resistance in Turning (선삭에서 공구의 윗면경사각이 비절삭저항에 미치는 영향)

  • 김정현
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.7 no.6
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    • pp.80-89
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    • 1998
  • Back rake angle of tool is one of the fundamental effects to the cutting ability. In this paper, for several back rake angle of lathe tool (-5$^{\circ}$ , 0$^{\circ}$ , 5$^{\circ}$ , 10$^{\circ}$ , 15$^{\circ}$ ), we experimentally examine cutting forces via orthogonal cutting. Using measured cutting forces, a formula for specific cutting resistance is derived according to the variation of tool angle. Also, the measured cutting forces are analyzed in both time and frequency domain. Cutting parameters are obtained by measuring the thickness of chip, and the effect of the back rake angle of tool is manifested. This study maintains the predicted cutting model with improved accuracy.

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A Study on the Instantaneous Shear Plane Based Cutting Force Model for End Milling (엔드밀링에서 순간전단면을 이용한 절삭력 모델 연구)

  • Hong, Min-Sung
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.11 no.4
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    • pp.34-43
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    • 2002
  • The purpose of this paper is to further extend the theoretical understanding of the dynamic end milling process and to derive a computational model to predict the milling force components. A comparative assessment of different cutting force models is performed to demonstrate that the instantaneous shear plane based formulation is physically sound and offers the best agreement with experimental results. The procedure f3r the calculation of the model parameters used in the cutting force model, based on experimental data, has been presented. The validity of the proposed computational model has been experimentally verified through a series of cutting tests.

An analytical Machining models based on Flow Stress Properties for Non-Heat Treated and Heat Treated AISI 4140 Steel (열처리 및 비 열처리 AISI4140강의 유동응력 물성치를 기초로 하는 해석적 가공 모델 연구)

  • Lee, Tae-Hong
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.20 no.4
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    • pp.419-426
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    • 2011
  • In this study, an experimental and theoretical program were carried out to determine the cutting forces and chip formation at different cutting speeds using a 0.4mm nose radius ceramic insert and -7 rake angle for non heat-treated AISI 4140 (27HRc) and heat-treated AISI 4140 (45 HRc) steel. The results obtained were compared to show the hardness differences between the materials. The secondary deformation zone thicknesses when comparing the two materials show different physical structure but similar size. These results were also discussed in light of the heat treatment and the effects it had on the machining characteristics of the material. In addition, the Oxley Machining Theory was used to predict the cutting forces for these materials and a comparison made. The predicted cutting performances were verified experimentally and showed good agreement with experimental data.

A Study on the Precision Machining during End Milling Poeration by Prediction of Generated Surface Topography (엔드밀 가공시 표면형성 예측을 통한 정밀가공에 관한 연구)

  • 이상규;고성림
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.04a
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    • pp.788-793
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    • 1997
  • The surface,generated by end milling operation, is deteriorated by tool runout,vibration,friction,tool deflection, etc. In many source,deflection of tool affects to surfave accuracy. To develop a surface accracy model,method for the prediction of the topography of machined surfaces has been developed based on models of machine tool kinematics and cutting tool geometry. This model accounts for not only the ideal geometrical surface, but also the deflection of tool resulted in cutting force. For the more accurate prediction of cutting force,flexible end mill model is used to simulate cutting process. Compute simu;ation have shown the feasibility of the surface generation system.

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정면 밀링의 절삭력 해석을 위한 평균 비절삭저항 모델의 개발

  • 이병철;황정철;김희술
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1992.10a
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    • pp.28-33
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    • 1992
  • The paper describes a new mean specific cutting pressure model in order to improve the accuracy of prediction of cutting force for face milling. The new mean specific cutting pressure model produces a mean specific cutting pressure and coefficients applied to existing cutting model not by traditional method but by considering intermittence and variation of chip width according to insert cutting position to take into cutter geometry machining condition and width of workpiece, and considering a mean measure force according to spindle eccentricity and mean measure force according to spindle eccentricity and insert initial position errors.. The simulated forces in X, Y, Z directions resulted from the simulated cutting model and the new cutting model are compared with measured forces in the time end frequency domains. The simulated forces in the time and frequency domains. The simulated forces resulted from the new cutting model have a good degreement with measured forces in comparison with these resulted from the existing cutting model

Prediction of Cutting Forces for the Chip Breaker Insert in Milling (밀링용 칩 브레이커 인서트의 절삭력 예측)

  • 김국원;이우영;신효철
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.11
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    • pp.2664-2675
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    • 1993
  • In this paper, the effects of chip breaker configuration on cutting forces for various cutting conditions are investigated and a method for predicting cutting forces effectively for chip breaker insert in milling is described. Based on the shear plane model and the relevant equations already existing for the relation among the parameters, the method makes use of the analytic geometric approach considering the configuration of cutting too by a 3-dimensional coordinate transformation matrix. The groove type chip breaker insert is modeled to be a double rake insert, represented by the first radial rake angle, the second radial rake angle and the length of land, and the program analyzing the cutting forces is developed. The program capability is verified by comparing the results with the experimental ones for a single cutter; and in case of primary cutting forces, the results of simulation and experiments agree very well showing 2%~16.7% difference within the feed rate range investigated.

A Study on the Identification of Cutter Offset by Cutting Force Model in Milling Process (밀링가공에서 절삭력 모델을 이용한 커터 오프셋 판별에 관한 연구)

  • 김영석
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.7 no.2
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    • pp.91-99
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    • 1998
  • This paper presents a methodology for identifying the cutter runout geometry in end milling process. Cutter runout is common but undesirable phenomenon in multi-tooth machining because it introduces variable chip loading to insert which results in a accelerated tool wear. amplification of force variation and hence enlargement vibration amplitude From understanding of chip load change kinematics, the analytical cutting force convolution model was formulated as the angular domain convolution model was formulated as the angular domain convolution of three dynamic cutting force component functions. By virtue of the convolution integration property, the frequency domain expression of the local cutting forces and the chip width density of the cutter. Experimental study is presented to validate the analytical model. This study provides the in-process monitoring and compensation of dynamic cutter runout to improve machining tolerance and surface quality for industrial application.

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The Prediction of Tool Wear by Cutting Force Model in the Machining of Die Material (금형강 가공에서 절삭력 모델에 의한 공구마멸의 예측)

  • 조재성;강명창;김정석
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1994.10a
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    • pp.61-66
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    • 1994
  • Tool condition monitoring is one of the most important aspects to improve productivity and quality and to achieve intelligent machining system. The tool state is classified into three groups as chipping, wear and fracture. In this study, wear of a ceramic cutting tool for hardened die material (SKD11) was investigated. Flank wear was occured more dominant than crarer wear. Therefore, to predict flank wear, the modeling of cutting force has been performed. The modeling of cutting force by an assumption that act the stress distribution on the tool face obtained through a numerical analysis. The relationships between the cutting force and the tool wear can be constructed by machining paraneters with cutting conditions. Experiments were performed under the various cutting conditions to ensure the validity of force models. The theoretical predictions of the flank wear is approximately in good agreement with experimental result.

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A Development of a Simulation System for Compensating Tool Deflections of a Ball-end Milling (볼 앤드밀 가공에서의 공구 처짐 보정을 위한 시뮬레이션 시스템 개발)

  • 박홍석;유재학;이재종
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2000.10a
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    • pp.206-210
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    • 2000
  • 금형 및 자동차 산업에 널리 사용되는 앤드밀 가공에서 종종 소비자가 요구하는 가공 정밀도를 충족시켜 주지 못하는 경우가 발생한다. 이것은 열 변형, 공구 마모, 공작 기계 자체의 오차, 공구 처짐 등 다양한 원인이 존재한다. 본 연구에서는 공구 처짐으로 발생되는 가공 오차를 줄임으로써 가공 정밀도를 향상하기 위한 시스템을 개발하고자 한다. 이를 위해 3차원 볼 앤드밀의 절삭력 모델을 개발하고 시뮬레이션한다. 또한, 상용 CAD 시스템의 형상 및 가공 정보를 이용함으로써 모델링에서부터 가공 경로 생성, 그리고 경로 보정이라는 과정을 일괄적으로 수행할 수 있도록 한다. 이를 통해 사용자는 가공 전 시뮬레이션을 통해 가공 오차를 줄일 수 있는 기회를 제공 받는다. 따라서, 실제 가공에서 보다 높은 가공 정밀도를 얻을 수 있을 것이다.

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Analysis on the Precision Machining in End Milling Operation by Simulating Surface Generation (엔드밀 가공시 표면형성 예측을 통한 정밀가공에 관한 연구)

  • Lee, Sang-Kyu;Ko, Sung-Lim
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.4 s.97
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    • pp.229-236
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    • 1999
  • The surface, generated by end milling operation, is deteriorated by tool runout, vibration, tool wear and tool deflection, etc. Among them, the effect of tool deflection on surface accuracy is analyzed. Surface generation model for the prediction of the topography of machined srufaces has been developed based on cutting mechanism and cutting tool geometry. This model accounts for not only the ideal geometrical surface, but also the deflection of tool due to cutting force. For the more accurate prediction of cutting force, flexible end mill model is used to simulate cutting process. Computer simulation has shown the feasibility of the surface generation system. Using developed simulation system, the relations between the shape of end mill and cutting conditions are analyzed.

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