• Proceedings of the KSME Conference
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• 2000.11a
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• pp.724-729
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• 2000

In end milling process the undeformed chip thickness and the cutting force components vary periodically with phase change of the tool. In this study, up end milling process is transformed to the equivalent oblique cutting. The varying undeformed chip thickness and the cutting force components in end milling process are replaced with the equivalent average ones. Then it can be possible to analyze the chip-tool friction and shear process in the shear plane of the end milling process by the equivalent oblique cutting model. According to this analysis, when cutting SM45C steel, 72% of the total energy is consumed in the shear process and the balance is consumed in the friction process.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.10
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• pp.1520-1527
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• 2001

In end milling process the undeformed chip thickness and the cutting force components vary periodically with phase change of the tool. In this study, up end milling process is transformed to the equivalent oblique cutting. The varying undeformed chip thickness and the cutting force components in end milling process are replaced with the equivalent average ones. Then it can be possible to analyze the chip-tool friction and shear process in the shear plane of the end milling process by the equivalent oblique cutting model. According to this analysis, when cutting SM45C steel, 72% of the total energy is consumed in the shear process and the balance is consumed in the friction process.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.95-100
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• 2001

Recently, coated milling cutters are widely used for improving the productivity of cutting processes through high speed cutting and longer tool life. In metal cutting, cutting force increase rate is important factor to diagnose the cutting conditions because the amount of tool wear directly influences the cutting forces. As the cutting length increases, the worn cutter increases the cutting forces. In this study, the effect of coating process of end milling cutter on the cutting performance, especially on the cutting force increase rate, is investigated. The results acquired through the cutting test measuring cutting force increase rate show that not only the injection quantity of $N_2$ and Ar but also mean temperature influence the cutting force increase rate during the end milling process.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.13 no.6
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• pp.1-9
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• 2004

For improvement of productivity and cutting tool lift, cutting force in end milling needs to be predicted accurately. In order to analyze cutting force, the cutting dynamics was modelled mathematically by using chip load, cutting geometry, and the relationship between cutting forces and the chip load. Specific cutting force coefficients of the cutting dynamics model were obtained by average cutting forces, tool diameter, cutting speed, fled, axial depth and radial depth of cut. The effects of the cutting conditions on the specific cutting force constants in milling were studied. The model is verified through comparisons of model predicted cutting forces with measured cutting forces obtained from machining experiments.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.814-817
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• 2000

This paper has two purposes. One is to investigate the effect of the helix angle of endmilling cutter on the cutting haracteristics of inconel 718 in down endmilling. To this end a newly developed cutting force model in down end milling process is presented. Using this cutting force components of 4-tooth endmills with various helix angles have been predicted. Predicted values of cutting force components are well coincide with the measured ones. The other is to compare the down endmilling characteristics of lnconel 718 with those of the up milling previously presented. In up endmilling as the helix angle becomes larger the radial and tangential components of the specific cutting force ($K_1 and K_r$) decrease. While in down milling $K_1 and K_r$ become smaller as the helix angle decrease.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.4
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• pp.1-7
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• 2011

The mode analysis of end-milling was introduced using recursive parametric modeling. Also, a numerical mode analysis of FRF in end-milling at different conditions was performed systematically. In this regard, a REIVM(recursive extended instrumental variable method) modeling algorithm was adopted and natural modes of real and imaginary part were discussed. This recursive approach can be used for the on-line system identification and monitoring of an end-milling for this purpose. For acquiring a cutting force, an experimental practice was performed. And these end-milling forces were used for the calculation of FRF(Frequency response function) and its mode analysis. Also, the FRF was analysed for the prediction of end-milling system. As a results, this algorithm was successful in each condition for the detection of natural modes of end-milling. After numerical analysis of the FRF, the tooth passing frequency was discriminated in their FRF, power spectrum and mode calculation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.947-950
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• 2000

The purpose of this paper is to investigate the effect of the helix angle of endmilling cutter on the cutting characteristics of inconel 718 in up endmilling. To this end cutters with helix angle of $20^\circ$, $30^\circ$, $40^\circ$ and $50^\circ$ degree have been prepared. And a modified cutting force model in up end milling process is presented. Using this cutting force components of 4-tooth endmills with various helix angles have been predicted. Predicted values of cutting force components are well coincide with the measured ones. As helix angle increases overlapping effects of the active cutting edges increase.

• 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.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.13 no.4
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• pp.9-15
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• 2004

A reasonable analysis of cutting force in end milling may give much advantage to improvement of productivity and cutting tool life. In order to analyze cutting force, the cutting dynamics was modelled mathematically by using chip load, cutting geometry, and the relationship between cutting forces and the chip load. The specific cutting constants of the cutting dynamics model were obtained by average cutting forces, tool diameter, cutting speed, feed, axial depth, and radial depth of cut. The model is verified through comparisons of model predicted cutting forces with measured cutting forces obtained from machining experiments. The results showed good agreement and from that we could predict reasonably the cutting forces in end milling.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.1059-1062
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• 1995

In cutting system, relative displacement between rool and workpiece is very important. Even though there have been so many works for modeling cutting process of end-milling, most of them have considered only one displacement of either tool or workpiece instead of both. In this paper, the relative displacement between tool and workpiece is considered for modeling cutting process of end-milling using simple experimental modal analysis and cutting force simulation program is developed. In cutting force model, instantaneous uncut chip thickness model is used and Runge-Kutta method is used for the simulation of time varying cutting system.