비절삭 저항상수에 따른 절삭력 예측

김종도,윤문철 한국기계가공학회 2019 한국기계가공학회지 Vol.18 No.10

Few studies have been conducted regarding theoretical turning force modelling while considering cutting constant. In this paper, a new cutting force modelling technique was suggested which considers the specific cutting force coefficients for turning. The specific cutting force is the multiplication of the cutting force coefficient and uncut chip thickness. This parameter was used for experimental modelling and prediction of theoretical cutting force. These coefficients, which can be obtained by fitting measured average forces in several conditions, were used for the formulation of three theoretical cutting forces for turning. The cutting force mechanism was verified in this research and its results were compared with each of the experimental and theoretical forces. The deviation of force was incurred by a small amount in this model and the predicted force considering feed rate, nose radius, and radial depth shows a physical behavior in main force, normal force, and feeding force, respectively. Therefore, this modelling technique can be used to effectively predict three turning forces with different tool geometries considering cutting force coefficients.

비절삭저항 상수 변화에 따른 절삭력 분석

김종도(Jong-Do Kim),윤문철(Moon-Chul Yoon) 한국기계가공학회 2014 한국기계가공학회지 Vol.13 No.2

Considering the run-out effect and cutting force coefficients, the cutting force profile of half immersion end-milling was analyzed in detail. The effects of three specific cutting-force coefficients and three edge-force coefficients are verified. Through a detailed investigation, it is proved that the radial cutting force coefficients and are the major factors which increase the cutting forces Fx and Fy in end-milling. However, the axial cutting force coefficients have no influence on the force Fx and Fy changes in end-milling. Also, the analyzed end-milling force model shows good consistency with the actual measured force with regard to Fx and Fy. Thus, this model can be used for the prediction of the force history in end-milling with run-out,and it incurs a different force history with different start and exit immersion angles as well as holding effects.

정면밀링가공에서 쟁기력을 고려한 3차원 절사력 모델링

권원태,김기대 한국공작기계학회 2002 한국생산제조학회지 Vol.11 No.2

Cutting force is obtained as a sum of chip removing force and ploughing force. Chip removing force is estimated by multiplying specific cutting pressure by cutting area. Since ploughing force is caused from dullness of a tool, its magnitude is constant if depth of cut is bigger than a certain value. Using the linearity of chip removing force to cutting area and the constancy of ploughing force regardless of depth of cut which is over a certain limit, each force is separated from measured cutting force and used to establish cutting force model. New rotation matrix to convert the measured cutting force in reference axes into the forces in cutter axes is obtained by considering that tool angles are projected angles from cutter axes to reference axes. Spindle tilt is also considered for the model. The predicted cutting force estimated from the model is in good agreement with the measured force.

선삭가공에서 절삭력을 이용한 공구마멸의 감지

윤재웅,이권용,이수철,최종근 한국공작기계학회 2001 한국생산제조학회지 Vol.10 No.1

The development of flexible automation in the manufacturing industry is concerned with production activities performed by unmanned machining system. A major topic relevant to metal-cutting operations is monitoring tool wear, which affects process efficiency and product quality, and implementing automatic tool replacements. In this paper, the measurement of the cutting force components has been found to provide a method for an in-process detection of tool wear. The static components of cutting force have been used to detect flank wear. To eliminate the influence of variations in cutting conditions, tools, and workpiece material, the force modeling is performed for various cutting conditions. The normalized force disparities are defined in this paper, and the relationships between normalized disparity and flank wear are established. Finally, artificial neural network is used to learn these relationships and detect tool wear. According to the proposed method, the static force components could provide the effective means to detect flank wear for varying cutting conditions in taming operation.

엔드밀 가공시 절삭조건이 비절삭력계수에 미치는 영향

이신영 한국공작기계학회 2004 한국생산제조학회지 Vol.13 No.6

For improvement of productivity and cutting tool life, 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, feed, 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.

밀링가공시 절삭조건이 비절삭력계수에 미치는 영향 분석

이신영 한국공작기계학회 2004 한국공작기계학회 춘계학술대회논문집 Vol.2004 No.-

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. 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 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.

正面밀링용 工具의 最適設計에 對한 모델 개발

朴鍾奉,金正顯 慶一大學校 1992 論文集 Vol.8 No.1

Based on the cutting force model, optimal designed tool which is minimized resultant cutting force is developed by computer simulation technique. On this model it was taken that objective function that minimized sum of cutting force and variables that had radial rake angle, axial rake angle, lead angle of the tool. Thereby three-dimensional optimal design model was also developed. At simulation of cutting force using conventional and optimal tool. We compared and analyzed cutting force in time domain and frequency domain. As a result of analyzing cutting force in time domain, cutting force in feed direction was reduced superiorly and fluctuation of cutting force was also reduced. Cutting force in X and Z directions had shown a little upward trend. We knew that in frequency domain amplitude of cutting frequency of insert in X and Z direction was a little up. As the reduction of cutting force and vibration, we thought that life of machine tool and tool would be longer and surface roughness of workpiece would be improved and matchine tool being would be stable.

밀링 공구의 코팅 조건이 절삭력 증가율에 미치는 영향

문창성,김준현,최석우,김주현 한국공작기계학회 2001 한국공작기계학회 춘계학술대회논문집 Vol.2001 No.-

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 N₂ and Ar but also mean temperature influence the cutting force increase rate during the end milling process.

볼엔드밀 공구에 의한 사각형상 가공시 공구 휨에 따른 절삭력 특성

김인수(In Soo Kim),김상현(Sang Hyun Kim),이동섭(Dong Sup Lee),왕덕현(Duck Hyun Wang) 한국기계가공학회 2019 한국기계가공학회지 Vol.18 No.6

Ball end mills used for high-speed and high-precision machining require longer machining time than flat end mills or face cutters, since the tool diameter is limited and the rigidity is reduced by the characteristics of the tool’s cutting edge: at the top end of the tool, the cutting speed approaches zero and hardly removes any material. Because there is little material removal at the top end of the ball end mill, the outer cutting edge performs the majority of the work; this irregular cutting force deforms the tool and shortens its life. In this study, we attached an eddy-current sensor to a tool to measure the deformation from the cutting force and we used a tool dynamometer to measure the cutting force. We found that the change in cutting force is dependent on the change in feed rate during square-shaped processing and, as the feed rate is accelerated, the cutting force also increases. Higher cutting forces increase tool deformation.

절삭력 진동 분석에 의한 가공조건 모니터링

박춘광(Chunguang Piao),김주완(Ju Wan Kim),김진오(Jin Oh Kim),신요안(Yoan Shin) 대한기계학회 2015 大韓機械學會論文集A Vol.39 No.9

본 논문은 밀링가공에서 측정되는 절삭력 진동을 분석함으로써 가공조건을 모니터링하는 실험적 기술을 다룬다. 이 기술은 앞서 보고된 절삭력 진동의 이송속도 및 절삭깊이와의 관계에 근거한다. 측정시스템은 동적 힘 센서와 신호 증폭기로 구성되고, 분석 시스템은 오실로스코프와 LabVIEW 프로그램을 갖춘 컴퓨터를 포함한다. 가공조건 중 회전속도를 일정하게 하고 이송속도와 절삭깊이를 변화시키며 실험하였다. 절삭날 수와 회전 진동수의 곱에 해당하는 절삭력 진동 성분의 크기가 가공조건과 선형으로 관계되었다. 이로써 이송속도와 절삭깊이 중 한 가지 가공조건을 알 때 절삭력 진동 분석을 통해 다른 한 가지 가공조건을 확인할 수 있다. This paper deals with an experimental technique for monitoring machining conditions by analyzing cuttingforce vibration measured at a milling machine. This technique is based on the relationship of the cutting-force vibrations with the feed rate and cutting depth as reported earlier . The measurement system consists of dynamic force transducers and a signal amplifier. The analysis system includes an oscilloscope and a computer with a LabVIEW program. Experiments were carried out at various feed rates and cutting depths, while the rotating speed was kept constant. The magnitude of the cutting force vibration component corresponding to the number of cutting edges multiplied by the frequency of rotation was linearly correlated with the machining conditions. When one condition of machining is known, another condition can be identified by analyzing the cutting-force vibration.