Experimental investigation of burr reduction during EDM end-milling hybrid process

김민엽,Chang Ping Li,쿠르니아완렌디,정상태,고태조 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.6

Burrs are always generated during the end-milling process of ductile materials and have become a common challenge because a large plastic flow of the material is generated during cutting. In this research, a combination method of the end-milling and electrical discharged machining (EDM) process is proposed to suppress the generated burrs during machining; this process is called the EDM endmilling process. EDM end-milling was performed for side milling of AISI 1045 alloy steel (HRC = 28). The height of the generated burrs was measured and compared between ordinary end milling and EDM end-milling, and the experimental results indicate that the generated burrs are suppressed effectively by EDM end-milling owing to the effect of reduced plastic flow. The experimental results also indicate that the height of the generated burrs decreases when the capacitance values are increased during EDM end-milling. Furthermore, the results show that the height of the generated burrs remains unchanged by EDM end-milling when the axial depth of cut is increased.

엔드밀 가공시 절삭력을 이용한 공구날 주파수 분석법

김종도(Jong-Do Kim),윤문철(Moon-Chul Yoon),조현덕(Hyun-Deog Cho) 한국기계가공학회 2011 한국기계가공학회지 Vol.10 No.4

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.

가공물 형상에 따른 동적 및 정적 절삭력 성분 분석법

양재용(Jae-Yong Yang),윤문철(Moon-Chul Yoon),김병탁(Byung-Tak Kim) 한국기계가공학회 2012 한국기계가공학회지 Vol.11 No.4

There are many dynamic properties in measured end-milling force. So, it is difficult to predict the real static property of end-milling force. Also the behavior of end-milling force is very complex to predict with the measured one. To extract the static property from measured force, it must be filtered and its problem is closely related to a de-noising one. Also this paper presents alternative de-noising method of end-milling force using wavelet filter bank, based on the wavelet transform and its inverse one. In this paper, by comparing the measured force and its wavelet filtered one, the fundamental end-milling force property after wavelet transform is well reviewed and analyzed. This result of wavelet filtering with filter bank shows the static force of end-milling which has severe dynamic properties occurring in entry and exit state of edge emersion into the workpiece.

Modeling and Emulation of 3d Dither Stability in Orthogonal Turn-Milling

Yueqi Guan,Hanqing Guan,Gaoshen Wang,Rongling Chen 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.6

Aiming at 4-axial orthogonal turn-milling by end mill, its theoretical 3d model for stable range of dither was put forward on the basis of its cutting principle by using analytical method. Based on modal trial, the stable range leaf figure of end mill’s dither in 4-axial turn-milling with eccentricity was simulated and analyzed. The results show that besides geometrical shape of mill, material of workpiece and frequency response function of machine-tool’s structure etc that can produce dither in 4-axial turn-milling, the rotating speed of mill and cutting depth are also related to dither. In trial of 4-axial turn-milling by end mill, the results of cutting force spectrum analysis show that: cutting is stable and un-dither when frequency of cutter tooth cutting-in plays leading role in force spectrum. Dither is produced when modal frequency of system plays leading role in force spectrum, the measured value of cutting force and surface roughness are also higher than those in the condition of un-dither. Thus the theoretical model and results of emulation can predict stability of end mill’s dither in 4-axial orthogonal turn-milling with eccentricity correctly and can provide theoretical guidance for surface quality and processing efficiency of workpiece.

런아웃을 고려한 측면 엔드밀 가공의 절삭력 분석

김종도(Jong-Do Kim),윤문철(Moon-Chul Yoon),김병탁(Byung-Tak Kim) 한국기계가공학회 2012 한국기계가공학회지 Vol.11 No.4

The cutting force for peripheral end-milling considering run-out property was estimated and its result was compared with that of measured one. An experimental coefficient modelling was used for the formulation of theoretical end-milling force by considering the specific cutting force coefficient. Also, the specific cutting force, that is the multiplication of specific cutting force coefficient and uncut chip thickness, was used for the prediction of end-milling force. The end-milling force mechanics with run-out was presented for the estimation of theoretical force in peripheral end-milling by considering the geometric shape of the workpiece part. As a result, the estimated end-milling force shows a good consistency with the measured one. And it can be used for the prediction of force history in end-milling with run-out which incurs different start and exit immersion angle in entering and exiting condition.

REIVM 모델링에 의한 엔드밀 시스템의 모드 분석

김종도(Jong-Do Kim),윤문철(Moon-Chul Yoon) 한국생산제조학회 2010 한국생산제조시스템학회 학술발표대회 논문집 Vol.2010 No.10

An mode analysis of end-milling system was introduced using recursive parametric modeling analysis. Also, the numerical mode analysis of end-milling system with different conditions was performed systematically. In this regard, a recursive extended instrumental variable method(REIVM) modeling algorithm and the natural mode for real part and imaginary one was discussed. This recursive approach (REIVM) can be adopted for the on-line system identification and monitoring of an end-milling for this purpose. After experimental practice of the end-milling, the end-milling force was obtained and it was used for the calculation of FRF(Frequency response function) and mode analysis. Also, the FRF was analysed for the prediction of a end-milling system and its mode shape was acquired by solving the eigen-problem using recursive algorithm. Thus, these algorithm for the detection of natural modes of end-milling was successful in each condition. After numerical analysis of the responses, which is cutting force was conducted for the calculation of FRF and mode analysis.

REIVM 모델링에 의한 엔드밀 시스템의 모드 분석

김종도(Jong-Do Kim),윤문철(Moon-Chul Yoon) 한국생산제조학회 2010 한국공작기계학회 추계학술대회논문집 Vol.2010 No.-

An mode analysis of end-milling system was introduced using recursive parametric modeling analysis. Also, the numerical mode analysis of end-milling system with different conditions was performed systematically. In this regard, a recursive extended instrumental variable method(REIVM) modeling algorithm and the natural mode for real part and imaginary one was discussed. This recursive approach (REIVM) can be adopted for the on-line system identification and monitoring of an end-milling for this purpose. After experimental practice of the end-milling, the end-milling force was obtained and it was used for the calculation of FRF(Frequency response function) and mode analysis. Also, the FRF was analysed for the prediction of a end-milling system and its mode shape was acquired by solving the eigen-problem using recursive algorithm. Thus, these algorithm for the detection of natural modes of end-milling was successful in each condition. After numerical analysis of the responses, which is cutting force was conducted for the calculation of FRF and mode analysis.

엔드밀 가공시 절삭조건에 따른 진동응답 특성

김종도(Jong-Do Kim),김광희(Kwang-Heui Kim),윤문철(Moon-Chul Yoon) 한국기계가공학회 2024 한국기계가공학회지 Vol.23 No.5

회귀분석을 이용한 STS304의 표면거칠기에 관한 엔드밀 가공조건의 상관관계 추정(Ⅱ)

이상재,전환영,류미라,박흥식 東亞大學交附設 生産技術硏究所 2005 生産技術硏究所硏究論文集 Vol.10 No.-

End-milling has become widely used in industrial systems because it has proved effective in the manufacture of materials with various shapes. End-milling processing, using a high-precision technique and producing good surface roughness in rapid time, is required in the manufacture ofprecision machine and electronic parts. Surface roughness is affected by the conditions of end-milling, suchas cutting direction, spindle speed, feed rate and cut depth. Therefore, this study was carried out to presume for mutual relations of end-milling conditions to achieve the optimum surface roughness by regression analysis. The results showed that the coefficient of determine (R2) of the regression equation has a high reliability, 85.1%, and the regression equation of surface roughness is made by regression analysis.

A Parametric and Accurate CAD Model of Flat End Mills Based on Its Grinding Operations

Liming Wang,Lin Kong,Jian-Feng Li,Zezhong Chen 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.18 No.10

End mills are widely used in CNC machining. However, the complex structures of end mills make it difficult to define the CAD model which determines the quality and performance of virtual cutting tests. This paper presents an accurate CAD model of end mill through analyzing kinematic models of grinding processes. Initially, a common parametric representation of grinding wheel is given. Base on the given wheel profile and the design parameters of cutters including the rake angle, core diameters and pitch angle, the representation of helix flute surface is first calculated using contact theory and also the formulation of rake angle and pitch angle are investigated. Next, four design parameters are used to control the shape of the gash which is formed via Boolean operation between the given wheel and end mill. Similarly, the peripheral edges and end edges are swept using grinding simulation. Finally, integrating all the above processes, a parametric CAD model of end mill is represented. The simulation results showed that the proposed CAD model could achieve 1e-3 mm and 2e-2 deg. in accuracy, which can be used to evaluate the grinding process or improve the future FEA analysis of end-mills.