• 한국기계가공학회지
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• 제11권5호
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• pp.29-34
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• 2012

This study describes the selection of optimum machining conditions for a high-hardness resin by using a large 5-axis machine. The experiments were conducted to examine the main factors that affect the surface roughness, such as the spindle speed, axial and radial depths of the cut, and pattern of the cutter path. To analyze the experiment results, the factor with the biggest impact on machining was determined using the smaller-the-better characteristic of the Taguchi method; the effectiveness of the experiment was then confirmed by verifying the selected optimum machining condition.

• 대한조선학회논문집
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• 제35권2호
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• pp.51-62
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• 1998

본 연구에서는 공동수조(Cavitation Tunnel) 실험용 모형프로펠러의 5축 가공을 위해 Windows NT와 PC 환경하에서 작동하는 CAD/CAM 시스템을 개발하였다. 본 시스템은 그 성격에 따라 크게 4가지의 모듈로 구성되어 있다. 먼저, 프로펠러 설계를 위해 기존에 사용하고 있던 텍스트 위주의 S/W(Text based S/W)를 그래픽화 하여 통합함으로써 설계의 효율을 향상시켰다. 설계의 결과로 출력되는 점 데이터는 NURBS(Non-Uniform Rational B-Spline) 방법을 이용하여 복합곡면 (Composite Surface)으로 모델링하였고 가공은 황삭, 중삭, 정삭 및 잔삭으로 수행하였다. 각각의 경우에 있어서 공구와 공작물의 충돌 및 간섭을 체크하여 공구경로를 산출하였으며 그것을 역기 구학 해석하여 NC 데이터로 변환하였다. 또한, 가공의 상태를 화면상에서 검증하기위해 공구 및 공작물을 그래픽화하여 NC 데이터를 검증할 수 있도록 하였다. 끝으로 5축 가공의 가공 효율을 최대화하기 본 연구에서는 공동수조 실험용 모형프로펠러의 5축 가공을 위해 Windows NT와 PC 환경하위해 실험을 통하여 최적의 절삭조건을 선정하고 이를 시스템내에 데이터베이스화 함으로써 설계부터 가공까지를 자동으로 수행할 수 있는 시스템으로 구축하였다.

• 한국정밀공학회지
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• 제24권7호
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• pp.60-68
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• 2007

This paper presents an efficient 5-axis roughing method for centrifugal impeller. The efficient roughing is minimization of cutting time through minimizing tool tilting and rotating motions. To minimized cutting time, machining area is divided into sub-cutting regions using control points on hub curves and shroud curves of blade used to design and analyze centrifugal impeller. For sub-cutting regions, diameters of cutting tools are determined as big as possible. Then, tool paths are generated with the tilting axis and rotating axis of 5-axis machine limited and fixed, which can give more efficient machining speed and machining stability than the conventional methods. Experimental results show that the proposed method is more efficient than the conventional methods to mill with the only one cutting tool without dividing area and the previous methods to mill with simultaneous 5-axis processing with dividing area.

• 한국지능시스템학회논문지
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• 제7권5호
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• pp.1-7
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• 1997

CNC공작기계의 두 서보축을 대상으로 가공 정밀도를 향상시키기 위한 신경망 윤과제어 알고리즘을 제안한다. 이 연구에서는 두 축 상호간에 미치는 영향을 신경망의 학습 능력을 이용하여 보상하고자 한다. 윤곽제어를 위해서는 매 샘플링 주기마다 윤곽오차를 계산하여하나, 윤곽오차는 직선경로를 이동하는 경우 쉽게 계산가능하나 원호, 인볼루트곡선등 비선형 경로를 가공하는 경우에는 정확하게 계산하기 힘들다. 먼저 이 논문에서는 임의의 비선형 곡선경로에 대하여도 윤곽오차를 정확히 구해낼 수 있는 새로운 윤곽오차 모델링 방법을 제안다. 또한 이러한 윤곽오차에 대한 항을 포함하는 성능지수를 정의하고, 신경망 윤곽제어를 위한 온라인 학습법칙을 유도한다. 이러한 신경망윤곽제어기의 사용으로 시스템이 비선형 특성을 가지거나 외부 환경이 변화하는 경우에도 좋은 윤곽제어 성능을 유지할 수 있다.

• 대한기계학회논문집
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• 제17권8호
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• pp.2012-2022
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• 1993

For the machining of the sculptured surfaces on 5-axis CNC milling machine, the milling cutter direction vector was determined in the study (I) with 5-axis post-processing. Thus, it was possible to cut the sculptured surfaces on five-axis CNC milling machine with the end mill cutter. Then, for smooth machined surfaces in five-axis machining of free-from surfaces, this study develops an algorithm for prediction of cusp heights. Also, it generates tool path such that the cusp heights are constrained to a constant value or under a certain value. For prediction of the cusp height between two basis points, a common plane, containing the line crossing two basis points and the summation vector of two normal vectors at two basis points, is defined. The cusp height is the maximum value of scallops on the common plane after end mill cutter passes through the common plane. Sculptured surfaces were machined with CINCINNATI MILACRON 5-axis machining center, model 20V-80, using end mill cutter. Cusp heights were verified by 3-dimensional measuring machine with laser scanner, WEGU Messtechnik GmbH.

• 한국정밀공학회지
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• 제15권2호
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• pp.146-153
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• 1998

NC machines with 4 or 5 axes are capable of various tool approach motions, which makes interference-free and high machinablity machining possible. This paper deals with how to integrate these two advantages (interference-free and high machinability machining) in multi-axes NC machining with a ball-end mill. Feasible tool approach region at a point on a surface is first computed, then among which an approach direction is determined so as to minimize the cutting force required. Tool and spindle volumes are considered in computing the feasible tool approach region, and the computing time is improved by trans-forming surface patches into minimal enclosing spheres. A cutting force prediction model is used for estimating the cutting force. The algorithm is developed so as to be applied to 4- or 5-axes NC machining in common.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.245-246
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• 2006

For developing 5-axis laser cutting systems, many problems such as rotating of laser head or table, 5-axis tool path generation and collision avoidance between laser head and product should be solved. In this paper, a five-axis laser cutting machine with table swivel and rotary type configuration is developed. The five axes (X,Y,Z,A,B) are controlled and interfaced to PC via MMC board. Two kinds of CAM S/W such as commercial 5-axis CAM S/W(Euclid) and UG-API are engaged to generate NC code for the developed 5-axis laser cutting machine.

• 한국정밀공학회지
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• 제13권6호
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• pp.161-167
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• 1996

In five-axis milling, optimal CL-data (cutter location data) should be generated to have advantages over three-axis milling in terms of accuracy and efficiency. This paper presents an algorithm for generating collision-free CL-data for five-axis milling using potential energy method. By virtually charging the cutter and part surfaces with static electricity, global collision as wells as local interference is eliminated. Additionally, machining efficiency is improved by minimizing the curvature difference between the part surface and tool swept surface at a CC-point (cutter contact point) simultaneously.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2002년도 금형가공 심포지엄
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• pp.53-60
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• 2002

Recently, the development of aerospace and automobile industries brought new technological challenges, related to the growing complexity of products and new geometry models. High speed machining using 5-Axis milling machine is widely used for 3D sculptured surface parts. 5-axis milling of turbine blade generates the vibration, deflection and twisting caused from thin and cantilever shape. So, the surface roughness and the waviness of workpiece are not good. In this paper, The effects of cutter orientation and lead/tilt angle in 5-Axis high speed ball end-milling of turbine blade were investigated to improve the geometric accuracy and surface integrity. The experiments were performed at lead/tilt angle $15^{\circ}$ of workpiece with four cutter directions such as horizontal outward, horizontal inward, vertical outward, and vertical inward. Workpiece deflection, surface roughness and machined surface were measured with various cutter orientations such as cutting direction, and lead/tilt angle. The results show that when 5-axis machining of turbine blade, the best cutting strategy is horizontal inward direction with tilt angle. The results show that when 5-axis machining of turbine blade, the best cutting strategy is horizontal inward direction with tilt angle.

• 한국정밀공학회지
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• 제17권9호
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• pp.53-61
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• 2000

The manufacture of a marine propeller typically requires long lead time to generate 5-axis tool path. Hence it may take several weeks to manufacture a satisfactory propeller with a general purpose CAD/CAM system. In this research a dedicated 5-axis CAD/CAM system for machining marine propellers has been developed, The system employs various methods to enhance the productivity : interference-free tool path generation employing check vectors and optimum cutter size determinants. In addition an iterative NURBS modeling technique is used to improve the accuracy of the modeled surface and effective cutting conditions are determined and recommended empirically to increase the productivity. The proposed CAD/CAM system has been implemented with C++ and OpenGL graphic library on the Windows system. The system validation and sample results are also given and discussed.