• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.9
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• pp.2225-2233
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• 1994

In order to improve the cutting ability of face mill, a model for optimal cutter shape was developed to minimize resultant cutting force by combing cutting force model and optimal technique. Wear test and surface roughness test for optimized and conventional cutter were performed. The new optimized cutter shows longer tool life of 2.29 times than conventional cutter in light cutting condition and 2.52 times in heavy cutting condition. The surface roughness of workpiece by optimized cutter is improved in heavy cutting condition, but deteriorated in light cutting condition in comparison with conventional cutter. The surface profiles of workpiece were analyzed by Fourier transformation. The distribution of cut lay left on workpiece by optimized cutter is more regular than that by the conventional cutter.

• Journal of Institute of Control, Robotics and Systems
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• v.4 no.6
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• pp.795-801
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• 1998

In this paper, we propose a machine vision algorithm for inspecting inserts which are used for milling and turning operations. Major defects of the inserts are breakage and crack on insert surfaces. Among the defects, breakages on the face of the inserts can be detected through three stages of the algorithm developed in this paper. In the first stage, a multi-layer perceptron is used to recognize the inserts being inspected. Edge detection of the insert image is performed in the second stage. Finally, in the third stage breakages on the insert face are identified using Hough transform. The overall algorithm is tested on real specimens and the results show that the algorithm works fairly well.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.3
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• pp.161-167
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• 1993

This paper deals with a new method for the machining of a die cavity defined by sculptured surfaces. In machining die cavities or pockets, process planners have been faced with some troulbes. One of the troubles ius to rebove a great deal of material within a given boundary while avoiding cutter interference. Cutter interference is a ciritical problem in NC machining of a die cavity. Even though this cavity machining has been implemented in many CAM systems, most of them can handle limited shapes of cavities or pockets. In this paper, a procedure has been developed to machine die cavity or pocket of a sculptured surface. The offset surfaces of the part surfaces and boundary surfaces are determined to calculate the intersection curves. These intersection curves form a FACE on the part surface, and the interference free tool pathe is generated by eliminating the points outside the FACE when computing the cutter contact (CC) data. Additionally, the cutter location (CL) data obtained from the CC data convert to an NC data. The NC data generated through this algorithm are verified on the CINCINNATI milling machine. A propotype die cavity machining system has been implemented in FORTRAN language and FIGARO graphics library on IRIS workstation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.6
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• pp.1157-1163
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• 2009

In order to improve in quality and productivity using the CNC machine tools, it has been endeavored to elevate production process by adding supplementary axes(2 axes) to 2,3 axial CNC machine tools. It is because the movement between the progress of work in processed goods is remarkably decreased more than that of general CNC machine tools that productivity improvement with precision maintenance can be improved. VBScript in CAD/CAM is applied to utilize CNC machine tools added supplementary axes so that Multi-axial &Multi-process manufacturin g program can be conveniently drawn up. However, there is generally much skilful work and operation by the manual program of CAD(2.5D) and CNC machine tools in the filed. As a result of conducting an experiment by COM-filing VBScript at the spot of Insert Tip for milling Face Cutter in CAD/CAM Software(2.5D), it was not only timesaving to draw up program but also more convenient than complicated Multi CAD/CAM Software to approach and possible to program various products instantaneously.

• The Journal of Korean Academy of Prosthodontics
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• v.55 no.4
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• pp.436-443
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• 2017

In the past, computer-aided design / computer-aided manufacturing (CAD/CAM) technology was the closed system that users had to use the components of only one manufacturer. At present, it has changed to the open system with the flexibility to select and use the components of various manufacturers' components according to their needs. Despite the development of dental materials and prostheses manufacturing methods, denture manufacturing has followed conventional manufacturing methods for nearly 100 years. However, studies on CAD/CAM fabricated denture have been recently carried out to overcome the disadvantages of conventional denture manufacturing. Some commercialized products using milling or 3D printing have already been applied clinically. This case report confirms the possibility of CAD/CAM dentures using 3D face scan and compared them to conventionally fabricated dentures.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.5
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• pp.145-152
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• 1998

In this research, in order to predict the cutting force using a mechanistic model, specific cutting force was firstly obtained through the cutting experiments. Band sawing process is similar to a milling, that is multi-point cutting. Therefore it is not easy matter to evaluate specific cutting force. Thus, the thickness of workpiec was made smaller than one pitch of the saw in terms of fly cutting in the face milling process. Then the cutting force was predicted by analyzing the geometric shape of a saw tooth The tooth shape used in the research was raker set style that was generally used in band sawing. And a set of teeth is comprised of three teeth, those are ranked as left, straight and right. The mechanistic model was developed in this study considered those shapes of each tooth. From the validation experiments, the predicted cutting forces coincided well with the measured ones. Therefore the predicted cutting forces can be used for the adaptive control of saw engaging feed rate in the band sawing.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.1596-1602
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• 2006

대부분의 금형 제작에 있어서 face milling은 가공물의 표면을 매끄럽게 하는 가장 중요한 마무리 공정이다. 이 마무리 단계에서 burr의 형성은 가히 탐탁지 않은 현상중의 하나가 된다. 또한, burr는 가공물의 정밀도를 감소시키고 작업자의 안전에 영향을 미치기 때문에 이를 제거하기 위해 후처리(deburring)과정을 야기 시키며, 불필요한 비용의 발생과 작업의 병목현상을 불러오게 된다. 따라서, burr의 생성 원리를 이해하고 burr의 발생을 최소화 할 수 있는 연구가 필요하게 된다. 이를 바탕으로 deburring의 비용을 줄일 수 있는 최적의 가공계획을 수립해야만 제품의 정밀도를 높일 수 있고, 작업 능률과 생산성을 향상시킬 수 있다. 본 논문에서는 지금까지의 연구보다 좀더 현실적으로 접근하기 위하여 피삭재의 형상이 line, arc, circle, spline 등의 여러 가지 형상으로 복합적으로 이루어진 복합형상에 대하여 burr의 발생을 연구하였고 이에 다중가공 경로까지 고려하여 burr의 형성을 예측할 수 있는 알고리즘을 수립하였다. 더 나아가 본 연구의 궁극적 목적인 burr를 최소로 발생시키는 가공경로를 설계할 수 있는 시스템을 개발하고자 한다

• Journal of Sensor Science and Technology
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• v.31 no.1
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• pp.57-63
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• 2022

This study describes a system that monitors the tool and cutting state of automatic beveling operation in real time. As a signal for cutting state monitoring, a motor current detected from the spindle drive system of the automatic beveling machine is used to monitor abnormal state. Because automatic beveling is processed using a face milling cutter, the cutting force mechanism is the same as the milling process. The predicted cutting torque is obtained using a cutting force model based on specific cutting resistance. Then, the predicted cutting torque is converted into the spindle motor current value, and cutting state stability is diagnosed by comparing it with the motor current value detected during beveling operation. The experimental results show that the spindle motor current can detect abnormal cutting state such as overload and tool wear during beveling operation, and can diagnose the cutting stability using the proposed equip-current line diagram.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.4
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• pp.67-77
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• 1995

In modern industry the requirement of automation of manufacturing process increases so that unmanned system has been popular as an ultimate goal of modern manufacturing process. In unmanned manufacturing process the tool fracture is a very serious problem because it results in the damage of workpieces and can stop the operation of whole manufa- turing system. In this study, image processing technique is used to detect the fracture of insert tip of face milling using multi-point-tool. In order to acquire the image information of fracture shape of rotation insert tip. We set up the optical system using a light beam chopper. In this system we can reduce the image degradation generated from stopped image of rotating insert tip using image restoration technique. We calculated the mean square error to diagnose the condition of tool fracture, and determind the criteria of tool fracture using experimental and staticstical method. From the results of this study we've developed non- contact detection technique of tool fracture using image processing method and proposed the fracture direction of automation and unmanned system considering the optimal time of tool change milling.

• Journal of the Korean Society of Industry Convergence
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• v.14 no.2
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• pp.45-52
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• 2011

Since the most exclusive machines of the modern industries which require the nano precision rates are evolved from the machine tools, the design of the stable machine tool structure is very critical. Exclusive machines for the modern industries such as semiconductor, solar cell and LED have surface machining processes which are similar to the face cutting and grinding of conventional machine tools. This study was initiated to stabilize a milling machine structure and further to help design those exclusive machines which have similar machining mechanisms. The vibrations inherent to the machine tool structures hurt the precision machining as well as damage the longevity of the structures. There have been numerous researches in order to suppress the vibrations of machine tool structures using the extra modules such as actuators and dampers. In this paper, the dynamic properties are analyzed to obtain the natural frequencies and mode shapes of a machine tool structure which reflect the main reasons of the biggest vibrations under the given operating conditions. And the feasibility of improving the stability of the structure without using any additional apparatus has been investigated with minor design changes. The result of the study shows that simple changes based on proper system identification can considerably improve the stability of the machine tool structure.