• Design & Manufacturing
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• 제17권4호
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• pp.1-7
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• 2023

In the fabrication of curved multi-display glass for automotive use, the surface roughness of the mold is a critical quality factor. However, the difficulty in detecting micro-cutting signals in a micro-machining environment and the absence of a standardized model for predicting micro-cutting forces make it challenging to intuitively infer the correlation between cutting variables and actual surface roughness under machining conditions. Consequently, current practices heavily rely on machining condition optimization through the utilization of cutting models and experimental research for force prediction. To overcome these limitations, this study employs a surface roughness prediction formula instead of a cutting force prediction model and converts the surface roughness prediction formula into experimental data. Additionally, to account for changes in surface roughness during machining runtime, the theory of position variables has been introduced. By leveraging artificial neural network technology, the accuracy of the surface roughness prediction formula model has improved by 98%. Through the application of artificial neural network technology, the surface roughness prediction formula model, with enhanced accuracy, is anticipated to reliably perform the derivation of optimal machining conditions and the prediction of surface roughness in various machining environments at the analytical stage.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.323-328
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• 2004

Finish machining of a curved surface is often carried out by an NC system with curved interpolation in a high speed machining strategies. This study aims to develop the NURBS interpolator for the PC-NC based machine tools. In the case of a finish cut using a ball-end mill in high speed machining, low machinability at the bottom of a tool produces a harmful effect on surface roughness. The developed interpolator considers the relation between inclined angle, surface roughness, and feed rate, and adjusts real-time feed rate in order to generate surfaces which have isotropic surface roughness. The proposed interpolator is fully implemented and an experimental results are shown.

• 한국기계가공학회지
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• 제9권6호
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• pp.29-35
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• 2010

Recently the industry high-speed machining has been applied to the automotive, aircraft, electronics parts machining because the effect of cost savings, machining time reduction and productivity improvement. In this study recently the aircraft structural aluminum alloy 7075 used in cutting the ball end-mill on the surface roughness terms most affect the parameters of the spindle speed and feed rate on the surface roughness of the work-piece according to the cutting depth is to investigate. Cutting depth at 0.3 mm has the lowest surface roughness.

• 한국정밀공학회지
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• 제13권9호
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• pp.156-164
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• 1996

Tool interference is one of the most critical problems in machining die cavities and punches. When machining concave or convex regions of cavities with large radius tool in rough cutting, the tool easily overcuts or undercuts the portions of the surface, which result in machining inaccuracy. So the generation of interference-free tool path must be required for more efficient rough cutting. In this paper, we present a method for modeling die cavities which consist of simple surface or analytic compoyund surfaces and present an algorithm for checking and removing the tool interference occurred in machining the die cavities. Using these algorithms, we can represent a die cavity, and check the interfer- ence regions, and then remove these interferences. Especially we focus on the side interference in the sides of analytic elements and base surface boundary.

• 한국정밀공학회지
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• 제28권3호
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• pp.315-322
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• 2011

High-accuracy micropatterns such as V-shaped microgrooves are increasingly in demand for various engineering areas. And the technical trend goes for large surface areas in precision machining technology. So micropatterns with large surface areas are expected to play an increasingly important role in today's manufacturing technology In this study, we focused on developing machining technologies. First, a machine vision system for precise tool setting is developed. Second, an on-machine measurement (OMM) system for large-area measurement is implemented. And also software for tool path generation and simulation is developed. With these technologies we fabricated large-surface micropatterns in an electroless nickel-plated workpiece with single-crystal diamond tools and a 32-in, $675mm{\times}450mm$ mold with tens of V-and pyramid-shaped micropatterns.

• 한국공작기계학회논문집
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• 제17권2호
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• pp.71-76
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• 2008

Micro end-milling is one of effective technology that is able to do ultra-precision machining while increasing the productivity and has wide application field. But selection of machining condition is very difficult because of complicated machining mechanism. Therefore this study was carried out to select working factors to get the optimum surface roughness. Machining condition are depth of cut, feed rate and spindle revolution. The result of this study showed that Surface roughness was affected, in the other of depth of cut, spindle revolution, feed rate. And this study provided an regression equation relating surface roughness to working factors through Regression Analysis and determination coefficient of regression equation had a satisfactory reliability of 79%.

• 한국생산제조학회지
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• 제19권3호
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• pp.402-406
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• 2010

Conventionally, the machined surface roughness in nano-second(ns) laser machining is damaged and rough due to thermal effects. To obtain the improved surface finish, the ultrasonic vibration is applied to ns-laser machining. The ultrasonic vibration jig is developed to apply the ultrasonic high precision motion to workpieces. And then the ns-laser machining is conducted to compare the effects of the ultrasonic vibration. The results show that the surface roughness with ultrasonic vibration is smoother than that without the vibration. The phenomenon could be explained as enhancement of heat transfer by ultrasonic vibration.

• 한국정밀공학회지
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• 제17권1호
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• pp.27-33
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• 2000

This paper presents a method for determining machining parameters in 3-dimentional electrical discharge machining(EDM). The parameters are the peak value of currents, the pulse-on time, and the pulse-off time. It is known that they influence the performance of EDM more than the other else. The parameters are determined from the discharge area between a tool electrode and a work piece. The discharge area is directly influenced by the geometry of a tool surface and the tool discharge position. The discharge area on a tool discharge position is calculated from intersection curves between the tool surface and a horizontal plane. The grid search method is applied to determine the intersection curves. An example is introduced to show that the machining parameters are obtained from the surface geometry of a tool electrode.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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• pp.411-416
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• 2000

Cutting process has been automated by progress of CNC and CAD/CAM, but polishing process has been depended on only experiential knowledge of expert. To automate the polishing process, a polishing robot with w degrees of freedom which is attached to a machining center with 3 degrees of freedom has been developed. This automatic polishing robot is able to keep the polishing tool normal on the curved surface of die to improve a performance of polishing. Polishing task for a curved surface die demands repetitive operation and high precision, but conventional control algorithm can not cope with the problem of disturbance such as a change of load. In this research, a new sliding mode control algorithm is applied to the robot. The signal compression method is used to identify polishing robot system. to obtain an effect of 5 degrees of freedom motion, a synchronization between the machining center and polishing robot is accomplished by using M code of machining center. And also a trajectory for polishing the curved surface die by 5 degrees of freedom motion, a synchronization between the machining center and polishing robot is accomplished by using M code of machining center. And also a trajectory for polishing the curved surface die by 5 axes machining center is divided into data of two types for 3 axes machining center and 2 axes polishing robot. To evaluate polishing performance of the robot. various experiments are carried out.

• 한국생산제조학회지
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• 제9권3호
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• pp.96-102
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• 2000

High speed machining aims to raise the productivity and efficiency by making more precise and higher value-added products than any other machining method by means of the high speediness of spindle and feed drive system. The purpose of this study is to investigate the effects of the run-out of endmill on the dimension precision of workpiece and to obtain the fundamental data on high speed machining which is available by machining the side of Al-alloy with solid carbide endmills in high speed machining center and by measuring dimensions and surface roughness. From the results of experimentation following are obtained ; if spindle speed is ultra high in conditions that radial depth of cut and feed per tooth are very small highly precise and accurate products are to be made efficiently with high feed rate. and so we can raise productivity.