• Journal of the Korean Society for Precision Engineering
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• v.21 no.2
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• pp.177-185
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• 2004

The machining performance of wire electrical discharge machining(WEDM), such as cutting speed, surface roughness and straightness depend on the electrode, and the machining parameters are diverse and affect each other. Therefore operator must have a lot of experiences of the parameter for the better machining performance in WEDM. An approach to minimize the time for determining of parameters setting is proposed. Based on the Taguchi method, the significant factors affecting the machining performance are determined. Types of electrodes are arranged at inner array in tables of orthogonal arrays so that we can estimate machining performances of each electrode. Coating wire shows better performances than brass wire in cutting speed but it produces poor surface roughness, and two wires shows similar performance in straightness

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.324-328
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• 2002

Recently, in machining industry much progress has been made by taking advantage of high speed machining. On the other hand as disadvantage high speed machining involves shortening the life of cutting tool. In this research we want to evaluate the performance of appropriate endmill for high speed machining in accordance with surface roughness of land width and clearance angle of flat-endmill

• Journal of Mechanical Science and Technology
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• v.16 no.1
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• pp.46-59
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• 2002

The main purpose of this study is to investigate the variation of tool electrode edge wear and machining performance outputs, namely, the machining rate (workpiece removal rate), tool wear rate and the relative wear, with the varying machining parameters (pulse time, discharge current and dielectric flushing pressure) in EDM die sinking. The edge wear profiles obtained are modeled by using the circular arcs, exponential and poller functions. The variation of radii of the circular arcs with machining parameters is given. It is observed that the exponential function models the edge wear profiles of the electrodes, very accurately. The variation of exponential model parameters with machining parameters is presented.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.1 no.1
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• pp.48-54
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• 2002

In industrially advanced countries, environmentally conscious machining was eagerly studied because of ecological and economical reasons. As the environmental regulations become stricter, new machining technologies which take environmental aspects into consideration are being developed Industry and research institutions established applications for dry, semi-dry, oil-mist and compressed cold air machining. This paper investigates the performance of new compressed cold air system for environmentally conscious machining and evaluates machinability of dry and new compressed cold air machining. A series of tests are carried out using measuring eqipments under dry and compressed cold air machining.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.1008-1011
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• 2002

In industrially advanced countries, environmentally conscious machining was eagerly studied because of ecological and economical reasons. As the environmental regulations become stricter, new machining technologies which takes environmental aspects into consideration are being developed. Industry and research institutions established applications for dry, semi-dry, oil-mist and compressed cold air machining. This paper investigates the performance of new compressed cold air system for environmentally conscious machining and evaluates machinability of dry and new compressed cold air machining. A series of tests are carried out using measuring equipments under dry and compressed cold air machining.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.13 no.2
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• pp.127-132
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• 2004

In industrially advanced countries, environmentally conscious machining was eagerly studied because of ecological and economical reasons. As the environmental regulations become stricter, the new machining technologies which take environmental aspects into consideration are being developed. Recently the research institutions have established application method for dry, semi-dry, oil-mist and compressed cold air machining. In this paper the performance of new compressed cold air system for environmentally conscious machining is investigated and machinability of dry and new compressed cold air machining is evaluated. A series of tests are carried out by using measuring equipments in condition of dry and compressed cold air machining.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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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.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.3
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• pp.100-106
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• 1999

Owing to the complexity of electrical discharge machining (EDM) phenomenon, it is very difficult to determine optimal machining parameters fer improving machining performance. This paper proposes a methodology for determining optimal electrical discharge machining parameters, which is maintaining suitable current density for increasing productivity or improving surface roughness. Machining area is closely related on optimal machining parameters in electrical discharge machining process, so calculation of machining area is needed in order to determine optimal machining parameters. In this study machining area, which is corresponding to the machining position, is calculated from intersection curves between the tool surface and a horizontal plane.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.1 no.1
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• pp.38-47
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• 2002

Machining quality has been improved with the development of cutting tools. However, it is difficult to obtain a high degree of quality in machining a deep pocket with a long end mill, since machining accuracy is mainly dependent on the stiffness of the cutting tool and tool holder. To improve machining quality in machining a deep pocket using an end mill, the performance by cutting condition compare with others. Owing to this problem, it is necessary to select suitable tool and holder in the deep pocket machining. In this study, the hydraulic holder for the high speed machining is introduced and the performance of that is compared with others according to cutting conditions. The cutting parameters involved were; slenderness ratio in the range of 3 to 6 (L/D), radial depth of cut from 0.01 to 0.05 mm. Cutting force and surface roughness, precision of form were observed during the experiment to investigate cutting state.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.963-966
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• 2000

Abrasive jet machining(AJM) process is similar to the sand blasting, and effectively removes hard and brittle materials. AJM has applied to rough working such as deburring and rough finishing. As the needs for machining of ceramics, semiconductor, electronic devices and LCD are increasing, micro AJM was developed, and became the inevitable technique to micromachining. This paper describes the performance of the micro AJM in micro groove cutting of glass. Diameter of hole and width of line in this groove cutting is 80${\mu}{\textrm}{m}$. Experimental results showed good performance in micro groove cutting in glass, but the size of machined groove was increased about 2~4${\mu}{\textrm}{m}$. therefore, this micro AJM could be effectively applied to the micro machining of semiconductor, electronic devices and LCD parts.