• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.6
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• pp.9-14
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• 2007

In this paper, a rotating tool clamping device was developed based on a shape memory alloy(SMA) and its feasibility as a tool holder was experimentally explored. The SMA-based device was able to alter clamping to unclamping through temperature control within 1 second. The means and repeatability(${\sigma}$) of the tool clamping force were 185.5N and 6N respectively and its drifts were less than 3% for an hour. Considering the temperature hysteresis of the SMA-based tool clamping device, it is necessary to heat the SMA ring to around $50^{\circ}C$ after tool change to obtain more clamping force.

• Korean Journal of Computational Design and Engineering
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• v.15 no.5
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• pp.354-361
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• 2010

The paper presents an efficient computation of optimal tool length for 5-axis mold & die machining. The implemented procedure processes an NC file as an initial input, where the NC data is generated by another commercial CAM system. A commercial CAM system generates 5-axis machining NC data which, in its own way, is optimal based on pre-defined machining condition such as tool-path pattern, tool-axis control via inclination angles, etc. The proper tool-length should also be provided. The tool-length should be as small as possible in order to enhance machinability as well as surface finish. A feasible tool-length at each NC block can be obtained by checking interference between workpiece and tool components, usually when the tool-axis is not modified at this stage for most CAM systems. Then the minimum feasible tool-length for an NC file consisting of N blocks is the maximum of N tool-length values. However, it can be noted that slight modification of tool-axis at each block may reduce the minimum feasible tool-length in mold & die machining. This approach can effectively be applied in machining feature regions such as steep wall or deep cavity. It has been implemented and is used at a molding die manufacturing company in Korea.

• The Journal of the Korea Contents Association
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• v.4 no.3
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• pp.1-11
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• 2004

This study alms to perform Business Process Reengineering and to develop tourism statistics information system through the development of tourism statistics process design supporting tool. With this tool, we can manage tourism statistics systematic and integrated. Also it offers a tourism decision making supporting tool. Tourism statistics process design supporting tool consists of information provider, information maker, and information user. This tool can improve bossiness process, and rationalize system architecture. 49 business processes were designed and a database which connected with outside system was designed by this supporting tool. By these means, this tool provide more reasonable and effective decision making tool, when it comes to plan tourism development.

• Tribology and Lubricants
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• v.28 no.3
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• pp.130-135
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• 2012

This study presents a new methodology for realtime tool breakage detection by sensor fusion concept of two hall sensor and an acoustic emission (AE) sensor. Spindle induction motor torque of CNC Lathe during machining is estimated by two hall sensor. Estimated motor torque instead of a tool dynamometer was used to measure the cutting torque and tool breakage detection. A burst of AE signal was used as a triggering signal to inspect the cutting torque. A significant drop of cutting torque was utilized to detect tool breakage. The algorithm was implemented on a NI DAQ (Data Acquisition) board for in-process tool breakage detection. The result of experiment showed an excellent monitoring capability of the proposed tool breakage detection system. This system is available tool breakage monitoring through internet also provides this system's user with current cutting torque of induction motor.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.4
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• pp.142-151
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• 1993

An intelligent mulitiple monitoring system to monitor tool/machining states synthetically was proposed and developed. It consists of 2 fundamental subsystems : the multiple sensor detection unit and the intellignet integrated diagnosis unit. Three signals, that is, spindle motor current, Z-axis motor current, and machining sound were adopted to detect tool/machining states more reliably. Based on the multiple sensor information, the diagnosis unit judges either tool breakage or degree of tool wear state using fuzzy reasoning. Tool breakage is diagnosed by the level of spindle/z-axis motor current. Tool wear is diagnosed by both the result of fuzzy pattern recognition for motor currents and the result of pattern matching for machining sound. Fuzzy c-means algorithm was used for fuzzy pattern recognition. Experiments carried out for drill operation in the machining center have shown that the developed system monitors abnormal drill/states drilling very reliably.

• Journal of Internet Computing and Services
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• v.11 no.1
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• pp.143-151
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• 2010

According to increasing requirements in embedded systems. embedded software has been more complicated then before. a optimum software is difficult in embedded system. software developer make a difficult optimum software. this paper suggests a software profiling tool with which a software developer can easily profiling the embedded system software in cross-development environments. the suggested tool is designed based on host/target architecture. this tool insert program source for make profiling log to target program. a target program executed in target system. a target system communicate profiling log to host system. this tool in host system analyze profiling log data. and make a XML of profiling log and a profiling report. a profiling report is graphic viewer based GUI. a target system in this tool needs a few computing power. and XSLT can conversion of profile log XML to other format data. and suggested tool based on eclipse plug-in, therefore developer can use operates in eclipse.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.4
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• pp.79-88
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• 1998

This study deals with the development of CAM system which can machine and measure any shape of mold and die by machining center and coordinate measureing machine . The overall goal of the CAM system is to achieve the mold and die machining , from digitizing through to final cutting. The hardware of the system comprises PC and machining center. CMM. There are three steps in the mold and die machining. (1) measuring of physical model by the CMM, (2) geometric modeling by the CAD system, (3) generation of NC code by the tool path compensated for tool radius. It is developed a software package, with which can conduct a micro CAM system in the PC without economical burden.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.1
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• pp.15-22
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• 2002

This paper introduces a compensating system for machining error, which is resulted from chucking with separated jaws. In machining the chucked cylindrical workpiece, the deterioration of machining accuracy, such as out-of-roundness is inevitable due to the variation of the radial compliance of the chuck workpiece system which is caused by the position of jaws with respect to the direction of the applied force. To compensate the chucking compliance induced error, firstly roundness profile of workpiece due to chucking compliance after machining needs to be predicted. Then using this predicted profile, the compensated tool feed trajectory can be generated. And by synchronizing the cutting tool feed system with workpiece rotation, the chucking compliance induced error can be compensated. To satisfy the condition that the cutting tool feed system must provide high speed and high position accuracy, brushless linear DC motor is used. In this study, firstly through the force-deflection experiment in workpiece chucked lathe, the variation of radial compliance of chuck workpiece system is obtained. Secondly using the mathematical equation and cutting experiment result, the predicted profile of workpiece and its compensation tool trajectory are generated. Thirdly the configuration of compensation system using linear motor is introduced, and to improve the system performance, PID controller is designed. Finally the tracking performance of system is examined by experiment. Through the real cutting experiment, roundness is significantly improved.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.8
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• pp.73-81
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• 1997

The hard turning process defined as a single point turning of materials harder than $H_{R}$C 58 differs from conventional turning because of hardness of the work materials and cutting toos needed in the process. In hard turning, tool life is very short, of the order of a few minutes, during which the cutting tool is subjected to the extremes of stress and temperature. In this regard, it is well known that CBN tool is proper for this process in spite of expensive cost. In this research, we studied the feasibility of the use of the low cost cutting tool such as a aTiN coated tool. To this end, a new cooling system was designed with an air-oil method for reducing tool temperature, which is based on the principle of air vortex flow. That is, the outlet temperature of the air becomes aver 20 .deg. C lower than atmosphere temperature by entering pressurized air of 5kgf/c $m^{2}$ into the inlet. This cooled air ejected to the top of the cutting tool lowered tool temperature, which reduced the wear of a TiN coated tool by the 30% of CBN tool life with respect to the same cutting length.h.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.58-62
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• 1996

In case of hard turning, tool wear is acclerated by heat. So we intend to decrease tool wear by using an air-jet cooling system. Before constructing the air-jet cooling system, no chipping conditions were selected through a statistical method, so called 'Taguchi method', and then the air-jet cooling system was developed by synthesizing and analyzing the results of experimental data through Taguchi method. The air-jet cooling system actually reduced flank wear of TiN coated tool by 25%.