• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2003.04a
• /
• pp.388-392
• /
• 2003

As the machine tool industry progresses, the performance of cutting tools also needs to be of good quality and specialized. If the existing metal cutting tool tip is coated properly, its life would be longer and the machining of a difficult-to-cut material also could be possible. For the development of the high quality cutting tool, the applicabilities of TiAIN coating deposited by PVD on the cutting insert were experimentally investigated. The various measurements, such as, SEM micrograph, XRD pattern, AFM surface morphology, and hardness were performed to cross-check the possibility and availability of TiAIN coated tool in the field. The effects of it is successful and we hope to see good results in many fields.

• Journal of the Korean Society for Precision Engineering
• /
• v.7 no.1
• /
• pp.53-62
• /
• 1990

High speed and heavy cutting performed for improving the surface quality and productivity, are often prevented due to chatter phenomena. Chatter is a violent relative vibration between workpiece and tool in machining of metals, and is an important limiting factor of production rate and surface quality, and reduces the tool life and the dynamic performance of machine tool itself. In this study, in order to suppress the chatter, a modified tool-post combined with the spring and damper was designed and used in the actual cutting test. The results of this study are summerized as follows; The spring and damper adopted in the modified tool-post have the suppressing effects of chatter, and there exists an optimum combination between spring constant and damping ratio.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.43 no.4
• /
• pp.161-167
• /
• 2020

In the process of cutting large aircraft parts, the tool may be abnormally worn or damaged due to various factors such as mechanical vibration, disturbances such as chips, and physical properties of the workpiece, which may result in deterioration of the surface quality of the workpiece. Because workpieces used for large aircrafts parts are expensive and require strict processing quality, a maintenance plan is required to minimize the deterioration of the workpiece quality that can be caused by unexpected abnormalities of the tool and take maintenance measures at an earlier stage that does not adversely affect the machining. In this paper, we propose a method to indirectly monitor the tool condition that can affect the machining quality of large aircraft parts through real-time monitoring of the current signal applied to the spindle motor during machining by comparing whether the monitored current shows an abnormal pattern during actual machining by using this as a reference pattern. First, 30 types of tools are used for machining large aircraft parts, and three tools with relatively frequent breakages among these tools were selected as monitoring targets by reflecting the opinions of processing experts in the field. Second, when creating the CNC machining program, the M code, which is a CNC auxiliary function, is inserted at the starting and ending positions of the tool to be monitored using the editing tool, so that monitoring start and end times can be notified. Third, the monitoring program was run with the M code signal notified from the CNC controller by using the DAQ (Data Acquisition) device, and the machine learning algorithms for detecting abnormality of the current signal received in real time could be used to determine whether there was an abnormality. Fourth, through the implementation of the prototype system, the feasibility of the method proposed in this paper was shown and verified through an actual example.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.16 no.4
• /
• pp.83-88
• /
• 2017

Recently, the use of advanced materials with light weight significantly increases because of global regulation on CO2 emission. Especially, CFRP (carbon fiber reinforced plastics) one of the most promising advanced materials. Since CFRP has pretty higher strength per unit weight than steel, it is one of most popular materials in aviation industry and its application to automobile rises sharply. Especially, one of the frequent machining processes for CFRP is drilling to make a hole, however, CFRP drilling has troublesome limitations in hole quality and productivity induced due to delamination, splintering and severe tool wear. Particularly, cutting loads increase caused by tool wear makes delamination and splintering even severer. Therefore, tool wear monitoring or reduction in CFRP drilling must be considered seriously. In this study, we measured thrust force, flank wear, and tool surface temperature in drilling using various tools with different sizes and materials. Consequently, it was presented the effects of tool properties on drilled hole quality, thrust force and tool surface temperature.

• Journal of Korean Clinical Nursing Research
• /
• v.16 no.1
• /
• pp.177-196
• /
• 2010

Purpose: This study was conducted to develop the nursing process based performance measurement tool and the evidence based care standards for nursing care in medication management and blood transfusion. Methods: The care standards and performance measurement tool were drafted through comprehensive review of relevant literature, national guidelines, hospital protocols, and standards of recognized international accrediting bodies. The proposed care standards and performance measurement tool were reviewed by the panel of experts and refined based on the panel's suggestions. Final care standards and performance measurement tool were validated by surveying the hospital nurses. Results: All items of the performance measurement tool for medication management and blood transfusion were evaluated appropriate. All contents of care standards and the measurable elements except the evaluation of discharge education were appropriate. The performance measurement tool developed in this study was found to be acceptable as a tool to evaluate quality of nursing care in medication management and blood transfusion. Conclusion: The outcomes of this study including the performance measurement tool and evidence based care standards would be the important indicators to monitor whether necessary nursing care is implemented and be the useful primary resources to improve quality of nursing care services.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2001.10a
• /
• pp.14-18
• /
• 2001

Rise in cutting force causes tool damage and worsens product quality resulting in machining accuracy deterioration. Especially, fragile material cutting brings about breakage of material and worsens product surface quality. In this study, we trace the locus of cutting force and examine the machined surface corresponding to the cutting force loci. and build up a monitoring system for deciding normal operation or not of cutting process.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2000.04a
• /
• pp.507-512
• /
• 2000

Due to increasing demand toward improving product quality, various methodologies have been introduced. A brush type grinding tool is one of the most frequently used one to facilitate required process. In order to produce consistent burr shape, various machining conditions have been combined applied to disk grinding process. It has been observed that the burr dimension(shape and width) depends on the inclination angle between grinding disk and workpiece. Drastic increase of tool Wear has been also observed along the inclination angle variation. Various burr shapes have been captured and analyzed using image processing technique.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.8 no.12
• /
• pp.119-125
• /
• 1985

It is very important to assure the software quality. The static and dynamic testing are to be performed on the program to find some error in it, and it's purposes are to assure the software quality with cost-effectiveness. For it we use the automated tool. In this paper, it suggest the design of the software tool for COBOL static testing.

• International Journal of Precision Engineering and Manufacturing
• /
• v.3 no.1
• /
• pp.76-82
• /
• 2002

This paper presents an experimental study of the effect of cutting tool materials on surface quality when turning hardened steels. Machining tests on a lathe are performed using polycrystalline cubic boron nitride (PCBN) and ceramic tools at various cutting conditions without coolant. From the experiments, it is observed that the radial force is the largest force component regardless the type of tool used. The specific cutting energy for the hard turning is estimated to be considerably smaller than the specific grinding energy. It is also found that cutting force and surface roughness with the PCBN tools are higher and better than those with the ceramic tools under the same cutting condition. It is due that the PCBN tools transfer the generated heat more effectively than the ceramic tools due to their higher thermal conductivity. The optimal cutting conditions for the best surface quality are selected by using an orthogonal array concept.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.21 no.45
• /
• pp.155-163
• /
• 1998

Recently, as the quality is being recognized as elementary and strategic means to improve the international competetiveness of a business, there may be few business who do not operate quality control meeting or system for their production lines. In other words, local businesses operate some types of quality control system half voluntarily and half compulsorily without having verifying their efficiency. Under such a circumstance, this study is aimed at determining the factors which local businesses are required to assess for their quality system. It is believed that the results of this study can be used as a tool for local businesses to assess their quality system. The effective identification of problems regarding the quality system depends on how precisely the activities of quality system can be performed. Upon correct identification of problems, desirable directions can be explored. All in all, the model developed through this study may be useful as quality system assessment tool.