• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.20 no.5
• /
• pp.1468-1476
• /
• 1996

Surface integrity is dictated by the fabrication process of the metal part. In this work, steel specimens were prepared under various mechine conditions to achieve different degrees of deformation state. The tribological characteristics of the speciments were tested using a pin-on-disk type apparatus and other surface characterization tools. It is shown that though frictional characteristics are similar, the wear rate is significantrly affected by the properties of the surface. In the case of steel, surface cracks resulted in high wear despite the relatively high hardness of the specimen. Also, the sliding action were found to reduce the residual stress on the surface. These results indicate that there is a strong relationship between surface integrity and the tribological properties of steel, and therefore the machining condition should be optimized woth respect to tribological performance of a steel part.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.2 no.3
• /
• pp.76-83
• /
• 2003

Recently, the field of the engineering has been studied about optimum design continuously. Verified data by comparison with simulation and dynamic characteristic analysis enables the design of a machine tool to be modified easily and effectively concerning to the mode shape of the vibration. Especially, BC-500 Line Center has got some problems causing vibration which mainly come from Column and ATC part. So it is necessary to solve those problems by the two kinds of method such as changing structural design and reinforcing with ribs. In this paper, column and ATC part of BC-500 Line center are modified by an optimum design by the analysing method of FEM to avoid vibration. As a result, a more stable machine tool was designed by this simulation as optimum condition.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.4 no.4
• /
• pp.48-53
• /
• 2005

This research is materialized the mechanism of a interlocking elevator device to meet with customer's requirement demanding a variety of function. On this suitably theoretical translation and by considering of material significance of the most factor's tension spring and torsion spring, it's compared and reviewed the stress's calculation according that SWC and SWPB applied differently. And also that is approved through actual experiment. Out of a variety of feasible movement. Torque Balance is materialized by combination of tension spring, torsion spring and disk spring. So that application of 3 factors for optimal design is very important factor. In future, this research thesis make sure to play a highly role for application and improvement mechanically in various industry sector out of materializing interlock.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.14 no.4
• /
• pp.100-107
• /
• 2015

Recently, high-efficiency machining in the production of high-value products with a complex shape has constantly been required with the need for hybrid machining. In this study, in addition to the wire-cut E.D.M. and vibration used to present the possibility of a hybrid process by carrying out the aluminum alloy experiment, the hybrid process determines the nature of the surface. The selected experimental parameters are horizontality, waveform, amplitude, peak current, and frequency. The experimental results give guidelines for selecting reasonable machining parameters. The surface roughness was improved by about 20% with increases in the amplitude of the vibration.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.6 no.3
• /
• pp.16-23
• /
• 2007

An experimental investigation with diode laser system was carried out to study the effect of surface heat treatment on the die materials(SM45C, SKD11, SK3). The surface heat treatment characteristics of the laser beam are evaluated using hardness tests, optical microscopy, X-ray diffraction and energy dispersive X-ray spectroscopy(EDS). Results indicated that the beam size, focal length, feed rates are changed surface hardened characteristics. SM45C is higher hardness than other materials and composed to martensite grain at hardened zone, whereas other materials(SKD11, SK3)are low hardness than expected and composed to austenite and allayed martensite at hardened zone. The intensive X-ray diffraction patterns of (110)-(200)-(211) is detected hardened surface and the hardened surface distributed plenty of carbon density than metal zone.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.6 no.1
• /
• pp.13-19
• /
• 2007

The spring is an important mechanical parts to improve the functions of precision machines, automobiles, ships, industrial machines, and IT devices etc.. The hinge mechanism for LCD monitors is very important to support and maintain the proper position of monitor panel, and the tension spring which is a major parts of hinge mechanism plays a significant roll to provide the supporting force positioning the monitor panel. In this paper, an analysis and experiment were carried out to investigate the fatigue characteristics of the tension spring of hinge mechanism, such as hardness test, fatigue test and fractography analysis. As a result of this study the SWPB with heat treatment and shot peening was found to have the optimal design conditions of tension spring for LCD monitor hinge mechanism.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.6 no.3
• /
• pp.92-97
• /
• 2007

The overlay welding the automobile where the durability is demanded, it is used in the vessel engine valve, plant valve and pump parts. Cause of damage public opinion one what is thought is the fatigue load due to the opening and shutting operation right time repetition of the engine valve. The damage cause of the engine valve or explanation of destruction mechanism is very difficult. The research which it sees to make clear a overlay welding of Co-alloy by Plasma Transferred Arc Weld Surfacing Process reconsideration fatigue crack initiation and fatigue crack growth mechanism at high temperature.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.6 no.4
• /
• pp.28-35
• /
• 2007

Currently, most of all valves using at the semiconductor & LCD manufacturing process are packless type. Such valves are needed to have the functions to protect perfectly from the leakage of fluid by using bellows and diaphragm instead of the grand packing. But not only those valves made in Korea are not available at this point, but also advanced foreign manufacturers do not open enough their data on the basic technology. Otherwise although they open the data a little, they are almost data about stainless steel for pneumatic valves. In this paper, it was focused on the fluid valves for chemical & DI water based on the data of steel valves which are already using commercially. And also this study concentrated to collect the basic developing data of Eco-On/Off diaphragm valve by ourselves.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.16 no.5
• /
• pp.198-204
• /
• 2007

This study was carried out to develope a flow control system using to supply PR(photo-resist) in the semi-conductor manufacturing process. The features of this system are to be able to measure the high viscosity and micro-flow. To meet above study object some ideas was induced to design a new concept valve with new material, multi-cross wheel, and new sealing method etc.. As the evaluations on the developed micro-flowmeter it was enough satisfied to use at the IT industries such as photo-resist process.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.11a
• /
• pp.398.1-398
• /
• 2002

A new type actuator has been designed and investigated to overcome thermal problems in slim optical disc drives adopted in mobile storage devices. As the size of optical disc drives decreases, it is more difficult to remove the heat inside a drive and the temperature of an actuator increases. As a result, the second resonance of an actuator moves down to a lower frequency band and the performance of optical parts also deteriorates. (omitted)