• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.39 no.12
• /
• pp.1265-1273
• /
• 2015

A coal handling machine is a type of equipment used for loading coal, the main material in a steam power plant, along a conveyer belt from a ship, and is placed after the driving chain bucket. However, studies on the boom hoisting cylinder, which is a hydraulic system used to control the angle of the boom based on loading location, indicate that domestic models are insufficient, and are thereby often substituted with a foreign product. In this study, a technique for analyzing the contact pressure in a thick-walled cylinder was established by comparing the contact pressure, which is calculated theoretically based on the results obtained from FEM simulation, and by checking whether the working oil is leaking from the boom hoisting cylinder using a v-seal. In addition, the driving motion was simulated according to the strokes of the cylinder, and the structural stability was verified under the maximum output conditions.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.34 no.7
• /
• pp.919-928
• /
• 2010

Four patterns for width adjustment were studied with an aim to increase the width-adjustment speed in continuous casting. The main goals are to minimize the actuating force of a WAM actuator, to develop a deformation analysis model of a solidified shell in the mold, and to induce the main limit factor for the speedup of width adjustment. On the basis of the width-adjustment experiment, the notable features of four patterns types were considered, and we compared the corresponding actuating forces. For comparing the driving forces of the patterns, during the experiment, the same casting speed was maintained for each pattern. To optimize the parameter of the deformation analysis model of the solidified shell, the experiment results were applied to them. To speed up width adjustment and to reduce the driving force, we controlled the pattern parameters. The most effective pattern was the fast-mode pattern, and the taper was the main parameter that helped reduce the driving forces during the motion of the actuator.

• The KIPS Transactions:PartA
• /
• v.17A no.1
• /
• pp.19-26
• /
• 2010

As standard of living is higher and aging society is coming, it is needed to develop transportation that is easy to use for weak person. To comply with the demands, it is started to make Bi-modal Tram that is on KRRI(Korea Railroad Research Institute)'s hands. This tram has to have good accessibility like bus, be low level from ground like subway, and park accurately so wheel chair's or passenger's foot can't fall into the gap. But Bi-modal Tram have long length, so it need development of All Wheel Steering System. The Bi-modal Tram that have all wheel steering system steer not only the first axle but also the second and third axle from the first axle or articulation angle, and velocity, and so on. At this study, we discuss AWS ECU's development process.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.9
• /
• pp.1-6
• /
• 2018

Hydro-forming technology has spread dramatically throughout automotive industry over the last 20 years. This technology has many advantages for automotive applications in terms of better structural integrity of the parts, lower cost from fewer parts, material savings, weight reduction, lower springback, improved strength, durability, and design flexibility. In this study, various simulation technologies were developed to investigate the formability of hydro-forming components. Through this technology, to establish the effective forming process for appropriate components design, the bending process, pre-forming process, die closing process, etc. were considered for good forming. This paper proposes the forming amount, section length (corresponding to the hydro-forming press capacity), and minimum curvature (curvature effect evaluation according to the hydro-forming pressure) among the considerations in the design of the hydro-forming part. In addition, a design method is proposed for hydro-forming molding by carrying out cross section analysis of a real sub-frame part for automobiles. The effects of pre-bending, axial feed, hydraulic pressure, press load, and friction among the hydro-forming process parameters were analyzed. Therefore, whether these processes are necessary factors for hydro-forming were examined.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.26 no.1
• /
• pp.82-86
• /
• 2016

This paper proposes a method for the immobilization of motorbike brakes in conjunction with near-field communication (NFC) technology in order to meet the increasing demand for security and convenience of motorbike drivers. We thought about the concept of wireless key, NFC security devices and automatic solenoid valve for setting the lock and unlock module. This paper propose the design and development of an innovative anti-theft alarm system for motorcycles using NFC smart devices based on RFID system, the basis of IoT and AES(advanced encryption standard) encryption Algorithm. The design concept is based on NFC communication strategy between the vehicle and owner. To do this concept, we designed motorcycle smart key system with general-purpose NFC system and the automatic solenoid valve for setting the lock and unlock module. First, we designed control unit and NFC card reader for motorcycle smart key system. Then we propose an AES encryption algorithm and prove that the motorcycle key system is controllable by showing the result of implementing and testing, after installing.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.37 no.4
• /
• pp.296-301
• /
• 2001

Electro-Rheological (ER) fluids belong to a class of colloidal suspensions whose global characteristics can be controlled by the imposition of an appropriate external electrical field upon the fluid domain. The ER fluids for smart hydraulic system are a class of colloidal dispersion which exhibit large reversible changes in their rheological behavior when subjected to external electrical fields. This paper presents experimental results on mechanical properties of an ER fluids subjected to electrical fatigues. As a first step, ER fluid is made of methyl cellulose(MC) ingredient choosing 25% of particle weight-concentration. Following the construction of test for mechanical properties of ER fluid, the shear stress, dynamic yield stress and current density of the ER fluids are experimentally distilled as a function of electric field cycles. The mechanical properties test of operated ER fluids are distilled and compared with those of unused ER fluids.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.7 no.2
• /
• pp.59-66
• /
• 2003

A novel application of nano-technology in the field of engineering, called colloidal damper, is investigated. This device is complementary to the hydraulic damper, having a cylinder-piston construction. Particularly for colloidal damper, the hydraulic oil is replacedby a colloidal suspension, which is consisted from a nano-porous matrix with controlled architecture and a lyophobic fluid. In this experimental work, the porous matrix is composed from silica gel, with labyrinth architecture, coated by organo-silicones substances in order to achieve a hydrophobic surface. Water is considered as associated lyophobic fluid. The colloidal damper test rig and the measuring technique of the hysteresis are described. the influence of the hydrophobicity level upon the colloidal damper hysteresis is investigated, for silica gels with similar pores distribution. A certain desired shape of the hysteresis can be achieved by employing mixture of silica gels with different level of hydrophobicity and/or architecture. With these results, it is believed that the proposed damper can be designed and be applied to the desired structure.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2007.11a
• /
• pp.197-204
• /
• 2007

Nowadays, the construction industry is suffering from the decrease of labor productivity caused by the lack of skilled workers and the aging labor forces. The hazardous work conditions and safety problems still exist at the construction sites. The earthwork operation is not the exception. The number of skilled earthwork equipment operators has been rapidly reduced and the equipment needs to be operated in dangerous / hazardous work sites. Thus, through the development of intelligent excavating system, Intelligent Excavating System(I.E.S) research team tries to enhance the safety of work environment, productivity, quality, and payability of the earthwork operation. It is also expected that this research contributes to the development of fundamental construction automation technologies and to the creation a new market sector.

• Textile Coloration and Finishing
• /
• v.29 no.2
• /
• pp.86-96
• /
• 2017

To make uniform pressure distributed over the contact surface was necessary to cold pad batch dyeing machine. In this study, to confirm characteristic of flexibility and the contact pressure distribution through experimental analysis of padder roll were controlled by hydraulic cell. When there were no load pressure only inner pressure, the value of displacement in the center of padder were greater than the end of the padder. The results of this study showed that the padder had the optimum value of inner pressure for uniform contact pressure distribution. Measuring the contact pressure in a padder system were driven by using a pre-scale film. Uniform contact pressure distribution of cell padder were a linearly with load pressure and inner pressure. When the load pressure was less than 8 tons, the inner pressure for the uniform contact pressure was 1~4 bar. The padder roll performance curves proposed in this study were available for practical production environments and various roll designs.

• Journal of the Korea Society for Simulation
• /
• v.25 no.4
• /
• pp.31-42
• /
• 2016

This study aims to identify the core technology for the automatic impact of the auto-sensing breaker that is one of the construction machinery which do not have a notable development success case yet in Korea. The study has been carried out as follows. Firstly, an analysis model was developed after determining the interconnection of pressure receiving area, opening area and port. And then, a simulation of situation that hard rock and soft rock are mixed was carried out to verify if it is possible to switch between long impact mode and short impact mode continuously. Lastly, the dynamic behavior of automatic control valve induced by the change of impact mode was analyzed based on the analysis result to decipher the core principle of automatic impact control.