• Design & Manufacturing
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• v.6 no.2
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• pp.12-16
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• 2012

In this study, an injection mold is made to produce polymer line post insulators. FRP (fiber reinforced plastics) is covered by silicone housing. In injection molding process, chances for offcenter are 60 percent. Given the structure of the product, offcenter occurs owing to the imbalances in positions of gates and improper -designs of cores and jigs. This study focuses on mold modifications and improvements.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.311-314
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• 2004

The housing of the fuel injector supports the rod, the niddle valve and the solenoid. Based on the procedure of process design, in this paper, the forming operation is designed by the rigid-plastic finite element method. The metal flow during the forming of the fuel injector housing is axisymmetric until the final forming process. The response surface method has been performed to reduce the under-fill and the maximum effective strain. From the results of RSM, the second order regression model of equation is calculated by the least square method and used to determine the optimal values of design variables by simultaneously considering the responses. It is noted that upper under-fill is affected by the design variables of the $2^{nd}$ forming process and lower under-fill is affected by the design variables of the 1st forming process.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.10
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• pp.1499-1507
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• 2017

This paper presents an impact-based piezoelectric vibration energy harvester using a freely movable metal sphere and a piezoceramic fiber-based MFC (Macro Fiber Composite) as piezoelectric cantilever. The free motion of the metal sphere, which impacts both ends of the cavity in an aluminum housing, generates power across a cantilever-type MFC beam in response to low frequency vibration such as human-body-induced motion. Impacting force of the spherical proof mass is transformed into the vibration of the piezoelectric cantilever indirectly via the aluminum housing. A proof-of-concept energy harvesting device has been fabricated and tested. Effect of the indirect impact-based system has been tested and compared with the direct impact-based counterpart. Maximum peak-to-peak open circuit voltage of 39.8V and average power of $598.9{\mu}W$ have been obtained at 3g acceleration at 18Hz. Long-term reliability of the fabricated device has been verified by cyclic testing. For the improvement of output performance and reliability, various devices have been tested and compared. Using device fabricated with anodized aluminum housing, maximum peak-to-peak open-circuit voltage of 34.4V and average power of $372.8{\mu}W$ have been obtained at 3g excitation at 20Hz. In terms of reliability, housing with 0.5mm-thick steel plate and anodized aluminum gave improved results with reduced power reduction during initial phase of the cyclic testing.

• Journal of Korea Foundry Society
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• v.32 no.5
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• pp.231-240
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• 2012

In present study, the effect of heat treatment on the microstructure and mechanical properties of the gravity cast superchargers housing using A356 alloy were investigated. In order to identify the characteristics of superchagers housing casting with heat treatment, Vickers hardness test, electrical conductivity test, opical and scanning electron microscopy were performed. And also, to investigate their mechanical properties, the T6 treated superchagers housing casting in optimum heat treatment condition were carried out tensile test using UTM (Universal Testing Machine).

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.2
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• pp.306-314
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• 2008

General metal welding occurs distortion. Also, reducing distortion is required much cost. Therefore, the purpose of this study is optimization of welding conditions to reduce distortion in welding of monolithic rack housing for modular steering gear. Firstly, heat source for welding was chosen arc and laser. Secondly, it investigated optimizing welding conditions in bead welding by arc and laser heat source, and welding conditions in fillet welding was optimized with welding shapes. Finally, it was measured temperature distribution of welds by infrared camera and angle distortion in fillet welding. As a result, laser welding was superior to arc welding on distortion.

• Journal of Animal Environmental Science
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• v.15 no.1
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• pp.17-28
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• 2009

PEB system is more economical when compared with structures commonly used Hot rolled and welded light H-beam was introduced in the Standard Livestock Housing. This study suggested more economical technology for structural design by the reduction of live load, relief of deflection limit and reduction of importance factor. And, when applying wind Load as a result of examination with Low Rise Building Systems Manual considering open model, we can know that when the wind load is big, enclosed model is more stable than open model. In short, Suggesting more economical model and providing the method to reduce natural disaster, by the application of PEB system and the development of technology for structural design, are considered to strengthen the competitive power of farmhouse.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.2038-2040
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• 2000

The main objective of this paper is to design and test a new type of polymer ZnO surge arrester for AC power system of railroad vehicles. Metal oxide surge arrester for most electric power system applications, electric train and subway are now being used extensively to protect overvoltage due to lightning. Surge arresters with porcelain housing must not have explosive breakage of the housing to minimize damage to other equipment when subjected to internal high short circuit current. When breakdown of ZnO elements in a surge arrester occurs due to flashover, fault short current flows through the arrestor and internal pressure of the arrester rises. The pressure rise can usually be limited by fitting a pressure relief diaphragm and transferring the arc from the inside to the outside of the housing. However, there is possibility of porcelain fragmentation caused by the thermal shock, pressure rise. etc. Non-fragmenting of the housing is the most desired way to prevent damage to other equipment. The pressure change which is occurred by flashover become discharge energy. This discharge energy raises to damage arrester housing and arrester housing is dispersed as small fragment. Therefore, the pressure relief design is requested to obstruct housing dispersion. The main research works are focused on the structure design by finite element method, pressure relief of module, and studies of performance of surge arrester for electric railway vehicle.

• Korean Journal of Materials Research
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• v.16 no.11
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• pp.668-675
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• 2006

In the partial squeeze casting process, the filling behavior of liquid metal and solidification pattern in thick area have significant influence on the quality of casting products and die life. For the optimal casting design of automobile transmission gear housing, various analyses were performed in this study by using computer simulation code, MAGMAsoft and the simulation results were compared and analyzed with experimental results. By air pressure criteria, internal porosities caused by air entrap during the mold filling were predicted and reduced remarkably by modification of gating system. Also, optimal squeeze-time lag to apply partial squeeze pin in thick area was calculated and the castings was free from shrinkage defects with the result of solidification analysis. Consequently, casting design for automobile transmission gear housing was optimized and approved by Computer Tomography.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.3
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• pp.143-147
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• 2014

The ECU which is operating inductive actuator like motor or solenoid should be designed with considering the heat removal performance and the EMC performance. In most cases, these two performances are trade-off. Especially, the metal cover with plastic housing for improving heat removal performance can affect EMC performance by coupling the noise source to harness cable and connector. Therefore, after analyzing the EMC effectiveness of the metal cover, countermeasures for EMC noise reduction should be established. In this paper, by simulating and testing of AHB Gen3 ECU, the influence of the metal cover to EMC performance is analyzed. And based on this result, we propose solutions for EMC noise reduction.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05a
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• pp.74-77
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• 2000

The main objective of this paper is to design and test a new type of polymer ZnO surge arrester for AC power system of railroad vehicles. Metal oxide surge arrester for most electric power system applications, electric train and must not have explosive breakage of the housing to minimize damage to other equipment when subjected to internal high short circuit current. When breakdown of ZnO elements in a surge arrester occurs due to flashover, fault short current flows through the arrester and internal pressure of the arrester rises. The pressure rise can usually be limited by fitting a pressure relief diaphragm and transferring the arc from the inside to the outside of the housing. However, there is possibility of porcelain fragmentation caused by the thermal shock. pressure rise, etc. Non-fragmenting of the housing is the most desired way to prevent damage to other equipment. The pressure change which is occurred by flashover become discharge energy. This discharge energy raises to damage arrester housing and arrester housing is dispersed as small fragment. Therefore, the pressure relief design is requested to obstruct housing dispersion. The main research works are focused on the structure design by finite element method, pressure relief of module, and studies of performance of surge arrester for electric railway vehicle.