• 자동차안전학회지
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• 제6권1호
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• pp.33-40
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• 2014

In this study the cylinder liner deformation which is one of the most influencing factors in a diesel engine oil consumption was performed by the finite element analysis on the basic designed structure consisting of the cylinder block, head and liners under the conditions of assembly, thermal and gas loads. Compared with a large number of other cylinder blocks showing remarkable harmonic orders of the liner distortion, results are excellent. Namely. the higher harmonic order amplitudes of the radial liner deformation amount to 1 ~ 2㎛ maximally. The main reason lies in the relatively large wall thickness of the liner which amounts to 8.2% of the bore diameter. Besides, a very stiff and symmetrical cylinder block design in combination with a bolt force introduction approximately 1.5mm below the block top deck have a further share on these results. Therefore excellent low oil consumption can be expected.

• 한국자동차공학회논문집
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• 제11권3호
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• pp.28-38
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• 2003

Finite element analysis of cylinder heat/block compound under assembly, thermal and firing condition were performed. FE model including two cylinders with gasket, head bolts, liners and valve seats was used. FE modeling method and boundary conditions were introduced. Stress distribution and deformation of cylinder head and block under each loading condition were presented. Gasket pressure distribution and bore distortion level were predicted. Measured data of bore distortion was compared with the analysis results. The analysis result showed similar trends with the experimental data. High cycle fatigue analysis on the basis of this result has been performed in order to find the critical areas of the engine assembly.

• 한국기계가공학회지
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• 제18권12호
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• pp.1-6
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• 2019

Aluminum liners used in cylinders are hazardous for human health. In this study, we use a plastic PA liner inside cylinders to solve this problem. Plastic PA liners are widely used in the manufacturing industry in the production of food and beverage containers. We covered the aluminum boss with a plastic liner material and wound the composite fibers over the liner material. To reinforce the dome area, we used low strength / high elongation plastic liner. To predict the performance of the developed product, we conducted structural analyses utilizing the 3D laminated solid element. We verified the soundness of the product by testing the prototype.

• KSTLE International Journal
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• 제6권2호
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• pp.58-64
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• 2005

An OEM driven working group started in January 2004 to elaborate the philosophies, concepts and test procedures for testing piston ring and cylinder liner materials as well as engine oils outside the engine using the $SRV^{(R)}$ test equipment. The different $SRV^{(R)}$ test philosophies in use by OEMs are compiled. The working group focuses on a.) ASTM sequence VIB (Fuel economy by aging oils), b.) friction and wear in the top dead region under mixed/boundary lubrication, c.) extreme pressure load under mixed/boundary lubrication and d.) hydrodynamic friction. Tribological test result and precision data are presented.

• Journal of Welding and Joining
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• 제17권6호
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• pp.62-69
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• 1999

The advantages of Thermal sprayed coatings as a replacement for cast iron liners are reduced weight, better heat transfer and reduced cost. One of the most important performance attributes of a cylinder bore coating is its wear resistance, since it must survive the abrasive sliding of both the piston rings and the piston skirt. In this study, composite powders were prepared by ball milling of Al-13Si-3Mg(wt%) alloy with SiC particles. The concentrations of SiC were 40 and 60wt%. The composite powders were sprayed using Metco-9MB plasma torch. Plasma sprayed coatings were heat-treated at 500℃ for 3 hours. The wear resistances of the plasma sprayed coatings were found to improve with heat treatment and superior to the commercially available G.C.I.(gray cast iron). AlSiMg-40SiC heat-treated coatings showed the best wear resistance in this study.

• International Journal of Naval Architecture and Ocean Engineering
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• 제9권2호
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• pp.199-208
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• 2017

We perform an experiment on lacquer formation with simple test device. The anti-lacquer is one of important issues to increase durability, and to improve performance in the engines because the lacquer formation cause sticking of fuel injection pump, scuffing of cylinder liners, and increase of lubricant oil consumption in the marine diesel engines. We suggest this simple test in order to save enormous experimental cost in marine diesel engines, and in order to have ease in performing the various tests. The influences of the Base Number (BN) of lubricant oils and the sulfur content of fuel oils in the formation of lacquer are investigated. In order to investigate physical and chemical properties of lacquer, we perform a variety of tests such as, visual inspection, EDS. In addition, we investigate adhesion of lacquer by pull-off test quantitatively, and perform dissolution test with dilute sulfuric acid.

• Journal of Advanced Marine Engineering and Technology
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• 제35권6호
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• pp.829-834
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• 2011

본 논문에서는 대형 선박용 디젤 엔진의 실린더 라이너의 마모량을 측정하는 새로운 시스템의 개발에 관하여 소개한다. 제안된 시스템은 LVDT, 온도센서, 실린더 내부의 밝기조절용 LED 및 카메라가 각각 1개씩 부착된 측정부, 계측명령전달 및 측정데이터 모니터링을 담당하는 컴퓨터기반 모니터링부, 측정부의 제어 및 측정데이터의 모니터링부로의 전송을 담당하는 주 제어부로 구성된다. 개발된 시스템의 정도는 1/100 mm 의 측정정도를 갖는 내경게이지의 것과 비교되어진다.

• Restorative Dentistry and Endodontics
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• 제15권2호
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• pp.77-92
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• 1990

The purpose of this study was to evaluate the cytotoxic effects of 6 cavity liners in vitro. Human fibroblasts were cultured in ${\alpha}$-MEM and each liner was manually mixed and filled in glass ring cylinder ($8{\times}8mm$ in diameter, in height). The cylinders filled with the liners were placed in the center of the dish (35mm in diameter) containing 3ml of ${\alpha}$-MEM. Millipore filters (pore size $0.22{\mu}m$) to simulate dentin barrier were also placed between the bottom of cylinder and the dish. Then the culture dishes were stored in 5% $CO_2$ containing incubator for 5 and 10 days at the temperature of $36.6^{\circ}C$. The results of the experiments were analyzed by counting the cells in the period of 5 and 10 days respectively, and were assessed by calculating the cell multiplication rate and the relative growth rate. The experiemntal groups and the control group were compared statistically. The results of the study were summarized as follows: 1. The cell number of Zinc oxide-eugenol was $(4.13{\pm}1.31){\times}10^4$ cells/ml at 5 days and $(4.32{\pm}1.61){\times}10^4$ cells/ml at 10 days. 2. The cell number of Cavitec was ($8.35{\pm}2.87{\times}10^4$ cells/ml and $(10.08{\pm}5.10){\times}10^4$ cells/ml at 5 and 10 days respectively. 3. The cell number of Dycal was $(13.56{\pm}3.89){\times}10^4$ cells/ml at 5 days and $(34.75{\pm}8.85){\times}10^4$ cells/ml at 10 days. 4. The cell number of life was $(11.46{\pm}3.32){\times}10^4$ cells/ml and $(21.92{\pm}6.18){\times}10^4$ cells/ml at 5 and 10 days. 5. The cell number of Base cement was $(13.73{\pm}3.73){\times}10^4$ cells/ml and $(36.68{\pm}5.20){\times}10^4$ cells/ml at 5 and 10 days. 6. The cell number of Dentin cement was $(13.58{\pm}3.90){\times}10$ cells/ml and $(66.95{\pm}24.09){\times}10$ cells/ml at 5 and 10 days. 7. The cell multiplication rate of zinc oxide-eugenol cements was significantly less than that of the calcium hydroxide and glass ionomer cement. (P < 0.05)

• Tribology and Lubricants
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• 제31권3호
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• pp.86-94
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• 2015

We perform lacquer formation experiments with various combinations of marine fuel oils and lubricant oils. We also investigate the influences of base number (BN) in lubricant oil and sulfur content in fuel oil. A dissolution test with 10% dilute sulfuric acid and pull-off force test are accomplished to distinguish whether the residual layers are lacquering or not. The lacquering layers are dissolved by dilute sulfuric acid and have a strong pull-off force. Moreover, the calcium content detected in the residual layers is compared by energy dispersive x-ray spectroscopy (EDS). More calcium is detected in the lacquer layers than in other residual layers. Distillate fuels containing low sulfur levels are more prone to lacquering when mixed with lubricant oil with a high BN. On the other hand, residual fuels with a high sulfur content do not form lacquer. We investigate the effect of mixture volume ratio. The mixture with higher fuel oil content is more prone to generate lacquer. These experiments indicate that a lubricant with an appropriate BN should be used to prevent lacquer forming on the surfaces such as cylinder liners depending on the sulfur content of fuel oil.

• 대한기계학회논문집A
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• 제32권6호
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• pp.465-473
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• 2008

Type II compressed natural gas(CNG) storage vessels for automobiles have been acknowledged for their excellence and have recently become established in local regions. Their supply is not only to automakers in Korea such as Hyundai Motors but they are being increasingly exported. Although the available products have undergone safety evaluations and are certified by an authorized institution they are still short of the optimal design that is possible for such storage vessels. This research investigates the shape and thickness of the dome with the aim of optimizing the type II CNG storage vessels by using a finite element analysis technique. CNG storage vessels can be largely divided into 3 parts namely, the hear part, the cylinder part and the dome part. The head part is designed by means of a hot spinning process and this method is safer than that used in the design of the dome part even though its shape is similar. The thickness of the liners and reinforcing materials was optimized based on the requirements of the cylinder and dome parts. In addition, the shape of the dome, which is most suitable for Type II CNG storage vessels, is proposed by a process of review and analysis of various existing shape, and then conducting a structural stability evaluation to ensure the optimal design plan.