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Development of a new method to measure the rotational force acting on the piston rings of a gasoline engine

Department of Mechanical Engineering, Tokyo City University,-Kenta Tomizawa, Akemi Ito
  • Technical Paper
  • 2019-01-2366
Published 2019-12-19 by SAE International in United States
Oil consumption of an engine causes particulate matter, poisoning catalysts and sometimes abnormal combustion like pre-ignition. One of the factors of oil consumption is oil transport via a piston ring-gap. Coincident of ring-gaps at a same position may cause an increase in oil consumption. It was assumed that the rotation of a ring in the circumferential direction is affected by cylinder bore shape, piston motion, distribution of ring tension and so on. The force which caused ring rotation was measured by a newly developed cantilever type of load cell which is set in the ring gap. The force was assumed to be closely related to the piston motion.
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Numerical Study on Pressure Generation Mechanism of Oil Film under Oil Control Ring

Department of Mechanical Engineering, Tokyo City University-Koji Kikuhara, Koichi Nishibe, Akemi Ito
Graduate School of Integrative Science and Engineering, Toky-Susumu Degawa, Wataru Kobayashi
  • Technical Paper
  • 2019-01-2361
Published 2019-12-19 by SAE International in United States
To reduce oil consumption in reciprocating engines, many studies have been conducted on the mechanism and control of the upward transport of oil from the sump to the combustion chamber through the gap between the cylinder liner and compression rings, which is the main cause of oil consumption. Our research group has previously conducted experiments and numerical analysis elucidating the behavior of oil around the piston skirt and oil ring that forms the entrance for the upward transport of oil and is important in optimizing the amount of oil. However, many uncertainties remain regarding the pressure generation mechanism of oil under the oil ring and clarification is essential to establish a high-accuracy prediction method for oil consumption. In the present study, we demonstrated the pressure generation mechanism of oil under the oil ring by reproducing the flow field in the gap between the liner and piston skirt/underside oil ring using computational fluid dynamics (CFD). CFD was conducted with a simplified geometric shape model assuming a viscous two-phase (oil-air) flow and the interface between the oil…
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A study of Measurement for Oil Film at the Bearing of the Small End of Diesel Engine Connecting Rod

SAE International Journal of Advances and Current Practices in Mobility

Tokyo City University-Shotaro Suzuki, Shota Yamada, Akemi Ito
  • Journal Article
  • 2019-01-2332
Published 2019-12-19 by SAE International in United States
Downsizing and slowing down of engine speed reduce mechanical losses and improve fuel economy. However, they exacerbate lubrication condition. The oil film thickness of the bearing of the small end of the connecting rod, which was one of the sliding surfaces with the severest lubrication condition in a diesel engine, was measured in this study to clarify the lubrication condition. Optical fibers were embedded in the bearing, and oil film was measured by means of the laser induced fluorescence method. It was found that oil film thickness was affected combustion gas pressure and distortion of the piston pin.
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A Study on the Function of Oil Drain Holes in the Oil Ring Groove of a Piston and Their Effect on Oil Consumption

Tokyo City University-Ken Miura, Takaki Ohashi, Hiroki Hasegawa, Akemi Ito, Koichi Nishibe
  • Technical Paper
  • 2019-01-2360
Published 2019-12-19 by SAE International in United States
Clarifying the mechanism of oil transporting upward at around an oil ring of a piston is necessary for calculating engine oil consumption. This study aimed to clarify the function of oil drain holes in the oil ring groove of a piston. The effect of the oil drain holes in the groove on oil consumption was investigated. Also the pressure balance around the oil ring was measured. It was found that the drain holes in the groove lowered oil consumption. It was assumed that lower pressure in the groove with the drain holes caused less oil flow into the third land.
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A Study on the Feature of Several Types of Floating Liner Devices for Piston Friction Measurement

Tokyo City University-Yusuke Nagano, Akemi Ito, Daisuke Okamoto, Kiyonari Yamasaka
Published 2019-04-02 by SAE International in United States
The friction reduction of a piston/piston-ring assembly is effective for fuel economy of an engine, and a friction measurement method is required for developing low friction pistons, piston-rings and lubricants. Most suitable method for friction measurement for piston assemblies is “floating liner method”. It has load sensors between a floating cylinder liner and cylinder block, and the sensors can detect friction force acting on the liner. Many apparatuses using floating liner method are developed. They are roughly divided to two categories. In one of them, floating liner is supported by load-washers which axis is set parallel to the center line of the cylinder liner. In another type, floating liner is supported by three-component force sensors installed on the side face of the cylinder. In this paper, five types of floating liner devices were compared. The natural frequency, an important design factor because it affects measurement accuracy and the highest engine speed, was investigated for each device. It was found that natural frequency was strongly affected by sensor type and its mounting condition. A simple model…
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A Study on Effects of Low Viscosity Engine Oil and MoDTC on Piston Friction Losses in a DI Diesel Engine

ADEKA Corporation-Noriyoshi Tanaka, Yukiya Moriizumi
Tokyo City University-Akemi Ito, Yusuke Chubachi, Takumi Yamamoto
Published 2015-09-01 by SAE International in United States
The reduction of friction losses is a subject of central importance in a diesel engine. The piston frictions of low viscosity engine oil and molybdenum dialkyl dithiocarbamate (MoDTC) have been measured by floating liner method. It was found that the low viscosity engine oil lower than 5W-30 is not effective against the reduction of friction mean effective pressure (FMEP) related to the fuel consumption. MoDTC showed a good performance against the reduction of FMEP. In the friction measurement points, the reduction ratio of 10W-30 with MoDTC to 10W-30 was greater than that of 5W-30 to 10W-30.
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Friction Measurement of Al-17%Si Monolithic Cylinder with using Newly Developed Floating Liner Device

SAE International Journal of Engines

Tokyo City University-Akemi Ito, Hideyuki Iwasaki
Yamaha Motor Co., Ltd.-Tatsuhiko Sato, Hirotaka Kurita
  • Journal Article
  • 2014-32-0052
Published 2014-11-11 by SAE International in United States
The improvement of fuel consumption is the most important issue for engine manufactures from the viewpoint of energy and environment conservation. A piston-cylinder system plays an important role for the reduction of an engine friction. For the improvement of the frictional behavior of the piston-cylinder system, it is beneficial to observe and analyze the frictional waveforms during an engine operation.To meet the above-mentioned demand, frictional waveforms were measured with using the renewed floating liner device. In the newly developed floating liner device, an actual cylinder block itself was used as a test specimen.The measured single cylinder was an aluminum monolithic type made of hypereutectic Al-17%Si alloy using a high pressure die casting process. The combined piston was a light weight forged piston and a DLC coated piston ring was used. For the measurement, 110cc air cooled single cylinder engine was used.The observed waveforms were considered to be reasonable and proper from the theoretical point of view. A friction mean effective pressure (FMEP) value was also calculated on each measurement conditions. The FMEP was increased with…
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A Study on Oil-Ring Conformability to Cylinder Bore (1st Report)~Development of Measuring Method of Oil-Film Thickness by Using LIF Method

Nissan Motor-Masatsugu Inui, Hirotaka Akamatsu
Tokyo City Univ.-Kazuya Mochizuki, Koji Kikuhara, Akemi Ito
  • Technical Paper
  • 2012-08-0636
Published 2012-10-03 by Society of Automotive Engineers of Japan in Japan
Cylinder bore shape under engine operating condition has much effect on lubricating oil consumption. This study aims at evaluating the conformability of oil-ring on cylinder bore under engine operating condition and clarifying the mechanism of lubricating oil consumption via the oil ring sliding surface. Laser-Induced-Fluorescence method was adopted to the three-piece-type oil-ring, and oil-film thickness was successfully measured. It was found that oil-film became thicker around the bottom dead center. Findings suggested that the cylinder bore shape, the piston tilting and vaporization of oil on the cylinder affected the oil-film thickness at the oil-ring sliding surface.
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A Study on the Effect of Cylinder Bore Deformation and Piston Ring Tension on Oil Consumption of a Gasoline Engine

Seishi Saitoh, Toru Imai, Akemi Ito, Masatsugu Inui
  • Technical Paper
  • 2011-08-0688
Published 2011-10-12 by Society of Automotive Engineers of Japan in Japan
Reduction of piston friction is required to improve fuel economy. Piston ring tension tends to decrease for reduction of piston friction. A decrease in piston ring tension sometimes causes an increase in engine oil consumption. Therefore reduction of oil consumption under using low tension ring is required. In this study, the effect of cylinder bore deformation and piston ring tension on oil consumption was investigated. It was found that the effect of cylinder bore deformation on oil consumption was more significant with the low tension ring.
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A Study on Piston Design for Friction Reduction in Consideration of the Skirt Deformation With the Oil Film~1st Report: Effect of the Oil Film on Piston Skirt Deformation

Hitachi Automotive Systems, Ltd.-Seiichi Sue, Keisuke Kawano, Masaaki Yamazaki, Kazuya Iwata
Tokyo City Univ.-Akemi Ito, Yasushi Nakatake, Hidekazu Suzuki
  • Technical Paper
  • 2011-08-0128
Published 2011-10-12 by Society of Automotive Engineers of Japan in Japan
The strain of the skirt was measured with the strain gauge put in the skirt at the same time as distributing the oil film of the skirt with a single-cylinder engine for visible making the piston skirt. As a result, it has been understood that the oil film distribution influences the strain of the skirt.