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Comparative Analysis of Thermally Induced Seizure Regimes between Accelerated Simulation Test and Long Term Vehicle Operation in Metal V-belt CVT

Tokyo City University-Yuji Mihara
Honda R&D Co., Ltd.-Kenji Matsumoto, Tatsuya Tokunaga, Jun Mori
  • Technical Paper
  • 2020-01-0907
To be published on 2020-04-14 by SAE International in United States
Honda is currently developing and operationalizing a measurement device that allows the state of lubrication to be understood by measuring the in-oil particle distribution. This is a new attempt to detect burn-in and abnormal friction in advance, thus making it possible to suspend actual vehicle tests before breakdown and investigate causes. Seizure was therefore simulated, and in-oil abrasion powder was examined. The results showed that a large amount of scale-shaped abrasion powder was produced due to fatigue during normal operation, while little scale-shaped abrasion powder was detected following the simulation test. This suggests that when a high-load test is performed in order to shorten the test time, the test does not simulate driving conditions in the market, because the state of the loads on the sliding surfaces differs from market conditions.
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Analysis of CVT Element Vibration by In-Situ Measurement

Tokyo City University-Yuji Mihara
Honda R&D Co., Ltd.-Kenji Matsumoto, Hideharu Koga, Toshihiro Saito
  • Technical Paper
  • 2020-01-0906
To be published on 2020-04-14 by SAE International in United States
When the belt of a metal pushing-belt CVT is wrapped around the pulleys, vibration is said to be generated from the friction force caused by the elements that make up the belt rubbing against each other. In order to verify this, a small data logger with a triaxial accelerometer (G Sensor) was developed in house, then fixed on a side surface of a movable pulley and measurements were conducted at engine speeds characteristic of actual driving (1500-2500 rpm). The measurement results showed that there is a difference between the average radius of the belt when it is wrapped around the pulley and when it is not wrapped around the pulley, demonstrating that vibration is occurring.
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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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Attainment of High Thermal Efficiency and Near-zero Emissions by Optimizing Injected Spray Configuration in Direct Injection Hydrogen Engines

Tokyo City University-Masakuni Oikawa, Yasuo Takagi, Yuji Mihara
Okayama University-Nobuyuki Kawahara, Eiji Tomita
  • Technical Paper
  • 2019-01-2306
Published 2019-12-19 by SAE International in United States
The authors have previously proposed a plume ignition and combustion concept (i.e., PCC combustion), in which a hydrogen fuel is directly injected to the combustion chamber in the latter half of compression stroke and forms a richer mixture plume. By combusting the plume, both cooling losses and NOx formation are reduced. In this study, thermal efficiency was substantially improved and NOx formation was reduced with PCC combustion by optimizing such characteristics as direction and diameter of the jets in combination with combustion of lean mixture. Output power declined due to the lean mixture, however, was recovered by supercharging while keeping NOx emissions at the same level. Thermal efficiency was further improved by slightly re-optimizing the jet conditions. The results showed that the hydrogen engine can attain near-zero emissions of NOx reduced to the single-digit ppm level with high thermal efficiency close to 50 percent and can thus be truly called a near-zero emission engine.
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Life Estimation of Rolling Bearings Based on the Colors on Sliding Surfaces

Tokyo City University-Yuji Mihara
Honda R&D Co., Ltd.-Yuki Ono, Kenji Matsumoto
Published 2019-04-02 by SAE International in United States
It is experimentally known that the surface color of bearing balls gradually becomes brown during long term operation of the bearings under appropriate lubrication conditions. That exhibits the possibility of an estimation method for residual life of ball bearings without any abnormal wear on the surfaces by precise color measurements. Therefore, we examined what set colors on bearing balls by surface observation using scanning electron microscopy and subsurface analysis using transmission electron microscopy. Results showed that an amorphous carbon layer had gradually covered ball surfaces during operation of the bearings. The layer not only changed ball color but also made overall ball shapes closer to a complete sphere. The report also introduces a uniquely developed color analyzer which enabled color measurements on metallic surfaces, such as the above-mentioned balls.
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Simple Prediction for Fuel Consumption and Cruising Distance of Internal Combustion Engine Vehicles with RFD Method

Tokyo City University-Hideaki Nagano, Memori Ikeda, Itsuhei Kohri
AGC Inc.-Miyoko Oiwake, Yoshiichi Ozeki
Published 2019-04-02 by SAE International in United States
In order to develop various parts and components of vehicles, understanding the effects of their structures and thermal performance on the fuel consumption and cruising distance is important. However, because of the limited information available to parts suppliers, it is not always easy to predict and study vehicle fuel efficiency and cruising range performance under arbitrary driving conditions. In this study, the authors have developed an RFD (Regression Fuel-consumption Diagram) method to predict the cruising performance of internal-combustion engine vehicles (ICEV) based only on the published information given to suppliers by using standard reference vehicles, which had been regressed and identified for control characteristics and fuel consumption diagrams. As an example of the application of the RFD method to realistic situation, the effects of the driving mode and air-conditioning on the fuel consumption of ICEV are studied. Accordingly, it was found that the influence of the air-conditioning load on the fuel consumption differs depending on the driving modes. In addition, for the validation of the standard reference models introduced in the RFD method, the influence…
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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 Development of Measurement System for Piston Ring Sliding Surface Pressure

Tokyo City University-Kazuya Mochizuki, Yosuke Watanabe, Michiyasu Owashi, Yuji Mihara
Published 2018-10-30 by SAE International in United States
The piston rings, the engine sliding parts, are required to further contribute on mechanical loss reduction in order to improve fuel efficiency. However, many cases of the abnormal combustion due to oil upward flow, as well as the increase in oil consumption have been reported. Therefore, elucidation of the mechanism of those phenomena is still an urgent task. It is widely known that the distribution of the sliding face pressure in between the piston ring and the cylinder bore largely influence the oil flow via the sliding face of the piston ring. However, there are many unknown aspects in this field. Therefore, verification of the sliding face pressure during the actual operation is necessary in order to elucidate the mechanism of oil consumption. The thin-film sensor, since it has little influence on shape, is widely used as a measurement method of the sliding face pressure between two different faces, however this method has never been applied to the piston ring in the past. Authors, through the examination of various film deposition methods, succeeded in forming…
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Development of Coaxial Type Thin Film Temperature Sensor with Improved Measurement Accuracy Based on Principle of Thermoelectromotive Force

Tokyo City University-Daijiro Ishii, Yuji Mihara
Published 2018-10-30 by SAE International in United States
In order to verify cooling loss reduction effect of internal combustion engine, method for measuring wall surface temperature and heat flux with high accuracy is required. Various methods have been proposed for measuring the cooling loss from the combustion gas to the combustion chamber wall, newly coaxial type thin-film temperature sensor was developed for wall temperature and heat flux measurement by the authors. This sensor consists of thin-film and body and center wire have three junction positions in the case where three materials are different. Therefore, it is necessary to use the same materials for thin-film and body or thin-film and center wire to make two junction points. In this study, sputtering method that can be formed various kinds of alloy materials and film thickness of 0.1~1μm on the sensor surface was chosen. It was evaluated the influence of differences in thin-film material on wall temperature and heat flux measurement by numerical analysis, as a result, the surface of sensor body (the same material as the combustion chamber) was hot junction by using the same…
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