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Tomohiro Nakatsu, Shohei Yokoyama, Takahiro Asai, Yuji Nishiyasu, Kazu ...
2021 Volume 52 Issue 4 Pages
732-737
Published: 2021
Released on J-STAGE: June 04, 2021
JOURNAL
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In this study, using carbon particles as model soot, we examined whether SiC sponge could be used as a gasoline particle filter (GPF), Byusing the microscope, we visualized the particle filtration region. This time, we tested the combination of sponges with different pore sizes anddiscussed the filtration phenomena. It was found that low pressure drop was realized by combining sponges. The pressure drop increased and thefiltration efficiency decreased with increasing SV (space velocity), and the filtration efficiency didn’t reach 100% even when the filtration timewas 600 minutes. Moreover, particles were deposited from the edge of the pore towards the center, and particles were preferentially collected inthe sponge placed upstream.
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Ryoichi Saito, Nao-Aki Noda, Yoshikazu Sano, Jian Song, Takeru Minami, ...
2021 Volume 52 Issue 4 Pages
738-743
Published: 2021
Released on J-STAGE: June 04, 2021
JOURNAL
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In this paper, the fatigue strength of the roller chain is investigated by varying the press-fitting ratio between the pin and the plate. A single plate specimen with two pins press-fitted into two holes at the plate ends is used in the fatigue test. The FEM analysis is performed to obtain the stress amplitude and the average stress on the fatigue endurance limit diagram. The results show that the fatigue strength can be improved under suitable press-fitting ratios δ/D=2.5×10
-3, 5.1×10
-3, 9.5×10
-3 compared to the fatigue strength under press-fitting ratio δ/D=0.
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Isamu Shiotsu, Makoto Kusakabe, Yasumitsu Osada, Yu Nozawa, Teruhiko N ...
2021 Volume 52 Issue 4 Pages
744-749
Published: 2021
Released on J-STAGE: June 04, 2021
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This paper proposes a novel dog brake for an electric vehicle (EV) drive system that combines a dual motor and a planetary gear set. This brake can be in one of the following three states: 1. An engaged state for single-motor drive, 2. A disengaged state for dual-motor drive, 3. A stand-by state for changing the drive mode from single- to dual-motor drive. The dual-motor EV drive system with the proposed dog brake can expand the operating region compared to the previous drive system. Moreover, the proposed dog brake absorbs the energy of the rotating parts, because the timing of brake engagement is controlled when the EV drive mode changes. The results of these study indicated that when the drive mode was changed, the driving torque gap was reduced by up to 62% by control of the engagement timing.
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-Possibilities of CO2 reduction and energy substitution on inter-city logistics-
Masakazu Sasaki
2021 Volume 52 Issue 4 Pages
750-755
Published: 2021
Released on J-STAGE: June 04, 2021
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In case of H. D. Trucks for the mainly use in inter-city logistics, electrifications(xEV) of this type of vehicle have been difficult because of a lack of batteries with long life and great energy capacity. However, significant CO
2 reduction and the shift to sustainable energy use are today’s urgent issues. This paper reports a synergy effect on HV/PHV systems combined with H.D. diesel advancement and technical and economical issues of EV systems for inter-city driving H.D. trucks. The second report will describe a technical and economical possibility including suitable battery life and performances for inter-city driving H.D. xEV trucks.
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-Economical potentiality of electrification of HD Trucks with battery advancement-
Masakazu Sasaki
2021 Volume 52 Issue 4 Pages
756-762
Published: 2021
Released on J-STAGE: June 04, 2021
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In case of H. D. Trucks for the mainly use in inter-city logistics, electrifications(xEV) of this type of vehicle have been difficult because of a lack of batteries with long life and great energy capacity. In the future, batteries will highly be advanced from the aspect of energy density and cost. This paper reports estimated possibilities of a battery life-time extension, reductions in life-cycle cost and battery mass by using future batteries. And it also reports xEV’s economical advantages of battery life-cycle and fuel/electric power costs compared with Diesel Trucks. HV Trucks are further expected to be more economical. EV trucks are to be less and less economical without technological innovation.
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Nobunori Okui
2021 Volume 52 Issue 4 Pages
763-768
Published: 2021
Released on J-STAGE: June 04, 2021
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Real driving emission (RDE) testing method is adopted for Light-duty vehicles. In the future, RDE testing method will be also adopted for Heavy-duty vehicles. However, it is difficult for Heavy-duty vehicles to estimate by using RDE testing method. The reason is that the Heavy-duty vehicles have a lot of vehicle family and vehicle type. Therefore, we considered the alternative test method of RDE for Heavy-duty vehicle by using conventional engine bench system. In this report, we estimated the alternative test method of RDE, which adopted Extended-HILS and Cooling fan system.
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Yusuke Toda, Haruki Saito, Takeshi Toi
2021 Volume 52 Issue 4 Pages
769-774
Published: 2021
Released on J-STAGE: June 04, 2021
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A new sound improvement method is examined focused on the difference in combustion noise in each cylinder of the diesel engine. First, the impression change of the variation that occurs in each cylinder is grasped by subjective evaluation. Next, sound quality analysis is performed to identify the relationship between the features that represent variations and the sensibilities. In addition, a multiple regression analysis is performed using the evaluation results, and a comfort estimation model for variation among cylinders is constructed. Finally, based on the constructed estimation of a simple model that imitates the cylinder block is changed by computer aided engineering.
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Yuichi Shibata, Masanori Kito, Hiroyuki Ishida, Yugo Goto, Masayoshi K ...
2021 Volume 52 Issue 4 Pages
775-781
Published: 2021
Released on J-STAGE: June 04, 2021
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The road projection lamp is currently being discussed internationally as a future automotive lighting technology. We report the required performance of road projection lamp for vehicle reversing. We conducted experiment at outside that simulated the ambient illuminance and the arrangement of lamps, and the ease of awareness and comprehension by the research subjects 24 people was evaluated. In particular both the required luminous intensity for recognizing of 3 light pattern projection and sensory evaluation of them were measured. As a result, the flash and sequential projection was superior in terms of visual perception. And sequential projection is best projection pattern by sensory evaluation.
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Jongseong Gwak, Kazuyoshi Arata, Masaya Kobayashi, Yoshihiro Suda, Tak ...
2021 Volume 52 Issue 4 Pages
782-787
Published: 2021
Released on J-STAGE: June 04, 2021
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A sitting comfort in the indoor environment of a car affects the relaxation and comfort of drivers and passengers. In this study, we aim to improve the sitting comfort of passengers due to the adjustment of the seat parameters during short term automated driving with focused on a dynamic environment. A scenario that replicates automated driving on a highway with straight lines and curves was reproduced using the driving simulator with a motion base. The results showed the reclining and side supporting can improve the seat comfort in the dynamic environment with automated driving.
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Michiaki Sekine, Yuto Sawama, Megumi Enomoto, Yoko Kato
2021 Volume 52 Issue 4 Pages
788-793
Published: 2021
Released on J-STAGE: June 04, 2021
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We tried to quantify the work effort of secondary activities (SA), carried out during automated driving, to predict the takeover time from the metric. Participants were asked to continuously perform a surrogate reference task (SuRT) on a hand-held device (smartphone), or on a fixed display, during automated driving, and to take over immediately after a request signal was presented. In parallel with the SuRT, they were also required to press a button at hand when they detected visual or tactile stimuli (detection response task: DRT). DRT response time is considered to vary according to the degree of effort associated with the SA. As a result, the takeover time for the hand-held device was longer than that for the fixed display. However, it was difficult to clearly confirm this tendency from the DRT response times obtained. It was suggested that there are restrictions to the types of tasks to which DRT can be applied.
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Akinari Hirao, Tomotaka Igarashi, Hiroyuki Nakajima
2021 Volume 52 Issue 4 Pages
794-799
Published: 2021
Released on J-STAGE: June 04, 2021
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In a vehicle, many switches having different operation modes are located around the cockpit. In order to realize a high-quality operation feeling with these switches, we evaluated the operation feeling of three types of switches, push, dial, and pull, which have different operation modes, and determined the optimum switch physical characteristics. Regarding these, we consider the difference in operation and characteristics.
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Hiroshi Uno, Ko Koga, Shinpei Sato, Masaaki Abe
2021 Volume 52 Issue 4 Pages
800-807
Published: 2021
Released on J-STAGE: June 04, 2021
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Four kinds of experiments were carried out using a driving simulator to extract factors degrading the driver's behavior while performing in-vehicle voice control tasks. The following characteristics of voice control tasks increase fluctuations of vehicle lateral position and headway: (1) speech recognition system error in contrast with a relatively small response delay impact, (2) combined use of visual display presenting much information, (3) long task duration, and (4) task demands on the driver for remembrance and/or calculation. Moreover, the headway fluctuation was more sensitive to the aforementioned influences than the vehicle lateral fluctuation. The results revealing the possible elements that impede the driver's behavior would help further improve voice control tasks by eliminating these from the tasks.
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Tetsu Yasui, Osamu Murata
2021 Volume 52 Issue 4 Pages
808-813
Published: 2021
Released on J-STAGE: June 04, 2021
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The effect of a moving ground and rotating wheels on transient aerodynamic loads acting on a hatchback car model in pitching motion were investigated by dynamic wind tunnel tests. The results showed that phase differences of the lift force and the pitching moment became smaller with respect to the pitch angle of the model, and the gain of the lift force became larger with the moving ground and rotating wheels. CFD results revealed that these changes in transient aerodynamic characteristics could be attributed to changes in flow fields under the center floor and the rear wheelhouses.
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Masaaki Kuwahara, Masaaki Sugimoto, Takashi Nakashima, Shingo Kitayama ...
2021 Volume 52 Issue 4 Pages
814-819
Published: 2021
Released on J-STAGE: June 04, 2021
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This paper describes the benefits of inkjet flexible printed circuit for automobile. Increasing of autonomous driving and electrification, the increasing proportion of electronic components in automobiles raises concerns about environmental load and protection of metal resources in the electronic component manufacturing process. The newly developed electronic circuit manufacturing method, which prints metal nanoparticles only on the required area of the substrate surface, reduced the mass of copper by 60% and the mass of waste liquid by 92% compared to the conventional specifications. The vehicle-mounted lighting system made up of inkjet flexible printed circuit has reduced the number of parts by 88% and the mass by 54% compared to the conventional specifications.
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Yoshiya Inoue, Taizo Kitada, Yoshihiro Sugata, Ryota Asakura, Kai Kiku ...
2021 Volume 52 Issue 4 Pages
820-825
Published: 2021
Released on J-STAGE: July 21, 2021
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Super lean combustion, which is free from nitrogen oxide emissions, has been desired to improve fuel efficiency of gasoline engines. In this study, strong tumble flow was generated by a tumble adapter, and the feasibility of the super lean combustion using the enhanced in-cylinder flow was investigated. The enhanced flow under the super lean condition brought a delay between the ignition and the start of the heat release. So observations of the initial flame kernel growing and their image analyses were performed in order to make this event clear. The details of these findings are described in this paper.
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Daichi Suwa, Hironobu Shinohara, Mikiya Araki, Palencia Juan C. Gonzal ...
2021 Volume 52 Issue 4 Pages
826-832
Published: 2021
Released on J-STAGE: July 21, 2021
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In-cylinder inhomogeneity in a port-fuel-injected (PFI) spark-ignition (SI) engine at cold start is investigated experimentally. The equivalence ratio distribution in cylinder is described assuming a normal distribution. The standard deviation, the degree of inhomogeneity, is determined based on the exhaust gas analysis. Before experiments, all the experimental setup including fuel is soaked for ten hours at defined soak temperatures. The test engine is driven by using a starter motor at a constant speed of 350 rpm and the fuel is injected once at a certain cycle. Just after the injection, the engine is stopped and the exhaust gas is rapidly confined using a solenoid valve installed downstream the exhaust valve. By using an FID, the exhaust mass of fuel is calculated. Without spark, the amount of fuel trapped in cylinder is measured. With the spark (with combustion), the amount of fuel trapped but not involved in combustion is measured. The standard deviation of equivalence ratio in cylinder is determined so that the exhaust mass of fuel estimated by model consistently reproduce the experimental results. The standard deviation of mixture is shown to be on the order of unity for a conventional configuration of PFI SI engine.
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Koki Yasuma, Mina Tachibana, Tatsuya Maejima, Eriko Matsumura, Jiro Se ...
2021 Volume 52 Issue 4 Pages
833-838
Published: 2021
Released on J-STAGE: July 21, 2021
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In recent years, Computational Fluid Dynamics (CFD) has been widely used in engine development, and it is known that the accuracy of the droplet breakup model has a great influence on the modeling of fuel sprays in CFD. In this laboratory, WAVE-MTAB model is used as a droplet breakup model for gasoline spray and its applicability is verified. However, WAVE-MTAB model was developed for diesel sprays, and it is reported to have limitations in its applicability to gasoline engines that inject relatively low pressure fuel. The purpose of this study is to elucidate the primary breakup form of the fuel spray in the multi-hole injector for direct gasoline injection, and to develop a breakup model that corresponds to the actual phenomenon. In order to visualize the primary breakup process of the fuel spray under low injection pressure conditions, we took enlarged images of the spray near the nozzle hole using a high-speed camera and microscope lens.
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