著者

高見 創

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

pp.19-00295, (Released:2019-12-16)

参考文献数

16

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To shorten the stopping distance of the high-speed trains in case of emergency such as a huge earthquake, the author developed the small-size and light-weight aerodynamic braking device. The device increases an aerodynamic drag force of a train to achieve a high deceleration at the range of over 350 km/h without a friction between rail and wheel. The device is as miniaturized as possible in order to be installed flexibly on the train, whereby many devices with small-size drag panels are appropriately arranged throughout the train roof to obtain higher drag force. A pair of drag panels rotating around a horizontal axis which are connected by the gear can be actuated by the traveling wind without a large-size actuator. The full-scale prototype aerodynamic braking device is designed and manufactured. To examine its aerodynamic characteristics, one or two prototypes are tested on a wind tunnel facility at a maximum flow speed of 400 km/h (111 m/s). It was proven that the response time of motion from the folding position to the braking position took only 0.39 s, and the device could produce the aerodynamic drag of 2.3 kN per one unit at 400 km/h. Detached-eddy simulation (DES) is used to study the flow around a train roof with a large number of devices. The rate of change of the drag coefficient for devices with the staggered arrangement which aims to improve a total drag force of a train is compared against the standard parallel arrangement at U = 360 km/h. The staggered arrangement could increase the total drag coefficients 10.3 percent as compared to the standard parallel arrangement.

著者

松岡 三郎 古谷 佳之 竹内 悦男 蛭川 寿 松永 久生

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.87, no.895, pp.20-00439, 2021 (Released:2021-03-25)

参考文献数

16

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In order to clarify the effect of internal hydrogen on the fatigue life properties of SUS304, SUS316 and SUS316L, tensile tests and low- and high-cycle fatigue life tests were carried out in air at room temperature using 10, 68 and 100 MPa hydrogen-charged specimens. High-cycle fatigue life tests demonstrated that S-N curve (i.e., relationship between stress amplitude, σa, and number of cycles to failure, Nf) of each steel was higher in hydrogen-charged specimen than in uncharged specimen. The increase in fatigue limit, Δσw, with internal hydrogen was 40 MPa in 100 MPa hydrogen-charged specimens, 20 or 30 MPa in 68 MPa hydrogen-charged specimens, and 0 or 10 MPa in 10 MPa hydrogen-charged specimens. Low-cycle fatigue life tests manifested that εta-Nf curve (i.e., relationship between total strain amplitude, εta, and number of cycles to failure, Nf) of 68 MPa hydrogen-charged specimen was nearly coincident with that of uncharged specimen in SUS316L, whereas 68 MPa hydrogen-charging markedly lowered εta-Nf curve in SUS304. The fraction of strain-induced martensite was measured on specimens fractured by tensile tests and low- and high-cycle fatigue life tests. The critical value of the martensite fraction below which 68~100 MPa hydrogen-charging does not cause hydrogen embrittlement, fmH, was 1 % in tensile tests. On the other hand, the fmH value was 9% in low- and high-cycle fatigue life tests. The increase in fatigue limit due hydrogen-induced solid solution strengthening, Δσw, in high-cycle fatigue life tests was expressed as Δσw (MPa) = 15.4 × 237H, where H is the hydrogen content (mass %). In addition, the hydrogen-induced strengthening of stress amplitude, Δσa, and 0.2% proof strength, Δσ0.2, in low-cycle fatigue life tests was expressed as Δσa+0.2 (MPa) = 15.4 × 296H. The results inferred that the contribution of hydrogen to solid solution strengthening was about 10 times larger than that of carbon and nitrogen when compared at the same mass concentration.

著者

西山 直杜 山下 清隆

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.86, no.881, pp.19-00251, 2020 (Released:2020-01-25)

参考文献数

8

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The railway current collection system consists of a line and a pantograph. We take up the problem of the contact loss between a rigid conductor line and a pantograph. In order to avoid the damage on the line surface by the electric ark, it is important to prevent the contact loss. From the series of experiments with an actual pantograph system, an essential model that regards the contact loss as impact oscillations between a rigid conductor line and a pantograph was proposed. This model consists of a spring supported mass and an external exciting source that is pushed against the mass. In this paper, in order to suppress the impact oscillations, we add an oscillatory system coupled to the spring-mass system. Then, we consider the impact oscillations between the excitation source and the main mass in the two-degrees-of-freedom system. We numerically investigate the problems and obtain the bifurcating motions. When the exciting frequency is near the second mode natural frequency in the two-degrees-of-freedom system, the impact oscillations between the main mass and the external excitation source is suppressed. We conducted a series of experiments in order to verify the theoretical results. The experimental results also reveal the suppression of the impact oscillations. The experimental results qualitatively well agreed with the theoretical predictions.

著者

佐藤 理 岩井 裕 吉田 英生

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

pp.18-00365, (Released:2019-02-21)

参考文献数

18

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The purpose of this study is to develop an analytical model of cross-flow heat exchangers with offset strip fins which are usually equipped in the aircraft air conditioning system (so called the environmental control system, ECS). The ECS mainly consists of four cross-flow heat exchanges, i.e., a primary heat exchanger, a secondary heat exchanger, a reheater and a condenser. Because of the special requirements of the design for the aircraft, the primary and secondary heat exchangers are set adjoiningly; the reheater and the condenser are also set adjoingly. Therefore, in both the pairs, the effect of the temperature profile of the upstream component (the secondary heat exchanger or the reheater) on those of the downstream component (the primary heat exchanger or the condenser) should be taken into account for precise prediction of the system. To this end, a core element model was newly proposed in this study. In addition to the effect of temperature profile, phase changes (condensation and evaporation) of water included in the humid air simultaneously occur except for the primary heat exchanger. Regarding these phenomena, the method of sensible heat fraction (SHF) to convert the latent heat into the equivalent sensible heat was introduced, and the global and local SHF models were examined by comparison with the experiments. The prediction by these models were found to agree well with the actual performance of the ECS operations.

著者

山田 崇恭 正宗 淳 寺本 央 長谷部 高広 黒田 紘敏

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.85, no.877, pp.19-00129, 2019 (Released:2019-09-25)

参考文献数

22

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This paper aims to develop a scheme for geometrical feature constraints in topology optimization for Additive Manufacturing (AM) without support structures based on the Partial Differential Equation (PDE) of geometrical shape features. To begin with, the basic concept of topology optimization and a level set-based topology optimization method are briefly described. Second, the PDE system for geometrical shape features is formulated. Here, aspects of the distribution of state variables are discussed using an analytical solution of the PDE. Based on the discussion, a function indicating the extended normal vector including geometrical singularity points is formulated. Third, geometrical requirements of product shape in AM without support structures – the so-called overhang constraint – are clarified in two-dimensions. A way of extending of the proposed concept to three-dimensional problems is also clarified. Additionally, geometrical singularities in the overhang constraint are discussed. Based on the PDE system and the clarified geometrical requirements, the overhang constraint including geometrical singularities is formulated. A topology optimization problem of the linear elastic problem is formulated considering the overhang constraint. A level set-based topology optimization algorithm is constructed where the Finite Element Method (FEM) is used to solve the governing equation of the linear elastic problem and the PDE, and to update the level set function. Finally, two-dimensional numerical examples are provided to confirm the validity and utility of the proposed method.

著者

八髙 隆雄 坂本 智 大谷 忠 印南 輝久

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

pp.17-00128, (Released:2017-08-03)

参考文献数

9

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The radiation shielding effects on the gamma ray with the effective energy Ee = 661.7 keV and X-rays with that of Ee = 74 keV and 38 keV were examined by using the tungsten-mesh (W-Mesh) made of the tungsten wires of 18μm and 50μm, as candidate for radiation shielding materials having breathability and flexibility. The results showed that the radiation shield rate “η” of W-Mesh sample material represented by mass “Ma” per unit area was almost the same value as in that of the tungsten plate and the lead plate, excepted for the irradiation of gamma-ray at the range under Ma = 1 kg/m2. The value of η at the region of less than Ma = 0.3 kg/m2 also transited to the negative range on the gamma ray irradiation. Therefore, we found that use of W-mesh in the region of Ma = 0.3 kg/m2 or below should be avoided.

著者

下野 智史 児玉 斎 鈴木 克幸

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集

巻号頁・発行日

vol.82, no.834, pp.15-00294-15-00294, 2016

被引用文献数

1

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Taylor-made designs are required for golf clubs, in particularly for golf shafts, because the golf equipment have great effects on the performances of players. Our objective is to establish an optimal design method of golf shafts for each player depending on their swing motions. We measured the swing motions with a 6-axis sensor that inserted into the grip end not to prevent normal motions. We analyzed the head motions at the impact using FEM with the swing data, and we tried to figure out the best shaft spec for an optimal impact. The optimization algorithm was followed 4 skilled shaft designers, which means that we had optimized the 4 SPECs in turn as below; 1) Weight, 2) Torque, 3) Flex, 4) EI pattern. As a result, the distance of a subject, a female professional golfer of JLPGA, was improved 11yrd more with the optimized shaft, and she uses the optimized shaft for more than 2 years. Thus our method was proven to be efficacious for some typical players. On the other hand, we were not able to get desired results for another 2 subjects. We believe the causes of undesired results are that some players change their swing motions depending on the shaft spec. We ought to consider the motion adjustment depending on the shaft spec in order to design optimal golf shafts for each player in the near future.

著者

原 辰徳 濱野 雅史 茅野 遥香 佐藤 隆臣 金木 佑介 梅田 靖 中田 登志之 青山 和浩 太田 順

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

pp.20-00192, (Released:2020-10-13)

参考文献数

23

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In the context of recent servitization of manufacturing characterized by IoT, Big data, and AI, we require a data-driven front-loading design of product with service. This paper proposes a design method of service system that encourages co-creation using a structural framework called TriCyPSS (Triple Cycles for Product Service System) from the viewpoints of service chain and continuous provision among client business, my business, and partner business. This paper shows a case study according to the method’s procedure and details notations using a system modeling method called i* (eye-star). Using them, we clarify value in use brought by the service chain and continuous provision as well as data utilization and information circulation. Finally, this paper employs the method together with business planning methods and tools for practical use.

著者

兒玉 学 戸瀬 義久 奥村 一彦 平井 秀一郎

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

pp.20-00183, (Released:2020-11-13)

参考文献数

16

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Electrolyzed water generator can produce acidic and alkaline water from tap water and electric power, and is expected to have applications in the food and medical fields for sterilization, cleaning and disinfection. However, there are still many unknowns about the internal phenomena of the electrolytic water production system, especially the two-dimensional phenomena that have a strong influence on the miniaturization, power saving, and longevity of the electrolyzed water generator. In this study, multi physics modeling of electrolyzed water generator and two-dimensional numerical simulations are conducted to elucidate the fluid, electrochemical, and electrical phenomena in an electrolyzed water generator. The numerical model is built with governing equations from fluid dynamics, electrochemistry, and electrodynamics. The results show that the neutralization reaction with hydrogen carbonate (HCO3-) is an important reaction in electrolyzed water generator, and this reaction divides the anode cell into two regions (low pH region and high pH region), and the electrical conductivity is low in the low pH region. This region with low pH and electrical conductivity extends to the mainstream direction. The current density on the upstream of anode is higher than that of the downstream of anode. This occurs since the region with low electrical conductivity becomes increasingly thicker moving downstream.

著者

朝日 翔太 松井 彩華 田村 哲嗣 速水 悟 井指 諒亮 古川 輝 内藤 孝昌

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

pp.20-00020, (Released:2020-10-20)

参考文献数

15

被引用文献数

1

---

In this paper, we propose a method to predict the failure of factory equipment by machine learning architectures using vibration data. We design the model so that we can predict robustly the failure of the equipment in advance. We use a Gaussian Mixture Model (GMM), a machine learning architecture, to calculate abnormality value which is used for the decision whether the state of the equipment is normal or abnormal by thresholding. We also use Long Short-Term Memory Autoencoder (LSTM-AE), one of the structures of the deep learning algorithm, for feature extraction. LSTM-AE model learns both spatial and temporal patterns which are difficult to capture with conventional machine learning algorithms. We conducted the prediction experiment using vibration data obtained from actual mechanical equipment, to confirm our method can predict the failure more robust than conventional methods. From this experiment, we found that the abnormality value tended to exceed a threshold value before the actual failure, indicating that the failure can be predicted in advance by our method. Besides, when compared with conventional methods, we found that the transition of abnormality and the accuracy of failure prediction were almost the same in all cases, but we also showed that the proposed method has superiority on robustness compared to conventional methods about the transition of abnormality and the setting of the threshold.

著者

安食 拓哉 岡 正徳 橋口 公一

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.82, no.839, pp.16-00029, 2016 (Released:2016-07-25)

参考文献数

22

被引用文献数

4 6

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Elastoplastic analysis of solid structures under cyclic loadings is increasingly required in recent years. To this end, it is necessary to adopt elastoplastic model capable of describing cyclic loading behavior and to employ stress integration algorithm that enables effective and robust calculation. The subloading surface model excluding a purely-elastic domain is capable of describing the cyclic loading behavior in addition to the monotonic loading behavior. The complete implicit stress-update algorithm by return-mapping based on the closest-point projection for the extended subloading surface model is formulated in this article. In addition, the consistent tangent modulus tensor required for the accurate calculation by the return-mapping is formulated in the inverse matrix form. They are implemented into the implicit finite element program through the user-subroutine. We simulate elastoplastic behavior of metals to assess calculation accuracy and efficiency of the proposed algorithm. Numerical experiments for cyclic loading behavior of metals are shown in order to verify the accuracy and the efficiency of the computer program based on the return-mapping and the consistent tangent modulus tensor.

著者

菊池 孝高 木綿 隆弘 河野 孝昭

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.86, no.887, pp.20-00132, 2020 (Released:2020-07-25)

参考文献数

18

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The present paper describes the performance of a micro undershot water wheel for the power generation in a snow drainageway with the Froude number of 2 to 3. In order to optimize the installation conditions of the undershot water wheel and its arc blade, the effects of blade inlet angle β and the submerged blade height hc on the performance of the undershot micro water wheel has been investigated by field test at Shiramine district in Ishikawa Prefecture. Furthermore, two-dimensional computational fluid dynamics (CFD) has been performed using ANSYS Fluent to be shown clearly the flow of inside and outside of the undershot water wheel and its power. The water wheel has a diameter of D = 600 mm and a width of W = 410 mm. In the snow drainageway, the Froude number is Fr = 2.15 to 2.42. The CFD result of the change of the maximum power coefficient CPmax with the blade inlet angle of β agrees with the experimental one qualitatively. In the case of the submerged blade height hc/D = 0.10, the blade inlet angle β has little influence on the power coefficient CP. In the case of hc/D = 0.20 and 0.29, the peak value of the maximum power coefficient is CPmax = 0.37 and 0.27 at β = 18° and 24°, respectively. The relation between the flow in the water wheel and the generation of torque has been clarified by CFD. The negative torque generates at the rotation angle of water wheel θ = 0 ~ 40° because the separated flow from the tip of blade collides against the back of the blade. The positive torque generates at θ = 45 ~ 110° to apply the drag force by the main flow. The positive torque also generates by the water flow passing through the blades for θ = 135 ~ 210°.

著者

大澤 潤 中野 冠

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

pp.14-00071, (Released:2015-01-28)

参考文献数

27

被引用文献数

1

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Popularity of clean energy vehicles (CEVs) are expected in order to reduce CO2 emissions to mitigate the global warming. However, the popularity provides not only environmental but also economic impacts. An EV requires a battery, but does not require the engine parts any more, which will bring a structural change of the auto parts industry. It is necessary to understand the characteristics of parts used in each CEV type and analyze the economic effects before considering the portfolio for introducing CEVs. In this study, CEV types which have a battery or a fuel cell based powertrain system are considered as well as gasoline, diesel or natural gas engines. This paper proposes an economic ripple effect model using the Input-Output Table. Simulation results show economic impacts in Japan in 2020 and 2030 for the target sales of CEVs assumed by the Ministry of the Environment in 2010. For example, simulation results indicates that production amount in Japan in 2030 is expected to decrease about 1.5 trillion yen compared to 2010.

著者

小野寺 誠 針谷 昌幸 金剛 力 新谷 政樹 何 祺 綿貫 啓一

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.85, no.880, pp.19-00138, 2019 (Released:2019-12-25)

参考文献数

23

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We proposed an advanced mesh generation technique that reuses the proven analysis models by similar sub-part search. The purpose of this research is to reduce interactive mesh improvement work time and to comply with the mesh specifications. It is our feature technique to search sub-parts similar to the archived sub-parts of proven models from new design CAD. In this technique, the similar sub-parts are retrieved from a CAD model described by boundary representation and made correspondence relation surface pairs of a retrieval model (proven model) and a target model (CAD of new design). A similarity score is based on the attributed graphs of a retrieval model and a target model. And, this score is calculated by a geometrical similarity and topological similarity. If there is such search noise, unreusing sub-parts must be canceled by interactive operation. This is an obstacle to automation. Therefore, with the goal of eliminating search noise, we developed a technique to improve the accuracy of similar partial shape retrieval. By quantifying the geometric relationships such as concentric circles and face-to-face distance as similarity, high precision could be realized. It was applied to a door switch cover part of an automobile which is a verification model, and it was confirmed that search noises disappeared.

著者

阪山 由衣子 加藤 孝憲 牧野 泰三 近藤 修 Yannick DESPLANQUES Philippe DUFRENOY

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

pp.16-00324, (Released:2017-04-05)

参考文献数

11

被引用文献数

2 1

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Frictional heat is generated on the rubbing surface and various types of thermal localization occur during sliding contact in braking on disk and pad surfaces. Thermoelastic expansion affects the contact pressure distribution due to the frictional heat generation. The surface temperature is sometimes localized, and the thermal behavior causes surface damage. To evaluate this phenomenon, braking tests were conducted and the localized temperature on the disk surface was observed with an infrared camera. The localized temperature was found to correlate with frequency response for contact force variation. To investigate localized temperature on the disk surface, FEM analysis of the braking test was conducted. The FEM analysis method combined with contact analysis and heat transfer/thermal stress analysis was applied. Heat flux distributions were calculated by contact analysis in consideration of the frictional heating introducing the actual contact force and the friction coefficient variation. The disk surface temperature was then evaluated by the coupled heat transfer/thermal stress analysis using the heat flux distributions obtained from the results of contact analysis. The disk surface temperature obtained from FEM analysis almost coincided with that measured during the braking test. Moreover, the new method could greatly reduce the calculation time compared to the method using the contact analysis alone. Therefore, the proposed method is believed to be useful for evaluation of the rubbing surface temperature.

著者

飯島 直紀 渡邉 鉄也 成澤 慶宜

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.86, no.887, pp.20-00010, 2020 (Released:2020-07-25)

参考文献数

9

---

This paper deals with seismic isolation system with nonlinear characteristics for vertical ground motion. The vertical seismic isolation system consists of a rhombus shaped link mechanism, a tension coil spring, and a leaf spring. The restoring force of the system is obtained by the sum of the restoring force of the buckling deformation of leaf spring and the restoring force of the rhombus shaped link. The purpose of this paper is to create design guidelines for seismic isolation system. Random waves were input to the experimental model with nonlinear restoring force, and the reduction effect was about 0.1 times. In addition, the validity of the analytical model was confirmed by comparing the experimental results with the calculated results. By setting dimensionless parameters and performing analysis, combinations of parameters with high seismic isolation effect were clarified. When the seismic isolation object was determined, a guideline on how to design it was given to make the seismic isolation design easier.

著者

菊地 聡 小里 泰章 李 根燮 今尾 茂樹

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

pp.18-00205, (Released:2018-08-02)

参考文献数

8

---

A propeller fan jet with a duct and straightening plates for the purpose of making a high velocity jet at the far away of propeller was experimentally investigated. As a result, following conclusions were obtained. When the duct and the straightening plates are attached to the propeller, the center velocity at the position away from the propeller becomes fast, because the swirl of the jet becomes weak. As the number of plates increases, the center velocity increases. But when the number of plates exceeds a certain value, the center velocity becomes slow. This is similar about the length of the plates. When the plate is tilted, the larger the tilt angle of the plate is, the slower the center speed becomes in the downstream.

著者

伊藤 史斗 長谷 和徳 内田 和男

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.85, no.878, pp.19-00191, 2019 (Released:2019-10-25)

参考文献数

15

---

The frame stiffness in a racing bicycle might influence not only toughness as the frame structure but also performance of an athlete. The purpose of this study is to clarify biodynamic relations between the frame stiffness in a racing bicycle and the physical loads of an athlete by using a forward dynamics simulation model. The human body structure was represented by the 13-rigid-links and 23-degrees-of-freedom model. Based on the theory of multibody dynamics, the frame structure was expressed by combination of 12 rigid pipes, and the frame stiffness was modeled by rotational springs at the connecting joint between the rigid pipes. Spring coefficients were changed according to the thickness of the frame pipes. The pedaling load from the crank was computed by the angular velocity and angular acceleration of the crank. Moreover, the driving force in the bicycle was additionally defined to consider the influence of the frame weight on the human joint load. The human body model was driven by the joint toques to minimize the cost function consisting of the joint loads in the human body and the driving force in the bicycle, and also to keep desired angular velocity of the crank. Validity of the simulation was evaluated by comparing the joint angles and torques with the measured ones. As for the result, the larger stiffness of the frame resulted in smaller the joint loads in the human body, and optimal stiffness would be determined by the balance between the joint loads in the human body and the driving force in the bicycle.

著者

奥茂 洸一 髙橋 祐衣 金 太成 二川 秀史 細井 厚志 川田 宏之

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

pp.19-00029, (Released:2019-06-03)

参考文献数

23

被引用文献数

1

---

Carbon nanotubes (CNT) have remarkable mechanical properties and low density. Since length of the CNT is limited, CNT yarn is regarded as a reinforced fiber of carbon fiber reinforced plastics. However, the CNT yarn does not have remarkable mechanical properties such as the individual CNT. The most popular way for improving the mechanical properties of the CNT yarn is to make composites with polymer such as polyvinyl alcohol or polyimide. If some functional groups such as carboxyl groups are introduced on the surface of CNTs, interaction between the CNTs and the polymer is improved and high mechanical properties will be obtained. In this study, untwisted CNT yarns were prepared by drawing vertical aligned CNTs through a die and functionalized with mixed acid. Mixed acid introduced not only the functional groups but also defects on the surface of CNTs. For reducing the defects, the CNT yarn was graphitized at a temperature of 2800°C before the mixed acid treatment. By the graphitization treatment, crystallinity of the CNT yarn was improved and amorphous carbon was removed. As a result of XPS analysis, a graphitized CNT yarn treated with mixed acid did not contain the functional groups. On the other hand, a graphitized CNT yarn treated with hot mixed acid (90°C) contained the functional groups. Crystallinity of this yarn was 4.5 times higher than the as-received CNT yarn. In addition, as a result of single fiber tensile tests, tensile strength of this yarn was increased by 79 % and Young’s modulus was increased by 173 % compared to the as-received CNT yarn.

著者

後藤 健太郎 村山 英晶

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

pp.19-00034, (Released:2019-06-19)

参考文献数

22

---

The Lean Automobile is a minimalistic tilting personal mobility for urban transportation with the suspension device equipped with a mechanism which converts driver’s actuation force into lean moment. We proposed it as a solution for the urban traffic problems and conduct study of it aiming for societal implementation. Since the most distinctive feature of the Lean Automobile among the other micro mobilities is its lean control method that is enabled by the unprecedented suspension device, we need to focus on the lean motion dynamics in order to verify the feasibility of the lean control left in the hands and feet of the driver. In this paper the process and outcomes of the feasibility study based on the calculations of transient characteristics and the simulations of lean motion is discussed. A newly developed dynamic model which describes the tilting vehicle with the suspension device equipped with the mechanism generates lean moment is used for the calculations and simulations. Through the study we find out the conditions to stabilize weave mode along with the differences between multiple lean control tactics that is allowed by the distinctive suspension device, therefore we get the prospect that there is multiple tactics to stabilize the Lean Automobile’s lean motion along with avoiding rollover.