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

---

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

---

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

---

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

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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.

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

vol.80, no.820, pp.TEP0360, 2014 (Released:2014-12-25)

参考文献数

9

被引用文献数

4 2

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The purpose of this study is to clarify the effect of a component for high-pressure water separation, which is included in the air conditioning system of the general commercial aircrafts, on the air-cycle operation (reverse Brayton cycle); the high-pressure water separation consists of water separator and two heat exchangers called reheater and condenser, respectively. This paper briefly describes the typical system configuration of the air-cycle refrigeration progressed with evolutions in turbofan engine. Since nowadays, 4-Wheel air-cycle has been a trend on the aircraft air conditioning system, this paper theoretically shows its advantage on the basis of the thermodynamic cycle study. In the following chapters, an analysis was conducted on the interaction between a reheater and a condenser when each heat transfer performance changes from the baseline operating point. Also, the comparative study was made on the system performances by the 3-wheel and 4-wheel air-cycle. In addition, this paper describes how the heat transfer performance is designed for the reheater and the condenser under the system requirements for the entire air conditioning system.

著者

竹内 和也 松島 紀佐 金崎 雅博 楠瀬 一洋

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.81, no.827, pp.15-00037, 2015 (Released:2015-07-25)

参考文献数

9

被引用文献数

3 3

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To systematically investigate the aerodynamic characteristics of wings with 30, 45 and 60 degree swept-back angles, and different taper ratios, Navier-Stokes (N-S) simulations for flows over a wing have been conducted. The Mach numbers of the flows range from 0.8 to 2.8. The planforms of wings are in various shapes whose half span aspect ratios are identically fixed in 2.0. The simulation and investigation has revealed new knowledge on the relation between swept-back angles and aerodynamic characteristics of a wing in a supersonic flow. As the aerodynamic characteristics, drag coefficient CD variation is primarily observed along flow Mach number increase. Results of N-S simulations show a realistic profile of the variation which is substantially different from that by the thin-wing theory commonly printed in a textbook. Moreover, the simulation results indicate not only the swept-back angle of a leading edge but also that of a trailing edge take important role on aerodynamics of a wing. Finely, the effect of drag coefficients induced by lift is analyzed using simulation results. It is found that the induced drag in realistic supersonic flows can be treated by the thin-wing theory if three-dimensionality is properly evaluated.

著者

中川 智皓 森田 悠介 新谷 篤彦 伊藤 智博

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.838, pp.16-00052, 2016 (Released:2016-06-25)

参考文献数

11

被引用文献数

1

---

In recent years, personal mobility vehicles (PMVs) have attracted huge attentions and widely developed. Compact PMVs can move through narrow spaces and they are expected to be used in pedestrian spaces. In this study, we aim to develop a four-wheel stand-up-type personal mobility vehicle for people who cannot walk far distantly because of the pain of foot or waist although they are able to walk for a short distance. The coupled model of human and vehicle is constructed by using multibody dynamics. In the model, the vehicle is expressed by one rigid body. The wheels, body, and handle are considered as a rigid body together. A human is expressed by 8 rigid bodies (foot, lower leg, femoral, body, head, upper arm, lower arm, and hand). The vehicle of the coupled model is accelerated in the numerical simulations. The behaviors of the center of gravity of a human with and without handle constraint are analyzed. As the result of the parametric study, it is found that the center of gravity movement is smaller when the value of the maximum acceleration and the acceleration time are small. It is also found that as the angle of the upper arm becomes large, the movement of the center of gravity is decreased.

著者

沖野 友洋 永田 恵輔 堀川 敬太郎 小林 秀敏

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

pp.19-00249, (Released:2019-12-26)

参考文献数

13

被引用文献数

2

---

The crash safety structure of the railway vehicles is effective as one of the safety measures against the train crews and the passengers in the event of a collision accident. The standards for crashworthiness of railway vehicles are defined in Europe and the U.S., while there are no standards for crash safety in Japan. Therefore, it is important to establish the evaluation method for crashworthiness of railway vehicles considering the actual situation of collision accidents in Japan. The authors carried out finite element analyses of a level crossing accident under various conditions (collision speed, mass of the obstacle and relative position between the train and the obstacle) based on the statistical analysis of serious level-crossing accidents in the past in Japan, and calculated the deceleration time histories in the passenger area under each condition. We evaluated these deceleration waveforms according to European and the U.S. standards for crashworthiness, and we also performed finite element analyses of dummy’s behavior and injury values using these deceleration waveforms as input. We verified the correlation between the evaluation results in terms of the deceleration according to these standards and dummy’s injury values obtained by finite element analyses. As a result, the evaluation according to the velocity at which a passenger contacts the seat back ahead of him (the U.S. standards) was the most effective. Moreover, the integrated values of the deceleration of the passenger area during an integration time t360 had the highest correlation with the dummy’s injury values.

著者

原 進 鈴木 健太 山田 陽滋

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.83, no.855, pp.2017transjsmeE01, 2017 (Released:2019-12-25)

著者

佐藤 拓哉 宮武 昌史

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.19-00092, 2019 (Released:2019-12-25)

参考文献数

13

被引用文献数

1

---

Battery train is in development as train which can travel in non-electrified section using power supplied from onboard storage system such as lithium-ion battery. However, as characteristics of this type of train, an energy consumption of battery train depends on the state of charge of the storage system. In consideration of these characteristics, we propose a generation method of the timetable which is the most energy-saving when a single battery train travels on a route section containing multiple stations in this research. Although this optimization can be defined as a nonlinear programming problem, we ease to solve this problem using linear approximation to the energy consumption characteristic. In the end, we carried out a simulation in a simple case and achieved 4.7% reduction in energy consumption by the proposed method.

著者

岡田 光貴 末岡 裕一郎 中西 大輔 大須賀 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

pp.19-00151, (Released:2019-12-04)

参考文献数

13

---

This paper is concerned with the demonstration of scallop-like swimming with the aid of robot toy; using jet propulsion by clapping the shells quickly. Previous works from biological approach have indicated what structures contributes to generate the jet propulsion. This paper tries to perform quick underwater locomotion by mimicking the structures of scallop based on constructive approach: development of scallop-like robot with autonomous generation of jet propulsion. After designing the structure and actuation mechanism by mimicking the scallop, we focus on the effect of the mantle property on swimming. Firstly we confirm that developed robot can perform scallop-like swimming. Secondly we also compare the swimming speed by changing the property of designed mantles.