著者
臺丸谷 政志 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A編 (ISSN:18848338)
巻号頁・発行日
vol.77, no.776, pp.638-646, 2011 (Released:2011-04-25)
参考文献数
18
被引用文献数
1 1

The Japanese sword is a weapon peculiar to Japan. The Japanese sword is interesting not only from the viewpoint of traditional crafts of arts, but also from the aspect of modern science and technology because the way of making and its functionality as a weapon are really consistent with science. The present study is concerned with the connection between tohshin (blade) and tsuka (hilt) of the sword. Only one mekugi-take (retaining peg made of bamboo) with about 5mm in diameter holds Nakago (tang) in the hilt. However the slender mekugi might not be broken, even though in the case of violent sword-fighting. This fact has been historically demonstrated in many battles by Japanese swords. In this study, using a Tachi being the typical Japanese sword, it is examined theoretically and experimentally from the viewpoint of impact engineering why a mekugi used in Japanese swords might not be broken. As a result, it is made clear that such a strong force as breaking mekugi-take does not act on it, because of the location of mekugi-ana (a hole for mekugi) in the tang, which has been made by the traditional code of sword-smiths.
著者
八木田 幹 鹿野 一郎 清野 将人
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 B編 (ISSN:03875016)
巻号頁・発行日
vol.70, no.691, pp.594-601, 2004-03-25 (Released:2011-03-03)
参考文献数
17

This paper presents experimental and numerical results on the unstable flow along the surface of a circular cylinder in the Coanda effect. The unstable phenomenon depends on the nominal Reynolds number Re*=Uj√ (1/4) hD/ν and the nozzle height of the jet, h. In this paper, the changing phenomenon of two-dimensional jet direction is found numerically and the results are compared with the experimental ones. The numerical calculation is carried out by using the finite-difference method for the conditions of unstable phenomenon, that is, 1.5×104≤Re*≤2.5×104 and 0.100≤h/D≤0.200. Numerical results agree well with experimental results qualitatively. Also, it is found that the unstable phenomenon is sensitive to both Re* and h/D in the vicinity of h/D=0.10. Furthermore, a hysteresis phenomenon of jet direction by Re* was observed.
著者
丸茂 喜高 清水 勇介 竹内 亮佑 綱島 均 小島 崇
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.817, pp.TL0280-TL0280, 2014 (Released:2014-09-25)
参考文献数
9

This study proposes a driving assistance system to inform the notch operation timing for train drivers. The assistance system indicates visually the notch-off position where the driver releases the accelerator. The notch-off position is calculated by the present vehicle acceleration, velocity and position by assuming the constant acceleration. The assistance system also indicates the brake onset and the predicted stopping positions. Two experiments are conducted by using the train-driving simulator. One experiment examines the effects of the notch-off and brake onset timing on the vehicle velocity and the running time. The assistance system makes it possible to adjust the vehicle velocity and the running time. The other experiment examines the three running patterns by combination of the notch-off and the brake onset positions. With the time recovering pattern, which is combination of the higher notch-off velocity and the later brake onset timing, the assistance system realizes the shorter running time in comparison with the standard running pattern. With the energy saving pattern, which is combination of the lower notch-off velocity and the later brake onset timing, the assistance system prevents the time delay by the later brake timing even if the velocity is lower than the standard running pattern.
著者
土屋 晃佑 妻木 勇一 森 恭一
出版者
一般社団法人 日本機械学会
雑誌
ロボティクス・メカトロニクス講演会講演概要集
巻号頁・発行日
vol.2017, pp.2A2-P03, 2017

<p>Bio-logging method obtains information by a data logger attached to the body of animals for ecological survey. It has great potential to reveal various mysteries of animals. Some researchers of sperm whales try to get the video data of preying sperm whales through the bio-logging, but no one has succeeded it. They can conventionally put a data logger only on the back of sperm whale. It is difficult to get video data around the sperm whale's mouth because of darkness of deep sea. To tackle this problem, we have introduced a "Whale Rover" which is able to move along the surface of sperm whale, and provide mobility for the data logger. Until now, we developed several prototypes of whale rover. In this paper, we introduce a new prototype which is expected to adopt curved surface.</p>
著者
小玉 秀男
出版者
一般社団法人 日本機械学会
雑誌
マイクロ・ナノ工学シンポジウム 2013.5 (ISSN:24329495)
巻号頁・発行日
pp.v-viii, 2013-11-04 (Released:2017-06-19)

The concept of rapid prototyping was created based on a technique of making a block copy for printing newspapers. It took a long time till the usefulness of the concept was accepted. A wide variety of practicing the concept was created. The patent application for the concept was abandoned due to law evaluation of the concept. Several modifications adopting the same concept were patented by others due to failure to disclose the modifications.
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
vol.85, no.880, pp.19-00151, 2019 (Released:2019-12-25)
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.
著者
小林 吉之 嶺 也守寛 藤本 浩志
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 C編 (ISSN:03875024)
巻号頁・発行日
vol.73, no.725, pp.274-279, 2007-01-25 (Released:2011-03-04)
参考文献数
14
被引用文献数
1 1

To determine the accuracy of foot position sense in the means of foot placement, young adults were asked to place either medial edge or lateral edge of their feet along the base line on the floor as close as possible, and the edge of placed feet were scanned by using laser displacement gauge. From the collected data, constant error, the distances between the edge of placed feet and the base line on the floor, and absolute error, the absolute distances between the edge of placed feet and the base line on the floor were defined and compared between the medial or lateral trials, and dominant leg or indominant leg. The statistical analysis showed significant differences of constant error between the trials only. The trials to place their medial edge tend to place their feet away from the base line, and the trials to place their lateral edge tend to place their feet in to the base line. These results indicate that we tend to expect the position of our feet more medially than actual, and these discrepancy may be one of a reasons of tripping or banging of our feet to the obstacles while walking.
著者
永瀬 和彦 中村 英男 小林 秀之
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 C編 (ISSN:03875024)
巻号頁・発行日
vol.56, no.523, pp.797-802, 1990-03-25 (Released:2008-02-21)
参考文献数
4
被引用文献数
1

The authors constructed "slipping adhesion test bogie" designed upon a new idea of measuring the coefficient of adhesion continually while running, and have observed the state of adhesion on main lines since 1985. Recently, they placed a car equipped with this bogie on a steep line where wheel-spin and skidding of rolling stock had been frequently the cause of troubles. As the result of runs of the car under various weather conditions such as fine, fog, snow, sleet and frost, influence of the weather condition upon the adhesion between rails and wheels has been made clear and evaluated quantitatively.
著者
横堀 章一
出版者
一般社団法人 日本機械学会
雑誌
日本機械学會論文集 (ISSN:00290270)
巻号頁・発行日
vol.10, no.38-4, pp.38-46, 1944-02-25 (Released:2008-03-28)

戦時下鉄道輸送の重要性は益々増大してゐる。この要求に應ずるために車輌の大増産を必要とする。本論文に於ではこの車輌中特に大量を要する貨車を限定された資材及び労力内でなるべく多量旦迅速に製造するために如何なる努力を排ってゐるかに就て設計を主にして述べる。貨車の戦時設計には在耒ある車輌に増積みする方法と全然新しい形式を設計する方法とがある。鉄道省では両者を並行に採用してみる。後者の例として3袖無蓋車を挙げ、その設計上の要点を述べる。貨車自重1t當りに積載し得る石族最は在耒車が1・16~1・89tであるが、新製3軸車では2・73tとなる。荷重1t當りの製作資材では在耒車の約年分に滅する。而して中梁に生ずる應力を見ても両者の差は著しくない。かかる結果を如何にして得たかに就て説明する。
著者
近藤 千尋 佐野 広季 一宮 暢希 山根 浩二 河﨑 澄
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.874, pp.18-00340, 2019 (Released:2019-06-25)
参考文献数
9

This paper describes how to produce a biodiesel fuel (BDF) from the waste soup of ramen noodles, especially focusing on the recovery process of the oil (triglycerides) from a large amount of waste soup or the oily wastewater disposed of by pouring it down the sink by a ramen restaurant. By combining a semi-transparent bucket (~6 L) with a cock and solvent extraction, it is shown that oil can be recovered easily from 300 or more bowls of ramen noodle waste soup, with an energy profit ratio (EPR) of more than 5.2. The initial cost of the bucket is about 1600 yen, so it has little effect on the price of the BDF produced from the oil in the ramen noodle waste soup, and it is shown that the increase in running cost to produce BDF by this method is about 2.3 yen/L if the rate of recovery of hexane (solvent) is over 99%, which is approximately equivalent to the production cost of waste-cooking-oil BDF production by previously reported methods. Furthermore, in the case of applying the proposed method based on the solvent extraction to the recovery of oil from the oily wastewater disposed of by a ramen noodle restaurant, it is shown that oil can be recovered from the waste soup of ramen noodles just after disposal as well as from the oily wastewater that spent one day in the grease trap. In the former case, EPR is 5.0, and the estimated amount of BDF is greater than 100 L/month for one restaurant. However, in the case of using the oily wastewater from the grease trap, EPR is less than 2.0 because of the reduction of yield of BDF due to a greater oxidation deterioration of the recovered oil, when the alkyl catalyst method is used. Therefore, it is desirable to recover oil from the oily wastewater at the drain pipe just after the sink.
著者
石崎 啓太 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
vol.84, no.866, pp.18-00050, 2018 (Released:2018-10-25)
参考文献数
55
被引用文献数
2 1

This study systematically analyzed life cycle CO2 (LCCO2) emissions of a comprehensive set of mass-produced 2,000 cc class sedan-type vehicles, using a hybrid life cycle inventory approach. Gasoline and diesel internal combustion engine vehicles (ICEVs), hybrid electric vehicle (HEV) as well as battery electric vehicle (BEV) and fuel cell vehicle (FCV) were investigated, considering (i) the current BEV market trends, (ii) Japan's energy mix (the average for 2012–2014), and (iii) the use of the HVAC system. The results show that the annual average increment of CO2 emissions in use phase by HVAC system in Japan (assumed annual mean temperature of 15°C) was presumed to be evenly 9% regardless of vehicle types, although further detail analysis is required. The CO2 emissions in use phase of BEV were higher than those of HEV and FCV (applied hydrogen produced by steam reforming of LPG (on-site)) due to thermal power dominant electricity generation mix in Japan in recent years. As a consequence of high CO2 emissions from power supply and battery production, the LCCO2 emissions of BEV equipped with 75 kWh battery were higher than those of HEV, FCV (on-site), and conventional ICEV (diesel). By reducing the battery capacity to 40 kWh or less, the LCCO2 emissions of BEV become lower than those of ICEVs and FCV (on-site), making BEV a competitive alternative. However, it is difficult that BEV mitigates both LCCO2 emissions and driver's range anxiety. In conclusion, HEV shows the competitive performance in terms of LCCO2 emissions with long driving range in Japan.
著者
堤 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 C編 (ISSN:03875024)
巻号頁・発行日
vol.74, no.746, pp.2387-2395, 2008-10-25 (Released:2011-03-04)
参考文献数
17

Wooden carriage manufacture of Japanese Imperial Government Railway (J. I. G. R.) Works and Japanese young railway engineer cultivation in the Meiji period are described. In the start of J. I. G. R.'s transport business, 143 rolling stocks were imported from the U. K., and English railway engineers were employed. They cultivated Japanese young trainees through the construction of wooden carriages by themselves on the job training. A drawing of Adams bogie track with Munsell wheels, brief personal record of four English railway engineers and three Japanese young engineers were explained. Mechanical Engineering Heritage of four wooden carriages preserved in Japan are introduced, too.
著者
三浦 智 鈴木 智裕 小林 洋 藤江 正克
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.850, pp.16-00414, 2017 (Released:2017-06-25)
参考文献数
30
被引用文献数
1 2

Hemiplegic patients often have reduced typing speed due to finger paralysis. Our motivation is to develop a keyboard that enables their typing speed to increase. For this purpose, we have developed a three-dimensional keyboard that reduces the distance that fingers move while typing. In this paper, our objective was to construct the finger model that combines the motion speed and muscle fatigue for design of keyboard that can be typed with fast motion speed and low muscle fatigue. In experiment, we measured the finger position using a magnetic 3D motion device and EMG when the participant pressed the proposed key. The experiment was carried out in a variety of the finger postures. We qualified the motion speed and muscle fatigue at each joint angle. Then, we weighted and combined two of the objective functions. We found out the Pareto solution and get an effective keyboard design straight. In the future, we verify the typing speed and finger muscle fatigue during typing the three-dimensional keyboard that is designed based on our finger model.