著者

木下 泰宏

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.810, pp.LH0036, 2014 (Released:2014-02-25)

参考文献数

40

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The purpose of this paper is to clarify the factors which influenced the development of the technology in the Edo period. Especially, this paper tries to consider the influence on the mechanical technology development by the “Shinki-hatto”. “Shinki-hatto” law was promulgated in 1721. It has been proposed in the field of the history of engineering and intellectual property that invention is strictly prohibited by this law and the law causes Japan's stagnant technology development in the Edo period. This paper makes clear that the principal purpose of the law was to maintain the economic and institutional status quo. In addition, the paper suggests the possibility that the law fell short of expectations in terms of effectiveness.

著者

森上 雄太 中山 裕太 高木 健 石井 抱

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.819, pp.DR0322, 2014 (Released:2014-11-25)

参考文献数

15

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This paper describes a monocular stereo system that can switch its viewpoint hundreds of times of more in a second using a four-pinhole viewpoint switching iris mechanism. Our system can measure the three-dimensional information of a moving object correctly using two different viewpoint images, which are selected from the four switched viewpoint images in a short interval using a four-pinhole viewpoint switching iris mechanism, corresponding to the moving direction of the object. Using a prototype of monocular stereo system that consists of the four-pinhole viewpoint switching iris mechanism and an offline high-speed video camera, we verified its effectiveness in monocular stereo measurement by performing several experiments of moving objects.

著者

木村 勇次 井上 忠信 中田 隆之 福田 又一

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.84, no.860, pp.17-00493, 2018 (Released:2018-04-25)

参考文献数

24

被引用文献数

1 7

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Delayed fracture susceptibility of 1.8 GPa-class ultra-high strength bolts was evaluated by an outdoor exposure test. Low-alloy steel bars with a chemical composition of Fe-0.4%C-2%Si-1%Cr-1%Mo (mass%) were quenched and tempered at 500 °C for 1 h, caliber-rolled at 500 °C with a rolling reduction of 78%, in order to create fail-safe steels (FS steels) with an ultrafine elongated grain structure. Subsequently, FS steel bars were formed into JIS M12 hexagon head bolts with a nominal length of 60 mm (FS bolts). Bolt heading was performed at 700~730 °C, and screw part was formed by thread-rolling at 500 °C to maintain the ultrafine grain structure with a strong <110>//rolling direction fiber texture. Conventionally quenched and tempered bolts (QT bolts) with a tempered martensitic structure were prepared for comparison. A steel plate was fastened by the bolts on 23 April 2013, and the outdoor exposure test was started on 21 May 2013 in Miyako Island test site of Japan Weathering Test Center. The bolt fastening force was 122 kN (=0.85 σ0.2 at thread part) for FS bolts and 89 kN (=0.70 σ0.2 at thread part) for QT bolts. The outdoor exposure test demonstrated an excellent delayed fracture resistance of FS bolts at the ultra-high tensile strength of 1.8 GPa; FS bolts have not been broken for 53 months, in contrast to QT bolts exhibiting delayed fracture. Intergranular cracking along the prior-austenite grain boundaries was commonly observed in the broken QT bolts. The accelerated laboratory test using tensile tests of pre-hydrogen-charged specimens and immersion test (30 °C, pH2) showed that the FS bolts had high resistance to hydrogen embrittlement, and it was in good agreement with the result of outdoor exposure test of the FS bolts.

著者

佐藤 悠 井上 健司

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.843, pp.16-00348, 2016 (Released:2016-11-25)

参考文献数

20

被引用文献数

1

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A method for a six-legged robot of walking on terrain with various undulations by tripod gait is proposed. First the robot detects foot landing using touch sensors, and estimates the inclination angle of the ground from the landing positions; the estimated ground is called “reference ground”. Second the robot measures the inclination angle of its body using acceleration sensor. Then the legs move up and down so that the body may be parallel to and may keep a constant distance from the reference ground. If the robot encounters deep depressions or downward slopes, the robot suspends walking and actively inclines the reference ground. As a result the body inclines, and the swing leg goes further down. When the swing leg reaches the ground, the robot restarts walking. Due to the feedback gain of body orientation control, the robot does not respond to fine change of undulation. Hence the body keeps a constant orientation on short distance undulation or rugged surface, and gradually inclines its body on long distance undulation such as slopes and stairs. The ability of climbing up and down slopes and steps in longitudinal and transverse directions is evaluated by experiments. The maximum angle of climbing up slopes is 30 degree, and that of climbing down slopes is 40 degree. The maximum height of climbing up steps is 150 mm, and that of climbing down steps is 180 mm. The robot can also go through a bump of 125 mm width and 60 mm height.

著者

横山 真男 瀬田 陽平 矢川 元基

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.17-00287, (Released:2017-12-06)

参考文献数

15

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Based on experimental observation of liquid dripping, a method to prevent liquid adhesion at the wall of cup was proposed in this paper. When water or sauce etc. is poured from edge of a cup or a pot, the liquid adheres to the wall of cup, which often makes a table or clothes dirty. To clarify the above annoying problem, the flow dripping from the cup, whose edge was shaped to have various thin channels, was observed by using high speed camera. We found the water adhesion on cup's wall reduced when the channels were located at the outside of edge of the cup.

著者

齊藤 亜由子 宮脇 和人 小松 瞭 巖見 武裕

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.865, pp.18-00263, 2018 (Released:2018-09-25)

参考文献数

20

被引用文献数

1

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This paper describes the use of nine-axis motion sensors to evaluate the motion sensor position on the thigh and lower leg during walking. The motion sensors are mounted on a subject's body using adhesive tape. The muscles constantly relax or contract because of human movement. Therefore, joint angle estimation using motion sensors produces different accuracy depending on the position where the motion sensor is mounted. Evaluating the motion sensor position is important for improving the joint angle estimation accuracy. For this study, the authors used six nine-axis motion sensors and a 3D motion analysis system to assess walking exercise. Three motion sensors were mounted to the thigh; three were mounted to the lower leg. The knee joint angle was estimated using a sensor fusion algorithm that corrected the centrifugal acceleration and the tangential acceleration in the acceleration sensor output. We evaluated the accuracy of knee joint angle estimation by comparing the nine-axis motion sensor results and the 3D motion analysis system results. Results demonstrated the possibility of high-accuracy estimation when the motion sensor is attached to a position 50% or 75% from the upper end of the thigh and another sensor is attached to a position 25% or 50% from the upper end of the lower leg.

著者

松永 拓也 越塚 誠一 保坂 知幸 石井 英二

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.19-00186, 2019 (Released:2019-09-25)

参考文献数

37

被引用文献数

1

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In this paper, we proposed a new particle method for numerical simulation of droplet dynamics. In the proposed method, the moving surface mesh is used to define interface between gas and liquid. The volume enclosed by the mesh represents the liquid droplet, and the outer domain is inactive gas with constant pressure. The incompressible liquid flow is calculated using a particle method, in which spatial derivatives are evaluated using an arbitrary high order accurate scheme. On the free surface, the surface stress balance equations, including surface tension and viscous stress, are adopted for the boundary conditions. Deformation of the gas-liquid interface is explicitly calculated by surface nodes that move in a Lagrangian fashion. Surface tension force is directly evaluated with high accuracy on each node utilizing the mesh shape. As numerical verification, simulations of three benchmark problems, namely circular patch test, Laplace pressure test and 2D droplet (liquid column) oscillation problems with different oscillation modes, have been carried out. The computation results were compared with the theoretical solutions, and excellent agreements were obtained. As a result, high accuracy and validity of the proposed computational method were confirmed.

著者

炭竈 美穂 梅原 徳次 野老山 貴行 上坂 裕之

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

vol.80, no.811, pp.SMM0038, 2014 (Released:2014-03-25)

参考文献数

13

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Disc brake is one of the most important auto mobile components and the toughest frictional components. Nowadays, the lightweight disc brake is needed for better fuel-efficient. To reduce the weight, high frictional and low aggressive brake pad is required. However, generally high friction cannot provide low wear of counter-part, therefore to make such brake pad is difficult. In addition, including many kinds of materials such as abrasive, binder, filler and so on, we cannot design it theoretically. In order to overcome these issues we focused on abrasive shape in brake pad, especially focused on open angle of abrasive φ and the important index “degree of wear fab”. If degree of wear fab decreases with open angle φ of abrasive and reduction of wear is more than reduction of friction, we can propose the high frictional and low aggressive brake pad which includes small open angle abrasive. In order to validate our proposals, we conducted the scratch test using Vickers indenter and Knoop indenter. As a result of the scratch test, we clarified that the ratio of wear coefficient to friction coefficient K / μ is correlated with degree of wear fab, and in the region of ploughing and wedge, degree of wear fab decreased with decreasing open angle φ. Due to these phenomena, the ratio of wear coefficient to friction coefficient K / μ decreased with decreasing open angle φ in the region of ploughing and wedge. Thus it was valid that small open angle abrasive provides high friction and low aggressiveness.

著者

天寅 喬文 渕端 学

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.875, pp.18-00399, 2019 (Released:2019-07-25)

参考文献数

8

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In recent years, NOx and soot contained in the exhaust gas of diesel engines become problems. Currently they are elutriated by exhaust gas aftertreatment devices, which make the engine system more complicated. Therefore, we focused on emulsion fuel, which is known as one of the simultaneous reduction technology of NOx and soot. Although emulsion fuels are generally characterized by its water content, some literatures report that the effect on the diesel engine performance could not be controlled by the water content properly. Therefore, we focused on dispersed water droplet diameter as the other factor. In this study, we prepared emulsion fuels of different water droplet diameters and investigated the exhaust gas and power performance of a diesel engine with these fuels. The emulsion fuels consist of light oil, water and surfactant. We added 2.0 vol% of surfactant whose HLB value was adjusted to 6.0 to light oil. The water content was 10 and 15 vol%. We prepared emulsion fuels of three different mean dispersed water droplet diameters. The test fuel was 6 types of emulsion fuel (3 kinds of dispersed water droplet diameter, water content 10 and 15 vol%) and light oil. The diesel engine used in our experiment was of air-cooled, single-cylinder, jerk pump driven direct injection type. The displacement is 320 cc. We measured in-cylinder pressure, ignition delay, exhaust gas emission (NOx, Soot and CO) and power performance (Output power and Thermal efficiency). We found a relationship between the Sauter Mean Diameter of dispersed water droplets (DS.M.D.) and each parameter. The smaller DS.M.D. is, the more the NOx and soot are reduced. On the other hand, the bigger DS.M.D. is, the higher the output and thermal efficiency are.

著者

野口 聖史 小國 健二

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.19-00099, 2019 (Released:2019-06-25)

参考文献数

16

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Differential form is an alternative mathematical form to describe the field variables and the operators in electromagnetism. From the viewpoint of differential forms, discretization of electromagnetic field is divided into two steps, i) discretization of the exterior derivative operator (Maxwell’s equations), and ii) discretization of the Hodge star operator (constitutive equations). The first step, the discrete form of the Maxwell’s equations based on differential forms has been obtained by other researchers. In contrast, the discrete Hodge star operators (discrete constitutive equations) have not been obtained so far. In the previous studies, unsigned diagonal discrete Hodge star operators are defined using the unsigned area and length for circumcenter dual meshes, however, it does not lead to correct solution of partial differential equations in the general Delaunay meshes. In this paper, we propose a definition of the signed diagonal discrete Hodge star using the signed area and length operator for circumcenter dual meshes. Also, based on this definition, we propose a simple practical calculation method for the signed discrete Hodge star operators. The result of convergence experiment indicates that the signed diagonal Hodge star operators produce the correct numerical solution for the general Delaunay meshes. Therefore, this definition and calculation method for the signed discrete Hodge star operator provides us with the explicit dynamics formulation for finite element analysis of electromagnetic field.

著者

根岸 秀世 雨川 洋章 間庭 和聡 小原 新吾 羽山 誠 董 大明

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.875, pp.19-00086, 2019 (Released:2019-07-25)

参考文献数

22

被引用文献数

2

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Grease lubrication in ball bearings is one of key technologies to reduce energy consumption and enhance lifetime in design of spacecrafts as well as general industrial machineries. From a view point of grease lubrication design, it is crucial to understand grease macro flow phenomena in ball bearings taking into account non-Newtonian property of grease. In the current study, grease macro flow phenomena were investigated based on experimental and numerical works as a preliminary study. Grease dam breaking was defined as a benchmark problem and its collapsing phenomena were experimentally observed. As for the numerical work, a basic algorithm to simulate non-Newtonian grease macro flows was developed based on the explicit MPS (Moving Particle Simulation) method coupled with Bingham pseudoplastic fluid model. The observed grease dam breaking behavior was simulated by the developed numerical approach and the numerical results showed a good agreement with the corresponding experimental data.

著者

積際 徹 本元 泰穂 横川 隆一

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.841, pp.16-00010, 2016 (Released:2016-09-25)

参考文献数

23

被引用文献数

2 3

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The objective of this study was to develop a motion analysis system to evaluate relations between the activation of the lower limb muscles, the pedal force and the movement of the lower limb during the pedaling motion. To confirm the effectiveness of the proposed analysis system, we analyzed the pedaling motion of nine cyclists to identify their pedaling skill. In the experiments, cyclists were instructed to perform their pedaling technique at two pedaling rates (80-90 rpm and 110-120 rpm). Surface electromyography (EMG) signals was recorded from tensor of latae (TFL), rectus femoris (RF), hamstrings (HAM) and gastrocnemius (GAS), and pedal force was measured by a power meter (Pioneer Corporation). Furthermore, the lower limb motion during the pedaling was measured using a 3D motion capture system to investigate the relations among measured data as mentioned above. The experimental results show that the proposed analysis system reveals the pedaling skill of cyclists and the relations between the EMG data, the pedal force and the movement during the pedaling motion. In this paper, firstly, the activation section of the lower limb muscles during the pedaling was determined quantitatively. Secondly, Tukey-Kramer test was conducted to determine whether there are significant differences (p < 0.05) between the pedaling effectiveness of the three groups (elite group, amateur group and beginner group). Finally, the pedaling skill of the cyclists was revealed based on the analysis results of the measurement experiments.

著者

鞍谷 文保 北林 研人 小川 渉 吉田 達哉 長村 光造 小出 俊雄 文珠 義之 水田 泰次

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.17-00110, (Released:2017-07-06)

参考文献数

13

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Cymbals are percussion instruments that vibrate and radiate sounds when hit with a stick or when used in pairs. The sound radiated from a cymbal depends on its vibration characteristics. Cymbals are made through spin forming, hammering and lathing processes. The spin forming creates the domed shape of cymbals, determining the basic vibration characteristics. The hammering and lathing make specific sound quality adjustments by changing the vibration characteristics. In this paper, we focus on how the hammering affects the cymbal's vibration characteristics. The hammering produces many shallow dents over the cymbal's surface, generating residual stresses in it. These residual stresses change the vibration characteristics. We perform finite element analysis of the hammered cymbal to obtain its vibration characteristics. In the analysis, we use thermal stress analysis to reproduce the stress distribution and then with this stress distribution we perform vibration analysis. The results show that the effects of thermal load (i.e., hammering) vary depending on the mode: an increase or decrease in the natural frequency. As a result, the peak frequencies and their peak values in the frequency response function change.

著者

Liu Chen 藤本 由紀夫 田中 義和 上杉 征 並河 隆浩

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.816, pp.BMS0244, 2014 (Released:2014-08-25)

参考文献数

7

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When human body is punched by the boxing glove, both of the body surface and the boxing glove deform in a complex shape. The purpose of this study is to develop a flexible sensor that can be used in such interface. Firstly, several mechanical phenomena, which are the cause of error signal of the sensor, are discussed. These are the influences of out-of-plane bending deformation, shear force caused by rubbing force, shear force caused by the Poisson's effect of contact material, and the transverse compressive force caused by the overhanging deformation of flexible material. Then as a sensor that can eliminate the error factors of these, a distribution type impact sensor in which sixteen sensor elements are arranged in a 4x4 matrix is developed. Punching experiments using a boxing glove are carried out by installing the sensor on the load cell, on the concrete wall and on the sandbag. From the experiment, it is found that the impact force can be measured with good accuracy by using the sensor. Despite the sensor has inadequate distribution number of sensor elements, the sensor structure includes mechanical requirements for the flexible impact sensor.

著者

永島 唯哉 池田 生馬 岩附 信行

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.873, pp.18-00439, 2019 (Released:2019-05-25)

参考文献数

13

被引用文献数

1

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When one rides a car on a gravel road, a noise due to collision of gravels rolled up by tires makes him uncomfortable. The collisions are assumed as random impacts with respect to mass, collision time, position, velocity, angle and so on. In order to probabilistically estimate the noise, the time history of impact force in the case where a force sensor on a rigid pendulum hits a peripherally clamped thin rectangular plate is precisely measured for various impact speeds, angles and positions. The vibration response and sound pressure radiating from the plate are then estimated with the measured impact forces based on Rayleigh-Ritz method and impulse response method. It was then revealed that the time history of impact force could be represented with a certain time function for any impact speeds, angles and positions and that the component of the impact force perpendicular to the plate determined the maximum of the impact force. The time history of impact force can also be approximated as a superposition of the extreme function and Gaussian function. The estimated vibration acceleration of the plate and sound pressure agree very well the measured values. The noise generated by random impacts was estimated probabilistically. It was found that the noise strongly depends on the natural vibration modes of the plate.

著者

NGUYEN QUANG Thinh 岩村 幸治 杉村 延広 浦出 俊和 竹歳 一紀 香川 文庸 平原 嘉幸 木下 泰宏

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.18-00220, (Released:2019-02-26)

参考文献数

17

被引用文献数

1

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Much emphasis is now being given to research and development of plant factories which daily produce a large volume of high-quality vegetables under artificially controlled environments. One of the important issues to be considered for the management and the daily operations of the plant factories is to find a set of suitable customers and/or markets to which the daily produced vegetables are sold and delivered. The current wholesale markets of the vegetables are not suitable for trading the high-quality vegetables produced by the plant factories, therefore, a new market is required to sell and to buy the products made by the plant factories. A new trading market system is proposed, to sell and to buy the lettuces supplied by the plant factories, based on the stock exchange mechanisms, in this paper. An estimation method of yield rate is also proposed to generate a suitable volume of sales for the plant factories. Some case studies have been carried out to verify the effectiveness of the proposed trading market.

著者

沖野 友洋 永田 恵輔 佐藤 裕之 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

vol.85, no.869, pp.18-00270, 2019 (Released:2019-01-25)

参考文献数

11

被引用文献数

2 4

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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. However there is no standard for crash safety in Japan. In order to discuss guidelines for the crash safety design of the vehicle structure, it is important to grasp the actual situation of collision accidents in Japan. Therefore, firstly the authors performed the statistical analysis of serious level-crossing accidents for the past 30 years. Secondly, we carried out finite element analyses of a level crossing accident with a dump-truck under various conditions (collision position, collision angle, collision speed and mass of the load on the dump-truck) based on the result of the statistical analysis. We also evaluated their results in terms of the contact force, the deformation energy of the rail vehicle, the deformation amount of the cabin, the mean deceleration of passenger’s area (conformable to European standard), the maximum deceleration of the passenger’s area and the secondary impact velocity of the passenger (American standard). The degree of correlation among these results was discussed. The analyses showed that the horizontal collision position of the dump-truck and the collision speed had a comparatively large effect on the safety of passengers, and further that the mass of the load on the dump-truck also affected it when the secondary impact velocity was used as an evaluation index.

著者

岩部 洋育 菊池 恭平 白井 健司

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.15-00289, (Released:2015-11-12)

参考文献数

6

被引用文献数

1 4

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This paper deals with the geometrical analysis of the surface roughness of a radius end milled workpiece with an inclined surface using the contouring and scanning cutter path methods. In the case of contouring, first it was classified into three types of cutting edges for generation of inclined surface. Secondly, three equations of the theoretical roughness of the machined surface were lead based on the geometrical analysis for each type. The calculation values of surface roughness almost coincide with the experimental values, therefore the validity of the analytical method is cleared. In the case of scanning, first the envelope surface of the bottom and corner edges was defined as the lower half surface of the torus. Secondly, the calculation and estimating method of the envelope curve which was obtained by the outside line of the projected torus surface is shown. The estimated values of surface roughness almost coincide with the experimental values, therefore the validity of the analytical and estimating method are cleared too. Finally, the selection of the scanning method is more effective in order to achieve highly accurate machining.

著者

黒島 亮 大高 武士 門 久義

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.819, pp.FE0318, 2014 (Released:2014-11-25)

参考文献数

21

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Recently, the micro-bubble technologies are applied in a wide field, and grow to the field close to the human lives. Though many methods of micro-bubble generation have been proposed, pressure loss of a venturi tube is less than among others. The studies on micro-bubble generation with venturi tube have ever seen, but the generation mechanism of a micro-bubble is not fully evident. The purpose of this paper is to make the micro-bubble generation mechanism experimentally clear. In conclusion, by inspecting the images of high-speed camera, the water jet occurs on the trailing edge of a bubble when its leading edge arrives at the throat inlet and divides it into two parts in the throat section. Then, passing through the diffuser, outer shapes of the two parts become unstable and break down into micro-bubbles. It is clear that the mechanical conditions of this occurrence are based on the accelerations at a nozzle and a diffuser. Then, the generated bubble size is distributed around a peak of about 200µm.

著者

横山 綾亮 小村 啓 坪井 諭之 大岡 昌博

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

pp.18-00283, (Released:2018-10-30)

参考文献数

13

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Hardness representation in VR is one of the important problems to create virtual touch feeling as if the feeling is caused by real touch. In this study, we are attempting to improve the hardness representation method by combining the pseudo-haptics and tactile stimuli, which was presented in our previous research. In the current study, we investigated the ability of both of these methods to express tactile hardness stimulation: in Experiment A hardness was generated solely by visual stimulation using CG; and in Experiment B hardness was generated solely by the dot-matrix display. Based on the results of Experiments A and B, in Experiment C we conducted psychophysical experiments on the ability to express tactile hardness by combining the effects of pseudo-haptics and the tactile stimuli. In Experiment C, we were able to express six levels of distinguishable hardness, while only four and two levels were observed in Experiments A and B, respectively. In addition, the relationship between hardness evaluation and the six levels shows high linearity with R2 = 0.98.