著者

山崎 容次郎 横川 隆一 積際 徹 原 敬

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.740, pp.867-875, 2008-04-25 (Released:2011-03-04)

参考文献数

17

被引用文献数

2 4

---

This paper proposes a new switching method of control mode for a robot manipulator coming in contact with environment that has elasticity. First, the basic concept of the switching of the control mode in a robot manipulator is explained. Second, we propose a new method of switching the control mode that selects the control mode at the intersection of “Characteristic curve of position and force” and “Target value of the work composed by the desired value of position and force”. Next, the switching algorithm based on this method is obtained about a certain work coordinate with a Multi-DOF robot manipulator. In this paper, the switching method is named “A Method for Switching Control Mode Based on Position and Force Errors”. Furthermore, when a One-DOF robot manipulator driven by DC servo motor with reduction gears using an elastic joint came in contact with the object that has elasticity, the simulation and the experiment on various angle and torque controls were done. As a result, it is shown that the proposed switching method is useful and has stable and flexible characteristics.

著者

大西 厳 木村 一郎 山田 英巳

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.65, no.635, pp.2787-2793, 1999-07-25 (Released:2008-02-26)

参考文献数

13

被引用文献数

2 3

---

Recently, we have been demanding products that satisfy personal tastes. In these days, it is extremely important to make a human sensibility model and then build up a technology system for applying human sensibility to various fields in engineering. In this paper, a human sensibility model for musical chords is studied. The model that uses an artificial neural network is constructed by ccnsidering the structure of a cochlea that analyzes sounds into frequency. The musical chords that are composed of three or more musical tones are inputted into the neural network, and a set of the sensibility information that characterizes "cheerfulness-gloominess", "thickness-thinness" and "stability instability" is outputted. After training the model, the following results that agree with the knowledge of psychology and physiology are proved. 1) Some hidden units for "cheerfulness- gloominess" and "stability instability" are influenced by the critical bandwidth of musical tone frequency, and furthermore they have "Tonality". 2) For "thickness thinness", there is a unit that distinguishes musical tones by frequency.

著者

柴田 信一 曹 勇 福本 功

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.71, no.707, pp.2414-2419, 2005-07-25 (Released:2011-08-16)

参考文献数

9

被引用文献数

2 1

---

Bending modulus of elasticity of the composite material from bagasse fiber (remains after sugar cane squeezed) and biodegradable resin was investigated in view of the content of bagasse fiber and the fiber length. The result was validated by short fiber strengthen theory. The result is as followings. Bending modulus of elasticity increased with increasing the content of bagasse fiber. The increase of Bending modulus of elasticity is predicted by short-fiber strengthen theory incorporated with the compression ratio of bagasse fiber, which has honeycomb structure in the cross section, was compressed in press forming, makes good agreement with the experimental result. Bending modulus of elasticity decreased when the fiber length of bagasse is under 3 mm (aspect ratio=12). This result makes good accordance with the prediction value by the short fiber strengthen theory.

著者

野島 武敏

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 C編 (ISSN:03875024)

巻号頁・発行日

vol.66, no.647, pp.2463-2469, 2000-07-25 (Released:2008-02-26)

参考文献数

8

被引用文献数

4 5

---

The aim of this paper is to invent foldable (or developable) conical shells in their axial direction. Foldable conical shells with several different types of folding patterns have newly been designed by geometrical considerations with the help of Origami concept. By using thin polypropylane sheet as well as papers, the designed conical shells with prescribed folding lines were actually manufactured, and it was verified that the shells are fully folded as expected. The designed models will make it possible to construct foldable/developable structures such as tents and dome-roof or to manufacture new types of industrial products.

著者

田中 裕久 大石 保徳

出版者

The Japan Society of Mechanical Engineers

雑誌

日本機械学会論文集 C編 (ISSN:03875024)

巻号頁・発行日

vol.65, no.637, pp.3804-3810, 1999

被引用文献数

1

---

A double cavity half toroidal contimlously variable power transmission transmits input torque through a pair of variable units and changes its speed ratio by controlling attitude angels of four power rollers. One power roller among them is controlled by a hydraulic servomechanism and the others are followed it under the control principle of equal force transmission. Synchronization of four power rollers is guaranteed by safety wires, however nonlinearities of friction force on the control pistons or pressure delay in hydraulic lines due to air mix or pipe length cause instability of the speed ratio servomechanism through the safety wires. This paper focuses the relation between the synchronization and stability of the CVT by making bond graph analyses and experiments, and shows design guidelines on the stabilization of the double cavity half toroidal CVT.

著者

谷 泰弘 金 泰元 澤山 翔 蔦中 孝丞 山口 幸男 佐藤 康治

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.76, no.762, pp.453-458, 2010

参考文献数

5

---

In order to reduce the costs in wheel manufacturing and on usage of the wheels, we investigated the method of adjusting the sharpness of grinding wheels by using heat treatment and UV treatment. At first it was confirmed that heat treatment of phenol resin grinding wheels for aluminum in a furnace enabled to improve the grindability of stainless steel and to prevent swarf loading. Next it was made clear that surface treatment of grinding wheels by using UV irradiation and hot air blowing had the similar effect with the heat treatment in a furnace. These treatments reduced the force ratio in surface grinding. In these cases the affected layer was limited to the wheel surface though heat treatment in a furnace affected the whole wheel. The thickness of the layer varied with the UV irradiation time. At last we applied this technique to other resinbond wheels and the same effect was obtained for the wheels with polyester bond. However heat treatment did not improve the grindability of epoxy bond wheels with high heat resistance. In such case UV treatment was an effective method to activate flow-out of swarf.

著者

野中 俊昭 大山 忠夫 遠藤 靖典 吉川 広

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.71, no.705, pp.1604-1610, 2005-05-25 (Released:2011-03-04)

参考文献数

14

被引用文献数

1

---

Dynamic behavior of train sets on railways during braking can be regarded as the combination of the translation and the rotation. That is, both the kinetic energy for the translation of train sets and the one for the rotation of each axle are decreased to zero as the braking force and the adhesion force of each axle have an effect on each other. However, dynamic models for brakes of train sets have been hardly represented and discussed. Furthermore, a reduction of wheel damages has never been evaluated for control performances of Anti-lock Braking System (ABS), in spite of one of the most important aims of ABS. In this paper, we propose a dynamic model for brakes of train sets consisting of n axles and an equation for evaluating wheel damages. And we show that the proposed model and equations are useful to evaluate the control performances of ABS for train sets.

著者

吉澤 正彦 景山 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.71, no.702, pp.541-546, 2005-02-25 (Released:2011-03-04)

参考文献数

4

---

This paper focuses on the tire force characteristics related to the vehicle speed. We constructed a mechanical tire model using a Voigt-Type viscoelastic spring system for the tread rubber. And, we analyze the force distribution along the contact length, the dependence of vehicle speed to the tire forces and the moments to a change in sideslip angle. Finally, it is shown that the tire model has good agreement with actual measurements results qualitatively, and also it is found that the characteristics of lateral force have independence to the vehicle speed.

著者

和田 憲造 藤本 康之 早野 延男 埴谷 和宏

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 C編 (ISSN:03875024)

巻号頁・発行日

vol.56, no.524, pp.935-940, 1990-04-25 (Released:2008-02-21)

参考文献数

4

被引用文献数

3

---

The screw feeder is extensively used as a feeder of granular materials. Until now, a few reports regarding the fundamental characteristics of the screw feeder, for example, the required power and the quantity of discharge from the feeder, have been published. However there are almost no reports on the dynamic characteristics and the transportation mechanism. In this paper, the transporting state and the transportation mechanism of granular materials inside the screw feeder are investigated. First, the effects of the rotating speed of the screw shaft and the pressure of granular materials inside a feed hopper on the required power and quantity of discharge are examined. Secondly, the transporting state of granular materials inside the screw feeder is investigated. Then the transportation mechanism is discussed by analyzing the motion of a tracer inserted into the screw feeder and by using a velocity diagram.

著者

谷本 隆一 朝倉 孝征 今井 守之 鶴見 康昭 安田 仁彦

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.69, no.686, pp.2550-2555, 2003

---

In recent years one-box-cars are very popular in the market. So their interior noise level is required to be the same as that of passenger cars. To find an effective way to reduce the noise level, we studied why the noise level is high in a one-box-car as compared with a passenger car. We found that, because the diesel engine is placed under the front passenger seat, only narrow space is allowed between the engine and the engine cover, and this narrow space amplifies the noise. We confirmed by numerical simulation that this conclusion is appropriate. Based on the conclusion, we proposed to set up a silencer to lower the noise level, and found that it works effectively.

著者

灘野 宏正 中迫 正一 河野 正来 南 一郎 山口 博幸

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 C編 (ISSN:03875024)

巻号頁・発行日

vol.70, no.690, pp.554-559, 2004-02-25 (Released:2011-03-04)

参考文献数

7

---

To clarify the wear resistance and seizure resistance of the vegetable oils with anti-wear additives of Dibenzyl-Disulfide (DBDS) and Phosphonic Acid-Dibutyl (DBPo), the four-ball tests were carried out under dip-feed lubrication using Soda-type four-ball machine. The width of the wear scar on the stationary balls lubricated with the vegetable oils containing DBPo additive was smaller than that without the additive, and was smaller than that containing DBDS additive. The seizure resistance of the vegetable oils with DBDS additive increased in following order : Turbine oil<Rapeseed oil<Soybean oil<Corn oil. On the other hand, the seizure resistance of the vegetable oils with DBPo additive increased in the following order : Turbine oil<Soybean oil<Corn oil<Rapeseed oil. The DBPo additive showed significant improvements in seizure resistance compared with DBDS additive.

著者

灘野 宏正 中迫 正一 河野 正来 南 一郎 山口 博幸

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 C編 (ISSN:03875024)

巻号頁・発行日

vol.70, no.690, pp.554-559, 2004

---

To clarify the wear resistance and seizure resistance of the vegetable oils with anti-wear additives of Dibenzyl-Disulfide (DBDS) and Phosphonic Acid-Dibutyl (DBPo), the four-ball tests were carried out under dip-feed lubrication using Soda-type four-ball machine. The width of the wear scar on the stationary balls lubricated with the vegetable oils containing DBPo additive was smaller than that without the additive, and was smaller than that containing DBDS additive. The seizure resistance of the vegetable oils with DBDS additive increased in following order : Turbine oil<Rapeseed oil<Soybean oil<Corn oil. On the other hand, the seizure resistance of the vegetable oils with DBPo additive increased in the following order : Turbine oil<Soybean oil<Corn oil<Rapeseed oil. The DBPo additive showed significant improvements in seizure resistance compared with DBDS additive.

著者

御手洗 毅 山浦 弘 小野 京右

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.72, no.723, pp.3576-3583, 2006-11-25 (Released:2011-03-04)

参考文献数

5

被引用文献数

1

---

Rhönrad is a gymnastic equipment that is interesting in terms of dynamics and control. We presented an analytical model and governing basic equations of the Rhönrad mechanism with a human body model. Then, a control method named as Synchronous control was proposed. In this control method, the human body moves synchronously with the rotation angle of the Rhönrad. The motion caused by Synchronous control was numerically analyzed. After that, a standalone miniature Rhonrad robot that consisted of three gyro sensors, an actuator, a micro-computer and batteries was manufactured. The validities of the Synchronous control were shown by experiments with the robot.

著者

古林 卓嗣

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.66, no.641, pp.306-313, 2000-01-25 (Released:2008-02-26)

参考文献数

12

被引用文献数

1 1

---

A numerical study of self-acting gas-lubricated wave journal bearings is presented for their dynamic performances : HFW(self-excited half-frequency whirl)stability and dynamic response of an out-of-balance rotor. The study is conducted under practical operating conditions by means of a nonlinear orbit approach. Numerical examples of wave bearings are compared with those of herringbone-grooved bearings, and it is found that wave bearings give relatively favorable dynamic performances. Considering both HFW stability and dynamic stiffness, three-wave bearings are recommended for a practical use. However, it should be pointed out that HFW stability of wave bearings is quite sensitive to the wave amplitude, and also the synchronous orbit geometry of an unbalanced rotor supported on a wave bearing can be complicated out of plain circle.

著者

古林 卓嗣

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.62, no.604, pp.4636-4643, 1996-12-25 (Released:2008-02-26)

参考文献数

20

被引用文献数

1 1

---

A multigrid method has been introduced as a fast alternative to conventional relaxation methods for obtaining a solution to the Reynolds equation for self-acting gas-lubricated bearings. This paper verifies the procedure applied to both static and time-dependent dynamic analyses of plain-cylindrical journal bearings. The method gives successful results with less computational effort compared with single grid-oriented iterative methods. In addition, the new approach does not require a trial and error process to optimize the overrelaxation parameter unlike a successive overrelaxation method. The nonlinear orbit method which is an accurate but time-consuming transient analysis is expected to be reduced to a handy design tool for a complicated bearing system on incorporating the multigrid technique.

著者

古林 卓嗣

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.65, no.629, pp.330-336, 1999-01-25 (Released:2008-02-26)

参考文献数

12

被引用文献数

1 1

---

Both experimental and numerical studies are conducted on half-frequency whirl (HFW) stability of axially-grooved self-acting gas-lubricated journal bearings. The studies demonstrate that 8-grooved bearings are unconditionally unstable with usual bearing clearance and rotational speed. On the other hand, 2 grooved bearings operate stably at relatively low values of bearing number which are obtained with usual clearance and speed. The physics of HFW stability is attributed to the pressure distribution geometry. Further, as a result of extensive numerical simulations, it is found that 3 grooved bearings with groove width ratio to total width of 0.3 through 0.5 give favorable stability performance.

著者

川副 嘉彦 武田 幸宏 中川 慎理

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.76, no.770, pp.2646-2655, 2010-10-25 (Released:2017-06-09)

参考文献数

18

被引用文献数

1 1

---

There has been no question that some strings do provide a better grip than others, but that did not guarantee that the ball will produce more spin. Furthermore, experiments with hand-held rackets has been needed to solve the vexed question of how players can tell the difference between different strings when laboratory tests indicate that they should play the same. The previous paper of the authors made clear the mechanism of top spin performance in actual tennis and its improvement by lubrication of notched nylon strings according to the high speed video analysis on the court for the first time. It succeeded in an experiment showing that as the main strings stretch and slide side ways more, the ball is given more spin due to restoring force parallel to the string face when the main strings spring back and the ball is released from the strings. Since the notches of strings decrease spin rate, the lubricant materials are effective to the notched strings. Furthermore, it showed that the more spin results in the reduction of shock vibrations of the wrist joint during impact. This paper showed that the ball is given less spin rate (40% decrease) with the notched used strings compared to that with the new strings in the case of the nylon in this experiment, which has remained to be seen which gives more spin between new strings and the lubricated used strings, and it showed that the ball is given more extra spin (30% increase) by oil lubrication at the string intersections compared to that with the notched used nylon strings. Furthermore, it also showed that the used natural gut with notches decrease 70% of spin rate compared to the new natural gut without notches in the another experiment, which has remained to be seen whether the same results will be obtained. It also showed the difference of the topspin behavior when a pro and an amateur hits a ball.

著者

川副 嘉彦

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.58, no.552, pp.2467-2474, 1992-08-25 (Released:2008-02-26)

参考文献数

3

被引用文献数

2 4

---

There are a number of unclarified points regarding the impact phenomena and the optimum design of tennis rackets. The present study is based on the idea that the dynamics of a racket consists of the dynamics of a rigid body with an arm swing given at a grip as a boundary condition, an impact between a ball and strings with racket frame as an input force, and the structural vibration of the racket. In this paper, impact force and impact duration are investigated, considering the strong nonlinearity of the restoring force of ball and strings. Furthermore, the coefficient of restitution of the tennis racket is estimated using a personal computer on the basis of the impact phenomena and the experimental modal analysis. In order to predict the contact duration, which has an influence on the racket vibration, a simple impact model has been proposed, i.e., that the contact duration is determined by the natural period of a whole system composed of the mass of the ball, the stiffness of the ball and strings, and the reduced mass of the racket at the impact point on the racket face. The calculated results agree fairly well with the experimental results.

著者

川副 嘉彦 沖本 賢次 沖本 啓子

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.72, no.718, pp.1900-1907, 2006-06-25 (Released:2011-08-16)

参考文献数

15

被引用文献数

1 2

---

Players often say that some strings provide a better grip and more spin than others, but ball spin did not depend on string type, gauge or tension in the past laboratory experiment. There was no research work on the spin to uncover what is really happening during actual tennis impact owing to difficult experiment. This paper made clear the mechanism of top spin and its improvement by lubrication of strings according to the high speed video analysis. It also provided the more detailed explanations of spin behavior by comparison between a lubricant string racket and a famous 'Spaghetti strings racket' which was banned in 1978 by the International Tennis Federation since it used plastic spaghetti tubing over the strings to reduce friction resulting in the excessive spin on the ball. As the main strings stretch and slide side ways more, the ball is given more spin due to restoring force parallel to the string face when the main strings spring back and the ball is released from the strings. Furthermore, it showed that the more spin results in the reduction of shock vibrations of the wrist joint during impact.

著者

中山 信行 川本 広行

出版者

The Japan Society of Mechanical Engineers

雑誌

日本機械学会論文集 C編 (ISSN:03875024)

巻号頁・発行日

vol.70, no.691, pp.804-811, 2004

被引用文献数

9

---

Formation of magnetic bead chains in a magnetic field was numerically simulated with the Distinct Element Method in order to apply for improvements of a magnetic brush development system in electrophotography. Simulated chain configurations, length and slant angle. and dynamic chain forming process were compared to the experimental results. The 2-D calculation could not simulate quantitatively well the chain configurations and the process, because the magnetic interaction between beads was under estimated due to the neglect of the interaction force between three-dimensionally distributed beads. On the other hand, 3-D calculation showed good agreement with experiments and it is concluded that 3-D calculation is indispensable for the quantitative evaluation. It was also confirmed that chain configurations were determined approximately to minimize its total potential energy given by the sum of magnetic energy and gravitational energy.