研究一覧（2002年1月〜12月）

超精密切削加工における油剤効果に関する研究
　　奥田孝一，高木光浩，長谷川素由，布引雅之
　　日本機械学会講演論文集，No.024-1，関西支部第77期定時総会講演会，Vol.3 pp11-12.(2002)

　This paper describes an effect and the action mechanism of the cutting fluids on cutting force and surface integrity in the ultra-precision diamond cutting of aluminum. Kerosene and oleic acid are applied to the workpiece and the tool by three methods with the mist and the drops of fluids and the coating on pre-cut work surface. Oleic acid is used to examine the coating effects of organic polarity substances known as Rebinder effect. In the condition of applying the cutting fluids, the cutting force was reduced and the surface roughness was improved comparing with those in dry cutting. The degrees of the effects were almost same in any supply methods of cutting fluids. The supply method by coating on the pre-cut surface is effective in the diamond cutting from the economical and environmental points of view.

インチワームロボットによる回転移動動作に関する研究
　　布引雅之，奥田孝一，長谷川素由，前田俊祐
　　2002年度精密工学会春季大会学術講演会講演論文集，p.196 (2002)

　インチワームロボットは４つのピッチ関節と１つのヨー関節で連結された６つの体節を持つ多関節構造の尺取り虫型移動ロボットである．既に，階段の連続昇降や大きな段差の乗り越えなど多彩な運動能力を持つことを実機にて確認している．またワームのように前進変形波を用いた移動動作については，実機にてその運動性能を検証してきた．しかし，それらの動作での移動速度は１００(mm/s)程度であり．また地面の状態（静摩擦係数や動摩擦係数）に大きく左右されるものであることも判った．そこで本研究では，インチワームロボットの新しい移動方法として，先端と尾端を連結し，ロボット自身がキャタピラのように振る舞う前転移動運動を開発した．そして，解析的および実験的にその運動性能を明らかにした．

Analysis of wake-up motion for an articulated mobile robot
　　M. Nunobiki, K. Okuda, and M. Hasegawa (Tajima Technical Institute)
　　Advanced Robotics, Vol.16 No.6 pp.521-524(2002)

　In this study, an inchworm-type mobile robot has been developed for the purpose of searching for life in the disaster-stricken area immediately after an earthquake. This inchworm robot has an articulated structure. Although the robot has neither legs nor wheels, it is able to creep and crawl to move. The robot has demonstrated high mobility in a sagittal plane. For example, the robot was able to ascend and descend stairs continuously, get over the obstacles 600mm in height, and climb vertical narrow passage. When the robot becomes upside down, it is able to move just like in the normal posture, even if not returning to normal posture. However, when the robot falls sideways, it is not able to move forwards and backwards. Therefore, it has to return to its normal posture quickly. In this study, we proposed the wake-up motion from the rollover state using a yaw joint and analyzed the wake -up motion of this articulated mobile robot.

超精密切削加工におけるバリの生成
　　奥田孝一，谷有希子（三菱電機コントロールソフトウェア），布引雅之
　　精密工学会2002年度関西地方定期学術講演会講演論文集，pp.51-52 (2002)

　本研究では，単結晶ダイヤモンドバイトを用いて純アルミニウムと真鍮の超精密切削加工実験を行い，工具の食い込み時と離脱時のバリの生成状態の観察，測定を行い，加工条件との関連性について検討，考察を行う．アルミニウムの切削では，微小切込み条件になるほど大きなバリが生成し，真鍮では延性的なバリ生成挙動が見られた．また，被削材のエッジ角度を120°程度にすることによりバリの抑制効果が見られた．

Analysis of Wake-up Motion for Articulated Mobile Robot
　　M. Nunobiki, K. Okuda, and M. Hasegawa (Tajima Technical Institute)
　　Proceedings of the First Asian Conference on Multibody Dynamics 2002, pp.365-371 (2002)

　In this study, an inchworm-type mobile robot has been developed. This robot has an articulated structure. This robot is able to advance by using vertically undulatory motion of whole body though it has neither legs nor wheels. It consists of six segments connected by four pitch joints and one yaw joint. Using these four pitch joints, this robot demonstrated high mobility in sagittal plane. This robot was able to ascend and descend the stairs sequentially, get over the obstacle of 600mm in height and climb the vertical narrow passage. In addition, because it had symmetric structure, it was possible to move backward easily just like moving forward. Even if it became upside down, it was possible to move just like normal posture. But if the robot fell sideways, the robot was not able to move until returning to normal posture. It is necessary to develop some wake-up method of the return of the robot from the state which had fallen sideways. In this study, we propose the wake-up method which uses the yaw joint, and analyzed the wake-up motion of this articulated mobile robot. The proposed motion consists three steps. Firstly, the robot bends its tail in the direction which wants to rotate itself. We call this posture the initial posture. Secondly, The robot rotates the yaw joint to raise its tail up. According to the initial posture, the torque required for the yaw joint is different. By doing so, the robot is twisted internally. Finally, by extending the bended pitch joints, the robot returns to normal posture. In this study, we developed a mathematical model for inchworm robot that was waking up and then analyzed the wake-up motion in terms of required torque for yaw joint. The required torque was different depending on initial posture. Decreasing the angle where the third pitch joint rotates, a space necessary for the wake-up motion became small, but required torque for the yaw joint became exponentially large. It is necessary to set initial posture in proportion to the starting torque of the motor equipped in the yaw joint. When the angle of rotation was set to ?2.001(rad), required torque became most small. It was confirmed that the robot returned to normal posture in 4.02 seconds in this case.

EFFECT OF CUTTING FLUIDS ON CUTTING FORCE AND SURFACE INTEGRITY IN ULTRA-PRECISION DIAMOND CUTTING
　　K. Okuda, M. Hasegawa (Tajima Technical Institute), M. Takagi, M. Nunobiki
　　Progress of Machining Technology, Vol. 6, pp.201-206 (2003)

　This paper describes the effect and the action mechanism of the cutting fluids on cutting force and surface integrity in the ultra-precision diamond cutting of aluminum. Kerosene and oleic acid are applied to the workpiece and the tool by three methods with the mist and the drops of fluids and the coating on pre-cut work surface. Oleic acid is used to examine the coating effects of organic polarity substances known as Rebinder effect. In the condition of applying the cutting fluids, the cutting force was reduced from 15% to 30% and the Ra was improved to half the roughness comparing with those in dry cutting. The degrees of the effects were almost same in any supply methods of cutting fluids. The supply method by coating on the pre-cut surface is effective in the diamond cutting from the economical and environmental points of view.

STUDY ON HIGH QUALITY CUTTING OF STAINLESS PIPE BY CO2 LASER MACHINING
　　K. Okuda, M. Hasegawa (Tajima Technical Institute), M. Nunobiki
　　Progress of Machining Technology, Vol. 6, pp.408-413 (2003)

　This paper deals with the machining property and quality in a CO2 laser cutting of stainless pipe with small diameter. In order to investigate an influence of laser beam pass on the cutting process and the finished quality, the experiments of CO2 laser cutting are carried out under the various machining conditions. The roughness of cutting surface, the taper ratio and the heat-damaged layer are measured and evaluated. The cutting surface of stainless pipe with a good quality is not finished under the conditions commonly used in laser cutting of stainless sheet. As for the first half of cutting surface, the qualities are inferior to the remainder of surface. It is found that cooling the cutting part of pipe is effective to obtain the cutting surface with a uniform quality over the whole round surface.

STUDY ON STATISTICAL CHARACTERIZATION OF ANISOTROPIC ENGINEERING SURFACE
　　M. Hasegawa (Tajima Technical Institute), K. Okuda, M. Shirayama (Ishikawa National College of Technology), M. Nunobik
　　Progress of Machining Technology, Vol. 6, pp638-643 (2002)

　The statistical properties of machined surface influence greatly the mechanical phenomena between surfaces. This paper deals with a new method for evaluating the statistical properties of anisotropic random surface roughness. The 2nd and 4th order spectral moments of the profile can be estimated by the ARMA. Then, the surface spectral moments can be also calculated by the profile spectral moments. By use of the these parameters，a new method for evaluating the three dimensional characterization of machined random surface is presented . This method is proved to be useful by the comparison with the results obtained by analyzing the belt sanded surface and the ground surface.

レーザ変位計を用いた研削切断砥石作業面の評価
　　中西佑二（東京都立高専），長谷川素由（但馬技術大学校），奥田孝一
　　2002年度砥粒加工学会学術講演会講演論文集，pp.107-110．(2002)

　研削切断加工において，砥石作業面の性状を明らかにすることは，切断砥石の切れ味を予測する上で重要である．本研究は，切断砥石のように比較的粗い砥石作業面の凹凸を非接触で測定できるレーザ変位計を用いた研削切断砥石作業面トポグラフィ観察装置を試作し，これを用いて高さ10mm，幅25mmの炭素鋼（S45C）を送り荷重100N，砥石周速度3600m/minの条件で定荷重研削切断したときの切断砥石作業面の断面形状の尖度，歪度の大きさから，切断所要時間や砥石摩耗速度などの研削切断特性の変化を説明できることがわかった.

超精密切削加工における切削油剤効果に関する研究―工具温度上昇に及ぼす影響―
　　奥田孝一，丸岡修，布引雅之
　　日本機械学会No.02-25第4回生産加工・工作機械部門講演会講演論文集，pp.167-168(2002)

　This paper describes an effect of cutting fluids in an ultra-precision diamond cutting from viewpoint of temperature distribution of cutting tool. The diamond cutting tests of aluminum were carried out by supplying kerosene in three methods of the oil mist, the oil drops and the coating on pre-cut surface. By using the infrared camera and the image processing unit, the temperature distribution on the rake face of diamond tool were continuously measured during cutting. The supply methods by the oil mist and the oil drops extremely decrease the temperature rise, while the reduction of about 40% occurs in case of coating kerosene on the pre-cut surface.

マグネシウム合金のＣＯ₂レーザ溶接に関する研究
　　奥田孝一，布引雅之，瀬能祐子（三菱電機エンジニアリング）
　　姫路工業大学大学院工学研究科研究報告，No.55, pp.27-31 (2002)

　This paper deals with the welding property of magnesium alloy by CO2 laser. In order to investigate an influence of welding conditions such as laser power and feed speed on the welding quality, the experiments on CO2 laser welding of magnesium alloy are carried out under the various welding conditions. The quality, heat-damaged layer and strength at the welded seam are observed and measured. And the effect of welding methods in the butt-welding of sheet material is examined. It is found that the quality of the mating surface and the accuracy of position greatly affects the shape and the mechanical strength at the junctions of sheets.

インチワームロボットの匍匐動作に関する研究
　　布引雅之，奥田孝一，長谷川素由（但馬技術大学校）
　　姫路工業大学工学部研究報告，No.55A，pp.32-37 (2002)

　In this study, an inchworm-type mobile robot has been developed for purpose of searching for life in a disaster-stricken area immediately after an earthquake. This robot consists of only six segments connected by four pitch joints and one yaw joint. Although, the robot has neither legs nor wheels, it is able to creep to move. It has the sufficient mobility to ascend and descend stairs, get over large obstacles and climb up vertical narrow passages. We developed four creeping manners: wave mode, worm mode, accordion mode and swing mode. The mobility of each walking manner was investigated in terms of walking velocity and consumed energy for a unit displacement. Worm mode locomotion was most rapid and efficient manner. Swing mode locomotion was rapid but inefficient manner. Accordion mode locomotion was slower and inefficient manner. Wave mode locomotion was slower locomotion but more efficient than worm mode locomotion in low speed range. Worm and accordion mode locomotion depended on the condition of floor surface, but wave and swing mode locomotion were not influenced.