Yasuyuki Kamimura

Single-point machining technology of a supersmooth surface using a flying tool

Single-point machining technology using a flying tool has been proposed in order to turn a supersmooth surface independently of error motions on the machine tool in use. In the process, a discoid slider with a sapphire chip follows the prefinished surface by the action of a hydrodynamic bearing. The cutting mechanism of the technology was investigated: the height of the cutting edge was maintained between the peak and the valley of the surface roughness so the surface finish was improved due to the truncation; the cutting depth was varied following the vertical acceleration of the workpiece surface with small delay, which may improve the waviness.

Ductile Regime Cutting of Brittle Materials Using a Flying Tool under Negative Pressure

Abstract The importance of ductile regime cutting has been emphasized in the production of large-diameter optics and semiconductor substrates over the last ten years. However the available technology has not yet been implemented in industry. The reason is that cutting technology based on the motion-copying principle is too sensitive for error motions of a machine tool to maintain the actual depth of cut stably below the critical depth. A new cutting technology using a flying tool under negative pressure has been developed. In this technology, a flying tool glides over a workpiece surface while maintaining a small height like a negative-pressure slider of a magnetic disc drive. Using the tool system, ductile regime cutting of optical glass and monocrystalline silicon was examined, and a mirror-surface finish with no cracks was achieved on a face lathe having a 0.1μm order of error motion.

Development of high-speed and high-accuracy straightness measurement of a granite base of a CMM

Abstract The flatness of a granite base affects the volumetric accuracy of a probe in a CMM. Therefore a new optical straightness measurement with high speed and high accuracy is proposed in this paper. High speed was attained by gliding the measurement head over the granite surface through the action of an aerostatic bearing pad. High accuracy was obtained by measuring the position of a laser beam on photodetectors. The straightness was estimated in terms of the vertical displacement and the integrated inclination of the slider, and the latter coincided well with the value measured using an electric level.

On-Machine Measurement of Form Accuracies Using Two Quadrant Photocells.

It is necessary to separate the components of the error motions in the measuring system in order to measure the surface profile of a spherical mirror on a machine. In this paper the new optical system has been developed to measure the displacement and the inclination angle of the reflected surface at the same time. Namely, the displacement was measured by applying the principle of triangulation, and the angle was measured by applying the principle of optical lever. The surface profile was obtained through the integration of the angle, and the error motion was derived by subtracting the profile from the displacement. The results showed a higher repeatability and a higher reliability in comparison with the results measured by using other optical methods.

Development of a Dicing Blade with Combined Structure Utilizing Photocurable Resins

工作物を高能率で切断するため,スロット付きセグメン トタイプのダイヤモンドカッタが広く用いられている.ス ロットの存在が切り屑の逃げ場を提供し,自生発刃作用を 活性化させ,加工液の加工点への浸透を高めるなどの理由 で,切断抵抗や切断温度の低下に効果があることがよく知 られている.また,切断抵抗の抑制は工具の寿命を長くし ている. ダイヤモンド切断砥石には,ダイヤモンドカッタとダイ シングブレードがある.アスファルト道路の切断などに用 いられるダイヤモンドカッタはスロットのある剛性の高い 台金の外周に砥粒層のセグメントが取り付けられている. 現在,外周径が 0.1 mから 3.5 mまでのものが製作されて いる.大口径になるほど台金の高速回転によるアンバラン ス等による横揺れが起こり易く,剛性の低い厚さ 1 mm以 下のカッタの利用は困難とされている.一方,半導体部品 に使用されるシリコンウェーハやセラミックス,水晶など の硬脆材料の切断に利用されているダイシングブレード は,外径が 50 mmから 150 mm程度のもので,カーフロス を低減させるため厚さが 0.2 mm以下の薄いものが一般的 に使用されている.そのため,通常刃物全体が砥粒層で構 成された一体構造をしていて,オールブレードタイプある いはコンティニュアスタイプと呼ばれている.しかし,従 来の熱硬化性樹脂からなるダイシングブレードは,高温の 熱を加える工程において熱収縮と反りが生じ,薄形のスロ ット付きブレードの製造はできないと考えられてきた.こ れに対し,著者らはブレードの結合剤に光硬化性樹脂を用 いることでこの問題を解決し,極薄ブレード(1)および 三層ブレード(2)の開発を行った. 本論文では,光硬化性樹脂を用いたブレードの高性能化 を果たすために,光透過の制御ができるマスクを活用して, スロット付きブレードの製作を検討する.さらにスロット 付きブレードの切断品質を高めるようなブレードの開発を 行った.これら三層ブレードやスロット付きブレードは, 厚み方向や円周方向に所定の構造を有することから,構造 制御型ブレードと称している.

Development of an electroplated polishing tape applying electrodeposited nickel foil method

Diamond polishing tapes are commonly used for edge finishing of zirconia ferrules. There remains a problem that the diamond tape has too short tool life due to weak bonding strength. Then we propose a new method to make a diamond tape applying electrodeposited nickel foil method. This method is very useful to make a long metal foil continuously and commercially used for manufacturing of a copper foil. In order to improve the tensile strength of the foil, we performed composite electroforming utilizing glass fibers. It was confirmed that the concentration of abrasives could be increased by using Ni-electroplated diamond abrasives. A series of experiments to finish zirconia ferrules proved long tool life of the developed polishing tape.

High-Accuracy Detection Technology of Initial Contact in Ductile Regime Machining.

In order to realize ductile regime cutting of brittle materials, it is important to determine the initial contact between a tool and a workpiece with high accuracy. Thus the detection of initial contact in diamond turning of Al and Si was examined using an AE transducer. The sensitivity and the response speed of an AE signal were evaluated in comparison with those of an electric contact signal. Treatments to improve the conductivity of a diamond needle as a tool and a Si wafer as a workpiece were made in order to determine an electric signal representing the initial contact between a tool and a workpiece. The resistance of 65Ωwas obtained by spattering of a diamond needle using Ar ions. The resistance of a Si substrate was reduced to 300Ω by doping P ions into it. As a result, the detection of initial contact during cutting of a Si substrate was accomplished on the 1O nm level. Moreover, the sensitivity of detection using an AE transducer was found to depend on the impact energy ; thus, the sensitivity was improved with the cutting speed.