精密切削によって様々なマイクロパーツを製作する試みについて紹介した.これらの結果から精密切削は, マイクロ形状創成法として有望であり, 特に複雑な3次元形状部品の製作に対して有効であると考えられる.一方で, 組立てや電子回路との統合などの問題点も抱えており, 今後は他の加工方法と組み合わせ, 各々の特徴を生かすことによりより優れたマイクロ形状創成法を実現してゆくと思われる.

抄録全体を表示

シリコンのマイクロマシニング技術のうち, エッチング技術をつかって実現できる3次元構造体の加工技術について概説した.本稿で述べた内容を表1にまとめた.等方性・異方性, 材料の選択性など, エッチングの特質を利用すればかなり多様な3次元構造体を加工することができる.また, エッチングと他の加工技術を組み合わせて複合化することにより, 微細な3次元構造体の加工 (マイクロマシニング) の可能性はさらに拡大する.
上記の技術の応用を考えるとき, エッチング加工の特長である (1) 微細性, (2) バッチ生産による量産性, (3) 平面上での正確な配列性, を利用すれば, これらの技術はセンサの分野にとどまらず, メカトロニクス分野でも機構部材の微小化, 電子回路と機構部品の集積化などの目的で, 今後さまざまな応用例に発展するものと期待される.
なお, 本解説で使用した写真のうち図5以外は, すべて (株) 日立製作所のご提供による.

抄録全体を表示

短波長用光学素子を生産する超平滑研磨技術および装置CSSPについて解説した.ローカルピッチ研磨法により, 表面粗さ0.2nm RMSの超平滑研磨が非球面においても達成できる。また, 接触式の形状測定方法で3~9nm RMS/φ500mmの繰返し性で形状を測定可能である.3種類のワークについて加工評価し, 目標精度を達成, CSSPの機能を確認した.今後は形状測定の確度を実際の光学素子の生産を通じて検討する予定のほか, 生産コストに関し, 除去レートの向上, 単位除去形状のさらなる安定化が課題である.

抄録全体を表示

新しい駆動方式を採用したマイクログリッパ (FMG) について解説した.本稿によりFMGの駆動特性, 応用の可能性についてご理解頂けたら幸いである.また今後は, FMGの高機能化や, 新たな操作要素の研究開発を進める予定である.

抄録全体を表示

静電容量式と光電式の異なる検出器を組み合わせ, 小型で温度特性など耐環境性に優れた, アブソリュートリニアエンコーダの開発成果を概説した.本エンコーダはすでに量産されており, 生産現場の省人省力化に貢献している.
近年, リニアエンコーダは直動駆動制御装置の位置速度センサとして, 新たなニーズが高まってきている.高トルクが得やすいリニア同期モータ (LSM) の場合, 始動時に磁極の位置検出が必要であり, エンコーダのアブソリュート化による効果が特に大きいとされている.
このようなより高度な要求に対応するためには, 高分解能な検出感度と広い測定範囲, 小型軽量化によるイナーシャの低下, ダイナミック精度向上などの高性能化と, さらなる低価格化を克服していかなければならない.

抄録全体を表示

This paper describes a method for thresholding gray-scale images to produce binary images in real time. It is specifically designed for thresholding images that contain both small, low-contrast defect patterns and relatively large, high-contrast circuit patterns without image deformation. This method analyzes peaks and troughs in the detected signal waveforms to threshold the low-contrast patterns ; it applies the constant threshold technique to the high-contrast circuit patterns. Experiments show that this method can properly threshold images containing both small defect patterns of approximately 20% contrast and circuit patterns of approximately 90% contrast.

抄録全体を表示

本論文では従来の回転スピンドル端面に圧電素子を装着した機構を取り付け, これによりスピンドルの軸方向の並進誤差とスピンドル軸に直交する2軸回りの回転成分を測定・補正する機構の構造と原理および計測制御系について述べた.外部に固定された計測系の座標軸と回転するスピンドル上の制御系の座標軸が回転するため非干渉制御の座標系を動的に変化させなければならないことを指摘し, これを実現するためにプログラマブル可変利得アンプ群を用い, 制御マトリツクスを変化させるアナログーディジタル回路について説明した.実験では回転誤差を大幅に改善し, 軸方向で0,02μm, ティルティング成分で0,5''の精度が得られたことを明らかにした。今後の課題として, 制御コントローラや電気回路素子の改善によりさらに高速な応答性能を実現すること, 参照面の形状偏差を補正すること川, 他の半径方向2成分を補正すること, 正面旋盤や表面形状測定器などに応用することなどについて検討を進める.

抄録全体を表示

An organic nonlinear optical crystal having soft and brittle in nature has been machined by an ultra-precision turning lathe with a sharp diamond tool under various cutting conditions in order to obtain optical surfaces. The finished surfaces can be classified into three categories, that is, fracture mode, ductile mode and ductile & fracture mode, respectively. These surface categories ace remarkably affected with the crystal orientation and rake angle of cutting tool. The turned surface roughness is affected by the crystal orientation, rake angle and feed rate, but not affected by the cutting speed and depth of cut. The optical surface of 1.57nm rms or 12.3nm Rmax in surface roughness and 80nm in flatness has been obtained by using a diamond tool having a rake angle of -20 degree. A 532nm green laser of 1.4mW in output power has been generated by using the diamond-turned chalcone in an intra-cavity SHG device.

抄録全体を表示

This paper deals with some experimental results of the application of a newly developed PVA grinding stone to the lapping process of silicon wafer. The characteristics of the developed grinding stone are, about 30 vol% abrasive content, about 25 vol% resin content and about 45 vol% porosity, and by changing the flow rate of lapping fluid, experimental results are largely changed. Lower flow rate gives higher removal rate and coarser surface roughness similar to the free abrasive lapping process, and the higher flow rate gives lower removal rate and finer surface roughness. The depth of distorted layer is thinner and the surface of lapped wafer is cleaner than that of by free abrasive lapping process.

抄録全体を表示

Considering the principle of minimum potential energy and thermal expansion, atomic array model of fcc metal is constructed at room temperature through the molecular dynamics, where 12000 atoms are arranged in 60 atoms per layer in the direction of width and 200 layers in the direction of depth. It is confirmed that velocity of atoms at room temperature has a Maxwell distribution. A simple model of laser absorption of crystal and a method to estimate stress state of atoms are proposed. Applying molecular dynamics, atomic behavior of copper, aluminum and lead with laser irradiation is simulated. Variation of atomic array and stress state of atoms during and after laser irradiation are shown visually. Main conclusions obtained are summarized as follows : (1) Thermal shock wave travels to interior of material with laser irradiation. Especially, when surface vapors explosively, large compressed-field occurs due to its reaction. (2) Propagation velocity of thermal shock wave is equal to elastic wave velocity. (3) Particles scatter in pieces as relatively fine cluster when power density is higher. On the other hand, the vicinity of surface bounds out forming relatively large lumps when power density is lower. (4) Degree of these phenomena varies with material and depends on the well depth of pair potential.

抄録全体を表示

The goal of this paper is a mirror grinding of ceramic cylinder with an extremely fine grit diamond wheel. An ultra precision cylindrical grinding machine and a truing and dressing device for it are designed and built. For a mirror grinding, a very fine infeed motion and a low vibration are needed to avoid sinking diamond grits into a bond material with an unexpectedly large force on individual grits. Therefore, the grinding machine has a hydrostatic wheel spindle and a hybrid infeed mechanism. The latter one consists of a ball screw and a DC servomotor for a rough feed, and four piezoelectric actuators for a fine feed. The piezoelectric actuators are mounted in the ball screw nut. Vibration amplitude of the wheel head was less than 0.1 μm and the minimum depth of cut was 0.01 μm/step. After truing and balancing a resinoidbonded diamond wheel (SD5000B) on the machine precisely, a mirror grinding of a partially stabilized zirconia cylinder was carried out. A peak-to-valley height of the ground surface was 53 nm and a maximum chipping length on the edge was 0.5 μm or below.

抄録全体を表示

It is known that the distribution of cutting edges on a grinding wheel surface affects much on such properties as finished surface roughness and induced grinding force, etc. In order to estimate this distribution, it was simulated the grinding process so as to match the simulated surface roughness to the actual results obtained by plunge cut test where a carbon plate was selected as the test piece material so that the grinding force may become negligible. It is expected, therefore, that the other grinding characteristics as an elastic deflection of wheel bonds and the machine structure did not affect on the surface roughness. The method was applied to both aluminum oxide grain and CBN wheels after truing and operation and could show its availability.

抄録全体を表示

Temperature of interface between a cutting tool and a workpiece is measured using two-color pyrometer with a fused fiber coupler. A conical tool is used as the cutting tool which is made of translucent alumina sintered under HIP, and 0.55% carbon steel is used as a workpiece. The infrared rays radiated from the interface and transmitted through the conical tool are accepted by a fused fiber coupler and led to two infrared detectors of different spectral sensitivity. Temperature is obtained by calculating the ratio of the output voltage from these two detectors. The results obtained are as follows. The temperature increases very rapidly and reaches 1000°C at about 40 μs after the beginning of cutting. The rate of increase of temperature is very great : about 10⁸ °C/s at the cutting speed of 1 500 m/min. The temperature increases with the increase of cutting speed, but at a speed faster than 1000 m/min its influence is small. The temperature shows a tendency to saturate about 1300-1400°C as the cutting speed increases.

抄録全体を表示

The orthogonal cutting process of the affected layer was simulated by FEM and the influence of the cutting conditions in previous cutting on residual stress and strain in the newly machined surface layer is investigated in this report. In the cutting simulation by FEM, tensile residual stress is usually remained on the machined surface. But the compressive residual stress was caused by finishing after roughing. In this case the shear angle increased and the cutting forces decreased. These calculated results were confirmed by experiment. Hence the residual stress level seems to be controlled by the change of the cutting conditions in machining sequence.

抄録全体を表示

The response of the feed drive system consisting of a CNC controller and a feed mechanism has been simulated by using a simple mathematical model that is a single degree of freedom. However, this model has not been able to represent some behaviors. In this paper, a new model, a multi degree of freedom is proposed. The model consists of a work table, a ball screw shaft and nut, and support bearings. The experimental results demonstrate that the proposed model well expresses the actual frequency response of the work table in the feed direction. The proposed model also has a useful function that friction can be easily introduced to each mechanical component. A model representing friction is also proposed. The influence of friction can not be generally investigated in the feed drive system. The measurement of the circular movement was conducted by using a special equipment. As a result, the simulated circular trajectory was in agreement with the actual trajectory and the quadrant glitch caused by stiction was well expressed.

抄録全体を表示

In order to cut the Ni-based super alloy Inconel 718 with high speed, a TiC whisker reinforced alumina ceramic tool was newly developed. In machining the Inconel 718, while a SiC whisker reinforced alumina ceramic tool showed a good performance in respect to notch wear at cutting speeds of up to 300 m/min, the tool had a large thermal wear at the higher cutting speeds because of its thermal instability to the Inconel 718. A TiC added alumina ceramic tool, to the contrary, indicated good wear resistance even at a cutting speed of 500 m/min because of thermal stability to the alloy, while the tool had a large notch wear at relatively low cutting speeds. Therefore, the TiC whisker reinforced alumina ceramic tool was developed for the purpose of giving advantages to both the SiC whisker and TiC added alumina ceramic tools. However, the tool had damage, mainly chipping, under heavy cutting conditions, while the tool showed good performance for the notch wear at low cutting speed. The reason of the chipping must be that TiC whiskers used in this test had large distributions in size, diameter and length.

抄録全体を表示

一般化ハフ変換を用いた半導体ウエハ識別番号認識装置を開発した本装置は以下の特徴を持つ.
(1) テンプレートテーブルのデータ量を削減するために, 文字パターンの曲線部分に着目して, データ圧縮を行う
(2) マルチプロセノサシステムを用いて, テンプレートテーブルの検索と座標変換計算を並列処理することによって認識時間を短縮する.
(3) 一般化ハフ変換を用いているため, 品位の不良な対象画像であっても高い認識率を得ることができ, また, 文字パターンのわずかな大きさや傾きの変化の影響を受けにくい
(4) 定型フォントであれば, テンプレートテーブルの圧縮率を60%程度としても認識率への影響はほとんど見られない.
(5) 実機へ適用したところ, 認識率98, 6%と認識時間16秒という実用的な結果が得られた.

抄録全体を表示

Usually cam profile machining is done with linear interpolation, which requires a large number of machining data. And if the radius of cutter changes, a new center locus of cutter should be calculated, because the cutter offset function is invalid for the free-form curve. This paper deals with the machining data of a typical parallel index cam with clothoidal interpolation. Recorded clothoidal data can generate clothoid “accompany” curves. With these curves, the cutter path of any radius can be calculated. And thus the cutter offset function, suitable only for linear and circular curves, can also be extended to serve any free-form curves. The amount of the point data with clothoidal interpolation is largely decreased compared with the linear interpolation.

抄録全体を表示

This paper describes a new vision image processing method by using an active sensing with fine camera motion. This algorithm obtains the hint from tremor. Tremor is one of human visual cognitive mechanism and active sensing. The algorithm can make resolution enhance more than a pixel. A photo diode is used as a visual sensor. It takes images, moving vertically and horizontally by stepping motors. Taken image data and movement data are processed by mathematical model for image restoration. As the result, resolution is enhanced more than a pixel. The mathematical model, the developed system configuration and experimental results by using the system are reported in this paper.

抄録全体を表示