超電導磁石を使用した誘導反発式の磁気浮上式鉄道では,最も代表的な設備に超電導磁石およびその冷凍設備等がある.これらの設備は,十分な管理の下に精度良く製作されることが必要条件ではあるが,極めて特殊な精密技術を要する程のものではない.
浮上式鉄道の開発は,これまでの宮崎実験線を中心とした実験を通して高速走行に適した方式であることを実証してきた.今後は,現在の実験車両による各種の実験を通して問題点の把握とその対策を進めるとともに,各機器の信頼性の向上に努めていく予定である.

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This paper reports new servo control technology to realize high precision and high speed machining of machine tool. The conventional analogue servo control technology, due to its generic errors such as non-linearity, offset (drift) and insufficient resolution, has its limitation in high precision and high speed machining. A full digital servo control method, a high resolution absolute position encoder and brushless servo motors have been developed and the high resolution of 0.1 μm and high speed machining of 56 m/min have been achieved.

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This paper attempts to investigate the relationship between the sampling interval and the order of Autoregressive model for estimating the properties of three dimensional surface roughness by use of computer simulation. To check the validity of the order of AR model and the sampling interval, a comparison of the postulated model with the computer simulation was carried out on the number of the zero-crossings, the peaks and the density of summit of the three dimensional surface model. As a result of computer simulation, the suitable order of Autoregressive model for estimating properties of surface roughness is considered to be 7th less than FPE estimation. It is also suitable that the sampling interval is divided a asperity into about 10.

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This paper describes a procedure for the machining of a mold cavity with scanning data obtained from measuring by a convex master-model. The proposed method performs that work by the computational work substituted for the traditional one. The procedures consists of (1) reconstruction master-model shape by scanning data, (2) reversed shape operation, (3) creation offset surface. The scanning data is considered to be the same as the offset surface. But if the master-model has information of shape corner which is less than the probe radius, then the scanning data is not a completely offset surface. Therefore, the master-model shape cannot be completely reconstructed by moving the probe shape on the scanning data. To solve this problem, a method, which makes it possible to reconstruct the shape corner which is less than the probe radius by using the special reproducing probe shape, is proposed. To create the offset surface for the reversed shape, the inverse offset method which has an ability to make an offset surface as a relation between the required shape and any tool shapes, is employed. The machining of mold cavity from the scanning data of convex master-model is possible by using these procedures to a necessary level of accuracy.

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Methodologies for greatly improving machine structural dynamics are presented in which design sensitivity analyses and evaluative parameters are used according to the fundamental procedures of the design optimization method based on clarification of competitive and cooperative relationships between characteristics. First, design sensitivity coefficients and evaluative parameters of structural dynamics are described. Then, design improvement methods of structural dynamics are proposed for the following three cases : (1) addition of elastic structural members, (2) addition of mass elements, and (3) substantial changes of joint design variables. Cases (1) and (2) correspond to the changes of the initial framework or configuration, and case (3) corresponds to the alteration of poor initial design variables. Finally, the methods are demonstrated with numerical examples for a machine tool structural model.

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非接触支持走査形フレキシブルディスク装置の設計法を確立するため,片側をポケット軸受支持されたディスクの浮上特性解析法を提案した.また実験により解析結果を検証し,以下を明らかにした.
(1) ディスクに加わる重力と空気の慣性力を考慮した解析により,ディスクの変形パターン,最大変形位置,最大変形量を定量的に評価できる.
(2) ディスクの遠心力による応力,面外の慣性力,初期応力の影響は無視できる.ヤング率に関しても,±20%程度の等方的変動の影響は無視できる.
(3) ディスク変形および空気圧力は以下の特性を示す.
(a) 最大圧力はステップ上で,最大変形はその1/4波長下流で発生する.
(b) ハブ高さに対して最大変形は下に凸の傾向を示す.またハブ高さが小さいとき最大浮上量はハブ高さによらず一定値をとる.

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This paper deals with two- and three-dimensional analyses of the distribution of sound pressure levels around two kinds of boxlike enclosure models to cover noise sources. One has a circular aperture on its side and a loudspeaker inside, the other has two circular apertures on its two adjacent sides and two loudspeakers inside. In the case of two-dimensional analysis, considering the difference between the distance attenuation of cylindrical waves and that of spherical ones, the sound pressure levels calculated are corrected in order to obtain those in the three-dimensional field approximately. All the calculated results are compared with those measured in detail through a sound visualization method using three color-light-emitting diodes. The results obtained by the three-dimensional analysis agree fairly well with the measured ones. The results of the two-dimensional analysis used show that for the case when the height of an enclosure model is small and the frequency of sound is low, the accuracy of the calculated results of the sound pressure levels in the back region of the model are not satisfactory. In other cases, however, the sound field around such a model can be estimated sufficiently by the two-dimensional analysis with the correction of distance attenuation.

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The purpose of this research is to estimate quantitatively the depth of fine scratches in mirror surfaces, such as the surfaces of magnetic memory disks and laser mirrors. Bechmann's Kirchhoff Approximation, namely the theory of the scattering of electromagnetic waves, is adopted for measuring the depth of scratch. It is estimated by the linear relationships between the scratch depth and intensity-related factors representing the typical characteristics of the scattering intensity distribution obtained by computer simulation. The results obtained are summarized as follows. Firstly, the computer simulations and the experiments show that the depth of fine scratch can be estimated by introducing Bechmann's Kirchhoff Approximation. Secondly, when we approximate the scratch profile to a triangle profile, the depth of scratch is larger than 0.25 μm if the two peak intensities of the scattering distribution, which are seen in almost symmetrical location to the direction of specular reflection, are larger than the intensity of a 45 deg scattering angle. On the other hand, the depth of scratch is smaller than 0.25 μm if they are smaller than the intensity of a 45 deg scattering angle. Finally, it is verified experimentally that the depth of scratch from 0.1 to 1.3 μm can be measured within an error range of about 30% by this method.

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The membrane touch panel is gradually becoming more popular and it is necessary that the optimum design based on theoretical analysis is used for developing the high resolution and high reliable touch panel. In this paper, the touch force needed for the sheets of membrane touch panel to come into contact, P₀, is analyzed theoretically using the model of continuous plate supported by array of dot spacers placed at a pitch. As a result, it is shown that the numerical solutions calculated by the deflection equation of the continuous plate model approximately agree with the experimental results. It is also clarified that the touch force P₀ depends on the ratio of spacer height to sheet thickness, the ratio of sheet thickness squared to spacer pitch and the spacer pitch ratio. Moreover, it is found that the touch force P₀ at the neighborhood of lines connecting spacers is corrected effectively using the infinite length band-plate model.

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A fully automatic system for the seedling transplantation process was investigated as the first study of the automation for the plant tissue cultivation, is a representative technique in biotechnology. As a result, the transplantation robot called 'Mericlone robot' drived by the shape memory alloy actuator, the plant-antenna sensor for detecting a seedling position and the seedling growth state discriminator employing the color sensors were conceived and developed. Furthermore a microcomputer-controlled seedling transplantation system was developed by integrating all the above prototype devices. This system yields success in soft grasping, planting, and unplanting the seedlings of diameter 0.5 mm and length 20 mm, at 15 mm spacing into the culture medium without damage to the seedlings.

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The actual circle radius decreases remarkably for high feed rates of NC machine tools during circular interpolation motion. This decreasing error ΔR is caused by delay factors inherent in the NC servo control system, expressed by the equation ΔR=(Ts²+Tp²)F²/2R, where R is the circle radius, Ts is the time constant of the smoothing loop, Tp is the time constant of the positon loop, and F is the feed rate. A feed forward control method that changes the interpolation vectors, and therefore is consistent with the conventional NC system, was developed to compensating for this error. The results show that the error was decreased in magnitude to one tenth of ΔR by this method when the feed rate was kept constant. The feed rate can be increased three times before the same error of ΔR appears.

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製品の強度は平均値が高く,ばらつきは小さい方がよいという考え方に基づき,溶接強度をその平均値とばらつきの大小に分けて評価し,以下の結果を得た.
溶接強度の総合的な評価はきわめて複雑ではあるが次のような特徴的な点が検出された.
(1) 強度特性値として得られる計量特性値は,
η₁=10logV_m
η₂=10log1/rV_m-V_e/V_e
とした2指標をもとに,平均値とばらつきに分けて評価し,さらに寄与率に変換することにより明確に比較される.
(2) 評点や等級分類値は精密累積法により分析し,その結果を寄与率に変換,(1)の結果と対照して評価することができる.
(3) 溶接の熟練度の差は,外観検査の評点,疲労強さ及びそれらのぼらつきに大きな効果を与える.例えば応力繰返し数10⁶では,疲労強さで約60MPa,η₂で約11～16dB(変動係数が3～6倍)熟練者の方がよいという結果を得た.
(4) 溶接部を直接調べることになる衝撃試験や曲げ試験は,溶接棒の違いの効果は大きいが,熟練度の差の検出力は大きいとは言えない.
(5) 外観検査や曲げ試験では,判定結果における判定者の違いが有意に出た.この個人差を除くための研究がさらに必要である.
これらの結果は通常の強度試験よりは,かなりの普遍性があると思うが,企業全体で行われている溶接作業全体をカバーするものではない.しかし,この結果を通して,多元的な強度評価という考え方の重要性とその結果の多様さはある程度明らかにされたと考える.今後,このような考え方が溶接関係者の間に導入されることを期待する.
本研究は,工業技術院が主催する機械金属連合部会の中で,計量研究所が担当する計測分科会試験評価技術研究会(現在の先端評価技術研究会)の共同研究の一環として,同研究会の出席者及びその所属機関の協力により実施されたものである.

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For the further development of the FMS systems, this paper reports about a new measuring system developed for the multi-purpose understanding of the geometric features of cutting tool edges having serious influences on the machining outputs. In this system, to detect 3D features of both tool face and tool flank only from the 2D microscopic observation of the tool face and describe an overall 3D geometric feature of the tool edge as a digital 2D image, and also to enable non-expensive system development, two convenient measuring principles are utilized, that is the scanning optical section method for the tool face contour mapping and the cutting edge profile comparison method for the flank wear land estimation. Based on these, an experimental hardwear was arranged and various processing softwears were developed, and also they were applied to an observation of the cutting edge wear development in some cylindrical turning experiments, to show that various effective cutting edge parameters could be easily extracted from the integrated tool face image recorded and that sufficient accuracy and resolution for practical use could be obtained.

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Several experiments were run to clarify the relation between blasting conditions (grit size, velocity of grit and blasting angle) and influences for work. In this paper, stock removal, hardness distribution, half width and surface residual stress are discussed. Stock removal produced by normal blasting is in proportion to about square of blasting time and also size and velocity of grit. Stock removal by oblique blasting is more than that of normal one, but the ratio of blasting time exponent on stock removal decreases from 2 to 1. 2.

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The mechanism of chip formation and the machinability of fine ceramics are investigated by both honing operation and scratching test using a conical diamond tool. The workpieces are alumina Al₂O₃, silicon nitride Si₃N₄ and silicon carbide SiC which are sintered under atmospheric pressure, and borosilicate glass (SiO₂). Based on the experimental results which were done by the authors, the specification of the diamond sticks is decided to obtain superior honing performance. The results are as follows. The machinability of work materials is best in SiO₂ and deteriorates in the order of Al₂O₃, Si₃N₄, and SiC. Comparing the shape and size of chips made by honing with the grain structure of Al₂O₃ and Si₃N₄, it can be estimated that the chips are mainly formed by the fracture occurred along the grain boundary, although chips of Si₃N₄ are also formed by the fracture occurred through the grain. Two types of material removal are observed depending on the load acting on the cutting grits. When the load is small, the cutting grits are in the condition of wear and the surface roughness of the work material is improved. When the load is set above the critical value, a lot of chips are created and there remains many large craters on the surface honed.

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In the preceding paper, it is shown that an optimally designed dynamic damper is effective in improving the dynamic stiffness of surface grinding machines and in suppressing the chatter marks caused by the tuning-fork mode vibrations of the machines. The dynamic characteristics of the machines, however, depend on the machine settings, e.g., the height of a wheelhead, the position of a work table and a saddle, etc. Therefore, it is supposed that the optimum conditions of the damper are difficult to keep. The present paper aims to develop a dynamic damper which has an excellent adaptability to the variation of the dynamic characteristics of the grinding machine during manufacturing operations. To this end, a multi degree-of-freedom two direction type dynamic damper is designed and its effectiveness is investigated experimentally. It is found that the newly developed damper has the good adaptability and is effective also in suppressing the horizontal vibrations caused by the shock due to the reversal of the work table.

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Transient variation of impact and thermal stress fields, and temperature distribution as well, within cutting edge during the edge engagement in interrupted turning were first obtained through FEM calculation using measured variation of impact cutting force and temperature on rake face. The probabilistic stress criterion of brittle fracture and its variation due to repetition of impact stress for each location within the tool edge using the deterioration rule reported in previous paper were next obtained. In collation of the most dangerous state of the transient stress with the fracture criterion at each element, variation of fracture probability distribution within the cutting edge with number of the interruption was predicted. Thermal stress had the effect to decrease the failure probability, while temperature rise did promote the probability. The predicted relation for edge failure occurrence shows good agreement with experimental results. It is also possible in practical manner to predict the edge failure for the tool with rounded or chamfered edge by applying a suitable flank force to the edge.

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In the 3rd part of this investigation a cutting model with restricted tool-chip contact length, which represents the formation of a helical chip produced by the chisel edge, was proposed. By specifying the frictional stress on the rake face of the chisel edge, the model enables to predict the chip formation, and torque and thrust force through the energy method. To evaluate the condition on the rake face, two-dimensional cutting experiment was done with fairly negative rake angle tools having differently restricted tool-chip contact length. It is clear that the value of frictional stress on the rake face of the chisel edge approximates to 0.2 times the value of shear stress on the shear plane. The torque and thrust force, direction of translational velocity and others are measured and compared with those predictions. On the torque and thrust force, the predicted results are in good agreement with the experimental results.

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研削油剤の性能をいかに評価・表示するかという観点から,調整したアクリル系ポリマ研削油剤を用い,一次・二次性能を評価項目として油剤の性能指標に関する検討を行った.その結果,次のような結論を得た.
(1) 研削加工の進行に伴い,砥石摩耗曲線は初期摩耗から定常摩耗への特徴的な変化を示し,その初期摩耗と定常摩耗との移行点は,研削動力の極値に対応するので,これを評価点とすると良い.
(2) 研削油剤の効果は性能項目ごとに異なるので,加工方法,基準油剤,油剤性能指標を組み合わせて総合的な表示を試みた.また,その性能指標は改善率を用いて数値化することにより明りょうに表される.
(3) 改善率を用いた性能指標は,削除速度を変化させてもほとんど変わらず,この評価法の汎用性が確認できた.
(4) アクリル系ポリマ研削油剤を性能指標評価法により評価したが,この油剤の実用性が確かめられた.

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The electrolytic current in machining steel with wire-EDM causes corrosion and may attack microstructure and/or decrease the hardness on its machined surface. This paper describes growth process and metallurgical influences of the electrolytic corrosion. The results obtained are summarized as follows : (1) With relaxation generator, the electrolytic corrosion is formed under normal polarity but not under reverse polarity. (2) Mostly the corrosion starts from pits or micro-cracks caused by electric discharge and later it grows up to inside. (3) The structure neighbouring to the corrosion loses its own hardness. (4) Since the electrolytic current changes linearly to the conductivity of the dielectric water, machining with higher water conductivity gives larger scale corrosion.

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This report describes a newly developed compensation-method for the electrode-deformation in contouring electric discharge machining with cylindrical electrode. The compensation value is predictively calculated by using self-learning algorithm and the data measured during the machining process. Based on the calculated value, compensation cut is given progressively between the measuring points. When the accuracy of prediction is sufficiently high, the interval between measuring points is extended. In order to confirm this algorithm, computer simulations are executed using several practical machining-data which were previously measured for horizontal plane, inclined plane and hemisphere machining. Main results are as follows : (1) Accuracy of prediction is within 10 μ m except for few cases including large fluctuation. (2) Compensation-modulus is improved more than double compared with that obtained by the conventional method.

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