This paper describes the methodology of how to derive the removal shape element for NC machining from CSG model utilized commonly to various applications. An approach to establishing the CAD/CAM interface based on the geometry model must be effective to realize an integrated CAD/CAM system. From the point of realizing a CAD/CAM interface system mentioned above should be established the method for generating intermediate data which connects a machining data information to a geometry model. Here, CSG modeler TIPS-1 is adopted for this purpose and the NC machining oriented geometry data, which should be constructed by a set of the shape elements, is generated automatically from the 3-D geometry data of TIPS-1. The procedures are the following. (1) Translation of CSG model to B-Reps. (2) Extraction of characteristic shape unit on the machining by utilizing topological data of B-Reps. (3) Decision of intermediate shape in each step of machining. Thus, the removal primitive has the machining shape and the removal range can be obtained automatically from the geometry model.

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This paper presents the relationship between the clamped force and the values which show the nature of the dynamic characteristics of a beam containing the junction. The values are the damping ratios, effective stiffness, compliance of the resonance frequency and natural frequency of the 1st and 2nd mode with the beam. The beam with one fixed and other end free is used in the experiments. The beam is clamped by a pair of specimens with the asperity on the surface. Also, FEM is applied to estimated the values of the characteristics theoretically. Herzian theory is applied to calculate the stiffness of the roughness on the specimen. The damping ratios are calculated using the effective stiffness and the compliance of the resonance frequency as the frequency response diagram of the beam containing the junction is given approximately by superposition of a second-order system. The natural frequency and effective stiffness of the each modes increase with and the damping ratios decrease with stronger the clamped force. These theoretical values have the similar tendency and is approximately equal to the experimental one.

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Dynamic simulation method of high speed cam mechanism is newly proposed to improve the defects of known analytical simulation methods. In this method, preliminary experiments on dynamic properties of cam mechanism itself are carried out in the same manner as its practical use, and their experimental results are analyzed by conventional FFT analyzer. On the basis of the natural frequency obtained as the above and other dynamic quantities by known methods, the dynamic properties are simulated by one mass model irrespective of the structure of its mechanism. Then, the follower motion and the cam contacting force are simulated by utilizing the model, and their simulated results are compared with their experimental results. As a result, it is ascertained that this simulation technique is usefull except follower jump phenomena.

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A pair of internal gear with straight line tooth profile and mating pinion with approximated circular arc tooth profile has been proposed to produce easy manufacturing of accurate internal gear. Already, it was clarified that these internal gears have a fairly good performance for motion transmission. In this report, the power transmitting capacity of proposed internal gears is investigated by the running test, and calculation of Hertzian contact stress and specific sliding. It is concluded from these results that proposed internal gears have almost same power transmitting capacity as compared with conventional involute tooth profile internal gears.

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In this paper, the postbuckling behavior of a column with nonlinear stress-strain characteristics is analysed by means of a catastrophe theory. As a result, it is shown that the postbuckling behavior of the column with linear stress-strain characteristics is modeled by the cusp catastrophe. Moreover, it is clarified that the postbuckling behavior of the column with nonlinear (symmetric and cubic) stress-strain characteristics must be analysed by the butterfly catastrophe.

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Although stylus profilometers are now widely used, recent development of single point diamond turning and semiconductor technology strongly require to come out non-contact precise surface sensors. This is mainly because the stylus may scratch the surface of soft metal, thin film, silicon wafer, and so forth. Some non-contact surface measurement methods have been developed. Most of them, however, are complex, expensive, too large, low resolution, or simply hard to handle. Applying the principle of focus detection by critical angle of total reflection, a practical non-contact sensor to measure the surface roughness or the micro-figure of diamond turned metal mirror is developed and named HIPOSS-1 (HIgh Precision Optical Surface Sensor-1). HIPOSS-1 shows 20 nm resolution about vertical direction and is so compact and light weight. And it is interchangeable to a pick-up head of stylus profiling instrument.

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The study deals with the method of recognizing bearings of workpieces and the development of scraping mechanism in the light of the automation of scraping works, which take considerable skill and much time. Bearings of workpieces matched with the referenece surface are detected by a CCD line sensor. Based on the bearings, the microcomputer judges where to be scraped. The scraping mechanism is devised to rub out the recognized plateaus of bearings of workpieces intermittently by an elastic grinding wheel equipped with the detector of contact moment. The system is proved to have the potential of rationalizing scraping works from experimental results.

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The pitch accuracy of the precise machine elements such as gear, screw and rack having periodic shapes, is very important in their performance. In order to measure the pitch accuracy, in this study, a non-contact measuring method is proposed for the screw pitch error utilizing thermoplastic hologram instead of silver-halide plate hologram, and then the possibility to realize this method is experimentally investigated. The experimental device is constructed by combining a thermoplastic recording system, a laser generator, an optical system, a laser length measuring system, a desk-top-computer, a carriage and so on. The thermoplastic hologram is made as follows : The thermoplastic plate is exposed with the reflected beam from the flank of the screw thread and the reference beam, and then developed by a electrifier. The pitch signal is obtained by illuminating the hologram with both signal and reference beam, and the positional pulse is obtained through the electric circuits. The obtained main conclusions are as follows : (1) The pitch signal can be detected not only at the flank where the hologram was recorded, but at the other flanks. (2) The non-contact measuring system for the screw pitch error was constructed based on this method. The repeatability for the measurement of the screw pitch error is 0.3 μm in standard deviation.

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It has been shown in machining SUS 304 that the pitch of saw-toothed chips decreases with increasing tool wear and the increase in the frequency of chip segmentation with tool wear is related to the shear strains on the shear plane. The cutting tests have exhibited that the increase in the frequency is mainly caused by an enlargement of crater, flank wear and roundness of cutting edge. An experimental equation is presented to express the frequency, when SUS 304 is interruptedly cut with high speed steel tools. The frequency for the sharp peak in the power spectrum of the interrupted cutting forces was approximately equal to the value calculated by the experimental equation. It is indicated that the variation of the frequency in the formation of the saw-toothed chip is applicable for sensing tool wear.

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An overcut fly-milling test with inclined workpiece has been made to accurately evaluate the chipping and wear characteristics of superhard abrasive grains (diamond, CBN) on various hard materials. The Al₂O₃ and SiC grains were also tested for comparison. The milling experiment was carried out on a surface grinder at a speed of 38 m/s and a feed of 4.0 m/min. The maximum depth of cut was 110 μm. The test was conducted both in dry and wet. The work materials used are hardened SUJ 2, cemented carbide, sintered alumina, etc. Thus, a quantitative evaluation of the chipping and attritious wear was made for each grain by tracing across the grooves with stylus instrument. The data obtained has been treated statistically. The CBN grain proved to be the most resisting to the chipping and attritious wear for the cutting of SUJ 2 steel, and hence, has the highest G-ratio. But, this grain has no ability to cut the cemented carbide or the ceramics used. As far as the diamond grain is concerned, the lowest G-ratio was obtained in the grinding of cemented carbide, followed by sintered Si₃N₄, and the highest G-ratio was obtained on grinding silicon. The supply of grinding fluid leads to finer chipping and higher chipping probability.

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There are materials including austenitic stainless steel plate (SUS 304, 18%Cr-8%Ni) that can cause problems when cut by the conventional laser-gas-cutting method, those being, some dross cling to the bottom edge of the cut plate, and that a subsequent dross removing process will be needed resulting in a cost increase. In order to solve this problem a new method has been developed which can realize a substantial dross-less CO₂ laser-gas-cutting of SUS 304 as well as other materials subject to the above problem. The present method, "Tracing cut", is based upon the idea that if the melt flow of the material causing the dross formation on the plate bottom edge can be blocked or bypassed by any means, the flow could be rendered harmless in regard to undesirable dross cling. This paper describes the principles and experimental results clarifying the characteristics of the present method.

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For the breaking of chip in metal cutting, chip-breakers equipped on cutting tool are not almighty but effective only in limited range of cutting conditions. In the continuous cutting operation of ductile metals, such as the turning of steel, especially when the operation is automated, the selection of appropriate chip-breaker and of the conditions for chip breaking are extremely important. There have been, however, very little information available on this subject. In this report, a series of cutting test on 0.45% C steel using the carbide tool with parallel groove chip-breaker reveals the following conclusions : (1) In most cases, the range of chip breaking can be indicated both by the lower boundaries of the feed and the depth of cut. (2) The absence of and the reverse direction of the side curl of chip are unfavorable for the chip breaking. (3) The lower boundary of feed is varied not only by the cutting speed, width of chip-breaker groove and approach angle, but also by the corner radius of cutting tool. (4) The lower boundary of the depth of cut is roughly equal to the corner radius of cutting tool, but is independent from other conditions.

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In order to determine the optimum radius and the limit of usable radius of grinding wheels in cylindrical plunge grinding, effects of the radius ratio and the wheel radius upon grinding forces, wheel wear rate and surface roughness are experimentally investigated. Main conclusions obtained are as follows : (1) Grinding forces increase rapidly under constant rotation ratio, but hardly increase under constant speed ratio with increasing radius ratio. (2) Even though all of cutting conditions of each grain are held constant, grinding forces increase with an increase of the wheel radius. On the other hand, grinding forces are held almost constant under constant speed ratio and then constant number of wheel rotation. (3) The optimum radius of grinding wheels for each grinding result depends on grinding conditions and the limit of usable radius of grinding wheels becomes maximum under variable relative speed and constant speed ratio from the viewpoint of grinding forces.

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小型平面研削盤に用いられているV-平ボールガイドの負荷分布式をたて,テーブルの案内精度や負荷分布の変動状態および工作物の精度などについて検討を加えた結果を要約すると,次のようになる.
(1)V-平ボールガイドでは,その構造上必ずテーブルのローリング変位成分が入る.
(2)テーブルの案内精度を高くするための,V側案内面玉数に対する平側案内面の最適玉数が存在する.
(3)V溝の角度は鋭角より鈍角にするほど高精度となり,サドル案内面には最適中低量値が存在する.
(4)サドル案内面を中高にすると,自機研削後の電磁チャック上面の形状はやはり中高となり,JIS許容値内に入らなくなる.
(5)玉径相互差はそれほど問題としなくてもよい.むしろ,ボールガイド内の玉並び状態を両端から中央へ行くに従って小径の玉にするよう配列することが精度追及上有効である.

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