Rigid-Polyvinylchloride (R-PVC) cutting mechanism has been studied. Especially, generating mechanism and condition for periodical surface irregularities have been investigated. The cutting forces are affected by cutting speeds and tool rake angle. The maximum cutting forces exist between 4 and 10 m/min cutting speeds which are called critical cutting speeds. At these speeds, the cutting mechanism changes from continuous to discontinuous chip formation. Above these speeds the periodical irregularities are generated on the machined surface by less than 30° rake angle cutting. The periods depend upon depth of cut and the rake angle. Smooth surface can not be obtained at the critical rake angle. Rake angle 30° cutting produces continuous chip, however relatively smooth machined surface has some big damages caused by cracking. The cutting model offered by author can explain characteristic R-PVC cutting phenomena well.

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Polishing of silicon nitride has been conducted by using a newly-developed finishing setup which is able to give the polishing pressure to the workpiece. The polishing is made by using an electrophoresis phenomenon of fine grain in liquid. When the electric power of DC voltage is supplied to the electrode set into the polishing compound, the grain moves and causes the polishing action to the workpiece surface. The polishing pad is put onto the stainless disc electrode. It is found from the experiments that unwoven polishing pad and reddish ferrite grain are suitable for the finishing of silicon nitride. Experimental results show that the stock removal rate increases with both the applied potential and load. The characteristics of surface polished are examined by X-ray photo spectroscopy. Photo electron spectra observed suggest that the mechanochemical actions arise on the surface of silicon nitride during the polishing process.

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This paper deals with the characteristics of drill lateral vibration. The purpose is to make clear the effects of main cutting edges, a chisel edge and margins on the vibration behavior. Experiments were performed in a workpiece-rotating and drillstationary system using the vertical milling machine. The results are as follows : Increasing the working length of main cutting edges decreases the vibration frequency. Chisel edge causes a static instability in the direction of the main cutting motion as well as main cutting edges. The longer a chisel edge gets, the lower the vibration frequency of a drill becomes. Drill margin has a damping effect on vibration.

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In cylindrical grinding operation with spark-out process, the final workpiece shape may be affected not only by the smaller grinding force but also the straightness error of table movement directly. In the present paper, the influence of table straightness error on the final workpiece shape is clarified quantitatively. That is, the straightness error of table is measured with a 3-points method, and the shapes of dressed wheel periphery and of ground workpiece are estimated. The results obtained in the present study are summarized as follows. (1) The straightness error of table movement is transferred to the wheel periphery and the dressed wheel shape depends on the position where dresser is fixed on the table. (2) The workpiece shape ground in plunge cut is affected by the wheel shape and the table positions in operation. (3) In the traverse cut operation, the wheel shape does not affect on the workpiece shape so much. (4) Being based on the straightness error of table movement, the final workpiece shape can be estimated precisely.

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It is known that not only diamond grain but film can be synthesized from gas phase. In this study, when synthesizing diamond from hydrogen and methane mixed gas by microwave plasma CVD, effect of depositing condition on diamond quality is experimentally examined. Moreover forming process of diamond film is observed. The synthesizing system consists of 2.45GHz microwave source, reaction chamber made of silica glass, gas supplying and evacuating systems. (100) face of silicon wafer polished with 1μm diamond is used as a substrate. By changing microwave power, methane concentration, substrate temperature, substrate dimention, reaction time and background pressure, synthesizing experiments are carried out. Nucleation density and growth rate are examined. Then diamond quality is estimated by X-ray diffraction and Raman spectra. Results obtained are as follows : In the case of using 40mm in diameter reaction tube, 8×8mm substrate is suitable. Under the condition of methane concentration 1%, gas pressure 5.3kPa, microwave power 300W and substrate temperature 860°C, well crystallized diamond similar to natural one can be obtained. Diamond film is formed through following processes, nucleation - growth of nuclei to grains - conecting grains-diamond film.

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In cutting of graphite composites which are sintered more hard and tenaciously, the characteristics of tool life are investigated from the microanalysis of tool wear and the cutting tests. Less wear of tool is observed in a harder material of tool, because a scratching by microtip causes wear to tools. The grooved wear is caused by transferring the feed mark of the machined surface to the flank of tool in cutting of some graphite composites.The exponent of Taylor's equation is about one.The differences of the exponent among workpieces are due to the change of the delay time of materials in the visco-elastic deformation, a scratching depth and the characteristics of the machined surface.

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This paper presents the experimental investigation on the vibration characteristics such as damping characteristic and equivalent mass of turning tools. The obtained results are as follows : (1) The damping characteristic is influenced by the bending stiffness of tool shank, overhang length, contact area at tool shank, and the Vickers hardness of shank materials ; (2) The equivalent mass of the tool system is influenced by the overhang length and shank cross-sectional area ; (3) The effects of these parameters on the vibration characteristics are estimated by brief empirical expressions.

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New end mills (4 flutes) with irregular tooth pitch have been proposed. These irregular end mills can reduce machining error because the instantaneous deflection of the end mills change for each cutting edge and one edge with smallest deflection can produce better surface than cutting by regular end mills. The effectiveness of 9 types of these end mills have been examined based on computer simulation, and two of them have been examined further by experimental cutting. The results obtained are as follows : maximum value of machining error is reduced by the irregular end mills. Especially the one with left helical teeth shows considerable reduction of machining error. Both of the two irregular end mills used in experiments have shown higher stability against relative vibration between the tool and the workpiece.

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Fiber reinforced plastics (FRP) has been increasingly applied in every field of camera, aerospace and vehicle industries and so on because of its light weight, chemical and corrosion resistance, electrical insulation and its high mechanical properties after all. In that line, some studies on rolling of glass-fiber reinforced plastics (GRP) thread have been done. However, the results have a lot of problems concerning accuracy of thread profile, surface finish and strength. As a new attempt, rolling of FRP thread with ultrasonic vibration is proposed in this paper. As a fundamental experiment, indentation forming of M 10 thread profile is tried by ultrasonically vibrated tool with 3 kinds of thermoplastic materials in order to confirm the possibility of rolling of plastics thread. The obtained conclusions are as followings. (1) Ultrasonic vibration is effective for indentation forming of thermoplastics and GRP. (2) For the indentation forming, an optimum amplitude of vibration exists, dependent on the physical properties of materials. (3) Consequently, rolling of FRP thread is expected to be possible.

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This paper deals with the theoretical and experimental analysis on the machining accuracy of the corner cutting and the slotting in end mill operations. The machining accuracy of a side surface is calculated by the instantaneous cutting force and the static compliances of an end mill, the tool and the workpiece holding systems in the direction normal to the machining surface. The accuracy of a bottom surface is calculated by adding the over-cutting error due to the bending deflection of the end mill to the displacements of the two holding systems in the direction of the end mill axis. The results obtained are as follows : (1) The accuracy of the machined surface can be predicted if not only the compliance of the end mill but also those of the tool and the workpiece holders are taken into consideration. (2) Up milling is recommended from the point of view of the side surface accuracy. (3) There is no significant difference in the accuracy of the bottom surface between up milling and down milling.

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A simulation criterion of wear simulation is discussed experimentally. In order to evaluate the similarity between the wear simulation model and the practical trapezoidal leadscrew, some experiments were performed on the practical screw and two types of cylindrical models which differ in the conditions of surface division. And their characteristic of wear and friction are compared and discussed. The effect of hydrodynamic lubrication can not be neglected, and, when simulation models are designed, not only all the local conditions of the simulation model must be identical with those of the practical system, but also it is important to certificate as simulation criteria that the appearance of wear debris and wearing surfaces of the simulation model are similar to those of the practical system, and that the characteristic of coefficient of friction concerned with load and speed are equivalent between the simulation model and the practical system.

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The force-deformation diagram has been used to understand the mechanical behavior of a bolted joint. There are, however, no report on the force-deformation diagram of multi-bolted joint. In this paper the author's finite element method using spring-beam elements is applied to construct the force-deformation diagram of multi-bolted joint as well as single-bolted joint. The force-deformation diagram of multi-bolted joint is expressed as the relationship between the sum of axial tension in each bolt and the expansion of a bolt. Using this diagram, not noly the relationship between axial tension and expansion of each bolt but also the relationship between compression and reaction in the contact surface produced by the lever action can be obtained for any applied load.

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Thermal displacement of the ball screw in semi-closed loop type NC machine tools directly introduces position error in the machine tool. In this paper, the thermal displacement of the ball screw is estimated by using FEM. In the estimation, data for the driving conditions of the machine tool, i.e. feed rate, slider position, and armature current of the servo motor are used as inputs. The estimated displacements of the ball screw are given to the NC in the form of pitch error compensation data. The thermal behaviour of a vertical type machining center was measured to examine the effectiveness of this compensating method. The results showed that thermal displacement of the ball screw were decreased to 15-20% while using this compensation.

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In the previous paper, a method and simulation on the nonlinear postural control of a twin cycle which has a twin wheel on its driving axis and a controlling arm suspended from the upper structure of the vehicle have been reported. This paper describes the experimental systems and results obtained with the developed twin cycle. Experiments show that the vertical posture of the vehicle can be stabilized by the two ways, one is a nonlinear control with the controlling arm, the another is a linear control with which the twin wheel exerts restoring torque on the vehicle. Furthermore, driving control of the vehicle has been attained by the cooperative use of the wheels together with the controlling arm based on the model matching method proposed in the previous paper.

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In the manual impact excitation technique, which is usually used for the measurement of structural dynamic stiffness of machine tools and other machineries, it is necessary to repeat impact excitations and average the measured data to remove the effect of disturbances. However, it is difficult to repeat the same excitations exactly because of the manual operation. Consequently, too weak impacts or multiple impacts, which result in poor signal-to-noise ratio, often occur. The present paper describes a practical measuring method in which a reference exciting force and certain permissible deviations are determined in advance and only the excitations within the permissible range are accepted. Experimental results show that the proposed method is not only useful to the improvement of measuring accuracies but also helpful to the investigation of nonlinear characteristics of the structures.

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In recent years, remarkable progress has been made in high precision machining for the production of metallic concave mirrors. However, to improve efficiency and precision in the cutting process, it is desirable to design a measurement device built into the cutting machinery and to be easy to handle. In this paper we propose a promising and practical innovation in measurement based on zone-plate interferometry. This method involves the operation of changing the curvature radius of the diffracted wave fronts by moving the zone-plate along the optical axis, and it has the merit of easy application to the measurement both spherical and aspherical mirror profiles.

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Pin-on-disk sliding test was investigated as an accelerated durability test for contact start and stop (CS/S) operations on coated magnetic recording disks. Disk lifetime and sliding characteristics of sliding test were compared with those of CS/S test. Sapphire was selected for slider material to reduce slider wear. The results are summarized as follows. (1) A good correlation is found in disk lifetime of both tests. (2) Friction force between slider and disk gradually increases at the beginning of the test, satulates at a level in the middle and increases suddenly at the end. This pattern is very similar to that of peak friction force at each contact start during CS/S test. (3) The observation through transparent sapphire slider shows that wear particle intrusion to contact point triggers the appearance of wear scar on test disk surfaces. This is also very similar to the Head Crash process during CS/S test. (4) From above results, sapphire pin sliding test considered here could be used as an accelerated durability test for CS/S operations.

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To integrate CAD and CAM systems, data for CAM system such as dimensional tolerance, geometric tolerance and surface roughness must be generated from CAD data. This sort of technical information is generally obtained in the course of detailing part specifications from assembly drawing. This study discusses a method of automatic determination of part specification for a rotational functional units of machines such as spindle head or gear box. The determination of technical information for machining is based on the assembly data model which consists of fit and contact relations among parts. The method of dimensional tolerancing along shaft axis proposed is formulated not to violate the clamping function which is realized by bolts and nuts. It is formulated as a set of rules which extracts the loops of connective relations and sets dimensional tolerance. The rule to set radial tolerance, geometric tolerance and surface roughness from connective relations and part function is also described. An experimental prolog program, which automatically generates tolerance information by using the rules mentioned above, proved itself to work properly through examples.

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One design procedure for precision positioning mechanisms with closed-loop control is described. A calculation formula is given for estimating a positioning accuracy when the mechanism can be regarded as a simple vibration system with one degree of freedom. Influence of each parameter upon the positioning error is discussed. Furthermore, influence of each parameter upon the positioning time is investigated by using a computer simulation technique. Considering of these results, one design procedure for achieving a least positioning time property on condition that the specified positioning accuracy is satisfied.

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This paper presents a method to calculate the dispersion of production efficiency in automatic assembling lines. The method is based upon considerations for the fundamental element and the proper sampling time on the line proposed previously. The paper purposes to be informed a measure of dispersion in the production efficiency by days. Main results reported in this paper are as follows : (1) Relative frequencies calculated by the method take good agreements of simulated ones. (2) Dispersion increases with the cycle time of the line in the same running time. (3) Dispersion is influenced by the ratio of the recovery time at troubles and the intermediate buffuer volume.

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