In order to establish the most suitable method of design of threaded joints used in ultrasonic vibration system, the effects of the threaded joints on vibrational characteristics of the ultrasonic vibration system are investigated by comparing the test piece of threaded type with that of solid type which is regarded as an ideal of threaded type experimentally and theoretically. In this report the case where threaded joints are located at the node of stress amplitude, is treated. The obtained results are as follows: (1) Concerning Q value of ultrasonic vibration system, Q value of threadedtype is about 70% of that of solid type. (2) Concerning resonant frequency of the system, by solving the fundamental equation of longitudinal vibration of the test pieces of threaded type and solid type, the frequency equations are deduced. Then the results from the frequency equations are similar in tendency to that from the experiment. (3) Concerning displacement amplitude of the system, the mode of displacement distribution obtained from the experiment approximately agree with the tendency of that obtained theoretically. Also it is scarecely dependent on tightening force of the threaded joints.

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Factors generating microscopic residual shear stress τ_ZXW in uni-directionally machined layers produced by cutting and grinding were studied experimentally. In the affected layers, residual strain distributions depend on machining direction and the strains are generated by τ_ZXW. In affected layers, generally, macroscopic residual stresses are thought to consist of three elements resulting from thermal, burnishing or rubbing and mechanical cutting action of a cutting tooth and abrasive grains during machining process. Relations between the three elements and τ_ZXW were also investigated experimentally and the following can be summarized.τ_ZXWis extinguished in process ofrecovery dueto heating at low temperature in furnace. τ_ZXW produced by cutting and grinding increases as carbon content of steel increases, but has a tendency to be saturated in carbon segregated regions. These results show that τ_ZXW is a phase stress generated by elastic recovery force of cementite acting upon slip plane of ferrite grains. On the other hand, the travelling heat source at high temperature decreasesτ_ZXW and generates microscopic residualstress.τ_ZXW generated in pearlite structure is greaterthan one in spheroidal cementite structure. The factors of generating τ_ZXW are mechanical cutting and burnishing action, microstructures of steel and machining conditions.

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The purpose of this study is to establish an efficient method for designing and building microcomputer control system which can be used by small enterprises in applying numerical control to special purpose mechanical equipments typically transfer machines. By carrying out a number of development project, management method and development support tools suitable for the purpose have been devised. This developed methodology is characterized by the following features: (1) The target system is to be structured by a number of standardmodules which can proceed through the development phases individually and if required simultaneously by different personnel groups. (2) The control hardware and the control software can go through the design, build and debug phases in parallel to improve work efficiency. (3) In order to avoid duplications and errors in the development phase, project management is carried out using standardized documents.

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This paper describes the measurement methods of the guideway errors and the relation between the guideway errors and the accuracy of coordinate measurement of 3-D measuring machine. The main items obtained in this paper are as follows: (1) The error of the probe position is expressed in terms of the guideway errors. (2) Coordinate measurement error can be large even if there are relatively small errors in the guideway accuracy. (3) The measurement method of rolling error of X and Y axis is made by using an autocollimator and mirrors. (4) The rolling error has a most serious influence for accuracy of coordinate measurement by 3-D measuring machine.

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A design method of the cylindrical linear induction motor (abbr. C-LIM) is mentioned in this paper. An analysis method of electromagnetic characteristics of the C-LIM is developed by the onedimensional linear current model. In the case of 2 phase 2 coils C-LIM, it is difficult to use the railway LIM analysis method because its ratio of slot width/core width is different from the C-LIM's. And performing experiments about actual motors, frequency-force characteristics are obtained respect to some values of secondary surface resistivity. From these studies following results are obtained:(1) From the analysis model, flux distribution and sliding force expressions are derived by dividing input current distributions into 4 regions. (2) The equivalent magnetic gap for a slider-stator gap is estimated using the finite element method and equivalent electric circuit. (3) Difference between calculation values and experimental values of frequency-force characteristics is about 10%. (4) It is shown that the maximum starting force is obtained from the suitable polepitch, secondary surface resistivity, frequency, and equivalent magnetic gap, and C-LIM can be designed as a servomotor by taking those suitable motor parameters for the maximum starting force.

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When machining a workpiece supported between two centers, the centers and the center holes act as rotational guideways. Accurate motion of the workpiece is guaranteed only under the condition that both of the centers and the holes are aligned coaxially. Some alignment errors, however, may be induced by machining errors of the holes and mounting errors of the centers and may deteriorate the rotation accuracy of the workpiece. In this report, the kinematic behavior of the workpiece is investigated in the case where true cone-shapedcenters and holes which are out of alignment make contact near the edge of the holes. The obtained results are as follows: (1) The alignment error between centers alone does not affect the rotation accuracy of the workpiece. (2) The alignment error between center holes causes a sinusoidal radial displacement of one cycle per revolution of the workpiece. (3) The alignment error between centers and that between holes jointly cause sinusoidal radial and axial displacements of one cycle per revolution of the workpiece. (4) The amplitudes of these sinusoidal displacements increase in proportion to the center hole diameter in the case of a fixed alignment error.

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Probabiristic and statistical unique phenomenon is discussed, which can be observed on the combining process of goods in mass by a goods combining machine. The phenomenon is related to the relationship between the combination efficiency and number of pieces of goods combined. It is therefore considered as a kind of "Synergy". In this paper, from the standpoint of positive and negative synergy effects, the phenomenon is discussed based on the computer simulations and the equations derived for the consideration. As the result, the mechanism which produces the positive and negative synergy effects is made clear.

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Cutting-off of structural steel is investigated experimentally with the alloy tool steel circular saw at speeds from 4500m/min to 7 200m/min in order to ascertain how machinability at high speeds differs from that at the conventional speeds in terms of cutting resistance, depth of cut, specific cutting resistance and cutting temperature, and thereby to provide basic data for more productive methods of fine cutting-off at high speeds. So as to ensure accurate experiments, the crosssection of the workpiece being cut is prepared such as the mean engage angle of the tool and the number of simultaneous cutting blades are kept invariable. The main conclusions are as follows: (1) The optimum mean engage angle exists to maximize the depth of cut. (2) The feed and depth of cut are in proportion to the feed force per blade, regardless of the number of simultaneous cutting blades. (3) With the increase in the cutting speed, the depth of cut and cutting efficiency increase, whereas there is no remarkable increase in the cutting resistance, specific cutting resistance and cutting temperature. (4) The hardness of the workpiece has similar effects on machinability in the high speed cutting as in the conventional range of speeds. It follows from the above that increasing the cutting speed provides an effective method for high efficiency cutting.

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Recently, the de velopment of new materials belonging to hard machinable one has been increasing. In this situation a combined method of mechanical, electro-discharge and electro-chemical machining becomes attractive. It is called combined machining here. This type of grinding wheel which was made by electroless plating of Nickel (Ni) on a conventional WA wheel was investigated. The plated wheel has the same capability as a conventional grinding wheel and it is possible to change the ratio of usual mechanical removal action to electro-chemical romoval action with this wheel. In this paper, an experimental analysis to get the condition of making a combined machining wheel is presented. The main factors which influence onelectroless Ni plating were classified into 7 levels and studied by means of experimental analysis based on factorial design through 64 kinds of different plating conditions. The influence of the factors and their mutual effects were obtained and represented as a regressive equation. The influence of the amount of plating, composition of plating bath and circumstances of heat treatment on hardness (Hv) of plated film was investigated. As the results it is known that film hardness reaches up to 1100 Hv after heat treatment at 400°C in air or in vacuum with the bath composite NaH₂PO₃ 20g/ l and NiSO₄ 40g/l. Through grinding test, it was clarified that the amount of plating and machining conditions changed the machining characteristics such as grinding force, electric current, electric current efficiency and removal rate.

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