[in Japanese]

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In the former reports the lite and the final failure of the carbide tool in the machining, without any chatter and with chatter due to the deflection of a flexible tool, are examined experimentally.
Accordingly the experiment is made on the effects of chatter due to the deflection of a main spindle of a lathe and a workpiece on the life of the carbide tools, and this paper examines these results by comparison with the results of the former reports.
It is consequently ascertained that the final failures of the carbide tools in this machining differ completely from those in the machining with chatter of a tool having large amplitude, and these beararemarkable resemlance those in the machining with chatter of a tool having large amplitude, and these bear a remar kable resemlance those in the machining with chatter of a tool having small amplitude and without any chatter of a tool or a workpiece. Also the wear on the toolflank in the machining with chatter of a workpiece makes slow progress in comparison withthe wear in the machining with chatter of a tool. Furthermore in the machining with bothchatters of a tool and a workpiece all tool faces flake off, and, are short-lived.

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When a solid body is going to slide on a vibrating surface being in contact with, the static friction appears to reduce.
In the present report, the effects of the vibration which reduce the apparent coefficient of static friction are discussed on three directions of vibration, in X, Yand Z axes, where X axis isthe sliding direction andZ the vertical to the sliding surface.
The apparent coefficients of static friction effected by vibration in these directions, μ
_x', μ_y' μ_z'are given following expressions respectively, μ_x'=μ_sΛ_√1+μ_s²-Λ²/1-Λ², μ_y' =√μ_s²-Λ²/1+Λ², μ_z'= μ_s (1-Λ√1+μ_s²-μ_s² Λ²) /1-μ_s²Λ²
where μ_s is the true coefficient of static friction and Λ=aω²/g is the ratio of acceralations.
These theoretical results have been also confirmed by experimental studies.
Further, from these results it is shown that μ_x'< μ_y', μ_x'< μ_z' in general and the vibration acting in sliding direction, X axis, is most effective to reduce the apparent coefficient of static friction.

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The angular distributions of reflected light from specular and indecent metal-surfaces finished by diamond cutting tools are measured by an automatic recording goniophotometer. The results are compared with the diffraction theory of optical gratings with triangular grooves with two flat faces, and the difference is discussed in connection with irregularity of the side faces of grooves on the surfaces.
On both sides of the grooves on iridescent surfaces, there are many fine streaks parallel to the grooves which seem to be caused by unevenness of cutting edges of diamond tools. On other hand, the cutting edges of tools for specular surfaces are flat, and the distribution curves of reflected light correspond to the results calculated with diffraction theory fairly well.

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An electrnic instrument was developed to measure kinematic accuracy of a main spindle on a machine tool. Runout of the spindle is detected without contacting the surface of the spindle by means of inductive differential transformers which are placed around the spindle in each 90 degrees. Signals detected comprises those of spindle vibration and those of eccentricity of spindle surface. The instrument can subtract the eccentricity out of the signal detected so that actual behavior of the spindle, can be observed on the CRT. The pick-ups are held in a solid block and have a broad linear sensitivity along the movement of ±0.25mm. Axial float of the spindle may be checked as well.
The maximum magnification of the instrument is 10, 000. Overall accuracy of measurement is 0.2μ. The frequency charactcristics is flat within ±0.5 db over 0 to 1300 c/s. Errors and deviations in angular velocity of the spindle may be checked by means of the bright and dark spots on the CRT with the accuracy of ±1%.

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