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Volume 35, Issue 417
Displaying 1-12 of 12 articles from this issue
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[in Japanese]1969 Volume 35 Issue 417 Pages 609-623
Published: 1969
Released on J-STAGE: February 16, 2010
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Hiroshi FURUICHI, Noboru TAKAHASHI1969 Volume 35 Issue 417 Pages 624-628
Published: 1969
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSDislocation arrangement of a weared or a super-finished surface in α-brass has been observed using an etch pit method.
The main results are as follows : -
(1) The density of dislocations varies from crystal to crystal and from matrix to twin in a weared or super-finished surface.
In some places no dislocation etch pit could be observed in spite of the fact that scratches were observed everywhere on the surface.
(2) The bands of dislocation etch pits were observed on a weared or a super-finished surface, where scratches were observed all over the surface.
These (1) and (2) may indicate that friction consists of softening, and shearing fracture after sticking or ploughing, respectively.
(3) Sometimes, cracks which started from non-metallic inclusion were observed.
(4) Grain boundary migration was observed on super-finished specimens.View full abstractDownload PDF (1808K) -
Hidehiko TAKEYAMA, Kaneyoshi MIYASAKA1969 Volume 35 Issue 417 Pages 629-633
Published: 1969
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSSo-called grooving wear at an end cutting edge is not only extremely detrimental to the quality of machined surface, but also hazardous for the quality control of surface finish. The experimental investigation has revealed that surface roughness reaches a peak at a rather initial stage of cut and then falls down to level off as the relative width of grooving wear does. This fact has led a new technique, in which the feed rate is continuously varied during machining to average out the distribution of grooving wear. By utilizing this technique the level of surface roughness can be maintained lower and more stationary for a long cutting time.View full abstractDownload PDF (724K) -
The Effects of Surface Roughness and Annealing on StrengthMitsuhiko FURUKAWA, Kazuki OGAWA, Tadaaki SUGITA1969 Volume 35 Issue 417 Pages 634-642
Published: 1969
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThis study was attempted to determine the effects of the annealing treatment and of the surface roughness on bending rupture strength of the sintered alumina. The specimens were fabricated by hot pressing. Hot pressing of 99. 5% Al2O3, 0.5% MgO was carried out at the temperature range from 1400 to 1500°C for 1 hour. The results obtained in this work are as follows.
(1) The bending rupture strength for the ground specimen is markedly reduced by surface flaws produced with surface finishing. This unfavourable damage, however, disappears with annealing at higher temperature than 1000°C.
(2) When the specimen is annealed, the scattering of the strength becomes smaller than that of the unannealed specimen. The scattering of the strength begins to reduce from annealing temperature of 1000°C in the case of 1 hour annealing for ground specimen.
(3) By the annealing treatment the geometry of grinding marking and other surface micro flaws are considerably changed. Grinding flaws begin to become smooth by annealing at 900°C for 1 hour and they disappear by annealing at 1500°C for 1 hour. The grain shape begins to be changed at 1200°C. However the large drop of the strength does not occur even after the annealing at 1500°C where grain grouth is slightly observed.View full abstractDownload PDF (3657K) -
Takao KAYABA, Chuichiro SUZUKI, Yukio NOGUCHI1969 Volume 35 Issue 417 Pages 643-648
Published: 1969
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSIn this paper, the radial movements of the pressed cages of deep groove single row radial ball bearings were examined by the optical locus of cage center, and the relations between the amplitude of the movements of center and the various conditions with some lubricants were derived.
Then the following conclusions were drawn :
(1) Under the usual lubricating conditions, the forces acted impulsively between the balls and the cage with the rise in revolution. Therefore, the recorded figure became of ruggedness. Especially it has been observed that the movements of cages were influenced by the vibration of balls in the direction of cage rotation on the shaft speed of 40005000 rpm.
(2) The viscosity of lubricants, or their temperature characteristics, affected very much to the amplitude of cage center.
(3) Under the thrust load, the radial movements of the cage center were very small.View full abstractDownload PDF (1068K) -
Genrokuro NISHIMURA, Motoyoshi HISAOKA1969 Volume 35 Issue 417 Pages 649-655
Published: 1969
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSConcerning the machining mechanism of ultrasonic mechanical machining, the theory of stationary vibration of an elastic bar is studied for the case when the bar is collided with a rigid body supported by the action of static pressure to obtain the displacement U of the tip of the bar facing the rigid body. The theory, moreover, gives the impulsive force Ft=t1 induced at the instant when the bar collides with the rigid body. Investigating the characteristics of U and Ft=t1, it is ascertained that the theoretical dispositions of these quantities are reasonable and well-founded by the experimental results obtained when the stationary ultrasonic vibration of collision between the tool of mild steel and the work of glass plate is performed by using an apparatus of ultrasonic mechanical machining of frequency of 21.5 kc/s.
Further, under the acceptable conception that the action of the displacement U is the root of the pumping action of the ultrasonic mechanical machining and that of the impulsive force Ft=t1 causes the hammering action of it, the theoretical characteristic of the product of U and Ft=t1 is studied to obtain the theoretical matters favourable for certain to explain the experimental fact concerning the characteristics of the machining rate of the ultrasonic mechanical machining which has a special response to the variation of the static pressure.View full abstractDownload PDF (1083K) -
1969 Volume 35 Issue 417 Pages 655
Published: 1969
Released on J-STAGE: June 30, 2009
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Velocity Relief Angle and Flank WearSUSUMU KASEI, Toshio HARA, Masahiro MASUDA1969 Volume 35 Issue 417 Pages 656-661
Published: 1969
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThis paper deals with the rotary cutting tool wear and the velocity relief angle which is defined in this paper as the modified relief angle given by the inclination of tool face. The cutting operation with the rotary cutting tool is almost impossible when the velocity relief angle is zero. This is called the limit of the cutting. This paper also discussed the available limit of tool shape and the cutting conditions, and examined the domain of practical use.
Flank wear of the tool was discussed from the point of geometrical view, and the pattern of the tool wear was confirmed experimentally by the SUMP method (resin replica method) and the tool-maker's microscope.
The results obtained are as follows.
1) Larger tool diameter, work diameter and relief angle, and smaller tool inclination angle, depth of cut and feed tend to make the zone wider in which the cutting operation can be perf ormed.
2) Flank wear of the rotary tool advances with a curvature at the cutting edge.
3) Flank wear of the rotary tool is extremely less than that of the conventional tool, and is hardly affected by the inclination angle of the rotary tool.View full abstractDownload PDF (885K) -
Hiroyuki YOSHIKAWA1969 Volume 35 Issue 417 Pages 662-667
Published: 1969
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSIn finishing or machining process of crystals, mechanical behavior of the crystals is an important factor that affects the surface texture generated.
In the present paper, the effects of size of stressed part upon mechanical behavior of the part of crystal surface in the process of finishing is investigated theoretically. The sizes are classified into four categories each of which is characterized by the lattice defects existing, that is, dislocations and cracks. Investigation upon the operating predominance of lattice defects for each category revealed the distinction in mechanical behaviors of crystals of each category, when impressed by an indenter. In the crystal of very small size where no dislocation and no crack exists, indentation of tool upon crystal surface gives rise to the generation of dislocation first prior to brittle fracture. In the crystal with only dislocations, where it was revealed that the analysis by the elastic-plastic theory is essential, plastic deformation occurs first, some amount of which allows cracks to nucleate in the deformation zone and to extend into elastic zone giving rise to macroscopic brittle fracture. The forming mechanism of plastically deformed zone around indentation, and size-dependent brittle-ductile transition mechanism are explained. Those studies have made it possible to predict the behaviors of various crystals in finishing process, and to establish some general rules for the selection of finishing method which is optimal for the surface property required.View full abstractDownload PDF (875K) -
Takashi OKAMOTO, Shohei OGAWA, Fumihide KIMURA, Takehiko KUDO1969 Volume 35 Issue 417 Pages 668-674
Published: 1969
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSIn the present paper, the results of basic experiments conducted on ultrasonic vibration shaving is described, as a mean of obtaining the smooth surface.
As first step, the cutting mechanism in vibration shaving was investigated, then the shaving was performed by running a cutter in meshing with a work gear supplied the ultrasonic vibration. After shaving, accuracy of gear, surface roughness of gear tooth and noise in running were measured, then these results were compared with those in case of ordinary method.
These results when summarized are as follows.
(1) The cutting direction of shaving cutter on the tooth surface and the rake angle of cutting edge in cutting vary in every moment. And there is the period when tooth surface is not cut, which changes in compliance with the position of tooth surface and the vibration conditions.
(2) The roughness of tooth surface finished by vibration shaving becomes smoother than that by ordinary shaving, therefore the extent of decrease in the noise in running compared with that before shaving is larger than that in the ordinary method.
(3) The accuracy of gear is improved by shaving, but there is no significant difference between ultrasonic vibration shaving and ordinary shaving.View full abstractDownload PDF (1081K) -
[in Japanese]1969 Volume 35 Issue 417 Pages 675-677
Published: 1969
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDownload PDF (505K) -
[in Japanese]1969 Volume 35 Issue 417 Pages 678-684
Published: 1969
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDownload PDF (774K)
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