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Volume 34, Issue 402
Displaying 1-8 of 8 articles from this issue
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Itaru KAWAGUCHI, Ryo NAGATA, Genjiro OKUNO1968 Volume 34 Issue 402 Pages 454-460
Published: July 05, 1968
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA test apparatus by which the resistance of free rolling between ball and plane can be measured was arranged.
By a preliminary experiment using this apparatus, following results are found.
(1) The measured rolling resistance includes two components, i. e., the one is caused by fluctuation of the gravity potential and the other is a component of pure rolling friction.
(2) The former component stated above can be guessed from measured vertical displacement of the upper specimen plate.
(3) “Decrements” of the pure rolling friction were examined for some steps of the normal load. Here, the term “decrement” is defined tentatively by the decreased magnitu : le of the pure rolling friction in the first five reciprocal rollings at a position of specimen under a constant normal load. Consequently, it is found as a rough tendency that the “decrement” decreases with increare of the normal load up to a certain critical value, and at the critical load the decrement once becomes large suddenly, then it decreases gradually with increase of the normal load.
(4) The pure rolling friction takes a small but not negligible value even at the lowest normal load imposed in this experiment, and its increment for increase of the normal load becomes large discontinuously at the critical normal load stated above.
On the basis of the above results, discussions are made with respect to some problems which should be studied more precisely.View full abstractDownload PDF (2821K) -
Ryoji MURATA1968 Volume 34 Issue 402 Pages 461-466
Published: July 05, 1968
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThis paper describes the principle, the design and the application of the newly developed device for measuring dynamic stiffness.
The device mainly consists of electro-dynamic shaker (7 kg-wt nominal force; 40 kg-wt bias force; 2mm stroke), point-contact driving head with two symmetrical piezo-electric pick-ups, fixtures, rigit table (500 mm×800mm size ; 350 kg weight) and electronic circuits.
The symmetrical pick-ups are capable of mesuring the force applied on a driving point of the object up to 1.0kc/s with sufficient accuracy (±4 %).
Simultaneous measurement of the acceleration of the driving head, which is approximately equal to that of the driving point, renders simple measurement of the dynamic stiffness.
However, if the dynamic stiffness of the object is above 1011 CGS, the effect of contact stiffness cannot be neglected. In this case, the third pick-up (acceleration sensor) is needed for a corrected measurement of the contact point. The mass of the third pick-up can be compensated electrically.
Some example of the measurements of dynamic stiffness are shown in comparison with the theoretically estimated values.
The device is also applicable for measurements of frequency response of cutting tool dynamometers.View full abstractDownload PDF (2545K) -
Takeshi YANAGISAWA, Kijuro NAKAMURA, Tuneo HIKICHI1968 Volume 34 Issue 402 Pages 467-472
Published: July 05, 1968
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe sound of a reed-organ, harmonica and accordion has been believed to be made by the surface of a vibrating reed tongue and by the surface of a sound board vibrating from reaction of the tongue vibration. This paper denies this and asserts the following,
(1) In the above instruments there is a difference in air pressure with a slot as a boarder, and a very rapid flow of air through the slot. When the tongue closes and opens the slot periodically, the sound is produced by changes in air pressure around the slot.
(2) The vibration of the soundboard is also produced by the change in air pressure, but the sound produced by vibration of the soundboad is very weak.View full abstractDownload PDF (6003K) -
Effect of Lubricating Oil on Wear of Metals (3rd Report)Kiyokazu OGAWA, Eiichi TAKEUCHI1968 Volume 34 Issue 402 Pages 473-477
Published: July 05, 1968
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThis report describes a study on effect of lead stearate on wear of metals in sliding under lubrication.
Firstly, effect of added quantities of lead stearate on coefficient of boundary friction and oil film strength was investigated. From the result, critical quantity for added lead stearate which made these values uniform was acquired to be 0.2%
Secondly, pressure-wear and velocity-wear characteristic curves were investigated in using lubricating oil. From the result, it was obtained that the contact pressure at stabilized limit of wear mechanism was 50kg/cm2 at the oil temperature of 20°C and 3.40m/s in sliding velocity and that this is 30kg/cm2 at the temperature of 50°C. The pressure values were higher than that by simple base oil. Lead stearate at oil temperature of 50°C was found to effect the most effective action on wear. Also, nearly the same tendenicy was obtained in wear of long distance. In summary, it was found that lead stearate had excellent lubricating facilities in the field of mild wear.View full abstractDownload PDF (1058K) -
Keiji OKUSHIMA, Tetsutaro HOSHI, Norihiko NARUTAKI1968 Volume 34 Issue 402 Pages 478-483
Published: July 05, 1968
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSMachining of Ca-Si deoxidized, Fe-Si deoxidized and conventionally deoxidized steels was investigated in order to reveal the effect and mechanism of the tool-surface layer consisting of oxides and sulfides in preventing the tool wear. The tool-surface layers were surveyed by the e!ectron probe X-ray microanalyzer, and the structural components of the laver were identified in this study.
The following conclusions were obtained : When machining Ca-Si deoxidized or Fe-Si deoxidized steels, the oxides and sulfides form layers on the tool surface, which avoid the direct contact of the work iron with the tool carbides, thus prevent the diffusiaa of the tool material.
When cutting Ca-Si deoxidized steels, semitransparent layer forms preferably on carbide tools which contain TiC, and it consists of 2 to 3CaO·Al2O3·SiO2. In case of Fe-Si deoxidized steels, ashy-grey coloured layer forms preferably on ceramic tools and it consists of CaO, Al2O3, SiO2 and MnS.View full abstractDownload PDF (7654K) -
Surface Properties of Electrolytically Ground Cemented Carbide (I)Eiichi SUGANUMA1968 Volume 34 Issue 402 Pages 484-490
Published: July 05, 1968
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSElectrochemical behaviour of cemented carbide electrode has been experimentally investigated. In this paper some result of experiments are presented with poarization curves of cemented carbide in aqueous solution of potassium and sodium nitrate and anodic process of the materials is discussed. The data were checked by means of potentiostatic method and chemical analysis. Surfaces of the electrode were examined by electron microscopy of replica. The main results obtained are summarized as follows :
1) Characteristic curves of the current-potential in aqueous solution of KNO3 and NaNO3 show the same features. There are four (WC-Co alloy) or five (WC-TiC-Co alloy) distinct stages in the curves according to the anodic reactions.
2) In the first stage, it takes place of the dissolution of cobalt in the diralent state as prored by potassium nitrite reaction and deformation of carbide component is observed (the fourth stage) after gas evolution from the solution (the third stage).
3) The second stage is a passive stage which indicated by a measurable drop in current. In this stage, current changes exponentially with respect to the time. This may suggest that cobalt oxides are formed on the electrode.
4) In the ash grey precipitate of WC-TiC-Co alloy, Ti4+ is detected by hydrogen peroxide reaction. Curve with two maxima for the alloy are obtained and the second maximum (the fifth stage) depend on a rate of potential increasing. The electrode surface is covered with precipitation in the stage.View full abstractDownload PDF (6813K) -
[in Japanese]1968 Volume 34 Issue 402 Pages 491-499
Published: July 05, 1968
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESS -
[in Japanese], [in Japanese]1968 Volume 34 Issue 402 Pages 500-506
Published: July 05, 1968
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDownload PDF (1082K)
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