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Volume 36, Issue 431
Displaying 1-11 of 11 articles from this issue
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[in Japanese], [in Japanese]1970 Volume 36 Issue 431 Pages 783-789
Published: December 05, 1970
Released on J-STAGE: July 23, 2009
JOURNAL FREE ACCESSDownload PDF (9278K) -
Nobuyuki OHTA, Hirokazu KAWANAKA1970 Volume 36 Issue 431 Pages 790-795
Published: December 05, 1970
Released on J-STAGE: January 20, 2010
JOURNAL FREE ACCESSThe discharge coefficient of the gate from which the flow of a molten metal is injected into the cavity of dies is very necessary, in order to design the dies used for die casting. In this research, the apparent discharge coefficient of the gate is investigated experimentally on following three ways which are often recognized in die casting dies.
1. flowed along a wall of cavity,
2. injected on flat or cylindrical core,
3. changed the direction of a flow in cavity of dies.
As the result, these coefficient are generally smaller than that in the case injected without interruption in atomosphere. Also these coefficient are changed according to the shape of a cavity and the thickness of a gate. Therefore the more complex the shape of cavity is and the thicker the gate is, the smaller this coefficient is.View full abstractDownload PDF (2188K) -
Shiro IZUMI, Masato SAKATA, Hironobu MITSUDA1970 Volume 36 Issue 431 Pages 796-802
Published: December 05, 1970
Released on J-STAGE: January 20, 2010
JOURNAL FREE ACCESSThis is the third report succeeding the fomer two, which were about the mathematical analysis of the behaviour of metal plate under the lateral impact. This report resumes and puts in order, the development and the results of the experiments carried out for several years for the orientation of the problem, to pursue the research. Every effort have been made to relate as precisely as possible the main subject of it in order. It is advocated that there is a good reason to regard especially lead (Pb) as the representative of the general metallic material, as far as the impact deformation is concerned. Therefore, the tension-strain relation S= K(1+ε) can be regarded as the base of motion of metal plate under lateral impact, because the results of the experiments agree in their profil form well with those of the theory which has been previousely constructed upon the same assumption. This is the present report, and after this, the more strict research has been carried out by considering ε-wave more precisely. In that case, the relation S=K(1+ε) becomes the 1st approximation formula. These will be reported next.View full abstractDownload PDF (6681K) -
The Residual Stresses in the Steel Balls (1st Report)Motohisa HISHIKI, Kikuo MATSUURA, Toshiki HORI1970 Volume 36 Issue 431 Pages 803-807
Published: December 05, 1970
Released on J-STAGE: July 23, 2009
JOURNAL FREE ACCESSThe fatigue of the steel balls is influenced by the residual stresses. The purpose of this paper is to research the behavior of the residual stresses in the steel balls heat-treated at various conditions. The stresses are measured by X-ray diffraction.
The results obtained are summarized as follows:
1.The residual stresses do not always increase, even though the quenching temperature is raised. As a result there exists a quenching temperature in which the residual stresses are at the maximum.
2. As the tempering temperature is raised, the residual stresses after quenching decease.
3. The residual stresses change little by the tempering time.
4. The residual stresses in the steel balls quenched in oil are smaller than those quen-ched in water.
5. Subzero treatment has no influence upon the residual stresses.
All measured residual stresses in the steel balls are found to be compressive stresses which are useful for the fatigue life.View full abstractDownload PDF (4085K) -
Trapping Behaviour of Lubricant during Compressive Deformation of Metals (2nd Report)Mitsugu TOKIZAWA1970 Volume 36 Issue 431 Pages 808-813
Published: December 05, 1970
Released on J-STAGE: July 23, 2009
JOURNAL FREE ACCESSOn the basis of the study made in the deformation process with respect to the behaviours of friction and lubrication and also the micro-structure of metals, a new lubrication system has been proposed here. The behaviour of the metal can be observed by means of the light-etching method on the pre-deformed metal surface. The action of retained lubricants in the metal-tool-interface is due to the hydrostatic effect in the microscopic surface pockets of a work piece which are all formed due to several types of mechanism.
In type 1 where metal as aluminium, it resulted from asperities in different orientation of grains and the slip-band.
In type 2 where brass and carbon steel as metal, it resulted from the hollow pit between the convexed second phase (e.g, β-phase or pearlite) and the slip-band.
In type 3 where bearing steel as metal, it resulted from asperities to be associated with the different orientation of grains and also from the micro-cavities between carbides which are all dispersed finely and uniformly.
The low coefficient of friction which was observed in a smaller grain size seems to be from the fact that, a large amount of pit-space occupied by the surface pockets were finely continued with the fine slip-band in these pockets.View full abstractDownload PDF (8816K) -
On the Fracture of Abrasives in Blasting (2nd Report)Shiro YAMADA, Kunio YANAGISHIMA1970 Volume 36 Issue 431 Pages 814-819
Published: December 05, 1970
Released on J-STAGE: January 20, 2010
JOURNAL FREE ACCESSIn this paper, abrasives of Aluminum oxide and Silicon carbide (mean grain diam. :116 μ) are blasted both in dry method and wet method at the same speed (the speed is about 150 m/s measured at the middle point between a nozzle and a work material along the nozzle centerline). Other conditoins are the same as in the 1st report. It is investigated that the fracture of abrasives in wet blasting is influenced by the presence of water, the change of blasting angle and three kinds of work materials i.e. mild steel (SPC-1), silicon steel (S 10 F) and aluminum (A1P3-1/2 H). The experimental results obtained are as follows :
1) In perpendicular blast, a case of the hydrophilic abrasives (A). The damping action by water is canceled with the promoted action of the fracture of abrasives by the presence of water as atomosphere. But the hydrophobic abrasives (C) do not show this kind of action, and the fracture of abrasives decrease by the damping action of water.
2) The decrement of blasting angle causes the increase of the duration of action by the presence of water, therefore the fracture of abrasives is more influenced by the promoted action of water than the damping action by water, because the hydrophilic abrasives (A) in wet blasting are more friable than in dry blasting.
3) The friability of the abrasives used in this experiment increases with an increment of the hardness of work materials.View full abstractDownload PDF (3681K) -
Ryonosuke NARUTAKI, Toshimichi MORIWAKI1970 Volume 36 Issue 431 Pages 820-825
Published: December 05, 1970
Released on J-STAGE: January 20, 2010
JOURNAL FREE ACCESSThe goose-neck tool, which has been empirically used to prevent chatter vibration during parting operations etc. on a lathe, is analyzed from the view point of transfer function, and its effectiveness against chatter is theoretically shown. The analysis suggests necessity of large damping to increase effectiveness, and a method is presented to determine optimum spring constant and damping to be given. A damped goose-neck tool due to oil viscosity was manufactured and some cutting experiments were performed to show the validity of the analyses. From these tests, it was shown that the stable cutting width increased as the spring constant was decreased, however larger damping had to be given accordingly. The damped goose-neck tool was also proved to be effective at comparatively high cutting speeds, say 80 m/min in this test.View full abstractDownload PDF (1032K) -
Kazuo NAKAYAMA1970 Volume 36 Issue 431 Pages 826-833
Published: December 05, 1970
Released on J-STAGE: July 23, 2009
JOURNAL FREE ACCESSSince metals are elastic-plastic body, some amount of elastic deformation around the plasti-cally deforming region is unavoidable in any mechanical process of metal transformation like plastic forming processes, cutting, grinding, lapping, etc. This local elastic deformation in workpiece togather with that in tool causes the geometrical discrepancy between the tool and the finished surface.
In this paper, theoretical and experimental studies on the local elastic deformation in grinding reveal that the elastic deflection at the grain-work contact
1. increases when (a) the hardness of work material is high, (b) the moduli of elasticity of work and tool materials are low, (c) the tip of grain is dull, and (d) the width of groove made by the grain is wide,
2. gives the appearance as if the individual grains on a grinding wheel are supported by non-linear springs,
3. decreases the actual depth of cut, (more than 1 μm of size error is attributed to this deflection in usual grinding of hardened HSS.) and
4. makes the ground surface of hard material smoother than that expected from wheel surface geometry.
Compared with this deflection, the deflection of grain due to the vitrified bond elasticity which was suggested by R.S. Hahn is negligible.View full abstractDownload PDF (3591K) -
[in Japanese], [in Japanese], [in Japanese]1970 Volume 36 Issue 431 Pages 834-838
Published: December 05, 1970
Released on J-STAGE: July 23, 2009
JOURNAL FREE ACCESSDownload PDF (718K) -
[in Japanese]1970 Volume 36 Issue 431 Pages 839-844
Published: December 05, 1970
Released on J-STAGE: January 20, 2010
JOURNAL FREE ACCESSDownload PDF (1251K) -
1970 Volume 36 Issue 431 Pages 845-847
Published: December 05, 1970
Released on J-STAGE: July 23, 2009
JOURNAL FREE ACCESSDownload PDF (564K)
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