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Volume 44, Issue 528
Displaying 1-19 of 19 articles from this issue
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[in Japanese], [in Japanese]1978 Volume 44 Issue 528 Pages 1418-1423
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDownload PDF (807K) -
Yongseong LEE, Kazuyuki HIRAMOTO, Toshio SATA1978 Volume 44 Issue 528 Pages 1424-1430
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSTemperature distribution on the flank face and rake face of a cutting tool is analyzed by using a finite element method developed in this study. The method enables one to compute the steady-state temperature distribution in both the workpiece material and cutting tool without repetition of computation. Experiments are carried out to verify the validity of the developed method by using a thermoelectric junction imbedded in a tool. Good agreement is obtained between the analytical results and the experimental ones for the temperatrue distributions on both the flank face and rake face of a cutting tool. The analytical results show that the temperature on the top flank face of a tool is higher than that on the top rake face of the tool because of the difference of the friction velocity on each face of the tool. The experimental results also show good correspondence with this analytical prediction.View full abstractDownload PDF (924K) -
Study on Buffer Storage in Production Line Systems (4th Report)Kenjiro OKAMURA, Hajime YAMASHINA1978 Volume 44 Issue 528 Pages 1431-1437
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThis paper investigates the role of buffer storage capacity in the unbalanced production line where cycle times vary from stage to stage, by analyzing the effects of degree of unbalance and buffer storage capacity on the production rate and the mean number of units in the storage area. It is shown that if buffer installation, is not possible, the line should be designed to have the same cycle times over all stages. When buffer installation is possible, the line should be designed in such a way that the stage production rates are the same by being unbalanced deliberately if the characteristics of breakdown and repair of the stages are not identical. The improvement of production rate by the provision of a buffer can be expected in this case. Due to technical considerations, if the line cannot be designed such that the stage production rates are almost the same, then it is unlikely that the installation of a buffer will be justified.View full abstractDownload PDF (833K) -
Mamoru IDO, Yoshio TANAKA, Kunihiro TANAKA1978 Volume 44 Issue 528 Pages 1438-1444
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSCharacteristics were studied about the generation of surface shapes in a reciprocation lapping by combining different kinds of workpieces as the lower and the upper ones. New properties were found from the simulations and experiments as well as a fact that the fundamental characteristics obtained in a previous paper by combining same kinds of workpieces are preserved. That is, the parabolic shapes of the surfaces are maintained during lapping, and in the change of profile parallel to the reciprocation, (1) the upper and the lower workpieces become concave and convex respectively as lapping proceeds (the generalized property inherent to lapping method) and (2) they tend to fit each other (the generalized property relating to the interaction of the surface forms of the upper and the lower workpieces). The process how to fit is newly known to be different depending upon the stock removal ratio between the lower and the upper workpieces. However only the second property is observed in the change of profile perpendicular to the reciprocation. Linear vector differential equations are introduced to represent universally the above characteristics in the space which is constructed by a rectilinear coordinate system instead of the orthogonal coordinate one used in the previous paper.View full abstractDownload PDF (844K) -
Kiyoshi ITAO, Koichiro ISHIKAWA1978 Volume 44 Issue 528 Pages 1445-1451
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThis paper treats with a design method of wire matrix print heads adopted to a lot of present data terminals, and describes the development of a Kanji printer. A free-flight wire mechanism has been introduced for the purpose of high-speed printing, untroublesome operation, easy maintenance, and self-compensation of the wire length against the wear. The investigation of fine wire printing conditions results in the high-quality matrix printing technology equal to full stroke printing in the use of smallest wires in diameter (0.2 mm) as well as the invention of a print wire arrangement. The wire diameter is fattened abruptly to 0.5 mm at the half of the longitudinal way in order to minimize the transmission loss of the printing energy. High-speed drive of the print wires has been performed by means of the reduced weight of wires and armatures, and of trapezoidal magnet-core invention. On the basis of the above-mentioned fundamental technologies, a Kanji printing mechanism has been developed and the proposed design method has been confirmed.View full abstractDownload PDF (1100K) -
Kazunobu SATO, Yoshimi TAKEUCHI, Nobuyuki OKUBO, Toshio SATA1978 Volume 44 Issue 528 Pages 1452-1456
Published: December 05, 1978
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThe way of evaluating the strength of heat sources within mechanical structure quantitatively has not been found out when one analyses the thermal deformation of a machine tool structure or considers its prevention. This paper deals with the method to estimate the strength of heat sources and the temperatute distribution of the machine tool easily and accurately only on measurement of the temperature at heat sources or around them by the use of the finite element method. This method is applicable to the case of the presence of several heat sources and not only to the steady state but also to the non-steady state. In this paper we introduce the principle of this method to identify the strength of heat sources, explain the computer program developed on the basis of it and show the results to have confirmed the validity and accuracy of the method experimentally. Moreover the method could be applied to identify the strength of heat sources in regard to some kinds of machine tools with good results.View full abstractDownload PDF (725K) -
Masataka NAKAGOME, Masao MIZUNO1978 Volume 44 Issue 528 Pages 1457-1463
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSIn this report, the effects of initial stress on the fatigue strength of roller chains are investigated experimentally and theoretically. The results are as follows :
(1) The effects of initial stress on the fatigue strength of roller chains depended on the change of internal stress caused by press-fit of bushings and compressive residual stress arose by prestress, the improvements of the fatigue limits for constant mean stress could be estimated theoretically.
(2) The fatigue limits of roller-link-plates with the finishing of the press-expansion at the holes increased more than the fatigue limits of roller-link-plates without the finishing of the press-expansion at the holes.
(3) The fatigue limits of roller-link-plates with the press-fit of bushings, and pre-load, after the finishing of the press-expansion at the holes increased more than the fatigue limits of roller-link-plates with the press-fit of bushings, and pre-load, without the finishing of the press-expansion at the holes.View full abstractDownload PDF (999K) -
Grinding Process with Partially Bevelled WheelToshikatsu NAKAJIMA, Yoshiyuki UNO, Toyohiko MORIKAWA1978 Volume 44 Issue 528 Pages 1464-1469
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSA new technique is proposed for improving efficiency without detriment to quality in traverse grinding. The traverse grinding process with a conventional wheel is first experimentally analysed to make it clear that the grinding action of wheel varies widely in different positions on the wheel surface along wheel width, and that the whole surface of wheel is not always effective in the traverse grinding. Then a new traverse grinding technique with the partially bevelled wheel on the leading part of acting surface is proposed to improve the conventional method. The technique leads to the extension of metal removing part of wheel and the decrease of the effective cutting depth of grains, and therefore by increasing cutting depth of wheel, high grinding efficiency can be attained without detriment to surface finish. The wheel wear also remarkably decreases in the technique.View full abstractDownload PDF (996K) -
The Role of Inclusion on Fracture Phenomena in Separation ProcessToshiaki KANEEDA, Hideo TSUWA1978 Volume 44 Issue 528 Pages 1470-1475
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSSurface generation mechanism in metal cutting is composed of two processes. They are separation process at tool tip and burnishing process at clearance face, the former is deeply concerned with surface finish. Therefore, it is very important to analyse the separation process microscopically. In this report, first, the effect of inclusions which initiate ductile fracture on fracture phenomena in the separation process is experimentally investigated. Furthermore, the effect of metallurgical factors such as grain boundary and the second phase, and machining factor such as depth of cut and rake angle are also analysed. The results show that there exist fracture phenomena even in the separation process of continuous chip formation in fine cutting of the ductile materials such as aluminum, low carbon steel, pure iron and armco iron. Inclusions contained in work materials cause micro and macro cracks which propagate along the maximum shear stress direction. The surface finish is damaged by fracture phenomena of various types depending on the relative position of the inclusions to that of the cutting tip.View full abstractDownload PDF (1216K) -
On the Tool MaterialsTsuyoshi ASAI, Seiji NAKATANI, Akio HARA1978 Volume 44 Issue 528 Pages 1476-1481
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSIn previous reports, the early fracture of P 20 carbide tools during the interrupted turning of steel was investigated in order to determine the influence of the tool/work engagement and disengagement conditions, the non-cutting time/cutting time ratio and the work materials upon the early fracture. The results were discussed using the “cutting speed-feed rate diagram, ” and the “mean normal and shearing stress on the rake face-cutting temperature diagram” under steady state conditions. This paper further describes some experiments on the interrupted turning of steel in order to determine the characteristics of the early fracture peculiar to tool materials. The conclusions are as follows.
(1) The experimental early fracture criteria of P 10, P 20, P 30 and TiC cermet tools were clarified using the cutting speed (V) - feed rate (F) diagram and the mean normal stress (σ) on the rake versus cutting temperature (T) diagram under the steady state condition.
(2) The early fracture resistance of the cemented carbides were better than those of the TiC cermets in the higher temperature-higher pressure region, but conversely were worse than those of the TiC cermets in the lower temperature-lower pressure region where the tool/chip welding-fracture occurs easily.View full abstractDownload PDF (896K) -
Analysis by the Strain Incremental TheorySadakatsu FUCHIZAWA, Hisao TAKEYAMA1978 Volume 44 Issue 528 Pages 1482-1488
Published: December 05, 1978
Released on J-STAGE: February 15, 2010
JOURNAL FREE ACCESSThis paper deals with the analysis by the strain incremental theory for the deformation of thin-walled cylinder of finite length subjected to hydrostatic internal pressure and axial load, and also deals with the comparison between the results of this analysis and the previous ones due to the logarithmic total strain theory. It is assumed that the material of the cylinder is isotropic and rigid-plastic and obeys the power law of strain hardening. The Levy-Mises stress-strain relations and von Mises' yield condition are used. Stress and strain distribution, relation between the internal pressure and the center radius, maximum internal pressure, critical expanding radius, etc. are obtained in relation to length/diameter ratio, L/D, strain hardening exponent, axial load, existence of die, etc. It becomes evident that the results of the analysis by both theories show good agreement for long cylinders (L/D _??_2-3), but when the cylinder is short (L/D_??_2-3) discrepancy appears because the stress ratio considerably changes as the deformation of the cylinder develops. Therefore, it is desirable to apply the strain incremental theory to analyze the deformation of the short cylinders.View full abstractDownload PDF (895K) -
Investigation of the Effect of Workpiece RotationTetsuo MATSUO, Hiromichi ODA1978 Volume 44 Issue 528 Pages 1489-1494
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe most important subject in cutting operation is to increase cutting efficiency, and also, to decrease cutting cost. Recently, the abrasive cut-off operation with workpiece rotation has attracted special interest as a high efficiency cutting method. However, there are many points which are uncertain. In the present study, the wheel performance and economics of the abrasive cut-off operation, in which a high speed rotating abrasive wheel is plunged at the constant speed into a rotating workpiece, have been described. The 28 mm dia. S 45 C and SUS 304 steels were used for the workpiece. And, its rotating speed was 0, 40, 100, 200, and 320 rpm. The 260 mm dia. rubber wheel, which is rotated at a speed of 5, 000 rpm, is plunged into the workpiece at the speeds of 3.0 to 56 mm/min. It was found from this experiment that the remarkable reductions in cutting time and cost are realized by the rotation of workpiece. The duration of wheel was also extended, specially when cutting the S 45 C steel. Further, no defects on the cut surface, such as burr or burn, were observed when the rotation was applied.View full abstractDownload PDF (792K) -
Flow Stress under Variable Temperature and Variable Strain RateKatsuhiro MAEKAWA, Takahiro SHIRAKASHI, Eiji USUI1978 Volume 44 Issue 528 Pages 1495-1500
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe flow stress of 0.15% C-steel at temperatures 20-800°C and strain rate 200-2000 s-1 is measured with the split Hopkinson pressure bar technique. The results are summarized as follows :
(1) Under variable temperature and strain rate, the flow stress σ depends upon not only strain ε, temperature θ, and strain rate ε, but also the histories of the temperature and the strain rate to which the steel has been subjected during straining.
(2) An empirical expression of the flow stress including the history effects, but not including anneal softening and age hardening effects, is given as,
σ=σ0 (θ, ε) e-Kθεm (∫θ, ε≡h (ε) ek/nθε-m/ndε) n
where K, m, n are constants, σ0 (θ, ε) is a function of temperature and strain rate, and the integral part is assigned for the history effects.
(3) Increase of the flow stress due to the blue brittle phenomenon is not memorized in the steel and thus it does not concern with the history effects.
(4) Two different methods in evaluating the history effects are derived from Lagrangian and Eulerian points of view respectively. The methods are proved to yield the same empirical expression of the flow stress.View full abstractDownload PDF (936K) -
Yoshio SAITO, Yoshimi ITO, Nobuhiko NISHIWAKI, Kenjiro YAMAMOTO1978 Volume 44 Issue 528 Pages 1501-1507
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSIn grinding process, the rotation of the wheel influences the flow of the air and/or grinding fluid around the wheel and the workpiece. The thermal boundary condition of the workpiece surface, e. g. the heat transfer coefficient, which is one of the important factors to analyze the thermal deformation of a workpiece concerning the grinding accuracy has a close relationship with the flow behaviour. Moreover, to design the rational grinding fluid application. system it is of importance to make clear the flow pattern around the wheel. Here, experiments have been carried out with a surface grinding machine to examine the flow velocity of air around the grinding wheel by changing its porosity. In addition, the permeability of the grinding wheel, which plays the main role in the flow around a porous media such as a grinding wheel, is measured and the relationship between the permeability and the flow velocity is also considered. On the basis of the results obtained from the experiments, it is clear that the permeability has a remarkable influence on the flow pattern around the grinding wheel. Consequently, it may be said that there exists a flow of air which flows through the grinding wheel and blows out from its periphery.View full abstractDownload PDF (1460K) -
Isamu YOSHIMOTO, Kazuo MARUYAMA, Kaoru HONGO, Tsutomu SASAKI1978 Volume 44 Issue 528 Pages 1508-1513
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSAs the screw threads profile to improve the fatigue strength, ISO high fatigue resistance screw threads profile has been proposed. This profile is as follows : nut threads have ISO general purpose screw threads profile, and bolt threads have the flank angle modification of +5°in the pressure flank and the pitch modification of -0.15%. This paper deals with the theoretical and experimental analyses on the screw threads profiles to improve the fatigue strength, taking ' account of the above ISO proposal. The obtained conclusions are as follows : (1) From the analysis by the finite element method it is found that the improvement of fatigue strength of screw threads is expected by the pitch modification, but not by the flank angle modification. (2) From the fatigue experiments with the bolts 10 mm in nominal diameter and 12. 9 in strength grade, it is found that the pitch modification shows a significant effect on the improvement of the fatigue strength, while the flank angle modification does not.View full abstractDownload PDF (848K) -
Comparison with Various Manufacturing MethodsIwao HAYASHI1978 Volume 44 Issue 528 Pages 1514-1519
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe vibration with tooth separation of gears, which are made by the various manufacturing methods, is measured. And the vibration is studied with the help of the expressing method, by which the transmission error is expressed in the shape of vectors drawn by using the amplitude and the phase angle of each component of the Fourier Series of the error curve. The followings are obtained. 1) An amplitude of the vibration is greatly influenced by the higher harmonics of the transmission error even in the range, in which the meshing frequency is much lower than the natural frequency of the pair of the gears. Therefore it is necessary to remove the higher harmonics in order to decrease the amplitude of the vibration. 2) The relation between the vibration and the manufacturing methods is as following. The hobbed gears, whose transmission error has many large higher harmonics, have the large vibration. The gears finished by grinding, shaving and horning, whose transmission error has few small higher harmonics, have the small vibration. This result coincides with the above item 1).View full abstractDownload PDF (1140K) -
[in Japanese], [in Japanese], [in Japanese], [in Japanese]1978 Volume 44 Issue 528 Pages 1520-1522
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDownload PDF (450K) -
[in Japanese]1978 Volume 44 Issue 528 Pages 1523-1528
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDownload PDF (1024K) -
[in Japanese], [in Japanese], [in Japanese], [in Japanese]1978 Volume 44 Issue 528 Pages 1529-1533
Published: December 05, 1978
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDownload PDF (906K)
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