Journal of The Japan Society of Electrical Machining Engineers
Online ISSN : 1881-0888
Print ISSN : 0387-754X
ISSN-L : 0387-754X
Volume 1, Issue 2
Displaying 1-5 of 5 articles from this issue
  • [in Japanese]
    1968 Volume 1 Issue 2 Pages 1-24
    Published: March 31, 1968
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
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  • KIYOSHI INOUE, MAKOTO ONOUE
    1968 Volume 1 Issue 2 Pages 25-42
    Published: March 31, 1968
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    THE CONTENTS OF THIS PAPER DESCRIBED BASIC PHENOMENA OF ELECTRICAL DISCHARGE FORMING AND ITS APPLICATION.
    DISCHARGE PHENOMENA, IN LIQUID SUCH AS OIL, NATER, ETC. ARE ANALIZED, AND IT IS DESCRIBED THAT THE PRESSURE PEAK VALUE OF SHOCK WAVE TO BE CE GERATED, IS PROPORTIONAL TO ROOT OF THE CHARGING ENERGY (1/2CV2), AND ITS EFFECTIVE PEAK PRESSURE ACTUALLY APPLIED, IS ON AND AROUND 1000kg/cm2 AT 10 KJ.
    IN ADDITION TO THE ABOVE, GENERAL FEATURES OF SHEET METAL FORMING BY DISCHARGE ARE ILLUSTRATED, TOGETHER WITH PRODUCTIVE ELECTRICAL DISCHARGE FORMING MACHINE AND ITS ACTUAL SAMPLES.
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  • [in Japanese], [in Japanese], [in Japanese]
    1968 Volume 1 Issue 2 Pages 43-50
    Published: March 31, 1968
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
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  • Experimental study with high frequency power generator
    Hisao KURAFUJI, Yoshitsugu MUKOYAMA
    1968 Volume 1 Issue 2 Pages 51-70
    Published: March 31, 1968
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    A high frequency power generator was used in these experiment, and it was confirmed that even when the repetition of discharges is comparatively quicker (3500 time/s approx.), the discharge machining phenomena can be analogized from a single electric discharge.
    Then, a discharge machining circuit of the voltage doubling system was manufactured for trial, and with a small power (5kVA), a comparatively large removal rate (W=14g/min and Hmax=75-80μ) and a satisfactory electrode wear ratio of unprecedented 0.1-1.0% were obtained.
    By using this discharge machining circuit, it has become possible to use with good results the material of the aluminum group, which were previously considered unfit for the tool electrode in spite of their excellent malleability workability, structural strength and cconomy.
    The electrode wear ratio factor by drilling electrode also has been improved by about 70-80%.
    Further, favourable conditions for the stability of electric discharge are found by studying the phenomena of the stability of electric discharge from the phenomena of turbidity of the working fluid for discharge machining and by investigating effect of metal grains, etc.
    In that working fluid, and thus discharge machining has become possible under conditions where it was previously thought difficult to conduct discharge machining.
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  • Black Layer of Electrode Surface
    Shigeshi NISHIMURA, Masamitsu TSUCHIYA
    1968 Volume 1 Issue 2 Pages 71-79
    Published: March 31, 1968
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    It is generally considered that the composition of black layer on the tool electrode surface is the principal factor of low electrode-wear electrical discharge machining.
    This paper reports the relation between the ratio of electrode-wear and the black layer, and also the results of quantitative analysis about iron and carbon contained in this layer.
    The experimental results and discussions are as follows:
    1) Under such machining condition that forms the black layer, the electrode-wear becomes very low.
    2) The thickness of this layer is proportional to the discharge energy.
    3) The black layer mainly consists of iron and carbon, and the volume of them are nearly equal.
    4) The wear of this layer is very small compared to the wear of electrode metal.
    5) In the case of single pulse discharge, a blacking are formed around the discharge crater of tool electrode. The black layer is thought as the accumulation of them.
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