Journal of The Japan Society of Electrical Machining Engineers
Online ISSN : 1881-0888
Print ISSN : 0387-754X
ISSN-L : 0387-754X
Volume 4, Issue 8
Displaying 1-7 of 7 articles from this issue
  • [in Japanese]
    1971 Volume 4 Issue 8 Pages 1-13
    Published: March 31, 1971
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
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  • [in Japanese], [in Japanese]
    1971 Volume 4 Issue 8 Pages 14-28
    Published: March 31, 1971
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
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  • Mikio MOTOKI, Ichiro FUJITA
    1971 Volume 4 Issue 8 Pages 29-34
    Published: March 31, 1971
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    The E. D. F. has been recently developed to metal working which i s one of the high-energy-rate forming processes and this technique is industrially putting into practice.
    This paper deals with some propositions on E. D. F. in oposition to the usual E. D. F. with twin rod electrode.
    (1) An E. D. F. of single electrode type is characterized by that a work metal to be deformed is used as one of electrodes, resulted in simplification of a forming apparatus and a electrode composition.
    (2) An E. D. F. of multi-electrode type has successfully developed for the purpose of plastic deformation of large metalic plate in the same manner as explosive forming.
    (3) On the other hand, it is possible to deform a work metal by using water hammering of high-speed and high-pressure water jet which is spouted out from an orifice of the vessel, in which an impulsive high current discharge is generated.
    These methods proposed by the authors have many merits it comparison with the conventional E. D. F. process.
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  • Takahisa MASUZAWA, Toshio SATA
    1971 Volume 4 Issue 8 Pages 35-43
    Published: March 31, 1971
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    This paper shows a new type source for EDM The mechanism of its circuit and some results of experiments about the source are discussed.
    The circuit produces a series of current pulses without any pulse generator or energy storing element, and has many superiorities to general transistor-switching-or RC-circuit, as follows.
    1) The shape of produced pulses is originally uniform.
    2) The pause time between each pulse can easily be shortened to less than 0.5μs. Then, the frequency of discharge can be over 1Mc/s.
    3) when short or semi-short circuit occurs, main current is instantly decreased nearly to zero. (Ideal for wirecutting machines.)
    4) As the circuit itself is a sort of generator, it is far simpler than conventional transistor circuit. So, it can be made compact, for example, 100mm×50mm×50mm.
    This new source gave the removal rate of 22mg/min when the surface roughness was 2.0μRz. This proves the high quality of this circuit.
    The principle can be applied to medium or rough range of EDM.
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  • Shigeo ZAIMA, Yukio TAKAHASHI, Susumu KAMO
    1971 Volume 4 Issue 8 Pages 44-51
    Published: March 31, 1971
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    Some experiments on electrolytic grinding of a hypersilumin which showed very poor machinability in respect of tool wear are carried out with a sodium nitrate solution as electrolyte and a trial electrolytic grinding wheel for the purpose of examining the applicability of electrolytic grinding on the alloy.
    As the results, the applicability of electrolytic grinding on the alloy is superior and there are optimum electrolytic grinding conditions, i. e. current density, grinding pressure, grinding speed, electrolyte flow rate and others, in which the grinding removal rate is effective and the ground surface is better than that obtained by mechanical grinding, The structure and the heat treatment of the alloy show no great influences on the optimum electrolytic grinding conditions.
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  • Yoshitsugu MUKOYAMA, Minoru ARAI
    1971 Volume 4 Issue 8 Pages 52-62
    Published: March 31, 1971
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    On electric discharge machining, the worked surface receive the higher heating action in extremely short time, a part of electrode are vaporized, the other are melted, but it is difficult to be removed the whole of the molten part by discharge pressure. Any molten part remain as melting remnant zone under which heat affected zone is formed, and educed carbide, material of the opposite electrode are sticked on the dischage crater. Those zone afford the influerce on the machining characteristics.
    This paper shows mainly the measured result of melting remnant zone and heat affected zone on worked surface.
    1) Those Zones gradually increase as the discharge energy is increased, and the discharge duration has special effects upon the product of zone, The above mentioned phenomena varries due to the working fluid and working electrode materials.
    2) The thickness of the melting and heat affected zone resulting from the heat influence of repeating discharge is decreased, as compared with the single discharge.
    3) The maximum quantity of melting remnant is about 70% of total molten material. For increasing the removal efficiency, it is necessary to produce effective discharge pressure, when the quantity of the molten material is great.
    4) Shape of melting remnant may affect to repeating discharge stability.
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  • [in Japanese], [in Japanese]
    1971 Volume 4 Issue 8 Pages 63-68
    Published: March 31, 1971
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
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