Journal of The Japan Society of Electrical Machining Engineers
Online ISSN : 1881-0888
Print ISSN : 0387-754X
ISSN-L : 0387-754X
Volume 34, Issue 77
Displaying 1-5 of 5 articles from this issue
  • Makoto YOSHIDA
    2000 Volume 34 Issue 77 Pages 1-7
    Published: November 25, 2000
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
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  • Hideki HAGINO, Shuichi NOGUCHI, Kiyonori MASUI
    2000 Volume 34 Issue 77 Pages 8-14
    Published: November 25, 2000
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    This paper describes the technical merits of CO2 laser welding of titanium using a simple shielding system. The results of CO2 laser welding for titanium plates showed that excellent mechanical properties were obtained without after-shielding. From the thermal analysis during the laser welding process, it was determined that the temperature of both the welding zone and the heat-affected zone rose rapidly and then fell rapidly. Thus, atmospheric contamination (i. e, oxidation and nitriding) during laser welding was less than that during TIG (tungsten inert gas) arc welding.
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  • Improvement of Off-Time Control Method for Small Radius Concave Corner R
    Haruki OBARA, Tsuyoshi OHSUMI, Wataru IMAI, Yoshinori YAMAGISHI, Masat ...
    2000 Volume 34 Issue 77 Pages 15-21
    Published: November 25, 2000
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    This paper describes a control method to improve the accuracy of a concave corner with small radius R on the rough cut of wire EDM. A well-known off-time (pulse interval time) control method has an advantage in terms of corner precision but it takes a long time to cut the corner. In this paper, methods to reduce the machining time of the off-time control method are discussed. The off-time control method is combined with the overcut method, the servo voltage control method and the simple path modification method. The proposed method is found to be useful for improving the corner accuracy and reducing the machining time. The machining time was decreased from 90 to 28 seconds, and it was shorter than 34 seconds of the dwell over cut method proposed in a previous study. The residual error of the corner shape was decreased to 15μm. The procedure and expressions used to calculate the control values are described.
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  • Masahiro NAKASE, Haruki OBARA, Tsuyoshi OHSUMI, Masatoshi HATANO
    2000 Volume 34 Issue 77 Pages 22-29
    Published: November 25, 2000
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    In this study, the explosive load acting on the wire surface generated by discharge on the rough cut and the finish cut of wire EDM is investigated. The hydrodynamic explosion process in the water-filled gap is numerically analyzed using adiabatic bubble expansion model, and the impulsive load of each discharge acting on the wire surface is calculated. The distribution function of the discharge number on the wire surface is derived and the total load acting on the wire generated by continuous discharges is estimated. Wire deflection caused by the total load is compared with the experimentally obtained wire deflection and also with the wire deflection derived from the simple model, assuming that the impulsive load of each discharge is constant and acts normally on the wire surface. Results show that; 1) the impulsive load vector on the wire surface of each discharge is not normal to the wire surface, 2) the value of impulsive load by each discharge depends on the slammed depth and the location on the wire surface and 3) the results of analysis are able to explain the influence of the skimmed depth on the wire deflection of the finish cut and the rough cut.
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  • Shoju AOSHIMA
    2000 Volume 34 Issue 77 Pages 30-35
    Published: November 25, 2000
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    Download PDF (8439K)
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