Journal of The Japan Society of Electrical Machining Engineers
Online ISSN : 1881-0888
Print ISSN : 0387-754X
ISSN-L : 0387-754X
Volume 31, Issue 66
Displaying 1-3 of 3 articles from this issue
  • Hisashi YAMADA, Naotake MOHRI, Katsushi FURUTANI, Nagao SAITO, Takuji ...
    1997 Volume 31 Issue 66 Pages 1-7
    Published: March 31, 1997
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    In wire electrical discharge machining (wire-EDM), it is very important to restrain the vibrations of a tool wire electrode for the improvement of machining accuracy. In this paper, we analyze the measured displacement of a wire electrode in the machining process for a thin plate with normal vibration modes. The fundamental characteristics of the vibration system are investigated through statistical analysis. 1st mode displacement behavior which is simulated under the external force caused by electrical discharge is compared with measured displacement.
    The force in real machining depends on the direction of the wire movement in vibration. The phase difference between the external force and the displacement is extremely important for the restraint of the wire vibration.
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  • Shin-ichiro KUBOTA, Yoshiyuki UNO, Yasunori MATSUMOTO
    1997 Volume 31 Issue 66 Pages 8-17
    Published: March 31, 1997
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    YAG laser has actively been used for precision micro machining, since it has become possible to get stable and high quality beam and the spot diameter can be focused less than 100 micrometers. High energy beam machining with YAG laser or CO2 laser is heat energy machinig accompanied with heating, fusion, evaporation processes, therefore the adhesions of spatter and dross to base material lead to the deterioration of machining integrity. In this paper, the dross generation mechanism in precision micro cutting of thin plate with pulsed YAG laser is experimentally investigated.
    Main conclusions obtained are as follows:
    (1) In a single pulse machining, the spatter scatters on the base material surface at irradiation side and the dross sticks around the hole at exit side.
    (2) Oxygen assist gas makes the mobility of melting material increase, which leads to the decrease of the adhesion of dross.
    (3) The height of dross is greatly affected by the beam overlap rate, and it takes maximum when the beam overlap rate is about 93%.
    (4) The dropout phenomenon of dross is occurred when the beam overlap rate is more than 96%.
    (5) The generation of dross is restrained by shortening the gap distance between the nozzle of assist gas and the workpiece.
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  • Zuyuan YU, Takahisa MASUZAWA, Masatoshi FUJINO
    1997 Volume 31 Issue 66 Pages 18-24
    Published: March 31, 1997
    Released on J-STAGE: March 12, 2010
    JOURNAL FREE ACCESS
    In this paper, we present 3D micro-EDM with electrodes having simple square cross section. In order to maintain the original electrode shape, the machining conditions are set so that the bottom of the electrode is properly worn. The influence on the precision of the machined surface is analyzed by changing machining conditions such as tool path and number of cutting steps. Furthermore, the formula for tool wear compensation in 3D micro-EDM has been derived. As a result, square cavities with sharp corners could by machined. Inclined planes could also be machined by applying the compensation equation.
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