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Volume 12 (1978 - 197･･･
- Issue 24 Pages 1-
- Issue 23 Pages 1-
Volume 12, Issue 24
Displaying 1-4 of 4 articles from this issue
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[in Japanese], [in Japanese]1979 Volume 12 Issue 24 Pages 1-23
Published: March 31, 1979
Released on J-STAGE: March 12, 2010
JOURNAL FREE ACCESSDownload PDF (1220K) -
Method for measuring of the precusory phenomena of wire breakingMasahiko FUKUI, Natsuo KINOSHITA, Kanemasa OKUDA1979 Volume 12 Issue 24 Pages 24-36
Published: March 31, 1979
Released on J-STAGE: March 12, 2010
JOURNAL FREE ACCESSThis paper deals with the precusory phenomena of the wire breaking in wire EDM and the effective method for foreseeing the wire breaking.
We found that the waveform of gap voltage and the frequency of discharge changed before the wire breaking.
The precusory phenomena of wire breaking are as follows;
1) The precusory phenomena appeared about 40ms before wire breaking. At this time, the frequency of discharge was measured three or four times as meny as the mean value in the normal EDM process. Moreover, during the about 10ms before wire breaking, discharge concentrated abnormally and the maximum frequency of discharge reached 77 pulse/ms.
2) Considering the relation between the wear of wire electrode and the frequency of discharge, we investigated the cause of wire breaking. In all probability, wire breaking occured when discharge concentrated abnormally at comparativelly small space.
According to these results, the wire breaking can be foreseen and avoided.View full abstractDownload PDF (1847K) -
Takeshi YATOMI, Kazuhiko KOBAYASHI, Yutaka TANAKA, Yoshio OZAKI1979 Volume 12 Issue 24 Pages 37-51
Published: March 31, 1979
Released on J-STAGE: March 12, 2010
JOURNAL FREE ACCESSThis paper deals with the fundamental problem and the solution on the machining of the workpiece with variable work thickness in the Wire Cutting EDM.
So far, in this kind of machining, there have been such problems that the machining feed rate is not only slower, but also the machining accuracy is worse as a result of the constant electrical condition of the power supply. Therefore, the optimum control has been developed, which exchanges automatically the electrical conditions according to the change of the work thickness by detecting that change during machining, and is compared with the usual machining methods of the constant electrical condition.
Consequently, the machining characteristics such as machining feedrate, machining accuracy was found to be remarkably improved by the optimum control.View full abstractDownload PDF (1160K) -
Machining Accuracy by a stepped-Cylindrical Tool ElectrodeHachiro TSUCHIYA, Tomoichi INOUE, Masami OMORI, Makoto MIYAZAKI1979 Volume 12 Issue 24 Pages 52-60
Published: March 31, 1979
Released on J-STAGE: March 12, 2010
JOURNAL FREE ACCESSThe paper deals with the performance of the cylindrical electrode having an annular step (the stepped tool electrode) which is formed behind full sized end of the elctrode to prevent side discharge in E. D. M. of cylindrical blind hole.
In comparison with the results by the cylindrical hollow electrode, previously reported, the following results are obtained in a series of experiments in which the stepped tool electrodes are used under no forced fluid flow.
1) Lower removal rates are observed while smaller electrode wear rates are obtained.
2) The machining accuracy in terms of the working gap and the form error of the hole machined is improved in the use of the stepped. The roundness of the hole and the flatness of its bottom are kept at the same level as those obtained previously.
3) The depth of the step is recommened to be more than 0.5mm. The recommended length of the full sized end portion of the stepped electrode depends on working depth.View full abstractDownload PDF (2590K)
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