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Volume 16 (1982 - 198･･･
- Issue 32 Pages 1-
- Issue 31 Pages 1-
Volume 16, Issue 31
Displaying 1-5 of 5 articles from this issue
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Explication of Wire VibrationKenichiro HORIO, Natsuo KINOSHITA, Masahiko FUKUI1982 Volume 16 Issue 31 Pages 1-13
Published: September 30, 1982
Released on J-STAGE: March 12, 2010
JOURNAL FREE ACCESSGeneral characteristic of wire vibration and the relationship between wire vibration and periodic discharge concentration in wire E. D. M. were investigated in the first report. In this report, more detail discussion of wire vibration in working gap were investigated.
Following things are found. Periodic discharge concentration occurs a little earlier than wire comes close to workpiece, so it is estimated that bounding force caused by discharge concentration makes wire go away from workpiece. The existence of front gap, that means there exists workpiece in front of working direction, effects both forced vibration and free vibration. It causes forced vibration and extinction of normal mode vibration. Longer a point of wire apart from working gap, smaller the effect forced vibration at that point becomes and shorter the amplitude becomes.
Wire vibration is expressed by the same formula as forced vibration of chord. And the component corresponding to free vibration never varies even if machining conditions are altered. The potential of forced vibration change not by alternation of vibrating directions and machining conditions but only by the distance from working gap.View full abstractDownload PDF (6619K) -
Yoshitsugu MUKOYAMA, Isao OGATA, Masahiko HIHARA1982 Volume 16 Issue 31 Pages 14-24
Published: September 30, 1982
Released on J-STAGE: March 12, 2010
JOURNAL FREE ACCESSElectric discharge cutting by using an electolytic working fluid (silicic acid soda) has become to be applied widely for special or particular metal and products machining. This method is better economy than mechanical cutting methods, and the demand has an increasing every year as the progress of development for special or particular materials. But there are many problems to be solved in the point of improvement the cutting characteristics and security of cutting surface quality.
In this paper, the residual stress on working surface, hardness in the affected zone and working characteristics such as working (cutting) speed, wear rate of electrode and etc. were examined experimentaly in the electric discharge cutting by the belt-shaped tool electrode.
As a result, it became clear that the residual stress and the affected zone by thermal action were mainly affected by working current and running speed of tool electrode, working (cutting) speed was influenced considerably to working current, density of working fluid and tool electrode running speed, and generally wear rate of electrode was inclined conversely to the tendency of working (cutting) speed, etc.View full abstractDownload PDF (4561K) -
Optimum Control of Die Sinking EDMMasakazu KISHI, Yasuo SUZUKI, Atsushi OOMORI1982 Volume 16 Issue 31 Pages 25-34
Published: September 30, 1982
Released on J-STAGE: March 12, 2010
JOURNAL FREE ACCESSThe method of optimum control has been investigated for the first step of a development of EDM automatic system. An aim of this optimum control is to obtain the maximum metal removal rate.
The effective pulse efficiency was used as index performance of EDM process. A good correlation between the metal removal rate and effective pulse efficiency has been verified experimentally under the constant pulse duration and peak discharge current.
The control parameters are (1) working voltage (servo referance voltage), (2) pulse duty factor, (3) electrode lifting cycle time, (4) dielectric pressure. An algorithm for controling four parameters was determined by experimental design method using the table of arthogonal arrays.
The optimum control using established algorithm achieves more metal removal rate than manual operation by a skillfull operator.View full abstractDownload PDF (728K) -
Tamio TAKAWASHI, Kazuhiko KOBAYASHI, Haruhiko ITO, Toshimitsu SAKAKIBA ...1982 Volume 16 Issue 31 Pages 35-45
Published: September 30, 1982
Released on J-STAGE: March 12, 2010
JOURNAL FREE ACCESSThis study covers the mirror surface machining by planetary electro discharge machining (EDM). In the process of this EDM, a mirror surface is created in a micro-energy condition where an independent pulse circuit is used, and its gloss is affected by the electrode polarity, storage capacitance, discharging energy and planetary motion.
It has been found as the result of our three-dimensional analysis of a single discharge crater by using a scanning electron microscope and contouring device that the mirror surfacing depends upon the profile of the discharge crater. Also the gloss can be effectively calibrated by the analysis in which the laser diffraction is adopted.
Our study on mirror surfacing by EDM has made clear the following:
(1) In micro-energy conditions using independent pulse circuit where any storage capacitance is eliminated, an extremely flat discharge crater with smaller undulation is obtained when the electrode is negative.
(2) The mirror surface is realized by both the microscopically smooth surface formed by such flat discharge craters as overlapped, and the macroscopic smoothing adopting the elimination of undulation by means of planetary motion.
(3) The gloss of mirror surface has no relation whether or not the workpiece has been subject to heat treatment, but depends upon the small cracks occurring because of the carbide or stressed condition of machined surface due to the composition of material.
(4) The gloss of mirror surface is affected by the capacitance formed between electrodes; as the machining area increase, the gloss will be degraded, and the surface will change from mirror to dull surface.View full abstractDownload PDF (7184K) -
[in Japanese]1982 Volume 16 Issue 31 Pages 46-49
Published: September 30, 1982
Released on J-STAGE: March 12, 2010
JOURNAL FREE ACCESSDownload PDF (346K)
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