All issues
Volume 18 (1984 - 198･･･
- Issue 36 Pages 1-
- Issue 35 Pages 1-
Volume 18, Issue 35
Displaying 1-7 of 7 articles from this issue
- |<
- <
- 1
- >
- >|
-
Basic Research on Contour MachiningTsutomu KANEKO, Masamitsu TSUCHIYA1984 Volume 18 Issue 35 Pages 1-14
Published: September 30, 1984
Released on J-STAGE: March 12, 2010
JOURNAL FREE ACCESSIn the three-dimensionally controlled electro-discharge machining (EDM), it is important to develop machining programs which compensate the electrode wear in machining processes. In these programs, it is generally considered effective to divide a whole machining process into some characteristic steps and to adapt a suitable compensating method in each step.
On the basis of above consideration, some experiments are performed about one of the methods which is a combination of a rough machining step with large blocks in higher depth of cut (for brevity, “large block machining”) and a fine contour machining step with remaining small blocks (for brevity, “small block machining”). And suitable compensating methods of these steps are investigated. From the results, the following conclusions are mainly obtained.
1) In the large block machining, it is effective to compensate the cutting length of electrode at the time when this electrode length has worn out.
2) In the small block machining, it is necessary to compensate both the wear of electrode length and of electrode radius.
3) It is possible to obtain a practical machined surface by using the above compensating method and by giving lower depth of cut.View full abstractDownload PDF (1078K) -
Kaoru KIKUCHI, Nobuo SHIKATA1984 Volume 18 Issue 35 Pages 15-25
Published: September 30, 1984
Released on J-STAGE: March 12, 2010
JOURNAL FREE ACCESSIn this report, the descaling conditions of annealed SUS 304 steel in electrolyte of sodium chloride and sodium nitrate are experimentally investigated.
The structures of the scale are determined by means of electron diffraction and X-ray diffraction.
The layer of the scale of the specimens are composed of two types of oxide; (1) oxide with a corundum structure, which is identified to be Cr2O3 and (Cr, Fe)2O3, (2) oxide with a spinel structure, which is identified to be Fe3O4 and FeCr2O4.
In the presence of some defects in the layer of the scale, the removal of scale on the steel can be accomplished by two stages of electrolytic descaling process; (1) 90% of the layer of the scale is removed by the electrolytic descaling in NaCl electrolyte. (2) To remove any remained scale and give passivity, it is electrolyzed at current density of 50 to 200mA/cm2 in NaNO3 electrolyte.
In the absence of any defect in the inner layer of the scale, the scale is removed by the dissolution of Cr-oxide of the scale during the electrolytic descaling in NaNO3 electrolyte.View full abstractDownload PDF (8948K) -
Koichi SEIMIYA1984 Volume 18 Issue 35 Pages 26-37
Published: September 30, 1984
Released on J-STAGE: March 12, 2010
JOURNAL FREE ACCESSEquilibrium electrode gap thickness is theoretically analyzed along a rectilinear path for electrolyte flow. Parameters of little effects on machining accuracy are neglected on basis of assumptions which were commonly used in the conventional ECM gap theories, so that very simple basic equations are obtained without introducing momentum equations for electrolyte flow. The effect of hydrogen gas void fraction, β on electrolyte conductivity is given by a fractional expression of f(β)=(1-β)/(1+λβ) which is an accurate approximation for f(β)=(1-β)n in the range of n=1.43-1.58, in order to cancel (1-β) included in a dominator in a basic equation. Thus for h* of dimensionless gap thickness is induced a quadratic equation of x*, including only ρH* of dimensionless hydrogen gas density, as a x*-dependent parameter. An approximation for ρH* with a straight line leads to determination of gap profiles in the form of parts of hyperbola without numerical calculation by electronic computer. Gap profiles are roughly classified into the types of ever-decreasing, intermediate-peaked and ever-increasing, with an index of dimensionless parameter A1 depending on voltage Eohm· A result of theoretical analysis denies the existence of the conventional optimal machining condition to form a constant gap along the flow path. In order to minimize gap variation along the flow path is proposed an alternative way of optimization, in which Eohm is periodically changed so that conditions of increasing and decreasing effects on the gap thickness compensate each other most.View full abstractDownload PDF (867K) -
[in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...1984 Volume 18 Issue 35 Pages 38-39
Published: September 30, 1984
Released on J-STAGE: March 12, 2010
JOURNAL FREE ACCESSDownload PDF (124K) -
[in Japanese]1984 Volume 18 Issue 35 Pages 40-45
Published: September 30, 1984
Released on J-STAGE: March 12, 2010
JOURNAL FREE ACCESSDownload PDF (550K) -
[in Japanese]1984 Volume 18 Issue 35 Pages 46-52
Published: September 30, 1984
Released on J-STAGE: March 12, 2010
JOURNAL FREE ACCESSDownload PDF (547K) -
[in Japanese]1984 Volume 18 Issue 35 Pages 53-59
Published: September 30, 1984
Released on J-STAGE: March 12, 2010
JOURNAL FREE ACCESSDownload PDF (696K)
- |<
- <
- 1
- >
- >|