Shinku
Online ISSN : 1880-9413
Print ISSN : 0559-8516
ISSN-L : 0559-8516
Volume 11, Issue 10
Displaying 1-4 of 4 articles from this issue
  • Yoshitada MURATA, Kazunobu HAYAKAWA
    1968 Volume 11 Issue 10 Pages 349-355
    Published: October 20, 1968
    Released on J-STAGE: September 29, 2009
    JOURNAL FREE ACCESS
    Download PDF (866K)
  • Shigeo MATSUI, Nobuharu SHIBATA, Koichi KANAYA
    1968 Volume 11 Issue 10 Pages 356-363
    Published: October 20, 1968
    Released on J-STAGE: September 29, 2009
    JOURNAL FREE ACCESS
    Many attempts of electron beam machining have been performed in the field of production engineering. The manufactures of spinning nozzles which are most outstanding examples are described. To produce these nozzles, the electron beam machine consisting of tetrode electron gun, electrical beam alignment system, reducing lens and octo-pole deflection system with astigmatic corrector was used for the experiments. The beam spot size of about 10μm in diameter at 80 kV and 800μA and the power density ranging 8 × 105 to 2 × 106 W/cm2 are obtained. The spinning nozzles for hollow shaped fibres, which consist of 10 to 23 holes or more complicated nozzles can be easily drilled by an electron beam by programing controlled system, and machining time is few seconds. The drilled materials of these nozzles are stainless steel and glass plate (manufactured by Vycol Glass work Co.) with thickness 0.5mm and 2mm respectively. It was found to be the most distinguished features that the ratio of diameter to depth in the drilled holes can be reached to 1 : 100, and the interior surfaces of hole and slit are very smooth by microscopic observations. Spinning nozzle manufacture by electron beam instruments has great value for producing synthetic fibres.
    Download PDF (2994K)
  • Hiroshi NAKAGAWA, Kyon Ju CHIN
    1968 Volume 11 Issue 10 Pages 364-372
    Published: October 20, 1968
    Released on J-STAGE: September 29, 2009
    JOURNAL FREE ACCESS
    When a cold system installed to a vacuum apparatus is cooled to obtain an ultra high or extreme high vacuum state, one often faces the problem of “cold leak”. In this paper we report the first quantitative measurement of “cold leak” of liquid nitrogen through aluminium welding faults whose leak rate of room temperature helium gas is 10-21 lusec. At 1 atm the leak rate of liquid nitrogen is about 8 times larger than that of nitrogen gas of room temperature at 1 atm, and when the pressure of liquid nitrogen is increased to 2 atm and 3 atm the leak rate becomes about 40 and 100 times respectively. This remarkable pressure dependance of liquid nitrogen leak rate is studied from a simple theory.
    Download PDF (1200K)
  • Akira KINBARA
    1968 Volume 11 Issue 10 Pages 373-379
    Published: October 20, 1968
    Released on J-STAGE: September 29, 2009
    JOURNAL FREE ACCESS
    Download PDF (3255K)
feedback
Top