Basic idea of vacuum die casting

Vacuum industrial definition

「Pressure of specific space is lower than atmospheric pressure」(JISZ8126)
Image of basic idea

< Reference Vacuum unit >

P2(Specific space )<P1
(Atmospheric pressure)

<Refer, Unit vacuum>
  • Low Vacuum 100kPa~ 100Pa
    (Common vacuum die casting)
  • MidVacuum   100Pa ~ 0.1Pa
  • HighVacuum    0.1Pa ~10-5 Pa

Vx S > V1x S1

Please refer to left picture, cross section of valve is decided by following condition.
Exhaust speed   V=250 〜 280m/s (Sound velocity  340m/s)
  • V : Exhaust speed
  • S : Valve cross section
  • V1 : Plunger speed
  • S1 : Plunger cross section