-10-
No. TQ1230001-OM101-A
3.2. Flow rate / Exhaust characteristics
■
Flow rate / Exhaust characteristics.
The flow rate characteristics correspond to the standard supply pressure (0.5MPa).
*
The actual suction flow at the point of suction varies depending on the piping conditions to the vacuum port.
■
How to read flow rate characteristics Graph
Flow rate characteristics are expressed in ejector vacuum pressure and suction flow. If suction flow changes,
the vacuum pressure will also be changed. Normally this relationship is expressed in ejector standard
operating pressure use. In the graph, Pmax is maximum vacuum pressure and Qmax is maximum suction
flow. The values are specified according to catalog use. Changes in vacuum pressure are expressed in the
below order.
1. When the ejector suction port is covered and made airtight, the suction flow becomes zero and vacuum
pressure is at the maximum value (Pmax).
2. When the suction port is opened gradually, air can flow through, (air leakage), suction flow increases, but
vacuum pressure decreases. (condition P1 and Q1)
3. When the suction port is opened further and fully opened, suction flow moves to the maximum value
(Qmax), but vacuum pressure is near zero (atmospheric pressure).
As described above, the vacuum pressure changes when the suction flow changes. In other words, when
there is no leakage from the vacuum port, the vacuum pressure can reach its maximum, but as the
amount of leakage increases, the vacuum pressure decreases. When the amount of leakage and the
maximum suction flow become equal, the vacuum pressure becomes almost zero.
In the case when a ventilative or leaky workpiece should be adsorbed, take note that vacuum pressure
will not rise.
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S
uc
ti
on
f
low
[L/
m
in(
A
N
R
)]
A
ir
c
on
s
um
pt
ion
[L/
m
in(
A
N
R
)]
V
a
c
u
u
m
p
re
s
s
u
re
[k
P
a
]
Supply pressure [MPa]
Air consumption
Flow rate characteristics
Exhaust characteristics
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0
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V
a
c
uu
m
pre
s
s
ure
[k
P
a
]
Suction flow [L/min(ANR)]
