PISCO FUS20, Руководство пользователя, Страница: 23 / 36

Flow Sensor
Please be sure to read before handling the product. Please refer to "safety instructions", "common safety instructions for products listed in this manual", "common safety instructions for flow controller" from page 24 through 35.
> > > http://www.pisco.co.jp
Dependency of response on piping
Vacuum aspiration Vacuum aspiration Release (blow) Suction lift
Time （ msec ）
Gas is filled in piping B
5.5
5
4.5
4
3.5
3
2.5
2
1.5
1
0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400
0.5
Analog voltage output
(V
)
Gas released from
piping B
A ：φ 4 × 40 B ：φ 4 × 40
A ：φ 4 × 40 B ：φ 4 × 1000
A ：φ 4 × 1000 B ：φ 4 × 40
0.5(
l
/min)
0(
l
/min)
0.5(
l
/min)
− 0.3(
l
/min)
23
■ Suction lift verification
1.Response time
Response time during suction lift verification is
determined by the inner volume of piping, the
exhaust capacity of vacuum pump, and etc. When
piping like shown at right test circuit, for example, the
dependence of response time on piping becomes as
shown below. Based on this, to shorten response
time, the inner volume of piping should be minimized.
Pressure source （ 20kPa ）
Nozzle （ ø0.25 ）
A B
3-way valve
Test circuit
FUS20
Vacuum source （− 70kPa ）
2.Using collet nozzle
A collet nozzle is often used when the workpiece to be picked up should not be directly
seated against the nozzle. The collet nozzle is shaped like a pyramid so when the
workpiece is picked up, a gap forms at the four corners. This causes leakage during
pick up. If the effective sectional area of the piping, including valve and joints, etc., is
smaller than the collet nozzle and workpiece gap (effective sectional area), because
the flow is determined by the piping's effective sectional area, and the difference in flow
rate between suctioning and non-suctioning become small and hard to detect even by
flow sensor. In such case, suction lift can be accurately verified by making the effective
sectional area of piping larger as much as possible than the one of the gap between the
collet nozzle and workpiece.
A-A Cross section
Nozzle
Workpiece
Collet nozzle
A A