3.3 Function
When the VTEC unit is switched on, it is sup-
plied with compressed air (5 to 8 bar) and
with lubricant (0,1 to 0,5 bar).
The lubricant flows through the different
bases to the volumetric pneumatic micro-
pump. The delivery frequency of the micro-
pump ( max. 3 stroke/s) is independently ad-
justed with either a pneumatic pulse
generator or a solenoid valve, which is con-
trolled via a control unit. The flow rate of the
micropump can be adjusted with metering
rings or with a thumb wheel.
The micropump delivers a metered quan-
tity of lubricant, which goes through inner
channel of the base to the coaxial outlet port.
The lubricant flow can be monitored at the
micropump outlet with a flow sensor type
GS304P.
The compressed air also flows through
the different bases and is divided in two ways
in each of them. Some compressed air is
supplied to the micropump to actuate it. The
other part of the compressed air (called car-
rier air) is supplied to the coaxial outlet port
and goes through the outer tube of the hose.
The carrier air pressure of every base can be
adjusted with a pressure regulator. This
pressure can be also monitored by means of
a manometer or a pressure switch.
The low-pressure carrier air and lubricant
are simultaneously transported via the co-
axial hose to the nozzle. The carrier air is
swirled in the nozzle. As a result, the me-
tered quantity of lubricant is broken down
into microdroplets, which are transported by
the carrier air to the friction point without
causing any mist. The microdroplet size
(200/600 μm) ensures a perfect lubricant
coating without atomization.
Fig. 2
1
2
3
Projection nozzle for VTEC
1
Carrier air
2
Lubricant
3
Turbulence zone
17
