Suzuki Liana RH418, Supplementary Service Manual

Page: 129 / 371

Engine Mechanical: 1D-3
Oil control valve
The oil control valve switches and adjusts the hydraulic
pressure applied to the cam timing sprocket by moving
the spool valve (1) according to the duty pulse signals
output from the ECM. By this operation, the intake valve
timing is varied continuously. Signals output from the
ECM are the duty pulse of about 240 Hz.
Cam timing sprocket
The cam timing sprocket is equipped with the chambers
for timing advancing (2) and retarding (3) which are
separated by the rotor (5). The rotor rotates receiving the
hydraulic pressure applied to both the chambers. The
sprocket (1) is installed on the housing (4) and the rotor
is secured on the intake camshaft by fastening the bolts.
Therefore, the actuation of the rotor makes the phase
difference between the sprocket and intake camshaft.
Timing advancing
When the duty ratio of the signal output from the ECM is
heavy, the spool valve (4) of the oil control valve moves
to the left (opposite direction against the coil (5)). By this
spool valve movement, the pressurized oil (1) is led into
the chambers for timing advancing and the oil in the
chambers for timing retarding is drained. This operations
actuate the rotor (3) and result in the advanced timing of
the intake valve.
Timing holding
When the duty ratio of the signal output from the ECM
shows that of holding, the spool valve of the oil control
valve is located at hold position. Because this condition
generates no oil pressure changes in both chambers,
the rotor is fixed at a target position.
6. Seal
1
I3RH0B140003-01
1
2
3
4
5
6
I3RH0B140004-01
2. Drain
1 2
5
4
3
I3RH0B140005-01
I3RH0B140006-01