Continuously Variable
Valve Timing (CVVT) system controls valve overlap with forcibly activating
the camshaft and adjusts EGR (Exhaust Gas Recirculation) amount. It
decreases exhaust gas (NOx, HC) and improves fuel economy, idle state,
torque in low speed and power in high speed. This system uses engine oil
pressure and consists of the two CVVT Oil Control Valve (OCV) in each bank
which supplies oil to cam phaser according to PWM (Pulse With Modulator)
signal of the PCM, a CVVT Oil Temperature Sensor (OTS) which detects the
oil temperature and a cam phaser which is installed on the end of the
camshaft and converts camshaft phase. The oil getting out of the CVVT oil
control valve flows into the cam phaser and rotates the rotor inside cam
phaser. At this time, the camshaft rotates with the rotor and the cam
phase is changed.
| 1. |
When camshaft rotates engine rotation-wise:
Intake-Advance / Exhaust-Retard |
| 2. |
When camshaft rotates counter engine
rotation-wise: Intake- Retard / Exhaust- Advance
|
