Description And Operation: Description

Continuous Variable Valve Timing (CVVT) system advances or retards the valve timing of the intake and exhaust valve in accordance with the ECM control signal which is calculated by the engine speed and load.

By controlling CVVT, the valve over-lap or under-lap occurs, which makes better fuel economy and reduces exhaust gases (NOx, HC) and improves engine performance through reduction of pumping loss, internal EGR effect, improvement of combustion stability, improvement of volumetric efficiency, and increase of expansion work.

This system consists of

• the CVVT Oil Control Valve (OCV) which supplies the engine oil to the cam phaser or cuts the engine oil from the cam phaser in accordance with the PWM (Pulse With Modulation) control signal of ECM.
• the CVVT Oil Temperature Sensor (OTS) which measures the engine oil temperature,
• the Cam Phaser which varies the cam phase by using the hydraulic force of the engine oil.

The engine oil transferred from the CVVT oil control valve changes the cam phase in the direction of the engine rotation (Intake Advance/Exhaust Retard) or the opposite (Intake Retard/Exhaust Advance) by rotating the rotor connected to the camshaft inside the cam phaser.