Engine technology: What is the difference between continuously variable valve timing and CVVT, D-VVT and C-VTC continuously variable valve timing intelligent control systems?

1, different working modes: cvvt air intake is variable, and only the intake camshaft is driven by vvt. Dvvt is a continuous variable air intake and exhaust, both of which are available, so the air intake methods adopted by these two machines are different.

2. Different fuel consumption: Due to the different operation modes of the two machines, the fuel consumption is also different. Like CVTC, CVVT is a continuously variable intake valve timing with constant valve lift, while DVVT is a continuously variable intake valve timing and exhaust valve timing with constant lift.

3. Different technologies: Intelligent Variable Valve Timing System (VVT-i) is Toyota's unique engine technology, while Continuous Variable Valve Timing System (CVVT) is developed by South Korea on the basis of VVT-i and i-VTEC, which makes fuel burn more fully by controlling the opening and closing of valves.

Extended data:

ECM of Toyota VVT-i engine automatically searches for the optimal valve timing corresponding to engine speed, intake air, throttle position and cooling water temperature under various driving conditions, and controls the camshaft timing hydraulic control valve.

This technology senses the actual valve timing through the signals of various sensors, and then implements feedback control to compensate the system error and achieve the optimal valve timing position, thus effectively improving the power and performance of the automobile and reducing fuel consumption and exhaust emissions.

CVVT technology is to delay the opening time of intake valve and reduce the valve overlap angle when the engine is running at low speed and low load (idle state) to stabilize the combustion state. When the engine is running at low speed and heavy load (starting, accelerating and climbing), the opening time of intake valve is advanced and the valve overlap angle is increased to obtain greater torque.