muutuvventiilide

Muutuvventiilide, often translated as variable valves or variable valve timing (VVT), refers to a system used in internal combustion engines that allows for the timing of the intake and exhaust valves to be altered. This adjustment is typically controlled by the engine's control unit (ECU) based on various operating parameters such as engine speed, load, and temperature. The primary goal of VVT is to optimize engine performance, fuel efficiency, and emissions across a wider range of operating conditions than a fixed valve timing system can achieve.

By advancing or retarding the timing of valve opening and closing, VVT can improve volumetric efficiency. For instance, at low engine speeds, retarding the intake valve timing can reduce valve overlap, preventing the escape of unburnt fuel-air mixture into the exhaust, which improves low-end torque and reduces emissions. Conversely, at high engine speeds, advancing the intake valve timing can increase valve overlap, allowing more fresh charge into the cylinder and better scavenging of exhaust gases, thereby increasing peak power output.

Different VVT technologies exist, including continuously variable valve timing (CVVT) and discrete variable valve timing (DVVT). CVVT systems offer a seamless range of adjustment, while DVVT systems typically provide a few distinct timing positions. The implementation of VVT has become increasingly common in modern gasoline and diesel engines due to its significant benefits in enhancing overall engine operation and meeting stringent environmental regulations.