Cylinder deactivation, also known as variable displacement technology, means that when the engine is running under partial load, the fuel supply, ignition, intake and exhaust of some cylinders are cut off through relevant mechanisms, and the engine is stopped. Its operation increases the load rate of the remaining working cylinders to improve efficiency and reduce fuel consumption.
Working principle: The control computer of the automobile cylinder deactivation control fuel-saving device determines when and how to deactivate the cylinder according to the vehicle load (throttle position, engine speed, vehicle speed, gear position, water temperature, air conditioning, etc.) cylinder. When cylinder deactivation is required, the intake and exhaust valves are immediately closed through the cylinder deactivation mechanism, and the corresponding fuel injection system is also closed. At this time, the piston is in the compression stroke, and the gas in the cylinder is compressed, consuming work; during the suction stroke and expansion stroke, the compressed gas expands, doing work to the outside world. Theoretically, if there is no leakage loss and heat loss, then the compression work and expansion work exactly offset each other, causing the cylinder to form an air spring cavity; in addition, since the valve spring also stops working, the corresponding mechanical losses are also reduced.