The effect of cylinder deactivation on the unevenness of the torque of an internal combustion engine

Abstract

One way to improve the energy efficiency of cars under partial loads is to deactivate some of the cylinders in their internal combustion engines. Torque unevenness affects the dynamic properties of a car and its energy efficiency. This study investigated the effect of disabling some of the cylinders on the unevenness of the indicator torque of internal combustion engines. Many studies have proposed a cyclic elastic-dynamic efficiency coefficient to assess the energy efficiency of engine-transmission systems. However, these studies did not determine the effect of disabling some of the cylinders on the unevenness of the indicator torque when the external load on the internal combustion engine is reduced. In order to assess the effect of cylinder deactivation on the unevenness of the indicator torque of an internal combustion engine installed on a car, it is necessary to conduct research and solve the following tasks: determine the change in the coefficient of unevenness of the indicator torque when deactivating part of the cylinders of an internal combustion engine and the maximum number of cylinders that can be deactivated while ensuring the movement of the vehicle. Studies show that regardless of the number of cylinders shut down, the coefficient of unevenness of the indicator torque does not change. At the same time, both the amplitude of the indicator torque fluctuations and its average value decrease. It has been shown that when the maximum effective power of the Nemax engine and the average effective power of the Ne engine are achieved during operation, up to half of the cylinders can be disabled. When some of the cylinders of an internal combustion engine are deactivated, the external resistance to the movement of the vehicle may increase. By utilizing the maximum power in the cylinders that remain operational, an assessment was made of the possibility of overcoming this resistance. For further research, the question arises as to the feasibility of achieving maximum indicated power in each disabled cylinder of the internal combustion engine. To resolve this issue, it may be more rational and economically feasible to connect some of the disabled cylinders. The results of this study can be used in the future to assess the energy efficiency of vehicles.