Kharkіv National Automobile and Highway University
Abstract
Abstract. Problem. A significant amount of research has been devoted to the dynamics of car acceleration. They determined the maximum dynamic performance of a car due to the adhesion of the wheels and the supporting surface; analytical dependencies were obtained connecting the maximum possible acceleration, the minimum time and the acceleration path with the vehicle speed; the considered issues associated with the use of combined power plants, etc. However, these studies almost did not consider the option of controlling the car acceleration using a continuously variable gearbox. Goal. The aim of this research is the improvement of dynamic properties and energy efficiency of cars through the implementation of rational laws of changing the gear ratio of a continuously variable gearbox at a constant speed. Methodology. The use of continuously variable gearbox can improve the performance of the dynamic properties and energy performance of vehicles. When the engine is running at a constant speed the acceleration of the car will be an infinitely variable reduction gear ratio of the transmission range from the maximum to the minimum value. Saving energy is realized by provision of optimal car running, as well as by the exclusion of costs for the acceleration of the rotating masses when shifting and the change in angular velocity of the crankshaft. Results. The work investigated the possibility of controlling the acceleration of a car with a stepless change in the transmission ratio and engine operation at a constant crankshaft rotation speed. At the same time the effective mode of constant engine power, and the mode of change of the engine output according to a linear law were also considered. Originality. As a result of this research, we developed dynamic mathematical models of the acceleration of a car with a continuously variable gearbox at a constant angular velocity of the crankshaft. Calculated dependencies have been obtained that allow assessing the impact of the design and operational parameters of a vehicle and its engine-transmission unit on the acceleration dynamics. The functions of rational change in the gear ratio of a continuously variable transmission have been determined and recommendations have been formulated to improve the dynamic and economic performance of the vehicle. Practical value. This article is devoted to the analysis of the car dynamics acceleration and is aimed at improving its dynamic characteristics and energy efficiency. The obtained results can be used in the design and research of engine-transmission systems with internal combustion engines.Аннотация. В работе исследуется динамика разгона автомобиля, оборудованного бесступенчатой автоматической коробкой передач и двигателем внутреннего сгорания, который работает на постоянном скоростном режиме. Получены расчетные зависимости, позволяющие количествено оценить влияние параметров автомобиля на динамику его разгона. Сформулированы рекомендации по улучшению динамических свойств и энергетической экономичности автомобилей.Анотація. У роботі досліджується динаміка розганяння автомобіля, обладнаного безступінчастою автоматичною коробкою передач і двигуном внутрішнього згоряння, що працює на постійному швидкісному режимі. Отримано розрахункові залежності, які дозволяють кількісно оцінити вплив параметрів автомобіля на динаміку його розганяння. Сформульовано рекомендації щодо поліпшення енергетичної економічності й динамічних властивосте автомобілів