INFLUENCE OF THE MODES OF MOTION OF A LOGGING ROAD TRAIN DURING THE HAULING OF TIMBER ON THE EFFICIENCY OF ENERGY RECOVERY IN A PNEUMOHYDRAULIC FIFTH WHEEL COUPLING DEVICE

The necessity of increasing the efficiency of logging road trains by reducing the transport costs spent on hauling timber in existing road and climatic conditions is substantiated. A review of scientific research by foreign scientists is presented, which made it possible to identify the most significant factors influencing transportation costs. A promising design of a recuperative pneumohydraulic fifth wheel coupling device has been proposed, which makes it possible to reduce transportation costs by reducing the amount of fuel used by a road train, to increase the reliability of a logging road train by reducing the dynamic loads that occur between its links when driving over uneven surfaces of a logging road. The mathematical model of the movement of a timber tractor with a semi-trailer equipped with the proposed coupling device, under conditions of frequent accelerations and decelerations, over the unevenness of the logging road has been improved, which makes it possible to perform a preliminary assessment of the energy recovery by the proposed device in various modes of transient processes, as well as to investigate the influence of the main parameters of the recuperative pneumohydraulic fifth wheel coupling device for performance indicators. Two computer programs have been developed to study the performance indicators of a recuperative pneumohydraulic fifth wheel coupling under various transient modes of movement of a logging road train with given parameters of roughness of a logging road. It has been established that the use of the proposed coupling device in a logging road train makes it possible, when driving with randomly repeated decelerations and accelerations, to regenerate power up to 6.5 kW, and also to achieve a value of longitudinal acceleration of the semi-trailer relative to the tractor of 0.72 m/s2. Computer modeling made it possible to establish the value of the optimal diameter of the hydraulic cylinder, which provides the highest value of recuperated power at the lowest value of the acceleration of the semi-trailer relative to the tractor.