The simulation modeling of the operation of a recuperative pneumohydraulic drawbar of a road train coupling device with a self-pulling function

Based on the conducted exploratory research, the most significant factors were identified on which the change in transport costs spent by logging enterprises on the process of delivering timber to consumers by logging trucks depends. To reduce such costs, a promising design of the drawbar of the coupling device of a timber road train has been proposed, providing the effect of self-pulling of the road train, generating and storing the energy of the working fluid, with its subsequent use in technological hydraulic equipment. To simulate the movement of a timber road train equipped with the proposed drawbar of the coupling device and the operation of the drawbar separately in the modes of self-pulling, recovery and damping of dynamic loads, two computer programs have been developed. It has been established that with an increase in the depth of irregularities, self-pulling of a timber road train becomes more difficult, which leads to a deterioration in the efficiency of the self-pulling process. However, with an average depth of unevenness of the supporting surface of less than 0.3 m, the efficiency indicators of the self-retracting process are acceptable values: the self-retracting speed is more than 0.22 m/s, the amount of displacement per extension-reduction cycle of the drawbar of the coupling device is less than 0.12 m, consumed by the pneumohydraulic drawbar of the coupling device power less than 1.9 kW. Under very difficult road conditions – the average depth of irregularities is from 0.3 to 0.5 m – the self-pulling of the timber road train occurs, but the efficiency indicators decrease: the self-pulling speed decreases to 0.16 m/s, the movement increases to 0.17 m, power consumption increases to 3.1 kW. It was revealed that when the coefficient of viscous friction of the wheels of a logging road train against the supporting surface of a logging road changes over a wide range, the recuperative pneumohydraulic drawbar of the coupling device provides a fairly effective self-pulling with a self-pulling speed from 0.17 to 2.3 m/s, a displacement (rollback) value from 0.09 to 0.16 m, power consumption from 1.5 to 2.2 kW.