Optimization of Structural Parameters by Improvement of Pneumohydraulic Fifth-Wheel Coupling Device at Semitrailer Hauling Rig

In this study, the benefits of logging transportation under modern conditions by semitrailer hauling rig are examined, which consists of a truck tractor connected to a semitrailer. Furthermore, an analysis is made of the operational implications of using log road trains in insufficiently arranged road conditions. The article describes the potential scientific directions that can optimize the efficiency of semitrailer trucks. An improved construction of a regenerative fifth-wheel coupling device is proposed. It provides better reliability, reduces fuel consumption for log trucks, and gives better working conditions for drivers, along with reduced dynamic loads between the links of the units that occur during the movement in unsteady modes. The research methodology includes the application of the mathematical framework of multifactorial optimization. The specified analytical formulas are derived to determine the performance efficiency of the regenerative fifth-wheel coupling. It is revealed the connections between the hydraulic cylinder piston stroke values of the regenerative fifth-wheel coupling device, the weight of the loaded semitrailer, the vehicle acceleration during speeding up and braking, and the modifications of the performance indicators of the latching mechanism. The optimal value of the stroke of the pistons of the hydraulic cylinder is determined, which is 200 mm. It provides a power recovery of 6.5 kW and better longitudinal acceleration of the semitrailer at 0.72 m/s2. Moreover, it is found that the change in acceleration during the increase in velocity and braking from 1 to 3 m/s2 gives the change in recuperated power from 2.2 to 6.8 m/s2. At the same time, the average longitudinal acceleration of the semitrailer varies from 0.27 to 0.75 m/s2. Changing the load of the semitrailer from 5 to 25 tons allows increasing the recuperated power from 1.6 to 7.9 kW and reducing the longitudinal acceleration of the semitrailer from 2.8 to 0.53 m/s2. The influence graphs and optimization cartograms present the diameter and hydraulic cylinder piston stroke values of the regenerative fifth-wheel coupling device on the regenerated power and longitudinal acceleration of the semitrailer. According to the optimization cartograms, the average regenerative power is determined using a graph-analytical method. It is equal to 6.5 kW with the diameter of a regenerative hydraulic cylinder of 110 mm and a hydraulic cylinder piston stroke of 200 mm.  For citation: Posmetyev V.I., Nikonov V.O., Manukovskii A.Yu., Posmetyev V.V., Avdyuhin A.V. Optimization of Structural Parameters by Improvement of Pneumohydraulic FifthWheel Coupling Device at Semitrailer Hauling Rig. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 3, pp. 126–139. (In Russ.). https://doi.org/10.37482/0536-1036-2023-3-126-139