Optimization of the design parameters of the regenerative hitch installed in a logging vehicle with a trailer

This article solves the problem of increasing the efficiency of the functioning of logging road trains in conditions of insufficiently equipped logging roads. Experience in the operation of road trains on such logging roads shows that on these roads the transport and operational qualities of logging road trains are low. The relevance of the scientific direction, aimed at achieving the fuel efficiency of logging road trains and thus increasing the efficiency and competitiveness of logging enterprises, is substantiated. An analysis of the work of foreign scientists is presented, which made it possible to identify significant factors that largely determine the efficiency of the process of hauling timber by timber road trains. A promising design of the coupling device is proposed, which allows converting and usefully using the kinetic energy of the mass of the trailer with timber, which occurs during the movement of a road train along insufficiently equipped logging roads in unsteady and transient traffic modes. The study was based on mathematical and simulation modeling, numerical methods, as well as modern methods for obtaining and processing information with computer support. A mathematical model and a computer program for the movement of a timber road train under changing road conditions have been developed. Computer simulation made it possible to carry out a preliminary assessment of the performance of the proposed pneumohydraulic coupling device with recuperative and damper mechanisms by identifying and analyzing dependencies characterizing the change in the studied performance indicators on the driving conditions of the road train and the design parameters of the device. It has been established that the coupling device during the movement of a logging road train in difficult road conditions at a speed of 30 km/h makes it possible to recuperate up to 7 kW, while the value of the longitudinal acceleration of the trailer link relative to the logging vehicle does not exceed 0.83 m/s2. It is determined that the value of the optimal diameter of the recuperative hydraulic cylinder is 80 ... 100 mm, and the optimal piston stroke is 83 ... 100 mm. In this case, the average power recuperated by the device will be at least 7 kW, and the average longitudinal acceleration of the trailer will be no more than 0.8 m/s2. It was found that the developed recuperation system remains effective in a wide range of roughness heights of 0.2 ... 0.4 m, providing a recuperated power of 2.3 ... 19.7 kW, respectively, with an acceptable average longitudinal acceleration of 0.3 ... 2.2 m/s2. The results obtained will be used as recommendations for designers to refine the proposed coupling device at the design stage.