Development of the road train with three-class tractor unit and the fifth-wheel coupling

Abstract

The analysis of the road transport market state and the carriers structure was made, it gave an opportunity to evaluate the necessary parameters of the vehicle. It has been found that in recent years for commercial needs the average daily mileage and the weight of cargo for transportation has decreased. Consequently, optimizing transport costs requires adjusting the vehicle in the direction of reducing load capacity and improving universality. Foreign experience has shown the perspective of the chosen direction for the technology improvement. The road trains with a fifth-wheel coupling have advantages over the road trains with a ball hitch, because at the same load carrying capacity they have a smaller length, a less hunting, a simpler construction and a lower coefficient of metal intensity. In addition, the use of the road trains with a fifth-wheel coupling allows you to increase the running speed, reduce the idle time under load and unloading due to its operation with two or more semitrailers and, most importantly, extends the possibilities of the road trains specialization. It was focused on the creation of a road train on the basis of a small-tonnage truck "GAZelle" for the use optimize of the vehicle characteristics (body space, loading capacity). It offered the multipurpose road train with a fifth-wheel coupling on the basis of the "GAZelle" vehicle. This one is the GAZ-3302 base chassis, on which the fifth-wheel coupling is mounted. It can work with semi-trailers of any destination: cargo platform, industrial and iso-thermal vans, refrigerator, road vehicle tow truck, horse trailer, etc. It is also promising to use the proposed road train for small farms. One tractor unit vehicle allows, depending on the type of semitrailer (tank trailer, tilt trailer, open platform), to perform various transportation tasks. The proposed semi-trailer is a metal welded platform with folding rear and side boards, complete with arches and awning, height with a tent to 1750 mm. The carrying capacity of a semi-trailer is 5000 kg, the unladen weight is 1050 kg. The total weight of the trailer is 7300 kg. The road train is intended for transportation of a long loadings (up to 5.7 m) of limited weight (up to 5.0 t) in the conditions of administrative-territorial restrictions imposed on the use of heavy transport with a big length of the cargo platform (provision of construction and supply of organizations in the central part of the city), small batches of building materials (boards, pipes, fittings, insulation, etc.), home and office furniture in the assembled kind or non-standard sizes, spatial structures of industrial or decorative purpose from the light-metal alloys, plastic or wood. In this case, the small (up to 980 mm) loading height of the semi-trailer should play an important role. The design of the single-handed fifth-wheel coupling is also reviewed. It is proposed for installation on the developed tractor unit.