Abstract
Keywords automobile, differential, lock-up, traction, simulation
Abstract A reduction of operation expenses and an increase of the automobiles efficiency in different road and climatic conditions are a primary line to develop motor transport. At the same time the optimum vehicles design parameters for one operational condition in other case can result in the low efficiency. To improve this producers optimize functioning modes first of all for engine and transmission units in the structure of the automobile, and electronic microprocessor systems help to control these units.
While automating automobiles axle and wheels drives, some difficulties arise to achieve the optimum plan of tractive forces distribution between driving axle and wheels in the contact with a road, when expenses of engine power will be least to get over resistance to movement. It influences on the vehicles efficiency directly. An application of a differential drive for driving axes and wheels on heavy-duty-automobiles in heavy road leads to loss its passability. An inopportune switching-off of blocking mechanisms while moving on roads with the advanced cover (high friction) overloads transmission details, wears out tires and increases fuel consumption.
There are automatic systems, in which the control of differentials lock-up mechanisms is realized on the base of frictional clutches. However we consider there are scientific and engineering problems of making such electronic systems for heavy-duty-automobiles. To get over one, firstly, it is necessary to use mechanical gear clutches. Secondly, the creation of a method for recognition of optimum periods to switch on and off them is required. Thirdly, it is necessary to take into account, that weight of the automobile can vary widely from equipped up to complete.
The decision of these problems is executed by the authors on an example of the all-wheel-drive automobile MAZ-5309. There were calculated characteristics of an electronic system to control interaxial and interwheel differentials lock-up mechanisms. Also proposals were created for designing of the system and the algorithm for controlling differential lock-up mechanisms was developed.