Enhancement of functionality of tractor-drawn berry-harvesting combines

The paper deals with the experience of development of a tractor-drawn berry-harvesting combine that is similar in the ease of control to a self-propelled analog. The purpose of the research is to explore the possibility of separating the function of maintaining combine parallel alignment to the row of harvested plants from the problem of control of its lateral displacement in relation to the tractor. This problem has been solved by transforming of conventional drawbar hitch, having only one control hydraulic cylinder, into the hydraulic analog of a parallel link mechanism. For this purpose, the design was complemented by two hydraulic cylinders and a pivot arm, and combine was equipped with self-aligning supporting wheels. As a result, the moment of resistance to rolling of combine wheel, that is asymmetric to the tractor position, is transmitted to its frame and does not lead to harvesting machine skewness in relation to rows of plants fixed on a vertical trellis. Geometric and hydraulic parameters of the drawbar hitch are chosen, so that when the tractor leaving the row spacing turns to the left, it is deflected by 90 degrees in relation to the combine, which, after the tractor entry into another row spacing, exactly sets on the next row. In this case, the turning radius of the unit does not exceed 6 m. During the tests by means of control system borrowed from a grain combine harvester, the experimental machine was controlled by a mechanic, who sat on the combine above a row of plants. In machines of mass production, his function is to be performed by the automatic control system. The tests of tractor-drawn berry-harvesting combine showed the potential possibility of assurance of its control accuracy at the level, similar to a self-propelled vehicle. In this case, its price in comparison with self-propelled analogs could be twice lower. Thus, it allows to bring the berry-harvesting and grape-harvesting combines to higher level of operational excellence, significantly increasing their competitiveness in comparison with self-propelled harvesting machines.

berries, grapes, mechanized harvest of berries, tractor-drawn combine