А grain harvester performance according to unloading time and modes

G. Tihanov

Department of Agricultural Engineering, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 1 November 2018; accepted for publication 18 February 2019)

Abstract. The paper presents an analysis of the two ways of unloading the harvester grain hopper – unloading at standstill and unloading on the move. A passive experiment has been carried out during wheat harvest by measuring the loading time of a full harvester hopper into the transport vehicle. During its time measurement it has been found that for 237.4s the harvester is stopped and does not reap and does not perform actual output. The actual grain harvester output when unloading at standstill has been determined 17.15t/h (25.22 da/h) and the actually possible output if the harvester runs the same performance and unloads on the move it will reach an output of 20.91t/h (30.74 da/h), i.e. its output will increase by 19%. It has been found out that crop harvesting times can be shortened if the method unloading on the move is used, by about one day in harvesting the crop, respectively.

Justification of a method for determining the moment for switching on the level one signaling of filled grain harvester hoppers

G. Tihanov1*, B. Kolev2, K. Trendafilov3, N. Delchev1, Y. Stoyanov1

1Department of Agricultural Engineering, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
2Department of Agricultural Machinery, Agrarian and Industrial Faculty, “Angel Kanchev” University of Ruse, 7017 Ruse, Bulgaria 3Department of Mechanical Engineering, Faculty of Technics and Technologies – Yambol, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 4 January 2017; accepted for publication 11 April 2017)

Abstract. The main issue in the joint operation of a grain harvester and a transport vehicle is determining the moment when the vehicle has to start travelling to the harvester, so that it will arrive at it when the hopper is full. The result of the incorrect determining of that moment is that the productivity of the transport vehicle is not efficiently used and in the case when the hopper is unloaded at a harvester stantstill position, the harvester productivity is also reduced due to more frequent stops. The article proposes a method for determining the part of the grain harvester hopper volume after the filling of which the signalling shall be switched on indicating to the vehicle driver when to start moving toward the harvester. The results of real measurements are shown on different farms of the time of movement of the vehicle to the harvester for unloading. An analysis of the results has been made on the basis of the developed method as well and recommendations have been made to regulate the time of switching on the signalling. A nomogram has been proposed for determining the part of the grain hopper volume after the filling of which the signalling is to be switched on depending on the ratio between the time for moving of the vehicle and the time for filling the grain harvester hopper to the top.

Method for rapid determination of the percentage rate of grain losses by the combine harvester according to its parameters

N. Delchev, K. Trendafilov
Abstract. There is a direct connection between the loss of grain during harvest and the working speed of the harvester. At the same time the speed is determining for the productivity of the machine. Therefore, the contemporary harvesters have an electronic system that allows monitoring of the grain losses and enables the operator of the machine to control the speed according to the acceptable levels of losses. In order to set this system, it is extremely important to determine the acceptable level of losses not by intuition but by using exact and precise data. In this article dependencies have been derived that take into account the various parameters of harvesters as well as the yield from the relevant field.