Technical means for determining the load of working enforcers of agricultural machines

Abstract

The characteristics of a machine-tractor unit are determined by the indicators of the traction resistance of an agricultural machine, which require an experimental determination. The disadvantages of the known devices that provide measurements during volumetric dynamometry of the working enforcers of tillage machines are the complexity of the design and high measurement error. To improve the accuracy of experimental measurements of the dynamic loading of the working bodies of tillage machines, it is necessary to improve the technical means of measurement. Experimental determination of the loading of working bodies requires the use of a system of force sensors that affect the working bodies in different planes. Force sensors are manufactured mainly using strain gauges that are glued directly to the loaded parts. To determine the forces in the traction of the hydraulic suspension system of tractors, strain gauge fingers are used. It is shown that for the same distances of the sensors, the resulting signal does not depend on the distance of the force applied on the finger axis. Usually, force sensors are calibrated one at a time on special stands. The best calibration results will be achieved when all tenzometric fingers are installed in their proper places and all sensors are calibrated simultaneously. To do this, the intermediate plate is fixed using strain fingers on the levers of the tractor hydraulic suspension. Rymbolts are installed on the plate, to which a known force is applied three times and the readings of each of the strain fingers are taken. Solving the resulting system of equations, simultaneously find all the calibration coefficients. Additionally, a device is proposed, the kinematic scheme of which allows using a single measuring device, which simplifies the technology of measuring the force on the working body and increases its accuracy.