The operation of the machine attached to the back of the tractor to clean the heads of root crops from residues in the case of using copying pneumatic wheels causes oscillations of the tops harvester in the vertical plane, which significantly affects the quality of the process. Accordingly, the movement of the horizontal working body will depend on many structural and kinematic factors. Therefore, the development of a mathematical model that will describe the movement of the working body of such a unit is an important task. To solve which the method of construction of calculated mathematical models of functioning of agricultural machines and machine units, on the basis of theoretical mechanics and higher mathematics was used in the work.. Using which the equivalent scheme of movement of the unit is developed and the system of two nonlinear differential equations for detailed research of oscillations of the cleaner of heads of root crops in the longitudinalvertical plane at movement of its pneumatic copying wheels on roughnesses of a surface of soil is received. The mathematical model of movement of the cleaner with a horizontal cleaning shaft developed on the basis of initial equations of dynamics in the form of Lagrange of the 2nd kind allowed to establish depedencies between constructive and kinematic parameters of the car and its oscillatory characteristics. The found dependences created preconditions for the further mathematical modeling of parameters of the rear-mounted cleaner of heads of root crops, with a horizontal clearing shaft. Using the developed calculation model it is possible to optimize the values of angle B and coordinates у that characterize the oscillations of the machine in the longitudinal-vertical plane.
Mechanization in agriculture & Conserving of the resources
Vol. 67 (2021), Issue 1
Table of Contents
MECHANIZATION IN AGRICULTURE
The article examines the single and complex indicators of the operational reliability of agricultural machinery (tractors and combines) operating in the special soil-climatic and dynamic conditions of Georgia, highlights the least reliable units and parts that require constructive improvement.
As a result of research, according to the methodology of probabilistic and statistical modeling developed by us, integral and differential distribution functions of reliability indicators were obtained, their general characteristics were determined, as well as mathematical models and the values of reliability indicators were determined taking into account the distribution law. The adequacy of the probabilistic-statistical models was tested using the Pearson and Kolmogorov goodness-of-fit tests.
As a result of theoretical and experimental studies, characteristic malfunctions and failures of the main units of foreign ag ricultural equipment operating in Georgia have been established, and constructive and technological measures to improve reliability have been developed.
As crop and animal production are interconnected, they together form the basic branch of agriculture. A great sense in the process of replacing cultivated crops is the cultivation of sugar beet, which can act as a breaker in planting of narrow row crops, livestock feed or green manure. In addition to seed development, cultivation technology has also been improved, and by that the technique has been modified. During cultivation, it is difficult to prepare the soil before sowing together with a good settlement of seeds in the soil, which creates suitable conditions for germination and subsequent emergence of plants. In the submitted article, we have focused on the evaluation of chosen indicators of intermittent speeder’s work quality. The measurements have been performed in accordance with the ISO 7256/1 standard for the evaluation of sowing equipment with intermittent sowing. The vertical distribution of the seed in the soil for field emergence at the seed base of the seeder Kverneland Accord Monopill S, at different working speeds, has been observed. The experiment was performed on aluminous-sandy soil with a soil moisture of 18.2%. In measuring the sowing depth, there were used two measuring systems, the so-called contact (inductive) sensor and non-contact (ultrasonic) sensor in connection with A / D converter with storage in IM memory card. Based on the obtained results, we can state that by increasing the travel speed from 1.11 m.s-1 to 3.33 m.s-1, the depth of the sowing foot was reduced on average by 19.61 mm.
Selection of the information parameter for the thermography method of diagnostics of dairy cows mastitispg(s) 14-18
In the paper are presented experimental results of exploring the thermography method of diagnostics of dairy cows mastitis depending on the basic used information parameter. Prospects for embedding the information on the udder thermography results into the herd management system are discussed.
Kinematics, working parameters and modes of swing-type digging share of elevator-type potato combinepg(s) 19-22
The article presents an analysis of the kinematics, working parameters and modes of operation of swing-type digging share with elliptical profile cutting edge, and opportunities for rational operating regime adjustment of the working body under the conditions of operation. Expressions are derived and an analysis of kinematics, working and regime parameters of the swing-type share with elliptical cutting edge is given.
Features of calculation of agricultural machines trailed devices in pedagogical technologies of training agricultural engineers for innovative design activitiespg(s) 23-25
The scientific-technical and pedagogical-methodological model of preparation of future specialists in agroengineering for innovative project activity on the basis of studying of agricultural machines on modern technologies of training, deepening of scientific activity of students based on features of calculation of trailers which are used in machine-tractor units has been developed. An equivalent calculation scheme of a technical system consisting of a wheeled tractor as an energy propulsion and a trailer is given. Such theoreticalcalculative material is used in institutions of higher education of general and professional competencies of future specialists of agroindustrial production. It is noted that the preparation of future agricultural engineers for innovative project activities is carried out in accordance with industry standards and the Law of Ukraine “On Higher Education”. The influence of end-to-end project training on students’ readiness to perform scientific and practical tasks has been studied. The condition under which there will be no overloading of front wheels of the machine from its working bodies is substantiated, and ecologically admissible pressure on the ground will remain the same.
CONSERVING OF THE RESOURCES
To establish the effect of irrigation of raspberries grown in soil and meteorological conditions in the area of the village of Chelopechene – Sofia, studies were conducted in drip irrigation of plantations with remontant variety “Lyulin”, testing different regimes – from full satisfaction of daily needs of the culture from water to irrigation with reduced by 20% and 40% irrigation rates. A variant under non-irrigated conditions has also been tested.
When determining the effect of irrigation of raspberries by changing the yield compared to the non-irrigated variant, it was found that in the variant with 100% irrigation rate (optimal) the increase in raspberry yield reaches 59%, and in variants irrigated with reduced irrigation rates, the size yields increased by 54% and 47% respectively. It has been proven that the optimization of the moisture in the active soil layer contributes to a significant increase and stabilization of yields, which for the experimental conditions are from 835 to 1074 kg / dka and the additional yield varies from 404 to 627, kg / dka or from 47 up to 59% on average for the study period.
The established productivity of the irrigation water is the highest in the variants with 40% reduction of the optimal norm and changes during the years of the experiment from 13.0 kg.ha-1.mm-1 to 24.0 kg.ha-1 .mm-1. It is the lowest in the variants irrigated with 100% realization of the irrigation norm.
The dual-fuel combustion of ethanol and two different mixtures of ethanol and gasoline (E85 and E65) in a modified Diesel engine was investigated. With rising alcohol amount, a significant reduction of soot mass and particle count was observed at all operating points. At some load conditions, substituting diesel with ethanol, E65 or E85 led to a reduction of the NOx emissions, however, the real benefit concerning the nitrogen oxides was introduced by the mitigation of the soot-NOx trade-off, allowing higher EGR rates. With regard to the engine efficiency aspect, the results showed a bidirectional behaviour: at low load regimes engine efficiency degraded, whereas combustion became remarkably more efficient at higher engine loads. The measurements showed a high reduction of engine CO2 emissions in all cases, with the reduction being proportional to the alcoholic fuel energy share at the combustion. Ethanol sustainability is discussed based on the case study of an Austrian bio-ethanol producer.
This paper presents a theoretical model that allows estimating the state of tension in agricultural soil under the action of the wheels of a cultivator (two-wheel tractor), using the finite element method. Improper operation of cultivators and their improper use can lead to the degradation of agricultural soil by generating excessive mechanical stresses that favor the occurrence of artificial soil compaction. The finite element analysis models developed in this paper allow a dramatic reduction in the costs of experimental testing as well as the time required to estimate the possibility of artificial compaction of agricultural soil under the action of cultivators.