International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Cleaning of root and tuber crops, in particular potato tubers, from soil impurities and plant residues when they are excavated from the soil is an important and urgent problem in the agricultural industry. This article discusses a new construction of a vibrating spiral root and tuber cleaner and a new experimental setup that makes it possible to study the influence of the main structural and kinematic factors on the operation of a spiral type cleaner, as well as to substantiate its rational structural and kinematic parameters. The main constructional difference of the developed cleaner is that the technological process of cleaning root and tuber crops from soil and plant impurities is carried out by moving the heap with coils of cantilevered spiral springs rotating at a certain angular speed and forced oscillatory movements of the ends of the spiral springs themselves in the longitudinal-vertical plane. In this case, soil and plant impurities are effectively sifted not only through the separating gaps and coils of the spirals, but are also significantly destroyed due to oscillatory movements. At the same time, the root and tuber bodies are guaranteed to be transported by the spiral coils themselves towards the unloading conveyor. In the case of covering the spiral coils with a rubber coating, there is no damage to the bodies of root and tuberous crops. The article also presents the developed methodology for conducting a multifactorial experiment on cleaning root and tuber crops from soil impurities and plant residues.

In this paper the deformation force of the forging process in step-wedge strikers was studied. At the first stage, the study of the deformation force using computer modeling in the Deform-3D software package was carried out. At the second stage, an experimental study of the deformation force during the broaching of workpieces in step-wedge strikers using thermometry was carried out. It is established that the experimental results have a high convergence with the simulation values. The increasing level of difference in results is associated with heat losses during intermediate operations, which are usually ignored during modeling.

This work is devoted to the study of the use of radial-shear rolling mills for recycling bar scrap and some metal products from ferrous and non-ferrous metals that have served their service life to obtain a ready-made commercial product. In particular, the paper presents the results of computer modeling and experimental research of the process of scrap metal rolling in the form of rebar on a radialshear rolling mill into a round cross-section bar, which prove that some metal products that have served their service life after recycling using the proposed technology into finished commercial products in the form of bars can find further use without remelting.

Global demand for electric energy is predicted to increase in the coming decades. Following this, different approaches for additional electricity production are analysed and tested worldwide. The EU supports the production and usage of electricity from renewable energy sources, particularly wind energy, because it provides electricity without giving rise to any carbon dioxide emissions. The presented work analysis the possibility for utilising of wind-generated electricity as a stand-alone system for small off grid cabin supply. The very basic turbine geometry was designed and numerically simulated with commercial CFD software. After that, the turbine model was printed using 3D printer and tested in laboratory environment. The comparison of numerically and experimentally obtained operating characteristics show reasonable agreement and strong potential for system optimisation and improvements.

The increasing water deficit requires studies to optimize irrigation regimes and water-saving technologies to achieve economy of irrigation water at an acceptable yield level.
In order to establish the irrigation regime in the field of “Chelopechene” Experimental Field, Sofia, there have been researches, examining different regimes – from full satisfaction of the daily needs of culture for water to irrigation with reduced by 20% and 40% water application rates.
On average, over the survey period, the highest yields were obtained with the irrigated wit 100% water applicatipn rate. Reducing the irrigation rate leads to a corresponding reduction in yields and affects the quality of production. The application of regimes of irrigation with reduced iwater applicatipn rates is recommended  only in the case of water deficiency.

The object of the study is an ultrasonic sensor type UT2F/E7-OEUL which measures the presence of a body in the range of 350 to 6000 mm. The sensor was mounted in a suitable place in the combine harvester. Experiments were conducted on three types of waste vegetation mass (WVM): wheat, beans and alfalfa in field and laboratory conditions. A database of sensor measurements was obtained. A single-factor dispersion analysis task was formulated. The results obtained using relevant specialized software showed that the sensor is operational regardless of the type of WVM.

Production planning and control (PPC) system represents a set of decisions on the acquisition, utilization and allocation of resources with the ultimate goal to satisfy customer requirements in the most effective and efficient way. PPC system involves a considerable amount of parameters and synchronizing of a high number of components is a complex process, especially in present business environment where everything has to be decided fast and precisely under an enormous pressure of external factor that undergo through constant change, as so throughout the years a number of methods have been developed with the intention of optimizing the work of PPC systems. One of the methods for optimizing PPC systems which is also used in this case is simulation module for PPC which integrates the parameters involved offering the opportunity of experimenting and analyzing the different possible scenarios in order to find the one that delivers the best possible results without affecting the current actual system and with that reducing the cost and time needed to identify the most optimal solution.

In this paper we have presented methodology for development of life prediction model for first order tool during turning of hardened 42CrMo4 steel at different levels of hardness. It is important to be able to predict and describe the tool life in regards to manufacturing costs during industrial production. Tool life is defined as the of cutting time that tool can be used. Cutting tools can be used when they do not reach tool life criteria and can produce parts with desired surface finish and dimensional accuracy. Flank wear of cutting tools is often selected as the tool life criterion because it determines the diametric accuracy of machining, its stability and reliability. Tool wear is defined as a gradual loss of tool material at contact zones of workpiece and tool material, resulting the cutting tool to reach its life limit. This paper investigates the tool wear of TiN coated tungsten carbide inserts under dry cutting, using the central composite design of experiments method (DoE) with three factors at three levels. By using the multiple linear regression analysis between cutting speed, feed rate and depth of cut, it determines the effects of cutting conditions on extended Taylor’s tool life equation.

A modified flow line for eggs sorting by geometric parameters and forms is discussed in the paper. A method for eggs sorting by shape factor allowing to remove sub-standard eggs is proposed. Also the algorithm for determining the geometric parameters of the eggs using a vision system is considered. The fundamental difference of experimental installation for automatic eggs sorting on the category from existing sorting machines, that share eggs on a category by weight, is separation of eggs on a categories by size and separation substandard eggs in the stream. In the experimental installation mechanism for moving the eggs dismantled and replaced to an endless rope transporter with independent frequency-controlled electric drive. As a result of the experimental verification of system parameters of technical vision on the experimental installation showed that the time required for classification of the eggs is not more than 340 ms.