Increasing the Flow Capacity of Hoses with Electrical-Heater Coils to Supply Thickened Preservatives for Spraying

Introduction. Anticorrosion protection of agricultural machinery working elements is provided through using pneumatic application of thickened preservatives with heating. For this purpose, a wire coil is inserted inside the preservative-supply hose and connected to a current source. It is known that the wire thickness and the coil pitch affect the hydraulic resistance to fluid flow. However, it has not been established how the diameter of the coil insert and its heating affect the flow capacity of the flexible hose channel. The purpose of the research is to increase the capacity of a flexible hose with an electrical-heater coil. For this purpose, it is necessary to determine its geometric parameters minimizing the hydraulic resistance to the thickened preservative flow and reducing the energy consumption for heating the material in the hose. Materials and Methods. It is proposed to investigate two electrical-heater coils of the same length, but of different diameter, made of steel welding wire pieces of equal length. There was developed a stand to study the influence of the inserted coil parameters on the hose hydraulic resistance. The stand was used to determine pressure losses in hoses with coils and in smooth hoses when used engine oil and thickened preservative flow through them. The flow capacity of the hose with cold and heated coils was estimated. Results. The method of heating the preservative in the hose wall layer is justified. At the same time, its flow capacity increases one and a half times with less energy consumption (2.4 times) than when heating the preservative in the central part of the hose. Under laminar flow mode, the pressure loss in the hose is 2 times lower when the coil is equal to 0.85 of the hose channel diameter than when the coil is equal to 0.67 of the channel diameter. Discussion and Conclusion. The research found the rational way of placing the electrical coil near the heated hose channel wall. At low air temperature, the reduction of the thickened preservative viscosity by heating in the hose helps to decrease the pressure loss up to 50% and increase its flow capacity by 1.4‒2.0 times. The use of a electrical-heater coil in the hose with thickened preservative will minimize energy consumption when preserving equipment on open storage sites.

The Digital Twin for Agricultural Machinery Restoration Processes

Introduction. Agricultural machinery provides the required level of mechanization. Sand abrasive, dirt, and open-air operations considerably accelerate the wear of mechanisms. An improper work plan and lack of complete information about the state of specific equipment units increase the time for repair and maintenance operations. The purpose of the study is to develop a digital twin model for the repair and restoration system of enterprises. The model will reduce material costs and allow for the best solutions to organize the work. Materials and Methods. The model is developed on the basis of simulation modeling. The authors used the approach based on discrete-event modeling with the logical-mathematical apparatus for describing events occurring in a real object. Results. Information support is formed taking into account the parameters of the production systems of repair enterprises and a mathematical model, which is a digital twin of the production system. This approach made it possible to automate the development of optimal plans for organizing repair work by repair enterprises, taking into account their interrelationships. Discussion and Conclusion. The digital twin for the generalized production system of repair organizations allows developing options for the resource allocation and verifying them promptly to choose the best options through accumulating information about the most successful solutions. This will reduce the time for repair and restoration works, improve their quality and save labor.

The Use of Surfacing Materials to Increase the Durability of Disc Harrow Working Elements

Introduction. For surface tillage operation there widely used disc harrows, working bodies of which are discs wearing out during operation. The wear intensity of discs depends on the wear resistance of their working surfaces, working modes and properties of the cultivated soil. It has been found that an effective way to increase the life of discs is surfacing them with wear-resistant materials. The aim of the work is to study the wear out of surfacing materials, which can be used to harden discs and to make recommendation for the use of these materials in the repair departments of agricultural enterprises. Materials and Methods. Surfacing with electrodes T-590 and powder wires PP-Np200Kh15S1GRT, VELTEK-N560.02 and PP-Np280Kh9F7SG4 were taken as test materials. For wear tests of materials in abrasive mass, there was used an apparatus to simulate the moisture content and composition (sandy loam or loam) of the soil. In the disk-pad tests, the effect of abrasive particle size, load and sliding friction velocity on the wear of the materials was studied. In field tests, wear of the disks made of 65G steel, surfaced toothed and solid disks were monitored. Results. Laboratory studies of the materials revealed the effect of soil moisture and composition, load, abrasive grit and sliding friction velocity on wear. The main factor determining the wear resistance of materials is their structural state. The indexes of wear resistance of surfacing were determined during the laboratory tests and confirmed by field tests. Discussion and Conclusion. Surfacing with flux-cored wire PP-Np280Kh9F7SG4 has the highest wear resistance of the studied materials. The technology of hard-facing disks with modern materials, in particular with flux-cored wire PP-Np280Kh9F7SG4, can be implemented in repair departments of agricultural enterprises when they have the equipment for hard-facing and sharpening of working surfaces.

Integrated Mobile Robotic Platform Model

Introduction. The “Smart Agroˮ committee of Research and Education Center “Engineering of the Future” has identified a number of tasks relevant for improving the efficiency of precision, soil-protecting and conservation agriculture. One of these tasks is the development of a digital multi-agent system, which provides a number of services for agricultural enterprises, developers and manufacturers of agricultural machinery. The purpose of the present study is to model an autonomous mobile robotic platform, including the development of software and hardware for trajectory control. Materials and Methods. To solve the problem, there are used modern CAx systems and their applications, the methods of 3D and full-body modeling, and the method of numerical solution of problems in solid mechanics. To expand and improve the standard functionality of CAx-systems (SolidWorks) in the software implementation of trajectory control algorithms, the methods and technologies of programming using API SolidWorks, VisualStudio C++ (MFC, ATL, COM) are used, and to build physical full-scale models ‒ Arduino and fischertechnik platforms. Results. The result of the study is a software and hardware module of trajectory control for an integrated (physical and virtual) model of a mobile robotic platform, which can be provided to the consumer as a service for technology autonomation. For the developed integrated model, control algorithms for various types of trajectories were tested. Discussion and Conclusion. The developed integrated software and hardware model of trajectory control can be used by developers and manufacturers of agricultural machinery, and directly by agro-enterprises for implementing typical technological processes. A feature of the implementation is an open hardware and software interface that provides the integration of mobile robotic platforms based on a digital multi-agent system.

Experimental Determination of the Influence of the Peeling Machine Constructive and Operating Parameters on the Criteria of the Peeling Process Efficiency

Introduction. The determination of the optimal technological efficiency of the peeling process, in terms of the number of detached casings and unit costs of the process, is an important task. The purpose of the study is to give reasons for a comprehensive evaluation criterion of the technological efficiency of peeling wheat grain and choose the optimal values of the parameters of grain peeling, taking into account the energy intensity of the process. Materials and Methods. To quantify the technological efficiency of peeling wheat grain, we used the following local efficiency criteria: the relative yield of peeling by-products, the relative decrease in grain ash content, the increase in the number of cracked grains, and a comprehensive criterion of efficiency taking into account local criteria and the specific power consumption. Results. The experiments have shown that the technological feasibility of the peeling process is ensured at the percentage of the flap opening at the outlet of the machine 60‒70%. In this case, the relative yield of waste husk is 3.2‒2.8%, the relative decrease in grain ash content is 0.32‒0.20%, and the increase in the number of cracked grains does not exceed 0.85%. With increasing the degree of the flap opening at the outlet of the machine from 50 to 100%, the specific power consumption decreases from 8.7 to 3.5 kW∙h/t. Discussion and Сonclusion. To assess the technological efficiency of wheat grain peeling a generalized efficiency criterion, which includes local criteria, is proposed. It has been experimentally proved their dependence on the intensity of grain processing in the machine. The optimum combination of the flap opening degree at the outlet of the machine at 67% (productivity 0.7 t/h) and the specific power consumption of 5.8 kW∙h/t was defined. In this case, the efficiency complex criterion, taking into account the process energy intensity of, is 4.5 kg/kW∙h.

Experimental Data of Grinding Dried Fibrous Plant Materials

Introduction. Developing a method for energy-efficient grinding of fibrous vegetable raw materials to avoid the clogging of grids remains an urgent task. The aim of the research is to study the process of grinding dried fibrous plant materials and to estimate the influence of the device operating characteristics on the quality of grinding and the process energy intensity. Materials and Methods. The experimental apparatus is a rotor grinder. Its working bodies are alternate knives and hammers. When a hammer is in motion, its triangle side creates the reduced pressure area. There was studied the influence of the linear velocities of knife motion and of feed of raw materials on fractional composition of the grinded materials, grinder productivity, and grinding specific energy capacity. Results. It is found that the change in the fractional composition of the grinded product occurs when the speed of the rotor knives increases. Optimal range of knife speed for producing the product of the required fractional composition is 55‒75 m/s. The increase in the speed leads to increasing productivity, but is accompanied by the growth of specific power intensity. If the rotor speed is constant, the increase of raw material feed increases the grinder productivity, but only up to a certain value. After that, the productivity decreases because of excessive filling of the working chamber with raw materials and clogging of the grates. For each value of the knife speed, there is an optimal feed that ensures the maximum productivity. High values of knife speed lead to significant energy intensity of the process and overgrinding of raw materials. Therefore, the optimal range of knife speed is 55‒65 m/s. Discussion and Conclusion. Effective grinding of raw materials is achieved through lower energy capacity of grinding process and absence of grate clogs resulted from separating particles from the surface of plants to be grinded.

Features of Machining Rotor Shafts of Diesel Engine Turbochargers with a Multilayer-Coated Tool

Introduction. The paper presents the results of experimental studies of power parameters when hard alloy steels are machined with tools, the cutting units of which have multilayer hard, heat-resistant and wear-resistant coatings. The obtained data will make it possible to optimize machining hard-to-machine materials. Materials and Methods. The aim of the study is to measure the power parameters of turning products and to create experimental formulas of power parameters for different technological modes. For this purpose, a special measuring multicomponent complex was used to estimate the influence of the mode parameters on the change in the cutting force components. Results. The numerically controlled machine tool was retooled by combining it with a three-component dynamometer and tooling. The cutting unit of the tool was coated with a multi-layer hard, heat-resistant and wear-resistant coating. The tool was equipped with instruments connected to a personal computer for measuring and processing experimental data. According to the results of the study, there have been obtained graphical dependences and empirical formulas, which take into account the influence of the mode parameters on the cutting force components when machining the units of alloy steels of high hardness, heat resistance and wear resistance. Discussion and Conclusion.The study allowed us to obtain experimental formulas of cutting force components for different mode parameters when machining parts by the tool equipped with cutting plates. The plates are coated with multilayer hard and wear-resistant coatings of titanium carbonitride, aluminum oxide and nickel nitride. The coating increases significantly the hardness, heat and wears resistance of the tool cutting unit and provides quality machining.

Developing the Test Bench Software for the Technical Inspection of Volumetric Hydraulic Drives

Introduction. The article describes the test bench specialized software, developed for technical inspection of domestic and foreign volumetric hydraulic drives in repair enterprises and service centers. The results of bench tests using a hydraulic bench and software are presented. Materials and Methods For the application software development, G graphical programming language of the Laboratory Virtual Instrumentation Engineering Workbench (Lab- View) programming environment developed by the National Instruments Company has been used. The reliability of the results obtained has been confirmed by a series of bench tests of domestic and foreign volumetric hydraulic drives. Results. There has been developed and implemented new test bench software for the technical inspection of hydraulic drives of different models from domestic and foreign manufacturers in repair plants and service centers. The software is used to capture, process and store data from the sensors during testing, to calculate and output measurement data, to conduct nonlaboratory analysis of the testing process in graphical, textual and video formats, to calibrate sensors, and to store the test results in the electronic library system. The specialized software runs under the Microsoft Windows 7 x86 (32-bit) operating system and is installed on a personal computer of the hydraulic bench data processing unit. The developed software is characterized by the ergonomics of the user interface, the ability to control all the parameters of diagnosing the tested volumetric hydraulic drives. Discussion and Conclusion. Specialized software and the test bench permit high accurate monitoring of all technical condition parameters of the most common domestic and foreign volumetric hydraulic drives in accordance with the requirements of the manufacturers in the repair enterprises and service centers.

Evaluation of Combustion Performance and Heat Release in Preheated Fuel Consumed Diesel Engines

Introduction. The expansion of the fleet of tractors and vehicles causes increased requirements for internal combustion engines. This problem can be solved by improving the work process in a diesel engine that can be achieved by heating the diesel fuel in the fuel supply system. External thermal action is carried out on the high pressure line directly in front of the injectors. Materials and Methods. To analyze and calculate the process of combustion and heat release in a diesel engine with preliminary thermal fuel preparation, bench tests were carried out using the National Instruments software and the necessary equipment. Results. Experimental data of the diesel fuel combustion process in the cylinder of the 4CHN 11.0/12.5 engine are obtained. The analysis of the combustion performance and heat release of diesel with a preliminary high-temperature effect on the fuel was carried out. Indicator diagrams, graphs of heat release, the maximum average temperature of gases in the engine cylinder, and graphs of active and total heat release were constructed. The experimental data showed a decrease in the ignition delay period, the maximum cycle temperature in the engine cylinders, and an acceleration of the start of heat release and combustion process. The values of the parameters of the diesel fuel combustion process are obtained. Discussion and Conclusion. On the basis of the conducted studies, the dependences of the parameters of the combustion process of a diesel engine with fuel heating to high temperatures are revealed. Indicator diagrams allow drawing a conclusion about the influence of the fuel heating temperature on the intensification of the combustion process. There is an acceleration of the beginning of heat release, a decrease in the rate of pressure build-up and in the rigidity of the engine.

Estimation of the Elasticity Modulus of Composite Electroplated Coatings during Their Layer-by-Layer Deposition

Introduction. To keep automobiles and tractors in operation conditions, it is necessary to restore the inner cylindrical surfaces of the friction pair parts. This is the most laborintensive activity. The method of electroplated contact deposition of composite coatings, based on elastic plastic deformation of formed layers, is used for repairing surfaces. To use this method it is necessary to determine the values of the elasticity modulus, on which the wear resistance of tribocouplings depends. Materials and Methods. For the study, cylindrical samples made of 30 HGSA and 30 HGSNA steels were used. Electrolyte containing 200–250 g/l chromium oxide, 2.0–2.5 g/l sulfuric acid, and distilled water was used for electroplating the coatings. When calculating the stress-strain state, the apparatus of continuum mechanics was used. Results. The dependence of the coating pliability as a function of the parameters of individual elementary layers is determined. When the multilayer coating of three types (orthogonal-reinforced, cross-reinforced and quasi-isotropic) is applied, its structure does not depend on the angles of kinematic tool movement on the inner cylindrical surface of the part. For each type of coatings, the way to determine the constant stiffness coefficients of the layers is specified. The dependences for calculating the elasticity modulus of the applied material are derived from the values of the stiffness coefficients. Discussion and Conclusion. In determining the modulus of elasticity of multilayered composite coatings, the calculation is made for the individual layers by passing to the convective coordinates, which is in complete agreement with the Lagrange point of view on the study of the motion of a continuous medium. The results obtained are of practical significance in the selection of the coating material to be applied for the restoration of internal cylindrical surfaces.