No 1 (2019)

Articles
Method of calculating the heat and stress-deformed state of the cylinder head of a transport diesel with liquid cooling
Gotz A.N., Klevtsov V.S.
Abstract
In an internal combustion engine (ICE), stresses arise from the action of a variable gas force and from a variable temperature due to the combustion of fuel in the combustion chamber in the cylinder head and piston, while the thermal stresses are much higher than the stresses from the power load. Therefore, at the design stage of a new engine design, they are calculating the durability of heat-stressed parts, since they limit the reliability of a piston engine. The paper discusses the method of selecting source data when calculating the thermal and stress-strain state of the cylinder head of a diesel engine using the finite element method and using the Solid Works software package. The stages of creating and preparing a solid model of a cylinder head to create a finite element model are described using the example of the 8ChN12 / 13 diesel engine (KAMAZ 740.75-440). The main loads acting on the cylinder head during the assembly period are considered: efforts from pressing in valve seats and bushings, as well as from tightening the bolts for fastening the head to the crankcase. The shape of the elements for the finite element model of the cylinder head was chosen from the condition of reducing the estimated time. This condition was suited to the shape of a finite element in the form of a tetrahedron with four nodal points. These elements made it possible to reduce the computational grid in cross sections, for example, stress concentration. It is shown that high-frequency temperature fluctuations that occur as a result of the flow of the working process of a piston engine do not affect the thermal strength of the cylinder head, and high-frequency temperature fluctuations due to changes in the engine operating conditions affect. The changes in the basic characteristics of the aluminum alloy from which the cylinder head is made with temperature and cyclic thermomechanical loading of low frequency are given. It is shown that with increasing temperature, the endurance limit of the material decreases at low frequency loads.
Izvestiya MGTU MAMI. 2019;(1):2-7
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Flow diagrams for tribological testing of transport engineering units
Glazunov D.V.
Abstract
Tests on full-scale units at the present level of development of transport engineering is not always appropriate due to their long duration, which is unacceptably delays the use of new lubricants. The development and use of model plants, stands and full-scale units allow for the shortest possible time to get a fairly reliable assessment of the most important performance properties of lubricants. The purpose of the study is to review the existing modern technological schemes of transport engineering on the example of rail transport units, allowing to study the processes of friction in lubrication conditions. The article describes five main schemes of possible tests: four-ball, Timken scheme, Falex scheme, Almen-Wieland scheme, SAE scheme. The classical and modernized technological schemes of tribotechnical testing of rail transport units used in our country and abroad, corresponding to the main test schemes are considered. Examined the device and principle of operation of the machine the four-ball friction CCT-1, the machine friction AI 5018, stand for tribological research on the basis of bench drilling machine, HC-12, the test stand simulating the operation modes of the system wheel - rail, developed by the Research and technology centre of the German Railways DBAG (FTZ) in cooperation with the companies Renk (Augsburg), and IABG (Ottobrunn). With the aim of improving existing technologies, the proposed test stand, wheel-rail tribosystem, allowing to simulate technology lubricatio grebnevsky systems on the railway transport. Technological feature of this stand is that the model of the wheel flange makes a small vertical and horizontal return movement that mimics the natural movement of the wheel flange during the movement of rolling stock during the application of the lubricant.
Izvestiya MGTU MAMI. 2019;(1):8-16
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Study of the balancing method of the charging station for lithium-ion batteries
Zuev S.M., Aleksyuk M.R., Kanarejkin A.I., Habarova S.D., Bogachev S.A.
Abstract
This article discusses the problem of balancing the configuration of 4S lithium-ion batteries in the charging process and the method of solving it using a new type of charging station. As a working sample, a 4-cell "smart" battery pack was used. The advantages of using the passive balancing method compared to the active one are shown. Designed by a team of authors, the BMS battery management system layout allows you to control the physical parameters on the battery cells and to perform balancing, increasing the battery life and safety. The BMS battery management system allows you to control the parameters of a rechargeable cell or battery, protecting them from working in a hazardous area, as well as reading background data through the built-in control and analysis system based on the ATmega328 microcontroller. The control system can monitor the state of the battery, which is represented by various parameters, such as voltage, temperature, SOC charge state, "health state" SOH, current. Batteries with an arbitrary number of series and parallel-series cells of a battery can be examined. During the research, graphical dependencies of the charge of the battery cells were obtained without using the BMS system and using this system, this allowed to analyze the technical characteristics of the battery and further develop proposals for their safe operation modes. The use of the proposed BMS system to increase the service life of lithium-ion batteries is possible in many areas of production. Due to the large distribution of lithium-ion batteries from consumer electronics to vehicles, this development is relevant in the framework of modern electrical technology.
Izvestiya MGTU MAMI. 2019;(1):17-23
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Comparative analysis of the options for strengthening the cockpit of the D2 class buggy according to the technical regulations of the competition
Bazhenov E.E., Bujnachev S.K., Kustovskij A.N.
Abstract
The article presents a comparative analysis of various options for strengthening the cockpit of a typical frame of the D2 class buggy for the twisting mode around the longitudinal axis. Criteria for assessing options are hard - weighted indicators. The spatial frame of the buggy is exposed to a variety of loads and their combinations. The impact of external forces causes a complex-stressed state in the carrier system, characterized by both simultaneous and alternate effects of bending and twisting forces. All this can lead to such deformations and displacements of the frame elements, that the assemblies and units fixed on it can experience various malfunctions in work, and even completely fail (the steering rack mounted on the frame is very sensitive to deformations, the differentials in their attachment points to frame due to its deformations can be damaged, as well as gas tank fasteners, and the driver's seat, etc.). Thus, it becomes obvious the importance of giving the frame of the buggy the necessary rigidity to resist operational loads. In addition, the lack of rigidity leads to increased stresses in the frame under different loading conditions. It is needed not to forget about the characteristics of controllability, which is directly influenced by the geometric stability of the carrier system. All this proves the importance of ensuring the rigidity of the buggy carrier system. In addition to a comparative analysis of cockpit enhancement options, a number of practical recommendations for the considered options will also be given. According to the results of a comparative analysis of options, it is possible to establish the dominant role of strengthening the cockpit roof as an option that provides not only the highest torsional rigidity, but also the lowest weight. All options are consistent with the requirements of the technical regulations of the competition (Appendix J, Article 253).
Izvestiya MGTU MAMI. 2019;(1):24-28
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Study of the modes of operation of capacitive energy storage in the automobile engine start systems
Maleev R.A., Zuev S.M., Lavrikov A.A., Grebenchikov N.P.
Abstract
The article presents data on the study of the operating modes of capacitive energy storage (ES) in the start systems of a modern automobile engine. Experimental dependencies of the main parameters of the electric starter start systems (SSS) using ES are presented. A comparative analysis of alternative energy storage devices revealed that the best performance indicators for specific power are ES, which is achieved due to lower internal resistance. ES are able to quickly give away and accumulate energy. The discharge and charge time is determined by the electricity consumers and the parameters of the charging circuit of ES. Studies of ES in SSS for automotive internal combustion engines (ICE) were carried out, when, instead of the standard battery the battery with a smaller capacity is used, and the ES is located in the remaining part of the volume of battery. At high specific rates of ES, the reliability of the start can be increased with the same total volume and weight of the SSS at low temperatures. The theoretical and experimental studies have allowed to obtain the dependence of the instantaneous and average parameters of the SSS on the time of the engine scrolling, as a result of which the required capacity of the ES and its internal resistance, the initial energy of the ES, as well as the necessary volume and mass of the ES are determined. The volume and mass of batteries can be determined from the reference literature or by known methods by specific energies of batteries in volume and mass. On the experimental dependences it was shown that the time of the crankshaft scrolling, the number of working strokes and the angle of rotation of the crankshaft to a complete stop Nрх depend on the capacity and charge voltage of the ES. The studies were conducted in the Cold Start Laboratory of the Federal State Unitary Enterprise Research and Experimental Institute of Automobile Electronics and Electrical Equipment together with the Department “Electrical Equipment and Industrial Electronics” of Moscow Polytechnic University, where an experimental assessment of the possibility was made of starting gasoline engines at low temperatures of SSS with ES of high-voltage (capacitors with a voltage of 200 V - 290 V) and low-voltage ESs with a voltage of 12 V - 16 V.
Izvestiya MGTU MAMI. 2019;(1):29-35
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Agricultural tractors on Russian market (based on the International exhibition “Agrosalon 2018”)
Parfenov A.P.
Abstract
The review of an exposition of the agricultural tractors presented at the international exhibition "Agrosalon 2018" which was taking place in Moscow from October 9 to October 12 is provided. Along with domestic manufacturers and the CIS countries: Petersburg Tractor Plant, the Rostselmash, the Bryansk tractor plant, the Minsk tractor plant), the products were exhibited and advertized by also leading global manufacturers of agricultural tractors: AGCO (USA) (Fendt, Challenger, Massey Ferguson, Valtra), Deere & Co (USA), Case New Holland (CNH) (USA). CLAAS (Germany). The Market of agricultural tractors of the Russian Federation is in a quantitative sense comparable to the markets of leaders of the European Union countries: Italy, Germany, France. The available qualitative differences are explained by features of agricultural production, the sizes of the agricultural enterprises and their infrastructure, a ratio in the park wheels and caterpillars tractors, solvent demand and other factors. In formation of the market of tractors the following directions gain development: accent shift towards tractors of high power with simultaneous strengthening of positions of tractors with driving wheels of the identical size (4k4b), special attention to caterpillars which are offered in options: traditional - two-caterpillar and nonconventional - four-caterpillar at which driving wheels of tractor 4k4b are replaced with the modules of triangular shape supplied with rubber-reinforced tracks .The following feature of the domestic market of tractors is existence of the real competition in segments: powerful tractors 4k4b, universal tractors of average power and also caterpillars of high power that is defined by a variety of offers and openness of the market of the agricultural equipment. The feature of the market is its heterogeneity on technological level of the offered machines that is explained first of all by different purchasing power of buyers. Studying of exhibits shows that the trends of development of designs of tractors, their units and systems noted by us when studying exhibitions "Agrosalon 2014" and "Agrosalon 2016" keep the actuality. Keeps actuality also a question what has to be the mass caterpillar tractor for agricultural production of the Russian Federation.
Izvestiya MGTU MAMI. 2019;(1):36-45
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Selection of parameters of a three-flow parallel electromechanical transmission of a tracked vehicle
Padalkin B.V., Staduhin A.A.
Abstract
One of the serious shortcomings of electromechanical transmissions, restraining their widespread use on tracked vehicles, is the large weight of electric motors and energy storage devices. The article provides a three-flow transmission scheme with the minimum number of electric machines necessary to ensure stepless acceleration and rotation with the obligatory use of an internal combustion engine and electric drive. Reducing the number of electric machines is achieved by using the same machines as traction motors and generators, depending on the mode of operation. This implies that when driving at speeds below average, electric machines should work as a generator, above average - as a traction motor. Transmission allows movement without the use of electric machines, but with reduced performance. The article discusses five modes of transmission, the specific traction and power characteristics for these modes. The features of the use of short-term and long-term characteristics of electric machines in the engine mode are taken into account. The use of the internal combustion engine is substantiated not only in the nominal mode, but also in the maximum power mode. A method for selecting transmission ratios, characteristics of the internal combustion engine and electric machines is presented and justified. The calculation is made for the track conveyor of the ultra-light mass category. A description of the regenerative braking modes available for transmission, as well as a description of the mode of charging the drive when parked are given. The scientific problems of evaluating the efficiency of the transmission, the need to study the rotation of the tracked vehicle where it is installed, the development of top-level algorithms for its control are indicated.
Izvestiya MGTU MAMI. 2019;(1):46-52
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Substantiation of the requirements for the suspension of unmanned transport vehicles
Sarach E.B., Smirnov I.A., Tkachev Y.A.
Abstract
Currently, there is a proliferation of vehicles in which the presence of a driver or crew is not provided. They are controlled remotely or are able to move independently. These vehicles belong to the class of unmanned. Analysis of the development stages of the chassis for the traditional crew machine shows that the basic requirements for suspension systems are that the vertical accelerations acting on the driver and crew should not exceed certain values. However, for unmanned vehicles, these requirements are not applicable due to the absence of people in the vehicle body. Considering that unmanned vehicles must move in the same conditions as traditional ones, including cross-country terrain, in some cases along harmonic tracks, there is an urgent task to develop special requirements, which should be taken into account when designing chassis for unmanned vehicles as a separate class of transport equipment. The article proposes to consider some approaches to the definition of such requirements. In particular, when changing the load on the undercarriage elements, it is proposed to proceed from the condition that the vehicle should provide the possibility of transporting the payload, which is usually indicated in the terms of reference. In accordance with this statement, the necessity of studying the most loaded suspension elements is justified, as a result of which it is possible to predict the mass characteristics of the designed chassis. This paper identifies key problems and suggests some ways to solve them. Based on the above material, some conclusions have been made that can be used in further work in solving practical problems in this area.
Izvestiya MGTU MAMI. 2019;(1):53-59
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Development of multicomponent mixed bio-hydrocarbon fuel for diesel engines
Soo S., Sater H.A., Hodyakov A.A., Hlopkov S.V.
Abstract
The density, viscosity, cetane number of mixtures of diesel fuel (DF) with peanut butter (PB) are determined. For the preparation of mixtures the summer-type diesel fuel, unrefined peanut oil (TU 9141-001-0062499777-2016), kerosene (KO-25 TU 38.401-58-10-01) were used. The criteria for the applicability of peanut oil as a component of fuel were density (r), viscosity (u), cetane number (CN) of diesel fuel. It is established that r, u, CN of mixtures with a peanut butter content of not more than 20% are identical to the parameters r, u, CN of diesel fuel. The activation energy of the viscous flow (Еа) of mixtures and peanut butter was estimated. It is shown that the parameter Еа is much lower than the activation energy of the oxidation process occurring when PB is heated. It was concluded that viscosity measurements (in the temperature range from 20 to 1000 ° C) are not affected by oxidative processes. The cetane numbers of the objects of study were measured by the indicator CN OKTAN-IM. It is shown that the cetane numbers of mixtures containing more than 50% PB are lower than the minimum value necessary for the normal operation of the engine when it is powered by diesel fuel. A list of the disadvantages of composite diesel fuel is presented, and a method is given to compensate these shortcomings, which consists in introducing kerosene into this mixture. It is shown that a multicomponent mixture satisfying the requirement for r, u, CN values of diesel fuel should contain 33% kerosene, 29% diesel fuel and 38% peanut butter. It is noted that for the final conclusion on the applicability of this mixture full-scale tests are required.
Izvestiya MGTU MAMI. 2019;(1):60-66
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Improving the energy efficiency of vehicle electrical systems
CHernov A.E., Akimov A.V.
Abstract
The article discusses the main directions of improving the efficiency of electrical systems (EES) and power supply systems (PSS) of motor vehicles (MV) of traditional design, using internal combustion engines (ICE) for movement, the main trends in the development of MV. There are shown technical solutions aimed at reducing fuel consumption. The analysis of the current PSS, indicating its main shortcomings is given. It is shown that increasing the maximum output current of the generator set to 20 A leads to an increase in engine fuel consumption by 10-15%. Fuel consumption for the drive of the generator set on modern vehicles with gasoline engines reaches 20% of the total fuel consumption in the city. A method of simulation of EES in operation and analysis of the concept of power supply system management, aimed at reducing fuel consumption, is given. The main ways of increasing the efficiency of EES using the developed voltage regulator built into the control panel SCHU-5 are given. The advantage of the developed voltage regulator is a significant expansion of diagnostic functions. This is an indication of the increased voltage of the network, since the operation of the fuel injection system control unit already at a voltage of 17.5 V leads to its failure, and the cost of this unit is more than 9,000 rubles, which is significantly higher than the cost of the voltage regulator. Multi-function voltage regulator has the function of controlling the growth of the load. This function ensures the stable operation of the engine in the mode of forced idling and eliminates shock loads on the generator drive belt. The circuit voltage regulator has short-circuit protection in the circuit control lamp. In the multifunctional voltage regulator, thermal protection is introduced, which increases the reliability of the generator set operation in severe operating conditions at elevated ambient temperatures.
Izvestiya MGTU MAMI. 2019;(1):67-76
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Improvement of four-wheel drive vehicle controllability with a connected front axle through the redistribution of torque
ZHilejkin M.M., EHranosyan A.V.
Abstract
Currently, manufacturers of modern cars are constantly increasing the level of control over the parameters of the movement of wheeled vehicles, achieving the maximum level of stability and control. The use of various all-wheel drive systems is becoming increasingly relevant and expedient. The distribution of traction force on all wheels allows you to use the entire weight of the car as a coupling, which has a positive effect on the dynamic qualities of the car, terrain, and allows you to implement control algorithms that improve the handling and directional stability of the car. This article discusses the transmission with the possibility of redistribution of torque between both the front and rear axles, and between the wheels of the rear axle. The aim of the work is to substantiate the methods of control of the curvilinear motion of two-axle cars with different transmission schemes, providing an increase in their controllability. The control algorithms for the demolition of the front axle (understeer) and the rear axle skidding (oversteer) are considered. To solve the problem, the frequency method is used, in which the wheeled vehicle is considered as a multidimensional system. As a result, a method was proposed for improving the controllability of a two-axle car 4x4 with a link to the front axle and the redistribution of the torque between the wheels of the rear axle due to the redistribution of torque. The effectiveness and efficiency of the proposed method are proved by the methods of simulation of motion of two-axle 4x4 vehicles with a connected front axle and redistribution of torque between the wheels of the rear axle.
Izvestiya MGTU MAMI. 2019;(1):77-84
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