Journal of Mechanical Engineering and Transport

Study of the influence of honing process parameters with silicate bars on the quality of the treated surface

2024-07-09T10:02:13+03:00

Numerous studies have shown that the kinematics of the honing process, which determines the trajectory of the cutting grain during machining, has a major impact on the parameters of macro- and microrelief. The complex working movement during honing of holes creates favourable conditions for the fuller use of the cutting capacity of the bars and uniform wear of the tool, which positively affects the machining performance and accuracy of the geometric shape of the surface. It is shown that, in this regard, there is a need to investigate the influence of the parameters of the honing process with silicate bars on the quality of the machined surface.

The paper presents the results of a study of the effect of the contact pressure of the bars and the axial and circumferential speeds on the quality of the treated surface. The study was performed on a vertical single-spindle honing machine. The samples used were cylinder liners of car engines made of grey alloy cast iron. The evaluation was based on the roughness of the machined surface and the mass removal of metal during machining. The best performance was achieved by those bars that resulted in the lowest roughness of the samples.

It was found that with an increase in the circumferential speed, the surface quality improves, and with an increase in the axial speed, it deteriorates after processing with diamond, abrasive and silicate stones. With an increase in the contact pressure of the bars, the surface quality deteriorates after machining with diamond bars and improves after machining with abrasive and silicate bars.

It has been proven that the high surface quality after treatment with silicate blocks is due to the formation of amorphous silica during honing, which, under the influence of abrasive grains, falls into the cavities of the treated surface and adheres to the surface, thus saturating the treated surface with silicon oxide.

It has been established that with an increase in the axial speed of the bars, metal removal increases, and with an increase in the circumferential speed, it decreases after machining with diamond, abrasive and silicate bars. With an increase in the contact pressure of the stones, metal removal increases after machining with diamond stones and gradually decreases after honing with abrasive and silicate stones.

It was found that the metal removal after machining with silicate stones is 2 times less than after honing with diamond stones.

It is proposed to set the allowance for finishing honing with silicate stones for cylinder liners made of alloy cast iron (HB 240) within 0.01-0.02 mm.

Improvement of the method of assessment of software for the control of vehicle parameters

2024-07-09T11:21:17+03:00

The purpose of the conducted research is to improve the method of evaluating the performance of the vehicle parameter control software. It is stated that a new technique for road transport in the field of monitoring its working condition is the creation of information systems for organizational and functional support of rolling stock operation processes with the help of information integration, namely the stages of the life cycle of rolling stock and systems for its technical control and diagnostics. It is shown that nowadays in road transport the basis of life cycle information support can be CALS or IPV/CALS/PLM - technologies (continuous support of the life cycle of vehicles), which are sometimes called product information support systems and are a part of intelligent transport systems. The analysis and clarification of the structure of the intelligent vehicle monitoring system was carried out on the example of the assessment of its environmental safety and its engine parameters. In the work, it is also planned to obtain experimental data from vehicle, the results of processing of which will allow to prove the existence of a real possibility of using the diagnostic complex on a modern automatic transmission system. It should be noted that the system for monitoring environmental safety indicators of vehicle, which is proposed by the authors, also contains in its composition the subsystem of intelligent processing of primary information, which can be used precisely in the role of "intelligent monitoring system". The data obtained and analyzed in the work indicate the need to also improve the efficiency of the neutralization of harmful substances in the engine warm-up mode, which can be implemented by reducing the engine warm-up time and more effective control of the injection/ignition process in transient modes, as well as by introducing an improvement algorithm of the control subsystem composition of the mixture precisely with feedback.

The main diagnostic parameters of the vehicle engine during the start-up and warm-up processes, which affect the composition of harmful substances in the exhaust gases, were obtained experimentally. The proposed scheme for monitoring pollution of the roadside environment by traffic flows in the city.

Formation of the conditions for the effective functioning of the transportation system of the road transport enterprise

2024-07-10T09:15:14+03:00

Road transport enterprises must constantly pay attention to increasing the efficiency of the production of quality transport services, in accordance with the requirements and expectations of consumers. During the production and provision of transport services, the flow of production processes in the transport system, problems often arise in the external and internal environment of the enterprise, which require a mandatory solution. The most common problems include the following: non-compliance of technical means with the requirements and expectations of service consumers in terms of the quality of passenger service, ensuring the necessary conditions for cargo transportation; significant negative impact of the transport process on the natural environment; not fully ensuring the safety of passenger transportation and ensuring the safety of traffic on the roads; imperfection of the system, methods, mechanism of planning and monitoring of transportation processes; imperfection of regulatory and legal regulation and control of the technical condition of vehicles in the organization of transportation; the level of driver training is not always sufficient.

When conducting research on the organization of transport processes and ensuring traffic safety on roads, the enterprise must use a methodical approach to evaluate the process of production of transport services, the functioning of the enterprise's production process, which must include three main stages: development of indicators and mechanisms for evaluating the flow of processes; assessment of the efficiency of the transportation process; analysis of assessment results and development of measures to improve service production processes. The main tasks of improving the processes of service production are the formation of the transport system of the enterprise, which includes: transport flows, personnel and technical support of transport, road environment in the transport zone. The transport system and all its constituent parts must be provided with means of monitoring and mechanisms of influence and improvement of the processes of production of transport services.

The process of improving the functioning of the enterprise's transport system should be conducted in three important directions: monitoring the transport process, studying and analysing the service market and taking into account the requirements and expectations of consumers, using calculation methods to determine negative impacts on the process and developing measures and mechanisms to prevent them.

Methodological approach to solving the problem of functional reliability of automobile transport systems

2024-07-10T09:40:27+03:00

An analysis of methods and techniques for solving the problem of increasing and ensuring the appropriate level of reliability of technical systems was carried out, which made it possible, based on the use of analogies, to find out the directions for ensuring the reliability of automobile transport systems.

The essence of the concept of the reliability of the functioning of automobile transport systems for the transportation of goods and passengers from a methodological point of view is clarified. The insufficiency of regulatory and legal documentation for the development of methods and techniques for assessing the reliability of transport systems is substantiated. The synthesis of the concepts of "management" and "reliability" of the functioning of transport systems in comparison with similar concepts of technical systems is considered.

The expert method and methodology of expert assessment of the reasons for failures of the production subsystem of the motor vehicle enterprise and its services are considered. It was found that factor analysis in combination with expert assessment makes it possible to assess the significance of the reasons for failure of transport systems and their frequency. In accordance with the classification of failures of technical systems, an analysis of their belonging to automobile transport systems was carried out.

The classification of failures of technical systems according to different sets of features is analyzed. It was established that the classification of failures of automobile transport systems is based on the use of analogy with the classification of failures of technical systems, as well as on the results of the analysis of the factors of the causes of failures that occur in the production system of the carrier's enterprise. It was revealed that the selection of significant factors affecting the failure of automobile transport systems is based on the method of expert evaluations, their ranking by importance was carried out, and their relative frequencies were calculated. The results of the factor analysis of the reasons for the failure of the production subsystem of the motor vehicle enterprise are given.

It is assumed that by analogy with technical automobile transport systems, they are also subject to decomposition by stages of the life cycle. Therefore, a sudden failure of automobile transport systems is characterized by a sudden change in the values of one or more initial parameters agreed with the customer, and a gradual one occurs as a result of a slow, gradual deterioration of the functioning characteristics of the subsystem or the system as a whole or a participant in the transportation of goods and passengers.

Improving the fuel efficiency of a spark ignition engine under full load conditions by adding nitrogen oxide to the air charge

2024-07-10T10:29:13+03:00

The article presents the results of the oretical studies on the impact of methods for improving the energy characteristics on the fuel economy of a spark ignition engine with feedback and a three-way catalytic converter under full load conditions. Various methods for improving the energy characteristics of spark ignition engines to achieve high energy efficiency are known. The most commonly used method is enriching the fuel-air mixture under full load conditions. However, this method has several drawbacks, including reduced fuel economy and inefficient operation of the catalytic converter. Another known method for improving the energy characteristics of spark ignition engines is by adding oxygen-containing gases, particularly nitrogen oxide, to the air charge, where oxygen by volume constitutes 33%, significantly higher than in air (21%). This method is widely used for boosting the performance of sports car engines. However, there is a lack of research on the impact of this method on fuel economy compared to the enrichment method in the literature. Improving the fuel economy of the engine without deteriorating the energy characteristics is possible by transitioning from operating on enriched fuel-air mixtures to operating on a stoichiometric mixture by adding nitrogen oxide to the engine's air charge. This task was addressed in the article through calculations using experimental data. Fuel economy was evaluated by comparing the specific effective gasoline consumption determined by the engine's work when using an enriched fuel-air mixture and adding nitrogen oxide to the air charge to regulate it to a stoichiometric mixture. It was shown that using nitrogen oxide additives to the engine's air charge can improve fuel economy and increase engine energy characteristics compared to the method of enriching the fuel-air mixture.

Ways of optimizing the quantity of individual transport in the limited possibilities of the street and road network

2024-07-10T10:41:17+03:00

An analysis of scientific research was conducted in the direction of reducing the negative impact of the use of individual vehicles on the street and road network of cities. In order to solve the problem of transport oversaturation of public transportation systems, the foreign experience of limiting the use of individual vehicles on the street and road network of cities was analyzed. The main directions of restrictions on the use of individual vehicles on the street and road network of cities have been established, including restrictions on the operation of individual vehicles depending on the number of passengers in the cabin, the digital configuration of the state license plate, and the presence of vehicle certification. Methods of limiting the operation of individual vehicles in the busy part of the city were also considered. These measures are aimed at reducing the intensity of traffic in cities and increasing the filling factor of the vehicle interior. Considering that a large share of individual vehicles used in Ukraine belongs to Euro-2 and Euro-4 environmental standards, their use significantly worsens the environmental situation in large cities. Approaches aimed at increasing the use of public transport and other alternative modes of transport for transporting passengers in cities are summarized, which reduces the load on the street and road network and improves the environmental situation. To solve the described problems, it is necessary to use a comprehensive approach, in particular, to apply measures of both a regulatory and an informational nature, primarily to popularize the use of public transport. The proposed measures to solve the described transport problems will improve the comfort of transport connections for all road users and the environmental situation, especially in large cities of Ukraine.

Combined method of foundry and thermal processes of manufacturing castings from iron-carbon alloys

2024-07-10T10:55:03+03:00

With the help of innovations at an industrial enterprise, it is possible to increase labor efficiency and reduce the resource intensity of production. The relevance of the development of the technology of metal casting in sand molds, as the most common casting process, is justified by the fact that up to 80 % of the tonnage of castings is produced in such molds, including special types of casting in molds from sand materials. 60-70 % of the equipment capacities, areas, and personnel of foundry shops are attributed to molding processes, including mixing and rod production. Pollution "due to the mold" can reach up to 80%. A significant potential for the development of foundry mold technology is the improvement of the processes of casting metal into molds made of loose sand without a binding component, in particular, according to the Lost Foam Casting Process (LFC). The authors present the concept of improving the processes of casting metal into molds made of loose sand by the method of dual application of molding materials and give examples of such application. The use of loose molding sand for rapid cooling of the casting, including heat treatment, is able to strengthen its metal and reduce the duration of cooling of the casting in the mold, which leads to an increase in the productivity of foundries without increasing the number of furnace equipment and loose mold filler. The applied method of isothermal hardening (austempering) from the hot state of castings from iron-carbon alloys excludes heating with exposure for austenization of castings, which reduces the cost, time and energy consumption of obtaining products with a strengthened bainite structure, which, in fact, corresponds to the concept of realizing internal reserves as a foundry sand mold, and cast metal. Some foundry enterprises of the Vinnytsia region also use LFC or have concluded contracts, planning to reconstruct their shops for this ecological and economically beneficial foundry technology.

Methodological basis of determination and control biofuels expenditure in the vehicle movement process

2024-07-11T09:13:55+03:00

The paper proposes a methodological approach to determine and control fuel consumption (biofuels) of a car that has known design parameters and moves in known conditions at known modes. It is noted that at this stage it is more attractive to use mixed fuels based on gasoline or diesel fuel with the addition of various impurities of biological origin. For gasoline-based fuels, impurities can be methyl or ethyl alcohol, for diesel fuel – vegetable oils, as well as their methyl and ethyl esters of these oils.

A structural and logical scheme has been developed, which explains the main provisions of the proposed determining method and controlling the biofuels consumption. In the structural and logical scheme, the following groups of parameters that take place during the car movement are highlighted: parameters of the conditions, the driving mode design. The mutual influence of parameters among themselves and between groups, the influence of the biological component concentration on its consumption, which must be taken into account to determine and control the consumption of biofuels during the movement of the car, was analyzed. It is shown that when switching to the use of biofuel, there is a change in the indicator coefficient of the internal combustion engine, which also affects the change in consumption.It has been proven that in the process of using biofuel, important factors affecting its consumption are density, lower heat of combustion, and the theoretically required amount of air for kg of biofuel combustion, which depends on the volumetric a specific biological component concentration in it.

It has been proven that in the biofuel use process, important factors affecting its consumption are density, lower heat of combustion and the theoretically necessary amount of air for combustion in 1 kg of biofuel, which depends on the volumetric a specific biological component concentration.

Taking into account the relative indicators of the «main» fuel (lower combustion heat, density and theoretically necessary air amount for the combustion of 1 kg impurities), it was established that the smallest increase in fuel consumption by the car engine during operation occurs when rapeseed oil is added to diesel fuel.

Methods of justification of spare parts stocks in the transport process management system

2024-07-11T09:31:17+03:00

The article formulates directions and analyzes the possibilities of substantiating and choosing the most optimal variant of applying mathematical models for forecasting the number and range of spare parts. The provided recommendations allow to take into account the multi-brand fleets of motor transport enterprises and trends for extrapolation in the short term, identified by the results of observations in real operating conditions.

The main reasons for the occurrence of prolonged vehicle downtime due to technical malfunctions are considered. Traditional methods of planning spare parts inventories based on the use of reliability theory and results of mileage forecasting, standard time to failure; inventory management theory and statistical methods for forecasting random processes; methods of operations research; economic and mathematical methods; stochastic methods of transformation of random variables are analyzed. The article formalizes the grouping of factors that affect the size of stocks and the range of spare parts in the operation of rolling stock of enterprises, depending on the state of the system of organization of work of services for maintenance and repair of vehicles; structure of the fleet and technical characteristics of vehicles; level of development of the production base; availability, interest and qualification of personnel; operating conditions of automotive equipment.

It is proposed to improve the logistics of spare parts inventory management and to formulate measures to improve the performance of carriers based on an assessment of the total costs incurred by the enterprise to maintain the reliability of rolling stock in operation and taking into account the amount of lost profit due to vehicle downtime in the technical service units. At the same time, it is recommended to use the mathematical apparatus of fuzzy set theory for decision-making, which allows formalizing the parameters of vaguely defined expectations of consumers of motor transport services and reducing the subjectivity of decision-making when solving problems of optimizing spare parts stocks in the transport process management system based on the analysis of the structure of consumer properties and service quality indicators.

Study of acceleration modes Skoda Octavia on a roller stand

2024-07-11T10:13:35+03:00

As you know, the main characteristics that determine the state of the power unit are the power level and torque. These parameters affect the dynamic qualities of the car and can also play a role in fuel consumption and emission levels.

To check these characteristics, traction roller stands of the inertial type are used. These stands allow you to simulate real traffic conditions and loads. Usually, on such stands, the traction force on the driving wheels is measured, which makes it easy to calculate the power in certain driving modes.

However, creating a full-fledged load on the driving wheels of the car being diagnosed requires the use of powerful loading and driving devices. This significantly increases the cost of the stand and its metal content.

An alternative to this method is the compressed acceleration method. In this method, the load is created by a relatively small inertial mass together with a loading and driving device of moderate power. The diagnostic parameter in this method can be traction force on the wheels, acceleration, time or path of acceleration of the wheels in the selected speed range. For measurement accuracy, it is better to use acceleration time. However, all the advantages of the method can be manifested only with the correct choice of test modes. During testing, results depend on the accuracy and stability of maintaining the test mode. Acceleration time will be measured more accurately, the slower the wheels and rollers of the stand accelerate. During the tests, it is necessary to choose the high-speed measurement mode to ensure a sufficiently stable torque value.

The article analyzes the acceleration modes of a car on a roller stand and their influence on the accuracy of diagnostics. The smallest error is achieved when measuring acceleration time from 50 to 70 km/h in IV gear with additional load or in V gear without load.

The newest technologies in environmentally safe polymeric coatings: research, technologies, prospects

2024-07-09T10:33:51+03:00

The scientific work is aimed at the study of environmentally friendly polymer coatings in the automotive industry, which constantly attracts the attention of scientists and practitioners. The article analyzes the current state of technology in this area, reviews the latest research and technological developments, and discusses their prospects for implementation in production. Starting with a review of the latest research on paints and coatings, the paper goes on to discuss self-healing materials and microcapsules that have the potential to create resistant and durable coatings.
The paper also discusses anti-corrosion coatings, which are an important part of protecting automotive structures from the effects of negative environmental factors. Particular attention is paid to the development of environmentally friendly polymer coatings that meet the requirements of sustainable development and reduce the environmental impact of the industry on the environment.
In addition, the latest trends in the industry are analyzed, which allows us to predict further directions of technology development and implementation of innovative solutions. The work has important practical application in the automotive industry, contributing to improving the quality of automotive coatings protection against corrosion and extending their service life in various operating conditions. The work is aimed at highlighting relevant aspects of research in the field of environmentally friendly polymer coatings and provides a valuable contribution to the development of this important industry. The results will improve the quality and duration of corrosion protection of paintwork, metal structures and other products.
The use of the latest materials and technologies in the manufacture of coatings is driven by the need for their environmental friendliness, efficiency and durability. However, the introduction of some new technologies faces limitations, in particular, related to their economic feasibility and scalability. In this regard, further research is needed to optimize technologies and materials to achieve greater efficiency in road transport.

Application of the CAD/CAE system Solidworks in the tasks of analysis of strength of parts of the clamping fixtures

2024-07-09T11:29:34+03:00

The strength of parts is a critically important characteristic of the design of Clamping Fixtures. Calculating the strength of parts of Clamping Fixtures is necessary both when designing new structures and when checking existing ones. Traditional calculation methods, such as nominal stress calculation, although easy to use, have low accuracy. This creates a need for more accurate and efficient strength analysis methods. Modern CAD/CAE systems, in particular SolidWorks with the Simulation application, provide powerful tools for engineering calculations and finite element modeling.

The algorithm of static calculation presented in the article on the example of the "Grip" part demonstrates the sequence of actions during strength analysis in the SolidWorks environment. This algorithm includes creation of a 3D model, generation of a finite-element mesh, material selection, determination of anchoring and loading conditions, calculation and analysis of results. An important stage of the analysis is the choice of the material of the part. At the same time, it should be taken into account that the databases of foreign CAD/CAE systems may not contain some domestic materials, which requires the selection of analogues with similar characteristics. The system allows you to visualize the results of calculations in the form of colored diagrams of stress and strain distribution. This greatly facilitates the analysis and interpretation of the results, allowing the critical areas of the structure to be quickly identified. The use of CAD/CAE systems for strength analysis of machine tool parts has a number of advantages compared to traditional methods. It increases the accuracy of calculations, reduces the time for their implementation, allows you to easily make changes to the design and instantly assess their impact on the strength of the part. The proposed method allows you to carry out both design and verification calculations of details of Clamping Fixtures. This makes it a versatile tool for structural engineers. The implementation of such strength analysis methods is particularly relevant both for the educational process and for real production. In terms of training, it allows students to gain practical skills in working with modern engineering systems. In production, it helps to improve the quality of design, reduce the number of errors and optimize structures.

Installing two internal combustion engines in series on a vehicle as a method of reducing torque unevenness

2024-07-09T19:15:14+03:00

An analysis of studies on the possibility of reducing fuel consumption of cars by replacing their power plants with two internal combustion engines installed in series is carried out. It has been determined that it is possible to reduce fuel consumption by reducing the unevenness of torque at the transmission input shaft, which in turn depends on the relative angular orientation of the crankshafts of the installed internal combustion engines. The study has determined that when installing two consecutive internal combustion engines, each of which generates an indicator torque that obeys the harmonic law, it makes it possible to shift the curves of the indicator torque and the crankshaft angle so that both engines operate in opposite phases. It is proposed to use a method of increasing the energy efficiency of cars by using two consecutive internal combustion engines, the crankshafts of which are installed relative to their initial angular position with the difference in the angular coordinates (angles of rotation) of the crankshafts of both engines relative to the initial position, which allows to reduce unproductive energy losses. Approximating the actual curves of change of the indicator torque by the harmonic law, taking into account the angle of rotation of the crankshaft, graphs of dependence of the indicator torque on the angle of rotation of the crankshaft of four-stroke internal combustion engines with different numbers of cylinders are constructed. It has been determined that with an increase in the number of cylinders of an internal combustion engine and the coefficient of the share of torque on the drive wheels, there is a decrease in the coefficient of unproductive energy consumption, which takes into account the influence of the unevenness of the indicator torque. The problem of ensuring the operation of the second engine in the counterphase of the first engine is solved, which should be fulfilled by the ratio of the angles of rotation of the crankshafts of the first and second engines relative to the initial (zero) position with the difference in the angular coordinates (angles of rotation) of the crankshafts of both engines relative to the initial position. The results of calculating the angle of the crankshafts' relative position when two internal combustion engines are installed sequentially in the opposite phase indicate a decrease in this angle with an increase in the number of cylinders.

The influence of towing links on the handling of tractor self-propelled chassis

2024-07-09T19:48:05+03:00

An analysis of methods for calculating the distribution of normal reactions of the road between the axles of the tractor unit was carried out. It is shown that they are based on the misconception that traction forces and rolling resistance forces are applied in the spots of contact of the wheels with the road. The research shows that installing a towing link on a tractor self-propelled chassis through the rear suspension system at a level below the axis of the rear wheels (the diameter of which is larger in relation to the diameter of the front wheels) allows reducing the additional unloading of the front wheels. A more correct scheme of the tractor unit with the application of the traction force and the rolling resistance force on the wheel axles is calculated, which determines the increase in the total normal reaction on the front wheels of the tractor self-propelled chassis when working with the towing link. It is shown that an increase in the difference in the dynamic radii of the front and rear wheels, a decrease in the vertical coordinate of the center of mass of the tractor unit leads to an increase in the normal reaction of the road on the front wheels. Since the controllability of wheeled machines increases with the growth of the normal reaction on the front wheels, the presence of towing links with the attachment point located below the axis of the rear driving wheel increases the controllability of the tractor unit based on the self-propelled chassis. The problem of determining the total normal reaction of the road on the front wheels of a tractor self-propelled chassis with a trailing link in the case of application of the traction force and the force of movement resistance on the wheel axles has been solved. To increase the accuracy of finding the total normal reaction of the road on the front wheels of the tractor self-propelled chassis, which will allow to clarify the assessment of the controllability of the latter when moving with a towed link. Increasing the difference in the dynamic radii of the wheels and reducing the base of the tractor self-propelled chassis allows you to increase the value of the total normal reaction of the road on the wheels in relation to the horizontal reaction in the hinge of the axle of the trailer link. It was determined that the operation of the tractor self-propelled chassis with trailing links is characterized by a higher efficiency factor of its chassis compared to a universal tractor of class 0.6 and higher efforts under the condition that its front platform is loaded.

Justification for choosing the type of belt conveyor drive

2024-07-09T20:05:16+03:00

The designs and dynamic properties of electromechanical and hydraulic drives for a belt conveyor have been analyzed to justify their selection. The main advantages and disadvantages of their operation have been formulated. It has been established that the hydraulic drive has advantages compared to the electromechanical one for installation in a built-in drive for a belt conveyor.

The design features and principles of operation of these drives have been described. Calculation schemes have been developed for the electromechanical and hydraulic drives of the belt conveyor. A mathematical model of the electromechanical drive has been constructed, taking into account the Voigt viscoelastic model for the conveyor belt, Hooke's laws for the deformation of stretching elements, equations of motion of the mechanical system, and electromagnetic phenomena in the asynchronous motor. Additionally, a mathematical model for the hydraulic drive of the belt conveyor has been constructed, which, besides the equations of motion of the mechanical system and the Voigt viscoelastic model for the conveyor belt, also includes the continuity equations of the working fluid flows in the hydraulic drive.

The parameters of the belt conveyor for studying the dynamic properties of the electromechanical and hydraulic drives, which are considered in the mathematical models, have been described. The mathematical models for the electromechanical and hydraulic drives have been solved using the Mathcad software package. Theoretical curves for cases of transient processes in the mechanical system of the belt conveyor without load and with load have been constructed. Transient processes of acting torques and angular velocities have been compared by the dynamic coefficient, and it has been established that the hydraulic drive has a better indicator by 1.78 times. It has also been established that the duration of the transient process in the drive with the electric motor exceeds this parameter in the drive with the hydraulic motor by 3.5 times.

It is recommended to use the built-in hydraulic drive for belt conveyors of mobile working machines because it has more advantages over the electromechanical one, and the dynamic indicators of the hydraulic drive provide better performance during operation.

Increasing the efficiency of ensuring the performance of vehicles

2024-07-09T20:37:57+03:00

Accidental failures, leading to unplanned repairs, significantly increase the cost of their elimination compared to planned measures. A significant part of such failures are not sudden in nature. Gradual failure is preceded by a gradual change in some parameters. The impact of gradual failures on the efficient operation of road freight transport is increasing. Despite the fact that the failure of the engine, clutch or automatic transmission is not dangerous to the life and health of people, their impact on the economic condition of the enterprise is significant. There is a trend of decreasing the size of the rolling stock fleet for most of the country's motor transport enterprises. Therefore, the importance of keeping each car in working condition increases. To increase the accuracy of the prevention of gradual and sudden-gradual failures, a forecasting method based on the diagnosis of trucks with a specialized diagnostic car scanner TEXA Navigator MULTIHUB is proposed. The selection of diagnostic parameters was carried out in accordance with the requirements for compliance with the accuracy, efficiency, and informativeness of the diagnostic parameters. The research was carried out on MAN TG-X, MAN TGA, VOLVO FH 12, DAF 105 XF, and DAF 106 cars. A sequential cylinder shutdown test was conducted to determine the compression and efficiency of all cylinders. A gradual change in the operating parameter is determined based on the obtained decrease in revolutions. In the next test, the correction of the injectors for the amount of fuel injected into the cylinders is checked. The reference value is taken as 0. The correction tolerance for increasing or decreasing the fuel supply time should be within +1 or –1. Based on the received data, the nozzle is determined, in the correction gradually increases, which signals a problem with the nozzle's operation. For the clutch, a test of the position of the start of switching on and off was carried out. By reducing the percentage of idling, you can determine the gradual engagement of the clutch. All the conducted tests make it possible to graphically display a change in a parameter or property and, using extrapolation, to predict the moment of failure. All cars carry out freight transportation in international traffic. Control parameters and data extrapolation made it possible to predict engine, clutch, and automatic transmission failures. Selected diagnostic parameters can be used to predict and prevent failures.

Study of the influence of external factors on the operational properties of an electric vehicle

2024-07-09T20:57:31+03:00

Many factors affect the range of an electric vehicle: speed, driving style and ambient temperature can reduce the range of a full charge. Cold weather poses two main problems for electric vehicles: cold air limits battery performance, and the robo-heater significantly drains the battery. Studies have shown that 21.5 degrees is the optimal temperature for the operation of an electric car battery. Because an average of 21.5 degrees Celsius is the most optimal temperature when it comes to the range of an electric car. This actually prolongs its operation. At 21.5 degrees, the electric car's temperature system does not work, so energy is used for its movement. At -20°C, an electric car loses an average of 50% of its battery charge range. At -10 – 40%, at 0 – 20%. When the temperature is +10o C, the real driving distance of the electric car corresponds to 100% charging of the battery. At +21 o C, the real distance can be increased to 15%. When it is +40oC, the performance of the battery drops significantly to 80%, and the rate of charge rapidly decreases as the temperature increases. The energy consumption of electric vehicles is largely influenced by weather factors. Studies have shown the influence of ambient temperature and wind speed on energy consumption. The results show that at low speeds (30 km/h) the relative influence of ambient temperature is extremely high. The lowest energy consumption is achieved at a temperature of 20° C. At higher speeds (130 km/h), the relative influence of the temperature of the external environment is much lower. It has been proven that 21.5 degrees is the optimal ambient temperature for the operation of an electric car battery during operation, a decrease or increase in temperature leads to a decrease in the efficiency of electric car operation.

Mathematical modeling of the movement of an armored vehicle with a 4×4 wheel formula with change of pressure in the wheel tires using the example of through KrAZ-Spartan

2024-07-10T09:01:20+03:00

The authors proposed a study of the passability of trucks and armored vehicles of the National Guard of Ukraine with a 4x4 wheel formula. The movement of armored vehicles (AMT) of the National Guard of Ukraine involves movement both on public roads and off-road. The possibility of increasing cross-country ability by ensuring optimal pressure distribution in the tires of the wheels is being considered. The increase in bearing capacity in difficult operating conditions can be estimated with the help of modern mathematical tools. This allows the vehicle equipment of the National Guard of Ukraine to study the cross-country ability and select optimal parameters when performing service and combat tasks with a certain ratio of technical characteristics in different operating conditions.

As a result of the full-scale war of the Russian Federation against Ukraine, more serious technical requirements are imposed on the vehicles of the Armed Forces of Ukraine (AFU) and the National Guard of Ukraine (NGU) than in peacetime.

Among these requirements, maneuverability is in the first place - controllability is ensured by the ability to move at high speed over rough terrain.

The patency of the AMT of the National Guard of Ukraine depends on many factors, the main ones of which are: the type and quality of the surface on which movement takes place, the pressure in the tires of the wheels, the weight of the vehicle, the order of passing the route of the convoy, etc.

The central air pressure control system in wheel tires (SRPRS) is widely used in various variants of automotive equipment with high traffic intensity, but the main disadvantage of such systems is the need to minimize tire pressure to improve cross-country ability on load-bearing surfaces with low load-bearing capacity. This tolerance can cause the tire to slip off the rim, overheat or burst. This is due to the fact that the maximum speed is limited due to the risk of system failure.

It is recommended to determine the influence of various factors in order to ensure the required level of support patency and analyze it using the example of the KrAZ-SPARTAN armored car with a 4×4 wheel formula.

Analysis of the influence of construction factors on the passability of armored tank vehicles and the method of its increase at the account of automatic regulation of air pressure in wheel tires

2024-07-10T09:34:44+03:00

The purpose of the study is to analyze and determine the influence of various factors on the patency of armored vehicles (AMT) operated by the National Guard of Ukraine. Determination of the change in patency during the movement of AMT in different road and climatic conditions. Analysis of static and dynamic loads, which are characteristic of AMT movement over rough terrain, and their impact on the efficiency of the vehicle. The theoretical component of the study was carried out using mathematical modeling of the work process of regulating the air pressure in tires of AMT wheels, using the example of changes in the characteristics of adhesion coefficients with the supporting surface and rolling resistance depending on the change in pressure and load on the tires of the wheels when the AMT is moving off-road. As a result of mathematical modeling, the dependences of air pressure in tires of AMT wheels were obtained, depending on the coefficient of rolling resistance and the load on each of the wheels. Which, in turn, makes it possible to move to a sufficiently complete mathematical modeling of the movement of AMT on off-road, taking into account the reference cross-country ability.

In the process of theoretical research, the structural parameters of the impact on the patency of AMT were analyzed quite completely, and a generalized comparative indicator of the patency parameters of vehicles was proposed. When analyzing it, it was found that the AMT tire and, specifically, the change in air pressure in it, have a significant impact on the bearing capacity.

The authors propose to use the following evaluation criteria as criteria for assessing the efficiency of the passability when driving on deformable surfaces: a generalized comparative indicator of the parameters of the passability of vehicles. As a result of consideration of which, a significant influence on the patency parameters of the tires and directly the air pressure in them was established. Regulation and change of the air pressure in the tires of the wheels depending on the change in the coefficient of rolling resistance as well as the change in the load on each wheel, which are the ratio of the work that is spent on the traction force when overcoming different degrees of heaviness of the resistance of the supporting surfaces with the effect of deformation. And the load that falls on each of the AMT wheels allowed us to draw conclusions about the improvement of the regular tire pressure regulation system (RPRS) of the wheels.

Study of the process passenger transportation with modeling of public transport stops

2024-07-10T09:52:03+03:00

Public transport is characterized by its accessibility and sharing and is intended for a wide range of people, regardless of social status or income. The main function is to provide the ability to move people from one place to another within the city.

Bus stops are a strategic place to ensure territorial accessibility from central to peripheral neighborhoods. They maintain order and organization in the operation of public transport.

It is the study of the network of public transport routes and stops that is crucial for improving the quality of service, increasing the efficiency of transport systems and ensuring convenience for users. However, in each case, it is necessary to use an individual approach to organizational and planning decisions.

The article describes the peculiarities of the functioning of public transport in the city of Dubno, Rivne region, in the context of research on infrastructure, route network, passenger flow, location and modeling of stops, taking into account the future development of new neighborhoods.

It was found that the route network in Dubno includes 22 public transport routes with 64 stops. On average, 19544 passengers use public transport and get off at bus stops every day - 54% of all city residents. The rapid development of the city requires the arrangement of new public transport stops with changing routes, the operation of which in the overall transportation system was investigated by simulation modeling.

The results obtained will make it possible to develop schedules and routes for public transport and to perform technical and economic calculations for the modern arrangement of stops.

The research reported in this article was conducted at the National University of Water and Environmental Engineering with the support of the Department of Economics and Property of the Dubno City Council.

Operation modes of the manipulator of the repair and evacuation machine

2024-07-10T10:06:41+03:00

With modern methods of conducting military operations, the system of technical support of the troops is of great importance. One of the ways to increase the effectiveness of the system of technical support of troops is the use of armored repair and evacuation vehicles.

It is possible to increase the technical capabilities of armored repair and evacuation vehicles by modernizing existing models, or creating qualitatively new vehicles that take into account the specifics of use and characteristic combat damage of modern weapons and military equipment, the type of engine of the military vehicle, its weight and dimensions and other characteristics.

Improvement and modernization of armored repair and evacuation vehicles allows to ensure their effectiveness. Armored repair and evacuation vehicles demonstrate high efficiency when carrying out operations to extract or lift damaged or stuck, blocked, bogged down, sunken military equipment. In these cases, the traction force of the armored recovery vehicle's own engine is used or its own specialized means of evacuation: crane winches, polyspatch systems, crane booms together with power hydraulic cylinders of their drive, levers, other evacuation equipment.

Features of the lifting and loading equipment include such modes of operation as lifting loads from a solid surface, detaching the load from a viscous surface, dragging at different angles to the support surface, and getting stuck.

The most difficult in terms of dynamic overloads of all elements of the hydraulic manipulator is the mode of partial immersion and dense sticking of the load in clay soil, when after separation from it, the load under the action of the forces of elastic deformations of the suspension flies up to the height of a significant relaxation of the suspension and reaching the upper point, where its speed is zero, falls down on an elastic suspension. At the same time, a three-fold overload of the manipulator links is observed.