Road-building Machines Research Articles

Methodology for forming a rational structure of technology for the restoration of car, vehicle and road-building machinery parts

The scientific work examines the problem of effective and high-quality restoration of cars, vehicles and road construction machines. The assessment of approaches in determining the method and technology for restoring parts of roadbuilding machines is considered. The decisions at the stage of choosing a method for restoring parts and at the stage of forming the general structure of the technological process are analyzed. The new approach makes it possible to achieve maximum efficiency in structuring the technological process of restoring parts of road-building machines; it is carried out according to a number of well-founded criteria when integrating the zoning method on the principle of observing the ratio of probabilities of possible states of the research environment in solving the problem of dynamic programming. Keywords truck, vehicle, road construction vehicle, part restoration, mathematical model, quality, restoration quality indicators

Features of forming a park of road construction machinery in modern conditions

The purpose of this article is to consider existing methods for forming fleets of road construction equipment, to analyze the advantages and disadvantages. The article discusses the most common methods for creating fleets of road construction equipment. Comments are given regarding their applicability in modern conditions. Keywords road-building machines, methods for forming parks, efficiency, analysis

ИССЛЕДОВАНИЕ ЭФФЕКТИВНОСТИ ТЕПЛООБМЕНА И РАБОТЫ ГИДРОПРИВОДА ЭКСКАВАТОРА ПРИ ИСПОЛЬЗОВАНИИ РЕГЕНЕРИРОВАННОГО МАСЛА

This article discusses the technique of optimizing the desing of the exchanger for cooling the working fluid of the hydraulic drive of road-building machines on the example of excavator. The authors analyzed the effect jf the oil regeneration process on the operation of the excavator’s hydraulic system and the effect of regenerated oil on the operation of the regenerated oil on the operation of the excavator’s hydraulic drive heat exchanger, which serves to cool the excavator’s working fluid. The regeneration of used oils is one of the most promising ways to save lubrications, as well protect the environment from getting into it both directly oils and combustion products during their disposal. Unlike oil liquid fuels, waste oils do not evaporate and are less susceptible to biodegradation. At the present stage of development of the human community, there is still no objective possibility of creating a waste-free system for ensuring its vilal activity. However, the organization of rational use of natural resources is quite possible. One of the ways to solve this problem is to develop new and improve existing technologies for the conversion of raw materials, in particular, the regeneration of used oils. Up to 15 liters of oil circulates in the hydraulic system. The price of oil is quite high. Therefore, it is advisable to use regenerated oil from resources and improving the ecological situation.

Metallographic Appraisal of Alloys for Components of Tractors and Roadbuilding Machines

Metallographic Appraisal of Alloys for Components of Tractors and Roadbuilding Machines

Metallographic examination of alloys of parts of tractors and road-building machines

The sequence of examination of materials for parts of tractors, agricultural and road-building machines is considered. On the example of component parts made of Al, Fe and Cu alloys, the establishment of their grades is shown. Keywords: metallographic and metallurgical examinations, research, agricultural and road-building machines. zhulai@vgasu.vrn.ru, 382652@mail.ru, romansheps@yandex.ru, elena_tarasova@ro.ru

Modern structural and operating materials in development of road-building machines

BACKGROUND: The analysis of modern state of using structural and operating materials in development of road building machines is given in the article. AIMS: To highlight the most important tendencies in obtaining modern structural and operating materials in development of road building machines. METHODS: The study subject is modern structural and operating materials in development of road building machines. The novelty of the study lies in highlighting main modern tendencies of modification and technological features of modern structural and operating materials for road building machines with enhanced mechanical strength characteristics. The materials of the study include main scientific and practical information on ways of using structural and operating materials in development of road building machines. The study methods include classification and integration of the information on the topic of modern structural and operating materials in development of road building machines. RESULTS: It is found that the key difference between steel types for structural and operating materials as a part of development of units, mechanisms and parts of road building machines is parameters of corrosion resistance, which is defined by qualitative and quantitative chemical composition directly. Among the main issues of modern industry development, improvement of cost-performance ratio of road building machines, their mechanisms and engineering parts by means of reducing specific metal content and increasing operational reliability and durability is outlined. CONCLUSIONS: It is shown that, opposed to majority of low-alloyed structural steel types, change of austenite in steel types, micro-alloyed with vanadium and niobium and with strength class in the range from S350 to S490, with constant cooing according to the thermal cycle of welding performs mainly in bainitic range. As a result of structural changes, taking place in steel and influenced by thermal cycles of welding, the static strength indicators of the metal in zones of thermal impact of welding joints increase, whereas the indicators of plastic properties reduce. Sufficient reduce of impact viscosity of the metal in zones of thermal impact of welding joints of micro-alloyed structural steel types is observed at w6/5 5C/s. With increasing of cooling speed, the impact viscosity of the metal in zones of thermal impact rapidly increases and it may achieve the level of the main metal in some steel types.

Определение вязкоупругих характеристик эпоксидно-песчаных композитов, применяемых при ремонте дорожных машин

The composition and features of the manufacture of specimens of epoxy-sand composite used in the field repair of road-building machines are considered. The results of determining the impact strength of epoxy-sand composite specimens are presented. It is shown that the presence of a dispersed filler has a little effect on the values of impact strength. It has been established that specimens with the lowest concentration of the dispersed filler have the best viscoelastic characteristics.

Repair of Parts of Road-Building Machines Operating in a Wet Environment

Repair of Parts of Road-Building Machines Operating in a Wet Environment

Model Optimization of the Road Construction Machinery Active Working Elements, Operating in Permafrost

When designing a railroad track it is necessary to take into account a range of different factors especially if the construction of the track is carried out in areas with adverse climatic conditions, which applies to the conditions of the Far North. During construction of a new roadbed in modern conditions track and road-building machines are widely used which have constantly increasing power and speed, and therefore factors of dynamic influence on active working bodies of machines change. The designs of road-building and track machines take into account various types of loads, including dynamic ones, necessary for modeling working bodies. In this case, the modeling process is considered one of the ways to predict and optimize the mechanical systems of track and construction machines, widely using full-fledged models used to obtain new data on the designed object.

Modeling of quality criteria for the restoration of car parts, vehicles and road construction machines

The quality criteria of car parts, vehicles and road-building machines are analyzed from the point of view of efficiency. The interrelations between the quality criteria and the functionality of the part are established. New parameters are proposed in the form of coefficients describing the roughness, hardness and slant of the part. The purpose of introducing these coefficients is consistent with the model being developed for choosing the optimal technology for restoring parts of cars, vehicles and road construction machines. Keywords: automobile, vehicle, road construction machine, hardness isotropy coefficient, technological roughness isotropy coefficient

Исследование стойкости эпоксидно-песчаных композитов к воздействию агрессивных сред

The composition and production features of specimens of an epoxy-sand composite used for repair of road-building machines have been examined. The results of the effect determination of corrosive environments on the properties and the structure of the epoxy-sand composite are presented. It is shown that the structure and the properties of the material considerably depend on the concentration of disperse particles. It was found out that a decrease in the filler concentration ensured the best resistance of epoxy-sand composites to the effect of corrosive environments.

Modeling of recovery systems for motor vehicles and road construction machines

The application of the typification of technological processes in the restoration of the most wearing parts of cars, vehicles and road-building machines is considered from the point of view of the application of optimization of the choice of the best quality parameters. A mathematical model for the restoration of a part is proposed using the solution of a multicriteria dynamic problem using the zoning method. The goal is to achieve maximum efficiency in structuring the technological process of restoring parts of cars, vehicles and road-building machines according to a number of reasonable criteria. Keywords: car, vehicle, road construction vehicle, restoration parts, mathematical model

Application of traction balance analysis to increase operating efficiency of road-building machines

Operation of road-building machines is attributed to accelerations, especially in case of speeding-up or taking-off. Established accelerations in machine assemblies and interfaces, as well as in their units, cause additional dynamic loads that increase parts wear and decrease their service life. Acceleration is facilitated by vibration that increases deformation of parts and assemblies, which infringes specified settings and disturbs the process flow, making it unstable. Besides, the engine power utilization factor and machine capacity decrease, fuel consumption increases, which eventually affects economic parameters. It has been demonstrated in practice that optimum conditions of road-building equipment operation, in terms of occurring accelerations and vibrations, take place when unit driving force and the sum of motion resistance forces are approximately equal. Analysis of the traction balance curve of a machine under review, as related to adherence parameters, reveals areas that can be used to determine the maximum traction that can be generated by this machine under particular operating conditions. For instance, in case of low adherence values, a machine is unable to take off and the wheels will be slipping, until the balance point is reached. Further, as the balance point is exceeded, the machine can overcome motion resistance, unless it exceeds the difference between the maximum driving force and the sum of resistance forces, i.e. in case of normal operation. In case of operation within the high adhesion area, a machine engine can stall. Traction balance analysis results of a particular machine can be used to anticipate reasonable conditions and efficiency of road-building machines operation.

Development of a method for designing specialized machinery based on a hinge tractor

The method of designing frames of special machines for road construction and public utilities is considered, which allows you to design special machines with a given level of reliability and durability. The technique allows using modern computer modeling systems to carry out constructive refinement of the base tractor frame using experimental and mathematical modeling data. Using the design feature of tractors of the T–150K family, namely the presence of an articulated joint, it is possible, using a modular principle, to quickly design various machines for various industries. However, in order to design reliable machines, one must have a methodology for designing such machines. There is currently no such technique. When designing special machines, designers perform calculations only for working equipment. But as practice shows, the critical elements of the machine in this case, the support of the vertical hinge of the tractor frame during the operation of the pressurized machine (wheeled bulldozer and front loader), experience shock loads that lead to the destruction of the frame of the base tractor. The purpose of the article is to develop a methodology for designing a complex of road–building machines on the basis of mass–produced tractors with an articulated frame produced by public limited company "KhTZ".

Системы автоматического управления и регулирования теплоэнергетических установок

The modern stringent requirements for fuel efficiency, exhaust gases toxicity and dynamic performance can only be met by equipping thermal power plants with modern control and regulation systems. Thermal power plants based on internal combustion engines have found the greatest application. They are used in different fields --- automobile and railway transport, agricultural, road-building and forestry machines, in ship-building, aviation, stationary power plants. The analysis of the main directions for further improvement of thermal power plants with internal combustion engines and their automated control and regulation systems has been carried out. Among these directions are an expansion of functional capabilities in such systems, improvement of control and regulation processes quality and their use at adaptation of thermal power plants to work on alternative fuels. The important aspects for improvement of thermal power plants with internal combustion engines are the necessity of studying the working processes of engines and their systems in order to decrease the exhaust gases toxicity. The relevance of these systems research is shown and the evaluation of the current level in their development is made. A characteristic feature of modern control and regulation systems of thermal power plants is their widespread construction on modern microprocessor element base The paper was based on the materials of the reports of the all-Russian scientific and technical conference n.a. Professor V.I. Krutov (27.01.2021)

Особенности технологий ремонта основных элементов гидравлической системы дорожно-строительных машин с применением полимерных композиционных материалов

Features of the operation and typical damages of standard hydraulic systems’ elements of road-building machines have been analyzed. The occurrence reasons of defects and the elimination ways of them were determined. Methods for eliminating the defects were analyzed, and it is shown that one of the most promising methods for eliminating the defects in liners of hydraulic cylinders and hydraulic lines is the use of polymer composite materials with a fibrous or dispersed filler for the repair.

Prospects of Application of Glue-Riveted Technology in the Creation and Repair of Road-Building Machines under Conditions of Sharp Thermal Fluctuations and Low Temperatures

Prospects of Application of Glue-Riveted Technology in the Creation and Repair of Road-Building Machines under Conditions of Sharp Thermal Fluctuations and Low Temperatures

Determination of factors of operational technical readiness and ageing of roadbuilding machines

The purpose of this article is to show how in practice it is possible to determine the actual rate of operational technical readiness of road construction machines in three different ways. This will allow you to compare them and give them an assessment. It is well known that in practice, with an increase in the life of road construction machines, their production time decreases. This is due to such a phenomenon as the aging of road construction machines. In this article, the actual ageing factor of road construction machines will still be determined. Keywords: road construction machines, technical readiness coefficient, operational technical readiness coefficient, ageing coefficient

Automatic Control System of Asphalt Concrete Milling Process Based on Road Milling Machines

Mechanical impact on the upper layers of the road surface with the removal of damaged sections of asphalt concrete surfaces is carried out by specialized Road-Building Machines (RBM) - (cold planer). The capabilities (technical resources) of such RBM have not been fully used. Under these circumstances, a promising area of scientific research is the development and implementation of automatic cold milling process control systems with further improvement of their main functional units and mechanisms. In the article, for the first time, Road Milling Machines (RMM) are represented by a set of interconnected controlled systems, united by the ultimate goal - the removal of asphalt concrete pavement layers corresponding to the thickness of the damaged areas with the further formation of a new pavement, which made it possible to apply the principles of automatic control to the process of milling asphalt concrete pavement by road milling machines.

Modeling quality criteria for restoring parts of cars, vehicles and road-building machines

The article analyzes the types, methods and techniques of parts processing at restoration and quality criteria of parts of cars, other vehicles and road-building machines in terms of efficiency. Correlations between the quality criteria and the functionality of the part have been established, for which the requirements for machine safety and reliability after the restoration of individual parts have been taken. A mathematical model has been developed in the form of an algorithm for selecting the best variant of the restoration technology for a functionally important part, based on a typical restoration technological process, which consists in the development of a multi-criteria problem, the initial postulates of which are matrices: W “wear resistance → durability”; S “safety → reliability”; F “part fragility → machine safety”. New parameters in the form of coefficients describing roughness, hardness and riveting of a part have been proposed. In particular, the authors define the coefficient of technological isotropy of roughness, which evaluates the roughness parameters in the process of technological changes of a part; the coefficient of isotropy of hardness, which compares the hardness parameters on the surface of the part and in the core of it; the coefficient of intensity of hardness, which is a complex parameter and in which there is a change of hardness by the depth of the part and the value of hardness depth (riveting). The purpose of introducing these coefficients is consistent with the model being developed to select the optimal technology for restoring parts of cars, other vehicles and road-building machines.