Nº 6 (168) (2025)
Technological support of operational properties of machine parts and their connections
SCIENCE BEHIND OF HIGH-TECH TRIBOTECHNOLOGIES DEVELOPMENT
Resumo
High-tech tribotechnologies concept is outlined. Specific examples of the creation of various tribotechnologies are given. The technologies of final treatment of friction surfaces operating under low loads are described. They replace the process of running-in of these friction surfaces, and, consequently, increase the durability of their operation. Technological methods of cylinder liners plateau honing and flat-topped final polishing of bearing journals of sliding bearing shafts are given as an illustration.To increase the durability of bearing rollers, the tech has been developed for their final polishing with closed loop belts. Their width and tension force make it possible to ensure the barrel shape of such rollers, which guarantees an even distribution of pressure along the entire length of the roller. This prevents the possibility of their destruction at the edges unlike in cylindrical shapes.For voyage repair of railway tracks working surfaces a flow process has been developed that ensures the preservation of the rail transverse profile formed during the running-in process in various sections: rectilinear and curved. This tribotechnological process makes it possible to increase the productivity of railway track repairs and their service life greatly. Curved friction surfaces during operation, resulted from different speeds and pressures at different sites when running-in, have different rate of wear, i.e. their optimal crossing profile changes. The above is also true of railroad wheels. Therefore, to increase the durability of the rolling surface of railway wheels, tribotechnology of electromechanical pulse processing has been developed, which ensures uniform wear throughout the profile due to a regular change in the degree of hardening of the wheel profile surface layer.
Science intensive technologies in mechanical engineering. 2025;(6 (168)):2-10
2-10
Technologies of electromachining and combined processing
QUALITY ASSURANCE OF AEROSPACE ENGINEERING PRODUCTS AT THE STAGES OF PRODUCTS PERFORMANCE DEVELOPMENT TEST
Resumo
The paper presents the development of ways to achieve the required quality of promising products in relation to specific products of the aerospace engineering industry. A new selection mechanism for techniques agreed upon in the process of testing the performance for the stable production of high-tech objects of the required quality through the development of a combined controlled technological effect on parts, taking into account their in-service environment. The utility principle has been adopted as the main criterion for a methodology aimed at reasonable selection of technological modes when creating promising handling technique with a combination of various routes of exposure, which allows for a discrete assessment of industrial performance level. It is shown that the value of scientifically justified labor and financial costs of the considered method is used as a boundary condition in modeling processing operations to ensure the performance of high-tech products being created and upgraded at the stages of mechanical engineering mass production, the parameters of which are agreed with the customer and justified by the product developer at the stages of products performance development test. New technological methods and devices are proposed that ensure high efficiency in creating new-generation products using examples of aerospace technology with the required performance. New technological methods and devices at the stage of invention are proposed. They ensure high efficiency in creating new-generation products using examples of aerospace technology with the required performance. An evidence base has been created for the technological services of machine-building enterprises, ensuring that the achieved performance indicators of products are consistent with customer requirements and are confirmed in the process of products performance development test at the stages of their creation, improvement during debugging, mass production and operation.
Science intensive technologies in mechanical engineering. 2025;(6 (168)):11-18
11-18
IMPROVING THE MANUFACTURING EFFICIENCY OF NON-RIGID PARTS BY INTRODUCING THE ENERGY OF MODULATED ULTRASONIC VIBRATIONS INTO THE SHAPING ZONE
Resumo
The use of ultrasonic dimensional technologies to reduce technological residual stresses occuring under machining of non-rigid blanks in parts made of alloys with a low melting point is one of the most effective methods for manufacturing structurally complex parts. The main methods of using modulated ultrasonic vibrations (UsV) and their advantages when introduced into the machining zone during milling operations are viewed. Special attention is paid to the use of various types of UsV modulation to increase the efficiency of reducing technological residual stresses by involving dislocation segments of different lengths in the relaxation process when machining thin-walled non-rigid aluminum alloy blanks. The technological residual stresses were evaluated using the Seton-ARM measuring and computing complex. Phase changes in the surface layer of aluminum parts of the Rikor–7 X-ray measuring complex. The data obtained was processed on a computer using the MD-10 program. The UsV modulation was carried out using an original installation that includes a ultrasonic generator, a PC that generates a modulation signal into two channels: on the first channel, a sinusoidal one, on the second, a sinusoidal, square or triangular one with a phase offset of 0 or 90 degrees. Studies measuring the positions of the treated surfaces of thin-walled parts using the Renishaw OMP40 contact sensor have shown that their twisted effect decreases by 30...40%. There was no significant difference in the results of processing workpieces made of deformable aluminum alloys D16 and AK6.
Science intensive technologies in mechanical engineering. 2025;(6 (168)):19-30
19-30
Technological processes automated control
TECHNOLOGICAL QUALITY ASSURANCE IN ROBOTIC FINISH BASED ON ADAPTATION TOOLS
Resumo
Industrial robots are used for machining in mechanical engineering. This trend is associated with an increase in the geomet-ric complexity of parts and wider kinematic capabilities of industrial robots in comparison with classical CNC machines. The article analyzes the technological capabilities of using industrial robots in finishing machining operations, and pro-vides the reasons for limited robots introduction Schemes of construction of technological operations are given: "part in hand" and "tool in hand". The factors influencing the choice of the preferred machining are studied. The areas of effective application of passive and active adaptation tools are given. The article provides two main reasons for possible vibrations under robotic manipulation: e.g. low rigidity of the industrial robot structure and shape errors effect in the previous opera-tion. The problem of developing a sustainable code conversion for the amount of material removal is discussed. The problem statement is due to the fact that the model of the cutting process varies greatly depending on the cutting conditions. Force control work makes it possible to take into account the rigidity of the robot without sacrificing the running accuracy in six coordinates. The article discusses the use of a neural network and a genetic algorithm in the development of a robotic pol-ishing operation for a flat surface within limited access constraints. The authors of the article have developed a postproces-sor for controlling an industrial robot in case of variable tool overhang and uneven tolerance. Special technological equipment has been designed and manufactured for this purpose. Experiments on testing of the developed algorithmic and software have been conducted in the laboratory "Industrial Robots and Automation Tools"
Science intensive technologies in mechanical engineering. 2025;(6 (168)):31-39
31-39
Technologies of mechanical processing of workpieces
ENGINEERING SUPPORT PROBLEM FOR THE STABILITY ASSUARANCE IN DEEP DRILLING OPERATIONS FOR LARGE-SIZED FORGING AND PRESSING BLANKS WORK ON MULTI-PURPOSE CNC MACHINES
Resumo
the article discusses the problem of technological stability assurance of deep drilling operations performed on automated equipment – multipurpose CNC machines. A group of large-sized forging parts and pressing blanks is viewed. It is shown that using a set of special drills and counterboring tools instead of universal horizontal milling machine makes it possible to avoid making special tools and contributes to the improvement of cutting modes, but the problem of stability assurance re-mains. A study of the hardness of such forgings revealed the unevenness of this characteristic in various parts of the work-piece. Despite the fact that, from the point of view of statistics, the totality of experimental data is homogeneous and the flow process of metallurgical forging production is stable, the revealed hardness variability turns out to be very sensitive for the subsequent stage of machining, namely for its special type like deep drilling. Experimental studies of chip formation in hole-making operations have proved that. It is noted that the task of managing the operability of tools and the quality of the re-sulting surfaces should be solved both at the stage of process design and just within operations. The latter can be solved through adaptive control, which is implemented on modern mass-produced multipurpose CNC machines in terms of the op-erating cutting power, which does not require retrofitting an automated machine-tool fleet for machining sites. The ra-tionale for the selection of factors and their variation levels in the construction of regression models used for design process and adaptive control of deep drilling operations on multipurpose CNC machines is given.
Science intensive technologies in mechanical engineering. 2025;(6 (168)):40-48
40-48