No 2-2 (2015)

The article presents a wide range of previously unknown pages of the history of Togliatti State University (TSU) related to the activities of the university leaders in the first two decades of the high school activity. The paper covers the period from its founding in 1951 as a branch of the evening school of the Kuibyshev Industrial Institute of Kuibyshevhydrostroy in Stavropol-on-Volga till 1971, when Togliatti Polytechnic Institute (TPI) had got material and technical resources, scientific and pedagogical staff, and foundations for the development of scientific schools.

For the first time, the article presents in its scientific consideration the relevant biographical information – in its chronological sequence – about all six leaders of the higher school: the heads of the evening department of the Stavropolsky branch of Kuibyshev Industrial Institute of Kuibyshevhydrostroy D.E. Churkin and V.N. Nikolayev, the directors of the Stavropolsky branch of Kuibyshev Industrial Institute V.N. Zubkov, V.L. Bondarev and E.F.Vinokurov, the rector of Togliatti Polytechnic Institute A.N. Reznikov. The author reveals the peculiarities of the interaction of the university leaders, the city administration and construction projects aimed at expanding the scientific, educational and pedagogical tasks and creating a common educational network of the city. Two phases of development of the university are considered in details: first, the initial period of establishment of the evening school of KII of KHS before the city of Stavropol-on-Volga had been transferred, and the early years of the new city under construction. The research reports the effective support provided to the branch by the head of "Kuibyshevhydrostroy" I.V. Komzin, and his teaching activity as a professor.

The second period is when an independent higher school was created in Togliatti – Togliatti Polytechnic Institute (TPI). The creation of the first independent university in Togliatti is connected with the name of Professor A.N. Reznikov, an honorary citizen of the city of Togliatti. The article considers its effective cooperation with the Volga automobile factory and other factories of the country; studies the basic activities of 12-year history of TPI when the higher school was not only expanding, but also became a scientific and educational center of the Volga region.

The article covers the foreign and domestic experience in development of dry processing technologies. The authors give the results of the introduction of dry processing technologies (cutting, turning, milling, drilling) on the manufacturing companies in Germany. The article presents the analysis of lubricoolants consumption carried out at the JSC "AVTOVAZ", and describes the negative impact of lubricoolants on the human organism and the environment. Possible pathways of lubricoolants components to the atmosphere and soil are described.

Lubricoolants, in most cases of technological process engineering, are considered to be the obligatory components. The authors described three basic missions of lubricoolants: cooling, lubrication, and chip clearance that are essential for steady process behaviour.

The article describes the influence of lubricoolants deletion from the treatment process. The authors compared the microrelief with the base and the proposed processing technologies and developed the phenomenological model of wear of tools made of polycrystalline material with a homogeneous structure when processed by surface plastic deformation. To exercise the stochastic nature of impact of tool roughness on its wear process, the algorithm of tool surface microgeometry forming was developed. While solving the problem of automation of determining the area of tool work surface wear the calculation algorithms and IZNOSOMER software were developed. The system has the advanced capabilities to create a user interface, a wide range of functions, methods, and properties necessary for solving applied computational and engineering challenges. The solutions obtained are based on the use of domestic technology and tools only, and allow rejecting the purchase of import equipment at the cost of up to EUR 1 million per unit, by increasing the loading of machine-building enterprises of the Russian Federation. Processing without lubricoolants technology eliminates the fire hazard from oil lubricoolants, environmental pollution and harm to human health.

System approach is widely used in modernization of business-processes, organizational structure, corporate documentation procedure and economical information systems. The application of methods of system analysis when introducing the results of engineering research is not covered sufficiently today, that is why the aspects of work related to the application of IDEFO notation to the description of the system being worked out upon the results of scientific researches in the field of metal cutting is important now.

The work covers the application of methods of system analysis when assimilating the results of researches of assessment of metal cutting tool wear rate using the acoustic emission of cutting process. The authors used the analysis of processes in IDEFO notation to describe the developed information system for material machinability estimation. 

The authors developed the context diagram containing the external interactions of the analyzed system. The internal interactions of the analyzed system at the high decomposition level are displayed on the diagram of decomposition of the first level. The authors carried out the structuring of system functions and necessary for system functioning resources within the frames of input, output, supporting and regulating parameters of the processes. The article offers the methods of assessment of machinability based on the use of visual and numeric representations of the information and the application of modern technologies of semi-structured information processing. 

The results of the research showed that the use of the process analysis according to the IDEFO methodology is the effective tool allowing at the stage of the research results implementation to structure the information interactions within the frames of input, output, supporting and regulating parameters of the processes at different levels of the system detailing. The application of the system analysis methods to the description of the system for machinability assessment using the acoustic emission signal allowed identifying the basic requirements to the information system which specialization is possible within the frames of accepted methodology when moving to the lowest levels of decomposition in the system processes description.

The well-known approach to solving technical problems by resolving conflicts through the use of empirical methods is rather cumbersome, and makes it difficult to study it in the course of educational process. The aim of the paper is to develop such a system of empirical methods that would allow studying it within the educational program of training an engineer without reducing significantly its effectiveness. As a part of this goal, the author analyzes well-known systems of empirical methods of solving technical problems with regard to the field of "Mechanical Engineering", and makes an attempt to reduce the number of techniques without losing their effectiveness due to their specialization, as well as by combining well-known methods. The proposed approach allows mastering the method of empirical techniques within the educational process.

As a result, a list of empirical methods and techniques of solving technical problems in the field of mechanical engineering, including 10 techniques: partitioning – aggregation (partition of the object, task sharing, optimization, nesting), elasticity (elastic element, inflatable element), other way (opposite position, opposite action, prior action, asymmetry), curvilinearity (curvilinear element, rotation, rolling), dynamism (mobility, adaptability, intermittence), analogy (a copy of the object, the technical counterpart, natural analogue), damage to the good (usage, intensification, adding, cheap fragility, waste), state (aggregate state, texture, porosity, heterogeneity), mediator (modified object, the third object), physical fields (the field, a combination of fields, physical effects).

Examples of application of empirical methods and techniques in solving engineering technology are given in the article.

The proposed system of empirical methods allows to study them in classes on technical creativity within the time allotted in the curriculum, and use them both for solving educational problems in discipline "Mechanical Engineering", coursework designing and further engineering practice.

Metal-cutting machines involve complex production systems changing their parameters during the treatment process that results in degradation of processing accuracy. There are many factors influencing the processing accuracy but the main factor is the precision of production equipment. The potentialities of classical approaches to the machines accuracy increase have been practically exhausted and now they make no economic sense. That is why the article covering the study of accuracy of processing on precision production equipment is very important now.    

The article describes the results of the study of accuracy of processing of deep holes using the 2A459AF4 precision horizontal coordinate boring machine.

The goal of the study is to prove the influence of elastic power deformations of the frame construction (bending and torsion) of precision horizontal coordinate boring machine on the processing accuracy. 

The measurements of deviation from circular form of a hole were carried out on the base of a special unit under the conditions most closely resembling the real factory world. Basing on the results of the holes selection, the authors plotted the dot diagrams visually indicating the character of deviation of the processed hole axis during its processing. The authors determined that the value of the hole axis deviation in two perpendicular planes is an unstable quantity and depends on the position of moving elements of the machine processing system during the process of treatment. When the holes are located closer to the table reflector, the value of axis deviation reduces. The presence of elastic power deformations of the frame construction causes the blank part displacement and, subsequently, the processed hole axis deviation about the tool axis.

The study was carried out according to the own methods based on the following application software package: Kompas 3D V12, ANSYS Workbanch, MathCAD. 

The article covers the issues of ensuring quality of hard-alloy tools and parts when producing them by means of rational use of ultrasonic fluctuations energy. It is well-known that one of the key indicators of quality of the surface layer of parts or tools is the lack of stretching residual stresses. It is especially important for the tools used for high-speed processing of aluminum alloys blank parts which are not exposed to the drawing of wear resistant coatings, and also for the crown bits and various hard-alloy parts which are widely used in modern machines and mechanisms. As a rule, the blank parts to be produced are processed by grinding at final stages of technological process, after which the stretching residual stresses are inevitable. For their relaxation, thermal treatment or natural aging is used in the production that increases the production cycle and the cost of production. For this purpose, the authors offered to use the ultrasonic field energy; in this connection, special installations were developed and the researches were conducted. During the research, the regression dependences of residual stresses on the parameters of thermal power intensity (the components of cutting forces and the contact temperature in the zone of flat diamond grinding of samples made of ultra finely-divided hard alloy) and the elements of processing mode (the longitudinal conveying speed and the cutting depth) were received. The residual stresses were controlled by means of domestic “Rikor-4” refractometer.. During processing, the authors carried out the assessment and the structural phase changes in the surface (using the x-ray measuring “Rikor-7” complex). The results of researches allowed to determine the velocity of ultrasonic relaxation and the elements of its mode.

The article covers the issues of provision of accuracy of location of automatically changeable units when repackaging the work station of repackaged production systems. The study showed the influence of basing holes relative position on the accuracy of location of automatically changeable units during multisided treatment of parts. To resolve the issues of multisided treatment of parts, the author suggested the model of automatically changeable unit – part carrier for simulation of issues of assurance of accuracy of location on the work station of repackaged production system. The author offers the carrier design in the form of a prism where the basing holes are located on the side edges, and the tool set and the parts are installed in the plane of each edge. In this case, the parts position dimensioned repetitiveness against the work station production units and the equal structural stiffness of carrier body in the directions of parts treatment. The article considers the model of system of equally spaced basing holes for simulation of the carrier accuracy of location. The parameters characterizing the accuracy of processing of each basing hole are defined on the basis of dimensional analysis. The study showed the influence of relative position of each basing hole of the carrier on the accuracy of the part processing. To specify the conditions of treatment of basing holes using the automated equipment, the author determined the parameters of treatment which should be ensured to resolve the issues of accuracy of location of the carrier on the work station. The requirements for technology process of production of basing holes were determined on the basis of simulation of dimensional conjunctions. The study showed the necessity of taking into account the decrease of accuracy of their relative position in the result of processing.

According to the simulation results, the ensuring of required relative position of basing holes during their processing will allow to meet the requirements for relative position of the carriers of the repackaged production systems.

The performance characteristics of the products are determined considerably by the technology process of their production. Modern machine industry sets the requirements to the parts surfaces operating in the friction conditions and the availability of regular microrelief. This work offers the technology and the mathematical model for calculation of the microrelief of processed surface of shaft journal for the cup-type seal. While studying the cup-type seal – shaft friction couple, the main cauces for its wear were determined.

The authors considered the schemes of applying of regular microrelief using diamond burnishing and the schemes and profilograms of surfaces with obtained grooves systems. The authors classified the microreliefs obtained in the result of vibro-burnishing and determined the dependence of microrelief nature on the processing parameters.

According to the mechanical engineering development trend, the authors proposed the change from one parameter describing requirements to the part’s surface microgeometry to the requirement in the form of regular microrelief availability.

The article shows the results of the mathematical model calculation of the diamond burnishing processing which allows to simulate the relief of processed surface depending on the parameters and processing conditions.

The authors obtained the results of simulation of processed part during diamond burnishing with mode superposition. Comparing the simulation results with the theoretical results, it is possible to estimate the adequacy of mathematical model calculations.

The authors made the conclusions on the possibility of using a mathematical model to estimate the obtained microrelief on the part surface after the burnishing with the mode superposition. The results of theoretical research which are used as the base for mathematical model of the burnishing process with the mode superposition correlate with those obtained in reality.

The article considers issues of increasing efficiency in multiproduct machining manufacturing systems by complex automation of production preparation stage. After analysis of modern software possibilities for design automation their shortcomings come to light and the principles are formulated for creation of integrated design and process planning system that ensures effective interaction at various design stages. As a basis for making rational decisions, the automated design system for production operation takes the central place in the integrated technological process planning system. In the course of development of the automated design system for production operations the approaches are found to formalization of design procedures by means of mathematical modeling. An important feature of the proposed models and techniques is the accounting of all planned nomenclature of the processed components as well as orientation to the current state of a production system. For the procedure of equipment generation the model is described with application of Petri nets that allows creating a set of feasible options of cutting and auxiliary tools for all planned nomenclature of the processed components. Elimination of irrational options can be carried out by using criterion of uniformity which ensures invariance of operation structures. For modeling the procedure of generating possible process steps sequences, the graph theory is used. Modeling of procedures for selection of rational equipment sets and operation structures is carried out simultaneously. To do this, the authors suggest using dynamic programming, therefore the system is optimized in general and there is no need for examining of all possible options. Criteria of optimization are the total processing time of all planned components and number of tool changes. In the conclusion of the article the ways of further development and application of the developed system are defined.

The article considers the issue of wear resistance improvement of working surfaces of the parts of machines, equipment and metal cutting tools. One of the most prospective directions in this field is the thermal treatment of wearing surfaces by means of the action of focused heat flows created by laser light. Modern fiber optic lasers are the most advanced from technology viewpoint. The research and estimation of the structure of the overlap areas during multi-pass laser operation are the key elements of preparing of technology process and influences directly the selection of treatment modes. The author gives the results of experimental research of the influence of fiber optic laser treatment parameters on the state of surface layer of the overlap areas during the multi-pass heat treatment of steels and irons. LKD4-015.150 fiber optic laser was used for experimental research. The treatment was performed in the continuous mode with the partial fusion of processed surface. The process mode was selected according to the data of the work “Modification of steel and iron surfaces using the fiber optic laser”. X12MF steel and SCh21 iron plates 15х15х3 mm in size were used as the samples. After treatment, end surface of each sample was burnished at minimal modes in order to eliminate the additional thermal influence on the structure; after that, microslices were produced on the surface. 4-% alcohol solution of hydrogen nitrate (HNO₃) was used as an etchant. The hardness was measured using the Shimadzu HMV-2 microhardness tester. The samples’ structure was studied using the Zeiss AXIO Observer.D1m microscope and the Zeiss LEO1455VP electron scanning microscope.

During this research, the author carried out the analysis of the overlap areas structure and measured their microhardness. The article displays the computational scheme and calculation formula of engagement factor during the multi-pass processing.

Object of research is the protective limiter used in the raising pulse converter of constant voltage (PCCT). The purpose of work consists in justification of a choice of the limiters necessary for restriction of switching revoltage in power transistors at the safe level, at the set parameters of work of the scheme. In article relevance of application of pulse power supply circuits in modern technologies at various types of loading is considered. On the example of the pulse converter of constant voltage the equivalent circuit showing is shown that switching off of the transistor is followed by an overstrain. For restriction of an overstrain it is offered to use voltage limiter. For the purpose of a rational choice of the limiter it is offered to consider switching processes at switching off of the transistor. The analysis of processes of switching is carried out on the basis of the assumptions which are often used in the analysis of pulse processes of pulse converters of voltage. The temporary chart explaining work of the scheme is provided. The analysis of processes of switching is followed by a conclusion of the analytical ratios reflecting key parameters of switching: level of revoltage, switching time, the energy emitted in the limiter for one period and average power of losses in the limiter. The concept of a relative overstrain which is used for a choice of the limiter and the power transistor is entered. Examples of the elements released by the industry which can carry out functions of limiters are reviewed. The analysis of parameters of the limiters released by various producers is carried out. On the removed analytical ratios and proceeding from the analysis of the parameters provided by producers of limiters recommendations and an estimated technique at the choice of limiters for power supply circuits are provided. A scope of this work are schemes with the transistors working in the key modes, such as schemes IPPN.

In the area of automation of process design and stamping objects there are a great number of commercial software products. Each of them has the tools and features aimed at reducing the complexity and accelerating the design time. The article presents classification of the set of domestic and foreign computer-aided design facilities for multiposition stamping objects and processes (CAD MS). The analyzed CAD systems are described by a number of functional features. Using the method of principal components of factor analysis the authors conduct the search of correlations between the features to reduce their numbers. There are five factors (groups of characteristics of CAD MS). The selected factors are given specific names according to the description of their constituent features. The article describes a structural and logical CAD MS framework for the obtained factors. The percentage of computer-aided systems in each factor is presented. For the construction and classification of certain types of CAD MS the authors use k-medium method of cluster analysis. The number of clusters (CAD model) and their volume is defined. These clusters are the best description of a typical CAD MS. The clusters are given the names, and their functionality is described. The defined clusters and their descriptions are coordinated with heuristic division of CAD according to technological and design features. The largest number of CAD MS from the submitted sample refers to technological clusters. Cluster analysis of the large number of CAD shows that the development of design automation of stamping objects and processes is connected with optimization of the sheet stamping technological process and the use of tools and modules of CAE, as well as the development of libraries of standard parts and assemblies subject to knowledge bases.

The strengthening of roof steel trusses is often achieved by the increase of columns section by means of joining of columns elements during welding. The welding heats the sections and develops flexural deformations. For rational strengthening, it is necessary to take into account these effects. In this connection, the authors developed the methods for calculation of welded deflections produced when strengthening by means of increase of sections in fixed columns of roof steel trusses. These methods are based on the method of determination of welding stresses and deformations known as the «slack temperatures» method. It takes into account the main characteristics of strengthening: the existence in the strengthened elements of compression stresses developed in the result of load, several longitudinal welding seams, and section complexity. These methods are based on the idea of thermal power division during the welding of elements depending on their thicknesses. In cases of strengthening by weld facing of each seam, the authors determined the distributions of welding stresses separately from thermal power necessary for strengthened and strengthening elements.

The procedure of calculation of welding stresses resulted from thermal power necessary for strengthening elements is the same as their calculation procedure in the unstressed element. When calculating stresses from thermal power necessary for the base elements, the authors take into account the compression stresses from the load.

The torques and, consequently, the column welding deflections are determined according to the mutual actions of shrinkage forces originated in the strengthened and the strengthening elements.

The obtained technique of calculation became the basis for the proving of welding technologies allowing strengthening of columns of steel angle trusses during any forcing, including the maximum permissible computed values, and considerably (up to 30%) increase the effect from the strengthening (in comparison with the traditional technologies).

The authors developed the procedure of quantitative assessment of grinding burns on the base of digital technologies. This procedure includes three steps: macrophotography of original surface in the reflected light rays; its digitization using Adobe Photoshop CS6 13.1.2 software and its conversion in the form of raster images of different colours. The advantages of this method are: low labor input, environmental safety and the possibility of wide use for any scientific purpose and in any industrial conditions. It was tested within the pendulum grinding of flat parts made of 30ChGSA hardened steel (σ_UST=1080 MPa, δ_E=10%). The parts were ground by different against grains, hardness and porosity wheels: 25AF46K10V5-PО3, 25AF46L10V5-КF35, (92A, 25A)F46L6V24, 25AF46M12V5-PО3, EKE46K3V.

To prove the reliability of this innovative technology of grinding burns assessment, the authors carried out the study of parts microhardness. Taking into account the stochastic nature of grinding, to process the observation results on both grinding output parameters, the authors used the statistical methods which are divided into parametric and nonparametric (in particular, the rank methods). Statistical methods are. The advantages of these methods are the possibility of taking statistical decisions with the given reliability, as well as the assessment of cutting wheels ability not only according to the position measures (averages, medians), but also according to the measures of dispersion: deviations standards, ranges and quartile latitudes. The measure of one-dimension latitudes dispersion is more important while grinding essential parts on pre-set machines to reduce the probability of rejected parts. The study showed that in the conditions of homoscedasticity and normality of distributions violations, it is necessary to use the non-parametric method, wherein the medians and quartile latitudes are used as one-dimensional frequency distributions. The authors revealed the correlation between the position measures for burn density and microhardness while grinding by abrasive wheels using the mode: v_c=35 m/s, s_lo=7 m/min, s_tr=1 mm/double pass, t=0,015 mm, z=0,15 mm, when the increase of burns is accompanied by the reduction of 30ChGSA parts microhardness. The best results according to the position measures were shown by 25AF46K10V5-PО3 wheel, and according to the grinding accuracy - 25AF46L10V5-КF35 wheel.

The application of ultrasonic vibrations power is the promising direction of the grinding process efficiency improvement. To estimate the work conditions of grinding wheel and the quality parameters of the surface layer of a blank part, it is necessary to know local temperatures. However, the analytical research of local temperatures when grinding with ultrasonic vibrations is not carried out.

The goal of this research is the determination of vibrations parameters influence on the temperature field of grinding process.

The research objectives are: the development of physical and mathematical models for calculation of temperature field, methodology, algorithm and software for temperatures calculation, temperature numerical simulation.

Scientific novelty: it is the first analytical research of temperature field when grinding with ultrasonic activation.

The authors developed physical and mathematical models for calculation of temperature field while grinding that take into account the alteration of kinematics of abrasive grains micro-cutting and the mechanical properties of blank part material while grinding with ultrasonic activation, and the parameters dependences characterizing blank part material dispersion resistance and thermophysical properties of interacting objects materials (abrasive grain, blank part, chippings, environment) on the temperature. The simulation is carried out on the basis of joint solution of thermal conductivity differential equations written for each interacting object. To calculate equations, the authors used the finite-elements method. The authors developed the methods and the software for temperature field calculation. The article gives the results of numerical simulation of temperatures by low vibration amplitudes slightly changing micro-cutting kinematics. By ultrasonic vibrations, the blank part temperature was by 10% lower, and the local temperatures in the zone of contact of abrasive grain with the blank part and the chippings was by 14% and 15% lower correspondingly.