Bulletin PNRPU. Mechanical engineering, materials science

Proposed graph-analytical method for evaluating overall and mass characteristics of pipes intended, depending on the applied external periodically recurring concentrated load-bending forces or torque. Some aspects of a preliminary assessment of the strength of thick-walled and thin-walled pipes on the basis of the proposed approach. Used method for assessing the resistance of the material of non-circular section of the pipe, the external profile of the conditions of strength in the dangerous section. According to the calculation results constructed a graph of the relative section modulus to bending of the relative thickness of both circular and noncircular cross section that can be applied for further design or processing variable profile along the length of the tubes. We offer some suggestions for further study the structural strength of the pipe, heavy duty load or experiencing a sharp increase in internal pressure once using data on the dimensions and weight characteristics. A comparative analysis of the evaluation of the effect of the internal pressure in the pipe wall is normal to the longitudinal axis of the most frequently used for the calculation of the greatest theories of linear deformation, the largest shear stresses, the specific energy of forming relative safety factor.

Technology development is impossible without quality control. Widespread use of machine tools with numerical control in manufacturing increased the demand for used tools of control, an adequate response was the use in the control of coordinate measuring machines (CMMS). Modern KIM presents a wide range of models, allowing you to choose the machine according to solve measuring tasks, conditions (temperature, pressure, humidity, dustiness) and financial capabilities of the enterprise. The paper describes the current coordinate measuring machine that allows you to measure any part you need by checking the size of the forms of products. Describes the strategy dimension of the housing part on a coordinate measuring machine Carl Zeiss Contura G2. To businesses using KIM, there is no reasonable measurement strategies that allow to achieve an optimal balance between accuracy metrics measure the performance of control. The aim of this work is to develop a measurement strategy donovich dimensions of the housing part, which provides the ratio of the accuracy metrics for performance measurement monitoring. Measurements donovich dimensions of the housing part by three methods of measurement (4 points, 8 points and Polyline method), recorded the time of measurement and control accuracy parameter. The analysis of the obtained results. The analysis of modern coordinate measuring machines. It is shown that the use of CMM improves the performance and accuracy of control. Modern KIM allow you to control parts of any shape and size. The developed technology contact measurement method for prismatic parts on CMM Carl Zeiss Contura G2, providing the optimal balance of accuracy for performance monitoring. Found that the most productive method is to measure on the strategy of "Polyline". The time control is 15 seconds.

One of the important tasks is to ensure that the requirements of dimensional accuracy, form and position of surfaces in the processing of technically complex parts. Object of research are the details of complex surfaces, such as crankshafts and camshafts, turbine blades and body parts with lots of holes, complex body parts, for example, a cylinder block of an internal combustion engine, dies, molds, gears, and car bodies. Geometry of complex parts due to their functional purpose, thus, control of complex surfaces must be based on the requirements of the Assembly of all parts in General. In today's highly automated production measurement of complex parts on coordinate measuring machines (CMMS) is of great importance, there is an urgent need to establish the feasibility of control. The aim of this work is the formation of the most appropriate methods of measurement, which will be monitored technically complex surfaces of parts and development of mathematical models for automated evaluation of the results. The proposed method of coordinate measurement includes measurement strategy (recommended number of outlets, their location on a controlled surfaces and sequence of bypass (trajectory)), also a set of computational models that describe mathematically the relationship of the coordinates of the measured points with a defined linear and angular parameters. Initially in accordance with the specified measurement procedure in manual or automatic cycle, measure the coordinates of the separate points belonging to the real surfaces of the test object. Movements are programmed in the coordinate system of the part (SCD), formed by its bases. Primary SCD is tied to the coordinate system CMM (SCM) using mathematical based. This procedure involves the calculation of the location of the coordinate system in pre-measured points in the SCM basic elements and the subsequent transformation of coordinates of points of the other elements of SCM in SCD. When developing measurement techniques necessary given the number of points for each of the measured surface, it must be the optimal number. Further, in the second stage, the settlements of a given size, deviations of form and position of surfaces with the help of the developed complex mathematical models. The results of this work presents a set of mathematical models and algorithms for control of geometrical characteristics of products on mobile CMM. The advantages of the proposed methods compared to the standard. Defined the field of efficient use of mobile CMM in the control of technically complex surfaces. A new method of coordinate measurement for parts with complex surfaces, enabling control of the data surfaces with fewer points compared with the recommendations of the known manufacturers of coordinate machines, designed to improve the performance of control operations, and to increase the accuracy of the evaluation of the measurement results.

Today large volume of application of manual arc welding by the covered electrodes remains. Application of this way of welding for performance of the repair and recovery work connected with correction of the defects of welding arising at production of a metalwork is especially actual. In these conditions ensuring high stability of burning of an arch is especially actual. In recent years considerably the volume of the researches connected by creation of the new welding materials providing higher welding and technological properties of new electrodes such as stability of burning of an arch, stability of repeated excitement of an arch, ecological indicators, etc. increased. However the existing methods of an assessment of properties of electrodes not always provide possibility of the analysis of influence of structure of a covering on stability of burning of an arch. So the majority of the existing techniques of an assessment of stability of burning of a welding arch are oriented on welding on alternating current and don't allow to estimate influence of structure of a covering of electrodes on stability of burning of a welding arch. In this regard development of the techniques of an assessment of stability of burning of an arch allowing to investigate influences of components of an electrode covering on welding technical characteristics on an electrode for creation of welding materials with the increased level of properties is actual. The researches of stability of burning of a welding arch of a direct current conducted on Department “Welding Production and Technology of Structural Materials”, Perm National Research Polytechnic University provide the analysis of dynamic characteristics of welding current and tension on an arch which is written down in memory of the personal computer with use of special information and measuring system. For the purpose of an exception of casual indignations of the experiments caused by a human factor for carrying out the welding ADS-1000-2 machine gun of system of automatic control of tension of an arch in which the electrode wire was replaced with a bar with an electrode clip on the end for welding by the covered electrodes is used. At the time of welding the studied electrodes carry out record of welding current and tension of an arch which fluctuations characterize change of resistance of an arc interval that is connected with stability of burning of an arch, nature of transfer of metal, existence of short circuits and, in general, with stability of all process. The subsequent mathematical processing of dynamic characteristics of a welding arch allows to estimate stability of burning welding arches on the basis of variation coefficient. Besides this technique allowed to reveal and quantitatively to estimate influence like the power supply of an arch and structure of a covering of an electrode on stability of process of welding.

In given clause it is underlined, that the main problem broaching is application broach from fast-cutting steel and the limited speeds of cutting. The analysis of literary data shows, that the insufficient attention is paid to this question. The general analysis of works has shown, that the majority of works is executed in laboratory conditions, on samples of processable materials, on machine tools-stands and has the recommendatory character which is not considering concrete industrial and specifications, the sizes and a configuration of processable details, capacity and rigidity of the applied equipment, etc. Offered variants have the merits and demerits. Application broaches from fast-cutting steel limits process broaching to the maximal speed of cutting v = 1,5…2 m/mines. Broach with brazed carbide plates have following lacks: Deterioration of one tooth leads grinding all teeth or the rejection to all broach, presence of residual pressure in plates after soldering and grinding teeth. The decision of problems modern broaching is application assorted broaches with replaceable carbide plates. As a result of experiment the optimum method of fastening carbide plates on broach is found. The given decision allows to design and make broach with processing the lock simultaneously with fave the parties.