Improving the processing accuracy of the valve seats of internal combustion engines using diagnostic measurements

© Published under licence by IOP Publishing Ltd. Currently, the main tool of quality management at the enterprises of various industries are statistical methods of quality management. In the literature, mostly on examples of the successful application of control charts for dimensions. More sophisticated measures of quality details not given. The article illustrates a practical application of control charts applied to technologically sophisticated measure of the accuracy of the key indicator affecting the operation of the engine - radial runout of valve seat cylinder head. Data of measurements made in accordance with the standard metrological definitions are processed in the software product "Attestator". As a result, identify the potential percentage of possible marriage, revealed the existence of special reasons to change the values of individual indicators, the index of reproducibility and stability of the process, the decision about the certification process, but the factors of the process that need to be addressed to improve the quality of the products is not revealed. A universal methodology consisting of four steps, the implementation of which allows to develop such a scheme of measurement, which significantly improves the search performance of important technological factors. For example, the same technological operations and the accuracy rate shows the application of the methods. The result of the survey revealed two main factors of the process is bending of the boring bar and the error of the satellite-based suppression will significantly improve the quality of manufacturing of parts

Technique for monitoring the indicators of the total contact spot of spur gears of the truck's differential gear

© Published under licence by IOP Publishing Ltd. The article contains the main provisions of the technique, which allows to control the area of the total contact patch and its position relative to the tooth edges. Graphical schemes for finding indicators are given. An example of the calculation of the indicators established by the methodology, as well as the results of its application for assessing the quality of the setup performance, is considered on the example of processing a differential satellite in the operation of circular gearing

Data-adaptive harmonic spectra and multilayer Stuart-Landau models

Harmonic decompositions of multivariate time series are considered for which we adopt an integral operator approach with periodic semigroup kernels. Spectral decomposition theorems are derived that cover the important cases of two-time statistics drawn from a mixing invariant measure. The corresponding eigenvalues can be grouped per Fourier frequency, and are actually given, at each frequency, as the singular values of a cross-spectral matrix depending on the data. These eigenvalues obey furthermore a variational principle that allows us to define naturally a multidimensional power spectrum. The eigenmodes, as far as they are concerned, exhibit a data-adaptive character manifested in their phase which allows us in turn to define a multidimensional phase spectrum. The resulting data-adaptive harmonic (DAH) modes allow for reducing the data-driven modeling effort to elemental models stacked per frequency, only coupled at different frequencies by the same noise realization. In particular, the DAH decomposition extracts time-dependent coefficients stacked by Fourier frequency which can be efficiently modeled---provided the decay of temporal correlations is sufficiently well-resolved---within a class of multilayer stochastic models (MSMs) tailored here on stochastic Stuart-Landau oscillators. Applications to the Lorenz 96 model and to a stochastic heat equation driven by a space-time white noise, are considered. In both cases, the DAH decomposition allows for an extraction of spatio-temporal modes revealing key features of the dynamics in the embedded phase space. The multilayer Stuart-Landau models (MSLMs) are shown to successfully model the typical patterns of the corresponding time-evolving fields, as well as their statistics of occurrence.Comment: 26 pages, double columns; 15 figure

The method of diagnosing machine systems by measuring the accuracy of manufactured parts

© Published under licence by IOP Publishing Ltd. The main provisions of the technique allowing to create a diagnostic complex of the technical state of the machine system, which is informative at the same time of several diagnostic complexes - geometrical accuracy, strain gauge, technological accuracy, the influence of technological heredity - are revealed

Development of the design of a laboratory vibro-grinding machine for preparing samples for metallographic research

© Published under licence by IOP Publishing Ltd. The article presents the results of testing a prototype vibro-grinding laboratory machine for making samples for metallographic examination. The effectiveness of the method and its suitability for the preparation of thin sections during laboratory studies in the discipline "Material Science" have been established

Rapid assessment of wear-resistant tool coatings

© 2017, Allerton Press, Inc. The operation of a cutting wedge is studied in order to improve coating application on tools. A method of investigating the coating characteristics in plant conditions is outlined. The mechanisms of coating failure in cutting are established. The blunting of tools in the course of operation is analyzed. Coating application is optimized

Bit for the core drilling of nonmetals

© 2015, Allerton Press, Inc. The design of tools for core drilling is considered, along with their applicability. The deficiencies of existing designs when machining composites and wood are analyzed, including flaking and scratching on the machined surface. A tool design with group teeth is proposed. This design effectively cuts fibers and permits chip removal. A benefit of the new tool design is improved quality of the machined surface

Regulation of Geometrical Parameters Deviations of Automotive Components Parts through Diagnostic Measurements Organization

© 2017 The Authors. Published by Elsevier Ltd. Standard quality management methods are too laborious to apply them to compact business suppliers of automotive components. Analysis of the existing methods for equipment diagnosing was carried out and their shortcomings were revealed. There is a need for special high-precision instruments, the need for stopping equipment and a dismantling clamping set-up. The article offers a method for error diagnostics in the technological system position modules from the values of the performance precision machined parts with the instrument for height measuring directly at the workplace. This method significantly reduces the time necessary to plan corrective actions and risk of poor performance. The article contains the example of application of the "brake pad" detail measurement technique for corrections of the technological system modules

Durable grinding head for universal machines

© 2017, Allerton Press, Inc. A grinding head has been developed for a universal grinding machine. Operational tests confirm its long life and high performance

Recombination dramatically speeds up evolution of finite populations

We study the role of recombination, as practiced by genetically-competent bacteria, in speeding up Darwinian evolution. This is done by adding a new process to a previously-studied Markov model of evolution on a smooth fitness landscape; this new process allows alleles to be exchanged with those in the surrounding medium. Our results, both numerical and analytic, indicate that for a wide range of intermediate population sizes, recombination dramatically speeds up the evolutionary advance