scholarly journals Technological tests of a multi-seat device for vibro-shock processing of long parts of complex shape

2021 ◽  
Vol 2131 (5) ◽  
pp. 052018
Author(s):  
Nikolay Koval ◽  
Ivan Vyalikov ◽  
Rustam Khubiev ◽  
Yulia Karagodskaya

Abstract The article deals with the issues related to the possibility of ensuring the indicators of quality of long complex-shaped parts by using vibration-impact processing in the technological process of their manufacturing using a special multi-seat device. The analysis of the design of representatives of long parts and the requirements for the quality of their surface layer, as well as the operational properties, made it possible to formulate the basic requirements for the design of multi-seat tools and develop a prototype for technological tests. The device allows processing two fragments of long parts and was used to establish the possibility of processing full-sized products and to establish optimal processing modes. Elements of the helicopter spars, which have the most complex design in the class of the considered parts, were used as fragments. Particular attention is paid to the processing of the inner surface of a complex shape and variable cross-section. The test results showed the possibility of using a multi-seat device for vibration-impact hardening treatment, which ensures the achievement of the specified parameters of the surface layer: surface roughness and microhardness with high process productivity.

Author(s):  
А.Н. Синько ◽  
Т.Ю. Никонова ◽  
В.В. Юрченко ◽  
А.К. Матешов ◽  
И.А. Марченко

В статье авторами проведено математическое моделирование процесса точения с использованием волнового воздействия на режущий инструмент. Установлены зависимости между видом образующейся стружки и качеством обработанной поверхности от интенсивности вводимых в зону резания колебаний, а также численные данные параметров режима резания. Авторами установлено, что существует определенный оптимальный уровень колебаний, при котором наблюдается максимальная стойкость инструмента, повышение производительности и улучшение качества обработанной поверхности. Данные зависимости позволяют разработать структурную схему и последовательность проектирования операций с применением вибрационного точения. Для данного процесса авторами установлен оптимальный уровень интенсивности колебаний применительно к инструментам, оснащенным твердым сплавом, при обработке конструкционных и высоколегированных материалов. Практической значимостью работы является получение математических моделей о процессе точения с использованием вибрационного воздействия на режущий инструмент, на основании которых были получены данные и созданы прототипы режущих инструментов для применения в аппаратах вибрационного точения. Основной методикой получения математических данных о вибрационном воздействии на режущий инструмент является обобщение многочисленных экспериментальных данных, а также проведение исследования с помощью программ твердотельного проектирования. В результате исследований получены параметрические уравнения, позволяющие на стадии проектирования прогнозировать и описывать траекторию движения режущей кромки резца при вибрационном воздействии на режущий инструмент. Получены графические схемы траектории перемещения режущей кромки инструмента, демонстрирующие переменное сечение срезаемого слоя при вибрационном воздействии на режущий инструмент. The purpose of this work is to obtain mathematical data about the turning process using vibration effects on the cutting tool. The main method for obtaining mathematical data on the vibration effect on the cutting tool is to generalize numerous experimental data, as well as conducting research using solid-state design programs. In the course of the work, mathematical modeling of the turning process was carried out using the wave effect on the cutting tool. The dependences between the type of chips formed and the quality of the treated surface on the intensity of vibrations introduced into the cutting zone, as well as numerical data on the parameters of the cutting mode, are established. It has been established that there is a certain optimal level of oscillation at which the maximum tool life, increased productivity and improved quality of the treated surface are observed. These dependencies allow you to develop a block diagram and design sequence for the vibration turning operation. For vibration turning, the optimal level of vibration intensity is set for tools equipped with a hard alloy when processing structural and high-alloy materials. The obtained parametric equations make it possible to predict and describe the trajectory of the cutting edge of the cutter at the design stage when the cutting tool is vibrated. Graphic diagrams of the trajectory of the cutting edge of the cutting tool are obtained, showing a variable cross-section of the cut layer under vibration action on the cutting tool. In this work, the regularities of vibration turning during turning are shown. On the basis of which practical data were obtained and prototypes of cutting tools for use in vibration turning devices were created.


2016 ◽  
Vol 22 (2) ◽  
pp. 128 ◽  
Author(s):  
E.L. Zhukov ◽  
I.I Kozar ◽  
D.Yu. Kolodyazhniy

<p>We consider the study results of the hard-to-process titanium-based alloys processing on turning lathes. The influence made on quality of the surface layer, characterized by the amplitude roughness parameters, by geometry, cutting tool properties, processing modes and dimensional  wear is considered.</p>


2021 ◽  
pp. 53-62
Author(s):  
Юрій Анатолійович Шашко ◽  
Олексій Володимирович Кулик ◽  
Роман Федосійович Максимчук ◽  
Анатолій Федорович Санін

The creation of complex structural elements of aircraft using is promising and is widely used since such elements have several structural and technological advantages over the manufacture of parts using classical technologies. However, it requires the solution of several scientific and technical problems to obtain products of high accuracy and roughness, the development of a technological process, the development of processing modes, and sometimes the development of a new design of products. For the development of technologies in modern rocketry, improving the quality and accuracy of the production of turbines of turbopump units, an important task is to search for new and improve existing technological solutions for the manufacture of such parts with high surface quality. The work aimed to analyze the existing processing methods for parts of turbopump units with complex geometry and select the most technologically advanced one for further use in technological processes. The objective of this article is an analytical review of existing methods of surface treatment of critical parts and the selection of the most technologically advanced method for finishing the blades of a closed-type turbine (with a shroud) to reduce the roughness and improve the quality of the working surface. The object of the research is the process of machining a segment of a turbine impeller made of Inconel 718 nickel alloy (domestic analog – alloy HN45MVTJuBR), which is a key element of a turbopump unit. The blank part of the turbine monowheel type was made using 3D printing technology. As a result of the work, the optimal processing method was chosen, namely, the DryLyte dry electrochemical polishing technology, which has quite significant advantages in comparison with illogical methods. This method has been tested experimentally and is being actively implemented abroad. To introduce this DryLyte technology, it is necessary to carry out additional experiments on finishing the inner channels of small size (24 mm) using the example of interscapular channels of turbines, which will make it possible to fully assess the capabilities of the technology.


2021 ◽  
Vol 16 ◽  
pp. 155892502110432
Author(s):  
Xinfu Chi ◽  
Qiyang Li ◽  
Hongxia Yan ◽  
Sun Yize

The quality of composite preform has great influence on its mechanical properties. Aiming at the problems of difficulty in robot teaching and unstable braiding angle in the process of braiding three-dimensional complex component, a control method of robot is proposed. Firstly, the mandrel is discretized to ensure that the axis of each discrete mandrel is perpendicular to the braiding point plane, and the orientation and direction of the tool center are calculated. Then, the take-up speed of the robot is calculated, so that the self-adjustment of the braiding angle can be realized in the braiding process. The experimental results show that the control method can effectively reduce the braiding angle error of variable cross-section mandrel within 2°, and can improve the quality of composite products in actual production.


2012 ◽  
Vol 9 (1) ◽  
pp. 94-97
Author(s):  
Yu.A. Itkulova

In the present work creeping three-dimensional flows of a viscous liquid in a cylindrical tube and a channel of variable cross-section are studied. A qualitative triangulation of the surface of a cylindrical tube, a smoothed and experimental channel of a variable cross section is constructed. The problem is solved numerically using boundary element method in several modifications for a periodic and non-periodic flows. The obtained numerical results are compared with the analytical solution for the Poiseuille flow.


2019 ◽  
Vol 14 (2) ◽  
pp. 138-141
Author(s):  
I.M. Utyashev

Variable cross-section rods are used in many parts and mechanisms. For example, conical rods are widely used in percussion mechanisms. The strength of such parts directly depends on the natural frequencies of longitudinal vibrations. The paper presents a method that allows numerically finding the natural frequencies of longitudinal vibrations of an elastic rod with a variable cross section. This method is based on representing the cross-sectional area as an exponential function of a polynomial of degree n. Based on this idea, it was possible to formulate the Sturm-Liouville problem with boundary conditions of the third kind. The linearly independent functions of the general solution have the form of a power series in the variables x and λ, as a result of which the order of the characteristic equation depends on the choice of the number of terms in the series. The presented approach differs from the works of other authors both in the formulation and in the solution method. In the work, a rod with a rigidly fixed left end is considered, fixing on the right end can be either free, or elastic or rigid. The first three natural frequencies for various cross-sectional profiles are given. From the analysis of the numerical results it follows that in a rigidly fixed rod with thinning in the middle part, the first natural frequency is noticeably higher than that of a conical rod. It is shown that with an increase in the rigidity of fixation at the right end, the natural frequencies increase for all cross section profiles. The results of the study can be used to solve inverse problems of restoring the cross-sectional profile from a finite set of natural frequencies.


Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 772
Author(s):  
Xianming He ◽  
Dongxiao Li ◽  
Hong Zhou ◽  
Xindan Hui ◽  
Xiaojing Mu

The piezoelectric vibration energy harvester (PVEH) based on the variable cross-section cantilever beam (VCSCB) structure has the advantages of uniform axial strain distribution and high output power density, so it has become a research hotspot of the PVEH. However, its electromechanical model needs to be further studied. In this paper, the bidirectional coupled distributed parameter electromechanical model of the MEMS VCSCB based PVEH is constructed, analytically solved, and verified, which laid an important theoretical foundation for structural design and optimization, performance improvement, and output prediction of the PVEH. Based on the constructed model, the output performances of five kinds of VCSCB based PVEHs with different cross-sectional shapes were compared and analyzed. The results show that the PVEH with the concave quadratic beam shape has the best output due to the uniform surface stress distribution. Additionally, the influence of the main structural parameters of the MEMS trapezoidal cantilever beam (TCB) based PVEH on the output performance of the device is theoretically analyzed. Finally, a prototype of the Aluminum Nitride (AlN) TCB based PVEH is designed and developed. The peak open-circuit voltage and normalized power density of the device can reach 5.64 V and 742 μW/cm3/g2, which is in good agreement with the theoretical model value. The prototype has wide application prospects in the power supply of the wireless sensor network node such as the structural health monitoring system and the Internet of Things.


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