scholarly journals Mathematical model of the turning process using vibration impact on the cutting tool

2020 ◽  
Author(s):  
А.Н. Синько ◽  
Т.Ю. Никонова ◽  
В.В. Юрченко ◽  
А.К. Матешов ◽  
И.А. Марченко
Keyword(s):  
Cutting Tool ◽  
Block Diagram ◽  
Numerical Data ◽  
Optimal Level ◽  
Variable Cross Section ◽  
Cutting Edge ◽  
Design Stage ◽  
Variable Cross ◽  
Turning Process

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.

scholarly journals Development of Combined Cutting Process using Water-Cooled Cutting Tool

2020 ◽  
Vol 9 (3) ◽  
pp. 329-332
Keyword(s):  
Heat Sink ◽  
High Performance ◽  
Cutting Tool ◽  
Cutting Edge ◽  
Cutting Process ◽  
Hard Materials ◽  
Cutting Zone

Technological aspects of the process of turning shafts with heating of their surfaces to temperatures below recrystallization point and simultaneous improvement of the heat sink from the cutting zone, as well as increasing stability of the cutting edge of a tool. A constructive diagram of the tool device has been developed, which allows for high-performance machining with a given quality of the surfaces of parts from hard materials on lathe equipment.

scholarly journals Determining the width of a layer cut with saws with multidirectional teeth

2021 ◽  
Vol 3 (1 (111)) ◽  
pp. 14-20
Author(s):  
Oleksandr Okhrimenko ◽  
Vyacheslav Vovk ◽  
Serhii Maidaniuk ◽  
Yuliia Lashyna
Keyword(s):  
Dynamic Characteristics ◽  
Cutting Tool ◽  
Tool Design ◽  
Cutting Edge ◽  
Cutting Process ◽  
Design Stage ◽  
The Real ◽  
Size And Shape ◽  
Generating Method ◽  
Circular Saws

To predict the workability of a tool structure at the design stage, it is necessary to calculate the parameters of the cut layer when this tool is used because the cut layer’s size determines the strength and dynamic characteristics of the cutting process. It is known that the size and shape of the cut layer are affected by the allowance cutting scheme embedded in the tool design. Therefore, the parameters of the cut layer with the tool must be investigated taking into consideration the actual shapes and location of the cutting edges of the tool teeth and the cutting scheme with individual teeth. Existing analytical dependences on determining the thickness of the cut layer do not take into consideration the group arrangement of the teeth, which have a different shape and location of their cutting edges. Therefore, a procedure for determining the thickness of the cut layer analytically has been proposed, using the example of circular saws with multidirectional teeth while taking into consideration the patterns in the arrangement of the cutting edges of individual teeth and the real movements of the tool during its operation. The proposed procedure makes it possible to determine the parameters of the layer cut with the tool at both constant and progressive allowance cutting schemes. One can also specify the parameters of the cut layer at any time of the tool’s operation and analyze the change in the shape of the slice in time. Based on the analysis of the parameters of the cut layer, it has been established that saws with multidirectional teeth do not work with the entire width of the cutting edge but only in its part, whose share does not exceed 55 % of the width of the tool. The procedure reported here could be used to determine the loading of the cutting tool part with a more complex cutting scheme, which also includes tools that are operated by the form-generating method

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
Keyword(s):  
Surface Layer ◽  
Complex Shape ◽  
Variable Cross Section ◽  
Variable Cross ◽  
Optimal Processing ◽  
Complex Design ◽  
Hardening Treatment ◽  
Processing Modes ◽  
Vibration Impact

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.

scholarly journals Robot trajectory optimization control of braiding for three-dimensional complex preforms

2021 ◽  
Vol 16 ◽  
pp. 155892502110432
Author(s):  
Xinfu Chi ◽  
Qiyang Li ◽  
Hongxia Yan ◽  
Sun Yize
Keyword(s):  
Trajectory Optimization ◽  
Control Method ◽  
Three Dimensional ◽  
Great Influence ◽  
Variable Cross Section ◽  
Variable Cross ◽  
Robot Trajectory ◽  
Optimization Control ◽  
Braiding Angle

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.

scholarly journals Computing of the Theoretical Value of Roughness Parameter Rz when Turning with Helical Cutting Edge

2016 ◽  
Vol 13 (2) ◽  
pp. 9-10
Author(s):  
Michal Šajgalík ◽  
Anton Martikáň ◽  
Andrej Czán ◽  
Jozef Pile ◽  
Jozef Holubják ◽  
...  
Keyword(s):  
Roughness Parameter ◽  
Cutting Parameters ◽  
Cutting Edge ◽  
Turning Process ◽  
Kinematic Parameters ◽  
Machined Surface ◽  
Mathematical Formula ◽  
Geometric Characteristics

Abstract This article describes process of computing and identifying of the value of roughness parameter Rz deduced from basic kinematic and geometric characteristics of turning technology of machining with tool with helical cutting edge. The final mathematical formula is deduced from graphic sketch of turning process and consequently identified using all the known geometric and kinematic parameters. This formula can be used to theoretic evaluation of geometric and cutting parameters influence on the quality of machined surface determined by roughness characteristic of theoretic parameter Rz.

Cutting Edge Preparation by Means of Abrasive Brushing

2010 ◽  
Vol 438 ◽  
pp. 1-7 ◽  
Author(s):  
Berend Denkena ◽  
Luis de Leon ◽  
E. Bassett ◽  
M. Rehe
Keyword(s):  
Tool Life ◽  
Cutting Tool ◽  
Market Competition ◽  
Cutting Edge ◽  
Production Costs ◽  
Tool Performance ◽  
Process Reliability ◽  
Cutting Edge Preparation ◽  
Edge Preparation

The need for new cutting tool technologies is driven by the constantly increasing performance of machine tools and the rising market competition. Current research results show that an improved combination of the cutting edge macro- and microgeometry, together with an appropriate substrate and coating, leads to a significant enhancement of cutting tool performance. Furthermore, inappropriate cutting edge microgeometries cause, in addition to the higher production costs, a reduction of the tool life. Hence, it is essential to produce tailored cutting edge microgeometries with high precision and process reliability. This paper presents the influence of brushing process parameters on the size and the form of produced cutting edges of indexable inserts. This leads to a better understanding and higher quality of the cutting edge preparation process by means of abrasive brushes. Furthermore, the process reliability of 5-axes brushing is analyzed. An example of a tool life map presents the significantly enhanced tool performance through cutting edge preparation and its sensitivity towards varying the cutting edge microgeometry.

Dynamics of the processes in metal machining

1998 ◽  
Vol 2 ◽  
pp. 115-122
Author(s):  
Donatas Švitra ◽  
Jolanta Janutėnienė
Keyword(s):  
High Frequency ◽  
Machine Tools ◽  
Metal Cutting ◽  
Cutting Tool ◽  
Low Frequency ◽  
Metal Cutting Machine ◽  
Cutting Machine ◽  
Metal Machining

In the practice of processing of metals by cutting it is necessary to overcome the vibration of the cutting tool, the processed detail and units of the machine tool. These vibrations in many cases are an obstacle to increase the productivity and quality of treatment of details on metal-cutting machine tools. Vibration at cutting of metals is a very diverse phenomenon due to both it’s nature and the form of oscillatory motion. The most general classification of vibrations at cutting is a division them into forced vibration and autovibrations. The most difficult to remove and poorly investigated are the autovibrations, i.e. vibrations arising at the absence of external periodic forces. The autovibrations, stipulated by the process of cutting on metalcutting machine are of two types: the low-frequency autovibrations and high-frequency autovibrations. When the low-frequency autovibration there appear, the cutting process ought to be terminated and the cause of the vibrations eliminated. Otherwise, there is a danger of a break of both machine and tool. In the case of high-frequency vibration the machine operates apparently quiently, but the processed surface feature small-sized roughness. The frequency of autovibrations can reach 5000 Hz and more.

Boundary element method in numerical study of three-dimensional Stokes flows in channels of arbitrary shape

2012 ◽  
Vol 9 (1) ◽  
pp. 94-97
Author(s):  
Yu.A. Itkulova
Keyword(s):  
Boundary Element Method ◽  
Boundary Element ◽  
Cross Section ◽  
Numerical Study ◽  
Three Dimensional ◽  
Cylindrical Tube ◽  
Variable Cross Section ◽  
Variable Cross ◽  
Periodic Flows ◽  
Element Method

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.

Longitudinal oscillation of a rod with a variable cross section

2019 ◽  
Vol 14 (2) ◽  
pp. 138-141
Author(s):  
I.M. Utyashev
Keyword(s):  
Cross Section ◽  
Natural Frequencies ◽  
Liouville Problem ◽  
Variable Cross Section ◽  
Variable Cross ◽  
Longitudinal Vibrations ◽  
Cross Sectional ◽  
Independent Functions ◽  
The Cross ◽  
The Right

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.

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