IMPROVING THE EFFICIENCY OF FINISHING MILLING OF CONCAVE SURFACES ON SMALL-SIZED CNC MACHINES

2021 ◽  
pp. 92-97
Author(s):  
А.М. Козлов ◽  
Г.Е. Малютин ◽  
Е.А. Малявин ◽  
А.А. Козлов
Keyword(s):  
Metal Cutting ◽  
Low Cost ◽  
Cutting Depth ◽  
Ferrous Metals ◽  
Cutting Equipment ◽  
Processing Accuracy ◽  
Increase Productivity ◽  
Spatial Shape ◽  
Cad Tool ◽  
Cutting Modes

Pазвитие систем ЧПУ современного полногабаритного металлорежущего оборудования дало возможность корректировать режимы резания, например, величину рабочей подачи непосредственно в процессе обработки. Однако на производстве имеется значительная часть деталей, которые по своим габаритам экономически невыгодно обрабатывать на дорогостоящих крупных станках, имеющих мощную систему ЧПУ. Поэтому на предприятиях все большее применение получают относительно недорогие малогабаритные металлорежущие станки. Технологические возможности такого оборудования позволяют обрабатывать не только цветные металлы и сплавы, но и стали. Особенностью управления таким оборудованием является использование упрощенных систем ЧПУ, установленных на персональных компьютерах, которые не имеют возможности выполнять арифметические операции, и это становится препятствием для повышения производительности обработки сложных поверхностей. В то же время из-за своей простоты и низкой стоимости эти системы становятся все более востребованными. Предлагается повысить производительность обработки поверхностей сложной пространственной формы на основе расчета движения инструмента САПР системой путем преобразования реальной траектории в набор симметричных отрезков с известными координатами. Этот метод позволяет при заданной точности обработки установить значения параметров режима резания, близкие к оптимальным, исключить аварийные ситуации, связанные с выходом из строя инструмента при работе с переменной глубиной резания, сформированной после черновой обработки, и повысить производительность на 15-20% The development of CNC systems of modern full-sized metal-cutting equipment made it possible to adjust cutting modes, for example, the value of the working feed, directly during processing. However, there is a significant number of the parts in production that, according to their dimensions, are economically unprofitable to process on expensive large machines with a powerful CNC system. Therefore, relatively inexpensive small-sized metal-cutting machines are becoming increasingly used in enterprises. The technological capabilities of such equipment allow processing not only non-ferrous metals and alloys but also steels. A feature of the control of such equipment is the use of simplified CNC systems installed on personal computers that are not able to perform arithmetic operations and this becomes an obstacle to improving the productivity of processing complex surfaces. At the same time, due to their simplicity and low cost, these systems are becoming more and more popular. In the article, we proposed to increase the productivity of processing surfaces of complex spatial shape on such machines based on the calculation of the CAD tool movement by the system by converting the real trajectory into a set of symmetrical segments with known coordinates. This method allows you, with a given processing accuracy, to set the values of the cutting mode parameters close to the optimal ones, to eliminate emergencies associated with tool failure when working with a variable cutting depth formed after roughing and to increase productivity by 15-20%

Influence of Structural Parameters of Cutting Ceramics on Quality of Processing of Machine Slideways of Metal-Cutting Equipment in Selective Formation of Instrumentation

2020 ◽  
Vol 854 ◽  
pp. 64-73
Author(s):  
Ilya V. Gorshkov ◽  
M.A. Popov
Keyword(s):  
Metal Cutting ◽  
Structural Parameters ◽  
Machining Process ◽  
Cutting Ceramics ◽  
Cutting Equipment ◽  
Priority Method ◽  
Increase Productivity ◽  
Carbide Ceramics ◽  
Selective Formation

Modern methods of machining of bed slideways with the required parameters of accuracy and quality of the processed surfaces are considered in order to increase productivity in the treatment of the surface of machine stands. To improve productivity, the finishing sanding operation has been replaced with finishing milling to ensure the required roughness, flatness and parallelism. The method of replacement of technological operations as exemplified by processing of a bed made of gray cast iron of grade “СЧ-20” is studied. The priority method of increasing the productivity of the processing of machine slideways of metal-cutting equipment, based on the use of cutting ceramics during the processing of the bed as a final technological operation, is determined. Based on the microstructural characteristics of oxide-carbide cutting ceramics, a uniform method of equipping cutters with cutting inserts with equal lifespan is used to increase productivity and achieve the required surface finish. This method of the milling cutter layout allows for longer life and provides the required margin of tool accuracy as well as allows predicting premature wear of the cutting tool. The results of the work are the identification of the patterns of influence of structural parameters of cutting ceramics on the quality of machine slideways of metal-cutting equipment in the selective formation of instrumentation. Studies have shown that the quality of machining depends on the microstructure characteristics of each insert used in the machining process when using interchangeable multi-sided oxide carbide ceramic inserts. The increase in productivity and quality of machining is achieved by monitoring the microstructure of the cutting oxide-carbide ceramics.

scholarly journals Modelling of layer-by-layer metal removal in the digital twin of the round grinding process performed on CNC machines

2020 ◽  
Vol 329 ◽  
pp. 03047
Author(s):  
Aleksandra Akintseva ◽  
Pavel Pereverzev ◽  
Alexander Prokhorov ◽  
Sergey Kononov
Keyword(s):  
Metal Removal ◽  
Control Program ◽  
Layer By Layer ◽  
Cutting Depth ◽  
Positioning Systems ◽  
Digital Twin ◽  
Processing Accuracy ◽  
Grinding Machines ◽  
Variable Compliance ◽  
Cutting Modes

Parts’ processing on circular grinding machines is carried out according to the specified stepwise control cycles of radial and axial feeds, which are laid down in the control program (CP). Despite the precise positioning systems, modern CNC circular grinding machines have a variable compliance of the technological system along the processing length. It causes different cutting depth and occurrence of various errors in dimensions of the diametric surface. Also, the dimensions error increases due to the fact that the processing of parts batch is carried out in unstable conditions and under the influence of different variable factors, which can include allowance fluctuation, blunting of the wheel grains, changes of the wheel diameter and the contact area of the wheel with the workpiece, etc. However, there are still no means of control developed CP, which include cycles of cutting modes, to ensure the accuracy of parts batch` processing. This article describes the digital twin (DT) of the circular plunge grinding with CNC, which allows simulating layer-by-layer metal removal during the whole grinding cycle by calculating the cutting depth on each workpiece revolution under various combinations of unstable processing conditions and variable compliance of TS. Modeling of layer-by-layer allowance removal is performed in several sections of the treated surface; these sections have different compliance. At the end of the grinding cycle in the DT the processing accuracy is estimated on the basis of the obtained values of radii dimensions in all sections of the processed surface. The introduction of DT allows speeding up the CP development, reduce the time of launching CP in production, and increase the productivity of circular grinding operations with CNC by optimizing the cycles of the cutting modes while ensuring the specified processing accuracy.

scholarly journals CONSTRUCTION OF A REGRESSION MODEL OF THERMAL RESISTANCE OF A CONTACT PSEUDO MEDIUM

2021 ◽  
Vol 23 (3) ◽  
pp. 47-54
Author(s):  
A.F. Denisenko ◽  
◽  
L.Yu. Girth ◽  
Keyword(s):  
Thermal Resistance ◽  
Regression Model ◽  
Metal Cutting ◽  
Operating Experience ◽  
Design Stage ◽  
Contact Thermal Resistance ◽  
Limit Values ◽  
Cutting Equipment ◽  
Processing Accuracy ◽  
The Difference

The operating experience of metal-cutting machines made it possible to develop reasonable recommendations for the permissible limit values of temperature for the main subsystems of the machine, which determine the accuracy of processing. However, the decrease in the seriality of the manufactured metal-cutting equipment and the constant improvement of its designs require the development of models that are the basis of engineering techniques that allow at the design stage to predict the thermal picture of the main machine units that affect the processing accuracy. In connection with a significant number of factors influencing the formation of contact thermal resistance, and the difference in the weight of their action, it is proposed to use a pseudolayer (pseudo-medium), consisting of areas of actual contact and cavities filled with air or oil, for their comprehensive consideration in the thermal model of joining parts. To determine the significant factors that dominate the contact thermal resistance, a number of one-factor experiments were carried out. To develop a regression model of temperature change in the contact zone, a PFE of type 24 was performed. The results obtained were verified by the Cochran, Student and Fisher criteria.

Determination of Optimal Milling Modes by Means of Shock-Vibration Load Reduction on Tool and Peak-Factor Equipment

2019 ◽  
Vol 942 ◽  
pp. 87-96
Author(s):  
Alexey Gavrilin ◽  
Boris Moyzes ◽  
Kirill Kuvshinov ◽  
Maxim Vedyashkin ◽  
Olga Surzhikova
Keyword(s):  
Metal Cutting ◽  
Milling Process ◽  
General Level ◽  
Vibration Load ◽  
Peak Factor ◽  
Milling Machines ◽  
Cutting Equipment ◽  
Vibration Loads ◽  
Cutting Modes

Vibrodiagnostics of metal-cutting machines is an efficient method to increase reliability of all elements of the technological system «machine tool-device-instrument-detail». The development of vibrodiagnostic methods is especially important for milling metal-cutting machines which operate in intermittent cutting mode and are exposed to shock-vibration loads. One of the trends in the development of metal cutting equipment is to increase its productivity by expanding the ranges of cutting modes. Increase in the combination of cutting modes leads to increased probability of coincidence of the natural frequencies of the equipment and the frequencies of the cutting process which in its turn leads to operation of the machine equipment elements under resonance conditions. In the article we provide the results of our research aimed to develop the method to reduce shock-vibration load on tool and peak-factor equipment of milling machine. In our research we developed the technique that makes it possible to measure not only the general level of vibration, but also other parameters used for vibrodiagnostics, for example, the value of the peak factor has been developed. The method includes the development of a principle layout and of a plan for a three-factor experiment, construction and analysis of vibrational and spectral diagrams of the milling process for the assignment of optimal modes that provide machine operating at lower level of shock-vibration loads. Based on the results of the work we have come to the conclusion that it is rather promising to use the peak factor in analysis of the milling machines reliability.

A NEW CAD TOOL TO ANALYSIS AND SYNTHESIS OF LOW COST FUZZY CONTROLLERS

2007 ◽  
Vol 40 (1) ◽  
pp. 216-221
Author(s):  
Ihosvany Alvarez-López ◽  
Orestes Llanes-Santiago ◽  
José L. Verdegay
Keyword(s):  
Low Cost ◽  
Fuzzy Controllers ◽  
Analysis And Synthesis ◽  
Cad Tool

Assessment of the Adequacy of the Definition of Cutting Forces for the Purpose of Minimizing Energy Consumption in Machining Processes

2019 ◽  
Vol 945 ◽  
pp. 556-562
Author(s):  
A.G. Kondrashov ◽  
D.T. Safarov ◽  
R.R. Kazargeldinov
Keyword(s):  
Energy Consumption ◽  
Cutting Force ◽  
Cutting Forces ◽  
Metal Cutting ◽  
Electrical Power ◽  
Cutting Tools ◽  
Precise Determination ◽  
Machining Processes ◽  
Milling Operations ◽  
Cutting Equipment

Minimizing energy consumption in the processing of parts on metal-cutting equipment is most effective at the stage of designing the content of operations. Important in this process is the precise determination of the initial parameters - cutting forces. This parameter allows you to plan both energy consumption and perform additional calculations for the deformation of the tooling and workpiece in order to predict the geometric accuracy of the machined part. The article presents the results of experiments on measuring the circumferential cutting force during milling operations of an aluminum alloy workpiece with an end mill. The measurements were carried out by an indirect method - by recording the electrical power on the spindle and then calculating the circumferential cutting force. Theoretical analysis of the methods of calculation of cutting forces showed significant differences between the results obtained by domestic methods and recommendations of world manufacturers of cutting tools. Statistical analysis of the results of calculations based on reference data and measurements made it possible to assess the adequacy of the known methods for calculating cutting forces in order to minimize energy consumption in operations of processing parts on metal-cutting equipment

scholarly journals Methodology of designing integrated technological processes for manufacturing CNC machined parts

2018 ◽  
Vol 224 ◽  
pp. 01057
Author(s):  
Viktor I. Guzeev ◽  
Danil Yu. Pimenov
Keyword(s):  
Simulation Modeling ◽  
Metal Cutting ◽  
Cutting Tool ◽  
New Approach ◽  
Integrated Production ◽  
Technological Processes ◽  
Machined Parts ◽  
Processing Accuracy ◽  
Processing Steps ◽  
Production Conditions

The article presents a new approach to the design of technological processes of processing parts on metal cutting machines in the integrated production conditions based on the expected forecast of the parts processing accuracy. The stages of choosing the parameters of processing steps are combined with determining the parameters of the cutting tool and machining attachments by simulation modeling. The design sequence begins with the first operation.

“Thin” vs. “Fat” Client of Web-Based CAD Tools

2000 ◽  
Author(s):  
Charlie C. L. Wang ◽  
Matthew M. F. Yuen ◽  
Yu Wang
Keyword(s):  
Low Cost ◽  
Software Tools ◽  
Internet Technology ◽  
Global Network ◽  
Distributed Design ◽  
Cad Tools ◽  
Web Based ◽  
Thin Client ◽  
Cad Cam ◽  
Cad Tool

Abstract Internet technology in particular opens up another domain for building future CAD/CAM environment. This environment will be a global, network-centric environment with various members providing different software tools, manufacturing facilities, and analysis services for distributed design and fabrication. Web-based CAD tools play a prominent role in the environment. Two kinds of clients can be used to develop a web-based CAD tool now, one is “thin” client, and another is “fat” client. This paper compares the advantage of “thin” and “fat” client, and explains the advantage of using low-cost, configurable, CAD components.

scholarly journals Development of a Low-Cost Semantic Monitoring System for Vineyards Using Autonomous Robots

Agriculture ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 182
Author(s):  
Abhijeet Ravankar ◽  
Ankit A. Ravankar ◽  
Michiko Watanabe ◽  
Yohei Hoshino ◽  
Arpit Rawankar
Keyword(s):  
Monitoring System ◽  
Autonomous Robots ◽  
Low Cost ◽  
Smart Phone ◽  
Image Data ◽  
Optimal Harvest ◽  
System Logs ◽  
Robot Systems ◽  
Increase Productivity ◽  
Labor Consuming

Many tasks involved in viticulture are labor intensive. Farmers frequently monitor the vineyard to check grape conditions, damage due to infections from pests and insects, grape growth, and to estimate optimal harvest time. Such monitoring is often done manually by the farmers. Manual monitoring of large vineyards is time and labor consuming process. To this end, robots have a big potential to increase productivity in farms by automating various tasks. We propose a low-cost semantic monitoring system for vineyards using autonomous robots. The system uses inexpensive cameras, processing boards, and sensors to remotely provide timely information to the farmers on their computer and smart phone. Unlike traditional systems, the proposed system logs data ‘semantically’, which enables pin-pointed monitoring of vineyards. In other words, the farmers can monitor only specific areas of the vineyard as desired. The proposed algorithm is robust for occlusions, and intelligently logs image data based on the movement of the robot. The proposed system was tested in actual vineyards with real robots. Due to its compactness and portability, the proposed system can be used as an extension in conjunction with already existing autonomous robot systems used in vineyards. The results show that pin-pointed remote monitoring of desired areas of the vineyard is a very useful and inexpensive tool for the farmers to save a lot of time and labor.

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