Influence assessment of metal-cutting equipment geometrical accuracy on OMV-technologies accuracy

2016 ◽  
Author(s):  
A. G. Koltsov ◽  
D. A. Blokhin ◽  
E. V. Krivonos ◽  
A. N. Narezhnev
Keyword(s):  
Metal Cutting ◽  
Geometrical Accuracy ◽  
Cutting Equipment

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

The Influence of Toolpath Strategy on Geometric Accuracy in Incremental Forming

2013 ◽  
Vol 554-557 ◽  
pp. 1351-1361 ◽  
Author(s):  
Elif Malyer
Keyword(s):  
Surface Roughness ◽  
Sheet Metal ◽  
Metal Cutting ◽  
The Other ◽  
Geometric Accuracy ◽  
Geometrical Accuracy ◽  
Other Hand ◽  
Drawing Angle ◽  
Tool Diameter ◽  
Cam Software

Incremental sheet metal forming is a new process to manufacture sheet metal parts and it is becoming a remarkable technology for fast prototyping and small lot production because of the advantages of this technology such as process flexibility, product independent tooling and higher formability. On the other hand, limited maximum drawing angle, relatively coarse surface roughness, low geometrical accuracy and long forming time are common disadvantages of the process. Furthermore, it is affected by process parameters which are tool diameter, forming velocity, spindle speed, forming geometry and depth, etc. Toolpath strategy which is used to form sheet metal by CNC machine has a key role among these parameters. The present study has been undertaken in order to investigate the suitable toolpath strategy which is developed for metal cutting by commercial CAD/CAM software to increase geometrical accuracy and decrease thinning and forming time. For the intended purpose, seven different toolpath strategies which are rough and finish strategies were used to form a truncated frustum by using one millimeter thick S235JR steel alloy. The effect of each strategy on the surface roughness, geometrical accuracy and thinning distribution of formed product was studied by measuring thickness, drawing angle and depth of formed parts. Therefore, formed parts scanned by 3D laser scanner and STL files of parts were generated then STL files were converted into CAD file. CAD data of parts was used for measurements. The measurements showed that not only forming movements but also transition movements along the tool path affected the geometric accuracy and thinning distribution, surface roughness and forming time of formed parts. On the other hand it was observed that rough strategies were given good results as finish strategies and tool paths generated by CAM software need to be editing for better geometric accuracy, thinning, forming time and surface quality.

scholarly journals Technological prerequisites for the energy efficiency increase of the engine cylinder bore processing

2021 ◽  
Vol 279 ◽  
pp. 01001
Author(s):  
Lydmila Safarova ◽  
Andrey Malikov ◽  
Alexandr Yamnikov ◽  
Olga Yamnikova
Keyword(s):  
Metal Cutting ◽  
Engine Cylinder ◽  
Efficiency Increase ◽  
Cutting Equipment ◽  
Shaft Furnaces ◽  
Reduce Energy Consumption ◽  
Parameters Of Accuracy ◽  
Machining Operations ◽  
Cylinder Bore

An example of the rationalization of the current technology for manufacturing a cylinder of a small-sized diesel engine at PA “TULAMASHZAVOD” from a cast iron is given. It is shown that lowpower obsolete equipment leads to an increase in the number of technological operations and equipment used. However, even if all the generally accepted technological recommendations are followed, only 80% of the parts meet the requirements for the required parameters of accuracy and quality of the cylinder bore surface. Studies have found that the main reasons for insufficient quality are the presence of residual stresses in the casting, which cannot be removed during artificial aging, as well as insufficient accuracy and rigidity of metal cutting equipment at turning and boring operations. The use of more powerful and accurate modern equipment is theoretically and experimentally justified, which, due to increased refinement, allows reducing the number of machining operations. Replacement of artificial thermal aging by natural, combined with the replacement of shaft furnaces for heat treatment of workpieces with chamber furnaces of lower power and higher capacity, reduce energy consumption for the manufacturing by almost 4 times.

scholarly journals MATING SURFACES MACHINING IN CROSSED CHANNELS

2020 ◽  
Vol 2020 (3) ◽  
pp. 4-10
Author(s):  
Oleg Kirillov ◽  
Vladislav Smolencev ◽  
Evgeniy Kotukov
Keyword(s):  
Electric Field ◽  
High Speed ◽  
Metal Cutting ◽  
Working Environment ◽  
Mathematical Statistics ◽  
Work Piece ◽  
High Speed Machining ◽  
Mathematical Apparatus ◽  
Cutting Equipment ◽  
Selection Of

The purpose of the work is the application of a non-profiled electrode-brush for mating surfaces machining including that in crossed channels. To achieve the goal set there were problems under solution: the development of essential equipment, electrode-tools, the selection of working environment, the optimization of combined machining modes. To solve the problems set there are used basis regulations of the theory: electric and combined methods of machining, the mathematical apparatus of probability theories and mathematical statistics. In the paper the developed and manufactured plants and electrode-tools are shown. The recommended machining conditions, working environment are shown. The equipment is presented with a small-size plant for high-speed machining with an electrode-brush and a portable plant fixed on a drill rod that with the use of operating fluid recommended allows reducing considerably the terms and cost of metal cutting equipment updating for machining with electric field imposition. In the paper there are considered standard parts: nozzles, ejector bodies, parts of piping hydro-systems. The results of machining parts with crossed channels are shown. The application of processing by an electrode-brush with high circumferential velocities with regard to the work-piece from 35 m/sec and higher allows manufacturing products with the set values. The application of an electrode-brush is efficient for mating surfaces combined machining.

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 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.

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