Full-factor matrix model of accuracy of dimensions performed on multi-purpose CNC machines

2021 ◽  
Vol 23 (4) ◽  
pp. 6-20
Author(s):  
Nizami Yusubov ◽  
◽  
Heyran Abbasova ◽  
Keyword(s):  
Matrix Models ◽  
Cutting Conditions ◽  
Machining Process ◽  
Technological System ◽  
Design System ◽  
Machining Accuracy ◽  
Factor Matrix ◽  
Cnc Machines ◽  
Plane Parallel ◽  
Base Points

Introduction. One of the main reasons that modern multi-purpose CNC machines do not use the capabilities of multi-tool processing is the lack of recommendations for design in this direction and, accordingly, for adjustment schemes. The study of the possibilities of multi-tool processing on multi-purpose machines is the subject of the work. The purpose of research: The problem of developing full-factor matrix models of dimensional accuracy and its sensitivity to the machining process is considered to increase the machining efficiency while ensuring machining accuracy using the technological capabilities of multi-tool machining on modern multi-purpose CNC machines. For this purpose, full-factor matrix models of the size scattering fields performed on multi-tool double-carriage adjustments have been developed, taking into account the cases of processing parts with dimensions that differ sharply in different directions, which are often encountered in practice, and in this case, the significant influence of the turns of the workpiece on the processing error, especially in directions with sharply different overall dimensions. Results of research: The developed accuracy models make it possible to calculate not only plane-parallel displacements of the technological system for double-carriage adjustments, but also angular displacements around base points, take into account the combined effect of many factors – a complex characteristic of the subsystems of the technological system (plane-parallel matrix of compliance and angular matrix of compliance), the geometry of the cutting tool , the amount of bluntness of the tool, cutting conditions, etc. As a result, based on the developed accuracy models, it is possible to obtain several ways to control multi-tool machining, including improving the structure of multi-tool adjustments, calculating the limiting values of cutting conditions. Based on the developed full-factor matrix models, it became possible to develop recommendations for the design of adjustments and the creation of an automated design system for multi-tool machining for a group of modern multi-purpose CNC lathes. Scope of the results: The results obtained can be used to create mathematical support for the design of operations in CAD-systems provided for multi-tool multi-carriage machining performed on multi-purpose machines. Conclusions: The developed models and methodology for simulating the machining accuracy make it possible to increase the accuracy and efficiency of simultaneous machining, to predict the machining accuracy within the specified conditions.

Models for Machining Accuracy in Multi-Tool Adjustment

2020 ◽  
Vol 17 (3) ◽  
pp. 8067-8085
Author(s):  
N.D. Yusubov ◽  
H.M. Abbasova
Keyword(s):  
Degrees Of Freedom ◽  
Cutting Conditions ◽  
Technological System ◽  
Machining Accuracy ◽  
Six Degrees Of Freedom ◽  
Cnc Lathe ◽  
Deformation Properties ◽  
Angular Displacements ◽  
Influence Degree ◽  
Full Factorial

The article discusses the technology capabilities of multi-purpose CNC machines, and possible options for implementing parallel multi-tool processing. It was revealed that the technological capabilities of these machines are used at best by 50% in factories. This is due to the lack of recommendations for the design and use of such adjustments for these machines. To this end, generalised lattice matrix models of the accuracy of multi-tool machining have been developed in order to fulfill the requirements of algorithmic uniformity models and their structural transparency. The use of lattice matrices greatly simplifies the error in model of multi-tool machining and makes it extremely visual. Also, full-factorial distortion models and scattering fields of the dimensions of multi-tool machining performed on modern multi-purpose CNC lathe machines have been developed to take into account the angular displacements of the workpiece when machining parts with prevailing overall dimensions. They take into account the flexibility of the technological system for all six degrees of freedom to identify the influence degree of complex of technological factors on the machining accuracy (structure of multi-tool adjustment, deformation properties of subsystems of a technological system, cutting conditions). A methodology has been developed for determining the complex characteristics of compliance of a technological system. On the basis of the developed accuracy models in spatial adjustments, it is possible to develop recommendations for the design of adjustments for modern multi-purpose machines in CNC turning group (creation of CAD of multi-tool machining). Thus, it is possible to achieve a number of ways to control multi-tool machining, including improving the structure of multi-tool adjustment, calculating the limiting cutting conditions.

Effect of Cutting Parameters on Surface Roughness in Turning of Bone

2013 ◽  
Vol 845 ◽  
pp. 708-712 ◽  
Author(s):  
P.Y.M. Wibowo Ndaruhadi ◽  
S. Sharif ◽  
M.Y. Noordin ◽  
Denni Kurniawan
Keyword(s):  
Surface Roughness ◽  
Bone Tissue ◽  
Influencing Factor ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Cutting Conditions ◽  
Machining Process ◽  
Turning Operation ◽  
Cutting Direction

Surface roughness indicates the damage of the bone tissue due to bone machining process. Aiming at inducing the least damage, this study evaluates the effect of some cutting conditions to the surface roughness of machined bone. In the turning operation performed, the variables are cutting speed (26 and 45 m/min), feed (0.05 and 0.09 mm/rev), tool type (coated and uncoated), and cutting direction (longitudinal and transversal). It was found that feed did not significantly influence surface roughness. Among the influencing factor, the rank is tool type, cutting speed, and cutting direction.

Dynamic optimization method with applications for machine tools based on approximation model

2017 ◽  
Vol 232 (11) ◽  
pp. 2009-2022 ◽  
Author(s):  
TJ Li ◽  
XH Ding ◽  
K Cheng ◽  
T Wu
Keyword(s):  
Machine Tool ◽  
Performance Optimization ◽  
Machine Tools ◽  
Optimization Design ◽  
Natural Frequencies ◽  
Dynamic Performance ◽  
Machining Process ◽  
Machining Accuracy ◽  
Approximation Model ◽  
Dynamic Behaviors

Natural frequencies and modal shapes of machine tools have position-dependent characteristics owing to their dynamic behaviors changing with the positions of moving parts. It is time-consuming and difficult to evaluate the dynamic behaviors of machine tools and their machining accuracy at different positions. In this paper, a Kriging approximation model coupled with finite element method is proposed to substitute the dynamic equations for obtaining the position-dependent natural frequencies of a machine tool, as well as relative positions between the tool and the workpiece during the machining process. Based on the proposed method, dynamic performance optimization design of the machine tool is conducted under the condition of minimum relative positions. Three case studies are illustrated to demonstrate the implementation of the proposed method.

Direct compensation of the spindle rotation error with an active hydrostatic journal bearing system

2021 ◽  
pp. 095440622110263
Author(s):  
Chunwang Xu ◽  
Shujiang Chen ◽  
Changhou Lu ◽  
Kang Wang ◽  
Jiaheng Sun
Keyword(s):  
Journal Bearing ◽  
Machining Process ◽  
Machining Accuracy ◽  
Accuracy Improvement ◽  
Servo Valve ◽  
Rotation Error ◽  
Spindle Rotation ◽  
Direct Compensation ◽  
Simulation And Experiment ◽  
Bearing System

Spindle rotation accuracy is important in machining process. Indirect compensation of spindle rotation error has been widely adopted in the field of machining accuracy improvement. However, there are some limitations on indirect compensation, and a little research on direct compensation can be found. This article utilizes active lubrication technology to improve the spindle rotation accuracy. Hydrostatic journal bearing with control recesses and servo valve drove by piezoelectric ceramics are adopted to compose the compensation element. The simple control strategy PID is adopted to provide control signal for servo valve. Both simulation and experiment are designed and conducted. The results show that proposed bearing system has the ability to improve the spindle rotation accuracy.

Optimal Clamping Scheme of Thin-Walled Cavity Workpiece

2011 ◽  
Vol 189-193 ◽  
pp. 2116-2120
Author(s):  
Shi Min Geng ◽  
Jun Wang
Keyword(s):  
Finite Element ◽  
Aluminum Alloy ◽  
Machining Process ◽  
Machining Accuracy ◽  
Finite Element Models ◽  
Thin Walled ◽  
Clamping Sequence

The thin-walled cavity workpiece with insufficient rigid property is liable to deform during the machining process and the request of accuracy is very strict. The paper takes typical aeronautic aluminum-alloy for example, fixture is an important consideration in the operation. To reveal the influences of locating points, clamping sequence and loading ways on the distortion of thin-walled cavity part, finite element models were established to simulate the clamping operation. The result shows the preferable scheme is that the distance of the clamping locations are far each other, clamping forces are firstly applied on the surface with high rigid and all clamping forces are applied in many steps. The scheme can effectively control the deformation of clamp ,and furthermore improve the machining accuracy.

scholarly journals Precision Machining of Nimonic C 263 Super AlloyUsing WEDM

Coatings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 590
Author(s):  
Katerina Mouralova ◽  
Libor Benes ◽  
Josef Bednar ◽  
Radim Zahradnicek ◽  
Tomas Prokes ◽  
...  
Keyword(s):  
Electrical Discharge ◽  
Cutting Speed ◽  
Machining Process ◽  
Precision Machining ◽  
Machining Accuracy ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Super Alloy ◽  
Machined Surfaces

Wire electrical discharge machining (WEDM) is an unconventional and very efficient technology for precision machining of the Nimonic C 263 super alloy, which is very widespread, especially in the energy, aerospace and automotive industries. Due to electrical discharge, defects in the form of cracks or burned cavities often occur on the machined surfaces, which negatively affect the correct functionality and service life of the manufactured components. To increase the efficiency of the machining of Nimonic C 263 using WEDM, in this study, extensive design of experiments was carried out, monitoring input factors in the form of machine parameters like Pulse off time, Gap voltage, Discharge current, Pulse on time and Wire feed, the output of which was comprehensive information about the behaviour of such machined surfaces, which allowed the optimization of the entire machining process. Thus, the optimization of the Cutting speed was performed in relation to the quality of the machined surface and the machining accuracy, as well as an analysis of the chemical composition of the machined surfaces and a detailed analysis of the lamella using a transmission electron microscope. A detailed study of the occurrence of surface or subsurface defects was also included. It was found that with the help of complex optimization tools, it is possible to significantly increase the efficiency of the machining of the Nimonic C 263 super alloy and achieve both financial savings in the form of shortened machine time and increasing the quality of machined surfaces.

The Effects of Cutting Conditions on Surface Integrity in Machining Inconel 718 Alloy

2013 ◽  
Vol 554-557 ◽  
pp. 2093-2100 ◽  
Author(s):  
Domenico Umbrello
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Surface Integrity ◽  
Cutting Conditions ◽  
Machining Process ◽  
Process Performance ◽  
Inconel 718 Alloy ◽  
Dry Conditions ◽  
Rapid Tool ◽  
Cutting Speeds

Machining of advancedaerospace materials have grown in the recent years although the hard-to-machinecharacteristics of alloys like titanium or nickel based alloys cause highercutting forces, rapid tool wear, and more heat generation. This paper presentsan experimental evaluation of machining ofInconel718alloy under dry conditions at varying of cutting speeds and feed rates.The influence of the cutting conditions on surface integrity was studied interms of surface roughness, affected layer, grain size variations and phasechanges/modification. Also, the machining process performance was evaluatedthrough the power consumption and tool-wear.

Synchronous Adjustment of Milling Tool Path Based on the Relative Deviation

2011 ◽  
Vol 133 (5) ◽  
Author(s):  
Xiao-Jin Wan ◽  
Cai-Hua Xiong ◽  
Lin Hua
Keyword(s):  
Tool Path ◽  
Cutting Tool ◽  
Cnc Machining ◽  
Numerical Control ◽  
Machining Process ◽  
Machining Accuracy ◽  
Source File ◽  
Modern Computer ◽  
Adjustment Strategy ◽  
Machining System

In machining process, machining accuracy of part mainly depends on the position and orientation of the cutting tool with respect to the workpiece which is influenced by errors of machine tools and cutter-workpiece-fixture system. A systematic modeling method is presented to integrate the two types of error sources into the deviation of the cutting tool relative to the workpiece which determines the accuracy of the machining system. For the purpose of minimizing the machining error, an adjustment strategy of tool path is proposed on the basis of the generation principle of the cutter location source file (CLSF) in modern computer aided manufacturing (CAM) system by means of the prediction deviation, namely, the deviation of the cutting tool relative to the workpiece in computer numerical control (CNC) machining operation. The resulting errors are introduced as adjustment values to adjust the nominal tool path points from cutter location source file from commercial CAM system prior to machining. Finally, this paper demonstrates the effectiveness of the prediction model and the adjustment technique by two study cases.

A Method for Using a Virtual Machining Simulation to Consider Both Equivalent CO2Emissions and Machining Costs in Determining Cutting Conditions

2015 ◽  
Vol 9 (2) ◽  
pp. 115-121 ◽  
Author(s):  
Hirohisa Narita ◽  
Keyword(s):  
Evaluation System ◽  
Cutting Tool ◽  
Cutting Speed ◽  
Cutting Conditions ◽  
Machining Process ◽  
Machining Simulation ◽  
End Mill ◽  
Virtual Machining ◽  
Mill Operation ◽  
Nc Program

An evaluation system for calculating equivalent CO2emissions and machining costs is developed using an activity-based model. The system can evaluate a machining process from an NC program, workpiece information, and cutting tool information, and it can then calculate accurate equivalent CO2emissions and the machining cost. The cutting speed of an end mill operation is evaluated in terms of the equivalent CO2emission and the machining cost. Based on the results, optimal cutting conditions are determined to minimize the equivalent CO2emissions and the machining cost to the extent possible.

An Accuracy-Prediction Model Taking Tool Deformation and Geometric Machine-Tool Error into Consideration

2010 ◽  
Vol 4 (3) ◽  
pp. 235-242 ◽  
Author(s):  
Hirohisa Narita ◽  
◽  
Keiichi Shirase ◽  
Eiji Arai ◽  
Hideo Fujimoto ◽  
...  
Keyword(s):  
Prediction Model ◽  
Machine Tool ◽  
End Milling ◽  
Geometric Error ◽  
Cutting Conditions ◽  
Error Prediction ◽  
Machining Accuracy ◽  
Trial And Error ◽  
Virtual Machining ◽  
Nc Program

Test cutting used to verify cutting conditions and machining accuracy after a numeric control (NC) program is written for end milling the mold and die indispensable to manufacturing is generally effective, because it is based on trial and error. The virtual machining simulator we designed to verify machining accuracy uses an accuracy-prediction model and an error prediction expression for workpieces, integrating machine-tool deformation and geometric error models. We also propose calculation for copying errors to a workpiece.

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