Nonlinear Analysis of Axial Vibration of Five-Axis Machine Tool Worktable With Double Turntable

2021 ◽  
Author(s):  
Shi Wu ◽  
Taorui Liu ◽  
Xianli Liu ◽  
Zhengdong Fan ◽  
Yipeng Li
Keyword(s):  
Machine Tool ◽  
External Load ◽  
Vibration Amplitude ◽  
Processing System ◽  
Axial Direction ◽  
Machining Process ◽  
Machining Accuracy ◽  
Axial Vibration ◽  
Applied Torque ◽  
Five Axis

Abstract Studies show that the applied torque and load on the worktable of a dual-turntable five-axis machine tool continuously changes during the machining process. These variations generate vibration in the worktable along the axial direction, thereby reducing the machining accuracy. In order to improve the machining accuracy of the machine tool and the dynamic characteristics of the worktable, this paper first established the nonlinear dynamic equation of the axial vibration of the machine tool table when the worktable is subjected to torque, swing moment and load according to the elasticity of the plate and shell; then according to Galerkin The truncation method solves the dynamic displacement in the axial direction of the worktable, as well as the bifurcation diagram, displacement waveform diagram, phase plane trajectory and Poincaré cross-section diagram of the processing system; Finally, the influence of different parameters, including torque, swing moment, and load on axial vibration of the worktable was analyzed during the tool operation. The obtained results reveal that as the external load changes, the corresponding axial vibration of the worktable is mainly in the state of large periodic motion, where the maximum vibration amplitude reaches 0.09mm, and the external load has the greatest influence on the axial vibration of the worktable. Moreover, the axial vibration of the worktable is affected by the swing moment. More specifically, in the chaotic state of a small period and small area, the maximum vibration amplitude reaches 0.03mm, and the swing moment has a negligible effect on the axial vibration of the worktable. The influence of torque and load on the vibration characteristics of the five-axis machine tool table during machining was studied through experiments. The obtained results demonstrate that non-linear analysis of the table axial vibration of the five-axis machine tool with dual turntables is an effective way to control the stability of the worktable during the processing of the workpiece.

Sensitivity Analysis of Geometric Errors for Five-Axis CNC Machine Tool Based on Multi-Body System Theory

2012 ◽  
Vol 271-272 ◽  
pp. 493-497
Author(s):  
Wei Qing Wang ◽  
Huan Qin Wu
Keyword(s):  
System Theory ◽  
Sensitivity Analysis ◽  
Machine Tool ◽  
Geometric Error ◽  
Machining Accuracy ◽  
Geometric Errors ◽  
Body System ◽  
Cnc Machine ◽  
Multi Body ◽  
Five Axis

Abstract: In order to determine that the effect of geometric error to the machining accuracy is an important premise for the error compensation, a sensitivity analysis method of geometric error is presented based on multi-body system theory in this paper. An accuracy model of five-axis machine tool is established based on multi-body system theory, and with 37 geometric errors obtained through experimental verification, key error sources affecting the machining accuracy are finally identified by sensitivity analysis. The analysis result shows that the presented method can identify the important geometric errors having large influence on volumetric error of machine tool and is of help to improve the accuracy of machine tool economically.

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.

Geometric accuracy allocation for multi-axis CNC machine tools based on sensitivity analysis and reliability theory

2014 ◽  
Vol 229 (6) ◽  
pp. 1134-1149 ◽  
Author(s):  
Qiang Cheng ◽  
Ziling Zhang ◽  
Guojun Zhang ◽  
Peihua Gu ◽  
Ligang Cai
Keyword(s):  
Sensitivity Analysis ◽  
Machine Tool ◽  
Operating Conditions ◽  
Numerical Control ◽  
Cnc Machine Tools ◽  
Machining Accuracy ◽  
Geometric Errors ◽  
Volumetric Error ◽  
The Cost ◽  
Five Axis

Machining accuracy of a machine tool is influenced by geometric errors produced by each part and component. Different errors have varying influence on the machining accuracy of a tool. The aim of this study is to optimize errors to get a desired performance for a numerical control machine tool. Applying multi-body system theory, a volumetric error model was constructed to track and compensate effects of errors during operation of the machine, and to relate the functional specifications on volumetric accuracy to the permissible errors on the joints and links of the machine. Error sensitivity analysis was used to identify the influence of different errors (especially the errors which have large influences) on volumetric error. Based on First Order and Second Moment theory, an error allocation approach was developed to optimize allocation of manufacturing and assembly tolerances along with specifying the operating conditions to determine the optimal level of these errors so that the cost of controlling them and the cost of failure to meet the specifications is minimized. The approach developed was implemented in software and an example of the geometric errors budgeting for a five-axis machine was discussed. It is identified that the different optimal standard deviations reflect the cost-weighted influences of the respective parameters in the equations of the functional requirements. This study suggests that it is possible to determine the coupling relationships between these errors and optimize the allowable error budgeting between these sources.

scholarly journals Tool-Path Planning Method For Kinematics Optimization of Blade Machining On Five-Axis Machine Tool

2022 ◽  
Author(s):  
Zhongyang Lu ◽  
Xu Yang ◽  
Ji Zhao
Keyword(s):  
Path Planning ◽  
Machine Tool ◽  
Tool Path ◽  
Machining Process ◽  
Free Form ◽  
Traditional Methods ◽  
Machining Quality ◽  
Blade Machining ◽  
Kinematic Performance ◽  
Five Axis

Abstract Planning tool-paths on free-form surfaces is a widely discussed issue. However, traditional methods of generating paths capable of meeting all the requirements of blade machining remain challenging. In this study, a new iso-parametric path-planning strategy based on a novel parameterization method combined with the conformal transformation theory was proposed. The proposed method could adapt to the curvature characteristics of the blade surface, improving the kinematic performance of the machining process, reducing multi-axis coordinated motion control complexity, and improving machining quality. The proposed method was then compared with three traditional methods. The influence of the tool-path on the kinematic performance of the machine tool was quantitatively examined based on the kinematics models of two different machine tools. A large cutting depth milling experiment was conducted to verify that kinematics optimization could improve machining quality. The proposed method provides a more reasonable path-planning approach for blade machining on a five-axis machine tool, which is of great significance in reducing the cost of blade machining and the risks of blade failure. Moreover, it is of great significance for the large-scale automated production of blades.

Mini Special Issue on Machining Control and Process Monitoring

2014 ◽  
Vol 8 (6) ◽  
pp. 791-791
Author(s):  
Tojiro Aoyama
Keyword(s):  
Machine Tool ◽  
Process Monitoring ◽  
Machine Tools ◽  
Cutting Tools ◽  
Machining Process ◽  
Machining Accuracy ◽  
Special Issue ◽  
Practical Proposal ◽  
Machining Control ◽  
Novel Approaches

Control and process monitoring are key technologies supporting high machining accuracy and efficiency. This special issue features six papers taking novel approaches to controlling machine and cutting tools and monitoring the machining process. The motion control of machine tools and cutting tools are introduced. A new challenge for monitoring the machining process by referring to NC control servo signals implements a practical proposal. The precise identification of friction at driving elements of machine tool components is an important factor in improving machine tool control motion accuracy. I would like to express my sincere appreciation to the authors and reviewers whose invaluable efforts have helped make the publication of this manuscript possible.

Development of Post-Processing System for Three Types of Five-Axis Machine Tools Based on Solid Model

2017 ◽  
Author(s):  
J. Li ◽  
Yangpeng Song ◽  
Ye Liu
Keyword(s):  
User Interface ◽  
Data Processing ◽  
Machine Tool ◽  
Processing System ◽  
Data Access ◽  
Interface Layer ◽  
Solid Model ◽  
Post Processing ◽  
Nc Data ◽  
Five Axis

Although machine control data can be obtained by means of converting cutter location (CL) data comprised of the tool tip coordinate and the tool axis orientation vector in the workpiece coordinate frame with postprocessor, it’s uncertain whether they can be used for 5-axis machining. Owing to the fact that most postprocessors focus on the method to derive solutions for the equations of NC data by the form-shaping function matrix and the inverse kinematics model without taking the manufacturing scene into consideration, this study has presented a new post-processing system to generate and optimize NC data more effectively by correcting and selecting optimum solution intelligently for machining based on the solid model of machine tool in simulation environment. In general, the post-processing system consists of user interface layer, data access layer and data processing layer to give expression to the characteristics of universality, practicality and adaptability. User interface layer is mainly about loading the machine model and setting the relevant parameters. Data access layer includes model library of generalized five-axis machine tool configurations, rules library of cutter location data and NC data. Data processing layer is the major research in the paper, which illustrates how to correct the inverse solutions set and select the optimization solution for actual machining. The visual interface for post-processing system written by C++ was successfully applied in the experiment on a five-axis machine tool with a C-axis behind a B-axis rotary table, which demonstrated the effectiveness of the proposed post-processing methodology in the field of manufacturing.

Measurement and analysis for frequency domain error of ultra-precision spindle in a flycutting machine tool

2016 ◽  
Vol 232 (9) ◽  
pp. 1501-1507 ◽  
Author(s):  
Guoda Chen ◽  
Yazhou Sun ◽  
Chenhui An ◽  
Feihu Zhang ◽  
Zhiji Sun ◽  
...  
Keyword(s):  
Machine Tool ◽  
Frequency Domain ◽  
Frequency Domain Analysis ◽  
Frequency Characteristics ◽  
Machining Process ◽  
Machining Accuracy ◽  
Machined Surface ◽  
Ultra Precision ◽  
Machining Process Planning ◽  
Aerostatic Spindle

The ultra-precision spindle is the key component of ultra-precision machine tool, which largely influences the machining accuracy. Its frequency characteristics mainly affect the frequency domain error of the machined surface. In this article, the error measurement setup for the ultra-precision aerostatic spindle in a flycutting machine tool is established. The dynamic and multi-direction errors of the spindle are real-time measured under different rotation speeds. Then, frequency domain analysis is carried out to obtain its regularity characteristics based on the measurement result. Through the analysis, the main synchronous and asynchronous errors with relatively large amplitude of the spindle errors are found, and the amplitude change law of these main spindle errors is obtained. Besides, the cause of the main synchronous and asynchronous errors is also analyzed and indicated. This study deepens the understanding of ultra-precision spindle dynamic characteristics and plays the important role in the spindle frequency domain errors’ control, machining process planning, frequency characteristics analysis and oriented control of the machined surface errors.

Calibration and Optimization for Spindle-Tilting Type Five-Axis Machine Tools with Inclinable Head AB Based on Compensation of Rotation Axis Direction Error

2013 ◽  
Vol 288 ◽  
pp. 19-24
Author(s):  
Feng Liu ◽  
Hu Lin ◽  
Liao Mo Zheng ◽  
Feng Wang ◽  
Lei Yang
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Rotation Axis ◽  
Position Vector ◽  
Machining Accuracy ◽  
Direction Error ◽  
Rotation Center ◽  
Rtcp Function ◽  
On Line ◽  
Five Axis

To solve the five-axis machining accuracy problems that caused by assembly precision and direction error of rotary axes of inclinable head in high precision five axis machine tool. By selecting the five axis machine tool with inclinable head AB, GMC1230u, as the research object and analyzing the causes of the inclinable head error, the kinematics relationship of the rotation center position error and axis tilt error is established. By that, the direction vectors of each rotation axis and the position vector of rotation center are calculated based on the regression analysis of on-line measurement of the tool center point position and the calibration of five-axis RTCP function parameters is also accomplished. Finally, the compensation for inclinable head error in five-axis machine tools is fulfilled efficiently and remarkable improvement of RTCP machining accuracy is achieved.

Optimizing of Integral Impeller NC Program Based on the Material Removal Rate

2014 ◽  
Vol 1030-1032 ◽  
pp. 1305-1308
Author(s):  
Shi Chao Li ◽  
Song Lin Wu ◽  
Yan Kun Liang
Keyword(s):  
Material Removal Rate ◽  
Machine Tools ◽  
Material Removal ◽  
Removal Rate ◽  
Cnc Machining ◽  
Machining Process ◽  
Machining Accuracy ◽  
Nc Machine ◽  
Nc Machine Tools ◽  
Five Axis

It is a general processing technology that multi-axis NC machine tools is used for machining impeller at present. In order to improve the machining accuracy of the five-axis NC machine tools, the paper analyzes the computing interpolation error of the Multi-axis CNC system in detail. Some of the measures of tools selection have been proposed in purpose of diminishing the accumulative error of the system. The paper also establishes the optimized objective function to optimize the process parameters of the CNC machining based on the material removal rate. All these measures will improve the machining efficiency significantly and increase the stationary of the machining process.

Development and Simulation of WEDM Five-Axis Linkage Machining

2013 ◽  
Vol 753-755 ◽  
pp. 924-927
Author(s):  
Xin Rong Wang ◽  
Ya Chao Cui ◽  
Yong Cheng Jiang
Keyword(s):  
Machine Tool ◽  
Complex Space ◽  
Machining Process ◽  
Curved Surface ◽  
Rotary Table ◽  
Key Technology ◽  
Application Range ◽  
Surface Work ◽  
Machining System ◽  
Five Axis

In order to solve the problem of machining work-pieces with complex space curved surface, a machining system was developed, and the rotary table with two sways is the most important part. The motion rules of machining work-pieces with complex space curved surface were analyzed, and the computer simulation of WEDM five-axis linkage system was put forward. Through running the simulation programs, the whole machining process of WEDM five-axis linkage system can be directly observed, and the satisfactory simulation results can be obtained. The NC machining system with five-axis linkage by WEDM was developed, and the complex curved surface work-pieces can be machined by combining the rotary table with two sways with the WEDM-HS machine tool. The key technology problem of machining work-pieces with complex space curved surface has been fundamentally solved, and the application range of WEDM-HS machine tool is widened, which suit the specific conditions in China.

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