scholarly journals A prediction model of the surface topography due to the unbalance of the spindle system in ultra-precision fly-cutting machining

2018 ◽  
Vol 10 (1) ◽  
pp. 168781401774714
Author(s):  
Dongju Chen ◽  
Xianxian Cui ◽  
Ri Pan ◽  
Jinwei Fan ◽  
Chenhui An
Keyword(s):  
Prediction Model ◽  
Surface Topography ◽  
Rotation Speed ◽  
Surface Generation ◽  
Machining Accuracy ◽  
Machined Surface ◽  
Spindle System ◽  
Fly Cutting ◽  
Ultra Precision ◽  
Aerostatic Spindle

In ultra-precision fly-cutting machining, the aerostatic spindle is the key component, which has significant influence on the machined surface quality. The unbalanced spindle directly affects the machining accuracy. In this article, a prediction model of machining surface topography is proposed which involves the effect of the gas film performance of spindle in microscale. With the Weierstrass function, unstable transient response of the aerostatic spindle system is derived by the motion model of the spindle, which response signal represents the surface profile in the ultra-precision machining. Meanwhile, the experiment is performed with different rotation speed of the spindle. And the effect of the unbalanced aerostatic spindle on the surface generation is discussed in time and frequency domain. The conclusion shows that the similar cyclical surface ripple of the workpiece is independent of the spindle speed, and the rotation speed of the spindle and unbalanced spindle directly affects the machining surface topography. This study is quite meaningful for deeply understanding the influence rule of spindle unbalanced error from the viewpoint of machined surface and vibration frequency.

Influencing Factors of Surface Generation in Ultra-Precision Fly Cutting

2016 ◽  
Vol 1136 ◽  
pp. 221-226
Author(s):  
Lan Zhan ◽  
Fei Hu Zhang ◽  
Chen Hui An ◽  
Zhi Peng Li
Keyword(s):  
Surface Topography ◽  
Influencing Factors ◽  
Surface Profile ◽  
Surface Generation ◽  
Cutting Machine ◽  
Fly Cutting ◽  
3D Surface ◽  
Ultra Precision ◽  
Topography Model ◽  
Great Focus

Ultra-precision fly cutting machines have long been the hardest one to compliant and induce great focus of researchers. In this paper, a surface topography model is proposed to predict the surface generation in an ultra-precision fly cutting machine. The building of surface topography model is based on the trace of the tool tip. With the 3D surface profile simulations of workpieces, several influencing factors of surface topography, especially the factors related to micro waviness error, are studied.

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.

scholarly journals Theoretical prediction and experimental verification of the unbalanced magnetic force in air bearing motor spindles

2019 ◽  
Vol 233 (12) ◽  
pp. 2330-2344 ◽  
Author(s):  
Quanhui Wu ◽  
Yazhou Sun ◽  
Wanqun Chen ◽  
Qing Wang ◽  
Guoda Chen
Keyword(s):  
Surface Topography ◽  
Surface Quality ◽  
Magnetic Force ◽  
Research Work ◽  
Diamond Turning ◽  
Surface Generation ◽  
Air Bearing ◽  
Machined Surface ◽  
Spindle Shaft ◽  
Ultra Precision

Dynamic vibrations of air bearing motor spindles have significant influence on the surface quality in ultra-precision machining. In this article, the influence of the vibration caused by the unbalanced magnetic force on the diamond turning is investigated on the basis of the theoretical and experimental method. A permanent magnet motor model (10 poles and 12 slots) is built and then simulated to gain a periodic unbalanced magnetic force. The effects of unbalanced magnetic force on the inclination of the spindle shaft is analyzed, which would affect the surface quality of the workpiece, and the surface topography of the workpiece is predicted during an unbalanced magnetic force acting on air bearing motor spindle. The theoretical analysis and experimental turning results validate that the angle between the direction of unbalanced magnetic force and the feed direction has a certain relationship with the profile of the machined surface. Also, under different turning speeds and directions, the surface topography of the machined workpiece shows a 10-cycle-per-revolution pattern, which has good agreement with the simulations of periodic unbalanced magnetic force. This research work provides a theoretical foundation for the fault diagnosis of air bearing motor spindle caused by motor rotor eccentricity and its effect on surface generation in turning.

scholarly journals Dynamic Generation of Machined Surfaces, Part 2: Construction of Surface Topography

1991 ◽  
Vol 113 (2) ◽  
pp. 145-153 ◽  
Author(s):  
G. M. Zhang ◽  
S. G. Kapoor
Keyword(s):  
Surface Topography ◽  
Random Excitation ◽  
Surface Generation ◽  
Distribution Model ◽  
Excitation System ◽  
Machined Surface ◽  
Spiral Trajectory ◽  
Vibratory Motion ◽  
Texture Generation ◽  
Simulation Results

In Part 1 of these two-part papers, a normal distribution model has been formulated to describe the random excitation system present during machining. Part 2 presents a methodology to dynamically generate the surface topography under the random excitation environment through computer simulation. The proposed methodology uses the tool vibratory motion along with the tool geometrical motion to construct the topography of a machined surface. Both experimental and simulation results confirm that when a small feed is used, the influence of the spiral trajectory of tool geometrical motion on the surface generation decays dramatically and the random excitation system, on the opposite, is strengthened playing a significant role in surface texture generation.

Diamond Fly Cutting Applied to Improve Curved Surface Machining by In-Process Measurement and Control on an Ordinary Milling Machine

2020 ◽  
Author(s):  
Tatsuki Otsubo ◽  
Takanori Yazawa ◽  
Jinhui Wang ◽  
Tomonori Kato
Keyword(s):  
Diamond Turning ◽  
Milling Machine ◽  
Machined Surface ◽  
Form Accuracy ◽  
Surface Machining ◽  
Process Measurement ◽  
Fly Cutting ◽  
Ultra Precision ◽  
And Control ◽  
Measurement And Control

Abstract To improve the accuracy of the machined surface produced by an ordinary milling machine, a system called workpiece-referred form accuracy control (WORFAC) was developed and confirmed in diamond turning. However, non-rotational symmetric surface structures, such as V-grooves, pyramid structures, F-theta lenses, and other free form surface cannot be machined by diamond turning. We proposed to improve the form accuracy of a machined surface produced by an ordinary milling machine by diamond fly cutting using controlled cutting with reference surface (CCRS), an in-process measurement and control method. Fly cutting is usually used to manufacture ultra-precision microstructures with nanometric surface roughness and submicrometric form accuracy, without the need for subsequent polishing. Nevertheless, a high level of accuracy has only recently been achieved on ultra-precision milling machines. In this study, we verified the effectiveness of fly cutting with CCRS on an ordinary milling machine. CCRS improves machined surface accuracy by controlling the relative displacement between the tool and workpiece. Diamond fly cutting using CCRS was demonstrated to reduce the table motion error on an ordinary milling machine. The experiments of curved surface machining by uncontrolled machining and control machining were conducted, and the effectiveness of improving the circular are machining accuracy of the general-purpose milling machine was confirmed.

Gyroscopic Torque Analysis and Dynamic Balance Test of the Vertical Aerostatic Spindle

2011 ◽  
Vol 697-698 ◽  
pp. 686-691
Author(s):  
Fei Hu Zhang ◽  
Peng Qiang Fu ◽  
C.H. An ◽  
Jiu Wei Sun ◽  
Sheng Fei Wang
Keyword(s):  
Dynamic Characteristics ◽  
Dynamic Pressure ◽  
Dynamic Balance ◽  
Reaction Force ◽  
Rigid Body Dynamics ◽  
Machining Accuracy ◽  
Balance Test ◽  
Close Relationship ◽  
Ultra Precision ◽  
Aerostatic Spindle

Ultra-precision flying cutting machining with a vertical milling style is an important means of ultra-precision machining. It has a close relationship between the machining accuracy and the dynamic characteristics of the aerostatic spindle. The film force acting on the spindle rotor is related to the manufacture, installation and static unbalance or dynamic imbalance or other factors. Therefore, it is necessary to analyze the dynamic pressure force caused by these factors in order to study on the rotor posture and quantitative movement of the spindle. This article derived the solution formula for the dynamic pressure reaction force of the ultra-precision machine tool spindle with vertical static film based on the basic theory of the rigid body dynamics. The gyroscopic torque of the spindle has been analyzed under different conditions with the spindle dynamic balancing tests, which provide a reference to the further analysis of the spindle dynamic characteristics.

Correlating Surface Functionality with Machining Conditions in Precision Machining Processes

2004 ◽  
Vol 471-472 ◽  
pp. 112-116
Author(s):  
X.C. Luo ◽  
K. Cheng ◽  
R. Ward
Keyword(s):  
Surface Topography ◽  
Tool Path ◽  
Surface Generation ◽  
Force Model ◽  
Generation Model ◽  
Machining Processes ◽  
Machined Surface ◽  
Surface Functionality ◽  
Precision Turning ◽  
Machining Conditions

This paper attempts to correlate surface functionality generation with machining conditions by computer simulation and machining trials. The linear and nonlinear machining conditions, such as feed rate, built-up-edge, shear- localized chip formation, regenerative chatter are modelled in the light of their physical features. They are the inputs to the integrated surface topography generation model. The dynamic tool path is calculated through the dynamic cutting force model and surface response model. The surface is generated by transforming the tool profile onto the workpiece surface along the dynamic tool path. All of these models are integrated in a user-friendly Matlab Simulink environment. On the basis of the Simulink model, the dynamic simulation is performed to predict the 3D machined surface topography and its functionality. The simulation results have been validated by precision turning trials. The spectrum analysis of the machining dynamics and surface topography shows that surface generation is highly affected by the nonlinear factors in precision turning process. A case study shows the feasibility of generating some functional surface for some product/component through controlling machining variables.

scholarly journals Prediction of machining accuracy based on geometric error estimation of tool rotation profile in five-axis multi-layer flank milling process

2020 ◽  
Vol 234 (11) ◽  
pp. 2160-2177
Author(s):  
Hangzhuo Yu ◽  
Lei Jiang ◽  
Jindong Wang ◽  
Shengfeng Qin ◽  
Guofu Ding
Keyword(s):  
Prediction Model ◽  
Great Influence ◽  
Milling Process ◽  
Geometric Error ◽  
Flank Milling ◽  
Machining Accuracy ◽  
Machined Surface ◽  
Contact Points ◽  
Five Axis ◽  
Tool Rotation

In five-axis multi-layer flank milling process, the geometric error of tool rotation profile caused by radial dimension error and setup error has great influence on the machining accuracy. In this work, a new comprehensive error prediction model considering the inter-layer interference caused by tool rotation profile error is established, which incorporates a pre-existing prediction model dealing with a variety of errors such as geometric errors of machine tool, workpiece locating errors, and spindle thermal deflection errors. First, a series of tool contact points on the tool swept surface in each single layer without overlapping with others are calculated. Second, the position of the tool contact points on the overlapped layers is updated based on the detection and calculation of inter-layer interferences. Third, all evaluated tool contact points on the final machined surface are available for completing the accuracy prediction of the machined surface. A machining experiment has been carried out to validate this prediction model and the results show the model is effective.

scholarly journals Characterization of the Friction Coefficient of Aluminum Alloy 6061 in Ultra-Precision Machining

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 336 ◽  
Author(s):  
Hailong Wang ◽  
Tao Zhang ◽  
Sujuan Wang ◽  
Suet To
Keyword(s):  
Aluminum Alloy ◽  
Friction Coefficient ◽  
Surface Generation ◽  
Precision Machining ◽  
Diamond Cutting ◽  
Machined Surface ◽  
Friction Coefficients ◽  
Aluminum Alloy 6061 ◽  
Ultra Precision ◽  
Alloy 6061

Aluminum alloy 6061(Al6061), an Al-Mg-Si alloy, is a precipitation-hardened alloy. The generation of precipitate affects its mechanical properties, and induces a worse surface finish during diamond cutting. The friction coefficients of the tool-chip and tool-workpiece interfaces influence temperature rise, and are therefore important predictors of tool wear and surface integrity during the diamond cutting of Al6061. This study investigated the relationship between precipitate generation and the friction coefficients of Al6061. Groups of experiments were conducted to study the influence of temperature and heating time on the number of precipitates and the friction coefficients. The results show that the generation of AlFeSi particles induces cracks, scratch marks and pits on diamond-machined Al6061 and affects the cutting forces. Moreover, the variation trend of the friction coefficient of Al6061 under different heating conditions agrees well with that of the number of AlFeSi particles. This implies that, during ultra-precision machining of precipitation-hardened alloys, cutting-induced heat causes precipitates to form on the chips and machined surface, changing their material properties. This affects the tool-workpiece and tool–chip contact conditions and the mechanisms of chip formation and surface generation in ultra-precision machining.

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