Automatic In-Process Chatter Avoidance in the High-Speed Milling Process

Author(s):  
N. J. M. van Dijk ◽  
E. J. J. Doppenberg ◽  
R. P. H. Faassen ◽  
N. van de Wouw ◽  
J. A. J. Oosterling ◽  
...  

High-speed milling is often used in industry to maximize productivity of the manufacturing of high-technology components, such as aeronautical components, mold, and dies. The occurrence of chatter highly limits the efficiency and accuracy of high-speed milling operations. In this paper, two control strategies are presented that guarantee a chatter-free high-speed milling operation by automatic adaptation of spindle speed and feed. Moreover, the proposed strategies are robust for changing process conditions (e.g., due to heating of the spindle or tool wear). An important part of the control strategy is the detection of chatter. A novel chatter detection algorithm is presented that automatically detects chatter in an online fashion and in a premature phase such that no visible marks on the workpiece are present. Experiments on a state-of-the-art high-speed milling machine underline the effectiveness of the proposed detection and control strategies.

2010 ◽  
Vol 97-101 ◽  
pp. 2123-2127 ◽  
Author(s):  
Yue En Li ◽  
Jun Zhao ◽  
W. Wang ◽  
Q.Y. Cao

The main purpose of this study was to construct a relationship between the cutting parameters and the machined surface on high speed milling operation. An optimization algorithm using an Exponential Equation and BP method (EEBP) is then applied to determine optimal cutting parameters. For using the method, once the material removal volumes for machined parts of the high speed milling operations are given, the surface quality could be predicted. The final result we choose the surface roughness prediction as an example of H13 dies steel HSM in this paper, it presents that the method is efficient and feasible.


2021 ◽  
Vol 5 (2) ◽  
pp. 48
Author(s):  
Jonas Holmberg ◽  
Anders Wretland ◽  
Johan Berglund ◽  
Tomas Beno ◽  
Anton Milesic Karlsson

The planned material volume to be removed from a blank to create the final shape of a part is commonly referred to as allowance. Determination of machining allowance is essential and has a great impact on productivity. The objective of the present work is to use a case study to investigate how a prior rough milling operation affects the finish machined surface and, after that, to use this knowledge to design a methodology for how to assess the machining allowance for subsequent milling operations based on residual stresses. Subsequent milling operations were performed to study the final surface integrity across a milled slot. This was done by rough ceramic milling followed by finish milling in seven subsequent steps. The results show that the up-, centre and down-milling induce different stresses and impact depths. Employing the developed methodology, the depth where the directional influence of the milling process diminishes has been shown to be a suitable minimum limit for the allowance. At this depth, the plastic flow causing severe deformation is not present anymore. It was shown that the centre of the milled slot has the deepest impact depth of 500 µm, up-milling caused an intermediate impact depth of 400 µm followed by down milling with an impact depth of 300 µm. With merged envelope profiles, it was shown that the effects from rough ceramic milling are gone after 3 finish milling passes, with a total depth of cut of 150 µm.


Author(s):  
A Dugas ◽  
J J Lee ◽  
M Terrier ◽  
J Y Hascoët

High-speed machining gives much potential for increasing the efficiency of the milling operation, but it requires very careful preparation for the milling process to use this potential. A machining simulator has been developed that can analyse dynamic errors due to tool deflections and machine dynamic behaviour using a three-dimensional solid simulation model. This kind of simulator would be a useful tool to apply in high-speed machining where it is necessary to obtain very well prepared part programs considering dynamic errors as well as geometrical errors. In this short communication, an algorithm will be introduced to estimate the dynamic errors caused by machine dynamic behaviour. Specifically, this algorithm predicts real feed rates and tracking errors considering the limits of numerical controllers and machine tools. The efficiency of the algorithm has been verified through several experiments with various tool paths. In addition, the algorithm has been integrated into the machining simulator. Some results obtained from the machining simulator concerning the estimation of tracking errors will be reported.


Author(s):  
Hongji Zhang ◽  
Yuanyuan Ge ◽  
Hong Tang ◽  
Yaoyao Shi ◽  
Zengsheng Li

Within the scope of high speed milling process parameters, analyzed and discussed the effects of spindle speed, feed rate, milling depth and milling width on milling forces in the process of high speed milling of AM50A magnesium alloy. At the same time, the influence of milling parameters on the surface roughness of AM50A magnesium alloy has been revealed by means of the measurement of surface roughness and surface micro topography. High speed milling experiments of AM50A magnesium alloy were carried out by factorial design. Form the analysis of experimental results, The milling parameters, which have significant influence on milling force in high speed milling of AM50A magnesium alloy, are milling depth, milling width and feed speed, and the nonlinear characteristics of milling force and milling parameters. The milling force decreases with the increase of spindle in the given mill parameters. For the effects of milling parameters on surface quality of the performance, in the milling depth and feeding speed under certain conditions with the spindle speed increases the surface quality of AM50A magnesium alloy becomes better with the feed speed increases the surface quality becomes poor. When the spindle speed is greater than 12000r/min, the milling depth is less than 0.2mm, and the feed speed is less than 400mm/min, the milling surface quality can be obtained easily.


2010 ◽  
Vol 129-131 ◽  
pp. 256-260
Author(s):  
Yi Shu Hao ◽  
Chuang Hai ◽  
Xin Xing Zhu

Treating high speed milling theory as the guidance, this paper researched high speed milling process of bracket part based on UG NX. Combined with the structural features of bracket part, three dimensional model is built by UG NX CAD and machining processes are worked out after analysis. UG CAM module was applied to fabricate tool paths. At last, finite element analysis method is introduced to study the processing deformation by UG NX NASTRAN module, based on which measures to restrain processing deformations is advanced and processing sequences are optimized.


Author(s):  
Chenggang Yuan ◽  
Min Pan ◽  
Andrew Plummer

Abstract Digital hydraulics is a new technology providing an alternative to conventional proportional or servovalve-controlled systems in the area of fluid power. Digital hydraulic applications, such as digital pumps, digital valves and actuators, switched inertance hydraulic converters (SIHCs), and digital hydraulic power management systems, promise high-energy efficiency and less contamination sensitivity. Research on digital hydraulics is driven by the need for highly energy efficient hydraulic machines but is relatively immature compared to other energy-saving technologies. This review introduces the development of SIHCs particularly focusing on the work being undertaken in the last 15 years and evaluates the device configurations, performance, and control strategies that are found in the current SIHC research. Various designs for high-speed switching valves are presented, and their advantages and limitations are compared and discussed. The current limitations of SIHCs are discussed and suggestions for the future development of SIHCs are made.


2009 ◽  
Vol 69-70 ◽  
pp. 428-432 ◽  
Author(s):  
Qing Hua Song ◽  
Yi Wan ◽  
Shui Qing Yu ◽  
Xing Ai ◽  
J.Y. Pang

A method for predicting the stability of thin-walled workpiece milling process is described. The proposed approach takes into account the dynamic characteristics of workpiece changing with tool positions. A dedicated thin-walled workpiece representative of a typical industrial application is designed and modeled by finite element method (FEM). The workpiece frequency response function (FRF) depending on tool positions is obtained. A specific 3D stability chart (SC) for different spindle speeds and different tool positions is then elaborated by scanning the dynamic properties of workpiece along the machined direction throughout the machining process. The dynamic optimization of cutting parameters for increasing the chatter free material removal rate and surface finish is presented through considering the chatter vibration and forced vibration. The investigations are compared and verified by high speed milling experiments with flexible workpiece.


2010 ◽  
Vol 34-35 ◽  
pp. 616-620 ◽  
Author(s):  
Zhen Yu Zhao ◽  
Ying Bin Du ◽  
Lei Ming Zhang ◽  
Bai Liu

Based on the amount of tool overhang under different high speed machining experiment, the overhang length on the high speed impact of cutting force in milling process is studies. On the basis, the proposed tool overhang and optimum program are proposed in high speed milling, through the rational use of tools to improve processing capacity of the tool.


2014 ◽  
Vol 565 ◽  
pp. 36-45
Author(s):  
Hadjadj Abdechafik ◽  
Kious Mecheri ◽  
Ameur Aissa

The objective of this study is to develop a process of treatment of the vibratory signals generated during a horizontal high speed milling process without applying any coolant in order to establish a monitoring system able to improve the machining performance. Thus, many tests were carried out on the horizontal high speed centre (PCI Météor 10), in given cutting conditions, by using a milling cutter with only one insert and measured its frontal wear from its new state that is considered as a reference state until a worn state that is considered as unsuitable for the tool to be used. The results obtained show that the first harmonic follow well the evolution of frontal wear, on another hand a wavelet transform is used for signal processing and is found to be useful for observing the evolution of the wavelet approximations through the cutting tool life. The power and the root mean square (RMS) values of the wavelet transformed signal gave the best results and can be used for tool wear estimation. All this features can constitute the suitable indicators for an effective detection of tool wear and then used for the input parameters of an on-line monitoring system. Nevertheless we noted the remarkable influence of the machining cycle on the quality of measurements by the introduction of a bias on the signal; this phenomenon appears in particular in horizontal milling and in the majority of studies is ignored


2009 ◽  
Vol 76-78 ◽  
pp. 624-629 ◽  
Author(s):  
Shan Shan Sun ◽  
W.X. Tang ◽  
H.F. Huang ◽  
Xi Qing Xu

A dynamics model is established considering gyroscopic effects due to high speed rotating spindle-tool system in ultra-high speed milling (USM). The proposed method for predicting stability enables a new 3D stability lobe diagram to be developed in the presence of gyroscopic effects, to cover all the intermediate stages of spindle speed. The influences of the gyroscopic effects on dynamics and stability in USM are analyzed. It is shown that the gyroscopic effects lower the resonance response frequencies of the spindle-tool system and the stable critical depth of cut in ultra-high speed milling.


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