scholarly journals Design and Optimization of Variable Pitch End Mills Based on Dynamic Balance Accuracy

Author(s):  
Wanying Nie ◽  
Minli Zheng ◽  
Shicheng Xu ◽  
Yuexiu Liu ◽  
Haibin Yu

Abstract Variable pitch end mills are widely used in the high-speed milling process due to having better vibration reduction properties. However, because of the unequal pitch angles and the asymmetrical structure of end mills, there are principle error, poor dynamic balance accuracy, and serious tool vibration problems in the milling process. In order to improve the dynamic balance accuracy of variable pitch end mills, the structure of the end mill is designed and optimized based on the minimum eccentricity criterion in this paper. Firstly, by analyzing the dynamic balance of variable pitch end mills, the relationship between it and eccentricity is defined, and the end section model and the centroid equation are developed through the structure design of end mills. Then, the optimization method of variable pitch end mills is analyzed, the eccentricity decreases from e0= 150um to e'0 = 3um based on this method. the structure of the end mill is optimized to meet the design criteria, which improves the balance accuracy level of end mills. Finally, through the modal analysis for the optimized structure of the variable pitch end mill, the maximum relative displacement in the mode is reduced by about 17%, it is verified that the optimized end mills have better dynamic performances, which is of great significance for alleviating the cutting vibration and improving the cutting stability.

2011 ◽  
Vol 314-316 ◽  
pp. 599-602
Author(s):  
Qing Hua Song ◽  
Xing Ai

The strong demand for increasing productivity and workpiece quality in milling process makes the machine-tool system operate close to the limit of its dynamic stability. Milling cutters with variable pitch angles can be very effective in improving stability against chatter for certain speed ranges, which will be predicted by the model presented here. The present paper deals with the design of structural geometry of variable pitch end mills in detail. Based on the analysis of tooth engagement factor, which is expressed and extended in the paper, an approach is proposed to design variable pitch end mill with high milling stability. The certain speed ranges with high milling stability are given.


2006 ◽  
Vol 315-316 ◽  
pp. 474-480
Author(s):  
Dun Wen Zuo ◽  
Yoshihiro Kawano

End mills with small diameter have found their wide application with the development of high-speed cutting. It becomes more and more important to develop effective methods to monitor and control the milling process with small end mills. In this paper, a measuring system of projection image for small end mills is introduced, and the application of the projection image to monitor the behavior of the end mill is discussed. It is found that for static state of the end mill, the measurement accuracy can be easily controlled within 1 μm. When the end mill rotates, it is not so difficult to control the accuracy within 3 μm. By using of the change in image width, the radial wear of end mill can be predicted. On the other hand, if the centre shift of the image is pre-measured, the deflection of the end mill during cutting can be predicted.


2016 ◽  
Vol 10 (5) ◽  
pp. 767-772 ◽  
Author(s):  
Amine Gouarir ◽  
◽  
Syuhei Kurokawa ◽  
Takao Sajima ◽  
Mitsuaki Murata ◽  
...  

This paper presents a method for in-process detection of tool wear in square end mills. The developed high-speed tool wear detection system uses the contact resistance between the tool and workpiece as a gauge to monitor the progression of tool wear. The electrical resistance decreases with an increase in contact area on the tool flank. In the experiments conducted in our previous study, the target was the face milling process. In the present study, the experiments were conducted on down cut milling with a square end mill. The results are presented based on the observations made on the relationship between the area of tool flank wear and tool-work contact resistance. In conclusion, the results of the experiment show that the present tool wear detection system is effective as an in-process tool wear detection system for square end mills.


Author(s):  
Eyyup Aras ◽  
Derek Yip-Hoi

Helical milling is a 3-axis machining operation where a cutting tool is feed along a helix. This operation is used in ramp-in and ramp-out moves when the cutting tool first engages the workpiece, for contouring and for hole machining. It is increasingly finding application as a means for roughing large amounts of material during high speed machining. Modeling the helical milling process requires cutter/workpiece engagements (CWEs) geometry in order to predict cutting forces. The calculation of these engagements is challenging due to the complicated and changing intersection geometry that occurs between the cutter and the in-process workpiece. In this paper we present a geometric modeling methodology for finding engagements during helical milling with flat end mills. A mapping technique has been developed that transforms a polyhedral model of the removal volume from Euclidean space to a parametric space defined by location along the tool path, engagement angle and the depth-of-cut. As a result, intersection operations are reduced to first order plane-plane intersections. This approach reduces the complexity of the cutter/workpiece intersections and also eliminates robustness problems found in standard polyhedral modeling and improves accuracy over the Z-buffer technique. The reported method has been implemented and tested using a combination of commercial applications. This paper highlights ongoing collaborative research into developing a Virtual Machining System.


2021 ◽  
Author(s):  

Aspects of vibration reduction during machining on metal-cutting machines to improve the quality of machined surfaces at moderate and high-speed cutting modes are considered. End mills with damping elements made of different materials, which provide the control of tool rigidity, are developed. Keywords: vibrations, end mill, vibrations, machined surface, damping. [email protected]


2012 ◽  
Vol 6 (4) ◽  
pp. 542-545 ◽  
Author(s):  
Katsumi Naganuma ◽  
◽  
Masato Mori

Molding technology is one way of producing the micro-precision parts required by various industries. To Advance this molding technology, various elemental technologies related to materials, construction and machiningmethods are evolving together. One of these elemental technologies is milling by end mill. Further research and development of end mill is underway in response to improvement and requirement of molding technologies. There are various demands for end mills such as improvement of tool life and stable machining quality. Here we report the small diameter cBN end mill, developed as a tool to provide with stable machining accuracy with long tool life for high hard materials. We report the investigations and characteristics at the time of development and show the machining test.


2011 ◽  
Vol 314-316 ◽  
pp. 1167-1170
Author(s):  
Zhi Wei ◽  
Ji Hong Jia ◽  
Mei Lin Gu ◽  
Chao Zuo ◽  
Xing Zhen Jin

This paper describes the experimental system of milling force, the tool geometrical feature and the certain experimental condition in the section of experimental case, which also makes an explanation about the designing of experimental case and the analysis of the experimental data. It also represents the relationship between coefficients associated with the milling process and the milling force applied on the tool in detail. A finite element method is used to make an explicit analysis on the stress and deformation of the milling tool under the application of certain milling force. Finally, a summary is made to conclude the study and its results.


2015 ◽  
Vol 1089 ◽  
pp. 350-353
Author(s):  
Wei Bo ◽  
Guang Yu Tan ◽  
Lin Lin Guo ◽  
Guang Hui Li

Cutting temperature is a key factor in impacting the solid carbide end mill’s life, the rule of solid carbide end mill temperature field is the research focus. In this paper, the solid carbide end mill helical side edge is regarded as a helical coil heat source, the tool chip friction surface is considered as a surface heat source which consists of countless helical coil heat source. Based on heat source method, the model of continuous dynamic temperature field simulation of a solid carbide end mills cutting process is established.


2014 ◽  
Vol 599-601 ◽  
pp. 381-384
Author(s):  
Li Lun He ◽  
Zhi Bing Liu ◽  
Xi Bin Wang ◽  
Wei Wei Lv

For the problems about design and manufacture of the variable pitch tapered end mills, this study proposes a three-dimensional parametric design method of variable pitch mill. Firstly the equation of calculating the optimal angle between the pitch was presented .Considering existing different patches between two cutting edges, helix edge curve and cross-section groove model of tapered end mill were established .Secondly, mathematical expression of ball end teeth for tapered mill was derived, and all points data of tapered mill surface can be determined by established model. Through the graphical representation, the points set are translated into a solid model.


2007 ◽  
Vol 10-12 ◽  
pp. 909-912
Author(s):  
H.B. Zhang ◽  
L. Zhou ◽  
Ying Xue Yao

For rigid rotor that widely applied in gyroscopes, high precision dynamic balance is very important. The paper introduces a dynamic balance method for drum-shape gyroscope rotor: the rotor is supported by gas bearing; detecting the displacement of three points on the drum-shape rotor’s end-plane, obtaining its normal direction. Then according to geometrical relation of geometric axis and polar inertia axis, the dynamic trace of the rotor can be obtained, and the rotor’s mass imbalance is calculated. Experiment result shows that the method has high balance accuracy, particularly suit for high-speed gyroscope rotor whose mass imbalance is small.


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