外文翻譯--對(duì)于數(shù)控車床尾座主體的特性分析及其優(yōu)化設(shè)計(jì) 英文版

1、<p>　　Characteristic Analysis and Optimization for The Tailstock Body of The NC Lathe</p><p>　　LU Mo-Wu, Li Ming-Jie</p><p>　　JIANGSU,HUBEI,CHINA</p><p>　　570454645@qq.com,lumo

2、wu@126.com</p><p>　　Keywords: tailstock body; statics analysis; modal analysis; topology optimization; Workbench;</p><p>　　Abstract. The characteristics of the NC Lathe tailstock has great influ

3、ence on the machining accuracy of NC machine tools. Solidworks software is used to establish the tailstock body entity model, then import it into the Workbench software for finite element analysis and conclude its dynami

4、c and statics characteristics. According to the result of the analysis on the topology optimization. Guarantee after optimization, the tailstock body not only can satisfy the requirement of machine tool, the q</p>

5、<p>　　INTRODUCTION</p><p>　　The tailstock is an important part of the CNC lathe, it plays a role in positioning and clamping workpiece. It's static and dynamic characteristics have a direct impact

6、on the machining accuracy and stability. When heavy duty NC lathe machining different parts, tailstock need reciprocating movement to complete the task of clamping, positioning workpiece. So this requires the tailstock w

7、eight is lighter, increase the flexibility of the organization as far as possible. In this paper, HTC100 CNC la</p><p>　　FINITE ELEMENT MODEL</p><p>　　Figure 1 (a) is about HTC100 CNC lathe tail

8、stock body structure, it assembly formed by the upper and lower cabinet as FIG 1 (b), (c) shown in. The bottom of tailstock is fixed on the bed through the slide rail and bolt.</p><p>　　Figure 1 (a) the tail

9、stock box model (b) the upper box model (c) the lower box model HTC100 horizontal CNC lathe tailstock is casted by the HT300. The modulus of HT300 is</p><p>　　1.43E11Pa, Poisson ratio is 0.27 and density is

10、7340Kg/m3.</p><p>　　Meshing is an important part of the finite element analysis. This paper chooses Patch in Conforming method which belongs to the Tetrahedrons method to mesh the tailstock box model. The re

11、asons why this method is selected are that it is fast and applicable to the complex geometry;</p><p>　　All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or b

12、y any means without the written permission of Trans Tech Publications, www.ttp.net. (ID: 128.119.168.112, Univ of Massachusetts Library, Amherst, USA-11/07/15,21:55:17)</p><p>　　42Development of Applied Eng

13、ineering Sciences</p><p>　　Approximate size in the key areas can be refined. The finite element model is obtained after mesh is shown in Figure 2, The number of nodes model is 55973 and the total number of u

14、nit is 32024.</p><p>　　Figure 2 The finite element model of box.Figure 3 The boundary conditions of box</p><p>　　It must be applied boundary conditions on the box in the ANSYS before analyzing

15、statics and dynamics of the tailstock box, including the force, torque and support surface. The tailstock body internal stress mainly comes from gravity of parts. Besides the gravity of the internal parts, the tailstock

16、box is also got the cutting force and moment during the machining process.</p><p>　　Taking the shaft machining as an example, According to the empirical data, the tailstock clamping force is 5.28KN, the maxi

17、mum cutting force is 60KN. The main cutting force is 53.4KN, back force is 18.6KN and feeding force is 20.4KN. After stress analysis, the force and torque come from tip is got as follows: Fx =560N, Fy =1572350N, Fz =1512

18、0N, M =8811N.m. Apply these forces and moments</p><p>　　to each surface of box, The tailstock body fixed on the bed, so the bottom of the box body is got by fixed constraint. Boundary conditions are applied

19、in the Workbench as shown in Figure 3.</p><p>　　FINITE ELEMENT ANALYSIS</p><p>　　The result of the static analysis has an important reference value to optimize the structure of the box body. Ana

20、lysis of static images as shown in Figure 4, the maximum displacement of the box body is 1.23E-004m, the maximum stress is 4.44E+007Pa. The results show that the maximum displacement of box is small, it can satisfy the p

21、recision demand. The ultimate stress of HT300 is 300MPa. The maximum stress of tailstock box is far less than the limited material stress, Box rigidity meets the requi</p><p>　　During the process, machine to

22、ols generate periodic variational excited force by the interaction of noise and vibration. It's easy to cause the resonance when the frequency of excited force is the same or integer with the natural frequency of str

23、ucture. It will reduce the machining precision and stability of machine tool. So it is necessary to carry out the modal analysis of the tailstock box.</p><p>　　Figure 4 The displacement and stress nephogram

24、of tailstock body</p><p>　　Advanced Materials Research Vol. 103743</p><p>　　After modal analysis of box in the ANSYS, the first six-order modal is concluded as shown in table I. The maximal spe

25、ed of spindle of HTC100 CNC lathe is 200rpm and the frequency is 3.33Hz. It can be seen that the excitation frequency of the tailstock is far less than itself first six-order frequency from table 1.</p><p>　

26、　TOPOLOGY OPTIMIZATION</p><p>　　Topology optimization is refers to find the best solution of structural materials used to make the target volume (overall stiffness, natural frequency etc.) stable under given

27、 constraint condition. Using "Shape Optimization" function in Workbench to finish the tailstock box topology optimization. The optimization goal is set to 5 percent, then solve it, optimization results as shown

28、 in Figure 5.</p><p>　　Figure 5 The topology optimization nephogram Figure 6 The geometry structure after optimization</p><p>　　As the red resectable area is irregular, the complexity of techno

29、logy and stress distribution must be considered in the actual processing. So it is impossible to remove all red area. Cut off the red area in regular geometry in Solidworks, then quality reduces 1250.4Kg. The geometric s

30、tructure after optimization as shown in Figure 6.</p><p>　　Make the finite element analysis on the optimization scheme and the displacement, stress nephogram as shown in Figure 7. The maximum displacement of

31、 box is 1.19E-004m and the maximum stress is 4.57E+007Pa after optimization. Modal analysis on the box body after structure optimized is carried out and get the low order mode as shown in table 2.</p><p>　　F

32、igure7 The displacement and the stress nephogram after optimization</p><p>　　Make statics and dynamics analysis on the optimized box structure, it can be seen the tailstock body still meet the stiffness requ

33、irement and machining accuracy after optimization. Moreover, the quality reduced, the movement inertia enclosure and the control performance improved.</p><p>　　44Development of Applied Engineering Sciences&

34、lt;/p><p>　　CONCLUSION</p><p>　　Doing topological optimization to the tailstock box in Workbench, the maximum displacement, maximum stress and the low frequency basically unchanged after optimizati

35、on design of the tailstock box. It meets the design requirements and the quality is reduced by 5%.It makes the tailstock movement more flexible.</p><p>　　Using finite element software to analyze the products

36、 can save the cost of manufacturing prototype and testing. Getting the main properties of the product in the software, it could provide optimized structure and size.</p><p>　　REFERENCES</p><p>　

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41、ering Sciences</p><p>　　10.4028/www.scientific.net/AMR.1037</p><p>　　Characteristic Analysis and Optimization for the Tailstock Body of the NC Lathe</p><p>　　10.4028/www.scientific.