機械設(shè)計外文翻譯--自由鍛造液壓機的動態(tài)行為（英文）

1、 Procedia Engineering 100 ( 2015 ) 885 – 890 Available online at www.sciencedirect.com1877-7058 © 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (ht

2、tp://creativecommons.org/licenses/by-nc-nd/4.0/).Peer-review under responsibility of DAAAM International Vienna doi: 10.1016/j.proeng.2015.01.445 ScienceDirect25th DAAAM International Symposium on Intelligent Manufactur

3、ing and Automation, DAAAM 2014 Dynamic Behavior of the Hydraulic Press for Free Forging Karel Raz*, Vaclav Kubec, Milan Cechura University of West Bohemia, Faculty of Mechanical Engineering, Regional Technological Instit

4、ute, Univerzitni 8, 306 14 Pilsen, Czech Republic Abstract Work on hydraulic presses is defined by a static forging force. This force may have in special cases of forging properties of dynamic and shock load. Commonly u

5、sed hydraulic presses can use speed-forging with speed up to 180 strokes per minute. Our goal is to compare different types of frame designs used for hydraulic forging presses. Result is determination of the suitability

6、 of each supporting structures for these special operations. Comparing is made using FEM modal analysis. The performed modal analysis show needs for lowering of first critical natural frequency. An overview of these fr

7、equencies is shown in attached tables. © 2015 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of DAAAM International Vienna. Keywords: hydraulic press; free forging; modal analysis 1. Main

8、 Text The task of every research group is to solve their research topics at least one step ahead of the current needs of the industry. This is connected with prediction of development in this area. As part of the Unive

9、rsity of West Bohemia in Pilsen, we tried in advance to deal with it. In cooperation with industry we tried to find tasks in the field of metal forming machines. Dynamic behaviour is one of the key problems in the des

10、ign of hydraulic presses for free forging. This topic is relevant because customer needs hydraulic press for forging with higher number of strokes per minute. Different designs of hydraulic presses were not compered s

11、eriously up to now. We decided to perform monitoring of individual design options, and then make precise modal analysis. This analysis is done on individual * Corresponding author. Tel.: +42-037-763-8254. E-mail addres

12、s: kraz@rti.zcu.cz © 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility o

13、f DAAAM International Vienna887Karel Raz et al. / Procedia Engineering 100 ( 2015 ) 885 – 890 Fig. 2. a,b Hydraulic press 3 and 4. 3. Modal analysis For theses designs of hydraulic presses, we prepared a virtual

14、models, which includes all the important parts of the frame (columns, anchor nuts, working cylinders, plungers). Movable members (movable crossbeam) are in a defined position, which is based on the common dimension of f

15、orged piece at these large hydraulic presses. To include all influences was into FEM model added 0D element (point) [7, 8] with mass property equal to mass of working liquid. The simulation includes definitions of cont

16、acts in areas of relative motion of the parts. Among lower and upper anvil is defined boundary condition which allows their movement in horizontal direction. Other directions of deformation were among both anvils coupl

17、ed. Before evaluation of the frequency was done static calculation, which gives results of initial state of pre-stressed frame. The results of this calculation were then used as input conditions for modal analysis. [4,