• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • Tagged with
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Využití moderních technologií při výrobě ploché součásti z plechu / Use of modern technologies in the production of flat sheet metal parts

Kohoutová, Zuzana January 2011 (has links)
The final work elaborated in the scope of master's studies of the branch 2303T002 submitted use of modern technologies in the production of flat sheet metal parts from the material 11 373. Work is set for cold shaping of metal by means of cutting. Production on sequence shearing tool is based on series 350 000 pieces per year. Universal hydraulic press CUPS 63 DEU with shearing force 630 kN is selected for realization. Work is also focused on the production of the same components using plasma, laser and water CNC equipment and the subsequent economic evaluation of all variants of the production. In enclosure there is drawing documentation for cutting tool.
2

VLIV PARAMETRŮ VYSOKOTLAKÉHO OSTŘIKU NA KVALITU ODOKUJENÍ / EFFECT OF HIGH PRESSURE WATER BEAM PARAMETERS ON QUALITY OF DESCALED SURFACE

Vavrečka, Lukáš January 2011 (has links)
This work is focussed on hydraulic descaling of hot surfaces. Hydraulic descaling is a process when layers of oxides are removed from hot steel surfaces during continuous rolling. High pressure water beam is used. Quality of descaled surfaces is important for final quality of rolled product. Insufficient descaling causes drop of final quality, degradation of rolls and lost of yields. High-pressure water beam has two effects on a scale layer. The first effect is mechanical caused by impact pressure. The second one is a relatively intensive thermal shock depending on a set of parameters (water pressure, nozzle type, distance from the surface, inclination angle, speed of product moving). There are a lot of theories about principles of scales removing. Main task of this work is to make it clear which theory is acceptable and which is just ,,theory”. For this purpose mathematical modelling and experimental work were used. In experimental part, three types of experimental measurement were done. First one, measurement of dynamical effect of water beam – impact pressure. Second one, measurement of temperature drop when a product is passing under the nozzle. Measured data (temperatures) from this measurement are evaluated with inverse task and heat transfer coefficient is obtained. And the third experimental measurement is simulation of whole process of descaling. Quality of descaled surfaces is valuated according to amount of remained oxide scales. Data from firs and second experimental measurement are used as boundary conditions for mathematical modelling. For mathematical simulations, FEM (finite element method) system ANSYS was used. Obtained data from experimental measurement were applied on 2D and 3D models of basic steel material with layer of scale. Influence of theses data on final temperature, stress and strain fields were observed.

Page generated in 0.0769 seconds