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  • 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.
51

Rückfederungsreduzierung durch simulationsbasierte Methodenoptimierung in der Blechumformung / Springback compensation in sheet metal forming by optimizing methods of simulation

Sacher, Patrick 24 August 2017 (has links) (PDF)
Bisherige Bemühungen zur Reduzierung der Rückfederung von Blechbauteilen begrenzten sich hauptsächlich auf die Gestaltung der letzten Formgebungsstufe. In der vorliegenden Arbeit wird ein innovativer Ansatz zur Erhöhung der Maßhaltigkeit durch die Modifikation der Vorziehstufe untersucht. Dabei wird auf Grundlage eines beispielhaften Industriebauteils ein Demonstrator mit einer offenen und einer geschlossenen Kontur entwickelt. Durch die Abbildung der Herstellungsmethode in der Simulation (FEM) lässt sich die Rückfederung beurteilen. Durch die Charakterisierung des Werkstoffverhaltens wird die Qualität der Simulation gesteigert, da die Materialkennwerte (Fließkurve & Grenzformänderungskurve) für die Simulation genauer spezifiziert werden können. Es erfolgt die Variation der Vorziehstufe hinsichtlich geometrischer (Radius & Grad der Vorziehstufe) und prozesstechnischer Parameter (Niederhalterkraft & Schließabstand), sodass nach der Auswertung der Rückfederungsergebnisse Gestaltunghinweise erarbeitet werden. Die Validierung der Simulationsergebnisse wird vorgenommen, indem die Bauteile real hergestellt werden. Dadurch ist es möglich, die Rückfederungen der Simulation und der realen Herstellungsmethode zu vergleichen und die Gestaltungshinweise zu bewerten. / Approaches to reduce springback of sheet metal parts are mainly focused on the last forming stage. This study deals with modifications made on the pre-drawing stage so that an increased dimensional accuracy results. A demonstrator with an open and a closed contour is developed based on an exemplary industrial part. The assessment of springback is conducted by incorporating the manufacturing method into simulation (FEM). To increase the quality of the simulation the characterization of materials is set and hence more information about material properties (flow curve and forming limit curve) is specified. Variations of geometric (radius & proportion of pre-drawing stage) and process parameters (blankholder force & closing distance) are made which purpose the development of design guidelines after evaluation. The simulation results are validated by producing real sheet metal parts. The design guidelines will be feasible/can be assessed if the comparison of the springback results converges between simulation and reality.
52

Advances on Geometrical Limits in the Deep Drawing Process of Paperboard

Hauptmann, Marek, Kaulfürst, Sebastian, Majschak, Jens-Peter 06 September 2018 (has links)
The geometrical limits of the deep drawing process of paper to advanced shapes are not known. This report examines the technological limits of convex elements of the base shape in relation to the drawing height and shows the material behavior in the bottom radius of 3D shapes with regard to special material properties. In the bottom radius, non-compressed wrinkles occurred due to the in-plane compression, but wrinkles were reduced by an increased blank holder force or tool temperatures and improved extensibility or in-plane compressive strain. The forming ratio during deep drawing (drawing height related to base diameter) was increased to a value of more than 1 by a blank holder force, which increased with the drawing height such that the initial blank holder force was reduced concurrently. Straight sections in the base shape reduced the risk for ruptures in the edge radii of rectangular shapes, producing a forming ratio in these radii of 2.5. The forming ratio was further supported by a pattern of creasing lines at the blanks with a radial orientation and a number near the expected maximum number of wrinkles. The spring-back at rectangular shapes mainly depended on the drawing height and edge radius.
53

Výroba odvíčkovací vaničky / Production of uncapping tray

Čudová, Monika January 2017 (has links)
The project elaborated design of technology production of the extract - tray made of stainless steel 17 240. Based on literary study of deep drawing together with calculations, was designed drawing in instrument with holder. The drawing instrument make use of standardised components and it is solving forms to make up stand fitting to hydraulic press CYS 320, with nominal tensile force 3200 kN. Drawing punch and drawing die are produced from high alloyed steel 19 573 heat-worked according to drawing documentation.
54

Výroba anemostatu / Production of anemostat

Bíba, David January 2019 (has links)
The thesis handle design of part of anemostat in size of series 15000 pcs/year. Due to conus shape and dimensions of part was chosen out of quantity of manufacturing processes a technology of deep drawing without a thinnig of 1mm thick DC04 steel. The resulting solution is progressive tool which concatenate four operations of deep drawing process. The drawing tool make use of standardised components. The design contain progressive tool including drawing documentation. Hydraulic press CTH 400 with nominal force 4000 kN is used for mentioned procedure.
55

Výroba pouzdra zapalování / Manufacturing of the Ignition Case

Jelínek, Dan January 2020 (has links)
The thesis deals with the design of the production of Ignition case. Component is a hollow cover of one channel ignition device, produced by the PBS Velká Bíteš company. It has a constant wall thickness of 0,5 mm and production rate is 15 000 pieces per year. Technology of deep drawing with solid forming tool was picked out of several considered production variants. DC05 deep drawing steel is the material of choice. Based on technological calculations, number of drawing operations needed and forming force was established. Based on those parameters, hydraulic press ZH 10 produced by the Presshydraulika s.r.o. company was chosen for the task.
56

Výroba napáječky / Production of drinker

Vašíček, Jan January 2020 (has links)
The diploma thesis of the master's study in the field of M2I-K presents a design of a hollow rotating part made of metal sheet with a tapering bottom. Deep drawing technology was chosen as the best suited option for production without thinning the wall. Stainless steel was chosen as a source material for production parts in compliance to ČSN 172 40. The drinker is produced by three drawing operations where each operation is performed separately on a standalone press CTH 250 developed by ŽĎAS a. s. A sheet measuring 1500 x 3000 x 1 mm with diameter 428 mm was evaluated as the most economically viable for production of a semi-finished product – rondel. For one year production produced in a series of annual volume 100,000 pieces.
57

Výroba krytu kloubu přívěsného vozíku / Manufacturing of Trailer Connecting Joint

Vahala, Jiří January 2021 (has links)
The project elaborated design of technology production of the trailer connecting joint from the deep drawing sheet iron 11 320. Pursuant to of the literary pursuit a problem of the deep drawing and calculation was designed progressive tool concatenate four operations. The lower ejectors are using for ejecting components. The drawing instrument especially made of non-standardised components and it is designed for use on a hydraulic press CTH 250, with nominal tensile force 250 kN. Drawing punch and drawing die are produced from alloyed instrumental steel 19 436 heat-worked according to drawing documentation. The technical and economical evaluation was focused on the forming cost, which is 2 922 893 CZK in total.
58

Výroba součásti plošným tvářením / Production single parts from sheet metal

Hrnčál, Zdeněk January 2008 (has links)
Project elaborate in terms of engineering studies branch 2303T002 submits proposal technology of production single parts from deep drawing press steel metal plate 11 305.21. On the basis literary study problems blanking, deep drawing and calculations was designed drawing in instrument with holder, to extrusion components serves lower ejector. Combination tool is set on hydraulic press CTH 250 with nominal tensile by force 250 kN. Drawable tools (drawing punch, drawing die) and shear pin tools (blanking punch, blanking die) are made from instrumental steels 19 436.3, heat treated condition to drawing documentation.
59

Svařovaní ocelí s rozdílnými vlastnostmi pomocí Yb-YAG laseru / Weldig of the different type of steel by the Yb-YAG laser.

Kopecký, Lukáš January 2012 (has links)
Diploma theses is focused on welding experiment of maraging steel by use Yb-YAG laser. Experimet is based on testing of combination steel 11321 and maraging steel. Domex420MC, Domex720MC a QSE380. In theoretical part there are described laser technology of welding, weld defect, maraging steel and inspection of welded joints. In experimental part there are porposed test and made mechanical test of weld as transverse tensile test, bend tests, Erichsen cupping test, Vickers hardness test and makroscopic and microscopic examination of welds. In conclusion there are analysis of the experiment results.
60

Výroba tělesa olejového filtru / Manufacturing of oil filter

Prokop, Karel January 2013 (has links)
This thesis deals with the proposal of an oil filter body manufacture. The oil filter body is a rotational part made of DC02 deep drawing steel. With respect to the material, geometry and the size of the production, a deep drawing technology which does not consider wall thinning, was chosen. It was decided about necessity of five drawing operations. Suitable presses for a notching line and the very drawing were selected. Next part of the thesis is given to the design of the rolling tool construction. A drawing die for the first operation is described in details, including the controls and drawings. The economic part compares variants with the requirements of monthly production of 50 000, 180 000 and 350 000 pieces respectively. Due to the economic study, the production of 180 000 pieces per month was chosen.

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