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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.
161

Návrh výroby kotvícího prvku solárního kolektoru / Manufacturing of the anchoring element of a solar collector

Svobodová, Helena January 2017 (has links)
In this master's thesis the proposal of the production technology of component – solar collector anchor element from steel 1.0038 (11 375) quality, 5 mm thickness is solved. For the manufacturing of the assigned part the shearing and bending technology and a progressive forming tool including a suitable forming machine of 8,000 kN rated power is selected. The proposed method of production is laid down by a technical-economic evaluation with respect to the production series of 150,000 units per year. The solar collector anchor element serves to hold the frame for the solar vacuum tube collector. In the scope of this master's thesis, an assessment of the current production method, including the selection of a suitable semi-finished product for production, was also carried out and their optimization was proposed.
162

Lubricants for Hot Stamping of Aluminum: Evaluation of Tribological Behavior and Cleanability

Rodriguez Leal, Barbara Maria January 2021 (has links)
Working at elevated temperature has its challenges due to the high level of complexity whenthe tribosystems operate under harsh conditions, commonly resulting in an increase on thefriction and thermal softening that goes into severe adhesion, severe abrasion and materialtransfer. Despite considerable research, there is a lack of research on tribology applied to hightemperature processes.  The aim of this project is to understand the tribological behavior of tool steel sliding againstaluminum under lubrication conditions working at high temperature. Salt-based, graphite-based, and polymer-based lubricants were evaluated as they are commonly used for aluminum forming. The cleanability of the lubricants after being subjected to elevated temperatures is also studied. High temperature tribological tests were carried out in a reciprocating sliding flat-on-flat configuration for 15 seconds. Optical microscope, SEM and EDS were performed to analyze the specimens after the tribological tests. Then a cleanability study was done to evaluate the cleanability of the lubricants and the effect of temperature on the cleanability of the lubricant. The concentration of the lubricants played an important role in the lubricant’s friction stability and dispersion, particularly for the polymer-based and graphite-based lubricants. Under the tested conditions the salt-based lubricant was ineffective as it showed high and unstable friction. The 10 wt.% polymer-based lubricant concentration presented severe adhesion and material transfer from the aluminum onto the tool steel.  The effect of temperature on the cleanability of the lubricants was correlated to the temperature in which the lubricants start to degrade. Nevertheless, the best cleanability was achieved when using ethanol as a cleaning agent in combination with high pressure spraying, and wirebrush techniques. Mild and high alkaline agents had poor cleanability abilities resulting insurface damage and corrosion on the tool steel.
163

Výroba dveřní petlice sdruženým nástrojem / Door latch manufacturing by compound tool

Petřek, Pavel January 2011 (has links)
The project drawn up within engineering studies, field M-STG, presents a design for processing a single part – the part is made of sheet steel number S195T by shearing and bending. On the basis of literary study was design compound tool which is working in three steps. The tool is fixed in eccentric press LE 250 with nominal force 25000 kN. Blanking punch and blanking die are made from tool steel 1.2379 according the drawing documentation.
164

Návrh postupu výroby součástí pro váleček pásového dopravníku / Proposal of the manufacturing procedure for the parts of belt conveyor roller

Pavelek, Michal January 2011 (has links)
The project, which has been elaborated within the framework of Master's Degree in Manufacturing Technology (2303T002), processes a technology proposal for the production of stamped part čelo from DD14 material, with a thickness 4 mm, with production quantities of 100 000 pieces per year, in cooperation with the company UNIRON Ltd. Based on the literature study of deep drawing without thinning of the walls and calculations, production of the part of simple single-function drawing tools was proposed. The first three operations performed on a PYE 100 S/1 hydraulic press and the last calibration operation carried out on a LEK 250 eccentric press. The semi-finished product is blank with a diameter of 195 mm, produced in a simple cutting die. The cutting die is designed for both the material in the form of a sheet metal strip in coils and cut strips of metal sheet, which is associated with the use of two eccentric presses of the LEK 250 and LE 400C types. The proposed manufacturing process was simulated in the PAM-Stamp 2G software, in which the influence of the radius the functional parts of tools to change the thickness of the material is further simulated. The part of the project is a technical and economic evaluation, in which the price of one piece of the product and production quantity at which production becomes profitable was rated.
165

Výroba součásti "Kroužek" plošným tvářením / Production single parts "Ring" from sheet metal

Stejskal, Luboš January 2012 (has links)
This thesis elaborated within a master degree in 23-03-T002 line, introduces a suggestion of production technology of part „Ring“ by sheet metal forming out of deep-drawing steel W.Nr. 1.0338. Supposed production amount is 250 000 pieces per year. Based on a literary study of problematic of sheet forming for this required part regarding production series, technologies of this of deep drawing and cutting were chosen. According to performed technological calculations, a production process of seven operations was designed. A sequence automatic machine Paust 40 (VVB WMW), was cousin for this suggested process. This machine is particularly appointed for big series and wholesale production of impressions of sheet metal. It is equipped with mechanization and therefore creates a fully automatic line. A tool was designed for this chosen type of machine. Project includes economical evaluations of elaborated of production technology.
166

Výroba kotevního prvku / Manufacturing of wall clamp

Šobáň, Pavel January 2014 (has links)
The wall clamp is used for attaching columns or pillars to a concrete foundation. It is made from structural steel 11 375 in the form of sheets with a thickness of 4 mm in the production run of 150 000 pcs/year. A combination of shearing and bending technologies in a progressive forming tool was selected from various options as the most appropriate. On the basis of structural and technological calculations, an instrument was designed, for which the technical documentation was elaborated. Due to the total forming force and work, the forming machine LDO 800 A/S from Šmeral Brno a.s. was selected as the manufacturing machine. The production cost per one part 53.66 CZK was determined using economic evaluation; based on the break even point, the production becomes profitable for the production run with the minimum number of 13 065 pcs.
167

Výroba krytu / Production of casing

Hájek, Pavel January 2014 (has links)
This master’s project describes a proposal for manufacturing technology of a horizontal boring machine case. This case is manufactured by HESTEGO a.s. from a DC01 steel sheet, which is 2 mm thick and its production series is 200 pieces a year. Punching and bending were chosen as the most suitable methods from the considered manufacturing technologies. The theoretical part of the thesis includes a study of the chosen manufacturing technologies. Based on the analysis of the technological calculations and the available tools in the manufacturing company, a technological procedure was designed and these machines were chosen: punching machine TruPunch 5000 a servo-electronic press brake SAFAN E – BRAKE 100–3100. Technical and economical evaluation is also included in the proposal.
168

Návrh výroby krytu vany regulátoru / Production of Cover of Regulator Tank

Kudláč, Lukáš January 2017 (has links)
This master’s thesis deals with suggestion of production of sheet metal cover in Limid Mohelno s.r.o. Piece serves as cover of regulation device of rail vehicles with visual function and it’s manufactured from corrosion-resistant steel ČSN 17 240 with thickness 1 mm. Esthetical impression is ensured by grinded surface K240. The master’s thesis includes literary studies and problems of chosen technologies, technological calculations and choice of machines including tools. As the best manufacturing technology was chosen punching on TruPunch 1000 and bending on press brake SafanDarley E-Brake E-100. Technical and economical evaluation was made based on selected technology and compared with another manufacturing options.
169

CAE Methoden in der Einarbeitungsphase der Blechumformung

Szyszka, Jörg, Süße, Dietmar, Schöne, Christine January 2012 (has links)
Aus der Einleitung: "Um Kosten in der Produktentwicklung weiter zu minimieren und gleichzeitig die Qualität der zu fertigenden Produkte zu gewährleisten, nehmen virtuelle Methoden in der Produktentwicklung einen immer größeren Stellenwert ein (Stelzer & Eigner, 2009). An die Maßhaltigkeit von umgeformten Blechteilen werden ständig höhere Anforderungen gestellt. Die Ursachen für Maßabweichungen an gefertigten Blechteilen resultieren maßgeblich aus den Berechnungsmodellen, die das System Werkzeug-Blechteil-Umformmaschine bisher in der Virtuellen Produktentwicklung noch nicht vollständig und exakt abbilden können. Mehrere Zyklen händischer Änderungen an den Umformwerkzeugen sind heute noch die Regel. Dieser Prozess wird bei der Blechumformung als Einarbeitungsphase bezeichnet und wird von Spezialisten des Werkzeugbaus unter Nutzung von unscharfem Erfahrungswissen durchgeführt. Der Zyklus der manuellen Einarbeitungsphase im Bereich des Werkzeugbaus steht den wirtschaftlichen Forderungen zum schnelleren Serienanlauf und zur Kostensenkung entgegen. Hier kann die Verkürzung des Einarbeitungsprozesses dienlich sein."
170

Rückfederungsreduzierung durch simulationsbasierte Methodenoptimierung in der Blechumformung

Sacher, Patrick 21 April 2017 (has links)
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.

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