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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.
131

Controlling the dynamic characteristics of machining systems through consciously designed joint interfaces

Frangoudis, Constantinos January 2014 (has links)
The precision of machining systems is ever increasing in order to keep up with components’ accuracy requirements. At the same time product variants areincreasing and order quantities are decreasing, which introduces high demands on the capability of machining systems. The machining system is an interaction between the machine tool structure, the process and the control system and is defined in terms of capability by the positional, static, dynamic and thermal accuracy. So far, the control of the machining system, in terms of static and dynamic stability is process based which is often translated into sub-optimum process parameters and therefore low productivity.This thesis proposes a new approach for control of the machining systemwhich is based on the capability to control the structural properties of themachine tool and as a result, controlling the outcome of the machining process.The control of the structural properties is realized by carefully designed Joint Interface Modules (JIMS). These modules allow for control of the stiffness and damping of the structure, as a result of tuning the contact conditions on the interface of the JIM; this is performed by control of the pre-load on the interface,by treatment of the interface with damping enhancing materials, or both. The thesis consists of a presentation of the motivation behind this work, the theoretical basis on which the proposed concept is based and a part describing the experimental investigations carried out. Two prototype JIMs, one for a milling process and one for a turning process were used in the experimental investigations that constitute the case studies for examining the validity of the proposed concept and demonstrating its applicability in a real production environment. / <p>QC 20140611</p> / EU FP7 POPJIM
132

Porovnání nosných struktur obráběcích strojů z tradičního a netradičního materiálu / Comparison of machine tool structures from traditional and non-traditional materials

Tichý, Antonín January 2019 (has links)
The topic of this diploma thesis is compare materials in machine tool structures. The introduction part is about literature retrieval in field of constructional components in machine frames. There are discribe the indiviual parts of machine structures their properties and influence, witch affect their static toughness, stabilty and accuracy of the whole milling machine. The most important part is focused to the materials witch constructions of machine are made from. The main of this thesis is a practical part, where is designed the own model of milling machine solved on the basis of experiences gain. The important choose was appropriate topology and materials witch the machine frame was made.
133

Konstrukční návrh lineární osy pro těžký obráběcí stroj / Design of linear axis for heavy machine tool

Horák, Miroslav January 2019 (has links)
This diploma thesis deals with the design of linear axis for heavy machine tool. The thesis describes the definition of heavy machine tool and its basic construction nodes. The next chapter describes the components of the linear feed assemblages, the basic principles of use and their advantages and disadvantages. On the basis of this research part there are selected variants of the solution and in the last part of the thesis there is a design of the axis X of the gantry machine tool. Part of the work is a 3D model of the proposed feed assemblages and part of the drawing documentation.
134

Návrh digitálního dvojčete CNC obráběcího stroje / Design of digital twinn of CNC machine tool

Staněk, Václav January 2019 (has links)
The Master’s thesis deals with design of digital twins of machine tools and application of designed procedure on a case study – digital twin of the machine tool MCV 754 Quick. In the first part are described current roles of digital twins in the field of machine tools and also hardware and software options for creating them. Software and hardware tools by Siemens (Mechatronics Concept Designer and SIMIT) are used for the case study. The complex procedure of creating the digital twin is designed in the second part, starting with preparation of a model, ending with the virtual commissioning of the machine tool MCV 754 Quick. The procedure is described in detail, including preparation of 3D model of the machine tool, assignment of physical properties and joints, preparation of PLC, connection all the elements of the whole system: Sinumerik – SIMIT – Mechatronics Concept Designer and controlling the twin via CNC automation system. Output of the thesis is the virtually commissioned machine tool, capable of being controlled by Sinumerik 840D sl. This is the first step in development of the full-fledged digital twin of machine tool, which can be used for testing the functionality and capability of this new technology in industry.
135

Konstrukční návrh lineární osy pro těžký obráběcí stroj / Design of linear axis for heavy machine tool

Kubálek, Petr January 2020 (has links)
This diploma thesis deals with the design of the linear axis of a heavy machine tool. It describes the basic specifications of these machines, their manufacturers, the parts of which the axis consists and the design itself. The design includes several design variants, calculation of the movement mechanism, drive and linear guide. Follows the selection of the most suitable variant and the drawing documentation of the resulting linear axis.
136

Návrh výrobní technologie součásti obráběcího stroje. / Production technology for part of metal cuting machine.

Kachyňa, Stanislav January 2010 (has links)
This thesis deals with design for manufacturing technology single part on machine FS, which is the connecting part. Work deals with the material of this component, therefore, cast iron with lamellar graphite, the properties of this material, primarily focusing on the machinability. Due to the shape and dimensions of the workpiece is also described problems cutting of box parts, the most common operations used in their manufacture, including cutting tools and materials. These findings are then applied in terms of the company TOS Kuřim - OS a.s. An analysis of current manufacturing technology and design is made for its amendment. In conclusion with the technical-economic evaluation.
137

Innovation durch Konzentration? Schwerpunktbildung und Wettbewerbsfähigkeit im Hochschulwesen der DDR und der Bundesrepublik, 1949-1990: BMBF-Forschungsverbund »Innovationskultur in Deutschland« [Abschlussbericht]

Fraunholz, Uwe, Schramm, Manuel January 2005 (has links)
No description available.
138

Simulationsgestützter Variantenvergleich des Antriebsstranges einer Werkzeugmaschine

Freigang, Tino 02 July 2018 (has links)
Gekoppelte Umlaufrädergetriebe bilden den Antriebsstrang von Orbital- Bearbeitungsmaschinen (OBM). Aufgrund der Variantenzahl einsetzbarer Umlaufrädergetriebekombinationen ist die konstruktive Auslegung dieser Antriebsstränge anspruchsvoll. Der Vortrag liefert unter Verwendung der Mehrkörpersimulation (Software: SIMULATION X) einen Beitrag einer systematischen Herangehensweise zur Ermittlung wesentlicher Eingangsgrößen der komplexen Getriebedimensionierung. Aussagen über wirksame Drehmomente, Drehzahlen, Verzahnungskräfte und Verlagerungen des TCP unter spezieller Betrachtung des dynamischen Systemverhaltens der Antriebsstränge werden getroffen. Variantenrechnungen ermöglichen zudem den Vergleich verschiedener Getriebe- und Maschinenelementkonfigurationen. Vertiefend wird auf die erweiterte Modellierung der Besonderheiten der Getriebearchitektur mit spielbehafteten, gekoppelten Umlaufrädergetriebe und diverser Maschinenelemente, z.B. Hauptspindellagerung oder Wälzschraubtriebe, eingegangen. Maßnahmen der Modellvereinfachung mit dem Ziel reduzierter Rechenzeiten bei erhöhter Modellrobustheit werden dargestellt. Richtlinien der Modellverifikation sowie Konstruktionsvorgaben für den getriebebasierten Nebenantriebsstrang werden abschließend geschlussfolgert.
139

Analyse und Gestaltung der Lebenszykluskosten von Funknetzinfrastrukturen: Entwicklung, Anwendung und Transfer eines Modellierungs- und Managementkonzepts

Lindner, Romy 27 November 2013 (has links)
Der wirtschaftliche Erfolg von Unternehmen der Mobilfunkbranche wird nicht nur durch die zuverlässige Bereitstellung von Diensten und die Entwicklung innovativer Geschäftsmodelle, sondern auch durch die Planung, Errichtung und Unterhaltung qualitativ hochwertiger und kosteneffizienter Funknetzinfrastrukturen bestimmt. Angesichts eines rasanten technischen Fortschritts, der Veränderung von Kundenansprüchen sowie der Komplexität und Langlebigkeit der Funknetze stellt dies eine enorme Herausforderung dar. Vor diesem Hintergrund wird zur Sicherstellung einer langfristigen Wirtschaftlichkeit der Infrastruktur im Rahmen der Arbeit ein aus drei miteinander verzahnten Bausteinen bestehendes Modellierungs- und Managementkonzept zur Analyse und Gestaltung der Lebenszykluskosten von Funknetzinfrastrukturen entwickelt. Den ersten Baustein repräsentieren Entscheidungsmodell(system)e, deren Bildung und Auswertung sich zur Vorbereitung von Investitionsentscheidungen bei komplexen, infrastrukturbezogenen Problemstellungen eignet. Ansätze eines lebenszyklusorientierten Target Costing für die Infrastruktur von Funknetzen als zweiter Baustein tragen zum Aufdecken von Kostensenkungspotenzialen bei und liefern Ansatzpunkte zur marktgerechten Gestaltung der Infrastruktur. Die erfolgreiche Anwendung des Konzepts unterstützen Ansätze bzw. IT-Lösungen zur Bereitstellung zeit- und sachgerechter Informationen (dritter Baustein). Schließlich wird die Anwendbarkeit des Konzepts auf praxisbezogene Fragestellungen demonstriert sowie die Transferierbarkeit der Erkenntnisse auf weitere komplexe technische Systeme, hier Werkzeugmaschinen, geprüft. / The economic success of companies in the mobile communications industry is determined not only by a reliable provision of services and by the development of innovative business models, but also by the planning, construction, operation and maintenance of high quality and cost-effective radio network infrastructures. This represents an enormous challenge in view of rapid technological progress, changes in customer requirements as well as complexity and longevity of radio networks. Against this background and in order to ensure a long-term cost-effectiveness of infrastructure, a modeling and management concept that allows to analyze and to influence the life cycle costs of radio network infrastructures is developed. This concept consists of three interlinked components. (Systems of) Decision models represent the first component. They are suitable for preparing decision-making about investments in view of complex, infrastructure-related (decision) problems. Approaches of a life cycle oriented target costing for radio network infrastructures as the second component make cost reduction potentials accessible and provide starting points for the market-driven design of infrastructure. The successful application of the concept is supported by IT solutions, which provide appropriate information (third component). Finally, the practical use of the concept is demonstrated and it is investigated whether findings are transferable to other complex technical systems – here machine tools.
140

Разработка технических средств уменьшения температурных погрешностей обработки на высокоскоростных токарных станках : магистерская диссертация / Development of technical means to reduce the temperature errors of processing on high-speed lathes

Оссовская, Е. С., Ossovskaya, E. S. January 2021 (has links)
В начале работы рассматриваются факторы, которые влияют на точность станков, и учитывается роль температурных деформаций для обеспечения точности обработки на металлорежущих станках. Наблюдается, что большое влияние на точность станков оказывают тепловые деформации. После этого познакомились со способами уменьшения температурных деформаций узлов станков, которые используются в данное время, и с техническими средствами их реализации. Рассмотрев существующие системы, мы определили задачу разработки системы термостабилизации с водяным охлаждением электрошпинделя. Для начала мы модернизировали существующую систему термостабилизации шпиндельного узла, в которую включили цепь дифференциала. Потом, обозначив достоинства и целесообразность комбинированного управления, разработали более совершенную систему термостабилизации шпиндельного узла. Далее рассмотрен другой фактор погрешности при обработке – это инструмент, в нашем случае резец для токарной обработки. Для него была разработана система охлаждения с учетом нагрева пластины. / At the beginning of the work, the factors that affect the accuracy of machine tools are considered, and the role of temperature deformations is taken into account to ensure the accuracy of processing on metal-cutting machines. It is observed that thermal deformations have a great influence on the accuracy of machine tools. After that, we got acquainted with the ways to reduce the temperature deformations of machine components that are currently used, and with the technical means of their implementation. Having considered the existing systems, we determined the task of developing a thermal stabilization system with a water-cooled electric spindle. To begin with, we upgraded the existing thermal stabilization system of the spindle assembly, which included a differential circuit. Then, having identified the advantages and expediency of combined control, we developed a more advanced system of thermal stabilization of the spindle assembly. Next, another factor of error in processing is considered – this is a tool, in our case, a cutter for turning. A cooling system was developed for it, taking into account the heating of the plate.

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