National Repository of Grey Literature 110 records found  beginprevious58 - 67nextend  jump to record: Search took 0.01 seconds. 
Design of the feeding mechanism for L profiles
Witos, Anton ; Vlašic, František (referee) ; Mazal, Pavel (advisor)
In this bachelor thesis was designed machine for feeding L profiles and end effector of service robot. Machine uses pneumatic piston to create frictional force between profile and feeding wheels. For movement of profile is used chain transmission which drive feeding wheels. End effector uses for work special type of electromagnet which uses electric voltage only for disabling. Thesis includes review of suggested solutions and choice of optimal solutions.
Optimization of ultrasonic leak detector of pneumatic system
Macků, Ondřej ; Mazal, Pavel (referee) ; Vlašic, František (advisor)
The thesis deals with design and optimization of exchangeable modules for localization of air distributable ultrasound in concept of ultrasound probe design. Several series of these modules were manufactured using the technology of rapid prototyping and tested on artificially created source of air leak. Based on these verification experiments two types covering wide use for identification of pneumatic systems leaks were selected and modified. These two types are long range module for more accurate and expended reach of the leak detection and focusing attachment for narrowing the received range of scanning module and elimination of surrounding ultrasound. Part of the thesis is also analysis of the acoustic signal processed by modern acoustic emission analysers which allow besides standard parameters recording also continuous sampling up to 10 MHz and design solution for attachment of add-on modules to the detector. The thesis is beneficial for raising awareness of leak measurements, prototype manufacturing by using the 3D printing and designing and manufacturing of modules.
Influence of dynamic loading on the contact fatigue characteristics of bearing material
Hložek, Jiří ; Hutař, Pavel (referee) ; Mazal, Pavel (advisor)
This thesis deals with the study of sudden step changes observed in model testing of standard bearing steel 100Cr6. Methodology of experiments with step change of load is proposed and applied in measurements. Three complete series of experiments were conducted, and rating life was determined for each loading trend. Based on the experiments carried out, it was found that the selected steel is able to withstand the sudden step of load changes, despite the fact that it is not material of choise for this type of load. Part of this work was to verify functionality of the innovated test stations AXMAT with modern diagnostics and a new control system, and also of the hydraulic variant of AXMAT, which allows to remotely derive dynamic loading of the test sample.
Design of clamping device for machining of manifold part
Foltýn, Jan ; Mazal, Pavel (referee) ; Svoboda, Petr (advisor)
This thesis deals with clamping fixtures. It aims to design an effective clamping solution for machining parts on a milling machine. The clamping solution was designed and then verified by a series of calculations. The main goal and partial objectives were fulfilled. The output is the design of fixture, which can clamp given part. Subsequently, based on the calculations it was decided to use four of these fixtures on one machining table. When calculating the appropriate variation of the fixture layout, an estimate of the time required for the operations performed by the machine operator was made. The thesis offers an overview of the materials used in the automotive industry. Furthermore, the study of clamps and clamping systems. It also touches the problem of optimizing manufacturing process and demand for ways to speed up the manufacturing process.
Diagnosis of Pneumatic Cylinders Using Acoustic Emission Methods
Mahmoud, Houssam ; Baran,, Ireneusz (referee) ; Santos, Serge Dos (referee) ; Mazal, Pavel (advisor)
Tato práce se zabývá vývojem nového efektivního diagnostického postupu pro kontrolu funkce pneumatických válců pomocí metody akustické emise. Cílem práce bylo navrhnout a určit diagnostická kritéria pro hodnocení kvality vybraných typů pneumatických válců. Prvním krokem bylo nalezení typického akustického emisního signálu, který je spojen s určitým typem poškození ve válci využitím frekvenčního spektra signálu. Později byl tento parametr nahrazen parametrem RMS během sledování změn v průběhu testů. Na konkrétních válcích byl sledován vztah mezi akustickou emisí a různými typy defektů a byl představen nový přístup k určování těchto typů vad a jejich odlišením v signálu akustické emise. Druhý krok studie že neporušené a poškozené válce byly porovnávány tak, aby se zjistily výrazné rozdíly, které určují, zda je válec poškozen nebo nepoškozen. Několik nepoškozených válců bylo testováno akustickou emisí a následně v nich byly vytvořeny umělé vady. Signály z vysouvání a zasouvání pístu byly zaznamenány a analyzovány pomocí řady parametrů. Na základě časového zpoždění a normalizace RMS byly rozpoznány odezvy mezi poškozenými a nepoškozenými pneumatickými válci. Rozdíly byly zjištěny porovnáním maximální hodnoty RMS ze snímače upevněného na předním víku válce a snímače upevněného na zadním víku válce pro jeden cyklus. Poškozené a nepoškozené válce byly rozlišeny pomocí rozdílů energetických hodnot přítomných v signálech z obou snímačů v závislosti na zdvihu pístu. Konečné vyhodnocení válce bylo určeno výpočtem celkové hodnoty RMS. Ve třetím kroku experimentu byly válce postupně zatěžovány různými závažími ve svislém směru. Signály akustické emise byly zaznamenány z vysouvání a zasouvání pístu a poté analyzovány. Časové zpoždění se vypočítává z digitálního vstupu a začátku pohybu pístu. Energie signálu a RMS akustické emise porovnávají různé reakce v poškozených a nepoškozených pneumatických válcích s a bez zatížení. Výsledky testu ukázaly lineární vztah mezi křivkou RMS a zatížením. Defekty ovlivňují vztah mezi aplikovaným zatížením a zaznamenaným signálem snímačů.
Suspended bicycle carrier for buses
Svoboda, Pavel ; Vlašic, František (referee) ; Mazal, Pavel (advisor)
This bachelor´s thesis describes the construction of universal the rack for bicycles to different types of buses. The aim was to produce a simple, lightweight, safe, affordable, accessible design of the rack for bicycles with easy the suspension, but also with the access to the engine compartment of the bus.
Localization and identification of damage type of pneumatic drives
Richter, Vladislav ; Dočkal, Aleš (referee) ; Mazal, Pavel (advisor)
Pneumatic drives are an integral part of many machinery, with high demands on their reliability. Unfortunately, they sometimes fail, either due to improper production or assembly at the factory or by gradual degradation of moving parts and sealing elements during operation. Current diagnostic methods do not allow localization or identification of the type of damage and do not allow the operator to make a qualified decision. This work deals with the use of acoustic emission for these purposes. On PB type cylinders manufactured by Poličské strojírny a.s., a methodology is introduced which leads to the direct identification or at least localization of selected defects. By implementing this methodology in the final inspection of the production plant, the percentage of exposed pieces of waste will be increased, thus preventing accidents of these faulty pieces during operation.
Draft production line for light transmitting LiCrete blocks
Caletka, Tomáš ; Čížek, Petr (referee) ; Mazal, Pavel (advisor)
The aim of this thesis is to design a production line for manufacturing of light transmitting bricks LiCrete. This brick is a special interior design component which is made of concrete and light transmitting parts. It’s manufactured by casting into the dismountable molds. The research part explains manufacturing technology and possibilities to build production line. The concept solution part is about two concepts of production line and about a few ways how to integrate vibration machine into the line. Main part of the thesis describes mechanical design solution with focus on manipulators and vibration part. Last part of the thesis is about design of automation integration into the production line.
Eddy Current Probe Design and its Application on Aircraft Composite Structures
Boháčová, Marie ; Hájek, Karel (referee) ; Kopec, Bernard (referee) ; Mazal, Pavel (advisor)
This thesis deals with design of an eddy current transducer which enables non-destructive inspection of composite aircraft structures primarily carbon fiber reinforced plastic (CFRP) in areas of manufacture and maintenance. The design of the transducer is based on analytical-experimental approach and its electrical and mechanical parameters were optimized to ensure a good signal to noise ratio at the six composite samples. These samples contain artificial discontinuities in the form of various types of defects. These defects are simulating the various types of damage created in the aircraft structure, especially delamination or thickness changes of composite materials. The experimental measurements, data collection and non-destructive evaluation were performed during the period. The result of this work is functional eddy current probe, which is reliably able to detect some damage of the carbon composite structures to the depth of 3,9 mm.
Eddy Current Probe Design and its Application on Aircraft Composite Structures
Boháčová, Marie ; Mazal, Pavel (advisor)
This thesis deals with design of an eddy current transducer which enables non-destructive inspection of composite aircraft structures primarily carbon fiber reinforced plastic (CFRP) in areas of manufacture and maintenance. The design of the transducer is based on analytical-experimental approach and its electrical and mechanical parameters were optimized to ensure a good signal to noise ratio at the six composite samples. These samples contain artificial discontinuities in the form of various types of defects. These defects are simulating the various types of damage created in the aircraft structure, especially delamination or thickness changes of composite materials. The experimental measurements, data collection and non-destructive evaluation were performed during the period. The result of this work is functional eddy current probe, which is reliably able to detect some damage of the carbon composite structures to the depth of 3,9 mm.

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