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Welding the frame of the tandem bicycle
Rajm, Vojtěch ; Sigmund, Marian (referee) ; Kubíček, Jaroslav (advisor)
In the first part of thesis were compared frames of two different bicycles and according to this comparison was designed a geometry of tandem bicycle. In a next part were described the most common materials in cycling industry and theirs advantages and disadvantages. According to the comparison, the steel EN 25CrMo was considered as the most suitable material for its low prize and high strength. After that is described weldability of steels and types of cracks which are one of the most casual defects in welded materials. In another part of thesis are theoretically described kinds of suitable welding methods for bicycle frames. As the most suitable are methods in shielding gases MIG/MAG and TIG. As the best method was chose TIG welding. In a practical part of thesis are compared these methods experimentally. Tubes from selected material were welded by MAG and TIG. The TIG welding proved again as better because of deeper and tough welds.
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Influence of welding direction on depth of penetration for MAG method
Šmak, Radim ; Mrňa, Libor (referee) ; Kubíček, Jaroslav (advisor)
This bachelor thesis deals about Influence of welding direction on depth of penetration in S 235 JR steel for MAG welding. First theoretical part of the thesis was devoted to a description and technology of the chosen method. In the second practical patr of the thesis was designed optimal welding parameters and conditions of welding. Based on them was performed an experiment. From the experiment was detected the depth penetration, heat affected zone and structure of the metal.
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Optimalization of the welding process for low - pressure tubular sets
Urbánek, Štěpán ; Kubíček, Jaroslav (referee) ; Sigmund, Marian (advisor)
The diploma thesis examines the implementation of the production process of low-pressure pipe sets for hydraulic aggregates in the company Bosch Rexroth. The first part presents a literature analysis of used technologies and basic welded materials. The second part focuses on selected subprocesses ensuring the production and proposals for their streamlining. It includes a summary of responsibilities across departments and a template for processing the necessary technical documentation for the smooth running of production. Another proposal includes a technological procedure for practical verification of the production, which simultaneously serves as a basis for measuring the welding time. The reason for the implementation of this production was the extended delivery time of pipe sets from suppliers and possible financial savings. The practical part is concluded with a technical and economical evaluation, which expresses the possible financial savings in the production of low-pressure pipelines instead of the current state involving the cooperation with suppliers.
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Design of paint systems in coachwork parts of easel issues
Fajfr, Jan ; Žák, Ladislav (referee) ; Kubíček, Jaroslav (advisor)
This bachelor thesis deals with proposal for a new type of painting. There is a solution of proper pretreatment for undercoat. Teoretical part includes analysis of these pretreatments, types of powder coatings, options how to apply these coatings including curing. There have been made samples for the purpose of this work and the samples were tested for resistance. Conslusion of this work contains results of the experiment and the choice of the best type of painting with regards of economy.
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Welding of steel C45
Hála, Kamil ; Sigmund, Marian (referee) ; Kubíček, Jaroslav (advisor)
The aim of this bachelor‘s thesis is to propose a suitable welding parameters for a small part of steel C45. This steel contains a high percentage of carbon and therefore is difficult to weld. Gas shielded arc welding techniques were considered to be used, and from such techniques, the TIG method seems to be the most advantageous one. For this technique were suggested three groups of parameters and the most suitable one was chosen to be used for the production. The option chosen is of a welding power I=40 A and with preheating 200 °C. The component is made in the single-part production in SAAB Czech s.r.o.
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Repair of surface sliding
Teplý, Miroslav ; Vyplašil, Evžen (referee) ; Kubíček, Jaroslav (advisor)
The selection of suitable materials for the renovation of sliding shafts requires a comparison of several criteria. The main criteria were selected size shear strength under tensile stress lap bonded assemblies, resistance to adhesive wear and economic criteria. From the results of all tests is selected the most suitable friction material to repair worn out places of shaft. The technological process of sealing the shaft was drawn up on the basis of the literature, recommendations supplier of sliding materials and their own experience.
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Comparison of hand and orbital welding by TIG method
Dušek, Vojtěch ; Hála, Michal (referee) ; Kubíček, Jaroslav (advisor)
DUŠEK VOJTĚCH: Comparison of hand and orbital welding by TIG method This bachelor thesis presents a comparison of manual and orbital TIG welding. It describes the advantages and disadvantages of manual and orbital TIG welding. Mechanical properties, surface structure and heat input on the weld samples were experimentally compared. Thesis also includes technical-economic comparison of these two methods of welding.
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Study of the influence of process parameters on welding properties of ferritic stainless steel in laser oscillation welding
Křepela, Petr ; Kubíček, Jaroslav (referee) ; Mrňa, Libor (advisor)
The aim of this work was to carry out an experiment to assess the influence of the individual welding parameters in the laser welding method with the beam wobbling on the made weld, respectively. welds. The material which was welded was ferritic stainless steel with the designation 1.4016, which, like all ferritic steels, is susceptible to coarse grains and the resulting brittleness which leads to degradation of the mechanical properties of the weld. The welds were compared to a sample welded without wobbling an between themselves. Unfortunately, however, the evaluation of the test samples did not bring significant differences from laser welding without wobbling, however some changes are evident, such as grain orientation, weld defects, or uniformity of mechanical properties over the weld length, where wobbling frequency is most important. Further research should focus on limiting the porosity at higher wobbling frequencies in the shape of a circle or ellipse.
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Welding of heat resisting steels by SMAW
Žemlová, Markéta ; Kubíček, Jaroslav (referee) ; Daněk, Ladislav (advisor)
The bachelor thesis deals with heat resistant steels. Then analyzes the method of automatic submerged arc welding and thermal impacts during welding. In the practical part solves weld overlay of steel 26NiCrMo14 - 5, which is welded with preheating arc under flux OP 121 TTW wire TOPCORE 745 B. Then the weld deposit compared with no preheating weld.
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Influence of shape of the electrode to weld pool
Hrádek, Jan ; Vaněk, Mojmír (referee) ; Kubíček, Jaroslav (advisor)
The project is focused on welding of TIG method. In this method is used non-melting tungsten electrode, which can have different top angles. In different literature there are different opinions about how angle influence weld pool. It was sharpen six different angles of electrode with whom was done welds on carbon steel S235JR and on austenitic corrosion resistant steel x5CrNi1810. The evaluation was done with help of chart where on the axis x is angle of electrode and on axis y are depth and width weld in millimiters. The result of this project was the prove of opinion that with more sharper angle of electrode is depth of weld smaller and width bigger.
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