A microestrutura de uma peça temperada determina suas características mecânicas. Dessa forma, torna-se fundamental conhecer os parâmetros que influenciam na formação da estrutura do componente tratado com função dos tratamentos térmicos aplicados, permitindo obter melhorias de qualidade de uma peça frente a sua aplicação. Métodos distintos podem ser empregados para obtenção da camada de têmpera. Entretanto, esses métodos devem ser parametrizados adequadamente para garantir a qualidade do produto final. No trabalho em questão, aplicaram-se dois metódos distintos de têmpera: por indução e por condução para obtenção da camada martensítica, dureza e durabilidade requerida em cremalheiras de aço SAE 1045, utilizadas em mecanismo de direção automotiva. Fabricou-se um lote de peças, do qual metade das peças foram tratadas por indução e a outra por condução. Após a têmpera e após o revenido, foi avaliado o nível de empenamento, a dureza superficial, a microdureza, a microestrutura formada. A peças após o término do processo de fabricação, foram montadas no sistema caixa de direção, sendo realizados ensaios de durabilidade e impacto dos mesmos. Os tratamentos realizados demonstraram resultados de empenamento, dureza, microestrutura e ensaios de durabilidade e impacto no produto final, dentro das especificações. O processo de têmpera por condução levou a melhor micrestrutura, mais alta dureza e menores níveisde empenamento comparado com o processo de têmpera por indução. Mas, também constatou-se que é possível desenvolver melhorias no processo de indução para atingir-se resultados melhores. / The microstructure of a hardened part is determining its mechanical characteristiscs. Thus, the knowledge of pararameters influencing the heat treated part’s microstructure is of fundamental importance. This allows to obtain quality improvements for specific applications. Diferent methods can be used for the obtation of a hardened layer. However, in these methods the parameters have to be correctly set to reach the final product quality. In this work, two diferente techniques were applied, induction and conduction surface hardening to obtain a required martensitic layer depth, hardness and durability of SAE 1045 steel racks used in automotive driving systems. A batche of parts were manufactured, being half of the parts surface hardened by Induction and half by conduction. After hardening and after tempering, the warpage level, surface hardness, microhardness and microstructure were investigated. The parts were mounted in a steering gear system and then endurance tests and impact tests were carried out. The results of warpage levels, hardness, microstructure and endurance tests, as well as the impact tests were in the range of the specifications. The conduction hardening process leads to better microstructure, higher hardness and lower warpage levels compared to induction hardening. But it was found that the Induction hardening can be optimized to reach better results.

A microestrutura de uma peça temperada determina suas características mecânicas. Dessa forma, torna-se fundamental conhecer os parâmetros que influenciam na formação da estrutura do componente tratado com função dos tratamentos térmicos aplicados, permitindo obter melhorias de qualidade de uma peça frente a sua aplicação. Métodos distintos podem ser empregados para obtenção da camada de têmpera. Entretanto, esses métodos devem ser parametrizados adequadamente para garantir a qualidade do produto final. No trabalho em questão, aplicaram-se dois metódos distintos de têmpera: por indução e por condução para obtenção da camada martensítica, dureza e durabilidade requerida em cremalheiras de aço SAE 1045, utilizadas em mecanismo de direção automotiva. Fabricou-se um lote de peças, do qual metade das peças foram tratadas por indução e a outra por condução. Após a têmpera e após o revenido, foi avaliado o nível de empenamento, a dureza superficial, a microdureza, a microestrutura formada. A peças após o término do processo de fabricação, foram montadas no sistema caixa de direção, sendo realizados ensaios de durabilidade e impacto dos mesmos. Os tratamentos realizados demonstraram resultados de empenamento, dureza, microestrutura e ensaios de durabilidade e impacto no produto final, dentro das especificações. O processo de têmpera por condução levou a melhor micrestrutura, mais alta dureza e menores níveisde empenamento comparado com o processo de têmpera por indução. Mas, também constatou-se que é possível desenvolver melhorias no processo de indução para atingir-se resultados melhores. / The microstructure of a hardened part is determining its mechanical characteristiscs. Thus, the knowledge of pararameters influencing the heat treated part’s microstructure is of fundamental importance. This allows to obtain quality improvements for specific applications. Diferent methods can be used for the obtation of a hardened layer. However, in these methods the parameters have to be correctly set to reach the final product quality. In this work, two diferente techniques were applied, induction and conduction surface hardening to obtain a required martensitic layer depth, hardness and durability of SAE 1045 steel racks used in automotive driving systems. A batche of parts were manufactured, being half of the parts surface hardened by Induction and half by conduction. After hardening and after tempering, the warpage level, surface hardness, microhardness and microstructure were investigated. The parts were mounted in a steering gear system and then endurance tests and impact tests were carried out. The results of warpage levels, hardness, microstructure and endurance tests, as well as the impact tests were in the range of the specifications. The conduction hardening process leads to better microstructure, higher hardness and lower warpage levels compared to induction hardening. But it was found that the Induction hardening can be optimized to reach better results.

The theme of dissertation is "Inheritance and steering gear of inheritance in Czech Republic" because I widen the original theme of procedural law to material law - inheritance, according to New Civil Code (NOZ) which brought to Czech legal order many changes, also in the area of inheritance in Czech legislation. The thesis also analyses the changes which brought Zákon o zvláštních řízeních soudních. Dissertation then compares the new and the old legislation, highlights its pluses and minuses and also resolves if the new legislation is better the the old legislation and where are these changes obvious. This thesis should be general knowledge of changes in area of inheritance and steering gear according to NOZ, not at all detailed processing of institutes of inheritance law. Practical part of the thesis analyses judicature and three concrete testaments.

This report presents the results and findings gathered during the master thesis work performed by Madeleine Jareblom at Scania CV AB in Södertälje. Scania is a developer and manufacturer of trucks and buses. They always strive to improve their testing and simulations for current and future products.  In order to predict the outcome or to analyse the performance of components or systems, simulation models are a powerful tool to use. Realistic and adaptive models are of great interest for Scania and this thesis will cover a steering system performance simulation capability. A steering system consist of a hand wheel, steering gear and linkages down to the steering wheels. The purpose of a steering gear is to ease the resistance a driver has to apply in order to steer the wheels.  There are a lot of different steering systems that are being used in vehicles these days but one of the more common ones is Electric Hydraulic Power Steering (EHPS) which this paper will cover. The simulation model is of an open loop design for an EHPS system that takes input data and divide them into separate calculation blocks. Static variables and data from vehicle measurements were used, together with some assumptions such as; front wheel steering, only applicable for trucks, no roll inclination, 2- or 3-axel vehicles and some static angels in the suspension geometry. During the construction phase of the model, calibrations were performed and there it was found that the friction in the system was load dependent. When the model was calibrated the final output results consisted of; calculated trajectory of the vehicle, the required output torque from the steering gear, input and output power of the steering system together with the consumed energy. From the results of the trajectory output it could be seen that the model is sensitive to small deviations of the handwheel angle and possible road banking. This entailed that the calculated trajectory did not resemble the driven path gathered from vehicle test data. The calculated output torque from the model, was validated with the use of measured pressure and supplier specifications for the steering gear. The results indicated that the calculation model could capture torques from the steering gear close to reality. It could be concluded that the model could be used to describe resulting torques, output and input power together with the consumed energy.

This thesis covers the development of a component specification for the steering system of vehicles engineered by CEVT. This includes the components steering column, intermediate shaft, steering gear and tie rods. Due to the reuse of requirements on the component specification from previous projects it now lacks connection to customer needs. A verification of the component specification is necessary to ensure that no redundant or unnecessary requirements are present. The verification was performed through a comparison between a newly established specification and the current one. Identified customer needs were gathered on complete vehicle level and classified according to customer satisfaction with respect to implementation according to the Kano model. The subjective customer needs were translated into objective, quantifiable metrics on complete vehicle level that was then decomposed onto component level. Customer needs and metrics were then correlated against each other and visualized through the House of Quality matrix. Numeric targets for the metrics were based on its impact on customer satisfaction. This resulted in 50 identified metrics connected to the steering column and 58 metrics connected to the steering gear. The comparison resulted in 22 deviations between the new and current specification where 8 metrics was identified for further investigation. Further development would include investigation of these 8 identified metrics and relate targets to competitors’ performance.

Future heavy duty vehicles will be designed and manufactured with improved Advanced Driver Assistance Systems, ADAS. When developing ADAS, an accurate model of the vehicle dynamics greatly simplifies the development process. One element integral to the vehicle lateral dynamics and development of ADAS is the steering system. This thesis aims to develop an accurate model of a heavy duty vehicle steering system suitable for simulations. The input to the system is an input torque at the steering wheel and the output is the wheel angle. Physical models of the system components are developed using bond graphs and known relations. Some components are modelled with non-linear inefficiencies and friction of different complexity. Unknown parameters and functions are identified from measurement data using system identification tools such as, for example, linear regression and non-linear grid search. The different subsystems are identified separately to the extent deemed possible. Different model designs are considered, validated, and compared. The advantages and disadvantages of different model choices are discussed. Finally, a non-linear state space model is selected for its high accuracy and efficiency. As this final model can be used to simulate a heavy duty vehicle steering system on a desktop computer faster than real time, it fulfills its purpose.

Not available / text

Not available / text

This thesis deals with the design of steering holder for a race car in the category Formula Student using topology optimisation and analysis of this design. The objective of this thesis is gaining knowledge about topology optimisation and application of this knowledge to the design of a replacement of the steering gearbox and its holder.

Thesis with the title "Life stories and professional careers of women headmasters of vocational high schools" deals with professional life of women headmasters of vocational high schools and analyzes this professional life. Per this analysis is detected, what is the benefit of these headmasters for school and if they promote a development of the school. Narrative analysis was used on this research.Beside the research there are answered other questions, which are related to professional life and are associated with the primary research question. There are described the phases of professional life and there are stated the effects, which influence the decision making of the headmasters. In the conclusion of research the headmasters alone evaluate their actions in position of headmaster.The primary research question is answered, how it results from research, all headmasters are benefit for their school. Schools, which were guided by them, had evolved and it is them, who are the reason of its growth. Recommendations for futher research is analysis of professional men headmasters.