The Masters thesis is focused on surface integrity at reaming with high productive reaming head MT3 made by HAM-FINAL. Theoretical part of thesis aims at analyse of the most frequently evalueted surface integrity parametrs and its possible influence on functional performance of machined components. Next theoretical parts are aimed at reaming process, reaming tools characteristics, detailed reaming head MT3 characteristics and its aplication in company Sauer Danfoss. The aim of experimetal part of thesis is surface integrity of holes reamed MT3 during its tool life evalation.

This thesis focuses on comparison of cermet cutting materials, which are used to manufacture reamer cutting edges. It contains review of current market reamer tools and suppliers of cermet semi-finished products. Cermet cutting tips were used to machine parts from carbon steel and analysis was made to compare wearing of the tools from different suppliers. This test was conducted on turning machine in working conditions typical for reaming. During this test there were taken notes on the wear of the tools and surface roughness of the part. The output of this is work is data processing, which indicates durability of each tested cermet.

The aim of this thesis is to design, implement and evaluate an experiment that verifies the influence the size effect on selected parameters of the surface integrity. For the experiment were used highly productive reaming head MT3 made by HAM-FINAL. Evaluation of the surface integrity was done in terms of the characteristics of the surface roughness, geometric tolerances and changes in microstructure. Furthermore, the influence of the depth of chips evaluated for changes in the feed force, cutting torque and changes in specific cutting energy. The theoretical part deals with the description of the size effect, characteristic reaming, surface integrity, preparation of material and identification of highly productive MT3 reaming head.

This dissertation thesis focuses on the evaluation of modern machine tools, especially tools for finishing operations, with which the effect of the passive force components on the machining process is evaluated. The thesis will examine the analysis of creating chips and circumstances that accompany this process and substantially involve the formation of a new surface. The analysis of the process of the recording of the power load of the MT3 tool takes place in the experimental part of the thesis. MT3 is a reaming head intended for finishing holes at high cutting speeds (100-200 m.min-1) with removal of small cross section AD (0.024 mm2) chips. Particular attention is paid to the newly created profile from the surface after machining and evaluation of changes in geometry and loading of the cutting edge, which is significantly reflected in the establishment and the development of passive forces.

This dissertation thesis focuses on the evaluation of modern machine tools, especially tools for finishing operations, with which the effect of the passive force components on the machining process is evaluated. The thesis will examine the analysis of creating chips and circumstances that accompany this process and substantially involve the formation of a new surface. The analysis of the process of the recording of the power load of the MT3 tool takes place in the experimental part of the thesis. MT3 is a reaming head intended for finishing holes at high cutting speeds (100-200 m.min-1) with removal of small cross section AD (0.024 mm2) chips. Particular attention is paid to the newly created profile from the surface after machining and evaluation of changes in geometry and loading of the cutting edge, which is significantly reflected in the establishment and the development of passive forces.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In many applications of metalworking industry it is required mass production of parts containing holes with finish and tolerances typically from precision assembling, with working quality, ISO IT grade, ranging from IT7- IT5. But to produce these holes with tighter tolerances and with low geometrical errors, conventional twist drills may be not enough, so further processes are required, like reaming for example. Before any reaming process comes the drilling process, resulting in two different tools, two parts on necessary machining time, which in turn affects productivity and competitiveness. Therefore , any investment in the production of tools and techniques to reduce the machining time of close tolerance holes without affecting the integrity of the surface and preferably at a lower cost , will receive special attention from the machining community. In this context, this paper presents a technical and economic study of the use of special designed drill in replacement by a reamer the production of cylindrical holes of 10 mm diameter pieces of compacted graphite cast iron in terms of finish, roundness and dimensional deviation. It was also investigated the influence of the allowance in the final quality of the machined hole reamer. The surface of the holes and the microhardness of the machined holes were also analyzed and the tool wear was monitored. Finally, the economic analysis of the tools employed was performed. The results showed that special drill resulted in finish and dimensional deviation as good as those produced by the reamer. IT6 was the working quality obtained after reaming with reaming allowance of 0.5mm, while IT8 quality was obtained by using the special designed drill. Wear on special drill was lower than that observed in the reamer, and for the latter chipping occurred. Up to 29% of reduction in machining time was achieved by using the special drill, which resulted in a reduction of 33% cost as well. In contrast the values of cylindricity deviations were higher than those obtained with the reamers under the conditions investigated. The hardness was not affected by the processes employed. / Em muitas aplicações da indústria metal-mecânica exige-se a fabricação de peças com furos que apresentem acabamento e exatidão geométrica necessária para a montagem de precisão, normalmente com qualidade de trabalho variando entre ISO IT5-IT7. Mas para a produção destes furos de tolerâncias mais estreitas e com menores erros geométricos, as brocas helicoidais convencionais não são suficientes, de forma que são necessários processos subsequentes, como o alargamento, por exemplo. Antes de qualquer operação de alargamento vem à operação de furação, chamada de pré-furação, e assim para um furo alargado são necessárias no mínimo duas ferramentas diferentes, duas parcelas no tempo de usinagem, que por sua vez afeta a produtividade e competitividade. Portanto, qualquer investimento na produção de ferramentas e técnicas que permitam reduzir o tempo de usinagem de furos de tolerância estreita, sem afetar a integridade da superfície e de preferência com menor custo, receberá especial atenção da comunidade de usinagem. Neste contexto, este trabalho apresenta um estudo técnico e econômico do emprego de broca especial em substituição ao alargador, na produção de furos cilíndricos, de 10 mm de diâmetro, em peças de ferro fundido vermicular, em termos de acabamento, cilindricidade e desvio dimensional. Investigou-se também a influência do sobremetal na qualidade final do furo usinado pelo alargador. As paredes dos furos e a microdureza dos furos usinados foram também analisados e o desgaste das ferramentas foi monitorado. Por último, foi realizada a análise econômica das ferramentas empregadas. Os resultados mostraram que a broca especial resultou em acabamento e desvio dimensionais tão bons quanto aqueles produzidos pelo alargador. IT6 foi á qualidade obtida pelo alargador após furação com sobremetal de 0,5 mm, enquanto que a broca especial produziu qualidade IT8. O desgaste da broca especial foi menor que aquele dos alargadores, sendo que para estes últimos ocorreu lascamento. Cerca de 29% de redução no tempo de usinagem foram obtidos com á broca especial, o que resultou em um custo de produção 33% menor. Em contrapartida os valores dos desvios de cilindricidade foram superiores aqueles obtidos com os alargadores nas condições investigadas. A microdureza não foi afetada pelos processos empregados. / Mestre em Engenharia Mecânica

The diploma work deals with the evaluation of force load procedure problems when using reaming head MT3 depending on selected criteria of surface integrity of machined hole. It is possible to eliminate some unwanted elements when reaming by force load procedure analysis. These negative elements can influence both the tool e.g. its previous wear and the defect of a newly made hole.

Le centre d'usinage est un moyen de production onéreux. Son impact direct sur la qualité des pièces produites, rend de son audit une opération délicate et complexe.L'objectif des travaux s'intègre dans cette démarche globale.Il consiste à concevoir, pour des cas industriels, des méthodes et des outils de caractérisation statique, et dynamique des moyens d'usinage.Il s'agit de savoir caractériser de manière indépendante le comportement dynamiquede la machine et de l'outil afin de juger son aptitude à accomplir des usinages conformes. Dans la démarche qui sera présentée dans ce mémoire de thèse, les développements ont été orientés sur le comportement dynamique du système usinant Couple : Broche/Outil. / Machining centers are very costly. They have a direct impact on the produced parts quality. This fact makes of its audit a comlexe and important operation.The aim of this work is to develop, for industrial cases, methods for the static and the dynamic qualification of machining centers.It is proposed to apply a methodologies in order to evaluate the ability of different machining systems (Spindle/Tool) to run a machining operation in a stable way. The proposed methodologies are based on an experimental measurement of the dynamic behavior for the system including the spindle and the tool holder. Then, by coupling frequencies response functions, a new system (Spindle/Tool) FRF is predicted at the tool tip. Finally, the critical depth of cut is analytically calculated from the eigenvalues of the characteristic equation of the dynamic machining process.

V důsledku enviromentálních aspektů se zavádí obrábění za sucha nebo obrábění s minimem mazání. Převážně se jedná o mazání s průtokem cca 50 ml/h. Tato technologie se úspěšně zavedla pro soustružení, frézování, ale je málo probádána pro vrtání a vystružování. Právě tématu vystružování s použitím minmálního množství mazání je věnována tato diplomová práce.

The diploma thesis deals with the design of the hole-making technology for hydraulic components that are specific for its high requirements on size and shape accuracy. The aim of diploma thesis is to compare the productivity, efficiency and accuracy of reaming with two different reamers – the solid carbide reamer and the newly designed reamer that combines two cermets on cutting part of the tool. In the practical part, the data analyses and calculations were made. It was discovered that the newly designed tool brings economic benefits while the qualities of final hole are improving or remaining at the same level.