Advanced Materials Research Vol. 769

Abstract: Due to rapid developments within the family of rare-earth materials innovative electrical machines can nowadays be used as high efficient generators in various power, as well as rugged constructed machines for automobile battery based propulsion in hybrid and full electric vehicles. The production of different motor concepts spread into different design variants and creates complex variations especially regarding the rotor. Deriving from various research projects, the handling of the permanent magnet components is investigated, including the development of new assembly and fixation methods.

Abstract: The social and technical trends regarding electro mobility and the turnaround in energy policy cause an increasing demand on large-scale and high-quality lithium-ion cells as core components for electrical storage systems. Within the production of lithium-ion cells, cell assembly has to deal with diverse challenges which result from product complexity and a lack of production experience. This paper covers the design of assembly systems for large-scale lithium-ion cells and presents the enhancement of conventional design processes by three add-on modules. The first one is an analysis of product structure and design focus points and is described in this paper. The modules two and three are outlined.

Abstract: Commonly, a modelling and simulation approach is used for parameter optimization and system behavior analysis of assembly system components. However, such simulation approaches are often not well integrated or its analysis is still based on a specific physical domain. This paper proposes an integrated simulation approach that can be used for designing, analyzing and optimizing the entire physical domain as well as the control system of mechatronic components in an assembly system. The state-of-the-art, requirements, our concept and the limitations of an integrated simulation approach are explained in this paper. A case study of the development of conveyor systems using the multi-domain simulation tool OpenModelica is also presented. On-going research shows that the integrated approach offers various benefits such as reduced development time and minimized errors, as well as maintenance during the commissioning process.

Abstract: Abstract. The technical parameters of magnetic actuators, such as electromagnets, resonance actuators, reluctance actuators etc., are determined by the magnetic properties of the materials as well as the manufacturing and the design configuration. Some exemplary defects in electromagnetic actuators due to the manufacturing are heterogeneous magnetic properties of the materials, cracks, defects and parasitic air gaps in and directly around the magnetic circuit. To implement inline measurement systems to characterise defects within the manufacturing process a study has been carried out to display the influences of production impacts on magnetic stray fields outside the magnetic circuit.

Abstract: The individualisation of customer requirements and the increasing pressure to reduce manufacturing costs due to the internationalisation of markets requires undertakings to react flexibly and to ensure long-term competitiveness through innovations in production processes. As far as lowering manufacturing costs is concerned, there is considerable potential for rationalisation in assembly work. At the same time, it is expected that the provision and supply of parts in automated assembly systems will become a bottleneck in future with regard to quality, time and costs. The reason for this is that the part feeding systems traditionally used are stretched to their limits in terms of supply performance, flexibility and process reliability. Orienting parts in feeding systems is often the most technically demanding process. Active, aerodynamic orientation systems for feeding parts have been developed at the Institute of Production Systems and Logistics. The system’s parameters have had to be configured manually by experienced technicians to date. This work takes up a great deal of time. In order to minimise this time spent by users, a genetic algorithm (GA) is developed in this paper, which enables the optimum parameter values for unknown parts to be identified automatically. To this end, the optimisation problem to be solved, namely to identify the parameter values for aerodynamic orientation, is first described mathematically. The structure of the GA and its method of functioning are then explained. A methodology to accelerate the convergence speed of the GA is presented in this context, in that the quantity of individuals in each generation and the number of test parts observed is adapted to the quality of the solution in order to shorten the time needed to find the solution.

Abstract: Driven by the demand for green mobility alternatives and the claim to reduce the carbon footprint, technologies for electric mobility are on the advance. Although the idea of using electricity as drive energy came up more than 150 years ago, a considerable potential of development still remains. The automotive industry is in the midst of a time of transition, in which business may change fundamentally in order to meet the upcoming conditions.

Abstract: With the ever-growing demand for micro products, the influence of micro-features and the functional performance of component surfaces represent a high economical potential. A competitive process for the manufacture of micro products is using micro end mills and a desktop milling machine. Since the topography of machined surfaces affects e.g. the wetting interaction or the bacterial cell adhesion, all relevant finishing steps such as the generation of a plane surface parallel to the machining table and the structuring with micro end mills have to be concerned in order to create functional surfaces. In this paper the generation of plane surfaces and chosen tool paths is described first and then the use of ultra-small micro end mills for slot milling in cp-titanium and the influence of process parameters on bottom surface quality is discussed.

Abstract: Metal working fluids (MWF) are widely used in grinding processes to lubricate and to remove the heat and chips from the contact zone. Apart from the chips, abrasive particles from the worn grinding wheel contaminate the metalworking fluid. The solid contaminants, in particular the abrasive particles crumbled from the grinding wheel, are believed to cause several negative effects like for example damaging the guideways of the machine tool. Furthermore, it is assumed that a pronounced interaction of the solid particles and the machined surface will decrease the achievable surface quality of the ground surfaces. Cleaning units are employed within the fluid circuit to prevent failure of the machine tool and to ensure the desired surface quality. The economic efficiency of such cleaning plants cleaning plants depends strongly on the choice of the grade of filtration (the particle size which has to be retained). A grade of filtration which exceeds the actual needs of the machining process adds unnecessary costs for operating the cleaning unit. To enable cost efficient design of filtration units the interaction between solid contaminants and the machining process has to be understood. The results of grinding experiments (face grinding of workpieces made of AISI 52100) confirm a significant increase of the surface waviness when corundum particles are added to the MWF. The underlying effect is an extraordinary tool wear combined with a locally varying effective depth of cut. The excess particles block the pores of the grinding wheel and are transported into the grinding gap. An increasing ratio of the size of solid contaminants and the size of the bonded grains on the wheel accelerates the wear of the tool.

Abstract: The demand for highly resistant surfaces is driven by the requirement for resource efficiency and rising environmental concerns. Finishing processes like long-stroke honing for the machining of boreholes of chuck components make it possible to create surfaces with favourable tribological properties. Since variations of process parameter values have complex effects on the resulting workpiece topography and its characteristic values, many experiments might be necessary to achieve certain properties. To avoid this, a simulation-based approach has been developed that relies on a high resolution model of the tool and the workpiece. For its calibration and validation, systematic investigations of a honing process and the machining parameter values have been conducted, and the measured surfaces are compared to the computed workpiece topographies.