The consideration of energy-related parameters is already in the planning phase an important step towards an energy-autonomous factory. Using Virtual Reality (VR) gives planners an important basis for decision-making ...
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The consideration of energy-related parameters is already in the planning phase an important step towards an energy-autonomous factory. Using Virtual Reality (VR) gives planners an important basis for decision-making with regards to drafting the layout. This potential should also be used for incorporating energy-related parameters. This paper introduces the coupling of a 2D planning system with a VR environment as the basis for the development of an energy-sensitive planning system. A prerequisite for considering energy-related parameters is recording and visualizing them. Therefore, the second part of the paper deals with energy visualization within a machine at the micro level.
In the present paper the influence of a higher setting velocity in the joining process of self piercing solid‐rivets is shown. In the conventional process tool velocities well below 1 m/s are common. The present rese...
In the present paper the influence of a higher setting velocity in the joining process of self piercing solid‐rivets is shown. In the conventional process tool velocities well below 1 m/s are common. The present research results show the potential of increasing them in the range of about 5 m/s. The results are especially relevant for joining high‐strength steels. These steel sheets often cause problems in the process of riveting mixed materials, e. g. aluminium‐steel compound. The high strength of the steel sometimes leads to undesirable material flow in the joining process or unwanted burr development. These effects, which are described in detail in the article, can be reduced significantly for the investigated cases by the use of higher tool velocities. Using a high speed camera and a load cell, a test setup based on a drop tower was realized. It was used to time the force signals and the motion profile of the high speed riveting process. The results of the force analysis show an oscillating force progression. Within a numerical research the principal effects influencing the results of the riveting process can be shown. It was found that the pulse‐like force transmission between riveting machine and punch, results in various vibrations especially of long and thin tool parts. Hence the rivet penetrates the sheet metal with non‐uniform velocities. As a result the early indentation of die into the lower sheet metal at the beginning of the process is reduced, so that the final process step provides a sufficient material flow into the circular rivet groove. A strain‐rate dependent process model with elastic tool properties and consideration of inertia effects is presented.
The research of energy storage systems in the DC link of a machine tool is focused on the choice of the appropriate type of the energy storage system (passive or active) and its control strategy considering better ene...
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ISBN:
(纸本)9781612841670
The research of energy storage systems in the DC link of a machine tool is focused on the choice of the appropriate type of the energy storage system (passive or active) and its control strategy considering better energy efficiency. For the control strategy of the DC/DC converter two ways were taken into account: the proportional-integral and predictive control strategies. The energy consumption model of the drive group was developed in Matlab/SimPowerSystems for quantitative comparisons of the proposed energy storage systems. The model was validated by measurements of energy consumption in the drive unit of a machining centre.
The fabrication of high aspect ratio microstructures is very challenging, especially when the work piece material is hard to machine. Electro Discharge Machining (EDM) offers a contact- and nearly force free way of mi...
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ISBN:
(纸本)9780955308291
The fabrication of high aspect ratio microstructures is very challenging, especially when the work piece material is hard to machine. Electro Discharge Machining (EDM) offers a contact- and nearly force free way of micromachining and is therefore an appropriate means to producing microstructures. One key obstacle for a precise machining by micro-EDM is the tool wear. When ED-machining microstructures process speed, stability and thus tool wear are related to the aspect ratio of the structures. In this study, tool wear ratio within different stages of the EDM process is analysed when machining high aspect ratio micro bores in steel. Experiments with bores of different depths show the correlation between the stage of the process and the flushing conditions on the one hand and the tool wear ratio on the other hand. Thus, it is possible to find and apply optimized parameters for the different process stages. A better understanding of the tool wear will help to minimize it, reducing the cost of the tools and enhancing the precision of the process. This also shall allow an enhancement of the process speed because the need for flushing material out of the bore is reduced by the amount of tool material that can be saved.
This paper deals with the combination of micro milling and laser micro structuring for processing hot embossing dies for microfluidic applications. This strategy permits the advantages of each process technology to be...
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This paper deals with the combination of micro milling and laser micro structuring for processing hot embossing dies for microfluidic applications. This strategy permits the advantages of each process technology to be exploited in order to achieve a cost and time efficient process and also to process forms and structures which cannot be manufactured with the single processes micro milling and laser micro structuring. Basic requirements are a high-precision positioning of the single process areas and also a good machining of the parts and structures with the manufacturing processes micro milling and laser micro structuring. The intersections between the different processing areas present a challenge for this process technology.
Simulation, design optimization and controller design of modern machinetools heavily rely on adequat numerical models. In order to achieve results in shorter computation times, reduced order models (ROMs) are applied...
Current research activities in the field of manufacturing technology design increasingly focus on integrated approaches for process performance enhancements. As in many process development activities, systematic desig...
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Problems in using shape memory alloys (SMA) in industrial applications are often caused by the fragmentary knowledge of the complex activation behavior. To solve this problem, fraunhofer IWU developed a Matlab(R)-base...
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ISBN:
(纸本)9780819480606
Problems in using shape memory alloys (SMA) in industrial applications are often caused by the fragmentary knowledge of the complex activation behavior. To solve this problem, fraunhofer IWU developed a Matlab(R)-based simulation tool to emulate the properties of a SMA wire based on the energy balance. The contained terms result of the characteristic material behavior combined with thermal, electrical, and mechanical conditions. Model validation is performed by laboratory tests. It is shown that there is almost no difference between the measured and the simulated actuator movement. Due to the good quality of the model it is possible to use it in a control loop. Knowing current and voltage enables the computation of the electrical resistance of the actuator and can therefore be used for feedback control. Implementation of the results into industrial applications is exemplified by integration of an actuator in a flap as used in air condition systems of cars. Furthermore, the SMA-based drive will be compared to an electromechanical drive.
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