Data integration between different life cycle stages of a production system is a crucial requirement for the realization of continuous computer support what is often referred to as the Digital Factory. This paper pres...
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Data integration between different life cycle stages of a production system is a crucial requirement for the realization of continuous computer support what is often referred to as the Digital Factory. This paper presents an approach that leverages planning data within the operation phase of a production system by applying Semantic Web technologies and linked data concepts.
The main goal in manufacturing is to minimize production time, cost, energy and resources while maintaining or even improving performance. The main influence on process efficiency in metal cutting can be related to th...
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The main goal in manufacturing is to minimize production time, cost, energy and resources while maintaining or even improving performance. The main influence on process efficiency in metal cutting can be related to the machining parameters, while performance also depends on the material behavior such as strain rate, machining temperature and cutting forces. In the past, industry was searching for higher efficiency mainly by using higher production rates, achieved with higher cutting conditions. However, during the last decade the production process chain has been controlled more and more by the near-net-shape of semi-finished components and the use of high performance processes. This paper presents established and new applications of process modifications, substitutions, optimizations as well as the use of hybrid processes. In high performance cutting (HPC) additional elements play an important role, for example tool design and tool material, wear and tool life, coolant strategies, including dry cutting, MQL, cryogenic and high pressure flushing as well as the machine tool properties. Furthermore, this paper presents and discusses examples of the influence of process parameters in turning, milling, drilling, grinding and impact cutting under HPC conditions on the energy and resources efficiency in the automotive, aerospace, dies and moulds, micromachining and heavy duty industries.
machine tool performance, production accuracy and energy efficiency are interdependent design criteria. To solve this design conflict, bionics – this means technical interpretation of long-term optimized biological p...
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machine tool performance, production accuracy and energy efficiency are interdependent design criteria. To solve this design conflict, bionics – this means technical interpretation of long-term optimized biological principles – could be an effective way to accelerate innovation loops in modern machine tool development processes. In the paper, these aspects will be discussed, and selected solutions will be presented in detail.
According to an international status report, up to 70% of the errors in cutting production can be traced back to time- and process- dependant temperature fluctuations. In particular, thermal effects from processing le...
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According to an international status report, up to 70% of the errors in cutting production can be traced back to time- and process- dependant temperature fluctuations. In particular, thermal effects from processing lead to the deformation of machine components. This affects the tool and the workpiece. This paper considers the research into interactions between process-related and thermal deformations with a focus on the high-precision machining of large workpieces. Previously conducted investigations have demon- strated the effects of the heat flow into the structures of workpieces during the machining process. As one might expect, deforma- tion occurs, which leads to deviations in shape and position. In the same way, length changes due to process-heat transfer can be observed on the tool side. This leads to displacements of the centre point of the tool, which are dependent on the tool geometry and process parameters. However, resulting production errors can often be reduced by improved process control. Considering an exam- ple from the field of mould construction, this problem has been discussed from a practical perspective. Starting with experimental analyses, the heat flow into the workpiece related to the inherent deformation was measured. This was realised using thermographic systems and displacement sensors. Relevant parameters that have a significant influence on the process were to be identified in these tests. Heat-transfer effects were analysed while varying these parameters. In the same way, this should provide support for simulative analyses and facilitate the verification of these analyses. Using computer models, it was possible to detect and evaluate thermoelastic displacements before the processing. Based on this, the findings led to appropriate countermeasures, such as the use of a modified machining sequence. The aim of all of these investigations is the development of optimal machining strategies t o help reduce manufacturing errors.
Ultrasonic vibration has been found very beneficial for the micro electro discharge machining (μEDM) of deep microstructures with high aspect ratios. In this study, the discharge properties of μEDM aided with direct...
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ISBN:
(纸本)9780956679000
Ultrasonic vibration has been found very beneficial for the micro electro discharge machining (μEDM) of deep microstructures with high aspect ratios. In this study, the discharge properties of μEDM aided with direct ultrasonic workpiece vibration are analysed and compared to conventional μEDM machining. It can be shown that not only the number of discharges per second is significantly improved, but also the typical height of the discharge current is differently distributed. The investigation shows that the amount of open circuit states in μEDM can be noticeably reduced by using ultrasonic vibration assistance.
Today highly complex components are manufactured on NC-controlled machinetools. The NC programs, controlling these machines, are usually automatically generated by CAM software. This automatic processing is often err...
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Today highly complex components are manufactured on NC-controlled machinetools. The NC programs, controlling these machines, are usually automatically generated by CAM software. This automatic processing is often erroneous. The VR-based realistic machine simulation, presented in this paper, extends the usual content of a machine simulation, like material removal and collision detection, by various new aspects. The coupling of a real NC unit allows the recognition and elimination of all process- as well as controller-caused errors. The integration of the multi-body simulation enables the consideration of inertia, machine rigidity and milling cutter deflection.
One way to improve the energy efficiency in manufacturing is the use of energy-sensitive methods in production planning. So far, the energy consumption behavior of production facilities has not been investigated in gr...
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ISBN:
(纸本)9781467347792
One way to improve the energy efficiency in manufacturing is the use of energy-sensitive methods in production planning. So far, the energy consumption behavior of production facilities has not been investigated in great detail. Estimates are typically obtained by connected wattage values and concurrency factors. We present a new methodology to simulate and optimize complex robot driven production systems with special emphasis on energy aspects. In particular, we show how to translate the process descriptions and energy consumption profiles into a discrete-event-based simulation model and illustrate this with an example of a car body shop facility. In order to minimize the peak-load we set up an optimization model that is based on periodic time-expanded networks. A solution of this model corresponds to a process sequence for the robots that prescribes relative starting times via additional wait intervals. This sequence is then reinserted into the simulation model to validate the improvement.
Shape-memory-alloys (SMAs) are easy to integrate into mechanical structures and capable of handling high specific workloads. Therefore, SMAs possess an outstanding potential to serve as positioning devices in various ...
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