A typical characteristic of printing machines is their high level of exploitation. But modern offset presses are as well large and complex mechanical systems that use energy in a large variety of electrical drives, fo...
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ISBN:
(纸本)9783642290688
A typical characteristic of printing machines is their high level of exploitation. But modern offset presses are as well large and complex mechanical systems that use energy in a large variety of electrical drives, for heating, air conditioning and drying. Increasing energy prices make the reduction of energy consumption in the operation of printing presses a highpriority, market-relevant issue with an initial target of around 15 %. General and new engineering knowledge provides a variety of possible approaches for reducing energy consumption. The goal is to find an optimal compromise between additional, cost-creating measures for the machine builder and real cost-reducing benefits for the end user.
In this paper the impact of different tool materials, tool coatings, and lubricants onto the micro forming process of micro cavities is investigated. As tool materials two different hardened steels were used for the f...
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ISBN:
(纸本)9780956679000
In this paper the impact of different tool materials, tool coatings, and lubricants onto the micro forming process of micro cavities is investigated. As tool materials two different hardened steels were used for the forming die. To lower the friction and adhesion between forming tool and aluminium substrate three coatings TiN (titanium nitride), TiCN (titanium carbon nitride), and DLC (diamond like carbon) were tested. Furthermore, the influences of different lubricants were studied. Geometric parameters and surface quality were judged by laser microscopy and SEM images of metallographic sections.
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.
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.
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.
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.
One possibility to increase the performance of machinetools is the achievement of higher accelerations and jerks of moved slides and stands. By this the energy consumption and machining-costs can be optimized. Nowada...
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One possibility to increase the performance of machinetools is the achievement of higher accelerations and jerks of moved slides and stands. By this the energy consumption and machining-costs can be optimized. Nowadays machine tool structures are already optimized and further enhancements are not easily achieved. The paper deals with the mechatronic system optimization of a large-scale HSC- and HPC- portal milling centre for e.g. formingtools. This includes the identification of dynamic limiting structures and the following optimization by mechatronic system-monitoring. From process necessities a machining-time reduction by higher accelerations and improved process stability is intended. The system parameters where achieved by the implementation of a redundant axis and the usage of up-to-date lightweight design by reinforced *** over the design phase the structure was constantly monitored regarding their dynamic behaviour. Furthermore a model was used – using a state space – to prejudge the machining time for a concrete example cycle. So even before any physical prototype exists the mechatronic system-behaviour of the machine tool was pre estimated using a virtual mechatronic model. This allows for a virtual product design with a new and improved quality of safety in achieving the pre-defined goals.
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