Up to the present day, literature has already dealt with stockout-costs, but methods to quantify these costs have not been developed until now. The absence of these kinds of methods prevents an efficient logistic positioning between stockout-costs and the costs for holding safety-stocks. The costs for safety-stocks in a warehouse to provide a desired service-level can already be determined, but the stockout-costs connected with a desired service-level cannot be quantified yet. This article introduces a mathematical function to quantify the costs in a company’s production caused by missing material, depending on the amount of missing material and its missing time.
stockout costs, material shortage, service-level, logistic costs, warehouse costs
Next generation wind turbines are to be built higher and higher. As a result of the stronger and more regular wind in greater altitudes, more energy gain can be achieved by rising hub heights of wind turbines. However, the risk of tower failure rises with tower height and mass.
xxl-product, large-scale, xxl, wind turbine, wind power, lightweight construction, tower constructio
The challenges of integrating the welding process into the sheet metal working tool are handling the emissions and associated pollutions of the tool as well as creating a reliable monitoring-system for the welding-process. Within the scope of a research project, a reliable technology for the integration of condenser discharge (CD) stud welding with tip ignition was developed and tested. It complements existing solutions for integrated resistance welding processes. Due to its high-speed capability, low insertion of energy and high process reliability, this technique is particularly suitable for the integration in sheet metal working tools. A newly developed exhaustion-system is installed and tested for the first time. The new technology produced top quality CD arc stud welding along with high process stability and robustness in long-term tests.
sheet metal, capacitor discharge arc stud welding, cd arc stud welding, tip ignition, follow-on tool
In standard sheet metal forming processes the subsequent welding is executed outside the forming press. Because of that spatial separation complex handling and transferring operations are being required which result in a deterioration of the joint accuracy. The challenges of integrating the welding process into the sheet metal working tool are handling the emissions and associated pollutions of the tool as well as creating a reliable monitoring-system for the welding-process. Within the scope of a research project, a reliable technology for the integration of condenser discharge (CD) stud welding with tip ignition was developed and tested. Due to its high-speed capability, low insertion of energy and high process reliability, this technique is particularly suitable for the integration in sheet metal working tools. The new technology produced top quality CD arc stud welding along with high process stability and robustness in long-term tests.
sheet metal, capacitor discharge arc stud welding, cd arc stud welding, tip ignition, follow-on tool
While merely solutions for integrated resistance welding have been known until now, a tool technology in a reliable process for the functional integration of initial contact capacitor discharge (CD) arc stud welding was developed in a research project. This technology is particularly well-suited to integration into sheet metal working tools, amongst other reasons, because of its high joining speed, low energy input and high process reliability. In endurance tests, this new technology can be used in order to manufacture high-quality stud welds with a high robustness to disturbing variables at the same time, not least due to the fact that the extraction of welding spatter was tried out for the first time.
sheet metal, capacitor discharge arc stud welding, cd arc stud welding, tip ignition, follow-on tool
To realise integration, a new modular tool concept was developed in a research project. However, negative process effects like weld splatters occur. As a counteraction the control of process parameters, an extraction system and mechanical solutions were developed. Focus of this research project was to demonstrate process stability and reachable numbers of strokes. Welding tests with a developed joining step within a progressive die showed good joining results and high process stability. Welded studs were examined by reverse bending experiments and achieved maximum values pointing to the sheet material were used. Disturbances were introduced reliably detected by process monitoring of the voltage and current curve progression as well as the bolt movement. The analysis of the measurements showed the robustness of the automated welding process. Welding emissions were efficiently removed by suction from the shielded welding area in the tool without compromising on joining qualities.
sheet metal, capacitor discharge arc stud welding, cd arc stud welding, tip ignition, follow-on tool
Having new potential applications in forging processes in mind, composites of an ordered mesoporous carbon and luminescent metal phosphate nanocrystals were synthesized for the first time. Three kinds of CMK-3/CePO4:Tb nanocomposites were prepared by treating a mesoporous CMK-3 host with different lanthanide phosphate precursor solutions. Various tests showed that in two cases the nanocrystals were located inside the mesopores, whereas in the third case the nanocystals merely adhered to the outer surfaces of the carbon particles. A preliminary evaluation of the lubrication properties of the CMK-3 and one nanocomposite material was performed. The friction factors determined by means of ring upsetting tests revealed that the carbon materials were able to lower frictional forces although they were 3–4 times less efficient than a commercial graphite-based reference lubricant.
lubricant, forging, cmk-3, cepo4:tb, mesoporous carbon, nanocomposites
Condition-based maintenance of production equipment offers a better trade-off between availability and maintenance costs than other maintenance strategies. A novel approach for determining and predicting the plant condition is presented. The approach applies methods of artificial intelligence to a distributed database covering the entire life cycle of the equipment. The approach simplifies the introduction of condition-based maintenance by means of machine learning and is especially suited for equipment with unknown fault behaviour.
condition-based maintenance, condition forecast, artificial intelligence, distributed data managemen
In this paper an efficient phase-out planning method is presented.
phase-out planning, supply chains
The increasing demands customers are placing force companies to cooperate closely in supply chains in order to ensure a high logistic performance. The customers’ demands also enhance the shortening of product life cycles which cause more frequent phase-outs of products and components in supply chains. Therefore today’s supply chains must be able to conduct phase-outs efficiently. This paper presents a suitable approach for a systematic phase-out planning taking the whole supply chain into consideration. The approach is based on the cumulative production figure principle which allows the linkage of supply chain processes. It supports an alignment of the lot sizes of the processes source, make and deliver to the phase-out production volume. The approach enables supply chain partners to identify possible cost reductions in terms of avoiding remaining stock due to nonharmonized lot sizes.
factory and production planning, networking in international production/manufacturing and logistic n
In the forging industry, cross wedge rolling is a well-established process for production of cylindrical pre-forms with a highly efficient material utilization. To prevent the appearance of material defects during forming, the wedge geometry of the tools is adjusted to the designated pre-form. Today, cross wedge rolling is executed within the hot temperature range. To analyze warm cross wedge rolling, the scientists at IPH - Institut für Integrierte Produktion gemeinnützige GmbH developed a test site for cross wedge rolling experiments.
warm forging, process chain, cross wedge rolling
Cross wedge rolling is used today in the hot temperature range. A test stand for cross wedge rolling tests was developed by the IPH - Institute of Integrated Production to examine this process even with warm component temperatures. The developed test rig for CWR allows practical examination of the influence of different workpiece and tool temperatures, tool geometries and rolling speeds on the forming result. The results of the practical experiments will give insight on customized design of wedge tool geometries, forming velocities as well as tool temperatures for warm and hot cross wedge rolling. Within the project DeVaPro the test rig makes an important contribution to the implementation of a complete custom made technical process chain in warm temperature range.
warm forging, process chain, cross wedge rolling
Warm forged parts have advantages in comparison to conventional hot forged parts: Closer tolerances, reduced surface roughness, no scale and reduced decarburization. However, the geometrical spectrum of warm forged parts is restricted by high flow stress. To overcome this geometrical limitation new rolling and forging processes are developed in the European research project "DeVaPro - Development of a Variable Warm Forging Process Chain". The focus is on the layout of a warm preforming operation by cross wedge rolling followed by an intermediate heating and warm final forming in conventional dies. To get an idea of the effect of lower temperatures on process parameters, e.g. force, die wear and microstructure as opposed to hot forging processes, FE-simulations and experimental tests with a model are performed. In this paper a new warm cross wedge rolling process is introduced and results of experimental tests e. g. mechanical characteristics and microstructure are shown.
warm forging, process chain, cross wedge rolling
To overcome the geometrical limitation of warm forging, in the European research project "DeVaPro - Development of a Variable warm forging Process chain" new rolling and forging processes are developed. The aim of the project is to develop a warm forging process chain by selecting the best suitable hot preforming technology to obtain the desired mass distribution before warm forging. The technology will be adapted to the specific requirements of warm forming. A warm rolling operation and an induction reheating process will be introduced within this project. A steering link and a connecting rod are used as sample parts.
warm forging, process chain, cross wedge rolling
Reducing the process steps, the number of tools and the needed amount of material are the main advantages of combining flashless forming with punching of forged parts. This process was designed at IPH – Institut für integrierte Produktion Hannover. Even the post-processing is reduced drastically because the tolerances are sufficient for most of the applications. The ressearchers developed one tool concept for two different parts. The first is close to a gear wheel and rotationally symmetric, the second is an elongated geometry. Finally the innovative tool concept was successfully tested
flashless precision forging, punching, tool design
Many forged construction components, such as conrods or ring spanners, have hollow cavities, holes or breaks, which are made in a further process step, usually by hot punching. A combined forging and punching method developed by the Institut für Integrierte Produktion Hannover gemeinnützige GmbH (IPH-Hanover Institute for Integrated Production, non profit company) enables the integration of the punching into the precision forming process.
flashless precision forging, punching, tool design
Flashless precision forging is a high quality process which is used to produce near net shape forgings in the tolerance class from IT 8 to IT 10. Representative parts produced by this process are gear-wheels or joint heads. Many forged parts have drillings e.g. as bearing surfaces. These parts are produced in two separate processes: forging and the through hole piercing process. Scope of a research project of the IPH - Institute of Integrated Production Hannover is to realize the combination of the two processes into one flashless precision forging process. Example parts are a rotation-symmetric part similar to gear-wheels and a part with a distinct longitudinal axis which is similar to joint heads. For both parts the forging process was simulated and forged on a screw press. It was shown that a combined forging/piercing process is feasible. Further investigations of the microstructure and the quality of the drilling surfaces of both parts are planned for comparison.
flashless precision forging, punching, tool design
Resources and cost efficiency as well as process optimisation are key factors in today’s market. The competition pressure in forging industry is increasing steadily. Today, parts with openings, cut outs or something similar are punched and partially deburred in hot state after the actual forging process. The combination of forging and punching in one process offers the opportunity to save money and time.
flashless precision forging, punching, tool design
Many forged parts have drillings e.g. as bearing surfaces. These parts are produced in two separate processes: forging and the through hole piercing process. Scope of a research project of the IPH - Institute of Integrated Production Hannover is to realize the combination of the two processes into one flashless precision forging process. This combination lowers the process time, the amount of raw material and the number of tools and faults. Example parts are a rotation-symmetric part similar to gear-wheels and a part with a distinct longitudinal axis which is similar to joint heads. For both parts the forging process was simulated and forged on a screw press. It was shown that a combined forging/piercing process is feasible. Further investigations of the microstructure and the quality of the drilling surfaces of both parts are planned for comparison
flashless precision forging, punching, tool design
Efficiency, reducing costs and optimization are important factors for companys. Achieving this means to reduce the amount of raw material, production time and production steps. IPH – Institut für integrierte Produktion Hannover has developed a combined process for piecing and flashless forging that shortens the number of steps within the process. This new operation is suitable for rotation-symmetric parts as well as for elongated parts. Combing forging and piercing leads to less requirement of raw material and a shortend process time. This was successfully testesd at IPH.
flashless precision forging, punching, tool design
