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Quantitative design of extruder dies for rubber compounds and thermoplastics requires a knowledge of the pumping performance of the extruder, for an appropriate extruder-die interaction. The dies are generally formed from a succession of convergent, circular or noncircular ducts with axial varying geometrical dimensions. The design and operation of dies of these types is then a matter of sufficient importance to justify a detailed analysis of the factors involved.

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This paper presents an intelligent, hybrid system for stamping process planning in progressive die design. The system combines the flexibility of blackboard architecture with case-based reasoning. The hybrid system has the advantage that it can use past knowledge and experience for case-based reasoning when it exists, and other reasoning approaches when it doesn’t exist. A prototype system has been implemented in CLIPS and interfaced with Solid Edge CAD system. An example is included to demonstrate the approach. / Singapore-MIT Alliance (SMA)

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In forging industry, the die setup starts with unloading the previous die set and ends with approval of the first part produced. During conventional die setup, forging press is kept idle. The aim of this study is to perform die changing applications of the 1000 ton forging press of Aksan Steel Forging Company in more systematic way to reduce the idle time. The applicability of Single Minute Exchange of Dies (SMED) System and quick die locating methods have been studied. SMED classifies the setup operations as internal and external setup operations. During the internal setup operations the press is kept idle. Therefore it has been tried to reduce the internal setup time. In this study, a new modular die system has been developed. The die system to be used for the forging press with 1000 ton capacity in Aksan Steel Forging Company has been redesigned regarding the dimensional limitations, requirements, SMED System and quick die locating methods. The modules of proposed die system and the dies for a particular forging part have been produced. Tests, observations and time studies have been carried out. The time spent for alignment of the upper and lower dies on the press have been eliminated in the proposed system. The solutions have been proposed for the frequently encountered problems of setup operations of the company and these have been applied in the system. In order to eliminate operator mistakes, marking applications have also been introduced and the application of die cavity revision has been renewed. During the time studies for the case study, it has been seen that the internal setup time of the forging press with 1000 ton capacity has been reduced from 220 minutes to 141 minutes which corresponds to a reduction of 36 %.

Bisherige Bemühungen zur Reduzierung der Rückfederung von Blechbauteilen begrenzten sich hauptsächlich auf die Gestaltung der letzten Formgebungsstufe. In der vorliegenden Arbeit wird ein innovativer Ansatz zur Erhöhung der Maßhaltigkeit durch die Modifikation der Vorziehstufe untersucht. Dabei wird auf Grundlage eines beispielhaften Industriebauteils ein Demonstrator mit einer offenen und einer geschlossenen Kontur entwickelt. Durch die Abbildung der Herstellungsmethode in der Simulation (FEM) lässt sich die Rückfederung beurteilen. Durch die Charakterisierung des Werkstoffverhaltens wird die Qualität der Simulation gesteigert, da die Materialkennwerte (Fließkurve & Grenzformänderungskurve) für die Simulation genauer spezifiziert werden können. Es erfolgt die Variation der Vorziehstufe hinsichtlich geometrischer (Radius & Grad der Vorziehstufe) und prozesstechnischer Parameter (Niederhalterkraft & Schließabstand), sodass nach der Auswertung der Rückfederungsergebnisse Gestaltunghinweise erarbeitet werden. Die Validierung der Simulationsergebnisse wird vorgenommen, indem die Bauteile real hergestellt werden. Dadurch ist es möglich, die Rückfederungen der Simulation und der realen Herstellungsmethode zu vergleichen und die Gestaltungshinweise zu bewerten. / Approaches to reduce springback of sheet metal parts are mainly focused on the last forming stage. This study deals with modifications made on the pre-drawing stage so that an increased dimensional accuracy results. A demonstrator with an open and a closed contour is developed based on an exemplary industrial part. The assessment of springback is conducted by incorporating the manufacturing method into simulation (FEM). To increase the quality of the simulation the characterization of materials is set and hence more information about material properties (flow curve and forming limit curve) is specified. Variations of geometric (radius & proportion of pre-drawing stage) and process parameters (blankholder force & closing distance) are made which purpose the development of design guidelines after evaluation. The simulation results are validated by producing real sheet metal parts. The design guidelines will be feasible/can be assessed if the comparison of the springback results converges between simulation and reality.

The subject of submitted diploma thesis is complete structure of procedures necessary for the designing and subsequent production of forging dies for production of semi-finished connecting rods. The initial part deals with the design of forging die. Following part is consisted of materials used for production of this type of tools. Ensuing is proposal of tooling for machining of the die following with simulation of the milling processes.

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