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Modified Cross-Wedge Rolling for Creating Hollow Shafts

Procedia Manufacturing 2018年 21卷 53-59页

作者： Dirk Landgrebe Jürgen Steger Uwe Böhmichen Markus Bergmann Fraunhofer Institute for Machine Tools and Forming Technology (IWU) Reichenhainer Str. 88 09126 Chemnitz Germany

Cross-wedge rolling (CWR) is an incremental forming method for producing rotationally symmetric components such as a basic shape of gear shaft or a preform before impression die forging. In CWR the material of a solid cylindrical billet is redistributed in axial direction while the billet diameter is reduced. Conventional CWR cannot be used to produce hollow shapes. This paper presents a modified CWR process, which enables the manufacturing of hollow shafts and thus provides a technological base for utilizing the large potential of the method regarding cost and resource efficiency in mass production. The method introduces two mandrels which act concurrently with the tooling wedges in an elaborate kinematic system. During processing, the generated shear stresses induce fracturing located along the billet axis. The actively driven mandrels use the fracture and penetrate axially into the workpiece. This paper provides a description of the basic principle of this innovative method and discusses the complex interaction between tool geometries, kinematic system and processing parameters.

关键词： Production Process Hot Forging Cross-wedge Rolling Tubing Billet Preforming

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Detection of the Force Distribution Close to the Effective Site in forming machines for a Force Control

Detection of the Force Distribution Close to the Effective S...

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International Conference on Control, Mechatronics and Automation (ICCMA)

作者： A. Schleinitz A. Sewohl H. Schlegel M. Putz Department of Control and Feedback Control Technology Technische Universität Chemnitz Chemnitz Germany Fraunhofer Institute for Machine Tools and Forming Technology Chemnitz Germany

Ever higher demands are placed on the quality and complexity of formed sheet metal parts, whereby the efficiency of the processes may not be affected. Thus it becomes more difficult to ensure process stability. In order to reduce rejected parts it is necessary to improve forming technologies and processes. Closed loop control of process variables with an influence to the quality of a part is a promising approach. Therefor the reliable metrological acquisition of such a parameter is a basic requirement. forming force respectively force distribution has an influence on component quality and seems to be a suited value. In this paper, a measurement setup and its implementation in a demonstrator is described. First metrological examinations show occurring effects during eccentric load cases and the derivation of spindle forces via additional load paths in the machine frame. This knowledge will be used for the development of a force control.

关键词： Force Force measurement tools Presses Process control Sensor systems

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forming 4.0: Smart machine components applied as a hybrid plain bearing and a tool clamping system

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Procedia Manufacturing 2019年 27卷 65-71页

作者： R. Kurth R. Tehel T. Päßler M. Putz K. Wehmeyer C. Kraft H. Schwarze Fraunhofer Institute for Machine Tools and Forming Technology IWU Reichenhainer Straße 88 09126 Chemnitz Germany Berg & Co. GmbH Gildemeisterstraße 80 33689 Bielefeld Germany Technical University Clausthal Institute of Tribology and Energy Conversion Machinery Leibnizstraße 32 38678 Clausthal-Zellerfeld Germany

Higher process reliability as well as detailed information about the machine condition are necessary requirements for the manufacturing of complex geometric shapes with simultaneous increase of the machine availability and output rate. By implementing smart machine components it is possible to solve central challenges focusing on the investment-intensive field of forming technology. These components gather and evaluate machine and process data on decentralized spots with certain integrated sensors. Within this paper the potential benefits of those smart machine components are demonstrated using the example of an intelligent hybrid plain bearing and a smart tool holder. Focusing on the damage prevention of plain bearings, a load controlled journal bearing combining hydrodynamic and hydrostatic characteristics has been developed and tested by simulation. In addition, a smart hydraulic tool holder for upper dies has been successfully tested by simulations and experiments in order to investigate and demonstrate the potential for using the monitored clamping characteristics to increase the process transparency and the condition of the tool holder. As a result these smart machine components can be used additionally for a significant improvement of industry 4.0 tools such as digital twins of both process and machine.

关键词： industry 4.0 sensor integration plain bearing journal bearing tool clamping condition monitoring smart components process monitoring

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Enhancement and analysis of multidimensional characteristic diagrams for correction of TCP-displacements caused by thermal tool displacement

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Procedia CIRP 2018年 77卷 553-556页

作者： Matthias Putz Christian Oppermann Michael Bräunig Fraunhofer-Institute for Machine Tools and Forming Technology IWU 09126 Chemnitz Germany Chemnitz University of Technology 09010 Chemnitz Germany

In the present paper former developed characteristic diagram approaches for the correction of thermo-elastic TCP-displacements during cutting processes are extended. Input variables linked with the resulting deformations are estimated by Design of Experiments (DoE). Deformations are computed by means of FEA via the estimation of heat fluxes in the system workpiece – chip – tool – clamping device and the temperature field in tool and clamping device. Multidimensional characteristic diagrams are derived to enable real-time correction of tool paths within the machine tool control. These correction approaches are of crucial importance especially in the field of precision machining and difficult-to-cut material generating large heat amounts. With the obtained correction values the effect of the different cutting parameters on the TCP-displacement is investigated in a sensitivity analysis.

关键词： TCP-displacement Thermal error Characteristic diagramm machine Tool Sensitivity analysis Design of Experiments

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A new simulation and optimization tool for calculating the attenuation of airborne and structure-borne sound of maritime silencers 47

A new simulation and optimization tool for calculating the a...

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47th International Congress and Exposition on Noise Control Engineering: Impact of Noise Control Engineering, INTER-NOISE 2018

作者： Lindner, Paul Schulze, Christian Hübelt, Jörn Georgi, Tom Troge, Jan Gesellschaft für Akustikforschung Dresden mbH Blumenstraße 80 Dresden01307 Germany Fraunhofer Institute for Machine Tools and Forming Technology IWU Nöthnitzer Straße 44 Dresden01187 Germany

The acoustical impact of silencers is restricted by the influence of structure-borne sound. Thereby, excitation and radiation of structure-borne sound play an important role, as well as its transmission along the silencer system. In the design process of a silencer the influence of structure-borne sound on the damping effect is mostly considered by empirical estimations, which can cause an oversized construction. For calculating structure-borne sound in maritime silencers with their typical large dimensions, the application of statistical methods is a possible problem-solving approach. In this contribution, a new simulation and optimization tool is presented, considering the decreased damping effect of silencers due to structure-borne sound. The tool is based on Statistical Energy Analysis (SEA). Results of analytical and experimental SEA are compared. These results were obtained on downscaled silencers and have been transferred to real maritime silencers. Especially the SEA-parameters loss factor and coupling loss factor, airborne and structure-borne sound energies and the number of relevant modes are considered. Based on the measured damping of a silencer compared with numerical and statistical calculations, the capability for optimizing the design process of large silencers is shown. © INTER-NOISE 2018 - 47th International Congress and Exposition on Noise Control Engineering: Impact of Noise Control Engineering. All rights reserved.

关键词： Damping

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Verification of a novel measuring method for determining pre- and postoperative leg length in the context of total hip arthroplasty: a technical feasibility study

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Journal of Medical Engineering and technology 2018年第8期42卷 588-594页

作者： Schmidt, Michael Prietzel, Torsten Wendler, Toni Möbius, Robert Schleifenbaum, Stefan Hammer, Niels Grunert, Ronny ZESBO - Center for Research on Musculoskeletal Systems University of Leipzig Leipzig Germany Department of Orthopaedic Trauma and Plastic Surgery University of Leipzig Leipzig Germany Department of Orthopaedic and Trauma Surgery HELIOS Clinic Blankenhain Blankenhain Germany Department of Anatomy University of Otago Dunedin New Zealand Fraunhofer Institute for Machine Tools and Forming Technology Fraunhofer IWU Dresden Germany

Following total hip arthroplasty (THA), leg length can easily be modified, for example by different-sized endoprosthetic components. Currently, precise reconstruction depends mainly on the assessment of the surgeon. The aim of this study was to determine the accuracy of a new optical measuring system (OMS) using a novel measuring method capable of determining changes in leg length. Measurements with different investigators on an artificial leg and under clinical conditions were carried out. Measurements under clinical conditions were accomplished with a human body donor before and following prosthetic hip implantation. Furthermore, computed tomography (CT) was used to compare the function and the precision of the OMS relating to established measuring methods. The following results were achieved. The overall mean result of preoperative leg length determination by the OMS was 775.3 ± 5.8 mm (CT: 786.4 mm). The overall mean result of postoperative leg length determination by the OMS was 776.9 ± 10.8 mm (CT: 795.0mm). Measurements carried out showed that the novel measuring method works in principle. However, the viable prototype based on it has a lower accuracy compared to CT-based reference measurements, indicating the necessity of integrating more precise hardware. © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group.

关键词： Arthroplasty

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Development of a classification and generation approach for innovative technologies

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Procedia Manufacturing 2018年 21卷 798-805页

作者： A.P. Kuznetsov H.-J. Koriath Moscow State University of Technology “STANKIN” 127055 Moscow Russia Fraunhofer Institute for Machine Tools and Forming Technology IWU 09126 Chemnitz Germany

This paper considers the state of the art and analyses five existing classification principles for technological and manufacturing processes aiming at the part and product formation. The proposed energetic-information model describes the generation of technological schemes and processes, based on the system description for structural conversion, transfer and interaction of material, energy and information. Classification principles for technological processes and their structural description generate classes, types and procedures (methods). A generation procedure and mechanism for innovative technological processes is developed. Approved classification of manufacturing processes for DIN8580, NISTIR 7913, according to Todd, Paul De Garmo, by Ashby are particular cases of the proposed classification approach. The proposed approach and process classification system is forming an image of DIN8580. The classification, generation and analysis approach for manufacturing technologies applies for the creation of innovative procedures, manufacturing equipment and systems.

关键词： methods manufacturing processes technology classification

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Ontology-based microservices architecture for industrial assistant systems 12

Ontology-based microservices architecture for industrial ass...

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Smart Systems Integration 2018 - 12th International Conference and Exhibition on Integration Issues of Miniaturized Systems

作者： Singer, Adrian Wenzel, Ken Müller, Jan Langer, Tino Putz, Matthias Digitalization in Production Germany Department Digitalization in Production Germany Automation and Monitoring Germany Head of Division Smart Factory - Digitalization and Automation Germany Institute Scientific Field Machine Tools Production Systems and Machining Fraunhofer Institute for Machine Tools and Forming Technology IWU Reichenhainer Straße 88 Chemnitz09126 Germany

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Target-oriented Analysis of Resource Consumption in Manufacturing Process Chains

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Procedia Manufacturing 2018年 21卷 462-467页

作者： A. Demmer N. Klingbeil F. Klocke M. Putz R. Schmitt T. Vollmer Fraunhofer-Institute for Production Technology IPT Steinbachstrasse 17 Aachen 52074 Germany Fraunhofer-Institute for Machine Tools and Forming Technology IWU Reichenhainer Strasse 88 Chemnitz 09126 Germany

Nowadays, manufacturing companies have to view their resource consumption as a cost driver in order to identify efficient and economical processes. Methodologies for investigating, assessing and comparing process chains are vital in order to gain an accurate insight into cost drivers over the course of the entire process chain [1]. Scrutiny of this nature enables cost drivers to be identified via the parameters process time, machine and staff costs in addition to costs related to energy, material and consumables. A review of the usage phase permits elevated costs during manufacture to be justified by reduced costs during operation. The allocation of costs to resources within individual cost-driving process steps ensures target-oriented derivation of improvement measures. The methodology has been designed to serve as basis for production planning, for example, with regard to (energy and resource) efficiency and applied to low-pressure turbine blades made of nickel-base alloys and titanium aluminide. A dedicated analysis of process chain costs provides an insight into the development of individual production costs. This information forms a basis on which to make decisions regarding output quantity or the most appropriate time for investment in new machines. In conjunction with the process chain comparison, this serves as a basis for the integration of the results obtained into a data base which allows the user to select a goal-oriented process chain selection. The data base can provide information regarding the organization of production chains in order to ensure that the product is manufactured accordingly to reduce resources, energy consumption, process times or overall costs.

关键词： Energy efficiency Manufacturing process Production planning

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Root cause analysis of deep drawing processes with superimposed low-frequency vibrations on servo-screw presses: A practical research on predictability in simulation 15

Root cause analysis of deep drawing processes with superimpo...

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15th International Conference on Informatics in Control, Automation and Robotics, ICINCO 2018

作者： Sewohl, André Kriechenbauer, Sebastian Müller, Peter Schlegel, Holger Landgrebe, Dirk Institute of Machine Tools and Production Processes Chemnitz University of Technology Reichenhainer Straße 70 Chemnitz09126 Germany Fraunhofer-Institute for Machine Tools and Forming Technologies Reichenhainer Straße 88 Chemnitz09126 Germany

ISBN: (纸本)9789897583216

In the area of sheet metal forming, modelling and simulation of deep drawing processes with finite-element analysis are an essential method for an accurate process design and the production engineering of complex parts. The continuous evaluation and qualification of simulation strategies improve the predictability and help to understand complex forming processes. In order to fulfil the constantly growing requirements on product quality and part variety, dimensional accuracy as well as energy and cost efficiency, it is necessary to achieve reasonable forecasting results and optimal parameters. However, the development of enhanced deep drawing techniques supported by vibrations is in general just beginning. Currently, prediction of process parameters as well as the knowledge about effects and coherences of highly dynamic processes with flexible kinematics are insufficient. In this paper, an approach for improvements in simulation of a new technology for deep drawing on servo-screw presses called cushion-ram pulsation is presented. Numerical and experimental model tests in special constructed set-ups have to be performed to determine particular forces. Sensitivity based methods help to identify significant process parameters of complex forming processes with superimposed vibrations. The evaluation of these parameters allows the development of specific meta-models which approximate the behavior in the simulation. Copyright © 2018 by SCITEPRESS – Science and technology Publications, Lda. All rights reserved

关键词： Process design

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