Verfahren, Vorrichtung und Hilfselement zur Halterung eines Werkstücks

Verfahren, Vorrichtung und Hilfselement zur Halterung eines Werkstück

Greif- und Positioniereinrichtung zum Transport einer Spannvorrichtung zwischen unterschiedlichen Positionen

Greif- und Positioniereinrichtung zum Transport einer Spannvorrichtung zwischen unterschiedlichen Positione

Semi-Automated Design Workflow for Bolt Clamping Interfaces to Post-Process Additive Manufactured Parts

Metal additive manufacturing (AM) enables the production of complex and individualized designs. However, most AM parts require postprocessing with subtractive manufacturing processes, which can account for a significant percentage of the total manufacturing cost of an AM part. Positioning and clamping of complex AM parts within post-processing machines often lead to increased prestresses and reduced tool accessibility. One concept to address this problem is the integration of clamping interfaces in the part. But this leads to the new design challenge of optimal and material-saving placement of clamping interfaces on the part. To overcome this challenge new design tools are desired that facilitate this work and automatically generate the design of clamping interfaces. A recently developed clamping system uses bolts that are directly printed onto parts as clamping interfaces. These printed bolts and the clamping jaws of the system enable a unique spatial positioning and rigid clamping of AM parts for post-processing. This work introduces a design workflow that supports the positioning of bolts using a knowledge-based engineering (KBE) approach. The workflow thus allows the user to easily find a feasible clamping configuration and automatically generates the geometries of the bolt-shaped clamping interfaces. As input, the workflow uses the part geometry and an AM build direction. During the workflow, the user can modify the position of the clamping system relative to the part and find feasible positions for bolts. The bolt geometries are then generated automatically, and the part can be exported. This paper describes the workflow in detail and provides a vision for future developments of the tool and its potential for the AM process chain.ISSN:2212-827

Design and validation of integrated clamping interfaces for post-processing and robotic handling in additive manufacturing

Additive manufacturing (AM), particularly laser-based powder bed fusion of metals (LPBF), enables the fabrication of complex and customized metallic parts. However, 20-40% of the total manufacturing costs are usually attributed to post-processing steps. To reduce the costs of extensive post-processing, the process chain for AM parts has to be automated. Accordingly, robotic gripping and handling processes, as well as an efficient clamping for subtractive machining of AM parts, are key challenges. This study introduces and validates integrated bolts acting as a handling and clamping interface of AM parts. The bolts are integrated into the part design and manufactured in the same LPBF process. The bolts can be easily removed after the machining process using a wrench. This feasibility study investigates different bolt elements. The experiments and simulations conducted in the study show that a force of 250 N resulted in a maximum displacement of 12.5 mu m. The milling results of the LPBF parts reveal a maximum roughness value, Ra, of 1.42 mu m, which is comparable to that of a standard clamping system. After the bolt removal, a maximum residual height of 0.067 mm remains. Two case studies are conducted to analyze the form deviation, the effect of bolts on build time, and material volume and to demonstrate the application of the bolts. Thus, the major contribution of this study is the design and the validation of standardized interfaces for robotic handling and clamping of complex AM parts. The novelties are a simple and clean interface removal, less material consumption, less support structure required, and finally an achievement of a five-side tool accessibility by combining the interfaces with a three-jaw chuck.ISSN:0268-3768ISSN:1433-301

Design and validation of a sheet metal clamping system for additive manufacturing and post-processing

Automated clamping for post-processing of mass-customized parts is a challenging step in the laser powder bed fusion (LPBF) process chain. In this study, a novel modular sheet metal clamping system was developed that uses disposable sheet metal profiles as a universal interface for the LPBF, robotic handling, and milling processes. Based on a fundamental investigation of hybrid additive manufacturing, the sheet metal clamping system was designed to use the same interface for the LPBF and milling processes. Subsequent an end-to-end validation was performed for the entire process chain. The concept of the sheet metal clamping system gives milling tools access to a part on five to six sides. Further, the part can be accessed from the top and bottom sides, and simplifying the removal of LPBF supports. No clamping forces are induced in the LPBF part, which is especially important for filigree structures. The sheet metal clamping system’s underlying concept could be adapted to automating the LPBF process chain for applications such as prosthetic dentistry.ISSN:0268-3768ISSN:1433-301