Improved Roller Hemming System for High Volume Part Production

2011 ◽  
Vol 473 ◽  
pp. 168-175 ◽  
Author(s):  
Martin Zubeil ◽  
Karl Roll ◽  
Marion Merklein
Keyword(s):  
Strain Rate ◽  
Surface Quality ◽  
Automotive Industry ◽  
Dimensional Stability ◽  
Cycle Time ◽  
High Volume ◽  
Non Linear ◽  
Part Production

Roller hemming is usually applied for hang-on-parts such as hoods, doors or trunk-lids which all have complex non-linear geometries. The flange is often hemmed along both surfaces and edges which have 3D curvilinear shapes. Minimization of hemming defects and the requirement to improve cycle time of the roller hemming process are essential for roller hemmed hang-on-parts in the automotive industry. Different systems such as the driven roller hemming provide the possibility to increase the strain rate without loosing surface quality and dimensional stability. Investigating the influence of friction during roller hemming, results will give an understanding of the advantage for mentioned roller hemming systems.

scholarly journals Face Grinding Surface Quality of High Volume Fraction SiCp/Al Composite Materials

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Xu Zhao ◽  
Yadong Gong ◽  
Guiqiang Liang ◽  
Ming Cai ◽  
Bing Han
Keyword(s):  
Friction Coefficient ◽  
Surface Morphology ◽  
Surface Quality ◽  
Volume Fraction ◽  
High Volume ◽  
Spindle Speed ◽  
High Volume Fraction ◽  
Machining Parameters ◽  
Al Composite

AbstractThe existing research on SiCp/Al composite machining mainly focuses on the machining parameters or surface morphology. However, the surface quality of SiCp/Al composites with a high volume fraction has not been extensively studied. In this study, 32 SiCp/Al specimens with a high volume fraction were prepared and their machining parameters measured. The surface quality of the specimens was then tested and the effect of the grinding parameters on the surface quality was analyzed. The grinding quality of the composite specimens was comprehensively analyzed taking the grinding force, friction coefficient, and roughness parameters as the evaluation standards. The best grinding parameters were obtained by analyzing the surface morphology. The results show that, a higher spindle speed should be chosen to obtain a better surface quality. The final surface quality is related to the friction coefficient, surface roughness, and fragmentation degree as well as the quantity and distribution of the defects. Lower feeding amount, lower grinding depth and appropriately higher spindle speed should be chosen to obtain better surface quality. Lower feeding amount, higher grinding depth and spindle speed should be chosen to balance grind efficiently and surface quality. This study proposes a systematic evaluation method, which can be used to guide the machining of SiCp/Al composites with a high volume fraction.

Studies in Direct Tooling Using Stereolithography

1999 ◽  
Vol 122 (2) ◽  
pp. 316-322 ◽  
Author(s):  
Yun Li ◽  
Edward P. Gargiulo ◽  
Michael Keefe
Keyword(s):  
Product Development ◽  
Thermal Characteristics ◽  
Thermal Response ◽  
High Volume ◽  
Production Quality ◽  
Physical Models ◽  
Part Geometry ◽  
Mold Fabrication ◽  
Low Volume ◽  
Part Production

Rapid prototyping (RP) technologies are valuable for reducing product development cycle times by creating physical models for visual inspection and form-fit studies directly from a 3-D database. However, if the part is meant for volume production, tooling will be necessary. Tool development and fabrication using conventional techniques and materials is time consuming and expensive. Therefore, it is risky to commit to production tooling in the initial stages of product development. Low volume prototyping is highly desirable but requires a small number of parts (hundreds) to be produced quickly and economically. To meet this need, this paper studies direct tooling using the RP technology of stereolithography (SL) to produce photopolymer tools. Without modifications to improve thermal response, SL molds will not be able to produce production-quality parts. This experimental study quantifies the thermal characteristics of an SL mold for a simple part geometry. Several modifications that affect thermal properties are then studied and both thermal response and part quality are quantified. The data indicate that although it is possible to change the thermal response of an SL mold and obtain reasonable parts, the ability to duplicate traditional mold characteristics (and thus simulate part production before committing to high-volume tooling) is probably not practical. Similar results were achieved when using a more realistic final-part geometry on a production mold machine. Although mold process simulation using SL molds could provide useful design guidance for traditional high-volume part production, this work suggests that these SL molds can be used for low-volume part production. By reducing mold fabrication time and costs, low-volume part production could become cost-effective using traditional high-volume manufacturing techniques. [S1087-1357(00)00702-4]

scholarly journals The Effect of the Parameters of T-RTM on the Properties of Polyamide 6 Prepared by in Situ Polymerization

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 4 ◽  
Author(s):  
Orsolya Viktória Semperger ◽  
András Suplicz
Keyword(s):  
Mechanical Properties ◽  
Automotive Industry ◽  
Cycle Time ◽  
In Situ Polymerization ◽  
Rapid Development ◽  
Polyamide 6 ◽  
Raw Material ◽  
Short Cycle ◽  
Short Cycle Time

With the rapid development of the automotive industry, there is also a significant need to improve the raw materials used. Therefore, the demand is increasing for polymer composites with a focus on mass reduction and recyclability. Thermoplastic polymers are preferred because of their recyclability. As the automotive industry requires mass production, they require a thermoplastic raw material that can impregnate the reinforcement in a short cycle time. The most suitable monomer for this purpose is caprolactam. It can be most efficiently processed with T-RTM (thermoplastic resin transfer molding) technology, during which polyamide 6 is produced from the low-viscosity monomer by anionic ring-opening (in situ) polymerization in a tempered mold with a sufficiently short cycle time. Manufacturing parameters, such as polymerization time and mold temperature, highly influence the morphological and mechanical properties of the product. In this paper, the properties of polyamide 6 produced by T-RTM are analyzed as a function of the production parameters. We determine the crystallinity and the residual monomer content of the samples and their effect on mechanical properties.

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