Untersuchungen zum kraftgeregelten Langhubhonen auf multifunktionalen Bearbeitungszentren

(Force-Controlled Long-Stroke Honing on Multifunctional Machining Centers)

Paffrath, K.-U.

Continually growing demands on surface quality and shape accuracy of highly stressed parts require the development of new manufacturing technologies. This result from the fact that in current internal combustion engines the power output is increased, but the size of the components is reduced. Therefore it is necessary to manufacture smaller parts that function properly while resisting high mechanical and thermal stresses under severe tribological conditions. Honing or microfinishing helps to accomplish a surface finish that is able to resist the applied stresses. Honed surfaces are characterized by an improved material ratio and a typical honing structure. A high material fraction minimizes wear of the surface and the honing structure ensures the existence of a lubricant film.

This thesis presents the integration of a honing process with force-controlled infeed into a combination machining center for turning and grinding, which allows many different process chains. Different aspects of the process with regard to the integration, like the development of a suitable honing tool and the machining parameters, were investigated. The process chain turning – grinding – honing and the process chain turning – pre-honing – finish-honing offer the possibility of finish machining in a single clamping setup. These process chains were analyzed, and suitable machining parameters were determined. In addition to the experimental research, an FE simulation of the workpiece deformation and of the contact between honing stone and workpiece was carried out. The validation of the simulation was accomplished by measuring the deformation of the honing tool in different load configurations.

The results of the research show the necessity of an adaptation of turning and grinding process to reduce the machining time and wear in the honing process. The FE simulation reveals the need of different overrun at the top and bottom of the workpiece due to the deformation of the honing tool. After a short machining time, in the process chain turning – grinding – honing, a typical honing structure could already be established. The machined workpieces are characterized by a lower roughness and higher shape accuracy. In the process chain turning – pre-honing – finish-honing, pre-honing allows for a sufficient material removal to eliminate damages of the surface zone. Furthermore, the defects in shape accuracy and surface roughness can be reduced. Finish-honing enables a further reduction of the height of the peaks in the profile. The resulting surface is characterized by smooth plateaus with isolated deep grooves. Results on tool life of the individual honing process steps show the productivity of each process chain.

Published as

Dissertation, Technische Universität Dortmund, Vulkan Verlag, Essen, 2011, ISBN 978-3-8027-8762-1