Sebastian Güth

Deburring of Cross-Drilled Holes with Ball-End Cutters - Modeling the Tool Path

Machining of cross-drilled holes generates burrs on the entrance and exit. Deburring of these intersecting holes is challenging due to the limited accessibility. This paper presents a model that creates a tool path suitable for precision deburring of intersecting holes with a ball-end cutter. The presented model is developed with the help of Computer-Aided-Engineering. The tool generates a three-axis travel path related to the intersection geometry of the main and cross hole. The burr is removed and a constant chamfer is machined. The intersection curve is even machined through the main or cross bore. The presented model is verified by means of experiments with three different intersection samples using the material AlSi7Mg.

Control of Uncertainty Based on Machining Strategies during Reaming

The bore quality is influenced by machine’s accuracy, work piece and tool errors as well as handling errors. This uncertainty has a huge impact on the quality of the finished bore. During reaming, the majority of tool deflection arises during the unsteady process phase. The entry phase is regarded as the biggest influencing factor for the reamer’s deflection with increasing bore depth. This paper examines the influence of various entry strategies on the bore quality during the reaming process.

Control of Uncertainty in High Precision Cutting Processes: Reaming of Valve Guides in a Cylinder Head of a Combustion Engine

In production processes uncertainty has a great impact on the product quality as well as production costs. In automotive industry the reaming of valve guides in a cylinder head of a combustion engine is a quality determining process. Due to the force fitting of the valve guides into the cylinder head the final reaming process has to deal with increased uncertainty. On the other hand, the finished hole is closely tolerated. To ensure the process reliability the admissible tolerance must be strictly met even in case of uncertainty. This paper presents a possibility to achieve process reliability by a modified process chain with an additional pilot reaming tool. Thereby, the effect of different cutting edge preparation is also analyzed. Further, the influence of the pilot reamer geometry on the final hole quality is investigated.