Control of Uncertainty Based on Machining Strategies during Reaming

Abstract

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.

Strategies for Mastering Uncertainty

“…A reduced feed rate leads to a decrease of forces, which deflect the tool in the unsteady phase. However, the application of special entry strategies, such as a cubic increase in the feed rate, shows no significant reduction of the medium deflection [74].…”

Adjustment of Axis Offset Errors during Reaming

“…3 (5)) after correction of the axis offset. As an air cut can lead to a high deflection of the reamer [6], it is also examined whether the deflection of the reamer is bigger by the additional countersinking process compared to a normal reaming process. General test conditions.…”

“…However, any uncertainty during the reaming process can negatively affect the quality of boreholes. Basic types of uncertainty are a) parallel displacement of the tool axis along the boring axis, called axis offset, b) offset of the tool's rotation axes in relation to the motor spindle, called eccentricity error or c) sloped pre-drilled bores due to uneven surfaces, material inclusions, different hardness gradients or other material defects [6], see also Fig. 1.…”