Lateral Vibrations in Deep Hole Drilling Due to Land Width Variation

Marcel Volz,Eberhard Abele,Matthias Weigold

doi:10.3390/jmmp4020028

Abstract

In drilling processes, self-excited vibrations have a negative influence on the achievable drilling qualities and tool life. Low-frequency radial vibrations are characterised by oscillating movements of the tool tip and the generation of lobed holes in drilling. This study focuses on the participation and influence of the land widths of twisted drilling tools on these vibrations. Therefore, drilling tools with different land widths and a length-to-diameter ratio of 12 are used, and different parameters, such as feed rate, cutting speed, coolant pressure, pre-hole diameter, and chuck selection, are varied in a drill-out process. The results show that the land widths have a statistically significant influence on the formation of lateral vibrations and the generation of lobed holes.

Highlights

Drilling with twist drills is the most commonly used machining process in various industries, such as the automotive, aerospace, dies/molds, home appliance, medical, and electronic equipment industries [1]
The results show that the land widths have a statistically significant influence on the formation of lateral vibrations and the generation of lobed holes
This leads to a reduction in the supporting effect of the drilling tool in the hole and to a reduction in the ability to withstand lateral vibrations

Summary

Introduction

Drilling with twist drills is the most commonly used machining process in various industries, such as the automotive, aerospace, dies/molds, home appliance, medical, and electronic equipment industries [1]. Vibrations during the drilling process are generally undesirable as they produce a poor surface quality and have a negative effect on tool life. Galloway [4] investigated the hole qualities that could be produced using twist drills He varied the tool geometries and technology parameters and investigated their effect on the hole quality and the formation of lateral vibrations. [7] Existing mathematical models describe the oscillating motion mechanisms of the tool tip and their effects on the circularity. In most cases, these models consist of a dynamic partial model which characterizes the vibrating tool-workpiece system. These models consist of a dynamic partial model which characterizes the vibrating tool-workpiece system. [7,8,9,10,11] With an extension from a straight cutting edge to complex cutting edge geometry, a multitude of tool

Methods

Results

Discussion

Conclusion