Mechanical Engineering - Theses

Permanent URI for this collection

http://hdl.handle.net/11343/360

Filters

1970 1
1
Reset filters

Settings
Statistics
Citations
Type: Masters Research thesis × Start date: 1960 × End date: 1979 × Subject: drilling and boring ×

Search Results

Now showing 1 - 1 of 1
  • Item
    Thumbnail Image
    A study of the drilling process
    Cheng, C. Y. ( 1970)
    The modern two flute twist drill has been in existence for more than fifty years and the drilling process has become one of the most widely used manufacturing operation. There has hardly been any major alteration in the general appearance of the twist drill despite the various studies on the effect of geometry on drill performance such as tool life and cutting forces. Nevertheless a better understanding of the capabilities and limitations of the twist drill has been made possible by these investigations. The twist drill generates holes by the cutting action of the lips and the indenting action of the chisel edge. The geometry of the lips has been generalized to that of a lathe tool and the cutting action of the lips was reported as similar to single edged oblique cutting. A cutting model for drilling has not been developed possibly because of the complex geometry of the lips and the extruding action of the chisel edge, which is difficult to study. As a result many empirical equations for the prediction of forces have been proposed. In this project the geometry of the various size drills will be studied. Analyses of the mechanics of drilling will be attempted in the hope that a cutting model may be constructed based on established principles of orthogonal and oblique cutting. This is desirable since in the design and application of drilling, like in other topics of metal cutting) it is useful to be able to predict the deformation and cutting forces.