Experimental study of wear characteristics during cutting ' V ' - threads

Abstract

There are several factors like relative motion and positionof the tool and work piece, diameter of the work. piece, diameter of the work piece and depth of cut whicl"have a great influence on the tool wear, particularly, quring thread cutting process~ The present study has taken an , attempt to investigate the cl"aracteristics of tool wear duting cutting V-threads. Anumber of threads have been cut with selected- pitch, diameter and depth of threads in order to show the relationships of tool Wear"ith pitch and diameter of threads. wear readings were recorded under microscope for each case. Someimportant characteristics of. tool wear have been found out from this study. All findings have been justified.by some established principles of metal cuttingbased on several past research works. The study shows an important characteristic.' that wears on right cutting edge are al'iays greater than that on left cutting edge for a right cut tool .• Investigations show that cl"ange of static tool geometry during actual cutting process can be considered as responsib.1e for th'is characteristic. ,Ho,;ever, this nature of unequal wani' may lead the tool for regrinding very soon,because Wear on rig:tlt cutting edge reaches its critical value before the Wf'tone. iii In order to avoid this difficu1ty, a mathematical model has been deve10ped to specifY the static tool geometry \<hich could ensure the clesired too1 geometry during actua1 thread cUtting process. The mode1 has considered the effects of relative motion and position of tool and workpiece on tool geometry during eutling process. V1ti- *-6 mate1y, a too1 Was designed according/the tleve10ped mode1 _ and experiment Was conducted further to compare the nature of wear with that of origina1 too1. The result of using modified tool was verJ satisfactory as the wears on both cutting e'dges were, seen a1most equa1 and the overa11 too1 ,wears have been reduced some "hat.