A new solution for sharpening helical flute hobs

Sharpening helical hobs with a hob sharpener is relatively easy and efficient, but the hob sharpener has poor versatility due to its tilted spindle for sharpening helical flutes. In this paper, we propose a new solution for sharpening helical flute hobs. Geometrically, we sim-plified the wheel profile to a circular arc, which made it easy to obtain the wheel profile through the circular arc NC (numerical control) function G02 or G03. With the simplified wheel profile, it is much easier to obtain the profile of the wheel made with CBN (cubic boron nitride), even with the use of an ordinary CNC (computer-aided numerical control) contour dressing machine. We also calculated the machine settings for a 5-axis form grind -ing machine, in which the machine settings of a hob sharpener were transformed into through coordinate transformation. With such new machine settings, the helical flute hob can be sharpened by the form grinding machine. Finally, our numerical examples evaluate the variations between the proposed simplified circular arc wheel profile and the theoreti-cal one. Moreover, the results of our experiment using the form grinding machine with the simplified circular arc profile wheel are illustrated in the plots of the measuring machine. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

The paper proposes a new solution for sharpening helical flute hobs by simplifying the wheel profile to a circular arc, making it easier to obtain the wheel profile through numerical control function. Machine settings for a form grinding machine were calculated, allowing the sharpening of helical flute hobs. Numerical examples evaluated the differences between the proposed simplified circular arc wheel profile and the theoretical one.