US 2010/0260568 A1 · THREAD MILLING CUTTER

Abstract

As shown in a development view of FIG. 2, spiral flutes 16a and 16c have a lead angle α different from a lead angle β of spiral flutes 16b and 16d adjacently placed circumferentially to allow the lead angle β of cutting edges 20a and 20c, formed along the spiral flutes 16a and 16c, respectively, to be different from the lead angle α of cutting edges 20b and 20d adjacently placed circumferentially. This causes the cutting edges 20a to 20d to have intervals that axially vary in series such that the cutting edges 20a to 20d have unequal intervals. This results in irregular increase or decrease in milling resistance encountered during milling of a thread, thereby suppressing the occurrence of chatter vibration due to resonance with a capability of milling the thread with excellent milling precision under various milling conditions.

Claims8

Dependent claims

A thread milling cutter having an outer circumferential periphery, formed with multiple non-lead convex ridges, which have cross-sectional shapes, respectively, each in conformity to a thread groove of a targeted internal thread, with a fixed pitch in an axial direction of the thread milling cutter, and plural flutes intersecting with the convex ridges to define plural segmented lands circumferentially formed with plural cutting edges facing the flutes, respectively, wherein:

the plural cutting edges spirally extend in a same direction circumferentially or extend in parallel to the center axis, and have fixed leads, respectively, in which the lead of at least one of the cutting edges is made different from the lead of another cutting edge adjacently placed circumferentially such that the cutting edges are spaced circumferentially at intervals that in series vary in an axial direction.

the plural cutting edges spirally extend in a same direction circumferentially or extend in parallel to the center axis, and have equal intervals circumferentially in a predetermined intermediate position of a thread milling portion, formed with the plural cutting edges, along an axial direction thereof, but have unequal intervals in other areas deviated from the intermediate position toward front and rear ends of the thread milling portion.

Dependencies are inferred from the claim text.

Thread milling cutter

Life of this patent

Thread milling cutter

Life of this patent

Abstract

Claims8