Drill bit structure

摘要

The present invention relates to a drill bit structure which comprises a body. The body has a free end, an intermediate section and a connection end. The body comprises a first groove portion, a second groove portion, a third groove portion, a fourth groove portion and a fifth groove portion. The first groove portion is partially overlapped with the third groove portion from the free end. The second groove portion is partially overlapped with the fourth groove portion from the free end. After extending a preset axial distance from the free end, the first groove portion and the second groove portion are partially overlapped with each other by forming an intersecting protrusion. The fifth groove portion is extended from the intermediate section toward the connection end. The first, second, third and fourth groove portions are extended to the fifth groove portion.

主权项

1. A drill bit structure comprising:
a body including a free end, an intermediate section and a connection end, said intermediate section located between said free end and said connection end, said connection end arranged opposite to said free end, a first largest outer diameter provided in a region between said free end and said intermediate section, wherein said body has a total axial length defined by an axial distance from said free end to said connection end, and said body further comprising:
a first groove portion which is a flute helically extended from said free end toward said connection end;a second groove portion which is a flute arranged opposite to said first groove portion and helically extended from said free end toward said connection end; after said first groove portion and said second groove portion are separately and respectively extended from said free end for a preset axial distance, said first groove portion and said second groove portion are partially overlapped with each other by forming an intersecting protrusion; terminals of said first groove portion and said second groove portion respectively having a first contour and a second contour near said connection end, and said first contour and said second contour connected with each other by said intersecting protrusion;a third groove portion which is a flute arranged between said first groove portion and said second groove portion, said third groove portion helically extended from said free end toward said connection end for a third axial distance and partially overlapped with said first groove portion from said free end for a first axial length, wherein said third axial distance ranges between 6% and 36% of said total axial length and said first axial length ranges between 3% and 35% of said total axial length;a fourth groove portion which is a flute arranged opposite to said third groove portion and between said first groove portion and said second groove portion, said fourth groove portion helically extended from said free end toward said connection end for a fourth axial distance and partially overlapped with said second groove portion from said free end for a second axial length, wherein said fourth axial distance ranges between 6% and 36% of said total axial length and said second axial length ranges between 3% and 35% of said total axial length; anda fifth groove portion which is an annular groove extended from said intermediate section toward said connection end for a fifth axial distance, a second largest outer diameter provided in a region between said intermediate section and said connection end, said second largest outer diameter smaller than said first largest outer diameter; said first groove portion, said second groove portion, said third groove portion and said fourth groove portion extended to said fifth groove portion, wherein said fifth axial distance ranges between 70% and 95% of said total axial length.