Twist drill and method for producing a twist drill which method includes forming a flute of a twist drill

US9199315B2 · kind B2 · utility

Assignee

• KENNAMETAL INC. · US

Inventors

• Dieter Muhlfriedel · Ebermannstadt, DE
• Bernhard Borschert · Bamberg, DE
• Jürgen Schwägerl · Vohenstrauß, DE

Key dates

• Filing date: Sep 20, 2010
• Grant date: Dec 1, 2015
• Expiry date: Apr 4, 2032

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B23B2251/406
• WIPO field: Machine tools
• WIPO sector: Mechanical engineering

Abstract

There is now provided a twist drill and a method for producing a twist drill which method includes forming a flute of a twist drill. The drill has drill material and a tip portion with a cutting lip. The drill has a land structure and a flute to remove chip residue. The land structure has a flute wall and a cutting edge structure that is disposed longitudinally along the flute wall. The cutting edge structure has a first portion at the drill tip portion and a second portion disposed away from the drill tip portion. The flute wall extends further into the land structure at the second portion of the cutting edge structure than at the tip portion to provide a greater amount of drill material at the tip portion than at the second portion of the cutting edge structure. The flute wall extends further into the land structure at the second portion of the cutting edge structure than at the tip portion to provide a greater flute volume per length at the second portion of the cutting edge structure than at the drill tip portion. The method provides for forming a drill with a grinding tool to form different angular transitions of the cutting edge structure.