Title:
DRILL
Document Type and Number:
WIPO Patent Application WO/2010/029891
Kind Code:
A1
Abstract:
A drill is configured such that a curve of a hole due to a jumping rope phenomenon is prevented by a guide section and damage to the inner wall surface of the hole is prevented to improve surface roughness.
Cut debris discharge grooves (4) are formed in the outer periphery of a shaft-shaped drill body (1) rotated about the axis (O) thereof, and the cut debris discharge grooves (4) extend from flank surfaces (3) on the tip of the drill body toward the rear end side. Cutting edges (2A) are formed at ridges at which wall surfaces (4A) of the cut debris discharge grooves (4) and the flank surfaces (3) cross each other, and the wall surfaces (4A) face the direction (T) of rotation of the drill. A cutting edge section (2) on the tip side of the drill body (1), at which cutting edge section (2) the cutting edges (2A) are formed, is configured such that the diameter of that portion of the cutting edge section (2) which is on the rear end side in the axis (O) direction is set smaller than the outer diameter (D) of the cutting edges (2A). Guide sections (6) are formed on the rear end side of the cutting edge section (2), and the guide sections (6) have, on the tip outer peripheral side, maximum outer diameter sections (6A). The maximum outer diameter sections (6A) have a diameter which is greater than the outer diameter of the cutting edge section (2) at the rear end thereof and which is the same as or smaller than the outer diameter (D) of the cutting edges (2A). The maximum outer diameter sections (6A) of the guide sections (6) have a smooth projecting curve in a rotation locus about the axis (O).
Inventors:
YANAGIDA KAZUYA (JP)
NARUKE KOICHIRO (JP)
NARUKE KOICHIRO (JP)
Application Number:
PCT/JP2009/065468
Publication Date:
March 18, 2010
Filing Date:
September 04, 2009
Export Citation:
Assignee:
MITSUBISHI MATERIALS CORP (JP)
YANAGIDA KAZUYA (JP)
NARUKE KOICHIRO (JP)
YANAGIDA KAZUYA (JP)
NARUKE KOICHIRO (JP)
International Classes:
B23B51/00
Foreign References:
| JPH04226707A | 1992-08-17 | |||
| JPH04327684A | 1992-11-17 | |||
| US5807039A | 1998-09-15 | |||
| US5697460A | 1997-12-16 | |||
| JPH0475811A | 1992-03-10 | |||
| JPS48114379U | 1973-12-27 | |||
| JP2007196318A | 2007-08-09 |
Other References:
See also references of EP 2322303A4
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