Title:
RING-SHAPED HOLE CUTTER
Document Type and Number:
WIPO Patent Application WO/2011/158378
Kind Code:
A1
Abstract:
Disclosed is a ring-shaped hole cutter capable of smoothly discharging chips. The ring-shaped hole cutter includes a plurality of cutting blades comprising a first cutting blade (38a) and a second cutting blade (38b) disposed alternately in the circumferential direction at the front end surface of the ring-shaped hole cutter. A cutting edge (42b) of the second cutting blade includes a portion that extends radially outward from the radially inner end of the radially inner portion of the cutting edge (42b), and the extending portion inclines further toward the front of the ring-shaped hole cutter the more the extending portion faces radially outside. A gash surface (52) of a gash (36) adjoining the front side of the second cutting blade in the rotational direction includes: a gash inner inclined surface (54b) which inclines further to the rear of the ring-shaped hole cutter the more the gash inner inclined surface (54b) faces radially outside from the radially inner edge of the gash surface (52); and a gash outer inclined surface (54c) which continues to the gash inner inclined surface and inclines further to the rear than the gash inner inclined surface the more the gash outer inclined surface (54c) faces radially outside from the gash inner inclined surface, and which continues to an inner wall surface of a flute where the gash is disposed. The gash outer inclined surface defines a passage (56) in the direction in which chips are sent out toward the flute after the chips are cut from the radially inner portion of the cutting edge of the second cutting blade.
Inventors:
CHIBA, Takashi (9-4, Nakaikegami 2-chome, Ohta-k, Tokyo 55, 〒1468555, JP)
千葉 隆志 (〒55 東京都大田区仲池上２丁目９番４号 日東工器株式会社内 Tokyo, 〒1468555, JP)
千葉 隆志 (〒55 東京都大田区仲池上２丁目９番４号 日東工器株式会社内 Tokyo, 〒1468555, JP)
Application Number:
JP2010/060387
Publication Date:
December 22, 2011
Filing Date:
June 18, 2010
Export Citation:
Assignee:
NITTO KOHKI CO., LTD. (9-4 Nakaikegami 2-chome, Ohta-ku Tokyo, 55, 〒1468555, JP)
日東工器株式会社 (〒55 東京都大田区仲池上２丁目９番４号 Tokyo, 〒1468555, JP)
CHIBA, Takashi (9-4, Nakaikegami 2-chome, Ohta-k, Tokyo 55, 〒1468555, JP)
日東工器株式会社 (〒55 東京都大田区仲池上２丁目９番４号 Tokyo, 〒1468555, JP)
CHIBA, Takashi (9-4, Nakaikegami 2-chome, Ohta-k, Tokyo 55, 〒1468555, JP)
International Classes:
B23B51/04
Attorney, Agent or Firm:
ITOH, Shigeru (9F Ozawa Bldg, 21-18 Toranomon 1-chome, Minato-k, Tokyo 01, 〒1050001, JP)
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Claims: