Title:
DRILL
Document Type and Number:
WIPO Patent Application WO/2021/038841
Kind Code:
A1
Abstract:
This three-fluted drill (1) comprises a body (3), discharge grooves (4), cutting flutes (5), thinning flutes (7), and gash sections (8). The body (3) extends centered on an axis (AX). The discharge grooves (4) are provided on an outer circumferential surface (31) of the body (3). The cutting flutes (5) are each provided on a ridgeline portion of the inner surface (41) of each discharge groove (4) and each relief surface (6) of the body (3). The thinning flutes (7) extend radially inward from an edge (51) of each of the cutting flutes (5). The gash sections (8) each have an R section (81) and a straight section (82). First ridgelines (811) of the R sections (81) and the relief surfaces (6) are each curved and extend radially outward from an edge (71) of each thinning flute (7) in a rotation direction (R). Second ridgelines (821) of the straight sections (82) and the relief surfaces (6) each linearly extend radially outward from an edge (812) of each first ridgeline (811), and each connect to the discharge grooves (4) further radially inward than the outer circumferential surface (31).
Inventors:
YAMAMOTO TAKAHIRO (JP)
MAKINO HIROYASU (JP)
MAKINO HIROYASU (JP)
Application Number:
PCT/JP2019/034179
Publication Date:
March 04, 2021
Filing Date:
August 30, 2019
Export Citation:
Assignee:
OSG CORP (JP)
International Classes:
B23B51/00
Domestic Patent References:
| WO2019088013A1 | 2019-05-09 |
Foreign References:
| JP2017042879A | 2017-03-02 | |||
| JPH0529615U | 1993-04-20 | |||
| JP2009148865A | 2009-07-09 | |||
| JP2006281407A | 2006-10-19 | |||
| DE19602566A1 | 1997-07-31 | |||
| JP2016059999A | 2016-04-25 |
Other References:
See also references of EP 4023378A4
Attorney, Agent or Firm:
YAMAMOTO, Hisashi et al. (JP)
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