Title:
DRILL
Document Type and Number:
Japanese Patent JP3450278
Kind Code:
B
Abstract:
PROBLEM TO BE SOLVED: To suppress chipping of a cutting edge of a drill and to improve cutting ability and chip handling ability.
SOLUTION: A chisel 3 and the cutting edge 4 are disposed at the tip of a drill body 2, and two strips of torsion grooves 5 and 5 and two strips of margins 6 and 6 are provided for the outer periphery of the drill body 2. The cutting edge 4 comprises a linear straight part 4a formed on the axis center side of the drill body 2 in the view from a direction orthogonal to the shaft core of the drill body 2, and a projecting bent part 4b for connecting the terminal end B of the straight part 4a to the starting end A of the margin 6 in a projecting bent shape. Curvature of the projecting bent part 4b increases as the part approaches to the margin 6.
Inventors:
Hayazaki, Hiroshi
Ikeuchi, Hiroshi
Aoki, Taichi
Inoue, Takeshi
Ikeuchi, Hiroshi
Aoki, Taichi
Inoue, Takeshi
Application Number:
JP2000000223001
Publication Date:
July 11, 2003
Filing Date:
July 24, 2000
Export Citation:
Assignee:
MMC KOBELCO TOOL KK
MITSUBISHI MATERIALS CORP
MITSUBISHI MATERIALS CORP
International Classes:
B23B51/02; B23B51/00; B23B51/02; B23B51/00; (IPC1-7): B23B51/00
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