JPS6412716U

JPS6412716U -

Info

Publication number: JPS6412716U
Application number: JP10669387U
Authority: JP
Priority date: 1987-07-09
Filing date: 1987-07-09
Publication date: 1989-01-23

Description

[Brief explanation of the drawing]

第１図はこの考案に係るドリルの側面図、第２
図は第１図の―線に沿つた断面図、第３図は
同じく―線に沿つた断面図、第４図は従来例
のドリルの側面図、第５図は第４図の―線に
沿つた断面図、第６図は同じく―線に沿つた
断面図、第７図と第８図はそれぞれ本考案のドリ
ルと従来例のドリルの切削テストにおけるトルク
の変化をパターン化して示す図である。１……刃部、２……先端部、３……ねじれ溝。 Figure 1 is a side view of the drill according to this invention, Figure 2 is a side view of the drill according to this invention.
The figure is a sectional view taken along the line - of Fig. 1, Fig. 3 is a sectional view taken along the - line of Fig. 1, Fig. 4 is a side view of a conventional drill, and Fig. 5 is a sectional view taken along the - line of Fig. 4. Figure 6 is a cross-sectional view along the same line, and Figures 7 and 8 are diagrams showing patterns of torque changes in cutting tests for the drill of the present invention and the conventional drill, respectively. be. 1...Blade part, 2...Tip part, 3...Twisted groove.

Claims

[Scope of claim for utility model registration] (1) The lead angle of the helical groove is 25° to 3.5° within a length range of 0.6 to 1.5 times the drill diameter from the tip of the blade.
0°, and the ratio of the groove width in the circumferential direction of the helical groove to the outer periphery of the drill (groove width ratio) is set to 0.4 to 1.0:1, and the range exceeding the above range and reaching the rear end of the blade. Then, the lead angle was changed to 0°, and the groove width ratio was changed from 0.8:1 to 1.5:1.
A drill that has been changed to widen the range from . (2) The drill according to claim 1, wherein the twisted groove at the rear end of the blade part is a straight groove with a predetermined length and a lead angle of 0°. .