JPS641811U

JPS641811U -

Info

Publication number: JPS641811U
Application number: JP9557387U
Authority: JP
Priority date: 1987-06-22
Filing date: 1987-06-22
Publication date: 1989-01-09
Anticipated expiration: 2002-06-22
Also published as: JPH0627285Y2

Description

[Brief explanation of the drawing]

第１図は、本考案鑞付け式の超硬ドリルにおけ
る一実施例を示す正面図、第２図は、その拡大底
面図、第３図は、第１図中の―線に沿つて得
られる拡大断面図、第４図は、同じく第１図中の
―線に沿つて得られる拡大断面図、第５図は
、変形例を示す拡大断面図、第６図は、切屑排出
溝内で切屑が広がる状況を示す説明図、第７図は
、切屑が分断する状況を示す説明図、第８図は、
本考案品Ａおよび比較品Ｂにおける切削試験結果
を示す説明図、第９図は、本考案品および比較品
Ｃにおける切削試験結果を示す説明図である。１……超硬ドリル、２……工具本体、３……刃
体、５……切屑排出溝、７……ランド部分、８…
…油穴、１０……先端切刃稜、１１……マージン
、１２……切刃コーナー部分。 Fig. 1 is a front view showing an embodiment of the brazing type carbide drill of the present invention, Fig. 2 is an enlarged bottom view thereof, and Fig. 3 is taken along the - line in Fig. 1. FIG. 4 is an enlarged sectional view taken along the line - in FIG. 1, FIG. 5 is an enlarged sectional view showing a modified example, and FIG. FIG. 7 is an explanatory diagram showing a situation in which chips spread, and FIG. 8 is an explanatory diagram showing a situation in which chips are divided.
FIG. 9 is an explanatory diagram showing the cutting test results for the invented product A and the comparative product B. FIG. 9 is an explanatory diagram showing the cutting test results for the invented product and the comparative product C. DESCRIPTION OF SYMBOLS 1... Carbide drill, 2... Tool body, 3... Blade body, 5... Chip discharge groove, 7... Land portion, 8...
...Oil hole, 10... Tip cutting edge ridge, 11... Margin, 12... Cutting blade corner part.

Claims

[Claims for Utility Model Registration] A blade body 3 made of cemented carbide is attached to one end of the bar-shaped steel tool body 2, and a pair of twisted blades are attached in the axial direction of the tool body 2. Chip discharge grooves 5, 5 are formed, and land portions 7, 7 forming tip flanks on cutting and a pair of tip cutting edges are formed at the tips of the chip discharge grooves 5, 5. In a brazing-type carbide drill in which ridges 10, 10 are formed and oil holes 8, 8 are opened in the land portions 7, 7, respectively, the core thickness of the drill is equal to the outer diameter D of the cutting edge. 25-35
%, the groove width ratio in the cross section of the tip part is 0.4
-0.8:1, and the chip discharge grooves 5, 5 have at least one opening edge on the outer circumferential side equally widened from a midway point in the axial direction, thereby increasing the groove width ratio. Starting from the cutting edge corner portion 12 where the tip cutting edge ridge 10 and the outer margin 11 intersect, the outer diameter D of the cutting edge increases from this cutting edge corner portion 12 toward the shank 4 side. A brazing-type carbide drill characterized in that the axial position at which expansion starts is set by the ratio L/D of the axial length L to L/D and is within the range of L/D = 0.5 to 2.5. .