JPH0179503U

JPH0179503U -

Info

Publication number: JPH0179503U
Application number: JP1987174317U
Authority: JP
Priority date: 1987-11-12
Filing date: 1987-11-12
Publication date: 1989-05-29

Description

[Brief explanation of the drawing]

第１図は、この考案のドリルの一例を示す側面
図、第２図はその正面図、第３図は要部の拡大側
面図、第４図はスローアウエイチツプの拡大正面
図、第５図は他の実施例の要部を示す側面図、第
６図はセンタードリルの変形例を示す正面図、第
７図は同図に併記した２種類のドリルの背分力デ
ータを示すグラフ、第８図のイ，ロ，ハ，ニは、
切屑形状の違いを示す図、第９図は従来ドリルの
一例を示す側面図である。１……本体、２……センタードリル、２ａ……
切刃、２ｂ……ランド、３……スローアウエイチ
ツプ、３ａ，３ｂ……切刃となる辺、４……ニツ
ク、５……止めねじ、６……切欠溝、θ_１，θ_２……３ａ，３ｂの辺の交差角、θ，θ_３，θ_４…
…切刃角。 Figure 1 is a side view showing an example of the drill of this invention, Figure 2 is its front view, Figure 3 is an enlarged side view of the main parts, Figure 4 is an enlarged front view of the throw-away tip, and Figure 5. 6 is a front view showing a modified example of the center drill, FIG. A, B, H, and D in Figure 8 are
FIG. 9 is a side view showing an example of a conventional drill. 1...Main body, 2...Center drill, 2a...
Cutting blade, 2b...Land, 3...Throwaway tip, 3a, 3b...Side that will become the cutting edge, 4...Nick, 5...Set screw, 6...Notch groove, θ ₁ , θ ₂ ...The intersection angle of sides 3a and 3b, θ, θ ₃ , θ ₄ ...
...cutting edge angle.

Claims

[Claims for Utility Model Registration] (1) A center drill is placed at the center of rotation at the tip of the main body, and on both sides of the center drill are obtuse intersections where the sides that will become cutting edges intersect at an angle of θ ₁ . A hexagonal positive indexable tip with alternating intersections that intersect at an angle of θ ₂ (=240 - θ ₁ ) is used, with any one of the obtuse-angle intersections located behind the cutting edge of the center drill. (Point P), and furthermore, the inner end touches the center drill, and the outer end reaches the outside diameter of the drill. A throw-away drill that is arranged symmetrically with respect to the rotation axis. (2) Utility model registration claim No. (1) characterized in that the center drill is provided with a notched groove in a land portion symmetrical about the rotational axis for engaging the inner ends of each of the throwaway tips. Throw-away drill described in section. (3) Crossing angle θ of the sides of the throwaway chip above ₁ is 130 to 170 degrees, and θ ₂ is 70 to 110 degrees.
Throw-away drill described in paragraph (1) or paragraph (2). (4) Each of the above throwaway tips has θ ₁
= 130 to 170°, and if the inclination angle (cutting edge angle) of the cutting blade on the outer peripheral side of the above point P with respect to a line perpendicular to the rotational axis is θ ₃ , then θ ₃ = 180° − θ ₁ 2 ( The indexable drill according to any one of claims (1) to (3) of the utility model registration, characterized in that the drill is arranged so that α=0 to 8°). (5) Each of the above-mentioned throw-away tips is placed in a position that satisfies the following conditions on the cutting edge inside the point P, where a is the projected length of the cutting edge on the outer circumferential side of the above point P. A throw-away drill according to any one of claims (1) to (4) of the utility model registration claim, characterized in that the drill has the following features: Projection length b from point P to Nik installation point b = 0.2
5a to 0.75a. The trajectories of the chips on each chip do not overlap. (6) Utility model registration claims 1 to 1, characterized in that the axial distance from the outer end of the cutting blade of the center drill to the point P is set to l = 0 to 1 mm. Throw-away drill described in any of paragraph (5).