JPS58146613U - Drill - Google Patents

Abstract

(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

【図面の簡単な説明】[Brief explanation of drawings]

第１図および第２図は従来のドリルの一例を示し、第１
図はその一部省略正面図、第２図はその底面視図、第３
図は従来のドリルの他の例を示す底面視図、第４図は第
１図および第２図のドリルの食い付き時における一部省
略拡大正面図、第５図は第３図のドリルの第４図と同様
の図、第６図はこの考案の一実施例を示す底面視図、第
７図はこの考案の他の実施例を示す底面視図、第８図お
よび第９図はそれぞれこの考案のさらに他の実施例の底
面視図における回転中心部の拡大図である。 １・・・・・・工具本体、２・・・・・・切刃チップ、
６・・・・・・内端縁、１１・・・・・・切刃、１３・
・・・・・直線部、１４・・・・・・外端縁、１５．１
６・・・・・・直線部、０・・・・・・回転中心、ｌ工
・・・・・・直線。 第４図 第５図−Figures 1 and 2 show an example of a conventional drill.
The figure is a partially omitted front view, Figure 2 is a bottom view, and Figure 3 is a partially omitted front view.
The figure is a bottom view showing another example of a conventional drill, FIG. 4 is a partially omitted enlarged front view of the drill shown in FIGS. 1 and 2 when biting, and FIG. 6 is a bottom view showing one embodiment of this invention; FIG. 7 is a bottom view showing another embodiment of this invention; FIGS. 8 and 9 are respectively It is an enlarged view of the center of rotation in a bottom view of still another embodiment of this invention. 1... Tool body, 2... Cutting tip,
6... Inner edge, 11... Cutting edge, 13.
...Straight line part, 14...Outer edge, 15.1
6...Straight line, 0...Rotation center, l-work...Straight line. Figure 4 Figure 5-

Claims (1)

【実用新案登録請求の範囲】[Scope of utility model registration request] 工具本体の先端部に切刃を有し、この切刃の実際に切削
に関与する部分の内端縁を工具本体の回転中心から回転
中心部にコアが生成し始める値より小さい距離だけ離し
て設けたドリルにおいて、前記切刃は底面視において切
刃の内端縁と外端縁とを結ぶ直線に対して回転方向に向
かって膨出するように形成されており、前記切刃の内端
縁と外端縁との間の内周部には少なくとも１つの直線部
があり、この直線部とこれに隣接する部分とを回転方向
に膨出するように湾曲させて滑らかに連結したことを特
徴とするドリル。The tool body has a cutting edge at its tip, and the inner edge of the part of the cutting edge that is actually involved in cutting is separated from the rotation center of the tool body by a distance smaller than the value at which a core begins to form at the rotation center. In the provided drill, the cutting edge is formed to bulge in the rotation direction with respect to a straight line connecting the inner end edge and the outer end edge of the cutting edge when viewed from the bottom, and the inner end of the cutting edge There is at least one straight part in the inner peripheral part between the edge and the outer edge, and this straight part and the part adjacent to this are curved so as to bulge in the rotational direction and are smoothly connected. Featured drill.