JPH0569214A - Drilling tool - Google Patents
Drilling toolInfo
- Publication number
- JPH0569214A JPH0569214A JP13307891A JP13307891A JPH0569214A JP H0569214 A JPH0569214 A JP H0569214A JP 13307891 A JP13307891 A JP 13307891A JP 13307891 A JP13307891 A JP 13307891A JP H0569214 A JPH0569214 A JP H0569214A
- Authority
- JP
- Japan
- Prior art keywords
- tool
- cutting edge
- tip
- cutting
- outer peripheral
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】この発明は、例えば炭素繊維強化
プラスチックなどの樹脂、グラファイトあるいは軽合金
などに穴あけ加工を行う際に用いて好適な穴あけ工具に
関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drilling tool suitable for drilling a resin such as carbon fiber reinforced plastic, graphite or a light alloy.
【０００２】[0002]
【従来の技術】被削材の穴あけ加工に用いる切削工具と
して、従来より工具本体の外周部に形成された２条のね
じれ溝の先端に切刃が形成されてなる２枚刃のツイスト
ドリルが知られている。しかしながら、このようなドリ
ルでは切刃の先端角が１１８゜の鈍角に設定されること
が多いため、貫通孔を形成する場合の抜けぎわに、ワー
クの残された部分が切刃のチゼル部で押し広げられてバ
リやコバ欠けを招くことがあり、特に炭素繊維強化プラ
スチックなどの樹脂材料やグラファイト、軽合金等の穴
あけ加工を行う際にその傾向が顕著であった。また、こ
れらのドリルの多くは工具鋼を材質としているため、切
刃の摩耗が激しくて寿命が早期に尽きがちでもある。2. Description of the Related Art As a cutting tool used for boring a work material, a two-flute twist drill having a cutting edge formed at the tip of two helical grooves formed on the outer periphery of a tool body has been conventionally used. Are known. However, with such a drill, the tip angle of the cutting edge is often set to an obtuse angle of 118 °, and therefore the remaining part of the work is pushed by the chisel part of the cutting edge when the through hole is formed. There is a case where it is spread and may cause burrs and edge chipping, and this tendency is particularly noticeable when drilling holes in resin materials such as carbon fiber reinforced plastics, graphite, and light alloys. Further, since most of these drills are made of tool steel, their cutting edges are often worn out and their service lives tend to be exhausted early.
【０００３】そこで、このような欠点の解消を図った穴
あけ工具として、特開昭６３−２４５３１２号公報に記
載されたドリルが提案されている。このドリルは、図５
〜図１０に示すように、軸状の工具本体１の外周部に一
対の切欠面２・２が形成され、これら切欠面２によって
工具本体１の先端部が先端に向かうほど薄くなる楔状に
形成され、この工具本体１の先端面１ａが先端角（＝
θ）３０゜〜４０゜ の矢じり状に形成され、この先端面
１ａに一定厚さの超高圧焼結体３が当該先端面１ａに沿
ってろう付け接合され、これら超高圧焼結体３の工具回
転方向を向く稜線に切刃４・４が形成されてなるもの
で、上記超高圧焼結体３の表面は切刃４から離間するに
従って工具軸線方向後端側へ次第に大きく傾斜せしめら
れて切刃４の逃げ面５・５とされている。Therefore, a drill disclosed in Japanese Patent Application Laid-Open No. 63-245312 has been proposed as a drilling tool for solving such a drawback. This drill is
As shown in FIG. 10, a pair of cutout surfaces 2 and 2 are formed on the outer peripheral portion of the shaft-shaped tool body 1, and the cutout surface 2 forms the tip of the tool body 1 in a wedge shape that becomes thinner toward the tip. The tip surface 1a of the tool body 1 has a tip angle (=
θ) formed in the shape of an arrowhead of 30 ° to 40 °, and an ultra-high pressure sintered body 3 having a constant thickness is brazed and joined to the tip surface 1 a of the ultra high pressure sintered body 3. A cutting edge 4 is formed on a ridge line that faces the tool rotation direction, and the surface of the above-mentioned ultra-high pressure sintered body 3 is gradually inclined toward the rear end side in the axial direction of the tool as the distance from the cutting edge 4 increases. It is the flank surface 5 of the cutting edge 4.
【０００４】そして、このようなドリルによれば、切刃
４の先端角が従来に比して遥かに小さい角度に設定され
ているため、切刃４によるワークの押し広げ作用が低減
され、バリ等の発生が抑制される。また、切刃４及びそ
の逃げ面５が超高圧焼結体３で構成されているので摩耗
防止効果も得られる。According to such a drill, since the tip angle of the cutting edge 4 is set to a much smaller angle than in the conventional case, the work of spreading the work by the cutting edge 4 is reduced and the burr is reduced. And the like are suppressed. Further, since the cutting edge 4 and the flank 5 thereof are made of the ultra-high pressure sintered body 3, a wear preventing effect can be obtained.
【０００５】[0005]
【発明が解決しようとする課題】ところで、上述した従
来の図５〜図１０に示すドリルでは、切刃先端角が切刃
の全長に渡って一様な鋭角に形成されているため、切刃
４の外周部におけるワークの押し広げ作用自体は緩和さ
れるものの、切刃４の中心側の切削作用が変化するため
にかえってバリ等の発生が激化することがあった。すな
わち、ドリルの先端角の大小はドリルの押し込み力に大
きく影響し、先端角が小さいほど押し込み力も小さくて
足りることになる。このことは、上記ドリルのように先
端角が鋭角とされたドリルにとって、僅かな押し込み力
を与えるだけでもドリルが軸線方向へ大きく進むことを
意味し、この場合の切刃先端での切削作用はワークを削
り取るというよりはむしろワークを突き破る状態に近く
なる。従って、特に樹脂材料等を切削する場合には、ド
リルの押し進め力によって切刃先端部がワークに急激に
食い付いてワークを一気に突き破ってしまうことがあ
り、ワークに大きなかえりが生じて最終的にバリが残っ
てしまうのである。By the way, in the above-described conventional drill shown in FIGS. 5 to 10, since the cutting edge tip angle is formed to be a uniform acute angle over the entire length of the cutting edge, the cutting edge is formed. Although the work of pushing out and spreading the work in the outer peripheral portion of 4 was relaxed, the cutting action on the center side of the cutting edge 4 was changed, and the occurrence of burrs or the like was sometimes intensified. That is, the size of the tip angle of the drill greatly affects the pushing force of the drill, and the smaller the tip angle, the smaller the pushing force is sufficient. This means that for a drill whose tip angle is an acute angle like the above-mentioned drill, even if a slight pushing force is applied, the drill greatly advances in the axial direction, and the cutting action at the tip of the cutting edge in this case is Rather than scraping the work, it is closer to breaking through the work. Therefore, especially when cutting a resin material, the tip of the cutting edge may abruptly hit the work piece by the pushing force of the drill and break through the work piece at once, resulting in a large burr on the work piece and finally The burr remains.
【０００６】また、上述したドリルでは、切刃先端角が
鋭角なため切刃４が工具軸線方向に長尺化する。このた
め切刃４の軸方向送り速度を緩やかに設定して急激な押
し込みを防止した場合、切刃先端がワークに食いついた
後、切刃４の後端がワークを完全に貫通するまでに長時
間を必要とし、加工時間の増加が避けられないという欠
点が生じる。Further, in the above-mentioned drill, since the cutting edge tip angle is acute, the cutting edge 4 becomes elongated in the tool axis direction. For this reason, if the axial feed rate of the cutting edge 4 is set gently to prevent a sudden indentation, it will take a long time until the rear edge of the cutting edge 4 completely penetrates the work after the cutting edge tip bites the work. The disadvantage is that it requires time and an increase in processing time is unavoidable.
【０００７】しかも、上記ドリルでは、その切刃の先端
が鋭く尖っているので強度の確保が困難で、切刃の欠け
が生じ易くて工具寿命が損なわれがちであるという欠点
もあった。Moreover, in the above-mentioned drill, since the tip of the cutting edge is sharply pointed, it is difficult to secure the strength, and the cutting edge is apt to be chipped and the tool life tends to be impaired.
【０００８】この発明は、このような背景の下になされ
たもので、ワークの抜けぎわでのバリやコバ欠けの発生
を防止しつつ加工時間の長時間化を回避できる穴あけ工
具を提供することを目的とする。The present invention has been made under such a background, and provides a drilling tool capable of preventing the occurrence of burrs and chippings at the edges of a workpiece while avoiding a long machining time. With the goal.
【０００９】[0009]
【課題を解決するための手段】上記課題を解決するため
にこの発明の穴あけ工具は、切刃の先端角が、当該切刃
の内周端から外周端に至る間に少なくとも一段小さくな
る方向へ不連続に変化しているものである。ここで、切
刃の耐摩耗性を向上させるには、工具本体の先端部に超
高圧焼結体を接合し、この超高圧焼結体上に上記切刃を
形成することが効果的である。また、上記切刃の先端角
の変化の程度は必要に応じて適宜定めて良いが、切刃の
外周端から工具径方向中心側へ向かって工具径の３０％
以上の範囲の切刃先端角を２０゜ 〜４５゜ に、工具中心
から工具外周側へ向かって工具径の３０％以上の範囲の
切刃先端角を５０゜ 〜１２０゜ に設定することにより、
バリ等の発生を防ぎつつ加工時間を効率良く短縮でき
る。さらに、切屑を円滑に排出するには、工具本体に該
工具本体の内部を貫いて一端が工具本体の先端部に開口
し、他端が工具本体の後端面に開口する流路を形成する
ことが効果的である。In order to solve the above problems, the drilling tool of the present invention is such that the tip angle of the cutting edge becomes at least one step smaller between the inner peripheral edge and the outer peripheral edge of the cutting edge. It is changing discontinuously. Here, in order to improve the wear resistance of the cutting edge, it is effective to bond an ultra-high pressure sintered body to the tip of the tool body and form the cutting edge on the ultra-high pressure sintered body. .. The degree of change in the tip angle of the cutting edge may be appropriately determined as necessary, but it is 30% of the tool diameter from the outer peripheral end of the cutting edge toward the tool radial direction center side.
By setting the cutting edge tip angle in the above range to 20 ° to 45 ° and setting the cutting edge tip angle in the range of 30% or more of the tool diameter from the tool center to the tool outer peripheral side to 50 ° to 120 °,
The processing time can be efficiently reduced while preventing the occurrence of burrs and the like. Further, in order to smoothly discharge the chips, a flow path should be formed in the tool body that penetrates the inside of the tool body and has one end opening at the tip of the tool body and the other end opening at the rear end surface of the tool body. Is effective.
【００１０】[0010]
【作用】上記構成によれば、切刃の外周側の先端角が内
周側よりも小さくなるので、切刃の内周側では、切刃先
端角を従来の鋭角よりも大きくすることによって切刃先
端部をワークに対して徐々に食い付かせ、ドリルの押し
進め力による切刃のワーク突き破り作用を抑制できる。
一方、切刃の外周側では先端角を従来の鋭角と同等とし
て切刃の抜けぎわにおける工具径方向への切削進行速度
を緩やかとし、切刃外周部におけるワークの押し広げ作
用を十分に抑制してバリ等の発生を防止できる。加え
て、切刃の内周側の先端角を大きくすることで切刃が工
具軸線方向に占める長さを短縮でき、これにより加工時
間の短縮を図ることができる。また、超高圧焼結体上に
形成された切刃は耐摩耗性に優れるために工具寿命が向
上する。さらに、機械装着時には、工具本体の後端側に
供給される切削油や圧縮空気を流路を介して工具先端部
に供給することで切屑の排出性が改善され、これに伴っ
て切削抵抗が低減されて工具寿命が一層向上する。According to the above construction, the tip angle on the outer peripheral side of the cutting blade is smaller than that on the inner peripheral side. Therefore, on the inner peripheral side of the cutting blade, the cutting edge tip angle is made larger than the conventional acute angle. The tip of the blade gradually bites against the work, and the work-breaking action of the cutting edge due to the pushing force of the drill can be suppressed.
On the other hand, on the outer peripheral side of the cutting edge, the tip angle is made equal to the conventional acute angle so that the cutting progress speed in the radial direction of the tool at the cutting edge of the cutting edge is moderated and the spreading action of the work on the outer peripheral part of the cutting edge is sufficiently suppressed. Burr can be prevented. In addition, by enlarging the tip angle on the inner peripheral side of the cutting edge, the length occupied by the cutting edge in the tool axis direction can be shortened, thereby shortening the machining time. Further, the cutting edge formed on the ultra-high pressure sintered body has excellent wear resistance, so that the tool life is improved. Furthermore, when the machine is installed, the cutting oil and compressed air supplied to the rear end side of the tool body are supplied to the tool tip through the flow path to improve chip discharge performance, which in turn increases cutting resistance. It is reduced and the tool life is further improved.
【００１１】[0011]
【実施例】以下、図１〜図４を参照して、本発明の一実
施例を説明する。まず、図２により本実施例にかかるド
リルの全体構成を説明すると、図示のドリル１０は、軸
状をなす工具本体１１の先端に２枚の切刃１２・１３が
形成されてなるものである。工具本体１１は、図示せぬ
工作機械の工具把持部に装着される円筒状のドライバ１
４と、このドライバ１４の中心孔１４ａに同軸的に嵌合
されたシャンク１５と、このシャンク１５の先端に同軸
的にろう付け固着された超硬合金製の切刃チップ１６と
から概略構成され、工具本体１１の外周部のうち切刃チ
ップ１６からシャンク１５にかけての部分には切刃チッ
プ１６の先端面１６ａ、外周面１６ｂ及びシャンク１５
の外周面１５ａに開口する２本の切屑排出溝１７・１７
が形成されている。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. First, the overall structure of the drill according to the present embodiment will be described with reference to FIG. 2. The illustrated drill 10 has two cutting edges 12 and 13 formed at the tip of a tool body 11 having an axial shape. .. The tool body 11 is a cylindrical driver 1 that is mounted on a tool grip of a machine tool (not shown).
4, a shank 15 coaxially fitted in the central hole 14a of the driver 14, and a cutting edge tip 16 made of cemented carbide and brazed and fixed coaxially to the tip of the shank 15. The tip surface 16a, the outer peripheral surface 16b, and the shank 15 of the cutting blade tip 16 are provided in the outer peripheral portion of the tool body 11 from the cutting blade tip 16 to the shank 15.
Of two chip discharge grooves 17, 17 that open to the outer peripheral surface 15a of the
Are formed.
【００１２】図１及び図３により詳細に示すように、各
切屑排出溝１７は工具軸線と直交する断面視において略
Ｖ字状をなすもので、各溝の壁面１８、１９はいずれも
工具軸線Ｏ（図２、図４参照）とほぼ平行に延びる平坦
面に形成されている。また、切刃チップ１６の外周部に
は工具先端側へ向かうに従って工具中心側へ漸次接近す
る２つの切欠面２０が形成され、これら切欠面２０によ
って切屑排出溝１７の工具回転方向（図３中矢印Ｂ方
向）と反対方向を向く壁面１９は、切刃チップ１６の途
中から先端にかけて大きく切り欠かれている。そして、
図４に示すように、切刃チップ１６の先端部は、上記各
切欠面２０が設けられることによって側面視で楔状に形
成されている。As shown in more detail in FIGS. 1 and 3, each chip discharge groove 17 has a substantially V shape in a sectional view orthogonal to the tool axis, and the wall surfaces 18 and 19 of each groove are both the tool axis. It is formed on a flat surface extending substantially parallel to O (see FIGS. 2 and 4). Further, on the outer peripheral portion of the cutting blade tip 16, two notch surfaces 20 are formed which gradually approach the tool center side as they go toward the tool tip side, and these notch surfaces 20 cause the tool discharge direction of the chip discharge groove 17 (in FIG. 3). The wall surface 19 which faces the direction opposite to the arrow B direction) is largely cut away from the middle of the cutting blade tip 16 to the tip. And
As shown in FIG. 4, the tip portion of the cutting blade tip 16 is formed in a wedge shape in a side view by providing each of the cutout surfaces 20.
【００１３】図１及び図３に示すように、切刃チップ１
６の先端には当該切刃チップ１６を径方向に貫く一定幅
の切刃取付溝２１が形成されている。そして、この切刃
取付溝２１には、２つの切刃体２２、２３が、互いの内
周端部を突き合わせかつ各々の先端を工具先端側へ突出
させた状態で挿入されてろう付け固着されている。ここ
で、各切刃体２２、２３の長さは不等とされている。す
なわち、一方の切刃体２２が切刃チップ１６の外周から
工具径方向に沿って延び、工具回転中心を越えて径方向
反対側に突き出しているのに対して、他方の切刃体２３
はその内周端が一方の切刃体２２の裏面側に突き合わさ
れている。このため、工具軸線方向からの正面視におい
て、各切刃体２２、２３の接合線Ｌは工具回転中心から
離れて他方の切刃体２３の側へ偏っている。As shown in FIGS. 1 and 3, the cutting edge tip 1
A cutting edge mounting groove 21 having a constant width is formed at the tip of 6 to penetrate the cutting edge tip 16 in the radial direction. Then, two cutting blade bodies 22, 23 are inserted into the cutting blade mounting groove 21 with their inner peripheral end portions abutting each other and their tips protruding toward the tool tip side, and are fixed by brazing. ing. Here, the lengths of the cutting blades 22 and 23 are unequal. That is, one cutting edge body 22 extends along the tool radial direction from the outer periphery of the cutting edge tip 16 and projects to the opposite side in the radial direction beyond the tool rotation center, while the other cutting edge body 23.
The inner peripheral end of the blade is abutted against the back surface side of the one cutting blade body 22. Therefore, in a front view from the tool axis direction, the joining line L of each cutting blade body 22 and 23 deviates from the tool rotation center and is biased toward the other cutting blade body 23.
【００１４】切刃体２２、２３は、ダイヤモンドやＣＢ
Ｎ（立方晶窒化硼素）などに代表される超高圧焼結体２
４、２５と、超硬合金製の母材２６、２７とをともに一
定厚さで積層して全体を平板状に成形してなるもので、
母材２６、２７が切刃取付溝２１にろう付けされること
によって切刃チップ１６に強固に固着されている。ここ
で、各切刃体２２、２３の向きは、超高圧焼結体２４、
２５の表面が工具回転方向を向くように定められてい
る。従って、工具正面視（図３）において各切刃体２
２、２３は、接合線Ｌを境としてそれぞれの向きが反転
することとなる。なお、図示の例では超高圧焼結体２
４、２５の厚さが母材２６、２７の厚さよりも幾らか大
きく設定されている。また、工具回転中心Ｐ0は、一方
の切刃体２２の超高圧焼結体２４上に位置している。The cutting blades 22 and 23 are made of diamond or CB.
Ultra-high pressure sintered body 2 represented by N (cubic boron nitride), etc.
4, 25 and base materials 26, 27 made of cemented carbide are laminated with a constant thickness, and the whole is formed into a flat plate shape.
The base materials 26 and 27 are brazed to the cutting edge mounting groove 21 so that they are firmly fixed to the cutting edge tip 16. Here, the orientations of the cutting blades 22 and 23 are as follows:
The surface of 25 is defined so as to face the tool rotation direction. Therefore, when viewed from the front of the tool (Fig. 3), each cutting blade 2
The directions of 2 and 23 are reversed with the joining line L as a boundary. In the illustrated example, the ultra-high pressure sintered body 2
The thicknesses of Nos. 4 and 25 are set to be slightly larger than the thicknesses of the base materials 26 and 27. The tool rotation center P 0 is located on the ultra-high pressure sintered body 24 of the one cutting blade body 22.
【００１５】そして、図１及び図３により詳細に示すよ
うに、超高圧焼結体２４、２５の工具先端側を向く稜線
部には上記切刃１２、１３が形成されている。これら切
刃１２、１３は、工具中心側から外周側へ向かうに従っ
て工具軸線方向後端側へ後退する点で従来のドリルと共
通するものの、切刃先端角が途中の変極点Ｐ1、Ｐ1で小
さくなる方向へ不連続に変化する点で従来と著しく異な
っている。すなわち、切刃１２、１３には、上記変極点
Ｐ1を境として２種類の異なる切刃先端角φ1、φ2が与
えられており、しかも内周側の切刃先端角φ1が外周側
の切刃先端角φ2よりも大きく定められている。As shown in more detail in FIGS. 1 and 3, the cutting edges 12 and 13 are formed on the ridges of the ultra-high pressure sintered bodies 24 and 25 facing the tool tip side. These cutting blades 12 and 13 are common with the conventional drill in that they are retracted to the rear end side in the tool axial direction from the tool center side toward the outer peripheral side, but the cutting edge tip angles are midpoint inflection points P 1 and P 1. It is remarkably different from the conventional one in that it changes discontinuously in the direction of decreasing. That is, the cutting edges 12 and 13 are provided with two different kinds of cutting edge tip angles φ 1 and φ 2 with the inflection point P 1 as a boundary, and moreover, the cutting edge tip angle φ 1 on the inner circumference side is the outer circumference. It is set to be larger than the cutting edge tip angle φ 2 on the side.
【００１６】ここで、切刃１２、１３の切刃先端角の値
は被削材の材質や切削速度等の切削条件に応じて適宜定
めて良く、また図示例のように１段階変化させる場合に
限らず２段あるいはそれ以上の多段階に変化させても良
いが、最も工具中心側の切刃先端角（図示例ではφ1に
相当する。）及び最も外周側の切刃先端角（図示例では
φ2に相当する。）については以下の範囲とすることが
好ましい。Here, the values of the cutting edge angles of the cutting edges 12 and 13 may be appropriately determined according to the cutting conditions such as the material of the work material and the cutting speed, and in the case of changing one step as in the illustrated example. However, the cutting edge tip angle on the most tool center side (corresponding to φ 1 in the illustrated example) and the cutting edge tip angle on the outermost side (Fig. In the example shown, which corresponds to φ 2 , it is preferable that the following range be satisfied.
【００１７】まず、最も工具中心側の切刃先端角、換言
すれば、複数の切刃先端角のうちで最大となる切刃先端
角については５０〜１２０゜ の範囲が好適であり、しか
もかかる最大先端角を与える範囲は、工具中心から工具
径方向に沿って外周側へ工具径Ｄの３０％以上とするこ
とが好ましい。５０゜ に満たないと切刃先端が鋭利過ぎ
てドリルの押し進め力によるワーク突き破り作用を十分
に抑制できないおそれがあり、他方１２０゜ を越えると
工具回転中心部に作用する切削抵抗が大きくなり過ぎて
ドリルの押し進め力が著しく増加するおそれが生じるか
らである。また、最大先端角を与える範囲を工具径Ｄの
３０％以上とするのは、かかる範囲に満たないと工具中
心部の切刃先端角を５０゜ 以上とした効果を十分に得ら
れないおそれが生じるからである。First, the cutting edge tip angle closest to the tool center, in other words, the maximum cutting edge tip angle among the plurality of cutting edge tip angles, is preferably in the range of 50 to 120 °. The range in which the maximum tip angle is given is preferably 30% or more of the tool diameter D from the tool center to the outer peripheral side along the tool radial direction. If the angle is less than 50 °, the tip of the cutting edge may be too sharp and the work breaking through action due to the pushing force of the drill may not be sufficiently suppressed. On the other hand, if it exceeds 120 °, the cutting resistance acting on the tool rotation center may become too large. This is because the pushing force of the drill may increase significantly. Further, if the range of giving the maximum tip angle is 30% or more of the tool diameter D, the effect of setting the tip angle of the cutting edge at the tool center portion to 50 ° or more may not be sufficiently obtained unless the range is less than this range. Because it will occur.
【００１８】一方、最も工具外周側の切刃先端角、換言
すれば、複数の切刃先端角のうちで最小となる切刃先端
角については２０〜４５゜ の範囲が好適であり、しかも
かかる最小先端角を与える範囲は、切刃の外周端から工
具径方向に沿って中心側へ工具径Ｄの３０％以上とする
ことが好ましい。４５゜ を越えると切刃外周部のワーク
押し広げ作用が大きくなってバリ等の発生を十分抑制で
きないおそれがあり、他方２０゜ に満たないと切刃外周
部の軸方向長さが過度に増加するおそれが生じるからで
ある。また、最小先端角を与える範囲を工具径Ｄの３０
％以上とするのは、かかる範囲に満たないと工具外周部
の切刃先端角を４５゜ 以下としたことによる効果を十分
に得られないおそれが生じるからである。On the other hand, the cutting edge tip angle on the outermost side of the tool, in other words, the minimum cutting edge tip angle among the plurality of cutting edge tip angles, is preferably in the range of 20 to 45 °, The range of giving the minimum tip angle is preferably 30% or more of the tool diameter D from the outer peripheral end of the cutting edge toward the center along the tool radial direction. If it exceeds 45 °, the work spreading effect on the outer peripheral part of the cutting edge may become large and the occurrence of burrs may not be sufficiently suppressed. On the other hand, if it is less than 20 °, the axial length of the outer peripheral part of the cutting edge increases excessively. This is because there is a risk that Also, the range that gives the minimum tip angle is 30 for the tool diameter D.
The reason for setting it to be at least% is that if it is less than this range, the effect due to the cutting edge tip angle of the outer peripheral portion of the tool being 45 ° or less may not be sufficiently obtained.
【００１９】また、図１〜図３に示すように、工具本体
１１の内部には流路２８が設けられている。この流路２
８は、当該ドリル１０を工作機械に装着した際にドライ
バ１４の後端面１４ｂに供給される切削油や圧縮空気を
工具先端側へ導くためのもので、上記ドライバ１４の中
心孔１４ａ、シャンク１５の中心孔１５ｂ及び切刃チッ
プ１６内の排出路１６ｃによって構成されている。そし
て排出路１６ｃは、切刃の数に合わせて２本形成され、
それぞれが切刃チップ１６の切欠面２０に開口せしめら
れている。Further, as shown in FIGS. 1 to 3, a flow path 28 is provided inside the tool body 11. This channel 2
Reference numeral 8 is for guiding cutting oil and compressed air supplied to the rear end surface 14b of the driver 14 to the tool tip side when the drill 10 is mounted on a machine tool. The center hole 14a of the driver 14 and the shank 15 are provided. Is formed by the central hole 15b and the discharge path 16c in the cutting edge tip 16. And two discharge paths 16c are formed according to the number of cutting edges,
Each is opened in the notch surface 20 of the cutting blade tip 16.
【００２０】次に、以上のように構成されたドリル１０
の作用を説明する。本実施例のドリル１０でワーク（図
示略）の穴あけ加工を行うには、工具本体１１のドライ
バ１４を工作機械の工具把持部に装着した後、ドライバ
１４の後端面から流路２８の内部へ切削油または圧縮空
気を供給し、さらには工具本体１１を軸線回りに回転さ
せつつ軸線方向先端側へ送りだして切刃１２、１３でワ
ークを穿孔してゆく。Next, the drill 10 constructed as described above.
The action of will be explained. In order to perform drilling of a work (not shown) with the drill 10 of the present embodiment, after the driver 14 of the tool body 11 is mounted on the tool gripping part of the machine tool, the rear end surface of the driver 14 is moved into the flow path 28. Cutting oil or compressed air is supplied, and further, the tool body 11 is rotated around the axis and is sent to the tip side in the axial direction, and the work is perforated by the cutting blades 12 and 13.
【００２１】ここで、本実施例のドリル１０では、切刃
１２、１３の先端角が中心部と外周部とで異なるため、
中心側の先端角φ1を図５に示す従来の鋭利なドリルよ
りも十分に大きく設定することにより、切刃１２、１３
をワークに対して徐々に食い付かせ、ドリルの押し進め
力によるワークの突き破り作用を抑制してバリ等の原因
となるかえりの発生を防止できる。一方、切刃外周側の
先端角φ2を従来のドリルとほぼ同程度の鋭角に設定す
ることで切刃外周部のワーク押し広げ作用を抑制してバ
リ等の発生を防ぐことができ、以上より切刃中心部及び
外周部でのバリ、コバ欠け等の発生原因を共に排除して
高品質な穴あけ加工を行うことができる。しかも、切刃
中心側の先端角φ1を図５に示す従来例よりも大きくす
ることで、これに応じて切刃１２、１３が軸方向に占め
る長さを短縮でき、これにより加工時間の短縮をも実現
できる。加えて、切刃中心部の先端角を従来よりも大き
くできるので切刃強度の向上をも図ることができる。Here, in the drill 10 of this embodiment, since the tip angles of the cutting edges 12 and 13 are different between the central portion and the outer peripheral portion,
By setting the tip angle φ 1 on the center side to be sufficiently larger than that of the conventional sharp drill shown in FIG.
It is possible to prevent the occurrence of burr which may cause burrs, etc., by making the workpiece gradually bite against the work and suppressing the work breaking through action due to the pushing force of the drill. On the other hand, by setting the tip angle φ 2 on the outer peripheral side of the cutting edge to an acute angle that is almost the same as that of a conventional drill, it is possible to suppress the work spreading action of the outer peripheral part of the cutting edge and prevent the occurrence of burrs, etc. Further, it is possible to perform high-quality drilling by eliminating both the causes of burrs, chipping of edges, etc. in the central portion and outer peripheral portion of the cutting edge. Moreover, by making the tip angle φ 1 on the center side of the cutting edge larger than that of the conventional example shown in FIG. 5, the length occupied by the cutting edges 12 and 13 in the axial direction can be correspondingly shortened, thereby reducing the machining time. It can also be shortened. In addition, since the tip angle of the central portion of the cutting edge can be made larger than in the conventional case, the strength of the cutting edge can be improved.
【００２２】さらに、切刃１２、１３自体が超高圧焼結
体２４、２５上に形成されているから耐摩耗性も高く、
しかも超高圧焼結体２４、２５を切刃１２、１３のすく
い面となる壁面１８に沿って取り付けているので再研削
を行っても依然として超高圧焼結体２４、２５上に切刃
を設けることができ、また超高圧焼結体２４、２５の使
用量も工具先端面全域を覆う従来例より少なくできる。Furthermore, since the cutting edges 12 and 13 themselves are formed on the ultra-high pressure sintered bodies 24 and 25, the wear resistance is high,
Moreover, since the ultra-high pressure sintered bodies 24 and 25 are attached along the wall surface 18 that is the rake face of the cutting edges 12 and 13, even if re-grinding is performed, the cutting edges are still provided on the ultra-high pressure sintered bodies 24 and 25. Further, the amount of the ultra-high pressure sintered bodies 24, 25 used can be reduced as compared with the conventional example which covers the entire tool tip surface.
【００２３】加えて、工具本体１１に切屑排出溝１７を
形成しているので切屑の排出性が改善され、この点特に
流路２８から切欠面２０に切削油や圧縮空気を吐出させ
た場合には、切削油や空気が切屑排出溝１７を工具後端
側へ向けて流れることによって切屑が強制的に排出され
るので切屑排出性が大幅に向上し、その分切削抵抗が減
少して工具寿命が一層向上する。In addition, since the chip discharging groove 17 is formed in the tool body 11, the chip discharging property is improved. In this respect, particularly when cutting oil or compressed air is discharged from the flow path 28 to the cut surface 20. Is forcibly discharged as the cutting oil or air flows toward the tool rear end side through the chip discharge groove 17, so that the chip discharge performance is greatly improved, and the cutting resistance is reduced correspondingly to reduce the tool life. Is further improved.
【００２４】なお、本実施例では特に２枚の切刃１２、
１３を有するドリルを例にあげて説明したが、本発明は
これに限るものではなく、１枚または３枚以上に適宜変
更され得ること勿論である。また、工具本体１１の構成
もあくまで例示に過ぎず、必要に応じて適宜設計変更さ
れるものである。In this embodiment, two cutting blades 12,
Although the drill having 13 has been described as an example, the present invention is not limited to this, and it is needless to say that the number can be appropriately changed to one or three or more. Further, the configuration of the tool body 11 is merely an example, and the design may be changed as needed.
【００２５】[0025]
【発明の効果】以上説明したように、この発明の穴あけ
工具によれば、切刃の先端角を内周側よりも外周側が小
さくなるように不連続に変化させたため、内周側すなわ
ち工具中心部の切刃先端角を従来の鋭利なドリルよりも
大きく設定する一方で、切刃外周端側の切刃先端角を従
来のドリルと同等の鋭角に設定することにより、切刃中
心部のワークへの食い付きを徐々に進行させてかえりの
発生を防止するとともに、切刃外周部をワークから徐々
に抜けさせてワーク抜けぎわにおけるワーク押し広げ作
用を抑制し、バリ、コバ欠けの発生を確実に排除するこ
とができる。しかも、切刃中心部の切刃先端角を外周側
よりも大きく設定することで全体を一様な鋭角に設定す
る従来例に比して切刃の軸線方向に占める長さを短縮し
て加工時間の短縮をも図ることができる。また、切刃中
心部の先端角が従来よりも大きくなるのでその分強度が
向上して工具寿命の延長を図り得る。さらに、超高圧焼
結体上に切刃を形成した場合には切刃の耐摩耗性も確保
されて工具寿命の向上に一層効果があり、これに加えて
流路から工具先端に切削油等を供給すれば切屑排出性が
改善されて切削抵抗も低減され、工具寿命のより一層の
向上を図ることができる。As described above, according to the drilling tool of the present invention, since the tip angle of the cutting edge is discontinuously changed so that the outer peripheral side is smaller than the inner peripheral side, the inner peripheral side, that is, the tool center. The cutting edge tip angle of the cutting edge is set to be larger than that of a conventional sharp drill, while the cutting edge tip angle on the outer peripheral edge side of the cutting edge is set to an acute angle equivalent to that of a conventional drill, so that the workpiece at the cutting edge center The bite is gradually advanced to prevent the occurrence of burrs, and the outer peripheral part of the cutting edge is gradually removed from the work to suppress the work spreading action at the work crevice, ensuring the occurrence of burrs and edge chips. Can be excluded. Moreover, the length of the cutting edge in the axial direction is shortened compared with the conventional example in which the entire cutting edge is set to a uniform acute angle by setting the cutting edge tip angle at the center of the cutting edge to be larger than the outer peripheral side. The time can also be shortened. Further, since the tip angle of the central portion of the cutting edge becomes larger than that of the conventional one, the strength is improved accordingly and the tool life can be extended. Furthermore, when the cutting edge is formed on the ultra-high pressure sintered body, the wear resistance of the cutting edge is secured and it is more effective in improving the tool life. In addition to this, cutting oil from the flow path to the tool tip By supplying, the chip discharging property is improved and the cutting resistance is also reduced, so that the tool life can be further improved.
【図１】本発明の一実施例におけるドリル先端部の拡大
図である。FIG. 1 is an enlarged view of a drill tip portion according to an embodiment of the present invention.
【図２】図１に示すドリルの全体構成を示す側面図であ
る。FIG. 2 is a side view showing the overall configuration of the drill shown in FIG.
【図３】図１のIII方向からの矢視図である。FIG. 3 is a view from the direction of the arrow III in FIG.
【図４】図１にIV方向からの矢視図である。FIG. 4 is a view from the IV direction in FIG.
【図５】従来のドリルの側面図である。FIG. 5 is a side view of a conventional drill.
【図６】図５のVI方向からの矢視図である。FIG. 6 is a view from the direction of arrow VI in FIG.
【図７】図５のVII方向からの矢視図である。7 is a view from the direction of the arrow VII in FIG.
【図８】図５に示すドリルの先端部の拡大図である。8 is an enlarged view of the tip portion of the drill shown in FIG.
【図９】図５のIX方向からの矢視図である。9 is a view from the direction of the arrow IX in FIG.
【図１０】図９のＸ−Ｘ線における断面図である。10 is a cross-sectional view taken along line XX of FIG.
１０ ドリル １１ 工具本体 １２，１３ 切刃 １７ 切屑排出溝 ２４，２５ 超高圧焼結体 ２８ 流路 Ｏ 工具軸線 φ1、φ2 切刃先端角10 Drill 11 Tool Body 12, 13 Cutting Edge 17 Chip Discharge Groove 24, 25 Super High Pressure Sintered Body 28 Flow Path O Tool Axis φ 1 , φ 2 Cutting Edge Tip Angle
───────────────────────────────────────────────────── フロントページの続き (72)発明者 松本 勝則 岐阜県安八郡神戸町大字横井字中新田1528 番地 三菱マテリアル株式会社岐阜製作所 内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsunori Matsumoto 1528, Nakashinda, Yokoi, Kobe-cho, Anpachi-gun, Gifu Prefecture Mitsubishi Materials Corporation Gifu Factory
Claims (4)
から外周側へ向かうにつれて工具軸線方向後端側へ次第
に後退する切刃が設けられてなる穴あけ工具であって、 上記切刃の先端角が、当該切刃の内周端から外周端に至
る間に少なくとも一段小さくなる方向へ不連続に変化し
ていることを特徴とする穴あけ工具。1. A drilling tool, comprising a cutting blade provided at the tip of a tool body in the form of an axis, which gradually recedes toward the rear end side in the tool axis direction from the tool center side toward the outer circumference side. A drilling tool, wherein the tip angle is discontinuously changed in a direction in which it decreases by at least one step between the inner peripheral edge and the outer peripheral edge of the cutting blade.
接合され、この超高圧焼結体上に上記切刃が形成されて
いることを特徴とする請求項１記載の穴あけ工具。2. The drilling tool according to claim 1, wherein an ultra-high pressure sintered body is joined to a tip end portion of the tool body, and the cutting edge is formed on the ultra-high pressure sintered body.
へ向かって工具径の３０％以上の範囲の切刃先端角が２
０゜ 〜４５゜ に、工具中心から工具外周側へ向かって工
具径の３０％以上の範囲の切刃先端角が５０゜ 〜１２０
゜ に設定されていることを特徴とする請求項１又は請求
項２に記載の穴あけ工具。3. The cutting edge tip angle in the range of 30% or more of the tool diameter from the outer peripheral edge of the cutting edge toward the center in the tool radial direction is 2
From 0 ° to 45 °, the cutting edge tip angle in the range of 30% or more of the tool diameter from the tool center to the outer peripheral side of the tool is 50 ° to 120 °.
The drilling tool according to claim 1 or 2, characterized in that the drilling tool is set at a degree.
て一端が上記工具本体の先端部に開口し、他端が工具本
体の後端面に開口する流路が形成されていることを特徴
とする請求項１〜請求項３のいずれか一に記載の穴あけ
工具。4. A flow path is formed in the tool main body, the flow path penetrating the inside of the tool main body and having one end opening to a tip end portion of the tool main body and the other end opening to a rear end surface of the tool main body. The drilling tool according to any one of claims 1 to 3.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13307891A JPH0569214A (en) | 1991-06-04 | 1991-06-04 | Drilling tool |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13307891A JPH0569214A (en) | 1991-06-04 | 1991-06-04 | Drilling tool |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0569214A true JPH0569214A (en) | 1993-03-23 |
Family
ID=15096336
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13307891A Withdrawn JPH0569214A (en) | 1991-06-04 | 1991-06-04 | Drilling tool |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0569214A (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009172708A (en) * | 2008-01-23 | 2009-08-06 | Sumitomo Electric Ind Ltd | Drilling tool and drilling method for fiber-reinforced composite material |
| JP2010201551A (en) * | 2009-03-03 | 2010-09-16 | Osg Corp | Carbide drill with fluid supply hole |
| JP2010284783A (en) * | 2009-06-15 | 2010-12-24 | Osg Corp | Triple angle type drill |
| JP2012223882A (en) * | 2012-08-16 | 2012-11-15 | Sumitomo Electric Ind Ltd | Drilling tool and drilling method of fiber-reinforced composite material |
| JPWO2012091085A1 (en) * | 2010-12-28 | 2014-06-05 | トヨタ自動車株式会社 | drill |
| GB2491956B (en) * | 2011-06-13 | 2015-08-12 | Element Six Ltd | Twist drill tips, precursor constructions for use in making same, and methods for making and using same |
| JP2015221467A (en) * | 2014-05-22 | 2015-12-10 | 富士重工業株式会社 | Drill and manufacturing method of the same |
| JP2016179543A (en) * | 2016-07-22 | 2016-10-13 | 富士重工業株式会社 | Drill and manufacturing method of drill |
| US10589364B2 (en) * | 2016-06-22 | 2020-03-17 | Toko Co., Ltd. | Drill |
-
1991
- 1991-06-04 JP JP13307891A patent/JPH0569214A/en not_active Withdrawn
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009172708A (en) * | 2008-01-23 | 2009-08-06 | Sumitomo Electric Ind Ltd | Drilling tool and drilling method for fiber-reinforced composite material |
| JP2010201551A (en) * | 2009-03-03 | 2010-09-16 | Osg Corp | Carbide drill with fluid supply hole |
| JP2010284783A (en) * | 2009-06-15 | 2010-12-24 | Osg Corp | Triple angle type drill |
| JPWO2012091085A1 (en) * | 2010-12-28 | 2014-06-05 | トヨタ自動車株式会社 | drill |
| JP5708944B2 (en) * | 2010-12-28 | 2015-04-30 | トヨタ自動車株式会社 | drill |
| US9238272B2 (en) | 2010-12-28 | 2016-01-19 | Toyota Jidosha Kabushiki Kaisha | Drill |
| GB2491956B (en) * | 2011-06-13 | 2015-08-12 | Element Six Ltd | Twist drill tips, precursor constructions for use in making same, and methods for making and using same |
| JP2012223882A (en) * | 2012-08-16 | 2012-11-15 | Sumitomo Electric Ind Ltd | Drilling tool and drilling method of fiber-reinforced composite material |
| JP2015221467A (en) * | 2014-05-22 | 2015-12-10 | 富士重工業株式会社 | Drill and manufacturing method of the same |
| US9827617B2 (en) | 2014-05-22 | 2017-11-28 | Subaru Corporation | Drill and method of manufacturing drill |
| US10589364B2 (en) * | 2016-06-22 | 2020-03-17 | Toko Co., Ltd. | Drill |
| JP2016179543A (en) * | 2016-07-22 | 2016-10-13 | 富士重工業株式会社 | Drill and manufacturing method of drill |
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