JPH0620655B2 - Drill - Google Patents
DrillInfo
- Publication number
- JPH0620655B2 JPH0620655B2 JP15311987A JP15311987A JPH0620655B2 JP H0620655 B2 JPH0620655 B2 JP H0620655B2 JP 15311987 A JP15311987 A JP 15311987A JP 15311987 A JP15311987 A JP 15311987A JP H0620655 B2 JPH0620655 B2 JP H0620655B2
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- JP
- Japan
- Prior art keywords
- drill
- cutting edge
- groove
- sub
- chisel blade
- 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.)
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Description
【発明の詳細な説明】 技術分野 本発明は、ドリルに関し、特に、副溝を備えたドリルに
関する。Description: TECHNICAL FIELD The present invention relates to a drill, and more particularly to a drill having a sub groove.
従来技術 従来、ドリルによる穴明け加工において、穴精度、すな
わち、穴の拡大しろ、穴のピッチ精度、穴の面粗さ等、
を改善するための方策がいろいろ提案されている。例え
ば、チゼル部の改善がその一法である。第４図におい
て、普通のドリル３０は、一般的に、チゼル刃３５が長
く、これによる問題、例えば、ドリルの食付き性が悪
い、歩行現象が出る、あるいは切削抵抗が大きくなる
等、を抱えている。これらを解決するために、一般に、
シンニングを行って、切削性の改善が行われてきた。と
ころが、このシンニングは、その加工の巧拙により、か
えってスラスト力を増加させることがある。そのため、
ユーザーで行う再研削時のシンニング加工は、多大な困
難を伴って行われている。これを改善するために、シン
ニングに変わる方法としてドリルの溝３４の底部に副溝
を形成し、もってチゼル刃３５の長さを短くするととも
にチゼル部の切屑の流れをよくして穴加工精度の向上を
図るドリルが提供されている（特公昭６２−５７２７号
公報）。Conventional technology Conventionally, in drilling with a drill, hole accuracy, that is, the margin of hole expansion, hole pitch accuracy, surface roughness of holes, etc.
Various measures have been proposed to improve the above. For example, improving the chisel part is one method. In FIG. 4, the ordinary drill 30 generally has a long chisel blade 35, which causes problems such as poor biting of the drill, a walking phenomenon, or increased cutting resistance. ing. To solve these, in general,
Thinning has been performed to improve the machinability. However, this thinning may rather increase the thrust force due to the skill of the processing. for that reason,
The thinning process at the time of regrinding performed by the user is performed with great difficulty. In order to improve this, as an alternative method to thinning, a sub-groove is formed at the bottom of the groove 34 of the drill, thereby shortening the length of the chisel blade 35 and improving the flow of chips in the chisel portion to improve the drilling accuracy. A drill for improvement is provided (Japanese Patent Publication No. 62-5727).
該ドリル４０は、溝が主溝４４と副溝４３とからなり、
主溝４４により形成される主切刃４１と、該主切刃４１
に連続しかつ副溝４３は対応する二次切刃４２と、該二
次切刃４２に連続するチゼル刃４５とを備えている。そ
して、上記二次切刃４２は、チゼル刃４５の外周端より
主切刃４１へ直線的に連なるよう形成されている。The drill 40 has a groove composed of a main groove 44 and a sub groove 43,
A main cutting edge 41 formed by the main groove 44, and the main cutting edge 41
And the auxiliary groove 43 is provided with a corresponding secondary cutting edge 42 and a chisel blade 45 continuous with the secondary cutting edge 42. The secondary cutting edge 42 is formed so as to linearly extend from the outer peripheral end of the chisel blade 45 to the main cutting edge 41.
ところが、上記ドリル４０は、二次切刃４２とチゼル刃
４５との相互位置関係によって、ドリル穴の精度が大き
く左右される。However, in the drill 40, the precision of the drill hole largely depends on the mutual positional relationship between the secondary cutting blade 42 and the chisel blade 45.
本発明の技術的課題 従って、本発明の解決すべき技術的課題は、副溝によっ
て形成される二次切刃とチゼル刃との相互位置関係を規
定し、シンニングを施さずに精度のよい穴明け加工がで
きるドリルを提供することである。Technical Problem of the Present Invention Therefore, the technical problem to be solved by the present invention is to define the mutual positional relationship between the secondary cutting edge and the chisel blade formed by the sub-groove, and to provide a highly accurate hole without performing thinning. The purpose is to provide a drill that can be worked.
本発明の構成 上記技術的課題を達成するために、本発明は以下の如く
構成した。Structure of the Present Invention In order to achieve the above technical problems, the present invention has the following structure.
すなわち、切り屑排出溝が、主溝と副溝とで構成され、
先端切刃が、先端円錐面と上記主溝の内周面との交線で
形成される主切刃と、上記先端円錐面と上記副溝の内周
面との交線により形成されて上記主切刃に連続する二次
切刃と、該二次切刃に連続するチゼル刃とで構成され、
直径寸法がＤのドリルにおいて、上記二次切刃が、上記
主切刃の副溝側端と上記チゼル刃の副溝側端とを結ぶ直
線から最も離れた位置で実質的に０．０３Ｄだけドリル
のランド部側に位置し、上記チゼル刃との接点から凹湾
曲状に延び、該凹湾曲状の曲がりが該チゼル刃との接点
に近付くほど大きく曲がるように、上記副溝を形成し
た。That is, the chip discharge groove is composed of the main groove and the sub groove,
The tip cutting edge is formed by a line of intersection between the tip conical surface and the inner peripheral surface of the main groove, and a line of intersection between the tip conical surface and the inner peripheral surface of the sub groove. A secondary cutting edge continuous with the main cutting edge, and a chisel blade continuous with the secondary cutting edge,
In a drill having a diameter dimension of D, the secondary cutting edge is substantially 0.03D at a position farthest from a straight line connecting the sub-groove side end of the main cutting edge and the sub-groove side end of the chisel blade. The sub-groove was formed so as to be located on the land side of the drill and extend in a concave curved shape from the contact point with the chisel blade so that the concave curved curve bends as it approaches the contact point with the chisel blade.
作 用 上記構成によれば、二次切刃を形成するための副溝が、
ドリルのランド部側へくい込むように形成されることに
より、チゼル近傍の先端角が小さくなる。つまり、ドリ
ル先端部は、傾斜のきつい山形状に形成されることにな
る。特に、二次切刃がチゼル刃との接点から凹湾曲状に
延び、しかもその凹湾曲状の曲がり具合が、チゼル刃と
の接点側に近付くほど大きく曲がるように湾曲している
ことによって、先端角は該接点上での接線により規定さ
れるので、その先端角は直線状の二次切刃によって規定
される先端角よりも更に小さくすことができる。上記先
端角が小さくなれば、ドリルの被削材への食付きは改善
される。さらに、ドリルが被削材に食付いた場合、ドリ
ルの回転中心を中心に回転すれば、ドリルの歩行現象は
生じないが、しかし、チゼル刃は略フラットな形状であ
るため、上記回転中心の左右何れかのチゼル刃上の点が
回転中心となり、該回転中心回りにドリルが回転するこ
ともある。これが歩行現象と呼ばれるものであり、これ
を防止するには、チゼル刃を出来るだけ短かくする事も
必要である。つまり、本発明の如く、副溝を形成するこ
とによりチゼル刃長さを短かくすることが可能になる。
すなわち、上記構成による副溝が食付き性を向上させる
とともに、歩行現象を効果的に低減せしめることにな
る。また、二次切刃のランド部への食い込み量を、その
最大食い込み位置で大略０．０３Ｄ（Ｄ：ドリル径）と
抑えているので、この二次切刃がシンニングによって得
られるのではなく副溝の形成によって得られるものでは
あっても、実質的にはその食い込みがドリル剛性を低下
させるという虞れは殆どない。Operation According to the above configuration, the auxiliary groove for forming the secondary cutting edge is
By being formed so as to bite into the land portion side of the drill, the tip angle near the chisel becomes smaller. That is, the tip of the drill is formed in the shape of a mountain with a steep slope. In particular, the secondary cutting edge extends in a concave curved shape from the contact point with the chisel blade, and the curved state of the concave curved shape is curved so that it becomes more curved as it gets closer to the contact side with the chisel blade. Since the angle is defined by the tangent line on the contact, the tip angle can be made even smaller than the tip angle defined by the linear secondary cutting edge. The smaller the tip angle, the better the bite of the drill on the work material. Furthermore, when the drill bites into the work material, if you rotate around the center of rotation of the drill, the walking phenomenon of the drill does not occur, but since the chisel blade has a substantially flat shape, A point on the left or right chisel blade may be the center of rotation, and the drill may rotate around the center of rotation. This is called the walking phenomenon, and in order to prevent this, it is also necessary to make the chisel blade as short as possible. That is, the chisel blade length can be shortened by forming the auxiliary groove as in the present invention.
That is, the auxiliary groove having the above structure improves the biting property and effectively reduces the walking phenomenon. Further, since the amount of biting of the secondary cutting edge into the land portion is suppressed to approximately 0.03D (D: drill diameter) at the maximum biting position, this secondary cutting edge is not obtained by thinning, Even if it is obtained by forming the groove, there is substantially no fear that the bite will reduce the drill rigidity.
実施例 以下に、第１〜３図に従って、本発明の一実施例を具体
的に説明する。Embodiment An embodiment of the present invention will be specifically described below with reference to FIGS.
第１図は、ドリルの先端部を示す正面図で、該図におい
て、１０はドリルを示し、該ドリル１０は、主切刃１
a、二次切刃１bおよびチゼル刃３からなる先端切刃１を
有して大略円錐面状に形成された先端面と、それに続い
て軸方向へ螺旋状に延びた切り屑排出溝およびランド部
６とから構成される溝長部(図示せず)、そして、ドリル
を駆動部側に固定するシャンク部(図示せず)とから構成
される。また、上記切り屑排出溝は、主溝５と副溝４と
からなる。該副溝４は、上記主溝５の底部からチゼル刃
３端近傍に、先端切刃１より上記主溝方向沿にシャンク
部側に向かって形成された溝で、略ドリル中心部に向か
って大略断面Ｕ字形状を有する。また、先端切刃１は、
主溝５の内周面と円錐状先端面との交線で形成される主
切刃１aと、副溝４の内周面と円錐状先端面との交線で
形成される二次切刃１bと、さらにチゼル刃３とから構
成されている。そして、該二次切刃１bは、上記主切刃
１aから上記チゼル刃３までを連続して結ぶ切刃とな
る。しかも、上記副溝４は、上記二次切刃１bのエッジ
たる稜線が上記主切刃１aの副溝側端と上記チゼル刃３
の対応副溝側端の各切刃線上の点を結ぶ直線よりもドリ
ル１０のランド部６側に位置するように形成される。FIG. 1 is a front view showing a tip portion of a drill, in which 10 is a drill, and the drill 10 is a main cutting edge 1
a, a tip surface formed into a substantially conical surface having a tip cutting edge 1 including a secondary cutting edge 1b and a chisel blade 3, and subsequently a chip discharge groove and a land extending spirally in the axial direction. It is composed of a long groove portion (not shown) composed of the portion 6 and a shank portion (not shown) for fixing the drill to the driving portion side. The chip discharge groove is composed of the main groove 5 and the sub groove 4. The sub-groove 4 is a groove formed from the bottom of the main groove 5 in the vicinity of the end of the chisel blade 3 toward the shank portion side along the main groove direction from the tip cutting edge 1 and generally toward the center of the drill. It has a substantially U-shaped cross section. In addition, the tip cutting edge 1
A main cutting edge 1a formed by the line of intersection of the inner peripheral surface of the main groove 5 and the conical tip surface, and a secondary cutting edge formed by the line of intersection of the inner peripheral surface of the auxiliary groove 4 and the conical tip surface. 1b and a chisel blade 3 further. Then, the secondary cutting edge 1b becomes a cutting edge that continuously connects the main cutting edge 1a to the chisel blade 3. Moreover, in the sub-groove 4, the ridge line that is the edge of the secondary cutting edge 1b and the edge of the main cutting edge 1a on the side of the sub-groove and the chisel blade 3 are formed.
Is formed so as to be located closer to the land portion 6 side of the drill 10 than the straight line connecting the points on the respective cutting edge lines at the corresponding sub-groove side ends.
上記構成によれば、ドリル１０の切刃は、ドリル中心
部、すなわちチゼル刃３の近傍部における各切刃線、換
言すれば各切刃の稜線、が第２図に示されるように形成
されてなる。なお、該図における二次切刃の形状は、そ
の特徴を分かり易くするために、その曲線状態を誇張し
て描いているが、例えば外径が１０mmのドリルでは、そ
のランド部側への食い込み量は０．３mm程度であり、実
際には肉眼で見ても大略直線と区別がつかないほどの曲
線となる。図において、チゼル刃３（Ｃ−Ｏ−Ｄ線）
は、ドリル１０の円錐状先端部の頂点部(Ｃ′−Ｄ′線)
を形成し、それに連なる二次切刃１b(Ｃ−Ｅ−Ｂ線)
は、Ｃ′−Ｅ′−Ｂ′線となる。即ち、チゼル刃３の副
溝側端のＣ点からＥ点まで、次第に曲がり具合が緩やか
になるような凹湾曲状に延び、Ｅ点からな大略接線方向
へＢ点まで直線状切刃となっている。また主切刃１a(Ｂ
−Ａ線)は、二次切刃１bに続くＢ′−Ａ′線として形成
されている。尚、第１図における仮想直線部１cは、第
２図においてはＢ′−Ｃ′線に相当する。尚、ドリル１
０には、ドリルの径方向中心線に対し、切刃、溝等が左
右各１個づつ形成されており、上記説明は、その一方に
ついて記述している。According to the above configuration, the cutting edge of the drill 10 is formed such that each cutting edge line in the central portion of the drill, that is, the vicinity of the chisel blade 3, in other words, the ridgeline of each cutting edge is formed as shown in FIG. It becomes. The shape of the secondary cutting edge in the figure is exaggerated in the curved state in order to make the characteristics easy to understand. For example, in the case of a drill having an outer diameter of 10 mm, the biting into the land side is performed. The amount is about 0.3 mm, which is actually a curve that is indistinguishable from a substantially straight line even with the naked eye. In the figure, chisel blade 3 (C-O-D line)
Is the apex of the conical tip of the drill 10 (C'-D 'line)
Secondary cutting edge 1b (C-E-B line)
Becomes the C'-E'-B 'line. That is, the chisel blade 3 extends in a concave curve shape from the point C to the point E on the side of the sub-groove so that the bending gradually becomes gentle, and becomes a straight cutting edge from the point E to the point B in a substantially tangential direction. ing. The main cutting edge 1a (B
-A line) is formed as a B'-A 'line following the secondary cutting edge 1b. The virtual straight line portion 1c in FIG. 1 corresponds to the line B'-C 'in FIG. In addition, drill 1
At 0, one cutting edge, one groove, and the like are formed on the left and right sides with respect to the radial center line of the drill, and the above description describes only one of them.
上記説明のように形成された先端部を備えるドリル１０
は、副溝を備えないドリルのチゼル刃(第２図中、Ｘ′
−Ｃ′−Ｄ′−Ｙ′線に相当する刃)より相当短いチゼ
ル刃３を有することになり、ワークピースに対する食付
き性が向上し、歩行現象が発生しにくくなる特性を備え
る。さらに副溝を備えるドリルであって、該副溝が、第
２図中、Ｂ−Ｃ線(図中二点鎖線)のように形成された従
来の副溝付ドリルと、本実施例に係るドリル１０とを比
較すると、後者のドリル１０は、より急傾斜を有する山
形にチゼル刃３の近傍部を形成してなる。このため、副
溝の形成の態様によって、チゼル刃３の近傍部の先端角
は変化するが、特にチゼル刃３の両端から凹湾曲状に延
びる二次切刃１bは、Ｃ′点およびＤ′点における接線
で規定される先端角θが、ただ単に直線状に形成される
二次切刃によって規定される先端角よりもかなり小さく
なる。一般に、ドリル先端角とドリルの被削材への食付
き性とは、先端角が小さい程、食付き性は良好であり、
先端角が大きい程、ドリルは被削材の面上を動きやすい
と言う関係を備えている。A drill 10 having a tip formed as described above.
Is a chisel blade of a drill without a sub-groove (X 'in Fig. 2
Since the chisel blade 3 is considerably shorter than the blade corresponding to the line -C'-D'-Y '), the biting property with respect to the workpiece is improved and the walking phenomenon is less likely to occur. A drill having a sub-groove, which has a conventional sub-groove with the sub-groove formed along the line BC in FIG. 2 (two-dot chain line in the figure), and the present embodiment. When compared with the drill 10, the latter drill 10 is formed by forming the vicinity of the chisel blade 3 in a chevron shape having a steeper slope. For this reason, the tip angle of the vicinity of the chisel blade 3 changes depending on the form of the sub-groove, but especially the secondary cutting blade 1b extending in a concave curve from both ends of the chisel blade 3 has points C'and D '. The tip angle θ defined by the tangent line at the point is considerably smaller than the tip angle defined by the secondary cutting edge formed simply in a straight line. Generally, the smaller the tip angle, the better the bite to the work material of the drill.
The larger the tip angle, the easier the drill moves on the surface of the work material.
従って、副溝を形成する場合、二次切刃１bとチゼル刃
３との相互位置関係が、ドリル穴の精度に深く関係する
ことになり、上述のような構成が穴の精度向上には好適
である。Therefore, when forming the sub-groove, the mutual positional relationship between the secondary cutting edge 1b and the chisel blade 3 is deeply related to the accuracy of the drill hole, and the above configuration is suitable for improving the accuracy of the hole. Is.
以下に、上記実施例に係るドリルの具体例を示す。ここ
で使用したドリルは、ドリル径が１０mmで、刃部に耐摩
耗性向上のためのコーティングが施されたものである。
また、二次切刃が。上記実施例にて説明した通り、チゼ
ル刃の切刃線上かつ副溝側端の点と、主切刃の切刃線上
かつ副溝側端の点とを結ぶ直線よりドリルのランド部側
に位置するよう、副溝を形成されている。具体的には、
二次切刃と主切刃との接点がドリル中心Ｏより半径Ｒ1
＝２．２mm上に位置し、かつ、二次切刃は、上記直線よ
りドリルのランド部側へ最大ｌ1＝０．３mm入り込んだ
切刃上の点を通る大略曲線状の切刃線を有する。上記構
成を備えたドリル、以下第１ドリルと呼ぶ、と、同一の
ドリル径及び同一の刃部コーティングが施され、かつ、
二次切刃が主切刃からチゼル刃に向かって直線状に形成
されたドリル、以下第２ドリルと呼ぶ、とによる下記条
件下の穴明き加工における穴の拡大代を穴明け数ごとに
測定した。その結果は、第３図の通りである。ここで、
穴明け加工の条件は、 切削速度：２５m／min. 送り：０．１５mm／rev. 被削材：Ｓ５０Ｃ(硬度ＨＢ２４０〜２５０) 切削長：２０mm貫通 切削油：水溶性切削油 使用工作機械：マシニングセンター である。Below, the specific example of the drill which concerns on the said Example is shown. The drill used here has a drill diameter of 10 mm, and the blade has a coating for improving wear resistance.
Also, the secondary cutting edge. As described in the above embodiment, the position of the drill part from the straight line connecting the point on the cutting edge line of the chisel blade and the sub-groove side end and the point on the cutting edge line of the main cutting edge and the sub-groove side end The sub-groove is formed so that In particular,
The radius of contact between the secondary cutting edge and the main cutting edge is R 1 from the center O of the drill.
= 2.2 mm above the secondary cutting edge, the secondary cutting edge is a roughly curved cutting edge line passing through the point on the cutting edge that has entered l 1 = 0.3 mm at the maximum from the above straight line to the land side of the drill. Have. A drill having the above configuration, hereinafter referred to as a first drill, has the same drill diameter and the same blade coating, and
A drill in which the secondary cutting edge is formed in a straight line from the main cutting edge toward the chisel blade, hereinafter referred to as the second drill. It was measured. The result is shown in FIG. here,
Drilling conditions are: cutting speed: 25 m / min. Feed: 0.15 mm / rev. Work material: S50C (hardness HB240-250) cutting length: 20 mm penetrating cutting oil: water-soluble cutting oil machine tool: machining center Is.
図中、第１ドリルによる測定結果(実線で示す)は、第２
ドリルによるそれ(破線で示す)より全ての穴明け数にお
いて穴精度上の優位性を示しており、かつ、各穴明け数
毎の穴径の拡大代のバラツキが第２ドリルのそれよりも
少ない結果を示している。In the figure, the measurement result by the first drill (shown by the solid line) is the second
It shows superiority in hole accuracy in all drilling numbers than that of drilling (indicated by broken lines), and there is less variation in the expansion margin of the hole diameter for each drilling number than that of the 2nd drill. The results are shown.
すなわち、副溝を備えるドリルにおいて、副溝の形態が
ドリル穴の精度と深く関係していると言える。すなわ
ち、同一のチゼル刃長さのドリルであってもドリル穴積
度は異なる。つまり、ドリルの食付き性の良否が副溝の
形態と密接に関係している。実験結果から明らかなよう
に、二次切刃とチゼル刃との相互位置関係は、第１ドリ
ルの方が、第２ドリルよりも優れていると判断でき、従
って、穴の精度向上のためには、第１ドリルのそれと同
一に規定することが好ましい。That is, it can be said that in a drill having a sub-groove, the form of the sub-groove is deeply related to the precision of the drill hole. That is, even if the drills have the same chisel blade length, the drill hole stacking degrees are different. That is, the quality of bite of the drill is closely related to the form of the sub groove. As is clear from the experimental results, the mutual positional relationship between the secondary cutting edge and the chisel blade can be judged to be better in the first drill than in the second drill, and therefore in order to improve the accuracy of the hole. Is preferably defined the same as that of the first drill.
本発明の効果 上記構成によれば、チゼル刃の近傍部は、傾斜のきつい
山形状に形成される。従って、ドリル先端部の先端角が
小さくなり、かつ、チゼル刃も短くなるので、切削時、
被切削材に対する食付き性が良くなり、いわゆる歩行現
象が生じにくく、従って、ドリルの回転中心が移動する
のを効果的に防止することができるとともに切削抵抗が
小さくなり切削性が向上する。また、二次切刃のランド
部側への食い込み量をドリル径の０．０３Ｄ倍程度に抑
えているので、この二次切刃が副溝の形成によって得ら
れるものであっても、その食い込み量のためにドリル剛
性が低下するということは殆どない。このように、従来
より採用されている副溝による上記効果が何ら損なわれ
ることなく、しかも、上記副溝に対応する二次切刃のチ
ゼル刃に対する位置関係を本発明の如く規定することに
より、さらに、従来の副溝付ドリル以上の穴の精度が確
保できる。EFFECTS OF THE INVENTION According to the above configuration, the vicinity of the chisel blade is formed in a shape of a steep mountain with a slope. Therefore, the tip angle of the drill tip becomes smaller and the chisel blade also becomes shorter.
The biting property with respect to the material to be cut is improved and the so-called walking phenomenon is unlikely to occur. Therefore, it is possible to effectively prevent the rotation center of the drill from moving, and the cutting resistance is reduced to improve the cutting property. Further, since the amount of biting of the secondary cutting edge to the land side is suppressed to about 0.03D times the drill diameter, even if this secondary cutting edge is obtained by forming the auxiliary groove, the biting Drill stiffness is rarely compromised by volume. In this way, the effect of the sub-groove that has been conventionally adopted is not impaired at all, and moreover, by defining the positional relationship of the secondary cutting edge corresponding to the sub-groove with respect to the chisel blade as in the present invention, Further, it is possible to secure the accuracy of the hole higher than that of the conventional sub-grooved drill.
また、従来、穴の精度に多大の影響を及ぼしている再研
削毎のシンニングの困難も、本発明によるドリルは、シ
ンニングを行わずとも精度の良い穴明け加工を行うこと
ができるので、解消される。すなわち、ドリル先端の切
刃の刃立てを行うだけで十分にドリル加工できる。Further, conventionally, the difficulty of thinning after each re-grinding, which greatly affects the accuracy of the hole, is eliminated because the drill according to the present invention can perform accurate drilling without performing thinning. It That is, drilling can be sufficiently performed only by setting the cutting edge of the drill tip.
第１図は、本発明の一実施例に係るドリルの先端要部正
面図、第２図は上記ドリルの切刃部における切刃線を示
す説明図、第３図は上記ドリルを用いた穴明け加工にお
ける穴径の拡大代を示す棒グラフ、第４図は従来例に係
るドリル先端要部正面図。 １……先端切刃、１ａ……主切刃、１ｂ……二次切刃、
１ｃ……仮想直線、３……チゼル刃、４……副溝、５…
…主溝、６……ランド部、７……マージン部、１０……
ドリル。FIG. 1 is a front view of the main part of the tip of a drill according to an embodiment of the present invention, FIG. 2 is an explanatory view showing a cutting edge line in a cutting edge portion of the drill, and FIG. 3 is a hole using the drill. FIG. 4 is a front view of the main part of the drill tip according to the conventional example, which is a bar graph showing the margin of expansion of the hole diameter in the drilling process. 1 ... Tip cutting edge, 1a ... Main cutting edge, 1b ... Secondary cutting edge,
1c ... virtual straight line, 3 ... chisel blade, 4 ... sub-groove, 5 ...
… Main groove, 6 …… Land, 7 …… Margin, 10 ……
Drill.
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭60−25608（ＪＰ，Ａ) 特開 昭50−64888（ＪＰ，Ａ) ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-60-25608 (JP, A) JP-A-50-64888 (JP, A)
Claims (1)
成され、 先端切刃が、先端円錐面と上記主溝(5)の内周面との交
線で形成される主切刃(1a)と、上記先端円錐面と上記副
溝(4)の内周面との交線により形成されて上記主切刃(1
a)に連続する二次切刃(1b)と、該二次切刃(1b)に連続す
るチゼル刃(3)とで構成され、 直径寸法がＤのドリル(10)において、 上記二次切刃(1b)が、上記主切刃(1a)の副溝側端と上記
チゼル刃(3)の副溝側端とを結ぶ直線から最も離れた位
置で実質的に０．０３Ｄだけドリル(10)のランド部(6)
側に位置し、上記チゼル刃(3)との接点(C)から凹湾曲状
に延び、該凹湾曲状の曲がりが該チゼル刃(3)との接点
(C)に近付くほど大きく曲がるように、上記副溝(4)を形
成したことを特徴とするドリル。1. A chip discharging groove is composed of a main groove (5) and a sub groove (4), and a tip cutting edge has a line of intersection between a tip conical surface and an inner peripheral surface of the main groove (5). The main cutting edge (1a) formed by, and the main cutting edge (1a) formed by the line of intersection of the tip conical surface and the inner peripheral surface of the sub groove (4).
a) a secondary cutting edge (1b) continuous with a and a chisel blade (3) continuous with the secondary cutting edge (1b), wherein the secondary cutting is performed in a drill (10) having a diameter D. When the blade (1b) is farthest from the straight line connecting the sub-groove side end of the main cutting edge (1a) and the sub-groove side end of the chisel blade (3), substantially 0.03D is drilled (10). ) Land part (6)
Located on the side of the chisel blade (3) and extends in a concave curve from the contact point (C) with the chisel blade (3), and the concave curve has a contact point with the chisel blade (3).
A drill characterized in that the sub-groove (4) is formed so as to bend more as it gets closer to (C).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15311987A JPH0620655B2 (en) | 1987-06-17 | 1987-06-17 | Drill |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15311987A JPH0620655B2 (en) | 1987-06-17 | 1987-06-17 | Drill |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63318207A JPS63318207A (en) | 1988-12-27 |
| JPH0620655B2 true JPH0620655B2 (en) | 1994-03-23 |
Family
ID=15555389
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15311987A Expired - Fee Related JPH0620655B2 (en) | 1987-06-17 | 1987-06-17 | Drill |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0620655B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7740426B2 (en) | 2002-10-02 | 2010-06-22 | Osg Corporation | Deep-hole drill having back-tapered web |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02298407A (en) * | 1989-05-09 | 1990-12-10 | Toshiaki Hosoi | Drill |
| SE507842C2 (en) * | 1992-09-24 | 1998-07-20 | Sandvik Ab | Drill |
| JP6342662B2 (en) * | 2014-01-29 | 2018-06-13 | 京セラ株式会社 | Drill and method of manufacturing cut product using the same |
-
1987
- 1987-06-17 JP JP15311987A patent/JPH0620655B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7740426B2 (en) | 2002-10-02 | 2010-06-22 | Osg Corporation | Deep-hole drill having back-tapered web |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63318207A (en) | 1988-12-27 |
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