JP6359419B2

JP6359419B2 - drill

Info

Publication number: JP6359419B2
Application number: JP2014215045A
Authority: JP
Inventors: 喜彦平角
Original assignee: Sodick Co Ltd
Current assignee: Sodick Co Ltd
Priority date: 2014-10-22
Filing date: 2014-10-22
Publication date: 2018-07-18
Anticipated expiration: 2034-10-22
Also published as: JP2016078209A

Description

本発明は、被加工物に対して回転する工具の回転軸方向に穴あけを行なうための工具であるドリルに関する。 The present invention relates to a drill that is a tool for making a hole in the direction of the rotation axis of a tool that rotates relative to a workpiece.

一般的にドリルは、棒状のドリル本体の先端に形成される円錐状の先端部と、ドリル本体の基部に回転駆動装置に保持される柄部となるシャンクと、ドリル本体の先端部に形成される切れ刃と、そして、ドリル本体のボデー（以下、胴部と称する）の外周面に形成されて切れ刃で切削された切り屑を外部に排出するための溝（以下、切屑排出溝と称する）と、を有して、ドリル本体の軸周りに回転させながらドリル本体の先端を被加工物に押し当てるようにして、被加工物に対してドリルの回転軸方向の穴をあけるための工具である。ここで、ドリルで加工される穴には、貫通孔や底付き穴などが含まれる。 In general, a drill is formed at a conical tip formed at the tip of a rod-shaped drill body, a shank serving as a handle held by a rotary drive device at the base of the drill body, and a tip of the drill body. And a groove (hereinafter referred to as a chip discharge groove) for discharging the chips formed on the outer peripheral surface of the body (hereinafter referred to as the body portion) of the drill body and cut by the cutting edge to the outside. And a tool for making a hole in the direction of the rotation axis of the drill against the workpiece by rotating the drill body around the axis of the drill body and pressing the tip of the drill body against the workpiece. It is. Here, the hole processed by the drill includes a through hole, a hole with a bottom, and the like.

ドリルの切れ刃は、ドリルの先端部の端面に形成される逃げ面と切屑排出溝に続くすくい面の間の交線から成る。そして、その交線は、例えば、先端部の回転中心の部分に形成されるチゼルエッジのコーナからドリルの外周と切れ刃とが交わる点から成る外周コーナまでの間であって、単純な一直線の場合が多い。また、切れ刃から続くすくい面は、例えば、ドリルの胴部の外周面にドリルの先端側から基部側にわたって螺旋状に形成される切屑排出溝に続くように形成されているので、ドリルの回転中心側から外周コーナ側に向って、すくい角が徐々に大きくなるように形成されて、ねじれ面のように形成されている。そうした切れ刃で切削される切り屑は、切れ刃の回転中央側と外周コーナ側で切削速度差やすくい角が異なることで横向きにカールする。また、切り屑は、切り屑速度よりも切削速度の方が速いことから、上向きにカールするように切削した穴の内面に巻き込まれやすい。また、切り屑は、例えば、すくい面がねじれ面であれば円錐螺旋形の切り屑になる。 The cutting edge of a drill consists of the intersection line between the flank formed in the end surface of the front-end | tip part of a drill, and the rake face which follows a chip discharge groove. The intersection line is, for example, between the corner of the chisel edge formed at the center of rotation of the tip part and the outer periphery corner formed by the point where the outer periphery of the drill intersects with the cutting edge, and is a simple straight line. There are many. In addition, the rake face that continues from the cutting edge is formed so as to follow a chip discharge groove formed in a spiral shape from the distal end side to the base side of the drill on the outer peripheral surface of the drill body, for example. The rake angle is formed so as to gradually increase from the center side toward the outer peripheral corner side, and is formed like a twisted surface. Chips cut by such a cutting edge curl sideways because the cutting speed is easily different between the rotation center side and the peripheral corner side of the cutting edge. In addition, since the cutting speed is faster than the cutting speed, the chips are easily caught in the inner surface of the hole that is cut so as to curl upward. Further, for example, if the rake face is a twisted face, the chips become conical spiral chips.

そうしたドリルでは、例えば、被加工物の材料などに起因して、厚い切り屑が連続して生成されてしまうと、その切り屑がドリルに巻き付いてドリルを折損することがある。そのため、特許文献１の穴あけ工具では、先端部を逃げ面側から観たときに、逃げ面とすくい面の交線からなる切れ刃の形状がドリル本体の回転中心から外周側に向って順次それぞれ２個以上形成された滑らかな凸曲線部と滑らかな凹曲線部とから構成されて、凹曲線部に対して凸曲線部を切削回転方向に先行して突出させることを開示している。 In such a drill, for example, if thick chips are continuously generated due to the material of the workpiece, the chips may wrap around the drill and break the drill. Therefore, in the drilling tool of Patent Document 1, when the tip portion is viewed from the flank side, the shape of the cutting edge formed by the line of intersection of the flank and the rake face is sequentially increased from the rotation center of the drill body toward the outer peripheral side. It is disclosed that two or more smooth convex curve portions and smooth concave curve portions are formed, and the convex curve portions are protruded ahead of the concave curve portion in the cutting rotation direction.

特許文献１の穴あけ工具では、切り屑が切れ刃の凸曲線部および凹曲線部に対応して生じて、凸曲線部から生じる切り屑が、すくい面の凸曲面部で押し広げられて細かく分断されて、凹曲線部から生じる切屑が、凹曲線部に対応して断面円弧状となつて延び、この凹曲線部に隣接しかつ凹曲線部より回転中心側に位置する凸曲面部に押し当たつて急激にカールさせられて扇状に細かく分断される。そのうえ、切り屑は、隣接する凸曲線部の凹曲線部側の部分から生じる切り屑に干渉して、凹曲線部から生じる切り屑がより一層確実に分断される。しかも、凸曲線部と凹曲線部とを順次それぞれ２個以上設けているから、切刃から生じる切り屑はより一層細かく分断される。この結果、切り屑がドリルに巻きついてドリルが折損したり、あるいは切り屑が穴の壁面を擦って穴の面粗度が悪化したりすることを防止するようにしている。 In the drilling tool disclosed in Patent Document 1, chips are generated corresponding to the convex curve portion and the concave curve portion of the cutting edge, and the chips generated from the convex curve portion are pushed apart by the convex curved surface portion of the rake face and finely divided. The chip generated from the concave curve portion extends in a circular arc shape corresponding to the concave curve portion, and is pressed against the convex curved surface portion adjacent to the concave curve portion and positioned closer to the center of rotation than the concave curve portion. It is curled suddenly and cut into fan-shaped pieces. In addition, the chips interfere with the chips generated from the portion of the adjacent convex curve portion on the concave curve portion side, and the chips generated from the concave curve portion are more reliably divided. In addition, since two or more convex curve portions and concave curve portions are sequentially provided, chips generated from the cutting blade are further finely divided. As a result, it is possible to prevent the chips from being wound around the drill and breaking the drill, or the chips from rubbing against the wall surface of the hole to deteriorate the surface roughness of the hole.

実公昭６２−００８９７３号公報Japanese Utility Model Publication No. 62-008973

しかしながら、特許文献１の穴あけ工具に限らずドリルは、更なる切削速度の高速化が望まれる。また、例えば、直径１．０ｍｍ以下のような微細な穴あけを行なうような直径の小さなドリルでは、特に切削加工中の穴に切り屑を詰まらせることなく、切削加工中の穴の外に適当な大きさに分断された切り屑を排出させて、切り屑がドリルに巻き付いてドリルを折損させることなく、加工後の穴の面粗度も悪化させないようにすることが望まれる。また、そうした微細な穴あけを行なう直径の小さなドリルでは、小さな切れ刃に対する微細な加工にも限界がある。 However, the drill is not limited to the drilling tool disclosed in Patent Document 1, and further increase in the cutting speed is desired. In addition, for example, in a drill having a small diameter such as making a fine hole having a diameter of 1.0 mm or less, it is suitable for the outside of the hole being cut without clogging chips in the hole being cut. It is desirable to discharge the chips that have been divided into sizes so that the chips do not wrap around the drill and break the drill, and the surface roughness of the hole after processing is not deteriorated. In addition, with a small-diameter drill for performing such fine drilling, there is a limit to fine processing for a small cutting edge.

そこで、本発明のドリルでは、直径の大きなドリルから直径の小さなドリルまで容易に加工できる切れ刃の形状でありながら、切削抵抗を小さくして更なる切削速度の高速化を可能にすること、切り屑を適当な大きさに分断しながら確実に排出するとともに切り屑が巻きついてドリルを折損させることを防止すること、また、切れ刃の剛性を高めることを目的とする。 Therefore, the drill of the present invention has a cutting edge shape that can be easily machined from a drill with a large diameter to a drill with a small diameter, while reducing the cutting resistance and further increasing the cutting speed. An object of the present invention is to reliably discharge the waste while dividing it into an appropriate size, prevent the chips from being wound and break the drill, and increase the rigidity of the cutting edge.

本発明のドリルでは、軸周りに回転してかつ当該軸方向に前進することで、先端部に有する切れ刃で被加工物を切削しかつ切り屑を胴部に有する切屑排出溝から排出するようにして、前記被加工物に前記軸方向に穴あけを行なうためのドリルであって、前記切れ刃が前記先端部の端面から成る逃げ面と前記切屑排出溝に続くすくい面との間の交線から成り、前記逃げ面上の前記交線が前記回転の方向に凹と成る凹曲線部を連続して２つ以上並べてある形状であるとともに前記回転の方向に凸と成る隣り合う前記凹曲線部の端同士を直結して成る凸部を１つ以上有する形状と成るように、前記交線から続く前記すくい面に当該交線の各前記凹曲線部から続けて断面が凹曲線でかつ同一直線方向の各凹曲線断面溝を並べて形成して、前記各凹曲線断面溝のすくい角よりも前記各凹曲線断面溝同士の間の稜線のすくい角の方が大きく前記切屑排出溝が前記胴部の外周面に先端側から基部側に向かって螺旋状に形成されて、前記すくい面が回転中心側から外周コーナ側に向かって前記すくい角が徐々に大きくなるねじれ面に形成されて、前記各凹曲線断面溝同士の間の前記稜線および一番外周側の前記凹曲線断面溝とリーディングエッジの間の稜線のそれぞれのすくい角が前記回転中心側の前記稜線のすくい角よりも前記外周コーナ側の前記稜線のすくい角の方が大きく形成されて、回転軸の軸方向に平行な方向の前記各凹曲線断面溝を並べて形成して、前記各凹曲線断面溝のすくい角がすべてゼロであることを特徴とする。
In the drill according to the present invention, the workpiece is cut with the cutting edge at the tip and discharged from the chip discharge groove at the body by rotating around the axis and moving forward in the axial direction. A drill for making a hole in the workpiece in the axial direction, wherein the cutting edge is a line of intersection between a flank formed by an end face of the tip and a rake face following the chip discharge groove The adjacent concave curve portions that have a shape in which two or more concave curve portions in which the intersecting line on the flank face is concave in the direction of rotation and are convex in the direction of rotation are formed. The cross-section is a concave curve and the same straight line from each concave curve portion of the intersection line to the rake face continuing from the intersection line so as to have a shape having one or more convex portions formed by directly connecting the ends of the intersection line to form side by side each concave curve section groove direction, each concave curve The rake angle of the ridgeline between the concave curved cross-section grooves is larger than the rake angle of the surface groove, and the chip discharge groove is formed in a spiral shape on the outer peripheral surface of the body portion from the front end side to the base side. The rake face is formed on a torsion surface in which the rake angle gradually increases from the rotation center side toward the outer peripheral corner side, and the ridge line between the concave curved cross-section grooves and the outermost peripheral side The rake angle of each ridge line between the concave curved cross-sectional groove and the leading edge is formed such that the rake angle of the ridge line on the outer peripheral corner side is larger than the rake angle of the ridge line on the rotation center side. The concave curved cross-sectional grooves in a direction parallel to the axial direction are formed side by side, and the rake angles of the concave curved cross-sectional grooves are all zero .

また、本発明のドリルでは、前記先端部の直径が０．５ｍｍ以下で、前記先端部に有する前記切れ刃の耐磨耗性が、多結晶焼結ダイヤモンド（ＰＣＤ）よりも低いと良い。
In the drill of the present invention, it is preferable that the tip portion has a diameter of 0.5 mm or less and the wear resistance of the cutting edge included in the tip portion is lower than that of polycrystalline sintered diamond (PCD).

本発明のドリルは、切れ刃が逃げ面とすくい面との間の交線から成り、逃げ面上の交線が回転の方向に凹と成る凹曲線部を連続して２つ以上並べてある形状であるとともに回転の方向に凸と成る隣り合う凹曲線の端同士を直結して成る凸部を１つ以上有する形状と成るように、切れ刃を成す交線から続くすくい面に当該交線の各凹曲線部から続けて断面が凹曲線でかつ同一直線方向の各凹曲線断面溝を並べて形成して成ることで、容易に加工できる切れ刃の形状でありながら、すくい面上に並ぶ同一直線方向、好ましくは、回転軸の軸方向に平行した直線方向の各凹曲線断面溝によって、すくい角がドリルの回転中心側から外周コーナ側までほぼ同じになってすくい面のねじれがなくなり、加えて切れ刃の凹曲線部によって切れ刃上の各位置における切れ刃の垂直な方向が当該位置に応じて異なることで流出角もなくなるので、そうしたすくい面に押し出されるようにして排出される切り屑は、横向きや上向きにカールすることを抑制されて、切り屑が連続する円錐螺旋形の切り屑にならずに、被加工物の材料の種類に応じて、ストレート形状または切り屑の連なる方向の断面が折り畳まれたようなジグザグ形状に形成されて、さらに切り屑の連なる方向に対して垂直の断面が切れ刃と同じ凹曲線部が複数並んだ形状に形成されて、切り屑が排出される中で外力を受けると適当な箇所で折れやすい形状となって、切屑排出溝の中の切り屑が詰まることなく適度な隙間を確保できて、また切屑排出溝の外部に排出されやすい大きさに切り屑を分断して排出させることができる。また、本発明のドリルでは、切り屑が折れやすく、分断されて確実に排出させることができるので、ドリルに切り屑が巻きついてドリルが折れるようなことも防止されることから、切屑排出溝の溝の深さを大きく形成して、すなわち、ドリルの回転軸に垂直な切屑排出溝の断面を大きく形成して、切り屑を排出しやすくすることも可能になり、切削速度の高速化も可能にする。また、本発明のドリルでは、ドリルの回転の方向に凸と成る隣り合う凹曲線の端同士を直結して成る凸部が切れ刃に形成されることで、切削抵抗が低減されることから、切削速度を高速にして、切削加工時間を短縮させることが可能になり、さらには、切れ刃の磨耗も抑制することができる。また、本発明のドリルでは、好ましくは回転軸の軸方向に平行した直線方向の各凹曲線断面溝をすくい面上に並べて形成して成ることで、切れ刃の剛性を高めることも可能になる。また、本発明のドリルでは、切れ刃と逃げ面とすくい面から成るドリル先端部の一部であるウェッジに断面が凹曲線でかつ直線方向の凹曲線断面溝を平行に連続して並べて加工すれば良いので、加工が容易なことで、特に、切削加工時に切り屑が巻きつくと折れやすい直径の小さなドリルであっても本発明を適用することができる。 The drill of the present invention has a shape in which the cutting edge is formed by an intersection line between the flank face and the rake face, and two or more concave curve portions in which the intersection line on the flank face is concave in the direction of rotation are arranged side by side. And the rake face that follows the cutting line forming the cutting line so as to have a shape having one or more convex parts formed by directly connecting the ends of adjacent concave curves that are convex in the direction of rotation. Continuing from each concave curve section, the cross section is a concave curve and each concave curve cross-sectional groove in the same linear direction is formed side by side, so that it is the shape of a cutting edge that can be easily processed, but the same straight line aligned on the rake face Direction, preferably each concave curved cross-section groove in a linear direction parallel to the axial direction of the rotation axis, the rake angle is almost the same from the rotation center side of the drill to the outer corner side, and the rake face is not twisted, Each position on the cutting edge by the concave curve of the cutting edge Since the vertical direction of the cutting edge in the direction differs depending on the position, the outflow angle also disappears, so that the chips discharged as pushed out to such a rake face are curled sideways and upward, Depending on the type of material of the workpiece, it is formed in a straight shape or a zigzag shape in which the cross section in the continuous direction of chips is folded, Furthermore, the cross-section perpendicular to the direction in which the chips are continuous is formed in a shape in which a plurality of concave curve portions that are the same as the cutting edge are arranged, and when it receives external force while the chips are discharged, Thus, an appropriate gap can be secured without clogging the chips in the chip discharge groove, and the chips can be divided and discharged to a size that is easily discharged to the outside of the chip discharge groove. Further, in the drill of the present invention, the chips are easily broken and can be divided and reliably discharged. Therefore, it is possible to prevent the chips from being wrapped around the drill and being broken. It is possible to increase the cutting speed by increasing the depth of the groove, that is, by forming a larger cross section of the chip discharge groove perpendicular to the rotation axis of the drill to facilitate chip discharge. To. Further, in the drill of the present invention, the cutting force is reduced by forming the convex portion formed by directly connecting the ends of adjacent concave curves that are convex in the direction of rotation of the drill, It is possible to shorten the cutting time by increasing the cutting speed, and it is possible to suppress wear of the cutting edge. Further, in the drill of the present invention, it is possible to increase the rigidity of the cutting edge by preferably forming the concave curved cross-section grooves in a linear direction parallel to the axial direction of the rotation axis on the rake face. . Further, in the drill of the present invention, a wedge having a cutting edge, a flank, and a rake face, which is a part of the tip of the drill, has a concave cross-section and a straight concave curved cross-section groove continuously arranged in parallel. Therefore, the present invention can be applied even to a drill having a small diameter that is easy to break, especially when chips are wound during cutting.

本発明のドリルを先端部から当該ドリルの回転軸の軸方向に向かって観た後述される図２のＥ−Ｅ矢視の概略図を示す。The schematic of the EE arrow of FIG. 2 mentioned later which looked at the drill of this invention toward the axial direction of the rotating shaft of the said drill from the front-end | tip part is shown. 本発明のドリルの先端部を側方から観た図１のＤ−Ｄ矢視の概略図を示す。The schematic of the DD arrow of FIG. 1 which looked at the front-end | tip part of the drill of this invention from the side is shown. 本発明のドリルの切れ刃の凹部曲線部の断面図を示し、図（ａ）が図２のＡ１−Ａ１矢視断面図、図（ｂ）が図２のＢ１−Ｂ１矢視断面図、そして、図（ｃ）が図２のＣ１−Ｃ１矢視断面図を示す。Sectional drawing of the recessed part curve part of the cutting edge of the drill of this invention is shown, FIG. (A) is A1-A1 arrow sectional drawing of FIG. 2, FIG. (B) is B1-B1 arrow sectional drawing of FIG. (C) shows the C1-C1 arrow sectional view of FIG. 本発明のドリルの切れ刃の凸部の断面図を示し、図（ａ）が図２のＡ２−Ａ２矢視断面図、図（ｂ）が図２のＢ２−Ｂ２矢視断面図、そして、図（ｃ）が図２のＣ２−Ｃ２矢視断面図を示す。Sectional drawing of the convex part of the cutting edge of the drill of this invention is shown, FIG. (A) is A2-A2 arrow sectional drawing of FIG. 2, FIG. (B) is B2-B2 arrow sectional drawing of FIG. FIG. 2C shows a cross-sectional view taken along the line C2-C2 in FIG. 本発明のドリルで被加工物に穴あけを行なった際に排出される切り屑の一部分の概略図を示し、図（ａ）が折り畳まれてジグザグ形状の切り屑の一部分の概略図を示し、図（ｂ）がストレート形状の切り屑の一部分の概略図を示す。FIG. 1 shows a schematic diagram of a part of chips discharged when a work piece is drilled with a drill of the present invention, FIG. 1 (a) shows a schematic diagram of a part of a zigzag-shaped chip folded, FIG. (B) shows the schematic of a part of straight-shaped chip. 従来のドリルを先端部から当該ドリルの回転軸の軸方向に向かって観た後述される図７のＥ−Ｅ矢視の概略図を示す。The schematic of the EE arrow of FIG. 7 mentioned later which looked at the conventional drill toward the axial direction of the rotating shaft of the said drill from the front-end | tip part is shown. 従来のドリルの先端部を側方から観た図６のＤ−Ｄ矢視の概略図を示す。The schematic of DD arrow of FIG. 6 which looked at the front-end | tip part of the conventional drill from the side is shown. 従来のドリルの切れ刃の凹部曲線部の断面図を示し、図（ａ）が図７のＡ−Ａ矢視断面図、図（ｂ）が図７のＢ−Ｂ矢視断面図、そして、図（ｃ）が図７のＣ−Ｃ矢視断面図を示す。Sectional drawing of the concave curve part of the cutting edge of the conventional drill is shown, FIG. (A) is AA arrow sectional drawing of FIG. 7, FIG. (B) is BB arrow sectional drawing of FIG. The figure (c) shows CC sectional view taken on the line of FIG.

本発明のドリルを図１ないし図４に示すツイストドリルに適用された実施の態様を一例に挙げて説明する。図５に示す切り屑の一部を示す概略図は、本発明のドリルで被加工物に穴あけを行なった際に排出される切り屑の一例を示している。なお、図６ないし図８に示すツイストドリルの実施の態様は、従来のドリルの実施の態様を示しており、同じ構成が同じ符号で示されている。 An embodiment in which the drill of the present invention is applied to the twist drill shown in FIGS. 1 to 4 will be described as an example. The schematic diagram showing a part of the chips shown in FIG. 5 shows an example of the chips discharged when the workpiece is drilled with the drill of the present invention. In addition, the embodiment of the twist drill shown in FIGS. 6 to 8 shows an embodiment of a conventional drill, and the same components are denoted by the same reference numerals.

図１ないし図４に示すドリル１は、円柱形状のような棒形状であって、先端に円錐状の先端部２を有して、基部に図示省略されるシャンクを有している。ドリル１は、図示省略される被加工物を切削加工するための切れ刃４を有して、実施の態様のツイストドリル１であれば一対の切れ刃４をドリル１の先端部２に形成してあり、切れ刃４で切削したあとの切り屑２０を外部に排出するための一対の切屑排出溝５をドリル１の胴部３の外周面３ａにドリル１の先端側から基部側に向って螺旋状に形成してある。それで、ドリル１は、例えば、ドリル１を回転させかつ進退させるためのドリル駆動装置等（図示省略）にシャンクが保持されて、ドリル１の軸心を回転軸Ｑｒにして回転しながら回転軸Ｑｒの軸方向に被加工物に対して前進することで、被加工物に回転軸Ｑｒの軸方向の穴（図示省略）をあけるためのものである。 The drill 1 shown in FIGS. 1 to 4 has a rod shape such as a columnar shape, and has a conical tip 2 at the tip and a shank not shown in the base. The drill 1 has a cutting edge 4 for cutting a workpiece (not shown). If the drill 1 is a twist drill 1 according to the embodiment, a pair of cutting edges 4 are formed at the tip 2 of the drill 1. A pair of chip discharge grooves 5 for discharging the chips 20 after cutting with the cutting edge 4 to the outside are formed on the outer peripheral surface 3a of the body 3 of the drill 1 from the tip side to the base side. It is formed in a spiral shape. Therefore, the drill 1 has a shank held by, for example, a drill driving device (not shown) for rotating and advancing and retracting the drill 1, and the rotation axis Qr while rotating with the axis of the drill 1 as the rotation axis Qr. By moving forward with respect to the workpiece in the axial direction, a hole (not shown) in the axial direction of the rotation axis Qr is formed in the workpiece.

円錐状の先端部２には、先端側の端面２ａに形成される一対の逃げ面６と、各切屑排出溝５にそれぞれ続く一対のすくい面７とを有して、逃げ面６とそれら逃げ面６に対応するすくい面７の間の各交線４から成る一対の切れ刃４と、そして、隣り合う一対の逃げ面６の間の交線から成るチゼルエッジ８とを有しいる。逃げ面６は、切れ刃４が被加工物に切り込んでいく際に、必要以上に被加工物の加工面とドリル１の先端部２の端面２ａの間に摩擦が生じることを避けるために逃がした面である。すくい面７は、切れ刃４から続く面であり、切屑排出溝５に続く面である。切れ刃４は、チゼルエッジ８の両端の各チゼルエッジコーナ８ａから円錐状の先端部２の円錐底面の円周に相当する円周上の各外周コーナ９の間に形成されている。切れ刃４からドリル１の回転方向（図１では、反時計周りに回転）に対して前方の部分は、切屑排出溝５の先端部側の開口と成る空間５ａが形成されている。各外周コーナ９からドリル１の回転方向に対して後方の部分には、それぞれマージン１０が形成されて、ドリル１の胴部３の外周面３ａにドリル１の基部まで螺旋状に形成されている。また、各マージン１０からドリル１の回転方向に対して後方の部分には、マージン１０の部分よりもニ番取り深さの寸法だけ先端部２の外径の小さい一対のニ番取り面１３が形成されて、ドリル１の胴部３の外周面３ａにドリル１の基部まで螺旋状に形成されている。その他、各二番取り面１３とドリル１の回転方向に対して後方にある各切屑排出溝５の間の交線は、ヒール１２と称される。また、マージン１０と切屑排出溝５の間の交線は、リーディングエッジ１１と称される。また、リーディングエッジ１１からヒール１２までは、ランドと称される。各構成は、例えば、図１に示されるツイストドリル１の実施の態様であれば、ツイストドリル１を先端部２側から回転軸Ｑｒの軸方向に向かって観て、ドリル１の回転軸Ｑｒを回転中心に１８０度の回転対称の位置にそれぞれ形成されている。 The conical tip portion 2 has a pair of flank surfaces 6 formed on the end surface 2a on the tip side and a pair of rake surfaces 7 respectively connected to the chip discharge grooves 5, and the flank surfaces 6 and the flank surfaces thereof. It has a pair of cutting edges 4 consisting of each line of intersection 4 between the rake faces 7 corresponding to the face 6 and a chisel edge 8 consisting of a line of intersection between a pair of adjacent flank faces 6. The flank 6 is provided to avoid friction between the work surface of the workpiece and the end surface 2a of the tip 2 of the drill 1 when the cutting edge 4 cuts into the work. It is the surface. The rake face 7 is a face that continues from the cutting edge 4 and is a face that continues to the chip discharge groove 5. The cutting edge 4 is formed between each chisel edge corner 8 a at both ends of the chisel edge 8 and each outer peripheral corner 9 on the circumference corresponding to the circumference of the conical bottom surface of the conical tip 2. A space 5a serving as an opening on the tip end side of the chip discharge groove 5 is formed at a front portion of the cutting blade 4 with respect to the rotation direction of the drill 1 (rotation counterclockwise in FIG. 1). Margins 10 are formed in the rear portions of each outer peripheral corner 9 with respect to the rotation direction of the drill 1, and are formed in a spiral shape on the outer peripheral surface 3 a of the body 3 of the drill 1 up to the base of the drill 1. . In addition, a pair of second numbering surfaces 13 having a smaller outer diameter of the tip end portion 2 by the dimension of the second numbering depth than that of the margin 10 part are provided in the rear part from each margin 10 with respect to the rotation direction of the drill 1. Thus formed, the outer peripheral surface 3 a of the body portion 3 of the drill 1 is spirally formed to the base portion of the drill 1. In addition, the line of intersection between each second picking surface 13 and each chip discharge groove 5 located rearward with respect to the rotation direction of the drill 1 is referred to as a heel 12. An intersection line between the margin 10 and the chip discharge groove 5 is referred to as a leading edge 11. Further, the leading edge 11 to the heel 12 are referred to as a land. For example, if each configuration is an embodiment of the twist drill 1 shown in FIG. 1, the twist drill 1 is viewed from the distal end portion 2 side in the axial direction of the rotation axis Qr, and the rotation axis Qr of the drill 1 is set. Each is formed at a rotationally symmetric position of 180 degrees around the center of rotation.

ここからは本発明の特有のドリル１の構成が説明される。本発明のドリル１は、逃げ面６の面上に形成される切れ刃４を成す交線４が、ドリル１の回転方向に凹と成る凹曲線部１５を連続して２つ以上並べてある形状であるとともにドリル１の回転方向に凸と成るように隣り合う凹曲線部１５の端同士を直結して成る凸部１６を１つ以上有する形状であって、切れ刃４から続くすくい面７に切れ刃４を成す交線４の各凹曲線部１５から続けて断面が凹曲線でかつ同一直線方向、好ましくは、回転軸Ｑｒの軸方向に平行する方向の各凹曲線断面溝１７を並べて形成して成る。 From here, the structure of the drill 1 peculiar to this invention is demonstrated. In the drill 1 of the present invention, the intersecting line 4 forming the cutting edge 4 formed on the surface of the flank 6 has a shape in which two or more concave curve portions 15 that are concave in the rotation direction of the drill 1 are continuously arranged. And having one or more convex portions 16 formed by directly connecting the ends of the concave curve portions 15 adjacent to each other so as to be convex in the rotation direction of the drill 1, on the rake face 7 continuing from the cutting edge 4 Continuing from the concave curve portions 15 of the intersecting line 4 forming the cutting edge 4, the concave curved cross-section grooves 17 having a concave cross section and the same linear direction, preferably parallel to the axial direction of the rotation axis Qr, are formed side by side. It consists of

例えば、図１ないし図４に示すツイストドリル１の実施の態様では、チゼルエッジコーナ８ａから外周コーナ９までの間に形成されている各切れ刃４に、逃げ面６の面上に形成される切れ刃４を成す交線４が、ドリル１の回転方向にへこんでいる３つの同じ凹曲線部１５（１５ａ、１５ｂ、１５ｃ）を連続して並べてある形状であり、隣り合う凹曲線部１５ａと１５ｂの端同士を直結して成る部分、隣り合う凹曲線部１５ｂと１５ｃの端同士を直結して成る部分にドリルの回転方向に突き出る同じ２つの凸部１６（１６ａ、１６ｂ）および最もドリル１の外周に形成される凹曲線部１５ｃの端とドリル１の外周コーナ９を直結して成る部分にドリル１の回転方向に突き出る１つの凸部１６（１６ｃ）を有する形状に形成されている。切れ刃４の凸部１６は、被加工物を切削する際の切削抵抗を低減して、切削速度を高速にして、切削加工の時間を短縮することを可能にして、さらには、切れ刃４の磨耗も抑制することができる。 For example, in the embodiment of the twist drill 1 shown in FIG. 1 to FIG. 4, each cutting edge 4 formed between the chisel edge corner 8 a and the outer periphery corner 9 is formed on the surface of the flank 6. The intersecting line 4 forming the cutting edge 4 has a shape in which three identical concave curve portions 15 (15a, 15b, 15c) that are recessed in the rotation direction of the drill 1 are continuously arranged, and adjacent concave curve portions 15a The same two convex portions 16 (16a, 16b) projecting in the direction of rotation of the drill into the portion formed by directly connecting the ends of 15b, the portion formed by directly connecting the ends of the adjacent concave curve portions 15b and 15c, and the most drill 1 Is formed in a shape having one convex portion 16 (16c) protruding in the rotation direction of the drill 1 at a portion formed by directly connecting the end of the concave curve portion 15c formed on the outer periphery of the drill 1 and the outer peripheral corner 9 of the drill 1. The convex portion 16 of the cutting edge 4 can reduce cutting resistance when cutting the workpiece, increase the cutting speed, shorten the cutting time, and further, the cutting edge 4. Can also be suppressed.

各切れ刃４に形成される３つの凹曲線部１５ａ、１５ｂ、１５ｃと３つの凸部１６ａ、１６ｂ、１６ｃは、切れ刃４から続くすくい面７の少なくとも一部に切れ刃４に形成される３つの同じ凹曲線部１５ａ、１５ｂ、１５ｃから続けて、断面が同じ凹曲線でかつ回転軸Ｑｒの軸方向に平行する方向に３つの凹曲線断面溝１７（１７ａ、１７ｂ、１７ｃ）を加工することで形成されている。これら凹曲線断面溝１７ａ、１７ｂ、１７ｃは、例えば、断面の凹曲線を成す両端部の間の直線距離よりも大きい直径のエンドミルをドリル１の回転軸Ｑｒと平行する軸周りに回転させて、切れ刃４、すくい面７および逃げ面６から成るウェッジ１４に断面が円弧の溝を切削加工するだけでも形成できることから加工が非常に容易である。したがって、本発明のドリル１は、例えば、直径が０．５ｍｍ以下のような極小さな直径のドリル１であっても適用が可能である。なお、ドリル１の切れ刃４を切削加工するエンドミル等の切削工具の切れ刃の材料は、ドリル１の切れ刃４の材料に対応して、高速度工具鋼、超硬合金、多結晶立方晶窒化珪素（ＰｃＢＮ）、多結晶焼結ダイヤモンド（ＰＣＤ）のように、ドリル１の切れ刃４より高い耐磨耗性を有する高硬度材から選ばれると良い。 Three concave curve portions 15 a, 15 b, 15 c and three convex portions 16 a, 16 b, 16 c formed on each cutting edge 4 are formed on the cutting edge 4 on at least a part of the rake face 7 that continues from the cutting edge 4. Three concave curve cross-section grooves 17 (17a, 17b, 17c) are machined in a direction parallel to the axial direction of the rotation axis Qr, with the same concave curve in cross section, starting from three identical concave curve portions 15a, 15b, 15c. It is formed by that. These concave curved cross-section grooves 17a, 17b, and 17c are formed by, for example, rotating an end mill having a diameter larger than a linear distance between both ends forming a concave curved section in a circle around an axis parallel to the rotation axis Qr of the drill 1. Since the wedge 14 comprising the cutting edge 4, the rake face 7 and the flank face 6 can be formed simply by cutting a groove having a circular cross section, the machining is very easy. Therefore, the drill 1 of the present invention can be applied even to a drill 1 having a very small diameter such as 0.5 mm or less. Note that the material of the cutting edge of the cutting tool such as an end mill for cutting the cutting edge 4 of the drill 1 corresponds to the material of the cutting edge 4 of the drill 1, high-speed tool steel, cemented carbide, polycrystalline cubic crystal. It is preferable to select a high hardness material having higher wear resistance than the cutting edge 4 of the drill 1 such as silicon nitride (PcBN) and polycrystalline sintered diamond (PCD).

それで、本発明のドリル１は、図３に示すように、すくい面７のうちの同じ直線方向に向って形成されている複数の凹曲線断面溝１７ａ、１７ｂ、１７ｃの内周面１７０ａ、１７０ｂ、１７０ｃが、チゼルエッジコーナ８ａから外周コーナ９に向って、すくい角θａ１、θｂ１、θｃ１が同じになるように形成されて（θａ１＝θｂ１＝θｃ１）、好ましくは、複数の凹曲線断面溝１７ａ、１７ｂ、１７ｃの内周面１７０ａ、１７０ｂ、１７０ｃがドリル１の回転軸Ｑｒに平行する方向に向って形成されて、チゼルエッジコーナ８ａから外周コーナ９に向って、すくい角θａ１、θｂ１、θｃ１がゼロになるように形成される（θａ１＝θｂ１＝θｃ１＝ゼロ）。また、本発明のドリル１は、図４に示すように、すくい面７のうちの隣り合う凹曲線断面溝１７同士の間（１７ａと１７ｂの間および１７ｂと１７ｃの間）の稜線１８（１８ａ、１８ｂ）および一番外周側の凹曲線断面溝１７ｃとリーディングエッジ１１の間の稜線１９が、チゼルエッジコーナ８ａから外周コーナ９に向って、すくい角θａ２、θｂ２、θｃ２が徐々に大きくなるように形成されて（θａ２＜θｂ２＜θｃ２）、また、複数の凹曲線断面溝１７ａ、１７ｂ、１７ｃの内周面１７０ａ、１７０ｂ、１７０ｃがドリル１の回転軸Ｑｒに平行する方向に形成することで、切れ刃４の剛性を高めることもできる。ここで、すくい角θａ１、θｂ１、θｃ１、θａ２、θｂ２、θｃ２の角度は、回転軸Ｑｒと平行する軸の角度をゼロとして、回転軸Ｑｒに平行する軸とすくい面７の所定の位置との間の角度とする。 Therefore, as shown in FIG. 3, the drill 1 of the present invention has inner peripheral surfaces 170a, 170b of a plurality of concave curved cross-section grooves 17a, 17b, 17c formed in the same linear direction of the rake face 7. , 170c are formed so that the rake angles θa1, θb1, and θc1 are the same from the chisel edge corner 8a toward the outer peripheral corner 9 (θa1 = θb1 = θc1), and preferably a plurality of concave curved cross-sectional grooves 17a , 17b, 17c are formed in a direction parallel to the rotation axis Qr of the drill 1, and rake angles θa1, θb1, θc1 from the chisel edge corner 8a to the outer corner 9 are formed. Is formed to be zero (θa1 = θb1 = θc1 = zero). Further, as shown in FIG. 4, the drill 1 of the present invention has a ridge line 18 (18a) between adjacent concave curved cross-sectional grooves 17 (between 17a and 17b and 17b and 17c) of the rake face 7. 18b) and the ridge line 19 between the outermost concave curved cross-section groove 17c and the leading edge 11 so that the rake angles θa2, θb2, and θc2 gradually increase from the chisel edge corner 8a toward the outer peripheral corner 9. (Θa2 <θb2 <θc2), and the inner peripheral surfaces 170a, 170b, 170c of the plurality of concave curved cross-section grooves 17a, 17b, 17c are formed in a direction parallel to the rotation axis Qr of the drill 1. The rigidity of the cutting edge 4 can also be increased. Here, the rake angles θa1, θb1, θc1, θa2, θb2, and θc2 are set such that the angle of the axis parallel to the rotation axis Qr is zero, and the axis parallel to the rotation axis Qr and a predetermined position of the rake face 7 The angle between.

したがって、本発明のドリル１は、チゼルエッジコーナ８ａ側から外周コーナ９側までの切れ刃４の大部分の範囲において、すくい角θａ１、θｂ１、θｃ１が略等しくなって、好ましくは、ドリル１の回転軸Ｑｒの軸方向に平行することによって、すくい面７のねじれがなくなり、さらには、切れ刃４の複数の凹曲線部１５によって切れ刃４上の各位置における切れ刃４に垂直な方向が当該位置に応じて異なることで流出角もなくなり、そのような形状のすくい面７に押し出されるようにして、例えば、被加工物の材料がチタンであれば、図５（ａ）に示す切り屑２０のように、切り屑２０の連なる方向の断面が折り畳まれたようなジグザグ形状の切り屑２０となり、例えば、被加工物の材料がアルミであれば、図５（ｂ）に示す切り屑２０のようなストレート形状の切り屑２０となるといったように、被加工物の材料の種類に応じてジグザグ形状またはストレート形状の切り屑２０に形成されて、さらに切り屑２０の連なる方向に対して垂直の断面が切れ刃４の凹曲線部１５で形成された凹曲線部２１ａ、２１ｂ、２１ｃと切れ刃４の凸部１６で形成された凸部２２ａ、２２ｂ、２２ｃを有する形状の切り屑２０となって、横向きや上向きにカールされることなく排出されることになる。本発明のドリル１によって切削加工中に排出される切り屑２０は、特に、切り屑２０の凹曲線部２１ａ、２１ｂ、２１ｃと凸部２２ａ、２２ｂ、２２ｃの形状によって、切屑排出溝５の中で外力を受けると適当な箇所で切れやすくまたは折れやすい形状であって、例えば、切り屑２０の連なる方向に対して略垂直な方向からの外力を受けると折れやすい形状であるので、切屑排出溝５の中で適度な隙間を確保しながら、確実に切屑排出溝５の外部に切り屑２０を排出させる大きさに短く分断される。また、そうした形状の切り屑２０は、ドリル１に巻きつこうとした場合にも、その前に切り屑が折れて分断されることから、ドリル１に切り屑２０が巻きついてドリル１を折損させることも防止できる。 Therefore, in the drill 1 of the present invention, the rake angles θa1, θb1, and θc1 are substantially equal in the most range of the cutting edge 4 from the chisel edge corner 8a side to the outer peripheral corner 9 side. By being parallel to the axial direction of the rotation axis Qr, the rake face 7 is not twisted, and the direction perpendicular to the cutting edge 4 at each position on the cutting edge 4 by the plurality of concave curved portions 15 of the cutting edge 4 is further improved. If the material of the workpiece is titanium, for example, if the material of the work piece is titanium, the outflow angle is eliminated by being different depending on the position, and the discharge angle is eliminated, so that the chip is shown in FIG. As shown in FIG. 5, the zigzag-shaped chip 20 in which the cross-section in the continuous direction of the chips 20 is folded. For example, if the material of the workpiece is aluminum, the chip 20 shown in FIG. It is formed into a zigzag-shaped or straight-shaped chip 20 according to the type of material of the workpiece so that it becomes such a straight-shaped chip 20, and is perpendicular to the direction in which the chips 20 continue. The cross-section is a chip 20 having a shape having concave curve portions 21a, 21b, 21c formed by the concave curve portion 15 of the cutting edge 4 and convex portions 22a, 22b, 22c formed by the convex portion 16 of the cutting edge 4. Thus, the paper is discharged without being curled sideways or upward. The chips 20 discharged during the cutting process by the drill 1 of the present invention are in particular in the chip discharge grooves 5 depending on the shapes of the concave curved portions 21a, 21b, 21c and the convex portions 22a, 22b, 22c of the chips 20. When the external force is applied, the shape is easily cut or broken at an appropriate location. For example, when the external force is applied from a direction substantially perpendicular to the continuous direction of the chips 20, the chip discharge groove 5, while ensuring an appropriate gap, the chip 20 is cut into pieces that are surely discharged to the outside of the chip discharge groove 5. Further, even when the chip 20 having such a shape is to be wound around the drill 1, the chip 20 is broken and divided before that, so that the chip 20 is wound around the drill 1 to break the drill 1. Can also be prevented.

本発明のドリル１は、切れ刃４に形成される凹曲線部１５の両端部の間の距離、凹曲線部１５の形状、凹曲線断面溝１７の形状を前述の実施の態様に限定されることなく、また、複数有することになる各凹曲線部１５および各凹曲線断面溝１７の形状および寸法がそれぞれ異なっていても良いし、それらの形状や寸法がすべて同じであっても良いし、それらの形状や寸法が同じものと異なるものを適宜合わせてあっても良い。また、本発明のドリル１は、ツイストドリルに限定されずに、少なくとも１つ以上の切れ刃４を有するドリルに適用が可能である。 In the drill 1 of the present invention, the distance between both end portions of the concave curve portion 15 formed on the cutting edge 4, the shape of the concave curve portion 15, and the shape of the concave curve cross-sectional groove 17 are limited to the above-described embodiments. Without limitation, the shape and size of each concave curve portion 15 and each concave curve cross-sectional groove 17 to be provided may be different, or the shape and size may be the same, Those having the same or different shapes and dimensions may be appropriately combined. The drill 1 of the present invention is not limited to a twist drill, but can be applied to a drill having at least one cutting edge 4.

本発明は、被加工物に対して回転する工具の回転軸方向に穴あけを行なうための工具であるドリルに利用できる。 INDUSTRIAL APPLICABILITY The present invention can be used for a drill that is a tool for making a hole in the rotation axis direction of a tool that rotates with respect to a workpiece.

１ドリル
２先端部
２ａ先端部の端面
３胴部
３ａ胴部の外周面
４切れ刃（逃げ面とすくい面の間の交線）
５切屑排出溝
５ａ切屑排出溝の先端部側の開口と成る空間
６逃げ面
７すくい面
８チゼルエッジ
８ａチゼルエッジコーナ
９外周コーナ
１０マージン
１１リーディングエッジ
１２ヒール
１３ニ番取り面
１４ウェッジ
１５切れ刃の凹曲線部
１５ａ、１５ｂ、１５ｃ切れ刃の凹曲線部
１６切れ刃の凸部
１６ａ、１６ｂ、１６ｃ切れ刃の凸部
１７凹曲線断面溝
１７ａ、１７ｂ、１７ｃ凹曲線断面溝
１８凹曲線断面溝同士の間の稜線
１８ａ、１８ｂ凹曲線断面溝同士の間の稜線
１９一番外周側の凹曲線断面溝とリーディングエッジの間の稜線
２０切り屑
２１ａ、２１ｂ、２１ｃ切り屑の凹曲線部
２２ａ、２２ｂ、２２ｃ切り屑の凸部
１７０ａ、１７０ｂ、１７０ｃ凹曲線断面溝の内周面
Ｑｒドリルの回転軸 DESCRIPTION OF SYMBOLS 1 Drill 2 Front-end | tip part 2a End surface 3 of the front-end | tip body 3a 3a Outer peripheral surface of a trunk | drum 4 Cutting edge (intersection line between flank and rake face)
5 Chip Discharge Groove 5a Space for Opening on the Tip Side of Chip Discharge Groove 6 Flank 7 Rake Face 8 Chisel Edge 8a Chisel Edge Corner 9 Peripheral Corner 10 Margin 11 Leading Edge 12 Heel 13 Die Cutting Surface 14 Wedge 15 Cutting Edge Concave curve portion 15a, 15b, 15c Concave curve portion 16 of cutting edge Convex portion 16a, 16b, 16c of cutting edge Convex portion 17 of cutting edge Concave cross section groove 17a, 17b, 17c Concave cross section groove 18 Concave cross section grooves Ridge lines 18a, 18b between the concave curve cross-section grooves 19 Ridge lines 19 between the outermost concave curve cross-section grooves and the leading edge Chips 21a, 21b, 21c Chip concave curve sections 22a, 22b , 22c Chip convex portions 170a, 170b, 170c Inner peripheral surface Qr of concave curved cross-sectional groove Drill rotation axis

Claims

軸周りに回転してかつ当該軸方向に前進することで、先端部に有する切れ刃で被加工物を切削しかつ切り屑を胴部に有する切屑排出溝から排出するようにして、前記被加工物に前記軸方向に穴あけを行なうためのドリルであって、
前記切れ刃が前記先端部の端面から成る逃げ面と前記切屑排出溝に続くすくい面との間の交線から成り、
前記逃げ面上の前記交線が前記回転の方向に凹と成る凹曲線部を連続して２つ以上並べてある形状であるとともに前記回転の方向に凸と成る隣り合う前記凹曲線部の端同士を直結して成る凸部を１つ以上有する形状と成るように、前記交線から続く前記すくい面に当該交線の各前記凹曲線部から続けて断面が凹曲線でかつ同一直線方向の各凹曲線断面溝を並べて形成して、
前記各凹曲線断面溝のすくい角よりも前記各凹曲線断面溝同士の間の稜線のすくい角の方が大きく、
前記切屑排出溝が前記胴部の外周面に先端側から基部側に向かって螺旋状に形成されて、
前記すくい面が回転中心側から外周コーナ側に向かって前記すくい角が徐々に大きくなるねじれ面に形成されて、
前記各凹曲線断面溝同士の間の前記稜線および一番外周側の前記凹曲線断面溝とリーディングエッジの間の稜線のそれぞれのすくい角が前記回転中心側の前記稜線のすくい角よりも前記外周コーナ側の前記稜線のすくい角の方が大きく形成されて、
回転軸の軸方向に平行な方向の前記各凹曲線断面溝を並べて形成して、前記各凹曲線断面溝のすくい角がすべてゼロであることを特徴とするドリル。 By rotating around the axis and moving forward in the axial direction, the workpiece is cut with a cutting edge at the tip, and the chips are discharged from the chip discharge groove at the barrel, and the workpiece A drill for drilling an object in the axial direction,
The cutting edge comprises a line of intersection between a flank face comprising the end face of the tip and a rake face following the chip discharge groove,
Adjacent ends of the concave curve portions that have a shape in which two or more concave curve portions that are concave in the direction of rotation are arranged side by side on the flank and that are convex in the direction of rotation. In order to form a shape having one or more convex portions that are directly connected to each other, the rake face that continues from the intersecting line is continued from each concave curve portion of the intersecting line, and the cross section is a concave curve and each in the same linear direction. Forming the concave curved cross-section grooves side by side,
The rather the size towards the rake angle of the ridge line between the respective concave curve section grooves between than the rake angle of the concave curve section groove,
The chip discharge groove is formed in a spiral shape from the front end side to the base side on the outer peripheral surface of the barrel part,
The rake face is formed on a torsion surface in which the rake angle gradually increases from the rotation center side toward the outer peripheral corner side,
The rake angle of the ridge line between the concave curve cross-section grooves and the ridge line between the concave curve cross-section groove on the outermost circumferential side and the leading edge is greater than the rake angle of the ridge line on the rotation center side. The rake angle of the ridge line on the corner side is formed larger,
A drill characterized in that the concave curved cross-sectional grooves in a direction parallel to the axial direction of the rotation axis are formed side by side, and the rake angles of the concave curved cross-sectional grooves are all zero .

前記先端部の直径が０．５ｍｍ以下で、前記先端部に有する前記切れ刃の耐磨耗性が、多結晶焼結ダイヤモンド（ＰＣＤ）よりも低いことを特徴とする請求項１に記載のドリル。 The diameter of the said front-end | tip part is 0.5 mm or less, The abrasion resistance of the said cutting edge which has in the said front-end | tip part is lower than a polycrystalline sintered diamond (PCD) , The drill of Claim 1 characterized by the above-mentioned. .