JP2006095628A

JP2006095628A - Twist drill

Info

Publication number: JP2006095628A
Application number: JP2004283251A
Authority: JP
Inventors: Yoshihiro Kondo; 芳弘近藤
Original assignee: Hitachi Tool Engineering Ltd
Current assignee: Moldino Tool Engineering Ltd
Priority date: 2004-09-29
Filing date: 2004-09-29
Publication date: 2006-04-13

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tool, giving chip handling property to a cutting edge and increasing the area of a chip discharge groove as compared with a linear cutting edge by shaping the drill tip cutting edge like a recessed part, and stabilizing the tool behavior in the process of cutting by providing a margin on the heel side to solve the problem. <P>SOLUTION: In this drilling tool, the outer periphery of the tip part of the tool body rotated around an axis is provided with a pair of chip discharge grooves provided on the opposite sides with the axis interposed between them, and the cutting edge is provided at the tip of the wall surface facing the rotating direction of the chip discharge grooves. When the web thickness is W and the curvature of a substantially circular arc inscribing the cutting edge side groove bottom in the axial right-angled section is R1, a recessed cutting edge is formed with R1 ranging from 1.3 to 2.0, and another pair of margins are provided on the heel side to which a land part and a chip discharge groove are connected in the axial right-angled section of the drill tool. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本願発明は、ツイストドリルにおいて切削中の工具挙動が安定性するドリルに関する。 The present invention relates to a drill having stable tool behavior during cutting in a twist drill.

ドリルで穴加工を行う場合、刃先で生成された切り屑がドリル溝面と加工壁面に囲まれた空間を通り排出されるので切り屑の処理性が問題になる。また、工具剛性の弱さや、切刃のドリル中心からの距離による切削速度の変化、特に中心部では切削速度が０で押しつぶし加工になるために大きな切削抵抗が発生し、切削中の工具挙動が不安定となる。従来の直線状の切れ刃は切刃側溝底に内接する略円弧の曲率が大きいため切り屑を処理性の良い形状にカールさせる効果に乏しく、切り屑処理性の付与だけでは切削中の工具挙動を安定させるには十分とはいえない。更に、切刃側のみにマージンを設けた場合は工具挙動を安定させることが不十分であった。このような例として、特許文献１、２がある。 When drilling with a drill, chips generated at the cutting edge are discharged through the space surrounded by the drill groove surface and the processing wall surface, so chip disposal becomes a problem. Also, changes in cutting speed due to weak tool rigidity and the distance of the cutting edge from the drill center, especially at the center, the cutting speed is 0 and the crushing process causes a large cutting resistance. It becomes unstable. The conventional linear cutting edge has a large curvature of a substantially arc inscribed in the groove bottom groove, so the effect of curling the chip into a shape with good processability is poor. It is not enough to stabilize. Furthermore, when a margin is provided only on the cutting edge side, it is insufficient to stabilize the tool behavior. As such examples, there are Patent Documents 1 and 2.

特開昭６１−５８２４６号公報JP-A-61-58246 特開２００３−４８１１０号公報JP 2003-48110 A

本願発明は、切削中の工具挙動を安定させるため、凹状切刃とすることで直線状切刃と比較し、切刃に切り屑の処理性を付与するとともに切り屑排出溝の面積を大きくし、更に、ヒール側にマージンを設けることで切削中の工具挙動を安定させることで、このような問題を解決した工具を提供する。 In order to stabilize the tool behavior during cutting, the present invention provides a cutting edge to the cutting edge and increases the area of the chip discharge groove as compared with a linear cutting edge by using a concave cutting edge. Furthermore, by providing a margin on the heel side, the tool behavior during cutting is stabilized, thereby providing a tool that solves such a problem.

本願発明は、軸線回りに回転される工具本体の先端部外周に、一対の切屑排出溝が上記軸線を挟んで互いに反対側に設けられるとともに、これらの切屑排出溝の回転方向を向く壁面の先端には切刃が設けられてなる穴明け工具であって、心厚をＷ、軸直角断面における切刃側溝底に内接する略円弧の曲率をＲ１とするとき、Ｒ１＝（１．３〜２．０）Ｗの範囲で構成される凹状切刃を有し、該穴明け工具の軸直角断面視でランド部と切り屑排出溝のつながるヒール側にもう一対のマージンを設けたことを特長とするドリルであり、切れ刃を凹状とすることで切刃に切り屑処理性のよい形状にカールさせる効果を付与し、切り屑排出溝の面積を大きくし切り屑排出性を向上した。 According to the present invention, a pair of chip discharge grooves are provided on the outer periphery of the tip of the tool body rotated about an axis on opposite sides of the axis, and the tips of the wall surfaces facing the rotation direction of these chip discharge grooves Is a drilling tool provided with a cutting edge, where R1 = (1.3-2), where W is the thickness of the core, and R1 is the curvature of a substantially arc inscribed in the cutting edge side groove bottom in the cross section perpendicular to the axis. 0.0) W has a concave cutting edge configured in the range of W, and another pair of margins is provided on the heel side where the land portion and the chip discharge groove are connected in a cross-sectional view perpendicular to the axis of the drilling tool, The drill has a concave cutting edge, which gives the cutting blade the effect of curling it into a shape with good chip disposability, increasing the area of the chip discharge groove and improving the chip discharge.

本願発明により、切り屑の処理性が改善され、ヒール側マージンのガイドにより、切削中の工具挙動が安定し、穴加工の安定性を高めたドリルを提供することができた。 According to the present invention, it is possible to provide a drill in which the chip processing property is improved and the tool behavior during cutting is stabilized by the guide on the heel side margin, and the stability of drilling is enhanced.

ドリルで穴加工を行う場合、切り屑処理性の問題、剛性の弱さ、中心部での切削速度が０となるため押しつぶしの加工となり大きな切削抵抗が発生し、切削中の工具挙動が不安定となる。本願発明では、ドリル先端視において切刃形状を凹状として、切刃側溝底に内接する略円弧の曲率を小さくして切り屑の処理性を付与し、切り屑排出溝の面積を大きくするとともに、軸直角断面視でランド部と切削排出溝のつながるヒール側にもう一対のマージンを設け穴壁とのガイド部を設けた。Ｒ１がＷの１．３倍より小さい場合、切り屑排出溝容積を十分に確保することができないため切刃側の溝底部で切り屑が詰まる傾向となり排出性が阻害される。Ｒ１がＷの２．０倍より大きい場合切り屑をカールさせる効果に乏しくなり切り屑のカール半径が大きくなり溝内に切り屑が詰まる傾向となるため、Ｒ１＝（１．３〜２．０）Ｗの範囲とした。
軸直角断面視でランド部と切削排出溝のつながるヒール側にもう一対のマージンを設けマージン巾を規定することで、穴壁で工具を支えるガイド部を増やして穴壁でドリルを支持することで切削抵抗の増加を防ぎ、切削中の工具挙動を安定させることができた。
ヒール側のマージンを設ける位置は、切刃コーナーよりヒール側に向かって７５°より切刃コーナーに近い位置や、１０５°より遠い位置ではガイドの効果が小さくなるため７５°〜１０５°の範囲とした。
ヒール側のマージン巾はドリル直径の３．０％より狭い場合十分なガイド効果を得ることができず、６．５％より広い場合穴壁との接触面積が増大し抵抗が大きくなりドリルの挙動が不安定となるため、３．０％〜６．５％の範囲とした。
該ドリルにクーラントホールを設けてクーラントとして油性切削油、水溶性切削油、ミスト及びエアー等を送ることにより、切削によって生ずる熱の冷却と、潤滑性を高め切屑の排出をよりスムーズに行うことが出来る。
ハイス基材或いは超硬基材の表面に硬質皮膜及び潤滑性膜を、スパッタリング法、プラズマ化学蒸着法、イオン誘導型アーク放電式イオンプレーティング法の何れかもしくはその組合せにより被覆することで、切削寿命、切削作業速度の向上は図れるが、コーティングを施さないものにおいても切削寿命、切削作業速度の低下以外は、切削性能は変わらないものである。 When drilling with a drill, there is a problem with chip disposal, weak rigidity, and the cutting speed at the center is 0, which results in crushing and large cutting resistance, resulting in unstable tool behavior during cutting. It becomes. In the present invention, the cutting edge shape is concave in the drill tip view, the curvature of the substantially arc inscribed in the cutting edge side groove bottom is reduced to give chip processing performance, and the area of the chip discharge groove is increased, Another pair of margins were provided on the heel side where the land portion and the cutting discharge groove were connected in a cross-sectional view perpendicular to the axis, and a guide portion with the hole wall was provided. When R1 is smaller than 1.3 times W, the chip discharge groove volume cannot be secured sufficiently, and the chip tends to be clogged at the groove bottom on the cutting edge side, and the discharge performance is hindered. When R1 is larger than 2.0 times W, the effect of curling the chips becomes poor, the curl radius of the chips becomes large, and the chips tend to be clogged in the groove. Therefore, R1 = (1.3 to 2.0 ) W range.
By providing another pair of margins on the heel side where the land and cutting discharge groove are connected in a cross-sectional view perpendicular to the axis and defining the margin width, the guide wall supporting the tool on the hole wall is increased and the drill is supported on the hole wall. The increase in cutting resistance was prevented, and the tool behavior during cutting was stabilized.
The position where the margin on the heel side is provided is in the range of 75 ° to 105 ° because the effect of the guide is reduced at a position closer to the cutting edge corner than 75 ° from the cutting edge corner toward the heel side, or at a position farther than 105 °. did.
If the margin width on the heel side is narrower than 3.0% of the drill diameter, a sufficient guide effect cannot be obtained. If the margin width is larger than 6.5%, the contact area with the hole wall increases and the resistance increases and the behavior of the drill increases. Is unstable, so the range was 3.0% to 6.5%.
By providing a coolant hole in the drill and sending oil-based cutting oil, water-soluble cutting oil, mist, air, etc. as coolant, it is possible to cool the heat generated by cutting and improve lubricity and discharge chips more smoothly. I can do it.
By coating the surface of a high-speed substrate or carbide substrate with a hard film and a lubricating film by sputtering method, plasma chemical vapor deposition method, ion induction type arc discharge ion plating method or a combination thereof, cutting is performed. Although the life and cutting work speed can be improved, the cutting performance is not changed except for the reduction of the cutting life and cutting work speed even when the coating is not applied.

（実施例１）
超硬ドリルの形状を、ドリル径＝６．０ｍｍ、溝長＝４５ｍｍ、全長＝１００ｍｍ、捩れ角＝３０°、ヒール側マージンの位置を９０°、クーラントホール付き、を用いて、切刃側溝底に内接する略円弧の曲率Ｒ１を、比較例１、１．２Ｗ、本発明例２、同１．３Ｗ、本発明例３、同１．６Ｗ、本発明例４、同２．０Ｗ、比較例５、同２．１Ｗ、の５試料コーティング超硬ドリルを製作した。コーティングはＴｉＡｌＮをイオン誘導型アーク放電式イオンプレーティング法とスパッタリング法を組み合わせて施した。
上記各３本を、切削速度＝１００ｍ／ｍｉｎ、１回転送り＝０．１５ｍｍ／ｒｅｖ、被削材は一般の機械部品等に使用される一般鋼や合金鋼等のうちＳ５０Ｃ（２２０〜２８０ＨＢ）、クーラントホールを通して水溶性切削液を供給、穴深さ１８ｍｍの貫通穴を加工する条件で、ＢＴ４０番の縦型マシニングセンターで１０穴の加工を行い、切削状況を確認した。結果、機械主軸負荷が比較例１はＲ１が小さいため切り屑が詰まる傾向に成り５〜１５％、本発明例１は４〜６％、本発明例２は１〜２％、本発明例３は３〜５％、比較例２はＲ１が大きいため切り屑をカールさせる効果が小さく処理性が悪いため切り屑が詰まる傾向になり５〜１２％の変動幅となった。 Example 1
Carbide drill shape, drill diameter = 6.0mm, groove length = 45mm, total length = 100mm, twist angle = 30 °, heel side margin position 90 °, with coolant hole, cutting edge side groove bottom The curvature R1 of the substantially arc inscribed in the following is Comparative Example 1, 1.2W, Invention Example 2, 1.3W, Invention Example 3, 1.6W, Invention Example 4, 2.0W, Comparative Example 5 and 2.1 W, 5 sample coated carbide drills were manufactured. The coating was performed by combining TiAlN with an ion induction arc discharge ion plating method and a sputtering method.
Three of each of the above, cutting speed = 100 m / min, 1 rotation feed = 0.15 mm / rev, work material is S50C (220 to 280HB) among general steel and alloy steel used for general machine parts and the like Under the conditions of supplying a water-soluble cutting fluid through the coolant hole and machining a through hole with a hole depth of 18 mm, 10 holes were machined in a vertical machining center of BT40, and the cutting situation was confirmed. As a result, the mechanical spindle load in Comparative Example 1 tends to be clogged because R1 is small, 5 to 15%, Invention Example 1 is 4 to 6%, Invention Example 2 is 1 to 2%, Invention Example 3 3 to 5%, and Comparative Example 2 has a large R1, so the effect of curling the chips is small and the processability is poor, so the chips tend to become clogged, and the fluctuation range is 5 to 12%.

（実施例２）
本発明例３の形状でさらに、マージンの位置を、工具中心を通り両切刃コーナーを結んだ直線に対し、切刃コーナーよりヒール側に向かって、比較例６、７２°、本発明例７、７５°、本発明例８、８０°、本発明例９、９０°、本発明例１０、１００°、本発明例１１、１０５°、比較例１２、１０７°の位置に設けたものと、比較例１３として切刃側のみにマージンを設けたものに、スパッタリング法によりＴｉＡｌＮコーティングを施したクーラントホール付き超硬ドリルを製作した。上記各試料３本を、被削材をＳＣＭ４４０（ＨＢ２８０〜３３０）、その他の切削諸元は実施例１と同じ諸元で穴加工を行い、５００穴加工時の刃先を確認した。その結果、比較例６は３本中２本に微小なチッピング、本発明例７〜１１は正常摩耗、比較例１２は３本中１本に微小なチッピング、比較例１３は３本中２本に微小なチッピングを観察した。更に、ドリル表面を観察したところ、コーティング表面が平滑で切り屑処理性が良好であり、併せて切り屑が金属光沢を有し、焼け色がなかった。 (Example 2)
In the shape of Example 3 of the present invention, the margin position is set to Comparative Example 6, 72 ° from the edge of the cutting edge toward the heel side with respect to the straight line passing through the center of the tool and connecting the cutting edge corners, and Example 7 of the invention. , 75 °, Invention Example 8, 80 °, Invention Example 9, 90 °, Invention Example 10, 100 °, Invention Example 11, 105 °, Comparative Example 12, 107 °, As a comparative example 13, a carbide drill with a coolant hole in which a margin was provided only on the cutting edge side and TiAlN coating was applied by a sputtering method was manufactured. The above three samples were subjected to hole machining with SCM440 (HB280-330) as the work material and the same other specifications as in Example 1, and the cutting edge at the time of 500 hole machining was confirmed. As a result, Comparative Example 6 has a minute chipping in two of three, Invention Examples 7 to 11 have normal wear, Comparative Example 12 has a minute chipping in one of three, and Comparative Example 13 has two of three. Minute chipping was observed. Furthermore, when the drill surface was observed, the coating surface was smooth and the chip disposal was good, and the chips had a metallic luster and there was no burnt color.

（実施例３）
本発明例３及び９の形状で、マージンの巾を工具直径の、比較例１４、２．７％、本発明例１５、３．０％、本発明例１６、４．０％、本発明例１７、６．０％、本発明例１８、６．５％、比較例１９、６．８％とし、プラズマ化学蒸着法によりＴｉＡｌＮコーティングを施した超硬ドリルを製作した。上記各試料３本を、被削材をＳＳ４００（ＨＢ１８０〜２２０）、その他の切削諸元は実施例１と同じ諸元で穴加工を行い、１０００穴加工時の刃先を観察した。その結果、比較例１４は３本中１本に微小なチッピングを、本発明例１５〜１８は正常摩耗、比較例１９は３本中１本に微小なチッピングが観察された。 (Example 3)
Comparative Examples 14, 2.7%, Invention Examples 15, 3.0%, Invention Examples 16, 4.0%, Invention Examples with the shapes of Invention Examples 3 and 9 and the margin width of the tool diameter. Carbide drills with TiAlN coating were produced by plasma chemical vapor deposition using 17, 6.0%, Invention Examples 18, 6.5%, and Comparative Examples 19, 6.8%. For each of the three samples, the work material was SS400 (HB180-220), the other cutting parameters were drilled with the same specifications as in Example 1, and the edge of the 1000 holes was observed. As a result, in Comparative Example 14, minute chipping was observed in one of the three samples, Normal Wear was observed in Invention Examples 15 to 18, and Minute Chipping was observed in one in three samples of Comparative Example 19.

図１は本発明例のドリルの軸直角断面を示す。FIG. 1 shows a cross section perpendicular to the axis of a drill according to an embodiment of the present invention. 図２は本発明例のドリルのＷマージンを示す。FIG. 2 shows the W margin of the drill of the present invention.

Explanation of symbols

１：心厚に相当する略円弧
２：刃側溝底
３：刃側溝底に内接する略円弧
４：軸心を通り両切刃コーナーを結ぶ線
５：工具軸心とヒール側マージンを結ぶ線
６：ヒール側マージンの位置を示す角度
７：ヒール側のマージン巾
Ｒ１：切刃側溝底に内接する略円弧の半径
Ｗ：ドリル心厚 1: substantially arc corresponding to core thickness 2: blade-side groove bottom 3: generally arc inscribed in the blade-side groove bottom 4: line connecting both cutting edge corners through the axis 5: line connecting the tool axis and the heel side margin 6 : Angle indicating the position of the heel side margin 7: Margin width on the heel side R1: Radius of a substantially arc inscribed in the bottom of the groove on the cutting edge side W: Thickness of the drill core

Claims

A pair of chip discharge grooves are provided on the outer periphery of the tip of the tool body rotated about the axis on opposite sides of the axis, and a cutting blade is provided at the end of the wall facing the rotation direction of these chip discharge grooves. , Where R1 = (1.3 to 2.0) W, where W is the core thickness and R1 is the curvature of the substantially arc inscribed in the cutting edge side groove bottom in the cross section perpendicular to the axis. And a pair of margins provided on the heel side where the land portion and the chip discharge groove are connected in a cross-sectional view perpendicular to the axis of the drilling tool.

2. The drill according to claim 1, wherein the margin on the heel portion side is formed at a position of 75 to 105 ° from the cutting edge corner toward the heel side with respect to a straight line passing through the center of the tool and connecting both cutting edge corners. A drill characterized by

The twist drill according to claim 1 or 2, wherein a width of the margin portion is formed in a range of 3.0% to 6.5% of a drill diameter.

The drill according to any one of claims 1 to 3, wherein a coolant hole is provided in the drill.

5. The drill according to claim 1, wherein the drill is coated with a hard film and / or a lubricating film.