JPH10249623A - Ball end mill - Google Patents

Ball end mill

Info

Publication number
JPH10249623A
JPH10249623A JP5661097A JP5661097A JPH10249623A JP H10249623 A JPH10249623 A JP H10249623A JP 5661097 A JP5661097 A JP 5661097A JP 5661097 A JP5661097 A JP 5661097A JP H10249623 A JPH10249623 A JP H10249623A
Authority
JP
Japan
Prior art keywords
axis
cutting edge
cutting
end mill
ball end
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.)
Granted
Application number
JP5661097A
Other languages
Japanese (ja)
Other versions
JP3189725B2 (en
Inventor
Katsuhiko Sato
勝彦 佐藤
Takahiro Sato
隆広 佐藤
Takeshi Hirose
武史 広瀬
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Materials Corp
Original Assignee
Mitsubishi Materials Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Mitsubishi Materials Corp filed Critical Mitsubishi Materials Corp
Priority to JP05661097A priority Critical patent/JP3189725B2/en
Publication of JPH10249623A publication Critical patent/JPH10249623A/en
Application granted granted Critical
Publication of JP3189725B2 publication Critical patent/JP3189725B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23C—MILLING
    • B23C5/00—Milling-cutters
    • B23C5/02—Milling-cutters characterised by the shape of the cutter
    • B23C5/10—Shank-type cutters, i.e. with an integral shaft
    • B23C5/1009—Ball nose end mills

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Milling Processes (AREA)

Abstract

PROBLEM TO BE SOLVED: To enhance the accuracy of surface processing around a rotating axial line while a cutting blade is being prevented from being defective. SOLUTION: At the tip end part 21a of a tool main body with respect to imaginary X-Y axes perpendicularly intersected with each other where the cross point of them is laid over the rotating axial line of the tool main body, a main cutting blade 24 and an auxiliary cutting blade 25 are positioned at both of sides while the Y axis is held in between, and are extended in the radial direction along the Y axis so as to allow their core centers to be raised up. The main cutting blade 24 is extended to a position across the X axis from its outer circumferential side, and the auxiliary cutting blade 25 is extended to a position just this side not arriving at the X axis. A distance (n) in the Y axis direction between the end parts 24a and 25a of both the cutting blades, shall be 0<<=0.3D, where D represents the outer diameter at the tip end of the tool main body.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は、ボールエンドミル
に関する。[0001] The present invention relates to a ball end mill.

【０００２】[0002]

【従来の技術】従来、ソリッドタイプのボールエンドミ
ルの一例として、実公昭５８−５２０１１号公報に示す
ものがある。このボールエンドミル１を図５に示す先端
面図で説明すると、工具本体２の回転軸線Ｏに対向して
その外周面に一対の切屑排出溝３がねじれ溝状に形成さ
れ、工具本体２の略半球状先端部２ａにおいて、各切屑
排出溝３の回転方向を向く壁面の先端部に主切刃５と副
切刃６とが形成されている。主切刃５は半球状の先端部
２ａを外周側から回転軸線Ｏの位置まで延在しており、
副切刃６は外周側から回転軸線Ｏに対して若干の距離を
残して終わっており、主切刃５と副切刃６との間に切欠
部７が形成されている。しかしながら、回転軸線Ｏ付近
では工具本体２の周速が低いために、回転軸線Ｏの位置
まで延在する主切刃５の先端部が欠損しやすく、主切刃
５の寿命が非常に短いという欠点がある。2. Description of the Related Art Conventionally, as an example of a solid type ball end mill, there is one disclosed in Japanese Utility Model Publication No. 58-52011. The ball end mill 1 will be described with reference to a front end view shown in FIG. 5. A pair of chip discharge grooves 3 are formed in the outer peripheral surface of the ball end mill 1 in the shape of a twist groove facing the rotation axis O of the tool body 2. A main cutting edge 5 and a sub cutting edge 6 are formed at the tip of the wall surface of the hemispherical tip 2a facing the rotation direction of each chip discharge groove 3. The main cutting edge 5 extends the hemispherical tip 2a from the outer peripheral side to the position of the rotation axis O,
The minor cutting edge 6 ends with a slight distance from the outer peripheral side to the rotation axis O, and a notch 7 is formed between the major cutting edge 5 and the minor cutting edge 6. However, since the peripheral speed of the tool main body 2 is low in the vicinity of the rotation axis O, the tip of the main cutting edge 5 extending to the position of the rotation axis O is easily damaged, and the life of the main cutting edge 5 is very short. There are drawbacks.

【０００３】これに対して、例えば図６及び図７に示す
ボールエンドミル８が提案されている。このボールエン
ドミル８では、一対の切屑排出溝９、９が回転軸線に沿
って螺旋状に形成され、その回転方向を向く壁面の稜線
の先端部にそれぞれ切刃１０、１１が設けられている。
図７に示す先端面図において、その交点が回転軸線Ｏ上
に位置して互いに直交するＸ−Ｙ軸を仮想的に描いたと
して、一対の切刃１０、１１はそれぞれ芯上がりに形成
され、Ｙ軸を挟んでその両側に互いにほぼ等距離の位置
にあるものとする。しかも各切刃１０、１１は回転軸線
Ｏに対してほぼ回転対称とされ、外周側からＹ軸に沿っ
て径方向に延びてＸ軸の位置まで延在している。そし
て、両切刃１０、１１の端部はＸ軸上での距離がｍとさ
れている。２つの切刃１０、１１をこのように構成すれ
ば、いずれの切刃１０、１１も回転中心Ｏから外れてい
るので切刃寿命が長くなる。On the other hand, for example, a ball end mill 8 shown in FIGS. 6 and 7 has been proposed. In this ball end mill 8, a pair of chip discharge grooves 9, 9 are formed in a spiral shape along the rotation axis, and cutting edges 10, 11 are provided at the tips of the ridges of the wall faces in the direction of rotation.
In the front end view shown in FIG. 7, assuming that the intersection point is located on the rotation axis O and virtually draws the XY axes orthogonal to each other, the pair of cutting blades 10 and 11 are respectively formed so as to be centered, It is assumed that both sides of the Y-axis are substantially equidistant from each other. Moreover, each of the cutting blades 10 and 11 is substantially rotationally symmetric with respect to the rotation axis O, extends radially along the Y axis from the outer peripheral side, and extends to the position of the X axis. The distance between the ends of the cutting edges 10 and 11 on the X axis is m. If the two cutting blades 10 and 11 are configured in this manner, each of the cutting blades 10 and 11 is off the center of rotation O, so that the life of the cutting blades is extended.

【０００４】[0004]

【発明が解決しようとする課題】しかしながら、このよ
うな従来のボールエンドミル８では、両切刃１０、１１
で挟まれる心厚部１２の幅が（距離ｍ）が小さいため
に、心厚部１２で切刃１０、１１が欠損し易いという欠
点がある。距離ｍを大きくして心厚部１２を厚くする
と、ボールエンドミル８の先端部における削り残し部が
大きくなり加工能力が低下するという欠点が生じる。し
かも、切削領域の中心部を２枚の切刃１０、１１で切削
することになるから、切刃１０、１１の振れのために回
転軸線Ｏ周りの中心部での加工面精度が低下するという
欠点もある。本発明は、このような実情に鑑みて、切刃
の欠損を抑えて加工面精度を向上できるようにしたボー
ルエンドミルを提供することを目的とする。However, in such a conventional ball end mill 8, both cutting edges 10, 11 are used.
Since the width (distance m) of the core portion 12 sandwiched between the core portions 12 is small, there is a disadvantage that the cutting blades 10 and 11 are easily broken at the core portion 12. If the thickness m is increased by increasing the distance m, the uncut portion at the tip of the ball end mill 8 becomes large, resulting in a disadvantage that the machining ability is reduced. In addition, since the center of the cutting area is cut by the two cutting blades 10 and 11, the accuracy of the processing surface at the center around the rotation axis O is reduced due to the run-out of the cutting blades 10 and 11. There are drawbacks. SUMMARY OF THE INVENTION In view of such circumstances, an object of the present invention is to provide a ball end mill capable of suppressing a loss of a cutting edge and improving a machining surface accuracy.

【０００５】[0005]

【課題を解決するための手段】本発明に係るボールエン
ドミルは、略半球状の先端部を有する工具本体に一対の
切屑排出溝が対向して形成され、これら切屑排出溝の先
端にそれぞれ切刃が設けられたボールエンドミルにおい
て、工具本体の先端面視で、その交点が工具本体の回転
軸線上にあって互いに直交する仮想のＸ−Ｙ軸に対し
て、２つの切刃がＹ軸を挟んで両側に位置して径方向に
延びており、一方の切刃は芯上がりとされて外周側から
少なくともＸ軸まで延在し、他方の切刃は外周側からＸ
軸に至らない位置まで延在していることを特徴とする。
切削に際して、一方の切刃は芯上がりとされ他方の切刃
はＸ軸に至らないから、回転軸線Ｏ近傍に切刃がなくこ
の領域の切刃が欠損することを防止でき、しかも両切刃
はＸ軸方向に対向していないので、両切刃間の狭い芯厚
部が形成されず、この点でも切刃の欠損を防止できる。
しかも、一方の切刃は少なくともＸ軸まで延在するため
に両切刃間の凹部の領域の削り残しを工具本体の先端部
で押しつぶすことができる。In a ball end mill according to the present invention, a pair of chip discharge grooves are formed to face a tool body having a substantially hemispherical tip, and a cutting edge is provided at each of the ends of the chip discharge grooves. In the ball end mill provided with, two cutting edges sandwich the Y axis with respect to a virtual XY axis whose intersection is on the rotation axis of the tool main body and is orthogonal to each other when viewed from the front end surface of the tool main body. And one of the cutting blades extends up to at least the X-axis from the outer peripheral side, and the other cutting blade extends from the outer peripheral side to X.
It extends to a position not reaching the axis.
At the time of cutting, one of the cutting edges is raised and the other cutting edge does not reach the X-axis, so that there is no cutting edge near the rotation axis O, and it is possible to prevent the cutting edge in this region from being lost. Are not opposed to each other in the X-axis direction, a narrow core portion between the two cutting edges is not formed, and in this regard, the cutting edge can be prevented from being damaged.
In addition, since one of the cutting edges extends at least up to the X-axis, the uncut portion in the region of the concave portion between the two cutting edges can be crushed by the tip of the tool body.

【０００６】また、２つの切刃の端部間のＹ軸方向の距
離ｎは、工具本体の先端部の外径をＤとして、０＜ｎ≦
０．３Ｄとされていてもよい。両切刃の欠損を抑制でき
る上に、中心付近が一方の切刃のみで切削されるために
この切刃に過大な切削抵抗をかけることなく加工精度を
向上できる。尚、他方の切刃も芯上がりとして、両切刃
をほぼ回転対称の位置に配設してもよい。The distance n between the ends of the two cutting edges in the Y-axis direction is 0 <n ≦, where D is the outer diameter of the tip of the tool body.
It may be 0.3D. In addition to suppressing the loss of both cutting edges, the vicinity of the center is cut by only one of the cutting edges, so that machining accuracy can be improved without applying excessive cutting resistance to the cutting edges. Incidentally, the other cutting edge may also be set up at the center, and both cutting edges may be arranged at substantially rotationally symmetric positions.

【０００７】[0007]

【発明の実施の形態】以下、本発明の実施の形態を図１
及び図２により説明する。図１は実施の形態によるボー
ルエンドミルの刃部の側面図、図２は図１に示すボール
エンドミルの先端面図である。図１に示すボールエンド
ミル２０において、工具本体２１の先端側の刃部２２の
外周面には回転軸線Ｏに沿って断面視略Ｖ字形の一対の
切屑排出溝２３、２３が対向して螺旋状に形成されてい
る。そして、工具本体２１の先端部２１ａは略半球状に
形成されており、各切屑排出溝２３の回転方向を向く壁
面２３ａの先端側の稜線は、それぞれ主切刃２４と副切
刃２５とされ、外周側から回転軸線Ｏ付近に向けて径方
向に延びている。主切刃２４及び副切刃２５に接続され
る切屑排出溝２３の壁面２３ａはすくい面とされ、先端
部２１ａの表面は逃げ面とされている。FIG. 1 is a block diagram showing an embodiment of the present invention.
And FIG. FIG. 1 is a side view of a blade portion of the ball end mill according to the embodiment, and FIG. 2 is a front end view of the ball end mill shown in FIG. In a ball end mill 20 shown in FIG. 1, a pair of chip discharge grooves 23 having a substantially V-shaped cross section are opposed to each other on the outer peripheral surface of a blade portion 22 on the distal end side of a tool main body 21 along a rotation axis O to form a spiral. Is formed. The tip portion 21a of the tool body 21 is formed in a substantially hemispherical shape, and the ridge lines on the tip side of the wall surface 23a facing the rotation direction of each chip discharge groove 23 are a main cutting edge 24 and a sub cutting edge 25, respectively. , Extending radially from the outer peripheral side toward the vicinity of the rotation axis O. The wall surface 23a of the chip discharge groove 23 connected to the main cutting edge 24 and the sub cutting edge 25 is a rake face, and the surface of the tip 21a is a flank face.

【０００８】図２に示す工具本体２１の先端部２１ａに
おいて、互いに直交してその交点が回転軸線Ｏ上に位置
するＸ−Ｙ軸を仮想的に描いたとして、２つの切刃２
４、２５はＹ軸を挟んで両側に位置してＹ軸に対して互
いに最短に近い（又は最短の）等距離の位置にあり、し
かも回転軸線Ｏに対してほぼ回転対称の位置にあるもの
とする。各切刃２４，２５はそれぞれ芯上がりに形成さ
れ、主切刃２４は外周側からＹ軸に沿って径方向に延び
てＸ軸上またはこれを越えた位置（図２ではＸ軸を若干
越えた位置）にその先端部２４ａがあるものとする。ま
た、副切刃２５は主切刃２４の反対側の外周側からＹ軸
に沿って径方向に延びてＸ軸に到達しない位置にその先
端部２５ａがあるものとする。そのため、両先端部２４
ａ、２５ａはＸ軸方向に対向しておらず、主切刃２４の
先端部２４ａと副切刃２５の先端部２５ａとの間に凹部
２６が形成されている。ここで、主切刃２４と副切刃２
５を芯上がりとすることで、切刃が回転軸線Ｏに至らな
いので回転軸線Ｏ近傍の低速領域における切刃２４、２
５の欠損を防止できる。主切刃２４が少なくともＸ軸ま
で延びていることで、切削時の凹部２６による削り残し
を先端部２１ａで押しつぶすことができる。At the tip 21a of the tool body 21 shown in FIG. 2, the two cutting edges 2 are assumed to depict an XY axis that is orthogonal to each other and whose intersection is located on the rotation axis O.
Reference numerals 4 and 25 are located on both sides of the Y axis, are located at the shortest (or shortest) equidistant positions with respect to the Y axis, and are substantially rotationally symmetric with respect to the rotation axis O. And Each of the cutting blades 24 and 25 is formed so as to be above the center, and the main cutting blade 24 extends radially from the outer peripheral side along the Y-axis to a position above or beyond the X-axis (in FIG. 2, slightly above the X-axis). (A position). The sub-cutting edge 25 extends in the radial direction along the Y-axis from the outer peripheral side opposite to the main cutting edge 24 and has a tip end portion 25a at a position where it does not reach the X-axis. Therefore, both tip portions 24
a and 25a do not face each other in the X-axis direction, and a concave portion 26 is formed between the distal end portion 24a of the main cutting edge 24 and the distal end portion 25a of the sub cutting edge 25. Here, the main cutting edge 24 and the sub cutting edge 2
Since the cutting edge does not reach the rotation axis O by setting the center of the cutting edge 5 to the center, the cutting blades 24, 2 and 2 in the low speed region near the rotation axis O are provided.
5 can be prevented. Since the main cutting edge 24 extends at least to the X-axis, the uncut portion due to the concave portion 26 at the time of cutting can be crushed by the distal end portion 21a.

【０００９】そして、Ｙ軸方向における主切刃２４と副
切刃２５の各先端部２４ａ、２５ａ間の距離ｎは、工具
本体２１の先端部２１ａにおける切刃２４、２５の外径
寸法をＤとした時に、 ０＜ｎ≦０．３Ｄ の範囲にあるものとする。ここで、ｎが０以下だと主切
刃２４と副切刃２５の各先端部２４ａ、２５ａがＸ軸方
向に対向して、先端部２４ａと２５ａの距離（芯厚部）
がｍ程度に小さくなり、主切刃２４及び副切刃２５が欠
損しやすいという欠点が生じ、ｎが０を越えることで各
先端部２４ａ、２５ａがＹ軸方向にずれてＸ軸方向に対
向しなくなるために切刃が欠損しにくくなる。また、ｎ
が０．３Ｄを越えると主切刃２４のみの１枚刃での回転
中心領域での切削範囲が広くなり、切削抵抗が大きくな
る欠点が生じる。The distance n between the tips 24a, 25a of the main cutting edge 24 and the sub-cutting edge 25 in the Y-axis direction is determined by the outer diameter of the cutting edges 24, 25 at the tip 21a of the tool body 21. In this case, it is assumed that 0 <n ≦ 0.3D. Here, if n is 0 or less, the tip portions 24a and 25a of the main cutting edge 24 and the sub cutting edge 25 face each other in the X-axis direction, and the distance between the tip portions 24a and 25a (core thickness portion).
Is reduced to about m, and the main cutting edge 24 and the sub cutting edge 25 are easily damaged. When n exceeds 0, the tips 24a and 25a are displaced in the Y-axis direction and face each other in the X-axis direction. The cutting edge is less likely to be lost. Also, n
Exceeds 0.3D, the cutting range in the rotation center region with only one cutting edge of the main cutting edge 24 is widened, resulting in a disadvantage that the cutting resistance is increased.

【００１０】また、Ｘ軸方向における主切刃２４と副切
刃２５の各先端部２４ａ、２５ａ間の距離ｍは、 ０＜ｍ≦０．２Ｄ の範囲にあることが好ましい。ここで、ｍが０以下だと
先端部２４ａ、２５ａ間の強度が小さくなり、０．２Ｄ
を越えると加工面（凹曲面）の精度が低下し、切削抵抗
が大きくなる欠点がある。It is preferable that the distance m between the leading ends 24a and 25a of the main cutting edge 24 and the sub cutting edge 25 in the X-axis direction is in the range of 0 <m ≦ 0.2D. Here, if m is 0 or less, the strength between the tip portions 24a and 25a becomes small, and 0.2D
If it exceeds, there is a disadvantage that the precision of the processed surface (concave curved surface) is reduced and the cutting resistance is increased.

【００１１】本実施の形態は上述のように構成されてい
るから、切削に際して、主切刃２４と副切刃２５がいず
れも芯上がりで副切刃２４はＸ軸に到達していないため
に、回転軸線Ｏ近傍の低速領域の切削によって切刃が欠
損することを防止できる。しかも主切刃２４は少なくと
もＸ軸まで延在するために、主切刃２４と副切刃２５と
の間の凹部２６部分の削り残しを工具本体２１の先端部
２１ａで押しつぶすことができる。また主切刃２４と副
切刃２５のＹ軸方向の距離ｎを０＜ｎ≦０．３Ｄとした
ことで、上述のように主切刃２４と副切刃２５の欠損を
抑制できる上に、回転中心付近が主切刃２４のみで切削
されるために主切刃２４に過大な切削抵抗をかけること
なく加工精度を向上できる。Since the present embodiment is configured as described above, the main cutting edge 24 and the sub-cutting edge 25 are both centered at the time of cutting, and the sub-cutting edge 24 has not reached the X axis. In addition, it is possible to prevent the cutting edge from being broken by cutting in the low-speed region near the rotation axis O. Moreover, since the main cutting edge 24 extends at least up to the X-axis, the uncut portion of the concave portion 26 between the main cutting edge 24 and the sub cutting edge 25 can be crushed by the tip 21 a of the tool body 21. In addition, by setting the distance n between the main cutting edge 24 and the sub cutting edge 25 in the Y-axis direction to be 0 <n ≦ 0.3D, it is possible to suppress the loss of the main cutting edge 24 and the sub cutting edge 25 as described above. Since the vicinity of the rotation center is cut only by the main cutting edge 24, the processing accuracy can be improved without applying excessive cutting resistance to the main cutting edge 24.

【００１２】次に実施の形態によるボールエンドミル２
０と、図６及び７に示す従来のボールエンドミル８を用
いて行った切削試験について説明する。 試験条件 被削材：ＳＫＤ１１（ダイス鋼：４６ＨＲＣ） ホルダ：ＭＳＴコーポレーション、ＢＴ４０−ＣＴＨ１
０−９０（精密コレット使用） 切削条件：切削速度Ｖ（max）＝１０１ｍ／min 回転数Ｎ＝８０００min-1： １刃当りの送り速度Ｓｚ：０．０５ｍｍ／刃 テーブル送り速度Ｕ＝８００ｍｍ／min 軸方向切込み深さＡｄ＝１ｍｍ 一列のピッチＰｆ＝１ｍｍ ダウンカット、ドライ（エアーブロー） 使用機械：ＯＫＫ、立形マシニングセンタ、ＰＣＶ−４
０（３．７／５．５ｋＷ） 切削長：８．５ｍNext, a ball end mill 2 according to an embodiment
0 and cutting tests performed using the conventional ball end mill 8 shown in FIGS. 6 and 7 will be described. Test conditions Work material: SKD11 (die steel: 46HRC) Holder: MST Corporation, BT40-CTH1
0-90 (using a precision collet) Cutting conditions: Cutting speed V (max) = 101 m / min Rotation speed N = 8000 min -1 : Feed speed per tooth Sz: 0.05 mm / tooth Table feed speed U = 800 mm / min Axial depth of cut Ad = 1mm Pitch of row Pf = 1mm Down cut, dry (air blow) Machine used: OKK, vertical machining center, PCV-4
0 (3.7 / 5.5kW) Cutting length: 8.5m

【００１３】以上の試験条件のもとで切削試験を行った
結果、それぞれの工具の回転軸線Ｏ周りの加工面におけ
る仕上げ面粗さの測定結果が図３及び図４に示すチャー
トとして得られた。本実施の形態のボールエンドミル２
０による仕上げ面粗さの測定結果は図３に示され、従来
のボールエンドミル８による仕上げ面粗さの測定結果は
図４に示されている。本実施の形態によるものの方が均
一で精度の良い仕上げ面粗さが得られたことが理解でき
る。As a result of the cutting test performed under the above test conditions, the measurement results of the finished surface roughness of the processed surface around the rotation axis O of each tool were obtained as charts shown in FIGS. . Ball end mill 2 of the present embodiment
FIG. 3 shows the measurement result of the finished surface roughness by using a conventional ball end mill 8, and FIG. 4 shows the measurement result of the finished surface roughness by using the conventional ball end mill 8. It can be understood that the finish according to the present embodiment has a more uniform and accurate finished surface roughness.

【００１４】尚、上述の実施の形態では、２枚刃のボー
ルエンドミルについて説明したが、例えば４枚等、３枚
以上の切刃を備えていてもよい。また、副切刃２５は芯
上がりとしたが、回転軸線Ｏまで到達していないから芯
上がりでなくてもよい。In the above embodiment, the ball end mill having two blades has been described. However, three or more cutting blades, for example, four blades may be provided. In addition, although the sub cutting edge 25 is set to be centered, it does not have to be centered because it does not reach the rotation axis O.

【００１５】[0015]

【発明の効果】上述のように、本発明に係るボールエン
ドミルは、工具本体の先端面視で、その交点が工具本体
の回転軸線上にあって互いに直交する仮想のＸ−Ｙ軸に
対して、２つの切刃がＹ軸を挟んで両側に位置して径方
向に延びており、一方の切刃は芯上がりとされて外周側
から少なくともＸ軸まで延在し、他方の切刃は外周側か
らＸ軸に至らない位置まで延在しているから、工具本体
の先端部の回転軸線Ｏ近傍に切刃がなくこの領域の切刃
が欠損することを防止でき、しかも両切刃はＸ軸方向に
対向していないので、両切刃で挟む狭い芯厚部が形成さ
れず、この点でも切刃の欠損を防止できる。しかも、一
方の切刃は少なくともＸ軸まで延在するために両切刃間
の領域の削り残しを工具本体の先端部で押しつぶすこと
ができる。また、２つの切刃の端部間のＹ軸方向の距離
ｎは、工具本体の先端部の外径をＤとして、０＜ｎ≦
０．３Ｄとされているから、両切刃の欠損を抑制できる
上に、中心付近が一方の切刃のみで切削されるために一
方の切刃に過大な切削抵抗をかけることなく加工精度を
向上できる。As described above, in the ball end mill according to the present invention, when viewed from the front end surface of the tool main body, the intersection point is on the rotation axis of the tool main body and is perpendicular to the imaginary XY axes. Two cutting blades are located on both sides of the Y-axis and extend in the radial direction, one of the cutting blades is raised to the center and extends from the outer peripheral side to at least the X-axis, and the other cutting blade is the outer peripheral Extending from the side to a position that does not reach the X-axis, there is no cutting edge near the rotation axis O at the tip end of the tool body, so that it is possible to prevent the cutting edge in this region from being damaged. Since they do not face each other in the axial direction, a narrow core portion sandwiched between both cutting edges is not formed, and this point can also prevent the cutting edges from being damaged. Moreover, since one of the cutting edges extends at least up to the X-axis, the uncut portion in the region between the two cutting edges can be crushed by the tip of the tool body. The distance n in the Y-axis direction between the ends of the two cutting edges is 0 <n ≦, where D is the outer diameter of the tip of the tool body.
Since it is 0.3D, it is possible to suppress the loss of both cutting edges, and because the vicinity of the center is cut by only one cutting edge, the machining accuracy can be reduced without applying excessive cutting force to one cutting edge. Can be improved.

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

【図１】 本発明の実施の形態によるボールエンドミル
の刃部の側面図である。FIG. 1 is a side view of a blade portion of a ball end mill according to an embodiment of the present invention.

【図２】 図１に示すボールエンドミルの先端面図であ
る。FIG. 2 is a front end view of the ball end mill shown in FIG.

【図３】 実施の形態によるボールエンドミルの回転軸
線付近の加工面の仕上げ面粗さの測定結果を示す図であ
る。FIG. 3 is a diagram showing a measurement result of a finished surface roughness of a processed surface near a rotation axis of the ball end mill according to the embodiment.

【図４】 従来のボールエンドミルによる図４と同様な
図である。FIG. 4 is a view similar to FIG. 4 showing a conventional ball end mill.

【図５】 従来のボールエンドミルの先端面図である。FIG. 5 is a front end view of a conventional ball end mill.

【図６】 他の従来のボールエンドミルの刃部の側面図
である。FIG. 6 is a side view of a blade portion of another conventional ball end mill.

【図７】 図６に示すボールエンドミルの先端面図であ
る。FIG. 7 is a front end view of the ball end mill shown in FIG. 6;

【符号の説明】[Explanation of symbols]

２０ ボールエンドミル ２１ 工具本体 ２４ 主切刃 ２５ 副切刃 ２６ 凹部 Reference Signs List 20 Ball end mill 21 Tool body 24 Main cutting edge 25 Secondary cutting edge 26 Recess

Claims (2)

【特許請求の範囲】[Claims] 【請求項１】 略半球状の先端部を有する工具本体に一
対の切屑排出溝が対向して形成され、これら切屑排出溝
の先端にそれぞれ切刃が設けられたボールエンドミルに
おいて、 前記工具本体の先端面視で、その交点が工具本体の回転
軸線上にあって互いに直交する仮想のＸ−Ｙ軸に対し
て、前記２つの切刃がＹ軸を挟んで両側に位置して径方
向に延びており、一方の前記切刃は芯上がりとされて外
周側から少なくともＸ軸まで延在し、他方の前記切刃は
外周側からＸ軸に至らない位置まで延在していることを
特徴とするボールエンドミル。1. A ball end mill in which a pair of chip discharge grooves are formed to face a tool body having a substantially hemispherical tip, and a cutting edge is provided at a tip of each of the chip discharge grooves. As viewed from the front end, the two cutting edges are located on both sides of the Y-axis and extend in the radial direction with respect to a virtual XY axis whose intersection is on the rotation axis of the tool body and is orthogonal to each other. Wherein one of the cutting blades is raised to the center and extends from the outer peripheral side to at least the X-axis, and the other cutting blade extends from the outer peripheral side to a position not reaching the X-axis. Ball end mill. 【請求項２】 前記２つの切刃の端部間のＹ軸方向の距
離ｎは、工具本体の先端部の外径をＤとして、０＜ｎ≦
０．３Ｄとされていることを特徴とする請求項１記載の
ボールエンドミル。2. The distance n in the Y-axis direction between the ends of the two cutting blades is 0 <n ≦, where D is the outer diameter of the tip of the tool body.
2. The ball end mill according to claim 1, wherein the ball end mill has a diameter of 0.3D.
JP05661097A 1997-03-11 1997-03-11 Ball end mill Expired - Lifetime JP3189725B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP05661097A JP3189725B2 (en) 1997-03-11 1997-03-11 Ball end mill

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP05661097A JP3189725B2 (en) 1997-03-11 1997-03-11 Ball end mill

Publications (2)

Publication Number Publication Date
JPH10249623A true JPH10249623A (en) 1998-09-22
JP3189725B2 JP3189725B2 (en) 2001-07-16

Family

ID=13032025

Family Applications (1)

Application Number Title Priority Date Filing Date
JP05661097A Expired - Lifetime JP3189725B2 (en) 1997-03-11 1997-03-11 Ball end mill

Country Status (1)

Country Link
JP (1) JP3189725B2 (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008302456A (en) * 2007-06-06 2008-12-18 Toyota Motor Corp Ball end mill and its manufacturing method
US7478977B2 (en) * 2005-10-18 2009-01-20 Osg Corporation Ball endmill
WO2009060833A1 (en) 2007-11-07 2009-05-14 Toyota Jidosha Kabushiki Kaisha Ball end mill
US7909545B2 (en) * 2003-12-19 2011-03-22 Hanita Metal Works, Ltd. Ballnose end mill
US20120039677A1 (en) * 2010-08-11 2012-02-16 Kennametal Inc. Contour end mill
CN104400100A (en) * 2014-11-25 2015-03-11 山东大学 Bionics-based end mill with special groove profile and micro blade structure
CN110809501A (en) * 2017-06-30 2020-02-18 佑能工具株式会社 Ball end mill

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7909545B2 (en) * 2003-12-19 2011-03-22 Hanita Metal Works, Ltd. Ballnose end mill
US7478977B2 (en) * 2005-10-18 2009-01-20 Osg Corporation Ball endmill
JP2008302456A (en) * 2007-06-06 2008-12-18 Toyota Motor Corp Ball end mill and its manufacturing method
WO2009060833A1 (en) 2007-11-07 2009-05-14 Toyota Jidosha Kabushiki Kaisha Ball end mill
US8585329B2 (en) 2007-11-07 2013-11-19 Toyota Jidosha Kabushiki Kaisha Ball end mill
US20120039677A1 (en) * 2010-08-11 2012-02-16 Kennametal Inc. Contour end mill
CN104400100A (en) * 2014-11-25 2015-03-11 山东大学 Bionics-based end mill with special groove profile and micro blade structure
CN110809501A (en) * 2017-06-30 2020-02-18 佑能工具株式会社 Ball end mill
KR20200024236A (en) * 2017-06-30 2020-03-06 유니온쓰루 가부시키가이샤 Ball end mill
JPWO2019003965A1 (en) * 2017-06-30 2020-06-11 ユニオンツール株式会社 Ball end mill
EP3646976A4 (en) * 2017-06-30 2021-04-21 Union Tool Co. Ball end mill
CN110809501B (en) * 2017-06-30 2021-08-31 佑能工具株式会社 Ball end mill

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