JP4069673B2

JP4069673B2 - Throw-away cutting tool for internal machining

Info

Publication number: JP4069673B2
Application number: JP2002145214A
Authority: JP
Inventors: 平川崎; 久志遠矢
Original assignee: Kyocera Corp
Current assignee: Kyocera Corp
Priority date: 2002-05-20
Filing date: 2002-05-20
Publication date: 2008-04-02
Anticipated expiration: 2022-05-20
Also published as: JP2003340611A

Description

【０００１】
【発明の属する技術分野】
本発明は、内径加工用スローアウェイ式切削工具に関し、特に、ボーリング（中ぐり）などの内周面加工に適した内径加工用スローアウェイ式切削工具に関する。
【０００２】
【従来の技術】
従来、中ぐり等の内径加工に用いられるボーリングバーは、形状の設計が容易でチップ交換に際しても刃先の取付け精度が高いスローアウェイチップをホルダの先端に取り付けたスローアウェイ式のものが多用されている。
【０００３】
かかるボーリングチップにおいては、小さい内径の穴への中ぐり加工等の要求が高く、この要求に対応するために、例えば、特開平１１−３２０２１７号に記載されるように、チップの周面に小さな径の突出部を形成し、該突出部の先端に切刃を設けたスローアウェイチップが知られている。
【０００４】
【発明が解決しようとする課題】
しかしながら、特開平１１−３２０２１７号のようにチップ本体の周面に突出部を形成したチップでは、穴の中ぐり加工は可能となるものの、切刃の位置精度が悪くなるとともに、切削時にびびり振動が発生しやすくなり、特に小さい内径の穴加工を行う際には切刃の位置が大きくずれて、加工精度が悪くなってしまうおそれがあった。
【０００５】
本発明は、上記課題に対してなされたもので、内径加工の加工精度を向上させることが可能なスローアウェイ式切削工具を提供することにある。
【０００６】
【課題を解決するための手段】
本発明者らは、上記課題に対して検討した結果、チップ本体の複数の周面のうち一対の長い辺を各々含むチップ本体の周面に隣接して設けられる突出部を備えたスローアウェイチップにおいて、チップ本体の複数の周面のうち一対の長い辺を各々含むチップ本体の周面のいずれか一方と他の２つの周面とを含む３つの周面が、ホルダに当接してクランプされるクランプ面であり、かつ、突出部の形成位置をクランプされる周面の延長線よりも内側となるようにするとともに、このクランプされる周面を表面粗さ（Ｒｙ）が０．８μｍ以下の研磨面とすることによって、スローアウェイチップの寸法精度が向上して切刃の位置精度が向上するとともにチップのクランプ力が向上することによってビビリ振動を低減できることを知見し、本発明に至った。
【０００７】
すなわち、本発明の内径加工用スローアウェイ式切削工具は、すくい面をなす上面が、対向する一対の辺が他の辺に比べて長い概略多角形状であるチップ本体と、先端に切刃が形成されるとともに、前記チップ本体の周面から一体的に突出して、かつ、前記チップ本体の複数の周面のうち前記一対の長い辺を各々含むチップ本体の周面に隣接して設けられる突出部と、を備えたスローアウェイチップと、先端に前記スローアウェイチップが取り付けられるチップポケットが設けられたホルダと、を具備してなり、前記チップ本体の複数の周面のうち前記一対の長い辺を各々含むチップ本体の周面のいずれか一方と他の２つの周面とを含む３つの周面が、前記ホルダに当接してクランプされるクランプ面であるとともに、該クランプ面は、表面粗さ（Ｒｙ）が０．８μｍ以下の研磨面であり、前記突出部は、上面視において、前記長い辺の延長線よりも内側に位置させたことを特徴とするものである。
【０００８】
より具体的には、前記チップ本体は、上面視において、概略六角形形状であることを特徴とする。
また、前記チップ本体の複数の周面のうち少なくとも３面以上がクランプ面であることが望ましい。
さらに、前記クランプ面は、前記長い辺を含むチップ本体の周面と、前記チップ本体の複数の周面のうち対向する２つの周面と、を含んでなることが望ましい。
【０００９】
またさらに、上面視において、前記突出部先端に配設される切刃と前記クランプされる周面の延長線との最近接する部分の隙間は０．１〜１ｍｍであることが望ましい。
【００１０】
また、前記切刃の先端はＲ＝０．０３〜０．４ｍｍのコーナーＲを有することが望ましい。
【００１１】
【発明の実施の形態】
本発明の内径加工用スローアウェイ式切削工具の一例について、その概略平面図である図１を基に説明する。
【００１２】
図１の内径加工用スローアウェイ式切削工具１は、ホルダ２の先端に配設したチップポケット３に、概略多角形状のチップ本体５と、チップ本体５の周面から一体的に突出する複数の突出部６、６’を備え、突出部６、６’の先端それぞれに切刃７、７’を設けたスローアウェイチップ（以下、単にチップと略す。）８を取り付けてなる。
【００１３】
チップ８の具体的な形状について説明すると、例えば、チップ本体５の形状は、特にボーリング加工や溝入れ加工等の内径加工を施す部分が被削材の広くフラットな面に内径加工を施すような場合においても容易に内径加工が可能であり、後述する突出部６の長さを長くできるとともに、研磨の容易さの点、クランプ力を高める点で、対向する一対の辺１０ａ、１０ｄが他の辺に比べて長い概略六角形形状であることが望ましく、その寸法は長軸ａが９〜１５ｍｍ、特に１０〜１３ｍｍ、短軸ｂが６〜１０ｍｍ、特に６．５〜９ｍｍであることが望ましい。この対向する一対の長い辺１０ａ、１０ｄに隣接して、特に長い辺１０ａ、１０ｄの延長線方向より５〜４５°内側になる方向に突出部６、６’が形成されている。
【００１４】
また、チップ８を図１のＰ方向から見た正面図である図３に示すように、チップ８の厚みｔ₁は加工に耐えうる強度を持つ上では、２〜５ｍｍ、特に２．５〜４ｍｍであることが望ましい。
【００１５】
さらに、突出部６の形状は、小さな内径の穴に対しても中ぐり加工等の内径加工が容易にできる点で、直径１〜２ｍｍの円柱状、楕円柱、またはコーナーＲを有する一辺が０．５〜１ｍｍの四角柱状で、その突き出し長さＬはチップ本体５の長軸ａに対する比Ｌ／ａが０．２〜０．５、特に０．３〜０．４であることが望ましい。
【００１６】
また、チップ本体５の厚みｔ₁に対する突出部６の厚みｔ₂は、小径の穴加工ができるとともに突出部６の剛性、強度を高めて突出部６のたわみや破損を防止できる点で、厚み比（ｔ₂／ｔ₁）が０．４〜１であることが望ましい。
【００１７】
突出部６の先端に形成される切刃７は、中ぐり加工に適するように突出部６が進行方向に対して前方に配置される形状や、引き加工に適するように突出部６が進行方向に対して後方に配置される形状等適宜調整される。さらに、切刃７には適宜ブレーカを形成することもできる。
【００１８】
本発明によれば、チップ８をチップ本体５の複数の周面１０ａ、１０ｂ、１０ｃにてクランプするとともに、該クランプ面１０ａ、１０ｂ、１０ｃ（および１０ｄ）を表面粗さ（Ｒｙ）が０．８μｍ以下、特に０．５μｍ以下の研磨面としたことが大きな特徴であり、これによって、チップ８の取り付け位置精度が向上することから、切刃７、７の位置精度を著しく向上させることができるとともに、チップ８のクランプ力を高めて切削時のびびり振動を抑制することができる結果、安定した精度の高い内径加工が可能となる）。すなわち、チップ８の位置精度が悪いとクランプ力が低下し、クランプ力が低下するとびびり振動等により切刃位置が狂う可能性がある。なお、ホルダは基本的に交換しないので交換するチップの位置精度がよければ問題はなく、チップポケットの壁面の表面粗さは通常は問題にならない。クランプ面１０ａ〜１０ｄの表面粗さ（Ｒｙ）が０．８μｍを超えるとチップ８の取り付け位置精度が低下して切刃７の位置ずれが生じるとともに、チップ８のクランプ力が極端に低下して、切削時のびびり振動が増大する。
【００１９】
また、本発明によれば、クランプ面１０ａ〜１０ｄの表面粗さ（Ｒｙ）を上記範囲に制御して研磨加工を容易かつ精度の高いものとするために、突出部６がクランプ面１０ａ、１０ｃの延長線ＡおよびＢよりも内側に位置することが重要である。このように構成すると、突出部が研磨加工の際に邪魔にならないので研磨加工が容易かつ精度よくできる。また、かかる構成によれば、チップ８をホルダ２に取り付けた際にチップポケット３内に収納されるほうの突出部６’が収納時の妨げとなることはなく、チップポケット３を単純な形状にできることから、チップポケット３の寸法精度が高く、チップ８の取付け精度を向上できるという効果もある。
【００２０】
なお、研磨加工時に切刃７を誤って加工し切刃７の形状が変化してしまうことを防止する点で、突出部６先端に配設される切刃７’とクランプ面１０ａの延長線との最近接する部分の隙間が０．１〜１ｍｍであることが望ましい。
【００２１】
さらに、本発明によれば、切削面の平滑性を高め、切刃７の強度を高める点で、図２の切刃７部分の要部拡大図に示すように、切刃７がＲ＝０．０３〜０．４ｍｍのコーナーＲを有することが望ましい。Ｒ＜０．０３ｍｍの場合は、切刃強度が低下するとともに、研削面が粗くなりやすい。また、Ｒ＞０．４ｍｍの場合は、切削抵抗が増大して切れ味が悪くなりびびりが発生しやすくなる。
【００２２】
なお、上記チップ８は、例えば超硬合金、サーメット、セラミック、ダイヤモンド、ＣＢＮ等からなり、また、かかる母材の表面の少なくとも切刃７部分にＴｉＣ、ＴｉＣＮ、ＴｉＮ、ＴｉＡｌＮ、Ａｌ₂Ｏ₃の群から選ばれる少なくとも１種の硬質膜を被覆することもできる。
【００２３】
また、図１、３およびチップ８を図１のＱ方向から見た図４に示すように、チップ本体５には厚さ方向に貫通するクランプねじ用の貫通孔１２が配設されており、貫通孔１２およびホルダ２のチップポケット３内に形成されるネジ孔（図示せず）内にクランプネジ１１をネジ止めすることによってチップ８をホルダ２に装着することができる。なお、貫通孔１２のすくい面４側の周縁にはテーパを形成することが望ましい。
【００２４】
なお、チップ８をクランプする形態としては、上記クランプネジ１１によるねじ止め以外にも、シャンクへクランプ駒を装着してクランプオン方式とする方法であってもよく、この場合にはチップ本体５には貫通孔１２に代えて凹状のクランプ駒の受け部（図示せず）を設けるか、またはチップ本体５の主面が平坦面であってもよい。
【００２５】
また、上述したチップ８を保持するホルダ２は、例えば、断面が角形をなす柱状のシャンク１３の先端に図１に示すようなチップポケット３を形成してなり、ホルダ２のシャンク１３を刃物台（図示せず）の所定位置に固定して中ぐり加工等を行う。
【００２６】
【発明の効果】
以上詳述したように、本発明の内径加工用スローアウェイ式切削工具によれば、先端に切刃が形成された突出部をチップ本体の複数の周面のうち一対の長い辺を各々含むチップ本体の周面に隣接して設けたスローアウェイチップにおいて、チップ本体の複数の周面のうち一対の長い辺を各々含むチップ本体の周面のいずれか一方と他の２つの周面とを含む３つの周面が、ホルダに当接してクランプされるクランプ面であり、かつ、突出部の形成位置をクランプ面の延長線よりも内側となるようにするとともに、該クランプ面を表面粗さ（Ｒｙ）が０．８μｍ以下の研磨面とすることによって、スローアウェイチップの寸法精度が向上して切刃位置精度が向上するとともにチップのクランプ力が向上することによってビビリ振動の低減できる。
【図面の簡単な説明】
【図１】本発明の内径加工用スローアウェイ式切削工具の概略平面図である。
【図２】図１の内径加工用スローアウェイ式切削工具のスローアウェイチップの切刃部分の要部拡大図である。
【図３】図１の内径加工用スローアウェイ式切削工具のスローアウェイチップを矢印Ｐ方向から見た図である。
【図４】図１の内径加工用スローアウェイ式切削工具のスローアウェイチップを矢印Ｑ方向から見た図である。
【符号の説明】
１内径加工用スローアウェイ式切削工具
２ホルダ
３チップポケット
５チップ本体
６突出部
７切刃
８スローアウェイチップ
１０（１０ａ、１０ｂ、１０ｃ）クランプ面
１１クランプネジ
１２貫通孔
１３シャンク[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a throw-away cutting tool for inner diameter machining, and more particularly to a throw-away cutting tool for inner diameter machining suitable for inner peripheral surface machining such as boring (boring).
[0002]
[Prior art]
Conventionally, boring bars used for boring and other inner diameter machining are often throw-away types with a throw-away tip attached to the tip of the holder that is easy to design in shape and has a high blade tip mounting accuracy when changing the tip. Yes.
[0003]
In such a boring tip, there is a high demand for boring or the like to a hole with a small inner diameter. In order to meet this demand, for example, as described in JP-A-11-320217, a small peripheral surface of the tip is used. 2. Description of the Related Art A throw-away tip is known in which a protruding portion having a diameter is formed and a cutting edge is provided at the tip of the protruding portion.
[0004]
[Problems to be solved by the invention]
However, in a chip in which a projecting portion is formed on the peripheral surface of the chip body as in JP-A-11-320217, boring of the hole is possible, but the position accuracy of the cutting edge is deteriorated and chatter vibration occurs during cutting. In particular, when drilling a hole with a small inner diameter, the position of the cutting edge may be greatly displaced, and the processing accuracy may be deteriorated.
[0005]
The present invention has been made with respect to the above-described problems, and it is an object of the present invention to provide a throw-away type cutting tool capable of improving the machining accuracy of the inner diameter machining.
[0006]
[Means for Solving the Problems]
As a result of studying the above problems, the present inventors have found that a throw-away tip provided with a protruding portion provided adjacent to the peripheral surface of the chip body that includes each of a pair of long sides among the plurality of peripheral surfaces of the chip body 3, three peripheral surfaces including one of the peripheral surfaces of the chip main body each including a pair of long sides and the other two peripheral surfaces of the plurality of peripheral surfaces of the chip main body are clamped in contact with the holder. The projecting portion is formed on the inner side of the extended line of the peripheral surface to be clamped, and the surface roughness (Ry) of the peripheral surface to be clamped is 0.8 μm or less. By using the polished surface, it was found that chatter vibration can be reduced by improving the dimensional accuracy of the throw-away tip and improving the positional accuracy of the cutting edge and improving the clamping force of the tip. Was Tsu.
[0007]
In other words, the throw-away cutting tool for inner diameter machining of the present invention has a chip body in which the upper surface forming the rake face is a substantially polygonal shape in which a pair of opposite sides are longer than the other sides, and a cutting edge is formed at the tip. And a protrusion provided integrally adjacent to the peripheral surface of the chip body that protrudes integrally from the peripheral surface of the chip body and includes each of the pair of long sides among the plurality of peripheral surfaces of the chip body And a holder provided with a tip pocket to which the throw-away tip is attached at the tip thereof, and the pair of long sides of the plurality of peripheral surfaces of the tip body. three periphery including the one and the other two of the peripheral surface of the peripheral surface of the chip body, each comprising, together with a clamping surface to be clamped in contact with the holder, the clamp surface, the surface A is (Ry) the following polishing surface 0.8 [mu] m, the protrusion, in top view, is characterized in that is positioned inside the extension line of the long sides.
[0008]
More specifically, the tip body in a top view, and wherein the schematic hexagonal der Rukoto.
Moreover, it is desirable that at least three or more of the plurality of peripheral surfaces of the chip body are clamp surfaces.
Furthermore, it is preferable that the clamp surface includes a peripheral surface of the chip body including the long side and two peripheral surfaces facing each other among the plurality of peripheral surfaces of the chip body.
[0009]
Furthermore, in a top view, it is desirable that a clearance between a cutting edge disposed at the tip of the projecting portion and an extension line of the clamped peripheral surface is 0.1 to 1 mm.
[0010]
The tip of the cutting blade preferably has a corner R of R = 0.03 to 0.4 mm.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
An example of the throw-away cutting tool for inner diameter machining of the present invention will be described based on FIG. 1 which is a schematic plan view thereof.
[0012]
The throw-away cutting tool 1 for inner diameter machining in FIG. 1 has a plurality of chip bodies 3 that are substantially polygonal and project from a peripheral surface of the chip body 5 into a chip pocket 3 disposed at the tip of a holder 2. A throw-away tip (hereinafter simply abbreviated as a tip) 8 provided with projections 6 and 6 ′ and provided with cutting edges 7 and 7 ′ at the ends of the projections 6 and 6 ′ is attached.
[0013]
The specific shape of the tip 8 will be described. For example, the shape of the tip body 5 is such that the portion subjected to inner diameter processing such as boring processing or grooving performs inner diameter processing on a wide flat surface of the work material. Even in the case, the inner diameter can be easily processed, and the length of the protruding portion 6 described later can be increased, and the pair of opposing sides 10a and 10d is different in terms of ease of polishing and increasing clamping force. It is desirable to have a substantially hexagonal shape that is longer than the side, and the dimensions are preferably 9 to 15 mm for the major axis a, particularly 10 to 13 mm, and 6 to 10 mm for the minor axis b, particularly 6.5 to 9 mm. . Adjacent to the pair of long sides 10a and 10d that face each other, protrusions 6 and 6 ′ are formed in a direction that is 5 to 45 ° inward from the extension line direction of the long sides 10a and 10d.
[0014]
Further, as shown in FIG. 3 which is a front view of the chip 8 as viewed from the direction P in FIG. 1, the thickness t _{1 of the} chip 8 is 2 to 5 mm, particularly 2.5 to 5 in order to have the strength to withstand the processing. 4 mm is desirable.
[0015]
Further, the shape of the protrusion 6 is such that a bore having a small inner diameter can be easily bored, such as boring, so that one side having a cylindrical shape having a diameter of 1 to 2 mm, an elliptical column, or a corner R is 0. It is desirable that the ratio L / a to the major axis a of the chip body 5 is 0.2 to 0.5, particularly 0.3 to 0.4.
[0016]
Further, the thickness t ₂ of the protruding portion 6 with respect to the thickness t ₁ of the chip body 5 is such that a small-diameter hole can be drilled and the rigidity and strength of the protruding portion 6 can be increased to prevent deflection and breakage of the protruding portion 6. The ratio (t ₂ / t ₁ ) is preferably 0.4-1.
[0017]
The cutting edge 7 formed at the tip of the projecting portion 6 has a shape in which the projecting portion 6 is arranged forward with respect to the traveling direction so as to be suitable for boring, and the projecting portion 6 has a traveling direction so as to be suitable for drawing processing. For example, the shape of the rearward arrangement is appropriately adjusted. Further, a breaker can be appropriately formed on the cutting edge 7.
[0018]
According to the present invention, the chip 8 is clamped by the plurality of peripheral surfaces 10a, 10b, 10c of the chip body 5, and the clamp surfaces 10a, 10b, 10c (and 10d) have a surface roughness (Ry) of 0. A great feature is that the polished surface is 8 μm or less, particularly 0.5 μm or less, and this improves the mounting position accuracy of the chip 8, and thus the position accuracy of the cutting blades 7 and 7 can be remarkably improved. At the same time, the clamping force of the tip 8 can be increased to suppress chatter vibration during cutting, so that stable and highly accurate inner diameter machining is possible. That is, when the position accuracy of the tip 8 is poor, the clamping force is reduced, and when the clamping force is reduced, the cutting edge position may be distorted due to chatter vibration or the like. Since the holder is not basically replaced, there is no problem if the position accuracy of the replaced chip is good, and the surface roughness of the wall surface of the chip pocket is not usually a problem. If the surface roughness (Ry) of the clamping surfaces 10a to 10d exceeds 0.8 μm, the mounting position accuracy of the tip 8 is lowered, the position of the cutting edge 7 is displaced, and the clamping force of the tip 8 is extremely lowered. Chatter vibration during cutting increases.
[0019]
Further, according to the present invention, in order to control the surface roughness (Ry) of the clamp surfaces 10a to 10d within the above range and make the polishing process easy and accurate, the protrusion 6 has the clamp surfaces 10a and 10c. It is important to be located inside the extension lines A and B. If comprised in this way, since a protrusion part does not become obstructive in the case of grinding | polishing processing, grinding | polishing processing can be performed easily and accurately. Further, according to this configuration, when the chip 8 is attached to the holder 2, the protruding portion 6 ′ stored in the chip pocket 3 does not hinder the storage, and the chip pocket 3 has a simple shape. Therefore, the dimensional accuracy of the chip pocket 3 is high, and the mounting accuracy of the chip 8 can be improved.
[0020]
Note that the cutting edge 7 ′ disposed at the tip of the protruding portion 6 and an extension line of the clamp surface 10a are prevented in that the cutting edge 7 is mistakenly processed during polishing and the shape of the cutting edge 7 is prevented from changing. It is desirable that the gap between the closest parts to the above is 0.1 to 1 mm.
[0021]
Furthermore, according to the present invention, the cutting edge 7 has R = 0 as shown in the enlarged view of the main part of the cutting edge 7 in FIG. 2 in that the smoothness of the cutting surface is improved and the strength of the cutting edge 7 is increased. It is desirable to have a corner R of 0.03 to 0.4 mm. In the case of R <0.03 mm, the cutting edge strength decreases and the ground surface tends to become rough. In the case of R> 0.4 mm, the cutting resistance increases, the sharpness becomes worse, and chatter is likely to occur.
[0022]
The tip 8 is made of, for example, cemented carbide, cermet, ceramic, diamond, CBN, or the like, and at least the cutting edge 7 portion of the surface of the base material is made of TiC, TiCN, TiN, TiAlN, Al ₂ O ₃ . It is also possible to coat at least one hard film selected from the group.
[0023]
As shown in FIGS. 1 and 3 and FIG. 4 when the chip 8 is viewed from the Q direction of FIG. 1, the chip body 5 is provided with a through hole 12 for a clamp screw that penetrates in the thickness direction. The chip 8 can be mounted on the holder 2 by screwing the clamp screw 11 into a screw hole (not shown) formed in the through-hole 12 and the chip pocket 3 of the holder 2. In addition, it is desirable to form a taper in the periphery of the through hole 12 on the rake face 4 side.
[0024]
The chip 8 may be clamped by using a clamp-on method by attaching a clamp piece to the shank as well as screwing with the clamp screw 11. May be provided with a receiving portion (not shown) of a concave clamp piece in place of the through hole 12, or the main surface of the chip body 5 may be a flat surface.
[0025]
Further, the holder 2 for holding the chip 8 described above is formed, for example, by forming a chip pocket 3 as shown in FIG. 1 at the tip of a columnar shank 13 having a square cross section, and the shank 13 of the holder 2 is attached to the tool post. Fixing at a predetermined position (not shown) performs boring or the like.
[0026]
【The invention's effect】
As described above in detail, according to the throw-away cutting tool for inner diameter processing of the present invention, the tip including the protruding portion having the cutting edge formed at the tip includes a pair of long sides among the plurality of peripheral surfaces of the tip body. The throw-away tip provided adjacent to the peripheral surface of the main body includes one of the peripheral surfaces of the chip main body each including a pair of long sides among the plurality of peripheral surfaces of the chip main body and the other two peripheral surfaces. The three peripheral surfaces are clamp surfaces that are clamped in contact with the holder, and the projecting portions are formed on the inner side of the extension line of the clamp surface. By making the polishing surface Ry) 0.8 μm or less, the dimensional accuracy of the throw-away tip is improved, the cutting edge position accuracy is improved, and the tip clamping force is improved, thereby reducing chatter vibration.
[Brief description of the drawings]
FIG. 1 is a schematic plan view of a throw-away type cutting tool for inner diameter machining of the present invention.
2 is an enlarged view of a main part of a cutting edge portion of a throw-away tip of the throw-away cutting tool for inner diameter machining in FIG. 1. FIG.
3 is a view of a throw-away tip of the throw-away type cutting tool for inner diameter processing of FIG. 1 as viewed from the direction of an arrow P. FIG.
4 is a view of the throw-away tip of the throw-away type cutting tool for inner diameter machining in FIG. 1 as viewed from the direction of arrow Q. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Throw away type cutting tool for internal diameter processing 2 Holder 3 Tip pocket 5 Tip main body 6 Protruding part 7 Cutting edge 8 Throw away tip 10 (10a, 10b, 10c) Clamp surface 11 Clamp screw 12 Through-hole 13 Shank

Claims

The upper surface forming the rake face has a chip body having a substantially polygonal shape in which a pair of opposite sides are longer than the other sides, and a cutting edge is formed at the tip, and protrudes integrally from the peripheral surface of the chip body. And a protruding portion provided adjacent to the peripheral surface of the chip body including each of the pair of long sides among the plurality of peripheral surfaces of the chip body,
A holder provided with a tip pocket to which the throw-away tip is attached at the tip,
Three peripheral surfaces including one of the peripheral surfaces of the chip main body each including the pair of long sides and the other two peripheral surfaces among the plurality of peripheral surfaces of the chip main body are in contact with the holder and clamped As well as the clamping surface
The clamp surface is a polished surface having a surface roughness (Ry) of 0.8 μm or less,
The protrusion is a throw-away cutting tool for inner diameter processing that is located on an inner side of an extension line of the long side in a top view.

The throw-away cutting tool for inner diameter machining according to claim 1, wherein the tip body has a substantially hexagonal shape when viewed from above.

The clamping surface, wherein the circumferential surface of the chip body including a long side, according to claim 1 or 2, characterized in that it comprises a two circumferential surfaces facing of the plurality of the peripheral surface of the chip body Throw-away type cutting tool for inner diameter machining.

In a top view, according to claim 1 to 3 gaps recent contact portion between the extension line of the peripheral surface which is the clamp and cutting blade which is disposed the projecting tip is characterized in that it is a 0.1~1mm The throw-away cutting tool for inner diameter processing according to any one of the above.

The throwaway cutting tool for inner diameter machining according to any one of claims 1 to 4 , wherein the tip of the cutting edge has a corner R of R = 0.03 to 0.4 mm.