JP2002018623A - Cutting tool with level difference - Google Patents
Cutting tool with level differenceInfo
- Publication number
- JP2002018623A JP2002018623A JP2000207481A JP2000207481A JP2002018623A JP 2002018623 A JP2002018623 A JP 2002018623A JP 2000207481 A JP2000207481 A JP 2000207481A JP 2000207481 A JP2000207481 A JP 2000207481A JP 2002018623 A JP2002018623 A JP 2002018623A
- Authority
- JP
- Japan
- Prior art keywords
- drill
- shank
- hole
- small
- cutting edge
- 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.)
- Pending
Links
- 238000005520 cutting process Methods 0.000 title claims abstract description 45
- 230000002093 peripheral effect Effects 0.000 claims abstract description 4
- 239000002131 composite material Substances 0.000 abstract description 6
- 239000000463 material Substances 0.000 description 16
- 238000005553 drilling Methods 0.000 description 9
- 238000004519 manufacturing process Methods 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 238000012545 processing Methods 0.000 description 4
- 229910000831 Steel Inorganic materials 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 238000003754 machining Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 239000010959 steel Substances 0.000 description 3
- 229910000838 Al alloy Inorganic materials 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- PCTMTFRHKVHKIS-BMFZQQSSSA-N (1s,3r,4e,6e,8e,10e,12e,14e,16e,18s,19r,20r,21s,25r,27r,30r,31r,33s,35r,37s,38r)-3-[(2r,3s,4s,5s,6r)-4-amino-3,5-dihydroxy-6-methyloxan-2-yl]oxy-19,25,27,30,31,33,35,37-octahydroxy-18,20,21-trimethyl-23-oxo-22,39-dioxabicyclo[33.3.1]nonatriaconta-4,6,8,10 Chemical compound C1C=C2C[C@@H](OS(O)(=O)=O)CC[C@]2(C)[C@@H]2[C@@H]1[C@@H]1CC[C@H]([C@H](C)CCCC(C)C)[C@@]1(C)CC2.O[C@H]1[C@@H](N)[C@H](O)[C@@H](C)O[C@H]1O[C@H]1/C=C/C=C/C=C/C=C/C=C/C=C/C=C/[C@H](C)[C@@H](O)[C@@H](C)[C@H](C)OC(=O)C[C@H](O)C[C@H](O)CC[C@@H](O)[C@H](O)C[C@H](O)C[C@](O)(C[C@H](O)[C@H]2C(O)=O)O[C@H]2C1 PCTMTFRHKVHKIS-BMFZQQSSSA-N 0.000 description 1
- 229920001342 Bakelite® Polymers 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 239000004637 bakelite Substances 0.000 description 1
- 239000011195 cermet Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000005304 joining Methods 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
Landscapes
- Drilling Tools (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、特に刃先部とシャ
ンク部とが別部材からなるコンポジットタイプで、例え
ばプリント基板に小径の孔部を穿設するのに用いられる
小型ドリル等の切削工具に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting tool such as a small drill used for drilling a small hole in a printed circuit board. .
【０００２】[0002]
【従来の技術】一般に小型ドリルは、穿孔すべき穴がき
わめて小径であり、ドリル本体の先端に例えば直径０．
１〜３．１７５ｍｍ程度の小径棒状のドリル部が設けら
れ、後端側にドリル本体を工作機械の回転軸に把持する
ための比較的大径のシャンク部が設けられている。ドリ
ル部の材質は、通常、硬質の超硬合金が採用されてい
る。そのため、小型ドリルを製造する場合、ドリル部と
シャンク部が一体とされるソリッドタイプでは、例えば
超硬合金の円柱状素材を削り出してドリル部とシャンク
部を一体成形することになり、超硬合金素材が高価であ
ることとドリル部成形のための加工量が大きいために、
高コストになる欠点がある。2. Description of the Related Art Generally, a small drill has an extremely small hole to be drilled.
A small-diameter rod-shaped drill portion of about 1 to 3.175 mm is provided, and a relatively large-diameter shank portion for gripping a drill body on a rotating shaft of a machine tool is provided at a rear end side. Usually, a hard cemented carbide is used as the material of the drill portion. Therefore, when manufacturing a small drill, in the case of a solid type in which the drill portion and the shank portion are integrated, for example, a cylindrical material of cemented carbide is cut out and the drill portion and the shank portion are integrally formed. Because the alloy material is expensive and the amount of processing for forming the drill part is large,
There is a disadvantage of high cost.
【０００３】これに対して、例えば図５に示すようにコ
ンポジットドリル１として、小径のドリル部２を略円柱
状の超硬合金素材で成形し、大径のシャンク部３をスチ
ールやＳＵＳ等、ドリル部と異なる低廉な素材で成形し
て、シャンク部３の先端面３ａに穿孔された孔部４内に
ドリル部２の軸状をなす後部２ａを嵌合するようにした
小型ドリルが提案されている。この場合ドリル部２の後
部２ａをシャンク部３の孔部４に圧入することで一体化
する。このようなコンポジットドリル１では、シャンク
部３とドリル部２の接合部についてシャンク部３とドリ
ル部２のそれぞれに互いに連続する同一のテーパ面を形
成するように全体に滑らかなテーパ状に研削して、シャ
ンク部３からドリル部２に至る側面視直線状のテーパ面
５を形成する。これと共に、テーパ面５に続くドリル部
２の先端を研削加工して小径の刃部２ｂを形成すること
になる。或いは特開平１１−１０４２２号公報記載のよ
うに、コンポジットドリルの接合部においてシャンク部
に平面状の先端面に至るテーパ面を形成すると共に先端
面にその外径より小径の孔部を穿孔してドリル部を嵌合
することで接合部に段差を形成したものもある。On the other hand, as shown in FIG. 5, for example, as a composite drill 1, a small-diameter drill portion 2 is formed from a substantially cylindrical cemented carbide material, and a large-diameter shank portion 3 is made of steel, SUS or the like. A small drill has been proposed which is formed of a low-priced material different from the drill portion so that the shaft-shaped rear portion 2a of the drill portion 2 is fitted into a hole 4 formed in the tip end surface 3a of the shank portion 3. ing. In this case, the rear portion 2a of the drill portion 2 is integrated by press-fitting the hole portion 4 of the shank portion 3. In such a composite drill 1, the joint portion between the shank portion 3 and the drill portion 2 is entirely ground into a smooth taper so that the shank portion 3 and the drill portion 2 form the same continuous tapered surface. Thus, a tapered surface 5 that is linear from the side of the shank 3 to the drill 2 in a side view is formed. At the same time, the tip of the drill portion 2 following the tapered surface 5 is ground to form the small-diameter blade portion 2b. Alternatively, as described in Japanese Patent Application Laid-Open No. H11-10422, a tapered surface is formed at a joint portion of a composite drill at a shank portion to a flat tip surface, and a hole having a diameter smaller than the outer diameter is formed at the tip surface. In some cases, a step is formed at the joint by fitting a drill.
【０００４】[0004]
【発明が解決しようとする課題】しかしながら、テーパ
面５の接合部を有するコンポジットドリル１では、通常
シャンク部３のテーパ面５ａ先端部の肉厚が断面略三角
形状（通常、傾斜角１５°）の肉薄になるためにその先
端部でのドリル部把持力が極端に弱くなる。そのため回
転数６０〜１６０ｍ-1（ｒｐｍ）、送り０．０１〜０．
０３ｍｍ／ｒｅｖ程度の一般的な条件下で穴明け加工す
る場合には特に問題は生じないが、生産性を上げるため
にそれ以上の高い送り速度で穴明け加工を行おうとする
とドリル部にぶれが生じて加工穴位置の精度不良が発生
したりテーパ面の付け根に応力集中が起きてドリル部２
の付け根が折損する等の不具合を生じてしまう。また接
合部に段差を設けたコンポジットドリルでは、シャンク
部の先端面でのドリル部把持力は高くなるが、段差部に
切屑詰まりを生じて切削抵抗の増大による切刃の欠損や
過熱及び摩耗、ひいてはドリル部の折損等を生じるおそ
れがある。However, in the composite drill 1 having the joining portion of the tapered surface 5, the thickness of the tip of the tapered surface 5a of the shank portion 3 is generally triangular in section (usually, the inclination angle is 15 °). As a result, the gripping force of the drill portion at the tip becomes extremely weak. Therefore, the rotation speed is 60 to 160 m -1 (rpm), and the feed is 0.01 to 0.
There is no particular problem when drilling under general conditions of about 03 mm / rev. However, if drilling is performed at a higher feed rate to increase productivity, the drill will run out. As a result, the accuracy of the drilled hole position becomes poor, or stress concentration occurs at the base of the tapered surface, and the drill 2
Troubles such as breakage of the base of the cable. In the case of a composite drill with a step at the joint, the gripping force of the drill part at the tip end surface of the shank is high, but chips are clogged at the step and the cutting edge is lost due to increased cutting resistance, overheating and wear, As a result, there is a possibility that the drill may be broken.
【０００５】本発明は、このような実情に鑑みて、シャ
ンク部と刃先部との接合部に段差部を設けつつも切屑詰
まりを抑制して工具寿命を向上できるようにした段差部
を有する切削工具を提供することを目的とする。[0005] In view of such circumstances, the present invention provides a stepped portion having a stepped portion at the joint between a shank portion and a cutting edge portion, which can suppress chip clogging and improve tool life while providing a stepped portion. The purpose is to provide tools.
【０００６】[0006]
【課題を解決するための手段】本発明に係る段差部を有
する切削工具は、刃先部をシャンク部の孔部に嵌合して
なる切削工具において、刃先部を嵌合するシャンク部の
先端面は刃先部の外径より径が大きく段差部を形成し、
シャンク部の外周面から前記先端面に向けてテーパ面が
形成されており、段差部における刃先部外径とシャンク
部先端面の寸法差ｅが０．０５〜０．５ｍｍの範囲内に
設定されていることを特徴とする。寸法差ｅが上記の範
囲であれば、シャンク部のテーパ面からつづく先端面の
肉厚が確保されて刃先部の把持力が高く高速で切削加工
しても加工精度不良や刃先部の折損等を起こすことがな
く精度良く加工でき、しかも刃先部で生成された切屑が
基端側に走行して段差部に衝突しても切屑詰まりを起こ
すことなく処理して排出でき切削抵抗の増大による切刃
欠損等を生じないので寿命が延びる。尚、シャンク部の
中心軸線に対するテーパ面の傾斜角θが１０〜４５°の
範囲に設定されていることが好ましい。According to the present invention, there is provided a cutting tool having a stepped portion, wherein a cutting edge portion is fitted into a hole of a shank portion. Is larger in diameter than the outer diameter of the blade edge to form a step,
A tapered surface is formed from the outer peripheral surface of the shank portion to the distal end surface, and a dimensional difference e between the cutting edge outer diameter and the shank distal end surface at the step portion is set within a range of 0.05 to 0.5 mm. It is characterized by having. When the dimensional difference e is within the above range, the thickness of the tip surface following the tapered surface of the shank portion is secured, the gripping force of the cutting edge portion is high, and even if cutting is performed at high speed, machining accuracy is poor, and the cutting edge portion is broken. Processing can be performed with high precision without causing cutting, and even if chips generated at the cutting edge run toward the base end and collide with the step, they can be processed and discharged without causing chip clogging, and cutting due to increased cutting resistance Since the blade is not broken, the life is extended. Note that the inclination angle θ of the tapered surface with respect to the center axis of the shank portion is preferably set in a range of 10 to 45 °.
【０００７】本発明による切削工具によれば、シャンク
部を加熱することなく常温下で刃先部を圧入すること
で、シャンク部の硬さが鈍ることがなく確実に嵌合固定
することができる。或いはシャンク部の孔部の内径より
刃先部の外径の方を若干大径に形成して両者の寸法差を
締め代とし、焼き嵌めや冷やし嵌め等の締まり嵌めによ
って嵌合するようにしてもよい。尚、刃先部とシャンク
部は異なる材質で、好ましくは刃先部の方がシャンク部
より高硬度材料からなっている。また刃先部よりシャン
ク部の方が熱膨張係数が大きい材質としてもよい。According to the cutting tool of the present invention, by press-fitting the cutting edge portion at room temperature without heating the shank portion, the hardness of the shank portion can be securely fixed without being dulled. Alternatively, the outer diameter of the cutting edge portion may be slightly larger than the inner diameter of the hole portion of the shank portion, and the dimensional difference between the two may be used as an interference, and fitting may be performed by interference fitting such as shrink fitting or cold fitting. Good. The cutting edge and the shank are made of different materials, and preferably, the cutting edge is made of a harder material than the shank. The shank portion may be made of a material having a larger coefficient of thermal expansion than the cutting edge portion.
【０００８】[0008]
【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小型
ドリルの側面図、図２（Ａ）〜（Ｃ）は図１に示す小型
ドリルの製造過程を示す図である。図１に示す小型ドリ
ル１０は、比較的大径（外径は例えば３〜６ｍｍ）で略
円柱状の例えばＳＵＳやスチールからなるシャンク部１
１と、比較的小径（外径は例えば０．１〜３．１７５ｍ
ｍ）で略棒状とされ例えば超硬合金素材からなる刃先部
としてのドリル部１２とを有している。シャンク部１１
は、その先端部に円錐台周面形状に漸次縮径されたテー
パ部１３が形成され、テーパ部１３の先端面は円形平面
状の肩部１４とされている。肩部１４はその直径がドリ
ル部１２の外径より大きく、肩部１４と同軸の孔部１６
が肩部１４からシャンク部１１内に向けて同軸状に穿孔
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 the small drill according to the embodiment, and FIGS. 2A to 2C are diagrams showing a manufacturing process of the small drill shown in FIG. A small drill 10 shown in FIG. 1 has a relatively large diameter (for example, an outer diameter of 3 to 6 mm) and a substantially cylindrical shank portion 1 made of, for example, SUS or steel.
1 and a relatively small diameter (the outer diameter is, for example, 0.1 to 3.175 m
m) is substantially rod-shaped, and has a drill portion 12 as a cutting edge portion made of, for example, a cemented carbide material. Shank part 11
The tapered portion 13 whose diameter is gradually reduced to the shape of a truncated cone is formed at the distal end, and the distal end surface of the tapered portion 13 is a shoulder 14 having a circular flat shape. The shoulder 14 has a hole 16 whose diameter is larger than the outer diameter of the drill portion 12 and is coaxial with the shoulder 14.
Are coaxially drilled from the shoulder portion 14 into the shank portion 11.
【０００９】ドリル部１２は、例えば全体に略円柱棒状
の軸部１２ａをなしていてこの軸部１２ａ後方の嵌合部
１２ｂがシャンク部１１の孔部１６内に圧入されて嵌合
されており、孔部１６から外側に位置する軸部１２ａの
先端側に刃部１２ｃが形成されている。そして、刃部１
２ｃには例えば螺旋状に切り屑排出溝１８が形成され、
切り屑排出溝１８の回転方向を向く壁面と刃部１２ｃの
先端面との交差稜線は切刃１９とされている。そのた
め、シャンク部１１のテーパ部１３とドリル部１２の軸
部１２ａとの間に肩部１４からなる段差部２０が形成さ
れ、更にドリル部１２の段差部２０から所定距離離間し
た先端側部分に刃部１２ｃが形成されている。ここで軸
部１２ａの外径ｄ１よりシャンク部１１の孔部１６の内
径Ｄ１の方が若干小さく設定されており、寸法差（ｄ１
−Ｄ１）が圧入による締め代とされている。The drill portion 12 forms, for example, a substantially cylindrical rod-shaped shaft portion 12a, and a fitting portion 12b behind the shaft portion 12a is press-fitted into the hole 16 of the shank portion 11 and fitted. A blade portion 12c is formed on the tip side of the shaft portion 12a located outside the hole portion 16. And the blade part 1
In 2c, for example, a chip discharge groove 18 is formed in a spiral shape,
The intersection ridgeline between the wall surface of the chip discharge groove 18 facing the rotation direction and the tip surface of the blade portion 12c is a cutting edge 19. For this reason, a step portion 20 composed of the shoulder portion 14 is formed between the tapered portion 13 of the shank portion 11 and the shaft portion 12a of the drill portion 12, and is further formed on the tip side portion separated from the step portion 20 of the drill portion 12 by a predetermined distance. A blade portion 12c is formed. Here, the inner diameter D1 of the hole 16 of the shank portion 11 is set to be slightly smaller than the outer diameter d1 of the shaft portion 12a, and the dimensional difference (d1
-D1) is the interference by press fitting.
【００１０】ここでシャンク部１１の肩部１４の半径Ｒ
１とドリル部１２の軸部１２ａの半径ｒ１（＝ｄ１／
２）との寸法差（Ｒ１−ｒ１）である段差ｅを０．０５
〜０．５ｍｍの範囲に設定する。しかも小型ドリル１０
（シャンク部１１）の中心軸線をＯとして中心軸線Ｏに
対するテーパ部１３の傾斜角θは１０〜４５°の範囲に
設定する。段差ｅが０．０５ｍｍより小さいとテーパ部
１３によるドリル部１２の把持力が小さく高速送り加工
時にドリル部１２がぶれて穴位置精度が低下したり折損
を生じ易く、また０．５ｍｍより大きいと切屑詰まりを
起こしやすくなる。そして傾斜角θが１０°より小さい
とテーパ部１３によるドリル部１２の保持力が全体に亘
って小さく高速送り切削時に穴位置精度不良や折損を生
じ易く、また４５°より大きいとドリル部１２の把持力
は大きくなるが切屑詰まりを起こし易い。Here, the radius R of the shoulder 14 of the shank 11
1 and the radius r1 of the shaft portion 12a of the drill portion 12 (= d1 /
Step e, which is the dimensional difference (R1-r1) from 2), is 0.05
Set within a range of 0.5 mm. Moreover, a small drill 10
Assuming that the central axis of the (shank portion 11) is O, the inclination angle θ of the tapered portion 13 with respect to the central axis O is set in the range of 10 to 45 °. When the level difference e is smaller than 0.05 mm, the gripping force of the drill portion 12 by the tapered portion 13 is small, and the drill portion 12 is shaken at the time of high-speed feeding, and the hole position accuracy is likely to be reduced or broken. Chips are easily clogged. When the inclination angle θ is smaller than 10 °, the holding force of the drill portion 12 by the tapered portion 13 is small throughout, and the hole position accuracy is poor and breakage is likely to occur during high-speed cutting. The gripping force increases, but chips are easily clogged.
【００１１】本実施の形態による小型ドリル１０は上述
のように構成されており、次にこの小型ドリル１０の製
造方法について、図２（Ａ）乃至（Ｃ）により説明す
る。図２（Ａ）及び（Ｂ）において、シャンク部１１は
図１に示すものと同一形状である。シャンク部１１に嵌
合すべきドリル部１２は図１における軸部１２ａと同一
外径の略円柱棒状とされ、嵌合部１２ｂの後端がテーパ
状に面取り加工されて面取り部ｃとされ、面取り部ｃは
最小径がシャンク部１１の孔部１３の内径Ｄ１より小さ
く最大径が軸部１２ａと同一で孔部１３の内径より若干
大きい外径ｄ１とされている。シャンク部１１の孔部１
６の内径Ｄ１は例えばφ１．４ｍｍ程度とされ、面取り
部ｃを除いたドリル部１２（軸部１２ａ）の外径ｄ１よ
り若干小径（例えば１０μｍ程度）に形成されている。
孔部１３の内径Ｄ１とドリル部１２の外径ｄ１との寸法
差は、シャンク部１１やドリル部１２の大きさ寸法によ
って相違するが、例えば０より大きく、１００μｍ程度
以下とする。寸法差が１００μｍより大きいと圧入が困
難となる。寸法差は、好ましくは５０μｍ以下、更に好
ましくは２０μｍ以下とする。The small drill 10 according to the present embodiment is configured as described above. Next, a method for manufacturing the small drill 10 will be described with reference to FIGS. 2A and 2B, the shank portion 11 has the same shape as that shown in FIG. The drill portion 12 to be fitted to the shank portion 11 has a substantially cylindrical rod shape having the same outer diameter as the shaft portion 12a in FIG. 1, and the rear end of the fitting portion 12b is chamfered into a tapered shape to form a chamfered portion c. The chamfered portion c has an outer diameter d1 whose minimum diameter is smaller than the inner diameter D1 of the hole portion 13 of the shank portion 11 and whose maximum diameter is the same as the shaft portion 12a and is slightly larger than the inner diameter of the hole portion 13. Hole 1 of shank 11
6 has an inner diameter D1 of, for example, about φ1.4 mm, and is formed to be slightly smaller (eg, about 10 μm) than the outer diameter d1 of the drill portion 12 (the shaft portion 12a) excluding the chamfered portion c.
The dimensional difference between the inner diameter D1 of the hole portion 13 and the outer diameter d1 of the drill portion 12 differs depending on the size of the shank portion 11 and the drill portion 12, but is, for example, larger than 0 and about 100 μm or less. If the dimensional difference is larger than 100 μm, press fitting becomes difficult. The dimensional difference is preferably 50 μm or less, more preferably 20 μm or less.
【００１２】そして小型ドリル１０の製造に際して、常
温下で油剤等の潤滑剤を用いることなく、ドリル部１２
の嵌合部１２ｂの面取り部ｃをシャンク部１１の肩部１
４の孔部１６に同軸状に押し当てて圧入する。すると、
孔部１６の内壁はドリル部１２の面取り部ｃに押圧され
て全周に亘ってわずかづつ押し広げられつつ、ドリル部
１２の嵌合部１２ｂが孔部１６内に押し込まれてゆく。
そして、シャンク部１１の後端からドリル部１２の先端
までの長さが所定の寸法になるまで押し込まれたことで
小型ドリル１０の全長が設定され、圧入によるドリル部
１２とシャンク部１１の嵌合工程が完了する（図２
（Ｃ）参照）。この状態で、シャンク部１１とドリル部
１２の接合部では、テーパ部１３とドリル部１２との間
に肩部１４による段差部２０が形成されている。次に、
ドリル部１２の肩部１４から所定距離離間した部分から
先端にかけて研削加工して、刃部１２ｃに螺旋状の切屑
排出溝１８と切刃１９を形成する。このようにして図１
に示す小型ドリル１０が製造される。When manufacturing the small drill 10, the drill portion 12 is formed at room temperature without using a lubricant such as an oil agent.
The chamfered portion c of the fitting portion 12b of the shank portion 11
4 is pressed coaxially and pressed into the hole 16. Then
The inner wall of the hole 16 is pressed by the chamfered portion c of the drill portion 12 and is gradually spread over the entire circumference, while the fitting portion 12b of the drill portion 12 is pushed into the hole 16.
Then, the entire length of the small drill 10 is set by being pushed until the length from the rear end of the shank portion 11 to the front end of the drill portion 12 reaches a predetermined dimension, and the fitting of the drill portion 12 and the shank portion 11 by press fitting is performed. The combined process is completed (Fig. 2
(C)). In this state, at the joint portion between the shank portion 11 and the drill portion 12, a step portion 20 is formed between the tapered portion 13 and the drill portion 12 by the shoulder portion 14. next,
Grinding is performed from the portion of the drill portion 12 spaced apart from the shoulder portion 14 by a predetermined distance from the tip to form a spiral chip discharge groove 18 and a cutting edge 19 in the blade portion 12c. Thus, FIG.
Is manufactured.
【００１３】次に本発明の実施例と従来の小型ドリルに
ついて比較試験を行った。表１に示すように、実施例１
〜８として実施の形態における段差ｅと傾斜角θの数値
範囲を有する小型ドリル１０を用い、従来例１，２とし
て図４に示すシャンク部とドリル部に段差のない小型ド
リル１を用い、比較例１〜６として実施の形態とほぼ同
一形状で段差ｅと傾斜角θの少なくともいずれかが上記
数値範囲外のものを用いた。尚、各小型ドリルにおいて
ドリル部の切刃の外径をφ０．３５ｍｍとし、回転速度
を７００００min-1とし、被削材として厚さ１．６ｍｍ
のベークライト板の敷き板と厚さ０．１５ｍｍのアルミ
合金製のあて板との間に配線板を６層積層した厚さ１．
６ｍｍのプリント基板を２枚挟んだものを用いた。そし
て各小型ドリルについて送り速度を次第に大きくして折
損が発生する送り速度を測定した。その結果が表１に示
されている。Next, a comparative test was conducted between the embodiment of the present invention and a conventional small drill. As shown in Table 1, Example 1
The small drill 10 having the numerical range of the step e and the inclination angle θ in the embodiment is used as 8, and the small drill 1 having no step in the shank portion and the drill portion shown in FIG. Examples 1 to 6 each having substantially the same shape as the embodiment and having at least one of the step e and the inclination angle θ out of the above numerical range were used. In each of the small drills, the outer diameter of the cutting edge of the drill portion was φ0.35 mm, the rotation speed was 70000 min −1, and the thickness of the work material was 1.6 mm.
6 layers of wiring boards are laminated between a Bakelite board laying board and a 0.15 mm-thick aluminum alloy patch board.
One having two 6 mm printed circuit boards sandwiched therebetween was used. Then, the feed rate at which breakage occurs was measured while gradually increasing the feed rate for each small drill. The results are shown in Table 1.
【００１４】[0014]
【表１】 [Table 1]
【００１５】表１に示す結果から、実施例１〜８では段
差ｅが０．０５ｍｍ〜０．５０ｍｍの範囲、傾斜角θ１
０°〜４５°の範囲で送り速度０．０３５ｍｍ／rev以
上が得られ、特に段差ｅが０．１５ｍｍ以上で傾斜角θ
が１０°〜４５°の範囲で０．０４０ｍｍ／rev以上の
高い送り速度を達成し得た。これに対して、従来例１，
２では傾斜角θが１５°で０．０３３ｍｍ／rev以下の
送り速度となった。比較例１，２では段差ｅが６で傾斜
角θが５０°、２０°で送り速度０．０３０〜０．０３
４ｍｍ／revとなって、切屑詰まりを発生して折損し
た。比較例４，５では段差ｅが０で送り速度０．０２８
〜０．０３２ｍｍ／revと低くドリル部の把持力不足で
あった。また比較例３，６では段差ｅが０．１５ｍｍで
傾斜角θを５０°と５°としてそれぞれ送り速度０．０
３３ｍｍ／revで折損を生じ、前者では切屑詰まりを生
じ後者ではドリル部の把持力不足を生じた。From the results shown in Table 1, in Examples 1 to 8, the step e is in the range of 0.05 mm to 0.50 mm, and the inclination angle θ1
A feed rate of 0.035 mm / rev or more can be obtained in the range of 0 ° to 45 °, and in particular, when the step e is 0.15 mm or more, the inclination angle θ
Can achieve a high feed rate of 0.040 mm / rev or more in the range of 10 ° to 45 °. On the other hand, Conventional Example 1,
In No. 2, the feed rate was 0.033 mm / rev or less at an inclination angle θ of 15 °. In Comparative Examples 1 and 2, the step e is 6, the inclination angle θ is 50 °, and the feed rate is 0.030 to 0.03 at 20 °.
At 4 mm / rev, chips were clogged and broken. In Comparative Examples 4 and 5, the step e was 0 and the feed rate was 0.028.
It was as low as about 0.032 mm / rev and the gripping force of the drill portion was insufficient. In Comparative Examples 3 and 6, the step e was 0.15 mm, the inclination angles θ were 50 ° and 5 °, and the feed speed was 0.0
Breakage occurred at 33 mm / rev, the former caused chip clogging, and the latter caused insufficient gripping force of the drill portion.
【００１６】上記比較試験から得られる好適な段差ｅと
傾斜角θの範囲を図で示すと図３のようになる。図中、
段差ｅが０．１５〜０．５ｍｍの範囲、傾斜角θが１０
〜４５°の範囲を満たす領域ＡＢＣＤで高速送りによる
穴明け加工を達成できる。更に段差ｅを０．３〜０．５
ｍｍに変化させるにつれて傾斜角θを４５°から１５°
に変化させる範囲と、段差ｅを０．０５〜０．１５ｍｍ
に変化させるにつれて傾斜角θを１５°から１０°に変
化させる範囲とを除いた図中のＡａｂＣｃｄＡの範囲で
特に高速な送りによる穴明け加工を達成できる。FIG. 3 shows a suitable range of the step e and the inclination angle θ obtained from the above-mentioned comparative test. In the figure,
Step e is in the range of 0.15 to 0.5 mm, inclination angle θ is 10
Drilling by high-speed feeding can be achieved in the area ABCD satisfying the range of up to 45 °. Further, the step e is 0.3 to 0.5
mm to 45 ° to 15 °
And the step e is set to 0.05 to 0.15 mm.
In particular, in the range of AabCcdA in the drawing except for the range in which the inclination angle θ is changed from 15 ° to 10 ° as the angle is changed, drilling by high-speed feeding can be achieved.
【００１７】上述のように本実施の形態による小型ドリ
ル１０によれば、従来の小型ドリルと比較して、切削加
工時の小型ドリル１０の強度が高く通常の穴明け条件を
越える高速送りで穴明け加工を連続的に行ってもシャン
ク部１１のテーパ部１３によるドリル部１２の把持力が
高いために穴位置精度が高く折損等を生じない。しかも
加工時に切刃１９で生成されてドリル部１２に沿って基
端側に走行する切屑が段差部２０に衝突してもその位置
に詰まることなく排出処理できる。しかも小型ドリル１
０の製造後にテーパ面の加工が不要となって製造コスト
を低廉にできる。As described above, according to the small drill 10 according to the present embodiment, the strength of the small drill 10 at the time of cutting is higher than that of the conventional small drill, and the hole is formed at a high-speed feed exceeding ordinary drilling conditions. Even if drilling is performed continuously, the drilling portion 12 has a high gripping force by the tapered portion 13 of the shank portion 11, so that the hole position accuracy is high and breakage does not occur. In addition, even if chips generated by the cutting blade 19 and traveling toward the base end along the drill portion 12 at the time of processing collide with the step portion 20, the chip can be discharged without being clogged at that position. And small drill 1
After the manufacture of No. 0, processing of the tapered surface becomes unnecessary, and the manufacturing cost can be reduced.
【００１８】尚、上述の実施の形態では、ドリル部１２
を段差部２０から切刃１９の領域まで同一外径の軸状に
形成したが、これに限定されることなくドリル部１２は
適宜形状を採用できる。例えば図４に示すように段差部
２０（肩部１４）に続いてドリル部１２の先端側にテー
パ状部２２を形成してその先をより小径にして切屑排出
溝１８を有する切刃１９を設けてもよい。またシャンク
部１１とドリル部１２の嵌合方法について常温による圧
入に限定されることなく焼き嵌めや冷やし嵌め等の締ま
り嵌めによって行っても良い。例えば図２（Ｂ）の状態
でシャンク部１１の孔部１６を高周波加熱等の加熱によ
って孔部１６の内径Ｄ１がドリル部１２の外径ｄ１より
大きくなるまで熱膨張させて拡径した状態で孔部１６内
にドリル部１２の嵌合部１２ｂを挿入して冷却する。こ
れによって孔部１６が収縮してドリル部１２の外径ｄ１
と孔部１６の内径Ｄ１の寸法差（ｄ１−Ｄ１）を締め代
としてドリル部１２を固着できる。In the above embodiment, the drill 12
Is formed in a shaft shape having the same outer diameter from the step portion 20 to the region of the cutting edge 19, but the present invention is not limited to this, and the drill portion 12 can adopt an appropriate shape. For example, as shown in FIG. 4, a tapered portion 22 is formed on the tip end side of the drill portion 12 following the step portion 20 (shoulder portion 14), the tip of which is made smaller in diameter, and a cutting blade 19 having a chip discharge groove 18 is formed. It may be provided. Further, the method of fitting the shank portion 11 and the drill portion 12 is not limited to press fitting at room temperature, and may be performed by interference fitting such as shrink fitting or cold fitting. For example, in the state shown in FIG. 2 (B), the hole 16 of the shank portion 11 is thermally expanded by heating such as high frequency heating or the like until the inner diameter D1 of the hole portion 16 becomes larger than the outer diameter d1 of the drill portion 12 and expanded. The fitting part 12b of the drill part 12 is inserted into the hole part 16 and cooled. As a result, the hole 16 contracts and the outer diameter d1 of the drill 12 is reduced.
The drill portion 12 can be fixed using the dimensional difference (d1-D1) between the inner diameter D1 and the inner diameter D1 of the hole 16 as an interference.
【００１９】また、互いに嵌合するシャンク部１１の孔
部１６やドリル部１２の嵌合部１２ｂは円柱状に限定さ
れることなく角柱等でもよい。また、シャンク部１１の
材質はＳＵＳやスチールに限らず、アルミニウム合金等
でもよく、ドリル部１２の材質は超硬合金に限らず、サ
ーメット等、シャンク部１１より硬度の高い他の適宜の
材質（高硬度材料）を採用できる。本発明は、上述した
ドリル部１２の外径ｄ１が０．１〜３．１７５ｍｍ程度
の小型ドリルだけに限らずその他の穴明け工具や小径の
エンドミル等各種の切削工具に適用できる。The hole 16 of the shank portion 11 and the fitting portion 12b of the drill portion 12 to be fitted to each other are not limited to a columnar shape, but may be a prism or the like. The material of the shank portion 11 is not limited to SUS or steel, but may be an aluminum alloy. The material of the drill portion 12 is not limited to a cemented carbide, but may be any other appropriate material having a higher hardness than the shank portion 11 such as a cermet. High hardness material) can be adopted. The present invention can be applied not only to a small drill having an outer diameter d1 of the drill portion 12 of about 0.1 to 3.175 mm, but also to various cutting tools such as other drilling tools and small-diameter end mills.
【００２０】[0020]
【発明の効果】上述のように、本発明に係る段差部を有
する切削工具は、刃先部を嵌合するシャンク部の先端面
が刃先部の外径より径が大きく段差部を形成し、シャン
ク部の外周面から先端面に向けてテーパ面が形成されて
おり、段差部における刃先部外径とシャンク部先端面の
寸法差が０．０５〜０．５ｍｍの範囲内に設定されてい
るから、シャンク部のテーパ面からつづく先端面の肉厚
が確保されて刃先部の把持力が高く高速で切削加工して
も加工精度不良や刃先部の折損等を起こすことがなく精
度良く加工でき、しかも切屑が基端側に走行して段差部
に衝突しても切屑詰まりを起こすことなく処理して排出
でき切削抵抗の増大による切刃欠損等を生じないので寿
命が延びる。As described above, in the cutting tool having a step portion according to the present invention, the shank portion to which the cutting edge portion is fitted has a stepped portion whose diameter is larger than the outer diameter of the cutting edge portion and the shank portion is formed. The tapered surface is formed from the outer peripheral surface of the portion toward the distal end surface, and the dimensional difference between the cutting edge outer diameter and the shank distal end surface at the step portion is set within the range of 0.05 to 0.5 mm. The thickness of the tip surface following the tapered surface of the shank is ensured, and the gripping force of the cutting edge is high, so even when cutting at high speed, machining can be performed with high precision without causing poor machining accuracy or breakage of the cutting edge. In addition, even if the chips run toward the base end and collide with the stepped portion, the chips can be processed and discharged without causing clogging of the chips.
【図１】 本発明の実施の形態による小型ドリルの概略
側面図である。FIG. 1 is a schematic side view of a small drill according to an embodiment of the present invention.
【図２】 図１に示す小型ドリルの製造工程を示すもの
で、（Ａ）はシャンク部の側面図、（Ｂ）はシャンク部
にドリル部を圧入する前の状態を示す図、（Ｃ）はシャ
ンク部にドリル部が圧入された状態を示す図である。2A and 2B show a manufacturing process of the small drill shown in FIG. 1, wherein FIG. 2A is a side view of a shank portion, FIG. 2B is a diagram showing a state before the drill portion is press-fitted into the shank portion, and FIG. FIG. 4 is a view showing a state in which a drill portion is press-fitted into a shank portion.
【図３】 実施の形態において段差と傾斜角の好適な範
囲を示す図である。FIG. 3 is a diagram showing a preferred range of a step and an inclination angle in the embodiment.
【図４】 実施の形態による小型ドリルの変形例を示す
概略側面図である。FIG. 4 is a schematic side view showing a modification of the small drill according to the embodiment.
【図５】 従来の小型ドリルの概略側面図である。FIG. 5 is a schematic side view of a conventional small drill.
１０ 小型ドリル １１ シャンク部 １２ ドリル部 １４ 肩部（先端面） １６ 孔部 ２０ 段差部 DESCRIPTION OF SYMBOLS 10 Small drill 11 Shank part 12 Drill part 14 Shoulder part (tip surface) 16 Hole part 20 Step part
───────────────────────────────────────────────────── フロントページの続き (72)発明者 金子 和弘 茨城県結城郡石下町大字古間木1511番地 三菱マテリアル株式会社筑波製作所内 (72)発明者 辛島 民也 茨城県結城郡石下町大字古間木1511番地 三菱マテリアル株式会社筑波製作所内 (72)発明者 小谷 二郎 茨城県結城郡石下町大字古間木1511番地 三菱マテリアル株式会社筑波製作所内 Ｆターム(参考） 3C037 AA09 DD05 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Kazuhiro Kaneko 1511 Furamagi, Ishishita-cho, Yuki-gun, Ibaraki Prefecture Inside the Tsukuba Works, Mitsubishi Materials Corporation (72) Inventor Tamaya Karashima 1511 Furamaki, Ishishita-cho, Yuki-gun, Ibaraki Prefecture Address Mitsubishi Materials Corporation Tsukuba Works (72) Inventor Jiro Otani 1511 Furamagi, Ishishita-cho, Yuki-gun, Ibaraki Pref. Mitsubishi Materials Corporation Tsukuba Works F-term (reference) 3C037 AA09 DD05
Claims (1)
る切削工具において、前記刃先部を嵌合するシャンク部
の先端面は刃先部の外径より径が大きく段差部を形成
し、前記シャンク部の外周面から前記先端面に向けてテ
ーパ面が形成されており、 前記段差部における刃先部外径とシャンク部先端面の寸
法差が０．０５〜０．５ｍｍの範囲内に設定されている
ことを特徴とする段差部を有する切削工具。1. A cutting tool in which a cutting edge is fitted into a hole of a shank, wherein a tip end surface of the shank into which the cutting edge is fitted has a step portion having a diameter larger than the outer diameter of the cutting edge. A tapered surface is formed from the outer peripheral surface of the shank portion to the distal end surface, and a dimensional difference between the outer diameter of the cutting edge portion and the distal end surface of the shank portion in the step portion is within a range of 0.05 to 0.5 mm. A cutting tool having a step portion, which is set.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000207481A JP2002018623A (en) | 2000-07-07 | 2000-07-07 | Cutting tool with level difference |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000207481A JP2002018623A (en) | 2000-07-07 | 2000-07-07 | Cutting tool with level difference |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2002018623A true JP2002018623A (en) | 2002-01-22 |
Family
ID=18704234
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2000207481A Pending JP2002018623A (en) | 2000-07-07 | 2000-07-07 | Cutting tool with level difference |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2002018623A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007052855A1 (en) * | 2005-10-31 | 2007-05-10 | Inkok Industrial Co., Ltd. | Making method of shank drill and shank drill for board hall processing |
| CN102049553A (en) * | 2010-12-01 | 2011-05-11 | 湖北齐能精密工业有限公司 | Cutter special for interference compact concentric splicing circuit board and manufacturing method thereof |
| US8727680B2 (en) | 2009-06-30 | 2014-05-20 | Ibiden Co., Ltd. | Cutting drill and method for manufacturing printed wiring board |
| US8969732B2 (en) | 2011-09-28 | 2015-03-03 | Ibiden Co., Ltd. | Printed wiring board |
-
2000
- 2000-07-07 JP JP2000207481A patent/JP2002018623A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007052855A1 (en) * | 2005-10-31 | 2007-05-10 | Inkok Industrial Co., Ltd. | Making method of shank drill and shank drill for board hall processing |
| US8727680B2 (en) | 2009-06-30 | 2014-05-20 | Ibiden Co., Ltd. | Cutting drill and method for manufacturing printed wiring board |
| CN102049553A (en) * | 2010-12-01 | 2011-05-11 | 湖北齐能精密工业有限公司 | Cutter special for interference compact concentric splicing circuit board and manufacturing method thereof |
| US8969732B2 (en) | 2011-09-28 | 2015-03-03 | Ibiden Co., Ltd. | Printed wiring board |
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