JPS59175912A - Carbide drill - Google Patents

Abstract

PURPOSE:To improve efficiency by a high speed rotation added with a large thrust by a method wherein the central part and the outer peripheral part of the drill are divided into two layers or more and carbide alloys having properties adapted to the characteristics of respective parts are compounded and integrated. CONSTITUTION:The tough carbide alloy, such as JIS SP40 or the like, for example, is used for the central part 2 of the drill while the super hard carbide alloy, such as JIS SP20 or the like, for example, is used for the outer peripheral part 3 of the drill considering the resistance to the abrasion thereof. The carbide alloy of the central part is formed with a chisel edge 4 and a force cutting edge 5, continuous to the chisel edge 4, while the carbide alloy of the outer peripheral part is formed with the remaining part of the fore cutting edge 5 and a margin part 6. Said materials are connected integrally by metallurgical method respectively.

Description

【発明の詳細な説明】 （イ）　産業上の利用分野 本発明は、鋳鉄或いは鋼材料等の穴あけ加工に用いるド
リル、特に、素材番こ超硬合金を使用した超硬ドリル番
こ関する。DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a drill used for drilling holes in cast iron or steel materials, and particularly to a cemented carbide drill using cemented carbide as the material.

（ロ）　従来技術とその間顕点 一般鋼材や鋳鉄などの穿孔作業には、従来より高速度鋼
製のドリルが使用されて来たが、穿孔作業の高能率化が
強く要求され出した昨今は、ドリルの回転数を高めてそ
の要求に応えるケースが増えており、それ（こ伴なって
、耐摩耗性に優れる超硬合金をドリル材料として使用す
ることか多くなって来た。(b) Conventional technology and highlights High-speed steel drills have traditionally been used for drilling work in general steel materials, cast iron, etc., but recently there has been a strong demand for higher efficiency in drilling work. Increasingly, the number of rotational speeds of drills is increased to meet these demands, and as a result, cemented carbide, which has excellent wear resistance, is increasingly being used as drill material.

しかしながら、超硬合金は、高速度鋼に比べて抗折力に
劣り、切削速度の遅いドリル中心部の切刃か欠損し易く
なることから、その材料は超硬合金の中でも強度の高い
換言すれば耐摩耗性に劣る材料を使わざるを得ず、その
ため、切削速度の速いドリル外周部の摩耗を食い止める
ことは非常に困難であった。However, cemented carbide has inferior transverse rupture strength compared to high-speed steel, and the cutting edge in the center of the drill is likely to break due to slow cutting speeds. For this reason, it is necessary to use materials with poor wear resistance, and as a result, it is extremely difficult to prevent wear on the outer periphery of the drill, where the cutting speed is high.

（ハ）　間頓点を解決するための手段 本発明は、靭性又は耐摩耗性のいずれか一方を眼視すれ
ば、切屑速度が中心部と外面部で異なると云うドリルの
本質的な問題があるが故に他方を犠牲にせざるを得ない
と云う現状技術１こ鑑みてなされたもので、上述の間顆
を使用材料の面から解決したものである。(c) Means for resolving intermittent points The present invention solves the essential problem of drills, which is that the chip velocity differs between the center and the outer surface when looking at either toughness or wear resistance. This was done in view of the current state of the art in which one side has no choice but to sacrifice the other, and it is a solution to the above-mentioned intercondyle from the perspective of the materials used.

即ち、本発明のドリルは切削速度が遅く耐摩耗性よりも
靭性の要求される中心部と、切削速度が速く、耐摩耗性
を眼視すべき外周部を２層もしくはそれ以上の多層に分
け、それぞれの部位の要求特性に合致した性質をもっ超
硬合金を複合的にしかも冶金学的１こ一体化してドリル
を構成する点に特徴を有する。That is, the drill of the present invention has two or more layers divided into a central part where cutting speed is slow and toughness is required rather than wear resistance, and an outer peripheral part where cutting speed is fast and wear resistance should be visually checked. The drill is characterized in that the drill is constructed by combining cemented carbide metals with properties that match the required characteristics of each part and metallurgically integrating them into one.

に）　実施例 第１図及び第２図にその一例を示す。このドリル１は、
全長に渡る中心部２に、例えばＪＩＳ・Ｐ２Ｏ３等の強
靭な超硬合金を、中心部２を包囲する外面部３１こは耐
摩耗性を考慮した例えばＪＩＳ・Ｐ２Ｏ等の高硬度超硬
合金を使用し、上記中心部の超硬合金（こチゼル刃４と
この刃に連続する前切刃５の一部を、一方、外周部の超
硬合金に前切刃５の残りの一部とマージン部６をそれぞ
れ形成しである。2) An example is shown in FIGS. 1 and 2. This drill 1 is
The entire length of the center part 2 is made of a strong cemented carbide such as JIS/P2O3, and the outer surface 31 surrounding the center part 2 is made of a high hardness cemented carbide such as JIS/P2O in consideration of wear resistance. The central part of the cemented carbide (this chisel blade 4 and a part of the front cutting edge 5 continuous to this blade) are used, while the remaining part of the front cutting edge 5 and the margin are made of the cemented carbide of the outer peripheral part. A portion 6 is formed respectively.

上記中心部２の素材と外面部３の素材は、結合力の不足
や、結合後の界面剥離を無くすため、冶金学的方法によ
り一体番こ接合する。その方法としては、例えば特公昭
５７−５７５２号に開示される方法、即ち、第３図に示
すように、中心部を形成する強靭性超硬合金円柱体２ａ
の外周に、筒状の高硬度超硬合金原料粉末成形体又はそ
の予備焼結体３ａを円柱体２ａとの間に空隙を介して同
軸的に配置し、それを再焼結して焼結時の粉末成型体又
はその予備焼結体３ａの収縮１こより両者を一体化し、
その後、必要に応じて再焼結したものを高温高圧気体中
におき、接合界面（こ生じた空洞を消失させる方法等が
挙げられ、これ等の方法【こよって形成したドリル材料
１ａ＋こ、研削、研摩により切屑排出溝７と切刃並びに
マージン部を形成すればよい。The material of the center portion 2 and the material of the outer surface portion 3 are joined together by a metallurgical method in order to eliminate insufficient bonding force and interfacial peeling after bonding. As a method, for example, the method disclosed in Japanese Patent Publication No. 57-5752 is used, that is, as shown in FIG.
A cylindrical high-hardness cemented carbide raw material powder compact or its preliminary sintered body 3a is placed coaxially with the cylindrical body 2a on the outer periphery of the cylindrical body 2a, and the cylindrical body 2a is re-sintered to sinter it. When the powder molded body or its pre-sintered body 3a shrinks, the two are integrated,
Thereafter, if necessary, the re-sintered material may be placed in a high-temperature, high-pressure gas to eliminate the bonding interface (the created cavity). The chip discharge groove 7, the cutting edge, and the margin portion may be formed by polishing.

なお、ドリルを形成する異質の超硬合金は、単に２層重
ねするよりも外層（こ向かって耐摩耗性の順次向上する
材料をより多層１こ積層した方がより効果が上がる。It should be noted that for the different types of cemented carbide that form the drill, it is more effective to laminate the outer layer (on the other hand, one layer of materials with progressively higher wear resistance) than to simply laminate two layers.

（ホ）効果 以上の構成とした本発明のドリルは、通常の穴あけ加工
（こおいて摩耗の激しくなる外周部が耐摩耗性（こ優れ
ているので、全体としての摩耗が減少し、一方、中心部
は強靭であるので中心刃の折損も起こらずかつドリル強
度も充分番こ確保され、従つて、大きなスラスト力を加
えた調速回転（こよる高能率加工を可能にする。(e) The drill of the present invention, which has a structure that is more than effective, has excellent wear resistance on the outer periphery, which is subject to severe wear during normal drilling (during this process), so overall wear is reduced; Since the center is strong, the center blade does not break and the drill strength is sufficient, making it possible to perform high-efficiency machining by controlling the speed of rotation with a large thrust force.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は、本発明のドリルの一実施例を示す側面図、第
２図はその正面図、第３図は溝及び刃付加工を行う前の
ドリル材料を示す斜視図である。 １・・・ドリル、２・・・中心部、３・・・外内部、４
・・・チゼル刃、５・・・前切刃、６・・・マージン部
、７・・・切屑排出溝FIG. 1 is a side view showing an embodiment of the drill of the present invention, FIG. 2 is a front view thereof, and FIG. 3 is a perspective view showing the drill material before being subjected to groove and cutting processing. 1...Drill, 2...Center, 3...Outside and inside, 4
...Chisel blade, 5...Front cutting edge, 6...Margin section, 7...Chip discharge groove

Claims (1)

【特許請求の範囲】[Claims] 強靭性超硬合金円柱体の外周に、一層もしくはそれ以上
の層で外層に向かって順次耐摩耗性の向上する円筒状超
硬合金を同軸的にかつ冶金学的に一体化したものをドリ
ル材とし、それに切削排出溝、切刃並びにマージン部を
施したことを特徴とする超硬ドリル。Drill material is made by coaxially and metallurgically integrating one or more layers of cylindrical cemented carbide whose wear resistance gradually improves toward the outer layer around the outer periphery of a tough cemented carbide cylindrical body. A carbide drill characterized in that it has a cutting discharge groove, a cutting edge, and a margin section.