EP0280835A1 - Hollow drill tool - Google Patents

Hollow drill tool Download PDF

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Publication number
EP0280835A1
EP0280835A1 EP19870810686 EP87810686A EP0280835A1 EP 0280835 A1 EP0280835 A1 EP 0280835A1 EP 19870810686 EP19870810686 EP 19870810686 EP 87810686 A EP87810686 A EP 87810686A EP 0280835 A1 EP0280835 A1 EP 0280835A1
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EP
European Patent Office
Prior art keywords
cutting segments
surface layer
hollow drill
diamond grain
carrier body
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.)
Withdrawn
Application number
EP19870810686
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German (de)
French (fr)
Inventor
Helmut Vollmer
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Hilti AG
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Hilti AG
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Publication date
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Publication of EP0280835A1 publication Critical patent/EP0280835A1/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28D—WORKING STONE OR STONE-LIKE MATERIALS
    • B28D1/00—Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor
    • B28D1/02—Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor by sawing
    • B28D1/04—Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor by sawing with circular or cylindrical saw-blades or saw-discs
    • B28D1/041—Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor by sawing with circular or cylindrical saw-blades or saw-discs with cylinder saws, e.g. trepanning; saw cylinders, e.g. having their cutting rim equipped with abrasive particles
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B10/00—Drill bits
    • E21B10/46—Drill bits characterised by wear resisting parts, e.g. diamond inserts
    • E21B10/48—Drill bits characterised by wear resisting parts, e.g. diamond inserts the bit being of core type

Definitions

  • the invention relates to a hollow drill with a hollow cylindrical carrier body, on the drilling direction side open end of which the end face and the circumferential contour of the carrier body projecting cutting segments containing diamond grain are arranged.
  • a hollow drill with cutting segments containing diamond grain is known from AT-PS 373 196.
  • the cutting segments sit on the end face of a hollow cylindrical support body and have an end face pointing in the direction of drilling and an outer contour curved in a circular arc in the axial projection of the hollow drill and concentrically projecting over the circumferential contour of the support body.
  • the diamond grain which is distributed in an embedding material, is not only inside the cutting segments, but is partly exposed to the end face and the outer contour.
  • the cutting segments with the end face remove material from the material to be machined, for example concrete, natural stone, brick, to create a borehole.
  • the outer contour of the cutting segments slides along the wall of the borehole that is being created, thereby causing the hollow drill bit to be guided laterally.
  • This not only results in axial shortening, but also in radial cutting of the cutting segments from the outer contour.
  • the radial cutting of the cutting segments takes place to such a high degree that after just a few drilling operations, only holes with a greatly reduced diameter are created.
  • the drill holes intended to receive them must therefore only be subject to slight fluctuations in diameter. So the acceptable deviation from the ideal diameter is in the range of tenths of a millimeter. Approximately half of this deviation alone takes up the manufacturing tolerances of the hollow drill, so that there is only a very small margin available for the permissible radial removal of the cutting segments.
  • the invention has for its object to provide a hollow drill with cutting segments containing diamond grain, with which a large number of holes can be made with high diameter accuracy.
  • the object is achieved in that the cutting segments have a surface layer which extends concentrically to the circumferential contour of the carrier body and has a higher diamond grain concentration than the remaining area of the cutting segments.
  • the surface layer with an increased diamond grain concentration extends at least over a part of the outer contour of the cutting segments that projects beyond the peripheral contour of the carrier body. Due to the higher diamond grain concentration, the wear resistance of the surface layer is significantly higher than the wear resistance of the remaining area of the cutting segments. This leads to more extensive radial dimensional accuracy of the cutting segments, so that a large number of drill holes with high diameter accuracy can be produced.
  • Particularly high wear resistance is preferably achieved in that the extent of the surface layer measured in the circumferential direction corresponds to that of the cutting segments.
  • the extent of the surface layer measured in the axial direction of the drill also corresponds to that of the cutting segments according to a further proposal of the invention.
  • the extent of the surface layer measured in the axial direction of the drill exceeds the extent of the cutting segments measured in the axial direction and projecting beyond the end face of the carrier body. This design is particularly suitable for workpieces with high strength to improve the radial dimensional accuracy of the cutting segments.
  • the section of the surface layer set back relative to the end face of the carrier body can be fixed on the circumferential contour of the carrier body or can be supported and held by an extension connected to the remaining area of the cutting segments.
  • the recessed section of the surface layer can ensure high radial dimensional accuracy of the cutting segments up to the complete axial shortening of the part of the cutting segments projecting beyond the end face of the carrier body.
  • the diamond grain concentration in the surface layer preferably corresponds to two to five times the diamond grain concentration in the remaining region of the cutting segments.
  • the surface layer advantageously has a thickness of 0.2 to 1 mm. In addition to sufficient wear resistance of the surface layer, this ensures that the surface layer together with the end face of the cutting segments is gradually removed axially without the surface layer adversely affecting the drilling behavior.
  • the hollow drill designated as a whole by 1, consists of a hollow cylindrical carrier body 2 with a drive shaft 3 molded onto the end facing away from the drilling direction and project radially beyond the circumferential contour of the carrier body 2.
  • the cutting segments 4 have an end face 6 pointing in the drilling direction and a surface layer 7 which extends concentrically to the circumferential contour of the carrier body 2 and which also extends counter to the drilling direction and then to the end face 5 along the circumferential contour of the carrier body 2 with a section 8.
  • the Cutting segments 4 consist of an embedding material, for example cobalt with metallic additives such as copper, tin, zinc, tungsten, in which diamond grain 9 is embedded in a spatially distributed manner.
  • the diamond grain concentration is two to five times the remaining area of the cutting segments 4, as shown in FIG. 2.
  • the thickness of the surface layer 7 is 0.2 to 1 mm.

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  • Engineering & Computer Science (AREA)
  • Mining & Mineral Resources (AREA)
  • Geology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Environmental & Geological Engineering (AREA)
  • Fluid Mechanics (AREA)
  • Physics & Mathematics (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Drilling Tools (AREA)
  • Earth Drilling (AREA)
  • Processing Of Stones Or Stones Resemblance Materials (AREA)

Abstract

The hollow drill tool (1) has a hollow-cylindrical support body (2) and cutting segments (4) which consist of an embedding material and a diamond grain (9) held in the latter. The surface layer (7) of the cutting segments (4) which is remote from the axis of the support body (2) has a higher concentration of diamond grain compared with the remaining area of the cutting segments (4). This guarantees the production of a large number of drill holes of high diametral accuracy. <IMAGE>

Description

Die Erfindung betrifft einen Hohlbohrer mit einem hohl­zylindrischen Trägerkörper, an dessen bohrrichtungsseitigem offenen Ende die Stirnseite und die Umfangskontur des Träger­körpers überragende, Diamantkorn enthaltende Schneidsegmente angeordnet sind.The invention relates to a hollow drill with a hollow cylindrical carrier body, on the drilling direction side open end of which the end face and the circumferential contour of the carrier body projecting cutting segments containing diamond grain are arranged.

Aus der AT-PS 373 196 ist ein Hohlbohrer mit Diamantkorn enthaltenden Schneidsegmenten bekannt. Die Schneidsegmente sitzen auf der Stirnseite eines hohlzylindrischen Träger­körpers und verfügen über eine in Bohrrichtung weisende Stirnfläche sowie über eine in der Axialprojektion des Hohl­bohrers kreisbogenförmig gekrümmte, die Umfangskontur des Trägerkörpers konzentrisch überragende Aussenkontur. Das in einem Einbettungsmaterial verteilt gelagerte Diamantkorn befindet sich nicht nur im Innern der Schneidsegmente, son­dern liegt teilweise zur Stirnfläche und zur Aussenkontur hin frei.A hollow drill with cutting segments containing diamond grain is known from AT-PS 373 196. The cutting segments sit on the end face of a hollow cylindrical support body and have an end face pointing in the direction of drilling and an outer contour curved in a circular arc in the axial projection of the hollow drill and concentrically projecting over the circumferential contour of the support body. The diamond grain, which is distributed in an embedding material, is not only inside the cutting segments, but is partly exposed to the end face and the outer contour.

Im Arbeitseinsatz des Hohlbohrers tragen die Schneidsegmente mit der Stirnfläche zur Schaffung eines Bohrloches kreis­ringförmig Material vom Bearbeitungsgut, zB Beton, Natur­stein, Ziegel, ab. Die Aussenkontur der Schneidsegmente gleitet dabei entlang der Wandung des entstehenden Bohr­loches, wodurch eine seitliche Führung des Hohlbohrers be­wirkt wird. So kommt es im Arbeitseinsatz verschleissbedingt nicht nur zur axialen Verkürzung, sondern auch zum radialen Abbau der Schneidsegmente von der Aussenkontur her. Der radiale Abbau der Schneidsegmente erfolgt dabei in einem so hohen Masse, dass schon nach wenigen Bohrvorgängen nur mehr Bohrlöcher mit stark verkleinertem Durchmesser entstehen.When working with the hollow drill, the cutting segments with the end face remove material from the material to be machined, for example concrete, natural stone, brick, to create a borehole. The outer contour of the cutting segments slides along the wall of the borehole that is being created, thereby causing the hollow drill bit to be guided laterally. As a result of wear and tear, this not only results in axial shortening, but also in radial cutting of the cutting segments from the outer contour. The radial cutting of the cutting segments takes place to such a high degree that after just a few drilling operations, only holes with a greatly reduced diameter are created.

Diese Massabweichung ist unerheblich, wenn die Bohrlöcher beispielsweise nur zum Durchführen von Rohren oder durch Nebeneinanderreihung solcher Bohrlöcher zur Herstellung eines Durchbruches dienen sollen. Dagegen sind Bohrlöcher mit solcherart verkleinertem Durchmesser für die Aufnahme mechanischer Dübel ungeeignet, da die Dübel in die Bohrlöcher nur erschwert oder gar nicht einführbar sind. Es ist aber auch nicht möglich, zur Umgehung dieses Problems Hohlbohrer mit einem im Neuzustand vergrösserten Bohrdurchmesser zu verwenden, da so vorerst übergrosse Bohrlöcher entstehen würden, was wiederum den Verankerungswert der Dübel beein­trächtigt.This dimensional deviation is irrelevant if the boreholes are only to be used, for example, to pass through pipes or, by lining up such boreholes, to produce an opening. In contrast, boreholes with such a reduced diameter are for the recording Mechanical anchors are unsuitable because the anchors are difficult to insert into the drill holes or cannot be inserted at all. However, it is also not possible to use hollow drills with a larger bore diameter when new to circumvent this problem, since this would initially result in oversized drill holes, which in turn would affect the anchorage value of the dowels.

Zur Gewährleistung guter Einführbarkeit und hoher Veranke­rungswerte von Dübeln dürfen die zu deren Aufnahme vorge­sehenen Bohrlöcher demgemäss nur geringen Durchmesser­schwankungen unterliegen. So bewegt sich die akzeptable Abweichung vom idealen Durchmesser im Bereich von Zehntel­millimetern. Circa die Hälfte dieser Abweichung nehmen allein die Herstellungstoleranzen des Hohlbohrers in An­spruch, so dass für den zulässigen radialen Abbau der Schneidsegmente nur noch ein sehr kleiner Spielraum zur Verfügung steht.To ensure good insertability and high anchoring values for dowels, the drill holes intended to receive them must therefore only be subject to slight fluctuations in diameter. So the acceptable deviation from the ideal diameter is in the range of tenths of a millimeter. Approximately half of this deviation alone takes up the manufacturing tolerances of the hollow drill, so that there is only a very small margin available for the permissible radial removal of the cutting segments.

Der Erfindung liegt die Aufgabe zugrunde, einen Hohlbohrer mit Diamantkorn enthaltenden Schneidsegmenten zu schaffen, mit dem sich eine grosse Anzahl Bohrlöcher von hoher Durch­messergenauigkeit herstellen lässt.The invention has for its object to provide a hollow drill with cutting segments containing diamond grain, with which a large number of holes can be made with high diameter accuracy.

Erfindungsgemäss wird die Aufgabe dadurch gelöst, dass die Schneidsegmente eine sich konzentrisch zur Umfangskontur des Trägerkörpers erstreckende Oberflächenschicht mit einer gegen­über dem übrigen Bereich der Schneidsegmente höheren Diamant­korn-Konzentration aufweisen.According to the invention, the object is achieved in that the cutting segments have a surface layer which extends concentrically to the circumferential contour of the carrier body and has a higher diamond grain concentration than the remaining area of the cutting segments.

Die Oberflächenschicht mit erhöhter Diamantkorn-Konzen­tration erstreckt sich zumindest über einen Teil der die Um­fangskontur des Trägerkörpers überragenden Aussenkontur der Schneidsegmente. Die Verschleissfestigkeit der Oberflächen­schicht liegt aufgrund der höheren Diamantkorn- Konzen­tration erheblich über der Verschleissfestigkeit des übrigen Bereiches der Schneidsegmente. Dies führt zu weitgehender radialer Masshaltigkeit der Schneidsegmente, so dass eine grosse Anzahl Bohrlöcher von hoher Durchmessergenauigkeit hergestellt werden kann.The surface layer with an increased diamond grain concentration extends at least over a part of the outer contour of the cutting segments that projects beyond the peripheral contour of the carrier body. Due to the higher diamond grain concentration, the wear resistance of the surface layer is significantly higher than the wear resistance of the remaining area of the cutting segments. This leads to more extensive radial dimensional accuracy of the cutting segments, so that a large number of drill holes with high diameter accuracy can be produced.

Besonders hohe Verschleissfestigkeit wird vorzugsweise er­zielt, indem die in Umfangsrichtung gemessene Erstreckung der Oberflächenschicht derjenigen der Schneidsegmente ent­spricht.Particularly high wear resistance is preferably achieved in that the extent of the surface layer measured in the circumferential direction corresponds to that of the cutting segments.

Zur Erhöhung der Verschleissfestigkeit entspricht ferner die in Achsrichtung des Bohrers gemessene Erstreckung der Ober­flächenschicht, nach einem weiteren Vorschlag der Erfindung, derjenigen der Schneidsegmente.To increase the wear resistance, the extent of the surface layer measured in the axial direction of the drill also corresponds to that of the cutting segments according to a further proposal of the invention.

In Weiterbildung der Erfindung übersteigt die in Achsrich­tung des Bohrers gemessene Erstreckung der Oberflächen­schicht die in Achsrichtung gemessene, die Stirnseite des Trägerkörpers überragende Erstreckung der Schneidsegmente. Insbesondere für Bearbeitungsgut mit hoher Festigkeit eignet sich diese Ausbildung zur Verbesserung der radialen Mass­haltigkeit der Schneidsegmente.In a further development of the invention, the extent of the surface layer measured in the axial direction of the drill exceeds the extent of the cutting segments measured in the axial direction and projecting beyond the end face of the carrier body. This design is particularly suitable for workpieces with high strength to improve the radial dimensional accuracy of the cutting segments.

Der gegenüber der Stirnseite des Trägerkörpers zurückver­setzte Abschnitt der Oberflächenschicht kann auf der Umfangs­kontur des Trägerkörpers festgelegt oder durch einen mit dem übrigen Bereich der Schneidsegmente verbundenen Fortsatz hinterstützt und gehalten sein. Durch einen solchen entgegen der Bohrrichtung sich an die Stirnseite des Trägerkörpers anschliessenden Abschnitt der Oberflächenschicht wird die der seitlichen Führung des Hohlbohrers dienende Oberflächen­schicht insgesamt grossflächiger, woraus sich eine Steue­rungsmöglichkeit bezüglich der erforderlichen Diamantkorn-­Konzentration in der Oberflächenschicht insgesamt ergibt. Vor allem kann durch den zurückversetzten Abschnitt der Oberflächenschicht bis zur vollständigen axialen Verkürzung des die Stirnseite des Trägerkörpers überragenden Teiles der Schneidsegmente hohe radiale Masshaltigkeit der Schneid­segmente gewährleistet werden.The section of the surface layer set back relative to the end face of the carrier body can be fixed on the circumferential contour of the carrier body or can be supported and held by an extension connected to the remaining area of the cutting segments. Such a section of the surface layer, which adjoins the end face of the carrier body against the direction of drilling, makes the surface layer serving for lateral guidance of the hollow drill overall more extensive, which results in a possibility of controlling the required diamond grain concentration in the surface layer as a whole. Above all, the recessed section of the surface layer can ensure high radial dimensional accuracy of the cutting segments up to the complete axial shortening of the part of the cutting segments projecting beyond the end face of the carrier body.

Vorzugsweise entspricht die Diamantkorn-Konzentration in der Oberflächenschicht dem Zwei- bis Fünffachen der Diamantkorn-­Konzentration im übrigen Bereich der Schneidsegmente. Mit höherer Festigkeit des Bearbeitungsgutes wird eine höhere, in der voran angegebenen Bandbreite liegende Diamantkorn-Kon­zentration gewählt.The diamond grain concentration in the surface layer preferably corresponds to two to five times the diamond grain concentration in the remaining region of the cutting segments. The higher the strength of the processed material, the higher the diamond grain concentration in the range specified above is chosen.

Mit Vorteil weist die Oberflächenschicht eine Dicke von 0,2 bis 1 mm auf. Damit wird nebst ausreichender Verschleiss­festigkeit der Oberflächenschicht gewährleistet, dass die Oberflächenschicht zusammen mit der Stirnfläche der Schneid­segmente sukzessive axial mitabgetragen wird, ohne dass die Oberflächenschicht das Bohrverhalten nachteilig beeinflusst.The surface layer advantageously has a thickness of 0.2 to 1 mm. In addition to sufficient wear resistance of the surface layer, this ensures that the surface layer together with the end face of the cutting segments is gradually removed axially without the surface layer adversely affecting the drilling behavior.

Die Erfindung wird nachstehend anhand einer Zeichnung, die ein Ausführungsbeispiel wiedergibt, näher erläutert. Es zeigen:

  • Fig. 1 einen Hohlbohrer in perspektivischer Darstellung;
  • Fig. 2 eine vergrösserte Detail-Ansicht auf die Stirnseite des Hohlbohrers gemäss Fig. 1.
The invention is explained below with reference to a drawing which shows an embodiment. Show it:
  • Figure 1 shows a hollow drill in a perspective view.
  • FIG. 2 shows an enlarged detail view of the end face of the hollow drill according to FIG. 1.

Der insgesamt mit 1 bezeichnete Hohlbohrer besteht aus einem hohlzylindrischen Trägerkörper 2 mit einem an dem der Bohr­richtung abgewandten Ende angeformten Antriebsschaft 3. Auf dem in Bohrrichtung weisenden offenen Ende des Trägerkörpers 2 sitzen vier insgesamt mit 4 bezeichnete Schneidsegmente, welche die Stirnseite 5 des Trägerkörpers 2 axial und die Umfangskontur des Trägerkörpers 2 radial überragen.The hollow drill, designated as a whole by 1, consists of a hollow cylindrical carrier body 2 with a drive shaft 3 molded onto the end facing away from the drilling direction and project radially beyond the circumferential contour of the carrier body 2.

Die Schneidsegmente 4 verfügen über eine in Bohrrichtung weisende Stirnfläche 6 und über eine sich konzentrisch zur Umfangskontur des Trägerkörpers 2 erstreckende Oberflächen­schicht 7, welche sich auch entgegen der Bohrrichtung, an­schliessend an die Stirnseite 5 entlang der Umfangskontur des Trägerkörpers 2 mit einem Abschnitt 8 erstreckt. Die Schneidsegmente 4 bestehen aus einem Einbettungsmaterial, zB Kobalt mit metallischen Zusätzen wie Kupfer, Zinn, Zink, Wolfram, in welchem Diamantkorn 9 räumlich verteilt einge­bettet ist. In der Oberflächenschicht 7 beträgt die Diamant­korn-Konzentration das Zwei- bis Fünffache des übrigen Be­reichs der Schneidsegmente 4, wie dies die Fig. 2 verdeut­licht. Die Dicke der Oberflächenschicht 7 beträgt 0,2 bis 1 mm.The cutting segments 4 have an end face 6 pointing in the drilling direction and a surface layer 7 which extends concentrically to the circumferential contour of the carrier body 2 and which also extends counter to the drilling direction and then to the end face 5 along the circumferential contour of the carrier body 2 with a section 8. The Cutting segments 4 consist of an embedding material, for example cobalt with metallic additives such as copper, tin, zinc, tungsten, in which diamond grain 9 is embedded in a spatially distributed manner. In the surface layer 7, the diamond grain concentration is two to five times the remaining area of the cutting segments 4, as shown in FIG. 2. The thickness of the surface layer 7 is 0.2 to 1 mm.

Zufolge der grösseren Diamantkorn-Konzentration in der Ober­flächenschicht 7 wird hohe radiale Verschleissfestigkeit der Schneidsegmente 4 erzielt, so dass mit dem Hohlbohrer 1 eine grosse Anzahl Bohrlöcher von hoher Durchmessergenauigkeit hergestellt werden kann.As a result of the greater diamond grain concentration in the surface layer 7, high radial wear resistance of the cutting segments 4 is achieved, so that a large number of drill holes of high diameter accuracy can be produced with the hollow drill 1.

Claims (6)

1. Hohlbohrer (1) mit einem hohlzylindrischen Trägerkörper (2), an dessen bohrrichtungsseitigem offenen Ende die Stirnseite und die Umfangskontur des Trägerkörpers (2) überragende, Diamantkorn (9) enthaltende Schneidsegmente (4) angeordnet sind, dadurch gekenn­zeichnet, dass die Schneidsegmente (4) eine sich konzentrisch zur Umfangskontur des Trägerkörpers (2) erstreckende Oberflächenschicht (7) mit einer gegenüber dem übrigen Bereich der Schneidsegmente (4) höheren Diamantkorn-Konzentration aufweisen.1. Hollow drill (1) with a hollow cylindrical carrier body (2), on the drilling direction side open end of which the end face and the peripheral contour of the carrier body (2) projecting, diamond grain (9) containing cutting segments (4) are arranged, characterized in that the cutting segments ( 4) have a surface layer (7) which extends concentrically to the circumferential contour of the carrier body (2) and which has a higher diamond grain concentration than the rest of the cutting segments (4). 2. Hohlbohrer nach Anspruch 1, dadurch gekennzeichnet, dass die in Umfangsrichtung gemessene Erstreckung der Oberflächenschicht (7) derjenigen der Schneidsegmente (4) entspricht.2. Hollow drill according to claim 1, characterized in that the extent of the surface layer (7) measured in the circumferential direction corresponds to that of the cutting segments (4). 3. Hohlbohrer nach Anspruch 1 oder 2, dadurch gekenn­zeichnet, dass die in Achsrichtung des Bohrers (1) ge­messene Erstreckung der Oberflächenschicht (7) der­jenigen der Schneidsegmente (4) entspricht.3. Hollow drill according to claim 1 or 2, characterized in that the extent of the surface layer (7) measured in the axial direction of the drill (1) corresponds to that of the cutting segments (4). 4. Hohlbohrer nach Anspruch 1 oder 2, dadurch gekenn­zeichnet, dass die in Achsrichtung des Bohrers ge­messene Erstreckung der Oberflächenschicht (7) die in Achsrichtung gemessene, die Stirnseite (5) des Trägerkörpers (2) überragende Erstreckung der Schneidsegmente (4) übersteigt.4. Hollow drill according to claim 1 or 2, characterized in that the extension of the surface layer (7) measured in the axial direction of the drill exceeds the extension of the cutting segments (4) which is measured in the axial direction and which projects over the end face (5) of the carrier body (2). 5. Hohlbohrer nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, dass die Diamantkorn-Konzentration in der Oberflächenschicht (7) dem Zwei- bis Fünffachen der Diamantkorn-Konzentration im übrigen Bereich der Schneidsegmente (4) entspricht.5. Hollow drill according to one of claims 1 to 4, characterized in that the diamond grain concentration in the surface layer (7) corresponds to two to five times the diamond grain concentration in the remaining region of the cutting segments (4). 6. Hohlbohrer nach einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, dass die Oberflächenschicht (7) eine Dicke von 0,2 bis 1 mm aufweist.6. Hollow drill according to one of claims 1 to 5, characterized in that the surface layer (7) has a thickness of 0.2 to 1 mm.
EP19870810686 1987-03-02 1987-11-23 Hollow drill tool Withdrawn EP0280835A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3706641 1987-03-02
DE19873706641 DE3706641A1 (en) 1987-03-02 1987-03-02 HOLLOW DRILL

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EP0280835A1 true EP0280835A1 (en) 1988-09-07

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EP19870810686 Withdrawn EP0280835A1 (en) 1987-03-02 1987-11-23 Hollow drill tool

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JP (1) JPS63230306A (en)
AU (1) AU1125488A (en)
DE (1) DE3706641A1 (en)

Cited By (11)

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EP0363313A2 (en) * 1988-10-05 1990-04-11 HILTI Aktiengesellschaft Hollow stone-drilling tool
WO1990015683A1 (en) * 1989-06-14 1990-12-27 Tyrolit Schleifmittelwerke Swarovski K.G. Hollow drill
EP0514822A1 (en) * 1991-05-23 1992-11-25 FRIEDRICH BUSSE DIAMANTWERKZEUGE GmbH + Co. Tool for working concrete or similar materials
EP0857552A2 (en) * 1997-01-27 1998-08-12 Tyrolit Schleifmittelwerke Swarovski KG Stone cutting element with increased wear resistance
GB2423540A (en) * 2005-02-24 2006-08-30 Marcrist Internat Ltd Core drills and cutting discs
GB2423538A (en) * 2005-02-24 2006-08-30 Marcrist Internat Ltd Core drilling segments with side protection
KR100968930B1 (en) 2008-05-29 2010-07-14 가부시키 가이샤 미야나가 Diamond Core Drill
CN102059376A (en) * 2010-12-15 2011-05-18 杨清韩 Cylindrical hollow drilling tool
DE202015104880U1 (en) 2015-09-15 2015-11-03 Jakob Lach Gmbh & Co. Kg hollow drill
CN106424855A (en) * 2016-12-26 2017-02-22 王文胜 Diamond bit
CN110735602A (en) * 2019-10-31 2020-01-31 广州晶体科技有限公司 core bit

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Publication number Priority date Publication date Assignee Title
US5429199A (en) * 1992-08-26 1995-07-04 Kennametal Inc. Cutting bit and cutting insert
JPH08155946A (en) * 1994-11-30 1996-06-18 Tone Corp Inner and outer diameter part reinforced diamond bit and production thereof
JP4785185B2 (en) * 2005-12-27 2011-10-05 信越石英株式会社 Inner hole processing method of hollow brittle material

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US4561810A (en) * 1981-12-16 1985-12-31 General Electric Company Bi-level cutting insert
US4505251A (en) * 1982-02-08 1985-03-19 Martin Stoll Cutting segment with porous center section
EP0102843A2 (en) * 1982-09-06 1984-03-14 De Beers Industrial Diamond Division (Proprietary) Limited Tool inserts
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US4610579A (en) * 1984-05-31 1986-09-09 Ppg Industries, Inc. Core drill bit with dynamic cooling fluid flow control means

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0363313A2 (en) * 1988-10-05 1990-04-11 HILTI Aktiengesellschaft Hollow stone-drilling tool
EP0363313A3 (en) * 1988-10-05 1990-12-27 Hilti Aktiengesellschaft Hollow stone-drilling tool
WO1990015683A1 (en) * 1989-06-14 1990-12-27 Tyrolit Schleifmittelwerke Swarovski K.G. Hollow drill
EP0514822A1 (en) * 1991-05-23 1992-11-25 FRIEDRICH BUSSE DIAMANTWERKZEUGE GmbH + Co. Tool for working concrete or similar materials
EP0857552A2 (en) * 1997-01-27 1998-08-12 Tyrolit Schleifmittelwerke Swarovski KG Stone cutting element with increased wear resistance
EP0857552A3 (en) * 1997-01-27 2000-02-09 Tyrolit Schleifmittelwerke Swarovski KG Stone cutting element with increased wear resistance
GB2423540A (en) * 2005-02-24 2006-08-30 Marcrist Internat Ltd Core drills and cutting discs
GB2423538A (en) * 2005-02-24 2006-08-30 Marcrist Internat Ltd Core drilling segments with side protection
GB2423537A (en) * 2005-02-24 2006-08-30 Marcrist Internat Ltd Core drills
KR100968930B1 (en) 2008-05-29 2010-07-14 가부시키 가이샤 미야나가 Diamond Core Drill
CN102059376A (en) * 2010-12-15 2011-05-18 杨清韩 Cylindrical hollow drilling tool
DE202015104880U1 (en) 2015-09-15 2015-11-03 Jakob Lach Gmbh & Co. Kg hollow drill
CN106424855A (en) * 2016-12-26 2017-02-22 王文胜 Diamond bit
CN110735602A (en) * 2019-10-31 2020-01-31 广州晶体科技有限公司 core bit

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DE3706641A1 (en) 1988-09-15
JPS63230306A (en) 1988-09-26
AU1125488A (en) 1988-09-01

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