CN104854299A - Rock bit tip and rock bit - Google Patents

Rock bit tip and rock bit Download PDF

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Publication number
CN104854299A
CN104854299A CN201380059999.0A CN201380059999A CN104854299A CN 104854299 A CN104854299 A CN 104854299A CN 201380059999 A CN201380059999 A CN 201380059999A CN 104854299 A CN104854299 A CN 104854299A
Authority
CN
China
Prior art keywords
apex point
installation
groove
drill bit
rock
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
Application number
CN201380059999.0A
Other languages
Chinese (zh)
Inventor
卡尔-奥斯卡·芬曼
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sandvik Intellectual Property AB
Original Assignee
Sandvik Intellectual Property AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to EP12195889.6A priority Critical patent/EP2740884B1/en
Priority to EP12195889.6 priority
Application filed by Sandvik Intellectual Property AB filed Critical Sandvik Intellectual Property AB
Priority to PCT/EP2013/074734 priority patent/WO2014086620A1/en
Publication of CN104854299A publication Critical patent/CN104854299A/en
Pending legal-status Critical Current

Links

Classifications

    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21BEARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B10/00Drill bits
    • E21B10/46Drill bits characterised by wear resisting parts, e.g. diamond inserts
    • E21B10/56Button-type inserts
    • E21B10/567Button-type inserts with preformed cutting elements mounted on a distinct support, e.g. polycrystalline inserts
    • E21B10/573Button-type inserts with preformed cutting elements mounted on a distinct support, e.g. polycrystalline inserts characterised by support details, e.g. the substrate construction or the interface between the substrate and the cutting element
    • E21B10/5735Interface between the substrate and the cutting element
    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21BEARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B10/00Drill bits
    • E21B10/08Roller bits
    • E21B10/16Roller bits characterised by tooth form or arrangement
    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21BEARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B10/00Drill bits
    • E21B10/42Rotary drag type drill bits with teeth, blades or like cutting elements, e.g. fork-type bits, fish tail bits
    • E21B10/43Rotary drag type drill bits with teeth, blades or like cutting elements, e.g. fork-type bits, fish tail bits characterised by the arrangement of teeth or other cutting elements
    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21BEARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B10/00Drill bits
    • E21B10/46Drill bits characterised by wear resisting parts, e.g. diamond inserts
    • E21B10/56Button-type inserts
    • E21B10/567Button-type inserts with preformed cutting elements mounted on a distinct support, e.g. polycrystalline inserts
    • E21B10/573Button-type inserts with preformed cutting elements mounted on a distinct support, e.g. polycrystalline inserts characterised by support details, e.g. the substrate construction or the interface between the substrate and the cutting element
    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21CMINING OR QUARRYING
    • E21C35/00Miscellaneous items relating to machines for slitting or completely freeing the mineral from the seam
    • E21C35/18Mining picks; Holders therefor
    • E21C35/183Mining picks; Holders therefor with inserts or layers of wear-resistant material
    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21CMINING OR QUARRYING
    • E21C35/00Miscellaneous items relating to machines for slitting or completely freeing the mineral from the seam
    • E21C35/18Mining picks; Holders therefor
    • E21C35/183Mining picks; Holders therefor with inserts or layers of wear-resistant material
    • E21C35/1831Fixing methods or devices

Abstract

A rock bit tip (120) comprising a mounting portion (122), an end portion (11) converging from a top end of the mounting portion to form a work surface and at least one recess (125) in a bottom (124) of the mounting portion, the recess extending towards said end portion, wherein there are more than one recess. The invention further relates to a rock bit.

Description

Rock drill bit apex point and rock drill bit
Technical field
The disclosure relates to the apex point in the rock drill bit or mine drilling bit used in rock excavation equipment.
The present invention particularly has the apex point of hollow base.
Background technology
Formation drilled has multiple distinct methods.Some adopt rotary motion, and some adopt the combination of rotation and ballistic motion.A common aspect of these methods is that drill bit rotates at drill string end place.
Carry out rotation Drilling by the rigid drilling of Rotational Coronary bar, Rock Cutting drill bit is then attached to this rigid drilling.Rotate Drilling and apply two elemental motions (i.e. axial advance and rotation torque) to enter rock by means of drilling rod and drill bit.Impact Drilling mainly through utilize drill bit repeat apply high frequency, high energy strike with pulverize and breaking rock carrys out fractured rock.Impact energy is produced by means of the piston clashing into drill bit (hidden hole drilling) or drill steel (surperficial installing drill).
For improving the abrasion resistance of this drill bit and increasing the life-span, the cutting element of apex point or form of a blade is attached to drill body.Had high rigidity and high tenacity concurrently because carbide alloy is fabulous, these apex points are made up of carbide alloy usually, are modally made up of tungsten carbide.This apex point also can be made up of polycrystalline diamond (PCD).The object of apex point mainly applies pressure and fractured rock to rock.Sometimes, apex point is also positioned at the protection as surrounding steel on drill body.Thus this apex point must bear high compression forces and transverse load.
Tungsten carbide apex point is arranged in the cylinder shape groove in the external surface of drill body usually.This apex point can be made into a few percent millimeter larger than groove, and is pressed into and has interference fit closely, to prevent from unclamping in use.
Tungsten carbide apex point also for soft machining condition, as the excavation of coal.In this application, apex point is commonly referred to cap, and is usually bonded to pick body by such as solder brazing or melting welding.
Multiple standards shape is applied to tungsten carbide apex point, as Part-spherical, taper, biconial, trajectory shape with cut a hole crown.These difformity common ground are that the matrix (also referred to as installation portion) of apex point is normally columniform.
In many applications, the apex point with 2 centimetres or larger diameter is used to be favourable.Advantage is, needs to use less apex point, is also that the apex point projection from bit-body face is outstanding can be comparatively large, maintains enough intensity simultaneously, to avoid occurring laterally losing efficacy in excavation operation.Large apex point by Load concentration to less apex point, and can obtain larger rock penetration ability, and does not engage steel surface, and result just improves rate of excavation.The life-span of drill bit is too increased, because large apex point can allow the wearing and tearing of considerable amount before it is ground away from the large apex point of the larger distance of drill bit extension.
A problem of major diameter apex point is that they are expensive.This is that material cost owing to manufacturing needed for apex point is high.The material quantity needed is along with apex point diameter is in a square increase.When using tungsten carbide, use a small amount of apex point with about 2 cm diameters more than using the cost of relatively large little apex point.
This problem in U.S. Patent No. 4,150, solved in 728.There is illustrated the tungsten carbide apex point with hollow base.This apex point has the cavity of the inner leading to apex point, and its volume is in the scope of about 15-30% of the volume in apex point base portion portion.
, multiple distinct issues can be there are at the apex point place with hollow base in inventor's discovery unexpectedly of the application.A problem is that apex point base portion trend obtains elliptical shape.Another problem is that the form trend of apex point obtains taper, that is: when close to bottom apex point time, the diameter of installation portion reduces.The ovality of installation portion and tapering decrease for the power from drill body pull-out apex point, and therefore the loosening of apex point is disadvantageous consequence.
Another problem is that installation portion breaks when may be press-fitted at apex point in the groove in drill body.
By the detailed description and the accompanying drawings, these and other aspect of the present invention and advantage are apparent.
Summary of the invention
An object of the present invention is to provide the design of a kind of hollow apex point, the intensity of the hollow apex point that the strength ratio of this hollow apex point is known is large.Another object is to provide the hollow apex point can produced at lower cost compared with a kind of and solid apex point and conceives, and therefore solves problem above-mentioned.
According to first aspect, provide a kind of rock drill bit apex point, this rock drill bit apex point comprises: installation portion; End, this end is assembled from installation portion top, to form working surface; With at least one groove in the bottom of installation portion, this groove extends towards described end, wherein there is more than one groove.
In second aspect, provide a kind of rock drill bit, this rock drill bit comprises the apex point with more than one groove.
Accompanying drawing explanation
Accompanying drawing is with reference to, wherein in detailed description of the present invention
Fig. 1 schematically shows the lateral view of conventional apex point or the ball tooth (button) being suitable for rock excavation;
Fig. 2 schematically shows the lateral view of rotary drilling boring tool;
Fig. 3 schematically shows the phantom drawing of the Churn drill boring tool from top;
Fig. 4 schematically shows the lateral view of exploitation pick;
Fig. 5 a schematically shows the phantom drawing of the first embodiment according to apex point of the present invention from below;
Fig. 5 b schematically shows the axial cross-sectional view through apex point central axis A of the first embodiment according to apex point of the present invention;
Fig. 6 schematically shows the phantom drawing of the second embodiment according to apex point of the present invention from below;
Fig. 7 schematically shows the phantom drawing of the 3rd embodiment according to apex point of the present invention from below;
Fig. 8 schematically shows the phantom drawing of the 4th embodiment according to apex point of the present invention from below;
Fig. 9 a schematically shows the phantom drawing of the 5th embodiment according to apex point of the present invention from below;
Fig. 9 b schematically shows the lateral view of the apex point according to Fig. 9 a;
Fig. 9 c schematically shows the apex point according to the line IXC-IXC in Fig. 9 b; And
Fig. 9 d schematically shows the apex point according to the line IXD-IXD in 9b.
Detailed description of the invention
The detailed description of reading in conjunction with the drawings below well understands the features and advantages of the present invention, and wherein similar reference numerals indicates similar element, and wherein:
Fig. 1 shows the apex point 10 being suitable for rock excavation.This apex point comprises the end 11 with top 13.The expection of this end is given prominence to from the front surface of drill bit, to form the working surface with rock contact.Apex point also comprises the installation portion 12 extended towards bottom 14 from end 11.The installation portion expection of this drill bit is positioned in the groove in drill body, and guarantees that apex point is fixed firmly to drill body.If apex point 10 is included in exploitation pick (pick), then bottom 14 can be fixed to drill bit as by solder brazing or melting welding.
Fig. 2 illustrates the rock drill bit 20 for rotating Drilling.This drill bit comprises screw thread 24, by means of this screw thread 24, rotary drilling-head 20 is connected to drill string.This drill bit comprises leg 25 further, and gear wheel (roller cone) 21 is attached to one end place of leg 25.The apex point of type described herein can be used as the protection apex point 23 on leg 25 and/or is used as the effect apex point 22 on gear wheel 21.The main purpose that term " protection " is meant to apex point 23 is that steel in protection drill bit is from too heavy wear.The main purpose that term " effect " is meant to apex point 22 applies pressure to rock and makes rock rupture.In U.S. Patent No. 6,446, in 739, this technology is body more closely described.
Fig. 3 illustrates impactite aiguille 30, and this impactite aiguille 30 comprises drill bit head 31 and shank 32.This drill bit head 31 can comprise the apex point of following type, as periphery apex point 33 and/or front apex point 34.In U.S. Patent No. 7,296, in 641, this technology is body more closely described.
Fig. 4 illustrates and is such as cutting the exploitation pick 40 used in the operation of soft mineral such as coal.This exploitation pick 40 comprises the body 41 with head 42 and shank 43.This apex point 44 is constructed in accordance and is make that part that land used cuts mineral.This apex point 44 by hard material as carbide alloy, diamond, SiC-D or its composition are made.In U.S. Patent No. 8,210, have in 618 and body more closely describe this technology.
Fig. 5 a and 5b shows first embodiment of the invention.Apex point 110 has installation portion 112.Four identical open recess 115 axially extend from the bottom 114 of installation portion 112.The cross section of open recess 115 at bottom 114 place can be similar to the circular sector of the fillet had for avoiding stress to concentrate substantially.Groove 115 is spaced apart by braced structures 116.At least one open recess 115 has the geometric centre axes B separated with longitudinal apex point central axis A.
Fig. 6 shows the second embodiment of the present invention.Apex point 120 has installation portion 122.Three identical open recess 125 axially extend from the bottom 124 of installation portion 122.The cross section of open recess 125 at bottom 124 place can be similar to butt annulus substantially.Groove 125 is spaced apart by braced structures 126.At least one open recess 125 has the geometric centre axes B separated with longitudinal apex point central axis A.
Fig. 7 illustrates third embodiment of the invention.Apex point 130 has installation portion 132.Seven identical open recess 135 axially extend from the bottom 134 of installation portion 132.Open recess 135 is substantially hexagon at the cross section at bottom 134 place.Groove 135 is spaced apart by braced structures 136.At least one open recess 135 has the geometric centre axes B separated with longitudinal apex point central axis A.Central open groove 135 has the geometric centre axes B substantially overlapped with longitudinal apex point central axis A.
Fig. 8 illustrates fourth embodiment of the invention.Apex point 140 has installation portion 142.Six open recess 145 axially extend from the bottom 144 of installation portion 142.Open recess 145 is substantially circle at the cross section at bottom 134 place.Groove 145 is spaced apart by braced structures 146.At least one open recess 145 has the geometric centre axes B separated with longitudinal apex point central axis A.
Fig. 9 a-9d illustrates fifth embodiment of the invention.Apex point 150 has installation portion 152.An open recess 155 axially extends from the bottom 154 of installation portion 152.Between bottom 154 and end, open recess 155 is divided into three identical independent grooves 157.Groove 157 is spaced apart by braced structures 156.As shown in figure 9d, at least one groove in these grooves 157 bottom installation portion and between end, at least one cross section (IXD-IXD) of the bottom that is parallel to installation portion has the geometric centre axes B separated with longitudinal apex point central axis A.
The example that the number of groove and size comparability thereof describe in above-described embodiment and changing.Also can combine in new embodiment and be of different sizes the groove with shape.The degree of depth of groove also can change, but groove is blind hole type all the time.
The present invention is not restricted to the above embodiments.Different alternative embodiments, remodeling and equivalent example can be used.Therefore, above-described embodiment should not be regarded as being limited to the invention scope that patent claims book limits.

Claims (11)

1. a rock drill bit apex point, comprising: installation portion (12; 112; 122; 132; 142; 152); End (11), described end (11) are assembled from the top of described installation portion, to form working surface; With the bottom (14 at described installation portion; 114; 124; 134; 144; 154) at least one groove (115 in; 125; 135; 145; 155), described groove extends towards described end,
It is characterized in that there is more than one groove.
2. apex point according to claim 1, wherein said groove is by braced structures (116; 126; 136; 146; 156) spaced apart, described braced structures and described installation portion and described end are one.
3. apex point according to claim 1 and 2, wherein at least one groove (157) has between the bottom of described installation portion and described end, parallel with the described bottom of described installation portion cross section, and the geometric center (B) of described cross section is separated with longitudinal apex point central axis (A).
4. the apex point according to claim 1,2 or 3, wherein at least one groove (115) has at the described bottom place of described installation portion, parallel with the described bottom of the described installation portion cross section being similar to circular sector substantially.
5. the apex point according to claim 1,2 or 3, wherein at least one groove (125) has the cross section at the described bottom place of described installation portion, parallel with the described bottom of described installation portion similar substantially butt annulus.
6. the apex point according to claim 1,2 or 3, wherein at least one groove (135) has and is roughly hexagonal cross section at the described bottom place of described installation portion, parallel with the described bottom of described installation portion.
7. the apex point according to claim 1,2 or 3, wherein at least one groove (145) has at the described bottom place of described installation portion, parallel with the described bottom of the described installation portion cross section being roughly circle.
8. the apex point according to any one in aforementioned claim, wherein said apex point comprises carbide alloy and/or polycrystalline diamond (PCD).
9. apex point according to claim 8, wherein said apex point comprises tungsten carbide.
10. a rock drill bit, is characterized in that described rock drill bit comprises the apex point (10 according to any one in aforementioned claim 1-9; 110; 120; 130; 140; 150).
11. rock drill bits according to claim 10, wherein said rock drill bit is drill bit for rotating Drilling, for impacting drill bit or the exploitation pick of Drilling.
CN201380059999.0A 2012-12-06 2013-11-26 Rock bit tip and rock bit Pending CN104854299A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
EP12195889.6A EP2740884B1 (en) 2012-12-06 2012-12-06 Rock bit tip and rock bit
EP12195889.6 2012-12-06
PCT/EP2013/074734 WO2014086620A1 (en) 2012-12-06 2013-11-26 Rock bit tip and rock bit

Publications (1)

Publication Number Publication Date
CN104854299A true CN104854299A (en) 2015-08-19

Family

ID=47294777

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201380059999.0A Pending CN104854299A (en) 2012-12-06 2013-11-26 Rock bit tip and rock bit

Country Status (12)

Country Link
US (1) US20150308199A1 (en)
EP (1) EP2740884B1 (en)
CN (1) CN104854299A (en)
AU (1) AU2013354372A1 (en)
BR (1) BR112015013113A2 (en)
CA (1) CA2888912A1 (en)
CL (1) CL2015001560A1 (en)
MX (1) MX2015006959A (en)
PE (1) PE20151099A1 (en)
RU (1) RU2015126798A (en)
WO (1) WO2014086620A1 (en)
ZA (1) ZA201503945B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108687353A (en) * 2018-06-20 2018-10-23 深圳市海明润超硬材料股份有限公司 A kind of diamond compact and preparation method

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20190178080A1 (en) * 2014-04-02 2019-06-13 The Sollami Company Diamond insert with heat transfer bore
CA2974075A1 (en) * 2016-08-09 2018-02-09 Varel International Ind., L.P. Durable rock bit for blast hole drilling

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4150728A (en) * 1976-11-26 1979-04-24 Smith International, Inc. Rock drill bit inserts with hollow bases
CN1040247A (en) * 1988-07-20 1990-03-07 克尼曼托公司 The pick of shear
CN1115994A (en) * 1993-04-26 1996-01-31 凯纳迈特公司 Extraction undercut for flanged bits
US20090051212A1 (en) * 2007-08-23 2009-02-26 Sandvik Intellectual Property Ab Reduced volume cutting tip and cutter bit assembly incorporating same

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3388757A (en) * 1967-03-23 1968-06-18 Smith Ind International Inc Hardened inserts for drill bits
US4176725A (en) * 1978-08-17 1979-12-04 Dresser Industries, Inc. Earth boring cutting element enhanced retention system
US4654947A (en) * 1985-12-02 1987-04-07 W. Wesley Perry Drill bit and method of renewing drill bit cutting face
US4893875A (en) * 1988-12-16 1990-01-16 Caterpillar Inc. Ground engaging bit having a hardened tip
CA2314114C (en) 1999-07-19 2007-04-10 Smith International, Inc. Improved rock drill bit with neck protection
US20050146199A1 (en) * 2004-01-05 2005-07-07 Wen-Chin Lee Rotatable cutting tool for breaking hard material
SE530135C2 (en) 2004-09-21 2008-03-11 Sandvik Intellectual Property Rock drill bit adapted for striking drilling
US7703559B2 (en) * 2006-05-30 2010-04-27 Smith International, Inc. Rolling cutter
US8500210B2 (en) * 2006-08-11 2013-08-06 Schlumberger Technology Corporation Resilient pick shank
US8500209B2 (en) * 2006-08-11 2013-08-06 Schlumberger Technology Corporation Manually rotatable tool
US7992944B2 (en) * 2006-08-11 2011-08-09 Schlumberger Technology Corporation Manually rotatable tool
US8701799B2 (en) * 2009-04-29 2014-04-22 Schlumberger Technology Corporation Drill bit cutter pocket restitution
WO2010144837A2 (en) * 2009-06-12 2010-12-16 Smith International, Inc. Cutter assemblies, downhole tools incorporating such cutter assemblies and methods of making such downhole tools

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4150728A (en) * 1976-11-26 1979-04-24 Smith International, Inc. Rock drill bit inserts with hollow bases
CN1040247A (en) * 1988-07-20 1990-03-07 克尼曼托公司 The pick of shear
CN1115994A (en) * 1993-04-26 1996-01-31 凯纳迈特公司 Extraction undercut for flanged bits
US20090051212A1 (en) * 2007-08-23 2009-02-26 Sandvik Intellectual Property Ab Reduced volume cutting tip and cutter bit assembly incorporating same

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108687353A (en) * 2018-06-20 2018-10-23 深圳市海明润超硬材料股份有限公司 A kind of diamond compact and preparation method

Also Published As

Publication number Publication date
RU2015126798A (en) 2017-01-13
PE20151099A1 (en) 2015-08-06
EP2740884A1 (en) 2014-06-11
MX2015006959A (en) 2015-09-08
US20150308199A1 (en) 2015-10-29
BR112015013113A2 (en) 2017-07-11
ZA201503945B (en) 2017-11-29
AU2013354372A1 (en) 2015-05-14
WO2014086620A1 (en) 2014-06-12
EP2740884B1 (en) 2015-02-25
CL2015001560A1 (en) 2015-08-28
CA2888912A1 (en) 2014-06-12

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Application publication date: 20150819