EP0395608A2 - Tool for cutting solid material - Google Patents
Tool for cutting solid material Download PDFInfo
- Publication number
- EP0395608A2 EP0395608A2 EP90850135A EP90850135A EP0395608A2 EP 0395608 A2 EP0395608 A2 EP 0395608A2 EP 90850135 A EP90850135 A EP 90850135A EP 90850135 A EP90850135 A EP 90850135A EP 0395608 A2 EP0395608 A2 EP 0395608A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- cutting insert
- content
- phase
- binder phase
- tool
- 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- Withdrawn
Links
- 239000011343 solid material Substances 0.000 title claims abstract description 7
- 238000005219 brazing Methods 0.000 claims abstract description 11
- 239000011230 binding agent Substances 0.000 claims description 24
- 239000002344 surface layer Substances 0.000 claims description 22
- 239000010410 layer Substances 0.000 claims description 20
- 239000010941 cobalt Substances 0.000 claims description 12
- 229910017052 cobalt Inorganic materials 0.000 claims description 12
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 12
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims 4
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims 4
- 229910052742 iron Inorganic materials 0.000 claims 2
- 229910052759 nickel Inorganic materials 0.000 claims 2
- 229910052500 inorganic mineral Inorganic materials 0.000 description 14
- 239000011707 mineral Substances 0.000 description 14
- 239000000463 material Substances 0.000 description 10
- 239000010426 asphalt Substances 0.000 description 9
- 238000010586 diagram Methods 0.000 description 8
- 229910000831 Steel Inorganic materials 0.000 description 3
- 238000005452 bending Methods 0.000 description 3
- 239000010959 steel Substances 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C29/00—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides
- C22C29/02—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides
- C22C29/06—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides based on carbides, but not containing other metal compounds
- C22C29/08—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides based on carbides, but not containing other metal compounds based on tungsten carbide
-
- 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
- E21B10/56—Button-type inserts
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21C—MINING OR QUARRYING
- E21C35/00—Details of, or accessories for, machines for slitting or completely freeing the mineral from the seam, not provided for in groups E21C25/00 - E21C33/00, E21C37/00 or E21C39/00
- E21C35/18—Mining picks; Holders therefor
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21C—MINING OR QUARRYING
- E21C35/00—Details of, or accessories for, machines for slitting or completely freeing the mineral from the seam, not provided for in groups E21C25/00 - E21C33/00, E21C37/00 or E21C39/00
- E21C35/18—Mining picks; Holders therefor
- E21C35/183—Mining picks; Holders therefor with inserts or layers of wear-resisting material
- E21C35/1831—Fixing methods or devices
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21C—MINING OR QUARRYING
- E21C35/00—Details of, or accessories for, machines for slitting or completely freeing the mineral from the seam, not provided for in groups E21C25/00 - E21C33/00, E21C37/00 or E21C39/00
- E21C35/18—Mining picks; Holders therefor
- E21C35/183—Mining picks; Holders therefor with inserts or layers of wear-resisting material
- E21C35/1835—Chemical composition or specific material
Definitions
- the present invention relates to a tool for cutting solid material, said tool comprising a tool body and a cutting insert of cemented carbide, said cutting insert being secured to the tool body by brazing.
- the invention also relates to a cutting insert per se.
- the cutting insert When a tool according to the present invention is cutting a relatively hard, solid material, e.g sandstone, the cutting insert will be subjected to very high forces, said forces creating a turning moment that gives rise to tensile stresses in certain portions of the surface of the cutting tip. Also the turning moment will eventually be transformed to the brazed joint.
- a relatively hard, solid material e.g sandstone
- Cutting inserts of cemented carbide that are subjected to high bending stresses must have a high toughness, i.e. lower hardness compared to cutting inserts that are subjected basically to compressive stresses.
- mineral and asphalt cutting lateral forces are present to a relatively high degree. Therefore, cutting inserts of the type having a relatively low hardness and high Co-content are chosen for mineral and asphalt cutting.
- a high Co-content is also favourable in reducing brazing stresses.
- the wear resistance of a cutting insert as described above consequently is low and in no way optimal as regards length of life. It is therefore common to choose big cutting inserts having a big volume of cemented carbide for mineral and asphalt cutting. By way of such an arrangement one can handle the bending stresses and the tool also gets an acceptable length of life.
- cemented carbide cutting insert for cutting mineral and asphalt has a relatively big volume the tool itself is also voluminous. This means that very powerful machines are needed to carry the tools.
- a conventional brazed joint between the cutting insert and the tool body has normally a substantially constant thickness. This means that only a peripheral part of the brazed joint will be active in absorbing the turning moment.
- the technically cuttable material is the hardest material that can be worked by a cutting action.
- the economically cuttable material is the hardest material that can be worked by cutting action in economical superiority to other methods.
- the aim of the present invention is to present a tool and a cutting insert for the cutting of mineral or asphalt, said tool/cutting insert demanding a relatively low energy to perform cutting and has a high wear resistance.
- a preferred embodiment of the tool has a brazed joint that to a greater degree is active in absorbing the turning moment acting upon the cutting insert. Consequently, harder material can thereby be considered economically cuttable.
- the tool according to the invention also to a high degree avoids sparking when working.
- the aim of the present invention is realized by a tool/cutting insert that has been given the characteristics of the appending claims.
- Fig.1 discloses a cutting drum of an excavating machine
- Fig.2 discloses a detail in enlarged scale of a part of a tool carried by the drum
- Fig.3 shows a sectional view of a cutting insert according to the invention
- Fig.4 shows a diagram of how the compressive stresses in the surface layer vary by varying cobalt content
- Fig.5 shows a diagram of how the hardness varies in relation to the distance from the surface of two cutting inserts
- Fig.6 shows a diagram of how the wear is related to the cutting length for a number of cutting inserts
- Fig.7 shows the head of a cutting insert of type B
- Fig.8 shows a tool according to the invention having a preferred design of the brazed joint
- Fig.9 shows a detail in enlarged scale of Fig.8.
- the cutting drum 10 (only partly shown) in Fig.1 carries a number of holders 11 that each support a tool 12 for cutting solid material.
- the cutting drum 10 is rotated in direction of the arrow 13.
- the cutting insert 14 of the tool 12 is subjected to a normal force F N and a force parallell to chord F T .
- the normal force F N is considerably bigger than the force parallel to chord F T .
- the force F N can be up to four times the force F T and in such a case it is at once realized that a portion of the surface of the cutting insert 14 will be subjected to high tensile stresses.
- the cutting insert 14 in Fig.3 has a core 15 of cemented carbide containing eta-phase.
- the core 15 is surrounded by aa intermediate layer 16 of cemented carbide free of etaphase and having a high content of cobalt.
- the surface layer 17 consists of cemented carbide free from eta-phase and having a low content of cobalt.
- An intermediate part of the cutting insert 14 includes a concave portion 18 extending circumferentially around the cutting insert 14.
- the thickness of the surface layer 17 is 0,8 - 4, preferably 1 - 3, of the thickness of the intermediate layer 16.
- the core 15 and the intermediate, cobalt rich layer 16 have high thermal expansivity compared to the surface layer 17. This means that the surface layer 17 will be subjected to high compressive stresses. The bigger the difference in thermal expansivity, i.e. the bigger the difference in cobalt content between the surface layer 17 and the rest of the cutting insert 14, the higher the compressive stresses in the layer 17.
- the content of binder phase in the surface layer 17 is 0,1 - 0,9, preferably 0,2 - 0,7, of the nominal content of binder phase for the cutting insert 14.
- the content of binder phase in the intermediate layer 16 is 1,2 - 3, preferably 1,4 - 2,5, of the nominal content of binder phase for the cutting insert 14.
- the core 15 of cemented carbide containing eta-phase is stiff, hard and wear resistant.
- Said core 15 in combination with an intermediate layer 16 free of eta-phase and having a high content of cobalt and a surface layer 17 free of eta-phase and subjected to high compressive stresses presents a cutting insert 14 that fulfils the requirements discussed above for cutting of mineral and asphalt, i.e. a cutting insert demanding relatively low cutting forces and having a relatively high wear resistance.
- Fig.5 a diagram is disclosed showing the hardness distribution of a cutting insert according to the present invention and a cutting insert of standard cemented carbide, both inserts having a nominal content of cobalt of 15 % by weight.
- the measurments are carried out from the surface up to the centre of the cutting inserts.
- the surface layer 17 of a cutting insert according to the invention has a relatively seen very high hardness up to about 1.5 mm from the surface, said layer 17 having a low content of cobalt.
- the layer 16 having a high content of cobalt has a relatively low hardness.
- the core 15 again has a relatively high hardness.
- the cutting insert of standard cemented carbide has a constant hardness, as can be seen in Fig.5.
- the cutting insert of type A has a geometrical design in accordance with Fig.3.
- the material in said cutting insert is cemented carbide of standard type.
- the cutting insert of type B is of conventional geometrical design for cutting mineral, see Fig.7, and the cutting insert of type C is a cutting insert 14 according to the present invention, i.e. in accordance with Fig.3.
- the cutting insert of type A is worn out to 100% after a cutting length of about 190 m.
- the cutting insert of type B is worn out to about 80% after a cutting length of about 375 m.
- the cutting insert of type C is worn out to about 50% after a cutting length of about 940 m.
- the cutting inserts of type A and C have a weight of 80 g while the cutting insert of type B has a weight of 150 g, i.e. the volume of the cutting insert of type B is almost twice the volume of the cutting inserts of type A and C.
- Fig.7 For a man skilled in the art the results presented in Fig.7 are very surprising.
- the cutting insert according to the present invention has a relatively big axial projection, see e.g. Fig.2.
- the composition of the cutting insert 14 according to Fig.3 makes it possible to handle the relatively big tensile stresses and bending moments that act upon the cutting insert 14 due to its relatively big axial projection.
- a further advantage with a tool according to the present invention is that compared to conventional tools less dust is produced when cutting is effected, i.e. the grain-size distribution is displaced towards bigger grain-size for the cutting insert of the present invention than for a cutting insert of type B, see Fig.7.
- the reason for that is the geometry in combination with the high wear resistance of the cutting insert according to the invention.
- a preferred embodiment of a brazed joint 19 is disclosed.
- the brazed joint 19 is located between the tool body 12 and the cutting insert 14.
- the tool body includes a recess 20 adapted to receive the cutting insert 14.
- the recess 20 has a flat bottom portion 21 located in a plane perpendicular to the longitudinal centre axis 22 of the tool.
- the recess also includes a conical surface portion 23 extending from the bottom portion 21 towards the periphery of the tool body 10.
- the conical portion 23 is symmetrical in respect of the longitudinal centre axis 22.
- the recess 20 also includes an annular surface portion 24 having an extension in the longitudinal direction of the tool.
- annular groove 25 is provided in the conical surface portion 23 , said groove 25 being used for fixation of the cutting insert 14 in the recess.
- the cutting insert 14 has a flat bottom surface 26 adapted to be located above the bottom surface 21 of the recess in mounted position of the cutting insert 14.
- the cutting insert 14 further includes a conical surface portion 27 extending from the bottom surface 26 up to a cylindrical periphery surface 28 of the cutting insert 14, said surface 28 defining the biggest diameter of said cutting insert 14.
- the conical surface portion 27 of the cutting insert is provided with a number of spacing buttons 29 cooperating with the groove 25 in mounted position of the cutting insert 14.
- the buttons 29 and the groove 25 make sure that the cutting insert is in correct position before brazing takes place.
- the conical surface portion 23 of the recess 20 and the conical surface portion 27 of the cutting insert between them include an angle ⁇ that preferably has a value of 2-4°.
- the tool body 10 and the cutting insert 14 are oriented relative to each other as is shown in Figs. 8 and 9, i.e. they have a common longitudinal centre axis 22.
- Brazing is then effected and preferably a copper based brazing alloy is used. It is also preferred to use vacuum brazing.
- the upper surface of the brazed joint 19 is marked by 30 in Fig.9.
- the brazed joint 19 Due to the included angle ⁇ between the conical surface portions 23 and 27 resp., the brazed joint 19 has generally Wedge-like cross-sections in an axial plane through the tool according to the invention. The thickness of the brazed joint 19 is increasing towards the periphery of the cutting insert 14.
- brazed joint I9 is very effective in that almost the entire portion of the brazed joint 19 located between the conical surface portions 23 and 27 resp., is active in absorbing the turning moment acting upon the cutting insert 14. At one side the brazed joint 19 will be subjected to tension forces while the diametrically opposed side will be subjected to compression forces. The most difficult forces to handle are of course the tension forces.
- brazed joint In the area of spring 31 the brazed joint can have a thickness of 0.7 mm and in the area of spring 33 the thickness is 0.3 mm.
- the diameter of the cutting insert 14 is 24 mm measured at the cylindrical periphery surface 28.
- brazed joint described above is not limited to be used with a cutting insert 14 according to the present invention. Also the rest of the invention is of course not restricted to the described embodiments but can be varied freely within the scope of the appending claims.
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Abstract
Description
- The present invention relates to a tool for cutting solid material, said tool comprising a tool body and a cutting insert of cemented carbide, said cutting insert being secured to the tool body by brazing. The invention also relates to a cutting insert per se.
- When a tool according to the present invention is cutting a relatively hard, solid material, e.g sandstone, the cutting insert will be subjected to very high forces, said forces creating a turning moment that gives rise to tensile stresses in certain portions of the surface of the cutting tip. Also the turning moment will eventually be transformed to the brazed joint.
- Cutting inserts of cemented carbide that are subjected to high bending stresses must have a high toughness, i.e. lower hardness compared to cutting inserts that are subjected basically to compressive stresses. In mineral and asphalt cutting lateral forces are present to a relatively high degree. Therefore, cutting inserts of the type having a relatively low hardness and high Co-content are chosen for mineral and asphalt cutting. A high Co-content is also favourable in reducing brazing stresses.
- The wear resistance of a cutting insert as described above consequently is low and in no way optimal as regards length of life. It is therefore common to choose big cutting inserts having a big volume of cemented carbide for mineral and asphalt cutting. By way of such an arrangement one can handle the bending stresses and the tool also gets an acceptable length of life.
- In conventional tools for mineral and asphalt cutting the big volume cutting inserts are properly embedded in the tool blank made out of steel. Such an arrangement makes sure that the cutting insert is not subjected to too high stresses.
- However, such a design means that the steel of the blank surrounding the cutting insert quite soon gets in contact with the mineral or asphalt that is worked. Especially when minerals are worked the contact between minerals and steel will initiate sparking that can be very dangerous, e.g. in mines having inflammable gases. Contact between a cutting insert of cemented carbide and minerals will normally not initiate sparking.
- Since the cemented carbide cutting insert for cutting mineral and asphalt has a relatively big volume the tool itself is also voluminous. This means that very powerful machines are needed to carry the tools.
- As mentioned above the turning moment acting upon the cutting insert will be transferred to the brazed joint. A conventional brazed joint between the cutting insert and the tool body has normally a substantially constant thickness. This means that only a peripheral part of the brazed joint will be active in absorbing the turning moment.
- Especially in mineral cutting one speaks of technically cuttable material and economically cuttable material. The technically cuttable material is the hardest material that can be worked by a cutting action. The economically cuttable material is the hardest material that can be worked by cutting action in economical superiority to other methods.
- The aim of the present invention is to present a tool and a cutting insert for the cutting of mineral or asphalt, said tool/cutting insert demanding a relatively low energy to perform cutting and has a high wear resistance. A preferred embodiment of the tool has a brazed joint that to a greater degree is active in absorbing the turning moment acting upon the cutting insert. Consequently, harder material can thereby be considered economically cuttable. The tool according to the invention also to a high degree avoids sparking when working. The aim of the present invention is realized by a tool/cutting insert that has been given the characteristics of the appending claims.
- Below an embodiment of the tool according to the invention will be described with reference to the accompanying drawings, where Fig.1 discloses a cutting drum of an excavating machine; Fig.2 discloses a detail in enlarged scale of a part of a tool carried by the drum; Fig.3 shows a sectional view of a cutting insert according to the invention; Fig.4 shows a diagram of how the compressive stresses in the surface layer vary by varying cobalt content; Fig.5 shows a diagram of how the hardness varies in relation to the distance from the surface of two cutting inserts; Fig.6 shows a diagram of how the wear is related to the cutting length for a number of cutting inserts; Fig.7 shows the head of a cutting insert of type B; Fig.8 shows a tool according to the invention having a preferred design of the brazed joint; and Fig.9 shows a detail in enlarged scale of Fig.8.
- The cutting drum 10 (only partly shown) in Fig.1 carries a number of
holders 11 that each support atool 12 for cutting solid material. Thecutting drum 10 is rotated in direction of thearrow 13. When atool 12 is in engagement with the material to be worked thecutting insert 14 of thetool 12 is subjected to a normal force FN and a force parallell to chord FT. - If very hard material is worked then the normal force FN is considerably bigger than the force parallel to chord FT. The force FN can be up to four times the force FT and in such a case it is at once realized that a portion of the surface of the
cutting insert 14 will be subjected to high tensile stresses. - In order to handle these high tensile stresses it is necessary to use a special type of cemented carbide disclosed in
EP 0 182 759 andEP 0 247 985. Therefore these publications are included in this specification by way of reference. - The
cutting insert 14 in Fig.3 has acore 15 of cemented carbide containing eta-phase. Thecore 15 is surrounded by aaintermediate layer 16 of cemented carbide free of etaphase and having a high content of cobalt. Thesurface layer 17 consists of cemented carbide free from eta-phase and having a low content of cobalt. An intermediate part of thecutting insert 14 includes aconcave portion 18 extending circumferentially around thecutting insert 14. - The thickness of the
surface layer 17 is 0,8 - 4, preferably 1 - 3, of the thickness of theintermediate layer 16. - The
core 15 and the intermediate, cobaltrich layer 16 have high thermal expansivity compared to thesurface layer 17. This means that thesurface layer 17 will be subjected to high compressive stresses. The bigger the difference in thermal expansivity, i.e. the bigger the difference in cobalt content between thesurface layer 17 and the rest of thecutting insert 14, the higher the compressive stresses in thelayer 17. The content of binder phase in thesurface layer 17 is 0,1 - 0,9, preferably 0,2 - 0,7, of the nominal content of binder phase for thecutting insert 14. The content of binder phase in theintermediate layer 16 is 1,2 - 3, preferably 1,4 - 2,5, of the nominal content of binder phase for thecutting insert 14. - From what is said above it can be realized that a higher nominal cobalt content of the cutting insert gives higher compressive stresses in the surface layer. This is shown by a diagram in Fig.4.
- It should be pointed out that the
core 15 of cemented carbide containing eta-phase is stiff, hard and wear resistant. Saidcore 15 in combination with anintermediate layer 16 free of eta-phase and having a high content of cobalt and asurface layer 17 free of eta-phase and subjected to high compressive stresses presents acutting insert 14 that fulfils the requirements discussed above for cutting of mineral and asphalt, i.e. a cutting insert demanding relatively low cutting forces and having a relatively high wear resistance. - In Fig.5 a diagram is disclosed showing the hardness distribution of a cutting insert according to the present invention and a cutting insert of standard cemented carbide, both inserts having a nominal content of cobalt of 15 % by weight. The measurments are carried out from the surface up to the centre of the cutting inserts. By studying Fig.5 it is at once noticed that the
surface layer 17 of a cutting insert according to the invention has a relatively seen very high hardness up to about 1.5 mm from the surface, saidlayer 17 having a low content of cobalt. Thelayer 16 having a high content of cobalt has a relatively low hardness. Thecore 15 again has a relatively high hardness. - The cutting insert of standard cemented carbide has a constant hardness, as can be seen in Fig.5.
- Tests have been made of the parameter wear relative to the parameter cutting length for three different cutting inserts. Said tests are shown in a diagram in Fig.6.
- The cutting insert of type A has a geometrical design in accordance with Fig.3. However, the material in said cutting insert is cemented carbide of standard type. The cutting insert of type B is of conventional geometrical design for cutting mineral, see Fig.7, and the cutting insert of type C is a
cutting insert 14 according to the present invention, i.e. in accordance with Fig.3. - As can be seen from Fig.7 the cutting insert of type A is worn out to 100% after a cutting length of about 190 m. The cutting insert of type B is worn out to about 80% after a cutting length of about 375 m. The cutting insert of type C is worn out to about 50% after a cutting length of about 940 m. In this connection it should also be pointed out that the cutting inserts of type A and C have a weight of 80 g while the cutting insert of type B has a weight of 150 g, i.e. the volume of the cutting insert of type B is almost twice the volume of the cutting inserts of type A and C.
- For a man skilled in the art the results presented in Fig.7 are very surprising. Compared to conventional cutting inserts for cutting mineral or asphalt the cutting insert according to the present invention has a relatively big axial projection, see e.g. Fig.2. The composition of the cutting
insert 14 according to Fig.3 makes it possible to handle the relatively big tensile stresses and bending moments that act upon the cuttinginsert 14 due to its relatively big axial projection. - A further advantage with a tool according to the present invention is that compared to conventional tools less dust is produced when cutting is effected, i.e. the grain-size distribution is displaced towards bigger grain-size for the cutting insert of the present invention than for a cutting insert of type B, see Fig.7. The reason for that is the geometry in combination with the high wear resistance of the cutting insert according to the invention.
- In Fig.8 and 9 a preferred embodiment of a brazed joint 19 is disclosed. The brazed joint 19 is located between the
tool body 12 and the cuttinginsert 14. The tool body includes arecess 20 adapted to receive the cuttinginsert 14. - In the described embodiment the
recess 20 has aflat bottom portion 21 located in a plane perpendicular to thelongitudinal centre axis 22 of the tool. The recess also includes aconical surface portion 23 extending from thebottom portion 21 towards the periphery of thetool body 10. - The
conical portion 23 is symmetrical in respect of thelongitudinal centre axis 22. - The
recess 20 also includes anannular surface portion 24 having an extension in the longitudinal direction of the tool. - In the
conical surface portion 23 anannular groove 25 is provided, saidgroove 25 being used for fixation of the cuttinginsert 14 in the recess. - The cutting
insert 14 according to the described embodiment has aflat bottom surface 26 adapted to be located above thebottom surface 21 of the recess in mounted position of the cuttinginsert 14. - The cutting
insert 14 further includes aconical surface portion 27 extending from thebottom surface 26 up to acylindrical periphery surface 28 of the cuttinginsert 14, saidsurface 28 defining the biggest diameter of said cuttinginsert 14. - The
conical surface portion 27 of the cutting insert is provided with a number ofspacing buttons 29 cooperating with thegroove 25 in mounted position of the cuttinginsert 14. Thebuttons 29 and thegroove 25 make sure that the cutting insert is in correct position before brazing takes place. - As is indicated in Fig.8 the
conical surface portion 23 of therecess 20 and theconical surface portion 27 of the cutting insert between them include an angle α that preferably has a value of 2-4°. Thesurface portions - From Fig.9 it can be learnt that the bottom surfaces 29 and 26 resp., are at a small distance from each other in the disclosed embodiment.
- When brazing is about to take place the
tool body 10 and the cuttinginsert 14 are oriented relative to each other as is shown in Figs. 8 and 9, i.e. they have a commonlongitudinal centre axis 22. - Brazing is then effected and preferably a copper based brazing alloy is used. It is also preferred to use vacuum brazing. The upper surface of the brazed joint 19 is marked by 30 in Fig.9.
- Due to the included angle α between the
conical surface portions insert 14. - This described design of the brazed joint I₉ is very effective in that almost the entire portion of the brazed joint 19 located between the
conical surface portions insert 14. At one side the brazed joint 19 will be subjected to tension forces while the diametrically opposed side will be subjected to compression forces. The most difficult forces to handle are of course the tension forces. - In order to describe the function of the brazed joint according to the present invention it could be looked upon as a number of elastical springs 31, 32, and 33. In such a case the in radial direction outer portion of the brazed joint will be more extended/compressed than the inner portions. Although the springs 31-33 are extended/compressed to a different degree they exert substantially the same force due to their different lengths. This is illustrated by the diagram in Fig.9. The vertical axis indicates the force F and the horizontal axis indicates the extension E. The disclosed brazed joint of Fig.9 is subjected to a turning moment M and it is realized at once that the springs 31-33 are subjected to tension forces that in a conventional way are negative in the diagram. The tension force in each spring 31-33 is the same while the extensions are different. Of course this theory will not be fulfilled completely in practice but the principle is important.
- A preferred but non-limiting dimensional example of the brazed joint can be given. In the area of spring 31 the brazed joint can have a thickness of 0.7 mm and in the area of spring 33 the thickness is 0.3 mm. The diameter of the cutting
insert 14 is 24 mm measured at thecylindrical periphery surface 28. - In this connection it should be pointed out that the brazed joint described above is not limited to be used with a cutting
insert 14 according to the present invention. Also the rest of the invention is of course not restricted to the described embodiments but can be varied freely within the scope of the appending claims.
Claims (12)
characterized in that an intermediate portion of the cutting insert (14), seen in axial direction of the cutting insert (14), includes a concave portion (18) extending circumferentially around the cutting insert (14), that the cutting insert (14) comprises a core (15) of cemented carbide, an intermediate layer (16) of cemented carbide surrounding said core (15) and a surface layer (17) of cemented carbide, that the surface layer (17), the intermediate layer (16) and the core (15) contain WC (alpha-phase) with a binder phase (beta-phase) based upon at least one of cobalt, nickel or iron, that the core (15) further contains eta-phase, that the intermediate layer (16) and the surface layer (17) is free of eta-phase, that the content of binder phase in the surface layer (17) is lower than the nominal content of binder phase for the cutting insert (14), and that the content of binder phase in the intermediate layer (16) is higher than the nominal content of binder phase for the cutting insert (14).
characterized in that the content of eta-phase in the core (15) of the cutting insert (14) is 2 - 60 % by volume, preferably 10 - 35 % by volume.
characterized in that the nominal content of binder phase in the cutting insert (14) is 8 - 20 % per weight, preferably 11 - 16 %.
characterized in that the content of binder phase in the surface layer (17) is 0,8 - 4, preferably 1 - 3, of the nominal content of binder phase for the cutting insert (14), and that the content of binder phase in the intermediate layer (16) is 1,2 - 3, preferably 1,4 - 2,5, of the nominal content of binder phase for the cutting insert (14).
characterized in that the thickness of the surface layer (17) is 0,8 - 4, preferably 1 - 3, of the thickness of the intermediate layer (16).
characterized in that the brazed joint (19) between the cutting insert (14) and the tool body (12) has at least partially an increasing thickness in direction from the centre of the cutting insert (14) towards the periphery of the cutting insert (14).
characterized in that the brazed joint (19) has generally wedge-like cross-sections in an axial plane of the tool.
characterized in that the content of eta-phase in the core (15) is 2 - 60 % by volume, preferably 10 - 35 % by volume.
characterized in that the nominal content of binder phase is 9 - 20 % per weight, preferably 11 - 16 %.
characterized in that the content of binder phase in the surface layer (17) is 0,8 - 4, preferably 1 - 3, of the nominal content of binder phase for the cutting insert (14), and that the content of binder phase in the intermediate layer (16) is 1,2 - 3, preferably 1,4 - 2,5, of the nominal content of binder phase for the cutting insert (14).
characterized in that the thickness of the surface layer (17) is 0,8 - 4, preferably 1 - 3, of the thickness of the intermediate layer (16).
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SE8901482 | 1989-04-24 | ||
SE8901482A SE463574B (en) | 1989-04-24 | 1989-04-24 | TOOLS AND CUTS OF HEAVY METAL FOR CERTAIN PROCESSING OF SOLID MATERIALS |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0395608A2 true EP0395608A2 (en) | 1990-10-31 |
EP0395608A3 EP0395608A3 (en) | 1991-01-02 |
Family
ID=20375770
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19900850135 Withdrawn EP0395608A3 (en) | 1989-04-24 | 1990-04-09 | Tool for cutting solid material |
Country Status (5)
Country | Link |
---|---|
EP (1) | EP0395608A3 (en) |
JP (1) | JP2877434B2 (en) |
AU (1) | AU633893B2 (en) |
CA (1) | CA2015132C (en) |
SE (1) | SE463574B (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0438916A1 (en) * | 1989-12-27 | 1991-07-31 | Sumitomo Electric Industries, Ltd. | Coated cemented carbides and processes for the production of same |
US8210618B2 (en) * | 2007-08-23 | 2012-07-03 | Sandvik Intellectual Property Ab | Reduced volume cutting tip and cutter bit assembly incorporating same |
US8678517B2 (en) | 2007-08-23 | 2014-03-25 | Sandvik Intellectual Property Ab | Reduced volume cutting tip and cutting bit incorporating same |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0122893A1 (en) * | 1983-03-23 | 1984-10-24 | Santrade Ltd. | Excavating tool |
EP0247985A2 (en) * | 1986-05-12 | 1987-12-02 | Santrade Ltd. | Cemented carbide with a binder phase gradient and method of making the same |
EP0182759B1 (en) * | 1984-11-13 | 1989-12-13 | Santrade Ltd. | Cemented carbide body used preferably for rock drilling and mineral cutting |
-
1989
- 1989-04-24 SE SE8901482A patent/SE463574B/en not_active IP Right Cessation
-
1990
- 1990-04-09 EP EP19900850135 patent/EP0395608A3/en not_active Withdrawn
- 1990-04-12 AU AU53200/90A patent/AU633893B2/en not_active Ceased
- 1990-04-23 JP JP2105520A patent/JP2877434B2/en not_active Expired - Fee Related
- 1990-04-23 CA CA002015132A patent/CA2015132C/en not_active Expired - Fee Related
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0122893A1 (en) * | 1983-03-23 | 1984-10-24 | Santrade Ltd. | Excavating tool |
EP0182759B1 (en) * | 1984-11-13 | 1989-12-13 | Santrade Ltd. | Cemented carbide body used preferably for rock drilling and mineral cutting |
EP0247985A2 (en) * | 1986-05-12 | 1987-12-02 | Santrade Ltd. | Cemented carbide with a binder phase gradient and method of making the same |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0438916A1 (en) * | 1989-12-27 | 1991-07-31 | Sumitomo Electric Industries, Ltd. | Coated cemented carbides and processes for the production of same |
US8210618B2 (en) * | 2007-08-23 | 2012-07-03 | Sandvik Intellectual Property Ab | Reduced volume cutting tip and cutter bit assembly incorporating same |
US8678517B2 (en) | 2007-08-23 | 2014-03-25 | Sandvik Intellectual Property Ab | Reduced volume cutting tip and cutting bit incorporating same |
Also Published As
Publication number | Publication date |
---|---|
JPH03111106A (en) | 1991-05-10 |
SE463574B (en) | 1990-12-10 |
JP2877434B2 (en) | 1999-03-31 |
SE8901482D0 (en) | 1989-04-24 |
AU633893B2 (en) | 1993-02-11 |
CA2015132A1 (en) | 1990-10-24 |
EP0395608A3 (en) | 1991-01-02 |
SE8901482L (en) | 1990-10-25 |
CA2015132C (en) | 1996-03-19 |
AU5320090A (en) | 1990-10-25 |
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