CA2245834A1 - Drilling tool for machine tools and method of producing the same - Google Patents
Drilling tool for machine tools and method of producing the same Download PDFInfo
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- CA2245834A1 CA2245834A1 CA 2245834 CA2245834A CA2245834A1 CA 2245834 A1 CA2245834 A1 CA 2245834A1 CA 2245834 CA2245834 CA 2245834 CA 2245834 A CA2245834 A CA 2245834A CA 2245834 A1 CA2245834 A1 CA 2245834A1
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- tool
- sleeve
- shank
- chip
- drilling tool
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Abstract
The invention concerns a drilling tool consisting of a tool head (3) and a tool shank (5) comprising at least one chip groove. A slotted sleeve (10) is placed on the tool shank and closely surrounds said chip groove, the edges (14, 15) adjacent the slot (13) lying on solid material of the tool shank (5). The chip grooves (7) and the sleeve (10) form channels for carrying away the chips removed at the workpiece machining base. Owing to the slot (13), the sleeve (10) can be gently spread apart and pushed onto the tool shank (5) from the end comprising the enlarged tool head (3).
Description
CA 0224~834 1998-08-06 Drilling tool for machine tools and method for produc-ing the same Description The invention is related to a drilling tool for machine tools, comprising a tool head having at least one cut-ting edge, a tool shank joining the tool head and being adapted to be clamped in a tool holder of the machine tool with an end opposed to the tool head, at least one straight or helical chip groove formed into the surface of the shank and extending from the tool head in the direction of chip flow along at least part of the length of the shank, and a sleeve encompassing the tool shank and thereby covering the chip groove at least over a part of its length under formation of a closed chip channel. The invention is further related to a method for manufacturing such a drilling tool.
Drilling tools of the type described above are used for either solid drilling or for boring, profile facing or spot facing of predrilled bores. When drilling into solid material or when finishing pocket bores, the re-moval of chips may be aided by the use of a coolant and lubricant which emerges from the shank tip at a high pressure and washes the chips out of the bore by way of the chip groove. When the chip grooves are radially open, the chips which are forced radially outwards due to the centrifugal force of the tool rotating within ' CA 0224~834 1998-08-06 .
Drilling tools of the type described above are used for either solid drilling or for boring, profile facing or spot facing of predrilled bores. When drilling into solid material or when finishing pocket bores, the re-moval of chips may be aided by the use of a coolant and lubricant which emerges from the shank tip at a high pressure and washes the chips out of the bore by way of the chip groove. When the chip grooves are radially open, the chips which are forced radially outwards due to the centrifugal force of the tool rotating within ' CA 0224~834 1998-08-06 .
the bore travel mainly along the wall of the bore. In pre-drilled bores, in the walls of which recesses such as pockets or cross bores are present, there is the disadvantage that the chips enter the recesses and can-not flow out anymore. The chips then have to be removed in a time consuming further step.
In order to avoid this disadvantage it is known (DE-A-40 33 877) in a drilling tool of the type described above to provide the tool shank with a close-fitting sleeve which extends from the tool head in the direc-tion of the clamped end. The chip grooves and the inner wall of the sleeve thereby delimit channels through which the chips created ln the drilllng process are re-moved. Since the tool head radially protrudes over the circumference of the tool shank and therefore has a larger diameter than the inner diameter o~ the sleeve, in the known drilling tool the sleeve can only be mounted on the tool shank from the clamping end. In drills having a reinforced shank and in stepped drills the fitting of such a sleeve is not possible at all.
Based on this it is the object of the invention to de-velop a drilling tool and a method of productlon thereof, with which closed channels for removing chips can be provided for di~ferent types of drilling tools.
i CA 0224~834 1998-08-06 For the solution of this object the combinations of features of claims 1, 20, 24, 26, 27, and 29 are sug-gested.
The solution according to the invention is based on the idea that the sleeve and/or the tool are designed such that the sleeve can be mounted on the tool shank from the side of the drill tip, in spite of the tool head having a larger diameter than the tool shank.
In order to achieve this it is proposed according to a first variant of the invention that the sleeve has a slot extending over the entirety of its length. The slot makes it possible to spread the sleeve apart so far during mounting that it may be pushed over the thickened tool head and fastened thereto in a tightly fitting manner. The sleeve therefore expediently con-sists of a resilient material, preferably of a spring steel. In order to ensure a secure positioning, it is of advantage when the sleeve lies against the tool shank with its edges which delimit the slot in a sur-face region away from the at least one chip groove. In the case of a helical drill these edges rest on the raised helix turns between the sunk chip grooves.
The slotted sleeve may be clamped onto the tool shank in a friction-fitting manner and/or be affixed to the tool shank in an integral manner by soldering, glueing or welding. In the latter case the sleeve ads to the CA 0224~834 1998-08-06 torsional and flexural stability of the tool as a load carrying member.
In order to prevent an axial movement of the sleeve on the tool shank, the tool head has an axial shoulder acting as a stop for the sleeve, which shoulder is ori-ented in the direction of chip flow. The sleeve may ad-ditionally be connected to the tool shank in a circum-ferential direction in a form-fitting manner. To this end, it expediently comprises at its one end at least one projection which engages a corresponding recess of the stop shoulder. The drilling tool may also be clam-ped such that the sleeve is retained by the tool hol-der, usually a chuck, on the machine side.
When the drilling tool is formed to be a stepped drill, the tool shank of which has at least two shank sections of different diamter with continuous chip grooves, wherein at least one further cutting edge is arranged in the stepped region between the two shank sections, the sleeve may extend over at least one of the shank sections. In order to obtain a closed chip channel, the sleeve is comprised of at least two cylindrical sleeve sections having different diameters, though, which are disposed at an axial distance from one another and which are connected to each other by means of webs which extend over the chip grooves in the stepped regi-on between two shank sections.
CA 0224~834 1998-08-06 A further preferred embodiment of the invention provi-des that the slot of the sleeve is subsequently closed off by addition of material, for instance during the soldering or welding to the tool shank.
With the drilling tool according to the invention the chips stemming from the bottom of the bore can be pus-hed out through the chip channel by the pressure of following chips. The drilling tool according to the in-vention is preferably used in conjunction with a sucti-on device, though, which is either integrated into the tool holder on the machine side or mounted therein.
An advantageous or alternative embodiment of the inven-tion provides that the tool head is adapted to be remo-ved from the tool shank for mounting or exchanging the sleeve. In this case mounting a sleeve which is not slotted from the side of the tip is possible.
A further advantageous or alternative embodiment of the invention therefore provides that the tool shank, toge-ther with the sleeve (10), is adapted to be mounted in the region of its clamping-side end in a suction device on the machine side. By this it is achieved that the chip channel merges into a chip removal conduit of the suction device.
In order to improve the chip removal it is proposed ac-cording to an advantageous embodiment of the invention CA 0224~834 1998-08-06 that the tool shank comprises at least one supply chan-nel for pressurized air and/or a coolant and lubricant, which channel extends up to the tool head and communi-cates thereat in the region of the cutting edge with the chip channel. The pressurized air or the coolant and lubricant is then led through the chip channel to the suction device together with the chips. The pressu-rized air or the coolant and lubricant is supplied eit-her by way of the suction device or centrally by way of a spindle of the machine tool. The chip removal is also made easier when the at least one chip groove has a partial-circular cross section which is complemented by the sleeve to form an essentially circular chip chan-nel.
For the manufacturing of the drilling tool a number of possibilities exist. A first variant of the method con-sists in that a blank of unhardened sheet metal corre-sponding to a development of the sleeve is wound onto a mandrel geometrically corresponding to the tool shank under formation of the slotted sleeve and is resilient-ly hardened, and that the sleeve prepared in this man-ner is pushed over the tool head under widening of the slot and clamped onto the tool shank.
According to a second variant of the method a sheet me-tal is formed in a non-cutting manner over a die or mandrel geometrically corresponding to the tool shank under formation of the sleeve, and the sleeve thus for-CA 0224~834 1998-08-06 med is mounted on the tool shank. In this, the sheet metal is preferably either deep-drawn or extruded.
A third method provides that a pasty, hard metal-containing substance is injected into an injection mould corresponding to the sleeve, and that the sleeve thus formed is then sintered and mounted on the tool shank.
In the two latter variants of the method the sleeve is expediently cut open under formation of the slot and is preferably resiliently hardened, so that the sleeve thus formed may be pushed over the tool head under wi-dening of the slot and clamped onto the tool shank.
In order to improve the glide properties of the sleeve sur~a~e, the sleeve can be surface coated with a pasty hard metal material and heated to cure the coating.
In all variants of the method the sleeve can be inte-grally connected to the tool shank, for example by glu-eing, soldering or welding.
In the following the invention is further described with reference to embodiments schematically shown in the drawing, in which:
~ CA 0224~834 1998-08-06 Fig. la shows a partially cut view of a drilling tool having a glotted sleeve disposed on the tool shank;
Fig. lb shows a development of the slotted sleeve ac-cording to Fig. 1;
Fig. 2 shows a longitudianl section through the dril-ling tool of Fig. 1 in the region of the tool head;
Fig. 3 shows a side view of the drilling tool, which is clamped into a machine tool and connected to a suction and scavaging device;
Fig. 4a shows a side view of a stepped drill with a slotted sleeve;
Fig. 4b shows a side view of the stepped drill of Fig.
4a with the sleeve removed;
Fig. 4c shows a development of the slotted sleeve ac-cording to Fig. 4a.
The drilling tool shown in Fig. 1 and 2has as a core a helical drill 2 which comprises a drill head 3 with two angled cutting edges 4 as well as a tool shank 5 follo-wing the tool head 3. The tool shank 5 comprises two helical chip grooves 7 and ribs 8 disposed inbetween ~ CA 0224~834 1998-08-06 _ g _ the chip grooves 7, which extend ovewr a part of the tool shank from the tool head 3 in the direction of chip flow. The driiling tool 1 can be clamped in the chuck of a machine tool at its groove-free shank end 6.
The tool head 3 has an outer diameter D that is slight-ly larger than the outer diameter d o~ the tool shank 5, so that a step or shoulder 9 is formed between the tool head 3 and the tool shank 5.
A slotted sleeve 10 is disposed on the tool shank 5.
The sleeve 10 is connected to the tool shank 5 in a form- and friction-fitting manner and, if needed, also an integral manner. It is supported with its edge 16 on the shoulder 9 of the tool head 3 and terminates with its opposing edge 18 just before a run-out 11 of the chip grooves 7 which is directed toward the clamping end 6 o~ the tool shank 5. The sleeve 10 has at most the same outer diameter D as the drill head 3, but may also have a slightly smaller diameter.
The sleeve 10 is expediently fabricated ~rom a steel sheet metal blank 12 (Fig. 2) consisting o~ resilient material, wherein the development o~ the sleeve accor-ding to Fig. lb results in a slanted parallelogram. For purposes of orientation the longitudinal axis A of the drilling tool is shown in Fig. lb. The angles o~ the sides 14, 15 o~ the sheet metal blank 12 with respect to the axis A correspond to the angle of ascent o~ the ~ CA 0224~834 1998-08-06 helical rib 8. For the production of the sleeve 10 the sheet metal blank 12 is rolled over a mandrel, so that narrow slot 13 results, which is delimited by the edges 14, 15 of the sheet metal blank 12. The sleeve 10 is positioned on the tool shank 5 in such a manner that the slot 13 runs parallel to one of the ribs 8, wherein the edges 14, 15 delimiting the slot 13 rest on the rib 8.
The sleeve 10 has at its lower edge 16 two projections 16', which engage corrsponding recesses 17 in the shoulder 9 in a form-fitting manner and which thereby hold the sleeve on the tool shank in a non-rotational manner. For a further improvement in this respect the sleeve 10 can be welded to the tool shank 5 with its edges 14 and 15.
As shown in Fig. 3, the drilling tool l can be clamped in a chuck 21 of a machine tool. In the embodiment shown in the figure, there is additionally provided a suction and scavaging device 22 on the machine, into which the drilling tool 1 together with the sleeve 10 may be clamped. During drilling, the cutting edges 4 remove chips from the bottom of a bore in a workpiece (not shown), which chips are continuously suctioned off in the direction of the arrows 27 by way of the chip grooves 7, when the suction device 22 is switched on.
The sleeve lO prevents that the chips contact the bore - CA 0224~834 1998-08-06 wall of the workpiece and thereby degrade the quality of the bore.
In order to ensure a dependable removal of the chips through the chip channels formed between the chip groo-ves 7 and the sleeve 10 without the danger of congesti-on, it is expedient to provide the cutting edges 4 with chip breaking and/or chip forming edge and face con-tours to facilitate the creation of short and curly chips.
As can be seen especially in Fig. la and 2, the dril-ling tool comprises a feed channel 23 which is adapted to be subjected to pressurized air or a coolant and lu-bricant by way of an opening 25, which feed channel branches off in the region of the tool head 3 and exits to the outside at nozzles 24 at the front end of the tool head 3. The feed channnel 23 communicates with a distributor 26 by way of the nozzle 25 in the region of the suction and scavaging device. In principle it is also possible to lead the feed channnel 23 up to the clamping side end 26 of the drill shank and to sub~ect it there with pressurized air or a coolant and lubri-cant by way of the clamping chuck.
The stepped drill 2'' shown in Fig. 4a comprises a pi-lot drill 31 having a smaller diameter and a main drill 32 having a larger diameter. The pilot drill 31 compri-ses a stepped tool head 3' with corresponding cutting CA 0224~834 1998-08-06 edges 4', while the main drill comprises two cutting edges 4'' in the conical intermediate region 40 (Fig.
4b). The chip grooves 7' and the interposed ribs 8' of the pilot drill 31 directly merge into the helical chip grooves 7'' and the ribs 8'' of the main drill 32 in the intermediate region 40. A slotted sleeve lO' having slot 13' is pushed over the tool head 3' and the coni-cal intermediate region 40 onto the the shank of the pilot drill 31 and of the main drill 32 by spreading apart the sleeve, and is affixed thereto by clamping and/or welding. As can be seen from Fig. 4c, the slot-ted sleeve is fabricated from a blank 10'', which comprises a narrow portion 41 for the pilot drill 31 and a wide portion 42 for the main drill 32, which are joined to each other by an intermediate portion 43. The openings 44 in the intermediate portion 43 are provided for the through-passage o~ the cutting edges ~'' of the main drill 32. The plane blank 10'' is wound around a mandrel geometrically corresponding to the stepped drill, so that the edges 14', 15' delimiting the slot 13' contact each other with their faces. In this state the sleeve 10', which is made of steel sheet metal, is resiliently hardened, so that it may be clamped onto the stepped drill such that the slot edges 14', 15' are supported on the solid material o~ one of the ribs 8' and, if so desired, can be welded thereto.
In summary the following is to be stated: The invention relates to drilling tool for machine tools, comprising CA 0224~834 1998-08-06 a tool head 3 and a tool shank 5 having at least one chip groove. A slotted sleeve 10 is placed onto the tool shank in a tightly encompassing manner wherein the edges 14, 15 delimiting the slot 13 rest on solid mate-rial of the tool shank 5. The chip grooves 7 and the sleeve 10 form channels for removing chips created at the bottom of a ~ore in a workpiece. Due to the slot 13 the sleeve 10 may be mounted onto the tool shank 5, by a slight spreading apart of the sleeve, from the side of the thickened tool head 3.
In order to avoid this disadvantage it is known (DE-A-40 33 877) in a drilling tool of the type described above to provide the tool shank with a close-fitting sleeve which extends from the tool head in the direc-tion of the clamped end. The chip grooves and the inner wall of the sleeve thereby delimit channels through which the chips created ln the drilllng process are re-moved. Since the tool head radially protrudes over the circumference of the tool shank and therefore has a larger diameter than the inner diameter o~ the sleeve, in the known drilling tool the sleeve can only be mounted on the tool shank from the clamping end. In drills having a reinforced shank and in stepped drills the fitting of such a sleeve is not possible at all.
Based on this it is the object of the invention to de-velop a drilling tool and a method of productlon thereof, with which closed channels for removing chips can be provided for di~ferent types of drilling tools.
i CA 0224~834 1998-08-06 For the solution of this object the combinations of features of claims 1, 20, 24, 26, 27, and 29 are sug-gested.
The solution according to the invention is based on the idea that the sleeve and/or the tool are designed such that the sleeve can be mounted on the tool shank from the side of the drill tip, in spite of the tool head having a larger diameter than the tool shank.
In order to achieve this it is proposed according to a first variant of the invention that the sleeve has a slot extending over the entirety of its length. The slot makes it possible to spread the sleeve apart so far during mounting that it may be pushed over the thickened tool head and fastened thereto in a tightly fitting manner. The sleeve therefore expediently con-sists of a resilient material, preferably of a spring steel. In order to ensure a secure positioning, it is of advantage when the sleeve lies against the tool shank with its edges which delimit the slot in a sur-face region away from the at least one chip groove. In the case of a helical drill these edges rest on the raised helix turns between the sunk chip grooves.
The slotted sleeve may be clamped onto the tool shank in a friction-fitting manner and/or be affixed to the tool shank in an integral manner by soldering, glueing or welding. In the latter case the sleeve ads to the CA 0224~834 1998-08-06 torsional and flexural stability of the tool as a load carrying member.
In order to prevent an axial movement of the sleeve on the tool shank, the tool head has an axial shoulder acting as a stop for the sleeve, which shoulder is ori-ented in the direction of chip flow. The sleeve may ad-ditionally be connected to the tool shank in a circum-ferential direction in a form-fitting manner. To this end, it expediently comprises at its one end at least one projection which engages a corresponding recess of the stop shoulder. The drilling tool may also be clam-ped such that the sleeve is retained by the tool hol-der, usually a chuck, on the machine side.
When the drilling tool is formed to be a stepped drill, the tool shank of which has at least two shank sections of different diamter with continuous chip grooves, wherein at least one further cutting edge is arranged in the stepped region between the two shank sections, the sleeve may extend over at least one of the shank sections. In order to obtain a closed chip channel, the sleeve is comprised of at least two cylindrical sleeve sections having different diameters, though, which are disposed at an axial distance from one another and which are connected to each other by means of webs which extend over the chip grooves in the stepped regi-on between two shank sections.
CA 0224~834 1998-08-06 A further preferred embodiment of the invention provi-des that the slot of the sleeve is subsequently closed off by addition of material, for instance during the soldering or welding to the tool shank.
With the drilling tool according to the invention the chips stemming from the bottom of the bore can be pus-hed out through the chip channel by the pressure of following chips. The drilling tool according to the in-vention is preferably used in conjunction with a sucti-on device, though, which is either integrated into the tool holder on the machine side or mounted therein.
An advantageous or alternative embodiment of the inven-tion provides that the tool head is adapted to be remo-ved from the tool shank for mounting or exchanging the sleeve. In this case mounting a sleeve which is not slotted from the side of the tip is possible.
A further advantageous or alternative embodiment of the invention therefore provides that the tool shank, toge-ther with the sleeve (10), is adapted to be mounted in the region of its clamping-side end in a suction device on the machine side. By this it is achieved that the chip channel merges into a chip removal conduit of the suction device.
In order to improve the chip removal it is proposed ac-cording to an advantageous embodiment of the invention CA 0224~834 1998-08-06 that the tool shank comprises at least one supply chan-nel for pressurized air and/or a coolant and lubricant, which channel extends up to the tool head and communi-cates thereat in the region of the cutting edge with the chip channel. The pressurized air or the coolant and lubricant is then led through the chip channel to the suction device together with the chips. The pressu-rized air or the coolant and lubricant is supplied eit-her by way of the suction device or centrally by way of a spindle of the machine tool. The chip removal is also made easier when the at least one chip groove has a partial-circular cross section which is complemented by the sleeve to form an essentially circular chip chan-nel.
For the manufacturing of the drilling tool a number of possibilities exist. A first variant of the method con-sists in that a blank of unhardened sheet metal corre-sponding to a development of the sleeve is wound onto a mandrel geometrically corresponding to the tool shank under formation of the slotted sleeve and is resilient-ly hardened, and that the sleeve prepared in this man-ner is pushed over the tool head under widening of the slot and clamped onto the tool shank.
According to a second variant of the method a sheet me-tal is formed in a non-cutting manner over a die or mandrel geometrically corresponding to the tool shank under formation of the sleeve, and the sleeve thus for-CA 0224~834 1998-08-06 med is mounted on the tool shank. In this, the sheet metal is preferably either deep-drawn or extruded.
A third method provides that a pasty, hard metal-containing substance is injected into an injection mould corresponding to the sleeve, and that the sleeve thus formed is then sintered and mounted on the tool shank.
In the two latter variants of the method the sleeve is expediently cut open under formation of the slot and is preferably resiliently hardened, so that the sleeve thus formed may be pushed over the tool head under wi-dening of the slot and clamped onto the tool shank.
In order to improve the glide properties of the sleeve sur~a~e, the sleeve can be surface coated with a pasty hard metal material and heated to cure the coating.
In all variants of the method the sleeve can be inte-grally connected to the tool shank, for example by glu-eing, soldering or welding.
In the following the invention is further described with reference to embodiments schematically shown in the drawing, in which:
~ CA 0224~834 1998-08-06 Fig. la shows a partially cut view of a drilling tool having a glotted sleeve disposed on the tool shank;
Fig. lb shows a development of the slotted sleeve ac-cording to Fig. 1;
Fig. 2 shows a longitudianl section through the dril-ling tool of Fig. 1 in the region of the tool head;
Fig. 3 shows a side view of the drilling tool, which is clamped into a machine tool and connected to a suction and scavaging device;
Fig. 4a shows a side view of a stepped drill with a slotted sleeve;
Fig. 4b shows a side view of the stepped drill of Fig.
4a with the sleeve removed;
Fig. 4c shows a development of the slotted sleeve ac-cording to Fig. 4a.
The drilling tool shown in Fig. 1 and 2has as a core a helical drill 2 which comprises a drill head 3 with two angled cutting edges 4 as well as a tool shank 5 follo-wing the tool head 3. The tool shank 5 comprises two helical chip grooves 7 and ribs 8 disposed inbetween ~ CA 0224~834 1998-08-06 _ g _ the chip grooves 7, which extend ovewr a part of the tool shank from the tool head 3 in the direction of chip flow. The driiling tool 1 can be clamped in the chuck of a machine tool at its groove-free shank end 6.
The tool head 3 has an outer diameter D that is slight-ly larger than the outer diameter d o~ the tool shank 5, so that a step or shoulder 9 is formed between the tool head 3 and the tool shank 5.
A slotted sleeve 10 is disposed on the tool shank 5.
The sleeve 10 is connected to the tool shank 5 in a form- and friction-fitting manner and, if needed, also an integral manner. It is supported with its edge 16 on the shoulder 9 of the tool head 3 and terminates with its opposing edge 18 just before a run-out 11 of the chip grooves 7 which is directed toward the clamping end 6 o~ the tool shank 5. The sleeve 10 has at most the same outer diameter D as the drill head 3, but may also have a slightly smaller diameter.
The sleeve 10 is expediently fabricated ~rom a steel sheet metal blank 12 (Fig. 2) consisting o~ resilient material, wherein the development o~ the sleeve accor-ding to Fig. lb results in a slanted parallelogram. For purposes of orientation the longitudinal axis A of the drilling tool is shown in Fig. lb. The angles o~ the sides 14, 15 o~ the sheet metal blank 12 with respect to the axis A correspond to the angle of ascent o~ the ~ CA 0224~834 1998-08-06 helical rib 8. For the production of the sleeve 10 the sheet metal blank 12 is rolled over a mandrel, so that narrow slot 13 results, which is delimited by the edges 14, 15 of the sheet metal blank 12. The sleeve 10 is positioned on the tool shank 5 in such a manner that the slot 13 runs parallel to one of the ribs 8, wherein the edges 14, 15 delimiting the slot 13 rest on the rib 8.
The sleeve 10 has at its lower edge 16 two projections 16', which engage corrsponding recesses 17 in the shoulder 9 in a form-fitting manner and which thereby hold the sleeve on the tool shank in a non-rotational manner. For a further improvement in this respect the sleeve 10 can be welded to the tool shank 5 with its edges 14 and 15.
As shown in Fig. 3, the drilling tool l can be clamped in a chuck 21 of a machine tool. In the embodiment shown in the figure, there is additionally provided a suction and scavaging device 22 on the machine, into which the drilling tool 1 together with the sleeve 10 may be clamped. During drilling, the cutting edges 4 remove chips from the bottom of a bore in a workpiece (not shown), which chips are continuously suctioned off in the direction of the arrows 27 by way of the chip grooves 7, when the suction device 22 is switched on.
The sleeve lO prevents that the chips contact the bore - CA 0224~834 1998-08-06 wall of the workpiece and thereby degrade the quality of the bore.
In order to ensure a dependable removal of the chips through the chip channels formed between the chip groo-ves 7 and the sleeve 10 without the danger of congesti-on, it is expedient to provide the cutting edges 4 with chip breaking and/or chip forming edge and face con-tours to facilitate the creation of short and curly chips.
As can be seen especially in Fig. la and 2, the dril-ling tool comprises a feed channel 23 which is adapted to be subjected to pressurized air or a coolant and lu-bricant by way of an opening 25, which feed channel branches off in the region of the tool head 3 and exits to the outside at nozzles 24 at the front end of the tool head 3. The feed channnel 23 communicates with a distributor 26 by way of the nozzle 25 in the region of the suction and scavaging device. In principle it is also possible to lead the feed channnel 23 up to the clamping side end 26 of the drill shank and to sub~ect it there with pressurized air or a coolant and lubri-cant by way of the clamping chuck.
The stepped drill 2'' shown in Fig. 4a comprises a pi-lot drill 31 having a smaller diameter and a main drill 32 having a larger diameter. The pilot drill 31 compri-ses a stepped tool head 3' with corresponding cutting CA 0224~834 1998-08-06 edges 4', while the main drill comprises two cutting edges 4'' in the conical intermediate region 40 (Fig.
4b). The chip grooves 7' and the interposed ribs 8' of the pilot drill 31 directly merge into the helical chip grooves 7'' and the ribs 8'' of the main drill 32 in the intermediate region 40. A slotted sleeve lO' having slot 13' is pushed over the tool head 3' and the coni-cal intermediate region 40 onto the the shank of the pilot drill 31 and of the main drill 32 by spreading apart the sleeve, and is affixed thereto by clamping and/or welding. As can be seen from Fig. 4c, the slot-ted sleeve is fabricated from a blank 10'', which comprises a narrow portion 41 for the pilot drill 31 and a wide portion 42 for the main drill 32, which are joined to each other by an intermediate portion 43. The openings 44 in the intermediate portion 43 are provided for the through-passage o~ the cutting edges ~'' of the main drill 32. The plane blank 10'' is wound around a mandrel geometrically corresponding to the stepped drill, so that the edges 14', 15' delimiting the slot 13' contact each other with their faces. In this state the sleeve 10', which is made of steel sheet metal, is resiliently hardened, so that it may be clamped onto the stepped drill such that the slot edges 14', 15' are supported on the solid material o~ one of the ribs 8' and, if so desired, can be welded thereto.
In summary the following is to be stated: The invention relates to drilling tool for machine tools, comprising CA 0224~834 1998-08-06 a tool head 3 and a tool shank 5 having at least one chip groove. A slotted sleeve 10 is placed onto the tool shank in a tightly encompassing manner wherein the edges 14, 15 delimiting the slot 13 rest on solid mate-rial of the tool shank 5. The chip grooves 7 and the sleeve 10 form channels for removing chips created at the bottom of a ~ore in a workpiece. Due to the slot 13 the sleeve 10 may be mounted onto the tool shank 5, by a slight spreading apart of the sleeve, from the side of the thickened tool head 3.
Claims (32)
1. A drilling tool for machine tools, comprising a tool head (3, 3') having at least one cutting edge (4, 4'), a tool shank (5) joining the tool head (3, 3') and being adapted to be clamped in a tool holder (21) of the machine tool with an end (6) opposed to the tool head, at least one straight or helical chip groove (7) formed into the surface of the shank and extending from the tool head (3, 3') in the direction of chip flow along at least part of the length of the shank, and a sleeve (10, 10') encompassing the tool shank (5) and thereby covering the chip groove (7) at least over a part of its length under formation of a closed chip channel, characterized in that the sleeve (10, 10') has a slot (13, 13') extending over the entirety of its length.
2. The drilling tool of claim 1, characterized in that the sleeve (10) lies against the tool shank (5) with its edges (14, 15) which delimit the slot (13) in a surface region (ribs 8) away from the at least one chip groove (7).
3. The drilling tool of claim 1 or 2, characterized in that the sleeve (10) is adapted to be elastically spread apart, increasing its diameter and broadening the slot (13).
4. The drilling tool of one of claims 1 to 3, characterized in that the sleeve (10) consists of a resilient material, preferably of spring steel.
5. The drilling tool of one of claims 1 to 3, characterized in that the sleeve (10) consists of a sintered material.
6. The drilling tool of one of claims 1 to 5, characterized in that the tool head (3, 3') has a larger outer diameter than the tool shank (D > d).
7. The drilling tool of one of claims 1 to 6, characterized in that the tool head (3, 3') has a stop shoulder (9) for the sleeve (10, 10'), which is oriented in the direction of chip flow.
8. The drilling tool of one of claims 1 to 7, characterized in that the cutting edge has a rotary diameter which is larger than the outer diameter of the sleeve (10, 10').
9. The drilling tool of one of claims 1 to 8, characterized in that the sleeve (10) is affixed to the tool shank (5) in a form-fitting and/or friction-fitting and/or integral manner.
10. The drilling tool of one of claims 1 to 9, characterized in that the sleeve (10, 10') is soldered, glued, or welded to the tool shank (5) at least in the region of the slot (13, 13').
11. The drilling tool of one of claims 1 to 10, characterized in that the slot (13, 13') is helically shaped.
12. The drilling tool of one of claims 1 to 11, characterized in that the slot (13, 13') is closed by application of material.
13. The drilling tool of one of claims 1 to 12, characterized in that the sleeve (10, 10') has on its inner and/or outer surface a coating of preferably hard metal.
14. The drilling tool of one of claims 1 to 13, characterized in that the sleeve (10, 10') is connected to the tool shank (5) in a circumferential direction in a form-fitting manner.
15. The drilling tool of claim 14, characterized in that the sleeve (10) comprises at its one end at least one projection (16') which engages a corresponding recess (17) of the stop shoulder (9).
16. The drilling tool of one of claims 1 to 15, characterized in that the tool shank (5) comprises at least two shank sections (31, 32) having different diameters and continuous chip grooves (7'), that at least one further cutting edge is disposed in a stepped region between the two shank sections (31 32), and that the sleeve (10') extends over at least one of the shank sections (31, 32).
17. The drilling tool of one of claims 1 to 16, characterized in that the sleeve is comprised of at least two cylindrical sleeve sections having different diameters, which are disposed at an axial distance from one another.
18. The drilling tool of claim 17, characterized in that the sleeve sections are connected to each other by means of webs which extend over the chip grooves (7') in the stepped region between two shank sections (31, 32).
19. The drilling tool of one of claims 1 to 18, characterized in that the tool shank (5), together with the sleeve (10), is adapted to be mounted in the region of its clamping-side end (6) in a suction device (22) on the machine side.
20. A drilling tool for machine tools, comprising a tool head (3, 3') having at least one cutting edge (4, 4'), a tool shank (5) joining the tool head (3, 3') and being adapted to be clamped in a tool holder (21) of the machine tool with an end (6) opposed to the tool head, at least one straight or helical chip groove (7) formed into the surface of the shank and extending from the tool head (3, 3') in the direction of chip flow along at least part of the length of the shank, and a sleeve (10, 10') encompassing the tool shank (5) and thereby covering the chip groove (7) at least over a part of its length under formation of a closed chip channel, characterized in that the tool shank (5), together with the sleeve (10), is adapted to be mounted in the region of its clamping-side end (6) in a suction device (22) on the machine side.
21. The drilling tool of one of claims 1 to 20, characterized in that the tool shank (5) comprises at least one supply channel for pressurized air and/or a coolant and lubricant, which channel extends up to the tool head (3) and communicates thereat in the region of the cutting edge (4) with the chip channel.
22. The drilling tool of one of claims 1 to 21, characterized in that the at least one chip groove (7) has a partial-circular cross section region.
23. The drilling tool of one of claims 1 to 22, characterized in that the tool head ( 3) is adapted to be removed from the tool shank (5) for mounting or exchanging the sleeve (10).
24. A drilling tool for machine tools, comprising a tool head (3, 3') having at least one cutting edge (4, 4'), a tool shank (5) joining the tool head (3, 3') and being adapted to be clamped in a tool holder (21) of the machine tool with an end (6) opposed to the tool head, at least one straight or helical chip groove (7) formed into the surface of the shank and extending from the tool head (3, 3') in the direction of chip flow along at least part of the length of the shank, and a sleeve (10, 10') encompassing the tool shank (5) and thereby covering the chip groove (7) at least over a part of its length under formation of a closed chip channel, characterized in that the tool head (3) is adapted to be removed from the tool shank (5) for mounting or exchanging the sleeve (10).
25. The drilling tool of one of claims 1 to 24, characterized in that the at least one cutting edge (4, 4', 4'') comprises a chip breaking and/or chip forming edge and/or chip flank contour for creating short and/or curled chips which fit through the at least one chip channel.
26. A method for manufacturing a drilling tool of one of claims 1 to 25, characterized in that a blank of unhardened sheet metal corresponding to a development of the sleeve (10) is wound onto a mandrel geometrically corresponding to the tool shank (7) under formation of the slotted sleeve (10) and is resiliently hardened, and that the sleeve (10) prepared in this manner is pushed over the tool head (3) under widening of the slot (13) and clamped onto the tool shank (5).
27. A method for manufacturing a drilling tool of one of claims 1 to 25, characterized in that a sheet metal is formed in a non-cutting manner over a die or mandrel geometrically corresponding to the tool shank under formation of the sleeve, and that the sleeve (10) thus formed and being provided with a slot is mounted on the tool shank (5).
28. The method of claim 27, characterized in that the sheet metal is deep-drawn or extruded.
29. A method for manufacturing a drilling tool of one of claims 1 to 25, characterized in that a pasty, hard metal-containing substance is injected into an injection mould corresponding to the sleeve (10), and that the sleeve thus formed and being provided with a slot is then sintered and mounted on the tool shank.
30. The method of one of claims 27 to 29, characterized in that the sleeve (10) is cut open under formation of the slot (13) and is preferably resiliently hardened, and that the sleeve (10) thus formed is pushed over the tool head (3) under widening of the slot and clamped onto the tool shank (5).
31. The method of one of claims 26 to 30, characterized in that the sleeve (10) is surface coated with a pasty hard metal material and heated to cure the coating.
32. The method of one of claims 26 to 31, characterized in that the sleeve (10) is glued, soldered or welded to the tool shank.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19612104.3 | 1996-03-27 | ||
| DE19612104A DE19612104A1 (en) | 1996-03-27 | 1996-03-27 | Drilling tool for machine tools and method for its production |
| PCT/EP1997/000806 WO1997035681A1 (en) | 1996-03-27 | 1997-02-20 | Drilling tool for machine tools and method of producing the same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2245834A1 true CA2245834A1 (en) | 1997-10-02 |
Family
ID=29421559
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2245834 Abandoned CA2245834A1 (en) | 1996-03-27 | 1997-02-20 | Drilling tool for machine tools and method of producing the same |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2245834A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107225269A (en) * | 2017-06-12 | 2017-10-03 | 杭州希恩希拓斯精密机械有限公司 | With the top cutter of evagination |
-
1997
- 1997-02-20 CA CA 2245834 patent/CA2245834A1/en not_active Abandoned
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107225269A (en) * | 2017-06-12 | 2017-10-03 | 杭州希恩希拓斯精密机械有限公司 | With the top cutter of evagination |
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| FZDE | Dead |