CA1278710C - Hard-metal twist drill with internal cooling channels - Google Patents
Hard-metal twist drill with internal cooling channelsInfo
- Publication number
- CA1278710C CA1278710C CA000534233A CA534233A CA1278710C CA 1278710 C CA1278710 C CA 1278710C CA 000534233 A CA000534233 A CA 000534233A CA 534233 A CA534233 A CA 534233A CA 1278710 C CA1278710 C CA 1278710C
- Authority
- CA
- Canada
- Prior art keywords
- shank
- section
- twist drill
- cutter section
- recess
- 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.)
- Expired - Fee Related
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23B—TURNING; BORING
- B23B51/00—Tools for drilling machines
- B23B51/06—Drills with lubricating or cooling equipment
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Drilling Tools (AREA)
- Drilling And Boring (AREA)
Abstract
ABSTRACT
A twist drill with internal cooling channels comprises a shank and a cutter section. The cutter section, is entirely of hard metal, and has at least two helical flutes forming a cut chip space. The flutes extend the entire length of the cutter section, the face of the end section remote from the drill cutting tip being connected to a face surface formed on the forward end section of the shank. The cooling channels in the cutter section and the shank are sealed from the chip space by soldered mutually matching surfaces between the cutter section and the shank.
A twist drill with internal cooling channels comprises a shank and a cutter section. The cutter section, is entirely of hard metal, and has at least two helical flutes forming a cut chip space. The flutes extend the entire length of the cutter section, the face of the end section remote from the drill cutting tip being connected to a face surface formed on the forward end section of the shank. The cooling channels in the cutter section and the shank are sealed from the chip space by soldered mutually matching surfaces between the cutter section and the shank.
Description
~787~
The present invention relates to a helical twist drill havin~
internal cooling channels.
Twist drills of thi~ type, made of high-speed steel, are already known, and achieve high cutting speeds. In such high-speed steel units, the shank and the cutter section can be made in one piece, even though this can re6ult in production difficulties since the shanX and the cutter section require different trsatment. When made from a combined shank and socket, with a hard-metal cutter tip attached to the socket, there can be difficulties in connecting the cooling channels formed within the carrier tip to the shank or socket section. In this latter structure, the possibilities for reBrinding are greatly restricted.
It is an object of the present invention to produce high-performance twist drills which can be made very simply but nevertheless deliver greatly increased cutting performance.
The concept of a twist drill embodying the present invention permits its production from two separately manufactured parts, namely, a cutter section having uninterrupted flutes extending its entire length, and the shank. A cylindrical section of material of any length can thus be fluted, so that, either subsequently or even during the fluting process, it can be divided into smaller sections of desired length. When the shank and the cutter section are assembled it is possible to achieve reliable sealing of the cooling channels agalnst leakage into the chip space by comparatively simple means at the matching surfaces between the cutter section and the shank.
Since the transmission of torque from the ghank to the cutter section can take place in such a twlst drill where the receg~ in the ghank matches the outer surface of the cutter section preferably throu~h the outer surfaces of the drill lands, which are soldered to the inner surfaces of the shank, there is no significant extra expenditure involved in production. In ad~ition, during soldering to the ed8es of the drill lands, a resultant bead of soldering material pro~ects sli8htly into the grooves, and further improves the torque transmission. At the end of the service life of the cutter section, it can simply be removed from the shank at minimum expense, and the shank can be reused. Longer overall service life of the twist drill results from the fact that, the cutter section can be repeatedly reground right up to the place where it enters the shank.
PAT 10757~
1'~787~0 Assembly and dismantling of the twist drill are greatly simplified with the sbank being cylindrical and conforming to the outside diameter of the cutter section. It has been shown that soldering at the outer surfaces of the drill lands is quite sufficient to transmit even the highest torques encountered, provided that the dimensions of the matching surfaces are properly selected.
A Dy a ~ 6 the coolant channel in the shank to the channels in the cutter section with direct face contact at the bottom of the recess prevents leakage into the spaces formed by the flutes.
When the contact surface between cutter section and shank ls formed by the bottom of the recess, it is simpler to connect the cooling channels in the cutter section with that in the shank.
The arrangement of a cooling channel transition element, between the shank and the cutter section makes it possible to dispense with any special measures in the shank or cutter section, it being possible to configure the cooling channels formed in the individual parts independently of each other.
The face surfaces of the cutter section arranged in the recess can be provided with a radial transverse channel which connects the opening surfaces of the cooling channel w~th each other to simplify connection of the cooling channels in the cutter sectlon wlth those of the coollng channel transltion element of the shank, respectlvely.
As an alternat~ve to this, it can be expedlent to slot the channel transition element, and use it for purposes of sealing and force transmlsslon.
The installation of adhesive between the shank and the cutter 6ection, in the area of the opening of the recegs, increase~ the bond between the cutter section snd the shank, and prevents any chips enterin8 the recess.
When the recess 18 conflgured witb a helical internal thread section a substantially continuous, even flow of the load from the shank into the cutter sectlon is possible. ~his effect i8 enhanced if the thread extends axially the whole length of the recess.
A shaped plate closing off the opening to the recess permits the transmission of force by form fit, without the need for any special shaping of the recess in the shank. Depending on the type and manner of production, the plate can be produced in one piece with the shank, or can be produced separately and fixed rigidly to the shank.
PA~ 10757-1 1',~787~0 A configuration where the peripheries of the cutter section and shank are shape locking, permits a considerable reduction in the surface required for the transmission of torque, this surface being enlarged only slightly by the configuration of the slot recess or the connector channel sections to connect the cooling channels in the cutter section to the shank, respectively.
Where the shank or its section forming the recess is cast, the recess and in particular the elements within it effecting the transmission of forces, can be produced simply and with a high degree of precision.
More particularly in accordance with the invention there is provided, a twist drill having internal cooling channels, comprising a shank and a cutter section, and having at least two helical flutes forming a chip space, characterized in that the cutter section is entirely of hard metal, has flutes which extend its whole length, and is connected with its end section remote from the tip of the drill to the shank by face surfaces formed on it and on the forward end section of the shank, said end section being inserted into a matching recess in the shank: and, the cooling channels being sealed off from the chip space by means of soldered matching surfaces between the cutter section and the shank.
Specific embodiments of the invention will now be described with reference to the accompanying drawings in which:
Figure 1 is a plan view of a twist drill when assembled;
Figure 2 shows the cutter section of the twist drill in side view;
Figure 3 shows the cutter section in cross-section;
Figure 4 is the shank in side axial section:
Figure 5 is a section on line V-V of Figure l;
Figure 6 is an exploded view of a second embodiment of the twist drill:
Figure 7 i9 an axial section oE an embodiment of the shank of the second embodiment of the twist drill;
3Q Figure 8 is an axial section of a further embodiment of the shank of the second embodiment of the twist drill:
Figure 9 is an axial section through the shank, helically grooved, accommodating the adjacent end section of the cutter section:
Figure 10 is a partly sectional view of the connection between the shank and the cutter section of the twist drill Figure 11 is a front view of the cooling channel transition element 12q87~0 shown in Figure 10;
Figure 12 i9 a partly sectional view of another connection similar to that shown in Figure 10;
Figure 13 is a front view of the cooling channel transition element shown in FigurQ 12, Figure 14 is a partly sectional view of yet another connection, similar to that shown in Figure 10;
Figure 15 is a front view, of the cooling channel transition element shown in Figure 14;
Figure 16 is a front view of a radial transverse channel connection in the cutter section;
Figure 17 is a front view of a transverse channel connection in the cutter section confi~ured differently;
Pigure 18 is a partly sectional view of a connection between the cutter section and the shank, both bein8 of the same diameter;
Figure 19 i8 a front view of the shank of a fourth embodlment of the twist drill;
Figure 20 is a section along line A-A of Figure 19, showing in addition the ad~acent end of the cutter section;
Flgure 21 is a section along line B-B of Fl~ure 20;
Figure 22 is a front view of the shank portion of a fifth embodiment of the twist drlll;
Figure 23 i0 a sectlon along line A~A of Pigure 22, additionslly showing the ad~acent end of the cutter section;
Fi~ure 24 is an exploded view Oe the transitlon zone of the twist drill of Figures 22 and 23;
Figure 25 i8 an exploded vlew of the transition zone of the twist drill, in which two connector channel ~ections sre provided.
The twist drill 10 shown in Pigures 1 to 4 is divided essentially ~0 into two sections, the cutter section 12 and the shank 14.
The cutter section 12 is entirely of hard metal and, in the embodiment ~hown, has two flutes 16, 18 on the outside surface of the cutter section 12 staggered by 180 degrees relative to one another and which constitute a chip space through which the shavings are removed from the bottom of the drilled hole.
78~7~LO
The flute~ 16, 18 are definea by two drill webs 20, 22 within each of which there i8 a cooling channel 38, 40 set radially outwards from the axis of the bit. The outer surfaces of the drill webs 20, 22 have lands, by which the cutter section 12 of the twist drill 10 is guided or centered, within a drilled hole. The shank 14 serves to transmit the forces to the cutter section 12 being connected by a slip-free coupling to the output shaft of the drill motor.
To connect to the cutter section 12, the shank 14 is provided, as ~hown in Figure 4, with a recess 24, the inside diameter of which is approximately the ssme as the outside diameter of the cutter section 12.
Within the area of the opening surface of the recess 24 the outside surface of the cutter section 12 is connected to the inner wall of the recess 24 within the shank 14, as is shown in Figure S. The lands are soldered to the inner wall of the recess 24 and adhesive 19 is placed in the flutes close to the opening surface. The adhesive bond formed is intended to last throughout the service life of the twist drill 10 and serves to fill the cavity formed by the flutes 16, 18 in the area of the opening surface, to prevent the ingress of chips into recess 24 within shank 14.
In a further embodiment, shown in Fi~ure 6, the outer end of the reces6 24 is closed by a plate 26. The plate 26 forms an opening, whose cross-section matches that of the cutter section 12. The end of the cutter section 12 remote from the tip of the drill ia slid axially through the plate opening 26 and lnto the reces~ 24, by giving it a rotary motion requlred by the form fit, until lts tip reqts against the bottom of the recess 24. In this embodiment, torque for th0 drill is tran~mltted essentially from the shanX 14 by m0ans of the shape and force lockin6 fit betwe0n the plate 26 ~connectQd rigidly with the ~hank 14) and the cutter s~ction 12. The soldered joint between the correspondlng mstching surfaces in the bottom of the recess 24 which have atill to be described, prevents cooling medium escaping into the chip space. The chemical resistance of this goldered connection must be sufficient to prevent corrosive action by the cooling medium throughout the service life of the cutter section 12.
Instead of the arrangement shown in Figure 7, in which the plate 26 is shown as a separate element fixed rigidly to it, the shank 14 can be formed in one piece with an annular projection 28, the cross~section of which matches lZ787~0 the plate 26 overall and which projects radially inwards, as is shown in longitudinal section in Figure 8.
Figure 9 shows the shank 14 of the twist drill 10, which has an internally threaded section 15 configured to correspond to the shape of the cutter section, the overall axial overlapping length between the cutter section 12 and the shanX 14 being usable for transmission of working loads.
Figureæ 10 to lS show embodiments of the connection between the cooling channels 38, 40 of the cutter section 12 to the cooling channel 44 of the shank 14 and for sealing the connection. Between the face side of the cutter section remote from the drill tip and the bottom of the recess 24 in the shank 14 there is in each instance a cooling channel transition element 28, 30, 32. This element is connected to both the shank 14 and to the cutter section 12 80 as to be leakproof. There is thus no need for additional measures to ensure a seal between the cooling channels and the chip space.
Since the connecting surfaces between the shank 14 and the cutter section 12, which serve to transmit the forces encountered, are not exposed to the cooling medium, they can be made more cheaply, or in certain circumstances, be dispensed with when torque being transmitted by shape or force locking.
The coolin~ channel transltion element 28 shown in Figures 10 and 11 Z0 has two separate cooling channel sectlons 34, 36; these are parallel and extend in the axial direction of the drill 10, thereby connecting the cooling channels 38, 40 of the cutter sectlon 12 separately, with a wider sectlon 42 of the end of the cooling channel 44 in the shank 14.
The cooling chsnnel transition element 30 ~hown in Figures 12 and 13 has two mutually inclined cooling channel gectlong 46 and 48; each runs from a common connectlon 50 in the cooling channel 44 of the shank 14 to a respectlve end opening of the cooling channels 38, 40 o the cutter sectlon 12.
Fi~ures 14 and lS show a cooling channel transitlon element 32 w~th a slot 49, through which the whole centre section of the face end of the cutter section 12 located within the recess 24, and thus the two open end surface of the cooling channels 38, 40 of the cutter section 12 are connected to the cooling channel 44 in the shank 14.
Where the cooling channel transition element has only one opening, which does not cover both the openings of the cooling channels 38, 40 formed in the cutter section 12, a groove-like depression 52 is formed in the ~'~7B7~0 corresponding face surface 13 of the cutter section 12 as a transverse channel connection extending across the total diameter of the cutter section 12 or, as in Figure 17, only across its mid-section.
With a cutter section diameter approximately the same as that of the shanX 14, an assembly section 56 is formed in the end section of the cutter section remote from the cutting tip by a radial step or necked-down section, used to join both parts. The outside diameter of this assembly section 56 corresponds to the inside diameter of the recess 24 formed in the shank 14 An embodiment is shown in Figure 18.
The shank 14 shown in Figures 19 to 21 has a face side 13a in the transition section, and this is formed by a hollow-edge recess 14b. The two flat surfaces forming the recess 14b intersect in the middle of a slot 14a which connects the openings forming the cooling channels 38, 40 in the face side 13 of the cutter section 12, with the central cooling channel 44 in the shank 14. The faces 13 and 13a are soldered to one another, which prevents leakage of coolant into the chip space formed by the flutes 16, 18. Effective transmission of the torque is ensured by the ghape locking fit particularly at the periphery of the twist drill where the prism-shaped tip of the end of the cuttsr sectlon 12 enga8es in the reces~ 14b in the shank 14.
Figures 22 to 24 show a twist drill similar to the one described above but, in this instance, the prism-ghaped tip 13 of the cutter section 12 and the hollow wedge recess 14b of the shank 14 are interchanged. The functlons and the effects correspond to those describQd for the embodiment of Figures 19 and 20.
Flgure 25 shows an alternative posslbility for the connectlon for the cooling chsnnels 38, 4Q Oe a twist drill simllar to the one shown in Figures 19 to 24. Here, connecting channel sections 14d and 14e are formed in the transition zone between the shank 14 and the cutter section 12, in place of the slot reces~ 14a. These connect each cooling channel 38, 40 individually with the cooling channel 44 in the shank 14.
The present invention relates to a helical twist drill havin~
internal cooling channels.
Twist drills of thi~ type, made of high-speed steel, are already known, and achieve high cutting speeds. In such high-speed steel units, the shank and the cutter section can be made in one piece, even though this can re6ult in production difficulties since the shanX and the cutter section require different trsatment. When made from a combined shank and socket, with a hard-metal cutter tip attached to the socket, there can be difficulties in connecting the cooling channels formed within the carrier tip to the shank or socket section. In this latter structure, the possibilities for reBrinding are greatly restricted.
It is an object of the present invention to produce high-performance twist drills which can be made very simply but nevertheless deliver greatly increased cutting performance.
The concept of a twist drill embodying the present invention permits its production from two separately manufactured parts, namely, a cutter section having uninterrupted flutes extending its entire length, and the shank. A cylindrical section of material of any length can thus be fluted, so that, either subsequently or even during the fluting process, it can be divided into smaller sections of desired length. When the shank and the cutter section are assembled it is possible to achieve reliable sealing of the cooling channels agalnst leakage into the chip space by comparatively simple means at the matching surfaces between the cutter section and the shank.
Since the transmission of torque from the ghank to the cutter section can take place in such a twlst drill where the receg~ in the ghank matches the outer surface of the cutter section preferably throu~h the outer surfaces of the drill lands, which are soldered to the inner surfaces of the shank, there is no significant extra expenditure involved in production. In ad~ition, during soldering to the ed8es of the drill lands, a resultant bead of soldering material pro~ects sli8htly into the grooves, and further improves the torque transmission. At the end of the service life of the cutter section, it can simply be removed from the shank at minimum expense, and the shank can be reused. Longer overall service life of the twist drill results from the fact that, the cutter section can be repeatedly reground right up to the place where it enters the shank.
PAT 10757~
1'~787~0 Assembly and dismantling of the twist drill are greatly simplified with the sbank being cylindrical and conforming to the outside diameter of the cutter section. It has been shown that soldering at the outer surfaces of the drill lands is quite sufficient to transmit even the highest torques encountered, provided that the dimensions of the matching surfaces are properly selected.
A Dy a ~ 6 the coolant channel in the shank to the channels in the cutter section with direct face contact at the bottom of the recess prevents leakage into the spaces formed by the flutes.
When the contact surface between cutter section and shank ls formed by the bottom of the recess, it is simpler to connect the cooling channels in the cutter section with that in the shank.
The arrangement of a cooling channel transition element, between the shank and the cutter section makes it possible to dispense with any special measures in the shank or cutter section, it being possible to configure the cooling channels formed in the individual parts independently of each other.
The face surfaces of the cutter section arranged in the recess can be provided with a radial transverse channel which connects the opening surfaces of the cooling channel w~th each other to simplify connection of the cooling channels in the cutter sectlon wlth those of the coollng channel transltion element of the shank, respectlvely.
As an alternat~ve to this, it can be expedlent to slot the channel transition element, and use it for purposes of sealing and force transmlsslon.
The installation of adhesive between the shank and the cutter 6ection, in the area of the opening of the recegs, increase~ the bond between the cutter section snd the shank, and prevents any chips enterin8 the recess.
When the recess 18 conflgured witb a helical internal thread section a substantially continuous, even flow of the load from the shank into the cutter sectlon is possible. ~his effect i8 enhanced if the thread extends axially the whole length of the recess.
A shaped plate closing off the opening to the recess permits the transmission of force by form fit, without the need for any special shaping of the recess in the shank. Depending on the type and manner of production, the plate can be produced in one piece with the shank, or can be produced separately and fixed rigidly to the shank.
PA~ 10757-1 1',~787~0 A configuration where the peripheries of the cutter section and shank are shape locking, permits a considerable reduction in the surface required for the transmission of torque, this surface being enlarged only slightly by the configuration of the slot recess or the connector channel sections to connect the cooling channels in the cutter section to the shank, respectively.
Where the shank or its section forming the recess is cast, the recess and in particular the elements within it effecting the transmission of forces, can be produced simply and with a high degree of precision.
More particularly in accordance with the invention there is provided, a twist drill having internal cooling channels, comprising a shank and a cutter section, and having at least two helical flutes forming a chip space, characterized in that the cutter section is entirely of hard metal, has flutes which extend its whole length, and is connected with its end section remote from the tip of the drill to the shank by face surfaces formed on it and on the forward end section of the shank, said end section being inserted into a matching recess in the shank: and, the cooling channels being sealed off from the chip space by means of soldered matching surfaces between the cutter section and the shank.
Specific embodiments of the invention will now be described with reference to the accompanying drawings in which:
Figure 1 is a plan view of a twist drill when assembled;
Figure 2 shows the cutter section of the twist drill in side view;
Figure 3 shows the cutter section in cross-section;
Figure 4 is the shank in side axial section:
Figure 5 is a section on line V-V of Figure l;
Figure 6 is an exploded view of a second embodiment of the twist drill:
Figure 7 i9 an axial section oE an embodiment of the shank of the second embodiment of the twist drill;
3Q Figure 8 is an axial section of a further embodiment of the shank of the second embodiment of the twist drill:
Figure 9 is an axial section through the shank, helically grooved, accommodating the adjacent end section of the cutter section:
Figure 10 is a partly sectional view of the connection between the shank and the cutter section of the twist drill Figure 11 is a front view of the cooling channel transition element 12q87~0 shown in Figure 10;
Figure 12 i9 a partly sectional view of another connection similar to that shown in Figure 10;
Figure 13 is a front view of the cooling channel transition element shown in FigurQ 12, Figure 14 is a partly sectional view of yet another connection, similar to that shown in Figure 10;
Figure 15 is a front view, of the cooling channel transition element shown in Figure 14;
Figure 16 is a front view of a radial transverse channel connection in the cutter section;
Figure 17 is a front view of a transverse channel connection in the cutter section confi~ured differently;
Pigure 18 is a partly sectional view of a connection between the cutter section and the shank, both bein8 of the same diameter;
Figure 19 i8 a front view of the shank of a fourth embodlment of the twist drill;
Figure 20 is a section along line A-A of Figure 19, showing in addition the ad~acent end of the cutter section;
Flgure 21 is a section along line B-B of Fl~ure 20;
Figure 22 is a front view of the shank portion of a fifth embodiment of the twist drlll;
Figure 23 i0 a sectlon along line A~A of Pigure 22, additionslly showing the ad~acent end of the cutter section;
Fi~ure 24 is an exploded view Oe the transitlon zone of the twist drill of Figures 22 and 23;
Figure 25 i8 an exploded vlew of the transition zone of the twist drill, in which two connector channel ~ections sre provided.
The twist drill 10 shown in Pigures 1 to 4 is divided essentially ~0 into two sections, the cutter section 12 and the shank 14.
The cutter section 12 is entirely of hard metal and, in the embodiment ~hown, has two flutes 16, 18 on the outside surface of the cutter section 12 staggered by 180 degrees relative to one another and which constitute a chip space through which the shavings are removed from the bottom of the drilled hole.
78~7~LO
The flute~ 16, 18 are definea by two drill webs 20, 22 within each of which there i8 a cooling channel 38, 40 set radially outwards from the axis of the bit. The outer surfaces of the drill webs 20, 22 have lands, by which the cutter section 12 of the twist drill 10 is guided or centered, within a drilled hole. The shank 14 serves to transmit the forces to the cutter section 12 being connected by a slip-free coupling to the output shaft of the drill motor.
To connect to the cutter section 12, the shank 14 is provided, as ~hown in Figure 4, with a recess 24, the inside diameter of which is approximately the ssme as the outside diameter of the cutter section 12.
Within the area of the opening surface of the recess 24 the outside surface of the cutter section 12 is connected to the inner wall of the recess 24 within the shank 14, as is shown in Figure S. The lands are soldered to the inner wall of the recess 24 and adhesive 19 is placed in the flutes close to the opening surface. The adhesive bond formed is intended to last throughout the service life of the twist drill 10 and serves to fill the cavity formed by the flutes 16, 18 in the area of the opening surface, to prevent the ingress of chips into recess 24 within shank 14.
In a further embodiment, shown in Fi~ure 6, the outer end of the reces6 24 is closed by a plate 26. The plate 26 forms an opening, whose cross-section matches that of the cutter section 12. The end of the cutter section 12 remote from the tip of the drill ia slid axially through the plate opening 26 and lnto the reces~ 24, by giving it a rotary motion requlred by the form fit, until lts tip reqts against the bottom of the recess 24. In this embodiment, torque for th0 drill is tran~mltted essentially from the shanX 14 by m0ans of the shape and force lockin6 fit betwe0n the plate 26 ~connectQd rigidly with the ~hank 14) and the cutter s~ction 12. The soldered joint between the correspondlng mstching surfaces in the bottom of the recess 24 which have atill to be described, prevents cooling medium escaping into the chip space. The chemical resistance of this goldered connection must be sufficient to prevent corrosive action by the cooling medium throughout the service life of the cutter section 12.
Instead of the arrangement shown in Figure 7, in which the plate 26 is shown as a separate element fixed rigidly to it, the shank 14 can be formed in one piece with an annular projection 28, the cross~section of which matches lZ787~0 the plate 26 overall and which projects radially inwards, as is shown in longitudinal section in Figure 8.
Figure 9 shows the shank 14 of the twist drill 10, which has an internally threaded section 15 configured to correspond to the shape of the cutter section, the overall axial overlapping length between the cutter section 12 and the shanX 14 being usable for transmission of working loads.
Figureæ 10 to lS show embodiments of the connection between the cooling channels 38, 40 of the cutter section 12 to the cooling channel 44 of the shank 14 and for sealing the connection. Between the face side of the cutter section remote from the drill tip and the bottom of the recess 24 in the shank 14 there is in each instance a cooling channel transition element 28, 30, 32. This element is connected to both the shank 14 and to the cutter section 12 80 as to be leakproof. There is thus no need for additional measures to ensure a seal between the cooling channels and the chip space.
Since the connecting surfaces between the shank 14 and the cutter section 12, which serve to transmit the forces encountered, are not exposed to the cooling medium, they can be made more cheaply, or in certain circumstances, be dispensed with when torque being transmitted by shape or force locking.
The coolin~ channel transltion element 28 shown in Figures 10 and 11 Z0 has two separate cooling channel sectlons 34, 36; these are parallel and extend in the axial direction of the drill 10, thereby connecting the cooling channels 38, 40 of the cutter sectlon 12 separately, with a wider sectlon 42 of the end of the cooling channel 44 in the shank 14.
The cooling chsnnel transition element 30 ~hown in Figures 12 and 13 has two mutually inclined cooling channel gectlong 46 and 48; each runs from a common connectlon 50 in the cooling channel 44 of the shank 14 to a respectlve end opening of the cooling channels 38, 40 o the cutter sectlon 12.
Fi~ures 14 and lS show a cooling channel transitlon element 32 w~th a slot 49, through which the whole centre section of the face end of the cutter section 12 located within the recess 24, and thus the two open end surface of the cooling channels 38, 40 of the cutter section 12 are connected to the cooling channel 44 in the shank 14.
Where the cooling channel transition element has only one opening, which does not cover both the openings of the cooling channels 38, 40 formed in the cutter section 12, a groove-like depression 52 is formed in the ~'~7B7~0 corresponding face surface 13 of the cutter section 12 as a transverse channel connection extending across the total diameter of the cutter section 12 or, as in Figure 17, only across its mid-section.
With a cutter section diameter approximately the same as that of the shanX 14, an assembly section 56 is formed in the end section of the cutter section remote from the cutting tip by a radial step or necked-down section, used to join both parts. The outside diameter of this assembly section 56 corresponds to the inside diameter of the recess 24 formed in the shank 14 An embodiment is shown in Figure 18.
The shank 14 shown in Figures 19 to 21 has a face side 13a in the transition section, and this is formed by a hollow-edge recess 14b. The two flat surfaces forming the recess 14b intersect in the middle of a slot 14a which connects the openings forming the cooling channels 38, 40 in the face side 13 of the cutter section 12, with the central cooling channel 44 in the shank 14. The faces 13 and 13a are soldered to one another, which prevents leakage of coolant into the chip space formed by the flutes 16, 18. Effective transmission of the torque is ensured by the ghape locking fit particularly at the periphery of the twist drill where the prism-shaped tip of the end of the cuttsr sectlon 12 enga8es in the reces~ 14b in the shank 14.
Figures 22 to 24 show a twist drill similar to the one described above but, in this instance, the prism-ghaped tip 13 of the cutter section 12 and the hollow wedge recess 14b of the shank 14 are interchanged. The functlons and the effects correspond to those describQd for the embodiment of Figures 19 and 20.
Flgure 25 shows an alternative posslbility for the connectlon for the cooling chsnnels 38, 4Q Oe a twist drill simllar to the one shown in Figures 19 to 24. Here, connecting channel sections 14d and 14e are formed in the transition zone between the shank 14 and the cutter section 12, in place of the slot reces~ 14a. These connect each cooling channel 38, 40 individually with the cooling channel 44 in the shank 14.
Claims (21)
1. A twist drill having internal cooling channels, comprising a shank and a cutter section, and having at least two helical flutes forming a chip space, characterized in that the cutter section (12) is entirely of hard metal, has flutes (16, 18) which extend its whole length, and is connected with its end section remote from the tip of the drill to the shank (14) by face surfaces (13, 13a) formed on it and on the forward end section of the shank said end section being inserted into a matching recess (24) in the shank (14) and the cooling channels (38, 40, 44) being sealed off from the chip space by soldered matching surfaces between the cutter section (12) and the shank (14).
2. A twist drill as in claim 1, characterized in that the recess (24) in the shank (14) is cylindrical and conforms to the outside diameter of the cutter section (12).
3. A twist drill as in claim 1, characterized in that sealing is effected by way of a face surface (13) of the cutter section (12) lying against a correspondingly shaped contact surface at the bottom of the recess (24).
4. A twist drill as in claim 3, characterized in that the shank (14) has a central cooling channel (44), the diameter of which is smaller than the diameter of the cross-section of the cutter section (12) and connects to the two cooling channels (38,40); the contact surface being formed by the bottom of the recess (24).
5. A twist drill as in claim 1, characterized in that the face surface (13) of the cutter section (12) lies against a contact surface of a cooling channel transition element (28, 30, 32) at the bottom of the recess (24) in the shank (14), the cooling channel (44) in the shank (14) directionally branching to respective cooling channels (38, 40) in the cutter section (12).
6. A twist drill as in claim 5, characterized in that the cooling channel openings on the face side (13) of the cutter section (12) are connected singly to corresponding openings of the cooling channel transition element (28, 30, 32).
7. A twist drill as in claim 4 or claims 5, characterized in that the cooling channels (38, 40) in the cutter section (12) are connected by means of a radial transverse channel connection (52) arranged on its face surface (13).
8. A twist drill as in claim 4 or claims 5, characterized in that the cooling channel transition element (32) is a force fit in the recess (24) and has a slot (49) into which the cooling channels (38, 40) of the cutter section (12) open out.
9. A twist drill as in claim 1 characterized in that between the cutter section (12) and the shank (14) adjacent the opening surface of the recess (24) a layer of adhesive fills the flutes (16, 18).
10. A twist drill as in claim 1 characterized in that the recess (24) is configured with a helical internal thread section (15), in which a corresponding section of the cutter section (12) is a force fit.
11. A twist drill as in claim 10, characterized in that the internally threaded section (15) extends axially the whole length of the recess (24).
12. A twist drill according to claim 1 characterized in that the recess (24) is closed off by a plate (26) which, defines the opening to the recess (24), and conforms to the cross-section of the cutter section.
13. A twist drill as in claim 12, characterized in that the plate (26) is formed in one piece with the shank (14).
14. A twist drill as in claim 12, characterized in that the plate (26) is formed separately and is connected rigidly to the shank (14).
15. A twist drill as in claim 1, characterized in that the adjacent face surfaces (13, 13a, respectively) of the cutter section (12) or the shank (14), respectively, are formed as matching surfaces such that their planes intersect; the shank (14) and cutter region (12) being connectable and shape-locking at their peripheries, the cooling channel (44) of the shank (14) being connected by the end section of the shank (14) to the individual cooling channels (38, 40) of the cutter section (12).
16. A twist drill as in claim 15, characterized in that the face surface (13) of the cutter section (12) is prism shaped and projects and fits into a correspondingly shaped recess (14b) in the face (13a) of the shank (14).
17. A twist drill as in claim 15. characterized in that the face (13a) of the shank (14) is prism shaped and projects and fits in a correspondingly shaped recess (13a) in the face surface (13) of the cutter section (12).
18. A twist drill as in claim 15,16 or 17 , characterized in that a slot-like recess (14a) is provided in the end section of the shank (14) to connect the cooling channels (38, 40) of the cutter section (12) to the cooling channel (44) in the shank (14), through which the cooling channel (44) in the shank (14) is widening to the individual cooling channels (38, 40) of the cutter section (12).
19. A twist drill as in claim 15,16 or 17 , characterized in that connection of the cooling channels (38, 40) of the cutter section (12) to the cooling channel (44) in the shank (14), is effected by connector channel sections (14d, 14e) being provided in the end section of the shank (14), each of which runs from the cooling channel (44) to one of the cooling channels (38, 40).
20. A twist drill as in claim 10, 11 or 14 , characterized in that the section of the shank (14) that forms the recess (24) is a cast body.
21. A twist drill as in claim 10,11 or 14, characterized in that the shank (14) is a cast body.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3611998.9 | 1986-04-09 | ||
| DE19863611998 DE3611998A1 (en) | 1986-04-09 | 1986-04-09 | FULL HARD METAL DRILL DRILL WITH INSIDE COOLING CHANNELS |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1278710C true CA1278710C (en) | 1991-01-08 |
Family
ID=6298343
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000534233A Expired - Fee Related CA1278710C (en) | 1986-04-09 | 1987-04-09 | Hard-metal twist drill with internal cooling channels |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0240765A3 (en) |
| KR (2) | KR870009799A (en) |
| BR (1) | BR8701646A (en) |
| CA (1) | CA1278710C (en) |
| DE (1) | DE3611998A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9999932B2 (en) | 2014-04-28 | 2018-06-19 | Hartmetall-Werkzeugfabrik Paul Horn Gmbh | Tool for machining a workpiece |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19835677C5 (en) * | 1998-07-22 | 2010-11-04 | Gühring, Jörg, Dr. | Device for supplying media to a tool |
| US7160067B2 (en) | 2004-07-13 | 2007-01-09 | Ford Motor Company | Tool holder assembly |
| DE102005048635A1 (en) | 2005-10-11 | 2007-04-12 | Kennametal Inc. | Device for feeding coolant into a shaft of a concentricity tool and a concentricity tool, in particular a drill |
| DE102014000994A1 (en) * | 2014-01-29 | 2015-07-30 | Franz Haimer Maschinenbau Kg | Insertable stop for tool holders |
| EP3533545A1 (en) * | 2018-03-01 | 2019-09-04 | AB Sandvik Coromant | Modular cutting tool body and method for manufacturing the same |
| US10773323B2 (en) * | 2018-08-21 | 2020-09-15 | Ford Motor Company | Minimum quantity lubrication thread tap |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1409753A (en) * | 1919-06-03 | 1922-03-14 | John B Moore | Method of making self-lubricating tools |
| US1454452A (en) * | 1920-10-27 | 1923-05-08 | John B Moore | Oil tool |
| DE396906C (en) * | 1922-03-05 | 1924-06-23 | Georg Cambeis | Device for the recovery of broken twist drills |
| US3045513A (en) * | 1960-07-05 | 1962-07-24 | Rudolf W Andreasson | Drill |
| US3073189A (en) * | 1960-09-30 | 1963-01-15 | Stalker Drill Works Ltd | Drills |
| AT279998B (en) * | 1967-05-09 | 1970-03-25 | Rohde & Doerrenberg | Process for manufacturing twist drills or similar tools as well as twist drills manufactured according to the process |
| US3460410A (en) * | 1967-08-07 | 1969-08-12 | Franklin S Briles | Reamer |
| DE2246965A1 (en) * | 1972-09-25 | 1974-04-11 | Hawera Probst Kg Hartmetall | TWIST DRILLS |
| DE3232686A1 (en) * | 1982-09-02 | 1984-03-08 | Hartmetallwerkzeugfabrik Andreas Maier GmbH + Co KG, 7959 Schwendi | ROTATIONAL CUTTING TOOL AND METHOD FOR THE PRODUCTION THEREOF |
| DE3309860A1 (en) * | 1983-02-08 | 1984-08-09 | Fa. Gottlieb Gühring, 7470 Albstadt | DRILLING TOOL |
-
1986
- 1986-04-09 DE DE19863611998 patent/DE3611998A1/en active Granted
-
1987
- 1987-03-12 EP EP87103570A patent/EP0240765A3/en not_active Withdrawn
- 1987-04-07 KR KR870003294A patent/KR870009799A/en not_active Application Discontinuation
- 1987-04-08 BR BR8701646A patent/BR8701646A/en not_active IP Right Cessation
- 1987-04-09 CA CA000534233A patent/CA1278710C/en not_active Expired - Fee Related
- 1987-04-30 KR KR870004259A patent/KR870009800A/en not_active Application Discontinuation
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9999932B2 (en) | 2014-04-28 | 2018-06-19 | Hartmetall-Werkzeugfabrik Paul Horn Gmbh | Tool for machining a workpiece |
Also Published As
| Publication number | Publication date |
|---|---|
| BR8701646A (en) | 1988-01-05 |
| KR870009799A (en) | 1987-11-30 |
| KR870009800A (en) | 1987-11-30 |
| EP0240765A2 (en) | 1987-10-14 |
| DE3611998A1 (en) | 1987-10-15 |
| EP0240765A3 (en) | 1989-06-14 |
| DE3611998C2 (en) | 1990-10-11 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |