FR2498502A1 - DRILLING TOOL WITH REMOVABLE CUTTING PLATES - Google Patents

Abstract

THE DRILLING TOOL OF THE INVENTION INCLUDES AN ESSENTIALLY CYLINDRICAL ROD AND AT LEAST TWO CUTTING PLATES 4 MOUNTED IN A WAY TO BE REPLACED AT THE FRONT HEAD 3 OF THIS ROD, THESE PLATES BEING FOLLOWED BY AT LEAST TWO CHIP CHANNELS IN A SPIRAL EXTENDING TOWARD A REAR CLAMP 2 OF THE ROD AND OPEN TOWARDS THE EXTERIOR TOWARDS THE PERIPHERAL SURFACE OF THIS LATTER. THE DRILLING TOOL OF THE INVENTION IS USED IN PARTICULAR FOR THE MACHINING OF HOLES OF DIFFERENT DIAMETERS.

Description

The present invention relates to a drilling tool

  (also hereinafter referred to as the "foraging tool) comprising an essential rod

  partially cylindrical and at least two cutting plates mounted so that they can be replaced on the front head of this rod and following which are provided at least two chip channels, in particular, in a spiral, extending vcrs a rear rod clamping piece and open to the outside. towards the peripheral surface

of this rod.

  Known drilling tools of this type (see patent application of the Federal Republic of Germany DE-AS 27 30 418) are no longer always required in practice. Despite the extremely careful machining of the drilling tools and the cutting plates used there, it may happen that chips become trapped or that the cutting edges are chipped. Since these phenomena generally occur deep inside a hole, these disturbances are not very

  often not immediately perceived, so that very often

  wind not only the cutting plate itself but

  also the drilling tool have deteriorated. These details

  riorations usually occur at the head of the stem.

  In this case, it may happen that the rod is so deteriorated that it is no longer able to perfectly maintain the cutting plates. Since, in the known drilling tool, the head and the clamping piece are one, the entire drilling tool must then be replaced with a new one. However, drilling tools of this type having working diameters of 50 mm and more are relatively expensive, while drilling tools having larger working diameters are generally not available from stock. Therefore, to the purchase costs, there is also an extension of the delivery time. Another disadvantage of known drilling tools lies in the fact that each drilling tool can only be used for a diameter of

work well determined.

  Consequently, the object of the invention is to provide

  a drilling tool of the type mentioned in the introduction above

  on it and which, when its head is damaged, can be re-

  put in state easily and economically as well from the material point of view as from the economic point of view, this tool being possibly able to machine, in a certain range

  of working diameters, holes of different diameters.

  According to the invention, this object is achieved because

  that the rod is at least in two parts, while the stem

  this clamp is removably assembled to the head which, on its rear face remote from the cutting plates, comes

  adapt, by a flat, radially extending surface

  Lately, on a corresponding flat front face (extending

  also radially) of the clamping piece, at least

  two cylindrical adjustment pins being inserted and

  fixed in the front face of the clamping piece, these pins

  ches coming to engage in corresponding adjustment chambers

  laying in the end face of the head on the

  which are also provided for retaining elements coming

  engage the adjustment pins or vice versa.

  Regardless of the extent of damage to the drill head, the damaged head can be

  removed from the clamping piece after loosening the

  retaining elements, this head then being replaced by a new one. The new head is much more economical than a complete drilling tool, since its manufacture requires only a fraction of the material necessary for the realization of a

  complete drilling tool and, in addition, many

  its machining steps which must be carried out on the rear clamping part. This clamping piece can be each

  once reused. By means of corresponding auxiliary elements

  dants, for example, drilling jigs, it is possible

  to adapt the new heads to the existing clamping parts

  aunts and reusable. In the drilling tool of the invention,

  the adjusting pins and the retaining elements which come

  are committed to it, play an important role. These pins of a-

  locking ensure perfect transmission of forces between the head and the clamping piece both in the peripheral direction

  only transversely to the axis of the drilling tool. Any-

  times they also serve to fix the head in a position

  predetermined with respect to the clamping piece. This character-

  is important so that the walls of the chip channels of the head come together without shoulder in

  the walls of the chip channels of the clamping piece. Cha-

  that a shoulder could disturb in particular the evacuation of

  chip> ,. In addition, the adjustment pins ensure the center

  age of the head vis-à-vis the clamping piece. Finally, the adjustment pins also serve to receive the retaining elements. This is also an important function because,

  due to chip channels and additional passages

  res formed in the head and clamp for an agent

  refrigerant, there is only a relatively small space

  treint for the installation of the retaining elements.

  Another advantage of the embodiment of the invention is that, in a certain range of working diameters, one head can be replaced by another having a slightly larger working diameter or a

  slightly smaller to obtain different working diameters

  vail. Likewise, heads of different lengths may be

  be mutually replaced in order to achieve larger

drilling depths.

  According to an advantageous embodiment of the invention, between the head and the clamping piece, at least one intermediate piece is introduced which, at its front end facing the head, is produced in the same way as 1 '

  front end of the clamping piece, while at its ex-

  rear end directed towards the clamping piece, it is

  performed in the same way as the back of the head.

  This embodiment provides a tool tool system.

  essentially variable rabies. Clamps having different conical rods adapted to the receptacles of the

  most diverse machine spindles can be made

  in the form of so-called "adapters", these clamping parts also being interchangeable. In this case, the assembly between the clamping parts and the

  intermediate piece takes place in the same way as the assembly

  normal blocking between a head and this clamping piece. The assembly point between the intermediate piece and the clamping piece is in particular provided at location c. The chip channels start in a normal one-piece drilling tool. By replacing the clamping parts, the drilling tool can then be used in the most diverse machine spindles. However, it is also possible to use intermediate pieces of different lengths and possibly of different diameters, intermediate pieces at the front end of which a head is fixed each time by means of adjustment pins and retaining elements. In this way, it is very easy to adapt the length and the diameter of

  the drilling tool for each machining process to be performed.

  A multi-part drilling tool of this type also has

  a more rigid behavior vis-à-vis the oscillations, because the various elements whose length is limited, are, in themselves, much less likely to cause

  oscillations and, in addition, they propagate the oscillations less

  at their different assembly points.

  In fact, there are known drilling tools comprising what are called drill bits; the drill bit supports exchangeable cutting plates

  and you can screw the front end of a hollow rod into it.

  In these drilling tools, the drill bit is also

  ment made in the form of a hollow cylindrical body. In these drilling tools, the chip evacuation is carried out by

  the inside of the drill bit and the inside of the ti-

  ge. For the assembly of this drill bit and

  this rod, this drill bit comprises an internal thread

  laughing, while the front end of the rod has an external thread. However, such a structure cannot be adopted for drilling tools whose rod has

  chip channels open to the outside.

  Other embodiments will be described below.

advantageous of the invention.

  Each adjustment spindle is assembled by screwing

  to the clamping piece or to the intermediate piece.

  According to one embodiment, at its end di-

  ribbed towards the clamping piece or the intermediate piece, each adjusting pin has a threaded rod which is screwed into a threaded hole in the clamping piece or the

intermediate piece.

  According to another embodiment, each adjustment pin has a central hole through which passes a fixing screw screwed into a threaded hole in the workpiece.

  clamping or intermediate piece.

  According to one embodiment, the retaining element

  is a retaining screw that can be screwed into the ra-

  dialing with respect to the axis of the adjusting spindle, this screw coming to engage, by a projection provided at its inner end, in the radial direction, in a cavity made

in the adjustment spindle.

  The projection is conical, while the cavity re-

  also tapers towards the axis of the adjusting spindle. The axis of the retaining screw is moved away from the end surface of the head by a distance slightly greater than the distance between the center of the cavity and the front face of

the clamping piece.

  According to another embodiment, each pin

  adjustment has a transverse hole extending radially-

  ment relative to the axis of the drilling tool and whose axis is spaced from the front face of the clamping piece by a distance slightly less than the distance between the axis of the retaining screw and the face in the end, while in the

  transverse hole, you can slide a retaining pin

  bare, the outer end of which, in the radial direction, facing the retaining screw, has a conical cavity, and the inner end of which, in the radial direction, engages, by a conical projection, in a conical cavity practiced in the head and whose center is arranged coaxially by

  relative to the axis of the retaining screw.

  According to this embodiment, each adjustment pin

  tage has a transverse hole extending radially relative to the axis of the drilling tool, and whose axis is spaced

  from the front face of the rod from a distance slightly

  less than the distance between the axis of a retaining screw

  before being screwed into the head radially with respect to the axis of the adjusting spindle, and the end face, while in

  the transverse hole, we can pass a pin

  held whose outer end, in the radial direction, turns

  born towards the retaining screw, engages, by a conical projection, in a conical cavity of the retaining screw and whose inner end, in the radial direction, comes to engage, by a conical projection, in a conical cavity practiced

  in the head and whose center is located coaxially with respect to

port to the axis of the retaining screw.

  The length of the retaining pin is less

  to the diameter of the adjusting pin.

  The angles at the top of the projections and the cavities are

equal and reach around 90.

  The invention will be described below in a more detailed manner.

  detailed with reference to illustrative examples illus-

  very in the attached drawings in which:

  - Figure 1 is a partial plan view and a section

  partial longitudinal pe of a first example of realization

  tion of the drilling tool of the invention;

  - Figure 2 is a side view of a second example-

  full of achievement; - Figure 3 is a partial longitudinal section of this embodiment, this section being taken along line III-III of Figure 4; - Figure 4 is a cross section taken along line IV-IV of Figure 3; - Figure 5 shows a complete drilling tool;

  - Figure 6 is a side view of a third example-

  full of achievement; - Figure 7 is a partial longitudinal section of

this example of realization.

  FIG. 5 illustrates the complete drilling tool 1

  carrying an essentially cylindrical rod. At the front head 3 of the rod, which can be detached from the clamping piece

  rear 2, at least two cutting plates 4 are provided for

  before being replaced. In addition, this rod has two ca-

  chip chips 5 of helical shape, following the t498502 cutting plates 4 and open towards the outside towards the peripheral surface of the rod. These chip channels extend from the cutting plates 4 towards the clamping part 2 of the rod. At the rear end of the clamping piece 2, the latter can also be produced in a cy-

  lindrique or, as shown in the drawing, it can include

  wear a cone 6 intended to be housed in a machine-

  tool. In addition, this clamping piece 2 also has a central passage 7 for a refrigerant, this passage being connected to two or more channels 8 provided in the head 3

  for this coolant. These channels 8 for a cooling agent

  manager open into the front end face 3a of the head 3 near the cutting plates 4. The refrigerant is conveyed to passage 7 via a ring (not shown) surrounding the clamping part 2, as well as via a transverse passage 9 provided in the clamping piece. As we can also

  see in Figures 2 and 5, the head 3 can be detached

  clamping piece 2. The head 3 is made in a short length relative to the clamping piece 2 and the

  point of assembly of this head 3 and this piece of service

  rage 2 is located in the area of chip channels 5.

  On its rear face away from the cutting plates 4,

  the head 3 has a flat end face 10 extending radially

  dialing and coming to be applied on a corresponding flat front face 11 (also extending radially) of the

  clamping piece 2. The front face il of the clamping piece

  ge 2 has two diametrically op- posite adjustment chambers 12

  placed and followed by coaxial threaded holes 13. In addition,

  provides two adjustment pins 14 each having a single

  threaded ge 15 at its end facing the workpiece

  rage 2. The adjusting pin is screwed into the threaded hole

  13 using this threaded rod 15 and thus, engages

manage in the adjustment chamber 12.

  In the end face 10 of the head 3, are provided

  two adjustment chambers 16 extending coaxially with respect to

  port to cylindrical adjustment pins 14. In these chambers

  adjustment bars 16, engage the front ends of the adjustment pins 14 protruding beyond the front face 11. In this way, the head 3 is fixed in a predetermined position facing the clamping piece 2 so that, as can be seen in FIG. 2, the walls

  chip channels 5 provided in the head 3 are placed

  cer exactly flush with the walls of the chip channels 5 pre-

seen in clamping piece 2.

  Each adjustment pin 14 has, at its end

  moth before, a transverse hole 17 extending radially by

  relative to axis B of the drilling tool. In this trans-

  versal 17, a retaining pin 18 can be passed.

  In addition, in the head 3, a retaining screw 19 is provided, the axis C of which also extends radially with respect to the axis B of the drilling tool. At its inner end, in the

  radial direction, the retaining screw 19 has a conical projection

  that 20 coming to engage in a corresponding conical cavity

  dante 21 formed in the retaining pin 18. In addition,

  at its inner end, in the radial direction, this bro-

  retaining che 18 has a conical projection 22 which engages in a corresponding conical cavity 23 formed in the head 3. The center Z of this conical cavity 23 is coaxial with the axis C of the retaining screw 19. The angles at the top of the conical projections 20, 22 and the cavities

  conical 21, 23 are equal and preferably reach between

about 900.

  In addition, it is important that the axis C of the retaining screw

  nude 19 is not located exactly at the D axis of the

  transverse hole 17. The axis C of the retaining screw 19 is also

  the end face 10 of the head 3 with a distance A which is slightly greater than the distance a between the axis D of the transverse hole 17 and the front face il of the clamping piece 2. The difference between the two distances A and a can

reach approximately 0.5 mm.

  When tightening the retaining screw 19, its conical projection 20 strikes the face of the conical cavity 21 of the retaining pin 18 which is distant from the front face 11. In this way, the retaining pin 18 is moved in the axial direction until its conical projection 22 abuts in the cavity 23 and, in fact, on the face which is

  turned towards the front face 11. In this way, a force di-

  rigged towards the p: The clamping species 2 is exerted on the head 3, this force having the effect of pressing the face firmly in

  tip 10 on the front face 11. If, for example, the pre-

  the drag of each of the two retaining screws is 2,000 kp, at the start of each retaining screw, a force of 4,000 kp is directed towards the axis of the drilling tool, thus generating a total pressing force of 8 .000 kp of head 3

  on clamping piece 2. This force is more than sufficient

  te especially since the transmission of the torsional moment takes place via the adjustment pins 14 undergoing a shear stress under the effect of this moment

of torsion.

  If the head 3 deteriorates, it is sufficient

  Please unscrew the retaining screws 19 and: You can then remove the retaining pins 18. In order to facilitate this

  operation, each retaining pin can also include

  ter a threaded hole in which one can screw a rod more

  long also with a net at its front end.

  By means of this rod, one can then remove each of the retaining pins from the transverse hole 17. Then, one can

  detach head 3 from adjustment pins 14 for replacement

  cer with a new one. Therefore, we do not have to renew each time

  veler que la tête 3. The material necessary for the realization

  tion of this head represents only about one seventh of the

  essential material for the creation of a training tool

complete rage.

  In the exemplary embodiment illustrated in FIGS.

  gures 2 to 4, the elements exercising the same function are de-

  signed by the same reference numbers so that the

  description above goes without saying. However in this example

  embodiment, the adjustment pin 14 'has a hole

  gitudinal 24. By means of a fixing screw 25 passing through this longitudinal hole 24 and coming to engage in the

  threaded hole 13, the adjustment pin 14 'is assembled iron-

  clamping piece 2. In the head 3 ', you can

  ser a retaining screw 19 radially with respect to the axis of the adjusting pin 14 '. This screw 1 engages, by its conical projection 20, in an annular cavity 26 whose cross section narrows in a cone in the direction of 1 '

  axis of the adjusting spindle. In this case too, the system

  teme is designed so that the C axis of the retaining screw

  bare 19 is distant from the end face 10 of the head 3 by a distance A which is slightly greater than the distance between the center Z of the cavity 26 and the front face 11. When tightening the screw retainer 19, its conical projection 20 abuts on one side only in the cavity 26 by pressing the head by its end face 10 against the front face 11. For

  replace head 3, just loosen some-

few retaining screws 19.

  Similarly, in the embodiment illustrated in Figures 6 and 7, the elements performing the same function

  are designated by the same reference numbers and the des-

  description given in connection with the illustrative example illus-

  tré in Figures 1 and 5 is also relevant. Any-

  times, in this example of realization, the retaining pin

  18 'and the retaining screw 19' are made somewhat different

  fiercely. The retaining pin has, at each of its two ends, a conical projection 22, 22a. The projection 22 engages in a conical cavity 23 formed in the

  head 3. The conical projection 22a cooperates with a conical cavity

  than 27 made in the retaining screw 19 '. In this case also

  Lement, the axis C of the retaining screw 19 'is spaced from the end face 10 by a distance A which is slightly greater than a distance a between the axis D of the transverse hole 17 and the face

  : rontale 11. When the retaining screw 19 'is tightened, its

  conical portion 27 strikes the face of the conical projection 22a which is turned towards the front face 11. In this way, the

  retaining pin 18 'is moved axially up to

  that its conical projection 22 abuts in the cavity 23 and, in fact, on the face which is also facing the

  front face 11. In this way, a force directed towards the part

  this tightening 2 is exerted on the head 3, this force also having the effect of firmly pressing the end face 10

on the front 11.

  The length of the retaining pin 18 'is advanced

  tagging slightly less than the diameter of the adjustment pin 14. In this way, when the retaining screw 19 'is loosened and when the two parts 3, 2 move 1' against each other, the retaining pin 18 'can penetrate

  completely in the transverse hole 17. Because its sail-

  lie 22 is conical in the same way as conical cavity 23, the

  retaining pin 18 'slides inside the trans-

  versal 17. Also in this exemplary embodiment, the an-

  gles at the top of the conical projections 22, 22a and the cavities

23, 27 are about 900.

  In order to better adapt the drilling tool to

  different machining cases, in the example embodiment il-

  glossy in FIG. 6, between the head 3 and the clamping piece 2 ′, an intermediate piece 28 is interposed which, at its end

  before 28a facing the head 3, is made in the same way

  that the front end of the clamping piece 2 ', tan-

  say that its rear end 28b faces the workpiece

  clamping 2 'is carried out in the same way as the rear face

  re of the head 3. Therefore, at the front end 28a, is pre-

  view of a flat front face 11 (extending radially) com-

  carrying adjustment pins 14 and, at the rear end 28b, is provided a flat end face 10 comprising

* corresponding adjustment chambers 16. The diameter of the pins

  adjustment chocks 14 and adjustment chambers 16, as well as

  their radial distance from the axis of the forming tool

  rage correspond to the intermediate part 28 of the corresponding system adapted to the head 3 and to the clamping part 2 ′,

  so head 3 could also be eventual-

  directly attached to the clamping piece 2 '.

  In the embodiment of the drilling tool illustrated in FIG. 6, in the event of deterioration, the head 3 can first of all be replaced in the same manner as in

  the embodiment described above. However, in-

  tre, the clamping piece 2 ′ can also be replaced.

  This replacement is necessary, for example, when the drilling tool is to be used in another machine whose spindle has another receptacle for the cone 6, for example, a receptacle having another cone angle. In this case, the clamping piece 2 'is replaced by another whose cone 6 adapts to the corresponding receptacle. Instead of

  of a cone, the clamping piece 2 ′ could also include

  ter a cylindrical rod or a mounting flange.

  Likewise, using different inter-

  diaries 28, the drilling tool can be very well adapted to each machining operation to be performed. Intermediate pieces 28 of different lengths can be used and it is also possible to use, for example, two or more intermediate pieces. In addition, on the rod 2 ', it is also possible to fix intermediate parts having a slightly larger or a little smaller diameter and we can then adapt heads

  having corresponding diameters.

  The intermediate piece 28 'also includes

  canals.! chips 5 which are advantageously helico-shaped

  dale. However, in FIG. 6, for reasons of clarity, these chip shackles are shown in a straight line. The assembly point between the intermediate piece 28 and the

  tightening 2 'is advantageously located at the point where is not

  not yet kills the start of chip channels 5.

  The invention is in no way limited to the embodiments described above. Thus, for example, in the clamping part 2 ′ illustrated in FIG. 6, it is also possible to adapt a head produced in the manner of a tool

core or crown drilling.

Claims (13)

CLAIMS.   1. Drilling tool comprising an essential rod-   cylindrical and at least two cutting plates mounted so that they can be replaced on the front head of this rod and following which are provided at least two chip channels, in particular, in a spiral, extending towards   a rear part for clamping the rod and open towards the ex-   térieur towards the peripheral surface of this rod, characterized in that the rod is made at least in two parts, while the clamping piece (2, 2 ') is assembled   removably to the head (3, 3 ') which, on its rear face   re distant from the cutting plates (4), comes to adapt, by a flat end surface and extending radially (10), on   a corresponding flat front face (11) (also extending   radially) of the clamping piece (2, 2 '), at least   two cylindrical adjustment pins (14, 14 ') being introduced   picks and fixed in, the front face (11) of the piece of   tightening (2, 2 '), these pins coming to engage in cham-   corresponding adjustment belts (16) made in the end face (10) of the head (3, 3 ') on which are also provided retaining elements (19, 19') engaging on   the adjustment pins (14, 14 ') or vice versa.   2. Drilling tool according to claim 1, ca-   characterized in that the head (3) is produced in a short length relative to the clamping piece (2), while   the assembly point of this head and this piece of service   rabies is located in the area of the chip channels (5).   3. Drilling tool according to any of the   vendications 1 and 2, characterized in that, between the head (3) and the clamping part (2 '), at least one intermediate part (28) is introduced which, at its front end (28a) turned   towards the head (3), is carried out in the same way as the ex-   front end of the clamping piece (2 '), while at its rear end (28b) directed towards the clamping piece (2'), it is produced in the same way as the rear face of the head (3).   4. Drilling tool according to any one of the   vendications 1 and 3, characterized in that each pin of a-   justage (14, 14 ') is assembled by screwing (13, 15, 25) to   the clamping piece (2) or to the intermediate piece.   5. A drilling tool according to claim 4, ca-   characterized in that, at its end directed towards the clamping piece (2 ') or the intermediate piece (28), each adjusting pin (14) has a threaded rod (15) which is screwed into a threaded hole (13) of the clamping piece (2,   2 ') or the intermediate piece (28).   6. A drilling tool according to claim 4, ca-   characterized in that each adjustment pin (14 ') has   in central hole (24) through which a fixing screw passes   tion (25) screwed into a threaded hole (13) in the service piece   rage (2, 2 ') or of the intermediate piece (28).   7. Drilling tool according to any of the   vendications 1 and 3, characterized in that the element of re-   held is a retaining screw (19) which can be screwed into the head (3, 3 ') radially with respect to the axis (E) of the   adjustment spindle, this screw coming to engage, by a sail-   lie (20) provided at its inner end, in the direction   dial, in a cavity in the adjustment spindle (21, 26).   8. A drilling tool according to claim 7, ca-   characterized in that the projection (20) is conical, while   the cavity (21, 26) also narrows in direction in direction   tion of the axis (E) of the adjusting spindle.   9. A drilling tool according to claim 8, ca-   characterized in that the axis of the retaining screw (19) is spread   tee of the end face (10) of the head (3, 3 ') of a cistance (A) which is slightly greater than the distance (a) between the center (Z) of the cavity (23, 26) and the front face (11) of the clamping piece (2).   10. Drilling tool according to any of the   vendications 7 and 8, characterized in that each pin of a-   justage (14) has a transverse hole (17) extending radially with respect to the axis (B) of the drilling tool and   whose axis (D) is spaced from the front face (11) of the part   this clamping (2) a distance (a) slightly greater than the distance (A) between the axis (C) of the retaining screw (19) and the end face (10) while in the hole transverse (17), a retaining pin (18) can be slipped, the outer end of which, in the radial direction, facing the retaining screw (19) has a conical cavity (21) and the inner end of which, in the radial direction, engages, by a conical projection (22), in a conical cavity (23) formed in the head (3) and whose center (Z) is disposed   coaxially with respect to the axis (C) of the retaining screw.   11. A drilling tool according to claim 1, ca-   characterized in that each adjustment pin (14) has a transverse hole (17) extending radially with respect to the axis (B) of the drilling tool and the axis (D) of which is spaced from the front face (11) of the rod (2 ') by a distance (a) slightly less than the distance (A) between the axis (C) of a   retaining screw (19 ') which can be screwed into the head (3)   dialing with respect to the axis of the adjusting spindle, and the end face (10), while, in the transverse hole (17),   you can pass a retaining pin (18 ') whose ex-   outer hopper, in the radial direction, turned towards the retaining screw (19 ') engages, by a conical projection (22a), in a conical cavity (27) of the retaining screw and   whose inner end, in the radial direction, comes   place a conical projection (22) in a conical cavity   (23) practiced in the head (3) and whose center (Z) is so-   killed coaxially with respect to the axis (C) of the retaining screw naked (19 ').   12. A drilling tool according to claim 11, ca-   characterized in that the length of the retaining pin   (18 ') is less than the diameter of the adjusting pin (14).   13. Drilling tool according to any one of   Claims 1 to 12, characterized in that the angles at   apex of the projections (20, 22, 22a) and of the cavities (21, 23,   27) are equal and reach approximately 90.