JP2008023626A - Boring tool and insert - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a boring tool capable of improving the dynamic balance and rigidity of a tool body, simply and highly precisely adjusting the position of an insert and highly precisely forming a bored hole with high circularity. <P>SOLUTION: This boring tool is characterized in that the tip of the tool body 21 is formed with a recess 30 and a mounting eye 31, the mounting eye 31 is attached with a flat insert 50 with its thickness direction facing axially O, a surface of the insert facing radially inside the tool body 21 is defined as a pushing object face 55, an outer circumferential cutting edge is formed on a ridge line of a cutting face 53 radially outside the tool device 21, the outer circumferential cutting edge is added with a back taper, and a pushing member 40 for pushing the pushing object face 55 of the insert 50 and adjusting the outer circumferential cutting edge to the radial position of the tool body 21 is disposed in the mounting eye 31 radially inside the tool body 21. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a drilling tool that is inserted into a prepared hole formed in advance in a workpiece and used to cut an inner wall surface of the prepared hole, and an insert that is detachably attached to the drilled tool.

  As this type of drilling tool, a reamer is known in which a cutting edge provided with a cutting edge is brazed to the tip of a long cylindrical tool body rotated about an axis. This reamer is rotated around the axis and fed in the axial direction, inserted into a prepared hole in the workpiece, and the inner wall surface of the prepared hole is formed by a cutting blade formed on the cutting edge. It cuts and forms the processing hole of a predetermined internal diameter.

  By the way, in the case where the blade edge portion is brazed to the tool body in this way, the position adjustment in the radial direction of the cutting blade cannot be performed, and the cutting blade position is determined by brazing accuracy. For this reason, it may not be possible to cope with machining of a machined hole having a very small required dimensional tolerance.

  Therefore, for example, as shown in Patent Document 1, a position adjusting mechanism that can detachably attach an insert having a cutting blade to the tip of a tool body and adjust the position of the cutting blade provided in the insert in the tool body radial direction. An insert-type reamer is provided. 7 and 8 show an example of an insert type reamer having a conventional position adjusting mechanism.

The reamer 1 shown in FIGS. 7 and 8 has a long cylindrical tool body 2 that rotates about an axis O, and the tool body 2 has a distal end side and an outer side in the radial direction of the tool body 2 on the outer periphery of the distal end side of the tool body 2. A recess 3 that is open toward the center is formed, and a mounting seat 4 is formed on the rear side of the recess 3 in the tool rotation direction T. Further, as shown in FIG. 8, a plurality of guide pads 5 are arranged on the outer periphery of the tool body 2 at equal intervals in the circumferential direction. The guide pads 5 are connected to the recesses 3 and the mounting seats 4. In the part which interferes, it forms so that it may reach to the front-end | tip of the tool main body 2 in the other part so that it may extend to the tool body 2 rear end side of these recessed parts 3 and the attachment seats 4.
A flat plate-like insert 6 having a cutting edge 6 </ b> A is seated on the mounting seat 4 with its thickness direction directed to the tool rotation direction T and fixed by a clamp screw 7.

  The cutting edge 6A of the insert 6 is directed to the outer side of the tool body 2 in the radial direction and the distal end side of the tool body 2, and an adjustment mechanism that adjusts the radial position of the insert 6 on the inner side of the tool body 2 in the radial direction. As shown, the two adjusting screws 8 and 9 are arranged in the direction of the axis O. An adjustment screw located on the rear end side of the tool body 2 is a first adjustment screw 8, and an adjustment screw located on the tip side of the tool body 2 is a second adjustment screw 9. These first and second adjustment screws The tip surfaces of the screws 8 and 9 are in contact with the surface of the insert 6 that faces the inside of the tool body 2 in the radial direction. In addition, an accommodation hole 10 opened toward the outer side in the radial direction of the tool body 2 is formed on the rear end side of the tool body 2 of the mounting seat 4, and the position of the insert 6 in the axis O direction is adjusted in the accommodation hole 10. The adjustment wedge 11 to be inserted is inserted.

The reamer 1 configured in this manner is mounted on the spindle end of the machine tool and rotated around the axis O, and is fed to the tip side in the direction of the axis O, and is prepared in a prepared hole formed in advance in the workpiece. When inserted, the inner wall surface of the prepared hole is cut by the cutting edge 6A of the insert 6 to form a processed hole having a predetermined inner diameter.
When performing this cutting, sliding of the inner wall surface of the processing hole and the guide pad 5 prevents the swing of the axis O of the reamer 1 to improve the dimensional accuracy.

In the reamer 1 having this configuration, the first adjusting screw 8 and the second adjusting screw 9 are used to make an inclination angle (back taper) with respect to the axis O of the cutting edge 6A formed on the insert 6 and the tool body 2 in the radial direction. The position can be adjusted, and a processing hole having a predetermined inner diameter can be formed with high dimensional accuracy, and even when the dimensional tolerance required for the processing hole is small, it is possible to cope with it. Further, by appropriately attaching the back taper, unnecessary contact between the inner wall surface of the machining hole and the insert 6 can be prevented, and cutting resistance can be reduced.
JP 2002-160124 A

  However, in the reamer 1 configured as described above, the flat insert 6 is attached so that the thickness direction thereof faces the tool rotation direction, and therefore the recess 3 positioned on the front side in the tool rotation direction T of the mounting seat 4. Needs to be opened largely. For example, in the reamer 1 shown in FIG. 8, the amount of depression at the most recessed portion in the radial direction of the tool body 2 in the cross section perpendicular to the axis O of the recess 3 is about 2/5 of the outer diameter of the tool body 2 (the tool body 2 The circumferential size of the recess 3 is about 1/5 to 1/4 of the outer circumference of the tool body 2. Since the recess 3 is large with respect to the tool body 2 in this way, the weight balance is poor in the cross section orthogonal to the axis O, and the dynamic balance when the tool body 2 is rotated at high speed around the axis O cannot be obtained. There is a possibility that the processing hole having high roundness cannot be formed with high dimensional accuracy due to variations in the position of the axis O.

  Furthermore, in order to form the recessed portion 3 and the mounting seat 4 in a large size, the plurality of guide pads 5 have a length up to the rear end side of the tool body 2 of the recessed portion 3, Could not slide in a well-balanced manner, and the axis O of the reamer 1 could be shaken. In addition, even when the recess 3 is made large in the direction of the axis O, the guide pad 5 may be shortened and the deflection of the axis O may be further increased.

  Further, the recess 3, the clamp screw hole 12 into which the clamp screw 7 is screwed, the adjustment screw holes 13 and 13 for accommodating the two adjustment screws 8 and 9, and the accommodation for accommodating the adjustment wedge 11 are provided at the tip of the tool body 2. It is necessary to form the hole 10, and there are many portions where the tool body 2 is notched, and the rigidity of the tool body 2 is insufficient, and vibration may occur when the tool body 2 is rotated at a high speed. In particular, in the case of the small-diameter reamer 1, since there is no space for forming the recess 3, the clamp screw hole 12, the adjustment screw hole 13, and the accommodation hole 10, an insert-type reamer having such an adjustment mechanism is used. Could not be provided.

  Further, the adjustment mechanism for adjusting the back taper and the adjustment mechanism for adjusting the tool body 2 radial position are the same first and second adjusting screws 8 and 9, and further the adjustment for adjusting the position of the insert 6 in the axis O direction. Since the wedge 11 is also provided, for example, when the position of the insert 6 in the radial direction of the tool body 2 and the direction of the axis O is adjusted after adjusting the back taper, the adjusted back taper has changed, and the adjustment is performed again. There was a need to do that. For this reason, much time and labor are required for the position adjustment of the insert 6, and the position adjustment of the insert 6 cannot be performed easily and accurately.

  The present invention has been made in view of the above-described circumstances, and reduces the notch portion of the tool body to improve the dynamic balance and rigidity of the tool body, and easily and accurately adjust the position of the insert. An object of the present invention is to provide a hole drilling tool that can form a hole with high roundness with high dimensional accuracy.

  In order to solve this problem, the hole drilling tool of the present invention is a hole drilling tool that is inserted into a pilot hole previously formed in a workpiece and cuts the inner wall surface of the pilot hole, At the tip of the tool body that is rotated to the tool body, a recess is formed that opens toward the tool body tip side and the tool body radially outward, and a mounting seat is formed on the rear side in the tool rotation direction of the recess. A flat plate-like insert is attached to the attachment seat with its thickness direction directed in the axial direction, and a surface of the insert facing the rear end side of the tool body is a seating surface, and the tool body of the insert The surface facing the inner side in the radial direction is the pressed surface, the surface facing the front side in the tool rotation direction of the insert is the rake surface, and an outer peripheral cutting edge is formed on the ridge line portion of the rake surface on the outer side in the tool body radial direction. At the tip of the tool body A front cutting edge is formed in the line portion, and the outer peripheral cutting edge is provided with a back taper so as to gradually recede toward the inner side in the radial direction of the tool body as it goes toward the rear end side of the tool body. A pressing member that presses the pressed surface of the insert and adjusts the tool body radial position of the outer peripheral cutting edge is arranged on the inner side in the tool body radial direction of the mounting seat.

  The insert of the present invention is an insert to be mounted on the above-described drilling tool. The outer shape is a flat plate, and one surface facing the thickness direction is a seating surface, and a side surface around the seating surface. One of these is a rake face, and an outer peripheral cutting edge and a front cutting edge are formed on a ridge line portion of the rake face, and the outer peripheral cutting edge is provided with a back taper.

In the hole drilling tool and the insert having this configuration, the outer periphery arranged on the outer side in the tool body radial direction of the insert by moving the insert to the outer side in the tool body radial direction by the pressing member arranged on the inner side in the tool body radial direction of the insert. The radial position of the cutting edge can be adjusted. In addition, since the outer peripheral cutting edge is already provided with a back taper so as to gradually recede toward the inner side in the radial direction of the tool body as it goes toward the rear end side of the tool body, it is necessary to adjust the back taper of the outer peripheral cutting edge. In addition, since the surface of the insert that faces the rear end side of the tool body is a seating surface and is attached to the mounting seat, it is positioned at a predetermined position in the axial direction. Therefore, it is necessary to adjust the position in the axial direction as well. Absent.
Therefore, it is only necessary to adjust the radial position of the outer peripheral cutting edge by operating the pressing member, so that the position adjustment of the insert can be performed easily and accurately.

  Further, as an insert, a so-called vertical blade having a flat plate shape, a surface facing the front side in the tool rotation direction being a rake surface, and an outer peripheral cutting edge formed on the ridge line portion on the outer side in the tool body radial direction of the rake surface. Since the insert is attached, it can be seated so that the thickness direction of the insert is substantially coincident with the axial direction of the tool body, and the portion where the tool body is notched to form the mounting seat can be reduced. While being able to do, the recessed part located in the tool rotation direction front side of a mounting seat can be made small.

  Moreover, since the part which forms a recessed part and a mounting seat can be made small, when arrange | positioning a guide pad on the outer periphery of a tool main body, the part which interferes with a recessed part and a mounting seat becomes small, and a tool main body front end side. Guide pads can be arranged in a well-balanced position close to each other, and sliding of the machining holes and the guide pads can reliably prevent deflection of the axis of the tool body, and can also form machining holes with high roundness. .

  Here, a direction in which a pressing pin having a pressing surface abutting on the pressed surface as a pressing member is formed on the inner side in the tool body radial direction of the mounting seat, intersecting the moving direction of the insert And a pressing screw that adjusts the pressing force when the insert is pressed by the pressing pin on the rear end side of the pressing pin. Can be adjusted to adjust the radial position of the outer peripheral cutting edge, and the position of the insert can be adjusted more easily. Further, since the pressing pin is arranged so as to extend in a direction intersecting the moving direction, it is not necessary to greatly cut out the rear side in the tool rotation direction of the mounting seat, and the rigidity and weight balance of the tool body can be improved. .

  Furthermore, as the insert, a cutting blade portion made of a diamond sintered body is provided, and the cutting blade portion is formed with the outer peripheral cutting blade and the front cutting blade, thereby providing wear resistance of the cutting blade. And the life of the insert can be extended.

  According to the present invention, the notch portion of the tool main body is reduced to improve the dynamic balance and rigidity of the tool main body, and the position adjustment of the insert can be easily and accurately performed. Can be provided with a dimensional accuracy.

Hereinafter, a drilling tool according to an embodiment of the present invention will be described with reference to the accompanying drawings. 1 to 3 show a reamer as a drilling tool according to an embodiment of the present invention. 4 to 6 show the insert.
The reamer 20 according to the present embodiment has a multi-stage cylindrical tool body 21 centering on the axis O, and a processing portion 22 in which the tip side (lower side in FIG. 1) of the tool body 21 forms a substantially cylindrical shape. On the rear end side of the tool body 21 (upper side in FIG. 1), a flange portion 23 having a diameter larger than that of the processed portion 22 is formed, and further on the rear end side of the flange portion 23, the reamer An attachment portion 24 to which a tool holder (not shown) for attaching 20 to the spindle end of the machine tool is attached is formed.

Further, a pilot 25 having a diameter smaller than that of the processing portion 22 is provided on the tip surface of the tool body 21. In the present embodiment, the pitot 25 has a shape in which a portion facing a side on which a later-described concave portion 30 and mounting seat 31 are formed is cut out.
Further, the tool body 21 is provided with a coolant supply hole 26 that opens to the mounting portion 24 and extends along the axis O and reaches a portion retracted from the tip surface of the tool body 21. A coolant discharge hole 27 extending from the hole 26 toward the outside in the radial direction of the tool body 21 and opening on the outer peripheral surface of the tool body 21 is formed.

On the distal end side of the tool main body 21 (processed portion 22), a recess 30 is formed that opens toward the distal end side and the radially outer side of the tool main body 21. As shown in FIG. 2, the wall surface 30 </ b> A on the rear end side of the tool body 21 of the recess 30 has a concave curved surface that is recessed toward the inside in the radial direction of the tool body 21 and toward the rear end side of the tool body 21. 30A has a coolant discharge hole 28 extending from the coolant discharge hole 27 toward the distal end side in the radial direction of the tool body 21 and the rear side in the tool rotation direction T.
And in this embodiment, the said recessed part 30 makes | forms the concave curvilinear shape recessed in the tool main body 21 radial direction inside in the cross section orthogonal to the axis line O, and goes to the tool body 21 rear end side. It is formed so as to extend parallel to the axis O.

  An attachment seat 31 for detachably attaching an insert 50 described later is formed on the rear side of the recess 30 in the tool rotation direction T. The mounting seat 31 is configured to be greatly recessed from the rear end of the recess 30 in the tool rotation direction T inward in the radial direction of the tool body 21 and to be greatly opened toward the distal end side of the tool body 21. That is, the mounting seat 31 includes a wall surface 31A facing the radially outer side of the tool body 21, a wall surface 31B facing the front side of the tool rotation direction T, a wall surface 31C facing the rear side of the tool rotation direction T, and the tip end side of the tool body 21. It has a facing wall surface 31D.

As shown in FIG. 2, a wall surface 31 </ b> D facing the distal end side of the tool body 21 of the mounting seat 31 is formed in a planar shape orthogonal to the axis O, and is parallel to the axis O on the wall 31 </ b> D. An extending clamp screw hole 32 is formed.
Moreover, as shown in FIG. 3 in the cross section orthogonal to the axis O, the wall surface 31C facing the tool rotation direction T rear side is formed along the tool body 21 radial direction, and the wall surface 31B facing the tool rotation direction T front side is The wall surface 31C is inclined so as to move backward in the tool rotation direction T as it goes outward in the radial direction of the tool body 21.

  Inside the tool body 21 in the radial direction of the mounting seat 31, an opening is made in the wall surface 31 </ b> A facing the tool body 21 in the radial direction of the mounting seat 31, and the tool rotation direction T is directed rearward along a plane orthogonal to the axis O. A pin hole 33 extending in a direction intersecting the direction in which the wall surface 31C extends is formed. A pressing screw hole 34 extending coaxially with the pin hole 33 is formed on the opposite side of the pin hole 33 from the mounting seat 31 side. The pressing screw hole 34 is one step larger in diameter than the pin hole 33 and has an internal thread formed on the inner peripheral surface. Further, the tool main body 21 is formed with a large-diameter hole 35 that communicates with the pressing screw hole 34 and opens on the outer peripheral surface of the tool main body 21.

A pressing pin 40 having a substantially cylindrical shape is inserted into the pin hole 33, and a pressing surface 40 </ b> A is formed at the tip of the pressing pin 40 so as to protrude outward in the radial direction of the tool body 21 and to the mounting seat 31. The pressing surface 40 </ b> A is inclined with respect to the axis of the pressing pin 40 so as to gradually go to the inner side of the pressing pin 40 as it goes toward the distal end side of the pressing pin 40.
A pressing screw 41 having a substantially cylindrical shape and a male screw formed on the outer peripheral surface is screwed into the pressing screw hole 34, and the front end surface of the pressing screw 41 is in contact with the rear end surface of the pressing pin 40. Yes. Further, an engagement hole (not shown) for engaging a work tool such as a wrench is formed on the rear end surface of the pressing screw 41, and this engagement hole is connected to the tool body via the large-diameter hole 35. 21 is exposed toward the outer peripheral surface.

  In addition, a plurality of guide pads 36 that are made of a hard material and whose outer shape forms a substantially oval plate shape are arranged on the outer peripheral portion of the processing portion 22 of the tool body 21 so as to extend in parallel with the axis O. In the present embodiment, as shown in FIG. 3, the six guide pads 36 are arranged at equal intervals in the circumferential direction. As shown in FIG. 1, the guide pad 36 </ b> A disposed at a portion that interferes with the recess 30 and the mounting seat 31 is formed to extend to the rear end of the tool body 21 of the recess 30, and the other guide pads 36 </ b> B. Is formed so as to reach the tip surface of the tool body 21.

Next, the insert 50 detachably attached to the attachment seat 31 of the tool body 21 will be described.
As shown in FIGS. 4 and 5, the insert 50 has a substantially rectangular flat plate shape, and has two rectangular surfaces and four side surfaces facing in the thickness direction. One square surface facing the thickness direction of the insert 50 is a seating surface 51 seated on the wall surface 31D facing the tip end side of the tool body 21 of the mounting seat 31 facing the rear end side of the tool body 21, and the thickness direction is The other facing surface is directed to the front end of the tool body 21 to be a front flank 52.

  One of the side surfaces of the insert 50 faces the front side of the tool rotation direction T as a rake face 53, and one of the other side faces connected to the rake face 53 faces toward the outer side in the radial direction of the tool body 21. 54. Further, the side surface that continues to the rake face 53 and faces the outer peripheral flank face 54 is directed to the inside of the tool body 21 in the radial direction, and is a pressed surface 55 that comes into contact with the pressing surface 40 </ b> A of the pressing pin 40.

At the corner where the front flank 52 and the outer peripheral flank 54 of the rake face 53 intersect, a flat cutting edge portion 56 made of a diamond sintered body is provided. An outer peripheral cutting edge 57 is formed at a crossing ridge line portion with the outer peripheral flank 54 of the cutting edge portion 56, and the insert 50 is a so-called vertical blade insert.
Further, a chamfered portion 58 is formed at the intersection of the front flank 52 and the outer peripheral flank 54, and a biting blade 59 is provided at the intersection ridge line portion between the chamfered portion 58 and the cutting edge portion 56.

Here, as shown in FIG. 5 when the insert 50 is viewed from the side facing the front flank 52, the rake face 53 and the pressed face 55 are arranged so as to intersect an obtuse angle.
Further, the outer peripheral flank 54 is inclined so as to recede toward the inside of the insert 50 as it is away from the rake face 53, and the rake face 53 and the outer peripheral flank 54 are arranged so as to intersect at an acute angle. Yes.
Further, as shown in FIG. 4, the outer peripheral flank 54 is inclined so as to gradually approach the pressed surface 55 toward the seating surface 51 as viewed from the side facing the rake surface 53.

  In the seating surface 51 and the front flank 52, an insertion hole 60 that penetrates in the thickness direction of the insert 50 is formed. The insertion hole 60 is a long hole extending in parallel with the side surface of the insert 50 facing the rake face 53. A clamp surface 61 with which the contact surface 72A of the clamp screw 70 abuts is formed in the vicinity of the insertion hole 60 of the other quadrangular surface that is the front flank 52. It is inclined with respect to a plane orthogonal to the insertion hole so as to gradually approach the seating surface 51 as it goes toward the flank 52 side.

  The insert 50 having such a configuration is attached to the attachment seat 31 of the tool body 21 as follows. The insert face 50 is brought into contact with the wall surface 31D facing the front end side of the tool body 21 of the mounting seat 31 so that the side face to be the rake face 53 faces the front side in the tool rotation direction T. 50 is placed on the mounting seat 31. Here, the pressed surface 55 of the insert 50 is in contact with the pressing surface 40A of the pressing pin 40, and the portion of the rake face 53 on the pressed surface 55 side faces the tool rotation direction T rear side of the mounting seat 31. It abuts on the wall surface 31C.

  In this state, the clamp screw 70 is inserted into the insertion hole 60 and screwed into the clamp screw hole 32 opened in the wall surface 31D facing the distal end side of the tool body 21 of the mounting seat 31. The clamp screw 70 includes a shaft portion 71 on which a male screw is formed and a head 72 having a diameter larger than that of the shaft portion 71, and a surface of the head 72 facing the shaft portion 71 side abuts. The surface 72 </ b> A is formed in a planar shape extending in a direction orthogonal to the shaft portion 71.

Therefore, the clamp screw 70 inserted through the insertion hole 60 is screwed into the clamp screw hole 32 opened in the wall surface 31D facing the front end side of the tool body 21 of the mounting seat 31, so that the head 72 of the clamp screw 70 is attached. The formed contact surface 72 </ b> A presses the clamp surface 61 of the insert 50, and the insert 50 is attached to the attachment seat 31.
Here, in the present embodiment, since the clamp surface 61 is inclined with respect to the plane orthogonal to the insertion hole 60, there is a slight gap between the portion on the outer peripheral flank 54 side of the clamp surface 61 and the contact surface 72A. A void is formed.

In the state where the insert 50 is mounted on the mounting seat 31 in this way, the outer peripheral flank 54 directed outward in the radial direction of the tool body 21 is as shown in FIG. 2 as viewed from the side facing the rake face 53. The tool body 21 is gradually inclined toward the inner side in the radial direction of the tool body 21 toward the rear end side of the tool body 21, and is formed at the intersection ridge line portion between the outer peripheral flank surface 54 and the cutting edge portion 56. The outer peripheral cutting edge 57 is gradually tapered toward the inner side in the radial direction of the tool body 21 as it goes toward the rear end side of the tool body 21. That is, a back taper is attached such that the diameter of the rotation trajectory when the outer peripheral cutting edge 57 is rotated about the axis O decreases toward the distal end side of the tool main body 21.
In the present embodiment, the back taper amount is set within a range of 40 μm / 15 mm to 80 μm / 15 mm, and more specifically, 60 μm / 15 mm.

  The reamer 20 constituted by attaching the insert 50 to the attachment seat 31 of the tool body 21 in this way is attached to the spindle end of the machine tool via the tool holder attached to the attachment portion 24, and the axis O It is rotated around and sent toward the front end side in the direction of the axis O, and inserted into a prepared hole formed in advance in the material to be cut. To form a processed hole having a predetermined inner diameter.

  In this cutting process, the coolant supplied from the machine tool is discharged from the coolant discharge hole 27 toward the inner wall surface of the machining hole through the coolant supply hole 26, and the guide pad 36 and the inner wall surface of the machining hole are slid. In addition to smooth movement, the coolant is discharged from the coolant discharge hole 28 toward the insert 50, and the outer peripheral cutting edge 57 and the biting edge 59 are cooled so that cutting can be performed satisfactorily.

In the reamer 20, the position of the insert 50 is adjusted as follows. The working tool is engaged with the engaging hole exposed on the outer peripheral surface of the tool body 21 through the large-diameter hole 35, the pressing screw 41 is screwed in, and the pressing pin 40 is moved toward the mounting seat 31 side. Here, the pressed surface 55 of the insert 50 is formed so as to intersect an obtuse angle with respect to the rake face 53 that is in contact with the wall surface 31C facing the tool rotation direction T rear side of the mounting seat 31, and the tool rotation direction. Since the tool body 21 is arranged so as to protrude inward in the radial direction of the tool body 21 toward the rear side, the pressing surface 40A presses the pressed surface 61 and the insert 50 moves the tip end side of the tool body 21 of the mounting seat 31. The tool body 21 moves outward in the radial direction in the direction orthogonal to the axis O along the facing wall surface 31D.
Therefore, by adjusting the pressing force of the insert 50 by the pressing pin 40 with the pressing screw 41, the radial position of the outer peripheral cutting edge 56 in the tool body 21 can be adjusted.

Further, the outer peripheral flank 54 of the insert 50 gradually recedes toward the inner side in the radial direction of the tool body 21 as it goes toward the rear end side of the tool body 21, and the outer peripheral cutting edge 57 has already been provided with a back taper, Since the back taper amount does not change even when the insert 50 moves outward in the radial direction of the tool body 21, it is not necessary to adjust the back taper of the outer peripheral cutting edge 57. Further, since the wall surface 31D facing the front end side of the tool body 21 of the mounting seat 31 is formed so as to be orthogonal to the axis O, the position of the insert 50 in the axis O direction does not change.
As described above, according to the reamer 20 according to the present embodiment, it is only necessary to adjust the radial position of the outer peripheral cutting edge 56 by operating the pressing screw 41, so that the position adjustment of the insert 50 is easily and accurately performed. be able to.

Further, as the insert 50, one surface that forms a rectangular flat plate shape and faces the thickness direction is a seating surface 51 that faces the inside of the tool body 21 in the radial direction, and a side surface that faces the front side in the tool rotation direction T is a rake surface 53. Since the so-called vertical blade insert 50 in which the outer peripheral cutting edge 57 is formed is attached to the intersecting ridge line portion of the rake face 53 and the outer peripheral flank face 54, the thickness direction of the insert 50 is set to the direction of the axis O of the tool body 21. The portion of the tool body 21 that is notched in order to form the mounting seat 31 can be made smaller, and the concave portion 30 positioned on the front side in the tool rotation direction T of the mounting seat 31 can be made smaller. can do.
Therefore, the dynamic balance and rigidity of the tool body 21 can be improved, the vibration of the tool body 21 can be prevented, and the machining hole can be formed with high dimensional accuracy. In addition, even an reamer that forms a small-diameter machining hole can constitute an insert-type drilling tool whose diameter can be adjusted.

  Here, in the present embodiment, the remaining guide pad 36B extends to the rear end side of the tool body 21 of the recess 30 and the mounting seat 31 so that one guide pad 36A of the six guide pads 36 extends to the tool body 21. Since the guide pad 36A disposed on the rear end side of the tool body 21 of the recess 30 and the mounting seat 31 is also formed so as to extend to the vicinity of the tip end side of the tool body 21, The machining hole and the guide pad 36 can be slid in a good balance in the vicinity of the insert 50 to be cut, and the axis O of the reamer 20 can be reliably prevented from swinging, and a machining hole having a high roundness can be accurately measured. Can be formed. And since a processing hole with high roundness can be formed, this reamer 20 should be used for processing a processing hole (for example, an engine cam hole) that requires a high dimensional tolerance that cannot be processed by the conventional reamer 20. This makes it possible to efficiently form such a processed hole.

  Further, a cutting blade portion 56 made of a diamond sintered body is formed on the insert 50, and an outer peripheral cutting edge 57 and a biting blade 59 are formed on the cutting blade portion 56. The wear resistance of the attached blade 59 can be improved, and the life of the insert 50 can be extended.

  Further, in the present embodiment, the clamp surface 61 of the insert 50 is inclined with respect to the plane orthogonal to the insertion hole 60, and the portion of the clamp surface 61 on the outer peripheral flank 54 side and the contact surface of the clamp screw 70 Since a slight gap is formed between 72A and 72A, when this insert 50 is pressed outward in the radial direction of the tool body 21, the clamp screw 70 is deformed so as to be bent by the gap, The insert 50 can be smoothly moved outward in the radial direction of the tool body 21.

As mentioned above, although the reamer which is embodiment of this invention was demonstrated, this invention is not limited to this, It can change suitably in the range which does not deviate from the technical idea of the invention.
For example, although it explained as a reamer provided with a collar part and a mounting part on the rear end side of the tool body, the present invention is not limited to this. For example, a tool without a collar part and having a substantially constant outer diameter over the entire length. A reamer having a main body and inserting the rear end portion of the tool main body into a mounting hole provided in the cutting tool may be used.

Furthermore, although it has been described that six guide pads are arranged at equal intervals in the circumferential direction, the present invention is not limited to this, and the arrangement and number of guide pads can be appropriately selected in consideration of cutting conditions and the like. preferable.
Moreover, although demonstrated as what has a pressing pin as a pressing member, it is not limited to this, You may arrange | position other pressing members, such as a wedge material.

  Further, the back taper amount attached to the outer peripheral cutting edge directed outward in the radial direction of the tool body is set within a range of 40 μm / 15 mm to 80 μm / 15 mm, more specifically 60 μm / 15 mm. However, the present invention is not limited to this, and the back taper amount can be appropriately set in consideration of cutting conditions and the like. However, by setting it within the range of this embodiment, the inner wall surface of the machining hole and the rear end side portion of the outer peripheral cutting edge are surely prevented from sliding, and the inner wall surface of the machining hole is finished smoothly. Is preferable.

In addition, the insert has been described as having a cutting blade portion made of a diamond sintered body, but the insert is integrally formed of a cemented carbide alloy or has a cutting blade portion made of a cBN sintered body. But it ’s okay.
Furthermore, the shape of the insert is not limited to this embodiment, and can be of any shape.

It is a side view of the reamer which is an embodiment of the present invention. It is an expanded partial sectional view of the front-end | tip part of the reamer shown in FIG. It is WW sectional drawing in FIG. It is the figure which looked at the insert which is embodiment of this invention from the side facing a rake face. It is a X direction arrow line view in FIG. It is a Y direction arrow directional view in FIG. It is an expanded partial sectional view of the front-end | tip part of the conventional reamer. It is ZZ sectional drawing in FIG.

Explanation of symbols

20 Reamer (Drilling tool)
21 Tool body 30 Recessed portion 31 Mounting seat 32 Clamp screw hole 40 Pressing pin (pressing member)
40A Pressing surface 41 Pressing screw 50 Insert 51 Seating surface 53 Drake surface 55 Pressed surface 56 Cutting edge portion 57 Outer peripheral cutting edge 70 Clamp screw

Claims (4)

A hole machining tool that is inserted into a pilot hole formed in advance in a workpiece and cuts the inner wall surface of the pilot hole,
A concave portion opened toward the distal end side of the tool body and the radially outer side of the tool body is formed at the distal end portion of the tool body rotated around the axis, and a mounting seat is formed on the rear side in the tool rotation direction of the recessed portion. And
A flat plate-like insert is attached to the attachment seat with its thickness direction directed in the axial direction, and a surface of the insert facing the rear end side of the tool body is a seating surface, and the tool body of the insert The surface facing the inner side in the radial direction is the pressed surface, the surface facing the front side in the tool rotation direction of the insert is the rake surface, and an outer peripheral cutting edge is formed on the ridge line portion of the rake surface on the outer side in the tool body radial direction. In addition, a front cutting edge is formed on the ridge line portion on the tip end side of the tool body, and the outer peripheral cutting edge gradually retreats toward the inner side in the radial direction of the tool body as it goes toward the rear end side of the tool body. Back taper is attached,
A pressing member that presses the pressed surface of the insert and adjusts the tool body radial position of the outer peripheral cutting blade is disposed on the inner side in the tool body radial direction of the mounting seat. Drilling tool. On the inner side in the tool body radial direction of the mounting seat, as the pressing member, a pressing pin formed with a pressing surface that comes into contact with the pressed surface at the tip extends in a direction intersecting the moving direction of the insert. Are arranged so that
The drilling tool according to claim 1, wherein a pressing screw for adjusting a pressing force when the insert is pressed by the pressing pin is disposed on a rear end side of the pressing pin. An insert to be mounted on the drilling tool according to claim 1 or 2,
The outer shape is a flat plate, and one surface facing the thickness direction is a seating surface, one of the side surfaces around the seating surface is a rake surface, and an outer peripheral cutting edge and a front cutting edge are formed on a ridge line portion of the rake surface. The insert is characterized in that the outer peripheral cutting edge has a back taper.   The rake face is provided with a cutting edge portion made of a diamond sintered body, and the outer peripheral cutting edge and the front cutting edge are formed on the cutting edge portion. 3. The insert according to 3.

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