JP2007320021A - Reaming tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reaming tool which improves a dynamic balance and rigidity of a tool body, simply and precisely makes a position adjustment of an insert, and forms a reamed hole having a high roundness with a precise dimension. <P>SOLUTION: A recess and a mounting seat 31 are formed at the front end part of a tool body 21, a wall surface 31B of the mounting seat 31 outward in the radial direction of the tool body 21 is inclined so as to gradually retreat inward in the radial direction of the tool body 21 as it goes toward the rear side of the tool body 22. The flat shape insert 50 is mounted in the mounting seat 31 by directing in the thickness direction toward the radial direction of the tool body 21, the surface toward the rear end side of the tool body 21 of the insert 50 is made to be a pressed surface 61, an outer peripheral cutting blade 56 is formed at a ridge line part of the outside in the radial direction of the tool body 21 of a cutting face, the outer peripheral cutting blade 56 has a back taper, and a pressing member 40 for pressing the pressed surface 61 is disposed at the rear end side of the tool body 21 of the mounting seat 31. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a hole machining 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.

  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. 4 and 5 show an example of an insert type reamer having a conventional position adjusting mechanism.

The reamer 1 shown in FIGS. 4 and 5 has a long cylindrical tool body 2 that is rotated around an axis O, and the tool body 2 is positioned on the outer periphery on the distal end side of the tool body 2 and on the outer side in the radial direction 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. 5, 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. 5, 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 to the rear end side of the tool body 2 of the recessed portion 3, and the guide pad 5 and the machining hole are formed on the distal end side of the tool body 2. 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, since the adjustment mechanism for adjusting the back taper and the adjustment mechanism for adjusting the radial position of the tool body 2 are the same first and second adjusting screws 8 and 9, for example, the tool body 2 after adjusting the back taper. When adjusting the position in the radial direction, the already adjusted back taper may change, and it may be necessary to adjust again. 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 present invention is 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, and is rotated about an axis. 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, and a mounting seat is formed on the rear side in the tool rotation direction of the recessed portion. The wall surface facing the tool body radial direction outer side is inclined so as to gradually recede toward the tool body radial direction inner side as it goes toward the tool body rear end side, and the mounting seat has a flat plate shape. An insert made is seated on the wall surface with its thickness direction directed in the radial direction of the tool body, and a surface facing the tool body rear end side of the insert attached to the mounting seat is a pressed surface. The tool rotation direction front side The facing surface is a rake face, and an outer peripheral cutting edge is formed on a ridge line portion of the rake face on the outer side in the radial direction of the tool body, and the outer peripheral cutting edge gradually increases in the direction toward the rear end side of the tool body. A back taper is attached so as to retreat toward the inner side in the radial direction of the tool body, and a pressing member that presses the pressed surface is disposed on the rear end side of the tool body of the mounting seat. It is said.

  In the hole drilling tool of this configuration, the wall surface facing the tool body radial direction outside of the mounting seat is inclined so as to gradually retreat toward the inside of the tool body radial direction toward the rear end side of the tool body. Since a pressing member that presses the pressed surface facing the tool body rear end side of the insert is disposed on the tool body rear end side of the mounting seat, the insert is inserted into the tool body tip by the pressing member. By moving it toward the side, the outer peripheral cutting edge of the insert can protrude outward in the tool body radial direction.

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. 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 flat plate shape is attached with its thickness direction facing the tool body radial direction, and the surface facing the front side in the tool rotation direction is a rake face, and the ridge line portion on the outer side in the tool body radial direction Since a so-called vertical blade insert having an outer peripheral cutting edge formed thereon is attached, the insert can be placed so that the thickness direction of the insert substantially coincides with the radial direction of the tool body, thereby forming a mounting seat. Therefore, it is possible to reduce the portion of the tool body that is notched, and to reduce the recess located on the front side of the mounting seat in the tool rotation direction. In addition, since the pressing member may be disposed on the rear end side of the tool main body of the mounting seat, the portion where the tool main body is cut out can also be reduced. Therefore, the dynamic balance and rigidity of the tool body can be improved to prevent vibration of the tool body, and the machining hole can be formed with high dimensional accuracy. Moreover, even if it is a hole-drilling tool which forms a small-diameter hole, an insert-type hole-drilling tool whose diameter can be adjusted can be configured.

  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, on the rear end side of the tool body of the mounting seat, an accommodation hole that opens to the outside in the radial direction of the tool body and communicates with the mounting seat is formed, and a pressing piece as the pressing member is formed in the accommodation hole. A slit is formed in the pressing piece so as to divide the tool body radial direction outer side portion of the pressing piece into a front end side and a rear end side of the tool main body, and an adjustment screw that spreads the slit is formed on the pressing piece. By screwing in the tool body radial direction, the slit of the pressing piece can be expanded by this adjusting screw to press the pressed surface of the insert, and the radial position of the outer peripheral cutting edge can be adjusted. The position of the insert can be adjusted more easily and reliably.

  Further, when the insert is pressed toward the distal end in the axial direction, an adjustment screw screwed in the radial direction of the tool body is screwed in, so that the tool body is greatly increased in the axial direction to provide a pressing member. There is no need to cut out. In addition, since the pressing piece is housed in the housing hole provided by cutting out the tool body, the weight balance of this reamer is taken, the dynamic balance when rotating around the axis improves, and the machining hole is made Further, it can be formed with high dimensional accuracy.

  Further, the insert is provided with a cutting edge portion made of a diamond sintered body, and the cutting edge portion is formed with the outer peripheral cutting edge, thereby improving the wear resistance of the cutting edge. This can extend the life of this insert.

  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 4 show a reamer as a drilling tool according to an embodiment of the present invention.
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.

Further, the tool body 21 is supplied with coolant that opens to the mounting portion 24 and extends along the axis O to reach a portion retracted from the front end surface of the tool body 21 by about 1/5 of the entire length of the processing portion 22. A hole 26 is formed.
In addition, the tool body 21 is provided with a coolant discharge hole 27 that opens from the coolant supply hole 26 toward the outer side in the radial direction of the tool body 21 in the outer peripheral surface of the tool body 21. As seen from the direction, as shown in FIG. 2, the tool extends in a direction perpendicular to each other while extending toward the front side of the tool rotation direction T and the rear side of the tool rotation direction T of the recess 30 from the portion where the later-described recess 30 is formed. A pair of extending coolant discharge holes 27 are formed.

  Further, in the tool body 21, the coolant discharge hole 27 disposed on the front side in the tool rotation direction T of the recess 30 of the pair of coolant discharge holes 27 is directed to the distal end side in the radial direction of the tool body 21 and the rear side in the tool rotation direction T. As shown in FIG. 2, a coolant discharge hole 28 extending in the direction is formed in the surface of the recess 30 facing the tip side of the tool body 21.

  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. In the present embodiment, as shown in FIG. 2, the recess 30 has a concave curve shape that is recessed inward in the radial direction of the tool body 21 in a cross section orthogonal to the axis O, and the axis line toward the rear end side of the tool body 21. The depth of the concave portion from the outer peripheral surface of the tool main body 21 at the bottom 30A of the concave curve (the most concave inward in the radial direction) is 1/5 of the outer diameter of the tool main body 21 ( The radius of the tool body 21 is about 2/5), and the size of the recess 30 in the circumferential direction is about 1/8 of the outer circumference of the tool body 21. Further, the length of the recess 30 in the direction of the axis O is set to about 1/20 of the entire length of the processed portion 22 as shown in FIG.

  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 has a wall surface 31A that faces the front side in the tool rotation direction T and a wall surface 31B that faces the outer side in the radial direction of the tool body 21, and the wall surface 31B that faces the outer side in the tool body 21 radial direction of the mounting seat 31 As shown in FIG. 2, it is comprised so that it may continue to the end (tool rotation direction T back side end) of the concave curve which makes the recessed part 30. As shown in FIG.

As shown in FIG. 3, the wall surface 31 </ b> B facing the tool body 21 radially outward of the mounting seat 31 gradually recedes toward the tool body 21 radially inward as it goes toward the rear end side of the tool body 21. The angle α formed by the axis O and the wall surface 31B facing the radial outside of the tool body 21 is set within a range of 1 ° ≦ α ≦ 15 °. In the present embodiment, , Α = 4 °. In addition, a clamp screw hole 32 extending in a direction orthogonal to the axis O is formed in the wall surface 31 </ b> B facing the tool body 21 diametrically outer side toward the tool body 21 diametrically inner side.
On the other hand, the wall surface 31 </ b> A facing the tool rotation direction T front side of the mounting seat 31 is arranged so as to extend in parallel with the axis O.

  As shown in FIGS. 3 and 4, the mounting seat 31 is provided with a receiving hole 33 that has a substantially rectangular cross section and opens outward in the radial direction of the tool body 21. Yes. As shown in FIG. 3, the tool body 21 radially outer portion of the accommodation hole 33 communicates with the mounting seat 31, and the bottom surface 33 </ b> A facing the tool body 21 radially outer side of the accommodation hole 33 is aligned with the axis O. It is formed to extend in parallel. In addition, as shown in FIG. 4, the concave portion 30 is not formed in front of the accommodation hole 33 in the tool rotation direction T.

  As shown in FIG. 4, the accommodation hole 33 accommodates a pressing piece 40 having a shape complementary to the accommodation hole 33 having a substantially rectangular cross section. In the pressing piece 40, the tool body 21 in the radial direction so as to divide the outer side portion of the pressing piece 40 in the radial direction of the tool body 21 into the distal end side and the rear end side of the tool body 21 in the state of being accommodated in the accommodation hole 33. A slit 41 is formed which opens to the outside and reaches about 7/10 of the entire length of the pressing piece 40.

  Further, as shown in FIG. 3, the pressing piece 40 is formed such that a portion located on the outer side in the radial direction of the tool body 21 in the state of being accommodated in the accommodation hole 33 protrudes toward the tip side of the tool body 21. The protruding portion is a pressing portion 42. The tool rotation direction T front side and rear side part on the tip side of the tool body 21 of the pressing part 42 are notched, and the surface located between the notched parts extends so as to be orthogonal to the axis O and is pressed. The surface 43 is used.

  Furthermore, a surface 40A of the pressing piece 40 facing the bottom surface 33A of the accommodation hole 33 and facing the inner side in the radial direction of the tool body 21 is formed with the distal end side of the tool body 21, that is, the pressing portion 42 as shown in FIG. The inner portion of the tool main body 21 in the radial direction is inclined so as to be separated from the bottom surface 33A as it goes toward the distal end side of the tool main body 21, and the bottom surface 33A of the receiving hole 33 and the tool main body 21 diameter of the pressing piece 40 A space is formed between the surface 40A facing inward.

  The pressing piece 40 has an adjustment screw hole that opens toward the radially outer side of the tool body 21 and extends toward the radially inner side of the tool body 21 along the slit 41 while being accommodated in the accommodation hole 33. 44 is formed, and an outer portion of the adjustment screw hole 44 in the radial direction of the tool body 21 is a tapered hole 44A that gradually decreases in inner diameter in the radial direction of the tool body 21. An adjustment screw 45 having a head portion 45A that fits into the taper hole 44A is screwed into the adjustment screw hole 44.

  A plurality of guide pads 35, which 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 parallel to the axis O. In the present embodiment, as shown in FIG. 2, the six guide pads 35 are arranged at equal intervals in the circumferential direction. Further, as shown in FIG. 1, the guide pad 35 </ b> A disposed in a portion that interferes with the recess 30 and the mounting seat 31 is formed so as to extend to the rear end of the tool body 21 of the accommodation hole 33, and other guides. The pad 35B 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. 3 and 4, the insert 50 has a substantially rectangular flat plate shape, and has two surfaces facing the thickness direction and four side portions. One surface facing the thickness direction of the insert 50 is a seating surface 51 seated on a wall surface 31B facing the tool body 21 radial direction outside of the tool body 21 and facing the tool body 21 radial direction inside. The other facing surface faces the radially outer side of the tool body 21 and is an outer peripheral flank 52.
An insertion hole 53 penetrating in the thickness direction of the insert 50 is formed in one of these surfaces (the seating surface 51) and the other surface (the outer peripheral flank 52).

  One of the side surfaces of the insert 50 is a rake face 54 facing the front side of the tool rotation direction T, and diamond sinter is formed on one end side of the side face forming the rake face 54 (tip side of the tool body 21). A flat cutting edge portion 55 formed of a body is provided. An outer peripheral cutting edge 56 is formed at an intersecting ridge line portion with the other surface (outer peripheral flank 52) facing the thickness direction of the cutting edge portion 55, and a so-called vertical blade insert 50 is formed.

In addition, the side portion facing the front end side of the tool body 21 in the state of being mounted on the mounting seat 31 is a front flank 57, and the side portion which is the front flank 57 and the other peripheral flank 52. A chamfered portion 58 is formed at an intersection with the surface, and a biting blade 59 is provided at an intersecting ridge line portion between the chamfered portion 58 and the cutting edge portion 55. That is, when viewed from the side facing the rake face 54, the biting blade 59 inclined so as to recede inwardly in the radial direction of the tool body 21 as it goes toward the tip side of the tool body 21 is the tip of the tool body 21 of the outer peripheral cutting edge 56. It is arranged to be connected to the side. Further, a front cutting edge 60 is formed at the intersecting ridge line portion between the front flank 57 and the cutting edge portion 55, and is arranged so as to continue to the inner side in the radial direction of the tool body 21 of the biting blade 59.
As shown in FIG. 4, the front relief surface 57 is formed with relief so as to gradually recede toward the rear end side of the tool body 21 as it goes toward the rear side in the tool rotation direction T.

Moreover, the side part located on the opposite side of the side part made into the rake face 54, that is, the side part facing the rear side in the tool rotation direction T is arranged in parallel to the axis O as shown in FIG. .
The side surface portion of the insert 50 facing the rear end side of the tool body 21 has a notched intersection ridge line portion with the other side surface portion continuous to the front side and the rear side in the tool rotation direction T. A surface located between the portions is a pressed surface 61 that extends in a direction orthogonal to the axis O and contacts the pressing surface 43 of the pressing piece 40.

  Further, the outer peripheral flank 52 directed outward in the radial direction of the tool body 21 gradually increases in the diameter of the tool body 21 as viewed from the side facing the rake face 54 toward the rear end side of the tool body 21 as shown in FIG. Inclined with respect to the axis O so as to be directed inward in the direction, the outer peripheral cutting edge 56 formed at the intersecting ridge line portion of the outer peripheral flank 52 and the cutting edge portion 55 is directed toward the rear end side of the tool body 21. Accordingly, the back taper is gradually applied to the inner side of the tool body 21 in the radial direction. 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 insert 50 having such a configuration is attached to the attachment seat 31 of the tool body 21. The insert 50 is seated so that the side surface portion that is the rake face 54 faces the front side of the tool rotation direction T, and one surface (sitting surface 51) facing the thickness direction of the insert 50 is the tool body of the mounting seat 31. The pressed surface 61 is disposed so as to be in contact with the pressing surface 43 of the pressing piece 40 while being in contact with the wall surface 31 </ b> B facing outward in the 21 radial direction. In this state, by inserting the clamp screw 62 inserted into the insertion hole 53 into the clamp screw hole 32 opened in the wall surface 31B facing the tool body 21 in the radial direction of the attachment seat 31, the insert 50 is attached to the attachment seat. 31 is attached.

  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 book holder attached to the attachment portion 24, While being rotated around the axis O, it is sent toward the front end side in the direction of the axis O, and inserted into a prepared hole formed in advance in the workpiece, and the front wall 60 and the bite of the inner wall surface of this prepared hole are inserted. Cutting with the blade 59 and the outer peripheral cutting edge 56 forms a processing hole with 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 via the coolant supply hole 26, and the guide pad 35 and the machining hole inner wall surface are slid. The movement is smooth, and the coolant is discharged from the coolant discharge hole 28 toward the insert 50, and the outer peripheral cutting blade 56, the biting blade 59, and the front cutting blade 60 are cooled, so that cutting can be performed satisfactorily.

  Here, the position adjustment of the insert 50 in the reamer 20 is performed as follows. When the adjusting screw 45 screwed into the adjusting screw hole 44 of the pressing piece 40 is screwed in, the head 45A of the adjusting screw 45 moves inward in the radial direction of the tool body 21, and the tapered hole 44A of the pressing piece 40 expands. The slit 41 of the pressing piece 40 is expanded. Then, the tool body 21 of the pressing piece 40 is elastically deformed so that the front end side and the rear end side thereof are separated from each other, but the rear end side is in contact with the surface of the accommodation hole 33 facing the front end side of the tool body 21. Can not move because. On the other hand, the distal end portion of the tool body 21 relative to the slit 41 of the pressing piece 40, that is, the pressing portion 42, has a space between the bottom surface 33 </ b> A of the accommodation hole 33 and the surface 40 </ b> A facing the radially inner side of the tool body 21 of the pressing piece 40. In addition, since the distal end side of the tool main body 21 is communicated with the mounting seat 31, it is deformed so as to bend toward the distal end side of the tool main body 21.

  When the pressing portion 42 of the pressing piece 40 is elastically deformed as described above, the pressing surface 43 facing the distal end side of the tool body 21 of the pressing portion 42 presses the pressed surface 61 of the insert 50, and the insert 50 is attached to the mounting seat. The tool body 21 moves toward the distal end side of the tool body 21 along a wall surface 31B facing the radially outer side of the tool body 21 and a wall surface 31A facing the front side in the tool rotation direction T. Here, the wall surface 31B facing the tool body 21 radially outward of the mounting seat 31 is inclined with respect to the axis O so as to gradually recede toward the tool body 21 radially inward as it goes toward the rear end side of the tool body 21. Therefore, the insert 50 protrudes toward the outer side in the radial direction of the tool body 21 as it goes toward the distal end side of the tool body 21.

Further, the outer peripheral flank 52 of the insert 50 gradually recedes inward in the radial direction of the tool main body 21 as it goes toward the rear end side of the tool main body 21, and is formed at the intersection ridge line portion between the outer peripheral flank 52 and the rake face 54. The outer peripheral cutting edge 56 is already provided with a back taper, and this back taper amount does not change even when the insert 50 moves in the direction of the axis O. Therefore, it is necessary to adjust the back taper of the outer peripheral cutting edge 56. Absent.
Therefore, in 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 adjustment screw 45, so that the position adjustment of the insert 50 can be performed easily and accurately.

  Furthermore, 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 main body 21 in the radial direction, and the other surface that faces the thickness direction is the radial direction of the tool main body 21. An outer peripheral flank 52 is formed on the outer side, a side surface directed toward the front side of the tool rotation direction T is a rake face 54, and an outer peripheral cutting edge 56 is formed at a cross ridge line portion between the rake face 54 and the outer peripheral flank 52. Since the vertical blade insert 50 is attached, the insert 50 can be attached so that the thickness direction of the insert 50 substantially coincides with the radial direction of the tool body 21, and the tool body 21 is notched to form the attachment seat 31. While being able to make a part small, the recessed part 30 located in the tool rotation direction T front side of the attachment seat 31 can be made small. 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. Moreover, even if it is an insert-type reamer which forms a small diameter processing hole, a diameter adjustment mechanism can be provided.

  Here, in the present embodiment, the amount of dent from the outer peripheral surface of the tool body 21 of the bottom 30A of the concave curve formed by the cross section orthogonal to the axis O of the recess 30 (the most concave portion inward in the radial direction) is the tool body 21. Of the six guide pads 35 formed on the outer periphery of the machining portion 22, the outer diameter of the tool body 21 is about 1/5 (2/5 of the radius of the tool body 21). One guide pad 35A is formed so as to extend to the rear end side of the tool body 21 of the recess 30 and the mounting seat 31, and the remaining five guide pads 35B are formed so as to reach the tip surface of the tool body 21. Can do. Further, since the length of the concave portion 30 in the direction of the axis O is shortened to about 1/20 of the entire length of the processed portion 22, the guide pad 35A disposed on the rear end side of the tool body 21 of the concave portion 30 and the mounting seat 31 is also provided. The tool body 21 can be formed so as to extend to the vicinity of the tip end side.

  By arranging the guide pad 35 in this manner, the machining hole and the guide pad 35 can be slid in a balanced manner in the vicinity of the insert 50 to be cut, and the swing of the axis O of the reamer 20 can be reliably prevented. Further, it is possible to form a processed hole with high roundness with high dimensional accuracy. Since a processing hole having a high roundness can be formed in this way, this reamer 20 is 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. Thus, such a processed hole can be formed efficiently.

  Further, a pressing piece 40 having a slit 41 is accommodated in an accommodation hole 33 that opens to the outside of the tool body 21 in the radial direction and communicates with the mounting seat 31, and is screwed to the pressing piece 40 in the radial direction of the tool body 21. Since the cutout portion 40 of the tool body 21 is reduced and the pressing piece 40 is accommodated in the accommodation hole 33, it is easy to balance the weight of the reamer 20, and the reamer 20 is rotated around the axis O. As a result, the dynamic balance is improved, and the processed hole can be formed with higher dimensional accuracy.

  Further, a cutting blade portion 55 made of a diamond sintered body is formed on the insert 50, and an outer peripheral cutting blade 56, a front cutting blade 60, and a biting blade 59 are formed on the cutting blade portion 55. The wear resistance of the cutting blade 56, the front cutting blade 60, and the biting blade 59 can be improved, and the life of the insert 50 can be extended.

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.

In addition, although a description has been given using a pressing piece as a pressing member of the insert, the present invention is not limited to this. For example, other pressing members that press the pressed surface of the insert with the tip of a pressing screw are applied. May be. However, the configuration as in this embodiment is preferable because the insert can be reliably pressed and the dynamic balance of the tool body can be easily obtained.
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.

  Also, the angle α formed by the wall surface of the mounting seat facing the tool body radial direction and the axis is set within a range of 1 ° ≦ α ≦ 15 °, and more specifically, α = 4 °. However, the present invention is not limited to this, and the angle α can be set as appropriate. However, setting within the range of the present embodiment is preferable because the radial position of the outer peripheral cutting edge can be adjusted with high accuracy by adjusting the position of the insert in the axis O direction.

  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 XX sectional drawing in FIG. It is an expanded partial sectional view of the front-end | tip part of the reamer shown 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 Recess 31 Mounting seat 31B Wall surface 32 facing the tool body radially outward Clamp screw hole 33 Housing hole 40 Pressing piece (pressing member)
41 Slit 45 Adjustment screw 50 Insert 54 Rake face 55 Cutting edge 56 Peripheral cutting edge 61 Pressed face 62 Clamp screw

Claims (3)

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
The wall surface of the mounting seat that faces the radially outer side of the tool body is inclined so as to gradually recede toward the radially inner side of the tool body as it goes toward the rear end side of the tool body.
In the mounting seat, a flat-shaped insert is seated on the wall surface with its thickness direction oriented in the tool body radial direction, and the surface of the insert attached to the mounting seat faces the tool body rear end side. Is a rake face that faces the front side in the tool rotation direction of the insert, and an outer peripheral cutting edge is formed on a ridge line portion of the rake face on the radially outer side of the tool body. The cutting edge is attached with a back taper so as to gradually retreat toward the inner side in the tool body radial direction as it goes toward the rear end side of the tool body,
A drilling tool, wherein a pressing member that presses the pressed surface is disposed on the rear end side of the tool body of the mounting seat. On the rear end side of the tool body of the mounting seat, there is formed a receiving hole that opens to the outside in the radial direction of the tool body and communicates with the mounting seat, and a pressing piece is received in the receiving hole as the pressing member. Has been
The pressing piece is formed with a slit so as to divide the outer portion of the pressing piece in the radial direction of the tool body into a front end side and a rear end side of the tool main body, and an adjustment screw that spreads the slit The drilling tool according to claim 1, wherein the drilling tool is screwed toward the radial direction of the main body.   The insert is provided with a cutting edge portion made of a diamond sintered body, and the outer peripheral cutting edge is formed in the cutting edge portion. The drilling tool described.

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