JP2007069306A - Cutting tool and insert - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting tool capable of suppressing defects of a machining hole opening part, efficiently performing cutting without reducing the number of effective inserts, and reducing costs for using the inserts, and the inserts. <P>SOLUTION: This cutting tool 1 cuts the inner wall surface of a prepared hole. The insert is formed into a polygonal flat shape, and one of side faces is made as a rake face. A cutting blade having a corner blade is provided at a corner formed of an intersecting ridge line of the rake face and polygonal faces 31A and 31B and an intersecting ridge line of the rake face and an other side face adjacent to the rake face. A first mounting seat 20 and a second mounting seat 21 are provided on the outer periphery of the tip of a tool body 10. In the inserts 30 mounted on the first and second mounting seats 20 and 21, the corner blades on mutually opposite polygonal face sides are directed to the radial direction outside the tool body 10. In the corner blades, one of the corner blades is arranged on the tip side of the tool body 10 and at the tool body 10 radial direction inside the other corner blade. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention provides a cutting tool such as a boring cutter used when cutting an inner wall surface of a prepared hole provided in a workpiece in advance to form a machining hole having a predetermined inner diameter, and the cutting tool is attached to the cutting tool. Regarding inserts.

2. Description of the Related Art Conventionally, as a cutting tool used for machining a cylinder bore of an engine, for example, a boring cutter in which an insert having a cutting blade is detachably mounted on the outer periphery of a tip portion of a tool body rotated around an axis is known. (See Patent Document 1).
As an insert to be attached to such a cutting tool, the outer shape is a rectangular flat plate shape, the rectangular surface is a front relief surface, and one of the four side surfaces around the rectangular surface is a rake surface. A so-called vertical blade insert may be used in which a cutting blade is provided that extends along a crossing ridge line portion between a rectangular surface and a rake surface as a flank.

In the cutting tool having such a configuration, the tool body is attached to the spindle end of the machine tool through an adapter or the like, and is rotated at high speed around the axis of the tool body and is fed in the axial direction. The inner wall surface of the prepared hole is cut by an insert cutting blade that is inserted into a prepared hole provided in advance in the material and attached to the outer periphery of the tip end of the tool body to form a processed hole having a predetermined inner diameter.
Registered Utility Model No. 2585714

  By the way, in the above-mentioned cutting tool, while feeding the axial direction while cutting the inner wall surface of the pilot hole, the machining hole is formed, but when the cutting tool is protruded from the workpiece at the end of machining, In addition, a part of the opening of the processed hole may be lost. In particular, when the cutting amount of the cutting tool (inner diameter difference between the prepared hole and the machining hole) is large, there is a problem that the chip generated in the opening of the machining hole becomes large and the machining hole cannot be formed with high accuracy. .

  Here, by reducing the cutting amount of the cutting tool, it is possible to suppress the chipping in the opening portion of the processing hole, but in order to process the pilot hole to a predetermined inner diameter, for example, processing was performed with a cutting tool for roughing A plurality of cutting tools will be used, such as re-inserting a cutting process for finishing, and the processing efficiency will be reduced.

  In order to reduce the cutting amount of each insert while ensuring the cutting amount of the entire cutting tool, adjust the position of the cutting blade in the tool body radial direction and the axial direction of a plurality of inserts provided in the tool body, For example, half of the plurality of inserts provided in the cutting tool may be used for roughing, and the other half may be used for finishing. However, if the insert provided on the tool body is divided for roughing and finishing, the number of effective blades that can be used during roughing and finishing decreases, so the cutting tool feed can be reduced. Therefore, it becomes impossible to process efficiently.

Therefore, in order to ensure the cutting amount of the cutting tool without reducing the number of effective blades at the time of roughing and finishing, inserts are respectively arranged for roughing and finishing. It is necessary to provide twice as many inserts as the cutting tool.
Here, in the cutting tool shown in Patent Document 1, when the inserts are arranged for roughing and finishing, it is necessary to replace all the inserts when the cutting blade is worn by use. Therefore, there is a problem that a set of inserts can be used only until the insert is mounted on the tool body and the cutting edge of the insert is worn, and the amount of inserts used increases and the usage cost increases.

  The present invention has been made in view of the above-described circumstances, and can reduce the cutting amount of each insert by dividing the cutting amount of the entire cutting tool, and can suppress the chipping of the processing hole opening, and can also perform rough processing. An object of the present invention is to provide a cutting tool and an insert that can be efficiently cut without reducing the number of effective inserts at the time of finishing and finishing, and that can reduce the cost of using the insert.

  In order to achieve the above object, a cutting tool according to the present invention has a tool body that is rotated around an axis, and a plurality of inserts of the same shape and size. A cutting tool that is inserted and cuts the inner wall surface of the pilot hole, wherein the insert has a polygonal flat plate shape and has two polygonal surfaces, and has a side surface around the polygonal surface. One of them is a rake face, and the insert includes a cross ridge line portion between the rake face and the two polygonal faces, and a cross ridge line portion between the rake face and another side face adjacent to the rake face. A cutting edge having a corner blade at each corner, and the insert is mounted on the outer periphery of the tip of the tool body with the one polygonal surface as a front flank. The second mounting mounted on the other polygonal surface as the outer peripheral flank In the inserts mounted on the first and second mounting seats, the corner blades on the polygonal surface side opposite to each other are directed outward in the tool body radial direction, and one corner blade Is arranged at the tip end side of the tool body and the inner side in the tool body radial direction of the other corner blade.

  Further, an insert according to the present invention is an insert that is inserted into a prepared hole provided in a work material in advance and is attached to the cutting tool for cutting an inner wall surface of the prepared hole, and has an outer shape of a polygonal flat plate The insert body has two polygonal surfaces and one of the side surfaces around the polygonal surface is a scooping surface. Joined along the rake face, at the corner formed by the ridge line part of the rake face and the two polygonal faces, and the ridge line part of the rake face and another side surface adjacent to the rake face. It is characterized in that a cutting blade having a corner blade is provided.

  In the cutting tool having the above configuration, the first mounting seat and the second mounting seat are provided. For example, the insert mounted on the first mounting seat is used for roughing, and the insert mounted on the second mounting seat. By using for finishing, it is possible to reduce the cutting amount of each insert while securing the cutting amount of the entire cutting tool. Therefore, when this cutting tool is protruded from the material to be cut at the end of machining, it is possible to prevent the machining hole opening from being lost.

  Further, in the inserts mounted on the first and second mounting seats, the corner blades on the polygonal surface side opposite to each other are directed outward in the radial direction of the tool body, and one corner blade is the other corner. Since the blade is disposed on the distal end side of the tool body and on the radially inner side of the tool body, for example, the corner blade of the insert mounted on the first mounting seat is the tool of the corner blade of the insert mounted on the second mounting seat. In the case where they are arranged on the front end side of the main body and the inside of the tool main body in the radial direction, finishing can be performed with the insert attached to the second mounting seat after roughing with the insert attached to the first mounting seat. Therefore, even if a small chipping occurs when the insert to be roughed is protruded from the work material, the chipped part can be processed with the insert for finishing, and the processing hole can be formed with high accuracy. it can.

  Also, since the first mounting seat has one polygonal surface as the front clearance surface and the second mounting seat has the other polygonal surface as the outer peripheral clearance surface, the corner blades directed radially outward of the tool body are the first mounting surface. Different from the case of being mounted on the seat and the case of being mounted on the second mounting seat, the insert mounted and used on the first mounting seat can be used by mounting on the second mounting seat. Therefore, since it can be used until two corner blades are worn by one set of inserts, the cost of using the inserts can be reduced.

  In the insert having the above-described configuration, the insert has a polygonal flat plate shape and has two polygonal surfaces, and one of the side surfaces around the polygonal surface is a rake surface. Since the cutting blade part that is harder than the main body is joined along the rake face, the wear resistance of the part that comes into contact with the work material can be increased, and the life of the insert can be extended. Can do.

  In addition, by configuring the cutting edge portion with CBN (Cubic Boron Nitride), it is possible to further improve the wear resistance of the cutting edge and further extend the life of the insert. Moreover, since only the cutting edge part used for cutting is comprised by CBN, this insert can be manufactured at low cost.

  As described above, according to the present invention, the cutting amount of the entire cutting tool is divided to reduce the cutting amount of each insert, and it is possible to suppress the chipping of the opening of the processing hole, and it is effective at the time of roughing and finishing. It is possible to provide a cutting tool and an insert that can be cut efficiently without reducing the number of inserts and that can reduce the cost of using the insert.

Embodiments of the present invention will be described with reference to the accompanying drawings.
1 and 2 show a boring cutter which is a cutting tool of this embodiment. FIG. 3 shows the arrangement of the insert. FIG. 4 and FIG. 5 show an insert attached to this boring cutter.
The boring cutter 1 includes a disk-shaped tool body 10 and an insert 30 attached to the outer periphery of the tip end of the tool body 10.

The tool body 10 is made of a steel material or the like, and as shown in FIGS. 1 and 2, the outer shape thereof is formed in a disk shape centering on the axis O, and is on the tool body rear end side (upper side in FIG. 1). Is provided with a fitting portion 11 to be fitted into the mounting opening of the adapter A. Further, two key grooves 12 having a rectangular cross section are provided in a portion of the rear end surface of the tool body 10 where the insertion portion 11 is not provided.
Further, a through hole 13 extending along the axis O is provided inside the tool body 10, and the inner diameter of the through hole 13 is lower than the through hole 13 on the tool body tip side (lower side in FIG. 1). An enlarged large diameter portion 14 is provided.
A tapered surface 15 is formed on the distal end side of the tool body 10 and gradually decreases in diameter toward the distal end side of the tool body. A reverse tapered surface 16 is formed on the taper surface 15 at the rear end side of the tool main body, and the diameter gradually increases as it goes toward the front end side of the tool main body.

A first tip pocket 17 having a bottom surface extending substantially parallel to the tapered surface 15 is formed on the tapered surface 15 by cutting the tool body 10 into an opening toward the distal end side of the tool body and the radially outer side of the tool body. A plurality (four in this embodiment, as shown in FIG. 2) are formed at equal intervals in the direction.
In addition, the tool tip 10 is notched on the reverse tapered surface 16, and the second tip pocket 18 having a bottom surface that opens toward the tip end side of the tool main body and the tool body radial direction and extends substantially parallel to the reverse tapered surface 16. However, a plurality (in this embodiment, four as shown in FIG. 2) are formed at equal intervals in the circumferential direction.
The first chip pocket 17 and the second chip pocket 18 have a cutting oil supply hole 19 having one end opened on the rear end surface of the tool body 10.

A first mounting seat 20 for mounting the insert 30 is provided behind the first tip pocket 17 in the tool rotation direction T. The wall surface on the rear end side of the tool body of the first mounting seat 20 is formed with the tapered surface 15. It is formed so as to be substantially parallel, and a clamp screw hole is formed in this wall surface.
Further, a second mounting seat 21 for mounting the insert 30 is provided behind the second tip pocket 18 in the tool rotation direction T, and the inner wall surface of the second mounting seat 21 in the radial direction of the tool body is reverse tapered. It is formed so as to be substantially parallel to the surface 16, and a clamp screw hole is formed in this wall surface.
The first mounting seats 20 and the second mounting seats 21 are alternately arranged in the circumferential direction as shown in FIG.

As shown in FIGS. 4 and 5, the insert 30 mounted on the first mounting seat 20 and the second mounting seat 21 is formed so that the outer shape is a substantially rectangular flat plate shape. The insert 30 includes two rectangular surfaces 31A, 31B and four side surfaces.
One of the four side faces is a rake face 32, and one of the other side faces connected to the rake face 32 is a flank face 33. As shown in FIG. 4, the side surface defined as the flank 33 and the side surface forming the rake surface 32 intersect at an acute angle, and the insert 30 is a positive insert 30 with a clearance angle.

The insert 30 has an insert main body 34 made of a hard material such as cemented carbide and a cutting edge portion 35 made of a material harder than the insert main body 34. A cutting edge portion 35 is disposed at a portion where the surface 33 intersects. In the present embodiment, the cutting edge portion 35 is made of a CBN (Cubic Boron Nitride) sintered body.
The cutting edge portion 35 has a plate shape, and is joined to the insert body 34 along the side surface forming the rake face 32.

The cutting blade portion 35 includes cutting blades 36A and 36B extending along intersecting ridge lines between the rectangular surfaces 31A and 31B and the rake surface 32, and a rake surface 32 and a relief surface 33 extending from the cutting blades 36A and 36B. Corner blades 37A and 37B connected to the cross ridge line portions, and linear cutting blades 38 formed on the cross ridge line portions extending between the corner blades 37A and 37B, and this insert 30 is a so-called vertical blade. The insert 30 is used.
In addition, a clamp screw insertion hole 39 is formed at the center of the quadrangular surfaces 31A and 31B so as to penetrate perpendicularly to the two quadrangular surfaces 31A and 31B.

  The clamp screw 40 is inserted into the clamp screw insertion hole 39 of the insert 30 and screwed into the clamp screw hole formed in the wall surface on the rear end side of the tool body of the first mounting seat 20, whereby the insert 30 is inserted into the first mounting seat. 20 is attached. At this time, the other quadrangular surface 31B of the insert 30 is brought into contact with the wall surface on the rear end side of the tool body, and the one quadrangular surface 31A is directed to the front end side of the tool body and is arranged substantially parallel to the tapered surface 15.

  In addition, the clamp screw 40 is inserted into the clamp screw insertion hole 39 of the insert 30 and screwed into the clamp screw hole formed in the wall surface on the inner side in the tool body radial direction of the second mounting seat 21, so that the insert 30 is second. Mounted on the mounting seat 21. At this time, one rectangular surface 31A of the insert 30 is brought into contact with the wall surface on the radially inner side of the tool body, and the other rectangular surface 31B is directed outward in the radial direction of the tool body so as to be arranged substantially parallel to the reverse tapered surface 16. .

The inserts 30 mounted on the first mounting seat 20 and the second mounting seat 21 in this way are arranged as shown in FIG. 3 when their rotation trajectories are superimposed.
The insert 30 mounted on the first mounting seat 20 has one corner blade 37A extending from the cutting edge 36A formed at the crossing ridge line portion of the one square surface 31A and the rake surface 32, and the tool body tip side and the tool body diameter. It is directed outward.
In addition, the insert 30 mounted on the second mounting seat 21 has the other corner blade 37B extending from the cutting edge 36B formed at the intersecting ridge line portion between the other square surface 31B and the rake surface 32, and the tool body tip side and the tool. It is directed outward in the main body radial direction.
Then, one corner blade 37A of the insert 30 mounted on the first mounting seat 20 has a tool body distal end side and a tool body radial inner side than the other corner blade 37B of the insert 30 mounted on the second mounting seat 21. It is located in.

  In the boring cutter 1 having the above-described configuration, the insertion portion 11 provided on the rear end side of the tool body is inserted into the attachment port of the adapter A, and the attachment bolt is inserted into the through hole 13 of the tool body 10 to be fixed to the adapter A. The At this time, the key material provided in the adapter A is inserted into the key groove 12 of the tool body 10, and the relative position in the circumferential direction between the adapter A and the tool body 10 is adjusted. The adapter A is provided with a cutting oil supply path for flowing cutting oil supplied from a machine tool (not shown) to the tip surface of the adapter A. The cutting oil supply path and the cutting oil supply hole of the tool body 10 are provided. 19 is arranged so as to communicate with 19.

  In this way, the adapter A to which the tool body 10 is fixed is attached to the spindle end of the machine tool, rotated at high speed around the axis O of the tool body 10, and fed in the direction of the axis O of the tool body 10. Thus, the tool body 10 is inserted into a prepared hole provided in the workpiece W in advance, and the cutting holes 36A, 36B and the corner blades 37A, 37B of the insert 30 mounted on the outer periphery of the tip end of the tool body 10 are used to form the prepared holes. The inner wall surface is cut to form a processed hole having a predetermined inner diameter. At the time of this cutting, cutting oil is supplied from the machine tool, and the cutting oil is supplied to the processing hole through the cutting oil supply path of the adapter A and the cutting oil supply hole 19 of the tool body 10.

In the boring cutter 1 having the above-described configuration, as shown in FIG. 3, one corner blade 37 </ b> A of the insert 30 mounted on the first mounting seat 20 is formed in the tool body more than the insert 30 mounted on the second mounting seat 20. The inner wall surface of the prepared hole provided in the workpiece W as a cutting edge for rough machining is cut with a cutting amount C1.
At the time of this roughing, one rectangular surface 31A is a front flank, the flank 33 is an outer flank, and one cutting edge 36A is arranged in parallel to the tapered surface 15, The outer peripheral flank is relieved from the inner wall surface so as to recede inwardly in the tool body radial direction as it goes toward the rear end side of the tool body. The other corner blade 37B and the other cutting edge 36B are not used for cutting. Moreover, cutting resistance during rough machining is suppressed.

  Next, the other corner blade 37B of the insert 30 mounted on the second mounting seat 21 is cut with the cutting amount C2 on the inner wall surface that has been roughly processed as a finishing cutting blade. The cut amount C2 is set to such a size that only the periphery of the other corner blade 37B is used for cutting, and the straight cutting blade 38 on the one side of the square surface 31A, the one corner blade 37A, and the one cutting blade 36A are used for cutting. It is never used. That is, the inserts 30 mounted on the first and second mounting seats 20 and 21 are configured so that the cutting blade portions used for cutting do not overlap each other.

At the time of finishing, the other rectangular surface 31B is an outer peripheral flank, the flank 33 is a front flank, and the other cutting edge 36B is disposed in parallel to the reverse tapered surface 16. The outer peripheral flank is relieved from the inner wall surface so as to recede inwardly in the radial direction of the tool body as it goes toward the rear end side of the tool body, and the cutting resistance during finishing is suppressed.
By cutting in this way, the cutting amount C of the entire boring cutter 1 is C1 + C2.

  In this boring cutter 1, since the cutting amount C of the entire boring cutter 1 is divided into C1 and C2, the cutting amounts of the inserts 30 mounted on the first mounting seat 20 and the second mounting seat 21 are C1 and C2, respectively. When the boring cutter 1 is protruded from the workpiece W, it is possible to prevent the machining hole opening from being lost. Further, after roughing with the insert 30 mounted on the first mounting seat 20, finishing is performed with the insert 30 mounted on the second mounting seat 21, so the insert mounted on the first mounting seat 20 that performs roughing Even when a small chipping occurs when 30 is protruded from the workpiece W, the chipping part can be removed by the insert 30 mounted on the second mounting seat 21 for finishing, so that a machined hole is formed with high accuracy. can do.

  Further, since the first mounting seat 20 and the second mounting seat 21 have different corner blades 37A and 37B directed toward the tool body radial direction outer side and the tool body front end side, the insert used by being mounted on the first mounting seat 20 30 can be used by being mounted on the second mounting seat 21. Conversely, the insert 30 used by being mounted on the second mounting seat 21 can also be used by mounting on the first mounting seat 20. Therefore, one set of inserts 30 can be mounted on the tool body 10 twice and used, and the cost of using the inserts 30 can be reduced.

  Moreover, since the said cutting blade part 35 is comprised with the CBN sintered compact, the abrasion resistance of the cutting blades 36A and 36B improves, and the lifetime of the insert 30 can be extended. Moreover, since only the cutting edge part 35 used for cutting is comprised by CBN, this insert 30 can be manufactured at low cost.

  Further, in the present embodiment, the first chip pocket 17 is formed on the tapered surface 15 and the second chip pocket 18 is formed on the reverse tapered surface 16, so that the portion where the tool body 10 is cut out may be concentrated. The rigidity of the tool body 10 is ensured. Therefore, chatter of the tool body 10 can be suppressed and the machining hole can be formed with high accuracy.

In this embodiment, the insert attached to the boring cutter has been described as a positive insert. However, the present invention is not limited to this. For example, as shown in FIG. May be.
Moreover, although the cutting edge part was demonstrated as an insert comprised with the CBN sintered compact, it is not limited to a material, For example, the cutting edge part may be comprised with the cemented carbide. However, it is preferable to use a CBN sintered body because the wear resistance is improved and the life of the insert can be extended.

  In addition, the first chip pocket is described as being provided with four circumferentially equal intervals, and the second chip pocket is provided with equal circumferential intervals in the circumferential direction. However, the present invention is not limited thereto. It is preferable that the number of mounting seats is appropriately arranged in consideration of the size of the workpiece.

It is side surface fragmentary sectional view of the boring cutter which is embodiment of this invention. It is a bottom view of the boring cutter shown in FIG. It is explanatory drawing which shows the state which cuts the inner wall surface of a pilot hole with the boring cutter shown in FIG. It is the figure which looked at the insert attached to the boring cutter shown in FIG. 1 from the square surface. FIG. 5 is a front view of FIG. 4. It is the figure which looked at the other insert attached to the boring cutter shown in FIG. 1 from the square surface.

Explanation of symbols

1 Boring cutter (cutting tool)
10 Tool body 20 First mounting seat 21 Second mounting seat 30 Insert 31A One quadrangular surface (polygonal surface)
31B The other quadrangular surface (polygonal surface)
32 Rake face 34 Insert body 35 Cutting edge portion 36A One cutting edge 36B The other cutting edge 37A One corner blade 37B The other corner blade 38 Straight cutting edge

Claims (3)

A cutting tool that has a tool body rotated around an axis and a plurality of inserts of the same shape and size, and is inserted into a pilot hole provided in advance in the workpiece, and cuts the inner wall surface of the pilot hole. There,
The insert has a polygonal flat plate shape and has two polygonal surfaces, and one of the side surfaces around the polygonal surface is a rake surface,
The insert has corner blades at corners formed by intersections of the rake face and the two polygonal faces and intersection ridge lines of the rake face and other side faces adjacent to the rake face. A cutting edge having,
On the outer periphery of the tip of the tool body, the insert is mounted with a first mounting seat mounted with one of the polygonal surfaces as a front flank, and a second mounted with the other polygonal surface as an outer flank. A mounting seat is provided,
In the inserts mounted on the first and second mounting seats, the corner blades on the opposite sides of the polygonal surface are directed outward in the tool main body radial direction. A cutting tool characterized in that a blade is disposed on the tip end side of the tool body and on the inner side in the tool body radial direction of the other corner blade. An insert attached to a cutting tool according to claim 1, wherein the insert is inserted into a prepared hole provided in advance in the workpiece, and the inner wall surface of the prepared hole is cut.
The insert body, which has a polygonal flat plate shape and has two polygonal surfaces, and one of the side surfaces around the polygonal surface is a rake face, has a plate shape that is harder than the insert body. The cutting edge is joined along the rake face,
A cutting blade having a corner blade at each corner formed by an intersection ridge line portion between the rake face and the two polygonal faces and an intersection ridge line portion between the rake face and another side surface adjacent to the rake face is provided. Insert characterized by being made.   The insert according to claim 2, wherein the cutting edge portion is made of CBN.

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