JP2006167875A - Insert for pin mirror cutter and pin mirror cutter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insert for a pin mirror cutter cutting resistance of which is never increased even when abrasion proceeds and the pin mirror cutter. <P>SOLUTION: Cutting blades 4d, 4e, 4f are respectively formed on crossing crest lines formed of a rake face 4a, a flank 4b and a flank 4c of the insert 4 making a flat plate shape and mounted on a peripheral surface and both side surface sides of an inner peripheral part 2a of a cutter body 2 making an annular shape of the pin mirror cutter 1, and the flank 4b and the flank 4c are formed in stepped shapes furnished with overhung parts 11, 11 formed in a direction separated from the cutting blades 4d, 4e, 4f and a drum part 12 retreated by one step from these overhung parts 11, 11. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an insert for a pin mirror cutter that processes a crankshaft or the like used in a reciprocating engine, and a pin mirror cutter provided with this insert.

As a tool for processing a crankshaft or the like of a reciprocating engine, a pin mirror cutter and an insert used therefor are known (see, for example, Patent Document 1).
FIG. 5 is a diagram showing the shape of a conventional insert 54 described in, for example, Patent Document 1, FIG. 5 (a) is a plan view, FIG. 5 (b) is a front view, and FIG. 5 (c) is a diagram. It is a Y direction arrow directional view of 5 (b).
The insert 54 has a rectangular flat plate shape in plan view integrally formed of cemented carbide, cermet, or the like, and a pair of peripheral surfaces along the long side of the rectangle has a parallelogram rake face. 54a is formed, and the other pair of peripheral surfaces along the short side and the opposing planes forming the rectangle are a flank 54b and a flank 54c, respectively, and the rake face 54a, the flank face 54b, and the flank face 54c A cutting edge is formed on each of the formed intersection ridge lines.
The cutting blade includes a first arcuate cutting edge 54d formed at a corner portion sandwiching an obtuse angle of the rake face 54a, a second arcuate cutting blade 54e formed at a corner portion sandwiching an acute angle, and the cutting blades. The linear cutting edge 54f formed in the ridgeline of the long side between 54d and the cutting edge 54e is provided.
An attachment hole 54g for screwing the insert 54 to the cutter body 52 is formed at the center between the opposing planes adjacent to the rake face 54a and the flank face 54b.

FIG. 6 is a view showing a state in which the above-described insert 54 is attached to the cutter body 52, and an attachment seat 55 for attaching the insert 54 is formed on the cutter body 52.
The mounting seat 55 is formed with a mounting surface 55a, a wall surface 55b that is vertically formed from the mounting surface 55a and faces one rake face 54a of the insert 54, and is adjacent to the wall surface 55b. A wall surface 55c is formed so as to rise vertically from 55a and face the relief surface 54b.
The insert 54 is positioned by the mounting surface 55a, the wall surface 55b, and the wall surface 55c of the mounting seat 55, and is detachably attached to the cutter body 52 by an attachment screw 56 inserted through the attachment hole 54g.

Further, the first arcuate cutting edge 54d and the second arcuate cutting edge 54e, which are located substantially diagonally from the intersecting line of the wall surface 55b and the wall surface 55c, are inward from the inner peripheral surface 52a of the cutter body 52. Are arranged so as to face a cutting surface of a workpiece (not shown).
Furthermore, a clearance angle is given to the flank 54b connected to the arcuate cutting blades 54d and 54e and the cutting blade 54f.
A chip pocket 52 b is formed adjacent to the mounting seat 55.
Japanese Patent Laid-Open No. 5-42409

However, in the insert 54 described in Patent Document 1, as shown as an example in FIG. 7 which is an enlarged view of the Q portion in FIG. 6, wear of the flank 54b of the insert 54 escapes to the flank 54b. Since the angle is given, as the cutting time is accumulated, it gradually proceeds obliquely with respect to the flank 54b.
Therefore, as the wear of the insert 54 progresses from the initial wear stage to the first wear level L51, the second wear level L52, and the third wear level L53, the second arcuate cutting edge 54e is not shown. The wear width of the surface facing the workpiece also gradually increases from a substantially zero state to the first wear width W51, the second wear width W52, and the third wear width W53.
For this reason, as the wear progresses, the contact area between the workpiece (not shown) and the second arcuate cutting edge 54e gradually increases, and the cutting resistance continues to increase.

  The present invention has been made in view of the above problems, and an object thereof is to provide an insert for a pin mirror cutter and a pin mirror cutter in which cutting resistance is not increased to a certain level or more even when wear progresses. .

In order to solve the above-described problems and achieve such an object, the insert for a pin mirror cutter according to claim 1 has a cutting edge formed at a cross ridge line between a rake face and a flank face of a flat insert. And is attached to the peripheral surface and both side surfaces of the inner peripheral portion or the outer peripheral portion of the cutter main body forming an annular shape of the pin mirror cutter,
The flank is characterized in that it is formed in a stepped shape having a step that retreats one step toward a direction away from the cutting edge.
Moreover, it is preferable that the width from the said cutting blade to the said level | step difference shall be 0.1 mm-3.0 mm (Claim 2).
Furthermore, it is preferable that the retraction amount of the flank at the step is 0.01 mm to 2.0 mm.
In addition, the pin mirror cutter according to claim 4 is provided with a gap between the insert according to any one of claims 1 to 3 on the peripheral surface and both side surfaces of the inner peripheral portion or the outer peripheral portion of the cutter body. It is characterized by being detachably attached in a staggered manner.

According to the insert for a pin mirror cutter according to the present invention, the flank has a step that retreats one step toward the direction away from the cutting edge while the stepped portion remains even if wear progresses. Since it has a stepped shape, the wear width of the flank can be made constant.
Therefore, an increase in the contact area between the work and the insert is suppressed, so that the cutting resistance does not increase beyond a certain level.
Also, if the width from the cutting edge to the step is too small, the stepped portion disappears immediately, and conversely if too large, the cutting resistance increases before the wear width of the flank becomes constant, The effect mentioned above can be show | played by making width into 0.1 mm to 3.0 mm.
Further, if the retraction amount of the flank at the step is too small, the stepped portion disappears immediately, and conversely if too large, the strength of the stepped portion is reduced. The effect mentioned above can be show | played by setting it as 0.0 mm.
Therefore, according to the pin mirror cutter according to the present invention in which such an insert is detachably attached, the cutting resistance does not increase beyond a certain level, and thus stable cutting can be performed.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 and 4.
FIG. 1 is a plan view for explaining the overall configuration of a pin mirror cutter 1 of the present embodiment (the half of one side is not shown). The pin mirror cutter 1 includes a cutter body 2 having a substantially annular shape, and the cutter body. 2 is fitted, and the adapter part 3 which makes the substantially annular shape fixed to the processing machine which is not shown in figure is provided.
Further, a plurality of chips 4 having cutting edges are arranged in a staggered manner on the inner peripheral portion of the cutter body 2 at intervals in the rotation direction on the peripheral surface and both side surfaces of the inner peripheral portion. These chips 4 are detachably attached to attachment seats 5 formed on the cutter body 2 by attachment bolts 6.

2A and 2B are views showing the shape of the insert 4 of the present embodiment, in which FIG. 2A is a plan view, FIG. 2B is a front view, and FIG. 2C is an X in FIG. 2B. FIG.
In this embodiment, the insert 4 has a rectangular flat plate shape in plan view integrally formed of cemented carbide, cermet or the like, and a pair of peripheral surfaces along the long side of the rectangle includes: A parallelogram-shaped rake face 4a is formed, and the other pair of peripheral surfaces along the short side and the opposing planes forming the rectangle are a flank face 4b and a flank face 4c, respectively. Cutting blades are formed on each of the intersecting ridge lines formed by 4b and the flank 4c.
This cutting edge includes a first arcuate cutting edge 4d formed at a corner portion sandwiching an obtuse angle of the rake face 4a, a second arcuate cutting blade 4e formed at a corner portion sandwiching an acute angle, and these arcuate shapes. A straight cutting edge 4f formed on the ridge line on the long side between the cutting edge 4d and the arcuate cutting edge 4e is provided.
A mounting hole 4g for screwing the insert 4 to the cutter body 2 is formed in the center between the opposing planes adjacent to the rake face 4a and the flank face 4b.

In the present embodiment, the flank 4b and the flank 4c are connected to the above-described cutting edges 4d to 4f formed at the ridges of the rake face 4a, and are separated from the cutting edges 4d to 4f. Are formed in a stepped shape including a projecting portion 11, 11 having a width A, and a body portion 12 that is retracted one step from the projecting portion 11, 11 by a retraction amount B.
Here, the width A may be appropriately set between 0.1 mm and 3.0 mm, but in this embodiment, it is constant at 0.3 mm.
Further, the retraction amount B may be appropriately set between 0.01 mm and 2.0 mm, but in this embodiment, it is constant at 0.1 mm.
The outer peripheral surfaces of the overhang portions 11 and 11 and the body portion 12 are formed perpendicular to the rake face 4a, and the step between the overhang portions 11 and 11 and the body portion 12 is formed in parallel to the rake face 4a. .
Therefore, the insert 4 of the present embodiment is a negative type.

FIG. 3 is a view showing a state in which the above-described insert 4 is attached to the cutter body 2, and an attachment seat 5 for attaching the insert 4 is formed on the cutter body 2.
The mounting seat 5 is provided with a mounting surface 5a, a wall surface 5b which is vertically formed from the mounting surface 5a and faces one rake face 4a of the insert 4, and is adjacent to the wall surface 5b. And a wall surface 5c that is vertically formed from 5a and faces the flank 4b.
The insert 4 is positioned by the mounting surface 5a, the wall surface 5b, and the wall surface 5c of the mounting seat 5, and is detachably attached to the cutter body 2 by the attachment screw 6 inserted through the attachment hole 4g.

Further, the first arcuate cutting edge 4d and the second arcuate cutting edge 4e, which are located substantially diagonally from the intersecting line of the wall surface 5b and the wall surface 5c, are inward from the inner peripheral surface 2a of the cutter body 2. Are arranged so as to face a cutting surface of a workpiece (not shown).
Furthermore, a clearance angle is given to the flank 4b connected to the arcuate cutting edges 4d and 4e and the cutting edge 4f.
Further, a chip pocket 2 b is formed adjacent to the mounting seat 5.

When the pin mirror cutter 1 configured as described above is used for cutting a workpiece (not shown), the wear of the flank 4b of the insert 4 is given a clearance angle to the flank 4b. As the cutting time is accumulated, it gradually proceeds obliquely with respect to the flank 4b.
The state of this wear will be described by way of example with reference to FIG. 4 which is an enlarged view of the P portion of FIG. 3. The wear of the insert 4 is the first wear level L1 and the second wear level L2 from the initial wear stage. And it progresses with the 3rd wear level L3.
At this time, the wear width of the surface of the second arcuate cutting edge 4e facing the workpiece (not shown) is the wear width in the process from the first wear level L1 to the second wear level L2 after the initial wear. The intersection of the surface and the overhanging portion 11 does not reach the end of the width A, and gradually increases from the first wear width W1 to the second wear width W2.

However, when reaching from the second wear level L2 to the third wear level L3, the amount of retraction B is between the point where the wear surface and the overhanging portion 11 cross the end of the width A and reach the body portion 12. Due to the presence, the second wear width W2 and the third wear width W3 are maintained at substantially constant values.
Thereby, the contact area between the workpiece (not shown) and the second arcuate cutting edge 4e is also maintained substantially constant during the period from the second wear level L2 to the third wear level L3. The cutting resistance does not increase.

According to the present embodiment, even if wear progresses, the flank 4b has a stepped shape having the protruding portion 11 that retreats one step toward the direction away from the cutting edge. While the slag remains, the wear width of the flank 4b can be made constant.
Therefore, since the increase in the contact area between the workpiece and the insert 4 is suppressed while the overhanging portion 11 remains, the cutting resistance does not increase beyond a certain level.
If the width A of the overhanging portion 11 is too small, the overhanging portion 11 disappears immediately. Conversely, if the width A of the overhanging portion 11 is too large, from the initial wear to the second wear level L2. In this embodiment, since the width A is set to 0.3 mm, an increase in the cutting resistance can be appropriately suppressed.
Further, if the retraction amount B from the overhanging portion 11 to the body portion 12 is too small, the overhanging portion 11 disappears immediately. Conversely, if the retraction amount B is too large, the strength of the overhanging portion 11 is reduced. In this embodiment, since the retraction amount B is set to 0.1 mm, an increase in cutting resistance can be appropriately suppressed.

Furthermore, if the retraction amount B is too large with respect to the width A, the strength of the overhanging portion 11 is reduced. However, according to the present embodiment, the ratio of the width A and the retraction amount B is set to 3: 1. Therefore, the strength of the overhanging portion 11 can be ensured appropriately.
Therefore, according to the pin mirror cutter 1 according to the present invention in which such an insert 4 is detachably attached, the cutting resistance does not increase beyond a certain level, and thus stable cutting can be performed.

The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist.
Specifically, in the above-described embodiment, the overhanging portion 11 is formed at two places on the insert 4, but it is sufficient to provide at least one place.
Further, in the embodiment described above, the internal type pin mirror cutter 1 in which the inserts 4 are disposed on the peripheral surface and both side surfaces of the inner peripheral portion of the cutter body 2 has been described. The present invention can also be applied to an external pin mirror cutter in which inserts 4 are disposed on the peripheral surface and both side surfaces of the outer peripheral portion of the main body 2.

  It is possible to provide an insert for a pin mirror cutter and a pin mirror cutter in which cutting resistance is not increased beyond a certain level even when wear progresses.

It is a top view explaining the whole structure of the pin mirror cutter 1 of embodiment of this invention. It is a figure which shows the shape of the insert 4 of embodiment of this invention, (a) is a top view, (b) is a front view, (c) is a X direction arrow directional view of (b). It is a figure which shows a mode that the insert 4 of embodiment of this invention is attached to the cutter main body 2, Comprising: (a) is a perspective view, (b) is a front view of (a). It is a principal part enlarged view which shows the mode of progress of abrasion in the P section in FIG.3 (b). It is a figure which shows the shape of the conventional insert 54, (a) is a top view, (b) is a front view, (c) is a Y direction arrow directional view of (b). It is a figure which shows a mode that the conventional insert 54 is attached to the cutter main body 52, Comprising: (a) is a perspective view, (b) is a front view of (a). It is a principal part enlarged view which shows the mode of progress of abrasion in the Q section in FIG.3 (b).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pin mirror cutter 4 Insert 4a Rake face 4b, 4c Flank 4d 1st arcuate cutting edge 4e 2nd arcuate cutting edge 5 Mounting seat 11 Overhang part 12 Trunk part A Width of overhang part 11 B Bump of trunk part 12 Retraction amount L1, L2, L3 First to third wear levels W1, W2, W3 First to third wear widths

Claims (4)

A cutting edge is formed at the intersecting ridge line between the rake face and flank face of the insert that forms a flat plate shape, and it is detachable on the inner peripheral part or outer peripheral part of the annular body of the pin mirror cutter or on both sides. An insert for a pin mirror cutter attached to
The insert for a pin mirror cutter, wherein the flank surface is formed in a stepped shape having a step that retreats one step toward a direction away from the cutting edge.   The pin mirror cutter insert according to claim 1, wherein a width from the cutting edge to the step is 0.1 mm to 3.0 mm.   The insert for a pin mirror cutter according to claim 1 or 2, wherein a retraction amount of the flank at the step is 0.01 mm to 2.0 mm. The insert according to any one of claims 1 to 3 is detachably attached in a zigzag manner at intervals on the inner peripheral portion or the outer peripheral portion of the cutter body that forms an annular shape and on both sides. Pin mirror cutter characterized by.

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