JP2006095620A - Throw-away tip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a throw-away tip, decreasing the size of a chip to the utmost to prevent damage of a material to be cut and the tip itself, easily handling the chips, and stably performing cutting even if a part to be cut varies. <P>SOLUTION: A very hard cemented carbide sintered body 4 is joined to a mounting seat 3 formed on a tip corner part of at least one portion of a chip body 2, and a cutting edge 8 and a chip breaker 6 are formed on the very hard cemented carbide sintered body 4. The chip breaker 6 includes: first breaker walls 6b, 6b raised from the breaker base 6a; and a pair of second breaker walls 6d, 6d raised from the breaker base 6a and connected to the paired first breaker walls 6b, 6b. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a throw-away tip (hereinafter sometimes simply referred to as a tip) that is detachably attached to a tool body of a throw-away type cutting tool, in particular, a cutting edge portion of the tip body has cubic boron nitride. The present invention relates to an ultra-high hardness sintered body mainly composed of (CBN) or diamond, in which a chip breaker for chip disposal is formed.

In turning of hardened steel, etc., the above-mentioned ultra-high hardness sintered body is attached to the cutting edge portion of the chip body, and a chip breaker is formed on the upper surface portion of the ultra-high hardness sintered body connected to this cutting edge. Is known.
For example, the chip of Patent Document 1 below describes a chip breaker that includes a single breaker wall that is erected and formed with a certain radius of curvature r from the bottom surface of a breaker that is formed in a concave shape.

FIG. 3 shows a structure of a chip 101 described in Patent Document 1 below.
The chip body (polygon base metal) 102 is made of cemented carbide or the like, and an ultra-high hardness sintered body 104 is integrated with the mounting seat 103 formed at the tip corner portion of the chip body 102. The back plate 105 is joined by brazing.
In addition, the chip breaker 106 is formed at the corner of the tip of the ultra-high hardness sintered body 104.

  The chip breaker 106 has a breaker bottom surface 106a extending in the center direction of the chip 101 from the tip corner portion of the ultra-high hardness sintered body 104 and a recess having a radius of curvature r from the end of the breaker bottom surface 106a. A breaker wall 106b is formed to rise up to the upper surface 104a of the high hardness sintered body 104.

  Further, a chamfered portion 107 is formed at the intersection of each upper surface and side surface of the chip body 102 and the ultra-high hardness sintered body 104, and a part of the chamfered portion 107 on the tip corner portion side is cut. A blade edge chamfer 109 is formed along the blade 108. Reference numeral 110 denotes a center hole for chip attachment.

Under such a configuration, in the chip 101 described in Patent Document 1, the position and size of the chip breaker 106 and the cutting edge chamfer 109 are appropriately designed to achieve both the cutting edge strength and excellent chip disposal. I am trying.
JP-A-8-155702

However, in the chip 101 described in Patent Document 1, as described above, the breaker wall 106b is formed to rise from the end of the breaker bottom surface 106a with a radius of curvature of r, so that the upper end 106c of the breaker wall 106b and The distance (breaker width) from the cutting edge 108 inevitably increases.
Therefore, the size of the chip cannot be reduced, and the work piece or chip may be damaged by the chip, or the chip processing may be hindered.

  Moreover, in the chip | tip 101 of patent document 1, although only the single breaker wall 106b is formed, when actually cutting a workpiece, when cutting an outer diameter and cutting an end surface In some cases, the way in which the chip 101 and the workpiece are hit is slightly different. In other words, the way in which the breaker wall 106b and the chip are brought into contact differs depending on the part to be cut. There was a difficulty in realizing.

  The present invention has been made in view of the above problems, and can reduce the size of the chips as much as possible to prevent damage to the work piece and the chip itself, and can easily perform the chip processing, as well as the part to be cut. It is an object to provide a chip that can perform stable cutting even if the difference is different.

  In order to solve the above-described problems and achieve such an object, the throw-away tip according to claim 1 is made of a super-hard sintered material on a mounting seat formed in at least one tip corner portion of the tip body. In the throw-away tip with a chip breaker in which a cutting edge and a chip breaker are formed on the ultra-high hardness sintered body, the chip breaker is formed by standing upright from the bottom surface of the breaker and the bottom surface of the breaker. And at least one breaker wall.

According to the first aspect of the present invention, since the at least one breaker wall is erected substantially vertically from the bottom surface of the breaker, the breaker width is reduced.
Accordingly, the chips are bent before they become large, and are cut in contact with the work.

  The throw-away tip according to claim 2, wherein an ultra-high hardness sintered body is joined to a mounting seat formed at at least one tip corner portion of the tip body, and a cutting blade, a tip are attached to the ultra-high hardness sintered body. In the throw-away tip with a chip breaker in which a breaker is formed, the chip breaker is erected from the breaker bottom surface, a pair of first breaker walls formed upright from the breaker bottom surface, and the breaker bottom surface And a pair of second breaker walls formed continuously with the pair of first breaker walls.

  According to the second aspect of the present invention, the chip breaker includes the pair of first breaker walls and the pair of second breaker walls. It is bent in multiple stages by one or both of the breaker wall and the second breaker wall, and is cut in contact with the work.

  The throw-away tip according to claim 3, wherein at least one of the first breaker wall and the second breaker wall is formed so as to stand substantially vertically from the bottom surface of the breaker. is there.

  According to the third aspect of the invention, since the width of the breaker is reduced, the chips are bent before they are increased, and are cut in contact with the workpiece.

  The throw-away tip according to claim 4 is formed by extending the breaker bottom surface from the tip corner portion toward the center of the chip body in a top view as viewed from the direction facing the rake face of the chip body. The pair of first breaker walls has a first obtuse angle θ1 left and right across the bisector P with the upright portion on the bisector P of the apex angle of the tip corner as the breaker start point, The pair of second breaker walls are formed so as to extend outward in a substantially straight line, and the first breaker walls are arranged on the left and right sides of the first P from the respective ends of the pair of first breaker walls. It has a second obtuse angle θ2 larger than the obtuse angle θ1 and is outwardly extended in a substantially straight line.

  According to the fourth aspect of the present invention, by appropriately setting θ1 and θ2, even if the work site of the work is different, the contact between the chip and the chip breaker is made appropriate.

  The throw-away tip according to claim 5 is characterized in that a distance L1 from the tip of the bottom surface of the breaker on the bisector P to the breaker start point is 0.1 mm or more and 0.4 mm or less. Is.

  According to the fifth aspect of the present invention, since the breaker width is further reduced by selecting such a value as L1, the chips are bent before they become large and are cut in contact with the work.

  The throw-away tip according to claim 6 is located in a nose portion of the rake face parallel to a side forming the first breaker wall in a top view as viewed from a direction facing the rake face. The distance L2 to the line Q in contact with the substantially arcuate cutting edge ridge line is 0.1 mm or more and 0.4 mm or less.

  The throw away tip according to claim 7 is characterized in that a height H between an upper surface of the ultra-high hardness sintered body and a bottom surface of the breaker is 0.05 mm or more and 0.6 mm or less. Is.

  According to the inventions of these claims 6 and 7, even when the edge chamfered portion is formed to strengthen the cutting edge tip by setting the distance L2 and the height H to such a range, An effective portion as a chip breaker is secured, and the function as a chip breaker is exhibited.

According to the throw-away tip according to the present invention, the at least one breaker wall is formed to stand substantially vertically from the bottom surface of the breaker, so that the breaker width can be reduced.
Therefore, since the chips are bent by the chip breaker before they become large and are cut in contact with the work piece, damage to the work piece and the chip itself can be prevented, and chip treatment can be easily performed. Can do.

  Further, according to the throw-away tip according to the present invention, the chip breaker includes the first breaker wall and the second breaker wall, and chips are removed from the first breaker wall according to different work parts. It becomes possible to press or cut appropriately by one or both of the second breaker wall and the second breaker wall, and stable cutting can be performed.

Hereinafter, a throw-away tip according to the present invention will be described with reference to FIGS.
1 and 2 show an embodiment of the present invention. In a throw-away tip 1, a tip body (polygon base metal) 2 is formed of a cemented carbide or the like. Of the four corners of the rake face 2a, the super-hard sintered body 4 brazes the back plate 5 integral with the mounting seat 3 formed at one tip corner portion having an apex angle of 80 °. It is joined by attaching.
Further, the chip breaker 6 is formed at the corner of the tip of the ultra-high hardness sintered body 4.

  At the intersections between the upper surface and the side surfaces of the chip body 2 and the ultra-high hardness sintered body 4, a chamfered portion 7 that forms an angle α (25 ° in the present embodiment) with the rake face 2 a of the chip body 2. It is formed by honing, and a part of the chamfered portion 7 on the tip corner portion side is a cutting edge chamfered portion 9 along the cutting edge 8. Reference numeral 10 denotes a center hole for chip attachment.

The chip breaker 6 is a breaker that extends from the corner of the tip of the ultra-high hardness sintered body 4 toward the center of the chip 1 and is recessed in a top view as viewed from the direction facing the rake face 2 a of the chip body 2. A bottom surface 6a is provided.
In order to secure an effective portion as the chip breaker 6 so that the chips do not become large and even when the blade edge chamfered portion 9 is formed to strengthen the tip of the cutting blade 8 described later, The height H from the upper surface 4a of the ultra-high hardness sintered body 4 to the breaker bottom surface 6a is 0.05 mm or more and 0.6 mm or less.

On the bisector P of the apex angle of the tip end corner of the chip, the first obtuse angle θ1 on the left and right sides of the bisector P from the point L1 from the tip of the breaker bottom surface 6a outwards substantially linearly. A pair of first breaker walls 6b, 6b extending vertically is formed over the width W so as to stand substantially vertically from the breaker bottom surface 6a. The reason why the first breaker wall 6b, 6b is actually formed with a relatively large radius of curvature (about R200 in the present embodiment) is described as being substantially linear.
Reference numerals 6c and 6c denote upper end portions of the first breaker wall.

Here, [theta] 1 is in the range of 110 [deg.] To 130 [deg.] As a suitable angle when machining the end face of the workpiece (not shown).
Further, the width W of the first breaker wall is set to a range of 0.4 mm to 0.8 mm as a suitable dimension for appropriately bending and cutting chips generated from the work piece during processing.
Further, a distance from a line Q that is parallel to the side forming the first breaker wall and is in contact with the substantially arcuate cutting edge ridge line positioned at the nose portion of the rake face 2a of the chip body 2 so that the chips do not become large. L2 is 0.1 mm or more and 0.4 mm or less.

  Also, a pair of second breaker walls 6d extending outwardly in a substantially straight line with a second obtuse angle θ2 larger than the first obtuse angle θ1 from the respective ends of the pair of first breaker walls 6b, 6b. , 6d are formed so as to stand substantially vertically from the breaker bottom surface 6a. The reason why it is substantially linear is that the second breaker walls 6d, 6d are also formed with a radius of curvature of about R200, similarly to the first breaker walls 6b, 6b.

Here, (theta) 2 is made into the range of 140 degrees-152.5 degrees as an angle suitable when processing the outer diameter of the workpiece which is not shown in figure.
Note that the upper end portions 6e and 6e of the second breaker walls 6d and 6d are formed to be inclined forward and downward in the extending direction in order to reduce a load during processing, and are in contact with the chip body 2. In the vicinity of the side surface 4b of a certain ultra-high hardness sintered body 4, the height of the second breaker walls 6d, 6d is substantially zero.

In the case of machining the end face of, for example, a cylindrical workpiece with the tip of the present embodiment configured as described above, the tip end is usually brought into contact with the workpiece at a relative angle corresponding to θ1. .
Accordingly, the chips generated at this time are almost directly opposed to the first breaker wall 6b, and are pressed or cut by the first breaker wall 6b, so that the size of the chips is uniform and does not vary. Chip disposal is facilitated.

  Further, since the first breaker walls 6b, 6b are formed upright from the breaker bottom surface 6a, the width of the breaker can be reduced, and the chips generated by machining the end face of the work piece are Before it becomes large, it is bent by the first breaker wall 6b and is cut in contact with the work, so that damage to the work and the chip itself is prevented, and chip disposal is facilitated.

Further, when the outer diameter of a cylindrical workpiece is machined by the tip according to the present embodiment, the tip end is usually brought into contact with the part to be cut at a relative angle corresponding to θ2.
Accordingly, the chips generated at this time also face the second breaker wall 6d almost directly, and are pressed or cut by the second breaker wall 6d, so that the size of the chips does not vary and become uniform. Chip disposal is facilitated.

  Further, since the second breaker walls 6d, 6d are also formed so as to stand substantially vertically from the breaker bottom surface 6a, the width of the breaker can be reduced, and chips generated by machining the outer diameter of the workpiece. Is bent by the second breaker wall 6d before being increased, and is cut in contact with the work piece, so that damage to the work piece and the chip itself is prevented and chip disposal is facilitated.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist.

  For example, in the above-described embodiment, the chamfered portion 7 is formed by honing, but the chamfered portion 7 is not necessarily provided, and can be appropriately omitted in consideration of the strength of the blade edge. If the chamfered portion 7 can be omitted, the above-described breaker width can be further reduced, so that the chips are further reduced and the chip treatment can be facilitated.

  In the above-described embodiment, the tip corner portion of the rake face 2a in the chip body 2 has an apex angle of 80 ° in the top view. However, the present invention is not limited to this. The apex angle may be 35 °, 55 ° or 90 ° as viewed.

Further, in the above-described embodiment, the ultra-high hardness sintered body 4 is brazed to one tip corner portion having an apex angle of 80 ° among the four corners of the rake face 2a of the chip body 2; Although the chip breaker 6 is formed, a chip breaker having the same configuration can be provided at the other tip corner portion located on the diagonal line of the one tip corner portion.
Further, a chip breaker having a similar configuration can be provided on the bottom surface 2b side of the chip body 2.

It is a figure which shows the throw away tip of embodiment of this invention, Comprising: (a) is the whole perspective view of a throw away tip, (b) is the elements on larger scale of the part shown by X in (a). It is a figure which shows the chip breaker part of the throw away chip | tip of embodiment of this invention, Comprising: (a) is a top view, (b) is a front view. It is a figure which shows the conventional throwaway tip, Comprising: (a) is a whole perspective view, (b) is a top view which shows a chip breaker part, (c) is a front view which shows a chip breaker part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Throw away tip 2 Chip body 4 Super-hard sintered body 6 Chip breaker 6b First breaker wall 6d Second breaker wall P Bisecant of apex angle of tip corner portion Q Parallel to first breaker wall Line in contact with the substantially arcuate cutting edge ridge line L1 Distance from the tip of the bottom surface of the breaker to the first breaker wall L2 Distance between the first breaker wall and the tangent line H Height from the upper surface 4a to the breaker bottom surface 6a W First Breaker wall width θ1 Angle formed by first breaker wall and P θ2 Angle formed by second breaker wall and P

Claims (7)

A throwaway tip with a chip breaker in which an ultra-high hardness sintered body is joined to a mounting seat formed at at least one tip corner of the chip body, and a cutting blade and a chip breaker are formed on the ultra-high hardness sintered body. In
The tip breaker chip comprises a breaker bottom surface and at least one breaker wall formed upright substantially upright from the bottom surface of the breaker. A throwaway tip with a chip breaker in which an ultra-high hardness sintered body is joined to a mounting seat formed at at least one tip corner of the chip body, and a cutting blade and a chip breaker are formed on the ultra-high hardness sintered body. In
The chip breaker includes a breaker bottom surface,
A pair of first breaker walls formed upright from the bottom surface of the breaker;
A throw-away tip characterized by comprising a pair of second breaker walls standing from the bottom surface of the breaker and continuously formed on the pair of first breaker walls.   3. The throw-away tip according to claim 2, wherein at least one of the first breaker wall and the second breaker wall is erected substantially vertically from the bottom surface of the breaker. In top view as seen from the direction facing the rake face of the chip body,
The breaker bottom surface is formed extending from the tip corner portion toward the center of the chip body,
The pair of first breaker walls has a first obtuse angle θ1 on the left and right sides of the bisector P with the upright portion on the bisector P of the apex angle of the tip corner as the breaker start point. It is formed by extending outward in a straight line,
The pair of second breaker walls are substantially straight with a second obtuse angle θ2 larger than the first obtuse angle θ1 on both sides of the P from the respective ends of the pair of first breaker walls. The throwaway tip according to claim 2 or 3, wherein the throwaway tip is formed to extend outward in a shape.   The throw-away tip according to claim 3 or 4, wherein a distance L1 from the tip of the bottom surface of the breaker on the bisector P to the breaker start point is 0.1 mm or more and 0.4 mm or less. In top view as seen from the direction facing the rake face,
A distance L2 from a line Q parallel to the side forming the first breaker wall and in contact with the substantially arcuate cutting edge ridge located at the nose portion of the rake face is 0.1 mm or more and 0.4 mm or less. The throw-away tip according to claim 3, wherein the throw-away tip is provided. The throw away according to any one of claims 1 to 6, wherein a height H between an upper surface of the ultra-hard sintered body and a bottom surface of the breaker is 0.05 mm or more and 0.6 mm or less. Chip.

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