JP3180604B2 - Indexable inserts and indexable cutters - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throw-away type cutter mounted on a throw-away type cutter and suitable for cutting, and a throw-away type cutter equipped with the indexable type.

[0002]

2. Description of the Related Art Japanese Patent Publication No. 48-24462 discloses a throw-away cutter of this type, which is capable of producing a vine-like chip at the time of cutting and suitably discharging the same. This cutter will be described with reference to FIGS. The indexable insert 1 shown in FIG. 10 is formed in a substantially rectangular parallelepiped plate shape, and the ridge lines forming the sides where the upper surface 2 and the lower surface 3 intersect with the side surface 4 are the main cutting edges 5, respectively. Each corner is cut out and chamfered in the direction of the upper and lower surfaces, and each ridge line where the chamfered surface 6 intersects the upper and lower surfaces 2 and 3 constitutes the sub-cutting edge 7, respectively. Since the indexable insert 1 is of a negative type, the number of effective cutting edges is twice as large as that of a positive type insert.

[0003] Such a throw-away tip is shown in FIG.
When cutting is performed by mounting on a cutter 9 of a milling tool such as a milling cutter shown in FIG. 1, the tip 1 is mounted on the outer peripheral side of the tip of the cutter body 10 and the corner angle CH is set on the main cutting edge 5 located on the outer peripheral side. It is arranged so that the sub cutting edge 7 protrudes toward the front end side. In this case, in order for the chip discharge state to be in a helical shape and to be able to flow smoothly without damaging the processing surface or the like and to perform the discharge processing, the axial rake angle A, the radial rake angle R of the cutting blade, the cutting blade It is essential that the tilt angle I and the true rake angle T be set in predetermined ranges. According to the test results, the cutting edge inclination angle I was +5.
゜ It has been confirmed that vine-shaped chip discharge can be obtained only in the above limited range. Moreover, the cutting blade inclination angle I
Is a positive angle, the cutting angle can be established even when the combination of the radial rake angle R and the axial rake angle A is both a negative angle, both positive angles, and both positive and negative angles. (Equations (1) to (4)). This accounts for the possible angular range of the helical chip discharge.

That is, an axial rake angle A, a radial rake angle R, a cutting blade inclination angle I, a true rake angle T, and a corner angle C.
The relation of H is described by a calculation formula: tanT = tanR · cosCH + tanA · sinCH (1) tanI = tanA · cosCH−tanR · sinCH (2) tanA = tanI · cosCH + tanT · sinCH (3) tanR = tanT · cosCH−tanI · sinCH (4). The true rake angle T included in these formulas is important in cutting and mainly affects the cutting ability, but is usually used in the absolute value range of 0 to 20 °.

Further, considering the combination of the cutting edge angles for discharging the helical chips according to the above equation (2) on the condition that the negative indexable insert 1 having a large number of effective cutting edges is used, the cutting edge inclination angle I Is a positive angle, the axial rake angle A, and the radial rake angle R are both negative angles. That is, it is necessary that the radial rake angle R, the axial rake angle A, and the corner angle CH satisfy the condition of tanA · cosCH> tanR · sinCH (5). When the axial rake angle A is -4 °, the relationship between the true rake angle T, the cutting edge inclination angle I, and the corner angle CH is expressed by the following equation obtained from equations (2) and (4): tanI = tanA · secCH−tanT · FIG. 12 is a graph based on tanCH (6), and the practical effective range in which the chips are formed into a helical shape is that the cutting edge inclination angle I> 5 ° and the true rake angle T <| 20 ° | It is within the TI line. However, the true rake angle T is −5 ° to −20 as is clear from FIG.
Used in the range of ゜. FIG. 13 shows the relationship between the radial rake angle R, the axial rake angle A, and the corner angle CH within the effective range. That is, R =
Curve a below -20 ° is a combination of R and CH where I = 5 ° or more, and the upper curve is larger than T = −20 ° (that is, the value of the negative angle is smaller). The combination of the limit R and CH is shown, and the upper and lower curves a,
The area between "b" indicates the range of usable numerical values.

The axial rake angle A is the axial rake angle, that is, the clearance angle F of the front cutting edge portion, since a negative throw-away tip is used.
Used within the range of 10 °. Corner angle CH is usually 0
Although it is used in the range of ゜ 60 °, the corner angle CH in the present configuration is considered from Equation (6) or FIG. 12 assuming that the cutting edge inclination angle I is 5 ° or more and the axial rake angle A is −4 °. When the corner angle CH is 25 ° or less, the true rake angle T becomes a negative angle of −20 ° or less, resulting in poor sharpness and difficult cutting. If the corner angle CH is 60 ° or more, the corner angle CH can be used angularly. However, since the cut amount per chip size is reduced, it is generally 60 ° or less. Therefore, in practice, the axial rake angle A is -4 to -10.
コ ー ナ ー, corner angle CH is 25-60 °, cutting edge inclination angle I is +5
゜ When the cutting edge shape of the insert 1 is set in the above range and the cutter 1 is mounted on the cutter 9, cutting using a negative throw-away insert 1 to discharge vine-like chips causes the axial rake angle A and the radial rake angle R to be reduced. It is possible even if both are negative.

[0007]

However, with such a configuration, since the indexable insert 1 is a parallel plate negative type, when the inserter is mounted on the above-described cutter 9 and cut, the axial insert 1 is cut off axially. Rake angle A,
Since all of the true rake angles T are required to be negative, the chip discharge property and the sharpness were not always sufficient.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a throwaway chip that can further improve the chip discharge property and sharpness. It is another object of the present invention to provide a throw-away type cutter to which the throw-away tip is attached, whereby the chip discharge performance and the sharpness can be further improved.

[0009]

The indexable insert according to the present invention has a substantially polygonal shape, and has at least a main cutting edge and a sub cutting edge at a ridge line at which an upper surface and a side surface facing a lower surface forming a seating surface intersect. Ri formed provided, the cutter body tip outer periphery
To the main cutting edge located on the outer peripheral side
The negative indexable insert, which is arranged so that the sub cutting edge protrudes toward the tip end, is positioned on the outer peripheral side.
The main cutting edge from inclined to gradually approach the lower side in a direction away from the secondary cutting edge is arranged on the distal end side, <br/> been Is Curved above, the rake of the main cutting edge located on the outer peripheral side of with the surface is inclined so as to gradually approach the lower side in a direction away from the secondary cutting edge which is disposed at the distal end side along the longitudinal direction of the main cutting edge, the outer periphery
An inclined surface which is formed to be inclined so as to gradually approach the lower side in a direction intersecting the main cutting edge located on the side, further,
The rake angle of the rake face of the main cutting edge located on the outer peripheral side
Where α is the inclination along the longitudinal direction of the main cutting edge located on the outer peripheral side.
The inclination angle is set to β, and α> β . The rake face of the secondary cutting edge which is disposed at the distal end side, characterized in that it is formed so as to gradually approach the lower side in a direction intersecting with the minor cutting edge. Located on the outer circumference
That the rake face of the main cutting edge has substantially the same width over its entire length, the center side region following the rake face of the main cutting edge on the outer peripheral side
An inclined plane inclined in the same direction as the main cutting edge located may be formed. Also, the lower surface is configured to have the same shape as the upper surface. Further, the plurality of sub-cutting blades provided on the same surface are located on the same horizontal plane.

The indexable cutter according to the present invention comprises:
A throw-away tip is mounted so that the axial rake angle is -4 ° or less, the corner angle is 25 ° to 60 °, and the cutting edge inclination angle is 0 ° or more, and vine-like chips are generated during cutting. In the throw-away type cutter configured to discharge, the throw-away tip may be configured as follows.
Characterized in that it is a throw-away tip according to any one of the above. A throw-away tip is mounted so that the axial rake angle is -4 ° or less, the corner angle is 25 ° to 60 °, and the cutting edge inclination angle is 0 ° or more, and vine-like chips are generated during cutting. In the throw-away type cutter for discharging, the throw-away tip is the throw-away tip according to claim 4, wherein the tip mounting seat has an uneven shape on the surface (lower surface or upper surface) on the seating side of the throw away tip. It is mounted via a sheet having a corresponding upper surface shape.
The axial rake angle is preferably -4 ° to -10.
範 囲, more preferably -5 ゜ to -7 ゜. The true rake angle is preferably smaller than -5 °, in the range of -20 °, more preferably -10 ° to -1.
It is set within the range of 5 °. Then, a throw-away tip may be further mounted so as to satisfy the following expression: tanI = tanA · secCH−tanT · tanCH.

[0011]

According to the indexable insert of the present invention,
The rake face of the main cutting edge is inclined to the lower side in the direction away from the sub cutting edge along the longitudinal direction of the main cutting edge, so that a positive rake angle is formed in the axial direction, and chip discharge The rake angle is increased, and the sharpness is improved because the rake angle is increased because the rake angle is increased toward the lower surface side in a direction intersecting the main cutting edge. Moreover, since it is a negative type, the strength of the cutting blade is high. Also, be careful about the rake face of the main cutting edge.
Α> β, the inclination angle is relatively long
The inclination in the β direction is small, and the strength of the chip can be secured. The rake face of the sub cutting edge is formed so as to be gradually inclined toward the lower surface side in a direction intersecting with the sub cutting edge, so that the sharpness at the time of cutting is improved. Since the rake face of the main cutting edge has substantially the same width and the central area forms an inclined plane, the thickness of the indexable insert at the time of deep cutting can be ensured and its strength can be maintained. In addition, the number of effective cutting edges can be doubled as compared with the positive type, and the stamping can be easily performed. In addition, in the indexable insert, the dimensional accuracy can be easily controlled since each sub-cutting edge is located on the same plane.

According to the throw-away type cutter of the present invention, it is possible to generate and discharge a vine-shaped chip, and at that time, even if both the axial rake angle and the radial rake angle are negative. Yes, compared to the case of parallel-plated throw-away inserts, both the actual cutting blade inclination angle and the true rake angle can be made to be a regular angle. And sharpness improves. When the main cutting edge, the sub cutting edge, and the like are formed on the upper and lower surfaces of the throwaway tip, a sheet having an upper surface shape corresponding to the uneven shape of the surface on the seating side of the tip is provided on the tip mounting seat of the cutter. Since the tip is attached, the tip can be stably fixed and held without damaging the tip shape of the surface located on the seating side. Also, compared with the case where the parallel-plate-shaped insert insert is mounted under the same conditions, the substantial inclination angle of the cutting edge and the true rake angle can be made larger in the positive direction, for example, both can be made a regular angle. It can improve chip discharge and sharpness.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 is a perspective view of a throw-away tip according to an embodiment of the present invention, FIG. 2 is a front view, FIG. 3 is a plan view, FIG. 4 is a cross-sectional view taken along line VV of FIG. 3, and FIG. FIG. 6, FIG. 6 is a sectional view taken along line XX, FIG. 7 is a sectional view taken along line YY, and FIG. 8 is a sectional view taken along line ZZ. The throw-away tip 12 shown in FIGS. 1 and 2 has a substantially square plate shape, and a lower surface 13 serving as a seating surface is flat, and an upper surface 14 facing the lower surface 13 and a side surface between the upper and lower surfaces 13, 14. A ridge line forming each side intersecting with 15 is a main cutting edge 16, and a ridge line intersecting a chamfered surface 17 (supposed to be included in a side surface) obtained by chamfering each corner in the vertical direction and an upper surface 14 is a sub cutting edge. 18 is set. Each side surface 15 and chamfered surface 17 are orthogonal to the lower surface, and the throw-away tip 12 is of a negative type.

The sub-cutting blades 18 formed at each corner of the upper surface 14 are located on a virtual horizontal plane parallel to the lower surface 13 and have the same height. The boundary between the chamfered surface 17 and the side surfaces 15, 15 on both sides thereof is a flat chamfered surface 17 a, and each intersection ridge line between the chamfered surface 17 a and the upper surface 14 is a cutting edge 19, 19. In addition, chamfered surface 1
The cutting edge 7a and the cutting edge 19 may be omitted, but it is preferable that at least a portion between the sub cutting edge 18 and the main cutting edge 17 is provided to prevent loss. Further, the chamfered surface 17 may be an R-shaped curved surface. Each main cutting edge 16 has a lower surface 13 in a direction away from the sub cutting edge 18 along its longitudinal direction.
Is formed as an inclined ridge line gradually approaching to the side, and is curved upward in the vicinity of the sub-cutting edge 18 at an adjacent corner to form an adjacent sub-cutting edge 1.
8 is connected. In the center of the upper and lower surfaces 14, 13, a through hole 21 for screw clamping is formed.

On the upper surface 14, the rake face 22 of the main cutting edge 16 is formed to have substantially the same width in the longitudinal direction, and gradually approaches the lower surface side from the sub cutting edge 18 side in the longitudinal direction of the main cutting edge 16. (The distance to the lower surface 13 becomes shorter), and gradually approaches the lower surface side in the central direction (the direction of the through hole 21) away from the main cutting edge 16 (the distance to the lower surface 13 becomes shorter). (The rake angle α). The rake face 22 has a flat shape, is curved near the adjacent sub-cutting edge 18, is steeply inclined upward, and is connected to the adjacent sub-cutting edge 18. In this case, with respect to the direction of the rake angle α and the direction of the inclination angle β, the chip strength depends on the length of the direction (the β direction is longer than the α direction), so that α> β is set to maintain the strength. ing. The rake angle α is set to 10 to 30 ° (preferably 15 to 25 °). If α is smaller than 10 °, the sharpness is reduced. or,
Is between 5 ° and 20 ° (preferably between 10 ° and 15 °)
When β is smaller than 5 °, the chip discharge property decreases,
If the value exceeds ゜, the chip strength is reduced.

Rake surface 23 of sub-cutting edge 18 and cutting edge 19
a and 23b are inclined so as to gradually approach the lower surface side (the distance from the lower surface becomes smaller) in the center direction away from the respective cutting blades. Then, the through holes 21 in the rake face 22 of each main cutting edge 16
On the sides, inclined planes 24 which are inclined in parallel with the main cutting edge 16 and are horizontal in a direction orthogonal to the main cutting edge 16 are connected respectively (see FIGS. 6, 7, and 8). Moreover, a tapered inclined surface 25 concentric with the through hole 21 and cut out in a tapered shape is provided in a region between each inclined plane 24 and the through hole 21. A concave portion 26 is formed at the center of each of the rake faces 23a and 23b of the sub cutting edge 18 and the cutting edge 19, respectively. With the above-described configuration, a three-dimensional breaker is formed on the rake face 22 of the main cutting blade 16.

The throwaway tip 12 constructed as described above is mounted on the throwaway type cutter 9 shown in FIG. 11, and the same angle as that of the above-mentioned prior art, that is, the axial rake angle A is -4 to -10.゜, the corner angle CH is set to 25 to 60 °, and the cutting edge inclination angle I is set to the range of + 5 ° or more, so that the cutting edge angle of the insert 1 is set so as to satisfy the expression (6) tanI = tanA · secCH−tanT · tanCH Installing. Then, as for the cutting edge inclination angle I, since the main cutting edge 16 of the tip 12 has the inclination angle β, the substantial cutting edge inclination angle becomes large in the positive direction as (I + β), and the discharge property of the vine-shaped cutting chips increases. improves. As for the true rake angle T, since the rake face of the chip 12 has the rake angle α, the actual true rake angle is (T + α), which also increases in the positive direction, so that sharpness is improved. Will do. The selection of each numerical value makes it possible to make both the substantial cutting edge inclination angle and the true rake angle positive.

When the indexable insert 12 according to the present embodiment is mounted on the cutter 9, numerical examples of the angles are as follows: the axial rake angle A is -5 ゜ 03 ', and the radial rake angle R is -14 °. 46 ', corner angle CH is 44
{47 ′, true rake angle T is -14 °, and cutting edge inclination angle I is 7
It becomes ゜. In this case, the substantial cutting edge inclination angle I is (+ β
゜), the true rake angle further increases by (+ α ゜) toward the regular angle.

As described above, in the indexable insert 12 according to the present embodiment, the rake face α of the main cutting edge 16 increases the rake angle α to improve sharpness, and the chip angle discharge β increases the chip discharge. The performance is improved. In addition, since α> β is set for the rake face 22, the inclination in the direction of the inclination angle β having a relatively long dimension becomes small, and the strength of the chip can be secured. Further, by providing the inclined plane 24 at the center of the rake face 22, the chip thickness at the depth of cut can be ensured, and the chip strength can be maintained.
In addition, since the indexable insert 12 is of a negative type, there is an advantage that the embossing by a press becomes easy and the strength of the cutting edge can be maintained. Further, the throw-away type cutter according to the present embodiment does not need to change the mounting condition to the cutter 9 for discharging the vine-shaped chips as compared with the one provided with the parallel-plate-shaped throw-away tip ( (It may be changed.), The sharpness of the cutting blade 16 can be improved, and the vine-shaped chip discharge property can also be improved.

In the above embodiment, the upper and lower surfaces 14, 13 are used.
Although the cutting blades 16 and 18 are formed only on the upper surface 14 of the upper surface, as shown in the perspective view of FIG.
4, the indexable insert 27 having the main cutting edge 16, the rake face 22, the sub cutting edge 18 and the like may be formed. In this case, the number of effective cutting edges is twice that of the above-described embodiment. Become. Indexable tip 27 according to this embodiment
The main cutting edges 16 of the upper and lower surfaces 14 and 13 are formed substantially in parallel so that the main cutting edges 16 are at the same distance from each other at an arbitrary position. In this way, the indexable insert 27 having the main cutting edge 16 and the sub cutting edge 18 provided on the upper and lower surfaces 14 and 13 respectively has a plurality of sub cutting edges 1 on each surface on the same virtual plane.
Since 8 is located, there is also an advantage that dimensional accuracy control is easy. When the throw-away tip 27 is mounted on the tip mounting seat of the cutter 9 or the like, the upper surface is located between the tip mounting seat of the cutter 9 and the throw-away tip 27 (the lower surface 13). Alternatively, if a sheet having a surface shape corresponding to the uneven shape of the upper surface 14) is used, the chip 27 can be firmly mounted on the cutter 9 or the like without damaging the cutting blade or the like on the side not used for cutting. it can.

In addition, such a throw-away tip 1
When attaching the cutters 2 and 27 to the cutter 9 described above, the main cutting edge 16
The rake angle α and the inclination angle β are the same as those of the prior art, that is, the axial rake angle A is −4 to −10 °, the corner angle CH is 25 to 60 °, and the cutting edge inclination angle I is + 5 ° or more. Set the cutting edge angle of insert 1 in the range, and use equation (6) tan
Mounting so as to satisfy I = tanA · secCH−tanT · tanCH is not always necessary due to the features of the throwaway chips 12 and 27 according to the present embodiment.

Next, the indexable tip 1 of the present embodiment
The mounting conditions for mounting the chips 2 and 27 on the cutter 9 and improving the chip discharge property and sharpness will be described. That is, when the equation (2) is modified from the above-described Kronenberg calculation equation, the following equation (7) is obtained. tanR = (tanA.cosCH-tanI) .cosecCH (7) tanT = tanR.cosCH + tanA.sinCH (1) tanI = tanA.secCH-tanT.tanCH (6) tanR = tanT.cosCH-tanI.sinCH (4) and 13, the axial rake angle A and the value of the cutting edge inclination angle I or the true rake angle T are set to the conditions shown in Table 1 below, and the corner angle C is set.
Assuming that H = 25 °, 45 °, and 60 °, and substituting into the above equations (7), (1), (4), and (6), respectively, the radial rake angle R and the true rake angle T or The cutting blade inclination angle I is as shown in Table 1 below.

[0023]

In Table 1, when the axial rake angle A is -4 °, the cutting edge inclination angle I is + 5 °, and the corner angle CH is smaller than 25 °, the lower limit of the usable area shown in FIG. 13 is exceeded. This means that the true rake angle T is too small. Also, the axial rake angle A
Is −4 °, the true rake angle T is −20 °, and when the corner angle CH is greater than 60 °, the radial rake angle R is near the upper right limit of the usable area in FIG. Exceeds -20 °, it is too small.

By the way, according to the indexable inserts 12 and 27 of the above embodiment of the present invention, since the main cutting edge 16 is provided with a positive angle of the inclination angle β 角, the inclination angle I of the cutting edge is further negative. Can be set on the corner side. That is, from the above-described conventional technique, β + I = + 5 ° is sufficient, and the following equation (8) can be obtained. I = 5 ° −β (8) Then, when β = 5 ° is set, the cutting edge inclination angle I is 0 °, so that it is possible to discharge the tangled chips. Moreover,
If the cutting edge inclination angle I is increased toward the negative angle side, the amount of the negative angle of the true rake angle T which affects the sharpness can be reduced (Table 2).
reference).

[0026] However, as shown in the lower column of Table 2, when the cutting edge inclination angle I is set to a negative angle (for example, −4 °), the true rake angle T becomes too small, and the clearance angle on the outer peripheral side becomes insufficient. That is not desirable.

Therefore, although the cutting edge inclination angle I has a relationship with the axial rake angle A, in use, as shown in Table 3 below, it is preferable that A = −6 ° and around I = 0 °. You can say that.

In order to mount the throw-away chips 12 and 27 according to the embodiment of the present invention to the cutter 9 and discharge the vine-shaped chips, the corner angle CH is 25 to 60 ° and the cutting edge inclination angle I is 0 °. Within the above range, the axial rake angle A
Should be -4 ° or less, and preferably -4 ° to -10.
範 囲, more preferably -5 ゜ to -7 ゜. When the true rake angle T is 0 °, the outer peripheral escape is insufficient, but it may be set to an arbitrary negative angle (minus), preferably smaller than −5 ° and up to −20 °, more preferably −10 °. It is in the range of -15 °. In particular, if a numerical example of a practically effective mounting posture is shown, the corner angle C
When the axial rake angle A = -6 ° and the cutting edge inclination angle I = 4 ° near H = 45 °, the radial rake angle R =
−11.31 °, the true rake angle T = −12 ゜ 20 ′. Further, when the rake angle α = 25 ° and the inclination angle β of the main cutting edge 16 of the indexable inserts 12 and 27 are set to 10 °, the substantial cutting edge inclination angle I is about 14 ° and the true rake angle T is It is about 13 ゜.

In each of the above-described embodiments, the throw-away chips 12 and 27 have a substantially square plate shape. However, the present invention is not limited thereto. Substantially square plate shape, such as shape, or substantially triangular plate shape,
Needless to say, an appropriate polygonal shape can be used. Honing and flat lands may be provided on the main cutting edge 16, the sub cutting edge 18 and the like of the indexable inserts 12, 27.

[0030]

As described above, in the indexable insert according to the present invention, the main cutting edge is inclined so as to gradually approach the lower surface side in a direction away from the sub cutting edge, and is curved upward to be adjacent to the adjacent sub cutting edge. And the rake face of the main cutting edge is inclined so as to gradually approach the lower surface side in a direction away from the sub cutting edge along the longitudinal direction of the main cutting edge, and gradually decreases toward the lower surface side in a direction intersecting the main cutting edge. Since the inclined surface is formed so as to be inclined so as to approach, the inclined angle increases the chip dischargeability and increases the rake angle to improve sharpness. Moreover, since it is a negative type, the strength of the cutting blade is high. Also, for the rake face of the main cutting edge, α> β
The inclination in the direction of relatively large inclination angle β is small.
As a result, the strength of the chip can be secured. Further, the rake face of the sub cutting edge is formed so as to gradually approach the lower surface side in a direction intersecting with the sub cutting edge, so that the sharpness is improved. Also, the rake face of the main cutting edge has almost the same width over its entire length,
Since the central area following the rake face forms an inclined plane inclined in the same direction as the main cutting edge, the chip thickness at the time of deep cutting can be secured, and the chip strength can be maintained. Further, since the lower surface is formed in the same shape as the upper surface, embossing by a press becomes easy and the strength of the cutting blade can be maintained. or,
Since the plurality of sub-cutting blades provided on the same surface are located on the same horizontal plane, management of the processing accuracy of the indexable insert becomes easy. The throw-away type cutter according to the present invention is provided with a throw-away tip such that the axial rake angle is -4 ° or less, the corner angle is 25 ° to 60 °, and the cutting edge inclination angle is 0 ° or more. In a throw-away type cutter that generates and discharges a vine-shaped chip during cutting, the throw-away tip is the throw-away tip according to any one of claims 1 to 5, and thus has a parallel plate shape. Compared to a case where the indexable insert is mounted under the same conditions, the sharpness of the cutting blade can be improved and the discharge property of the vine-shaped chips can also be improved. Further, in the above-mentioned throw-away type cutter, which generates and discharges a vine-shaped chip at the time of cutting, the throw-away tip has a cutting edge formed on both upper and lower surfaces according to claim 4. Since the chip mounting seat is mounted via a sheet having an upper surface shape corresponding to the uneven shape of the surface on the seating side of the throw-away chip, the chip having cutting edges formed on both upper and lower surfaces is used. Also, it can be firmly mounted and fixed without damaging the cutting edge and the like on the seating side.

[Brief description of the drawings]

FIG. 1 is a perspective view of a throw-away tip according to an embodiment of the present invention.

FIG. 2 is a front view of the throw-away tip shown in FIG.

FIG. 3 is a plan view of the throw-away tip shown in FIG.

FIG. 4 is a cross-sectional view of the indexable insert shown in FIG.
It is a V line sectional view.

FIG. 5 is a sectional view taken along line WW of the throw-away tip shown in FIG. 3;

FIG. 6 is a sectional view taken along line XX of the throw-away tip shown in FIG. 3;

FIG. 7 is a sectional view taken along line YY of the throw-away tip shown in FIG. 3;

FIG. 8 is a sectional view taken along the line ZZ of the throw-away tip shown in FIG. 3;

FIG. 9 is another embodiment of a throw-away tip according to the present invention.

FIG. 10 is a perspective view of a conventional indexable tip.

11 is an explanatory view of a main part of a cutter to which the throw away tip shown in FIG. 10 is attached.

FIG. 12 is a diagram showing a relationship between a cutting edge inclination angle, a true rake angle, and a corner angle.

FIG. 13 is a diagram showing a relationship between a radial rake angle and a corner angle.

[Explanation of symbols]

 12, 27 indexable insert 13 lower surface 14 upper surface 16 main cutting edge 18 sub cutting edge 22 rake face of main cutting edge 23a rake face of sub cutting edge 24 inclined plane

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takanori Saito 1511 Furamagi, Ishishita-cho, Yuki-gun, Ibaraki Pref. Mitsubishi Materials Corporation Tsukuba Works JP-A-2-139104 (JP, A) JP-A-6-15517 (JP, A) JP-A-54-83085 (JP, U) JP-A-50-5981 (JP, U) JP-A-60-103610 (JP, A) , U) (58) Field surveyed (Int.Cl. ⁷ , DB name) B23C 5/06 B23B 27/16

Claims (7)

(57) [Claims] 1. A least, Ri formed by the main cutting edge and the secondary cutting edge is provided on a ridge line and upper and side surfaces opposed to the lower surface forming the seating surface intersect, it is attached to the tip outer peripheral side of the cutter body, the outer periphery
The main cutting edge located on the side has a corner angle, and the
In the negative indexable insert in which the cutting edge is arranged to protrude, the main cutting edge located on the outer peripheral side gradually approaches the lower surface side in a direction away from the sub cutting edge arranged on the distal end side. from the inclined to, are curved upward, the rake face of the main cutting edge located on the outer peripheral side, in the direction away from the secondary cutting edge disposed on the distal end side along the longitudinal direction of the main cutting edge While tilting gradually toward the lower surface,
An inclined surface is formed to be inclined so as to gradually approach the lower surface side in a direction intersecting the main cutting edge located on the outer peripheral side, and further, a rake surface of the main cutting edge located on the outer peripheral side is provided.
The rake angle is α, and the main cutting edge located on the outer peripheral side
A throw-away chip, wherein the inclination angle along the longitudinal direction is β, and α> β . Wherein the rake face of the secondary cutting edge disposed on the distal end side, according to claim 1, characterized in that it is formed so as to gradually approach the lower side in a direction intersecting with the minor cutting edge Throwaway tip. 3. The rake face of the main cutting edge located on the outer peripheral side has substantially the same width over its entire length, and the central area following the rake face is the same as the main cutting edge located on the outer peripheral side. The indexable tip according to claim 1 or 2, wherein the indexable tip forms an inclined plane inclined in the direction. 4. The indexable insert according to claim 1, wherein the lower surface has the same shape as the upper surface. 5. The indexable insert according to claim 1, wherein the plurality of sub-cutting blades provided on the same surface are located on the same horizontal plane. 6. A throw-away tip is mounted so that an axial rake angle is −4 ° or less, a corner angle is 25 ° to 60 °, and a cutting edge inclination angle is 0 ° or more, and a helical shape is formed at the time of cutting. A throw-away type cutter, which generates and discharges chips, wherein the throw-away tip is the throw-away tip according to any one of claims 1 to 5. 7. A throw-away tip is mounted so that an axial rake angle is −4 ° or less, a corner angle is 25 ° to 60 °, and a cutting edge inclination angle is 0 ° or more, and a helical shape is formed at the time of cutting. In a throw-away type cutter that generates and discharges chips, the throw-away tip is the throw-away tip according to claim 4, wherein a tip mounting seat has a surface on the seating side of the throw-away tip. A throw-away type cutter which is mounted via a sheet having an upper surface shape corresponding to the uneven shape.