JPH09207007A - Throw-away chip with honing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an increased life for a chip by dispersing an impact load during chamfering. SOLUTION: Honing 19 is formed on the cutting edge ridge line part of a throw-away chip 10. A honing angle α a in the region of a main cutting edge 13 is gradually increased from a connection region to a corner blade 14 to a connection region to an auxiliary cutting edge 15 to form a honing twist surface 19a. A honing width Ta is gradually decreased along the main cutting edge 13 and the main cutting edge 13 is positioned parallel to an under surface 11. In a case of an axial rake angle B being positive during chamfering that the chip 10 is attached to a cutting tool, contact is effected at the point S1 on a cross ridge line L1 between a cutting face 12 and a honing twist surface 19a. In a case of the axial angle B being negative, contact is effected at a point R1 .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throw-away tip mounted on various cutting tools such as face milling cutters, end mills and cutting tools.

[0002]

2. Description of the Related Art Conventionally, for example, when a work material is cut using a throw-away type face mill, as shown in FIG. 18, a throw-away tip is provided on the outer periphery of the tip of a cutter body 1a of the face mill 1. 2 is mounted, the main cutting edge 3 is located on the outer peripheral side, and the sub cutting edge 4 is located on the outer peripheral side at the tip. Then, by rotationally cutting the cutter body 1 with respect to the work material 5, the part 5a of the work material 5 is intermittently scraped off. In the case of cutting, the impact is great especially when the cutting edges 3 and 4 of the throw-away tip 2 start to hit the work material 5, and the impact is likely to cause the cutting edges 3 and 4 to be damaged. Is important for prolonging the life of the throw-away tip 2. In FIG. 18, what is considered as the first contact point between the throw-away tip 2 of the face mill 1 and the work material 5 at the time of biting is R, S,
There are four points, U and V. In relation to these four points, as a point, as a line (between S-R, S-V, R-U or U-V) or as a plane (S-R-U-V), the throw-away tip 2 and Initial contact with the work material 5 is made.

[0003]

However, when the throw-away tip 2 and the work material 5 are initially contacted with each other on a line or a surface, the impact load and the cutting resistance during cutting are too large, which is not preferable. Further, when the initial contact is made at the points (S, R, U, V), if the contact is made at the points U and V, the main cutting edge 3 has a large impact and the life of the cutting edge is short. Therefore, as shown by point S or point R, the first contact is made inside the rake face of the cutting edge, which is a point closer to the axis of rotation of the main cutting edge 3, and then the main cutting edge 3 contacts the work material 5. Then, it is preferable that cutting is performed. In order for the throw-away tip 2 to make such a contact with the work material 5, there arises a problem that the mounting posture of the tip with respect to the cutting tool is limited and the sharpness becomes poor.

In view of such a situation, the present invention disperses the impact load applied to the throw-away tip without impairing the sharpness at the time of biting, regardless of the mounting posture to the cutting tool, and thus the cutting edge life. It is an object of the present invention to provide a throw-away tip capable of improving the above.

[0005]

A throw-away tip according to the present invention is a throw-away tip in which a honing surface is formed on a cutting edge, and the honing surface is honing from one end side to the other end side of the cutting edge. It is characterized in that it is formed in a twisted surface shape whose angle gradually changes. When the work material is cut with the throw-away tip attached to the cutting tool with one end of the cutting edge positioned at the tip end and the other end at the base end, the honing surface becomes twisted. Since the cutting edge does not come into direct contact with the work material when biting, it is possible to make point contact on the ridge line that intersects the rake surface inside the cutting edge of the cutting edge and the honing surface. Since it will contact with and cut, the impact time of the chip when biting is long,
Since the impact load can be dispersed on the rake face, chipping of the cutting edge does not occur easily and the tool life is long. The honing angle of the honing surface is gradually increased or decreased from the tip side toward the base side according to the mounting posture on the cutting tool, and the tip side has good sharpness when biting and the base side. It is better to increase the cutting edge strength.

Further, a cutting edge forming an intersecting ridgeline between the honing surface and the flank may be inclined from one end side to the other end side so as to gradually approach the seating surface facing the rake surface.
Thereby, the angle of the cutting edge can be adjusted without changing the mounting posture of the tip, and the sharpness and the cutting edge strength can be balanced according to the cutting depth.
Further, a cutting edge forming an intersecting ridgeline between the honing surface and the flank may be formed parallel to the seating surface facing the rake surface. Also, the width of the honing surface is set to be equal to the longitudinal direction of the cutting edge in a plan view. Further, the width of the honing surface may gradually change from one end side to the other end side along the longitudinal direction of the cutting edge in a plan view. by this,
The impact time when biting can be changed according to the mounting posture (radial position of the contact point), and the impact load can be further dispersed.

The throw-away tip is provided with a sub-cutting edge, and the sub-cutting edge is formed with a honing surface having a constant honing angle and a constant width in plan view along the longitudinal direction thereof. The auxiliary cutting edge has a constant honing angle and a constant width, so that good finishing cutting can be performed.
In the throw away tip according to the present invention, a honing surface is formed by a press die at the time of molding the tip and is used as a sintered surface.

In the cutting tool according to the present invention, the throw-away tip has an axial rake angle (back rake).
The cutting edge is attached so that the cutting edge is located outside the tip, and the honing angle of the honing surface of the tip is positioned so as to gradually increase from the tip side toward the base side. As a result, the tip is positioned in the direction of the core gradually descending (equal angle) from the tip side of the cutting edge toward the base side, so that the tip side is relatively sharp and the honing angle increases at the base side. In addition, it is possible to suppress deterioration of sharpness and improve cutting edge strength. Further, in the cutting tool according to the present invention, the throw-away tip is mounted so that the cutting edge is located outside the tip end with the axial rake angle (back rake) being negative, and the honing angle of the honing surface is based on the tip side. It is located so as to become gradually smaller toward the end side. As a result, the tip is positioned in the direction of gradually increasing the core (negative angle) from the tip side to the base side of the cutting edge, so the honing angle is large on the tip side, but the radial rake (lateral rake angle) is positive. Since it is large in the direction, the cutting edge strength is relatively high and the cutting edge strength is high, and the honing angle gradually decreases on the base end side. Therefore, even if the radial rake (lateral rake angle) becomes small, it is possible to suppress the reduction of the cutting edge.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described below with reference to FIGS. 1 to 5. The same parts as those of the above-mentioned prior art are designated by the same reference numerals and the description thereof is omitted. .
FIG. 1 relates to a throw-away tip according to the first embodiment, (a) is a plan view, (b) is a side view, and FIG.
(A) is A1 of the throw-away tip shown in FIG. 1 (a).
-A1 line sectional view, (b) is a B1-B1 line sectional view, (c)
Is a sectional view taken along the line C1-C1, FIG. 3 is a partially cutaway front view showing a state in which the throw-away tip shown in FIG. 1 is mounted on a front milling cutter, FIG. 4 is a side view of the front milling cutter of FIG. 3, and FIG. FIG. 3 is a bottom view of the front milling machine of FIG. In FIG. 1, the throw-away tip 10 according to the present embodiment has, for example, a substantially quadrangular (substantially square in the figure) plate shape, and has a lower surface 11 that forms a seating surface and an upper surface 12 that faces the seating surface. Upper surface 1
A main cutting edge 13 is formed on each of the ridges that form the four sides of the circle 2, and an arcuate corner blade 14 is provided on each corner. Two adjacent main cutting edges 13 are substantially orthogonal to each other.

Then, between the main cutting edge 13 and one of the corner cutting edges 14 on each ridge side, a small angle (for example, 1 to 5 degrees) with respect to the main cutting edge 13 is provided inside the upper surface 12. An inclined auxiliary cutting edge (cleaning blade) 15 is formed, and the auxiliary cutting edge 15 is smoothly connected to the corner blade 14. Four circumferential side surfaces 18 between the lower surface 11 and the upper surface 12
As shown in FIG. 1 (b), is inclined outward from the lower surface 11 toward the upper surface 12 to form a positive chip. The upper surface 12 is a rake surface and the side surface 18 is a flank. Further, an insertion hole 16 for inserting a screw is formed through the central portions of the upper surface 12 and the lower surface 11.
In FIG. 1A, honing (honing surface) 19 is provided over the entire circumference of a ridge line portion (main cutting edge 13, sub-cutting edge 15, corner blade 14) forming four rounds of upper surface 12. That is, the intersecting ridge line portion between the honing 19 and the side surface 18 is the main cutting edge 13, the sub cutting edge 15, and the corner blade 14. Further, the honing 19 has a straight cross section orthogonal to the ridge.

Moreover, the honing 19 in the region of the main cutting edge 13 forming each ridge is shown in FIGS. 2 (a), 2 (b),
As shown in the sectional view of (c), the corner blade 14 on one end side
Inclination angle (referred to as honing angle) with respect to the upper surface 12 from the connection region with the connection region with the secondary cutting edge 15 on the other end side.
αa is αa1, αa2, αa3 (αa1 <αa2 <α
a3) so as to increase gradually with honing twist surface 19
a. Moreover, the width Ta of the honing twisted surface 19a in a plan view is from the connection region with the corner blade 14 on the one end side to the connection region with the sub cutting blade 15 on the other end along the longitudinal direction of the main cutting blade 13. Towards Ta
1, Ta2, Ta3 (Ta1>Ta2> Ta3). The width Wa of the honing 19 in a side view, that is, the distance from the upper surface 12 to the main cutting edge 13 in the direction orthogonal to the upper surface 12 is constant over the entire length in the longitudinal direction. Therefore, the main cutting edge 13 is substantially parallel to the lower surface 11.

The honing angle αa is set in the range of 5 ° to 50 °, preferably 15 ° to 30 °. If the honing angle αa is less than 5 °, it becomes difficult to perform honing, and if it exceeds 50 °, the cutting edge (1
The sharpness of 3, 14, 15) becomes poor. In addition, the honing width Ta is as shown in FIG.
Although it is exaggeratedly shown to be large with respect to the dimension of, the width Ta is set in the range of 0.5 to 0.05 mm. Here, if the honing width Ta is larger than 0.5 mm, the sharpness of the cutting edge becomes poor, and if it is less than 0.05 mm, chipping of the cutting edge is likely to occur. Further, since the honing 19b in the region of the sub cutting edge 15 is subjected to finish cutting by the sub cutting edge 15,
Constant honing angle αa4, constant honing width Ta
It is set to 4. Moreover, these αa4 and Ta4 are used for the honing 1 in the connection region of the main cutting edge 13 and the sub cutting edge 15.
The minimum honing angle αa and the minimum honing width Ta of 9a are equal to each other, and each honing 19a, 19b is smoothly connected.

The throw-away tip 10 according to the present embodiment is constructed as described above, and the throw-away tip 10 has the auxiliary cutting edge 15 located on the outer side of the tip as shown in, for example, FIGS. A case will be described in which the main cutting edge 13 is mounted on the cutter body 22 of the front milling cutter 21 so that the main cutting edge 13 is located on the outer peripheral side. Then, the throw-away tip 10 has a positive axial rake angle β, for example,
It is assumed that the radial rake angle γ is set to negative. In this case, the tip 10 is mounted so that the honing angle αa gradually increases from the distal end side toward the proximal end side. When rotating the work material with the face mill 21 to which the throw-away tip 10 is attached, the part of the throw-away tip 10 that comes into contact with the work material when biting is the honing 19
Main cutting edge 1 that is mainly cut because of the cutting
It is not the region of 3 but the region on the ridge line L1 where the honing 19 and the rake face 12 intersect. Moreover, since the axial rake angle β is positive, the contact is made at the point S1 on the auxiliary cutting edge 15 on the tip side of the intersecting ridge line L1 (see FIG. 1A).

Then, by further rotating, the area of the main cutting edge 13 comes into contact with the work material with a delay, and the main cutting is performed. Moreover, the main cutting edge 13 of the throw-away tip 10 has relatively good sharpness because the honing angle αa is the smallest on the tip side. Then, since the honing angle αa gradually increases from the tip end side toward the base end side, the strength of the cutting edge gradually increases and the chipping during deep cutting is unlikely to occur. In addition, since the axial rake angle β is positive, the radial rake angle γ of the main cutting edge 13 gradually increases in the positive direction (center down) in the base end side region, so that deterioration in sharpness can be suppressed.

Further, the mounting posture of the throw-away tip 10 with respect to the front milling cutter 21 is not limited to the one described above. For example, even if both the axial rake angle β and the radial rake angle γ are positive, the honing angle αa
If is larger than the value of γ, it is possible to make contact at the point S1 on the rake face 12 of the throw-away tip 10 at the time of biting, as in the case described above. When the axial rake angle β is negative, the throw-away tip 10
The change in the honing angle αa along the main cutting edge 13 of the honing 19 may be reversed from that shown in FIGS. 1 and 2. That is, the honing angle αa along the main cutting edge 13 of the honing 19a is set to gradually decrease from the connection area with the corner cutting edge 14 on the one end side toward the connection area with the sub cutting edge 15 on the other end side. When the radial rake angle γ is negative, the rake face 12 contacts the work material at a point R1 (see FIG. 1 (A)) on the base end side on the ridge line L1 intersecting with the honing 19 at the time of biting. Become. In this case, the height of the point R1 on the intersecting ridge line L1 is determined by the depth of the cut in the work material. Also, the radial rake angle γ
In the case of positive, if the honing angle αa is made larger than the value of γ, the point R1 on the base end side on the ridge line L1 intersecting with the honing 19 of the rake face 12 at the time of biting (Fig. 1 (see (A)) will come into contact with the work material. When the axial rake angle β is negative, the main cutting edge 13 is relatively sharp on the tip side, and the radial rake angle γ gradually increases on the base side in the negative direction, but the honing angle α
Since a is gradually decreased, it is possible to suppress deterioration of sharpness.

As described above, according to the present embodiment, a point on the intersection region L1 with the honing twist surface 19a on the rake face 12 of the throw-away tip 10 at the time of biting regardless of the mounting posture on the cutting tool. The work piece can be brought into contact with S1 or R1 and then come into contact with the cutting edge 13 etc., so that the cutting edge first comes into contact with the work piece when biting like a conventional cutting tool of this kind. Therefore, the impact time at the time of biting can be taken longer, the impact load can be dispersed, the damage of the cutting edge 13 and the like can be suppressed, and the life of the throw-away tip 10 can be greatly improved. Further, in the region of the sub cutting edge 15, the honing 19b has the same honing angle αa and the width T, so that excellent finishing cutting can be performed.

Next, a second embodiment of the present invention will be described with reference to FIGS. 6 and 7. The same parts or members as those in the above-mentioned embodiment will be designated by the same reference numerals and the description thereof will be omitted. . In the throw-away tip 24 shown in FIGS. 6 and 7, the honing 25 formed on the ridgeline portion (cutting edges 13, 14, 15) of the upper surface 12 has the same width Tb in plan view over the entire circumference, and the honing is performed. In the area of the main cutting edge 13, the angle αb is along the main cutting edge 13 and the corner blade 14 on one end side.
It is formed so as to gradually increase from the connection area with the sub cutting edge 15 on the other end side (αb1 <αb2 <αb).
3), the honing twisted surface 25a. Therefore, the distance between the rake face 12 in the direction orthogonal to the rake face 12 and the main cutting edge 13 gradually increases, and the main cutting edge 13
Are formed so that the distance from the lower surface 11 gradually becomes shorter.

The throw-away tip 24 according to this embodiment has a face mill 21 similar to that of the first embodiment.
When it is attached to the cutter body 22 of the above, the first contact point with the work material at the time of biting is on the intersection ridge line L2 between the rake face 12 and the honing twisted face 25a, as in the case of the first embodiment described above. Point S2 or R2. Further, since the main cutting edge 13 is inclined with respect to the lower surface 11 of the throw-away tip 24, the actual axial rake angle of the main cutting edge 13 becomes larger than the angle β. Moreover, the radial rake angle γ gradually increases in the positive direction from the front end side toward the base end side. Therefore, the axial rake angle β
Is positive and the radial rake angle γ is positive (the honing angle αb is made larger than the value of γ) or negative, the tip side of the main cutting edge 13 has a sharpness as in the first embodiment. . Further, since the core is substantially lowered from the distal end side toward the proximal end side, it is possible to suppress the deterioration of sharpness due to the gradual increase of the honing angle αb, and it is possible to enhance the cutting edge strength of the proximal end side region. .

When the axial rake angle β is negative and the radial rake angle γ is negative or positive, the change of the honing angle αb of the throw-away tip 24 along the main cutting edge 13 of the honing 25 is shown in FIGS. 6 and 7. It may be reversed from the case shown. That is, the honing angle αb of the honing 25 along the main cutting edge 13 is set to gradually decrease from the connection area with the corner cutting edge 14 on the one end side toward the connection area with the sub cutting edge 15 on the other end side. With the throw-away tip 24 attached to the front milling cutter 21, the radial rake angle γ of the main cutting edge 13 is the maximum positive angle (negative or positive angle) on the tip side in relation to the negative axial rake angle β. Therefore, even if the honing angle αb is maximum at this position, the sharpness is relatively good and the cutting edge strength is high. The radial rake angle γ gradually increases in the negative direction in relation to the negative axial rake angle β as it goes from the leading end side to the base end side of the main cutting edge 13, but the honing angle αb decreases accordingly. Therefore, it is possible to suppress deterioration of sharpness.

Next, a third embodiment of the present invention will be described with reference to FIGS. 8 and 9, but the same parts or members as those in the above-mentioned embodiment will be designated by the same reference numerals and the description thereof will be omitted. . In the throw-away tip 28 shown in FIGS. 8 and 9, the honing 29 formed on the entire circumference of the ridgeline (cutting edges 13, 14, 15) of the upper surface 12 is shown in FIGS.
As shown in the sectional view of (c), the corner blade 14 on one end side
The honing angles αc are αc1, αc2, and αc3 from the connection region with the connection region with the secondary cutting edge 15 on the other end side.
The honing twisted surface 29a is formed so as to gradually increase to (αc1 <αc2 <αc3). Moreover, the width Tc of the honing twisted surface 29a in a plan view is from the connection region with the corner blade 14 on the one end side to the connection region with the sub cutting blade 15 on the other end side along the longitudinal direction of the main cutting blade 13. Toward Tc1, Tc2, Tc3 (Tc1 <T
c2 <Tc3) and gradually increases.

The width Wc of the honing 29 in side view, that is, the upper surface 12 from the upper surface 12 to the main cutting edge 13
The distance in the direction orthogonal to is W over the entire length in the longitudinal direction.
c1, Wc2, Wc3 (Wc1 <Wc2 <Wc3) and gradually increase. Therefore, the main cutting edge 13 is inclined so as to gradually approach the lower surface 11 from the connection area with the corner blade 14 on the one end side toward the connection area with the sub cutting edge 15 on the other end side.

The throw-away tip 28 according to this embodiment has a face mill 21 similar to that of the first embodiment.
When it is attached to the cutter body 22, the first contact point with the work material at the time of biting is the rake face 12 and the honing twisted face 29a regardless of the mounting posture as in the case of the first embodiment described above. It is the point S3 or R3 on the ridge line L3 intersecting with. Regarding the mounting posture of the tip 28, when the axial rake angle β is positive and the radial rake angle γ is negative or positive, the main cutting edge 13 is inclined with respect to the lower surface 11 of the throw-away tip 28. The actual axial rake angle of the main cutting edge 13 becomes larger than the angle β in the positive direction. Therefore, the radial rake angle γ gradually increases in the positive direction from the front end side to the base end side. Therefore, the tip of the main cutting edge 13 is as sharp as in the first embodiment. Then, since the core gradually descends from the tip end side toward the base end side, the gradual honing angle α
It is possible to suppress a decrease in sharpness due to an increase in c, and it is possible to increase the cutting edge strength in the base end side region.

Further, the mounting position of the throw-away tip 28 with respect to the front milling cutter 21 is determined by the axial rake angle β.
Is negative and the radial rake angle γ is negative or positive,
As with the second embodiment, with respect to the honing twisted surface 29a, the honing angle αc is gradually reduced along the main cutting edge 13 from the connection area with the corner blade 14 toward the connection area with the sub cutting edge 15. The same effect can be obtained by using a twisted surface that changes to. In this case, the distance Wc between the rake face 12 and the main cutting edge 13 in the direction orthogonal to the rake face needs to be gradually reduced, but the honing width Tc may be the same as that shown in FIG.

Next, a fourth embodiment of the present invention will be described with reference to FIG.
11 and FIG. 11, the same parts or members as those in the above-described embodiment are designated by the same reference numerals, and the description thereof will be omitted. Throw-away tip 3 shown in FIGS.
1, the ridge portion of the upper surface 12 (the cutting edges 13, 14, 1
5) The honing 32 formed on the entire circumference is shown in FIGS.
It is almost the same as in the third embodiment shown in FIG. The difference is that the honing surface 32 is formed in an arc shape having a radius r in the transverse cross section, and this honing 3
2 constitutes a round honing. And the honing angle α
d (αd1 <αd2 <αd3) is set as an angle between the rake face 12 and a line (a round honing string) that connects the intersection of the rake face 12 and the honing 32 with the main cutting edge 13 in the cross-sectional view. . The radius r of the cross section of the honing 32 does not have to be constant, and its size may change in the longitudinal direction or the circumferential direction of the cross section. In each of the above-described embodiments, the sub cutting edge 15 is provided, but the sub cutting edge 15 does not necessarily have to be provided, and the main cutting edge 13 and the corner blade 14 at each ridge portion are provided. It may be formed by.

Next, with respect to another example of the throw-away tip in which the principle configuration of each honing shown in each of the above-described embodiments is adopted, the same reference numerals are given to the same portions as those in the above-mentioned embodiments. It demonstrates using. The throw-away tip 34 shown in FIGS. 12 and 13 is a negative tip,
A main cutting edge 13 and a sub cutting edge 15 are provided on the ridges of the upper surface 12 and the lower surface 11 which are substantially parallel to each other. In the throw-away tip 34, the sub cutting edge 15 has a predetermined angle at both ends of the main cutting edge 13. And are connected to each other to form a corner portion. Then, on the upper and lower surfaces 12, 11, the honing 3 is formed in the region of the main cutting edge 13 and the sub cutting edge 15.
5 is formed over the entire circumference, and particularly the area of the main cutting edge 13 is the honing twist surface 35a shown in any of the above-described embodiments. A breaker groove 36 is formed inside the ridge.

The throw-away tip 38 shown in FIG. 14 and FIG. 15 is a substantially square plate-like positive tip for shoulder milling, in which the main cutting edge 13 is formed at each ridge, and the main cutting edge 13 is formed.
A sub-cutting edge 15 is formed between the main cutting edge 13 and one of the corner blades 14 and is inclined inwardly at a small angle with respect to the main cutting edge 13.
A honing 39 is formed over the entire circumference of the ridge portion, and a honing twist surface 39a according to each embodiment of the present invention is formed in at least the area of the main cutting edge 13, and the area of the sub cutting edge 15 is formed. Is connected to a wide flat land 40. A breaker 41 is formed along the entire circumference inside the honing twist surface 39a and the like.
Moreover, on the side surface 18 of the chip 38, the flank surface has a two-step positive structure from the lower surface 11 toward the upper surface 12.

In the throw-away tip 42 shown in FIGS. 16 and 17, the main cutting edge 13 formed on each ridge of the upper surface 12 extends from the connection area with the corner edge 14 on one end side to the other end side. Toward the connection area with the sub cutting edge 15, the lower surface 1 is gradually formed.
It is formed to be inclined to the 1 side. Such a main cutting edge 1
3, honing 43 is formed all around the sub cutting edge 15 and the corner blade 14. Moreover, these honing 4
Reference numeral 3 denotes at least a region of the main cutting edge 13 which serves as a honing twist surface 43a in each embodiment of the present invention.

Further, in the above-mentioned respective embodiments, the throw-away tip has a substantially square plate shape, but it is not limited to this and may have a triangular or other polygonal plate shape, or various shapes such as a vertical blade tip. The present invention can be applied to the throw-away tip. Further, although the throw-away tip according to the present invention has been described in the above embodiment as being attached to the front milling cutter for shoulder milling, it can also be used in a front milling cutter with corners as shown in FIG. It goes without saying that it can be attached to various cutting tools such as other cutting tools such as end mills and turning tools such as cutting tools. Further, in the throw-away tip according to the present invention, it is sufficient that at least the area of the main cutting edge 13 has a honing twist surface, and the corner blade 14 and the sub cutting edge 15 do not need to have honing.

[0029]

As described above, in the throw-away tip according to the present invention, the honing surface is formed in a twisted surface shape in which the honing angle gradually changes from one end side to the other end side of the cutting edge. Therefore, when cutting a work piece that is attached to a cutting tool, the cutting edge does not contact the work material first when biting, and the ridge line that intersects the rake surface inside the rake surface of the cutting edge and the honing surface Since it can be point-contacted on the top, and the cutting edge will then contact the work material to cut, the impact time of the chip when biting is long, the impact load can be dispersed on the rake face, The tool life is long because the blade is not likely to chip. Further, since the cutting edge that forms the intersecting ridgeline between the honing surface and the flank is inclined so as to gradually approach the seating surface from the one end side to the other end side, the cutting posture can be changed without changing the mounting posture of the tip. The angle of the blade can be adjusted, and the sharpness and cutting edge strength can be balanced according to the cutting depth. Further, in plan view, the width of the honing surface gradually changes from one end side to the other end side along the longitudinal direction of the cutting edge, so that the impact time at the time of biting is changed according to the mounting posture. It is possible to further disperse the impact load. Further, the throw-away tip is provided with a sub-cutting edge, and the sub-cutting edge is formed with a honing surface having a constant width and a constant honing angle in plan view along the longitudinal direction. Good finish cutting with the cutting edge.

[Brief description of drawings]

FIG. 1 relates to a throw-away tip according to a first embodiment of the present invention, (a) is a plan view and (b) is a side view.

2A is a sectional view taken along the line A1-A1 of the throw-away tip shown in FIG. 1A, FIG. 2B is a sectional view taken along the line B1-B1, and FIG. 2C is a sectional view taken along the line C1-C1. .

FIG. 3 is a partially cutaway front view showing a state in which the throw-away tip shown in FIG. 1 is mounted on a front milling cutter.

4 is a side view of the front milling cutter shown in FIG. 3. FIG.

5 is a bottom view of the front milling cutter shown in FIG. 3. FIG.

FIG. 6 relates to a throw-away tip according to a second embodiment of the present invention, in which (a) is a plan view and (b) is a side view.

7A is a sectional view taken along line A2-A2 of the throw-away tip shown in FIG. 6A, FIG. 7B is a sectional view taken along line B2-B2, and FIG. 7C is a sectional view taken along line C2-C2. .

FIG. 8 relates to a throw-away tip according to a third embodiment of the present invention, (a) is a plan view and (b) is a side view.

9A is a sectional view taken along line A3-A3 of the throw-away tip shown in FIG. 8A, FIG. 9B is a sectional view taken along line B3-B3, and FIG. 9C is a sectional view taken along line C3-C3. .

FIG. 10 relates to a throw-away tip according to a fourth embodiment of the present invention, (a) is a plan view and (b) is a side view.

11A is a sectional view taken along line A4-A4 of the throw-away tip shown in FIG. 10A, FIG. 11B is a sectional view taken along line B4-B4, and FIG. 11C is a sectional view taken along line C4-C4. .

FIG. 12 shows a specific example of a throw-away tip adopting the principle configuration of the throw-away tip in each embodiment, (a) is a plan view and (b) is a side view.

13 is a Y-Y of the throw-away tip shown in FIG.
It is a line sectional view.

FIG. 14 is a plan view showing another specific example of the throw-away tip adopting the principle configuration of the throw-away tip in each embodiment.

FIG. 15 is a side view of the throw-away tip shown in FIG.

FIG. 16 is a plan view showing another specific example of the throw-away tip adopting the principle configuration of the throw-away tip in each embodiment.

17 is a side view of the throw-away tip shown in FIG. 16. FIG.

FIG. 18 is an essential part explanatory view showing a cutting state of a work material by a conventional throw-away type cutter.

[Explanation of symbols]

10, 24, 28, 31, 34, 38, 42 Throw-away tip 13 Main cutting edge 15 Secondary cutting edge 11 Lower surface (seating surface) 12 Upper surface (rake surface) 19, 25, 29, 32, 35, 39, 43 Honing 19a, 25a, 29a, 32a, 35a, 39a, 4
3a Honing twist surface

Claims (6)

[Claims] 1. A throw-away tip having a cutting edge formed with a honing surface, wherein the honing surface has a twisted surface shape in which the honing angle gradually changes from one end side to the other end side of the cutting edge. Throw-away tip that is characterized by being. 2. The cutting edge forming an intersecting ridgeline between the honing surface and the flank surface is inclined so as to gradually approach the seating surface from one end side toward the other end side. Throw-away tip as described. 3. The throw-away tip according to claim 1, wherein the cutting edge forming the intersecting ridgeline between the honing surface and the flank is formed parallel to the seating surface. 4. The throw-away tip according to claim 1, wherein the width of the honing surface is set to be substantially equal to the longitudinal direction of the cutting edge in plan view. 5. A plan view, wherein the width of the honing surface is gradually changed from one end side to the other end side along the longitudinal direction of the cutting edge. The throw-away tip described in either one. 6. A sub cutting edge is provided on the throw-away tip, and a honing surface having a constant honing angle is formed along the longitudinal direction of the sub cutting edge with a constant width in plan view. The throw-away tip according to any one of claims 1 to 5, characterized in that: