JP2537111Y2 - Indexable tip - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throwaway insert detachably mounted on a tool body, and more particularly, to a throwaway insert capable of always exhibiting good chip discharge performance even when the cutting depth of a cutting edge changes. Regarding chips.

[0002]

2. Description of the Related Art Conventionally, for example, a tip 1 shown in FIGS. 10 to 14 is known as a throw-away tip (hereinafter abbreviated as a tip) mounted on a tool body of a cutting tool such as a cutting tool. The chip 1 is made of a hard material such as a cemented carbide or a ceramic material, and is formed into a substantially triangular flat plate as a whole. And the side faces 5 arranged around the rake face 4 are flank faces 6.
Formed at the peripheral edge of the rake face 4 is a breaker groove 7 extending from the corner C of the rake face 4 to the adjacent corner C in the circumferential direction in a clockwise direction. A bottom surface 8 intersecting with the surface 6 and a wall surface 9 rising from the bottom surface 8 are provided, and the intersection ridge line between the bottom surface 8 of the breaker groove 7 and the flank 6 is formed as a cutting edge 10. Chips generated by the blades 10 and extending along the bottom surface 8 of the breaker groove 7 are pressed against the wall surface 9 of the breaker groove 7 to curl the chip into small pieces, thereby embrittlement of the chips to promote the cutting.

Here, breaker grooves formed in this type of chip are roughly classified into a stamping type which is integrally formed during compression molding of the chip and a sharpening type which is formed by grinding after forming the chip. However, the illustrated breaker groove 7 belongs to the latter, and is formed by moving a grindstone having a desired shape from the corner C of the rake face 4 toward the adjacent corner C. In such a sharpening type breaker groove 7, the bottom surface 8 is inclined at a constant positive rake angle α に お い て in a direction orthogonal to the cutting edge 10 (FIGS. 11 and 12).
), And is also inclined at a constant positive rake angle β ゜ in the direction along the cutting edge 10 (see FIGS. 13 and 14). In addition, the extending direction of the breaker groove 7 is as shown in FIG.
It is inclined by a desired angle γ 角度 with respect to the cutting blade 10 so that the side away from the corner C escapes to the outer peripheral side of the chip.

In such a chip having a sharpened breaker groove 7, since the breaker groove 7 is inclined by γ ゜ with respect to the cutting edge 10, the groove in the direction perpendicular to the cutting edge 10 of the breaker groove 7 is formed. The width decreases as the distance from the corner C increases, and when comparing the groove width m ₁ on the side close to the corner C with the groove width m ₂ at a position sufficiently distant from the corner C, m ₁ > m ₂ . (See FIGS. 11 and 12). Also, the groove width in the direction along the cutting blade 10 decreases as the distance from the cutting blade 10 decreases, and the groove width n ₁ on the side closer to the cutting blade 10 and the groove width n ₂ at a position further away from the cutting blade 10. And n ₁ > n ₂ (see FIG. 1).
3, see FIG. 14).

[0005]

However, in the conventional chip in which the groove width of the breaker groove 7 changes as described above, as the cutting amount of the cutting edge 10 increases in the direction along the cutting edge 10,
Since the breaker width m is reduced and the wall surface 9 approaches the cutting blade 10, chips are easily clogged. On the other hand, if the breaker width m in the direction perpendicular to the cutting edge 10 is increased over the entire length of the breaker groove 7 in order to prevent chip clogging when the cutting amount is large, the vicinity of the corner C is increased. The wall surface 9 is far away from the cutting blade 10, and the breaker effect when the cutting amount is small is greatly impaired. The present invention has been made under such a background, and an object of the invention is to provide a chip that can always exhibit good chip discharge performance even when the cutting depth of the cutting blade changes.

[0006]

In order to solve the above-mentioned problems, the present invention is directed to a device having a substantially polygonal plate shape, wherein at least one of upper and lower surfaces arranged in a thickness direction is a rake surface, and a periphery of the rake surface is provided. Is formed as a flank, and a breaker groove extending from the corner of the rake face to a corner adjacent to the rake face in a predetermined range is formed on an outer peripheral portion of the rake face. A bottom surface intersecting the surface, a wall surface rising from the bottom surface and extending along the extending direction of the breaker groove, and a wall surface extending in a direction intersecting the extending direction. A chip in which the intersection ridge line portion with the flank is a cutting edge, wherein the groove width of the breaker groove on a cross section orthogonal to the cutting edge is from a corner of the rake face to an adjacent corner. It gradually increases as you go,
In addition, the bottom surface of the breaker groove is inclined so as to form a positive rake angle with respect to the rake surface in a direction along the cutting edge, and the extension of the breaker groove
The intersection of the rake face with the wall extending in the direction
The ridge line extends in a direction substantially orthogonal to the cutting edge .

[0007]

According to the above construction, the groove width on the cross section orthogonal to the cutting edge of the breaker groove gradually increases from the corner of the rake face to the adjacent corner, so that the amount of cut can be increased. Accordingly, the groove width of the breaker groove also increases. Thus, when the cut amount is small, the chips sequentially collide with the wall surface of the breaker groove at the narrow portion of the breaker groove, thereby preventing excessive elongation of the chips and obtaining a good chip discharge property. When the cut amount is large, the chip width is sufficiently widened, so that chips are smoothly discharged without being clogged. In addition, since the bottom surface of the breaker groove is inclined at a positive rake angle with respect to the rake face in a direction along the cutting edge, cutting resistance applied to the cutting edge is reduced, and chips generated by the cutting edge are reduced. While flowing to the side where the groove width of the breaker groove is increased along the inclination of the bottom surface of the breaker groove, the breaker groove hits the wall surface of the breaker groove. And
The wall of the breaker groove against which the chip collides retreats inward with the chip as the groove width of the breaker groove increases, so that the chip after colliding with the wall is not pushed back in the direction directly opposite to the original growth direction. Then, the curl curls while changing the growth direction so that the breaker groove expands. For this reason, the chip discharge performance is not impaired due to the burrs of the chip colliding with the wall surface of the breaker groove. Moreover, it intersects with the direction in which the breaker groove extends.
Between the wall and the rake face of the breaker groove
Since the intersection ridge extends in a direction almost perpendicular to the cutting edge,
The chip is cut out more than necessary by this breaker groove
To prevent the chip strength from being impaired.
And the area of the rake face is limited due to the small size of the chip.
Or if the rake face has mounting holes
The breaker grooves may interfere with each other or between the breaker groove and the mounting hole.
Can also be prevented.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. As shown in FIGS. 1 to 5, the chip 20 according to the present embodiment is formed in a substantially triangular flat plate shape using a hard material such as a cemented carbide or ceramics as a material similar to the conventional chip shown in FIG. Of the upper and lower surfaces 21, 22 arranged in the thickness direction, the upper surface 21 is a rake surface 23, and the side surface 24 disposed around the rake surface 23 is a flank surface 25 inclined at a regular angle with respect to the rake surface 23. , And the chip 20 with the chip 20 in the center of the rake face 23.
3 is provided with a mounting hole 20a penetrating in a direction perpendicular to the rake face 23.
Are formed in a predetermined range from the corner C of the rake face 23 to the adjacent corner C in the circumferential direction of the rake face 23 in the clockwise direction. In the following, the side of each breaker groove 26 that contacts the corner C is referred to as the leading end of the breaker groove 26, and the side away from the corner C to the adjacent corner C is referred to as the rear end of the breaker groove 26.

The breaker groove 26 has a bottom surface 27 intersecting with the flank 25, and stands upright from the bottom surface 27 and has a breaker groove.
A wall 28 extending along the extending direction of 26, the breaker groove
26, which stands on the rear end side from the bottom surface 27, and
A wall extending in a direction intersecting the extending direction of the breaker groove 26
Made of and a surface 29, intersecting ridgeline portion between the flank 25 and the bottom surface 27 is a cutting edge 30 at the tip 20.

Here, as shown in more detail in FIGS. 2 and 3, the bottom surface 27 is
The rake face 23 is inclined at a positive rake angle α ゜. In addition, as shown in more detail in FIGS. 4 and 5, the bottom surface 27 also has a rake face 23 in a direction along the cutting edge 30.
At a positive rake angle β ゜. And
The rake angle β ゜ in the direction along the cutting edge 30 makes the cutting edge 3
Numeral 0 gradually retreats from the rake face 23 to the lower face 22 as it goes from the front end side to the rear end side of the breaker groove 26. Accordingly, the distance H ₁ from the rake face 23 on any one of a cross section perpendicular to the cutting edge 30 to the cutting edge 30, other cross-section located on the rear end side of the breaker groove 26 than the first section When compared with the above distance H ₂ , the relationship H ₁ <H ₂ always holds (FIGS. 2 and 3).
reference).

Also, as shown in FIGS.
7 is inclined at a positive rake angle α ゜ in a direction perpendicular to the cutting edge 30, so that the rake face 2 on a cross section parallel to the cutting edge 30.
The distance from 3 to the intersection ridge line between the bottom surface 27 and the flank 25 is also the distance h ₁ on any one cross section, and the position farther from the corner C in the direction perpendicular to the cutting edge 30 than this one cross section. The relationship h ₁ <h ₂ is established when the distance h ₂ is compared with the distance h ₂ on another cross section in FIG. In the illustrated example, both the rake angles α ゜ and β ゜
7 is set to be constant over the entire surface, but it is of course conceivable to change it in multiple steps or to change it continuously.

As shown in FIGS. 1 to 3, of the wall surfaces 28 and 29 of the breaker groove 26, the wall surface 28 extending in the extending direction of the breaker groove 26 has a concave curved surface in contact with the bottom surface 27,
An inclined surface extending from the concave curved surface to the rake surface 23 at a constant inclination angle φ. And this wall surface 28
Is a plan view from a direction orthogonal to the rake face 23 (FIG. 1)
At the center of the rake face 23 from the direction in which the cutting edge 30 extends, so that the groove width of the breaker groove 26 on a cross section orthogonal to the cutting edge 30 is from the tip end of the breaker groove. It becomes gradually larger toward the rear end. For this reason, the groove width m ₁ on any one cross section orthogonal to the cutting blade 30 is defined as the groove width m ₂ on another cross section located on the rear end side of the breaker groove 26 with respect to this one cross section. When compared, the relationship m ₁ <m ₂ always holds (see FIG. 2).
And FIG. 3).

As shown in FIGS. 1, 4 and 5, the wall surface 29 of the breaker groove 26 has a relatively large radius of curvature from the bottom surface 27 to the rake surface 23 on the rear end side of the breaker groove 26. It rises while drawing a curved surface, and its intersection ridge line with the rake face 23 extends in a direction substantially orthogonal to the cutting edge 30. Thereby, the breaker groove 2
6 is maintained substantially constant irrespective of the distance from the cutting edge 30, as is apparent from comparison of the groove widths n ₁ and n ₂ in FIGS. 4 and 5. I have.

Here, as shown in FIGS. 6 to 8, the breaker groove 26 having the above-described structure is used to mount the cylindrical grindstone G on the rake face 23.
Is formed by pressing against the corner C of the grinding wheel G and moving in a specific direction. At this time, the inclination and the moving direction of the axis Q of the grindstone G are in a fixed relationship with respect to the chip 20, so that the above-described bottom surface is formed. 27, wall surfaces 28 and wall surfaces 29 are obtained. In other words, the grinding stone G has its axis Q
In this state, it is moved in the direction perpendicular to the rake face 23 in the direction perpendicular to the rake face 23 in the direction along the wall face 28, and at the same time, after the breaker groove 26, Lower surface 22 toward the end
Side, so that the breaker groove 26 described above is obtained.

In the chip 20 having the above-described structure, the groove width of the breaker groove 26, the inclination angle γ ゜ and the rake angle β ゜ with respect to the cutting edge 30 can be appropriately changed according to the material of the work material and the cutting conditions. The inclination angle γ ゜ is set in the range of 5 to 45 ° from the end of the wall surface 28 on the tip side of the breaker groove 26 to the cutting edge
Groove width m ₀ in the range of 0.2 to 1.5 mm, and
It is preferable to set the rake angle β ゜ in the range of 0 to 30 °.

In the chip 20 configured as described above, the groove width (m ₁ , m ₂ ) on the cross section orthogonal to the cutting edge 30 of the breaker groove 26 is set at the rear end side of the breaker groove 26. As the depth increases, the groove width increases accordingly, and the distance from the cutting edge 30 to the wall surface 28 increases when the cutting depth of the cutting edge 30 with respect to the work material is increased. Regardless of the size of the cutting amount, it is possible to always exhibit good chip dischargeability. That is, since the distance from the cutting edge 30 to the wall surface 28 is sufficiently short on the tip side of the breaker groove 26, the chips generated when the cutting depth is small do not successively collide with the wall surface 28 without excessively growing. Be divided. On the other hand, on the rear end side of the breaker groove 26, the distance from the cutting edge 30 to the wall surface 28 is sufficiently large.
Even when the cutting depth is large, the chips are smoothly discharged without clogging.

Further, since the bottom surface 27 of the breaker groove 26 is inclined at a positive rake angle β ゜ with respect to the rake face 23 in the direction along the cutting edge 30, cutting resistance applied to the cutting edge 30 is reduced. Also, the effect of improving sharpness can be obtained. In addition, since the bottom surface 27 has a positive rake angle β ゜, when the work material W is cut in a direction perpendicular to the cutting edge 30 as shown in FIG. The chips 40 flow toward the rear end of the breaker groove 26, that is, somewhat toward the side where the groove width is larger than the direction exactly opposite to the cutting progress direction (arrow S1 in the drawing), and hit the wall surface 28. Since the wall surface 28 itself also recedes toward the center of the chip 20 as the groove width of the breaker groove 26 increases, the chips 40 colliding with the wall surface 28 are pushed back in the direction exactly opposite to the original growth direction. Instead, as shown by the arrow S2 in the figure, the curl is changed to the rear end side of the breaker groove 26 while changing the growth direction. For this reason, the chip discharge performance is not impaired by the burrs of the chips 40 colliding with the wall surface 28 of the breaker groove 26. Incidentally, in the chip 1 shown in FIG.
After the chip collides with the wall surface 9, it is pushed back in a direction exactly opposite to the original growth direction, so that the chip newly generated from the cutting blade 10 and the burrs of the chip colliding with the wall surface 9 collide from the front. There is a risk of chip clogging. Moreover, blur
The wall surface 29 of the car groove 26 intersects with the rake face 23.
Since the ridge line extends in a direction almost perpendicular to the cutting edge,
The breaker 20 is cut unnecessarily by the breaker groove 26.
To prevent chipping and loss of chip strength.
The tip 20 is small and the rake face 23
When the product must be limited, or as in this embodiment,
For example, when the mounting hole 20a is formed on the rake face 23
The breaker grooves 26 and the breaker groove 26 and the mounting hole 20
a to interfere with or avoid such interference.
The size of the breaker groove 26 is limited to provide sufficient capacity
Prevent situations where it is impossible to secure
can do.

In this embodiment, a so-called positive tip in which the flank 25 is inclined at a regular angle to the rake face 23 is described as an example, but the flank 25 is orthogonal to the rake face 23. Needless to say, a negative chip may be used. The external shape of the chip is not limited to a triangle, but may be variously changed, such as a square, a parallelogram, or a rhombus. Further, in the present embodiment, the bottom surface 27 is
Is inclined at a positive rake angle α ゜ not only in the direction along the cutting edge 30 but also in the direction perpendicular to the cutting edge 30. However, the present invention is not limited to this, and the bottom surface 27 is fixed in the direction orthogonal to the cutting edge 30. The height may be set, that is, α ゜ = 0 ゜.

[0019]

As described above, according to the present invention, since the groove width of the breaker groove increases with an increase in the cut amount, a good chip discharge property can always be obtained regardless of the size of the cut amount. It has an excellent effect. In addition, since the bottom surface of the breaker groove is inclined at a positive rake angle with respect to the rake face in the direction along the cutting edge, cutting resistance applied to the cutting edge is reduced, and good sharpness is obtained. Is
Chips curl while changing their growth direction to the side where the groove width of the breaker groove is enlarged, so that chip burrs that hit the wall surface of the breaker groove do not impair the chip discharge property and increase the chip discharge property. Further improve. Moreover, the break
The wall surface extending in the direction intersecting with the extending direction of the groove
The intersection ridge line with the rake face extends in a direction almost perpendicular to the cutting edge
Cuts the chip more than necessary due to the breaker groove.
Chip strength can be maintained without chipping
The breaker grooves and between the breaker grooves and the mounting holes.
Ensure sufficient capacity in the breaker groove by preventing interference, etc.
It becomes possible.

[Brief description of the drawings]

FIG. 1 is a plan view of a chip according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a sectional view taken along line VV in FIG. 1;

FIG. 6 is a diagram showing a positional relationship between a chip and a grindstone when forming a breaker groove in the chip shown in FIG. 1 in a plan view of the chip.

FIG. 7 is a view as seen from the direction of the arrow VII in FIG. 6;

FIG. 8 is a view as seen from the direction of arrow VIII in FIG. 6;

FIG. 9 is a view schematically showing a growth state of chips when a work material is processed by the chip shown in FIG. 1;

FIG. 10 is a plan view of a conventional chip.

11 is a sectional view taken along line XI-XI in FIG.

12 is a sectional view taken along line XII-XII in FIG.

13 is a sectional view taken along line XIII-XIII in FIG.

FIG. 14 is a sectional view taken along line XIV-XIV in FIG. 10;

[Explanation of symbols]

 Reference Signs List 20 throw-away tip 21 upper surface 22 lower surface 23 rake face 24 side face 25 flank face 26 breaker groove 27 bottom face of breaker groove 28 wall face of breaker groove 30 cutting edge C corner of rake face β ゜Rake angle

Claims (1)

(57) [Scope of request for utility model registration] An outer surface is formed in a substantially polygonal plate shape, at least one of upper and lower surfaces arranged in a thickness direction is a rake face, and a side face disposed around the rake face is a flank face. A breaker groove extending in a predetermined range from a corner of the rake face to a corner adjacent to the rake face is formed on an outer peripheral portion. The breaker groove has a bottom surface that intersects the flank surface, It has a wall surface extending along the extending direction of the groove and a wall surface extending in a direction intersecting the extending direction, and an intersection ridge portion between the bottom surface and the flank surface of the breaker groove is a cutting edge. A throw-away tip,
The groove width of the breaker groove on a cross section orthogonal to the cutting edge gradually increases from a corner of the rake face to an adjacent corner, and the bottom surface of the breaker groove is
In the direction along the cutting edge, while being inclined to form a positive rake angle with respect to the rake surface ,
Wall surface extending in the direction intersecting with the extending direction of the breaker groove
The direction in which the ridge line intersecting with the rake face is almost perpendicular to the cutting edge
A throwaway tip that extends to