JP3237372B2 - 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 throw-away insert which is detachably attached to a tool body of a cutting tool.

[0002]

2. Description of the Related Art Some indexable inserts are provided with a breaker on a rake face connected to the nose in order to improve the processing ability of chips generated at the nose of the cutting blade during cutting. As a conventional example of this kind of throw-away chip, the applicant's prior application, Japanese Utility Model Application No. 3-108006 is disclosed.
Or Japanese Utility Model Application No. 3-108007.

In this indexable insert, a projection provided toward a nose portion has a convex curved surface shape higher than a cutting edge.
The radius of curvature of the convex surface decreases as it approaches the upper end of the projection, and the center of curvature is further away from the tip of the nose as it approaches the upper end of the breaker. In this indexable tip, by adopting such a configuration, the rising of the projection is made gentle to prevent chip clogging, and the tip of the projection is sufficiently brought close to the tip of the nose, Low cutting depth, ensuring chip breaking capability in the area.

[0004]

In the above-mentioned indexable insert, although the protrusion having the above-mentioned shape functions as a breaker, good chip discharge in a low cutting area is ensured, but the position is extremely close to the nose. , The contact area between the chip and the breaker tends to be large, and the cutting resistance tends to be large.Also, in the case of high cutting and high feed, When such a large amount of chips is generated, chips tend to be clogged in the breaker. In addition, since the breaker portion protrudes in a convex curved shape, the contact area between the breaker portion and the seating surface of the tool main body is reduced, and the mounting stability to the tool main body tends to be lacking.

[0005] Further, since the above-mentioned indexable insert is mainly used for cutting using the nose portion, the nose portion is selectively worn, and eventually becomes damaged and becomes unusable.
In this case, in terms of economy, there is a case where the center portion (a portion between the nose portions) which is not much consumed is used for another processing such as chamfering processing by using the cutting edge. Although this chamfering is desirably performed at a relatively high feed rate in terms of work efficiency, chip clogging is likely to occur as described above, so feed is limited and work efficiency is poor. is there.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and can prevent chip clogging at high cutting and high feeding while ensuring good chip cutting performance at low cutting and low feeding. It is an object of the present invention to provide a stable throwaway tip.

[0007]

According to a first aspect of the present invention, a chip body having a polygonal plate shape is provided with cutting edges having nose portions at both ends of an intersection ridge line between a rake face and a flank face,
In a throw-away chip provided with a groove-shaped breaker in a region inside the cutting edge on the rake face connected to the nose portion, the cutting edge is, when viewed from a side, the nose portion being the highest portion from the nose portion. It has an inclined portion lowered as it separates, and a horizontal portion having a constant height connected to the lowest portion of the inclined portion, and the width of the breaker at the inclined portion of the cutting edge is separated from the nose portion. gradually increases with approaching the horizontal portion Te, of the breaker
The width is measured in the horizontal part of the area farthest from the nose.
The width of the breaker at the slope is greater than
Closer to the nose than where the breaker is widest
Other parts in the area that covers the top and
It is characterized by the provision of dimples that are recessed from the minute .
According to a second aspect of the present invention, in the first aspect, the vibration
Is wider in the area closer to the nose than the horizontal.
Has been narrowed. The invention according to claim 3
In the first or second aspect, a land portion is provided on a cutting blade of the horizontal portion. Claim 4
The invention according to any one of claims 1 to 3 , wherein the upper and lower surfaces of the chip body have the same shape, and the shape of each surface is point-symmetric or point-symmetric.

[0008]

According to the first aspect of the present invention, since the cutting edge near the nose portion is provided with the inclined portion that is inclined with increasing distance from the nose portion, chips bent in accordance with the inclination are generated. In addition, the width of the breaker increases in a region away from the nose portion used as the notch increases, so that the chip accommodation volume of the breaker increases with an increase in the amount of chips. Further, the closer the area is away from the nose, in other words, the area used for high cutting, the greater the difference in height between the inner wall of the breaker and the cutting edge, so that the chips can be positively bent. Also the surface
For high-feed cutting with a large amount of chips generated, such as when machining
In the horizontal part of the used cutting edge, a sufficiently large volume
Secured. In addition, in areas where large amounts of
Spreads the breaker, thus preventing chip clogging.
Is stopped. According to the configuration of the second aspect , it is possible to easily bend the chip by bending it immediately after the chip is generated in a region near the nose portion used at the time of low cutting. According to the configuration of claim 3 , since the cutting edge in the central region is strengthened, the feed can be increased when this region is used for processing such as chamfering. According to the configuration of claim 4 , the surface of the throw-away insert according to any one of claims 1 to 5, which is not used for cutting, is used as a seating surface for attachment to a tool, and is provided near a breaker. , And a portion where the breaker width is reduced, so that the seating area can be increased, and since they are symmetrical, the seating stability is improved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a schematic configuration of an embodiment will be described with reference to FIG. The tip body 10 of this indexable tip is
It is formed by forming a hard material such as cermet or cemented carbide into a polygonal shape (a rhombus in the illustrated example), and a pair of upper and lower surfaces 11 and 12 arranged in the thickness direction, and around these upper and lower surfaces 11 and 12, Four sides 13 provided perpendicular to
And a mounting hole 14 penetrating the center of the throw-away tip 10.

The upper surface 11 is composed of a boss surface 15 having a planar shape orthogonal to the mounting hole 14 and a rake surface 16 lower than the boss surface 15. The intersection line is a cutting edge 17, and a nose portion 18 is formed between adjacent cutting edges 17. As a result, the side surface 13 is a flank during cutting.

As shown in FIG. 2, the cutting edge 17 has a high area near the nose portions 18 at both ends, a low area at the center, and a concave shape as a whole. , A flat land portion 19 is provided. An inclined cutting edge 1 is provided in a region between the central portion where the land portion 19 is present and the nose portion 18 (region up to the point P in FIG. 1).
8a are provided. In the case of the embodiment, the range in which the land portion 19 is provided is set to a position separated from the nose portion 18 by 2/3 of a distance l2 from a maximum width portion of the breaker described later.

The upper surface 11 has a planar shape as shown in FIG. 1, and the inside of the cutting blade 17 is a breaker 21. Hereinafter, the configuration of the breaker 21 will be described.
The nose portion 18 is provided with a protrusion 20 in a direction that substantially bisects the nose portion. The protrusion 20 has the same height as the upper surface 11 and is gradually widened toward the center to be continuous with the boss surface 15. As a result, the upper surface 1
Along with 1, the seating area at the time of attachment to the tool main body is ensured large. A sloping rising surface 21 is provided around the boss surface 15 including the protrusion 20, and is connected to the bottom 22.

The base end of the projection 20 in plan view gradually widens and continues to the upper surface 11. The bottom portion 22 has a nose portion 1 in FIG.
At a position separated by a distance l2 from 8, a breaker shape is formed so that the breaker width w1 becomes the largest. As a result, the volume of the breaker is secured even in the case of middle feed or high feed, and chip clogging is prevented.

The width w2 of the bottom portion 22 is the smallest at a position apart from the nose portion 18 by a distance l1.
As a result of making the width w2 of this portion the narrowest, the area of the upper surface 11 can be increased to secure a seating area, and such a narrow portion can be used as an index indicating the maximum cutting amount by an operator. It can be easily recognized.

Further, a dimple 24 that is concave from the upper surface 11 to the rising surface 23 is provided near a portion where the width of the breaker 21 is narrowest, so that clogging of chips in this portion is prevented. further,
The width of the breaker 21 is set to w3, which is the widest at the substantially central part of the cutting blade 17, so that the chip handling property in the chamfering process with a large cut is improved.

The operation of the indexable insert having the above configuration will be described. In the examples, the low-cut or low-feed cutting area means that the cut amount is 0.5 to 2.0 mm.
Means the area where the feed amount is 0.25 mm / rev or less. As shown in FIG. 1, since the cutting blade 18 a provided in continuation with the nose portion 18 is inclined, FIG.
The chip 30 bent at the center in the shape of a letter as shown in FIG.
Occurs. Therefore, as shown in FIG. 11 (b), a flat chip 30 'generated when the cutting edge is not inclined.
As compared with, the apparent thickness t1 is larger than the thickness t2 of the flat chip 30 'even for the same cut. Therefore, the chips 30 are easily cut off, and even when the feed rate is low and the cutting depth is low, an obstacle due to the continuous chips is unlikely to occur.

As is clear from the comparison of the generation of chips in FIGS. 8 and 9, the step h between the tip of the cutting edge 17 and the upper surface 11 of the throw-away tip is separated from the nose portion 18 and at the center of the cutting edge. It gets bigger as it gets closer. As for the breaker width, the width w2 at a position near the center is smaller than the width w1 at a position near the nose portion 18. Therefore, at a position away from the nose portion 18, the chip 30 bends with a smaller radius of curvature, so that the chip 30 can be cut in a high-cut area reaching, for example, about 2/5 of the entire cutting edge length and at a low feed rate. Can be easily divided by positively colliding with the breaker wall to bend slightly.

On the other hand, when the feed amount is, for example, 0.3 mm
In the high feed region of / rev or more, the nose portion 18
Since the width of the breaker is as large as w1 at a distant position, clogging hardly occurs even when a large amount of chips is generated.

Furthermore, a cutting blade 1 used at the time of high cutting
Since the land portion 19 is provided at the center portion of 7 and the cutting edge is strengthened, good working efficiency can be obtained by utilizing it for high-feed machining such as chamfering. Since the lower surface 12 of the chip body 10 has the same shape as the upper surface 11, the description is omitted.

FIG. 12 shows a comparison of the chip processing range between the throw-away tip of the present invention and the conventional example (the throw-away tip described in Japanese Utility Model Laid-Open No. 5-53806). That is, in dry cutting with a work material 45C (HB180) and a cutting speed of 150 m / min, in the case of low cutting and low feed, and in the case of high cutting and low feed, the chip disposability is improved as compared with the conventional example. Is shown by experiment. In the above experiment, it is not possible to generate chips entangled in lint, but it is possible to generate continuous spring-shaped chips wound with a small radius of curvature, or to generate split chips. And the chip processing range was determined.

Further, in the indexable insert of the embodiment, since both the upper surface and the lower surface are symmetrical with respect to a point or a line, when this is seated on the tool body,
Since the protrusions and the narrow portions of the breaker width are in average contact with the tool main body with a large area, good seating stability can be obtained.

The planar shape of the chip body is not limited to the rhombus of the above-described embodiment, but may be another quadrangle such as a parallelogram or a polygon such as a triangle. The shape of the breaker may be different from the embodiment as long as the dimensions directly related to the effects of the present invention, such as the width and the depth, match. Although the upper and lower surfaces of the throw-away tip of the embodiment have the same shape, they may have different shapes.
Further, it is needless to say that the shapes of the upper surface and the lower surface are not limited to symmetric shapes.

[0023]

As is apparent from the above description, according to the first aspect of the present invention, since the cutting edge near the nose is provided with the inclined portion which is inclined with increasing distance from the nose, this inclination is provided. As the chips are bent in accordance with the formula (1), the apparent thickness of the chips increases, and the chips are easily broken. Further, as the notch increases, the width of the breaker increases in a region away from the nose portion to be used, so that the volume of the breaker increases in accordance with the increase in the amount of chips, so that clogging of chips hardly occurs. Furthermore, as the difference between the height of the inner wall of the breaker and the cutting edge increases as the region approaches the region far from the nose, in other words, the region used for high cutting, the chips are bent with a smaller radius of curvature, and therefore, Even if the notch is small, it is flexed positively,
Good chip discharge performance is ensured. Also, chamfering
When used for high-feed cutting with large amounts of chips, such as
Also, chip clogging hardly occurs. In addition, large amounts of chips are generated
The breaker is spread out in the area where the
Clogging is prevented. According to the configuration of the second aspect, in the region near the nose portion used at the time of low cutting, the chips are positively bent, so that the chips are easily discharged, and good chip discharging property is secured. Further, since such a change in the shape (width) of the breaker can be easily visually recognized by the operator, it can be used as an index for recognizing the boundary between the low cut region and the high cut region. According to the configuration of claim 3 , since the cutting edge in the central region is reinforced,
When this region is used for processing such as chamfering, the feed can be increased. According to the configuration of claim 4 , the surface that is not used for cutting is used as a seating surface for attachment to a tool, and a protrusion that extends near the breaker and a portion where the breaker width is reduced are used. Since they are present, the seating area can be increased, and since they are symmetrical, seating stability is improved.

[Brief description of the drawings]

FIG. 1 is a plan view of one embodiment.

FIG. 2 is a side view of one embodiment.

FIG. 3 is an enlarged view of a portion F in FIG. 1;

FIG. 4 is an enlarged view of a portion G in FIG. 2;

FIG. 5 is a view taken in the direction of arrows along the line II in FIG. 3;

FIG. 6 is an arrow view along the line AA in FIG. 3;

FIG. 7 is a view along arrow BB in FIG. 3;

FIG. 8 is an arrow view along the line CC in FIG. 3;

FIG. 9 is a view taken in the direction of arrows along the line DD in FIG. 3;

FIG. 10 is an arrow view along the line EE in FIG. 3;

FIG. 11 is an explanatory diagram of chips generated by the throw away tip of one embodiment.

FIG. 12 is a table showing the results of a cutting test.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Chip main body 11 Upper surface 12 Lower surface 15 Boss surface 16 Rake surface 17 Cutting blade 18 Nose 18a Cutting blade 19 Land 20 Breaker 21 Projection 22 Bottom 23 Rising surface 24 Dimple

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshihiro Kitagawa 1511 Furimagi, Ishishita-cho, Yuki-gun, Ibaraki Prefecture Inside the Tsukuba Works, Mitsubishi Materials Corporation (72) Inventor Osamu Ichinoseki 1511 Furimagi, Ishishita-cho, Yuki-gun, Ibaraki Prefecture Mitsubishi Materials Corporation Tsukuba Works (72) Inventor Yuichi Suzuki 1511 Komagi, Ishishita-cho, Yuki-gun, Ibaraki Prefecture Mitsubishi Materials Corporation Tsukuba Works (56) References JP-A-63-174803 (JP, A) (58) ) Field surveyed (Int.Cl. ⁷ , DB name) B23B 27/14 B23B 27/16 B23B 27/22

Claims (4)

(57) [Claims] 1. A cutting body having a nose portion at both ends of an intersection ridge line between a rake face and a flank face is provided on a chip body having a polygonal plate shape, and the cutting edge on the rake face connected to the nose portion is provided. In a throw-away insert provided with a groove-shaped breaker in an inner area, the cutting edge has a nose portion as a highest portion in a side view, and an inclined portion which is lowered as being away from the nose portion, and a lowest portion continuous with a constant height as the horizontal part of the width of the breaker in the inclined portion of the cutting edge, gradually increases with approaching the horizontal portion away from said nose portion, said The width of the breaker is the area farthest from the nose
In the horizontal part, the width of the breaker at the inclined part
And the area closer to the nose than where the breaker is widest
Other parts in the area that covers the top and
A throwaway tip that has dimples that are more concave than the minute . 2. The throw-away chip according to claim 1 , wherein a width of the breaker is reduced in a region closer to a nose portion than the horizontal portion. 3. A cutting insert according to claim 1 or 2, characterized in that the land portion cutting blade of the horizontal portion is provided. 4. the same shape upper and lower surfaces of the chip body, throwing according to any one of claims 1 to 3, characterized in that the shape of each surface forms a point-symmetrical or point-symmetrical Away tip.