JP3269217B2 - 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 cutting insert for cutting, and more particularly, to a cutting insert having a wider cutting condition area for obtaining good chip dischargeability.

[0002]

2. Description of the Related Art FIGS. 37 to 43 show a conventional example of a throw-away chip. Reference numeral 2 denotes a throw-away tip, which has an upper surface 4 and a lower surface 6 serving as seat surfaces for a cutting tool such as a cutting tool to be mounted. A side surface 8 perpendicular to the upper and lower surfaces 4 and 6 is a flank during cutting. The intersection line between the plane including the upper and lower surfaces 4 and 6 and the side surface 8 is a cutting edge 10. A breaker groove 12 is formed on the upper and lower surfaces 4 and 6 along the cutting blade 10.

The breaker groove 12 includes a land 14, a rake face 16, a bottom face 18, and a rising face 20 which continues to the top face 4. The upper surface 4 extends in a plane direction toward a corner portion 22 of a diamond-shaped acute angle formed by the throw-away tip 2. In the vicinity of the corner portion 22, a projection 24 for chip disposal is provided, and the projection 24 has a spherical shape. Note 2
Reference numeral 6 denotes a mounting hole for mounting the indexable insert to the tool body.

In the above-mentioned indexable insert 2,
Chips generated by performing cutting by applying the cutting blade 10 to a work material are guided by the projections 24 and discharged.

[0005]

However, since the projection 24 has a spherical shape, when it comes into contact with a chip in the form of a thin plate, it has to be in point contact, and therefore the direction of chip discharge is not stable. 39 , there is a problem that it is not determined in the direction of arrow A or the direction of arrow B in FIG. Further, since the projections 24 are in point contact with the chips, it is inevitable that the contact area gradually increases from the point contact state to the surface contact state with the progress of wear, and the chip processing performance changes. There is.

In consideration of the ability to discharge thin chips at the time of low cutting, it is preferable that the projections 24 be provided at a position close to the corner portion 22 so that the generated chips can be bent immediately. In consideration of the dischargeability of thick chips at the time of cutting, it is desirable to avoid chip clogging by providing the chip away from the corner portion 22. Therefore, the protrusions 24 have a certain shape and position.
However, there is a problem that it is difficult to adapt to a wide range of cutting conditions.

[0007]

In order to achieve the above object, the invention of claim 1 has a substantially polygonal plate-like planar shape and is formed around at least one of upper and lower surfaces of the polygonal shape. In the indexable insert provided with a breaker groove inside the cutting edge, a protrusion is provided which protrudes into the breaker groove from a central portion remaining inside the breaker groove toward a corner portion, and further from the protrusion. A protrusion protruding toward the corner portion is provided, the protrusion being lower than the protrusion and having a first inclined rising surface rising from the breaker groove around the protrusion; and a breaker provided on the protrusion. An inclined second rising surface rising from the groove is provided, and the second rising surface moves away from the cutting edge as the distance from the corner portion increases in a plan view. Is inclined in a direction, the projecting
The part has a substantially pentagonal shape, and the sharp vertex is
It is characterized by being arranged toward the corner portion . Also
According to a second aspect of the present invention, in the first aspect, the upper surface of the convex portion is provided.
Is a slope whose height is gradually reduced toward the corner
It is characterized by having a surface.

According to a third aspect of the present invention, the projection of the first aspect has a spherical surface.
It is characterized by forming a shape .

[0009]

[0010] The invention of claim 4 is based on claims 1 to 3
In the displacement , the two sides forming the acute angle of the protruding portion are inclined in a direction away from the cutting edge as the distance from the corner portion increases.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, a part of the cutting blade has a curved shape in a side view.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the width of the land portion formed along the cutting edge is wider in a region apart from the corner by a predetermined distance than in other regions. It is characterized by having been done.

[0013]

According to the above configuration, the chip discharging property at the time of low cutting can be ensured by the convex portion existing near the corner portion. Further, since the inclined first rising surface (rising surface 48) is provided around the convex portion, chips can be stably discharged in a certain direction by the first rising surface at the time of low cutting, and at the time of high cutting, Even if the chips try to get over the projections, they are guided by the protruding portions or the second rising surface thereof (rising surface 45) and are subjected to chip processing, so that chip clogging does not occur. Also, if the protrusion is five
Since it has a square shape, chips are constant by its ridgeline
You can be guided in the direction. Since the upper surface of the projection is inclined as in claim 2, it is possible to prevent chip clogging at a high cutting depth. The spherical convex portion according to the third aspect has a small contact area with the chip, so that the cutting resistance can be reduced. When the pentagonal ridge line is inclined as in claim 4 , the width of the breaker groove can be increased as the distance from the corner portion increases, so that chip clogging hardly occurs at high cutting depth. When the cutting blade has a curved shape as in claim 5 , the discharge performance at the time of low cutting is improved. When the width of the land portion is large as in claim 6 , it is possible to reinforce the range where the load is large at the time of high cutting.

[0014]

An embodiment of the present invention will be described with reference to the drawings.
In the figure, the same reference numerals are given to the same parts as the conventional example, and the description will be simplified. Also in this indexable insert 2, a breaker groove 32 is formed along the cutting edge 10, as in the conventional example. This breaker groove 32 has a land 34,
It comprises a rake face 36, a bottom face 38, and a rising face 40 continuing from the top face 4. The upper surface 4 extends in a plane direction toward a corner portion 22 of a diamond-shaped acute angle formed by the throw-away tip 2.

The upper surface 4 is extended in the surface direction toward the corner portion 22, and the protruding portion 42 existing at the extended portion is separated from a central portion 44 of the upper surface 4 by a groove 46. The protruding portion 42 has a substantially pentagonal shape in plan view, and is disposed such that the apex 41 of the pentagon that is the sharpest angle points toward the corner portion 22.
The ridge lines on both sides of the apex 41 are provided with an angle of α ° with respect to the cutting edge 10 so that the distance from the cutting edge 10 gradually increases as the distance from the corner portion 22 increases, as shown in FIG. I have.

As the ridge line of the central portion 44 of the upper surface 4 approaches the central portion of the cutting edge 10 from the corner portion 22 (the portion away from the corner portion 22), the distance from the cutting edge 10 increases from h1 in FIG. The slope is gradually increased to h2. The position of the protrusion 42 closest to the cutting blade 10 on the upper surface is arranged to be L / 4 to L / 2 with respect to the entire length L of the cutting blade 10. Similarly to the side of the upper surface 4, the side of the protruding portion 42 has the inclined rising surface 4 raised from the breaker groove 32.
It is 5.

A trapezoidal projection 47 in a side view is provided in the breaker groove 32 between the tip (a sharp vertex) of the projection 42 and the corner 22. The outer periphery of the projection 47 is a straight rising surface 48.
Is formed as an inclined surface 52 that is gradually lowered at an angle θ from the end portion 50 set at a position higher than the corner portion 22 toward the corner portion 22.

The indexable tip configured as described above is used, for example, by using the acute angle portion on the left side in FIG. In such cutting, the rising surface 48 of the projection 47 and the rising surface 45 of the projection 42 can make surface contact with the chips. Therefore, the chips can be guided stably in a certain direction, and there is little possibility that the chips are scattered or the work surface is deteriorated due to discharge in a direction approaching the workpiece. Further, the progress of wear is relatively slow due to the surface contact with the chip, and therefore, the change in the chip disposability is small from the start of cutting until the chip is used for a certain time, and stable chip disposition is realized.

Next, the action of the convex portion 47 and the rising surface 48 in accordance with the increase and decrease of the cut amount will be described. At the low depth of cut, the convex portion 47 and the rising surface 48 contribute to chip processing. At an intermediate cutting amount, both can perform chip processing. That is, since the convex portion 47 exists near the corner portion 22, braking can be performed even at a low depth of cut. On the other hand, since the upper surface is the inclined surface 52, the position near the corner portion 22 can be reduced. Despite the presence, chips can be discharged along the inclined surface 52, and chip clogging hardly occurs.

Since the projecting portion 42 has a substantially pentagonal shape and is inclined by α ° with respect to the cutting blade 10, chips can be reliably guided in a direction away from the processing surface. Further, the distance between the protruding portion 42 and the cutting blade 10 gradually increases as the distance from the corner portion 22 increases, so that the width of the breaker is ensured to be wider by that amount, and the cutting depth is high, that is, the range away from the corner portion 22 is reduced. In this case, it is possible to obtain a good chip discharge property.

FIG. 20 shows the result of an experiment on the chip discharge performance of the throw-away tip of FIG. 1 in comparison with the conventional throw-away tip. Generally, as the feed increases, the thickness of the chip increases, and as the cut increases, the width of the chip increases. Therefore,
In the area where both feed and cut are low (lower left area in the figure), extremely fine lint-like continuous chips are generated, and as the feed and cut increase (toward the upper right in the figure), fine spiral continuous From the chips, narrow-width chips (when the depth of cut is small) or wide-width chips (when the depth of cut is large). As the maximum depth or maximum feed is approached, a wide or thick spiral continuous Chips are generated. In FIG. 20, a range in which continuous chips are not generated is determined as a range in which chip processing is possible. The range indicated by the solid line in FIG. 20 is the processing range of the throw-away chip of the embodiment, and the range indicated by the chain line is the processing range of the conventional throw-away chip.

As is apparent from FIG. 20, in the indexable insert of the present invention, in particular, the projection 47 extending to the vicinity of the corner portion 22 and the rising surface 48 thereof provide an effect even at a low cutting depth. Since the sloping surface exhibits good chip disposability and the convex portion 47 is gradually lowered toward the corner portion 22, even if the notch becomes large, the chip which tries to get over the convex portion 47 is inclined. Along the inner side protrusion 42, and chips can be processed by the action of the protrusion 42 or its rising surface 45, so that chip clogging does not occur.

Since the distance from the cutting edge 10 at the center of the center portion 44 is large, the cutting edge 1 which is not used in the ordinary turning operation of the cutting depth and is not worn is used.
It is suitable when the central portion of 0 (the portion away from the corner portion 22) is used for other purposes, for example, for chamfering a workpiece. In addition to the central portion, the central portion 44 is the cutting edge 10.
(The area is large) so that a sufficient seating area can be ensured when the indexable insert is to be mounted on the tool body.

The range in which the central portion 44 is formed is set in the range of L / 4 to L / 2 of the entire cutting edge length L from the corner portion 22, and has a function of displaying the limit value of the maximum cutting amount. Further, the groove portion 46 separating the central portion 44 and the protruding portion 42 also has a function of displaying the limit value of the maximum cutting amount.

FIGS. 16 and 17 show a second embodiment of the present invention. In this embodiment, a part of the cutting blade 10A (a range separated from the corner 22 by a predetermined distance) is formed by the curved portion 6
It is set to 0. In this way, by forming a part of the cutting blade 10A as the curved portion 60, chips curved in the width direction are generated, and such curved mist is easily broken and has good dischargeability.

FIGS. 18 and 19 show a third embodiment of the present invention. In this embodiment, a wide land portion 62 having a width greater than a range closer to the corner portion 22 is provided from a position separated from the corner portion 22 by a predetermined distance.
By providing the wide land portion 62 in this manner, sufficient cutting edge strength can be obtained even at a high cutting depth.

As in the first to third embodiments described above, the throw-away tip having the nose portion provided with the trapezoidal projection 47 is made of TiC (titanium carbide), TiN (titanium nitride), or the like. This is effective in the case of a cermet made mainly of a material having poor thermal conductivity. This is for the following reason.

That is, the trapezoidal shape having a flat surface on the upper surface makes surface contact with the chips, so that the cutting heat is dispersed, the progress of friction is suppressed, and the life is prevented from being shortened. You get it.

On the other hand, the indexable insert of the fourth embodiment shown in FIG. 21 and subsequent figures is effective for use as a CVD (Chemical Vapor Deposition) coating tip made of a cemented carbide having good thermal conductivity. That is, C
The indexable insert with VD coating is
Since the main component is WC (tungsten carbide) having a thermal conductivity that is about three times that of TiC, there is an advantage that cutting heat is easily released and wear progresses slowly. However, if there is a trapezoidal convex portion as in the first to third embodiments, the chip comes into surface contact with the chip, so that the cutting resistance becomes high. Point contact is made.

Also in this indexable insert 2A, a breaker groove 32 is formed along the cutting edge 10, as in the conventional example. This breaker groove 32 has a land 34,
It comprises a rake face 36, a bottom face 38, and a rising face 40 continuing from the top face 4. The upper surface 4 extends in a plane direction toward a corner portion 22 of a diamond-shaped acute angle formed by the throw-away tip 2.

The upper surface 4 is extended in the surface direction toward the corner portion 22, and the protruding portion 42 present at the extended portion is separated from the central portion 44 of the upper surface 4 by a groove 46. The protruding portion 42 has a substantially pentagonal shape in plan view, and is disposed such that the apex 41 of the pentagon that is the sharpest angle points toward the corner portion 22.
The ridge lines on both sides of the apex 41 are provided with an angle of α ° with respect to the cutting edge 10 so that the distance from the cutting edge 10 gradually increases as the distance from the corner portion 22 increases, as shown in FIG. I have.

As the ridge line of the central portion 44 of the upper surface 4 approaches the central portion of the cutting blade 10 from the corner portion 22 (the portion distant from the corner portion 22), the distance from h1 to h2 as in FIG. It is inclined to become gradually larger.

In the breaker groove 32 between the tip (a sharp vertex) of the protrusion 42 and the corner 22, the first
A spherical convex portion 80 is provided instead of the trapezoidal convex portion 47 of the embodiment to the third embodiment. The height of the apex of the protrusion 80 is set higher than the corner 22 and lower than the protrusion 42.

Further, the breaker groove 32 includes a land 34, a rake face 36, a bottom face 38, and a rising face 40 continuing to the top face 4, as in the first embodiment. In addition, the land 34 has a width l narrower on the side closer to the corner portion 22, and the width l is set wider as the land 34 is further away from the corner portion 22 (as the notch becomes larger). In the illustrated embodiment, the width is gradually increased with respect to the total length L of the cutting blade when the distance from the corner portion is in the range of L / 6 to L / 4. Specifically, l = 0.1 to 0.25 mm is set at the corner, and the width of the land 34 at the center (outside the range of L / 6 to L / 4 from the corner) is l + 0.15. ０．２0.25 mm. That is, since the convex portion 80 has a spherical shape, it must be located far from the corner portion 22 as compared with the trapezoidal convex portion (in the case of the first embodiment). Therefore, in order to obtain the same chip discharge property as the trapezoidal convex portion on the low cutting side, it is necessary to reduce the width of the land portion 34 near the corner portion 22. Note that, in a range away from the corner portion 22, the width of the land portion 34 is increased in priority to the cutting edge strength over the chip dischargeability.

Also in the fourth embodiment, similar to the throw-away tip of the first embodiment, since the projections 42 each having a substantially pentagonal planar shape are provided, the clogging of chips at the time of high cutting is prevented. It can be prevented, and a certain directionality can be given to the chip discharging direction.

The throw away tip of the fourth embodiment and the first
33 and 34 will be described by comparing the cutting state with the indexable insert of the embodiment. In the indexable insert of the first embodiment, as shown in FIG. 33, the rising surface 48 of the trapezoidal convex portion 47 and the chip 82 generated from the work W are in surface contact at the contact surface Y, so that they are in contact with each other. The area is large, and in the indexable insert of the fourth embodiment, as shown in FIG.
Is spherical, the chip 82 comes into point contact with the projection 80 at the contact point Z, and therefore has a smaller contact area and smaller cutting resistance than those of the first embodiment.

As described above, the indexable insert of the fourth embodiment is suitably used for a CVD coated indexable insert made of a cemented carbide that is softer than cermet, and can effectively prevent the flank wear. FIG. 35 shows a state of the side surface of the throw-away tip after use. As shown in this figure, the vicinity of the tip of the throw-away insert is plastically deformed by the cutting resistance, and
In FIG. 5, the flank (the side surface 8) in the hatched area is worn away, and this tendency is remarkable especially in a soft cemented carbide indexable insert. In the indexable insert of the fourth embodiment, the provision of the spherical projection 80 as described above can reduce cutting resistance and prevent wear of the flank.

The shape of the first embodiment (shape having a trapezoidal convex portion) and the shape of the fourth embodiment (shape having a spherical convex portion) were obtained by using a cemented carbide CVD coated throwaway tip. Fig. 3 shows the flank wear width measured at
The result as shown in FIG. 6 was obtained. That is, after a certain amount of cutting time has passed, plastic deformation tends to occur in the cemented carbide tip which is softer than the cermet. When such plastic deformation progresses, the flank wear rapidly progresses in the throw-away insert having a trapezoidal convex portion having a large cutting resistance as in the first embodiment, and the flank wear width increases. Has been confirmed by

The present invention is not limited to the above-described embodiment, but can be modified without departing from the scope of the present invention.

[0040]

As is apparent from the above description, the present invention is directed to a method of forming a breakaway groove from a central portion remaining inside a breaker groove of a throw-away chip having a substantially polygonal plate-like planar shape toward a corner portion. And a projection projecting further from the projection is provided, and the projection is lower than the projection and has an inclined first rising surface rising from the breaker groove around the projection. The projecting portion is provided with an inclined second rising surface rising from the breaker groove, and the second rising surface is inclined in a direction away from the cutting edge as the distance from the corner portion increases in a plan view. And said
The protruding portion has a substantially pentagonal shape, and has an acute vertex
Since it is arranged toward the corner , it can be processed by curling chips on the first rising surface at low cutting depth,
At the time of high cutting, the chip which is going to get over the convex part is sent to the protruding part by the convex part and the first rising surface and can be curled on the second rising surface and can be processed. Therefore, chips can be stably discharged in a certain direction even at a low cut or a high cut. In addition, since the second rising surface is separated from the cutting edge, there is an operational effect that chip clogging hardly occurs even when the cut is deep. Further protrusion
Has a pentagonal shape.
Guiding in a certain direction, such as away from the processing surface
Can be. Also, by inclining the upper surface of the convex portion, chips at the time of high cutting are not clogged with chips. In addition, by making the shape of the convex portion spherical, it is possible to make a point contact with the chip and reduce the cutting resistance. The spherical convex portion is suitably used for a throw-away tip obtained by applying a CVD coating to a cemented carbide and effectively prevents wear of a flank. Furthermore, if the pentagonal ridge line is inclined, the width of the breaker groove can be increased as the distance from the corner increases, so that chip clogging hardly occurs at high cutting depth. When the cutting blade has a curved shape, the discharge property at the time of low cutting is improved, and when the width of the land portion is large, the range where the load at the time of high cutting is large can be reinforced.

[Brief description of the drawings]

FIG. 1 is a plan view of a throw-away tip of one embodiment.

FIG. 2 is a side view of the indexable tip of FIG. 1;

FIG. 3 is an enlarged view of a part X in FIG. 1;

FIG. 4 is a side view of the portion shown in FIG.

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

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

FIG. 7 is an arrow view along the line 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 a view as viewed in the direction of arrows along the line FF in FIG. 3;

FIG. 12 is a view along arrow GG in FIG. 3;

FIG. 13 is an arrow view along the line HH in FIG. 3;

FIG. 14 is a view taken in the direction of arrows along the line II in FIG. 3;

15 is a view taken in the direction of arrows along the line JJ in FIG. 3;

FIG. 16 is a plan view of a second embodiment of the present invention.

FIG. 17 is a side view of a second embodiment of the present invention.

FIG. 18 is a plan view of a third embodiment of the present invention.

FIG. 19 is a side view of a third embodiment of the present invention.

FIG. 20 is a table showing experimental results of a chip processing range of the throw-away chips of FIGS. 1 and 37.

FIG. 21 is a plan view of a throw-away tip according to a fourth embodiment of the present invention.

FIG. 22 is a side view of the throw away tip of FIG. 21;

FIG. 23 is an enlarged view of a part X in FIG. 21;

FIG. 24 is a side view of the portion shown in FIG. 23;

FIG. 25 is a view taken along the line HH in FIG. 23;

FIG. 26 is a view taken in the direction of arrows along the line AA in FIG. 23;

FIG. 27 is a view as viewed in the direction of arrows along the line BB in FIG. 23;

FIG. 28 is an arrow view along the line CC in FIG. 23;

FIG. 29 is a view taken along the line DD in FIG. 23;

30 is a view as viewed from the direction of the arrows along the line EE in FIG. 23;

FIG. 31 is a view taken in the direction of arrows along the line FF in FIG. 23;

FIG. 32 is an arrow view along the line GG in FIG. 23;

FIG. 33 is an explanatory diagram of a chip processing state in the throw away tip of the first embodiment.

FIG. 34 is an explanatory diagram of a chip disposal state of a throw away tip of the fourth embodiment.

FIG. 35 is a side view showing a worn state of the indexable insert of the fourth embodiment.

FIG. 36 is a table showing the results of a tool wear test of the indexable inserts of the first embodiment and the fourth embodiment.

FIG. 37 is a plan view of a conventional throw-away tip.

FIG. 38 is a side view of the throw-away tip of FIG. 37.

FIG. 39 is an enlarged view of a Y part in FIG. 37;

40 is a view as viewed in the direction of arrows along the line OO in FIG. 39.

FIG. 41 is a view taken in the direction of arrows along line LL in FIG. 39;

FIG. 42 is a view taken along the line MM in FIG. 39;

FIG. 43 is a view taken in the direction of arrows along the line NN in FIG. 39;

[Explanation of symbols]

 2 Indexable insert 4 Upper surface 10 Cutting edge 32 Breaker groove 42 Projection 44 Central part 45 Rising surface 46 Groove 47 Convex part 48 Rise surface 50 End part 52 Inclined surface 60 Curved part 62 Wide land part 80 Convex part

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor: Osamu Ichinoseki 1151, Furamagi, Ishishita-cho, Yuki-gun, Ibaraki Prefecture Inside of Tsukuba Works, Mitsubishi Materials Corporation (72) Inventor: Yuichi Suzuki 1151, Furimagi, Ishishita-cho, Yuki-gun, Ibaraki Prefecture Mitsubishi Materials Corporation Tsukuba Works (56) References JP-A-5-177416 (JP, A) JP-A 61-75908 (JP, U) JP-A-1-101706 (JP, U) JP-A 5-105 53807 (JP, U) JP-A-3-82103 (JP, U) JP-A-3-40004 (JP, U) (58) Fields studied (Int. Cl. ⁷ , DB name) B23B 27/22 B23B 27 /14

Claims (6)

(57) [Claims] 1. A throwaway chip having a substantially polygonal plate-like planar shape, wherein a breaker groove is provided inside a cutting edge formed around at least one of upper and lower surfaces forming the polygonal shape. In addition to providing a protrusion projecting into the breaker groove from the central portion remaining inside the breaker groove toward the corner portion, a protrusion projecting further from the protrusion portion toward the corner portion is provided, and the protrusion is An inclined first rising surface rising from the breaker groove is provided around and around the lower part of the projecting portion, and an inclined second rising surface rising from the breaker groove is provided in the projecting portion. The two rising surfaces are inclined in a direction away from the cutting edge as the distance from the corner portion increases in a plan view, and the protrusion is substantially a pentagon
Shape, and point the sharp-angled vertex toward the corner
A throw-away tip characterized by being arranged in a vertical position. 2. The indexable insert according to claim 1, wherein the upper surface of the projection is an inclined surface whose height is gradually reduced toward a corner. 3. The indexable insert according to claim 1, wherein the convex portion has a spherical shape. 4. The method of claim 1, two sides forming the acute angle of the protruding portion, characterized in that it is inclined in the direction away from the cutting edge with increasing distance from the corner portion
4. The throw-away tip according to any one of claims 1 to 3 . 5. A cutting insert according to any one of 4 to a portion of the cutting edge is no claim 1, wherein the curvilinear shape in side view. 6. A width of the land portion formed along the cutting edge, any one of claims 1 to 5, characterized in that it is wider than other regions at a predetermined distance away region from the corner portion The throw-away tip described in.