JP4957000B2 - Cutting tools - Google Patents

Description

The present invention relates to a cutting tool with a chip breaker, which has a cutting edge portion made of an ultra-high pressure sintered body and is suitable for turning of high hardness steel.

In turning of high hardness steel such as carburized and hardened steel and induction hardened steel, a cutting tool having a cutting edge made of an ultra-high pressure sintered body is mainly used. This type of conventional cutting tool is illustrated in FIG. This conventional cutting tool is intended to improve chip disposal, and an ultra-high hardness sintered body 3 is joined to a seat groove 2 formed on the upper surface of the tip corner of the tool body 1, and the ultra-high hardness firing is performed. It is a cutting tool with a chip breaker in which a cutting blade 7, a chip breaker 5, and a chamfered part 6 for cutting edge reinforcement are provided on the bonded body 3. And the chamfering part 8 is formed in the intersection part of each upper surface and side surface of the tool main body 1 and the ultra-high hardness sintered body 3, and the height H of the chamfering part 8 is ultra-high hardness sintering by chip breaker processing. The surface of the chamfered portion 6 for cutting edge reinforcement is larger than the amount h of the blade edge down from the upper surface of the body 3, and the surface of the chamfered portion 6 for reinforcing the blade edge is constituted by a part of the surface of the chamfered portion 8 having the height H (for example, Patent Document 1).

JP-A-8-155702

In the above conventional cutting tool, as the cutting progresses, the surface of the chamfered portion 6 for reinforcing the blade edge is worn away. When this wear reaches the chip breaker 5, the portion where the chip breaker 5 is formed is lower in strength than the chamfered portion 6 for reinforcing the blade edge, so that there is a problem that the cutting edge cannot be withstood by cutting and the cutting edge is suddenly lost. It was. In particular, when cutting hard materials such as hardened steel with a cutting tool made of ultra-high-pressure sintered material containing cubic boron nitride, the cutting resistance may become very large, so there is a possibility that the cutting edge will suddenly break. There was a problem that increased.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a cutting tool that increases the strength of the cutting edge portion and suppresses sudden loss due to wear of the cutting edge and has a long cutting edge life.

In order to solve the above-mentioned problem, the invention according to claim 1 includes a rake face, a flank face, and a cutting edge ridge formed on a cross ridge line of the rake face and the flank face on the upper surface corner portion of the tool body. A chip breaker having a breaker wall surface that protrudes from the surface of the rake face following the rake face and intersects the upper surface, and at least the cutting edge part is sintered at a high pressure. In the cutting tool comprising a body, the rake face is inclined so as to go upward as it goes inward from the cutting edge, and the angle formed with the upper face is set in a range of 5 ° to 25 °, and the breaker wall surface is As it goes inward, it is inclined upward and the angle formed with the upper surface is set in the range of 25 ° to 45 °. Further, a honing surface consisting of a flat inclined surface is formed on the cutting edge. Formed along the edge of the blade, An angle between the upper surface and the upper surface is set in a range of 15 ° to 40 °, and a width in a direction orthogonal to the cutting edge is viewed from a direction orthogonal to the upper surface in a range of 0.05 mm to 0.20 mm. It is set so that it may become. It is a cutting tool characterized by the above-mentioned.

The invention according to claim 2 has a cutting edge portion formed of a rake face, a flank face, and a cutting edge ridge formed on a cross ridge line of the rake face and the flank face in an upper surface corner portion of the tool body. A cutting tool that has a chip breaker that has a breaker wall surface that protrudes from the surface of the rake face following the rake face and intersects the upper face, and at least the cutting edge portion is made of an ultra-high pressure sintered body, The rake face is inclined so as to go upward as it goes inward from the cutting edge, and the angle between the rake face and the upper face is set in a range of 5 ° to 25 °, and goes upward as the breaker wall faces inward. And the angle between the upper surface and the upper surface is set in a range of 25 ° to 45 °. Further, the cutting edge is formed with a honing surface including a curved surface smoothly connected to both the rake surface and the flank surface. Formed along the edge of the cutting edge, Circular cross section of radius of curvature of the serial honing surface is a cutting tool, characterized in that it is set to a range of 0.01Mm～0.20Mm.

According to a third aspect of the present invention, in the first aspect of the invention, the intersection ridge line portion between the flat inclined surface and the flank constituting the honing surface is smoothly connected to both the inclined surface and the flank. A minute curved surface is formed along the ridge line portion, and a radius of curvature of a sectional arc of the minute curved surface is set in a range of 0.005 mm to 0.050 mm.

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, a curved surface that smoothly connects to both the breaker wall surface and the upper surface at the intersecting ridge line portion between the breaker wall surface and the upper surface. And a radius of curvature of a cross-section arc of the curved surface is set in a range of 0.05 mm to 0.20 mm.

The invention according to claim 5 is the invention according to any one of claims 1 to 4, characterized in that the ultra-high pressure sintered body is a polycrystalline sintered body containing cubic boron nitride.

In the first and second aspects of the invention, in the cutting edge portion, the rake face is inclined so as to go upward as it goes inward from the edge of the cutting edge, so that the strength of the portion where the rake face is formed. The strength of the cutting edge due to rake face wear is gradual, and the cutting edge is prevented from suddenly missing, thereby extending the cutting edge life. If the angle between the rake face and the upper surface is less than 5 °, the strength at the rake face cannot be secured, and the strength of the cutting edge due to wear of the rake face rapidly advances, so the effect of extending the cutting edge life cannot be obtained. If the angle exceeds 25 °, there is a risk that the chip processing property deteriorates, such as an increase in cutting resistance, clogging of chips, and chipping, so the angle is preferably set in the range of 5 ° to 25 °. Further, the chip breaker that rises from the rake face following the rake face restrains and curls or divides the chips that have collided with the breaker wall surface, so that chip disposal is further improved. The angle formed between the breaker wall surface and the upper surface is set in the range of 25 ° to 45 °. If the angle is less than 25 °, chips may not be restrained by the breaker wall surface and may not be curled or divided. Since the chip is strongly restrained by the breaker wall surface, there is a possibility that a chip disposal problem such as chip clogging may occur or a cutting resistance may be increased to cause chatter.

Further, a honing surface comprising a flat inclined surface provided along the cutting edge ridge (Claim 1), and a honing comprising a curved surface smoothly connected to both the rake face and the flank provided along the cutting edge ridge. The surface (Claim 2) further enhances the strength in the vicinity of the edge of the cutting edge of the cutting edge, and in particular prevents cracking in the vicinity of the edge of the cutting edge in intermittent cutting, and delays the progress of rake face wear. Extends the cutting edge life to moderate the strength drop. In addition, with the rake face inclined with respect to the upper surface, it acts to increase the thickness of the chip, stabilizes the outflow direction of the chip, and reliably causes the chip to collide with the breaker wall surface. When the angle formed between the honing surface and the upper surface formed by the inclined surface is less than 15 °, the effect of increasing the strength in the vicinity of the cutting edge is small, and when it exceeds 40 °, the sharpness is deteriorated and the cutting resistance is increased. Is generated, and chip adhesion occurs on the honing surface, which may deteriorate the surface roughness of the work surface of the work material. Further, when the width of the honing surface in the direction perpendicular to the cutting edge is less than 0.05 mm, the effect of increasing the strength in the vicinity of the cutting edge is small. There is a possibility of incurring, and even if it exceeds 0.20 mm, the effect of increasing the strength in the vicinity of the cutting edge is not increased, but the processing time and processing cost are increased, so the range of 0.05 mm to 0.20 mm It is desirable to set to. On the other hand, even in the honing surface composed of the curved surface, when the radius of curvature of the arc in the cross section orthogonal to the cutting edge is less than 0.01 mm, the effect of increasing the strength in the vicinity of the cutting edge is small. (About 0.1 mm) may lead to early chipping, and even if it exceeds 0.20 mm, the effect of increasing the strength in the vicinity of the cutting edge is not increased. In order to decrease and cutting resistance increase, it is desirable to set in the range of 0.05 mm to 0.20 mm.

As in the invention according to claim 3, in the invention according to claim 1, a minute curved surface smoothly connecting to both of the flat inclined surface and the flank surface is formed along the ridge line portion. Is effective in preventing initial defects due to repeated impacts at the time of intermittent cutting at the ridge line portion that becomes a sharp edge. If the radius of curvature of the arc in the cross section perpendicular to the cutting edge of the minute curved surface is less than 0.005 mm, the effect of preventing early loss of the ridge line portion cannot be obtained, and even if it exceeds 0.050 mm, The effect of preventing the initial defect is not increased, but instead the sharpness is lowered, so that chips adhere to the minute curved surface and the surface roughness and appearance quality of the processed surface deteriorate, so the range of 0.005 mm to 0.050 mm It is desirable to set to.

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, a curved surface that smoothly connects to both the breaker wall surface and the upper surface at the intersection ridge line portion between the breaker wall surface and the upper surface. Since the connecting portion is formed, the strength of the intersecting ridge line portion is increased, damage such as deficiency and breakage is suppressed, and stability of chip disposal is ensured. If the radius of curvature of the cross-section arc of the curved surface is less than 0.05 mm, the effect of preventing the damage cannot be obtained, and if the radius of curvature exceeds 0.20 mm, the effect does not increase. Therefore, it is desirable to set the thickness within a range of 0.05 mm to 0.20 mm.

The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein at least the cutting edge portion is made of a polycrystalline sintered body containing cubic boron nitride. This polycrystalline sintered body has a gradual rake face wear progression and extended cutting edge life in order to demonstrate high wear resistance in finish turning of hardened steel such as carburized hardened steel and induction hardened steel. enable.

Next, a cutting tool to which the present invention is applied will be described with reference to the drawings. 1A and 1B are a plan view and a side view of a cutting tool to which the present invention is applied, respectively. FIGS. 2A and 2B are an enlarged plan view and a side view, respectively, of the main part of the cutting tool shown in FIG. (A)-(d) of FIG. 3 is the S1-S1 sectional view taken on the line of the cutting tool shown in FIG. 1, respectively. FIG. 4 is a perspective view of another cutting tool to which the present invention is applied.

In FIG. 1, the tool body 10 of the present cutting tool 1 is made of a cemented carbide having a rhombic plate shape, and a notch step portion 14 is formed in a corner portion C of the upper surface 11 thereof. A cutting blade member 20 made of a polycrystalline sintered body containing cubic boron nitride is fixed to the notch step portion 14 by brazing. The cutting tool can be changed to a polygonal plate shape or a circular plate shape.

In the enlarged view of FIG. 2, a cutting edge ridge 41 including a circular arc and a pair of straight lines respectively extending from the circular arc is formed at the corner portion of the cutting blade member 20. The cutting edge ridge 41 is formed on an intersecting ridge line between the rake face 42 and the flank face 43, and a chip breaker 30 protruding toward the corner portion is formed inside the cutting edge ridge 41. The breaker wall surface 31 of the chip breaker 30 protrudes from the surface of the rake face 42 connected to the cutting edge ridge 41 and extends upward and inward, and is a cutting edge configured by a plane common to the upper surface 11 of the tool body 10. It intersects the upper surface 11 of the member 20. The breaker wall surface 31 includes a pair of inclined planes that intersect on the bisector of the corner portion C and are symmetric with respect to the bisector, and an angle α2 formed by these inclined planes in plan view. Is larger than the angle α1 formed by the corner portion, and is formed so that each inclined plane gradually approaches and intersects the cutting edge ridge 41 as the distance from the corner portion increases. In addition, as shown to (a) of FIG. 2, the intersection part on the said bisector may be smoothly rounded with a curved surface. The chip breaker 30, the rake face 42, and the flank face 43 are formed by at least one of a grinding method using a grinding wheel, an electric discharge machining, an electron beam machining, or a laser machining, for example.

In the cross-sectional view shown in FIG. 3A, the rake face 42 is inclined so as to go upward as it goes inward from the cutting edge ridge 41, and the inclination angle θ <b> 1 formed with the upper surface 11 of the cutting edge member 20 is 5. It is formed to be in the range of ° to 25 °. Further, in the cross section, the breaker wall surface 31 is also inclined so as to go upward as it goes inward, and the inclination angle θ2 formed with the upper surface 11 is in the range of 25 ° to 45 °. Considering that the chip collides with the breaker wall surface 31 and restrains it, the distance L from the cutting edge ridge 41 to the intersecting ridge line portion between the breaker wall surface 31 and the upper surface 11 is 0.3 mm when viewed from the direction orthogonal to the upper surface 11. It is desirable to set in the range of -2.0 mm.

Further, in FIG. 3A, a chamfered honing surface 50 made of a flat inclined surface is formed on the cutting edge ridge 41 along the cutting edge ridge 41. The honing surface 50 is formed by, for example, grinding using a grinding wheel, and is formed such that an inclination angle θ3 formed with the upper surface 11 is equal to or larger than an inclination angle θ1 of the rake face 42 and is in a range of 15 ° to 40 °. Has been. Further, the honing surface 50 is formed such that the width L3 in the direction orthogonal to the cutting edge ridge 41 is in the range of 0.05 mm to 0.20 mm when viewed from the direction orthogonal to the upper surface 11. Usually, the honing surface 50 is processed after the rake surface 42 is formed, and therefore the inclination angle θ1 of the honing surface 50 is larger than the inclination angle θ2 of the rake surface 42.

Modification examples of the honing surface of the cutting tool 1 are shown in FIGS. In FIG. 3B, a honing surface 51 formed of a curved surface smoothly connected to both the rake face 42 and the flank face 43 is provided along the cutting edge ridge 41. The honing surface 51 is formed by grinding using, for example, a brush with loose abrasive grains or a rubber grindstone mixed with loose abrasive grains, and a radius of curvature R3 is 0.01 mm in a cross section perpendicular to the cutting edge ridge 41. It is formed by an arc set in a range of ˜0.20 mm. 3 (c) shows that a chamfered honing surface 50 made of a flat inclined surface is provided along the cutting edge ridge 41, and then, at the intersecting ridge line portion of the honing surface 50 and the flank 43, A small curved surface 60 smoothly connected to both the honing surface 50 and the flank surface 43 is formed along the ridge line portion. The minute curved surface 60 is formed by grinding using, for example, a brush with loose abrasive grains or a rubber grindstone mixed with loose abrasive grains, and a curvature radius r3 is 0.005 mm in a cross section perpendicular to the cutting edge ridge 41. It is formed with an arc set in a range of ˜0.050 mm.

Further, as shown in FIG. 3D, in the chip breaker 30, a connecting portion 33 made of a curved surface smoothly connected to both the breaker wall surface 31 and the upper surface 11 of the cutting blade member 20 may be formed. The joint portion 33 is formed by at least one of grinding processing using a grinding wheel, electric discharge processing, electron beam processing, or laser processing at the same time as the chip breaker 30 is formed, or chip breaker molding. Later, for example, it is formed by grinding using a brush with loose abrasive grains or a rubber grindstone mixed with loose abrasive grains. The curved surface of the connecting portion 33 is formed by an arc whose curvature radius R4 is set in a range of 0.05 mm to 0.20 mm in a cross section orthogonal to the cutting edge ridge 41. Considering that the chip collides with the breaker wall surface 31 and restrains it, the distance L from the cutting edge 41 to the connecting portion between the connecting portion 33 and the upper surface 11 when viewed from the direction orthogonal to the upper surface 11 is 0.3 mm. It is desirable to set in the range of ˜3.0 mm.

An embodiment in which high-hardness steel is continuously turned by the cutting tool 1 described above will be described below. In the first embodiment, the cutting tool 1 uses a cutting blade member 20 made of a cubic boron nitride sintered body containing 65% by volume of cubic boron nitride and the balance being TiN as a main component. The inclination angle θ2 is fixed at 35 °, and the rake face 42 and the chamfered honing face 50 are set to various shapes shown in Table 1. With these cutting tools 1, the outer periphery of carburized and quenched steel having a surface hardness of 58-60 HRC in terms of Rockwell hardness was continuously turned. The continuous turning means a turning process in which the cutting edge portion 40 does not intermittently bite the work material and the cutting is substantially constant. Cutting conditions are a cutting speed of 150 m / min, a cutting depth of 0.25 mm, and a feed of 0.1 mm / rev. Ten data were collected for each sample. The defect probability in Table 1 indicates the defect occurrence rate at a cutting time of 40 minutes.

In Table 1, in the sample 1 in which the angle θ1 formed by the rake face 42 and the upper surface 11 is 0 °, since the strength of the portion where the rake face 42 is formed is not sufficient, the wear that causes the honing face 50 to be advanced proceeds. As the cutting edge portion 40 could not withstand the cutting resistance, a cutting edge defect occurred early, and the defect probability increased to 50%. On the other hand, in the samples 2 to 4 in which the angle formed by the rake face 42 and the upper surface 11 is in the range of 5 ° to 25 °, the strength of the portion where the rake face 42 is formed is sufficiently secured against the cutting resistance. For this reason, the strength reduction of the cutting edge portion 40 accompanying the wear of the honing surface 50 and the rake face 42 proceeds gradually, and it is prevented that the cutting edge is lost at an early stage. However, in the sample 5 in which the angle formed by the rake face 42 and the upper surface 11 exceeds 25 °, the sharpness is worsened, the cutting resistance is increased and chattering occurs, and chips with a clogging and seizing appearance are generated. The problem of scratching the machined surface occurred.

In the sample 6 in which the width L3 of the honing surface 50 is less than 0.05 mm and the sample 9 in which the inclination angle θ3 of the honing surface 50 is less than 15 °, the strength in the vicinity of the cutting edge ridge 41 where the load increases during cutting is small. An early cutting edge defect occurred under a feed condition of about 1 mm / rev, and the defect probability increased. On the other hand, in the sample 12 in which the inclination angle θ3 of the honing surface 50 exceeds 40 °, the sharpness is deteriorated and the cutting resistance is increased, so that chattering occurs during cutting and chip adhesion occurs on the honing surface 50 and the work material. The surface roughness of the processed surface deteriorated. On the other hand, in samples 2 to 4, 7, 8, 10, and 11 in which the width L3 of the honing surface 50 is 0.05 mm or more and the inclination angle θ3 of the honing surface 50 is set in the range of 15 ° to 40 °. Since the strength in the vicinity of the cutting edge ridge 41 is sufficiently secured, no early cutting edge defect was observed, and no defect probability occurred. Note that if the width L3 of the honing surface 50 exceeds 0.20 mm, the processing time and processing cost of the honing surface 50 increase, which is uneconomical. Therefore, the honing width L3 is set in the range of 0.05 mm to 0.20 mm. Is desirable.

Next, in sample 3 (a cutting tool in which the rake angle 42 of the rake face 42 is 20 °, the width L3 of the honing surface 50 is 0.05 mm, and the honing surface inclination angle θ3 is 15 °), the inclination angle θ2 of the breaker wall surface 31 is set. The same continuous turning process was performed. Table 2 shows the chip disposability at that time.

In Table 2, in the sample 13 in which the inclination angle θ2 of the breaker wall surface 31 is less than 25 °, the chips cannot be restrained by the breaker wall surface 31 and cannot be curled or divided. Oops. On the other hand, in the sample 17 in which the inclination angle θ2 of the breaker wall surface 31 exceeds 45 °, the chip is strongly restrained by the breaker wall surface 31 and seems to be clogged, so that there are problems of chip disposal and chatter during cutting.

Next, the same continuous turning process was performed on the cutting tool 1 provided with the honing surface 51 formed of a curved surface by using various values of the radius of curvature R3 of the cross-section arc of the honing surface 51 (breaker wall surface 31). Was fixed at 35 °). The results are shown in Table 3.

In Table 3, in the sample 18 in which the radius of curvature R3 of the cross-section arc of the honing surface 51 is less than 0.01 mm, the strength in the vicinity of the cutting edge ridge 41 cannot be secured, and an early defect occurs under a feed condition of about 0.1 mm / rev. As a result, the probability of loss increased. On the other hand, in the sample 22 in which the radius of curvature R3 of the cross-section arc of the honing surface 51 exceeds 0.20 mm, the defect probability is low, but the processing time and processing cost of the honing surface 51 are increased and uneconomical, and the sharpness is poor. As a result, the cutting resistance increases, so that chatter occurs during cutting and chip adhesion occurs on the honing surface 51, resulting in deterioration of the surface roughness of the work surface of the work material. On the other hand, in the samples 19 to 21 in which the radius of curvature R3 of the cross-section arc of the honing surface 51 is set in the range of 0.01 mm to 0.20 mm, the strength in the vicinity of the cutting edge ridge 41 is secured, and the early cutting Blade defects were suppressed and the probability of defects was very small.

Next, an example in which intermittent turning is performed using various cutting tools 1 shown in Table 4 will be described (the inclination angle θ2 of the breaker wall surface 31 is fixed at 35 °). With these cutting tools 1, the outer periphery of carburized and quenched steel having a surface hardness of 58-60 HRC in terms of Rockwell hardness was intermittently turned. In this embodiment, the feeding and cutting are constant, and intermittent turning is performed in which the cutting edge ridge 41 is bitten and detached from the work material at a very short cycle. Cutting conditions are a cutting speed of 120 m / min, a cutting depth of 0.2 mm, and a feed of 0.1 mm / rev. Ten data were collected for each sample. The defect probability in Table 4 indicates the defect occurrence rate at a cutting time of 20 minutes.

In Table 4, in the samples 3 and 6 to 12 to which the chamfered honing surface 50 was attached, since the probability of occurrence of early cutting edge defects was increased as compared with the above-described continuous turning process, the defect probability increased. Samples 3, 7, 8, 10, and 11 (invention) in which the width L3 of the honing surface 50 is 0.05 mm or more and the inclination angle θ3 of the honing surface 50 is in the range of 15 ° to 40 ° are the honing surfaces. Compared with Samples 6 and 9 (Comparative Example) in which the width L3 of 50 and the inclination angle θ3 of the honing surface 50 are less than those of the present invention, the early cutting edge defects were extremely small and the defect probability was low. In the sample 12 (comparative example) in which the inclination angle θ3 of the honing surface 50 exceeds 40 °, the sharpness is deteriorated and the cutting resistance is increased as in the case of continuous turning, and thus chatter is generated during cutting, and chips are formed on the honing surface 50. The surface roughness of the work surface of the work material deteriorated. On the other hand, in the samples 18 to 22 with the honing surface 51 made of a curved surface, the defect probability was the same as that of continuous turning. That is, Samples 19 to 21 (invention) in which the radius of curvature R3 of the cross-section arc of the honing surface 51 is in the range of 0.01 mm to 0.20 mm are the same as Sample 18 (Comparative Example) in which the curvature radius R3 is less than 0.01 mm. ), The strength in the vicinity of the cutting edge ridge 41 is ensured, early cutting edge defects are suppressed, and the defect probability is extremely small. From the above results, in the samples 3 and 6 to 12 to which the honing surface 50 made of a flat inclined surface is attached, the intersecting ridge line portion between the honing surface 50 and the flank surface 43 becomes a sharp edge. It is considered that the initial deficiency can not be tolerated. Therefore, in Sample 3, a cutting surface in which a minute curved surface 60 smoothly connected to both the honing surface 50 and the flank 43 is formed along the cross ridge line portion at the cross ridge line portion between the chamfered honing surface 50 and the flank surface 43. The same intermittent turning was performed using the tool 1. Table 5 shows the curvature radius r3 and the defect probability of the minute curved surface 60.

In sample 3A in which the radius of curvature r3 of the cross-section arc of the minute curved surface 60 is less than 0.005 mm, the initial defect of the intersecting ridge line portion between the chamfered honing surface 50 and the flank 43 could not be suppressed. There was no difference in missing probability with sample 3 (shown in Table 4). Further, in the sample 7F in which the radius of curvature r3 exceeds 0.050 mm, the initial chipping is suppressed, but the sharpness is deteriorated. Therefore, chip adhesion occurs on the micro-curved surface 60 and the work surface of the work material, and thus the work surface. The surface roughness of was deteriorated. On the other hand, in the samples 3B to 3E in which the radius of curvature r3 of the cross-section arc of the minute curved surface 60 is in the range of 0.005 mm to 0.050 mm, the strength of the intersecting ridge line portion between the chamfered honing surface 50 and the flank 43 is high. As a result, no initial defect was observed, and the defect probability was 0%. And since the sharpness does not fall, the surface roughness of the processed surface of a work material was favorable.

The cutting tool 1 shown in FIG. 4 is provided with a cutting edge portion 40 made of a polycrystalline sintered body containing cubic boron nitride at a diagonal corner portion of the upper surface 11 of a tool body 10 having a square plate shape. The member 20 is fixed by brazing. As in the previous embodiment, a chip breaker 30 having a breaker wall surface 31 extending upward and inward from the surface of the rake face 42 is formed inside the cutting edge ridge 41. The breaker wall surface 31 extends in parallel with a pair of linear cutting edge ridges 41 extending from the corner portion C, and extends not only to the cutting blade member 20 but also to the tool body 10 and reaches the adjacent corner portion. Furthermore, the cross-sectional shape obtained by cutting the chip breaker 30 along a plane orthogonal to the cutting edge ridge 41 is substantially equal at each position.

According to the cutting tool 1 having such a configuration, since the cross-sectional shape of the chip breaker 30 at each position of the cutting edge ridge 41 is constant, it is possible to eliminate the influence of cutting on the chip disposal, and from finishing to rough machining. Excellent chip disposal is realized in a wide range of cutting conditions or machining where the cutting varies. Moreover, since the chip breaker 30 formed over the entire circumference is manufactured by cutting the breaker wall surface 31 having the same cross-sectional shape in a direction parallel to the ridge side of the tool body 10, a grinding wheel is used. It can be easily manufactured by a general grinding process. Even if the cutting blade member 20 is brazed and fixed to all the corners of the upper surface 11 having a square shape of the tool body 10, the ease of manufacture does not change and the number of times of use per cutting tool increases. growing.

(A) And (b) is the top view and side view of the cutting tool to which this invention is applied, respectively. It is a perspective view of a throw away tip to which the present invention is applied. (A) And (b) is the top view and side view which expanded the principal part of the cutting tool shown in FIG. 1, respectively. (A)-(d) is each S1-S1 sectional view taken on the line in FIG. It is a perspective view of the other cutting tool to which this invention is applied. It is a figure explaining the conventional cutting tool, (a) is a perspective view, (b) is a top view, (c) is a side view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cutting tool 10 Tool main body 11 Upper surface 20 Cutting blade member 30 Chip breaker 31 Breaker wall surface 40 Cutting blade part 41 Cutting edge ridge 42 Rake face 43 Relief face 50, 51 Honing face 60 Small curved surface (theta) 1 Angle which makes a rake face and an upper surface (theta) 2 Breaker Angle θ3 formed by wall surface and top surface Angle L3 formed by honing surface and top surface Width R3 of honing surface perpendicular to cutting edge R3 Curvature radius of honing surface made of curved surface r3 Curvature radius of cross section arc of micro curved surface

Claims (5)

The upper surface corner portion of the tool body has a cutting edge portion composed of a rake face, a flank face, and a cutting edge ridge formed on a cross ridge line of the rake face and the flank face, and the rake face is followed by the rake face. In a cutting tool that has a chip breaker that protrudes from the surface of the rake face and has a breaker wall surface that intersects the upper surface, at least the cutting edge portion is made of an ultra-high pressure sintered body,
The rake face is inclined so as to go upward as it goes inward from the cutting edge, and the angle formed by the rake face and the upper face is set in a range of 5 ° to 25 °,
The breaker wall surface is inclined so as to go upward as it goes inward, and an angle formed by the breaker wall surface and the upper surface is set in a range of 25 ° to 45 ° ,
The front SL cutting edge is formed by honing surface formed from a flat inclined surface along the cutting edge ridge, the honing face is the angle formed between the upper surface is set in a range of 15 ° to 40 °, and The width in the direction orthogonal to the cutting edge ridge as viewed from the direction orthogonal to the upper surface is set to be in the range of 0.05 mm to 0.20 mm ,
The angle formed between the honing surface and the upper surface is set larger than the angle formed between the rake surface and the upper surface,
Furthermore, when viewed from a direction orthogonal to the upper surface, a distance from the cutting edge to the intersecting ridge line portion between the breaker wall surface and the upper surface is set in a range of 0.3 mm to 2.0 mm. Cutting tools. The upper surface corner portion of the tool body has a cutting edge portion composed of a rake face, a flank face, and a cutting edge ridge formed on a cross ridge line of the rake face and the flank face, and the rake face is followed by the rake face. In a cutting tool that has a chip breaker that protrudes from the surface of the rake face and has a breaker wall surface that intersects the upper surface, at least the cutting edge portion is made of an ultra-high pressure sintered body,
The rake face is inclined so as to go upward as it goes inward from the cutting edge, and the angle formed by the rake face and the upper face is set in a range of 5 ° to 25 °,
The breaker wall surface is inclined so as to go upward as it goes inward, and an angle formed by the breaker wall surface and the upper surface is set in a range of 25 ° to 45 ° ,
The front SL cutting edge, honing surface formed of a curved surface smoothly connected to both the rake face and the flank face is formed along the cutting edge ridge, the radius of curvature of the arcuate cross-sectional of the honing surface 0.01mm~ Set to a range of 0.20 mm ,
Furthermore, when viewed from a direction orthogonal to the upper surface, a distance from the cutting edge to the intersecting ridge line portion between the breaker wall surface and the upper surface is set in a range of 0.3 mm to 2.0 mm. Cutting tools.   A micro-curved surface smoothly connected to both the inclined surface and the flank surface is formed along the ridge line portion at the intersecting ridge line portion between the flat inclined surface and the flank surface constituting the honing surface. The cutting tool according to claim 1, wherein the radius of curvature of the arc of section is set in a range of 0.005 mm to 0.050 mm.   A connecting portion made of a curved surface smoothly connected to both the breaker wall surface and the upper surface is formed at the intersecting ridge line portion between the breaker wall surface and the upper surface, and the curvature radius of the cross-section arc of the curved surface is 0.05 mm to 0.00 mm. The cutting tool according to any one of claims 1 to 3, wherein the cutting tool is set in a range of 20 mm. The cutting tool according to any one of claims 1 to 4, wherein the ultra-high pressure sintered body is a polycrystalline sintered body containing cubic boron nitride .

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