JP2010125566A - Cutting tip, cutting tool, and method for cutting hard-to-cut material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the breakage of a boundary region of a cutting tip which has been a problem when cutting a hard-to-cut material with cutting depth exceeding, for example, 0.3 mm. <P>SOLUTION: The cutting tip 1 has a cut surface 5 obtained by removing a corner disposed between two side surfaces 4, 4 which constitute a corner. A ridge line 9 constituting a main cutting blade is formed between the cut surface 5 and an upper surface 2. While the cutting tip is mounted to a holder of a turning tool, the ridge line 9 is inclined to an angle wherein the lateral cutting edge angle α can be set at 60° or larger and 90° or smaller. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cutting tip effective for cutting difficult-to-cut materials, a cutting tool (bite) using the cutting tip, and a cutting method. In addition, the difficult-to-cut material mentioned here refers to a work material whose material is a heat-resistant alloy, a Ti alloy, or maraging steel, for example.

  Among known cutting tips, there is a diamond-shaped tip provided with an acute corner portion and an obtuse corner portion at diagonal positions. The acute corner portion of this rhombus tip is configured as a nose R portion having a predetermined R radius, and the ridge line of the nose R portion (the ridge line at the intersection of the side surface and the upper surface) in the outer diameter turning of the work material Is used as a cutting edge. When used under conditions where the depth of cut is small, only the curved ridgeline of the nose R part is involved in cutting as a cutting edge. However, if the cutting depth is increased, a part of the straight ridgeline connected to the nose R part is also used as a cutting edge. used.

  Note that a general cutting tip, for example, a triangular tip, a square tip, or a rhombus tip, has a nose radius (R radius) set to about 0.2 to 1.6 mm.

  Here, in the cutting under the condition that the first cutting edge (main cutting edge) and the second cutting edge, each of which is a straight line, are connected to each other through a sharp boundary portion, and the cutting depth is 0.3 mm or less. A cutting insert in which the first cutting edge mainly cuts the work material and the subsequent second cutting edge works as a cutting edge to finish the surface is disclosed in Patent Document 1 below.

  This cutting insert was developed for the purpose of reducing the cutting energy by reducing the cutting area by the first cutting edge, thereby reducing the heat generated by cutting and extending the life. With the outer diameter turning, the first cutting edge is cut into the work material with an inclination angle of 3 to 30 ° with respect to the axis of the work material.

JP 2005-324324 A

  Suppose now that the outer diameter turning of the work material is performed under the condition of a cutting depth of 0.3 mm using a general-purpose rhombus insert having an acute corner corner nose R of 1.6 mm. At this time, the inclination angle κ (inclination angle with respect to the axis of the work material) of the nose R portion cutting edge at the outermost diameter part of the work material is about 35.7 °. This value is about 54.3 ° in terms of the horizontal cutting edge angle obtained by the formula of (90 ° −inclination angle κ). However, in the processing of the difficult-to-cut materials mentioned above, the depth of cut exceeds 0.3 mm. When machining was performed under the conditions, it was found that if the side cutting edge angle is less than 60 °, defects frequently occur at the lateral boundary portion of the cutting edge (the portion corresponding to the outermost diameter portion of the work material). In the processing of difficult-to-cut materials, hard materials such as sintered bodies containing cemented carbide and cBN (cubic boron nitride) are frequently used as the material for cutting chips, but even chips using cBN-containing sintered bodies are used. A defect at the lateral boundary has occurred.

  A general cutting tip is provided with a nose R, and even if the nose R is large, it is about 1.6 mm. Therefore, the side cutting edge angle is set to 60 ° or more in processing under a condition where the cutting depth exceeds 0.3 mm. It cannot be set. If the radius of the nose radius is increased to the point where it is possible to set a side cutting edge angle of 60 ° or more, the cutting tip will be subject to machining restrictions, so it is possible to increase the radius of the radius of the nose radius. I can't even hope.

  Further, the cutting insert disclosed in the above-mentioned Patent Document 1 has an inclination angle of the first cutting edge (main cutting edge) with respect to the axis of the work material of 3 to 30 °. The value is 87 to 60 ° in terms of the horizontal cutting edge angle, but the cutting insert of Patent Document 1 is such that the first cutting edge corresponds to a cutting depth of 0.05 to 0.3 mm. . Therefore, when it is used under the condition that the depth of cut exceeds 0.3 mm, the side cutting edge denoted by reference numeral 17 in FIGS. 2, 3 and 5 of the same document is involved in the cutting. The side cutting edge has a side cutting edge angle of approximately 45 °. Therefore, when machining with a cutting depth of 0.3 mm or more, the side cutting edge is damaged and the tool life is shortened. It is clear that

  This invention makes it a subject to reduce the boundary part defect | deletion of the cutting tip which is a problem in the cutting of the difficult-to-cut material on the conditions where a cutting depth exceeds 0.3 mm.

  In order to solve the above problems, in the present invention, the cutting tip is configured as follows. That is, a corner surface where two side surfaces intersect is provided with a cut surface disposed between the two side surfaces to remove the corner, and a ridge line that forms a main cutting edge is formed between the cut surface and the upper surface. In a state where the cutting tip is mounted on the holder of the turning tool, the side cutting edge angle of 60 ° or more and 90 ° or less is inclined at a settable angle.

As the cutting tips, those listed below as specific forms can be considered.
(1) The ridgeline that forms the main cutting edge has a length that enables a cutting depth setting exceeding 0.3 mm.
(2) The ridge line is inclined at an angle at which a side cutting edge angle of 70 ° or more and 90 ° or less can be set in a state where a cutting tip is mounted on a holder of a turning tool.
(3) The cut surface is a flat surface, and the ridge line formed between the cut surface and the upper surface forms a straight line.
(4) The cut surface is a curved surface, and the ridge line formed between the cut surface and the upper surface has an R radius that can set the side cutting edge angle to 60 ° or more and 90 ° or less over the entire ridge line. What you have.
(5) A general-purpose chip having a basic shape of a triangle or a rhombus, and the cut surface is provided in at least one of a plurality of acute corner portions.
(6) The ridge line that forms the main cutting edge has a length corresponding to the depth of possible cutting of 2.0 mm or less.
(7) The cut surface is provided in two planes with respect to the same corner portion so as to form a symmetrical shape in plan view with respect to the bisector of the corner angle.
(8) A negative type chip in which the side surface and the cut surface intersect at an angle of 90 ° with respect to the upper surface.
(9) At least a part involved in cutting is formed of a cBN sintered body containing 35 vol% or more of cBN.

  The cutting tool is mounted on a turning tool holder so that a main cutting edge having a side cutting edge angle of 60 ° or more and 90 ° or less is formed by a ridge line between the cut surface and the upper surface. Constitute. The present invention also provides the cutting tool.

  In addition, the cutting tool is used to perform outer diameter turning on a work material made of any one of a heat-resistant alloy, a Ti alloy, and maraging steel, and this outer diameter turning is performed at a ridge line between the cut surface and the upper surface. There is also provided a cutting method for difficult-to-cut materials, which comprises a main cutting edge having a side cutting edge angle of 60 ° or more and 90 ° or less and performed under a condition where the cutting depth exceeds 0.3 mm.

  In the cutting tip of the present invention, a cut surface for removing a corner is provided at a corner portion where two side surfaces intersect, and a main cutting edge is constituted by a ridge line between the cut surface and the upper surface. The ridge line is inclined at an angle that allows setting of a horizontal cutting edge angle of 60 ° or more and 90 ° or less with a cutting tip mounted on a turning tool holder, and a cutting depth setting exceeding 0.3 mm is set. It has a length that allows it. Therefore, this ridgeline is used as the main cutting edge, and the turning depth is set within a range that does not exceed the machining limit (cutting upper limit) of the ridgeline, so that the side cutting edge angle is always 60 ° throughout the main cutting edge. With this measure, it is possible to effectively suppress wear and breakage of the lateral boundary, which has been a problem in difficult-to-cut material processing particularly when the depth of cut exceeds 0.3 mm. .

  When the side cutting edge angle of the main cutting edge formed by the ridge line is set to 70 ° or more, the effect of preventing the horizontal boundary portion from being lost appears particularly remarkably.

  The cut surface can be a flat surface or a curved surface. The flat cut surface generates a straight ridge line between the upper surface and the upper surface. The straight ridge line is preferable because the cutting edge angle is constant regardless of the variation in the depth of cut, but the curved ridge line formed between the cut surface and the upper surface of the curved surface is also cut across the entire area by increasing the R radius. The blade angle can be 60 ° or more.

  Further, when the present invention is applied to a general-purpose chip having a triangular or rhomboid basic shape and the cut surface is provided at least at one of a plurality of acute corner portions of the chip, cutting is performed using an existing holder. Can be performed, which is economically advantageous.

  However, a chip in which the above-described cut surface is provided at a right-angled corner portion of a square tip or an obtuse corner portion of a rhombus tip is also conceivable. Inserts with the above-mentioned cut surfaces at right-angled corners and obtuse corners are used with a front cutting edge angle between the front side in the tool feed direction (the side where one end of the cut surface is connected) and the top surface. Although the edge angle of the generated ridge line is 60 ° or less, the ridge line at that position does not participate in cutting in the tip of the present invention, so even if such a situation occurs, there is no influence on the lateral boundary portion.

  In addition, since the ridgeline between the cut surface and the upper surface is not preferable because the notch amount of the corner portion due to the cut surface becomes excessive, there is a concern about interference between the holder and the work material. It is preferable to set a length corresponding to the upper limit cutting depth within the limit with a cutting depth of about 0 mm as a limit.

  In addition, the cutting surface in which the cut surface is provided in two planes with a symmetrical shape in plan view with respect to the bisector of the corner angle with respect to the same corner portion, reverses the feeding direction. In this way, the two main cutting edges of the same corner portion can be used in two portions, which is excellent in economic efficiency.

  Moreover, when the present invention is applied to the negative tip, the cutting edge strength is higher than that applied to the positive tip, and the fracture resistance of the lateral boundary portion may be increased.

  In addition, the cutting tip in which the part involved in cutting is formed of a cBN sintered body containing 35 vol% or more of cBN has a lateral boundary portion as compared with a cBN sintered body or cemented carbide having a cBN content of 35 vol% or less. Deficiencies are further reduced and durability is increased.

  In addition, according to the cutting tool of the present invention configured by mounting the cutting tip of the present invention on the holder and the cutting method of the present invention using the same, the characteristics of the cutting tip are utilized and the lateral boundary portion of the cutting edge is utilized. Wear and chipping are reduced and tool life is extended.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 10 of the accompanying drawings. 1 and 2 show an embodiment of the cutting tip of the present invention. This cutting tip 1 is a tip having a rhombus whose corner angle θ of an acute corner portion is 80 ° as a basic shape (ISO-standard C type), and includes an upper surface 2, a lower surface 3, four side surfaces 4, and the present invention. It has a cut surface 5 to be characterized.

  The cut surface 5 is provided on one acute angle corner side. A part of the cut surface 5 is composed of a cBN sintered body 6, and only an area close to the minimum of the part involved in cutting is a chip having an economically preferable structure made of the cBN sintered body 6. .

  The cBN sintered body 6 is attached by brazing to a base metal 7 formed of cemented carbide or high speed steel, and the region formed by the cBN sintered body 6 of the cut surface 5 and the upper surface 2. Is used as the main cutting edge with a side cutting edge angle.

  Here, the cut surface 5 is γ1 = 25 ° with respect to a line obtained by extending one of the side surfaces 4 constituting the acute corner portion (the side surface on the side where the ridge line 10 that becomes the front cutting edge is formed between the upper surface 2). The surface has an inclination of. Further, the turning tool is set so that the ridgeline 10 between the side surface 4 and the upper surface 2 of the tip is a front cutting edge, and the front cutting edge angle β of the blade is, for example, 5 °. When attached to the holder, the ridgeline 9 is provided with a length capable of processing the required cutting depth with the ridgeline 9 as the main cutting edge. The lower limit length of the ridge line 9 is preferably a length that allows the cutting depth d to be set to 0.3 mm or more.

  The cut surface 5 may be a flat cut surface (see FIG. 2) or a curved cut surface. The flat cut surface generates a straight ridge line 9 (see the solid line ridge line in FIG. 1) between the upper surface 2 and the curved cut surface has a curved ridge line 9 as shown by a one-dot chain line in FIG. It is formed between the upper surface 2. The sharp edge generated at the intersection of the cut surface 5 and the side surface 4 is preferably removed by forming a curved surface having a small R radius.

  In this cutting tip 1, assuming that the front cutting edge angle β is set to 5 ° as described herein, the ridge line 9 is inclined by γ = 20 ° with respect to the reference line A parallel to the axis of the workpiece. At this time, the lateral cutting edge angle α of the ridge line 9 is obtained by an equation of α = (90 ° −γ) and is 70 °.

  Reference numeral 11 in FIGS. 1 and 2 denotes a mounting hole provided in the base metal 7, which is provided as necessary.

  3 shows an example in which the side cutting edge angle α is 60 °, and FIG. 4 shows an example in which the side cutting edge angle α is 85 °. These basic shapes are rhombuses having a corner angle θ of 80 ° at an acute angle corner portion, and are horizontal cutting edge angles when it is assumed that the front cutting edge angle is set to 5 °.

  The lower limit of the front cutting edge angle β is generally set to about 3 to 5 °. Therefore, the upper limit of the side cutting edge angle α is theoretically 90 °, but it is considered that about 85 to 87 ° is selected in practical use.

  As shown in FIGS. 5 to 7, two cut surfaces 5 can be provided on the same corner portion in a symmetric shape in plan view with respect to the bisector CL of the corner angle θ. Further, each of the triangular, quadrangular, and rhombus chips can be provided with cut surfaces 5 at a plurality of corner portions.

  FIG. 8 shows a cutting tool (bite) according to the present invention constructed by detachably mounting a cutting tip 1 whose left and right sides are opposite to those in FIG. In this cutting tool 20, a main cutting edge 22 having a side cutting edge angle of 60 ° or more and 90 ° or less is formed by a ridge line 9 between the cutting surface 5 and the upper surface 2 of the chip. The outer diameter can be turned over 0.3 mm. Reference numeral 23 denotes a front cutting edge, which has a front cutting edge angle of β.

  9 and 10 show an example of outer diameter turning by the cutting tool 20 of FIG. In this way, the above-described ridge line 9 becomes the main cutting edge 22 and is cut into the work material W. At this time, the lateral cutting edge angle α of the main cutting edge 22 is set to 60 ° or more, and the cutting depth d is set to 0.3 mm or more to perform the outer diameter turning of the work material W.

  The work material W at this time is, for example, a heat-resistant alloy, a Ti alloy, or maraging steel. By cutting the work material of the material, the effect of suppressing wear and chipping of the lateral boundary portion of the cutting edge, which is the object of the present invention, is exhibited, and the life of the chip is extended.

The contents of the test for confirming the effect of the present invention are described below.
Example 1
A cBN sintered body having a cBN content of 70 vol% is prepared, processed, and joined to a base metal, and each of the two side surfaces for producing a corner at an acute corner portion having a corner angle of 80 ° as shown in FIG. A C-shaped cutting tip is produced in which a straight ridge line with an angle is generated by providing a cut surface. A plurality of chips having different cutting edge angles are prepared (invention product and comparison product). For comparison, a cutting tip having an ISO standard CNMA120204 shape is also prepared.

Next, these cutting tips are mounted on the holder, and the tool life is evaluated by cutting the workpiece on the outer diameter under the following conditions. The evaluation here is performed by a method in which the tool life is determined when the wear amount on the flank surface exceeds 0.2 mm, or when the tool edge is missing, and the length of the cutting time until the life is compared. The test results are shown in Table 1.
Work material: Ni-base heat-resistant alloy {Inconel 718 (trademark of Special Metal Co.)} Outside diameter turning Holder: PCLNR2525 (ISO)
・ Cutting speed: V = 300 m / min
・ Feed: f = 0.12mm / rev
-Depth of cut: listed in Table 1-Coolant: Yes

-General comment-
・ Comparison of sample Nos. 1 to 4 with a cutting depth of 0.8 mm unified Sample No. 1 (comparative product) with a side cutting edge angle of less than 60 ° at the time of cutting has an edge defect at the beginning of cutting. It can be seen that the sample No. 2 (invention product) has a long life, while the cutting time until the breakage is significantly extended while the life is reached. Samples Nos. 3 and 4 (which are also invented products) are worn out without loss and have reached the end of their lives, and it can be seen that this also enables long-term, stable cutting.

・ Comparison of sample Nos. 5 to 9 with a cutting depth of 0.4 mm unified Sample No. 5 (comparative product) using a cutting tip of ISO standard CNMA120204 is processed under these conditions as shown in Table 1. In this case, the side cutting edge angle is 42 °. For this reason, a cutting edge defect occurs in the initial stage of cutting, resulting in a short life. Sample No. 6 (also a comparative product) having a side cutting edge angle of less than 60 ° at the time of cutting also has a life due to chipping at the beginning of cutting. On the other hand, Sample No. 7 (invention product) has a significantly longer cutting time until failure and it can be seen that a long life is obtained. Samples Nos. 8 and 9 (invention products) are worn out without missing and have reached the end of their lives, and it can be seen that this also has a long life and can be stably cut for a long time.
・ Verification of the relationship between the depth of cut and the side cutting edge angle Sample No. 11 and Sample No. 6 (both are comparative products) have the same horizontal cutting edge angle of 45 °. 12 minutes long. In contrast, sample No. 6 (comparative product) has an extremely short cutting time of 4 minutes. From this, if the cutting depth is up to 0.2 mm, a long life can be obtained even when the side cutting edge angle is 60 ° or less, and setting the side cutting edge angle to 60 ° or more means that the cutting depth is 0.2 mm or more. It turns out that it is effective. Actually, sample Nos. 2 to 4 (invention product) have a life extension effect of 10 minutes or more compared to sample No. 1, and similarly, sample Nos. 7 to 9 (invention) compared to sample No. 5 Product) also has a life extension effect of 10 minutes or more. It can also be seen that the effect of the invention increases as the side cutting edge angle increases.

-Example 2-
A cBN sintered body having a cBN content of 90 vol% was prepared and processed, and this was joined to a base metal, and an angle as provided in the chip of FIG. 1 was provided at one corner of a square chip (S type). A straight ridge line (a ridge line that becomes a main cutting edge) is a chain tip in FIG. 1 instead of the straight ridge line in one place of a cutting tip formed by providing a cut surface and a corner portion of a square tip (S type) A cutting tip provided with curved ridgelines (three types with different R radii of the curves) as shown is produced.

Next, these cutting tips are mounted on the holder, and the tool life is evaluated by cutting the workpiece on the outer diameter under the following conditions. The evaluation here is performed by a method in which when the wear amount of the flank exceeds 0.3 mm, or when the tool edge is missing, the tool life is taken and the length of the cutting time until the life is compared. The test results are shown in Table 2.
Work material: Maraging steel outer diameter turning Holder: PSDNN2525 (ISO)
・ Cutting speed: V = 150 m / min
・ Feed: f = 0.15mm / rev
-Depth of cut: d = 0.8 mm
・ Coolant: Available

-General comment-
・ Comparison of sample Nos. 14 to 16 with the main cutting edge made straight Sample No. 14 (comparative product) whose cutting edge angle during cutting is less than 60 ° has a cutting edge defect at the beginning of cutting and has a lifetime. On the other hand, it can be seen that Sample Nos. 15 and 16 (invention product) have a significantly longer cutting time until the defect and can stably cut for a long time.
・ Comparison of sample Nos. 17 to 20 whose main cutting edge is composed of a curved ridgeline Sample Nos. 17 and 18 (comparative products) with a side cutting edge angle of less than 60 ° have a short cutting time and a short life. On the other hand, sample Nos. 19 and 20 (invention products) with a side cutting edge angle of 60 ° or more were worn without loss and reached the end of their lives, enabling long-life and stable cutting for a long time. I understand that.
・ Verification of influence of side cutting edge angle From the test results of sample Nos. 15, 16, 19, and 20 (invention), if the side cutting edge angle of 60 ° or more is secured, the main cutting edge can be straight or curved. It can be seen that the effect of extending the life can be obtained.

-Example 3-
A cBN sintered body having a cBN content of 90 vol% is prepared, processed, and joined to a base metal, and each of the two side surfaces creating a corner at an acute corner portion having a corner angle of 80 ° as shown in FIG. A C-shaped cutting tip is produced in which a straight ridge line with an angle is generated by providing a cut surface. A plurality of chips having different cutting edge angles are prepared (invention product and comparison product). For comparison, a cutting tip having an ISO standard CNMA120204 shape is also prepared.

Next, these cutting tips are mounted on a holder, and an outer diameter cutting test of 3-1 to 3-3 below is performed to evaluate the tool life. The results are shown in Table 3.
(Test 3-1)
Work material: Ni-base heat-resistant alloy {Inconel 718 (trademark of Special Metal Co.)} Outside diameter turning Holder: PCLNR2525 (ISO)
・ Cutting speed: V = 180 m / min
・ Feed: f = 0.10mm / rev
-Depth of cut: d = 0.60mm
-Coolant: Existence In this evaluation, the tool life is determined when the amount of wear on the flank surface exceeds 0.2 mm or when the tool edge is missing, and the length of the cutting time until the life is compared.
(Test 3-2)
Work material: Ti-6Al-4V outer diameter turning Holder: PCLNR2525 (ISO)
・ Cutting speed: V = 120 m / min
・ Feed: f = 0.12mm / rev
・ Cut depth: d = 0.40mm
-Coolant: Existence The evaluation here is performed when the wear amount on the flank surface exceeds 0.25 mm or when the tool edge is missing, and the tool life is compared, and the length of the cutting time until the life is compared.
(Test 3-3)
・ Work material: FC300 outer diameter turning ・ Holder: PCLNR2525 (ISO)
・ Cutting speed: V = 1000 m / min
・ Feed: f = 0.13mm / rev
-Depth of cut: d = 0.35mm
-Coolant: Existence In this evaluation, the tool life is determined when the amount of wear on the flank surface exceeds 0.05 mm, or when the tool edge is missing, and the length of the cutting time until the life is compared.

-General comment-
・ Comparison of sample Nos. 21 to 26 From sample Nos. 21 and 22, when the work material is a Ni-based heat-resistant alloy, sample No. 21 whose cutting edge angle during cutting is less than 60 ° is the cutting edge at the beginning of cutting. It can be seen that sample No. 22 with a side cutting edge angle of 70 ° can be stably cut for a long time until it reaches the end of its life due to wear, while the defect occurs and the lifetime is reached. The same applies when the work material is a Ti alloy, which can be seen from the test results of Samples Nos. 23 and 24.
Furthermore, from sample Nos. 25 and 26, when the work material is FC300 (this is not a difficult-to-cut material), the tool damage status and the tool life are equivalent without depending on the side cutting edge angle. From this, it can be seen that setting the side cutting edge angle to 60 ° or more is effective in cutting difficult-to-cut materials.

The top view which shows one form of the cutting tip of this invention 1 is a perspective view of the cutting tip of FIG. The top view which shows the outline | summary of the other form of the cutting tip of this invention The top view which shows the outline | summary of the further another form of the cutting tip of this invention The top view which shows the outline | summary of the further another form of the cutting tip of this invention The top view which shows the outline | summary of the further another form of the cutting tip of this invention The top view which shows the outline | summary of the further another form of the cutting tip of this invention The top view which shows one form of the cutting tool of this invention The figure which shows the outer-diameter turning method by the cutting tool of this invention The figure which expanded the principal part of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cutting tip 2 Upper surface 3 Lower surface 4 Side surface 5 Cut surface 6 cBN sintered body 7 Base metal 9 Ridge line which becomes main cutting edge 10 Ridge line which becomes front cutting edge 11 Mounting hole 20 Cutting tool 21 Holder 22 Main cutting edge 23 Front cutting edge W Work material A Reference line CL parallel to the axis of the work material CL Corner angle bisector α Side cutting edge angle β Front cutting edge angle θ Corner angle γ1 Inclination angle γ of the cut surface relative to one side γ Reference line of ridgeline 9 Inclination angle d with respect to line A Cutting depth

Claims (12)

  At the corner where the two side surfaces (4, 4) intersect, a cut surface (5) is provided between the side surfaces (4, 4) to remove the corner, and the cut surface (5) and the upper surface (2) A ridge line (9) that forms the main cutting edge is formed in between, and the ridge line (9) sets a side cutting edge angle (α) of 60 ° or more and 90 ° or less with the cutting tip mounted on the turning tool holder. Cutting tip inclined at possible angle.   The cutting tip according to claim 1, wherein the ridge line (9) has a length that enables a cutting depth setting exceeding 0.3 mm.   The said ridgeline (9) inclines at the angle which can set the side cutting edge angle ((alpha)) of 70 degrees or more and 90 degrees or less in the state which mounted | wore the holder of the turning tool with the cutting tip. Cutting tips.   The said cut surface (5) is a plane, The said ridgeline (9) formed between the cut surface (5) and upper surface (2) has comprised the straight line in any one of Claims 1-3. Cutting tips.   The cut surface (5) is a curved surface, and the ridge line (9) formed between the cut surface (5) and the upper surface (2) has a side cutting edge angle (α) of 60 ° or more and 90 ° or less. The cutting tip according to any one of claims 1 to 3, wherein the cutting tip has an R radius that can be set to 1.   The cutting tip according to any one of claims 1 to 5, wherein the basic shape is a general-purpose tip having a triangular or rhombus shape, and the cut surface (5) is provided in at least one of a plurality of acute corner portions.   The cutting tip according to any one of claims 1 to 6, wherein the ridge line (9) forming the main cutting edge has a length corresponding to a cutting depth of 2.0 mm or less.   The cut surface (5) is provided in two planes with a symmetrical shape in plan view with respect to the same bisector (CL) of the corner angle (θ) with respect to the same corner portion. The cutting tip according to any one of the above.   The cutting tip according to any one of claims 1 to 8, wherein the side surface (4) and the cut surface (5) are configured as a negative type tip that intersects the upper surface (2) at an angle of 90 °.   The cutting tip according to any one of claims 1 to 9, wherein at least a portion involved in cutting is formed of a cBN sintered body containing 35 vol% or more of cBN.   The cutting tip (1) according to any one of claims 1 to 10, having a side cutting edge angle of 60 ° or more and 90 ° or less by a ridge line (9) between the cut surface (5) and the upper surface (2). The cutting tool attached to the holder (21) of the turning tool in a state where the main cutting edge (22) to be formed is formed.   Using the cutting tool (20) according to claim 11, an outer diameter turning is performed on a work material made of any one of a heat-resistant alloy, a Ti alloy, and maraging steel, and the outer diameter turning is performed on the cut surface ( 5) and the ridgeline (9) between the upper surface (2) and the main cutting edge (22) having a side cutting edge angle of 60 ° or more and 90 ° or less and the cutting depth exceeds 0.3 mm The cutting method of difficult-to-cut materials performed below.

Images