Cutting inserts and cutting tools with cutting inserts mounted on them

Abstract

According to one embodiment of the present invention, a cutting insert includes an upper surface, a lower surface, a side surface, a cutting edge, and a fastening hole. The cutting edge includes a main cutting edge, a cutting tip R-shaped portion connected to the main cutting edge, and a secondary cutting edge connected to the cutting tip R-shaped portion. The upper surface includes a back edge adjacent to the cutting edge, an inclined surface sloping downward from the back edge, and a bottom of the upper surface extending from the inclined surface. A first protrusion connected to the back edge of the main cutting edge is formed on the inclined surface of the main cutting edge at the portion where the inclined surface of the cutting tip R-shaped portion terminates. A second protrusion connected to the back edge of the secondary cutting edge is formed on the inclined surface of the secondary cutting edge at the portion where the inclined surface of the cutting tip R-shaped portion terminates. There is no protrusion on the inclined surface of the cutting tip R-shaped portion.

Description

Technical Field

[0001] This invention relates to a cutting blade and a cutting tool on which the cutting blade is mounted. Background Technology

[0002] Typically, cutting inserts are fixed to cutting tools mounted on machine tools and used to cut workpieces such as machine parts made of iron, non-ferrous metals, non-metallic materials, etc.

[0003] This cutting insert includes an upper surface, a lower surface facing the opposite direction, a side surface connecting the upper and lower surfaces to each other, and a cutting edge that forms the boundary between the upper and side surfaces and cuts the workpiece.

[0004] at the same time, Figure 12 A cutting blade disclosed in Japanese Patent No. 6241695 is shown. For reference, Figure 12 Corresponding to the aforementioned Japanese patent Figure 1 For ease of explanation, the reference numerals used in the drawings of this Japanese patent are used as is without modification; however, even if these reference numerals overlap with the same reference numerals used in this invention, they do not refer to the same elements.

[0005] The cutting insert 1 includes at least one cutting edge 8 formed at the intersection between the inclined surface 6 and the flank face 7, and at least one ridge 12. The cutting edge 8 includes a cutting edge portion 9 extending along the corner portion 5 and a straight cutting edge portion 10 connected thereto. Furthermore, the ridge 12 protrudes on the inclined surface 6 and extends from the inner inclined surface of the cutting edge portion 9 of the corner portion 5 toward the inner inclined surface of the straight cutting edge portion 10.

[0006] Meanwhile, in the relevant cutting insert 1, since the ridge 12 is positioned lower than the cutting edge 8, it has limitations in preventing high-pressure chips generated in the machining unit from being elongated as they flow towards the secondary cutting edge. Furthermore, this structure also suffers from insufficient cutting oil supply from the outside to the machining unit, resulting in poor heat dissipation. Summary of the Invention

[0007] Technical issues

[0008] The present invention was made to solve the above-mentioned problems, and the object of the present invention is to provide a cutting insert that can prevent damage to the cutting edge by promoting chip curling and can also improve machining life by increasing heat dissipation, and a cutting tool equipped with the cutting insert.

[0009] Technical solution

[0010] To achieve the above objectives, the cutting insert according to an embodiment of the present invention is characterized by comprising an upper surface, a lower surface, a side surface, a cutting edge, and a fastening hole, wherein the cutting edge comprises a main cutting edge, a tool tip R-shaped portion connected to the main cutting edge, and a secondary cutting edge connected to the tool tip R-shaped portion; the upper surface comprises a back edge adjacent to the cutting edge, an inclined surface sloping downward from the back edge, and a bottom surface of the upper surface extending from the inclined surface; the back edge comprises a back edge of the main cutting edge adjacent to the main cutting edge, a back edge of the tool tip R-shaped portion connected to the back edge of the main cutting edge and adjacent to the tool tip R-shaped portion, and a back edge of the secondary cutting edge connected to the back edge of the tool tip R-shaped portion and adjacent to the secondary cutting edge; the inclined surface comprises a back edge of the main cutting edge adjacent to the tool tip R-shaped portion and adjacent to the secondary cutting edge; and the inclined surface comprises a back edge of the tool tip R-shaped portion connected to the back edge of the tool tip R-shaped portion and adjacent to the secondary cutting edge. The main cutting edge has a downward-sloping main cutting edge inclined surface, a tool tip R-shaped inclined surface connected to the main cutting edge inclined surface and inclined downward from the back of the tool tip R-shaped part, and a secondary cutting edge inclined surface connected to the tool tip R-shaped part and inclined downward from the back of the secondary cutting edge. Each of these surfaces has a first protrusion and a second protrusion. The first protrusion is connected to the back of the main cutting edge and is formed on the main cutting edge inclined surface at the terminating part of the tool tip R-shaped inclined surface. The second protrusion is connected to the back of the secondary cutting edge and is formed on the secondary cutting edge inclined surface at the terminating part of the tool tip R-shaped inclined surface. There are no protrusions on the tool tip R-shaped inclined surface.

[0011] Furthermore, the first protrusion and the second protrusion are characterized by having the same height as the back of the main cutting edge and the back of the secondary cutting edge.

[0012] Furthermore, it is characterized by multiple recesses and multiple protrusions being alternately connected to each other on the bottom of the upper surface, and the height of the multiple protrusions decreasing sequentially and the angle with the horizontal plane decreasing as they move away from the secondary cutting edge.

[0013] Furthermore, it is characterized in that the height of each of the plurality of protrusions gradually increases from the main cutting edge toward the fastening hole.

[0014] Furthermore, the upper surface bottom is characterized by including a blade tip R-shaped portion bottom connected to the inclined surface of the blade tip R-shaped portion and a cutting edge portion bottom in which a plurality of recesses and a plurality of protrusions are formed, and the blade tip R-shaped portion bottom is formed to be higher than the plurality of protrusions.

[0015] Furthermore, the blade tip R-shaped portion is characterized by having a first groove at its bottom, and each of the plurality of protrusions having a second groove at its end, wherein the radius of curvature of the first groove is greater than the radius of curvature of the second groove.

[0016] Furthermore, it is characterized in that the width of the plurality of recesses increases as they approach the main cutting edge, and the dimensions of the relative widths of the plurality of recesses increase as they move away from the R-shaped portion at the tool tip.

[0017] Furthermore, it is characterized by including a boss portion surrounding the fastening hole, wherein the boss portion includes a groove portion, one end of which faces the secondary cutting edge and the other end of which faces the main cutting edge.

[0018] The aforementioned cutting blade is mounted on the cutting tool of the present invention.

[0019] Invention Effects

[0020] The cutting insert according to an embodiment of the present invention having the above-described structure has the following effects.

[0021] According to the current embodiment, a first protrusion and a second protrusion in the form of a convex shape connected to the back of the cutting edge are provided to prevent high-pressure chips from flowing to the secondary cutting edge and to prevent the secondary cutting edge from being squeezed under high pressure, thereby preventing chips from being elongated to the secondary cutting edge and thus preventing the cutting tool life from being shortened due to crater wear and plastic deformation.

[0022] Furthermore, the bottom of the R-shaped portion at the tool tip is positioned higher than the bottom of the cutting edge, causing the chip to bend outwards towards the machining area. This results in a relatively larger chip curl radius at the bottom of the R-shaped portion at the tool tip compared to the bottom of the cutting edge, and allows the chip to naturally orient itself as it curls. Additionally, to prevent chip stretching, the protrusion extends further upwards as it moves away from the main cutting edge, thereby reducing the chip curl radius.

[0023] Furthermore, according to the current embodiment, a groove with a predetermined radius of curvature is formed on the portion where the chips flow, allowing the chips to flow naturally and make surface contact with the bottom of the upper surface, thus preventing localized wear, and reducing the machining load as the chips curl up when they come into contact with the three portions including the cutting edge, the inclined surface, and the bottom of the upper surface (groove). In addition, by generating chip curling via the groove, long chips can be prevented.

[0024] At the same time, it goes without saying that the present invention includes other effects that, although not explicitly stated, can be expected from the above-described structure. Attached Figure Description

[0025] Figure 1 This is a perspective view of a cutting blade according to an embodiment of the present invention.

[0026] Figure 2 yes Figure 1 A plan view of the cutting insert.

[0027] Figure 3 (a) is in Figure 2 A cross-sectional view taken along the AA direction. Figure 3 (b) is a schematic diagram showing the flow of chips.

[0028] Figure 4 (a) is Figure 1 A magnified view of a portion of the cutting blade. Figure 4 (b) is in Figure 4 (a) is a cross-sectional view taken along the BB direction.

[0029] Figure 5 yes Figure 1 A partial three-dimensional view of the cutting insert in the direction of the R-shaped part at the tip and the main cutting edge.

[0030] Figure 6 It is shown schematically. Figure 1 A view of the radii of curvature of the first and second grooves of the cutting blade.

[0031] Figure 7 (a) is a schematic diagram showing chip curling in a cutting blade without a second groove. Figure 7 (b) is shown Figure 1 A schematic diagram of chip curling in a cutting tool.

[0032] Figure 8 In order to explain Figure 1 The view provided is based on the multiple recesses of the cutting blade.

[0033] Figure 9 In order to explain Figure 1 The view provided is of the groove of the cutting blade.

[0034] Figure 10 It shows the flow Figure 9 A schematic diagram of the cutting oil in the groove.

[0035] Figure 11 It is shown Figure 1 A view of the cutting insert mounted on the cutting tool.

[0036] Figure 12 This is a view of the relevant cutting insert. Detailed Implementation

[0037] Preferred embodiments of the invention will be described in detail below with reference to the accompanying drawings, which will be apparent to those skilled in the art. However, it should be understood that the invention can be implemented in various other forms and should not be construed as limited to the specific examples described herein.

[0038] like Figure 1 As shown, the cutting insert according to an embodiment of the present invention includes an upper surface 1, a lower surface 2, a side surface 3, a cutting edge 4, and a fastening hole 5. For reference, the cutting insert may be a single-sided cutting insert for turning, wherein the upper surface 1 serves as the cutting surface and the lower surface 2 serves as the mounting surface of the cutting tool. Furthermore, as... Figure 11As shown, the cutting insert 100 can be fixed to the cutting tool h and used by fastening bolts.

[0039] like Figure 2 As shown, the cutting blade can have an approximately parallelogram shape and can be symmetrical to each other with respect to the imaginary center line C extending along the center of the fastening hole 5 and the center of the opposite corner.

[0040] like Figure 2 As shown, the cutting edge 4 includes a main cutting edge 41, a tool tip R-shaped portion 42 connected to the main cutting edge 41, and a secondary cutting edge 43 connected to the tool tip R-shaped portion 42.

[0041] The upper surface 1 includes a back edge 11 adjacent to the cutting edge 4, an inclined surface (cutting surface) 12 that slopes downward from the back edge 11 (in the direction from the upper surface to the lower surface), and a bottom surface 13 extending from the inclined surface 12.

[0042] Specifically, the back edge 11 includes a main cutting edge back edge 111 adjacent to the main cutting edge 41, a tool tip R-shaped part back edge 112 connected to the main cutting edge back edge 111 and adjacent to the tool tip R-shaped part 42, and a secondary cutting edge back edge 113 connected to the tool tip R-shaped part back edge 112 and adjacent to the secondary cutting edge 43.

[0043] The inclined surface 12 includes a main cutting edge inclined surface 121 that is inclined downward from the back of the main cutting edge 111, a tool tip R-shaped inclined surface 122 that is connected to the main cutting edge inclined surface 121 and is inclined downward from the back of the tool tip R-shaped edge 112, and a secondary cutting edge inclined surface 123 that is connected to the tool tip R-shaped inclined surface 122 and is inclined downward from the back of the secondary cutting edge 113.

[0044] Specifically, according to this embodiment, such as Figure 2 As shown, a first protrusion 124, connecting to the back edge 111 of the main cutting edge, is formed on the inclined surface 121 of the main cutting edge at the portion terminating at the tip R-shaped inclined surface 122, and a second protrusion 125, connecting to the back edge 113 of the secondary cutting edge, is formed on the inclined surface 123 of the secondary cutting edge at the portion terminating at the tip R-shaped inclined surface 122. Furthermore, there are no protrusions on the tip R-shaped inclined surface 122.

[0045] The downward tilt angle 'a' of the first protrusion 124 and the second protrusion 125 is greater than the forward tilt angle 'b' (see...). Figure 3 (a)). Furthermore, the first protrusion 124 and the second protrusion 125 preferably have the same height (based on the lower surface) as the back of the main cutting edge 111 and the back of the secondary cutting edge 113, that is, the protrusions preferably have a height such that the protrusions do not protrude beyond the back of the cutting edge.

[0046] For reference, the chips generated during the machining of large workpieces produce high temperatures and pressures. Effective chip removal can ensure a longer cutting tool life. However, if high-pressure chips continuously flow towards or compress the secondary cutting edge, it leads to long crater wear, subsequently causing plastic deformation, damaging the flank face of the secondary cutting edge and shortening the cutting tool's life. To prevent this, such as... Figure 3 As shown in (b), according to this embodiment, a first protrusion 124 and a second protrusion 125 in the form of a convex shape connected to the back of the cutting edge 11 are provided to prevent high-pressure chips P from flowing to the secondary cutting edge and to prevent the secondary cutting edge from being squeezed under high pressure, thereby preventing chips from being stretched to the secondary cutting edge, and thus preventing the cutting tool life from being shortened due to crater wear and plastic deformation.

[0047] At the same time, such as Figure 4 As shown, according to this embodiment, a plurality of recesses 131 and a plurality of protrusions 132 are alternately connected to each other on the bottom surface 13 of the upper surface.

[0048] As the distance from the secondary cutting edge 43 increases, the height of the plurality of protrusions 132 (based on the horizontal plane, for example, based on the lower surface) decreases sequentially (h1>h2>h3) and the angle with the horizontal plane decreases (θ1>θ2>θ3).

[0049] The height of each of the multiple protrusions 132 gradually increases as it approaches the fastening hole 5 from the main cutting edge 41. Similarly, the height of the multiple protrusions 132 located on the side of the secondary cutting edge 43 also gradually increases as it approaches the fastening hole 5.

[0050] Furthermore, the upper surface bottom 13 includes a blade tip R-shaped portion bottom 133 connected to the blade tip R-shaped inclined surface 122 and a cutting edge portion bottom 134 in which a plurality of recesses 131 and a plurality of protrusions 132 are formed. In addition, the blade tip R-shaped portion bottom 133 is formed to be higher than the plurality of protrusions 132.

[0051] For reference, if the chips generated during the machining process continue to remain in the machining area, the high temperature and high pressure will concentrate on the tip R-shaped portion 42 of the cutting insert, causing the cutting insert to undergo rapid crater wear or plastic deformation.

[0052] According to one embodiment, with the above-described configuration, the bottom 133 of the R-shaped portion at the tool tip is positioned higher than the bottom 134 of the cutting edge portion, such that the bending direction of the chip points outward from the machining area. Therefore, the curling radius of the chip on the side of the bottom 133 of the R-shaped portion at the tool tip is relatively larger than the curling radius on the side of the bottom 134 of the cutting edge portion (R1 > R2), and the chip naturally orients itself during curling. Furthermore, to prevent chip stretching, the protrusion 124 extends further upward as it moves away from the main cutting edge 41, thereby reducing the curling radius of the chip.

[0053] At the same time, such as Figure 6 As shown, the bottom 133 of the R-shaped portion of the blade tip has a first groove 1331, and each of the plurality of protrusions 132 has a second groove 1321 at its end. In this example, the radius of curvature of the first groove 1331 is greater than the radius of curvature of the second groove 1321.

[0054] For reference, when the bottom 13 of the upper surface (the bottom of the chip breaker groove) is flat, the chip may make point contact with the bottom 13 of the upper surface (see...). Figure 7 (a)), and localized wear may occur in the point contact area, where stretched chips may be generated, thereby increasing the machining load. Conversely, according to the embodiment described, grooves 1331 and 1332 with predetermined radii of curvature are formed on the chip flow portion, allowing the chips to flow naturally and make surface contact with the bottom of the upper surface 13 (see...). Figure 7 (b) Therefore, localized wear is prevented, and the machining load is reduced as the chip curls up when it comes into contact with the three parts, including the cutting edge, the inclined surface, and the bottom of the upper surface (groove). In addition, long chips are prevented by generating chip curling via the groove.

[0055] like Figure 8 As shown, according to the embodiment, the width of the plurality of recesses 131 increases as they approach the main cutting edge 41 (Wb > Wa), and the relative width of the plurality of recesses 131 increases as they move away from the tool tip R-shaped portion 42 (Wb > Wc).

[0056] With the above-described structure, cutting oil can be fully penetrated into the multiple recesses 131 on the bottom of the upper surface 13, thus effectively cooling the hot chips and preventing the transfer of cutting heat to the entire cutting insert. Furthermore, since the temperature of the cutting heat gradually increases with approach to the cutting edge 4, the width of the recesses 131 can be formed to increase with approach to the cutting edge 4, thereby allowing a larger amount of cutting oil to easily penetrate.

[0057] As described above, the cutting insert according to the embodiment substantially prevents the generation of high temperatures by rapidly cooling the high-heat chips, and also promotes chip curling due to the bending stress generated during chip cooling. Furthermore, the cross-section of the chip forms a wavy shape similar to the shape of the bottom of the upper surface in the cutting insert, thereby generating bending stress and promoting chip curling.

[0058] like Figure 9 As shown, the cutting insert has a boss 6 surrounding the fastening hole 5. Furthermore, the boss 6 includes an elongated groove 61 formed therein, one end of which faces the secondary cutting edge 43 and the other end of which faces the main cutting edge 41.

[0059] like Figure 8As shown, when cutting oil L is introduced from the outside, the cutting insert helps to release cutting heat by increasing the contact area with the cutting oil L through multiple recesses 131 at the bottom of the upper surface 13. Furthermore, the cutting oil L, heated to a high temperature while flowing freely between the primary cutting edge 41 and the secondary cutting edge 43 during direct machining, is discharged towards the secondary cutting edge 43, and cold cutting oil is allowed to be reintroduced into the machining section, thereby preventing the chips from generating high cutting heat and also preventing the transfer of cutting heat from the cutting insert.

[0060] Although the invention has been described with reference to some examples herein, the invention should not be limited to these examples, and various other modifications and variations made by those skilled in the art based on the basic concepts of the invention are also within the scope of the appended claims.

[0061] Industrial applicability

[0062] This invention is applicable to cutting inserts and cutting tools on which the cutting inserts are mounted.

Claims

1.A cutting insert comprising an upper surface, a lower surface, a side surface, a cutting edge, and a fastening hole, wherein: the cutting edge comprises a main cutting edge, a nose R portion connected with the main cutting edge, and a sub cutting edge connected with the nose R portion; the upper surface comprises a land adjacent to the cutting edge, an inclined surface inclined downward from the land, and an upper surface bottom portion extending from the inclined surface; the land comprises a main cutting edge land adjacent to the main cutting edge, a nose R portion land connected with the main cutting edge land and adjacent to the nose R portion, and a sub cutting edge land connected with the nose R portion land and adjacent to the sub cutting edge; the inclined surface comprises a main cutting edge inclined surface inclined downward from the main cutting edge land, a nose R portion inclined surface connected with the main cutting edge inclined surface and inclined downward from the nose R portion land, and a sub cutting edge inclined surface connected with the nose R portion inclined surface and inclined downward from the sub cutting edge land; and first and second protrusions are respectively formed, wherein the first protrusion is connected with the main cutting edge land and is formed on the main cutting edge inclined surface at a portion where the nose R portion inclined surface terminates, the second protrusion is connected with the sub cutting edge land and is formed on the sub cutting edge inclined surface at a portion where the nose R portion inclined surface terminates, and there is no protrusion on the nose R portion inclined surface, wherein a plurality of recesses and a plurality of protrusions are alternately connected with each other on the upper surface bottom portion, wherein the upper surface bottom portion comprises a nose R portion bottom portion connected with the nose R portion inclined surface, and a cutting edge portion bottom portion in which the plurality of recesses and the plurality of protrusions are formed, and the nose R portion bottom portion is formed higher than the plurality of protrusions, wherein the nose R portion bottom portion comprises a first groove, and the plurality of protrusions each comprise a second groove at an end portion, and the radius of curvature of the first groove is greater than the radius of curvature of the second groove. The first and second protrusions have the same height as the main cutting edge land and the sub cutting edge land. The height of the plurality of protrusions decreases in order and the angle with a horizontal plane becomes smaller as it is farther away from the sub cutting edge. The height of each of the plurality of protrusions gradually increases from the main cutting edge toward the fastening hole. The width of the plurality of recesses becomes larger as it is closer to the main cutting edge, and The size of the relevant width of the plurality of recesses becomes larger as it is farther away from the nose R portion. 6.The cutting insert according to claim 1, comprising a boss portion surrounding the fastening hole, wherein the boss portion comprises a groove portion, one end portion of which faces the sub cutting edge and the other end portion of which faces the main cutting edge. 7.A cutting tool on which the cutting insert according to claim 1 is mounted. ​ ​ ​ 2. The cutting insert according to claim 1, wherein, ​ 3. The cutting insert according to claim 1, wherein, ​ 4. The cutting insert according to claim 3, wherein, ​ 5. The cutting insert according to claim 3, wherein, ​ ​ ​ ​

Images