Cutting insert and cutting tool equipped with the cutting insert

Abstract

The cutting insert according to an embodiment of the present invention is a double-sided cutting insert, which includes an upper surface, a lower surface, a side surface, a cutting edge, and a mounting hole passing through the upper surface and the lower surface, wherein the upper surface is provided with a single upper surface boss unit surrounding the mounting hole and being planar, and the cutting edge includes a main cutting edge, a corner cutting edge connected to the main cutting edge, a secondary cutting edge connected to the corner cutting edge, and an edge portion connected to the secondary cutting edge. The first main cutting edge back face connected to the main cutting edge forms an acute angle with the extension line of the upper surface boss unit, and the secondary cutting edge chip breaking surface connected to the secondary cutting edge forms an angle with the extension line of the upper boss unit that increases away from the corner cutting edge. When the cutting insert is observed from the upper surface, the edge surface connected to the edge portion is concavely indented.

Description

Technical Field

[0001] The present invention relates to a cutting insert and a cutting tool equipped with the cutting insert. Background Art

[0002] Generally, a cutting insert is mounted to a cutting tool mounted on a machine tool and is used to cut a workpiece made of iron, nonferrous metal, nonmetallic material, etc., such as a machine part, etc. Such a cutting insert includes an upper surface, a lower surface oriented in opposite directions, a side surface joining the upper surface and the lower surface to each other, and a cutting edge forming a boundary between the upper surface and the side surface and configured to be basically used for cutting the workpiece.

[0003] Meanwhile, the main challenge associated with machining heat-resistant and tough workpieces such as stainless steel is poor chip rejection. In order to machine tough and weldable workpieces, it is necessary to improve the cutting quality of the tool and ensure large chip flutes.

[0004] Fig.12 and Fig.13 The cutting insert disclosed in JP2014-136264A is shown. For reference, Fig.12 and Fig.13 Corresponding to JP2014-136264A Fig. 9 and Fig.10 For ease of description, the reference numerals used in JP2014-136264A are used as is without modification, and even if these reference numerals overlap with reference numerals used in the following description of the embodiments of the present invention, these reference numerals do not necessarily refer to the same components.

[0005] The above-mentioned related cutting insert adopts a spiral bevel cutting edge structure to improve the cutting quality, but it requires that the upper mounting surface 13 is formed to be higher than the lowest part of the cutting edge, and the chip breaking surface of the secondary cutting edge 9 is formed to be a single angle. Therefore, although the related cutting insert can improve the cutting quality, there is a problem that it is not suitable for processing difficult-to-cut materials because the fluidity of the chips is not taken into consideration when forming the chip breaking surface and the cutting edge. Summary of the invention

[0006] Technical issues

[0007] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a cutting insert capable of ensuring good flow of chips by configuring the cutting insert so that chips are not blocked during the flow of chips, and a cutting tool mounted with the cutting insert.

[0008] Technical Solution

[0009] In order to achieve the above-mentioned purpose, the cutting blade according to an embodiment of the present invention is a double-sided cutting blade, which includes an upper surface, a lower surface, a side surface, a cutting edge and a mounting hole passing through the upper surface and the lower surface, wherein the upper surface can be provided with a single upper surface boss portion surrounding the mounting hole and being planar, the cutting edge can include a main cutting edge, a corner cutting edge extending from the main cutting edge, a secondary cutting edge extending from the corner cutting edge and a side portion extending from the secondary cutting edge, the back face of the first main cutting edge extending from the main cutting edge can form an acute angle with the extension line of the upper surface boss portion, the chip breaking surface of the secondary cutting edge extending from the secondary cutting edge can form a gradually increasing angle with the extension line of the upper surface boss portion as the chip breaking surface of the secondary cutting edge moves away from the corner cutting edge, and when the cutting blade is observed toward the upper surface, the side surface extending from the side portion can be concavely indented.

[0010] Furthermore, the main cutting edge chip breaking surface of the main cutting edge may form an angle that gradually decreases with the extension line of the upper surface boss portion as the main cutting edge chip breaking surface moves away from the corner cutting edge.

[0011] Furthermore, the minor cutting edge flank of the minor cutting edge may form a right angle with an extension line of the upper surface boss portion, and an angle formed by the corner cutting edge flank of the corner cutting edge and the extension line of the upper surface boss portion may vary along the corner cutting edge.

[0012] Furthermore, when the cutting insert is viewed toward the side surface, the main cutting edge may be inclined downward in a direction away from the corner cutting edge, and the upper surface boss portion may not be higher than a lowermost portion of the main cutting edge.

[0013] Furthermore, when viewing the cutting insert toward the side surface, the minor cutting edge may be inclined downward in a direction away from the corner cutting edge, and a side portion extending from the minor cutting edge may form a concave curve in the direction of the lower surface.

[0014] Furthermore, the cutting insert may be 180° rotationally symmetrical about a first center axis passing through the center of the mounting hole, and 180° rotationally symmetrical about a second center axis passing through the center of the side surface.

[0015] A cutting tool equipped with the above-mentioned cutting blade may include a main body having a flange portion and a front end portion, a plurality of blade mounting portions protruding radially from the main body, spaced apart from each other at predetermined intervals and having a seat portion for mounting the cutting blade, wherein when the cutting tool is observed from the side, the upper surfaces of the plurality of blade mounting portions may be formed concavely in the curved surface.

[0016] Beneficial effects

[0017] The cutting insert according to the embodiment of the present invention having the above-described configuration has the following effects.

[0018] The chip breaking surface of the secondary cutting edge forms an increasing angle with the upper surface boss portion as the secondary cutting edge chip breaking surface moves away from the corner cutting edge, and the surface of the side portion is concavely indented when viewed toward the upper surface, so that during workpiece processing, good chip discarding can be ensured by minimizing the blockage of chips generated from the workpiece in the direction of chip flow.

[0019] Furthermore, the main cutting edge chip breaking surface of the main cutting edge forms an angle that decreases with the extension line of the upper surface boss portion as the main cutting edge chip breaking surface moves away from the corner cutting edge, thereby ensuring the cutting edge rigidity of the main cutting edge during deep cutting processing.

[0020] Furthermore, when viewing the cutting insert sideways, the main cutting edge slopes downwardly away from the corner cutting edge, and the upper surface boss portion is no higher than the lowest portion of the main cutting edge, thereby minimizing collision of chips with the upper surface boss during cutting and improving chip fluidity.

[0021] In addition, when the cutting insert is viewed toward the side surface, the secondary cutting edge is inclined from the upper surface toward the lower surface in a direction away from the corner cutting edge, and the side portion extending from the secondary cutting edge forms a concave curve in the direction of the lower surface, thereby minimizing the chips being stuck on the side portion during cutting and improving the fluidity of the chips.

[0022] Meanwhile, it goes without saying that the present invention includes other effects which can be expected from the above-mentioned configuration although not explicitly described. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a perspective view of a cutting insert according to an exemplary embodiment of the present invention.

[0024] Figure 2 Viewed from the upper surface Figure 1 View of the cutting insert.

[0025] Figure 3 is Figure 2 Cross-sectional view in direction PP.

[0026] Figure 4 It is shown Figure 1 A partial enlarged view of the change in the clearance angle of the chip breaking surface of the secondary cutting edge of the cutting insert.

[0027] Figure 5 It is shown Figure 1 A partial enlarged view of the change in the clearance angle of the chip breaking surface of the main cutting edge of the cutting insert.

[0028] Figure 6 Shows Figure 1 The angle between the flank face of the main cutting edge and the flank face of the corner cutting edge of the cutting insert.

[0029] Figure 7 yes Figure 1 Side view of the cutting insert.

[0030] Figure 8 Is installed Figure 1 A stereoscopic view of a cutting tool with a cutting insert.

[0031] Fig. 9 The diagram shows the flange and the front end, respectively. Figure 8 cutting tools.

[0032] Fig.10 is shown to be coupled to each other Figure 1 Cutting blades and Figure 8 View of the cutting tool.

[0033] Fig.11 Shows Figure 1 Schematic diagram of the effect of the cutting blade.

[0034] Fig.12 and Fig.13 An example of a relevant cutting insert is shown. DETAILED DESCRIPTION

[0035] Hereinafter, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be apparent to those skilled in the art to which the present invention belongs. However, it should be understood that the present invention can be implemented in various other different forms and should not be construed as being limited to the specific examples described herein.

[0036] Meanwhile, in the present embodiment, a "double-sided cutting insert" refers to a cutting insert in which the upper surface can be used as a rake face when the lower surface is used as a mounting surface for a cutting tool, and conversely, when the upper and lower surfaces of the cutting insert are reversed so that the upper surface is used as a mounting surface for a cutting tool, the lower surface can be used as a rake face. Therefore, although an example in which the upper surface is used as a rake face and the lower surface located on the opposite side is used as a mounting surface for a cutting tool will be described below for ease of explanation, it should be understood that the same is also applicable when reversed.

[0037] like Figure 1 and Figure 2 As shown, a cutting insert according to one embodiment of the present invention (hereinafter referred to as “cutting insert”) is a double-sided cutting insert and includes an upper surface 1, a lower surface 2, a side surface 3, a cutting edge 4, and a mounting hole 5 passing through the upper surface 1 and the lower surface 2.

[0038] When viewed toward the upper surface (see Figure 2), for example, the cutting insert has a substantially rectangular shape, and has an effective corner edge 42 that participates in cutting during workpiece cutting and an ineffective corner edge 45 that does not participate in cutting at each of the four corners. Therefore, the cutting insert can use a total of 8 corners on both sides.

[0039] The upper surface 1 has a planar upper surface boss portion 11 surrounding the mounting hole 5. Figure 3 As shown, the upper surface boss portion 11 is parallel to an imaginary second central axis C2 passing through the center of the side surface 3 .

[0040] The cutting edge 4 includes a main cutting edge 41, a corner cutting edge 42 extending from the main cutting edge, and a minor cutting edge 43 extending from the corner cutting edge. In addition, a side portion 44 extending from the minor cutting edge 43 is provided.

[0041] like Figure 7 As shown, when the cutting insert is viewed toward the side surface, the main cutting edge 41 is inclined downward in a direction away from the corner cutting edge 42, and the upper surface boss portion 11 is not higher than the lowest part of the main cutting edge 41. Thus, the collision of chips with the upper surface boss portion 11 during cutting can be minimized, thereby improving the fluidity of the chips.

[0042] Furthermore, when the cutting insert is viewed toward the side surface (see Figure 7 ), the secondary cutting edge 43 is inclined downward from the upper surface to the lower surface in a direction away from the corner cutting edge 42 (i.e., in a direction approaching the unused corner cutting edge 45), and the side portion 44 extending from the secondary cutting edge 43 forms a concave curve in the direction of the lower surface 2. This also minimizes the chips from being stuck on the side portion 44 during cutting, thereby improving the fluidity of the chips.

[0043] At the same time, the side surface 3 includes a main cutting edge relief surface 31 extending from the main cutting edge 41, a corner cutting edge relief surface 32 extending from the corner cutting edge 42, and a secondary cutting edge relief surface 33 extending from the secondary cutting edge 43 (see FIG. Figure 1 ).

[0044] like Figure 3 As shown, the first main cutting edge flank 31 extending from the main cutting edge 41 is of a reverse positive angle type. That is, the angle α formed by the extension line of the upper surface boss portion (or the parallel line C2' of the second center axis C2) and the extension line of the first main cutting edge flank 31 is an acute angle. In this example, the angle α formed by the parallel line C2' of the second center axis C2 and the extension line of the first main cutting edge flank 31 refers to the internal angle in the direction of the first center axis C1. The same principle applies when defining the angles of other surfaces of the side surface 3 to be described below.

[0045] Thus, it is possible to ensure the rigidity of the main cutting edge 41. For reference, in the present embodiment, the main cutting edge flank 31 extending from the main cutting edge 41 is formed in three stages, specifically, including the first main cutting edge flank 31, the second main cutting edge flank 32, and the third main cutting edge flank 33 in the direction from the upper surface 1 to the lower surface 2. In this example, when the lower surface is used as the rake face, the third main cutting edge flank 33 is used as the main cutting edge flank face.

[0046] like Figure 4 As shown, the secondary cutting edge chip breaking surface 14 extending from the secondary cutting edge 43 forms an increasing angle (i.e., θ1<θ2<θ3) with the upper surface boss portion 11 as the secondary cutting edge chip breaking surface 14 moves away from the corner cutting edge 42 (i.e., as it approaches the unused corner cutting edge 45). In addition, when viewed from above, the side surface 15 of the side portion 44 extending from the secondary cutting edge 43 is concavely indented. Thus, good chip discarding during workpiece machining can be ensured by minimizing or preventing chips generated from the workpiece from being blocked in the direction of chip flow.

[0047] For reference, unlike the current implementation, Fig.11 (a) and Fig.11 (b) shows the simulation results ( Fig.11 (a) shows that when the angle of the secondary cutting edge chip breaking surface 14' extending from the secondary cutting edge 43' is kept constant and the side surface 15' extending from the side 44' is not concavely indented, the chips hit the side surface 15' when flowing, resulting in surface wear ( Fig.11 (b)), which produces the negative effect of chip twisting instead of smooth curling.

[0048] In contrast, Fig.11 (c) and Fig.11 The simulation result shown in (d) shows that in the present embodiment, the chips flow without hitting the surface of the side surface 15 and do not cause wear of the surface ( Fig.11 (d)), as a result, the chips curl smoothly without twisting and flow well ( Fig.11 (c)).

[0049] At the same time, if Figure 5 As shown, the main cutting edge chip breaking surface 11 of the main cutting edge 41 forms a decreasing angle (i.e., λ1>λ2>λ3) with the parallel line of the upper surface boss portion 11 as the main cutting edge chip breaking surface 11 moves away from the corner cutting edge 42. Thus, the rigidity of the cutting edge of the main cutting edge 41 during deep cutting processing can be ensured.

[0050] The angle β between the secondary cutting edge flank 32 of the secondary cutting edge 43 and the extension line of the upper surface boss portion 11 forms a right angle (so-called negative angle type). As a result, the rigidity of the cutting edge of the secondary cutting edge 43 can be ensured (see Figure 6 (b)).

[0051] The angle γ formed by the corner cutting edge flank 33 of the corner cutting edge 42 and the extension line of the upper surface boss portion 11 is not fixed but varies along the corner cutting edge 42, and the angle γ can have a value from a right angle (negative angle type) to an obtuse angle (so-called reverse positive angle type). As a result, the rigidity of the corner cutting edge 42 can be improved (see Figure 6 (c)).

[0052] At the same time, if Figure 1 As shown, the cutting insert may be 180° rotationally symmetrical about a first center axis C1 passing through the center of the mounting hole 5 , and may be 180° rotationally symmetrical about a second center axis C2 passing through the center of the side surface 3 .

[0053] As described above, since a cutting blade with good cutting quality is used for stainless steel processing, the possibility of damage to the cutting blade due to the work hardening layer increases, and the cutting blade according to the current embodiment can reduce the possibility of damage to the cutting blade by constructing the main cutting edge as a reverse positive angle type, constructing the secondary cutting edge as a negative angle type, and constructing the back face of the corner cutting edge as a variable back face with a non-fixed clearance angle.

[0054] Hereinafter, a cutting tool 200 on which the cutting insert according to the embodiment of the present invention described above is mounted will be described.

[0055] like Figure 8 and Fig. 9 As shown, the cutting tool 200 includes a main body 201 and a plurality of insert mounting portions 202 coupled to the main body 201 .

[0056] The main body 201 has a flange portion 2011 and a front end portion 2012 .

[0057] The plurality of insert mounting portions 202 radially protrude from the body 201 and are spaced apart from each other at predetermined intervals, and include a seat portion 2021 for mounting the cutting insert 100 .

[0058] In particular, when the cutting tool 200 is viewed toward the side, the upper surfaces 2022 of the plurality of insert mounting portions 202 are concavely formed in a curved shape (see FIG. Fig.10 ). As a result, the load on the cutting tool can be reduced, thereby reducing the load during machining, and also ensuring good chip fluidity.

[0059] Although the present invention has been described in conjunction with some examples herein, the present 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 concept of the present invention are also within the scope of the claims appended hereto.

[0060] Industrial Applicability

[0061] The present invention can be used for a cutting tool for cutting a workpiece.

Claims

1. A double-sided cutting insert, comprising an upper surface, a lower surface, a side surface, a cutting edge, and a mounting hole passing through the upper surface and the lower surface, wherein: The upper surface is provided with a single upper surface boss portion, which surrounds the mounting hole and is planar. The cutting edge includes a main cutting edge, a corner cutting edge extending from the main cutting edge, a minor cutting edge extending from the corner cutting edge, and a side portion extending from the minor cutting edge, A first main cutting edge flank extending from the main cutting edge forms an acute angle with an extension line of the upper surface boss portion. The secondary cutting edge chip breaking surface extending from the secondary cutting edge forms a gradually increasing angle with the extension line of the upper surface boss portion as the secondary cutting edge chip breaking surface moves away from the corner cutting edge, and When viewing the cutting insert toward the upper surface, a side surface extending from the side is concavely indented.

2. The cutting insert according to claim 1, wherein The main cutting edge chip breaking surface of the main cutting edge forms an angle with an extension line of the upper surface boss portion that gradually decreases as the main cutting edge chip breaking surface moves away from the corner cutting edge.

3. The cutting insert according to claim 1, wherein The secondary cutting edge flank surface of the secondary cutting edge forms a right angle with the extension line of the upper surface boss portion, and An angle formed by a corner cutting edge flank of the corner cutting edge and an extension line of the upper surface boss portion changes along the corner cutting edge.

4. The cutting insert according to claim 1, wherein When viewing the cutting insert toward the side surface: The main cutting edge is inclined downward in a direction away from the corner cutting edge, and The upper surface boss portion is not higher than the lowest portion of the main cutting edge.

5. The cutting insert according to claim 1, wherein When viewing the cutting insert toward the side surface: The minor cutting edge is inclined downward in a direction away from the corner cutting edge, and the side portion extending from the minor cutting edge forms a concave curve in a direction of the lower surface.

6. The cutting insert according to claim 1, wherein The cutting insert is rotationally symmetric by 180° about a first center axis passing through a center of the mounting hole, and is rotationally symmetric by 180° about a second center axis passing through a center of the side surface.

7. A cutting tool equipped with the cutting insert according to claim 1, comprising: a main body including a flange portion and a front end portion; A plurality of insert mounting portions radially protruding from the body, which are spaced apart from each other at predetermined intervals and have seats for mounting the cutting inserts, wherein: When the cutting tool is viewed toward the side, upper surfaces of the plurality of insert mounting portions are concavely formed in a curved surface.

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