Cutting insert and cutting tool assembly containing the same

Abstract

An embodiment of a cutting insert is provided. The cutting insert includes an upper surface, a lower surface, a plurality of side surfaces extending between the upper surface and the lower surface, an insert hole penetrating the upper surface and the lower surface, and a corner portion having a cutting edge. At least one of the upper surface and the lower surface includes a plurality of recesses extending between the insert hole and the corner portion. The plurality of recesses includes a first recess into which a portion of the mounting portion is inserted when the cutting insert is supported by the mounting portion, and a second recess into which another portion of the mounting portion is inserted when the cutting insert is supported by the mounting portion. The second recess has a sidewall spaced apart from the other portion of the mounting portion.

Description

Technical Field

[0001] The present disclosure relates to a cutting insert and a cutting tool assembly including the same.

Background Art

[0002] When cutting a workpiece using a cutting tool, in order to improve the surface roughness and quality of the machined surface, it is important to smoothly generate a chip in a shape where the chip is curled round, and to secure a space where the generated chip can be smoothly discharged. In particular, in the case of a turning insert, the cutting angle (the angle between the cutting edge of the insert and the surface of the workpiece) during back-turning is smaller than that during front-turning. Therefore, it is even more important to effectively arrange the cutting edge and the chip former with respect to the workpiece to secure a space where the chip can be smoothly discharged.

Summary of the Invention

Problems to be Solved by the Invention

[0003] In a conventional turning insert, in the case of a positive single-sided insert having a triangular shape and a holder to which such a positive single-sided insert is mounted, both sides of the insert are supported by the insert support portion of the holder located in the back-turning direction. With such a structure, it is difficult to secure a chip discharge space, and there is a problem that the cutting depth for back-turning is limited.

[0004] Furthermore, in conventional turning inserts, particularly negative double-sided inserts with a triangular shape, and holders on which such negative double-sided inserts are mounted, in addition to the problems caused by the structure of the insert support part of the holder mentioned above, the insert is mounted in the holder so that the upper surface of the insert is tilted at a negative angle with respect to the center line of the workpiece. Therefore, it becomes necessary to secure a relatively narrower chip discharge space compared to the case where a positive single-sided triangular insert is used, in which the arrangement of the upper surface of the cutting blade and chip former is at an angle that almost coincides with the center line of the workpiece. As a result, the condition of the generated chips is not good, and the flow of discharged chips is not smooth. [Means for solving the problem]

[0005] Various embodiments of this disclosure provide cutting inserts that can smoothly generate chips during turning and satisfactorily discharge the chips, and cutting tool assemblies including the same.

[0006] Furthermore, various embodiments of this disclosure provide cutting inserts having a robust structure even without an insert support portion of the holder, and cutting tool assemblies including the same.

[0007] According to one embodiment of the present disclosure, a cutting insert is provided which is supported by a mounting portion when mounted on a cutting tool. The cutting insert includes a top surface, a bottom surface, a plurality of sides extending between the top surface and the bottom surface, an insert hole penetrating the top surface and the bottom surface, and a corner portion having a cutting edge, wherein at least one of the top surface and the bottom surface has a plurality of recesses extending between the insert hole and the corner portion, the plurality of recesses including a first recess into which a portion of the mounting portion is inserted when the cutting insert is supported by the mounting portion, and a second recess into which the other portion of the mounting portion is inserted when the cutting insert is supported by the mounting portion, the second recess having a side wall separated from the other portion of the mounting portion.

[0008] In one embodiment, the first recess may be in contact with the mounting portion at two points, and the second recess may have a bottom surface that is in contact with the mounting portion.

[0009] In one embodiment, the first recess and the mounting portion may be in contact with each other at a pair of first contact points, the bottom surface of the second recess and the mounting portion may be in contact with each other at a second contact point, and the line connecting one of the first contact points and the second contact point may have an inclination angle with respect to a reference plane that is perpendicular to the extension direction of the insert hole.

[0010] In one embodiment, the upper and lower surfaces may each include a rake face inclined with respect to a reference plane perpendicular to the extension direction of the insert hole, the upper and lower surfaces may be symmetrical with respect to each other, and the upper and lower surfaces may each include three corner portions.

[0011] In one embodiment, the inclination angle is greater than 0° and less than or equal to 9°, and preferably 4° to 6°.

[0012] In one embodiment, two corner portions are provided on the upper surface, and the two corner portions may be 180° rotationally symmetric with respect to the central axis of the insert hole.

[0013] In one embodiment, the inclination angle is greater than 0° and less than or equal to 9°, and preferably 1° to 2°.

[0014] According to another embodiment, a cutting tool assembly is provided, comprising a holder configured such that a cutting insert is supported by a mounting portion. The mounting portion includes a first protrusion and a second protrusion formed on a surface supporting the cutting insert, the holder is configured to support the cutting insert by contacting the side surface of the cutting insert and to fix the cutting insert to the mounting portion through fixing means, the cutting insert includes a top surface, a bottom surface, a plurality of sides extending between the top surface and the bottom surface, an insert hole penetrating the top surface and the bottom surface, and a corner portion having a cutting edge, at least one of the top surface and the bottom surface having a plurality of recesses extending between the insert hole and the corner portion, the plurality of recesses including a first recess into which the first protrusion of the mounting portion is inserted when the cutting insert is supported by the mounting portion, and a second recess into which the second protrusion of the mounting portion is inserted when the cutting insert is supported by the mounting portion, the second recess having a side wall spaced apart from the second protrusion of the mounting portion.

[0015] In other embodiments, the first recess is at two points Sim The first protrusion may come into contact with the second recess, and the second recess may have a bottom surface that comes into contact with the second protrusion of the mounting portion.

[0016] In other embodiments, the first recess and the first protrusion of the mounting portion may be in contact with each other at a pair of first contact points, the bottom surface of the second recess and the second protrusion of the mounting portion may be in contact with each other at a second contact point, and the line connecting one of the first contact points and the second contact point may have an inclination angle with respect to a reference plane that is perpendicular to the extension direction of the insert hole.

[0017] In other embodiments, the upper and lower surfaces of the cutting insert may each include a rake face inclined with respect to a reference plane perpendicular to the extension direction of the insert hole, the upper and lower surfaces may be symmetrical with respect to each other, and the upper and lower surfaces may each include three corners.

[0018] In other embodiments, the inclination angle is greater than 0° and less than or equal to 9°, and preferably 4° to 6°.

[0019] In other embodiments, when the cutting insert is mounted on the holder, the upper surface of the cutting insert may form an angle of -5° to +5° with respect to the center line of the workpiece to be cut by the cutting insert.

[0020] In other embodiments, two corner portions may be provided on the upper surface, and the two corner portions may be rotationally symmetric about the central axis of the insert hole by 180°.

[0021] In other embodiments, the inclination angle may be greater than 0° and less than or equal to 9°, preferably 1° to 2°.

[0022] In other embodiments, when the cutting insert is mounted on the holder, only the side surface of the cutting insert located on the opposite side of the first recess may contact the holder.

[0023] In other embodiments, the cutting edge located on one side of the first recess of the cutting insert may form an angle less than 90° with respect to the rotational center axis of the workpiece, and the cutting edge located on the other side of the first recess of the cutting insert may form an angle greater than 90° with respect to the rotational center axis of the workpiece.

Advantages of the Invention

[0024] According to the embodiments of the present disclosure, the cutting insert can induce the generation of soft chips and good chip evacuation through the effective arrangement of the cutting edges and the height of the chip former. Therefore, by machining the workpiece in the direction of back-turning with a small cutting angle, smooth chip evacuation can be induced.

Brief Description of the Drawings

[0025] The accompanying drawings, which are included in and constitute a part of this specification, illustrate embodiments of the present disclosure.

[0026] [Figure 1] It is a perspective view showing a cutting tool assembly according to an embodiment of the present disclosure.

[0027] [Figure 2] Figure 1 is an exploded perspective view of the cutting tool assembly shown.

[0028] [Figure 3] A perspective view showing a cutting insert according to one embodiment of the present disclosure.

[0029] [Figure 4] Figure 3 is a plan view of the cutting insert shown.

[0030] [Figure 5] Figure 3 is a side view of the cutting insert shown.

[0031] [Figure 6] This is a perspective view showing a shim for supporting a cutting insert according to one embodiment of the present disclosure.

[0032] [Figure 7] This is a schematic perspective view showing the contact area between the cutting insert shown in Figure 3 and the shim shown in Figure 6.

[0033] [Figure 8] This diagram illustrates the contact area between the cutting insert shown in Figure 3 and the shim shown in Figure 6.

[0034] [Figure 9] This is a cross-sectional view taken along line A-A in Figure 8.

[0035] [Figure 10] Figure 8 is a side view of the cutting insert and shim shown.

[0036] [Figure 11] Figure 1 is a diagram showing the cutting tool assembly in the process of cutting a workpiece.

[0037] [Figure 12] A perspective view showing a cutting tool assembly according to another embodiment of the present disclosure.

[0038] [Figure 13] Figure 12 is an exploded perspective view of the cutting tool assembly shown.

[0039] [Figure 14] A perspective view showing a cutting insert according to another embodiment of the present disclosure.

[0040] [Figure 15] Figure 14 is a plan view of the cutting insert shown.

[0041] [Figure 16] Figure 14 is a perspective view of the cutting insert shown from another direction.

[0042] [Figure 17] Figure 14 is a bottom view of the cutting insert shown.

[0043] [Figure 18] Figure 14 is a side view of the cutting insert shown.

[0044] [Figure 19] A perspective view showing a shim for supporting a cutting insert according to another embodiment of the present disclosure.

[0045] [Figure 20] This is a schematic perspective view showing the contact area between the cutting insert shown in Figure 14 and the shim shown in Figure 19.

[0046] [Figure 21] This diagram illustrates the contact area between the cutting insert shown in Figure 14 and the shim shown in Figure 19.

[0047] [Figure 22] This is a cross-sectional view taken along the line B-B in Figure 21.

[0048] [Figure 23] Figure 21 is a side view of the cutting insert and shim shown.

[0049] [Figure 24] Figure 1 is a diagram illustrating the shape of the holder of the cutting tool assembly shown, and the angle that the cutting blade makes with the rotational axis of the workpiece.

[0050] [Figure 25] Figure 12 is a diagram illustrating the shape of the holder of the cutting tool assembly shown, and the angle that the cutting blade makes with the rotational axis of the workpiece. [Modes for carrying out the invention]

[0051] The embodiments described herein are illustrative for the purpose of illustrating the technical concept of this disclosure. The scope of rights under this disclosure is not limited to the embodiments presented below or the specific descriptions relating thereto.

[0052] All technical and scientific terms used in this disclosure, unless otherwise defined, have meanings that would be generally understood by a person with ordinary skill in the art to which this disclosure pertains. All terms used in this disclosure have been chosen for the purpose of further clarifying this disclosure and not to limit the scope of rights granted by this disclosure.

[0053] Expressions such as “includes,” “equipment,” and “possess” as used in this disclosure should be understood as open-ended terms that may include other embodiments, unless otherwise specifically mentioned in the phrase or sentence containing such expression.

[0054] Unless otherwise specified, singular expressions described in this disclosure may have plural meanings, and this also applies to singular expressions described in the claims.

[0055] The terms "First," "Second," etc., used in this disclosure are used to distinguish between multiple components and do not limit the order or importance of those components.

[0056] Directional indicators such as "up" and "top" used in this disclosure are based on the direction in which the top surface is located relative to the bottom surface in the attached drawings. Directional indicators such as "down" and "bottom" mean the opposite direction to "up" or "top". The cutting inserts shown in the attached drawings may be oriented differently, and these directional indicators may be interpreted accordingly.

[0057] The following describes embodiments of cutting inserts and cutting tool assemblies containing them with reference to the attached drawings. In the attached drawings, identical or corresponding components are given the same reference numerals. In the following description of embodiments, redundant descriptions of identical or corresponding components may be omitted. However, the omission of technical details regarding a component does not mean that such a component is not included in the embodiment.

[0058] The following describes embodiments of cutting inserts and cutting tool assemblies including them, with reference to the attached drawings.

[0059] Figure 1 is a perspective view showing a cutting tool assembly 1 according to one embodiment of the present disclosure. Figure 2 is an exploded perspective view of the cutting tool assembly 1 shown in Figure 1.

[0060] Referring to Figures 1 and 2, the cutting tool assembly 1 may be used for turning. The cutting tool assembly 1 may be configured to cut a rotating workpiece W mounted on a lathe (see Figure 11). The cutting tool assembly 1 may include a cutting insert 100, a mounting portion 200 or 305, and a holder 300. The mounting portion 200 or 305 is Sim It could be 200, or, Sim If not available, the bottom surface 305 of the holder pocket portion may be used. In the following, the mounting portion 200 or 305 is Sim Let's explain the case where the value is 200.

[0061] The holder 300 is a cutting insert 100 and Sim It is used to fix the value at 200. Sim When attaching 200 to holder 300, Sim A projection corresponding to a groove formed on the lower surface 220 of 200 may be formed on the bottom surface 305 of the pocket portion of the holder 300. Sim The 200 grooves and the projections of the holder 300 can come into contact with each other. Sim When 200 is viewed from below, for example, a groove having a triangular or other shape Sim The projection is formed on the lower surface 220 of 200. The projection is formed to have a cross-section corresponding to a groove formed on the lower surface 220 of shim 200, for example, a triangle or other shape. The projection has a recessed corner.

[0062] When attaching the cutting insert 100 to the holder 300, Sim 200 can be mounted on holder 300, and cutting insert 100 Sim It can be mounted on the upper surface 210 of 200. The side of the pocket portion of the holder 300 can contact the side 130 of the cutting insert 100 and support the side 130 of the cutting insert 100, and the cutting insert 100 and the fixing means 301 Sim It can be fixed at 200. Specifically, Sim The 200 can be fixed to the holder 300 by fastening means such as a screw. Sim The cutting insert 100 mounted on the upper surface 210 of 200 can be fixed by a clamp 302 or by a fixing means 301 such as a screw. The clamp 302 can be fixed to the holder 300 by a clamp screw 303.

[0063] In one embodiment of the cutting tool assembly 1, Sim A groove formed on the lower surface 220 of 200 is connected to a projection formed on the holder 300. Sim 200 is fixed to the holder 300 by a fixing means such as a screw. The cutting insert 100 is SimIt is located on the upper surface 210 of 200. The clamp 302 contacts the insert hole 140 of the cutting insert 100. The clamp 302 is secured to the holder 300 by the clamp screw 303. The clamp 302 can push the cutting insert 100 toward the shim 200 and can also push the cutting insert 100 toward the holder 300. The cutting insert 100 is Sim The components 200, holder 300, and clamp 302 are fixed in contact with each other to form the cutting tool assembly 1.

[0064] Figure 3 is a perspective view showing a cutting insert 100 according to one embodiment of the present disclosure. Figure 4 is a plan view of the cutting insert 100 shown in Figure 3. Figure 5 is a side view of the cutting insert 100 shown in Figure 3.

[0065] Referring to Figures 3 to 5, the cutting insert 100 includes an upper surface 110, a lower surface 120, three side surfaces 130 extending between the upper surface 110 and the lower surface 120, and an insert hole 140 penetrating the upper surface 110 and the lower surface 120. The cutting insert 100 may, for example, have a triangular shape and may be symmetrical with respect to the insert hole 140 penetrating the upper surface 110 and the lower surface 120. The upper surface 110 and the lower surface 120 of the cutting insert 100 may be flat overall or partially, and may include curved surfaces formed on at least a portion of the upper surface 110 and the lower surface 120. Also, portions of the upper surface 110 and the lower surface 120 may be formed at an angle to the other portions. A corner portion 150 is formed on the cutting insert 100, and cutting blades 151 and 152 are formed on each of the corner portions 150. The cutting blades 151 and 152 are used to cut the workpiece (W). Rake faces may be formed such that the thickness of the cutting insert 100 decreases from the corner portion 150 of the cutting insert 100 toward the insert hole 140. When the cutting insert 100 is fixed to the holder 300, clamp contact surfaces 141 and 142 that the clamp 302 contacts may be formed in the insert hole 140. At the clamp contact surface 141, the clamp 302 holds the cutting insert 100. SimA pushing force can be applied toward 200. At the clamp contact surface 142, the clamp 302 can apply a pushing force to the cutting insert 100 toward the holder 300. The cutting insert 100 may have a total of six corner portions 150, including three corner portions 150 on the upper surface 110 and three corner portions 150 on the lower surface 120. Cutting blades 151 and 152 may be formed in each of the corner portions 150. Recesses are formed on the upper surface 110 and the lower surface 120. The recesses include a first recess 160 located on the side farther from the insert hole 140, and a second recess 170 located on the side closer to the insert hole 140. The bottom surface 171 and side walls 172 may be formed in the second recess 170. On the upper surface 110 and the lower surface 120 of the cutting insert 100, each corner portion 150 and recess may be formed symmetrically with respect to the insert hole 140. The upper surface 110 and lower surface 120 of the cutting insert 100 may also be formed symmetrically with respect to each other. Sim When supported by 200, the first recess 160 and the second recess 170 correspond to Sim The first protrusion 260 and the second protrusion 270 of 200 can be accommodated. The side wall 172 of the second recess 170 corresponds to Sim The second protrusion 270 of 200 does not come into contact with the side wall 272. In the above embodiment, the mounting portion 200 or 305 Sim The case where it is 200 was explained. However, when the mounting portion 200 or 305 is the bottom surface 305 of the holder pocket portion, the first protrusion 260 and the second protrusion 270 are formed on the bottom surface 305 of the holder pocket portion.

[0066] Figure 6 shows a support for a cutting insert 100 according to one embodiment of the present disclosure. Sim This is a perspective view showing 200.

[0067] Referring to Figure 6, a shim 200 for supporting a cutting insert 100 according to one embodiment will be described.

[0068] Sim 200 may have, for example, a triangular shape or other shapes. Sim200 has an upper surface 210, a lower surface 220, three side surfaces 230 extending between the upper surface 210 and the lower surface (220), and penetrates the upper surface 210 and the lower surface 220. Sim It includes a hole 240. Three sides 230 extend between the top surface 210 and the bottom surface 220. Sim When 200 is fixed to holder 300, fixing means such as screws Sim The first protrusion 260 and the second protrusion 270 of the cutting insert 100 correspond to the first recess 160 and the second recess 170. Sim The upper surface 210 of 200, i.e., supporting the cutting insert 100. Sim It is formed on the surface of 200. The protrusions are, Sim Centered around Hall 240 Sim The first protrusion 260 located on the side furthest from the hole 240, and Sim It includes a second protrusion 270 located on the side closer to the hole 240. The second protrusion 270 is formed to have an upper surface 271 and a side wall 272. The cutting insert 100 is Sim When supported by 200, the first protrusion 260 and the second protrusion 270 are inserted into the corresponding first recess 160 and second recess 170 of the cutting insert 100 to support the cutting insert 100. Only the upper surface 271 of the second protrusion 270 contacts the bottom surface 171 of the second recess 170. The side wall 272 of the second protrusion 270 does not contact the side wall 172 of the second recess 170. Sim When 200 is attached to holder 300, Sim A groove for fixing 200 Sim It may be formed on the lower surface 220 of 200.

[0069] Figure 7 shows the cutting insert 100 shown in Figure 3 and the cutting insert shown in Figure 6. Sim Figure 8 is a schematic perspective view showing the contact area between 200 and the cutting insert 100 shown in Figure 3 and Figure 6. Sim This is a diagram illustrating the contact portion of 200. Figure 9 is a cross-sectional view taken along line A-A in Figure 8. Figure 10 shows the cutting insert 100 shown in Figure 8 and Sim This is a side view of the 200.

[0070] Referring to Figures 7 to 10, a cutting insert 100 according to one embodiment and Sim Let's explain the 200 contact points.

[0071] Cutting insert 100 Sim When supported by 200, the first recess 160 of the cutting insert 100 is at a pair of first contact points 181 Sim The first protrusion 260 of 200 makes contact. The bottom surfaces 171 of the two second recesses 170 of the cutting insert 100 are at the second contact point 182. Sim The two second protrusions 270 of 200 contact the upper surfaces 271 of each. Sim Since the 200s contact each other at a pair of first contact points 181, the cutting insert 100 is firmly supported not only vertically but also laterally. Therefore, the lateral movement and vibration of the cutting insert 100 during cutting operations can be minimized. Sim The upper surface 271 of the second protrusion 270 of 200 is formed as a rounded curved surface so as to make point contact rather than surface contact with the bottom surface 171 of the second recess 170 of the cutting insert 100. Sim When supported by 200, at the second contact point 182, Sim 200 does not make contact laterally, only at the first contact point 181. Sim While in contact with 200 in a lateral direction, the cutting insert 100 simply Sim It is placed on 200. The cutting insert 100 is at the second contact point 182. Sim Without contact with 200 in the lateral direction Sim Since it is simply placed on top of 200, the cutting insert 100 can be stably supported at the first contact point 181 without interfering with lateral support.

[0072] Furthermore, the cutting insert 100 is formed in general by a primary pressing process and a secondary grinding process. The second recess 170 is completed by the primary pressing process and does not undergo a grinding process. Sim For stable support at 200, the relative height difference between the first recess 160 and the second recess 170 and the corresponding SimThe relative height difference between the first protrusion 260 and the second protrusion 270 of 200 is important. Since the grinding process is more difficult to control precisely than the pressing process, if the second recess 170 is completed solely by the pressing process, it becomes easier to control the relative height difference mentioned above, as well as to manufacture and manage the cutting tool assembly.

[0073] Cutting insert 100 Sim When supported by 200, the first contact point 181 is located lower than the second contact point 182 with respect to a reference plane RP that is perpendicular to the extension direction of the insert hole 140. In other words, the line connecting one of the first contact points 181 and the second contact point 182, which is located on the same side of the insert hole 140 as the first contact point 181, has an inclination angle p with respect to the reference plane RP that is perpendicular to the extension direction of the insert hole 140. Due to the inclination angle p, the cutting insert 100 is more stable at the first contact point 181 compared to when there is no inclination angle (p = 0°) or when the inclination angle is opposite (p < 0°). Sim It can be mounted in contact with 200. Stable contact at the first contact point 181 is very important in that it prevents lateral movement or minute vibrations of the cutting insert 100 when performing cutting operations. At the second contact point 182, the side wall 172 of the second recess 170 and the side wall 272 of the second protrusion 270 do not come into contact, and the cutting insert 100 is simply Sim It is placed on top of 200. As a result, the cutting insert 100 can be stably supported without interfering with its function of preventing minute vibrations at the first contact point 181.

[0074] Cutting insert 100 according to one embodiment and Sim In 200, the inclination angle p is greater than 0° and less than or equal to 9°, and is preferably 4° to 6°. If the inclination angle p is less than 4°, the active corner portion (the corner portion on the first recess side) of the cutting insert 100 may lift slightly upward, which can make it difficult to select the initial position before fixing it with the fixing means 301. If the inclination angle p is greater than 6°, the active corner portion of the cutting insert 100 may slide slightly downward, which can make it difficult to select the initial position before fixing it with the fixing means 301.

[0075] Figure 11 is a diagram showing the state in which the cutting tool assembly 1 from Figure 1 is cutting the workpiece W.

[0076] Referring to Figure 11, the cutting of a workpiece W by a cutting tool assembly 1 according to one embodiment will be described.

[0077] When the cutting insert 100 according to one embodiment is mounted on the holder 300, the angle e that the upper surface 110 of the cutting insert 100 makes with respect to the center line of the workpiece W to be cut by the cutting insert 100 is -5° to +5°. Therefore, a smooth chip discharge space can be ensured when performing the cutting operation. This improves the condition of the chip and the flow of the chip.

[0078] Figure 12 is a perspective view showing a cutting tool assembly 5 according to another embodiment of the present disclosure. Figure 13 is an exploded perspective view of the cutting tool assembly 5 shown in Figure 12.

[0079] Referring to Figures 12-13, a cutting tool assembly 5 according to another embodiment will be described. The cutting tool assembly 5 may include a cutting insert 500, a mounting portion 600 or 705, and a holder 700. The mounting portion 600 or 705 is Sim 600 or Sim If not, it may be the bottom surface 705 of the holder pocket. In the following, the mounting portion 600 or 705 is Sim Let's explain the case where this is the case.

[0080] Mounting part 600 or 705 Sim In the case of 600, Sim A groove formed on the lower surface 620 of 600 connects with a projection formed on the bottom surface 705 of the holder pocket. Sim 600 is fixed to holder 700 by fixing means such as screws. Cutting insert 500 Sim Located on the upper surface 610 of 600, a screw or the like contacts the insert hole 540 of the cutting insert 500, and the cutting insert 500 SimIt is fixed to 600 and holder 700. The cutting insert 500 is Sim The 600, holder 700, and fixing means 701 are fixed in contact with each other to form the cutting tool assembly 5.

[0081] Figure 14 is a perspective view showing a cutting insert 500 according to another embodiment of the present disclosure. Figure 15 is a plan view of the cutting insert 500 shown in Figure 14. Figure 16 is a perspective view of the cutting insert 500 shown in Figure 14 from another direction. Figure 17 is a bottom view of the cutting insert 500 shown in Figure 14. Figure 18 is a side view of the cutting insert 500 shown in Figure 14.

[0082] Refer to Figures 14-18 to describe cutting inserts 500 according to other embodiments.

[0083] The cutting insert 500 includes an upper surface 510, a lower surface 520, four side surfaces 530 extending between the upper surface 510 and the lower surface 520, and an insert hole 540 penetrating the upper surface (510) and the lower surface (520). The cutting insert 500 may have two corner portions 550 on its upper surface 510. Cutting blades 551 and 552 may be formed on each corner portion 550. The two corner portions 550 are 180° rotationally symmetric with respect to the central axis of the insert hole 540. A recess is formed on the lower surface 520. The recess includes a first recess 560 extending from the insert hole 540 toward the corner portion 550 and a second recess 570 formed around the first recess 560. A bottom surface 571 and side walls 572 may be formed in the second recess 570. The lower surface 520 of the cutting insert 500 is also 180° rotationally symmetric with respect to the central axis of the insert hole 540. Sim When supported by 600, the first recess 560 and the second recess 570 correspond to Sim The first protrusion 660 and the second protrusion 670 of 600 are accommodated, and the second recess 570 has a side wall 572 Sim The second protrusion 670 corresponding to 600 does not come into contact with the side wall 672 of 600. In the above embodiment, the mounting portion 600 or 705 SimThe case where it is 600 was explained. However, if the mounting portion 600 or 705 is the bottom surface 705 of the holder pocket portion, the first protrusion 660 and the second protrusion 670 are formed on the bottom surface 705 of the holder pocket portion.

[0084] Figure 19 shows a support for a cutting insert 500 according to another embodiment of the present disclosure. Sim This is a perspective view showing 600.

[0085] Refer to Figure 19 for supporting the cutting insert 500 according to another embodiment. Sim Let me explain 600.

[0086] Sim 600 has an upper surface 610, a lower surface 620, a side surface 630 extending between the upper surface 610 and the lower surface (620), and penetrates the upper surface 610 and the lower surface 620. Sim Includes Hall 640. Sim When 600 is fixed to holder 700, fixing means such as screws Sim It penetrates the hole 640. The first protrusion 660 and the second protrusion 670 correspond to the first recess 560 and the second recess 570 of the cutting insert 500. Sim The upper surface 610 of 600, that is, the surface that supports the cutting insert 500, is formed. The protrusion is Simhole Centered around 640 Sim The first protrusion 660 located on the side furthest from the hole 640, and Sim It includes a second protrusion 670 located on the side closer to the hole 640. The second protrusion 670 is formed to have an upper surface 671 and a side wall 672. The cutting insert 500 Sim When supported by 600, the first protrusion 660 and the second protrusion 670 are inserted into the first recess 560 and the second recess 570 of the corresponding cutting insert 500. Only the upper surface 671 of the second protrusion 670 contacts the bottom surface 571 of the second recess 570. The side walls 672 of the second protrusion 670 do not contact the side walls 572 of the second recess 570.

[0087] Figure 20 shows the cutting insert 500 shown in Figure 14 and Figure 19 SimFigure 21 is a schematic perspective view showing the contact area between 600 and the cutting insert 500 shown in Figure 14 and Figure 19. Sim This is a diagram illustrating the contact area between 600 and 600. Figure 22 is a cross-sectional view taken along the line B-B in Figure 21. Figure 23 shows the cutting insert 500 shown in Figure 21 and Sim This is a side view of the 600.

[0088] Refer to Figures 20 to 23 for cutting insert 500 in other embodiments and Sim Let's explain the contact points of the 600.

[0089] Cutting insert 500 Sim When supported by 600, the first recess 560 of the cutting insert 500 is at two first contact points 581 Sim The first protrusion 660 of 600 makes contact. The bottom surfaces 571 of the two second recesses 570 of the cutting insert 500 are at the second contact point 582. Sim The two second protrusions of 600 contact the upper surface 671 of 670, respectively. Cutting insert 500 and Sim Since the 600 contacts each other at two first contact points 581, the cutting insert 500 is firmly supported not only vertically but also laterally. Therefore, when performing cutting operations, the lateral movement and vibration of the cutting insert 500 can be minimized. Sim The upper surface 671 of the second protrusion 670 of 600 is formed as a rounded curved surface so as to make point contact rather than surface contact with the bottom surface 571 of the second recess 570 of the cutting insert 500. Sim When supported by 600, at the second contact point 582, Sim Without making lateral contact with 600, the cutting insert 500 makes lateral contact only at the first contact point 581, and simply Sim It is placed on top of 600. The cutting insert 500 does not make lateral contact at the second contact point 582. Sim Since it is simply placed on top of 600, the cutting insert 500 can be stably supported at the first contact point 581 without interfering with lateral support.

[0090] Furthermore, the cutting insert 500 is formed in general by a primary pressing process and a secondary grinding process. The second recess 570 is completed by the primary pressing process, and no further grinding is performed thereafter. Sim For stable support at 600, the relative height difference between the first recess 560 and the second recess 570 and the corresponding Sim The relative height difference between the first protrusion 660 and the second protrusion 670 of 600 is important. Since the grinding process is more difficult to control precisely than the pressing process, if the second recess 570 is completed solely by the pressing process, it becomes easier to control the relative height difference mentioned above, as well as to manufacture and manage the cutting tool assembly.

[0091] Cutting insert 500 Sim When supported by 600, the first contact point 581 is located lower than the second contact point 582 with respect to a reference plane RP that is perpendicular to the extension direction of the insert hole 540. That is, the line connecting one of the first contact points 581 and the second contact point 582, which is located on the same side of the insert hole 540 as the first contact point 581, has an inclination angle q with respect to the reference plane RP that is perpendicular to the extension direction of the insert hole 540. Due to the inclination angle q, the cutting insert 500 is more stable at the first contact point 581 compared to when there is no inclination angle (q = 0°) or when the inclination angle is opposite (q < 0°). Sim It can be mounted in contact with 600. Stable contact at the first contact point 581 is very important in that it functions to prevent lateral movement or micro-vibrations of the cutting insert 500 when performing cutting operations. At the second contact point 582, the side wall 572 of the second recess 570 and the side wall 672 of the second protrusion 670 do not come into contact, and the cutting insert 500 simply Sim It is placed on top of 600. As a result, the cutting insert 500 can be stably supported without interfering with its function of preventing minute vibrations at the first contact point 581.

[0092] Cutting insert 500 according to one embodiment and SimIn 600, the inclination angle q is greater than 0° and less than or equal to 9°, and is preferably 1° to 2°. If the inclination angle q is less than 1°, the active corner portion of the cutting insert 500 (the corner portion on the first recess side) may lift slightly upward, which can make it difficult to select the initial position before fixing it with the fixing means 701. If the inclination angle q is greater than 2°, the active corner portion of the cutting insert 500 may slide slightly downward, which can make it difficult to select the initial position before fixing it with the fixing means 701.

[0093] Figure 24 is a diagram illustrating the shape of the holder 300 of the cutting tool assembly 1 shown in Figure 1 and the angles a and b that the cutting blades 151 and 152 make with respect to the rotational axis of the workpiece W. Figure 25 is a diagram illustrating the shape of the holder 700 of the cutting tool assembly 5 shown in Figure 12 and the angles a and b that the cutting blades 551 and 552 make with respect to the rotational axis of the workpiece W.

[0094] Referring to Figures 24 and 25, the features of the holders 300 and 700 of the cutting tool assemblies 1 and 5 shown in Figures 1 and 12, and the angles a and b that the cutting blades 151, 152, 551, and 552 make with respect to the rotational axis of the workpiece W will be explained.

[0095] In the cutting tool assemblies 1 and 5 shown in Figures 1 and 12, the first recesses 160 and 560 support the cutting insert laterally. Therefore, the insert support portion of the holders 300 and 700 in the back-turning direction can be eliminated. This allows the cutting tool assemblies 1 and 5 to be used at an appropriate cutting depth and provides space for smooth chip ejection. By minimizing the lateral movement and vibration of the cutting insert, insert breakage can be prevented and accuracy can be improved. Furthermore, the angle b that the cutting blades 152 or 552 in the back-turning direction of the first recess 160 or 560 of the cutting insert 100 or 500 make with respect to the rotational axis of the workpiece W, i.e., the cutting angle b during back-turning, is less than 90°, while the angle a that the cutting blades 151 or 551 in the front-turning direction of the first recess 160 or 560 of the cutting insert 100 or 500 make with respect to the rotational axis of the workpiece W, i.e., the cutting angle a during front-turning, is greater than 90°. Since the cutting angle b during back-turning is smaller than the cutting angle a during front-turning, it is all the more important to ensure chip evacuation space through the effective arrangement of the cutting blades 151, 152, 551, and 552 and the height of the chip former. The cutting inserts 100, 500 according to one embodiment and other embodiments of this disclosure can induce the generation of soft chips and good chip evacuation through the effective arrangement of the cutting edges 151, 152, 551, 552 and the height of the chip former. Therefore, smooth chip evacuation can be induced by machining the workpiece in a back-turning direction with a small cutting angle.

[0096] While specific embodiments have been described, these embodiments are presented for illustrative purposes only and are not intended to limit the scope of this disclosure. In fact, the embodiments described herein can be carried out in a variety of other forms. Furthermore, various omissions, substitutions, and modifications can be made in the forms of the embodiments described herein, without departing from the scope of this disclosure. The attached claims and their equivalents are within the scope of this disclosure and are intended to include such forms or variations.

Claims

1. A cutting insert that is supported by the mounting portion when attached to a cutting tool. Top surface and, The bottom and, Multiple side surfaces extending between the upper surface and the lower surface, An insert hole that penetrates the upper surface and the lower surface, and Corner section equipped with cutting blades Includes, At least one of the upper surface and the lower surface has a plurality of recesses extending between the insert hole and the corner portion, The plurality of recesses include a first recess into which a portion of the mounting portion is inserted when the cutting insert is supported by the mounting portion, and a second recess into which the other portion of the mounting portion is inserted when the cutting insert is supported by the mounting portion. The first recess contacts the mounting portion at two points, The second recess has a side wall separated from the other part of the mounting portion and a bottom surface that contacts the mounting portion. Cutting insert.

2. The first recess and the mounting portion are in contact with each other at a pair of first contact points. The bottom surface of the second recess and the mounting portion are in contact with each other at the second contact point. The line connecting one of the first contact points and the second contact point forms an inclination angle with respect to a reference plane that is perpendicular to the extension direction of the insert hole. The cutting insert according to claim 1.

3. Each of the above upper surface and the above lower surface includes an inclined surface that is inclined with respect to the reference plane which is perpendicular to the extension direction of the insert hole, The upper surface and the lower surface are symmetrical to each other. Each of the aforementioned upper and lower surfaces includes three corner portions. The cutting insert according to claim 2.

4. The aforementioned inclination angle is greater than 0° and less than or equal to 9°. The cutting insert according to claim 3.

5. The aforementioned inclination angle is between 4° and 6°. The cutting insert according to claim 3.

6. Two corner sections are provided on the upper surface, The two corner portions are 180° rotationally symmetric with respect to the central axis of the insert hole. The cutting insert according to claim 2.

7. The aforementioned inclination angle is greater than 0° and less than or equal to 9°. The cutting insert according to claim 6.

8. The aforementioned inclination angle is 1° to 2°. The cutting insert according to claim 6.

9. A cutting tool assembly including a holder configured such that a cutting insert is supported by a mounting portion, The mounting portion includes a first protrusion and a second protrusion formed on the surface that supports the cutting insert. The holder is configured to contact the side surface of the cutting insert to support the cutting insert and to fix the cutting insert to the mounting portion through a fixing means. The cutting insert includes an upper surface, a lower surface, a plurality of side surfaces extending between the upper surface and the lower surface, an insert hole penetrating the upper surface and the lower surface, and a corner portion equipped with a cutting blade. At least one of the upper surface and the lower surface is provided with a plurality of recesses extending between the insert hole and the corner portion, The plurality of recesses include a first recess into which the first protrusion of the mounting portion is inserted when the cutting insert is supported by the mounting portion, and a second recess into which the second protrusion of the mounting portion is inserted when the cutting insert is supported by the mounting portion. The first recess contacts the first protrusion at two points, The second recess has a side wall spaced apart from the second protrusion of the mounting portion and a face that contacts the second protrusion. Cutting tool assembly.

10. The aforementioned mounting portion is a shim, The holder is configured to fix the cutting insert and the shim. The cutting tool assembly according to claim 9.

11. The mounting portion is the bottom surface of the pocket portion of the holder. The cutting tool assembly according to claim 9.

12. The first recess contacts the first protrusion of the shim at two points, The second recess has a bottom surface that contacts the second protrusion of the shim. The cutting tool assembly according to claim 10.

13. The first recess and the first protrusion of the shim are in contact with each other at a pair of first contact points. The bottom surface of the second recess and the second protrusion of the shim are in contact with each other at the second contact point. The line connecting one of the first contact points and the second contact point has an inclination angle with respect to a reference plane that is perpendicular to the extension direction of the insert hole. The cutting tool assembly according to claim 12.

14. Each of the upper and lower surfaces of the cutting insert includes an inclined surface perpendicular to the extension direction of the insert hole and inclined with respect to the reference plane, The upper surface and the lower surface are symmetrical to each other. Each of the aforementioned upper and lower surfaces is provided with three corner portions. The cutting tool assembly according to claim 13.

15. When the cutting insert is mounted in the holder, the upper surface of the cutting insert forms an angle of -5° to +5° with respect to the center line of the workpiece to be cut by the cutting insert. The cutting tool assembly according to claim 14.

16. Two corner portions are provided on the upper surface, and the two corner portions are rotationally symmetrical by 180° with respect to the central axis of the insert hole. The cutting tool assembly according to claim 13.

17. When the cutting insert is mounted in the holder, only the side of the cutting insert located opposite the first recess contacts the holder. The cutting tool assembly according to claim 13.

18. The cutting blade located in one of the first recesses of the cutting insert forms an angle of less than 90° with respect to the rotational axis of the workpiece, and the cutting blade located in the other of the first recesses of the cutting insert forms an angle of more than 90° with respect to the rotational axis of the workpiece. The cutting tool assembly according to claim 13.

19. A cutting insert bonded to a shim to which the cutting insert is secured, The aforementioned cutting insert is An upper surface, a lower surface, and a plurality of side surfaces extending between the upper surface and the lower surface, An insert hole that penetrates the upper surface and the lower surface and has a central axis that is a reference having rotational symmetry, at least the upper surface At least two corner portions, each having a pair of cutting blades formed at the connection point of two adjacent sides, with each corner portion having a pair of cutting blades formed at the intersection point of the upper surface and the two adjacent sides, and a first recess formed on the lower surface adjacent to each corner portion, and At least two second recesses, spaced apart from the first recess and formed on the lower surface, each of which has a second recess side wall Includes, In the plan view of the lower surface, the first recess has a different shape from the two second recesses. The aforementioned shim is, The upper surface of the shim, the lower surface of the shim, and a plurality of shim sides extending between the upper surface of the shim and the lower surface of the shim, A shim hole that penetrates the upper surface and lower surface of the shim and has a central axis whose upper surface is a reference that is not rotationally symmetric, At least one shim corner portion formed at the connection point of the sides of two adjacent shims, A first protrusion formed on the upper surface of the shim adjacent to at least one shim corner portion, and At least two second protrusions are formed on the upper surface of the shim, spaced apart from the at least one shim corner portion, and each has a second protrusion side wall. Includes, In the plan view of the upper surface of the shim, the first protrusion has a different shape from the second protrusion. The first recess contacts the first protrusion at two points, The second recess has a side wall spaced apart from the second protrusion of the shim and a face that contacts the second protrusion. A cutting insert coupled with a shim.

20. The cutting insert has a triangular shape, having three sides, three corner portions equipped with cutting blades, three first recesses, and three second recesses, each of which is located between one of the first recesses and the insert hole. The upper surface of the shim has exactly one first protrusion and exactly two second protrusions. The first recess contacts the first protrusion at a pair of first contact points spaced apart from each other. The two second recesses contact the upper surfaces of the two second protrusions at each of the second contact points. The line connecting one of the first contact points and the second contact point located on the same side as the first contact point with respect to the insert hole has a non-zero inclination angle p with respect to a reference plane RP which is perpendicular to the extension direction of the insert hole. A cutting insert coupled with a shim as described in claim 19.

21. The cutting insert has a diamond shape, having four sides, two corner portions with cutting blades, two first recesses located along a virtual line extending between the two corner portions and separated by the insert hole, and four second recesses, each of which is located at the intersection of the lower surface and another of the four sides. The upper surface of the shim has exactly one first protrusion and exactly two second protrusions. One of the first recesses contacts the first convex portion at a pair of first contact points spaced apart from each other. Two of the four second recesses contact the upper surfaces of the two second protrusions at the second contact point. The line connecting one of the first contact points and the second contact point located on the same side as the first contact point with respect to the insert hole has a non-zero inclination angle p with respect to a reference plane RP which is perpendicular to the extension direction of the insert hole. A cutting insert coupled with a shim as described in claim 19.

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