CUTTING INSERT AND ASSEMBLY OF TOOL HOLDER EQUIPPED WITH SAME

Abstract

A cutting insert of the present invention includes an upper surface, a lower surface, a side surface, a cutting edge, and a mounting hole penetrating the upper surface and the lower surface, in which the cutting edge includes a main cutting edge, a corner cutting edge extending from the main cutting edge, and a sub-cutting edge extending from the corner cutting edge, the side surface includes a main cutting edge flank surface and a sub-cutting edge flank surface, the main cutting edge flank surface includes a first main cutting edge flank surface extending from the main cutting edge, and a second main cutting edge flank surface extending from the lower surface, the sub-cutting edge flank surface includes a first sub-cutting edge flank surface extending from the sub-cutting edge, and a second sub-cutting edge flank surface extending from the lower surface, the first sub-cutting edge flank surface and the second sub-cutting edge flank surface together form a stepped portion, and the second sub-cutting edge flank surface protrudes from an imaginary plane extending from the first sub-cutting edge flank surface.

Claims

1. A cutting insert comprising an upper surface, a lower surface, a side surface, a cutting edge, and a mounting hole penetrating the upper surface and the lower surface, wherein the cutting edge includes a main cutting edge, a corner cutting edge extending from the main cutting edge, and a sub-cutting edge extending from the corner cutting edge, the side surface includes a main cutting edge flank surface and a sub-cutting edge flank surface, the main cutting edge flank surface includes a first main cutting edge flank surface extending from the main cutting edge, and a second main cutting edge flank surface extending from the lower surface, the sub-cutting edge flank surface includes a first sub-cutting edge flank surface extending from the sub-cutting edge, and a second sub-cutting edge flank surface extending from the lower surface, the first sub-cutting edge flank surface and the second sub-cutting edge flank surface together form a stepped portion, and the second sub-cutting edge flank surface protrudes from an imaginary plane extending from the first sub-cutting edge flank surface.

2. The cutting insert according to claim 1, wherein a first locking jaw is formed between the first sub-cutting edge flank surface and the second sub-cutting edge flank surface by the stepped portion.

3. The cutting insert according to claim 1, wherein, when the cutting insert is viewed into the lower surface, four enlarged support surfaces are formed outside an intersection line of the lower surface and an extension plane of a surface of the first sub-cutting edge flank surface.

4. The cutting insert according to claim 1, wherein a width from the upper surface to the lower surface of the first main cutting edge flank surface is constant.

5. An assembly of a cutting insert and a tool holder, equipped with the cutting insert according to claim 1 or 2, wherein the tool holder includes a pocket portion in which the cutting insert is seated, the pocket portion includes a first side mounting surface, a second side mounting surface, a recess portion positioned between the first side mounting surface and the second side mounting surface, and a bottom mounting surface, the recess portion includes a first recess portion in a direction away from the bottom mounting surface, and a recess surface portion that is stepped with the first recess portion and protrudes relatively further from a virtual extension plane of a surface of the first recess portion, and the first recess portion and the recess surface portion form a second locking jaw.

6. The assembly according to claim 5, wherein the second main cutting edge flank surface of the cutting insert is supported on the first side mounting surface, and another second main cutting edge flank surface of the cutting insert is supported on the second side mounting surface, and the lower surface is supported on the bottom mounting surface, and the first sub-cutting edge flank surface forms a predetermined gap with the recess surface portion, in which the first locking jaw protrudes into a space formed in the first recess portion.

1. A cutting insert comprising an upper surface, a lower surface, a side surface, a cutting edge, and a mounting hole penetrating the upper surface and the lower surface, wherein the cutting edge includes a main cutting edge, a corner cutting edge extending from the main cutting edge, and a sub-cutting edge extending from the corner cutting edge, the side surface includes a main cutting edge flank surface and a sub-cutting edge flank surface, the main cutting edge flank surface includes a first main cutting edge flank surface extending from the main cutting edge, and a second main cutting edge flank surface extending from the lower surface, the sub-cutting edge flank surface includes a first sub-cutting edge flank surface extending from the sub-cutting edge, and a second sub-cutting edge flank surface extending from the lower surface, the first sub-cutting edge flank surface and the second sub-cutting edge flank surface together form a stepped portion, and the second sub-cutting edge flank surface protrudes from an imaginary plane extending from the first sub-cutting edge flank surface.

2. The cutting insert according to claim 1, wherein a first locking jaw is formed between the first sub-cutting edge flank surface and the second sub-cutting edge flank surface by the stepped portion.

3. The cutting insert according to claim 1, wherein, when the cutting insert is viewed into the lower surface, four enlarged support surfaces are formed outside an intersection line of the lower surface and an extension plane of a surface of the first sub-cutting edge flank surface.

4. The cutting insert according to claim 1, wherein a width from the upper surface to the lower surface of the first main cutting edge flank surface is constant.

5. An assembly of a cutting insert and a tool holder, equipped with the cutting insert according to claim 1, wherein the tool holder includes a pocket portion in which the cutting insert is seated, the pocket portion includes a first side mounting surface, a second side mounting surface, a recess portion positioned between the first side mounting surface and the second side mounting surface, and a bottom mounting surface, the recess portion includes a first recess portion in a direction away from the bottom mounting surface, and a recess surface portion that is stepped with the first recess portion and protrudes relatively further from a virtual extension plane of a surface of the first recess portion, and the first recess portion and the recess surface portion form a second locking jaw.

6. The assembly according to claim 5, wherein the second main cutting edge flank surface of the cutting insert is supported on the first side mounting surface, and another second main cutting edge flank surface of the cutting insert is supported on the second side mounting surface, and the lower surface is supported on the bottom mounting surface, and the first sub-cutting edge flank surface forms a predetermined gap with the recess surface portion, in which the first locking jaw protrudes into a space formed in the first recess portion.

7. An assembly of a cutting insert and a tool holder, equipped with the cutting insert according to claim 2, wherein the tool holder includes a pocket portion in which the cutting insert is seated, the pocket portion includes a first side mounting surface, a second side mounting surface, a recess portion positioned between the first side mounting surface and the second side mounting surface, and a bottom mounting surface, the recess portion includes a first recess portion in a direction away from the bottom mounting surface, and a recess surface portion that is stepped with the first recess portion and protrudes relatively further from a virtual extension plane of a surface of the first recess portion, and the first recess portion and the recess surface portion form a second locking jaw.

8. The assembly according to claim 7, wherein the second main cutting edge flank surface of the cutting insert is supported on the first side mounting surface, and another second main cutting edge flank surface of the cutting insert is supported on the second side mounting surface, and the lower surface is supported on the bottom mounting surface, and the first sub-cutting edge flank surface forms a predetermined gap with the recess surface portion, in which the first locking jaw protrudes into a space formed in the first recess portion.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG. 1 is a perspective view of a cutting insert according to an exemplary embodiment of the present invention.

[0021] FIG. 2 is a view of the cutting insert of FIG. 1 viewed from above.

[0022] FIG. 3 is a side view of the cutting insert of FIG. 1 viewed from a direction of a main cutting edge flank surface.

[0023] FIG. 4 is a side view of the cutting insert of FIG. 1 viewed from a direction of a sub-cutting edge flank surface.

[0024] FIG. 5 is a view of the cutting insert of FIG. 1 viewed from a lower surface.

[0025] FIG. 6 shows an assembly of the cutting insert of FIG. 1 and a tool holder.

[0026] FIG. 7 is a partially enlarged view of the pocket portion of the tool holder of FIG. 6.

[0027] FIG. 8 shows the assembly of FIG. 6, with the cutting insert being mounted to the pocket portion.

[0028] FIG. 9 is a view showing how the torque is decreased due to cutting force in the assembly of FIG. 6.

[0029] FIGS. 10 and 11 show an example of a related cutting insert.

BEST MODE FOR EMBODYING INVENTION

[0030] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. However, it will be understood that the present invention can be implemented in various other different forms and should not be construed as being limited to certain examples described herein.

[0031] As shown in FIG. 1, a cutting insert 100 according to one embodiment of the present invention includes an upper surface 1, a lower surface 2, a side surface 3, a cutting edge 4, and a mounting hole 5 penetrating the upper surface 1 and the lower surface 2. When viewed from the upper surface 1, the cutting insert 100 of the present embodiment has an approximate quadrangular shape and is a one-sided cutting insert. In addition, it may be approximately 180° rotationally symmetrical with respect to a virtual center line Cl passing through the center of the mounting hole 5.

[0032] In addition, the cutting insert 100 is a positive type cutting insert. For reference, by the “positive type,” it refers to the type in which an angle α formed between an extension line P3 of the lower surface and an extension line P1 of the flank surface is the obtuse angle, as shown in FIG. 4. In this case, the angle α refers to an angle toward the upper surface of the cutting insert. In addition, by the “negative type,” it refers to the type in which the angle α is the right angle.

[0033] The cutting edge 4 includes a main cutting edge 41, a corner cutting edge 42 extending from the main cutting edge 41, and a sub-cutting edge 43 extending from the corner cutting edge 42.

[0034] The side surface 3 includes a main cutting edge flank surface 31 and a sub-cutting edge flank surface 33.

[0035] The main cutting edge flank surface 31 includes a first main cutting edge flank surface 311 extending from the main cutting edge 41 and a second main cutting edge flank surface 312 extending from the lower surface 2.

[0036] The sub-cutting edge flank surface 33 includes a first sub-cutting edge flank surface 331 extending from the sub-cutting edge 43 and a second sub-cutting edge flank surface 332 extending from the lower surface 2.

[0037] As shown in FIGS. 1 and 4, the first sub-cutting edge flank surface 331 and the second sub-cutting edge flank surface 332 together form a stepped portion, and the second sub-cutting edge flank surface 332 protrudes from an imaginary plane P1 extending from the first sub-cutting edge flank surface 331. A first locking jaw 333 is formed between the first sub-cutting edge flank surface 331 and the second sub-cutting edge flank surface 332 by the stepped portion.

[0038] In this way, as the second sub-cutting edge flank surface 332 protrudes relatively further from the first sub-cutting edge flank surface 331, as shown in FIG. 5, when the cutting insert is viewed from the lower surface, compared to the related cutting insert, there are four enlarged support surfaces 21 provided outside an intersection line L1 of the imaginary plane P1 and the lower surface 2. In this case, by “outside the intersection line L1,” it refers to a surface radially outside the intersection line L1 with respect to a through hole 5. Through this, even when the clearance angle of the first sub-cutting edge flank surface 331 is increased, the area of the lower surface 2 in contact with the tool holder is not reduced, and accordingly, it is possible to improve machining performance without sacrificing mounting stability. In contrast, the related cutting insert has a problem in that, when the clearance angle of the sub-cutting edge flank surface is increased in order to improve machining performance, the area of the lower surface is also reduced, resulting in poor mounting stability.

[0039] Meanwhile, as shown in FIG. 3, the width (w) in the direction from the upper surface 1 to the lower surface 2 of the first main cutting edge flank surface 311 is constant. Through this, it is possible to ensure the maximum area of the second main cutting edge flank surface 312 in contact with the tool holder, and thus improve the stability of mounting to the tool holder. On the other hand, the related cutting insert has a problem in that the width of the main cutting edge flank surface extending from the main cutting edge is expanded from one direction to the other direction, and as a result, the contact area with the tool holder is reduced, resulting in poor stability of mounting to the tool holder (see FIG. 10).

[0040] Hereinafter, the assembly of the cutting insert 100 and a tool holder 500 equipped with the cutting insert described above will be described with reference to FIGS. 6 to 9.

[0041] As shown in FIGS. 6 and 7, the tool holder (cutter) 500 includes a pocket portion 501 in which the cutting insert 100 is seated.

[0042] Specifically, the pocket portion 501 includes a first side mounting surface 502, a second side mounting surface 503, a recess portion 504 positioned between the first side mounting surface 502 and the second side mounting surface 503, and a bottom mounting surface 505.

[0043] In this example, the recess portion 504 includes a first recess portion 5041 and a recess surface portion 5042, respectively positioned in a direction away from the bottom mounting surface 505.

[0044] As shown in FIG. 8, the recessed surface portion 5042 is stepped from the first recess portion 5041 and protrudes relatively further from an imaginary extension plane P2 of the surface of the first recess portion 5041. Through this, the first recess portion 5041 and the recessed surface portion 5042 form a second locking jaw 5043.

[0045] Meanwhile, the second main cutting edge flank surface 312 of the cutting insert 100 is supported on the first side mounting surface 502, the other second main cutting edge flank surface 312 of the cutting insert 100 is supported on the second side mounting surface 503, and the lower surface 2 is supported on the bottom mounting surface 505.

[0046] As shown in FIG. 8, in a state in which the cutting insert 100 is seated in the pocket 501 of the tool holder 500, the first sub-cutting edge flank surface 331 forms a predetermined gap (a) with the recess surface portion 5042. At this time, the first locking jaw 333 of the cutting insert 100 protrudes into a space S formed in the first recess portion 5041 of the tool holder 500. Through this, when the impact from the cutting process is applied to the cutting insert during cutting, the first locking jaw 333 of the cutting insert 100 comes into contact with the second locking jaw 5043 of the tool holder 500 and is caught, thereby preventing the cutting insert 100 from separating from the bottom mounting surface 505 of the pocket portion 501.

[0047] In addition, as shown in FIG. 9, for the cutting insert 100, the lower surface 2 is widened, and thus the torque (moment) by the cutting force F is reduced, and accordingly, the mounting stability is further increased. For reference, in FIG. 9, L2 represents a vertical distance between the support point and the cutting force F in the related cutting insert, and L1 represents a vertical distance between the support point and the cutting force F in the cutting insert of the present invention, respectively.

[0048] As described above, with the cutting insert and the tool holder according to the embodiment of the present invention, it is ensured that the second main cutting edge flank surface is in contact with the tool holder in as large area as possible so as to withstand the impact applied to the positive type cutting insert during cutting, and also, the configuration of the first locking jaw of the cutting insert and the second locking jaw of the tool holder can prevent the cutting insert from falling off.

[0049] Although the present invention has been described in connection with some examples herein, the present invention should not be limited to those examples only, and various other changes and modifications made by those skilled in the art from the basic concept of the disclosure are also within the scope of the claims appended herein.

INDUSTRIAL APPLICABILITY

[0050] The present invention can be used for a cutting tool for cutting a workpiece.