CN118237637A - Embedded cutting blade and drilling tool comprising same - Google Patents

Abstract

The insert cutting insert may include a lower face, an upper face, a side face, a through hole, and a cutting portion. The cutting portion includes: a corner edge comprising a first corner edge disposed at one end and a second corner edge disposed at the other end; a first cutting edge extending obliquely from the first corner edge to the second corner edge; a first convex edge extending from the first cutting edge to the second corner edge and protruding away from the through hole; a second cutting edge extending obliquely from the first convex edge to the second corner edge; a concave edge extending from the second cutting edge to the second corner edge and recessed in a direction approaching the through hole; a third cutting edge extending obliquely from the concave edge toward the second corner edge; a second convex edge extending from the third cutting edge to the second corner edge and protruding away from the through hole; and a fourth cutting edge extending obliquely from the second convex edge toward the second corner edge. Therefore, the cutting quality is improved, and the cutting load is effectively distributed.

Description

Embedded cutting blade and drilling tool comprising same

Technical Field

The present invention relates to an insert type cutting insert and a drilling tool including the insert, and more particularly, to an insert type cutting insert capable of preventing vibration and breakage of a tool to achieve stable machining and a cutting tool including the insert.

Background

The indexable drill is a cutting edge exchange drill used for assembling an indexable embedded cutting blade at the front end of a drill body, has better economical efficiency than an integral drill with an integrated body and cutting edge, and is widely used for machining metal holes and the like.

In the early indexable drills used square insert cutting inserts, the linear cutting edges had a defect that the cutting load generated during cutting could not be uniformly handled, and therefore improvement in various aspects such as chip handling and surface quality of the machined surface generated when the workpiece was cut was demanded.

As a result of various studies to solve these problems, it has been found that the phenomenon of using square insert cutting inserts having divided cutting edges is common. The insert cutting insert is formed by dividing a cutting edge of one side into a plurality of partial edges, the partial edges are connected by a convex curve or a concave curve, and the cutting edge portions are provided for the same side.

The conventional drill body and the insert cutting insert are described in detail below. Fig. 1 is a schematic view showing a conventional drill body to which an insert type cutting insert is attached. Fig. 2 is a schematic view showing a conventional insert cutting insert. Referring to fig. 1 and 2, a conventional drill tool may include a drill body D 'and an insert I'.

The bit body D 'may incorporate an insert cutting insert I' at the end. Specifically, the insert cutting insert I 'is provided in plurality and may be coupled to the inner side and the outer side of the bit body D', respectively.

The insert I ' may include a cutting portion I ' performing cutting, and the cutting portion 1 may include a first corner edge 111', a first cutting edge 12', a first convex edge 13', a second cutting edge 14', a concave edge 15', a third cutting edge 16', and a second corner edge 113'. Further, as described above, the one side cutting edge of the cutting portion 1' is divided into a plurality of partial edges, and the partial edges are connected by a convex curve or a concave curve.

The angle θ2 'of the second cutting edge 14' with respect to the center line C1 'is the same as the angle θ3' of the third cutting edge 16 'with respect to the center line C1'. Specifically, the angle θ2 'of the second cutting edge 14' with respect to the center line C1 'and the angle θ3' of the third cutting edge 16 'with respect to the center line C1' are 5 degrees to 7 degrees, and the angle θ1 'of the first cutting edge 12' with respect to the center line L is 14 degrees to 16 degrees.

The conventional drill body D 'and the insert I' are divided into a plurality of partial blades, and thus the problem of cutting quality is solved to some extent, but the cutting quality is not optimal, and the cutting load is not optimally balanced, so that there is a possibility that tool vibration and breakage occur.

Therefore, research into insert cutting inserts that achieve optimal balance of cutting loads by dividing a plurality of partial edges to an optimal level is actively being conducted.

Disclosure of Invention

Technical problem

According to various embodiments of the present invention, it is an object to provide an insert cutting insert having a plurality of partial edges (cutting edges) designed to be partable into an optimal number.

According to various embodiments of the present invention, it is an object to provide an insert cutting insert in which the angle of the divided cutting edge formation is optimally designed, and the optimum balance of the cutting load is achieved.

According to various embodiments of the present invention, it is an object to provide an insert type cutting insert having side surfaces including a projection and a clearance surface, which can be firmly coupled to a bit body.

According to various embodiments of the present invention, it is an object to provide a drill body having a groove portion, in which the insert cutting insert is effectively and firmly coupled.

Technical proposal

According to various embodiments of the present invention, an insert cutting insert may be provided in which four partial edges (cutting edges) are connected by two convex curves and one concave curve.

Specifically, it may include: the following; an upper surface provided separately from the lower surface; a side connecting the upper face and the lower face; a through hole formed through the center of the upper surface; a cutting portion formed along the outer periphery of the upper surface and cutting the material to be cut.

The cutting part may include: a corner edge comprising a first corner edge disposed at one end and a second corner edge disposed at the other end; a first cutting edge extending obliquely from the first corner edge to the second corner edge; a first convex edge extending from the first cutting edge toward the second corner edge and protruding in a direction away from the through hole; a second cutting edge extending obliquely from the first convex edge toward the second corner edge; a concave edge extending from the second cutting edge toward the second corner edge and recessed in a direction approaching the through hole; a third cutting edge extending obliquely from the concave edge toward the second corner edge; a second convex edge extending from the third cutting edge toward the second corner edge and protruding away from the through hole; and a fourth cutting edge extending obliquely from the second convex edge toward the second corner edge.

Preferably, the first cutting edge is inclined to extend from the first corner edge in a direction away from the through hole; the second cutting edge extends obliquely in a direction opposite to the first cutting edge; the third cutting edge and the fourth cutting edge extend obliquely in the same direction as the first cutting edge.

Preferably, the angle θ1 formed by the first cutting edge and a center line C1 passing through the center of the through hole is the same as or greater than the angle θ3 formed by the third cutting edge and the center line C1.

Preferably, the angle θ3 formed by the third cutting edge and the center line C1 is formed larger than the angle θ4 formed by the fourth cutting edge and the center line C1.

Preferably, the angle θ1 formed by the first cutting edge and the center line C1 is 5 to 10 degrees, the angle θ3 formed by the third cutting edge and the center line C1 is 4 to 7 degrees, and the angle θ4 formed by the fourth cutting edge and the center line is 0 to 3 degrees.

Preferably, the angle θ1 formed by the first cutting edge and the center line C1 is 6 to 9 degrees, the angle θ3 formed by the third cutting edge and the center line is 5 to 6 degrees, and the angle θ4 formed by the fourth cutting edge and the center line is 1 to 2 degrees.

Preferably, the angle θ1 formed by the first cutting edge and the center line C1 and the angle θ2 formed by the second cutting edge and the center line C1 are different within 3 degrees.

Preferably, the angle θ2 formed by the second cutting edge and the center line C1 is between 5 degrees and 10 degrees.

Preferably, the angle θ2 formed by the second cutting edge and the center line C1 is between 6 degrees and 9 degrees.

Preferably, the angle θ1 formed by the first cutting edge and the center line C1 is formed larger than the angle θ2 formed by the second cutting edge and the center line C1.

Preferably, the angle θ1 formed by the first cutting edge and the center line C1 is formed smaller than the angle θ2 formed by the second cutting edge and the center line C1.

Preferably, the extension length of the second convex edge is formed shorter than the extension length of the first convex edge.

Preferably, the side surface includes: a clearance surface extending from the lower face toward the cutting portion; and a projection extending from the clearance surface toward the upper surface and projecting outward from the clearance surface.

Preferably, the height H1 from the lower face to the clearance face is 0.6 to 0.8 of the height H2 from the lower face to the cutting portion.

Preferably, the height H1 from the lower face to the clearance face is 0.65 to 0.75 of the height H2 from the lower face to the cutting portion.

Preferably, the clearance surface includes: an angular clearance surface comprising a first angular clearance surface extending toward the first angular edge and a second angular clearance surface extending toward the second angular edge; a first clearance surface connected to the first angular clearance surface and extending toward the first cutting edge, the first convex edge, the second cutting edge, and the concave edge; and a second clearance surface connected to the second angular clearance surface and extending toward the concave edge, the third cutting edge, the second convex edge, and the fourth cutting edge.

Preferably, the angle α formed by the first clearance surface and the second clearance surface is formed as an obtuse angle.

Preferably, the angle α formed by the first clearance surface and the second clearance surface may reach 150 degrees to 180 degrees.

According to various embodiments of the present invention, a bit body incorporating the insert as described above may be provided.

Specifically, the method comprises the following steps: a body portion having at least a portion extending in a spiral shape; a groove portion disposed at an end of the body portion and to which the insert cutting blade is coupled. The groove portion includes: a bottom surface of the lower contact; and a wall surface connected to the bottom surface and contacting the side surface. The wall surface includes: a first wall portion connected to the bottom surface; a second wall portion extending obliquely while the first wall portion is away from the bottom surface; and a third wall portion recessed inward from the second wall portion. The second wall portion is supported in contact with the clearance surface.

Preferably, the cutting portion includes: a first cutting portion; a second cutting portion connected to the first cutting portion; a third cutting portion connected to the second cutting portion; and a fourth cutting portion connected to the third cutting portion and the first cutting portion. The wall surface includes: a first wall surface arranged at a position corresponding to the first cutting portion; a second wall surface disposed at a position corresponding to the second cutting portion.

Preferably, the angle β formed by the second wall portion arranged on the first wall surface and the second wall portion arranged on the second wall surface may form an acute angle.

Preferably, the angle β formed by the second wall portion arranged on the first wall surface and the second wall portion arranged on the second wall surface is 70 degrees to 90 degrees.

Preferably, the angle β formed by the second wall portion arranged on the first wall surface and the second wall portion arranged on the second wall surface is 75 degrees to 85 degrees.

Advantageous effects

According to various embodiments of the present invention, it is advantageous that,

It is possible to provide an insert cutting insert provided with a plurality of partial edges (cutting edges) designed to be partable into an optimal number;

An insert cutting insert in which the angle of the divided cutting edge is optimally designed to achieve optimal balance of the cutting load can be provided;

it is possible to provide an insert type cutting insert having a side surface including a projection and a clearance surface and firmly coupled to a bit body;

it is possible to provide a drill body having a groove portion and capable of effectively and firmly coupling the insert cutting insert.

Drawings

FIG. 1 is a schematic view showing a conventional drill bit body incorporating an insert cutting insert therein;

FIG. 2 is a schematic view showing a conventional insert cutting insert;

FIG. 3 is a perspective view of a bit body according to one embodiment of the present invention;

FIG. 4 is a perspective view of an insert according to an embodiment of the present invention;

FIG. 5 is a top view of an insert according to an embodiment of the present invention;

FIG. 6 is a side view of an insert according to an embodiment of the present invention;

FIG. 7 is a bottom view of an insert according to an embodiment of the present invention;

FIG. 8 is a schematic view of a bit body pocket according to an embodiment of the present invention;

FIG. 9 is a schematic view showing angles formed by second wall portions arranged at mutually different positions;

FIG. 10 is a schematic view showing the rotation of an inside and outside insert cutting blades according to an embodiment of the present invention;

Fig. 11 is a schematic view showing the wear degree of a conventional insert and an insert according to an embodiment of the present invention.

[ Symbolic description ]

D: a bit body; i: an insert cutting insert;

1: a cutting portion; 3: a side surface;

5: the upper surface; 7: the following;

8: a main body portion; 9: a groove portion.

Detailed Description

The following describes the technical solutions in the embodiments of the present invention in detail with reference to the drawings in the embodiments of the present invention, but the described embodiments are some embodiments of the present invention, but not all embodiments. Those skilled in the art can implement the invention in various different forms, but all other embodiments obtained without making any inventive effort are within the scope of the invention. For the sake of more clear description, portions not related to the description are omitted, and like reference numerals are given to like portions in the description.

In this specification, repetitive description of the same members is omitted.

In this specification, the description that a certain component is "connected" or "connected" to another component may mean directly connected or directly connected to the other component, but it should be understood that the other component exists in the middle. Conversely, when a component is described as being "directly connected" or "directly connected" to another component, it is to be understood that the other component is not present in the middle.

The terminology used in the description presented herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

In the present specification, the singular form may include the plural form unless specifically stated otherwise in the sentence.

In this specification, the terms "comprises" and "comprising" and the like are used to specify the presence of stated features, integers, steps, actions, components, parts, or groups thereof, but do not preclude the presence or addition of one or more other features or integers, steps, actions, components, parts, or groups thereof.

The term "and/or" in the present specification includes a combination of a plurality of items or any one of a plurality of items. In the present specification, a 'or B' may include "a", "B", or "all of a and B".

Fig. 3 is a perspective view of a bit body according to an embodiment of the present invention. According to fig. 3, a drill tool of an embodiment of the present invention may include a drill body D and an insert I.

The bit body D is coupled to the driving means at one end and may be coupled to the insert I at the other end. Further, the bit body D is rotated by the driving of the driving device, and the cutting blade I coupled to the other end of the bit body D can process the workpiece by the rotation of the bit body D.

Specifically, the bit body D may include a body portion 8 and a slot portion 9. The main body 8 may have an external appearance of the bit body D, and may be coupled to a driving device to obtain power.

The bit body D may be cylindrical in shape so that the coupling to one end of the driving device is easy, and the other end formed by the groove 9 may be spiral in shape. Further, the bit body D may be extended at least partially in a spiral shape in order to facilitate boring, drilling or cutting of the material to be cut.

The groove 9 is provided at an end of the body 8, and can be coupled with the insert I. The end of the main body 8 is as described above, and may be the other end of the main body 8. The details of the groove 9 will be described later.

Fig. 4 is a perspective view of an insert cutting insert according to an embodiment of the present invention. According to fig. 4, an insert I according to an embodiment of the present invention may include a lower face 7, an upper face 5, a side face 3, a through hole a and a cutting portion 1.

The lower surface 7 is disposed in the groove 9 and can be coupled to the bit body D. The lower surface 7 is a surface positioned on the lower side with reference to fig. 4, and can be considered to be positioned on the upper side in terms of viewing angle.

The upper surface 5 may be provided separately from the lower surface 7. Further, the upper surface 5 may be formed side by side with the lower surface 7, and may be regarded as being located on the upper side with reference to fig. 4, or may be regarded as being located on the lower side with reference to the angle of observation. The upper face 5 and the lower face 7 have corresponding shapes, and the sectional area is such that the upper face 5 can be formed larger than the lower face 7.

The through hole a is formed through the center of the upper surface 5. Further, the through hole a may be formed from the center of the upper surface 5 to the center of the lower surface 7, and the separate fastening member may be coupled to the groove 9 after passing through the through hole a, thereby fixing the insert I to the bit body D.

The cutting portion 1 is formed along the outer periphery of the upper surface 5, and can cut a workpiece. Further, by the rotation of the bit body D, the cutting portion 1 can directly contact the workpiece, and the workpiece can be bored, drilled, or cut.

Fig. 5 is a top view of an insert according to an embodiment of the present invention. According to fig. 5, the cutting part 1 according to an embodiment of the present invention may include a corner edge 11, a first cutting edge 12, a first convex edge 13, a second cutting edge 14, a concave edge 15, a third cutting edge 16, a second convex edge 17, and a fourth cutting edge 18.

The corner edge 11 may be disposed at the outermost edge of the cutting portion 1, and may include a first corner edge 111 disposed at one end and a second corner edge 113 disposed at the other end. The corner blade 11 may further include a plurality of cutting portions 1, and the plurality of cutting portions 1 may be connected.

The first cutting edge 12 may extend obliquely from the first corner edge 111 to the second corner edge 113. Further, the first cutting edge 12 extends at a predetermined inclination and directly contacts the workpiece to process the workpiece. The direction in which the first cutting edge 12 extends may be the first direction E1.

The first convex edge 13 is formed to protrude in a direction away from the through hole a so that the first cutting edge 12 extends toward the second corner edge 113. Further, the first convex edge 13 is formed to protrude in a second direction E2 opposite to the first direction E1 after extending in the first direction E1 of a predetermined length on the first cutting edge 12.

The first convex edge 13 has a structure in which one cutting edge is divided into a plurality of partial edges (cutting edges), and is capable of facilitating the disposal of chips generated when a workpiece is cut, improving the quality of a machined surface, and the like.

The second cutting edge 14 may extend obliquely from the first convex edge 13 to the second corner edge 113. Further, the second cutting edge 14 extends at a predetermined inclination, and can directly contact the workpiece to process the workpiece. And the direction in which the second cutting edge 14 extends may be the second direction E2.

The concave edge 15 extends from the second cutting edge 14 toward the second corner edge 113, and may be recessed in a direction approaching the through hole a. Further, the concave edge 15 is formed to extend in a second direction E2 of a predetermined length from the second cutting edge 14, then extend in a first direction E1 opposite to the second direction E2, and then be recessed.

The concave edge 15 has a structure in which one cutting edge is divided into a plurality of partial edges (cutting edges) together with the first convex edge 13, so that the chip generated when the workpiece is cut can be easily handled, and the quality of the machined surface can be improved.

The third cutting edge 16 may extend obliquely from the first concave edge 15 to the second corner edge 113. Further, the third cutting edge 16 extends at a predetermined inclination and directly contacts the workpiece, thereby processing the workpiece. The direction in which the third cutting edge 16 extends may be the first direction E1.

The second convex edge 17 is formed to protrude in a direction away from the through hole a from the third cutting edge 12 toward the second corner edge 113. Further, the second convex edge 17 is formed to protrude from the third cutting edge 16 in a second direction E2 opposite to the first direction E1 after extending in the first direction E1 of a predetermined length.

The second convex edge 17 has a structure in which one cutting edge is divided into a plurality of partial edges (cutting edges), and is capable of facilitating the disposal of chips generated when a workpiece is cut, improving the quality of a machined surface, and the like.

The second convex edge 17 is formed to be shorter than the first convex edge 13, so that the structural rigidity of the entire cutting portion 1 can be maintained and the processing quality of the workpiece can be improved.

The fourth cutting edge 18 may extend obliquely from the second convex edge 17 to the second corner edge 113. Further, the fourth cutting edge 18 extends at a predetermined inclination, and can directly contact the workpiece to process the workpiece. And the direction in which the fourth cutting edge 18 extends may be the first direction E1.

The fourth cutting edge 18 and the third cutting edge 16 extend obliquely in the same direction, and the second convex edge 17 is satisfactorily connected to ensure a longer cutting edge length, and the contact length with the workpiece is increased, thereby reducing the cutting load per unit area.

Further, the first, second, third and fourth cutting edges 12, 14, 16 and 18 may be formed as curves having a straight line or a predetermined or more radius of curvature of a similar angle. Accordingly, the load can be effectively distributed to the first cutting edge 12, the second cutting edge 14, the third cutting edge 16, and the fourth cutting edge 18.

In summary, the cutting portion 1 may include the first cutting edge 12, the second cutting edge 14, the third cutting edge 16, and the fourth cutting edge 18, and the first convex edge 13, the second convex edge 17, and the concave edge 15 connected thereto.

Further, the cutting edge of one side is divided into a plurality of partial edges, and each partial edge is connected by a convex curve or a concave curve, so that chips generated when a material to be cut is cut can be effectively processed, and the surface quality of a machined surface can be improved.

In addition, the insert cutting insert I may have a plurality of cutting portions 1. Specifically, the insert I may have four sides of a square shape, and each side may be provided with the cutting portion 1. Further, the cutting portion 1 may include a first cutting portion 1a, a second cutting portion 1b, a third cutting portion 1c, and a fourth cutting portion 1d.

More specifically, the second cutting portion 1b is connected to the first cutting portion 1a, the third cutting portion 1c is connected to the second cutting portion 1b, and the fourth cutting portion 1d may be connected to the third cutting portion 1c and the first cutting portion 1a.

The first cutting portion 1a, the second cutting portion 1b, the third cutting portion 1c, and the fourth cutting portion 1d may all be formed identically. Further, the first, second, third and fourth cutting portions 1a, 1b, 1c and 1d may include first, second, third and fourth cutting edges 12, 14, 16 and 18, respectively, and first, second, and concave edges 13, 17 and 15 connecting the same.

The following description is equally applicable to the first cutting portion 1a, the second cutting portion 1b, the third cutting portion 1c, and the fourth cutting portion 1d.

The first cutting edge 12 extends obliquely from the first corner edge 111 in a direction away from the through hole a, the second cutting edge 14 extends obliquely in a direction opposite to the first cutting edge 12, and the third cutting edge 16 and the fourth cutting edge 18 may extend obliquely in the same direction as the first cutting edge 12.

Further, the first, third and fourth cutting edges 12, 16 and 18 may extend obliquely to the first direction E1, and the second cutting edge 14 may extend obliquely to the second direction E2. Therefore, the cutting load of the entire cutting portion 1 can be equally distributed, and the cutting quality can be improved.

In addition, the angle θ1 formed by the first cutting edge 12 and the center line C1 passing through the center of the through hole a may be the same as or greater than the angle θ3 formed by the third cutting edge 16 and the center line C1. The center line C1 may be a straight line in a direction parallel to the extending direction of the cutting portion 1. Therefore, the entire cutting load of the cutting portion 1 can be more evenly distributed.

The angle θ3 formed by the third cutting edge 16 and the center line C1 may be formed larger than the angle θ4 formed by the fourth cutting edge 18 and the center line C1, and the cutting load of the entire cutting portion 1 may be more uniformly distributed.

Specifically, the angle θ1 formed by the first cutting edge 12 and the center line C1 passing through the center of the through hole a is 5 to 10 degrees, the angle θ3 formed by the third cutting edge 16 and the center line C1 is 4 to 7 degrees, and the angle θ4 formed by the fourth cutting edge 18 and the center line C1 is 0 to 3 degrees.

Therefore, the cutting load of the entire cutting portion 1 can be more evenly distributed, the overall wear of the cutting portion 1 can be minimized, and the cutting quality can be effectively ensured.

More specifically, the angle θ1 formed by the first cutting edge 12 and the center line C1 passing through the center of the through hole a is 6 to 9 degrees, the angle θ3 formed by the third cutting edge 16 and the center line C1 is 5 to 6 degrees, and the angle θ4 formed by the fourth cutting edge 18 and the center line C1 is 1 to 2 degrees.

Therefore, the cutting load of the entire cutting portion 1 can be more evenly distributed, the overall wear of the cutting portion 1 can be minimized, and the cutting quality can be effectively ensured.

In addition, the difference between the angle θ1 formed by the first cutting edge 12 and the center line C1 and the angle θ2 formed by the second cutting edge 14 and the center line C1 may be within 3 degrees. Therefore, the cutting load can be more effectively distributed between the first cutting edge 12 and the second cutting edge, and the cutting quality can be effectively ensured.

Specifically, the angle θ2 formed by the second cutting edge 14 and the center line C1 may be 5 degrees to 10 degrees. Therefore, a balanced load distribution with the first cutting edge 12 can be ensured.

Further specifically, the angle θ2 formed by the second cutting edge 14 and the center line C1 may be 6 degrees to 9 degrees, and therefore, even load distribution with the first cutting edge 12 may be ensured, and cutting quality may be improved.

The angle θ1 formed by the first cutting edge 12 and the centerline C1 may be selectively greater or less than the angle θ2 formed by the second cutting edge 14 and the centerline C1. Further, the angle θ1 formed by the first cutting edge 12 and the center line C1 may be larger or smaller than the angle θ2 formed by the second cutting edge 14 and the center line C1, in terms of the kind of the material to be cut, the rotational speed of the bit body D, and the like.

Fig. 6 is a side view of an insert according to an embodiment of the present invention. According to fig. 6, the side surface 3 of an embodiment of the invention may comprise a clearance surface 31 and a protrusion 33.

The clearance surface 31 may extend from the lower surface 7 toward the cutting portion 1. The clearance surface 31 has a larger cross section than the lower surface 7 on the upper surface 5, and thus can extend obliquely in a direction away from the center of the through hole a.

The projection 33 extends from the clearance surface 31 to the upper surface 5 and may project further outward than the clearance surface 31. Further, the convex portion 33 may extend to contact the cutting portion 1 to protrude further outward than the clearance surface 31 to more effectively distribute the load applied to the cutting portion 1. Therefore, the degree of wear of the cutting portion 1 can be minimized.

In addition, the height H1 from the lower face 7 to the clearance face 31 may be set to 0.6 to 0.8 of the height H2 from the lower face 7 to the cutting portion 1. The extent to which the projections 33 are formed is thus optimised to ensure security of the fastening when assembled on the drill.

Specifically, the height H1 from the lower face 7 to the clearance face 31 is 0.65 to 0.75 that can be set to the height H2 from the lower face 7 to the cutting portion 1. Thus, the degree of formation of the projection 33 is further optimized, thereby further ensuring the safety of the fastening at the time of assembly on the drill.

Fig. 7 is a bottom view of an insert according to an embodiment of the present invention. Referring to fig. 6 and 7, the clearance surface 31 according to an embodiment of the present invention may include an angular clearance surface 311, a first clearance surface 313, and a second clearance surface 315.

The corner clearance surface 311 may include a first corner clearance surface 3111 extending toward the first corner edge 111 and a second corner clearance surface 3113 extending toward the second corner edge 113. The first clearance surface 313 is connected to the first corner clearance surface 3111 and extends toward the first cutting edge 12, the first convex edge 13, the second cutting edge 14, and the concave edge 15.

The second clearance surface 315 is connected to the second corner clearance surface 3113 and may extend toward the concave edge 15, the third cutting edge 16, the second convex edge 17, and the fourth cutting edge 18. The second clearance surface 315 may be connected to the first clearance surface 313 at the center of the cutting portion 1.

The angle α formed by the first clearance surface 313 and the second clearance surface 315 may be set to an obtuse angle. Thus, the overall structural safety of the insert I may be increased. Moreover, the overall shape of the lower face 7 is octagonal, so that structural equilibrium can be ensured.

Specifically, the angle α formed by the first clearance surface 313 and the second clearance surface 315 may form 150 degrees to 180 degrees, and thus the overall structural safety of the insert I may be further improved.

Further specifically, the angle α formed by the first clearance surface 313 and the second clearance surface 315 may form 160 degrees to 170 degrees, and thus the overall structural safety of the insert I may be further improved.

Fig. 8 is a schematic view showing a slot portion of a bit body according to an embodiment of the present invention. Specifically, fig. 8a shows the inner groove portion, and fig. 8b shows the outer groove portion.

According to fig. 8, a bit body D according to an embodiment of the present invention may incorporate the insert I described above. The bit body D may include a body portion 8 and a slot portion 9. As described above, the main body 8 is formed such that at least a part thereof extends in a spiral shape, and by rotating, boring, drilling, or cutting of a workpiece can be facilitated.

The slot 9 may include a bottom surface 91 and a wall surface 93. The bottom surface 91 may be contacted and supported by the lower surface 7. Specifically, the bottom surface 91 may have a shape corresponding to the lower surface 7, and may be formed flat so that the lower surface 7 is seated.

The wall 93 is connected to the bottom 91 so that the side 3 can be contacted. Specifically, the wall surface 93 may include a first wall portion 931, a second wall portion 933, and a third wall portion 935. The first wall portion 931 may be connected to the bottom surface 91.

The second wall portion 933 is obliquely extended from the first wall portion 931 away from the bottom surface 91. The third wall portion 935 may extend concavely inward from the second wall portion 933. The second wall portion 933 is supported in contact with the gap surface 31.

Therefore, the second wall portion 933 can provide a supporting force to the entire insert I by the support of the clearance surface 31, and the first wall portion 931 and the third wall portion 935 can restrict the range of the insert I even if it is shaken by external vibration, thereby improving fastening safety.

In addition, as described above, the cutting portion 1 may include the first cutting portion 1a, the second cutting portion 1b, the third cutting portion 1c, and the fourth cutting portion 1d, and the wall surface 93 may include the first wall surface 93a and the second wall surface 93b.

The first wall surface 93a is arranged at a position corresponding to the first cut portion 1a such that the second wall portion 933 of the first wall surface 93a can support the clearance surface 31 of the first cut portion 1a, and the second wall surface 93b is arranged at a position corresponding to the second cut portion 1b such that the second wall portion 933 of the second wall surface 93b can support the clearance surface 31 of the second cut portion 1 b.

The groove 9 may include an inner groove 9a disposed opposite to the inner side and an outer groove 9b disposed opposite to the outer side, and the wall surface 93 of the outer groove 9b may include a first wall surface 93a and a second wall surface 93b.

The inner groove 9a may include a third wall surface 93c in addition to the first wall surface 93a and the second wall surface 93b, and the second wall portion 933 of the third wall surface 93c may support a clearance surface of the third cutting portion 1 c. This may be due to the difference in the positions where the inner groove 9a and the outer groove 9b are formed.

Fig. 9 is a schematic view showing angles formed by the second wall portions arranged at mutually different positions. According to fig. 9, a plurality of second wall portions 933 according to an embodiment of the invention may form a predetermined angle.

Further, the angle β formed by the second wall portion 933 disposed on the first wall surface 93a and the second wall portion 933 disposed on the second wall surface 93b may form an acute angle. Therefore, by improving the fastening stability, the movement of the insert cutting insert during machining can be minimized, thereby improving the workability.

Specifically, the second wall portion 933 disposed on the first wall surface 93a and the second wall portion 933 disposed on the second wall surface 93b form an angle β of 70 degrees to 90 degrees, and thus fastening stability is further improved, so that the movement of the insert cutting insert at the time of machining is minimized, and thus workability is further improved.

Further specifically, the second wall portion 933 disposed on the first wall surface 93a and the second wall portion 933 disposed on the second wall surface 93b form an angle β of 75 degrees to 85 degrees, and fastening stability can be further improved, so that the movement of the insert cutting insert during machining is minimized, thereby further improving workability. The inner groove 9a is also provided in the same manner as the second wall 933 provided on the second wall 93b and the second wall 933 provided on the third wall 93 c.

Fig. 10 is a schematic view showing rotation of the inside and outside insert cutting blades according to an embodiment of the present invention. According to fig. 10, the insert according to an embodiment of the present invention may have an optimal rotation trajectory.

Further, the insert cutting insert I may include an inner insert IN fitted on the inner groove portion 9a and an outer insert IO fitted on the outer groove portion 9b, and may have a rotation locus as shown IN fig. 10.

Specifically, the insert I functions by allowing the cutting load applied to the tool during cutting to be uniformly distributed to each of the partial edges while intersecting the left and right directions.

By the curved cutting edges from the first cutting edge 12 to the fourth cutting edge 18, the lengths of the outer insert IO and the inner insert IN that contact the workpiece become very uniform, and the cutting loads are balanced out by intersecting each other IN the outer and center directions of the drill holder, and vibrations are suppressed, so that machining can be performed satisfactorily.

In addition, the cutting edge can realize balanced normal abrasion integrally, avoid the phenomenon that only a certain part is abraded, and prevent the problems such as burst damage, thereby prolonging the service life of the tool.

Fig. 11 is a schematic view showing the wear degrees of a conventional cutting insert and an insert cutting insert according to an embodiment of the present invention, specifically, fig. 11a is a schematic view showing a conventional inner insert, fig. 11b is a schematic view showing a conventional outer insert, fig. 11C is a schematic view showing an inner insert according to an embodiment of the present invention, and fig. 11d is a schematic view showing an outer insert according to an embodiment of the present invention.

As can be seen from fig. 11, the insert I according to an embodiment of the present invention has less wear phenomenon than the conventional insert I'. Further, the insert I according to an embodiment of the present invention may improve the safety of fastening the bit body D, minimize the movement of the cutting groove during machining, and thus minimize the degree of wear.

And the insert I is an optimal state in which the first corner edge 111, the first cutting edge 12, the first convex edge 13, the second cutting edge 14, the concave edge 15, the third cutting edge 16, the second convex edge 17, the fourth cutting edge 18, and the second corner edge 113 are connected, the cutting load per unit area is minimized, and thus, the wear is minimized.

The above representative embodiments are only for illustrating the technical aspects of the present invention, not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may be modified or replaced with other technical solutions, which do not deviate from the scope of the technical solutions described in the embodiments of the present invention.

Claims (20)

1. An embedded cutting insert, characterized in that,

Comprising the following steps: the following; an upper surface provided separately from the lower surface; a side connecting the upper face and the lower face; a through hole formed through the center of the upper surface; a cutting portion formed along an outer periphery of the upper surface and cutting a material to be cut; the cutting portion includes: a corner edge comprising a first corner edge disposed at one end and a second corner edge disposed at the other end; a first cutting edge extending obliquely from the first corner edge to the second corner edge; a first convex edge extending from the first cutting edge toward the second corner edge and protruding in a direction away from the through hole; a second cutting edge extending obliquely from the first convex edge toward the second corner edge; a concave edge extending from the second cutting edge toward the second corner edge and recessed in a direction approaching the through hole; a third cutting edge extending obliquely from the concave edge toward the second corner edge; a second convex edge extending from the third cutting edge toward the second corner edge and protruding away from the through hole; and a fourth cutting edge extending obliquely from the second convex edge toward the second corner edge.

2. The insert according to claim 1, wherein,

The first cutting edge extends obliquely from the direction of the first corner edge away from the through hole;

the second cutting edge extends obliquely in a direction opposite to the first cutting edge;

the third cutting edge and the fourth cutting edge extend obliquely in the same direction as the first cutting edge.

3. The insert according to claim 2, wherein,

The angle (theta 1) formed by the first cutting edge and a center line (C1) passing through the center of the through hole is the same as or greater than the angle (theta 3) formed by the third cutting edge and the center line (C1).

4. The insert as claimed in claim 3, wherein,

The angle (theta 3) formed by the third cutting edge and the center line (C1) is formed larger than the angle (theta 4) formed by the fourth cutting edge and the center line (C1).

5. The insert according to claim 4, wherein,

The angle (theta 1) formed by the first cutting edge and the central line (C1) is 5-10 degrees, the angle (theta 3) formed by the third cutting edge and the central line (C1) is 4-7 degrees, and the angle (theta 4) formed by the fourth cutting edge and the central line (C1) is 0-3 degrees.

6. The insert according to claim 5, wherein,

The angle (theta 1) formed by the first cutting edge and the central line (C1) is 6-9 degrees, the angle (theta 3) formed by the third cutting edge and the central line (C1) is 5-6 degrees, and the angle (theta 4) formed by the fourth cutting edge and the central line (C1) is 1-2 degrees.

7. The insert according to claim 5, wherein,

An angle (theta 1) formed by the first cutting edge and the center line (C1) and an angle (theta 2) formed by the second cutting edge and the center line (C1) are different within 3 degrees.

8. The insert according to claim 7, wherein,

The second cutting edge forms an angle (theta 2) with the center line (C1) of 5 degrees to 10 degrees.

9. The insert according to claim 7, wherein,

An angle (θ1) formed by the first cutting edge and the center line (C1) is formed larger than an angle (θ2) formed by the second cutting edge and the center line (C1).

10. The insert according to claim 7, wherein,

An angle (θ1) formed by the first cutting edge and the center line (C1) is formed smaller than an angle (θ2) formed by the second cutting edge and the center line (C1).

11. The insert according to claim 8, wherein,

The extension length of the second convex edge is formed shorter than the extension length of the first convex edge.

12. The insert according to claim 1, wherein,

The side surface includes:

a clearance surface extending from the lower face toward the cutting portion;

And a projection extending from the clearance surface toward the upper surface and projecting outward from the clearance surface.

13. The insert according to claim 12, wherein,

The height (H1) from the lower face to the clearance face is 0.6 to 0.8 of the height (H2) from the lower face to the cutting portion.

14. The insert according to claim 12, wherein,

The clearance surface includes: an angular clearance surface comprising a first angular clearance surface extending toward the first angular edge and a second angular clearance surface extending toward the second angular edge; a first clearance surface connected to the first angular clearance surface and extending toward the first cutting edge, the first convex edge, the second cutting edge, and the concave edge; and a second clearance surface connected to the second angular clearance surface and extending toward the concave edge, the third cutting edge, the second convex edge, and the fourth cutting edge.

15. The insert according to claim 14, wherein,

An angle (α) formed by the first clearance surface and the second clearance surface is formed as an obtuse angle.

16. The insert according to claim 15, wherein,

The first clearance surface and the second clearance surface form an angle (alpha) of 150 degrees to 180 degrees.

17. A drill bit body is characterized in that,

The bit body to which the insert of claim 16 is bonded, comprising:

A body portion having at least a portion extending in a spiral shape; a groove portion disposed at an end of the body portion, and to which the insert cutting insert is coupled; the groove portion includes: a bottom surface of the lower contact; a wall surface connected to the bottom surface and contacting the side surface; the wall surface includes: a first wall portion connected to the bottom surface; a second wall portion extending obliquely while the first wall portion is away from the bottom surface; a third wall portion recessed inward from the second wall portion; the second wall portion is supported in contact with the clearance surface.

18. The bit body of claim 17, wherein the bit body comprises a plurality of blades,

The cutting portion includes: a first cutting portion; a second cutting portion connected to the first cutting portion; a third cutting portion connected to the second cutting portion; a fourth cutting portion connected to the third cutting portion and the first cutting portion; the wall surface includes: a first wall surface arranged at a position corresponding to the first cutting portion; a second wall surface disposed at a position corresponding to the second cutting portion.

19. The bit body of claim 18, wherein the bit body comprises,

The angle (β) formed by the second wall portion arranged at the first wall surface and the second wall portion arranged at the second wall surface may form an acute angle.

20. The bit body of claim 19, wherein the bit body comprises a plurality of blades,

An angle (beta) formed by the second wall portion arranged on the first wall surface and the second wall portion arranged on the second wall surface is 70 degrees to 90 degrees.