WO2011159119A2

WO2011159119A2 - Cutting insert and tool holder for mounting the cutting insert

Info

Publication number: WO2011159119A2
Application number: PCT/KR2011/004430
Authority: WO
Inventors: Kedar Bhagath
Original assignee: Taegutec Ltd.
Priority date: 2010-06-17
Filing date: 2011-06-16
Publication date: 2011-12-22
Also published as: KR20110137667A; KR101175454B1; WO2011159119A3

Abstract

The cutting insert 1 of the present invention comprises a body portion 10 placed in the center of the cutting insert 1 and the first cutting portion 20 and the second cutting portion 30, which are formed in each end of the body portion 10 and have the substantially same configuration with each other. The cutting insert 1 has one recess 40 on the intersecting edge of a first bottom clamping surface 13 and a second bottom clamping surface 14, which allows the cutting insert 1 to be mounted in a tool holder 100 in an accurate lateral position when the cutting insert 1 is mounted in the tool holder 100.

Description

CUTTING INSERT AND TOOL HOLDER FOR MOUNTING THE CUTTING INSERT

The present invention relates to a cutting insert and a tool holder for mounting the cutting insert. More particularly, the present invention relates to a cutting insert, which has two cutting edges with substantially same configuration and is particularly suitable for a deep groove machining, and a tool holder for mounting the cutting insert.

A cutting insert for groove machining is well known in the field of mechanical machining. A conventional cutting insert for groove machining is typically configured such that a cutting edge has the largest width in the cutting insert.

Fig. 13 shows a conventional cutting insert 200 for groove machining with two cutting edges, which performs groove machining. In the conventional cutting insert 200 for groove machining shown in Fig. 13, two cutting edges are substantially in a same plane, and thus, this conventional cutting insert 200 cannot make a groove with a deeper depth than the length of the cutting insert. If the cutting insert 200 shown in Fig. 13 is used to make a groove having a deeper depth than the length of the cutting insert 200, then a non-working cutting edge 202 comes into contact with a grooved surface 220 and the grooved surface 220 or the non-working cutting edge 202 is damaged.

To overcome this problem, the cutting insert with one cutting edge has been used to make a groove having a deeper depth than the length of the cutting insert. This cutting insert with one cutting edge is conventionally used with a tool holder having a narrower width than that of the cutting edge. Thus, the cutting insert can freely move within the groove formed by the cutting edge and make a groove having a deeper depth than the cutting edge. However, such a cutting insert with one cutting edge is not preferable in terms of cost-effectiveness as compared to the cutting insert with two cutting edges.

Fig. 14 shows a conventional method of mounting a cutting insert 300 in a tool holder 310. The conventional tool holder 310 shown in Fig. 14 secures the cutting insert 300 in the tool holder 310 by thread-engaging a separate top support member 320 in the tool holder 310. Thus, in such a conventional tool holder 310, when the cutting insert 300 is replaced, the top support member 320 should be unthreaded and removed from the tool holder 310, which is troublesome and time consuming. Further, the conventional tool holder 310 shown in Fig. 14 requires a mounting area 330 for mounting the top support member 320. As a result, the tool holder 310 should be formed more thickly, and a groove depth to be machined is limited by the configuration of the tool holder 310.

The object of the present invention is to solve the aforementioned problems of conventional cutting inserts and provide a cutting insert and a tool holder, which is capable of performing deep groove machining without any limitation by the configuration of the cutting insert and the tool holder.

The present invention provides a cutting insert 1, which has two cutting edges and is particularly suitable for deep groove machining. The cutting insert 1 according to the present invention comprises a body portion 10 placed in the center of the cutting insert 1, and a first cutting portion 20 and the second cutting portion 30 that are formed in each end of the body portion 10 and have the substantially same configuration. The first cutting portion 20 and the second cutting portion 30 are placed in different planes and are slanted at an angle with each other.

The body portion 10 comprises a first top clamping surface 11, a second top clamping surface 12 adjacent to the first top clamping surface 11, a first bottom clamping surface 13 opposite to the first top clamping surface 11, and a second bottom clamping surface 14 opposite to the second top clamping surface 12. The first top clamping surface 11 has a receiving groove 15 and the second top surface 12 has a receiving groove 16.

The first cutting portion 20 comprises a first front surface 21, a first top surface 22 extending from the first top clamping surface 11 of the body portion 10 to the first front surface 21, and two

side walls

23, 24 extending from the second top clamping surface 12 and the second bottom clamping surface 14 of the body portion 10 to the first front surface 21. A first front cutting edge 25 is formed at the intersection of the first front surface 21 and the first top surface 22. The first side cutting edges 26 are formed at the intersection of the first top surface 22 and the two

side walls

23, 24 of the first cutting portion 20.

The second cutting portion 30 comprises a second front surface 31, a second top surface 32 extending from the second top clamping surface 12 of the body portion 10 to the second frond surface 31, and two

side walls

33, 34 extending from the first top clamping surface 11 and the first bottom clamping surface 13 of the body portion 10 to the second front surface 31. A second front cutting edge 35 is formed at the intersection of the second front surface 31 and the second top surface 32. The second side cutting edges 36 are formed at the intersection of the second top surface 32 and the two

side walls

33, 34 of the second cutting portion 30.

In the cutting insert 1 according to one embodiment of the present invention, the second front cutting edge 35 is preferably slanted at an angle of 65 to 125 degrees with respect to the first front cutting edge 25. The above slant of the first front cutting edge 25 and the second front cutting edge 35 provides a space between the grooved surfaces of the work-piece and non-working cutting edge, which does not contribute to the machining of the work-piece, to prevent the damage of the grooved surface or the non-working cutting edge. In a preferred embodiment of the present invention, the second front cutting edge 35 is slanted at an angle of 90 degrees with respect to the first front cutting insert 25. When the first front cutting edge 25 and the second front cutting edge 35 are slanted at an angle of 90 degrees, the non-working cutting edge and the grooved surface can have the maximum space therebetween. Further, the cutting insert 1 according to the present invention is configured such that the intersection "A" of the first front cutting edge 25 and the second front cutting edge 35 is offset from the center "C" of the cutting edge when viewed from the front of the first front cutting edge 25 or the second front cutting edge 35. Due to such offset, the first cutting portion 20 and the second cutting portion 30 of the cutting insert 1 may be formed more thickly. Further, the cutting insert 1 according to the present invention is preferably configured such that the distance from the intersection "A" of the first front cutting edge 25 and the second front cutting edge 35 to the end of the first front cutting edge 25 is identical to the distance from the intersection "A" of the first front cutting edge 25 and the second front cutting edge 35 to the second front cutting edge 35. In such a case, the first front cutting edge 25 and the second front cutting edge 35 can be interchangeably mounted in a machining position.

Further, the first side cutting edge 26 and the second side cutting edge 36 of the cutting insert 1 according to the present invention are respectively formed to be slanted with respect to the first front cutting edge 25 and the second front cutting edge 35 with an acute angle. As such, the side cutting edges are formed to be slanted into width of the front cutting edge, which results in that the cutting insert 1 according to the present invention can provide a space between the side cutting edge and the grooved surfaces to prevent the grooved surfaces from being damaged.

The cutting insert 1 according to the present invention has a recess 40 for receiving a stopper 125 formed in the tool holder 100 on the intersecting edge of the first bottom clamping surface 13 and the second bottom clamping surface 14 (see Fig. 2). When the cutting insert 1 is mounted in the tool holder 100, the stopper 125 of the tool holder 100 is received in the recess 40, and the cutting insert 1 can be placed in an acute position. Further, the cutting insert 1 according to the present invention is preferably provided with only one recess 40 on the intersecting edge of the first bottom clamping surface 13 and the second bottom clamping surface 14. One side 40a of the recess 40 comes into contact with the stopper 125 of the tool holder 100 when the first cutting portion 20 is placed in the machining position. Another side 40b of the recess 40 comes into contact with the stopper 125 of the tool holder 100 when the second cutting portion 30 is placed in the machining position (see Figs. 2 and 10). As such, the cutting insert 1 according to the present invention can have only one recess 40 for receiving the stopper 125 of the tool holder 100, and it can prevent a weakening of the strength 1 due to the reduction of the thickness of the cutting insert 1.

The cutting insert 1 according to one embodiment of the present invention is configured such that the contacting line or surface of the receiving groove 15 formed in the first top clamping surface 11 and the top support surface 110 of the tool holder 100 is formed in a diagonal direction when viewed from above the first top clamping surface 11. That is, the receiving groove 15 formed in the first top clamping surface 11 of the cutting insert 1 engages with the top support surface 110 of the tool holder 100 such that the clamping force toward the stopper 125 of the tool holder 100 is generated (see Fig. 10). Similarly, the cutting insert 1 according to one embodiment of the present invention is configured such that the contacting line or surface of the receiving groove 16 formed in the second top clamping surface 12 and the top support face 110 of the tool holder 100 is formed in a diagonal direction when viewed from above the second top clamping surface 12. As such, the cutting insert 1 according to the present invention is configured such that the top support surface 110 of the tool holder 100 comes into contact with the receiving groove 15 formed in the first top clamping surface 11 and the receiving groove 16 formed in the second top clamping surface 12 in a diagonal direction, which allows to provide the longitudinal and lateral clamping forces to the cutting insert 1 and reliably retain the cutting insert 1 in the tool holder 100 during machining operations.

In the cutting insert 1 according to another embodiment of the present invention, the first bottom clamping surface 13 comprises an inclined surface 13a slanted with respect to the first front cutting edge 25 with an acute angle and the second bottom clamping surface 14 comprises an inclined surfaces 14a slanted with respect to the second front cutting edge 35 with an acute angle. Due to such inclined surfaces 13a, 14a, the cutting insert 1 can provide the longitudinal and lateral clamping forces to the cutting insert 1 when the cutting insert 1 is mounted in the tool holder 100, and reliably retain the cutting insert 1 in the tool holder 100 during machining operations.

The present invention provides the tool holder 100 for mounting the cutting insert 1. The tool holder 100 according to one embodiment of the present invention comprises a pocket 130 for mounting the cutting insert 1.

The pocket 130 comprises a top support surface 110 where the first top clamping surface 11 or the second top clamping surface 12 of the cutting insert 1 is mounted, a bottom support surface 120 where the first bottom clamping surface 13 or the second bottom clamping surface 14 of the cutting insert 1 is mounted, and a stopper 125 configured to protrude upwardly from the bottom support surface 120 to be received in the recess 40 of the cutting insert 1.

According to one embodiment of the present invention, the top support surface 110 of the tool holder 100 is configured such that the contacting line or surface of the receiving

grooves

15, 16 of the cutting insert 1 and the top support surface 110 of the tool holder 100 is formed in a diagonal direction when viewed from above the top support surface 110 of the tool holder 100. Due to such configuration, the cutting insert 1 can receive the longitudinal and lateral clamping forces when the cutting insert 1 is mounted in the tool holder 100 and thus can be reliably retained in the tool holder 100 during machining operations.

According to another embodiment of the present invention, the bottom support surface 120 of the tool holder 100 is slanted with the same angle to the angle between the first and second

bottom clamping surfaces

13, 14 and the first and second

front cutting edges

25, 35. Due to such configuration, the cutting insert 1 can receive the longitudinal and lateral clamping forces when mounted in the tool holder 100, and thus can be reliably retained in the tool holder 100 during machining operations.

The

receiving grooves

15, 16 of the cutting insert 1 according to the present invention are slanted when viewed from the front of the cutting insert 1 (see Fig. 10) and are parallel to the first front cutting edge 25 or the second front cutting edge 35 when viewed from above the cutting insert 1 (see Fig. 6). Due to such configuration, the cutting insert 1 can be slidably inserted into the pocket 130 of the tool holder 100 from the side of the tool holder 100. Further, one side surface of the recess 40 of the cutting insert 1 may come into contact with the stopper 125 of the tool holder 100 to provide lateral positioning of the cutting insert 1. Also, the inclined surface formed either in the top clamping surface or the bottom clamping surface of the cutting insert 1 provides the clamping force toward the stopper 125 of the tool holder 100 and the clamping force toward the back of the cutting insert 1 to secure the cutting insert 1 in the pocket 130 of the tool holder 100 when the cutting insert 1 is mounted in the tool holder 100.

Preferably, the tool holder 100 according to one embodiment of the present invention has a width smaller than that of the cutting insert 1. Such configuration provides a space between the tool holder 100 and the grooved surfaces. Thus, the cutting insert 1 can make a deep groove without any limitation by the configuration of the cutting insert 1 and the tool holder 100.

As described above, the cutting insert according to the present invention is configured such that the two cutting edges are formed in different planes and are slanted at an angle of 65 to 125 degrees with each other. Thus, the cutting insert can provide a space between the non-working cutting edge and the grooved surfaces machined by the working cutting edge. As such, the cutting insert can make a deep groove without any limitation by the configuration of the cutting insert.

Further, the cutting insert according to the present invention has the recess on the intersecting edge of the first bottom clamping surface and the second bottom clamping surface. Thus, the stopper of the tool holder can be received in the recess and the cutting insert can be mounted in the tool holder at an accurate position. Furthermore, the cutting insert according to the present invention is preferably provided with only one recess for receiving the stopper of the tool holder. As such, it is prevented that the thickness of the cutting insert is reduced and the strength of the cutting insert is weakened.

The tool holder according to the present invention may be configured such that the top support surface and the bottom support surface are integrally formed. If the top support surface and the bottom support surface are integrally formed, then it is not necessary to form a separate clamping area for securing a top support surface in the tool holder, which results in that the cutting insert can make a deep groove without any limitation by the configuration of the tool holder. Further, the above configuration of the tool holder allows the cutting insert to be easily replaced by expanding the space between the top support surface and the bottom support surface with tools such as a wrench.

The receiving grooves of the cutting insert according to the present invention are slanted when viewed from the front of the cutting insert (see Fig. 10) and are parallel to the first front cutting edge or the second front cutting edge when viewed from above the cutting insert (see Fig. 6). Thus, the cutting insert can be slidably inserted into the pocket of the tool holder from the side of the tool holder. One surface of the recess formed in the cutting insert can come into contact with the stopper of the tool holder to provide lateral positioning of the cutting insert. Further, the inclined surface formed either in the top clamping surface or the bottom clamping surface of the cutting insert provides the clamping force toward the stopper of the tool holder and the clamping force toward the back of the cutting insert to reliably secure the cutting insert in the pocket of the tool holder when the cutting insert is mounted in the tool holder.

Further, the tool holder according to the present invention has a width smaller than that of the cutting insert, which may prevent the groove depth from being limited by the configuration of the tool holder.

Fig. 1 is a perspective view of the cutting insert according to one embodiment of the present invention.

Fig. 2 is another perspective view of the cutting insert according to one embodiment of the present invention.

Fig. 3 is a front view of the cutting insert according to one embodiment of the present invention and shows an embodiment wherein the second front cutting edge is slanted at an angle of 90 degrees with respect to the first front cutting edge.

Fig. 4 is a front view of the cutting insert according to one embodiment of the present invention and shows an embodiment wherein the second front cutting edge is slanted at an angle of 65 degrees with respect to the first front cutting edge.

Fig. 5 is a front view of the cutting insert according to one embodiment of the present invention and shows an embodiment wherein the second front cutting edge is slanted at an angle of 125 degrees with respect to the first front cutting edge.

Fig. 6 is a top plan view of the cutting insert shown in Fig. 1.

Fig. 7 is a perspective view of the tool holder according to one embodiment of the present invention.

Fig. 8 shows that the cutting insert according to one embodiment of the present invention is mounted in the tool holder.

Fig. 9 shows that the cutting insert according to one embodiment of the present invention is mounted in the tool holder.

Fig. 10 is a cross-section view taken along line A-A of Fig. 9.

Fig. 11 shows that the cutting insert according to one embodiment of the present invention is mounted in the tool holder.

Fig. 12 is a cross-section view taken along line B-B of Fig. 11.

Fig. 13 shows that a conventional cutting insert for groove machining performs groove cutting in a workpiece.

Fig. 14 shows that a conventional cutting insert is mounted in a tool holder.

The cutting insert according to the present invention and the tool holder for mounting the cutting insert will be described hereinafter in detail with reference to the accompanying drawings.

Fig. 1 is a perspective view of the cutting insert 1 according to the present invention. The cutting insert 1 comprises a body portion 10 placed in the center of the cutting insert 1, as well as a first cutting portion 20 and a second cutting portion 30 that are formed in each end of the body portion 10 and have a substantially same configuration to each other. The first cutting portion 20 and the second cutting portion 30 are placed in different planes and are slanted at an angle with each other.

The body portion 10 comprises a first top clamping surface 11, a second top clamping surface 12 adjacent to the first top clamping surface 11, a first bottom clamping surface 13 opposite to the first top clamping surface 11, and a second bottom clamping surface 14 opposite to the second top clamping surface 12. The first top clamping surface 11 has a receiving groove 15 and the second top surface 12 has a receiving groove 16. When the cutting insert 1 is mounted in a tool holder 100, the receiving

grooves

15, 16 receive a top support surface 110 of the tool holder 100. The cutting insert 1 has a recess 40 for receiving a stopper 125 of the tool holder 100 on the intersecting edge of the first bottom clamping surface 13 and the second bottom clamping surface 14 of the body portion 10.

The first cutting portion 20 extending from one end of the body portion 10 comprises a first front surface 21, a first top surface 22 extending from the first top clamping surface 11 of the body portion 10 to the first front surface 21, and two

side walls

23, 24 extending from the second top clamping surface 12 and the second bottom clamping surface 14 of the body portion 10 to the first front surface 21. A first front cutting edge 25 is formed at the intersection of the first front surface 21 and the first top surface 22 of the first cutting portion 20, while the first side cutting edges 26 are formed at the intersection of the first top surface 22 and two

side walls

23, 24 of the first cutting portion 20.

The second cutting portion 30 extending from the other end of the body portion 10 comprises a second front surface 31, a second top surface 32 extending from the second top clamping surface 21 of the body portion 10 to the second frond surface 31, and two

side walls

33, 34 extending from the first top clamping surface 11 and the first bottom clamping surface 13 of the body portion 10 to the second front surface 31. A second front cutting edge 35 is formed at the intersection of the second front surface 31 and the second top surface 32 of the second cutting portion 30, while second side cutting edges 36 are formed at the intersection of the second top surface 32 and two

side walls

33, 34 of the second cutting portion 30.

Figs. 1 to 6 show configurations of the first front cutting edge 25, the second front cutting edge 35, the first side cutting edge 26 and the second side cutting edge 36. As shown in Fig. 3, the first front cutting edge 25 of the cutting insert 1 is not parallel to the second front cutting edge 35. The second front cutting edge 35 of the second cutting portion 30 is slanted at an angle with respect to the first front cutting edge 25 of the first cutting portion 20. The first front cutting edge 25 and the second front cutting edge 35 intersect at a point "A" when viewed from the first front surface 21 or the second front surface 31 (see Fig. 3). The first front cutting edge 25 and the second front cutting edge 35 of the cutting insert 1 are preferably slanted at an angle of 65 to 125 degrees to each other. As shown in Fig. 4, if the angle between the first front cutting edge 25 and the second front cutting edge 35 is less than 65 degrees, then an end portion of the second front cutting edge 35 may protrude over the width "W" of the first front cutting edge 25. Thus, if this cutting insert 1 is used to make a deep grove that is deeper than the length of the cutting insert, then the second front cutting edge 35 of the cutting insert 1, which is a non-working cutting edge, may contact with the grooved surface of the workpiece to damage the grooved surface or the second front cutting edge 35. On the contrast, if the angle between the first front cutting edge 25 and the second front cutting edge 35 is more than 125 degrees, then another end portion of the second front cutting edge 35 may protrude over the width "W" of the first front cutting edge 25. Thus, this cutting insert cannot be used to make a deep groove, which is deeper than the length of the cutting insert, similar to the cutting insert that the angle between the first front cutting edge 25 and the second front cutting edge 35 is less than 65 degrees. To overcome the above problem, the cutting insert 1 according to the present invention is configured such that the first front cutting edge 25 and the second front cutting edge 35 are slanted at an angle of 65 and 125 degrees to each other, and the non-working cutting edge and the grooved surfaces can have a space therebetween. Thus, the cutting insert 1 according to the present invention can be used to make a deep groove, which is deeper than the length of the cutting insert 1. Further, as shown in Fig. 3, the intersection "A" of the first front cutting edge 25 and the second front cutting edge 35 of the cutting insert 1 is preferably offset from the center "C" of the front cutting edges (see Figs. 3 to 5). Thus, the first cutting portion 20 and the second cutting portion 30 can be formed with the same thickness. Also, the cutting insert 1 of the present invention is preferably configured such that the distance from the intersection "A" of the first front cutting edge 25 and the second front cutting edge 35 to the end of the first front cutting edge 25 is same as the distance from the intersection "A" of the first front cutting edge 25 and the second front cutting edge 35 to the second front cutting edge 35. In such a case, the first front cutting edge 25 and the second front cutting edge 35 can be interchangeably mounted in the tool holder.

Fig. 6 is a top plan view of the cutting insert 1 according to the present invention. The first side cutting edge 26 of the first cutting portion 20 is slanted with respect to the first front cutting edge 25 with an acute angle. Thus, the first side cutting edge 26 is slanted into the width "W" of the first front cutting edge 25, and it is prevented that the first side cutting edge 26 contacts with and damages the grooved surface. Similarly, the second side cutting edge 36 of the second cutting portion 30 is also slanted with respect to the second front cutting edge 35 with an acute angle.

Further, the body portion 10 of the cutting insert 1 is formed with a constant width along the length of the cutting insert 1. Thus, the body portion 10, which acts as a clamping portion for mounting the cutting insert 1 in the tool holder, can have an increased strength.

Fig. 7 shows the tool holder 100 for mounting the cutting insert 1, while Fig. 8 shows the configuration wherein the cutting insert 1 is mounted in the tool holder 100 shown in Fig. 7. As shown in Fig. 7, the tool holder 100 comprises a pocket 130 for receiving the cutting insert 1. The pocket 130 comprises: a top support surface 110, which contacts with the first top clamping surface 11 or the second top clamping surface 12 of the cutting insert 1; and a bottom support surface 120, which contacts with the first bottom clamping surface 13 or the second bottom clamping surface 14 of the cutting insert 1, wherein the top support surface 110 and the bottom support surface 120 of the tool holder 100 may be integrally formed. The top support surface 110 and the connecting area of the top supporting surface 110 and the bottom support surface 120 have holes 140 in which tools such as a wrench can be inserted. If the wrench is inserted into the hole 140 of the tool holder 100, then the space between the top support surface 110 and the bottom support surface 120 is expanded and the cutting insert 1 can be easily replaced in the pocket 130 of the tool holder 100.

The tool holder 100 comprises a stopper 125 upwardly protruded from the bottom support surface 120. The stopper 125 is received in the recess 40 formed on the intersecting edge of the first bottom clamping surface 13 and the second bottom clamping surface 14 of the cutting insert 1. The stopper 125 comes into contact with the surfaces of the recess 40, and the cutting insert 1 can be mounted in the tool holder 100 at an accurate position. Since the first front cutting edge 15 and the second front cutting edge 25 of the cutting insert 1 are formed to be slanted at an angle of 65 to 125 degrees to each other, the first cutting portion 20 and the second cutting portion 30 can be placed in a machining position with only one recess 40 formed on the intersecting edge of the first bottom clamping surface 13 and the second bottom clamping surface 14. Thus, it is not necessary to separately make a recess for mounting the first cutting portion 20 and a recess for mounting the second cutting portion 30. The thickness reduction of the cutting insert 1 can be prevented and the strength of the cutting insert 1 can be improved.

Preferably, the tool holder 100 according to the present invention has a width smaller than that of the cutting insert 1. Thus, it is prevented that the tool holder 100 comes into contact with the grooved surfaces, and the deep groove machining can be performed easily without any limitation by the configuration of the tool holder 100.

Fig. 9 shows that the cutting insert 1 according to the present invention is mounted in the tool holder 100. A V-shaped receiving groove 15 is formed in the first top clamping surface 11 of the cutting insert 1. When the cutting insert 1 is mounted in the tool holder 100, the receiving groove 15 receives the top support surface 110 of the tool holder 100. As shown in Fig. 9, the contacting line or surface of the receiving groove 15 and the top support surface 110 is formed in a diagonal direction. Thus, when the cutting insert 1 is mounted in the tool holder 100, the longitudinal clamping force (directed to "L1" in Fig. 9) and lateral clamping force (directed to "W1" in Fig. 9) may be applied to the cutting insert 1 (see Fig. 10). Such longitudinal and lateral clamping forces can prevent the cutting insert 1 from moving longitudinally and laterally during the machining operations. For example, the longitudinal "L1" clamping force generated by the diagonal receiving groove 15 secures the cutting insert 1 between the top support surface 110 and the back support surface 150 of the tool holder 100 to prevent the cutting insert 1 from moving longitudinally. Further, the lateral "W1" clamping force generated by the diagonal receiving groove 15 secures the cutting insert 1 between the recess 40 of the cutting insert 1 and the top support surface 110 of the tool holder 100 to prevent the cutting insert 1 from moving laterally. Also, the cutting insert 1 has a V-shaped receiving groove 16 in the second top clamping surface 12. The receiving groove 16 provides the same functional effects as the receiving groove 15 when the second cutting portion 30 is placed in a machining position. The present embodiments are described that the receiving

grooves

15, 16 have the V-shape configuration. However, it is not intended to limit the configurations of the receiving

grooves

15, 16 as the V-shape. The receiving

grooves

15, 16 may have any configuration that the contacting line or surface of the receiving

grooves

15, 16 formed in the first top clamping surface 11 and the second top clamping surface 12 and a top support surface 110 of the tool holder 100 is formed in a diagonal direction when viewed from above the first top clamping surface 11 and the second top clamping surface 12.

Fig. 11 shows that the cutting insert 1 according to another embodiment of the present invention is mounted and supported in the tool holder 100. The first bottom clamping surface 13 of the cutting insert 1 according to the present embodiment comprises a first inclined surface 13a, which is slanted with respect to the first front cutting edge 25 with an acute angle. Further, the bottom support surface 120 of the tool holder 100 comprises an inclined surface, which is slanted at the same angle to the angle formed by the first inclined surface 13a and the first front cutting edge 25, so as to receive the cutting insert 1. Such first inclined surface 13a of the first bottom clamping surface 13 contacts with the bottom support surface 120 of the tool holder 100, which may provide longitudinal "L1" and lateral "W1" clamping forces to the cutting insert 1 when the cutting insert 1 is mounted in the tool holder such that the first cutting portion 20 is placed in a machining position (see Fig. 12). Due to such longitudinal and lateral clamping forces, the longitudinal and lateral movement of the cutting insert 1 during machining operations can be prevented. In particular, the above longitudinal "L1" clamping force can prevent the longitudinal "L2" movement of the cutting insert 1, while the back support surface 150 of the tool holder 100 can prevent the longitudinal "L1" movement of the cutting insert 1. Further, the above lateral "W1" clamping force can prevent the lateral "W2" movement of the cutting insert 1, while the contact of the recess 40 of the cutting insert 1 and the stopper 125 of the tool holder 100 can prevent the lateral "W1" movement of the cutting insert 1. Similar to the first bottom clamping surface 13, the second clamping surface 14 also comprises a second inclined surface 14a, which is slanted with respect to the second front cutting edge 35 with the same angle to the angle formed by the first inclined surface 13a, and the first front cutting edge 25 that provides the same functional effect as the first bottom clamping surface 13 when the second cutting portion 30 is placed in a machining position (see Fig. 12).

It is to be understood that the aforementioned embodiments of the present invention have been described by way of illustration and are not intended to limit the present invention. Numerous variation and modification can be made without departing from the spirit of the present invention by those of ordinary skilled in the art. For example, although the aforementioned embodiments have been described to be used for deep grooving, the cutting insert of the present invention may also be used for such as turning operation, etc.

Claims

A cutting insert comprising a body portion and a first cutting portion and a second cutting portion, the first and second cutting portions being formed in each end of the body portion and having a substantially same configuration with each other;

wherein the body portion comprises a first top clamping surface, a second top clamping surface adjacent to the first top clamping surface, a first bottom clamping surface opposite to the first top clamping surface, and a second bottom clamping surface opposite to the second top clamping surface, and wherein the first top clamping surface has a receiving groove and the second top clamping surface has a receiving groove;

wherein the first cutting portion comprises a first front surface, a first top surface extending from the first top clamping surface of the body portion to the first front surface, two side walls respectively extending from the second top clamping surface and the second bottom clamping surface of the body portion to the first front surface, a first front cutting edge formed at the intersection of the first front surface and the first top surface, and first side cutting edges formed at the intersection of the first top surface and the two side walls of the first cutting portion;

wherein the second cutting portion comprises a second front surface, a second top surface extending from the second top clamping surface of the body portion to the second front surface, two side walls respectively extending from the first top clamping surface and the first bottom clamping surface of the body portion to the second front surface, a second front cutting edge formed at the intersection of the second front surface and the second top surface, and second side cutting edges formed at the intersection of the second top surface and the two side walls of the second cutting portion;

wherein the first cutting portion and the second cutting portion are placed in different planes and are slanted at an angle with each other; and

wherein a recess for receiving a stopper of a tool holder is formed on the intersecting edge of the first bottom clamping surface and the second bottom clamping surface.
The cutting insert according to Claim 1, wherein the second front cutting edge is slanted at an angle of 65 to 125 degrees with respect to the first front cutting edge.
The cutting insert according to Claim 2, wherein when viewed from the front of the first front cutting edge or the second front cutting edge, the distance from the intersection of the first front cutting edge and the second front cutting edge to the end of the first front cutting edge is identical to the distance from the intersection of the first front cutting edge and the second front cutting edge to the end of the second front cutting edge.
The cutting insert according to Claim 1, wherein the contacting line or surface of the receiving groove formed in the first top clamping surface and a top support surface of the tool holder is formed in a diagonal direction when viewed from above the first top clamping surface.
The cutting insert according to Claim 1, wherein the contacting line or surface of the receiving groove formed in the second top clamping surface and a top support surface of the tool holder is formed in a diagonal direction when viewed from above the first top clamping surface.
The cutting insert according to Claim 1, wherein the first bottom clamping surface comprises: a first inclined surface slanted with respect to the first front cutting edge with an acute angle; and the second bottom clamping surface comprises a second inclined surface slanted with respect to the second front cutting edge with the same angle to the angle formed by the first inclined surface and the first front cutting edge.
The cutting insert according to any one of Claims 4 to 6, wherein the cutting insert may be slidably inserted into the pocket of the tool holder from the side of the tool holder.
The tool holder comprising a pocket for mounting the cutting insert according to Claim 4 or 5;

wherein the pocket comprises a top support surface where the first top clamping surface or the second top clamping surface of the cutting insert is mounted, a bottom support surface where the first bottom clamping surface or the second bottom clamping surface of the cutting insert is mounted, and a stopper configured to upwardly protrude from the bottom support surface to be received in the recess of the cutting insert; and

wherein the top support surface is configured such that the contacting line or surface of the receiving grooves of the cutting insert and the top support surface of the tool holder is formed in a diagonal direction when viewed from above the top support surface.
The tool holder comprising a pocket for mounting the cutting insert according to Claim 6,

wherein the pocket comprises a top support surface where the first top clamping surface or the second top clamping surface of the cutting insert is mounted, a bottom support surface where the first bottom clamping surface or the second bottom clamping surface of the cutting insert is mounted, and a stopper configured to protrude upwardly from the bottom support surface to be received in the recess of the cutting insert; and

wherein the bottom support surface of the tool holder is slanted at the same angle to the angle formed by the first inclined surface and the first front cutting edge.