Modular rotary cutting tool

Abstract

A rotary cutting tool comprising a shank is disclosed, and interchangeable cutting inserts are provided. The shank comprises a pocket for receiving the interchangeable cutting insert. The pocket includes a floor with a central pin receiving hole, opposing pocket centering walls, and a torque-transmitting pocket drive wall. The cutting insert has a relatively long rear pin that can be received in the central hole of the shank. The head of the cutting insert includes an insert centering surface that contacts the pocket centering wall of the shank and an insert drive surface that contacts the torque-transmitting pocket drive wall of the shank. The configuration and size of the features of the shank and cutting insert are controlled to provide improved torque transmission, rigidity, and stability during operation of the rotary cutting tool.

Description

[Technical Field]

[0001] The present invention relates to a modular rotary cutting tool, including a shank and interchangeable cutting inserts. [Background technology]

[0002] Drills with interchangeable cutting tips are known. Typically, the cutting head and shank can exhibit a continuous and complementary configuration as a grooved drill. Each shank usually includes a structure for holding and rotating the associated cutting head, while the associated cutting head has a complementary structure for being held and rotated by the shank. Issues such as deformation and failure are encountered during the service life of a drill due to the concentration of stress placed on the shank's holding and driving structure during normal service. This can excessively limit the useful service life of the drill. [Overview of the Initiative]

[0003] A rotary cutting tool is provided, comprising a shank and interchangeable cutting inserts. The shank comprises a pocket for receiving the interchangeable cutting inserts. The pocket includes a floor with a central pin receiving hole, opposing pocket centering walls, and a torque-transmitting pocket drive wall. The cutting insert has a relatively long rear pin receivable into the central hole of the shank. The head of the cutting insert includes an insert centering surface that contacts the pocket centering wall of the shank and an insert drive surface that contacts the torque-transmitting pocket drive wall of the shank. The configuration and size of the features of the shank and cutting insert are controlled to provide improved torque transmission, rigidity, and stability during operation of the rotary cutting tool.

[0004] One aspect of the present invention provides a modular rotary cutting tool comprising a shank having a central longitudinal axis and a cutting insert removably mounted on the shank. The shank includes a front pocket along with a central pin receiving hole. The cutting insert includes a pin receivable in the pin receiving hole of the shank. The front pocket includes first and second opposing pocket centering walls, first and second torque-transmitting pocket drive walls, and a pocket floor. The first pocket centering wall defines a plane, and the first pocket drive wall defines another plane, and the first pocket centering wall plane and the first pocket drive wall plane intersect at a pocket intersection P located on the pocket floor at a pocket wall angle A measured at the pocket intersection P, which is greater than 90° and less than 155°, and each of the first and second pocket drive walls is positioned in a plane parallel to the longitudinal axis of the shank.

[0005] Another aspect of the present invention is to provide a shank for a modular rotary cutting tool having a central longitudinal axis and including a central pin receiving hole and a front pocket. The front pocket includes first and second opposing pocket centering walls, first and second torque-transmitting pocket drive walls, and a pocket floor. The first pocket centering wall defines a plane, and the first pocket drive wall defines another plane, and the first pocket centering wall plane and the first pocket drive wall plane intersect at a pocket intersection P located on the pocket floor, at a pocket wall angle A measured at the intersection P, which is greater than 95° and less than 155°, and each of the first and second pocket drive walls is positioned in a plane parallel to the longitudinal axis of the shank.

[0006] A further aspect of the present invention provides a cutting insert for a modular rotary cutting tool having a central longitudinal axis and comprising a head and a pin extending rearward from the head. The head includes first and second insert centering surfaces, first and second torque-transmitting insert driving surfaces, and a rear surface. The first insert centering surface defines a plane, and the first insert driving surface defines another plane, and the first insert centering surface plane and the first insert driving surface plane intersect at an insert intersection P' located on the plane of the rear surface, at an insert surface angle A' measured at the insert intersection P', which is greater than 90° and less than 155°, and each of the first and second insert driving surfaces is positioned in a plane parallel to the longitudinal axis of the shank.

[0007] Another aspect of the present invention is the length L measured in the axial direction of the cutting insert. H A head having a length L P A cutting insert for a modular rotary cutting tool, comprising a pin extending axially rearward from the head, wherein the pin-to-head length ratio L P :L H The objective is to provide cutting inserts for modular rotary cutting tools with a ratio greater than 1:1.

[0008] A further aspect of the present invention is to provide a cutting insert for a modular rotary cutting tool having a central longitudinal axis, including a cutting head, comprising first and second insert centering surfaces, first and second torque-transmitting insert drive surfaces, and a rear surface. The first insert centering surface defines a plane, and the first insert drive surface defines another plane, and the first insert centering surface plane and the first insert drive surface plane intersect at an insert intersection P' located on the plane of the rear surface, with an insert surface angle A' measured at the intersection P', where the insert surface angle A' is greater than 90° and less than 155°. Each of the first and second insert drive surfaces is positioned in a plane parallel to the longitudinal axis of the shank.

[0009] These and other aspects of the present invention will become more apparent from the following description. [Brief explanation of the drawing]

[0010] [Figure 1] Figures 1 and 2 are isometric views of the modular rotary cutting tool of the present invention, including the shank and interchangeable cutting inserts. [Figure 2] Figures 1 and 2 are isometric views of the modular rotary cutting tool of the present invention, including the shank and interchangeable cutting inserts. [Figure 3] Figures 3 and 4 are side views of the modular rotary cutting tool of the present invention, including the shank and interchangeable cutting inserts. [Figure 4] Figures 3 and 4 are side views of the modular rotary cutting tool of the present invention, including the shank and interchangeable cutting inserts. [Figure 5] Figure 5 is a front view of the modular rotary cutting tool of the present invention, including the shank and interchangeable cutting inserts. [Figure 6] Figures 6 to 8 are side cross-sectional views of the modular rotary cutting tool of the present invention, including the shank and interchangeable cutting inserts, taken through the various lines in Figure 5. [Figure 7] Figures 6 to 8 are side cross-sectional views of the modular rotary cutting tool of the present invention, including the shank and interchangeable cutting inserts, taken through the various lines in Figure 5. [Figure 8] Figures 6 to 8 are side cross-sectional views of the modular rotary cutting tool of the present invention, including the shank and interchangeable cutting inserts, taken through the various lines in Figure 5. [Figure 9] Figure 9 is an isometric view of the rotary cutting tool shank shown in Figures 1 to 8. [Figure 10] Figures 10 to 12 are side views of the rotary cutting tool shank shown in Figures 1 to 8. [Figure 11] Figures 10 to 12 are side views of the rotary cutting tool shank shown in Figures 1 to 8. [Figure 12] Figures 10 to 12 are side views of the rotary cutting tool shank shown in Figures 1 to 8. [Figure 13] Figure 13 is a front view of the rotary cutting tool shank shown in Figures 1 to 8. [Figure 14] Figures 14 to 16 are isometric views of the cutting inserts shown in Figures 1 to 8. [Figure 15] Figures 14 to 16 are isometric views of the cutting inserts shown in Figures 1 to 8. [Figure 16] Figures 14 to 16 are isometric views of the cutting inserts shown in Figures 1 to 8. [Figure 17] Figures 17 and 18 are side views of the cutting inserts shown in Figures 1 to 8. [Figure 18] Figures 17 and 18 are side views of the cutting inserts shown in Figures 1 to 8. [Figure 19] Figure 19 is a front view of the cutting insert shown in Figures 1 to 8. [Figure 20] Figure 20 is a rear view of the cutting insert shown in Figures 1 to 8. [Figure 21] Figures 21 to 23 are isometric views of another cutting insert of the present invention. [Figure 22] Figures 21 to 23 are isometric views of another cutting insert of the present invention. [Figure 23] Figures 21 to 23 are isometric views of another cutting insert of the present invention. [Figure 24] Figures 24 and 25 are side views of another cutting insert of the present invention. [Figure 25] Figures 24 and 25 are side views of another cutting insert of the present invention. [Figure 26] Figure 26 is a front view of another cutting insert of the present invention. [Figure 27] Figure 27 is a rear view of a different cutting insert according to the present invention. [Figure 28] Figures 28 to 30 are isometric views of further cutting inserts of the present invention. [Figure 29]Figures 28 to 30 are isometric views of further cutting inserts of the present invention. [Figure 30] Figures 28 to 30 are isometric views of further cutting inserts of the present invention. [Figure 31] Figures 31 and 32 are side views of further cutting inserts of the present invention. [Figure 32] Figures 31 and 32 are side views of further cutting inserts of the present invention. [Figure 33] Figure 33 is a front view of the further cutting insert of the present invention. [Figure 34] Figure 34 is a rear view of the further cutting insert of the present invention. [Figure 35] Figures 35 to 37 are isometric views of another cutting insert of the present invention. [Figure 36] Figures 35 to 37 are isometric views of another cutting insert of the present invention. [Figure 37] Figures 35 to 37 are isometric views of another cutting insert of the present invention. [Figure 38] Figures 38 and 39 are side views of another cutting insert of the present invention. [Figure 39] Figures 38 and 39 are side views of another cutting insert of the present invention. [Figure 40] Figure 40 is a front view of another cutting insert of the present invention. [Figure 41] Figure 41 is a rear view of a different cutting insert according to the present invention. [Figure 42] Figure 42 is a side view of the modular rotary cutting tool of the present invention, including the shank and interchangeable cutting inserts. [Figure 43] Figure 43 is a front view of the rotary cutting tool shown in Figure 42. [Figure 44] Figure 44 is a side cross-sectional view of the rotary cutting tool taken through line 44-44 in Figure 43. [Figure 45] Figures 45 and 46 are partial side views of the rotary cutting tool shank shown in Figures 42 to 44. [Figure 46]Figures 45 and 46 are partial side views of the rotary cutting tool shank shown in Figures 42 to 44. [Figure 47] Figure 47 is a front view of the rotary cutting tool shank shown in Figures 42 to 44. [Figure 48] Figures 48 and 49 are side views of the cutting inserts shown in Figures 42 to 44. [Figure 49] Figures 48 and 49 are side views of the cutting inserts shown in Figures 42 to 44. [Figure 50] Figure 50 is a front view of the cutting insert shown in Figures 42 to 44. [Figure 51] Figure 51 is a side cross-sectional view taken through line 51-51 in Figure 50, showing the cutting insert and set screw. [Figure 52] Figure 52 is a rear view of the cutting insert shown in Figures 42-44 and 50. [Figure 53] Figure 53 is a partial schematic side view of a portion of the cutting insert shown in Figures 48 to 52, showing the details of the cutting insert's pins and the arrangement of the set screws. [Figure 54] Figure 54 is a partial schematic side view illustrating the features of a bump-off tool that may be used to facilitate the removal of a cutting insert from a rotary cutting tool shank according to the present invention. [Figure 55] Figure 55 is a side cross-sectional view taken through line 55-55 of Figure 54, showing the features of a bump-off tool that may be used to facilitate the removal of a cutting insert from a rotary cutting tool shank according to the present invention. [Figure 56] Figure 56 is a side cross-sectional view taken through line 56-56 of Figure 55, showing the features of a bump-off tool that may be used to facilitate the removal of a cutting insert from a rotary cutting tool shank according to the present invention. [Figure 57] Figure 57 is a partial schematic side view showing the bump-off tools from Figures 54-56 in their insertion position within the shank of the rotary cutting tool. [Figure 58]Figure 58 is a side cross-sectional view taken through line 58-58 in Figure 57, showing the bump-off tools of Figures 54-56 in their insertion position within the shank of the rotary cutting tool. [Figure 59] Figure 59 is a side cross-sectional view taken through line 59-59 in Figure 58, showing the bump-off tools of Figures 54-56 in their insertion position within the shank of the rotary cutting tool. [Modes for carrying out the invention]

[0011] Figures 1 to 20 illustrate a modular rotary cutting tool 5 in the form of a drill, having a shank 10 and interchangeable cutting inserts 30. A central longitudinal axis is defined through the cutting tool 5, which is common to both the shank 10 and the cutting inserts 30. The modular rotary cutting tool of the present invention performs rotary cutting operations on a workpiece and may include drills, countersinking tools, milling tools, reaming tools, and the like.

[0012] The shank 10 includes a pair of grooves 11 along the side of the shank 10, and a front pocket 12. The front pocket 12 includes opposing centering walls 14 and torque-transmitting drive walls 15. Each pocket drive wall 15 intersects with one of the adjacent pocket centering walls 14. A pocket floor 16 is provided at the bottom of the pocket 12. As will be described in more detail below, each pocket centering wall 14 and adjacent pocket drive walls 15 define a plane that intersects with each other at the floor 16 at intersection P. The position of intersection P, as well as the pocket wall angle A where the centering walls 14 and drive walls 15 intersect, are controlled to provide improved torque transmission, rigidity, and stability during the operation of the rotary cutting tool, as will be described in more detail below.

[0013] As most clearly shown in the side view of Figure 12, each pocket centering wall 14 of the pocket 12 may be slightly inclined at a seating angle S, which is typically greater than 0°, e.g., greater than or greater than 0.1°, or greater than 0.5°, or greater than 1°. The seating angle S may typically be less than 5°, or less than 4°, or less than 3°. The seating angle S may typically be in the range of 0.5 to 5°, e.g., 1 to 4°, or 1.5 to 3.5°, or 2 to 3°. As shown in Figure 12, the seating angle S for each of the pocket centering walls 14 may be the same. As will be described in more detail below, the pocket drive walls 15 may be parallel to each other in a plane parallel to the central longitudinal axis of the shank 10.

[0014] As shown in Figure 9, coolant holes 18 and 19 may be provided on the front surface of the shank 10, on both sides of the pocket 12. The coolant holes 18 and 19 shown in Figure 9 are of different sizes. Alternatively, the coolant holes may be the same size. As shown in Figures 4 and 8, the coolant supply hole 28 may be provided through the side wall of the shank 10.

[0015] As most clearly shown in Figures 6 to 13, the central pin receiving hole 20 extends from the pocket floor 16 into the shank 10 along its central longitudinal axis. The pin receiving hole 20 includes a rear contact area 21 structured and positioned to engage with the rear end 42 of the cutting insert pin 40, as will be described in more detail below. The pin receiving hole 20 also includes a front contact area 22 that can engage with the front end 41 of the pin 40, as will be described in more detail below. A threaded set screw hole 24 extends at an angle through the side of the shank 10 and intersects with the pin receiving hole 20. A set screw 26 is receivable by being screwed into the set screw hole 24.

[0016] As most clearly shown in Figures 14 to 20, the cutting insert 30 has a central longitudinal axis and includes a head 31, a rear surface 32, and a front tip 33. A helical groove 34 runs along the side of the head 31. A side edge 35 is provided adjacent to the groove 34. Furthermore, a front cutting edge 36 is provided in front of the cutting insert head 31. The front cutting edge 36 may be cut into the workpiece as the rotary cutting tool 5 is rotated. When the cutting insert 30 is mounted on the shank 10, the corresponding grooves 11 and 34 of the shank 10 and the cutting insert 30 align, respectively, to form substantially continuous grooves 11, 34. Although two grooves are shown, any other number of grooves, e.g., one groove, three grooves, etc., may be provided.

[0017] The cutting insert 30 includes a centering surface 37 and a torque transmission drive surface 38, which are structured and positioned to engage with the respective pocket centering walls 14 and pocket drive walls 15 of the front pocket 12 of the shank 10. The insert centering surfaces 37 may be slightly angled relative to each other to match the seating angle S of the respective pocket centering walls 14. The insert drive surfaces 38 may be parallel to each other and parallel to the central longitudinal axis of the insert 30 to match the parallel arrangement of the pocket drive walls 15.

[0018] The pin 40 extends rearward from the rear surface 32 of the head 31 of the cutting insert 30. In the embodiments shown, the pin 40 and the head 31 may be supplied as a single or integrated piece of material, but alternatively, they may be supplied as separate components that are joined together, screwed in, or otherwise mechanically fastened. As shown in Figures 17 and 18, the pin 40 includes a front end 41 and a rear end 42. Opposing notches 44 having set screw contact surfaces 45 extend radially inward on both sides of the pin 40. The pin 40 includes a front portion 46 and a tail portion 48, which are divided by the opposing notches 44. The structure and size of the cutting insert head 31 and the pin 40, including their relative dimensions, are controlled in accordance with the present invention, as will be described in more detail below.

[0019] As shown in FIG. 12, the shank 10 has a shank diameter D S and. As shown in FIG. 13, each pocket centering wall 14 and the adjacent pocket drive wall 15 define a plane that intersects each other in the plane of the pocket floor 16 at the pocket intersection P. The pocket wall angle A is defined at the pocket intersection P, where the planes of the pocket centering wall 14 and the pocket drive wall 15 intersect. The pocket offset distance Y is defined, as shown in FIG. 13, as the distance measured on the pocket floor 16 in the plane of the pocket centering wall 14 that extends perpendicularly from the plane in which the central longitudinal axis of the shank 10 is located to the pocket intersection P. As further shown in FIGS. 12 and 13, the pocket 12 has a centering wall width W C measured at the pocket floor 16, and a drive wall width W D measured at the pocket floor 16. As will be more fully described below, the planar surface areas of each centering wall 14 and the adjacent drive wall 15 can be selected in relation to each other. By controlling the structure, arrangement, and dimensions of the above-described features, the shank of the present invention provides favorable characteristics such as improved torque transmission, rigidity, and stability during the operation of the rotary cutting tool.

[0020] As shown in FIGS. 17 and 20, each insert centering surface 37 and the adjacent insert drive surface 38 define a plane that intersects each other in the plane of the flank 32 at the insert intersection P'. The insert surface angle A' is defined at the insert intersection P'. The insert offset distance Y' is defined, as shown in FIG. 20, as the distance measured on the flank 32 in the plane of the centering surface 37 that extends perpendicularly from the plane in which the central longitudinal axis of the cutting insert 30 is located to the insert intersection P'. As further shown in FIG. 20, the insert has an insert centering surface width W' C measured at the flank 32, and a drive surface width W' DThe planar surface area of ​​each centering surface 37 and the adjacent driving surface 38 can be selected in relation to each other, as will be described in more detail below. According to the present invention, the insert surface angle A', insert offset distance Y', and other structural features described above are controlled to provide improved torque transmission, rigidity, and stability during the operation of the rotary cutting tool.

[0021] Figures 21 to 27 illustrate a cutting insert 130 according to another embodiment of the present invention. The cutting insert 130 includes a centering surface 137 and a torque transmission drive surface 138. The cutting insert 130 includes a rearward-extending pin 140 that extends rearward from the rear surface 132 of the head of the cutting insert 130, having opposing notches 144. As shown in Figure 27, the cutting insert 130 has an insert intersection P', an insert surface angle A', an insert offset distance Y', and an insert centering surface width W. C , and insert drive surface width W D It has.

[0022] Figures 28 to 34 illustrate another cutting insert 230 according to an embodiment of the present invention. The cutting insert 230 includes a centering surface 237 and a torque transmission drive surface 238. A relief channel 239 is provided between adjacent centering surfaces 237 and torque transmission drive surfaces 238. The cutting insert 230 includes a pin 240 extending rearward from the rear surface 232 of the head of the cutting insert 230, having opposing notches 244. As shown in Figure 34, the cutting insert 230 has an insert intersection P', an insert surface angle A', an insert offset distance Y', and an insert centering surface width W C , and insert drive surface width W D It has.

[0023] Figures 35 to 41 illustrate a cutting insert 330 according to a further embodiment of the present invention. The cutting insert 330 includes a centering surface 337 and a torque transmission drive surface 338. A relief channel 339 is provided between adjacent centering surfaces 337 and torque transmission drive surfaces 338. The cutting insert 330 includes a pin 340 extending rearward from the rear surface 332 of the head of the cutting insert 330, having opposing notches 344. As shown in Figure 41, the cutting insert 330 has an insert intersection P', an insert surface angle A', an insert offset distance Y', and an insert centering surface width W. C , and insert drive surface width W D It has.

[0024] Figures 42 to 51 illustrate another modular rotary cutting tool 405 of the present invention, which includes a shank 410 and a cutting insert 430 having features common to some of those described in the embodiments above. The shank 410 includes a helical groove 411 and a front pocket 412. A floor 416 is provided at the bottom of the pocket 412. The pocket 412 includes opposing centering walls 414 and torque-transmitting drive walls 415. As shown in Figure 45, the centering walls 415 of the pocket 416 can be oriented at a seating angle S which can be selected as described above. Coolant holes 418 are provided on the front of the shank 410 on both sides of the pocket 412 and may be the same size or different sizes. The shank 410 includes a central pin receiving hole 420 having a tail contact area 421 and a front contact area 422, as will be described in more detail below. As most clearly shown in Figures 44 and 53, the threaded set screw hole 424 receives the threaded set screw 426 and extends at an angle B with respect to the longitudinal axis of the shank 410 from the side of the shank to the pin receiving hole 420. The bump-off hole 428 extends radially through the side of the shank 410 and intersects with the pin receiving hole 420.

[0025] The cutting insert 430 includes a head 431, a rear surface 432, and a front tip 433. A helical groove 434 is provided along the side of the cutting insert 430. A side edge 435 is provided adjacent to the groove 434, and a front cutting edge 436 is provided in front of the head 431.

[0026] The cutting insert 430 includes a centering surface 437 and a torque transmission drive surface 438. As described in the embodiments above, the insert centering surfaces 437 may be slightly angled relative to each other to match the seating angle S of each pocket centering wall 414 of the pocket 412 of the shank 410. The insert drive surfaces 438 may be parallel to each other in a plane parallel to the central longitudinal axis of the cutting insert 430. Relief channels 439 are provided between adjacent centering surfaces 437 and torque transmission drive surfaces 438.

[0027] The cutting insert 430 includes a pin 440 having a front end 441 and a rear end 442. As described above, the pin 440 may be formed integrally with the head 431 or provided as a separate component joined or mechanically fixed to the head 431. For example, the head 431 may include a carbide material, and the pin 440 may include a steel material fixed to the head. Opposing notches 444 including a set screw contact surface 445 are provided on the side of the pin 440. The pin 440 includes a front portion 446 and a tail portion 448, which are divided by the opposing notches 444. In the shown embodiment, the notches 444 are located on both sides of the pin 440, spaced 180° apart from each other in the circumferential direction. Alternatively, a single groove may extend 360° circumferentially around the pin 440.

[0028] Shank 410 has a diameter D S The pocket 412 has a centering wall width W measured at the pocket floor 416, as shown in Figure 45. C It has a drive wall width W as shown in Figure 46. DAs shown in Figure 47, each pocket centering wall 414 and the adjacent pocket drive wall 415 define a plane that intersects with each other in the plane of the pocket floor 416 at the pocket intersection P. The pocket wall angle A is defined at the pocket intersection P where the planes of the pocket centering wall 414 and the pocket drive wall 415 intersect. The pocket offset distance Y is defined as the distance measured on the pocket floor 416 in the plane of the pocket centering wall 414, extending perpendicularly from the plane where the central longitudinal axis of the shank 10 is located to the pocket intersection P, as shown in Figure 47. As further shown in Figures 45 to 47, the pocket 412 has a centering wall width W measured in the pocket floor 416. C , and the drive wall width W measured in the pocket floor 416 D The planar surface area of ​​each centering wall 414 and the adjacent drive wall 415 can be selected relative to each other. The planar surface area of ​​each pocket centering wall 414 is SA C It may be specified as, on the other hand, the planar surface area of ​​each pocket drive wall 415 is SA D It may be specified as follows: Pocket drive wall surface area SA D This refers to the pocket centering wall surface area SA C The percentage of that, i.e., SA D / SA C This can be controlled as a percentage. By controlling the structure, arrangement, and dimensions of the features described above, the shank of the present invention provides desirable properties such as improved torque transmission, rigidity, and stability during the operation of a rotary cutting tool.

[0029] As shown in Figures 50 and 52, the head of the insert 430 has an insert head diameter D H Insert centering surface width W' C , and insert drive surface width W' DAs shown in Figure 52, each insert centering surface 437 and the adjacent insert driving surface 438 define a plane that intersects with each other in the plane of the rear surface 432 at the insert intersection P'. The insert surface angle A' is defined at the insert intersection P'. The insert offset distance Y' is defined as the distance measured on the rear surface 432 in the plane of the centering surface 437, extending perpendicularly from the plane where the central longitudinal axis of the cutting insert 430 is located at the insert intersection P', as shown in Figure 52. Further shown in Figure 52, the insert has an insert centering surface width W' measured at the rear surface 432. C , and the drive surface width W' measured on the rear surface 432 D The planar surface area of ​​each centering surface 437 and the adjacent driving surface 438 can be selected relative to each other. The planar surface area of ​​each insert centering surface 414 is SA' C It may also be specified as such, while the planar surface area of ​​each insert drive surface 415 is SA' D It may also be specified as: Insert drive area SA' D This is the insert centering surface SA' C The percentage of that, i.e., SA' D / SA' C This can be controlled as a percentage. According to the present invention, the insert surface angle A', insert offset distance Y', and other structural features are controlled to provide improved torque transmission, rigidity, and stability during the operation of the rotary cutting tool.

[0030] As most clearly shown in Figures 51 and 53, pin 440 has a total length L P , and the tail length L measured from behind the notch 444 to the rear end 442 of the pin. T It has. Pin 440 has a diameter D PAs further shown in Figure 53, the set screw 426 is provided with a set screw angle B measured between the central longitudinal axis of the set screw 426 and the central longitudinal axis of the pin 440. The set screw angle B corresponds to a similar angle of the set screw hole 424 in the shank 410, as shown in Figure 44, measured between the central longitudinal axis of the set screw hole 424 and the central longitudinal axis of the shank 410. The set screw angle B, and the corresponding set screw hole angle, may typically be 20–40°, for example, 25–35°, or 28–32°. As schematically shown in Figure 53, during the installation and retention of the cutting insert 430 in the shank 410, the set screw 426 exerts a set screw force F along the longitudinal axis of the set screw 426 at the set screw angle B. S This generates the set screw force F, as described above more precisely. S The axial component F acts to push the pin 440 axially into the pin receiving hole 420. A , and a radial component F that acts to radially push a portion of the pin 440 against the opposing surface of the pin receiving hole 420, thereby bending or deforming the pin 440 by a controlled amount. R It has.

[0031] A clearance gap G is provided between the pin 440 and the pin receiving hole 420 of the shank 410. The provision of such a clearance gap G reduces the set screw force F S The radial component F R This allows the tail 448 of the pin 440 to deform by a radially controlled amount along the direction. This enables the tail contact region C of the tail 448 to engage with the opposing rear inner surface 421 of the pin receiving hole 420. T This is created. Front contact area C in the front part 446 of pin 440 F It may also be in contact with the opposing front inner surface 442 of the pin receiving hole 420.

[0032] The pocket wall angle A described above may be greater than 90°, greater than 125°, greater than 135°, or greater than 140°. The pocket wall angle A may be less than 155°, less than 150°, less than 148°, or less than 145°. The pocket wall angle A may be in the range of 90 to 150°, for example, 125 to 150°, or 135 to 148°, or 140 to 145°.

[0033] The insert surface angle A' described above may be greater than 90°, greater than 125°, greater than 135°, or greater than 140°. The insert surface angle A' may be less than 155°, less than 150°, less than 148°, or less than 145°. The insert surface angle A' may be in the range of 90 to 150°, for example, 125 to 150°, or 135 to 148°, or 140 to 145°.

[0034] The pocket offset distance Y is given by the shank diameter D. S It can be selected as a percentage of that. Y / D S The percentage may be greater than 0.5%, or greater than 1%, or greater than 2%, or greater than 2.5%, or greater than 3%, or greater than 5%. Y / D S The percentage may be less than 20%, less than 17%, or less than 15%. Y / D S The percentage can range from 1 to 20%, for example, 2.5 to 17%, or 3 to 15%, or 5 to 14%.

[0035] The insert offset distance Y' mentioned above is equal to the insert head diameter D. H It can be selected as a percentage of that. Y' / D H The percentage may be greater than 0.5%, or greater than 1%, or greater than 2%, or greater than 2.5%, or greater than 3%, or greater than 5%. Y' / D H The percentage may be less than 20%, less than 17%, or less than 15%. Y' / D HThe percentage can range from 1 to 20%, for example, 2.5 to 17%, or 3 to 15%, or 5 to 14%.

[0036] The above-mentioned pocket centering wall width W C The shank diameter D S It can be selected as a percentage of that. C / D S The percentage may be greater than 15%, greater than 16%, or greater than 18%. C / D S The percentage may be less than 30%, or less than 28%, or less than 25%, or less than 23%. C / D S The percentage could be in the range of 15-30%, for example, 16-28%, 18-25%, or 18-23%.

[0037] The insert centering surface width W' described above. C The insert head diameter is D H It can be selected as a percentage of that. C / D H The percentage may be greater than 15%, or greater than 16%, or greater than 18%. C / D H The percentage may be less than 30%, or less than 28%, or less than 25%, or less than 23%. C / D H The percentage could be in the range of 15-30%, for example, 16-28%, 18-25%, or 18-23%.

[0038] The above-mentioned pocket drive wall width W D This is a pocket centering wall width W C It can be selected as a percentage of that. D / W C The percentage may be greater than 1%, or greater than 10%, or greater than 15%, or greater than 25%, or greater than 28%. D / W CThe percentage may be less than 100%, or less than 90%, or less than 85%, or less than 75%, or less than 60%. W D / W C The percentage may range from 1 to 100%, for example, from 10 to 90%, or from 15 to 85%, or from 25 to 75%, or from 28 to 60%.

[0039] The above insert drive surface width W’ D may be selected as a percentage of the insert centering surface width W’ C W’ D / W’ C The percentage may be more than 1%, or more than 10%, or more than 15%, or more than 25%, or more than 28%. W’ D / W’ C The percentage may be less than 100%, or less than 90%, or less than 85%, or less than 75%, or less than 60%. W’ D / W’ C The percentage may range from 1 to 100%, for example, from 10 to 90%, or from 15 to 85%, or from 25 to 75%, or from 28 to 60%.

[0040] The pocket drive wall surface area SA D may be selected as a percentage of the pocket centering wall surface area SA C SA D / SA C The percentage may be more than 30%, or more than 34%, or more than 50%, or more than 70%, or more than 75%. SA D / SA C The percentage may be less than 200%, or less than 190%, or less than 145%, or less than 130%, or less than 120%. SA D / SA C The percentage may range from 40 to 170%, for example, from 45 to 165%, or from 50 to 135%, or from 65 to 125%.

[0041] The insert drive surface area SA’ DThe insert centering area SA' C It can be selected as a percentage of that. D / SA' C The percentage may be greater than 30%, greater than 34%, greater than 50%, greater than 70%, or greater than 75%. D / SA' C The percentage may be less than 200%, or less than 190%, or less than 145%, or less than 130%, or less than 120%. SA' D / SA' C The percentages can range from 40% to 170%, for example, 45% to 165%, or 50% to 135%, or 65% to 125%.

[0042] Total insert pin length L P and insert head length L H L can be selected as a certain ratio. P :L H The ratio may be greater than 1:1, or greater than 1.05:1, or greater than 1.1:1. P :L H The ratio may be less than 2:1, or less than 1.9:1, or less than 1.8:1, or less than 1.5:1. P :L H The ratio can range from 1:1 to 2:1, for example, 1.1:1 to 1.8:1, or 1.1:1 to 1.6:1, or 1.1:1 to 1.5:1.

[0043] Pin tail length L T The total pin length is L P It can be selected as a percentage of that. T / L P The percentage may be greater than 20%, or greater than 22%, or greater than 24%, or greater than 25%. T / L P The percentage may be less than 40%, or less than 35%, or less than 33%, or less than 32%. T / L PThe percentage could be in the range of 20-40%, for example, 22-35%, 24-33%, or 25-32%.

[0044] Total pin length L P and pin diameter D P L can be selected as a certain ratio. P :D P The ratio may be greater than 3:1, or greater than 3.2:1, or greater than 3.4:1, or greater than 3.5:1. P :D P The ratio may be less than 6:1, or less than 5:1, or less than 4:5.1, or less than 4.0:1. P :D P The ratio can range from 3.0:1 to 6.0:1, for example, 3.2:1 to 5:1, or 3.4:1 to 4.5:1, or 3.5:1 to 4.0:1.

[0045] Pin tail length L T and pin diameter D P L can be selected as a certain ratio. T :D P The ratio may be greater than 0.95:1, or greater than 1.0:1, or greater than 1.05:1. T :D P The ratio may be less than 2.0:1, or less than 1.8:1, or less than 1.6:1, or less than 1.5:1. T :D P The ratio can range from 0.95:1 to 2.0:1, for example, 1.0:1 to 1.8:1, or 1.0:1 to 1.6:1, or 1.05:1 to 1.5:1.

[0046] Pin diameter D P The insert head diameter is D H It can be selected as a percentage of that. P / D H The percentage may be greater than 15%, or greater than 17%, or greater than 19%, or greater than 20%. P / D H The percentage may be less than 30%, or less than 27%, or less than 25%, or less than 24%.P / D H The percentage could be in the range of 15-30%, for example, 17-27%, 19-25%, or 20-24%.

[0047] For example, the clearance gap G between hole 420 and pin 440 may be greater than 0 mm, or greater than 0.002 mm, or greater than 0.003 mm, or greater than 0.004 mm, or greater than 0.005 mm. The clearance gap G may also be less than 0.1 mm, or less than 0.08 mm, or less than 0.05 mm. The clearance gap G may be in the range of 0.002 to 0.1 mm, or 0.003 to 0.08 mm, or 0.004 to 0.06 mm, or 0.005 to 0.05 mm.

[0048] This pocket and insert design provides excellent torque transmission capability, rigidity, and stability under lateral loads. A good correlation has been found between the offset distance and performance. When the offset distance falls within the values ​​listed above, the pocket stress is under controlled limits that provide a robust design. The resulting contact area between the pocket centering wall and the insert centering surface has been found to be large enough to avoid premature wear under periodic loads. By providing the offset distance described herein, a small contact area may be provided between the pocket centering wall and the insert centering surface, which helps in torque transmission along with torque transmission from the pocket drive wall to the insert drive surface. The stress caused by the additional contact in the centering portion acts in a different area than the stress generated by the torque transmitted within the drive region. However, excessively large offset distances result in an insert cross-section that is too small, which can become the weakest point in the system.

[0049] Due to the gap G between the pin 440 and the pin receiving hole 420, and the angle B from the longitudinal axis of the set screw to the longitudinal axis of the pin, the force applied by the set screw 426 creates a vertical component necessary for tightening and a lateral component that tends to bend the pin, allowing it to tighten the insert at a slight incline or off-center. The deformation of the pin 440 and the contact between its tail 448 and the opposing inner wall of the pin receiving hole 420 enhance stability and reduce relative movement between the cutting insert 430 and the pocket 412, especially when vibrating lateral loads are generated during drilling operations, for example, in the case of drilling on an angled surface or cross-hole.

[0050] High L P / D P By using a pin with a ratio, contact between the pin and the hole is achieved, allowing for the application of additional tightening force without generating extra stress on the pin near the seating surface. Longer pins can also store more elastic deformation than shorter pins, which preloads and maintains the system, preventing loosening of the set screw due to vibration, wear, or thermal expansion components. The combination of a long pin and a small angle B, which allows for longer set screws, leads to a greater sum of elastic deformation, such as stored energy. By making the pin longer, there is sufficient contact between the pin and the hole, and the rigidity of the system can be increased due to the relatively large diameter of the pin. The high pressure caused by the contact is relatively high L T :D P It can be reduced by providing a ratio, high L P :D P Ratio and high L T :D P The combination with ratios results in an improved design.

[0051] Furthermore, the selected L T :D P The ratio creates a sufficient support area to minimize contact pressure with the hole. Higher contact pressure is found on the tail portion, and the stiffness of the pin (L) P / D PIt depends on the gap G (directly affected by), and the force applied by the set screw. By reducing the contact pressure, a higher force can be applied by the set screw, which in turn creates a more stable connection between the insert and the pocket. The relatively high ratio also allows for stress reduction in the notch 444 area of ​​the pin 440.

[0052] Figures 54–59 illustrate a bump-off tool 50 that may be used, for example, to remove a cutting insert of the present invention from a cutting tool shank for replacement, inspection, sharpening, or repair purposes. The bump-off tool 50 includes a cam tip 52 at one end. The body of the bump-off tool 50 may include a substantially circular cross-section, while the cam tip includes a portion having a substantially cylindrical outer surface 54 and a cam surface 56. Although not shown in the figures, the opposite end of the bump-off tool 50 may include a keyed end that can be received into a corresponding recess of a set screw for tightening and loosening the set screw, and the bump-off tool may generally be L-shaped to facilitate the bump-off operation and tightening of the set screw.

[0053] As further shown in Figures 54 to 59, the bump-off hole 428 extends radially through the sidewall of the shank 410 and intersects with the pin receiving hole 420 in the region of the rear end 442 of the pin 440. For example, the rear end 442 may extend at least 10%, or at least 20%, or at least 30%, or at least 40%, within the diameter of the bump-off hole 428, as shown in Figures 44, 55, and 58. The radially extending bump-off hole is at a slight angle from perpendicular to the central longitudinal axis of the shank 410, for example, 5° to 30°, or 15° to 25°, but can alternatively be provided perpendicular. In Figures 55 and 56, the cam tip 52 is aligned outside the bump-off hole 428. In Figures 58 and 59, the cam tip 52 is inserted into the bump-off hole 428 to a position where the cam surface 56 contacts the rear end 442 of the pin 440. When the bump-off tool 50 is rotated around its central longitudinal axis from the indicated position, the cam surface 56 is pressed against the rear end 442, thereby pushing the pin 440 axially in the direction of pulling it out through the pin receiving hole 420. The cam tip 52 thereby exerts sufficient force to remove the cutting insert 430 from the shank 410.

[0054] For the purposes of this detailed description, it should be understood that the present invention may assume various alternatives and step sequences, unless expressly otherwise specified. Furthermore, except in any example of operation, or unless otherwise indicated, all numbers expressing quantities of raw materials used herein and in the claims should be understood in all cases to be modified by the term “approximately.” Accordingly, the numerical parameters described herein and in the appended claims below are approximations that may vary depending on the desired characteristics to be obtained by the present invention, unless otherwise indicated. At a minimum, and not as an attempt to limit the application of the doctrine of equivalents to the claims, each numerical parameter should be interpreted at least in light of the number of significant digits reported and by applying common rounding techniques.

[0055] Although the numerical ranges and parameters described in the broad scope of this invention are approximations, the numerical values ​​described in specific examples are reported as accurately as possible. However, any numerical value inherently includes a certain error that inevitably arises from the standard deviation found in each of those test measurements.

[0056] Furthermore, naturally, any numerical range described herein is intended to include all subranges contained within it. For example, the range "1 to 10" is intended to include all subranges between the stated minimum value of 1 and the stated maximum value of 10 (and all subranges containing the stated minimum value of 1 and the stated maximum value of 10), i.e., all subranges having a minimum value of 1 or greater and a maximum value of 10 or less.

[0057] As used herein, “including,” “containing,” and similar terms are understood to be synonymous with “comprising” in the context of this application, and are therefore open-ended and do not exclude the presence of additional undescribed or unmentioned elements, materials, raw materials, or method steps. As used herein, “consisting of” is understood to be in the context of this application to exclude the presence of any unspecified elements, raw materials, or method steps. As used herein, “essentially consisting of” is understood to be in the context of this application to include specific elements, materials, raw materials, or method steps of the described one that “do not substantially affect the basic and novel properties.”

[0058] In this application, unless otherwise specified, the use of the singular form includes the plural form, and the plural form includes the singular form. For example, this specification refers to a powder composition, a cemented carbide body, and apparent density, but combinations of these components (i.e., multiple such components) may be used.

[0059] Furthermore, in this application, unless otherwise specified, the use of "or" means "and / or," even though "and / or" may be explicitly used in certain cases.

[0060] While specific aspects of the present invention have been described in detail, it will be understood by those skilled in the art that various modifications and alternatives to those details can be developed considering the overall teachings of this disclosure. Accordingly, the specific arrangements disclosed are intended to be illustrative and not limiting with respect to the scope of the present invention, to which the entire scope of the appended claims and any and all equivalents thereof are given.

Claims

1. A modular rotary cutting tool, A shank having a central longitudinal axis and comprising a central pin receiving hole and a front pocket, wherein the front pocket is First and second opposing pocket centering walls, First and second torque transmission pocket drive walls, A pocket floor and a shank, A cutting insert is provided which is removablely attached to the front pocket of the shank, and which has a pin that can be received in the central pin receiving hole of the shank, A modular rotary cutting tool in which the first pocket centering wall defines a plane, the first pocket driving wall defines another plane, the first pocket centering wall plane and the first pocket driving wall plane intersect at a pocket intersection P located on the pocket floor at a pocket wall angle A measured at the pocket intersection P, the pocket wall angle A is greater than 90° and less than 155°, and each of the first and second pocket driving walls is positioned in a plane parallel to the central longitudinal axis of the shank.

2. The modular rotary cutting tool according to claim 1, wherein the pocket wall angle A is 130 to 150°.

3. The pocket intersection point P is located at a pocket offset distance Y measured on the pocket floor, in the direction of the first pocket centering wall plane from the plane where the central longitudinal axis of the shank is located, and the pocket offset distance Y is equal to the diameter D of the shank. Ｓ A modular rotary cutting tool according to claim 1, wherein the amount is 1-20%.

4. The pocket offset distance Y is equal to the shank diameter D. Ｓ A modular rotary cutting tool according to claim 3, wherein the amount is 3 to 15%.

5. The aforementioned front pocket is the pocket centering wall width W measured at the pocket floor. Ｃ , the pocket drive wall width W measured in the aforementioned pocket floor Ｄ The pocket drive wall width W Ｄ However, the pocket centering wall width W Ｃ A modular rotary cutting tool according to claim 1, wherein the amount is more than 10%.

6. The aforementioned pocket drive wall width W Ｄ However, the pocket centering wall width W Ｃ A modular rotary cutting tool according to claim 5, wherein the amount is 25-75%.

7. The modular rotary cutting tool according to claim 1, wherein each of the first and second opposing pocket centering walls is positioned at a seating angle S greater than 0.5° measured from the central longitudinal axis of the shank.

8. The modular rotary cutting tool according to claim 7, wherein the seating angle S is 1 to 4°.

9. The first pocket centering wall has a planar surface area SA Ｃ and the first pocket driving wall has a planar surface area SA Ｄ and the planar surface area SA of the first pocket driving wall Ｄ is 50 to 135% of the planar surface area SA of the first pocket centering wall Ｃ The modular rotary cutting tool according to claim 1

10. The modular rotary cutting tool according to claim 1, wherein the central pin receiving hole has a substantially constant inner diameter along the axial length of the central pin receiving hole.

11. The modular rotary cutting tool according to claim 1, wherein the shank is provided with coolant holes on the front surface of the shank on both sides of the front pocket.

12. The modular rotary cutting tool according to claim 11, wherein the coolant holes are of the same size.

13. The modular rotary cutting tool according to claim 11, wherein the coolant holes are of different sizes.

14. The modular rotary cutting tool according to claim 13, wherein the shank has an angled set screw hole that extends through the side of the shank to the central pin receiving hole, adjacent to the opposing first pocket centering wall and adjacent to one of the first front surfaces of the shank, and one of the coolant holes having a smaller size than another of the coolant holes is located on the first front surface of the shank adjacent to the set screw hole.

15. The cutting insert has a length L measured in the axial direction of the cutting insert. Ｈ A head having a length L Ｐ The head has a pin that extends rearward in the axial direction from the head, and the pin-to-head length ratio L Ｐ : L Ｈ A modular rotary cutting tool according to claim 1, wherein the ratio is greater than 1:

1.

16. The aforementioned pin-to-head length ratio L Ｐ : L Ｈ The modular rotary cutting tool according to claim 15, wherein the ratio is 1.1:1 to 1.6:

1.

17. The pin is at least one side notch located between the front end and the rear end of the pin, with length L Ｔ The pin has at least one side notch defining the tail of the pin having a length L of the tail of the pin. Ｔ However, the total length of the pin is L Ｐ A modular rotary cutting tool according to claim 15, wherein the amount is more than 20%.

18. The length L of the tail of the aforementioned pin Ｔ However, the total length L of the pin Ｐ A modular rotary cutting tool according to claim 17, wherein the amount is 24-33%.

19. The length L of the tail of the aforementioned pin Ｔ However, the diameter D of the pin Ｐ A larger modular rotary cutting tool according to claim 17.

20. Pin tail length to pin diameter ratio L Ｔ : D Ｐ The modular rotary cutting tool according to claim 19, wherein the ratio is 1.0:1 to 1.6:

1.

21. A modular rotary cutting tool according to claim 17, comprising two of the side notches on both sides of the pin, which are spaced 180° apart from each other in the circumferential direction.

22. The aforementioned pin has a diameter D Ｐ The central pin receiving hole has a diameter D of the pin. Ｐ Larger diameter D Ｈ A modular rotary cutting tool according to claim 1, having a clearance gap G provided between the pin and the central pin receiving hole.

23. The modular rotary cutting tool according to claim 22, wherein the clearance gap G is at least 0.002 mm.

24. The modular rotary cutting tool according to claim 23, wherein the clearance gap G is 0.005 to 0.05 mm.

25. A shank for a modular rotary cutting tool, wherein the shank has a central longitudinal axis and comprises a central pin receiving hole and a front pocket, and the front pocket is First and second opposing pocket centering walls, First and second torque transmission pocket drive walls, Equipped with a pocket floor, A shank in which the first pocket centering wall defines a plane, the first pocket driving wall defines another plane, the first pocket centering wall plane and the first pocket driving wall plane intersect at a pocket intersection P located on the pocket floor at a pocket wall angle A measured at the pocket intersection P, the pocket wall angle A is greater than 90° and less than 155°, and each of the first and second pocket driving walls is positioned in a plane parallel to the central longitudinal axis of the shank.

26. A cutting insert for a modular rotary cutting tool having a central longitudinal axis and comprising a head and a pin extending rearward from the head, wherein the head is The first and second insert centering surfaces, The first and second torque transmission insert drive surfaces, It has a rear section and, A cutting insert in which the first insert centering surface defines a plane, the first insert driving surface defines another plane, the first insert centering surface plane and the first insert driving surface plane intersect at an insert intersection P' located on the plane of the rear surface at an insert surface angle A' measured at the insert intersection P', the insert surface angle A' being greater than 90° and less than 155°, and each of the first and second insert driving surfaces is positioned on a plane parallel to the longitudinal axis of the shank.

27. A cutting insert for a modular rotary cutting tool according to claim 26, wherein the insert surface angle A' is 130 to 150°.

28. The insert intersection point P' is located at an insert offset distance Y' measured on the rear surface plane, in the direction of the first insert centering plane from the plane where the central longitudinal axis of the cutting insert is located, and the insert offset distance Y' is equal to the diameter D of the head. Ｈ A cutting insert for a modular rotary cutting tool according to claim 26, wherein the amount is 1 to 20%.

29. The insert offset distance Y' is equal to the diameter D of the head. Ｈ A cutting insert for a modular rotary cutting tool according to claim 28, wherein the amount is 3 to 15%.

30. The first and second insert centering surfaces have insert centering surface widths W' measured on the plane of the rear surface. Ｃ The first and second insert drive surfaces are defined, and the insert drive surface width W' is measured on the plane of the rear surface. Ｄ Define W' Ｄ The insert driving surface having the insert centering surface width W' Ｃ A cutting insert for a modular rotary cutting tool according to claim 26, wherein the amount is at least 10% of the total.

31. The insert drive surface width W' Ｄ However, the insert centering surface width W' Ｃ A cutting insert for a modular rotary cutting tool according to claim 30, wherein the amount is 25-75%.

32. A cutting insert for a modular rotary cutting tool according to claim 26, wherein each of the first and second insert centering surfaces is positioned at a seating angle S of at least 0.5° measured from the central longitudinal axis of the cutting insert.

33. A cutting insert for a modular rotary cutting tool according to claim 32, wherein the seating angle S is 1 to 4°.

34. A cutting insert for a modular rotary cutting tool according to claim 26, wherein the pin has a substantially constant outer diameter along the axial length of the pin.

35. The first insert centering surface has a planar surface area SA' Ｃ The first insert driving surface has a planar surface area SA' Ｄ The insert drive surface has the planar surface area SA' Ｄ However, the planar surface area SA' of the first insert centering surface Ｃ A cutting insert for a modular rotary cutting tool according to claim 26, wherein the amount is 50 to 135%.

36. A cutting insert for a modular rotary cutting tool, The length L measured in the axial direction of the cutting insert Ｈ A head having, Length L Ｐ A pin having the following characteristics extends rearward from the head in the axial direction: Pin-to-head length ratio L Ｐ : L Ｈ However, the cutting insert has a ratio greater than 1:

1.

37. The aforementioned pin-to-head length ratio L Ｐ : L Ｈ However, the cutting insert for a modular rotary cutting tool according to claim 36 is 1.1:1 to 1.6:

1.

38. The pin is at least one side notch located between the front end and the rear end of the pin, with length L Ｔ The pin has at least one side notch defining the tail of the pin, and the length of the tail L Ｔ However, the length L of the aforementioned pin Ｐ A cutting insert for a modular rotary cutting tool according to claim 36, which is more than 20% of the total.

39. The length of the tail mentioned above (LL) Ｔ However, the length L of the aforementioned pin Ｐ A cutting insert for a modular rotary cutting tool according to claim 38, wherein the amount is 24-33%.

40. The length of the tail mentioned above (LL) Ｔ However, the diameter D of the pin Ｐ A larger cutting insert for a modular rotary cutting tool according to claim 38.

41. Pin tail length to pin diameter ratio L Ｔ : D Ｐ However, the cutting insert for a modular rotary cutting tool according to claim 40 is 1.0:1 to 1.6:

1.

42. A cutting insert for a modular rotary cutting tool according to claim 38, comprising two of the side notches on either side of the pin, which are spaced 180° apart from each other in the circumferential direction.

43. A cutting insert for a modular rotary cutting tool having a central longitudinal axis including a cutting head, The first and second insert centering surfaces, The first and second torque transmission insert drive surfaces, It has a rear section and, A cutting insert in which the first insert centering surface defines a plane, the first insert driving surface defines another plane, the first insert centering surface plane and the first insert driving surface plane intersect at an insert intersection P' located on the plane of the rear surface at an insert surface angle A' measured at the insert intersection P', the insert surface angle A' being greater than 90° and less than 155°, and each of the first and second insert driving surfaces is positioned on a plane parallel to the central longitudinal axis of the shank.

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