A grooving tool body having insert receiving slots connected by flexible recesses, and a rotary grooving cutting tool having the grooving tool body.

Abstract

The groove machining tool body includes a disc-shaped cutter portion including opposing forward and rearward cutter portion sides and a cutter portion peripheral surface extending between the forward and rearward cutter portion sides, and a shank portion projecting rearwardly from the rearward cutter portion side. The cutter portion includes N angularly spaced clamping portions, each clamping portion having a peripherally disposed insert receiving slot. The cutter portion further includes a flexible recess recessed into the forward cutter portion side and extending to each of the insert receiving slots. A cutting insert is removably and resiliently clamped into each insert receiving slot to form a rotary groove machining cutting tool.

Description

Technical Field

[0001] The subject matter of the present application generally relates to a rotary groove machining cutting tool having a groove machining tool body with a disc-shaped cutter portion having a plurality of insert receiving pockets arranged circumferentially therein for removably holding cutting inserts, and more particularly to such a groove machining tool body in which the insert receiving pockets elastically clamp the cutting inserts therein.

Background Art

[0002] A rotary groove machining cutting tool may have a groove machining tool body having a disc-shaped cutter portion and a shank portion extending rearwardly from the disc-shaped cutter portion. The disc-shaped cutter portion may be provided with a plurality of insert receiving pockets arranged circumferentially therein for holding cutting inserts. The cutting inserts may be held within the insert receiving pockets by elastic clamping members. An example of such a rotary cutting tool is disclosed, for example, in U.S. Patent Application Publication No. 2019 / 0160555, which discloses a groove machining tool body including a disc-shaped cutter portion and a shank portion projecting rearwardly from the disc-shaped cutter portion. The cutter portion includes a plurality of elastic clamping portions having insert receiving slots arranged peripherally. The disc-shaped cutter portion has a predetermined flexibility that decreases each time a cutting insert is sequentially inserted into each insert receiving slot. In particular, in a cutting tool having a small diameter, the flexibility may decrease to such an extent that the elastic member cannot be displaced sufficiently to insert the last cutting insert.

Summary of the Invention

[0003] According to a first aspect of the subject matter of the present application, there is provided a groove machining tool body having a body central axis defining opposite forward and rearward directions and being rotatable in a rotational direction about the body central axis, the groove machining tool body comprising: a disc-shaped cutter portion, The opposite front cutter section side and rear cutter section side, and the cutter section peripheral surface extending between the front cutter section side and rear cutter section side, N clamp portions that are angularly spaced apart, where N is an integer greater than 1, and each clamp portion has insert receiving slots arranged around the periphery that open to the side surface of the front cutter portion, the side surface of the rear cutter portion, and the peripheral surface of the cutter portion. An elastic clamp member and a lower jaw member facing each other and spaced apart by the insert receiving slot, wherein the elastic clamp member is configured to elastically hold a cutting insert within the insert receiving slot, and a disc-shaped cutter portion comprising: A shank portion that protrudes rearward from the side surface of the rear cutter portion, wherein the shank portion has a shank peripheral surface that extends circumferentially around the central axis of the main body, The cutter portion further comprises a flexible recess that is recessed within the side surface of the front cutter portion and extends to each of the insert receiving slots.

[0004] According to a second aspect of the subject matter of the present application, a rotary groove cutting tool is provided, the rotary groove cutting tool is, The groove machining tool body of the type described above, The system comprises a cutting insert that is removably and elastically clamped in each of the insert receiving slots by one of the elastic clamping members.

[0005] It should be understood that the above is a summary, and that the features described below may be applicable to the subject matter of this application in any combination, for example, any of the following features may be applicable to the grooving tool body and the rotary grooving cutting tool:

[0006] The cutter portion may be divided into N cutter sub-parts. The cutter sub-parts may be spaced apart from each other in the midline of the cutter radial direction that passes through both the flexible recess and the peripheral surface of the cutter portion.

[0007] The flexible recess may exhibit N rotational symmetry about the central axis of the main body.

[0008] The flexible recess may extend in the rearward direction beyond the side surface of the rear cutter portion into the shank portion.

[0009] The flexible recess may intersect the central axis of the main body.

[0010] The flexible recess may be moved into each insert receiving slot at each narrow neck portion.

[0011] The flexible recess may be a blind hole, or it may open only on the side surface of the front cutter portion.

[0012] Each insert receiving slot may be defined by an elongated slot peripheral surface having an end that extends to the peripheral surface of the cutter portion. The flexible recess may comprise a recess base surface connecting the insert receiving slots, and N recess peripheral wall surfaces, each of which extends from the recess base surface to the side surface of the front cutter portion between the slot peripheral surfaces of two circumferentially adjacent insert receiving slots.

[0013] The recessed base surface may be oriented perpendicular to the central axis of the main body. The recessed peripheral wall surface may be oriented parallel to the central axis of the main body.

[0014] The recessed base surface may intersect each of the recessed peripheral wall surfaces with the intersection lines that form the fillet.

[0015] The groove-cutting tool body may further include an annular groove formed at the intersection of the side surface of the rear cutter portion and the surrounding surface of the shank.

[0016] The cutter portion and the shank portion may be integrally formed so that the groove cutting tool body has a single one-piece structure.

[0017] For any predetermined clamp portion, the elastic clamping member may be positioned in front of the lower jaw member in the rotational direction.

[0018] The shank portion may have N angularly spaced front shank recesses that are recessed into the shank peripheral surface adjacent to the cutter portion and open into the shank peripheral surface. The radially inner portion of each insert receiving slot may merge with its respective front shank recess on one side.

[0019] The elastic clamping members of each clamping portion may be adjacent in the axial direction to their respective front shank recesses.

[0020] The shank portion may further comprise N non-concave front shank portions that are alternately arranged in the circumferential direction with the front shank recess and are angularly spaced apart in the circumferential direction, and may be adjacent to the cutter portion in the axial direction.

[0021] In the direction along the central axis of the main body, the virtual radius line extending between the central axis of the main body and the peripheral surface of the shank may define the shank radius of a virtual shank portion circle that is centered on the central axis of the main body and has a shank portion diameter. The cutter portion may define a virtual circumscribed cutter portion circle that is centered on the central axis of the main body and has a cutter portion diameter.

[0022] In the direction along the central axis of the main body, the virtual shank subcircle may intersect all of the insert receiving slots.

[0023] Each insert receiving slot may be defined by an elongated slot peripheral surface having a slot lower jaw contact surface disposed on the lower jaw member. In a direction along the main body central axis, the virtual shank partial circle may intersect the slot lower jaw contact surface.

[0024] The slot peripheral surface may further include a slot clamp member contact surface disposed on the elastic clamp member. In a direction along the main body central axis (B), the slot clamp member contact surface may be disposed radially outside the virtual shank partial circle.

[0025] In an end view of the groove machining tool main body along the main body central axis, the slot lower jaw contact surface and the slot clamp member contact surface may converge toward each other in a direction toward the flexible recess, defining an acute slot contact angle.

[0026] The cutter portion may be divided into N cutter sub - portions. Each clamp portion may include a stop member circumferentially disposed between the elastic clamp member and the lower jaw member. The stop member and the elastic clamp member may be disposed on the same cutter sub - portion.

[0027] N may satisfy the condition of 2 ≦ N ≦ 9. The cutter portion may define a virtual circumscribed cutter portion circle centered on the main body central axis and having a cutter portion diameter. The cutter portion diameter may be 35 mm or less.

[0028] N may satisfy the condition of N = 3. The cutter portion diameter may be approximately 20 mm. <00​​The cutting insert may be longitudinally elongated in the direction defining the longitudinal axis of the insert, and the cutting insert comprises an opposite upper and lower insert surface and an insert peripheral surface extending between the upper and lower insert surfaces, the insert peripheral surface comprising two opposite insert end faces connecting the upper and lower insert surfaces and two opposite insert sides connecting the upper and lower insert surfaces. The cutting insert may also comprise a longitudinal plane of the insert encompassing the longitudinal axis of the insert, passing between the insert sides and intersecting the upper and lower insert surfaces and the opposite insert end faces. The cutting insert may also comprise a cutting portion located at one end of the cutting insert, the cutting portion comprising a cutting edge formed at the intersection of the upper insert surface and one of the two insert end faces. The upper and lower insert surfaces may each comprise an upper contact surface and a lower contact surface. The insert receiving slot may be defined by an elongated slot peripheral surface having a slot lower jaw contact surface disposed on the lower jaw member. The slot peripheral surface may further include a slot clamp member contact surface disposed on the elastic clamp member. The slot clamp member contact surface may contact the insert upper contact surface. The slot lower jaw contact surface may contact the insert lower contact surface.

[0030] The insert end face opposite the cutting portion may further include an insert stop surface that is closer to the upper surface of the insert than to the lower surface of the insert, and the insert stop surface is flat. Each clamp portion may include a stop member circumferentially positioned between the elastic clamp member and the lower jaw member. The cutter portion may be divided into N cutter sub-parts. The stop member and the elastic clamp member may be positioned on the same cutter sub-part. The slot peripheral surface may further include a slot radial stop surface positioned on the stop member. The slot radial stop surface may abut the insert stop surface.

[0031] The cutting insert may have an additional cutting portion so as to include two cutting portions, an effective cutting portion and a non-effective cutting portion, with the two cutting portions formed at both ends of the cutting insert. The upper surface of the insert may include an additional upper contact surface so as to include two upper contact surfaces, an effective insert upper contact surface and a non-effective insert upper contact surface, the effective insert upper contact surface being positioned further away from the effective cutting portion than the upper contact surface of the non-effective insert, and the slot clamp member contact surface contacting the effective insert upper contact surface. The insert end face of the effective cutting portion may include an additional insert stop surface so as to include two insert stop surfaces, an effective insert stop surface and a non-effective insert stop surface, the effective insert stop surface being positioned in the non-effective cutting portion, and the slot radial stop surface contacting the stop surface of the effective insert.

[0032] To better understand this application and to show how it can actually be implemented, please refer to the attached drawings. [Brief explanation of the drawing]

[0033] [Figure 1]This is a front perspective view of a rotary groove cutting tool according to the present invention, in which a cutting insert is elastically clamped within an insert receiving slot. [Figure 2] Figure 1 is an exploded perspective view of a rotary groove machining cutting tool. [Figure 3] Figure 1 is a front view of the groove machining tool body. [Figure 4] Figure 3 is a side view of the groove machining tool body. [Figure 5] This is a detailed view of Figure 3. [Figure 6] Figure 4 is a cross-sectional view of the groove machining tool body along the line VI-VI. [Figure 7] This is a perspective view of the cutting insert relating to the present invention. [Figure 8] Figure 7 is a side view of the cutting insert shown. [Figure 9] Figure 7 is a plan view of the cutting insert shown. [Figure 10] Figure 7 is an end view of the cutting insert. [Figure 11] This is a perspective view of the insertion key. [Figure 12] This is a detailed view of Figure 11. [Figure 13] A similar diagram to Figure 12 shows the cutter portion positioned within the cutter portion receptacle before one of the cutting inserts is fully inserted into one of the insert receiving slots.

[0034] For simplicity and clarity, it should be understood that elements shown in drawings are not necessarily drawn to a consistent scale. For example, the dimensions of some elements may be exaggerated compared to others for clarity, or several physical components may be contained within a single functional block or element. Furthermore, reference numbers may be repeated between drawings to indicate corresponding or similar elements, where appropriate. [Modes for carrying out the invention]

[0035] The following description illustrates various aspects of the subject matter of the present application. For illustrative purposes, specific configurations and details are described in sufficient detail to provide a complete understanding of the subject matter of the present application. However, it will also be apparent to those skilled in the art that the subject matter of the present application can be carried out without the specific configurations and details presented herein.

[0036] First, focusing on Figures 1 and 2, a rotary grooving cutting tool 20 having a tool central axis A, suitable for grooving cutting operations, is shown, illustrating one aspect of the present invention. The rotary grooving cutting tool 20 may exhibit rotational symmetry about the tool central axis A. The rotary grooving cutting tool 20 has a grooving tool body 22, which can typically be made from steel. The rotary grooving cutting tool 20 has a cutting insert 24, which can typically be formed from cemented carbide. The cutting insert 24 is removably attached to the grooving tool body 22.

[0037] As used herein, the term “rotary groove cutting tool” may be replaced with other terms applicable to such cutting tools in the field of metal cutting, such as “grooving cutter,” “grooving milling cutter,” “slitting cutter,” “grooving cutter,” “slot milling cutter,” “grooving milling cutter,” “side milling cutter,” or “disc milling cutter.”

[0038] Here, we refer to Figures 3 and 4, which show another aspect of the subject matter of the present application relating to the groove machining tool body 22. The groove machining tool body 22 has a body central axis B that coincides with the tool central axis A. The body central axis B is in the opposite forward direction D F and rearward direction D R The following is defined: The central axis B of the main body forms a rotation axis around which the groove machining tool body 22 can rotate in the rotational direction R.

[0039] Throughout this description and the claims, the terms “forward” and “rearward” refer to relative positions in the direction of the main body's central axis B, which is downward and upward in Figure 4, respectively. Furthermore, the terms “axial direction” and “radial direction” refer to the tool's central axis B unless otherwise specified.

[0040] As shown in Figure 3, the groove cutting tool body 22 includes a disc-shaped cutter portion 26. The cutter portion 26 includes opposite front cutter portion sides 28a and rear cutter portion sides 28b, and a cutter portion peripheral surface 30 extending between the front cutter portion sides 28a and rear cutter portion sides 28b. As seen in the side view in Figure 4, the rear cutter portion side 28b defines the rear cutter radial plane P', and the front cutter portion side 28a defines the front cutter radial plane P''. The cutter portion peripheral surface 30 extends circumferentially around the body central axis B. The body central axis B intersects the front cutter portion sides 28a and rear cutter portion sides 28b at their central portions. In a front view of the groove cutting tool body 22, in the direction along the body central axis B (i.e., Figure 3), the cutter portion 26 defines a virtual circumscribed cutter portion circle CC centered on the body central axis B and having a cutter portion diameter DC.

[0041] As shown in Figure 4, the cutter portion 26 has a cutter portion width WC in the axial direction measured between the front cutter portion side surface 28a and the rear cutter portion side surface 28b, or more specifically, between the corresponding radial planes P' and P''. According to one embodiment of the subject of the present application, the front cutter portion side surface 28a and the rear cutter portion side surface 28b may be planar and may be perpendicular to the central axis B of the main body.

[0042] The cutter portion 26 includes N clamp portions 32 that are angularly spaced apart around the central axis B of the main body, where N is an integer greater than 1. The N clamp portions 32 may be arranged at the same axial position along the central axis B of the main body in both the forward and backward directions. As shown in Figure 3, each clamp portion 32 may have a chip gullet 33 on the peripheral surface 30 of the cutter portion, and as a result, the cutter portion 26 may not be a perfect circle in front view.

[0043] Referring to Figure 5, each clamp portion 32 includes an elastic clamping member 34 and a lower jaw member 36 that are opposite to each other and spaced apart by an insert receiving slot 38. That is, the insert receiving slot 38 is formed between the elastic clamping member 34 and the lower jaw member 36. In a front view of the grooving tool body 22, the insert receiving slot 38 extends along the insert receiving slot axis C such that the elastic clamping member 34 and the lower jaw member 36 are positioned on both sides of the insert receiving slot axis C. The elastic clamping member 34 is positioned forward in the rotational direction R of the lower jaw member 36 and the insert receiving slot 38. The elastic clamping member 34 is configured to elastically hold the cutting insert 24 within the insert receiving slot 38. The elastic clamping member 34 is elastically displaceable relative to the lower jaw member 36. In other words, each clamp portion 32 is elastic. Note that, as disclosed in U.S. Patents 6,116,823 and 8,388,270, each clamp portion 32 does not have an elastic slot in the rotational direction forward of the elastic clamping member 34. Furthermore, note that each insert receiving slot 38 does not have a threaded hole (for removably attaching a cutting insert to the cutter portion using a threaded clamping screw).

[0044] According to certain embodiments of the subject matter of this application, each clamp portion 32 may include a stop member 39 which may be circumferentially positioned between the elastic clamp member 34 and the lower jaw member 36. Generally speaking, the stop member 39 is radially inward of the elastic clamp member 34 and the lower jaw member 36. The purpose of the stop member 39 will be described later in this specification.

[0045] Referring further to Figure 5, a side view of the clamp portion 32 (i.e., perpendicular to the insert receiving slot axis C) is shown, and the insert receiving slot 38 opens onto the peripheral surface 30 of the cutter portion. Therefore, the insert receiving slot 38 is located peripherally. Returning to Figure 4, the insert receiving slot 38 opens laterally on both sides of the front cutter portion side 28a and the rear cutter portion side 28b. It should be understood that the "later direction" in relation to the insert receiving slot 38 means perpendicular to the insert receiving slot axis C, and therefore generally parallel to the main body central axis B.

[0046] Each insert receiving slot 38 is defined by an elongated slot peripheral surface 40 having an end that extends to the cutter portion peripheral surface 30. Note that the slot peripheral surface 40 is not continuous, as the flexible recess extends to the insert receiving slot 38 (to block the slot peripheral surface 40), as will be described later in this specification. The slot peripheral surface 40 extends between the front cutter portion side surface 28a and the rear cutter portion side surface 28b. The slot peripheral surface 40 includes a slot clamp member contact surface 42 positioned on the elastic clamp member 34 to contact the corresponding surface on the cutting insert 24. The slot peripheral surface 40 includes a slot lower jaw contact surface 44 positioned on the lower jaw member 36 to contact the corresponding surface on the cutting insert 24. The slot peripheral surface 40 includes a slot radial stop surface 46 for positioning the cutting insert 24 at a precise predetermined radial position. The slot radial stop surface 46 faces radially outward. The slot radial stop surface 46 is positioned on the stop member 39. According to a subjective embodiment of the present application, the slot radial stop surface 46 may be circumferentially arranged between the slot clamp member contact surface 42 and the slot lower jaw contact surface 44.

[0047] Referring to Figure 5, the insert receiving slot 38 includes a slot key portion 50 formed in the radially innermost part of the insert receiving slot 38. One purpose of the slot key portion 50 is to function as a stress relief groove (as known in the art). However, the slot key portion 50 has larger dimensions than a typical stress relief groove so that it can also serve to receive the displacement projection of the key when removing the cutting insert 24 from the insert receiving slot 38 (not shown). Furthermore, the slot key portion 50 is positioned further forward in the rotational direction than would normally be required if its purpose were solely as a stress relief groove. For example, most of the insert key portion 50 is positioned on the extension of the slot lower jaw contact surface 44. This allows the displacement projection 51a to contact the end of the cutting insert 24 while being located within the slot key portion 50. The insert receiving slot 38 includes a slot elastic portion 54 for imparting the desired elasticity to the elastic clamping member 34. The slot elastic portion 54 is positioned further forward in the rotational direction than the slot key portion 50.

[0048] As shown in Figures 2 and 4, the grooving tool body 22 includes a shank portion 56 projecting from the side surface 28b of the rear cutter portion. That is, the shank portion 56 projects rearward from the cutter portion 26. The shank portion 56 includes a shank peripheral surface 58 that extends circumferentially around the central axis B of the body. According to certain embodiments of the subject of the present application, the shank portion 56 may be integrally formed with the cutter portion 26 so that the grooving tool body 22 has a single one-piece structure, i.e., the shank portion 56 and the cutter portion 26 are formed from a continuous piece of a single material (e.g., machined). The shank portion 56 may have a substantially cylindrical basic shape. The shank portion 56 may have a male thread 61 for engaging with a female thread of a tool holder (not shown). As best shown in Figure 4, the grooving tool body 22 may include an annular groove 59 formed at the intersection of the side surface 28b of the rear cutter portion and the shank peripheral surface 58.

[0049] Returning to Figures 4 and 6, according to a subjective embodiment of the present application, the shank portion 56 may include N front shank recesses 60 that are recessed into and open out of the shank peripheral surface 58. That is, the front shank recesses 60 may be located periphery and are radially concave near the front end of the shank peripheral surface 58. Each front shank recess 60 may be axially adjacent to the cutter portion 26. In this non-limiting example shown in the drawings, the front shank recesses 60 are located in a partially annular groove 59. The front shank recesses 60 may be angularly spaced apart from each other around the central axis B of the body.

[0050] According to a subjective embodiment of the present application, the shank portion 56 may include N non-concave front shank portions 62 formed by a portion of the non-concave shank peripheral surface 58 (notwithstanding the fact that they may be located within the annular groove 59). The non-concave front shank portions 62 may be arranged peripherally, similar to the front shank recesses 60. The non-concave front shank portions 62 may be located between two circumferentially adjacent front shank recesses 60 and axially adjacent to the cutter portion 26. The number of non-concave front shank portions 62 may be the same as the number of front shank recesses 60. Each non-concave front shank portion 62 may be located between two circumferentially adjacent front shank recesses 60. That is, the front shank recesses 60 and the non-concave front shank portions 62 may be arranged alternately in the circumferential direction. The non-concave front shank portions 62 may be angularly spaced apart from each other around the central axis B of the body.

[0051] As shown in Figure 3, in the direction along the main body central axis B, the virtual radius line extending between the main body central axis B and the shank peripheral surface 58 defines the shank radius RS of a virtual shank partial circle CS that is centered on the main body central axis B and has a shank partial diameter DS. The virtual shank partial circle CS is a circumscribed circle defined by a plurality of angularly spaced non-concave front shank portions 62.

[0052] According to a particular embodiment of the subject matter of the present application, the elastic clamping member 34 of each clamping portion 32 may be axially adjacent to the respective front shank recess 60. That is, the free end of the elastic clamping member 34 is not connected to any portion of the shank portion 56. As shown in Figure 4, the rearward-facing surface 34a of the clamping member 34 faces the front shank recess 60. In the front shank recess 60, the elastic clamping member 34 is cantilevered circumferentially with respect to the non-concave front shank portion 62 in the direction opposite to the rotational direction R. Advantageously, this allows the elastic clamping member 34 to bend slightly when the cutting insert 24 (together with the lower jaw member 36 and the cutting insert 24) contacts the workpiece in order to maintain a firm clamping force on the cutting insert 24. The radially inner portion of the lower jaw member 36 may be connected to one of the non-concave front shank portions 62.

[0053] According to a particular embodiment of the present invention, the radially inner portion of each insert receiving slot 38 merges with the respective front shank recess 60 on one side thereof (i.e., the side of the insert receiving slot 38 that opens to the rear cutter portion side surface 28b).

[0054] According to a particular embodiment of the subject matter of the present application, the virtual shank partial circle CS may intersect all insert receiving slots 38 in a direction along the central axis B of the main body. In particular, for any given clamp portion (32), the virtual shank partial circle CS may intersect the slot lower jaw contact surface 44. The slot clamp member contact surface 42 may be located radially outward of the virtual shank partial circle CS. The slot radial stop surface 46 may be located radially inward of the virtual shank partial circle CS. The slot key portion 50 and the elastic portion 54 may be located radially inward of the shank partial circle CS.

[0055] The cutter portion 26 further includes a flexible recess 64 recessed into the side surface 28a of the front cutter portion. In other words, since the flexible recess 64 is concave with respect to the radial plane P'' of the front cutter, it opens onto the side surface 28a of the front cutter portion. Advantageously, the flexible recess 64 increases the clamping force applied to the cutting insert 24 by the clamping member 34.

[0056] As shown in Figure 4, according to a particular embodiment of the subject matter of the present application, the flexible recess 64 extends in the rearward direction D into the shank portion 56. R It may extend in the rearward direction D. Therefore, the flexible recess 64 is in the rearward direction D. R The flexible recess 64 may extend beyond (i.e., past) the rear cutter radial plane P'. The flexible recess 64 is greater than the cutter portion width WC, in the rear direction D R It has a recess depth D as measured. The flexible recess 64 may be a blind hole. That is, the flexible recess 64 is open only on the side surface 28a of the front cutter portion. The flexible recess 64 may exhibit N-fold rotational symmetry about the central axis B of the main body.

[0057] Referring to Figure 5, according to a subjective embodiment of the present application, the flexible recess 64 may include a recess base surface 66. The recess base surface 66 may connect the insert receiving slots 38. That is, the recess base surface 66 may extend to all of the insert receiving slots 38. The recess base surface 66 may be oriented perpendicular to the central axis B of the body. The flexible recess 64 may include N recess circumferential surfaces 68. Each recess circumferential surface 68 may extend from the recess base surface 66 to the front cutter portion side surface 28a between the slot periphery surfaces 40 of two circumferentially adjacent insert receiving slots 38. The circumferential surface 68 limits the radially inward range of the slot periphery surfaces 40. The recess circumferential surfaces 68 may be oriented parallel to the central axis B of the body. The recess base surface 66 may intersect each of the recess circumferential surfaces 68 at the intersection lines that form the fillet 69.

[0058] According to a particular embodiment of the subject matter of the present application, the flexible recess 64 may be located in the center of the side surface 28a of the front cutter portion. The flexible recess 64 may intersect the main body central axis B. Specifically, the main body central axis B may intersect the recess base surface 66. The recess peripheral wall surface 68 may extend around the main body central axis B.

[0059] As shown in Figure 5, according to one embodiment of the subject of the present application, in an end view of the groove machining tool body 22 along the central axis B of the body, the slot lower jaw contact surface 44 and the slot clamp member contact surface 42 converge toward each other in the direction toward the flexible recess 64, and an acute slot contact angle β may be defined.

[0060] The flexible recesses 64 extend to (i.e., intersect) each of the insert receiving slots 38. In other words, the flexible recesses 64 connect the insert receiving slots 38 to one another. This divides the cutter portion 26 into N cutter sub-parts 70. In a cross-sectional view along the cutter radial median plane P that passes through both the flexible recesses 64 and the cutter portion peripheral surface 30, the cutter sub-parts 70 are spaced apart from each other. According to one embodiment of the subject of the present application, two adjacent cutter sub-parts 70 may be spaced apart from each other by a portion of their respective insert receiving slots 38 and flexible recesses 64. Each cutter sub-part 70 may be sequentially defined circumferentially by a portion of the cutter portion peripheral surface 30, a portion of the slot peripheral surface 40 from the first insert receiving slot 38, one of the recess peripheral wall surfaces 68, and a portion of the slot peripheral surface 40 from the second insert receiving slot 38, and the adjacent first and second insert receiving slots 38.

[0061] Referring to Figure 5, according to one embodiment of the subject matter of the present application, the flexible recess 64 may extend into each insert receiving slot 38 in each narrow neck portion 72. In an end view of the grooving tool body 22 along the central axis B of the body, the straight line L extends between two adjacent cutter sub-portions 70 in the neck portion 72, has a minimum dimension, and defines the boundary between the flexible recess 64 and the receiving slot 38. The slot key portion 50 may be adjacent to the straight line L. As best seen in Figure 3, the flexible recess 64 and the slot key portion 50 have an overall star-shaped polygon with N corner vertices.

[0062] Each cutter sub-part 70 may include a projection hole 31 for receiving the displacement projection 51a of the insertion key 52 when attaching the cutting insert 24 to the cutter part 26, as will be described later.

[0063] It should be noted that each clamp portion 32 spans two adjacent (i.e., different) cutter sub-portions 70. Specifically, for any given clamp portion 32, the clamp member 34 and the lower jaw member 36 are positioned on two adjacent cutter sub-portions 70 and face each other circumferentially. According to one embodiment of the subject of the present application, the stop member 39 and the elastic clamp member 34 may be positioned on the same cutter sub-portion 70.

[0064] Here, we refer to Figures 7 to 10, which show the cutting insert 24. The cutting insert 24 extends longitudinally in the direction defining the insert's longitudinal axis A. The cutting insert 24 includes opposite insert upper surfaces 84 and insert lower surfaces 86, and an insert peripheral surface 88 extending between the insert upper surfaces 84 and insert lower surfaces 86. The insert upper surfaces 84 and insert lower surfaces 86 each include an upper insert contact surface 84a and an insert lower contact surface 86a, respectively, for contacting corresponding surfaces on the insert receiving slot 38. As seen in Figure 8, according to a subjective embodiment of the present application, in a side view of the cutting insert 24 along the insert's lateral axis E, the upper insert contact surface 84a and the insert lower contact surface 86a converge toward each other in a direction away from the cutting edge 96a, which forms an acute insert contact angle α. The insert lower surface 86 may include a straight insert imaginary line L1 parallel to the insert's longitudinal axis A. Referring to Figure 9, the upper insert contact surface 84a and / or the lower insert contact surface 86a may have a prismatic shape that matches the shape of the slot clamp member contact surface 42 and / or the lower slot jaw contact surface 44 in order to prevent displacement of the cutting insert 24 in the lateral direction of the cutting insert 24.

[0065] The insert peripheral surface 88 includes two opposite insert end faces 90 connecting the insert upper surface 84 and the insert lower surface 86. The insert peripheral surface 88 includes two opposite insert side surfaces 92 connecting the insert upper surface 84 and the insert lower surface 86. The insert longitudinal axis A intersects the insert end faces 90, extends between the insert side surfaces 92 (Figure 9), and also extends between the insert upper surface 84 and the insert lower surface 86 (Figure 8). The insert lateral axis E extends perpendicular to the insert longitudinal axis A midway between the insert end faces 90, intersects the two insert side surfaces 92, and defines the insert lateral direction of the cutting insert 24. The insert central axis F extends perpendicular to the insert longitudinal axis A midway between the insert end faces 90, and intersects the insert upper surface 84 and the insert lower surface 86. The insert's central plane M encompasses both the insert's longitudinal axis A and the insert's transverse axis E.

[0066] As shown in Figure 9, the insert longitudinal axis A lies on the insert longitudinal plane P1 which encompasses the insert central axis F, passes through the middle of the insert sides 92, and intersects the end faces 90. The insert central plane P2, which is perpendicular to the insert longitudinal plane P1 and the insert longitudinal axis A, encompasses the insert central axis F and the insert lateral axis E. According to a subjective embodiment of the present application, the cutting insert 24 may have 180° rotational symmetry about the insert central axis F. The cutting insert 24 does not have to be mirror symmetric with respect to the insert central plane P2 or the insert longitudinal plane P1.

[0067] The cutting insert 24 includes a cutting portion 94a located at one end of the cutting insert 24. According to certain embodiments of the subject matter of the present application, the cutting insert 24 may further include one additional cutting portion 94b such that the cutting insert 24 includes two cutting portions 94a, 94b, which consist of an effective cutting portion 94a (which constitutes the cutting portion 94a) and an ineffective cutting portion 94b. The two cutting portions 94a, 94b are located at both ends of the cutting insert 24. In other words, the cutting insert 24 has the same shape at both ends and is indexable by rotating 180° about the insert's central axis F (i.e., the effective cutting portion 94a becomes the ineffective cutting portion 94b, and vice versa). The two cutting portions 94a, 94b may be identical. In the following description, it will be understood that any feature relating to a single cutting portion 94a may also relate to the other cutting portion 94b, if present.

[0068] The cutting portion 94a includes a cutting edge 96a positioned within the cutting portion 94a. Specifically, the cutting edge 96a is formed at the intersection of the insert top surface 84 and one of the two insert end faces 90. A portion of the insert end face 90 adjacent to the cutting edge 96a functions as a flank. Similarly, a portion of the insert top surface 84 adjacent to the cutting edge 96a functions as a rake face. When the cutting insert 24 is removably and elastically clamped within the insert receiving slot 38, the cutting edge 96a of the effective cutting portion 94a is positioned beyond the radial projection of the cutter portion 26 (i.e., beyond the virtual circumscribed cutter portion circle CC). Preferably, such a radial projection is 1 mm or less. As seen in Figure 9, the insert longitudinal plane P1 intersects with the cutting edge 96a; that is, the cutting edge 96a extends on both sides of the insert longitudinal plane P1.

[0069] Each insert side surface 92 bulges outward in the cutting portion 94a. That is, the cutting portion 94a includes two insert lateral extensions 98 that project laterally from both sides of the cutting insert 24 in a direction away from the insert longitudinal plane P1 (i.e., perpendicular to the insert longitudinal plane P1). The cutting edge 96a extends over the two insert lateral extensions 98. When the cutting insert 24, which has the same shape on both sides, is held in the insert receiving slot 38, the wider lateral extension 98 belonging to the ineffective cutting portion 94b, located in the radially inner portion of the insert receiving slot 38, protrudes into the front shank recess 60. Thus, one function of the front shank recess 60 is to accommodate the ineffective lateral extensions 98 and, therefore, to provide clearance for the ineffective lateral extensions 98.

[0070] The insert end face 90 opposite the cutting portion 94a includes an insert concave portion 100 having an insert key surface 102 configured to abut against a displacement projection of a key (not shown) used to remove the cutting insert 24 from the insert receiving slot 38. The insert key surface 102 is closer to the insert bottom surface 86 than to the insert top surface 84. According to one embodiment of the subject of the present application, the insert key surface 102 may be positioned entirely below the insert midline M. In a side view of the cutting insert 24 perpendicular to the insert longitudinal axis A (i.e., Figure 8), the insert key surface 102 may be concavely curved.

[0071] According to a subjective embodiment of the present application, the insert end face 90 opposite the cutting portion 94a may include an insert stop surface 104a for contacting the slot radial stop surface 46. The insert stop surface 104a may be closer to the insert top surface 84 than to the insert bottom surface 86. The insert stop surface 104a may be planar. In a cutting insert where both sides have the same shape as shown in the figure, it is understood that both opposite end faces 90 are provided with a concave portion 100 having a key surface 102. Similarly, the insert end face 90 opposite the ineffective cutting portion 94b includes an insert stop surface 104b, and as a result, the cutting insert 24 includes two insert stop surfaces 104a, 104b, namely, an effective insert stop surface 104a (constituting the insert stop surface 104a) located on the ineffective cutting portion 94b, and an ineffective insert stop surface 104a located on the effective cutting portion 94b.

[0072] Furthermore, in a configuration where both sides of the cutting insert 24 have the same shape, the cutting insert 24 includes an additional cutting edge 96b, and as a result, the cutting insert 24 has two cutting edges: an effective cutting edge 96a (forming the cutting edge 96a) located in the effective cutting portion 96a, and a non-effective cutting edge 96b located in the non-effective cutting portion 94b. The insert upper surface 84 may also include an additional insert upper contact surface 84b, and as a result, the insert upper surface 84 includes two insert upper contact surfaces: an effective insert upper contact surface 84a (forming the insert upper contact surface 84a) and a non-effective insert upper contact surface 84b. The two insert upper contact surfaces 84a and 84b may be axially offset from each other along the insert longitudinal axis A. The effective insert upper contact surface 84a may be located further from the effective cutting portion 94a than the non-effective insert upper contact surface 84b. The upper contact surfaces 84a and 84b of each insert are inclined toward their nearest cutting edges 96a and 96b toward the longitudinal axis A of the insert, that is, toward the insert's central plane M. Therefore, the two upper contact surfaces 84a and 84b of the inserts are inclined toward each other (i.e., non-parallel).

[0073] Returning to Figure 1, in the assembled state of the rotary groove cutting tool 20, the cutting insert 24 is removably and elastically clamped in each of the insert receiving slots 38 by one of the elastic clamping members 34. The slot radial stop surface 46 abuts against the insert stop surface 104a. The slot clamping member contact surface 42 abuts against the insert upper contact surface 84a. The slot lower jaw contact surface 44 abuts against the insert lower contact surface 86a. As is known, the slot clamping member contact surface 42 and / or the slot lower jaw contact surface 44 may include two or more spaced-apart contact sub-surfaces, and therefore each may not be literally a single contact surface. In this non-limiting example shown in the drawing (e.g., Figure 3), the slot lower jaw contact surface 44 includes two longitudinally spaced contact sub-surfaces in a configuration in which both sides of the cutting insert 24 have the same shape. The slot clamp member contact surface 42 contacts the upper insert contact surface 84a, which is furthest from the effective cutting edge 96a.

[0074] Referring to Figures 11 and 12, inserting the cutting insert 24 into the insert receiving slot 38 may be achieved using an insertion key 52. ​​The insertion key 52 has a key handle 74. The insertion key 52 has a key head portion 76 connected to the key handle 74 and located at the opposite end of the insertion key 52. ​​The key handle 74 is rotatable relative to the key head portion 76 about the key rotation axis K. The key head portion 76 includes a key base surface 78. The insertion key 52 has two opposing fixed retaining arms 80 protruding from the key base surface 78. The insertion key 52 also has displaceable displacement projections 51a and fixed insertion arms 51b that protrude from the key base surface 78 and face each other. The two opposing key retaining arms 80, the displacement projections 51a and the insertion arms 51b are all spaced apart from each other to form a cutter portion receptacle 82.

[0075] Referring to Figure 13, the cutting insert 24 is loosely positioned in the insert receiving slot 38. The cutter portion 26 is inserted into the cutter portion receptacle 82 with the insertion arm 51b positioned next to the insert end face 90 in the cutting portion 94a which will soon become active, and with the displacement projection 51a inserted into the projection hole 31 located on the distal cutter sub-portion 70 of the insert receiving slot 38 into which the cutting insert 24 is inserted. The front cutting portion side surface 28a and the key base surface 78 face each other. The two fixed arms 80 engage with the cutter portion 26 around them. Rotation of the key handle 74 around the key rotation axis K displaces the displacement projection 51a toward the insertion arm 51b, resulting in a decrease in the projection distance PD between the displacement projection 51a and the insertion arm 51b. The insertion arm 51b first contacts the cutting insert 24, and then pushes the cutting insert 24 into the insert receiving slot 38 until the cutting insert 24 is fully inserted (i.e., the slot radial stop surface 46 abuts against the insert stop surface 104a) and is firmly clamped by the clamping member 34.

[0076] It should be noted that the flexible recess 64 advantageously provides sufficient flexibility to the clamp member 34, and as a result, the clamp member 34 can be displaced sufficiently so that all cutting inserts 24 can be inserted into their respective insert receiving slots 38, while the clamp member 34 has sufficient rigidity to firmly clamp the cutting inserts 24. This advantage is particularly relevant to small diameter tools (e.g., when the cutter portion diameter DC is 35 mm or less). In such small diameter cutting tools, the number of insert receiving slots is limited, and N is between 2 and 9 (i.e., N satisfies the condition 2 ≤ N ≤ 9). In particular, N may be equal to 3 (i.e., N=3), and the cutter portion diameter DC may be about 20 mm. However, the present invention is not limited to such ranges and / or values.

[0077] While the subject matter of this application has been described in some detail, please understand that various changes and modifications may be made without departing from the spirit or scope of the claimed invention.

Claims

1. The groove cutting tool body (22) is located in the opposite forward direction (D Ｆ ) and rearward direction (D Ｒ The main body central axis (B) is defined, and the groove machining tool body (22) is rotatable in the rotational direction (R) around the main body central axis (B), and the groove machining tool body (22) is, A disc-shaped cutter portion (26), The opposite front cutter portion side surface (28a) and rear cutter portion side surface (28b), and the cutter portion peripheral surface (30) extending between the front cutter portion side surface (28a) and the rear cutter portion side surface (28b), N clamp portions (32) that are angularly spaced apart, where N is an integer greater than 1, and each clamp portion (32) has a periphery-arranged insert receiving slot (38) that opens to the side surface (28a) of the front cutter portion, the side surface (28b) of the rear cutter portion, and the peripheral surface (30) of the cutter portion, A disc-shaped cutter portion (26) comprising an elastic clamp member (34) and a lower jaw member (36) facing each other and separated by the insert receiving slot (38), wherein the elastic clamp member (34) is configured to elastically hold the cutting insert (38) within the insert receiving slot (38), and the elastic clamp member (34) and the lower jaw member (36), A shank portion (56) protruding rearward from the side surface (28b) of the rear cutter portion, wherein the shank portion (56) has a shank peripheral surface (58) extending circumferentially around the central axis (B) of the main body, The cutter portion (26) further comprises a flexible recess (64) that is recessed into the side surface (28a) of the front cutter portion and extends to each of the insert receiving slots (38), The groove cutting tool body (22) has a one-piece structure, in which the cutter portion (26) and the shank portion (56) are integrally formed.

2. The cutter portion (26) is divided into N cutter sub-parts (70), The groove cutting tool body (22) according to claim 1, wherein the cutter sub-portions (70) are spaced apart from each other in the cutter radial median plane (P) that passes through both the flexible recess (64) and the cutter portion peripheral surface (30).

3. The groove machining tool body (22) according to claim 1, wherein the flexible recess (64) exhibits N rotational symmetry about the central axis (B) of the body.

4. The flexible recess (64) is in the rearward direction (D Ｒ The groove cutting tool body (22) according to claim 1, which extends beyond the side surface (28b) of the rear cutter portion to into the shank portion (56).

5. The groove machining tool body (22) according to claim 1, wherein the flexible recess (64) intersects the central axis (B) of the body.

6. The groove cutting tool body (22) according to claim 1, wherein the flexible recesses (64) transition into each insert receiving slot (38) at their respective narrow neck portions (72).

7. The groove machining tool body (22) according to claim 1, wherein the flexible recess (64) is a blind hole and opens only on the side surface (28a) of the front cutter portion.

8. Each insert receiving slot (38) is defined by an elongated slot peripheral surface (40) having an end that extends to the cutter portion peripheral surface (30), The aforementioned flexible recess (64) is The recessed base surface (66) connecting the insert receiving slot (38), The groove machining tool body (22) according to claim 1, comprising N recessed circumferential wall surfaces (68), each of which extends from the recessed base surface (66) to the front cutter portion side surface (28a) between the slot peripheral surfaces (40) of two circumferentially adjacent insert receiving slots (38).

9. The groove cutting tool body (22) according to claim 1, wherein, with respect to any predetermined clamp portion (32), the elastic clamp member (34) is arranged in front of the lower jaw member (36) in the rotational direction (R).

10. In the direction along the central axis (B) of the main body, The virtual radius line extending between the main body central axis (B) and the shank peripheral surface (58) defines the shank radius (RS) of a virtual shank partial circle (CS) centered on the main body central axis (B) and having a shank partial diameter (DS). The groove machining tool body (22) according to claim 1, wherein the cutter portion (26) defines a virtual circumscribed cutter portion circle (CC) centered on the central axis (B) of the main body and having a cutter portion diameter (DC).

11. Each insert receiving slot (38) is defined by an elongated slot peripheral surface (40) having a slot lower jaw contact surface (44) positioned on the lower jaw member (36), The groove machining tool body (22) according to claim 10, wherein the virtual shank partial circle (CS) intersects the slot lower jaw contact surface (44) in a direction along the central axis (B) of the main body.

12. The slot peripheral surface (40) further comprises a slot clamp member contact surface (42) disposed on the elastic clamp member (34), The groove machining tool body (22) according to claim 11, wherein the slot clamp member contact surface (42) is positioned radially outward of the virtual shank partial circle (CS) in a direction along the central axis (B) of the main body.

13. In an end-face view of the groove machining tool body (22) along the central axis (B) of the body, the slot lower jaw contact surface (44) and the slot clamp member contact surface (42) converge toward the flexible recess (64), defining an acute slot contact angle (β), as described in claim 12.

14. The cutter portion (26) is divided into N cutter sub-parts (70), Each clamp portion (32) is provided with a stop member (39) positioned circumferentially between the elastic clamp member (34) and the lower jaw member (36), The groove cutting tool body (22) according to claim 1, wherein the stop member (39) and the elastic clamp member (34) are arranged on the same cutter sub-part (70).

15. N satisfies the condition 2 ≤ N ≤ 9, The cutter portion (26) defines a virtual circumscribed cutter portion circle (CC) centered on the main body's central axis (B) and having a cutter portion diameter (DC), The groove cutting tool body (22) according to claim 1, wherein the diameter of the cutter portion (DC) is 35 mm or less.

16. The slot tool body (22) described in claim 1, A rotary groove cutting tool (20) comprising: a cutting insert (24) that is removably and elastically clamped in each of the insert receiving slots (38) by one of the elastic clamping members (34); and a rotary groove cutting tool (20).

17. The cutting insert (24) is elongated in the longitudinal direction in the direction that defines the longitudinal axis (A) of the insert, and the cutting insert (24) An insert upper surface (84) and insert lower surface (86) opposite to each other, and an insert outer peripheral surface (88) extending between the insert upper surface (84) and the insert lower surface (86), wherein the insert outer peripheral surface (88) comprises two opposite insert end faces (90) connecting the insert upper surface (84) and the insert lower surface (86), and two opposite insert side faces (92) connecting the insert upper surface (84) and the insert lower surface (86), and the insert upper surface (84) and insert lower surface (86) and the insert outer peripheral surface (88), A plane (P1) in the longitudinal direction of the insert encompasses the longitudinal axis (A) of the insert, passes between the side surfaces (92) of the insert, intersects the upper surface (84) and the lower surface (86) of the insert, and also intersects the opposite end surface (90) of the insert, A cutting portion (94a) is provided at one end of the cutting insert (24), wherein the cutting portion (94a) has a cutting edge (96a) formed at the intersection of the upper surface (84) of the insert and one of the two end faces (90) of the insert, The upper surface (84) and lower surface (86) of the insert are provided with an upper contact surface (84a) and a lower contact surface (86a), respectively. The insert receiving slot (38) is defined by an elongated slot peripheral surface (40) having a slot lower jaw contact surface (44) positioned on the lower jaw member (36), The slot peripheral surface (40) further comprises a slot clamp member contact surface (42) disposed on the elastic clamp member (34), The slot clamp member contact surface (42) contacts the insert upper contact surface (84a), The rotary groove machining cutting tool (20) according to claim 16, wherein the slot lower jaw contact surface (44) contacts the insert lower contact surface (86a).

18. The insert end face (90) opposite to the cutting portion (94a) further comprises an insert stop surface (104a) that is closer to the insert upper surface (84) than to the insert lower surface (86), and the insert stop surface (104a) is flat. Each clamp portion (32) is provided with a stop member (39) positioned circumferentially between the elastic clamp member (34) and the lower jaw member (36), The cutter portion (26) is divided into N cutter sub-parts (70), The stop member (39) and the elastic clamp member (34) are arranged on the same cutter sub-part (70). The slot peripheral surface (40) further comprises a slot radial stop surface (46) disposed on the stop member (39), The rotary groove cutting tool (20) according to claim 17, wherein the slot radial stop surface (46) abuts against the insert stop surface (104a).

19. The cutting insert (24) includes an additional cutting portion (94b) such that the cutting insert (24) includes two cutting portions, an effective cutting portion (94a) and a non-effective cutting portion (94b), and the two cutting portions (94a, 94b) are formed at both ends of the cutting insert (24). The insert upper surface (84) includes an additional insert upper contact surface (84b) such that the insert upper surface (84) includes two insert upper contact surfaces, an effective insert upper contact surface (84a) and a non-effective insert upper contact surface (84b), the effective insert upper contact surface (84a) is located further away from the non-effective insert upper contact surface (84b), and the slot clamp member contact surface (42) contacts the effective insert upper contact surface (84a). The rotary groove cutting tool (20) according to claim 18, wherein the insert end face (90) of the effective cutting portion (94a) includes an additional insert stop face (104b) such that the cutting insert (24) includes two insert stop faces, an effective insert stop face (104a) and a non-effective insert stop face (104b), the effective insert stop face (104a) is positioned in the non-effective cutting portion (94b), and the slot radial stop face (46) abuts against the effective insert stop face (104a).

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