Morse taper rotary cutting tool with interchangeable cutting head, tool holder, and fastening member

Abstract

The cutting tool includes a replaceable cutting head, which includes a front cutting portion, a rear assembly portion, and a head through-hole extending through the front cutting portion and the rear assembly portion. The assembly portion includes a male coupling member, which includes a conical head contact surface. The cutting tool includes a female coupling member, which includes a conical front holder contact surface and a female threaded portion. The cutting tool includes a fastening member having a male threaded portion. When the cutting tool is in the locked position, the male coupling member is removably held within the female coupling member by the fastening member located within the head through-hole, and the fastening member's male threaded portion and the holder's female threaded portion screw into each other. The head contact surface contacts the front holder contact surface, thereby creating a Morse tapered connection between the male coupling member and the female coupling member.

Description

[Technical Field]

[0001] The subject matter of this application relates to a rotary cutting tool of the type in which an interchangeable cutting head having a male coupling member is removably held in a female coupling member of a tool holder by a friction fitting coupling mechanism. More specifically, the subject matter of this application relates to such a tool in which the coupling mechanism has a machine taper, and more specifically, the machine taper is of the Morse taper type, and even more specifically, the coupling mechanism has a further fastening member. [Background technology]

[0002] A rotary cutting tool may have a coupling mechanism that releasably holds an interchangeable cutting head within a tool holder by fastening members. An example of such a rotary cutting tool is disclosed in US7,431,543, which shows a machine reamer, comprising a base and an interchangeable reamer head assembled on the base. The reamer head is clamped by a tension rod at a conical shoulder into a complementary surface insert seat of the base to provide the required coaxiality. The tension rod has a complementary polygonal section that extends through an axial polygonal opening of the interchangeable cutting head to ensure good rotary gripping.

[0003] Another example is US7,004,692, which shows a cutting head, a threaded member, and a tool shank. The threaded member screws into the tool shank. The cutting head is centered relative to the tool shank, and the conical portion of the cutting head is located within the forward conical portion of the tool shank. The cutting head has a head hole with multiple locking wings, and the threaded member has multiple clamping wings. Rotational coupling between the cutting head and the threaded member is achieved by the engagement of the clamping wings of the threaded member with a stopper, the stopper protruding axially forward from the locking surface of the locking wings. That is, torque is transmitted from the tool shank to the head via the clamping wings on the threaded member.

[0004] Other cutting tools may feature friction-fitting coupling mechanisms of the Morse taper type. An example of such a rotary cutting tool is disclosed, for example, in US2,407,471A, which shows a rotary tool having an adapter with a tool-receiving socket and a tapered shank for the tool-receiving socket. The tapered shank terminates with a tang that engages with a drift hole, and the faces of the shank prevent rotation of the tool within the socket. Typically, a hammer is used to strike the tapered shank into the tool-receiving socket until the tapered shank and the tool-receiving socket are frictionally held. [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] One of the subject matter of this application is to provide a coupling mechanism for an interchangeable cutting head within a tool holder, which is particularly suitable for rotary cutting tools having a smaller cutting outer diameter. [Means for solving the problem]

[0006] According to a first aspect of the subject matter of this application, an interchangeable cutting head for rotary cutting is provided, the interchangeable cutting head having a longitudinal axis defining opposite forward and backward directions, and opposite forward and backward rotation directions, the forward rotation direction being the cutting direction, and the interchangeable cutting head, A front portion that forms the cutting portion and a rear portion that forms the assembly portion, The opposing front and rear surfaces of the head, and the outer circumferential surface of the head extending between the front and rear surfaces of the head, wherein the front surface of the head is located in the cutting portion, and the rear surface of the head is located in the assembly portion, the opposing front and rear surfaces of the head, and the outer circumferential surface of the head, A head through-hole, comprising an outer circumferential surface of the through-hole that extends around the central axis of the through-hole and intersects the front surface of the head and the rear surface of the head. Equipped with, The assembly portion includes a male coupling member that protrudes rearward from the head base surface, and the head base surface extends transversely with respect to the longitudinal axis of the head, defining a boundary between the cutting portion and the assembly portion. The male coupling member has a conical head contact surface configured for a Morse tapered coupling mechanism.

[0007] In a further aspect of the subject matter of the present application, a tool holder is also provided, the tool holder having a longitudinal axis of the holder and comprising a female coupling member extending rearward from the front surface of the holder, the front surface of the holder extending transversely with respect to the longitudinal axis of the holder, and the female coupling member, A conical front holder contact surface configured for a Morse taper coupling mechanism, The female thread portion of the holder located behind the front holder contact surface and It is equipped with.

[0008] According to a further aspect of the subject matter of this application, a rotary cutting tool is also provided, and the rotary cutting tool is, The above-mentioned types of interchangeable cutting heads, The above-mentioned types of tool holders, A fastening member that is elongated along the longitudinal axis of the fastening member and The fastening member comprises a fastening member tightening portion and a fastening member shank portion that is axially offset from the fastening member tightening portion along the longitudinal axis of the fastening member, the fastening member tightening portion has a tightening surface that is tapered inward in the direction from the fastening member tightening portion toward the fastening member shank portion, and the fastening member shank portion has a fastening member male thread portion. The rotary cutting tool is adjustable between a released position and a locked position, and in the locked position, The male coupling member is removably held within the female coupling member by a fastening member located within the head through-hole, and the male threaded portion of the fastening member and the female threaded portion of the holder are screwed together. The head contact surface contacts the front holder contact surface, thereby creating a Morse tapered connection between the male and female coupling members.

[0009] The above is a summary, and the features described below may be applicable to the subject matter of the present application in any combination. For example, it should be understood that any of the following features may be applicable to an indexable cutting head, a tool holder, or a rotary cutting tool.

[0010] The head abutment surface may be tapered inward at a certain head cone angle in the rearward direction. The head cone angle may be within the range of 2.8° ≤ 2α ≤ 3.16°.

[0011] In particular, the head cone angle may be within the range of 2.9° ≤ 2α ≤ 3.06°.

[0012] The head through-hole may include a clamping portion receiving portion and a shank portion receiving portion axially offset from the clamping portion receiving portion. The shank portion receiving portion extends between the clamping portion receiving portion and the rear face of the head. The clamping portion receiving portion may include at least one bearing surface tapered inward in the rearward direction.

[0013] The clamping portion receiving portion may extend to the front face of the head.

[0014] The head through-hole may include at least two radially extending through-hole expansion portions extending from the rear face of the head to the clamping portion receiving portion.

[0015] The clamping portion receiving portion may include at least two clamping wing pockets. Each clamping wing pocket merges with a respective through-hole radial expansion portion and is in the forward rotation direction from the through-hole radial expansion portion about the longitudinal axis of the head. The clamping portion receiving portion may include at least two bearing surfaces, each of which is formed from a part of a respective clamping wing pocket.

[0016] The head through-hole may include exactly two through-hole expansion portions diametrically opposed to each other about the central axis of the through-hole. The clamping portion receiving portion may include exactly two clamping wing pockets diametrically opposed to each other about the central axis of the through-hole.

[0017] The head contact surface has a certain head cone height, measured along the longitudinal axis of the head. The head contact surface has a certain maximum head cone diameter. The head cone height may exceed the maximum head cone diameter.

[0018] In particular, the head cone height can exceed 1.5 times the maximum head cone diameter.

[0019] The assembly portion has a certain assembly portion height, measured between the rear surface of the head and the base surface of the head along the longitudinal axis of the head. The head cone height may exceed 80% of the assembly portion height.

[0020] The cutting portion has a certain cutting portion height, measured between the front surface of the head and the base surface of the head in a direction along the longitudinal axis of the head. The assembly portion height may exceed the cutting portion height.

[0021] The height of the assembly portion can exceed twice the height of the cutting portion.

[0022] The male coupling member may lack a male threaded portion, a tang, and a square drive portion.

[0023] At least one support surface may be positioned entirely in front of the head base surface.

[0024] The front holder contact surface may be tapered inward toward the holder's internal thread at a certain holder cone angle. The holder cone angle may be within the range of 2.8° ≤ 2γ ≤ 3.16°.

[0025] In particular, the holder cone angle can be within the range of 2.9° ≤ 2γ ≤ 3.06°.

[0026] The tool holder may have an outer circumferential surface that extends around the longitudinal axis of the holder and defines the boundary of the front surface of the holder. The tool holder may also have a coolant passage that opens onto the outer circumferential surface of the holder.

[0027] The holder's outer circumferential surface comprises a front holder outer circumferential surface, a rear holder outer circumferential surface, and an intermediate holder outer circumferential surface extending between the front holder outer circumferential surface and the rear holder outer circumferential surface. The front holder outer circumferential surface is closer to the front of the holder than both the intermediate holder outer circumferential surface and the rear holder outer circumferential surface. The front holder outer circumferential surface has a diameter that may be less than the diameter of the rear holder outer circumferential surface. The coolant passage may open at least partially to the intermediate holder outer circumferential surface.

[0028] The tool holder may further include a rear support portion, the rear support portion having a rear holder contact surface that extends around the longitudinal axis of the holder.

[0029] The front holder contact surface has a certain holder cone height, measured along the longitudinal axis of the holder. The front holder contact surface has a certain maximum holder cone diameter. The holder cone height may exceed the maximum holder cone diameter.

[0030] In particular, the holder cone height can exceed 1.5 times the maximum holder cone diameter.

[0031] The holder's internal threaded portion has a certain internal threaded length, measured along the longitudinal axis of the holder. The internal threaded length may be less than the holder's cone height.

[0032] In the locked position, at least one clamping surface may contact at least one support surface.

[0033] The fastening members are formed as a single, integrated structure.

[0034] In the locked position, the head base surface can be spaced apart from the front surface of the holder.

[0035] A rotary cutting tool can be a reamer.

[0036] The head through-hole may comprise at least two through-hole expansions extending from the rear surface of the head to the clamping portion receiving portion. The clamping portion receiving portion may comprise at least two clamping wing pockets, each of which merges with its respective through-hole radial expansion and rotates forward from the through-hole radial expansion around the longitudinal axis of the head. The clamping portion receiving portion may comprise at least two support surfaces, each of which is formed from a portion of its respective clamping wing pocket. The fastening member clamping portion may comprise at least two fastening member clamping wings extending radially outward with respect to the longitudinal axis of the fastening member. The fastening member clamping portion may comprise at least two clamping surfaces, each of which is formed from a portion of its respective fastening member clamping wing. Each of the at least two fastening member clamping wings may be located within its respective clamping wing pocket. In the locked position, each of the at least two clamping surfaces may abut against its respective support surface.

[0037] Each of at least two clamping wing pockets may have a pocket side, which extends radially with respect to the holder's longitudinal axis and faces backward. Each of at least two fastening member clamping wings may have two opposite wing sides extending radially with respect to the fastening member's longitudinal axis. In the locked position, for any and all fastening member clamping wings, one of the two opposite wing sides may face forward. Also, in the locked position, each pocket side of at least two clamping wing pockets facing backward may abut against the respective wing side facing forward.

[0038] The fastening member shank portion may include an elongated fastening member neck portion, which extends between the fastening member tightening portion and the fastening member threaded portion. The fastening member neck portion has a certain fastening member neck height, measured along the longitudinal axis of the fastening member. The fastening member threaded portion has a certain threaded portion length, measured along the longitudinal axis of the fastening member. The fastening member neck height may exceed the threaded portion length.

[0039] The head through-hole may comprise two strictly diametrically opposed through-hole expansions around the central axis of the through-hole. The clamping portion receiving portion may comprise two strictly diametrically opposed clamping wing pockets around the central axis of the through-hole. The fastening member clamping portion may comprise two strictly diametrically opposed fastening member clamping wings around the longitudinal axis of the fastening member.

[0040] The tool holder may further comprise a rear support portion, the rear support portion having a rear holder contact surface extending around the longitudinal axis of the holder. The fastening member shank portion may comprise at least two fastening member elastic pins spaced at an angle around the longitudinal axis of the fastening member, the at least two fastening member elastic pins being radially flexible and located further from the fastening member tightening portion than the fastening member male thread portion. In the locked position, the at least two fastening member elastic pins can be elastically deformed relative to the rear holder contact surface.

[0041] To better understand this application and to demonstrate how it can be actually implemented, please refer to the attached drawings. [Brief explanation of the drawing]

[0042] [Figure 1] This is a perspective view of a rotary cutting tool. [Figure 2] Figure 1 is an exploded perspective view of the rotary cutting tool shown. [Figure 3] Figures 1 and 2 are perspective views of the interchangeable cutting heads. [Figure 4] Figure 3 is a side view of the replaceable cutting head, showing the hidden head through-hole. [Figure 5] Figure 4 is a cross-sectional view of the replaceable cutting head taken along line VV. [Figure 6] Figure 3 is a rear view of the interchangeable cutting head. [Figure 7] Figure 3 is a front view of the interchangeable cutting head. [Figure 8] This is a cross-sectional view of the interchangeable cutting head taken along line VIII-VIII in Figure 7. [Figure 9] Figure 7 shows a cross-sectional view of the interchangeable cutting head taken along line IX-IX. [Figure 10] Figures 1 and 2 are top views of the tool holder. [Figure 11] Figure 10 shows a cross-sectional view of the tool holder taken along line XI-XI. [Figure 12] This is a detailed view of Figure 11. [Figure 13] Figures 1 and 2 are perspective views of the fastening members. [Figure 14] Figure 13 is a side view of the fastening member. [Figure 15] Figure 13 is a top view of the fastening member. [Figure 16] Figure 13 is a bottom view of the fastening member. [Figure 17] Figures 1 and 2 show detailed longitudinal cross-sectional views of the rotary cutting tool when it is in the locked position. [Figure 18] This is a radial cross-sectional view of the rotary cutting tool shown in Figures 1 and 2, taken along the line XVIII-XVIII in Figure 17. [Figure 19] This is a radial cross-sectional view of the rotary cutting tool shown in Figures 1 and 2, taken along the line XIX-XIX in Figure 17. [Modes for carrying out the invention]

[0043] For the sake of brevity and clarity, please note that the elements in the illustrations are not necessarily drawn to a consistent scale. For example, the dimensions of some elements may be exaggerated relative to others for clarity, or some physical components may be included within a single functional block or element. Where deemed appropriate, reference numbers may be repeated between drawings to indicate corresponding or similar elements.

[0044] In the following description, various aspects of the subject matter of the present application will be explained. For the sake of explanation, specific configurations and details will be shown in sufficient detail to provide a complete understanding of the subject matter of the present application. However, it will 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.

[0045] First, please turn your attention to Figures 1 and 2, which show a type of rotary cutting tool 20 used in a reaming operation according to some embodiments of the subject matter of the present application. The rotary cutting tool 20 includes a replaceable cutting head 22 having a longitudinal axis A, the replaceable cutting head 22 rotates around the longitudinal axis A, and the longitudinal axis A rotates in the opposite forward direction R. F and the direction R after rotation R Define the direction of rotation R. F This is the cutting direction. The longitudinal axis A of the head is opposite to the forward direction D. F and rearward direction D R It is also defined. In other words, the longitudinal axis A of the head is defined in the forward direction D. F D in the rear direction R The interchangeable cutting head 22 may typically be made from cemented carbide. The rotary cutting tool 20 also includes a tool holder 24. The tool holder 24 may typically be made from steel. The interchangeable cutting head 22 may be removably held within the tool holder 24 by a friction fitting coupling mechanism and fastening members. Such couplings may potentially be advantageous for other types of rotary cutting operations besides those described above, such as milling or drilling.

[0046] The terms “forward” and “rearward” should be understood throughout this specification and the claims to refer to the relative positions to the left and right, respectively, in the direction of the longitudinal axis A of the head, as shown in Figures 4, 8, and 9. The terms “rotating forward” and “rotating backward” should be understood throughout this specification and the claims to refer to the relative positions to the counterclockwise and clockwise, respectively, in the direction of rotation around the longitudinal axis A of the head, as shown in Figures 5 and 7.

[0047] Next, refer to FIGS. 3 to 9. The replaceable cutting head 22 has a front portion forming a cutting portion 26 and a rear portion forming an assembly portion 28. That is, the cutting portion 26 is disposed forward, and the assembly portion 28 is disposed rearward. According to some embodiments of the subject matter of the present application, the cutting portion 26 may be joined to the assembly portion 28.

[0048] The replaceable cutting head 22 includes an opposite head front surface 56 and a head rear surface 58, and a head outer peripheral surface 60 extending between the head front surface 56 and the head rear surface 58. The head front surface 56 is located in the cutting portion 26 and generally faces forward in the direction D F and faces. The head rear surface 58 is located in the assembly portion 28 and generally faces rearward in the direction D R and faces. The head outer peripheral surface 60 extends around the head longitudinal axis A. According to some embodiments of the subject matter of the present application, the head rear surface 58 may be perpendicular to the head longitudinal axis A.

[0049] According to some embodiments of the subject matter of the present application, the replaceable cutting head 22 may be integrally formed to have a single integral structure. This provides the advantage that the replaceable cutting head 22 does not have a removable cutting insert (not shown). Such a removable cutting insert needs to be periodically replaced, and this replacement can be a time-consuming procedure. For example, a screwed-in screw (not shown) that may be used to releasably hold the removable cutting insert to the replaceable cutting head 22 may also be misplaced and / or lost during the replacement operation.

[0050] Referring to FIG. 3, the cutting portion 26 includes at least one outer peripheral cutting edge 30. In this non-limiting example shown, there may be exactly six outer peripheral cutting edges. The outer peripheral cutting edge 30 defines a cutting outer diameter O. The cutting outer diameter O may be 7.6 mm or less. Each outer peripheral cutting edge 30 is formed at the intersection of an outer peripheral relief surface 32 and an outer peripheral rake surface 34. The outer peripheral relief surface 32 is located behind the rotation of the outer peripheral cutting edge 30 (i.e., behind the outer peripheral cutting edge 30), and the outer peripheral rake surface 34 is located in front of the rotation of the outer peripheral cutting edge 30 (i.e., in front of the outer peripheral cutting edge 30). Generally, the outer peripheral rake surface 34 faces in the pre-rotation forward direction RF The orientation of the outer peripheral cutting edge 30 (as well as the outer peripheral rake face 34 and outer peripheral relief face 32) enables the performance of the metal cutting operation. According to some embodiments of the subject matter of the present application, the cutting portion 26 may include at least one groove 36 for ejecting chips (not shown) generated during the cutting operation. One groove 36 is associated with each outer peripheral cutting edge 30. As shown in the figure, the cutting portion 26 includes a plurality of cutting sections 31 arranged in the circumferential direction, each cutting section 31 facing the forward rotation direction R F The outer periphery relief surface 32, the cutting edge 30, the rake face 34, and the groove 36 are included in succession.

[0051] Referring particularly to Figure 4, the assembly portion 28 includes a male coupling member 38 projecting rearward from the head base surface 40. The head base surface 40 extends transversely with respect to the head longitudinal axis A and defines the boundary between the cutting portion 26 and the assembly portion 28. That is, the cutting portion 26 is formed in front of the head base surface 40, and the assembly portion 28 is formed behind the head base surface 40. According to some embodiments of the subject of this application, the male coupling member 38 may be rigid. The head base surface 40 may be perpendicular to the head longitudinal axis A. The male coupling member 38 is in the rearward direction D R Note that the boundary is defined by the rear surface 58 of the head. The male coupling member 38 may not have a male threaded portion, a tang, or a square drive portion. Furthermore, the male coupling member 38 may not have a pull stud.

[0052] Referring again to Figure 4, the cutting portion 26 has a cutting portion height H2 measured between the front surface 56 of the head and the base surface 40 of the head in a direction along the longitudinal axis A of the head. The assembly portion 28 has an assembly portion height H4 measured between the rear surface 58 of the head and the base surface 40 of the head in a direction along the longitudinal axis A of the head. According to some embodiments of the subject matter of the present application, the assembly portion height H4 may exceed the cutting portion height H2. Preferably, the assembly portion height H4 may exceed twice the cutting portion height H2.

[0053] The male coupling member 38 includes a head contact surface 54 that extends in the circumferential direction, and the head contact surface 54 extends around the longitudinal axis A of the head. The head contact surface 54 faces radially outward. The head contact surface 54 faces rearward D R The head is then tapered inward at a head cone angle 2α. That is, the head contact surface 54 has a conical shape that faces radially outward, and the head cone angle 2α is an internal angle. The head contact surface 54 is configured for a Morse taper coupling mechanism. According to some embodiments of the subject matter of this application, the head contact surface 54 may be a frustocone. The head cone angle 2α may be in the range of 2.8° ≤ 2α ≤ 3.16° (i.e., a typical Morse taper cone angle). Preferably, the head cone angle 2α may be in the range of 2.9° ≤ 2α ≤ 3.06°. In other words, the head contact surface 54 may define a taper angle α in the range of 1.45° ≤ α ≤ 1.53° with respect to the longitudinal axis A (the taper angle α is half of the cone angle 2α). In some embodiments, the head cone angle 2α may be equal to 2.98°. As described below, it should be noted that the head contact surface 54 is intended to contact the corresponding surface on the tool holder 24 when the rotary cutting tool 20 is in the locked position.

[0054] The terms “radially inward” and “radially outward” should be understood throughout the specification and claims to refer to relative positions toward and away from the respective axes in directions perpendicular to the longitudinal axis A of the head and / or the longitudinal axis C of the holder, as shown in Figures 4–9 and 10–12. The term “conical angle” should be understood throughout the specification and claims to refer to the angle formed by the tapered surface of the cone in the longitudinal section. Note that the term “longitudinal section” refers to a section taken in a plane containing the longitudinal axis.

[0055] The conical head contact surface 54 has a maximum diameter, which is the maximum head cone diameter D. max The conical head contact surface 54 has a minimum head cone diameter D, which is the minimum diameter of the conical head contact surface 54. min It has.

[0056] Referring to Figures 4, 8, and 9, according to some embodiments of the subject matter of the present application, the head contact surface 54 may intersect the head rear surface 58 via a head convex chamfered surface 62 that forms a convex chamfered corner. That is, the head convex chamfered surface 62 extends between the head contact surface 54 and the head rear surface 58, and can join the head contact surface 54 and the head rear surface 58.

[0057] According to some embodiments of the subject matter of this application, the head contact surface 54 may intersect the head base surface 40 via a head concave chamfered surface 63 that forms a concave chamfered corner. That is, the head concave chamfered surface 63 extends between the head contact surface 54 and the head base surface 40, and can join the head contact surface 54 and the head base surface 40.

[0058] The head contact surface 54 has a head cone height H1 measured in a direction along the longitudinal axis A of the head. According to some embodiments of the subject matter of the present application, the head cone height H1 is the maximum head cone diameter D max It can exceed the maximum head cone diameter D. In particular, the head cone height H1 is greater than the maximum head cone diameter D. max It can exceed 1.5 times. Therefore, the tapered contact area between the male and female coupling members is larger compared to other known tapered couplings, such as those disclosed in US7,004,692. The head cone height H1 is greater than the maximum head cone diameter D max It can be less than 5 times the maximum head cone diameter D. In particular, the head cone height H1 is less than the maximum head cone diameter D. max It may be less than 2.5 times. The head cone height H1 may exceed 80% of the assembly portion height H4. The head cone height H1 may exceed the cutting outer diameter O.

[0059] Referring to Figures 2 to 9 in general, the replaceable cutting head 22 includes a head through-hole 42 extending through the cutting portion 26 and the assembly portion 28. In Figure 4, the head through-hole 42 is hidden and is therefore shown by a dashed line. The head through-hole 42 is configured to accept fastening members, as will be described later in this specification. The head through-hole 42 includes a through-hole circumferential surface 44 extending around the through-hole central axis E. Generally, the through-hole circumferential surface 44 faces toward the through-hole central axis E. The through-hole circumferential surface 44 intersects the head front surface 56 and the head rear surface 58. That is, the head through-hole 42 opens to the head front surface 56 and the head rear surface 58 (at the head front hole opening 57 and the head rear hole opening 59, respectively). According to some embodiments of the subject matter of this application, the head longitudinal axis A may intersect the head front hole opening 57 and the head rear hole opening 59. The central axis E of the through hole may coincide with the longitudinal axis A of the head. Note that the head through hole 42 does not have a female thread.

[0060] According to some embodiments of the subject matter of this application, the head through-hole 42 may include a clamping portion receiving portion 64 and a shank portion receiving portion 66. The shank portion receiving portion 66 is offset axially (along the longitudinal axis A) from the clamping portion receiving portion 64. The shank portion receiving portion 66 may extend between the clamping portion receiving portion 64 and the rear surface 58 of the head. The clamping portion receiving portion 64 may extend to the front surface 56 of the head. The clamping portion receiving portion 64 is in the rear direction D R It may include at least one bearing surface 52 that is tapered (inclined) inward. Thus, at least one bearing surface 52 faces radially inward. The shank portion receiving portion 66 faces forward D F In this configuration, at least one support surface 52 can transition to the clamping portion receiving portion 64. At least one support surface 52 can be located entirely in front of the head base surface 40. That is, at least one support surface 52 can be located entirely within the cutting portion 26.

[0061] Referring to Figures 5 to 7, according to some embodiments of the subject matter of the present application, the head through-hole 42 may include a through-hole central portion 46 extending between the head front surface 56 and the head rear surface 58 along the head longitudinal axis A. The head through-hole 42 is non-cylindrical; that is, the head through-hole 42 has a non-constant radial cross-section along the through-hole central axis E. In particular, the head through-hole 42 may include at least two radially extending through-hole extensions 48 extending from the head rear surface 58 to the clamping portion receiving portion 64. At least two through-hole extensions 48 may extend to the head front surface 56. At least two through-hole extensions 48 may merge with the through-hole central portion 46 and be arranged radially outward from the through-hole central portion 46. At least two through-hole extensions 48 may be identical and have rotational symmetry about the through-hole central axis E. In this non-limiting example, the head through-hole 42 includes two strictly diametrically opposed through-hole expansions 48 around the through-hole central axis E. The head through-hole 42 may also include at least two through-hole constrictions 49 extending from the head rear surface 58 to the clamping portion receiving portion 64. Each pair of adjacent through-hole constrictions 49 is angled apart by their respective through-hole expansions 48. The number of through-hole constrictions 49 may coincide with the number of through-hole expansions 48. Thus, two through-hole constrictions 49 may face each other diametrically with 180° rotational symmetry around the through-hole central axis E.

[0062] As shown in Figures 5 and 7, according to some embodiments of the subject matter of this application, the clamping portion receiving portion 42 may include at least two clamping wing pockets 50. At least two clamping wing pockets 50 are designed to receive each clamping wing of the fastening member 92, which will be described later in this specification. The number of clamping wing pockets 50 may correspond to the number of through-hole expansions 48. At least two clamping wing pockets 50 may merge with the through-hole central portion 46 and be positioned radially outward from the through-hole central portion 46. Each clamping wing pocket 50 may merge with its respective through-hole radial expansion 48 and extend forward rotationally (around the head longitudinal axis A) from the through-hole radial expansion 48. Each clamping wing pocket 50 may be angled with its respective through-hole expansion 49 and positioned axially forward of the through-hole expansion 49. In this non-limiting example, the head through-hole 42 includes two strictly diametrically opposed clamping wing pockets 50 that are 180° rotationally symmetrical with respect to the through-hole's central axis E.

[0063] According to some embodiments of the subject matter of the present application, each clamping wing pocket 50 may include a pocket side surface 53 extending radially with respect to the holder longitudinal axis C. The pocket side surface 53 extends radially with respect to the rear rotation direction R R The clamping portion receiving portion 64 may include at least two support surfaces 52, each support surface 52 being formed from a portion of the respective clamping wing pocket 50. Referring again to Figures 5 and 7, each support surface 52 may extend from the respective pocket side surface 53 to the adjacent through-hole expansion portion 48. At least two clamping wing pockets 50 may be identical and have rotational symmetry about the through-hole central axis E.

[0064] Another aspect of the subject matter of the present application relates to a tool holder 24. Referring next to Figures 10 to 12, the tool holder 24 has a holder longitudinal axis C. According to some embodiments of the subject matter of the present application, the tool holder 24 may include a holder circumferential surface 74, the holder circumferential surface 74 extending around the holder longitudinal axis C and defining the boundary of the holder front surface 70.

[0065] According to some embodiments of the subject matter of this application, the holder circumferential surface 74 may include a front holder circumferential surface 76, a rear holder circumferential surface 78, and an intermediate holder circumferential surface 77 extending between the front holder circumferential surface 76 and the rear holder circumferential surface 78. The front holder circumferential surface 76 may be closer to the holder front surface 70 than both the intermediate holder circumferential surface 77 and the rear holder circumferential surface 78. The front holder circumferential surface 76 and the rear holder circumferential surface 78 are on different virtual coaxial cylinders. The front holder circumferential surface 76 may have a smaller diameter than the diameter of the rear holder circumferential surface 78. The intermediate holder circumferential surface 77 may be inclined radially outward from the front holder circumferential surface 76 to the rear holder circumferential surface 78.

[0066] Referring to Figure 12, the tool holder 24 includes a female connector 68 extending rearward from the holder front surface 70. The holder front surface 70 extends transversely with respect to the holder longitudinal axis C. According to some embodiments of the subject matter of the present application, the holder front surface 70 may be perpendicular to the holder longitudinal axis C. The female connector 68 includes a holder female thread portion 72 extending along the holder longitudinal axis C. The holder female thread portion 72 has a female thread length LI measured in the direction of the holder longitudinal axis C.

[0067] The female connector 68 includes two support portions, namely a front support portion 80 and a rear support portion 82, with the front support portion 80 located in front of the rear support portion 82. The front support portion 80 and the rear support portion 82 are located on either side of the holder female thread portion 72. In other words, the holder female thread portion 72 is located between the front support portion 80 and the rear support portion 82.

[0068] The front support portion 80 includes a front holder contact surface 84 extending around the holder's longitudinal axis C. The front holder contact surface 84 is located in front of the holder's female thread portion 72 (in other words, the holder's female thread portion 72 is located behind the front holder contact surface 84). The holder's female thread portion 72 is spaced at least by the amount of the front holder contact surface 84 from the holder's front surface 70. The front holder contact surface 84 faces inward with respect to the holder's longitudinal axis C. The front holder contact surface 84 is tapered inward at a holder cone angle 2γ in the direction toward (behind) the holder's female thread portion 72. That is, the front holder contact surface 84 has a conical shape that faces radially inward, and the holder cone angle 2γ is an outward angle. The front holder contact surface 84 is configured for a Morse taper coupling mechanism. According to some embodiments of the subject matter of this application, the front holder contact surface 84 may be a frustoconical shape. The holder cone angle 2γ may be in the range of 2.8° ≤ 2γ ≤ 3.16°. Preferably, the holder cone angle 2γ may be in the range of 2.9° ≤ 2γ ≤ 3.06°. In other words, the front holder contact surface 84 may define a taper angle γ in the range of 1.45° ≤ γ ≤ 1.53° with respect to the holder longitudinal axis C. In some embodiments, the holder cone angle 2γ may be equal to 2.98°.

[0069] Referring to Figure 12, the conical front holder contact surface 84 is the maximum diameter of the conical front holder contact surface 84, which is the maximum holder cone diameter d. max The conical front holder contact surface 84 has a minimum holder cone diameter d, which is the minimum diameter of the conical front holder contact surface 84. min It has.

[0070] The front holder contact surface 84 has a holder cone height H3 measured along the longitudinal axis C of the holder. The length LI of the female thread portion may be smaller than the holder cone height H3. The holder cone height H3 is equal to the maximum holder cone diameter d max It can exceed this. In particular, the holder cone height H3 is greater than the maximum holder cone diameter d. max It can exceed 1.5 times. The holder cone height H3 is the maximum holder cone diameter d max It can be made smaller than 5 times. In particular, the holder cone height H3 is the maximum holder cone diameter dmax It can be made smaller than 2.5 times that size.

[0071] According to some embodiments of the subject matter of the present application, the rear support portion 82 may include a rear holder contact surface 88 extending around the longitudinal axis C of the holder. The rear holder contact surface 88 may be cylindrical.

[0072] According to some embodiments of the subject matter of the present application, the tool holder 24 may include at least one coolant passage 79. The at least one coolant passage 79 may open to the outer circumferential surface 74 of the holder at a coolant passage outlet 79a. The coolant passage outlet 79a is configured to guide the coolant toward the outer cutting edge 30.

[0073] Preferably, at least one coolant passage 79 may open at least partially to the outer circumferential surface 77 of the intermediate holder. In this non-limiting example shown, the tool holder 24 includes exactly four coolant passages 79 and exactly four coolant passage outlets 79a that are evenly distributed around the longitudinal axis C of the holder. At least one coolant passage 79 may be spaced apart from the female member 68. At least a portion of at least one coolant passage 79 may be radially outward from the female member 68.

[0074] Another aspect of the subject matter of this application relates to a rotary cutting tool 20 including the interchangeable cutting head 22 and tool holder 24 defined above. Referring to Figures 13 to 16, the rotary cutting tool 20 also includes a fastening member 92. The fastening member 92 is elongated along the longitudinal axis F of the fastening member. The fastening member 92 includes a fastening member clamping portion 94 and a fastening member shank portion 98. The fastening member clamping portion 94 and the fastening member shank portion 98 are offset from each other axially (with respect to the longitudinal axis F of the fastening member). According to some embodiments of the subject matter of this application, the fastening member 92 may be formed integrally by having a single, one-piece structure. The fastening member 92 may typically be made from steel.

[0075] According to some embodiments of the subject matter of the present application, the fastening portion 94 of the fastening member may include a fastening surface 102, the fastening surface 102 being tapered (inclined) inward in the direction from the fastening portion 94 toward the fastening member shank portion 98. Thus, the fastening surface 102 faces radially outward with respect to the longitudinal axis F of the fastening member.

[0076] According to some embodiments of the subject matter of the present application, the fastening portion 94 may include at least two fastening wings 100 extending radially outward with respect to the longitudinal axis F of the fastening member. That is, the fastening member 92 may have a "slip-on" configuration. In this non-limiting example shown, the fastening portion 94 may include exactly two fastening wings 100 that are diametrically opposed to each other with respect to the longitudinal axis F of the fastening member.

[0077] According to some embodiments of the subject matter of the present application, each fastening member clamping wing 100 may include two opposite wing sides 104a, 104b extending radially with respect to the longitudinal axis F of the fastening member. The two wing sides 104a, 104b face away from each other. The fastening member clamping portion 94 may include at least two clamping surfaces 102, each clamping surface 102 formed from a portion of each fastening member clamping wing 100. The clamping surface 102 may extend between the two wing sides 104a, 104b.

[0078] The fastening member shank portion 98 includes a fastening member male thread portion 96. The fastening member male thread portion 96 has a male thread length LE measured in the direction of the fastening member longitudinal axis F. According to some embodiments of the subject matter of this application, the fastening member male thread portion 96 may be interrupted (i.e., discontinuous; not shown).

[0079] According to some embodiments of the subject matter of this application, the fastening member shank portion 98 may include an elongated fastening member neck portion 99, which extends between the fastening member tightening portion 94 and the fastening member male thread portion 96. The fastening member neck portion 99 has a fastening member neck height N, which is measured in a direction along the longitudinal axis F of the fastening member. Unlike, for example, US7,004,692, in which the threaded member has a hollow portion (formed from a through hole that supplies coolant to a coolant outlet), the fastening member 92 of the present invention is solid in the sense that it does not have a through hole. Therefore, the length of the fastening member 92 can be increased without the risk of weakening. In this regard, it should be noted that the fastening member neck height N may exceed the male thread portion length LE. In particular, the fastening member neck height N may exceed twice the male thread portion length LE.

[0080] According to some embodiments of the subject matter of this application, the fastening member shank portion 98 may include at least two fastening member elastic pins 106 spaced at an angle around the longitudinal axis F of the fastening member. The at least two fastening member elastic pins 106 are radially flexible. The at least two fastening member elastic pins 106 may be located at the rear end of the fastening member 92 and therefore may be located further from the fastening member tightening portion 94 than the fastening member male thread portion 96. The at least two fastening member elastic pins 106 may be spaced by a fastening portion pin gap 108. In this non-limiting example shown, the fastening member 92 may include exactly two fastening member elastic pins 106 that are diametrically opposed to each other around the longitudinal axis F of the fastening member.

[0081] The rotary cutting tool 20 is adjustable between a released position and a locked position. In the released position of the rotary cutting tool 20, as shown in Figure 2, the rotary cutting tool 20 is unassembled, and the male coupling member 38 is located outside the female coupling member 68.

[0082] The assembly of the rotary cutting tool 20 can be achieved by performing the following steps. According to the first method of assembly, the fastening member shank portion 98 is inserted into the female coupling member 68. The fastening member male thread portion 96 is rotated in the rear direction R. RThen rotate it within the holder female thread portion 72 so that the fastening member male thread portion 96 and the holder female thread portion 72 first screw into each other. In this position, for any and all fastening member tightening wings 100, one of the two opposite wing sides 104a, 104b is rotated in the forward direction R. F Next, the replaceable cutting head 22 is placed on the fastening member tightening portion 94 and oriented so that at least two through-hole expansions 48 are aligned with at least two fastening member tightening wings 100. Next, the replaceable cutting head 22 is moved toward the tool holder 24, allowing at least two fastening member tightening wings 100 to pass through at least two through-hole expansions 48 until the head contact surface 54 first contacts the holder contact surface 84, and the male coupling member 38 is inserted into the female coupling member 68. The replaceable cutting head 22 is rotated in the rear direction R until each fastening member tightening wing 100 is positioned within the tightening wing pocket 50 and each pocket side surface 53 facing the rear direction abuts against the respective wing side surface 104a facing the front direction. RThe interchangeable cutting head 22 is rotated (optionally by a key not shown). Further rotation of the interchangeable cutting head 22 causes the fastening member 92 to rotate as each pocket side surface 53 facing the direction of rotation comes into contact with each wing side surface 104a facing the direction of rotation, causing the fastening member 92 to further screw the fastening member male thread 96 into the holder female thread 72 and to pull the fastening member 92 into the female coupling member 68 until each clamping surface 102 comes into contact with the respective support surface 52. Further rotation of the interchangeable cutting head 22 (and therefore the fastening member 92) causes the fastening member 92 to push the male coupling member 38 of the interchangeable cutting head 22 into the female coupling member 68 of the tool holder 24 until the conical head contact surface 54 comes into contact with the conical front holder contact surface 84, and finally a Morse taper coupling is created between the male coupling member 38 and the female coupling member 68 that defines the locking position of the rotary cutting tool 22. As the male coupling member is advanced into the female member, the surface pressure between the two parts increases. The resulting friction prevents slippage, thereby causing the taper to self-retain. In this regard, it should be noted that (unlike, for example, US7,004,692) there is no axial stopper to prevent the male coupling member 36 from being inserted into the female coupling member 68. It should be further noted that the fastening member 92, unlike, for example, a hammer, advances the male coupling member into the female member in a controlled and precise manner.

[0083] In the locked position of the rotary cutting tool 20, the male coupling member 38 is removably held within the female coupling member 68 by a fastening member 92 located in the head through-hole 42. The male threaded portion 96 of the fastening member and the female threaded portion 72 of the holder are screwed together. The longitudinal axis A of the head, the longitudinal axis C of the holder, and the longitudinal axis F of the fastening member coincide with each other (i.e., are aligned). According to some embodiments of the subject matter of this application, at least one clamping surface 102 may abut against at least one support surface 52. The head base surface 40 may be spaced apart from the holder front surface 70. That is, the head base surface 40 does not contact the holder front surface 70. At least two fastening member elastic pins 106 may be elastically deformable relative to the holder contact surface 88. In the “insert” configuration of the fastening member 92, each of the at least two clamping surfaces 102 may abut against its respective support surface 52. At least two of the clamping wing pockets 50 have pocket sides 53 facing the rear direction of rotation that can contact the respective wing sides 104a facing the front direction of rotation.

[0084] Unlike US7,004,692, where the conical contact surface is primarily for centering purposes, the conical contact surface of the present invention, through a Morse taper coupling, provides most of the torque transmission from the tool holder 24 to the cutting head 22. Consequently, less force and stress is applied to the fastening members (especially the fastening member clamping wings 100). This is particularly beneficial for rotary cutting tools with small cutting diameters (i.e., 7.6 mm or less) and correspondingly small fastening members, where a) there is a high probability of fracture, b) the head is not very effectively fixed into the pocket, and c) torque transmission to the head is not very effective.

[0085] While the subject matter of this application has been described in some detail, please understand that various modifications and alterations may be made without departing from the spirit or scope of the invention as claimed below.

Claims

1. A replaceable cutting head (22) for rotary cutting operation, having a longitudinal axis (A) of the head, wherein the longitudinal axis (A) is in the opposite forward direction (D Ｆ ) and rearward (D Ｒ ) and the opposite forward rotation direction (R Ｆ ) and the direction after rotation (R Ｒ ) defines the rotation forward direction (R Ｆ ) is the cutting direction, and the replaceable cutting head (22) is, A front portion that forms the cutting portion (26) and a rear portion that forms the assembly portion (28), The opposite head front surface (56) and head rear surface (58), and the head outer peripheral surface (60) extending between the head front surface (56) and the head rear surface (58), wherein the head front surface (56) is located in the cutting portion (26) and the head rear surface (58) is located in the assembly portion (28), the opposite head front surface (56) and head rear surface (58) and head outer peripheral surface (60), A head through hole (42) having an outer peripheral surface (44) of the through hole and The outer circumferential surface (44) of the through hole extends around the central axis (E) of the through hole and intersects with the front surface (56) of the head and the rear surface (58) of the head. The assembly portion (28) includes a male coupling member (38) that protrudes rearward from the head base surface (40), the head base surface (40) extends transversely with respect to the longitudinal axis (A) of the head, and defines a boundary between the cutting portion (26) and the assembly portion (28), The male coupling member (38) is a replaceable cutting head (22) having a conical head contact surface (54) configured for a Morse taper coupling mechanism.

2. The head contact surface (54) is in the rear direction (D Ｒ ) The head is tapered inward at a conical angle (2α), The replaceable cutting head (22) according to claim 1, wherein the head cone angle (2α) is within the range of 2.8° ≤ 2α ≤ 3.16°.

3. The replaceable cutting head (22) according to claim 2, wherein the head cone angle (2α) is within the range of 2.9° ≤ 2α ≤ 3.06°.

4. The head through hole (42) is A clamping portion receiving portion (64) and a shank portion receiving portion (66) which is offset in the axial direction from the clamping portion receiving portion (64) The shank portion receiving portion (66) extends between the clamping portion receiving portion (64) and the head rear surface (58), The aforementioned fastening portion receiving portion (64) is in the rear direction (D Ｒ A replaceable cutting head (22) according to any one of claims 1 to 3, comprising at least one support surface (52) that is tapered inward.

5. The interchangeable cutting head (22) according to claim 4, wherein the clamping portion receiving portion (64) extends to the front surface (56) of the head.

6. The replaceable cutting head (22) according to claim 4 or 5, wherein the head through hole (42) comprises at least two through hole expansion portions (48) extending in the radial direction, and the through hole expansion portions (48) extend from the rear surface (58) of the head to the clamping portion receiving portion (64).

7. The aforementioned fastening portion receiving portion (64) is At least two clamping wing pockets (50), each of which the clamping wing pockets (50) merges with the respective through-hole radial expansion portion (48), and the two clamping wing pockets (50) are in a forward rotational direction from the through-hole radial expansion portion (48) around the head longitudinal axis (A), At least two support surfaces (52) and The replaceable cutting head (22) according to claim 6, wherein each of the support surfaces (52) is formed from a portion of the respective clamping wing pockets (50).

8. The head through-hole (42) comprises two strictly diametrically opposed through-hole expansion portions (48) around the central axis (E) of the through-hole, The interchangeable cutting head (22) according to claim 7, wherein the clamping portion receiving portion (64) comprises two clamping wing pockets (50) that are strictly opposite to each other in the diametrical direction around the central axis (E) of the through hole.

9. The head contact surface (54) has a head cone height (H1) measured in a direction along the longitudinal axis (A) of the head, The head contact surface (54) has a maximum head cone diameter (D ｍａｘ ), and the head cone height (H1) exceeds the maximum head cone diameter (D ｍａｘ ). The replaceable cutting head (22) according to any one of claims 1 to 7.

10. The head cone height (H1) is equal to the maximum head cone diameter (D ｍａｘ The replaceable cutting head (22) according to claim 9, which is more than 1.5 times the size of the above.

11. The assembly portion (28) has an assembly portion height (H4) measured between the rear surface (58) of the head and the base surface (40) in a direction along the longitudinal axis (A) of the head, The replaceable cutting head (22) according to claim 9 or 10, wherein the head cone height (H1) exceeds 80% of the assembly portion height (H4).

12. The cutting portion (26) has a cutting portion height (H2) measured between the front surface (56) of the head and the base surface (40) of the head in a direction along the longitudinal axis (A) of the head, The replaceable cutting head (22) according to claim 11, wherein the height of the assembly portion (H4) exceeds the height of the cutting portion (H2).

13. The replaceable cutting head (22) according to claim 12, wherein the height of the assembly portion (H4) is greater than twice the height of the cutting portion (H2).

14. The replaceable cutting head (22) according to any one of claims 1 to 13, wherein the male coupling member (38) does not have a male screw portion, a tang, and a square drive portion.

15. The replaceable cutting head (22) according to any one of claims 1 to 14, wherein at least one of the support surfaces (52) is located entirely in front of the head base surface (40).

16. A tool holder (24) having a holder longitudinal axis (C) and a female coupling member (68) extending rearward from the holder front surface (70), wherein the holder front surface (70) extends transversely with respect to the holder longitudinal axis (C), and the female coupling member (68) A conical front holder contact surface (84) configured for the Morse tapered coupling mechanism, The holder female thread portion (72) located behind the front holder contact surface (84) and A tool holder (24) is provided.

17. The front holder contact surface (84) is tapered inward toward the holder female thread portion (72) at a holder cone angle (2γ). The tool holder (24) according to claim 16, wherein the holder cone angle (2γ) is within the range of 2.8° ≤ 2γ ≤ 3.16°.

18. The tool holder (24) according to claim 17, wherein the holder cone angle (2γ) is within the range of 2.9° ≤ 2γ ≤ 3.06°.

19. The tool holder (24) is The holder outer circumferential surface (74) extends around the longitudinal axis (C) of the holder and defines the boundary of the front surface (70) of the holder, A tool holder (24) according to any one of claims 16 to 18, comprising a coolant passage (79) opening to the outer peripheral surface (74) of the holder.

20. The holder outer peripheral surface (74) comprises a front holder outer peripheral surface (76) and a rear holder outer peripheral surface (78), and an intermediate holder outer peripheral surface (77) extending between the front holder outer peripheral surface (76) and the rear holder outer peripheral surface (78), wherein the front holder outer peripheral surface (76) is closer to the holder front surface (70) than both the intermediate holder outer peripheral surface (77) and the rear holder outer peripheral surface (78), The outer circumferential surface (76) of the front holder has a diameter smaller than the outer circumferential surface (78) of the rear holder. The tool holder (24) according to claim 19, wherein the coolant passage (79) opens at least partially to the outer peripheral surface (77) of the intermediate holder.

21. The tool holder (24) according to claim 19 or 20, further comprising a rear support portion (82), the rear support portion (82) having a rear holder contact surface (88) extending around the longitudinal axis (C) of the holder.

22. The front holder contact surface (84) has a holder cone height (H3) measured in a direction along the longitudinal axis (C) of the holder, The front holder contact surface (84) has a maximum holder cone diameter (d ｍａｘ ) has, The holder cone height (H3) is equal to the maximum holder cone diameter (d ｍａｘ A tool holder (24) according to any one of claims 16 to 21, which exceeds ).

23. The holder cone height (H3) is equal to the maximum holder cone diameter (d ｍａｘ The tool holder (24) according to claim 22, which is more than 1.5 times the size of the other tool holder (24).

24. The holder female thread portion (72) has a female thread length (LI) measured in the direction along the holder longitudinal axis (C), The tool holder (24) according to claim 22 or 23, wherein the length of the female thread portion (LI) is smaller than the holder cone height (H3).

25. A rotary cutting tool (20), wherein the rotary cutting tool (20) is A replaceable cutting head (22) according to any one of claims 1 to 15, A tool holder (24) according to any one of claims 16 to 24, An elongated fastening member (92) along the longitudinal axis (F) of the fastening member and The fastening member (92) comprises a fastening member tightening portion (94) and a fastening member shank portion (98) that is axially offset from the fastening member tightening portion (94) along the longitudinal axis (F) of the fastening member, the fastening member tightening portion (94) comprises a tightening surface (102) that is tapered inward in the direction from the fastening member tightening portion (94) toward the fastening member shank portion (98), and the fastening member shank portion (98) comprises a fastening member male thread portion (96). The rotary cutting tool (20) is adjustable between a released position and a locked position, and in the locked position, The male coupling member (38) is removably held within the female coupling member (68) by the fastening member (92) located within the head through hole (42), and the male threaded portion (96) of the fastening member and the female threaded portion (72) of the holder are screwed together. The head contact surface (54) contacts the front holder contact surface (84), thereby creating a Morse tapered connection between the male coupling member (38) and the female coupling member (68) in a rotary cutting tool (20).

26. At the aforementioned locking position, The rotary cutting tool (20) according to claim 25, wherein at least one of the clamping surfaces (102) abuts against at least one of the support surfaces (52).

27. The fastening member (92) has a single, integrated structure, thereby forming the rotary cutting tool (20) according to claim 25 or 26.

28. In the locking position, the head base surface (40) is spaced apart from the holder front surface (70), the rotary cutting tool (20) according to any one of claims 25 to 27.

29. The rotary cutting tool (20) is a reamer, according to any one of claims 25 to 28.

30. The head through hole (42) comprises at least two through hole extensions (48) that extend from the rear surface (58) of the head to the clamping portion receiving portion (64), The aforementioned fastening portion receiving portion (64) is At least two clamping wing pockets (50), each of which the clamping wing pockets (50) merges with the respective through-hole radial expansion portion (48), and the two clamping wing pockets (50) are in a forward rotational direction from the through-hole radial expansion portion (48) around the head longitudinal axis (A), At least two support surfaces (52) and Each of the support surfaces (52) is formed from a portion of the respective clamping wing pockets (50), The fastening portion (94) of the fastening member comprises at least two fastening member tightening wings (100) that extend radially outward with respect to the longitudinal axis (F) of the fastening member, The fastening portion (94) of the fastening member comprises at least two fastening surfaces (102), each of which is formed from a portion of the respective fastening wing (100) of the fastening member. Each of at least two of the fastening member clamping wings (100) is located within its respective clamping wing pocket (50), At the aforementioned locking position, A rotary cutting tool (20) according to any one of claims 25 to 29, wherein each of the at least two clamping surfaces (102) abuts against the respective support surface (52).

31. Each of the at least two clamping wing pockets (50) is provided with a pocket side (53), the pocket side (53) extending radially with respect to the holder longitudinal axis (C) and the rear rotation direction (R) Ｒ ) facing, Each of at least two of the fastening member tightening wings (100) has two opposite wing sides (104a, 104b) extending radially with respect to the longitudinal axis (F) of the fastening member, At the aforementioned locking position, For any and all of the fastening member tightening wings (100), one of the two opposite wing sides (104a) is in the forward rotation direction (R Ｆ ) facing, The rotary cutting tool (20) according to claim 30, wherein each pocket side surface (53) of at least two of the clamping wing pockets (50) facing the direction after rotation abuts against each of the wing side surfaces (104a) facing the direction before rotation.

32. The fastening member shank portion (98) is provided with an elongated fastening member neck portion (99), and the elongated fastening member neck portion (99) extends between the fastening member tightening portion (94) and the fastening member male thread portion (96). The neck portion (99) of the fastening member has a neck height (N) of the fastening member measured in a direction along the longitudinal axis (F) of the fastening member, The fastening member male thread portion (96) has a male thread portion length (LE) measured in a direction along the longitudinal axis (F) of the fastening member, The rotary cutting tool (20) according to claim 30 or 31, wherein the neck height (N) of the fastening member exceeds the length (LE) of the male thread portion.

33. The head through-hole (42) comprises two strictly diametrically opposed through-hole expansion portions (48) around the central axis (E) of the through-hole, The clamping portion receiving portion (64) comprises two clamping wing pockets (50) that are strictly opposite to each other in the diametrical direction around the central axis (E) of the through hole, The rotary cutting tool (20) according to any one of claims 30 to 32, wherein the fastening member tightening portion (94) comprises two strictly fastening member tightening wings (100) that are diametrically opposed to each other around the longitudinal axis (F) of the fastening member.

34. The tool holder (24) further comprises a rear support portion (82), the rear support portion (82) having a rear holder contact surface (88) extending around the longitudinal axis (C) of the holder, The fastening member shank portion (98) is At least two fastening member elastic pins (106) spaced apart at an angle around the longitudinal axis (F) of the fastening member. The fastening member elastic pins (106) are provided, and at least two of the fastening member elastic pins (106) are radially flexible and are located further away from the fastening member tightening portion (94) than the fastening member male thread portion (96). At the aforementioned locking position, The rotary cutting tool (20) according to any one of claims 30 to 33, wherein at least two of the fastening member elastic pins (106) are elastically deformable with respect to the rear holder contact surface (88).

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