Insert holder and cutting tool with weight-reducing void

Abstract

The insert holder (22) includes a cutting portion (38) and a shank portion (46). The insert holder further includes a cavity (56) including a cavity chamber (58) that acts to reduce the weight of the insert holder and a plurality of cavity through recesses (66). The plurality of cavity through recesses open to the cavity chamber and to the outer periphery of the shank portion. A cutting tool is provided having a cutting insert (24) releasably attached to the insert holder.

Description

[Technical field]

[0001] The subject matter of this application relates generally to insert holders, and more particularly to such insert holders that also have cavities to reduce the weight of the insert holder. [Background technology]

[0002] As is known in the art of metal cutting, cutting tools may include cavities to reduce the weight of the cutting tool. One example of such a cutting tool is disclosed, for example, in US 7,226,254, which discloses a bar-shaped tool of sintered material for machining a workpiece, the bar-shaped tool having a closed central recess designed to achieve material and weight savings. Another example is US 7,374,374, which shows a tool with a central passage configured to reduce the mass of cemented carbide in the tool. Summary of the Invention [Problem to be solved by the invention]

[0003] One object of the present subject matter is to provide an insert holder that reduces weight while maintaining effective insert holder stiffness. [Means for solving the problem]

[0004] According to a first aspect of the present subject matter, there is provided an insert holder elongated along a holder longitudinal axis, the holder longitudinal axis defining opposite forward and rearward directions, the insert holder being integrally formed so as to have a single, unitary construction; a holder front end surface, a holder rear end surface, and a holder outer circumferential surface extending between the holder front end surface and the holder rear end surface and extending about a holder longitudinal axis; a cutting portion having an insert pocket for releasably retaining a cutting insert, the cutting portion being located at a front end of the insert holder; a shank portion extending rearward from the cutting portion, the shank portion having a holder outer peripheral surface including a shank radial centering surface; a weight reduction cavity; The weight reduction cavity is a hollow chamber enclosed within an insert holder, the hollow chamber having an inner chamber wall; a plurality of hollow through recesses; The plurality of cavity through recesses open into (i) the chamber inner wall surface and (ii) the shank radial centering surface, with the chamber inner wall surface forming a plurality of inner recess openings and the shank radial centering surface forming a plurality of outer recess openings.

[0005] According to a second aspect of the present subject matter, there is provided a cutting tool, comprising: The cutting tools are The above types of insert holders and a cutting insert having at least one cutting edge releasably retained within the insert pocket; Equipped with.

[0006] According to a third aspect of the present subject matter, there is provided an insert holder elongated along a holder longitudinal axis, the holder longitudinal axis defines opposite forward and rearward directions; The insert holder is integrally formed to have a single, integral structure a holder front end surface, a holder rear end surface, and a holder outer circumferential surface extending between the holder front end surface and the holder rear end surface and extending about a holder longitudinal axis; a cutting portion having an insert pocket for releasably retaining a cutting insert, the cutting portion being located at a front end of the insert holder; a hollow shank portion extending rearwardly from the cutting portion; The hollow shank part is a shank radial centering surface which is a part of the outer peripheral surface of the holder; a shank flat surface that is also part of the holder outer peripheral surface, that is oriented parallel to the holder longitudinal axis and that intersects the shank radial centering surface; a plurality of hollow through recesses connecting the inner wall surface of the hollow shank portion to the radial centering surface of the shank; has.

[0007] It will be appreciated that the above is a summary and that the features described below may be applicable to the subject matter of the present application in any combination, for example any of the following features may be applicable to a cutting tool or an insert holder.

[0008] The hollow chamber may be enclosed solely within the shank portion.

[0009] The hollow chamber may be spaced from the rear face of the holder.

[0010] Each cavity through recess may comprise an inner recess wall surface extending about a recess central axis, two opposing through recess ends located along the inner recess wall surface between a respective inner recess opening and a respective outer recess opening, and an elongated through recess intermediate portion extending lengthwise between the two opposing through recess ends, and each cavity through recess may be elongated in a direction along the holder longitudinal axis.

[0011] For a given one of the plurality of hollow through recesses, one of the two through recess ends may be closer to the cut portion than the other of the two through recess ends.

[0012] The shank radial centering surface may be cylindrical or conical about the holder longitudinal axis.

[0013] The shank radial centering surface may be cylindrical about the holder longitudinal axis. The cylindrical shank radial centering surface may have a shank diameter.

[0014] The inner chamber wall surface may include two opposing chamber end surfaces and a chamber perimeter surface extending between the chamber end surfaces about a central chamber axis. The chamber perimeter surface may be cylindrical about the central chamber axis, the cylindrical chamber perimeter surface having a chamber diameter. The chamber diameter may be greater than one-quarter the shank diameter and less than three-quarters the shank diameter.

[0015] The chamber diameter may be equal to half the shank diameter.

[0016] The plurality of cavity through recesses may comprise N cavity through recesses (66), where N is a positive integer satisfying the condition 5≦N≦9.

[0017] N may be equal to 7.

[0018] The plurality of hollow through recesses may be angularly spaced about the holder longitudinal axis.

[0019] The plurality of cavity through-recesses may be angularly spaced apart by a plurality of shank support members, with each circumferentially adjacent pair of the cavity through-recesses being spaced apart by a respective shank support member.

[0020] The shank radial centering surface on each shank support member may be wider in the circumferential direction than the respective outer recess opening.

[0021] In a cross section taken in a radial plane perpendicular to the holder longitudinal axis and intersecting the plurality of shank support members, each of the plurality of shank support members may have an annular segmental basic shape.

[0022] The holder outer circumferential surface at the shank portion may include a shank flat surface oriented parallel to the holder longitudinal axis and intersecting the shank radial centering surface.

[0023] The shank flat surface intersects the projected path of at least one of the plurality of cavity through recesses such that the plurality of cavity through recesses comprises at least one truncated cavity through recess.

[0024] For each cavity through-recess that is not a truncated cavity through-recess, one of the two through-recess ends may be closer to the cutting portion than the holder rear end face, and the other of the two through-recess ends may be closer to the holder rear end face than the cutting portion.

[0025] The insert holder can include a flat support member that is angularly positioned between the two hollow through recesses and incorporates a portion of the shank flat surface.

[0026] The plurality of cavity through-recesses may comprise a plurality of truncated cavity through-recesses. The planar support member may be located between two of the truncated cavity through-recesses.

[0027] The insert holder can include a cooling conduit, the cooling conduit including a plurality of cooling passages, each cooling passage having a passage inlet and a passage outlet in fluid communication with each other. Each cooling passage can pass through a respective shank support member.

[0028] The cooling conduit can include a cooling bath, the cooling bath including an inner bath wall, the cooling bath enclosed within the insert holder forward of the cavity chamber, and each passageway outlet can be located in the inner bath wall.

[0029] The plurality of hollow through recesses may extend helically about the holder longitudinal axis.

[0030] The cutting portion may comprise a plurality of grooves recessed into the holder outer circumferential surface and extending helically about the holder longitudinal axis in the same sense as a plurality of helically extending hollow through recesses.

[0031] Each helically extending cavity through recess can have a recess twist angle, the recess twist angle being greater than or equal to 20° and less than or equal to 40°.

[0032] The holder outer peripheral surface may include a holder intermediate surface oriented transversely to the holder longitudinal axis. The holder intermediate surface may be contained within a bounding plane, the bounding plane being oriented perpendicular to the holder longitudinal axis and defining a boundary between the cutting portion and the shank portion.

[0033] the cutting portion has a cutting portion length and the shank portion has a shank portion length, both of the cutting portion length and the shank portion length being measured in the direction of the holder longitudinal axis; The shank portion length may be greater than the cutting portion length.

[0034] The hollow chamber has a hollow chamber length, measured in the direction of the holder longitudinal axis, which may be greater than half the shank portion length.

[0035] The inner chamber wall surface may include two opposing chamber end surfaces and a chamber perimeter surface extending between the chamber end surfaces about a central chamber axis. The chamber perimeter surface may be cylindrical about the central chamber axis, the cylindrical chamber perimeter surface having a chamber diameter.

[0036] A plurality of interior recess openings may be located on the outer periphery of the cylindrical chamber.

[0037] In a cross section taken in a radial plane perpendicular to the holder longitudinal axis and intersecting the plurality of cavity through recesses, each cavity through recess may extend linearly along a recess central axis.

[0038] The hollow chamber has a hollow chamber length. Along the hollow chamber length of the hollow chamber, the plurality of hollow through recesses can occupy between 10% and 40% of a surface area of ​​the shank radial centering surface.

[0039] The cutting tool may be a rotary cutting tool rotatable about a longitudinal axis of the holder.

[0040] The plurality of cavity through-recesses may be elongate in a direction along the holder longitudinal axis and extend helically about the holder longitudinal axis. In a circumferential direction of the shank radial centering surface, the plurality of cavity through-recesses may be spaced from one another by a shank support member, which is also elongate in said direction along the holder longitudinal axis and extends helically about the holder longitudinal axis.

[0041] The hollow shank portion may include a hollow chamber having a hollow chamber length. The plurality of hollow through recesses may connect the hollow chamber to the shank radial centering surface. Along the hollow chamber length of the hollow chamber, the plurality of hollow through recesses may occupy between 10% and 40% of a surface area of ​​the shank radial centering surface.

[0042] For a better understanding of the present application and to show how it may be carried into practice, reference is now made to the accompanying drawings, in which: [Brief description of the drawings]

[0043] [Figure 1] FIG. 1 is a perspective view of a cutting tool according to the present application. [Diagram 2] FIG. 2 is an exploded view of the cutting tool of FIG. [Diagram 3] FIG. 2 is a rear end view of the insert holder of FIG. 1. [Figure 4] FIG. 4 is a side view of the insert holder of FIG. 3. [Figure 5a] FIG. 5 is a detailed view of FIG. [Figure 5b] FIG. 5B is a view similar to FIG. 5a, but with the insert holder rotated 90° about the holder longitudinal axis. [Figure 6a] FIG. 6 is a longitudinal cross-sectional view of the insert holder taken along line VIa-VIa of FIG. 3, showing the weight reduction cavity; [Figure 6b] FIG. 6b is a view similar to FIG. 6a showing a longitudinal section of another weight reduction cavity; [Figure 7] FIG. 7 is a first radial cross-sectional view of the insert holder taken along line VII-VII of FIG. 4. [Figure 8]FIG. 8 is a second radial cross-sectional view of the insert holder taken along line VIII-VIII in FIG. 4. [Figure 9] FIG. 9 is a third radial cross-sectional view of the insert holder taken along line IX-IX of FIG. 4. [Figure 10] FIG. 2 is a perspective view of the insert holder of FIG. 1 showing a partially obscured weight reduction cavity and obscured cooling conduits in dashed lines. [Figure 11] FIG. 11 is a view similar to FIG. 10 showing the cooling conduits hidden. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0044] It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, dimensions of some of the elements may be exaggerated relative to other elements for clarity or several physical components may be contained within a single functional block or element. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.

[0045] In the following description, various aspects of the subject matter of the present application are described. For purposes of explanation, specific configurations and details are shown in sufficient detail to provide a thorough understanding of the subject matter of the present application. However, it will be apparent to one skilled in the art that the subject matter of the present application may be practiced without the specific configurations and details presented herein.

[0046] Attention is first directed to FIG. 1 , which illustrates a cutting tool 20 for chip removal according to one aspect of the present application. The cutting tool 20 has a tool longitudinal axis A. According to some embodiments of the present subject matter, the cutting tool 20 may be a rotary cutting tool, i.e., the cutting tool 20 is designed to rotate about an axis of rotation. In the illustrated non-limiting example, the cutting tool 20 is a drilling tool. However, the present subject matter is not limited to only drilling tools and may also be applicable to, for example, but not limited to, milling tools.

[0047] The cutting tool 20 includes an insert holder 22, which will be described in further detail herein. The cutting tool 20 also includes a cutting insert 24. The cutting insert 24 has at least one cutting edge 26 designed to perform a metal cutting operation. The cutting insert 24 is typically made from a cemented carbide. The cutting insert 24 may be releasably attached to the insert holder 22.

[0048] Refer now to FIG. 2, which shows an insert holder 22, which illustrates another embodiment of the present application. The insert holder 22 is typically made of steel. The insert holder 22 is configured to rotate in the opposite forward direction D. F and backward D R The insert holder 22 has a holder longitudinal axis B that defines a length B. The insert holder 22 is elongated along the holder longitudinal axis B. According to some embodiments of the present subject matter, the cutting tool 20 and the insert holder 22 may be coaxial with one another. It is noted that two elements (e.g., the cutting tool 20 and the insert holder 22 in the present case) are coaxial with one another if their longitudinal axes coincide (are aligned with one another).

[0049] It should be further noted that use of the terms "forward" and "rearward" throughout this specification and claims refers to relative positions to the left and right in Figures 4 and 6a-6b, respectively, in the direction of the holder longitudinal axis B. Generally, the forward direction is toward the cutting insert 24.

[0050] The insert holder 22 is additively manufactured. The insert holder 22 is integrally formed to have a unitary, unitary structure. As used herein, an article is said to have a "unitary, unitary structure" when it results from an additive manufacturing process, even if two or more materials are used during the additive manufacturing of the article.

[0051] It should be noted that the use of the term "additive manufacturing" throughout the specification and claims refers to processes used to create three-dimensional objects in which multiple layers of material are formed to create an object. Examples of such processes include, but are not limited to, selective laser sintering (SLM), selective laser sintering (SLS), direct metal laser sintering (DMLS), fused deposition modeling (FDM), and 3D printing.

[0052] 1-2, the insert holder 22 includes a holder front end surface 28 and a holder rear end surface 30 opposite the holder front end surface 28. The holder front end surface 28 is located at a front end 32 of the insert holder 22. The holder rear end surface 30 is located at a rear end 34 of the insert holder 22. The holder rear surface 30 may be flat. A holder longitudinal axis B may intersect the holder front surface 28 and the holder rear surface 30. The insert holder 22 further includes a holder outer peripheral surface 36 extending between the holder front end surface 28 and the holder rear end surface 30. The holder outer peripheral surface 36 extends about the holder longitudinal axis B.

[0053] Returning to FIG. 2 , the insert holder 22 includes a cutting portion 38. The cutting portion 38 is located at the front end 32 of the insert holder 22. The cutting portion 38 includes an insert pocket 42 that receives the cutting insert 24. According to some embodiments of the present subject matter, the insert pocket 42 may be located at the intersection between the holder peripheral surface 36 and the holder front end face 28. In the assembled position of the cutting tool 20, the cutting insert 24 may be releasably retained within the insert pocket 42.

[0054] According to some embodiments of the present subject matter, the cutting portion 38 may include a plurality of grooves 44 recessed into the holder outer circumferential surface 36. The plurality of grooves 44 may extend helically about the holder longitudinal axis B. The cutting portion 38 has a cutting portion length LC measured in the direction of the holder longitudinal axis B.

[0055] The insert holder 22 includes a shank portion 46 extending rearwardly from the cutting portion 38. The shank portion 46 includes a means for attaching the insert holder 22 to a tool holder (not shown). Specifically, the shank portion 46 is configured to locate in a tool receiving recess of the tool holder and to be releasably fastened therein. The insert holder 22 has a bounding plane D oriented perpendicular to the holder longitudinal axis B. The bounding plane D bounds the cutting portion 38 and the shank portion 46. The shank portion 46 has a shank portion length LS measured in the direction of the holder longitudinal axis B. According to some embodiments of the present subject matter, the shank portion length LS can be longer than the cutting portion length LC.

[0056] 4 and 5a-5b, the holder outer peripheral surface 36 at the shank portion 46 includes a shank radial centering surface 48. The shank portion 46 is designed to be inserted into a recess in the tool holder. The shank radial centering surface 48 serves to ensure accurate radial alignment of the insert holder 22 within the tool holder. According to some embodiments of the subject matter of the present application, the shank radial centering surface 48 may be cylindrical or conical about the holder longitudinal axis B. Preferably, the shank radial centering surface 48 may be cylindrical about the holder longitudinal axis B. As shown in FIG. 7, the cylindrical shank radial centering surface 48 has a shank diameter DS. The shank radial centering surface 48 may extend the entire axial length of the shank portion 46 (i.e., from the holder rear end face 30 to the cutting portion 38).

[0057] According to some embodiments of the subject matter of the present application, the holder outer peripheral surface 36 at the shank portion 46 may include a shank flat surface 50. The shank flat surface 50 provides a fastening means and transmits torque from the tool holder to the insert holder 22. The shank flat surface 50 may be flat and oriented parallel to the holder longitudinal axis B. The shank flat surface 50 may intersect the shank radial centering surface 48. Unlike the shank radial centering surface 48, the shank flat surface 50 may be spaced apart from the holder rear end surface 30 and the cutting portion 38. The shank flat surface 50 may be elongated in the direction of the holder longitudinal axis B. It should be noted that the insert pocket 42 and the plurality of grooves 44 may be on one side of the bounding plane D, and the shank radial centering surface 48 and the shank flat surface 50 may be on the other side of the bounding plane D.

[0058] According to some embodiments of the present subject matter, the holder peripheral surface 36 may include a holder intermediate surface 52 oriented transversely to the holder longitudinal axis B. The holder intermediate surface 52 may extend radially outward from the shank portion 46 to the cutting portion 38. The holder intermediate surface 52 may extend around a full 360° angular extension of the holder longitudinal axis B. The holder intermediate surface 52 may be contained within a bounding plane D. The holder intermediate surface 52 may include a shank axial abutment surface 54 oriented perpendicular to the holder longitudinal axis B. In particular, the shank axial abutment surface 54 may define the bounding plane D.

[0059] The wall of the shank portion 46 includes one or more weight-reducing voids 66 (further referred to below as "hollow through recesses 66") that reduce the overall weight of the insert holder 22. As explained further below, the shank portion 46 is hollow, and the voids 66 connect the inner wall surface 60 of the hollow shank portion 46 to its outer surface.

[0060] 6a and 6b, the insert holder 22 includes a weight-reduction cavity 56 formed within the insert holder 22. Stated another way, the weight-reduction cavity 56 is enclosed within the insert holder 22. Thus, the insert holder 22 is hollow. The weight-reduction cavity 56 is designed to reduce the weight of the insert holder 22. As will be explained further below, the reduction in weight of the weight-reduction cavity 56 is achieved by providing one or more voids 66 along the length of the insert holder 22, thereby reducing the amount of material used to form the insert holder 22.

[0061] Weight reduction cavity 56 includes a hollow chamber 58. Hollow chamber 58 is enclosed within insert holder 22. Hollow chamber 58 has a central chamber axis F. Hollow chamber 58 has a hollow chamber length L measured in the direction of holder longitudinal axis B. According to some embodiments of the present subject matter, hollow chamber length L may be greater than half of shank portion length LS. Chamber central axis F may be coincident with holder longitudinal axis B.

[0062] According to some embodiments of the present subject matter, hollow chamber 58 may be completely enclosed within shank portion 46. In other words, hollow chamber 58 is located within shank portion 46 and not within cutting portion 38. Hollow chamber 58 is axially oriented in the forward direction D. F 46. ​​It should be noted that the weight reduction cavity 56 is located entirely within the shank portion 46 and not entirely within the cutting portion 38 (specifically, the bounding plane D).

[0063] According to some other embodiments of the subject matter of the present application, the hollow chamber 58 may not open to the holder rear surface 30. That is, the hollow chamber 58 may not open to the rear direction D. R In other words, the hollow chamber 58 may be spaced apart from the holder rear face 30.

[0064] See in particular FIG. 6a. The hollow chamber 58 includes a chamber inner wall surface 60. The hollow chamber 58 may be defined by the chamber inner wall surface 60. Generally, the chamber inner wall surface 60 faces inward (i.e., faces toward the chamber central axis F). According to some embodiments of the subject matter of the present application, the chamber inner wall surface 60 may include two opposing chamber end surfaces 62 and a chamber outer circumferential surface 64 extending between the two opposing chamber end surfaces 62. One or both of the two chamber end surfaces 62 may be inclined inward (e.g., have a conical shape) toward the chamber central axis F with respect to the printing direction (typically, the printing direction is parallel to the holder longitudinal axis B). This makes printing easier compared to when the chamber end surface 62 (which requires a support structure) is flat and perpendicular to the printing direction. The chamber outer circumferential surface 64 may extend around the chamber central axis F. That is, the chamber outer periphery 64 may define a boundary for the hollow chamber 58 in a radial direction (i.e., relative to the chamber central axis F). The chamber outer periphery 64 may be cylindrical about the chamber central axis F. The cylindrical chamber outer periphery 64 has a chamber diameter DC. With reference to FIG. 7, the chamber diameter DC may be greater than one-quarter the shank diameter DS and less than three-quarters the shank diameter DS. The chamber diameter DC may be equal to one-half the shank diameter DS.

[0065] The weight-reducing cavity 56 includes a plurality of cavity through recesses 66. Each cavity through recess 66 extends along a central recess axis C. Advantageously, the plurality of cavity through recesses 66 further reduce the weight of the insert holder 22. Additionally, the plurality of cavity through recesses 66 provide a path for unprinted powder to exit the cavity chamber 58. According to some embodiments of the present subject matter, each of the cavity through recesses 66 can include an inner recess wall surface 68 that extends about the central recess axis C.

[0066] See Fig. 7. The plurality of cavity through recesses 66 open into the chamber inner wall surface 60 to form a plurality of interior recess openings 70. According to some embodiments of the present subject matter, the plurality of cavity through recesses 66 may open into the cylindrical chamber outer peripheral surface 64 to form a plurality of interior recess openings 70. In other words, the plurality of interior recess openings 70 may be located in the cylindrical chamber outer peripheral surface 64.

[0067] The plurality of cavity through recesses 66 open into the shank radial centering surface 48 to form a plurality of outer recess openings 72. In other words, the plurality of outer recess openings 72 may be located in the shank radial centering surface 48. As shown in FIG. 5a, the plurality of outer recess openings 72 (preferably the entire plurality of cavity through recesses 66) may be located within the axial dimension of the shank planar surface 50.

[0068] According to some embodiments of the present subject matter, the recess central axis C may extend orthogonally about the holder longitudinal axis B. The recess central axis C may extend radially (i.e., relative to the holder longitudinal axis B). Further, in a cross-section taken at a radial plane that is orthogonal to the holder longitudinal axis B and intersects the plurality of cavity through-recesses 66 (i.e., FIG. 7 ), each cavity through-recess 66 may extend linearly along the recess central axis C.

[0069] Now, please refer back to FIG. 5a. According to some embodiments of the subject matter of the present application, each cavity through recess 66 may be non-cylindrical. Each cavity through recess 66 may include two opposing through recess ends 74. The two through recess ends 74 may be located along the recess inner wall surface 68 between the respective inner recess opening 70 and the respective outer recess opening 72. The two through recess ends 74 may be opposite each other in a view along the recess central axis C. Each cavity through recess 66 may include an elongated through recess intermediate portion 76, which extends lengthwise between the two opposing through recess ends 74 in a direction along the holder longitudinal axis (B). Thus, each cavity through recess 66 may be elongated and form a through groove. The through groove may have a slit-like configuration. Such an elongated cavity through recess 66 may have a corresponding elongated inner recess opening 70 and outer recess opening 72.

[0070] According to some embodiments of the present subject matter, for a given one of the plurality of cavity through recesses 66, one of the two through recess ends 74 may be closer to the cutting portion 38 than the other of the two through recess ends 74. Thus, as shown in FIG. 5a, the two through recess ends 74 may be axially spaced apart from one another along the holder longitudinal axis B and may include an axially forward through recess end 74f and an axially rearward through recess end 74r. Furthermore, in some embodiments, the corresponding through recess intermediate portion 76 may follow a helical path, such that the two through recess ends 74f, 74r may also be circumferentially spaced apart from one another.

[0071] According to some embodiments of the present subject matter, the plurality of cavity through recesses 66 may be angularly spaced (preferably evenly) about the holder longitudinal axis B. Preferably, the plurality of cavity through recesses 66 may include N cavity through recesses 66, where N is a positive integer satisfying the condition 5≦N≦9. In the illustrated non-limiting example, N is equal to 7.

[0072] According to some embodiments of the subject matter of the present application, the plurality of cavity through recesses 66 may extend helically about the holder longitudinal axis B. Each helically extending cavity through recess 66 has a recess twist angle θ. The recess twist angle θ may be greater than or equal to 20° and less than or equal to 40°. Preferably, the recess twist angle θ may be greater than or equal to 25° and less than or equal to 35°. Still preferably, the recess twist angle θ may be equal to 30°. Returning to FIG. 4, the plurality of helical grooves 44 may extend helically in the same sense as the plurality of helically extending cavity through recesses 66.

[0073] According to some embodiments of the subject matter of the present application, the insert holder 22 may include a plurality of shank support members 78. The plurality of cavity through recesses 66 may be angularly spaced apart by the plurality of shank support members 78. Each circumferentially adjacent pair of cavity through recesses 66 may be spaced apart by a respective shank support member 78. Thus, in the circumferential direction of the shank radial centering surface 48, the plurality of cavity through recesses 66 may be spaced apart from one another by the shank support members 78. In general, the plurality of shank support members 78 and the plurality of cavity through recesses 66 may alternate with one another along the shank radial centering surface 48 about the holder longitudinal axis B. The number of support members 78 may match the number of cavity through recesses 66 (or be one less if a shank flat surface, described below, is present). The plurality of support members 78 provide the insert holder 22 with sufficient strength and rigidity to perform metal cutting operations. It should be noted that the plurality of shank support members 78 are bounded radially outwardly by the shank radial centering surface 48 .

[0074] See Figures 5A and 5B. According to some embodiments of the present subject matter, the plurality of shank support members 78 may have an elongated, rib-like configuration. The shank radial centering surface 48 of each shank support member 78 may be wider in the circumferential direction (about the holder longitudinal axis B) than the respective outer recess opening 72. In a cross section taken at a radial plane perpendicular to the holder longitudinal axis B and intersecting the plurality of shank support members 78 (i.e., Figure 7), each of the plurality of shank support members 78 may have an annular segment basic shape. That is, the basic shape may be the shape of a segment of an annulus. The basic shape is formed from two opposing wedge (i.e., converging) peripheral edges and two opposing curved peripheral edges. The inner and outer circles of the annulus are not concentric with the shank radial centering surface 48 and the chamber peripheral surface 64. The corners of the segment of the annulus may be curved. Also, in such a view, circumferentially adjacent pairs of shank support members 78 may be spaced apart by a constant recess distance d. The recess distance d may satisfy the condition 1 mm≦d≦4 mm. Note that the recess distance d is equal to the width of the cavity through recess 66 measured in the tangential direction. Still further, in such a view, each shank support member 78 may have an angular range about the holder longitudinal axis B (at the shank radial centering surface 48) that defines a shank support member angle α. The shank support member angle α may depend on the N cavity through recesses and the recess distance d. In this non-limiting example shown, the shank support member angle α may be greater than 30° and less than 50°. Note that in configurations having a helically extending cavity through recess 66, the multiple shank support members 78 may also helically extend about the holder longitudinal axis B.

[0075] As best shown in FIG. 5b, according to some embodiments of the present subject matter, the shank flat surface 50 may intersect the projection path P of at least one of the plurality of cavity through recesses 66 such that at least one of the plurality of cavity through recesses 66 is truncated (i.e., has a shortened length relative to the other cavity through recesses 66). In other words, the plurality of cavity through recesses 66 may include at least one truncated cavity through recess 66a. The projection path P may spiral around the shank portion 46. In some configurations, the plurality of cavity through recesses 66 may include a plurality of truncated cavity through recesses 66a. In this non-limiting example shown, the shank flat surface 50 intersects exactly four cavity through recesses 66, i.e., two on one side of the shank flat surface 50 (i.e., there are exactly four truncated cavity through recesses 66a).

[0076] For each non-shortened cavity through recess 66' (i.e., non-truncated cavity through recess 66a), one of the two through recess ends 74 may be closer to the cutting portion 38 than the holder rear end face 30. The other of the two through recess ends 74 may be closer to the holder rear end face 30 than the cutting portion 38. It is noted that the outer recess openings 72 do not have to be located on the shank flat surface 50. Furthermore, the shank portion 46 radially inward from the shank flat surface 50 may be devoid of any cavity through recess 66, but there may be a means for conveying a cooling fluid (e.g., cooling passages 66). Advantageously, this improves the strength and rigidity of the insert holder 22. It is also noted that the truncation of the cavity through recess 66 may also cause the adjacent shank support member 78 to be truncated.

[0077] According to some embodiments of the present subject matter, the insert holder 22 includes a flat support member 78b. The flat support member 78b may not have a rib-like configuration. The flat support member 78b is angularly located (about the holder longitudinal axis B) between two of the cavity through recesses 66 and incorporates a portion of the shank flat surface 50. It is noted that the plurality of shank support members 78 may not incorporate a shank flat surface 50. The plurality of cavity through recesses 66 may include a plurality of truncated cavity through recesses 66a. The flat support member 78b may be located between two of the truncated cavity through recesses 66a.

[0078] Along the cavity chamber length L of the cavity chamber 58, the plurality of cavity through recesses 66 occupy between 10% and 40% of the surface area of ​​the shank radial centering surface 48. Thus, along the cavity chamber length L of the cavity chamber 58, the shank support member 78 occupies well over half of the surface area of ​​the shank radial centering surface 48, helping to ensure the rigidity of the shank portion 46. Removing this percentage of material provides a meaningful weight reduction (and material savings) within the insert holder 22 without compromising the rigidity of the insert holder. It should also be understood that for the above percentage ranges, the shank flat surface 50, if present, is not considered part of the shank radial centering surface 48.

[0079] 11, according to some embodiments of the present subject matter, the insert holder 22 may include a cooling conduit 80. The cooling conduit 80 serves to supply cooling fluid to the cutting region. The cooling conduit 80 may include a plurality of cooling passages 82. Each cooling passage 82 has a passage inlet 84 and a passage outlet 86 in fluid communication with each other. Each passage inlet 84 may be located at the holder rear end face 30 or the holder outer peripheral surface 36 at the shank portion 46. Preferably, each passage inlet 84 may be located at the holder rear end face 30. Returning to FIG. 7, each cooling passage 82 may pass through a respective shank support member 78. That is, each cooling passage 82 may be at least partially enclosed within a respective shank support member 78. It should be noted that the entire cooling conduit 80 (including the plurality of cooling passages 82) may be spaced apart from the weight reduction cavity 56.

[0080] The cooling conduit 80 may include a cooling tank 88. As shown in FIG. 6a, the cooling tank 88 may be enclosed within the insert holder 22 in front of the hollow chamber 58. The cooling tank 58 may include an inner tank wall 90. Each passageway outlet 86 may be located in the inner tank wall 90. The coolant may reach the cutting area from the cooling tank 88 through the cooling outlet passageways 92.

[0081] Another aspect of the invention relates to a tool assembly. The tool assembly includes a tool holder having a tool front face. The tool holder includes a tool receiving recess recessed into the tool front face. The tool receiving recess includes a recess abutment surface. According to some embodiments of the present subject matter, a shank portion 46 is located within the tool receiving recess and may be releasably fastened within the tool receiving recess. A shank radial centering surface 48 may abut the recess abutment surface. A shank axial abutment surface 54 may abut the tool front face.

[0082] Although the subject matter of the present application has been described in some detail, it should be understood that various changes and modifications can be made without departing from the spirit or scope of the invention as hereinafter claimed.

[0083] For example, if the recess twist angle θ is large enough, the shank flat surface 50 can intersect the projection path P of at least one of the plurality of cavity through recesses such that said at least one of the plurality of cavity through recesses 66 is interrupted. Note that an "interrupted" cavity through recess 66 is one that extends non-continuously between two through recess ends 74. That is, such a cavity through recess 66 is formed from two or more sub-recesses that lie on the same projection path P.

Claims

1. an insert holder (22) elongated along a holder longitudinal axis (B), The holder longitudinal axis (B) is oriented in the opposite forward direction (D Ｆ ) and backward (D Ｒ ) is defined, said insert holder (22) being integrally formed to have a single, unitary structure; a holder front end surface (28), a holder rear end surface (30), and a holder outer peripheral surface (36) extending between the holder front end surface (28) and the holder rear end surface (30) and extending around the holder longitudinal axis (B); a cutting portion (38) having an insert pocket (42) for releasably retaining a cutting insert (24), the cutting portion (38) being located at the front end (32) of the insert holder (22); a shank portion (46) extending rearward from the cutting portion (38), the holder outer peripheral surface (36) at the shank portion (46) including a shank radial centering surface (48); a weight reduction cavity (56); The weight reduction cavity (56) a hollow chamber (58) enclosed within the insert holder (22), the hollow chamber (58) having an inner chamber wall surface (60); a plurality of hollow through recesses (66); The plurality of cavity through-recesses (66) open to (i) the chamber inner wall surface (60) and (ii) the shank radial centering surface (48), forming a plurality of inner recess openings (72) with the chamber inner wall surface and a plurality of outer recess openings (70) with the shank radial centering surface (48).

2. The insert holder (22) of claim 1, wherein the hollow chamber (58) is surrounded only by the shank portion (46).

3. The insert holder (22) of claim 1, wherein the hollow chamber (58) is spaced from the holder rear face (30).

4. Each of said hollow through recesses (66) is a recess inner wall surface (68) extending around a recess central axis (C); two opposite through recess ends (74) located along the recess inner wall surface (68) between each of the inner recess openings (70) and each of the outer recess openings (72); an elongated through recess intermediate portion (76); 2. The insert holder (22) of claim 1, wherein the elongated through-recess intermediate portion (76) extends longitudinally between the two opposing through-recess end portions (74), such that each hollow through-recess (66) is elongated in a direction along the holder longitudinal axis (B).

5. 5. The insert holder (22) of claim 4, wherein for a given one of the plurality of hollow through recesses (66), one of the two through recess ends (74) is closer to the cutting portion (38) than the other of the two through recess ends (74).

6. 2. The insert holder (22) of claim 1, wherein the shank radial centering surface (48) is cylindrical or conical about the holder longitudinal axis (B).

7. The plurality of cavity through-recesses (66) comprises N cavity through-recesses (66), 2. The insert holder (22) of claim 1, wherein N is a positive integer satisfying the condition 5≦N≦9.

8. 2. The insert holder (22) of claim 1, wherein the plurality of hollow through recesses (66) are angularly spaced about the holder longitudinal axis (B).

9. 9. The insert holder (22) of claim 8, wherein the plurality of cavity through-recesses (66) are angularly spaced apart by a plurality of shank support members (78), and each circumferentially adjacent pair of the cavity through-recesses (66) is spaced apart by a respective shank support member (78).

10. 10. The insert holder (22) of claim 9, wherein the shank radial centering surface (48) on each shank support member (78) is circumferentially wider than each outer recess opening (72).

11. The holder outer peripheral surface (36) in the shank portion (46) has a shank flat surface (50), 10. The insert holder (22) of claim 9, wherein the shank flat surface (50) is oriented parallel to the holder longitudinal axis (B) and intersects the shank radial centering surface (48).

12. 12. The insert holder (22) of claim 11, wherein the shank flat surface (50) intersects the projection path (P) of at least one of the plurality of cavity through-recesses (66) such that the plurality of cavity through-recesses (66) comprises at least one truncated cavity through-recess (66a).

13. The insert holder (22) is provided with a cooling conduit (80); the cooling conduit (80) comprises a plurality of cooling passages (82); Each of the cooling passages (82) has a passage inlet (84) and a passage outlet (86) in fluid communication with each other; The insert holder (22) of claim 8, wherein each said cooling passage (82) passes through a respective said shank support member (78).

14. 2. The insert holder (22) of claim 1, wherein the plurality of hollow through recesses (66) extend helically about the holder longitudinal axis (B).

15. Each of the spirally extending cavity-through recesses (66) has a recess helix angle (θ); The insert holder (22) of claim 14, wherein the recess helix angle (θ) is greater than or equal to 20° and less than or equal to 40°.

16. The cutting portion (38) has a cutting portion length (LC), The shank portion (46) has a shank portion length (LS), Both the cutting portion length (LC) and the shank portion length (LS) are measured in the direction of the holder longitudinal axis (B); The insert holder (22) of claim 1, wherein the shank portion length (LS) is greater than the cutting portion length (LC).

17. The hollow chamber (58) has a hollow chamber length (L); 2. The insert holder (22) of claim 1, wherein along the cavity chamber length (L) of the cavity chamber (58), the plurality of cavity through-hole recesses (66) occupy between 10% and 40% of the surface area of ​​the shank radial centering surface (48).

18. An insert holder (22) according to claim 1; a cutting insert (24) having at least one cutting edge (26) releasably retained within the insert pocket (42); A cutting tool (20) comprising:

19. 20. The cutting tool (20) of claim 18, wherein the cutting tool (20) is a rotary cutting tool (20) rotatable about the holder longitudinal axis (B).

20. an insert holder (22) elongated along a holder longitudinal axis (B), The holder longitudinal axis (B) is oriented in the opposite forward direction (D Ｆ ) and backward (D Ｒ ) is defined, said insert holder (22) being integrally formed to have a single, unitary structure; a holder front end surface (28), a holder rear end surface (30), and a holder outer peripheral surface (36) extending between the holder front end surface (28) and the holder rear end surface (30) and extending around the holder longitudinal axis (B); a cutting portion (38) having an insert pocket (42) for releasably retaining a cutting insert (24), the cutting portion (38) being located at the front end (32) of the insert holder (22); a hollow shank portion (46) extending rearwardly from the cutting portion (38); The hollow shank portion (46) a shank radial centering surface (48) that is a part of the holder outer peripheral surface (36); a shank flat surface (50) that is also part of the holder outer peripheral surface (36), that is oriented parallel to the holder longitudinal axis (B) and that intersects the shank radial centering surface (48); a plurality of hollow through recesses (66) connecting the inner wall surface (60) of the hollow shank portion (46) to the shank radial centering surface (48); an insert holder (22) having

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