Cutting insert with clamping bore with coolant inlet, insert holder and cutting tool

Abstract

A cutting tool with a coolant system having a cutting insert, a cutting insert, and an insert holder. The cutting insert (20) has a first insert bore (60) having a first bore peripheral surface (64) and an entry gap (68) recessed therein. When the cutting tool is assembled, the fastening element clamps the first bore peripheral surface and seals the first insert bore, thereby releasably securing the cutting insert to the insert holder and allowing a fluid connection between the insert holder and the cutting insert.

Description

Technical Field

[0001] The subject matter of the present application relates to coolant systems in grooving and parting off metalworking tools, and in particular to coolant systems in cutting inserts that are releasably secured to an insert holder using a fastening member. Background Art

[0002] In the field of metal machining, it is desirable to provide coolant to the cutting edge of a cutting insert, and preferably to provide the coolant close to and directed toward the cutting edge of a cutting tool. In grooving and parting operations, the thin cutting blades used in the machining operation cause complications when providing coolant to the cutting edge of a cutting insert.

[0003] While there are many widths of blades depending on the application, the most preferred blades are as thin as possible to reduce waste.

[0004] Such complications are common in blade-shaped or plate-shaped materials with a cutting width of 2-4 mm (2-4 mm is the most common size on the market, although there are slightly thinner and slightly thicker sizes; although the cutting width refers to the width of the cutting insert edge, the corresponding blades configured to accommodate such cutting inserts have a typical width of 1.4-3.6 mm), especially for blades that are usually reversible (where coolant input can come from opposite sides). Many solutions have been tried as follows.

[0005] A known solution in the art is to supply coolant to the cutting blade through a blade holder while fastening the blade to the blade holder with a screw. The coolant outlet of the blade holder and the coolant inlet of the cutting blade are aligned with each other in a predetermined position away from the screw, as seen in CN1,757,471.

[0006] Another solution is to use screws to seal the coolant passages, thereby ensuring that coolant is provided to the cutting insert, as seen in DE 3,434,653 and JP 6,880,856.

[0007] It is also known in the art to use screws with internal channels to facilitate the passage of coolant to the cutting insert, as seen in EP 2,745,963. Summary of the invention

[0008] According to a first aspect of the subject matter of the present application, a cutting insert is provided, which has a blade width W and includes: a first blade side surface and a second blade side surface opposite to each other; a peripheral blade surface, the peripheral blade surface connecting the first blade side surface and the second blade side surface; a first insert seat, the first insert seat being located at the intersection of the first blade side surface, the second blade side surface and the peripheral blade surface; a first blade inner hole, the first blade inner hole opening outwardly to the first blade side surface and the second blade side surface; a first blade inlet; and a first blade outlet, the first blade outlet opening outwardly toward the first insert seat and connected to the first blade inlet fluid; the first blade inner hole having a first blade inner hole axis, ... The hole axis defines a radially outward direction extending radially outward from the first blade inner hole axis and a radially inward direction opposite to the radially outward direction; the first blade inner hole includes: a first inner hole edge, which is formed at the intersection of the first blade side surface and the first blade inner hole; a second inner hole edge, which is formed at the intersection of the second blade side surface and the first blade inner hole; and a first inner hole peripheral surface, which connects the first inner hole edge and the second inner hole edge and includes a first inner hole adjacent sub-surface; wherein: the first inner hole peripheral surface also includes an entry gap that is recessed from the first blade inner hole axis farther than the first inner hole adjacent sub-surface; and the entry gap is connected to the first blade inlet fluid.

[0009] Some advantages of such a cutting insert allow, for example, a commercially available clamping screw to secure the cutting insert to a blade holder without any additional components such as a rubber O-ring or a metal annular sealing element, while also sealing the cutting insert to prevent coolant leakage and allowing a fluid connection between the cutting insert and the blade holder. In addition, it will be understood that it is preferred to have fewer components to be provided, fewer components that may fall out, and a more compact construction (e.g., less lateral extension from the blade). In addition, according to the preferred features below, such a blade can be used with a fluid connection between the cutting insert and the blade holder when the first blade side surface or the second blade side surface is adjacent to the blade holder (i.e., the cutting insert is indexable).

[0010] According to a second aspect of the subject matter of the present application, a cutting tool is provided, which includes: a blade holder; a fastening element; a cutting blade according to the first aspect, which is releasably fixed to the blade holder; and a cutting insert, which is releasably fixed to the cutting blade; the blade holder includes: a holder fastening surface, which is perpendicular to a longitudinal plane of the holder fastening surface, and the longitudinal plane of the holder fastening surface contains a longitudinal axis of the holder fastening surface; a first holder inner hole, which is open to the outside to the holder fastening surface; and a holder outlet, which is open to the outside to the holder fastening surface and is fluidically connected to the holder inlet; the fastening element includes: a fastening element engagement portion; and a fastening element head, which includes a fastening element abutting surface; the second blade side surface is adjacent to the holder fastening surface; and the fastening element clamps the cutting blade to the blade holder via the first blade inner hole and the first holder inner hole, and seals the first blade inner hole at the edge of the first inner hole.

[0011] Such a cutting tool simplifies the problem of supplying coolant to the cutting insert, with minimal leakage and the above-mentioned advantages of fewer parts and compact construction. In addition, according to the preferred features below, such a blade holder can allow the cutting blade to abut the holder fastening surface with the first blade side surface or the second blade side surface. Such embodiments are preferred because they allow a fluid connection between the cutting blade and the blade holder when the first blade side surface or the second blade side surface abuts the holder fastening surface.

[0012] It is understood that the above is an overview 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 insert and / or an insert holder and / or a cutting tool.

[0013] The blade width W may satisfy the following condition: 1.4 mm ≤ W ≤ 3.6 mm. It will be appreciated that for compact cutting tools, in particular with internal coolant and blades for cutting, there are particular advantages, such as minimal waste (material removed from the workpiece) and close shoulder cutting capabilities. In larger configurations, there is room for additional components, so indexability of the cutting blade is not necessary. In addition, in such thin cutting blades, it is difficult to face internal configurations modified for other components (e.g., the internal thread of the first blade inner hole requires a minimum thickness).

[0014] The first inner bore abutment sub-surface may taper conically inwardly from the first insert side surface toward the first insert inner bore axis.Such a conical taper may reduce the protrusion of the fastening element relative to the cutting tool while cooperating with the fastening element to seal the cutting insert.

[0015] The first inner bore abutment sub-surface may include a first entry abutment sub-surface located between the entry gap and the first inner bore edge.Having such a surface may improve the sealing ability of the fastening element.

[0016] The first inner bore abutment sub-surface and the first entry abutment sub-surface may conically taper inwardly from the first insert side surface toward the first insert inner bore axis.

[0017] An imaginary bisector plane may pass through the middle between the first blade side surface and the second blade side surface; the first inner hole adjacent sub-surface is located between the imaginary bisector plane and the first inner hole edge; the first inner hole peripheral surface may also include a second inner hole adjacent sub-surface located between the imaginary bisector plane and the second inner hole edge; and the entry gap is open outward to the first inner hole adjacent sub-surface and the second inner hole adjacent sub-surface.

[0018] The first bore abutment subsurface may taper conically inwardly from the first insert side surface toward the first insert bore axis to an imaginary bisector plane; and the second bore abutment subsurface may taper conically inwardly from the second insert side surface toward the first insert bore axis to an imaginary bisector plane.

[0019] The first inner bore abutment sub-surface and the second inner bore abutment sub-surface may taper conically at a taper angle α relative to the insert inner bore axis B. The taper angle α may satisfy the following condition: 40°≤α≤140°.

[0020] The cone angle α may also satisfy the following condition: 50°≤α≤90°.

[0021] The cone angle α may also satisfy the following condition: 55°≤α≤70°, which is theoretically considered to be optimal for both coolant sealing and fixing the insert to the insert holder.

[0022] The first inner bore abutment subsurface may include a first entry abutment subsurface located between the entry gap and the first inner bore edge; and the second inner bore abutment subsurface may include a second entry abutment subsurface located between the entry gap and the second inner bore edge.

[0023] The first bore abutment subsurface and the first entry abutment subsurface may taper conically inwardly from the first insert side surface toward the first insert bore axis; and the second bore abutment subsurface and the second entry abutment subsurface may taper conically inwardly from the first insert side surface toward the first insert bore axis.

[0024] The first inner bore abutment sub-surface may include a first entry abutment sub-surface located between the entry gap and the first inner bore edge; and the fastening element abutment surface abuts against the first entry abutment sub-surface.

[0025] The fastening element may be flush with the first blade side surface or recessed relative to the first blade side surface.

[0026] The retainer fastening surface may be mirror-symmetrical with respect to an imaginary retainer fastening surface longitudinal plane.

[0027] The first retainer inner hole and the retainer outlet can be spaced apart from each other and are connected via a retainer groove fluid recessed on the retainer fastening surface. Separating the first retainer inner hole from the retainer outlet allows each element to function optimally. It will be understood that the first retainer inner hole and the retainer outlet of the combination known in the art have a more compact design, but preferably, the first retainer inner hole and the retainer outlet are connected by the retainer groove, wherein each element functions in an optimal manner.

[0028] The holder outlet may be positioned closer to the center of the holder fastening surface than the first holder inner hole. This ensures that the fastening element fixes the cutting insert back to the insert holder, which may be advantageous in some embodiments (e.g., embodiments with multiple holder inner holes and insert inner holes).

[0029] An imaginary bisector plane may pass halfway between the first blade side surface and the second blade side surface; the first inner hole adjacent sub-surface is located between the imaginary bisector plane and the first inner hole edge; the first inner hole peripheral surface may also include a second inner hole adjacent sub-surface located between the imaginary bisector plane and the second inner hole edge; the entry gap may be open outward to the first inner hole adjacent sub-surface and the second inner hole adjacent sub-surface; and the cutting blade is fixed to the blade holder in any of the following cases: the second blade side surface is adjacent to the holder fastening surface, and the fastening element engages the first holder inner hole, clamps the first inner hole adjacent sub-surface and seals the first blade inner hole at the first inner hole edge; or the first blade side surface is adjacent to the holder fastening surface, and the fastening element engages the first holder inner hole, clamps the second inner hole adjacent sub-surface and seals the first blade inner hole at the second inner hole edge.

[0030] At the entry gap, the first inner bore abutment subsurface and the second inner bore abutment subsurface may include first entry abutment subsurface and second entry abutment subsurface, respectively; and the fastening element abutment surface abuts against one of the first entry abutment subsurface and the second entry abutment subsurface. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to better understand the present application and to show how it may be implemented in practice, reference will now be made to the accompanying drawings, in which:

[0032] Figure 1 is a perspective view of a cutting portion of a cutting tool in a first configuration according to an embodiment of the present invention (it will be appreciated that the cutting portion will typically have a shank, but as this is a standard component it is not shown or described, and the term "cutting portion" may be omitted hereinafter, with only "cutting tool" or "insert holder" being used, although it is understood that the shank is implicit);

[0033] Figure 2 yes Figure 1 An exploded perspective view of a cutting tool;

[0034] Figure 3 Is in the second configuration of the cutting tool Figure 1 A perspective view of a cutting tool wherein the cutting insert is in contact with Figure 1 secured to the blade holder in a different position (inverted) than the blade;

[0035] Figure 4 yes Figure 1 A side view of a cutting tool;

[0036] Figure 5 yes Figure 1 Cross-sectional view of the cutting tool along line AA;

[0037] Figure 6a yes Figure 1 A perspective view of the cutting insert shown in ;

[0038] Figure 6b yes Figure 6a A side view of a cutting blade;

[0039] Figure 6c yes Figure 6a A top view of a cutting blade;

[0040] Figure 6d yes Figure 6a A bottom view of a cutting blade;

[0041] Figure 6e yes Figure 6a A rear view of a cutting blade;

[0042] Figure 7 yes Figure 1 A perspective view of a blade holder shown in ;

[0043] Figure 8 yes Figure 7 A side view of a blade holder;

[0044] Fig. 9 yes Figure 1 A perspective view of the fastening element shown in ;

[0045] Fig.10 yes Fig. 9 Side view of the fastening element.

[0046] It will be appreciated that, for simplicity and clarity of illustration, the elements shown in the figures are not necessarily drawn to scale. For example, the dimensions of some elements may be exaggerated relative to other elements for clarity, or several physical components may be included in one functional block or element. In addition, reference numerals may be repeated in the figures to indicate corresponding or similar elements where deemed appropriate. DETAILED DESCRIPTION

[0047] In the following description, various aspects of the subject matter of the present application will be described. For the purpose of explanation, specific configurations and details are described in sufficient detail to provide a thorough understanding of the subject matter of the present application. However, it will also be apparent to those skilled in the art that the subject matter of the present application can be practiced without the specific configurations and details set forth herein.

[0048] First note Figures 1 to 5 , shows a cutting tool 1 having a blade holder 100, a cutting blade 20 releasably fixed to the blade holder 100 by a fastening element 150, and a cutting insert 10 releasably fixed to the cutting blade 20. Preferably, the cutting insert 10 is resiliently fixed to the cutting blade 20. Such a cutting tool 1 is typically used for grooving and parting operations, and is characterized by a thin cutting blade 20.

[0049] Notice Figures 6a to 6e The cutting insert 20 has a first insert side surface 22 and an opposite second insert side surface 24. A peripheral insert surface 30 connects the first insert side surface 22 and the second insert side surface 24.

[0050] The cutting insert 20 is preferably plate-shaped, having an elongated first insert side surface 22 and a second insert side surface 24. In such a case, the peripheral insert surface 30 is elongated along the first insert side surface 22 and the second insert side surface 24, and is thinner (having a much smaller dimension) in a direction perpendicular to the insert side surfaces 22, 24.

[0051] In some embodiments, the imaginary bisector plane P passes midway between the first blade side surface 22 and the second blade side surface 24. The imaginary bisector plane P is also preferably but optionally parallel to the first blade side surface 22 and the second blade side surface 24.

[0052] In some embodiments, the peripheral blade surface 30 may have opposing top and bottom blade surfaces 32 , 34 , and opposing rear and front blade surfaces 36 , 38 connecting the top and bottom blade surfaces 32 , 34 .

[0053] The first insert seat 50 is located at the intersection of the first blade side surface 22, the second blade side surface 24 and the peripheral blade surface 30. Specifically, the first insert seat 50 can be located at the intersection of the first blade side surface 22, the second blade side surface 24, the top blade surface 32 and the front blade surface 38.

[0054] The blade width W is measurable between the first blade side surface 22 and the second blade side surface 24. In some embodiments, the blade width W may be uniform along the entire length of the cutting insert 20. In embodiments with a non-uniform blade width W, the value of the blade width W is measured near the first insert seat 50.

[0055] The first insert clamping inner hole 60 ("first insert inner hole 60") has a first insert inner hole axis B and opens outward to the first insert side surface 22 and the second insert side surface 24. The radially outward direction Ro is defined as extending radially outward from the first insert inner hole axis B, and the radially inward direction Ri is defined as being opposite to the radially outward direction Ro. The first insert inner hole axis B may preferably but optionally be perpendicular to the imaginary bisecting plane P.

[0056] The first insert inner hole 60 has a first inner hole edge 62a and a second inner hole edge 62b. The first inner hole edge 62a is formed at the intersection of the first insert side surface 22 and the first insert inner hole 60. The second inner hole edge 62b is formed at the intersection of the second insert side surface 24 and the first insert inner hole 60.

[0057] The first inner hole peripheral surface 64 connects the first inner hole edge 62a and the second inner hole edge 62b. The first inner hole peripheral surface 64 has a first inner hole adjacent sub-surface 66a. Figure 6a As shown in FIG. 6 , the first inner bore abutment sub-surface 66a faces in the same general direction as the first insert side surface 22. Preferably, the first inner bore peripheral surface 64 is unthreaded.

[0058] The first inner hole peripheral surface 64 preferably but optionally also has a second inner hole adjacent sub-surface 66b. Figure 6b , the second inner hole abutment subsurface 66b faces the same basic direction as the second insert side surface 24. In this case, the first inner hole abutment subsurface 66a is located between the imaginary bisector plane P and the first insert side surface 22, and the second inner hole abutment subsurface 66b is located between the imaginary bisector plane P and the second insert side surface 24.

[0059] The first inner bore peripheral surface 64 is shaped in a manner that allows the fastening element 150 to be clamped directly against it. For example, the first inner bore abutment sub-surface 66a and the second inner bore abutment sub-surface 66b may be countersunk relative to the first side surface 22 and the second side surface 24, respectively. This allows the fastening element 150 to be constrained to the first insert inner bore 60, resulting in a smaller protrusion of the fastening element 150 relative to the cutting tool 1.

[0060] The first inner hole peripheral surface 64 also has an entry gap 68, which is recessed from the first insert inner hole axis B farther than the first inner hole abutment sub-surface 66a. In some embodiments, the entry gap 68 can open outwardly to the first inner hole abutment sub-surface 66a. The entry gap 68 can also open outwardly to the second inner hole abutment sub-surface 66b.

[0061] The first inner hole abutment sub-surface 66a may have a first entry abutment sub-surface 70a located at the entry gap 68. Specifically, the first entry abutment sub-surface 70a is located between the entry gap 68 and the first inner hole edge 62a. The first entry abutment sub-surface 70a is recessed further relative to the first insert inner hole axis B than the rest of the first inner hole abutment sub-surface 66a.

[0062] The second inner hole abutment subsurface 66b may have a second entry abutment subsurface 70b located at the entry gap 68. Specifically, the second entry abutment subsurface 70b is located between the entry gap 68 and the second inner hole edge 62b. The second entry abutment subsurface 70b is recessed further relative to the first insert inner hole axis B than the rest of the second inner hole abutment subsurface 66b.

[0063] In some embodiments, the first bore abutment subsurface 66a may taper conically inwardly from the first insert side surface 22 toward the first insert bore axis B to an imaginary bisector plane P. Similarly, the second bore abutment subsurface 66b may taper conically inwardly from the second insert side surface 24 toward the first insert bore axis B to an imaginary bisector plane P.

[0064] It will be noted that the “from” and “to” language does not require that the first inner hole adjacent sub-surface 66a and the second inner hole adjacent sub-surface 66b intersect any of the following: the first blade side surface 22, the second blade side surface 24 and the imaginary bisector plane P, but in other words, the surfaces “extend between” any of the imaginary bisector plane P, the first blade side surface 22 and the second blade side surface 24.

[0065] As an alternative to the inward conical taper of the first and second inner bore abutment subsurfaces 66a, 66b described and shown above, the first and second inner bore abutment subsurfaces 66a, 66b may feasibly but less preferably have a stepped configuration (not shown).

[0066] In some embodiments, the first inner bore abutment subsurface 66a and the first entry abutment subsurface 70a may taper conically inwardly from the first insert side surface 22 toward the first insert inner bore axis B. In addition, the second inner bore abutment subsurface 66b and the second entry abutment subsurface 70b may taper conically inwardly from the second insert side surface 24 toward the first insert inner bore axis B.

[0067] In some embodiments, Figure 5 As shown in , the first abutment sub-surface 66a and the second abutment sub-surface 66b taper conically with respect to the first insert inner hole axis B at a taper angle α, and the taper angle α satisfies the following conditions: 40°≤α≤140°. Preferably: 50°≤α≤90°. Most preferably: 55°≤α≤70°.

[0068] The first inner hole abutment sub-surface 66a and the second inner hole abutment sub-surface 66b may also be respectively recessed (i.e., set back) relative to the first blade side surface 22 and the second blade side surface 24. Specifically, the first inner hole abutment sub-surface 66a and the second inner hole abutment sub-surface 66b may be recessed relative to the first blade side surface 22 and the second blade side surface 24 in the direction along the first blade inner hole axis B.

[0069] The second inner hole abutment sub-surface 66b may have mirror symmetry with respect to the imaginary bisecting plane P with respect to the first inner hole abutment sub-surface 66a.

[0070] Alternatively, it is possible that there may be no mirror symmetry and the second inner bore abutment sub-surface 66b may be shaped differently than the first inner bore abutment sub-surface 66a.

[0071] In some embodiments, the cutting insert 20 may also have at least one additional insert clamping inner hole 72 ("additional insert inner hole 72") separated from the first insert inner hole 60, which opens outwardly to the first insert side surface 22 and the second insert side surface 24. Each additional insert inner hole 72 has an additional inner hole peripheral surface 74 extending between the first insert side surface 22 and the second insert side surface 24. The additional insert inner hole 72 allows the cutting insert 20 to have better stability in the insert holder 100. Preferably, but optionally, as seen in the figure, given a total of three inner holes, two additional insert inner holes 72 can be provided.

[0072] The additional inner hole peripheral surface 74 is shaped in a manner that allows the fastening element 150 to be clamped directly against it. More particularly, the additional inner hole peripheral surface 74 is countersunk relative to the first insert side surface 22 and / or the second insert side surface 24. This allows the fastening element 150 to be constrained to the additional insert inner hole 72, resulting in a smaller protrusion of the fastening element 150 relative to the cutting tool 1. For example, the additional inner hole peripheral surface 74 may have a double-ended tapered shape that tapers inwardly from the first insert side surface 22 and the second insert side surface 24.

[0073] As in Figure 2 and Figure 6b As best seen in , all of the additional insert bores 72 do not allow coolant to pass therethrough and are used only to secure the cutting insert 20 to the insert holder 100. It will be noted that in some embodiments (not shown), it may be found advantageous that one or more of the additional insert bores 72 also have the same geometry as that shown in the first insert bore 60, as will be discussed below, thereby allowing coolant to pass therethrough. In such embodiments, the first insert bore 60 may alternatively have a securing function, and only one or more of the additional insert bores 72 may be configured to provide coolant. However, it will be appreciated that if two or more bores are used to provide coolant simultaneously, this may be advantageous over a single bore, as the total supply of coolant may be increased.

[0074] Preferably, when the cutting insert 20 has a plurality of internal holes (particularly at least the first insert internal hole 60 and the additional insert internal hole 72), the insert internal holes are located close to the peripheral insert surface 30 and are kept at a distance from each other. Dispersing the plurality of internal holes can allow for improved stability of the fastening of the cutting insert 20 in the insert holder 100.

[0075] The cutting insert 20 also has a first insert coolant inlet 80a ("first insert inlet 80a") and a first insert coolant outlet 82a ("first insert outlet 82a") fluidly connected to the first insert inlet 80a. Figures 5 to 6d As seen in FIG. 1 , the cutting insert 20 also has a second insert coolant inlet 80b (“second insert inlet 80b”) and a second insert coolant outlet 82b (“second insert outlet 82b”) fluidly connected to the second insert inlet 80b. For example, the insert coolant passage 84 may fluidly connect the first insert inlet 80a and the second insert inlet 80b to the first insert outlet 82a and the second insert outlet 82b, as illustrated.

[0076] The first blade outlet 82a and the second blade outlet 82b open outwardly substantially toward the first insert seat 50 to supply coolant to the cutting insert 10 during machining operations. Preferably, but optionally, due to the plate-like shape of the cutting insert 20, the first blade outlet 82a and the second blade outlet 82b open outwardly to the peripheral blade surface 30 near the first insert seat 50. Most preferably, the first blade outlet 82a and the second blade outlet 82b open outwardly to a different one of the top blade surface 32 and the front blade surface 38.

[0077] The entry gap 68 is fluidly connected with the first blade inlet 80a and the second blade inlet 80b. Specifically, the first blade inlet 80a and the second blade inlet 80b can be opened outwardly to the first inner hole peripheral surface 64 at the entry gap 68.

[0078] like Figure 7 and Figure 8 As seen in FIG. 1 , the blade holder 100 has a holder fastening surface 120, a first holder inner bore 122, a holder outlet 132 and a holder inlet 134. The holder fastening surface 120 is perpendicular to a holder fastening surface longitudinal plane M, which contains the holder fastening surface longitudinal axis A. The first holder inner bore 122 opens outwardly to the holder fastening surface 120.

[0079] The retainer fastening surface 120 may preferably be configured to have a first configuration (such as Figure 1 The selective abutment and the first blade side surface 22 in the second configuration of the cutting tool 1 (as seen in Figure 3 The size and shape of the selective adjacency in ).

[0080] For example, the retainer fastening surface 120 may be mirror-symmetrical with respect to an imaginary retainer fastening surface longitudinal plane M. This is a preferred option for realizing the first and second configurations mentioned above. It is worth noting that both configurations allow coolant to pass through the cutting insert 20 .

[0081] The blade holder 100 may also have an opposite front holder surface 102 and a rear holder surface 104, with the peripheral holder surface 106 being located between the two. In such a case, as shown in the figures, the holder fastening surface 120 is preferably located on the front holder surface 102, opposite to the rear holder surface 104.

[0082] The retainer outlet 132 opens outwardly to the retainer fastening surface 120 and is fluidly connected to the retainer inlet 134. For example, Figure 2 and Figure 7As shown in FIG. 1 , the holder coolant passage 138 may connect the holder outlet 132 to the holder inlet 134. In some embodiments, the blade holder 100 may have a plurality of holder outlets 132.

[0083] In some embodiments, the insert holder 100 may also have at least one additional holder inner hole 124 that opens outwardly to the holder fastening surface 120. Having at least one additional holder inner hole 124 may increase the stability of the cutting insert 20 fastened to the insert holder 100.

[0084] In some embodiments, the retainer outlet 132 may be spaced apart from the first retainer inner bore 122, opening outwardly to the retainer fastening surface 120, without overlap between the retainer outlet 132 and the first retainer inner bore 122. In such a case, the retainer outlet 132 and the first retainer inner bore 122 may be fluidly connected via a retainer groove 136 recessed on the retainer fastening surface 120.

[0085] As discussed below, in the assembled cutting tool 1, the holder groove 136 is fluidly connected with the holder outlet 132 and the entry gap 68 of the cutting insert 20. This allows coolant to be supplied from the insert holder 100 to the first insert inlet 80a and the second insert inlet 80b of the cutting insert 20 without compromising the engagement between the first holder inner bore 122 and the fastening element 150.

[0086] In an embodiment where the retainer outlet 132 is separated from the first retainer inner bore 122 and has at least one additional retainer inner bore 124, it is preferred that the first retainer inner bore 122 and the at least one additional retainer inner bore 124 are spaced apart and dispersed from each other, thereby increasing the stability of the cutting insert 20 being fastened to the insert holder 100. Therefore, in such a case, it is preferred that the retainer outlet 132 is located closer to the center C of the retainer fastening surface 120 than the first retainer inner bore 122. It is further preferred that the retainer outlet 132 is located closer to the center C of the retainer fastening surface 120 than the at least one additional retainer inner bore 124. In other words, it is preferred that the first retainer inner bore 122 is located closer to the periphery of the retainer fastening surface 120 than the retainer outlet 132.

[0087] Alternatively, the holder outlet 132 may merge with the first holder bore 122, wherein the first holder bore 122 both engages the fastening element 150 and allows coolant to pass to the cutting insert 20. This may be accomplished, for example, via a groove recessed into the side of the first holder bore 122 (not shown).

[0088] When the cutting tool 1 is assembled, the second insert side surface 24 comes into abutment against the holder fastening surface 120. In addition, the fastening element 150 passes through the first insert bore 60, engages the first holder bore 122, clamps the first bore abutment sub-surface 66a and secures the cutting insert 20 to the insert holder 100. The holder outlet 132 is then fluidly connected with the first insert inlet 80a and the second insert inlet 80b.

[0089] like Figure 5 As best seen in FIG. 1 , the fastening element 150 also serves to seal the first insert inner bore 60 at the first inner bore abutment sub-surface 66 a. Specifically, the fastening element 150 serves two purposes: to releasably secure the cutting insert 20 to the insert holder 100, and to act as a seal while allowing coolant to pass from the insert holder 100 into the cutting insert 20.

[0090] When fastened to the insert holder 100, the fastening element 150 may protrude slightly beyond the cutting insert 20 in a direction parallel to the first insert bore axis B. Specifically, the fastening element 150 may protrude less than 2 mm from the cutting insert 20. Preferably, the fastening element 150 protrudes less than 1 mm from the cutting insert 20. Most preferably, as Figure 5 As seen in FIG. 1 , the fastening element 150 is flush with the cutting insert 20 in the direction of the first insert inner bore axis B or is recessed relative to the cutting insert 20 .

[0091] In some embodiments, the cutting blade 20 can be fixed to the blade holder 100 in different positions. Specifically, the cutting blade 20 can be fixed to the blade holder 100 in a reverse position (such as Figure 3 ) is fixed to the blade holder 100, thereby placing the cutting tool 1 in the second configuration.

[0092] In the first position (such as Figure 1 1 ), the second insert side surface 24 abuts against the retainer fastening surface 120, as discussed above. In the described position, the fastening element 150 engages the first retainer inner bore 122, clamps the first inner bore abutment sub-surface 66a and seals the first insert inner bore 60 at the first inner bore edge 62a. For clarity, the fastening element 150 sealing the first insert inner bore 60 at the first inner bore edge 62a should be understood as the fastening element 150 obstructing or preventing fluid connection between the first insert inner bore 60 and the first inner bore edge 62a.

[0093] In the reverse position (such as Figure 3), the cutting insert 20 can be fixed to the insert holder 100, wherein the first insert side surface 22 abuts against the holder fastening surface 120. In the described position, the fastening element 150 passes through the first insert inner hole 60, engages the first holder inner hole 122, clamps the second inner hole adjacent sub-surface 66b, and seals the first insert inner hole 60 at the second inner hole edge 62b. Then, the holder outlet 132 is fluidly connected with the first insert inlet 80a and the second insert inlet 80b, wherein the fastening element 150 releasably fixes the cutting insert 20 to the insert holder 100 and seals the first insert inner hole 60 at the second inner hole adjacent sub-surface 66b. For the sake of clarity, the fastening element 150 sealing the first insert inner hole 60 at the second inner hole edge 62b should be understood as the fastening element 150 hindering or preventing the fluid connection between the first insert inner hole 60 and the second inner hole edge 62b.

[0094] In both positions, the fastening element 150 acts as a seal, as described above, allowing fluid connection between the first and second blade inlets 80a, 80b and the holder outlet 132.

[0095] Attention Fig. 9 and Fig.10 , the fastening element 150 has a fastening element engagement portion 152 and a fastening element head 154. The fastening element engagement portion 152 is intended to engage with an inner hole machined in the blade holder 100. For example, the engagement between the fastening element engagement portion 152 and the first holder inner hole 122 may be a threaded engagement, wherein the threads extend along the fastening element engagement portion 152.

[0096] The fastening element head 154 has a fastening element abutment surface 156. The fastening element abutment surface 156 may taper toward the fastening element engagement portion 152. In such a case, the fastening element abutment surface 156 has a conical shape corresponding to the conical shape of the first inner hole abutment sub-surface 66a or the second inner hole abutment sub-surface 66b. Alternatively, in other embodiments, the fastening element abutment surface 156 may be stepped (not shown) to correspond to the stepped first inner hole abutment sub-surface or the second inner hole abutment sub-surface (not shown). The fastening element 150 may be, for example, a conical head screw.

[0097] The fastening element abutment surface 156 abuts against the first inner bore abutment subsurface 66a. In some embodiments, the fastening element abutment surface 156 may abut against either the first inner bore abutment subsurface 66a or the second inner bore abutment subsurface 66b. Alternatively, the second inner bore abutment subsurface 66b may accommodate fastening elements of different shapes.

[0098] For the sake of clarity, the sealing produced by fastening element 150 and the first blade endoporus 60 hinders or prevents the fluid connection (that is, leakage) between the side surface of the first blade endoporus 60 and the cutting tool 1. In detail, this seal is between one of the fastening element abutting surface 156 and the first endoporus abutting sub-surface 66a and the second endoporus abutting sub-surface 66b. In addition, this seal allows the continuous fluid connection between the retainer inlet 134 and the first blade outlet 82a and the second blade outlet 82b. The sealing produced by fastening element 150 and the first blade endoporus 60 is not necessarily airtight, and may have some leakages.

[0099] The fastening element 150 of the present invention is preferably but optionally a commercially available clamping screw that is shaped and sized to fit within the first retainer inner bore 122 .

[0100] like Figure 5 As best seen in , when the fastening element 150 clamps the cutting insert 20 against the insert holder 100, a space is created for coolant to pass from the insert holder 100 to the cutting insert 20. More specifically, the space can be defined between a fastening element abutment surface 156 abutting one of the first inner bore abutment sub-surface 66a and the second inner bore abutment sub-surface 66b, the other of the first inner bore abutment sub-surface 66a and the second inner bore abutment sub-surface 66b, the holder fastening surface 120, and the access gap 68.

[0101] In some embodiments, in addition to abutting the first inner hole abutment sub-surface 66a, the fastening element abutment surface 156 may also abut the first entry abutment sub-surface 70a. When the cutting insert 20 is reversed in the insert holder 100, in addition to abutting the second inner hole abutment sub-surface 66b, the fastening element abutment surface 156 may also abut the second entry abutment sub-surface 70b. For the sake of clarity, reversing the cutting insert 20 refers to disassembling the cutting tool 1 by first disengaging the at least one fastening element 150 from the cutting insert 20 and the insert holder 100, flipping the cutting insert 20, thereby switching the positions of the first insert side surface 22 and the second insert side surface 24 and abutting the retainer fastening surface 120 with the surface that was not previously abutted. Then, the cutting insert 20 is fastened to the insert holder 100.

[0102] Although the subject matter of the present application has been described with a certain degree of particularity, it will be understood that various changes and modifications can be made without departing from the spirit or scope of the invention as hereinafter claimed.

Claims

1. A cutting insert (20) having a blade width W and comprising: Opposing first blade side surface (22) and second blade side surface (24); a peripheral blade surface (30) connecting the first blade side surface (22) and the second blade side surface (24); a first insert seat (50), the first insert seat (50) being located at the intersection of the first blade side surface (22), the second blade side surface (24) and the peripheral blade surface (30); A first blade inner hole (60), the first blade inner hole (60) is open to the first blade side surface (22) and the second blade side surface (24); a first blade inlet (80a); as well as a first blade outlet (82a) opening outwardly toward the first insert seat (50) and fluidly connected to the first blade inlet (80a); The first blade inner hole (60) has a first blade inner hole axis (B), the first blade inner hole axis (B) defines a radially outward direction (Ro) extending radially outward from the first blade inner hole axis and a radially inward direction (Ri) opposite to the radially outward direction (Ro); The first blade inner hole (60) comprises: a first inner hole edge (62a), the first inner hole edge (62a) being formed at the intersection of the first blade side surface (22) and the first blade inner hole (60); a second inner hole edge (62b) formed at the intersection of the second blade side surface (24) and the first blade inner hole (60); and a first inner hole peripheral surface (64), the first inner hole peripheral surface (64) connecting the first inner hole edge (62a) and the second inner hole edge (62b) and including a first inner hole abutment sub-surface (66a); in: The first inner bore peripheral surface (64) further includes an entry gap (68) that is recessed further from the first insert inner bore axis (B) than the first inner bore abutment subsurface (66a); and The entry gap (68) is in fluid connection with the first blade inlet (80a).

2. The cutting insert (20) according to claim 1, wherein: The blade width W satisfies the following condition: 1.4 mm ≤ W ≤ 3.6 mm.

3. The cutting insert (20) according to any one of the preceding claims, wherein: The first bore abutment sub-surface (66a) tapers conically inwardly from the first insert side surface (22) toward the first insert bore axis (B).

4. The cutting insert (20) according to any one of the preceding claims, wherein: The first inner bore abutment sub-surface (66a) includes a first entry abutment sub-surface (70a) located between the entry gap (68) and the first inner bore edge (62a).

5. The cutting insert (20) according to claim 4, wherein: The first bore abutment sub-surface (66a) and the first entry abutment sub-surface (70a) taper conically inwardly from the first insert side surface (22) toward the first insert bore axis (B).

6. The cutting insert (20) according to any one of the preceding claims, wherein: an imaginary bisecting plane (P) passing midway between the first blade side surface (22) and the second blade side surface (24); The first inner hole abutment subsurface (66a) is located between the imaginary bisector plane (P) and the first inner hole edge (62a); The first inner hole peripheral surface (64) further includes a second inner hole abutment subsurface (66b) located between the imaginary bisector plane (P) and the second inner hole edge (62b); and The entry gap (68) opens outwardly to the first inner bore abutment subsurface (66a) and the second inner bore abutment subsurface (66b).

7. The cutting insert (20) according to claim 6, wherein: The first inner bore abutment sub-surface (66a) tapers conically inwardly from the first insert side surface (22) toward the first insert inner bore axis (B) to the imaginary bisector plane (P); and The second bore abutment sub-surface (66b) tapers conically inwardly from the second insert side surface (24) toward the first insert bore axis (B) to the imaginary bisector plane (P).

8. The cutting insert (20) according to claim 7, wherein: The first inner hole abutment sub-surface (66a) and the second inner hole abutment sub-surface (66b) taper conically with respect to the first insert inner hole axis B at a taper angle α, and the taper angle α satisfies the following condition: 40°≤α≤140°.

9. The cutting insert (20) according to claim 8, wherein: The cone angle α satisfies the following condition: 50°≤α≤90°.

10. The cutting insert (20) according to claim 9, wherein: The cone angle α satisfies the following condition: 55°≤α≤70°.

11. The cutting insert (20) according to claim 6, wherein: The first inner hole abutment subsurface (66a) includes a first entry abutment subsurface (70a) located between the entry gap (68) and the first inner hole edge (62a); and The second inner bore abutment subsurface (66b) includes a second entry abutment subsurface (70b) located between the entry gap (68) and the second inner bore edge (62b).

12. The cutting insert (20) according to claim 11, wherein: The first bore abutment subsurface (66a) and the first entry abutment subsurface (70a) taper conically inwardly from the first insert side surface (22) toward the first insert bore axis (B); and The second bore abutment subsurface (66b) and the second entry abutment subsurface (70b) taper conically inwardly from the second insert side surface (24) toward the first insert bore axis (B).

13. A cutting tool (1), comprising: A blade holder (100); A fastening element (150); The cutting insert (20) according to claim 1, the cutting insert (20) being releasably fixed to the insert holder (100); and a cutting insert (10) releasably secured to the cutting blade (20); The blade holder (100) comprises: a retainer fastening surface (120), the retainer fastening surface (120) being perpendicular to a retainer fastening surface longitudinal plane (M), the retainer fastening surface longitudinal plane (M) containing the retainer fastening surface longitudinal axis (A); a first retainer inner bore (122) opening outwardly to the retainer fastening surface (120); and a retainer outlet (132) opening outwardly to the retainer fastening surface (120) and being fluidly connected to a retainer inlet (134); The fastening element (150) comprises: a fastening element engaging portion (152); and a fastening element head (154), the fastening element head (154) comprising a fastening element abutment surface (156); The second blade side surface (24) abuts the retainer securing surface (120); and The fastening element (150) clamps the cutting insert (20) to the insert holder (100) via the first insert bore (60) and the first holder bore (122), and seals the first insert bore (60) at the first bore edge (62a).

14. The cutting tool (1) according to claim 13, wherein: The first inner hole abutment subsurface (66a) includes a first entry abutment subsurface (70a) located between the entry gap (68) and the first inner hole edge (62a); and The fastening element abutment surface (156) abuts against the first entry abutment sub-surface (70a).

15. The cutting tool (1) according to any one of claims 13 and 14, wherein: The fastening element (150) is flush with the first blade side surface (22) or recessed relative to the first blade side surface (22).

16. The cutting tool (1) according to any one of claims 13 to 15, wherein: The retainer fastening surface (120) is mirror-symmetrical with respect to an imaginary retainer fastening surface longitudinal plane (M).

17. The cutting tool (1) according to any one of claims 13 to 16, wherein: The first retainer inner bore (122) and the retainer outlet (132) are spaced apart from each other and are fluidly connected via a retainer groove (136) recessed on the retainer fastening surface (120).

18. The cutting tool (1) according to claim 17, wherein: The retainer outlet (132) is positioned closer to a center (C) of the retainer fastening surface (120) than the first retainer inner bore (122).

19. The cutting tool (1) according to any one of claims 13 to 18, wherein: an imaginary bisecting plane (P) passing midway between the first blade side surface (22) and the second blade side surface (24); The first inner hole abutment subsurface (66a) is located between the imaginary bisector plane (P) and the first inner hole edge (62a); The first inner hole peripheral surface (64) further includes a second inner hole abutting sub-surface (66b) located between the imaginary bisector plane (P) and the second inner hole edge (62b); The entry gap (68) opens outwardly to the first inner hole abutment subsurface (66a) and the second inner hole abutment subsurface (66b); and The cutting insert (20) is fixed to the insert holder (100) in any of the following situations: The second insert side surface (24) abuts the retainer fastening surface (120), and the fastening element (150) engages the first retainer bore (122), clamps the first bore abutment subsurface (66a), and seals the first insert bore (60) at the first bore edge (62a); or The first blade side surface (22) abuts the retainer fastening surface (120), and the fastening element (150) engages the first retainer bore (122), clamps the second bore abutment subsurface (66b) and seals the first blade bore (60) at the second bore edge (62b).

20. The cutting tool (1) according to claim 19, wherein: At the entry gap (68), the first inner hole abutment sub-surface (66a) and the second inner hole abutment sub-surface (66b) include a first entry abutment sub-surface (70a) and a second entry abutment sub-surface (70b), respectively; and The fastening element abutment surface (156) abuts against one of the first entry abutment sub-surface (70a) and the second entry abutment sub-surface (70b).

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