cutting tools

Abstract

To improve performance in ejecting cut chips to improve production efficiency.SOLUTION: A cutting tool has an upper surface, a flank face, and a cutting blade 31 formed at a ridge line between the upper surface and the flank face and is formed in a shape extending in a longitudinal direction along a longitudinal reference shaft 20x, from a basic end part 20b toward a tip part 20t, where the cutting blade 31 is arranged at the tip part 20t. The cutting tool is provided with a chip discharging groove 25 which is constituted of a wall surface 26 at least a portion of which is curved and at least a portion of which is positioned higher than the cutting blade 31 and is formed in a shape extending in a direction different from an axial direction of the longitudinal reference shaft 20x.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a cutting tool. [Background technology]

[0002] Various cutting tools for cut-off or grooving have been proposed in the past (see, for example, Patent Documents 1, 2, and 4). Furthermore, cutting inserts have been proposed as turning tools, in which an ultra-high pressure sintered body such as PCD (sintered diamond) is used as the cutting edge and the ultra-high pressure sintered body is attached by brazing or the like to a base tip made of a carbide substrate, and which are configured to be suitable for grooving aluminum materials (see, for example, Patent Document 3).

[0003] Various methods have been proposed to improve chip control when using cutting inserts such as the latter, including the use of cutting inserts with chip breakers made of ultra-high pressure sintered compacts. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 8-300202 [Patent Document 2] Patent No. 6976522 [Patent Document 3] Japanese Patent Application Laid-Open No. 2017-196693 [Patent Document 4] International Publication WO2015 / 098917 Summary of the Invention [Problem to be solved by the invention]

[0005] However, with conventional cutting inserts like those mentioned above, for example, when machining grooves in a workpiece near the chuck, chips can hit the chuck and become tangled in the chuck or its surrounding area. In such cases, attempting to remove the tangled chips can reduce production efficiency. One way to stabilize chip control is to reduce the feed rate, but this increases the processing time, which also reduces production efficiency.

[0006] In addition, in a typical NC lathe, the workpiece chuck is located on the left side in a plan view, and the free end (or tailstock) is located on the right side, leaving a large space for chip evacuation. In such cases, it is desirable to guide the chips to the opposite side of the chuck.

[0007] SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a cutting tool that improves chip discharge properties and enables increased production efficiency. [Means for solving the problem]

[0008] One aspect of the present invention is a cutting tool having an upper surface, a flank, and a cutting edge formed on a ridge line between the upper surface and the flank, the cutting tool having a shape extending in a longitudinal direction along a longitudinal reference axis from a base end to a tip end, the cutting edge being at the tip end, This cutting tool is made up of a wall surface at least part of which is curved and at least part of which is located higher than the cutting edge, and is provided with a chip discharge groove shaped to extend in a direction different from the axial direction of the longitudinal reference axis.

[0009] According to the cutting tool of the above aspect, the chip groove, which includes a wall surface located higher than the cutting edge, can reliably guide and discharge chips in a direction different from the axial direction of the longitudinal reference axis so that the chips do not become entangled in the workpiece, etc. Such a cutting tool can improve production efficiency.

[0010] In the cutting tool as described above, when viewed from above in a plane perpendicular to the longitudinal reference axis, an imaginary center line passing through the center of the chip discharge groove may be inclined with respect to the longitudinal reference axis.

[0011] In the cutting tool as described above, when viewed from the top in a plane perpendicular to the longitudinal reference axis, the intersection of an imaginary center line passing through the center of the chip discharge groove and the longitudinal reference axis may be located closer to the base end than the cutting edge.

[0012] In the cutting tool as described above, the chip discharge flutes may be asymmetrical about the longitudinal reference axis in a plan view perpendicular to the longitudinal reference axis as seen from above.

[0013] In the cutting tool described above, the chip discharge groove may be formed across the center of the cutting tool in the width direction when viewed from the top in a plan view perpendicular to the longitudinal reference axis.

[0014] In the cutting tool as described above, the wall surfaces that form the chip discharge grooves may be composed of curved surfaces only.

[0015] In the cutting tool as described above, at least a part of the wall surface forming the chip groove may be formed as a cylindrical surface.

[0016] In the cutting tool as described above, the wall surface forming the chip discharge groove may be configured as a cylindrical surface.

[0017] Another embodiment of the cutting tool of the present invention is a cutting tool having a cutting edge member having a first end face, a second end face opposite the first end face, a flank face, and a cutting edge formed on the ridge line between the first end face and the flank face, and a base member having a shape extending longitudinally from the base end to the tip end along a longitudinal reference axis, and to which the cutting edge member is joined at the tip end, wherein the base member has a wall surface at least partially curved and at least partially located higher than the first end face, and is provided with a chip discharge groove having a shape extending in a direction different from the axial direction of the longitudinal reference axis of the base member.

[0018] According to the cutting tool of the above aspect, the chip discharge groove, which includes a wall surface located higher than the upper surface of the cutting edge member, can reliably discharge chips in a direction different from the axial direction of the longitudinal reference axis of the base member so that the chips do not become entangled in the workpiece. Such a cutting tool achieves stable chip disposal even during high-feed machining. This improves the degree of freedom in feed during cutting, thereby improving production efficiency.

[0019] In the cutting tool as described above, the starting end of the chip discharge groove may be located at the base end side portion of the cutting edge member.

[0020] In the cutting tool described above, the chip discharge grooves may be asymmetrical about the longitudinal reference axis of the base member in a plan view perpendicular to the longitudinal reference axis as seen from the first end face.

[0021] In the cutting tool described above, the chip discharge groove may be formed across the center of the width direction of the base member in a plan view perpendicular to the longitudinal reference axis as seen from the first end face.

[0022] In the cutting tool as described above, when viewed from the first end face in a plane perpendicular to the longitudinal reference axis, the intersection of an imaginary center line passing through the center of the chip discharge groove and the longitudinal reference may be located closer to the tip end than to the base end portion of the cutting edge member.

[0023] In the cutting tool as described above, the cutting edge member may be joined to the base member inclined so that the base end side is downward relative to the tip side.

[0024] In the cutting tool as described above, the cutting edge member may be an ultra-high pressure sintered body. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a perspective view showing a cutting tool according to a first embodiment of the present invention. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] FIG. 2 is a perspective view showing an example of the configuration of a cutting edge member and a base tip. [Figure 5] 3A and 3B are plan views showing examples of the configuration of a cutting edge member and a base tip. [Figure 6] FIG. 10 is a side view showing a state in which (A) the cutting edge member is joined to a base tip with the base end inclined downward relative to the end side, and (B) the cutting edge member is joined to a base tip without being inclined. [Figure 7] FIG. 4 is a perspective view of a cutting tool according to a second embodiment of the present invention. [Figure 8] FIG. [Figure 9] FIG. [Figure 10] 1A is an image of chips generated by cutting using a cutting tool according to the present invention, and FIG. 1B is an image of chips generated by cutting using a conventional cutting tool. DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, preferred embodiments of the cutting tool according to the present invention will be described in detail with reference to the drawings (see FIG. 1, etc.).

[0027] [[First embodiment]] The cutting tool 1 according to this embodiment comprises a cutting insert 10 and a tool holder 50 for holding the cutting insert 10 (see FIGS. 1 to 3). The cutting insert 10 is particularly suitable for groove machining of aluminum materials and is formed by joining, for example by brazing, a cutting edge body 30 made of an ultra-high-pressure sintered compact, which is harder than the base tip 20, to a base tip 20 made of a superalloy. A suitable example of an ultra-high-pressure sintered compact is PCD (sintered diamond). The cutting insert 10 thus configured has excellent wear resistance and can be used to cut various metallic materials, including cast iron, high-hardness metallic materials, and non-ferrous alloys such as aluminum. The cutting insert 10 is attached to the tool holder 50 and is fed in the groove direction during groove machining to cut a workpiece (workpiece) 100 (see FIG. 2). In this embodiment, an axis located approximately at the center of the base tip 20 extending from the base end 20b to the tip end 20t along the grooving direction is referred to as the longitudinal reference axis and is indicated by the symbol 20x (see FIG. 5). Alternatively, in a plan view (when viewed from the upper surface 30u of the cutting body 30 described later), an axis extending along the longitudinal direction of a substrate 20' corresponding to the base tip, which will be described later, an axis extending along the longitudinal direction of the cutting insert 10, or an axis extending along the longitudinal direction of the cutting tool 1 itself may be used as the longitudinal reference axis.

[0028] [Cutting edge] The cutting body 30 is made of an ultra-high-pressure sintered body formed in a columnar shape having a longitudinal direction x extending in the grooving direction, a width direction y perpendicular to the longitudinal direction x and extending along the leading cutting edge 31, and an up-down direction z perpendicular to both the longitudinal direction x and the width direction y (see FIGS. 4 and 5). The upper surface (first end surface) 30u of the cutting body 30 and the lower surface (second end surface) 30d, which serves as the attachment surface to the base chip 20, are formed in a substantially trapezoidal shape (see FIG. 5, etc.). A peripheral side surface 30s is formed between the upper surface 30u and the lower surface 30d (see FIG. 4, etc.). The cutting body 30 is formed with a cutting edge (leading cutting edge 31), a recessed portion 33, etc. (see FIG. 4, etc.). The recessed portion 33 may be formed in multiple locations. Note that when considering traverse cutting by feeding the cutting tool 1 in the traverse direction, one or both side cutting edges 32 may be formed on the cutting body 30.

[0029] The cutting edge has a leading cutting edge 31 formed on the ridgeline between the peripheral side surface 30s and the top surface 30u of the cutting body 30. When a side cutting edge 32 is formed as described above, the side cutting edge 32 is also included in the cutting edge. The leading cutting edge 31 is formed on the ridgeline between the top surface 30u and a front surface 30f (the front surface 30f is part of the peripheral side surface 30s), which is the surface on the tip side in the longitudinal direction x and serves as a clearance surface, and is used when grooving the workpiece 100. In this embodiment, the leading cutting edge 31 is formed perpendicular to the longitudinal direction x of the cutting body 30. Although not particularly shown, a recess including a rake face may be provided near the leading cutting edge 31. In the cutting tool 1 of this embodiment, the portion between the leading cutting edge 31 and the wall surface of the chip breaker (in this embodiment, the recessed portion 33 described later or its wall surface) functions as the rake face.

[0030] The recessed portion 33 is formed on the upper surface 30u at a position that is the rear of the leading cutting edge 31 in the longitudinal direction x (see FIGS. 4 and 5). The recessed portion 33 in the cutting edge member 30 of this embodiment is configured to function as a chip breaker that breaks the chip 101.

[0031] [Base chip] The base tip 20 is a member for holding the cutting body 30 joined by brazing or the like, and is made of cemented carbide or the like. The base tip 20 is attached to the tool holder 50 by fastening with a screw 22 or the like, with the front surface 30f of the cutting body 30 facing the tip side in the longitudinal direction of the tool holder 50 (see FIGS. 1 to 3).

[0032] The base tip 20 is provided with a chip discharge groove 25 shaped to reliably discharge chips 101 generated during cutting in a direction that prevents them from becoming entangled in the workpiece 100, and in some cases to curl the chips 101 appropriately (see FIGS. 4 and 5). The chip discharge groove 25 is at least partially curved, and at least a portion of the chip discharge groove 25 is formed by a wall surface 26 that is located higher in the vertical direction z than the upper surface 30u of the cutting edge member 30. An example of the size of the curved portion is a radius of curvature R of about 1 mm, but of course this is merely a suitable example.

[0033] The chip discharge groove 25 of this embodiment has a shape in which its starting end 25s is located at the base end portion 30b of the cutting edge member 30. The base end portion of the cutting edge member 30 here refers to the portion of the cutting edge member 30 that has a surface (back surface) opposite the front surface 30f. The chip discharge groove 25 having such a shape extending from the base end portion 30b makes it easy to introduce chips 101 generated by the leading cutting edge 31 into the chip discharge groove 25.

[0034] Furthermore, when the cutting insert 10 is viewed from the upper surface 30u perpendicular to the longitudinal reference axis 20x (referred to as a "plan view" in this specification, and a drawing viewed from this plan view is referred to as a "plan view"), the chip discharge groove 25 of this embodiment has an asymmetrical shape with respect to the longitudinal reference axis 20x as the center. Furthermore, in this plan view, the chip discharge groove 25 is formed to have a size and shape that straddles the center 20m in the width direction y of the base chip 20 (see FIG. 5). Note that the longitudinal reference axis 20x shown in FIG. 5 passes through the center of the base chip 20 in the width direction y, and therefore coincides with the center 20m in the plan view (see FIG. 5).

[0035] The chip discharge grooves 25 are shaped to extend in a direction different from the axial direction of the longitudinal reference axis 20x of the base tip 20 (see FIG. 5). As an example, the chip discharge grooves 25 of this embodiment are formed to extend in a direction tilted clockwise, for example, by about 30°, with respect to the longitudinal reference axis 20x in a plan view (see FIGS. 4 and 5). In other words, if a virtual center line 25x is imagined for the chip discharge groove 25 extending in a direction different from the axial direction of the longitudinal reference axis 20x, the center line 25x is tilted with respect to the longitudinal reference axis 20x in a plan view (see FIG. 5). The central axis 25x of the discharge groove 25 here coincides with an axis passing through the center of the shape if the chip discharge groove 25 is cylindrical or conical, or it can be considered to be an axis curved along the virtual center if the chip discharge groove 25 is curved. A suitable example of the degree of inclination of the chip groove 25 in plan view can be explained using, for example, the position of the intersection P between the longitudinal reference axis 20x and the central axis 25x as a parameter. That is, in plan view, the intersection P should be located a distance x1 away from the leading cutting edge 31 of the cutting member 30 toward the base end 20b, and a distance x2 away from the base end portion 30b of the cutting member 30 toward the tip end 20t (see FIG. 5). When the intersection P is located within this range, the chip groove 25 can be said to be inclined to an extent that it can reliably discharge the chips 100 in a direction that will prevent them from becoming entangled in the workpiece 100 (see FIG. 4, etc.).

[0036] [Tool holder] The tool holder 50 is a tool body that holds the cutting insert 10 at its tip, and is provided so that it can be fed in the groove cutting direction by, for example, a lathe (not shown) (see FIG. 1, etc.).

[0037] [How to use] The cutting insert 10 of this embodiment configured as described above is attached to the tool holder 50 and pressed against a rotating workpiece (material to be cut) 100 to cut the workpiece 100. In practice, the cutting insert 10 is first fed in the grooving direction along the longitudinal direction x of the base tip 20 to perform groove machining (see FIG. 2). In addition to such groove machining, the cutting insert 10 of this embodiment can also perform cut-off machining and turning (lathe machining) using the side cutting edge 32.

[0038] [Chip disposal] According to the cutting insert 10 of this embodiment in which the chip discharge groove 25 as described above is formed in the base tip 20, when the workpiece 100 bites into the leading cutting edge 31, the chips 101 are controlled by the recessed portion 33 of the cutting edge member 30 and guided to the wall surface 26 of the chip discharge groove 25 of the base tip 20. The chips 101 curled by the recessed portion 33 are then guided to this wall surface 26, where they change their flow direction and are discharged. In a typical NC lathe, the chuck for the workpiece 100 is located on the left side in a plan view, and the right side is the free end (or tail stock), so there is a large space for discharging the chips 101. In this regard, the cutting insert 10 exemplified in this embodiment has a structure in which the chip groove 25 and its wall surface 26 are inclined clockwise from the longitudinal reference axis 20x in a plan view, and the chips 101 are discharged to the right, thereby preventing the chips 101 from getting tangled in the workpiece 100 or the machine tool (see FIG. 5, etc.). Needless to say, this is only one example of a suitable structure, and the orientation of the wall surface 26 is not limited to the right, and the orientation and angle of the wall surface 26 can be changed as appropriate depending on the application and structure.

[0039] The cutting insert 10 of this embodiment having such a structure or a cutting tool 1 including the same is particularly suitable for grooving, and when machining the outer diameter of the workpiece 100, the chip evacuation groove 25, including the wall surface 26 located higher than the upper surface 30u of the cutting edge member 30, guides and discharges the chips 101 in a direction different from the axial direction of the longitudinal reference axis of the base tip 20 so that the chips 101 do not get tangled in the workpiece 100. Furthermore, particularly during high-feed machining, the chips may go over the chip breaker, making the chip outflow direction unstable and causing the chips to get tangled in the workpiece or machine tool. This can cause a problem of reduced production efficiency if the tangled chips are removed. However, the cutting insert 10 or cutting tool 1 of this embodiment achieves stable chip disposal even during high-feed machining, improving the degree of freedom in feed during cutting and thereby contributing to improved production efficiency. The cutting insert 10 or cutting tool 1 that is expected to have such an effect is expected to result in improved quality of the machined surface, which is particularly noticeable when cutting a workpiece 100 made of a highly ductile aluminum material.

[0040] Furthermore, in cutting inserts in which an ultra-high pressure sintered body is used as the cutting edge body, it can be said that, due to the technology in which the chip breaker is formed by removing the upper surface of the ultra-high pressure sintered body, it was not possible to provide the chip breaker at a position higher than the upper surface. However, in accordance with the cutting insert 10 of this embodiment or the cutting tool 1 equipped with it, as described above, the chip discharge groove 25 including the wall surface 26 located at a position higher than the upper surface 30u of the cutting edge member 30 guides the chip 101 in a direction different from the axial direction of the longitudinal reference axis, preventing it from becoming entangled in the workpiece 100.

[0041] [[Second embodiment]] The cutting tool 1 according to this embodiment is composed of a cutting insert 10 and a tool holder 50 that holds the cutting insert 10 (see FIGS. 7 to 9). The cutting insert 10 has a leading cutting edge 31 integrally formed on a tip portion 20t of a superalloy substrate 20', which has a structure in which a cutting portion and a holding portion are integrally formed. A side cutting edge 32 may be formed on one or both sides of the leading cutting edge 31 formed on the tip portion 20t.

[0042] In this way, when a cutting insert 10 is used in which the base end 20b of the base body 20' to the leading cutting edge 31 of the tip end 20t are made integrally from a single material (in this embodiment, a superalloy), it is possible to form a cutting insert 10 equipped with a cutting edge simply by undergoing a press molding process, for example, without undergoing a process such as brazing a cutting edge body made of an ultra-high pressure sintered body to a base tip.

[0043] The shape of the tip portion 20t including the leading cutting edge 31 is not particularly limited, but in this embodiment, it has the same shape as the cutting edge member 30 in the first embodiment, and also includes a portion 30b' corresponding to the base end portion 30b and a portion P' corresponding to the intersection P (the intersection between the central axis 20x of the base body 20' and the center line 25A of the chip discharge groove 25) (see Figures 7 to 9).

[0044] The base body 20' is provided with chip discharge grooves 25 (see FIGS. 7 to 9). In this embodiment, the same chip discharge grooves 25 as those in the first embodiment are provided, and as described above, chips 101 generated during cutting are reliably discharged in a direction that prevents them from becoming entangled in the workpiece 100. The chips 101 curled by the recessed portions are then guided to the wall surface 26 of the discharge groove 25, where they change direction and are discharged (see FIGS. 7 to 9).

[0045] According to the cutting tool 1 of this embodiment, the chip discharge groove 25, which includes a wall surface 26 located higher than the leading cutting edge 31, can reliably guide and discharge the chip 101 in a direction different from the axial direction of the longitudinal reference axis 20x so that the chip 101 does not become entangled in the workpiece 100, etc.

[0046] The above-described embodiment is one example of a preferred embodiment of the present invention, but is not limited thereto and various modifications are possible within the scope of the present invention. For example, in the cutting insert 10 shown in the above-described embodiment, the wall surface 26 forming the chip groove 25 is (part of) approximately cylindrical (see FIGS. 4 and 5), but this is merely one example of a preferred embodiment. In other examples, the wall surface 26 forming the chip groove 25 may be composed of only a curved surface, or only a portion of the wall surface 26 forming the chip groove 25 may be composed of only a curved surface. As a specific example of the latter, the wall surface 26 may be a combination of a curved surface and a flat surface.

[0047] Although not specifically mentioned in the above embodiment, the cutting edge member 30 may be joined to the base tip 20 at an incline such that the base end (the portion where the base end portion 30b is located) is inclined downward relative to the tip end (i.e., the side where the front surface 30f is located) (see FIG. 6). In this case, the base end portion 30b of the cutting edge member 30 is positioned deeper (lower), so that the height H2 (e.g., approximately 1 mm) corresponding to the distance between the imaginary extension line of the upper surface 30u of the base end portion 30b and the upper end of the wall surface 26 (indicated by reference symbol 26u in FIG. 6) is relatively larger than the height H1 along the vertical direction z from the cutting edge 31 to the upper end 26u of the wall surface 26 (see FIGS. 6(A) and 6(B)). Furthermore, the cutting edge member 30 is more likely to assume an orientation in which the rake angle of the leading cutting edge 31 is a positive value. When no rake angle is provided (when there is no rake angle), the chips 101 flow almost horizontally along the upper surface 30u (see FIG. 6(B)). In contrast, when the cutting edge member 30 is inclined so that the side where the base end portion 30b is located is downward as described above, the chips 101 can be drawn in deeper, which leads to relatively increasing the height of the wall surface 26u and preventing the chips 101 from climbing over the wall. In this way, the higher the wall, the easier it is to strengthen the force that controls the chips 101, which contributes to further improving the discharge and processability of the chips 101 (see FIG. 6(A)).

[0048] The cutting insert 10 shown in the above embodiment is suitable as an insert for a grooving tool, but strictly speaking, it can improve chip disposal and machined surface quality regardless of the use or shape of the chip, and its use is not particularly limited.

[0049] Furthermore, as a modified example of the cutting insert 10 described above, the depth of the concave portion 33 can be made deeper within the thickness range of the ultra-high pressure sintered body constituting the cutting edge body 30, thereby increasing the rake angle, or a chip breaker can be provided in the concave portion 33.

[0050] In the above-described embodiment, the chip discharge grooves 25 are described as extending along the central axis 25x (see FIG. 5), with the central axis 25x being linear. However, this is merely one suitable example. Although not specifically shown, the chip discharge grooves 25 may be shaped to extend along a curved (virtual) central axis 25x, or may be shaped to extend while twisting in a screw-like manner along the linear or curved central axis 25x.

[0051] Although the cutting insert 10 according to the embodiment of the present invention has been described above, various modifications can be applied thereto. For example, the cutting body 30 of the cutting insert 10 can be made of an ultra-high pressure sintered material such as a diamond sintered material or a cubic boron nitride sintered material, or such a hard material or ultra-high pressure sintered material coated by a CVD method, a PVD method, or the like with a thin film of amorphous carbon or the like selected from the group consisting of carbides, nitrides, oxides, carbonitrides, carbonates, carbonitride oxides, boron nitrides, boron carbonitride oxides, aluminum oxide, and titanium aluminum nitride.

[0052] In the above-described embodiment, the cutting insert 10 is described as being suitable for grooving by feeding in the longitudinal direction x, but this is also merely a preferred example. The present invention is not limited to cut-off or grooving, and can be applied to other turning applications by appropriately changing the shape of the cutting edge. Furthermore, the cutting insert 10 suitable for grooving can also be applied to milling (slot cutter) and the like.

[0053] Furthermore, in the above-described embodiment, a cutting tool 1 including a cutting insert 10 in which a cutting edge body 30 made of an ultra-high-pressure sintered compact, which is harder than the base tip 20, is brazed to a base tip 20 made of a superalloy, has been described, but this is also merely one suitable example. Alternatively, for example, the present invention may be applied to a cutting tool 1 configured such that a sintered compact is directly brazed to a steel cutting tool without using a cutting insert. When the base tip (base member) 20 is made of steel, the cutting edge member 30 may be made of a cemented carbide alloy, but an ultra-high-pressure sintered compact is more preferable. When the cutting edge member 30 is made of a cemented carbide alloy, the cutting edge member may be brazed to a steel shank or the like to form a cutting tool. [Example]

[0054] The state of chips 101 generated when groove cutting was performed using the cutting insert 10 described above was compared with that when a comparative cutting insert without a chip discharge groove was used (see FIG. 10). It was confirmed that the chips 101 generated when groove cutting was performed using the cutting insert 10 of this embodiment did not get tangled around the tool holder 50 but formed a beautiful spiral shape as shown in the figure (see FIG. 10(A)). On the other hand, it was confirmed that the chips 101' generated when a cutting insert without a chip discharge groove was used became tangled around the tool holder and the like, resulting in the state shown in the figure (see FIG. 10(B)). [Industrial Applicability]

[0055] The present invention is suitable for application to cutting tools. [Explanation of symbols]

[0056] 1...Cutting tools 10...Cutting insert (cutting tool) 20...Base chip (base component) 20'...Base 20b...Proximal end 20m: Center of the base chip width in plan view 20t...Tip 20x...Longitudinal reference axis 22...Screw 25...Chip discharge groove 25s…starting end 25x…center line 26...Wall 26u: Top of wall 30...Cutting edge material 30b…Proximal part 30b': A portion corresponding to the base end portion 30b 30f...Front (relief face) 30u...Top surface (first end surface) 30d…Bottom surface (second end surface) 30s…peripheral side 31...Front cutting edge (cutting edge) 32...Side cutting edge 33...Concave part 50...Tool holder 100...Workpiece (material to be cut) 101,101'...Chips P...Intersection point between the central axis 20x of the base tip 20 and the center line 25A of the chip discharge groove 25 P': The part corresponding to the intersection point P x...Longitudinal direction y...Width direction z…Vertical direction

Claims

1. A cutting tool having an upper surface, a flank, and a cutting edge formed on a ridge line between the upper surface and the flank, the cutting tool having a shape extending in a longitudinal direction along a longitudinal reference axis from a base end to a tip end, the cutting edge being at the tip end, A chip discharge groove having a shape extending in a direction different from the axial direction of the longitudinal reference axis in a plan view perpendicular to the longitudinal reference axis as seen from the top surface is provided at a rear stage of the cutting edge, the chip discharge groove having a shape extending in a direction different from the axial direction of the longitudinal reference axis as seen from the top surface, the wall surface being at least partially curved and at least partially located at a position higher than the cutting edge, In the plan view, the chip discharge groove is formed across the center of the cutting tool in the width direction.

2. 2. The cutting tool according to claim 1, wherein, in a plan view perpendicular to the longitudinal reference axis as seen from the top surface, a virtual center line passing through a center of the chip discharge groove is inclined with respect to the longitudinal reference axis.

3. 3. The cutting tool according to claim 2, wherein, in a plan view perpendicular to the longitudinal reference axis as seen from the top surface, an intersection of an imaginary center line passing through a center of the chip groove and the longitudinal reference axis is located closer to the base end than the cutting edge.

4. 2. The cutting tool according to claim 1, wherein the chip discharge flutes are asymmetrical about the longitudinal reference axis in a plan view perpendicular to the longitudinal reference axis as seen from the top surface.

5. 2. The cutting tool according to claim 1, wherein the chip discharge groove is formed in a shape extending in a direction inclined clockwise in a plan view perpendicular to the longitudinal reference axis as seen from the top surface.

6. The cutting tool according to claim 1 , wherein a wall surface forming the chip discharge groove is composed of only a curved surface.

7. The cutting tool according to claim 1 , wherein at least a portion of a wall surface that forms the chip groove is configured as a cylindrical surface.

8. The cutting tool according to claim 1 , wherein a wall surface forming the chip discharge groove is configured as a cylindrical surface.

9. a cutting edge member made of an ultra-high pressure sintered body having a first end surface, a second end surface opposite to the first end surface, a flank surface, and a cutting edge formed on a ridge line between the first end surface and the flank surface; and a base member having a shape extending in a longitudinal direction from a base end to a tip end along a longitudinal reference axis, the base member having the cutting edge member joined to the tip end, the base member is provided with a chip discharge groove having a shape that extends in a direction different from the axial direction of the longitudinal reference axis of the base member when viewed from above in a plan view perpendicular to the longitudinal reference axis, the chip discharge groove including a wall surface at least a portion of which is curved and at least a portion of which is located higher than the first end surface, A cutting tool, wherein a starting end of the chip discharge groove is disposed at a base end portion of the cutting edge member.

10. 10. The cutting tool according to claim 9, wherein the chip discharge grooves are asymmetrical about the longitudinal reference axis of the base member in a plan view perpendicular to the longitudinal reference axis as seen from the first end face.

11. The cutting tool according to claim 10 , wherein the chip discharge groove is formed across a center in a width direction of the base member in a plan view perpendicular to the longitudinal reference axis as seen from the first end face.

12. A cutting tool having a cutting edge member made of an ultra-high pressure sintered body having a first end face, a second end face opposite the first end face, a flank face, and a cutting edge formed on the ridge between the first end face and the flank face, and a base member having a shape extending longitudinally from a base end to a tip end along a longitudinal reference axis, the base member having the cutting edge member joined to the tip end, the base member is provided with a chip discharge groove having a shape that extends in a direction different from the axial direction of the longitudinal reference axis of the base member when viewed from above in a plan view perpendicular to the longitudinal reference axis, the chip discharge groove including a wall surface at least a portion of which is curved and at least a portion of which is located higher than the first end surface, in a plan view perpendicular to the longitudinal reference axis seen from the first end face, an intersection of an imaginary center line passing through a center of the chip discharge groove and the longitudinal reference axis is located closer to the tip end than to the base end portion of the cutting edge member.

13. The cutting tool according to claim 9 , wherein the cutting edge member is joined to the base member at an inclination such that a base end side thereof is downward relative to a tip side thereof.

14. The cutting tool according to claim 9 , wherein the cutting edge member is an ultra-high pressure sintered body.

15. A cutting insert having an upper surface, a flank, and a cutting edge formed on a ridge line between the upper surface and the flank, the cutting insert having a shape extending in a longitudinal direction along a longitudinal reference axis from a base end to a tip end, the cutting edge being at the tip end, and the cutting insert being held in a tool holder for use, A chip discharge groove having a shape extending in a direction different from the axial direction of the longitudinal reference axis in a plan view perpendicular to the longitudinal reference axis as seen from the top surface is provided at a rear stage of the cutting edge, the chip discharge groove having a shape extending in a direction different from the axial direction of the longitudinal reference axis as seen from the top surface, the wall surface being at least partially curved and at least partially located at a position higher than the cutting edge, The cutting insert, wherein the chip discharge groove is formed across the center of the cutting insert in the width direction in the plan view.

Images