Body and cutting tool

Abstract

To provide a body provided with a flow passage having a sufficient cross-sectional area while securing sufficient rigidity, and a cutting tool.SOLUTION: A body 10 of a cutting tool 1 includes: an insert pocket 20 to which a cutting insert 60 is attached; a screw hole 22 into which an insert mounting screw 70 for fastening the cutting insert 60 to the insert pocket 20 is screwed and inserted; and a chip discharging coolant flow passage 50 for discharging coolant C from a discharge port 52 open at a tip. In a cross section orthogonal to an axial direction, at least a portion of the chip discharging coolant flow passage 50 has a distance Da from the insert pocket 20, a distance Db from the screw hole 22, and a distance Dc from an outer periphery 10c of the body 10 which are equal to or larger than a prescribed dimension.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] Patent Document 1 shows a cutting tool for drilling and turning. Patent Document 2 shows a cutting tool having a fluid flow path, and Patent Documents 3 and 4 disclose cutting tools with a flow path opening at the tip. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7290206 [Patent Document 2] International Publication No. 2019 / 069924 [Patent Document 3] Japanese Patent Application Laid-Open No. 2007-185765 [Patent Document 4] Japanese Patent Application Laid-Open No. 2016-128195 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the tip of the cutting tool body has a narrow space due to the presence of fastening parts such as an insert pocket for mounting the cutting insert and a screw hole for fastening the cutting insert, making it difficult to form a flow passage opening at the tip of the body with a sufficient flow passage cross section while suppressing a decrease in rigidity.

[0005] The present invention has been made in view of the above circumstances, and has an object to provide a body and a cutting tool provided with a flow passage having a sufficient cross-sectional area while ensuring sufficient rigidity. [Means for solving the problem]

[0006] A body according to one embodiment of the present invention is a body of a cutting tool, and has an insert mounting seat to which a cutting insert is attached, a fastening portion into which a fastening part that fastens the cutting insert to the insert mounting seat is inserted, and a flow path that discharges a fluid from an outlet that opens at the tip, and in a cross section perpendicular to the axial direction, at least a portion of the flow path is at a distance from the insert mounting seat, a distance from the fastening portion, and a distance from the outer periphery of the body that are all greater than or equal to a predetermined dimension.

[0007] Generally, cutting tools used for drilling holes require a body with a smaller diameter than the hole to be drilled. Furthermore, since it is difficult to supply coolant from an external source to the hole to be drilled and to remove chips from the hole, it is desirable to provide a flow path for spraying coolant from the tip of the body. In a body having an insert seat for mounting a cutting insert and a fastening portion, such as a threaded hole into which a fastening part for fastening the cutting insert to the insert seat is screwed, when providing a flow path for discharging a fluid from an outlet opening at the tip, a portion of the flow path passes through a narrow area surrounded by the insert seat, the fastening portion, and the outer periphery. In this regard, in the body with the above structure, in a cross section perpendicular to the axial direction, the distance from the insert seat, the distance from the fastening portion, and the distance from the outer periphery of the body to at least a portion of the flow path having an outlet at the tip are each set to a predetermined value or greater. This allows for a flow path with a maximum cross-sectional area while minimizing a decrease in rigidity. This improves cooling of the cutting insert and chip evacuation, thereby reducing chip clogging.

[0008] The distance from the insert mounting seat, the distance from the screw hole, and the distance from the outer periphery of the body may be 0.1 mm or more and 0.5 mm or less.

[0009] The distance from the insert mounting seat, the distance from the screw hole, and the distance from the outer periphery of the body may be the same.

[0010] At least a portion of the flow path may be substantially triangular in a cross section perpendicular to the axial direction.

[0011] In a cross section perpendicular to the axial direction, at least a part of the outer periphery of the body may have an arc-shaped portion, and at least a part of the flow path may be substantially fan-shaped having an arc-shaped portion that follows the outer periphery of the body.

[0012] The discharge port may have a shape different from that of at least a part of the flow path in a cross section perpendicular to the axial direction.

[0013] A portion of the flow path that is connected to the discharge port may extend in a direction away from the insert mounting seat while curving along the outer periphery of the fastening portion.

[0014] The insert mounting seat may further have another flow passage that opens on the base end side thereof.

[0015] A cutting tool according to one aspect of the present invention includes the body having the above-described configuration. [Effects of the Invention]

[0016] According to the present invention, a body and a cutting tool are provided that are provided with a flow passage having a sufficient cross-sectional area while ensuring sufficient rigidity. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a perspective view showing a cutting tool according to an embodiment of the present invention. [Figure 2] FIG. [Figure 3] FIG. 2 is a perspective view showing the internal structure of the body in a see-through state. [Figure 4] FIG. 2 is a perspective view showing the internal structure of the tip portion of the body in a see-through state. [Figure 5] FIG. 2 is a cross-sectional view of the tip of the cutting tool, taken perpendicular to the axial direction. [Figure 6] FIG. 2 is a perspective view of the tip of the cutting tool. [Figure 7] FIG. 2 is a diagram illustrating the internal state of a workpiece (workpiece) during drilling. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, preferred embodiments of a body and a cutting tool according to the present invention will be described in detail with reference to the drawings (see FIGS. 1 to 7).

[0019] The cutting tool 1 of this embodiment is formed as a multi-function tool (a composite tool for drilling and turning) capable of performing both drilling and internal and external turning. The body (sometimes called a holder) 10 of the cutting tool 1 is provided with an insert pocket (insert mounting seat) 20, a pocket, and two coolant channels (a coolant channel 40 for cooling the cutting edge and a coolant channel 50 for discharging chips) (see FIG. 3, etc.).

[0020] The insert pocket 20 functions as an insert mounting seat in which the cutting insert 60 is mounted, and is formed at the tip 10t along the central axis 10A of the body 10 (see FIGS. 2 to 4, etc.). A threaded hole (fastening portion) 22 into which the insert mounting screw 70 is threaded is provided in the seat surface 21 of the insert pocket 20 (see FIGS. 2 to 4, etc.). In addition, a recess 24 is provided at the corner of the insert pocket 20 to avoid contact with the intersecting ridge line between the bottom surface and side surface of the cutting insert 60 (see FIGS. 2 to 4, etc.).

[0021] The pocket is a recess formed from the insert pocket 20 toward the base end 10b of the body 10. The pocket in the cutting tool 1 of this embodiment is formed as a chip groove 30 for guiding and discharging chips generated by cutting. Below, as one specific example of the pocket, an embodiment in which the pocket is a chip groove 30 will be described (see FIG. 1, etc.).

[0022] [Chip evacuation coolant passage (passage)] The chip discharge coolant passage 50 is one of two coolant passages provided in the body 10, and is primarily formed as a passage for supplying coolant C to improve chip discharge performance during cutting (see FIG. 3, etc.). The chip discharge coolant passage 50 is connected to a supply passage 10r provided on the base end 10b side of the body 10 (see FIG. 3, etc.). The discharge port 52 is provided at a position suitable for improving chip discharge performance, for example, on the end face 12 on the tip end 10t side of the body 10, near the seating surface 21 (for example, at a position radially outward of the seating surface 21 of the body 10) (see FIGS. 1 to 4, etc.).

[0023] The chip discharge coolant passage 50 forms a tip passage portion 50t at the tip portion 10t of the body 10 (see FIGS. 4, 5, etc.). In this tip passage portion 50t, in a cross section perpendicular to the central axis 10A of the body 10 and passing through at least a portion of the central axis of the screw hole 22, the distance Da from the insert pocket 20, the distance Db from the screw hole 22, and the distance Dc from the outer periphery 10c of the body 10 are each equal to or greater than a predetermined distance (see FIG. 5, etc.). In the tip passage portion 50t of the chip discharge coolant passage 50, the distance Da from the insert pocket 20, the distance Db from the screw hole 22, and the distance Dc from the outer periphery 10c of the body 10 are all the shortest distances. The insert pocket 20 has a relief portion 24a at its corner. Therefore, the distance Da from the insert pocket 20 is the shortest distance from the relief portion 24a of the insert pocket 20. In this example, the distance Da from the insert pocket 20, the distance Db from the threaded hole 22, and the distance Dc from the outer periphery 10c of the body 10 are all equal. These "equal" dimensions do not necessarily mean exactly the same dimensions, but also include slightly different, approximate dimensions. If the distances Da, Db, and Dc are 0.1 mm or greater, the body 10 having the distal flow passage portion 50t can be manufactured without difficulty, and if they are 0.5 mm or less, a suitable flow passage cross-sectional area can be ensured. These distances Da, Db, and Dc are preferably 0.3 mm within the range of 0.1 mm to 0.5 mm. Because different portions of the body 10 experience different forces, such as stress concentration, it is preferable that the distances Da, Db, and Dc be different from one another.

[0024] Generally, in a cutting tool 1 used for drilling holes, the body 10 must be smaller in diameter than the hole to be drilled. Therefore, in the body 10, which has an insert pocket 20 in which a cutting insert 60 is attached and a threaded hole 22 into which an insert mounting screw 70, a fastening part for fastening the cutting insert 60 to the insert pocket 20, is threaded, the area surrounded by the insert pocket 20, the threaded hole 22, and the outer periphery 10c of the body 10 is narrow. Furthermore, in a cutting tool 1 used for drilling holes, it is difficult to supply coolant C from the outside to the hole to be drilled and to discharge chips from the hole. Therefore, it is desirable to spray coolant C from the tip of the body 10. When a chip discharge coolant channel 50 is provided that discharges coolant C from a discharge port 52 opening at the tip of the body 10, a tip channel portion 50t of the chip discharge coolant channel 50 is passed through the narrow area At surrounded by the insert pocket 20, the threaded hole 22, and the outer periphery 10c of the body 10 (see FIG. 5 , etc.). In this regard, in the body 10 of this embodiment, in a cross section perpendicular to the axial direction at the narrow region At, the tip flow passage portion 50t has a distance Da from the insert pocket 20, a distance Db from the threaded hole 22, and a distance Dc from the outer periphery 10c of the body 10 that are equal to or greater than predetermined dimensions. This ensures that the tip flow passage portion 50t of the chip discharge coolant flow passage 50 has a maximum flow passage cross section while suppressing a decrease in the rigidity of the body 10. This makes it possible to improve the cooling of the cutting insert 60 and the discharge of chips by the coolant C discharged from the discharge port 52, and as a result, it becomes possible to suppress chip clogging.

[0025] The tip flow passage portion 50t of this chip discharge coolant passage 50 has a substantially triangular cross-sectional shape (see FIG. 5, etc.). In particular, the tip flow passage portion 50t is formed in an arc shape along the outer periphery 10c of the body 10 on the side of the outer periphery 10c of the body 10. This makes the cross-sectional shape of the tip flow passage portion 50t substantially fan-shaped. By making the cross-sectional shape of the tip flow passage portion 50t substantially triangular and further substantially fan-shaped, a large flow passage cross-section can be ensured in the narrow area At surrounded by the insert pocket 20, the screw hole 22, and the outer periphery 10c of the body 10.

[0026] The tip flow passage portion 50t of the chip discharge coolant flow passage 50 passing through the narrow area At is a curved path 50c that extends further toward the tip of the body 10 than the narrow area At, curving along the outer periphery of the screw hole 22 and extending in a direction away from the seating surface 21 of the insert pocket 20. The cross-sectional shape of the tip flow passage portion 50t is also approximately triangular at the curved path 50c. Note that the cross-sectional shape of the chip discharge coolant flow passage 50 on the base end 10b side of the tip flow passage portion 50t is also approximately triangular.

[0027] The chip discharge coolant passage 50 has a discharge passage 50v that opens at the end face 12 on the tip end 10t side of the body 10, with this opening serving as a discharge port 52 (see FIGS. 3, 4, etc.). The discharge passage 50v extends slightly along the axial direction of the body 10 toward the base end 10b of the body 10. The curved passage 50c connected to the tip passage 50t is connected to one side of the discharge passage 50v at the rear end opposite the discharge port 52. This allows the tip passage 50t to be smoothly connected to the discharge passage 50v, reducing pressure loss in the tip passage 50t.

[0028] The discharge port 52 of the chip discharge coolant passage 50 has a different cross-sectional shape from the tip flow passage portion 50t of the chip discharge coolant passage 50. For example, the discharge port 52 has an elliptical shape that is long in a direction parallel to the seat surface 21 of the insert pocket 20 when viewed from the tip of the body 10 (see FIGS. 4, 6, etc.). The cross-sectional shape of the discharge passage 50v having this discharge port 52 is the same as the shape of the discharge port 52 along its length. In this way, by making the shape of the discharge port 52 different from the cross-sectional shape of the tip flow passage portion 50t of the chip discharge coolant passage 50, it is possible to adjust the discharge direction of the coolant C or increase the discharge speed. For example, by making the discharge port 52 elliptical, it is possible to increase the discharge speed and discharge the coolant C in a balanced manner. Furthermore, in order to ensure both rigidity and coolant supply volume while taking into consideration the clearance between the outer periphery 10c of the body 10 and the insert pocket 20 (i.e., the thickness of that part of the body 10), it may be advantageous to make the discharge port 52 an elliptical shape that is long in the direction parallel to the seat surface 21 of the insert pocket 20.

[0029] The chip discharge coolant flow path 50 is formed so that the cross-sectional area of the discharge port 52 is smaller than the cross-sectional area of the communication portion 50a with the supply path 10r. In this embodiment, the chip discharge coolant flow path 50 has a shape that includes at least a portion where the cross-sectional area of the flow path gradually decreases from the supply port 51 toward the discharge port 52 (see FIGS. 3 and 4, etc.). In this case, the chip discharge coolant flow path 50 does not include a portion where the cross-sectional area suddenly decreases. In this chip discharge coolant flow path 50, which does not include a portion where the cross-sectional area suddenly decreases and where the portion where the cross-sectional area of the flow path decreases gradually, pressure loss when the coolant C flows is relatively small, so the coolant C can be more efficiently supplied to the cutting location and chip clogging can be suppressed in the workpiece (workpiece) 100 (see FIG. 7). Furthermore, the coolant flow path 50 for discharging chips in this embodiment is formed from a single flow path that does not branch off along the way from the communicating portion 50a to the discharge port 52 (see Figure 7), and there is no loss (branching loss) that can occur when there is a branching path, so pressure loss when flowing coolant C is reduced and it can be supplied more efficiently.

[0030] The chip discharge coolant passage 50 may be formed substantially linearly from the communication portion 50a, which communicates with the supply passage 10r, toward the tip 10t. However, the chip discharge coolant passage 50 in the cutting tool 1 of this embodiment gently curves from the communication portion 50a toward the tip 10t of the body 10, and then curves around the threaded hole 22 in the body 22 near the tip 10t to avoid the threaded hole 22, and reaches the discharge port 52 near the cutting edge 61 (see FIGS. 3 and 4, etc.). When avoiding the threaded hole 22, the chip discharge coolant passage 50 may be shaped to extend in a direction away from the relief portion 24 (more specifically, the relief portion 24 that avoids contact with the outer peripheral cutting edge of the cutting insert 60 on the side not used as the cutting edge 61, and is indicated by the reference symbol 24a in FIGS. 2 to 4), thereby improving the rigidity of the surrounding area (see FIGS. 2 to 4, etc.).

[0031] [Cutting edge cooling passage (other passages)] The cutting edge cooling coolant flow path 40 is the other of the two coolant flow paths provided in the body 10, and is formed mainly as a flow path for supplying coolant C for cooling the cutting edge 61 of the cutting insert 60 (see FIGS. 1, 3, etc.). A supply path 10r for supplying coolant C is provided on the base end portion 10b side of the body 10, and the cutting edge cooling coolant flow path 40 branches off from the supply path 10r (see FIG. 3, etc.).

[0032] The discharge port 42 is provided at a position suitable for discharging the coolant C toward the cutting edge 61 of the cutting insert 60, for example, at a position near the insert pocket 20 (more specifically, at a position near the base end 10b side of the insert pocket 20 so that a portion of the discharge port 42 overlaps with the insert pocket 20) (see FIGS. 1, 3, 6, etc.). The shape of the discharge port 42 may be circular, or may be non-circular so as to make it easier to ensure rigidity around the discharge port 42.

[0033] The cutting edge cooling coolant flow passage 40 branching off from the supply passage 10r may be formed in a substantially straight line toward the tip 10t, or may be formed in a non-linear shape that curves midway. The cutting edge cooling coolant flow passage 40 in the cutting tool 1 of this embodiment extends in a substantially straight line from a branching portion 40a extending from the supply passage 10r toward the outer periphery of the body 10 toward the tip 10t of the body 10, and curves radially inward at a curved portion 43 provided immediately before the discharge port 42 (see FIGS. 3 and 4, etc.).

[0034] The cross-sectional area of the cutting edge cooling coolant flow passage 40 is formed to be smaller than the cross-sectional area of the supply passage 10r. While the specific shape from the branch portion 40a to the discharge port 42 is not particularly limited, the cutting edge cooling coolant flow passage 40 in this embodiment preferably has a shape that includes at least a portion where the flow passage cross-sectional area gradually decreases from the branch portion 40a toward the discharge port 42. In this case, the cutting edge cooling coolant flow passage 40 does not include a portion where the cross-sectional area suddenly decreases. In this cutting edge cooling coolant flow passage 40, which does not include a portion where the cross-sectional area suddenly decreases and where the flow passage cross-sectional area decreases gradually, pressure loss when the coolant C flows is relatively small. This allows the coolant C to be more efficiently supplied to the cutting point, and the flow rate of the coolant C can be increased along the way to efficiently cool and lubricate the cutting point, thereby contributing to reducing wear of the cutting insert 60 (see FIGS. 6 and 7, etc.).

[0035] In the body 10 and cutting tool 1 of this embodiment as described above, in the tip passage portion 50t of the chip discharge coolant passage 50 passing through the narrow area At surrounded by the insert pocket 20, the threaded hole 22, and the outer periphery 10c of the body 10, the distance Da from the insert pocket 20, the distance Db from the threaded hole 22, and the distance Dc from the outer periphery 10c of the body 10 are each set to a predetermined value or more. This ensures that the chip discharge coolant passage 50 has a maximum passage cross-section while suppressing a decrease in rigidity at the tip portion of the body 10. This makes it possible to improve the cooling of the cutting insert 60 and the chip discharge performance by the coolant C discharged from the discharge port 52, and as a result, it is possible to suppress chip clogging.

[0036] Furthermore, in the body 10 and cutting tool 1 of this embodiment, the coolant C discharged from the chip discharge coolant flow path 50 toward the end face within the workpiece 100 not only improves the chip discharge performance within the workpiece 100 and suppresses chip clogging, but also improves the cooling performance of the cutting point via the cutting edge cooling coolant flow path 40 (see Figure 7).

[0037] The structure of this embodiment can also be applied to a cutting tool 1 for small diameter machining or its body 10. That is, while it may be impossible to freely design a coolant flow path with conventional tools or the methods for manufacturing them, the cutting tool 1 or its body 10 of this embodiment can be freely designed by using, for example, 3D printing, to realize the flow path shape, position, and aspect that can achieve the above-mentioned features.

[0038] The above-described embodiment is one example of a preferred embodiment of the present invention, but is not limited to this, and various modifications are possible within the scope of the present invention. For example, in the above-described embodiment, the body 10 and cutting tool 1 are described in which the pockets are chip grooves 30 for guiding and discharging chips generated by cutting, but this is merely one preferred example, and the present invention can also be applied to cutting tools 1 and the like that have pockets other than chip grooves 30.

[0039] Furthermore, the cutting tool 1 and its body 10 described in this embodiment are particularly suitable for application to a multi-function tool (a composite tool for drilling and turning) that can perform both drilling and internal and external turning, but it goes without saying that they may also be applied to tools other than multi-function tools. [Industrial Applicability]

[0040] The present invention is suitable for application to a body and a cutting tool. [Explanation of symbols]

[0041] 1 cutting tools 10 Body 10b Base end 20 Insert pocket (insert mounting seat) 22 Screw holes (fastening part) 40 Coolant passage for cutting edge cooling (other passages) 50 Coolant passage for chip evacuation (passage) 52 Discharge port 60 cutting inserts 70 Insert mounting screw (fastening part) C Coolant (fluid) Da Distance from insert pocket Db Distance from screw hole Dc Distance from the outer periphery of the body

Claims

1. A cutting tool body, comprising: an insert mounting seat on which a cutting insert is mounted; a fastening portion into which a fastening component that fastens the cutting insert to the insert mounting seat is inserted; a flow path for discharging a fluid from a discharge port that opens at the tip; and In a cross section perpendicular to the axial direction, at least a part of the flow path is at a distance from the insert mounting seat, a distance from the fastening portion, and a distance from an outer periphery of the body that are each equal to or greater than a predetermined dimension. body.

2. the distance from the insert mounting seat, the distance from the screw hole, and the distance from the outer periphery of the body are 0.1 mm or more and 0.5 mm or less; The body of claim 1 .

3. The distance from the insert mounting seat, the distance from the screw hole, and the distance from the outer periphery of the body are equal in dimension. The body of claim 1 .

4. At least a portion of the flow path in a cross section perpendicular to the axial direction is substantially triangular. The body of claim 1 .

5. In a cross section perpendicular to the axial direction, at least a part of the outer periphery of the body has an arc-shaped portion, and at least a part of the flow path has a substantially fan-shaped portion having an arc-shaped portion along the outer periphery of the body. The body of claim 4.

6. The discharge port has a shape different from that of at least a part of the flow path in a cross section perpendicular to the axial direction. The body of claim 1 .

7. a portion of the flow path connected to the discharge port is curved along an outer periphery of the fastening portion; The body of claim 1 .

8. Further, the insert mounting seat has another flow path that opens at a base end side thereof. The body of claim 1 .

9. A cutting tool comprising a body according to any one of claims 1 to 8.

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