Cutting tool and body of the same

Abstract

To devise a coolant passage to supply a coolant more efficiently and inhibit clogging of chips.SOLUTION: A body 10 of a cutting tool includes: an insert attachment seat 20 provided at a tip 10t of the body and configured to be attached with a cutting insert; a pocket 20 formed from the insert attachment seat 20 to a base end 10b of the body 10; a first coolant passage 40 including a coolant discharge port 42 on the pocket 20 and having a non-linear shape; and a second coolant passage 50 including a coolant discharge port 52 at the tip 10t of the body 10 and having a non-linear shape.SELECTED DRAWING: Figure 6

Description

[Technical field]

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

[0002] Conventionally, in addition to tools for drilling and turning (see, for example, Patent Documents 1, 3, and 4), multi-function tools capable of both drilling and internal and external turning are known (see, for example, Patent Document 3). Such multi-function tools have the advantage of being able to improve productivity because many functions are integrated. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-320213 [Patent Document 2] JP 2018-15861 A [Patent Document 3] Special Publication No. 2012-516244 [Patent Document 4] Patent No. 7104055 Summary of the Invention [Problem to be solved by the invention]

[0004] However, consolidating functions into a tool, while it has the advantages mentioned above, also puts a strain on that single tool. For example, if a multi-function tool is used to perform the machining processes of a drill for hole drilling, a boring bar for internal turning, and an external turning tool for external turning, it will have to perform the cutting processes of three tools, which increases the strain and makes the insert more susceptible to deterioration, and therefore the timing for replacing the cutting insert will be earlier. In particular, when performing hole drilling or internal turning, it is difficult to directly cool the cutting edge of the cutting insert using an external oil supply method, which can easily lead to deterioration.

[0005] In order to address the above-mentioned problems, a cutting tool holder (hereinafter also referred to as the body) has been proposed in which a flow passage is provided inside the holder, a coolant is supplied to the flow passage, and the coolant is discharged from an outlet opening to directly cool the cutting edge (see, for example, Patent Document 4). However, such flow passages inside the body are generally formed linearly by cutting with a drill, which may cause pressure loss.

[0006] In addition, because the body has pockets (such as drainage grooves for discharging chips during cutting) formed from the insert mounting seat to the base end of the body, if a coolant outlet is to be provided near the tip of the body, the flow path must be provided in a part with little back metal (a wedge-shaped thin part formed in the body). Therefore, the size of the flow path is inevitably limited, and a flow path can usually only be provided in a small diameter hole, so the coolant flowing in from the supply port provided at the base end of the body is suddenly throttled, which is likely to cause pressure loss. In addition, if the tool is used to perform small-diameter and long-projection drilling, it tends to be more difficult to machine a coolant flow path in the body.

[0007] In light of these various issues, it was felt that it was essential to make the bodies of current cutting tools more efficient in supplying coolant and to further prevent clogging by cutting chips.

[0008] Therefore, an object of the present invention is to provide a cutting tool and a body thereof that can supply coolant more efficiently by improving the coolant flow path and can suppress clogging by cutting chips. [Means for solving the problem]

[0009] One aspect of the present invention is a cutting tool body, comprising: an insert mounting seat provided at a tip portion of the body, to which a cutting insert is attached; a pocket formed from the insert mounting seat toward a base end of the body; a first coolant flow passage having a non-linear shape and having a coolant outlet on the pocket; a second coolant flow passage having a non-linear shape and having a coolant outlet at a tip end of the body; A body comprising:

[0010] Generally, in a conventional cutting tool body in which the coolant passage is formed linearly by cutting with a drill, a step may be formed in which the cross-sectional area of ​​the coolant passage is suddenly reduced as the drill is used. In such a case, a large pressure loss occurs at the step, making it difficult to efficiently supply the coolant. In this regard, in the cutting tool body of the present invention, the coolant passage is non-linear, preferably has a shape that changes smoothly and gradually reduces the cross-sectional area, thereby suppressing the pressure loss in conventional tools and making it possible to supply the coolant more efficiently. In addition, the coolant supplied from the first and second coolant passages can improve the cooling of the cutting insert and the chip discharge, thereby suppressing chip clogging.

[0011] In the body as described above, at least one of the first coolant passage and the second coolant passage may be shaped so that the cross-sectional area of ​​the discharge port is smaller than the cross-sectional area of ​​the coolant supply port.

[0012] In the body as described above, at least one of the first coolant passage and the second coolant passage may have a shape including a portion whose cross-sectional area gradually decreases from the coolant supply port toward the coolant discharge port.

[0013] In the body as described above, neither the first coolant passage nor the second coolant passage need be formed with a location where the cross-sectional area abruptly decreases.

[0014] In the body as described above, the first coolant passage and the second coolant passage may be formed as passages that do not branch out from the supply port to the discharge port.

[0015] In the body as described above, at least one of the outlet port of the first coolant passage and the outlet port of the second coolant passage may be non-circular.

[0016] In the body as described above, the outlet port of the second coolant passage may be non-circular and elongated in a direction parallel to the seating surface of the insert mounting seat.

[0017] In the body as described above, at least one of the first coolant passage and the second coolant passage may have a curved portion midway along the passage.

[0018] In the body as described above, the discharge port of the first coolant passage may be provided at a position on the insert mounting seat near the base end side of the body.

[0019] In the body as described above, the discharge port of the second coolant passage may be provided in an end face on the tip side of the body.

[0020] In the body as described above, the insert mounting seat may have a threaded hole into which an insert mounting screw for mounting the cutting insert is screwed, and the second coolant flow path may have a curved shape around the threaded hole along its way.

[0021] In the body as described above, the pocket may be a chip discharge groove for guiding and discharging chips produced by cutting.

[0022] Another aspect of the present invention is a cutting tool having a body as described above. [Brief description of the drawings]

[0023] [Figure 1]1 is a perspective view showing a cutting tool according to an embodiment of the present invention; [Diagram 2] 1 is a view (plan view) of a cutting tool viewed from a direction perpendicular to the central axis and along a screw hole of an insert pocket. [Diagram 3] 1 is a side view of a cutting tool viewed from a direction perpendicular to the central axis and perpendicular to a screw hole of an insert pocket. [Figure 4] FIG. 2 is a view of the cutting tool as viewed from the base end side of the body along the central axis. [Diagram 5] FIG. 2 is a perspective view of the cutting tool without a cutting insert attached thereto. [Figure 6] FIG. 2 is a perspective view showing an internal structure of the cutting tool in a see-through state. [Figure 7] FIG. 2 is a view of the cutting tool as viewed from the tip end side of the body along the central axis. [Figure 8] 4 is a perspective view of a portion of the cutting tool in a state in which coolant is discharged from a coolant passage for cooling a cutting edge (a first coolant passage). FIG. [Figure 9] FIG. 2 is a diagram illustrating the internal state of a workpiece (material to be cut) during drilling. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, preferred embodiments of a cutting tool and its body according to the present invention will be described in detail with reference to the drawings (see Figs. 1 to 9).

[0025] The cutting tool 1 of this embodiment is formed as a multi-function tool (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 passages (a coolant passage 40 for cooling the cutting edge and a coolant passage 50 for discharging chips) (see FIG. 1, etc.).

[0026] 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. 1 to 3). A screw hole 22 into which an insert mounting screw 70 is screwed is provided in the seat surface 21 of the insert pocket 20 (see Figs. 2, 5, etc.). In addition, a clearance portion 24 is provided at the corner of the insert pocket 20 to avoid contact with the cutting edge 61 of the cutting insert 60 (see Figs. 3 and 5).

[0027] 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 discharge groove 30 for guiding and discharging chips generated by cutting. In the following, as one specific example of the pocket, an embodiment in which the pocket is a chip discharge groove 30 will be described (see FIG. 1, etc.).

[0028] [Cutting edge cooling coolant passage (first coolant passage)] The cutting edge cooling coolant passage 40 is one of two coolant passages provided in the body 10, and is formed mainly as a passage for supplying coolant C for cooling the cutting edge 61 of the cutting insert 60 (see FIG. 6, etc.). A supply port 41 for supplying coolant C to the cutting edge cooling coolant passage 40 is provided at the base end portion 10b of the body 10 (see FIGS. 4 and 6).

[0029] The outlet 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 such that a part of the outlet 42 overlaps with the insert pocket 20) (see FIGS. 3 and 8). The shape of the outlet 42 may be circular, or may be noncircular so as to make it easier to ensure rigidity around the outlet 42.

[0030] The cutting edge cooling coolant passage 40 may be formed in a substantially straight line from the base end 10b to the tip end 10t, or may be formed in a non-linear shape that curves along the way. The cutting edge cooling coolant passage 40 in the cutting tool 1 of this embodiment extends in a substantially straight line from the supply port 41 toward the tip end 10t of the body 10, and curves toward the radial inside of the body 10 at a curved portion 43 provided immediately before the discharge port 42 (see FIG. 6, etc.).

[0031] The cutting edge cooling coolant flow passage 40 is formed so that the cross-sectional area of ​​the discharge port 42 is smaller than the cross-sectional area of ​​the supply port 41. The specific shape from the supply port 41 to the discharge port 42 is not particularly limited, but the cutting edge cooling coolant flow passage 40 in this embodiment has a shape that includes at least a part where the flow passage cross-sectional area gradually decreases from the supply port 41 to the discharge port 42 (see FIG. 6, etc.). In this case, the cutting edge cooling coolant flow passage 40 does not include a part where the cross-sectional area suddenly decreases. In this way, in the cutting edge cooling coolant flow passage 40 that does not include a part where the cross-sectional area suddenly decreases and the part where the flow passage cross-sectional area decreases gradually, the pressure loss when the coolant C flows is relatively small, so that the coolant C can be more efficiently supplied toward the cutting part, and the flow rate of the coolant C can be increased on the way while efficiently cooling and lubricating the cutting part, thereby contributing to suppressing wear of the cutting insert 60 (see FIG. 8, FIG. 9, etc.). Moreover, the cutting edge cooling coolant flow passage 40 of this embodiment is formed as a single flow passage without branching from the supply port 41 to the discharge port 42 (see FIG. 6), so there is no loss (branch loss) that occurs when there is a branched passage. This type of configuration can also contribute to reducing pressure loss when the coolant C flows and to more efficiently supplying it.

[0032] [Coolant passage for chip evacuation (second coolant passage)] The chip discharge coolant passage 50 is the other of the two coolant passages provided in the body 10, and is formed mainly as a passage for supplying coolant C to improve chip discharge performance during cutting (see FIG. 6, etc.). A supply port 51 for supplying coolant C to the chip discharge coolant passage 50 is provided in the base end portion 10b of the body 10 (see FIGS. 4 and 6). The discharge port 52 is provided at a position suitable for improving chip discharge performance, for example, in the end face 12 on the tip end portion 10t side of the body 10, in the vicinity of the seating surface 21 (for example, at a position radially outward of the seating surface 21 of the body 10) (see FIGS. 5 to 8).

[0033] The shape of the discharge port 52 of the coolant passage 50 for discharging chips is not particularly limited, but in the cutting tool 1 of this embodiment, it is a non-circular shape, such as an ellipse that is long in a direction parallel to the seating surface 21 of the insert pocket 20 (see FIG. 7, etc.). In order to ensure both rigidity and a supply of coolant while taking into consideration the clearance between the outer periphery of the body 10 and the insert pocket 20 (i.e., the thickness of that portion of the body 10), it can be advantageous to make the discharge port 52 long in the direction parallel to the seating surface 21 of the insert pocket 20 in this manner.

[0034] The chip discharge coolant flow passage 50 is formed so that the cross-sectional area of ​​the discharge port 52 is smaller than the cross-sectional area of ​​the supply port 51. The specific shape from the supply port 51 to the discharge port 52 is not particularly limited, but the chip discharge coolant flow passage 50 in this embodiment has a shape that includes at least a part where the flow passage cross-sectional area gradually decreases from the supply port 51 toward the discharge port 52 (see FIG. 6, etc.). In this case, the chip discharge coolant flow passage 50 does not include a part where the cross-sectional area suddenly decreases. In this way, in the chip discharge coolant flow passage 50 that does not include a part where the cross-sectional area suddenly decreases and the part where the flow passage cross-sectional area decreases gradually, the pressure loss when the coolant C flows is relatively small, so that the coolant C can be more efficiently supplied to the cutting part and the clogging of the chips in the workpiece (workpiece) 100 can be suppressed (see FIG. 9). Moreover, in this embodiment, the coolant flow path 50 for discharging cutting chips is formed from a single flow path from the supply port 51 to the discharge port 52 without any branching along the way (see Figure 6), and there is no loss (branching loss) that can occur when there is a branching path, so that pressure loss when flowing coolant C is reduced and it is possible to supply it more efficiently.

[0035] The chip discharge coolant passage 50 may be formed in a substantially straight line from the base end 10b to the tip 10t, but the chip discharge coolant passage 50 in the cutting tool 1 of this embodiment is gently curved from the supply port 41 toward the tip 10t of the body 10, and is curved around the screw hole 22 of the body 22 near the tip 10t to avoid the screw hole 22, and reaches the discharge port 52 near the cutting edge 61 (see FIG. 6). When avoiding the screw 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 symbol 24a in FIG. 6) to improve the rigidity around the portion (see FIG. 6).

[0036] In the cutting tool 1 or its body 10 of this embodiment as described above, the coolant passage 40 for cooling the cutting edge and the coolant passage 50 for discharging chips are made to have a non-linear shape including a portion where the cross-sectional area is gradually reduced with a smooth change, so that the internal oil supply mechanism is improved, thereby making it possible to suppress pressure loss as in conventional tools and more efficiently supply the coolant C. If the coolant C can be supplied more efficiently in this way, it becomes possible to further improve the cooling of the cutting insert 60 and the chip discharge performance.

[0037] Furthermore, in the cutting tool 1 or its body 10 of this embodiment, not only is the cooling performance of the cutting point improved by the coolant passage 40 for cooling the cutting edge, but the coolant C discharged from the coolant passage 50 for chip discharge toward the end face within the workpiece 100 improves the discharge performance of chips within the workpiece 100 and suppresses chip clogging (see Figure 9).

[0038] 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 passage in a conventional tool or a method for manufacturing the same, the cutting tool 1 or its body 10 of this embodiment can realize a flow passage shape, position, and aspect that can achieve the above-mentioned features under a free design by adopting, for example, 3D printing.

[0039] The above-described embodiment is one example of a preferred embodiment of the present invention, but is not limited thereto and can be modified in various ways without departing from 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 pocket is a chip discharge groove 30 for guiding and discharging chips generated by cutting, but this is merely one preferred specific example, and the present invention can be applied to a cutting tool 1 having a pocket other than the chip discharge groove 30.

[0040] Furthermore, the cutting tool 1 and its body 10 described in this embodiment are particularly suitable for use as a multi-function tool (a composite tool for drilling and turning) capable of performing both hole 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]

[0041] The present invention is suitable for application to cutting tools and their bodies. [Explanation of symbols]

[0042] 1...Cutting tools 10. Body 10A…Center axis 10b...Proximal end 10t...Tip 12...End face 20...Insert pocket (insert mounting seat) 21…Seat 22…Screw hole 24...Relief area 30…Chip discharge groove (pocket) 40...cutting edge cooling coolant passage (first coolant passage) 41…Supply inlet 42...Discharge port 43…Curved section 50: Coolant passage for chip evacuation (second coolant passage) 51…Supply inlet 52...Discharge port 53…Curved section 60...Cutting insert 61…Cutting edge 70...Insert mounting screw 100...Workpiece (material to be cut) C…Coolant

Claims

1. A cutting tool body, comprising: an insert mounting seat provided at a tip portion of the body, to which a cutting insert is attached; a pocket formed from the insert mounting seat toward a base end of the body; a first coolant passage having a non-linear shape and having a coolant outlet on the pocket; a second coolant flow passage having a non-linear shape and having a coolant outlet at a tip end of the body; Equipped with a body.

2. The body according to claim 1 , wherein at least one of the first coolant passage and the second coolant passage is shaped such that a cross-sectional area of ​​the discharge port is smaller than a cross-sectional area of ​​a supply port of the coolant.

3. The body according to claim 2 , wherein at least one of the first coolant passage and the second coolant passage has a shape including a portion whose cross-sectional area gradually decreases from the supply port toward the discharge port of the coolant.

4. The body of claim 3 , wherein neither the first coolant passage nor the second coolant passage defines an abrupt decrease in cross-sectional area.

5. The body according to claim 1 , wherein the first coolant passage and the second coolant passage are formed as passages that do not branch from the supply port to the discharge port.

6. The body of claim 1 , wherein at least one of the outlet of the first coolant passage and the outlet of the second coolant passage is non-circular.

7. The body according to claim 6 , wherein the outlet port of the second coolant passage has a non-circular shape that is elongated in a direction parallel to a seat surface of the insert mounting seat.

8. The body according to claim 1 , wherein at least one of the first coolant passage and the second coolant passage has a curved portion midway along the passage.

9. The body according to claim 1 , wherein the outlet port of the first coolant passage is provided at a position of the insert mounting seat near a base end side of the body.

10. The body according to claim 1 , wherein the outlet port of the second coolant passage is provided in an end face on a tip side of the body.

11. 8. A body as described in any one of claims 1 to 7, wherein the insert mounting seat has a threaded hole into which an insert mounting screw for mounting the cutting insert is screwed, and the second coolant flow passage has a curved shape around the threaded hole midway through.

12. The body according to claim 1 , wherein the pocket is a chip groove for guiding and discharging chips generated by cutting.

13. A cutting tool comprising a body according to any one of claims 1 to 7.

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