Body and cutting tools

Abstract

The present invention provides a body and cutting tool that can deliver a sufficient amount of coolant to the tool tip, ensuring smooth chip evacuation and extending tool life. [Solution] The cutting tool body 10 for machining a workpiece with a tip cutting edge 81 positioned on the tip side and an outer peripheral cutting edge 82 positioned on the outer circumference, comprises a first coolant passage 60 provided inside and extending from the base end toward the tip, and a groove-shaped second coolant passage 90 provided on the outer circumference and extending along the central axis 10A.

Description

Technical Field

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

Background Art

[0002] Conventionally, a composite tool having a tip cutting edge and an outer peripheral cutting edge is known. With this composite tool, both drilling by the tip cutting edge and internal and external diameter turning by the outer peripheral cutting edge can be performed.

[0003] As this type of cutting tool, Patent Document 1 discloses a cutting tool having a coolant flow path inside the tool, and discharging coolant to the vicinity of the cutting edge and the tip side of the tool through this coolant flow path, aiming to improve the chip discharge performance and extend the tool life.

[0004] Also, Patent Document 2 discloses a cutting tool having a plurality of groove-shaped coolant flow paths for supplying coolant toward the tip of the tool on the outer periphery of a shank portion that can be attached to a sleeve mounted on a machine tool.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] Incidentally, cutting tools having both a cutting edge at the tip and a cutting edge on the outer circumference also perform drilling operations, and therefore have chip evacuation grooves called flutes that extend from the cutting edge to the rear end of the tool. For this reason, there are limitations to supplying a large amount of coolant to the tool tip by providing a coolant channel with a large channel cross-section inside the tool. Furthermore, when supplying coolant from outside the cutting tool, it is desirable to supply sufficient coolant to the tool tip through the gap between the machined hole and the outer circumference of the cutting tool.

[0007] The present invention has been made in view of the above circumstances, and aims to provide a body and cutting tool that can deliver a sufficient amount of coolant to the tool tip, thereby achieving smooth chip evacuation and extending the tool's lifespan. [Means for solving the problem]

[0008] A body according to one aspect of the present invention is a cutting tool body for machining a workpiece with a tip cutting edge positioned on the tip side and an outer cutting edge positioned on the outer circumference, comprising a first coolant passage provided inside and extending from the base end toward the tip, and a groove-shaped second coolant passage provided on the outer circumference and extending along the central axis.

[0009] In the body structure described above, by supplying coolant to the first coolant passage from the base end, the coolant is smoothly delivered through the first coolant passage to the cutting points on the workpiece by the tip cutting edge and the outer cutting edge. Furthermore, by supplying coolant from outside the body and delivering it into the gap between the outer circumference of the body and the machining hole, the coolant is smoothly delivered through the groove-shaped second coolant passage provided on the outer circumference of the body to the cutting points on the workpiece by the tip cutting edge and the outer cutting edge. Thus, with a cutting tool body like the one of the present invention, a sufficient amount of coolant can be supplied to the cutting area at the tip of the tool by internal supply through the first coolant passage or external supply through the second coolant passage, enabling smooth chip evacuation and a longer tool life. In the case of external supply of coolant from outside the body, the coolant could only be supplied through the narrow gap between the outer circumference of the body and the inner circumference of the machined hole. However, in the cutting tool body of the present invention, since the outer circumference of the body has a groove-shaped second coolant passage, the externally supplied coolant smoothly enters the inside of the machined hole from the second coolant passage, allowing a larger amount of coolant to be delivered to the cutting area.

[0010] The base end is a retaining part that is fitted into a cylindrical sleeve and attached to the sleeve, and the second coolant passage does not necessarily have to be provided in the retaining part.

[0011] The thickness of the thinnest portion between the outer surface and the first coolant flow path may be greater than or equal to a predetermined dimension.

[0012] A cutting tool according to one aspect of the present invention comprises a body having the above configuration, and a cutting insert having a cutting edge at the tip and an outer cutting edge, which is mounted on the body. The second coolant passage may be located at the same circumferential position as the discharge hole formed in the sleeve from which the coolant is discharged.

[0013] In one aspect of the present invention, a cutting tool has a tip cutting edge and an outer cutting edge integrally provided at the tip of the body having the above configuration. The second coolant passage may be located at the same circumferential position as the discharge hole formed in the sleeve from which the coolant is discharged. [Effects of the Invention]

[0014] According to the present invention, a body and cutting tool are provided that can supply a sufficient amount of coolant to the tool tip, thereby achieving smooth chip evacuation and extending the tool's lifespan. [Brief explanation of the drawing]

[0015] [Figure 1] This is a perspective view showing a cutting tool in one embodiment of the present invention. [Figure 2]The figure is a plan view of the cutting tool as seen from a direction perpendicular to the central axis and along one direction of the threaded hole of the insert pocket. [Figure 3] The figure is a side view of the cutting tool as seen from a direction perpendicular to the central axis and perpendicular to the threaded hole of the insert pocket. [Figure 4] The figure is a side view of the cutting tool as seen from another direction perpendicular to the central axis and perpendicular to the threaded hole of the insert pocket. [Figure 5] The figure is a rear view of the cutting tool as seen from another direction perpendicular to the central axis and along the threaded hole of the insert pocket. [Figure 6] The figure is a view of the cutting tool as seen along the central axis from the tip side of the body. [Figure 7] The figure is a perspective view of the body. [Figure 8] The figure is a view of the body as seen along the central axis from the tip side. [Figure 9] The figure is a perspective view showing the internal structure of the body in a transparent state. [Figure 10] The figure is a cross-sectional view taken along the line X-X in FIG. 7. [Figure 11] The figure is a perspective view of the cutting tool mounted on the sleeve. [Figure 12] The figure is a view of the cutting tool mounted on the sleeve as seen from the tip side. [Figure 13] The figure is a perspective view of the cutting tool mounted on the sleeve with a discharge hole. [Figure 14] The figure is a view of the cutting tool mounted on the sleeve with a discharge hole as seen from the tip side.

Best Mode for Carrying Out the Invention

[0016] Hereinafter, preferred embodiments of the body and the cutting tool according to the present invention will be described in detail with reference to the drawings (see FIGS. 1 to 14).

[0017] The cutting tool 1 of this embodiment is formed as a multi-functional tool (composite tool for drilling and turning) capable of performing both drilling and internal / external diameter turning. The body (sometimes called a holder) 10 of the cutting tool 1 is provided with an insert pocket (insert mounting seat) 20, a chip discharge groove 30, a first coolant passage (cutting edge cooling passage 40, chip discharge passage 50) 60, and a second coolant passage 90 (lubrication grooves 91, 92, 93) (see Figures 7, 9, etc.). The body 10 is formed in a substantially cylindrical shape extending from the base end 10b to the tip end 10t along the central axis 10A (see Figure 1, etc.).

[0018] A shank portion (holding portion) 14 is provided on the base end 10b side of the body 10 (see Figures 1, 7, etc.). The shank portion 14 is the part of the body 10 that is mounted on a sleeve 101A (see Figures 11, 12) that can be mounted on a machine tool, or a sleeve 101B with a discharge hole (see Figures 13, 14). This shank portion 14 is substantially cylindrical in shape, and a notch portion 14f is formed in a part of the shank portion 14 that functions as an anti-rotation mechanism for the sleeves 101A, 10B. The notch portion 14f may be a flat surface parallel to the central axis 10A (see Figures 1, 7, etc.). In this embodiment, the outer diameter of the shank portion 14 in the body 10 is smaller than the outer diameter of other parts of the body 10 (for example, the tip portion 10t), making it the smallest part of the body 10. Between the shank portion 14 and the part of the body 10 closer to the tip portion 10t than the shank portion 14, a stepped portion 15 is formed where the outer diameter changes abruptly (see Figures 1, 7, etc.).

[0019] The insert pocket 20 functions as an insert mounting seat to which the cutting insert 80 is attached, and is formed at the tip portion 10t along the central axis 10A of the body 10 (see Figures 7, 8, etc.). The seating surface 21 of the insert pocket 20 is provided with a screw hole (fastening portion) 22 into which the insert mounting screw 70 is screwed.

[0020] The cutting insert 80 is formed in a roughly rectangular shape when viewed from above. The cutting insert 80 has a cutting edge 81 at the front and an outer cutting edge 82 at a pair of corners positioned opposite each other (see Figures 1 and 2, etc.).

[0021] The cutting insert 80 is positioned in the insert pocket 20 with one corner of the body 10 having a cutting edge 81 and an outer cutting edge 82 for cutting on the outer circumference side of the tip, and is fastened and fixed in the screw hole 22 by the insert mounting screw 70. As a result, the body 10 has a cutting edge 81 for drilling on its tip side and an outer cutting edge 82 for turning the inner and outer diameters on its outer circumference side.

[0022] The body 10 is provided with a relief portion 24 at the corner of the insert pocket 20 so as not to come into contact with the intersecting ridge line between the bottom surface and the side surface of the cutting insert 80 (see Figures 1, 7, etc.). The body 10 is also provided with a relief hole 25 so as not to come into contact with the other corner having the tip cutting edge 81 and outer peripheral cutting edge 82 that are not used for cutting when the cutting insert 80 is mounted in the insert pocket 20 (see Figure 4, etc.).

[0023] As described above, in the cutting tool 1 of this embodiment, a cutting insert 80 having a tip cutting edge 81 and an outer cutting edge 82 is mounted in the insert pocket 20. However, this is merely one preferred example. Although not specifically shown in the figures, the cutting tool 1 may have the tip cutting edge 81 and the outer cutting edge 82 integrally provided on the tip portion 10t of the body 10, or a brazed tool may be used in which a cutting insert having a tip cutting edge 81 and an outer cutting edge 82 is brazed to it.

[0024] The chip discharge groove 30 (sometimes called a flute or pocket) consists of a recess formed from the insert pocket 20 toward the base end 10b of the body 10. In the cutting tool 1 of this embodiment, the chip discharge groove 30 is formed as a groove for guiding and discharging chips generated by drilling (see Figures 1, 7, etc.).

[0025] The first coolant passage 60 is located inside the body 10 (see Figure 9). The first coolant passage 60 includes a cutting edge cooling passage 40 and a chip discharge passage 50. The first coolant passage 60 also includes a supply passage 61 and an introduction passage 62.

[0026] The supply passage 61 is provided along the central axis 10A on the base end 10b side of the body 10. The introduction passage 62 curves radially outward from the end of the supply passage 61 on the tip end 10t side of the body 10, and further extends toward the tip end 10t of the body 10. The cutting edge cooling passage 40 and the chip discharge passage 50 are branched off from the end of the introduction passage 62 on the tip end 10t side, respectively (see Figure 9).

[0027] The cutting edge cooling channel 40 is primarily formed as a channel for supplying coolant to cool the tip cutting edge 81 and the outer peripheral cutting edge 82 of the cutting insert 80. The cutting edge cooling channel 40 has a discharge port 42, which is located in a position suitable for discharging coolant toward the tip cutting edge 81 and the outer peripheral cutting edge 82 of the cutting insert 80, for example, in the vicinity of the insert pocket 20 (more specifically, in the vicinity of the base end 10b side of the insert pocket 20, such that a part of the discharge port 42 overlaps with the insert pocket 20) (see Figures 1, 9, etc.). The shape of the discharge port 42 may be circular, or it may be non-circular in a way that makes it easier to ensure rigidity around the discharge port 42.

[0028] The cutting edge cooling channel 40, which branches off from the introduction channel 62, may be formed in a nearly straight line toward the tip portion 10t, or it may be formed in a non-linear shape that curves along the way. In the cutting tool 1 of this embodiment, the cutting edge cooling channel 40 extends nearly straight from the branching point in the introduction channel 62 toward the tip portion 10t of the body 10, and curves radially inward toward the body 10 at a curved portion 43 provided just before the discharge port 42 (see Figure 9).

[0029] The chip discharge channel 50 is primarily formed as a channel for supplying coolant to improve chip discharge performance during cutting. The chip discharge channel 50 extends away from the cutting edge cooling channel 40 from the branching point in the introduction channel 62 and extends along the outer circumference of the body 10 toward the tip 10t (see Figure 9). At the tip 10t of the body 10, the chip discharge channel 50 branches into two discharge channels 51a and 51b. These discharge channels 51a and 51b each have discharge ports 52a and 52b, and these discharge ports 52a and 52b are provided on the tip surface 12 of the body 10, which is suitable for improving chip discharge performance (see Figures 1, 9, etc.).

[0030] Here, in the body 10, the wall thickness between the outer surface and the first coolant passage 60 is set to be greater than or equal to a predetermined dimension. For example, at the location where the introduction passage 62 of the first coolant passage 60, which passes near the outer surface of the body 10, is formed, the wall thickness T1 of the thinnest portion between the outer surface of the body 10 and the introduction passage 62, and the wall thickness T2 of the thinnest portion between the lubrication groove 92 of the second coolant passage 90, which will be described later and will be the outer surface of the body 10, and the introduction passage 62 are set to be greater than or equal to a predetermined dimension (see Figure 10). Similarly, at the locations where the discharge passages 51a and 51b of the first coolant passage 60, which pass near the outer surface of the body 10, are formed, the wall thicknesses T3 and T4 of the thinnest portions between the outer surface of the body 10 and the discharge passages 51a and 51b, respectively, are set to be greater than or equal to a predetermined dimension (see Figure 8). In this way, by making the wall thickness between the outer surface of the body 10 and the first coolant passage 60 greater than a predetermined dimension, the cross-sectional area of ​​the first coolant passage 60 can be increased while suppressing a decrease in strength, and more coolant can be supplied to the cutting area through the first coolant passage 60. The predetermined dimension of the wall thickness is preferably 0.3 mm.

[0031] In the first coolant flow path 60, the introduction passage 62 has a smaller flow path cross-section than the supply passage 61, and the cutting edge cooling passage 40 and the chip discharge passage 50 also have smaller flow path cross-sections than the introduction passage 62 (see Figure 9). The specific shape from the supply passage 61 to the discharge ports 42, 52a, and 52b is not particularly limited, but in this embodiment, it is preferable that the first coolant flow path 60 includes at least a portion where the flow path cross-sectional area gradually decreases as it approaches the discharge ports 42, 52a, and 52b from the supply passage 61. In this case, the first coolant flow path 60 does not include any section where the cross-sectional area decreases sharply. Thus, in the first coolant flow path 60, which does not include any points where the cross-sectional area decreases sharply and where the portion where the flow path cross-sectional area decreases gradually, the pressure loss when flowing the coolant is relatively small. Therefore, it is possible to supply the coolant more efficiently towards the tip 10t and increase the flow velocity of the coolant along the way to efficiently cool and remove chips, thereby contributing to the suppression of wear of the cutting insert 80.

[0032] The second coolant passage 90 is formed on the outer circumference of the body 10 to supply coolant toward the tip portion 10t of the body 10. In this embodiment, the second coolant passage 90 in the body 10 is provided on the outer circumference of the body 10, excluding the outer circumference of the shank portion 14. In other words, the second coolant passage 90 is not provided on the shank portion 14 that is fitted into the sleeves 101A and 101B and mounted on the sleeves 101A and 101B (see Figures 1 and 7, etc.).

[0033] The second coolant passage 90 is composed of three lubrication grooves 91, 92, and 93 (see Figures 1, 2, 4, and 5). The ends of the lubrication grooves 91, 92, and 93 constituting the second coolant passage 90 are located at the base end 10b side of the body 10 where the stepped portion 15 is located (see Figures 1, 2, 4, and 5). Two of these lubrication grooves, 91 and 92, have their tip ends 10t side reaching the tip surface 12 of the body 10 (see Figures 1 and 8). These lubrication grooves 91 and 92 are located on both sides of the discharge ports 52a and 52b of the chip discharge passage 50 of the first coolant passage 60 when viewed from the tip of the body 10 (see Figures 1 and 8). Furthermore, one of these lubrication grooves 91, 92, and 93, lubrication groove 93, has its tip 10t side reach approximately the vicinity of the insert pocket 20 (see Figures 1 and 7, etc.).

[0034] The lubrication grooves 91, 92, and 93 constituting the second coolant passage 90 may be composed of grooves with a curved, arc-shaped cross-section, as in this embodiment (see Figure 10, etc.), or they may be composed of grooves of other shapes. These lubrication grooves 91, 92, and 93 are formed parallel to the central axis 10A of the body 10 and straight along the central axis 10A (see Figures 1, 2, 4, and 5, etc.).

[0035] The cutting tool 1 is mounted on a machine tool with the shank portion 14 on the base end 10b side of the body 10 attached to the sleeve 101A (see Figures 11 and 12). The cutting tool 1 is also mounted on a machine tool with the shank portion 14 on the base end 10b side of the body 10 attached to the sleeve 101B with discharge holes (see Figures 13 and 14). These sleeves 101A and 101B are formed in a cylindrical shape with mounting holes 102, which serve as a passage for supplying coolant from the machine tool to the cutting tool 1. The sleeve 101B with discharge holes has four discharge holes 103 formed on the inner circumference of the mounting hole 102, spaced apart in the circumferential direction (see Figures 13 and 14). When the cutting tool 1 is mounted on the sleeve 101B with discharge holes, the lubrication grooves 91, 92, and 93 that constitute the second coolant passage 90 of the body 10 are positioned in the same circumferential position as three of the four discharge holes 103 of the sleeve 101B (see Figure 14). Therefore, by mounting the cutting tool 1 on the sleeve 101B with discharge holes, the lubrication grooves 91, 92, and 93 that constitute the second coolant passage 90 of the body 10 are positioned on the axial extension of the three discharge holes 103 of the sleeve 101B (see Figures 13 and 14).

[0036] The cutting tool 1 configured as described above is used by the user under various conditions. For example, it can be used for external supply, where coolant is supplied from outside the body 10 of the cutting tool 1 to the gap between the outer circumference of the body 10 and the machined hole H in the workpiece; for internal supply, where coolant is supplied from the machine tool side to the inside of the cutting tool 1 through the mounting holes 102 of the sleeves 101A and 101B; or, in some cases, both external and internal supply are performed simultaneously. Examples of use with various supply methods will be described below.

[0037] (Example of supply relying solely on external sources) In the case of external supply only, the body 10 of the cutting tool 1 is mounted on a sleeve 101A without an ejection hole 103 and placed on a machine tool (see Figures 11 and 12). Then, coolant is supplied from outside the body 10 of the cutting tool 1 into the gap between the outer circumference of the body 10 and the machining hole H in the workpiece.

[0038] In the case of this external supply only, the coolant is supplied not only through the gap between the outer circumference of the body 10 and the inner circumference of the machined hole H in the workpiece, but also through the lubrication grooves 91, 92, and 93 that constitute the second coolant flow path 90 formed in the body 10 to the cutting area by the tip cutting edge 81 and the outer cutting edge 82.

[0039] If the cutting tool 1's body 10 is not provided with a second coolant passage 90, coolant can only be supplied through the narrow gap between the outer circumference of the body 10 and the inner circumference of the machined hole H. However, with a cutting tool 1 equipped with a body 10 having a second coolant passage 90, the externally supplied coolant smoothly enters the inside of the machined hole H through the second coolant passage 90, allowing a larger amount of coolant to be supplied to the cutting area.

[0040] (Example of supply using only internal resources) In the internal supply of coolant to the first coolant passage 60 of the body 10 of the cutting tool 1, there are two types of internal supply: one using a sleeve 101A without a discharge hole 103 (see Figures 11 and 12), and another using a sleeve 101B with a discharge hole 103 (see Figures 13 and 14).

[0041] (1) Internal supply using sleeve 101A without discharge hole 103 In the case of internal supply only using sleeve 101A without discharge holes 103 (see Figures 11 and 12), coolant is supplied from the machine tool side to the cutting tool 1 through the mounting hole 102 of sleeve 101A. The coolant then passes through the supply passage 61 and introduction passage 62 that constitute the first coolant passage 60 of the body 10 and is sent to the cutting edge cooling passage 40 and the chip discharge passage 50. The coolant sent to the cutting edge cooling passage 42 is discharged toward the cutting insert 80 from the discharge port 42 which opens near the cutting insert 80, and the coolant sent to the chip discharge passage 50 is branched into two discharge passages 51a and 51b and discharged from discharge ports 52a and 52b and sent to the cutting area.

[0042] In this case, if a second coolant passage 90 is formed in the shank portion 14 of the body 10, the coolant supplied from the sleeve 101A to the first coolant passage 60 may leak out of the second coolant passage 90, causing the supply pressure to drop and potentially reducing chip discharge efficiency.

[0043] In contrast, in this embodiment, the second coolant passage 90 is provided on the outer circumference of the body 10, excluding the outer circumference of the shank portion 14. In other words, the second coolant passage 90 is not provided on the shank portion 14 that is attached to the sleeve 101A. Therefore, when supplying coolant from the sleeve 101A to the first coolant passage 60, it is possible to suppress the decrease in coolant supply pressure due to coolant leaking out of the second coolant passage 90. As a result, coolant can be smoothly delivered to the cutting area through the first coolant passage 60, and chips can be discharged effectively.

[0044] (2) Internal supply using sleeve 101B having discharge hole 103 Even when using only internal supply with a sleeve 101B having a discharge hole 103 (see Figures 13 and 14), coolant is supplied from the machine tool side to the cutting tool 1 through the mounting hole 102 of the sleeve 101B. The coolant then passes through the supply passage 61 and introduction passage 62 that constitute the first coolant passage 60 of the body 10 and is sent to the cutting edge cooling passage 40 and the chip discharge passage 50. The coolant sent to the cutting edge cooling passage 42 is discharged toward the cutting insert 80 from the discharge port 42 which opens near the cutting insert 80, and the coolant sent to the chip discharge passage 50 is branched into two discharge passages 51a and 51b and discharged from discharge ports 52a and 52b and sent to the cutting area.

[0045] Furthermore, a portion of the coolant supplied from the machine tool side through the mounting hole 102 of the sleeve 101B is discharged from the discharge hole 103 of the sleeve 101B toward the tip 10t of the body 10 of the cutting tool 1. This coolant then flows into the lubrication grooves 91, 92, and 93 that constitute the second coolant passage 90, which are arranged at the same position in the circumferential direction, without being repelled by the body 10. As a result, the coolant discharged from the discharge hole 103 can be smoothly delivered to the cutting area through the lubrication grooves 91, 92, and 93 of the second coolant passage 90.

[0046] (Examples of supply via external and internal sources) In the case of external and internal supply, the body 10 of the cutting tool 1 is mounted on a sleeve 101A without a discharge hole 103 and installed on the machine tool (see Figures 11 and 12). Coolant is then supplied from outside the body 10 of the cutting tool 1 into the gap between the outer circumference of the body 10 and the machining hole H in the workpiece, and coolant is also supplied from the machine tool side to the cutting tool 1 through the mounting hole 102 of the sleeve 101A.

[0047] Then, the coolant supplied from outside the body 10 of the cutting tool 1 into the gap between the outer circumference of the body 10 and the machined hole H in the workpiece is sent not only through the gap between the outer circumference of the body 10 and the inner circumference of the machined hole H in the workpiece, but also through the lubrication grooves 91, 92, and 93 that constitute the second coolant flow path 90 formed in the body 10 to the cutting point in the workpiece by the tip cutting edge 81 and the outer cutting edge 82. Furthermore, the coolant supplied from the machine tool side to the cutting tool 1 through the mounting hole 102 of the sleeve 101A passes through the supply path 61 and introduction path 62 that constitute the first coolant flow path 60 of the body 10, and is discharged from the discharge port 42 of the cutting edge cooling flow path 40 and the discharge ports 42, 52a, and 52b of the chip discharge flow path 50, and sent to the cutting insert 80 and the cutting point. In this way, the cutting tool 1 can supply a sufficient amount of coolant to the cutting point at the tip of the tool by both external and internal supply.

[0048] Furthermore, if the internally supplied coolant increases the hydraulic pressure at the cutting area, it becomes difficult for the externally supplied coolant to be delivered to the tool tip. Therefore, when supplying coolant by both external and internal means, it is preferable to suppress the hydraulic pressure of the internally supplied coolant so that the externally supplied coolant can be smoothly delivered to the tool tip.

[0049] In the body 10 and cutting tool 1 of this embodiment as described above, a sufficient amount of coolant is supplied to the cutting area at the tip of the tool by internal supply through the first coolant passage 60 and external supply through the second coolant passage 90, thereby enabling smooth chip evacuation and a longer tool life.

[0050] This disclosure is not limited to the above-mentioned specific examples, and any modifications made to these examples by those skilled in the art are also included within the scope of this disclosure, as long as they retain the features of this disclosure. The elements, their arrangement, conditions, shapes, etc., of each of the above-mentioned specific examples are not limited to those exemplified and can be modified as appropriate. The elements of each of the above-mentioned specific examples can be combined in different ways as appropriate, as long as no technical inconsistencies arise. [Explanation of symbols]

[0051] 1 cutting tools 10 Body 10A center shaft 10b Base end 10t tip 14. Shank (holding part) 40 Cutting edge cooling channel (first coolant channel) 50. Chip discharge channel (first coolant channel) 60 First coolant flow path 80 cutting inserts 81 Cutting edge 82 Outer edge cutting edge 90 Second coolant flow path 91, 92, 93 Lubrication groove (second coolant passage) 101A, 101B sleeves 102 Mounting hole (connecting passage) 103 Discharge hole T1, T2, T3, T4 wall thickness

Claims

1. A cutting tool body that processes a workpiece using a cutting edge positioned at the tip and a cutting edge positioned at the outer circumference, A first coolant flow path is provided inside and extends from the base end to the tip, A groove-shaped second coolant flow path is provided on the outer circumference and extends along the central axis, Equipped with, body.

2. The base end is a retaining part that is fitted into a cylindrical sleeve and attached to the sleeve. The second coolant passage is not provided in the holding portion. The body according to claim 1.

3. The thickness of the thinnest portion between the outer circumferential surface and the first coolant flow path is greater than or equal to a predetermined dimension. The body according to claim 1.

4. A body according to any one of claims 1 to 3, A cutting insert having the aforementioned cutting edge and the aforementioned outer peripheral cutting edge, which is mounted on the body, Equipped with, cutting tools.

5. The second coolant passage is positioned at the same circumferential position with respect to the discharge hole formed in the sleeve from which the coolant is discharged. The cutting tool according to claim 4.

6. The tip cutting edge and the outer peripheral cutting edge are integrally provided at the tip of the body according to any one of claims 1 to 3. cutting tools.

7. The second coolant passage is positioned at the same circumferential position with respect to the discharge hole formed in the sleeve from which the coolant is discharged. The cutting tool according to claim 6.

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