JP2023075401A - Tip replaceable radius end mill - Google Patents

Abstract

To provide a tip replaceable radius end mill in which seating stability of a cutting insert to an insert attachment seat can be enhanced stably.SOLUTION: A tip replaceable radius end mill includes a tool body 2 and a disc-shaped cutting insert. An outer peripheral surface of the cutting insert includes a plurality of restraint surfaces arrayed in an insert circumferential direction. The insert attachment seat 21 includes a pair of seating surfaces 21c, 21d arranged in the insert circumferential direction so as to spaced from each other, where each of the restraint surfaces contacts with the seating surfaces 21c, 21d. The pair of seating surfaces 21c, 21d include an outside seating surface 21c extending toward a tip end side of a tool axial direction as extending to the outside in a tool radial direction, and an inside seating surface 21d extending toward a rear end side of the tool axial direction as extending to the outside in the tool radial direction. When the insert attachment seat 21 is viewed in front from a tool rotation direction, a first inclination angle θ1 formed by the outside seating surface 21c being inclined with respect to a tool central axis is larger than a second inclination angle θ2 formed by the inside seating surface 21d being inclined with respect to the tool central axis.SELECTED DRAWING: Figure 6

Description

The present invention relates to an indexable radius end mill.

Conventionally, indexable radius end mills are known that have a tool body centered on the tool center axis and a disk-shaped cutting insert that is detachably attached to an insert mounting seat arranged on the outer circumference of the tip of the tool body. (For example, Patent Document 1).
In general, indexable radius end mills are often used for cutting such as roughing and semi-finishing, where a large cutting force acts on the cutting insert at high depth of cut and high feed.

Japanese Patent Publication No. 2012-525268

In this type of indexable radius end mill, when the cutting insert receives cutting resistance during cutting, there is a possibility that the state of attachment to the insert mounting seat (seating stability) may become unstable.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an indexable radius end mill capable of stably enhancing the seating stability of a cutting insert on an insert mounting seat.

One aspect of the indexable radius end mill of the present invention comprises a tool body centered on the tool center axis, and a disc-shaped cutting tool detachably attached to an insert mounting seat arranged on the outer periphery of the tip of the tool body. an insert, wherein the cutting insert comprises a pair of plate surfaces facing opposite sides in an insert axial direction in which the insert central axis extends; an outer peripheral surface facing outward in the insert radial direction orthogonal to the insert central axis; At least one of the pair of plate surfaces facing the tool rotation direction about the tool center axis and a cutting edge disposed on a ridge connecting the outer peripheral surface, and the outer periphery The surface has a plurality of constraining surfaces arranged in the circumferential direction of the insert around the center axis of the insert, and the insert mounting seats are arranged in the circumferential direction of the insert at intervals, and the constraining surfaces are in contact with each other. an outer seating surface having a seating surface, the pair of seating surfaces extending toward the tip side in the tool axial direction in which the tool central axis extends as the pair of seating surfaces extends outward in the tool radial direction orthogonal to the tool central axis; an inner seating surface disposed inside the tool radial direction from the outer seating surface and extending toward the rear end side in the tool axial direction toward the outer side in the tool radial direction; A first inclination angle θ1 at which the outer seating surface is inclined with respect to the tool central axis when the insert mounting seat is viewed from the front is a second inclination angle at which the inner seating surface is inclined with respect to the tool central axis. greater than the angle θ2.

In this type of indexable radius end mill, during cutting, of the cutting edge of the cutting insert, the arc-shaped portion (outer corner) located at the tip in the tool axial direction and the outer end in the tool radial direction is Cut into the cutting material. At this time, the force (cutting resistance) that the cutting insert receives during cutting includes a component force directed inward in the tool radial direction and a component force directed toward the rear end side in the tool axial direction. The direction of the resultant force of each component force is a direction inclined with respect to the tool central axis. Specifically, when the insert mounting seat is viewed from the front in the direction of rotation of the tool, the direction of this resultant force is the following in the axial direction of the tool as it goes inward in the radial direction of the tool from the arc-shaped portion (cutting portion of the workpiece). It becomes the direction of inclination toward the end side.

In more detail, looking at the insert mounting seat or the rake face of the cutting insert from the direction of tool rotation, the direction of the resultant force is the intersection point (concentrated load point) of the maximum depth of cut of the work material and the cutting edge. It is perpendicular to the tangent line of the cutting edge passing through.

According to the indexable radius end mill of the present invention, the first inclination angle θ1 formed between the outer seating surface and the tool center axis is the second inclination angle formed between the inner seating surface and the tool center axis. It is made larger than the angle θ2. Therefore, the angle of inclination of the outer seating surface with respect to the direction of the resultant force and the angle of inclination of the inner seating surface with respect to the direction of the resultant force can be approximated to each other or have the same value.

Therefore, during cutting, the cutting insert is substantially evenly supported by the pair of seating surfaces, making it difficult for rotational force in the insert circumferential direction to act on the cutting insert. Therefore, the seating stability of the cutting insert on the insert mounting seat is stably enhanced. In addition, the machining accuracy of the cutting insert is maintained well, and the tool life of the cutting insert is extended.

In addition, when ramping the work material using another arc-shaped portion (inner corner) located at the tip of the cutting insert in the axial direction and the inner end in the radial direction of the tool. In the above, when the insert mounting seat is viewed from the front in the direction of rotation of the tool, the direction of the resultant force received by the cutting insert due to cutting is substantially perpendicular to the direction in which the outer seating surface extends.
Therefore, even during ramping, the insert mounting seat can stably support the cutting insert, thereby improving the seating stability of the cutting insert.

In the indexable radius end mill, the cutting edge has a plurality of convex curved edges arranged in the circumferential direction of the insert, and among the plurality of convex curved edges, the tip portion in the tool axial direction and the It is preferable that one end portion in the insert circumferential direction of the predetermined convex curve edge arranged at the outer end portion is positioned closest to the tip side in the tool axial direction in the cutting edge.

In this case, the cutting edge has a plurality of convex curved edges, and during cutting, a predetermined convex curved edge (outer corner) located at the tip in the axial direction of the tool and the outer end in the radial direction of the tool is used to cut the workpiece. Cut into the cutting material. One end of the predetermined convex curve edge in the insert circumferential direction is positioned at the tip in the axial direction of the tool, and functions as a finishing edge for finishing the machined surface of the workpiece. In addition, the portion of the predetermined convex curve edge other than the one end in the circumferential direction of the insert functions as a major cutting edge that makes a large cut into the machined surface of the workpiece and plays a major role in generating chips.
According to the above configuration, the cutting edge can stably function at each position of the convex curve edge in the circumferential direction of the insert.

In the indexable radius end mill, the outer peripheral surface has a protrusion disposed between the constraining surfaces adjacent to each other in the insert circumferential direction and protruding outward in the insert radial direction from the constraining surface. A plurality of portions are provided on the outer peripheral surface so as to be alternately arranged in the restraining surface and the insert circumferential direction. , is preferably located on the outer peripheral surface closest to the tip side in the axial direction of the tool.

In this case, a predetermined protrusion is arranged on the side opposite to the tool rotation direction (opposite tool rotation direction) of the portion of the cutting edge positioned at the tip in the tool axial direction. That is, the thickness of the cutting insert is ensured at the tip position in the axial direction of the tool. It is possible to increase the strength of the cutting insert at the tip position in the axial direction of the tool.

In the indexable radius end mill, the plurality of constraining surfaces are arranged at equal pitches in the circumferential direction of the insert, and the cutting edge has a plurality of convex curved blades arranged at equal pitches in the circumferential direction of the insert, and The center of the face in the circumferential direction of the insert and the center of the convex curve edge in the circumferential direction of the insert are displaced from each other in the circumferential direction of the insert, and a pair of restraining surfaces adjacent to each other in the circumferential direction of the insert. and the center of the convex curve cutting edge in the insert circumferential direction are displaced from each other in the insert circumferential direction.

In the indexable radius end mill of the present invention, as described above, the first inclination angle θ1 of the outer seating surface and the second inclination angle θ2 of the inner seating surface are different from each other. , the center of the restraint surface in the insert circumferential direction, and the center between a pair of restraint surfaces adjacent in the insert circumferential direction, respectively, are shifted in the insert circumferential direction, so that the convex curved cutting edge used for cutting can be effectively can function.

In the indexable radius end mill, the constraining surface includes a flat portion parallel to the central axis of the insert, and the constraining surface is arranged side by side with the flat portion in the axial direction of the insert, and the restraint surface is arranged in parallel with the flat portion in the axial direction of the insert. an inclined surface portion extending radially outward of the insert, the outer seating surface contacting one of the flat portion and the inclined surface portion, and the inner seating surface contacting the flat portion and the inclined surface portion; preferably contact with the other.

In this case, the outer seating surface or the inner seating surface comes into contact with the flat portion, so that the cutting insert can be easily positioned in the insert mounting seat in the circumferential direction of the insert, and the cutting insert can move around the insert during cutting. Rotation in the direction is suppressed.
In addition, since the outer seating surface or the inner seating surface presses the inclined surface portion, the same effect as the flat surface portion described above can be obtained. Lifting of the insert is suppressed.

In the indexable radius end mill, the plurality of restraint surfaces include a first restraint surface having the flat portion arranged in the tool rotation direction and the inclined surface portion arranged on the side opposite to the tool rotation direction; a second constraint surface on which the inclined surface portion is arranged in the tool rotation direction and the flat portion is arranged on the side opposite to the tool rotation direction, wherein the first constraint surface and the second constraint surface are: It is preferable that the inserts are alternately arranged in the circumferential direction of the insert.

In this case, the cutting insert can be a double-sided type having a symmetrical inverted shape while exhibiting the above-described effects.

According to the indexable radius end mill of the aspect of the present invention, it is possible to stably improve the seating stability of the cutting insert on the insert mounting seat.

FIG. 1 is a perspective view showing an indexable radius end mill according to the present embodiment, showing one of a plurality of cutting inserts and omitting the other cutting inserts. FIG. 2 is a bottom view of the indexable radius end mill as seen from the tool axis direction, showing one of a plurality of cutting inserts and omitting the other cutting inserts. FIG. 3 is a side view of the indexable radius end mill shown in arrow III in FIG. FIG. 4 is a side view of the indexable radius end mill shown in arrow IV in FIG. FIG. 5 is a side view showing a part of the indexable radius end mill, more specifically, a front view of the cutting insert and the insert mounting seat from the tool rotation direction. FIG. 6 is a side view showing a part of the tool body, more specifically, a front view of the insert mounting seat from the tool rotation direction. FIG. 7 is a perspective view showing the vicinity of the insert mounting seat of the tool body. FIG. 8 is a cross-sectional view showing the VIII-VIII cross section of FIG. 9 is a cross-sectional view showing the IX-IX cross section of FIG. 5. FIG. FIG. 10 is a perspective view showing a cutting insert; 11(a) is a plan view of the cutting insert viewed from the insert axial direction, and FIG. 11(b) is a side view of the cutting insert viewed from the insert radial direction. FIG. 12 is a sectional view showing the XII-XII section of FIG. 11(a). FIG. 13 is a sectional view showing the XIII-XIII section of FIG. 11(a). FIG. 14 is a side view showing part of the indexable radius end mill of the first modification (near the outer seating surface). FIG. 15 is a bottom view showing a portion (in the vicinity of the inner seating surface) of the indexable radius end mill of the first modified example. FIG. 16 is a perspective view showing a cutting insert included in an indexable radius end mill of the second modification. FIG. 17 is a cross-sectional view showing a cutting insert of a second modification.

An indexable radius end mill 10 according to one embodiment of the present invention will be described with reference to the drawings.

[Schematic configuration of indexable radius end mill]
The indexable radius end mill 10 of the present embodiment is a milling tool (cutting tool) for milling (cutting) a workpiece made of metal or the like. The indexable radius end mill 10 is mainly used for milling, such as rough machining and semi-finishing, which requires high cutting depth and high feed cutting conditions. The indexable radius end mill 10 may also be referred to as an indexable high-feed cutter, an indexable milling tool, or the like.

As shown in FIGS. 1 to 4, the indexable radius end mill 10 includes a columnar or cylindrical tool body 2 centered on the tool center axis O, and a disk-shaped A cutting insert 3 and a fixing member 4 for fixing the cutting insert 3 to the tool body 2 are provided. A plurality of cutting inserts 3 are provided on the outer peripheral portion of the tool body 2 at intervals. 1 to 4 show one of the plurality of cutting inserts 3 attached to the tool body 2, and the other cutting inserts 3 are omitted.

[Definition of direction]
In this embodiment, the direction in which the tool center axis O of the tool body 2 extends, that is, the direction along the tool center axis O is called the tool axis direction. Of the axial directions of the tool, the direction from the first end 2a to the second end 2b of the tool body 2 is called the rear end side, and the direction from the second end 2b to the first end 2a is called the front end side. .

A direction orthogonal to the tool central axis O is called a tool radial direction. In the tool radial direction, the direction approaching the tool center axis O is called the inside in the tool radial direction, and the direction away from the tool center axis O is called the outside in the tool radial direction.

The direction of rotation around the tool center axis O is called the tool circumferential direction. Of the tool circumferential directions, the direction in which the tool body 2 is rotated during cutting is called the tool rotation direction T, and the rotation direction opposite to this is called the side opposite to the tool rotation direction T or the anti-tool rotation direction.
In this embodiment, as shown in FIG. 2, when the first end 2a of the tool body 2 is viewed from the front in the tool axial direction (that is, the tool body 2 is viewed from the tip side in the tool axial direction), the tool central axis The counterclockwise rotation direction about O corresponds to the tool rotation direction T, and the clockwise rotation direction corresponds to the anti-tool rotation direction.

In this embodiment, as shown in FIGS. 10 to 13, the direction in which the insert center axis A of the cutting insert 3 extends, that is, the direction along the insert center axis A is called the insert axial direction. The insert axial direction corresponds to the plate thickness direction of the cutting insert 3 . The cutting insert 3 has a pair of plate surfaces 31 and 32 facing opposite sides in the insert axial direction. In the axial direction of the insert, the direction from one plate surface (front surface) 31 to the other plate surface (back surface) 32 is called the back side of the insert axial direction, and the direction from the other plate surface 32 to the one plate surface 31 The direction is called the face side of the insert axial direction.

A direction orthogonal to the insert central axis A is called an insert radial direction. Of the insert radial directions, the direction closer to the insert center axis A is called the insert radial inside, and the direction away from the insert center axis A is called the insert radial outside.

The direction of rotation around the insert center axis A is called the insert circumferential direction. A predetermined rotational direction of the insert circumferential direction is called one side C1 of the insert circumferential direction, and the opposite rotational direction thereof is called the other side C2 of the insert circumferential direction.
In this embodiment, as shown in FIG. 11A, when one plate surface 31 is viewed from the insert axial direction (that is, the cutting insert 3 is viewed from the surface side in the insert axial direction), the insert center axis A corresponds to one side C1 in the circumferential direction of the insert, and the counterclockwise direction of rotation corresponds to the other side C2 in the circumferential direction of the insert.

[Tool body]
The tool body 2 is made of metal such as steel. As shown in FIGS. 1 to 4, the tool body 2 has a substantially columnar or substantially cylindrical shape centered on the tool central axis O. As shown in FIGS. Note that the tool body 2 may be disc-shaped or the like. The tool body 2 is detachably attached to a spindle of a machine tool (not shown). Specifically, the spindle of the machine tool holds at least the second end 2b of the tool body 2, ie the rear end. The tool body 2 is rotated in the tool rotation direction T by the spindle of the machine tool during cutting. In this embodiment, the outer diameter of the tip portion of the tool body 2 in the tool axial direction is slightly larger than the outer diameter of the rear end portion.

The tool body 2 has an insert mounting seat 21 and a chip pocket 22 . Although not shown, the tool body 2 may further have coolant holes.

The insert mounting seat 21 is arranged at the distal end portion of the tool body 2 in the tool axial direction and the outer end portion in the tool radial direction. That is, the insert mounting seat 21 is arranged on the tip outer periphery of the tool body 2 . The insert mounting seat 21 is recessed from the tip surface and the outer peripheral surface of the tool body 2 .

A plurality of insert mounting seats 21 are provided on the tool body 2 . The plurality of insert mounting seats 21 are spaced apart from each other in the circumferential direction of the tool. In this embodiment, seven insert mounting seats 21 are provided side by side in the tool circumferential direction. The plurality of insert mounting seats 21 have the same shape. A cutting insert 3 is attached to each insert mounting seat 21 .

As shown in FIGS. 6 and 7, the insert mounting seat 21 has a bottom surface 21a, a female screw hole 21b, and a pair of seating surfaces 21c and 21d.

The bottom surface 21a has a planar shape facing the tool rotation direction T. As shown in FIG. In this embodiment, the bottom surface 21a is a circular ring-shaped flat surface. The bottom surface 21a is inclined with respect to the central axis O of the tool. Specifically, the bottom surface 21a is an inclined surface extending in the tool rotation direction T toward the rear end side in the tool axial direction.

The female screw hole 21b opens inside (central portion) of the bottom surface 21a. The female screw hole 21b is a through hole or a blind hole extending in a direction substantially orthogonal to the direction in which the bottom surface 21a widens. In the present embodiment, the female screw hole 21b is a through hole, and opens also to the chip pocket 22 adjacent to the insert mounting seat 21 in which the female screw hole 21b is arranged in the anti-rotation direction of the tool. The female screw hole 21b has a female screw portion on its inner peripheral surface.

The pair of seating surfaces 21c and 21d are arranged in the tool rotation direction T relative to the bottom surface 21a. The pair of seating surfaces 21c and 21d are spaced apart from each other around the center axis of the female screw hole 21b. That is, when the cutting insert 3 is attached to the insert mounting seat 21, the pair of seating surfaces 21c and 21d are spaced from each other in the circumferential direction of the insert (see FIG. 5).

As shown in FIG. 6, the pair of seating surfaces 21c and 21d are composed of an outer seating surface 21c extending toward the distal end side in the tool axial direction as it goes outward in the tool radial direction, and an outer seating surface 21c extending further toward the tool radial direction than the outer seating surface 21c. and an inner seating surface 21d that is arranged inside and extends toward the rear end side in the tool axial direction as it goes outward in the tool radial direction.

A dashed-dotted line indicated by symbol O' in FIG. 6 represents an imaginary straight line that intersects the insert central axis A of the cutting insert 3 (not shown) and is parallel to the tool central axis O. As shown in FIG. As shown in FIG. 6, when the insert mounting seat 21 is viewed from the front in the tool rotation direction T, the first inclination angle The surface 21d is larger than the second inclination angle θ2 at which the surface 21d is inclined with respect to the imaginary straight line O′, that is, the tool central axis O.

The first tilt angle θ1 is, for example, 60° or more and 75° or less. Also, the second tilt angle θ2 is, for example, 15° or more and 30° or less. A difference (θ1−θ2) between the first tilt angle θ1 and the second tilt angle θ2 is, for example, 30° or more and 60° or less. The sum (θ1+θ2) of the first tilt angle θ1 and the second tilt angle θ2 is, for example, 90°. The sum (θ1+θ2) is preferably, for example, 80° or more and 100° or less.
In this embodiment, for example, the first tilt angle θ1 is 67.5° and the second tilt angle θ2 is 22.5°. Also, the difference (θ1−θ2) is 45°, and the sum (θ1+θ2) is 90°.

As shown in FIG. 7, the outer seating surface 21c is planar. In the present embodiment, the outer seating surface 21c is a square plane, specifically, a rectangular plane extending in the circumferential direction of the insert. In addition, the inner seating surface 21d is planar. In this embodiment, the inner seating surface 21d is a rectangular plane, specifically, a rectangular plane extending in the circumferential direction of the insert.

In this embodiment, the outer seating surface 21c is positioned in the tool rotation direction T relative to the inner seating surface 21d. In other words, the outer seating surface 21c is located closer to the surface side in the axial direction of the insert than the inner seating surface 21d.

As shown in FIGS. 1 to 4, the chip pocket 22 is arranged at the distal end portion of the tool body 2 in the tool axial direction and the outer end portion in the tool radial direction. That is, the chip pocket 22 is arranged on the tip outer periphery of the tool body 2 . The chip pocket 22 is recessed from the tip surface and the outer peripheral surface of the tool body 2 . The chip pocket 22 is in the shape of a notch larger than the insert mounting seat 21 .

A plurality of chip pockets 22 are provided in the tool body 2 . The plurality of chip pockets 22 are arranged at intervals in the circumferential direction of the tool. In this embodiment, seven chip pockets 22 are provided side by side in the tool circumferential direction. Each chip pocket 22 is arranged adjacent to each insert mounting seat 21 in the tool rotation direction T and connected to each insert mounting seat 21 .

The length in which the chip pocket 22 is recessed from the tip end face of the tool body 2 toward the rear end side in the tool axial direction, that is, the depth in the tool axial direction is is longer than the length recessed toward the rear end side of the The length in which the chip pocket 22 is depressed from the outer peripheral surface of the tool body 2 toward the inner side in the tool radial direction, that is, the depth in the tool radial direction is determined by the distance between the insert mounting seat 21 and the inner side in the tool radial direction from the outer peripheral surface of the tool body 2. greater than the recessed length toward

Although not shown in particular, when the tool body 2 has a coolant hole, for example, the following configuration can be adopted.
The coolant hole extends inside the tool body 2 and penetrates the tool body 2 . A plurality of coolant holes are provided in the tool body 2 . The plurality of coolant holes are spaced apart from each other in the circumferential direction of the tool. The number of coolant holes is the same as the number of insert mounting seats 21 or a multiple thereof. The coolant hole is connected to coolant supply means such as a pump through an internal flow path, piping, or the like of the spindle of the machine tool. Coolant such as cutting fluid and compressed air is supplied to the coolant hole from a coolant supply means.

The outer end of the coolant hole in the tool radial direction, that is, the spout opens into the chip pocket 22 . The coolant hole ejects coolant toward the cutting edge 34 of the cutting insert 3 mounted on the insert mounting seat 21 and the machined portion of the work material.

[Cutting insert]
Next, the cutting insert 3 will be explained. The cutting insert 3 is made of cemented carbide, for example. The cutting insert 3 is detachably attached to the insert mounting seat 21 . The number of cutting inserts 3 is the same as the number of insert mounting seats 21, which is seven in this embodiment. A plurality of cutting inserts 3 are arranged on the tip outer peripheral portion of the tool body 2 at intervals in the tool circumferential direction.

The cutting insert 3 is a so-called round piece insert, and has a disc shape centered on the insert central axis A. As shown in FIG. The cutting insert 3 of this embodiment has a symmetrical shape with the front and back reversed. That is, the cutting insert 3 is a double-sided insert that can perform cutting even when it is attached to the insert mounting seat 21 in an inverted posture in the insert axial direction.

As shown in FIGS. 10 to 13, the cutting insert 3 has a pair of plate surfaces 31 and 32 extending in a direction substantially perpendicular to the center axis A of the insert and a pair of plate surfaces 31 and 32 facing outward in the radial direction of the insert. an outer peripheral surface 33 connected to a pair of plate surfaces 31 and 32, a cutting edge 34 arranged on a ridgeline portion where at least one of the plate surfaces 31 and 33 is connected to the pair of plate surfaces 31 , 32 and through holes 35 . In this embodiment, the cutting insert 3 is of a double-sided type, and the cutting edge 34 is also arranged on the ridgeline portion where the other plate surface 32 and the outer peripheral surface 33 are connected.

One plate surface 31 faces the surface side in the axial direction of the insert. One plate surface 31 may be called the front surface 31 . The other plate surface 32 faces the back side in the axial direction of the insert. The other plate surface 32 may be called the back surface 32 .

In this embodiment, the cutting insert 3 is a double-sided type, and the pair of plate surfaces 31 and 32 have the same configuration. Therefore, in the present embodiment, one plate surface 31 will be described, and the description of the other plate surface 32 will be omitted. Although not shown, at least one of the pair of plate surfaces 31 and 32 may be provided with an identification mark for identifying each plate surface 31 and 32 .

The plate surface 31 has a substantially circular ring shape around the center axis A of the insert. The plate surface 31 has a mounting surface 31a, a plurality of rake surfaces 31b arranged in the insert circumferential direction, and a plurality of inclined surfaces 31c arranged in the insert circumferential direction.

The mounting surface 31a is arranged inside the plate surface 31 in the radial direction of the insert. The mounting surface 31a is planar and extends in a direction perpendicular to the center axis A of the insert. The mounting surface 31a is a circular ring-shaped flat surface.

The rake face 31 b is arranged on the outer peripheral portion of the plate face 31 . The rake face 31 b is arranged adjacent to the cutting edge 34 inside the cutting edge 34 in the radial direction of the insert. A plurality of rake faces 31b are provided side by side in the circumferential direction of the insert, and in this embodiment, four rake faces 31b are provided at equal pitches in the circumferential direction of the insert.

As shown in FIG. 11(a), each rake face 31b has a generally arcuate belt shape extending in the circumferential direction of the cutting insert 3 in a plan view of the cutting insert 3 viewed from the axial direction of the insert. In this embodiment, the length (width) of the rake face 31b in the insert radial direction is constant along the insert circumferential direction. Further, as shown in FIG. 10, in the present embodiment, each rake surface 31b of the plate surface 31 has a convex curved shape that protrudes toward the surface side in the axial direction of the insert.

As shown in FIGS. 12 and 13, the rake face 31b of the plate face 31 extends from the cutting edge 34 toward the inner side in the insert radial direction and toward the back side in the insert axial direction. That is, the rake face 31b has an inclined surface shape that is inclined with respect to a virtual plane (not shown) extending in a direction perpendicular to the center axis A of the insert. Note that the rake face 31b may have a planar shape extending in a direction perpendicular to the center axis A of the insert.

As shown in FIG. 10, the inclined surface 31c is arranged in a portion of the plate surface 31 between the mounting surface 31a and the rake surface 31b in the radial direction of the insert. The inner peripheral portion of the inclined surface 31c is connected to the mounting surface 31a, and the outer peripheral portion of the inclined surface 31c is connected to the rake surface 31b. A plurality of inclined surfaces 31c are provided side by side in the circumferential direction of the insert, and in this embodiment, four inclined surfaces 31c are provided at equal pitches in the circumferential direction of the insert.

In a plan view of the insert shown in FIG. 11(a), each inclined surface 31c has a substantially arcuate band shape extending in the circumferential direction of the insert. In the present embodiment, the length (width) of the inclined surface 31c in the radial direction of the insert increases toward the one side C1 in the circumferential direction of the insert.

As shown in FIGS. 12 and 13, the inclined surface 31c of the plate surface 31 extends toward the back side in the axial direction of the insert as it goes inward in the radial direction of the insert. That is, the inclined surface 31c is inclined with respect to a virtual plane (not shown) extending in a direction perpendicular to the center axis A of the insert. Also, the angle at which the inclined surface 31c is inclined with respect to the virtual plane increases toward the other side C2 in the circumferential direction of the insert.
The amount of displacement (that is, inclination) toward the axial direction of the insert per unit length along the insert radial direction of the inclined surface 31c is greater than the amount of displacement of the rake surface 31b.

As shown in FIGS. 10-13, the outer peripheral surface 33 extends in the circumferential direction of the insert. The outer peripheral surface 33 has an annular shape around the center axis A of the insert. Specifically, the outer peripheral surface 33 is substantially cylindrical.
The outer peripheral surface 33 has a flank 33a, a plurality of restraint surfaces 36 arranged in the insert circumferential direction, and projections 33b arranged between the restraint surfaces 36 adjacent in the insert circumferential direction.

The flank 33a is arranged at least at the end of the outer peripheral surface 33 on the surface side in the axial direction of the insert. The flank 33a is arranged adjacent to the cutting edge 34 in the axial direction of the insert. The flank 33a extends in the circumferential direction of the insert. In this embodiment, the cutting insert 3 is of a double-sided type, and the flank 33a is also arranged at the end of the outer peripheral surface 33 on the back side in the axial direction of the insert.

The plurality of restraining surfaces 36 are spaced from each other in the circumferential direction of the insert. In this embodiment, eight restraining surfaces 36 are provided along the circumferential direction of the insert. The plurality of restraint surfaces 36 are arranged at equal pitches in the circumferential direction of the insert. That is, in this embodiment, the eight restraining surfaces 36 are arranged in the insert circumferential direction at a pitch of 45° around the insert central axis A when viewed from the insert axial direction.

The restraint surface 36 is recessed inward in the radial direction of the insert from a portion of the outer peripheral surface 33 other than the restraint surface 36 . The restraint surface 36 has a flat portion 36a and an inclined surface portion 36b.
The planar portion 36a has a planar shape parallel to the center axis A of the insert. In the present embodiment, the planar portion 36a has a square shape, and more specifically, has a rectangular shape extending in the circumferential direction of the insert.

The inclined surface portion 36b is arranged side by side with the flat portion 36a in the axial direction of the insert. In this embodiment, the inclined surface portion 36b and the flat surface portion 36a are connected to each other in the insert axial direction. The inclined surface portion 36b has a planar shape that is inclined with respect to the central axis A of the insert. The inclined surface portion 36b extends outward in the insert radial direction as it separates from the flat portion 36a in the axial direction of the insert.

In this embodiment, the inclined surface portion 36b has a quadrangular shape, specifically a trapezoidal shape. A side portion corresponding to the bottom of the trapezoidal inclined surface portion 36b is connected to the flat portion 36a. A side portion corresponding to the upper base of the trapezoidal inclined surface portion 36b is arranged adjacent to the flank surface 33a in the insert axial direction.
The dimension of the inclined surface portion 36b in the circumferential direction of the insert becomes smaller with distance from the flat portion 36a along the axial direction of the insert.

The plurality of constraining surfaces 36 includes a first constraining surface 36A and a second constraining surface 36B.
The first restraining surface 36A has a flat surface portion 36a arranged on the front surface side in the axial direction of the insert, and an inclined surface portion 36b arranged on the rear surface side in the axial direction of the insert. The second restraining surface 36B has an inclined surface portion 36b arranged on the front surface side in the axial direction of the insert, and a flat surface portion 36a arranged on the rear surface side in the axial direction of the insert.

36 A of 1st restraint surfaces are provided in multiple numbers along the insert circumferential direction, and in this embodiment, are provided four at equal pitches in the insert circumferential direction. A plurality of second restraint surfaces 36B are provided along the insert circumferential direction, and in this embodiment, four are provided at equal pitches in the insert circumferential direction. The first constraining surfaces 36A and the second constraining surfaces 36B are arranged alternately in the circumferential direction of the insert. That is, in the present embodiment, the four first restraint surfaces 36A are arranged in the insert circumferential direction at a pitch of 90° around the insert central axis A when viewed from the insert axial direction. In addition, the four second restraint surfaces 36B are arranged in the insert circumferential direction at a pitch of 90° around the insert central axis A when viewed from the insert axial direction.

The protrusion 33b protrudes outward in the radial direction of the insert from the restraining surface 36. As shown in FIG. In this embodiment, the position of the protrusion 33b in the insert radial direction is the same as the position of the flank 33a in the insert radial direction. A plurality of protrusions 33b are provided on the outer peripheral surface 33 so as to alternately line up with the restraint surface 36 in the circumferential direction of the insert. In this embodiment, eight protrusions 33b are provided at equal pitches in the circumferential direction of the insert.

The protrusion 33b extends in the axial direction of the insert. The length (width) of the protruding portion 33b in the insert circumferential direction increases from the central portion of the protruding portion 33b in the insert axial direction toward both end portions. That is, the length of the protrusion 33b in the insert circumferential direction increases as it approaches the cutting edge 34 along the insert axial direction.

The cutting edge 34 has a plurality of convex curved edges 34a arranged in the circumferential direction of the insert. In this embodiment, a plurality of convex curved blades 34a are arranged in the insert circumferential direction at equal pitches, and specifically, four convex curved blades 34a are arranged in the insert circumferential direction. Each convex curved blade 34a has a convex curved shape that is convex toward the surface side in the axial direction of the insert. The central portion of the convex curved edge 34a in the insert circumferential direction is located closer to the surface side in the insert axial direction than both end portions of the convex curved edge 34a in the insert circumferential direction.

11(a), each convex curved cutting edge 34a has an arcuate shape centered on the central axis A of the insert. In this insert plan view, the four convex curved blades 34a are positioned on one imaginary circle (not shown) centered on the central axis A of the insert.

A rake face 31b and an inclined face 31c are arranged in this order on the inner side in the insert radial direction of the convex curve cutting edge 34a toward the inner side in the insert radial direction. The convex curved edge 34a, the rake face 31b, and the inclined face 31c arranged in the insert radial direction have substantially the same length in the insert circumferential direction. Specifically, among the convex curved edge 34a, the rake face 31b, and the inclined face 31c aligned in the insert radial direction, the end of the convex curved edge 34a on one side C1 in the insert circumferential direction and the one side of the insert circumferential direction on the rake face 31b The end portion of C1 and the end portion of one side C1 of the inclined surface 31c in the insert circumferential direction are substantially at the same position in the insert circumferential direction. Further, among the convex curved cutting edge 34a, the rake face 31b, and the inclined face 31c arranged in the insert radial direction, the end portion of the convex curved cutting edge 34a on the other side C2 in the insert circumferential direction and the rake face 31b on the other side C2 in the insert circumferential direction and the end of the inclined surface 31c on the other side C2 in the insert circumferential direction are substantially the same in position in the insert circumferential direction.

As shown in FIG. 10, in this embodiment, of the restraining surface 36 and the convex curved cutting edge 34a that are adjacent in the insert axial direction, the center B of the restraining surface 36 in the insert circumferential direction and the insert circumferential direction center B of the convex curved cutting edge 34a The center E is offset from each other in the circumferential direction of the insert. Specifically, the center B in the insert circumferential direction of the first restraining surface 36A and the center E in the insert circumferential direction of the convex curve cutting edge 34a are offset from each other in the insert circumferential direction. In addition, the center B in the insert circumferential direction of the second restraining surface 36B and the center E in the insert circumferential direction of the convex curve cutting edge 34a are offset from each other in the insert circumferential direction.

In addition, with respect to the pair of restraint surfaces 36 adjacent in the insert circumferential direction and the one convex curved edge 34a adjacent to the pair of restraint surfaces 36 in the insert axial direction, the center of the insert circumferential direction between the pair of restraint surfaces 36 (That is, the center D of the protrusion 33b in the circumferential direction of the insert) and the center E of the convex curve edge 34a in the circumferential direction of the insert are displaced from each other in the circumferential direction of the insert.

Further, in the present embodiment, the center D in the insert circumferential direction of the protrusion 33b arranged on the other side C2 of the first restraint surface 36A in the insert circumferential direction and the one side C1 of the second restraint surface 36B in the insert circumferential direction, and the convex The positions in the insert circumferential direction of the one side C1 of the curved edge 34a in the insert circumferential direction (one end) are substantially the same.
Circumferential centers B, D, and E of the inserts are respectively center lines B, D, and E extending in the axial direction of the inserts passing through the centers of the inserts in the circumferential direction, or simply the center line B of the inserts in the circumferential direction. , D, E.

As shown in FIGS. 12 and 13, the through hole 35 penetrates the cutting insert 3 in the insert axial direction. The through-hole 35 extends in the insert axial direction inside the cutting insert 3 and opens at each central portion of the plate surfaces 31 and 32 . The through-hole 35 is a multistage circular hole centered on the central axis A of the insert. Both ends of the through-hole 35 in the insert axial direction, that is, the inner diameters of the pair of openings are larger than the inner diameter of the central portion of the through-hole 35 in the insert axial direction.

[Fixing member]
As shown in FIGS. 8 and 9, the fixing member 4 is, for example, a clamp screw or the like. The fixing member 4 has a male screw portion. The fixing member 4 is inserted into the through hole 35 of the cutting insert 3 . The male screw portion of the fixing member 4 is screwed into the female screw portion of the female screw hole 21 b of the insert mounting seat 21 . Thereby, the fixing member 4 fixes the cutting insert 3 to the insert mounting seat 21 .

[Mounting posture of the cutting insert to the insert mounting seat, etc.]
Next, each configuration including the mounting attitude, arrangement, etc. in the state where the cutting insert 3 is fixed to the insert mounting seat 21 by the fixing member 4 will be described.

As shown in FIGS. 1 to 5, of a pair of plate surfaces 31 and 32 of the cutting insert 3 arranged on the insert mounting seat 21, one plate surface (surface) 31 faces the tool rotation direction T, and the other A plate surface (rear surface) 32 of the is directed in the counter-rotation direction of the tool. Although not particularly shown, the insert central axis A of the cutting insert 3 arranged in the insert mounting seat 21 extends toward the tip side in the tool axial direction along the tool rotation direction T (see FIG. 4).

As shown in FIGS. 8 and 9, the mounting surface 31a of the other plate surface 32 contacts the bottom surface 21a of the insert mounting seat 21. As shown in FIGS. A pair of seating surfaces 21c and 21d of the insert mounting seat 21 are in contact with the restraining surfaces 36, respectively.

As shown in FIG. 4, when the cutting insert 3 is attached to the insert mounting seat 21, the first restraint surface 36A has a flat portion 36a arranged in the tool rotation direction T and an inclined surface portion 36b arranged in the anti-tool rotation direction. placed. The second restraint surface 36B has an inclined surface portion 36b arranged in the tool rotation direction T, and a flat surface portion 36a arranged in the anti-tool rotation direction.

As shown in FIG. 8, of the pair of seating surfaces 21c and 21d, the outer seating surface 21c contacts one of the flat portion 36a and the inclined surface portion 36b of the restraining surface 36, and contacts the flat portion 36a in this embodiment. do. Specifically, the outer seating surface 21c contacts the flat portion 36a of one first restraining surface 36A among the plurality of first restraining surfaces 36A.

As shown in FIG. 9, of the pair of seating surfaces 21c and 21d, the inner seating surface 21d is in contact with the other of the flat portion 36a and the inclined surface portion 36b of the restraining surface 36, and in this embodiment, the inclined surface portion 36b. do. Specifically, the inner seating surface 21d contacts the inclined surface portion 36b of a first restraining surface 36A different from the one first restraining surface 36A among the plurality of first restraining surfaces 36A.

As shown in FIG. 5 , the cutting edge 34 of the cutting insert 3 arranged in the insert mounting seat 21 protrudes from the tool body 2 to the tip side in the axial direction of the tool and to the outer side in the radial direction of the tool. That is, the cutting edge 34 has a portion arranged to protrude from the tip surface of the tool body 2 toward the tip side in the tool axial direction, and a portion arranged to protrude outward in the tool radial direction from the outer peripheral surface of the tool body 2 . , has

Specifically, in the present embodiment, one of the plurality of convex curved edges 34a of the cutting edge 34 protrudes from the tool body 2 toward the tip side in the tool axial direction and outward in the tool radial direction. During cutting, the one convex curved edge 34a of the cutting edges 34 cuts into the material W to be cut. Hereinafter, the one convex curve blade 34a is referred to as a predetermined convex curve blade 34a.

The predetermined convex curved cutting edge 34a is arranged at the tip in the axial direction of the tool and the outer end in the radial direction of the tool. The predetermined convex curve cutting edge 34a has an end portion on one side C1 in the insert circumferential direction, that is, one end portion, of the cutting edge 34 located closest to the tip side in the tool axial direction. In addition, the end portion of the other side C2 in the insert circumferential direction, that is, the other end portion, of the predetermined convex curve cutting edge 34a is located on the outermost side of the cutting edge 34 in the tool radial direction.

Among the plurality of projections 33b of the cutting insert 3 arranged on the insert mounting seat 21, one projection 33b (hereinafter referred to as a predetermined projection 33b) arranged at the tip in the tool axial direction is It is positioned closest to the tip side in the axial direction of the tool on the outer peripheral surface 33 .
That is, the end portion (one end portion) of the predetermined convex curve cutting edge 34a on one side C1 in the insert circumferential direction and the predetermined protrusion 33b are arranged at substantially the same position in the insert circumferential direction.

[Effects of this embodiment]
In the indexable radius end mill 10 of the present embodiment, during cutting, of the cutting edges 34 of the cutting insert 3, a predetermined convex curved edge 34a ( outer corner) cuts into the workpiece W. At this time, as shown in FIG. 5, the force (cutting resistance) that the cutting insert 3 receives during cutting consists of a component force F1 directed inward in the tool radial direction, a component force F2 directed toward the rear end side in the tool axial direction, including. The direction of the resultant force F3 of the force components F1 and F2 is inclined with respect to the central axis O of the tool. Specifically, as shown in FIG. 5, the direction of the resultant force F3 is determined by looking at the insert mounting seat 21 from the tool rotation direction T in the front direction, and from a predetermined convex curved edge 34a (cutting portion of the workpiece W) to the tool diameter The inclination direction is toward the rear end side in the axial direction of the tool as it goes inward in the direction.

More specifically, when viewing the insert mounting seat 21 or the rake face 31b (surface 31) of the cutting insert 3 from the tool rotation direction T, the direction of the resultant force F3 The direction is orthogonal to the tangent line L of the cutting edge 34 passing through the intersection point (concentrated load point) P with the edge 34 .

According to the indexable radius end mill 10 of this embodiment, as shown in FIG. It is larger than the second inclination angle θ2 formed between the inner seating surface 21d and the tool central axis O (virtual straight line O′). Therefore, the angle α at which the outer seating surface 21c is inclined with respect to the direction of the resultant force F3 and the angle β at which the inner seating surface 21d is inclined with respect to the direction of the resultant force F3 are approximated to each other or have the same value. can do.

Therefore, during cutting, the cutting insert 3 is substantially evenly supported by the pair of seating surfaces 21c and 21d, making it difficult for rotational force to act on the cutting insert 3 in the insert circumferential direction. Therefore, the seating stability of the cutting insert 3 on the insert mounting seat 21 is stably enhanced. Machining accuracy of the cutting insert 3 is maintained well, and the tool life of the cutting insert 3 is extended.

Of the cutting edges 34 of the cutting insert 3, another convex curved edge 34a (inner corner) located at the tip in the axial direction of the tool and the inner end in the radial direction of the tool is used to perform ramping machining on the work material. In this case, when the insert mounting seat 21 is viewed from the front in the tool rotation direction T, the direction of the resultant force (not shown) received by the cutting insert 3 due to cutting is substantially perpendicular to the direction in which the outer seating surface 21c extends. be done.
Therefore, even during ramping, the insert mounting seat 21 can stably support the cutting insert 3, and the seating stability of the cutting insert 3 is improved.

In addition, in this embodiment, the cutting edge 34 has a plurality of convex curved edges 34a. During cutting, predetermined convex curved edges 34a ( outer corner) cuts into the workpiece W. One end of the predetermined convex curve edge 34a in the insert circumferential direction is positioned at the tip in the axial direction of the tool, and functions as a finishing edge for finishing the machined surface of the workpiece W. As shown in FIG. A portion of the predetermined convex curve edge 34a other than the one end in the circumferential direction of the insert functions as a main cutting edge that makes a large cut into the machined surface of the workpiece W and plays a major role in generating chips.
According to the above configuration, the cutting edge 34 can stably function at each position of the predetermined convex curve edge 34a in the insert circumferential direction.

Further, in the present embodiment, of the plurality of protrusions 33b of the cutting insert 3, the predetermined protrusion 33b arranged at the tip in the tool axial direction is positioned closest to the tip in the tool axial direction on the outer peripheral surface 33. .
In this case, on the side opposite to the tool rotation direction T (opposite to the tool rotation direction) of the cutting edge 34 located at the tip in the tool axial direction (one end of the predetermined convex curved edge 34a in the insert circumferential direction), A predetermined protrusion 33b is arranged. That is, the thickness of the cutting insert 3 is ensured at the tip position in the axial direction of the tool. It is possible to increase the strength of the cutting insert 3 at the tip position in the axial direction of the tool.

Further, in the present embodiment, a plurality of restraining surfaces 36 are arranged at equal pitches in the circumferential direction of the insert, and a plurality of convex curved edges 34a are arranged at equal pitches in the circumferential direction of the insert. The center E of the curved edge 34a in the insert circumferential direction is displaced from each other in the insert circumferential direction, and is the center between a pair of restraining surfaces 36 adjacent in the insert circumferential direction (the center of the protrusion 33b in the insert circumferential direction). D and the center E of the convex curve cutting edge 34a in the insert circumferential direction are displaced from each other in the insert circumferential direction.
In the indexable radius end mill 10 of the present embodiment, as described above, the first inclination angle θ1 of the outer seating surface 21c and the second inclination angle θ2 of the inner seating surface 21d are different from each other. Circumferential direction center E is shifted in the insert circumferential direction from center B in the insert circumferential direction of the restraint surface 36 and center D between a pair of restraint surfaces 36 adjacent in the insert circumferential direction, respectively, so that cutting can be performed. The convex curve blade 34a used can be effectively functioned.

In this embodiment, the outer seating surface 21c is in contact with one of the flat portion 36a and the inclined surface portion 36b of the restraining surface 36 (the flat surface portion 36a in this embodiment), and the inner seating surface 21d is the plane of the restraining surface 36. It contacts the other of the portion 36a and the inclined surface portion 36b (the inclined surface portion 36b in this embodiment).
In this case, the outer seating surface 21c or the inner seating surface 21d comes into contact with the flat portion 36a, so that the cutting insert 3 can be easily positioned in the insert mounting seat 21 in the insert circumferential direction. The turning of the cutting insert 3 in the insert circumferential direction is suppressed.
Further, by pressing the inclined surface portion 36b with the outer seating surface 21c or the inner seating surface 21d, the same effect as that of the flat portion 36a can be obtained. Lifting of the cutting insert 3 with respect to the insert mounting seat 21 is suppressed.

Further, in this embodiment, the plurality of restraint surfaces 36 includes a first restraint surface 36A and a second restraint surface 36B, and the first restraint surfaces 36A and the second restraint surfaces 36B are alternately arranged in the circumferential direction of the insert. .
In this case, the cutting insert 3 can be of a double-sided type having a symmetrical shape with the front and back reversed while exhibiting the above-described effects. Specifically, when the cutting insert 3 is turned upside down and mounted on the insert mounting seat 21, the pair of seating surfaces 21c and 21d is the plane of one of the second restraining surfaces 36B of the pair of second restraining surfaces 36B. By contacting the portion 36a and the inclined surface portion 36b of the other second restraint surface 36B, the same effect as described above can be obtained.

Further, in the present embodiment, the first tilt angle θ1 is 60° or more and 75° or less. Also, the second tilt angle θ2 is 15° or more and 30° or less. Also, the difference (θ1−θ2) between the first tilt angle θ1 and the second tilt angle θ2 is 30° or more and 60° or less.
By setting the first tilt angle θ1 to 60° or more, the second tilt angle θ2 to 30° or less, or the difference (θ1−θ2) to 30° or more, The angle α at which the outer seating surface 21c is inclined and the angle β at which the inner seating surface 21d is inclined with respect to the direction of the resultant force F3 can be brought closer to each other more stably.
Further, by setting the first inclination angle θ1 to 75° or less, the second inclination angle θ2 to 15° or more, or the difference (θ1−θ2) to 60° or less, the outer seating surface 21c is Excessive inclination with respect to the tool central axis O and excessive inclination of the inner seating surface 21d with respect to the tool central axis O are suppressed, and the cutting insert 3 is substantially evenly distributed by the pair of seating surfaces 21c, 21d. The aforementioned effect of being supported is stably achieved.

[Other configurations included in the present invention]
It should be noted that the present invention is not limited to the above-described embodiments, and, for example, as described below, changes in configuration can be made without departing from the gist of the present invention. In the drawings of the modification, the same reference numerals are given to the same constituent elements as in the above-described embodiment, and mainly different points will be described below.

In the above-described embodiment, an example was given in which the outer seating surface 21c is located in the tool rotation direction T relative to the inner seating surface 21d, but the present invention is not limited to this.
FIG. 14 is a side view showing a part (near the outer seating surface 21c) of the first modification of the indexable radius end mill 10 described in the above embodiment, and FIG. FIG. 11 is a bottom view showing a part (in the vicinity of the inner seating surface 21d) of the first modified example;

In the first modification shown in FIGS. 14 and 15, the outer seating surface 21c is located on the opposite side of the inner seating surface 21d to the tool rotation direction T (opposite to the tool rotation direction).
Then, as shown in FIG. 14, the outer seating surface 21c contacts one of the flat portion 36a and the inclined surface portion 36b of the restraining surface 36, and contacts the inclined surface portion 36b in this first modification. Specifically, the outer seating surface 21c contacts the inclined surface portion 36b of one first restraining surface 36A among the plurality of first restraining surfaces 36A.

Further, as shown in FIG. 15, the inner seating surface 21d contacts the other of the flat portion 36a and the inclined surface portion 36b of the restraining surface 36, and contacts the flat portion 36a in this first modification. Specifically, the inner seating surface 21d contacts the flat portion 36a of a first restraining surface 36A different from the one first restraining surface 36A among the plurality of first restraining surfaces 36A.
Also in this first modified example, the same effect as the above-described embodiment can be obtained.

In the above-described embodiment, an example in which the restraining surface 36 of the cutting insert 3 has the plane portion 36a and the inclined surface portion 36b was given, but the present invention is not limited to this.
FIG. 16 is a perspective view showing the cutting insert 3 provided in the second modification of the indexable radius end mill 10 described in the above embodiment, and FIG. 2 is a cross-sectional view (longitudinal cross-sectional view) along the axis A; FIG.

In a second modification shown in FIGS. 16 and 17, the restraining surface 36 of the cutting insert 3 has a pair of inclined surface portions 36b aligned in the axial direction of the insert. The pair of inclined surface portions 36b has one inclined surface portion 36ba arranged on the front surface side in the axial direction of the insert and the other inclined surface portion 36bb arranged on the rear surface side in the axial direction of the insert. One inclined surface portion 36ba extends outward in the insert radial direction as it separates from the other inclined surface portion 36bb in the insert axial direction. The other inclined surface portion 36bb extends outward in the insert radial direction as it separates from the one inclined surface portion 36ba in the axial direction of the insert.

Although not shown, when the cutting insert 3 is attached to the insert mounting seat 21, one inclined surface portion 36ba is arranged in the tool rotation direction T, and the other inclined surface portion 36bb is arranged in the opposite direction to the tool rotation direction T. placed on the side.
The outer seating surface 21c contacts one inclined surface portion 36ba, and the inner seating surface 21d contacts the other inclined surface portion 36bb. However, the invention is not limited to this, and the inner seating surface 21d may come into contact with one inclined surface portion 36ba, and the outer seating surface 21c may come into contact with the other inclined surface portion 36bb.

In this second modification, the cutting insert 3 can be easily positioned in the insert mounting seat 21 in the insert circumferential direction by contacting the outer seating surface 21c or the inner seating surface 21d with one inclined surface portion 36ba. Moreover, the turning of the cutting insert 3 in the insert circumferential direction during cutting is suppressed.
Further, by pressing the other inclined surface portion 36bb with the outer seating surface 21c or the inner seating surface 21d, the same effect as the one inclined surface portion 36ba described above can be obtained, and the cutting insert 3 receives cutting resistance during cutting. When this is done, the cutting insert 3 is restrained from floating with respect to the insert mounting seat 21 .

In the above-described embodiment, an example was given in which the cutting insert 3 is a double-sided type with a symmetrical inverted shape, but the present invention is not limited to this. The cutting insert 3 may be a single-sided type with a non-reversed symmetrical shape.

Although not shown, the present invention can also be applied to indexable radius end mills that are different from the above embodiments.
Specifically, in the above-described embodiment, as shown in FIG. Although an example in which the clockwise rotation direction corresponds to the anti-tool rotation direction has been given, the present invention is not limited to this. That is, when the tool body 2 is viewed from the tip end side in the tool axial direction, the clockwise rotation direction around the tool center axis O corresponds to the tool rotation direction T, and the counterclockwise rotation direction corresponds to the counter-tool rotation direction. It may be equivalent. In this case, as shown in FIG. 11(a), when the cutting insert 3 is viewed from the surface side in the axial direction of the insert, the counterclockwise rotational direction around the central axis A of the insert corresponds to one side C1 in the circumferential direction of the insert. , the clockwise rotation direction corresponds to the other side C2 in the circumferential direction of the insert.

The present invention may combine the configurations described in the above-described embodiments and modifications without departing from the gist of the present invention, and addition, omission, replacement, and other modifications of the configuration are possible. . Moreover, the present invention is not limited by the above-described embodiments and the like, but is limited only by the scope of the claims.

According to the indexable radius end mill of the present invention, the seating stability of the cutting insert on the insert mounting seat can be stably enhanced. Therefore, it has industrial applicability.

2 Tool body 3 Cutting insert 10 Indexable radius end mill 21 Insert mounting seat 21c Outer seating surface (seating surface)
21d... Inner seating surface (sitting surface)
31 ... One plate surface (surface)
32 ... The other plate surface (back surface)
33... Peripheral surface 33b... Projection 34... Cutting edge 34a... Convex curved edge 36... Restricted surface 36a... Flat surface part 36b... Inclined surface part 36ba... One inclined surface part 36bb... The other inclined surface part 36A... First restricting surface 36B... Third 2 Constraining surfaces A... Center axis of insert B... Center of constraining surface in insert circumferential direction D... Center in insert circumferential direction between a pair of constraining surfaces adjacent to each other in insert circumferential direction (center of protrusion in insert circumferential direction)
E... Center of convex curve edge in insert circumferential direction O... Tool center axis O'... Imaginary straight line parallel to tool center axis T... Tool rotation direction θ1... First tilt angle θ2... Second tilt angle

Claims (6)

a tool body centered on the tool center axis;
a disc-shaped cutting insert that is detachably attached to an insert mounting seat that is arranged on the outer periphery of the tip of the tool body,
The cutting insert is
a pair of plate surfaces facing opposite to each other in the axial direction of the insert along which the central axis of the insert extends;
an outer peripheral surface facing outward in a radial direction of the insert orthogonal to the center axis of the insert;
At least one of the pair of plate surfaces facing the tool rotation direction around the tool center axis, and a cutting edge arranged on a ridge connected to the outer peripheral surface,
the outer peripheral surface has a plurality of restraining surfaces arranged in the circumferential direction of the insert around the center axis of the insert;
The insert mounting seat has a pair of seating surfaces that are spaced apart from each other in the circumferential direction of the insert and that are in contact with the restraining surfaces,
The pair of seating surfaces are
an outer seating surface extending toward the tip side in the axial direction of the tool along which the central axis of the tool extends toward the outer side in the radial direction of the tool orthogonal to the central axis of the tool;
an inner seating surface arranged inside the tool radial direction of the outer seating surface and extending toward the rear end side in the tool axial direction as it goes outward in the tool radial direction,
A first inclination angle θ1 at which the outer seating surface is inclined with respect to the tool central axis when the insert mounting seat is viewed from the front in the tool rotation direction is such that the inner seating surface is inclined with respect to the tool central axis. greater than the second tilt angle θ2,
Indexable radius end mill. The cutting edge has a plurality of convex curved edges arranged in the circumferential direction of the insert,
Among the plurality of convex curved blades, the predetermined convex curved blade disposed at the tip in the tool axial direction and the outer end in the tool radial direction has one end in the insert circumferential direction that is located at the cutting edge. positioned closest to the tip side in the axial direction of the tool,
The indexable radius end mill according to claim 1. the outer peripheral surface has a projection disposed between the restraining surfaces adjacent to each other in the insert circumferential direction and protruding outward in the insert radial direction from the restraining surfaces;
a plurality of the protrusions are provided on the outer peripheral surface so as to be alternately arranged in the restraining surface and the insert circumferential direction;
Among the plurality of protrusions, a predetermined protrusion disposed at a tip in the tool axial direction is positioned closest to the tip in the tool axial direction on the outer peripheral surface,
The indexable radius end mill according to claim 1 or 2. The plurality of restraint surfaces are arranged at equal pitches in the circumferential direction of the insert,
The cutting edge has a plurality of convex curved edges arranged at equal pitches in the circumferential direction of the insert,
the center of the restraint surface in the circumferential direction of the insert and the center of the convex curve cutting edge in the circumferential direction of the insert are displaced from each other in the circumferential direction of the insert, and
The center between the pair of restraining surfaces adjacent in the insert circumferential direction and the center of the convex curve cutting edge in the insert circumferential direction are displaced from each other in the insert circumferential direction,
The indexable radius end mill according to any one of claims 1 to 3. The constraining surface is
a plane portion parallel to the center axis of the insert;
an inclined surface portion arranged side by side with the flat surface portion in the axial direction of the insert and extending outward in the radial direction of the insert as it separates from the flat surface portion in the axial direction of the insert;
the outer seating surface contacts one of the planar portion and the inclined surface portion;
the inner seating surface contacts the other of the flat portion and the inclined surface portion;
The indexable radius end mill according to any one of claims 1 to 4. The plurality of constraining surfaces are
a first constraining surface in which the flat portion is arranged in the tool rotation direction and the inclined surface portion is arranged on the side opposite to the tool rotation direction;
a second constraining surface on which the inclined surface portion is arranged in the tool rotation direction and the flat surface portion is arranged on the opposite side to the tool rotation direction;
The first constraining surface and the second constraining surface are alternately arranged in the circumferential direction of the insert,
The indexable radius end mill according to claim 5.

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