JP2022155847A - Boring bar - Google Patents

Abstract

To provide a boring bar which enables simplification of the structure, enables a coolant to reach a cutting blade stably even during a drawing process, and enables improvement of chip discharge performance.SOLUTION: A boring bar includes: a tool body 4 extending along a center axis C in a tool axis direction; and a cutting blade 3 which protrudes from the tool body 4 in a tool width direction orthogonal to the center axis C. The tool body 4 has: a coolant supply passage 47 extending in the tool body 4; a coolant guide surface 48 which is oriented to the upper side in a vertical direction orthogonal to the tool axis direction and the tool width direction; and a coolant guide wall 50 which protrudes upward from the coolant guide surface 48 and extends on the coolant guide surface 48. The coolant supply passage 47 has an opening 47c which is open to the coolant guide wall 50. The coolant guide wall 50 has: a curved part 52 extending in a curved shape when viewed in the vertical direction; and a coolant jet part 52c which is disposed at an end part of the coolant guide wall 50 and faces the cutting blade 3.SELECTED DRAWING: Figure 4

Description

The present invention relates to boring bars.

Conventionally, a boring bar is known which is used for inner diameter machining of a work material. In inner diameter machining, for example, the inner peripheral surface of a blind hole in the work material is cut. A blind hole is, for example, a circular hole with a bottom.
In the conventional boring bar 100 shown in FIG. 11, the opening of the coolant supply path 102 extending inside the tool body 101 opens toward the cutting edge of the cutting insert 103 . The cutting insert 103 shown in FIG. 11 is of a positive type (single-sided type), and the rake angle of the cutting edge is a positive angle.

The boring bar 110 shown in FIG. 12 has the cutting insert 103 of a negative type (double-sided type), and the rake angle of the cutting edge is a negative angle because of the necessity of escaping the flank 105 from the machined surface of the work material. . In such a case, since the opening of the coolant supply path 102 is opened toward the cutting edge, the structure of the coolant supply path 102 tends to be complicated. Specifically, in the example shown in FIG. 12, the coolant supply path 102 extends inside the tool body 101 and has a plurality of holes 102a to 102c communicating with each other and a plug member 106 closing the opening end of the hole 102b. .

In addition, inner diameter processing includes drawing processing, profiling processing, and the like (hereinafter sometimes abbreviated as “drawing processing, etc.”). The drawing process is a process of cutting the inner peripheral surface of a blind hole or the like while retracting the tool body toward the rear end side in the axial direction of the tool.
The conventional boring bar 120 for drawing shown in FIG. However, due to the shape of the tool body 101 for suppressing interference with the work material W, the distance between the opening of the coolant supply passage 102 and the cutting edge of the cutting insert 103 tends to increase, A part of the work material W is located. Therefore, it is difficult to make the coolant reach the cutting edge stably.
Moreover, in machining the inner diameter of a blind hole, there is a problem that chips are pushed into the vicinity of the bottom of the blind hole by the coolant and are difficult to be discharged.

As a boring bar used for drawing, for example, those described in Patent Documents 1 to 3 are known.
The inner diameter machining tool described in Patent Document 1 supplies cutting fluid from a cutting supply portion to a side surface (main flank) continuous to a main cutting edge. The cutting fluid rebounds from the main flank and the flow of cutting fluid expels the chips out of the machined hole.
Also, in the cutting tool described in Patent Document 2, one of the openings of the coolant hole opens toward the flank of the insert.

In the metal cutting tool holder described in Patent Document 3, the tool holder main body has a first fluid passage extending in a first direction, a second fluid passage extending in a second direction, and a cavity. ,including. A member is positioned within the cavity and defines a curved third fluid passageway connecting the first outlet portion of the first fluid passageway and the second inlet portion of the second fluid passageway. have. Fluid exiting the second outlet of the second fluid passageway flows toward the cutting insert.

Japanese Patent No. 5361570 Japanese Patent No. 5501598 Japanese Patent Application Publication No. 2019-501788

In Patent Documents 1 and 2, it is difficult to stably reach the coolant to the cutting edge.
In Patent Document 3, the structure of the coolant supply path provided inside the tool body is complicated, and the manufacturing process is also complicated. Also, it is difficult to apply to a small-diameter boring bar.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a boring bar that can simplify the structure, allow coolant to reach the cutting edge stably even in the case of drawing, etc., and improve the chip discharging performance.

One aspect of the boring bar of the present invention comprises a tool body extending in the tool axial direction along a central axis, and a cutting edge protruding from the tool body in the tool width direction perpendicular to the central axis, wherein the tool The main body includes a coolant supply path extending inside the tool body, a coolant guide surface facing upward in a vertical direction orthogonal to the tool axial direction and the tool width direction, and a coolant guide surface protruding upward from the coolant guide surface. a coolant guide wall extending on the surface, wherein the coolant supply path has an opening that opens toward the coolant guide wall, and the coolant guide wall extends in a curved shape when viewed from the vertical direction. It has a curved portion and a coolant ejection portion disposed at the end of the coolant guide wall and facing the cutting edge.

In the boring bar of the present invention, the coolant flowing out from the opening of the coolant supply passage is guided by the coolant guide wall on the coolant guide surface, is reversed by the curved portion, and is directed from the coolant ejection portion to the cutting edge. supplied by That is, the coolant flowing out from the opening of the coolant supply passage is supplied to the cutting edge indirectly through the coolant guide wall and from a direction (angle) different from the coolant flowing out direction from this opening.

For this reason, unlike the present invention, for example, as shown in FIG. 13, compared to the configuration in which the coolant flows out directly from the opening of the coolant supply passage 102 toward the cutting edge, according to the present invention, the coolant flows from the coolant guide wall. The distance between the coolant outflow part and the cutting edge can be kept small, and part of the work material is not positioned between them. Therefore, even in the case of drawing, etc., the coolant can stably reach the cutting edge.

In addition, since the direction of the coolant is reversed by the curved portion of the coolant guide wall, even when machining the inner diameter of a blind hole in the work material, the coolant pushes chips out of the blind hole and makes it easier to discharge. can be done. For this reason, the chip discharging property is enhanced.

Also, unlike the present invention, the structure of the coolant supply path can be simplified in the present invention, as compared with the coolant supply path 102 having a complicated structure as shown in FIG. 12, for example. Further, according to the present invention, since the internal structure of the tool body is simplified, it can be easily applied to, for example, a small-diameter boring bar.

Also, in the coolant guide wall, the curved portion extends in a curved shape to form a curvilinear coolant flow path. Therefore, according to the present invention, the pressure loss of the coolant flowing through the flow path can be kept small compared to the curved coolant flow path (see coolant supply path 102 in FIG. 12). As a result, the coolant can be jetted toward the cutting edge while the discharge pressure and discharge rate are kept high. Therefore, the coolant can stably reach the cutting edge.

Also, unlike the coolant supply path extending inside the tool body, the coolant guide wall is a coolant flow path that is open to the outside, so the coolant flow has a high degree of freedom. Therefore, part of the coolant flowing along the coolant guide wall is supplied to the vicinity of the cutting edge even through the coolant guide surface. Therefore, coolant can be supplied to the cutting edge more efficiently. Also, for example, an effect of cooling the entire cutting insert can be obtained.

In the above boring bar, the coolant guide wall preferably has a guide groove recessed from a side surface of the coolant guide wall facing the cutting edge and extending along the coolant guide wall.

In this case, the coolant flowing along the coolant guide wall can be more stably guided by the guide groove. That is, the coolant flows in the guide groove along the extending direction of the coolant guide wall and is ejected to the cutting edge. Since the coolant can be held in the guide groove, for example, it is possible to prevent the coolant from splashing upward from the side surface of the coolant guide wall, and the coolant supply efficiency to the cutting edge can be further enhanced. Further, since the guide groove is open toward the cutting edge side on the side surface, part of the coolant flowing through the guide groove is supplied to the vicinity of the cutting edge through the coolant guide surface. Therefore, the coolant can be supplied to the cutting edge more efficiently, and the cooling effect of the cutting edge and the chip discharging performance can be enhanced.

In the above boring bar, it is preferable that the coolant guide surface is in the shape of an inclined surface positioned downward from the coolant guide wall toward the cutting edge.

In this case, of the coolant flowing along the coolant guide wall, part of the coolant that has flowed out onto the coolant guide surface is guided toward the cutting edge by the inclined coolant guide surface. Therefore, coolant can be supplied to the cutting edge more efficiently.

In the above boring bar, the coolant guide wall has a linear portion that extends linearly between at least the curved portion and the opening and guides coolant supplied from the opening to the curved portion. is preferred.

In this case, since the straight portion is provided between the opening of the coolant supply path and the curved portion, the degree of freedom in the shape and layout of the curved portion is increased. That is, for example, it is possible to arrange the bending portion closer to the tip side in the axial direction of the tool, or to bend it at a position where it is less likely to interfere with the cutting insert or the like. As a result, for example, the curved portion can be arranged closer to the cutting edge to increase the coolant supply efficiency. Also, the outflow direction of the coolant from the curved portion toward the cutting edge can be brought closer to the direction toward the rear end side in the axial direction of the tool (that is, the angle of the outflow direction of the coolant can be slanted) to improve chip discharge performance.

In the above boring bar, it is preferable that the cutting edge is a part of a cutting insert that is detachably attached to an insert mounting seat of the tool body, and that the cutting insert has an inverted symmetrical shape.

In this case, the boring bar is an indexable boring bar and the cutting insert is a double-sided negative insert. When using a double-sided cutting insert, as shown in FIG. 12, conventionally, the structure of the coolant supply path tends to be complicated. The road structure can be simplified.

In addition, in the double-sided cutting insert, since the rake angle of the cutting edge is a negative angle, the surface (rake face) of the cutting insert is an inclined surface positioned downward as it approaches the cutting edge. Since the surface of the cutting insert is positioned between the coolant guide wall and the cutting edge, part of the coolant flowing along the coolant guide wall is guided by the inclination of this surface and supplied to the cutting edge. Therefore, the coolant can be efficiently supplied to the cutting edge.

In the above boring bar, it is preferable that the coolant ejection portion is located on the tip side in the tool axial direction with respect to the center axis of the cutting insert.

In this case, the outflow direction of the coolant jetted from the coolant jetting portion toward the cutting edge is more likely to approach the direction toward the rear end side in the axial direction of the tool. For this reason, for example, when the inner diameter of a blind hole is machined, chips can be more efficiently discharged toward the outside of the blind hole.

In the above boring bar, it is preferable that the coolant supply passage has a tapered passage portion in which the cross-sectional area of the passage decreases as it approaches the opening.

In this case, the coolant flows through the tapered flow passage and is supplied to the coolant guide wall through the opening while being increased in flow velocity. In the present invention, since the pressure loss of the coolant flowing along the coolant guide wall is kept small, the coolant flows out toward the cutting edge while maintaining a high flow velocity. Therefore, the coolant can stably reach the cutting edge.

In the above boring bar, the coolant guide wall may be formed integrally with the coolant guide surface.

In this case, the structure of the tool body can be simplified, and the boring bar can be easily manufactured.

In the above boring bar, the coolant guide wall may be detachably attached to the coolant guide surface.

In this case, for example, a plurality of coolant guide walls with different shapes are prepared in advance, and the coolant guide wall can be replaced as appropriate according to the shape of the work material, the shape of the cutting edge, and the cutting conditions. It is possible to respond to various requests for processing.

According to the boring bar of one aspect of the present invention, the structure can be simplified, the coolant can stably reach the cutting edge even in the case of drawing, etc., and the chip discharging performance can be enhanced.

FIG. 1 is a perspective view showing the boring bar of this embodiment. FIG. 2 is a perspective view showing part of the boring bar of this embodiment. FIG. 3 is a perspective view showing part of the boring bar of this embodiment. FIG. 4 is a top view showing part of the boring bar of the present embodiment, and is a diagram for explaining the drawing process and the flow of coolant supplied to the cutting edge. FIG. 5 is a front view showing the boring bar of this embodiment. FIG. 6 is a side view showing the boring bar of this embodiment. 7 is a partial cross-sectional view showing a VII-VII cross section of FIG. 4. FIG. FIG. 8 is a cross-sectional view showing a coolant guide wall of a first modified example of this embodiment. FIG. 9 is a cross-sectional view showing a coolant guide wall of a second modified example of this embodiment. FIG. 10 is a cross-sectional view showing a coolant guide wall of a third modified example of this embodiment. FIG. 11 is a side view showing a conventional boring bar. FIG. 12 is a side view showing a conventional boring bar. FIG. 13 is a top view showing a conventional boring bar, and is a diagram for explaining drawing.

A boring bar 1 according to an embodiment of the present invention will be described with reference to the drawings. The boring bar 1 of this embodiment is a turning tool used for inner diameter machining of a work material, and is detachably attached to a tool post of a machine tool such as a lathe (not shown). This boring bar 1 is particularly suitable for drawing the inner peripheral surface of a bottomed blind hole provided in a work material.

As shown in FIG. 1 , the boring bar 1 includes a cutting insert 2 having a cutting edge 3 , a tool body 4 having an insert mounting seat 5 to which the cutting insert 2 is detachably attached, and a cutting insert 2 mounted on the insert mounting seat 5 . and a clamping member 6 for fixing to. That is, the boring bar 1 has a cutting edge 3 and a tool body 4 . The boring bar 1 of this embodiment is an indexable boring bar.

[Definition of direction]
In this embodiment, the direction in which the central axis C of the tool body 4 extends is called the tool axial direction. In the XYZ orthogonal coordinate system shown in each figure, the tool axis direction corresponds to the Y-axis direction. Of the tool axial directions, the direction (-Y side) from the first end 4a of the tool body 4 to the second end 4b is called the tool rear end side, and the direction from the second end 4b to the first end 4a. The direction (+Y side) is called the tool tip side. Note that the tool axial direction may be rephrased as the front-rear direction. In this case, the tool tip side (+Y side) corresponds to the front side, and the tool rear end side (−Y side) corresponds to the rear side.
A direction orthogonal to the central axis C is called a tool radial direction. In the radial direction of the tool, the direction closer to the center axis C is called the inside in the tool radial direction, and the direction away from the center axis C is called the outside in the tool radial direction.
The direction of rotation around the central axis C is called the tool circumferential direction.

In this embodiment, one of the tool radial directions is called the tool width direction. Therefore, the tool width direction is also a direction perpendicular to the central axis C. As shown in FIG. In each figure, the tool width direction corresponds to the X-axis direction. One side in the tool width direction is the -X side, and the other side is the +X side. Note that the tool width direction may be rephrased as the left-right direction. In this case, one side in the tool width direction (−X side) corresponds to the right side, and the other side in the tool width direction (+X side) corresponds to the left side.
A direction orthogonal to the tool axial direction and the tool width direction is called a vertical direction. The vertical direction is one direction different from the one direction (the tool width direction) in the tool radial direction. In each drawing, the vertical direction corresponds to the Z-axis direction. The upper side in the vertical direction is the +Z side, and the lower side is the -Z side.

As shown in FIGS. 2 and 3, the direction in which the insert central axis A of the cutting insert 2 extends is called 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.

In this embodiment, the upper side, the lower side, the front side, the rear side, the left side, and the right side are names for simply explaining the relative positional relationship of each part, and the actual positional relationship etc. are indicated by these names. An arrangement relationship or the like other than the arrangement relationship may be used.

[Cutting insert]
The cutting insert 2 is made of cemented carbide, PCD (polycrystalline diamond), cBN (cubic boron nitride), cermet, ceramic, or the like, for example. The cutting insert 2 is a hard sintered body having higher hardness than the tool body 4 .

The cutting insert 2 of the present embodiment has a quadrangular plate shape centering on the insert central axis A, and specifically, has a rhombic plate shape. The cutting insert 2 is, for example, a rhombic insert conforming to ISO standards. The cutting insert 2 has a plurality of corners. The cutting insert 2 of this embodiment has a symmetrical shape inside out. The cutting insert 2 is a so-called double-sided negative insert.

The cutting insert 2 is arranged on a front surface 21 and a back surface 22 facing in the axial direction of the insert, an outer peripheral surface 23 connected to the front surface 21 and the back surface 22, and a ridge portion where at least the front surface 21 and the outer peripheral surface 23 are connected. It has a cutting edge 3 and a through hole 24 . The cutting edge 3 is thus part of the cutting insert 2 .

The surface 21 is square-shaped, and in this embodiment is diamond-shaped. The surface 21 faces upwards. The surface 21 has a rake face 21a. The rake face 21 a is arranged on at least a portion of the surface 21 adjacent to the cutting edge 3 .

The back surface 22 has a square shape, and in this embodiment, has a rhombus shape. The back surface 22 faces downward. The back surface 22 has a seating surface. The seating surface contacts the bottom wall 5a of the insert mounting seat 5 (the upper surface of the seat member 51, which will be described later).

The outer peripheral surface 23 faces outward in the radial direction of the insert and extends in the circumferential direction of the insert. The outer peripheral surface 23 has a flank 23a. The flank 23 a is arranged at least in a portion of the outer peripheral surface 23 adjacent to the cutting edge 3 .

The outer peripheral surface 23 has a plurality of planar portions 23b arranged in the circumferential direction of the insert. The flat portion 23b faces outward in the radial direction of the insert and extends in the circumferential direction of the insert. The flat portion 23b has a rectangular shape with a dimension in the circumferential direction of the insert that is larger than the dimension in the axial direction of the insert. In this embodiment, the outer peripheral surface 23 has four plane portions 23b.
As shown in FIG. 4, among the four flat portions 23b, the flat portion 23b facing the tip side (+Y side) in the tool axial direction and the flat portion 23b facing the other side (+X side) in the tool width direction are It contacts with a pair of side walls 5b of the insert mounting seat 5. As shown in FIG.

The cutting edge 3 is arranged at a corner portion of the cutting insert 2 located at least on one side (−X side) in the tool width direction. The cutting edge 3 protrudes from the tool body 4 in the tool width direction. In this embodiment, the cutting edge 3 protrudes from the tool main body 4 to one side in the tool width direction. That is, the cutting edge 3 protrudes outward in the tool radial direction from the tool body 4 .

The cutting edge 3 is arranged at the ridge line where the rake face 21a and the flank face 23a are connected. The cutting edge 3 has a convex V shape that protrudes toward one side in the tool width direction. The cutting edge 3 has a convex curve-shaped corner edge and a pair of linear edge parts connected to both ends of the corner edge and extending linearly. When viewed from the insert axial direction, the angle formed between the pair of straight blades is, for example, 35° to 90°, and is 55° in this embodiment.

The through hole 24 penetrates the cutting insert 2 in the insert axial direction. The through hole 24 extends in the insert axial direction inside the cutting insert 2 and opens to the front surface 21 and the back surface 22 . The through hole 24 has a circular hole shape centered on the central axis A of the insert.

[Tool body]
The tool body 4 is made of metal such as steel. The tool main body 4 is produced, for example, by lamination molding using a 3D printer or the like. As shown in FIG. 1, the tool body 4 has a substantially cylindrical shape and extends along the central axis C in the tool axial direction.
The tool body 4 includes a first tip surface 41, a second tip surface 42, a rear end surface 43, a concave portion 44, a pocket portion 45, an insert mounting seat 5, a clamp member insertion hole (not shown), and a coolant guide surface. 48 , a coolant return surface 49 , a coolant supply passage 47 and a coolant guide wall 50 .

As shown in FIGS. 2 to 6, the first tip surface 41 is arranged at the tip side (+Y side) end of the tool body 4 in the tool axial direction, that is, the first end 4a. The first tip surface 41 faces the tip side in the axial direction of the tool. The first distal end surface 41 has a planar shape extending in a direction perpendicular to the central axis C. As shown in FIG.

The second tip surface 42 is arranged at the first end 4a. The second tip face 42 is arranged adjacent to one side (-X side) of the first tip face 41 in the tool width direction. The second tip end surface 42 is an inclined surface located on the rear end side (-Y side) in the tool axial direction toward one side in the tool width direction. The second tip surface 42 is planar and inclined with respect to the central axis C. As shown in FIG. The second tip face 42 faces one side in the tool width direction and the tip side in the tool axial direction.
As shown in FIG. 4 , the cutting edge 3 of the cutting insert 2 is arranged to protrude to one side in the tool width direction from the second tip surface 42 . Moreover, the cutting edge 3 is arranged so as to protrude from the second tip surface 42 also in the direction orthogonal to the second tip surface 42 .

As shown in FIG. 1, the rear end surface 43 is arranged at the rear end side end portion of the tool body 4 in the axial direction of the tool, that is, the second end portion 4b. The rear end face 43 faces the rear end side in the axial direction of the tool. The rear end surface 43 has a planar shape extending in a direction perpendicular to the central axis C. As shown in FIG.

As shown in FIG. 4, the concave portion 44 is recessed from the surface of the tool body 4 facing one side (−X side) in the tool width direction, that is, the right side surface toward the other side (+X side) in the tool width direction. The recess 44 extends in the tool axis direction. The recessed portion 44 also extends in the tool circumferential direction.
As shown in FIG. 6, the recess 44 has an upper end that opens to the surface of the tool body 4 facing upward, that is, the upper surface. The recessed portion 44 is opened at the lower end of the tool body 4 on the lower surface, ie, the lower surface. The recessed portion 44 is located on the rear end side of the insert mounting seat 5 in the tool axial direction and is arranged adjacent to the insert mounting seat 5 .

The pocket portion 45 is arranged at the first end portion 4 a of the tool body 4 . The pocket portion 45 is recessed downward from the upper surface of the tool body 4 . As shown in FIG. 4 , the pocket portion 45 is arranged side by side with the insert mounting seat 5 . The pocket portion 45 functions as a discharge path (chip pocket) for discharging chips during inner diameter machining.

The insert mounting seat 5 is arranged at a first end portion 4a of both ends of the tool body 4 in the tool axial direction. The cutting insert 2 is detachably attached to the insert mounting seat 5 .
As shown in FIGS. 2 and 3, the insert mounting seat 5 has a plate-like seat member 51 in this embodiment. The seat member 51 constitutes a portion (bottom surface) of the insert mounting seat 5 . In this embodiment, the sheet member 51 has a square plate shape, specifically a rhombic plate shape. A pair of plate surfaces of the sheet member 51 face up and down. The sheet member 51 has a sheet hole (not shown) penetrating the sheet member 51 in the vertical direction.

The insert mounting seat 5 opens to the upper surface, the right side surface, and the concave portion 44 of the tool body 4 at the first end 4 a of the tool body 4 , ie, the tip of the tool. The insert mounting seat 5 is recessed from the upper surface, the right side surface, and the recess 44 of the tool body 4 . The insert mounting seat 5 is a recess that can receive the cutting insert 2 . In the present embodiment, the insert mounting seat 5 has a substantially quadrangular concave shape, specifically, a substantially rhombic concave shape.

As shown in FIGS. 2 and 4, the insert mounting seat 5 includes a bottom wall 5a in contact with the back surface 22 of the cutting insert 2, a side wall 5b in contact with the outer peripheral surface 23 of the cutting insert 2, and a relief portion 5c. have.

A plurality of side walls 5b are provided. In this embodiment, the insert mounting seat 5 has a pair of side walls 5b. Of the pair of side walls 5b, one side wall 5b faces the rear end side (-Y side) in the tool axial direction. contacts the flat portion 23b facing the tip side (+Y side) of the . Of the pair of side walls 5b, the other side wall 5b faces one side (−X side) in the tool width direction, and among the four flat portions 23b of the cutting insert 2, faces the other side (+X side) in the tool width direction. It comes into contact with the facing flat portion 23b. The angle formed between the pair of side walls 5b when viewed from the insert axial direction is, for example, 35° to 90°, and is 55° in this embodiment.

The relief portion 5c is arranged between the pair of side walls 5b. The recessed portion 5c is recessed outwardly in the radial direction of the insert from the pair of side walls 5b. The relief portion 5c is in the form of a groove that opens in a portion (a coolant guide surface 48) of the upper surface of the tool body 4 located at the pocket portion 45 and extends in the axial direction of the insert.

The bottom wall 5 a is configured by one of the pair of plate surfaces of the sheet member 51 (upper surface) facing upward. The bottom wall 5a is in the shape of an inclined surface that is inclined with respect to an imaginary plane (horizontal plane) (not shown) perpendicular to the vertical direction. Specifically, the bottom wall 5a is positioned downward from one side wall 5b of the pair of side walls 5b facing the rear end side (−Y side) in the tool axial direction toward the rear end side in the tool axial direction. do. Further, the bottom wall 5a is positioned downward from the other side wall 5b of the pair of side walls 5b facing one side (-X side) in the tool width direction toward one side in the tool width direction. Also, the bottom wall 5a is positioned downward from the recessed portion 5c toward the cutting edge 3 along the bisector of the pair of side walls 5b when viewed in the axial direction of the insert.

By tilting the bottom wall 5a in this way, the cutting insert 2 placed on the bottom wall 5a has its surface 21 and its rake face 21a tilted in the same manner as the bottom wall 5a. That is, the surface 21 is positioned downward as it goes from one side wall 5b toward the rear end side in the axial direction of the tool. In addition, the surface 21 is located on the lower side as it goes from the other side wall 5b toward one side in the tool width direction. Further, the surface 21 is positioned downward from the recessed portion 5c toward the cutting edge 3 along the bisector of the pair of side walls 5b when viewed in the axial direction of the insert. That is, the rake angle of the cutting edge 3 is a negative angle.
Correspondingly, the cutting edge 3 is provided with a clearance angle. That is, the flank 23a inclines downward from the cutting edge 3 so as to be located on the tip side (+Y side) in the tool axial direction and the other side (+X side) in the tool width direction. This prevents the flank 23a from interfering with the machined surface of the work material during cutting.

Although not shown, the clamp member insertion hole is arranged at the first end portion 4 a and extends inside the tool body 4 . The clamp member insertion hole communicates with the seat hole of the seat member 51 and the through hole 24 of the cutting insert 2 . A portion of the clamp member 6 is arranged in the clamp member insertion hole.

As shown in FIGS. 2 to 6, the coolant guide surface 48 is arranged at the first end 4a and faces upward. A coolant guide surface 48 is located in the pocket portion 45 . The coolant guide surface 48 is arranged adjacent to the insert mounting seat 5 and the cutting insert 2 . Specifically, the coolant guide surface 48 is arranged adjacent to the insert mounting seat 5 and the cutting insert 2 on the tip end side (+Y side) in the tool axial direction and the other side (+X side) in the tool width direction. . In other words, the insert mounting seat 5 and the cutting insert 2 are arranged adjacent to the coolant guide surface 48 on the rear end side (−Y side) in the tool axial direction and one side (−X side) in the tool width direction. be done. In this embodiment, the coolant guide surface 48 is planar. The coolant guide surface 48 is arranged substantially flush with the surface 21 of the cutting insert 2 fixed to the insert mounting seat 5 . Note that the surface 21 of the cutting insert 2 may be arranged below the coolant guide surface 48 .

The coolant guide surface 48, like the bottom wall 5a and the surface 21, has an inclined surface shape that is inclined with respect to an imaginary plane (horizontal plane) (not shown) perpendicular to the vertical direction. Specifically, as shown in FIG. 6, the coolant guide surface 48 is positioned downward toward the rear end side (-Y side) in the axial direction of the tool. Further, as shown in FIG. 5, the coolant guide surface 48 is positioned downward toward one side (-X side) in the tool width direction.

As shown in FIGS. 2-4, the coolant return surface 49 is located at the first end 4a and faces upward. A coolant return surface 49 is located in the pocket portion 45 . The coolant return surface 49 is arranged adjacent to the insert mounting seat 5 and the coolant guide surface 48 . Specifically, the coolant return surface 49 is arranged adjacent to the other side (+X side) of the insert mounting seat 5 in the tool width direction. That is, the coolant return surface 49 is arranged adjacent to the insert mounting seat 5 in the tool width direction. The coolant return surface 49 is arranged adjacent to the coolant guide surface 48 on the other side (-Y side) in the tool axial direction.

The coolant return surface 49 is in the shape of an inclined surface positioned upward toward the rear end side in the axial direction of the tool. That is, the coolant return surface 49 and the coolant guide surface 48 have different inclination directions in a cross section along the tool axis direction. In this embodiment, the coolant return surface 49 is concavely curved.

The coolant return surface 49 extends in the tool width direction. A boundary portion 46 between the coolant return surface 49 and the coolant guide surface 48 also extends in the tool width direction. The boundary portion 46 has a groove shape extending along the tool width direction. In a cross section along the tool axial direction, the boundary portion 46 has a concave V shape recessed downward. The boundary portion 46 is positioned downward along the tool width direction toward the insert mounting seat 5 and cutting insert 2 side, that is, toward one side (−X side) in the tool width direction. The surface 21 of the cutting insert 2 and the cutting edge 3 are positioned on the extension of the boundary portion 46 to one side in the tool width direction.

As shown in FIG. 1 , the coolant supply passage 47 extends inside the tool body 4 . The coolant supply path 47 is provided through the tool body 4 . The coolant supply channel 47 has a supply channel portion 47a and a tapered channel portion 47b.

The supply channel portion 47a extends inside the tool body 4 in the tool axial direction. The supply channel portion 47a has a circular hole shape centering on the central axis C. As shown in FIG. The supply channel portion 47a is a blind hole with a bottom, and has a bottom portion at the end on the tip side in the axial direction of the tool. The supply channel portion 47 a opens to the rear end surface 43 . 47 d of piping connection ports are provided in the rear-end part of the tool axial direction of the supply flow-path part 47a. That is, the coolant supply path 47 has a pipe connection port 47d. A pipe member, a tube member, or the like (not shown) is connected to the pipe connection port 47d. 47 d of piping connection ports are made into the inflow port which receives a coolant in the coolant supply path 47. As shown in FIG.

The tapered channel portion 47b is connected to the tip of the supply channel portion 47a in the tool axial direction, and extends substantially along the tool axial direction at a slightly inclined angle with respect to the central axis C. As shown in FIG. As shown in FIGS. 5 and 6, the tapered channel portion 47b is connected to the upper portion of the tip portion, that is, the bottom portion of the supply channel portion 47a in the axial direction of the tool. 4 and 5, the tapered channel portion 47b is connected to the other side (+X side) in the tool width direction of the bottom portion of the supply channel portion 47a. The tapered channel portion 47b extends upward from the connection portion with the supply channel portion 47a toward the tip side in the axial direction of the tool and toward the other side in the tool width direction.

As shown in FIGS. 2 and 3, an opening 47c is provided at the tip of the tapered flow path 47b in the tool axial direction. That is, the coolant supply path 47 has an opening 47c. The opening 47c serves as an outlet through which the coolant flowing through the coolant supply path 47 flows. The opening 47 c is arranged in the pocket portion 45 . The opening 47c opens to the upper surface of the tool body 4. As shown in FIG. Specifically, the opening 47 c opens to the coolant return surface 49 . The shape of the opening 47c leading to the coolant return surface 49 is rectangular or elliptical extending along the inclination of the coolant return surface 49 in the tool axial direction.

The tapered flow path portion 47b has a flow path cross-sectional area that decreases as it approaches the opening 47c. That is, the tapered flow path portion 47b has a tapered hole shape that gradually decreases in diameter toward the distal end side in the axial direction of the tool.
In the present embodiment, as shown in FIG. 5, the shape of each channel cross-section of the tapered channel portion 47b and the opening portion 47c is square.

As shown in FIGS. 2-4, a coolant guide wall 50 is arranged at the first end 4a. A coolant guide wall 50 is located in the pocket portion 45 . The coolant guide wall 50 is rib-shaped and protrudes upward from a portion of the upper surface of the tool body 4 located at the pocket portion 45 and extends along the surface direction of the upper surface portion. Specifically, the coolant guide wall 50 protrudes upward from at least the coolant guide surface 48 and extends on the coolant guide surface 48 . In this embodiment, the coolant guide wall 50 has a portion that protrudes upward from the coolant guide surface 48 and extends along the coolant guide surface 48 and a portion that protrudes upward from the coolant return surface 49 and extends along the coolant return surface 49 . ,including. That is, the coolant guide wall 50 extends over the coolant guide surface 48 and the coolant return surface 49 .
In this embodiment, the coolant guide wall 50 is formed integrally with the coolant guide surface 48 and the coolant return surface 49 . That is, the coolant guide wall 50 is formed integrally with the tool body 4 .

The coolant guide wall 50 is arranged adjacent to the other side (+X side) of the opening 47c in the tool width direction. Although not shown, an imaginary extension line extending the common axis (central axis) of the tapered flow path portion 47b and the opening portion 47c toward the tip side in the axial direction of the tool intersects the coolant guide wall 50 . That is, the opening 47 c opens toward the coolant guide wall 50 . Therefore, the coolant flowing out from the opening 47 c flows on the coolant guide surface 48 while being guided by the coolant guide wall 50 .

The coolant guide wall 50 is positioned on the other side (+X side) in the tool width direction and on the tip side (+Y side) in the tool axial direction with respect to the insert mounting seat 5 and the cutting insert 2 . Since the coolant guide surface 48 has the above-described inclined surface shape, the coolant guide surface 48 is positioned downward as it approaches the cutting edge 3 from the coolant guide wall 50 .

The coolant guide wall 50 has a curved portion 52, a straight portion 53, a guide groove 55, and a coolant ejection portion 52c.
The curved portion 52 is arranged at the tip end of the coolant guide wall 50 in the axial direction of the tool. The curved portion 52 is located on the tip side (+Y side) in the tool axial direction with respect to the insert mounting seat 5 and the cutting insert 2 . As shown in FIG. 4, the curved portion 52 extends in a curved shape when viewed from the vertical direction. In the top view shown in FIG. 4, the curved portion 52 extends in a curved shape that is convex toward the tip side in the axial direction of the tool, specifically, in a convex circular arc shape.
The coolant guide wall 50 reverses the direction of the coolant supplied from the opening 47 c by the curved portion 52 to flow the coolant toward the cutting edge 3 .

The straight portion 53 is arranged at a portion of the coolant guide wall 50 other than the tip portion in the tool axial direction. The straight portion 53 is positioned on the other side (+X side) in the tool width direction with respect to the insert mounting seat 5 and the cutting insert 2 . The straight portion 53 is connected to the curved portion 52 and extends from the curved portion 52 toward the rear end side in the axial direction of the tool. Specifically, the linear portion 53 is connected to the end portion 52a on the other side in the tool width direction of the curved portion 52 and the end portion 52a on the rear end side in the tool axial direction, and extends along the tool axial direction. The straight portion 53 is located between at least the curved portion 52 and the opening 47 c and extends linearly, and guides the coolant supplied from the opening 47 c to the curved portion 52 .

As shown in FIGS. 2 and 7 , the coolant guide wall 50 has a guide groove 55 recessed from a side surface 54 of the coolant guide wall 50 facing the cutting edge 3 side and extending along the coolant guide wall 50 . That is, the guide groove 55 extends over the straight portion 53 and the curved portion 52 along the extending direction of the coolant guide wall 50 . An imaginary extension line obtained by extending the common axis (central axis) of the tapered flow path portion 47 b and the opening portion 47 c toward the distal end side in the tool axial direction intersects the guide groove 55 . That is, the opening 47 c opens toward the guide groove 55 . Therefore, the coolant flowing out from the opening 47 c flows while being guided by the guide groove 55 .

As shown in FIG. 6, the guide groove 55 faces the cutting edge 3 of the coolant guide wall 50 on one side (−X side) of the curved portion 52 in the tool width direction. facing) end face 52b. A portion of the guide groove 55 that opens to the end surface 52b serves as a coolant ejection portion 52c. That is, the coolant guide wall 50 has a coolant ejection portion 52c. The coolant ejection portion 52c is arranged at the end portion of the coolant guide wall 50 and faces the cutting edge 3 (facing the cutting edge 3 side). That is, the coolant ejection portion 52c is positioned at the end portion on the cutting edge 3 side along the extending direction of the coolant guide wall 50 .

As shown in FIG. 4 , the coolant ejection portion 52c is located on the tip side (+Y side) in the tool axial direction with respect to the center axis A of the cutting insert 2 . Also, as shown in FIG. 4, when viewed from above and below, an imaginary straight line (corresponding to F3) connecting the coolant ejection portion 52c and the cutting edge 3 is located at the tip of the cutting insert 2 in the tool axial direction relative to the center axis A of the cutting insert 2. pass by the side

As shown in FIG. 7, in the present embodiment, the guide groove 55 is in the shape of an angular groove recessed sideways. Moreover, the cross-sectional shape of the guide groove 55 is substantially constant along the extending direction of the coolant guide wall 50 .
The guide groove 55 has an upper wall 55a, a lower wall 55b, and a lateral wall 55c.

The upper wall 55a is arranged at the upper end of the guide groove 55 and faces downward. The upper wall 55 a has a planar shape extending substantially parallel to the coolant guide surface 48 .
The lower wall 55b is arranged at the lower end of the guide groove 55 and faces upward. The bottom wall 55b is planar. In this embodiment, the lower wall 55b is arranged flush with the coolant guide surface 48 without a step.
The lateral wall 55c is connected at its upper end to the upper wall 55a and at its lower end to the lower wall 55b. The lateral wall 55c faces the cutting edge 3 (not shown) (right side in FIG. 7). The lateral wall 55c has a planar shape extending in a direction substantially perpendicular to the coolant guide surface 48 .

[Clamp member]
2, the clamp member 6 is inserted into the clamp member insertion hole (not shown) of the tool body 4, the seat hole (not shown) of the sheet member 51, and the through hole 24 of the cutting insert 2. As shown in FIG. The clamp member 6 is, for example, a clamp screw, a lever lock mechanism, or the like. The clamp member 6 fixes the cutting insert 2 to the insert mounting seat 5 while pressing the pair of flat portions 23 b of the cutting insert 2 against the pair of side walls 5 b of the insert mounting seat 5 .

[Effects of this embodiment]
In the boring bar 1 of the present embodiment described above, the coolant flowing out from the opening 47c of the coolant supply passage 47 is guided by the coolant guide wall 50 on the coolant guide surface 48 and reversed by the curved portion 52. Then, the coolant is supplied toward the cutting edge 3 from the coolant ejection portion 52c. That is, the coolant flowing out from the opening 47c of the coolant supply passage 47 is indirectly directed to the cutting edge 3 through the coolant guide wall 50 and from a direction (angle) different from the coolant flowing out direction from the opening 47c. supplied.
Specifically, in the present embodiment, as shown in FIG. 4, the coolant flowing out from the opening 47c flows linearly in the F1 direction indicated by the solid arrow along the direction in which the straight portion 53 extends, and the direction in which the curved portion 52 extends. , and flows linearly in the F3 direction indicated by the solid arrow toward the cutting edge 3 from the coolant ejection portion 52c.

For this reason, unlike the present embodiment, for example, as shown in FIG. 13, compared to the configuration in which the coolant flows directly from the opening of the coolant supply path 102 toward the cutting edge, according to the present embodiment, the coolant guide The distance between the coolant outflow part (coolant ejection part 52c) from the wall 50 and the cutting edge 3 can be kept small, and part of the work material W is not positioned between them. Therefore, the coolant can stably reach the cutting edge 3 even in the case of drawing machining or the like.

In addition, since the direction of the coolant is reversed by the curved portion 52 of the coolant guide wall 50, even when the inner diameter of a blind hole in the workpiece W is machined, the coolant pushes chips out of the blind hole and discharges them. can be made easier. For this reason, the chip discharging property is enhanced.

Also, unlike the present embodiment, the structure of the coolant supply path 47 can be simplified in the present embodiment, as compared with the coolant supply path 102 having a complicated structure as shown in FIG. 12, for example. In addition, in this embodiment, since the internal structure of the tool body 4 is simplified, it can be easily applied to, for example, a small-diameter boring bar 1 as well.

In the coolant guide wall 50, the curved portion 52 extends in a curved shape and forms a curvilinear coolant flow path. Therefore, according to the present embodiment, the pressure loss of the coolant flowing through the flow path can be kept small compared to the curved coolant flow path (see coolant supply path 102 in FIG. 12). As a result, the coolant can be jetted toward the cutting edge 3 while the discharge pressure and discharge rate are kept high. Therefore, the coolant can reach the cutting edge 3 more stably.

Further, unlike the coolant supply path 47 extending inside the tool body 4, the coolant guide wall 50 is a coolant flow path that is open to the outside, so the coolant flow has a high degree of freedom. Therefore, part of the coolant flowing along the coolant guide wall 50 (for example, about 10%) passes over the coolant guide surface 48 and the surface 21, as indicated by the dashed arrow F4 in FIG. supplied to Therefore, coolant can be supplied to the cutting edge 3 more efficiently. Moreover, the effect of cooling the cutting insert 2 as a whole can be obtained.

Further, in this embodiment, the coolant guide wall 50 has a guide groove 55 recessed from a side surface 54 of the coolant guide wall 50 facing the cutting edge 3 side and extending along the coolant guide wall 50 .
In this case, the coolant flowing along the coolant guide wall 50 can be guided more stably by the guide grooves 55 . That is, the coolant flows in the guide groove 55 along the extending direction of the coolant guide wall 50 and is jetted to the cutting edge 3 . Since the coolant can be held in the guide groove 55, it is possible to prevent the coolant from splashing upward from the side surface 54 of the coolant guide wall 50, and the efficiency of supplying the coolant to the cutting edge 3 is further enhanced. In addition, since the guide groove 55 is open toward the cutting edge 3 side on the side surface 54 , part of the coolant flowing through the guide groove 55 passes through the coolant guide surface 48 and the surface 21 and near the cutting edge 3 . supplied to Therefore, the coolant can be supplied to the cutting edge 3 more efficiently, and the cooling effect of the cutting edge 3 and the chip discharging performance can be enhanced.

Further, in the present embodiment, the coolant guide surface 48 is in the shape of an inclined surface that is positioned downward as it approaches the cutting edge 3 from the coolant guide wall 50 .
In this case, of the coolant flowing along the coolant guide wall 50 , part of the coolant that has flowed onto the coolant guide surface 48 is guided toward the cutting edge 3 by the inclined coolant guide surface 48 . Therefore, the coolant can be supplied to the cutting edge 3 more efficiently.

Further, in this embodiment, the coolant guide wall 50 has a straight portion 53 .
In this case, the linear portion 53 is provided between the opening 47c of the coolant supply path 47 and the curved portion 52, so that the shape and layout of the curved portion 52 are more flexible. That is, for example, the bending portion 52 can be arranged closer to the tip side in the axial direction of the tool, or can be bent at a position where it is less likely to interfere with the cutting insert 2 . As a result, for example, the curved portion 52 can be arranged closer to the cutting edge 3 to improve the coolant supply efficiency. In addition, the outflow direction F3 of the coolant from the curved portion 52 toward the cutting edge 3 is brought closer to the direction toward the rear end side in the axial direction of the tool (that is, the angle of the coolant outflow direction F3 is slanted) to improve the chip discharging performance. be able to.

Further, in this embodiment, the cutting edge 3 is a part of the cutting insert 2 that is detachably attached to the insert mounting seat 5 of the tool body 4, and the cutting insert 2 has a symmetrical shape.
In this case, the boring bar 1 is an indexable boring bar, and the cutting insert 2 is a double-sided negative insert. When using a double-sided cutting insert 2, as shown in FIG. However, the structure of the coolant supply path 47 can be simplified.

In addition, in the double-sided cutting insert 2, the rake angle of the cutting edge 3 is a negative angle. be done. Since the surface 21 of the cutting insert 2 is positioned between the coolant guide wall 50 and the cutting edge 3 , part of the coolant flowing along the coolant guide wall 50 is guided by the inclination of the surface 21 and cuts into the cutting edge 3 . supplied to Therefore, coolant can be efficiently supplied to the cutting edge 3 .

Further, in the present embodiment, the coolant ejection portion 52c of the coolant guide wall 50 is located on the tip side in the tool axial direction with respect to the insert center axis A of the cutting insert 2 .
In this case, the outflow direction F3 of the coolant ejected from the coolant ejection portion 52c toward the cutting edge 3 can be brought closer to the rear end side in the axial direction of the tool. For this reason, for example, when the inner diameter of a blind hole is machined, chips can be more efficiently discharged toward the outside of the blind hole.

Further, in this embodiment, the coolant supply path 47 has a tapered flow path portion 47b in which the cross-sectional area of the flow path decreases as it approaches the opening 47c.
In this case, the coolant flows through the tapered flow path portion 47b so as to increase the flow velocity, and is supplied to the coolant guide wall 50 from the opening portion 47c. In this embodiment, since the pressure loss of the coolant flowing along the coolant guide wall 50 is kept small, the coolant flows out toward the cutting edge 3 while maintaining a high flow velocity. Therefore, the coolant can stably reach the cutting edge 3 .

Also, in this embodiment, the coolant guide wall 50 is formed integrally with the coolant guide surface 48 and the coolant return surface 49 .
In this case, the structure of the tool body 4 can be simplified, and the boring bar 1 can be manufactured easily.

Further, in this embodiment, as shown in FIG. Pass through the tip side in the axial direction.
In this case, it is easier to discharge chips to the outside of the blind hole during inner diameter machining.

In addition, in this embodiment, a coolant return surface 49 having a different inclination direction from the coolant guide surface 48 is provided, and a boundary portion 46 is arranged between the coolant guide surface 48 and the coolant return surface 49 .
In this case, the coolant flowing on the coolant guide surface 48 toward the rear end side in the axial direction of the tool is blocked by the coolant return surface 49, and the blocked coolant flows along the boundary portion 46 onto the surface 21 of the cutting insert 2. flowed into Therefore, the coolant can be supplied to the cutting edge 3 more efficiently.

[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 modified example, 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, the guide groove 55 of the coolant guide wall 50 has an angular groove shape recessed sideways, but the present invention is not limited to this.
As shown in FIG. 8 as a first modified example, the guide groove 55 may be in the shape of a round groove recessed sideways. Further, as shown as a second modification in FIG. 9 and a third modification in FIG. 10, the guide groove 55 may be a groove with a V-shaped cross section that is recessed sideways.

Further, in the above-described embodiment, an example in which the cross-sectional shape of the guide groove 55 is substantially constant along the extending direction of the coolant guide wall 50 was given, but the present invention is not limited to this. For example, the channel cross-sectional area of the guide groove 55 may be made smaller as it approaches the coolant ejection portion 52c along the extending direction of the coolant guide wall 50 . In this case, the coolant flows through the guide grooves 55 , so that the flow velocity is further increased, and the coolant is jetted toward the cutting edge 3 . Thereby, the supply efficiency of the coolant to the cutting edge 3 is enhanced.

In the above-described embodiment, an example in which the coolant guide wall 50 is formed integrally with the coolant guide surface 48 and the coolant return surface 49 was given, but the present invention is not limited to this. That is, the coolant guide wall 50 may be detachably attached to the coolant guide surface 48 and the coolant return surface 49 by, for example, screwing. In this case, for example, a plurality of coolant guide walls 50 having different shapes are prepared in advance, and the coolant guide walls 50 are appropriately replaced according to the shape of the workpiece W, the shape of the cutting edge 3, the cutting conditions, and the like. It is possible to respond to various requests for inner diameter machining by such as.

In the above-described embodiment, an example in which the coolant guide surface 48 is flat was given, but the shape is not limited to this, and may be, for example, a concave curved surface. Moreover, although the example in which the coolant return surface 49 is concavely curved has been given, it is not limited to this, and may be planar, for example.
Further, although an example in which the tapered flow path portion 47b of the coolant supply path 47 extends linearly has been given, it is not limited to this and may extend in a curved line.

In the above-described embodiment, an example in which the cutting insert 2 has a rectangular plate shape was given, but the shape is not limited to this. The cutting insert 2 may have, for example, a polygonal plate shape other than a rectangular plate shape, a disk shape, or the like. The cutting insert 2 may also be a so-called single-sided positive insert.

Although not shown, the tool body 4 may be a head-replaceable tool body having a shank portion extending in the tool axial direction and a head member detachably fixed to the tool tip portion of the shank portion. In this case, the pocket portion 45, the insert mounting seat 5, the cutting insert 2, the clamp member 6, the opening 47c, the coolant guide surface 48, the coolant return surface 49 and the coolant guide wall 50 are provided in the head member.

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 boring bar of the present invention, the structure can be simplified, the coolant can stably reach the cutting edge even in the case of drawing or the like, and the chip discharging performance can be enhanced. Therefore, it has industrial applicability.

DESCRIPTION OF SYMBOLS 1... Boring bar 2... Cutting insert 3... Cutting edge 4... Tool body 5... Insert mounting seat 47... Coolant supply path 47b... Tapered flow path part 47c... Opening part 48... Coolant guide surface 50... Coolant guide wall 52... Curved part 52c... Coolant ejection part 53... Straight part 54... Side surface 55... Guide groove A... Center axis of insert C... Center axis

Claims (9)

a tool body extending in the tool axial direction along the central axis;
a cutting edge protruding from the tool body in a tool width direction orthogonal to the central axis,
The tool body is
a coolant supply path extending inside the tool body;
a coolant guide surface facing upward in a vertical direction orthogonal to the tool axial direction and the tool width direction;
a coolant guide wall projecting upward from the coolant guide surface and extending on the coolant guide surface;
The coolant supply path has an opening that opens toward the coolant guide wall,
The coolant guide wall is
a curved portion extending in a curved shape when viewed in the vertical direction;
a coolant ejection portion disposed at the end of the coolant guide wall and facing the cutting edge;
bowling bar. The coolant guide wall has a guide groove recessed from a side surface of the coolant guide wall facing the cutting edge and extending along the coolant guide wall,
A boring bar according to claim 1. The coolant guide surface is in the shape of an inclined surface positioned downward as it approaches the cutting edge from the coolant guide wall.
A boring bar according to claim 1 or 2. The coolant guide wall has a straight portion that extends linearly between at least the curved portion and the opening, and guides coolant supplied from the opening to the curved portion.
A boring bar according to any one of claims 1 to 3. The cutting edge is a part of a cutting insert that is detachably attached to an insert mounting seat of the tool body,
The cutting insert has an inverted symmetrical shape,
A boring bar according to any one of claims 1 to 4. The coolant ejection part is located on the tip side in the tool axial direction with respect to the center axis of the cutting insert,
A boring bar according to claim 5. The coolant supply path has a tapered flow path portion with a flow path cross-sectional area that decreases as it approaches the opening,
A boring bar according to any one of claims 1 to 6. The coolant guide wall is integrally formed with the coolant guide surface,
A boring bar according to any one of claims 1 to 7. The coolant guide wall is detachably attached to the coolant guide surface,
A boring bar according to any one of claims 1 to 7.

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