JP2020049577A - Chip suction type cutting tool - Google Patents

Abstract

To ensure high rigidity of a tool body and perform highly accurate processing by preventing occurrence such as chattering vibration even in a case where an amount of projection is large.SOLUTION: At the leading end of a shaft-like tool body 1, a leading-end notch portion 4 is formed, which has a bottom surface 4a along a longitudinal direction of the tool body 1 and a wall surface 4b directed toward the leading end of the tool body 1. A cutting blade 6a is provided on the leading-end outer peripheral portion of the bottom surface 4a. In at least one of the bottom surface 4a and the wall surface 4b, a chip suction port 8 is open, which is formed so as to obliquely extend from a first end 4e1 side of the intersecting ridge line 4e of the bottom surface 4a and the wall surface 4b of the leading-end notch portion 4 toward the second end 4e2 of the intersecting ridge line 4e opposite the first end 4e1, and in a direction of the rear end of the tool body 1 as viewed from a direction opposite the bottom surface 4a. On the second end 4e2 side of the tool body 1, a chip discharge passage 9 is formed, which extends to the rear end of the tool body 1 in communication with the chip suction port 8 and connected to chip suction means.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a chip suction type cutting tool in which a chip suction passage connected to a chip suction means is formed in a shaft-shaped tool body.

  As such a chip suction type cutting tool, for example, in Patent Literature 1, in a turning tool provided with a cutting insert having a cutting edge at a tip of a tool main body, a casing movable along the tool main body is provided, It is described that this casing can take a position covering the rake face of the cutting blade and a position deviating from the rake face.

JP-A-10-277811

  However, in the chip suction type cutting tool described in Patent Document 1, the chip discharge path (through hole) to which the suction means is connected is coaxial with the center axis of the tip end of the cylindrical tool body to which the cutting insert is attached. Since the periphery of the center axis of the tool main body is cut off by the chip discharge path, it is difficult to secure the rigidity of the tool main body. For this reason, when the amount of protrusion of the tool main body is large or the like, chatter vibration or the like is generated, and machining accuracy may be impaired.

  The present invention has been made under such a background, and it is possible to secure high rigidity in a tool main body, to prevent occurrence of chatter vibration and the like even when a protrusion amount is large, and to perform high-precision machining. It is an object of the present invention to provide a chip suction type cutting tool that can perform cutting.

  In order to solve the above-mentioned problems and achieve such an object, the present invention provides a tool body formed in an axial shape, having a bottom surface extending in the longitudinal direction of the tool body, and intersecting the bottom surface. A tip notch having a wall extending in the direction and facing the tip side of the tool body is formed, and the outer periphery of the tip at the bottom of the tip notch has a rake face facing the same direction as the bottom. A cutting edge is provided, and at least one of the bottom surface and the wall surface of the tip notch is provided on the rear end side of the tool body as viewed from a direction facing the bottom surface of the tip notch. It is formed so as to extend diagonally from the first end side of the intersection ridge portion between the bottom surface and the wall surface of the portion toward the second end side of the intersection ridge portion opposite to the first end portion. The chip suction port is open, and the second The part side, extending to the rear end side of the tool body communicates with the chip suction port, wherein the chip discharge path connected to the chip suction means is formed.

  In the chip suction type cutting tool configured as described above, the chip discharge path of the tool main body is formed on the second end side of the tool main body, and the tip notch provided with the cutting edge is defined as When viewed from the direction opposite to the bottom surface of the tip notch, toward the rear end side of the tool body, the first end portion extends from the first end side of the intersection ridge line between the bottom surface and the wall surface of the tip notch portion. Communicate with each other via a chip suction port which extends obliquely toward the second end side of the intersection ridge line portion opposite to the above. For this reason, a sufficient thickness can be left around the center axis of the tool body in a direction opposite to the rake face where the cutting load acts on the cutting edge, and high rigidity can be obtained against such a cutting load. It is possible to secure.

  Therefore, according to the chip suction type cutting tool having the above configuration, even if the amount of protrusion is large, it is possible to prevent chattering vibration or the like from being generated in the tool body, and it is possible to obtain high machining accuracy. For this reason, stable cutting can be performed especially in a boring bar for inner diameter machining in which the protrusion amount is determined by the work material. In addition, when the present invention is applied to such a boring bar for internal diameter machining, in the present invention, the chips are discharged through the chip discharge path in the tool body, so that the chips are separated from the outer periphery of the tool body and the work material. Can be prevented from rubbing against the inner periphery of the machining hole, so the outer diameter of the tool body can be increased to near the inner diameter of the machining hole, and the rigidity of the tool body is further secured and more stable Cutting can be performed.

  Here, an outer peripheral notch formed by cutting the tool main body at the second end in the longitudinal direction is formed on the second end side of the tool main body, and an outer peripheral cover covering the outer peripheral notch is formed. By detachably attaching the chip to the tool body, if the chip discharge path is formed, chips are sucked through the chip suction port formed obliquely as described above and discharged through the chip discharge path. However, only the outer peripheral cover is damaged by scraping of the chips. Then, when the outer peripheral cover is worn due to scraping of the chips, the outer peripheral cover can be replaced, so that it is efficient and economical.

  Further, by providing the cutting edge on the first end side of the bottom surface of the tip notch, chips generated by the cutting edge can be removed from the first end side of the tool main body by the above-described method. Through the chip suction port formed obliquely as described above, the chip can be smoothly discharged to the chip discharge path formed on the second end side and sucked and discharged.

  In particular, when the cutting edge is provided on the first end side of the bottom surface of the tip notch as described above, the first end side of the tool main body is provided in the tool main body. By forming a coolant hole extending in the longitudinal direction of the tool body and opening it in the wall surface of the notch at the end, the coolant is also used to secure the rigidity of the tool body in a direction in which a cutting load acts on the cutting edge, and the chip is formed by the coolant. The life of the cutting blade can be prolonged by cutting or cooling.

  On the other hand, a tip cover for covering the tip notch at a distance from the cutting blade may be detachably attached to the tip of the tool body. Chips can be guided into the chip discharge path from the chip suction port without being scattered by sucking chips into the front cover from the space between the front cover and the cutting blade.

  Further, in the case where the tip cover is attached in this manner, by attaching the tip cover so as to be rotatable around a rotation axis intersecting the bottom surface on the opposite side of the bottom surface of the tip notch from the above-mentioned cutting edge, the cutting edge is also used as a tool. Even when the cutting insert is detachably attached to the main body, the cutting insert can be replaced without completely removing the tip cover from the tool main body.

  When the tip cover is attached to the tool main body so as to be rotatable around the rotation axis opposite to the cutting blade, the wall of the tip notch faces the bottom surface of the tip notch. By forming a recess on the side opposite to the cutting edge when viewed from the direction, it becomes possible to avoid interference between the tip cover and the wall surface of the tip notch by the recess, and the tip insert can be smoothly rotated by rotating the tip cover. Can be exchanged.

  As described above, according to the present invention, even if a chip discharge path extending in the longitudinal direction is formed in the axial tool body, high rigidity is secured in the tool body in the direction in which the cutting load acts on the cutting blade. Even if the amount of protrusion is large, it is possible to prevent chattering vibration or the like from being generated in the tool main body, and to obtain high machining accuracy.

It is a perspective view showing one embodiment of the present invention. It is a top view of the embodiment shown in FIG. It is a right view of the embodiment shown in FIG. It is a front view of the embodiment shown in FIG. FIG. 2 is a rear view of the embodiment shown in FIG. 1. FIG. 2 is an exploded perspective view of the embodiment shown in FIG. FIG. 2 is a plan view of the tool main body according to the embodiment shown in FIG. It is a right view of the tool main body shown in FIG. It is a left view of the tool main body shown in FIG. It is a front view of the tool main body shown in FIG.

  1 to 10 show one embodiment of the present invention, and show a case where the present invention is applied to a boring bar. In the present embodiment, the tool body 1 is formed of a metal material such as a steel material into a substantially multi-stage cylindrical shaft centered on the axis O, and has a rear end portion (an upper right portion in FIGS. 1 and 6; FIG. 2). , FIG. 3, and FIGS. 7 to 9) are shank portions 2 whose outer shapes remain substantially cylindrical.

  The upper edge and the lower edge (upper and lower edges in FIGS. 3 to 5 and FIGS. 8 to 10) of the shank portion 2 are parallel to each other and also to the axis O in the longitudinal direction of the tool body 1 (the axis O). (A direction) is formed. The tool body 1 is supported by the machine tool, with the shank portion 2 being clamped by bringing the set bolt of the adapter of the machine tool into contact with these notched surfaces 2a.

  The tip of the tool body 1 (the lower left portion in FIGS. 1 and 6; the left portion in FIGS. 2, 3, and 7 to 9) has an outer shape slightly larger in diameter than the shank portion 2. The blade portion 3 is formed in a substantially cylindrical shape with the axis O as a center. The blade portion 3 has a bottom surface 4a extending in the longitudinal direction of the tool body 1 from the distal end surface of the blade portion 3, and extends in a direction intersecting the bottom surface 4a so as to face the distal end side of the tool body 1 and A front end notch 4 having a wall surface 4b reaching the outer peripheral surface on the edge side is formed.

  The bottom surface 4a of the notch 4 is inclined toward the lower edge of the blade 3 toward the rear end of the tool body 1 as shown in FIGS. On the other hand, the wall surface 4 b of the notch 4 is perpendicular to the axis O. The intersection ridge 4e between the bottom surface 4a and the wall surface 4b is formed in a concave curved surface and is smoothly connected to the bottom surface 4a and the wall surface 4b.

  Further, a first end (a lower end in FIG. 7; a right end in FIG. 10) of the intersecting ridge line portion 4e when viewed from a direction facing the bottom surface 4a is provided on a bottom surface 4a of the tip notch portion 4. An insert mounting seat 5 is formed at the end corner of 4e1 so as to be recessed one step from the bottom surface 4a. The insert mounting seat 5 has a polygonal (for example, rhombus) bottom surface 5a parallel to the bottom surface 4a, a wall surface 5b facing the tip side of the tool body 1 extending from the bottom surface 5a to the bottom surface 4a of the tip notch 4, and a tool body. 1 has a wall surface 5c facing the outer peripheral side, and a screw hole 5d is formed in the bottom surface 5a. Note that the tip end surface of the blade portion 3 is inclined so as to approach the tip end side as it approaches the first end 4e1 side.

  The cutting blade 6 a in the chip suction type cutting tool of the present embodiment is formed on a cutting insert 6 that is detachably attached to the insert mounting seat 5. That is, the chip suction type cutting tool according to the present embodiment is a boring bar having a replaceable cutting edge. The cutting insert 6 is made of a material such as cemented carbide having a higher hardness than the tool body 1 and has a polygonal surface (for example, slightly larger than the bottom surface 5a) in a shape that matches the shape of the bottom surface 5a of the insert mounting seat 5. , Rhombic surface).

  Such a cutting insert 6 has one polygonal surface as a seating surface and is in close contact with the bottom surface 5a, and the side surface facing the rear end side of the tool body 1 corresponds to the wall surface 5b, and the side surface facing the inner peripheral side corresponds to the wall surface 5c. Then, the clamp screw 7 is inserted into the screw hole 5d in the same direction as the bottom surface 4a of the distal end notch 4 and inserted from the other polygonal surface which is the rake surface 6b. Removably attached. The cutting blade 6a is formed at a corner of the rake face 6b on the outer peripheral side of the distal end of the tool main body 1, and slightly protrudes from the distal end surface and the outer peripheral surface of the blade section 3 with the cutting insert 6 attached. I have.

  In the tool body 1, a coolant hole 1 a extending parallel to the axis O from the rear end face of the shank portion 2 to the tip notch portion 4 of the blade portion 3 on the first end 4 e 1 side of the tool body 1. Are formed. The coolant hole 1a is opened at the rear end side of the insert mounting seat 5 on the wall surface 4b side of the intersection ridge 4e of the bottom surface 4a and the wall surface 4b of the front notch 4. The cutting blade 6a is disposed so as to be located on an extension of the coolant hole 1a toward the distal end of the tool body 1.

  Further, from the bottom surface 4a to the wall surface 4b of the front notch 4, the first end 4e1 of the intersection ridge 4e between the bottom surface 4a and the wall surface 4b and the intersection opposite to the first end 4e1. A chip suction port for suctioning chips generated by the cutting blade 6a is provided at a central portion between the second end portion (the upper end portion in FIG. 7 and the left end portion in FIG. 10) 4e2 of the ridge portion 4e. 8 is open. The chip suction port 8 extends so as to gradually increase in width from the rear end side of the tool body 1 to the rear end side on the bottom surface 4 a of the front end notch portion 4 more slightly than the front end surface of the blade portion 3. In 4b, the blade portion 3 extends slightly to the inner peripheral side of the tool main body 1 from the upper edge portion, and is opened in a substantially semi-elliptical shape.

  6 and 7, when viewed from the direction opposite to the bottom surface 4a of the notch 4, the rear end of the tool body 1 extends from the opening from the bottom surface 4a to the wall surface 4b. It is formed so as to extend diagonally from the first end 4e1 side of the intersection ridge 4e toward the second end 4e2 side toward the side. Further, in the shank portion 2 of the tool body 1, a chip discharge path 9 communicating with the chip suction port 8 is formed on the second end 4e2 side so as to avoid the axis O. The chip suction port 8 is formed so as to extend obliquely toward the lower edge of the shank portion 2 as it goes toward the rear end of the tool body 1 as shown in FIG.

  In the present embodiment, the chip discharge path 9 is formed by notching a side surface of the shank portion 2 on the second end 4e2 side by a plane parallel to the axis O except for a front end and a rear end. An outer peripheral notch 10 extending in the longitudinal direction of the tool body 1 is formed on the side of the second end 4e2 of the shank portion 2. The outer peripheral notch 10 has an arc-shaped cross section centering on the axis O in the direction of the axis O. The outer peripheral notch 10 is formed by the detachable attachment of the extending plate-shaped outer peripheral cover 11 by the clamp screw 12. At the rear end of the outer peripheral cover 11, a rectangular chip discharge port 11a is opened.

  The outer peripheral cutout 10 has a rectangular shape as shown in FIG. 9 when viewed from the second end 4e2 side inside the plane cut out parallel to the axis O as described above. On one end 4e1 side, a groove 10a is formed, which is slightly recessed and extends parallel to the axis O. Further, at the rear end of the groove 10a, there is formed a recess 10b which is slightly further recessed on the first end 4e1 side, and the recess 10b is formed from the second end 4e2 side. As shown in FIG. 9, the tool body 1 is formed in an elliptical shape, and the inner wall surface on the front end side of the tool main body 1 is inclined toward the first end 4 e 1 side toward the rear end side. .

  A connection member 13 having a substantially cylindrical outer shape connected to a chip suction means (not shown) such as a dust collector is attached to the chip discharge port 11 a of the outer peripheral cover 11. Plate-like connecting portions 13a extending toward the first end 4e1 are formed on the upper edge and the lower edge of the connecting member 13, and these connecting portions 13a are formed on the shank portions 2 of the tool body 1. The upper and lower edges of the connecting member 13 are slid into contact with the notch surface 2a, and the clamp screw 13b inserted into the connecting portion 13a is screwed into the notch surface 2a. Is perpendicular to the axis O of the tool body 1 and attached to the second end 4e2 side. The inner peripheral portion of the connecting member 13 has a rectangular cross section corresponding to the chip discharge port 11a of the outer peripheral cover 11, and is in close contact with the chip discharge port 11a to communicate therewith.

  Further, in the present embodiment, a tip cover 14 that covers the tip notch 4 is also detachably attached to the tip notch 4 of the blade 3. The tip cover 14 is formed in a shape such that a bottomed cylinder is divided in half along the center line. However, the lower edge of the tip cover 14 which is in close contact with the edges of the bottom 4a of the tip notch 4 on the first end 4e1 side and the second end 4e2 side is adapted to the inclination of the bottom face 4a. 1 is inclined toward the lower edge side of the blade portion 3 toward the rear end side, and is attached so that the center line is coaxial with the axis O of the tool main body 1.

  Also, like the tip surface of the blade portion 3, the tip surface of the tip cover 14 also matches the tip surface of the blade portion 3 so as to head toward the first end 4e1 of the tool body 1 and toward the tip end. It is inclined. An air suction port 14a for sucking ambient air into the front end cover 14 is formed in a portion of the front end cover 14 near the first end 4e1 from the center of the front end surface so as to penetrate the front end cover 14. Has been open. Further, a lower edge portion 14f of the tip cover 14 extending to the first end 4e1 side of the tip cover 14 in connection with the air suction port 14a and facing the rake face 6b of the cutting insert 6 is generated by the cutting blade 6a. A small gap is provided between the cutting blades 6a so that the cut chips can be sucked together with the air sucked from the air suction port 14a. In addition, as shown in FIG. 4, this interval is formed so as to become smaller as it goes toward the first end 4e1 side (the right side in FIG. 4).

  Furthermore, a bottomed groove 14b is formed in the distal end cover 14 at the distal end on the second end 4e2 side from the outer peripheral surface of the distal end cover 14 toward the lower edge side of the blade portion 3. In addition, a plate-like protrusion 14c protruding toward the rear end is formed at the upper edge of the front cover 14, and a clamp screw 15 inserted into the bottom of the concave groove 14b and the protrusion 14c is used as a tool. The distal end cover 14 is attached to the distal end notch 4 by being screwed into the main body 1.

  Here, an insertion hole 14d through which the clamp screw 15 at the bottom of the concave groove 14b is inserted, and a screw hole 4c at the distal end side of the second end 4e2 of the bottom surface 4a of the distal cutout 4 into which the clamp screw 15 is screwed. Is perpendicular to the bottom surface 4a. The protruding piece 14c has a stepped groove 14e penetrating the protruding piece 14c. The groove 14e is closer to the second end 4e2 toward the rear end of the front cover 14. The clamp screw 15 inserted into the protruding piece 14c is inclined so that the head is in contact with the step of the stepped groove 14e. The piece 14c is clamped.

  Accordingly, by loosening the two clamp screws 15 without removing them, the tip cover 14 rotates the center line of the insertion hole 14d and the screw hole 4c perpendicularly intersecting the bottom surface 4a of the tip notch 4 as shown in FIG. As the axis C, it becomes rotatable around the rotation axis C. Then, from this state, the tip cover 14 is rotated clockwise in FIG. 2 around the rotation axis C along the bottom surface 4a, whereby the groove 14e comes out of the clamp screw 15 inserted into the protruding piece 14c, and the insert 14 is inserted. The cutting insert 6 attached to the mounting seat 5 can be exposed.

  Further, in the present embodiment, the second end of the wall surface 4b of the distal end notch 4 opposite to the cutting insert 6 provided with the cutting edge 6a when viewed from the direction facing the bottom surface 4a of the distal end notch 4. On the side of the part 4e2, a recess 4d slightly recessed from the wall surface 4b to the rear end side of the tool body 1 is formed from the outer peripheral surface of the blade part 3 on the second end 4e2 side to the chip suction port 8. . The concave portion 4d is provided on the rear end surface so that the rear end surface of the front end cover 14 on the second end 4e2 side does not hit the wall surface 4b when the front end cover 14 is rotated as described above. It is formed so as to be slightly spaced from the surrounding rotation locus.

  The chip suction-type cutting tool according to the present embodiment, which is a cutting edge replaceable boring bar configured as described above, is supported by the machine tool as described above, and has a machining hole centered on the rotation axis of the rotating work material. The inside diameter of the processing hole is processed by the cutting edge 6a of the cutting insert 6 while being inserted into the inside from the front end side and fed out. At this time, the air in the processing hole is sucked from the air suction port 14a of the tip cover 14 by the chip suction means connected to the connection member 13, and the chip is discharged from the chip suction port 8 with the chip generated by the cutting blade 6a. The chips are discharged from the chip discharge port 11a through the path 9. During the cutting, the coolant is supplied from the coolant hole 1a toward the cutting edge 6a.

  Here, in the chip suction type cutting tool having the above configuration, the chip discharge path 9 is viewed from the direction opposite to the bottom surface 4a of the tip notch 4 facing the same direction as the rake face 6b of the cutting blade 6a. Is formed on the second end 4e2 side of the intersection ridge line portion 4e of the tool body 1 and the wall surface 4b, and the front notch portion 4 is located toward the rear end side of the tool body 1 when viewed from the direction facing the bottom surface 4a. The first end 4e1 and the second end 4e2 communicate with each other through a chip suction port 8 that extends diagonally from the first end 4e1 to the second end 4e2. Therefore, the thickness of the tool body 1, particularly the shank portion 2, is less likely to be cut around the axis O, and a sufficient thickness is secured in the direction facing the rake face 6 b on which the cutting load acts on the cutting edge 6 a. be able to.

  Therefore, high rigidity can be given to the tool main body 1 with respect to the cutting load as described above. According to the chip suction type cutting tool having the above-described configuration, even when the amount of protrusion of the tool main body 1 is large, It is possible to perform high-precision machining by preventing chatter vibration or the like from being generated in the tool body 1 during cutting. In particular, in the boring bar used for the inner diameter machining as in the present embodiment, the amount of protrusion of the tool body 1 is determined by the machining depth of the machining hole of the work material. Even if it is deep, stable cutting can be performed. In addition, when the present invention is applied to such a boring bar for internal diameter machining, in the chip suction type cutting tool having the above-described configuration, the chip is discharged through the chip discharge passage 9 in the tool main body 1, and thus the chip is discharged. Rubbing between the outer periphery of the main body 1 and the inner periphery of the machining hole of the work material can be prevented, so that the outer diameter of the tool body 1 can be increased to near the inner diameter of the machining hole, and the tool body 1 Stiffness can be further secured and more stable cutting can be performed.

  In the present embodiment, an outer peripheral notch 10 is formed on the side surface of the tool body 1 on the side of the second end 4e2, and the outer peripheral notch 10 is formed by cutting the side surface in the longitudinal direction of the tool main body 1. A chip discharge path 9 is formed by detachably attaching an outer peripheral cover 11 covering the tool body 1 to the tool body 1. For this reason, chips sucked from the chip suction port 8 that extends obliquely from the first end 4e1 side to the second end 4e2 side toward the rear end side of the tool body 1 collides with the outer peripheral cover 11. Will be.

  Therefore, it is only the outer peripheral cover 11 that is scratched and damaged by the collision of the chips, and when the outer cover 11 is worn and damaged by the rubbing of the chips, it is not necessary to replace the entire tool body 1. Only the outer cover 11 needs to be replaced. Therefore, the life of the tool body 1 can be maintained long, so that efficient and economical cutting can be performed over a long period of time.

  Further, in the present embodiment, the cutting edge 6a is provided on the first end 4e1 side opposite to the second end 4e2 side of the tool main body 1 provided with the chip discharge path 9, and the bottom surface of the tip notch 4 is provided. The chip generated by the cutting edge 6a is provided at the tip end of the cutting edge 6a so that the chips are directed from the first end 4e1 side to the second end 4e2 side toward the rear end side of the tool body 1. It can be smoothly guided to the chip suction port 8 formed obliquely and discharged from the chip discharge path 9. For this reason, it is possible to prevent chips from being entangled with the opening of the chip suction port 8 and to perform more stable cutting.

  Further, in the present embodiment, a coolant hole 1a is formed on the first end 4e1 side of the tool main body 1 on which the cutting blade 6a is disposed in this way, and the coolant hole 1a is opened in the wall surface 4b of the notch 4 at the front end. Inside, coolant is supplied from the coolant hole 1a toward the cutting blade 6a. For this reason, the coolant can be efficiently supplied while securing the thickness around the axis O of the tool main body 1 and maintaining the high rigidity while preventing the coolant hole 1a from becoming unnecessarily long. By supplying the coolant, the chips can be cut or the cutting blade 6a can be cooled to extend its life.

  Furthermore, in the present embodiment, a tip cover 14 that covers the tip notch 4 is detachably attached to the tip of the tool body 1 at a distance from the cutting blade 6a. For this reason, the chips generated by the cutting blade 6a can be reliably sucked from the chip suction port 8, guided to the chip discharge path 9, and discharged without being scattered in the processing hole.

  In the present embodiment, the tip cover 14 is attached to the bottom surface 4a of the notch 4 so as to be rotatable around a rotation axis C that intersects the bottom surface 4a on the side opposite to the cutting blade 6a. Therefore, when the cutting blade 6a is formed on the cutting insert 6 detachably mounted on the insert mounting seat 5 formed on the bottom surface as in the present embodiment, the tip cover 14 is rotated in this manner. As a result, the cutting insert 6 can be exposed as described above, so that even when the cutting edge 6a is worn, the cutting insert 6 can be easily removed and reattached to the cutting edge 6a before use. The cutting insert 6 can be replaced.

  Further, in the present embodiment, when the tip cover 14 is attached to the tool body 1 so as to be rotatable around the rotation axis C on the bottom surface 4a of the tip notch 4 on the opposite side to the cutting blade 6a as described above. A recess 4 d is formed on the wall surface 4 b of the tip notch 4 on the side opposite to the cutting blade 6 a when viewed from the direction facing the bottom surface 4 a of the tip notch 4. The concave portion 4d is formed so as to have a slight interval from the rotation trajectory around the rotation axis C of the rear end surface of the front end cover 14 on the second end 4e2 side as described above. Since the interference with the rear end face of the tip cover 14 is prevented when the tip cover 14 is rotated, the tip cover 14 can be smoothly rotated, and the reattachment and replacement of the cutting insert 6 can be performed more easily. Becomes possible.

DESCRIPTION OF SYMBOLS 1 Tool main body 1a Coolant hole 2 Shank part 3 Blade part 4 Tip notch part 4a Bottom surface of tip notch part 4b Wall surface of tip notch part 4d Concave part 4e Intersection ridge part 4e of bottom surface 4a of tip notch part 4 and wall surface 4b 4e1 intersection First end 4e2 of ridge 4e 2nd end of crossed ridge 4e 5 Insert mounting seat 6 Cutting insert 6a Cutting blade 6b Rake face 7, 12, 13b, 15 Clamp screw 8 Chip suction port 9 Chip discharge path DESCRIPTION OF SYMBOLS 10 Outer peripheral cutout 11 Outer peripheral cover 11a Chip discharge port 13 Connection member 14 Tip cover 14a Air suction port O Axis line of tool body 1 C Rotation axis of tip cover 14

Claims (6)

A tip notch having a bottom surface extending in the longitudinal direction of the tool body and a wall surface extending in a direction intersecting the bottom surface and facing the tip side of the tool body is provided at a tip portion of the tool body formed in an axial shape. Is formed,
A cutting edge having a rake face facing in the same direction as the bottom face is provided on a tip outer peripheral portion of a bottom face of the tip notch portion,
At least one of the bottom surface and the wall surface of the tip notch, as viewed from the direction facing the bottom surface of the tip notch, toward the rear end side of the tool body, the bottom surface and the wall surface of the tip notch A chip suction port formed to extend obliquely from a first end side of the crossing ridge toward a second end of the crossing ridge opposite to the first end. And
A chip discharge path is formed on the second end side of the tool main body, the chip discharge path extending to the rear end side of the tool main body in communication with the chip suction port, and connected to chip suction means. Chip suction type cutting tool.   On the second end side of the tool main body, an outer peripheral notch is formed by cutting the tool main body at the second end in the longitudinal direction, and an outer peripheral cover that covers the outer peripheral notch is formed. The chip suction type cutting tool according to claim 1, wherein the chip discharge path is formed by being detachably attached to the tool main body.   3. The chip suction type cutting tool according to claim 1, wherein the cutting blade is provided on a side of the first end of a bottom surface of the notch. 3.   A coolant hole extending in the longitudinal direction of the tool main body is formed in the tool main body on the first end side of the tool main body, and is opened to a wall surface of the front notch. The chip suction type cutting tool according to any one of claims 1 to 3.   5. The tool body according to claim 1, wherein a tip cover for covering the tip notch is detachably attached to the tip of the tool body at a distance from the cutting blade. 6. A chip suction type cutting tool according to the item.   The tip cover is rotatably mounted around a rotation axis that intersects the bottom surface on the side opposite to the cutting blade on the bottom surface of the tip notch, and the wall of the tip notch has the tip notch. The chip suction type cutting tool according to claim 5, wherein a concave portion is formed on a side opposite to the cutting blade when viewed from a direction facing the bottom surface.

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