WO2017135291A1

WO2017135291A1 - Holder for blade-tip-replaceable byte

Info

Publication number: WO2017135291A1
Application number: PCT/JP2017/003566
Authority: WO
Inventors: 彰一郎渡辺; 博之乗越; 拓真木曽
Original assignee: 三菱マテリアル株式会社
Priority date: 2016-02-04
Filing date: 2017-02-01
Publication date: 2017-08-10
Also published as: JP2017136670A

Abstract

In this holder for a blade-tip-replaceable byte, an insert-mounting seat and a slit are formed on a plate-shaped insert-mounting part of a holder body. The side of the insert-mounting part on which a seating surface is formed serves as a lower jaw and the side on which a pressing surface is formed serves as an upper jaw. In the upper jaw, a recess indenting in an arcuate shape is formed on the upper jaw-side inside surface of the slit on the rear-end side in relation to the pressing surface. An arcuate groove in which the distance between an inner wall surface facing the recess and the center of the recess gradually decreases from the rear end to the front end is formed in the lower jaw.

Description

Replaceable cutting edge holder

The present invention relates to a cutting edge exchanging tool holder to which a cutting insert for grooving and parting off is detachably attached.
This application claims priority based on Japanese Patent Application No. 2016-020125 filed in Japan on February 4, 2016, the contents of which are incorporated herein by reference.

As such blade-tip-exchangeable tool holders, Patent Documents 1 to 3 form an upper jaw part and a lower jaw part by forming an insert mounting seat at the front end of a plate-like holder body, and two pins project. After the upper jaw is elastically deformed so as to be separated from the lower jaw by a wrench, the cutting insert for grooving and parting is seated on the insert mounting seat, and then the upper jaw is returned to its original state. It is described that the cutting insert is pressed and clamped.

Here, in the blade-tip-exchangeable tool holder described in Patent Document 1, a hole for inserting one pin of the wrench is formed in the upper jaw part, and an ellipse in which the other pin is inserted in the lower jaw part A groove having a shape is formed. Moreover, in the blade-tip-exchangeable cutting tool holder described in

Patent Documents

2 and 3, a hole is formed in the lower jaw part, and a groove is formed on the rear end side of the insert mounting seat of the upper jaw part. The inner wall surface of the groove facing the hole side is formed so that the distance from the center of the hole gradually decreases toward the tip side, and the other pin is grooved by rotating the wrench to the tip side around one pin. The upper jaw is pushed up by sliding in contact with the inner wall, and the upper jaw is elastically deformed so as to be separated from the lower jaw.

JP-T-2001-517555 JP 2000-343304 A Japanese Patent No. 3657613

However, since the upper jaw portion can be elastically deformed, the thickness between the upper surface and the pressing surface that presses the cutting insert is small, so that the upper jaw portion is similar to the blade tip replaceable bite holder described in Patent Document 1. If a hole is formed in the part, the rigidity of the upper jaw part is unnecessarily lowered, and the clamping force for clamping the cutting insert may be insufficient. Moreover, in the blade-tip-exchangeable tool holder described in

Patent Documents

2 and 3, the inner wall surface of the groove with which the other pin of the wrench slides is formed on the upper jaw side. The front end side of the inner wall surface is worn, and the upper jaw cannot be sufficiently elastically deformed, resulting in a shortened holder life.

The present invention has been made under such a background, and it is possible to obtain a sufficient clamping force without impairing the rigidity of the upper jaw part, and wear on the upper jaw part even when the cutting insert is repeatedly attached and detached. An object of the present invention is to provide a blade-type replaceable cutting tool holder that can prevent the occurrence and extend the life of the holder.

In order to solve the above-described problems and achieve such an object, the blade tip replaceable cutting tool holder according to the present invention is provided at a plate-like insert mounting portion provided on a holder body, at a tip portion of the insert mounting portion. An insert mounting seat that is opened and detachably mounted with a cutting insert for grooving and parting off is formed so as to penetrate in the thickness direction of the insert mounting portion, and at the rear end portion of this insert mounting seat A slit is formed which communicates with the insert mounting seat and extends to the rear end side, and one of the two inner side surfaces of the insert mounting seat facing the slit in between is the cutting insert. The other inner side surface is a pressing surface that presses the cutting insert toward the seating surface side, and the insert mounting portion includes: The side on which the seating surface is formed is a lower jaw, and the side on which the pressing surface is formed is an upper jaw that can be elastically deformed in a direction away from the lower jaw. The upper jaw side inner surface of the slit on the rear end side of the pressing surface is formed with a concave portion that is recessed in an arc shape from the upper jaw side inner surface when viewed from the plate thickness direction, and the lower jaw portion, An arcuate groove is formed in an arc shape when viewed from the plate thickness direction, and the distance between the inner wall surface facing the recess and the center of the recess gradually decreases from the rear end toward the front end.

In the blade holder with a replaceable cutting edge configured as described above, one pin of a wrench with two protruding pins as described above is inserted into the recess and the other pin is inserted into the rear end of the arc-shaped groove. The upper jaw is pushed up and elastically deformed by rotating the wrench around the one pin toward the distal end. Here, the distance from the center of the recess gradually decreases from the rear end toward the front end, and the arcuate groove having the inner wall surface with which the other pin is in sliding contact is formed in the lower jaw portion, so that the upper jaw portion is worn out And a long holder life can be obtained.

The recess into which one pin of the wrench is inserted is formed so as to be recessed in an arc shape from the upper jaw side inner surface of the slit on the rear end side than the pressing surface of the upper jaw portion. The upper jaw is not greatly cut out as in the case of forming, and the area of the pressing surface is not reduced. For this reason, it can suppress that the rigidity of an upper jaw part falls and can ensure the area of a press surface large, and it becomes possible to attach a cutting insert with sufficient clamp intensity | strength.

Further, when the concave portion into which one of the pins is inserted is formed so as to be recessed in an arc shape, a large width can be secured between the concave portion and the upper surface of the upper jaw portion. For this reason, a coolant hole is formed in at least the upper jaw of the insert mounting portion within a range not impairing the rigidity of the upper jaw, and is opened at the distal end of the upper jaw through the space between the recess and the upper surface of the upper jaw. Therefore, efficient cooling and lubrication of the cutting blade of the cutting insert can be achieved.

As explained above, according to the holder for a cutting edge replaceable bite of the present invention, it is possible to securely clamp the cutting insert for a long period of time by preventing shortening of the holder life due to wear of the upper jaw portion and insufficient clamping strength due to lowering of rigidity. Thus, stable grooving and parting off can be performed.

It is a perspective view of the state where the cutting insert was attached to the holder for cutting-blade exchange type cutting tools concerning one embodiment of the present invention. It is a side view of the state shown in FIG. FIG. 2 is an enlarged side view of the insert mounting portion in the state shown in FIG. 1. It is a perspective view of the state where the cutting insert was removed from the holder for cutting-edge-exchange-type cutting tools concerning one embodiment of the present invention. It is a side view of the state shown in FIG. FIG. 6 is a (a) perspective view, (b) side view, and (c) front view of a wrench used to attach and detach the cutting insert in the embodiment shown in FIGS. 1 to 5.

FIGS. 1 to 5 show an embodiment of the present invention, and FIG. 6 shows a wrench W used to attach and detach the cutting insert I in this embodiment. Among these, in the wrench W, the wrench main body W1 is formed of a steel material or the like into a shaft having a regular hexagonal cross section as shown in FIG. 6 in this embodiment, and the tip of the wrench main body W1 (FIGS. 6 (a) to ( In the upper part in c), two cylindrical pins P1 having the same shape and the same size projecting in parallel to each other perpendicular to the longitudinal direction of the wrench body W1 (the vertical direction in FIGS. 6B and 6C), P2 is formed at intervals in the longitudinal direction.

In the blade tip replaceable cutting tool holder of the present embodiment, the holder body 1 is formed of a steel material or the like into a substantially rectangular thin plate, and the two parallel side surfaces 1A forming the rectangular shape and the longitudinal direction of the rectangle ( 2, 2 and 3 are provided with two end faces 1B along the short side of the rectangle and two elongated faces 1C along the long side of the rectangle. Further, the holder body 1 rotates 180 ° around a center line extending in the plate thickness direction of the holder body 1 (direction orthogonal to the drawings in FIGS. 2, 3 and 5) through the rectangular center formed by the side surface 1A. It has a symmetrical shape. Note that, in the blade tip replaceable cutting tool holder of the present embodiment, the longitudinal direction of the rectangle formed by the side surface 1A is referred to as “longitudinal direction”, and the direction away from the center of the rectangle in the longitudinal direction (left side in FIG. 3). Is referred to as “front end side”, and the direction toward the center (right side in FIG. 3) is referred to as “rear end side”. The thickness direction of the holder body 1 (the normal direction of the side surface 1A) is referred to as the “thickness direction”.

In the holder main body 1 of the present embodiment, two corners (upper left and lower right corners in FIGS. 2 and 5) located on one diagonal line formed by the side surface 1 </ b> A are plate-like as in the holder main body 1. Each of the insert mounting portions 2 is formed. At these corners, the elongated surface 1C is formed with a notched portion 1D in which the elongated surface 1C is cut out in a concave arc shape when viewed from the thickness direction. On the opposite side (rear end side) from a position slightly spaced in the longitudinal direction from the notch 1D, the elongated surface 1C is formed in a convex V shape in a cross section orthogonal to the longitudinal direction.

Each insert mounting portion 2 has an insert mounting seat 3 that opens at the tip (upper left portion in FIG. 3) of each insert mounting portion 2. The thickness of the insert mounting portion 2 is the same as the thickness direction of the holder body 1. It is formed so as to penetrate in the direction. The insert mounting seat 3 is an elongated surface of the holder main body 1 where the corner portion where the insert mounting portion 2 is formed is located toward the rear end side (right side in FIG. 3) of the insert mounting portion 2 in the longitudinal direction of the holder main body 1. It inclines from 1C toward the elongated surface 1C on the opposite side. A slit 4 is formed at the rear end portion of the insert mounting seat 3 so as to communicate with the insert mounting seat 3 and extend toward the rear end side of the insert mounting portion 2. The slit 4 is formed so as to penetrate the holder body 1 in the plate thickness direction.

Therefore, the insert mounting seat 3 is formed with two inner surfaces facing each other with the slit 4 therebetween. Of these, one inner side facing the corner side where the insert mounting portion 2 is formed is a seating surface 3A on which the cutting insert I is seated, and the other inner side presses the cutting insert I toward the seating surface 3A. It is set as the pressing surface 3B to do. The seating surface 3A and the pressing surface 3B extend substantially in parallel as shown in FIG. 5 in a state where the cutting insert I is removed, and a cross section orthogonal to the direction in which the seating surface 3A and the pressing surface 3B extend. Is formed in a convex V shape. As the seating surface 3A and the pressing surface 3B move toward the rear end side, the elongated surface 1C (the elongated surface 1C on the lower jaw 2A side described later) that faces the elongated surface 1C on which the corner portion where the insert mounting portion 2 is formed is located. Inclined to approach.

Further, the rear end portion of the insert mounting seat 3 between the seating surface 3A and the pressing surface 3B intersects the seating surface 3A at an acute angle and intersects the pressing surface 3B at an obtuse angle. The contact surface 3C extending in the direction is formed to face the front end side with a space from the seating surface 3A and the pressing surface 3B. Further, a circular hole is formed between the seating surface 3A and the contact surface 3C of the insert mounting seat 3 to form an escape portion 3D.

Of the two portions of the insert mounting portion 2 divided by the insert mounting seat 3 and the slit 4, the side on which the seating surface 3A is formed is the lower jaw portion 2A and the side on which the pressing surface 3B is formed. Is the upper jaw 2B. Here, the width of the upper jaw part 2B in the direction along the end face 1B is sufficiently smaller than the width of the lower jaw part 2A, and the upper jaw part 2B is centered on the rear end side of the slit 4 with respect to the lower jaw part 2A. It can be elastically deformed in the direction of separation.

The slit 4 is seated at a steep angle (with an obtuse angle with the pressing surface 3B) from the space between the contact surface 3C and the pressing surface 3B of the insert mounting seat 3 toward the rear end side. After extending short in the direction away from the surface 3A, bend in the same direction (toward the rear end) to extend longer at a gentler angle (with a larger angle with respect to the pressing surface 3B). It is formed with a substantially constant width. A circular hole 4 </ b> A having a diameter larger than the width of the slit 4 is formed at the rear end of the slit 4. Further, of the two inner surfaces facing each other of the slit 4, the inner surface on the upper jaw 2 </ b> B side is an upper jaw side inner surface 4 </ b> B that bends similarly to the slit 4.

The upper jaw side inner side surface 4B is formed with a recess 5 that is recessed in an arc from the upper jaw side inner side surface 4B when viewed from the plate thickness direction (when viewed from the side of the holder body 1). The concave portion 5 in the present embodiment is formed so as to be recessed in a substantially semicircular shape in the bent portion of the upper jaw side inner side surface 4B as in the case of the slit 4 as described above. It is formed on the rear end side of the insert mounting portion 2 with respect to the surface 3B. The inner diameter of the semicircular recess 5 is such that the cylindrical pins P1 and P2 of the wrench W can be fitted.

On the other hand, in the lower jaw 2A, an arcuate groove 6 having an arcuate center that is substantially the center of a semicircle (arc) formed by the recess 5 when viewed from the plate thickness direction is spaced apart from the insert mounting seat 3 above. It is formed so as to extend from the position substantially equal to the concave portion 5 to the rear end side in the longitudinal direction. Thus, the arc-shaped groove 6 is provided on the rear end side with respect to the pressing surface 3B of the insert mounting seat 3. The groove width of the arc-shaped groove 6 is a constant width slightly larger than the diameters of the pins P1 and P2 of the wrench W, but the inner wall surface of the arc-shaped groove 6 facing the concave portion 5 among the two inner wall surfaces facing each other. 6A is formed so that the distance from the center of the recess 5 gradually decreases as it goes from the rear end to the front end of the arc-shaped groove 6.

Specifically, in the arc-shaped groove 6, the distance between the center of the groove width at the rear end and the center of the recess 5 is set equal to the distance between the centers of the two pins P 1 and P 2 of the wrench W. Accordingly, as shown in FIGS. 1 and 2, the pin P1 on the front end side of the wrench W is fitted into the recess 5, and the pin P2 on the rear end side is inserted into the rear end of the arc-shaped groove 6, and this pin is inserted. A slight gap is provided between P2 and the two inner wall surfaces of the arc-shaped groove 6.

On the other hand, at the tip of the arcuate groove 6, the distance between the center of the recess 5 and the inner wall surface 6A facing the recess 5 side of the arcuate groove 6 is between the centers of the two pins P1 and P2 of the wrench W. Is set to be slightly smaller than the sum of the distance and the radius of the pin P2. That is, strictly speaking, the center of the arc formed by the arc-shaped groove 6 is eccentric with respect to the center of the semicircle formed by the recess 5. Therefore, when the wrench W is rotated to the tip side around the pin P1 from the state shown in FIGS. 1 and 2, and the pin P2 is moved to the tip of the arcuate groove 6 as shown in FIGS. P2 slides on the inner wall surface 6A and the upper jaw 2B is pushed up by the pin P1, and the upper jaw 2B is elastically deformed in a direction away from the lower jaw 2A as described above.

Further, as shown by a broken line in FIG. 3, the insert mounting portion 2 is provided with a coolant hole 7 at least in the upper jaw portion 2B, and the coolant hole 7 is a distal end portion (a surface facing the distal end side) of the upper jaw portion 2B. Is open. In the coolant hole 7 of the present embodiment, a bottomed coolant supply hole 7A is formed perpendicularly to one side surface 1A of the holder body 1, and from the coolant supply hole 7A to the distal end side of the insert mounting portion 2 in the longitudinal direction. A first coolant supply path 7B is bored toward the end surface 1B of the lower jaw 2A. However, the opening in the end surface 1B of the first coolant supply path 7B is sealed with a plug 7C.

On the other hand, from the elongated surface 1C of the holder main body 1 on the lower jaw 2A side, the second coolant supply path 7D intersecting the first coolant supply path 7B is inserted toward the opposite elongated surface 1C on the upper jaw 2B side. It extends toward the distal end side of the portion 2 and reaches the front of the elongated surface 1C on the upper jaw portion 2B side. The opening in the elongated surface 1C on the lower jaw 2A side of the second coolant supply path 7D is also sealed with the plug 7C.

Then, from the end of the second coolant supply path 7D in front of the elongated surface 1C on the upper jaw 2B side, there is a gap between the elongated surface 1C on the upper jaw 2B side, the circular hole 4A of the slit 4, and the concave portion 5. The upper jaw side coolant discharge hole 7E is drilled in the upper jaw portion 2B so as to be inclined slightly toward the lower jaw portion 2A as it goes toward the distal end side of the insert mounting portion 2. The hole 7E opens in the notch 1D. In the present embodiment, the lower jaw portion 2A is also provided with a lower jaw portion side coolant discharge hole 7F extending obliquely toward the upper jaw portion 2B as it goes from the distal end portion of the first coolant supply path 7B toward the distal end side. The opening 1 is open to the end surface 1B in the vicinity of the seating surface 3A of the insert mounting seat 3.

The above-mentioned cutting insert I for grooving / cut-off processing detachably attached to such a blade-tip-exchange-type tool holder is formed of a hard material such as a cemented carbide having a hardness higher than that of the holder body 1. And a thick plate-like insert body 11 having a substantially eccentric hexagon as shown in FIG. Of the six end surfaces (side surfaces) of the insert body 11, two end surfaces (two opposite side surfaces on which cutting edges 12 to be described later are not formed) facing away from each other are separated from the rear end side (cutting edge 12). The angle is set so that the interval becomes slightly wider as it goes to (direction). One of the two end surfaces is a mounting surface 11A seated on the seating surface 3A of the insert mounting seat 3, and the other is a pressed surface 11B pressed by the pressing surface 3B, and the seating surface 3A and the pressing surface, respectively. It is formed in a concave V-shaped cross section that can contact 3B. Moreover, the space | interval between these attachment surfaces 11A and the to-be-pressed surface 11B is set slightly larger than the space | interval of the seating surface 3A in the state from which the cutting insert I was removed, and the press surface 3B.

Further, the mounting surface 11A is seated on the seating surface 3A and the pressed surface 11B is pressed by the pressing surface 3B so that the cutting insert I is mounted on the insert mounting seat 3 toward the distal end side of the insert mounting portion 2. Of the two end surfaces of the insert body 11 to be obtained, the end surface on the upper jaw portion 2B side that is continuous with the pressed surface 11B is a rake surface 11C, and the end surface on the lower jaw portion 2A side that is continuous with the mounting surface 11A is a relief surface 11D, A cutting edge 12 longer than the plate thickness of the holder body 1 is formed at the intersection ridge line portion between the rake face 11C and the flank face 11D.
Furthermore, in this mounting state, the end surface facing the pressed surface 11B and directed to the rear end side of the insert mounting portion 2 is in contact with the contact surface 3C of the insert mounting portion 2, and is connected to the mounting surface 11A to insert mounting. The end surface directed toward the rear end side of the portion 2 is accommodated in the escape portion 3D.

In order to attach such a cutting insert I to the cutting edge replaceable cutting tool holder of the above-described embodiment, the pin P1 of the wrench W is fitted into the recess 5 and the pin P2 is inserted into the rear end of the arc-shaped groove 6 as described above. To do. The wrench body W1 is rotated around the pin P1 toward the distal end side of the insert mounting portion 2 to bring the pin P2 into sliding contact with the inner wall surface 6A facing the concave portion 5 side of the arc-shaped groove 6, thereby pushing up the upper jaw portion 2B to be elastically deformed. . At this time, the interval between the seating surface 3A of the insert mounting seat 3 and the pressing surface 3B is set to be larger than the interval between the mounting surface 11A of the insert body 11 and the pressed surface 11B. The insert body 11 can be inserted into the insert mounting seat 3 from the distal end side of the insert mounting portion 2 until it is seated on the seating surface 3A and the insert body 11 contacts the contact surface 3C.

Then, when the wrench body W1 is rotated to the rear end side from the above state and the pin P2 is returned to the rear end of the arc-shaped groove 6, the elastically deformed upper jaw portion 2B also returns to the original state and is inserted. The pressed surface 11B of the main body 11 is pressed by the pressing surface 3B, the insert main body 11 is sandwiched between the seating surface 3A and the pressing surface 3B, and the cutting insert I is clamped. Further, when removing the cutting insert I, the upper jaw 2B is pushed up and elastically deformed in the same manner as described above, and the insert body 11 is extracted from the insert mounting seat 3.

In the blade-tip replaceable cutting tool holder configured as described above, the arc-shaped groove 6 formed with the inner wall surface 6A with which the pin P2 is slidably contacted when the upper jaw portion 2B is pushed up and elastically deformed has a wide width of the insert mounting portion 2. Since it is formed on the lower jaw 2A, even if the cutting insert I is repeatedly attached and detached, the narrow upper jaw 2B is less likely to be worn by the sliding contact of the pin P2. For this reason, damage to the upper jaw 2B on which the pressing surface 3B that presses the cutting insert I by elastic deformation can be suppressed, and the life of the holder can be extended.

Furthermore, in the blade tip replaceable cutting tool holder having the above-described configuration, the recess 5 into which the pin P1 of the wrench W is inserted and fitted is circular from the upper jaw side inner side surface 4B of the slit 4 on the rear end side with respect to the pressing surface 3B. It is formed to be recessed in an arc shape. Therefore, the portion where the upper jaw 2B is cut out can be made smaller than when the circular hole is formed in the upper jaw 2B and the pin P1 is fitted, and the area of the pressing surface 3B is not reduced. Therefore, the area of the pressing surface 3B can be secured while suppressing the rigidity of the upper jaw portion 2B from being lowered, and the cutting insert I is pressed with a sufficient clamping force and attached to the insert mounting portion 2 for stable grooving.・ Partial cutting can be performed.

Further, in this embodiment, the pin P1 of the wrench W is inserted into the concave portion 5 recessed in an arc shape from the upper jaw side inner side surface 4B, and therefore the upper surface of the concave portion 5 and the upper jaw portion 2B (this embodiment) In the embodiment, a certain amount of width can be secured between the cutout portion 1D). In conjunction with this, in the present embodiment, at least the upper jaw 2B is provided with a coolant hole 7, and the upper jaw side coolant discharge hole 7E is opened at the notch 1D at the distal end of the upper jaw 2B.

Therefore, a coolant such as cutting fluid is supplied from the upper jaw side coolant discharge hole 7E to the cutting blade 12 along the rake face 11C of the cutting insert I without cutting the rigidity of the upper jaw 2B more than necessary. Therefore, the cutting edge 12 and the cutting part of the work material can be efficiently cooled and lubricated. Moreover, in the present embodiment, since the lower jaw side coolant discharge hole 7F is also opened on the end face 1B in the vicinity of the insert mounting seat 3, further reliable cooling and lubrication can be achieved.

Note that the present invention is not limited to the above-described embodiment, and additions, omissions, substitutions, and other modifications of the configuration can be made without departing from the spirit of the present invention. Further, the present invention is not limited by the above-described embodiments, and is limited only by the scope of the claims.
For example, the concave portion 5 does not have to be a semicircle having a central angle of 180 ° when viewed from the thickness direction of the holder body 1 as in the present embodiment. Arc).
In the present embodiment, the holder body 1 itself is plate-shaped, and the insert mounting portion 2 is also formed in a plate shape along with this. For example, a groove is formed in the inner peripheral surface of a cylindrical work material. In the case of a blade-type replaceable cutting tool holder for inner diameter processing for machining, a plate-shaped insert mounting portion 2 may be provided at the tip of the shaft-shaped holder body perpendicular to the axis of the holder body.

According to the present invention, a sufficient clamping force can be obtained without impairing the rigidity of the upper jaw, and wear of the upper jaw can be prevented even if the cutting insert is repeatedly attached and detached, thereby extending the life of the holder. Therefore, the cutting insert can be securely clamped over a long period of time, and stable grooving and parting off can be performed.

DESCRIPTION OF SYMBOLS 1 Holder body 2 Insert mounting part 2A Lower jaw part 2B Upper jaw part 3 Insert mounting seat

3A Seating surface

3B Press surface 4 Slit 4B Slit 4 Upper jaw side inner surface 5 Recessed part 6 Arc-shaped groove 6A The inner side which faces the recessed part 5 side of the arc-shaped groove 6 Wall surface 7 Coolant hole 11 Insert body 11A Mounting surface of insert body 11 11B Pressed surface of insert body 11 12 Cutting blade W Wrench P1, P2 Pin I Cutting insert

Claims

An insert mounting seat is provided on a plate-like insert mounting portion provided in the holder main body, to which a cutting insert for grooving and parting off is detachably mounted at the tip of the insert mounting portion. It is formed so as to penetrate in the thickness direction, and at the rear end portion of this insert mounting seat, a slit extending to the rear end side in communication with the insert mounting seat is formed,
Of the two inner surfaces of the insert mounting seat facing each other with the slit in between, one inner surface is a seating surface on which the cutting insert is seated, and the other inner surface is the seating of the cutting insert. It is a pressing surface that presses to the surface side,
Of the insert mounting part, the side on which the seating surface is formed is a lower jaw part, and the side on which the pressing surface is formed is an upper jaw part that can be elastically deformed in a direction away from the lower jaw part. ,
In the upper jaw part, a concave part that is recessed in an arc shape from the inner side surface of the upper jaw part side when viewed from the plate thickness direction is formed on the inner side of the upper jaw part side of the slit on the rear end side from the pressing surface, The lower jaw part is formed with an arcuate groove as viewed from the plate thickness direction, and an arcuate groove is formed such that the distance between the inner wall surface facing the recess and the center of the recess gradually decreases from the rear end toward the tip. A blade holder with a replaceable cutting edge.
The blade tip replaceable bite holder according to claim 1, wherein a coolant hole is formed in at least the upper jaw portion of the insert mounting portion and opens at a distal end portion of the upper jaw portion.