JP2014121770A - Cutting insert and cutting insert manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to stably manufacture a high-quality cutting insert capable of facilitating positioning stuck surfaces of a plurality of split bodies, the stuck surfaces being closely bonded to each other while restricting these split bodies from sliding during sintering, to make the cutting insert easily applicable for various insert shapes, and to make it possible to easily manufacture the cutting insert.SOLUTION: A cutting insert includes a plate-like insert main body having reverse-symmetric front and back surfaces. The insert main body is formed by sintering a plurality of plate-like split bodies 20 made of green compact in a state of being stuck to each other in an insert center line C direction of the insert main body. On a stuck surface 21 of each split body 20, a plurality of positioning portions 24 each including a convex portion 22 and a concave portion 23 adjacent to each other are formed around the insert center line C. In a state in which the convex portions 22 and the concave portions 23 of the positioning portions 24 facing each other of the split bodies 20 stuck to each other are fitted into the concave portions 23 and the convex portions 22, the stuck surfaces 21 of these split bodies 20 are bonded to each other.

Description

  The present invention relates to a cutting insert that is detachably mounted on a cutting edge exchangeable cutting tool such as a cutting edge exchangeable end mill, and a manufacturing method thereof.

  Conventionally, for example, a polygonal plate-shaped cutting insert made of a hard material such as cemented carbide, as shown in Patent Document 1 below, is known. This cutting insert is formed by sintering a pair of plate-like divided bodies (embossed bodies) made of green compacts having the same shape and bonded together in the thickness direction of the cutting insert. ing.

  In this way, by forming the cutting insert by pasting the divided bodies together, the cutting insert can be used as a double-sided type so that a large number of cutting edges can be secured and the tool life can be extended. Moreover, it is easy to give a positive clearance angle to the flank adjacent to the cutting edge, and the sharpness of the cutting edge with respect to the work material can be enhanced.

  In addition, when laminating and sintering a pair of divided bodies, for example, the action of a binder (molding aid such as an organic material) component that exudes from the laminating surface, vibration during sintering, impact during degassing, etc. Therefore, there is a possibility that the bonded surfaces of these divided bodies slide unintentionally and are joined in a misaligned state. Therefore, in Patent Document 1, a convex portion and a concave portion that are separated from each other are formed on the bonding surface of the divided body, and the opposing convex portion and the concave portion of the bonding surfaces of the pair of divided bodies are engaged with each other. The positional deviation between these divided bodies is suppressed by sintering with.

Japanese Patent Laid-Open No. 5-285708

However, the above-described conventional cutting insert still has room for improvement in preventing the positional deviation between the divided bodies during sintering.
Specifically, in the convex portion and the concave portion shown in FIG. 5 and FIG. 6 of the above-mentioned Patent Document 1, although they are engaged with each other, the sliding movement between the bonding surfaces of the divided bodies is all directions in the surface direction. However, there is a possibility that the divided bodies slide and move and are displaced.

Moreover, in the convex part (protrusion 3) and the concave part (concave part 4) shown by FIG. 3 of the said patent document 1, these are fitted mutually, and the sliding movement of bonding surfaces is all directions of a surface direction. It will be regulated. However, in this case, a slight gap (clearance) is provided to stably fit the convex part and the concave part, and the gas generated in the gap during the degreasing process expands in the next sintering process and is bonded together. There is a possibility that the surfaces are joined without being in close contact (that is, in a partially floating state).
Specifically, the organic material (molding aid) added in the green compact molding process for molding the divided body by press molding (mold molding) is decomposed in a subsequent degreasing process to generate gas, Gas accumulated in the gap between the convex portion and the concave portion, and further expanded in the next sintering step, thereby separating the bonded surfaces and reducing the adhesion.

  In addition, the protrusions and the recesses are formed one by one on the bonding surface of the divided body, but there are particularly many cutting inserts such as a triangular plate shape or a pentagonal plate shape having odd corners on the polygonal surface. When the above configuration is applied to a cutting insert that is not 180 ° rotationally symmetric with respect to the center of the square surface (insert center line), the direction in which the divided bodies can be bonded together is limited, and the production is limited. It becomes complicated.

  The present invention has been made in view of such circumstances, and it is easy to align the bonding surfaces of a plurality of divided bodies, and the bonding surfaces are controlled while the slide movement of these divided bodies is restricted during sintering. An object of the present invention is to provide a cutting insert that can be manufactured in a stable manner and can be manufactured stably and can be easily applied to various insert shapes. It is said.

In order to achieve the above object, the present invention proposes the following means.
That is, the present invention is a cutting insert that is detachably mounted on an insert mounting seat formed on a tool body of a cutting edge exchangeable cutting tool, and has a plate shape, front and back surfaces facing the insert center line direction, and these It has a side surface that is arranged around the front and back surfaces and faces the insert radial direction perpendicular to the insert center line, and a cutting blade that is formed at the intersection ridge line part between the front and back surfaces and the side surface, and has a reverse symmetric shape. Having an insert body, the insert body is formed by sintering a plurality of plate-like divided bodies made of green compact in a state where they are laminated in the insert center line direction of the insert body, A plurality of alignment portions each having a convex portion and a concave portion adjacent to each other around the insert center line are formed on the bonding surface of the divided body, and the pair of the divided bodies to be bonded to each other. In a state in which said recess and said protrusion in said alignment portions is fitted to the bonding surfaces of these divided bodies is characterized in that it is joined.
Further, the present invention is a cutting insert that is detachably attached to an insert mounting seat formed on a tool body of a cutting edge exchangeable cutting tool, and has a plate shape, front and back surfaces facing the insert center line direction, An insert that is arranged around the back surface and faces the insert radial direction orthogonal to the insert center line, and a cutting blade formed at the crossing ridge line portion between the front and back surfaces and the side surface, and an inverted symmetrical shape The insert body is formed by sintering a plurality of plate-like divided bodies made of green compact in a state where they are bonded together in the insert center line direction of the insert body. An alignment portion having a convex portion and a concave portion is formed on the bonding surface of the body, and the convex portions at the alignment portions facing each other of the divided bodies to be bonded to each other are formed. In a state where the concave portion and the concave portion are fitted, the bonded surfaces of the divided bodies are joined to each other, and a communication path that connects the alignment portion and the outside of the insert main body is formed in the insert main body. It is characterized by being.
Further, the present invention is a method for manufacturing a cutting insert for manufacturing the above-mentioned cutting insert, wherein the divided body is formed by die molding, and a positioning having a convex portion and a concave portion on a bonding surface of the divided body. In the state in which the convex portions and the concave portions in the green compact forming step for forming the portions and the alignment portions facing each other of the divided bodies to be bonded to each other are fitted, the bonded surfaces of these divided bodies are It has the bonding process to join, the degreasing process which degreases the shaping | molding adjuvant contained in the said division body bonded together, and the sintering process which sinters the said division bodies bonded together, It is characterized by the above-mentioned.

  According to the cutting insert of the present invention and the manufacturing method thereof, a plurality of divided bodies made of a plate-like green compact are arranged in the insert center line direction of the insert body (the insert body forming the plate shape and the thickness direction of the divided body). At the time of pasting, by fitting the convex part and the concave part of the opposing positioning parts formed on the pasting surfaces of these divided bodies with each other, the positioning between these pasting surfaces can be performed easily and accurately, By this fitting, the sliding movement between the bonding surfaces of the divided body during sintering is restricted in all directions in the surface direction. This makes it easier to prevent the occurrence of steps due to misalignment between the bonded surfaces on the outer peripheral surface (side surface) of the sintered insert body, improving the appearance quality of the cutting insert and attaching it to the insert mounting seat. Further, the position of the cutting edge of the cutting insert is also determined with high precision, and the quality of cutting using this cutting insert is enhanced.

  In addition, since the alignment portion of the bonding surface has a convex portion and a concave portion adjacent to each other around the insert center line, for example, a polygonal surface facing the insert center line direction (thickness direction) of the insert body is an odd corner. It can be easily applied to various insert shapes such as an insert shape (that is, when the insert body is a triangular plate shape, a pentagonal plate shape, or the like).

Specifically, for example, in the conventional configuration disclosed in Japanese Patent Laid-Open No. 5-285708, the protruding portions and the recessed portions are formed one by one on the bonding surface of the divided body. In the recess, when applied to cutting inserts that are not 180 ° rotationally symmetric with respect to the center of the polygonal surface (insert center line), such as the odd-numbered cutting inserts described above, bonding is performed when the divided bodies are bonded together. The possible orientation (the relative position in the circumferential direction around the insert centerline) is limited, and the manufacturing becomes complicated.
On the other hand, according to the above-described configuration of the present invention, even in the case of the odd-numbered corner cutting insert, for example, the alignment portions are arranged corresponding to the respective corners (corner portions of the polygonal surface). It becomes difficult to limit the direction in which bonding can be performed when bonding, and manufacturing can be easily performed regardless of the insert shape.

In addition, since a communication passage that connects the alignment portion and the outside of the insert body is formed in the insert body, a slight gap (fitting clearance) is provided between the protrusion and the recess to be fitted to each other. Even if it is provided, fluid such as gas generated in the gap during the degreasing process and exuded binder component is discharged to the outside of the insert body through this communication path, and at the time of the next sintering process Expansion of the gap is also prevented, and the phenomenon of lifting between the bonded surfaces is prevented. As a result, the close contact state between the bonded surfaces of the divided bodies is satisfactorily maintained during sintering, so that the insert body is stably sintered with high rigidity and high quality.
Specifically, even if a molding aid such as an organic material added in a green compact molding process for molding the divided body by die molding such as press molding is decomposed in a later degreasing process, gas is generated. The gas is discharged from the communication path to the outside of the insert without accumulating in the gap between the convex part and the concave part, and is also prevented from expanding in the gap in the next sintering step. The state is maintained well.

  As described above, according to the present invention, it is easy to align the bonded surfaces of the divided bodies that are bonded to each other, and the bonded surfaces are in close contact with each other while the slide movement of these divided bodies is restricted during sintering. Thus, the insert body is manufactured accurately and stably in a predetermined shape. Therefore, the cutting insert can be stably manufactured with high quality and high rigidity. Furthermore, it can be easily applied to various insert shapes and is easy to manufacture.

  Further, in the cutting insert of the present invention, the communication path includes a groove portion formed on the bonding surface, and the groove portion is a peripheral edge of the bonding surface from at least one of the convex portion and the concave portion of the alignment portion. It is good also as extending over the part.

  In this case, since the communication path can be easily formed and the communication state in the groove portion can be visually recognized until just before the divided bodies are bonded to each other, the above-described effects of the communication path are more reliably achieved. In addition, the groove portion communicates with at least one of the convex portion and the concave portion of the alignment portion and extends to the peripheral portion of the bonding surface, so that the groove portion fits into the convex portion or the concave portion of the one alignment portion with which the groove portion communicates. The concave portion or the convex portion of the other alignment portion to be joined also communicates with the outside of the insert main body through this groove portion, that is, the communication path is formed by the groove portion, and the above-described operational effects are obtained.

  Further, by forming the communication path by the groove portion of the bonding surface, it is possible to ensure a large distance from each cutting blade located on the outer peripheral edge of the front and back surfaces facing the insert center line direction to the communication path, The cutting load acting on the cutting blade during cutting can be prevented from being transmitted to the vicinity of the communication path through the inside of the insert body, and the rigidity of the insert body is ensured.

  In the cutting insert of the present invention, the insert body is formed with a mounting hole penetrating the insert body in the insert center line direction, and the communication path is opened to the mounting hole. Also good.

  In this case, since the communication path is opened to the inner peripheral surface (mounting hole) of the insert body, the communication path can be formed without being exposed to the outer peripheral surface (side surface) of the insert body. Can be kept good. Further, since the communication path can be arranged at a large distance from the cutting blade that cuts into the work material in the cutting insert, it is possible to prevent a large cutting load from acting on the communication path, and the strength of the cutting insert is ensured. .

  Moreover, the cutting insert of this invention WHEREIN: The said insert main body is good also as sticking together the pair of said division body made into the mutually same shape.

  In this case, the insert body can be formed by a pair of divided bodies made of one type of green compact and having the same shape as each other, and manufacturing is easy.

  Further, in the cutting insert of the present invention, the insert main body has a polygonal plate shape, the bonding surface of the divided body is a polygonal surface shape, and the number of the alignment portions is the number of the bonding surfaces. It is good also as corresponding to the number of corners.

  In this case, a plurality of alignment portions are formed on the bonding surfaces corresponding to the number of corners (number of corners) of the bonding surfaces forming a polygonal surface. Then, by arranging these alignment portions one by one, for example, corresponding to each corner of the bonding surface, it is difficult to limit the direction in which the divided bodies can be bonded together. Specifically, by aligning the positions of the opposing corners (corners) around the insert center line (in the insert circumferential direction) with each other, the alignments arranged corresponding to the respective corners. The positions of the portions are also matched with each other, and the concave portion and the convex portion of the alignment portions can be easily fitted. Therefore, according to the said structure, manufacture can be performed easily irrespective of insert shape.

  According to the cutting insert and the manufacturing method thereof of the present invention, it is easy to align the bonded surfaces of a plurality of divided bodies, and the bonded surfaces are in close contact with each other while the slide movement of these divided bodies is restricted during sintering. Therefore, the high-quality cutting insert can be stably manufactured, and can be easily applied to various insert shapes and is easy to manufacture.

It is a perspective view which shows the cutting insert which concerns on one Embodiment of this invention. It is a top view of the cutting insert of FIG. It is a side view of the arrow L direction view in FIG. It is a side view of the arrow line M direction view in FIG. It is GG sectional drawing in FIG. It is HH sectional drawing in FIG. It is an enlarged view of the I section in FIG. It is an enlarged view of the J section in FIG. It is the perspective view which shows the division body which comprises an insert main body, The figure which looked at this division body from the (a) polygon surface side of the insert center line direction, (b) The figure seen from the bonding surface side. (A) The top view which looked at the polygonal surface in the front of the division body of FIG. 9, (b) It is a side view. It is KK sectional drawing in Fig.10 (a). It is an enlarged view of the V section in FIG. It is NN sectional drawing in Fig.10 (a). It is an enlarged view of the Q section in FIG. It is an enlarged view of the R section in FIG. It is the top view which looked at the bonding surface of the division body of FIG. 9 in the front. It is an enlarged view of the S section in FIG. It is sectional drawing which shows the through-hole vicinity of the division body of FIG. It is an enlarged view of the U section in FIG. It is a perspective view which shows the blade-tip-exchange-type end mill (blade-tip-exchange-type cutting tool) which attached the cutting insert shown in FIG. It is a top view of the blade-tip-exchange-type end mill shown in FIG. It is a side view of the blade-tip-exchange-type end mill shown in FIG. It is an enlarged front view of the blade-tip-exchange-type end mill shown in FIG. It is an expansion perspective view of the end mill main part (tool main body) front-end | tip part of the blade-tip-exchange-type end mill shown in FIG.

Hereinafter, a cutting insert and a manufacturing method thereof according to an embodiment of the present invention will be described with reference to the drawings.
1 to 8 show an embodiment of the cutting insert of the present invention, and FIGS. 9 to 19 show a pair of divided bodies constituting the insert main body of the cutting insert, FIGS. Shows an edge-replaceable end mill which is an edge-replaceable cutting tool to which this cutting insert is attached.

In the cutting insert of the present embodiment, the insert body 1 is made of a hard plate selected from cemented carbide, cermet, surface-coated cemented carbide, surface-coated cermet, and the like. In this embodiment, it is formed in a regular triangular plate shape. At the center of a pair of front and back polygonal surfaces (first and second polygonal surfaces) of the insert body 1 having an equilateral triangle shape, the insert body 1 is in the thickness direction (the direction of the insert centerline C, which will be described later) A mounting hole 2 for opening the insert main body 1 to the end mill main body 11 of the blade-tip replaceable end mill is opened through in a direction perpendicular to the paper surface of Fig. 2 (vertical direction in Figs. 3 and 4).
In the present specification, of the pair of polygonal surfaces (front and back surfaces) of the insert body 1, the direction from one polygonal surface to the other polygonal surface and the other polygonal surface to one polygonal surface. The direction is generally referred to as the insert center line C direction. The insert center line C is the central axis of the insert body 1 that passes through the centers of the pair of polygonal surfaces. Further, a direction orthogonal to the insert center line C is referred to as an insert radial direction, and a direction around the insert center line C is referred to as an insert circumferential direction.

  Here, in this embodiment, the polygonal surfaces (the front and back surfaces that face the insert centerline C direction, that is, the front and back surfaces) of the insert body 1 are located at the center (front and back) of the mounting hole 2 as shown in FIG. They are arranged so as to be slightly twisted around the insert center line C extending in the thickness direction of the insert body 1 through the center of the polygonal surface. In addition, the insert body 1 of the present embodiment in the form of an equilateral triangle has a rotationally symmetric shape of 120 ° around the insert center line C, and the front and back equilateral triangle surfaces orthogonal to the insert center line C. The front and back are symmetrical with respect to three imaginary straight lines passing through the centers of the three side surfaces of the insert body 1 arranged around the periphery of the insert body 1.

  A rake face 3 is formed on the surface of the insert main body 1 facing the direction of the insert center line C, that is, on the front and back polygonal faces, and is disposed around these polygonal faces and orthogonal to the insert center line C. A relief surface 4 is formed on the side surface of the insert body 1 that faces the insert radial direction (direction substantially perpendicular to the insert center line C). Further, at the intersecting ridge line portion between the rake face 3 and the flank face 4, a main cutting edge 5 is formed at each side ridge portion of both polygonal surfaces, and a corner blade is provided at each corner portion of the polygonal surface. 6 is formed, and the corner blade 6 has a convex curve shape such as a 1/3 arc as seen from the direction facing the rake face 3 in the insert center line C direction. That is, the insert body 1 includes a main cutting edge 5 and a corner edge 6 as a cutting edge forming an intersecting ridge line portion between a polygonal surface and a side surface. In this embodiment, the main cutting edge 5 and the corner edge 6 are positioned on one plane perpendicular to the insert center line C in each of the front and back polygonal surfaces.

The rake face 3 formed on the front and back polygonal surfaces is such that the outer peripheral portions along the main cutting edge 5 and the corner edge 6 are spaced apart from the main cutting edge 5 and the corner edge 6 toward the inside of the polygonal face. The positive rake face 3a is inclined so as to recede in the direction of the insert center line C toward the opposite polygonal surface. That is, the rake face 3 is a positive rake face that recedes toward the center side in the direction of the insert center line C of the insert body 1 as it is separated from the main cutting edge 5 and the corner edge 6.
The periphery of the opening of the attachment hole 2 at the center of the polygonal surface is a flat constraining surface 3b perpendicular to the insert center line C.

Further, a protrusion 3d is formed around the opening of the mounting hole 2 on the polygonal constraining surface 3b on the front and back sides. The protrusions 3d have a substantially rectangular shape when viewed in the direction of the insert center line C, and are formed one by one on a straight line connecting the insert center line C and the corner blade 6 in each restraint surface 3b. Three protrusions 3d are formed at equal intervals in the circumferential direction with respect to 3b, and the protruding end surfaces of the three protrusions 3d in the direction of the insert center line C in this one restraint surface 3b are located on one plane perpendicular to the insert center line C. doing.
The main cutting edge 5 and the corner edge 6 may be formed with lands or round honing.
Moreover, in each figure, although the boundary line is shown for the positive rake face 3a, the flank 4 etc. for description, a boundary line does not necessarily appear.

In addition, the three side surfaces arranged around the triangular surfaces on the front and back sides of the insert body 1 have recesses recessed inward in the insert radial direction in the center portion of the insert body 1 in the direction of the insert center line C as shown in FIG. 7 is formed over the entire circumference of the insert body 1. The bottom surface 7b facing the outer peripheral side of the insert main body 1 (the outer side in the insert radial direction) of each of the concave portions 7 on the three side surfaces has an uneven hexagonal shape in a cross section perpendicular to the insert center line C. Each of the six surfaces connected to the side is parallel to the insert center line C and is a flat surface perpendicular to the pair of polygonal constraining surfaces 3b.
Further, the width of the recess 7 in the direction of the insert center line C is set to 1/3 or more of the thickness of the insert body 1 itself (the outer dimension of the insert body 1 along the direction of the insert center line C). The flank 4 of the corner blade 6 is formed on the outer side of each side surface in the direction of the insert center line C on the outer side of the insert body 1 (outside in the insert radial direction) with respect to the recess 7. Yes.

  Furthermore, in the cutting insert of this embodiment, as shown in FIG. 23, the main cutting edge 5 and the corner edge 6 used at the time of cutting are rotated counterclockwise when the blade end replaceable end mill is viewed from the front side. A right-handed cutting insert configured to form a right blade, and when viewed from the direction facing the polygonal surface on which the rake face 3 of the main cutting edge 5 and the corner edge 6 is formed, One end portion 6a of the corner blade 6 connected to the one end portion 5a of the main cutting blade 5 is positioned at one end portion 5a of the main cutting blade 5 positioned on the clockwise direction side of the circumference, and is positioned on the counterclockwise direction side. The other end portion 5b of the other corner blade 6 is connected to the other end portion 5b of the main cutting edge 5 to be connected. The other polygonal surface as viewed from one polygonal surface side is slightly twisted toward the clockwise direction as shown in FIG.

  The main cutting edge 5 connected to the corner blade 6 is connected to the one end portion 6a of the corner blade 6 as shown in FIG. 2 when viewed from the direction facing the rake face 3 when viewed in the direction of the insert center line C. The one end portion 5a of the cutting blade 5 has a convex curve shape having a radius of curvature larger than the convex curve formed by the corner blade 6, and the other end portion 5b of the main cutting blade 5 has a concave curve shape. That is, one end portion 5a of the main cutting edge 5 is a convex curved cutting edge, and the other end portion 5b of the main cutting edge 5 is a concave curved cutting edge. Here, the concavo-convex curve formed by these main cutting edges 5 is such that the radius of curvature of the concave curve formed by the other end portion 5b is larger than the radius of curvature of the convex curve formed by the one end portion 5a. The length of the convex curve formed by 5a is set to be longer than the length of the concave curve formed by the other end 5b.

  Accordingly, one main cutting edge 5 formed on one side ridge extending between two corners adjacent to each other in the circumferential direction of the polygonal surface is scooped. When viewed from the direction facing the surface 3, one of the two corners (the first corner. In the present embodiment that is a right-handed cutting insert, the one side ridge is clockwise. One end portion (first end portion) 5a of the main cutting edge 5 connected to the direction side corner portion is formed in a convex curve shape, and the other corner portion (second corner portion. The other end part (second end part) 5b of the main cutting edge 5 connected to the counterclockwise direction corner of the side ridge part has a concave curve shape.

  Since the insert body 1 has a rotationally symmetrical shape around the insert center line C by a predetermined angle (120 ° in this embodiment), in the cutting insert of this embodiment that is right-handed, the direction facing the rake face 3 When viewed from the above, the one corner portion with respect to one main cutting edge 5 is relative to the other main cutting edge 5 adjacent to the one main cutting edge 5 in the clockwise direction via the one corner portion. Is the other corner.

  Further, since the insert body 1 has a reverse inversion shape with respect to three imaginary straight lines passing through the centers of the side surfaces, the two flank surfaces 4 formed on one side surface of the insert body 1 and many front and back surfaces. Each of the two main cutting edges 5 formed at each of the intersecting ridge lines with the rake face 3 of the rectangular surface is also in an inverted symmetrical shape with respect to the polygonal surfaces on the front and back sides. That is, one polygonal surface of the pair of front and back polygonal surfaces of the insert body 1 is a first polygonal surface, the other polygonal surface is a second polygonal surface, and one side surface of the insert body 1 is The first flank 4 is defined as a first flank 4 which is the first flank 4 of the two flank 4 formed on the first side. The main cutting edge 5 formed at the crossing ridge line portion with the rake face (first rake face) 3 of the first polygonal surface is defined as the first main cutting edge 5, and the second multiple of the first side face. The flank 4 on the side of the square surface is used as a second flank 4, and the second flank 4 is formed at the crossing ridge line portion of the second polygonal rake face (second rake face) 3. When the main cutting edge 5 is the second main cutting edge 5, the insert body 1 is rotated 180 ° in the circumferential direction around the virtual straight line on the first side surface and reversed. The first main cutting edge 5 coincides with the second main cutting edge at the original position before reversing, and the second main cutting edge is at the original position before reversing. Therefore, the first and second main cutting edges 5 have a reverse symmetrical shape with respect to the first and second polygonal surfaces on the front and back sides.

  Therefore, in a total of two main cutting edges (first and second main cutting edges) 5 formed one by one on both sides in the insert center line C direction of one side face (first side face) of the insert body 1, The other end portion (second end portion) 5b of the other main cutting edge 5 is positioned on the opposite side of the one end portion (first end portion) 5a of one main cutting edge 5 in the direction of the insert center line C. One end portion (first end portion) 5a of the other main cutting edge 5 is positioned on the opposite side of the other end portion (second end portion) 5b of the main cutting edge 5 in the direction of the insert center line C. Moreover, also about the corner | angular part of the polygonal surface in which the corner blade 6 continuing to these two main cutting blades 5 is formed, one polygonal surface (first polygonal surface) and the other polygonal surface (second The other corners (second corners) are located on the opposite sides of the one corner (first corner) in the insert center line C direction on the polygonal surface.

  In the present embodiment, the convex curve formed by one end portion 5a of the main cutting edge 5 and the concave curve formed by the other end portion 5b are in contact with each other at the contact point 5c. One end portion 5a of the main cutting edge 5 and one end portion 6a of the corner blade 6 connected thereto, and the other end portion 5b of the main cutting blade 5 and the other end portion 6b of another corner blade 6 connected thereto are also in contact with each other. Yes. Therefore, the contact 5c is located on the other corner side from the midpoint of the side ridge part of the polygonal surface where the main cutting edge 5 is formed. In the present embodiment, a convex curve is formed from a contact point between the one end portion 5a of the main cutting edge 5 and one end portion 6a of the corner blade 6 connected thereto to a contact point 5c between the one end portion 5a and the other end portion 5b of the main cutting edge 5. A range of one end portion 5a of the main cutting edge 5 which is a cutting edge, from this contact point 5c to a contact point between the other end portion 5b of the main cutting edge 5 and the other end portion 6b of another corner blade 6 connected thereto. It is set as the range of the other end part 5b of the main cutting edge 5 made into the concave curvilinear cutting edge. Therefore, in this embodiment, the main cutting edge 5 and the corner edge 6 formed at the side ridges and corners of the polygonal surfaces on the front and back sides, which are the rake face 3, are drawn in a smoothly continuous concave-convex curve. Will do.

  In this way, the flank 4 connected to the main cutting edge 5 and the corner blade 6 is formed into an uneven curved surface, whereby the flank 4 on the front and back polygonal surfaces (regular triangle surface) side on the side surface of the insert body 1 is formed. The concave portion 7 formed in the shape of the concave portion 7 is formed in a polygonal line shape in which a cross section perpendicular to the insert center line C of the bottom surface 7b forms a convex V shape extending in a direction in which a portion along the main cutting edge 5 intersects an obtuse angle. In addition, the portions along the one end portion 5a and the other end portion 5b of the pair of main cutting blades 5 adjacent to each other via the corner blades 6 in the circumferential direction have a bent line shape that forms a convex V shape extending in a direction intersecting at an acute angle. It is formed in a partial hexagonal shape.

  As shown in FIGS. 1, 3, 4, and 5 to 19, the insert body 1 of the cutting insert according to the present embodiment is a pair of plate-like pieces made of green compacts having the same shape. It is formed by sintering the bodies 20 in a state where they are bonded together in the direction of the insert center line C of the insert body 1.

  In FIG. 9B, the bonded surface of the divided body 20 (the surface facing the other divided body 20 side along the insert center line C direction of one divided body 20 among the pair of divided bodies 20 to be bonded) 21. Is formed with an alignment portion 24 having a convex portion 22 and a concave portion 23 arranged adjacent to each other. Specifically, the convex portion 22 and the concave portion 23 of the alignment portion 24 are arranged adjacent to each other in the insert circumferential direction. In the illustrated example, the convex portion 22 and the concave portion 23 are arranged close to each other in the insert circumferential direction. Are formed so as to form continuous irregularities. In addition, the convex part 22 and the concave part 23 of the alignment part 24 may be spaced apart from each other in the insert circumferential direction, that is, there is a gap between the convex part 22 and the concave part 23. Also good. In addition, a plurality of alignment portions 24 having convex portions 22 and concave portions 23 arranged adjacent to each other in the insert circumferential direction are provided on the bonding surface 21, and these alignment portions 24 are arranged adjacent to each other in the insert circumferential direction. May be. In this case, the convex portions 22 and the concave portions 23 of the alignment portions 24 adjacent to each other in the insert circumferential direction are also disposed adjacent to each other, and the plurality of alignment portions 24 form an uneven shape that continues in the insert circumferential direction as a whole. become.

  In addition, a groove portion 25 is formed on the bonding surface 21 so as to extend from between the convex portion 22 and the concave portion 23 of the alignment portion 24 over the peripheral edge portion of the bonding surface 21. In addition, the groove part 25 should just extend over the peripheral part of the bonding surface 21 from any one of the convex part 22 and the recessed part 23 of the alignment part 24. In the example of illustration, the groove part 25 is the convex part 22 and From both of the recesses 23, it extends over the peripheral edge of the bonding surface 21.

In the present embodiment, a plurality of alignment portions 24 and groove portions 25 are formed on the bonding surface 21, and specifically, the alignment portions 24 and groove portions correspond to the number of corners of the insert body 1 having a triangular plate shape. Each of the alignment portions 24 and the groove portions 25 is formed by a virtual intersection (this book) between the insert center line C and the bottom surfaces 7b adjacent to (in contact with each other) across the corner portion of the divided body 20. In the embodiment, they are respectively arranged on a straight line connecting a portion corresponding to the corner blade 6).
That is, since the insert body 1 has an equilateral triangular plate shape (polygonal plate shape), the bonding surface 21 of the divided body 20 has an equilateral triangular surface shape (polygonal surface shape), and the alignment portion 24. And the number of the groove portions 25 are three corresponding to the number of corners of the bonding surface 21. Further, in the present embodiment, one of these alignment portions 24 is arranged corresponding to each corner of the bonding surface 21. Specifically, each alignment portion 24 includes the insert center line C and each corner center. Are located on three virtual straight lines connecting the two.

  In the example shown in FIG. 16, the convex portion 22 and the concave portion 23 of the alignment portion 24 are arranged adjacent to each other around the insert center line C. Further, the plurality of alignment portions 24 are arranged around the insert center line C at intervals. In the plan view shown in FIG. 16 (when the bonding surface 21 is viewed in front), these alignment portions 24 are virtual inscribed circles indicated by two-dot chain lines that are in contact with the center of each side of the outer peripheral edge of the bonding surface 21. Arranged inside. Further, in this plan view, the convex portion 22 and the concave portion 23 are both rectangular or semicircular.

  6 and 8, the convex portion 22 protrudes from the bonding surface 21 perpendicular to the insert center line C so as to be tapered toward the insert center line C direction of the divided body 20, and the convex portion 22. The top surface 22a is a plane perpendicular to the insert center line C. In addition, in the cross-sectional view parallel to the insert center line C shown in FIG. 12, the inclined surface 22b connected to the periphery of the top surface 22a of the convex portion 22 is inclined with respect to the taper angle (a surface perpendicular to the insert center line C). The angle α is set to 45 ° or less.

  6 and 8, the recess 23 is retracted (recessed) from the bonding surface 21 perpendicular to the insert center line C so as to be tapered toward the insert center line C direction of the divided body 20. The bottom surface 23a of the recess 23 is a plane perpendicular to the insert center line C. In addition, in the sectional view parallel to the insert center line C shown in FIG. 12, the inclined surface 23b connected to the periphery of the bottom surface 23a of the recess 23 has a taper angle (an angle inclined with respect to a surface perpendicular to the insert center line C). α is set to 45 ° or less.

  Specifically, the taper angle α on the inclined surface 22b of the convex portion 22 and the taper angle α on the inclined surface 23b of the concave portion 23 are set to the same value. In addition, the part which faces the adjacent recessed part 23 side among the inclined surfaces 22b of the convex part 22, and the part which faces the adjacent convex part 22 side among the inclined surfaces 23b of the recessed part 23 are formed on the same plane.

  And as shown in FIG. 6, in the state which the convex part 22 and the recessed part 23 in the alignment parts 24 which a pair of division body 20 opposes were fitted, the bonding surfaces 21 of these division bodies 20 are closely contacted ( The insert body 1 is formed. In FIG. 8, the protrusion amount from which the convex portion 22 protrudes from the bonding surface 21 is slightly smaller than the retraction amount in which the concave portion 23 retracts from the bonding surface 21. A gap is formed between the bottom surface 23a of 23. Thus, by providing a gap between the top surface 22a of the convex portion 22 and the bottom surface 23a of the concave portion 23, the adhesion between the abutting bonding surfaces 21 is ensured. Moreover, the inclined surface 22b of the convex part 22 fitted and the inclined surface 23b of the recessed part 23 are closely_contact | adhered without gap.

  In FIG. 16, on the insert center line C of the divided body 20, a through hole 26 that penetrates the divided body 20 in the direction of the insert center line C and constitutes the mounting hole 2 of the insert body 1 is formed. The through-hole 26 opens to the polygonal surface and the bonding surface 21. 16 and 17, the groove 25 extends on the bonding surface 21 from the alignment portion 24 to the inner peripheral edge portion of the insert body 1 (that is, the inner peripheral surface of the through hole 26).

In the present embodiment, the groove portion 25 extends along a radial direction (insert radial direction) orthogonal to the insert center line C, and the cross-sectional shape of the groove portion 25 is a concave circle as shown in FIGS. It has an arc shape. In FIG. 17, the end portion on the alignment portion 24 side of the groove portion 25 is formed so as to partially cut out the inner peripheral side (inner side in the insert radial direction) end portion of the convex portion 22 of the alignment portion 24. And it is opened in the recess 23. As a result, the groove 25 communicates with the alignment portion 24 and opens into the through hole 26.
In the illustrated example, the groove 25 is formed from the through hole 26 to the top surface 22 a of the convex portion 22, but does not reach the bottom surface 23 a of the concave portion 23. Even in such a configuration, when the divided bodies 20 are bonded to each other, the convex portion 22 and the concave portion 23 of the facing alignment portion 24 are fitted to each other. In this case, fluids such as the gas generated and the leaching binder component are discharged from the top surface 22a of the convex portion 22 fitted into the concave portion 23 to the outside of the insert through the groove portion 25 (in a communication passage 27 described later). ing.

  5 and 7, in a state where the pair of divided bodies 20 are bonded to each other, the groove portions 25 of the divided bodies 20 are arranged to face each other in the direction of the insert center line C, and the insert main body 1 is formed by the opposed groove portions 25. A communication passage 27 that communicates the alignment portion 24 with the outside of the insert body 1 is formed. In the present embodiment, the communication passage 27 of the insert body 1 is opened in the mounting hole 2. In FIG. 7, the cross-sectional shape of the communication passage 27 is formed in a flat hole shape such as a flat (short) flat elliptical hole shape, a rhomboid hole shape, or an oblong hole shape that is crushed (short) in the thickness direction of the insert body 1.

Next, a method for manufacturing the cutting insert of the present embodiment will be described.
This manufacturing method of a cutting insert includes a green compact forming process, a bonding process, a degreasing process, and a sintering process in this order.
In the green compact molding step, the divided body 20 is molded by die molding such as press molding, and the alignment portion 24 having the convex portion 22 and the concave portion 23 is formed on the bonding surface 21 of the divided body 20. .
In the bonding step, the bonding surfaces 21 of the divided bodies 20 are joined to each other in a state in which the convex portions 22 and the concave portions 23 of the facing alignment portions 24 of the divided bodies 20 to be bonded to each other are fitted. And stick together).
In the degreasing step, a molding aid such as an organic material contained in the bonded divided body 20 is degreased. The “molding aid” mentioned here is added for the purpose of facilitating molding of the divided body 20 in the green compact molding step.
In the sintering step, the bonded divided bodies 20 are sintered and integrated so as not to be separated.

Next, a blade edge replaceable end mill which is a blade edge replaceable cutting tool of this embodiment to which the cutting insert configured as described above is detachably attached will be described.
20 to 25, in the blade-tip-replaceable end mill, the end mill main body 11 that is the tool main body has a substantially cylindrical shape with the axis O as the center. The rear end side (upper side in FIGS. 21 and 22) of the end mill main body 11 is a cylindrical shank portion 12 and further on the front end side (lower side in FIGS. 21 and 22) than the shank portion 12. The blade portion 14 to which the cutting insert is attached is formed through the neck portion 13. Such a blade-tip replaceable end mill is usually fed in a direction perpendicular to the axis O while the shank portion 12 is gripped by the spindle of the machine tool and rotated around the axis O in the end mill rotation direction (tool rotation direction) T. Then, the workpiece is cut by the cutting insert of this embodiment attached to the blade portion 14.

  A plurality of (two in this embodiment) tip pockets 15 are formed in the blade portion 14 so as to open to the outer periphery of the tip end portion of the end mill body 11, and the end mill rotation direction T side of these tip pockets 15 is arranged on the blade portion 14. Insert mounting seats 16 to which cutting inserts are attached are respectively formed at the front end portions of the facing wall surfaces. The end mill body 11 has a coolant hole 11a drilled along the axis O from the rear end surface of the shank portion 12 toward the front end side. The coolant hole 11a branches into a plurality at the blade portion 14, Opened toward the insert mounting seat 16 on the wall surface of each chip pocket 15 facing the rear side in the end mill rotation direction T.

  The insert mounting seat 16 has a flat bottom surface 16a that is recessed from the wall surface of the tip pocket 15 toward the rear side in the end mill rotation direction T and faces the end mill rotation direction T, and extends from the bottom surface 16a toward the end mill rotation direction T. 11 is provided with a wall surface facing the inner peripheral side of the tip end 11 and a wall surface 16c facing the outer peripheral end side of the tip end. The bottom surface 16a has a size and shape that is slightly smaller than the constraining surface 3b at the center portion of the rake face 3 of the insert body 1, and a screw hole 16d is formed in the center portion of the bottom surface 16a perpendicularly to the bottom surface 16a. On the wall surface 16c facing the inner peripheral side and the wall surface 16c facing the tip outer peripheral side, a ridge 17 projecting inside the insert mounting seat 16 is formed so as to extend in the circumferential direction of the bottom surface 16a.

  And by screwing the clamp screw 18 inserted through the mounting hole 2 of the insert body 1 into the screw hole 16d, the cutting insert is pressed against the bottom surface 16a by the polygonal surface of the constraining surface 3b. The protruding end of the ridge portion 17 in which the bottom surface 7b on the polygonal surface side which is the seating surface of the concave portion 7 on the two side surfaces facing the wall surface 16c and the wall surface facing the inner peripheral side of the tip end is in contact as described above. It is pressed against the surface 17a and fixed and attached to the insert mounting seat 16.

  According to the cutting insert of the present embodiment and the manufacturing method thereof described above, the pair of divided bodies 20 made of a plate-shaped green compact are arranged in the direction of the insert center line C of the insert body 1 (the insert body 1 having a plate shape and When pasting in the thickness direction of the divided body 20, the convex portions 22 and the concave portions 23 of the facing alignment portions 24 formed on the pasting surface 21 of these divided bodies 20 are fitted to each other, thereby Positioning between the bonding surfaces 21 can be performed easily and accurately, and by this fitting, sliding movement between the bonding surfaces 21 of the divided body 20 at the time of sintering is restricted in all directions in the surface direction. Thereby, it becomes easy to prevent the generation | occurrence | production of the level | step difference etc. resulting from the position shift of the bonding surfaces 21 in the outer peripheral surface (bottom surface 7b of the recessed part 7) of the insert main body 1 after sintering, and the external appearance quality of a cutting insert improves. The position of the cutting edge of the cutting insert attached to the insert mounting seat 16 is also determined with high accuracy, and the machining quality of cutting using this cutting insert is enhanced.

  Moreover, the alignment part 24 of the bonding surface 21 has the convex part 22 and the recessed part 23 which adjoin the insert circumferential direction, and the polygonal surface which faces the insert centerline C direction of the insert main body 1 was made into the odd-numbered corner. It can be easily applied to various insert shapes such as an insert shape (that is, when the insert body 1 is a triangular plate shape as in the present embodiment, or other pentagonal plate shape or heptagonal plate shape). .

Specifically, for example, in the conventional configuration disclosed in Japanese Patent Laid-Open No. 5-285708, the protruding portions and the recessed portions are formed one by one on the bonding surface of the divided body. In the recess, when applied to cutting inserts that are not 180 ° rotationally symmetric with respect to the center of the polygonal surface (insert center line), such as the odd-numbered cutting inserts described above, bonding is performed when the divided bodies are bonded together. The possible orientation (the relative position in the circumferential direction around the insert center line C) is limited, and the manufacturing becomes complicated.
On the other hand, according to the present embodiment, even in the case of the odd-numbered corner cutting insert, for example, as described above, the alignment portion 24 is arranged corresponding to each corner (corner portion of the polygonal surface). The directions in which the bodies 20 can be pasted together are hardly limited, and the manufacture can be easily performed regardless of the insert shape.

In addition, the communication path 27 that connects the alignment portion 24 and the outside of the insert body 1 is formed in the insert body 1, so that the protrusion 22 and the recess 23 that are fitted to each other as shown in FIG. 8. Even when a slight gap (fitting clearance) is provided between them, fluids such as gas generated in the gap and exuded binder components during the degreasing process pass through the communication passage 27 of the insert body 1. In addition to being discharged to the outside, it is also prevented from expanding in the gap during the next sintering step, so that the phenomenon of lifting between the bonded surfaces 21 is prevented. Thereby, since the close contact state between the bonded surfaces 21 of the divided body 20 is maintained well during sintering, the insert body 1 is stably sintered with high rigidity and high quality.
Specifically, a molding aid such as an organic material added in a green compact molding process for molding the divided body 20 by die molding such as press molding is decomposed in a subsequent degreasing process to generate gas. In addition, the gas is not accumulated in the gap between the convex portion 22 and the concave portion 23 but is discharged from the communication path 27 to the outside of the insert and is also prevented from expanding in the gap in the next sintering step. The bonding state between the surfaces 21 is maintained well.

  Thus, according to this embodiment, it is easy to align the bonded surfaces 21 of the divided bodies 20 that are bonded to each other, and the bonded surfaces 21 are bonded to each other while the sliding movement of the divided bodies 20 is restricted during sintering. Are closely bonded to each other, and the insert body 1 is manufactured accurately and stably in a predetermined shape. Therefore, the cutting insert can be stably manufactured with high quality and high rigidity. Furthermore, it can be easily applied to various insert shapes and is easy to manufacture.

  The communication path 27 includes a groove portion 25 formed on the bonding surface 21, and the groove portion 25 extends from at least one of the convex portion 22 and the concave portion 23 of the alignment portion 24 to the peripheral portion of the bonding surface 21. It extends. Specifically, in the present embodiment, the groove portion 25 communicates with both the convex portion 22 and the concave portion 23 of the alignment portion 24, and extends from between the convex portion 22 and the concave portion 23 to the peripheral portion of the bonding surface 21. It extends. With this configuration, the communication path 27 can be easily formed, and the communication state in the groove portion 25 can be visually recognized until just before the divided bodies 20 are pasted together. It will be successful. Further, the groove portion 25 communicates with at least one of the convex portion 22 and the concave portion 23 of the alignment portion 24 and extends to the peripheral edge portion of the bonding surface 21, whereby one alignment portion 24 with which the groove portion 25 communicates. The concave portion 23 or the convex portion 22 of the other alignment portion 24 fitted to the convex portion 22 or the concave portion 23 is also communicated with the outside of the insert body 1 through this groove portion 25, that is, the communication passage 27 is formed by the groove portion 25. As a result, the above-described effects can be obtained. When the groove portion 25 communicates with only one of the convex portion 22 and the concave portion 23 of the alignment portion 24 and reaches the peripheral portion of the bonding surface 21, one communication passage 27 is formed by one groove portion 25. Will be.

Further, by forming the communication path 27 by the groove portion 25 of the bonding surface 21, from each cutting edge located on the outer peripheral edge of the front and back surfaces (a pair of polygonal surfaces) facing the direction of the insert center line C to the communication path 27. The distance between each of the two can be ensured, and the cutting load acting on the cutting blade during cutting can be prevented from being transmitted through the insert body 1 to the vicinity of the communication passage 27, so that the rigidity of the insert body 1 is secured.
Moreover, when the groove part 25 is extended over the peripheral part of the bonding surface 21 from between the convex part 22 and the recessed part 23 of the position alignment part 24 like this embodiment, a pair of bonding surface 21 bonded together. It is easy to make these inserts 25 communicate with each other by aligning the positions in the insert circumferential direction of the grooves 25. In this case, the two communication groove 27 is defined by the two grooves 25 facing each other. It is easy to secure a large cross-sectional area of the flow path in the communication path 27, and thus the operational effect of the communication path 27 described above can be obtained more stably.

  Furthermore, since the communication path 27 is opened in the mounting hole 2 of the insert body 1, the following effects are obtained. That is, since the communication path 27 is opened in the inner peripheral surface (mounting hole 2) of the insert body 1, the communication path 27 can be formed without exposing the outer peripheral surface (side surface) of the insert body 1, The appearance quality of the cutting insert can be kept good. Further, since the communication path 27 can be arranged at a large distance from the cutting blade (the main cutting edge 5 and the corner blade 6) that cuts into the work material in the cutting insert, a large cutting load acts on the communication path 27. The strength of the cutting insert is ensured.

  Moreover, since the bottom face 7b of the recessed part 7 which becomes a joining site | part of the bonding surfaces 21 and is exposed to the side surface of the insert main body 1 is a negative surface parallel to the insert center line C, the pair of divided bodies 20 are The strength at the joint portion of the bonded insert main body 1 is sufficiently secured.

  In the present embodiment, the cross-sectional shape of the communication passage 27 is not a simple circular hole shape or a regular polygonal hole shape, but is a flat hole shape that is crushed in the thickness direction of the insert body 1. Gas (fluid) can be easily and stably removed from the adjacent convex portions 22 and concave portions 23 around the insert center line C, and the rigidity of the insert body 1 is easily secured.

  The embodiments of the present invention have been described above. However, the configurations and combinations thereof in the above-described embodiments are examples, and the addition, omission, replacement, and others of the configurations are within the scope not departing from the gist of the present invention. Can be changed. Moreover, the cutting insert of this invention can be used also in blade-tip-exchange-type cutting tools other than a blade-tip-exchange-type end mill. Further, the present invention is not limited by the above-described embodiment.

In the above-described embodiment, the insert body 1 has a regular triangular plate shape, but other regular polygonal plate shapes, for example, cutting inserts having a square plate-like insert body, and polygons other than the regular polygon plate shape. The present invention can be applied to a cutting insert having a plate-shaped insert body and also to a disk-shaped cutting insert.
For example, when applied to a cutting insert having a square plate-like or rectangular plate-like insert body, it can be used to prevent interference between the cutting edge that is not used for cutting and its flank and the work material. Although the number of cutting edges is reduced, the main cutting edges 5 may be formed only on a pair of opposite sides of a square surface or a rectangular surface.

  In the above-described embodiment, a case has been described in which the present invention is applied to a right-handed cutting insert configured to form a right blade that can be rotated counterclockwise when the blade-tip replaceable end mill is viewed from the front side. When applied to a left-handed cutting insert that is a left blade that is rotated clockwise as viewed from the front side, the shape of the insert body is mirror-symmetrical with the insert body 1 of the above embodiment. However, in either case, one end 5a of the main cutting edge 5 used for cutting is disposed on the inner peripheral side of the tip of the end mill body 11, and the other end 5b is disposed on the outer peripheral side. One end portion 5a is formed in a convex curve shape, and the other end portion 5b is formed in a concave curve shape.

  In the above-described embodiment, the groove 25 of each divided body 20 constituting the communication passage 27 of the insert body 1 extends from the alignment portion 24 to the inner peripheral edge portion of the bonding surface 21. However, the present invention is not limited to this, and may extend from the alignment portion 24 to the outer peripheral edge portion (side surface of the insert body 1) of the bonding surface 21. In this case, for example, the present invention can be easily applied to a cutting insert in which the mounting hole 2 is not formed in the insert body 1.

In addition, the communication path 27 is configured such that the groove portions 25 of the pair of divided bodies 20 are arranged to face each other. However, the present invention is not limited thereto, and for example, only one of the pair of divided bodies 20 is provided. The groove portion 25 is formed, and the communication passage 27 may be formed by arranging the groove portion 25 so as to face the bonding surface 21 of the other divided body 20.
Further, instead of forming the communication passage 27 of the insert body 1 with the groove portion 25 exposed to the bonding surface 21, for example, a through hole that communicates with the alignment portion 24 and penetrates the divided body 20 and opens into a polygonal surface. It may be formed by. However, it is more preferable that the communication path 27 is formed by the groove portion 25 because the above-described effects can be obtained.

  Moreover, in the above-mentioned embodiment, although the alignment part 24 and the groove part 25 were arrange | positioned corresponding to each corner blade 6 (corner part) of the polygonal surface of the insert main body 1, it is limited to this. Instead, it may be arranged corresponding to each of the main cutting edges 5 (edges) on the polygonal surface of the insert body 1. However, when the alignment portion 24 and the groove portion 25 are arranged corresponding to each corner blade 6 of the insert body 1, the joint strength around the insert center line C between the bonded surfaces 21 is ensured as a whole stably. However, it is more preferable because the space for arranging the alignment portion 24 and the groove portion 25 can be easily secured.

  Moreover, in the above-mentioned embodiment, although the convex part 22 and the recessed part 23 of the alignment part 24 were arrange | positioned adjacent to the periphery of the insert centerline C, it is not limited to this, These The convex portion 22 and the concave portion 23 may be arranged adjacent to each other in the insert radial direction orthogonal to the insert center line C. Furthermore, the convex portion 22 and the concave portion 23 of the alignment portion 24 are inclined toward one of the insert circumferential directions in a direction in which the insert circumferential direction and the insert radial direction are combined (for example, toward the outer side of the insert radial direction). May be arranged adjacent to each other. However, since the convex portion 22 and the concave portion 23 of the alignment portion 24 are arranged adjacent to each other in the insert circumferential direction around the insert center line C, for example, it is possible to easily cope with the insert shape of an odd corner, More preferred.

  Further, in the above-described embodiment, the insert main body 1 is described as a pair of plate-like divided bodies 20 made of green compacts having the same shape and bonded in the direction of the insert center line C of the insert main body 1. However, the present invention is not limited to this. That is, the insert main body 1 may be formed by sintering a plurality of plate-like divided bodies made of green compacts in a state where the insert main body 1 is bonded in the direction of the insert center line C of the insert main body 1, for example, three or more. The plate-like divided bodies may be bonded together in the direction of the insert center line C and sintered. In this case, a pair of bonded surfaces 21 are formed on the front and back surfaces of the divided body in the inner divided body located at positions other than both ends in the insert center line C direction of the insert body 1. However, as in the above-described embodiment, when the insert body 1 is formed by bonding a pair of divided bodies 20 having the same shape, the divided bodies 20 can be formed with one type of green compact, Easy to manufacture.

1 Insert body 2 Mounting hole 11 End mill body (tool body)
16 Insert mounting seat 20 Divided body 21 Bonding surface 22 Convex part 23 Concave part 24 Positioning part 25 Groove part 26 Through hole (periphery part of the bonding surface)
27 Communication path C Insert center line

Claims (7)

A cutting insert that is detachably attached to an insert mounting seat formed on a tool body of a cutting edge exchangeable cutting tool,
Formed in the shape of a plate, on the front and back surfaces facing the insert centerline direction, on the side surface facing the insert radial direction that is arranged around these front and back surfaces and orthogonal to the insert centerline, and on the intersecting ridgeline part of these front and back surfaces And having an insert body that is symmetrical with the front and back reversed,
The insert body is formed by sintering a plurality of plate-like divided bodies made of green compact in a state where they are bonded together in the insert center line direction of the insert body,
A plurality of alignment portions having convex portions and concave portions adjacent to each other around the insert center line are formed on the bonding surface of the divided body,
Cutting in which the bonding surfaces of the divided bodies are joined to each other in a state where the convex portions and the concave portions of the alignment portions facing each other of the divided bodies to be bonded to each other are fitted. insert. A cutting insert that is detachably attached to an insert mounting seat formed on a tool body of a cutting edge exchangeable cutting tool,
Formed in the shape of a plate, on the front and back surfaces facing the insert centerline direction, on the side surface facing the insert radial direction that is arranged around these front and back surfaces and orthogonal to the insert centerline, and on the intersecting ridgeline part of these front and back surfaces And having an insert body that is symmetrical with the front and back reversed,
The insert body is formed by sintering a plurality of plate-like divided bodies made of green compact in a state where they are bonded together in the insert center line direction of the insert body,
An alignment portion having a convex portion and a concave portion is formed on the bonding surface of the divided body,
In a state in which the convex portions and the concave portions in the alignment portions facing each other of the divided bodies to be bonded to each other are fitted, the bonded surfaces of these divided bodies are joined together.
A cutting insert characterized in that a communication passage is formed in the insert body to communicate the alignment portion and the outside of the insert body. The cutting insert according to claim 2,
The communication path is composed of a groove formed in the bonding surface,
The groove insert extends from at least one of the convex portion and the concave portion of the alignment portion over a peripheral edge portion of the bonding surface. The cutting insert according to claim 2 or 3,
The insert body is formed with a mounting hole penetrating the insert body in the insert center line direction,
The cutting insert, wherein the communication path is opened in the mounting hole. The cutting insert according to any one of claims 1 to 4,
The insert body is formed by bonding a pair of the divided bodies having the same shape to each other. The cutting insert according to any one of claims 1 to 5,
The insert body has a polygonal plate shape, and the bonding surface of the divided body is a polygonal surface shape,
The number of the said alignment part respond | corresponds to the number of corners of the said bonding surface, The cutting insert characterized by the above-mentioned. A method for producing the cutting insert according to any one of claims 1 to 6,
A green compact molding step of forming the divided body by molding, and forming an alignment portion having a convex portion and a concave portion on a bonding surface of the divided body,
In a state where the convex portions and the concave portions in the alignment portions facing each other of the divided bodies to be bonded to each other are fitted together, a bonding step of joining the bonded surfaces of these divided bodies;
A degreasing step of degreasing the molding aid contained in the bonded divided body;
And a sintering step of sintering the bonded divided bodies together.

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