JP5664409B2 - Replaceable edge luffing end mill - Google Patents

Description

  The present invention relates to a cutting edge exchangeable luffing end mill used for rough machining of a work material, in which a cutting insert having a recess formed in a cutting blade is detachably attached to an insert mounting seat of an end mill body.

  As such a blade-tip-exchange-type roughing end mill, for example, in Patent Document 1, a substantially polygonal plate shape is formed, a rake face is provided on the upper surface, a flank face is provided on the side surface, and a cross ridge line portion between the rake face and the flank face is provided. The corner cutting edge of the rake face is formed with a corner R cutting edge continuous with the main cutting edge, and the main cutting edge is divided by at least one groove formed on the flank. A cutting insert comprising a main cutting edge is described as being detachably attached to an insert mounting seat formed on an end mill body.

  Usually, in such a blade-tip-exchangeable luffing end mill, a recess formed by opening the groove on the main cutting edge used for cutting between cutting inserts attached to the insert mounting seats adjacent to the end mill body in the circumferential direction. Is shifted along the rotation trajectory around the axis of the end mill body, and it is generated on the work surface of the work material while cutting the chips with a plurality of divided main cutting edges to reduce cutting resistance. In this case, uncut parts due to the recesses are not left.

JP 2006-289600 A

  By the way, the insert mounting seat of the end mill body to which the cutting insert of such a cutting edge exchangeable roughing end mill is attached has a substantially polygonal plate shape in which the cutting insert has a rake face on the upper surface and a flank face on the side surface as described above. When it is made, as shown in Patent Document 1, the bottom surface on which the lower surface of the cutting insert is seated facing the rotation direction of the end mill body, and the cutting blade on the side opposite to the cutting blade used for cutting And a wall surface against which the flank face is abutted.

  When a cutting edge formed on one side ridge portion of the substantially polygonal rake face is damaged, the cutting insert is rotated around the rake face and reattached to the insert mounting seat. The cutting edge formed on the other side ridge is used for cutting. In the cutting edge exchangeable roughing end mill described in Patent Document 1, the wall surface of the insert mounting seat is divided by the groove. It is designed to come into contact with the flank face connected to the blade, and if the flank face is greatly chipped due to chipping of the cutting blade, etc., or the flank face is deformed to protrude outward The cutting edge formed on the other side ridge by reattaching the cutting insert to the insert mounting seat, the flank portion cannot be reliably brought into contact with the wall surface of the insert mounting seat. No longer can be used.

  The present invention has been made under such a background, and one of the plurality of cutting blades thus formed with the recesses may be chipped or deformed in the flank portion of the cutting blade due to a defect or the like. However, an object of the present invention is to provide a cutting edge exchangeable roughing end mill that can reliably use other cutting edges.

In order to solve the above-described problems and achieve such an object, the present invention provides an insert mounting seat formed on an end mill body, and a concave groove is formed by a concave groove formed on a flank surface reaching a rake surface. A cutting insert provided with a plurality of cutting blades is detachably mounted, the insert mounting seat includes a bottom surface and a wall surface, and the wall surface is formed on the flank of the cutting insert which is uneven by the concave groove. depending, is formed to uneven when viewed from a direction opposite to the bottom surface, said cutting insert, said groove formed in said flank connecting to the cutting edge, to the wall surface of the insert attachment seat is brought into contact with is attached to the insert mounting seat in the abutment portion of the formed protrusions, the interval between the wall above flank except for the contact portion is opened this The features.

  In the edge-changing type roughing end mill constructed in this way, the recessed groove on the flank that forms a recess for cutting chips on the cutting blade of the cutting insert is inserted when the cutting blade is not used for cutting. By making contact with the convex portion formed on the wall surface of the seat, the cutting insert is restrained in the circumferential direction of the flank and attached to the insert mounting seat. And even if the cutting edge used for cutting has a chip or the like, and the flank connected to the cutting edge is chipped or deformed so as to protrude outward, the chipping or deformation is caused in this way. Therefore, even if the cutting insert is reattached so that the flank portion faces the wall surface of the insert mounting seat, it does not interfere with the contact of the convex portion with the concave groove.

  Therefore, according to the cutting edge exchangeable roughing end mill having the above-described configuration, by reattaching the cutting insert and bringing the concave groove into contact with the convex portion in this way, the cutting insert is restrained in the circumferential direction again and stably inserted. Attach to the mounting seat, you can reliably use all unused cutting blades among the above-mentioned cutting blades, while cutting while reducing cutting resistance by the recesses formed on these cutting blades, It becomes possible to use the cutting insert evenly and efficiently for cutting.

  Here, in the cutting insert, when a plurality of the concave grooves are formed on the flank face connected to one cutting blade, at least two of the concave grooves are formed on the wall surface of the insert mounting seat. By forming the plurality of convex portions that can come into contact with each other, the cutting insert can be more reliably restrained in the circumferential direction and stable attachment can be performed.

  Further, the wall surface of the insert mounting seat is formed with an auxiliary contact portion capable of contacting the flank of the cutting insert at at least one of the circumferential ends of the wall surface. The cutting insert can be further stably attached by the contact by the auxiliary contact portion and the contact of the convex portion with the concave groove.

Furthermore, when the cutting insert is pressed and fixed to the inner peripheral side of the rear end of the end mill main body, the wall surface of the insert mounting seat facing the flank on the rear end side of the end mill main body of the cutting insert. In this case, by forming an opposing backup surface with a clearance of 0.1 mm or less between the flank of the cutting insert, the convex portion may be worn while the cutting insert is repeatedly attached and detached. However, the flank of the cutting insert can be supported by the backup surface, and the cutting insert can be prevented from rattling.

  As described above, according to the present invention, even if the flank face that is continuous with the cutting edge is chipped or deformed due to a cutting edge defect or the like, the flank face is made to face the wall surface of the insert mounting seat. When re-installing the cutting insert, the cutting insert can be securely restrained in the circumferential direction of the flank by attaching the convex portion of the wall surface to the concave groove, and a plurality of cutting inserts are formed. It is possible to perform efficient cutting using the cutting blades evenly and effectively.

It is a perspective view of the front-end | tip part of the blade-tip-exchange-type roughing end mill which shows one Embodiment of this invention. It is a top view of the front-end | tip part shown in FIG. It is ZZ sectional drawing in FIG. It is an enlarged view of the A section in FIG. It is a perspective view of the end mill main body tip part in the state where the cutting insert was removed in the embodiment shown in FIG. It is a top view of the end mill main body shown in FIG. It is a side view of the end mill main body shown in FIG. It is a front view of the end mill main body shown in FIG. It is the (a) top view, (b) side view, and (c) front view of the cutting insert attached to embodiment shown in FIG. It is a perspective view of the front-end | tip part of the blade-tip-exchange-type roughing end mill which shows the modification of embodiment shown in FIG. It is a perspective view of the end mill main body tip part in the state where the cutting insert was removed in the modification shown in FIG. It is a top view of the end mill main body shown in FIG. It is a side view of the end mill main body shown in FIG. It is a front view of the end mill main body shown in FIG.

  FIGS. 1 to 4 show an edge-replaceable luffing end mill according to an embodiment of the present invention. FIGS. 5 to 8 show an end mill body 1 of the edge-replaceable roughing end mill. FIG. The cutting insert 10 attached to a blade-tip-exchange-type roughing end mill is shown.

  In the present embodiment, the end mill main body 1 is formed of a steel material or the like and has a substantially columnar shape centered on the axis O, and the tip portion shown in FIGS. 1 to 8 is a blade portion 2 to which a cutting insert 10 is attached. In addition, the rear end portion (not shown) is a shank portion, and this shank portion is attached to the main shaft of the machine tool and rotated in the end mill rotation direction T around the axis O, and sent out in a direction intersecting the axis O. The work material is roughly processed.

  A plurality of (three in the present embodiment) chip pockets 3 are formed at equal intervals in the circumferential direction on the outer periphery of the tip of the blade part 2, and the wall surfaces of these chip pockets 3 facing the end mill rotation direction T are formed on the wall. Each of the insert mounting seats 4 to which the cutting insert 10 is attached is formed. In other words, the present embodiment is a three-blade edge replacement type roughing end mill, and the cutting insert 10 is a blade edge replacement type radius end mill having a radius edge shape.

  The cutting insert 10 forming such a radius blade shape is provided with an insert body 11 formed of a hard material such as cemented carbide and having a vertically long plate shape as shown in FIG. One flat surface facing (the left-right direction in FIG. 9B and the up-down direction in FIG. 9C) is the rake face 12, and the side surface arranged around the rake face 12 is the flank 13. A cutting edge 14 is formed at the intersecting ridge line portion between the rake face 12 and the flank face 13.

  Since the cutting blade 14 has a radius blade shape as described above, the basic shape thereof is substantially 1 / as shown by a broken line in FIG. 9A in a plan view as viewed from the direction facing the rake face 12. Four arcuate corner blades 14a and outer peripheral blades 14b extending linearly in the longitudinal direction of the insert body 11 (vertical direction in FIGS. 9A and 9B) so as to contact one end of the corner blades 14a It consists of. In the present embodiment, the insert main body 11 is formed to be 180 ° rotationally symmetric in the circumferential direction of the flank 13, and thus there are two cutting blades 14 having such a basic shape, along the cutting blades 14 in the plan view. In the circumferential direction of the flank 13, it is formed 180 ° rotationally symmetric.

  Further, the cutting blade 14 has a convex curve shape that is convex in the thickness direction at the center of the corner blade 14a at the corner blade 14a as shown in FIGS. 9B and 9C. None, the corner blade 14a is formed so as to gradually retreat in the thickness direction from the one end side to the outer peripheral blade 14b as shown in FIG. 9B. Furthermore, the portion between the other end of the corner blade 14a of one of the two cutting blades 14 and the outer peripheral blade 14b of the other cutting blade 14 is the other end of the corner blade 14a in the thickness direction. When it sees from the direction which opposes the rake face 12 gradually from the direction toward the outer peripheral edge 14b, a chamfered portion 13a is formed on the flank face 13 so that the corner edge 14a and the outer peripheral edge 14b have an obtuse angle. To be crossed.

  Then, a concave groove 15 is formed in the flank 13 so as to extend in the thickness direction to reach the rake face 12, whereby the cutting edge 14 is recessed inside the rake face 12 in the plan view. A recess 16 is formed. Here, in the present embodiment, the groove 15 is formed such that a cross section perpendicular to the thickness direction forms a concave curved shape such as a concave arc, except for a portion intersecting the chamfered portion 13a. The rake face 12 is reached to form a recess 16, except that the boundary between the recess 16 and the cutting edge 14 having the basic shape described above forms a convex arc with a small radius. ing.

  Further, in the present embodiment, a plurality of (three in the present embodiment) concave portions 16 formed by the concave grooves 15 are provided in the circumferential direction of the flank 13 for one cutting blade 14 of each cutting insert. They are formed at equal intervals. Furthermore, in the present embodiment, the concave groove 15 is formed so as to reach the seating surface 17 of the insert body 11 that is perpendicular to the thickness direction on the side opposite to the rake face 12, and FIG. As shown in FIG. b), the cutting edge which is gradually widened on both sides in the circumferential direction of the flank 13 as it goes from the rake face 12 to the seating face 17 side. In contrast, the flank 13 of the flank 14 is formed so as to gradually become narrower on both sides in the circumferential direction of the flank 13 as it goes from the rake face 12 toward the seating face 17.

  Furthermore, in the cutting inserts 10 attached to the three insert mounting seats 4, the basic shape and dimensions of the cutting blade 4 are equal to each other, but the phase of these recesses 16 is shifted along the cutting blade 14. When the respective cutting inserts 10 are attached to the respective insert mounting seats 4 and the end mill body 1 is rotated around the axis O, the rotation trajectory of the cutting blade 14 left between the recesses 16 is obtained. It overlaps and exhibits the basic shape as described above.

  The cutting insert 10 is formed with two through holes 18 penetrating the insert body 11 in the thickness direction and opening in the rake face 12 and the seating face 17 so as to be aligned in the longitudinal direction. As will be described below, the cutting insert 10 is attached to the insert mounting seat 4 by screwing the clamp screws 5 inserted into the through holes 18 into the screw holes of the insert mounting seat 4. Further, the cutting insert 10 of this embodiment is inclined so that the flank 13 gradually recedes from the rake face 12 including the concave groove 15 toward the seating face 17, and the cutting edge 14 has a clearance angle in advance. It is a positive insert.

  The three insert mounting seats 4 of the end mill body 1 to which such a cutting insert 10 is attached are respectively retracted by one step from the wall surface of the tip pocket 3 facing the end mill rotation direction T to the rear side in the end mill rotation direction T. A flat bottom surface 4 a facing the rotation direction T and a wall surface 4 b extending between the bottom surface 4 a and the wall surface of the chip pocket 3 are provided as a recess that opens to the outer periphery of the tip end of the end mill body 1. . The bottom surface 4a is formed with two screw holes 4c into which the clamp screws 5 inserted through the through holes 18 of the cutting insert 10 are screwed so as to open side by side in the direction of the axis O.

  The cutting insert 10 attached to these insert mounting seats 4 has a ¼ arc shape in the above basic shape excluding the recess 16 so that one of the two cutting edges 14 is used for cutting. The corner blade 14a extends from the inner periphery of the end mill body 1 toward the outer periphery of the rear end, and the linear outer peripheral blade 14b connected to one end (rear end) of the corner blade 14a is viewed from the end mill rotation direction T side. Arranged to extend parallel to the axis O. A portion of the flank 13 that intersects the corner blade 14a and the outer peripheral blade 14b at an obtuse angle by the chamfered portion 13a is directed to the inner peripheral side of the end mill body 1 at both ends of the one cutting blade 14. Accordingly, it extends away from the processing surface of the work material toward the rear end side, and is not exclusively involved in cutting.

  In this way, the other cutting edge 14 opposite to the one cutting edge 14 used for cutting is the above-mentioned basic shape excluding the concave portion 16, and the linear outer peripheral edge 14 b from the front end side of the end mill body 1 is the rear end. After extending toward the rear side, the corner blade 14a extends from the rear end of the outer peripheral blade 14b so as to bend toward the outer peripheral side toward the rear end side. The surface 13 also extends in the same manner except for the groove 15.

  Accordingly, the wall surface 4b of the insert mounting seat 4 facing the flank 13 also has a basic shape from the front end surface of the end mill body 1 to the rear end side in the circumferential direction corresponding to the circumferential direction of the flank 13. After extending, it is formed to curve to the outer peripheral side and reach the outer peripheral surface. However, before reaching the outer peripheral surface of the end mill body 1, the wall surface 4 b has a distal end side toward the outer peripheral side so as to face the chamfered portion 13 a connected to the rear end of the outer peripheral blade 14 b of the one cutting blade 14. A bent portion 4d that is bent so as to face is formed.

  As shown in FIGS. 5 and 6, the wall surface 4b has a bottom surface 4a with respect to the basic shape according to the relief surface 13 which is uneven by the groove 15 of the cutting insert 10 attached to each insert mounting seat 4. Is formed on the flank 13 of the cutting insert 10 on the convex portion 6 of the wall surface 4b of the insert mounting seat 4 thus formed in a concavo-convex shape. The groove 15 is brought into contact with the hatched portion of the groove 15 in FIGS. 9B and 9C, and each cutting insert 10 is attached to the insert mounting seat 4.

  Here, the abutting portion 6a (a portion where the convex portion 6 is hatched in FIG. 5) that abuts the concave groove 15 of the convex portion 6 is formed in a portion of the convex portion 6 on the chip pocket 3 side, In accordance with the clearance angle given to the clearance surface 13 including the concave groove 15 of the positive type cutting insert 10 as described above, as shown in FIG. It has been. In the present embodiment, a plurality (three) of the concave grooves 15 are formed on the flank 13 of the cutting insert 10, whereas a plurality of (the same number is formed on the wall surface 4 b according to these concave grooves 15. All three (three) convex portions 6 are formed with contact portions 6a.

  Furthermore, in this embodiment, it goes to a front end side as it goes to an outer peripheral side in one edge part of the outer peripheral surface side among the both ends of the said circumference direction of this wall surface 4b from the front end surface of the end mill main body 1 to an outer peripheral surface. The bent portion 4d bent in this manner is also formed with an auxiliary contact portion 6b (a portion where the bent portion 4d is hatched in FIG. 5) so as to contact the flank 13 of the insert body 11. Therefore, the auxiliary contact portion 6b is brought into contact with the chamfered portion 13a among the flank surfaces 13 of the insert body 11 (the chamfered portion 13a is hatched in FIGS. 9B and 9C). Part.)

  The auxiliary contact portion 6b and the contact portion 6a on the tip surface side of the blade portion 2, which is the other end portion of the three convex portions 6 in the circumferential direction of the wall surface 4b, are the bent portion 4d. Are formed on the side of the intersection ridgeline between the outer peripheral surface of the blade portion 2 and the tip surface, and the area where the auxiliary contact portion 6b and the contact portion 6a contact the insert body 11 is formed. As shown in FIG. 9B and FIG. 9C, the area where the contact portions 6 a of the other two convex portions 6 are in contact with the concave grooves 15 is made smaller.

  On the other hand, the wall surface 4b including the portion on the bottom surface 4a side of the convex portion 6 excluding the contact portion 6a and the auxiliary contact portion 6b is formed to extend to the chip pocket 3 side perpendicular to the bottom surface 4a. In the state where the contact portion 6a is in contact with the concave groove 15 and the auxiliary contact portion 6b is in contact with the chamfered portion 13a as described above, the wall surface 4b portion perpendicular to the bottom surface 4a and the other cut of the insert body 11 are provided. A space is provided between the flank 13 connected to the blade 14. However, in this embodiment, the part facing the flank 13 connected to the corner blade 14a of the other cutting edge 14 that is not used for cutting the cutting insert 10 is 0.1 mm or less. Thus, the back-up surface 4e is described later.

  The cutting insert 10 is formed on the flank 13 such that the seating surface 17 is brought into close contact with the bottom surface 4a and the flank 13 connected to the other cutting edge 14 is directed toward the wall surface 4b. The concave groove 15 is abutted against the abutting part 6a of the convex part 6 and the chamfered part 13a is abutted against the auxiliary abutting part 6b and is seated, and the clamp screw 5 is inserted into the through hole 18 into the screw hole 4c. By being screwed, it is restrained in the circumferential direction of the flank 13 and attached. In this state, the through hole 18 is slightly with respect to the screw hole 4c in a state where the groove 15 and the chamfered portion 13a are in contact with the contact portion 6a and the auxiliary contact portion 6b and the cutting insert 10 is seated. The cutting insert 10 is pushed eccentrically and fixed to the inner peripheral side of the rear end of the end mill body 1 by screwing the clamp screw 5.

  Then, when roughing of the work material is performed by the edge-replaceable roughing end mill configured as described above, and a defect or the like is generated in the one cutting blade 14 used for cutting, along with the defect or the like, Even if the flank 13 of the cutting edge 14 used for cutting is largely chipped or deformed so as to protrude outward, the cutting edge 14 is cut to face the wall surface 4b side of the insert mounting seat 4. When the insert 10 is reattached and the other unused cutting edge 14 is used for cutting, the convex portion 6 of the wall surface 4b becomes a concave groove 15 of the flank 13 whose contact portion 6a is not used for cutting. Since they are in contact, chipping or deformation of the flank 13 does not affect the contact of the contact portion 6a with the concave groove 15.

  For this reason, according to the cutting edge exchangeable roughing end mill having the above-described configuration, even the cutting insert 10 in which a chip or the like is generated in this way can be reattached to the insert mounting seat 4 without impairing the seating stability of the insert body 11. It is possible to use the cutting insert 10 made of an expensive cemented carbide or the like efficiently for cutting by using all of the plurality of cutting blades 14 formed in the insert body 11 evenly and reliably. Moreover, as the cutting insert 10, since the thing for roughing end mills in which the recessed part 16 was formed in the cutting edge 14 by the said recessed groove 15 can be used as it is, it is further efficient.

  In the present embodiment, a plurality of (three) concave grooves 15 are formed on the flank 13 of one cutting edge 14 of the cutting insert 10, whereas this is also applied to the wall surface 4 b of the insert mounting seat 4. A plurality of (three) convex portions 6 are formed in accordance with each, and each is provided with a contact portion 6a. For example, a chip of the flank 13 due to a cutting edge defect or the like reaches one of the concave grooves 15. Even if it extends, the cutting insert 10 can be securely reattached to the insert mounting seat 4 and stably supported by the contact between the remaining concave groove 15 and the convex portion 6. However, in the present embodiment, the convex portion 6 of the insert mounting seat 4 is in contact with all the concave grooves 15 formed in the cutting insert 10 in this way. The convex part 6 may not be brought into contact with the concave groove 15 of the part.

  Furthermore, in this embodiment, the auxiliary | assistant which contact | abuts the said chamfer 13a of the flank 13 besides the contact part 6a of the convex part 6 contact | abutted to the concave groove 15 formed in the flank 13 of the cutting insert 10 in this way. The contact portion 6b is formed in the bent portion 4d, which is an end portion on the outer peripheral surface side of the blade portion 2 in the circumferential direction of the wall surface 4b of the insert mounting seat 4, and thus at least one of the circumferential directions of the wall surface 4b. Since the flank 13 is supported at the end, the cutting insert 10 can be attached to the insert mounting seat 4 more stably.

  Moreover, the chamfered portion 13a of the flank 13 is connected to a portion of the cutting edge 14 of the cutting insert 10 that intersects the corner blade 14a and the outer peripheral blade 14b at an obtuse angle and does not exclusively participate in cutting as described above. Since the cutting edge 14 is less likely to be chipped or deformed as in the case of the concave groove 15, the chamfered portion 13a can be reliably brought into contact with the auxiliary contact portion 6b when the cutting insert 10 is reattached.

  In the present embodiment, a convex portion 6 is formed on the intersecting ridge line portion with the tip surface of the blade portion 2, which is the other end portion in the circumferential direction of the wall surface 4b, and a contact portion 6a is provided. As a result, both end portions of the wall surface 4b are brought into contact with the flank 13 of the cutting insert 10. However, even when the convex portion 6 is not formed at the intersecting ridge line portion with the tip end surface of the blade portion 2 as described above, it is assisted. The abutting portion 6b is formed only on the bent portion 4d, or conversely, the bent portion 4d is not formed with the auxiliary abutting portion 6b, and is formed only on the side of the intersecting ridgeline with the blade 2 tip end surface of the wall surface 4b. In other words, the auxiliary contact portion 6b only needs to be formed at at least one end in the circumferential direction of the wall surface 4b.

  On the other hand, the clearance between the flank 13 of the insert main body 11 and the wall surface 4b of the insert mounting seat 4 other than the chamfered portion 13a and the concave groove 15 is provided as described above, and the flank due to a defect or the like. Even when deformation occurs so that 13 protrudes outward, the cutting insert 10 can be reattached while avoiding interference. However, among these, in this embodiment, the flank 13 connected to the corner blade 14a in the other cutting blade 14 that is not used for cutting the rear end side of the end mill body 1, and the backup surface 4e of the insert mounting seat 4 facing the flank 13a. The distance from the wall surface 4b to be made is as small as 0.1 mm or less.

However, while reattaching the cutting insert 10 and replacing the cutting insert 10 as described above, the contact portion 6a of the convex portion 6 in the insert mounting seat 4 of the end mill body 1 having a lower hardness than the insert body 11 is obtained. The auxiliary contact portion 6b is gradually worn, and the cutting insert 10 is easily displaced and the seating stability is impaired. In this embodiment, the screwing with the clamp screw 5 is performed as described above. Thus, the cutting insert 10 is pressed and fixed to the inner peripheral side of the rear end of the end mill body 1, and the backup surface 4e is opposed to the inner peripheral side of the rear end of the flank 13 connected to the corner blade 14a. Therefore, when the amount of displacement movement of the cutting insert 10 becomes larger than the distance between the backup surface 4e and the flank 13 The flank 13 is that the cutting insert 10 abuts against the backup surface 4e is supported. For this reason, according to this embodiment, even after the contact portion 6a and the auxiliary contact portion 6b are worn, the end mill body 1 can be used to some extent, and the end mill life can be extended. It becomes.

  In addition, the contact between the groove 15 and the contact portion 6a of the protrusion 6 is such that the cross section of the groove 15 perpendicular to the thickness direction of the insert body 11 has a concave curve shape such as a concave arc as described above. In the case where it is formed, the contact portion 6a is also formed in a cross section parallel to the bottom surface 4a of the insert mounting seat 4 so as to form a convex curve such as a convex arc having the same curvature radius as the concave curve. It is desirable to secure the contact area so that the entire groove 6a can be brought into contact with the concave groove 15. However, both the concave groove 15 and the contact portion 6a of the convex part 6 have the same radius of curvature with high accuracy. It is not easy to form. In addition, the above-described wear occurs in the abutting portion 6a. On the other hand, when the insert body 11 is formed of a sintered material such as cemented carbide as in the present embodiment, the groove 15 is always high. It is difficult to maintain molding accuracy.

  Therefore, in such a case, the cross section of the contact portion 6a is a convex curve having a smaller radius of curvature than the concave curve formed by the cross section of the groove 15, and the protruding end of the convex portion 6 in the contact portion 6a You may make it contact | abut to the ditch | groove 15, or conversely makes the cross section of the contact part 6a into the convex curve shape with a larger curvature radius than the concave curve which the cross section of the ditch | groove 15 makes | separated, and it separated from the protrusion of the convex part 6 The contact portion 6a may contact the recessed groove 15 at two points.

  Further, for example, when the concave groove 15 is formed in a trapezoidal shape with a concave cross section that gradually becomes narrower as the concave surface 15 is recessed from the flank 13 and the concave portion 16 formed in the cutting blade 14 is formed in a nick shape. Is a convex isosceles trapezoidal shape in which the cross section of the abutting portion 6a of the convex portion 6 becomes narrower as it protrudes from the wall surface 4b, provided that the width of the protruding end portion is larger than the width of the groove bottom of the concave groove 15, The crossing angle of the pair of oblique sides of the convex isosceles trapezoid of the contact part 6a is smaller than the intersection angle of the pair of oblique isosceles of the concave isosceles trapezoid of the concave groove 15, and the intersection ridgeline between the oblique side and the protruding end is rounded. For example, the abutting portion 6a may abut against the concave groove 15 at two points by the intersecting ridge line portion between the pair of oblique sides and the protruding end portion. Furthermore, the abutment portion 6a having an isosceles trapezoidal shape in cross section may be brought into contact with the concave groove 15 having a concave cross-sectional shape as described above at two points.

  Furthermore, in the present embodiment, the case where the present invention is applied to a roughing end mill that is a radius end mill of a blade edge exchange type has been described, but the basic shape of the cutting edge extends substantially parallel to the axis O when viewed from the end mill rotation direction T side. A blade-end-exchangeable square end mill having an outer peripheral blade and a bottom blade extending substantially perpendicular to the axis O, or a hemispherical cutting edge whose basic shape of the cutting edge is centered on the axis O in the rotation trajectory around the axis O It is also possible to apply the present invention to a replaceable ball end mill.

  In particular, the cutting edge 14 of the cutting insert 10 has a convex curved corner edge 14a and the like, and the basic shape of the flank 13 is the same as the blade end replaceable ball end mill or the radius end mill of this embodiment. Accordingly, in the case of having a convex curved portion that curves in the circumferential direction, the portion between the concave grooves 15 in the flank 13 is brought into contact with the wall surface 4b of the insert mounting seat 4 as in Patent Document 1. If the main body 11 is to be attached, the insert main body 11 may be displaced along the convex curved surface portion. Therefore, the convex portion 6 is brought into contact with the concave groove 15 of the flank 13 as in the present invention. It is effective to restrain the main body 11.

  By the way, in the said embodiment, as shown in FIG. 5 thru | or FIG. 8, the bottom face 4a of the insert mounting seat 4 is each insert edge in the opening edge to the blade part 2 outer peripheral surface of the end mill main body 1 on the opposite side to the wall surface 4b. The cutting insert 10 attached to the mounting seat 4 is formed so as to extend in a concavo-convex shape from the front end inner peripheral side to the rear end outer peripheral side of the end mill main body 1 so as to match the shape of the seating surface 17 in the insert main body 11 of the cutting insert 10. Yes. Accordingly, the end mill of the concave groove 15 formed on the flank 13 of the cutting edge 14 used for cutting as shown in FIGS. 1 to 3 also on the outer peripheral surface of the blade 2 connected to the opening edge. A concave groove is formed on the rear side in the rotational direction T.

  Therefore, according to such a blade-tip-exchange-type roughing end mill, the portion along the basic shape excluding the concave portion 16 of the cutting blade 14 on which the cutting load acts is surely supported on the rear side in the end mill rotation direction T immediately. Thus, the mounting rigidity of the cutting insert 10 can be improved, and the shading of the insert body 11 due to such a cutting load can be prevented, and stable cutting can be promoted. On the other hand, since the outer peripheral surface of the blade part 2 is formed with a concave groove that is continuous with the concave groove 15 of the insert body 11, the outer periphery of the blade part 2 is formed in the portion left uncut by the concave part 16 on the processing surface of the work material. The surface will not interfere.

  However, instead of forming a concave groove on the outer peripheral surface of the blade portion 2 in this way, the insert mounting seat 4 can be replaced with a blade edge replaceable roughing end mill according to the modified example of the embodiment shown in FIGS. 10 to 14. The bottom edge 4a of the blade portion 2 is formed in a single convex curve shape that connects the groove bottom of the groove 15 in the seating surface 17 of the insert body 11 without the opening edge to the outer peripheral surface of the blade portion 2 being uneven. The outer peripheral surface of the portion 2 may also be connected to the opening edge so as not to form a groove.

  In such a modified blade edge-type roughing end mill, since the seating area of the seating surface 17 on the bottom surface 4a is reduced with respect to the mounting rigidity of the cutting insert 10, the blade portion is inferior to the above embodiment. Since a large clear lath can be ensured between the outer peripheral surface of 2 and the work surface of the work material by the cutting blade 14, when the above-mentioned chipping occurs in the cutting blade 14 used for cutting, the insert It is possible to prevent the chip of the main body 11 from being bitten between the processing surface and the outer peripheral surface of the blade portion 2 so that the end mill main body 1 is damaged or the processing surface is greatly damaged. Moreover, the advantage that formation of the blade part 2 is easy compared with the said embodiment can also be acquired.

DESCRIPTION OF SYMBOLS 1 End mill main body 2 Blade part 4 Insert mounting seat 4a Bottom surface of insert mounting seat 4 4b Wall surface of insert mounting seat 4 4c Screw hole 4d Bending part of wall surface 4b 4e Backup surface 5 Clamp screw 6 Convex part 6a Contact part 6b Auxiliary contact Part 10 Cutting insert 11 Insert body 12 Rake face 13 Flank 13a Chamfer 14 Cutting edge 14a Corner blade 14b Peripheral edge 15 Groove 16 Recess 17 Seating surface 18 Through-hole O End mill body 1 axis T End mill rotation direction

Claims (4)

The insert mounting seat formed on the end mill body, the cutting insert groove formed on the flank with a plurality of cutting blades having a recess formed by reaching the rake face is mounted detachably, the The insert mounting seat includes a bottom surface and a wall surface, and the wall surface is formed so as to be uneven as viewed from a direction facing the bottom surface according to the clearance surface of the cutting insert which is uneven by the concave groove, cutting insert, the groove formed on the flank contiguous to the cutting edge, the mounting is brought into contact with the contact portion of the insert attachment seat protruding portion formed on the wall surface of the said insert seat In addition, the blade surface exchangeable roughing end mill is characterized in that the wall surface excluding the contact portion is spaced from the clearance surface .   The cutting insert has a plurality of concave grooves formed on the flank face connected to the one cutting edge, and the wall surface of the insert mounting seat can contact at least two of the concave grooves. The blade edge exchangeable roughing end mill according to claim 1, wherein a plurality of the convex portions are formed.   The wall surface of the insert mounting seat is formed with an auxiliary contact portion capable of contacting the flank of the cutting insert at at least one of the circumferential ends of the wall surface. The blade-tip-exchangeable roughing end mill according to claim 1 or 2, characterized in that The cutting insert is pressed and fixed to the inner peripheral side of the rear end of the end mill body, and the wall surface of the insert mounting seat facing the flank on the rear end side of the end mill body of the cutting insert The cutting edge according to any one of claims 1 to 3, wherein a backup surface facing the flank of the insert is formed with an interval of 0.1 mm or less. Exchangeable roughing end mill.

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