JP2006239830A - Insert connecting and disconnecting type end mill and insert - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insert connecting and disconnecting type end mill capable of certainly using another cutting blade by preventing extension of a defect to the cutting blade of an insert even when a cutting blade used for cutting work is defective in cutting work and the insert used for this insert connecting and disconnecting type end mill. <P>SOLUTION: This insert connecting and disconnecting type end mill is constituted by arranging a plurality of the inserts 11 having the cutting blades 17 on an outer periphery of a roughly columnar end mill main body to be axially rotated so that an axially rotating locus continues toward the base end side from a head end of the end mill main body, and the insert 11 constitutes its characteristic feature that its outline is formed roughly in a polygonal flat plate type, the cutting blade 17 is provided on a polygonal side ridge part and a corner part 23 inclined to the inside against the side ridge part is provided on each of polygonal corner parts and that a recessed part 22 depressed to the inside of the insert 11 is formed on the corner part 23. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to, for example, an insert detachable end mill for wall surface rough machining used when machining a press die used for manufacturing a body of an automobile, and an insert used therefor.

  As a long edge type end mill for performing this kind of processing, a solid end mill integrally formed with a high speed steel is used. Such a solid end mill cuts the wall surface of the workpiece with a cutting edge provided toward the outer periphery of the end mill. If a part of the cutting edge is lost during cutting, the solid end mill is solid. Since the end mill itself cannot be used, it is necessary to excessively reduce the feed rate and feed speed of the end mill so that the cutting edge is not damaged, that is, the load on the cutting edge is reduced, resulting in poor machining efficiency. There was a problem.

  Therefore, Patent Literature 1 and Patent Literature 2 propose an insert detachable end mill having a plurality of inserts having cutting edges. In these insert detachable end mills, the outer periphery of the substantially cylindrical end mill main body includes a plurality of cutting blades whose rotation trajectory around the axis of the cylinder continues from the distal end side to the proximal end side of the end mill main body. Inserts are arranged.

  In the above insert detachable end mill, the inserts are arranged so that the rotation trajectory of the cutting edge is continuous from the distal end side to the proximal end side of the end mill body, so that a plurality of inserts from the distal end side to the proximal end side of the end mill body are arranged. Wall surface processing can be performed with this cutting blade. That is, a long blade type is formed by a plurality of inserts. Here, if some of the cutting blades of multiple inserts are missing, only this missing insert needs to be replaced, so the feed rate and feed amount of the end mill can be increased appropriately, Efficiency can be improved.

In addition, the insert used in the insert detachable end mill of Patent Document 2 has a polygonal flat plate shape, for example, a quadrangular flat plate shape, and a cutting edge is provided on a side ridge portion of the quadrilateral, The four cutting blades can be used sequentially, and the usage cost of the insert can be reduced.
JP-A-9-136207 JP-A-10-113812

However, in the insert detachable end mill proposed in Patent Document 2, cutting resistance is applied to the cutting edge formed on the side ridge portion of the insert, and the defect of this one cutting blade is adjacent via the corner portion. When it propagates to other cutting blades, the cutting blades formed at the two side ridges intersecting this corner are damaged, and two of the four cutting blades cannot be used. There was a problem. Since the insert cutting blade cannot be used stably in this way, at the site where these insert detachable end mills are used, the insert must be used when one or two of the four cutting blades of the insert are used. It is in a state of being discarded.
Therefore, there is no merit of using an insert having a plurality of cutting blades, and there is a problem that the cost of using the insert becomes high and the environmental load due to the disposal of the insert increases.

  The present invention has been made in view of the above circumstances, and even when a cutting edge used for cutting is lost during cutting, the extension of the insert to another cutting edge is increased. It is an object of the present invention to provide an insert detachable end mill that can prevent and use other cutting blades reliably, and an insert used in the insert detachable end mill.

  In order to solve the above-mentioned problems, the present invention provides an insert having a cutting edge on the outer periphery of a substantially cylindrical end mill body rotated around an axis, and the rotation locus of the cutting edge around the axis is A plurality of insert detachable end mills arranged so as to be continuous from the distal end toward the proximal end side, wherein the insert has a substantially polygonal flat plate shape, and the polygonal side ridge portion includes the A cutting edge is provided, and each corner portion of the polygon is provided with a corner portion inclined inward of the polygon with respect to the side ridge portion, and the corner portion is provided with a recess inside the insert. A concave portion is formed.

  In the above insert detachable end mill, a concave portion is formed in the corner portion, and this cutting edge is lost due to cutting resistance when cutting the workpiece with the cutting edge directed to the outer peripheral side of the end mill body. Even in this case, the propagation of the defect remains up to the recess, and the enlargement of the defect of the cutting edge is prevented, so that it is possible to prevent the other cutting edge on the opposite side of the recess from being lost. Therefore, even when one cutting edge of the insert is broken due to cutting resistance, it is possible to prevent the chip from expanding to the other cutting edge, and it is possible to use the cutting edge provided on each edge of the insert reliably. Therefore, the lifetime of the insert can be improved, the cost of using the insert can be reduced, and the environmental load due to the disposal of the insert can be reduced.

  Further, an R blade extending continuously from the side ridge portion is formed in the corner portion, and the concave portion is formed at an intersecting portion of the two R blades continuing to the two side ridge portions intersecting at the corner portion. By this, while ensuring the intensity | strength of a corner part, the expansion of the defect | deletion of a cutting blade can be prevented more reliably by the recessed part formed in the cross | intersection part of R blade. Moreover, since the R blade is formed, the machined surface of the material to be cut can be satisfactorily finished when cutting with the cutting blade of this insert.

  Further, when the maximum cutting amount of the cutting edge at the corner portion is S and the vertical distance from the side ridge portion to the concave portion is R, the corner portion is formed to have a relationship of S ≦ R. Thus, even when cutting with the maximum cutting amount S, the material to be cut does not come into contact with the recess, and the R blade connected to the cutting blade adjacent to the cutting blade used for cutting may be used for cutting. Therefore, it is possible to more reliably prevent the cutting edge from expanding.

  Moreover, when the cutting blade cuts into the workpiece by the serration formed so as to intersect the cutting blade, the cutting blade is cut into the workpiece at the same time as the entire length of the cutting blade. Since it does not contact, cutting resistance can be reduced. Moreover, since the chip | tip produced | generated from a to-be-cut material can be fractured | ruptured and can be made small, it becomes easy to discharge | emit chip | tip outside and can cut favorably.

  As described above, according to the present invention, even when the cutting edge used for cutting is lost during cutting, the extension of the insert to the other cutting edge is prevented, It is possible to provide an insert detachable end mill capable of reliably using a blade and an insert used in the insert detachable end mill.

Embodiments of the present invention will be described with reference to the drawings. 1 to 3 show an insert to be attached to an insert detachable end mill according to an embodiment of the present invention, and FIGS. 4 and 5 show an insert detachable end mill 1.
The insert detachable end mill 1 includes an end mill body 2 formed of steel or the like and an insert 11 formed of a hard material such as cemented carbide.

  As shown in FIG. 4, the outer shape of the end mill main body 2 is formed in a substantially cylindrical shape, and a large diameter portion 3 having a large diameter is formed on the rear end side (upper side in FIG. 4) of the end mill main body 2. A long blade type forming portion 4 is provided on the distal end side (lower side in FIG. 4) of the large diameter portion 3. On the outer peripheral surface of the long blade mold forming portion 4, there is a spiral groove that faces the rear side in the end mill rotation direction (counterclockwise direction in FIG. 5) from the front end side to the rear end side of the end mill body 2. As shown in FIG. 5, a plurality (four in the present embodiment) are formed at equal intervals in the circumferential direction, and this groove forms a chip pocket 5.

  A plurality of insert mounting seats 6 are spirally stepped in the direction toward the front end side of the end mill body 2 from the front end side to the rear end side of the tip pocket 5 toward the front side in the end mill rotation direction. In this embodiment, eight are formed as shown in FIG. Here, in this embodiment, the insert mounting seat 6 is formed so as to have the same arrangement in the pair of chip pockets 5A and 5A located on opposite sides of the rotation axis O of the end mill body 2. That is, the pair of chip pockets 5A and 5A are formed so as to be 180 ° rotationally symmetrical with respect to the center of the rotation axis O in an arbitrary cross section perpendicular to the rotation axis O. Further, the other pair of chip pockets 5B and 5B are also formed so as to be rotationally symmetrical with each other by 180 ° about the rotation axis O in any cross section perpendicular to the rotation axis O.

  Here, in the present embodiment, of the insert mounting seats 6A provided in the pair of chip pockets 5A, the insert mounting seat 6Aa located closest to the tip end side of the end mill body 2 is located on the tip surface 2A of the end mill body 2. The other insert mounting seats 6A are provided at equal intervals from the insert mounting seat 6Aa located on the most distal end side of the end mill body 2 at a predetermined interval. On the other hand, the insert mounting seat 6B provided in the other pair of chip pockets 5B is positioned between the insert mounting seat 6A and the insert mounting seat 6A of the pair of chip pockets 5A in the direction along the rotation axis O. It is formed to do.

  The wall surface facing the front side in the end mill rotation direction of the insert mounting seat 6 is positioned substantially perpendicular to the end mill rotation direction as shown in FIG. 4 is inclined with respect to the rotation axis O so as to recede toward the rear end side of the end mill body 2 as shown in FIG. And the screw hole 8 in which the clamp screw 30 which fixes the insert 11 is screwed in is formed in the wall surface which faces this rotation direction in the end mill.

  On the other hand, as shown in FIG. 1, the insert 11 used in the present embodiment is formed in a substantially square flat plate shape, and includes a top surface portion 12 that is a rake surface and a bottom surface portion that is a seating surface. And four side surface portions 14 serving as flank surfaces. The four side surface portions 14 are provided so as to be gradually inclined outward from the bottom surface portion toward the upper surface portion 12, and the insert 11 is formed in a substantially isosceles trapezoidal shape when viewed from the side, and has a clearance angle on the side surface portion 14. The positive insert 11 is marked with.

An insertion hole 15 through which a clamp screw 30 for fixing the insert 11 to the insert mounting seat 6 is inserted is formed in the center portion of the upper surface portion 12 so as to penetrate in a direction perpendicular to the upper surface portion 12 and the bottom surface portion. A flat surface 16 is formed around the insertion hole 15 of the upper surface portion 12 and is substantially the same shape as the square formed by the upper surface portion 12 and has a small size.
Further, the insert 11 is 90 ° rotationally symmetric with respect to the center line of the insertion hole 15, and is also formed symmetrically with respect to a plane passing through the midpoints of two side ridges.

  A cutting edge 17 is provided at a side ridge portion of the upper surface portion 12 that forms a square (a cross ridge line portion between the upper surface portion 12 and the side surface portion 14), and is formed in the vicinity of the cutting edge 17, that is, in the upper surface portion 12. Around the flat surface 16 is formed serrations in which a plurality of valleys 18 and peaks 19 are alternately arranged at substantially equal intervals. The plurality of valleys 18 and the peaks 19 constituting the serration are each formed by a smooth curved surface and are smoothly connected to each other. Further, the plurality of valleys 18 and the peaks 19 in this serration are the upper surface portion. By extending parallel to the bottom surface portion in a direction orthogonal to the cutting edge 17 formed on the 12 side ridges and intersecting the side surface portion 14, the cutting blade 17 has a smooth overall length in side view. As shown in FIG. 2, the side surface 14 is provided with a relief angle so that the side surface 14 has a gentle waveform as shown in FIG. ing.

  And, as shown in FIG. 2 and FIG. 3, each of the square corners formed by the upper surface portion 12 is provided with R blades 21 that are continuous from the cutting blades 17 formed on the respective side ridge portions, that is, A pair of R blades 21 are provided at the corners, and concave portions 22 having a concave curved shape that are smoothly connected to the respective R blades 21 are formed at intersections of the pair of R blades 21. The pair of R blades 21 and the recess 22 constitute a corner portion 23.

Here, the vertical distance R from the side ridge where the cutting edge 17 is provided to the recess 22 is larger than the maximum cutting amount S of the cutting edge 17 of the insert 11 as shown in FIG. Is formed.
Further, the R blade 21 is formed in a curved shape so as to be smoothly connected to a waveform formed by a plurality of peak portions 19 and valley portions 18 intersecting the cutting blade 17 in a side view. The central part of the arc formed is formed so as to be at the same height as the apex of the peak 19 of the serration.

  The insert 11 is abutted against the wall surface of the insert mounting seat 6 facing the end mill rotation direction with the bottom surface portion as a seating surface, and the clamp screw 30 is inserted into the insertion hole 15 of the insert 11 so that the screw of the insert mounting seat 6 is inserted. By being screwed into the hole 8, the insert mounting seat 6 is mounted. At this time, as shown in FIG. 5, the cutting blades 17b positioned on the outer peripheral side of the end mill of the inserts 11 mounted on the plurality of insert mounting seats 6 are positioned on substantially the same circumference, that is, in bottom view. The rotation trajectory drawn by the cutting edge 17b of each insert 11 is arranged so as to substantially coincide.

  The cutting edge 17a on the end mill tip side of the insert 11Aa mounted on the insert mounting seat 6Aa located closest to the tip side of the end mill body 2 among the insert mounting seats 6A provided in the pair of chip pockets 5A is shown in FIG. As shown in Fig. 4, the insert 11Aa is mounted in a state of slightly protruding with respect to the tip surface 2A of the end mill main body 2. The insert 11Aa has a cutting edge 17a protruding toward the tip side and a cutting point directed toward the outer periphery of the end mill. The blade 17b is used for cutting the workpiece.

  The insert mounting seats 6A provided in the pair of chip pockets 5A are provided at equal intervals with a predetermined interval, and the insert mounting seats 6B provided in the other pair of chip pockets 5B are rotated. The cutting edge of the insert 11 which is formed so as to be positioned between the insert mounting seat 6A and the insert mounting seat 6A of the pair of chip pockets 5A in the direction along the axis O, and which is mounted on the insert mounting seat 6 A long blade mold is formed in the long blade mold forming portion 4 of the end mill body 2 by 17b.

  In the insert detachable end mill 1, the end mill body 2 is attached to the long blade mold forming portion 4 at the tip of the end mill body 2 by being rotated around the rotation axis O and fed in a direction crossing the rotation axis O direction. Further, the cutting material 17 is cut by the cutting edges 17 of the plurality of inserts 11, and a finished surface is formed on the cutting material.

In the insert detachable end mill 1 having the above-described configuration, the mounted insert 11 has a substantially square plate shape, and a cutting edge 17 is provided on the side ridge portion of the square, and the square corner portion includes: A pair of R blades 21 are provided so as to continue to the two cutting blades 17, and a recess 22 is provided at the intersection of the pair of R blades 21, so that one cutting blade 17 b of the insert 11 is placed on the outer peripheral side of the end mill. Even when the cutting edge 17b is lost due to the cutting resistance when the workpiece is cut in, the recess 22 provided in the corner portion 23 can prevent the enlargement of the damage to the other cutting edges 17. it can.
Therefore, all the cutting edges 17 formed on the four side ridges of the insert 11 can be used, the cost of using the insert 11 can be reduced, the amount of disposal of the insert 11 can be reduced, and the environmental load is greatly reduced. be able to.

  In addition, a pair of R blades 21 extending from the cutting edge 17 are formed in the corner portion 23, and a recess 22 is formed at the intersection of the pair of R blades 21, so that the strength of the corner portion 23 can be ensured. At the same time, it is possible to more reliably prevent the cutting blade 17 from expanding. In addition, since the R blade 21 is formed, when the insert detachable end mill 1 is used for cutting, the processed surface formed on the workpiece can be finished well.

  Further, since the vertical distance R from the side ridge portion where the cutting edge 17 is provided to the recess 22 is formed to be larger than the maximum cutting amount S of the cutting edge 17 of the insert 11, When the material is cut, the recess 22 does not come into contact with the material to be cut, that is, the cutting force is not directly received by the recess 22, so that the cutting edge 17 can be prevented from being lost, and the insert 11 can be stabilized. Can be used.

Moreover, since the peak part 19 and the trough part 18 are formed so that it may cross | intersect the cutting edge 17 of the insert 11, and the cutting edge 17 is formed in the waveform in side view and top view, the cutting edge 17 is to be cut. When cutting into the material, the entire cutting edge 17 does not come into contact with the material to be cut at a time and the cutting resistance can be reduced, so that the rigidity of the end mill body 2 can be increased by ensuring the size of the tip pocket 5. Even when this is difficult, chattering of the insert detachable end mill 1 can be prevented. Furthermore, since the cutting edge 17 is formed in a wave shape, the chips generated from the workpiece can be easily broken and discharged, so the size of the chip pocket 5 for chip discharge is reduced. Thus, the rigidity of the end mill body 2 can be increased, and chattering of the insert detachable end mill 1 can be prevented.
Therefore, the processing accuracy of the insert detachable end mill 1 can be improved, and the insert 11 can be used more stably by preventing the insert 11 from being lost due to chatter.

  In this embodiment, the cutting edge 17 of the insert 11 is described as having a wave shape. However, as shown in FIGS. 6 and 7, the upper surface portion 12 of the insert 11 is smooth and the cutting edge 17 is linear. It may be a thing. However, in this case, it becomes impossible to obtain the effect of promoting chip discharge due to the above-described chip breakage, and it is necessary to enlarge the tip pocket 5 of the end mill body 2, so as in this embodiment, It is preferable to use a corrugated cutting blade 17 of the insert 11.

  Further, the shape of the insert 11 has been described as having an outer shape of a square flat plate, but the shape is not limited to this, and for example, an equilateral triangular flat plate or a parallelogram flat plate may be used. The outer shape is a polygonal flat plate shape, and the cutting edge 17 is provided at the side ridge portion of the polygon, and the corner portion 23 provided with the recess 22 is formed at the corner portion of the polygon. Anything is fine.

  In addition, a pair of R blades 21 are provided in the corner portion 23 so as to be continuous from the cutting blade 17, and concave concave portions 22 that are smoothly connected to the respective R blades 21 are formed at intersections of the pair of R blades 21. However, the present invention is not limited to this. For example, the corner portion 23 is provided with a linear corner blade so as to connect the two cutting blades 17, and the insert 11 is provided at the center portion of the corner blade. It is also possible to form a recess recessed inside.

  Moreover, although the four chip pockets 5 formed in the end mill body 2 have been described, the present invention is not limited to this, and any number of chip pockets 5 may be used. However, if there are too many chip pockets 5, the size of the chip pocket 5 becomes small and chip discharge becomes difficult, and if the size of the chip pocket 5 is secured, the rigidity of the end mill body 2 is insufficient. It is preferable to determine in consideration of the chip shape of the workpiece.

It is a perspective view of an insert which is an embodiment of the present invention. It is a top view of an insert which is an embodiment of the present invention. It is a corner | angular part enlarged view of the insert which is embodiment of this invention. It is a side view of the insert detachable end mill which is an embodiment of the present invention. It is a front view of the insert detachable end mill which is an embodiment of the present invention. It is a top view of an insert which is other embodiments of the present invention. It is a side view of the insert which is other embodiment of this invention.

Explanation of symbols

1 Insert Removable End Mill 2 End Mill Body 11 Insert 17 Cutting Blade 21 R Blade 22 Recess 23 Corner

Claims (5)

An insert having a cutting edge on the outer periphery of a substantially cylindrical end mill body rotated about an axis so that the rotation trajectory of the cutting edge about the axis continues from the distal end of the end mill body toward the base end side. It is an insert detachable end mill that is arranged in plural,
The insert has a substantially polygonal flat plate shape, the cutting edge is provided at a side ridge portion of the polygon, and the polygon is formed at each corner of the polygon with respect to the side ridge portion. In addition to being provided with an inclined corner on the inside,
An insert detachable end mill, wherein the corner portion is formed with a recess recessed inside the insert. In the insert detachable end mill according to claim 1,
The corner portion is formed with an R blade extending continuously from the side ridge portion, and the concave portion is formed at an intersection of the two R blades continuous with the two side ridge portions intersecting at the corner portion. An insert detachable end mill characterized by that. In the insert detachable end mill according to claim 1 or 2,
An insert detachable end mill having a relationship of S ≦ R, where S is the maximum cutting amount of the cutting edge at the corner and R is the vertical distance from the side ridge to the recess. . In the insert detachable end mill according to claim 1,
The insert detachable end mill, wherein the cutting blade has a wave shape by serrations formed so as to intersect the cutting blade. An insert attached to the insert detachable end mill according to claim 1,
The outer shape is a substantially polygonal flat plate shape, the cutting edge is provided at a side ridge portion of the polygon, and each corner portion of the polygon is inclined inward of the polygon with respect to the side ridge portion. A corner is provided,
The corner portion is formed with a recess recessed inside the insert.

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