JP5482190B2 - Blade-replaceable rotary tool - Google Patents

Description

  The present invention relates to a blade-tip-replaceable rotary tool such as a face mill in which a cutting insert is detachably attached by an attachment screw.

  As a blade-tip-exchange-type rotary tool, for example, Patent Document 1 discloses a plurality of polygonal flat plate-shaped cutting inserts having a cutting edge on the outer periphery of the tip of a disk-shaped tool body and having a mounting hole formed through the center. Attached in a circumferential manner with a mounting screw so as to be detachable, a polygonal base corresponding to the outer shape of the cutting insert is provided at the bottom of the tool body, and a cutting insert is mounted on the front of the base in the rotational direction. The thing of the structure provided with the insert attaching part for doing is proposed.

International Publication No. 2008/120186 Pamphlet

By the way, the insert mounting portion of the above-described blade-tip-exchange-type rotary tool has a bottom surface on which the seating surface of the cutting insert comes into contact with the outer periphery of the screw hole into which the mounting screw is screwed. Is chamfered into an inclined part. The ridge line where the bottom surface and the inclined part intersect is formed in a straight line along one side of the base having a polygonal shape when the bottom surface is viewed from the front, and this ridge line approaches to the vicinity of the screw hole. doing. For this reason, in the said blade-tip-exchange-type rotary tool, there was a problem that the area of the bottom surface of the insert mounting portion could not be secured widely, and good seating property of the cutting insert could not be obtained.
In particular, the vicinity of the central part of one side of the base corresponds to the central part of the side of this base, even though it is the part where the load received from the cutting edge is the largest and the most demanding of strength. The bottom surface portion where the bottom surface and the ridge line of the inclined portion are closest to the screw hole has a problem that it is difficult to meet the demand for higher strength because of its narrow structure.

  The present invention is made under such a background, and can ensure a wide area of the bottom surface of the insert mounting portion, in particular, the area of the bottom surface portion corresponding to the central portion of the side of the polygonal base. It is an object of the present invention to provide a blade-tip-replaceable rotary tool that can secure a wide range of cutting force and is excellent in seating stability of a cutting insert.

  In order to solve the above-described problems and achieve such an object, the cutting edge-replaceable rotary tool of the present invention has a cutting edge on the outer periphery of the tip of the disk-shaped tool body and penetrates a mounting hole in the center. Cutting edge replacement in which formed polygonal flat cutting inserts are detachably mounted with mounting screws spaced apart from each other in a plurality of circumferential directions, and the tool body is rotated around its axis to cut the work material A plurality of polygonal bases corresponding to the outer shape of the cutting insert are provided at the front end of the tool main body corresponding to the cutting insert, An insert mounting portion to which the cutting insert is mounted is provided, and the insert mounting portion is disposed on an outer periphery of a screw hole into which the mounting screw is screwed, and a seating surface of the cutting insert is brought into contact therewith. A bottom surface and a wall surface against which an outer peripheral surface of the cutting insert comes into contact; an outer periphery of the bottom surface of the insert mounting portion is chamfered to be an inclined portion; and the bottom surface of the insert mounting portion and the inclined portion are The intersecting ridge lines are formed in a convex shape in which a portion corresponding to one side of the base is projected outward when the bottom surface is viewed from the front.

  In the blade-exchangeable rotary tool having the above configuration, when the ridgeline where the bottom surface of the insert mounting portion intersects the inclined portion is viewed from the front, the portion corresponding to one side of the base is stretched outward. The protrusion is formed in a protruding shape, and thus the area of the bottom surface of the insert mounting portion can be ensured as much as a part of the ridge line protrudes outward.

The ridgeline has a convex curve shape in which portions corresponding to the respective sides of the base stand outwardly when the bottom surface is viewed from the front, and they continuously form an arc shape. that it has been formed in.

  In this case, the bottom surface of the insert mounting portion is formed in a ring shape by being partitioned by a screw hole on the inside and a ridge line having an arc shape on the outside. When being fixed by the mounting screw, the cutting insert strongly contacts the bottom surface. In this case, since the bottom surface is formed in a ring shape, the load from the cutting insert is almost uniformly distributed over the entire bottom surface, and a stable seating property can be obtained for the cutting insert.

  Also, when cutting, the vicinity of the center of one side of the base is the part where the load received from the cutting edge is the largest and the strength is required, but as mentioned above, the bottom is formed in a ring shape Therefore, the bottom surface near the central part of one side of the base can also secure the same area as the other part, and thereby the strength of this part can be increased to the same level as the other part. In this respect, it is possible to ensure excellent seating performance of the cutting insert.

Further, the cutting insert, the cutting edge is formed in pairs with each other in front and back, the cutting edge, it is rather preferable that protrudes in the thickness direction outward than the seating surface, It is preferable that the cutting edge on the side opposite to the cutting edge contributing to cutting is accommodated in the inclined portion .

In this way, when the cutting edge protrudes from the seating surface, a wide breaker portion can be formed on the back side of the cutting edge, which is advantageous when processing a tough work material such as steel. Become. Here, even when the cutting edge protrudes from the seating surface in this way, the outer peripheral portion of the bottom surface of the insert mounting portion is chamfered to be an inclined portion, so that the cutting edge on the side opposite to the cutting edge that contributes to cutting That is, the cutting edge on the back side facing the insert mounting portion is accommodated along the inclined portion, and the cutting edge on the back side does not interfere with the insert mounting portion.
That is, even if it is a cutting insert in which the cutting edge for processing a work material rich in toughness protrudes from the seating surface, it can be suitably attached to the insert mounting portion.
Moreover, it is preferable that the linear notch is formed in the part which adjoins the said bottom face and the said wall surface of the said insert attaching part.
Furthermore, it is preferable that the seating surface of the cutting insert is formed in a ring shape corresponding to the shape of the bottom surface of the insert mounting portion.

  As described above, according to the present invention, when the ridge line where the bottom surface of the insert mounting portion and the inclined portion intersect is seen from the front, the portion corresponding to one side of the base projects outward. Since it is formed in a convex shape, the area of the bottom surface of the insert mounting portion can be ensured as much as the ridge line protrudes outward in this way, so that the seating stability of the cutting insert is excellent.

It is the perspective view which looked at the blade-tip-exchange-type milling cutter which is one Embodiment of the blade-tip-exchange-type rotary tool of this invention from the front-end | tip outer peripheral side. It is a front view of the blade-tip-exchange-type milling machine shown in FIG. It is the perspective view which looked at the tool main body of the blade-tip-exchange-type milling machine shown in FIG. 1 from the tip outer peripheral side. It is an expansion perspective view which shows the state which removed the cutting insert from the blade-tip-exchange-type milling machine shown in FIG. It is a perspective view of the cutting insert attached to the blade-tip-exchange-type milling machine shown in FIG. It is a front view of the cutting insert attached to the blade-tip-exchange-type milling machine shown in FIG. It is a side view of the cutting insert attached to the blade-tip-exchange-type milling machine shown in FIG. It is sectional drawing which follows the VIII-VIII line of FIG. It is the enlarged view seen from a certain direction which shows the state which removed the cutting insert from the blade-tip-exchange-type milling machine shown in FIG. FIG. 10 is a sectional view taken along line XX in FIG. 9. (A)-(c) is an enlarged view of the XI circle | round | yen part of FIG. 10, Comprising: It is a figure which shows various examples.

FIGS. 1 to 3 show a blade-exchangeable milling cutter as an embodiment of the blade-exchangeable rotary tool of the present invention, and FIG. 1 is a perspective view of the blade-exchangeable milling device as viewed from the outer periphery of the tip. Fig. 3 is a front view of the cutting edge exchange milling machine, Fig. 3 is a perspective view of the tool body of the cutting edge exchange milling machine as viewed from the outer periphery of the tip, and Fig. 4 is an enlarged view showing a state where the cutting insert is removed from the cutting edge exchange milling machine shown in Fig. 1. It is a perspective view.
In addition, although the cutting insert 10 is attached to the cutting edge exchange milling cutter 1, the cutting edge exchange milling cutter 1 is mainly used for metal processing.

  As shown in FIG. 1 to FIG. 3, the cutting edge exchange type milling cutter 1 has a tool body 2 having a substantially disk shape with an axis O as the center, and the tool body 2 has a center in the radial direction along the axis O. A mounting portion 3 is provided which extends to the base end side (here, the base end side of the tool body 2 is the upper side in FIG. 2 and the tip end side of the tool body 2 is the lower side in FIG. 2) and has a tool mounting hole 3a. The cutting edge replaceable milling cutter 1 is attached to the spindle of a machine tool (not shown) through the attachment portion 3. At the tip side of the tool body 2, a blade part 4 having a diameter larger than that of the attachment part 3 is provided. When the cutting edge-exchangeable milling cutter 1 is rotated in the tool rotation direction T around the axis O, The blade portion 4 is used for cutting the work material.

  Further, at the end of the tool body 2 on the distal end side along the axis O direction, the outer surface of the tool body 2 is notched and the tip pockets 6 that open toward the distal end side and the radially outer side are spaced apart in the circumferential direction. A plurality is formed by opening. In the chip pocket 6, a base 7 having a shape corresponding to the outer shape of the cutting insert is provided on the rear side in the tool rotation direction T. That is, here, since the cutting insert is a plate-like body having a regular heptagon, the tip portion of the base 7 has a shape that forms a part of a regular heptagonal column.

FIG. 5 is a perspective view of a cutting insert attached to the blade-tip replaceable milling cutter shown in FIG. 1, FIG. 6 is a front view of the cutting insert attached to the blade-tip replaceable milling cutter shown in FIG. 1, and FIG. The side view of the cutting insert attached to a milling cutter and FIG. 8 are sectional drawings which follow the VIII-VIII line of FIG.
As shown in FIG. 5, the cutting insert 10 is made of a hard material such as cemented carbide and is formed in a regular heptagonal flat plate shape, and includes an insert body 11 having a mounting hole 11a at the center thereof. The insert body 11 includes a pair of front and back rake faces 12 having a regular heptagonal shape when viewed from the front, and a plurality of rake faces 12 that are arranged around the rake faces 12 on the front and back sides and that intersect with the rake faces 12. And a plurality of cutting edges 14 which are formed on the ridge line of the rake face 12 and the outer peripheral face 13 and which make a pair on the front and back. The rake face 12 includes a seating surface 15 provided on the outer periphery of the mounting hole 11a, and a breaker portion 16 that is inclined so as to gradually protrude outward in the thickness direction from the seating surface 15 toward the outer periphery.
Here, the cutting edges 14 arranged on each side of the rake face 12 are rotationally symmetric with respect to each other about the central axis of the rake face 12.

  That is, the cutting insert 10 of this embodiment is formed such that the cutting edge 14 formed at the intersecting ridge line of the rake face 12 and the outer peripheral face 13 protrudes outward in the thickness direction from the seating face 15. A breaker portion 16 that is inclined with a predetermined inclination angle is formed between the blade 14 and the seating surface 15 to be relatively wide. For this reason, the chip can be easily cut by the breaker portion 16, and a cutting insert capable of processing even a work material rich in toughness is obtained.

FIG. 9 is an enlarged view seen from a certain direction showing a state in which the cutting insert is removed from the cutting edge replaceable milling cutter shown in FIG. 1, and FIG. 10 is a sectional view taken along line XX of FIG.
As shown in FIGS. 4 and 9, an insert mounting portion 20 for mounting the cutting insert 10 is provided on the front surface of the base 7 in the tool rotation direction T. A screw hole 21 is formed in the insert mounting portion 20 along the tangential direction, and a mounting screw 22 for mounting the cutting insert 10 is screwed into the screw hole 21 (see FIG. 1). Further, the insert mounting portion 20 is provided with a bottom surface 23 with which the seating surface 15 of the cutting insert 10 is brought into contact with the outer periphery of the screw hole 21, and the cutting insert 10 is disposed on the bottom surface 23 on the mounting portion 3 side of the tool body. Wall surfaces 24 </ b> A and 24 </ b> B against which the outer peripheral surface 13 is abutted are provided at a predetermined angle and a predetermined interval.

In the cutting insert 10, the seating surface 15 is brought into contact with the bottom surface 23 and the outer peripheral surface 13 is brought into contact with the wall surfaces 24 </ b> A and 24 </ b> B. In this state, the mounting screw 22 is inserted into the mounting hole 11 a of the cutting insert 10. When the tip is screwed into the screw hole 21, the cutting insert 10 is attached to the insert mounting portion 20. Moreover, the cutting insert 10 is removed from the insert attachment part 20 by removing the attachment screw 22.
As described above, the cutting insert 10 is detachably attached to the insert mounting portion 20 on the outer periphery of the tip end of the tool body 2.

Further, the outer periphery of the bottom surface 23 of the insert mounting portion 20 is chamfered to form an inclined portion 25. Specifically, inclined portions 25 are respectively formed on the outer side and the lower surface side with respect to the tool body 2 from the center of the screw hole 21 on the bottom surface 23 of the insert mounting portion 20. FIGS. 11A to 11C are enlarged views of the XI circle portion of FIG. 10, and are diagrams showing various examples of the inclined portion 25.
As an example of the inclined portion 25, for example, one having a flat cross-sectional shape (25a) as shown in FIG. 11 (a), and having a single radius R as shown in FIG. 11 (b). As shown in FIG. 11 (c), there is a rounded one (25b) and a round one (25c) whose cross-sectional shape is such that an arc having a radius Ra and an arc having a radius Rb are continuously connected. In addition, the inclined portion 25 may be one in which arcs having a cross-sectional shape of 3 or more are continuously connected.
As shown in FIG. 4, the ridge line 26 where the bottom surface 23 and the inclined portion 25 intersect with each other is a convexity that a portion corresponding to one side 7A of the base 7 projects outward when the bottom surface 23 is viewed from the front. The shape is curved, and they are formed so as to form an arc shape continuously. Therefore, the bottom surface 23 of the insert mounting portion 20 is partitioned by the screw hole 21 on the inner side and the ridge line 26 having an arc shape on the outer side, and is formed in a substantially ring shape as a whole.
Further, the seating surface 15 of the cutting insert 10 is formed in a ring shape corresponding to the shape of the bottom surface 23 of the insert mounting portion 20.
As shown in FIGS. 4 and 5, the bottom surface 23 of the insert mounting portion 20 is slightly cut out in a straight line at a portion adjacent to the wall surfaces 24A and 24B. Although it is not formed, it can be said that it is formed in a substantially ring shape. Of course, the bottom surface 23 may be formed in a ring shape as a whole by cutting out portions adjacent to the wall surfaces 24A and 24B in a concave curved shape.

  As described above, according to the cutting insert 10 according to the present embodiment, the seating surface 15 of the cutting insert 10 is brought into contact with the bottom surface 23 and the outer peripheral surface 13 is brought into contact with the wall surfaces 24A and 24B. The mounting screw 22 is inserted into the mounting hole 11 a of the cutting insert 10, and the tip of the mounting screw 22 is screwed into the screw hole 21, so that the cutting insert 10 is mounted on the insert mounting portion 20.

  At this time, the cutting insert 10 is formed by projecting the cutting edge 14 from the seating surface 15 outward in the thickness direction of the cutting insert so that even a work material rich in toughness can be processed. As described above, the cutting insert 10 is formed by protruding the cutting edge 14 outward from the seating surface 15, but when the cutting insert 10 is attached to the insert attachment portion 20, the outer periphery of the bottom surface 23 is chamfered in advance. Since the inclined portion 25 is formed, the cutting edge 14 on the side opposite to the cutting edge 14 contributing to cutting, that is, the cutting edge 14 on the back side facing the insert mounting portion 20 is accommodated in the inclined portion 25, The rear cutting edge 14 is prevented from interfering with the insert mounting portion 20 in advance.

At this time, the ridge line 26 where the bottom surface 23 and the inclined portion 25 of the insert mounting portion 20 intersect is projected outward when the bottom surface 23 is viewed from the front, corresponding to one side 7A of the base 7. Compared with the convex curve shape described in the background art, this portion is formed in a straight line along one side of the base having a polygonal shape (shown by a two-dot chain line L in FIG. 4). As a result, the area of the bottom surface 23 of the insert mounting portion 20 can be widened as much as the ridge line 26 is formed to project outward. As a result, the seating stability of the cutting insert 10 is excellent.

  In addition, in this embodiment, when the ridge line 26 is viewed from the front, the portion corresponding to each side 7A of the base 7 has a convex curve shape protruding outward, and The bottom surface 23 of the insert mounting portion is partitioned by a screw hole 21 on the inside and a ridge line 26 having an arc shape on the outside to form a ring shape. Is formed. Therefore, the cutting insert is strongly brought into contact with the bottom surface 23 formed in the ring shape when the mounting screw 22 is screwed and fixed to the insert mounting portion 20.

  In this case, since the bottom surface 23 with which the seating surface 15 of the cutting insert comes into contact is formed in a ring shape, the load received from the cutting insert 10 when the mounting screw 22 is screwed is distributed almost uniformly over the entire bottom surface 23. Thus, a stable seating property with respect to the cutting insert 10 is obtained.

  Further, when cutting, the vicinity of the central portion of one side 7A of the base 7 is a portion where the load received from the cutting edge 14 is the largest and the strength is required. Since it is formed in a ring shape, the bottom surface 23 in the vicinity of the central portion of one side 7A of the base 7 can also secure the same area as the other portions, and the strength of this portion is comparable to that of the other portions In this respect, the cutting insert 10 can be seated in a more stable state.

In addition, this invention is not limited to the above-mentioned embodiment, A various change can be added in the range which does not deviate from the meaning of this invention.
For example, in the above-described embodiment, a regular heptagonal flat plate is used as the cutting insert 10, but is not limited to this, and a simple heptagonal flat plate cutting insert or other regular polygon or simple polygon is used. The present invention is also applicable to those using a flat cutting insert.

  Moreover, in the said embodiment, when the bottom face 23 is seen from the front, the ridge line 26 part corresponding to each side 7A of the base 7 has a convex curve shape projecting outward, and these ridge line parts are smooth. Although it connects and it forms so that it may form circular arc as a whole, when it sees the bottom face 23 from the front, it is not restricted to this, The ridgeline part corresponding to each edge | side 7A of the base 7 is connected discontinuously. A convex curve shape may be drawn, and further, a straight line combination may be formed so as to project outward without drawing a convex curve shape.

  In the present embodiment, the cutting insert 10 having the paired cutting edges 14 on the front and back sides has been described as an example. However, the present invention is not limited thereto, and the present invention is applicable to a cutting insert having the cutting edges 14 only on the surface. The invention is applicable.

DESCRIPTION OF SYMBOLS 1 Cutting edge replaceable milling machine 2 Tool main body 4 Blade part 6 Tip pocket 7 Base 7A One side of base 10 Cutting insert 11 Insert main body 11a Mounting hole 12 Rake face 13 Outer peripheral face 14 Cutting edge 15 Seating face 16 Breaker part 20 Insert mounting part 21 Screw hole 22 Mounting screw 23 Bottom surface 24A, 24B Wall surface 25 Inclined portion 26 Edge line T Tool rotation direction (rotation direction)

Claims (4)

A polygonal flat plate-shaped cutting insert that has a cutting edge on the outer periphery of the tip of the disk-shaped tool body and that has a through hole formed in the center, can be attached and detached with mounting screws at intervals in the circumferential direction. It is a blade-tip-replaceable rotary tool that is mounted and the tool body is rotated around its axis to cut the work material,
The tip of the tool body is provided with a plurality of polygonal bases corresponding to the outer shape of the cutting insert, corresponding to the cutting insert,
On the front surface in the rotational direction of the base, an insert mounting portion to which the cutting insert is attached is provided,
The insert mounting portion is disposed on the outer periphery of an opening of a screw hole to which the mounting screw is screwed, and a bottom surface on which a seating surface of the cutting insert comes into contact, and a wall surface on which the outer peripheral surface of the cutting insert comes into contact And
The outer periphery of the bottom surface of the insert mounting portion is chamfered to be an inclined portion,
A ridge line where the bottom surface of the insert mounting portion and the inclined portion intersect is formed in a convex shape in which a portion corresponding to one side of the base protrudes outward when the bottom surface is viewed from the front.
The ridge line has a convex curved shape in which portions corresponding to the sides of the base stand outwardly when the bottom surface is viewed from the front, and the ridge lines continuously form an arc shape. A blade-tip-exchange-type rotary tool characterized by being formed so as to form . The cutting insert is formed such that the cutting edges are paired with each other on the front and back sides,
The cutting edge is formed to protrude outward in the thickness direction from the seating surface,
2. The blade- tip-replaceable rotary tool according to claim 1, wherein a cutting blade opposite to a cutting blade that contributes to cutting is housed in the inclined portion . The blade tip replaceable rotary tool according to claim 1 or 2, wherein a portion of the bottom surface of the insert mounting portion adjacent to the wall surface is cut out linearly . The cutting edge-replaceable rotary tool according to any one of claims 1 to 3, wherein the seating surface of the cutting insert is formed in a ring shape corresponding to the shape of the bottom surface of the insert mounting portion. .

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