JPH0560720U - Indexable insert and indexable cutting tool - Google Patents

Abstract

(57) [Summary] [Structure] On the outer periphery of the tool main body 1, a chip row composed of a throw-away chip 7 is formed along the chip discharge groove 5. The throw-away tip 7 is formed on a substantially equilateral triangular upper surface 8 facing the outer peripheral side of the tool, a cutting edge 12 formed on a side edge portion 11 of the upper surface 8, and both end portions of the cutting edge 12, and The cutting blade 12 is provided with a corner blade 14 that intersects at an obtuse angle. Furthermore, the throw-away tips 7 and 7 adjacent to each other in each tip row are such that one of the one corner blades 14 faces the side edge portion 11 of the upper surface 8 of the other substantially in parallel, and these cutting edges. The rotation loci of the tool 12 about the tool axis O are arranged so as to be offset in the circumferential direction and the axial direction of the tool body 1 so as to overlap each other with an overlap amount ε. [Effect] The number of chips forming one chip row can be increased, the cutting load individually acting can be reduced, and the chip life can be extended.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention is a flat throw-away tip (hereinafter referred to as a tip) made of a hard material such as cemented carbide, and such a tip is attached to the outer periphery of a tool body to form an outer peripheral blade. The present invention relates to a throw-away type cutting tool.

[0002]

[Prior Art]

 As such a throw-away type cutting tool, for example, a throw-away type end mill (hereinafter abbreviated as end mill) as described in Japanese Utility Model Laid-Open No. 62-168210 is known. This end mill has a chip discharge groove spirally formed on the outer periphery of the tool body, and a plurality of chip mounting seats are formed along the chip discharge groove on the rear side of the chip discharge groove in the tool rotation direction. A plate-like chip is detachably attached to these chip mounting seats with a clamp screw to form a chip row.

Here, the tip mounted on the end mill of this publication has a substantially square upper and lower surface and four peripheral surfaces continuous with the side ridges of the upper and lower surfaces, and the upper surfaces face each other. Cutting edges are formed on the pair of side ridges. The tip is attached to the tip with the upper surface facing the outer circumference of the tool, one of the cutting edges facing the tool rotation direction, and the positive or negative axial rake angle being applied to these cutting edges. It is seated on a seat. Furthermore, in the end mill of this publication, the pitch of the inserts adjacent to each other in each insert row is narrowed to the minimum, and each insert mounting seat is slightly displaced in the peripheral direction of the insert to rotate the cutting edge around the insert axis. By making the trajectory continuous in the tool axis direction, an outer peripheral blade having a length exceeding the cutting edge length of a single chip is formed in each spiral groove.

By the way, in the end mill having such a rectangular flat plate-like tip, when the tip pitch of each tip row is narrowed as described above, the peripheral surface of the tip and the wall surface of the tip mounting seat are It is not possible to secure a large contact area and it is difficult to increase the wall thickness between the wall surfaces of adjacent chip mounting seats, which makes it difficult to firmly hold the chip mounted on the outer periphery of the tool body. The problem arises that Therefore, in order to solve such a problem, as a tip used for such a throw-away type cutting tool, a tip having an equilateral triangular plate shape and having a cutting edge formed on at least one side ridge of its upper surface is used. Is being considered. When such an equilateral triangular plate-shaped insert is used and the insert row is formed so that the cutting edge is located on the front side in the tool rotation direction, the wall surfaces of the insert mounting seats that are adjacent to each other in each insert row Are formed such that the distance in the tool axis direction increases toward the rear side in the tool rotation direction. For this reason, it becomes possible to secure a sufficient thickness between these wall surfaces and firmly hold the chip.

[0005]

[Problems to be solved by the device]

 However, in a throw-away type cutting tool in which a chip row is formed using such an equilateral triangular plate-shaped insert, the rotation locus around the tool axis line of the cutting edge of each chip row is the tool axis line as in the conventional end mills described above. In the case of continuous chips in the same direction, if the pitch in the tool axis direction between adjacent chips in each chip row is narrowed to the minimum, the misalignment in the tool circumferential direction of each chip must be increased, and as a result, The twist of the chip row becomes large, and it becomes impossible to form a desired number of peripheral blades. On the other hand, in order to avoid such inconvenience, if the tips are arranged so that the deviation in the tool circumferential direction does not become too large, the amount of so-called overlapping of the rotation loci of the cutting edges around the tool axis in the tool axis direction, The amount of overlap cannot be taken too large. Therefore, in this case, the number of chips forming one chip row is reduced, and conversely, the cutting load acting on each chip is increased, resulting in a significant shortening of the chip life.

Further, in such an equilateral triangular plate-shaped tip, since both ends of the cutting edge are formed at an acute angle of 60 °, there is a problem that chipping or the like is likely to occur at both ends of the cutting edge. ..

[0007]

[Means for Solving the Problems]

 The present invention has been made in order to solve such a problem, and the chip of claim 1 has upper and lower surfaces having a substantially equilateral triangle shape and three peripheral surfaces connected to the side ridges of the upper and lower surfaces. In the tip formed by forming a cutting edge on at least one of the three side ridges of the upper surface, in the ridge line portion intersecting with the peripheral surfaces, at least one peripheral surface continuous with the cutting edge is provided. At the ridges intersecting with other peripheral surfaces, notch surfaces intersecting these peripheral surfaces at an obtuse angle are formed, and at the intersecting ridges between this notch surface and the upper surface, corner blades intersecting at obtuse angles are formed. It is characterized by being formed.

Further, in the throw-away type cutting tool according to claim 2, at least one row of insert rows made up of one or more detachable inserts having a cutting edge is provided on the outer periphery of the tool body rotated around the axis. In the throw-away cutting tool formed as described above, the tip has a substantially equilateral triangular upper surface facing the outer peripheral side of the tool, and at least one of the side ridges of the upper side of the upper ridge in the front in the tool rotation direction. And a corner blade formed at both ends of the cutting edge and intersecting the cutting edge at an obtuse angle. The circumference of the tool body should be such that one of the blades faces the other side edge of the top surface of the other chip substantially parallel to each other, and the rotation loci of the cutting edges of these tips overlap each other. Direction and axis direction The feature is that they are arranged in a staggered manner.

[0009]

[Action]

 According to the tip having the above-mentioned configuration, the corner edges that intersect the cutting edge at an obtuse angle are formed at both ends of the cutting edge, and the chip strength is prevented at both ends of the cutting edge to prevent chipping of the tip. be able to. In addition, in the above throw-away cutting tool that uses such inserts to form a row of inserts, it is possible to reduce the pitch between the inserts by the amount of the corner blades formed, thus suppressing misalignment in the tool circumferential direction. At the same time, the overlapping amount of the cutting edges can be increased. As a result, the number of chips forming one chip row can be increased and the cutting load acting on each chip can be reduced.

[0010]

【Example】

 1 to 3 are end mills showing an embodiment of the present invention. In these figures, the tool body 1 is formed of steel or the like into a substantially cylindrical shape, and a notch 2 as shown in FIG. 3 is formed at the base end of the tool, and the spindle end of the machine tool is formed at the center thereof. A mounting hole 3 is formed for mounting on. On the outer peripheral portion of the tool body 1, there is provided a spiral chip discharge groove 5 which is twisted around the tool axis O from the tool tip surface 4 toward the tool base end side at a negative twist angle. A plurality of articles (four articles in this embodiment) are formed at equal intervals.

On the rear side of the chip discharge grooves 5 in the tool rotation direction, there are formed chip mounting seats 6 that open to the outer peripheral surface of the tool body 1 and the chip discharge grooves 5. The tip mounting seat 6 is composed of a bottom surface 6a of a substantially equilateral triangle which is lowered one step from the outer peripheral surface of the tool body 1, and two wall surfaces 6b and 6c standing upright from the bottom surface 6a and connected to the outer peripheral surface. The bottom surface 6a is arranged such that one side of the equilateral triangle faces the front side in the tool rotation direction, and the wall surfaces 6b and 6c are arranged so as to be continuous with the other two sides of the triangle. Therefore, of these wall surfaces 6b and 6c, one wall surface 6b faces the tool tip end side, and the other wall surface 6c faces the tool base end side, and these wall surfaces 6b and 6c are rearward in the tool rotation direction. From the side toward the front side, the narrow angle is set to 60 °. Further, these chip mounting seats 6 ... Are formed in each chip discharge groove 5 in a stepwise manner along the chip discharge grooves 5 toward the front side in the tool rotation direction from the tool tip side toward the base end side. Has been done. Further, in the two chip mounting seats 6 and 6 which are adjacent to each other in the tool axis O direction, the one wall surface 6b of the tip mounting seat 6 on the tool tip side facing the tool tip side and the other on the tool base end side of the other. The tip mounting seat 6 is formed so as to intersect the wall surface 6c facing the tool base end side.

On the other hand, the chips 7 mounted on these chip mounting seats 6 are made of hard material such as cemented carbide, and as shown in FIG. 5 to FIG. , A positive type chip having three peripheral surfaces 10 arranged around the upper and lower surfaces 8 and 9, and three side ridges of the upper surface 8 which are ridges intersecting with these peripheral surfaces 10. A cutting edge 12 is formed on each of 11 ... Further, each of the three corner portions C1 ... Where the two peripheral surfaces 10, 10 of the chip 7 intersect with each other has a notch surface 13 that intersects both of the peripheral surfaces 10, 10 at an equal angle as a positive surface. A corner blade 14 is formed at the ridge line where the cutout surface 13 and the upper surface 8 intersect. Therefore, the corner blades 14 are formed at both ends of the cutting blade 12 in a direction intersecting the cutting blade 12 at 120 °. A through hole 15 is formed in the center of the chip 10 in a plan view and opens on both upper and lower surfaces 8 and 9.

Then, such a tip 7 has its upper surface 8 directed to the outer peripheral side of the tool, and its lower surface 9 is brought into close contact with the bottom surface 6a, and one of the three peripheral surfaces 10 ... The surface 10A is oriented in the tool rotation direction, one of the other two peripheral surfaces 10B is brought into contact with the wall surface 6c toward the tool tip side, and the other peripheral surface 10C is oriented toward the tool base end side. It is seated by abutting against the wall surface 6b and is fixed to the tool body 1 by a clamp screw 16. As a result, one of the three cutting blades 12 ... Is arranged at a position facing the tool rotation direction and facing the chip discharge groove 5. Further, in this state, as shown in FIG. 5, the two tips 7A and 7B adjacent to each other in one tip row have the ends of the cutting blades 12 and 12 facing the tool rotation direction in the tool axis O direction. The tool body 1 is displaced in the circumferential direction so as to be overlapped by a predetermined overlap amount ε, and is arranged as close as possible in the tool axis O direction.

That is, of these tips 7A and 7B, one tip 7A located on the tool tip side (lower side in FIG. 5) is the other tip 7B located on the tool base end side (upper side in FIG. 5). The notch surface 13A located on the tool base end side of the peripheral surface 10A, which is displaced to the rear side in the tool rotation direction (right side in FIG. 5) and faces the tool rotation direction (left side in FIG. 5), is the other tip 7B. Are arranged close to each other in the tool axis O direction so as to face the peripheral surface 10B facing the tool tip side. Therefore, the corner blade 14A connected to the cutout surface 13A of the one tip 7A faces the side edge portion 11B connected to the peripheral surface 10B among the side edge portions 11 of the upper surface 8 of the other tip 7B substantially in parallel. Will be arranged as follows. As a result, a chip row is formed on the outer periphery of the tool body 1 for each chip discharge groove 5, and these chip rows allow the outer peripheral blades continuous in the rotation locus to extend along the chip discharge groove 5. Formed in.

In the end mill having such a configuration, the tip 7 mounted on the outer periphery of the tool body 1 has the corner blades 14 formed at the corners C1 thereof, and as shown in FIG. 5, they are adjacent to each other. The chips 7A and 7B are arranged so that the corner blade 14A of one chip 7A faces substantially parallel to the side edge portion 11B of the other chip 7B. Therefore, in each chip row, it is possible to dispose the chips 7 ... In the tool axis O direction while keeping the displacement of the chips 7 ... in the tool circumferential direction from becoming unnecessarily large. It is possible to set a large overlap amount ε with which the cutting edges 12 of the tips 7 overlap in the tool axis O direction while forming a desired number of outer peripheral blades by reducing the twist of the row. By doing so, the number of chips 7 forming one chip row can be increased, that is, the number of effective blades of the end mill can be increased, and the cutting load acting on each chip 7 can be reduced. Is possible. Therefore, according to the end mill having the above structure, the life of the tip 7 can be extended, and stable and smooth cutting work can be performed over a long period of time.

Further, in the chip 7 having the above-described structure, the notch surface 13 is formed at the intersecting ridge line portion between the peripheral surfaces 10, 10, and the cutting edge 12 is provided with 120 at the intersecting ridge line portion between the notch surface 13 and the chip upper surface 8. Since the corner blades 14 that intersect at ° are formed, the strength of the cutting edges at both ends of the cutting blade 12 can be significantly improved, and chip breakage at this portion can be prevented in advance. Is possible. Therefore, in combination with the effect of reducing the cutting load by increasing the number of effective blades described above, the life of the tip 7 can be further extended.

Although the tip 7 is described as a positive type in this embodiment, it may be a negative type. Further, in the above-mentioned embodiment, the notch surface 13 intersects the peripheral surfaces 10, 10 sandwiching it at the same angle, and the corner blade 14 intersects both the cutting blades 12, 12 sandwiching this by 120 °. However, the present invention is not limited to such a structure. That is, the angle intersecting the one cutting edge 12 and the angle intersecting the other cutting edge 12 may be set to be different. Further, in the end mill of the above-mentioned embodiment, the insert row is formed only by the inserts 7 of the same shape, and the outer peripheral blade is formed by this, but the insert of another shape is provided at the tip of the tool of the insert row, or the bottom blade is formed. May be provided.

[0018]

[Effect of the device]

 As explained above, according to the throw-away type cutting tool of the present invention, in the insert row formed on the outer periphery of the tool body, it is possible to suppress the deviation of each insert in the peripheral direction of the tool from increasing and to provide a desired number of outer peripheral blades. Even with the provision of, it is possible to narrow the pitch between the chips in the tool axis direction and increase the overlap amount of the cutting edges. As a result, the number of chips forming one chip row can be increased, cutting load acting on each chip can be reduced, and the chip life can be extended. In addition, the corner blades formed at both ends of the cutting edge can improve the strength of the cutting edge and prevent chipping of the tip, which, in combination with the above effects, further extends the chip life. be able to.

[Brief description of drawings]

FIG. 1 is a side view of an end mill according to an embodiment of the present invention.

FIG. 2 is a front view from the tool tip side of the end mill shown in FIG.

FIG. 3 is a rear view of the end mill shown in FIG. 1 viewed from the tool base end side.

FIG. 4 is a development view of a chip row of the end mill shown in FIG.

5 is a plan view from the tip upper surface 8 side showing the tips 7, 7 adjacent to each other in the tip row of the end mill shown in FIG. 1. FIG.

6 is a side view of the chip 7 shown in FIG. 5 as viewed in the X direction.

7 is a YY cross-sectional view of the chip shown in FIG.

[Explanation of symbols]

 1 Tool Main Body 5 Chip Discharge Groove 6 Chip Mounting Seat 7 Chip 8 Chip Top Surface 10 Chip Peripheral Surface 11 Edge Top Edge 11 Edge Ridge 12 Cutting Edge 13 Notch Surface 14 Corner Blade C1 Corner of Top Surface 11 ε Cutting Edge 12 Over Lapping amount O Tool axis

Claims (2)

[Scope of utility model registration request] 1. A cutting blade having upper and lower surfaces of a substantially equilateral triangle and three peripheral surfaces continuous with side ridges of the upper and lower surfaces, and at least one of the three side ridges of the upper surface. In the throw-away tip formed by, among the intersecting ridgelines of the peripheral surfaces, at least the intersecting ridgeline of one peripheral surface continuous with the cutting edge and the other peripheral surface have an obtuse angle to these peripheral surfaces. The throw-away tip is characterized in that a notch surface intersecting with each other is formed, and a corner blade that intersects the cutting edge at an obtuse angle is formed at a ridge line intersection of the notch surface and the upper surface. 2. A throw-away cutting tool in which at least one or more insert-row insertable inserts having cutting edges are formed on the outer periphery of a tool body rotated about an axis. The throw-away tip has a substantially equilateral triangular upper surface facing the outer peripheral side of the tool, a cutting edge formed on at least one side ridge in the front of the tool rotation direction among the side ridges of the upper surface, and this cutting edge. With the corner blades formed at both ends and intersecting the cutting edge at an obtuse angle, the throw-away tips adjacent to each other in the tip row, one of the corner blades of the one throw-away tip, the other, Of the throw-away tip so that they face each other substantially parallel to the other edge of the upper surface of the throw-away tip, and the rotation trajectories of the cutting edges of these throw-away tips overlap each other. A throw-away cutting tool, wherein the throw-away cutting tools are arranged so as to be aligned with each other in the circumferential direction and the axial direction of the tool body.