JP2565518Y2 - Indexable cutting tools - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION In the present invention, a flat indexable insert (hereinafter abbreviated as "tip") made of a hard material such as a cemented carbide is mounted on the outer periphery of a tool body to form an outer peripheral edge. The present invention relates to a indexable cutting tool.

[0002]

2. Description of the Related Art As such a throw-away type cutting tool, for example, a throw-away type end mill (hereinafter abbreviated as an end mill) as described in Japanese Utility Model Laid-Open No. Sho 62-168210 is known. In this end mill, a chip discharge groove is formed in a spiral shape on the outer periphery of the tool main body, and a plurality of chip mounting seats are formed along the chip discharge groove on the tool rotation direction rear side of the chip discharge groove, A flat chip is detachably mounted on these chip mounting seats by clamp screws, and a chip row is formed.

The chip mounted on the end mill disclosed in this publication has upper and lower surfaces of a substantially square shape and four peripheral surfaces connected to side edges of the upper and lower surfaces. A cutting edge is formed on the pair of side ridges.
The tip mounting seat is oriented such that the upper surface is oriented toward the outer periphery of the tool, one of the cutting edges is oriented in the direction of tool rotation, and a positive or negative axial rake angle is given to these cutting edges. Is seated. Further, in the end mill disclosed in this publication, the pitch of the adjacent chips in each insert row in the tool axis direction is reduced to a minimum, and each insert mounting seat is slightly displaced in the tool circumferential direction, so that the rotation trajectory of the cutting edge around the tool axis is reduced. Is made continuous in the tool axis direction, so that an outer peripheral blade having a length exceeding the cutting edge length of a single insert is formed for each spiral groove.

By the way, in such an end mill having a rectangular flat chip, when the pitch of the chips in each chip row is narrowed as described above, the contact between the peripheral surface of the chip and the wall surface of the chip mounting seat is required. It is not possible to increase the area or to increase the thickness between the wall surfaces at the chip mounting seats adjacent to each other, which makes it difficult to firmly hold the chip mounted on the outer periphery of the tool body. Problem arises. Therefore, in order to solve such a problem, as a tip used in such a throw-away type cutting tool, a tip having a regular triangular plate shape and having a cutting edge formed on at least one side edge of the upper surface is used. That is being considered. When such an equilateral triangular flat chip is used and the chip row is formed such that the cutting edge is located on the front side in the tool rotation direction, the wall surfaces of the chip mounting seats adjacent to each other in each chip row are 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 to firmly hold the chip.

[0005]

However, in a throw-away type cutting tool in which a chip row is formed by using such an equilateral triangular plate-shaped chip, a cutting tool of each chip row like the above-mentioned conventional end mill is used. When the rotation trajectory around the axis is continuous in the tool axis direction, if the pitch in the tool axis direction between adjacent chips in each chip row is to be reduced to a minimum, the deviation of each chip in the tool circumferential direction is increased. As a result, the twist of the chip row increases, and it becomes impossible to form a desired number of outer peripheral blades. However, to avoid such inconvenience,
When the inserts are arranged so that the deviation of the inserts in the tool circumferential direction does not become too large, the amount of overlap of the rotation trajectory of the cutting edge around the tool axis in the tool axis direction, so-called overlap amount, cannot be made too large. Would. 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 remarkable reduction in the life of the chip.

In addition, in such an equilateral triangular flat chip, both ends of the cutting edge are formed at an acute angle of 60 °.
There is also a problem that chips are likely to be chipped at both ends of the cutting blade.

[0007]

Means for Solving the Problems The present invention has been made to solve such problems, and the present invention has been made to rotate around an axis.
Around the outer circumference of the tool body
Chip rows of chips are formed in at least one row.
Of the indexable cutting tool
The upper surface of a substantially equilateral triangle facing the outer peripheral side of the tool.
At least one side in the tool rotation direction in the side ridge of the surface
The cutting edge formed on the ridge and the cutting edge formed on both ends of this cutting edge
And a corner blade intersecting the cutting edge at an obtuse angle.
Next, chips adjacent to each other in the above chip row are
One of the corner blades of one tip is the top of the other tip
So as to be substantially parallel to the other side edge and
So that the rotation trajectories of the cutting edges of these tips overlap each other
To be displaced in the circumferential direction and axial direction of the tool body.
It is characterized by being placed .

[0008]

[0009]

In the indexable cutting tool having the above structure, the pitch between the chips can be reduced by the amount of the formed corner blade, and the overlapping amount of the cutting edge can be increased while suppressing the displacement in the tool circumferential direction. Can be taken. Thus, it is possible to increase the number of chips forming one chip row and reduce the cutting load acting on each chip. In addition, the cutting edge is provided at both ends of the cutting edge of the chip.
A corner blade that forms an obtuse angle
In order to improve the edge strength at both ends of the blade,
Injury can be prevented.

[0010]

1 to 3 show an end mill according to an embodiment of the present invention. In these figures, the tool main body 1 is formed from a steel material or the like to form a substantially columnar shape.
A notch 2 as shown in FIG. 1 is formed, and a mounting hole 3 is formed in the center of the cutout 2 for mounting on a spindle end of a machine tool. On the outer peripheral portion of the tool body 1, a helical chip discharge groove 5 twisted at a negative twist angle around the tool axis O from the tool tip end surface 4 toward the tool base end side is provided in the circumferential direction of the tool body 1. A plurality of lines (four 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 opening to the outer peripheral surface of the tool body 1 and the chip discharge grooves 5. The tip mounting seat 6 includes a substantially equilateral triangular bottom surface 6a lowered one step from the outer peripheral surface of the tool body 1, and two wall surfaces 6b and 6c rising from the bottom surface 6a and continuing to the outer peripheral surface. The bottom surface 6a is arranged with one side of the equilateral triangle facing forward 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, 6c, one wall surface 6b faces the tool tip side, the other wall surface 6c faces the tool base end side, and these wall surfaces 6b, 6c are from the rear side in the tool rotation direction. They are formed so as to be separated from each other toward the front side, and the narrow angle is set to 60 °. Also,
The chip mounting seats 6 are formed so as to be displaced in a stepwise manner along the chip discharge grooves 5 toward the front side in the tool rotation direction along the chip discharge grooves 5 from the tool tip side to the base end side for each chip discharge groove 5. I have. Further, in two chip mounting seats 6 and 6 adjacent to each other in the direction of the tool axis O, a wall surface 6b of one of the chip mounting seats 6 on the tool tip side facing the tool tip side and the other chip mounting on the tool base end side. The seat 6 is formed so as to intersect with a wall surface 6c facing the tool base end side.

On the other hand, the chips 7 mounted on the chip mounting seats 6 are made of a hard material such as cemented carbide, and as shown in FIGS.
Three peripheral surfaces 10 arranged around the upper and lower surfaces 8, 9 ...
A positive type chip having a peripheral surface 10
A cutting edge 12 is formed at each of three side edges 11... Also, three corners C at which the two peripheral surfaces 10, 10 of the chip 7 intersect each other.
A cutout surface 13 which intersects both of these peripheral surfaces 10 and 10 at an equal angle is formed as a positive surface in each of the peripheral surfaces 10, and a corner edge 14 is formed at the intersection ridge line between the cutout surface 13 and the upper surface 8. Are formed. Therefore, the corner blades 14 are formed at both ends of the cutting blade 12 in a direction crossing the cutting blade 12 at 120 °. In the center of the chip 10 in a plan view, through holes 15 are formed which open on both surfaces of the upper and lower surfaces 8 and 9.

The tip 7 has the upper surface 8 directed to the outer periphery of the tool, the lower surface 9 adhered to the bottom surface 6a, and one of the three peripheral surfaces 10. While the surface 10A is oriented in the tool rotation direction, one of the other two peripheral surfaces 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. And is fixed to the tool body 1 by a clamp screw 16. Thereby, one of the three cutting blades 12 is arranged at a position facing the chip discharge groove 5 in the tool rotation direction. Further, in this state, two chips 7A and 7B adjacent to each other in one chip row as shown in FIG.
Are displaced in the circumferential direction of the tool main body 1 such that the ends of the cutting blades 12 and 12 facing the respective tool rotation directions overlap with each other in the tool axis O direction by a predetermined overlap amount ε. They are located as close as possible.

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). Rearward in the tool rotation direction (Fig. 5
The notch surface 13A located on the tool base end side of the peripheral surface 10A facing the tool rotation direction (left side in FIG. 5) is shifted to the peripheral surface 10B facing the tool tip side of the other chip 7B. They are arranged close to each other in the tool axis O direction so as to face each other. For this reason, the corner blade 14A connected to the notch surface 13A of the one tip 7A is
Of the side ridges 11 on the upper surface 8 of the other chip 7B, they are arranged so as to be substantially parallel to the side ridges 11B connected to the peripheral surface 10B. As a result, a chip row is formed on the outer periphery of the tool body 1 for each chip discharge groove 5, and the chip row is formed so that a continuous outer peripheral blade extends along the chip discharge groove 5 on the rotation trajectory. Is done.

In the end mill having such a configuration, the chip 7 mounted on the outer periphery of the tool body 1 has a corner blade 14 formed at a corner C1 thereof, and as shown in FIG. 7A and 7B are one chip 7A
Of the other edge 7B of the other chip 7B
Are arranged so as to be substantially parallel to and opposed to each other. For this reason, it is possible to arrange the chips 7 closer to the tool axis O direction while suppressing the deviation of the chips 7... The amount of overlap ε at which the cutting edges 12 of these tips 7 overlap in the direction of the tool axis O can be set large while the desired number of outer peripheral edges are formed by reducing the torsion. Thus, the number of inserts 7 forming one insert 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 insert 7 can be reduced. Becomes Therefore, according to the end mill having the above configuration, the chip 7
Can be extended, and a stable and smooth cutting operation can be performed for a long period of time.

In the chip 7 having the above structure, the peripheral surfaces 10,
A notch surface 13 is formed at the intersection ridge line portion between the 10, and a corner blade 14 intersecting the cutting blade 12 at 120 ° is formed at the intersection ridge line portion between the notch surface 13 and the chip upper surface 8. The strength of the cutting edge at both end portions of the blade 12 can be greatly improved, thereby making it possible to prevent chipping or the like at this portion. Therefore,
Combined with the above-described effect of reducing the cutting load due to the increase in the number of effective blades, it is possible to further extend the life of the tip 7.

In this embodiment, the chip 7 is described as a positive type, but it may be a negative type. Further, in the above embodiment, the notch 13 intersects the peripheral surfaces 10 and 10 at an equal angle, and
Although the corner blade 14 is formed so as to intersect both the cutting blades 12 sandwiching the corner blade at 120 °, the present invention is not limited to only such a blade. That is, the angle at which one of the cutting edges 12 intersects may be set to be different from the angle at which the other cutting edge 12 intersects. Furthermore, in the end mill of the above-described embodiment, the chip row is constituted only by the same shape of the chip 7 and the outer peripheral edge is formed by this. However, a chip of another shape is provided at the tip of the tool of the chip row, or A configuration such as provided may be employed.

[0018]

As described above, according to the indexable cutting tool of the present invention, in a row of chips formed on the outer periphery of the tool body, it is possible to suppress the deviation of each chip in the circumferential direction of the tool from becoming large. Although the number of outer peripheral blades is provided, the pitch between the chips in the tool axis direction can be narrowed to increase the amount of overlap of the cutting blades. As a result, the number of chips forming one chip row can be increased, the cutting load acting on each chip can be reduced, and the life of the chip can be extended. In addition, since the corner blades formed at both ends of the cutting blade can improve chip strength and prevent chipping, the chip life can be further extended in combination with the above effects. Can be.

[Brief description of the drawings]

FIG. 1 is a side view of an end mill showing one embodiment of the present invention.

FIG. 2 is a front view of the end mill shown in FIG. 1 as viewed from a tool tip side.

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

FIG. 4 is a development view of a tip row of the end mill shown in FIG. 1;

FIG. 5 is a plan view of the chips 7, 7 adjacent to each other in the chip row of the end mill shown in FIG.

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

FIG. 7 is a YY sectional view of the chip shown in FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tool main body 5 Chip discharge groove 6 Chip mounting seat 7 Chip 8 Chip upper surface 10 Chip peripheral surface 11 Edge ridge of chip upper surface 11 Cutting edge 13 Notch surface 14 Corner blade C1 Corner of chip upper surface 11 ε Overcut of cutting edge 12 Lapping amount O Tool axis

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-172723 (JP, U) JP-B-57-55528 (JP, B2) JP-B 3-43010 (JP, B2) JP-B-63 38962 (JP, Y2) Jiko 3 18095 (JP, Y2)

Claims (1)

(57) [Scope of request for utility model registration] 1. An outer periphery of a tool body rotated about an axis.
In addition, a plurality of detachable indexable chips with
At least one or more rows of chips
In the throw-away type cutting tool comprising :
At least one of the square upper surface and the
Cutting edge formed on one side ridge in front of
A cord formed at both ends of the cutting edge and intersecting the cutting edge at an obtuse angle
With a knives blade and adjacent to each other in the tip row.
The throw-away tip that touches the other throw
One of the above-mentioned corner blades of the away tip is
-Substantially parallel to the other edge of the top surface of the away chip
Facing, and these indexable tips
So that the rotation trajectories of the cutting blades overlap each other.
Are displaced in the circumferential direction and axial direction of the tool body.
A throw-away type cutting tool characterized in that: