JP2003025135A - Throw-away end mill and cutting edge tip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting edge tip having a nick with low cutting resistance, superior cutting quality, and high-strength cutting edge and to provide a throw-away end mill using the same. SOLUTION: This cutting edge tip 1 is provided with a slope surface 8 to be a breaker formed along the cutting edge 6 in its upper surface 3, a clearance angle added to the whole circumference of a flank 2, and the nick 11 formed in the cutting edge. The cutting edge 6 and the outer edge 12 of the nick 11 are formed into equal height and a land 13 is formed in the cutting edge 6 and between the outer edge 12 and the slope surface 8. This throw-away end mill 14 with large cutting limit can be provided by forming the nick 11 in a longer side of the cutting edge tip 1 formed into a parallelogrammic flat plate, installing it in one tip of the end mill as an outer circumferential cutting edge, and combining it with a diamond-shape cutting edge tip 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting edge tip with a nick and a throw-away type end mill using this tip.

[0002]

2. Description of the Related Art Nick is effective for rotary cutting tools, especially tools with long blade lengths such as end mills, and by subdividing chips, chip processing is improved, cutting resistance is reduced, and vibration such as chattering occurs. Has the effect of suppressing.
For example, FIG. 6 shows an example of a conventional cutting edge tip 1 mounted on a throw-away type end mill, which is a so-called positive type cutting edge tip constituted by a flank 2 having a clearance angle on the entire side surface. is there. The upper surface 3 is composed of an inclined surface 8 which inclines to a lower part from the pair of cutting edges 6 and a flat surface 9 in the central part. Then, a nick 11 is attached to the cutting blade 6 having the inclined surface 8 to serve as an outer peripheral blade when the end mill is mounted. Outer edge 12 of Nick 11
Has a shape with rounded corners.

FIG. 7 is an enlarged view of portion A in FIG. Due to the combined shape of the clearance angle of the flank surface 2 and the inclined surface 8 with a rake angle, the corner cutting edge 7 has a shape that expands outward as the cutting edge changes in position. And
When the corner cutting edge 7 is viewed from the side, as shown in FIG. 6B, the tip side appears as a lower curve. This also appears at the corner of Nick 11.

[0004]

FIG. 8 shows a state in which the above-mentioned conventional cutting edge tip 1 is mounted on the end mill, and the axial rake angle (twist angle) α is a positive angle. Is set. FIG. 9 is an enlarged view of the tip portion of the cutting blade tip 1 in FIG. Since the cutting edge tip 1 is not twisted, the axial rake angles θ2 and θ4 are positive rake angles in any case, although there are some differences depending on the cutting edge position. However, due to the shape effect as described above, the axial rake angles θ1 and θ3 at the upper corners of the corner cutting edge 7 and the nick 11 appear as negative rake angles. This causes the corner cutting edge 7 and the nick 11 that are most susceptible to damage during cutting to exert the greatest cutting resistance, which is likely to cause cutting edge failure and is a factor that increases the cutting resistance of the entire tool. . Further, the corner cutting edge 7 that has expanded to the outside has a rapid wear and a decrease in fracture resistance.

[0005]

The present invention has been made to solve the above problems. Claim 1
A positive rake angle is formed in the cutting edge part by the inclined surface, and in this cutting edge tip for rolling tools with a nick, the outer edge of the nick is formed at the same height as the cutting edge It is characterized by being. Further, claim 2 is characterized in that the inclined surface is formed around the entire circumference along the cutting edge and the nick outer edge, and a land is provided between the cutting edge and the nick outer edge and the inclined surface. Claim 3
Is a positive-type cutting blade tip in the shape of a parallelogram plate, characterized in that the nick is attached to the long side portion of the parallelogram.

According to a fourth aspect of the present invention, at the tip of the tip mounting groove of the tool body, the cutting edge tip is mounted with its long side as an outer peripheral blade, and at the same time, a diamond shape is formed on the rear end side of the tip mounting groove. The cutting edge chips forming the above are attached at intervals, and the diamond-shaped cutting edge tips are attached at intervals at the tip end portion and the rear end side thereof in the tip attachment groove adjacent to this tip attachment groove. These cutting edge chips are arranged so as to form a continuous cutting edge in a rotation locus.

That is, according to the present invention, the nick is formed at the place where the rake face is an inclined surface so that the outer edge of the nick does not become low, and the knives are formed on the cutting edge as described later. This is to prevent the negative rake angle from appearing. Further, by forming the inclined surface on the entire circumference to make the height of the cutting edge uniform, the chipping resistance of the corner portion is improved and the cutting resistance of the entire cutting edge tip is reduced. Lands are provided along the entire circumference of the cutting edge and the outer edge of the nick to improve the cutting edge strength.

By providing such a nick on the long side of the parallelogrammatic plate-shaped cutting blade tip and constructing an end mill in combination with the diamond-shaped cutting blade tip, the cutting blades are provided at the tips of all the chip mounting grooves. It is possible to put into practical use a throw-away type end mill that has a tip and can make full use of the features of the cutting edge tip with a nick as described above, and it is possible to provide an end mill with a large cutting limit.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described with reference to the drawings. The cutting edge tip 1 shown in FIG. 1 and FIG. 2 is a so-called positive throw-away tip which has a parallelogrammatic plate shape in appearance and whose side surface is formed by a flank 2 having a two-step clearance angle on the entire circumference. . A countersunk hole extending from the upper surface 3 to the lower surface 4 penetrates through the central portion of the chip, and serves as a mounting hole 5 for fastening and fixing the rotary tool body with a screw. The ridgeline intersecting the upper surface 3 and the flank 2 is a cutting edge 6, and the four corners are arc-shaped corner cutting edges 7.

The upper surface 3 of the cutting blade tip 1 is composed of an inclined surface 8 which gradually lowers from the cutting blade 6 toward the central portion, and a flat surface 9 in the central portion. The flat surface 9 is provided with a protrusion 10 extending from the central portion toward the corner cutting edge 7 to form an all-round breaker for improving the processability of the chips discharged by the cutting edge 6 and the corner cutting edge 7. There is.
A nick 11 is attached to the long side of the parallelogram. The outer edge 12 of the nick 11 has an arc shape, a corner is rounded, and is formed by press molding so as to have the same height as the cutting edge 6. Also in the nick 11, the inclined surface 8 is formed on the upper surface 3 along the outer edge 12 thereof. Further, the outer edge 1 of the cutting edge 6 and the nick 11
A narrow land 13 is formed between 2 and the inclined surface 8 to strengthen the cutting edge.

Since the cutting edge 6 is at the same height over the entire circumference, a negative rake angle may appear at any cutting edge position when mounted so that the rake angle in the axial direction is positive. In addition, the reduction in cutting edge strength, which is seen in conventional nicks, does not occur. The same applies to the corner cutting edge 7, and the front cutting edge of the end mill also has improved sharpness due to the rake angle effect of the inclined surface 8. The inclined surface 8 is not limited to a simple inclined surface, and may be, for example, a breaker groove having an arc cross section. Further, the position, the outer edge shape, and the number of the nicks 11 are not limited to those in this embodiment.

FIG. 3 shows a throw-away type end mill 1 which makes full use of the features of the cutting edge tip 1 as described above.
4 is shown. Tip mounting groove 15 on the tool body
Are provided at two locations, and the cutting edge tip 1 having the parallelogram shape is fixed to the tool body at one end thereof by a fastening screw 16. Further, on the rear end side of the tip mounting groove 15, diamond-shaped cutting blade tips 17 are fixed by screws at regular intervals. Further, the diamond-shaped cutting blade tip 17 is attached to the tip portion of the other tip attachment groove 15 and is also attached to the rear end side thereof at a constant interval.

The positional relationship of the cutting blade tips 1 and 17 in the direction of the rotation axis O is shown in FIG. FIGS. 9B and 9C show states in the respective chip mounting grooves 15, and FIG. 9A is a state diagram of a rotation locus which is a combination thereof. Cutting edge tip 1,
Numeral 17 is arranged so as to complement the gap and nick 11, and forms a continuous cutting edge in the rotation locus.
With such a configuration, only one type of cutting blade tip 1 with a nick is required. There is no hassle of preparing multiple types of cutting blade tips with different nicks and using them in combination. Further, since the two cutting edge tips 1 and 17 are arranged at the tip corner portion, which is the most burdened by the impact at the time of biting and the biting of chips, the cutting edge with high strength is formed. In addition, as described above, since the cutting edge shape is such that an increase in cutting resistance is suppressed, it is possible to perform cutting processing with excellent sharpness. In the present invention, the number of chip mounting grooves 15 is not limited to two.

FIG. 5 is a diagram comparing this invention product with a conventional throw-away type end mill in terms of the width of the cutting area. Carbon steel S55C (Brinell hardness 210) diameter 32
Grooved with an mm end mill, cutting speed is 10
It is 0 m / min. The tip mounting groove is 2 grooves, but the conventional product A has one tip blade, nickless cutting blade chip, conventional product B
Is a tip blade with two tip blades and no nick, and conventional product C is a tip blade with two tip blades and a nick with a conventional shape. The invention product is the end mill illustrated in FIG. The maximum cutting depth of the product of the present invention is 32 mm, and the cutting limit is significantly increased as compared with the conventional products A, B and C.

[0015]

EFFECTS OF THE INVENTION In a cutting edge chip having a sloping rake face in the vicinity of the cutting edge, when the cutting edge with a nick is used as the outer peripheral edge of the rotary tool, the nick of the chip and the corner cutting edge portion are axially oriented. Since the appearance of a cutting edge portion having a negative rake angle is prevented, the cutting load does not increase at that portion, and the cutting edge becomes uniform with other cutting edges. Cutting resistance is reduced even when viewed as a whole rotary tool, vibrations such as chatter are suppressed, and a rotary tool with excellent sharpness can be provided. Moreover, the cutting edge is reinforced because the land is provided all around.

The throw-away type end mill of the present invention maximizes the features of the cutting edge tip of the present invention, and is an end mill having a large cutting limit.

[Brief description of drawings]

FIG. 1 is a perspective view of a cutting blade tip according to an embodiment of the present invention.

FIG. 2A is a front view of the cutting edge tip shown in FIG.
(B) is a side view and (c) is a bottom view.

FIG. 3 is a perspective view of a throw-away type end mill according to an embodiment of the present invention, and FIG. 3B is a view of FIG. 3A viewed from the opposite side.

FIG. 4 shows the arrangement of cutting edge tips in the end mill of FIG. 3, (b) and (c) showing individual tip mounting grooves,
(A) shows the arrangement state in the combined chip mounting groove.

FIG. 5 is a cutting limit diagram of a throw-away type end mill.

FIG. 6 is an example of a conventional cutting blade tip, in which (a) is a front view, (b) is a side view, and (c) is a bottom view.

7 is an enlarged view of part A in FIG.

FIG. 8 is a view for explaining a state in which the cutting edge tip of FIG. 6 is attached to an end mill.

9 is an enlarged view of a tip portion of a cutting blade tip in FIG.

[Explanation of symbols]

1 cutting edge tip 6 cutting edges 7 corner cutting edge 8 inclined surface 11 Nick 12 outer edge 13 lands 14 End mill 17 Cutting Edge Chip O rotation axis

Claims (4)

[Claims] 1. A positive rake angle is formed on the cutting edge portion by the inclined surface, and in the cutting edge for a rolling tool provided with a nick on the inclined surface, the outer edge of the nick is aligned with the cutting edge. Cutting edge tip that is formed at the height of. 2. The inclined surface is formed along the entire circumference along the cutting edge and the nick outer edge, and a land is provided between the cutting edge and the nick outer edge and the inclined surface. The cutting edge tip according to Item 1. 3. A positive-shaped cutting blade tip in the shape of a parallelogram plate, wherein the nick is attached to the long side portion of the parallelogram. Cutting edge tip as described. 4. The tip of the tip mounting groove of the tool body,
The cutting edge chip according to claim 3 is mounted with its long side as an outer peripheral blade, and at the same time, diamond-shaped cutting edge chips are mounted at intervals on the rear end side of the chip mounting groove.
In the tip mounting groove adjacent to this tip mounting groove, the cutting blade tips having the above-mentioned rhombus shape are mounted at intervals on the front end portion and the rear end side thereof, and by these cutting blade tips, continuous cutting blades in the rotation locus are provided. A throw-away type end mill, which is arranged so as to form a.