JP2021030328A - Roughing end mill - Google Patents

Abstract

To prevent increase in stock allowance of a specific outer peripheral cutting edge and to obtain excellent vibration-control effect.SOLUTION: Wave-shaped outer peripheral cutting edges 7, which are concave and convex on inner and outer circumference from a tip toward a rear end side of an end mill body, are formed on an outer periphery of the end mill body tip rotated around an axis while phases thereof being shifted. In individual wave-shaped outer peripheral cutting edge 7, pitches P1 to P4 between valley bottoms A on an inner peripheral side of the wavy-shaped end mill body, which are adjacent for a plurality of waveforms C1 to C4 from the tip toward the rear end side of the end mill body, are so made as to be different sizes, and at least a part of waveforms comprises interval adjustment blades 7tB to 7tE which adjust an interval from a valley bottom A on the tip side and to a valley bottom A on the rear end side in the end mill body. In the wave-shaped outer peripheral cutting edges 7 whose phases are shifted, the phases of the valley bottoms A on the tip side of the end mill body, of the plurality of waveforms with equal pitches P1 to P4, are shifted at regular intervals in the axial direction by the interval adjustment blade.SELECTED DRAWING: Figure 4

Description

In the present invention, a plurality of chip discharge grooves extending toward the rear end side are formed on the outer periphery of the tip of the end mill body rotated around the axis at intervals in the circumferential direction, and the end mill rotation directions of these chip discharge grooves are formed. On the outer peripheral side ridge of the wall surface facing, the corrugated outer peripheral blade that is uneven from the tip of the end mill body to the rear end side is uneven on the inner peripheral side and the outer peripheral side, and the phase of the corrugated outer peripheral blade for each of the multiple chip discharge grooves. It relates to a roughing end mill formed by shifting.

As such a roughing end mill, for example, in Patent Document 1, in an end mill having a plurality of wavy outer peripheral blades that repeat peaks and valleys in the radial direction of the outer peripheral blade of a tool, a certain wavy outer peripheral blade is used as a reference shape outer peripheral blade. When, the amount of deviation of the phase of the other at least one wavy outer edge blade in the tool axis direction is the phase of each of the reference shape outer peripheral blades arranged at equal intervals by the value obtained by dividing the wave pitch by the number of blades. The width of 5% or less, which does not include 0% of the wave pitch, is described as being deviated in the tool axis direction.

Further, in Patent Document 1, in an end mill having a plurality of nicks for dividing chips in the radial direction of the outer peripheral blade of a tool, when a certain outer peripheral blade is used as a reference shape outer peripheral blade, at least one other nick is provided. The amount of deviation of the phase in the tool axis direction is 5% or less, not including 0% of the nick pitch, from each phase of the reference shape outer peripheral blades arranged at equal intervals by the value obtained by dividing the nick pitch by the number of blades. The width is also described as being deviated in the tool axis direction.

In the roughing end mill described in Patent Document 1 including such an end mill with a nick, the cutting amount per blade of each outer peripheral blade is slightly different, so that the cutting resistance is dispersed and chatter vibration can be suppressed. , The amount of deviation is 5% or less of the wave pitch and nick pitch from each phase of the standard shape outer peripheral blades arranged at equal intervals by the value obtained by dividing the wave pitch and nick pitch by the number of blades. It is described in Patent Document 1 that it can be prevented.

Japanese Unexamined Patent Publication No. 2010-269437

However, in the roughing end mill described in Patent Document 1, even if the deviation amount is 5% or less of the wave pitch or the nick pitch from each phase of the reference shape outer peripheral blade, the removal allowance of the specific outer peripheral blade is large. It is inevitable that it will become. Since this specific outer peripheral blade will continue to be cut with a large allowance during cutting, the entire end mill will suffer from wear, chipping, chipping, etc. of only the specific outer peripheral blade during long-term cutting. It will reach the end of its life.

Further, in the roughing end mill described in Patent Document 1, the variation in which the wave pitch and the nick pitch can be shifted is limited depending on the number of blades of the outer peripheral blade, and the deviation amount is limited to one pitch of the standard shape outer peripheral blade. Cannot be set. Therefore, the effect of suppressing chatter vibration due to the dispersion of cutting resistance must be limited.

The present invention has been made under such a background, and prevents the replacement allowance of a specific outer peripheral blade from becoming large, and the entire end mill has a life due to wear, chipping, chipping, etc. of only the specific outer peripheral blade. It is an object of the present invention to provide a roughing end mill capable of obtaining an excellent vibration damping effect by widening the variation of the phase shift while being able to avoid becoming.

In order to solve the above problems and achieve such an object, in the present invention, chip discharge grooves extending toward the rear end side are spaced in the circumferential direction on the outer periphery of the tip portion of the end mill body rotated around the axis. Multiple strips are formed with a gap, and the outer peripheral side ridge of the wall surface facing the end mill rotation direction of these chip discharge grooves is uneven on the inner peripheral side and the outer peripheral side from the tip end side of the end mill body toward the rear end side. The corrugated outer peripheral blade is a roughing end mill formed by shifting the phase of the corrugated outer peripheral blade for each of a plurality of chip discharge grooves, and in each of the corrugated outer peripheral blades, from the tip end side to the rear end side of the end mill body. The pitch between the valley bottoms on the inner peripheral side of the end mill body of the waveforms adjacent to the axial direction is set to be different for each of the plurality of waveforms, and at least some of the waveform outer peripheral blades have at least one of them. Waveform of the part Adjusting the distance in the axial direction from the valley bottom on the front end side to the valley bottom on the rear end side in the end mill main body of the plurality of waveforms of the outer peripheral blade. In the waveform outer peripheral blades whose phases are shifted, the phase of the valley bottom on the tip side of the end mill body among the plurality of waveforms having the same pitch is shifted at equal intervals in the axial direction by the spacing adjusting blade. It is characterized by being done.

In the roughing end mill configured in this way, the phase of the valley bottom on the tip side of the end mill body is in the axial direction among the plurality of waveforms having the same pitch due to the spacing adjusting blades between the waveform outer peripheral blades whose phases are shifted. Since they are staggered at equal intervals, the allowance for the outer peripheral blade of a specific waveform does not increase in the waveform connected to the rear end side of the valley bottom on the tip side of the end mill body, and the allowance for the outer peripheral blade of each waveform. Becomes uniform. Therefore, the life of the end mill can be extended without significant wear progressing, chipping or chipping easily occurring on the specific corrugated outer peripheral blade.

Further, in the roughing end mill having the above configuration, in each corrugated outer peripheral blade, between the valley bottoms on the inner peripheral side of the end mill body having a waveform adjacent in the axial direction for each of a plurality of waveforms from the tip end side to the rear end side of the end mill body. The pitches are different in size, and the cutting load acting on each of the plurality of waveforms having different pitches between the valley bottoms is also different. As a result, the vibrations caused by the cutting load cancel each other out, so that chattering vibrations can be suppressed. Moreover, the size of the different pitch is not limited by the number of corrugated outer peripheral blades, and the pitch can be made different in a wide range of variations according to the generated vibration, so that an excellent vibration damping effect can be obtained. It becomes possible to obtain.

Here, the pitch between the valley bottoms on the inner peripheral side of the end mill main body of the corrugated outer peripheral blade gradually increases for each of a plurality of waveforms from the front end to the rear end side of the end mill main body, except for the interval adjusting blade. Is desirable. As a result, at the tip of the end mill body, where it is difficult to secure rigidity because it is separated from the shank at the rear end of the end mill body, the allowance for each corrugation of the corrugated outer peripheral blade is reduced to reduce the cutting load. Therefore, the occurrence of chattering vibration can be suppressed more reliably.

In this case, the pitch between the valley bottoms on the inner peripheral side of the end mill main body of the corrugated outer peripheral blade is set for each of a plurality of waveforms from the front end to the rear end side of the end mill main body, except for the interval adjusting blade. It is desirable that the size gradually increases with a size equal to, and it is desirable that the size gradually increases within the range of less than 0.2 mm. As a result, it is possible to prevent the allowance for each waveform of the corrugated outer peripheral blade from becoming extremely large while moving toward the rear end side of the end mill main body, and the occurrence of defects and chipping is likely to occur.

Further, the pitch between the valley bottoms on the inner peripheral side of the end mill body of the corrugated outer peripheral blade is the axis line from the tip end side to the rear end side of the end mill body, except for a plurality of waveforms on the most tip side of the end mill body. It is desirable that the size is different for each interval equal to the direction. This also prevents the replacement of individual waveforms of the corrugated outer peripheral blade at the tip of the end mill body, for which it is difficult to secure rigidity, from becoming large, and reduces the cutting load at the tip. , The occurrence of chattering vibration can be reliably suppressed.

It should be noted that, in the plurality of waveforms of at least one group of the corrugated outer peripheral blades, the cross section of the rotation locus around the axis along the axis extends in a straight line parallel to the axis at the mountaintop on the outer circumference side of the end mill body. It may have a straight portion and have a cutting edge shape such as a roughing end mill with a nick.

Further, the plurality of waveforms of at least a group of the corrugated outer peripheral blades are moved toward the outer peripheral side in a cross section of the rotation locus around the axis along the axis from the valley bottom of the inner circumference of the end mill body toward the rear end side. After gradually protruding, it may be gradually recessed to the inner peripheral side of the end mill main body through the mountaintop portion on the outer peripheral side of the end mill main body.

As described above, according to the present invention, it is possible to prevent the entire end mill from reaching the end of its life in a short period of time due to wear, chipping, chipping, etc. only on a specific outer peripheral blade, and to provide variations in phase shift. It can be widened, and it is possible to obtain an excellent damping effect against chattering vibration.

It is a perspective view which shows one Embodiment of this invention. It is a front view of the embodiment shown in FIG. It is a side view of the embodiment shown in FIG. It is sectional drawing along the axis of the rotation locus around the axis of the corrugated outer peripheral blade of the plurality of articles of the embodiment shown in FIG. It is sectional drawing along the axis of the rotation locus around the axis of one corrugated outer peripheral blade of the modification of the embodiment shown in FIG.

1 to 4 show an embodiment of the roughing end mill of the present invention. In the roughing end mill of the present embodiment, the end mill body 1 is formed of a hard material such as cemented carbide in a substantially columnar shape centered on the axis O, and the rear end side (right side in FIG. 3) remains columnar. The shank portion 2 of the above, and the portion on the tip side (left side in FIGS. 3 to 5) is the cutting edge portion 3. In such a roughing end mill, the shank portion 2 is gripped by the spindle of the machine tool, is rotated around the axis O in the end mill rotation direction T, and is normally sent out in the direction perpendicular to the axis O, so that the cutting edge portion 3 is used. Roughing is applied to the work material.

The cutting edge portion 3 has a plurality of chip discharge grooves 4 (5 in the present embodiment) that are twisted in the direction opposite to the end mill rotation direction T from the tip end side of the end mill body 1 toward the rear end side, and are spaced in the circumferential direction. It is formed by opening. At the tip of these chip discharge grooves 4, a concave groove-shaped gash 5 is formed along the wall surface of the chip discharge groove 4 facing the end mill rotation direction T, and the wall surface of the gash 5 facing the end mill rotation direction T. A bottom blade 6 extending in the radial direction with respect to the axis O is formed at the intersecting ridge line portion between the end mill body 1 and the tip end surface (tip flank surface).

Further, on the outer peripheral side ridge of the wall surface of the chip discharge groove 4 facing the end mill rotation direction T, the inner peripheral side and the outer peripheral side of the tip of the end mill main body 1 are formed from the outer peripheral end to the rear end side of the bottom blade 6. The corrugated outer peripheral blade 7 having an uneven shape is formed by shifting the phase of the waveform of the corrugated outer peripheral blade 7 for each of the plurality of chip discharge grooves 4. These corrugated outer peripheral blades 7 have a shape in which the cross sections of these corrugated outer peripheral blades 7 that are out of phase with each other along the axis O of the rotation locus around the axis O are equal to each other, except for the interval adjusting blade 7t described later. The corrugated outer peripheral blade 7 is formed by, for example, grinding the outer peripheral relief surface 8 of the corrugated outer peripheral blade 7 on the side opposite to the end mill rotation direction T with a grinding wheel.

Then, in each of the corrugated outer peripheral blades 7, these corrugated outer peripheral blades 7 have a cross section along the axis O of the rotation locus around the axis O for each of a plurality of waveforms from the tip end side to the rear end side of the end mill main body 1. As shown in FIG. 4, the pitches between the valley bottoms A on the inner peripheral side of the end mill main body 1 having a waveform adjacent to the axis O direction are different in magnitude. Here, the phases of the valley bottoms A of the plurality of waveforms of these corrugated outer peripheral blades 7 are such that the phase of the valley bottom A on the tip side of the end mill body 1 has the pitch of two valley bottoms A adjacent to each other in the axis O direction. The intervals are divided by the number of blades (5 blades) and are evenly spaced in the axis O direction. In the present embodiment, the phase of the valley bottom A on the tip end side of the end mill main body 1 having the plurality of waveforms is shifted at equal intervals toward the tip end side of the end mill main body 1 toward the side opposite to the end mill rotation direction T. ing.

Further, in the present embodiment, except for the interval adjusting blade 7t described later, the pitch between the valley bottoms A on the inner peripheral side of the end mill main body 1 of the corrugated outer peripheral blade 7 is from the tip of the end mill main body 1 as shown in FIG. It is formed so as to gradually increase for each of the plurality of waveforms toward the rear end side, and gradually increase for each of the plurality of waveforms from the tip of the end mill body 1 toward the rear end side. Further, each of the plurality of waveforms is formed so as to gradually increase with the same size within a range of less than 0.2 mm.

For example, in the present embodiment, the pitch P1 between the valley bottoms A in the first plurality of waveforms C1 on the most advanced side of the end mill main body 1 is 1.5 mm, and the pitch P1 between the valley bottoms A in the next second plurality of waveforms C2 is set to 1.5 mm. The pitch P2 is 1.6 mm, the pitch P3 between the valley bottoms A in the next third plurality of waveforms C3 is 1.7 mm, and the fourth plurality of waveforms C4 on the rearmost rear end side are further set. The pitch P4 between the valley bottoms A in the above is 1.8 mm, and each pitch P1 to P4 is increased by 0.1 mm with an equal size.

Furthermore, the pitch between the valley bottoms A on the inner peripheral side of the end mill main body 1 of the corrugated outer peripheral blade 7 is from the front end side to the rear end side of the end mill main body 1 except for a plurality of waveforms C1 on the most advanced side of the end mill main body 1. The size is different for each interval equal to the axis O direction. For example, in a roughing end mill in which the diameter of the corrugated outer peripheral blade 7 (the diameter of the circle formed by the peak B protruding toward the outer periphery of the end mill body 1 between the valley bottoms A adjacent to the axis O direction around the axis O) is 10 mm or more, the valley bottom. The pitch between A is formed so as to increase at intervals of about 10 mm from the tip of the corrugated outer peripheral blade 7 (the outer peripheral end of the bottom blade 6).

However, the most advanced first plurality of waveforms C1 of the end mill main body 1 are adjacent to the rear end side in the axis O direction because the length in the axis O direction is limited by the formation of the bottom blade 6. The intervals to the valley bottom A on the tip side of the end mill main body 1 of the plurality of waveforms C2 of 2 are different. Further, when the positions of the rear ends of the plurality of corrugated outer peripheral blades 7 in the axis O direction are aligned, the intervals of the fourth plurality of waveforms C4 on the rearmost end side are also different between the plurality of corrugated outer peripheral blades 7. It becomes a thing. The fourth plurality of waveforms C4 on the rearmost end side may extend in a range exceeding 10 mm.

Further, in the present embodiment, at least one group of the plurality of waveforms of the corrugated outer peripheral blades 7 has a cross section along the axis O of the rotation locus around the axis O at the mountaintop portion B on the outer peripheral side of the end mill main body 1. It is provided with a straight line portion 7a extending in a straight line parallel to the above. That is, the roughing end mill of the present embodiment is a roughing end mill with a nick.

Specifically, in the present embodiment, the cross section of the curve outer peripheral blade 7 along the axis O of the rotation locus around the axis O of each curve is from the front end side to the rear end side of the end mill main body 1 as shown in FIG. Alongward, the valley bottom A portion has a concave curved shape that is recessed toward the inner peripheral side of the end mill body 1, and the mountaintop portion B side has a convex curved shape that is in contact with the valley bottom A portion and is convex toward the outer peripheral side of the end mill main body 1. Then, after forming a straight line portion 7a parallel to the axis O, it is formed into a convex curved shape that is convex toward the outer peripheral side of the end mill body 1 again, and is formed so as to be in contact with the next concave curved valley bottom A portion. By adjusting the length of the straight line portion 7a in the axis O direction, the pitch between the valley bottoms A of the curves adjacent to the axis O direction is set to be different for each of the plurality of waveforms.

Further, in the present embodiment, among the plurality of corrugated outer peripheral blades 7, each of a plurality of waveforms in the second to fifth corrugated outer peripheral blades 7B to 7E excluding the reference first corrugated outer peripheral blade 7A. Of these, the waveform on the rear end side of the end mill body 1 is the plurality of waveforms that adjust the distance in the axis O direction from the valley bottom A on the front end side to the valley bottom A on the rear end side in the end mill body 1 of these plurality of waveforms. The interval adjusting blades 7t have different pitches, and as described above, the phase of the valley bottom A on the tip side of the end mill body 1 having a plurality of waveforms is directed toward the side opposite to the end mill rotation direction T by the interval adjusting blade 7t. It is displaced at equal intervals toward the tip side of the main body 1.

For example, as described above, the pitch P1 between the valley bottoms A of the first plurality of waveforms C1 on the most tip side in the end mill main body 1 of the waveform outer peripheral blade 7 is 1.5 mm, and in the next second plurality of waveforms C2. When the pitch P2 between the valley bottoms A is 1.6 mm, the amount of phase shift between the valley bottoms A in the first waveform C1 adjacent to the circumferential direction of the five corrugated outer peripheral blades 7A to 7E is 1.5 mm / 5 = 0.3 mm, and the amount of phase shift between the valley bottoms A in the second waveform C2 adjacent in the circumferential direction is 1.6 mm / 5 = 0.32 mm, and the gap between the valley bottoms A of the first waveform C1. If all the pitches P1 are 1.5 mm, the phase of the valley bottom A on the most tip side of the second waveform C2 cannot be shifted by a deviation amount of 0.32 mm.

Therefore, in the present embodiment, the pitch P1 between the valley bottoms A of the first waveform C1 on the tip side of the reference first corrugated outer peripheral blade 7A is set to 1.5 mm, while the first corrugated outer peripheral blade 7A is set to 1.5 mm. Other than the waveforms of the second to fifth parts, the waveform at the end of the first waveform C1 of the outer peripheral blades 7B to 7E, the pitch between the valley bottoms A is the phase between the valley bottoms A in the first and second waveforms C2. As an interval adjusting blade 7t in which the difference in the amount of deviation is reduced by 0.02 mm, the interval in the axis O direction of the first waveform C1 of the second and fifth corrugated outer peripheral blades 7B to 7E is adjusted, and the second waveform is used. The phase of the valley bottom A on the most tip side of C2 is shifted by a deviation amount of 0.32 mm.

Specifically, the pitch PB of the interval adjusting blade 7tB of the first waveform C1 in the second corrugated outer peripheral blade 7B is 1.48 mm, and the interval adjusting blade 7tC of the first waveform C1 in the third corrugated outer peripheral blade 7C has a pitch PB of 1.48 mm. The pitch PC is 1.46 mm, the pitch PD of the first waveform C1 in the fourth corrugated outer peripheral blade 7D is 1.44 mm, and the pitch PD of the first corrugated outer peripheral blade 7E is 1.44 mm, and the interval of the first waveform C1 in the fifth corrugated outer peripheral blade 7E. The pitch PE of the adjusting blade 7tE is 1.42 mm.

Similarly, although not shown, the second to fourth waveforms C2 to C4 of the second to fifth corrugated outer peripheral blades 7B to 7E are also provided with an interval adjusting blade 7t. The interval adjusting blade 7t does not have to be the rearmost end of each waveform C1 to C4, but it is easy to manufacture the rearmost end. Further, if necessary, the first corrugated outer peripheral blade 7A may be provided with an interval adjusting blade 7t.

In the roughing end mill configured in this way, the corrugated outer peripheral blades 7 that are out of phase have the same cross-section along the axis O of the rotation locus around the axis O, except for the interval adjusting blade 7t. Since the phases of the valley bottoms A having the same pitch of the waveforms C1 to C4 are shifted at equal intervals in the axis O direction at the valley bottom A on the most tip side of the end mill body 1, the waveforms C1 to C4 connected to the valley bottom A on the tip side are connected. Therefore, the allowance for the specific corrugated outer peripheral blade 7 does not increase. Therefore, the life of the end mill can be extended because wear does not remarkably progress in such a specific corrugated outer peripheral blade 7 and chipping and chipping are not likely to occur.

Then, in the roughing end mill having the above configuration, in each waveform outer peripheral blade 7, the inner peripheral side of the end mill main body 1 having a waveform adjacent to the axis O direction for each of a plurality of waveforms from the front end side to the rear end side of the end mill main body 1. Since the pitches between the valley bottoms A are different in magnitude and the cutting load acting on each of the plurality of waveforms having different pitches between the valley bottoms A is different, the vibration due to the cutting load can be canceled out. , Chatter vibration can be suppressed. Moreover, since the size of the different pitch is not limited by the number of blades of the corrugated outer peripheral blade 7, the pitch can be made different in a wide range of variations according to the generated vibration, and an excellent vibration damping effect can be obtained. Can be obtained.

Further, in the present embodiment, the pitches between the valley bottoms A on the inner peripheral side of the end mill main body 1 of the corrugated outer peripheral blade 7 are a plurality of pitches from the front end side to the rear end side of the end mill main body 1 except for the interval adjusting blade 7t. It gradually increases with each waveform of. For this reason, at the tip of the end mill body 1 where it is difficult to secure rigidity because it is separated from the shank portion 2 at the rear end of the end mill body 1, the allowance for each waveform of the corrugated outer peripheral blade 7 should be reduced. This makes it possible to reduce the cutting load, so that the occurrence of chatter vibration can be suppressed more reliably.

Further, in this way, the pitch between the valley bottoms A on the inner peripheral side of the end mill main body 1 of the corrugated outer peripheral blade 7 gradually increases for each of a plurality of waveforms from the front end side to the rear end side of the end mill main body 1. In the present embodiment, the pitch between the valley bottoms A on the inner peripheral side of the end mill main body 1 of the corrugated outer peripheral blade 7 has a plurality of waveforms from the front end side to the rear end side of the end mill main body 1 except for the interval adjusting blade 7t. It is gradually increasing with the same size for each. Moreover, the equal size at which the pitch increases is 0.1 mm within the range of less than 0.2 mm. Therefore, it is possible to prevent the allowance for each waveform of the corrugated outer peripheral blade 7 from becoming extremely large while moving toward the rear end side of the end mill main body 1, and it is possible to more reliably prevent chipping and chipping.

Furthermore, in the present embodiment, the pitch between the valley bottoms A on the inner peripheral side of the end mill main body 1 of the corrugated outer peripheral blade 7 is rearward from the tip of the end mill main body 1 except for a plurality of waveforms on the most advanced side of the end mill main body 1. The size is different for each interval (about 10 mm) equal to the axis O direction toward the end side. This also prevents the replacement of individual waveforms of the corrugated outer peripheral blade 7 at the tip of the end mill body 1 whose rigidity is difficult to be secured from becoming large, so that the cutting load on the tip can be reduced. This makes it possible to reliably suppress chatter vibration.

However, the pitch between the valley bottoms A of the corrugated outer peripheral blade 7 does not have to be different at equal intervals in the axis O direction from the front end side of the end mill main body 1 toward the rear end side. For example, in the first plurality of waveforms C1 in the range from the tip of the end mill body 1 to 20.0 mm, the pitch P1 between the valley bottoms A is 1.5 mm, and the second plurality of waveforms in the range up to 10.0 mm on the rear end side. In the waveform C2 of the above, the pitch P2 between the valley bottoms A may be 1.65 mm, and in the third plurality of waveforms C3 on the trailing end side, the pitch P3 between the valley bottoms A may be 1.8 mm.

Further, in the present embodiment, at least one group of the plurality of waveforms of the corrugated outer peripheral blade 7 has a cross section along the axis O of the rotation locus around the axis O parallel to the axis O at the mountaintop portion B on the outer peripheral side of the end mill main body 1. It is provided with a straight portion 7a extending in a straight line. Therefore, when the corrugated outer peripheral blade 7 is formed by grinding the outer peripheral relief surface 8 connected to the side opposite to the end mill rotation direction T of the corrugated outer peripheral blade 7 with a grinding wheel as described above, one grinding wheel is used. Can be formed by using.

However, without providing such a straight line portion 7a on the mountaintop portion B, for example, as in the modified example shown in FIG. 5, at least a group of waveforms of the corrugated outer peripheral blade 7 is along the axis O of the rotation locus around the axis O. In the cross section, gradually projecting toward the outer peripheral side from the valley bottom A on the inner circumference of the end mill main body 1 and then gradually denting toward the inner peripheral side of the end mill main body 1 via the mountaintop portion B on the outer peripheral side of the end mill main body 1. However, the mountaintop portion B may have a convex curve shape that is in contact with the concave curve formed by the valley bottom A portion. Further, the waveform having such a convex curved peak portion B and the waveform having the peak portion B having the straight portion 7a described above may be mixed for each of a plurality of waveforms.

1 End mill body 2 Shank part 3 Cutting edge part 4 Chip discharge groove 5 Gash 6 Bottom blade 7 (7A to 7E) Corrugated outer peripheral blade 7t (7tB to 7tE) Interval adjustment blade 7a Straight part 8 Outer peripheral flank O Axis of end mill body 1 T End mill Rotation direction A Waveform outer peripheral blade 7 valley bottom in cross section along axis O of rotation locus around axis O B Crest of corrugated outer peripheral blade 7 in cross section along axis O of rotation locus around axis O C1 to C4 Multiple waveforms P1 to P4 Pitch between valley bottoms A of waveforms adjacent to the axis O direction excluding the interval adjustment blades 7t of multiple waveforms C1 to C4 PB to PE interval adjustment blades 7tB to 7tE pitch

Claims (7)

A plurality of chip discharge grooves extending toward the rear end side are formed on the outer periphery of the tip of the end mill body rotated around the axis at intervals in the circumferential direction, and the wall surface of these chip discharge grooves facing the end mill rotation direction. On the outer peripheral side ridge, a corrugated outer peripheral blade that is uneven from the tip of the end mill body toward the rear end side on the inner peripheral side and the outer peripheral side shifts the phase of the corrugated outer peripheral blade for each of a plurality of chip discharge grooves. It is a roughing end mill formed by
In each of the corrugated outer peripheral blades, the pitch between the valley bottoms on the inner peripheral side of the end mill main body of the waveform adjacent to the axial direction is different for each of a plurality of waveforms from the front end side to the rear end side of the end mill main body. At least a part of the corrugated outer peripheral blades is in the axial direction from the valley bottom on the front end side to the valley bottom on the rear end side in the end mill main body of the plurality of waveforms of the at least a part of the corrugated outer peripheral blades. It is equipped with an interval adjusting blade having a pitch different from that of the plurality of waveforms for adjusting the interval.
In the waveform outer peripheral blades whose phases are shifted, the phase of the valley bottom on the tip side of the end mill body among the plurality of waveforms having the same pitch is shifted at equal intervals in the axial direction by the spacing adjusting blade. A roughing end mill that features that. The pitch between the valley bottoms on the inner peripheral side of the end mill main body of the corrugated outer peripheral blade is characterized in that, except for the interval adjusting blade, the pitch gradually increases for each of a plurality of waveforms from the front end side to the rear end side of the end mill main body. The roughing end mill according to claim 1. The pitch between the valley bottoms on the inner peripheral side of the end mill main body of the corrugated outer peripheral blade gradually increases with the same magnitude for each of a plurality of waveforms from the front end to the rear end side of the end mill main body, except for the interval adjusting blade. The roughing end mill according to claim 2, wherein the roughing end mill becomes. The pitch between the valley bottoms on the inner peripheral side of the end mill main body of the corrugated outer peripheral blade is in a range of less than 0.2 mm for each of a plurality of waveforms from the front end side to the rear end side of the end mill main body, except for the interval adjusting blade. The roughing end mill according to claim 2 or 3, wherein the size of the roughing end mill gradually increases in size. The pitch between the valley bottoms on the inner peripheral side of the end mill body of the corrugated outer peripheral blade is in the axial direction from the tip end side of the end mill body toward the rear end side, except for a plurality of waveforms on the most tip side of the end mill body. The roughing end mill according to any one of claims 1 to 4, wherein the roughing end mills have different sizes at equal intervals. The plurality of waveforms of at least a group of the corrugated outer peripheral blades are linear portions having a cross section of a rotation locus around the axis extending linearly parallel to the axis at the peak portion on the outer periphery side of the end mill main body. The roughing end mill according to any one of claims 1 to 5, wherein the roughing end mill is provided. The plurality of waveforms of at least a group of the corrugated outer peripheral blades gradually project toward the outer peripheral side from the valley bottom of the inner circumference of the end mill body toward the rear end side in a cross section of the rotation locus around the axis along the axis. The roughing end mill according to any one of claims 1 to 6, wherein the end mill body is gradually recessed toward the inner peripheral side of the end mill body via a mountain peak on the outer peripheral side.

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