JP3171791U - End mill - Google Patents

Abstract

An end mill with reduced overall vibration and high cutting speed is provided. SOLUTION: First to third outer peripheral blades 14 to 16 provided around an axis, and first to third bottom blades 11 to 13 provided at end portions of the outer peripheral blades 14 to 16, respectively. The first to third cutting edges 17 to 19 are provided to form an end mill. The angle α1 formed by the first outer peripheral blade 14 and the second outer peripheral blade 15 at the respective axial front ends with respect to the shaft center is 115 degrees to 2 degrees, and the second outer peripheral blade 15 and the third outer peripheral edge. An angle α2 formed with the blade 16 is set to 120 ° to 2 °, and an angle α3 formed between the third outer peripheral blade 16 and the first outer peripheral blade 14 is set to a range of 125 ° to 2 °. Furthermore, the twist angle of the first outer peripheral blade 14 is 41 ° to 1 °, the twist angle of the second outer peripheral blade 15 is 43.5 ° to 1 °, and the twist angle of the third outer peripheral blade 16 is 44.5 °. The radius of the core thick circle 20 was set to a range of 0.35 to 0.65 of the end mill cutting radius. [Selection] Figure 1

Description

The present invention relates to an end mill having three cutting edges with different torsion angles with respect to an axis to improve cutting performance.

Patent Document 1 discloses an end mill having four or more cutting edges each composed of a bottom blade and an outer peripheral blade with a twist angle, the cutting blades being arranged at unequal division points in the circumferential direction, There has been proposed an anti-vibration end mill for the purpose of suppressing the resonance and further improving the processing accuracy.

JP 2011-20193 A

Certainly, in the end mill described in Cited Document 1, noise and the like during cutting were reduced, but when a titanium alloy was cut using an end mill having a diameter of 10 mm, the cutting speed was 50 cm / min to 125 cm / There was a problem of being slow with min.

In addition, although the material of the cited reference 1 is a titanium alloy, when an aluminum alloy was cut using a normal four-blade end mill, the rotation speed was about 1000 mm / min to about 2000 mm / min at 10,000 rpm.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an end mill having a high cutting speed as a matter of course to reduce the overall vibration.

The end mill according to the first device that meets the above object includes first to third outer peripheral blades provided around an axis, and first to first end portions provided at end portions of the first to third outer peripheral blades, respectively. In an end mill having first to third cutting edges with a third bottom edge,
The angle α1 formed between the first outer peripheral blade and the second outer peripheral blade, which is at the axial tip portion with respect to the axial center, is 115 ° ± 2 °, the second outer peripheral blade and the third outer blade The angle α2 formed with the outer peripheral blade is 120 ° ± 2 °, the angle α3 formed with the third outer peripheral blade and the first outer peripheral blade is in the range of 125 ° ± 2 °, and the first outer peripheral blade is twisted. The angle is 41 ° ± 1 °, the twist angle of the second outer peripheral blade is 43.5 ° ± 1 °, and the twist angle of the third outer peripheral blade is 44.5 ° ± 1 °,
In addition, the radius of the core thick circle is set in the range of 0.35 to 0.65 of the cutting radius of the end mill.

Further, the end mill according to the second device is the end mill according to the first device, wherein the first to third cutting edges are radially outward with respect to a tangent line passing through the first to third outer peripheral blades. First to third flank surfaces of 8 to 15 degrees are formed, and the tangent line is disposed on the front side of the first to third flank surfaces including the first to third outer peripheral blades. In contrast, a short blade edge forming surface having a width of 0.05 to 0.5 mm is formed in an angle range of 0.6 to 1.4 degrees.

An end mill according to a third device is the end mill according to the second device, wherein the first to third outer peripheral blades are formed on the inner side in the rotation direction of the first to third cutting blades. 3 scooping surfaces are respectively formed, and the corresponding first scooping surface and the first flank surface, the second scooping surface and the second flank surface, and the third scooping surface, respectively. The angle of the third flank is in the range of 70 to 88 degrees.

And the end mill which concerns on 4th invention is the end mill which concerns on 1st-3rd invention, This end mill is any one of copper, a copper alloy, aluminum, an aluminum alloy, titanium, a titanium alloy, iron, and an iron alloy. Made of cemented carbide and its diameter d is in the range of 5-30 mm.
In the present invention, the core thick circle means a portion serving as an axis of the end mill, that is, a cylindrical portion (core) having a maximum diameter.

In the end mills according to the first to fourth devices, the angle α1 formed between the first outer peripheral blade and the second outer peripheral blade at the front end in the axial direction with respect to the axial center is 115 ° ± 2 °, Since the angle α2 formed between the outer peripheral blade 2 and the third outer peripheral blade is 120 ° ± 2 °, and the angle α3 formed between the third outer peripheral blade and the first outer peripheral blade is 125 ° ± 2 °, The period when the first to third cutting edges cut the material is not constant, and this makes it possible to reduce noise generated by resonance.
The twist angle of the first outer peripheral blade is 41 degrees ± 1 degree and the twist angle of the second outer peripheral blade is 43.5 degrees ± 1. The twist angle of the third outer peripheral blade is different from each other in the range of 44.5 degrees ± 1 degree, so there is no vibration and the time for the outer peripheral blade to come into contact with the material is extended, thereby increasing the cutting speed. it can. In this case, since the radius of the core thick circle is in the range of 0.35 to 0.65 of the cutting radius of the end mill, the length of the cutting edge in the radial direction is secured to improve the discharge performance of the cutting waste, and the end mill itself It is possible to give a strong load to the arm and to apply a strong load by lateral feed.

In particular, the end mill according to the second device has a first to third angle of 8 to 15 degrees with respect to a tangent line passing through the first to third outer peripheral edges, radially outward of the first to third cutting edges. Each of the flank surfaces is formed, and the first to third flank surfaces including the first to third outer peripheral blades have an angle range of 0.6 to 1.4 degrees with respect to the tangent line. Since the short blade edge forming surface with a width of 0.05 to 0.5 mm is formed, the overall blade angle of the outer peripheral blade is made smaller to improve the discharge performance of cutting waste and the like. The tip angle is increased so that the cutting load can be increased.

And the end mill which concerns on 3rd invention has the 1st-3rd scoop surface which forms the 1st-3rd outer periphery edge in the rotation direction inside of the 1st-3rd cutting edge, and The angles of the corresponding first scooping surface and first flank, second scooping surface and second flank, and third scooping surface and third flank are in the range of 70 to 88 degrees. As a result, chips are discharged efficiently and a higher cutting speed can be provided.
As a result of cutting the aluminum material using the end mill according to the third device, it was possible to cut at a feed rate of at least about 4 to 5 times that of the conventional four-blade end mill.

It is sectional drawing of the end mill which concerns on one embodiment of this invention. It is a front view of the end mill. It is a partial enlarged front view of the end mill. It is an expansion explanatory view of the end mill.

Next, embodiments of the present invention will be described with reference to the accompanying drawings.
As shown in FIGS. 1 to 3, the end mill 10 according to an embodiment of the present invention is entirely made of a cemented carbide material, and the first to third bottom blades 11 to 13 are provided at the axial tip portion. First to third cutting edges 17 to 19 having first to third outer peripheral edges 14 to 16 around an axis m are provided around the axis. In addition, the 1st-3rd bottom blades 11-13 are each formed in the front side edge part of the 1st-3rd outer periphery blades 14-16.

As shown in FIGS. 1 and 4, in the end mill 10, an angle formed by the first outer peripheral blade 14 and the second outer peripheral blade 15 that are respectively positioned at the tip end in the axial direction with respect to the axial center m. α1 is 115 ° ± 2 °, and the angle α2 formed between the second outer peripheral blade 15 and the third outer peripheral blade 16 is 120 ° ± 2 °, and the angle formed between the third outer peripheral blade 16 and the first outer peripheral blade 14. α3 is in the range of 125 ° ± 2 °. Further, the twist angle β1 of the first outer peripheral blade 14 is 41 degrees ± 1 degree, the twist angle β2 of the second outer peripheral blade 15 is 43.5 degrees ± 1 degree, and the twist angle β3 of the third outer peripheral blade 16 is 44. The range is 5 ° ± 1 °. The radius of the core thick circle 20 is in the range of 0.35 to 0.65 (more preferably 0.38 to 0.45) of the end mill 10 cutting radius. If the diameter of the core thick circle is excessively increased, the cutting waste is deteriorated. If the diameter of the core thick circle is excessively decreased, the load when the end mill 10 is laterally fed is decreased, and the cutting speed cannot be improved.

The first to third bottom blades 11 to 13 of the end mill 10 are on the same plane as the known end mill bottom blades and have a polishing surface that can be cut with a grindstone.
And in the radial direction outer side of the 1st-3rd cutting blades 17-19 connected to these 1st-3rd bottom blades 11-13, as shown to FIG. 1, FIG. 3, 1st-3rd First to third flank surfaces 21 to 23 of 8 to 15 degrees are formed with respect to the tangent t of the outer peripheral blades 14 to 16, respectively. Here, the tangent t is a line segment perpendicular to the radial line r connecting the first to third outer peripheral blades 14 to 16 and the axis m.

And in the front side of the 1st-3rd flank 21-21 containing this 1st-3rd outer periphery blades 14-16, it is an angle range of 0.6-1.4 degree | times with respect to the tangent t. A short blade edge forming surface 24 having a width w of 0.05 to 0.5 mm is formed (see a partially enlarged view of FIG. 1).

In the end mill 10, the first to third scooping surfaces 26 to 28 forming the first to third outer peripheral blades 14 to 16 are respectively arranged on the inner side in the rotation direction of the first to third cutting edges 17 to 19. Is formed. The angles of the corresponding first scooping surface 26 and first flank 21, second scooping surface 27 and second flank 22, and third scooping surface 28 and third flank 23 are respectively , 70 to 88 degrees (more preferably 78 to 85 degrees). As a result, the first to third outer peripheral blades 14 to 16 having a sharp tip portion close to 90 degrees can be formed, and further, the cutting scraps cut by the first to third outer peripheral blades 14 to 16 are first to first. The third scooping surfaces 26 to 28 can be discharged to the outside.

The first to third torsion grooves 30 to 32 formed by cutting the first to third cutting edges 17 to 19 around the core thickness circle 20 continuously to the first to third scooping surfaces 26 to 28. Is formed. Between the first to third torsion grooves 30 to 32 and the third, first and second flank surfaces 23, 21 and 22, first to third step portions 34 to 36 are provided, The formation area of the flank faces of the first to third flank faces 21 to 23 is clarified. As shown in FIG. 2, the upper portions of the first to third cutting edges 17 to 19 are columnar shanks 38.

Since it becomes the above structures, the surface orthogonal to the end mill 10 can be ground by the 1st-3rd bottom blade 11-13 of this end mill 10 to a plane. And the 1st-3rd outer peripheral blades 14-16 can grind the side surface which the end mill 10 contacts, and by rotating the end mill 10, the 1st-3rd outer peripheral blades 14-16 are to-be-cut object ( For example, aluminum, aluminum alloy, copper, copper alloy, titanium, titanium alloy, iron, iron alloy) are abutted and cut. The cutting scraps are scraped up and discharged by the twisted first to third scooping surfaces 26 to 28.

Although the diameter d of the shank 38 of the end mill 10 is 5 to 30 mm, other diameters can be used.
When the end mill 10 having a diameter of 10 mm was used to grind the aluminum material, the cutting depth was 10 mm, the rotation speed was 12000 rpm, and the cutting speed was about 10,000 mm / min.

The actually cut end mill 10 is positioned at the tip end in the axial direction with respect to the axis m, and the angle α1 formed by the first outer peripheral blade 14 and the second outer peripheral blade 15 is 115 degrees, and the second outer peripheral edge The angle α2 formed by the blade 15 and the third outer peripheral blade 16 is 120 degrees, and the angle α3 formed by the third outer peripheral blade 16 and the first outer peripheral blade 14 is 125 degrees. The twist angle β1 was 41 degrees, the twist angle β2 of the second outer peripheral blade 15 was 43.5 degrees, and the twist angle β3 of the third outer peripheral blade 16 was 44.5 degrees, but for the angles α1 to α3, ± In the range of 2 degrees, the torsional angles β1 to β3 of the first to third outer peripheral blades 14 to 16 were not significantly different even if they were changed in the range of ± 1 degree.

In addition, as described above, the end mill 10 according to the present invention is such that the first to third outer peripheral blades 14 to 16 have unequal leads and unequal pitches, so that the blade resonance phenomenon does not occur during cutting. Accordingly, the end mill is quiet and has high cutting efficiency.
The end mill according to the present invention is not limited to the above embodiment, and the size and shape can be changed without departing from the gist of the present invention.

10: End mill, 11: First bottom blade, 12: Second bottom blade, 13: Third bottom blade, 14: First outer peripheral blade, 15: Second outer peripheral blade, 16: Third outer peripheral blade Blade: 17: First cutting edge, 18: Second cutting edge, 19: Third cutting edge, 20: Heart thickness circle, 21: First flank, 22: Second flank, 23: 3rd flank, 24: cutting edge forming surface, 26: 1st scooping surface, 27: 2nd scooping surface, 28: 3rd scooping surface, 30: 1st twisting groove, 31: 2nd twisting Groove, 32: third torsion groove, 34: first stepped portion, 35: second stepped portion, 36: third stepped portion, 38: shank

Claims (4)

1st-1st provided with the 1st-3rd outer periphery blade provided in the surroundings of an axial center, and the 1st-3rd bottom blade provided in the edge part of this 1st-3rd outer periphery blade, respectively. In an end mill having 3 cutting edges,
The angle α1 formed between the first outer peripheral blade and the second outer peripheral blade, which is at the axial tip portion with respect to the axial center, is 115 ° ± 2 °, the second outer peripheral blade and the third outer blade The angle α2 formed with the outer peripheral blade is 120 ° ± 2 °, and the angle α3 formed with the third outer peripheral blade and the first outer peripheral blade is in the range of 125 ° ± 2 °, and the first outer peripheral blade is twisted. The angle is 41 ° ± 1 °, the twist angle of the second outer peripheral blade is 43.5 ° ± 1 °, and the twist angle of the third outer peripheral blade is 44.5 ° ± 1 °,
Moreover, the end mill is characterized in that the radius of the core thick circle is in the range of 0.35 to 0.65 of the cutting radius of the end mill. 2. The end mill according to claim 1, wherein the first to third cutting edges are radially outward of the first to third cutting edges at a first to third angle of 8 to 15 degrees with respect to a tangent line passing through the first to third outer peripheral cutting edges. Each of the flank surfaces is formed, and on the front side of the first to third flank surfaces including the first to third outer peripheral blades, 0.6 to 1.4 degrees with respect to the tangent line. An end mill characterized in that a short cutting edge forming surface having a width of 0.05 to 0.5 mm is formed in an angle range. 3. The end mill according to claim 2, wherein first to third scooping surfaces that form the first to third outer peripheral blades are formed on the inner side in the rotation direction of the first to third cutting blades, respectively. The angles of the corresponding first scooping surface and the first flank, the second scooping surface and the second flank, and the angles of the third scooping surface and the third flank are: End mill characterized by being in a range of 70 to 88 degrees. The end mill according to any one of claims 1 to 3, wherein the end mill is for cutting any one of copper, copper alloy, aluminum, aluminum alloy, titanium, titanium alloy, iron and iron alloy. An end mill comprising a super hard material and having a diameter d in the range of 5 to 30 mm.

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