JP2002273612A - Roughing end mill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out stable cutting work with a roughing end mill provided with a plurality number of torsional grooves on a tool main body and provided with an outer peripheral cutting edge a crest part and a trough part of which are made into a continuous wave form on an outer periphery of the tool main body on the rear side in the rotating direction from each of the torsional grooves. SOLUTION: A radius of curvature R1 on the tool head end side on the crest part of the outer peripheral cutting edge is made smaller than a radius of curvature R2 on the tool rear end side in the case when the outer peripheral cutting edge has a right edge torsional to the right, and the radius of curvature R1 on the tool head end side on the crest part of the outer peripheral cutting edge is made larger than the radius of curvature R2 on the too rear end side in the case when the outer peripheral cutting edge has the right edge torsional to the left on the roughing end mill provided with a plurality number of the torsional grooves 11 on the tool main body 10 and provided with the outer peripheral cutting edge 12 the crest part 12a and the trough part 12b of which are made into a continuous wave form on the outer periphery of the tool main body on the rear side in the rotating direction from each of the torsional grooves as well as provided with a plurality number of the torsional grooves on the tool main body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a wavy shape in which a plurality of torsion grooves are provided in a tool body, and a crest and a valley are continuous on the outer periphery of the tool body on the rear side in the rotation direction from each torsion groove. According to the roughing end mill provided with the outer peripheral cutting edge, in particular, by improving the shape and arrangement of the corrugated outer peripheral cutting edge having continuous peaks and valleys, cutting by reducing cutting resistance during cutting. It is characterized in that the performance is enhanced and the outer peripheral cutting edge is prevented from being chipped.

[0002]

2. Description of the Related Art Conventionally, in performing rough cutting of a metal material or the like, a plurality of torsion grooves 11 are provided in a tool body 10 as shown in FIG. On the outer periphery of the main body 10, a peak 12
A roughing end mill provided with a corrugated outer peripheral cutting edge 12 in which a and a valley 12b are continuous has been used.

Here, in such a roughing end mill, a ridge 12a and a valley 12
In order to provide the corrugated outer peripheral cutting edge 12 continuous with the outer peripheral cutting edge 12, as shown in FIG.
The radius of curvature R1 on the tool tip side and the radius of curvature R2 on the tool rear end side of the peak 12a are formed to be the same.

However, as described above, the peaks 1 of the outer peripheral cutting edge 12 are
When the radius of curvature R1 on the tool front end side and the radius of curvature R2 on the tool rear end side in 2a are formed to be the same, the outer peripheral cutting edge 1
In the roughing end mill as shown in FIG. 1 in which the right cutting edge 2 is twisted right, the true rake angle becomes a positive rake angle from the center of the peak 12a of the outer peripheral cutting edge 12 to the tool tip side. The true rake angle became smaller toward the tool rear end side from the center of 12a, and eventually became a negative rake angle, and the cutting resistance during cutting increased.

Although not shown, in a roughing end mill in which the outer peripheral cutting edge 12 is right-handed and left-handed, the true rake angle is positive on the tool rear end side from the center of the ridge 12a of the outer peripheral cutting edge 12. The true rake angle became smaller from the center of the peak 12a toward the tool tip, and eventually became a negative rake angle, and the cutting force increased.

As a result, the cutting performance deteriorates in both the roughing end mill in which the outer peripheral cutting edge 12 has a right-handed right twist and the roughing end mill in which the outer peripheral cutting edge 12 has a right-handed left twist. There has been a problem that chatter occurs during cutting and the outer peripheral cutting edge 12 is chipped.

In the conventional roughing end mill, the twist direction of the above-mentioned twist groove 11 and the peak 12a
And the valley portion 12b are arranged so that the torsion direction of the arrangement of each of the outer peripheral cutting blades 12 having a continuous wave shape is in the same direction.
In a roughing end mill as shown in FIG. 1 in which the outer peripheral cutting edge 12 has a right-handed right-hand twist, the ridge 12a of the first outer peripheral cutting edge 12 on the distal end side of the tool main body 10 extends from the rear end side of the tool main body 10 to the rear end side. As shown in FIG. 3, the feed amount per rotation is set to γ, and after cutting with the _first outer peripheral cutting edge 121, the tool body 10 is cut toward the rear end side. when cutting portions located in the second peripheral cutting edge 12 ₂ of the following, is cut in the crest portions 12a of the tool tip side a true rake angle of the second peripheral cutting edge 12 ₂ becomes positive rake angle While the cutting area is reduced, the true rake angle is reduced and the area to be cut at the peak 12a on the rear end side of the tool with poor cutting properties is increased, the cutting resistance in cutting is further increased, and the cutting performance is further improved. There was a problem of lowering.

Although not shown, in a roughing end mill in which the outer peripheral cutting edge 12 is right-handed and left-handed, the roughing end mill is opposite to the above roughing end mill in which the outer peripheral cutting edge 12 is right-handed and right-handed. Then, the cutting is performed in order from the peak 12a of the outer peripheral cutting edge 12 on the rear end side of the tool body 10 toward the front end side of the tool body 10, and the feed amount per rotation is set to γ. after cutting the outer peripheral cutting edge 12 _1, when cutting the outer peripheral cutting edge 12 ₂ of the second next positioned on the distal end side of the tool body 10, the tool rear side the true rake angle becomes positive rake angle The area to be cut at the peak 12a becomes smaller, while the true rake angle becomes smaller and the area to be cut becomes larger at the peak 12a at the tip end of the tool, which has poor machinability, and the cutting resistance during cutting further increases. And cutting performance There has been a problem of a decrease in La.

Further, in the conventional roughing end mill, the ridge 12a of the outer peripheral cutting edge 12 is honed in order to increase the strength of the ridge 12a of the outer peripheral cutting edge 12. Valley 1 of blade 12
In the case of 2b, there is a problem that the valley 12b is chipped.

[0010]

SUMMARY OF THE INVENTION According to the present invention, a plurality of torsion grooves are provided in a tool body, and a wave having continuous peaks and valleys is formed on the outer periphery of the tool body at the rear side in the rotation direction from each of the torsion grooves. An object of the present invention is to solve the above-described problem in a roughing end mill provided with a shaped outer peripheral cutting edge.

That is, according to the present invention, in the roughing end mill as described above, the shape and arrangement of the corrugated outer peripheral cutting edges in which the peaks and the valleys are continuous are improved, and the cutting resistance during cutting is reduced. An object of the present invention is to improve cutting performance, prevent chattering during cutting, and prevent the outer peripheral cutting edge from being chipped, so that stable cutting can be performed.

[0012]

In the first roughing end mill according to the present invention, in order to solve the above-mentioned problems, a plurality of torsion grooves 11 are provided in a tool body 10 and each of the torsion grooves 11 is rotated by each of the torsion grooves 11. A peak 12a and a valley 12b are formed on the outer periphery of the tool body 10 on the rear side in the direction.
In a roughing end mill provided with an outer peripheral cutting edge 12 having a continuous wave shape, when the outer peripheral cutting edge 12 is right-handed and right-hand twisted, the curvature of the tool tip side at the peak 12a of the outer peripheral cutting edge 12 is set. The radius R1 is made smaller than the radius of curvature R2 on the tool rear end side.

When the outer peripheral cutting edge 12 has a right edge and a right twist, as in the first roughing end mill of the present invention, the radius of curvature R1 on the tool tip side of the peak 12a of the outer peripheral edge 12 is determined after the tool. When the radius of curvature R2 is smaller than the radius of curvature R2 on the end side, the radius of curvature R1 on the tool tip side and the radius of curvature R2 on the tool rear end side of the peak 12a of the outer peripheral cutting edge 12 are the same as in the conventional case. Outer cutting edge 12
The true rake angle is further increased on the tool tip side from the center of the peak 12a, and the decrease of the true rake angle from the center of the peak 12a toward the tool rear end is suppressed. The cutting performance is improved by reducing the resistance, and chattering during cutting and chipping of the outer peripheral cutting edge 12 are prevented.

In the second roughing end mill according to the present invention, in order to solve the above-mentioned problems, a plurality of torsion grooves 11 are provided in the tool body 10, and the torsion groove 11 is provided on the rear side in the rotation direction with respect to each of the torsion grooves 11. In a roughing end mill in which a corrugated outer peripheral cutting edge 12 in which a peak portion 12a and a valley portion 12b are continuously provided on the outer periphery of the tool main body 10, when the outer peripheral cutting edge 12 has a right-handed left-handed twist, The radius of curvature R1 at the tip of the tool at the peak 12a of the outer peripheral cutting edge 12 is set to be larger than the radius of curvature R2 at the rear of the tool.

As in the second roughing end mill of the present invention, when the outer peripheral cutting edge 12 is right-handed and left-handed, the radius of curvature R1 on the tool tip side of the ridge 12a of the outer peripheral cutting edge 12 is determined after the tool. When the radius of curvature R2 is larger than the radius of curvature R2 on the end side, the radius of curvature R1 on the tool tip side and the radius of curvature R2 on the tool rear end side of the peak 12a of the outer peripheral cutting edge 12 are the same as in the conventional case. Outer cutting edge 12
The true rake angle is further increased from the center of the ridge 12a to the tool rear end side from the center of the ridge 12a, and the decrease in the true rake angle from the center of the ridge 12a toward the tool tip side is suppressed. The cutting performance is improved by reducing the resistance, and chattering during cutting and chipping of the outer peripheral cutting edge 12 are prevented.

In the first and second roughing end mills, the twist direction of the twist groove 11 and the twist of the arrangement of the corrugated outer peripheral cutting edges 12 in which the peaks 12a and the valleys 12b are continuous. In the first roughing end mill in which the outer peripheral cutting edge 12 has a right-handed right-handed twist when the direction is set to be opposite to the direction, the tool main body 10 is cut from the peak 12a of the outer peripheral cutting edge 12 on the rear end side of the tool main body 10. 10 is gradually cut toward the tip end side, and the true rake angle is increased, and the crest 1 on the tool tip end side with high machinability.
In 2a, the area to be cut is increased, and the cutting resistance during cutting is further reduced, so that the cutting performance is further improved. On the other hand, in the second roughing end mill in which the outer peripheral cutting edge 12 is right-handed and left-handed, the tip of the tool body 10 is opposite to the case of the above roughing endmill in which the outer peripheral cutting edge 12 is right-handed and right-handed. Is gradually cut from the peak 12a of the outer peripheral cutting edge 12 toward the rear end side of the tool body 10 on the side, the true rake angle increases, and the peak on the tool rear end side with high cutting performance. In 12a, the area to be cut becomes large, the cutting resistance during cutting is further reduced, and the cutting performance is further improved.

In the first and second roughing end mills described above, when the entire outer peripheral cutting edge 12 having a wave shape in which the peak 12a and the valley 12b are continuous is subjected to honing,
The strength of the outer peripheral cutting edge 12 is improved as a whole, and it is suppressed that the peak 12a of the outer peripheral cutting edge 12 is chipped during cutting, or that chips are hit against the valley 12b of the outer peripheral cutting blade 12 and the valley 12b is chipped. Become like

When honing the entire outer peripheral cutting edge 12 as described above, if the honing width is small, the strength of the outer peripheral cutting edge 12 cannot be sufficiently improved, while if the honing width is too large, Since the cutting resistance becomes large and chatter easily occurs during cutting, the honing width at the top of the peak 12a is set to 0.00.
It is preferable to set the range of 3 to 0.020 mm.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A roughing end mill according to an embodiment of the present invention will be specifically described below with reference to the accompanying drawings.

Also in the roughing end mill according to this embodiment, as shown in FIG. 1, a plurality of torsion grooves 11 are provided in the tool body 10, and a mountain is formed on the outer periphery of the tool body 10 on the rear side in the rotational direction from each of the torsion grooves 11. Part 12
The outer peripheral cutting edge 12 having a right-handed and right-twisted wavy shape in which a and the valley 12b are continuous is provided.

In the roughing end mill according to this embodiment, as shown in FIG.
The radius of curvature R1 on the tool tip side at the second peak 12a is smaller than the radius of curvature R2 on the tool rear end side. As described above, when the outer peripheral cutting edge 12 has a right blade right twist, when the radius of curvature R1 on the tool tip side at the peak 12a of the outer peripheral cutting edge 12 is smaller than the radius of curvature R2 on the tool rear end side, The true rake angle is further increased on the tool tip side from the center of the peak 12a of the outer peripheral cutting edge 12, and the decrease of the true rake angle from the center of the peak 12a toward the tool rear end is suppressed, The cutting resistance at the time of cutting is reduced, the cutting performance is improved, and chattering at the time of cutting and chipping of the outer peripheral cutting edge 12 are prevented.

In the roughing end mill according to this embodiment, as shown in FIG. 5, each of the outer peripheral cutting edges 12 having a wave shape in which the twist direction of the above-mentioned twist groove 11 and the peak 12a and the valley 12b are continuous. The twist direction of the arrangement was made opposite.

By doing so, as shown in FIG.
The feed amount per rotation is set to γ, and the first outer peripheral cutting edge 12 ₁
In after cutting, when the portion located on the distal end side of the tool body 10 so as to cut in a second peripheral cutting edge 12 ₂ of the following, the twist direction of the twisted grooves 11, crests 12a and valleys 1
The true rake angle of the _second outer peripheral cutting edge 122 is a positive rake angle as compared with the conventional case in which the twisting direction of the arrangement of the corrugated outer peripheral cutting edges 12 continuous with 2b is opposite. The area to be cut at the peak 12a on the tool tip side becomes larger, while the true rake angle becomes smaller and the area to be cut at the peak 12a at the rear end of the tool, which has poor machinability, becomes smaller. The cutting force in the cutting was further reduced, and the cutting performance was further improved.

Further, in the roughing end mill according to this embodiment, honing is performed on the entire outer peripheral cutting edge 12 having a wave shape in which the peak 12a and the valley 12b are continuous. As described above, when the entire outer peripheral cutting edge 12 is subjected to honing, the strength of the outer peripheral cutting edge 12 is improved as a whole, and the ridges 12a of the outer peripheral cutting edge 12 are chipped at the time of cutting or chips are removed. Chipping of the valley 12b against the valley 12b is suppressed.

Here, as described above, the peak 12a and the valley 1
In honing the entire outer peripheral cutting edge 12 having a wave shape continuous with 2b, a brush honing method using a nylon brush containing SiC or a diamond grindstone can be used.

In this embodiment, the case of the roughing end mill provided with the right-handed right-handed outer peripheral cutting edge 12 has been described. However, the case of the roughing endmill provided with the right-handed left-handed outer peripheral cutting edge 12 has been described. The same effect can be obtained by making the radius of curvature R1 at the tip end of the tool at the peak 12a of the outer peripheral cutting edge 12 larger than the radius of curvature R2 at the rear end of the tool.

[0027]

Next, a roughing end mill according to an embodiment of the present invention is compared with a conventional roughing end mill in which a peak 12a of an outer peripheral cutting edge 12 is formed with a constant radius of curvature. In the roughing end mill according to the embodiment of the present invention, cutting resistance is reduced, chattering during cutting and chipping of the outer peripheral cutting edge are prevented, and stable cutting can be performed.

(Examples 1 and 2 and Comparative Example 1)
In the roughing end mills of Comparative Example 1 and Comparative Example 1, four tool grooves 11 having a right-hand twist having a twist angle of 20 ° were provided on a tool body 10 having a diameter of 12.0 mm and made of a fine-grain cemented carbide. A rake angle of 3 on the outer periphery of the tool body 10 on the rear side in the rotational direction from each torsion groove 11
°, as peripheral relief angle is 6 °, to provide a crest 12a and valley portions 12b and the right edge right twist 4 columns peripheral cutting edge 12 ₁ to 12 ₄ which has become a continuous wave-shaped did.

In the roughing end mill of the first embodiment, the radius of curvature R1 on the tool tip side at the peak 12a of each outer peripheral cutting edge 12 is 0.40 mm, and the radius of curvature R2 on the tool rear end side is 0.50 mm. The radius of curvature R1 on the tip side of the tool in the peak 12a is the radius of curvature R2 on the rear side of the tool.
It was made smaller.

In the roughing end mill according to the second embodiment, the radius of curvature R1 on the tip side of the tool at the peak 12a of each outer peripheral cutting edge 12 is 0.20 mm, and the radius of curvature R2 on the rear end of the tool is 0.70 mm. The radius of curvature R1 on the tip side of the tool at the peak 12a is smaller than the radius of curvature R2 on the rear end side of the tool.

In the roughing end mill of Comparative Example 1, the radius of curvature R1 on the tool tip side and the radius of curvature R2 on the tool rear end side of the ridge 12a of each outer peripheral cutting edge 12 are set to 0.45 mm. did.

In each of the roughing end mills of Examples 1 and 2 and Comparative Example 1, each of the outer peripheral cutting edges 12 having a wavy shape in which the torsion direction of the torsion groove 11 and the peak 12a and the valley 12b are continuous. And the honing was performed on the entire outer peripheral cutting edge 12 so that the honing width at the top of the peak 12a of the outer peripheral cutting edge 12 was 0.005 mm.

[0033] Here, in each of roughing end mill of Examples 1 and 2 and Comparative Example 1, cutting the first mountain portion 12a of the peripheral cutting edge 12 _1, From this the portion located on the distal end side of the tool body 10 Next second outer peripheral cutting edge 12 Peak portion 12 of ₂
a point B of the tool rear side of the second peripheral cutting edge 12 ₂ where the a cross, a portion located on the distal end side of the second peripheral cutting edge 12 ₂ of the ridges 12a and than this tool body 10 in a point a of the tool distal end side of the second peripheral cutting edge 12 ₂ of the third peripheral cutting edge 12 ₃ of crests 12a of the next cutting intersect, true in the second peripheral cutting edge 12 _2, respectively I sought the rake angle.

As a result, as shown in Table 1 below, in the roughing end mill of Example 1, the true rake angle at point A was + 11.2 °, and the true rake angle at point B was -4.9 °. In the roughing end mill of Example 2, the true rake angle at point A was + 14.5 ° and the true rake angle at point B was −4.0 °, whereas the roughing end mill of Comparative Example 1 was used. At point A
The true rake angle at + 10.8 ° and the true rake angle at point B are −5.3 °, and the roughing end mills of Examples 1 and 2 have better results at both points A and B. , The true rake angle was increasing toward the positive. In particular, in the roughing end mill according to the second embodiment in which the difference between the radius of curvature R1 on the tool tip side and the radius of curvature R2 on the tool rear end side at the peak 12a of the outer peripheral cutting edge 12 is increased, the point A
And the true rake angle at point B was even larger in the positive direction.

Then, the above Examples 1 and 2 and Comparative Example 1
In each of the roughing end mills, PV
The coating of TiAlN was performed by Method D.

Next, the above Examples 1 and 2 and Comparative Example 1
The cutting speed of 50 m / m for a work material SKD11 having a Rockwell hardness of 50 using each of the roughing end mills
in, feed rate γ 0.2 mm / rev, radial depth of cut 6.0 mm, axial depth of cut 18 mm, 2 m of cutting work, vibration noise and chattering during cutting are evaluated, and peripheral cutting edge after cutting 12 and the flank wear Vb (mm) were evaluated. The results are shown in Table 1 below.

Here, regarding the evaluation of the vibration sound, the case where there was almost no vibration sound was indicated by ○, the case where there was little vibration sound was indicated by Δ, and the case where the vibration sound was loud was indicated by X.

As for the evaluation of chatter, a case where there was almost no chatter was evaluated as ○, and a case where there was little chatter was evaluated as △,
The case where chatter was large was indicated by x.

Regarding the evaluation of the chipping on the outer peripheral cutting edge 12, the case where no chipping occurred was indicated by ○, and the case where chipping occurred was indicated by ×.

[0040]

[Table 1]

As is apparent from the results, the outer peripheral cutting edge 1
In the roughing end mill in which 2 is a right-handed right-handed twist, each of the roughing end mills of Examples 1 and 2 in which the radius of curvature R1 on the tip side of the tool at the peak 12a of the outer peripheral cutting edge 12 is smaller than the radius of curvature R2 on the rear side of the tool. Is the outer peripheral cutting edge 1
As compared with the roughing end mill of Comparative Example 1 in which the radius of curvature R1 on the tool front end side and the radius of curvature R2 on the tool rear end side of the second crest 12a are the same, generation of vibration noise and chatter during cutting is suppressed. At the same time, the occurrence of chipping on the outer peripheral cutting edge 12 is suppressed, and the flank wear amount Vb is also reduced. In particular, the radius of curvature R1 on the tool tip side and the rear end side of the tool at the peak 12a of the outer peripheral cutting edge 12 are reduced. Radius of curvature R
In the roughing end mill of Example 2 in which the difference from Example 2 was increased, the generation of vibration noise and chatter during cutting was further suppressed, and the flank wear amount Vb was further reduced.

Examples 1.1 to 1.4 Examples 1.1 to 1.4
In 1.4, in the luffing end mill of Example 1 described above, the radius of curvature R1 on the tool tip side at the peak 12a of the outer peripheral cutting edge 12 was 0.40 mm, and the radius of curvature R2 on the tool rear end side was 0.50 mm. In performing honing on the entire outer peripheral cutting edge 12, the honing conditions for the outer peripheral cutting edge 12 were changed, and the honing width at the top of the peak 12 a was changed as shown in Table 2 below. 0.003 mm, 0.013 mm in Example 1.2,
Each luffing end mill was obtained in the same manner as in the case of the above-described luffing end mill of Example 1 except that the diameter was 0.019 mm in Example 1.3 and 0.05 mm in Example 1.4.

The roughing end mills of Examples 1.1 to 1.4 are also used for the work material SKD11 having a Rockwell hardness of 50 in the same manner as in the case of the roughing end mill of Example 1 described above. Cutting speed 50m / m
in, feed 0.2 mm / rev, radial depth of cut 6.0
mm, and a cutting of 2 m under the condition of an axial cut of 18 mm, vibration noise and chatter during cutting are evaluated, and the chipping evaluation and flank wear Vb (mm) of the outer peripheral cutting edge 12 after cutting are evaluated. Investigations and the results are shown in Table 2 below. In the roughing end mill of Example 1.4, the flank wear Vb (mm) was not measured because the outer peripheral cutting edge 12 was largely chipped.

[0044]

[Table 2]

As is apparent from the results, when honing the entire outer peripheral cutting edge 12, the honing width at the top of the peak 12 a of the outer peripheral cutting edge 12 is 0.003 to 0.003.
Example 1, Examples 1.1 to 1.1 in a range of 0.020 mm
In each of the luffing end mills of 1.3, the generation of vibration noise and chatter during cutting was suppressed, and the occurrence of chipping in the outer peripheral cutting edge 12 was also suppressed.
In the roughing end mill of Example 1.5 in which the honing width at the top of the peak 12a of the outer peripheral cutting edge 12 was set to 0.05 mm, vibration noise and chatter during cutting were generated, and the outer peripheral cutting edge 12 was also chipped. Was.

When the honing was not performed on the outer peripheral cutting edge 12 in the roughing end mill of the above-mentioned first embodiment, the outer peripheral cutting edge 1
When the honing was not performed on the outer peripheral cutting edge 12 in the roughing end mill of Comparative Example 1, the outer peripheral cutting edge 12 was chipped immediately after cutting.

Further, in the above embodiment and comparative example, the case of the roughing end mill in which the outer peripheral cutting edge 12 is right-handed and right-handed is described. However, the roughing endmill in which the outer peripheral cutting edge 12 is right-handed and left-handed. Also in the case of the above, the same effect can be obtained when the radius of curvature R1 on the tip end side of the tool at the peak 12a of the outer peripheral cutting edge 12 is larger than the radius of curvature R2 on the rear end side of the tool.

[0048]

As described in detail above, in the first roughing end mill according to the present invention, when the corrugated outer peripheral cutting edge in which the peak and the valley are continuous has a right-hand right twist,
The radius of curvature R1 on the tip side of the tool at the peak of the outer peripheral cutting edge
Is made smaller than the radius of curvature R2 on the tool rear end side, so that the true rake angle is further increased from the center of the peak of the outer peripheral cutting edge to the tool tip side, and goes from the center of the peak to the tool rear end side. The true rake angle is suppressed from decreasing in accordance with, cutting resistance during cutting is reduced, cutting performance is improved, chattering during cutting, and the peripheral cutting edge is prevented from being chipped, and stable cutting is performed. Processing is now possible.

Further, in the second roughing end mill according to the present invention, when the corrugated outer peripheral cutting edge in which the crest and the valley are continuous has a right-handed left-handed twist, the tool tip at the crest of the outermost cutting edge is used. The radius of curvature R1 on the side is made larger than the radius of curvature R2 on the rear end of the tool, so that the true rake angle is further increased from the center of the peak of the outer peripheral cutting edge to the rear end of the tool and from the center of the peak. The reduction of the true rake angle toward the tool tip side is suppressed, cutting resistance during cutting is reduced and cutting performance is improved, preventing chattering and chipping of the outer peripheral cutting edge during cutting. This has enabled stable cutting.

In the first and second roughing end mills according to the present invention, the twisting direction of the twisted groove and the twisting direction of the arrangement of the corrugated outer peripheral cutting edges in which the peaks and valleys are continuous are opposite to each other. As a result, the area to be cut becomes larger at the ridge on the tool tip side where the true rake angle is increased and the cutting performance is high, so that the cutting resistance during cutting is further reduced and the cutting performance is further improved.

Further, in the first and second roughing end mills according to the present invention, when the entire outer peripheral cutting edge in the form of a wave having continuous peaks and valleys is subjected to honing, the overall strength of the outer peripheral cutting edge is increased. The cutting of the peak of the outer peripheral cutting edge during chipping and the chipping of the valley of the outer cutting edge at the valley of the outer peripheral cutting edge are suppressed, and in particular, the honing width at the top of the peak is reduced to 0.003 to 0. When the thickness is in the range of 0.020 mm, the cutting resistance is increased and chattering is less likely to occur during cutting, and the strength of the outer peripheral cutting edge can be sufficiently improved.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of a roughing end mill.

FIG. 2 is a partial explanatory view showing a state of a peak portion of a corrugated outer peripheral cutting edge in a conventional roughing end mill.

FIG. 3 shows a conventional roughing end mill in which the torsion direction of the torsion groove and the torsion direction of the arrangement of each of the outer peripheral cutting blades in the form of a wave having continuous peaks and valleys are the same. FIG. 4 is a partial explanatory diagram showing a state.

FIG. 4 is a partial explanatory view showing a state of a peak of a corrugated outer peripheral cutting edge in the roughing end mill according to the embodiment of the present invention.

FIG. 5 is a view showing a case where the torsion direction of the torsion groove and the torsion direction of the disposition of each peripheral cutting edge having a continuous wave-shaped peak and valley are opposite to each other in the roughing end mill in the embodiment. FIG. 4 is a partial explanatory view showing a state of a cutting portion.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 tool body 11 torsion groove 12 outer peripheral cutting edge 12a outer peripheral cutting edge crest 12b outer peripheral cutting blade crest R1 radius of curvature of tool tip side at peak R2 radius of curvature of tool rear end at peak

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Toshihiro Kitano 2-1-1-18 Kamihigashi, Hirano-ku, Osaka Dai-Jet Industrial Co., Ltd. F-term (reference) 3C022 KK03 KK06 KK28 KK29

Claims (4)

[Claims] A plurality of torsion grooves are provided in a tool body, and a peak portion and a valley portion are provided on an outer periphery of the tool body at a rear side in a rotation direction from each of the torsion grooves.
In a roughing end mill provided with an outer peripheral cutting edge 12 having a continuous wave shape, when the outer peripheral cutting edge 12 is right-handed and right-hand twisted, the curvature of the tool tip side at the peak 12a of the outer peripheral cutting edge 12 is set. A roughing end mill wherein the radius R1 is smaller than the radius of curvature R2 on the rear end side of the tool. 2. A plurality of torsion grooves 11 are provided in the tool main body 10, and a ridge 12a and a valley 12b are formed on the outer periphery of the tool main body 10 on the rear side in the rotation direction from each of the torsion grooves 11.
In a roughing end mill provided with an outer peripheral cutting edge 12 having a continuous wave shape, when the outer peripheral cutting edge 12 has a right-handed left-handed twist, a curvature of a tool tip side of a peak portion 12a of the outer peripheral cutting edge 12 is provided. A roughing end mill wherein the radius R1 is larger than the radius of curvature R2 on the tool rear end side. 3. The roughing end mill according to claim 1, wherein the twist direction of the twist groove 11 and the arrangement of the wave-shaped outer peripheral cutting edges 12 in which the peaks 12a and the valleys 12b are continuous. A roughing end mill characterized in that the direction is opposite to the direction. 4. The roughing end mill according to claim 1, wherein the ridges 12a and the valleys 12b are provided.
A honing width at the top of the ridge 12a is in the range of 0.003 to 0.020 mm.