JP2724120B2 - Reamer for composite material processing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reamer for a composite material for processing an inner peripheral surface of a prepared hole formed in a composite material obtained by laminating a plurality of types of materials including difficult-to-cut materials. .

[0002]

2. Description of the Related Art When processing with a reamer to finish the inner peripheral surface of a prepared hole formed in a composite material formed by laminating a plurality of types of materials including difficult-to-cut materials, a stationary rotary drive or a hand-held device is used. The reamer mounted on the mold rotation drive device is advanced into the prepared hole through the guide bush while being rotationally driven.

[0003]

By the way, a structural material having high corrosion resistance and specific strength such as β-titanium and a titanium alloy is laminated on the above-mentioned composite material. With the conventional reamer 60 shown in FIG. 5, the finished hole accuracy and the finished surface roughness were not sufficiently obtained, and the thickness of the affected layer was not sufficiently reduced. For example, in composite materials used for spoilers, rudder, elevators, etc. for aircraft, for example, β titanium,
CFRP (carbon fiber reinforced resin), aluminum alloy, etc. are laminated via a liquid shim, which is a synthetic resin adhesive with a thickness of about 1 mm. When β titanium is cut, its cutting resistance is extremely large due to its springback action. As a result, there are disadvantages in that the precision of the finished hole and the precision of the inner peripheral surface are reduced by sliding friction under high contact pressure and the entrapment of chips, and the thickness of the deformed layer generated by frictional heat is increased. In the process of transporting the chips generated from the cutting edge, the β titanium or CFR
Since chips come into contact with the liquid shim that bonds P to each other, there is a disadvantage that the inner peripheral diameter of the liquid shim portion is enlarged. Furthermore, the cutting edge is easily worn by cutting β titanium which is a difficult-to-cut material or by cutting CFRP having a high carbon fiber content, so that the life of the reamer is shortened and the carbon fiber is cut at the exit of the hole on the CFRP side. However, there was also a drawback that it was fluffy.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an inner peripheral surface of a pilot hole of a composite material formed by laminating a plurality of types of materials including difficult-to-cut materials. When machining, the accuracy of the finished hole and the inner surface finish is obtained, the thickness of the affected layer is suppressed, the inner diameter of the liquid shim is not enlarged, and the durable life is extended, and the carbon fiber An object of the present invention is to provide a reamer for a composite material that can prevent fluffing.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the gist of the present invention is to provide a shank portion and a cylindrical cutting edge portion, and a plurality of types of materials including difficult-to-cut materials are laminated. In a composite material processing reamer that cuts an inner peripheral surface of a prepared hole formed in a composite material formed by the cutting edge portion, a twist groove that is twisted in a direction opposite to a preset rotation direction toward the tip portion is formed. A biting portion formed on the cutting edge portion and provided with an outer peripheral cutting edge between an inner wall surface and an outer peripheral surface opposed to each other in the rotation direction, and having an outer diameter increasing from the tip of the cutting edge portion toward the shank portion. And a back taper portion whose outer diameter decreases at a rate of 0.05 to 0.25 mm / 100 mm toward the shank portion following the biting portion, is formed in the cutting edge portion, and Outer cutting edge 0.05 adjacent to the opposite direction
That is, a margin portion having a width of 0.20 mm is formed, and a flank of 20 to 30 ° is provided following the margin portion.

[0006]

In this case, the outer diameter is set to 0.05 to 0.25.
An extremely large back taper portion, which is reduced at a rate of 100 mm / 100 mm, is formed following the biting portion, and is 0.05 to 0.
Since a very small margin portion having a width of 20 mm is formed, and a flank having a large angle of 20 to 30 ° is provided following the margin portion, the cutting resistance of the reamer for processing a composite material is suitably reduced. You. Further, as a result of the provision of the flank having a large angle of 20 to 30 °, a space is formed in which the chips generated from the cutting edges are sufficiently accommodated. Does not roughen the finished surface. In addition, since the outer peripheral cutting edge is provided so as to be twisted in a direction opposite to a preset rotation direction toward the distal end portion, chips generated from the biting portion are discharged forward, that is, toward the distal end of the reamer.

The ratio of the back taper is 0.05 mm /
If it is less than 100 mm, the inner peripheral surface of the finishing hole and the back tapered portion are in sliding contact with a high contact pressure due to springback of a difficult-to-cut material such as β titanium, so that it is difficult to obtain a cutting resistance reducing effect. On the other hand, if the ratio of the back taper exceeds 0.25 mm / 100 mm, the gap with the guide bush used at the time of reaming becomes large, and the finished hole accuracy decreases.

When the width of the margin portion exceeds 0.20 mm, the ratio of the back taper is 0.05 mm / 1.
As in the case of less than 00 mm, the inner peripheral surface of the finished hole and the margin are in sliding contact with a high contact pressure due to the springback of difficult-to-cut materials such as β-titanium. It is difficult to be. Further, when the width of the margin portion is less than 0.05 mm, the strength of the outer peripheral cutting edge of the reamer is insufficient, the hole size is enlarged by the bending of the cutting edge, and the dimensional accuracy is reduced.

The clearance angle of the flank following the margin is 2
If the angle is less than 0 °, sufficient space for accommodating chips generated from the cutting edge is not formed, so that the chips are in sliding contact with the inner peripheral surface of the hole and the finished surface becomes rough, and conversely, the clearance of the flank following the margin portion When the angle exceeds 30 °, the strength of the outer peripheral cutting edge of the reamer becomes insufficient, and the bending of the cutting edge increases the hole size, thereby reducing the dimensional accuracy.

[0010] The reamer used in the stationary rotary drive device has a back taper ratio of 0.15 to 0.25 mm.
/ 100 mm, the width of the margin portion is in the range of 0.10 to 0.20 mm, and the clearance angle of the flank following the margin portion is in the range of 25 to 30 °. desirable. The reamer used in the hand-held rotary drive device has a back taper ratio of 0.05 to
0.15 mm / 100 mm, the width of the margin is in the range of 0.05 to 0.15 mm, and the clearance angle of the flank following the margin is 20 to 25 °.
Is preferably within the range. This is because the reamer used for the hand-held rotary drive becomes unstable compared to the reamer used for the stationary rotary drive.

[0011]

Therefore, according to the present invention, an extremely large back taper portion whose outer diameter decreases at a rate of 0.05 to 0.25 mm / 100 mm is formed following the biting portion, and An extremely small margin portion having a width of 0.05 to 0.20 mm is formed adjacent to the outer peripheral cutting edge in the opposite direction, and a flank having a large angle of 20 to 30 ° is provided following the margin portion. As a result, the sliding friction under high contact pressure is reduced, the cutting resistance of the reamer for processing a composite material is suitably reduced, and the flank having a large angle of 20 to 30 ° is provided. Since a space for accommodating chips generated from the air is formed and chip entrapment is suppressed, the accuracy of the finished hole and the accuracy of the inner peripheral surface are increased.
In addition, since the outer peripheral cutting edge is provided so as to be twisted in a direction opposite to a preset rotation direction toward the tip, chips generated from the biting portion are discharged forward, that is, toward the tip of the reamer. In addition, the liquid shim is not shaved by the chips in the process of transporting the chips generated from the cutting edge, thereby preventing the inner peripheral diameter of the liquid shim from being enlarged. Furthermore, even when cutting β titanium, which is a difficult-to-cut material, or cutting CFRP with a high carbon fiber content, the sliding friction under high contact pressure is reduced as described above, so that the cutting edge is less likely to be worn. Since the life of the reamer is prolonged, it is also preferable to prevent the carbon fiber from fluffing at the outlet of the hole on the CFRP side.

Preferably, the twist angle θ of the twist groove is 3 to 15 °, and the axial length L of the biting portion is
Is 2.5 to 3.5 mm, the inclination angle α of the biting portion with respect to the rotation center axis is 8 to 12 °, and the outer diameter D of the reamer is 3.175 to 15.875 mm. According to such a reamer for processing a composite material, the effect of the invention is more remarkable.

Preferably, the reamer body or its outer peripheral cutting edge is made of any one of a high-speed steel, a cemented carbide, and a diamond ultra-high pressure sintered body. More preferably, the surface of the cutting edge of the reamer is titanium (Ti).
And a hard coating made of at least one of aluminum (Al), carbon (C), and nitrogen (N), for example, TiC, TiN, TiAlN, etc., is provided with a thickness of 1 to 5 μm.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a side view of the reamer 10,
One side of the center line is cut away. FIG. 2 is an enlarged view showing the outer shape of the tip surface of the reamer 10.

The reamer 10 is provided, for example, with a pilot hole 16 formed in the composite material 12 and 14 shown in FIGS.
In order to finish the inner peripheral surface of the and 18, it is mounted on a stationary rotary drive or a hand-held rotary drive and is driven to rotate while being axially advanced through its guide ring in its pilot holes 16 and 18. .

The composite material 12 has a two-layer structure in which, for example, β titanium 20 having high corrosion resistance and high specific strength and CFRP (carbon fiber reinforced resin) 22 are adhered to each other by a liquid shim 24 which is a synthetic resin adhesive. Panel material for aircraft. The composite material 14 is a three-layer aircraft panel material formed by sequentially laminating the β titanium 20, the CFRP 22, and the β titanium 20 and bonding them together by the liquid shim 24. The above β titanium 20 and C
The FRP 22 is a plate having a thickness of, for example, about 10 mm.
It is formed to a thickness of about.

The reamer 10 has a cylindrical shape as a whole, and includes a shank portion 30 to be gripped by a chuck device (not shown) and a cutting edge portion 32 on which an outer peripheral cutting edge 40 is formed. The cutting edge portion 32 has five twist grooves 34 which are twisted at a twist angle θ of 5 ° in a direction opposite to a preset rotation direction (clockwise direction) A toward the tip portion at equal intervals in the circumferential direction. The outer peripheral cutting edge 40 is provided on the ridge line between the inner wall surface, ie, the rake face 36, and the outer peripheral surface, ie, more precisely, the margin portion 38, which is formed in the torsion groove 34 and faces the rotation direction A.

The cutting edge 32 has an inclination angle α of about 10 ° with respect to the center line, so that the cutting edge 3
A biting portion 42 whose outer diameter increases as it goes from the tip of 2 to the shank portion 30, and the outer diameter becomes 0.05 to 0.25 as it goes to the shank portion 30 following the biting portion 42.
and a back taper portion 44 that decreases at a rate in the range of mm / 100 mm. The outer cutting edge 40 located at the biting portion 42 functions as a main cutting edge 40a, and the outer cutting edge 40 located at the back taper portion 44 functions as a sub cutting edge 40b. Cutting in the finishing process by the reamer 10 is performed exclusively by the main cutting edge 40a.

As shown in detail in FIG. 2, at the cutting edge portion 32, the rake angle β of the cutting edge located at the biting portion 42 of the outer peripheral cutting edge 40, ie, the main cutting edge 40a, ie, the rotation center C, The angle β between the straight line connecting the main cutting edge 40a and the rake face 36 is formed at about 5 °, and the margin portion 38 having a clearance angle of zero adjacent to the main cutting edge 40a in the opposite direction to the rotation direction A is provided. Width dimension W
Is formed in the range of 0.05 to 0.20 mm, and the clearance angle γ of the clearance surface 46 following the margin portion 38 is formed.
Is formed in the range of 20 to 30 °.

The minor cutting edge 40 in the back taper portion 44
b, rake angle β, width W of margin 38, flank 4
The clearance angle γ of 6 is formed substantially in the same manner as the biting portion 42 for convenience of processing, but the sub cutting edge 40b hardly participates in cutting, and the back taper portion 44 functions exclusively as a guide surface. Therefore, another numerical range may be used.

Here, the reamer 10 is usually made of high-speed steel, but preferably, titanium (Ti), aluminum (Al), A hard coating comprising carbon (C) and at least one of nitrogen (N), such as TiC, T
iN, TiAlN, etc. are provided in a thickness of 1 to 5 μm. The surface of the reamer 10 or its cutting edge 32 or biting portion 42 is made of a cemented carbide or a diamond ultra-high pressure sintered body. At least in these cases,
The outer peripheral cutting edge 40 or the main cutting edge 40a is made of any one of a high-speed steel, a cemented carbide, and a diamond ultra-high pressure sintered body.

The shank portion 30 of the reamer 10 has a depth similar to that of the torsion groove 34 formed in the cutting edge portion 32 and has a linear shape communicating with the shank portion 30 side of each torsion groove 34. Air groove 50 is formed.

When mounted on a stationary rotary drive using compressed air as a power source, the reamer 10 for finishing a diameter of 6.35 mm has a tip diameter of the biting portion 42 of 5.3 m.
m, the maximum diameter D of the biting portion 42 is 6.37 mm, the ratio of the back taper of the back taper portion 44 is in the range of 0.15 to 0.25 mm / 100 mm, and the width of the margin portion 38 is set. Dimension W is 0.10 to 0.20m
m, and the clearance angle γ of the flank surface 46 of the biting portion 42 is formed at 25 to 30 °. Further, when the reamer 10 is mounted on a hand-held rotary drive device using compressed air as a power source, the reamer 10 for finishing the diameter of 10.11 mm has a tip diameter of the biting portion 42 of 9.07 mm and a biting portion 42 Is formed to 10.13 mm, and the ratio of the back taper of the back taper portion 44 is 0.05 to 0.15 m.
m / 100 mm, the width W of the margin 38 is in the range of 0.05 to 0.15 mm, and the clearance angle γ of the flank 46 of the biting portion 42 is 20 to 25 °. You. According to experiments performed by the present inventors, using the two types of reamers, the former and the latter, 3,250 min ^-1 (cutting speed: 650 m / min) and the feed amount 0.07 mm / r
ev (227.5 mm / min), and 1,850 to
2,050 min ^-1 (Cutting speed: 590 to 650 m / m
in) and the feed amount is 0.07 mm / rev (129.5 to
Under the cutting conditions of 143.5 mm / min), when the inner peripheral surface of the prepared hole 16 or 18 of the composite material 12 or 14 shown in FIG. 3 or FIG. 4 is finished, respectively, the depth of the affected layer is 10 μm or less. , Hole accuracy 0 to + 0.076mm
In addition, the required accuracy of the finished surface roughness of 12.5Z or less was satisfied, and a longer life than the conventional reamer 60 was obtained. At the same time, CFR is placed on the exit side of pilot hole 16 or 18.
No fluffing occurred even when P22 was positioned.

As described above, according to the reamer 10 of this embodiment, the extremely large back taper portion 44 whose outer diameter decreases at a rate of 0.05 to 0.25 mm / 100 mm follows the biting portion 42. An extremely small margin portion 38 having a width W of 0.05 to 0.20 mm is formed adjacent to the biting portion 42 in a direction opposite to the rotation direction A of the main cutting edge 40a. Then 2
Since the flank 46 having a large angle of 0 to 30 ° is provided, the cutting resistance of the reamer 10 for processing a composite material is suitably reduced. Further, as a result of the provision of the flank 46 having a large angle of 20 to 30 °, the main cutting edge 40 a
Since a space is formed in which chips generated from the chip are sufficiently accommodated, the finished surface is not roughened due to sliding between the chips and the inner peripheral wall due to the chips being involved. In addition, since the outer peripheral cutting edge 40 is provided so as to be twisted in a direction opposite to a preset rotation direction toward the distal end portion, chips generated from the biting portion 42 are discharged forward, that is, toward the distal end of the reamer. .

Therefore, according to the embodiment, the back taper portion 44 whose diameter decreases at an extremely large rate and the width W
Is provided with a very small margin portion 38 and a flank surface 46 having a large angle γ following the margin portion 38. As a result, the sliding friction under high contact pressure is reduced, and the cutting resistance of the composite material processing reamer 10 is reduced. Suitably reduced, and
As a result of the provision of the flank 46 having a large angle of 20 to 30 °, a space is formed in which the chips generated from the main cutting edge 40a are sufficiently accommodated, and the entrapment of the chips is suppressed. The hole accuracy and the accuracy of the inner peripheral finished surface are increased. Further, since the main cutting edge 40a is provided so that the main cutting edge 40a is twisted in the direction opposite to the preset rotation direction A toward the front end portion, chips generated from the biting portion 42 are discharged forward, that is, toward the front end of the reamer. As a result, the inner peripheral surface of the liquid shim 24 is not shaved by the chips during the transportation of the chips generated from the main cutting edge 40a, and the inner peripheral diameter of the liquid shim 24 is prevented from being enlarged. Is done. Furthermore, the cutting of β titanium which is a difficult-to-cut material, and the carbon content high C content
Also in the cutting of the FRP, as described above, the sliding friction under the high contact pressure is reduced, so that the main cutting edge 40a is hardly worn and the life of the reamer 10 is prolonged. The fluffing of fibers is also preferably eliminated.

Here, when the reduction ratio of the diameter of the back taper portion 44 is less than 0.05 mm / 100 mm, the inner peripheral surface of the finishing hole and the back surface are closed due to springback of a difficult-to-cut material such as β-titanium 20. Since the tapered portion 44 is in sliding contact with a high contact pressure, it is difficult to reduce the cutting resistance. The ratio of the diameter of the back taper portion 44 is 0.2
If it exceeds 5 mm / 100 mm, the gap with the guide bush used in the reaming process becomes large, and the finished hole accuracy decreases.

When the width W of the margin portion 38 exceeds 0.20 mm, the β-titanium 20 is formed similarly to the case where the ratio of the diameter of the back taper portion 44 is less than 0.05 mm / 100 mm. Since the inner peripheral surface of the finishing hole and the margin portion 38 are in sliding contact with a high contact pressure due to the springback of a difficult-to-cut material, it is difficult to reduce the cutting resistance. The width W of the margin portion 38 is 0.05
When it is less than mm, the strength of the main cutting edge 40a of the reamer 10 is insufficient, and the hole size is enlarged due to the bending of the main cutting edge 40a, and the dimensional accuracy is reduced.

Further, when the clearance angle γ of the clearance surface 46 following the margin portion 38 is less than 20 °, the main cutting edge 40 a
Since there is not enough space for accommodating chips generated from the chip, the chips are in sliding contact with the inner peripheral surface of the hole and the finished surface becomes rough, and conversely, the clearance angle γ of the flank 46 following the margin 38 is reduced to 30 °. If it exceeds, the main cutting edge 40a of the reamer 10
Is insufficient, the size of the hole is enlarged due to the bending of the main cutting edge 40a, and the dimensional accuracy is reduced.

FIG. 5 shows a conventional reamer 6 previously devised.
Indicates 0. The reamer 60 has a torsion groove 62 that is twisted in a direction opposite to the rotation direction A toward the tip, and between the inner wall surface, that is, the rake surface 64 and the outer peripheral surface or the land facing the rotation direction A of the torsion groove 62. Outer cutting edge 66
Are formed. A biting portion 70 having a predetermined inclination angle with respect to the center line is formed at the tip of the cutting portion 68 where the outer peripheral cutting edge 66 is formed, and the diameter of the guide portion 72 adjacent thereto is uniform. It has become. In addition, the width dimension W of the margin portion adjacent to the outer peripheral cutting edge 66 of the biting portion 70 is described.
Is relatively large like a normal cutting tool, and the clearance angle γ of the flank following the margin portion is relatively small like a normal cutting tool. Therefore, the above-mentioned conventional reamer 60 is used to prepare the prepared hole 16 or 1 shown in FIG.
When the inner peripheral surface of No. 8 is finished, it is slid by the high surface pressure due to the spring back of β titanium 20, and the cutting resistance becomes extremely large. Therefore, the finished hole is formed by sliding friction under high contact pressure and entrapment of chips. The accuracy and the accuracy of the inner peripheral finished surface are reduced, and the damaged layer generated by frictional heat is disadvantageously thick. Further, since the outer peripheral cutting edge 66 is easily worn by the cutting of the β titanium 20 which is a difficult-to-cut material and the cutting of the CFRP 22 having a high carbon fiber content, the life of the reamer is shortened and the CFR is shortened.
There was also a disadvantage that carbon fibers fluffed at the exit of the hole on the P side.

The shank 30 of the reamer 10 of this embodiment has the same depth as the torsion groove 34 formed in the cutting edge 32 and communicates with the torsion groove 30 side of each torsion groove 34. When compressed air or coolant is supplied from the chuck device in a state where the chuck device is mounted on a rotary driving device (not shown), the linear air groove 50 is formed through the air groove 50. Since the compressed air or the coolant liquid is supplied into the torsion groove 34, the chips generated from the main cutting edge 40a are blown forward of the reamer 10 to further suppress the roughness of the inner peripheral surface due to the chips. And the main cutting edge 40
Since cooling of a is performed, there is an advantage that the durability life is extended.

Here, the composite materials 12 and 14 described above are used.
For example, a heat-resistant alloy sheet such as Inconel may be used in place of β titanium 20, or a plastic sheet reinforced with fibers such as Kepler may be used in place of CFRP22. In addition, the composite materials 12 and 14
May be one in which aluminum lithium alloy sheets and amilad fiber layers are alternately laminated.

The twist angle θ of the twist groove 34 is 3 to 1
5 °, the axial length L of the biting portion 42 is in the range of 2.5 to 3.5 mm, and the inclination angle α of the biting portion 42 is in the range of 8 to 12 °. , The outer diameter D of the reamer 10 (the maximum diameter of the biting portion 42) is 3.175 to 15.87.
5 mm, the main constituent requirement of the present invention, that is, the outer diameter is 0.05 to 0.25 mm / 10
A back taper portion 44 decreasing at a rate within a range of 0 mm is formed following the biting portion 42, and the width dimension W of the biting portion 42 is 0.1 mm adjacent to the main cutting edge 40 a in the direction opposite to the rotation direction A. A margin portion 38 in the range of 0.05 to 0.20 mm is formed, and the margin portion 38 is followed by 20 to 30 °.
When the configuration in which the flank surface 46 having the clearance angle γ within the range of is provided is applied, the above-described operation and effect can be particularly suitably obtained.

The above is merely an example of the present invention, and the present invention can be variously modified without departing from the gist thereof.

[Brief description of the drawings]

FIG. 1 is a side view showing a reamer according to an embodiment of the present invention, in which one side of a center line is cut away.

FIG. 2 is a view showing a distal end surface of the embodiment of FIG. 1;

FIG. 3 is a sectional view of an essential part for explaining a configuration of an example of a composite material in which an inner peripheral surface of a prepared hole is finished by the reamer of the embodiment of FIG. 1;

FIG. 4 is a cross-sectional view of a principal part illustrating a configuration of another example of the composite material in which the inner peripheral surface of the prepared hole is finished by the reamer of the embodiment in FIG. 1;

FIG. 5 is a diagram illustrating a configuration of a conventional reamer.

[Explanation of symbols]

 10: Reamer 12, 14: Composite material 16, 18: Prepared hole 30: Shank portion 32: Cutting edge portion 34: Twisted groove 38: Margin portion 40a: Main cutting edge (outer peripheral cutting edge) 42: Biting portion 44: Back Taper 46: Flank

Claims (2)

(57) [Claims] An inner peripheral surface of a pilot hole formed in a composite material including a shank portion and a columnar cutting edge portion, and a plurality of types of materials including difficult-to-cut materials are laminated, is cut by the cutting edge portion. In the composite material processing reamer to be processed, a torsion groove which is twisted in a direction opposite to a preset rotation direction toward the front end portion is formed in the cutting edge portion, and a torsion groove is formed between the inner wall surface and the outer peripheral surface opposed to the rotation direction. An outer peripheral cutting edge is provided, a biting portion whose outer diameter increases from the tip of the cutting edge portion toward the shank portion, and the outer diameter increases from 0.05 to 1.5 as the direction proceeds toward the shank portion following the biting portion. 0.
A back taper portion decreasing at a rate of 25 mm / 100 mm is formed on the cutting edge portion, and a margin portion having a width dimension of 0.05 to 0.20 mm is adjacent to the outer peripheral cutting edge of the biting portion in the opposite direction. Is formed, and 20 to 20
A reamer for processing a composite material, wherein a flank of 30 ° is provided. 2. The twist angle θ of the twist groove is 3 to 15 °.
And the axial length of the biting portion is 2.5 to 3.5 m.
m, and the inclination angle of the biting portion with respect to the rotation center axis is 8
And the outer diameter of the reamer is 3.175 to 1 °.
The reamer for processing a composite material according to claim 1, which is 5.875 mm.