JP2602032Y2 - Double angle drill - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double angle drill, and more particularly to a double angle drill suitable for simultaneously drilling a fiber reinforced resin composite and an aluminum alloy plate.

[0002]

2. Description of the Related Art Composite materials such as CFRP (carbon fiber reinforced plastic) obtained by impregnating and hardening a resin into laminated carbon fibers and the like have high strength and rigidity while being lightweight, and have a structure such as an aircraft. Widely used as a member.

[0003] In the assembly process of an aircraft, a composite material component is often riveted to an aluminum alloy skeleton component or the like. In order to perform rivet joining, it is necessary to drill holes of the same diameter in the composite material part and the skeleton part, but it is desirable to perform this operation at a time with both parts superimposed. As a drill suitable for such an application, for example, Japanese Patent Application Laid-Open No. 63-306812 discloses a double angle drill for drilling a composite material having a primary cutting edge for metal drilling and a flat secondary cutting edge. Are listed. As shown in FIGS. 6 and 7 (enlarged view of a portion A in FIG. 6), the double angle drill disclosed in the publication has a twist angle α of a twist groove 3 formed from a tip portion 1 to a shank portion 20 of 20 °. And the tip angle β of the primary cutting edge 4 is 90 °, and the tip angle γ of the secondary cutting edge 5 is 20 ° to 30 °. According to this double-angle drill, a primary hole with a relatively small diameter is first drilled by the primary cutting edge 4, and then a secondary hole with a target diameter is drilled by the secondary cutting edge 5 cutting the outer periphery of the primary hole. At the time of perforation, transient delamination (delamination) occurs around the primary hole of the composite material, but this delamination is removed during cutting by the secondary cutting edge 5.

On the other hand, in recent years, in order to improve the wear resistance of cutting tools such as drills, Japanese Patent Application Laid-Open No. 2-48106
As described in the official gazette and Japanese Utility Model Publication No. 1-101766,
A technique for coating a cutting edge portion with diamond is generally practiced.

[0005]

By the way, in the above-mentioned double angle drill, delamination of the composite material in a short-time drilling operation is effectively prevented, but has a drawback that its life is short.

That is, in the actual drilling operation, the flank of the cutting edge is severely worn, and when 20 to 30 holes are drilled, the cutting edge is lost and delamination occurs around the hole on the composite material side. When the plate thickness on the aluminum alloy side is large, the metal chip generated on the rake face 6 of the cutting edge does not move smoothly to the twist groove 3 because the twist angle α is large. as a result,
In some cases, chips were clogged on the rake face 6 and protruded in the outer peripheral direction, resulting in excessive cutting of the inner surface of the hole on the composite material side. Therefore, in order to prevent such a situation, the torsion angle α is set to 10
°, the chip discharge performance was improved. Also,
The above-mentioned method of coating the cutting edge with diamond was tried, but depending on the thickness of the coating, the sharpness of the cutting edge was significantly reduced, or the coating was peeled off. .

Therefore, the present invention solves the above-mentioned problems of the prior art, significantly improves abrasion resistance, enhances chip discharge, and enables high-precision drilling over a long period of time. It is an object to provide a double angle drill which is most suitable for simultaneous drilling of aluminum and an aluminum alloy plate.

[0008]

In order to achieve the above object, a double-angle drill according to the present invention has a twist groove for discharging chips from the tip to the vicinity of a shank, and a metal drill having a tip. It is composed of a primary cutting edge having a tip shape of and a flat secondary cutting edge having a tip angle smaller than the primary cutting edge which is continuous with the primary cutting edge, and a carbon fiber reinforced resin composite material is joined to an aluminum alloy plate In a double-angle drill for drilling a laminated plate, the tip angle of the primary cutting edge is about 118 °, and the tip angle of the secondary cutting edge is about 30 °
Setting the ratio between the maximum diameter of the primary cutting edge and the maximum diameter of the secondary cutting edge to 1/3 to 1/2, and setting the torsion angle of the torsion groove in the range of 5 ° to 15 °; From the tip to the portion beyond the secondary cutting edge is coated with diamond, and, while maximizing the thickness of the diamond coating at the tip of the drill, the thickness of the diamond coating of the primary cutting edge is adjusted to the thickness of the secondary cutting edge. The thickness of the diamond coating is set to be greater than the thickness of the diamond coating, and
μm, and the thickness of the diamond coating after the secondary cutting edge portion is set to 10 to 20 μm.

[0009]

According to the double angle drill of the present invention, the primary cutting edge that first contacts the work is the same as the metal drill.
Since it has a tip angle of 18 ° and the diamond coating on the drill tip is thick, it is strong against impact and does not break sharp drill tips or peel off the diamond coating.

Also, since the twist angle of the twist groove is small,
Chips move smoothly from the rake face to the twist groove,
Delamination around the primary hole due to chip clogging is reduced. Reducing the helix angle increases cutting resistance, but wear and damage to the cutting edge are prevented by the diamond coating.

The delamination generated around the primary hole on the composite material side is removed by the secondary cutting blade. However, since the secondary cutting blade is flat and has a diamond coating having an optimum film thickness. In addition, the sharpness of the cutting edge is not lost over a long period of time, and drilling without delamination becomes possible.
There is no peeling of the diamond coating, and the durability is significantly improved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a double angle drill according to the present invention will be described below with reference to the accompanying drawings.

As shown in FIGS. 1 to 3, the double angle drill of the present embodiment has two twist grooves 3 formed on the outer peripheral surface from the tip 1 to the shank 2, and has a twist angle α. Is selected in the range of 5 ° to 15 °. In this embodiment, a twist angle of 10 ° was used. The distal end portion 1 includes a primary cutting edge 4 on the distal end side, and a secondary cutting edge 5 formed continuously with the primary cutting edge 4. The primary cutting edge 4 has a tip angle β of 118 °, like a general metal drill.
Was used. The secondary cutting edge 5 is formed as a flat cutting edge like a known dagger drill, and has a tip angle γ.
Used 30 °. Further, as shown in FIG. 3 (viewed in the direction of arrow C in FIG. 1), the ratio between the maximum diameter d of the primary cutting edge 4 and the maximum diameter D of the secondary cutting edge 5 is 1/2 to 2/3. Is selected in the range of
In this embodiment, 2/3 is used. In the figure, 8 and 9 are flank surfaces of the primary cutting edge 4 and the secondary cutting edge 5, respectively.

As shown in FIGS. 2 to 5, a micro tip made of a mixed gas consisting of 1% methane and 99% hydrogen is provided at the tip 1 from the drill tip 7 to a portion beyond the secondary cutting edge 5 as shown in FIGS. Coating 1 by microwave plasma CVD
0 is given. The film thickness of the diamond coating 10 is about 25 mm at the drill tip 7, 10 to 25 μm at the primary cutting edge 4, and 10 to 2 μm after the secondary cutting edge 5.
It is formed to be 0 μm. In addition, the above-mentioned CV
According to the method D, the diamond coating is formed to a thickness of 0.1 to 10
It can be arbitrarily formed in a range of 0 μm.

Using the double angle drill, the present inventors simultaneously drilled a composite material of a composite material part (CFRP) and an aluminum alloy plate. The drilling conditions at this time are as follows: p. m, feed amount is 0.04mm / re
v, composite material thickness is 6mm, aluminum alloy plate thickness is 3m
m, the drill diameter is 4.8 mm. As a result, the chips are discharged well from the twist groove 3, and even if 150 holes are drilled, there is no breakage of the cutting edge and no peeling of the diamond coating, which is more than 7 times that of the conventional product. The life was able to be obtained.

Various experiments were carried out to produce the double angle drill of the embodiment. Then, for diamond coating, the film thickness of the primary cutting edge 4, particularly the drill tip 7
The thickness of the primary cutting edge 4 was smaller when the thickness of the secondary cutting edge 5 was larger than that of the secondary cutting edge 5. When the thickness of the primary cutting edge 4 was set to 25 μm or more, it was confirmed that no chipping occurred, but the cutting ability was reduced. Further, when the thickness of the primary cutting edge 4 was set to 10 μm or less, chipping occurred at the cutting edge. When the film thickness after the secondary cutting edge 5 was set to 20 μm or more, delamination occurred on the composite material side, and when the film thickness was set to 10 μm or less, peeling of the coating came to occur.

On the other hand, it was found that when the torsion angle α of the torsion portion 3 was set to 5 ° or less, the cutting resistance increased and the cutting edges 4 and 5 were damaged. When the angle was set to 15 ° or more, chips clogged the rake face 6 of the cutting edge, and delamination on the composite material side occurred.

Further, the maximum diameter d of the primary cutting edge 4 and the secondary cutting edge 5
When the ratio d / D with respect to the maximum diameter D was set to 1/2 or less, the amount of cutting by the secondary cutting edge 5 increased, and the wear and damage of the secondary cutting edge 5 increased. On the other hand, if it is set to 2/3 or more, the cutting amount by the secondary cutting edge 5 is too small, so that the transient delamination around the primary hole cannot be cut off by the secondary cutting edge 5.

[0019]

As is clear from the above description, according to the double angle drill of the present invention, the cutting action is achieved by the cooperative action of the shape of the tip and the torsion angle of the torsion groove and the diamond coating having an appropriate thickness. The lack of blades, delamination of the composite material, clogging of chips, etc. are reliably prevented, and the durability of the drill is greatly improved. Can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of a double angle drill according to the present invention.

FIG. 2 is an enlarged view of a portion B in FIG.

FIG. 3 is a view taken in the direction of the arrow C in FIG. 1;

FIG. 4 is a view as seen from an arrow F in FIG. 2;

FIG. 5 is an enlarged sectional view taken along line EE in FIG. 4;

FIG. 6 is a side view showing a conventional double angle drill.

FIG. 7 is an enlarged view of a portion A in FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tip 2 Shank 3 Torsion groove 4 Primary cutting edge 5 Secondary cutting edge 6 Rake face of cutting edge 7 Drill tip 8 Relief surface of primary cutting edge 9 Relief surface of secondary cutting edge 10 Diamond coating α Helix angle β Primary cutting edge Tip angle γ Tip angle of secondary cutting edge d Maximum diameter of primary cutting edge D Maximum diameter of secondary cutting edge

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor, Seimi Takebata 20 Ishigane, Toyama City, Toyama Prefecture Fuji Koshiuchi Co., Ltd. (72) Inventor, Shoichi Kobori 2-4-1 Shiba Park, Minato-ku, Tokyo No. Fujikoshiuchi Co., Ltd. (56) References JP-A-63-306812 (JP, A) JP-A-5-69214 (JP, A) JP-A-3-170216 (JP, A) JP-A-4-210315 (JP) JP, A) JP-A 4-5367 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B23B 51/00

Claims (1)

(57) [Scope of request for utility model registration] A twist groove for discharging chips is formed from the tip to the vicinity of the shank, and the tip has a primary cutting edge having a tip shape of a metal drill, and is connected to the primary cutting edge and is connected to the primary cutting edge. It consists of a flat secondary cutting edge with a small tip angle, and a carbon fiber reinforced resin composite on an aluminum alloy plate
In a double angle drill for drilling a laminated plate joined with materials, the tip angle of the primary cutting edge is about 118 °, the tip angle of the secondary cutting edge is about 30 °, the maximum diameter of the primary cutting edge and the The ratio to the maximum diameter of the secondary cutting edge
1/3 to 1/2, the twist angle of the twist groove is set in the range of 5 ° to 15 °, diamond is coated from the tip of the drill to a portion beyond the secondary cutting edge, and the tip of the drill is While maximizing the film thickness of the diamond coating, the film thickness of the diamond film of the primary cutting edge is reduced.
The thickness of the diamond coating on the secondary cutting edge is made thicker than the thickness of the diamond coating on the primary cutting edge, and
25 μm, and the thickness of the diamond coating after the secondary cutting edge is 10 to 20
A double angle drill characterized by having a diameter of μm.