KR101633227B1

KR101633227B1 - Drill tool for processing composite material

Info

Publication number: KR101633227B1
Application number: KR1020150113623A
Authority: KR
Inventors: 조우진
Original assignee: 조우진
Priority date: 2015-08-12
Filing date: 2015-08-12
Publication date: 2016-06-23

Abstract

The present invention relates to a drill tool for forming a hole in a work material made of a composite material in which different kinds of materials are laminated. More particularly, the present invention relates to a drill tool for machining a hole in contact with a composite material, Wherein the cutter and the adapter are made of dissimilar metals. The invention relates to a drill tool for processing a composite material.
As described above, the drill tool for working a composite material according to the present invention does not cause a peeling phenomenon when a hole is formed in a composite material by applying a double point angle, the tip is made of a cemented carbide, and the adapter is made of a heat treatment material. And the friction between the workpiece and the workpiece is minimized by the multi-facetting, so that cutting is easy, and the edge of the oil hole is formed in contact with the cutting edge to provide excellent lubricity and coolability by the cutting oil.

Description

Technical Field [0001] The present invention relates to a drill tool for processing composite materials,

The present invention relates to a drill tool for forming a hole in a work material made of a composite material in which different kinds of materials are laminated, and more particularly, to a drill tool for processing a composite material used in an aircraft such as a composite layer of metal (Al, Ti) and CFRP The present invention relates to a drill tool for processing a composite material comprising a cemented carbide cutter and a heat-treated adapter.

Recently, aircraft structures that have been made of Al materials have been widely changed to composite (CFRP) sheaths and metal (Al, Ti) stiffeners for lighter weight. The characteristics of CFRP materials, In order to reduce the resistance, there is a tendency to be changed to a combination of a plate head bolt and a nut.

Fig. 1 is an outline view showing the condition of a machining hole of a composite material, and Fig. 2 is a photograph showing a phenomenon occurring at the time of machining a single material machining drill.

Most assembly of aircraft structure is more than 60% of drilling process.

It is difficult to realize the added value due to the increase of the process time and the increase of the tool cost.

When the hole tolerance is also set to Tight (Max .03mm) and CFRP material is composed of metal material and multi stacking as difficult material, it is difficult to drill to the desired dimension at once, so that at least 2 ~ 5 times of hole size are achieved.

The increase in the number of cutters required in this process makes it difficult to realize the added value due to an increase in the processing time and an increase in the tool cost.

Cutter Geomety developed for conventional single material processing is compatible with aircraft material composed of multi stack and unstable dimensional stability and it is difficult to process in full size at once. It is difficult to process CFRP part, Ti part deterioration, Al Part Melt phenomenon, There is a problem that a cutter is damaged or a part is deformed due to a severe processing resistance.

In order to solve such a problem, prior art related to a drill for processing a composite material is a drill for a composite material which is made by cutting a material to be processed including at least a part of a fiber reinforced composite material in the publication No. 2012-0089685, A tapered portion formed in a tapered shape by a difference in diameter between a tip end portion formed and a rear end side of the tip end portion and having a distal end outer diameter and a rear end outer diameter larger than the distal end outer diameter; And a straight portion formed to have a diameter equal to or larger than the outer diameter of the rear end of the taper portion so as to be able to form a finishing diameter larger than the outer diameter of the rear end portion of the taper portion, wherein an outer peripheral cutting edge twisted in a helical shape is formed on the outer circumference of the taper portion, And the diameter of the perforations is set to be larger. Drills for composite materials are disclosed.

Another conventional drill body includes a drill body and a shank formed at one end of the drill body. The drill body includes a rib formed in a spiral shape along the axial direction of the drill body, And a drill head formed at the other end of the drill main body in which the shank is not formed, wherein the drill head is formed in a multi-stage so that a first cutting edge and a second cutting edge, And the second cutting edge is formed in a direction toward the drill head, the point angle of the first cutting edge is 90to 130 degrees, and the angle of incision of the second cutting edge is 5 to 15 degrees And the twist angle formed by the chip discharge groove with the rotation axis of the drill main body is 20 to 40 degrees.

However, the drill tool for processing a composite material used in the prior art is mainly made of a single material having the same portion to be punched in the material and the portion to be bonded to the air tool, and the portion to be punched and the portion to be bonded to the air tool However, it is disadvantageous in that drills are manufactured in conformity with the hole drilling portion made of mostly expensive materials, and thus the manufacturing cost is very high. In addition, there is a disadvantage in that the drill is very vulnerable to the thrust resistance due to the straight line.

The drill tool for working a composite material according to the present invention has been developed in order to solve the above-mentioned problems, and it has been found out that a cutter is broken or a part is deformed due to a CFRP part peeling phenomenon, a Ti part deterioration phenomenon, an Al part melting phenomenon, And to provide a drill tool for processing a composite material.

The present invention provides a drill tool for forming a hole in a work material made of a composite material having different kinds of materials stacked thereon. The drill tool has a cutter for positioning the tip of the cutter in contact with the composite material to form a hole, And the cutter and the adapter are made of dissimilar metals.

As described above, the drill tool for working a composite material according to the present invention does not cause a peeling phenomenon when a hole is formed in a composite material by applying a double point angle, the tip is made of a cemented carbide, and the adapter is made of a heat treatment material. And the friction between the workpiece and the workpiece is minimized by the multi-facetting, so that cutting is easy, and the edge of the oil hole is formed in contact with the cutting edge to provide excellent lubricity and coolability by the cutting oil.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram showing conditions of a processing hole of a composite material. Fig.
Fig. 2 is a photograph showing a phenomenon occurring in machining a single material processing drill. Fig.
3 is an outline view showing a cutter shape of a drill required for each material.
4 is an outline photograph of a drill tool for processing a composite material according to the present invention.
5 is a photograph showing an oil hole of a conventional drill tool.
6 is a photograph showing an oil hole of a drill tool for working a composite material according to the present invention.
7 is a partial enlarged schematic view for explaining a forming portion of an oil hole of a drill tool for working a composite material of the present invention.
8 is a schematic view of a drill tool for processing a composite material according to the present invention, to which a double point angle is applied.
9 is a photograph showing the tip shape of a conventional drill tool.
10 is a photograph showing a facet of a drill tool for processing a composite material according to the present invention.
11 is an enlarged view showing a chisel edge of a drill tool for processing a composite material according to the present invention.
12 is an enlarged photograph showing a streamlined tip end point of a drill tool for processing a composite material according to the present invention.

A drill tool 100 for forming a hole in a work material made of a composite material having different kinds of materials according to the present invention comprises a cutter 110 for positioning a hole in a composite material and positioned at a tip end of the cutter 110, The cutter 110 and the adapter 120 are made of dissimilar metals. The cutter 110 and the adapter 120 are connected to an air tool for driving the cutter 110.

The cutter 110 is composed of a chisel edge 115 which is a vertex which is positioned at a tip and directly contacts a work material to make a hole and a plurality of facets 111 which are inclined rearward with respect to the chisel edge 115 The facet 111 has a first cutting surface 111a formed as a mildly inclined surface rearward of the chisel edge 115 and a second cutting surface 111b extending from the rear end of the first cutting surface 111a, 111b.

The two facets 111 symmetrical with respect to the chisel edge 115 of the facets 111 are formed with oil holes 112 through which the cutting oil flows in the longitudinal direction of the drill tool 100, And the edge of the oil hole 112 is formed in contact with the cutting edge 114 of the facet 111.

Further, the cutter 111 and the adapter 120 are bonded by blazing.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a drill tool for working a composite material according to the present invention will be described in detail with reference to the accompanying drawings.

3 is a schematic view showing a cutter shape of a drill required for each material.

In the case of airplanes, the types of material used for each aircraft part and the method of lamination were different, and standardized cutters could not meet the characteristics of each material.

Particularly, CFRP requires high RPM, high speed FEED and minimum cooling. Among Al, RPM, medium speed FEED and intermediate cooling are required. Ti requires low RPM, low speed FEED and maximum cooling.

The optimal cutter shape required for each material is different.

For CFRP, the angle of cutter tip point is small (90 ~ 120 °)

Al - Cutter The angle of the tip point is intermediate (120 ~ 135 °)

Ti - Cutter Tip angle is large (135 ~ 150 °)

4 is an outline photograph of a drill tool for processing a composite material according to the present invention.

As shown in FIG. 4, the present invention relates to a drill tool 100 for use in manufacturing an aircraft, which is made of a composite material. The drill tool 100 of the present invention includes a cutter And an adapter 120 which is positioned at a rear end of the cutter 110 and is fastened to an air tool for driving the cutter 110.

The adapter 120 is formed of a body 121 that contacts the rear end of the cutter 110 and a threaded surface 122 that is screwed with the air tool on the outer circumference of the rear end of the body 121.

Particularly, the cutter 110 and the adapter 120 are made of dissimilar metals.

In detail, the cutter 110 is made of a cemented carbide to fit the CFRP material used in aircraft.

However, since the cemented carbide is expensive, the adapter (120) to be coupled with the air tool is characterized in that the SMC 4 series, which is relatively low in price and hardness, is heat-treated as compared with the cemented carbide.

SMC refers to chromium molybdenum steel, and the SMC four series contains 0.38-0.43 wt% carbon.

The heat treatments of four kinds of SMCs were hardened by high frequency heat treatment.

The cutter 111 and the adapter 120 are bonded by blazing.

Blazing is a method of melting a metal (flux) having a melting point lower than that of the base material without melting the base material and bonding the joints with the suction force by surface tension.

That is, the cutter 110 and the adapter 120 are bonded to each other by adding silver powder to the joint surface 130 of the cutter 110 and the adapter 120 to apply heat to the cutter 110, A protrusion is formed on one of the joint surfaces 130 of the adapter 120 and a groove is formed on the other joint surface 130 corresponding to the protrusion.

On the other hand, before bonding, grease is applied to the bonding surface 130.

Particularly, in the present invention, a sharp V-shaped protrusion is formed at the rear end of the cutter 110, and a V-groove is formed at the front end of the adapter 120 so as to firmly bond them together.

Silver-copper-zinc alloy is also included in silver-copper alloy. It is good in fluidity, can make solderless parts without groove, has excellent strength and ductility of soldered area, , But there is a very low characteristic of the freezing point.

The adapter 120 has a cylindrical body 121 directly contacting the rear end of the cutter 110 and a threaded surface 122 at the outer circumferential edge of the rear end of the body 121. The threaded surface 122 To the air tool.

FIG. 5 is a photograph showing the oil hole of the conventional drill tool, FIG. 6 is a photograph showing the oil hole of the drill tool for working the composite material of the present invention, and FIG. This is a partial enlarged schematic view.

5 to 6, the two holes 111 symmetrical with respect to the chisel edge 115 are formed in the drill tool 100 so that the oil holes 112 through which the cutting oil flows respectively are connected to the drill tool 100 Are formed in the longitudinal direction.

5, the conventional oil hole 112 is formed at a relatively far position from the cutting edge 114. However, in order to maximize the cooling property and the lubricity of the cutting edge 114, The edge of the oil hole 112 is formed so as to abut the cutting edge 114 formed by the plurality of facets 111 as shown in Fig.

A facet refers to a cut surface such as a jewel. In the present invention, the cut surface formed on the drill tool 100 is referred to.

On the other hand, in theory, the oil hole 112 is most efficiently contacted with the cutting edge 114, but the oil hole 112 is in contact with the cutting edge 114 and is damaged when the cutting edge 114 is machined for reuse Therefore, it is preferable to be formed substantially within a half of the primary relief width.

FIG. 8 is a photograph showing a tip shape of a conventional drill tool, FIG. 9 is a photograph showing a facet of a drill tool for processing a composite material of the present invention, and FIG. 10 is a schematic view of a double point angle of a drill tool for processing a composite material of the present invention.

The cutter 110 is formed such that a plurality of facets 111 are inclined rearward with respect to a chisel edge 115 positioned at the forefront so as to directly contact the cutter 110 and make holes in the material.

8, a cutting path 113, which is a discharge passage for cutting and chipping the chip on the inner circumferential surface, is formed in a spiral-shaped boss at the rear end of the facet 111. The plurality of facets 111 are cut The rear clearance surface of the edge 114 is subjected to a large angle machining so as to minimize friction with the workpiece and to improve chip discharge.

That is, the cutter 110 has a plurality of facets 111 inclined in the circumferential direction around the chisel edge 115, which is the vertex of the cutter 110, The first cutting surface 111 is formed of a first cutting surface 111a formed as a mildly inclined surface behind the chisel edge 115 and a second cutting surface 111b formed as a sharpened surface extending to the rear end of the first cutting surface 111a .

As shown in FIG. 10, in order to process a metal having high toughness so as to be suitable for a double material structure of a composite material and a metal, a tool angle must be large. In order to prevent peeling of the composite material, Angle was applied.

If Al and carbon fiber reinforced plastic (CFRP) are stacked, the first cutting surface is formed to be 120 to 135 degrees so as to be suitable for cutting the AL layer in the lower layer, and the second cutting surface is formed to be 30 to 90 degrees When the edge of the drill penetrates the CFRP of the upper layer, the bottom surface is not peeled off.

In addition, when Ti and carbon fiber reinforced plastic (CFRP) are laminated, the first cutting surface is formed at 135 to 150 degrees to be suitable for infiltration of Ti in the lower layer, and the second cutting surface is formed at 30 to 90 degrees, When the edge of the CFRP passes through the CFRP of the upper layer, the bottom surface is not peeled off.

11 is an enlarged view showing a chisel edge of a drill tool for working a composite material according to the present invention.

As shown in FIG. 11, the width of the chisel edge 115 is set to be within 0.03 mm in order to facilitate positioning when the cutter 110 is initially inserted, and to minimize the thrust resistance.

If the width of the chisel edge 115 exceeds 0.03 mm, the sharp edge is too hard to be positioned.

12 is an enlarged photograph showing the streamlined tip end point of the drill tool for working the composite material of the present invention.

Generally, the tip of the cutter 110 is formed in a straight line. However, a tip of a drill tool for a composite material of the present invention adopts a streamlined tip end point as shown in FIG.

That is, the shape of the tip of the cutter 110 is formed to be 'S' so that the portion contacting the workpiece is formed into a convex curve, thereby reducing the rotation resistance of the cutter 110, increasing the wear resistance and improving the chip breaking ability.

100. Drill tool
110. Cutter 111. Facet 111a. The first cutting surface
111b. Second cutting face 112. oil hole 113. cutting groove
114. Cutting edge 115. Chisel edge
120. adapter 121. body 122. threaded surface
130. Joint surface

Claims

The drill tool 100 includes a cutter 110 positioned at a tip end of the cutter 110 and contacting the composite material to form a hole, an adapter 120 disposed at a rear end of the cutter 110 and coupled to an air tool for driving the cutter 110, Wherein the cutter (110) and the adapter (120) are made of dissimilar metals to form holes in a work material made of a composite material in which different kinds of materials are stacked,
The cutter 110 is composed of a chisel edge 115 which is a vertex which is positioned at a tip and directly contacts a work material to make a hole and a plurality of facets 111 which are inclined rearward with respect to the chisel edge 115 The facet 111 has a first cutting surface 111a formed as a mildly inclined surface behind the chisel edge 115 and a second cutting surface 111b extending from the rear end of the first cutting surface 111a and formed as a steeply inclined surface ),
When the workpiece is made of Al and carbon fiber reinforced plastic (CFRP), the first cutting surface is formed to be 120 to 135 ° so as to fit the AL layer of the lower layer, and the second cutting surface is formed to be 30 to 90 ° In addition,
When the workpiece is made of Ti and carbon fiber reinforced plastic (CFRP), the first cutting surface is formed to be 135 to 150 degrees so as to be suitable for infiltrating Ti in the lower layer, and the second cutting surface is formed to be 30 to 90 degrees So that when the edge of the drill penetrates the CFRP of the upper layer,
A protrusion is formed on a joint surface 130 of one of the cutter 110 and the adapter 120 and a groove is formed on the other joint surface 130 corresponding to the protrusion, (120) are bonded together by blading,
When the cutter 110 is initially inserted, the chisel edge 115 is formed to have a width of 0.03 mm or less in order to facilitate positioning and reduce the thrust resistance,
An oil hole 112 in which the cutting oil flows is formed in the longitudinal direction of the drill tool 100 in two facets 111 symmetrical with respect to the chisel edge 115 of the plurality of facets 111, Characterized in that the edge of the oil hole (112) is formed to abut the cutting edge (114) of the facet (111).

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