KR20210076527A - Drill - Google Patents

Abstract

The present invention relates to a drill with improved drilling efficiency and durability. The drill with improved drilling efficiency and durability in accordance with embodiments of the present invention comprises: a shank unit mounted in a holder of a drilling apparatus; and a drill body unit (200) integrally extended from one end of the shank unit. A chip discharge recess is spirally formed on the outer circumference surface of the drill body unit and a cutting blade extended from a drill point (P) is formed at a front end portion of the drill body unit. A cutting surface of the cutting blade includes: a front end cutting surface slantly extended from the drill point (P); a middle cutting surface extended from the front end cutting surface and slanted at an angle less than the front end cutting surface; and a rear end cutting surface extended from the middle cutting surface and slanted at an angle greater than the front end cutting surface.

Description

Drills with improved drilling efficiency and durability{Drill}

The present invention relates to a drill, and more particularly, to a drill with improved drilling efficiency and durability.

In general, a drill is used mounted on a drilling device as a cutting tool for forming a hole having a certain diameter in the object to be processed. Such a drill has various shapes and configurations suitable for the size, shape, and depth of the hole and the material of the object to be processed, such as metal, wood, and plastic material.

However, with the existing drill, it is difficult to process CFRP-ALUMINUM (CFRP+AL) at once, and in particular, it is difficult to apply variously to incotyl and stainless composite materials.

Korean Patent Registration No. 10-1983487 (Drill) Korean Patent Laid-Open No. 10-2019-0028456 (Step Drill)

Accordingly, the present invention has been proposed in consideration of the above matters, and the present invention is to provide a drill that can process CFRP-ALUMINUM (CFRP+AL) at once, and can be applied in various ways, especially in incotyl and stainless composite materials. do.

In addition, it is intended to provide a drill that can reduce machining cost, increase machining quantity, and facilitate regrinding.

The drill with improved drilling efficiency and durability according to embodiments of the present invention includes a shank part mounted on a holder of a drilling apparatus and a drill body part 200 integrally extended from one end of the shank part, and the outer peripheral surface of the drill body part A chip discharge groove is formed in a spiral, and a cutting edge extending from the drill point (P) is formed at the tip of the drill body part, and the cutting surface of the cutting edge is a tip cutting edge extending obliquely from the drill point (P) surface, a middle cutting surface extending from the leading cutting surface and inclined at an angle smaller than the leading cutting surface, and a rear cutting surface extending from the middle cutting surface and inclined at an angle greater than the leading cutting surface.

Here, the cutting edge is formed in a pair on the drilling body, and the angle of the inner angle α1 formed by a line cross-extending upward from a pair of upper cutting surfaces formed on the pair of cutting edges is in the range of 125° to 135° .

And the diameter formed by the pair of upper cutting surfaces is in the range of 25% to 30% of the diameter (D1) of the drill body part.

And the cutting edge is formed in a pair on the drilling body, and the angle of the inner angle α2 formed by a line cross-extending upward from a pair of middle cutting surfaces formed on the pair of cutting edges is in the range of 145° to 155° .

Next, an angle α3 formed by a line extending from the rear end cutting surface 236 to the lower end and the outer surface of the drill body is in the range of 40° to 50°.

The cutting edge of the drill according to the present invention is composed of three stages, so that the replacement cycle is long and the lifespan is extended.

That is, the resistance of the drill is reduced, so that the life of the drill can be extended, and the centripetal property is improved, so that the precision of the machining hole is improved.

In addition, since the load applied to the drill is distributed and the load during initial machining is also reduced, the wear of the cutting edge is reduced and the life of the drill is extended.

In addition, it is easy and precise to dig into the object to be processed, and since the centripetal property is improved so that a straight hole can be easily processed, the quality of the inner wall of the hole is improved and the precision is improved.

Through this, CFRP-ALUMINUM (CFRP+AL) can be processed at once, and it can be applied in various ways, especially in incotyl and stainless composite materials.

1 is a plan view of a drill according to a preferred embodiment of the present invention.
Figure 2 is a reference view showing the tip of the drill according to Figure 1;
3 is a side view of the drill according to FIG. 1 ;
FIG. 4 is a reference view showing a point type and a chisel of the drill according to FIG. 1 .
FIG. 5 is a reference view showing an overgash of the drill according to FIG. 1 .
6 is a point gash and detailed dimensional view of the drill according to FIG. 1 .

Before describing the embodiments according to the present invention in detail, the present invention is not limited to the configurations shown in the following detailed description or the accompanying drawings, which can be used or carried out in various ways.

It is also to be understood that the phraseology or terminology used herein is for the purpose of description only and should not be regarded as limiting.

That is, as used herein, the expressions "mounted," "installed," "connected," "connected," "supported," "coupled," etc. It is used as a broad expression including both direct and indirect mounting, installation, connection, connection, support, and coupling. The expressions “connected”, “connected”, “coupled” are not limited to a physical or mechanical connection, connection, or coupling.

And in this specification, terms indicating a direction such as upper, lower, downward, upward, rearward, bottom, front, rear, etc. are used to describe the drawings, but these terms are used in a direction relative to the drawing for convenience (normally viewed). when) is indicated. These directional terms are not to be taken as literally limiting or limiting the invention in any form.

In addition, terms such as "first", "second", "third", etc. used herein are for illustrative purposes only and should not be construed as implying a relative importance.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

It relates to a drill 10 (hereinafter referred to as a "drill") with improved drilling efficiency and durability according to a preferred embodiment of the present invention, preferably a double stack drill, mounted on a holder of a drilling device (not shown) It includes a shank part 100 and a drill body part 200 integrally extended from one end of the shank part 100 .

The diameter of the shank part 100 may be formed to be the same as the diameter D of the drill body part 200, but is not limited thereto. That is, the diameter of the shank part 100 may be formed to be larger or smaller than the diameter D1 of the drill body part 200 .

The drill body part 200 includes a step part (Step length) 220 and a flute part (Flute length) 210 as shown in FIG. 1 . However, the present invention is not limited to such a shape and can be applied to drills of various shapes.

Next, a pair of cutting edges 230 and 240 extending symmetrically to both sides from the drill point P located on the center line C of the drill body 200 are provided at the tip of the drill body 200 . is formed, and a chisel edge 124 passing through the point P of the drill as shown in FIG. 4 is formed between the pair of cutting edges 230 and 240 . In addition, a pair of chip discharge grooves 250 are spirally formed on the outer peripheral surface of the drill body 200 . The pair of chip discharge grooves 250 are formed to extend from a step length 220 to a flute length 210 .

Hereinafter, a cutting surface having a multi-stage structure with different angles provided on the cutting edge of the drill 10 according to a preferred embodiment of the present invention will be described with reference to FIG. 2 .

A cutting edge 230 extending from the drill point P is formed at the tip of the drill body 200 according to a preferred embodiment of the present invention, and the cutting surface of the cutting edge 230 is a tip cutting surface 232, It includes a middle cutting surface 234 and a trailing cutting surface 236 .

The cutting edge 230 of the drill 10 according to the preferred embodiment of the present invention is preferably configured in three stages as described above, which may decrease durability when configured in two stages, and is manufactured when configured in more than three stages As the process becomes complicated, the manufacturing cost increases, and the possibility of damage to the cutting edge 230 increases.

Next, in the leading cutting surface 232 , the middle cutting surface 234 , and the rear cutting surface 236 , the middle cutting surface 234 is inclined at a smaller angle than the leading cutting surface 232 , and the rear cutting surface 236 is It is inclined at an angle greater than the upper cutting surface 232 .

When the front cutting surface 232, the middle cutting surface 234, and the rear cutting surface 236 are made at such an angle, the load reduction and load distribution of the cutting edges 230 and 240 during the initial machining of the drill 10 are performed. There is an advantage that can extend the life of the drill 10 by reducing wear.

In more detail, the angle formed by the front cutting surface 232 , the middle cutting surface 234 , and the rear cutting surface 236 will be described from the pair of upper cutting surfaces 232 formed on the pair of cutting edges 230 . It is preferable that the angle of the interior angle α1 formed by the lines cross-extending upward, respectively, is formed in the range of 125° to 135°.

This is because when the angle of the inner angle (α1) is formed to be less than 125°, the angle of the drill point increases, so there is a possibility that the wear of the drill point rapidly progresses and the durability is lowered. Since the angle of the drill point is lowered, there is a problem in that it is difficult to center the drilling operation.

That is, there is a problem in that the centripetal property is lowered and the precision of the machining hole is lowered.

Next, it is preferable that the angle of the inner angle α2 formed by the lines cross-extending upward from the pair of middle cutting surfaces 234 formed on the pair of cutting edges 230 is in the range of 145° to 155°.

This has a problem in that the drilling efficiency is lowered when the angle of the inner angle (α2) is formed to be less than 145 °, and durability is lowered when it is formed to exceed 155 °.

That is, since the chip is discharged for a long time, the discharge property of the chip is reduced, and the resistance applied to the drill is increased, so that there is a problem that the life of the drill is reduced.

Therefore, in the drill 10 according to the preferred embodiment of the present invention, the upper cutting surface 232 and the middle cutting surface 234 are formed at such an angle, so that the replacement cycle of the drill 10 is lengthened and the lifespan is extended. have.

Next, the angle α3 formed by the line extending from the rear end cutting surface 236 to the lower end and the outer surface of the drill body 200 is preferably in the range of 40° to 50°.

Next, the diameter D3 formed by the pair of upper cutting surfaces 232 is preferably in the range of 25% to 30% of the diameter D1 of the drill body 200 .

Next, the drill 10 and the upper cutting surface 232 according to a preferred embodiment of the present invention are Comparative Example 1 in which the internal angle α1 is less than 125° and Comparative Example 2 in which the interior angle α1 is greater than 135°, Intermittent cutting This is an evaluation table for testing the performance of Comparative Example 3 and Comparative Example 4 in which the surface 234 interior angle α2 is less than 145° and 155°.

division RPM working length Example 16,000 10M Comparative Example 1 13,000 6M Comparative Example 2 13,500 8M Comparative Example 3 11,500 6M Comparative Example 4 12,500 5M

That is, the drill 10 according to the preferred embodiment of the present invention was damaged at 16,000 RPM and a working length of 10M, whereas in the comparative examples, damage occurred at 13,000 RPM and a working length of 8M.

Therefore, the present invention has the effect of greatly improving the working efficiency and durability of the drill 10 through the above configuration.

Next, FIG. 3 is a side view of the drill according to FIG. 1 , FIG. 4 is a reference view showing a point type and a chisel of the drill according to FIG. 1 , and FIG. 5 is the drill according to FIG. 1 . It is a reference diagram showing overgash. And Figure 6 is a point gash (Point Gash) and detailed dimensions of the drill according to Figure 1 .

Drill 10 according to a preferred embodiment of the present invention has a rake angle (Rake Angle) 520 in the range of 3 ° to 5 °.

And a radial gash angle (Radial Gash Angle) 510 has a range of 20 ° to 30 °.

As shown in FIG. 3 , the reference numeral 310 is symmetrical and connected to the point P. Reference numeral (α) maintains a margin of 1 to 10% as a means for reducing the cutting force.

Referring to FIG. 4 , reference numeral B maintains an angle of 55° to 65° with respect to reference numeral 310 and is connected to a chisel 412 point P. And in order to impart cutting ability, the angle of the reference numeral 420 is preferably maintained at 5° to 15°, and it is preferable to minimize the cutting wear by removing the sharp edge portion of the reference numeral 460 .

Next, referring to FIG. 5 , reference numeral 430 forms a point (P) chisel shape 510, and reference numeral 400 denotes the center of the product to be processed as the center of the center and the point (P). It serves as a centerpiece.

Referring to FIG. 6 , reference numeral 530 passes through point P and maintains an angle of 35° to 45° during thinning, and reference numeral 310 indicates an angle of 15° to 25°. keep And the reference numeral 510 is made symmetrically about the chisel part 412, the angle is maintained at 60 °, and rotated by R 5% to 10% during thinning to form an R value.

Although preferred embodiments of the present invention have been described above, various changes, modifications and equivalents may be used in the present invention. It is clear that the present invention can be equally applied by appropriately modifying the above embodiments. Accordingly, the above description is not intended to limit the scope of the present invention, which is defined by the limits of the following claims.

10: drill 232: leading cutting surface 234: middle cutting surface 236: trailing cutting surface

Claims (5)

The shank unit 100 is mounted on the holder of the drilling device; and
and a drill body part 200 integrally extended from one end of the shank part 100;
A chip discharge groove 250 is formed in a spiral on the outer peripheral surface of the drill body 200,
A cutting edge 230 extending from the drill point P is formed at the tip of the drill body 200,
The cutting surface of the cutting edge 230 is a tip cutting surface 232 inclinedly extending from the drill point P, extending from the tip cutting surface 232 and inclined at a smaller angle than the tip cutting surface 232 . comprising; a middle cutting surface 234 and a rear cutting surface 236 extending from the middle cutting surface 234 and inclined at an angle greater than the leading cutting surface 232; Drills with improved drilling efficiency and durability. The method of claim 1,
The cutting edge 230 is formed in a pair on the drilling body, and the angle of the inner angle α1 formed by a line cross-extending upward from a pair of upper cutting surfaces 232 formed on the pair of cutting edges 230 , respectively. is in the range of 125° to 135°; Drills with improved drilling efficiency and durability. 3. The method of claim 2,
The diameter (D3) formed by the pair of upper cutting surfaces (232) is in the range of 25% to 30% of the diameter (D1) of the drill body part (200); Drills with improved drilling efficiency and durability. The method of claim 1,
The cutting edge 230 is formed in a pair on the drilling body, and the angle of the inner angle α2 formed by a line cross-extending upward from a pair of middle cutting surfaces 234 formed on the pair of cutting edges 230 , respectively. is in the range of 145° to 155°; Drills with improved drilling efficiency and durability. The method of claim 1,
An angle α3 formed by a line extending from the rear end cutting surface 236 to the lower end and the outer surface of the drill body 200 is in the range of 40° to 50°; Drills with improved drilling efficiency and durability.

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