KR20210026969A - Gun Drill Using Square Insert - Google Patents

Abstract

In the present invention, in the gun drill 200 including the cutting body 210, the cutting body 210 has a V-shaped groove 214 consisting of a bottom surface 214a and a side surface 214b parallel to the drill center axis, It includes at least one guide pad (217a, 217b, 218a, 218b) having a contact surface in contact with the inner surface of the hole processed during drilling, and the foremost end of the bottom surface (214a) for processing the hole during drilling. It relates to a gun drill using a square insert, characterized in that a square-shaped cutting insert 211 may be installed, and any one corner 211a of the square is located at the foremost end of the cutting body 210.

Description

Gun Drill Using Square Insert

The present invention relates to a gun drill, and in particular, to a gun drill that improves the machining speed of a drill and reduces vibration and damage by using a square-shaped insert.

1 is a perspective view of a conventional gun drill 100, FIGS. 2 and 3 are a perspective view of a cutting body 10 of a conventional gun drill, and FIGS. 4 and 5 are plan and front views of a conventional gun drill cutting body 10.

The gun drill 100 is generally composed of a cutting body 10, a tube 20, and a driver 30.

The cutting body 10 is made of tungsten carbide and processes holes formed by drilling. The tube or plot 20 is connected to the cutting body 10 to transmit torque and lateral force, and is manufactured by roller pressing the cross section of a general steel pipe in a V shape.

The processing chips of the material cut by the cutting body 10 are discharged through the V-shaped groove 11.

The driver 30 is a part that is inserted into the power transmission unit, and the hole is machined by the power transmitted to the driver 30.

The cutting body 10 of the conventional gun drill is made of a carbide material with a length of 50-60 mm and a relief 13 having a diameter smaller than that of the V-shaped groove 11, the contour 12 in contact with the machining hole, and the contour 12. ), a cutting portion 14 for processing a hole, and a land portion 16 that prevents the cutting body from twisting into a flat blade portion such as the cutting portion 14.

The contour 12 is in contact with the inner surface of the hole to be machined so that the cutting body 10 is supported in the machined hole, and the relief 13 does not come into contact with the machined hole unlike the contour 12, so that the cutting body 10 is not in contact with the machined hole. Make it possible to rotate.

If there is no relief 13 on the outer circumferential surface of the cutting body 10 and there is only the contour 12, the cutting body 10 will be interlocked with the machining hole, making it impossible to rotate.

Carbide, which is a material of the conventional cutting body with such a structure, has high hardness due to its characteristics, but is weak against impact, so it may be destroyed when vibration occurs or chips are interlocked, so that the touch work is performed at a very slow speed compared to the standard work. do.

In addition, when using the gun drill for a certain period of time, it must be ground again to raise the blade due to wear of the cut.

For this reason, a special type of insert tip was used to improve the working speed of the gun drill and to easily change the cutting edge when abrasion occurs, but such a special type of insert has a problem that the manufacturing cost is high.

In general, inserts (square spmt, spmx) used in insert drills are manufactured by mass production, so they are stabilized in terms of quality and price. (M-grade: tolerance ±0.05mm)

Therefore, if a square insert, which is mass-produced, can be applied to a gun drill, it will be possible to increase the working speed to be touched while reducing the production cost.

Registered utility model: No. 20-0257396-0000 (2001.12.03) Publication Patent: No. 10-2007-0037644 (2007.04.05)

In the present invention, it is intended to be able to apply a square insert to a cutting body of a gun drill.

In addition, in the present invention, it is intended to additionally install an insert in contact with the inner surface of the hole to be machined so that vibration does not occur during the cutting body.

In addition, in the present invention, a guide pad is installed in place of the contour of the cutting body in contact with the hole to be processed in the prior art, and the guide pad is installed on the opposite side of the added insert, so that the added insert and the guide pad are processed together. It is intended to be able to prevent vibration during processing by making local movements from the inside.

In the present invention, in the gun drill 200 including the cutting body 210, the cutting body 210 has a V-shaped groove 214 consisting of a bottom surface 214a and a side surface 214b parallel to the drill center axis, It includes at least one guide pad (217a, 217b, 218a, 218b) having a contact surface in contact with the inner surface of the hole processed during drilling, and the foremost end of the bottom surface (214a) for processing the hole during drilling. It relates to a gun drill using a square insert, characterized in that a square-shaped cutting insert 211 may be installed, and any one corner 211a of the square is located at the foremost end of the cutting body 210.

In addition, in the present invention, the bottom surface 214a includes an outer first edge 214ad parallel to the drill center axis, and the bottom surface 214a has a square shape located at the rear of the cutting insert 211 The guide insert of is installed, and one side of the square shape of the guide insert is parallel to the first edge 214ad and may contact the inner surface of the hole processed during processing.

In addition, in the present invention, a contact surface of at least one guide pad 217a, 217b, 218a, 218b and one side of the guide insert parallel to the first corner may be at positions facing each other with respect to the central axis of the drill.

In addition, in the present invention, there are two guide inserts 212 and 213, and the cutting insert 211 has a first side surface 211b that faces inside the V-shaped groove 214 at any one of the corners 211a. It includes a second side surface 211c facing outward, and the second side surface 211c may form an angle of 30° to 50° with the first edge 214ad.

In addition, in the present invention, the at least one guide pad is four, and two of the four guide pads 217a and 217b and the two guide inserts 212 and 213 are opposite to the central axis of the drill, and the remaining two The guide pads 218a and 218b may be positioned at 90° from the two guide pads 217a and 217 around the central axis of the drill.

In addition, in the present invention, the guide pad includes two protrusions and a fixing part 217ab positioned between the two protrusions, and the guide pad is fixed to the cutting body by the fixing part, and the outer side of the protrusion The surface becomes the contact surface in contact with the surface to be drilled.

In addition, in the present invention, the cutting body is made of carbon steel, and contours and reliefs may be ground.

In the present invention, the square insert is applied to the cutting body of the gun drill to increase the cutting speed and reduce the production cost.

In addition, in the present invention, by additionally installing a square insert in contact with the inner surface of the hole to be processed at the rear of the cutting insert to prevent the cutting body from generating vibration during processing.

In addition, in the present invention, a guide pad is installed in place of the contour of the cutting body in contact with the hole to be processed in the prior art, and the guide pad is installed on the opposite side of the added insert, so that the added insert and the guide pad are processed together. It is possible to prevent vibration during processing by making local bows from the inner surface.

1 is a perspective view of a conventional gun drill.
2 and 3 are perspective views of a cutting body 10 of a conventional gun drill.
4 and 5 are a plan view and a front view of a conventional gun drill drill tip 10.
6 is a perspective view of the gun drill 200 according to the present invention.
7 is a plan view of the gun drill cutting body 210 of the present invention.
8 to 10 are diagrams illustrating a state in which FIG. 7 is sequentially rotated by 90°.
11 is a side view of the gun drill cutting body 210 of the present invention.
12 is a view showing the force applied to the cutting body 210 in the hole to be processed.

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

Figure 6 is a perspective view of the present invention gun drill 200, showing the cutting body 210, the tube 220 and the driver 230.

In the present invention, a square cutting insert 211 is installed at the front end of the gun drill cutting body 210, and square first and second guide inserts 212 and 213 are sequentially installed at the rear of the cutting insert.

FIG. 7 is a plan view of the gun drill cutting body 210 of the present invention, and FIGS. 8 to 10 are views of a state in which FIG. 7 is rotated 90° to 90° sequentially, and FIG. 11 is a side view.

The cutting body 210 has a V-shaped groove 214 formed of a bottom surface 214a and a side surface 214b parallel to an axis (hereinafter, referred to as “drill center axis”) penetrating the drill in the longitudinal direction.

In the present invention, a cutting insert 211 is installed at the foremost end of the V-shaped bottom surface 214a, and first and second guide inserts 212 and 213 are sequentially installed at the rear thereof.

The cutting insert 211 installed at the foremost end has a square shape, and a first corner 211a, which is any one corner of the square, is located at the uppermost end of the cutting body 200 as shown in FIG. 7.

First to third grooves 214aa, 214ab, 214ac into which the cutting insert 211 and the first and second guide inserts 212 and 213 can be mounted are installed on the bottom surface 214a.

The cutting insert 211 installed in the first groove 214aa has a first edge 211a positioned at the most end of the cutting body 200, a first side surface 211b facing inward from the first edge, and outward. It has a second side (211c) facing.

The bottom surface 214a has a first edge 214ad positioned outside and parallel to the central axis of the drill. The cutting insert 211 is installed in the first groove 214aa of the bottom surface 214a so that the second side 211c is in the range of 30° to 50° with the first corner 214ad, It is preferable to machine the hole by.

Since the angle between the first side 211b and the second side 211c is 90°, the first side 211b and the first edge 214ad will be 40° to 60°.

Preferably, the second side 211c has the first edge 214ad, 40°, and the first side 211b and the first edge 214ad 50°.

The first and second guide inserts 212 and 213 mounted in the second and third grooves 214ab and 214ac have one side surface 212a and 213a installed in parallel with the first edge 214ad.

One side surface (212a, 213a) of the first and second guide inserts (212, 213) is in contact with the inner surface of the hole to be processed during processing to prevent vibration during processing of the drill.

In addition, the hole processed by the cutting insert 211 at the foremost end may be further thinned by the side surfaces 212a and 213a of the first and second guide inserts 212 and 213.

A first guide pad groove 217c and a second guide pad groove 218c are installed on the outer surface of the cutting body 210, and a first guide pad 217a and a first guide pad groove 217c are provided in the first guide pad groove 217c. The second guide pad 217b is provided with a third guide pad 218a and a fourth guide pad 218b in the second guide pad groove 218c.

The first guide pad 217a has two protrusions 217aa and 217ac, and a fixing part 217ab is formed between the two protrusions 217aa and 217ac, by the fixing part 217ab. The first guide pad 217a is fixed to the first guide pad groove 217c of the cutting body.

The outer surface of the protrusion becomes a contact surface in contact with the inner surface of the hole to be processed.

Similarly, the second guide pad 217b has two protruding portions 217ba and 217bc and a fixing portion 217bb, and is fixed to the first guide pad groove 217c.

In addition, the third and fourth guide pads 218a and 218b are also provided with two protrusions 218aa, 218ab; 218ba, 218bc and a fixing part 218ab; 217bb, and are fixed to the second guide pad groove 218c. do.

The first guide pad groove 217c and the second guide pad 218c exist at a position 90° around the central axis of the drill.

The protrusions 217aa, 217ac; 217ba, 217bc; 218aa, 218ac; 218ba, 218bc have a contact surface that contacts the inner surface of the hole to be processed, so that the position of the drill does not shake during drilling.

In particular, in the present invention, the contact surfaces of one side (212a, 213a) of the first and second guide inserts (212, 213) and the first and second guide pads are located in opposite directions (180°) with respect to the central axis of the drill. To prevent vibration during processing.

Cutting oil supply holes 215 and 218 through which cutting oil is provided are formed in the cutting body 210.

The above description is merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art to which the present invention pertains will be able to make various modifications and variations without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain the technical idea, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

100, 200: gun drill 10, 210: drill tip
20, 220: tube 30, 230: driver
211: cutting insert 212, 213: guide insert

Claims (2)

In the gun drill 200 including the cutting body 210,
The cutting body 210 is at least one guide having a V-shaped groove 214 consisting of a bottom surface 214a and a side surface 214b parallel to the drill center axis and a contact surface contacting the inner surface of the hole processed during drilling. Including pads 217a, 217b, 218a, 218b,
A square-shaped cutting insert 211 for machining a hole during drilling may be installed at the foremost end of the bottom surface 214a,
Any one corner 211a of the square is located at the foremost end of the cutting body 210,
The cutting insert 211 includes a first side surface 211b directed toward the inside of the V-shaped groove 214 at one of the corners 211a and a second side surface 211c directed toward the outside,
A square guide insert positioned at the rear of the cutting insert 211 is installed on the bottom surface 214a,
Gundrill using a square insert, characterized in that the bottom surface (214a) includes a first edge (214ad) on the outside parallel to the drill center axis.
The method of claim 1,
There are two guide inserts,
One side of the square shape of the guide insert is parallel to the first edge 214ad and is in contact with the inner surface of the hole processed during processing,
The second side 211c forms an angle of 30° to 50° with the first corner 214ad,
Gundrill using a square insert, characterized in that one side (212a, 213a) of the guide insert and the contact surface of the guide pad are located in opposite directions (180°) with respect to the central axis of the drill.

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