KR102223956B1 - Twist Gun Drill - Google Patents

Abstract

The present invention relates to a drill, which includes a V-shaped groove (50) for discharging machining chips generated during drilling, and a machining chip discharging unit (40) intersecting the V-shaped groove (50). The V-shaped groove (50) includes a bottom surface (51) and a side surface (52) parallel to the central axis of the drill. The machining chip discharging unit (40) includes a first plane (41) on which an inner cutting insert (10) for inner machining is mounted, and a spiral-shaped flute (43) connected to the first plane (41). The bottom surface (51) of the V-shaped groove (50) includes an outer cutting insert (20) disposed at the foremost end and a guide insert (30) disposed at the rear of the cutting insert (20), and one side (21, 31) of the outer cutting insert (20) and the guide insert (30) are arranged parallel to the central axis of the drill. According to the present invention, an insert in contact with the inner surface of a hole to be machined is additionally installed so that a cutting body does not vibrate during machining.

Description

Twist Gun Drill

The present invention relates to a drill in which a spiral flute and a V-shaped groove for discharging processing chips of a material cut by a drill cross each other.

1 and 2 are perspective views of a conventional gun drill 200. The gun drill 200 is generally composed of a cutting body 210, a tube 220, and a driver 230, and is cut by the cutting body 210. The processing chips of the material are discharged through the V-shaped groove 211.

The gun drill has a V-shaped groove 211, a contour 212 in contact with the processing hole, a relief 213 having a diameter smaller than that of the contour 212, and a cutting portion 214 for processing the hole.

The contour 212 is in contact with the inner surface of the hole being processed so that the cutting body 210 can be supported in the processing hole, and the relief 213 does not contact the processing hole unlike the contour 212 so that the cutting body 210 is processed. Allows rotation in the hole.

If there is only the contour 212 without the relief 213 on the outer circumferential surface of the cutting body 210, the cutting body 10 will be interlocked with the machining hole, making it impossible to rotate.

Carbide, the 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. do.

In addition, when using the gun drill for a certain period of time, it must be ground again due to abrasion of the cutting part to erect the blade.

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.

Accordingly, the present invention is to be applied to a gun drill using a square-shaped insert.

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

In the present invention, while using a square insert as an outer cutting insert and an inner cutting insert, the processing chips formed by the inner cutting insert are discharged by the spiral-shaped flute, and the processing chips formed by the outer cutting insert are V It is intended to be able to be applied to drills, especially gun drills, with square inserts that are mass-produced by discharging them by means of a shaped groove.

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 processed so that vibration does not occur in the drill 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. It is intended to be supported by the inner surface and thereby prevent vibration during processing.

In addition, in the present invention, the square inner cutting insert is inclined and protruded from the end surface of the drill at a certain angle, thereby reducing the difference in the amount of being cut by the inner cutting insert and the outer cutting insert, thereby reducing vibration during processing. , We want to make the most of the four sides of the inner cutting insert and the outer cutting insert.

The present invention includes a V-shaped groove 50 for discharging processing chips generated during drilling and a processing chip discharge unit 40 crossing the V-shaped groove 50, wherein the V-shaped groove 50 is It includes a bottom surface 51 and a side surface 52 parallel to the drill center axis, and the processing chip discharge part 40 includes a first plane 41 on which an inner cutting insert 10 for internal processing is mounted, and the Includes a spiral-shaped flute 43 connected to the first plane 41, and the outer cutting insert 20 and the cutting insert disposed at the foremost end on the bottom surface 51 of the V-shaped groove 50 Including a guide insert 30 disposed at the rear of (20), the outer cutting insert (20) and one side (21, 31) of the guide insert (30) are arranged parallel to the central axis of the drill It relates to a characterized drill.

In addition, in the present invention, the drill includes an end surface 91 in a processing direction, and the inner cutting insert 10 protrudes from the end surface 91 and is inclined with the end surface. 41).

In addition, in the present invention, the first side surface 11 at the foremost end of the inner cutting insert 10 may form an angle of 10° to 20° with the end surface 91.

In addition, in the present invention, the first plane 41 may be deviated from the bottom surface 51 at an angle of 15° to 30°.

In addition, in the present invention, the first guide pad 60 may be additionally disposed at a position opposite to each other with the guide insert 30 around the central axis of the drill.

In addition, in the present invention, the second guide pad 70 may be disposed at a position 90° from the first guide pad 60 about the drill center axis.

In the present invention, while using a square insert as an outer cutting insert and an inner cutting insert, the processing chips formed by the inner cutting insert are discharged by the spiral-shaped flute, and the processing chips formed by the outer cutting insert are V It is possible to reduce production cost and maintenance cost by making it possible to apply a square insert made in mass production to a drill, especially a gun drill by discharging it by a shaped groove.

In addition, in the present invention, an insert that contacts the inner surface of the hole to be machined is additionally installed to prevent the cutting body from vibrating 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. It is made to play a supporting role on the inner surface and thereby prevent vibration during processing.

In addition, in the present invention, by making the square inner cutting insert protrude from the tip of the drill at a certain angle, the difference between the amount of the inner cutting insert and the outer cutting insert is reduced, thereby reducing vibration during processing, and It is possible to make the most of the four sides of the cutting insert and the outer cutting insert.

1 is a perspective view of a conventional gun drill.
2 is a perspective view of a cutting body 10 of a conventional gun drill.
3A and 3B are plan and side views of the drill according to the present invention.
4A and 4B are views in which FIGS. 3A and 3B are rotated by 90°.
5A to 5C are three-dimensional perspective views of the present invention.
6A and 6B are comparative diagrams for explaining the anti-vibration effect of the present invention.
7A and 7B are comparative diagrams for explaining the effect of insert utilization according to the present invention.

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

The accompanying drawings show exemplary forms of the present invention, which are only provided to describe the present invention in more detail, and thus the technical scope of the present invention is not limited thereto.

3A and 3B are a plan view and a side view of the drill of the present invention, FIGS. 4A and 4B are views rotated by 90°, and FIGS. 5A to 5C are three-dimensional perspective views of the present invention, do.

In the drill of the present invention, a V-shaped groove 50 having a bottom surface 51 and a side surface 52 parallel to the longitudinal axis of the drill (hereinafter, referred to as “drill center axis”) is formed.

In addition, a processing chip including a first plane 41 parallel to the drill central axis and a spiral flute 43 connected to the first plane 41 on the opposite side of the V-shaped groove 50 with respect to the drill central axis The discharge part 40 is formed.

The flute 43 is manufactured in a spiral shape so that the V-shaped grooves 50 meet, as can be seen in FIGS. 3A and 4A.

An outer cutting insert 20 is installed at the foremost end of the bottom surface 51, and an inner cutting insert 10 is installed on the first plane 41.

The first plane 41 has a first edge 41a formed at a point where it meets the end surface 91, and the first side 11 positioned at the foremost end of the inner cutting insert 10 is the first The inner cutting insert 10 is installed to protrude obliquely with respect to the end face 91 while forming the edge 41a and 10° to 20°, preferably 15°.

In addition, the bottom surface 51 and the first plane 41 of the V-shaped groove 50 are formed to be inclined to each other as shown in FIG. 5B, and are preferably set to be 20°.

In addition, a first guide pad 60 is installed on the opposite side of the bottom surface 51 with respect to the central axis of the drill.

A guide insert 30 is installed at the rear of the outer cutting insert 20 on the bottom surface 51, and the first side surface 31 of the guide insert 30 and the outer cutting insert 20 are 1 side (21) is installed on the bottom surface (51) parallel to the drill center axis.

The guide insert 30 is arranged in parallel with the outer cutting insert 20 to reduce the vibration of the drill while the first side 31 of the outer cutting insert 20 contacts the inner surface of the hole being processed. .

The line passing through the center of the first guide pad 60 and the first bottom surface 51 passes through the center axis of the drill as shown in FIG. 5B, so that the first guide pad 60 and the guide insert 30 are formed during drilling. ) Is to prevent the vibration of the drill by supporting the inner surface of the machining hole on opposite sides of each other.

The first plane 41 is 15° to 30°, more preferably 20 to the bottom surface 51 so that the first guide pad 60 can be disposed at a position opposite to each other. It is necessary to deviate at an angle of °.

In addition, since the second guide pad 70 is installed at a position 90° from the first bottom surface 41 around the drill center axis, the second guide pad 70 also contacts the inner surface of the hole processed during processing. This prevents vibration.

6A to 6B are views for explaining the effect of the case in which the inner cutting insert 10 is inclined by 15° with respect to the end face 91 in the present invention.

6A is a first region processed by only the outer cutting insert 120 when the inner cutting insert 110 and the outer cutting insert 120 are positioned in parallel, and the drawing number Reference numeral 140 denotes a second region processed by the inner cutting insert 110 and the outer cutting insert 12, and reference numeral 150 denotes a third region processed by the inner cutting insert 110.

In this case, since the first region 130 has a larger radius than the third region 150, the first region 130 is larger in a ratio of about 3.9:1.

That is, since the amount cut by only the outer cutting insert 120 is 3.9 times higher than the amount cut by only the inner cutting insert 120, a lot of vibration occurs.

In contrast, when the inner cutting insert 10 is inclined at an angle of 15°, as shown in FIG. 6B, the first side 11 of the inner cutting insert 10 protrudes compared to the end surface 91 and The area machined by the second side surface 12 does not need to be machined by the outer cutting insert 20.

That is, in the state of FIG. 6B, the second region 140 in FIG. 6A disappears and is divided into an insert processing region 250 for inner cutting and an insert processing region 230 for outer cutting.

The ratio of the outer cutting insert processing area 230 and the inner cutting insert processing area 250 is 2.45: 1 times, which reduces the ratio of the cutting amount compared to the case where they are arranged side by side as shown in FIG. 6A, thereby reducing vibration. have.

In addition, as shown in Fig. 7a, when the inner cutting insert 110 and the outer cutting insert 120 are arranged side by side, the first side surfaces 111 and 121, the first corners 111a and 121a, and the first 2 The edges 112a and 122a are worn.

When the edge is worn, the cutting insert cannot be used, so in the case of FIG. 7A, only the side surface 123 opposite to the first side surface 111 and 121 can be used once more.

In contrast, when the inner cutting insert 10 is inclined by 10 to 20° as shown in FIG. 7B, some of the first side surfaces 11 and 21 of the inner and outer cutting inserts 10 and 20, and the second edge 12a , 22a) and only a portion of the second side surfaces 12 and 22 are worn, so a total of 4 times can be used while rotating by 90°.

In this way, when the inner insert is inclined by 10 to 20° compared to the end surface, vibration can be reduced and the utilization of the guide insert can be increased.

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 (4)

It includes a V-shaped groove 50 for discharging processing chips generated during drilling and a processing chip discharge unit 40 crossing the V-shaped groove 50,
The V-shaped groove 50 includes a bottom surface 51 and a side surface 52 parallel to the drill center axis,
The processing chip discharging part 40 includes a first plane 41 on which an inner cutting insert 10 for inner processing is mounted and a spiral flute 43 connected to the first plane 41,
The bottom surface 51 of the V-shaped groove 50 includes an outer cutting insert 20 disposed at the foremost end,
One side (21, 31) of the outer cutting insert (20) is arranged parallel to the central axis of the drill,
The drill includes an end surface 91 in the direction of processing progress,
The inner cutting insert 10 protrudes from the end surface 91 and is disposed on the first plane 41 to be inclined with the end surface,
The first side surface 11 at the foremost end of the inner cutting insert 10 forms an angle of 10° to 20° with the end surface 91,
Drill, characterized in that the first plane 41 is deviated from the bottom surface 51 at an angle of 15° to 30°.
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