KR100421440B1 - A hole cutter and the manufacturing method of the hole cutter - Google Patents

Abstract

PURPOSE: A hole cutter and a hole cutter processing method are provided to improve the quality of products and mass-produce by adopting a drawing and notching method for shortening the operation time instead of a cutting operation by a lathe. CONSTITUTION: A hole cutter is composed of a cut body(1) having a cylindrical hollow container formed by drawing a circular steel plate, a cavity(13) of which the inner wall is a nut, formed at the bottom of the hollow container, and a plurality of cut-tip placing grooves(11) notched along the end of the rim of the hollow container; cut tips(3) placed and combined in the plural cut-tip placing grooves; a drill holder(5) of which one end is a shank(21) combined to a drill chuck, a bolt combined with the cavity of the cut body at the outer peripheral surface of the other end; a drill blade inserted and fixed to the center of the other end of the drill holder; and an insertion-preventing cap(9) of which the end is covered over the bottom of the cut body to protrude on the outer peripheral surface of the rim of the cut body, inserted and fixed to the other end of the drill holder.

Description

A hole cutter and the manufacturing method of the hole cutter}

The present invention relates to a hole cutter and a hole cutter processing method, and in particular, in preparing a cutting body in which a cutting tip is placed, a simple and efficient method such as drawing and notching instead of cutting by a lathe that requires a lot of working time and labor is required. The present invention relates to a hole cutter and a hole cutter processing method capable of improving the quality of the product as well as mass production.

In general, the hole cutter is a tool that is useful for making holes having a predetermined diameter or more in a plate of various materials such as a thin steel plate or a wooden door, and is used in a drilling machine that provides rotational force such as a drill gun.

1 is an exploded reference view illustrating a conventional hole cutter.

As shown in the drawing, the conventional hole cutter includes a cutting body 101 to which the cutting tip 103 is joined, a drill holder 105, and a drill blade 107.

As a result, the conventional hole cutter was able to cut a hole having a predetermined diameter or more on a plate such as wood or iron plate by the cutting tip 103 having a cutting edge formed while being mounted on a drilling machine such as a drill gun and rotating.

Here, the drill blade 107 is pre-inserted through the plate before the actual cutting of the plate by the cutting tip 103 to prevent the slip of the hole cutter instantaneously during the cutting of the plate do.

In addition, the protrusion 109 protruding from the outer circumferential surface of the cutting body 101 serves to prevent the cutting body 101 from falling into the cut hole.

However, in the conventional hole cutter, it was very difficult to provide a cutting body 101 which plays an important role in which the cutting tip 103 for forming a hole by cutting a sheet material is seated and bonded.

That is, in the related art, in order to provide the cutting body 101, a round bar was first prepared, and then a cylindrical hollow container shape was formed by precisely cutting one end surface of the round bar with a bite of a shelf.

Thereafter, providing a cavity for forming a female screw on the bottom surface of the hollow container and forming a plurality of cutting tips 103 seating grooves on the edge of the hollow container are performed by a cutting operation by a lathe. .

As such, in the related art, the cutting body 101 is prepared by cutting work using a lathe, and thus, a lot of skilled labor and work time are required. Therefore, quality such as precision of the product is lowered and mass production itself is impossible. There was a problem.

In addition, in order to prevent the cutting body 101 from completely falling into the cut hole, an insertion preventing protrusion 109 is formed on the outer circumferential surface of the cutting body 101.

In order to prevent being completely inserted into the inserted hole, an insertion preventing protrusion 109 is provided on the outer circumferential surface of the cutting body 101, which is also provided by cutting the outer circumferential surface of the cutting body 101 with the bite of the lathe.

As such, in the related art, since a cutting body 101 is mainly provided depending on a cutting operation of a lathe, processing time is very large, and mass production of the product itself is impossible, quality is degraded, and a considerable amount of processing is difficult during processing. There was a problem that the cutting chip is generated.

In addition, in the related art, in order to prevent the cutting body 101 from falling into the cut hole in an instant, the insertion preventing protrusion 109 protruding from the outer circumferential surface of the cutting body 101 is also cut in the manner of cutting the outer circumferential surface of the round bar with the bite of the lathe. As a result, the problems caused by the lathe work as described above,

In addition, since the insertion preventing protrusion 109 is formed integrally with the cutting body 101, it is inevitable to take it even if a predetermined damage caused by the insertion preventing protrusion 109 is expected. there was.

Meanwhile, in the conventional hole cutter processing method, it is difficult to process the periphery of the cavity, which is essentially formed in the cutting body 101, for the coupling with the drill holder 105, so that the solid treatment is performed. There was a problem that the weight increases.

Accordingly, the present invention has been proposed to solve the conventional problems as described above, the object of the present invention is to eliminate the cutting work by the lathe that takes a lot of work time and skilled labor, work time such as drawing and notching It is to provide a hole cutter and a hole cutter processing method that can improve the quality of the product as well as mass production by using a simple and easy way to be reduced.

In addition, another object of the present invention, the insertion preventing means provided to prevent the cutting body from being instantaneously pulled out of the cut hole of the plate material is detachable from the cutting body, it is essentially formed in the cutting body to be combined with the drill holder The present invention provides a hole cutter and a hole cutter processing method in which the periphery of the cavity is hollowed.

1 is an exploded view showing a conventional hole cutter.

2 is a reference diagram showing a state in which the hole cutter of the present invention is used.

3 is an elevation view of a hole cutter of the present invention.

Figure 4 is an exploded perspective view showing the configuration of the hole cutter of the present invention.

5 is a reference view showing the role of the insertion prevention cap of the present invention.

Figure 6 is a flow chart showing step by step the hole cutter processing method of the present invention.

7A and 7B are reference views showing a state in which a circular iron plate is drawn.

7C is a diagram showing the state in which the cutting body is punched out.

7D is a reference diagram showing how the cutting body is notched;

8 is a reference diagram showing a state in which the hole cutter is processed by each step according to the hole cutter processing method of the present invention in order.

9 is a flow chart showing step by step the hole cutter processing method of the present invention according to a modified embodiment.

10 is a reference view showing a cutting tip seating groove is formed in a circular iron plate

* Description of the symbols for the main parts of the drawings *

1: cutting body 3: cutting tip

5: drill holder 7: drill blade

9: Insertion prevention cap 11: Cutting tip seating groove

In order to achieve the above object, the hole cutter according to the technical concept of the present invention, a circular iron plate is drawn to form a cylindrical hollow container, the bottom surface of the hollow container is formed with a cavity having a female screw inner wall, the hollow container A cutting body notched with a plurality of cutting tip seating grooves along the edge of the edge of the cutting body, a cutting tip seated and joined to each of the plurality of cutting tip seating grooves, and one end is formed with a shank coupled to a drill chuck, and the other end outer peripheral surface It includes a drill holder is formed with a male thread coupled to the cavity of the cutting body, and a drill blade is fitted in the center of the other end of the drill holder.

Here, it is preferable that the end is further provided with an insertion prevention cap which is covered with the lower end of the cutting body so as to protrude to the outer peripheral surface of the cutting edge, and is fitted to the other end of the drill holder.

On the other hand, the hole cutter processing method of the present invention comprises the steps of: blanking a predetermined iron plate to provide a circular iron plate, drawing a blanked circular iron plate to prepare a cutting body having a hollow container shape, and the cutting body Piercing and punching the center of the bottom of the bottom to form a through hole; punching the pierced through hole to form a cavity to have an inner wall of a predetermined length; and tapping an inner wall of the cavity formed by bearing to punch a female screw. And forming a plurality of cutting tip seating grooves by notching the edges of the cutting body, and seating and bonding the cutting tips to the respective cutting tip seating grooves formed in the cutting body; Grinding the cutting edge by grinding the cutting tip bonded to the tip seating groove, and tapping the outer peripheral surface of the other end of the drill holder with a shank at one end Forming a male screw corresponding to the female screw of the inner wall of the pupil formed in the body, and fixing the drill blade in the longitudinal direction at the center of the other end of the drill holder; and the male screw and the cutting body of the drill holder in which the drill blade is fixed. Combining the female screw of the drill holder and the cutting body is configured to include.

In addition, blanking a predetermined iron plate to provide a circular iron plate, cutting the edges of the circular iron plate to form a plurality of cutting tip seating grooves, and drawing a circular iron plate cutting to have a hollow container shape Providing a sieve, piercing and punching a center of the bottom surface of the cutting body to form a through hole, and forming a cavity to have an inner wall of a predetermined length by burring and punching the pierced through hole. Tapping the inner wall of the formed cavity to form a female screw, and mounting and cutting a cutting tip into each cutting tip seating groove formed in the cutting body, and grinding the cutting tip bonded to the cutting tip seating groove. Grinding the cutting edge, and tapping the outer circumferential surface of the other end of the drill holder having the shank formed at one end thereof with a female screw of the inner wall of the pupil formed in the body; Forming a combined male screw, fixing the drill blade in the longitudinal direction of the center of the other end of the drill holder, and coupling the male screw of the drill holder to which the drill blade is fixed and the female screw of the cutting body to connect the drill holder to the drill holder. It may be configured to include a cutting body and the cutting body.

Here, after the step of forming a male screw on the other end of the drill holder, the step of blanking a predetermined iron plate to provide a circular iron plate, by drawing a blanked circular iron plate to prevent the insertion to be covered in accordance with the bottom surface of the cutting body The method may further include providing a cap, forming a through hole by piercing and punching a center of an upper surface of the insertion prevention cap, and covering the insertion prevention cap with a bottom surface of the cutting body.

Hereinafter, an embodiment according to the spirit of the present invention as described above will be described in detail with reference to the accompanying drawings.

2 is a reference diagram showing how the hole cutter of the present invention is used.

As shown, the hole cutter 100 of the present invention is mounted on a rotating drill chuck 130 of a drilling machine 200 such as a drill gun, and used to cut a hole having a predetermined diameter or more in a plate such as an iron plate. .

Here, while the hole cutter 100 of the present invention is structurally light, it is easy to work such as drawing and notching instead of cutting by a lathe, which requires a lot of working time and skilled labor. Working time is processed in such a way as to minimize it.

Hereinafter, the configuration of the hole cutter 100 of the present invention will be described in detail.

3 is an elevation view of the hole cutter of the present invention.

As shown, the hole cutter of the present invention includes a cutting body 1, a cutting tip 3 seated on the cutting body 1, a drill holder 5, and a drill blade 7. It is composed.

In addition, it is preferable that the insertion prevention cap 9 is further provided.

Hereinafter, the structure which the hole cutter of this invention has is demonstrated in detail.

Figure 4 is an exploded perspective view showing the configuration of the hole cutter of the present invention.

As shown, the hole cutter of the present invention includes a hole cutter, a cutting body 1, a cutting tip 3, a drill holder 5, and a drill blade 7.

Here, the cutting body 1 is a circular iron plate 51 is drawn to form a cylindrical hollow container, that is, a cylindrical container shape of which one end surface is open and hollow inside.

In addition, the cutting body 1 is formed with a cavity 13 having a female inner thread on the inner wall of the bottom surface of the hollow container, and is formed by notching a plurality of cutting tip seating grooves 11 along the end of the edge of the hollow container.

Here, the cavity 13 is formed by forming a through hole by piercing (Piercing) punching the center of the bottom of the hollow container prepared by drawing a circular iron plate (51), and then punching the through hole (Burring) formed will be..

Thus, the cavity 13 has both an inner wall and an outer wall and its periphery has a hollow cylindrical shape.

Thus, in the conventional cutting operation of the lathe to solve the problem that the weight of the hole cutter was unnecessarily large due to the solid treatment instead of the periphery of the cavity 13 to form a cavity 13 having a female thread. It can be solved.

In addition, the cutting tip seating groove 11 formed by being notched to the cutting body 1 is formed with a predetermined margin in addition to the portion where the cutting tip 3 is seated. This is because the cutting chip generated when the plate is cut by the cutting tip 3 is easily discharged so that the hole cutting operation is not disturbed.

In addition, the cutting tips 3 are seated and bonded to the plurality of cutting tip seating grooves 11 formed in the cutting body 1, respectively.

Here, the cutting tip 3 is formed with a cutting edge 15 for contacting and cutting the plate at the end and a reliable joining method such as welding so as not to fall off from the cutting body 1 even if the plate is repeatedly cut. It is firmly joined by.

In addition, one end of the drill holder 5 is formed of a shank 21 coupled to the drill chuck, and an external thread 23 coupled to the cavity 13 of the cutting body 1 is formed at the outer peripheral surface of the other end. .

In addition, one end 31 of the drill blade 7 is fitted into the center of the other end of the drill holder 5 and the other end is formed of a perforated blade 29.

Here, the fixing means 25 for fixing the drill blade 7 to the drill holder 5 is provided, the insertion hole 27 for connecting to the drill blade 7 at the same time the fixing means 25 is fixed ) Is formed through a portion of the outer wall of the drill holder (5) to a predetermined depth.

The drill blade (7) is to be inserted in advance through the plate before the full cutting of the plate by the cutting tip (3) serves to prevent the phenomenon that the hole cutter during the cutting of the plate instant slip.

On the other hand, the hole cutter of the present invention may further include an insertion prevention cap (9).

Here, the insertion prevention cap (9) is covered with a lower end portion of the cutting body (1) so that the end (19) protrudes on the outer peripheral surface of the cutting body (1), a fixing cylinder (17) is formed for fixing and the It is fitted to the other end of the drill holder (5) by a fixing cylinder (17).

With such a configuration, the insertion prevention cap 9 serves to prevent the cutting body 1 from falling into the cut hole of the plate.

Thus, Figure 5 is a reference diagram showing the role of the insertion prevention cap of the present invention.

As shown, the anti-insertion cap 9 of the present invention allows the cutting body 1 to instantly fall into the cut hole of the sheet by the end 19 protruding to the outer circumferential surface of the cutting body 1. It can be prevented.

In other words, in order to make a hole in a plate by using a hole cutter, cutting is performed while applying a predetermined force in the plate direction. The cutting body is cut into the hole cut by the force pushing in the plate direction when the plate is cut and finally formed. The end portion 19 of the insertion prevention cap 9 is prevented from being swept away from the periphery of the hole (1).

On the other hand, the insertion prevention cap 9 is easy to assemble and separate because it is not formed integrally with the cutting body (1).

As such, since the insertion prevention cap 9 is detachable, it is often possible to prevent the damage that the insertion prevention cap 9 can cause.

For example, in the case of making a hole in a plate made of a weak material, which is easy to be damaged, the insertion preventing cap 9 may collapse the periphery of the cut hole by a force pushing toward the plate at the moment when the hole is finally formed. In this case, the insertion prevention cap 9 is to be separated to prevent damage.

In addition, the cutting tip 3 is easily worn by the repeated hole cutting operation, thereby replacing the cutting tip 3 as well as the cutting body 1 to which the cutting tip 3 is firmly bonded.

At this time, since the insertion preventing cap 9 of the present invention can be separated from the cutting body 1, it can be used semi-permanently without replacing the cutting body 1 and the cutting tip 3, unlike the prior art. .

Subsequently, the hole cutter processing method of the present invention will be described step by step.

Figure 6 is a flow chart showing the hole cutter processing method of the present invention step by step, Figure 7a, 7b is a reference diagram showing a state in which a circular iron plate is drawn, Figure 7c is a degree of severity showing the state in which the cutting body is punched bearing FIG. 7D is a reference diagram illustrating a state in which a cutting body is notched, and FIG. 8 is a reference diagram sequentially showing a state in which a hole cutter is processed by each step according to the hole cutter processing method of the present invention.

As shown, the hole cutter processing method of the present invention, the step of providing a round iron plate (S101), the step of providing a hollow vessel-shaped cutting (S102), and forming a through hole in the cutting body (S103), forming a cavity in the cutting body (S104), forming a female screw in the cavity of the cutting body (S! 05), and forming a cutting tip seating groove (S106), Step (S107) of seating and joining the cutting tip in the cutting tip seating groove, step (S108) of grinding the cutting tip, forming a male screw in the drill holder (S109), and fixing the drill blade to the drill holder It comprises a step (S110), and a step (S111) for coupling the cutting body and the drill holder.

Here, in the step (S101) of providing a circular iron plate 51, a predetermined iron plate is blanked to provide a circular iron plate 51 of an appropriate size.

Thereafter, a step (S102) of preparing a preliminary cutting body having a cylindrical hollow container shape is performed.

In this step S102, by drawing the circular iron plate 51, the cutting body 1 which has a hollow container shape is provided.

Referring to FIGS. 7A and 7B, while the circular iron plate 51 is fixed to the drawing die 53 and the fixing pad 55 with a predetermined force, the circular iron plate 51 is simultaneously contacted by the drawing punch 57. It fires by the cutting body 1 which has a cylindrical hollow container shape.

Here, the method by the drawing as described above is possible to work very quickly compared to the conventional way to form a hollow container by cutting the round bar with the bite of the shelf, it will not cause unnecessary cutting chips that occur incidentally.

Thereafter, step S103 of forming a through hole in the cutting body is performed.

In this step S103, the center of the bottom surface of the cutting body 1 having a hollow container shape is pierced and punched to form a through hole.

Here, the through hole formed in the cutting body 1 is to have a smaller diameter than the cavity 13 to be formed later.

Thereafter, a step (S104) of forming a cavity in the cutting body in which the hole is formed is performed.

Referring to FIG. 7C, in this step S104, the bearing punch 59 and the bearing punch die 61 interact with each other to burr the pierced through-hole, thereby removing an inner wall of a predetermined length from the through-hole. The cavity 13 is formed.

Here, when the bearing punch 59 presses the center portion of the bottom surface of the cutting body 1 where the through hole formed by piercing is located, the periphery of the through hole is deformed and fired into the cavity 13 having an inner wall of a predetermined length.

As such, when the cavity 13 is formed by the burring punching, the periphery of the cavity 13 can be formed hollow so that the weight of the product can be significantly reduced.

Thereafter, step S105 of forming a female screw in the cavity of the cutting body is performed.

In this step (S105), tapping the inner wall of the cavity 13 formed by bearing punching to form a female screw.

Thereafter, a step (S106) of forming a cutting tip seating groove in the cutting body is performed.

Referring to FIG. 7D, in this step S106, the edge end of the cutting body 1 is formed by the reciprocating notching punch 65 while rotating the cutting body 1 to the rolling notching die 63. By notching, a plurality of cutting tip seating grooves 11 are formed.

As such, the method of forming the cutting tip seating groove 11 by notching has excellent precision as compared to the method of forming the cutting tip seating groove 11 by cutting work of a lathe in the past, and is easy to work. The time spent on it is also much shorter.

Thereafter, the step S107 of mounting and bonding the cutting tip to the cutting tip seating groove is performed.

In this case, the cutting tip 3 should be firmly bonded to the cutting tip seating groove 11 to sufficiently endure the repeated external force received while cutting the plate, and a reliable bonding method such as welding is used for this purpose. do.

Thereafter, the step S108 of grinding the cutting tip is performed.

In this step (S108), by cutting the end of the cutting tip (3) bonded to the cutting tip seating groove (11) it is polished with the cutting edge (15) for cutting while substantially in contact with the plate.

Thereafter, a step S109 of forming a male screw in the drill holder is performed.

In this step (S109), tapping the outer peripheral surface of the other end of the drill holder 5, the shank 21 is formed at one end to form a male screw 23 corresponding to the female screw of the inner wall of the pupil formed on the body.

As a result, the drill holder 5 and the cutting body 1 are coupled to each other.

Thereafter, a step (S110) of fixing the drill blade to the drill holder is performed.

In this step (S110), the drill blade 7 is inserted into the center of the other end of the drill holder 5 in the longitudinal direction and fixed. For this purpose, a predetermined portion for fixing the drill holder 5 and the drill blade 7 is fixed. Fixing means 25 may be used.

Finally, the step (S111) of combining the cutting body and the drill holder is performed.

In this step (S111), the drill holder 5 is coupled to the male screw 23 of the drill holder 5 to which the drill blade 7 is fixed and the female screw formed in the cavity 13 of the cutting body 1. And the cutting body 1 are combined.

This results in a complete hole cutter with each component fully assembled.

Here, the present invention may further include the following steps to form the male screw in the drill holder (S109), to have an insertion prevention cap (9).

That is, the step of blanking a predetermined iron plate to provide a circular iron plate, the step of drawing a blanked circular iron plate to provide an insertion prevention cap which is covered in accordance with the bottom surface of the cutting body, and the top surface of the insertion prevention cap The method may further include forming a through hole by piercing and punching a center, and covering the insertion prevention cap on the bottom surface of the cutting body.

Thereafter, as described above, the step of fixing the drill blade to the drill holder (S110) and the step of combining the cutting body and the drill holder (S111) are the same.

On the other hand, the hole cutter processing method of the present invention can be carried out in a modified manner to form a cutting tip seating groove 11 immediately in the circular iron plate 51, immediately after providing the circular iron plate (51).

Accordingly, FIG. 9 is a flowchart showing a hole cutter processing method of the present invention according to a modified embodiment step by step, and FIG. 10 is a reference view showing a cutting tip seating groove formed on a circular iron plate.

As shown, the hole cutter processing method of the present invention according to the modified embodiment (S201) to prepare a circular iron plate, the step of forming a cutting tip seating groove (S202), and a hollow vessel-shaped cutting body Preparing (S203), forming a hole in the cutting body (S204), forming a cavity in the cutting body (S205), and forming a female screw in the cavity of the cutting body (S206). And, the step of mounting and bonding the cutting tip to the cutting tip seating groove (S207), the step of grinding the cutting tip (S208), the step of forming a male screw in the drill holder (S209), and the drill blade in the drill holder It comprises a step (S210) for fixing, and a step (S211) for coupling the cutting body and the drill holder.

Here, in the step (S202) of forming the cutting tip seating groove to proceed after the step (S201) of providing a circular iron plate, the cutting tip seating groove 11 is formed directly in the circular iron plate (51).

In this step (S202), a plurality of cutting tip seating grooves 11 are formed by cutting the end portions of the edges of the circular iron plate 51 provided with blanking as shown in FIG.

As described above, according to the method of directly forming the cutting tip seating grooves 11 in the circular iron plate 51, the cutting tip seating grooves 11 can be formed at a time by a cutting machine having a plurality of punching blades. .

Therefore, the operation is simpler and faster than the method of notching the cutting tip seating grooves 11 one by one while rotating the cutting body 1 that has already been fired in the shape of a cylindrical hollow container by a notching die.

However, in the case of forming the cutting tip seating grooves 11 directly in the circular steel plate 51 in this way, considering the slight deformation that may be present when the circular steel plate 51 is fired in the shape of a cylindrical hollow container, appropriately The cutting tip seating groove 11 should be formed.

The preferred embodiment of the present invention has been described above. The present invention may use various changes, modifications, and equivalents. It is clear that the present invention can be applied in the same manner by appropriately modifying the above embodiments. Accordingly, the above description does not limit the scope of the invention as defined by the limitations of the following claims.

As described above, the hole cutter and the hole cutter processing method according to the present invention are simple, such as drawing and notching, in which work time is reduced instead of cutting work by a lathe, which requires a lot of working time and labor in providing a cutting body. The efficient method is used to improve the quality of the product as well as to mass production.

In addition, it is possible to significantly reduce the production cost of the above reason.

In addition, the present invention prevents the problem that can be caused by the insertion prevention cap, as well as the wear prevention is severe because the insertion prevention cap, which is an insertion prevention means provided to prevent the cutting body from falling into the cut hole is selectively removable When replacing the cutting tip and the cutting body can be used semi-permanently without replacement, thereby reducing the maintenance cost.

Claims (5)

A circular iron plate is drawn to form a cylindrical hollow container, and a bottom surface of the hollow container is formed with a cavity having a female thread, and a cutting body in which a plurality of cutting tip seating grooves are notched along an end of the rim of the hollow container; Cutting tips respectively seated and bonded in the plurality of cutting tip seating grooves; A drill holder having one end formed with a shank coupled to the drill chuck, and the other end outer peripheral surface having a male screw coupled with a cavity of the cutting body; A drill blade fixed to a center of the other end of the drill holder; And an insertion prevention cap which is covered with a lower end of the cutting body so that an end thereof protrudes from the outer peripheral surface of the cutting edge, and is inserted into and fixed to the other end of the drill holder. delete Blanking a predetermined iron plate to provide a circular iron plate; Drawing a blanked circular iron plate to prepare a cutting body having a hollow container shape; Piercing and punching a center of a bottom surface of the cutting body to form a through hole; Burring and punching the pierced through-hole to form a cavity having an inner wall of a predetermined length; Tapping the inner wall of the cavity formed by bearing punching to form a female screw; Notching the edges of the cutting body to form a plurality of cutting tip seating grooves; Mounting and bonding a cutting tip to each cutting tip seating groove formed in the cutting body; Grinding the cutting edge bonded to the cutting tip seating groove to polish the cutting edge; Tapping at one end the outer peripheral surface of the other end of the shank-shaped drill holder to form a male screw corresponding to the female screw of the inner wall of the pupil formed in the body; Fixing the drill blade to a center of the other end of the drill holder in a lengthwise direction; And coupling the drill holder and the cutting body by engaging the male screw of the drill holder with the drill blade fixed thereto and the female screw of the cutting body. Blanking a predetermined iron plate to provide a circular iron plate; Cutting edges of the round iron plate to form a plurality of cutting tip seating grooves; Drawing a round iron plate to prepare a cutting body having a hollow container shape; Piercing and punching a center of a bottom surface of the cutting body to form a through hole; Burring and punching the pierced through-hole to form a cavity having an inner wall of a predetermined length; Tapping the inner wall of the cavity formed by bearing punching to form a female screw; Mounting and bonding a cutting tip to each cutting tip seating groove formed in the cutting body; Grinding the cutting edge bonded to the cutting tip seating groove to polish the cutting edge; Tapping at one end the outer peripheral surface of the other end of the shank-shaped drill holder to form a male screw corresponding to the female screw of the inner wall of the pupil formed in the body; Fixing the drill blade to a center of the other end of the drill holder in a lengthwise direction; And coupling the drill holder and the cutting body by engaging the male screw of the drill holder with the drill blade fixed thereto and the female screw of the cutting body. The method according to claim 3 or 4, After forming a male screw on the other end of the drill holder, blanking a predetermined iron plate to provide a circular iron plate; Drawing a blanked round iron plate to provide an insertion prevention cap which is covered in conformity with the bottom surface of the cutting body; Piercing and punching the center of the upper surface of the insertion prevention cap to form a through hole; And a step of covering the insert prevention cap on the bottom surface of the cutting body.