KR20050007099A - Cutting head changing type cutting tool - Google Patents

Abstract

PURPOSE: A cutting tool for replacing a cutting head is provided to increase the rigidity of the cutting head by discharging coolant oil sufficiently without forming the coolant discharge hole, and to fasten the cutting head to the body accurately by integrating the center with the cross assembling projection and the cross assembling groove. CONSTITUTION: A cutting tool is composed of a body(10) having a cross assembling projection protruded in the front, a coolant pipe formed from the rear end to the front to flow coolant oil for cooling heat in cutting and a chip discharge groove(13) discharging the cut chip in the outer periphery, a cutting head(20) having a cross assembling groove for inserting the assembling projection of the body, a cutting blade for processing the hole and a chip discharge groove(23) connected to the chip discharge groove of the body, and an assembling member combined with the body by the cutting head to fasten the cutting head to the body and composed of a coolant discharge hole communicated with the coolant pipe of the body to discharge coolant oil to the cutting portion.

Description

Cutting head changing type cutting tool

The present invention relates to a cutting tool used to drill a hole in a workpiece, and in particular, it is possible to replace the cutting head, the center is exactly matched when the cutting head is coupled to the body, the cutting head is firmly fixed to the body The present invention relates to a cutting head replaceable cutting tool.

In general, a drill is mainly used as a cutting tool for drilling holes in a workpiece. This drill is mainly used for drilling holes in metal and used in drilling machines or electric drills, but it is sometimes used in hand drills (ratchet drills) to drill holes by manual operation.

These drills are typically drilled using a cutting head integrally formed at the tip, which wears out after long use. Therefore, the user re-grinds the blade formed on the cutting head when the cutting head is worn, and replaces the drill itself when it is no longer possible to regrind.

However, as described above, since the drill itself is used in exchange, a lot of cost is required. In recent years, a throwaway type cutting method is used in which the main body and the cutting head are separately formed, the main body is used as it is, and only the cutting head is replaced. Tools have been developed and used.

Conventional techniques for the throwaway cutting tool as described above have been disclosed in Korean Utility Model Registration No. 0193291, Korean Patent Publication No. 2002-0043219 and US Patent 4950108.

First, the cutting tool disclosed in the Republic of Korea Utility Model Registration No. 0193291 is formed so that the center of the body and the cutting head is coincident by forming a circular protrusion on the cutting head and inserting the protrusion into a cylindrical fitting hole formed on the front end surface of the main body. Precise machining of the fitting holes is required to exactly match the center of the body and the cutting head. In addition, since a cooling oil duct for cooling heat generated at the cutting part is formed on the outer circumferential surface of the circular protrusion of the cutting head, if a small gap is generated between the circular protrusion and the fitting hole, some of the cooling oil supplied to the cutting part leaks to the outside. There is a risk of leaving.

In addition, the cutting tool disclosed in Korean Patent Laid-Open Publication No. 2002-0043219 forms a plurality of protrusions formed in a 'V' shape on the engaging surface of the main body and the cutting head, and is formed to be engaged with each other, so that the plurality of protrusions are not precisely processed. Otherwise, the coupling between the tool body and the cutting head will not work properly. In addition, since the projections are formed to gradually increase toward the outer periphery, in order for the main body and the cutting head to be accurately engaged, the processing becomes complicated as the height of each projection and the groove between the projections must be constant. In addition, since a hole through which a bolt for fixing the cutting head to the main body and a hole through which cooling oil is discharged are formed on the cutting head, there is a problem in that the strength of the cutting head is lowered.

Finally, the cutting tool disclosed in US Pat. No. 4,950,108 is designed to couple the cutting head to the body using bolts, but in order to precisely match the center of the body and the cutting head, a cylindrical hole is formed in the body and the cutting head. It is intended to install a separate auxiliary mechanism there is a disadvantage that takes many parts. In addition, the auxiliary mechanism used to match the center of the cutting head with the main body should be enough to withstand the torque generated during the rotation of the cutting head, but it is not easy to obtain an auxiliary mechanism that can satisfy these conditions. have.

The present invention has been made to solve the conventional problems as described above, it is possible to use the replacement of the cutting head, the center of the exact coincidence when coupling the cutting head to the main body, and firmly fixed the cutting head to the main body It is an object of the present invention to provide a cutting head replaceable cutting tool.

Another object of the present invention is to provide a cutting head replaceable cutting tool capable of maintaining the strength of the cutting head by allowing the cooling oil to be sufficiently discharged without forming a separate cooling oil discharge hole for discharging the cooling oil in the cutting head. .

1 is a perspective view of a cutting head replaceable cutting tool according to an embodiment of the present invention.

Figure 2 is an exploded perspective view of the cutting head replaceable cutting tool according to an embodiment of the present invention.

3 is a plan view of a cutting head replaceable cutting tool according to an embodiment of the present invention.

4 is a partial perspective view of the main body shown in FIGS.

5 is a plan view of the main body shown in FIG.

Figure 6 is a cross-sectional view showing the internal structure of the front end of the extension shown in FIG.

7 is a perspective view of the cutting head shown in FIGS.

8 is a plan view of the cutting head shown in FIG.

9 is a bottom view of the cutting head shown in FIG. 7.

10 is a perspective view of the bolt shown in FIGS. 1-3.

<Explanation of symbols for the main parts of the drawings>

1: cutting tool 10: main body

11: head portion 12: extension portion

13, 23: chip discharge groove 14: engaging projection

15 coolant pipe 20 cutting head

21, 22: cutting edge 24: coupling groove

25, 25 ′: Through hole 30: Bolt

31: head 31a: tightening groove

32: screw portion 32a: cooling oil discharge hole

In order to achieve the object as described above, the cutting head replaceable cutting tool of the present invention has a coupling oil protruding from a front end thereof, and a cooling oil conduit in which cooling oil flows inwardly communicates to cool the heat generated during cutting. A main body is formed over the front end from the outer peripheral surface, the chip discharge groove is discharged during the cutting process; A rear end surface is provided with a coupling groove into which a coupling protrusion of the main body is inserted, and a cutting edge for processing a hole is formed in the front end surface, and a cutting head having a chip discharge groove connected to a chip discharge groove of the main body on an outer circumferential surface thereof; And a fastening member fastened to the main body through the cutting head to fix the cutting head to the main body, and having a cooling oil discharge hole formed therein in communication with the cooling oil pipe of the main body to discharge the cooling oil to the cutting portion.

In such a configuration, the coupling protrusion is formed in the cross shape, it is preferable that the coupling groove is also formed in the cross shape corresponding to the coupling protrusion.

Coupling protrusion having a cross-shaped structure, the center protrusion protruding from the center of the front end surface of the main body and the center of the main body and the cutting head coincide with each other; And a pair of auxiliary protrusions which protrude perpendicularly to both sides of the central protrusion so that the left and right sides of the main body and the cutting head coincide with each other.

In addition, in the above configuration, the fastening member is preferably screwed to the outlet side of the cooling oil pipe.

The outlet side of the cooling oil pipe line is branched into at least two pipe lines, and the outlet of each branched pipe line is preferably formed on the coupling protrusion.

Hereinafter, the features and the operation of the above-described configuration through the preferred embodiment of the cutting head replaceable cutting tool according to the present invention will be described in detail.

1 is a perspective view of a cutting head replaceable cutting tool according to an embodiment of the present invention, Figure 2 is an exploded perspective view of a cutting head replaceable cutting tool according to an embodiment of the present invention, Figure 3 is 4 is a plan view of a cutting head replaceable cutting tool according to an embodiment of the present invention, FIG. 4 is a partial perspective view of the main body shown in FIGS. 1 to 3, FIG. 5 is a plan view of the main body shown in FIG. 4, and FIG. 6. 4 is a cross-sectional view showing the internal structure of the front end of the extension shown in Figure 4, Figure 7 is a perspective view of the cutting head shown in Figures 1 to 3, Figure 8 is a plan view of the cutting head shown in Figure 7, Figure 9 7 is a bottom view of the cutting head shown in FIG. 7, and FIG. 10 is a perspective view of the bolt shown in FIGS.

As shown in FIGS. 1 to 3, the cutting head replaceable cutting tool 1 according to the exemplary embodiment of the present invention is detachably coupled to the main body 10 and the main body 10 to drill holes in the workpiece. It comprises a cutting head 20, and a bolt 30 for fixing the cutting head 20 to the main body 10.

As shown in FIGS. 4 to 6, the above-described main body 10 is formed in the head portion 11 for mounting to a drilling machine, an electric drill, or the like, and extends in the head portion 11 to be inserted into a hole during drilling. Two sets of chip discharge grooves 13 for discharging the cutting chips generated from the cutting portion to the outside are composed of an extension part 12 formed on the outer circumferential surface thereof.

At this time, the front end surface of the extension portion 12, that is, the front end surface of the main body 10 is formed with a cross-shaped engaging projection 14 for coupling with the cutting head 20. The engaging projection 14 protrudes from the center of the front end face of the main body 10 so that the centers of the main body 10 and the cutting head 20 coincide with each other, and both sides of the center protruding portion 14a. It is composed of a pair of auxiliary protrusions (14b, 14c) to protrude perpendicularly to the main body 10 and the left and right of the cutting head 20 to match each other. Each side of the coupling protrusion 14 is formed in a vertical plane.

In addition, a cooling oil conduit 15 through which a cooling oil for cooling heat generated at a cutting portion is introduced into the main body 10, and the cooling oil conduit 15 is sheared from the rear end of the main body 10. Formed over. The outlet side of the cooling oil conduit 15 is branched into two conduits 15a and 15b, and the outlet of each branch conduit 15a and 15b is formed on each of the auxiliary protrusions 14b and 14c. Inside the branch conduits 15a and 15b, female threaded portions 15c and 15d are formed in which the threaded portions 32 of the bolt 30 are screwed together.

On the other hand, the chip discharge groove 13 is preferably formed in a spiral as shown in the drawing, but in some cases may be formed in a straight line.

As shown in FIGS. 7 to 9, the above-described cutting head 20 is a portion for directly processing holes, and cutting edges 21 and 22 for cutting holes are formed on both front surfaces thereof, and outer peripheral surfaces thereof. Two sets of chip discharge grooves 23 are connected to the chip discharge grooves 13 of the main body 10 to transfer the cutting chips to the chip discharge grooves 13 of the main body 10. The coupling groove 24 into which the coupling protrusion 14 formed at the front end surface of the bottom surface is inserted into a cross shape to correspond to the coupling protrusion 14, and through holes through which the threaded portion 32 of the bolt 30 passes. 25) 25 'are formed respectively.

At this time, the chip discharge groove 23 is preferably formed in a spiral like the chip discharge groove 13 of the main body 10 may be formed in a straight line in some cases.

The outlet side of the through holes 25 and 25 'is formed in the coupling groove 24, and the head 31 of the bolt 30 to be described later is seated on the inlet side of the through holes 25 and 25'. The seating surfaces 25a and 25a 'are formed.

On the other hand, the inner wall of the coupling groove 24 forms a vertical surface to correspond to the side of the coupling protrusion (14).

As shown in FIG. 10, the above-described bolt 30 is for firmly fixing the cutting head 20 to the main body 10, and hexagonal tightening grooves 31a are formed therein so that the hexagonal wrench can be inserted and tightened. The outlet 31 of the cooling oil conduit 15 of the main body 10 extending through the formed head 31 and the head 31 and penetrating through the through holes 25 and 25 'of the cutting head 20, It consists of the screw part 32 screwed to the exit side of branch line 15a, 15b.

At this time, the cooling oil for discharging the cooling oil flowing from the cooling oil conduit 15 to the cutting site by communicating the cooling oil conduit 15 and the fastening groove 31a of the head 31 in the screw portion 32. The discharge hole 32a is formed.

Referring to the operation of the cutting head replaceable cutting tool according to an embodiment of the present invention configured as described above are as follows.

First, the fitting protrusion 14 of the main body 10 is fitted into the coupling groove 24 of the cutting head 20, and then the bolt 30 is inserted into the through holes 25 and 25 ′ of the cutting head 20. By inserting each and tightening the bolt 30 using a hexagon wrench, the cutting head 20 is firmly fixed to the main body 10.

The main body by the cross-shaped engaging projection 14 formed on the front end surface of the main body 10 in the process of fixing the cutting head 20 to the main body 10 and the engaging groove formed on the rear end surface of the cutting head 20 correspondingly. The centers of the 10 and the cutting head 20 coincide exactly, and the cutting head 20 is firmly fixed to the main body 10.

As such, when the cutting tool of the present invention, in which the coupling of the main body 10 and the cutting head 20 is completed, is cut into a drilling machine or an electric drill, and a hole is punched in the workpiece, the cutting chip generated at the cutting portion is cut into the cutting head 20 and the main body. It is discharged to the outside through the chip discharge groove 13, 23 formed in the (10).

In addition, since the heat generated during the cutting process is cooled by the cooling oil discharged through the cooling oil pipe line 15 of the main body 10 and the cooling oil discharge hole 32a of the bolt 30, the cutting head 20 due to the cutting heat. ) Can be prevented from falling.

On the other hand, since the conduit for discharging the coolant to the cutting portion is formed in the bolt 30, since the separate conduit for discharging the coolant does not have to be formed in the cutting head 20, the strength of the cutting head 20 is increased. maintain.

As described above with reference to the accompanying drawings, the cutting head replaceable cutting tool according to a preferred embodiment of the present invention, the present invention is not limited to the embodiments and drawings described in detail herein, the technical scope of the invention Various modifications can be made within.

According to the present invention, the cutting head replaceable cutting tool as described in detail above, by forming a cross-shaped coupling protrusion on the front end surface of the main body and the cross-shaped coupling groove corresponding to the coupling protrusion of the main body on the rear end surface of the cutting head, The center of the cutting head and the main body can be exactly matched, and the cutting head can be firmly fixed to the main body.

In addition, according to the present invention by forming a conduit for discharging the cooling oil to the cutting portion in the bolt instead of separately formed on the cutting head, there is an advantage that can maintain the strength of the cutting head.

Claims (6)

On the front surface, the engaging projection protrudes, and inside the cooling oil pipe through which the coolant for cooling the heat generated during the cutting process flows in and out from the rear end, the outer peripheral surface is formed with a chip discharge groove discharged during the cutting process main body; A cutting head having a coupling groove into which a coupling protrusion of the main body is inserted at a rear end thereof, a cutting edge for processing a hole at a front end thereof, and a cutting head having a chip discharge groove connected to a chip discharge groove of the main body at an outer circumferential surface thereof; And The fastening member is fastened to the main body through the cutting head to fix the cutting head to the main body, and includes a fastening member having a cooling oil discharge hole formed therein in communication with the cooling oil pipe of the main body to discharge the cooling oil to the cutting portion. Cutting head replaceable cutting tool, characterized in that made. The method of claim 1, The engaging projection is formed in the cross shape, the cutting groove replacement cutting tool, characterized in that the coupling groove is also formed in the cross shape corresponding to the engaging projection. The method of claim 2, The coupling protrusion, A center protrusion protruding from the center of the front end face of the main body so that the centers of the main body and the cutting head coincide with each other; And And a pair of auxiliary protrusions protruding perpendicularly to both sides of the center protrusion so that the left and right sides of the main body and the cutting head coincide with each other. The method of claim 1, The fastening member is a cutting head replaceable cutting tool, characterized in that screwed to the outlet side of the cooling oil pipe. The method according to any one of claims 1 to 4, And the outlet side of the cooling oil pipe line is divided into at least two pipe lines. The method of claim 5, wherein The cutting head replacement cutting tool, characterized in that the outlet of the cooling oil pipe is formed on the engaging projection.