WO2005102573A1

WO2005102573A1 - Insert drill

Info

Publication number: WO2005102573A1
Application number: PCT/KR2004/001585
Authority: WO
Inventors: Jeong-Soo Lee
Original assignee: Yestool Co., Ltd.
Priority date: 2004-04-23
Filing date: 2004-06-29
Publication date: 2005-11-03
Also published as: KR100612908B1; KR20050102987A

Abstract

The present invention provides an insert drill in which an insert (70) is removably inserted into a head part (61) of a drill body (50). The insert drill includes the drill body (50), the insert (70) to be inserted into a mounting slot (51) of the drill body (50), and a first bolt (81) to be tightened into a first coupling hole (55) of the drill body (50). The insert drill further includes first and second cutting oil discharging holes (57) and (59) of the head part (61) of the drill body (50), and a second coupling hole (63) extending from the first cutting oil discharging hole (57) toward the second cutting oil discharging hole (59). The insert drill further includes an insert fastening hole (77) provided in the insert (70), and a second bolt (83) to be tightened into the second coupling hole (63) of the drill body (50) to pass through the insert fastening hole (77) of the insert (70) while the insert (70) is inserted in the mounting slot (51) of the drill body (50).

Description

Description INSERT DRILL Technical Field

[1] The present invention relates, in general, to insert drills in which inserts are removably inserted into head parts of drill bodies and, more particularly, to an insert drill in which a coupling bolt is tightened into the head part of the drill body to fasten a tip part of an insert in the drill body without interfering with a flow of a cutting oil. Background Art

[2] An endmill was proposed in Korean Utility Registration NO. 237150 (Filed: June, 26, 2001), entitled ENDMILL WITH DRILLING FUNCTION.

[3] The conventional endmill with a drilling function includes a drill body and a cutting tool unit which is removably inserted into the drill body. The drill body includes a spiral flute which extends from a predetermined portion of the drill body to a head part of the drill body, and a mounting slot which is provided in the head part of the drill body. A shank hole having a predetermined depth is provided on the mounting slot of the drill body. The drill body further includes a first coupling hole which extends from on an outer surface of the drill body to the mounting slot, and a second coupling hole which is provided under the first coupling hole and extends from the outer surface of the drill body to the shank hole. The cutting tool unit includes a cutting tool and a chip guide groove which extends downward from an outer surface of the cutting tool to guide exhaust of chips cut by the cutting tool. The cutting tool unit further includes at a lower portion thereof a shank part to correspond to the shank hole of the mounting slot. An inclined groove is provided on the shank part to engage with an end of a first screw which is inserted into the second coupling hole of the drill body. A through hole is provided on a predetermined portion of an outer surface of the cutting tool unit to receive thereinto a second screw which is tightened into the first coupling hole.

[4] As such, the conventional endmill has no path and no discharging hole discharging cutting oil to the outside. Therefore, it is possible to fasten a tip part of the cutting tool unit in the drill body by tightening the second screw into both the first coupling hole and the through hole which are respectively provided in the head part of the drill body and a tip part of the cutting tool unit to be aligned with each other. E wever, in case of insert drills with cutting oil paths and cutting oil discharging holes, it is very difficult to fasten tip parts of inserts in drill bodies using bolts without interfering with the cutting oil paths and the cutting oil discharging holes. [5] As shown in FIGS. 1 and 2, a conventional insert drill includes cutting oil paths 11 and cutting oil discharging holes 13 which are provided in a drill body 10 to discharge the cutting oil from the drill body 10 to the outside. The drill body 10 has a coupling hole 19 which is provided under a head part 15 of the drill body 10 on a predetermined portion of an outer surface of the drill body 10 except for predetermined portions on which flutes 17 are formed to exhaust chips. At this time, the coupling hole 19 does not interfere with the cutting oil paths 11. To fasten the insert 30 in the drill body 10, a shank part 31, which has a bolt contact surface 33 and is provided on a lower portion of the insert 30, is inserted into a shank hole 23 provided on a mounting slot 21 of the drill body 10. Thereafter, a predetermined bolt 25 is tightened into the coupling hole 19 of the drill body 10 so that an end of the bolt 25 presses against the bolt contact surface 33 of the shank part of the insert 30. Disclosure of Invention Technical Problem

[6] Ebwever, the conventional insert drill is problematic in that an upper end of the shank part 31, at which the shank part 31 is coupled to the tip part 35 of the insert 30, is easily broken due to vibration of the insert drill during use. Technical Solution

[7] Accordingly, the present invention has been made keeping in mind the above- mentioned problems occurring in the prior art, and an object of the present invention is to provide an insert drill in which a coupling bolt is tightened into a head part of a drill body to fasten a tip part of an insert in the drill body without interfering with a flow of a cutting oil, thus preventing a junction of a shank part and the tip part of the insert from being undesirably broken.

[8] In order to accomplish the above object, the present invention provides an insert drill, including: a drill body with both a mounting slot and a first coupling hole; an insert to be inserted into the mounting slot of the drill body; and a first bolt to be tightened into the first coupling hole of the drill body to press against a bolt contact surface provided on a shank part of the insert. The insert drill includes first and second cutting oil discharging holes provided on predetermined portions of a head part of the drill body, respectively; a second coupling hole extending from a sidewall of the first cutting oil discharging hole toward a sidewall of the second cutting oil discharging hole while being formed along an Y-axis of the drill body and being perpendicular to a Z-axis of the drill body; an insert fastening hole provided in a tip part of the insert to be aligned with the second coupling hole of the drill body while the insert is inserted in the mounting slot of the drill body; and a second bolt to be tightened into the second coupling hole of the drill body to pass through the insert fastening hole of the insert while the insert is inserted in the mounting slot of the drill body. Brief Description of the Drawings

[9] The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[10] FIG. 1 is an exploded perspective view of a conventional insert drill;

[11] FIG. 2 is a sectional view of the conventional insert drill of FIG. 1;

[12] FIG. 3 is an exploded perspective view of an insert drill, according to an embodiment of the present invention;

[13] FIG. 4 is a top view of the insert drill of FIG. 3;

[14] FIG. 5 is an exploded sectional view of the insert drill of FIG. 3; and

[15] FIG. 6 is a sectional view of the insert drill of FIG. 3, in which an insert is fastened in a drill body by a second bolt. Best Mode for Carrying Out the Invention

[16] Reference should now be made to the drawings, in which the same reference numerals are used throughout the different drawings to designate the same or similar components.

[17] Referring to FIGS. 3 through 5, an insert drill according to an embodiment of the present invention includes a drill body 50 with both a mounting slot 51 and a first coupling hole 55, and an insert 70 to be inserted into the mounting slot 51 of the drill body 50. The insert drill further includes a first bolt 81 to be tightened into the first coupling hole 55 of the drill body 50 to press against a bolt contact surface 73 which is provided on a shank part 71 of the insert 70.

[18] First and second cutting oil discharging holes 57 and 59 are provided on predetermined portions of a head part 61 of the drill body 50, respectively. The insert drill further includes a second coupling hole 63 extending from a sidewall of the first cutting oil discharging hole 57 toward a sidewall of the second cutting oil discharging hole 59 while being formed along an Y-axis of the drill body 50, as shown in FIG. 4. Thus, the second coupling hole 63 is perpendicular to a Z-axis of the drill body 50, as shown in FIG. 5. The insert drill further includes an insert fastening hole 77 which is provided in a tip part 75 of the insert 70 to be aligned with the second coupling hole 63 of the drill body 50 while the insert 70 is inserted in the mounting slot 51 of the drill body 50. A second bolt 83 is tightened into the second coupling hole 63 of the drill body 50 to pass through the insert fastening hole 77 of the insert 70 while the insert 70 is inserted in the mounting slot 51 of the drill body 50.

[19] As shown in FIG. 6, the insert drill further includes an enlarged part 63a which is provided on a predetermined portion of the second coupling hole 63 around the first cutting oil discharging hole 57 to receive a head part 83a of the second bolt 83 in the enlarged part 63a. Therefore, when the second bolt 83 is tightened into the second coupling hole 63, the head part 83a of the second bolt 83 does not interfere with the first cutting oil discharging hole 57.

[20] At this time, because the head part 61 of the drill body 50 is tapered to an end thereof, the second bolt 83 is tightened into both the drill body 50 and the insert 70 to fasten the insert 70 in the drill body 50. Furthermore, the second coupling hole 63 is provided along the Y-axis of the drill body, as shown in FIGS. 4, 5 and 6. Therefore, as shown in FIG. 3, the insert fastening hole 77 can be provided on a predetermined portion of the tip part 75 of the insert 70 except for a predetermined portion on which a flute 79 is formed.

[21] As such, in the insert drill of the present invention, the tip part 75 of the insert 70 is fastened in the drill body 50 by the second bolt 83. Therefore, even when the insert drill vibrates during a drilling process, the tip part 75 of the insert 70 does not vibrate relative the drill body 50, thus preventing the shank part 71 of the insert 70 from being broken. Industrial Applicability

[22] As described above, the present invention provides an insert drill in which a second coupling bolt directly fastens a tip part of an insert in the drill body without interfering with a flow of a cutting oil, thus preventing a junction of a shank part and the tip part of the insert from being undesirably broken.

[23] Although the preferred embodiment of the present invention has been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

[1] An insert drill, comprising: a drill body with both a mounting slot and a first coupling hole; an insert to be inserted into the mounting slot of the drill body; and a first bolt to be tightened into the first coupling hole of the drill body to press against a bolt contact surface provided on a shank part of the insert, the insert drill comprising: first and second cutting oil discharging holes provided on predetermined portions of a head part of the drill body, respectively; a second coupling hole extending from a sidewall of the first cutting oil discharging hole toward a sidewall of the second cutting oil discharging hole while being formed along an Y-axis of the drill body and being perpendicular to a Z-axis of the drill body; an insert fastening hole provided in a tip part of the insert to be aligned with the second coupling hole of the drill body while the insert is inserted in the mounting slot of the drill body; and a second bolt to be tightened into the second coupling hole of the drill body to pass through the insert fastening hole of the insert while the insert is inserted in the mounting slot of the drill body.

[2] The insert drill according to claim 1, further comprising: an enlarged part provided on a predetermined portion of the second coupling hole around the first cutting oil discharging hole to receive a head part of the second bolt in the enlarged part, so that, when the second bolt is tightened into the second coupling hole, the head part of the second bolt does not interfere with the first cutting oil discharging hole.