WO2005037473A1

WO2005037473A1 - Insert drill with chamfering function

Info

Publication number: WO2005037473A1
Application number: PCT/KR2003/002879
Authority: WO
Inventors: Jeong-Soo Lee
Original assignee: Yestool Co., Ltd.
Priority date: 2003-10-15
Filing date: 2003-12-30
Publication date: 2005-04-28
Also published as: AU2003288766A1

Abstract

An insert drill with a chamfering function in which a chamfering insert (20) is inserted into and projected from a mounting hole (11) of a drill body (10) by a tension of a torsion spring (30). The insert drill includes the drill body (10) having the mounting hole (11) and first and second bolt holes (13) and (15), the chamfering insert (20) inserted into the mounting hole (11), and having a coupling groove (21), a first bolt (40) tightened into the first bolt hole (13), a second bolt (60) tightened into the second bolt hole (15), a push rod (50) coupled to an inside end of the second bolt (60), with a coupling hole (51) formed on the push rod (50), and the torsion spring (30) provided in the inner space of the drill body (10). The torsion spring (30) has a first spring arm (31) coupled to the chamfering insert (20), a coiled part (32) engaging with an outer surface of the first bolt (40), and a second spring arm (33) coupled to the push rod (50).

Description

INSERT DRILL WITH CHAMFERING FUNCTION

Technical Field

The present invention relates, in general, to insert drills with chamfering functions and, more particularly, to an insert drill with a chamfering function in which a chamfering insert capable of removing burrs is inserted into a mounting hole of a drill body, and a torsion spring is installed in the drill body so as to adjust a movement of the chamfering insert.

Background Art

An insert drill with a chamfering function was proposed in Korean Patent Laid-Open Publication NO. 2003-0015022 ( Filed : February. 20, 2003 ), entitled

'CHAMFERING TOOL'. The above-mentioned conventional insert drill includes a body, a blade and a support pin. The body has a mounting hole at a lower portion thereof, and a center hole formed on an upper end to extend to the mounting hole. The blade has an inclined groove on an upper surface thereof. The blade is inserted into the mounting hole of the body and is supported by the support pin which is inserted into the center hole of the body. At this time, the pin vertically moves along the inclined groove of the blade while an end of the pin is in contact with the inclined groove of the blade, so that the blade horizontally slides in the mounting hole of the body. However, in the conventional insert drill, if impurities, such as workpiece chips and etc., are caught in the inclined groove of the blade during a drilling operation, a positional change of the blade may be undesirably caused, thus generating an operational error of the insert drill. In addition, the conventional insert drill is problematic in that the movement of the blade is not smooth enough because the pin moves along the inclined groove of the blade while the end of the pin is in contact with the inclined groove of the blade.

Disclosure of the Invention

Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide an insert drill with a chamfering function in which a chamfering insert is inserted into and projected from a mounting hole of a drill body by a tension of a torsion spring, so that a horizontal movement of the chamfering insert is smooth enough, and an operational error caused by impurities, such as workpiece chips and etc., is reduced. The above and/or other aspects are achieved by providing an insert drill with a chamfering function, including a drill body having: a mounting hole formed on a lower portion of the drill body, and first and second bolt holes respectively formed on predetermined portions of an outer surface of the drill body so as to extend to an inner space defined in the drill body; a chamfering insert inserted into the mounting hole of the drill body, with a coupling groove formed on an upper surface of the chamfering insert; a first bolt tightened into the first bolt hole of the drill body; a second bolt tightened into the second bolt hole of the drill body; a push rod coupled to an inside end of the second bolt such that the second bolt rotates relative to the push rod, with a coupling hole formed on the push rod; and a torsion spring provided in the inner space of the drill body. The torsion spring has a first spring arm coupled to the chamfering insert, with an end of the first spring arm inserted into the coupling groove of the chamfering insert, a coiled part engaging with an outer surface of the first bolt, and a second spring arm coupled to the push rod, with an end of the second spring arm inserted into the coupling hole of the push rod. The above and/or other aspects are also achieved by providing an insert drill with a chamfering function, including a drill body having: a mounting hole formed on a predetermined portion of an outer surface of the drill body, and first and second bolt holes respectively formed on predetermined portions of the outer surface of the drill body so as to extend to an inner space defined in the drill body; a chamfering insert inserted into the mounting hole of the drill body, with a coupling groove formed on an upper surface of the chamfering insert; a first bolt tightened into the first bolt hole of the drill body; a second bolt tightened into the second bolt hole of the drill body; a push rod coupled to an inside end of the second bolt, so that the second bolt rotates relative to the push rod, with a coupling hole formed on the push rod; a torsion spring provided in the inner space of the drill body. The torsion spring has a first spring arm coupled to the chamfering insert, with an end of the first spring arm inserted into the coupling groove of the chamfering insert, a coiled part engaging with an outer surface of the first bolt, and a second spring arm coupled to the push rod, with an end of the second spring arm inserted into the coupling hole of the push rod. The insert drill further includes an insert support unit inserted into the mounting hole of the drill body along with the chamfering insert such that the insert support unit is closely placed under the chamfering insert.

Brief Description of the Drawings

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: FIG. 1 is a side sectional view of an insert drill with a chamfering function, according to a first embodiment of the present invention; FIG. 2 is a front sectional view of the insert drill of FIG. 1; FIG. 3 is a side sectional view of the insert drill of FIG. 1 , in which a tension of a torsion spring increases by tightening a second bolt of which an inside end is coupled to a push road coupled to a second spring arm of the torsion spring; FIGS. 4A to 4C are views showing an operational state of the insert drill of FIG. 1, wherein: FIG. 4A is a sectional view of the insert drill of FIG. 1, in which a front blade of a chamfering insert chamfers an upper edge of a drilled hole of a workpiece; FIG. 4B is a sectional view of the insert drill of FIG. 1, in which the chamfering insert does not chamfer any edges of the drilled hole of the workpiece while the chamfering insert passes through the drilled hole of the workpiece; and FIG. 4C is a sectional view of the insert drill of FIG. 1, in which a rear blade of the chamfering insert chamfers a lower edge of the drilled hole of the workpiece after passing through the drilled hole of the workpiece; FIG. 5 is a front sectional view of an insert drill with a chamfering function, according to a second embodiment of the present invention; FIG. 6 is a side sectional view of the insert drill of FIG. 5; FIG. 7 is a front sectional view of an insert drill with a chamfering function, according to a third embodiment of the present invention; and FIG. 8 is a side sectional view of the insert drill of FIG. 7.

Best Mode for Carrying Out the Invention 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. FIG. 1 is a side sectional view of an insert drill with a chamfering function, according to a first embodiment of the present invention. FIG. 2 is a front sectional view the insert drill of FIG. 1. FIG. 3 is a side sectional view of the insert drill of FIG. 1, in which a tension of a torsion spring 30 increases by tightening a second bolt 60 of which an inside end is coupled to a push road 50 coupled to a second spring arm 33 of the torsion spring 30. As shown in FIGS. 1 and 2, the insert drill according to the first embodiment of the present invention includes a drill body 10. The drill body 10 has a mounting hole 1 1 which is formed on a lower portion of the drill body 10, and first and second bolt holes 13 and 15 which are respectively formed on predetermined portions of an outer surface of the drill body 10 so as to extend to an inner space defined in the drill body 10. The insert drill further includes a chamfering insert 20 which is inserted into the mounting hole 11 of the drill body 10, with a coupling groove 21 formed on an upper surface of the chamfering insert 20. The insert drill further includes a first bolt 40 which is tightened into the first bolt hole 13 of the drill body 10, and a second bolt 60 which is tightened into the second bolt hole 15 of the drill body 10. The insert drill further includes the push rod 50 which is coupled to the inside end of the second bolt 60 such that the second bolt 60 rotates relative to the push rod 50, with a coupling hole 51 formed on the push rod 50, and the torsion spring 30 which is provided in the inner space of the drill body 10. The torsion spring 30 has a first spring arm 31 which is coupled to the chamfering insert 20, with an end of the first spring arm 31 inserted into the coupling groove 21 of the chamfering insert 20. The torsion spring 30 further has a coiled part 32 engaging with an outer surface of the first bolt 40, and the second spring arm 33 which is coupled to the push rod 50, with an end of the second spring arm 33 inserted into the coupling hole 51 of the push rod 50. The shape and construction of the above-mentioned drill body 10 may be referred to Korean Utility Model Registration NO. 171645 ( Filed: December. 7. 1999 ). Therefore, the further explanation of the shape and construction of the drill body 10 is not deeded necessary herein. The first and second bolt holes 13 and 15 are respectively formed on the predetermined portions of the outer surface of the drill body 10 such that central axes of the first and second bolt holes 13 and 15 are offset from each other, with an angle of 90 degree formed between the offset central axes of the first and second bolt holes 13 and 15. The chamfering insert 20 is arranged in the mounting hole 11 of the drill body 10 such that a front blade 23 and a rear blade 25, which are respectively formed on an end of the chamfering insert 20, are projected from the mounting hole 11. The coupling groove 21 is formed on the upper surface of the chamfering insert 20, so that the end of the first spring arm 31 of the torsion spring 30 is inserted into the coupling groove 21. The torsion spring 30 is placed in the inner space of the drill body 10 such that a vertical central axis Y' of the coiled part 32 of the torsion spring 30 is offset from a rotating axis Y of the drill body 10. That is, the vertical central axis Y' of the coiled part 32 is spaced apart from the rotating axis Y of the drill body 10 at a predetermined interval d along a horizontal central axis X ( see, FIG. 1 ) of the coiled part 32. The first and second spring arms 31 and 33 of the torsion spring 30 respectively extend from the coiled part 32 of the torsion spring 30 in opposite directions. The second bolt 60 has at the inside end thereof a mounting groove 61, and the push rod 50 is coupled to the mounting groove 61 of the second bolt 60, as shown in FIG. 1. Furthermore, the coupling hole 51 is formed on the push rod 50 so as to couple the second spring arm 33 of the torsion spring 30 to the push rod 50. Therefore, even when the second bolt 60 rotates relative to the push rod 50 in the second bolt hole 15 of the drill body 10, the push rod 50 is not rotated. A tension of the torsion spring 30 is adjusted in response to a position of the push rod 50 coupled to the inside end of the second bolt 60 while the second bolt 60 is tightened into or loosened from the second bolt hole 15 of the drill body 10, so that the tension of the torsion spring 30 adjusts a resistance of the chamfering insert 20 which resists a force driving the chamfering insert 20 into the mounting hole 11 of the drill body 10 during a chamfering operation. That is, when the second bolt 60 moves in the mounting hole 15 of the drill body 10 in a direction shown by the arrow 81 in FIG. 3 from a position shown by the dotted line in FIG. 3, the push rod 50 moves in the inner space of the drill body 10 in a direction shown by the arrow 81 FIG. 3, so that the tension of the torsion spring 30 increases, thus increasing the resistance of the chamfering insert 20 which resists the force driving the chamfering insert 20 into the mounting hole 11 of the drill body 10 in a direction shown by the arrow 82 FIG. 3. Next, the operation of the insert drill of the present invention will be described herein below with reference to FIGS. 4 A to 4C. FIGS. 4A to 4C are views showing an operational state of the insert drill of FIG. 1. As shown in FIG. 4A, the front blade 23 of the chamfering insert 20 chamfers an upper edge 91 of a drilled hole 92 of a workpiece 90. Thereafter, the chamfering insert 20 is inserted into the mounting hole 11 of the drill body 10, so that the chamfering insert 20 does not interfere with the drilled hole 92 of the workpiece 90 when the lower portion of the drill body 10 passes through the drilled hole 92. At this time, a lower end of the first spring arm 31 of the torsion spring 30 moves in the direction shown by the arrow 82 of FIG. 4B, so that the torsion spring 30 has a restoring force while the chamfering insert 20 is inserted into the mounting hole 11 of the drill body 10. Thereafter, as shown in FIG. 4C, the chamfering insert 20 is projected from the mounting hole 11 of the drill body 10 by the restoring force of the torsion spring 30 after the lower portion of the drill body 10 passed through the drilled hole 92 of the workpiece 90. At this time, a lower edge 93 of the drilled hole 92 of the workpiece 90 can be chamfered by the rear blade 25 of the chamfering insert 20. FIG. 5 is a front sectional view of an insert drill with a chamfering function, according to a second embodiment of the present invention. FIG. 6 is a side sectional view of the insert drill of FIG. 5. As shown in FIGS. 5 and 6, the insert drill according to the second embodiment of the present invention includes the drill body 10. The drill body

10 has the mounting hole 11 which is formed on the lower portion of the drill body 10, and the first and second bolt holes 13 and 15 which are respectively formed on predetermined portions of the outer surface of the drill body 10 so as to extend to the inner space defined in the drill body 10. The insert drill further includes the chamfering insert 20 which is inserted into the mounting hole 11 of the drill body 10, with the coupling groove 21 formed on the upper surface of the chamfering insert 20. The insert drill further includes the first bolt 40 which is tightened into the first bolt hole 13 of the drill body 10, and the second bolt 60 which is tightened into the second bolt hole 15 of the drill body 10. The insert drill further includes the push rod 50 which is coupled to the inside end of the second bolt 60 such that the second bolt 60 rotates relative to the push rod 50, with the coupling hole 51 formed on the push rod 50, and the torsion spring 30 which is provided in the inner space of the drill body 10. The torsion spring 30 has the first spring arm 31 which is coupled to the chamfering insert 20, with the end of the first spring arm 31 inserted into the coupling groove 21 of the chamfering insert 20. The torsion spring 30 further has the coiled part 32 engaging with the outer surface of the first bolt 40, and the second spring arm 33 which is coupled to the push rod 50, with the end of the second spring arm 33 inserted into the coupling hole 51 of the push rod 50. The insert drill further includes an insert support unit 100 which is inserted into the mounting hole 11 of the drill body 10 along with the chamfering insert 20 such that the insert support unit 100 is closely placed under the chamfering insert 20. The insert support unit 100 has a right hexahedral shape. The insert drill further includes a third bolt hole 17 ( see, FIG. 6 ) which is formed on a predetermined portion of the outer surface of the drill body 10, and a third bolt 1 10 which is tightened into the third bolt hole 17 of the drill body 10, with an inside end of the third bolt 110 compressing the insert support unit 100 which is placed in the mounting hole 11 of the drill body 10, thus the third bolt 110 holds the insert support unit 100 in the mounting hole 11 of the drill body 10. In the insert drill of the second embodiment of the present invention having the above-mentioned construction, in case that a user desires to change the chamfering insert 20 with a new one, due to wear of the front and rear blades 23 and 25 of the chamfering insert 20, the user loosens the third bolt 110 from the third bolt hole 17 of the drill body 10, so as to remove the insert support unit 100 from the mounting hole 11 of the drill body 10. When the insert support unit 100 is removed from the mounting hole 11 of the drill body 10 as described above, the user can remove the chamfering insert 20 from the first spring arm 31 of the torsion spring 30 through a remaining space in the mounting hole 11 of the drill body 10, thus removing the chamfering insert 20 from the mounting hole 11 of the drill body

10. Thereafter, the user inserts a new chamfering insert 20 and the insert support unit 100 into the mounting hole 11 of the drill body 10 in a reverse order to the above-mentioned chamfering insert removing operation. FIG. 7 is a front sectional view of an insert drill with a chamfering function, according to a third embodiment of the present invention. FIG. 8 is a side sectional view of the insert drill of FIG. 7. As shown in FIGS. 7 and 8, the insert drill of the third embodiment of the present invention includes a tap hole 101 which is formed on a central portion of a lower surface of the insert support unit 100, a drilling insert hole 130 which is formed on a lower end of the drill body 10, and a drilling insert 120 which is inserted into the drilling insert hole 130. The insert drill of the third embodiment further includes a fourth bolt hole 19 extending from the drilling insert hole 130 to the mounting hole 11 of the drill body 11, and a fourth bolt 140 which is tightened into the fourth bolt hole 19 and has a bolt head 141 at an outside end thereof, with an inside end of the fourth bolt 140 being inserted into the tap hole 101 of the insert support unit 100. The general construction of the insert drill according to the third embodiment except for the above-mentioned elements remains the same as the second embodiment, and further explanation is thus not deeded necessary. In the insert drill of the third embodiment of the present invention having the above-mentioned construction, in case that a user desires to change the chamfering insert 20 with a new one, due to wear of the front and rear blades 23 and 25 of the chamfering insert 20, the user removes the drilling insert 120 from the drilling insert hole 130 of the drill body 10. Thereafter, the user loosens the fourth bolt 140 from the fourth bolt hole 19 of the drill body 10 such that the inside end of the fourth bolt 140 is removed from the tap hole 101. The user, thereafter, removes the insert support unit 100 and the chamfering insert 20 from the mounting hole 11 of the drill body 10. Thereafter, the user inserts the fourth bolt 140 into the fourth bolt hole 19 after inserting a new chamfering insert 20 and the insert support unit 100 into the mounting hole 11 of the drill body 10, in a reverse order to the above-mentioned chamfering insert removing operation. At this time, the bolt head 141 of the fourth bolt 140 is supported around a lower edge of the fourth bolt hole 19 while the outer thread 142 of the fourth bolt 140 engages with the inner thread of the fourth bolt hole 19, such that the inside end of the fourth bolt 140 is inserted into the tap hole 101 of the insert support unit 100. Therefore, the fourth bolt 140 pulls the insert support unit 100 toward a lower surface of the mounting hole 11, so that the insert support unit 100 is in close contact with the lower surface of the mounting hole 11 of the drill body 10.

Industrial Applicability

As described above, the present invention provides an insert drill with a chamfering function in which a chamfering insert is inserted into and projected from a mounting hole of a drill body by a tension of a torsion spring, so that a horizontal movement of the chamfering insert is smooth enough, and an operational error caused by impurities, such as workpiece chips and etc., is reduced. Although the preferred embodiments of the present invention have 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 with a chamfering function, comprising: a drill body comprising: a mounting hole formed on a lower portion of the drill body; and first and second bolt holes respectively formed on predetermined portions of an outer surface of the drill body so as to extend to an inner space defined in the drill body; a chamfering insert inserted into the mounting hole of the drill body, with a coupling groove formed on an upper surface of the chamfering insert; a first bolt tightened into the first bolt hole of the drill body; a second bolt tightened into the second bolt hole of the drill body; a push rod coupled to an inside end of the second bolt such that the second bolt rotates relative to the push rod, with a coupling hole formed on the push rod; and a torsion spring provided in the inner space of the drill body, the torsion spring comprising: a first spring arm coupled to the chamfering insert, with an end of the first spring arm inserted into the coupling groove of the chamfering insert; a coiled part engaging with an outer surface of the first bolt; and a second spring arm coupled to the push rod, with an end of the second spring arm inserted into the coupling hole of the push rod;

2. The insert drill according to claim 1, wherein the first and second bolt holes are respectively formed on the predetermined portions of the outer surface of the drill body such that central axes of the first and second bolt holes are offset from each other, with an angle of 90 degree formed between the offset central axes of the first and second bolt holes.

3. The insert drill according to claim 1, wherein the torsion spring is placed in the inner space of the drill body such that a vertical central axis of the coiled part of the torsion spring is offset from a rotating axis of the drill body.

4. The insert drill according to claim 1, wherein a tension of the torsion spring is adjusted in response to a position of the push rod coupled to the inside end of the second bolt while the second bolt is tightened into or loosened from the second bolt hole of the drill body, so that the tension of the torsion spring adjusts a resistance of the chamfering insert which resists a force driving the chamfering insert into the mounting hole of the drill body during a chamfering operation.

5. An insert drill with a chamfering function, comprising: a drill body comprising: a mounting hole formed on a predetermined portion of an outer surface of the drill body; and first and second bolt holes respectively formed on predetermined portions of the outer surface of the drill body so as to extend to an inner space defined in the drill body; a chamfering insert inserted into the mounting hole of the drill body, with a coupling groove formed on an upper surface of the chamfering insert; a first bolt tightened into the first bolt hole of the drill body; a second bolt tightened into the second bolt hole of the drill body; a push rod coupled to an inside end of the second bolt, so that the second bolt rotates relative to the push rod, with a coupling hole formed on the push rod; a torsion spring provided in the inner space of the drill body, the torsion spring comprising: a first spring arm coupled to the chamfering insert, with an end of the first spring arm inserted into the coupling groove of the chamfering insert; a coiled part engaging with an outer surface of the first bolt; and a second spring arm coupled to the push rod, with an end of the second spring arm inserted into the coupling hole of the push rod; and an insert support unit inserted into the mounting hole of the drill body along with the chamfering insert such that the insert support unit is closely placed under the chamfering insert.

6. The insert drill according to claim 5, further comprising: a third bolt hole formed on a predetermined portion of the outer surface of the drill body; and a third bolt tightened into the third bolt hole of the drill body, with an inside end of the third bolt compressing the insert support unit which has a right hexahedral shape and is placed in the mounting hole of the drill body, thus the third bolt holding the insert support unit in the mounting hole of the drill body.

7. The insert drill according to claim 5, further comprising: a tap hole formed on a central portion of a lower surface of the insert support unit; a drilling insert hole formed on a lower end of the drill body; a drilling insert inserted into the drilling insert hole; a fourth bolt hole extending from the drilling insert hole to the mounting hole of the drill body; and a fourth bolt tightened into the fourth bolt hole and having a bolt head at an outside end thereof, with an inside end of the fourth bolt being inserted into the tap hole of the insert support unit.