WO2003059561A1 - Core drill - Google Patents
Core drill Download PDFInfo
- Publication number
- WO2003059561A1 WO2003059561A1 PCT/KR2003/000041 KR0300041W WO03059561A1 WO 2003059561 A1 WO2003059561 A1 WO 2003059561A1 KR 0300041 W KR0300041 W KR 0300041W WO 03059561 A1 WO03059561 A1 WO 03059561A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- core drill
- rock
- shank
- concrete structures
- diamond
- Prior art date
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B28—WORKING CEMENT, CLAY, OR STONE
- B28D—WORKING STONE OR STONE-LIKE MATERIALS
- B28D1/00—Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor
- B28D1/02—Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor by sawing
- B28D1/04—Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor by sawing with circular or cylindrical saw-blades or saw-discs
- B28D1/041—Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor by sawing with circular or cylindrical saw-blades or saw-discs with cylinder saws, e.g. trepanning; saw cylinders, e.g. having their cutting rim equipped with abrasive particles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23B—TURNING; BORING
- B23B51/00—Tools for drilling machines
- B23B51/06—Drills with lubricating or cooling equipment
Definitions
- the present invention relates generally to a core drill which is used for forming holes in rock or concrete structures or extracting cylindrical samples, so- called cores, from rock or concrete structures, and more particularly, to a core drill which is designed to reduce the contact surface area of its cutting edge with the rock or concrete structures during a drilling process, thus minimizing frictional resistance between the cutting edge of the drill and the rock or concrete structures and thereby maximizing drilling efficiency, and which is designed to prevent the abrasion of the core drill, smoothly discharge chips, and effectively dissipate heat, thus minimizing abrasion of metal bond holding diamond tips, therefore preventing diamond granules from being removed from the diamond tips of the drill, and effectively lengthening its life span.
- core drills are used for forming holes in desired portions of concrete structures or predetermined portions of concrete structures in repair work, and extracting cylindrical samples from rock, concrete structures, or other materials which are difficult to cut, so as to test the rock or concrete structures for strength.
- Such core drills are typically classified into two types, that is, a wet-type core drill and a dry-type core drill, according to the purpose of the core drills and the hardness of a material to be cut.
- the wet-type core drill is designed such that water is injected into the core drill during a drilling process.
- the dry-type core drill performs a drilling process without injecting water into the core drill.
- chips are easily discharged to the outside by water injected into the core drill.
- chips are discharged to the outside without any external assistance, so it is difficult to discharge the chips to the outside.
- Fig. 1 is a view showing a conventional dry-type core drill, when the core drill is used to form a hole in a target material, such as a concrete structure or rock.
- the core drill includes diamond tips 110 welded to the end of a cylindrical shank
- a connecting unit 200 is mounted on the shank 100 so that the core drill is connected to a core drill drive unit (not shown) via the connecting unit 200.
- the core drill is axially assembled with the core drill drive unit through the connecting unit 200. After the core drill is placed on a target material C to be drilled, such as a concrete structure, rock or other materials which are difficult to cut, the core drill is rotated. At this time, the diamond tips 110 are in frictional contact with the material C, thus forming a hole in the material C.
- a target material C to be drilled such as a concrete structure, rock or other materials which are difficult to cut
- the conventional dry-type core drill has a problem in that frictional resistance is increased, because the contact surface area between the diamond tips 110 and the material C is increased as the hole of the material C becomes deeper.
- each of the diamond tips 110 has a rectangular cross-section, so the sectional area of the diamond tips 110 is larger than that of the shank 100.
- drilling efficiency is poor, so slippage may occur.
- a reacting force applied from the material C to the diamond tips 110 during the drilling process is partially dispersed in the shank 100 in radial directions, thus causing a vibration. Due to such a vibration, the granules forming the diamond tips 110 may be removed from the diamond tips 110 or may be deformed, thus reducing drilling efficiency and life span.
- the conventional dry-type core drill has another problem that the shank 100 has a linear external surface and clearance between the shank 100 and each diamond tip 110 is 0.5-0.75mm, so the shank 100 may get caught in the material C and the chips are not smoothly discharged when the hole of the material C becomes deeper, thus undesirably increasing load.
- the diamond tips 110 may be designed to be thicker. However, thicker diamond tips 110 cause a waste of resources, so it is uneconomical. Further, when increasing the thickness of the diamond tips 110, the contact surface area between the edge of the shank 100 and the diamond tips 110 is relatively small, so the diamond tips 110 may be undesirably removed from the shank 100 when the core drill is rotated at a high speed.
- an object of the present invention is to provide a core drill, which is designed to reduce the contact surface area of its cutting edge with rock or concrete structures during a drilling process, thus minimizing frictional resistance between the cutting edge of the drill and the rock or concrete structures and thereby maximizing drilling efficiency and minimizing wear on the core drill.
- Another object of the present invention is to provide a core drill, which is designed to smoothly discharge chips and effectively dissipate heat, thus minimizing abrasion of metal bond holding diamond tips on a shank to prevent granules of diamond tips from being undesirably removed from the tips, therefore lengthening its life span and maximizing operational efficiency.
- the present invention provides a core drill including diamond tips along a lower edge of a cylindrical shank at regular intervals, wherein each of the diamond tips has a sharp edge formed at a lower edge of the diamond tip to have a cross-section of an acute angle, and a notch formed at a predetermined portion of the diamond tip in such a way as to be tapered upwardly from the sharp edge, and the cylindrical shank has an external surface which is tapered upwards.
- Fig. 1 is a view showing a conventional core drill, when the core drill is used to form a hole in a target material;
- Fig. 2 is a diagram showing a reacting force applied from the target material to diamond tips, when the conventional core drill forms a hole in the target material;
- Fig. 3 is a bottom perspective view showing diamond tips included in a core drill according to the present invention. . ... .
- Fig. 4 is a sectional view of the core drill according to the present invention.
- Fig. 5 is a sectional view of one of the diamond tips included in the core drill according to the present invention
- Fig. 6 is diagram showing a reacting force applied from a target material to the diamond tips, when the core drill of the present invention forms a hole in the target material
- Fig. 7 is a sectional view of the core drill according to the present invention, when the core drill is used to form a hole in the target material.
- a core drill according to the present invention includes a cylindrical shank 10. Diamond tips 11 are mounted along the lower edge of the shank 10 at regular intervals through a welding method.
- Each diamond tip 11 is cut to have an acute angle ⁇ at its lower edge, thus forming a sharp edge 12. Further, each diamond tip 11 has a notch 13 which is tapered upwardly from the sharp edge 12.
- the shank 10 has a tapered external surface 14, which is tapered upwards.
- each diamond tip 11 is provided with the sharp edge 12 having a cross-section of an acute-angled triangle so as to minimize a contact surface area of its cutting edge with a target material C, such as rock or concrete structures, during a drilling process, thus minimizing frictional resistance between the cutting edge and the material C.
- a vibration is minimized at the initial stage of core drilling, thus preventing the shank 10 from being deformed or damaged and thereby lengthening the life span of the core drill and increasing drilling efficiency.
- the notch 13 functions to disperse a force which is concentrated to each sharp edge 12, in addition to serving as a root of saw teeth and a cooling air passage, thus increasing drilling speed.
- each diamond tip 11 is provided with the sharp edge 12 so that a force is concentrated to the sharp edge 12 during the drilling process, thus reducing a cutting surface area and thereby increasing drilling efficiency.
- at least one notch 13 is formed at a predetermined position of each diamond tip 11 so that the force concentrated to the sharp edge 12 is dispersed through the notch 13. In this case, air circulates through the notch 13 to cool the diamond tip 11, thus prolonging the life span of the core drill.
- the shank 10 has the external tapered surface 14 which is tapered upwardly from the lower end of the shank 10.
- the interval between the shank 10 and the material C becomes large, thus smoothly discharging chips and preventing the shank 10 from being caught in the material C.
- the present invention provides a dry core drill, which is designed to prevent a vibration at the initial stage of core drilling, thus maximizing the life span of diamond tips, and which is designed such that its shank has a tapered external surface, so that an interval between the shank and a target material becomes larger when a cut hole becomes deeper, thus minimizing a rotating load on the shank, and preventing the shank from being caught in the rock or concrete structures, thereby maximizing drilling efficiency and life span.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Mining & Mineral Resources (AREA)
- Processing Of Stones Or Stones Resemblance Materials (AREA)
Abstract
The object of the invention is to provide a core drill used for forming holes in rock or concrete structures or extracting cylindrical samples, so-called cores, from rock or concrete structures. The core drill is designed to reduce the contact surface area of its cutting edge with the rock or concrete structures during a drilling process, thus minimizing frictional resistance between the cutting edge and the rock or concrete structures and thereby maximizing drilling efficiency. The core drill also smoothly discharges chips and effectively dissipates heat, thus minimizing abrasion of metal bond holding diamond tips on a shank and thereby having a lengthened life span. The core drill includes diamond tips (11) mounted along the end of a cylindrical shank (10) with a tapered external surface (14). Each diamond tip (11) has a sharp edge (12) with a notch.
Description
CORE DRILL
Technical Field
The present invention relates generally to a core drill which is used for forming holes in rock or concrete structures or extracting cylindrical samples, so- called cores, from rock or concrete structures, and more particularly, to a core drill which is designed to reduce the contact surface area of its cutting edge with the rock or concrete structures during a drilling process, thus minimizing frictional resistance between the cutting edge of the drill and the rock or concrete structures and thereby maximizing drilling efficiency, and which is designed to prevent the abrasion of the core drill, smoothly discharge chips, and effectively dissipate heat, thus minimizing abrasion of metal bond holding diamond tips, therefore preventing diamond granules from being removed from the diamond tips of the drill, and effectively lengthening its life span.
Background Art
As well known to those skilled in the art, core drills are used for forming holes in desired portions of concrete structures or predetermined portions of concrete structures in repair work, and extracting cylindrical samples from rock, concrete structures, or other materials which are difficult to cut, so as to test the rock or concrete structures for strength. Such core drills are typically classified into two types, that is, a wet-type core drill and a dry-type core drill, according to the purpose of the core drills and the hardness of a material to be cut. The wet-type core drill is designed such that water is injected into the core drill during a drilling process. The dry-type core drill performs a drilling process without injecting water into the core drill. In the wet-type core drill, chips are easily discharged to the outside by water injected into the core drill. Meanwhile, in the dry-type core drill, chips are
discharged to the outside without any external assistance, so it is difficult to discharge the chips to the outside.
Fig. 1 is a view showing a conventional dry-type core drill, when the core drill is used to form a hole in a target material, such as a concrete structure or rock. The core drill includes diamond tips 110 welded to the end of a cylindrical shank
100. A connecting unit 200 is mounted on the shank 100 so that the core drill is connected to a core drill drive unit (not shown) via the connecting unit 200.
The core drill is axially assembled with the core drill drive unit through the connecting unit 200. After the core drill is placed on a target material C to be drilled, such as a concrete structure, rock or other materials which are difficult to cut, the core drill is rotated. At this time, the diamond tips 110 are in frictional contact with the material C, thus forming a hole in the material C.
The conventional dry-type core drill has a problem in that frictional resistance is increased, because the contact surface area between the diamond tips 110 and the material C is increased as the hole of the material C becomes deeper.
That is, as shown in Fig. 2, each of the diamond tips 110 has a rectangular cross-section, so the sectional area of the diamond tips 110 is larger than that of the shank 100. Thus, when a force is transmitted from the shank 100 to the diamond tips 110, drilling efficiency is poor, so slippage may occur. Further, a reacting force applied from the material C to the diamond tips 110 during the drilling process is partially dispersed in the shank 100 in radial directions, thus causing a vibration. Due to such a vibration, the granules forming the diamond tips 110 may be removed from the diamond tips 110 or may be deformed, thus reducing drilling efficiency and life span. Further, the conventional dry-type core drill has another problem that the shank 100 has a linear external surface and clearance between the shank 100 and each diamond tip 110 is 0.5-0.75mm, so the shank 100 may get caught in the material C and the chips are not smoothly discharged when the hole of the material C becomes deeper, thus undesirably increasing load. In order to solve the problem, the diamond tips 110 may be designed to be
thicker. However, thicker diamond tips 110 cause a waste of resources, so it is uneconomical. Further, when increasing the thickness of the diamond tips 110, the contact surface area between the edge of the shank 100 and the diamond tips 110 is relatively small, so the diamond tips 110 may be undesirably removed from the shank 100 when the core drill is rotated at a high speed.
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 a core drill, which is designed to reduce the contact surface area of its cutting edge with rock or concrete structures during a drilling process, thus minimizing frictional resistance between the cutting edge of the drill and the rock or concrete structures and thereby maximizing drilling efficiency and minimizing wear on the core drill.
Another object of the present invention is to provide a core drill, which is designed to smoothly discharge chips and effectively dissipate heat, thus minimizing abrasion of metal bond holding diamond tips on a shank to prevent granules of diamond tips from being undesirably removed from the tips, therefore lengthening its life span and maximizing operational efficiency.
In order to accomplish the above object, the present invention provides a core drill including diamond tips along a lower edge of a cylindrical shank at regular intervals, wherein each of the diamond tips has a sharp edge formed at a lower edge of the diamond tip to have a cross-section of an acute angle, and a notch formed at a predetermined portion of the diamond tip in such a way as to be tapered upwardly from the sharp edge, and the cylindrical shank has an external surface which is tapered upwards.
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 view showing a conventional core drill, when the core drill is used to form a hole in a target material;
Fig. 2 is a diagram showing a reacting force applied from the target material to diamond tips, when the conventional core drill forms a hole in the target material;
Fig. 3 is a bottom perspective view showing diamond tips included in a core drill according to the present invention; . ... .
Fig. 4 is a sectional view of the core drill according to the present invention;
Fig. 5 is a sectional view of one of the diamond tips included in the core drill according to the present invention; Fig. 6 is diagram showing a reacting force applied from a target material to the diamond tips, when the core drill of the present invention forms a hole in the target material; and
Fig. 7 is a sectional view of the core drill according to the present invention, when the core drill is used to form a hole in the target material.
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.
As shown in Figs. 3 to 6, a core drill according to the present invention includes a cylindrical shank 10. Diamond tips 11 are mounted along the lower edge of the shank 10 at regular intervals through a welding method.
Each diamond tip 11 is cut to have an acute angle θ at its lower edge, thus forming a sharp edge 12. Further, each diamond tip 11 has a notch 13 which
is tapered upwardly from the sharp edge 12. The shank 10 has a tapered external surface 14, which is tapered upwards.
That is, according to the present invention, each diamond tip 11 is provided with the sharp edge 12 having a cross-section of an acute-angled triangle so as to minimize a contact surface area of its cutting edge with a target material C, such as rock or concrete structures, during a drilling process, thus minimizing frictional resistance between the cutting edge and the material C. Thus, a vibration is minimized at the initial stage of core drilling, thus preventing the shank 10 from being deformed or damaged and thereby lengthening the life span of the core drill and increasing drilling efficiency.
While drilling the material C, the notch 13 functions to disperse a force which is concentrated to each sharp edge 12, in addition to serving as a root of saw teeth and a cooling air passage, thus increasing drilling speed.
As shown in Fig. 5, each diamond tip 11 is provided with the sharp edge 12 so that a force is concentrated to the sharp edge 12 during the drilling process, thus reducing a cutting surface area and thereby increasing drilling efficiency. Further, at least one notch 13 is formed at a predetermined position of each diamond tip 11 so that the force concentrated to the sharp edge 12 is dispersed through the notch 13. In this case, air circulates through the notch 13 to cool the diamond tip 11, thus prolonging the life span of the core drill.
As shown in Fig. 7, the shank 10 has the external tapered surface 14 which is tapered upwardly from the lower end of the shank 10. Thus, as the drilling process proceeds, the interval between the shank 10 and the material C becomes large, thus smoothly discharging chips and preventing the shank 10 from being caught in the material C.
Industrial Applicability
As described above, the present invention provides a dry core drill, which is designed to prevent a vibration at the initial stage of core drilling, thus
maximizing the life span of diamond tips, and which is designed such that its shank has a tapered external surface, so that an interval between the shank and a target material becomes larger when a cut hole becomes deeper, thus minimizing a rotating load on the shank, and preventing the shank from being caught in the rock or concrete structures, thereby maximizing drilling efficiency and life span.
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. A core drill, comprising diamond tips along a lower edge of a cylindrical shank at regular intervals, wherein each of said diamond tips comprises: a sharp edge formed at a lower edge of the diamond tip to have a cross- section of an acute angle; and a notch formed at a predetermined portion of the diamond tip in such a way as to be tapered upwardly from the sharp edge.
2. The core drill according to claim 1, wherein said cylindrical shank has an external tapered surface, which is tapered upwards.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR2020020001509U KR200272178Y1 (en) | 2002-01-17 | 2002-01-17 | Core drill |
| KR20-2002-0001509 | 2002-01-17 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2003059561A1 true WO2003059561A1 (en) | 2003-07-24 |
Family
ID=19718367
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/KR2003/000041 WO2003059561A1 (en) | 2002-01-17 | 2003-01-10 | Core drill |
Country Status (2)
| Country | Link |
|---|---|
| KR (1) | KR200272178Y1 (en) |
| WO (1) | WO2003059561A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1695781A1 (en) * | 2005-02-24 | 2006-08-30 | Marcrist International Limited | Diamond core drill |
| EP1980378A1 (en) * | 2007-04-11 | 2008-10-15 | Carbodrill Srl | Coring tool and connected method of production |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101431196B1 (en) | 2014-02-07 | 2014-08-18 | 임형국 | A cutting tip of core drill bit |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57102712A (en) * | 1980-12-13 | 1982-06-25 | Miyanaga:Kk | Core drill locating device |
| JP2000309013A (en) * | 1999-02-25 | 2000-11-07 | Atokku:Kk | Core drill and core drill device |
| KR200237537Y1 (en) * | 2001-03-19 | 2001-10-08 | 영풍산업 주식회사 | diamond-tip for core drill |
-
2002
- 2002-01-17 KR KR2020020001509U patent/KR200272178Y1/en not_active IP Right Cessation
-
2003
- 2003-01-10 WO PCT/KR2003/000041 patent/WO2003059561A1/en active Application Filing
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57102712A (en) * | 1980-12-13 | 1982-06-25 | Miyanaga:Kk | Core drill locating device |
| JP2000309013A (en) * | 1999-02-25 | 2000-11-07 | Atokku:Kk | Core drill and core drill device |
| KR200237537Y1 (en) * | 2001-03-19 | 2001-10-08 | 영풍산업 주식회사 | diamond-tip for core drill |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1695781A1 (en) * | 2005-02-24 | 2006-08-30 | Marcrist International Limited | Diamond core drill |
| EP1980378A1 (en) * | 2007-04-11 | 2008-10-15 | Carbodrill Srl | Coring tool and connected method of production |
Also Published As
| Publication number | Publication date |
|---|---|
| KR200272178Y1 (en) | 2002-04-17 |
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