Core drills and processing equipment

Abstract

To provide a core drill and a processing device capable of securing a cutting performance of hole boring and capable of smoothly performing the entire work.SOLUTION: A core drill 400 for boring a hole in a building component includes: a cylindrical body 410 including an opening in a front part 411; and a projection part 420 projecting forward from a front end surface 411a of the body 410. The core drill 400 further includes: a welding region 431 that forms a surface of the projection part 420; a welding region 432 formed in an outer peripheral surface of the body 410; and a welding region 433 formed in an inner peripheral surface of the body 410. A cut piece remaining inside the body 410 can be manually discharged from the body 410 without deforming the body 410 after hole boring.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a core drill and a processing device for drilling holes in building members such as walls. [Background technology]

[0002] BACKGROUND ART Conventionally, a core drill having a cylindrical main body, such as that disclosed in Patent Document 1, has been known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Utility Model Registration No. 3218922 Summary of the Invention [Problem to be solved by the invention]

[0004] When drilling holes in building components such as walls using a core drill such as that disclosed in Patent Document 1, cutting ability and smooth operation as a whole are required.

[0005] An object of the present invention is to provide a core drill and a processing device that ensures cutting ability in drilling and allows the entire operation to be carried out smoothly. [Means for solving the problem]

[0006] The present invention is a core drill for drilling holes in building components such as walls, and comprises a cylindrical body having an opening at its front end, a protrusion protruding forward from the front end face of the body, a first abrasive grain-containing portion that forms the surface of the protrusion and contains diamond abrasive grains, a second abrasive grain-containing portion fixed to the outer peripheral surface of the body and containing diamond abrasive grains, and a third abrasive grain-containing portion fixed to the inner peripheral surface of the body and containing diamond abrasive grains.

[0007] According to the present invention, the first abrasive grain-containing portion formed on the surface of the protrusion ensures cutting performance. Furthermore, the second and third abrasive grain-containing portions ensure a clearance between the building material and the main body in the radial direction of the main body. This ensures smooth machining operations while the core drill is driven. Furthermore, the third abrasive grain-containing portion forms the clearance, making it easy to remove shavings remaining inside the main body after the building material has been penetrated. For example, the shavings can be removed by tilting and shaking the main body. This ensures smooth operation throughout the entire process.

[0008] In addition, in the present invention, it is preferable that the plurality of protrusions are formed so as to be spaced apart from one another in the circumferential direction of the main body, and that the second and third abrasive grain-containing portions are formed within a plurality of forming ranges that overlap with the plurality of protrusions in the circumferential direction and are spaced apart from one another in the circumferential direction. In this way, the abrasive grain-containing portions are formed within a limited range within each forming range. This makes it possible to reduce the amount of abrasive grains and the material used to secure them to the main body.

[0009] In addition, in the present invention, the protrusion includes a main body protrusion formed as a part of the main body and the first abrasive grain-containing portion formed on the surface of the main body protrusion, whereby the base of the protrusion is formed as a part of the main body, thereby simplifying the manufacturing process.

[0010] A processing device according to another aspect of the invention includes the above-described core drill and a suction flow passage portion that sucks cutting powder generated during drilling by the core drill by sucking the inside of the main body.

[0011] Drilling of building components is prone to generating a large amount of dust due to cutting powder. According to the above-described configuration of the present invention, the generation of dust is suppressed, which makes it easier to carry out drilling work smoothly.

[0012] In addition, in the present invention, it is preferable that the third abrasive grain-containing portion is partially formed in the front portion of the main body in the front-to-rear direction, and that multiple formed areas in which the third abrasive grain-containing portion is formed are arranged circumferentially around the main body so that non-formed areas in which the third abrasive grain-containing portion is not formed are sandwiched between them. This makes it easy for an air flow path to be formed from the opening at the front end of the main body to the rear of the main body through the non-formed areas, even if chips are present inside the main body during drilling. This makes it easy for suction inside the main body to be performed smoothly through the suction flow path.

[0013] In addition, in the present invention, it is preferable that the width of the non-forming area in the circumferential direction is equal to or greater than the width of the plurality of protrusions in the circumferential direction of the main body. The width of the non-forming area is ensured. Therefore, an air flow path through the non-forming area is easily ensured. Note that "width" here means the maximum size of one protrusion in the circumferential direction. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 2 is a left side view of the core drill and processing device according to the embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged view of the core drill of FIG. 1. [Figure 3] 3 is a cross-sectional view of the core drill of FIG. 2 taken along line III-III' with remaining shavings. [Figure 4] 4(a) is a front view of the core drill of Fig. 2. (b) is an enlarged view of the part surrounded by the dashed dotted line IVb in (a). [Figure 5] FIG. 3 is a perspective view showing the front part of the core drill of FIG. 2. [Figure 6] 6 is a partially enlarged view of one forming area A surrounded by a dashed line VI in FIG. 2. FIG. [Figure 7] FIG. 10 is a left side view of a core drill according to another embodiment of the present invention. [Figure 8] 8 is a cross-sectional view of the core drill of FIG. 7 taken along the vertical direction and including the C′ axis. DETAILED DESCRIPTION OF THE INVENTION

[0015] [First embodiment] A core drill 400 and a processing device 1 according to a first embodiment of the present invention will be described below with reference to Figs. 1 to 6. The processing device 1 has a core drill 400, a center pin 20, a suction flow path section 500, a drill attachment section 40, and an electric drill section 300. In the following, as shown in Fig. 1, the longitudinal direction of the processing device 1 is referred to as the front-rear direction, a direction perpendicular to the front-rear direction is referred to as the left-right direction, and a direction perpendicular to both the left-right direction and the front-rear direction is referred to as the up-down direction. These directions are directions assuming one mode of drilling using the processing device 1, and the processing device 1 does not necessarily always follow these directions.

[0016] The core drill 400 is a drill for drilling holes in building components such as walls, floors, and ceilings. As shown in FIG. 2, the core drill 400 has a main body 410, a protrusion 420, and a welding portion 430. As shown in FIGS. 2 to 4(a), the main body 410 is cylindrical and has openings at a front portion 411 and a rear portion 412. A connecting portion 100, which will be described later, is connected to the rear end of the rear portion 412. A female thread is formed on the inner peripheral surface of the connecting portion. As shown in FIG. 6, a main body protrusion 410a that protrudes forward is formed on the front end surface 411a of the front portion 411 of the main body 410. The main body protrusion 410a is a part of the main body 410 and is configured integrally with the other portions of the main body 410. The main body protrusion 410a is disposed inside a welding region 431 of the welding portion 430, which will be described later. The main body protrusion 410a has a shape that is slightly smaller than the protrusion 420 described below.

[0017] As shown in FIG. 4(a), eight protrusions 420 are provided on the front portion 411 of the main body 410. The eight protrusions 420 are formed across each forming range A in the circumferential direction D relative to the central axis C of the core drill 400. The forming ranges A are aligned along the circumferential direction D and are arranged at equal intervals so as to be separated from each other in the circumferential direction D. As shown in FIGS. 4(b) and 6, each protrusion 420 is composed of a main body protrusion 410a and a welding region 431 of a welding portion 430 (described below) formed on the main body protrusion 410a. As shown in FIG. 2, each protrusion 420 protrudes forward from the front end surface 411a of the main body 410. The following description will mainly focus on the protrusion 420 located nearest to the front in FIG. 2. As shown in FIG. 6, the protrusion 420 is a plate-like member having a rough trapezoidal shape. As shown in FIG. 5 , the protrusion 420 has a front end surface 421, an inclined end surface 422, an orthogonal end surface 423, an outer surface 424, and an inner surface 425. The front end surface 421 extends in a direction perpendicular to the front-to-rear direction and is parallel to the front end surface 411 a of the main body 410. The inclined end surface 422 is an end surface that inclines from the front to the rear and downward. The orthogonal end surface 423 is an end surface that is perpendicular to the front end surface 421. The outer surface 424 is a surface that extends forward from a position slightly outside the outer circumferential surface of the main body 410. The inner surface 425 is a surface that extends forward from a position slightly inside the inner circumferential surface of the main body 410. As shown in FIG. 5 , these surfaces are arranged such that the orthogonal end surface 423 is located forward of the inclined end surface 422 in the rotation direction of the core drill 400 (described later).

[0018] In each of the forming areas A shown in FIG. 4(a) where the protrusions 420 are formed, a welded portion 430 shown in FIGS. 4(a), 4(b), and 6 is formed. The welded portion 430 is a portion where diamond abrasive grains are fixed to the front portion 411 of the main body 410. The abrasive grains are fixed to the surface of the front portion 411 by welding using a metal binder. The binder is made of a non-ferrous metal such as copper, zinc, lead, tin, aluminum, magnesium, or titanium, or an alloy thereof. The welded portion 430 is formed from the binder and the fixed abrasive grains. As shown in FIG. 4(a), the welded portion 430 is formed in each of the forming areas A that are separated from each other in the circumferential direction D of the main body 410. The forming areas A are arranged so that a non-forming area B, where the welded portion 430 is not formed, is sandwiched between them. The width of the non-forming area B in the circumferential direction D is greater than the width of the protrusions 420 in the circumferential direction D.

[0019] 3 and 6, the welded portion 430 has welded regions 431 (a first abrasive grain-containing portion according to the present invention), 432 (a second abrasive grain-containing portion according to the present invention), and 433 (a third abrasive grain-containing portion according to the present invention). Each of the welded regions 431 to 433 contains one or more abrasive grains.

[0020] 4(b) and 5, the welded region 431 is a region that forms the entire surface of the protrusion 420, and is included in the formation range A in the circumferential direction D. The welded region 431 is formed on the surface of the main body protrusion 410a, which is part of the main body 410, so as to include the main body protrusion 410a therein.

[0021] The welded region 432 is a region formed on the outer peripheral surface of the front portion 411 of the main body 410, extending rearward from the rear end of the outer surface 424 of each protrusion 420. The welded region 432 has a rough rectangular shape. As shown in FIG. 5 , the welded region 432 protrudes toward the outside of the main body 410. The welded region 432 is included within the formation range A in the circumferential direction D, and overlaps with the protrusion 420 in the circumferential direction D.

[0022] The welded regions 433 are regions formed on the inner circumferential surface of the front portion 411 of the main body 410, extending rearward from the rear end of the inner surface 425 of each protrusion 420. The welded regions 433 have a rough rectangular shape. As shown in FIG. 5 , the welded regions 433 protrude toward the inside of the main body 410. The welded regions 433 are included within the formation range A in the circumferential direction D and overlap with the protrusions 420 in the circumferential direction D. The welded regions 432 and 433 that are closest to each other are formed over approximately the same range in the circumferential direction D.

[0023] As shown in FIG. 1 , the center pin 20 is a cylindrical member extending in the front-rear direction along the central axis C of the core drill 400. The center pin 20 has a main body 23, a front end 21, and a rear end 22. The center pin 20 is slightly longer than the core drill 400, and its front end 21 protrudes further forward from the front end surface 421 of the protrusion 420. The front end 21 has a conical structure. The rear end 22 is connected to the connecting part 100, which will be described later. The main body 23 is separated into a front half and a rear half that are slidable relative to each other in the front-rear direction. A spring is provided inside the center pin 20 to press the front half forward relative to the rear half. When the processing device 1 is pressed against the building component while the tip of the center pin 20 is pressed against the center of the intended drilling location, the front half of the center pin 20 slides rearward against the pressing force of the spring, and each of the protrusions 420 of the core drill 400 comes into contact with the intended drilling location.

[0024] As shown in Figure 1, the suction flow path section 500 has a connection section 100, a swivel 30, and a hose connecting section 35. The connection section 100 has a general cylindrical shape extending in the front-to-rear direction. A male thread is formed on the outer peripheral surface of the front end section 110 of the connection section 100. This male thread is connected to a female thread formed on the rear section 412 of the main body 410 of the core drill 400. The drill attachment section 40 is connected to the rear end section 120 of the connection section 100.

[0025] The swivel 30 has a roughly cylindrical shape. The connection part 100 is inserted into the cylinder of the swivel 30. A bearing is housed in the swivel 30, which allows the swivel 30 and the connection part 100 to rotate smoothly relative to each other. The bearing is supported on the connection part 100 by a fastener.

[0026] A flow path (not shown) for sucking air and cutting powder from the main body 410 of the core drill 400 is formed in the connecting part 100 and the swivel 30. This flow path communicates with the space inside the main body 410 and also communicates with a flow path in the hose connecting part 35 connected to the lower end of the swivel 30.

[0027] The hose connecting portion 35 protrudes from the outer periphery of the swivel 30 in the radial direction relative to the central axis C. A dust collection flow path is formed within the hose connecting portion 35. As shown in FIG. 1 , a hose 200 is connected to the hose connecting portion 35. The hose 200 is connected to a dust collecting device (not shown). The dust collecting device sucks in cutting dust generated in the core drill 400 via the connection portion 100 of the suction flow path portion 500, the swivel 30, the hose connecting portion 35, and the flow path within the hose 200.

[0028] The drill attachment part 40 is a member for attaching the connection part 100, to which the core drill 400 is connected, to the motor-driven drill part 300. The drill attachment part 40 extends in the front-to-rear direction. A front end part 41 of the drill attachment part 40 is connected to a rear end part 120 of the connection part 100. A rear end part 42 of the drill attachment part 40 is removably inserted into a drill chuck 310, which will be described later.

[0029] As shown in Fig. 1, the motorized drill unit 300 has a drill chuck 310, a switch 320, and a main body 330. The drill chuck 310 has an insertion hole into which the drill attachment unit 40 can be inserted. The switch 320 switches the motorized drill unit 300 on and off. The drill chuck 310 is fixed to the front end of the main body 330. Note that instead of a drill chuck type like the drill chuck 310 and the drill attachment unit 40, an SDS hammer chuck type may be adopted for the processing device 1. The main body 330 is supplied with power via a power cord, or is internally provided with a battery.

[0030] The drill motor 300 rotates the core drill 400 connected to the drill chuck 310 via the suction channel 500 in one direction (the direction shown in FIG. 5) in the circumferential direction D about the central axis C of the core drill 400.

[0031] Next, an example of how to use the processing device 1 according to the above embodiment will be described with reference to Figures 1 to 6. The following description assumes that the object to be processed is a wall. First, connect the hose 200 to the hose connecting portion 35, and then connect the dust collecting device to the processing device 1.

[0032] Next, while pressing the front end 21 of the center pin 20 against the center of the planned hole drilling location on the wall, the processing device 1 is pressed against the wall so that the central axis C is perpendicular to the wall surface. As a result, as described above, the protrusion 420 of the core drill 400 comes into contact with the planned hole drilling location.

[0033] The dust collector is switched on to begin suction, and the switch 320 of the electric drill unit 300 is switched on to rotate the drill chuck 310. This rotates the processing device 1, causing the protrusion 420 of the core drill 400 to cut the wall. Once cutting has progressed to a certain depth, the switch 320 of the electric drill unit 300 is temporarily switched off, and the center pin 20 is removed from the core drill 400. Thereafter, the electric drill unit 300 is turned on again, and cutting resumes to drill the hole.

[0034] The core drill 400 cuts the wall by mainly causing the welding region 431 of the welding portion 430 to cut the wall material as the core drill 400 rotates. As described above, the welding regions 432 and 433 of the welding portion 430 protrude toward the inside and outside of the main body 410. As a result, as cutting progresses, the wall material that has entered the core drill 400, that is, the outer peripheral surface of the shavings W shown in Figures 3 and 4, is cut. For this reason, a clearance is formed between the core drill 400 and the shavings W in the radial direction of the core drill 400 (the direction perpendicular to the circumferential direction D).

[0035] The cutting dust generated during drilling passes through the inside of the core drill 400, through the connection part 100, and through the swivel 30, and is discharged from the suction passage of the hose connection part 35 to a dust collector connected to the hose 200.

[0036] 3, a shaving W of the wall remains inside the main body 410 of the core drill 400. As described above, a clearance is formed between this shaving W and the inner surface of the core drill 400. Therefore, the shaving W can be easily removed from the core drill 400 by tilting the main body 410 so that the opening of the front part 411 of the main body 410 faces downward and swinging the main body 410.

[0037] According to the first embodiment described above, cutting ability can be ensured by the welding area 431 formed on the surface of the protrusion 420. In addition, the welding areas 432 and 433 ensure clearance between the building component and the main body 410 in the radial direction of the main body 410 of the core drill 400. This ensures smooth machining operations while the core drill 400 is in operation.

[0038] Furthermore, since the welded region 433 forms the clearance, after the construction member has been penetrated, the shavings W remaining in the main body 410 can be easily discharged. This allows the entire operation to be carried out smoothly.

[0039] The welded portion 430 is formed in a limited area within each forming range A. Therefore, the amount of abrasive grains and the amount of material used to fix them to the core drill 400 can be reduced.

[0040] The main body protrusion 410a, which is the base of the protrusion 420, is formed as part of the main body 410 of the core drill 400. Therefore, the manufacturing process can be simplified compared to when the protrusion 420 is manufactured as a separate member from the main body 410 and then fixed to the main body 410.

[0041] Drilling of building components is prone to generating a large amount of dust due to cutting powder. The configuration including the suction flow path section 500 suppresses the generation of dust, making it easier to carry out drilling work smoothly.

[0042] The welded regions 433 are formed in respective forming areas A that are separated from one another in the circumferential direction of the main body 410. Each forming area A formed in the welded portion 430 is arranged so that a non-forming area B, where no welded region 433 is formed, is sandwiched between the adjacent forming area A. Therefore, even if a shavings W are present in the main body 410 of the core drill 400 during drilling, an air flow path is easily formed from the opening in the front end surface 411a of the main body 410 to the rear inside the main body 410 through the non-forming area B. Therefore, suction inside the main body 410 through the suction flow path portion 500 is easily performed smoothly.

[0043] The width of the non-forming area B of the main body 410 in the circumferential direction D is greater than the width of the protrusion 420 in the circumferential direction D. Since the width of the non-forming area B is ensured, an air flow path through the non-forming area B is easily ensured.

[0044] By using the core drill 400 with the above features, it is possible to complete drilling of building components made of various materials and thicknesses, such as siding, insulation, and plywood, all at once. Conventional core drills typically use different types of drills for different components, such as metal and wood. Therefore, when drilling building components made of composite materials, drilling must proceed by switching between different types of drills. Even if a conventional core drill is used to complete drilling of a building component, the shavings remaining inside the core drill cannot be easily removed. For example, a process is required to remove the core drill from the motor and remove the shavings. In contrast, as described above, the core drill 400 can complete drilling of a building component all at once and easily remove the shavings, allowing for smooth and rapid work.

[0045] [Second embodiment] A core drill 600 according to a second embodiment, which is yet another embodiment of the present invention, will be described below with reference to Figures 7 and 8. The core drill 600 has a configuration that allows it to be used in place of the core drill 400 in the processing device 1 according to the first embodiment. Much of the configuration of the core drill 600 is similar to that of the core drill 400. Therefore, in the following description of the core drill 600, differences from the core drill 400 will be mainly described, and common configurations will be designated by the same reference numerals as above, and descriptions thereof will be omitted as appropriate.

[0046] The core drill 600 has a main body 610, a protrusion 620, and welded portions 631-633. The main body 610 is cylindrical, and slits 610b and 610c are formed in the front portion. The slits 610b and 610c penetrate the wall of the core drill 600 in the thickness direction. The slits 610b and 610c are aligned in the circumferential direction about the central axis C' of the core drill 600. Both the slits 610b and 610c are inclined with respect to the front-to-rear direction. Each slit is inclined in such a way that the more rearward the portion in the front-to-rear direction along the central axis C' is, the more rearward it is positioned in the rotational direction of the core drill 600. In the inclination direction, the slit 610b is longer than the slit 610c.

[0047] A main body protrusion 610a is formed between the slits 610b and 610c. The main body protrusion 610a is a part of the main body 610 and is configured integrally with the other parts of the main body 610. The main body protrusion 610a protrudes forward from a front end surface 611a (see FIG. 7) of the main body 610. The main body protrusion 610a is disposed inside a welded portion 631, which will be described later. The main body protrusion 610a has a shape that is slightly smaller than a protrusion 620, which will be described later.

[0048] A plurality of protrusions 620 are provided on the front of the main body 610. As shown in Fig. 7, each protrusion 620 is composed of a main body protrusion 610a and a welded portion 631 (described below) formed on the main body protrusion 610a. The following description will mainly take as an example the protrusion 620 located furthest back in Fig. 6 (the protrusion 620 closest to the central axis C' in the figure). Each protrusion 620 has a rough shape of a parallelogram when viewed in the radial direction relative to the central axis C'.

[0049] 7 and 8 are formed on each of the protrusions 620. The welded portions 631 to 633 are portions where diamond abrasive grains are fixed to the front of the main body 610. The material constituting these welded portions is the same as that used for the welded portion 430 according to the first embodiment.

[0050] 7 and 8, welded portion 631 is a portion that forms the entire surface of protrusion 620. Welded portion 631 is formed on the surface of main body protrusion 610a, which is part of main body 610, so as to include main body protrusion 610a therein. Welded portion 631 includes a region that forms outer peripheral surface 621 of each protrusion 620, a region that forms inner peripheral surface 622, and a region that forms the front end of each protrusion 620.

[0051] Welded portion 632 is formed in a region rearward of both slits 610b and 610c on the outer peripheral surface of the front portion of main body 610. Welded portion 632 has a rough parallelogram shape when viewed in the radial direction about central axis C', and extends in a direction inclined with respect to the front-to-rear direction. Welded portion 633 is formed in a region rearward of both slits 610b and 610c on the inner peripheral surface of the front portion of main body 610. The front end of welded portion 633 is located at the same position as the front end of welded portion 632, but welded portion 633 is shorter in the front-to-rear direction than welded portion 632.

[0052] According to the second embodiment described above, cutting ability can be ensured by the welded portion 631 formed on the surface of the protrusion 620. In addition, the welded portions 632 and 633 ensure clearance between the wall and the main body 610 in the radial direction of the main body 610 of the core drill 600. This ensures smooth machining operation while the core drill 600 is being driven.

[0053] Furthermore, since the welded portion 633 forms the clearance, after the construction member has been penetrated, the shavings W remaining inside the main body 610 can be easily discharged. This allows the entire operation to be carried out smoothly.

[0054] The main body protrusion 610a, which is the base of the protrusion 620, is formed as part of the main body 610 of the core drill 600. Therefore, the manufacturing process can be simplified compared to when the protrusion 620 is manufactured as a separate member from the main body 610 and then fixed to the main body 610.

[0055] Furthermore, even if a cutting piece W (see FIGS. 3 and 4(a)) is present inside the main body 610 of the core drill 600 during drilling, an air flow path is likely to be formed through the slits 610b and 610c. In particular, the slit 610b is longer than the slit 610c. Therefore, even if the cutting piece W is relatively thick and overlaps with the slit 610c in the front-to-rear direction, the rear part of the slit 610b is likely to communicate between the outside and the inside of the main body 610. Therefore, suction inside the main body 610 through the suction flow path section 500 is likely to be performed smoothly.

[0056] By using the core drill 600 having the above features, it is possible to complete drilling in a wall made of various materials and thicknesses, such as siding, insulation, and plywood, all at once, just like the core drill 400 of the first embodiment. Furthermore, since the cutting chips can be easily removed from the core drill 600 after the processing work, the work can be carried out smoothly and quickly.

[0057] <Modification> The above is a description of a preferred embodiment of the present invention, but the present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the means for solving the problems.

[0058] For example, in the first embodiment described above, main body protrusion 410a is a part of main body 410 and is configured integrally with other parts of main body 410. However, main body protrusion may be fabricated as a separate member from main body 410. In this case, welding region 431 is formed on the separate member to fabricate the protrusion, and the fabricated protrusion is then fixed to the front end of the main body.

[0059] In the first embodiment described above, there are eight protrusions 420, but the number of protrusions 420 may be two or more.

[0060] In the first embodiment described above, the widths of the protrusions 420 in the circumferential direction D are the same. However, the widths of the protrusions in the circumferential direction may be different. In this case, it is preferable that the width of the non-forming area B in the circumferential direction D is larger than the width of any of the protrusions.

[0061] In the first embodiment described above, the shape of the protrusion 420 is roughly a trapezoid. However, the shape of the protrusion may be a trapezoid different from that of the protrusion 420, or may be another quadrilateral such as a parallelogram, a triangle, or another polygonal shape.

[0062] In the first embodiment described above, the protrusions 420 have the same shape and size, but one or more of the shape and size of the protrusions may be different from each other.

[0063] In the first embodiment described above, the welded portions 430 (i.e., the welded regions 431, 432, and 433) are formed in each of the formed areas A sandwiching the non-formed areas B therebetween in the circumferential direction D. In contrast, the welded portion 430 may include a portion formed in the front part 411 of the main body 410 over the entire range of its outer circumferential surface in the circumferential direction D.

[0064] In the first embodiment described above, the welded regions 432 and 433 that are closest to each other are formed over approximately the same area in the circumferential direction D. However, the sizes of these welded regions may be different. Furthermore, the formation areas of these welded regions may only partially overlap in the circumferential direction D, or may not overlap at all.

[0065] In the first embodiment described above, the welded regions 431, 432, and 433 that are closest to each other are formed in the same formation range A. However, the formation ranges of these welded regions may be different from each other in the circumferential direction D.

[0066] The welded region 431 extends over the entire surface of each protrusion 420. However, the welded region 431 may be present on only a portion of the surface of the protrusion 420.

[0067] The welded region 432 covers the same area as the protrusion 420 (welded region 431) in the circumferential direction D. However, the welded region 432 may only partially overlap with the protrusion 420 in the circumferential direction D.

[0068] The welded region 433 covers the same area as the protrusion 420 (welded region 431) in the circumferential direction D. However, the welded region 433 may only partially overlap with the protrusion 420 in the circumferential direction D.

[0069] The plurality of abrasive grains contained in the welded portion 430 may also include abrasive grains made of materials other than diamond. The abrasive grains in the welded regions 431 to 433 may have different compositions. The bonding materials in the welded regions 431 to 433 may also be different.

[0070] In the second embodiment described above, the plurality of abrasive grains contained in each of the welded portions 631 to 633 may include abrasive grains made of materials other than diamond. Furthermore, the abrasive grain configuration may be different between the welded portions 631 to 633. Furthermore, the binder between the welded portions 631 to 633 may be different between the welded portions 631 to 633.

[0071] In the first embodiment described above, the width of the non-forming area B in the circumferential direction D is larger than the width of the protrusion 420 in the circumferential direction D. However, the width of the non-forming area B in the circumferential direction D may be the same as the width of the protrusion 420 in the circumferential direction D, or may be smaller than the width of the protrusion 420 in the circumferential direction D.

[0072] In each of the above-described embodiments, if the building material to be processed by the core drill contains asbestos, it is preferable to use an asbestos-compatible dust collector using a HEPA filter (High Efficiency Particulate Air Filter) or the like as the dust collector used in the processing device, which allows processing work to be performed without scattering asbestos dust around.

[0073] In each of the above-described embodiments, one or more through holes may be formed in the side of the cylindrical body of the core drill. Through holes 701 and 702 in FIGS. 2 and 7 are examples of such through holes. Through hole 701 is located forward of the center of the body in the front-to-back direction. Through hole 701 is used when shavings remaining in the front part of the body after processing of a building component are difficult to remove. For example, the tip of a screwdriver can be inserted into the body from outside through through hole 701 and used to push the shavings forward, thereby removing them from the body.

[0074] Through-hole 702 is located behind the center of the main body in the front-to-rear direction. Without through-hole 702, cutting chips could clog the front part of the main body during processing of a building component, preventing air from flowing into the main body from the front end, which could result in suction within the main body through the suction passage. In contrast, if through-hole 702 is formed behind the cutting chips, even if air is prevented from flowing into the main body from the front end, air will flow into the main body through through-hole 702, ensuring suction within the main body through the suction passage. [Explanation of symbols]

[0075] 1 Processing equipment 400 Core Drill 410 Main Unit 410a Main body protrusion 411a Front end 420 Protrusion 431~433 Welding area 500 Suction channel section A Formation Range B. Non-formation range

Claims

1. A core drill for drilling holes in building components, a cylindrical body having an opening at its front end; a protrusion formed on a front portion of the main body and protruding forward; a first abrasive grain-containing portion that forms the surface of the protrusion and contains diamond abrasive grains; a second abrasive grain-containing portion fixed to the outer peripheral surface of the main body and containing diamond abrasive grains; a third abrasive grain containing portion fixed to the inner circumferential surface of the main body and containing diamond abrasive grains, The core drill, wherein both the second abrasive grain-containing portion and the third abrasive grain-containing portion are spaced rearward from the first abrasive grain-containing portion.

2. A plurality of slits inclined relative to the front-rear direction are formed in the front part of the body so as to be aligned in the circumferential direction of the body, The core drill according to claim 1, wherein the protrusions are located between the plurality of slits.

3. The plurality of protrusions are formed so as to be spaced apart from one another in the circumferential direction of the main body, 2. The core drill according to claim 1, wherein each of the second and third abrasive grain-containing portions overlaps with each of the plurality of protrusion portions in the circumferential direction and is formed within a plurality of forming ranges that are spaced apart from each other in the circumferential direction.

4. The core drill according to claim 1, characterized in that the protrusion portion includes a main body protrusion portion formed as part of the main body, and the first abrasive grain-containing portion formed on the surface of the main body protrusion portion.

5. The core drill according to any one of claims 1 to 4, a suction passage portion that sucks cutting powder generated during drilling by the core drill by sucking the inside of the main body.

6. the third abrasive grain-containing portion is partially formed in a front portion of the main body in the front-rear direction, The processing device described in claim 5, characterized in that, in the circumferential direction of the main body, multiple formation areas in which the third abrasive grain containing portion is formed are arranged so as to sandwich non-formation areas in which the third abrasive grain containing portion is not formed between them.

7. The plurality of protrusions are formed so as to be spaced apart from one another in the circumferential direction of the main body, 7. The processing device according to claim 6, wherein the width of the non-forming area in the circumferential direction is equal to or greater than the width of the plurality of protrusions in the circumferential direction of the main body.

8. A core drill for drilling holes in building components and a method for producing the same. a suction flow path portion for suctioning cutting powder, The core drill a cylindrical body having an opening at its front end; a protrusion formed on a front portion of the main body and protruding forward; a first abrasive grain-containing portion that forms the surface of the protrusion and contains diamond abrasive grains; a second abrasive grain-containing portion fixed to the outer peripheral surface of the main body and containing diamond abrasive grains; a third abrasive grain containing portion fixed to the inner circumferential surface of the main body and containing diamond abrasive grains, a through hole having a closed outer edge when viewed from the outside of the body is formed in the body; the suction channel portion is connected to the main body, The inside of the main body is suctioned through the suction flow path portion, and at that time, the opening and the through The air outside the main body flows into the main body through at least the latter of the holes. Processing equipment.

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