Core drilling device, drilling method, and core bit

Abstract

The present invention provides a core drilling device that prevents the core generated when drilling a through hole in an object from falling, and that can properly remove the chips generated when drilling the through hole. [Solution] The dry-type core drill device 1 includes a dust collector 9 and a core bit 2. The core drill device 1 is equipped with a fixing device that can be fixed to the upper surface of a concrete floor CF. The core bit 2 includes a cylindrical core bit body portion 11, a top plate portion 12 extending radially inward from the base end side of the core bit body portion 11, a through hole 12a formed through the top plate portion 12, and a catch lever 21 supported by the top plate portion 12 when inserted through the through hole 12a. The catch lever 21 is configured to be switchable between a first position in which it cannot engage with the fixing device 31 and a second position in which it can engage with the fixing device 31.

Description

Technical Field

[0001] The present invention relates to a core drill device, a drilling method, and a core bit.

Background Art

[0002] Conventionally, a core drill device has been used when forming a cylindrical through-hole in a drilling object such as a concrete floor. For example, in Patent Document 1, before forming a through-hole in a concrete floor using a core drill device, the bottom surface of a fixture is abutted and adhered to the planned drilling position of the concrete floor. Then, when drilling a through-hole in the concrete floor, a locking hook portion of a hooking tool provided on a core bit of the core drill device is locked to a locked portion of the fixture. Thereby, it suppresses the falling of the drilling core generated when drilling a through-hole in the concrete floor.

[0003] Also, in Cited Document 1, a locking release tool is used to release the locked state between the hooking tool and the fixture. The locking release tool includes a pressing rod portion, and by pressing the locking hook portion of the hooking portion while inserting the pressing rod portion into the core bit from a bit hole provided in the core bit, the locked state between the locking hook portion of the hooking portion and the locked portion of the fixture is released.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, in the case of dry core drilling devices, chips generated when drilling into objects such as concrete floors accumulate inside the core bit, so it is necessary to remove these chips by suction using a dust collector. However, if a bit hole for inserting a locking release jig is provided in the core bit, as in Reference 1, this bit hole may hinder the suction removal of chips inside the core bit.

[0006] The present invention has been made in view of the above, and its object is to provide a core drilling device, a drilling method, and a core bit that can suppress the falling of the drilling core generated when drilling a through hole in an object to be drilled, and that can properly remove the chips generated when drilling the through hole. [Means for solving the problem]

[0007] To achieve the above objective, the present invention provides a dry core drilling device having a dust collector and a core bit, comprising a fixing device that can be fixed to the upper surface of a workpiece to be drilled, wherein the core bit has a cylindrical body portion, a top plate portion extending radially inward from the base end of the body portion, a hole formed through the top plate portion, and a catch lever supported by the top plate portion when inserted through the hole, wherein the catch lever is configured to be switchable between a first position in which it cannot engage with the fixing device and a second position in which it can engage with the fixing device.

[0008] According to the present invention configured as described above, when a through hole is drilled in an object to be drilled by a core drilling device while the fixing device is fixed to the upper surface of the object to be drilled, a cylindrical drilling core corresponding to the through hole is generated. At this time, when the catch lever is moved to the second position, the fixing device to which the drilling core is fixed engages with the catch lever. As a result, the drilling core is suspended from the core bit via the fixing device and the catch lever, thus preventing the drilling core from falling. Furthermore, for example, when releasing the engagement between the catch lever and the fixing device, it is only necessary to switch the catch lever from the second position to the first position, eliminating the need to provide a bit hole in the core bit for inserting a locking release jig, as described in Patent Document 1. This makes it possible to properly remove chips from inside the core bit using a dust collector.

[0009] In the present invention, preferably, the catch lever has an operating portion that includes a portion located outside the core bit, and the operating portion is configured to switch the catch lever between the first position and the second position.

[0010] With the present invention configured in this way, the position of the catch lever can be switched by operating the operating part from the outside of the core bit.

[0011] In the present invention, preferably, the catch lever has an engaging portion located inside the core bit, and the fastener has an engaged portion that can engage with the engaging portion, wherein the first position is a position in which the engaging portion cannot engage with the engaged portion, and the second position is a position in which the engaging portion can engage with the engaged portion.

[0012] According to the present invention configured in this manner, when the catch lever is in the first position, the engaging portion located inside the core bit of the catch lever and the engaged portion of the fastener cannot be engaged, whereas when the catch lever is in the second position, the engaging portion located inside the core bit of the catch lever and the engaged portion of the fastener can be engaged.

[0013] In the present invention, preferably, the fixing device further comprises a disc-shaped positioning portion and a support portion connecting the central portion of the disc-shaped engaged portion and the central portion of the positioning portion, wherein the outer diameter of the positioning portion is slightly smaller than the inner diameter of the main body portion, and the fixing device is configured such that, when fixed to the intended drilling location of the object to be drilled, the positioning portion can be positioned on the side of the object to be drilled and the engaged portion can be positioned on the side opposite to the object to be drilled.

[0014] According to the present invention configured in this way, when the fixing device is fixed to the object to be drilled, the outer diameter of the positioning portion located on the object to be drilled is slightly smaller than the inner diameter of the core bit. Therefore, by setting the core bit on the outer circumference of the positioning portion, the core bit can be properly positioned.

[0015] In the present invention, preferably, the fastener further has a fixing hole provided in a continuous manner with the engaged portion, the support portion, and the positioning portion, and further comprises an anchor bolt for fixing the fastener to the object to be drilled, wherein the anchor bolt is configured to be embedded in the object to be drilled when inserted through the fixing hole.

[0016] According to the present invention configured in this manner, the anchor bolt is embedded in the object to be drilled while inserted into the fixing hole, thereby enabling the fixing device to be securely fixed to the object to be drilled.

[0017] In the present invention, preferably, a drilling method using the core drilling device comprises: a fixing step of fixing the fixing device to the upper surface of the object to be drilled; a first drilling step of drilling partway through the object to be drilled by moving the core bit downward while rotating it around the fixing device with the catch lever set to the first position; a first switching step of switching the catch lever from the first position to the second position; and a second drilling step of drilling a through hole in the object to be drilled by moving the core bit downward while rotating it until it penetrates the object to be drilled.

[0018] With the present invention configured in this way, when a through hole is drilled in the object to be drilled in the second drilling step, a cylindrical drilling core corresponding to the through hole is generated. At this time, since the catch lever is in the second position, the fixing device to which the drilling core is fixed engages with the catch lever. As a result, the drilling core is suspended from the core bit via the fixing device and the catch lever, so that the drilling core does not fall when drilling a through hole in the object to be drilled.

[0019] In the present invention, preferably, after the second drilling step, the method includes a removal step of removing the drilled core from the through hole by moving the core bit upward while maintaining the catch lever in the second position, a placement step of placing the drilled core on a placement location, and a second switching step of switching the catch lever from the second position to the first position.

[0020] According to the present invention configured in this way, in the second switching step, the catch lever is switched from a second position in which it can engage with the fixing device to a first position in which it cannot engage with the fixing device. Therefore, it is no longer necessary to provide a bit hole in the core bit for inserting a locking release jig, as in Patent Document 1. This makes it possible to properly remove chips from inside the core bit using a dust collector.

[0021] In the present invention, preferably, after the second switching step, there is an exposure step of exposing the drilling core by moving the core bit upward relative to the drilling core, and a removal step of removing the chips accumulated on the upper side of the drilling core.

[0022] According to the present invention configured in this way, chips accumulated on the upper side of the drilled core can be properly removed.

[0023] In order to achieve the above object, the present invention provides a core bit that can be used in a dry core drill device equipped with a dust collector, the core bit including a cylindrical main body portion, a top plate portion extending radially inwardly on the proximal end side of the main body portion, a hole portion formed through the top plate portion, a catch lever supported by the top plate portion while being inserted through the hole portion and engageable with a fixture that can be fixed to the upper surface of the object to be drilled, wherein the catch lever is configured to be switchable between a first position where it cannot engage with the fixture and a second position where it can engage with the fixture.

[0024] According to the present invention configured as described above, when a through hole is drilled in the object to be drilled by the core bit with the fixture fixed to the upper surface of the object to be drilled, a cylindrical drilling core corresponding to the through hole is generated. At this time, when the catch lever is in the second position, the fixture to which the drilling core is fixed comes to engage with the catch lever. As a result, the drilling core can be suspended from the core bit via the fixture and the catch lever, so that the fall of the drilling core can be suppressed. Further, for example, when releasing the engagement between the catch lever and the fixture, it is only necessary to switch the catch lever from the second position to the first position, so there is no need to provide a bit hole for inserting a locking release jig in the core bit as in Patent Document 1. Thereby, it becomes possible to appropriately suck and remove the chips in the core bit using a dust collector.

Advantages of the Invention

[0025] According to the present invention, it is possible to provide a core drill device, a drilling method, and a core bit that can suppress the fall of the drilling core generated when drilling a through hole in an object to be drilled and can appropriately remove the chips generated in the core bit when drilling the through hole without letting them out to the outside. [[ID=URL]]

Brief Description of the Drawings

[0026] [Figure 1] It is a schematic view showing a core drill device according to an embodiment of the present invention. [Figure 2]This figure shows the steps of a drilling method using a core drill device according to an embodiment of the present invention. [Figure 3] This is a diagram showing the first drilling process. [Figure 4] This is a diagram showing the first switching process. [Figure 5] This is a diagram showing the second drilling process. [Figure 6] This diagram shows the removal and fixing process. [Figure 7] This is a diagram showing the exposure process. [Figure 8] (a) is a cross-sectional view showing the catch lever engaged in the fitting groove, and (b) is a perspective view showing the catch lever. [Modes for carrying out the invention]

[0027] Embodiments of the present invention will be described in detail below with reference to the drawings. The following description of preferred embodiments is essentially illustrative.

[0028] Figure 1 shows a core drilling device 1 according to an embodiment of the present invention. This core drilling device 1 is a dry-type core drilling device and is used for drilling holes in concrete floor CF.

[0029] Furthermore, the core drill device 1 includes a base 3, a pole 4 erected on the base 3, a core drill head 5 supported so as to be slidable vertically relative to the pole 4, a core bit 2 detachably attached to the core drill head 5, and a drill motor 6 supported by the core drill head 5 and capable of rotating the core bit 2.

[0030] Base 3 has a flattened rectangular prism shape. Base 3 is fixed to the upper surface of the concrete floor CF (object to be drilled) using the first anchor bolt 3a. Furthermore, Base 3 is horizontally fixed to the upper surface of the concrete floor CF using the level bolt 3b.

[0031] Pole 4 is columnar in shape. Pole 4 is also equipped with a rack 4a that extends vertically.

[0032] Furthermore, the pole 4 comprises a lower pole section 4b whose lower end is connected to the base 3, and an upper pole section 4c which is continuously provided above the upper end of the lower pole section 4b. In addition, a pin (not shown) extending in the vertical direction is interposed between the lower pole section 4b and the upper pole section 4c. As a result, the upper pole section 4c is configured to rotate freely relative to the lower pole section 4b with the pin as the center of rotation.

[0033] The core drill head 5 is equipped with a pinion (not shown) that meshes with the rack 4a. The core drill head 5 is also provided with a handle (not shown) for rotating the pinion. When the handle is rotated to one side, the core drill head 5 moves downward, and when the handle is rotated to the other side, the core drill head 5 moves upward.

[0034] Furthermore, the core drill head 5 has an output shaft 7 that protrudes downward and is connected to the drill motor 6. A cylindrical core bit 2 is detachably connected to the output shaft 7. When the drill motor 6 is operated, the output shaft 7 connected to the drill motor 6 rotates, and the core bit 2 connected to the output shaft 7 rotates in accordance with the rotation of the output shaft 7.

[0035] Furthermore, a swivel 8 connected to a dust collector 9 via a hose 9a is attached to the outer circumference of the output shaft 7. The swivel 8 is configured to rotate relative to the output shaft 7.

[0036] The core bit 2 comprises a cylindrical core bit body portion 11. In this embodiment, the vertical direction coincides with the cylindrical axis direction of the core bit 2 when it is connected to the output shaft 7. More specifically, one side of the core bit 2 in the cylindrical axis direction coincides with the upper side, and the other side of the core bit 2 in the cylindrical axis direction coincides with the lower side.

[0037] A cutting edge portion 15 is provided at the tip side (the side opposite to the cylindrical axis direction) of the core bit body portion 11. This cutting edge portion 15 is made of, for example, a diamond tip. Furthermore, a top plate portion 12 is provided at the base end side (the side opposite to the cylindrical axis direction) of the core bit body portion 11, extending radially inward.

[0038] The central part of the top plate 12 is provided with a cylindrical mounting portion 13, which has a smaller diameter than the core bit body 11. When the mounting portion 13 is attached to the output shaft 7, the internal space S of the core bit body 11 (core bit 2) and the dust collector 9 are connected via the mounting portion 13, a passage (not shown) inside the output shaft 7, a passage (not shown) inside the swivel 8, and a hose 9a. As a result, the chips CH in the internal space S of the core bit body 11 are sucked and removed by the dust collector 9 via the mounting portion 13, the output shaft 7, the swivel 8, and the hose 9a.

[0039] Furthermore, in the radial direction of the core bit 2, multiple through holes 12a are formed through the top plate portion 12 at positions on the outer circumference side of the mounting portion 13 (see Figure 8(a)). In other words, each through hole 12a is provided so as to penetrate the top plate portion 12 in the thickness direction. In this embodiment, three through holes 12a are provided. The through holes 12a are provided at 120-degree intervals in the circumferential direction of the top plate portion 12. In addition, in this embodiment, a fitting groove 12b (for example, a keyway) is provided on the inner surface of the top plate portion 12, and the through holes 12a are provided so as to open into the fitting groove 12b (see Figure 8(a)).

[0040] Furthermore, the core bit 2 is equipped with an L-shaped catch lever 21. The catch lever 21 is rotatably supported on the top plate portion 12 when inserted through the insertion hole 12a. In this embodiment, the axis of rotation of the catch lever 21 is parallel to the axis of rotation of the core bit 2.

[0041] As shown in Figure 8(b), the catch lever 21 comprises an axial rotating operating portion 22 and a lever body portion 24 having a predetermined thickness and forming an L-shape when viewed in the thickness direction of the catch lever 21.

[0042] The rotating operating part 22 is provided at one end of the catch lever 21 in the rotational axis direction and is configured to allow the catch lever 21 to rotate. Furthermore, a threaded portion 22a is provided on the outer surface of the rotating operating part 22, and this threaded portion 22a is screwed into a threaded hole (not shown) provided in the nut N. In addition, a D-cut surface portion 22b is provided at the tip of the rotating operating part 22 (one end of the catch lever 21 in the rotational axis direction).

[0043] At one end face of the lever body 24 in the rotation axis direction of the catch lever 21, the base end of the rotation operation part 22 (the other end of the catch lever 21 in the rotation axis direction) is fixed to the central part of the lever body 24 in the width direction.

[0044] Furthermore, one end of the catch lever 21 in the lever body 24 in the rotational axis direction is fitted into a fitting groove 12b provided in the top plate 12 (see Figure 8(a)). This restricts the relative rotation of the catch lever 21 with respect to the top plate 12 when, for example, the core bit 2 is rotated (during drilling).

[0045] Furthermore, the width dimension of the lever body 24 decreases as it moves towards the other end in the direction of the rotation axis of the catch lever 21.

[0046] Furthermore, an engaging portion 23 is provided at the other end of the catch lever 21 in the direction of the rotation axis of the lever body 24, extending in a direction perpendicular to the rotation axis. In other words, the engaging portion 23 is provided at the other end of the catch lever 21 in the direction of the rotation axis and is configured to extend in a direction perpendicular to the rotation axis.

[0047] Furthermore, the engaging portion 23 has a tip 23a. This tip 23a is located on the side opposite to the D-cut surface portion 22b in the width direction of the lever body portion 24 (catch lever 21). In other words, the catch lever 21 has the D-cut surface portion 22b on one side in the width direction of the lever body portion 24, and the tip 23a on the other side in the width direction of the lever body portion 24. This makes it possible for an operator to determine the orientation of the tip 23a by visually checking the orientation of the D-cut surface portion 22b.

[0048] A portion of the rotating operating part 22 is inserted through the insertion hole 12a. In other words, the remaining portion of the rotating operating part 22 (the portion not inserted through the insertion hole 12a) is located on one end in the rotational axis direction of the top plate portion 12 in which the insertion hole 12a is provided. That is, the rotating operating part 22 includes a portion located outside the core bit 2. On the other hand, the engaging portion 23 is located on the other end in the rotational axis direction of the top plate portion 12 in which the insertion hole 12a is provided. In other words, the engaging portion 23 is located inside the core bit 2. Furthermore, the lever body portion 24 has a portion located within the fitting groove 12b provided in the top plate portion 12 and a portion located on the other end in the rotational axis direction of the top plate portion 12.

[0049] Furthermore, the core drilling device 1 is equipped with a fixing device 31 that can be fixed to the concrete floor CF. The fixing device 31 has a disc-shaped engaged portion 32 that can engage with the engaging portion 23, a disc-shaped positioning portion 33, and a support portion 34 that connects the central portion of the engaged portion 32 and the central portion of the positioning portion 33. In this embodiment, the outer diameter of the positioning portion 33 is larger than the outer diameter of the engaged portion 32 and slightly smaller than the inner diameter of the core bit body portion 11 (core bit 2).

[0050] Furthermore, the fixing device 31 is equipped with a fixing hole 35 that is continuously provided in the engaged portion 32, the support portion 34, and the positioning portion 33.

[0051] A second anchor bolt 36, used to fix the fastener 31 to the upper surface of the concrete floor CF, is inserted through the fixing hole 35. In this embodiment, the second anchor bolt 36 is configured to be embedded in the concrete floor CF while inserted through the fixing hole 35.

[0052] Next, a drilling method using the core bit 2 will be described. Figure 2 shows each step of the drilling method for drilling a through hole H in a concrete floor CF. In this embodiment, the dust collector 9 is operated while drilling the through hole H to suck up and remove the chips CH generated when drilling the through hole H.

[0053] (Fixed process) In the fixing step S1 shown in Figure 2, a worker or other person fixes the fixing device 31 to the planned drilling location P1 on the upper surface of the concrete floor CF. More specifically, as shown in Figure 1, the fixing device 31 is fixed using a second anchor bolt 36 such that the positioning portion 33 is located on the concrete floor CF side (the side to be drilled) and the engaging portion 32 is located on the opposite side of the concrete floor CF (the side opposite to the side to be drilled). In this embodiment, the side to be drilled is the lower side, and the side opposite to the side to be drilled is the upper side.

[0054] (1st drilling process) In the first drilling step of step S2, the operator moves the core drill head 5 downward by a predetermined amount of movement by operating the drill motor 6 and rotating the handle to one side while the catch lever 21 is set to the first rotation position. In other words, as shown in Figure 3, with the catch lever 21 set to the first rotation position, the core bit 2 is moved downward while rotating around the fixing device 31 to drill partway through the concrete floor CF. Once the concrete floor CF is drilled partway through, the downward movement of the core bit 2 is temporarily stopped. In this embodiment, the predetermined amount of movement is the amount of movement of the core bit 2 (core drill head 5) from the first vertical position where drilling begins (see Figure 1) to the second vertical position (see Figure 3) where the engaging portion 23 of the catch lever 21 is lower than the engaged portion 32 of the fixing device 31. For example, if the thickness of the concrete floor CF is 200 mm, the predetermined amount of movement is 120 mm to 180 mm. In this embodiment, the first drilling step S2 is performed by setting (positioning) the cutting blade portion 15 around the positioning portion 33 of the fixing device 31 before starting to drill the through hole H.

[0055] The first rotation position (first position) is a rotation position in which the engaging portion 23 cannot engage with the engaged portion 32 of the fixing device 31. In this embodiment, the first rotation position is a rotation position in which the tip 23a of the engaging portion 23 faces outward in the radial direction of the core bit 2 (see Figure 3). Also, in the first rotation position, a part of the tip 23a side of the engaging portion 23 and a part of the outer circumference side of the engaged portion 32 of the fixing device 31 do not overlap in a plan view.

[0056] As shown in Figure 3, metal chips CH generated when drilling the concrete floor CF accumulate on the positioning portion 33 of the fixing device 31. In this embodiment, the dust collector 9 is operated while drilling the concrete floor CF. However, since it is difficult for the dust collector 9 to suck up and remove all of the metal chips CH from the internal space S of the core bit 2, metal chips CH that cannot be sucked up and removed by the dust collector 9 accumulate on the positioning portion 33.

[0057] (First switching process) In the first switching step of step S3, the operator grasps the rotating operation part 22 and rotates the catch lever 21 while the downward movement of the core bit 2 is temporarily stopped, thereby switching the catch lever 21 from the first rotation position to the second rotation position. In this embodiment, for example, the catch lever 21 is moved downward relative to the top plate part 12 to a position where it does not engage with the fitting groove 12b by rotating the nut N to one side relative to the rotating operation part 22, and then the catch lever 21 is rotated to switch from the first rotation position to the second rotation position. After switching the catch lever 21 to the second rotation position, for example, the catch lever 21 is moved upward relative to the top plate part 12 to a position where it engages with the fitting groove 12b by rotating the nut N to the other side relative to the rotating operation part 22, thereby engaging the catch lever 21 with the fitting groove 12b.

[0058] The second rotation position (second position) is a rotation position in which the engaging portion 23 can engage with the engaged portion 32 of the fixing device 31. In this embodiment, the second rotation position is a rotation position in which the tip 23a of the engaging portion 23 faces inward in the radial direction of the core bit 2 (see Figure 4). Also, in the second rotation position, a part of the tip 23a side of the engaging portion 23 and a part of the outer circumference side of the engaged portion 32 of the fixing device 31 overlap in a plan view.

[0059] (Second drilling process) In the second drilling step of step S4, with the catch lever 21 switched to the second rotation position, the operator rotates the handle to one side while operating the drill motor 6, thereby moving the core drill head 5 downward until the tip (cutting edge 15) of the core bit 2 penetrates the concrete floor CF. In other words, by rotating and moving the core bit 2 downward until it penetrates the concrete floor CF, a through hole H is drilled at the planned drilling location P1 in the concrete floor CF. This generates a cylindrical drilled core C corresponding to the through hole H (see Figure 5).

[0060] When the through hole H is drilled and the drilled core C is separated from the concrete floor CF, the drilled core C and the fixing device 31 move downward due to their own weight. Subsequently, the lower surface of the engaged portion 32 of the fixing device 31 and the upper part of the engaging portion 23 of the catch lever 21 come into contact (engage), so that the engaged portion 32 of the fixing device 31 is received by the engaging portion 23 of the catch lever 21, and the downward movement of the drilled core C and the fixing device 31 stops. In other words, the engaged portion 32 of the fixing device 31 catches on the engaging portion 23 of the catch lever 21. As a result, the drilled core C is suspended from the top plate portion 12 (core bit 2) via the fixing device 31 and the catch lever 21 (see Figure 5).

[0061] (Removal process) In step S5, the removal process, the operator removes the drilled core C from the through hole H by moving the core bit 2 upward while maintaining the catch lever 21 in the second rotation position (see Figure 6). More specifically, by rotating the handle to the other side, the core drill head 5, which is in a position corresponding to the lower pole portion 4b, is moved upward to a position corresponding to the upper pole portion 4c.

[0062] (Placement process) In the placement process of step S6, the operator places the drilling core C on the placement location P2 (see Figure 7). More specifically, the upper pole portion 4c, which is integrated with the core drill head 5, is rotated relative to the lower pole portion 4b using a pin (not shown) as the pivot point, so that the drilling core C, which is integrated with the core drill head 5, is positioned above the placement location P2. Then, by rotating the handle to one side, the core drill head 5, which is in the position corresponding to the upper pole portion 4c, is moved downward to the position corresponding to the lower pole portion 4b, and the drilling core C is placed on the placement location P2.

[0063] (Second switching process) In the second switching step of step S7, the operator grasps the rotating operation part 22 and rotates the catch lever 21 to switch the catch lever 21 from the second rotation position to the first rotation position. In this embodiment, for example, the catch lever 21 is moved downward relative to the top plate part 12 to a position where it does not engage with the fitting groove 12b by rotating the nut N to one side relative to the rotating operation part 22, and then the catch lever 21 is rotated to switch it from the second rotation position to the first rotation position. After switching the catch lever 21 to the first rotation position, for example, the catch lever 21 is moved upward relative to the top plate part 12 to a position where it engages with the fitting groove 12b by rotating the nut N to the other side relative to the rotating operation part 22, and the catch lever 21 is engaged with the fitting groove 12b.

[0064] (Exposure process) In the exposure step S8, the operator rotates the handle to the other side while maintaining the catch lever 21 in the first rotation position, thereby moving the core bit 2 upward and exposing the drilled core C (see Figure 7).

[0065] (Removal process) In the removal process of step S9, the worker, for example, uses a dust collector 9 to suction and remove the chips CH accumulated on the upper side of the positioning part 33 (perforation core C).

[0066] After the removal process in step S9, the second anchor bolt 36 is removed from the drilled core C, separating the fixing device 31 from the drilled core C. The drilled core C is then discarded, while the fixing device 31 is reused when drilling other through holes (not shown).

[0067] As described above, according to this embodiment, when the fixing device 31 is fixed to the upper surface of the concrete floor CF and a through hole H is drilled in the concrete floor CF by the core drilling device 1, a cylindrical drilled core C corresponding to the through hole H is generated. At this time, when the catch lever 21 is moved to the second rotation position, the fixing device 31 to which the drilled core C is fixed engages with the catch lever 21. As a result, the drilled core C is suspended from the core bit 2 via the fixing device 31 and the catch lever 21, so that the drilled core C does not fall. Furthermore, for example, when releasing the engagement between the catch lever 21 and the fixing device 31, it is sufficient to switch the catch lever 21 from the second rotation position to the first rotation position, so there is no need to provide a bit hole in the core bit for inserting a locking release jig as in Patent Document 1. As a result, it becomes possible to properly remove the chips CH inside the core bit 2 by suction using the dust collector 9.

[0068] Furthermore, the rotation position of the catch lever 21 can be switched by operating the rotation operation unit 22 from the outside of the core bit 2.

[0069] Furthermore, when the catch lever 21 is in the first rotation position, the engaging portion 23 located inside the core bit 2 of the catch lever 21 and the engaged portion 32 of the fixing device 31 cannot be engaged, whereas when the catch lever 21 is in the second rotation position, the engaging portion 23 located inside the core bit 2 of the catch lever 21 and the engaged portion 32 of the fixing device 31 can be engaged.

[0070] Furthermore, when the fixing device 31 is fixed to the concrete floor CF, the outer diameter of the positioning portion 33 located on the concrete floor CF side is slightly smaller than the inner diameter of the core bit 2. Therefore, by setting the core bit 2 on the outer circumference of the positioning portion 33, the core bit 2 can be properly positioned.

[0071] Furthermore, by embedding the second anchor bolt 36 through the fixing hole 35 into the concrete floor CF, the fixing device 31 can be securely fixed to the concrete floor CF.

[0072] Furthermore, when a through hole H is drilled in the concrete floor CF during the second drilling process, a cylindrical drilling core C corresponding to the through hole H is generated. At this time, the catch lever 21 is in the second rotation position, so the fixing device 31 to which the drilling core C is fixed engages with the catch lever 21. As a result, the drilling core C is suspended from the core bit 2 via the fixing device 31 and the catch lever 21, thus preventing the drilling core C from falling when drilling a through hole H in the concrete floor CF.

[0073] Furthermore, in the second switching step, the catch lever 21 is switched from a second rotation position in which it can engage with the fixing device 31 to a first rotation position in which it cannot engage with the fixing device 31. This eliminates the need to provide a bit hole in the core bit for inserting a locking release jig, as described in Patent Document 1. As a result, it becomes possible to properly remove the chips CH inside the core bit 2 by suction using the dust collector 9.

[0074] Furthermore, according to this embodiment, the chips CH accumulated on the upper side of the drilled core C can be properly removed.

[0075] Furthermore, when the fixing device 31 is fixed to the upper surface of the concrete floor CF, and a through hole H is drilled in the concrete floor CF by the core bit 2, a cylindrical drilled core C corresponding to the through hole H is generated. At this time, when the catch lever 21 is moved to the second rotation position, the fixing device 31 to which the drilled core C is fixed engages with the catch lever 21. As a result, the drilled core C is suspended from the core bit 2 via the fixing device 31 and the catch lever 21, thus preventing the drilled core C from falling. Also, for example, when releasing the engagement between the catch lever 21 and the fixing device 31, it is sufficient to switch the catch lever 21 from the second rotation position to the first rotation position, eliminating the need to provide a bit hole in the core bit for inserting a locking release jig, as described in Patent Document 1. This makes it possible to properly remove chips from inside the core bit 2 using the dust collector 9.

[0076] Furthermore, in this embodiment, by using a dry core drilling device 1, it is possible to prevent the generation of sludge water during drilling, as is the case with a wet core drilling device (not shown).

[0077] Furthermore, according to this embodiment, since the through hole H can be drilled while the drilling core C is held inside the core bit 2 by the catch lever 21, it is possible to prevent the chips CH and drilling core C generated during drilling from falling out.

[0078] In this embodiment, an example was described in which the rotation axis direction of the catch lever 21 is parallel to the cylindrical axis direction of the core bit 2. However, the rotation axis direction of the catch lever 21 does not have to be parallel to the cylindrical axis direction of the core bit 2. For example, the rotation axis direction of the catch lever 21 may be set to the horizontal direction.

[0079] Furthermore, although this embodiment describes an example in which an operator or the like grasps the rotating operation part 22 to rotate the catch lever 21, an actuator (not shown) for rotating the catch lever 21 may also be provided.

[0080] Furthermore, although this embodiment describes an example in which a part of the rotating operation unit 22 is located outside the core bit 2, the entire rotating operation unit 22 may also be located outside the core bit 2.

[0081] Furthermore, although an L-shaped catch lever 21 was described in this embodiment, it may also be in a shape other than L-shape (for example, T-shaped).

[0082] Furthermore, although this embodiment describes an example in which the core bit 2 is equipped with three catch levers 21, the core bit 2 may be equipped with one, two, or four or more catch levers 21, as long as it is possible to suppress the falling of the drilled core C.

[0083] Furthermore, although this embodiment describes an example in which the top plate portion 12 is provided with a fitting groove 12b, it is not necessary to provide the fitting groove 12b.

[0084] Furthermore, although this embodiment has been described using an example in which the rotating operation part 22 is provided with a screw thread portion 22a, it is not necessary to provide the screw thread portion 22a.

[0085] Furthermore, although this embodiment has been described using an example in which the rotating operation unit 22 is provided with a D-cut surface portion 22b, it is not necessary to provide the D-cut surface portion 22b.

[0086] Furthermore, although this embodiment has been described using an example in which a nut N having a screw hole (not shown) that can be screwed into the threaded portion 22a of the rotating operating portion 22 is provided, the nut N may not be provided.

[0087] Furthermore, although this embodiment describes an example in which the fixing device 31 includes a positioning portion 33, it is not necessary to include the positioning portion 33.

[0088] Furthermore, although the engaged portion 32 was disc-shaped in this embodiment, it may have a shape other than disc-shaped.

[0089] Furthermore, although this embodiment describes an example in which the fastener 31 is fixed to the concrete floor using a second anchor bolt 36, other fixing members may be used, or adhesive may be used.

[0090] Furthermore, in this embodiment, in the removal step S9, an example was described in which the chips CH accumulated on the upper side of the positioning part 33 (perforating core C) are sucked and removed using a dust collector 9. However, the chips CH accumulated on the upper side of the positioning part 33 (perforating core C) may also be removed using means other than the dust collector 9 (for example, a broom).

[0091] Furthermore, although this embodiment describes an example in which the catch lever 21 is rotatably supported on the top plate portion 12 while inserted through the insertion hole 12a, the catch lever 21 only needs to be configured to switch between a first position in which it cannot engage with the fastener 31 and a second position in which it can engage with the fastener 31 while inserted through the insertion hole 12a. For example, the catch lever 21 may be configured to be supported on the top plate portion 12 so as to be movable along the extending direction of the elongated hole (not shown) provided in the top plate portion 12 while inserted through the elongated hole (not shown) provided in the top plate portion 12. [Industrial applicability]

[0092] The present invention is suitable for core drilling devices, drilling methods, and core bits. [Explanation of Symbols]

[0093] 1 Core drilling device 2 Core Bits 11 Core bit main body (main body) 12 Top panel 12a Through hole (hole) 21 Catch Lever 22 Rotary control unit (control unit) 23 Engaging part 23a tip 31 Fixtures 32 Engaged portion 33 Positioning section 34 Pillar section 35 Fixing hole (fixing hole) 36. Second anchor bolt (anchor bolt) CF concrete floor (object to be drilled) P1 Planned drilling location P2 Installation location S1 Fixed process S2 1st drilling process S3 First switching process S4 2nd drilling process S5 Removal process S6 mounting process S7 Second switching process S8 exposure process S9 removal process

Claims

1. A dry-type core drilling device having a dust collector and a core bit, Equipped with a fixing device that can be fixed to the upper surface of the object to be drilled, The core bit comprises a cylindrical body portion, a top plate portion extending radially inward from the base end of the body portion, a hole formed through the top plate portion, and a catch lever supported by the top plate portion when inserted through the hole. The core drilling device is configured such that the catch lever can be switched between a first position in which it cannot engage with the fixing device and a second position in which it can engage with the fixing device.

2. In the core drilling apparatus according to claim 1, The catch lever has an operating section that includes a portion located outside the core bit, The operating unit is configured to allow the catch lever to be switched between the first position and the second position, in a core drilling device.

3. In the core drilling apparatus according to claim 2, The catch lever has an engaging portion located inside the core bit, The fastener has an engaged portion that can engage with the engaging portion, The first position is a position in which the engaging portion cannot engage with the engaged portion. The second position is a position in which the engaging portion can engage with the engaged portion, in a core drilling device.

4. In the core drilling apparatus according to claim 3, The fixing device further comprises a disc-shaped positioning portion and a support portion connecting the central portion of the disc-shaped engaged portion and the central portion of the positioning portion. The outer diameter of the positioning portion is slightly smaller than the inner diameter of the main body portion. The fixing device is configured such that, when fixed to the intended drilling location of the object to be drilled, the positioning portion can be positioned toward the object to be drilled, and the engaged portion can be positioned toward the opposite side of the object to be drilled.

5. In the core drilling apparatus according to claim 4, The fastener further has a fixing hole provided continuously with the engaged portion, the support portion, and the positioning portion, The fixing device is further provided with anchor bolts for fixing it to the object to be drilled, The core drill device is configured such that the anchor bolt can be embedded in the object to be drilled when inserted through the fixing hole.

6. In a drilling method using a core drill device according to any one of claims 1 to 5, A fixing step of fixing the fixing device to the upper surface of the object to be drilled, With the catch lever set to the first position, the first drilling step involves moving the core bit downward while rotating it around the fixing device, thereby partially drilling the object to be drilled. A first switching step of switching the catch lever from the first position to the second position, A drilling method comprising: a second drilling step of drilling a through hole in the object to be drilled by rotating the core bit and moving it downward until it penetrates the object to be drilled.

7. In the perforation method described in claim 6, After the second drilling step, the core bit is moved upward while the catch lever is maintained in the second position, thereby removing the drilled core from the through hole; A placement step of placing the perforated core in the placement location, A drilling method comprising a second switching step of switching the catch lever from the second position to the first position.

8. In the perforation method described in claim 7, After the second switching step, the core bit is moved upward relative to the drilling core to expose the drilling core in an exposure step, A drilling method comprising a removal step of removing chips accumulated on the upper side of the drilled core.

9. A core bit that can be used in a dry-type core drilling device equipped with a dust collector, The main body is cylindrical, The main body portion has a top plate portion that extends radially inward at its base end, The hole formed through the top plate, It comprises a catch lever that is supported by the top plate when inserted through the hole and can engage with a fixing device that can be fixed to the upper surface of the object to be drilled, The catch lever is configured to be switchable between a first position in which it cannot engage with the fixing device and a second position in which it can engage with the fixing device, in a core bit.

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