JP2023018488A - Drilling method and drilling device - Google Patents

Abstract

To provide a drilling method and a drilling device capable of efficiently performing drilling.SOLUTION: A first tip part 30 comprises: plural tips 31 arranged so as to be separated at a circumferential face on a side of a drilling direction of a cylindrical body; and a center drill arranged at the center of the cylindrical body and having a tip part projected from the tips 31 in the drilling direction. Using a first core bit 25 fitted with the first tip part 30, while drilling a surface of a concrete member 10 by a drill blade part 37 of the center drill, a guide groove is formed. Thereafter, a second core bit fitted with the plural tips 31 arranged so as to be separated at the circumferential face on the side of the drilling direction of the cylindrical body is inserted into the guide groove to perform drilling.SELECTED DRAWING: Figure 1

Description

The present invention relates to a drilling method and a drilling apparatus for forming holes in concrete members or the like.

A drilling device equipped with a cylindrical core bit is known for drilling a structure such as concrete (see, for example, Patent Document 1). The drilling device described in this document moves a core bit straight while rotating to form a hole in an object to be drilled. Further, this drilling device is provided with a suction part arranged in the inner space of the shank of the core bit and having a suction port formed on the outer circumference.

JP 2017-177740 A

If the length from the core drill support to the tip of the bit with the blade is long, and if the concrete member to be drilled is hard, the tip of the core bit may swing due to centrifugal force when cutting into the concrete member. Therefore, smooth perforation was difficult.

A drilling method for solving the above problems is a drilling method for forming holes in an object to be drilled using a core drill having a core bit, wherein a plurality of first tips are arranged on the circumference of a cylindrical body on the drilling direction side. and a center drill having a tip protruding from the first tip in the drilling direction. While drilling with the center drill, a guide groove is formed, and a second core bit having a plurality of second chips arranged on the circumference of the cylindrical body in the drilling direction is inserted into the guide groove to drill.

Further, a drilling device for solving the above problems is a drilling device for drilling an object to be drilled using a core drill having a core bit, wherein the core bits are arranged on the circumference of a cylindrical body on the drilling direction side. and a center drill arranged at the center of the cylindrical body and having a tip end protruding from the first tip in the drilling direction, and forming a guide groove while drilling the surface of the drilling object with the center drill. The first tip portion to be formed and the second tip portion that can be arranged in the guide groove and are provided with a plurality of second tips arranged on the circumference of the cylindrical body on the drilling direction side are exchanged and mounted. It is possible.
A drilling device for solving the above problems is a drilling device for drilling an object to be drilled using a core drill having a core bit, wherein a plurality of first tips are arranged on the circumference of a cylindrical body on the drilling direction side. and a center drill arranged at the center of the cylindrical body and having a tip protruding from the first tip in the drilling direction, and drilling the surface of the drilling object with the center drill. a first core bit forming a guide groove; and a second chip portion that can be arranged in the guide groove and that includes a plurality of second chips arranged on the circumference of the cylindrical body on the drilling direction side; A second core bit for inserting a second chip into the guide groove and drilling the hole is provided.

ADVANTAGE OF THE INVENTION According to this invention, it can perforate efficiently.

It is a front view which shows drilling by the 1st core drill of the drilling apparatus of embodiment. It is a partially enlarged cross-sectional view showing the structure of the tip of the first core drill of the embodiment. It is the perspective view which expanded the center drill of the 1st core drill of embodiment. It is an explanatory view explaining the state before perforation using the 1st core drill of an embodiment. It is an explanatory view explaining the state which is drilling by the center drill of the 1st core drill of an embodiment. It is explanatory drawing explaining the guide groove formed by perforation|drilling using the 1st core drill of embodiment. It is explanatory drawing explaining the state which has arrange|positioned the front-end|tip of the 2nd core drill of the drilling apparatus of embodiment to a guide groove. It is explanatory drawing explaining the state which drilled the concrete with the 2nd core drill of embodiment. It is the perspective view which expanded the center drill of the 1st core drill in the example of a 1st modification. FIG. 11 is an explanatory diagram for explaining a configuration in which air injection nozzles are provided around the center drill of the first core drill in the second modification;

An embodiment embodying a punching method and a punching device will be described below with reference to FIGS. 1 to 8. FIG. In this embodiment, a drilling method and a drilling apparatus for forming a cylindrical hole in a concrete block constituting a reactor building (primary shielding wall) will be described. In this embodiment, the core drill 20 as a drilling device performs drilling by exchanging two different types of first tip portion and second tip portion. The core drill 20 to which the first tip portion is attached is referred to as the first core drill, and the core drill 20 to which the second tip portion is attached is referred to as the second core drill.

In this embodiment, the core drill 20 includes a pole base 21, a pole 22, a drill head 23, and a core bit 25, as shown in FIG. The pole base 21 is fixed to the top surface of the mounting plate 15 . Here, the mounting plate 15 is a plate made of metal such as iron arranged above the concrete member 10 to be drilled. A pole 22 is erected on the pole base 21 . A pinion (not shown) of the slide block 23 s of the drill head 23 is meshed with the rack (not shown) of the pole 22 . By moving the slide block 23s in the extending direction of the pole 22, the drill head 23 can move straight in the drilling direction (downward direction in FIG. 1). This drill head 23 incorporates a motor. Below, the drill head 23 side is called the base end side, and the other side (drilling direction side) is called the tip end side. A core bit 25 provided at the tip of the drill head 23 is rotated by the rotational force of this motor.

The core bit 25 has a substantially cylindrical shape with a closed proximal end. A suction device (not shown) is connected to the proximal end of the core bit 25 via a discharge tube. This suction device sucks chips generated during drilling and discharges them to the outside from the core bit 25 .

The core bit 25 includes a mounting portion 25a, a tubular portion 25t and a first tip portion 30. As shown in FIG. The mounting portion 25a is formed so as to protrude toward the proximal side at the center of the closed surface of the core bit 25 on the proximal side. The attachment portion 25 a is attached to the rotating shaft of the motor of the drill head 23 . A cylindrical portion 25t is integrally fixed to the mounting portion 25a. In this embodiment, the length L1 of the tubular portion 25t is 4 m to 6 m.

As shown in FIG. 2 , a first tip portion 30 is provided on the tip side of the core bit 25 . Specifically, the tubular portion 25t of the core bit 25 and the first tip portion 30 are screwed together so that the outer peripheral surface of the tubular portion 25t and the outer peripheral surface of the first tip portion 30 are flush with each other.

(Structure of first chip portion 30)
The first tip portion 30 has a substantially cylindrical shape and can be removed from the tubular portion 25t of the core bit 25 and replaced. A plurality of tips 31 are spaced apart from each other on the lower surface (on the circumference) of the tip portion of the cylindrical body of the first tip portion 30 . In this embodiment, each tip 31 is a diamond tip obtained by sintering artificial diamond with metal, and has a columnar shape with an arc cross section. Each chip 31 is configured by radially overlapping a first blade portion and a second blade portion having the same thickness and joining them integrally. The second blade portion is located on the outer peripheral side of the first blade portion. The cutting edge of the first blade portion is configured in a shape that protrudes further toward the distal end than the second blade portion.

A circular mounting plate 32 is fixed to the proximal end of the first tip portion 30 . The mounting plate 32 is formed with a plurality of discharge holes 32h. Chips in the first chip portion 30 are discharged to the cylindrical portion 25t through the discharge hole 32h.

A center drill 35 is fixed to the mounting plate 32 by a plurality of fasteners (not shown) such as screws. The center drill 35 has a support portion 36 and a drill bit portion 37 .
A support portion 36 of the center drill 35 protrudes forward from the mounting plate 32 . The support portion 36 supports a drill bit portion 37 protruding in the distal direction.

As shown in FIG. 3, the support portion 36 is a block having a thick cylindrical shape with a central through hole 36h. The proximal end portion of the drill bit portion 37 is inserted into the through hole 36h and fixed by welding.

As shown in FIG. 2, the support portion 36 supports the drill edge portion 37 so that the length DL1 of the drill edge portion 37 projecting from the tip of the support portion 36 is 70 mm or less. Here, the drill edge portion 37 is arranged so that the central axis of the drill edge portion 37 coincides with the central axis C<b>1 of the first tip portion 30 . A plurality of blades are spirally formed in the drill blade portion 37 of the present embodiment, and grooves 37g are provided therebetween. For this drill bit portion 37, for example, a cemented carbide drill used for a commercially available impact (hammer) drill having a diameter of 20 mm or more is used. Here, a drill bit portion 37 having a diameter D1 of 24 mm is used. In this embodiment, the length DL1 of the drill bit portion 37 is determined according to the depth of the guide groove to be formed. Here, for example, it is about 63 mm. The tip of the drill bit portion 37 protrudes from the tip of the tip 31 by a length h1 (=about 10 mm) toward the tip side.

(Second chip portion 40)
Further, as shown in FIG. 7, the second tip portion 40 is attached to the tip of the core bit 25 of the core drill 20 of the present embodiment and used. The second tip portion 40 is attached by removing the first tip portion 30 attached to the tip of the core bit 25 and screwing it instead. When attached, the outer peripheral surface of the second tip portion 40 is flush with the outer peripheral surface of the cylindrical portion 25t.

The second tip portion 40 has the same configuration as the first tip portion 30 except that the mounting plate 32 and the center drill 35 are removed. Specifically, the second tip portion 40 has a cylindrical body of the same diameter as the first tip portion 30, with a plurality of spaced apart tips 31 at the distal end of the cylindrical body.

(Drilling method)
Next, a drilling method for forming a through-hole in the concrete member 10 using the above-described core drill 20 will be described with reference to FIGS. 4 to 8. FIG.

First, the core drill 20 having the first tip portion 30 attached to its tip is arranged above the concrete member 10 forming the through hole.
In this case, as shown in FIG. 4, the first tip portion 30 is arranged directly above the upper surface (surface) of the concrete member 10 at the position where the hole is to be formed.

Then, the core drill 20 is lowered while being rotated. In this case, the suction device is driven.
After that, as shown in FIG. 5 , first, the tip of the drill edge portion 37 of the first tip portion 30 comes into contact with the concrete member 10 . In this case, the drill bit 37 drills the concrete member 10 . The chips of the scraped concrete member 10 are discharged to the suction device through the groove 37g of the drill bit portion 37, the discharge hole 32h of the mounting plate 32, the cylindrical portion 25t and the discharge pipe.

The center position of the first tip portion 30 with respect to the concrete member 10 is fixed by drilling the concrete member 10 with the drill blade portion 37 .
By lowering the core drill 20 while the center position of the first tip portion 30 is fixed by the drill edge portion 37 , the plurality of tips 31 of the first tip portion 30 drill the concrete member 10 .
Then, as shown in FIG. 1, the tip 31 of the first tip portion 30 drills a hole from the surface of the concrete member 10 to a depth of about 25 to 60 mm (eg, 40 mm).

Next, rotation of the core drill 20 is stopped and the core drill 20 is pulled upward.
In this case, as shown in FIG. 6, the concrete member 10 is formed with a substantially cylindrical hole Gh1 formed by the center drill 35 and a substantially ring-shaped guide groove Gt1 formed by the tip 31. As shown in FIG.

Next, the first tip portion 30 at the tip of the core bit 25 of the core drill 20 is replaced with the second tip portion 40 .
Next, as shown in FIG. 7, the core drill 20 is lowered to insert the tip 31 at the tip of the second tip portion 40 into the guide groove Gt1.

Next, while driving the suction device, the core drill 20 is lowered while being rotated. As a result, the core drill 20 is used to drill deeper than the guide groove Gt1.
Then, as shown in FIG. 8, the concrete member 10 is penetrated by the core bit 25 . After that, a cylindrical through-hole is formed in the concrete member 10 by pulling up the core drill 20 .

(action)
A concrete member 10 is drilled using a core drill 20 having a first tip portion 30 with a protruding center drill 35 . As a result, the center position of the first tip portion 30 is positioned and held in the concrete member 10 by the drilling of the drill blade portion 37 of the center drill 35 before the drilling by the first tip portion 30 . In this state, since the tip 31 of the first tip portion 30 is used to perform the drilling, the deflection of the core bit 25 is suppressed, and the guide groove Gt1 can be efficiently formed.

According to this embodiment, the following effects can be obtained.
(1) In this embodiment, after the first tip portion 30 is bored in the concrete member 10 by the center drill 35, the tip 31 of the first tip portion 30 forms the guide groove Gt1. As a result, when drilling with the chip 31, it is positioned by the drill edge portion 37 of the center drill 35, so that the desired guide groove Gt1 can be formed. Since the tip 31 of the second tip portion 40 is inserted into the guide groove Gt1 for drilling, even the core bit 25 having a long cylindrical portion 25t can be drilled smoothly at an accurate position. can be done.

(2) In the present embodiment, the center drill 35 is fixed by welding the drill edge portion 37 to the tip of the support portion 36 fixed to the mounting plate 32 welded to the first tip portion 30 . As a result, the length DL1 of the drill edge portion 37 from the fixed support portion 36 can be shortened, so that bending deformation of the drill edge portion 37 can be suppressed even if the concrete member 10 is hard.

(3) In the present embodiment, the drill bit portion 37 of the center drill 35 has a plurality of helical blades, and a groove 37g is provided therebetween. As a result, chips generated by drilling can be moved from the cutting edge to the base end side and discharged along each groove 37g.

This embodiment can be implemented with the following modifications. This embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.
- In the above-described embodiment, the first tip portion 30 forming the guide groove Gt1 includes the drill edge portion 37 in which the blade and the groove 37g are spirally formed. The center drill is not limited to the configuration having the helical blade and the groove 37g.

For example, the center drill 55 shown in FIG. 9 may be fixed to the mounting plate 32 of the first tip portion 30. As shown in FIG. This center drill 55 has a support portion 36 and a drill bit portion 57 . The drill blade portion 57 has a plurality of blades 57b at its tip radially outward from the center. Further, a discharge hole 57h is provided between the blades 57b for discharging chips generated by the drilling. In this center drill 55 as well, since the drill bit portion 57 is fixed via the support portion 36, the length from the support portion 36 to the tip of the drill bit portion 57 is shortened, thereby suppressing the bending deformation of the drill bit portion 57. can do.

In the above-described embodiment, the suction device connected to the base end of the core bit 25 through the exhaust pipe was used to discharge the shavings generated by the drilling from the inside of the core bit 25 . In addition to this, an air injection section for blowing off adhering swarf at the center nozzle of the core bit 25 may be provided.

For example, as shown in FIG. 10 , the center nozzle 61 has a stepped support portion 62 and a drill bit portion 37 . A nozzle 63 is provided at the large diameter portion of the support portion 62 . The tip of this nozzle 63 is directed to the tip of the drill bit portion 37 . Furthermore, the support portion 62 is fixed to the third chip portion 60 via the mounting plate 32 . A mounting member 64 for supplying air to the nozzle 63 is provided at the center of the mounting plate 32 . A hose 65 connected to an air supply device is connected to the mounting member 64 . When the drill bit portion 37 of the center nozzle 61 is drilling, air is injected from the air supply device to the tip of the drill bit portion 37 through the hose 65, the mounting member 64, the support portion 62 and the nozzle 63. be done. As a result, it is possible to perform drilling while blowing off chips adhering to the drill bit portion 37 .

- In the above-described embodiment, the core bit 25 replaces the first tip portion 30 forming the guide groove Gt1 and the second tip portion 40 arranged in the guide groove Gt1 for boring. A first core drill having a first core bit to which the first tip portion 30 is attached and a second core drill having a second core bit to which the second tip portion 40 is attached may be configured separately. In this case, a moving mechanism for moving the first core drill and the second core drill is further provided in order to arrange the second tip portion of the second core drill in the guide groove. After forming the guide groove by the first core drill, the moving mechanism moves the first and second core drills. Next, after arranging the second tip portion of the second core drill in the guide groove by using this moving mechanism, the second core drill is operated to perform drilling. Therefore, when drilling with the second core drill, it is possible to form guide grooves in other locations with the first core drill, so that holes can be formed continuously.

- In the above embodiment, the second tip portion 40 has the same shape as the first tip portion 30 except for the mounting plate 32 and the center drill 35 that form the guide groove Gt1. The tip 31 of the second tip portion 40 for drilling may not have the same shape as the tip 31 of the first tip portion 30 as long as it has a shape that can be arranged in the guide groove Gt1. For example, it may be a tip having the same diameter as the tip 31 of the first tip portion 30 but with a narrow blade thickness.

- In the above embodiment, the core drill 20 is arranged above the concrete member 10 and the hole is formed from the upper surface of the concrete member 10 . Drilling using a core drill is not limited to forming a through hole from the top surface, and for example, a through hole may be formed horizontally from the side surface of concrete.

- In the above embodiment, the concrete member 10 is drilled using the long core bit 25 . The drilling target to be drilled is not limited to the concrete member 10, and can be used when drilling other hard materials such as metal blocks using a long core bit.

Next, technical ideas that can be grasped from the above embodiment and another example will be added below.
(a) The second core bit has a tip of the same shape and size as the tip of the first core bit, and drills a hole having the same diameter as that of the guide groove. 2. A perforating device according to claim 1.

(b) The first core bit and the second core bit are provided with a bit having a plurality of blade portions with different lengths in a radial direction. A perforating device according to (a).

C1... central axis, D1... diameter, L1, DL1, h1... length, Gh1... hole, Gt1... guide groove, 10... concrete member, 15, 32... mounting plate, 20... core drill, 21... pole base, 22... Pole 23 Drill head 23s Slide block 25 Core bit 25a Mounting part 25t Cylindrical part 30 First tip part 31 Tip 32h, 57h Discharge hole 35, 55 Center Drill 36, 62 Support portion 36h Through hole 37, 57 Drill blade 37g Groove 40 Second tip portion 60 Third tip portion 61 Center nozzle 63 Nozzle 64 ... Mounting member, 65 ... Hose.

Claims (5)

A drilling method for forming a hole in an object to be drilled using a core drill equipped with a core bit,
A first comprising: a plurality of first tips arranged on the circumference of a cylindrical body on the drilling direction side; and a center drill arranged in the center of the cylindrical body and having a tip protruding from the first tip in the drilling direction. forming a guide groove while drilling the surface of the object to be drilled with the center drill using the first core bit to which the tip portion is attached;
A drilling method comprising inserting a second core bit having a plurality of second chips mounted on a circumference of a cylindrical body on the drilling direction side into the guide groove to drill the hole. A drilling device for drilling an object to be drilled using a core drill equipped with a core bit,
The core bit is
a plurality of first tips arranged on the circumference of a cylindrical body on the drilling direction side; and a center drill arranged in the center of the cylindrical body and having a tip protruding from the first tip in the drilling direction, wherein the drilling a first tip portion that forms a guide groove while drilling a surface of an object with the center drill;
It can be arranged in the guide groove and can be attached by exchanging with a second tip portion provided with a plurality of second tips arranged on the circumference of the cylindrical body on the drilling direction side. perforator. A drilling device for drilling an object to be drilled using a core drill equipped with a core bit,
A first comprising: a plurality of first tips arranged on the circumference of a cylindrical body on the drilling direction side; and a center drill arranged in the center of the cylindrical body and having a tip protruding from the first tip in the drilling direction. a first core bit having a tip attached thereto and forming a guide groove while drilling the surface of the object to be drilled with the center drill;
A second chip portion is attached which can be arranged in the guide groove and has a plurality of second chips arranged on the circumference of the cylindrical body on the drilling direction side, and the second chips are inserted into the guide groove. and a second core bit for drilling. further comprising a movement mechanism for holding a first core drill provided with the first core bit and a second core drill provided with the second core bit,
4. The drilling device according to claim 3, wherein the moving mechanism places the tip of the second core bit in the guide groove drilled by the first core bit. 4. The center drill comprises a support portion fixed to a mounting plate provided inside the first tip portion and protruding toward the front end, and a drill bit portion fixed to the support portion. The punching device according to any one of 2 to 4.

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