JP2002225025A - Core drill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a core drill which can surely discharge a core in a core bit without pulling out the core bit from a concrete structure, etc., when perforation to the concrete structure, etc., is finished. SOLUTION: An axial hole 28 with the same diameter as the inner diameter of the core bit 27 is formed on a shaft 25 on which the core bit 27 is fitted and is communicated with the core bit 27 to discharge the core in the core bit through the shaft 25 by a successive gelidium jelly pushing-out style.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a core drill used for drilling holes in a concrete structure or the like.

[0002]

2. Description of the Related Art FIG. 1 shows a conventional core drill of this kind, which includes a base 1 detachably fixed to a concrete structure C, a column 3 rising from the base 1 and having a rack 2 attached thereto, and a rack. 2 is mounted on the column 3 so as to be able to move up and down, and the pinion is removably attached to the head 4 sent along the column 3 by rotating the pinion by turning the handle 7. 8 and the head bit 4
The core bit 5 is attached to the shaft 12
And a motor 6 for rotationally driving the motor.

When drilling a hole in a concrete structure, for example, a wall surface using such a core drill, the base 1 is fixed to the wall surface using an anchor bolt (not shown), and then the motor 6 is started to rotate the core bit 5 to rotate the handle. The diamond bit 8 at the tip of the core bit is pressed against the wall surface by an operation to perform drilling. When the drilling is completed, the surrounding concrete structure 10 and the core 9 which is cut off remain in the core bit 5 as shown in FIG. As shown in FIG. 3, when forming a deep hole, the core 11 is broken by the vibration at the time of drilling and its own weight, the core bit is retracted by operating the handle, and the core 9 or 11 remains in the core bit when the core bit is pulled out from the drilled hole. Occasionally it will be taken out. To remove this core, the core bit 5 must be removed from the shaft 12. The same applies when a hole is drilled from below in the ceiling of a concrete structure.

Japanese Unexamined Patent Publication No. 10-249849 proposes a structure in which a window is provided on the peripheral side of a core bit so that the core can be discharged from the window in order to solve the above problem.

[0005]

In a concrete structure or the like, a large number of continuous or intermittent holes must be formed in a straight line or a circle. It is possible to travel on a rail fixed and mounted on the rail, etc., move it on the rail by a fixed amount and fix it to the rail with a clamp, etc., or rotate the base by a fixed amount around the mounting axis on the concrete structure etc. A drilling operation is being performed.

If only one hole is made in a concrete structure or the like, it is extremely troublesome to remove the core bit and remove the core inside when the core drill is removed from the concrete structure or the like after the completion of the drilling. But not
When a large number of holes are made as described above, it is troublesome to remove the core bit and discharge the core every time the holes are made.

[0007] In particular, when a drilling operation on a concrete structure is performed by a remote control without an operator at the site, or when it is intended to automatically perform the operation by a control device, it is easy to remove the core bit and discharge the core. Not.

According to the core bit disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 10-249849, a core that has penetrated deeply into the core bit hits a slope in the core bit and is subjected to a bending force, so that a crack is formed and a hole is formed. Simply pulling out the core bit and tapping it will cause the core to collapse and fall out of the window, and the core can be ejected without removing or disassembling the core bit.However, if the core is not long enough to reach the slope, the core If the core does not drop because it is caught by the window, or if the core is too long and longer than the window, it will be supported by the window, making it difficult to come out.The window will reduce the strength of the core bit. However, there are difficulties such as the inability to discharge the core.

An object of the present invention is to provide a core drill capable of solving the above-mentioned problems.

[0010]

The present invention relates to a support, a head slidably mounted on the support, a feed device for moving the head forward and backward along the support, a shaft rotatably supported by the head, and the shaft. In the core drill consisting of a motor that rotationally drives and a core bit that is detachably attached to the shaft, the core bit has a cylindrical shape with both ends opened, and the shaft has a diameter equal to or larger than the inner diameter of the core bit. It has a shaft hole and communicates with the core bit,
The core which is cut off or broken off from the surrounding concrete structure or the like is discharged from the core bit through the shaft.

According to the present invention, the core bit has the same strength as the conventional one, and the core can be sequentially extruded regardless of the length and without removing the core bit from the hole. The core is slid down by its own weight and is discharged when a hole is made up and down, even when a hole is made in the ceiling or a side wall.

The feeder used in the present invention comprises, for example, a pinion which is rotated by a turning operation of a handle and a rack attached to a support, as in the case of the conventional one, and the pinion is remote-controlled or A motor driven by a motor controlled by a control device is exemplified.

[0013]

FIG. 4 shows a head 21 of a core drill.
A shaft 25 rotatably supported by a bearing 22 and rotationally driven by a motor 23 via a gear transmission mechanism 24 has a diamond tip 2
6, a shaft hole 28 is formed in the shaft by being screwed from the outside and connected thereto, communicating with the core bit 27 and having the same diameter as the inner diameter of the core bit 27.

The shaft 25 also has an axial water hole 29.
Are formed at regular intervals in the circumferential direction at three locations, and each water hole 29 is formed in the circumferential direction on the shaft 25 by the shaft sealing device 31, opens in the circumferential groove 32 forming a water swivel, and is cooled by the cock 33. Water is passed through each water hole 29 from the circumferential groove 32.

The core bit 27 has a double-pipe structure, and has an axial groove in one of the inner pipe 27a and the outer pipe 27b, so that water holes 34 are formed at three places.
It is formed in the axial direction. Further, a circumferential groove 35 is formed on the surface joined to the end of the shaft, and each water hole 34 is formed so as to open at the bottom of the circumferential groove. Is composed. As a result, the cooling water passed through the water hole 29 is passed through the water hole 34 via the circumferential groove 35, flows out of the opening between the diamond chips 26, discharges cutting chips at the perforated portion, and cools the core bit 27. It has become.

The core drill according to the present embodiment is constructed as described above. After the drilling is completed, the core bit 27 is extracted from the drilled hole, and then the core is inserted. Core is pressed by the core formed at the time of drilling. When such a drilling operation is repeated, the core is pushed out from the shaft 25 in a tocoro manner and discharged,
No work is required to discharge the core.

[0017]

According to the present invention, the core can be reliably ejected regardless of its length by extruding the core in a tocoro-type manner at the time of drilling. When drilling a hole in the ceiling, it will slide down by its own weight and be discharged, so there is no need to remove the core bit from the hole to discharge the core, it is not necessary to remove the core drill one by one, compared to a core bit with a window. This has the effect that the strength is not impaired.

[Brief description of the drawings]

FIG. 1 is a front view of a conventional core drill.

FIG. 2 is a cross-sectional view of a core bit at the end of drilling.

FIG. 3 is a cross-sectional view of the core bit when a deep hole is formed.

FIG. 4 is a partial cross-sectional view of a main part of a core drill according to the present invention.

[Explanation of symbols]

 21, head 22, bearing 23, motor 24, gear transmission mechanism 25, shaft 26, diamond tip 27, core bit 28, shaft hole 29, 34, water hole 31, shaft sealing device 32, 35 ・ ・ Circumferential groove 33 ・ ・ Cook

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroyuki Matsubara 4-6-8 Nishi-ku Commerce Center, Hiroshima-shi F-term in Consec, Inc. (reference) 3C069 AA04 BA09 BB01 BB03 BC02 CA10 DA07 EA01

Claims (1)

[Claims] 1. A support, a head slidably mounted on the support, a feed device for moving the head forward and backward along the support, a shaft rotatably supported by the head, and a motor for rotating the shaft. And, in a core drill consisting of a core bit detachably attached to the shaft, the core bit has a cylindrical shape with both ends opened,
The shaft has an axial hole having a diameter equal to or larger than the inner diameter of the core bit and communicates with the core bit, and a core cut off or broken off from the surrounding concrete structure or the like is discharged through the shaft from the core bit. Core drill characterized in that it is made to.