JPH0650090Y2 - Drill bit - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piercing drill used for forming through holes (hereinafter referred to as holes) in reinforced concrete wall surfaces of buildings and concrete structures such as roads, dams, tunnels and bridges. It is a thing.

[0002]

2. Description of the Related Art For example, at a reinforced concrete building construction site, holes for pipes for water, gas, cooling and heating, electric wiring, etc. are formed in the floor and wall surfaces. A portable drilling machine is used for this drilling, and a drilling drill 11 as shown in FIG. 2 is used as the drilling tool.

The piercing drill 11 is a cylindrical metal having an adapter portion 12 for connecting to a rotary shaft of a piercing machine, a circular pipe portion (tube) 13 for relaying, and a blade portion 14 formed at one end. It is composed of a short tube body 15 and a bit section 16, and these sections are separately manufactured, and integrally formed by screwing them together, or all of them are originally formed integrally. The blade 14 is generally made of diamond, cemented carbide tip, hard alloy, or the like.

[0004]

The drilling by the drilling drill 11 having such a structure is performed by circularly drilling by the blade portion 14 formed at the tip of the cylindrical bit portion 16.
At that time, a concrete solid body (hereinafter referred to as a core) in the center portion, which is drilled in an annular shape, enters the drilling drill 11.

Since this core remains in the drilling drill 11 when drilling a horizontal hole, the drilling drill 11 can be pulled out of the hole after drilling and the core can be relatively safely withdrawn, but in the case of a vertical hole or an oblique hole, It is very dangerous because the core may fall out at the same time when the hole penetrates. In particular, at the construction site of the building, separate works may be performed in parallel on the upper floor and the lower floor, and it is very dangerous if the core falls out even if a bottom-up meeting is held before the construction starts. .

The present invention has been made in order to solve the above problems, and its purpose is to prevent the core that has entered the drill from falling out even when drilling vertical holes or oblique holes. It is to provide a drill bit that can be safely drilled without a hole.

[0007]

In order to achieve the above object, a bit of a perforating drill according to the present invention has an L-shaped slit which is substantially vertical from a blade portion to a body portion and substantially horizontal in a rotation direction. In addition, the body portion formed by the slit projects inward.

[0008]

The bit has an L-shaped slit which is substantially vertical from the blade portion toward the body portion and is substantially horizontal in the rotation direction, and the portion of the body portion formed by this slit projects inward. Therefore, the inwardly protruding portion can press the core in the drill after drilling with a spring force and prevent the core from falling out of the drill.

Moreover, since the inwardly projecting portion is formed by a slit which is substantially horizontal in the direction of rotation, during drilling, it rotates on the same circumference as the barrel and the hole penetrates and simultaneously projects inward. Therefore, it can be rotated without any hindrance to the rotation at the time of drilling.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1A and 1B are explanatory views of a bit according to the present invention, in which FIG. 1A is a side view and FIG. 1B is a bottom view.

In the figure, 1 is a bit made of a metal short pipe, 2 is a plurality of blade portions joined to the lower end surface of the bit 1, 3
Is a slit formed in the bit 1 vertically from the blade portion 4, 4 is a slit formed horizontally from the upper end of the slit 3 in the rotation direction of the drill, and 5 is for connection with a relay pipe formed on the upper end side of the bit 1. The external thread part is shown. The rectangular portion 6 of the bit 1 formed by the slits (3, 4) formed in the L shape by the slits 3, 4 is projected inward.

When the bit 1 having such a structure is connected to the intermediate pipe to form a drill as shown in FIG. 2 and a hole is made in the reinforced concrete, the portion 6 protruding inward is the bit 1 during the drilling. The blade portion 2 rotates along the inside of the groove to be excavated, and when the hole penetrates, the groove disappears, so that it simultaneously protrudes inward and presses the outer peripheral surface of the core.

Actually, an L-shaped slit is formed on a bit 1 having an outer diameter of 75 mm and a blade thickness of 5 mm by a vertical slit 3 having a slit width of 3 mm and a length of 35 mm and a horizontal slit 4 having the same width and a length of 75 mm. The portion 6 formed by this L-shaped slit was curved so that the tip thereof protrudes inward by about 8 mm and has a spring force.

When a hole was drilled in a concrete floor having a thickness of 150 mm using this bit, a through hole having a diameter of 75 mm could be drilled without dropping the core.

In the above embodiment, the example in which the portion 6 has a rectangular shape by the vertical and horizontal slits 3 and 4 has been described, but the present invention is not limited to this example, and the slits 3 and 4 are Both the vertical and horizontal inclinations may be up to about 20 °, and the point is that the portion 6 should be formed so as to have a spring force that does not hinder the rotation of the drilling and prevents the core from falling. .

In the above embodiment, an example in which one portion 6 formed by the L-shaped slits (3, 4) is provided has been described, but the present invention is not limited to this example.
A plurality of portions 6 may be provided.

Further, in the above description, the reinforced concrete of a building was described as an example, but it goes without saying that the bit of the drill for drilling of the present invention can be applied to concrete structures such as roads, dams, tunnels and bridges. Yes.

[0018]

As described above, the drill bit of the present invention can be drilled in a concrete floor or wall surface of a building without dropping the core, thus ensuring safety at a construction site.

[Brief description of drawings]

FIG. 1 is an explanatory view of a bit according to the present invention,
(A) is a side view and (b) is a bottom view.

FIG. 2 is an explanatory view of a conventional perforation drill.

[Explanation of symbols]

1: Bit 2: Blade part 3: Vertical slit 4: Horizontal slit 5: Male screw part for connection 6: Rectangular part of bit

Claims (1)

[Scope of utility model registration request] 1. An L-shaped slit is provided substantially vertically from the blade portion to the body portion and further substantially horizontally in the rotation direction,
The bit of the drill for drilling, characterized in that the body part formed by this slit projects inward