JPH09119281A - Bending type wing bit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify structure by dividing a wing bit blade into a root blade on the casing side and an end blade on the outside in the radial direction and connecting the end blade to the root blade in a downward bendable manner. SOLUTION: An arm 14 extended to the root blade 11 side is installed onto the top face of an end blade 12, and a balance weight 17 is borne on the root blade 11 side of the arm 14 while a place on the radial direction is adjusted freely. A liner 5 is set in parallel as excavation progresses, and the radius of the liner 5 is formed in size slightly smaller than the radius of a wing bit blade 10. The end blade 12 is abutted against the lower end section of the liner 5 when a casing 1 is drawn up after excavation is completed, restraint by the liner 5 is made larger than the vertical force of the weight 17 and the end blade 12 is bent downwards when the casing 1 is further pulled up from the state, the radius R2 of the blade 10 under this state is made smaller than the inside diameter of the liner S, and the blade 10 can be drawn up. Accordingly, power for shrinkage is unnecessitated, and structure can be simplified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a folding wing bit for drilling vertical holes when constructing various standing piles, foundation piles, landslide prevention piles, etc. in the ground.

[0002]

2. Description of the Related Art Conventionally, when drilling a vertical hole in the ground, basically, a circular hole having the same diameter is drilled both above and below. However, in concrete cast-in-place piles, in order to reduce the amount of excavated soil and the amount of concrete, bottom-expanded piles that expand the bottom and increase the bearing capacity of the piles are used particularly in construction work. Most of the excavation methods are a reverse circulation drill method or an earth drill method.

In the former case, the scrap excavated by a wing bit is discharged together with water through a drill pipe by a pump for pumping muddy water or an air lift. In the latter, the geriver that expands and contracts the rotational force of the rotating device on the ground conveys it to the bucket, takes in the earth and sand, compresses the geriver and discharges it to the ground.

[0004]

The conventional reverse circulation drill system requires a muddy water treatment facility for treating water and the waste discharged together with the water, and is not suitable for hard ground or boulder layers.

On the other hand, also in the earth drill method, since the excavation work and the earth and sand discharge work are alternately performed, the work efficiency deteriorates as the depth increases. Further, since the excavation is carried out on the entire cross section using the bucket, the harder the ground, the larger the rotational torque and the pushing force required. However, because of the strength of the geriva, it is not suitable for deep and hard ground.

Therefore, the deep foundation method of manually excavating work has been conventionally used, but there is a problem that it is dangerous and the excavation efficiency is poor.

In the reverse circulation drill system, a power source (hydraulic cylinder, etc.) for contracting the wing bit and peripheral equipment (hydraulic hose, hydraulic power source, etc.) necessary for the power source are required, and the device is large. It is made heavy and heavy.

Further, the structure is complicated, and it cannot be used under the circulation submerged in water.

An object of the present invention is to provide a folding wing bit which does not require a power source for contraction and has a simple structure.

[0010]

According to the present invention, a plurality of wing bit blades mounted radially on a casing are divided into a root blade on the casing side and a tip blade on the outer side in the radial direction, The tip wing is foldably connected downward to the root wing, an arm extending toward the root wing is attached to the upper surface of the tip wing, and a balance weight is supported on the root wing side of the arm so that the position in the radial direction is adjustable. ing.

During drilling, a liner having a diameter slightly smaller than the outer diameter of the wing bit is set as the drilling progresses. After the drilling is completed or when the drilling is interrupted and the diameter expansion device including the wing bit is recovered, the casing is pulled up in sequence,
The tip wing abuts the lower end of the liner. Further, when the casing is pulled up, the restraining force of the liner exceeds the vertical force of the balance weight, the tip blade is bent downward, the outer diameter of the wing bit blade becomes smaller than the inner diameter of the liner, and the diameter expanding device can be pulled up.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2, a plurality of misalignment inlets 2 are formed in the lower portion of a cylindrical casing 1, and a plurality (three in the illustrated example) are provided in the vicinity of the inlets 2. Is attached with a wing bit wing indicated generally by 10.

Referring also to FIG. 3, this wing bit wing 1
0 is divided into a root blade 11 on the casing 1 side and a tip blade 12 on the outer side in the radial direction. Both blades 11 and 12 can be bent downwardly with respect to the root blade 11 by a pair of hinges 13. It is connected. A pair of arms 14 extending toward the root blade 11 is attached to the upper surface of the tip blade 12.

The root 14 side of the arm 14 is formed in a forked portion 15, and the forked portion 15 is formed with a pair of elongated holes 16 in the longitudinal direction. A rectangular parallelepiped balance weight 17 is slidably housed inside the bifurcated portion 15, and bolts and nuts 18 protruding from both sides are provided.
By this, the position on the root wing 11 can be adjusted. The adjustment range is the balance weight 1 in FIG.
7 is most outward in the radial direction as shown by the chain line, and the weight of the balance weight 17 and the tip blade 12 causes the tip blade 1 to move.
From the position where 2 is bent downward as shown by the chain line, as shown by the solid line, the balance weight 17 is located at the innermost side in the radial direction, and the weight of the balance weight 17 causes the tip blade 12 to move.
Is up to the position where it is held horizontally. In addition,
The balance weight 17 on the outermost side in the radial direction is previously fixed to a predetermined position with a bolt and a nut 18,
It can be moved manually if necessary.

Next, a mode of drilling will be described. (1) Before starting excavation, the balance weight 17 is adjusted and attached to a position on the root wing 11 suitable for the work content. (2) The liner 5 is set in parallel with the progress of excavation (FIG. 4). The radius R of the liner 5 is slightly smaller than the radius R1 of the wing bit blade 10. The liner 5 is often a spiral type. (3) When the excavation is completed, or when, for example, the wing bit blade 10 is repaired or replaced, the casing 1 is pulled up. Then, the tip of the wing bit blade 10, that is, the tip of the tip blade 12 contacts the lower end of the liner 5.

(4) From that state, the casing 1 is further
When the is pulled up, the restraining force of the liner 5 becomes larger than the vertical force of the balance weight 17, and the tip blade 12 bends downward as shown in FIG. (5) Therefore, the wing bit wing 10 in this state
Radius R2 (FIG. 2) becomes smaller than the inner diameter D of the liner 5, and the wing bit blade 10 can be lifted. (6) When the casing 1 has been pulled up and the casing 1 is to be reinserted into the liner 5, the balance weight 17 is positioned at the outermost position in the radial direction and is lowered in the state shown in FIG. When the wing bit blade 10 reaches the ground E to be excavated below the lower end of the liner 5, the tip blade 12
Is returned to the horizontal excavation position and held there.

The mounting position of the balance weight is preferably changed according to the ground to be excavated.

That is, as illustrated in the above embodiment,
When the ground E to be excavated has sufficient strength to support the tip wing 12, the balance weight 17 is attached to a position where the balance weight 17 bends downward when the tip wing 12 is not restrained.

Therefore, in excavation work, the tip blade 1
Since the excavated ground E is located below 2, the tip blade 12 is excavated in a horizontal state as shown in FIG. After the excavation work is completed or the work is interrupted, the wing bit wing 10
When the casing 1 is pulled up, the tip blades 12 come into contact with the liner 5 and are bent.

If the ground E to be excavated is not strong enough to support the tip wing 12, the balance weight 17 is adjusted to a position where the tip wing 12 is in a horizontal state without being restrained. In this case, the tip blades 12 come into contact with the liner 5 during the pulling up, so that the blades are bent.

By thus changing the position of the balance weight depending on the ground to be excavated, the reaction force exerted on the liner 5 can be minimized and the influence can be minimized.

Further, it is preferable that some balance weights having different weights are prepared in advance and an optimum balance weight is attached according to the ground.

[0024]

As described above, according to the present invention, the tip blade is expanded during excavation work, and the tip blade is bent by engaging with the liner when it is pulled up. It becomes completely unnecessary. Therefore, the entire device can be simplified. In particular, it is safe because a person does not work inside the hole, and is particularly suitable for a hole filled with muddy water. Since the device itself is simplified and is lightweight, the lifting machine can be downsized and the required installation area can be downsized.

[Brief description of the drawings]

FIG. 1 is a top view showing an embodiment of the present invention.

FIG. 2 is a partial side view of FIG.

FIG. 3 is a perspective view of FIG. 2;

FIG. 4 is a side view illustrating a state of excavation.

FIG. 5 is a side view showing a state in which the tip blade starts to bend.

[Explanation of symbols]

 R ... Inner diameter of liner R1 ... Radius of wing bit blade R2 ... Radius of wing bit blade with tip blade bent 1 ... Casing 2 ... Sliding inlet 5 ... Liner 10・ ・ ・ Wing bit wing 11 ・ ・ ・ Root wing 12 ・ ・ ・ Tip wing 13 ・ ・ ・ Hinge 14 ・ ・ ・ Arm 15 ・ ・ ・ Bifurcated portion 16 ・ ・ ・ Long hole 17 ・ ・ ・ Balance weight 18 ・ ・・ Bolts and nuts

Claims (1)

[Claims] 1. A plurality of wing bit blades radially attached to a casing are divided into a root blade on the casing side and a tip blade radially outward, and the tip blade is located below the root blade. In addition to being flexibly connected to
A bendable wing bit in which an arm extending toward the root blade is attached to the upper surface of the tip blade, and a balance weight is supported on the root blade side of the arm so that the position in the radial direction can be adjusted.