JP3088981B2 - Drilling agitator with anti-corotating wings - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an excavating and stirring apparatus having anti-rotating wings which is used in a ground improvement method such as a deep mixing method and prevents the excavated soil from rotating with an excavating wing or a stirring wing. .

[0002]

2. Description of the Related Art A viscous ground is stirred and mixed with a solidified material such as cement by using a drilling and stirring device having a stirring blade protruding from the outer periphery of a drilling rod having a drilling blade at the tip. In order to prevent the excavated viscous soil from adhering to the excavation wings and agitating wings and rotating together with the digging and agitating device when the ground is improved, the applicant has proposed an anti-corotating wing longer than the excavation diameter. A co-rotation prevention device that is loosely fitted around the outer periphery of a drill rod has been proposed (Japanese Patent No. 1197295).

The tip of the co-rotation prevention blade is inserted into the ground around the excavated ground, so that the excavated soil is forcibly cut even when the excavated rod is rotated by the resistance of the ground. Although it is possible to obtain a good mixing state, the outer peripheral surface of the digging rod is worn due to friction caused by contact with the inner peripheral surface of the boss loosely fitted to the digging rod because it rotates relatively to the digging rod. There's a problem. The wear is promoted by the earth and sand entering the gap between the inner peripheral surface of the boss and the outer peripheral surface of the excavating rod.

When the anti-corotating wing is worn, it can be easily replaced. However, when the digging rod is worn, partial replacement is not effective. Further, since the drilling rod bears a torsional moment over its entire length, the drilling rod may break if the wear of the drilling rod progresses.

The present invention proposes an apparatus for suppressing the wear of a drill rod and extending the life of the drill rod.

In the present invention, the surface of the outer periphery of the excavating rod, on which the boss is loosely fitted, is welded to form a point or a line by welding, and the surface of the excavating rod and the inner peripheral surface of the boss are kept in a non-contact state. Protects the surface of the drill rod, reduces wear,
Or prevent.

The boss is provided so as to protrude above and below a portion where the boss is loosely fitted, and also contacts the flange of the excavating rod, which restrains the vertical movement of the boss. By applying the weld overlay on the boss side surface as well, the flange is protected in the same manner as the drill rod body, so that the life of the drill rod itself is extended.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 2, the present invention uses a boss 3 which has a drilling wing 7 at its tip and has a stirring wing 8 protruding on its outer periphery, and which is loosely fitted on the outer periphery of a drilling rod 2. In the excavating and stirring device 1 equipped with the co-rotation-preventing wings 4, as shown in FIG. 1, the surface of the outer periphery of the excavating rod 2 where the boss 3 is loosely fitted is overlaid by welding.

As shown in FIG. 3A, the boss 3 is mounted on the outer periphery of the digging rod 2 with a gap between the boss 3 and the outer peripheral surface of the digging rod 2 which can be relatively rotated. The boss 3 is detachably attached to the excavation rod 2 for replacement when its inner peripheral surface is worn or for checking the state of the build-up 5 on the outer periphery of the excavation rod 2.

In FIG. 3A, the boss 3 is formed by curving the anti-corotating wing 4 located on one side with respect to the center of the excavating rod 2 toward the excavating rod 2, and the anti-corotating wing 4 is integrated. The bosses 3 and 3 are arranged around the excavating rod 2 in a state where they face each other, and the boss 3 and the co-rotation prevention wing 4 are detachably attached to the outer periphery of the excavating rod 2 by sandwiching the excavating rod 2 and joining them together. ing.

The number of anti-corotating blades 4 is not limited.
Three or four corotation prevention wings 4 may be installed in the same manner as in-(a).
The co-rotation preventing blades 4 may be provided by welding or the like on the center line indicated by the one-dot chain line of the bosses 3 and 3.

Flanges 6 and 6 for restricting the vertical movement of the boss 3 are provided above and below the portion of the outer periphery of the excavating rod 2 where the boss 3 is loosely fitted.
The overlay 5 is welded to the section between the upper and lower flanges 6 and 6 as shown in FIGS. FIGS. 1 and 3 show a case where the bead of the overlay 5 is directed in the axial direction of the drilling rod 2 and FIG. 4 is attached in a direction perpendicular thereto, and the drawings show a case where the overlay 5 is welded linearly. 3
It is sufficient that a gap is always provided between the inner peripheral surface of the drilling rod 2 and the outer peripheral surface of the excavating rod 2.

When the overlay 5 is linearly formed, the overlay 5 is not only linear but also has a waveform as shown in view of welding workability. Since overlay welding is performed with the excavating rod 2 laid horizontally, it is efficient to attach the excavating rod 2 in the axial direction of the excavating rod 2 when attaching the excavating rod 2 in a straight line.

The welding rod used for the overlay 5 is preferably as hard as possible to reduce wear. For example, HK800K is used. The height of the padding 5 is determined by the size of the gap between the excavating rod 2 and the boss 3, and is suitably about 3 to 5 mm.

FIG. 5 shows a flange 6 similar to the drill rod 2.
6 also shows a case where a padding 5 is also applied to the surface of each flange 6 on the boss 3 side in order to protect the same.

[0016]

According to the present invention, the surface of the portion of the outer periphery of the excavation rod where the boss is loosely fitted is welded to form a spot or a line by welding, and the excavation is performed to keep the surface of the excavation rod and the inner peripheral surface of the boss in a non-contact state. The surface of the rod is protected, and its wear can be suppressed or prevented.

If the boss is detachably mounted, the wear state of the overlay can be checked. If the wear has progressed, the overlay can be applied again by removing the boss. In the case where is worn, rebuilding is performed again to prevent a situation in which the wear progresses and the drill rod itself is damaged.

In the second aspect, since the flange is also built up on the boss side surface, the flange can be protected as well as the surface of the drilling rod, and the life of the drilling rod can be extended.

[Brief description of the drawings]

FIG. 1 is an elevational view showing a drilling rod with a co-rotation prevention wing removed.

FIG. 2 is an elevational view showing the excavation rod with the co-rotation prevention wing mounted thereon.

FIG. 3 (a) is a cross-sectional view through the upper flange of FIG. 2,
FIG. 2B is an enlarged view of a portion where the anti-corotating wing of FIG. 1 is mounted.

4 is a modified example of FIG. 3, in which (a) is a cross-sectional view passing through an upper flange in FIG. 2, and (b) is an enlarged view of a portion where the co-rotation prevention wing in FIG. 1 is mounted.

FIG. 5 is a perspective view showing a state in which the surface of the excavation rod and the flange are overlaid.

[Explanation of symbols]

1 ... drilling and stirring device, 2 ... drilling rod, 3 ... boss,
4 ... anti-corotating wings, 5 ... overlay, 6 ... flange,
7 ... Excavation wing, 8 ... Stirring wing.

Continuation of the front page (56) References JP-A-7-259504 (JP, A) JP-A-61-171650 (JP, U) JP-B-58-29374 (JP, B2) (58) Fields investigated (Int) .Cl. ⁷ , DB name) E02D 3/12

Claims (2)

(57) [Claims] 1. A drilling / stirring apparatus having a drilling blade at its tip and a counter-rotating wing mounted via a boss which is loosely fitted to the outer circumference of a drilling rod having a stirring blade protruding from the outer circumference thereof. A drilling / stirring apparatus with anti-corotating wings, which has a point-like or linear build-up by welding on the surface of the outer periphery where a boss is loosely fitted. 2. The excavating and stirring apparatus with anti-corotating wings according to claim 1, wherein the outer peripheral surface of the excavating rod is welded to a boss side surface of a flange fixed above and below a portion where the boss is loosely fitted. .