JPH11229368A - Ground improving agitating head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain an agitating function by preventing excavated earth and sand from adhering to the periphery of a rod between agitating blades and growing into a lump. SOLUTION: In a ground improving agitating head in which plural steps of agitating blades 4A, 4A are mounted at the lower end of a rod 1 connected to a drive part and freely rotationally hung down, mud-removal plates 5, 5 are turnably mounted on the outer periphery of the rod 1 between the agitating blades 4A, 4A provided in plural steps, and operating pawls 8, 8 which are freely to open apart in response to the resistance of soil produced by the inversion of the rod are provided at the outer ends of the agitating blades. The operating pawls 8, 8 are connected to the mud-removal plates 5, 5 by interlocking mechanisms 10, 10. When the operating pawls 8, 8 are opened apart, the mud-removal plates 5, 5 are turned via the interlocking mechanisms 10, 10 in the direction to leave the rod 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground improvement stirring head for improving excavated ground.

[0002]

2. Description of the Related Art A plurality of vertical stirring blades are attached to a lower end portion of a rod which is connected to an output shaft of a driving unit supported to be able to move up and down along a tower of a working machine and is rotatably driven and suspended. 2. Description of the Related Art A ground improvement stirring head for strengthening the ground by stirring and kneading excavated earth and soil with a soil improving agent (chemical solution) has been generally used.

[0003]

However, in the above-mentioned conventional stirring head, when used on the ground containing a large amount of viscous soil, as shown in FIG. 4, sediment c adheres to the stirring blades b, b of the excavating rod a. Then, the adhered sediment c gradually grows and fills the space between the stirring blades b, b, and finally becomes a dumpling,
Therefore, there is a problem that the mixing and stirring function of the excavated earth and the chemical liquid is lost.

[0004]

SUMMARY OF THE INVENTION According to the present invention, even if excavated earth and sand adhere around the rod between a plurality of stages of agitating blades, the excavated earth and sand is removed in a timely manner in the ground, and the adhered earth and sand is collected between the agitating blades. An object of the present invention is to provide a ground improvement stirring head capable of preventing the growth in a uniform shape and maintaining the stirring function continuously.

[0005] As means for solving the above problems, the present invention provides:
In a ground improvement stirring head in which a plurality of stages of stirring blades are attached to a lower end of a rotatably suspended rod connected to a driving unit, a mud elimination plate is provided on an outer periphery of a rod between the stirring blades provided in the plurality of stages. It is mounted so as to be able to pivot, and an operating claw is provided at the outer end of the agitating blade, which can be expanded by receiving the resistance of the earth and sand by reversing the rod, and the operating claw and the mud removing plate are connected by an interlocking mechanism. When the operating claw is expanded, the mud elimination plate pivots in a direction away from the rod via the interlocking mechanism.

The interlocking mechanism has a simple structure in which a position eccentric to the pivot of the operating claw and a position distant from the pivot of the mud elimination plate are connected by a link. This is a preferred form because it can be tightened.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the drawings. FIG. 1 shows a front view of an embodiment of a stirring head according to the present invention, and FIG. 2 shows a sectional view taken along the line AA of FIG. ing.

The rod 1 is connected at its upper end to a drive unit (not shown), and rotates (forward) in the direction of arrow A during excavation.
Is provided, and a pit is excavated. Inside the pit, a chemical supply path 3 for supplying a chemical such as a ground improvement agent (cement milk) is provided. It is opened at the tip of the part, and discharges a chemical solution into excavated earth and sand.

The rod 1 above the excavating head 2 has
A plurality of agitating blades 4A, 4 at a required interval in the vertical direction
B are projected in the radial direction with a phase difference of 90 ° from each other. As shown in FIG. 2, the stirring blades 4A and 4B are blades having an elongated rectangular planar shape, and the length thereof is substantially equal to the diameter of the digging hole formed by the digging head 2 (digging diameter D). Have been.

Among the stirring blades 4A, 4B, a pair of mud elimination plates 5, 5 are provided on the outer peripheral surface of the rod 1 between the stirring blades (indicated by reference numerals 4A, 4A) having the same phase.

The mud elimination plates 5 and 5 are formed such that the side in contact with the outer peripheral surface of the rod 1 is formed in an arc surface equal to the radius of the outer periphery of the rod 1, and one end thereof is agitating blades 4 A and 4 A of the rod 1. 4A are pivotally supported by shafts 7 and 7 protruding on both sides at positions corresponding to 4A, and the mud removing plates 5 and 5 are separated from the rod 1 around the shafts 7 and 7 in the direction away from the rod 1. It is mounted so that it can pivot.

On the other hand, at the tip of the agitating blades 4A, 4A, the bases of the operating claws 8, 8 are attached by shafts 9, 9 to the tips 8a, 8a.
Is mounted rotatably in a horizontal plane in a direction on the rear side with respect to the rotation direction of the rod 1 at the time of normal rotation. When the operating claws 8, 8 are rotated in a posture perpendicular to the longitudinal direction of the stirring blades 4A, 4A, the drilling diameter D of the drilling hole by the drilling head 2 is increased.
A position (called a withdrawal position) that is retracted further inward and that protrudes outward from the excavation diameter D when the stirring blades 4A, 4A are rotated in such a posture in the longitudinal direction thereof (called a protruded position).
So that the rod 1
Is reversed, the tips 8a, 8a of the operating claws 8, 8 come into contact with the surrounding ground and can be turned into a protruding state by the resistance.

The mud elimination plates 5, 5 and the operating claws 8, 8 are connected to the interlock mechanism 1 at the positions of the upper and lower stirring blades 4A, 4A.
When the operating claws 8, 8 are rotated in the protruding direction due to resistance against the ground, the mud removing plates 5, 5 are pivotally moved in a direction away from the outer peripheral surface of the rod 1. It is supposed to.

In the example shown in the drawing, bearings 11, 11 protruding from the rod 1 side when the operating claws 8, 8 are at the retreat position (the position shown in FIG. 2), and the mud elimination plate 5 , 5
Bearings 12, 1 protruding from the outer surfaces of the free ends 5a, 5a
2, the links 13, 13 are rotatably connected by pins 14, 15, and as the operating claws 8, 8 rotate to the protruding position (the position shown in FIG. 3), the mud removing plates 5, 5 rotate the shaft 7, It is configured to be pivoted about the fulcrum 7 in a direction away from the rod 1.

In the illustrated embodiment, the stirring blade 4
Since there is a stirring blade 4B having a phase difference of 90 ° between A and 4A, a notch 5b for avoiding the intermediate stirring blade 4B from the free ends 5a and 5a of the mud elimination plates 5 and 5 (FIG. 1) is formed.

Next, the working procedure will be described.

The rod 1 is driven to rotate forward by a drive unit (not shown), and the ground is drilled by the excavating head 2 at the lower end thereof. At this time, the chemical solution is supplied through the chemical solution supply passage 3 in the rod 1, and the chemical solution is discharged from the lower end of the excavating head 2 to mix and agitate the excavated earth and sand with the chemical solution by the stirring blades 4A, 4B.

When the ground is a viscous soil, it adheres to a member (stirring blade) protruding outward due to the viscosity of the excavated earth and sand, gradually grows, and ultimately forms a dumpling containing the stirring blades 4A, 4B. In the state shown in FIG. 4, stirring and mixing of the excavated earth and sand and the chemical solution may become impossible. However, in order to prevent such a situation from occurring, the excavation work is interrupted in a timely manner and the rod 1 is stopped. Reverse drive is performed.

When the rod 1 rotates in the reverse direction, the stirring blades 4a, 4a
The operating claw 8, 8 at the tip of the arm rotates in the direction of arrow B in FIG. 3 due to the resistance when the tip 8a, 8a hits the surrounding ground.
Due to this rotation, the links 13, 13 are pulled, and the mud removing plates 5, 5 are forcibly turned around the shafts 7, 7 in a direction away from the rod 1, and the movement surrounds the rod 1. The sediment is moved, and this triggers the dumpling-shaped sediment to be subdivided and divided into stirring blades 4A, 4A.
A and 4B are exposed again, and the original stirring and mixing function is restored. As described above, when the viscous ground is excavated, good ground improvement can be performed by intermittently performing the above operation several times.

When the rod 1 is returned to the normal rotation and the excavation operation is resumed, the working claws 8, 8 are forcibly moved to the retreat position by the tips 8a, 8a contacting the surrounding ground excavated by the excavation head 2. Since it is returned, the mud elimination plates 5, 5 are returned to such positions on the outer periphery of the rod 1 via the links 13, 13 as shown in FIG.

The mud elimination plates 5, 5 are not limited to plate-like ones, but may be comb-like ones.

[0022]

As described above, according to the present invention, it is possible to eliminate the sediment adhering to the agitating blade and its surroundings only by reversing the rod in a timely manner during the improvement of the viscous geological ground. The stirring and mixing action between the earth and sand and the chemical solution can be favorably performed, and the accuracy of ground improvement can be significantly increased.

[Brief description of the drawings]

FIG. 1 is a front view of a main part showing an embodiment of a stirring head according to the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG. 1;

FIG. 3 is an operation explanatory diagram when the rod is reversed from the state of FIG. 2;

FIG. 4 is an explanatory view showing a conventional problem.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rod 2 Excavation head 3 Chemical supply path 4A, 4B Stirrer blade 5 Mud removal plate 8 Working claw 10 Interlocking mechanism 13 Link

Claims (2)

[Claims] 1. A ground improvement stirring head having a plurality of stages of stirring blades attached to a lower end of a rotatably suspended rod connected to a driving unit, and an outer periphery of the rod between the stirring blades provided in the plurality of stages. A movable claw is provided at the outer end of the stirring blade at the outer end of the agitating blade so that the movable claw can be expanded by receiving the resistance of earth and sand by reversing the rod. Wherein the mud elimination plate pivots in a direction away from the rod via the interlocking mechanism when the operating claw is expanded. 2. The ground improvement according to claim 1, wherein the interlocking mechanism is configured such that a position eccentric to the pivot of the operating claw and a position away from the pivot of the mud elimination plate are connected by a link. Stir head.