JPH06128945A - Subsoil improvement mixing device - Google Patents

Abstract

PURPOSE:To make it possible to cut finely excavated earth and mix the finely cut earth with a fixing material around a pile with high efficiency in a mixing and agitation device equipped with an agitation blade and a stationary blade. CONSTITUTION:A drilling blade 3 and a spray nozzle 5 for water and an earth improvement material 6 are mounted to the tip of a rotary shaft 2. An agitation blade 7 is fixed to the upper part of the nozzle. Two cylindrical bodies 8 are loosely fitted directly over the agitation blade 7 or directly under the blade 7. Stationary blades 9 are protrusively installed to the cylindrical bodies 8 in the radial direction. Bulged plate springs 10 are interposed outwardly between the tips of the stationary blades 9 in the upper part. Furtheremore, a spring 11 is installed to the upper part of the stationary blade 9 located high above so as to energize the upper part stationary blade 9 downward if necessary.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground improvement mixing and stirring apparatus, and more particularly, to a ground improvement mixing and stirring apparatus in which a stirring blade and a stop blade are combined to enable efficient stirring and mixing. It is a thing.

[0002]

2. Description of the Related Art A mixing and stirring apparatus for ground improvement mechanically mixes excavated soil and a pile circumference fixing liquid, and the mixture is solidified to improve the ground into a cylindrical shape. A mixing and agitating device for ground improvement, which is a combination of a conventional stirring blade and a stop blade (co-rotation prevention blade), forcibly restrains the rotation of the stop blade from the ground and the stop blade in the soil. It is known that the length of the excavation hole is larger than the diameter of the excavation diameter, and the rotation of the excavation hole is stopped by cutting the excavation wall from the start to the completion.

[0003]

Among the above, the former stop blade is surely stopped, but if an obstacle is bitten between the stop blade and the excavation blade or the stirring blade, the stop blade is damaged. There are many. Further, since the fixed shaft of the excavating blade and the stopping blade normally has a double structure, twisting is likely to occur when the soil is shredded.

In the latter stop blade, the length of the stop blade must be adjusted according to the situation of the surrounding ground. Furthermore, if the surrounding ground is hard, or if there are boulders or obstacles on the wall surface of the drill hole, the stop blade cannot cut into the wall of the drill hole and impair the smoothness of the drilling speed. Furthermore, when the distance between the stirring blade and the stop blade is fixed, the stop blade may rotate together with the stirring blade when an obstacle bites in the meantime. descend.

Therefore, in a ground improvement mixing and stirring apparatus having a stirring blade and a stop blade, in order to efficiently shred the excavated soil and mix the shredded excavated soil with the pile circumference fixing material. Therefore, a technical problem to be solved arises, and an object of the present invention is to solve the problem.

[0006]

The present invention has been proposed in order to achieve the above object, and is provided with an excavating blade and a nozzle for ejecting ground improvement material at the tip of a rotary shaft, and In a mixing and stirring device configured to stir the excavated soil and the ground improvement material ejected from the nozzle with a stirring blade fixed to the rotating shaft, directly above the stirring blade fixed to the rotating shaft. Alternatively, two tubular bodies are loosely fitted immediately below each other, and one or both of the tubular bodies are configured to be able to move up and down to some extent. For improving the ground, a stop blade having the same or a short diameter as the diameter of the excavation hole is fixed in the diametrical direction, and a leaf spring bulging outwardly is interposed between the tip ends of the upper and lower stop blades. The mixing and agitating device and the above-mentioned stop blade are urged downward by springs. It is intended to provide.

[0007]

The excavation hole is excavated by the excavation blade provided at the tip of the rotating shaft, and the excavated soil generated by the excavating operation is accompanied by the rotation of the stirring blade fixed to the rotating shaft. Move to rotate. At the same time, a ground improvement material such as cement milk is ejected from a nozzle provided at the tip of the rotary shaft, and rotates and moves together with the excavated soil. At this time, the upper and lower stop blades try to rotate about the rotation axis by the rotational movement of the excavated soil, but since the leaf spring is bulged outward in a scalloped manner, The leaf spring presses against the hole wall of the excavation hole to restrain the action of the rotation and stop. Thus, the excavated soil that is rotating and moving is shredded between the rotating stirring blade and the stopped stopping blade, and the shredded soil and the ground improvement material are stirred and mixed. It

Further, in the invention according to claim 2, wherein the upper stop blade is urged downward, the upper stop is stopped when the leaf spring is pressed in the direction of the rotation axis from the hole wall of the excavation hole. The wings move a little upwards and rest at a balanced point to perform the above-mentioned function. Further, since the stop blade of the invention described in claim 1 is also configured to be able to move up or down to some extent, the stop blade of the invention described in claim 2 is the same as the stop blade of the invention described in claim 2. The leaf spring is deformed by arbitrarily moving up and down depending on the hardness of the hole, and effectively presses the hole wall of the drill hole to stop. Further, even if the obstacle bites, the stop blade moves and escapes, so that the stop blade is not damaged. Furthermore, the elastic force of the coil spring that urges the upper stop blade downward can be arbitrarily adjusted to select a surface pressure suitable for the hardness of the surrounding ground.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIGS. For the sake of convenience of description, a configuration which is conventionally known will be described at the same time. In the figure, 1 is a soft ground to be improved. The soft ground 1 is dug down by the rotation of the excavating blade 3 fixed to the tip of the rotary shaft 2 to form a hole 4
To form. Then, a ground improvement material 6 such as cement milk is ejected from a nozzle 5 provided at the tip of the rotary shaft 2 and injected into the excavated soil excavated by the excavating blade 3.

Further, stirring blades 7, 7, ... Are fixedly mounted on the rotary shaft 2. Therefore, the stirring blades 7, 7 ... Rotate in the same direction as the rotary shaft 2 and the excavating blade 3 rotate, and serve to mix and stir the excavated soil and the ground improvement material 6. However, although rotation of the excavating blade 3 and the rotary shaft 2 in the same direction can rotate and move the excavated soil in the same direction, the excavated soil can be crushed or efficiently mixed with the ground improvement material for stirring. The effect cannot be expected.

In view of this, in the present invention, two cylindrical bodies 8, 8 are provided in the vicinity of the tip of the rotary shaft 2 directly below or above the stirring blades 7, 7 with a predetermined interval above and below. Then, the stop blades 9 and 9 are respectively provided on the cylindrical bodies 8 and 8 so as to project in the diameter direction of the rotating shaft 2 and linearly in plan view. The tip portion of 9 is formed to slightly contact the hole wall of the excavation hole 4. Further, in the illustrated example, the lower stop blade 9 is configured to be able to move up and down to some extent, and the upper stop blade 9 is configured to hardly move up and down.
It should not be limited to this. Further, the upper and lower end portions of the leaf springs 10, 10 that bulge outward in a scalloped shape as shown in FIG. 5 are pivotally supported at both ends of the upper and lower stop wings 9, 9, respectively. Thus, the leaf springs 10 and 10 are configured to press the hole wall of the excavation hole 4 in a normal state.
In addition, the holding parts 10a, 1
0a may be provided.

Further, as shown in FIGS. 3 and 4, the coil spring 11 for constantly pressing the upper stop blade 9 downward is provided with the rotating shaft 2.
The upper surface of the coil spring 11 is locked by a stopper 12 which is wound around the coil spring 11 and is capable of adjusting the spring pressure of the coil spring 11. Since one embodiment of the present invention relates to the apparatus as described above, the soft ground 1 to be improved is successively dug down by the rotation of the drilling blade 3 to form the drilled hole 4. The excavated soil excavated by the excavating blade 3 is the excavating blade 3
Also, the stirring blade 7 is rotated to move. Further, a ground improvement material 6 such as cement milk is ejected from a nozzle 5 attached to the tip of the rotary shaft 2 and rotates and moves together with the excavated soil. At this time, the upper and lower stop blades 9, 9 try to rotate together with the rotary shaft 2 as the center of rotation by the rotational movement of the excavated soil, but are interposed between the end portions of the upper and lower stop blades 9, 9. Harami-shaped leaf springs 10, 10 press the hole wall of the excavation hole 4 by the elastic force of the leaf springs 10, 10 or the bias of the coil spring 11 which assists the elastic force, and then rotate together. And stop the action.

In this way, the excavated soil that is rotating and moving between the rotating stirring blades 7, 7 ... And the stopped blades 9, 9 is shredded, and the shredded soil is further cut. The ground improvement material 6 is efficiently agitated and mixed. The present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention extends to the modified one.

[0014]

As described in detail in the above one embodiment, the stop blade loosely fitted to the rotary shaft is the stirring blade fixed to the rotary shaft. It tries to rotate in the same direction due to the excavated soil that is rotating by rotation,
The stop blades are stopped by pressing a hole wall of the excavation hole with a spring-shaped spring plate provided at the tip of the stop blades. Thus, the excavated soil is shredded between the rotating stirring blades, and the ground improvement material is well mixed and stirred with the shredded excavated soil to form a solid cylindrical improved ground. You can

Further, since the leaf spring is deformed according to the subtle difference in size and hardness of the excavation hole, the excavation and pull-up operation can be performed extremely smoothly. Further, even if there is an obstacle in the drilling hole, it does not hinder the above-mentioned operation for advancing and pulling, and even if an obstacle is caught between the stirring blade and the stop blade, the stop is stopped. Since the blade moves along the rotation axis and escapes, there is no possibility that the rotation axis or the drive unit is overloaded or the stirring blade or the stop blade is damaged. Further, the coil spring assists the elastic force of the leaf spring by urging the upper stop blade in the invention of claim 2 downward, and the elastic force of the coil spring itself is arbitrarily adjusted according to the situation. It is an invention that achieves a great variety of effects, such as being able to press the stop blade against the hole wall of the excavation hole to surely stop it.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of a ground portion of the invention according to claim 1.

FIG. 2 is a partially cutaway vertical front view in the same excavation hole.

FIG. 3 is a partially cutaway front view of the above-ground portion of the invention according to claim 2;

FIG. 4 is a partially cutaway vertical front view in the excavation hole.

FIG. 5 is a perspective view of a leaf spring.

[Explanation of symbols]

 1 Soft Ground 2 Rotating Axis 3 Drilling Blade 4 Drilling Hole 5 Nozzle 6 Ground Improvement Material 7 Stirring Blade 8 Cylindrical Body 9 Stopping Blade 10 Leaf Spring 11 Coil Spring 12 Stopper

Claims (2)

[Claims] 1. An excavating blade and a nozzle for ejecting ground improvement material are provided at the tip of a rotating shaft, and excavated soil excavated by the excavating blade and the ground improving material ejected from the nozzle are fixed to the rotating shaft. In the mixing and stirring device configured to stir with the stirring blade, two cylindrical bodies are loosely fitted directly above or below the stirring blade fixed to the rotary shaft with a predetermined interval, and Alternatively, both tubular bodies are configured to be able to move up and down to some extent, and stop blades having the same or a short diameter as the bore diameter of the excavation hole are fixed in the diameter direction of the upper and lower tubular bodies. A mixing and agitating device for ground improvement, comprising leaf springs bulging outward between the upper and lower stop blades. 2. The ground improvement mixing and stirring apparatus according to claim 1, wherein the upper stop blade is urged downward by a spring.