JPH08226120A - Excavation and agitation mixing device - Google Patents

Abstract

PURPOSE: To obtain a better agitation and mixing result, and an improved column of high strength, compared with the conventional case. CONSTITUTION: Regarding a soil improvement machine for advancing and retreating an excavation shaft 21 having an excavation blade 22 on the front end and a plurality of stages of agitation blades 23 behind the blade 22, under rotation for mixing and agitating soil and a compound filler on the operation of the prescribed excavation propelling mechanism, concurrent turn prevention blades 26 having a larger outer diameter than the blade 22 are rotatably mounted on the shaft 21. In addition, the blades 26 are arranged at two positions between the blade 22 and the first stage of the blade 23 and between the first and second stages of the blades 23.

Description

Detailed Description of the Invention

[0001]

[Field of Industrial Application] The present invention is a ground improvement work for civil engineering work, in which soil and filler are mechanically mixed and solidified, and a large number of improved columns are installed in the ground to mix cutting soil. The present invention relates to a drilling stirring mixing device for efficiently stirring.

[0002]

2. Description of the Related Art A conventional excavator-mixer is shown in FIGS.
As shown in Japanese Patent Publication No. 58-29374, a predetermined excavation blade 2 is provided on the excavation shaft 1, and a stirring blade 3 located above the excavation blade 2 and having substantially the same diameter as the excavation blade 2 are vertically arranged in a plurality of stages. The excavation shaft 1 is fixed between the excavation blade 2 and the stirring blade 3 of the excavation shaft 1 and between the stirring blades 3 with a plurality of stirring blades 3 separated from each other, and the excavation diameter Da is larger than the excavation diameter Da. The co-rotation preventing device 4 having a large diameter Db was inserted and fitted. As shown in the figure, the co-rotation preventing device 4 is formed by fixing two co-rotation preventing blades 6 to a sleeve-shaped boss 5 in which the excavation shaft 1 is loosely fitted. Since the diameter is larger than the excavation diameter Da even if the excavation shaft 1 rotates, it does not rotate and is propelled into the soil. In addition, the rings 7a, 7 are attached to the excavation shaft 1 at positions above and below the boss 5.
b was formed so that the co-rotation preventing blade 6 did not move up and down. Since the excavation and agitation mixing device 4 has a better agitation and mixing of the filler and the soil than the device which has been used until then without the co-rotation preventing blade, a strong and improved column was formed.

Therefore, stimulated by the invention, the comb-teeth type stirring blade as shown in FIG. 4, the forward and reverse stirring blades as shown in FIGS. 5A to 5C, and the one as shown in FIG. Underground mixer type agitating blades have been manufactured and implemented to date. In both cases, the inner pipe 10a and the outer pipe 10 provided with the excavation blade and the stirring blade
b, and the outer pipe 10b is fixed on the ground to fix the inner pipe 10a.
Feed only by rotating only the outer tube 10b and the inner tube 10a
Are rotated in opposite directions to advance, and the discharge port 11 at the lower end
A filling material such as cement milk was ejected from (Fig. 4) and the soil and the filling material were mixed and stirred to form a cylindrical improved column.

[0004]

However, as shown in FIG. 2 and FIG.
In the conventional excavation and agitation mixing device shown in (1), since the co-rotation preventing blade 6 is rotatably attached to the excavation shaft 1, large-diameter gravel or boulders are mixed with the co-rotation preventing blade 6 and the excavation blade 2, or Stirring blade 3
Even if it is narrowed between the two, it is possible to prevent the co-rotation prevention blade 6 from rotating and prevent the excavation blade 2 and the stirring blade 3 from being damaged or the drive motor from stopping or being damaged. However, since the second co-rotation preventing blade 6 is installed with the plurality of stirring blades 3, 3 spaced from the tip, there is a drawback that the degree of stirring and mixing near the second co-rotation preventing blade 6 is poor. It was

Further, in the conventional excavation-mixing / mixing device shown in FIGS. 4 to 6, if large-sized gravel or boulder which hinders mixing / mixing is present in the ground to be ground-improved, they are forced to be reversed from each other. When such large-diameter gravel or boulder is narrowed between the rotating excavating blade 12 and the stirring blade 13, the stirring blade 13 or the excavating blade 12
Problems such as breakage of the machine and stop or damage of the drive motor occurred. Further, if fine earth and sand enter between the inner pipe 10a and the outer pipe 10b and the resistance increases, it becomes impossible to rotate. Therefore, it is necessary to carefully perform the construction to a deep depth.

The present invention has been made in view of the above-mentioned circumstances, and provides a drilling and stirring and mixing apparatus which solves the conventional drawbacks and is excellent in drilling and stirring and mixing.

[0007]

DISCLOSURE OF THE INVENTION The present invention provides an excavation blade having a tip with an excavation blade and a plurality of stages of stirring blades arranged above the excavation blade.
In a ground improvement machine for excavating and extracting while rotating by a predetermined excavation mechanism and mixing and stirring soil and filler, the tip is located outside the radius of rotation of the excavation blade and is a boss with respect to the excavation axis. Co-rotation preventive blades that are rotatably inserted through the blades are arranged at two positions between the excavation blade and the first-stage excavation blade and between the stirring blade and the second-stage stirring blade. It is characterized by

Further, the gap between the co-rotation preventing blade of the excavating and stirring mixer of the present invention and the excavating blade and the stirring blade is 30 cm or less.

[0009]

Since the co-rotation preventing blades are arranged above and below the one stirring blade, the stirring and mixing can be efficiently performed.

Further, if the clearance between the co-rotation preventing blade and the excavating blade and the stirring blade is set to 30 cm or less, large-sized gravel, boulders, etc. will not be caught in the clearance, resulting in overload of the drive motor. Does not occur. Even if it bites, the co-rotation prevention blade is pivotally attached to the excavation shaft via the boss, so the co-rotation prevention blade rotates and has the effect of passing large-diameter gravel. It can prevent the occurrence.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a front view showing an embodiment of the present invention. In the figure, reference numeral 21 denotes an excavation shaft, an excavation blade 22 is attached to the tip, and a filling material discharge port 21a is opened near the tip. Reference numeral 23 denotes a stirring blade, which has an outer diameter substantially the same as that of the excavation blade 22 and is arranged above the excavation blade 22 in a plurality of stages. The co-rotation preventing blade 26 is rotatable between the excavating blade 22 and the first-stage stirring blade 23 above it, and between the stirring blade 23 and the second-stage stirring blade 23 via bosses 25. It is attached to the upper and lower rings 27a, 27
It is configured so as not to move in the vertical direction by b. The co-rotation prevention blade 26 includes the excavation blade 22 and the stirring blade 23.
It has a larger diameter.

The clearance between the co-rotation prevention blade 26 and the excavation blade 22 and the stirring blade 23 is preferably 30 cm or less, and more preferably about 20 cm.

A case will be described in which ground improvement is carried out by using the excavation-mixing mixer equipped with the co-rotation preventing blade 26 described above. First, an excavation / mixing / mixing device is attached to the tip of a rod (not shown), and is rotated by a motor of a ground improvement machine (not shown) to spout a filling material such as cement milk from the discharge port 21a at the tip while advancing into the ground. A drilling hole having a diameter equivalent to the outer diameter of the blade 22 is formed, and the co-rotation preventing blade 26 having a diameter larger than this diameter does not rotate relatively because it bites into the ground around it and the excavation of the drilling shaft 21 is advanced. Is promoted into the soil. Therefore, the soil mass excavated by the excavation blade 22 at the tip of the excavation shaft 21 co-rotates together with the excavation blade 22, but the co-rotation prevention blade 26 stops the rotation of this soil mass, and the excavation blade 22 is crushed by the rotating excavation blade 22. Next, it is agitated and mixed with the filler with the stirring blade 23 thereon, and then further finely crushed with the second stage co-rotation prevention blade 26, and the filler is continuously supplied with the subsequent stirring blade 23. It is mixed with stirring.

FIG. 7 (a) shows a structure of a conventional excavation-mixing / mixing device in which co-rotation preventing blades separate a plurality of mixing blades.
In (b), the co-rotation preventing vanes are arranged in the excavating stirring mixing device of the present invention with one stirring vane separated. And
8 (a) and 8 (b) are for each depth when an improved pillar is constructed on the ground by the conventional device shown in FIG. 7 (a) and the device of the present invention shown in FIG. 7 (b). ² is a graph showing the uniaxial compressive strength (compressive strength only in the axial direction) q _u (kgf / cm ² ) measured in FIG. As shown, the device of the present invention is clearly stronger than the conventional device. In particular, the effect of improvement at a deep position is remarkable.

[0015]

According to the present invention described in detail above, the following effects are exhibited. (1) In the conventional apparatus, since two co-rotation preventing blades are arranged so as to separate a plurality of stages of stirring blades, the mixing degree of stirring between them is small, which is a weak point in terms of quality. In the present invention, the installation interval of the two co-rotation preventing blades is made small, and the stirring blades are present only in one stage between them. Therefore, the stirring mixing degree of the improved ground is substantially equal over the entire length of the ground improvement range. It is improved uniformly, and therefore the strength is also high (claim 1).

(2) If the gap between the co-rotation prevention blade and the excavation blade or the stirring blade is large, the stirring / mixing degree will decrease, so 30 cm.
In the following, stirring and mixing of the filler and the soil are well performed (claim 2).

[Brief description of drawings]

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

FIG. 2 is a vertical cross-sectional view at the time of construction by a conventional excavator-mixer.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a front view of a conventional excavator-mixer using a comb-shaped stirring blade with a double pipe.

FIG. 5 is a front view of a conventional excavator-mixer using a double-tube forward-reverse stirrer.

FIG. 6 is a front view of a conventional excavation stirring mixer using a double-pipe underground mixer type stirring blade.

FIG. 7 is a front view comparing a conventional excavation and mixing apparatus of the present invention with (a) showing the conventional and (b) showing the present invention.

FIG. 8 is a graph of a case where an improved column is constructed on the ground by the conventional apparatus shown in FIG. 7A and the apparatus of the present invention shown in FIG. 7B, in which FIG. 8A shows the columnar geology of the constructed ground, (B) is a graph which shows the uniaxial compressive strength for every depth of the improved pillar which was constructed.

[Explanation of symbols]

 21 Excavation Axis 21a Discharge Port 22 Excavation Blade 23 Stirring Blade 25 Boss 26 Co-rotation Prevention Blade

Claims (2)

[Claims] 1. An excavation shaft having a tip and a plurality of stages of stirring blades arranged above it is excavated and extracted while rotating by a predetermined excavation mechanism to mix and stir the soil and the filler. In the ground improvement machine, the co-rotation preventing blade, whose tip is located outside the radius of gyration of the excavating blade and is rotatably attached to the excavating shaft via a boss, is provided with the excavating blade.
An excavation-mixing / mixing device, which is disposed between two stages of the stage-blades and between the stirring vanes and the stages of the second-stage stages. 2. The excavating and stirring mixer according to claim 1, wherein a clearance between the co-rotation preventing blade and the excavating blade and the stirring blade is 30 cm or less.