JP2849648B2 - Mixing stirrer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to soil improvement in which soft soil and a solidified material are mechanically mixed by rotating a drilling shaft provided with a drilling wing into the ground, thereby forming a pile in the ground. The present invention relates to a mixing / stirring device for use.

[0002]

2. Description of the Related Art Conventionally, as a method for improving the ground,
A method of providing a columnar anchor body in soft soil is generally used. There are various methods for providing the anchor body in the ground.

One of the methods is to drive a concrete column into the ground. However, since a long one is driven by impact, there are many problems such as cost and noise, and the method is gradually shunned because it is not suitable for an urban area. It is a construction method.

[0004] There is also a method in which a perforation is made in the ground with a drilling machine or the like, and concrete is poured into the hole and solidified (in-place concrete piling method). In this method, the soil is pulled up while digging, and concrete is poured.Instead, the driving equipment becomes rather large, and in the case of geology where the wall of the hole made easily breaks, the bentonite wall is used as the inner wall. It is necessary to prevent collapse by forming or inserting a casing.

In view of the above, recently, a drilling shaft provided with a drilling wing is rotated by a drilling mechanism provided on the ground, and a solidified material is fed from a fluid passage provided in the drilling shaft without pulling up soil. During the excavation or withdrawal, a type of injection method of discharging a solidified material from a discharge port near the tip to mix and agitate to form a pile has been often adopted.

[0006]

However, in this construction method, the excavated soil is kneaded with a solidifying material to condense and solidify the soil in a pile shape. If kneading is not performed reliably, there is a disadvantage that the effect is not accompanied.

[0007] This is greatly affected by the soil quality of the ground. In particular, in the case of clay, the excavated soil rotates together with the excavation wings and the like, and the stirring effect is weakened, so that proper mixing with the mixed material cannot be achieved, and a predetermined strength cannot be obtained. Accordingly, in such a case, conventionally, a method of increasing the stirring time or kneading by repeatedly moving the excavating shaft up and down has to be adopted, and the work efficiency has been significantly reduced.

[0008] For this reason, a major factor that lowers the mixing efficiency of the excavated soil and the solidified material is that the excavated soil is co-rotated with the excavation wing or the like. Various improvements have been made as a means. For example, there is a type in which a co-rotation prevention wing having a diameter larger than the digging diameter of the ground by the digging wing is provided between the digging wing and the stirring wing. That is, this co-rotation prevention wing is rotatably attached to the excavation shaft, and when excavating the excavation shaft, the tip portion of the prevention wing fits into the ground and stops without rotating. . Accordingly, since the rotation of the earth mass that is co-rotated with the excavation wing is prevented by the prevention wing, the stirring efficiency provided by the stirring wing provided above the earth mass is increased.

[0009] However, although this prevention wing is extremely useful in resolving the above-mentioned drawbacks, since the prevention wing is a method of fitting into the ground, there is a drawback that an extremely large force is applied to the excavation shaft, particularly during excavation. is there. The excavation wing goes down while rotating, but the prevention wing does not rotate and goes down vertically, so a force greater than the excavation wing is applied. For this reason, it is necessary to replace the prevention wing extremely frequently, resulting in extremely low work efficiency.

[0010]

In view of the above situation,
The inventor of the present invention has completed the apparatus of the present invention as a result of diligent research, and the feature of the apparatus is that a drilling wing is fixed at the tip, and a fluid passage for sending out a liquid solidified material is provided inside. An excavation shaft, which is used in a soil improvement method for forming a pile in the ground by mixing and solidifying the soil and the solidified material by excavating or pulling the excavation shaft while rotating the excavation shaft. Have a different center from the center
Eccentric inner cylinder installed on the excavation shaft, free around it
The outer cylinder that rotates at
Girder counter-rotating mechanism, fixed to the excavation axis and rotating together
In a device having a stirring blade, the co-rotation prevention mechanism is
Only one is provided between the drilling wing and the stirring blade, and
Regardless of the position of the outer cylinder,
Is located outside the circle due to the rotation of the excavator wing
And the co-rotation prevention member is almost flat on a horizontal surface.
It is a substantially parallel plate-shaped and tapered triangular shape.
The point is that three are provided with a central angle of 0 °.

[0011] The excavation shaft means a drilling wing fixed to the tip end, and provided with a flow passage for sending out the solidified material inside. The excavating shaft is connected to an excavator, and is driven up and down while being rotated. The structure of the excavator and the like is not particularly limited, and may be equivalent to a conventional one.

[0012] The solidifying material means a material which is solidified by stirring and kneading with the soil excavated by the apparatus of the present invention. The solidified material is discharged from a discharge port provided at the tip of the excavation shaft through a flow path provided inside the excavation shaft by a separately provided pumping device. As the material of the solidifying material, a conventional material may be used, and cement milk is generally suitable. In addition, an emulsion obtained by adding water to bituminous material, a chemical solution of a silicate system in which sodium aluminate, sodium bicarbonate, calcium chloride, etc. are added to sodium silicate, and a chemical solution in which a catalyst necessary for polymerization is added to calcium acrylate may be used.

[0013] The eccentric inner cylinder is eccentrically fixed to the excavation axis. Eccentricity means that the center of rotation of the excavation shaft is deviated from the center of the inner cylinder. Therefore, when the excavation shaft rotates, the inner cylinder rotates eccentrically about the rotation center of the excavation shaft.

The outer cylinder is rotatably fitted into the inner cylinder, and has an inner diameter slightly larger than the outer diameter of the inner cylinder.

The co-rotation prevention member is a member whose tip intrudes into a soil portion where the excavation blade is not excavated, that is, a portion where the excavation wing is not excavated. This is three and the same plane
At a 120 ° angle to each other
Attach.

[0016] Regardless of the position of the outer cylinder, the co-rotation prevention member must have a length such that at least one tip portion is located outside a circle formed by the rotation of the excavating wing. This always indicates that at least one is stuck in the undigged soil.

The co-rotation prevention member has a plate shape.
The stirrer can be fixed. The stirrer prevents co-rotation
In addition to the member, it can be provided on the outer cylinder.

There is no problem because the inner cylinder is fixed to the excavation shaft, but since the outer cylinder is free, it must be rotatably supported so that it does not fall downward. As a means for rotatably supporting the excavator, a support disk may be fixed to the excavation shaft and simply placed on the excavation shaft, or may be supported by a bearing.

The principle of preventing co-rotation of the present invention will be described. The co-rotation prevention member of the present invention exhibits the co-rotation prevention effect as described below because it is provided eccentrically with the actual rotating shaft (excavation shaft) and is free from the rotating shaft.

When the inner cylinder rotates eccentrically, the outer cylinder tends to rotate with it, but the outer cylinder itself is provided free because the co-rotation prevention member penetrates into the soil and creates resistance. Therefore, it does not rotate. Further, when further rotating, the co-rotation prevention member that has entered due to the eccentricity of the inner cylinder starts to come off,
The next anti-rotation member starts to enter. Repeat this. Theoretically, the anti-rotation member rotates slowly in the direction opposite to the rotation direction of the excavation axis. However, in actual experiments, it does not work as expected, and moves in a complicated way. This is probably because the resistance of the co-rotation prevention member in the soil in the direction of intrusion, the resistance in the direction of rotation, and the like are not uniform. However, the effect of preventing co-rotation without performing the same rotation as the excavation wing is sufficiently exhibited.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The theory of the present invention will be described below based on an example shown in the drawings. FIGS. 1 to 6 are views of the co-rotation preventing member viewed from above. There are a digging shaft 1, an inner cylinder 2, and an outer cylinder 3 from the center, and three co-rotation preventing members 4 are attached to the outer cylinder 3. ing. The surrounding great circle 5 is the excavated area. These drawings are merely schematic diagrams and are merely for explaining the principle. Here, the movement of each member is considered based on the rotation angle of the excavation axis. Now, in the state of FIG. 1, the rotation angle is set to 0 degree (the upper side of the figure, the direction at 12:00 of the clock is 0 degree).

In this state, when the excavating shaft rotates clockwise (in the direction of the arrow), the inner cylinder 2 rotates not on its own center but on the center 6 of the excavating shaft. In addition, outer cylinder 3
Also tries to rotate in the direction of the arrow, but because it is free, there is no rotational force. Then, since the co-rotation prevention member 4A in the 0-degree direction has penetrated into the soil, the rotation is stopped at that portion, and the inner cylinder and the outer cylinder slide.

FIG. 2 shows a state in which the central angle is rotated by about 30 degrees. The rotation shaft is rotated by 30 degrees, but the outer cylinder is hardly rotated because the co-rotation preventing member is fixed at an upper portion. However, because the inner cylinder is shifted to the right,
The whole is shifted rightward, and the lower right rotation prevention member 4B is entering the wall soil.

FIG. 3 shows a state in which the central angle is rotated by about 90 degrees. The lower right rotation prevention member 4B is almost completely fitted. FIG. 4 shows a state in which the central angle is rotated by about 150 degrees. Similarly, the lower right rotation prevention member 4B has begun to come off, and the lower left rotation prevention member 4C has been fitted.

FIG. 5 shows a state rotated about 230 degrees. The lower left rotation prevention member 4C is almost completely fitted. FIG. 6 is rotated about 300 degrees. It can be seen that the upper co-rotation prevention member 4A is fitted and is in the same state as in FIG. However, the upper co-rotation prevention member 4A is about 3
It rotates 0 degrees counterclockwise. That is, the outer cylinder (counter-rotation prevention member) rotates in the opposite direction to the rotation of the excavation shaft due to the resistance caused by the fitting of the counter-rotation prevention member.

Thus, it is clear that the co-rotation preventing member does not co-rotate with the excavation axis. Therefore, at least the soil above the co-rotation preventing member does not co-rotate. Further, since the outer cylinder is the same, if a stirring blade or the like is separately fixed to this outer cylinder, co-rotation can be prevented at that portion.

FIG. 7 is a cross-sectional view showing the use state of one example of the mixing and stirring device of the present invention. Inner cylinder (not shown) on excavation shaft 1
Are fixed, and the outer cylinder 3 is rotatably provided around the outer cylinder 3. The outer cylinder 3 is rotatably supported on a support plate 7 fixed to the excavation shaft 1. Three co-rotation prevention members 4 are mounted around the outer cylinder 3. Further, a stirring blade 8 is provided above the outer cylinder 3. The stirring blade 8 is provided with the outer cylinder 3
Instead, it is fixed to the excavation shaft and rotates together with the excavation wing 9. In this figure, the number of the stirring blade 8 is one, but it is appropriately determined.
It is not a limitation if it is turned on.

When the excavating shaft 1 rotates, the excavating wing 9 naturally rotates. The whole goes down with it. The soil immediately above the wing 9 rotates together with the wing 9 (co-rotation).
However, due to the anti-corotation member 4 immediately above, as described above, the edge is cut at that position, and co-rotation does not occur above that. Further, in the stirring blade 8 is co around prevention member thereabove also another rotation (same as excavation blades)
This not only prevents partial co-rotation, but also improves stirring efficiency.
Very high.

[0029]

As described above, in the mixing and stirring apparatus according to the present invention, an eccentric inner cylinder is provided on the excavation shaft so as to have a center different from the rotation center of the excavation shaft, and the eccentric inner cylinder is provided around the inner cylinder free of it. A rotating outer cylinder is provided, and a co- rotation preventing member is provided around the outer cylinder.
The following effects are obtained by the structure such as the provision of the book. It is possible to almost completely prevent the rotation of the soil. In particular, it is more complete if various stirring blades are provided. Compared with the conventional example described above, the co-rotation prevention member of the present invention has a very low resistance when moving downward because the insertion and extraction occur alternately. Therefore, there is almost no damage or breakage of the co-rotation prevention member.

[Brief description of the drawings]

FIG. 1 is a plan view of a counter-rotating member of a mixing and stirring device according to the present invention as viewed from above.

FIG. 2 is a plan view of a co-rotation preventing member of the mixing and stirring device according to the present invention as viewed from above.

FIG. 3 is a plan view of the co-rotation preventing member of the mixing and stirring device according to the present invention as viewed from above.

FIG. 4 is a plan view of the co-rotation preventing member of the mixing and stirring device according to the present invention as viewed from above.

FIG. 5 is a plan view of the co-rotation preventing member of the mixing and stirring device according to the present invention as viewed from above.

FIG. 6 is a plan view of the co-rotation preventing member of the mixing and stirring device according to the present invention as viewed from above.

FIG. 7 is a sectional view showing a use state of the mixing and stirring device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drilling shaft 2 Inner cylinder 3 Outer cylinder 4 Co-rotation prevention member 5 Great circle 6 Rotation center 7 Support member 8 Stirrer blade 9 Drilling blade

Claims (1)

(57) [Claims] 1. A drilling shaft having a drilling wing fixed to a tip end and a fluid passage through which a liquid solidified material is delivered is provided.
A device used for a soil improvement method of forming a pile in the ground by mixing soil and solidified material by excavating or pulling out while rotating in the ground, the center being different from the rotation center of the excavation shaft An eccentric inner cylinder provided on the excavation shaft so as to have, an outer cylinder that rotates freely around the inner cylinder, and a co-rotation prevention mechanism provided with a co-rotation prevention member around the outer cylinder;
And a stirring blade fixed to the excavation shaft and rotating together, wherein only one co-rotation preventing mechanism is provided only between the excavating blade and the stirring blade, and At least one tip has a length that is located outside the circle due to the rotation of the excavator wing, and the co-rotation prevention member is a plate-shaped and tapered triangular shape substantially parallel to the horizontal plane. And three mixing stirrers having a central angle of 120 ° with each other.