JPS6351515A - Excavator for ground improvement - Google Patents

Abstract

PURPOSE:To uniformly mix sludge with a hardening agent by a method in which stirring blades loosely fitted at the outside and inside of a rotary shaft are projectionally provided to the rotary cylinder with an excavating blade concentrically, and an outlet for hardening agent is provided at the lower end of the rotary shaft. CONSTITUTION:A hollow rotary shaft 2 is fixed projectingly upwards to the center axis of a rotary cylinder 1, and stirring blades 4 are projectionally provided at a given interval on the inner wall of the cylinder 1. Stirring blades 5 are also projectionally provided to the outer wall of the shaft 2 and loosely fitted with the blades 4. A plurality of blades 8 are fixed to the tapered lower outer wall 6a of a cylindrical attachment 6 fixed to the lower end of the cylinder 1 and blades 10 are fixed to the lower end edges of slewing blades 9 fixed to the lower end of the shaft 2, A nozzle 11 is connected to the extension fine of the lower end of the shaft 2 to discharge a hardening agent from it.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an excavating tool for soil improvement, and belongs to the field of civil engineering machinery.

(Prior Art) Conventionally, in order to improve soft ground, a method of injecting and stirring a hardening agent into excavated ground has been adopted.

As excavating tools for this ground improvement, various structures equipped with excavating blades and stirring blades have been proposed (for example, JP-A-01-10G20, JP-A-6L-17G31,
JP-A No. 1983-17F332, JP-A No. 61-4091
No. 7, etc.).

(Problem to be solved by the invention) However, in the conventional excavating tool, the stirring l was a lock installed at the lower end of the rotating shaft, so it was difficult to sufficiently stir and mix the excavated mud and hardening agent. In order to do this, it was necessary to move the stirring blade up and down frequently, and there was also the problem that the hole wall could be damaged by the up and down movement of the stirring blade. If the hole wall is damaged, the injected hardening agent will leak out to the outside of the hole wall, so the amount of hardening agent injected must be increased accordingly, but it is difficult to determine the required amount on the ground. This was difficult and sometimes caused variations in the performance of improved soil temperature.

(Means for solving the problem) Therefore, the present invention penetrates a cylindrical body into the excavated ground, and makes it possible to stir the excavated soil and hardening agent over almost the entire length of the cylindrical body, thereby improving the structure of the conventional method. It solved the problem.

That is, the ground improvement excavating tool of the present invention has a rotary cylinder provided with a cutting blade at its lower end and a rotary shaft that are coaxial and rotatable with respect to each other, and there are approximately The apparatus is characterized in that stirring blades are protruded over the entire length and are loose with each other, and a curing agent discharge part is provided at the lower end of the rotating shaft.

It is preferable that the excavating blade of the rotary tube has a blade protruding radially from the outside of the end of a cylindrical attachment that is detachable from the rotary tube, and the inner diameter of the cylindrical axotiment is set to the diameter of the rotary tube. The amount of excavated soil introduced into the rotary cylinder can be controlled by making the diameter approximately equal to or smaller than the diameter of the rotary cylinder.

Stirring By making the distance approximately equal to the distance to the outside, the stirring capacity can be maximized.

Further, the rotating shaft is preferably a hollow shaft, and by connecting a nozzle to the lower portion 41, an injection path for the curing agent can be formed.

(Function) According to the excavating tool for ground improvement of the present invention, since the stirring part is provided over almost the entire length of the rotating tube and rotating shaft, the mud and hardening agent can be uniformly mixed in the range from the surface of the ground to the depths of the ground. Can be mixed. Furthermore, since the excavated mud and hardening agent are mixed inside the rotary cylinder, a desired mixing ratio can be achieved.

(Example) Examples of the present invention will be described below with reference to the drawings. 1 in the figure is a rotary tube made of a penetrating tube, and a hollow rotating shaft 2 is disposed on the central axis of the rotary tube 1. It penetrates the top plate 3 of the rotary cylinder 1 and protrudes upward.

Stirring blades 4.4 are installed at predetermined intervals on the inner wall of the rotating cylinder 1.
protrudes toward the center and rotates! F! f12
Similarly, stirring blades 5.5 are provided radially protruding from the outer wall of the stirring blade 5.5, and the stirring blades 5.5 and 4.4 are loosely interlocked with each other. The length of each stirring blade 4.5 is approximately equal to the length from the inner wall of the rotating cylinder 1 to the outer wall of the rotating shaft 2.

A cylindrical attachment 6 as shown in FIG. 3 is fitted into the lower end of the rotary cylinder 1 and fixed with bolts 7. The inner diameter of the lower part of the cylindrical attachment 6 is slightly smaller than the inner diameter of the rotary cylinder 1, while the outside of the lower part! 26a has a tapered shape, and a plurality of blade bodies 8.8 are radially fixed to the root portion thereof to constitute the excavation blade of the rotary cylinder 1.

On the other hand, a swirler 9.9 is diametrically symmetrically fixed to the lower end of the rotating shaft 2, and a blade 10 is attached along the lower edge of the swirler 9.
．． 10 is fixed to constitute the excavating blade of the rotating shaft 2.

A nozzle 11 is connected to the extension of the lower end of the rotating shaft 2, and the curing agent injected from the upper end of the rotating shaft 2 is passed through the nozzle 1.
1, it can be released into the soil.

As shown in FIG. 1, the excavation tool of the above embodiment is provided at the lower end of a nine-rotary tube 1 that is connected to a rotating device 12 and used by rotating the rotary tube 1 and the rotary IFI 2 in opposite directions. The ground to be improved is excavated by the excavating blade provided at the lower end of the rotary shaft 2, and the entire excavating tool penetrates into the ground as it excavates.

At the time of penetration, an amount of mud corresponding to the inner diameter of the lower part of the cylindrical attachment 6 flows into the inside of the rotary cylinder 1, so if the hardening agent is discharged from the nozzle 11 through the rotating shaft 2, the mud and hardening agent are removed. , inside the rotating cylinder 1, stirring blades 4.4.5.5
The mixture is evenly mixed.

In this case, the hardening agent and mud are stirred and mixed in the area partitioned by the rotary cylinder 1, so that all the hardening agent injected and the mud that has flowed into the inside of the rotary cylinder 1 can be sufficiently mixed, and the soil surface Since it stirs in the area that reaches the digging blade,
It is possible to make the entire mixture uniform, and ground improvement work can be carried out using the designed mixture ratio.

When the excavation tool penetrates to the planned depth, it is pulled out while rotating the rotary tube 1 and the rotary shaft 2, and the same operation is performed at the next point.

(Effects of the Invention) As explained above, according to the present invention, the excavated mud and the injected hardening agent can be mixed uniformly, and the mixing ratio can also be controlled. This has the effect of making the performance uniform.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway front view of an embodiment of the present invention, Fig. 2 is a sectional view taken along line A-A in Fig. 1, and Fig. 3 is a lower side oblique view of the cylindrical attachment in the embodiment. This is the parent diagram. 1... Rotating cylinder 2... Rotating shaft 11.5...
- Stirring blade 6... Cylindrical nozzle 8.10... Blade body 11... Nozzle 12... Rotating device

Claims (1)

[Scope of Claims] 1. A rotary cylinder, each having a cutting blade at its lower end, and a rotary shaft are coaxial and rotatable with respect to each other. An excavating tool for ground improvement 2 characterized by protruding stirring blades that play with each other and a curing agent release part provided at the lower end of the rotating shaft. Excavation tool 3 for ground improvement according to claim 1, wherein a blade body is radially protruded outside the end of a cylindrical attachment that can be attached to and detached from the cylinder.The inner diameter of the cylindrical attachment is approximately equal to the diameter of the rotating cylinder. Excavation tool 4 for ground improvement according to claim 2, which has the same or smaller diameter. Claim 1, wherein the stirring blade has a distance approximately equal to the distance from the inside of the rotating cylinder to the outside of the rotating shaft. Ground improvement drilling tool 5 The ground improvement drilling tool according to claim 1, wherein the rotating shaft is a hollow shaft, and a nozzle for discharging a hardening agent is connected to the lower end.