JPH0493410A - Mixing and agitating vane device for foundation improvement machine - Google Patents

Abstract

PURPOSE:To enable a soil and a curing agent to be efficiently agitated by providing a co-turn prevention vane on the external surface of a boss for engagement with or disengagement from a connecting section formed on a part of a drill shaft, and further providing a stopper on the drill shaft under the connecting section. CONSTITUTION:When a rod 11 is driven and rotated, a drill shaft 1 is pressed into a ground 12, while causing pressure on the rod 1. An end drill bit 10, a co-turn prevention vane 7 and a drill vane 3 are concurrently driven and rotated, thereby drilling the ground 12 and softening the soil thereof. Also, the rotation and feed of the drill shaft 1 are interrupted to deliver a curing agent from a delivery port 14. In this state, the drill shaft 1 is lifted, while being rotated in a reverse direction for drilling. Furthermore, the boss 5 of the co-turn prevention vane 7 is disengaged from the connecting section, thereby stopping the drill shaft 1. In addition, when the drill shaft 1 while being lifted, is continuously rotated, the co-turn prevention vane 7 only moves up, and the drill vanes 3 and 9, while rotating, deliver the curing agent and agitate the soil, thereby forming an improved foundation column. According to the aforesaid construction, the co-turn prevention vane 7 does not rotate and, therefore, the drilled soil and curing agent can be well agitated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a mixing and stirring device for a ground improvement machine for improving soft ground. More specifically, it mechanically mixes and solidifies soil and a hardening agent in foundation work, etc., and is a mixing and stirring device for a ground improvement machine that improves the ground into a cylindrical shape.

[Prior art] Conventionally, ground improvement machines that improve soft ground into a cylindrical shape are
An excavation shaft equipped with excavation blades and stirring blades is rotated to excavate using a designated excavator tank, and during excavation or extraction, a solidifying agent such as cement milk is discharged from a passage provided in the excavation shaft and is forcibly stirred with the ground. Consolidate the ground in a cylindrical shape.

However, since this type of ground improvement machine forcibly mixes and stirs the solidifying agent and soil, it can be easily applied to sandy or silt soil, but it cannot be applied to clay, especially hard clay soil. However, the soil to be improved and the stirring blade rotate together, making it impossible to efficiently mix and stir the excavated soil and solidification agent.

For this purpose, for example, Japanese Patent Publication No. Sho 58-29374 proposes a mixing and stirring blade device having co-rotation prevention blades having a diameter larger than the excavation diameter of the excavation blade.

In this prior art, since the co-rotation prevention blades are fixed to the excavation wall surface, force is required for press-fitting during excavation, and there is resistance due to this force. Furthermore, it has been proposed that the excavation shafts are doubled, and excavation blades are attached to each excavation shaft, and the excavation blades are rotated in opposite directions. This double tube type is
Structures tend to be complex.

[Problems to be Solved by the Invention] An object of the present invention is to provide a mixing and stirring device for a ground improvement machine that can efficiently stir soil and hardening agent.

[Means to solve the problem] In order to solve the above problem, the following measures are taken.

a rotationally driven excavation shaft (1); an excavation blade (3) provided on the excavation shaft (1) for excavating and roughening the ground;
(9), a connecting part (4) formed on a part of the excavation shaft (1), a boss (5>) for engaging and disengaging from this connecting part (4), and this boss (5) a stopper (8) provided below the connecting portion (4) and on the excavation shaft (1) to catch the lowering of the boss (5); This is a mixing and stirring device for a soil improvement machine consisting of:

It is even better if a drilling bit (10) is provided at the lower end of the drilling shaft (1>).

[Operation] The excavator $l111 is driven to rotate and at the same time pressurized force is applied to push it into the ground. The tip bit 10, the co-rotation prevention blade 7, and the excavation blade 3 are simultaneously rotationally driven and ground 12.
Excavate in a cylindrical shape and loosen the soil in the excavated hole]3.

Since the discharge port 14 is provided in the excavation blades 3 and 9, the solidifying agent is discharged onto the blade surface. In this state, the excavation shaft 1 is pulled up while being rotated in the opposite direction to that during excavation. By this pulling up, the boss 5 of the co-rotation prevention blade 7 is separated from the connecting shaft 4, collides with the stopper 8, and is stopped. Furthermore, if the rotation is continued while pulling up the excavation shaft 1, the co-rotation prevention blades 7 will only rise without rotating, while the excavation blades 39
While rotating, the improved soil pillars 15 are formed while discharging the solidification agent from the discharge port 14 and stirring the soil. At this time, the co-rotation prevention blade 7 does not rotate [Example] Hereinafter, an example of the present invention will be described according to the drawings.

FIG. 1(a) is a front view showing a mixing stirring blade device,
1(b) is a cross-sectional view taken along line bb in FIG. A joint 2 for connecting the lower end of a rod 11 (see Figure 3) is fixed to the upper end of the excavation shaft 1.The rod 11 is fixed to a chuck of a ground improvement machine (not shown) and rotates. and driven in the axial direction.

An excavating blade 3 is fixed to the upper part of the excavating shaft 1 at an angle of 180 degrees by welding. A connecting portion 4 having a hexagonal cross section is formed on the outer periphery of the excavating shaft 1 at the lower part of the excavating blade 3.

The connecting portion 4 is formed into a hexagonal column shape in the axial direction of the excavation shaft 1. A boss 5 is inserted into the outer periphery of the connecting portion 4. A connecting hole 6 having a hexagonal cross section is formed in the inner periphery of the boss 5 to be connected to the connecting portion 4 . Two anti-rotation wings 7 are connected to the outer periphery of the boss 5 at an angle of 180 degrees. A stopper 8 is provided at the bottom of the connecting portion 4.
is integrally fixed to the excavation shaft 1.

Further, two excavating blades 9 are fixed to the excavating shaft 1 at the lower end of the stopper 8 by welding at an angle of 180 degrees. Two tip bits 10 are fixed to the bottom end of the drilling shaft 1. The tip bit 10 is used mainly to drill a hole in the center of the ground improvement column. FIG. 2(a) shows the state in which the stirring blade device is suspended, and the co-rotation prevention blade 7 falls and the stopper 8
Shows the status on the page. The excavation shaft 1 at the position where the co-rotation prevention blade 7 is placed on the stopper 8 has a cylindrical shape. Therefore, the excavation shaft 1 and the boss 5 of the co-rotation prevention blade 7 are not connected to each other.

Dan m Pressure Gong"L Below, a soil improvement method using a mixing and stirring device of a soil improvement machine will be explained. Figure 3 is a cross-sectional view showing how the excavation progresses and the ground is loosened. An excavation shaft 1 is connected to a rod 11 of a soil improvement machine via a joint 2. The excavation shaft 1 rotates at the same time as the rod 11 is rotationally driven. Drilling shaft 1
As the rod 11 rotates, a soil improving machine applies pressure to the rod 11 and pushes it into the ground.

The tip pit 10, the co-rotation prevention blade 7, and the excavation blade 3 are driven to rotate simultaneously to excavate the ground 12 in a cylindrical shape to form the excavation hole 1.
Massage the soil within 3. When the excavation hole 13 reaches the set depth, the rotation and feeding of the excavation shaft 1 is stopped. rod 11
A supply path is formed in which a solidifying agent such as cement slurry is supplied under pressure. Assimilate pressurized from this supply path is discharged from the discharge port 14.

Since the discharge port 14 is provided in the excavation blades 3 and 9, the solidifying agent is discharged onto the blade surface. In this state, the excavation shaft 1 is pulled up while being rotated in the opposite direction to that during excavation. By this pulling up, the boss 5 of the co-rotation prevention blade 7 is separated from the connecting shaft 4, collides with the stopper 8, and is stopped. Furthermore, when the excavation shaft 1 continues to rotate while being pulled up, the co-rotation prevention blades 7 do not rotate and only rise, while the excavation blades 3°9 rotate while discharging the solidifying agent from the discharge port 14. Improved soil pillars 15 are formed while stirring the soil.

Since the co-rotation prevention blade 7 does not rotate, it does not integrally stir the soul of the excavated improved soil. As a result, the excavated soil and solidification agent are well mixed.

[Other Examples] The connecting portion 4 in the above example had a hexagonal cross section. However, as can be understood from the above description, a pentagonal, quadrilateral or spline connection may also be used. Further, these may be tapered and used in combination with tapered bonding. Further, although the excavation blade 3 in the above embodiment has two blades, it may have two or more blades. Further, in the above embodiment, there are two stages of excavation blades 3.9 and one stage of co-rotation prevention blades, but the number of these stages may be any number as necessary.

[Effects of the Invention] As detailed above, the present invention efficiently excavates or massages the ground during ground excavation, and rotates the soil so that it does not rotate together with the excavation blade while injecting the hardening agent. Since it stops, the soil and solidification agent can be mixed efficiently.

[Brief explanation of drawings]

Figure 1<a) is a front view of the mixing agitation blade device of the soil improvement machine;
FIG. 1(b) is a cross-sectional view taken along line bb in FIG. 1(a), FIG. 2(a) is a diagram showing the state when the co-rotation prevention blade is lowered,
Figure 2(b) is a cross-sectional view taken along line bb in Figure 2(a), Figure 3 is a cross-sectional view showing the state during excavation, and Figure 4 is a cross-sectional view showing the state in which solidifying agent is being injected. It is a diagram. 1...Drilling shaft, 3.9...Drilling blade, 4...Connection part,
6 Connecting hole, 8... Stopper, 1o... Drilling bit Patent applicant Yoshida Iron Works Co., Ltd. Managing Director Hajime Tomisaki Figure 3 Figure 4 Figure 1 (b) Figure 2

Claims (1)

[Claims] 1. Rotationally driven excavation shaft (1) and this excavation shaft (1)
Excavation blades (3
), (9), a connecting part (4) formed on a part of the excavation shaft (1), a boss (5) for engaging and disengaging from this connecting part (4), and this boss ( a stopper (8) provided on the outer circumference of the boss (5) and a stopper (8) provided below the connecting portion (4) and on the excavation shaft (1) to prevent the boss (5) from descending. ) A mixing and stirring device for a soil improvement machine. 2. The mixing agitation blade device for a ground improvement machine according to claim 1, characterized in that a drilling bit (10) is provided at the lower end of the excavation shaft (1).