JP2795426B2 - Mixing and stirring blade device of ground improvement machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mixing and stirring blade device of a ground improvement machine for improving soft ground and the like. More specifically, the present invention relates to a mixing and stirring blade device of a ground improvement machine for forming a columnar consolidated body in the ground by mechanically mixing and solidifying soil and a solidifying agent in a soil improvement work or the like.

[0002]

2. Description of the Related Art As one of soft ground improvement works, there is a deep mixing treatment method, which is roughly classified into an injection stirring method and a mechanical stirring method. Among them, the mechanical stirring method uses an improved machine having a drilling shaft provided with a drilling blade and a stirring blade, and the drilling shaft is rotated and excavated by a drilling mechanism. The excavated soil is forcibly stirred while discharging the solidifying agent to form a columnar solidified body in the ground.

[0003] However, this type of soil improvement machine can be easily applied to sandy soil or silt-based soil because the solidifying agent and the soil are forcibly mixed and stirred, but the clay is particularly suitable for clay. In the case of hard cohesive soil, the ground to be improved and the stirring blades may not be able to efficiently mix and agitate the excavated soil and the solidifying agent while the excavated soil and the stirring blades co-rotate.

[0004] For this reason, for example, Japanese Patent Publication No. 58-29374.
Japanese Patent Application Publication No. JP-A-2005-64131 proposes a mixing and stirring blade device having a co-rotation prevention blade having a diameter larger than the drilling diameter of the drilling blade.

In this prior art, since the anti-corotating blade is fixed to the excavation wall surface, a force for press-fitting is required during excavation, and there is resistance due to this. In addition, there has been proposed an apparatus in which a digging wing is doubled, a digging wing is attached to each digging axis, and the digging wings are rotated in opposite directions. However, the structure of this double tube type tends to be complicated.

Accordingly, the present applicant has disclosed in Japanese Patent Application Laid-Open No. Hei 5-13292.
No. 6 proposes a mixing and stirring blade apparatus which improves these points. According to this device, the co-rotation prevention wing rotates integrally with the excavation shaft during excavation engaged with the connection portion, and separates from the connection portion and is eccentric from the axis of the excavation shaft. It rotates relative to the shaft and digs into the excavation wall due to eccentricity.

[0007] However, the one described in Japanese Patent Application Laid-Open No. 5-132926 discloses the movement of the boss of the co-rotation prevention wing from the connecting portion, which is coaxial with the excavation axis, to the eccentric position, that is, the co-rotation prevention wing is connected to the excavation shaft. The transition from the integrally rotating excavation state to the pulling state in which the excavation axis freely rotates with respect to the excavation axis may not be performed smoothly.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a mixing and stirring blade device for a ground improvement machine capable of efficiently stirring soil and a solidifying agent.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a mixing and stirring blade device for a ground improvement machine in which an anti-corotating blade smoothly transitions from an excavated state to a pulled state.

[0010]

Means for Solving the Problems To solve the above-mentioned problems, the following means are adopted.

According to the present invention, a drilling shaft driven by rotation (1) is provided.
A drilling wing (2) provided on the drilling shaft (1) for drilling, kneading and stirring the ground; and a part of the drilling shaft (1) with respect to the drilling shaft (1). An eccentric shaft (1b) provided eccentrically, a boss (5) rotatably provided on the eccentric shaft (1b) and movable between an ascending position and a descending position, and an outer periphery of the boss (5) A counter-rotating wing (7) provided on the excavation shaft (1);
An engaging portion provided on the boss, wherein the first engaging portion is provided when the boss is at the raised position.
4) a second engaging portion (15) which is disengaged from the first engaging portion (14) when in the lowered position.
The axis (C ₂ ) of the eccentric shaft (1b) is eccentric with respect to the axis (C ₁ ) of the excavating shaft (1), and the boss (5) is positioned with respect to the axis of the boss (5) itself. The eccentric shaft (1b) is a mixing and stirring device of a ground improvement machine inserted into the boss hole (6).

The boss (5) is provided eccentrically with respect to the axis of the eccentric shaft (1a).

The first engaging portion is a first claw (14) extending in the axial direction from the excavation shaft (1), and the second engaging portion is a first claw extending in the axial direction from the boss (5). Two claws (15).

The first and second engagement portions (14, 15)
In each case, a pair is provided at an angular interval of 180 degrees.

[0015]

During excavation, the boss 5 is in the raised position, the first engagement portion 14 and the second engagement portion 15 are engaged, and the co-rotation prevention blade 3 rotates integrally with the excavation shaft. When the excavating shaft is pulled up, the boss 5 descends, and the boss 5 can rotate eccentrically around the axis of the excavating shaft 1. For this reason, a radial shift occurs between the rotation locus of the anti-corotating blade 3 and the rotation locus of the excavation blade 2,
The tip of the anti-corotating wing bites into the hole wall of the borehole. As a result, the excavated soil is subjected to a shearing action, and co-rotation of the excavated soil is prevented.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are front views showing a mixing and stirring blade device in an excavated state and a pulled state, respectively, and FIG.
4 is a sectional view taken along line BB of FIG. 2, FIG. 5 is a sectional view taken along line CC of FIG. 2, and FIG. 6 is a sectional view taken along line CC of FIG. It is sectional drawing along the -D line.

The excavating shaft 1 is a central shaft on which upper and lower excavating wings 2 and 22 and an anti-corotating wing 3 are attached and driven to rotate. A hexagonal hole 4 is provided at the upper end of the excavation shaft 1 for connecting to a boring rod 16 via a pin. The upper end of the boring rod 16 is fixed to a chuck of a ground improvement machine, and a rotational force and an axial thrust are applied.

In this embodiment, the excavating shaft 1 is an upper excavating shaft 1.
a, an intermediate excavation shaft 1b and a lower excavation shaft 1c. The upper excavating shaft 1a and the intermediate excavating shaft 1b are formed integrally, and the intermediate excavating shaft 1b and the lower excavating shaft 1c are formed separately. A plurality of bits 17 are provided at the tip of the lower excavation shaft 1c.

The upper excavating shaft 1a and the lower excavating shaft 1c
Have a common axis C ₁ and an axis C ₂ of the intermediate excavation shaft 1b.
Is eccentric to the axis C _1. That is, the intermediate portion excavating shaft 1b forms an eccentric shaft.

In this embodiment, two excavating blades 2 and 22 are provided, respectively, and an upper excavating shaft 1a and a lower excavating shaft 1c are provided.
And is fixed by welding at an angle of 180 degrees. As shown in FIG. 7 or FIG. 8, the drilling wings 2 and 22 are provided with a number of bits 18.

In this embodiment, two anti-corotating blades 3 are also provided, and are fixed to the boss 5 by welding. The boss 5 has a boss hole 6 eccentric to the axis of the boss itself. This boss hole 6 is inserted eccentric shaft 1b is, the boss 5 is rotatable about axis C ₂ of the eccentric shaft 1b, also is movable in the axial C ₂ direction.

A stopper ring 7 is provided on the outer periphery of the lower part of the eccentric shaft 1b. The lower end of the eccentric shaft 1b is inserted through a packing 9 into a hole 8 provided on the upper portion of the lower excavation shaft 1c. The stopper ring 7 is fixed to the lower excavation shaft 1c by a number of bolts 10, whereby the eccentric shaft 1b is fixed to the lower excavation shaft 1c.

The upper excavating shaft 1a, the eccentric intermediate excavating shaft 1b and the lower excavating shaft 1c are formed with passages 10a, 10b and 10c communicating with each other for supplying a solidifying agent. Of the passages, the passage 10 provided on the eccentric shaft 1b
b has a larger diameter than the other passages 10a and 10c in order to reduce the weight. The upper excavating shaft 1a and the lower excavating shaft 1c are provided with discharge ports 11 and 12 of the solidifying agent which communicate with the passages 10a and 10b, respectively.

A relatively thick flange 13 is provided at the boundary between the upper excavating shaft 1a and the eccentric shaft 1b. A pair of first engagement claws 14, which are first engagement portions, are provided on the lower surface of the flange 13. The first engagement claw 14, 14 extend downward along the axis C _1, and is provided at an angular interval of 180 degrees equidistant position from the axis C _1.

The boss 5 has the same diameter as the flange 13. On the upper surface of the boss 5, a pair of second
Engagement claws 15 are provided. Second engagement claw 15,
Reference numeral 15 extends upward along the axis of the boss 5 and is provided at an equal distance from the axis of the boss 5 at an angular interval of 180 degrees.

The boss 5 moves up and down between an upper position where its upper surface contacts the first engaging claw 14 and a lower position where its lower end contacts the stopper ring 7. When the boss 5 rotates relative to the eccentric shaft 1a within an angle range of 180 degrees at the raised position of the boss 5, the first engagement claws 14 and 14 and the second engagement claw 1
5 and 15 are engaged with each other.

The first engaging claws 14, 14 and the second engaging claws 15,
15, when the excavating shaft 1 rotates, the boss 5
That co-rotation preventing blade 3 rotates about axis C ₁ together with the drilling shaft 1 in the same direction. In this engagement state, the turning radius of the co-rotation prevention blade 3 is equal to the turning radius of the excavating blades 2 and 22. Chain line T ₁ of the FIG. 7 is a diagram showing a rotation trajectory of the time.

When the boss 5 is lowered to the lower position where it comes into contact with the stopper ring 7, the second engagement claws 15, 15 are disengaged from the first engagement claws 14, 14, and the boss 5 can rotate with respect to the eccentric shaft 1b. Becomes When the excavating shaft 1 rotates in this detached state,
Eccentric shaft 1b is rotated around the axis C _1, also rotates the eccentric around the axis line C ₁ of the boss 5 is eccentric relative to the axis C _2.

Accordingly, the anti-corotating wing 3 shows the motion trajectory shown in FIG. In FIG. 8, (a) is when the excavation axis 1 is rotated by 0 degrees,
(B) when rotated 90 degrees, (c) when rotated 180 degrees,
(D) is at the time of 270 degree rotation.

Here, focusing on the two corner portions of the co-rotation prevention blade 3, the first corner portion is located at the A ₀ position and the second corner portion is located at the B ₀ position at the time of 0 ° rotation. When the excavating shaft 1 rotates 90 degrees ((b)), the first corner portion becomes A
₁ position, the second corner is displaced B ₁ position. That is, in the xy plane coordinates shown in FIG. 8, the anti-corotating blade 2 is + dx _{1 in} the x direction and + dy _{1 in the} y direction from the position (a).
Displace.

When the excavating shaft 1 is rotated by 180 degrees ((c)), the first corner is displaced to the position A ₂ and the second corner is displaced to the position B ₂ . That is, the anti-corotation blade 2 is displaced by dx _{2 in the} x direction from the position (a).

When the excavating shaft 1 rotates 270 degrees ((d)), the first corner is displaced to the position A ₃ and the second corner is displaced to the position B ₃ . That is, the anti-corotation blade 2 is + dx _{1 in} the x direction and −dy _{1 in} the y direction from the position (a).
Displace.

When the excavating shaft 1 rotates 360 degrees, the co-rotation prevention wing returns to the position (a). Excavation axis 1 36
FIG. 9 shows the trajectories of the first and second corner portions accompanying the 0-degree rotation.

The ground improvement method using the mixing and stirring blade device of the above-described ground improvement machine will be described below. FIG. 1 shows how the excavation proceeds and the ground is rubbed. When the boring rod 16 is rotationally driven, the excavating shaft 1 is simultaneously rotated. The excavating shaft 1 is also given a thrust by a ground improvement machine via a rod 16 and is pushed into the ground.

The rotation of the excavation shaft 1 causes the excavation wings 2, 22 and the bit 17 to rotate, excavating the ground into a columnar shape, and
The soil in 0 is rubbed. At this time, the first engagement claws 14,
14 and the second engagement claws 15, 15 are engaged with each other, and the co-rotation prevention blade 3 rotates integrally with the excavation shaft 1.

When the borehole 20 reaches a predetermined depth, the rotation and feed of the drilling shaft 1 are stopped. Passages 10a, 10b,
A pressurized solidifying agent such as cement slurry or the like is supplied through 10c and is discharged from discharge ports 11 and 12.

Next, as shown in FIG. 2, the excavating shaft 1 is pulled up while rotating the excavating shaft 1 in the same direction as the excavation or in the opposite direction while discharging the solidifying agent. As a result, the excavating blades 2 and 22 rotate, and the excavated soil and the solidifying agent are stirred and mixed, so that an improved columnar compact is formed in the ground.

When the excavating shaft 1 is raised, the boss 5 of the co-rotation prevention blade 3 is lowered and supported by the stopper ring 7. As a result, the first engagement claws 14, 14 and the second
The engagement with the engagement claws 15, 15 is released, and the co-rotation prevention wing 3 performs the eccentric movement shown in FIG. As a result, the tip of the co-rotation prevention blade 3 bites into the hole wall of the excavation hole 20.

Further, if the drilling shaft 1 is kept rotating while being lifted, the co-rotation preventing blade 7 rotates but bites into the hole wall of the drilling hole 20, so that there is a gap between the excavating blades 2, 22 and the co-rotation preventing blade 3. The excavated soil is subjected to a shearing action to prevent co-rotation of the excavated soil, and the excavated soil and the solidifying agent are sufficiently stirred and mixed.

[Other Embodiments] In the above-described embodiment, a pair of first and second engaging claws 14 and 15 are provided, but both claws may be one. However, for stable and integral rotation of the anti-corotating blade 3 with the excavation shaft 1 during excavation, it is preferable to provide a pair. Further, the number of claws may be three or more.

Although the hole 6 of the boss 5 is provided eccentrically from the center axis of the boss, this is for equalizing the lengths of the two anti-corotating wings 3, and the axes may be aligned.

Although the two excavating wings 2 and 22 and the co-rotation preventing wing 3 are provided, one or three or more may be provided. Further, the number of stages may be plural.

[0043]

As described in detail above, the present invention excavates or excavates the ground efficiently during excavation of the ground, and excavates by the co-rotation prevention wings biting into the wall of the excavation hole during the injection of the solidifying agent. The soil is prevented from rotating together with the excavation wing, and the excavated soil and the solidifying agent can be efficiently stirred. In addition, since the boss of the co-rotation prevention blade moves up and down only on the eccentric shaft, the transition from the excavation state to the pulled-up state of the excavation axis for injecting the solidifying agent is smoothly performed.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing a mixing and stirring blade device in an excavated state.

FIG. 2 is a partially cutaway front view showing the mixing and stirring blade device in a pulled state.

FIG. 3 is a sectional view taken along line AA of FIG. 1;

FIG. 4 is a sectional view taken along the line BB of FIG. 2;

FIG. 5 is a sectional view taken along line CC of FIG. 2;

FIG. 6 is a sectional view taken along line DD of FIG. 1;

FIG. 7 is a diagram showing the rotation trajectory of the excavation wing and the co-rotation prevention wing in an excavation state.

FIG. 8 is a diagram showing the trajectories of the excavating wing and the co-rotation preventing wing in the pulled up state.

FIG. 9 is a diagram showing rotation trajectories of two corner portions of the co-rotation prevention blade.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Excavation axis 2 ... Excavation wing 3 ... Co-rotation prevention wing 5 ... Boss 6 ... Boss hole 7 ... Stopper ring 11, 12 ... Discharge port 14 ... 1st engagement claw 15 ... 2nd engagement claw 20 ... Excavation hole

Claims (4)

(57) [Claims] 1. A rotary driven drilling shaft (1), wherein provided on the drilling axis (1), excavating the ground, crumpling construed and the drilling blade for stirring (2), said drilling shaft ( eccentric shaft provided eccentric to the drilling axis to a portion of 1) (1) and (1b), provided to be movable between a lowered position and rotatable and a raised position in the eccentric shaft (1b) boss (5) and, co-rotation preventing blades provided on the outer periphery of the boss (5) (7)
A first engagement portion (14) provided on the excavation shaft (1); and a first engagement portion (14) provided on the boss (5) , wherein the boss (5) is in the raised position. 14) and a second engaging portion (15) which is disengaged from the first engaging portion (14) when in the lowered position. The axis (C ₂ ) of the eccentric shaft (1b) is , said decentered with respect to the axis (C ₁₎ of the drilling shaft (1), the boss (5), relative to the boss (5) its own axis
An eccentric boss hole (6), wherein the eccentric shaft (1b) is inserted into the boss hole (6);
Mixing and stirring apparatus that soil improvement machine. 2. A mixing and agitating device for a ground improvement machine according to claim 1, wherein said boss (5) is provided eccentrically with respect to an axis of said eccentric shaft (1b) . 3. The second engaging portion according to claim 1, wherein the first engaging portion (14) is a first claw (14) extending from the excavating shaft (1) in an axial direction thereof.
A mixing and stirring device for a ground improvement machine, wherein (15) is a second claw (15) extending in the axial direction from the boss (5). 4. A any one of claims 1 to 3, wherein the first, second engagement portions (14, 15), both 18
A mixing and stirring device for a ground improvement machine, wherein a pair is provided at an angular interval of 0 degrees.