JP6945355B2 - Ground agitator - Google Patents

Description

The present invention relates to a ground agitator.

Conventionally, a ground improvement method is widely known in which a solidifying agent is discharged into the ground and stirred to improve the properties of the ground. In this ground improvement method, a ground stirring device that stirs and mixes the ground and the solidifying agent is used. This ground agitator extends, for example, an excavation shaft that rotates around an axis, an excavation blade that extends outward from the tip of the excavation shaft, and an excavation blade that extends outward from the excavation shaft above the excavation blade. It mainly has a stirring blade. When improving the ground using this ground agitator, the excavation shaft is rotated around the axis and penetrates into the ground, and the ground is excavated in a columnar shape by the excavation blade provided at the tip of the excavation shaft. Further, a solidifying agent such as cement milk is discharged from the tip of the excavation shaft or the like to the ground (earth and sand) excavated by the excavation blade. This solidifying agent is agitated and mixed with earth and sand by a stirring blade provided above the excavation blade, and a columnar improved ground (improved body) is formed as the solidifying agent hardens.

Further, at present, as a ground agitator, there is a multi-axis type ground agitator provided with a plurality of excavation shafts. In this multi-axis type ground agitator, based on the difference in the pitch between the axes, the tangential type in which the improved bodies adjacent to each other are in contact with each other and the improved bodies adjacent to each other partially overlap each other. It is classified into a wrap type and a separation type in which improved bodies adjacent to each other are separated from each other. However, the current implementation work is generally performed in a tangent circle type or a wrap type, and is rarely performed in a separated type. This is due to the following reasons.

First, in the multi-axis type ground agitator, in the case of the separation type, the separation portion is not agitated and may be unimproved. Further, in the multi-axis type ground agitator, a plurality of excavation shafts are connected by a connecting member (so-called connecting band) so that shaft shake does not occur at the time of drilling. However, since this connecting member is penetrated into the separated portion, it causes a large penetration resistance. In this regard, in solving these problems, the proposal of Patent Document 1 is diverted, for example, an excavation blade or a stirring blade peculiar to the connecting member is provided to compensate for the insufficiency of excavation / stirring in the separated portion. Can be considered. However, if a unique excavation blade or stirring blade is provided, the ground stirring device becomes extremely complicated.

Japanese Unexamined Patent Publication No. 7-3774

A main problem to be solved by the present invention is to provide a simple ground agitator that does not cause the separated portion to be agitated and unimproved even when the multi-axis type ground agitator is a separated type. It is in.

The means to solve the above problems are
It is provided with a plurality of excavation shafts that rotate around the axis, a connecting member that connects the plurality of excavation shafts, and a lower auxiliary member that projects downward from the connecting member.
The lower auxiliary member has a ground cut portion and a ground diffusion portion interposed between the ground cut portion and the connecting member.
The ground cut portion extends in a direction in which the tip edge extends in a direction orthogonal to the extending direction of the connecting member.
The ground diffusing portion has a width about the extending direction of the connecting member is spread toward the coupling member from the ground notches,
As the connecting member, an upper connecting member and a lower connecting member are provided.
The excavation shaft is provided with a second stirring blade located between the upper connecting member and the lower connecting member.
The lower auxiliary member projects downward from the lower connecting member, and the lower auxiliary member protrudes downward.
A central auxiliary member for connecting the upper connecting member and the lower connecting member is provided.
The width of the central auxiliary member with respect to the extending direction of the connecting member increases from the central portion in the vertical direction toward both ends in the vertical direction.
It is a ground agitator characterized by this.

According to the present invention, even when the multi-axis type ground agitator is a separated type, it is a simple ground agitator that does not cause the separated portion to be agitated and not improved.

It is a front view of the ground agitator. It is a side view of the ground agitator. (1) is a view taken along the line XX of FIG. 2, and (2) is a view taken along the line YY of FIG. It is a side view of an auxiliary member. It is explanatory drawing which shows the movement of the ground (earth and sand).

Next, a mode for carrying out the invention will be described. This embodiment is an example of the present invention. The present invention is not limited to the scope of this embodiment.

(Excavation shaft)
As shown in FIGS. 1 and 2, the ground agitator 1 of the present embodiment is a multi-axis type ground agitator having a plurality of excavation shafts 10 (two in the illustrated example). The excavation shaft 10 receives power from a power swivel or the like (not shown), moves in the vertical direction, and rotates around the axis. The excavation shafts 10 adjacent to each other rotate in opposite directions.

(Excavation blade)
The tip of the excavation shaft 10 is provided with an excavation blade 31 including one excavation blade 31a and the other excavation blade 31b. The excavation blade 31a on the one hand and the excavation blade 31b on the other hand have a semi-spiral shape centered on the excavation shaft 10. The excavation blade 31a on the one hand and the excavation blade 31b on the other hand are arranged so as to be point-symmetrical with respect to the excavation shaft 10. The ground G is excavated by the excavation blade 31a on the one hand and the excavation blade 31b on the other hand.

A plurality of excavation bits 31x (three in each of the illustrated examples) projecting downward are provided at the lower ends of the excavation blade 31a on the one hand and the excavation blade 31b on the other side. The excavation bid 31x allows the excavation of the ground G to be performed smoothly and quickly.

(Excavation wing)
The excavation shaft 10 near the upper end of the one excavation blade 31a and the other excavation blade 31b is provided with an excavation blade 35 composed of one excavation blade 35a and the other excavation blade 35b. The excavation blade 35a on the one hand and the excavation blade 35b on the other hand have a plate shape extending outward from the outer peripheral surface 10a of the excavation shaft 10, respectively. The excavation blade 35a on the one hand and the excavation blade 35b on the other hand are arranged so as to be point-symmetrical with respect to the excavation shaft 10. The excavation blade 35a on the one hand and the excavation blade 35b on the other hand agitate the ground G as it is excavated.

On the one hand excavation blade 35a and the other excavation blade 35b, based on the rotation direction (rotation A) at the time of penetration, the portion on the front side (lower edge portion) is larger than the portion on the rear side (upper edge portion). The inclination of a predetermined angle located below is, for example, 40 to 50 °. By this inclination, for example, the propulsive force of the ground stirring device 1 at the time of penetration can be obtained.

On the lower edge of the distal side of the one excavation blade 35a and the other excavation blade 35b, a plurality of excavation bits 35x protruding along the inclination of the one excavation blade 35a and the other excavation blade 35b, respectively (3 in the illustrated example). Book) is provided. The excavation bid 35x enables smooth and rapid excavation of the ground G.

The one excavation blade 35a and the other excavation blade 35b are arranged so that their lower edges are parallel to the lower end edges of the one excavation blade 31a and the other excavation blade 31b. However, the one excavation blade 35a and the other excavation blade 35b extend outward from the one excavation blade 31a and the other excavation blade 31b.

(Linear stirring blade)
The excavation shaft 10 above the excavation blade 35a and the other excavation blade 35b is provided with a straight stirring blade 41 composed of a linear stirring blade 41a on the one hand and a linear stirring blade 41b on the other side. The linear stirring blade 41a on the one hand and the linear stirring blade 41b on the other hand have a plate shape extending outward from the outer peripheral surface 10a of the excavation shaft 10, respectively. The linear stirring blade 41a on the one hand and the linear stirring blade 41b on the other hand are arranged so as to be point-symmetrical with respect to the excavation shaft 10. The ground (earth and sand) G excavated by the excavation blade 31 and the excavation blade 35 is agitated by the linear stirring blade 41a on the one hand and the linear stirring blade 41b on the other hand.

The linear stirring blade 41a on the one hand and the linear stirring blade 41b on the other side are also inclined in the same manner as the excavation blade 35a on the one hand and the excavation blade 35b on the other side. Specifically, based on the rotation direction (rotation A) at the time of penetration, the portion on the front side (lower edge portion) is located below the portion on the rear side (upper edge portion) at a predetermined angle. The inclination is, for example, 40 to 50 °. By this inclination, for example, the propulsive force of the ground stirring device 1 at the time of penetration can be obtained.

The linear stirring blade 41a and the other linear stirring blade 41b have, for example, 30 to 60 ° in a plan view so that their lower edges are not parallel to the lower edges of the one drilling blade 35a and the other drilling blade 35b. They are arranged so that they intersect at an angle. Further, the one linear stirring blade 41a and the other linear stirring blade 41b extend slightly inward from the one excavation blade 35a and the other excavation blade 35b.

On the one hand, the linear stirring blade 41a and the other linear stirring blade 41b have a substantially rectangular cross section along the extending direction of the linear stirring blade 41a and the other linear stirring blade 41b, respectively, protruding downward on the drilling shaft 10 side of the lower surface. A convex square member 41x is provided. The convex lumber 41x reduces the resistance when the ground agitator 1 penetrates into the ground G.

(Lower shear plate)
A lower shear plate 51 is provided on the excavation shaft 10 above the linear stirring blade 41a and the other linear stirring blade 41b. The lower shear plate 51 includes one lower shear plate 51a, the other lower shear plate 51b, and a lower connecting member 52. On the other hand, the lower shear plate 51a has a plate shape extending outward from one of the excavation shafts 10. The other lower shear plate 51b has a plate shape extending outward from the other excavation shaft 10. The lower connecting member 52 is a member that connects the pair of excavation shafts 10. The lower shear plate 51a, the lower shear plate 51b, and the lower connecting member 52 are arranged in a straight line.

The lower shear plate 51a and the other lower shear plate 51b are not inclined like the one linear stirring blade 41a and the other linear stirring blade 41b. Both surfaces of the lower shear plate 51a and the other lower shear plate 51b face the rotational direction. The lower shear plate 51a and the other lower shear plate 51b are not fixed to the outer peripheral surface 10a of the excavation shaft 10 and are rotatable. Specifically, a tubular body 51c that is rotatable around the axis is provided on the outer peripheral surface 10a of the excavation shaft 10, and one lower shear plate 51a and the other lower shear are provided on the outer peripheral surface of the tubular body 51c. The plate 51b is fixed. The tubular body 51c is prevented from moving in the axial direction by a pair of flanges 51d and 51d protruding from the outer peripheral surface 10a of the excavation shaft 10. Since the one lower shear plate 51a and the other lower shear plate 51b are rotatable in this way, the excavated ground G is gently sheared and integrally rotates at all parts in the axial direction. Is slowly prevented.

(Lower stirring blade / Upper stirring blade)
The excavation shaft 10 above the lower shear plate 51 is provided with a lower stirring blade 21 composed of one lower stirring blade 21a and the other lower stirring blade 21b. The excavation shaft 10 above the lower stirring blade 21 is provided with an upper stirring blade 25 including one upper stirring blade 25a and the other upper stirring blade 25b. The lower stirring blade 21 and the upper stirring blade 25 are different in that the lower stirring blade 21 bends in one direction in the rotation direction and the upper stirring blade 25 bends in the other direction in the rotation direction. However, both stirring blades 21 and 25 basically have the same structure. Therefore, in the following, the lower stirring blade 21 will be mainly described, and the upper stirring blade 25 will be supplementarily described.

The one lower stirring blade 21a and the other lower stirring blade 21b extend outward from the outer peripheral surface 10a of the excavation shaft 10 as shown in FIG. 3 (2). The lower stirring blade 21a and the other lower stirring blade 21b are arranged so as to be point-symmetrical with respect to the excavation shaft 10. The lower stirring blade 21a on the one hand and the lower stirring blade 21b on the other side are plate-shaped, and are inclined in the same manner as the excavation blade 35a on the one hand and the excavation blade 35b on the other side. More specifically, based on the rotation direction (rotation A) at the time of penetration, the inclination of a predetermined angle where the front side portion (lower edge portion) is located below the rear side portion (upper edge portion). However, for example, it is inclined by 40 to 50 °. By this inclination, for example, the propulsive force of the ground stirring device 1 at the time of penetration can be obtained. The ground G and the like excavated by the excavation blade 31 and the excavation blade 35 are agitated by the lower stirring blade 21a and the other lower stirring blade 21b.

The lower stirring blade 21a and the other lower stirring blade 21b are shaped to bend in one (rearward) direction in the rotational direction toward the outside. Therefore, the function of discharging the excavated ground G and the like is exhibited, and uneven stirring in the radial direction is surely prevented. Here, "bending" is a concept that includes not only being curved, but also being bent at one or more than two places, and being a combination of bending and bending. However, it is preferable that the one lower stirring blade 21a and the other lower stirring blade 21b have a bent shape. In the example shown in FIG. 3, the stirring blades 21a, 21b, 25a, and 25b are bent at two places, respectively (the bent portion is indicated by reference numeral 21p).

The upper stirring blade 25a and the other upper stirring blade 25b have basically the same structure as the one lower stirring blade 21a and the other lower stirring blade 21b. However, as shown in FIG. 3 (1), the difference is that one lower stirring blade 21a and the other lower stirring blade 21b bend in a different direction (the other). When the lower stirring blades 21 and the upper stirring blades 25 located above and below are bent in different directions, the "other" exerts the scraping function when the "one" exerts the payout function. Therefore, the agitation performance in the radial direction of the excavated ground G and the like is improved.

The upper stirring blade 25a and the other upper stirring blade 25b, and the one lower stirring blade 21a and the other lower stirring blade 21b may be arranged so as to extend in the same direction from the excavation shaft 10. However, it is preferable to arrange them so as to extend in different directions, and it is more preferable to arrange them so as to extend in the orthogonal direction as shown in the illustrated example.

(Upper shear plate)
An upper shear plate 55 is provided on the excavation shaft 10 between the lower stirring blade 21 and the upper stirring blade 25. The upper shear plate 55 has the same structure as the lower shear plate 51 described above. Specifically, the upper shear plate 55 includes one upper shear plate 55a, the other upper shear plate 55b, and an upper connecting member 53. On the other hand, the upper shear plate 55a has a plate shape extending outward from one of the excavation shafts 10. The other upper shear plate 55b has a plate shape extending outward from the other excavation shaft 10. The upper connecting member 53 connects a pair of excavation shafts 10. One upper shear plate 55a, the other upper shear plate 55b, and the lower connecting member 52 are arranged in a straight line. The upper connecting member 53 and the lower connecting member 52 form a connecting member of the ground stirring device 1. The upper shear plate 55 gently shears the excavated ground G, and gently prevents the excavated ground G from rotating integrally at all parts in the axial direction.

(Second linear stirring blade)
The excavation shaft 10 above the upper shear plate 55 is provided with a second straight stirring blade 45 composed of a second one-sided linear stirring blade 45a and a second other linear stirring blade 45b. The second one-sided linear stirring blade 45a and the second other linear stirring blade 45b also have the same structure as the (first) one-sided linear stirring blade 41a and the other linear stirring blade 41b described above. The excavation blade 31 and the ground G excavated by the excavation blade 35 are agitated by the second linear stirring blade 45a and the second linear stirring blade 45b. Reference numeral 45x is a convex lumber.

(Axle shake prevention pin)
The tip surface of the excavation shaft 10 is provided with a shaft shake prevention pin 70 that projects toward the front (downward). The ground agitation device 1 of the present embodiment is configured to agitate the ground G (earth and sand) excavated by the lower agitation blade 21 and the upper agitation blade 25 in the radial direction as well. Therefore, there is a possibility that shaft shake may occur with stirring, especially when the excavation shaft 10 is penetrated. However, in the ground agitation device 1 of the present embodiment, since the excavation and agitation are performed in a state where the shaft shake prevention pin 70 is stuck in the ground G that has not been excavated, the shaft shake is prevented.

(Auxiliary member)
In the ground stirring device 1 of this embodiment, the pair of shear plates 51 and 55 are provided with the auxiliary member 80. As shown in FIGS. 1 and 4, the auxiliary member 80 is mainly composed of the lower auxiliary member (81, 82), the central auxiliary member 83, and the upper auxiliary member 84.

The lower auxiliary members (81, 82) project downward from the lower connecting member 52. The lower auxiliary members (81, 82) mainly consist of the ground cut portion 81 and the ground diffusion portion 82.

The ground cut portion 81 extends in a direction in which the tip edge (lower end edge) is orthogonal to the extending direction of the lower connecting member 52 (in FIG. 4, it is simply indicated as "orthogonal direction"). .. When the ground agitation device 1 is penetrated into the ground G, particularly when the separation type ground agitation device 1 is penetrated, a large load is applied from the ground G to the connecting members 52 and 53. However, in the ground stirring device 1 of the present embodiment, the load is greatly reduced by the ground cutting portion 81. The ground cut portion 81 can be formed of, for example, a commercially available claw used in a backhoe. In this embodiment, as shown in FIG. 4, the ground cut portion 81 is formed by providing two backhoe claws so that the tip edges are in series.

The ground diffusion portion 82 is interposed between the ground cut portion 81 and the lower connecting member 52. The ground diffusion portion 82 is configured so that the width of the lower connecting member 52 with respect to the extending direction increases from the ground notch 81 toward the lower connecting member 52. According to the lower auxiliary members (81, 82) of the present embodiment thus formed, as shown in (1) of FIG. 5, the ground G (earth and sand) cut by the ground cut portion 81 is the ground diffusion portion. In the process of ascending along 82, it diffuses toward the excavation shaft 10. Therefore, even in the separated type ground stirring device 1, there is no possibility that the separated portion is not agitated and is not improved.

However, according to this embodiment, the stirring of the separated portion can be performed more effectively.
That is, first, as a premise, the excavation shaft 10 is provided with a first stirring blade located below the lower connecting member 52, and in this embodiment, a linear stirring blade 41. Then, the lower auxiliary member (81, 82) is assumed to project to the side of the first stirring blade (straight stirring blade 41). According to this form, the ground G (earth and sand) agitated by the linear stirring blade 41 is diffused toward the lower auxiliary members (81, 82), and the diffused earth and sand is cut by the ground cut portion 81. It rises along the ground diffusion portion 82 together with the earth and sand, and further diffuses toward the excavation shaft 10. Therefore, the ground (earth and sand) will be diffused more strongly.

Next, the central auxiliary member 83 will be described. The central auxiliary member 83 is a member that connects the upper connecting member 53 and the lower connecting member 52. The upper connecting member 53 and the lower connecting member 52 are integrated by the central auxiliary member 83, and the strength of the connecting members 52 and 53 is increased. As a result, the misalignment of the excavation shaft 10 is more effectively prevented.

The central auxiliary member 83 of the present embodiment has the following configuration in order to further improve the stirring efficiency of the ground G (earth and sand) at the separated portion.
First, as a premise, the excavation shaft 10 is provided with a second stirring blade located between the upper connecting member 53 and the lower connecting member 52, and the lower stirring blade 21 in this embodiment. Then, the width of the central auxiliary member 83 with respect to the extending direction of the connecting members 52 and 53 is widened from the central portion in the vertical direction toward both end portions in the vertical direction (connecting members 52 and 52). According to this form, as shown in (2) of FIG. 5, the ground G (earth and sand) discharged by the lower stirring blade 21 heads toward the connecting members 52 and 53 along both side surfaces of the central auxiliary member 83. Further, in this process, it is diffused toward the excavation shaft 10. Therefore, the ground G (earth and sand) is effectively agitated at the separated portion. In this respect, as is clear from the above mechanism, in this embodiment, it is preferable to adopt a curved or bent type stirring blade having a function of discharging the ground G as the lower stirring blade 21.

In constructing the central auxiliary member 83 as described above, it is preferable to assemble the columnar members 83a and 83b in an X-shape in a front view to form a so-called truss structure (a structure assembled in a triangular aggregate form). According to this form, the above-mentioned effective stirring effect of the ground G (earth and sand) can be obtained. In addition, the strength of the central auxiliary member 83 is increased, and as a result, the misalignment of the excavation shaft 10 is more effectively prevented.

Next, the upper auxiliary member 84 will be described. The upper auxiliary member 84 projects upward from the upper connecting member 53. In the upper auxiliary member 84, as shown in FIG. 1, the tip edge (upper end edge) extends in the extending direction of the connecting members 52 and 53, and as shown in FIG. 4, the connecting members 52 and 53 extend. The width in the direction orthogonal to the direction is configured to widen from the tip edge toward the upper connecting member 53. When such an upper auxiliary member 84 is present, the resistance (load) by the connecting members 52 and 53 when the ground stirring device 1 is pulled out from the ground G is suppressed (reduced).

The present invention can be used as a ground agitator used in a ground improvement method or the like.

1 ... Ground agitator, 10 ... Excavation shaft, 10a ... Outer surface, 21 ... Lower stirring blade, 21a ... One lower stirring blade, 21b ... Other lower stirring blade, 25 ... Upper stirring blade, 25a ... One upper stirring blade Wings, 25b ... the other upper stirring blade, 31 ... excavation blade, 31a ... one excavation blade, 31b ... the other excavation blade, 31x ... excavation bit, 35 ... excavation blade, 35a ... one excavation blade, 35b ... the other excavation blade, 35x ... Excavation bit, 41 ... straight stirring blade, 41a ... one straight stirring blade, 41b ... other straight stirring blade, 41x ... convex square member, 45 ... second straight stirring blade, 45a ... second one straight Stirring blade, 45b ... second other linear stirring blade, 45x ... convex square member, 51 ... lower shear plate, 51a ... one lower shear plate, 51b ... other lower shear plate, 51c ... cylinder, 51d ... flange, 52 ... lower connecting member, 53 ... upper connecting member, 55 ... upper shear plate, 55a ... one upper shear plate, 55b ... other upper shear plate, 70 ... shaft shake prevention pin, G ... ground.

Claims (5)

It is provided with a plurality of excavation shafts that rotate around the axis, a connecting member that connects the plurality of excavation shafts, and a lower auxiliary member that projects downward from the connecting member.
The lower auxiliary member has a ground cut portion and a ground diffusion portion interposed between the ground cut portion and the connecting member.
The ground cut portion extends in a direction in which the tip edge extends in a direction orthogonal to the extending direction of the connecting member.
The ground diffusing portion has a width about the extending direction of the connecting member is spread toward the coupling member from the ground notches,
As the connecting member, an upper connecting member and a lower connecting member are provided.
The excavation shaft is provided with a second stirring blade located between the upper connecting member and the lower connecting member.
The lower auxiliary member projects downward from the lower connecting member, and the lower auxiliary member protrudes downward.
A central auxiliary member for connecting the upper connecting member and the lower connecting member is provided.
The width of the central auxiliary member with respect to the extending direction of the connecting member increases from the central portion in the vertical direction toward both ends in the vertical direction.
A ground agitator characterized by this. The excavation shaft is provided with a first stirring blade located below the connecting member.
The lower auxiliary member projects to the side of the first stirring blade.
The ground stirring device according to claim 1. The central auxiliary member has a truss structure in which columnar members are assembled in an X shape.
The ground stirring device according to claim 1 or 2. The second stirring blade has a plate shape, is inclined so that the front side portion is located below the rear side portion, and bends rearward in the rotational direction toward the outside. It has a bent shape,
The ground stirring device according to any one of claims 1 to 3. The upper connecting member is provided with an upper auxiliary member protruding upward.
The upper auxiliary member has a tip edge extending in the extending direction of the connecting member, and the width in a direction orthogonal to the extending direction of the connecting member increases from the tip edge toward the upper connecting member. ,
The ground stirring device according to any one of claims 1 to 4.

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