JP2018204171A - Ground agitation apparatus - Google Patents

Abstract

To provide a simple ground agitation apparatus causing no possibility of leaving separated parts not agitated and unimproved even in the case where a multi-shaft type ground agitation apparatus is to be a separated type.SOLUTION: A ground agitation apparatus 1 comprises multiple excavation shafts 10 rotating around a shaft center, a connection member 52 connecting the multiple excavation shafts 10, and a lower side auxiliary member protruding downward from the connection member 52. The lower side auxiliary member has a ground cutting part 81 and a ground diffusion part 82 set between the ground cutting part 81 and the connection member 52. A tip edge of the ground cutting part 81 is extended in the direction orthogonal to the extending direction of the connection member 52. A width of the ground diffusion part 82 related to the extending direction of the connection member 52 is expanded from the ground cutting part 81 toward the connection member 52.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a ground stirring device.

  Conventionally, a ground improvement method for improving the properties of the ground by discharging a solidifying agent into the ground and stirring it is widely known. In this ground improvement method, a ground agitating device that stirs and mixes the ground and a solidifying agent is used. This ground agitating device is, 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 outward extension from the excavation shaft above the excavation blade Mainly with stirring blades. In order to improve the ground using this ground stirring device, the ground is penetrated into the ground while the excavation shaft is rotated around the axis, and the ground is excavated in a columnar shape by the excavation blades 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 to the ground (sediment) excavated by the excavating blade. This solidifying agent is stirred and mixed with earth and sand by a stirring blade provided above the excavating blade, and a columnar improved ground (improved body) is formed as the solidifying agent is hardened.

  Currently, as the ground agitating device, there is a multi-axis type ground agitating device provided with a plurality of excavating shafts. In this multi-axis type ground agitator, based on the difference in the inter-axis pitch, the contact circle type in which the mutually adjacent improvement bodies are in contact with each other and the improvement bodies adjacent to each other partially overlap each other. It is classified into a wrap type and a separation type in which improvement bodies adjacent to each other are separated from each other. Of course, the current implementation is generally performed in a contact or wrap type, and is rarely performed in a separated type. This is due to the following reason.

  First, in the multi-axis type ground stirring device, when the separation type is used, the separation portion is not agitated and may not be improved. Moreover, in a multi-axis type ground agitating device, a plurality of excavation shafts are connected by a connecting member (so-called connection band) so that shaft shake does not occur during drilling. However, since this connecting member is inserted 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, the connecting member is provided with a drilling blade or a stirring blade unique to the connecting member, and the lack of drilling and stirring in the separated portion is compensated. It is possible. However, if a unique excavating blade or stirring blade is provided, the ground stirring device becomes extremely complicated.

JP-A-7-3774

  SUMMARY OF THE INVENTION The main problem to be solved by the present invention is to provide a simple ground agitating device that does not have a possibility that the separated portion is not agitated and not improved even when the multiaxial ground agitating device is a separated type. It is in.

Means for solving the above problems are as follows:
A plurality of excavation shafts that rotate around an axis, a connection member that connects the plurality of excavation shafts, and a lower auxiliary member that protrudes downward from the connection 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 perpendicular to the extending direction of the connecting member, the tip edge,
The ground diffusion portion has a width with respect to the extending direction of the connecting member extending from the ground cut portion toward the connecting member.
This is a ground agitating device.

  According to the present invention, even when the multi-axis type ground agitating device is a separation type, a simple ground agitating device is obtained in which the separated portion is not agitated and is not improved.

It is a front view of a ground stirring apparatus. It is a side view of a ground stirring apparatus. (1) is an XX line arrow view of FIG. 2, (2) is a YY line arrow view of FIG. It is a side view of an auxiliary member. It is explanatory drawing which shows the motion of the ground (earth and sand).

  Next, modes for carrying out the invention will be described. Note that this embodiment is an example of the present invention. The present invention is not limited to the scope of this embodiment.

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

(Drilling blade)
At the tip of the excavation shaft 10, an excavation blade 31 composed of one excavation blade 31 a and the other excavation blade 31 b is provided. On the other hand, the excavation blade 31a and the other excavation blade 31b have a semi-spiral shape with the excavation shaft 10 as the center. On the other hand, the excavation blade 31a and the other excavation blade 31b are arranged so as to be point-symmetric about the excavation axis 10. On the other hand, the ground G is excavated by the excavation blade 31a and the other excavation blade 31b.

  On the other hand, a plurality of excavation bits 31x (three in the illustrated example) are provided at the lower ends of the excavation blade 31a and the other excavation blade 31b. The excavation bid 31x allows the ground G to be excavated smoothly and quickly.

(Excavation blade)
On the other hand, the excavation shaft 10 in the vicinity of the upper ends of the 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. On the other hand, each of the excavation blades 35a and the other excavation blades 35b has a plate shape extending outward from the outer peripheral surface 10a of the excavation shaft 10. On the other hand, the excavation blade 35a and the other excavation blade 35b are arranged so as to be point-symmetric about the excavation shaft 10 respectively. On the other hand, when the ground G is excavated by the excavation blade 35a and the other excavation blade 35b, the excavation blade 35a is agitated.

  On the other hand, on the other excavation blade 35a and the other excavation blade 35b, when the rotation direction (rotation A) at the time of penetration is used as a reference, the portion on the front side (lower edge portion) is more than the portion on the rear side (upper edge portion). An inclination of a predetermined angle located below is given, for example, an inclination of 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.

  A plurality of excavation bits 35x projecting along the inclinations of the one excavation blade 35a and the other excavation blade 35b are respectively provided on the lower lower edge of the one excavation blade 35a and the other excavation blade 35b (3 in the illustrated example). Book) is provided. The excavation bid 35x allows the ground G to be excavated smoothly and quickly.

  On the other hand, the excavation blade 35a and the other excavation blade 35b are arranged so that the lower edge portions thereof are parallel to the lower end edge portions 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)
On the other hand, the excavation shaft 10 above the excavation blade 35a and the other excavation blade 35b is provided with a straight agitating blade 41 composed of one linear agitation blade 41a and the other straight agitation blade 41b. On the other hand, the straight stirring blade 41a and the other straight stirring blade 41b each have a plate shape extending outward from the outer peripheral surface 10a of the excavation shaft 10. On the other hand, the straight stirring blade 41a and the other straight stirring blade 41b are arranged so as to be point-symmetric about the excavation shaft 10. On the other hand, the ground (earth and sand) G excavated by the excavating blade 31 and the excavating blade 35 is agitated by the linear agitating blade 41a and the other linear agitating blade 41b.

  On the other hand, the straight agitating blade 41a and the other straight agitating blade 41b are also inclined similarly to the one excavating blade 35a and the other excavating blade 35b. Specifically, when the rotation direction (rotation A) at the time of penetration is used as a reference, the part on the front side (lower edge part) has a predetermined angle located below the part on the rear side (upper edge part). 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.

  For example, the straight agitating blade 41a and the other straight agitating blade 41b have a lower edge of 30 to 60 ° in plan view so that the lower edge of the straight agitating blade 41a is not parallel to the lower edge of the one excavating blade 35a and the other excavating blade 35b. They are arranged to intersect at an angle. The one linear stirring blade 41a and the other linear stirring blade 41b extend slightly inward from the one excavating blade 35a and the other excavating blade 35b.

  On the other hand, the lower surface of the straight stirring blade 41a and the other linear stirring blade 41b protrudes downward on the side of the excavation shaft 10 and has a substantially rectangular cross section along the extending direction of the one linear stirring blade 41a and the other linear stirring blade 41b. A convex corner member 41x is provided. This convex corner member 41x reduces the resistance when the ground agitating device 1 penetrates the ground G.

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

  On the other hand, 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. On the other hand, both surfaces of the lower shear plate 51a and the other lower shear plate 51b face the rotation direction. On the other hand, 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 cylindrical body 51c is provided on the outer peripheral surface 10a of the excavating shaft 10 so as to be rotatable about the axis, and one lower shear plate 51a and the other lower shear are provided on the outer peripheral surface of the cylindrical body 51c. The plate 51b is fixed. The cylindrical 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 manner, the excavated ground G is gently sheared and rotates together in all the parts in the axial direction. Is moderately prevented.

(Lower stirring blade / Upper stirring blade)
On the excavation shaft 10 above the lower shear plate 51, a lower stirring blade 21 composed of one lower stirring blade 21a and the other lower stirring blade 21b is provided. The excavation shaft 10 above the lower stirring blade 21 is provided with an upper stirring blade 25 composed of 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 is bent in one direction of rotation and the upper stirring blade 25 is bent in the other direction of rotation. However, both the stirring blades 21 and 25 have basically 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.

  On the other hand, the 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. On the other hand, the lower stirring blade 21a and the other lower stirring blade 21b are arranged so as to be point-symmetric about the excavation shaft 10. On the other hand, the lower agitating blade 21a and the other lower agitating blade 21b are plate-like, and are inclined similarly to the one excavating blade 35a and the other excavating blade 35b. More specifically, when the rotation direction (rotation A) at the time of penetration is used as a reference, a slope of a predetermined angle where the front side part (lower edge part) is located below the rear side part (upper edge part) However, for example, an inclination of 40 to 50 ° is provided. By this inclination, for example, the propulsive force of the ground stirring device 1 at the time of penetration can be obtained. On the other hand, the ground G or the like excavated by the excavating blade 31 or the excavating blade 35 is agitated by the lower agitating blade 21a and the other lower agitating blade 21b.

  On the other hand, the lower agitating blade 21a and the other lower agitating blade 21b are shaped to bend in one direction (rearward) in the rotational direction toward the outside. Therefore, the payout function of the excavated ground G or the like is exhibited, and the stirring unevenness in the radial direction is surely prevented. Here, “bend” is a concept including bending, bending at one place or a plurality of two or more places, and a combination of bending and bending. However, the one lower stirring blade 21a and the other lower stirring blade 21b are preferably bent. In the example shown in FIG. 3, the stirring blades 21a, 21b, 25a, and 25b are bent at two locations, respectively (the bent portion is indicated by reference numeral 21p).

  The one 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 (1) of FIG. 3, it is different in that it bends in a different direction (the other) from the one lower stirring blade 21a and the other lower stirring blade 21b. When the lower stirring blade 21 and the upper stirring blade 25 positioned above and below bend in different directions, the “other” exhibits the scraping function when “one” exhibits the payout function. Therefore, the stirring performance in the radial direction of the excavated ground G and the like is improved.

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

(Upper shear plate)
On the excavation shaft 10 between the lower stirring blade 21 and the upper stirring blade 25, an upper shear plate 55 is provided. 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 55 a, the other upper shear plate 55 b, and the upper connection member 53. On the other hand, the upper shear plate 55a has a plate shape extending outward from one excavation shaft 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 the pair of excavation shafts 10. On the other hand, the upper side shear plate 55a, the other upper side shear plate 55b, and the lower side connection member 52 are arranged in a straight line. The upper connecting member 53 and the lower connecting member 52 constitute a connecting member of the ground agitating device 1. The excavated ground G is gently sheared by the upper shear plate 55, and it is gently prevented from co-rotating integrally at all parts in the axial direction.

(Second straight stirring blade)
The excavation shaft 10 above the upper shear plate 55 is provided with a second straight stirring blade 45 including a second one linear stirring blade 45a and a second other straight stirring blade 45b. The second one linear agitating blade 45a and the second other linear agitating blade 45b have the same structure as the (first) one linear agitating blade 41a and the other linear agitating blade 41b. The ground G or the like excavated by the excavating blade 31 or the excavating blade 35 is agitated by the second one linear agitating blade 45a and the second other linear agitating blade 45b. In addition, the code | symbol 45x is a convex angle | corner material.

(Axle shake prevention pin)
The tip surface of the excavation shaft 10 is provided with a shaft blur prevention pin 70 protruding toward the front (downward). The ground stirring device 1 of this embodiment is configured to stir the ground G (earth and sand) excavated by the lower stirring blade 21 and the upper stirring blade 25 in the radial direction. Therefore, especially when the excavation shaft 10 penetrates, there is a possibility that shaft blurring occurs with stirring. However, in the ground agitation device 1 of this embodiment, the shaft shake is prevented because the shaft shake prevention pin 70 is pierced into the ground G that has not been excavated, and excavation and stirring are performed.

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

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

  The ground cut portion 81 has a leading edge (lower end edge) extending in a direction orthogonal to the extending direction of the lower connecting member 52 (in FIG. 4, simply indicated as “orthogonal direction”). . When penetrating the ground stirring device 1 into the ground G, particularly when penetrating the separated ground stirring device 1, 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 cutting part 81 can be comprised by the commercially available nail | claw etc. which are used with a backhoe, for example. In this embodiment, as shown in FIG. 4, the ground cut portion 81 is configured by providing two backhoe claws so that the tip edges are in series.

  The ground diffusion part 82 is interposed between the ground cut part 81 and the lower connecting member 52. The ground diffusion part 82 is configured such that the width of the lower connection member 52 in the extending direction increases from the ground cut part 81 toward the lower connection member 52. According to the lower auxiliary member (81, 82) of the present embodiment thus configured, as shown in (1) of FIG. 5, the ground G (earth and sand) cut by the ground cutting portion 81 is the ground diffusion portion. In the process of rising along 82, it diffuses toward the excavation shaft 10. Therefore, even in the separation-type ground agitating device 1, there is no possibility that the separation portion is not agitated and is not improved.

However, according to this embodiment, 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 positioned below the lower connecting member 52, and in this embodiment, a linear stirring blade 41 is provided. The lower auxiliary member (81, 82) protrudes to the side of the first stirring blade (linear stirring blade 41). According to this form, the ground G (earth and sand) stirred by the linear stirring blade 41 is diffused toward the lower auxiliary member (81, 82), and the diffused earth and sand is cut by the ground cutting portion 81. It rises along the ground diffusion part 82 together with the earth and sand, and further diffuses toward the excavation shaft 10. Therefore, the ground (earth and sand) is more strongly diffused.

  Next, the center 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, 53 is increased. As a result, the shaft displacement 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) in 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 in this embodiment, the lower stirring blade 21 is provided. The central auxiliary member 83 is configured such that the width in the extending direction of the connecting members 52 and 53 increases from the central portion in the vertical direction toward both ends in the vertical direction (connecting members 52 and 52). According to this form, as shown in (2) of FIG. 5, the ground G (sediment) discharged by the lower stirring blade 21 faces the connecting members 52 and 53 along both side surfaces of the central auxiliary member 83, Furthermore, it is diffused toward the excavation shaft 10 in this process. Therefore, the ground G (earth and sand) is effectively stirred in the separated portion. In this regard, as is apparent from the above mechanism, in the present embodiment, it is preferable to employ a curved or bent stirring blade having a ground G discharging function as the lower stirring blade 21.

  In configuring the central auxiliary member 83 as described above, it is preferable that the cylindrical members 83a and 83b are assembled in an X shape when viewed from the front 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 shaft displacement of the excavation shaft 10 is more effectively prevented.

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

  INDUSTRIAL APPLICABILITY The present invention can be used as a ground agitation device used in a ground improvement method or the like.

  DESCRIPTION OF SYMBOLS 1 ... Ground stirring apparatus, 10 ... Excavation shaft, 10a ... Outer peripheral 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 ... other upper stirring blades, 31 ... excavation blade, 31a ... one excavation blade, 31b ... other excavation blade, 31x ... excavation bit, 35 ... excavation blade, 35a ... one excavation blade, 35b ... other excavation blade, 35x ... Drilling bit, 41 ... straight stirrer blade, 41a ... one straight stirrer blade, 41b ... other straight stirrer blade, 41x ... convex square member, 45 ... second straight stirrer blade, 45a ... second one straight line Stirring blade, 45b ... second straight straight 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 ... whereas the upper shear plate, 55b ... other upper shear plate, 70 ... shaft wobble prevention pin, G ... ground.

Claims (6)

A plurality of excavation shafts that rotate around an axis, a connection member that connects the plurality of excavation shafts, and a lower auxiliary member that protrudes downward from the connection 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 perpendicular to the extending direction of the connecting member, the tip edge,
The ground diffusion portion has a width with respect to the extending direction of the connecting member extending from the ground cut portion toward the connecting member.
A ground agitator characterized by that. The excavation shaft is provided with a first stirring blade located below the connecting member,
The lower auxiliary member protrudes to the side of the first stirring blade,
The ground agitating device according to claim 1. 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 protrudes downward from the lower connecting member,
A central auxiliary member for connecting the upper connecting member and the lower connecting member is provided,
The center auxiliary member has a width related to the extending direction of the connecting member that expands from the vertical center to the vertical ends.
The ground stirrer according to claim 1 or 2. The central auxiliary member has a truss structure in which cylindrical members are assembled in an X shape.
The ground agitating device according to claim 3. The second agitating blade is plate-shaped, and a portion on the front side is inclined to be lower than a portion on the rear side, and bends backward in the rotation direction toward the outside. It is a bent shape,
The ground stirrer according to claim 3 or 4. The upper connecting member is provided with an upper auxiliary member protruding upward,
The upper auxiliary member has a distal end edge extending in the extending direction of the connecting member, and a width in a direction perpendicular to the extending direction of the connecting member increases from the distal end edge toward the upper connecting member. ,
The ground stirrer according to any one of claims 3 to 5.

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