JP6083844B1 - Excavation and stirring tool for ground improvement equipment - Google Patents

Abstract

[PROBLEMS] To achieve excellent kneading by kneading and agitation like multi-axis driving excavation / stirring tools, workability with less penetration and pull-out resistance, and light weight and economical characteristics that are the characteristics of a single-shaft type. Provide drilling and stirring tools. In an excavation / stirring tool for ground improvement by kneading excavated soil and improvement material while excavating / stirring the ground, an excavation / stirring shaft extending in the vertical direction, A drilling blade provided at the lower end and excavating from the outer periphery of the excavation / stirring shaft to form an arc shape, around the outer surface of the excavation / stirring shaft or around the outer periphery of the excavation / stirring shaft A plurality of stirring blades supporting at least one end with respect to the outer peripheral surface of the loosely-fitted boss portion, and as the plurality of stirring blades, a driving stirring blade that rotates integrally with the excavation / stirring shaft; And a stirrer blade that rotates in a floating state with respect to the stirrer shaft, and among the stirrer blades, the outermost outer stirrer blade is used as a stirrer blade. [Selection] Figure 2

Description

  The present invention relates to an excavation / stirring tool for a ground improvement device.

  Conventionally, the excavation / stirring tool of the ground improvement device is classified by a drilling / stirring shaft for rotating a stirring blade, and a multi-shaft type drilling / stirring tool (hereinafter also simply referred to as a multi-shaft type) and a single-shaft type. Drilling and stirring tools (hereinafter also simply referred to as single shaft type).

  The multi-shaft type is an inner / outer biaxial relative rotation structure in which the inner and outer agitating blades, which are formed in an arc shape by bulging the middle part outward at the lower end of the excavation / agitation shaft, are individually rotated. It is attached to the excavation / stirring shaft and has a so-called relative agitation structure in which each agitating blade is rotated in the opposite direction to prevent the excavated soil and the improved material from co-rotating. (For example, refer to Patent Document 1 and Patent Document 2.)

On the other hand, the single-shaft type is one in which inner and outer stirring blades are attached to a single excavation / stirring shaft, and the excavated soil excavated by simultaneously rotating the inner and outer stirring blades in one direction is kneaded with the improvement material, In order to prevent the excavated soil and the improved material from rotating together with the rotation of the stirring blade, either one of the inner and outer stirring blades is rotated on a single axis, and the other blade is rotated integrally with the single axis. It is configured to be in a fixed state so as not to occur.

That is, the single-shaft type uses a resistance against the rotation direction due to engagement of a non-rotating blade (hereinafter also referred to simply as a fixed blade) to an unexcavated ground that is the inner peripheral wall of the drilling hole, thereby allowing the single shaft type to enter the drilling hole. It is fixed and fixed, and the rotating blades (hereinafter also referred to simply as “rotary drive blades”) are driven to rotate integrally with the excavating / stirring shaft, thereby preventing co-rotation and stirring the excavated soil and the improved material. Mixing is possible. Here, the unexcavated ground refers to the ground in a natural state where the rotary agitation of the excavating blade and the stirring blade does not act.

For example, such a single-shaft drilling / stirring tool is connected to a fixed blade engaged with unexcavated ground so that the outer stirring blade is a rotary drive blade and the inner stirring blade is a fixed blade (for example, a patent) (Refer to Document 3 and Patent Document 4), and conversely, the inner agitating blade is a rotationally driven blade and the outer agitating blade is a stationary blade (see, for example, Patent Document 5, Patent Document 6, and Patent Document 7). Has been.

  That is, in the single-shaft type, the excavated soil and the improved material near the rotary drive blade rotate together in the excavation hole, and the excavated soil and the improved material near the fixed blade stay in a stationary state. The agitating state is generated, and the relative blade cutting agitation function is achieved despite the uniaxial excavation and agitation shaft.

JP 7-42146 A JP 2005-320830 A JP 2009-102872 A JP 2014-88758 A JP 2006-37432 A JP 2008-57322 A JP 2011-69093 A

Such fixed wing drilling and stirring tool of the single-axis type are engageable in the non-excavation soil of any drilling drilling wall.

For example, configure fixed wing through another resistor wings and the boss portion and the fixed blades, and the like constituting the solid Teitsubasa provided resistive plate in the radial or outward stirring blade outer stirring wing, above The co-rotation phenomenon is prevented.

  In some cases, a plurality of inner and outer horizontal agitating blades that face each other in a staggered manner are provided so as to increase the number of blades cut by the blades to improve the agitation efficiency.

  By the way, the excavation / stirring tool is used to move the excavation / stirring shaft up and down in the vertical direction of the excavation hole in order to stir the excavated soil and the improved material evenly in the excavation hole. Directional stirring is performed.

However, since the member for providing a fixed-wing or fixed wing immobility engages the non-excavation soil that is a peripheral wall of the drilling drilling, lifting resistance increases during the lifting operation, rather for ground improvement There has been a drawback that the construction efficiency of the excavation and kneading work is significantly reduced.

  In addition, the excavator / stirring tool provides a shearing force to the excavated soil, improved material, improved soil, etc. (hereinafter also simply referred to as excavated / improved soil) existing in the vicinity of the agitated blade, as described above. Excavation / improvement soil that rotates together with the excavation / improvement soil that does not rotate with the agitating blades is used for complex kneading / agitation of the excavation / improvement soil.

  The distribution tendency of the shearing force of the agitator blades to the excavated / improved soil in the excavation hole occurs in the excavated / improved soil depending on the nature of the excavated / improved soil, the shape of each agitator blade, the position of the agitator / shaft shaft, etc. It can be defined as a “shear line” that determines the agitation range.

  In other words, the “shear line” refers to the excavation / improvement soil existing between the agitation blades of the excavation / stirring tool in the excavation hole. Rotating and stirring area of excavated and improved soil that is directly affected by the blade, and it is stationary without being directly affected by the rotary drive blade, or indirectly affected by the rotation of the rotary drive blade It is a line that divides it into a stationary agitation area of the excavation / agitation soil in a state where the rotation is delayed, and is also a line that determines the shear fracture surface of the excavation / agitation soil.

Then, when looking at the traditional drilling and stirring device 100 comprising a horizontal stirring blade 210, 310 and above mentioned in terms of such "shear line", as shown in FIG. 20, the excavation and stirred earth as viewed from the side The shear line of mixing stirring becomes a virtual zigzag line S2 (indicated by a solid line in FIG. 20) that bypasses the tip portion of the alternate horizontal projection, and the shear line is lengthened correspondingly to increase the shear resistance.

In other words, in the excavation / stirring tool 100 having the general horizontal stirring blades 210 and 310, the end of the horizontal stirring blade 210 serving as the driving stirring blade 200 protrudes to the vicinity of the end of the stirring diameter d in the radial direction. The “shear line” is generated along the stirring diameter end (indicated by a broken line in FIG. 20).

  In addition, due to the fluidity and adhesiveness of the excavation / stirring soil in the rotary stirring region, the rotational influence range of the driving stirrer blade 200 is expanded to the excavation / stirring soil existing near the outer stirrer blade 310. The influence was transmitted, and it was the cause of co-rotation of excavation and agitation soil without forming a static agitation region in the excavation hole.

Therefore, in order to prevent the co-rotation phenomenon, the outer agitating blade 310 is used as the stationary blade 300 in a stationary state, and the stationary blade 300 or a member for providing the stationary blade 300, for example, the stationary plate 320 is surely entered into the unexcavated ground. such as by, engaged with the non-excavation soil of drilling wall digging stator blade 300 as described above ensures more resistance, it was necessary to expand the still stirring region of excavation and stirring soil .

  On the other hand, inner and outer agitating blades are attached to the inner and outer two-axis relative rotating structures of the multi-shaft type which are driven to rotate by attaching inner and outer agitating blades that bulge out in the middle to form arcs. In the so-called relative stirring blade structure that rotates the blades in opposite directions, it seems reasonable in terms of mixing and stirring efficiency in the borehole.

  However, in order to achieve a multi-shaft inner / outer biaxial relative rotation structure, the upper end of the inner / outer double shaft must be interlocked and connected to the drive motor via a counter-rotating gear mechanism. The entire apparatus inevitably increases in size, and the manufacturing cost of the ground improvement device becomes high, and as a result, there is a drawback that the construction cost of the ground improvement work increases.

  The present invention has been made in view of such circumstances, and is excellent in kneadability by kneading and agitation such as a multi-shaft type, workability with less penetration and pull-out resistance, and light weight that is a feature of a single-shaft type. An object of the present invention is to provide a single-axis drive excavation and stirring tool that is economical.

In order to solve the above conventional problems, in the excavation / stirring tool according to the present invention, (1) a drilling / stirring tool for improving the ground by kneading the excavated soil and the improving material while excavating and stirring the ground , A drilling / stirring shaft extending in the vertical direction, a drilling blade for excavating the ground, and an arcuate bulging outward from the outer periphery of the excavation / stirring shaft. A plurality of stirring blades supporting at least one end with respect to the outer peripheral surface of the digging / stirring shaft or the outer peripheral surface of the boss part loosely fitted around the outer periphery of the digging / stirring shaft, A drive agitating blade that rotates integrally with the excavation / stirring shaft, and a floating stirring blade that rotates in a floating state with respect to the excavation / stirring shaft, and the outermost outer side of the stirring blades the stirring blade was a loose stirring blade, the outer stirring blade, said drilling A blade body extending in a direction along the axial direction of the stirring shaft, and a blade support extending from the blade body to the excavation / stirring shaft, the blade body and the blade support The outer stirrer blade has a torsional shape with respect to the axial direction of the excavation / stirring shaft or a shape inclined with respect to the coaxial direction so as to have an inclined surface that is inclined with respect to the vertical direction.・ While the outer agitating blade is rotated by the soil resistance applied to the inclined surface as it moves up and down at the time of extraction, the outer surface is affected by the soil resistance received on the inclined surface when the vertical movement of the penetration and extraction is not involved. The present invention is characterized in that the stirring blade is placed in a stationary state or a state in which the rotational speed is delayed from that of the drive stirring blade to prevent the outer stirring blade from rotating together .

The excavation / stirring tool according to the present invention is also characterized by the following points.
(2) The drive stirring blades and the floating stirring blades are alternately arranged at predetermined intervals from the outer stirring blade that is the floating stirring blade to the inside.
(3) The outer stirrer blade has the width of the blade shape surface in the side view as the member width, the width of the blade shape surface in the axial direction as the member thickness, and the member thickness is equal to or less than the member width.
(4) The outer agitating blade has a twisted shape with respect to the axial direction of the excavation / stirring shaft or a shape inclined with respect to the coaxial direction. Rotating by soil resistance with vertical movement.

According to the first aspect of the present invention, in the excavation / stirring tool for improving the ground by kneading the excavated soil and the improving material while excavating / stirring the ground, the excavation / stirring shaft extending in the vertical direction is provided. A drilling blade provided at the lower end of the excavation / stirring shaft and excavating ground from the outer periphery of the excavation / stirring shaft to form an arc, and the outer surface of the excavation / stirring shaft or the same excavation / stirring A plurality of stirring blades that support at least one end with respect to the outer peripheral surface of the boss part loosely fitted around the outer periphery of the shaft, and the driving stirring blades that rotate integrally with the excavation and stirring shaft as the plurality of stirring blades And an agitating agitating blade that rotates in a floating state with respect to the excavating and agitating shaft, and among the agitating blades, the outermost agitating blade is a floating agitating blade, and the outer agitating blade is A blade body extending in a direction along the axial direction of the excavation and stirring shaft; A blade support part extending from the blade body part to the excavation / stirring shaft, and the outer side so that the blade body part and the blade support part have inclined surfaces inclined with respect to the vertical direction. Soil impingement on the inclined surface due to vertical movement during intrusion and extraction during ground improvement, with the agitator blade being twisted with respect to the axial direction of the excavation and agitation shaft or inclined with respect to the coaxial direction The outer agitating blade is put into a rotating operation state by the above, while if the vertical movement of the penetration and withdrawal is not performed, the rotation speed is delayed from the stationary stirring blade or the driving agitating blade due to the soil resistance applied to the inclined surface. Because it is configured to prevent the outer stirring blades from rotating together, it has excellent kneading ability by kneading and stirring, such as a multi-shaft type, while being single-shaft type, and workability with low penetration and pull-out resistance , And light weight It is possible to provide a drilling and stirring device that combines sex. Moreover, the outer stirrer blades and other floating agitator blades linked to this can be rotated in a certain direction, further improving the relative rotation agitation with the drive stirrer blades and moving in the axial direction of the outer periphery improved soil. Kneading and agitation of the excavated soil and the improving material can be steadily achieved while promoting the passage of the material, and good kneadability can be ensured.

  Here, the improved soil in which the excavated soil and the improved material are kneaded by the excavation / stirring tool configured as described above is a cross-sectional defect with respect to the improved cross-sectional area in the axial direction of the excavation / stirring shaft and the outer stirring blade, The passage around the center of the stirrer is controlled by the passage resistance due to the rotation of the inner stirrer, and the frictional force around the stirrer and excavation / stirring shaft, leading to the vicinity of the outer stirrer with low passage resistance. It becomes.

  As a result, at the time of raising and lowering, an axial passage region of the improved soil is formed toward the outer peripheral portion of the outer stirring blade (near the inner peripheral wall of the excavation hole). In other words, the area through which the improved soil passes in the axial direction is less affected by the rotational action of the inner stirring blade, and forms the stationary stirring area as described above.

  In particular, in the present invention, since the floating stirring blade as the outer stirring blade and the driving stirring blade as the inner stirring blade formed in the arc shape by bulging outward from the outer periphery of the excavation / stirring shaft, as shown in FIG. The shear line of the excavating / stirring soil between the floating stirrer blade and the driving stirrer blade is substantially straight along the shape of the driving stirrer blade in the axial direction or substantially parallel to the driving stirrer blade. The rotation stirring region and the stationary stirring region can be surely divided to prevent the occurrence of a common phenomenon of excavation and stirring soil.

In addition, since the outermost outer agitating blade is a floating agitating blade , it is buried in the improved soil (hereinafter also referred to as the outer peripheral improved soil) existing in the stationary agitating region led to the vicinity of the outer agitating blade with low passage resistance. The outer peripheral improved soil gives resistance to the rotation direction of the outer agitating blade so that the agitating blade is in a stationary state or a state in which the rotational speed is delayed from the driving agitating blade disposed on the inner side. And efficient relative rotational stirring by the floating stirring blade.

Further, it is possible to improve the vertical stirring efficiency by suppressing vertical drive energy required lifting of the penetration-extraction of excavation and stirring device, without interfering with the lifting outer stirring blade engages the borehole wall The efficiency of excavation and kneading work can be improved.

  Moreover, the flow of the earth and sand and the improved soil during the ascent and descent can be in a direction substantially parallel to the axial direction, i.e., along the driving stirring blade and the floating stirring blade, particularly in the member surface by the side view of the floating stirring blade, By making it almost parallel to the flow of the improved soil, adhesion of the improved soil can be prevented, and the flow of the improved soil around the outer periphery can be easily made perpendicular to the direction of rotation of the outer stirring blade. To promote the soil resistance of the improved soil around the outer periphery, and to make the floating stirring blade stationary or in a rotationally delayed state with respect to the driving stirring blade, further improving the efficiency of relative rotational stirring by the single-shaft floating stirring blade and the driving stirring blade Can do.

  Further, according to the invention of claim 2, since the drive stirring blade and the floating stirring blade are alternately arranged at predetermined intervals from the outer stirring blade which is the floating stirring blade to the inner side, The “shear line” for the excavation and agitation soil between the agitating blades should be approximately straight along the shape of the inner agitating blade, which is the driving agitating blade, in the axial direction or substantially parallel to the inner agitating blade. Easily prevent the occurrence of co-rotation phenomenon, and even if multiple agitating blades are arranged, each agitating blade does not co-rotate and the shearing force is reliably applied to the excavated and agitated soil to improve the agitation efficiency. be able to.

  In addition, since it is possible to arrange each stirring blade to prevent the co-rotation phenomenon, a stirring blade that rotates integrally with the outer stirring blade is provided on the inner side of the driving stirring blade among the plurality of stirring blades. Thus, the efficiency of relative rotation stirring by the floating stirring blade and the driving stirring blade can be dramatically improved.

  Further, according to the invention of claim 3, the outer agitating blade has the width of the blade shape surface in the side view as the member width, the width of the blade shape surface in the axial direction as the member thickness, and the member thickness is the member width. Because it is determined as follows, the blade area relative to the improved area in the axial direction of the outer agitating blade can be reduced, and the passage resistance of the improved soil and excavated soil during agitation operation of penetration and extraction is reduced. The construction speed can be improved by increasing the passage promotion effect.

  In addition, the outer stirring blade can be formed into a thin plate shape, and the improved soil flowing along the axial direction from the end of the blade side surface in the axial direction when the improved soil passes through the outer stirring blade, Due to its adhesiveness, it can enter the upper and lower side surfaces of the wing, reduce the area where it stays without being affected by the improved soil flow in the axial direction, and reduce the adhesion of the improved soil to the wing shadow. Good kneadability between the soil and the improved material can be ensured.

  In this way, despite the single-shaft inner / outer stirring blade structure, the rotation of the outer stirring blade is suppressed during the mixing and stirring operation so that the stationary state can be achieved, and relative stirring can be achieved while preventing co-rotation. The cost of the apparatus itself is low, and the construction cost can be reduced.

It is a side view which shows the ground improvement apparatus provided with the excavation and stirring tool concerning this invention. It is a perspective view which shows the basic structure of the excavation and stirring tool concerning this invention. It is explanatory drawing which shows the excavation / stirring tool concerning this invention. It is explanatory drawing which shows the excavation / stirring tool concerning this invention. It is explanatory drawing which shows the excavation / stirring tool concerning this invention. It is explanatory drawing which shows the modification 1 of the excavation / stirring tool concerning this invention. It is explanatory drawing which shows the modification 2 of the excavation / stirring tool concerning this invention. It is explanatory drawing which shows the modification 3 of the excavation / stirring tool concerning this invention. It is explanatory drawing which shows the modification 4 of the excavation / stirring tool concerning this invention. It is explanatory drawing which shows the modification 5 of the excavation and stirring tool concerning this invention. It is explanatory drawing which shows the modification 6 of the excavation / stirring tool concerning this invention. It is explanatory drawing which shows the modification 7 of the excavation / stirring tool concerning this invention. It is explanatory drawing which shows the modification 8 of the excavation / stirring tool concerning this invention. It is explanatory drawing which shows the modification 9 of the excavation / stirring tool concerning this invention. It is explanatory drawing which shows the modification 10 of the excavation / stirring tool concerning this invention. It is explanatory drawing which shows the modification 10 of the excavation / stirring tool concerning this invention. It is explanatory drawing which shows the modification 11 of the digging and stirring tool concerning this invention. It is explanatory drawing which shows the other modification of the excavation / stirring tool concerning this invention. It is explanatory drawing which shows the shear line by the excavation and stirring tool concerning this invention. It is explanatory drawing which shows the structure and shear line of the conventional single shaft type excavation and stirring tool.

The gist of the present invention is an excavation / stirring tool for performing ground improvement by kneading excavated soil and improvement material while excavating / stirring the ground. A drilling blade provided at the lower end of the shaft and excavating the ground from the outer periphery of the excavation / stirring shaft and formed in an arc shape to form an outer peripheral surface of the excavation / stirring shaft or an outer periphery of the excavation / stirring shaft A plurality of stirring blades supporting at least one end with respect to the outer peripheral surface of the boss part loosely fitted around, and as the plurality of stirring blades, a driving stirring blade that rotates integrally with the excavation / stirring shaft, and It has a loose stirring blade rotating at floating state with respect to the drilling and stirring shaft, and moreover, of the stirring blade, in the most to the outside of the outer stirring wing was floating stirring blade.

  Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a ground improvement device K equipped with a drilling / stirring tool according to the present invention, and FIGS. 3, 4, and 5 show a drilling / stirring tool D of the present invention.

[1. (Ground improvement device)
First, the basic structure of the ground improvement apparatus K provided with the stirring tool D concerning this invention is demonstrated. As shown in FIG. 1, the ground improvement device K is installed on the ground surface of the improved portion of the ground G.

  The ground improvement device K is provided with a leader B extending vertically in a base machine main body A capable of self-propelling, and the leader B is provided with an upper end of a vertical excavation / stirring shaft 1 via a rotation drive unit I. It is a basic configuration to include an improvement material supply unit C that supplies the improvement material.

  The improvement material supply unit C disposed at the rear position of the base machine main body A communicates with the rotation drive unit I through the improvement material supply path E, and the improvement material is disposed inside the excavation / stirring shaft 1. It is configured to be discharged from the lower part of the excavation / stirring shaft 1 into the excavation hole. In addition, as an improvement material, it is a material used in order to improve the ground, and a solidifying material, an admixture, an additive, a neutralizing agent, a chemical | medical agent, a chemical agent, etc. are used.

  The rotation drive unit I is provided with a rotation member at a predetermined position on the upper part thereof, and one end is connected to a drive rotation drum (not shown) built in the rear part of the base machine body A, and the rotation drive unit I is connected via the topmost part of the reader B. A rotational driving force from the base machine main body A is transmitted by a suspension wire F wound around the rotating member and having the other end fixed to the upper part of the reader B.

  That is, the rotary driving force of the driving rotary drum is converted into the vertical lift driving force along the leader B, and the excavation / stirring shaft is moved up and down at the time of penetration and extraction in the ground improvement.

  As shown in FIGS. 1 and 2, the ground improvement device K functions as a main part for performing ground improvement by mixing the excavated soil and the improvement material while excavating and stirring the ground G. Tool D is provided.

[2. (Drilling / stirring tool)
Hereinafter, the structure of the excavation / stirring tool D according to the present invention will be described with reference to the drawings. Fig.3 (a) is a side view which shows the structure which used the stirring blade of the excavation and stirring tool D concerning this invention as the two-stage blade, and FIG.3 (b) shows the axial view. 4 (a) and 4 (b) show a configuration in which the agitation blade of the excavation / stirring tool D is a three-stage blade, and FIG. 5 (a) and FIG. A configuration in which the stirring blades are four-stage blades is shown.

  That is, the excavation / stirring tool D excavates the excavation / stirring shaft 1 extending in the vertical direction and the ground provided at the lower end of the excavation / stirring shaft 1, as shown in FIGS. 3, 4, and 5. The boss 2 and a boss part that bulges outward from the outer periphery of the excavation / stirring shaft 1 and has an arc shape, and is loosely fitted around the outer peripheral surface of the excavation / stirring shaft 1 or the outer periphery of the excavation / stirring shaft 1 And a plurality of stirring blades supporting at least one end with respect to the outer peripheral surface.

  Here, in the present embodiment, the “arc shape” which is the shape of the stirring blade is not only a substantially arc shape having no corner portion, but also a substantially triangular arc shape having one corner portion, and a substantially square arc shape having two corner portions. Furthermore, a substantially polygonal shape having three or more corners is also included. Moreover, what is chamfered by R shape as a corner | angular part is also contained. Each of the “arc-shaped” shapes is supported on the outer peripheral surface of the excavating / stirring shaft 1 or the outer peripheral surface of the boss part loosely fitted around the outer periphery of the excavating / stirring shaft 1 in a side view. It also includes a shape that bulges axially above and / or below the region.

  The excavation / stirring tool D includes, as a plurality of stirring blades, a drive stirring blade 10 that rotates integrally with the excavation / stirring shaft 1 and a floating stirring blade 20 that rotates in a floating state with respect to the drilling / stirring shaft. Specifically, it is provided for the excavation / stirring shaft 1 as follows.

  The excavation / stirring tool D1 shown in FIG. 3 is provided with a substantially horizontal excavation blade 2 for excavating the ground G at the lower end of the excavation / stirring shaft 1, and a lower boss around the outer periphery of the excavation / stirring shaft 1 thereabove. The two parts 22 and the upper boss part 23 are loosely fitted with a predetermined interval in the axial direction.

  The outer agitating blade 21 is formed in an arc shape in which a middle portion thereof bulges outward from the outer periphery of the excavation / stirring shaft 1. The outer stirrer blade 21 is provided integrally with the outer peripheral surface of the upper boss portion 23 in the direction along the axial direction of the excavation / stirring shaft 1, and the lower end with respect to the outer peripheral surface of the lower boss portion 22. Two are installed symmetrically via the excavation / stirring shaft 1 in a state of being provided integrally and straddling each boss. The two outer stirring blades 21 are provided at equiangular intervals (180 ° intervals) around the excavation / stirring shaft 1. In this way, the outer stirring blade 21 is the idle stirring blade 20 in a floating state with respect to the excavation / stirring shaft 1.

  The outer stirring blade 21 has a strip-like blade main body portion 24 and a blade support portion 25 that form an arcuate outer shape of the outer stirring blade 21 in a side view. More specifically, the outer stirring blade 21 functions as a stirring center for excavation / stirring soil between the blade main body portion 14 and the blade main body portion 14 of the inner stirring blade 11 to be described later. The blade main body 24 is formed in a strip shape extending in the axial direction, and the blade support 25 is extended from the excavation / stirring shaft 1 at both ends of the blade main body 24. That is, the outer stirring blade 21 is disposed so that the blade body 24 is substantially parallel to the excavation / stirring shaft 1 through the blade support 25.

  The outer stirring blade 21 in the present embodiment is formed so as to form a substantially square arc shape (substantially trapezoidal arc shape) together with a portion between the lower boss portion 22 and the upper boss portion 23 of the excavation / stirring shaft 1 in a side view. The side corresponding to the upper base of the substantially trapezoidal arc is the blade main body 24, and the blade support 25 is extended so as to gradually expand from both ends of the blade main body 24 toward the excavation / stirring shaft 1 side. The part 22 and the upper boss part 23 are connected to each other.

  The inner stirring blade 11 is formed to be smaller than the outer stirring blade 21 in a shape substantially similar to the shape of the outer stirring blade 21, and the strip that forms the arc-shaped outer shape of the outer stirring blade 21 in a side view as in the outer stirring blade. And a blade support portion 15 (two in the present embodiment).

  The inner stirring blade 11 connects the upper end and the lower end of the inner stirring blade 11 to the outer peripheral surface of the excavation / stirring shaft 1 exposed between the upper boss portion 23 and the lower boss portion 22, thereby excavating / stirring shaft. 1 and one. In this manner, two symmetrically mounted via the excavation / stirring shaft 1 are provided as drive agitating blades 10 that rotate integrally with the excavation / stirring shaft 1.

  The inner stirring blade 11 is a central portion between the upper end edge and the lower end edge of the excavation / stirring shaft 1 between the upper end edge and the lower end edge of the outermost outer stirring blade 21 in a side view. It arrange | positions in the position superposed | polymerized with respect to the axial direction center part 1a. That is, the inner stirring blade 11 and the outer stirring blade 21 are substantially concentric as inner and outer blade layers with the axial center portion 1a as the center in a side view in a state where they are in phase with each other around the excavation / stirring shaft 1. It arrange | positions with respect to the digging and stirring axis | shaft 1 so that it may become arrangement | positioning (substantially ripple shape).

Incidentally, agitation diameter d of the outer agitation blades 21 in which the idler stirring blade 20 in the present embodiment, as shown in FIG. 3 (a) and 3 (b), and configured to be under excavation blade diameter or less Yes .

  More specifically, the outer stirring blade 21 is configured so that the length of the outer stirring blade 21 to the outer peripheral end in the radial direction is within the length range of the outer peripheral end in the radial direction of the excavation blade 2. Is disposed with respect to the excavation / stirring shaft 1.

  Here, “the stirring diameter of the outer stirring blade 21” is the outermost diameter of the outer stirring blade 21, and in the configuration in which the outer stirring blade 21 is provided with an accessory member, the outer stirring blade 21 including the accessory member. Of the outer diameter. The attached members attached to the outer stirring blade 21 will be described in detail later.

In this way, the excavation / stirring tool D1 shown in FIG. 3 is provided on the inner side of the driving agitating blade 11 that rotates integrally with the excavation / stirring shaft 1 and on the outer side of the driving agitating blade 10, and excavation / stirring is performed. formed arcuately bulged outwardly relative to the outer periphery of the shaft 1, the following effects by the outer stirring blade 21 rotating at a floating state with respect to the drilling and stirring shaft.

  That is, at the time of excavation / stirring, as shown in FIG. 19 (a), the agitated improved soil is transferred to the lower boss portion 22, the upper boss portion 23 around the excavation / stirring shaft 1, the outer stirring blade 21, and the inner stirring blade. 11 is the improved soil J that is guided to the vicinity of the outer agitating blade 21 having a low passage resistance because the peripheral frictional force and the member cross-section by the respective blade support portions 15 and 25 of the eleventh blade impede the passage through the inner central region of the agitating blade. A stationary stirring region L is formed in the vicinity of the outer peripheral wall of the excavation hole H by the part improved soil J1.

  In particular, each of the agitating blades 10 and 20 has a drilling and agitating shaft in a substantially concentric arrangement in the form of an inner and outer wing layer around the axial central portion 1a so that the blade main body portions 14 and 24 are substantially parallel to the axial direction. 1, the shear line S dividing the excavation / stirring soil during excavation / stirring into the rotary stirring region M and the stationary stirring region L is the blade main body 14 of the inner stirring blade 11 and the outer stirring blade. It becomes substantially linear so as to follow the shape of the inner stirring blade 11 in the axial direction or between the 21 blade body portions 24.

  For this reason, compared with the outer stirring blade 21 located in the stationary stirring region L, the shear resistance against the inner stirring blade 11 rotating in the rotating stirring region M is smaller, so that a shear line is surely generated and the excavation / stirring soil In order to prevent the co-rotation phenomenon, the stationary state of the outer peripheral improved soil J1 in the stationary stirring region L is made steady.

The stationary outer peripheral improved soil J1 in a stationary state gives resistance to the rotation direction of the outer stirring blade 21 which is the floating stirring blade 20, and the inner stirring blade 21 is constantly rotated as a stationary state or a driving stirring blade 10 at a constant rotation. The rotation speed can be delayed from that of the stirring blade 11, and the stirring blades arranged on the inner and outer two-stage blades (hereinafter also simply referred to as the two-stage blade type), that is, the outer stirring blade 21 and the inner stirring blade. 11 makes it possible to realize effective relative rotational stirring.

  In such excavation / stirring tool D, the stirring blades are arranged in so-called inner and outer three-stage blades as shown in FIG. 4 (hereinafter also simply referred to as a three-stage blade type), or as shown in FIG. It is also possible to configure by arranging the inner and outer four-stage blades (hereinafter also simply referred to as a four-stage blade type).

  The three-stage wing excavation / stirring tool D2 shown in FIG. 4 is excavated / introduced further inside the inner stirring wing 11 that is the drive stirring wing 10 of the two-stage wing excavation / stirring tool D1 shown in FIG. A core-side stirring blade 31 that is provided in a floating state with respect to the stirring shaft 1 and rotates integrally with the outer stirring blade 21 is provided.

  A lower boss portion 22 is loosely fitted around the outer periphery of the excavation / stirring shaft 1 further above the excavating blade 2, and an inner stirring blade boss portion 12 is loosely fitted around the outer periphery of the lower boss portion 22. . Further, an upper boss portion 23 is loosely fitted around the outer periphery of the excavation / stirring shaft 1 above the lower boss portion 22.

  The lower boss portion 22 is formed by extending the upper portion thereof in the axial direction up to the above-described axial center portion 1a position, and is loosely fitted around the outer periphery of the excavation / stirring shaft 1.

  The inner stirring blade boss portion 12 is loosely fitted around the outer periphery of the middle portion of the lower boss portion 22. Further, at the upper portion of the lower boss portion 22, that is, at the position of the central portion 1 a in the axial direction, the core side stirring blade 31 protrudes radially outward from the excavation / stirring shaft 1.

  The core side agitating blades 31 are formed in a plate shape in side view, and project from the outer peripheral surface of the upper part of the lower boss portion 22 to the outer side in the radial direction via the excavation / stirring shaft 1 in two symmetrical directions, The floating stirring blade 20 rotates integrally with the outer stirring blade 21.

  Further, the inner stirring blade 11 is provided in the outer peripheral surface of the excavation / stirring shaft 1 exposed between the core side stirring blade 31 and the upper boss portion 23 in the direction along the axial direction, and the lower end thereof is provided with the inner stirring. Drive agitating blades that are provided on the outer peripheral surface of the blade boss 12, are laid in two directions symmetrically via the excavation / stirring shaft 1 while straddling each boss, and rotate integrally with the excavation / stirring shaft 1. 10 is set.

  In this way, the outer side agitating blade 21, the inner side agitating blade 11, and the core side agitating blade 31 that are adjacent in the radial direction are, when viewed from the side, the upper and lower edges of the outermost outer agitating blade 21, the excavation / stirring shaft 1, The central portion 1a of the excavation / stirring shaft 1 between the respective connecting portions of the inner stirring blade 11 is substantially the center portion of the axis between the upper end and the lower end of the inner stirring blade 11 and the substantially central portion of the core side stirring blade 31. In order to superpose each other, they are arranged concentrically with respect to the excavation / stirring shaft 1 so as to form an inner and outer blade layer centered on the axially central portion 1a.

  That is, the outer stirring blade 21, the core-side stirring blade 31, and the inner stirring blade 11 that is the driving stirring blade 10, which are the floating stirring blade 20 and rotate integrally through the boss portion, are the floating stirring blade 20. The outer agitating blades 21 are alternately arranged at intervals along the arc-shaped outer shape of the agitating blades from the outer agitating blade 21 toward the inner side in the axial direction 1a.

  Accordingly, the arrangement position of the core side stirring blade 31 is the position of the central portion 1a in the axial direction on the axis between the upper end edge and the lower end edge of the outer stirring blade 21 with respect to the excavation / stirring shaft 1 in a side view.

  And the space | interval width formed by arrangement | positioning of these some stirring blades is made into the substantially same width | variety in side view.

  In the three-stage blade excavation / stirring tool D2 configured as described above, the shear line for the excavation / stirring soil during the excavation / stirring described above occurs as follows.

  That is, at the time of excavation / stirring, as shown in FIG. 19 (b), the agitated improved soil is transferred to the lower boss portion 22, the upper boss portion 23 around the excavation / stirring shaft 1, the outer stirring blade 21, and the inner stirring blade. 11, the peripheral frictional force and the member cross-section of the blade support portions 15 and 25 and the core-side stirring blade 31 impede the passage of the inner region of the stirring blade, leading to the vicinity of the outer stirring blade 21 with low passage resistance. A stationary stirring region L is formed near the outer peripheral wall of the excavation hole H by the outer peripheral improved soil J1.

  In particular, the outer sides are alternately arranged at intervals along the arc-shaped outer shape of the stirring blades from the core side stirring blades 31, the inner stirring blades 11, and the outer stirring blades 21 toward the inner side toward the axial central portion 1a. The shear line S between the agitating blade 21 and the inner agitating blade 11 with respect to the excavating and agitating soil is made substantially linear along the axial direction or along the shape of the inner agitating blade 11 that becomes the driving agitating blade 10. It is ensured that the stirring soil is divided into a rotating stirring region M and a stationary stirring region L.

The stationary outer peripheral improved soil J1 existing in the stationary stirring region L gives resistance to the rotation direction of the outer stirring blade 21 which is the floating stirring blade 20, and the outer stirring blade 21 is stationary or driven. The rotation speed is delayed as compared with the inner stirring blade 11 that constantly rotates at a constant speed.

  In particular, the shear line S <b> 1 for the excavation / stirring soil between the inner stirring blade 11 and the core stirring blade 31 is a substantially parallel line along the arc-shaped inner shape of the inner stirring blade 11 serving as the driving stirring blade 10. While the excavating and stirring soil in the vicinity of the core side stirring blade 31 that is interlocked via the blade 21 and the boss portion is in a substantially stationary state, the excavating and stirring soil in the vicinity of the inner stirring blade 11 is rotated and also in the layered inner side of each stirring blade. Relative agitation can be realized.

  Further, the four-stage blade excavation / stirring tool D3 shown in FIG. 5 includes the core-side stirring blade 31 as the second inner stirring blade 41 in the three-stage blade-type drilling / stirring tool D2 shown in FIG. Further, a core side stirring blade 32 that is provided inside the second inner stirring blade 41 and rotates integrally with the excavation / stirring shaft 1 is provided.

  More specifically, the lower boss portion 22 is formed by extending upward so that the upper portion of the lower boss portion 22 is positioned below the axial central portion 1a in the axial direction, and the substantially lower half portion of the excavation / stirring shaft 1 is formed. It is loosely fitted around the outer periphery to cover it. The inner stirring blade boss part 12 is loosely fitted around the outer periphery of the middle part of the lower boss part 22.

  Further, in the excavation / stirring shaft 1, the second inner stirring blade upper boss portion 43 is loosely fitted around the outer periphery between the axial center portion 1 a and the upper continuous portion of the inner stirring blade 11. .

  And, the second inner stirring blade 41 is provided in the direction along the axial direction with its upper end on the outer peripheral surface of the inner stirring blade upper boss portion 23a, and its lower end with respect to the outer peripheral surface of the lower boss portion 22. Two floating agitating blades 20 that rotate in unison with the outer agitating blade 21 via the lower boss portion 22 are installed in a symmetrical manner via the excavation / stirring shaft 1 in a state of straddling each boss.

  On the other hand, the core-side agitating blade 31 is located on the inner side of the second inner agitating blade 41, that is, between the upper boss portion 43 for the second inner agitating blade and the upper portion of the lower boss portion 22. Two symmetrically projecting from the excavation / stirring shaft 1 through the excavation / stirring shaft 1 in the axial center 1a position of the outer peripheral surface of the outer peripheral surface through the excavation / stirring shaft 1 and rotating integrally with the excavation / stirring shaft 1 The driving stirring blade 10 is used.

  That is, the inner stirring blade 11 and the core-side stirring blade 31, which are a plurality of inner and outer drive stirring blades 10, are provided on the outer periphery of the excavation / stirring shaft 1 so as to rotate integrally with the excavation / stirring shaft 1.

  On the other hand, the outer stirring blade 21 and the second inner stirring blade 41, which are a plurality of inner and outer floating stirring blades 20, rotate together via a boss part loosely fitted around the outer periphery of the excavation / stirring shaft 1. Thus, the excavating / stirring shaft 1 is provided in a floating state.

  The outer agitating blade 21, the inner agitating blade 11, the second inner agitating blade 41, and the core-side agitating blade 31 that are adjacent to each other in the radial direction are similar to the three-stage blade excavation / stirring tool D in the side view. The center of the axial line between the upper end edge and the lower end edge of the inner stirring blade 11 with respect to the axial central portion 1a on the excavation / stirring shaft 1 between the upper end edge and the lower end edge of the outermost outer stirring blade 21 Part, the substantially central part of the axis line between the upper end edge and the lower end edge of the second inner stirring blade 41, and the substantially central part of the core-side stirring blade 31 are superposed so as to form an inner and outer layer. It is arranged substantially concentrically around the part 1a.

  That is, the outer stirring blade 21 and the second inner stirring blade 41 which rotate integrally with the floating stirring blade 20 via the boss portion, and the driving stirring blade 10 which are integrated with each other via the excavation / stirring shaft 1. The rotating inner agitating blade 11 and the core-side agitating blade 31 are respectively driven by the stirrer agitating blade 20 and the drive agitating agitated at intervals along the arcuate outer shape of the agitating blade from the outer agitating blade 21 toward the inside in the axial direction 1a. The wings 10 are alternately arranged.

  Specifically, on the outermost side, an outer stirring blade 21 serving as a floating stirring blade 20 is located, and on the inner side, an inner stirring blade 11 serving as a drive stirring blade 10 is located. The second inner stirring blade 41 as 20 is located, and the core side stirring blade 31 as the drive stirring blade 10 is located further inside. Thus, the drive stirring blade 10 and the floating stirring blade 20 are provided so as to be alternately arranged from the radially outer side to the radially inner side of the excavation / stirring shaft 1.

  Such a configuration has the following effects despite having a plurality of stirring blades.

  That is, the outer periphery improved soil J1 that is guided to the vicinity of the outer stirring blade 21 having a low passage resistance and exists in the stationary stirring region L provides resistance to the rotation direction of the outer stirring blade 21, and the outer stirring blade 21 is in a stationary state or The second agitating blade 41 as the floating agitating blade 20 disposed through the outer agitating blade 21 and the boss portion, with the rotational speed being delayed from that of the inner agitating blade 11 that constantly rotates at a constant speed as the driving agitating blade 10. Since it becomes a substantially stationary state on the inner side, it is possible to realize double kneading and realize excellent kneadability.

  From the viewpoint of the shear line, at the time of relative rotational agitation, the shear line S for the excavation / agitation soil between the outer agitation blade 21 and the inner agitation blade 11 is axially or driven as in the case of the three-stage blade. The shape of the inner stirring blade 11 that becomes the blade 10 is made substantially parallel and substantially linear, and the inner stirring blade 11 and the second inner stirring blade 41, the second inner stirring blade 41, and the core-side stirring blade 31. Each shear line S1 with respect to the excavation / stirring soil between them can be a substantially parallel line along the shapes of the inner stirring blade 11 and the core-side stirring blade 31 serving as the driving stirring blade 10.

  In other words, the outer peripheral part of the stationary stirring region L in the vicinity of the outer peripheral part of the stirring diameter is improved by reliably generating a plurality of shear lines with respect to the excavation / stirring soil between the stirring blades having a multi-layer structure in a side view. The resistance force in the rotational direction due to the soil J1 can be transmitted to the central part of the stirring diameter, and the rocking phenomenon is caused by excavation and stirring soil in the substantially stationary state and the rotational stirring state from the inside to the outside of the stirring diameter. It is possible to improve the efficiency of relative rotation stirring while preventing the occurrence of the above.

  In this way, the outer agitating blade 21 is in a stationary state during the mixing and agitating operation regardless of the inner and outer agitating blade structure by the uniaxial excavating and agitating shaft 1, so that there is no entry member or the like to the unexcavated ground at the outer end. The outer stirring blade 21 is buried in excavated soil and is kept in a stationary state or the like, which is not necessary, and relative rotation stirring is performed with the rotation of the driving stirring blade 10 such as the inner stirring blade 11 in the center while preventing co-rotation. The same effect can be achieved, the cost of the apparatus itself is low, and the construction cost can be reduced.

[Modification 1]
Next, the excavation / stirring tool D4 according to the first modification of the present invention will be described with reference to FIG. 6 (a) and 6 (b) show side views of the excavation / stirring tool D4, and FIG. 6 (c) shows respective axial views.

  As shown in FIGS. 6 (a) and 6 (b), the outer stirring blade 21 of the excavation / stirring tool D4 according to the first modification has a member width W (W1, W2, W3) corresponding to the width of the blade-shaped surface in a side view. 6 (c), the width of the wing-shaped surface in the axial direction is defined as a member thickness T (T1, T2, T3), and the member thickness T is formed to be equal to or less than the member width W. . In the outer agitation blade 21, W1 and W3 indicate the member width of the blade support portion 25, and W2 indicates the member width of the blade main body portion 24 in the figure. Similarly, T1 and T3 indicate the member thickness of the blade support part 25, and T2 indicates the member thickness of the blade body part 24.

  In other words, the outer agitating blade 21 has a strip-like blade main body portion 24 and a blade supporting portion 25 that form the arc-shaped outer shape of the outer stirring blade 21 in a side view, and the blade main body portion 24 and the blade supporting portion 25. Is a direction perpendicular to the radial direction of the excavation / stirring shaft 1, that is, a tangential direction with respect to the circumference centering on the axis of the excavation / stirring shaft 1 in the plate thickness direction (member Thickness T1, T2, T3 direction).

  With such a configuration, the outer agitating blade 21 that is the floating agitating blade 20 does not need to transmit a rotational driving force, and therefore it is only necessary to consider the member rigidity against the axial resistance during penetration and extraction. The member rigidity in the direction orthogonal to the direction can be reduced.

  As shown in FIG. 6 (c), this reduces the blade area relative to the improved area of the outer stirring blade 21 as viewed in the axial direction in comparison with the configuration in which the magnitude relation between the member thickness and the member width is reversed. In addition, it is possible to reduce the passage resistance of the improved soil and excavated soil during stirring of the intrusion / extraction lifting operation. Furthermore, the blade shadow portion when the improved soil passes through the outer stirring blade is reduced, and adhesion of the improved soil to the blade shadow portion can also be reduced.

  Therefore, it is possible to improve the construction speed by increasing the passage promoting effect, and further, the outer stirring blade 21 can be formed in a thin plate shape and the adhesion of improved soil or the like to the outer stirring blade 21 can be reduced. It is possible to ensure good kneadability between the excavated soil and the improved material.

  It is also effective to suppress the passage resistance of the improved soil or the like during the stirring by chamfering or sharpening the thin plate-like facet of the outer stirring blade 21. Further, the width surface (member width W) of the outer agitating blade 21 is formed so as to ensure a necessary resistance area as a co-rotation preventing blade.

[Modification 2]
Next, the excavation / stirring tool D5 according to the second modification of the present invention will be described with reference to FIG. Fig.7 (a) shows the side view of excavation / stirring tool D5, FIG.7 (b) shows the axial view.

  As shown in FIG. 7A, the outer stirring blade 21 of the excavation / stirring tool D5 according to the modified example 2 is twisted with respect to the axial direction of the excavation / stirring shaft 1 or inclined with respect to the coaxial direction. It is configured so as to rotate due to soil resistance as the excavation / stirring shaft 1 moves up and down at the time of intrusion and extraction in ground improvement.

  In other words, as shown in FIG. 7A, the outer agitating blade 21 has a strip-like blade main body 24 and a blade support portion 25 that form the arc-shaped outer shape of the stirring blade in a side view. As shown in (b), the plate surfaces of the blade body 24 and the blade support portion 25 are inclined surfaces that are inclined with respect to the vertical direction, and the inclination is caused by the vertical movement when the excavation / stirring tool D is inserted and pulled out. It is configured to rotate by the soil resistance applied to the surface.

  Since the outer agitating blade 21 is formed in a “twisted shape” or an “inclined shape” as described above, the excavating / stirring shaft 1 is moved upward in the axial direction as shown in FIG. As described above, the soil resistance of the improved soil or the excavated soil acts on the upper surfaces 24a and 25a of the inclined surfaces of the blade body 24 and the blade support portion 25 in the axial upper view, and thus the upper surfaces 24a and 25a are aligned. In this way, a pressing force for pushing the outer stirring blade 21 downward in the axial direction and a pressing force with the lower surface 24b, 25b side of the inclined surface as a rotational direction are generated, and the outer stirring blade 21 is inclined. It rotates toward the lower surface 24b, 25b side direction of the surface.

  On the other hand, when the excavating / stirring shaft 1 is moved downward in the axial direction, the soil of the improved soil or excavated soil with respect to the lower surfaces 24b and 25b of the inclined surfaces of the blade body 24 and the blade support portion 25 as viewed in the axial direction. When the resistance acts, the pressing force for pushing the outer stirring blade 21 upward in the axial direction along the lower surfaces 24b and 25b and the upper surface 24a and 25a side direction of the inclined surface are set as the rotation direction. A pressing force is generated, and the outer stirring blade 21 rotates toward the upper surface 24a, 25a side of the inclined surface.

  In addition, even if the rotation direction of the outer stirring blade 21 that rotates in accordance with the vertical movement at the time of penetration / extraction of the excavation / stirring tool D5 is the same as the rotation direction of the driving stirring blade 10, the outer stirring blade 21 or Since the rotational speed of the other floating agitating blades 20 to be interlocked is not constant, relative rotational agitation by the drive agitating blades 10 and the floating agitating blades 20 is possible.

  As described above, according to the outer agitating blade 21 of the excavation / stirring tool D5 according to the modified example 2, the two-dimensional agitation and kneading of the excavated soil and the improved material located inside the outer agitating blade 21 are performed. The blade main body 24 and the blade support 25 can be widened over the entire width of the blade body 24 and the blade support 25 with respect to the rotation direction of the shaft 1, and the outer stirring blade 21 and other idle stirring blades 20 a linked thereto can be rotated in a fixed direction. It is possible to generate.

  In addition, the rotational direction is forcibly changed along with the vertical movement when the excavating / stirring tool D5 is inserted and pulled out, and the relative rotational stirring with the drive stirring blade 10 is further improved, so that the axial direction of the outer peripheral improved soil J1 is increased. The three-dimensional kneading and agitation between the excavated soil and the improved material can be steadily achieved while urging the passage up and down, and good kneadability can be ensured.

[Modification 3]
Next, the excavation / stirring tool D6 and the excavation / stirring tool D7 according to the third modification of the present invention will be described with reference to FIG. FIGS. 8A and 8B show axial views of the excavation / stirring tool D6 and the excavation / stirring tool D7, respectively.

As shown in FIG. 8 (a), the excavation / stirring tool D6 includes a core side stirring blade 31, an inner stirring blade 11, and an outer stirring blade 21, for example, soil characteristics such as N value, soft / hard ground, gravel, etc. A plurality of blades can be provided for each of the blades so as to correspond to the size of the stirring diameter d .

  That is, instead of extending the core-side stirring blade 31, the inner stirring blade 11, and the outer stirring blade 21 to the left and right, the three pieces are radially radiated at an angular interval of about 120 degrees around the excavation / stirring shaft 1 as viewed in the axial direction. Agitation efficiency is improved by extending the blades.

  Further, like the excavation / stirring tool D7 shown in FIG. 8B, the improvement material supply path E inside the excavation / stirring shaft 1 communicates with the radially outer tip of the blade support portion 15 of the inner stirring blade 11. The blade outlet 50 may be drilled.

  By comprising in this way, while improving material is uniformly disperse | distributed in excavated soil at the time of stirring rotation, the adhesion reduction effect of the improvement soil to the outer side stirring blade 21 arrange | positioned on the outer side, and the suppression effect of shear resistance This can contribute to the prevention of the co-rotation phenomenon. Further, the blade outlet 50 can improve the kneadability between the improved material and the excavated soil even at the outer periphery of the agitation, and can improve the quality of the improved soil.

[Modification 4]
Next, an excavation / stirring tool D8 according to Modification 4 of the present invention will be described with reference to FIG. FIG. 9 shows a side view of the excavation / stirring tool D8.

  As shown in FIG. 9, the excavation / stirring tool D8 has a lower boss portion 22 and an upper boss portion 23 formed by extending upward, and the disposition positions with respect to the excavation / stirring shaft 1 are reversed upside down. May be arranged.

  That is, the fixing structure of the inner stirring blade 11 that rotates integrally with the excavation / stirring shaft 1 is different from the basic structure, and the upper end is fixed to the inner stirring blade boss portion 12 that is loosely fitted to the upper boss portion 23, and the lower end is the excavation / stirring shaft. 1 is fixed.

[Modification 5]
Next, a digging / stirring tool D9 according to Modification 5 of the present invention will be described with reference to FIG. Fig.10 (a) shows the side view of excavation / stirring tool D9, FIG.10 (b) shows the axial view.

  The excavation / stirring tool D9 shown in FIG. 10 is configured such that the outer stirring blade 21 is formed in a thin plate shape, and rotates as an attachment member 60 at the distal end portion in the radial direction of the blade body 24 as shown in FIG. A reinforcing plate 61 for receiving resistance as much as possible is provided.

The reinforcing plate 61 functions as an edge cutting plate between the radially outer peripheral surface of the outer stirring blade 21 and the surrounding ground, a friction resistance plate, or a vertical centripetal guide plate of the improved body, and on the outer peripheral surface in the radial direction of the outer stirring blade 21. It arrange | positions so that it may become below the stirring diameter d.

  The cross-sectional shape of the outer stirring blade 21 provided with the reinforcing plate 61 may be T-shaped or L-shaped. In this modification, as shown in FIG. It is configured such that it is traced on the horizontal side surface 61a of the character.

  With such a configuration, the outer stirrer blade 21 is easily subjected to soil resistance from the improved soil around the outer peripheral surface of the outer stirrer blade 21 and the reinforcing plate 61 also receives frictional resistance of the wall surface of the excavation hole H. In addition, each of the floating stirring blades 20 interlocked with the outer stirring blades 21 can be brought into a substantially stationary state.

  In addition, the reinforcing plate 61 can also serve as a guide for the wall surface of the excavation hole H at the time of penetration / extraction at the time of agitation work, and also can suppress the misalignment reducing effect and the rolling out of the improved soil J due to the rotational centrifugal force.

[Modification 6]
Next, a digging / stirring tool D10 according to Modification 6 of the present invention will be described with reference to FIG. FIG. 11 shows a side view of the excavation / stirring tool D10.

  In the stirring tool D10 shown in FIG. 11, a detachable wing 62 is provided as an attachment member 60 on the upper horizontal piece of the outer stirring wing 21 so as to protrude upward in the axial direction, and the upper edge of the detachable wing 62 is horizontal. Is formed. The shape of the detachable wing 62 may be formed in an arc shape, a mountain shape, or a polygonal shape.

  More specifically, in the side view, the upper edge portion of the blade support portion 25 of the outer stirring blade 21 and the lower edge of the removable blade 62 are connected to the flat plate surface of the removable blade 62 and the belt plate surface of the blade support portion 25. Are arranged so as to be substantially flush with each other by attaching joints 62a that engage with engaging portions provided at a total of four locations, two on the front surface and two on the back surface of each stirring blade 21 and 62.

  In this way, by attaching the removable blade 62 to the outer stirring blade 21 to form the outer stirring blade 21, the area of the rotational resistance surface of the outer stirring blade 21 can be arbitrarily expanded and reduced, and is removable. When the blades 62 are attached, the soil resistance with respect to the rotational direction surface of the outer stirring blades 21 increases due to the outer peripheral improved soil J1 led to the vicinity of the stirring outer peripheral portions of the outer stirring blades 21 with low passage resistance. The phenomenon can be further prevented.

[Modification 7]
Next, an excavation / stirring tool D11 according to Modification 7 of the present invention will be described with reference to FIG. FIG. 12 shows a side view of the excavation / stirring tool D11.

  The excavation / stirring tool D11 shown in FIG. 12 is formed on the outer circumferential surface of the excavation / stirring shaft 1 exposed in the axial direction above the outer stirring blade 21, that is, above the upper boss portion 23 where the outer stirring blade 21 is disposed. A substantially flat horizontal stirring blade 70 (two in this modification, symmetrically via the excavation / stirring shaft 1) is provided so as to project outward in the radial direction.

  By providing the horizontal stirring blade 70 in this way, the improvement of the stirring effect and the unraveling effect of the improved soil at the time of extraction are enhanced, the passage resistance of the outer stirring blade 21 is reduced, and the efficiency of the stirring action can be improved.

[Modification 8]
Next, a digging / stirring tool D12 according to Modification 8 of the present invention will be described with reference to FIG. FIG. 13 shows a side view of the excavation / stirring tool D12.

  The excavation / stirring tool D12 shown in FIG. 13 includes a main body lower half portion 14a of the blade main body portion 14 of one inner stirring blade 11 and a main body upper half portion 14b of the other inner stirring blade 11 in the left and right inner stirring blades 11. Are formed in a shape bulging outward in the radial direction.

  That is, the shapes of the plurality of inner stirring blades 11 are arranged in a non-symmetrical shape with the excavation / stirring shaft 1 as the center line, or asymmetrically arranged, and the stirring blades in the excavated soil during stirring rotation The agitation effect can be improved by complicating the passage trajectory at (indicated by a broken line in the figure).

[Modification 9]
Next, an excavation / stirring tool D13 according to Modification 9 of the present invention will be described with reference to FIG. FIG. 14 shows a side view of the excavation / stirring tool D13.

  The excavating / stirring tool D13 shown in FIG. 14 has an excavating / stirring shaft 1 having an inner / outer double shaft structure capable of reciprocal rotation, and two excavating blades 2a, 2b at the lower ends of the two excavating / stirring shafts 1b, 1c. Are arranged in two stages.

Drilling blade 2 of the upper and lower stages have different drilling Kezutsubasa径, upper drilling blade 2a which is disposed on the upper side is equal to stir diameter d, also, the lower drilling blade 2b which is disposed below the upper drilling blades 2a Is formed so that the diameter of the excavation blade is smaller than that of the upper excavation blade 2a.

  The excavation / stirring shaft 1 includes a cylindrical outer shaft 1b and an inner shaft 1c that is rotatably inserted into the outer shaft 1b. The inner shaft 1c has an inner / outer double shaft structure in which the lower outer peripheral surface is exposed by extending downward in the axial direction from the outer shaft 1b.

  The upper excavation blade 2a is provided at the lower end of the outer shaft 1b, and the lower excavation blade 2b is provided at the lower end of the inner shaft 1c. The excavation of the ground G is performed while these two excavation blades 2a and 2b always rotate in opposite directions. It has a configuration that can be done.

With such a configuration, the misalignment phenomenon of the excavation / stirring shaft 1 seen during one-way rotational excavation can be prevented, and the centripetal property of the excavation / stirring shaft 1 can be improved.

In addition, the driving force of the rotational rotation by the rotational drive unit I is applied to the upper excavation blade 2a via the outer shaft 1b having a low rotational speed and a large rotational torque, for example, via the inner shaft 1c having a high rotational speed and a small rotational torque. the excavation Kezutsubasa径 small lower excavation blades 2b, by transferring respectively, can effectively divide the rotational torque required for drilling, thereby enabling improvement in drilling performance. In this way, it is possible to match the characteristics such as the rotational direction, rotational speed, and rotational torque of the reciprocal rotational driving force of the rotational drive unit I.

  Further, by arranging each stirring blade as described above on the outer periphery of the outer shaft 1b of the excavation / stirring shaft 1 configured in this way, the kneadability between the excavated soil and the improved material is improved, and the ground improvement work speed is increased. Can be improved.

[Modification 10]
Next, the digging / stirring tools D14, D15, D16 and the digging / stirring tools D17, D18, D19 according to Modification 10 of the present invention will be described with reference to FIGS. 15 and 16, respectively. FIG. 15 shows a side view in which the inner stirring blade is configured as a cantilever stirring blade in the excavation / stirring tools D14, D15, and D16, and FIG. 16 shows the outer stirring blade and inner stirring in the drilling / stirring tools D17, D18, and D19. The side view which comprised the wing | blade as a cantilever stirring blade is shown. FIGS. 15 (a) and 16 (a), FIGS. 15 (b) and 16 (b), FIGS. 15 (c) and 16 (c) are respectively a two-stage blade type, a three-stage blade type, and a four-stage blade type. A side view in the case of a stage blade type is shown.

  The excavation / stirring tools D14, D15, D16 and the excavation / stirring tools D17, D18, D19 shown in FIGS. 15 and 16 are swelled outward from the outer periphery of the excavation / stirring shaft 1 and formed into an arc shape. 21 and the inner stirring blade 11 have cantilever stirring blades having one end supported on the outer peripheral surface of the excavation / stirring shaft 1 or the outer peripheral surface of a boss part loosely fitted around the outer periphery of the excavation / stirring shaft 1. It is configured.

  The cantilever stirring blade is formed in a short arc shape by cutting a part of the upper end portion or the lower end portion of each stirring blade in the arc shape of the outer stirring blade 21 and the inner stirring blade 11. More specifically, any one of the upper and lower two blade support portions of each stirring blade is cut out.

  That is, the cantilever agitating blade is substantially arc-shaped, and the tip of the blade main body is directed substantially in the axial direction on the outer peripheral surface of the excavation / stirring shaft 1 or the outer peripheral surface of the boss part loosely fitted around the outer periphery of the excavation / stirring shaft 1. On the other hand, it is supported via a blade support part formed only in one of the upper and lower sides.

  For example, the inner stirring blade 11 of the excavation / stirring tools D14 and D15 shown in FIGS. 15A and 15B is a short arc cantilever stirring blade 81 obtained by cutting the lower blade support portion 15b. It is supported with respect to the digging / stirring shaft 1 only by the blade support portion 15a.

  Further, the excavation / stirring tool D16 shown in FIG. 15C is a short arc cantilever stirring blade 82 obtained by cutting the second inner stirring blade 41 inside the inner stirring blade 11 from the upper blade support portion 15a. The excavation / stirring shaft 1 is supported only by the lower blade support portion 15b.

  In addition, the excavation / stirring tools D17, D18, and D19 shown in FIGS. 16A to 16C only have the inner stirring blade 11 and the second inner stirring blade 41 as cantilever stirring blades 81 and 82, respectively. Instead, the outer stirring blade 21 is formed as a cantilever stirring blade 83. That is, the outer stirring blade 21 may be supported as the short arc cantilever stirring blade 83 by cutting the upper blade support portion 25a with respect to the excavation / stirring shaft 1 only by the lower blade support portion 25b. Good.

  With this configuration, when each agitating blade is provided, the boss portion loosely fitted around the outer periphery of the excavating / stirring shaft 1 can be omitted, and the excavating / stirring tool D can be downsized. It is not necessary to support at both ends with respect to the outer peripheral surface of the boss part loosely fitted around the outer periphery of the excavation / stirring shaft 1, and the manufacturing burden can be reduced.

[Modification 11]
Next, excavation / stirring tools D20, D21, D22, and D23 according to Modification 9 of the present invention will be described with reference to FIG. FIGS. 17A to 17D are side views of the excavation / stirring tools D20, D21, D22, and D23.

  Excavation / stirring tools D20, D21, D22, and D23 shown in FIG. 17 include a plurality of small protrusion-shaped auxiliary blades 90 on the circumferential surfaces of the stirring blades such as the outer stirring blade 21, the inner stirring blade 11, and the core-side stirring blade 31. By providing, the stirring effect can be improved.

  The excavation / stirring tools D20, D22, and D23 shown in FIGS. 17A, 17C, and 17D are provided for stirring resistance inside the outer stirring blade 21 or outside the inner stirring blade 11, respectively. The small protrusion-shaped auxiliary wings 90 are configured to protrude in a staggered manner in the direction facing each other in the radial direction.

  The auxiliary blades 90 do not need to be provided on a plurality of stirring blades, and a plurality of auxiliary blades 90 protrude from the radially inner and outer peripheral surfaces of the inner stirring blade 11 as in the excavation / stirring tool D21 shown in FIG. It is good.

  It should be noted that the auxiliary blades 90 alternately and projecting on the radially opposed peripheral surfaces of the respective stirring blades in the excavation / stirring tools D20, D22, and D23 of FIGS. 17 (a), 17 (c), and 17 (d). However, when the adhesive force is strong, when the stirring blades face each other, the plurality of auxiliary blades 90 overlap each other like comb teeth. It is formed in a length that does not match, and the shear line of the improved soil or excavated soil between the plurality of stirring blades is made substantially parallel to the shape of the inner stirring blade 11 that becomes the axial or driving stirring blade 10 By adopting a substantially linear arrangement, it is possible to prevent the occurrence of the co-rotation phenomenon without the outer stirring blade 21 following and rotating.

[Other variations]
Next, a modification of the outer stirring blade according to the present invention will be described with reference to FIG. 18 (a) to 18 (d) show side views of the excavation / stirring tools D24, D25, D26, and D27, respectively.

  The stirring blades according to the excavation / stirring tools D24, D25, D26, D27 are formed in an arc shape by bulging outward from the outer periphery of the excavation / stirring shaft 1 as described above. More specifically, the outer agitating blade 21 is formed in an arc shape in a side view, the radially outer end portion is a blade body portion, and both ends of the outer end portion are directed to the radial axis side. The extension part is a wing support part.

  For example, the outer agitating blade 21A of the excavation / stirring tool D24 shown in FIG. 18A is formed to have a substantially arc shape (semi-arc shape) in a side view, and the radially outer end is a blade main body portion 24A. An arc-shaped extension extending from both ends of the outer end toward the radial axis is used as a blade support 25A.

  The outer stirring blade 21B of the excavation / stirring tool D25 shown in FIG. 18B is formed so as to form a substantially triangular arc shape together with the portion between the lower boss portion 22 and the upper boss portion 23 of the excavation / stirring shaft 1 in a side view. The triangular apex that is the radially outer end is the blade body 24B, and the linear extension from both ends of the outer end toward the radial axis is the blade support 25B.

  The outer stirring blade 21C of the excavation / stirring tool D26 shown in FIG. 18 (c) forms a substantially hexagonal arc shape together with the portion between the lower boss portion 22 and the upper boss portion 23 of the excavation / stirring shaft 1 in a side view. One side that is formed and extends in the axial direction, which is the radially outer end, is a blade main body 24C, and a bent extension extending from both ends of the outer end toward the radial axis is a blade support 25C.

  Further, the “arc shape” of the stirring blade is supported on the outer peripheral surface of the excavation / stirring shaft 1 or the outer peripheral surface of the boss part loosely fitted around the outer periphery of the excavation / stirring shaft 1 in a side view. It is good also as a shape bulged to the axial direction upper side or / and the lower side rather than the site | part.

  For example, the outer stirring blade 21D of the excavation / stirring tool D27 shown in FIG. 18 (d) has a substantially hexagonal arc shape together with the portion between the lower boss portion 22 and the upper boss portion 23 of the excavation / stirring shaft 1 in a side view. In addition, the shape is formed so as to bulge to the upper side in the axial direction from the portion supported with respect to the outer peripheral surface of the upper boss portion 23. The outer agitating blade 21D has one side extended in the axial direction, which is the radially outer end portion, as a blade body portion 24D, and a bent extended portion extending from both ends of the outer end portion toward the radial axis side as a blade support portion 25D. It is said.

  As described above, according to the excavation / stirring tool according to the present invention, despite the single-shaft inner / outer stirring blade structure, the rotation of the outer stirring blade is suppressed during the mixing stirring operation so as to be stationary. Relative stirring can be achieved while preventing rotation, the cost of the apparatus itself is low, and the construction cost can be reduced.

  That is, according to the present invention, it is possible to provide a single-shaft-driven excavation / stirring tool that has excellent kneadability by multi-shaft kneading and agitation, workability with low penetration / drawing resistance, light weight and economy. it can.

  Finally, the description of each embodiment described above is an example of the present invention, and the present invention is not limited to the above-described embodiment, and each configuration disclosed in the above-described embodiment is mutually replaced or a combination is changed. Configurations, publicly known technologies, configurations disclosed in the above-described embodiments, configurations in which the configurations are mutually replaced, or combinations are changed are also included. Further, the present invention is not limited to the above-described embodiment, and various modifications can be made according to the design and the like as long as they do not depart from the technical idea according to the present invention. . It extends to the matters described in the claims and equivalents thereof.

A Base machine body B Leader C Improved material supply part D Excavation / stirring tool E Improved material supply path F Hanging wire G Unexcavated ground (ground)
H Drilling hole I Rotation drive part J Improved soil K Ground improvement device

DESCRIPTION OF SYMBOLS 1 Excavation and stirring shaft 2 Excavation blade 10 Drive stirring blade 11 Inner stirring blade 12 Inner stirring blade boss part 20 Free stirring blade 21 Outer stirring blade 22 Lower stirring blade 22 Lower boss part 23 Upper boss part 24 Blade body 31 Core side stirring blade

Claims (3)

In excavation and agitation tools for ground improvement by kneading excavated soil and improvement material while excavating and agitating the ground,
An excavation and stirring shaft extending vertically,
A drilling blade for drilling the ground, provided at the lower end of the drilling and stirring shaft;
At least with respect to the outer peripheral surface of the digging / stirring shaft bulging outward from the outer periphery of the digging / stirring shaft and formed into an arc shape or loosely fitted around the outer periphery of the excavation / stirring shaft A plurality of stirring blades supporting one end,
As the plurality of stirring blades,
A driving agitating blade that rotates integrally with the excavating and agitating shaft;
A floating stirring blade rotating in a floating state with respect to the excavation and stirring shaft,
Moreover, among the above stirring blades, the outermost outer stirring blade is a floating stirring blade ,
The outer stirring blade is
A blade body extending in the direction along the axial direction of the excavation and stirring shaft,
A blade support extending from the blade body to the excavation / stirring shaft,
The outer stirring blade is twisted with respect to the axial direction of the excavation / stirring shaft or inclined with respect to the coaxial direction so that the blade main body portion and the blade support portion have inclined surfaces inclined with respect to the vertical direction. No shape and none,
The soil that receives the slant surface when the outer stirrer blades are rotated by the soil resistance that the slant surface receives during the up-and-down movement at the time of penetration and withdrawal in ground improvement. An excavation / stirring tool configured to prevent the outer stirring blades from rotating together by causing the outer stirring blades to stand still or to be in a state where the rotational speed is delayed from that of the driving stirring blades by resistance .   2. The excavation / stirring tool according to claim 1, wherein the drive stirring blade and the floating stirring blade are alternately arranged at predetermined intervals from the outer stirring blade, which is a floating stirring blade, to the inner side.   The outer agitating blade is characterized in that the width of the blade-shaped surface in a side view is a member width, the width of the blade-shaped surface in an axial direction is a member thickness, and the member thickness is equal to or less than the member width. Or the excavation and stirring tool of 2.

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