Excavating and agitating apparatus
The excavating and stirring device with a radial and vertical blade configuration enhances mixing efficiency by preventing anti-corotation blades from rotating, effectively addressing mixing inefficiencies in clayey soil and improving the strength of columnar improved bodies.
Patent Information
- Application Number
- JP2024110669
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-07-10
- Publication Date
- 2026-01-23
AI Technical Summary
Conventional excavation and mixing devices face inefficiencies in soil mixing, particularly with clayey soil, leading to reduced strength of improved bodies.
The excavating and stirring device incorporates a rotating shaft with an excavating blade, agitating blades, and anti-corotation blades, featuring a radial and vertical configuration that allows for efficient mixing by preventing rotation of the anti-corotation blades in the ground, enhancing agitation and stirring efficiency.
The device improves mixing efficiency by effectively cutting and agitating the soil mixture at multiple points, ensuring thorough mixing even in clayey soil, resulting in improved strength of columnar improved bodies.
Smart Images
Figure 2026010735000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates to an excavation and stirring device. [Background technology]
[0002] A conventional ground improvement method involves excavating the ground while mixing excavated soil with a ground improvement material such as cement milk, and constructing columnar improved bodies in the ground. The ground improvement machine used for this type of ground improvement is equipped with an excavating and stirring device that excavates and stirs the ground. The excavating and stirring device includes an excavating blade that rotates integrally with the rotating shaft, an stirring blade that rotates integrally with the rotating shaft above the excavating blade, and an anti-corotation blade that is provided above the excavating blade and can rotate idly relative to the rotating shaft, and excavates and stirs the ground by rotating the rotating shaft (see, for example, Patent Document 1). The anti-rotation blades remain stationary in the ground during excavation and mixing, preventing the soil from rotating together with the excavation and mixing device, and cutting the soil between the anti-rotation blades and the mixing blades and excavation blades. This allows the excavation and mixing device to efficiently mix the soil whose rotation has been prevented by the anti-rotation blades. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] Japanese Patent Application Publication No. 2024-73332 Summary of the Invention [Problem to be solved by the invention]
[0004] However, with the above-mentioned conventional excavation and mixing devices, mixing may be insufficient due to factors such as soil quality, resulting in a decrease in the strength of the improved body. Mixing is particularly difficult when the ground contains clayey soil.
[0005] In view of these points, the present invention aims to improve the mixing efficiency of an excavation and mixing device. [Means for solving the problem]
[0006] The excavating and stirring device includes a rotating shaft that can rotate around an axis extending in a vertical direction, an excavating blade that is provided on the rotating shaft and rotates integrally with the rotating shaft, an agitating blade that is provided on the rotating shaft above the excavating blade and rotates integrally with the rotating shaft, and a co-rotation prevention blade that is provided above the excavating blade so as to be able to rotate idly relative to the rotating shaft, and excavates and stirs the ground by the rotation of the rotating shaft, and the agitating blade includes a first agitating blade that extends in a radial direction of the rotating shaft, and a second agitating blade above the first agitating blade. The anti-corotation blades comprise at least a first agitator blade and a second agitator blade extending radially from the rotating shaft, and the anti-corotation blades comprise a pair of lower blades extending radially outward on one side and the other from the rotating shaft below the first agitator blade, a pair of upper blades extending radially outward on one side and the other from the rotating shaft above the second agitator blade, and a pair of vertical blades connecting the lower blades and the upper blades vertically on the one side and the other side and positioned radially outward from the rotating shaft more than the agitator blade and the excavating blade. [Effects of the Invention]
[0007] According to the present invention, the mixing efficiency of the excavation and mixing device can be improved. [Brief explanation of the drawings]
[0008] [Figure 1] 1 is a side view of an excavating and stirring device according to an embodiment of the present invention. FIG. [Figure 2] FIG. 2 is a perspective view of the excavation and stirring device. DETAILED DESCRIPTION OF THE INVENTION
[0009] Hereinafter, an embodiment of an excavating and stirring device according to the present invention will be described with reference to the accompanying drawings.
[0010] Fig. 1 is a side view of an excavating and stirring apparatus 10 according to an embodiment of the present invention. Fig. 2 is a perspective view of the excavating and stirring apparatus 10. The excavation and mixing device 10 is used in a deep mixing treatment method in which excavated soil is mixed with a ground improvement material such as cement milk while excavating the ground to create a columnar improved body in the ground. The excavating and stirring device 10 is attached to a ground improvement machine that is installed on the ground. This ground improvement machine is equipped with a drilling rod 1 (FIG. 1) that is driven to rotate and can move up and down. The excavating and stirring device 10 is an excavating and stirring head that is detachably attached to the lower end of the drilling rod 1.
[0011] The drilling and stirring device 10 comprises a rotating shaft 11 connected to the lower end of the drilling rod 1, a drilling blade 12 attached to the rotating shaft 11 and rotating integrally with the rotating shaft 11, a stirring blade 13 attached to the rotating shaft 11 above the drilling blade 12 and rotating integrally with the rotating shaft 11, and an anti-rotation blade 14 attached above the drilling blade 12 so as to be able to rotate freely relative to the rotating shaft 11.
[0012] The center line of the rotating shaft 11 is an axis 11a extending in the vertical direction. The axis 11a is coaxial with the central rotation axis of the drilling rod 1, and when the drilling rod 1 is driven to rotate, the rotating shaft 11 rotates integrally with the drilling rod 1 around the axis 11a.
[0013] The excavating blade 12 comprises a columnar fixed part 20 attached to the lower end of the rotating shaft 11, a pair of excavating blade bodies 21 extending from the outer periphery of the fixed part 20 to one side and the other radially outward of the rotating shaft 11, a plate-shaped blade part 22 protruding downward from the lower part of the fixed part 20, and a discharge port 23 provided at the lower part of the fixed part 20. In the following description, the radial direction means the radial direction of the rotating shaft 11 unless otherwise specified.
[0014] The ground improvement material such as cement milk passes through the hollow drilling rod 1 and the rotary shaft 11 and is discharged to the excavation site from the discharge port 23. The discharge port 23 discharges the ground improvement material radially outward from the rotary shaft 11.
[0015] 2 shows the rotation direction R of the rotary shaft 11 when the excavating and stirring device 10 is lowered to excavate the ground. The rotation direction R is clockwise in FIG. The excavation blade body 21 has a plate shape extending radially perpendicular to the axis 11a in a side view. When viewed along the extension direction of the excavation blade body 21, the excavation blade body 21 is inclined so as to be positioned downward as it proceeds toward the rotation direction R. A plurality of claws 21 a extending obliquely downward along the slope of the excavation wing body 21 are provided on the lower edge of the excavation wing body 21 .
[0016] The agitating blade 13 includes a first agitating blade 31 provided above the excavating blade 12 and a second agitating blade 32 provided above the first agitating blade 31 . The first agitating blades 31 are provided as a pair so as to extend from the outer periphery of the rotating shaft 11 to one side and the other side of the rotating shaft 11 in the radial direction. The first agitating blade 31 is a plate-like blade extending radially perpendicular to the axis 11a in a side view. When viewed along the direction in which the first agitating blade 31 extends, the first agitating blade 31 is inclined so that it is positioned downward as it progresses toward the rotation direction R. When viewed in the axial direction (vertical direction) of the rotating shaft 11, the first agitating blade 31 is perpendicular to the excavating blade 12.
[0017] The second agitating blades 32 are provided as a pair so as to extend from the outer periphery of the rotating shaft 11 to one side and the other side of the rotating shaft 11 in the radial direction. The second agitating blade 32 is a plate-like blade extending radially perpendicular to the axis 11a in a side view. When viewed along the direction in which the second agitating blade 32 extends, the second agitating blade 32 is inclined so that it is positioned downward as it progresses toward the rotation direction R. When viewed in the axial direction of the rotating shaft 11 , the second agitating blade 32 is perpendicular to the first agitating blade 31 and parallel to the excavating blade 12 .
[0018] The anti-corotation blade 14 comprises a lower rotating portion 41 provided on the rotating shaft 11 between the agitator blade 13 and the first agitator blade 31, a pair of lower blades 42 extending radially outward from the lower rotating portion 41 on one side and the other, an upper rotating portion 43 provided above the second agitator blade 32 on the rotating shaft 11, and a pair of upper blades 44 extending radially outward from the upper rotating portion 43 on one side and the other. The anti-rotation wing 14 also includes a pair of vertical wings 45 that connect the lower wing 42 and the upper wing 44 vertically on one side and the other side in the radial direction, and a pair of inner wings 46 that extend radially inward from the vertical wings 45.
[0019] The lower rotating part 41 is a cylindrical member that fits onto the outer periphery of the rotating shaft 11. The lower rotating part 41 is provided so as to be rotatable relative to the rotating shaft 11 but immovable in the axial direction of the rotating shaft 11 (up and down direction). The lower blade 42 is in the form of a plate extending radially outward from the outer periphery of the lower rotating portion 41 . The lower wings 42 extend in the radial direction perpendicular to the axis 11a in a side view.
[0020] The upper rotating portion 43 is a cylindrical member that fits onto the outer periphery of the rotating shaft 11. The upper rotating portion 43 is provided so as to be rotatable relative to the rotating shaft 11 but immovable in the axial direction of the rotating shaft 11. The upper blade 44 is in the form of a plate extending radially outward from the outer periphery of the upper rotating portion 43 . The upper wing 44 is perpendicular to the axis 11a and parallel to the lower wing 42 in a side view. When viewed in the axial direction of the rotary shaft 11, the upper wing 44 and the lower wing 42 are provided in parallel, and the upper wing 44 and the lower wing 42 overlap in the axial direction. The anti-rotation vane 14 and the rotating shaft 11 are arranged to be rotatable relative to each other via the lower rotating part 41 and the upper rotating part 43. For this reason, if the rotating shaft 11 is rotated while the rotation of the anti-rotation vane 14 is restricted, for example, by the ground, the anti-rotation vane 14 will rotate freely relative to the rotating shaft 11.
[0021] The vertical wing 45 is a plate-like member that vertically connects the outer end of the lower wing 42 in the radial direction and the outer end of the upper wing 44 in the radial direction. In detail, the vertical wing 45 comprises a lower inclined portion 45a extending diagonally radially outward and upward from the outer end of the lower wing 42, an upper-lower extending portion 45b extending upward from the upper end of the lower inclined portion 45a parallel to the rotation axis 11, and an upper inclined portion 45c extending diagonally radially inward and upward from the upper end of the upper-lower extending portion 45b and connected to the outer end of the upper wing 44.
[0022] The pair of lower wings 42, the pair of upper wings 44, and the pair of vertical wings 45 form a substantially rectangular frame-shaped portion 47 in a side view. The frame-shaped portion 47 has a rectangular shape that is longer in the radial direction than in the vertical direction. When the frame-shaped portion 47 is viewed from the radially outer side along the longitudinal direction of the frame-shaped portion 47, the frame-shaped portion 47 has a flat plate shape that extends vertically in parallel with the rotation axis 11.
[0023] The surface of the lower blade 42 facing the rotation direction R is provided with a rib 42a extending in the radial direction. The upper wing 44 has a surface on the rotation direction R side thereof provided with a rib 44a extending in the radial direction.
[0024] The lower edge 45d of the lower inclined portion 45a is tapered so as to be positioned upward as it extends radially outward. The lower edge 45d is the lower edge of the outer end of the anti-rotation vane 14 in the radial direction of the rotating shaft 11. The upper edge 45e of the upper inclined portion 45c is tapered downward as it extends radially outward. The upper edge 45e is the upper edge of the outer end of the anti-rotation vane 14 in the radial direction of the rotating shaft 11.
[0025] The first agitating blade 31 and the second agitating blade 32 are provided inside the frame-shaped portion 47 of the anti-co-rotation blade 14. The vertical blades 45 of the frame-shaped portion 47 are located radially outward from the first agitating blade 31 and the second agitating blade 32, and surround the first agitating blade 31 and the second agitating blade 32 from the radially outer side. The inner blade 46 is a plate-like member extending radially inward from the vertical blade 45 toward the rotary shaft 11 side. The inner blade 46 is provided in the middle between the top and bottom of the vertical blade 45, and is located between the first agitating blade 31 and the second agitating blade 32 in the vertical direction. The inner blade 46 extends perpendicular to the rotation axis 11 in a side view, and can be parallel to the first agitating blade 31 and the second agitating blade 32. When viewed along the direction in which the inner blade 46 extends, the inner blade 46 is inclined so as to be positioned lower as it progresses toward the rotation direction R.
[0026] In the radial direction of the rotating shaft 11, the inner end 46a of the inner blade 46 extends inward relative to the outer end 31a of the first agitating blade 31 and the outer end 32a of the second agitating blade 32. In the radial direction, the outer end 31a and the outer end 32a are at the same position, and the first agitating blade 31 and the second agitating blade 32 have the same length. That is, the inner blade 46 overlaps with the first agitating blade 31 and the second agitating blade 32 in the radial direction of the rotating shaft 11 .
[0027] Furthermore, a gap is provided between the inner end 46a of the inner wing 46 and the outer periphery of the rotary shaft 11, and the inner wing 46 is not connected to the rotary shaft 11. Therefore, the anti-co-rotation wing 14 can rotate freely with respect to the rotary shaft 11. More specifically, the inner end 46a is provided between the rotary shaft 11 and the vertical wing 45, closer to the vertical wing 45.
[0028] Moreover, the vertical blades 45 are positioned radially outward of the outer ends 12a of the excavation blades 12. That is, the anti-co-rotation blades 14 have a larger diameter than the excavation blades 12.
[0029] Here, the excavation and mixing of the ground by the excavating and mixing device 10 will be described. The excavating and stirring device 10 rotates integrally with the excavating rod 1 of the soil improvement machine in a rotation direction R while descending toward the ground, thereby excavating the ground vertically. When drilling begins, a cylindrical drilled hole is formed by the drilling blade 12. The diameter of this drilled hole becomes equal to the outer diameter of the drilling blade 12. When the anti-rotation blade 14 descends to the position of the excavation hole, the pair of vertical blades 45 that protrude radially outward from the excavation hole descend while digging into the ground outside the excavation hole. The anti-rotation blade 14 stops rotating within the excavation hole as the vertical blades 45 dig into the ground, and the rotating shaft 11, drilling blade 12, first agitating blade 31, and second agitating blade 32 rotate relative to the stopped anti-rotation blade 14. In other words, the anti-rotation blade 14 stops rotating within the excavation hole as the vertical blades 45 dig into the ground, and the anti-rotation blade 14 spins freely relative to the rotating shaft 11.
[0030] In the excavation and mixing device 10, the vertical blades 45 formed by connecting the upper blades 44 and the lower blades 42 and extending vertically bite into the ground, so that the rotation prevention blades 14 can be firmly prevented from rotating. Furthermore, since the lower edge 45d of the lower inclined portion 45a of the vertical wing 45 is tapered downward, the vertical wing 45 can be easily driven into the ground.
[0031] A soil improvement material such as cement milk is supplied to the excavated hole from a discharge port 23, and the mixture of the excavated soil and soil improvement material produced by the excavation is stirred by the excavation stirring device 10. In detail, the mixture is agitated by the relative rotation of the excavating impeller 12 and the agitating impeller 13 with respect to the stopped co-rotation prevention impeller 14, so that the mixture is cut between the excavating impeller 12 and the lower blade 42, between the lower blade 42 and the first agitating impeller 31, between the first agitating impeller 31 and the inner blade 46, between the inner blade 46 and the second agitating impeller 32, and between the second agitating impeller 32 and the upper blade 44. In this way, the mixture can be agitated so as to be cut at multiple points above and below inside the frame-shaped co-rotation prevention impeller 14 in addition to between the excavating impeller 12 and the lower blade 42, resulting in good agitation efficiency. Furthermore, the mixture can be agitated in a cutting manner between the vertical blade 45 and the first agitating blade 31, and between the vertical blade 45 and the second agitating blade 32, resulting in good agitation efficiency.
[0032] Since the inner blade 46 is provided radially outward of the first agitator blade 31 and the second agitator blade 32 and between the first agitator blade 31 and the second agitator blade 32, the radially outer positions of the first agitator blade 31 and the second agitator blade 32 can be agitated by the inner blade 46, and a wide radial range can be agitated. In addition, the mixture present on the radially outer side in the drilled hole can be moved radially inward by the inner blades 46, promoting the multi-directional movement of the mixture and improving the mixing efficiency.
[0033] When the excavation hole reaches a predetermined depth and mixing of the mixture is completed, the excavation and mixing device 10 is pulled up together with the drilling rod 1, and a columnar improved body is created in the ground as the mixture solidifies. In the excavating and stirring device 10, the upper edge 45e of the vertical blade 45 of the rotation prevention blade 14 is tapered upward, so that the rotation prevention blade 14 can be smoothly pulled upward.
[0034] As described above, according to an embodiment of the present invention, the excavating and stirring device 10 includes a rotating shaft 11 that can rotate around an axis 11a extending in the vertical direction, an excavating blade 12 that is attached to the rotating shaft 11 and rotates integrally with the rotating shaft 11, an agitating blade 13 that is attached to the rotating shaft 11 above the excavating blade 12 and rotates integrally with the rotating shaft 11, and an anti-co-rotation blade 14 that is attached to the rotating shaft 11 above the excavating blade 12 and can rotate freely, and excavates and stirs the ground by the rotation of the rotating shaft 11. The agitating blade 13 includes a first agitating blade 31 that extends radially from the rotating shaft 11, and a second agitating blade 32 that extends radially from the rotating shaft 11 above the first agitating blade 31. The anti-rotation blades 14 comprise a pair of lower blades 42 extending radially outward on one side and the other from the rotating shaft 11 below the first agitator blade 31, a pair of upper blades 44 extending radially outward on one side and the other from the rotating shaft 11 above the second agitator blade 32, and a pair of vertical blades 45 connecting the lower blades 42 and the upper blades 44 vertically on one side and the other, and positioned radially outward from the rotating shaft 11 more than the agitator blades 13 and the drilling blades 12. According to this configuration, the pair of vertical blades 45 vertically connect the lower blade 42 located below the first agitating blade 31 and the upper blade 44 located above the second agitating blade 32, ensuring a large vertical length. Therefore, the long vertical blades 45 can firmly hold the anti-rotation blade 14 stationary in the ground, suppressing rotation of the anti-rotation blade 14 and improving agitation efficiency. Furthermore, because the first agitating blade 31 and the second agitating blade 32 are positioned between the lower blade 42 and the upper blade 44, soil can be agitated at multiple locations above and below between the lower blade 42 and the first agitating blade 31 and between the second agitating blade 32 and the upper blade 44, improving agitation efficiency. Therefore, even if the ground is, for example, clayey soil, it can be agitated appropriately.
[0035] The anti-rotation vane 14 also includes an inner vane 46 extending radially inward from the vertical vane 45 . According to this configuration, the inner blade 46 can stir the area radially outward of the stirring blade 13, and the stirring blade 13 and the inner blade 46 can stir a wide range in the radial direction, thereby improving the stirring efficiency.
[0036] The inner blade 46 is located between the first agitating blade 31 and the second agitating blade 32 in the vertical direction. According to this configuration, stirring can be performed at multiple locations between the inner blade 46 and the first agitating blade 31 and between the inner blade 46 and the second agitating blade 32, thereby improving the stirring efficiency.
[0037] In addition, in the radial direction of the rotary shaft 11, the inner end 46a of the inner blade 46 extends inward relative to the outer end 31a of the first agitating blade 31 and the outer end 32a of the outer agitating blade of the second agitating blade 32. According to this configuration, the mixing blade 13 and the inner blade 46 overlap in the radial direction of the rotating shaft 11, so that the soil can be cut effectively between the mixing blade 13 and the inner blade 46, resulting in good mixing efficiency.
[0038] Furthermore, the lower edge 45d of the outer end of the anti-rotation vane 14 in the radial direction of the rotary shaft 11 is tapered so as to be positioned higher as it goes radially outward. According to this configuration, the lower edge 45d of the outer end of the anti-rotation vane 14 is tapered, which reduces resistance when inserting the anti-rotation vane 14 into the ground, making it easier to install the anti-rotation vane 14 in the ground.
[0039] Although one embodiment of the present invention has been described above, the present invention is not limited to the specific embodiment, and unless otherwise limited in the above description, various modifications and variations are possible within the spirit and scope of the present invention as defined in the claims. For example, the configurations of the above-described embodiment may be added or deleted as appropriate, and the configurations of one embodiment may be incorporated into other embodiments. Furthermore, the effects of the above-described embodiment are merely examples of the effects resulting from the present invention, and do not mean that the effects of the present invention are limited to the above-described effects. In the above embodiment, the agitator blade 13 has been described as including the first agitator blade 31 and the second agitator blade 32, but the present invention is not limited to this. The agitator blade 13 only needs to include at least the first agitator blade 31 and the second agitator blade 32, and for example, a third agitator blade may be provided above the second agitator blade 32 on the rotating shaft 11. Furthermore, multiple inner blades 46 may be provided at different positions in the vertical direction, and for example, the inner blade 46 may be provided between the second agitator blade 32 and the third agitator blade. Furthermore, the inner blade 46 may be provided above or below the agitator blade 13. In addition, although the inner blades 46 have been described as being inclined so as to be positioned downward as they proceed toward the rotation direction R, there are no particular limitations on the inclination angle of the inner blades 46. For example, the inner blades 46 may be in the shape of a flat plate parallel to the vertical blades 45. [Explanation of symbols]
[0040] 10: Excavation and mixing device 11: Rotation axis 11a: Axis 12: Drilling wing 13: Mixing blade 14: Anti-corotation wing 31: First stirring blade 31a: Outer edge 32: Second mixing blade 32a: Outer edge 42:Lower wing 44: Upper wing 45: Vertical wing 45d: lower edge 46:Inner wing 46a: Inner edge
Claims
1. A drilling and stirring device that includes a rotary shaft that can rotate around an axis extending in the vertical direction, an excavation blade that is provided on the rotary shaft and rotates integrally with the rotary shaft, an agitation blade that is provided on the rotary shaft above the excavation blade and rotates integrally with the rotary shaft, and an anti-rotation blade that is provided above the excavation blade and can rotate idly relative to the rotary shaft, and that excavates and stirs the ground by rotating the rotary shaft, The stirring blade includes at least a first stirring blade extending in a radial direction of the rotating shaft and a second stirring blade extending in a radial direction of the rotating shaft above the first stirring blade, The anti-rotation blades are a drilling and stirring device comprising a pair of lower blades extending radially outward on one side and the other of the rotating shaft below the first stirring blade, a pair of upper blades extending radially outward on one side and the other of the rotating shaft above the second stirring blade, and a pair of vertical blades connecting the lower blades and the upper blades vertically on one side and the other side, and positioned radially outward on the rotating shaft than the stirring blades and the drilling blades.
2. The excavating and stirring device according to claim 1 , wherein the anti-corotation blade comprises an inner blade extending radially inward from the vertical blade.
3. The excavating and stirring device according to claim 2, wherein the inner blade is positioned between the first stirring blade and the second stirring blade in the vertical direction.
4. The excavating and stirring device according to claim 2 or 3, wherein the inner end of the inner blade extends inward relative to the outer end of the stirring blade in the radial direction of the rotating shaft.
5. The excavating and stirring device according to claim 1, wherein the lower edge of the outer end of the anti-rotation blade in the radial direction of the rotating shaft is tapered so as to be positioned upward as it extends radially outward.
Citation Information
Patent Citations
Excavation and stirring device
JP2024073332A