JP3707146B2 - Stirring head of ground improvement equipment - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a stirring head of a ground improvement device, and more particularly, to a stirring head of a ground improvement device that stirs and kneads excavated soil and a hardener in a drilling hole formed by excavating the ground in a vertical direction.
[0002]
[Prior art]
As a stirring head of the above ground improvement device, there is a conventional one described in JP-A-3-63312, for example.
[0003]
This stirring head is attached to an upper position of a drilling blade provided at the tip of a counter rotating rotating shaft composed of an outer shaft and an inner shaft, and a semicircular arc small stirring blade body at its upper and lower ends. A semi-arc-shaped large stirring blade is fixed to the inner shaft, and the upper end of the large stirring blade is fixed to the outer shaft above the position of the small stirring blade, and the lower end is connected to the inner shaft below the position of the small stirring blade. A plurality of small stirring blade bodies are arranged on the inner side of the large stirring blade body so as to be axially supported, and a plurality of radial blades are arranged perpendicularly to the rotation axis. The stirring head is formed with an injection port for injecting the curing agent.
[0004]
In order to improve the ground with the ground improvement device to which the agitation head is attached, the rotary shaft is driven to rotate and the excavation blade is rotated and lowered to form a cylindrical excavation hole in the ground. When the excavating blade reaches a predetermined depth, the descent of the rotary shaft is stopped, the hardener is supplied from the hardener pump provided on the ground into the rotary shaft, and the hardener nozzle provided at the lower end of the excavating shaft is inserted into the drilling hole. Then, each agitating blade of the agitating head is rotated in the opposite direction to agitate and knead the excavated soil and the hardener, and the rotating shaft is raised to form a ground improvement portion in the excavation hole.
[0005]
In addition, as the agitation head of the ground improvement device, both the large and small agitating blades are formed in a square shape when rotated around the excavation axis with a square shape (see FIG. 4 of the same publication). A flat plate that is projected radially from the excavation shaft (see Japanese Patent Laid-Open No. 1-36817), and a combination of a rectangular large and small stirring blade and a substantially flat blade (Japanese Patent Laid-Open No. 5-331934). Various airfoil shapes and configurations have been proposed so that the agitation and mixing of the excavated soil and the hardener in the excavation hole can be performed better.
[0006]
[Problems to be solved by the invention]
In the agitation head of such a conventional ground improvement device, in order to prevent the excavated soil and the hardener in the excavation hole from co-rotating with the agitation blade, two types of reversing agitation blades are provided inside and outside. However, there is a demand that stirring and kneading cannot be performed at a sufficient speed yet and good stirring and kneading is desired at a higher speed.
[0007]
This invention is made | formed in view of the said subject, and it aims at providing the stirring head of the ground improvement apparatus which can stir and knead excavated soil and a hardening | curing agent satisfactorily at a high kneading speed.
[0008]
[Means for Solving the Problems]
As shown in FIG. 1, the means of the present invention for solving the above problems is mounted on a drilling shaft 10 having an inner shaft 12 and an outer shaft 11 that rotate in opposite directions, and is excavated in the drilling hole. In the agitation head 20 for agitating and kneading the hardener and the curing agent, the agitation heads 20 and 50 rotate together with the inner agitation blades 21 and 51 together with the inner shaft 12 and the outer shaft 11, and are outside the inner agitation blades 21 and 51. The inner stirring blades 21 and 51 are arranged in a plurality of stages by shifting the radial stirring blades 22 and 52 radially arranged in the axial direction. At least one of the agitating blades 22 and 52 is provided with injection nozzles 23 and 53 for injecting a curing agent from the outer edge thereof in the direction of rotation, and the outer agitating blades 25 and 55 are provided. The A rotation trajectory passes between the stirring blades 22 and 52 inward from the frame-like stirring blades 26 and 56 and the frame-like stirring blades 26 and 56 surrounding the rotation trajectory of the inner stirring blades 21 and 51. It is comprised from the protruding wings 27 and 57 projected.
[0009]
Furthermore, in the present invention, the stirring head 50 can be provided with a digging blade 58 at the lower end of the outer stirring blade 55, and the stirring head 50 rotates with the inner shaft 12. The center excavation blade 59 having a smaller diameter than the excavation blade 58 can be provided.
[0010]
[Action]
The agitation heads 20 and 50 of the ground improvement device of the present invention are used by being connected to the tip of the excavation shaft 10 mounted on the ground improvement device equipped with the excavator. The excavator lowers the outer shaft 11 and the inner shaft 12 of the rotating shaft 10 while rotating them in opposite directions, and drills a cylindrical drilling hole in the ground with excavating blades 28 and 58 provided at the tip of the stirring head 20. To do. The inner stirring blades 21 and 51 and the outer stirring blades 22 and 52 of the stirring heads 20 and 50 are rotationally driven in directions opposite to each other and are pumped from the injection nozzles 23 and 53 into the inner shaft 12 of the excavation shaft 10. Curing agent is ejected.
[0011]
At this time, the spray nozzles 23 and 53 spray the curing agent from the tips of the radial stirring blades 24 and 54 while descending, so that the injected curing agent enters the excavated soil. It descends while rotating in the direction, and comes to draw a spiral in the excavation soil in the excavation hole. For this reason, the drilling flow of the hardener stirs the excavated soil with the flow force, and the hardener and the excavated soil are kneaded well. The excavated soil and the hardener are stirred and kneaded by the radial stirring blades 22 and 52 of the inner stirring blades 21 and 51, the frame-shaped stirring blades 26 and 56 of the outer stirring blades 25 and 55, and the protruding blades 27 and 57.
[0012]
At this time, since the inner stirring blades 21 and 51 and the outer stirring blades 25 and 55 rotate in the opposite direction, the radial stirring blades 22, 24, 52 and 54 of the inner stirring blades 21 and 51, and the outer stirring blade 25 , 55 and the projecting blades 27, 57 rotate in reverse so that a complicated shearing force is applied to the excavated soil mixed with the hardener, and the excavated soil and the hardener Is well stirred without causing co-rotation.
[0013]
Further, in the stirring head 50 provided with the excavating blade 58 at the lower end of the outer agitating blade 55, the excavating blade 58 is driven by the outer shaft 11 having a large rotational torque, so that the ground is excavated with a large excavating force. Can do.
[0014]
In the agitation head 50 provided with the central excavation blade 59 that rotates together with the inner shaft 12, the central excavation blade 58 is provided in the central excavation blade 58 provided on the outer agitation blade 55. 59, and the stirring head 50 as a whole can have a good excavating force.
[0015]
Embodiment
Embodiments of a stirring head of a ground improvement device according to the present invention will be described below in detail with reference to the drawings.
[0016]
[Configuration of First Embodiment]
FIG. 1 thru | or FIG. 3 is a block diagram which shows 1st Embodiment of the stirring head of the ground improvement device based on this invention.
This example corresponds to claim 1 of the appended claims.
[0017]
In the ground improvement device in which the stirring head 20 of this example is used, as the excavation shaft 10, the outermost excavation hollow shaft is the outer shaft 11, the inner excavation hollow shaft is the inner shaft 12, and is located in the center. A triple multi-axis having a hollow axis for supplying a curing agent or the like as a central axis 13 is used. Then, the agitation head 20 is attached to the lower end of the excavation shaft 10 via the attachment portion 15.
[0018]
The agitation head 20 includes a head shaft portion 31 formed coaxially with the excavation shaft 10. The head shaft portion 31 includes an inner agitation blade 21 and an outer agitation blade 25, and an excavation blade 28 is provided.
[0019]
The head shaft portion 31 includes an outer head shaft portion 32 connected to the outer shaft 11 at the upper end thereof, and an inner head shaft portion 33 connected to the inner shaft 12 and the central shaft 13 at the upper end thereof. . The slide bearing 16 is fitted into the lower end of the outer head shaft portion 32, and the outer head shaft portion 32 and the inner head shaft portion 33 are coaxial and can be rotated in the opposite direction.
[0020]
The inner head shaft portion 33 includes an outer cylinder portion 34 and an inner cylinder portion 35 from the vicinity of the lower end portion to the upper end thereof. The outer cylinder portion 34 is provided on the inner shaft 12 of the excavation shaft 10, and the inner cylinder portion 35 is excavated. A curing agent pumping path 36 that is connected to the central shaft 13 of the shaft 10 and communicates with a gap between the inner shaft 12 and the central shaft 13 through which the curing agent is pumped is formed between the cylindrical portions 34 and 35. The
[0021]
In addition, the inner head shaft portion 33 is formed integrally with the lower end portion of the inner head shaft portion 33 so that the hardener pressure feed path 36 between the cylinder portions 34 and 35 is not extended. A feeding passage 37 is formed and communicates with the inner hole of the central shaft 13.
[0022]
In this example, a digging blade 28 is attached to the lower end portion of the inner head shaft portion 33, and a discharge port 30 for the hardener liquid is opened at the lowermost end surface of the digging blade 28. 37 is communicated with the inner hole of the central shaft 13 through 37. In addition, a notch 39 is provided immediately below the inner shaft of the excavating blade 28 so that the hardener from the discharge port 30 can flow out.
[0023]
The inner stirrer blades 21 are arranged in three stages with two straight bar-shaped radial stirrer blades 22 radially arranged across the diameter of the inner head shaft portion 33 in the axial direction. The two radial stirring blades 24 located at the lowermost stage are configured to include an injection nozzle 23 that ejects a curing agent from the outer edge portion in the rotational traveling direction.
[0024]
A curing agent passage 37 is formed in the radiation agitating blade 24 so as to communicate the injection nozzle 23 with the curing agent pumping passage 36 formed in the head shaft portion 31.
[0025]
The outer stirring blade 25 has a frame-like stirring blade 26 formed so that the rotation locus of the outer stirring blade surrounds the rotation locus of the inner stirring blade 31, and the radial stirring blade 22 inward from the frame-like stirring blade 26. , 24 and two projecting wings 27 projecting from each other.
The frame-shaped stirring blade 26 includes an upper horizontal blade 26a formed obliquely downward from the lower end portion of the outer head shaft portion 32, a vertical blade 26b formed downward from the tip of the upper horizontal blade 26a, and the vertical blade 26a. The lower wing 26b is formed in a substantially U shape from the lower horizontal wing 26c attached to the annular mounting portion 38 that is formed obliquely downward from the lower end of the wing 26b toward the inner shaft and is inserted on the inner head shaft portion 33. ing.
[0026]
The annular mounting portion 38 is fitted with a sliding bearing 42 and is rotatably mounted on the outer periphery of the inner head shaft portion 33.
[0027]
The stirring head according to this example is used by being mounted on a ground improvement device.
FIG. 8 shows an example of a ground improvement device 70 equipped with the stirring head 20 according to this example.
[0028]
In this ground improvement device, two agitation heads 20 and 20 are arranged so that the ends of the circular excavation range are overlapped, and the excavation is performed by rotating the phases so that the blades of both agitation heads 20 and 20 do not interfere with each other. In addition, mixing and stirring of the curing agent is performed to form a ground improvement portion. For this reason, the ground improvement device lowers two excavation shafts 10 while synchronously rotating them in opposite directions, and continues excavation shafts 10 as necessary to further excavate and stir and knead the hardener. is there.
[0029]
The ground improvement device includes a leader 72 upright by a base machine 71, a guide rail 73 disposed along the leader 72, and a motor disposed on the guide rail 73 so as to be movable up and down and disposed below the leader 72. An excavation shaft drive device 74 that rotates the outer shaft of the excavation shaft 10 and a reverse transmission device that is disposed above the excavation shaft drive device 74 and transmits the rotation of the outer shaft to the inner shaft. The excavating shaft lifting device 75 is mounted on the rail 73 so as to be movable up and down, and the lifting drive device (not shown) that includes a wire rope and a guide pulley and moves the excavating shaft lifting device up and down.
[0030]
The excavation shaft drive device 74 is supported only by the guide rail 73 and is connected integrally with an excavation shaft lifting device 75 that supports the upper portion of the excavation shaft 10 when two excavation shafts 10 are fitted in parallel. In this state, it moves up and down according to the vertical movement of the excavating shaft lifting device 75.
The excavating shaft lifting device 75 is supported by the guide rail 73 and connected to a chain driving device (not shown) provided on the reader 72, and moves up and down according to the operation of the chain driving device. The excavation shaft lifting and lowering device 75 has two excavation shafts 10 and 10 attached to the lower portion thereof in parallel via an outer shaft connection portion and an inner shaft attachment portion (not shown). Are added one after another along with the progress of excavation and mixing of the excavated soil and the hardener.
[0031]
In this example, the hardener is pumped from a liquid injection device (not shown) provided at the top of the excavating shaft lifting device. This liquid injection device is composed of a double swivel joint for pumping the hardener between the inner shaft 12 and the central shaft 13 of the excavating shaft 10 and for feeding the hardener into the inner hole of the central shaft 13. .
[0032]
[Operation and Effect of First Embodiment]
In order to improve the ground using the ground improvement device to which the stirring head 20 according to this example is attached, the excavation shaft driving device 74 is operated by starting the motor of the ground improvement device and excavating while feeding the hardener. The shaft 10 is lowered while being driven to perform excavation of the ground, injection of a hardener into the excavated soil, and stirring and kneading.
[0033]
When the excavation shaft 10 is lowered, the outer agitating blade 21 and the outer agitating blade 25 of the agitation head 20 are rotationally driven together with the excavation blade 28 in a predetermined direction, and from the injection nozzle 23 to the inner shaft 12 and the central axis of the excavation shaft 10. 13 is jetted at a high pressure.
[0034]
At this time, the spray nozzle 23 sprays the curing agent from the tip of the radiation stirring blade 24 in the traveling direction of the radiation stirring blade 24 while descending. The injected hardener is excavated by the excavating blade 28 and injected into the excavated soil agitated by the outer agitating blade 25 and mixed with the excavated soil. At this time, the curing agent descends while rotating the infiltration direction, and is injected so as to draw a spiral in the excavation soil in the excavation hole. The ejection flow of the hardener stirs the excavated soil with the flow force, and the hardener and the excavated soil are kneaded. Further, the excavated soil mixed with this hardening liquid is stirred and kneaded by the radial stirring blades 22 and 24 of the inner stirring blade 21 and the frame-shaped stirring blade 26 and the protruding blade 27 of the outer stirring blade 25.
[0035]
In this example, the inner stirring blade 21 and the outer stirring blade 25 rotate in opposite directions, and the radial stirring blades 22 and 24 of the inner stirring blade 21, the frame-shaped stirring blade 26 and the protruding blade 27 of the outer stirring blade 25. Since the excavated soil mixed with the hardener is subjected to a complex shearing force, the excavated soil and the hardener are well agitated without causing co-rotation.
[0036]
Moreover, according to this example, since the two stirring heads 20 are arranged in parallel, the ground having a large area can be improved by one excavation and extraction.
[0037]
Then, the excavation shaft 10 is added from above until reaching a predetermined depth, excavation stirring and kneading are performed, and after reaching the predetermined depth, the agitation head 20 is pulled out. At this time, when the excavating shaft 10 is pulled out while being rotated, the excavated soil and the hardener are further stirred and kneaded.
As the excavating shaft 10 is pulled out when the stirring head 20 is pulled out, the excavating shaft for relay is sequentially removed from above, and this operation is continued until the stirring head appears on the ground surface.
[0038]
As described above, in the stirring head 20 of the first example of the embodiment, the curing agent is excavated by the excavating blade 28 and further rotated in the direction opposite to the excavating blade 28. It is injected into the excavated soil agitated at 26c. For this reason, the hardener is well mixed with the excavated soil. A complex shearing force is applied by the inner stirring blade 21 and the outer stirring blade 25 in the excavated soil in which the curing agent is mixed. Therefore, in the agitation head 20, the excavated soil can be prevented from co-rotating, and the excavated soil and the curing agent can be agitated and kneaded with high efficiency.
[0039]
[Configuration of Second Embodiment]
4 to 7 show a specific structure of the second embodiment of the stirring head of the ground improvement device according to the present invention.
This example corresponds to claim 2 of the claims.
[0040]
The stirring head 50 in this example is attached to the tip of the triple excavation shaft 10 including the outer shaft 11, the inner shaft 12, and the central shaft 13 as in the first embodiment.
[0041]
The stirring head 50 includes a head shaft portion 31 having the same structure as that of the stirring head of the first example described above. Therefore, regarding the configuration of the head shaft portion 31, the same members as those in the head shaft portion of the first example are denoted by the same reference numerals in the drawing, and detailed description thereof is omitted.
[0042]
Similarly to the first stirring head described above, the inner stirring blade 51 is configured by shifting two linear rod-shaped radiation stirring blades 52 radially arranged across the inner head shaft portion 33 in the axial direction. The two radial stirrer blades 54 arranged in stages and positioned at the lowermost stage of the radial stirrer blades 52 are each provided with an injection nozzle 53 that ejects a curing agent from the outer edge portion in the rotational traveling direction.
A curing agent passage 60 is formed in the radiation agitating blade 54 to communicate the injection nozzle 53 with the curing agent pressure feed passage 36 formed in the head shaft portion 31.
[0043]
The outer stirring blade 55 has a frame-shaped stirring blade 56 formed so that its rotation locus surrounds the rotation locus of the inner stirring blade 51, and the frame-shaped stirring blade 56 faces inward from the frame-shaped stirring blade 56. It consists of two projecting wings 57 projecting so as to pass between them.
[0044]
The frame-shaped stirring blade 56 includes an upper horizontal blade 56a formed obliquely downward from the lower end portion of the outer head shaft portion 32, a vertical blade 56b formed downward from the tip of the upper horizontal blade 56a, and the vertical blade 56a. The lower wing 56b is formed in a substantially U-shape from the lower lateral wing 56c attached to the annular attachment portion 61 that is formed obliquely downward from the lower end of the wing 56b toward the inner shaft and the tip of the wing 56b is extrapolated to the inner head shaft portion 33. ing.
[0045]
In this example, the lower horizontal blade 56c, which is the lower end portion of the outer stirring blade 55, is formed wider than the other blades 56a, 56b, and the excavating blade 58 is formed on the lower end side. In this example, the excavating blade 58 is provided in the middle from the outer edge of the lower horizontal wing 56c to the attachment portion of the lower horizontal wing 56c, and is not provided near the center thereof.
[0046]
The annular mounting portion 61 is fitted with a sliding bearing 62 and is rotatably mounted on the outer periphery of the inner head shaft portion 33.
[0047]
Further, in this example, a central excavation blade 59 having a diameter smaller than that of the excavation blade 58 is attached to the lower end portion of the inner head shaft portion 33, and a curing agent discharge port 30 is formed at the lowermost end surface of the excavation blade 22. The discharge port 30 communicates with the inner hole of the central shaft 13 through the 0 passage 27. Further, a notch 39 is provided immediately below the inner shaft of the central excavation blade 59 so that the hardener from the discharge port 30 can flow out.
[0048]
[Operation and effect of the second embodiment]
The stirring head 50 according to the present example is used by being attached to the ground improvement device in the same manner as the stirring head of the first example, and the state of use in the ground improvement construction is the same as that of the first example.
In other words, the excavating shaft 10 is lowered while being rotated while pumping the hardener, and excavation of the ground, injection of the hardener into the excavated soil, and stirring and kneading are performed.
[0049]
In this example, in addition to the operation of the first embodiment described above, the agitating head 50 is provided with the excavating blade 58 at the lower end of the outer agitating blade 55, so that the excavating blade 58 has a large rotational torque. It will be driven by the outer shaft that is rotated by, and the ground can be excavated with a large excavation force.
[0050]
In this example, the central excavation blade 59 that rotates together with the inner shaft 12 is provided. Therefore, the central excavation blade 59 has a central portion where the excavation force tends to decrease among the excavation blades 58 below the outer stirring blade 55. The excavation can be performed, and the entire agitation head can have a good excavation force.
[0051]
Then, the excavating shaft 10 is added from above until reaching a predetermined depth, excavation stirring and kneading are performed, and after reaching the predetermined depth, the stirring head 50 is pulled out. At this time, when the excavating shaft is pulled out while being rotated, the excavated soil and the hardener are further stirred and kneaded. As the excavating shaft 10 is pulled out when the stirring head 50 is pulled out, the excavating shaft for relay is sequentially removed from above, and this operation is continued until the stirring head 50 appears on the ground surface.
[0052]
Therefore, in the stirring head 50 of the second example of the embodiment, in addition to the effects of the stirring head of the first example, the excavating blade 58 can be driven with a large rotational torque, and the ground can be excavated with a large excavating force. In addition, the central portion can be excavated by the central excavation blade 59, and the stirring head 50 as a whole can have a strong excavating force.
[0053]
【The invention's effect】
As described above, according to the agitation head of the ground improvement device of the present invention, the curing agent is injected from the injection nozzle into the excavated soil agitated at the lower part of the frame-shaped agitated blade of the outer agitated blade, and into the excavated soil. Hardener is mixed. At this time, the curing agent sprayed from the spray nozzle descends while rotating the penetration direction into the excavated soil, and draws a spiral in the excavated soil in the excavated hole. For this reason, the drilling flow of the hardener stirs the excavated soil with the flow force, and the hardener and the excavated soil are kneaded well.
[0054]
The excavated soil and the curing agent are further stirred and kneaded by the frame-shaped stirring blade and the protruding blade of the outer stirring blade of the inner stirring blade, and at this time, the radial stirring blade of the inner stirring blade and the outer stirring blade. Since the frame-shaped agitating blade and the projecting blade rotate in reverse so as to pass each other, complex shearing force is applied to the excavated soil mixed with the hardener, and the excavated soil and the hardener do not rotate together. Stir well.
[0055]
Further, in the stirring head of the present invention provided with a drilling blade at the lower end of the outer stirring blade, the drilling blade is driven with a large rotational torque, and can excavate the ground with a large drilling force. In the case where the central excavation blade that rotates together with the inner shaft is provided, the central portion can be excavated by the central excavation blade, and the entire agitation head can have an excellent excavation force.
[Brief description of the drawings]
FIG. 1 is a side view showing a first example of an embodiment of an agitation head according to the present invention.
2 is a cross-sectional view of the stirring head shown in FIG. 1 taken along line II-II in FIG.
3 is a cross-sectional view of the stirring head shown in FIG. 1 taken along line III-III in FIG.
FIG. 4 is a side view showing a second example of the embodiment of the stirring head according to the present invention.
5 is a cross-sectional view of the stirring head shown in FIG. 4 taken along line VV in FIG. 4;
6 is a cross-sectional view taken along the line VI-VI in FIG. 4 of the stirring head shown in FIG. 4;
7 is a cross-sectional view of the stirring head shown in FIG. 4 taken along line VII-VII in FIG.
FIG. 8 is a side view showing a ground improvement device using a stirring head according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Excavation shaft 11 Outer shaft 12 Inner shaft 20, 50 Stirring head 21, 51 Inner stirring blade 22, 52 Radiation stirring blade 23, 53 Injection nozzle 24, 54 Radiation stirring blade 25, 55 Outer stirring blade 26, 56 Frame-shaped stirring blade 27, 57 Projecting blade 28 Excavation blade 58 Excavation blade 59 Central excavation blade

Claims (2)

In an agitation head (20) which is attached to an excavation shaft (10) having an inner shaft (12) and an outer shaft (11) rotating in opposite directions and stirs and kneads excavated soil and hardener in the excavation hole. ,
The stirring head (20, 50) rotates with the inner shaft (12), the inner stirring blade (21, 51), and the outer shaft (11), and is disposed outside the inner stirring blade (21, 51). Consisting of outer stirring blades (25, 55),
The inner stirring blades (21, 51) are arranged in a plurality of stages by shifting a plurality of radial stirring blades (22, 52) arranged radially in the axial direction, and at least of the radiation stirring blades (22, 52). One radiation agitating blade (24, 54) is provided with an injection nozzle (23, 53) for ejecting a curing agent from its outer edge toward the direction of rotation, and the outer agitating blade (25, 55) A frame-like stirring blade (26, 56) whose rotation trajectory surrounds the rotation trajectory of the inner stirring blade (21, 51), and the stirring blade (22, 56) inward from the frame-shaped stirring blade (26, 56). 52) A stirrer head of a ground improvement device comprising projecting wings (27, 57) projecting so as to pass between the two.   The stirring head (50) includes a drilling blade (58) at the lower end of the outer stirring blade (55), and rotates with the inner shaft (12), and is drilled at the lower end of the outer stirring blade (55). The agitation head of the ground improvement device according to claim 1, wherein a center excavation blade (59) having a smaller diameter than the blade (58) is provided.

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