Ground improvement unit and ground improvement machine

Abstract

To provide a ground improvement unit and a ground improvement machine which can stabilize an excavation pipe when excavating the ground.SOLUTION: A ground improvement unit 3 includes: a tubular excavation pipe 8 which is vertically arranged, excavates a hole by lowering while rotating, and functions as a flow channel of a ground improvement material; a support / diameter enlarged piece 9 which is provided on the lower part of the excavation pipe 8 so as to be relatively rotatable with the excavation pipe 8 and extend radially outside of the excavation pipe 8; and a lock mechanism 10 for locking / unlocking the relative rotation of the excavation pipe 8 and the support / diameter enlarged piece 9.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a ground improvement unit and a ground improvement machine. [Background technology]

[0002] Patent Document 1 describes a ground improvement mixer (ground improvement machine) equipped with an expanding blade whose outer diameter expands or contracts depending on the rotation direction of the rotating shaft (drilling pipe). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-047642 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned ground improvement machine, the excavation pipe is supported only at its upper end, which may cause the excavation pipe to become unstable when excavating the ground.

[0005] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a ground improvement unit and a ground improvement machine that can stabilize an excavation pipe when excavating the ground. [Means for solving the problem]

[0006] (1) The present invention is a ground improvement unit (for example, ground improvement unit 3 described later) characterized by comprising: a tubular drilling pipe (for example, drilling pipe 8 described later) that is arranged vertically, drills holes by rotating and descending, and functions as a flow path for ground improvement material; a support / expansion piece (for example, support / expansion piece 9 described later) that is attached to the lower part of the drilling pipe so as to be rotatable relative to the drilling pipe and extend radially outward from the drilling pipe; and a locking mechanism (for example, locking mechanism 10 described later) that locks and releases the relative rotation of the drilling pipe and the support / expansion piece.

[0007] According to the present invention, the drilling pipe is lowered while rotating with the locking mechanism released, and the support and diameter expansion pieces are lowered together with the drilling pipe while piercing the ground. As a result, the support and diameter expansion pieces piercing the ground support the drilling pipe, making it possible to stabilize the drilling pipe during drilling.

[0008] Furthermore, according to the present invention, when the drilling pipe rotates while locked by the locking mechanism, the support and expansion piece rotates together with the drilling pipe. As a result, it is possible to excavate a hole with a diameter larger than the diameter of the hole that has just been excavated by rotating the drilling pipe alone. For example, when the drilling pipe is lowered while rotating while unlocked by the locking mechanism, a pile with an expanded bottom can be constructed by rotating the drilling pipe while locked by the locking mechanism.

[0009] (2) The present invention also provides the ground improvement unit described in (1) above, characterized in that the locking mechanism has a rod (e.g., rod 10a described later) that is arranged outside the drilling pipe, parallel to the drilling pipe, and capable of moving forward and backward toward the support / expansion piece, and that locks by moving toward the support / expansion piece and engaging with a fitting portion in the support / expansion piece (e.g., fitting portion 9c described later), and that releases the lock by escaping from the fitting portion.

[0010] (3) The present invention also provides a ground improvement unit as described in (2) above, characterized in that the locking mechanism has a hydraulic cylinder (e.g., hydraulic cylinder 10b described later) that is placed on the ground and moves the rod forward and backward toward the support / expansion piece.

[0011] (4) The present invention also relates to a ground improvement machine (e.g., the ground improvement machine 1 described later) comprising a ground improvement unit described in any one of (1) to (3) above and a base machine (e.g., the base machine 2 described later) to which the ground improvement unit is attached. [Effects of the Invention]

[0012] According to the ground improvement unit according to the above (1) to (3) and the ground improvement machine according to the above (4) of the present invention, it is possible to stabilize the excavation pipe when excavating the ground. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a side view of a ground improvement machine according to an embodiment of the present invention, showing the ground improvement unit standing upright. [Figure 2] 2 is a side view of the support and expansion pieces and locking mechanism in the ground improvement machine of FIG. 1, showing the state in which the lock on the relative rotation between the drill pipe and the support and expansion pieces has been released. [Figure 3] 2 is a side view of the support and expansion pieces and locking mechanism in the ground improvement machine of FIG. 1, showing the state in which the relative rotation of the drill pipe and the support and expansion pieces is locked. DETAILED DESCRIPTION OF THE INVENTION

[0014] Below, a soil improvement machine according to an embodiment of the present invention will be described in detail with reference to the drawings. In the drawings, the arrow FR indicates the front of the soil improvement machine, and the arrow UR indicates the upward direction. In the following description, the front-to-back direction means the front-to-back direction of the soil improvement machine, and the left-to-right direction means the left-to-right direction when facing the front of the soil improvement machine. In each drawing, some components are omitted as appropriate to simplify the drawing.

[0015] First, the configuration of the ground improvement machine 1 will be described using Figures 1 to 3. Figure 1 is a side view of the ground improvement machine 1, showing the ground improvement unit 3 in an upright position. Figure 2 is a side view of the support and expansion pieces 9 and locking mechanism 10 in the ground improvement machine 1, showing the state in which the lock on the relative rotation between the drilling pipe 8 and the support and expansion pieces 9 has been released. Figure 3 is a side view of the support and expansion pieces 9 and locking mechanism 10 in the ground improvement machine 1, showing the state in which the lock on the relative rotation between the drilling pipe 8 and the support and expansion pieces 9 has been locked.

[0016] The ground improvement machine 1 shown in Figures 1 and 2 is a construction machine, such as a pile driver, used for the enlarged-bottom soil cement column method (enlarged-bottom columnar improvement method) and the enlarged-bottom steel pipe soil cement pile method.

[0017] The enlarged-bottom soil cement column method involves drilling a hole in the ground in the shape of a column, injecting a ground improvement material (such as cement milk) made by mixing a cement-based solidification material with water to form a slurry, and mixing the ground improvement material with the excavated soil to create a chemically solidified enlarged-bottom soil cement column.

[0018] The expanded-bottom steel pipe soil cement pile method is a method that combines the expanded-bottom soil cement column method with steel pipe piles, in which steel pipe piles are buried in the core of soil cement before it has been chemically solidified.

[0019] Specifically, the soil improvement machine 1 includes a self-propelled base machine 2 and a soil improvement unit 3 attached to the base machine 2.

[0020] The ground improvement unit 3 is what is called the front in the civil engineering industry, and is attached so as to be able to be raised and lowered at the front of the base machine 2. Specifically, the ground improvement unit 3 comprises a leader 5, a rail 6, a swivel joint 7, an excavation pipe 8, a support / expansion piece 9, and a locking mechanism 10. For the sake of simplicity, the following description will be given on the assumption that the ground improvement unit 3 is in an upright position.

[0021] The leader 5 is made up of a square piece of lumber (square pipe) having a predetermined length, and is provided vertically in front of the base machine 2 and behind the excavation pipe 7.

[0022] A rail 6 that enables the swivel joint 7 to be raised and lowered is provided on the front surface of the leader 5 from the bottom to the top end so as to be parallel to the drill pipe 8. The leader 5 and the rail 6 may be formed integrally or separately.

[0023] The swivel joint 7 supports the drill pipe 8 so that it can be raised and lowered and rotated. Specifically, the swivel joint 7 has an upper joint 7a and a lower joint 7b. The upper joint 7a is provided so that it can be raised and lowered along the rail 6, and rises and falls along the rail 6 with a predetermined stroke. This swivel joint 7 incorporates a rotation mechanism (not shown). The rotation mechanism is composed of a motor (not shown) and the like, and rotates the lower joint 7b relative to the upper joint 7a.

[0024] The upper end of the drilling pipe 8 is fixed to the lower joint part 7b, and a hydraulic cylinder 10b of the locking mechanism 10 is also fixed to the lower joint part 7b. The tip of a hose (not shown) that supplies ground improvement material is connected to the side or top of the swivel joint 7. In other words, the swivel joint 7 functions as a swivel joint that connects the tip of the hose to the opening (not shown) at the upper end of the rotating drilling pipe 8.

[0025] The drilling pipe 8 is tubular and serves as a flow path for the soil improvement material. It is vertically mounted on the leader 5 and can be raised and lowered. The drilling pipe 8 excavates a hole by rotating around its axis and descending. A pair of upper and lower guide rings 8a, 8b that guide the support / expansion piece 9 are fixed to the lower part of the drilling pipe 8. The upper guide ring 8a has a notch (reference number omitted) formed therein for passing the rod 10a of the locking mechanism 10. The lower end of the drilling pipe 8 is fitted with a drilling claw 8c that excavates a hole into which the soil improvement material is injected. The upper joint lower part 7b of the swivel joint 7 is fixed to the upper end of the drilling pipe 8. The upper end of the drilling pipe 8 forms an inlet (not shown) for introducing the soil improvement material. The interior of the drilling pipe 8 forms a flow path for the soil improvement material supplied from a hose (not shown). The lower end of the drilling pipe 8 forms an outlet (not shown) for discharging the soil improvement material. On the outer periphery of drill pipe 8, a member (not shown) for guiding rod 10a in lock mechanism 10, for example a ring welded to drill pipe 8, is appropriately provided.

[0026] The support / diameter expansion piece 9 is provided at the lower part of the drill pipe 8 so as to be rotatable relative to the drill pipe 8 around the drill pipe 8 as its axis and to extend radially outward from the drill pipe 8. Specifically, the support / diameter expansion piece 9 has a rotatable ring 9a and a pair of piece bodies 9b. The rotatable ring 9a is disposed between the pair of guide rings 8a, 8b so as to be rotatable relative to the drill pipe 8 around the drill pipe 8 as its axis. A fitting portion 9c into which a rod 10a of the locking mechanism 10 fits is formed above this rotatable ring 9a. The piece body 9b is configured integrally with the rotatable ring 9a and extends radially outward from the rotatable ring 9a.

[0027] The locking mechanism 10 locks and unlocks the relative rotation between the drilling pipe 8 and the support / expansion piece 9. Specifically, the locking mechanism 10 has a rod 10a and a hydraulic cylinder 10b. The rod 10a is arranged outside the drilling pipe 8, parallel to the drilling pipe 8, and movable toward and away from the support / expansion piece 9. The rod 10a advances toward the support / expansion piece 9 and fits into a fitting portion 9c in the support / expansion piece 9, thereby locking the relative rotation between the drilling pipe 8 and the support / expansion piece 9 and causing the support / expansion piece 9 to function as an expansion piece. The rod 10a is released by escaping from the fitting portion 9c, causing the support / expansion piece 9 to function as a support piece. The hydraulic cylinder 10b is arranged on the ground and moves the rod 10a forward and backward toward the support / expansion piece 9.

[0028] Next, the movements of the soil improvement machine 1 and the soil improvement unit 3 will be described with reference to FIGS.

[0029] First, with the locking mechanism 10 released, the drilling pipe 8 is rotated and lowered to drill a hole in the ground. At this time, the support and expansion piece 9 penetrates the ground and descends together with the drilling pipe 8. Although the support and expansion piece 9 penetrates the ground, this has no effect on the ground improvement.

[0030] Thereafter, the drill pipe 8 is rotated in a state locked by the locking mechanism 10. At this time, the support / diameter expansion piece 9 rotates together with the drill pipe 8.

[0031] Thereafter, while the excavation pipe 8 and the support / expansion piece 9 are being rotated, a required amount of soil improvement material is injected and mixed with the excavated soil.

[0032] Thereafter, the rotation of the drilling pipe 8 and the support and expansion pieces 9 is stopped, and the drilling pipe 8 is raised and pulled out of the ground. At this time, the support and expansion pieces 9 are pulled out of the ground by rising together with the drilling pipe 8 while piercing the ground. Although the support and expansion pieces 9 pierce the ground, this has no effect on the ground improvement.

[0033] In this way, with the ground improvement machine 1 and the ground improvement unit 3, the drilling pipe 8 rotates and descends while the locking mechanism 10 is released, and the support and diameter expansion pieces 9 penetrate the ground and descend together with the drilling pipe 8. As a result, the support and diameter expansion pieces 9 that have penetrated the ground support the drilling pipe 8, making it possible to stabilize the drilling pipe 8 when excavating the ground.

[0034] Furthermore, with the ground improvement machine 1 and the ground improvement unit 3, when the drilling pipe 8 rotates while locked by the locking mechanism 10, the support and expansion piece 9 rotates together with the drilling pipe 8. As a result, it is possible to excavate a hole with a diameter larger than the diameter of the hole that has just been excavated by rotating the drilling pipe 8 alone. For example, after the drilling pipe 8 is released from the lock by the locking mechanism 10 and is lowered while rotating, the drilling pipe 8 rotates while locked by the locking mechanism 10, thereby constructing a pile with an expanded diameter at the bottom.

[0035] The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the spirit and technical concept of the present invention. In other words, the position, size, length, number, shape, material, etc. of each component can be changed as appropriate.

[0036] That is, in the above embodiment, the locking mechanism 10 has been described as an example of a mechanism for locking and unlocking the relative rotation between the drilling pipe 8 and the support and expansion piece 9, but the present invention is not limited to this, and a ratchet mechanism, for example, may be employed. If a ratchet mechanism is employed, the ratchet mechanism will unlock the relative rotation between the drilling pipe 8 and the support and expansion piece 9 when the drilling pipe 8 is rotated in one direction, and will lock the relative rotation between the drilling pipe 8 and the support and expansion piece 9 when the drilling pipe 9 is rotated in the other direction. [Explanation of symbols]

[0037] 1 Ground improvement machine 2 Base Machine 3 Ground improvement unit 5 Leader 6 Rail 7 Swivel joint 7a Upper joint 7b Lower joint 8 Drilling Pipe 8a, 8b Guide ring 8c digging claw 9 Support / expansion piece 9a Rotating Ring 9b Single body 9c Mating part 10 Locking mechanism 10a rod 10b Hydraulic cylinder

Claims

1. A tubular drilling pipe that is arranged vertically and rotates while descending to excavate a hole and also functions as a flow path for the ground improvement material; A support / expansion piece is provided at a lower part of the drilling pipe so as to be rotatable relative to the drilling pipe and to extend radially outward from the drilling pipe; and a locking mechanism for locking and unlocking the relative rotation of the drilling pipe and the support / expansion piece. Ground improvement unit.

2. The locking mechanism is a rod that is arranged outside the drilling pipe in parallel with the drilling pipe and that can advance and retreat toward the support / diameter expansion piece, that advances toward the support / diameter expansion piece and fits into a fitting portion of the support / diameter expansion piece to perform the locking, and that escapes from the fitting portion to perform the release. The ground improvement unit according to claim 1.

3. The locking mechanism is a hydraulic cylinder disposed on the ground and adapted to move the rod forward and backward toward the support and diameter expansion piece; The ground improvement unit according to claim 2.

4. The ground improvement unit according to any one of claims 1 to 3, a base machine to which the ground improvement unit is attached; Ground improvement machine.

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