Drilling equipment

Abstract

To provide an excavation device that can perform the operation of discharging soil from the hole to the surface while eliminating the compaction caused by excavated soil by rotating only in the forward direction. [Solution] In a drilling device in which a drilling head is provided at the lower end of the auger, and an expanding wing is provided on the drilling head that can be displaced between an outwardly open expanded position and a contracted position that is more contracted than the expanded position, the expanding wing is maintained in the contracted position when the auger rotates forward, and the expanding wing is displaced from the contracted position to the expanded position when the auger rotates backward, the device has an injection liquid supply channel 30 formed in the rotating rod 11 of the drilling head to which injection liquid is supplied, a tip discharge port 31 formed at the tip of the drilling head and communicating with the injection liquid supply channel 30, a plurality of injection nozzles 32 formed on the side surface of the rotating rod 11 and communicating with the injection liquid supply channel 30, and an opening / closing mechanism 40 that limits the opening degree of the tip discharge port 31 when the auger rotates forward.

Description

Technical Field

[0001] The present invention relates to an excavation device provided with an expansion wing.

Background Art

[0002] As an excavation device for enlarging the tip of a pile hole formed in the ground to form an anchoring portion, for example, there is an enlarged excavation device described in Patent Document 1. The enlarged excavation device described in Patent Document 1 is used by being connected to the tip of an excavation rod so as to rotate integrally with the excavation rod. This enlarged excavation device includes a hollow drive shaft communicating with the excavation rod, two excavation wings having a spiral shape provided on the outer periphery thereof, an excavation blade attached to the tip of each excavation wing, and two expansion wings provided along the spiral of each excavation wing and configured to be switchable between a diameter-expanded state and a diameter-reduced state.

[0003] The two expansion wings are swingably supported by pins on brackets connected to the excavation wings. In this enlarged excavation device, during pile hole excavation in which the excavation rod is rotated forward, due to the earth pressure, it enters a diameter-reduced state in which most of it is accommodated within the rotation locus of the excavation wings, and by rotating the excavation rod reversely, the expansion wings receive the earth pressure and swing around the pins, and are configured to enter a diameter-expanded state protruding radially outward from the rotation locus of the excavation wings.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When drilling a borehole using a drilling machine, the drilling head, which is rotating in the forward direction, is repeatedly moved up and down to discharge the soil from the borehole to the surface. At this time, a phenomenon may occur where soil and sediment accumulate in clumps on the side of the rotating rod at the tip of the head. When soil and sediment accumulate in clumps at the tip of the head in this way, the entire tip of the head becomes compacted, and the drilling performance is significantly reduced.

[0006] To avoid this consolidation, it is effective to reverse the rotation of the head tip. However, conventional drilling devices have a mechanism where reversing the rotation causes the expanding blades to expand and perform enlarged drilling, so it is not possible to eliminate the consolidation without performing enlarged drilling.

[0007] Therefore, the objective of the present invention is to provide an excavation device that can discharge the soil in the hole to the surface while eliminating the compaction caused by the excavated soil by rotating only in the forward direction. [Means for solving the problem]

[0008] The drilling apparatus of the present invention is provided with a drilling head at the lower end of an auger, and the drilling head is provided with an expanding wing that can be displaced between an outwardly open expanded position and a contracted position that is more contracted than the expanded position, the expanding wing is maintained in the contracted position when the auger rotates forward, and the expanding wing is displaced from the contracted position to the expanded position when the auger rotates backward, the drilling apparatus having an injection liquid supply channel formed in the rotating rod of the drilling head to which injection liquid is supplied, a tip discharge port formed at the tip of the drilling head and communicating with the injection liquid supply channel, a plurality of injection nozzles formed on the side surface of the rotating rod and communicating with the injection liquid supply channel, and an opening and closing mechanism that limits the opening degree of the tip discharge port when the auger rotates forward or backward.

[0009] In the drilling apparatus of the present invention, injection fluid is supplied to a tip discharge port formed at the tip of the drilling head and to a plurality of injection nozzles formed on the side of the rotating rod via an injection fluid supply channel. During normal drilling when the auger is rotating in the forward direction, injection fluid such as drilling fluid and stabilizing fluid is supplied from the injection fluid supply channel. When the opening of the tip discharge port is limited by an opening and closing mechanism during forward rotation of the auger, the amount of injection fluid discharged from this tip discharge port to the tip of the drilling head is limited, and this limited amount is distributed more to the plurality of injection nozzles and injected from the side of the rotating rod.

[0010] On the other hand, during reversing the auger's rotation for expanded excavation, injection fluids such as root consolidation fluid and pile-surrounding fixing fluid are supplied through the injection fluid supply channel. Since the opening of the tip discharge port is not restricted when the auger is rotating in reverse, most of the injection fluids such as root consolidation fluid and pile-surrounding fixing fluid are discharged from the tip discharge port to the tip of the excavation head, so that the construction of the root consolidation section and the pile-surrounding surface section is carried out using the same mixing method as in conventional construction.

[0011] Furthermore, if the opening of the tip discharge port is restricted by the opening / closing mechanism when the auger is rotating in the reverse direction, the opening of the tip discharge port is not restricted when the auger is rotating in the forward direction. As a result, most of the injection fluid discharged from the tip discharge port to the tip of the drilling head will be discharged from the tip discharge port to the tip of the drilling head.

[0012] The opening and closing mechanism is preferably designed to close at least a portion of the tip discharge port due to the earth pressure received when the auger is rotating forward or backward, and to open the tip discharge port due to the earth pressure received when the auger is rotating backward or forward. This makes it possible to automatically close or open at least a portion of the tip discharge port depending on whether the auger is rotating forward or backward. [Effects of the Invention]

[0013] (1) With a configuration that includes an injection fluid supply channel formed within the rotating rod of the drilling head for supplying injection fluid, a tip discharge port formed at the tip of the drilling head and communicating with the injection fluid supply channel, a plurality of injection nozzles formed on the side of the rotating rod and communicating with the injection fluid supply channel, and an opening / closing mechanism that limits the opening of the tip discharge port when the auger is rotating forward, the amount of injection fluid discharged from the tip discharge port to the tip of the drilling head is limited by the opening / closing mechanism when the auger is rotating forward, and this limited amount is distributed to the plurality of injection nozzles and injected from the side of the rotating rod, so that injection fluids such as drilling fluid and stabilizing fluid are discharged and injected in a balanced manner from the tip discharge port and the side of the rotating rod, compacted soil can be removed, and the work of drilling and discharging soil from the hole to the surface can be performed while eliminating the compacted state with forward rotation alone.

[0014] (2) With a configuration that includes an injection liquid supply channel formed in the rotating rod of the drilling head for supplying injection liquid, a tip discharge port formed at the tip of the drilling head and communicating with the injection liquid supply channel, a plurality of injection nozzles formed on the side of the rotating rod and communicating with the injection liquid supply channel, and an opening / closing mechanism that limits the opening of the tip discharge port when the auger is rotating in the reverse direction, the opening of the tip discharge port is not limited when the auger is rotating in the forward direction, so most of the injection liquid discharged from the tip discharge port to the tip of the drilling head is discharged from the tip discharge port to the tip of the drilling head, so when the ground is hard or when it is desired to accelerate the removal of sandy soil, it is possible to discharge a large amount of water from the tip discharge port when rotating in the forward direction.

[0015] (3) The opening and closing mechanism closes at least a portion of the tip discharge port due to the earth pressure received when the auger rotates forward, and opens the tip discharge port due to the earth pressure received when the auger rotates backward. This allows the auger to automatically close or open at least a portion of the tip discharge port when it rotates forward or backward, enabling excavation and discharge of soil from the hole to the surface while eliminating the compacted state with injection fluid such as drilling fluid or stabilizing fluid when rotating forward, and enabling the construction of the foundation and pile surface by injecting injection fluid with a high specific gravity, such as foundation reinforcement fluid or pile perimeter fixing fluid, from the tip discharge port when rotating backward.

[0016] (4) The opening and closing mechanism closes at least a part of the tip discharge port due to the earth pressure received during the reverse rotation of the auger, while opening the tip discharge port due to the earth pressure received during the forward rotation of the auger. Thus, at least a part of the tip discharge port is automatically closed or opened by the forward or reverse rotation of the auger, and when the ground is hard or when it is desired to promote the discharge of sandy soil, etc., it becomes possible to discharge a large amount of water from the tip discharge port during forward rotation.

Brief Description of the Drawings

[0017] [Figure 1] It is a front view of the lower element of the auger of the excavation device in the embodiment of the present invention. [Figure 2] It is a bottom view of FIG. 1. [Figure 3] It is a cross-sectional view of the rotating rod of FIG. 1. [Figure 4] It is a bottom perspective view of FIG. 1, where (a) is a view showing the state during forward rotation and (b) is a view showing the state during reverse rotation. [Figure 5] It is an explanatory view showing another example of the cover. [Figure 6] It is an explanatory view showing still another example of the cover. [Figure 7] It is an explanatory view showing from the excavation process to the construction process of the root reinforcement part.

Embodiments for Carrying Out the Invention

[0018] FIG. 1 is a front view of the lower element of the auger of the excavation device in the embodiment of the present invention, FIG. 2 is a bottom view of FIG. 1, FIG. 3 is a cross-sectional view of the rotating rod of FIG. 1, and FIG. 4 is a bottom perspective view of FIG. 1, where (a) is a view showing the state during forward rotation and (b) is a view showing the state during reverse rotation.

[0019] The auger of the excavation device in this embodiment is composed of a plurality of elements. The lower element 1 shown in Fig. 1 is attached to the bottom side of the auger. The lower element 1 is provided with an excavation head 2 at its lower end. The excavation head 2 is provided with a large-diameter expansion wing 3 and a small-diameter expansion wing 4 as expansion wings that displace between an expanded position open to the outside and a reduced position that is more contracted than this expanded position. The small-diameter expansion wing 4 is provided above the large-diameter expansion wing 3. A connection part 6 for connecting to the upper element is provided at the upper end part of the lower element 1.

[0020] During the normal rotation of the auger, the large-diameter expansion wing 3 and the small-diameter expansion wing 4 are maintained in the reduced position, and during the reverse rotation of the auger, the large-diameter expansion wing 3 and the small-diameter expansion wing 4 are displaced from the reduced position to the expanded position. In Figs. 1 and 2, all the expansion wings are in the expanded position. As shown in Fig. 2, the large-diameter expansion wing 3 is configured such that the diameter for expanded excavation is larger than that of the small-diameter expansion wing 4.

[0021] The large-diameter expansion wing 3 is attached to the rotation rod 11 of the excavation head 2 so as to be swingable about a swing axis 12. An excavation claw 13 is provided on the lower side of the tip of this large-diameter expansion wing 3. Further, the large-diameter expansion wing 3 is provided with a curved protruding part 14. When the large-diameter expansion wing 3 is in the reduced position, this protruding part 14 protrudes in a direction away from the rotation axis of the rotation rod 11. And the tip of the large-diameter expansion wing 3 has a shorter distance from the rotation axis than the distance from the rotation axis of the protruding part 14.

[0022] The small-diameter expansion wing 4 located above the large-diameter expansion wing 3 is attached to the rotation rod 11 so as to be swingable about a swing axis 22. Excavation claws 23 are provided on the upper side and the lower side of the tip of this small-diameter expansion wing 4.

[0023] As shown in Figure 3, an injection fluid supply channel 30 is formed inside the rotating rod 11 of the drilling head 2, through which injection fluids such as drilling fluid, stabilizing fluid, root consolidation fluid, and pile perimeter fixing fluid are supplied. A tip discharge port 31 is formed at the tip of the rotating rod 11, which communicates with the injection fluid supply channel 30. Multiple injection nozzles 32 are formed on the side of the rotating rod 11, which communicate with the injection fluid supply channel 30. In addition, an opening / closing mechanism 40 is provided at the tip of the rotating rod 11 to limit the opening degree of the tip discharge port 31 when the auger is rotating in the forward direction.

[0024] As shown in Figures 3 and 4, the opening and closing mechanism 40 has a cover 41 that covers the tip discharge port 31. The cover 41 is attached to a swing arm 43 that can swing around a swing shaft 42. The tip of the swing arm 43 opposite to the swing shaft 42 is provided with a claw portion 45 that fits into and slides in a fan-shaped groove portion 44 formed on the tip of the rotating rod 11. The swing arm 43 can swing between the state shown in Figure 4(a) and the state shown in Figure 4(b) by the sliding of the claw portion 45 within the groove portion 44.

[0025] As shown in Figure 4(a), when the auger rotates forward, the cover 41 and the oscillating arm 43 rotate in the opposite direction to the auger's rotation due to the earth pressure. As a result, the cover 41 closes off a portion of the tip discharge port 31, leaving only a portion of the tip discharge port 31 open. On the other hand, as shown in Figure 4(b), when the auger rotates backward, the cover 41 and the oscillating arm 43 rotate in the opposite direction to the auger's rotation due to the earth pressure. As a result, the cover 41 opens the tip discharge port 31, leaving the entire tip discharge port 31 open.

[0026] Furthermore, the oscillating arm 43 is provided with an opening 43A for adjusting the earth pressure on the oscillating arm 43 when the auger rotates. By adjusting the size of this opening 43A, the earth pressure on the oscillating arm 43 when the auger rotates can be reduced. In addition, by adjusting the size of the fan-shaped groove 44, the opening degree of the tip discharge port 31 can be adjusted.

[0027] The opening of the tip discharge port 31 can also be adjusted by changing the shape and size of the cover 41. Figure 5 is an explanatory diagram showing another example of the cover. The cover 51 shown in Figure 5 is smaller than the cover 41. The shape and size of the cover 51 are such that it does not completely block the tip discharge port 31 when the auger is rotating in the forward and reverse directions.

[0028] As shown in Figure 5(a), when the auger rotates forward, the cover 51 and the oscillating arm 43 are subjected to earth pressure F and rotate in the opposite direction to the auger's rotation. As a result, the cover 51 closes a portion of the tip discharge port 31, leaving only a portion of the tip discharge port 31 open (the portion shown as a shaded area in the figure is open). On the other hand, as shown in Figure 5(b), when the auger rotates backward, the cover 51 and the oscillating arm 43 are subjected to earth pressure R and rotate in the opposite direction to the auger's rotation. As a result, the cover 51 opens the tip discharge port 31, leaving the entire tip discharge port 31 open (the portion shown as a shaded area in the figure is open).

[0029] Figure 6 is an explanatory diagram illustrating yet another example of the cover. The cover 61 shown in Figure 6 is larger than the cover 41. As shown in Figure 6(a), the cover 61 is shaped and sized to completely close the tip discharge port 31 when the auger is rotating in the forward direction. For this reason, the cover 61 has an opening 62, so that even when the cover 61 completely closes the tip discharge port 31, a part of the tip discharge port 31 remains open due to the opening 62.

[0030] Next, the formation of the foundation reinforcement section using the excavation device with the above configuration will be explained with reference to Figure 7. Figure 7 is an explanatory diagram showing the process from the excavation process to the foundation reinforcement section construction process.

[0031] <Excavation Process> In the excavation process, the auger and drilling head 2 are rotated forward (counterclockwise in Figure 2) to excavate downwards. During normal excavation with the auger rotating forward, drilling fluid is supplied as injection fluid from the injection fluid supply channel 30. When the auger rotates forward, the opening of the tip discharge port 31 is restricted by the opening / closing mechanism 40, so the amount of drilling fluid discharged from this tip discharge port 31 to the tip of the drilling head 2 is restricted, and this restricted amount is distributed to multiple injection nozzles 32 and injected from the side of the rotating rod 11. As a result, compacted soil can be removed by discharging and injecting drilling fluid in a balanced manner from the tip discharge port 31 and the side of the rotating rod 11, and the excavation work can be performed while eliminating the compacted state by repeatedly moving the auger and drilling head 2 up and down with only forward rotation.

[0032] Furthermore, in order to prevent the collapse of the borehole wall, when the work of discharging the soil from the borehole to the surface is performed, a stabilizing fluid is supplied as the injection fluid through the injection fluid supply channel 30, and the auger is rotated in the forward direction. As described above, when the auger is rotating in the forward direction, the opening degree of the tip discharge port 31 is limited by the opening / closing mechanism 40, so the amount of stabilizing fluid discharged from this tip discharge port 31 to the tip of the drilling head 2 is limited, and this limited amount is distributed in large quantities to multiple injection nozzles 32 and injected from the side of the rotating rod 11. As a result, the stabilizing fluid can be discharged and injected in a balanced manner from the tip discharge port 31 and the side of the rotating rod 11, and the work of discharging the soil from the borehole to the surface can be performed by repeatedly moving the auger and drilling head 2 up and down with only forward rotation.

[0033] <Pile peripheral construction process> Once downward excavation is complete, the auger is reversed and pulled upward. This causes the small-diameter expanding blade 4 and the large-diameter expanding blade 3 to sequentially displace to their expanded positions, resulting in expanded excavation. During this expanded excavation with the auger reversed, pile-surrounding fixing fluid is supplied as the injection fluid from the injection fluid supply channel 30. When the auger is reversed, the opening of the tip discharge port 31 is not restricted by the opening / closing mechanism 40, so most of the pile-surrounding fixing fluid is discharged from the tip discharge port 31 to the tip of the excavation head 2. As a result, the pile-surrounding fixing fluid, which has a high specific gravity, is discharged from the tip discharge port 31 to the tip of the excavation head 2, so that the construction of the pile surface is carried out using the same mixing method as in conventional construction.

[0034] <Construction process for the foundation reinforcement section> Next, in the construction process of the foundation reinforcement section, the foundation reinforcement liquid is supplied as the injection liquid through the injection liquid supply channel 30, and the auger is rotated in reverse. As mentioned above, when the auger rotates in reverse, the opening degree of the tip discharge port 31 is not restricted by the opening / closing mechanism 40, so most of the foundation reinforcement liquid is discharged from the tip discharge port 31 to the tip of the drilling head 2. As a result, the foundation reinforcement liquid, which has a high specific gravity, is discharged from the tip discharge port 31 to the tip of the drilling head 2, which is advantageous for the construction of the foundation reinforcement section.

[0035] In the above embodiment, an example was described in which the opening degree of the tip discharge port 31 is restricted by the opening / closing mechanism 40 when the auger is rotating in the forward direction. However, conversely, the opening degree of the tip discharge port can be restricted by the opening / closing mechanism when the auger is rotating in the reverse direction. In this case, the opening degree of the tip discharge port is not restricted when the auger is rotating in the forward direction, so most of the injection liquid discharged from the tip discharge port to the tip of the drilling head is discharged from the tip discharge port to the tip of the drilling head. Therefore, when the ground is hard or when it is desired to accelerate the removal of sandy soil, it becomes possible to discharge a large amount of water from the tip discharge port when the auger is rotating in the forward direction. [Industrial applicability]

[0036] The excavation device of the present invention is useful as an excavation device that enlarges and excavates the tip of a pile hole formed in the ground to form a foundation reinforcement section. [Explanation of Symbols]

[0037] 1 Lower element 2 drilling heads 3. Large diameter enlarged wings 4. Small diameter enlarged wings 6. Connection part 11 Rotating Rods 12. Pivot axis 13 Excavation claws 14 Protrusion 22. Oscillating axis 23 Excavation claws 30 Injection fluid supply channel 31 Tip outlet 32 spray nozzles 40 Opening and closing mechanism 41, 51, 61 Cover 42. Oscillating axis 43. Swivel Arm 44 grooves 45 Claw part 62 Opening part

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