Construction method of bottom-enlarged bucket and bottom-enlarged hole

Abstract

To provide a large-sized bottom enlarged bucket and a bottom enlarged hole construction method, which can reduce weight of the bottom enlarged bucket and suppress increase of excavation resistance.SOLUTION: A first bucket body 22 has a first bottom enlarged bucket 21, which has an upper bottom enlarged blade 24 to construct an upper side of a bottom enlarged hole 42. A second bucket body 32 has a second bottom enlarged bucket 31, which has a lower bottom enlarged blade 34 to construct a lower side of the bottom enlarged hole 42. The first bottom enlarged bucket 21 and the second bottom enlarged bucket 31 are replaceably fitted to a tip of a kelly-bar.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a bottom-expanding bucket and a bottom-expanding hole construction method for enlarging and excavating the bottom of a vertical hole excavated by an earth drill to form a bottom-expanding hole. [Background technology]

[0002] Conventionally, when drilling a bottom-reaming hole using an earth drill, a digging bucket is first attached to the tip of a kelly bar to excavate a vertical hole of a predetermined depth. The digging bucket is then replaced with a bottom-reaming bucket to ream the bottom of the vertical hole into a tapered (conical) shape. This bottom-reaming bucket has bottom-reaming wings with excavation blades that open and close by operating a hydraulic cylinder on the outer periphery of the bucket body. The hydraulic cylinder expands and contracts with hydraulic pressure supplied to the hydraulic cylinder from a base machine, opening and closing the bottom-reaming wings. Foundation piles for high-rise buildings and towers, for example, require high bearing capacity, so drilling a large-diameter bottom-reaming hole is required to increase the diameter of the foundation pile. However, drilling a large-diameter bottom-reaming hole requires larger bottom-reaming wings, which increases excavation resistance and the weight of the bottom-reaming bucket, reducing the amount of soil that can be removed at one time.

[0003] For this reason, the flared wings of the flared bucket are divided into two sections, upper and lower, with the lower flared wings being the driving flared wings and the upper flared wings being the driven flared wings, and a power transmission means for linking them is provided between the two, so that the lower flared wings open to a certain extent before the upper flared wings open, allowing the flared wings to close well when closing without having to increase the size of the bucket body (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-213270 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above-mentioned Patent Document 1, although the bucket body can be prevented from becoming larger and heavier by dividing the base flare into two sections, upper and lower, the effect is limited, and the increase in excavation resistance cannot be prevented.

[0006] Therefore, the present invention aims to provide a large-sized expanded bottom bucket and a method for constructing an expanded bottom hole that can reduce the weight of the expanded bottom bucket and suppress an increase in excavation resistance. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the bottom-expanding bucket of the present invention is a bottom-expanding bucket that is removably attached to the tip of the kelly bar of an earth drill, and enlarges and excavates the bottom of a previously excavated vertical hole by opening the bottom-expanding wings that are attached to the bucket body in an openable and closable manner, thereby forming an enlarged bottom hole.In this bottom-expanding bucket, the bottom-expanding wings are formed by dividing them into an upper bottom-expanding wing that works the upper side of the enlarged bottom hole and a lower bottom-expanding wing that works the lower side of the enlarged bottom hole, and the bottom-expanding bucket comprises a first bottom-expanding bucket and a second bottom-expanding bucket that are removably attached to the tip of the kelly bar, and the first bottom-expanding bucket has only the upper bottom-expanding wing on the first bucket body, and the second bottom-expanding bucket has only the lower bottom-expanding wing on the second bucket body.

[0008] In addition, the method for constructing a reamed bottom hole of the present invention is characterized in that, in a method for constructing a reamed bottom hole using the reamed bottom bucket described in claim 1, the first reamed bottom bucket is attached to the tip of the kelly bar, the upper side of the reamed bottom hole is constructed, the first reamed bottom bucket is lifted up, the first reamed bottom bucket is removed from the tip of the kelly bar on the ground and replaced with the second reamed bottom bucket, and the lower side of the reamed bottom hole is constructed. [Effects of the Invention]

[0009] According to the bottom-expanding bucket and bottom-expanding hole construction method of the present invention, two types of bottom-expanding buckets, consisting of a first bottom-expanding bucket and a second bottom-expanding bucket, are attached to the tip of the kelly bar in sequence for each excavation stage, and are used to construct a bottom-expanding hole while minimizing the excavation resistance generated by the bottom-expanding bucket. Furthermore, because the first bottom-expanding bucket and the second bottom-expanding bucket only have either an upper bottom-expanding wing or a lower bottom-expanding wing, the weight of the bottom-expanding bucket can be reduced, increasing the amount of soil that can be discharged at one time, reducing the number of times the work is carried out, and improving efficiency.

[0010] In addition, because excavation can be divided between the top and bottom (excavation can be divided between the top and bottom of the expanded wing only) excavation resistance can be minimized compared to excavating the top and bottom together as a single unit. Furthermore, since the total weight of the expanded bucket and soil weight is determined by the capacity of the excavator, by using expanded wings only on the top or bottom and minimizing the increase in weight of each expanded bucket, it is possible to increase the amount of soil that can be stored in the expanded bucket at one time. In other words, it is possible to increase the amount of soil that can be removed at one time. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2 is a front view of the first expanded-bottom bucket. [Figure 2] This is an explanatory diagram showing the upper part of the expanded bottom hole being constructed using the first expanded bottom bucket. [Figure 3] FIG. 10 is a front view of the second expanded-bottom bucket. [Figure 4] This is an explanatory diagram of the state after the lower part of the expanded bottom hole has been constructed using the second expanded bottom bucket. [Figure 5] FIG. 1 is a side view of the earth drill with the bottom-enlarging bucket connected. DETAILED DESCRIPTION OF THE INVENTION

[0012] 1 to 5 show an example of an embodiment of the bottom-expanding bucket of the present invention, and as shown in Fig. 5, the earth drill 11 to which the bottom-expanding bucket 21 (31) is connected comprises a self-propelled base machine 12, a boom 13, a support arm 14, a kelly bar drive device 15 supported by the support arm 14, a kelly bar 16 driven to rotate by the kelly bar drive device 15, and a rotary table 17 provided below the kelly bar drive device 15 and rotating integrally with the kelly bar 16 while restricting its lifting and lowering, and the bottom-expanding bucket is detachably attached to the lower end of the kelly bar 16 protruding downward from the rotary table 17. The kelly bar 16 is connected to a wire rope 18 wound around a winch (not shown) provided on the base machine 12, and is movable up and down by winding or unwinding the wire rope 18 with the winch, and the bottom-expanding bucket 21 (31) rotates integrally with the kelly bar 16 and moves up and down.

[0013] The bottom-expanding bucket includes a first bottom-expanding bucket 21 and a second bottom-expanding bucket 31 that are replaceably attached to the tip of the kelly bar 16. As shown in Figure 1, the first bottom-expanding bucket 21 includes a cylindrical first bucket body 22, a stabilizer 23 attached to the upper end of the first bucket body 22, a bottom cover 22a attached to the lower end of the first bucket body 22, conical upper bottom-expanding wings 24, 24 that open and close an opening and that gradually increase in diameter downward when open, and a bottom-expanding wing drive device (not shown) that opens and closes the upper bottom-expanding wings 24, 24.

[0014] The upper flared wing 24 has one side edge (rotating base) rotatably attached to the vertical frames 22b, 22b of the first bucket body 22 using multiple hinge members 25 as rotation axes, and the other side edge (rotating end) has multiple excavation blades 26 arranged in succession. It is being done.

[0015] As shown in Figure 3, the second expanded bottom bucket 31 comprises a cylindrical second bucket body 32, a stabilizer 33 provided at the upper end of the second bucket body 32, a bottom cover 32a provided at the lower end of the second bucket body 32, truncated conical lower expanded bottom wings 34, 34 that open and close the opening and gradually increase in diameter downward when open, and a expanded bottom wing drive device (not shown) that opens and closes the lower expanded bottom wings 34, 34.

[0016] The lower bottom-expanding wing 34 has one side edge (rotating base) attached to the vertical frames 32b, 32b of the second bucket body 32 so as to be rotatable around multiple hinge members 35 as rotation axes, and the other side edge (rotating end) has multiple excavation blades 36 provided in succession. Furthermore, the bodies 22, 32 of the first bottom-expanding bucket 21 and the second bottom-expanding bucket 31 (the distance between the stabilizers 23, 33 and the bottom covers 22a, 32a) are approximately the same and are roughly equal to the height of the bottom-expanding hole 42 to be constructed, and the upper bottom-expanding wing 24 of the first bottom-expanding bucket 21 is provided at the upper end of the body 22, and the lower bottom-expanding wing 34 of the second bottom-expanding bucket 31 is provided at the lower end of the body 32.

[0017] The upper flared wing 24 and the lower flared wing 34 are formed by separating and dividing the conventional flared wing, which was previously formed as a single unit, into two upper and lower sections.In the upper flared wing 24 provided on the first flared bucket 21, only the upper 42a side of the flared hole 42 is constructed, and in the lower flared wing 34 provided on the second flared bucket 31, only the lower 42b side of the flared hole 42 is constructed.

[0018] When constructing a bottom-enlarged hole using the earth drill 11 configured as described above, first, as shown in Figures 1 and 2, the first bottom-enlarged bucket 21 is connected to the tip of the kelly bar 16. The first bottom-enlarged bucket 21 is then inserted into a vertical hole 41 previously excavated by an excavation bucket (not shown). While rotating at the bottom of the vertical hole 41, the upper bottom-enlarged blades 24 are gradually opened, gradually expanding the upper 42a side of the bottom-enlarged hole 42 in a tapered shape (the area indicated by diagonal lines in Figure 2). The excavated soil is then introduced along the inner surface of the upper bottom-enlarged blades 24 toward the first bucket body 22 and captured within the first bucket body 22. After a predetermined amount of excavation is completed, the upper bottom-enlarged blades 24 are closed, allowing the soil to be contained within the first bucket body 22. The first bottom-enlarged bucket 21 is then lifted up along with the soil, and the bottom cover 22a is opened at a predetermined location to remove the soil. This process is repeated several times to complete the construction of the upper 42a side of the bottom-enlarged hole 42.

[0019] When constructing the lower 42b side of the enlarged hole 42, the first enlarged bucket 21 is replaced with the second enlarged bucket 31 on the ground, as shown in Figures 3 and 4. The second enlarged bucket 31 is then inserted up to the upper 42a side of the already constructed enlarged hole 42, and the lower enlarged wing 34 is gradually opened to construct the lower 42b side of the enlarged hole 42, which will have the maximum enlarged diameter (the area indicated by diagonal lines in Figure 4). The excavated soil is introduced along the inner surface of the lower enlarged wing 34 toward the second bucket body 32 and is taken into the second bucket body 32. After the desired amount of excavation is completed, the lower enlarged wing 34 is closed, and the second enlarged bucket 31 is lifted with the soil held within the second bucket body 32, and the bottom cover 32a is opened to remove the soil. This process is repeated several times to construct the lower 42b side of the enlarged hole 42.

[0020] Thus, according to the present invention, two types of expander buckets, the first expander bucket 21 and the second expander bucket 31, are attached to the tip of the kelly bar in sequence for each excavation stage, enabling the expansion hole 42 to be constructed while minimizing the excavation resistance generated in the expander bucket. Furthermore, because the first expander bucket 21 and the second expander bucket 31 only have either the upper expander wing 24 or the lower expander wing 34, the weight of the expander bucket can be reduced, increasing the amount of soil and sand that can be removed at one time, reducing the number of times the soil removal work must be performed, and improving efficiency.

[0021] In addition, because excavation can be divided between the top and bottom (excavation can be divided between the upper and lower flared wings 24 only and the lower flared wings 34 only), excavation resistance can be minimized compared to excavating the top and bottom together as a single unit. Furthermore, since the total weight of the flared bucket and the soil weight is determined by the capacity of the excavator, by using only the upper or lower flared wings and minimizing the increase in weight of each flared bucket 21, 31, the amount of soil that can be stored in the flared bucket at one time can be increased. In other words, it is possible to increase the amount of soil that can be discharged at one time.

[0022] The present invention is not limited to the above-described embodiment, and the dimensional relationship between the upper and lower separated flared wings can be changed as appropriate based on the specifications of the flared bucket. [Explanation of symbols]

[0023] 11...Earth drill, 12...Base machine, 13...Boom, 14...Support arm, 15...Kelly bar drive device, 16...Kelly bar, 17...Rotary table, 18...Wire rope, 21...First expanded bottom bucket, 22...First bucket body, 22a...Bottom cover, 22b...Vertical frame, 23...Stabilizer, 24...Upper expanded bottom wing, 25...Hinge member, 26...Digging blade, 31...Second expanded bottom bucket, 32...Second bucket body, 32a...Bottom cover, 32b...Vertical frame, 33...Stabilizer, 34...Lower expanded bottom wing, 35...Hinge member, 36...Digging blade, 41...Vertical hole, 42...Expanded bottom hole, 42a...Upper part, 42b...Lower part

Claims

1. A bottom-expanding bucket is detachably attached to the tip of the kelly bar of an earth drill, and expands the bottom of a previously excavated vertical hole by opening bottom-expanding wings that are openably provided on the bucket body, thereby forming an enlarged bottom hole. The flared wing is divided into an upper flared wing that constructs the upper side of the flared hole and a lower flared wing that constructs the lower side of the flared hole, The expanded-bottom bucket comprises a first expanded-bottom bucket and a second expanded-bottom bucket which are interchangeably attached to the tip of the kelly bar, the first expanded-bottom bucket comprising only the upper expanded-bottom wing on the first bucket body, and the second expanded-bottom bucket comprising only the lower expanded-bottom wing on the second bucket body.

2. 2. A method for constructing a reamed hole using the reamed bucket described in claim 1, characterized in that the first reamed bucket is attached to the tip of the kelly bar, the upper side of the reamed hole is constructed, the first reamed bucket is lifted up, the first reamed bucket is removed from the tip of the kelly bar on the ground and replaced with the second reamed bucket, and the lower side of the reamed hole is constructed.

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