Bottom-enlarging bucket and bottom-enlarging hole construction method

Abstract

To provide a large-sized bottom enlarged bucket and a bottom enlarged hole construction method, which can suppress increase of excavation resistance and efficiently discharge sediment.SOLUTION: A bottom enlarged blade 24 is formed to be divided into an upper bottom enlarged blade 24a and a lower bottom enlarged blade 24b. A bottom enraged blade driving device 25 to open and close the bottom enlarged blade 24 is connected to the upper bottom enlarged blade 24a. A bottom enlarged blade has first connection means to connect the upper bottom enlarged blade 24a and the lower bottom enlarged blade 24b so that the bottom enlarged blade driving device 25 can integrally open and close the upper bottom enlarged blade 24a and the lower bottom enlarged blade 24b, and second connection means to connect the lower bottom enlarged blade 24b and a bucket body 22 so that the lower bottom enlarged blade 24b is held in a closed state and only the upper bottom enlarged blade 24a can be opened and closed by the bottom enlarged blade driving device 25.SELECTED DRAWING: Figure 5

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 construct 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, by dividing the flared wings into two sections, upper and lower, the flared wings can be stored well within the bucket, and although it is possible to prevent the bucket body from becoming larger and reducing the efficiency of soil removal, it is not possible to operate the upper and lower flared wings independently, and it is not possible to prevent an increase in excavation resistance. Furthermore, if a drive device for the upper and lower flared wings were provided separately to operate the upper and lower flared wings independently, the weight of the flared bucket would increase, and there was a risk of reducing the efficiency of soil removal.

[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 suppress an increase in excavation resistance and efficiently remove soil and sand. [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 detachably 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 bottom-expanding wings that are attached to the bucket body in an openable and closable manner, thereby forming a bottom-expanding hole.The bottom-expanding bucket is formed by dividing an upper bottom-expanding wing and a lower bottom-expanding wing, and is characterized in that it is equipped with a first connecting means that connects a bottom-expanding wing drive device that opens and closes the bottom-expanding wing to the upper bottom-expanding wing, and connects the upper bottom-expanding wing and the lower bottom-expanding wing, allowing the upper bottom-expanding wing and the lower bottom-expanding wing to be opened and closed integrally by the bottom-expanding wing drive device, and a second connecting means that connects the lower bottom-expanding wing to the bucket body, keeps the lower bottom-expanding wing in a closed state, and allows only the upper bottom-expanding wing to be opened and closed by the bottom-expanding wing drive device.

[0008] Furthermore, it is preferable that the first connecting means is formed by a pair of first connecting brackets respectively provided on the upper flared wing and the lower flared wing, a pair of first pin insertion holes respectively formed in the pair of first connecting brackets, and a first connecting pin that is removably inserted across the pair of first pin insertion holes, and that the second connecting means is formed by a pair of second connecting brackets respectively provided on the lower flared wing and the bucket body, a pair of second pin insertion holes respectively formed in the pair of second connecting brackets, and a second connecting pin that is removably inserted across the pair of second pin insertion holes.

[0009] Furthermore, it is preferable that the first pin insertion hole and the second pin insertion hole are formed to have the same diameter, and that the first connecting pin and the second connecting pin are formed by the same connecting pin.

[0010] In addition, the method of constructing a bottom-expanding hole of the present invention is characterized in that, in the method of constructing a bottom-expanding hole using the above-mentioned bottom-expanding bucket, the second connecting means maintains the lower bottom-expanding wing in a closed state, and only the upper bottom-expanding wing can be opened and closed using the bottom-expanding wing drive device.After constructing the upper side of the bottom-expanding hole with the bottom-expanding bucket, the bottom-expanding bucket is lifted up, the second connecting means is released on the ground, the first connecting means connects the upper bottom-expanding wing and the lower bottom-expanding wing, and the top bottom-expanding wing and the lower bottom-expanding wing can be opened and closed integrally using the bottom-expanding wing drive device.This bucket is then placed on the upper side of the constructed bottom-expanding hole, and the lower side of the bottom-expanding hole is constructed continuous with the upper side of the bottom-expanding hole.

[0011] Furthermore, in the method for constructing a bottom-expanding hole using the above-mentioned bottom-expanding bucket, the first connecting means connects the upper bottom-expanding wing and the lower bottom-expanding wing, and the top and bottom-expanding wing and the bottom-expanding wing can be opened and closed integrally by the bottom-expanding wing drive device. The bottom-expanding hole is constructed by the bottom-expanding bucket to a predetermined diameter, and when the excavation resistance increases to a predetermined level, the top and bottom-expanding wing and the bottom-expanding wing are temporarily closed and the bottom-expanding bucket is lifted up, and the first connecting means is released on the ground, and the second connecting means closes the lower bottom-expanding wing. After constructing the upper side of the enlarged bottom hole with the enlarged bottom bucket, which is maintained in a fixed position and in which only the upper enlarged bottom wing can be opened and closed by the enlarged bottom wing drive device, the enlarged bottom bucket is lifted up on the ground, the second connecting means is released, and the upper and lower enlarged bottom wing are connected by the first connecting means.The enlarged bottom bucket, which can open and close the upper and lower enlarged bottom wing together by the enlarged bottom wing drive device, is then placed on the upper side of the enlarged bottom hole that has already been constructed, and the lower side of the enlarged bottom hole is constructed continuous with the upper side of the enlarged bottom hole. [Effects of the Invention]

[0012] According to the present invention, the upper and lower flaring wings function in sequence for each excavation stage, allowing for the construction of a flared hole while minimizing excavation resistance, and furthermore, soil removal can be performed effectively. Furthermore, selective pin connections allow for the upper flaring wings to be operated independently, or the upper and lower flaring wings to be operated together. Furthermore, the use of the same flaring wing drive device simplifies the mechanism and prevents the weight of the flaring bucket from increasing. In other words, it is possible to increase the amount of soil and sand that can be removed with one expansion, improving construction efficiency. Furthermore, by using the same connecting pin for multiple pin connections, parts can be standardized and the connecting pin replacement work can be performed quickly and in a short time.

[0013] Furthermore, 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 is minimized compared to excavating the top and bottom together. Furthermore, because excavation resistance can be reduced, construction can be carried out smoothly. In addition, it is less likely that excavation resistance will become so great that excavation will be impossible (construction work will be halted). Therefore, soil can be removed effectively. Furthermore, since the total weight of the expanded bucket and the soil weight is determined by the capacity of the excavator, by minimizing the increase in the weight of the expanded bucket, it is possible to increase the amount of soil that can be stored in the expanded bucket. In other words, it is possible to increase the amount of soil that can be excavated with one expansion. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a front view of a wide-bottom bucket showing an example of the present invention. FIG. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II of FIG. [Figure 3] This is a front view of a flared bucket with only the upper flared wings open. [Figure 4] This is an explanatory diagram of the main parts of a flared bucket with only the upper flared wings open. [Figure 5] This is a front view of a flared bucket in which the upper and lower flared wings are opened together. [Figure 6] 6 is a cross-sectional view taken along the line VI-VI in FIG. 5. [Figure 7] This is an explanatory diagram of the main parts of a flared bucket in which the upper and lower flared wings are opened together. [Figure 8] This is an explanatory diagram of the state after a bottom-widening hole has been constructed using a bottom-widening bucket. [Figure 9] FIG. 1 is a side view of the earth drill with the bottom-enlarging bucket connected. DETAILED DESCRIPTION OF THE INVENTION

[0015] Figures 1 to 9 show an example of an expanded-bottom bucket according to the present invention. The portions circled by dashed lines in Figures 3 and 5 are shown in perspective views in Figures 4 and 7, respectively, as essential parts of the expanded-bottom bucket. The expanded-bottom bucket 21 is connected to an earth drill 11 for use, as shown in Figure 9. The earth drill 11 includes a self-propelled base machine 12, a boom 13, a support arm 14, a kelly bar drive unit 15 supported by the support arm 14, a kelly bar 16 driven to rotate by the kelly bar drive unit 15, and a rotary table 17 located below the kelly bar drive unit 15 and rotating integrally with the kelly bar 16 while its vertical movement is restricted. The expanded-bottom bucket 21 is detachably attached to the lower end of the kelly bar 16, which projects 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 capable of moving freely in the vertical direction as the wire rope 18 is wound up or unwound by the winch, and the wide-bottom bucket 21 rotates integrally with the kelly bar 16 and moves up and down.

[0016] As shown in Figures 1 and 6, the bottom-flared bucket 21 comprises a cylindrical bucket body 22 with two openings 22a, 22a formed in the peripheral wall, a stabilizer 23 provided at the upper end of the bucket body 22, a bottom cover 22b provided at the lower end of the bucket body 22, conical bottom-flared wings 24, 24 that open and close both openings 22a, 22a and gradually increase in diameter downward when in the open state (Figure 5), and a bottom-flared wing drive device 25 that opens and closes the bottom-flared wings 24, 24.

[0017] Each flared wing 24 is divided into an upper flared wing 24a and a lower flared wing 24b. One side edge (rotating base) of the upper and lower flared wing 24a, 24b is attached to the vertical frames 22c, 22c of the bucket body 22 via multiple hinge members 26 so as to be rotatable relative to the opening 22a, and multiple excavation blades 27 are provided continuously on the other side edge (rotating end).

[0018] As shown in Figures 4 and 7, the upper flared wing 24a and the lower flared wing 24b are each provided with a pair of first connecting brackets 28a, 28b, and the upper flared wing 24a and the lower flared wing 24b are connected together by inserting a connecting pin 29 (the first connecting pin of the present invention) through the first pin insertion hole 28c formed in one first connecting bracket 28a and the first pin insertion hole 28c formed in the other first connecting bracket 28b (Figure 7, first connecting means of claim 1). Furthermore, a pair of second connecting brackets 30a, 30b are provided on the lower flared wing 24b and the bucket body 22, and a connecting pin 29 (the second connecting pin of the present invention) is inserted through a second pin insertion hole 30c formed in one second connecting bracket 30a and a second pin insertion hole 30c formed in the other second connecting bracket 30b, thereby connecting the lower flared wing 24b and the bucket body 22 (FIG. 4, second connecting means of claim 1). Furthermore, the first pin insertion holes 28c, 28c and the second pin insertion holes 30c, 30c are formed with the same diameter, and the same connecting pin is used for the connecting pin 29. The connecting pin 29 is selectively inserted into the first pin insertion hole 28c and the second pin insertion hole 30c.

[0019] As shown in Figure 6, the flared wing drive device 25 comprises a square pillar 25a erected in the center of the bucket body, a lifting bracket 25b attached to the square pillar 25a so that it can be raised and lowered, a pair of hydraulic cylinders 25c, 25c that raise and lower the lifting bracket 25b using hydraulic pressure supplied from the base machine 12, and a pair of link members 25d, 25d that connect one end to the lifting bracket 25b and the other end to the lower side of the upper flared wing 24a.

[0020] When the hydraulic cylinders 25c, 25c are extended while the second connecting brackets 30a, 30b are connected by the connecting pin 29, the lift-up bracket 25b descends, and the other ends (lower ends) of the link members 25d, 25d collapse while pushing only the upper flared wing 24a toward the outer periphery of the bucket body 22. As a result, the upper flared wing 24a rotates in the radial direction of the bucket body 22, from a closed state in which it closes the opening 22a to an open state in which it opens the opening 22a, while keeping the lower flared wing 24b closed. Meanwhile, when the hydraulic cylinders 25c, 25c are contracted, the lift-up bracket 25b ascends, and the other ends (lower ends) of the link members 25d, 25d rise while moving toward the bucket body 22. As a result, the upper flared wing 24a rotates from the open state to a closed state in which it closes the opening 22a.

[0021] Furthermore, when the hydraulic cylinders 25c, 25c are extended while the first connecting brackets 28a, 28b are connected by the connecting pin 29, the lift-up bracket 25b descends, and accordingly, the other ends (lower ends) of the link members 25d, 25d collapse while pushing the upper flared wing 24a and the lower flared wing 24b open toward the outer periphery of the bucket body 22. As a result, the upper flared wing 24a and the lower flared wing 24b rotate integrally in the radial direction of the bucket body 22, from a closed state in which the opening 22a is closed to an open state in which the opening 22a is opened. On the other hand, when the hydraulic cylinders 25c, 25c are contracted, the lift-up bracket 25b ascends, and accordingly, the other ends (lower ends) of the link members 25d, 25d rise while moving toward the bucket body 22. As a result, the upper flared wing 24a and the lower flared wing 24b rotate integrally from the open state described above to a closed state in which the opening 22a is closed.

[0022] 1 and 2, a calibration mechanism 31 is provided between the lifting bracket 25b and the bucket body 22. The calibration mechanism 31 correlates the opening degree of the flared wings 24, which open and close by the extension and contraction of the hydraulic cylinders 25c, with the flow rate of hydraulic oil supplied to the hydraulic cylinders 25c. The calibration mechanism 31 includes a gauge member 31a provided on the bucket body 22 and a bar member 31b provided on the lifting bracket 25b that moves along the gauge member 31a as the lifting bracket 25b moves up and down. The gauge member 31a has a scale that indicates the opening degree of the flared wings 24. This allows the opening degree of the flared wings 24 to be accurately determined by reading the scale indicated by the bar member 31b.

[0023] When constructing a bottom-expanding hole using the bottom-expanding bucket 21 configured as described above, first align the second connecting brackets 30a, 30b, insert the connecting pin 29 through the pair of second pin insertion holes 30c, 30c, and then insert the bottom-expanding bucket 21, with only the upper bottom-expanding wing 24a openable and closable by the bottom-expanding wing drive device 25, into a vertical hole previously excavated with an excavation bucket (not shown). While rotating at the bottom of the vertical hole, the upper bottom-expanding wing 24a gradually opens, tapering the upper 32a side of the bottom-expanding hole 32, as shown in Figure 8(A). The excavated soil is introduced along the inner surface of the upper bottom-expanding wing 24a toward the bucket body 22 and is captured within the bucket body 22. After a predetermined amount of excavation is completed, the upper bottom-expanding wing 24a is closed, allowing the soil to be contained within the bucket body 22. At this time, the shallow bottom cover 22b and the multiple discharge ports 24c provided on the upper flared wing 24a prevent excess soil from being taken in, allowing the maximum amount of soil corresponding to the lifting capacity of the earth drill 11 to be held in the bucket body 22. The flared bucket 21 is then lifted up along with the soil, and the bottom cover 22b is opened at a predetermined location to discharge the soil. This process is repeated several times to complete the upper side of the flared hole.

[0024] To construct the lower side of the flared hole, remove the connecting pin 29 from the second pin insertion holes 30c, 30c on the ground, align the first connecting brackets 28a, 28b, and insert the connecting pin 29 through the pair of first pin insertion holes 28c, 28c, allowing the upper flared wing 24a and the lower flared wing 24b to open and close together. The flared bucket 21 is then inserted to the bottom of the vertical hole (the depth at which the upper flared wing 24a opens at the upper side of the already constructed flared hole). While gradually opening the upper flared wing 24a and the lower flared wing 24b together, the lower part 32b of the flared hole 32, which will have the maximum flared diameter, is constructed, as shown in Figure 8(B). The excavated soil is introduced along the inner surface of the lower flared wing 24b toward the bucket body 22 and is then drawn into the bucket body 22. After a predetermined amount of excavation has been completed, the upper and lower flared wings 24a and 24b are closed together, and the flared bucket 21 is lifted up with the soil held within the bucket body 22, and the bottom cover 22b is opened to remove the soil. This process is repeated several times to complete the lower part of the flared hole.

[0025] As described above, according to the present invention, the upper and lower flaring wings 24a, 24b function in sequence for each excavation stage, thereby minimizing excavation resistance while constructing a flared hole and enabling effective soil removal. Furthermore, selective pin coupling allows the upper flaring wing 24a to be operated independently, or the upper flaring wing 24a and the lower flaring wing 24b to be operated together. Furthermore, the use of the same flaring wing drive device 25 simplifies the mechanism and prevents the weight of the flaring bucket 21 from increasing. This increases the amount of soil and sand that can be removed with one expansion, improving construction efficiency. Furthermore, by using the same connecting pin 29 for multiple pin couplings, parts can be standardized and the connecting pin 29 can be replaced quickly and quickly.

[0026] Furthermore, because excavation can be divided between the top and bottom (excavation can be divided between the upper and lower flared wings 24a and 24b), excavation resistance can be minimized compared to excavating the top and bottom together. Furthermore, because excavation resistance can be reduced, construction can be carried out smoothly. In addition, it is less likely that excavation resistance will become so great that excavation will be impossible (construction work will be halted). Therefore, soil can be removed effectively. Furthermore, since the total weight of the flared bucket and the soil weight is determined by the capacity of the excavator, by minimizing the increase in the weight of the flared bucket 21, it is possible to increase the amount of soil that can be stored in the flared bucket 21. In other words, it is possible to increase the amount of soil that can be excavated with one expansion.

[0027] The present invention is not limited to the above-described embodiment, and the first and second pin insertion holes do not have to be formed with the same diameter, and the first and second connecting pins may be provided separately. Furthermore, the structures of the first and second connecting means are arbitrary. Alternatively, the upper and lower expanding wings may be opened and closed integrally from the beginning, and the bottom may be expanded to a predetermined diameter. When the excavation resistance increases above a predetermined level, only the upper expanding wing may be made operable, and the bottom may then be expanded integrally. [Explanation of symbols]

[0028] 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...Flat-bottom bucket, 22...Bucket body, 22a...Opening, 22b...Bottom cover, 22c...Vertical frame, 23...Stabilizer, 24...Flat-bottom wing, 24a...Upper flat-bottom wing, 24b...Lower flat-bottom wing, 24c...Soil discharge port, 25...Flat-bottom wing drive device 25a...rectangular column, 25b...lifting bracket, 25c...hydraulic cylinder, 25d...link member, 26...hinge member, 27...cutting blade, 28a, 28b...first connecting bracket, 28c...first pin insertion hole, 29...connecting pin, 30a, 30b...second connecting bracket, 30c...second pin insertion hole, 31...calibration mechanism, 31a...gauge member, 31b...bar member, 32...enlarged bottom hole, 32a...upper portion, 32b...lower portion

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 bottom flaring wing is formed by dividing it into an upper bottom flaring wing and a lower bottom flaring wing, and is equipped with a bottom flaring wing drive device that opens and closes the top flaring wing to the upper bottom flaring wing, a first connecting means that connects the top flaring wing to the lower bottom flaring wing and allows the top flaring wing and the bottom flaring wing to be opened and closed integrally by the bottom flaring wing drive device, and a second connecting means that connects the bottom flaring wing to the bucket body, keeps the lower bottom flaring wing in a closed state, and allows only the top flaring wing to be opened and closed by the bottom flaring wing drive device.

2. The expanded-bottom bucket described in claim 1, characterized in that the first connecting means is formed by a pair of first connecting brackets provided on the upper and lower expanded-bottom wings, respectively, a pair of first pin insertion holes formed in each of the pair of first connecting brackets, and a first connecting pin that is removably inserted through the pair of first pin insertion holes, and the second connecting means is formed by a pair of second connecting brackets provided on the lower expanded-bottom wings and the bucket body, respectively, a pair of second pin insertion holes formed in each of the pair of second connecting brackets, and a second connecting pin that is removably inserted through the pair of second pin insertion holes.

3. An expanded bottom bucket as described in claim 2, characterized in that the first pin insertion hole and the second pin insertion hole are formed with the same diameter, and the first connecting pin and the second connecting pin are formed from the same connecting pin.

4. 4. A method for constructing a bottom-expanding hole using a bottom-expanding bucket as described in any one of claims 1 to 3, characterized in that after constructing the upper side of the bottom-expanding hole with the bottom-expanding bucket, which maintains the lower bottom-expanding wing in a closed state using the second connecting means and allows only the upper bottom-expanding wing to be opened and closed using the bottom-expanding wing drive device, the bottom-expanding bucket is lifted up, the second connecting means is released on the ground, the upper bottom-expanding wing and the lower bottom-expanding wing are connected using the first connecting means, and the upper bottom-expanding wing and the lower bottom-expanding wing can be opened and closed integrally using the bottom-expanding wing drive device. This method for constructing a bottom-expanding hole is characterized in that the lower side of the bottom-expanding hole is constructed continuous with the upper side of the bottom-expanding hole.

5. 4. A method for constructing a bottom-enlarged hole using a bottom-enlarged bucket according to claim 1, wherein the first connecting means connects the upper bottom-enlarged wing and the lower bottom-enlarged wing, and the upper bottom-enlarged wing and the lower bottom-enlarged wing can be opened and closed integrally by the bottom-enlarged wing drive device. The bottom-enlarged hole is constructed by using the bottom-enlarged bucket to widen it to a predetermined diameter, and when the excavation resistance increases to a predetermined level or more, the upper bottom-enlarged wing and the lower bottom-enlarged wing are temporarily closed, the bottom-enlarged bucket is lifted, the first connecting means is released on the ground, and the second connecting means is used to open and close the lower bottom-enlarged wing. A method for constructing a bottom-expanding hole, characterized in that after constructing the upper side of the bottom-expanding hole with a bottom-expanding bucket in which only the upper bottom-expanding wing can be opened and closed by the bottom-expanding wing drive device and the bottom-expanding bucket is maintained in a closed state, the second connecting means is released on the ground, the upper bottom-expanding wing and the lower bottom-expanding wing are connected by the first connecting means, and the bottom-expanding bucket, which can be opened and closed integrally by the bottom-expanding wing drive device, is placed on the upper side of the constructed bottom-expanding hole, and the lower side of the bottom-expanding hole is constructed continuous with the upper side of the bottom-expanding hole.

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