JP3845562B2 - Drilling bucket device for diameter expansion of cast-in-place piles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an excavation bucket device for accurately forming a plurality of ribs on the surface of a pile body of a cast-in-place concrete pile.
[0002]
[Prior art]
In Japanese Patent No. 2548661, the inventor increases the support strength of the pile and controls the amount of settlement at the head of the pile in a hard ground where slippage occurs between the ground and the outer peripheral surface of the pile and friction cannot be expected. As shown in FIG. 5, it has been proposed to increase the diameter of the peripheral wall of the pile hole so as to bite the ring-shaped rib into the ground.
[0003]
Since this cast-in-place concrete pile is made to act on a pile by the ring-shaped rib (protrusion) which formed the shear resistance of the ground around a pile hole in the pile peripheral surface, it can increase a supporting force significantly. According to the model experiment of the ribbed pile, the improvement of the supporting force by 1.5 to 2.0 times or more is recognized.
[0004]
Specifically, as an apparatus for forming a groove for forming a rib in the ground on a peripheral wall of a pile hole, the present applicant provides a diameter expanding device on the upper part of the bucket as disclosed in Japanese Patent No. 2850073, and rotates it. Proposing to reverse the drive shaft and project the blade expansion scraper of the diameter expansion device to form a groove in the peripheral wall of the pile hole, and as a device to create a rib in the lower part of the cast-in-place pile, A separate diameter expansion bucket (utility model registration No. 3026014) was proposed.
[0005]
When creating multiple ribs, the diameter expansion bucket is expanded to form a ring-shaped groove for the rib on the pile peripheral wall, the diameter expansion device is folded, and the pile hole is further excavated in the depth direction. The diameter expansion work was performed again with the diameter expansion bucket.
[0006]
[Problems to be solved by the invention]
It is extremely inefficient to build ribs one by one with one enlarged bucket, and every time the excavation bucket and the enlarged bucket are replaced, impurities such as dirt and earth and sand are likely to enter the connecting part of the hydraulic hose. It may also cause a failure of the hydraulic cylinder.
Moreover, even if it tries to create ribs at a predetermined interval (pitch), it is difficult to control the excavation depth, and the shape accuracy of the ribs becomes extremely bad due to shaft runout, etc. Therefore, the bearing capacity of the pile does not increase as expected Problems arise.
[0007]
Further, when the excavation bucket is raised and lowered in the bentonite stabilizing liquid filled in the excavation hole, the formed upper rib may rub against the bucket drum or collapse due to the negative pressure of the muddy water flow in the stabilizing liquid.
In addition, if a plurality of diameter expansion devices are simply provided in one bucket, it is necessary to add a hydraulic hose for supplying pressure oil to the hydraulic cylinder for expanding the blades, resulting in a complicated structure and failure. As a result, the maintenance becomes complicated and the operation rate of the excavation bucket decreases.
[0008]
[Means for Solving the Problems]
Therefore, by providing a control device for controlling the supply oil so as to operate independently or simultaneously on the hydraulic drive device for diameter expansion of a plurality of diameter expansion devices, the peripheral wall of the pile hole is accurately spaced without complicating the structure. Ribs can be formed on the plate.
[0009]
A solenoid valve is attached to a hydraulic hose that supplies pressure oil to the hydraulic device, and hydraulic cylinders that drive the blade expander scraper of the diameter expansion device are operated simultaneously or individually. When the excavation bucket reaches a predetermined depth at which ribs are formed, the rotary shaft is reversely rotated so that the excavation bucket does not dig in the depth direction, and the wing scraper of the diameter expansion device is expanded to perform the diameter expansion excavation, and the pile hole Create ribs on the peripheral wall. The earth and sand shaved off by expanding the diameter is taken into the lower bucket and discharged to the ground.
[0010]
When constructing the upper and lower ribs simultaneously, the wing spreader scraper is operated at the same time up and down. At that time, the solenoid valve is opened in both directions and the upper and lower hydraulic cylinders are operated simultaneously. Further, by controlling the solenoid valve, it is possible to individually operate the blade expanding scraper.
To create several stages of ribs at three or more locations, install a corresponding number of solenoid valves or add several stages of solenoid valves to operate multiple hydraulic cylinders.
According to the above method, it is possible to create a plurality of ribs with a single excavation bucket device, and it is possible to simultaneously create highly accurate ribs with respect to the shape and pitch of the ribs.
[0011]
【Example】
FIG. 1 is a front view of the excavation bucket device for diameter expansion of the present invention, and FIG. 2 is a plan view. FIG. 4 is an explanatory diagram of a construction state.
A bucket 1 is attached to the tip of the rotary excavation shaft 10, and a bottom lid opening / closing device 11 is provided at the bottom of the bucket 1.
A diameter expansion device 2 is attached to the excavation shaft 10 at a predetermined interval above the bucket 1. The diameter expansion device 2 is attached to the excavation shaft 10 at a predetermined interval so that a plurality of arc-shaped expansion blade scrapers 20 driven by a hydraulic cylinder are cylindrical in a folded state.
[0012]
The hydraulic cylinder 3 is for expanding the blade-expanding scraper 20 and operates by opening and closing the electromagnetic valve. In addition, when operating three or more blade spreader scrapers, electromagnetic valves (not shown) corresponding to the number of scrapers are attached. The position of the electromagnetic valve can be installed at an appropriate position in the middle of the hydraulic hose.
[0013]
The diameter expansion device 2 expands the peripheral wall of the excavation hole to form a ring-shaped rib on the hole peripheral wall, and the diameter expansion device becomes a cylindrical shape slightly smaller than the diameter of the pile hole in the folded state. It functions as a stabilizer when excavating pile holes so that the holes are accurately formed vertically when drilling holes. Moreover, the bucket 1 assists the diameter expanding device 2 to form an accurate groove in the peripheral wall of the hole.
[0014]
In the diameter expansion device 2, the base ends of a plurality of forward and reverse rotating blade scrapers 20 are pivotally supported via pins 22 at the respective distal ends of a frame 21 assembled with a cross-shaped member. . The blade spread scraper 20 is formed in a circular arc shape in cross section so as to have a cylindrical shape with its upper and lower surfaces opened in a closed state. An excavation bit 23 is provided at the tip of the wing-scraper 20, and a forward hydraulic cylinder and a reverse hydraulic cylinder are interposed between the plate-like earth and sand guide plate and the frame 21. Then, the wing spreader scraper 20 is opened and closed.
[0015]
The rotary excavation shaft 10 is rotated and a pile hole is excavated by the bucket 1 at the tip. During the excavation, the diameter expansion device 2 is closed in a cylindrical shape and functions as a stabilizer to prevent a significant blurring of the bucket 1. To do.
In the case of forming the rib, the wing scraper 20 constituting the outer frame of the diameter expanding device 2 is opened outward by operating the hydraulic cylinder for reverse rotation, the pin 22 as an axis, the rotary excavation shaft 10 is reversed, The wing-scraper 20 is digged into the peripheral wall of the hole to form a rib groove.
[0016]
The blade spread scraper 20 is replaceable and is replaced with one having an appropriate shape in accordance with the cross-sectional shape of the rib (projection).
While the rib is formed, the bucket 1 is reversed or the bucket is suspended to stop excavation in the depth direction. The earth and sand on the peripheral wall of the excavation hole scraped off by the spreader scraper 20 moves to the center along the guide plate 24 of the spreader scraper 20 and is accumulated in the lower bucket 1.
The earth and sand accumulated in the bucket 1 is discharged by closing the wing scraper 20 with a hydraulic cylinder and pulling it up to the ground.
[0017]
FIG. 3 is a plan view of another embodiment of the diameter expansion device 2, in which a hydraulic cylinder 3 is arranged in parallel to the rotary excavation shaft 10, and the tip of the piston of the hydraulic cylinder 3 is connected to a link mechanism 31. It is. By the extension of the hydraulic cylinder 3, the link mechanism 31 opens the blade expanding scraper 20 outward with the pin 22 as a fulcrum. By reversing the rotary excavation shaft 10, the wing scraper 20 scrapes the peripheral wall of the pile hole and forms a ring-shaped groove.
[0018]
【The invention's effect】
In the present invention, a diameter expansion device having blade expansion scrapers in two or several places is attached to one diameter expansion excavation bucket device, and one hydraulic hose is branched, and pressure oil is individually supplied by a solenoid valve. Since the hydraulic cylinders of each wing scraper are operated by controlling the number of the wing scrapers, it is possible to operate a plurality of diameter expansion devices simultaneously or individually, and to create a plurality of ribs accurately and efficiently. it can.
Further, since the bucket and the diameter expanding device are the other stabilizers, the excavation hole and the rib can be accurately formed.
[0019]
The scraper of the diameter expanding device is opened by an opening / closing drive member to form a rib, but a claw mark remains on the wall surface around the hole by the excavating bit provided at the tip of the scraper. Therefore, the diameter expansion device is reversed with the scraper opened and pressed by the arcuate body of the scraper, and the earth and sand are pressed so as to finish the wall surface to finish a smooth excavation surface. By this finishing, the arching action of the excavation surface can be expected, and the ring-shaped groove can be further stabilized.
In addition, since the diameter expanding device is a hollow cylindrical shape whose upper and lower surfaces are open, when the bucket moves up and down in the excavation hole, it can be constructed in the same state as a conventional earth drill method. Although the earth and sand scraped off by the scraper of the diameter expanding device settles in the muddy water to the bottom of the hole, since the earth and sand can be collected in the bucket immediately below, generation of slime can be prevented.
[Brief description of the drawings]
FIG. 1 is a front view of a drilling bucket device for diameter expansion.
FIG. 2 is a plan view of the diameter expanding device.
FIG. 3 is a plan view of another embodiment of the diameter expansion device.
FIG. 4 is an explanatory diagram of a construction state.
FIG. 5 is a cross-sectional view of a ribbed cast-in-place concrete pile.
[Explanation of symbols]
1 bucket
10 Rotating drilling shaft
2 Diameter expansion device
20 Wing expansion scraper
3 Hydraulic cylinder

Claims (1)

A bucket that is attached to the tip of the rotary excavation shaft and is suspended in the air when the rotary excavation shaft reverses, and has a bladed scraper that can be opened and closed by a hydraulic device above the bucket. During drilling of pile holes, a plurality of diameter expansion devices that are folded into a cylindrical shape and function as stabilizers are provided at intervals, and control is performed to control the oil supplied to the hydraulic system so that the diameter expansion devices are operated individually or simultaneously The excavation bucket apparatus for diameter expansion of the cast-in-place pile where the apparatus is provided.

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