JPS63130820A - Excavator for cast-in-place pile - Google Patents

Abstract

PURPOSE:To permit a pile pit to be excavated with good efficiency even at narrow construction sites without the needs for boom by a method in which a kelly bar is hung down and held through a bucket by the winch of the excavator. CONSTITUTION:In an excavator to form a pile pit by turning a bucket 16 attached to the tip of a multi-stagewise extendible kelly bar 14, a rotator 20 thrusting through the kelly bar 14 is set on a vertically movable excavator body 15 with a leader 13. The vertically movable winch 18 of the bucket 16 attached to the tip of the kelly bar 14 is provided for the rotary frame 19 formed on the rotator 20. The kelly bar 14 can thus be hung down and held through the bucket 16 by the winch 18, and the operation can be performed with good efficiency even in extremely narrow construction sites.

Description

[Detailed description of the invention] [Field of industrial application] □ The present invention involves forming a pile hole in the ground with an excavation bucket, inserting reinforcing bars into the pile hole, and then pouring concrete into the site. This invention relates to an excavator used in the method of forming piles.

[Conventional technology]

Excavators used in conventional cast-in-place pile construction methods are, for example,
As shown in FIG. As shown in the figure, the conventional digging F
? + Machine 1 suspends and holds a Kelly bar 4 with a square cross section from the tip of a boom 3 attached to a crawler 2, etc.
A rotary drive device 5 is installed in the middle of the Kelly bar 4, and a bucket 6 for excavation is connected to the tip of the Kelly bar 4. To excavate a pile hole, the rotary drive device 5 rotates the excavation bucket 6 via the Kelly bar 4, and at the same time, a hydraulic device (not shown) formed on the upper part of the rotary drive device 5 excavates into the Kelly bar 4. It excavates underground while providing directional feed. When the inside of the excavation bucket 6 is full of excavated soil, the hanging wire 7 of the Kelly bar 4 is wound up with the winch 8, the whole is rotated laterally, and the excavated soil inside the excavation bucket 6 is discharged. Excavation is repeated in the same manner to form pile holes.

By the way, the Kelly bar 4 can be expanded and contracted in multiple stages, and has a total length of about 15 m in the contracted state.

Then, by expanding in stages as the excavation is carried out, 5
It is designed to be able to excavate pile holes of about 0m.

[Problem that the invention seeks to solve]

However, the total length of Kelly bar 4 in its contracted state is usually 1
Since it is 5 m, the dimension with the digging bucket 6 attached to the tip of the Kelly bar 4 is 24 to 25 m.

Therefore, the height and overall length of the boom 3 that suspends and holds the boom 3 must be greater than that, and the overall length of the boom 3 is usually 30 m or more. Therefore, in order to assemble this boom 3 on site, a vacant land of 40 m is required, including the dimensions of the crawler 2. In spite of this, there are cases where such a vast open space is not available at the construction site, and in such cases, it is not possible to assemble the boom 3, so other BH construction methods etc. have to be relied upon.

However, these construction methods had extremely serious drawbacks, such as slow progress in excavating the pile holes (inefficiency), prolonging the construction period, and increasing construction costs.

[Purpose of the invention]

The present invention improves and eliminates the above-mentioned conventional problems by providing a new excavator that does not require a boom, thereby efficiently excavating pile holes even in narrow construction sites. It was made so that it could be done.

[Means for solving problems]

The means of the present invention for solving the above problems is to excavate a pile hole by rotating an excavation bucket attached to the tip of a Kelly bar that expands and contracts in multiple stages, and after inserting reinforcing bars into the pile hole, This is an excavator used for the construction method of forming cast-in-place piles by placing concrete, and a rotating body formed by penetrating a Kelly bar is installed on the main body that is attached to a leader etc. and can be raised and lowered. Kelly bar on the frame formed above.
A winch is installed to raise and lower the excavation bucket attached to the tip of the excavation bucket.

[For production]

As is clear from the embodiment shown in FIGS. 1 and 2, by operating the drive motor 21, the rotating body 2°, the frame 19 erected thereon, and the Kelly bar passing through the rotating body 2o Each of the 14 members begins to rotate integrally. At the same time, the hydraulic system 22 feeds the Kelly bar 14 downward in FIG.

In this state, when the winch 18 is returned, the excavation bucket H6 starts descending and starts excavating underground. Once the bucket 16 is full of excavated pJ1 soil, the feed of the hydraulic system 22 is released and the winch 18 is hoisted. When the bucket 16 reaches the ground, the leader 13 is rotated to discharge the excavated soil in the bucket 16 and excavation is performed again.

As described above, in the excavator 11 according to the present invention, the kelly bar 14 is suspended and held by the winch 18 of the device body 15 via the bucket 16, and the upper end of the kelly bar 14 is held from the boom as in the conventional case. It is not meant to be suspended, thus eliminating the need for a conventional boom at all.

〔Example〕

The configuration of the present invention will be explained below based on the embodiments shown in the drawings.

FIG. 1 is a side view showing the entirety of an excavator 11 showing one embodiment of the present invention, and FIG. 2 is a partially enlarged perspective view thereof. As shown in the figure, a device main body 15 is attached to the leader 13 of the crawler 12 so as to be movable up and down. The device main body 15 has a fixed frame 26 that rotatably supports the rotating body 20 in a horizontal plane, and a mounting base 27 to the reader 13.
is installed. The rotating body 20 has external teeth 24 around the entire circumference of its annular outer surface, and is connected to a drive motor 21 by a chain or the like (not shown). The rotating body 20
Kelly bar 14 has a rectangular cross section and expands and contracts in multiple stages.
is placed through it. Further, around the Kelly bar 14, on the upper surface side of the rotating body 20, a rotating frame 19 is erected and fixed. A hydraulic device 22 that feeds the Kelly bar 14 in the excavation direction is arranged on the upper side of the rotating frame 19, and the Kelly bar 14 passes through this hydraulic device 22. Furthermore, winches 18 and 18 are fixedly installed on both sides of the intermediate portion of the rotating frame body 19. The other end of the wire 23.23 of the winch 18.18 is connected to the rotating body 2
Kelly bars 14 are inserted through the long holes 25 and 25 of 0, respectively.
It is connected to an excavation bucket 16 attached to the tip of the excavation bucket 16, and is configured to hang and hold the excavation bucket 16 and the Kelly bar 14.

Next, the operation mode of the excavator 11 according to the embodiment constructed as described above will be explained in the 11th! IJ will be explained with reference to FIG. 2 and FIG. 3 showing the process.

First, when the drive motor 21 is driven to rotate the rotating body 20 from the state shown in FIG. 1, the Kelly bar 14 and the rotating frame 19, which are held through the rotating body 20, begin to rotate integrally. Of course, it is clear that the excavating bucket 16 attached to the tip of the Kelly bar 14, the hydraulic system 22 and the winch 18°18 attached to the rotating frame 19 also start rotating in the same way. From this state, the hydraulic system 22 is operated to feed the kelly bar 14 in the digging direction (downward in Figure 1), and at the same time, the winches 18 and 18 are loosened to lower the kerat 16 with the digging bar, and the As shown in Figure 3 (a), excavation begins underground. During excavation, when the inside of the bucket 16 is filled with excavated soil, the feed of the hydraulic system 22 is released, and at the same time, the winch 18.18 is hoisted to bring the bucket 16 to the ground, and in this state, the leader 13 is rotated. The excavated soil in the bucket 16 is discharged. Then, excavation is started again, and this process is repeated thereafter. In this way, when the excavation has progressed to a certain extent as shown in the figure (bl), the excavation bucket 16 is taken out to the ground, and as shown in the figure (el), the soil near the ground (el) has collapsed. At the same time, the casing 28 is inserted so that the excavation work is not carried out, and at the same time, a drilling fluid such as a rebentonite aqueous solution is supplied from the fluid supply pipe 29 to facilitate the excavation work.Then, the above-mentioned excavation work is repeated, and as shown in FIG. As shown (pile hole 30 of a predetermined depth)
After digging, remove Kelly bar 14 and excavation bucket 1.
6 is taken out to the ground, and reinforcing bars 31 are inserted into the pile holes 30. Next, the tremie pipe 32 is inserted into the pile hole 30, and concrete 33 is poured into the pile hole 30 from the tremie pipe 32 (see Fig. 2 and (f) in the same figure). Gradually pull out 32, and
As shown in FIG.

By the way, the present invention is not limited to the above-described embodiments (appropriate changes can be made).
It is also possible to omit this and feed the Kelly bar 14 with the leader 13, and the driving means of the rotating body 20 and the driving method of the winches 18, 18, etc. can be replaced with other methods.

〔Effect of the invention〕

As explained above, according to the present invention, the Kelly bar can be suspended and supported via the excavation casing using the winch of the apparatus body attached to the leader, etc., and the conventional boom is not necessary.

Therefore, even on a construction site with an extremely narrow site, efficient pile hole excavation work can be performed using the Kelly bar and the excavation casing, making it possible to shorten the construction period and significantly reduce construction costs.

[Brief explanation of the drawing]

Fig. 1 is a side view showing the entire excavator according to an embodiment of the present invention, Fig. 2 is a partially enlarged perspective view thereof, and Fig. 3 (a)
to diagrams (phantom is a process diagram showing the construction order of cast-in-place piles, 4th
The figure is a side view showing a conventional excavator of this type.

Claims (1)

[Claims] 1. Rotate the excavation bucket attached to the tip of a Kelly bar that expands and contracts in multiple stages to excavate a pile hole, insert reinforcing bars into the pile hole, and then cast concrete to form a cast-in-place pile. An excavator used in the construction method, in which a rotating body formed by penetrating a kelly bar is installed on the main body that is attached to a leader etc. and can be freely raised and lowered, and a frame body formed on the rotating body is attached to the tip of the kelly bar. An excavator for cast-in-place piles, which is equipped with a winch for raising and lowering the excavation bucket.