JPS5845533B2 - Grab bucket for underground continuous wall excavation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention operates on an underground continuous wall in an underground stabilizing liquid, excavates the ground with the cutting edge of a grab bucket, and at the same time discharges the excavated earth and sand together with the stabilizing liquid by an air lift. This relates to a grab bucket during excavation of an underground continuous wall that is descending.

Conventionally, in various clamshell type grab buckets, the cutting edges of the left and right grabs dig into the ground to excavate. Because it is localized so that it digs into the ground with a constant circular arc trajectory, it has the disadvantage that it cannot perform appropriate excavation that is suitable for each geology, from soft to hard ground, and the excavation efficiency in hard ground is extremely poor. This also resulted in an extreme imbalance between excavation speed and soil removal capacity.

Particularly when excavating hard ground containing gravel layers, cobblestones, boulders, etc., the digging resistance of the grab edge increases and the excavation force deteriorates, making excavation difficult and disturbing the surrounding and tip ground, or it may become impossible to do so. The excessive excavation causes holes to be made, and the cutting edge tends to wear out, which significantly reduces the accuracy of excavating underground walls.

In addition, when excavating with conventional packets, the final excavated bottom surface was not flat, but curved and concave, so it was necessary to excavate the unexcavated portions at the corners and perform corrective excavation to finish the bottom surface flat.

Furthermore, in the case of the conventional air lift reverse earth removal system, the excavated earth and sand was not discharged effectively and properly with the claw blade of the grab, and the excavated earth and sand was processed slowly and the earth removal efficiency was very poor.

In addition, in the past, the excavated soil was not discharged smoothly and effectively, so the residual soil that was not sucked out and discharged immediately disturbed the stabilizing liquid and promoted the formation of floating slime, which settled over time and deposited on the bottom of the excavation at the end of the excavation. This method increases the thickness of the deposited slime, making removal of the precipitated slime extremely difficult, ie, the bottom is rough, and has the disadvantage that it also has a negative effect on the behavior of the excavated wall surface.

This invention was made in view of the above, and includes a claw rod having a plurality of comb-like claw blades at the tips of the left and right gloves which are pivotally attached to the lower part of the frame by a glove opening/closing mechanism so as to be freely openable and closable.
Underground continuous wall excavation made by pivoting each of the blades so that the angle of the blade can be adjusted by a cylinder pivotally attached to the inner surface of the grab, and an air lift suction pipe that opens near the excavation part by the claw blade provided on the inner surface of the glove and connected to the air lift hose. The purpose of this invention is to provide a grab bucket for use in the past to eliminate the various drawbacks of the prior art.

Next, an embodiment of the grab bucket of the present invention shown in the drawings will be specifically described.

Reference numeral 1 designates a frame of the packet, on which grabs 2 on the left and right sides at the bottom are pivoted by a pivot 3 so as to be freely openable and closable.

Reference numeral 4 denotes an elevating frame that can be raised and lowered horizontally along the guides on both the left and right walls of the frame 1, and the tips of the piston rods of vertical operation cylinders 5 and 5, which are attached to the left and right sides of the upper part of the frame 1 with clevises, respectively, are pivoted. connected.

Further, the tips of rods 6.6 whose proximal ends are pivotally connected to the lower surfaces of the left and right sides of the lifting frame 4 are pivotally connected to the left and right grabs 2, respectively.

The elevator frame 4 is raised and lowered by the operation of the left and right operating cylinders 5, 5, and the left and right grabs 2 are opened and closed via rods 6, respectively.

Reference numeral 7 denotes a claw rod having a plurality of comb-like claw blades 8 at its tip, and is rotatably attached to the tips of the left and right gloves 2 by pivots 9, respectively.

The tips of the piston rods 11 of the cylinders 10 each attached to the inner surface of the glove 2 with a clevis are pivotally connected to the base ends of the claw rods 7, and the angle of the cutting edge of the claw blades 8 is freely adjusted by the operation of the cylinders 10. It is configured so that it can be used.

Further, on the inner surfaces of the left and right grabs 2, air lift suction pipes 12 having openings 12a near the excavated portions by the claw blades 8 are provided, respectively, and are connected to flexible air lift hoses 13.

Reference numeral 14 designates a telescope connecting pipe of an intermediate joint of the air lift hose 13, whose upper end is attached to the upper part of the frame 1 and whose lower end is attached to the lifting frame 4.

Reference numeral 15 denotes an air hose whose tip end is introduced near the opening 12a of the air lift suction pipe 12.

The grab bucket configured as described above is suspended by a wire rope 16 from a dedicated tower equipped with a winch on the ground for excavation.

It should be noted that the above-mentioned grab bucket is of course used not only for excavating by suspending it with a wire rope 16, but also for excavating by attaching it to the tip of a rod, such as in a Kelly-type excavator. It is.

In FIG. 1, the grab bucket is the pre-polling 17
is suspended in a drilling hole 18 filled with stabilizing fluid, and when the left and right operation cylinders 5 are operated by remote control on the ground, the open left and right grabs 2 are opened, respectively. When the left and right grabs 2 are rotated closed, the claw blades 8 at the tips of the left and right grabs 2 touch the ground 19.
Dig into the hole with even force to perform excavation.

At the same time, the excavated earth and sand are immediately discharged to the ground through the airlift suction pipe 12 and the airlift hose 13 along with the stabilizing liquid by the airlift action of the air pumped from the ground by the air hose 15. It is separated from the stabilizing liquid and the earth and sand are removed.
After purification, the stabilizer is collected in a tank, fine particles are precipitated and removed, and then returned to the trench using a bond.

Then, the grab buckets are lowered one after another as appropriate, and the underground continuous wall is excavated by the same action as described above.

In the case of excavating the above-mentioned ground 19, the cylinders 10 are actuated as appropriate by remote control on the ground, the claw rods 7 of the left and right grabs 2 are rotated, and the cutting edge angle of the claw blade 8 is adjusted to the ground 19.
The excavation will be carried out with appropriate adjustments and selections in accordance with the geology of 9.

As described above, the grab bucket of the present invention has a claw rod 7 having a plurality of claw blades 8 in a comb-teeth shape at the tips of the left and right grabs 2, and a cylinder 10 pivotally mounted on the inner surface of the grab 2 to adjust the angle of the cutting edge. Since it is pivotably mounted in an adjustable manner, the angle of the edge of the claw blade 8 can be arbitrarily selected regardless of the rotation angle of the grab 2. In other words, by adjusting the edge angle of the claw blade 8 to suit the soft or hard ground. , it has the outstanding effect of being able to perform appropriate excavation with the most ideal cutting edge angle for any type of rock, and achieving a high level of excavation efficiency.

Furthermore, by adjusting the angle of the cutting edge of the claw blade 8 of the grab 2, the digging force may deteriorate even in hard ground containing gravel layers, cobblestones, boulders, etc., or holes may be formed due to forced digging, or the claw may Blade 8
This has the effect of allowing advanced and efficient excavation to be carried out smoothly without causing any wear on the cutting edge and reducing excavation accuracy.

In addition, by appropriately adjusting the angle of the cutting edge of the claw blade 8 so that the trajectory of the cutting edge follows the trajectory P shown in Fig. 1, the final bottom surface of the excavation can be formed flat, so that corners are not left unexcavated as in the conventional method. This eliminates the need for excavation to correct the finishing of parts.

Also, on the inner surface of the grab 2, there is an opening 12 near the excavation part by the claw blade.
A air lift suction pipe 12 is provided and connected to the air lift hose 13. In other words, the opening 12a, which is the air lift suction port, is provided at the part of the grab bucket where excavation is performed, so the claw blade 8 of the grab 2 Remove the excavated earth and sand directly from its location! It can be quickly and rationally discharged by airlift together with the stabilizing liquid, and has extremely high soil discharge efficiency.
Prevents the formation of slime, facilitates the removal of precipitated slime, that is, roughing the bottom, and stabilizes the excavated wall surface by preventing behavior phenomena such as scouring and skin falling of the excavated wall surface due to the flow of stabilizing liquid and earth and sand. It can be maintained and has a significant effect.

Also, when removing soil with an air lift, it is desirable to be able to eject stones that happen to have a larger diameter than the air lift suction pipe 12, but in such a case, it is necessary to grasp them with the two grab packets on the left and right.
Since the grab bucket can be lifted and discharged, it is possible to excavate into the ground having cobblestones and boulders.

In addition, the pillar is driven vertically into the ground, the upper end of the pillar is held vertically by ground facilities, and the lower end is fixed to the ground in the hard geological layer. By adopting a method in which the grab bucket of the invention is mounted so as to be slidable up and down and excavation is performed by lowering and operating the grab bucket, it is possible to stably excavate underground continuous walls with a high degree of vertical accuracy.

[Brief explanation of the drawing]

The drawings show one embodiment of the grab bucket of the present invention, and FIG. 1 is a partially longitudinal front view showing the state during excavation, and FIG. 2 is an internal side view of the main part of the grab. 1... Frame, 2... Grab, 3... Axis, 4
...Lifting frame, 5...Operation cylinder, 6...Rod, 7...Claw bar, 8...Claw blade, 9...Pivot, 10
...Cylinder, 11...Piston rod, 12...
Air lift suction pipe, 12a... opening, 13... air lift hose, 14... telescopic 7" contact ffl pipe,
15...Air hose, 16...Wire rope, 17
...Advance polling, 18...Drilling hole, 19...
Earth, P...trajectory.

Claims (1)

[Claims] 1 A cylinder 10 in which a claw rod 7 having a plurality of claw blades 8 in a comb-teeth shape is pivotally mounted on the inner surface of the glove 2 at the tips of the left and right gloves 2 which are pivotally mounted to the lower part of the frame 1 by a glove opening/closing mechanism so as to be freely openable and closable. This grab bucket for excavating an underground continuous wall is provided with an air lift suction pipe 12 having an opening 12a near the excavation part by the claw blade on the inner surface of the grab 2, and connected to an air lift hose 13.