JPH0437963Y2 - - Google Patents

Description

[Detailed description of the invention] <<Industrial Application Field>> This invention relates to an excavator suitable for constructing underground walls at great depths.

<<Prior Art>> As an excavator for excavating an excavation hole for constructing an underground wall, conventional excavators include a guide bar type excavator equipped with a guide bar that guides the excavator body along the excavation hole; There are two types of excavators: a suspended type excavator that feeds into the borehole while suspending the excavator body with a wire.

The former structure allows for highly accurate excavation work, but when excavating deep underground walls, the length of the guide bar becomes longer, making the equipment larger.

On the other hand, with the latter structure, it can be used at great depths simply by feeding out the wire, so the equipment does not need to be large-sized. cannot be applied.

《Problems to be solved by the invention》 By the way, when excavating an underground wall at great depth, when using the underground wall as a retaining wall for the main body, for example, the upper part of the root to be cut must be excavated with high accuracy. The lower part of the embedding part does not require very high precision.

Therefore, if you use a guide bar type excavator to excavate the upper part of the root to be cut, and a suspended excavator to excavate the lower part, appropriate accuracy can be achieved without increasing the size of the machine. excavation work can be carried out.

However, in this case, two types of excavators must be used alternately depending on the depth, and replacement, installation, and positioning work in the vicinity of the excavation hole is troublesome.

In addition, if the position shifts during replacement, the precision that has been maintained is greatly shifted, and
There was a risk that it would fall outside the allowable error range.

This invention solves the above problems, and its purpose is to incorporate both the advantages of the guide bar type and the advantages of the suspension type, and to construct deep underground walls without increasing the size. The purpose of the present invention is to provide an excavator that can meet the required excavation accuracy for.

<<Means for Solving the Problems>> In order to achieve the above object, this invention includes a guide bar suspended from the tip of the crane, and an intermediate member that is guided and supported by the guide bar and is retractable downward from the guide bar. a bar, a first stopper that restricts the re-protruding position of the intermediate bar, a Kelly bar that is guided and supported by the intermediate bar and is retractable downward from the intermediate bar, and an excavator that is supported and fixed to the lower end of the Kelly bar. The machine body, a hanging wire whose one end is connected to the Kelly bar and whose other end is connected to a take-up winch provided on the crane side through the intermediate bar and the guide bar, and the It is characterized by comprising a wire steadying guide box disposed within the intermediate bar and movable up and down along the wire, and a second stopper for restricting the guide box from protruding from the lower part of the intermediate bar. do.

<<Operation>> At the upper side of the excavation hole, the Kelly bar holding the excavator main body at its tip is pulled into the guide bar together with the intermediate bar by feeding out the wire, and is guided and supported by the guide bar and lowered.

After the intermediate bar moves to the bottom of the guide bar,
When the wire is further fed out, the Kelly bar is suspended from the wire and descends to the depths.

Therefore, if the length of the guide bar is set in accordance with the depth at the upper side of the excavation hole, that is, at the location where the underground wall is constructed, the excavation hole can be accurately excavated according to the guidance of the guide bar. . During the subsequent deep excavation, the excavator body is suspended and held by a wire.
Since the middle part of the wire is held in position with respect to the middle bar by the guide box, the excavation accuracy decreases, but since this part is the embedding part, it is within the tolerance range and causes a practical problem. Never.

<<Example>> Hereinafter, an example of this invention will be described in detail using the drawings.

In FIGS. 1 to 4, an excavator 3 is disposed near an excavated hole 2 for constructing an underground wall whose top end is partitioned by a guide wall 1.

The excavator 3 includes a base machine 4 installed on the ground surface, a crane 5 rotatably supported by the base machine 4, and an internal hollow guide bar 6 suspended from the top end of the crane 5. An excavator main body 7 protrudes from the lower end of the guide bar 6, and a support stay 8 for angle adjustment whose one end is supported by the base machine 4 and the other end is pivotally connected to the lower end of the guide bar 6.
It is equipped with

Inside the guide bar 6 is an intermediate bar 9 which is also hollow inside, and inside thereof is the excavator main body 7.
A Kelly bar 10 having a fixed end thereof is inserted therethrough.

A plurality of hanging wires 11 are inserted into the inside of the Kelly bar 10, one of which is connected to the side surface of the Kelly bar 10, and the other one is connected to the excavator body 7.

The other end of the wire 11 is connected to a take-up winch (not shown) provided on the base machine side through an intermediate drum 12 rotatably supported on the uppermost end of the crane through the intermediate bar 9 and guide bar 6. are doing.

Further, on the upper side of the Kelly bar 10, a guide box 13 is inserted into the intermediate bar 9, and each of the wires 11 is inserted through the guide box 13 to prevent the wires 11 from twisting in a suspended state. ing.

A first stopper 6a is arranged on the inner periphery of the lowermost end of the guide bar 6, and a flange 9a that engages with the first stopper 6a is provided on the outer periphery of the uppermost part of the intermediate bar 9. At the lowest position of the intermediate bar 9, this flange 9a engages with the first stopper 6a, thereby restricting the intermediate bar 9 from being pulled out.

A second stopper 9b is provided on the inner periphery of the lowermost end of the intermediate bar 9 to prevent the guide box 13 from protruding from the intermediate bar 9.

In the above configuration, when the wire 11 is wound up by the winding winch, as shown in FIG. The shoulder portion 7 is in contact with the tip of the guide bar 6 and protrudes from the lower end of the guide bar 6.

When the wire 11 is fed out from this state, both the intermediate bar 9 and the Kelly bar 10 are lowered, and the tip of the excavator body 7 is supplied into the excavation hole 2 surrounded by the guide wall 1, and in this state, the excavator body By driving the drill hole 7, the excavation hole 2 is excavated.

As the excavation work progresses, as shown in FIG. 2, when the intermediate bar 9 descends to the lowest position, its upper end flange 9a engages with the first stopper 6a, stopping the descent.

Meanwhile, the Kelly bar 10 continues to descend using the intermediate bar 9 as a guide, and the excavation work continues as shown in FIG. Therefore, in the initial stage of excavation work, excavation is performed while descending using the guide bar 6 and intermediate bar 9 as guides, respectively.
Excavation accuracy is obtained in accordance with the installation accuracy of the guide bar 6 and the processing accuracy of each bar 6 and 9.

As shown in FIG. 4, when the Kelly bar 10 is completely pulled out from the lower part of the intermediate bar 9, the guide box 13 comes into contact with the second stopper part 9b provided on the inner periphery of the lower part of the intermediate bar 9. fixedly supported on the part.

Note that if the excavator body 7 is suspended only by the wire 11, vibration will occur and the excavator main body 7 at the tip will be shaken, but by inserting and guiding the wire 11 through the guide box 13,
This type of vibration is prevented as much as possible, and the Kelly bar 10 is designed to descend in accordance with the excavation work of the excavator main body 7 while maintaining almost verticality.

However, even with this kind of device, the excavation accuracy is lower than that in the stage where the guide bar 6 and the intermediate bar 9 are used as described above. , is within the tolerance range and does not cause any practical problems.

When the drilling work has been completed to the deepest part of the planned drilling hole 2, the wire 11 is wound up, the Kelly bar 10 is pulled up into the intermediate bar 9, and then the intermediate bar 9 is also pulled up into the guide bar 6, and the original is in a standby state.

<<Effects>> As explained in detail using the embodiments above, in the underground wall excavator according to this invention, the Kelly bar, which holds the excavator main body at the tip, is attached together with the intermediate bar on the upper side of the excavation hole. The kelly bar moves downward along the guide bar while being retracted into the guide bar, and when the intermediate bar has completed its movement to the bottom of the guide bar, only the kelly bar moves the excavator body by letting out the wire. It is designed to descend further into the depths while being driven. the upper side of the drilling hole,
That is, by setting the length of the guide bar in accordance with the depth at the underground wall construction position, the excavation hole can be excavated with high precision according to the guidance of the guide bar. The accuracy of subsequent deep excavation will be reduced, but the guide box prevents the wire from twisting, and since this part is a rooting part, it is within the tolerance range and does not cause any practical problems. .

Therefore, with this invention, there is no need to increase the size of equipment when constructing deep underground walls, which is a disadvantage of the guide bar type, and moreover, it is possible to eliminate the need for large-sized equipment when constructing deep underground walls, and moreover, only the minimum necessary part that requires high excavation accuracy can be used. It is possible to maintain high excavation accuracy at a certain upper underground wall construction position.

[Brief explanation of the drawing]

1 to 4 are explanatory diagrams showing each excavation stage of the excavator for constructing underground walls according to this invention. 3... Excavator, 4... Base machine, 5... Crane, 6... Guide bar, 6a... First stopper, 7... Excavator main body, 9... Intermediate bar, 9b
...Second Stoppa, 10...Kelly Bar, 11
...wire, 13...guide box.

Claims (1)

[Scope of utility model registration request] a guide bar suspended from the tip of the crane; an intermediate bar that is guided and supported by the guide bar and can extend and retract downward from the guide bar; a first stopper that restricts the most protruding position of the intermediate bar; a kelly bar that is guided and supported by an intermediate bar and can extend and retract downward from the intermediate bar; an excavator main body that is supported and fixed to the lower end of the kelly bar; one end is connected to the kelly bar and the other end is connected to the intermediate bar and the guide bar. a hanging wire connected to a take-up winch provided on the crane side through the interior; and a wire steadying guide that is disposed within the intermediate bar with the wire inserted therethrough and is movable up and down along the wire. An excavator for constructing an underground wall, comprising a box and a second stopper that restricts the guide box from protruding from the lower part of the intermediate bar.