JPH03281834A - Method and apparatus for preceding excavation of clamshell bucket - Google Patents

Abstract

PURPOSE:To raise the efficiency of operation by a method in which an excavator with two augers is detachably set on the tip of a clamshell bucket positioned on a Kelly excavator, and a pilot hole is formed to enable it to grasp by the use of the bucket. CONSTITUTION:A preceding excavator 14 with two augers 18 and 20 is detachably set on the tip of a clamshell bucket 12 set on a Kelly excavator. Two pilot holes are dug in the ground to enable them to grasp by the bucket 12 in such a way as to make excavation of even hard ground possible. The efficiency of excavating operation can thus be raised.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a clamshell bucket advance excavation method and device for excavating a continuous underground wall, and in particular to a clamshell excavation method for excavating hard strata with a clamshell bucket. The present invention relates to a bucket advance excavation method and its device.

[Conventional technology]

Clamshell buckets are often used for continuous wall excavation because they are easy to dispose of, but their lack of cutting ability reduces efficiency and makes it difficult to excavate hard strata such as clay.

Conventionally, when excavating hard strata with a Kelly excavator equipped with a clamshell bucket, the clamshell bucket was dropped, the shell cutting edge was embedded in the hard ground, and then the clamshell bucket was closed to grasp the ground and excavate.

[Problem to be solved by the invention]

However, in the case of hard strata, the amount of penetration of the shell cutting edge decreases, so in order to increase the penetration amount, the shell cutting edge is chopped, but it is difficult to grab the earth and sand just by penetrating the cutting edge. Therefore, there is a problem of poor excavation efficiency.

The present invention has been made in view of the above circumstances, and provides a clamshell bucket advance excavation method and device that enables excavation of hard strata using a clamshell bucket without reducing excavation efficiency. The purpose is to

[Means to solve problems]

In order to achieve the above object, the present invention uses a clamshell bucket to sandwich a leading excavation device in a hard stratum that is difficult to excavate with just a clamshell bucket, and uses the advance drilling device to vertically drill two holes at both ends of a trench width. Pre-drill to open a pilot hole. Then, on the ground, the clamping of the excavation equipment by the clamshell bucket is released, and the clam/el packet is inserted again, and the tip of the packet is penetrated and closed using the two holes as pilot holes to grasp the earth and sand inside and excavate. The method is characterized in that the preceding excavation and excavation using a clamshell bucket are repeated as appropriate to excavate a hard stratum.

[Effect]

According to the present invention, the advance excavator, which is removably attached to the clam/el packet, is provided with a rotary excavator capable of excavating at a position corresponding to the shell cutting edge. Therefore, with a preliminary drilling rig held by a clamshell bucket, two holes are vertically drilled at a predetermined distance in the ground, a pilot hole is made so that the packet can be easily grasped, and the drilling rig is removed from the clamshell bucket. A pair of shell cutting edges were inserted into the two pilot holes so that they could be grasped with a clamshell bucket and excavated. Further, although the preceding excavator is held and suspended by a clam/L packet, the present invention is not limited to this, and a dedicated hanging machine may be used.

〔Example〕

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The clamshell bucket excavation method and apparatus thereof according to the present invention will be explained in detail below with reference to the accompanying drawings.

A Kelly excavator 10 is illustrated in FIG.

A clamshell bucket 12 is attached to the Kelly excavator 10, and a preceding excavator 1 is attached to the clamshell bucket 12.
4 is retained. As shown in FIG. 2, this advance excavator 14 has a box-shaped casing 16.
The upper end portions of augers 18 and 20 are rotatably supported at the lower end portions of the augers 18 and 20 at a predetermined interval. Auger 18.20
Cutters 22, 22, 22, . . . are provided at the lower end. In addition, the augers 18 and 20 are each equipped with a reducer 2.
4.26, it is connected to a drive shaft (not shown) of the underwater motor 28 so that rotational force can be transmitted thereto. The output shaft connected to the auger 18.20 of this reducer 24.26 is set to reverse in the direction of the arrow in and the direction of the arrow B in FIG. 2, so the auger 18.20 also The incoming direction and the direction of arrow B are reversed. Two underwater motors 28 may be provided and each auger may be driven independently.

A protrusion 30 is fixed to the upper end of the casing 16, and an overhang 32 extends from the upper end. This overhang 32 is held between the cutting edges 38 and 40 of the clamshell bucket 12. This cutting edge 38.40 is connected to a pair of packets 36.3 which are rotatably supported via pins 34.34.
It is fixed to 6. The lead excavator 14 is thus held at the lower end of the clamshell bucket 12 when clamped by the cutting edges 38,40.

In Figure 1, IOA is the Kelly excavator, 10B is the boom, and 44 is 3J in Figure 2! Outlet box for 1 electricity, 46 is an accumulator for pressure balance,
48 is a guide.

The operation of the clamshell bucket excavating device according to the present invention configured as described above! ! Hustle.

First, cylinder 50.52 of clamshell bucket 12
The packet 35, 36 is rotated around the pin 34, 34, and the shell cutting edge 38, 40 holds the overhang 32 on the casing 16, and the ram shell packet 12 holds the leading excavator 14. .

Next, the power cable 11 is led from the ground and drives the underwater motor 28 via the outlet box 44. When the underwater motor 28 is driven, its rotating force is transferred to the reducer 24.26
to the auger 18.20 through the auger 18.2
0 rotates in the arrow in direction and arrow B direction in FIG. 2, respectively.

Next, the clamshell bucket 12 is lowered and the third clamshell bucket 12 is lowered.
As shown in Figures (A) and (C), holes 54 and 56 are bored in the hard stratum using an auger 18 and 20 to loosen the hard stratum. After drilling the hole 54.56, the clamshell 12 is moved upward to extract the auger 18.20 from the hole 54.56, and after recovering it to the ground, the cylinder 50.52 is actuated to remove the holding portion by the shell cutting edge 38.40. 32 is released.

Next, the cutting edge 38.40 of the packet 35.36 is opened to a point W shown by the two-dot chain line in FIG.
8.Put it into holes 54 and 56 drilled in 20th. Cylinder 50.52 is then actuated to release packet 35.36.
At the same time, the blade edges 38 and 40 are closed to observe the hard ground 58 shown in FIGS. 3 (Δ) and (C), and the tool ascends as it is to discharge the grabbed ground. As a result, Figure 3 (B)
A hole 60 as shown in is drilled.

The above-described method is then sequentially repeated to drill a hole to a desired depth in the hard stratum.

In the embodiment described above, the auger 18.
20 is rotatably provided, but the present invention is not limited to this, and other rotary excavating means may be provided. Further, since the advance excavation device is a means for partially excavating a hard layer and can be used only for a short time, the power source may be equipped with a rechargeable battery.

In this case, a power cable is not required, and operability and maneuverability are increased.

〔Effect of the invention〕

According to the clamshell bucket excavation method and its device according to the present invention, before excavating with the clamshell bucket, the portion where the shell cutting edge of the clamshell bucket sinks into the ground can be previously excavated with the advance excavation device. Therefore, the tip of the clamshell bucket can be completely penetrated, and the efficiency of gripping excavation using the clamshell bucket can be improved.

Further, since the advance excavation device according to the present invention can be used by being held in the packet of an existing clamshell bucket excavator, it is possible to improve work efficiency at low cost.

[Brief explanation of drawings]

Fig. 1 is a side view showing a state in which the advance excavation device according to the present invention is attached to a clamshell bucket of a Kelly excavator;
The figure is an enlarged view of the advance excavator according to the present invention, FIG. 3(A) is a sectional view showing a state in which a hole is excavated by the advance excavator according to the present invention, and FIG. 3(B) is an enlarged view of the advance excavator according to the present invention. A cross-sectional view showing a state in which a clamshell bucket is used to grab and excavate after drilling a hole in advance with a drilling rig, and Figure 3 (C) is taken from A-A in Figure 3 (A).
It is an arrow view. 10--Kelly excavator, 2--clamshell bucket 4--preceding excavation device, 8.20--auger, 8--ice motor, 2--holding part, 0.52-- ·Cylinder. 16...Caning, 24.26...Reducer, 30...Protrusion, 38.40...Blade tip,

Claims (2)

[Claims] (1) Hold the advance drilling equipment with a clamshell bucket,
Pre-drill two holes vertically at a predetermined distance in the ground using the advance drilling device, release the clamshell bucket from holding the drilling device, and use the clamshell bucket to grab the two holes as pilot holes and drill. A method for advance excavation of a clamshell bucket, characterized in that the advance excavation and the excavation with the clamshell bucket are repeated. (2) An excavator having a clamshell bucket, a casing provided with a portion that can be held by the clamshell bucket, and an excavating means rotatably provided at a predetermined interval in the vertical direction at the lower end of the casing. 1. A preceding excavating device for a clamshell bucket, comprising: a pre-excavating device provided in a casing, and a driving means for driving an excavating means.