JPH10176477A - Shaft excavator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out accurate and stabilized execution of work for excavation of a shaft in a large diameter for burying a caisson at a great depth. SOLUTION: An excavator 14 is composed of an excavator main body 40, a bit 42 provided at the excavator main body 40, a submerged pump 46 and grip jacks 44. And the excavator is held at the front end of a caisson 16 with the grip jacks 44 pressed against the internal wall of the caisson 16. Excavation is made with the bit 42 being rotated, and excavated earth is discharged to the surface of the ground with the submerged pump 46. Projectable and retractable over cutters 54 are provided at the periphery at the front end of the bit 42, and widened excavation can be executed with the amount of projection adjusted for the over cutters 54.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a shaft excavator,
In particular, the present invention relates to a shaft excavator for excavating a shaft having a large hole diameter and a large depth with high accuracy.

[0002]

2. Description of the Related Art As a conventional shaft excavation method, there is an all casing type reverse circulation drill method (all casing type RCD method) disclosed in Japanese Patent Publication No. 46608/1986. This excavation method excavates a shaft by the following method. First, a casing pipe is erected at the site to be excavated, and the casing pipe is supported by jacks. Next, a drill pipe equipped with a rotary drilling tool and an underwater discharging pump is inserted and installed in the casing pipe. Then, the drill pipe is connected to a drill driving device supported on the upper end of the casing pipe. Thereafter, the excavation driving device and the underwater discharge pump are driven to excavate and discharge the lower end of the casing, and at the same time, the jack is driven to integrally connect the casing pipe and the excavation driving device. And excavate the shaft.

[0003]

However, in the conventional all-casing type RCD method described above, the rotary driving of the rotary drilling tool is performed by the drilling drive device supported on the upper end of the casing pipe. Depth (5m
When digging a shaft of about 20 m), a large torque is required, and a strong drill pipe is required. For this reason, there is a disadvantage that the weight increases and the cost increases.

There is also a disadvantage that the excavated soil cannot be accumulated at the discharge port of the submerged discharge pump due to the increase in the diameter of the drill hole. Furthermore, since the diameter of the rotary excavator is constant, widening excavation cannot be performed freely.
In addition, since the driving device is on the ground, a special power transmission line is required, the device becomes complicated, and the excavation work becomes complicated.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a shaft excavator capable of accurately and stably excavating a shaft having a large diameter and a large depth with a simple configuration. Aim.

[0006]

According to the present invention, in order to achieve the above object, an excavator is installed at the tip of a caisson, and the caisson is press-fitted while excavating the lower ground of the caisson with the excavator. In a shaft excavator for excavating a shaft at a predetermined depth, the excavator is provided on the excavator body and the excavator body, and holds an inner wall of the caisson to hold the excavator body in the caisson. Means, a bit rotatably attached to the tip of the excavator body,
A driving unit for rotating the bit, an overcutter provided on the outer periphery of the bit, and an overcutter provided to be able to protrude and retract from the outer periphery of the bit, a moving unit for moving the overcutter, and mounted on the excavator body, A submersible pump for discharging excavated earth and sand.

According to the present invention, the excavator body is held by pressing the inner wall of the caisson with the holding means. Therefore, since the excavation reaction force is held by the holding means, the pipe is light as it is sufficient to hold the weight of the excavator. This also simplifies the ground equipment. In addition, by moving the over cutter, the diameter of the bit can be freely increased and decreased, thereby making it possible to easily perform widening excavation.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a shaft excavator according to the present invention will be described below in detail with reference to the accompanying drawings. FIG.
It is a side view showing composition of an embodiment of a shaft excavator concerning the present invention. As shown in FIG.
The excavator 14 excavates the shaft 12, a press-fitting device 18 for press-fitting a caisson 16, and a tower 20 for suspending the excavator 14.

The tower 20 is installed on a pressure girder 23 of a press-fitting device 18 installed on a guide wall 22.
, Are fixed by earth anchors 27, 27. At the top of the tower 20, a power sheave 2
6 are provided. A running block 30 is suspended from the power sheave 26 via a wire rope 28, and a bend joint 33 that supports a reverse pipe 32 is suspended from the running block 30. A holder 3 for holding the reverse pipe 32 is provided on the base 21 of the tower 20.
4 are installed.

The reverse pipe 32 supported by the bend joint 33 is connected to a case 47 of a submersible pump 46 mounted on the excavator 14, and the excavator 14 is suspended by the reverse pipe.
The wire rope 28 is connected to a hoisting device (not shown), and by driving the hoisting device,
The running block 30 can be raised and lowered.

The press-fitting device 18 is provided at a lower portion of the tower 20, and is composed of a plurality of main push jacks 36, 36,. The main push jacks 36, 36,... Are arranged at equal intervals on the same circumference.
When the upper end is pressed, the leading edge 7
Pressed into the ground from 4.

The caisson 16 is formed in a cylindrical shape by stacking a large number of segments 16a, 16a,... Formed in an arc shape. Note that this segment 16
The a, 16a,... are stored by the automatic segment storage device 38 provided in the tower 20. As shown in FIGS. 2 and 3, the excavator 14 includes an excavator body 40, a bit 42, a grip jack 44, and a submersible pump 46 as main components.

The excavator body 40 is formed in a disk shape, and a spindle 48 is rotatably supported on the center coaxially via a bearing. This spindle 4
A flange 50 of the bit 42 is connected to a tip of the 8. The bit 42 includes four inner blades 42A, 42A,... Disposed at the center of the flange 50, and eight outer blades 42B, 42B,. I have. A number of excavating teeth 52 are fixed to the cutting edges of the inner wing 42A and the outer wing 42B, and the ground is excavated by the excavating teeth 52, 52,.

The inner wing 42 constituting the bit 42
The A and the outer wing 42B are each formed in, for example, a substantially arc shape, and are arranged so as to form a spiral as a whole as shown in FIG. As a result, the drilling teeth 52, 52,
The excavated earth and sand excavated at the inner wing 42A and the outer wing 42
B rotates, each inner wing 42A or outer wing 42B
And is raked up at the center of the bit 42.

At the outer peripheral portion of each of the outer blades 42B, overcutters 54, 54,... Having cutting edges 52 fixed to the cutting edges are provided. The overcutter 54 is guided by a guide member (not shown) of the outer wing 42B so as to be able to protrude and retract from the outer periphery of the outer wing 42B, 42B,..., And hydraulic cylinders 56, 56 connected to the base end thereof. ,.. Are driven to change the position.

As a result, the outer diameter of the bit 42 can be varied by adjusting the amount of movement of the overcutters 54, 54,..., Whereby the widening excavation can be freely performed. become. The pressure oil for driving the hydraulic cylinders 56 is supplied from a hydraulic unit (not shown) mounted on the excavator body 40 via a swivel mechanism (not shown) of the excavator body 40.

The bit 42 is driven to rotate by rotating the spindle 48. The spindle 48 is driven by the following mechanism. As shown in FIG. 2, the excavator body 40 has oil motors 58, 58 mounted thereon.
The rotation of the gears 8 and 58 is transmitted to the gear 64 fixed to the spindle 48 via the gear 60, the first reduction gear 62a and the gear 62b, and the second reduction gear 62c and the gear 62d, and the spindle 48 rotates. Thereby, the flange 5
Bit 42 rotates with 0.

The gear 60 is connected to a shaft of the oil motor 58, and the first reduction gear 6
The gear 2a and the gear 62b are fixed to a first shaft 66 rotatably supported by the excavator body 40. Also,
The second reduction gear 62c and the gear 62d are fixed to a second shaft 68 rotatably supported by the excavator body 40.

The oil motors 58 are driven by oil sent from a hydraulic hose by a hydraulic unit (not shown) installed on the ground. Note that an electric motor can be used instead of the oil motor 58.
The four grip jacks 44 are arranged at equal intervals on the outer peripheral portion of the excavator body 40. The grip jack 44 is driven by a hydraulic cylinder, and holds the excavator body 40 in the caisson 16 by pressing a reaction force receiver 70 attached to the tip of the caisson 16.

The submersible pump 46 is mounted on the excavator body 4.
0, and the excavated earth and sand excavated by the bit 42 is sucked and discharged to the ground. In the center of the lower part of the excavator body 40, a suction port 72 for the excavated earth and sand is formed, and the excavated earth and sand sucked from the suction port 72 passes through a reverse pipe 32 connected to the submersible pump 46. It is discharged to a processing plant (not shown) on the ground.

The operation of the embodiment of the shaft excavator according to the present invention configured as described above is as follows. First, the mouth of the shaft 12 is excavated at a site to be excavated using a shovel, a hammer club bucket, or the like. Then, the caisson 16 equipped with the cutting edge 74 at the tip is built in the excavated shaft 12.

Next, the shaft 1 in which the caisson 16 is built
The press-fitting device 18 and the stirrer 20 are arranged on the upper part of 2, and the excavator 14 is inserted from above the caisson 16. By operating the grip jacks 44 of the excavator 14, the pressure receiver 70
Is pressed against the inner wall of the caisson 16, the excavator body 40 is fixed in the caisson 16, and excavation is started. Excavation is performed by the reverse circulation method. That is, the hole is continuously drilled by the rotating bit 42 while the collapse of the hole wall is prevented by the hydrostatic pressure, and the excavated earth and sand is sucked together with the circulating water by the submersible pump 46 and discharged through the reverse pipe 32 to the outside of the hole.

First, the oil motors 58, 58 are driven to rotate the bit 42. At the same time, the submersible pump 46 is driven to suck the circulating water from the suction port 72. As a result, the ground is excavated by the rotating bit 42, and the excavated earth and sand is sucked from the suction port 72 together with the circulating water and discharged out of the hole. Here, as described above, the inner wing 42A and the outer wing 42B constituting the bit 42 are:
Since it is formed in a substantially arc shape and is formed in a spiral as a whole, the excavated earth and sand excavated by the bit 42 is guided by the inner wings 42A and the outer wings 42B and is accumulated in the central portion of the bit 42. . In addition, since a suction port 72 for sucking excavated earth and sand is formed in the center of the bit 42 where the excavated earth and sand are accumulated, even if the shaft is a large-diameter shaft,
Excavated soil can be discharged efficiently.

Simultaneously with this excavation, the upper end of the caisson 16 is pressed by the main push jacks 36, 36,... To press the caisson 16 into the shaft. When the caisson 16 is press-fitted, the excavator 14 held at the tip of the caisson 16 also moves at the same time, whereby the excavation proceeds. Since the bit 42 has a large hole diameter, it can correspond to each hole diameter if configured in combination.

Excavation is performed in the above steps, and when the main push jacks 36, 36,. Then, the segments 16a, 16a,
.. Are accumulated to assemble a new caisson 16, and when the new caisson 16 is assembled, the excavation work is restarted again. Hereinafter, the same operation is repeated to excavate the shaft 12 having a predetermined depth.

The widening excavation is performed by driving the hydraulic cylinder 56 as necessary to vary the amount of protrusion of the overcutter 54. That is, in order for the caisson 16 to be press-fitted stably, the original pushing jacks 36, 3
The caisson 16 pressed by 6,... Needs to be press-fitted with an appropriate load. Whether or not the caisson 16 is press-fitted with an appropriate load depends on the diameter of the drill hole drilled by the bit 42. Therefore, the diameter of the excavation hole is adjusted by changing the amount of protrusion of the over cutter 54 and changing the outer diameter of the bit 42.

For example, when a load larger than the specified load is applied to the tip of the caisson 16, the diameter of the bit 42 is increased by projecting the over cutter 54.
On the other hand, when the load applied to the tip of the caisson 16 is smaller than the specified load, the over cutter 54 is retracted to reduce the diameter of the bit 42. Thereby, the caisson 16 is press-fitted with an appropriate load, and the caisson 16 can be press-fitted accurately and stably.

The load applied to the tip of the caisson 16 is measured by a load sensor (not shown) provided at the tip of the caisson 16. Control means (not shown)
Calculates the optimum bit diameter from this measurement result and automatically adjusts the protrusion amount of the over cutter 54. Thus, according to the shaft excavator 10 of the present embodiment, a large hole diameter,
Even when the shaft is deep, the caisson 16 can be accurately and stably press-fitted.

Further, since the configuration is simple, the weight is light, and the size and simplification of the ground equipment can be achieved. In addition, the excavator 14 includes the grip jack 4
4, the excavator 14 is held in the caisson 16 and receives the excavation reaction force by the grip jack 44, so that the reverse pipe 32 has a structure that only needs to hold the weight of the excavator 14. Therefore, the ground equipment can be reduced in size and simplified.

Further, an inner wing 42A constituting the bit 42
Even when excavating a shaft with a large diameter, the outer wing 42B is formed in an arc shape, so that the excavated soil is always accumulated in the center, so that the excavated soil can be efficiently discharged. it can. In addition, by providing the overcutter 54 which can be retracted around the outer periphery of the bit 42, widening excavation can be performed freely.

[0031]

As described above, according to the present invention,
A bit rotation device was installed on the underground excavator body, and the caisson inner wall was subjected to a reaction force by a grip jack, so that a submersible pump could be mounted, and a large torque and a large load could be added. Excavation of hole diameter, large depth and hard ground is possible. In addition, the shaft can be excavated accurately and stably by the widening mechanism. Further, it is possible to reduce the weight of the device, shorten the construction period, and reduce the cost.

[Brief description of the drawings]

FIG. 1 is a side view showing a configuration of an embodiment of a shaft excavator according to the present invention.

FIG. 2 is a side view of the excavator.

FIG. 3 is a plan view of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... shaft excavator 12 ... shaft 14 ... excavator 16 ... caisson 18 ... press-in apparatus 20 ... tower 40 ... excavator body 42 ... bit 42A ... inner wing 42B ... outer wing 44 ... grip jack 46 ... submersible pump

Continuing on the front page (72) Inventor Takeshi Sakae 1-25-1, Nishi-Shinjuku, Shinjuku-ku, Tokyo Taisei Construction Co., Ltd. (72) Inventor Minoru Kaneko 1-25-1, Nishi-shinjuku, Shinjuku-ku, Tokyo Taisei Construction Co., Ltd. (72) Inventor Kenichi Kaneko 1-25-1, Nishi-Shinjuku, Shinjuku-ku, Tokyo Taisei Construction Co., Ltd. (72) Inventor Hitoshi Kitayama 11-1 Kitahama-cho, Chita-shi, Aichi Pref. Inside the Aichi Plant (72) Inventor, Yoshinari Toyama 3-1-1, Toyoshu, Koto-ku, Tokyo Ishikawajima-Harima Heavy Industries Co., Ltd. No. Toneuchi Corporation 72 Inventor Yoshifumi Mizuno 1-6-17 Meguro Meguro-ku Tokyo

Claims (1)

[Claims] 1. A shaft excavator in which an excavator is installed at the tip of a caisson, and while excavating a lower ground of the caisson, the caisson is press-fitted to excavate a shaft of a predetermined depth. An excavator main body; holding means provided on the excavator main body for pressing an inner wall of the caisson to hold the excavator main body in the caisson; rotatably attached to a tip end of the excavator main body. A driving means for rotating the bit; an overcutter provided on the outer circumference of the bit so as to be able to protrude and retract from the outer circumference of the bit; a moving means for moving the overcutter; And a submersible pump mounted on the pump for discharging excavated earth and sand.