JP2007146514A - Digger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digger which improves construction efficiency by preventing clogging with gravel. <P>SOLUTION: The digger 1 is fitted to the front end of a rod 11, and is suspended in the earth for drilling work. A fixed pipe 12 for reverse circulation is fixed to the front end of the rod 11, and hydraulic motors 2, 2, which rotates a bit 3, are disposed on both sides of the fixed pipe 12. Earth and sand dug up by the rotation of the bit 3 is sucked together with dug mud water into the front end entrance of the fixed pipe 12, and is sent out onto the ground by an underwater sand pump 4, which is driven by a hydraulic motor 40, as shown by an arrow in the drawing. The digger 1 includes a fixed teeth 51 which are spaced at proper intervals and are fixed to the inner surface of the front end of the fixed pipe 12, and crushing teeth 52 which extend from the base of the bit 3 to the inside of the fixed pipe 12 and circle along the inner periphery of the fixed pipe 12 as the bit 3 rotates. Gravel is crushed by the fixed teeth 51 and crushing teeth 52, and is sent out onto the ground smoothly. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a reverse circulation excavator that can be installed in a narrow construction site, has a large excavable depth, regardless of the target ground.

  The foundation work and earth retaining work when adding a platform to the railway station building or expanding or reconstructing the station building should not interfere with the operation of the railway, and the construction machine should not come into contact with the power supply overhead line. Therefore, an excavator with a small ground portion is required as compared with a normal construction machine.

Japanese Patent No. 2645976 discloses a drilling hole forming excavator that is narrow and developed for such a purpose and can be applied to a construction site with a small empty head. This is a short leader mast that can be raised and lowered. A drive device provided with elevating legs by cylinders on the left and right sides is projected by projecting the lower part of the cylindrical rotary shaft downward and vertically. The gripping drum formed on the excavating shaft such as a screw auger shaft can be engaged with the inner periphery of the cylindrical rotating shaft. This excavator hangs a steel pipe or auger from above in the rotating shaft, and grips the excavating shaft with the gripping drum below the rotating shaft to perform excavation. When the excavator is lowered by one pitch, it unlocks the rotating shaft and rotates. The shaft is pushed up by the lifting leg and excavated in the form of a scale insect.
However, this excavator has a problem that the change work is complicated and takes time, and the construction period becomes long.
In addition, a reverse circulation method has been proposed in which excavated teeth are driven by a built-in electric motor, and excavated sediment is discharged by a suction pump.
Japanese Patent No. 2645976

The reverse circulation excavator for drilling is used to remove gravel when the formation target is a gravel layer, and the gravel may clog between the excavation bit and the reverse rod inlet, blocking the reverse rod. The excavation work must be stopped and the excavator must be raised to the ground to remove clogged gravel, which also reduces the construction efficiency.
Also, in the case of reverse circulation with a suction pump, the lift cannot exceed 50m, and it is difficult to excavate a deep hole. In addition, every time a reverse rod is added, a vacuum is started by the suction pump. Time is required, and this time becomes longer as the distance from the water surface to the suction pump increases, leading to a decrease in construction efficiency.
The present invention not only can be installed in a narrow site, but also improves the lifting efficiency of excavated earth and sand, expands applicable soil quality to gravel, and improves construction efficiency by preventing gravel from clogging the reverse rod. is there.

A crushing protrusion and a crushing tooth rotating inside the reverse rod together with a rotary excavating blade are provided on the inner surface of the tip of the reverse rod of the reverse circulation excavator to crush the gravel at the reverse rod entrance to prevent clogging of the reverse rod However, it enables excavation of gravel.
Furthermore, the reverse circulation is performed by a hydraulically driven sand pump, so that the lift is improved and the gravelly soil ground can be excavated efficiently.
A drive unit such as a hydraulic motor is provided on the upper part of the bit, and the hydraulic unit is installed on the ground and the excavator body is made compact so that construction can be easily performed.

According to the present invention, when a foundation hole is formed in a low sky head site in a station building or railroad track, the equipment on the ground is compact, low dredging is installed, and a large area is also required for disposal of excavated soil Therefore, it is possible to perform construction quickly without interfering with train operation.
Since the gravel crushing device is provided at the tip of the reverse rod, clogging of the gravel is prevented and construction efficiency can be improved. Therefore, the construction period can be shortened and the construction cost can be reduced.
A driving device such as a hydraulic motor is provided on the upper part of the bit, and power is efficiently used for excavation by bringing the driving source close to the bit. In addition, by installing a hydraulic unit on the ground and making the excavator main body compact, construction on a narrow site can be easily performed.

Example 1
As shown in FIGS. 1 and 2, the excavator 1 is attached to the tip of a rod 11 and suspended from the ground for excavation. A fixed pipe 12 used for reverse circulation is attached to the tip of the rod 11. The hydraulic motors 2 and 2 are installed on both sides of the fixed pipe 12. The rotational force of the hydraulic motor 2 is transmitted to the bit 3 rotatably attached to the fixed pipe 12 via a gear in the gear box 20, and a driving device is provided on the upper part of the bit, so that it is compact. It is summarized.

The type of the bit 3 is selected according to the geology to be excavated, and this embodiment is a wing bit extending in three directions. The earth and sand excavated by the rotation of the bit 3 is sucked together with the excavated mud from the front end inlet of the fixed pipe 12 and sent out to the ground as shown by the arrow in the figure by the submersible sand pump 4 driven by the hydraulic motor 40.
The hydraulic motor 2, the gear box 20, and the submersible sand pump 4 are accommodated in a housing.

  As shown in FIG. 3, a crushing device 5 for crushing gravel and the like is provided at the tip of the fixed pipe 12. The crushing device 5 extends to the inside of the fixed pipe 12 from the base of the bit 3 and the fixed teeth 51 fixed to the inner surface of the fixed pipe 12 at an appropriate interval, and turns around the inner periphery of the fixed pipe 12 as the bit 3 rotates. Since the gravel and the like sucked into the fixed pipe 12 by the fixed teeth 51 and the crushed teeth 52 are finely crushed by the fixed teeth 51 and the crushed teeth 52, they are smoothly sent to the ground without being clogged as in the prior art.

  As another shape of the bit 3, as shown in FIG. 4 (1), a three-axis bit that rotates about a fixed pipe 12 suitable for excavation of a gravel layer and that each shaft freely rotates, or FIG. 4 (2). There are three-axis bits, etc., where each axis suitable for excavation of the gravel layer and hard layer shown is driven by a hydraulic motor. The cutting motion of the bit in FIG. 4 (1) is an inner trochoid curve, and each bit rotates due to the resistance difference between the inner and outer circumferences due to the revolution movement. The cutting motion of the bit in FIG. 4 (2) is an epitrochoid curve, and each bit revolves while rotating independently.

On the ground side, as shown in FIG. 5, a hydraulic unit 6 that supplies hydraulic pressure to the excavator and a reader 7 that holds the excavator 1 and moves it up and down and takes rotational reaction force are installed. The leader 7 is a relatively short one having a height of about 3 m, and can be used even at a construction site where the sky head is low.
The excavated sediment is sent to the ground through the reverse rod 13, the vent pipe 14, and the hose 15 by the sand pump 4, and the excavated sediment is separated into water, sediment and gravel by the mud screen 8, and disposed. The separated water is returned to the circulation tank 9, adjusted, returned to the excavation hole by the suction pump 90, and circulated.

6 and 7 show a construction example in the case of constructing a foundation hole or the like between a station platform or a railway track.
In the example of FIG. 6, the excavator 1 is installed by excavating the ground surface under the platform to form a pit, and the obstacles installed in the platform during construction are made as small as possible so as not to disturb the user. It is a thing.
In the example of FIG. 7, a pit is formed between tracks, a casing is installed as a stand pipe in the pit on the bottom of the pit, and an excavator 1 is installed in the stand pipe for excavation. The construction efficiency is increased without causing an obstacle. By using a tiltable type reader, the reader is prevented from coming into contact with an overhead wire or the like during loading.

The front view of the excavator of this invention. The front view of the state which set the excavator of this invention to the leader. Detailed sectional drawing of a crushing apparatus. Explanatory drawing of the kind of bit. The conceptual diagram of the construction system using the excavator of this invention. The conceptual diagram which shows the specific example of excavation in a station building. The conceptual diagram of the example which excavates between tracks.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Excavator 12 Fixed pipe 2 Hydraulic motor 3 Bit 4 Underwater sand pump 5 Crushing device 51 Fixed tooth 52 Crushing tooth

Claims (3)

In the reverse circulation excavator, a crushing device is provided at the tip, and this crushing device rotates with a fixed tooth fixed at an appropriate interval to the inner surface of the tip of the fixed pipe for reverse circulation and the fixed pipe as an axis. A reverse-circulation excavator that consists of crushing teeth that extend from the base of the bit to the inside of the fixed pipe and swivel in the fixed pipe as the bit rotates. The reverse circulation excavator according to claim 1, wherein the reverse circulation is performed by an underwater sand pump. The reverse circulation excavator according to claim 1, wherein a driving device is provided on an upper portion of the bit.

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