JPS6149474B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an open shield excavator.

The open shield construction method, in which steel sheet piles called blades are slidably attached to both sides of the frame body, the blades are used to prevent the walls from collapsing while excavating the excavation, and burying humid pipes, etc. behind the blades is particularly useful in urban areas. Widely adopted.

Recently, with the spread of water supply and sewage systems, construction work has become increasingly necessary on narrow roads, and there are cases where construction work has to pass just under the ridges of private houses.However, with conventional equipment, the excess excavation on both sides is relatively wide. It was difficult to respond to such demands.

The present invention has been made to improve these drawbacks, and an object of the present invention is to provide an open shield excavator that can construct a structure to be buried with a minimum of extra digging.

Next, the structure of an embodiment will be explained.

<1> Front frame 1 is a front frame assembled from a plurality of columns 11 and beams 12, and has a structure substantially similar to the front frame of a known blade shield excavator.

However, in the excavator of the present invention, only this front frame 1 exists, and unlike other conventional excavators, there is no rear frame.

Propulsion jacks 3 are provided horizontally on both sides of the front frame 1 in accordance with the number of blades 2 to be described later.

The width of this front frame 1, that is, the width in the direction perpendicular to the propulsion direction, only needs to be slightly larger than the width of the box culvert to be constructed, and as a result, there is almost no need for extra digging to the side during excavation. There will be no.

<2> Blade The blade 2 is a steel sheet pile that is slidably attached to both sides of the front frame 1, and is divided into an appropriate number of sheets in consideration of the earth pressure, the thrust of the propulsion jack 3, and the weight of the front frame 1, etc. be.

A propulsion jack 3 is present between each blade 2 and the front frame 1, and the expansion and contraction of the propulsion jack 3 causes the blade 2 to be press-fitted into the face, or the front frame 1 to move forward.

The difference between this blade 2 and conventional blades is that a sliding member is provided on the inner surface near the tail end of the blade 2 to allow the structure to slide.

As a sliding member, for example, in the embodiment, vertical shaft rollers 21 are provided that project somewhat inward from the inner surface of the blade 2, and the vertical shaft rollers 2 on both sides
The space between the inner surfaces of box culvert 1 is constructed so as to approximately match the outer width of the box culvert to be constructed.

Next, the operation will be explained.

A reaction force is applied to the earth pressure on the outer circumferential surface of the blade group, and a small number of blades 2 are sequentially press-fitted into the face, and when all the blades 2 have been press-fitted, the total earth pressure on the outer circumferential surface is used as a reaction force to press the front frame 1. The operation of advancing the is similar to conventional devices.

At this time, the excavator of the present invention does not have a rear frame, and instead, the vertical axis roller 21 near the tail end of the blade 2 is in contact with both sides of the box culvert 4 that has been buried, and the reaction force of the roller 21 is in contact with both sides of the box culvert 4. This reliably prevents the tail end from deflecting inward due to earth pressure.

The front frame 1 and blade 4 group are moved forward until there is a gap between the buried culvert 4 and the front frame 1 to install a new culvert 4, but even when the front frame 1 etc. is sufficiently advanced, the vertical axis The roller 21 must be installed at a position where it will not come off the front end of the existing culvert 4.

If a new culvert 4' is buried, the front frame 1,
As the blade 2 moves forward, the vertical shaft roller 21 moves onto the side surface of the newly installed culvert 4' and supports the earth pressure from the side.

Note that the vertical shaft roller installed near the tail end of the blade is not necessarily limited to the shape shown in the figure; it may also be a rotating body such as a steel ball, or a material with a low friction coefficient such as Teflon that is simply protruded into a curved shape. alone can achieve that goal.

In short, any sliding member that comes into sliding contact with the side surface of the structure may be used.

As described above, the present invention provides a sliding member such as a roller inside near the tail end of the blade that is slidably attached to both sides of the front frame, and the interval between the sliding members on both sides is set approximately equal to the maximum width of the structure. It is composed of

Therefore, there is almost no need for excess excavation on both sides of the structure, and as a result, it is possible to bury pipes, corrugates, culverts, etc. as wide as the road, even on narrow roads crowded with private houses.

Furthermore, since the device of the present invention does not have a rear frame,
There are no obstacles behind the excavator, and the space is completely open to the rear.

Therefore, when suspending structures such as box culverts from the sky, the work can be done easily and quickly without having to worry about obstacles like in the past.

However, since there is no rear frame, the rear parts of the blades on both sides will collapse inward due to earth pressure.

Therefore, in the device of the present invention, the rear inner side of the blade can be slid on the structure, thereby ensuring sufficient force to resist earth pressure from the inside.

That is, the device of the present invention is the first to solve the conventionally contradictory requirements of securing sufficient space at the rear and supporting the blade from the inside.

[Brief explanation of the drawing]

FIG. 1: An explanatory diagram of an embodiment of the open shield excavator according to the present invention, seen from the side. Figure 2: An explanatory diagram seen from above. Figure 3: An explanatory diagram seen from the front and back. 2: Blade, 21: Vertical axis roller.

Claims (1)

[Claims] 1. A plurality of horizontally divided blades are slidably attached to the side of the frame body, and the frame body and blades are alternately advanced by taking a reaction force to the surrounding earth pressure applied to the blades. In the blade shield excavator, a sliding member is provided inside the vicinity of the tail end of each blade, and the interval between the sliding members on both sides is configured to be approximately equal to the maximum width of the structure to be constructed, An open shield excavator configured to move forward by sliding the sliding member of the blade on the side of the structure.