JPH0220309Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention involves interposing a pressure bag between buried propulsion tubes, injecting fluid into the pressure bag and discharging it in an orderly manner. This is an improvement regarding the pressurized bag of a device for excavating and propelling a propulsion tube.

When constructing underground main pipes for water and sewage pipes, electrical cables, or utility tunnels, excavation is carried out horizontally from a shaft dug vertically from the ground, and at the same time, a propulsion pipe such as a Huyum pipe is excavated horizontally from a vertically lowered shaft. As one of the so-called propulsion pipe construction methods, in which the propulsion pipes are sent in sequence to form tunnels underground,
By injecting fluid such as compressed air or pressurized water into a pressurized bag mainly composed of an elastic material such as rubber, and sequentially pressurizing each propulsion tube in the axial direction of the tunnel, the entire propulsion tube is moved in the excavation direction. There is a construction method that promotes successive steps. Regarding the operation of the pressurized bag during construction of this construction method (generally referred to as the Earth Ohm method), the propulsion pipe just in front of a certain pressurized bag is moved in the axial direction of the tunnel at the same time as the pressurized bag is pressurized. When the forward movement is completed, the next propulsion tube that was previously advanced is moved forward by applying pressure to the pressurized bag located one rearward. At this time, the initially inflated pressurized bag is depressurized and compressed by pressure from the rear. By sequentially repeating operations like this, each single propulsion tube is propelled forward by excavation. Regarding this compressive force, depending on the tip of the tunnel, the frictional resistance between the propulsion pipe and the ground in front of the pressurized bag, the amount of pressurization from the rear, etc., the pressurized bag may become excessively strong. Because it is compressed, the pressurized bag becomes a completely sealed sheet with almost no internal space (see Figure 2 A), and then the pressurized fluid has no space for the next advancement. Since the flow of fluid is obstructed, the pressurizing force of the pressurized bag is significantly reduced in such a situation.

In order to prevent this failure, it is necessary to maintain the internal gap of the pressurized bag no matter how much pressure is applied from the rear.

For this reason, the present invention provides a pressurization method characterized by inserting a holding body such as a cloth or a net-like material to form a ventilation (liquid) gap on the inner surface and providing it by gluing all or part of the holding body. Regarding bags.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained in detail with reference to the drawings shown as embodiments.

FIG. 1 is a front view showing an example of a hydraulic excavation device, which has a cutter head 1 at its tip for propelling underground excavation, and as the excavation progresses, underground pipes 2a are sequentially installed 2b, 2c. , 2n.

Pressure bags are interposed in each continuous portion of the cutter head 1 or the buried pipe at appropriate intervals.
That is, between the cutter head 1 and the buried pipe 2a is a pressurized bag 4a which communicates with a fluid pipe 5a through a communication hole 3a for pressurized fluid such as pressurized air or liquid.
Similarly, the pressure bag 4b is provided with a communication hole 3b that communicates with the fluid pipe 5b, and the pressure bag 4c is provided with a communication hole 3c that communicates with the fluid pipe 5c.
When forming a set, they are connected as one pitch as shown in the figure. Note that 6 is a sliding collar and 7 is a sealing collar. The pressure bags 4a to 4c have conventionally been airtight, and have a shape such as a rubber tube, which has sufficient airtightness whether it is compressible or inflatable, and has an intermediate layer of cloth or the like for reinforcement and shape retention. belongs to.

In FIG. 1, when a pressure fluid such as compressed air or pressurized liquid is sent from the flow pipe 5a to the pressure bag 4a, the cutter head 1 is strongly pressed as the pressure bag 4a expands and is propelled to excavate. Next, the fluid pipe 5a
When pressurized fluid is drawn out from the pressure bag 4a and fed into the pressure bag 4b from the fluid pipe 5b, the pressure bag 4
b expands and the buried pipe 2a pushes the pressure bag 4a while compressing it.Furthermore, by performing this operation with the fluid pipe 5c and the pressure bag 4c, the buried pipes 2a to 2n move forward like earthworms. to be excavated.

As the pressure bag expands, the other pressure bags are strongly crushed between the buried pipes and become flat. That is, in FIG. 2A, for example, pressure bag 4'b is flattened and the inner surface of the bag are in close contact. However, when compressed air is sent into the pressurized bag 4'b next time, since the inside of the bag is in close contact with each other, there is no room for air to enter, and the compressed air gradually flows between the inner surfaces that are in close contact with each other against the large inflow resistance. The purpose can be achieved by infiltrating the bag, but when compressed air does not flow uniformly throughout the bag, and instead flows concentratedly into areas with low adhesion and relatively little resistance, it changes the shape of the bag and causes damage to the bag. The major drawback is that it lacks durability and propulsion is not uniform.

Therefore, the present invention provides a space retainer inside the pressurized bag that retains air permeability even when pressed under high pressure, such as a textile product such as a woven fabric, a knitted fabric, a raised (flocked) sheet, or a nonwoven fabric. To explain, in FIGS. 2B and 3, the pressurized bag 4a has a tube shape, and the inner periphery is lined with an inner lining 4' made of a rubber material with excellent airtightness.
A reinforcing material 4'' which can be compressed and expanded like a canvas and is highly durable is provided on the outer periphery of the reinforcing material 4'', and the outer periphery is further comprised of an exterior 4'' which can sufficiently withstand the pressure of the injection fluid, although this is not shown in the drawing. The portion is provided with communication holes 3a to 3c that connect with the fluid pipes 5a to 5c.However, the gist of the present invention is to provide the above-mentioned space retaining body 8 on the entire inner periphery of the interior 4'. Note that this space retaining body 8 may be provided in a spiral or linear shape instead of on the entire inner periphery, or in other words, it may be configured with an uneven inner surface so that space is retained even in a compressed state. The attachment to the interior 4' may be fixed entirely (adhesive) or partially (point adhesive), and the space retaining body 8 may be attached in the cross-sectional diameter direction of the interior 4' so that the interior 4' does not come into direct contact with the interior 4' when it is in a flat state. A fixed band-like material may be used, but in this case, the diameter changes due to compression and expansion, so a material with sufficient width or a stretchable material, such as a knitted material, is used to accommodate this change. be able to.

In this way, the present invention maintains a space even when the pressurized bag is strongly compressed, so that when compressed air is injected, it can be easily inflated uniformly without the resistance that would occur when the bag is in close contact, so that the work can be done smoothly. can proceed.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention. Figure 1 is a schematic front view of a hydraulic excavation device, Figure 2 is a cutaway front view of the main part, A is a cross-sectional view showing the compressed state, and B is the expanded state. A sectional view showing the state, Figure 3 is one of the pressurized bags of the present invention.
FIG. 3 is a cutaway partial view showing an example. Symbols 4a to 4n are pressurized bags, and 8 is a space holding body.

Claims (1)

[Scope of utility model registration request] In a hydraulic excavation device in which a large number of propulsion tubes are successively connected via pressure bags and the pressure bags are repeatedly pressurized and discharged to propel the excavation, the interior of the pressure bag interposed between the propulsion tubes. In addition, a pressurized bag for a hydraulic excavation equipment is provided with a space holding body that allows fluid to pass even under strong external pressure.