JPH0137035Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a shield excavator which has a simple structure and allows easy and reliable directional control of the shield body.

Shield tunneling machines are widely used in tunnel construction for water supply, sewage, electric power, communication cables, public ditches, etc. Especially when constructing tunnels on soft ground such as water-logged sand layers that are prone to collapse, shield tunneling machines are generally used to add muddy water. A pressure-type shield excavator is used.
This involves excavating while stabilizing the ground using the mud pressure at the face, introducing the excavated soil from the cutter slit into the mud chamber, and then discharging it from the mud chamber to the outside through the mud transport pipe. The speed of the shield body is controlled according to the amount of discharge, and as the excavation progresses, a lining consisting of multiple segments (lining segments) is assembled to prevent the tunnel from collapsing, water leakage, etc. The thrust force is obtained by a shield jack using the segment as a reaction force. That is, the end face of the segment is pressed rearward with a plurality of shield jacks arranged on the inner circumferential wall of the shield body,
The reaction force is used to move the shield body forward at a constant speed. Thus, the liner segments assembled within the shield body are exposed and left in place within the tunnel by the forward movement of the shield body. By repeating such tunnel excavation, assembly of the lining segments, and forward movement of the shield body, a predetermined lining segment is laid within the tunnel.

In this case, when excavating in a straight line, the direction of the shield body can be easily controlled without any problem, but when excavating in a continuous S-curve or the like, it is difficult to align the shield body along a predetermined curve.
Therefore, in the past, the direction of the shield body was controlled by one-sided pushing of the shield jack, or by stretching a wire rope between the segment and the inner peripheral wall of the shield body on the side to be curved. A tensioning device is installed in the middle to pull the rope to exert a braking force, and the shield jack on the outside of the curve is extended to apply rotational moment to the shield body. In this case, when deciding the number of shield jackets (total thrust),
The value is calculated to be two to several times the thrust required for the shield machine to dig (the thrust required to overcome the front earth pressure, water pressure, etc., frictional resistance between the shield machine's outer surface and the soil, etc.). . Therefore, even if only the shield jacks on the outside of the curve are used when making direction corrections, a sufficient number of shield jacks are provided to enable forward movement of the shield body. However, in all of the above-mentioned directional control methods, it is difficult to control the force, and it is particularly difficult to perform construction on curved portions with a small radius with high precision. Moreover, in the latter case, a tensioning device is required.

In addition, a method has also been adopted in which the shield body is divided into two parts, a front shield and a rear shield, and these parts are connected in a bendable manner. This moves forward by activating the shield jack on the outside of the curve to advance the front shield, and then activating the articulation jack on the outside of the curve to pull the rear shield. When the front shield moves forward, the front shield moves forward. is the reaction force body. Therefore, according to such a two-part structure foldable shield excavator, it is possible to perform curved excavation with a smaller radius of curvature than with an integrated shield excavator, and the amount of excess excavation can be reduced. This has the great advantage of not only preventing the collapse of the ground, but also reducing the amount of backfilling.

However, even with this type of folding type shield excavator, there is no problem when moving the front shield forward because the segment is used as a reaction force.
When pulling the rear shield, the front shield as a fixed body is likely to move, making it difficult to control the direction of the rear shield with high precision.

The present invention was developed in view of the above-mentioned points.The shield jack on the inside of the curve and the segment are connected by a wire rope through the eye plate, and the braking force is applied by this shield jack, and the segment is connected to the segment on the outside of the curve. We provide a shield excavator that allows easy and reliable directional control of the shield body by pressing the segments with a shield jack and obtaining rotational moment in the shield body, and enables construction of curved portions of tunnels with high precision. It is something to do.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention applied to a folding type shield excavator. In the same figure, the center-folding type shield excavator, which is designated as a whole by the reference numeral 1, has a front shield 2A, which is a cylindrical body formed in almost the same shape and open at both ends.
and a rear shield 2B, and these two shields 2A, 2B are bendably connected by an appropriate connecting rod (not shown) to form a center-folding type shield main body 2. In this case, the small diameter portion 3 provided at the front end of the rear shield 2B is slidably inserted into the inner circumferential surface of the rear end of the front shield 2A via the seal packing 4. It constitutes a connecting part.

A cutter head 6 is provided at the front opening of the front shield 2A, and a partition wall 9 is provided behind the cutter head 6 to partition the inside of the shield body 2 into a muddy water chamber 7 and an atmospheric pressure chamber 8. . The cutter head 6 is rotatably supported by the partition wall 9 and rotated at a reduced speed by a drive motor 10 to excavate a face portion 12 on the front surface of the shield. The earth and sand excavated by the cutter head 6 is led to the mud chamber 7 through a cutter slit section (not shown) provided in the cutter head 6, and is introduced into the mud chamber 7 by pressurized fluid supplied from the water pipe 14 and an agitator ( (not shown), the muddy water becomes muddy water, and this muddy water is guided to the rear of the shield body 2 by the muddy water pipe 15 and discharged to the outside of the tunnel 16.

On the other hand, a well-known ring-type gate-shaped segment erector device 18 is disposed at the center of the interior of the rear shield 2B. This segment erector device 18
is equipped with an erector ring 22 that is rotatably supported by a plurality of rollers 20 arranged concentrically inside the rear shield 2B and is rotated by a rotation motor 21. An erector arm 24 is provided to assemble the lining 23 as the tunnel 16 is excavated. The lining 23 is made of iron divided into six parts, for example.
It is constructed by joining arc-shaped backing segments 23a, 23b, 23c... made of concrete etc. in a ring shape, and each segment 23a, 23
b, 23c, . It will be done. Then, this assembled lining 23 is sequentially joined in series with connecting members such as bolts, and as the shield main body 2 moves forward using the lining 23 as a reaction force by a shield jack described later, the rear shield It is relatively sent out into the tunnel 16 from the rear end opening of 2B and left there. A tail gasket 27 is disposed around the entire circumference of the inner circumferential wall of the tail portion of the rear shield 2B, and the outer circumferential surface of the lining 23 comes into sliding contact with the inner circumferential wall of the tail portion of the rear shield 2B to prevent muddy water from entering.

A plurality of shield jacks 30 (only one is shown in the figure) are arranged at equal intervals in the circumferential direction of the shield 2B on the inner circumferential wall on the front end side of the rear shield 2B. In this case, the number of shield jacks 30 installed is set to be a sufficient number to enable forward movement of the shield body 2 even when only the shield jacks on the outside of the curve are used. The outer end of the rod 31 of each shield jack 30 is formed into a spherical shape as shown in FIG.
A spray dash 33 is attached to the. This spread dash 33 has a two-part structure to hold the spherical portion 31A under pressure, and its rear end face faces the front end face a of the lining 23. Each of the shield jacks 30 is connected to an appropriate hydraulic pressure supply source (not shown) and operates simultaneously by being supplied with pressure oil at a constant speed. is configured to move forward as a reaction force. That is, when all the shield jacks 30 are driven simultaneously to extend their rods 31 backward, each rod 3
Since one spread dash 33 simultaneously presses the front end surfaces of the opposing lining segments 23a, 23b, 23c..., each shield jack 30 receives a reaction force from the lining 23, and as a result, the shield main body 2 move forward in a straight line. The lining 23 is therefore pushed relatively rearward and left in place within the tunnel 16.

On the other hand, when the shield body 2 is moved along a predetermined curve, the wire rope 40 connects the shield jack 30 and the lining 23 on the inside of the curve. In this connection, when the shield main body 2 is to be advanced in the direction of arrow 42 in FIG. 1, for example, the eye plate 43 is removably attached to the shield jack 30 on the inside of the curve. As shown in FIG. 2, this eye plate 43 is inserted into an eye plate attachment hole 44 provided at the center of the rear end surface of the spreader shaft 33 and screwed to the spherical portion 31A of the rod 31. One end of the wire rope 40 is connected. Similarly, the inner peripheral surface of the lining 23 also has a first
As shown in the figure, another eye plate 45 is detachably connected, and the other end of the wire rope 40 is connected to this.

In this state, when the shield jack 30 on the outside of the curve is driven and the lining 23 is pushed backward by the spreader shaft 33 of the rod 31, the shield jack 30 on the outside receives a reaction force from the lining 23. , attempts to move the shield body 2 forward. At this time, the shield jack 30 on the inside of the curve simply keeps the wire rope 40 under tension and slowly stretches it to prevent it from breaking, thereby applying a brake on the forward movement of the shield body 2. As a result, the shield main body 2 receives a rotational moment in the direction of the arrow 42, so that it curves along a predetermined curve, and thus the direction of the shield main body 2 is controlled.

In this case, the direction of the shield body 2 is controlled by pushing the shield jack 30 on one side by simply using the wire rope 40 and the eye plates 43 and 45 that are detachably attached to the spread dash 33 and the lining 23. Unlike the conventional wire rope tensioning device, the structure is simple and easy to handle. In addition, during propulsion, the lining 23 serves as a reaction force and the front shield 2A and rear shield 2B move integrally, so there is no need to advance both shields 2A and 2B alternately, allowing for high-precision curved excavation. Moreover, the direction correction jack 50 (see Fig. 1)
If the front shield 2A is bent by
Curved excavation with a smaller radius is possible.

Here, in the present invention, the eye plates 43 and 45 are attached to the shield jack 30 and the lining 23 in a detachable manner, but the main reason for this is that
The eye plates 43, 45 are installed only on the inside of the curve where they are needed, the wire rope 40 connects the shield jack 30 on the inside of the curve and the lining 23, and the shield jack on the outside of the curve presses the segment. If the eye plate 43 is attached to the shield jack 30 of the shield jack 30, it will get in the way when pressing the segments, and there is no need to do so.
This is due to the two points of achieving economic efficiency by attaching and using only the necessary locations.

Although the above embodiment has been described in the case where it is applied to a folding type shield tunneling machine, the present invention is not limited to this, and can be applied to various shield tunneling machines that use a lining segment as a reaction force. Of course.

As explained above, according to the shield excavator according to the present invention, when excavating a curve, the shield jack on the inside of the curve and the backing are connected by a wire rope through the eye plate, and the shield jack on the outside of the curve connects the backing with the shield jack on the outside of the curve. Since the structure is configured to correct the direction of the shield body by pressing the tension, the structure is simple and easy to handle, and the direction of the shield body can be controlled easily and reliably, making it possible to construct tunnels with high precision. , its practical effects are very large.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention applied to a folding type shield excavator, and FIG. 2 is a sectional view of the main part of the shield jack. 1...Central folding type shield excavator, 2...Shield body, 2A...Front shield, 2B...Rear shield, 23...Lining, 23a, 23b, 23
c...Lining segment, 30...Shield jack, 31...Rod, 33...Spread dash, 40...Wire rope, 43, 45...Eye plate.

Claims (1)

[Scope of utility model registration request] A shield body, a plurality of shield jacks arranged in parallel along the circumferential direction on the inner circumferential wall of the shield body and which advance the shield body using the lining segment as a reaction force; an eye plate removably connected to the lining segment; and an eye plate selectively removably connected to the lining segment;
A shield excavator comprising: a wire rope that connects a shield jack on the inside of a curve and the lining segment via the eye plate when the shield main body moves through the curve.